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How early during pregnancy does non-invasive cffDNA testing allow sex determination of the fetus?

Using cffDNA from maternal blood, the fetal gender can be determined as early as 6 to 10 weeks of gestation (during the first trimester of pregnancy).

[12661284, 23407464, 14680784, 25343090, 23690098, 11746166, 24094458, 22261468, 22192861]

OBJECTIVE: Fetal sex prediction can be achieved using PCR targeted at the SRY gene by analyzing cell-free fetal DNA in maternal serum. Unfortunately, the results reported to date, show lack of sensitivity, especially in the first trimester of pregnancy. Therefore, determination of fetal sex by maternal serum analysis can not replace caryotype analysis following chorionic villus sampling. PATIENTS AND METHODS: A new highly sensitive real-time PCR was developed to detect a SRY gene sequence in maternal serum. Analysis was performed on 121 pregnant women during their first trimester of pregnancy (mean gestational age: 11.8 weeks). Among them, 61 had at least one previous male-bearing pregnancy. Results were compared to fetal sex. RESULTS: SRY PCR analysis of maternal serum was in complete concordance with fetal sex. Among the 121 pregnant women, 61 were bearing a male fetus and 60 a female fetus No false negative results were observed. Furthermore, no false positive results results occurred although 27 women carried female fetus during the current pregnancy, had at least one previous male-bearing pregnancy. DISCUSSION AND CONCLUSION: This study demonstrates that a reliable, non-invasive sex determination can be achieved by PCR analysis of maternal serum during the first trimester of pregnancy. This non-invasive approach for fetal sex prediction should have great implications in the management of pregnant women carriers of an X-linked genetic disorder. Prenatal diagnosis is thus performed for male fetuses only, avoiding invasive procedures and the risk of fetal loss for female fetuses. In previous years, identification of fetal cells in maternal blood circulation has caused a new revolution in non-invasive method of prenatal diagnosis. Low number of fetal cells in maternal blood and long-term survival after pregnancy limited the use of fetal cells in diagnostic and clinical applications. With the discovery of cell-free fetal DNA (cffDNA) in plasma of pregnant women, access to genetic material of the fetus had become possible to determine early gender of a fetus in pregnancies at the risk of X-linked genetic conditions instead of applying invasive methods. Therefore in this study, the probability of detecting sequences on the Y chromosome in pregnant women has been evaluated to identify the gender of fetuses. Peripheral blood samples were obtained from 80 pregnant women at 6(th) to 10(th) weeks of gestation and then the fetal DNA was extracted from the plasma. Nested PCR was applied to detect the sequences of single copy SRY gene and multi copy DYS14 & DAZ genes on the Y chromosome of the male fetuses. At the end, all the obtained results were compared with the actual gender of the newborns. In 40 out of 42 born baby boys, the relevant gene sequences were identified and 95.2% sensitivity was obtained. Non-invasive early determination of fetal gender using cffDNA could be employed as a pre-test in the shortest possible time and with a high reliability to avoid applying invasive methods in cases where a fetus is at the risk of genetic diseases. OBJECTIVE: Couples with a risk of transmitting X-linked diseases included in a preimplantation genetic diagnosis (PGD) center need early and rapid fetal sex determination during pregnancy in two situations. The first situation corresponds to control of embryo sexing after PGD, the second one being that of couples in PGD program having a spontaneous pregnancy. Determination of fetal sex can be achieved by karyotyping using invasive procedures such as chorionic villus sampling (CVS), amniocentesis or cordocentesis and by non-invasive procedures such as ultrasound (US) examination. CVS is the earliest invasive procedure for fetal sex determination and molecular analysis of X-linked genetic disorders during the first trimester but it is associated with a risk of fetal loss. US allows reliable fetal sex determination only during the second trimester. Recently, reliable non-invasive fetal sex determination was realized by using SRY gene amplification in maternal serum. PATIENTS AND METHODS: We report the prospective use of fetal sex determination in maternal serum in our PGD center. Management of pregnancies was performed using this non-invasive procedure in four cases of embryo sexing control and nine cases of spontaneous pregnancies in couples included in PGD program for X-linked diseases. RESULTS: Fetal sex results using SRY gene amplification on maternal serum were in complete concordance with fetal sex observed by cytogenetic analysis or US examination, as well as at birth. DISCUSSION AND CONCLUSION: This new strategy allowed rapid sex determination during the first trimester and permitted to avoid performing invasive procedures in nine pregnancies. Chorionic villus sampling (CVS) or amniocentesis for fetal sex determination is generally the first step in the prenatal diagnosis of X-linked genetic disorders such as Duchenne muscular dystrophy (DMD). However, non-invasive prenatal diagnostic (NIPD) techniques such as measurement of cell-free fetal DNA (cffDNA) in maternal plasma are preferable given the procedure-related miscarriage rate of CVS. We determined fetal sex during the first trimester using a quantitative real-time polymerase chain reaction (PCR) assay of cffDNA in pregnant carriers of DMD. The fetal sex was confirmed by amniocentesis karyotype analysis and multiplex ligation-dependent probe amplification (MLPA) at 16 weeks. This procedure may avoid unnecessary CVS or amniocentesis of female fetuses. Fetal sex prediction can be achieved using PCR targeted at the SRY gene by analysing cell-free fetal DNA in maternal serum. Unfortunately, the results reported to date show a lack of sensitivity, especially during the first trimester of pregnancy. Therefore, determination of fetal sex by maternal serum analysis could not replace karyotype analysis following chorionic villus sampling. A new highly sensitive real-time PCR was developed to detect an SRY gene sequence in maternal serum. Analysis was performed on 121 pregnant women during the first trimester of pregnancy (mean gestational age: 11.8 weeks). Among them, 51 had at least one previous male-bearing pregnancy. Results were compared with fetal sex. SRY PCR analysis of maternal serum was in complete concordance with fetal sex. Among the 121 pregnant women, 61 were bearing a male fetus and 60 a female fetus. No false-negative results were observed. Furthermore, no false-positive results occurred, even though 27 women carrying a female fetus during the current pregnancy had at least one previous male-bearing pregnancy. This study demonstrates that a reliable, non-invasive sex determination can be achieved by PCR analysis of maternal serum during the first trimester of pregnancy. This non-invasive approach for fetal sex prediction should have great implications in the management of pregnant women who are carriers of an X-linked genetic disorder. Prenatal diagnosis might thus be performed for male fetuses only, avoiding invasive procedures and the risk of the loss of female fetuses. BACKGROUND: Detection of cell-free fetal DNA (cffDNA) in maternal plasma has given rise to the possibility of new non-invasive approaches for early prenatal diagnoses. We evaluated the feasibility and accuracy of non-invasive fetal gender determination using quantitative fluorescent-polymerase chain reaction (QF-PCR) analysis of circulating cffDNA in the first-trimester maternal plasma. METHODS: Plasma samples were prospectively collected from 202 singleton pregnancies at 4 to 13 weeks of gestation. Fetal gender was determined by QF-PCR with the sex-determining region Y (SRY) and amelogenin X/Y (AMELX/Y) genes. The result was confirmed by fetal karyotyping or phenotype at birth. RESULTS: Of the 202 pregnancies, 162 had pregnancy outcomes available and could be included in our evaluation. The accuracies of AMELX/Y, SRY, and combined AMELX/Y+SRY analysis for fetal gender determination were 83.3%, 82.1%, and 97.5%, respectively, compared with those of the invasive approach and the fetal gender outcome at birth (82 males and 80 females). Combined AMELX/Y+SRY analysis had the highest sensitivity (98.8%) for fetal gender determination with a specificity of 96.3%. Moreover, fetal gender detection by the combined AMELX/Y+SRY analysis at 11 to 13 weeks of gestation was 100% correct. CONCLUSION: Fetal gender determination could be accurately determined from maternal cffDNA in the first-trimester using QF-PCR analysis of combined AMELX/Y+SRY.

Does cortical spreading depression appear in ischemic penumbra following ischemic stroke?

Yes, cortical spreading depression appears in ischemic penumbra following ischemic stroke and is associated with expansion of ischemic injury. This has been shown in humans and in animal models.

[10082816, 22821441, 11450018, 7944288, 20700132, 15703392, 9740103, 14759495, 15879337, 22994218, 20087371, 14568331, 20660268, 15078545, 8623122, 18446167]

Spreading depolarizations are a key event in the pathophysiology of stroke, resulting in rapid dendritic beading, which represents acute damage to synaptic circuitry. The impact of spreading depolarizations on the real-time injury of astrocytes during ischemia is less clear. We used simultaneous in vivo 2-photon imaging and electrophysiological recordings in adult mouse somatosensory cortex to examine spreading depolarization-induced astroglial structural changes concurrently with signs of neuronal injury in the early periods of focal and global ischemia. Astrocytes in the metabolically compromised ischemic penumbra-like area showed a long lasting swelling response to spontaneous spreading depolarizations despite rapid dendritic recovery in a photothrombotic occlusion model of focal stroke. Astroglial swelling was often facilitated by recurrent depolarizations and the magnitude of swelling strongly correlated with the total duration of depolarization. In contrast, spreading depolarization-induced astroglial swelling was transient in normoxic healthy tissue. In a model of transient global ischemia, the occurrence of a single spreading depolarization elicited by a bilateral common carotid artery occlusion coincided with astroglial swelling alongside dendritic beading. With immediate reperfusion, dendritic beading subsides. Astroglial swelling was either transient during short ischemic periods distinguished by a short-lasting spreading depolarization, or persistent during severe ischemia characterized by a long-lasting depolarization with the ultraslow negative voltage component. We propose that persistent astroglial swelling is initiated and exacerbated during spreading depolarization in brain tissue with moderate to severe energy deficits, disrupting astroglial maintenance of normal homeostatic function thus contributing to the negative outcome of ischemic stroke as astrocytes fail to provide neuronal support. BACKGROUND: Spreading depression (SD) is known to go along with temporary breakdown of ion gradients and cell swelling which spontaneously normalizes. Here, the effects of SD at reduced flow conditions as encountered in the ischemic penumbra are examined. METHODS: In rats the right carotid artery was permanently occluded. MABP was lowered to 50 mmHg for 30 min. This is sufficient to reduce CBF to penumbra-like conditions in the right hemisphere. The following parameters were assessed: rCBF, DC potential, and tissue impedance. 5 or 15 min after onset of flow reduction one SD wave was initiated by microinjection of KCl. Histology was performed after 7 days. RESULTS: In animals with hypotension there was depolarization resembling anoxic depolarization after SD induction and an uncoupling of CBF and metabolism only in the right hemisphere. Impedance increased with SD but did not recover spontaneously as long as rCBF remained reduced. 15 min of SD-induced cell swelling was tolerated without permanent damage, whereas 25 min were followed by severe neuron loss in the affected cortex after 7 days. CONCLUSIONS: The study demonstrates the induction of penumbra conditions in the cortex of one hemisphere. SD is followed by cell swelling which persists as long as flow is critically reduced. The experiments illustrate how peri-infarct depolarizations may detrimentally affect the penumbra. The classic concept of the viability thresholds of ischemia differentiates between two critical flow rates, the threshold of electrical failure and the threshold of membrane failure. These thresholds mark the upper and lower flow limits of the ischemic penumbra which is thought to suffer only functional but not structural injury. Recent studies of the functional and metabolic disturbances suggest a more complex pattern of thresholds. At declining flow rates, protein synthesis is inhibited at first (at a threshold of about 0.55 ml/gm/min), followed by a stimulation of anaerobic glycolysis (at 0.35 ml/gm/min), the release of neurotransmitters and the beginning disturbance of energy metabolism (at about 0.20 ml/min), and finally the anoxic depolarization (< 0.15 ml/gm/min). The penumbra, as defined by the classic flow thresholds, does not remain viable for extended periods. Since viability of the tissue requires maintenance of energy-dependent metabolic processes, penumbra is redefined as a region of constrained blood supply in which the energy metabolism is preserved. Imaging of the penumbra by combining autoradiographic cerebral blood flow measurements with bioluminescent images of adenosine triphosphate (ATP) demonstrates a gradual expansion of the infarct core (in which ATP is depleted) into the penumbra until, after a few hours, the penumbra has disappeared. It is suggested that the limited survival of the penumbra is due to periinfarct depolarizations, which result in repeated episodes of tissue hypoxia, because the increased metabolic workload is not coupled to an adequate increase of collateral blood supply. This explains pharmacological suppression of periinfarct depolarizations lowering the threshold of metabolic disturbances and reducing the volume of the ischemic infarct. When a cerebral infarction occurs, surrounding the core of dying tissue there usually is an ischemic penumbra of nonfunctional but still viable tissue. One current but controversial hypothesis is that this penumbra tissue often eventually dies because of the metabolic stress imposed by multiple cortical spreading depression (CSD) waves, that is, by ischemic depolarizations. We describe here a computational model of CSD developed to study the implications of this hypothesis. After simulated infarction, the model displays the linear relation between final infarct size and the number of CSD waves traversing the penumbra that has been reported experimentally, although damage with each individual wave progresses nonlinearly with time. It successfully reproduces the experimental dependency of final infarct size on midpenumbra cerebral blood flow and potassium reuptake rates, and predicts a critical penumbra blood flow rate beyond which damage does not occur. The model reproduces the dependency of CSD wave propagation on N-methyl-D-aspartate activation. It also makes testable predictions about the number, velocity, and duration of ischemic CSD waves and predicts a positive correlation between the duration of elevated potassium in the infarct core and the number of CSD waves. These findings support the hypothesis that CSD waves play an important causal role in the death of ischemic penumbra tissue. Spreading depression (SD) has been demonstrated following focal ischemia, and the additional workload imposed by SD on a tissue already compromised by a marked reduction in blood flow may contribute to the evolution of irreversible damage in the ischemic penumbra. SD was elicited in one group of rats by injecting KCl directly into a frontal craniectomy and the wave of depolarization was recorded in two craniectomies 3 and 6 mm posterior to the first one. In a second group, the middle cerebral artery was occluded using the monofilament technique and a recording electrode was placed 5 mm lateral to the midline and 0.2 mm posterior to bregma. To determine the metabolic response in the penumbral region of the cortex ipsilateral to the occlusion, brains from both groups were frozen in situ when the deflection of the SD was maximal. The spatial metabolic response of SD in the ischemic cortex was compared to that in the non-ischemic cortex. Coronal sections of the brains were lyophilized, pieces of the dorsolateral cortex were dissected and weighed, and analyzed for ATP, P-creatine, inorganic phosphate (Pi), glucose, glycogen and lactate at varying distances anterior and posterior to the recording electrode. ATP and P-creatine levels were significantly decreased at the wavefront in both groups and the levels recovered after passage of the wavefront in the normal brain, but not in the ischemic brain. Glucose and glycogen levels were significantly decreased and lactate levels significantly increased in the tissue after the passage of the wavefront. While the changes in the glucose-related metabolites persisted during recovery even in anterior portions of the cortex in both groups in the aftermath of the SD, the magnitude of the changes was greater in the penumbra than in the normal cortex. SD appears to impose an equivalent increase in energy demands in control and ischemic brain, but the ability of the penumbra to recover from the insult is compromised. Thus, increasing the energy imbalance in the penumbra after multiple SDs may hasten the deterioration of the energy status of the tissue and eventually contribute to terminal depolarization and cell death, particularly in the penumbra. BACKGROUND AND PURPOSE: Spreading depression (SD)-like depolarizations may augment neuronal damage in neurovascular disorders such as stroke and traumatic brain injury. Spreading ischemia (SI), a particularly malignant variant of SD-like depolarization, is characterized by inverse coupling between the spreading depolarization wave and cerebral blood flow. SI has been implicated in particular in the pathophysiology of subarachnoid hemorrhage. Under physiological conditions, SD is blocked by N-methyl-D-aspartate receptor (NMDAR) antagonists. However, because both SD-like depolarizations and SI occur in presence of an increased extracellular K+ concentration ([K+]o), we tested whether this increase in baseline [K+]o would reduce the efficacy of NMDAR antagonists. METHODS: Cranial window preparations, laser Doppler flowmetry, and K+-sensitive/reference microelectrodes were used to record SD, SD-like depolarizations, and SI in rats in vivo; microelectrodes and intrinsic optical signal measurements were used to record SD and SD-like depolarizations in human and rat brain slices. RESULTS: In vivo, the noncompetitive NMDAR antagonist dizocilpine (MK-801) blocked SD propagation under physiological conditions, but did not block SD-like depolarizations or SI under high baseline [K+]o. Similar results were found in human and rat neocortical slices with both MK-801 and the competitive NMDAR antagonist D-2-amino-5-phosphonovaleric acid. CONCLUSIONS: Our data suggest that elevated baseline [K+]o reduces the efficacy of NMDAR antagonists on SD-like depolarizations and SI. In conditions of moderate energy depletion, as in the ischemic penumbra, or after subarachnoid hemorrhage, NMDAR inhibition may not be sufficient to block these depolarizations. An ischemic penumbra has the potential for functional recovery provided that local blood flow can be reestablished, but irreversible damage will develop without sufficient reperfusion, depending on the interaction of severity and duration of ischemia. With acute flows below the threshold required for maintenance of basic housekeeping, injury in the core is established within a few minutes. During the subacute phase, the irreversible damage expands into the penumbra: multiple electrical and biological signals are triggered by periinfarct, spreading depression-like depolarizations leading to hypoxia and stepwise increase in lactate. Usually within 6 to 8 hours, all the penumbra are converted into irreversible infarcts. In a delayed phase, secondary phenomena may cause additional tissue damage: disruption of the tight junctions results in vasogenic edema, leading to increase of water content and damage expansion. Neutrophils and cytokinins cause secondary inflammation, inducing further damage in periinfarct regions and connecting fiber tracts. Multimodal imaging might be able to differentiate among the tissue compartments affected by acute, subacute, or delayed ischemic damage, and thereby might provide the basis for phase-specific treatment strategies. Spreading depression (SD) is a slowly propagating wave of transient neuronal and glial depolarization that develops after stroke, trauma and subarachnoid hemorrhage. In compromised tissue, repetitive SD-like injury depolarizations reduce tissue viability by worsening the mismatch between blood flow and metabolism. Although the mechanism remains unknown, SDs show delayed electrophysiological recovery within the ischemic penumbra. Here, we tested the hypothesis that the recovery rate of SD can be varied by modulating tissue perfusion pressure and oxygenation. Systemic blood pressure and arterial pO(2) were simultaneously manipulated in anesthetized rats under full physiologic monitoring. We found that arterial hypotension doubled the SD duration, whereas hypertension reduced it by a third compared with normoxic normotensive rats. Hyperoxia failed to shorten the prolonged SD durations in hypotensive rats, despite restoring tissue pO(2). Indeed, varying arterial pO(2) (40 to 400 mm Hg) alone did not significantly influence SD duration, whereas blood pressure (40 to 160 mm Hg) was inversely related to SD duration in compromised tissue. These data suggest that cerebral perfusion pressure is a critical determinant of SD duration independent of tissue oxygenation over a wide range of arterial pO(2) levels, and that hypotension may be detrimental in stroke and subarachnoid hemorrhage, where SD-like injury depolarizations have been observed. The effect of the free radical spin-trap alpha-phenyl-butyl-tert-nitrone (alpha-PBN) in permanent focal cerebral ischemia in rats was examined in two series of experiments. In the first, rats were subjected to permanent occlusion of the middle cerebral artery (MCAO) and treated 1 h after occlusion with a single dose of alpha-PBN (100 mg/kg) or saline. Body temperature was measured and controlled for the first 24 h to obtain identical temperature curves in the two groups. Cortical infarct volumes were determined on histological sections 7 days later. alpha-PBN did not significantly reduce infarct volume (control: 28.3+/-16.3 mm3 vs. alpha-PBN 23.7+/-7.4 mm3). In the second series of experiments, periinfarct depolarizations (PIDs) were recorded with an extracellular DC electrode at two locations in the ischemic penumbra for the initial 3 h following MCAO. alpha-PBN (100 mg/kg, single dose in conjunction with occlusion) significantly reduced the total number (median value of 3 PIDs in the control groups vs. 1 PID in alpha-PBN groups, p<0.001) and total duration of the PIDs (median value 662 s in the control groups vs. 162 s in the alpha-PBN groups, p<0.006). In spite of this, cortical infarct volumes determined 7 days later in the same rats were not smaller in alpha-PBN-treated rats. The study thus demonstrates that attenuation of PIDs does not always lead to smaller infarcts if permanent arterial occlusion is followed by long survival time and does not support the hypothesis that PIDs per se are critical determinants of infarct size in this situation. Spontaneous spreading depolarizations (SDs) occur in the penumbra surrounding ischemic core. These SDs, often referred to as peri-infarct depolarizations, cause vasoconstriction and recruitment of the penumbra into the ischemic core in the critical first hours after focal ischemic stroke; however, the real-time spatiotemporal dynamics of SD-induced injury to synaptic circuitry in the penumbra remain unknown. A modified cortical photothrombosis model was used to produce a square-shaped lesion surrounding a penumbra-like "area at risk" in middle cerebral artery territory of mouse somatosensory cortex. Lesioning resulted in recurrent spontaneous SDs. In vivo two-photon microscopy of green fluorescent protein-expressing neurons in this penumbra-like area at risk revealed that SDs were temporally correlated with rapid (<6 s) dendritic beading. Dendrites quickly (<3 min) recovered between SDs to near-control morphology until the occurrence of SD-induced terminal dendritic injury, signifying acute synaptic damage. SDs are characterized by a breakdown of ion homeostasis that can be recovered by ion pumps if the energy supply is adequate. Indeed, the likelihood of rapid dendritic recovery between SDs was correlated with the presence of nearby flowing blood vessels, but the presence of such vessels was not always sufficient for rapid dendritic recovery, suggesting that energy needs for recovery exceeded energy supply of compromised blood flow. We propose that metabolic stress resulting from recurring SDs facilitates acute injury at the level of dendrites and dendritic spines in metabolically compromised tissue, expediting penumbral recruitment into the ischemic core. Focal brain infarcts are surrounded by extended perilesional zones that comprise the partially ischemic penumbra but also completely non-ischemic cortex of the remote ipsilateral hemisphere. To delineate the impact of lesion-associated vs. remote processes on transcriptional programming after focal ischemia, we used cDNA array analysis, quantitative real-time polymerase chain reaction and immunohistochemistry in the photothrombosis model of circumscribed cortical ischemia in rats. At an early stage of 4 h after ischemia, gene induction occurred to a similar extent in the ischemic infarct and remote non-ischemic cortex of the ipsilateral hemisphere. Among the genes induced in non-ischemic cortex we found the NGF-inducible genes PC3, VGF and Arc, the transcriptional regulators I kappa B-alpha and Stat3, and the beta-chemokine MIP-1 alpha (CCL3). At 3 days, the spatial pattern of gene expression had changed dramatically with brain fatty acid-binding protein as the only gene significantly induced in non-ischemic ipsilateral cortex. In contrast, numerous genes were exclusively regulated at the lesion site, comprising genes involved in cell cycle regulation, proteolysis, apoptosis, lipid homeostasis and anti-inflammatory counter-regulation. Cortical spreading depression was identified as the main mechanism underlying gene induction in remote non-ischemic cortex. Our data demonstrate a dynamic spatiotemporal pattern of gene induction, which may contribute to delayed progression of damage or, alternatively, mediate neuroprotection, tissue remodeling and functional compensation.

Is phospholamban a regulatory/inhibitory protein of the Ca ATPase SERCA?

Phospholamban (PLB) is a 24- to 27-kDa phosphoprotein that modulates activity of the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA). Expression of PLB is reportedly limited to cardiac, slow-twitch skeletal and smooth muscle in which PLB is an important regulator of [Ca2+]i and contractility in these muscles.The membrane protein complex between the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) and phospholamban (PLN) controls Ca(2+) transport in cardiomyocytes, thereby modulating cardiac contractility. β-Adrenergic-stimulated phosphorylation of PLN at Ser-16 enhances SERCA activity via an unknown mechanism.

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Phospholamban (PLB) inhibits the sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA), and this inhibition is relieved by Ca(2+) calmodulin-dependent protein kinase II (CaM kinase II) phosphorylation. We previously reported significant differences in contractility, SR Ca(2+) release, and CaM kinase II activity in gastric fundus smooth muscles as a result of PLB phosphorylation by CaM kinase II. In this study, we used PLB-knockout (PLB-KO) mice to directly examine the effect of PLB absence on contractility, CaM kinase II activity, and intracellular Ca(2+) waves in gastric antrum smooth muscles. The frequencies and amplitudes of spontaneous phasic contractions were elevated in antrum smooth muscle strips from PLB-KO mice. Bethanecol increased the amplitudes of phasic contractions in antrum smooth muscles from both control and PLB-KO mice. Caffeine decreased and cyclopiazonic acid (CPA) increased the basal tone of antrum smooth muscle strips from PLB-KO mice, but the effects were less pronounced compared with control strips. The CaM kinase II inhibitor KN-93 was less effective at inhibiting caffeine-induced relaxation in antrum smooth muscle strips from PLB-KO mice. CaM kinase II autonomous activity was elevated, and not further increased by caffeine, in antrum smooth muscles from PLB-KO mice. Similarly, the intracellular Ca(2+) wave frequency was elevated, and not further increased by caffeine, in antrum smooth muscles from PLB-KO mice. These findings suggest that PLB is an important modulator of gastric antrum smooth muscle contractility by modulation of SR Ca(2+) release and CaM kinase II activity. Phospholamban (PLB) is an integral membrane protein regulating Ca(2+) transport through inhibitory interaction with sarco(endo)plasmic reticulum calcium ATPase (SERCA). The Asn27 to Ala (N27A) mutation of PLB has been shown to function as a superinhibitor of the affinity of SERCA for Ca(2+) and of cardiac contractility in vivo. The effects of this N27A mutation on the side-chain and backbone dynamics of PLB were investigated with (2)H and (15)N solid-state NMR spectroscopy in phospholipid multilamellar vesicles (MLVs). (2)H and (15)N NMR spectra indicate that the N27A mutation does not significantly change the side-chain or backbone dynamics of the transmembrane and cytoplasmic domains when compared to wild-type PLB. However, dynamic changes are observed for the hinge region, in which greater mobility is observed for the CD(3)-labeled Ala24 N27A-PLB. The increased dynamics in the hinge region of PLB upon N27A mutation may allow the cytoplasmic helix to more easily interact with the Ca(2+)-ATPase; thus, showing increased inhibition of Ca(2+)-ATPase. 1. Phospholamban (PLB) is an inhibitor of the sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA). Its presence and/or functional significance in contractility of bladder, a smooth muscle tissue particularly dependent on SR function, is unknown. We investigated this by measuring the effects of carbachol (CCh) on force and [Ca2+]i in bladder from mice in which the PLB gene was ablated (PLB-KO mice). In the PLB-KO bladder, the maximum increases in [Ca2+]i and force were significantly decreased (41.5 and 47.4 % of WT), and the EC50 values increased. 2. Inhibition of SERCA with cyclopiazonic acid (CPA) abolished these differences between WT and PLB-KO bladder, localizing the effects to the SR. 3. To determine whether these effects were specific to PLB, we generated mice with smooth-muscle-specific expression of PLB (PLB-SMOE mice), using the SMP8 alpha-actin promoter. Western blot analysis of PLB-SMOE mice showed approximately an eightfold overexpression of PLB while SERCA was downregulated 12-fold. 4. In PLB-SMOE bladders, in contrast, the response of [Ca2+]i and force to CCh was significantly increased and the EC50 values were decreased. CPA had little affect on the CCh-induced increases in [Ca2+]i and force in PLB-SMOE bladder. 5. These results show that alteration of the PLB:SERCA ratio can significantly modulate smooth muscle [Ca2+]i. Importantly, our data show that PLB can play a major role in modulation of bladder contractility. Phospholamban (PLN) is a type II membrane protein that inhibits the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA), thereby regulating calcium homeostasis in cardiac muscle. In membranes, PLN forms pentamers that have been proposed to function either as a storage for active monomers or as ion channels. Here, we report the T-state structure of pentameric PLN solved by a hybrid solution and solid-state NMR method. In lipid bilayers, PLN adopts a pinwheel topology with a narrow hydrophobic pore, which excludes ion transport. In the T state, the cytoplasmic amphipathic helices (domains Ia) are absorbed into the lipid bilayer with the transmembrane domains arranged in a left-handed coiled-coil configuration, crossing the bilayer with a tilt angle of approximately 11° with respect to the membrane normal. The tilt angle difference between the monomer and pentamer is approximately 13°, showing that intramembrane helix-helix association forces dominate over the hydrophobic mismatch, driving the overall topology of the transmembrane assembly. Our data reveal that both topology and function of PLN are shaped by the interactions with lipids, which fine-tune the regulation of SERCA. Calcium transport across the membrane of the sarcoplasmic reticulum (SR) plays an important role in the regulation of heart muscle contraction and relaxation. The sarco(endo)plasmic reticulum Ca(2+) ATPase (SERCA) 2a is responsible for Ca(2+) up-take by this organelle and is inhibited in a reversible manner by phospholamban, another SR membrane protein. Thus, alleviation of phospholamban-mediated inhibition of SERCA2a is a potential therapeutic option for heart failure and cardiomyopathy. We have now applied the systematic evolution of ligands by exponential enrichment protocol to a library of single-stranded DNA molecules containing a randomized 40-nucleotide sequence to isolate aptamers that bind phospholamban. One of the obtained aptamers, designated Apt-9, was found to specifically bind to the cytoplasmic region of phospholamban in vitro with high affinity (dissociation constant, approximately 20 nM). Apt-9 increased the Ca(2+)-dependent ATPase activity of cardiac SR vesicles but not that of SR vesicles from skeletal muscle in a concentration-dependent manner. It also shifted the Ca(2+) concentration-response curve for this ATPase activity to the left. These effects of Apt-9 were not mimicked by an oligonucleotide with a scrambled version of the Apt-9 sequence. Thus, our results indicate that Apt-9 activates SERCA2a by alleviating the inhibitory effect of phospholamban on this ATPase, and they suggest that phospholamban-specific aptamers warrant further investigation as potential therapeutic agents for heart failure and cardiomyopathy. Regulation of the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA 2a) depends on the phosphorylation state of phospholamban (PLB). When PLB is phosphorylated, its inhibitory effect towards SERCA 2a is relieved, leading to an enhanced myocardial performance. This process is reversed by a sarcoplasmic reticulum (SR)-associated type 1 protein phosphatase (PP1) composed of a catalytic subunit PP1C and a regulatory subunit GM. Human GM and PLB have been produced in an in vitro transcription/translation system and used for co-immunoprecipitation and biosensor experiments. The detected interaction between the two partners suggests that cardiac PPI is targeted to PLB via GM and we believe that this process occurs with the identified transmembrane domains of the two proteins. Thus, the interaction between PLB and GM may represent a specific way to modulate the SR function in human cardiac muscle. Transient elevations of intracellular Ca2+ play a signalling role in such complex cellular functions as contraction, secretion, fertilization, proliferation, metabolism, heartbeat and memory. However, prolonged elevation of Ca2+ above about 10 microM is deleterious to a cell and can activate apoptosis. In muscle, there is a narrow window of Ca2+ dysregulation in which abnormalities in Ca2+ regulatory proteins can lead to disease, rather than apoptosis. Key proteins in the regulation of muscle Ca2+ are the voltage-dependent, dihydropyridine-sensitive, L-type Ca2+ channels located in the transverse tubule and Ca2+ release channels in the junctional terminal cisternae of the sarcoplasmic reticulum. Abnormalities in these proteins play a key role in malignant hyperthermia (MH), a toxic response to anesthetics, and in central core disease (CCD), a muscle myopathy. Sarco(endo)plasmic reticulum Ca2+ ATPases (SERCAs) return sarcoplasmic Ca2+ to the lumen of the sarcoplasmic reticulum. Loss of SERCA1a Ca2+ pump function is one cause of exercise-induced impairment of the relaxation of skeletal muscle, in Brody disease. Phospholamban expressed in cardiac muscle and sarcolipin expressed in skeletal muscle regulate SERCA activity. Studies with knockout and transgenic mice show that gain of inhibitory function of phospholamban alters cardiac contractility and could be a causal feature in some cardiomyopathies. Calsequestrin, calreticulin, and a series of other acidic, lumenal, Ca2+ binding proteins provide a buffer for Ca2+ stored in the sarcoplasmic reticulum. Overexpression of cardiac calsequestrin leads to cardiomyopathy and ablation of calreticulin alters cardiac development. Phospholamban (PLN) is the endogenous inhibitor of the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA), the integral membrane enzyme responsible for 70 % of the removal of Ca(2+) from the cytosol, inducing cardiac muscle relaxation in humans. Dysfunctions in SERCA:PLN interactions have been implicated as having a critical role in cardiac disease, and targeting Ca(2+) transport has been demonstrated to be a promising avenue in treating conditions of heart failure. Here, we designed a series of new mutants able to tune SERCA function, targeting the loop sequence that connects the transmembrane and cytoplasmic helices of PLN. We found that a variable degree of loss of inhibition mutants is attainable by engineering glycine mutations along PLN's loop domain. Remarkably, a double glycine mutation results in a complete loss-of-function mutant, fully mimicking the phosphorylated state of PLN. Using nuclear magnetic resonance spectroscopy, we rationalized the effects of these mutations in terms of entropic control on PLN function, whose inhibitory function can be modulated by increasing its conformational dynamics. However, if PLN mutations go past a threshold set by the phosphorylated state, they break the structural coupling between the transmembrane and cytoplasmic domains, resulting in a species that behaves as the inhibitory transmembrane domain alone. These studies provide new potential candidates for gene therapy to reverse the effects of heart failure. Regulation of the SERCA calcium pump by phospholamban (PLB) is largely due to interactions between their respective transmembrane domains. In spite of numerous mutagenesis and kinetic studies, we still do not have a clear mechanistic picture of how PLB influences the calcium transport cycle of SERCA. Herein, we have created alanine mutants for each residue in the transmembrane domain of PLB, we have co-reconstituted these mutants with SERCA into proteoliposomes, and we have performed kinetic simulations of the calcium-dependent ATPase activity isotherms. The PLB transmembrane mutants had a variable effect on the calcium affinity, maximal activity, and cooperativity of SERCA, such that a range of values was observed. Kinetic simulations using a well-established reaction scheme for SERCA then allowed us to correlate the effects on SERCA activity with changes in the reaction scheme rate constants. Only three steps in the reaction scheme were affected by the presence of PLB, namely, binding of the first calcium ion, a subsequent conformational change in SERCA, and binding of the second calcium ion. The ability of wild-type and mutant forms of PLB to alter the apparent calcium affinity of SERCA correlated with a decreased rate of binding of the second calcium ion. In addition, the ability of wild-type and mutant forms of PLB to alter the maximal activity of SERCA correlated with a change in the forward rate constant for the slow conformational change in SERCA following binding of the first calcium ion. Phosphorylation by protein kinase A and dephosphorylation by protein phosphatase 1 modulate the inhibitory activity of phospholamban (PLN), the endogenous regulator of the sarco(endo)plasmic reticulum calcium Ca(2+) ATPase (SERCA). This cyclic mechanism constitutes the driving force for calcium reuptake from the cytoplasm into the myocite lumen, regulating cardiac contractility. PLN undergoes a conformational transition between a relaxed (R) and tense (T) state, an equilibrium perturbed by the addition of SERCA. Here, we show that the single phosphoryl transfer at Ser16 induces a more pronounced conformational switch to the R state in phosphorylated PLN (pPLN). The binding affinity of PLN to SERCA is not affected (K(d) values for the transmembrane domains of pPLN and PLN are approximately 60 microM), supporting the hypothesis that phosphorylation at Ser16 does not dissociate PLN from SERCA. However, the binding surface and dynamics in domain Ib (residues 22-31) change substantially upon phosphorylation. Since PLN can be singly or doubly phosphorylated at Ser16 and Thr17, we propose that these sites remotely control the conformation of domain Ib. These findings constitute a paradigm for how post-translational modifications such as phosphorylation in the cytoplasmic portion of membrane proteins control intramembrane protein-protein interactions. We used EPR spectroscopy to probe directly the interaction between phospholamban (PLB) and its regulatory target, the sarcoplasmic reticulum Ca-ATPase (SERCA). Synthetic monomeric PLB was prepared with a single cytoplasmic cysteine at residue 11, which was then spin labeled. PLB was reconstituted into membranes in the presence or absence of SERCA, and spin label mobility and accessibility were measured. The spin label was quite rotationally mobile in the absence of SERCA, but became more restricted in the presence of SERCA. SERCA also decreased the dependence of spin label mobility on PLB concentration in the membrane, indicating that SERCA reduces PLB-PLB interactions. The spin label MTSSL, attached to Cys11 on PLB by a disulfide bond, was stable at position 11 in the absence of SERCA. In the presence of SERCA, the spin label was released and a covalent bond was formed between PLB and SERCA, indicating direct interaction of one or more SERCA cysteine residues with Cys11 on PLB. The accessibility of the PLB-bound spin label IPSL to paramagnetic agents, localized in different phases of the membrane, indicates that SERCA greatly reduces the level of interaction of the spin label with the membrane surface. We propose that the cytoplasmic domain of PLB associates with the lipid surface, and that association with SERCA induces a major conformational change in PLB in which the cytoplasmic domain is drawn away from the lipid surface by SERCA. Vascular endothelial cells regulate vascular smooth muscle tone through Ca2+-dependent production and release of vasoactive molecules. Phospholamban (PLB) is a 24- to 27-kDa phosphoprotein that modulates activity of the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA). Expression of PLB is reportedly limited to cardiac, slow-twitch skeletal and smooth muscle in which PLB is an important regulator of [Ca2+]i and contractility in these muscles. In the present study, we report the existence of PLB in the vascular endothelium, a nonmuscle tissue, and provide functional data on PLB regulation of vascular contractility through its actions in the endothelium. Endothelium-dependent relaxation to acetylcholine was attenuated in aorta of PLB-deficient (PLB-KO) mice compared with wild-type (WT) controls. This effect was not due to actions of nitric oxide on the smooth muscle, because sodium nitroprusside-mediated relaxation in either denuded or endothelium-intact aortas was unaffected by PLB ablation. Relative to denuded vessels, relaxation to forskolin was enhanced in WT endothelium-intact aortas. The endothelium-dependent component of this relaxation was attenuated in PLB-KO aortas. To investigate whether these changes were due to PLB, WT mouse aorta endothelial cells were isolated. Both reverse transcriptase-polymerase chain reaction and Western blot analyses revealed the presence of PLB in endothelial cells, which were shown to be >98% pure by diI-acetylated LDL uptake and nuclear counterstaining. These data indicate that PLB is present and modulates vascular function as a result of its actions in endothelial cells. The presence of PLB in endothelial cells opens new fields for investigation of Ca2+ regulatory pathways in nonmuscle cells and for modulation of endothelial-vascular interactions.

Is Alpers disease inherited in an autosomal recessive mode?

Alpers disease is a fatal neurogenetic disorder first described more than 70 years ago. It is an autosomal recessive, developmental mitochondrial DNA depletion disorder characterized by deficiency in mitochondrial DNA polymerase gamma (POLG) catalytic activity, refractory seizures, neurodegeneration, and liver disease.

[21451360, 7897414, 22006280, 22000311, 16181814, 15122711, 1861211]

Alpers disease is a recessive mitochondrial disorder caused by mutations in POLG1 and characterized primarily by progressive neurological and hepatic degeneration. Intestinal dysmotility is a frequent symptom, but it is often overshadowed by other clinical manifestations. The onset and progression of Alpers disease vary; however, most patients die during childhood, often before a specific diagnosis has been established. The gastrointestinal neuromuscular pathology of 4 patients, obtained largely from postmortem specimens, showed distinctive eosinophilic cytoplasmic granules in a subset of enteric ganglia and patchy atrophy of small intestinal muscularis externa. The cytoplasmic inclusions corresponded to abnormal mitochondria, which have been reported previously in another mitochondrial disorder (mitochondrial neurogastrointestinal encephalomyopathy) but not in Alpers disease. Recognition of these distinctive light microscopic findings, in an appropriate clinical setting, should prompt the evaluation of an underlying primary mitochondriopathy. Two unrelated and previously healthy girls, aged 17 and 18, presented with a subacute encephalopathy, visual and sensory symptoms and signs, and prominent seizures that were difficult to control. Brain MRI showed lesions (high signal on T2 weighted images) in the occipital lobes and thalamus; EEG showed slow wave activity with superimposed polyspikes. Inexorable downhill progression led to death in hepatic failure within eight months of onset. Histopathological findings in both patients ((a) chronic hepatitis with prominent bile duct proliferation, fatty change, and fibrosis; (b) in the brain a patchy destruction of the cerebral cortex, predominantly involving striate cortex) were characteristic of progressive neuronal degeneration of childhood with liver disease--Alpers-Huttenlocher syndrome--a rare autosomal recessive disorder usually seen in infants and young children. Alpers syndrome is an autosomal recessive mitochondrial DNA depletion disorder that affects children and young adults. It is characterized by a progressive, fatal brain and liver disease. This syndrome has been associated with mutations in POLG, the gene encoding the mitochondrial DNA polymerase (pol gamma). Most patients with Alpers syndrome have been found to be compound heterozygotes, carrying two pathogenic mutations in trans at the POLG locus. POLG is a nuclear-encoded gene whose protein product is imported into mitochondria, where it is essential for mtDNA replication and repair. We studied the skin fibroblasts of a patient with Alpers syndrome having the genotype E873stop/A467T. The E873stop mutation produces a premature termination codon (TAG) in exon 17. The A467T mutation produces a threonine to alanine substitution at a highly conserved site in exon 7. The allele bearing the stop codon (E873-TAG) is predicted to produce a truncated, catalytically inactive polymerase. However, only full-length pol gamma protein was detected by Western blot analysis. Here, we show that transcripts containing this stop codon undergo nonsense-associated alternative splicing and nonsense-mediated decay. More than 95% of the functional POLG mRNA was derived from the allele bearing the A467T mutation and less than 5% contained the E873stop mutation. These events ensured that virtually all POLG protein in the cell was expressed from the A467T allele. Therefore, the Alpers phenotype in this patient was a consequence of a single-copy gene dose of the A467T allele, and selective elimination of transcripts bearing the E873stop mutation. Alpers' syndrome is a fatal neurogenetic disorder first described more than 70 years ago. It is an autosomal recessive, developmental mitochondrial DNA depletion disorder characterized by deficiency in mitochondrial DNA polymerase gamma (POLG) catalytic activity, refractory seizures, neurodegeneration, and liver disease. In two unrelated pedigrees of Alpers' syndrome, each affected child was found to carry a homozygous mutation in exon 17 of the POLG locus that led to a Glu873Stop mutation just upstream of the polymerase domain of the protein. In addition, each affected child was heterozygous for the G1681A mutation in exon 7 that led to an Ala467Thr substitution in POLG, within the linker region of the protein. Alpers disease consists of diffuse cerebral degeneration manifested as developmental delay, seizures, vomiting, and progressive neuromuscular deterioration, with liver disease and death. We report the clinical course of the liver disease, histologic progression of the hepatic lesions, and etiologic investigations in five patients (four girls, three kinships). All had grown and developed normally until seen at 6 to 36 months of age (mean 20 months), with vomiting (n = 5), progressive hypotonia (n = 3), or seizures (n = 2). All had been given anticonvulsants, including valproic acid in three. Liver disease was noted at a mean age of 35 months (range 9 to 67 months), with hepatomegaly (two patients), abnormal hepatic synthetic function (three) or transaminase values (three), and cirrhosis in one. Patients survived for a mean of 4.6 weeks (range 1 to 8 weeks) after the identification of liver disease; all died of hepatic failure. Results of evaluation for infectious and metabolic causes of liver disease and causes of degenerative neuromuscular disease were negative in all patients. Premortem liver biopsy specimens (n = 3) demonstrated an early lesion consisting of lobular disarray, microvesicular steatosis, periportal acute and chronic inflammation, and individual hepatocyte necrosis. Autopsy findings (n = 5) consisted of macrovesicular steatosis, massive hepatocyte dropout, and proliferation of bile ductular elements, with almost complete replacement of hepatocytes by proliferating bile ductular elements in two patients. Brain showed characteristic neuronal degeneration. We conclude that Alpers disease can be a cause of rapidly progressive liver failure in early childhood. Although the cause of this autosomal recessive disease is not known, it does not appear to be related to peroxisomal dysfunction.

Is vemurafenib effective for hairy-cell leukemia?

Yes, vemurafenib is highly effective in patients with relapsed or refractory hairy-cell leukemia.

[25815361, 26352686, 25774734, 25480661, 25148599, 24137951]

BACKGROUND: BRAF V600E is the genetic lesion underlying hairy-cell leukemia. We assessed the safety and activity of the oral BRAF inhibitor vemurafenib in patients with hairy-cell leukemia that had relapsed after treatment with a purine analogue or who had disease that was refractory to purine analogues. METHODS: We conducted two phase 2, single-group, multicenter studies of vemurafenib (at a dose of 960 mg twice daily)--one in Italy and one in the United States. The therapy was administered for a median of 16 weeks in the Italian study and 18 weeks in the U.S. study. Primary end points were the complete response rate (in the Italian trial) and the overall response rate (in the U.S. trial). Enrollment was completed (28 patients) in the Italian trial in April 2013 and is still open (26 of 36 planned patients) in the U.S. trial. RESULTS: The overall response rates were 96% (25 of 26 patients who could be evaluated) after a median of 8 weeks in the Italian study and 100% (24 of 24) after a median of 12 weeks in the U.S. study. The rates of complete response were 35% (9 of 26 patients) and 42% (10 of 24) in the two trials, respectively. In the Italian trial, after a median follow-up of 23 months, the median relapse-free survival was 19 months among patients with a complete response and 6 months among those with a partial response; the median treatment-free survival was 25 months and 18 months, respectively. In the U.S. trial, at 1 year, the progression-free survival rate was 73% and the overall survival rate was 91%. Drug-related adverse events were usually of grade 1 or 2, and the events most frequently leading to dose reductions were rash and arthralgia or arthritis. Secondary cutaneous tumors (treated with simple excision) developed in 7 of 50 patients. The frequent persistence of phosphorylated ERK-positive leukemic cells in bone marrow at the end of treatment suggests bypass reactivation of MEK and ERK as a resistance mechanism. CONCLUSIONS: A short oral course of vemurafenib was highly effective in patients with relapsed or refractory hairy-cell leukemia. (Funded by the Associazione Italiana per la Ricerca sul Cancro and others; EudraCT number, 2011-005487-13; ClinicalTrials.gov number NCT01711632.). MEDICAL HISTORY AND CLINICAL COURSE: A 42-year-old patient with hairy cell leukemia had been treated for 3 years by a hematologist in private practice. Initially the patient received 1 course of cladribine upon which the disease went into complete remission. 6 weeks ago a relapse was diagnosed and combination therapy with cladibrin and rituximab was initiated. Now the patient presented to the emergency room with shortness of breath and pain when breathing. INVESTIGATIONS, TREATMENT AND COURSE: In the chest x-ray, patchy infiltrates and pleural effusions were found on both sides. The subsequently performed computed tomography showed bilateral compactions with an Halo suspicious for fungal infiltrates. Upon admission to the hospital, an empirical antibiotic therapy with clarithromycin and piperacillin/tazobactam was initiated, which was later escalated to meropenem and linezolid. Additionally, an antifungal therapy with voriconazole was started and later switched to liposomal amphotericin B. At his admission, a positive aspergillus antigen could be detected in the microbiological laboratory. Under antimycotic treatment the aspergillus antigen was repeatedly negative. The patient presented with pronounced cytopenias and after a switch of therapy to vemurafenib and filgrastim, the hematopoiesis could only be stimulated insufficiently. The patient was transferred to the intensive care unit three days after admission with severe respiratory failure. He died on day 8 after admission. AUTOPSY AND DIAGNOSIS: Diagnosis was consistent with relapse of hairy cell leukemia with positive BRAF mutation and a bone marrow infiltration > 80 %. Autopsy revealed a significant hepato-splenomegaly, a lack of erythro-, granulo- and thrombopoiesis. Clots interspersed with fungal hyphae were found in both lungs and an infarction of the spleen with evidence of fungal hyphae was detected. The cultural findings post mortem on yeast or mold were negative. CONCLUSION: Patients with refractory hairy cell leukemia and prolonged neutropenia are at increased risk for systemic fungal infections. Therefore, prohylactic antimycotic therapy should be considered early in this group of patients. The therapeutic approach of vemurafenib in treatment-refractory hairy cell leukemia is promising and offers an additional treatment option. In the present case, the patient could unfortunately not be stabilized due to the septic complications. Hairy cell leukemia (HCL) shows unique clinicopathological and biological features. HCL responds well to purine analogs but relapses are frequent and novel therapies are required. BRAF-V600E is the key driver mutation in HCL and distinguishes it from other B-cell lymphomas, including HCL-like leukemias/lymphomas (HCL-variant and splenic marginal zone lymphoma). The kinase-activating BRAF-V600E mutation also represents an ideal therapeutic target in HCL. Here, we investigated the biological and therapeutic importance of the activated BRAF-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) pathway in HCL by exposing in vitro primary leukemic cells purified from 26 patients to clinically available BRAF (vemurafenib; dabrafenib) or MEK (trametinib) inhibitors. Results were validated in vivo in samples from vemurafenib-treated HCL patients within a phase 2 clinical trial. BRAF and MEK inhibitors caused, specifically in HCL (but not HCL-like) cells, marked MEK/ERK dephosphorylation, silencing of the BRAF-MEK-ERK pathway transcriptional output, loss of the HCL-specific gene expression signature, downregulation of the HCL markers CD25, tartrate-resistant acid phosphatase, and cyclin D1, smoothening of leukemic cells' hairy surface, and, eventually, apoptosis. Apoptosis was partially blunted by coculture with bone marrow stromal cells antagonizing MEK-ERK dephosphorylation. This protective effect could be counteracted by combined BRAF and MEK inhibition. Our results strongly support and inform the clinical use of BRAF and MEK inhibitors in HCL. The paper describes a case of a patient with refractory hairy cell leukemia. In spite of the absence of CD25 expression, the disease was classified as a classical form according to the WHO classification (2008), as also confirmed by the detection of BRAFV600E mutation. The disease was characterized by resistance to all lines of therapy (interferon-a, splenectomy, cladribin). Clinical and hematological remission was achieved within 2 months of administration of the BRAF kinase inhibitor vemurafenib.

Which are the inhibitors of histone methyltransferases?

In general, histone methyltransferases (HMTs) have no widely approved high-throughput screening assay format, and therefore reference inhibitors are not available for many of the HMTs. However, there are several selective HMT inhibitors: Trichostatin A (TSA), BIX-01294 and its derivative TM2-115, 2,4-pyridinedicarboxylic acid (2,4-PDCA), 3-deazaneplanocin A (DZNep), Psammaplin A (PsA) and Sulforaphane (SFN).

[22904200, 22665483, 22429326, 22420752, 21936531, 22357272, 23077658, 23557020, 22522911, 23379261, 23139138, 19860425, 21546573, 23092945, 20567762, 23011794, 22560341, 20556507, 22964322, 21940714, 22781932, 22924785]

BACKGROUND: Histone modifications and DNA methylation are two major factors in epigenetic phenomenon. Unlike the histone deacetylase inhibitors, which are known to exert radiosensitizing effects, there have only been a few studies thus far concerning the role of DNA methyltransferase (DNMT) inhibitors as radiosensitizers. The principal objective of this study was to evaluate the effects of DNMT inhibitors on the radiosensitivity of human cancer cell lines, and to elucidate the mechanisms relevant to that process. METHODS: A549 (lung cancer) and U373MG (glioblastoma) cells were exposed to radiation with or without six DNMT inhibitors (5-azacytidine, 5-aza-2'-deoxycytidine, zebularine, hydralazine, epigallocatechin gallate, and psammaplin A) for 18 hours prior to radiation, after which cell survival was evaluated via clonogenic assays. Cell cycle and apoptosis were analyzed via flow cytometry. Expressions of DNMT1, 3A/3B, and cleaved caspase-3 were detected via Western blotting. Expression of γH2AX, a marker of radiation-induced DNA double-strand break, was examined by immunocytochemistry. RESULTS: Pretreatment with psammaplin A, 5-aza-2'-deoxycytidine, and zebularine radiosensitized both A549 and U373MG cells. Pretreatment with psammaplin A increased the sub-G1 fraction of A549 cells, as compared to cells exposed to radiation alone. Prolongation of γH2AX expression was observed in the cells treated with DNMT inhibitors prior to radiation as compared with those treated by radiation alone. CONCLUSIONS: Psammaplin A, 5-aza-2'-deoxycytidine, and zebularine induce radiosensitivity in both A549 and U373MG cell lines, and suggest that this effect might be associated with the inhibition of DNA repair. Dynamic methylations and demethylations of histone lysine residues are important for gene regulation and are facilitated by histone methyltransferases and histone demethylases (HDMs). KDM5B/Jarid1B/PLU1 is an H3K4me3/me2-specific lysine demethylase belonging to the JmjC domain-containing family of histone demethylases (JHDMs). Several studies have linked KDM5B to breast, prostate and skin cancer, highlighting its potential as a drug target. However, most inhibitor studies have focused on other JHDMs, and inhibitors for KDM5B remain to be explored. Here, we report the expression, purification and characterization of the catalytic core of recombinant KDM5B (ccKDM5B, residues 1-769). We show that ccKDM5B, recombinantly expressed in insect cells, demethylates H3K4me3 and H3K4me2 in vitro. The kinetic characterization showed that ccKDM5B has an apparent Michaelis constant (K(m) (app) ) value of 0.5 μm for its trimethylated substrate H3(1-15)K4me3, a considerably increased apparent substrate affinity than reported for related HDMs. Despite the presence of a PHD domain, the catalytic activity was not affected by additional methylation at the H3K9 position, suggesting that in vitro chromatin cross-talk between H3K4 and H3K9 does not occur for ccKDM5B. Inhibition studies of ccKDM5B showed both in vitro and in cell inhibition of ccKDM5B by 2,4-pyridinedicarboxylic acid (2,4-PDCA) with a potency similar to that reported for the HDM KDM4C. Structure-guided sequence alignment indicated that the binding mode of 2,4-PDCA is conserved between KDM4A/C and KDM5B. Histone H3-lysine79 (H3K79) methyltransferase DOT1L plays critical roles in normal cell differentiation as well as initiation of acute leukemia. We used structure- and mechanism-based design to discover several potent inhibitors of DOT1L with IC(50) values as low as 38 nM. These inhibitors exhibit only weak or no activities against four other representative histone lysine and arginine methyltransferases, G9a, SUV39H1, PRMT1 and CARM1. The X-ray crystal structure of a DOT1L-inhibitor complex reveals that the N6-methyl group of the inhibitor, located favorably in a predominantly hydrophobic cavity of DOT1L, provides the observed high selectivity. Structural analysis shows that it will disrupt at least one H-bond and/or have steric repulsion for other histone methyltransferases. These compounds represent novel chemical probes for biological function studies of DOT1L in health and disease. The Epstein-Barr virus (EBV) predominantly establishes latent infection in B cells, and the reactivation of the virus from latency is dependent on the expression of the viral BZLF1 protein. The BZLF1 promoter (Zp) normally exhibits only low basal activity but is activated in response to chemical or biological inducers, such as 12-O-tetradecanoylphorbol-13-acetate (TPA), calcium ionophores, or histone deacetylase (HDAC) inhibitors. In some cell lines latently infected with EBV, an HDAC inhibitor alone can induce BZLF1 transcription, while the treatment does not enhance expression in other cell lines, such as B95-8 or Raji cells, suggesting unknown suppressive mechanisms besides histone deacetylation in those cells. Here, we found the epigenetic modification of the BZLF1 promoter in latent Raji cells by histone H3 lysine 27 trimethylation (H3K27me3), H3K9me2/me3, and H4K20me3. Levels of active markers such as histone acetylation and H3K4me3 were low in latent cells but increased upon reactivation. Treatment with 3-deazaneplanocin A (DZNep), an inhibitor of H3K27me3 and H4K20me3, significantly enhanced the BZLF1 transcription in Raji cells when in combination with an HDAC inhibitor, trichostatin A (TSA). The knockdown of Ezh2 or Suv420h1, histone methyltransferases for H3K27me3 or H4K20me3, respectively, further proved the suppression of Zp by the methylations. Taken together, the results indicate that H3K27 methylation and H4K20 methylation are involved, at least partly, in the maintenance of latency, and histone acetylation and H3K4 methylation correlate with the reactivation of the virus in Raji cells. Enhancer of zeste homolog 2 (EZH2) is the catalytic subunit of the Polycomb-repressive complex 2 (PRC2) that epigenetically silences gene transcription through histone H3 lysine trimethylation (H3K27me3). EZH2 has been implicated in stem cell maintenance and is overexpressed in hematological and solid malignancie`s including malignant glioma. EZH2 is thought to promote tumor progression by silencing tumor suppressor genes. Hence pharmacological disruption of the PRC2 is an attractive therapeutic strategy for cancer treatment. Here we show that EZH2 is expressed in human glioma and correlates with malignancy. Silencing of EZH2 reduced glioma cell proliferation and invasiveness. While we did not observe induction of cell cycle-associated tumor suppressor genes by silencing or pharmacological inhibition of EZH2, microarray analyses demonstrated a strong transcriptional reduction of the AXL receptor kinase. Neither histone nor DNA methylation appeared to be involved in the positive regulation of AXL by EZH2. Silencing AXL mimicked the antiinvasive effects of EZH2 knockdown. Finally, AXL expression is found in human gliomas with high EZH2 expression. Collectively these data suggest that EZH2 drives glioma invasiveness via transcriptional control of AXL independent of histone or DNA methylation. BACKGROUND: Estrogen receptor-α (ERα)-negative breast cancer is clinically aggressive and normally does not respond to conventional estrogen target-directed therapies. The soybean isoflavone, genistein (GE), has been shown to prevent and inhibit breast cancer and recent studies have suggested that GE can enhance the anticancer capacity of an estrogen antagonist, tamoxifen (TAM), especially in ERα-positive breast cancer cells. However, the role of GE in ERα-negative breast cancer remains unknown. METHODS: We have evaluated the in vitro and in vivo epigenetic effects of GE on ERα reactivation by using MTT assay, real-time reverse transcription-polymerase chain reaction (RT-PCR) assay, western-blot assay, immunoprecipitation (ChIP) assay, immunohistochemistry and epigenetic enzymatic activity analysis. Preclinical mouse models including xenograft and spontaneous breast cancer mouse models were used to test the efficacy of GE in vivo. RESULTS: We found that GE can reactivate ERα expression and this effect was synergistically enhanced when combined with a histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), in ERα-negative MDA-MB-231 breast cancer cells. GE treatment also re-sensitized ERα-dependent cellular responses to activator 17β-estradiol (E2) and antagonist TAM. Further studies revealed that GE can lead to remodeling of the chromatin structure in the ERα promoter thereby contributing to ERα reactivation. Consistently, dietary GE significantly prevented cancer development and reduced the growth of ERα-negative mouse breast tumors. Dietary GE further enhanced TAM-induced anti-cancer efficacy due at least in part to epigenetic ERα reactivation. CONCLUSIONS: Our studies suggest that soybean genistein can epigenetically restore ERα expression, which in turn increases TAM-dependent anti-estrogen therapeutic sensitivity in vitro and in vivo. The results from our studies reveal a novel therapeutic combination approach using bioactive soybean product and anti-hormone therapy in refractory ERα-negative breast cancer which will provide more effective options in breast cancer therapy. This study reports the pharmacokinetics and tissue distribution of a novel histone deacetylase and DNA methyltransferase inhibitor, psammaplin A (PsA), in mice. PsA concentrations were determined by a validated LC-MS/MS assay method (LLOQ 2 ng/mL). Following intravenous injection at a dose of 10 mg/kg in mice, PsA was rapidly eliminated, with the average half-life (t(1/2, λn)) of 9.9 ± 1.4 min and the systemic clearance (CL(s)) of 925.1 ± 570.1 mL/min. The in vitro stability of PsA was determined in different tissue homogenates. The average degradation t(1/2) of PsA in blood, liver, kidney and lung was found relatively short (≤ 12.8 min). Concerning the in vivo tissue distribution characteristics, PsA was found to be highly distributed to lung tissues, with the lung-to-serum partition coefficients (K(p)) ranging from 49.9 to 60.2. In contrast, PsA concentrations in other tissues were either comparable with or less than serum concentrations. The high and specific lung targeting characteristics indicates that PsA has the potential to be developed as a lung cancer treatment agent. A copper-mediated aerobic coupling reaction enables direct amidation of heterocycles or aromatics having weakly acidic C-H bonds with a variety of nitrogen nucleophiles. These reactions provide efficient access to many biologically important skeletons, including ones with the potential to serve as inhibitors of HMTs. Cancer-testis antigens (CTA), such as NY-ESO-1, MAGE-A1, and MAGE-A3, are immunogenic proteins encoded by genes, which are normally expressed only in male germ cells but are activated by ill-defined epigenetic mechanisms in human tumors, including lung cancers. Previously, we reported induction of these CTAs in cancer cells, but not normal cells, by DNA-demethylating agents and histone deacetylase inhibitors using clinically achievable exposure conditions. In the present study, we evaluated chromatin alterations associated with repression/activation of cancer-testis genes in lung cancer cells to further develop gene-induction regimens for cancer immunotherapy. Repression of NY-ESO-1, MAGE-A1, and MAGE-A3 coincided with DNA hypermethylation, recruitment, and binding of polycomb-group proteins, and histone heterochromatin modifications within the promoters of these genes. Derepression coincided with DNA demethylation, dissociation of polycomb proteins, and presence of euchromatin marks within the respective promoters. Short hairpin RNAs were used to inhibit several histone methyltransferases (KMT) and histone demethylases (KDM) that mediate histone methylation and repress gene expression. Knockdown of KMT6, KDM1, or KDM5B markedly enhanced deoxyazacytidine (DAC)-mediated activation of these cancer-testis genes in lung cancer cells. DZNep, a pharmacologic inhibitor of KMT6 expression, recapitulated the effects of KMT6 knockdown. Following DAC-DZNep exposure, lung cancer cells were specifically recognized and lysed by allogeneic lymphocytes expressing recombinant T-cell receptors recognizing NY-ESO-1 and MAGE-A3. Combining DNA-demethylating agents with compounds, such as DZNep, that modulate histone lysine methylation may provide a novel epigenetic strategy to augment cancer-testis gene expression as an adjunct to adoptive cancer immunotherapy. Satellite cells function as skeletal muscle stem cells to support postnatal muscle growth and regeneration following injury or disease. There is great promise for the improvement of muscle performance in livestock and for the therapy of muscle pathologies in humans by the targeting of myostatin (MSTN) in this cell population. Human diet contains many histone deacetylase (HDAC) inhibitors, such as the bioactive component sulforaphane (SFN), whose epigenetic effects on MSTN gene in satellite cells are unknown. Therefore, we aimed to investigate the epigenetic influences of SFN on the MSTN gene in satellite cells. The present work provides the first evidence, which is distinct from the effects of trichostatin A (TSA), that SFN supplementation in vitro not only acts as a HDAC inhibitor but also as a DNA methyltransferase (DNMT) inhibitor in porcine satellite cells. Compared with TSA and 5-aza-2'-deoxycytidine (5-aza-dC), SFN treatment significantly represses MSTN expression, accompanied by strongly attenuated expression of negative feedback inhibitors of the MSTN signaling pathway. miRNAs targeting MSTN are not implicated in posttranscriptional regulation of MSTN. Nevertheless, a weakly enriched myoblast determination (MyoD) protein associated with diminished histone acetylation in the MyoD binding site located in the MSTN promoter region may contribute to the transcriptional repression of MSTN by SFN. These findings reveal a new mode of epigenetic repression of MSTN by the bioactive compound SFN. This novel pharmacological, biological activity of SFN in satellite cells may thus allow for the development of novel approaches to weaken the MSTN signaling pathway, both for therapies of human skeletal muscle disorders and for livestock production improvement. Epigenetic factors such as histone methylation control the developmental progression of malaria parasites during the complex life cycle in the human host. We investigated Plasmodium falciparum histone lysine methyltransferases as a potential target class for the development of novel antimalarials. We synthesized a compound library based upon a known specific inhibitor (BIX-01294) of the human G9a histone methyltransferase. Two compounds, BIX-01294 and its derivative TM2-115, inhibited P. falciparum 3D7 parasites in culture with IC(50) values of ~100 nM, values at least 22-fold more potent than their apparent IC(50) toward two human cell lines and one mouse cell line. These compounds irreversibly arrested parasite growth at all stages of the intraerythrocytic life cycle. Decrease in parasite viability (>40%) was seen after a 3-h incubation with 1 µM BIX-01294 and resulted in complete parasite killing after a 12-h incubation. Additionally, mice with patent Plasmodium berghei ANKA strain infection treated with a single dose (40 mg/kg) of TM2-115 had 18-fold reduced parasitemia the following day. Importantly, treatment of P. falciparum parasites in culture with BIX-01294 or TM2-115 resulted in significant reductions in histone H3K4me3 levels in a concentration-dependent and exposure time-dependent manner. Together, these results suggest that BIX-01294 and TM2-115 inhibit malaria parasite histone methyltransferases, resulting in rapid and irreversible parasite death. Our data position histone lysine methyltransferases as a previously unrecognized target class, and BIX-01294 as a promising lead compound, in a presently unexploited avenue for antimalarial drug discovery targeting multiple life-cycle stages. Epidemiological studies suggest an important link between obesity and thyroid cancer. The adipose tissue-derived polypeptide leptin acting via leptin receptor may modulate cell migration of thyroid cancer cells. Previously we have demonstrated that leptin receptor is overexpressed in papillary thyroid cancer and is associated with tumor aggressiveness. The present study was undertaken to explore the possible regulatory factors which would influence leptin receptor expression in papillary thyroid cancer cells. We found that DNA methyltransferase inhibitor (5-Aza-2'-deoxycytidine) and histone deacetylase inhibitor (trichostatin A) reduced leptin receptor expression. Conversely, insulin upregulated leptin receptor expression in a time- and dose-dependent manner. Hypoxia-mimicking agent (cobalt chloride) had no effect on leptin receptor expression. Taken together, our study provides evidence that epigenetic events and insulin stimulation take part in regulation of leptin receptor expression in papillary thyroid cancer cells. BACKGROUND: Histone deacetylase (HDAC) inhibitors are a group of small chemical molecules that inhibit histone deacetylase. At cell level, HDAC inhibitors have multiple biological effects such as cell cycle arrest, apoptosis, cell differentiation and auotophagy. At molecular level, HDAC inhibitors cause histone and nonhistone acetylation and induce gene expression. HDAC inhibitors are widely used in cancer therapy because of its function of inducing apoptosis. However, the mechanisms of apoptosis effect are not fully understood. TSA is a classical HDAC inhibitor and widely used in epigenetic and anti-cancer research. In this study, we selected Trichostatin A (TSA) to investigate the mechanisms of HDAC inhibitors apoptotic effect on cancer cells. METHODS: Cervical cancer cell lines such as Hela, Caski and normal human keratinocyte line HaCaT were treated with various concentrations of TSA. Crystal violent assay and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay were performed to determine cell number. PARP cleavage and FITC-AnexinV were performed to determine apoptosis. DNA-methyltransferase (DNMT)1, DNMT3A and DNMT3B were determined by regular PCR, qPCR and Western Blotting. Small interfering RNA (SiRNAi) was used to knock down DNMT3B. RESULTS: HDAC inhibitors only induce cervical cancer cell apoptosis. At 1 µmol/L of TSA, 86% of Hela cell and 76% of Caski went apoptosis. For normal cells, HDAC inhibitors have no cytotoxic effect at therapeutic dosage, (90.0 ± 8.4)% of normal cell survive after treated with 1 µmol/L of TSA. We compared 1 µmol/L group with untreated control with t-test. There was no significance between 1 µmol/L group and untreated control for normal cell (P > 0.05). HDAC inhibitors decreased DNMT3B in cancer cell but not in normal cell. Manually knock-down of DNMT3B induced Hela and Caski cell apoptosis. More than 99% of Hela and Caski cell went apoptosis after deprived of DNMT3B. CONCLUSIONS: DNMT3B was essential to cervical cancer cell survival. Down-regulated DNMT3B by HDAC inhibitors may play an important role in the toxicity of HDAC inhibitors on cervical cancer cells. Histone posttranslational modifications are among the epigenetic mechanisms that modulate chromatin structure and gene transcription. Histone methylation and demethylation are dynamic processes controlled respectively by histone methyltransferases (HMTs) and demethylases (HDMs). Several HMTs and HDMs have been implicated in cancer, inflammation, and diabetes, making them attractive targets for drug therapy. Hence, the discovery of small-molecule modulators for these two enzyme classes has drawn significant attention from the pharmaceutical industry. Herein, the authors describe the development and optimization of homogeneous LANCE Ultra and AlphaLISA antibody-based assays for measuring the catalytic activity of two epigenetic enzymes acting on lysine 4 of histone H3: SET7/9 methyltransferase and LSD1 demethylase. Both the SET7/9 and LSD1 assays were designed as signal-increase assays using biotinylated peptides derived from the N-terminus of histone H3. In addition, the SET7/9 assay was demonstrated using full-length histone H3 protein as substrate in the AlphaLISA format. Optimized assays in 384-well plates are robust (Z' factors ≥0.7) and sensitive, requiring only nanomolar concentrations of enzyme and substrate. All assays allowed profiling of known SET7/9 and LSD1 inhibitors. The results demonstrate that the optimized LANCE Ultra and AlphaLISA assay formats provide a relevant biochemical screening approach toward the identification of small-molecule inhibitors of HMTs and HDMs that could lead to novel epigenetic therapies.

What is the main characteristic of Amyotrophic Lateral Sclerosis?

Amyotrophic lateral sclerosis (ALS) is a progressive degeneration of upper and lower motor neurons.

[16228969, 8959997, 17128093, 25384799]

There are four main hypotheses about the cause of ALS: excitotoxicity linked to glutamate receptor overactivation; mutation of the superoxide dismutase gene; production of autoantibodies to calcium channels; neurofilament accumulation. The motoneuron degeneration characteristic of ALS could be caused by any one or a combination of these mechanisms. Future therapeutic approaches should be based on these mechanisms and given in combination so that different levels of the degenerative process are targeted. Protection against excitotoxicity could be achieved with a combination of pharmacologic agents having neuroprotective activity, such as antiglutamate agents (e.g., riluzole), N-methyl-D-aspartate (NMDA) and non-NMDA antagonists, free-radical scavengers, calcium-channel blockers, and neurotrophic factors. Gene transfer is a possible future approach when causative mutations are identified. Transfer of genes encoding neuroprotective agents or genetically modified cells stably expressing these agents is another possible strategy. Amyotrophic lateral sclerosis (ALS) is a progressive degeneration of upper and lower motor neurons. In the absence of any validated biological marker, the diagnosis of ALS depends upon recognition of characteristic symptoms and signs together with supportive electrophysiological findings. The diagnosis of ALS is easy to recognize in its fully developed form but during the early stages both false positive and false negative diagnoses are common. In clinical practice, diagnostic difficulties mostly arise with patients who present either with only upper motor neuron, or with only lower motor neuron signs. It may be difficult to distinguish ALS with clinically predominant lower motor neuron involvement from alternative diagnoses including spinal atrophies of adult onset, Kennedy's disease, inclusion body myositis and motor neuropathies with conduction blocks. The diagnosis of ALS related syndromes (progressive muscular atrophy, primary lateral sclerosis and progressive bulbar palsy) requires the elimination of alternate diagnoses. This paper reviews the main characteristics of diseases mimicking ALS and the atypical subsets of ALS. Amyotrophic lateral sclerosis is the most common adult-onset motor neuron disease and evidence from mice expressing amyotrophic lateral sclerosis-causing SOD1 mutations suggest that neurodegeneration is a non-cell autonomous process where microglial cells influence disease progression. However, microglial-derived neurotoxic factors still remain largely unidentified in amyotrophic lateral sclerosis. With excitotoxicity being a major mechanism proposed to cause motor neuron death in amyotrophic lateral sclerosis, our hypothesis was that excessive glutamate release by activated microglia through their system [Formula: see text] (a cystine/glutamate antiporter with the specific subunit xCT/Slc7a11) could contribute to neurodegeneration. Here we show that xCT expression is enriched in microglia compared to total mouse spinal cord and absent from motor neurons. Activated microglia induced xCT expression and during disease, xCT levels were increased in both spinal cord and isolated microglia from mutant SOD1 amyotrophic lateral sclerosis mice. Expression of xCT was also detectable in spinal cord post-mortem tissues of patients with amyotrophic lateral sclerosis and correlated with increased inflammation. Genetic deletion of xCT in mice demonstrated that activated microglia released glutamate mainly through system [Formula: see text]. Interestingly, xCT deletion also led to decreased production of specific microglial pro-inflammatory/neurotoxic factors including nitric oxide, TNFa and IL6, whereas expression of anti-inflammatory/neuroprotective markers such as Ym1/Chil3 were increased, indicating that xCT regulates microglial functions. In amyotrophic lateral sclerosis mice, xCT deletion surprisingly led to earlier symptom onset but, importantly, this was followed by a significantly slowed progressive disease phase, which resulted in more surviving motor neurons. These results are consistent with a deleterious contribution of microglial-derived glutamate during symptomatic disease. Therefore, we show that system [Formula: see text] participates in microglial reactivity and modulates amyotrophic lateral sclerosis motor neuron degeneration, revealing system [Formula: see text] inactivation, as a potential approach to slow amyotrophic lateral sclerosis disease progression after onset of clinical symptoms.

Which genes are regulated by MEF-2 in the heart?

COX-2, ANF, estrogen receptor (ER)alpha gene, calsequestrin gene, casq2, cTnT, MCK, alpha-cardiac actin, sarco(endo)plasmic reticulum Ca2+-ATPase, SERCA, MLC-2, alpha-cardiac myosin heavy chain gene, phosphoglycerate mutase and PGAM-M are regulated by MEF-2 in the heart

[7982978, 8366095, 19893013, 15491989, 10794526, 16049055, 17518763, 12805933, 21244855, 21812548, 1532229, 15040454, 20075332, 8035789, 1328854, 8321243, 11770083, 8977381, 8449897, 10998641, 8674419, 9043061, 17938175]

Expression of the mouse alpha-cardiac actin gene in skeletal and cardiac muscle is regulated by enhancers lying 5' to the proximal promoter. Here we report the characterization of a cardiac-specific enhancer located within -2.354/-1.36 kbp of the gene, which is active in cardiocytes but not in C2 skeletal muscle cells. In vivo it directs reporter gene expression to the adult heart, where the proximal promoter alone is inactive. An 85-bp region within the enhancer is highly conserved between human and mouse and contains a central AT-rich site, which is essential for enhancer activity. This site binds myocyte enhancer factor (MEF)2 factors, principally MEF2D and MEF2A in cardiocyte nuclear extracts. These results are discussed in the context of MEF2 activity and of the regulation of the alpha-cardiac actin locus. We have characterized the specific DNA regulatory elements responsible for the function of the human cardiac troponin C gene (cTnC) muscle-specific enhancer in myogenic cells. We used functional transient transfection assays with deletional and site-specific mutagenesis to evaluate the role of the conserved sequence elements. Gel electrophoresis mobility shift assays (EMSA) demonstrated the ability of the functional sites to interact with nuclear proteins. We demonstrate that three distinct transcription activator binding sites commonly found in muscle-specific enhancers (a MEF-2 site, a MEF-3 site, and at least four redundant E-box sites) all contribute to full enhancer activity but a CArG box does not. Mutation of either the MEF-2 or MEF-3 sites or deletion of the E-boxes reduces expression by 70% or more. Furthermore, the MEF-2 site and the E-boxes specifically bind, respectively, to MEF-2 and myogenic determination factors derived from nuclear extracts. EMSA assays using a MEF-3 containing oligonucleotide revealed indistinguishable separation patterns with extracts from myogenic cells and nonmyogenic cells. These data suggest that expression of the cTnC gene in slow-twitch skeletal muscle is sustained through complex interactions at the 3'Ile enhancer between muscle-specific and nontissue-specific transcription factors: either a myogenic bHLH complex or MEF-2 can activate transcription but only in the presence of a third transcriptional activator that appears not to be muscle specific. We conclude from these observations that the cTnC 3'Ile element is a composite enhancer that functions through the combined interactions of at least five regulatory elements and their cognate binding factors: three or four E-boxes, a MEF-2 site, and a MEF-3 site. The data support the notion that all of these sites contribute to enhancer function in cell systems in an additive way but that none are absolutely required for enhancer activity. The data imply that the levels of transcription of cTnC in myogenic tissues in which the activities of one of the transcriptional factors is lacking would be partially but not wholly suppressed. Our data support the critical role of E-box sites in conjunction with the adjacent elements. Hence, we assign CTnC gene regulation to the "ordinary" rather than to the "novel" category of transcriptional regulation during skeletal myogenesis. MCAT elements are essential for cardiac gene expression during development. Avian transcriptional enhancer factor-1 (TEF-1) proteins are muscle-enriched and contribute to MCAT binding activities. However, direct activation of MCAT-driven promoters by TEF-1-related proteins has not been uniformly achieved. Divergent TEF (DTEF)-1 is a unique member of the TEF-1 multigene family with abundant transcripts in the heart but not in skeletal muscle. Herein we show that DTEF-1 proteins are highly expressed in the heart. Protein expression is activated at very early stages of chick embryogenesis (Hamburger-Hamilton stage 4, 16-18 h), after which DTEF-1 becomes abundant in the sinus venosus and is expressed in the trabeculated ventricular myocardium and ventricular outflow tracts. By chromatin immunoprecipitation, DTEF-1 interacts with the cardiac troponin T (cTnT) promoter in vivo. DTEF-1 also interacts with MEF- 2 by coimmunoprecipitation and independently or cooperatively (with MEF-2) trans-activates the cTnT promoter. DTEF-1 isoforms do not activate the cTnT promoter in fibroblasts or skeletal muscle. DTEF-1 expression occurs very early in chick embryogenesis (16-18 h), preceding sarcomeric protein expression, and it activates cardiac promoters. As such, DTEF-1 may be an early marker of the myocardial phenotype. DTEF-1 trans-activates the cTnT promoter in a tissue-specific fashion independent of AT-rich, MEF-2, or GATA sites. The observed spatial pattern suggests decreasing levels of expression from the cardiac inlet to the ventricular outflow tracts, which may mark a cardiogenic or differentiation pathway that parallels the direction of flow through the developing chick heart. To understand the transcriptional regulatory network in eukaryotic cells, it is essential to identify functional cis-regulatory sequences that interact with trans-acting factors. A number of algorithms have been developed to predict common cis-regulatory elements for co-regulated genes with similar expression patterns. However, previous methods usually deal with disjoint gene groups partitioned or clustered by arbitrary cutoffs, which might cause information losses. To preclude the defining step of gene set, we adopted enrichment analysis and termed the method binding site enrichment analysis (BSEA). BSEA was first applied for publicly available ChIP-on-chip data of c-MYC, MAX and E2F transcription factors, identifying significant enrichment for signatures of corresponding factors and potential co-activators. Using time-scaled expression profiling of 3T3-L1 adipogenesis, we observed enrichment for signatures of known adipogenic factors such as C/EBPalpha, C/EBPbeta and PPARgamma, temporally coincident with previous reports. BSEA was also applied to tissue-specific expression profiles of human and mouse, identifying well-known tissue-specific transcription factors such as HNF-4 in liver and MEF-2 in heart along with other putative tissue-specific regulators. With extended versatility coping with various kinds of microarray dataset, BSEA can identify key regulators for global microarray data in which transcriptional regulation plays a major role. As a generalized method, BSEA would help to elucidate the transcriptional regulatory networks, the primary challenges in functional genomics. Heparin-binding EGF-like growth factor (HB-EGF) is a member of the EGF family that binds to and activates the EGF receptor. Transactivated by angiotensin II, ET-1, and various growth factors in cardiomyocytes, HB-EGF is known to induce cardiac hypertrophy via the PI3K-Akt, MAP kinase, and JAK-STAT pathways. However, little is known about the potential involvement of the ERK5 pathway in HB-EGF-induced cardiac hypertrophy. In the present report, we identify and characterize a novel MEK5-ERK5 pathway that is involved in HB-EGF-induced cardiomyocyte hypertrophy. HB-EGF (10ng/ml) significantly increased [(3)H]-leucine incorporation and atrial natriuretic factor (ANF) mRNA expression in H9c2 cells. In addition, HB-EGF activated a MEK5-ERK5 pathway. Pretreatment with the EGFR inhibitor AG1478 attenuated the activation of ERK5. Blockade of MEK5-ERK5 signaling using MEK5 siRNA reduced the ability of HB-EGF to increase cell size and the expression of ANF mRNA, suggesting the involvement of an EGFR-ERK5 pathway in HB-EGF-induced cardiomyocyte hypertrophy. We further analyzed cyclooxygenase-2 (COX-2). HB-EGF enhanced the expression of COX-2, a response mediated by MEK5-ERK5 signaling, while the COX-2 inhibitor rofecoxib attenuated HB-EGF-induced ANF mRNA expression, suggesting that COX-2 is also associated with HB-EGF-induced cardiomyocyte hypertrophy. It has been known that ERK5 activates the myocyte enhancer factor (MEF) 2 family of transcription factor, we next tested whether activation of MEF2A contributes to HB-EGF-induced COX-2 expression. Inhibition of MEF2A using siRNA attenuated HB-EGF-induced COX-2, ANF expression and cell size. In conclusion, HB-EGF induces cardiomyocyte hypertrophy through an EGFR-ERK5-MEF2A-COX-2 pathway. Our findings will help us to better understand the molecular mechanisms behind HB-EGF-induced cardiomyocyte hypertrophy. The muscle-CAT (M-CAT) promoter element is found on promoters of most muscle-specific cardiac genes, but its role in cardiac pathology is poorly understood. Here we studied whether the M-CAT element is involved in hypertrophic process activated by mechanical stretch, and identified the intracellular pathways mediating the response. When an in vitro stretch model of cultured neonatal rat cardiomyocytes and luciferase reporter construct driven by rat B-type natriuretic peptide (BNP) promoter were used, mutation of M-CAT element inhibited not only the basal reporter activity (88%), but also the stretch-activated BNP transcription (58%, p < 0.001). Stretch-induced BNP promoter activation was associated with an increase in transcriptional enhancer factor-1 (TEF-1) binding activity after 24 h mechanical stretch (p < 0.05). Inhibition of mitogen-activated protein kinases ERK, JNK, or p38 attenuated stretch-induced BNP activation. Interestingly, as opposed to p38 and JNK, inhibition of ERK had no additional effect on transcriptional activity of BNP promoter harboring the M-CAT mutation, suggesting a pivotal role for ERK in regulating stretch-induced BNP transcription via M-CAT binding site. Finally, immunoprecipitation studies showed that mechanical stretch induced myocyte enhancer factor-2 (MEF-2) binding to TEF-1. These data suggest a central role for M-CAT element in regulation of mechanical stretch-induced hypertrophic response via ERK activation. Recent studies have identified a conserved 28-bp element (HF-1) within the rat cardiac MLC-2 gene which confers cardiac muscle-specific and inducible expression during myocardial cell hypertrophy. Utilizing a combination of independent experimental approaches, this study characterizes two cardiac nuclear factors which bind to HF-1, a ubiquitous factor (HF-1a), and an A + T-rich binding factor (HF-1b) which is preferentially expressed in differentiated cardiac and skeletal muscle cells. The HF-1a binding site is located in a core region of the 28-bp conserved element, immediately upstream from the A + T-rich HF-1b site, which is homologous to the MEF-2 site found in a number of muscle genes. By a number of separate criteria (gel mobility shift, competition, and mutagenesis studies), HF-1b and MEF-2 appear to be indistinguishable and thus are either identical or closely related muscle factors. Transient assays of luciferase reporter genes containing point mutations throughout the 28-bp HF-1 regulatory element document the importance of both the HF-1a and HF-1b sites in transient assays in ventricular muscle cells. In the native 250-bp MLC-2 promoter fragment, mutations in the single E box had little effect on cardiac muscle specificity, while point mutations in either the HF-1a or HF-1b binding site significantly reduced promoter activity, underscoring the importance of both the HF-1a and HF-1b sites in the transcriptional activation of this cardiac muscle gene. Thus, this study provides evidence that a novel, ubiquitous factor (HF-1a) and a muscle factor (HF-1b/MEF-2) can form a novel, E-box-independent pathway for muscle-specific expression in ventricular cardiac muscle cells. RATIONALE: Mitogen-activated protein kinase (MAPK) pathways provide a critical connection between extrinsic and intrinsic signals to cardiac hypertrophy. Extracellular signal-regulated protein kinase (ERK)5, an atypical MAPK is activated in the heart by pressure overload. However, the role of ERK5 plays in regulating hypertrophic growth and hypertrophy-induced apoptosis is not completely understood. OBJECTIVE: Herein, we investigate the in vivo role and signaling mechanism whereby ERK5 regulates cardiac hypertrophy and hypertrophy-induced apoptosis. METHODS AND RESULTS: We generated and examined the phenotypes of mice with cardiomyocyte-specific deletion of the erk5 gene (ERK5(cko)). In response to hypertrophic stress, ERK5(cko) mice developed less hypertrophic growth and fibrosis than controls. However, increased apoptosis together with upregulated expression levels of p53 and Bad were observed in the mutant hearts. Consistently, we found that silencing ERK5 expression or specific inhibition of its kinase activity using BIX02189 in neonatal rat cardiomyocytes (NRCMs) reduced myocyte enhancer factor (MEF)2 transcriptional activity and blunted hypertrophic responses. Furthermore, the inhibition of MEF2 activity in NRCMs using a non-DNA binding mutant form of MEF2 was found to attenuate the ERK5-regulated hypertrophic response. CONCLUSIONS: These results reveal an important function of ERK5 in cardiac hypertrophic remodeling and cardiomyocyte survival. The role of ERK5 in hypertrophic remodeling is likely to be mediated via the regulation of MEF2 activity. Cardiac muscle-restricted expression of the alpha-myosin heavy-chain (alpha-MHC) gene is regulated by multiple elements in the proximal enhancer/promoter. Within this region, an M-CAT site and an A-rich site were identified as potential regulatory elements. Site-specific mutations in each site, individually, reduced activity from the wild-type promoter by approximately 85% in the adult rat heart, demonstrating that these sites were positive regulatory elements. alpha-MHC, beta-MHC, and chicken cardiac troponin T (cTnT) M-CAT sites interacted with an M-CAT-binding factor (MCBF) from rat heart nuclear extracts that was immunologically related to transcriptional enhancer factor 1, a factor that binds within the simian virus 40 enhancer. The factor that bound the A-rich region (ARF) was antigenically related to the RSRF family of proteins, ARF was distinct from myocyte-specific enhancer factor 2 (MEF-2) on the basis of DNA-binding specificity and developmental expression. Like MEF-2, ARF DNA-binding activity was present in the heart and brain; however, no ARF activity was detected in extracts from skeletal muscle or C2C12 myotubes. MCBF and ARF DNA-binding activities were developmentally regulated with peak levels in the 1- to 2-day neonatal heart. The activity of both factors increased nearly fivefold in adult rat hearts subjected to a pressure overload. By comparison, the levels of alpha-MHC binding factor 2 did not change during hypertrophy. Binding sites for MCBF and ARF are present in several genes that are upregulated during cardiac hypertrophy. Our results suggest that these factors participate in the alterations in gene expression that occur during cardiac development and hypertrophy. In order to analyze the transcriptional regulation of the muscle-specific subunit of the human phosphoglycerate mutase (PGAM-M) gene, chimeric genes composed of the upstream region of the PGAM-M gene and the bacterial chloramphenicol acetyltransferase (CAT) gene were constructed and transfected into C2C12 skeletal myocytes, primary cultured cardiac muscle cells, and C3H10T1/2 fibroblasts. The expression of chimeric reporter genes was restricted in skeletal and cardiac muscle cells. In C2C12 myotubes and primary cultured cardiac muscle cells, the segment between nucleotides -165 and +41 relative to the transcription initiation site was sufficient to confer maximal CAT activity. This region contains two E boxes and one MEF-2 motif. Deletion and substitution mutation analysis showed that a single MEF-2 motif but not the E boxes had a substantial effect on skeletal and cardiac muscle-specific enhancer activity and that the cardiac muscle-specific negative regulatory region was located between nucleotides -505 and -165. When the PGAM-M gene constructs were cotransfected with MyoD into C3H10T1/2, the profile of CAT activity was similar to that observed in C2C12 myotubes. Gel mobility shift analysis revealed that when the nuclear extracts from skeletal and cardiac muscle cells were used, the PGAM-M MEF-2 site generated the specific band that was inhibited by unlabeled PGAM-M MEF-2 and muscle creatine kinase MEF-2 oligomers but not by a mutant PGAM-M MEF-2 oligomer. These observations define the PGAM-M enhancer as the only cardiac- and skeletal-muscle-specific enhancer characterized thus far that is mainly activated through MEF-2. The AT-rich element MEF-2 plays an important role in the maintenance of the muscle-specific expression of a number of cardiac and skeletal muscle genes. In the MLC-2 gene, an AT-rich element (HF-1b) which contains a consensus MEF-2 site is required for cardiac tissue-specific expression. The present study reports the isolation and characterization of a cDNA which encodes a novel C2H2 zinc finger (HF-1b) that binds in a sequence-specific manner to the HF-1b/MEF-2 site in the MLC-2 promoter. A number of independent criteria suggest that this HF-1b zinc finger protein is a component of the endogenous HF-1b/MEF-2 binding activity in cardiac muscle cells and that it can serve as a transcriptional activator of the MLC-2 promoter in transient assays. These studies suggest that, in addition to the previously reported RSRF proteins, structurally divergent transcriptional factors can bind to MEF-2-like sites in muscle promoters. These results underscore the complexity of the regulation of the muscle gene program via these AT-rich elements in cardiac and skeletal muscle. Thyroid hormone (T3) increases the transcription of the sarcoplasmic reticulum Ca2+ adenosine triphosphatase (ATPase) gene (SERCA 2) through three thyroid hormone response elements. The existence of repetitive cis elements with different configurations is likely to serve specific functions such as interactions with nuclear transcription factors. In addition, the presence of different T3 receptor isoforms (T3Rs) may contribute to another level of complexity in providing specificity for T3 action. In this study, we investigated T3R alpha 1-vs. T3R beta 1-specific interactions with the myocyte enhancer-specific factor-2 (MEF-2) on the expression of the SERCA 2 gene in transient transfection assays in embryonal heart-derived H9c2 cells. MEF-2a in combination with either T3R alpha 1 or T3R beta 1 isoforms resulted in a 2.5-fold increase in SERCA 2 transgene expression in the absence of T3. Addition of T3 did not induce any further increase in SERCA 2 expression when T3R alpha 1 and MEF-2a expression vectors were cotransfected. In contrast, in the presence of T3R beta 1 and MEF-2, the addition of T3 increased chlorampenicol acetyltransferase activity by an additional 2.2-fold to a total 5.5-fold increase. The interaction between MEF-2a and T3R is transcription factor specific because another factor that binds to MEF-2 consensus sites (heart factor 1b) was not able to interact with T3R. In addition, MEF-2a failed to interact with other nuclear factors (cAMP response element-binding protein and Egr-1) that stimulate SERCA 2 gene transcription. In addition, we found that a single homologous thyroid hormone response element is not able to mediate the interactions between MEF-2a and T3Rs to increase SERCA 2 gene transcription. Our findings point to T3R isoform-specific interactions with a cell type-specific transcription factor (MEF-2) in the regulation of SERCA 2 gene expression. The intergenic region between the mouse alpha-cardiac myosin heavy chain and beta-myosin heavy chain genes has previously been shown to direct expression of the bacterial chloramphenicol acetyltransferase reporter gene in transgenic mice in a tissue-specific manner. Sequence analyses located a putative myocyte-specific enhancer-binding factor (MEF-2) site situated in the regulatory region of this gene proximal to the start site of transcription. The role of this element in directing the cardiac compartment-specific expression of the transgene was assessed. The polymerase chain reaction was used to perform substitution mutagenesis of the MEF-2 binding site, and lack of MEF-2 binding was confirmed by gel retardation assays. The resultant construct was used to generate transgenic mice. Surprisingly, transgene expression was not down-regulated, but was significantly increased in the hearts of the MEF-2 mutant mice. In addition, cardiac-specific expression of the transgene was perturbed with significant levels of ectopic expression occurring in the aorta. The molecular determinants that direct gene expression to the ventricles of the heart are for the most part unknown. Additionally, little data is available on how the anterior/posterior axis of the heart tube is determined and whether the left and right atrial and ventricular chambers are assigned as part of this process. Utilizing myosin light chain-2 ventricular promoter/beta-galactosidase reporter transgenes, we have determined the minimal cis-acting sequences required for ventricular-specific gene expression. In multiple independent transgenic mouse lines, we found that both a 250 base pair myosin light chain-2 ventricular promoter fragment, as well as a dimerized 28 bp sub-element (HF-1) containing binding sites for HF1a and HF1b/MEF2 factors, directed ventricular-specific reporter expression from as early as the endogenous gene, at day 7.5-8.0 post coitum. While the endogenous gene is expressed uniformly throughout both ventricles, the transgenes were expressed in a right ventricular/conotruncal dominant fashion, suggesting that they contain only a subset of the elements which respond to positional information in the developing heart tube. Expression of the transgene was cell autonomous and its temporospatial characteristics not affected by mouse strain/methylation state of the genome. To determine whether ventricular-specific expression of the transgene was dependent upon regulatory genes required for correct ventricular differentiation, the 250 base pair transgene was bred into both retinoid X receptoralpha and Nkx2-5 null backgrounds. The transgene was expressed in both mutant backgrounds, despite the absence of endogenous myosin light chain-2 ventricular transcript in Nkx2-5 null embryos. Ventricular specification, as judged by transgene expression, appeared to occur normally in both mutants. Thus, the HF-1 element, directs chamber-specific transcription of a transgene reporter independently of retinoid X receptoralpha and Nkx2-5, and defines a minimal combinatorial pathway for ventricular chamber gene expression. The patterned expression of this transgene may provide a model system in which to investigate the cues that dictate anterior-posterior (right ventricle/left ventricle) gradients during mammalian heart development.

Is there an association between TERT promoter mutation and survival of glioma patients?

Yes, TERT mutation is associated with survival of glioma patients and was suggested as a bio-marker of gliomas.

[24722048, 24937153, 25314060, 25081751, 26061753]

Frequent mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) and the promoter of telomerase reverse transcriptase (TERT) represent two significant discoveries in glioma genomics. Understanding the degree to which these two mutations co-occur or occur exclusively of one another in glioma subtypes presents a unique opportunity to guide glioma classification and prognosis. We analyzed the relationship between overall survival (OS) and the presence of IDH1/2 and TERT promoter mutations in a panel of 473 adult gliomas. We hypothesized and show that genetic signatures capable of distinguishing among several types of gliomas could be established providing clinically relevant information that can serve as an adjunct to histopathological diagnosis. We found that mutations in the TERT promoter occurred in 74.2% of glioblastomas (GBM), but occurred in a minority of Grade II-III astrocytomas (18.2%). In contrast, IDH1/2 mutations were observed in 78.4% of Grade II-III astrocytomas, but were uncommon in primary GBM. In oligodendrogliomas, TERT promoter and IDH1/2 mutations co-occurred in 79% of cases. Patients whose Grade III-IV gliomas exhibit TERT promoter mutations alone predominately have primary GBMs associated with poor median OS (11.5 months). Patients whose Grade III-IV gliomas exhibit IDH1/2 mutations alone predominately have astrocytic morphologies and exhibit a median OS of 57 months while patients whose tumors exhibit both TERT promoter and IDH1/2 mutations predominately exhibit oligodendroglial morphologies and exhibit median OS of 125 months. Analyzing gliomas based on their genetic signatures allows for the stratification of these patients into distinct cohorts, with unique prognosis and survival. OBJECTIVE: This study explored the effects of telomerase reverse transcriptase (TERT) promoter mutations on transcriptional activity of the TERT gene under hypoxic and temozolomide (TMZ) treatment conditions, and investigated the status and prognostic value of these mutations in gliomas. METHODS: The effect of TERT promoter mutations on the transcriptional activity of the TERT gene under hypoxic and TMZ treatment conditions was investigated in glioma cells using the luciferase assay. TERT promoter mutations were detected in 101 glioma samples (grades I-IV) and 49 other brain tumors by sequencing. TERT mRNA expression in gliomas was examined by real-time PCR. Hazard ratios from survival analysis of glioma patients were determined relative to the presence of TERT promoter mutations. RESULTS: Mutations in the TERT promoter enhanced gene transcription even under hypoxic and TMZ treatment conditions, inducing upregulation of TERT mRNA expression. Mutations were detected in gliomas, but not in meningiomas, pituitary adenomas, cavernomas, intracranial metastases, normal brain tissues, or peripheral blood of glioma patients. Patients with TERT promoter mutations had lower survival rates, even after adjusting for other known or potential risk factors, and the incidence of mutation was correlated with patient age. CONCLUSION: TERT promoter mutations were specific to gliomas. TERT promoter mutations maintained its ability of inducing high transcriptional activity even under hypoxic and TMZ treatment conditions, and the presence of mutations was associated with poor prognosis in glioma patients. These findings demonstrate that TERT promoter mutations are novel prognostic markers for gliomas that can inform prospective therapeutic strategies. Author information: (1)1] Sorbonne Universités, UMPC Univ Paris 06, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, Paris 75013, France [2] INSERM U 1127, Paris 75013, France [3] CNRS, UMR 7225, Paris 75013, France. (2)1] Sorbonne Universités, UMPC Univ Paris 06, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, Paris 75013, France [2] INSERM U 1127, Paris 75013, France [3] CNRS, UMR 7225, Paris 75013, France [4] National Neurological Institute C. Mondino, University of Pavia, 27100 Pavia, Italy. (3)1] Sorbonne Universités, UMPC Univ Paris 06, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, Paris 75013, France [2] INSERM U 1127, Paris 75013, France [3] CNRS, UMR 7225, Paris 75013, France [4] Institut du Cerveau et de la Moelle épinière (ICM), Plateforme de Génotypage Séquençage, Paris 75013, France. (4)Dipartimento di Neuro Oncologia Molecolare Fondazione I.R.C.C.S. Istituto Neurologico C. Besta, Milano 20134, Italy. (5)1] Institut du Cerveau et de la Moelle épinière (ICM), Plateforme de Génotypage Séquençage, Paris 75013, France [2] Onconeurothèque, Paris 75013, France. (6)1] Sorbonne Universités, UMPC Univ Paris 06, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, Paris 75013, France [2] INSERM U 1127, Paris 75013, France [3] CNRS, UMR 7225, Paris 75013, France [4] Onconeurothèque, Paris 75013, France. (7)Division of Genetics and Epidemiology, Institute of Cancer Research, Surrey SM2 5NG, UK. (8)1] Sorbonne Universités, UMPC Univ Paris 06, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, Paris 75013, France [2] INSERM U 1127, Paris 75013, France [3] CNRS, UMR 7225, Paris 75013, France [4] AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Neurologie 2, Paris 75013, France. (9)1] Sorbonne Universités, UMPC Univ Paris 06, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, Paris 75013, France [2] INSERM U 1127, Paris 75013, France [3] CNRS, UMR 7225, Paris 75013, France [4] Onconeurothèque, Paris 75013, France [5] AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Neurologie 2, Paris 75013, France. (10)1] Sorbonne Universités, UMPC Univ Paris 06, Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, Paris 75013, France [2] INSERM U 1127, Paris 75013, France [3] CNRS, UMR 7225, Paris 75013, France [4] Onconeurothèque, Paris 75013, France [5] AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Laboratoire de Neuropathologie R. Escourolle, Paris 75013, France. Recurrent mutations in the promoter region of telomerase reverse transcriptase (TERT) have been found in various cancers including diffuse gliomas. Mutations lead to TERT upregulation and are associated with aggressive clinical behavior in glioblastomas. However, the clinical significance of TERT promoter mutations in lower-grade gliomas remains undetermined. The aim of this study is to evaluate the status of TERT promoter and the respective prognostic significance in a cohort of 237 lower-grade gliomas comprising grades II and III astrocytomas, oligodendrogliomas, and oligoastrocytomas. Mutually exclusive mutations in TERT promoter, C228T and C250T, were identified in 16/105 (15%) diffuse astrocytomas, 16/63 (25%) anaplastic astrocytomas, 13/18 (72%) oligodendrogliomas, 3/3 (100%) anaplastic oligodendrogliomas, 17/45 (38%) oligoastrocytomas, and 2/3 (67%) anaplastic oligoastrocytomas. Mutations co-occurred with 1p/19q codeletion (P<0.001) and are associated with oligodendroglial histology (P<0.001). Kaplan-Meier's survival analysis showed that TERT promoter mutation (P=0.037), Isocitrate dehydrogenase (IDH) mutation (P<0.001), and 1p/19q codeletion (P<0.001) were associated with favorable overall survival (OS). In the subset of 116 IDH-mutated lower-grade gliomas lacking 1p/19q codeletion, 19 TERT promoter-mutated tumors exhibited longer progression-free survival (PFS) (P=0.027) and OS (P=0.004). Consistent with this observation, in the subset of 97 IDH-mutated astrocytomas, 14 TERT promoter-mutated tumors showed longer PFS (P=0.001) and OS (P=0.001). In contrast, among the subset of 74 IDH wild-type lower-grade gliomas with intact 1p/19q, TERT promoter mutation was associated with shorter PFS (P=0.001) and OS (P=0.001). Similarly, in the subset of 65 IDH wild-type astrocytomas, 16 TERT promoter-mutated tumors exhibited unfavorable PFS (P=0.007) and OS (P=0.008). Our results indicate that when combined with IDH status, TERT promoter mutation contributes to prognostic subgroups of lower-grade astrocytic tumors or 1p/19q intact lower-grade gliomas and this may further refine future molecular classification of lower-grade gliomas.

Which JAK (Janus kinase) inhibitor is approved for treatment of rheumatoid arthritis?

Tofacitinib (or CP690.550) is an oral JAK (Janus kinase) inhibitor that is approved for treatment of rheumatoid arthritis. Tofacitinib inhibits JAK family kinase members, in particular JAK1 and JAK3, achieving a broad limitation of inflammation by interfering with several cytokine receptors. Tofacitinib has also a proven efficacy as an immunosuppressive regimen after renal transplantation. GLPG-0634 and INCB18424 are other JAK kinase inhibitors that are being studied for treatment of rheumatoid arthritis.

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After two decades of research and development activity focussed on orally active kinase inhibitors, the first such drug (the JAK inhibitor Xeljanz, tofacitinib) was approved by the FDA in November 2012 for the treatment of rheumatoid arthritis (RA). There is an intense activity in many companies both on expanding the utility of JAK inhibitors in other auto-immune indications and in discovering inhibitors of the JAK family with different and more selective profiles. Progress is also being made with orally active Syk inhibitors. One such inhibitor (fostamatinib) is currently in large-scale phase 3 trials, and there are others in clinical development. The last two to three years have been transformative for kinase inhibitors in auto-immune diseases, as several inhibitors have finally progressed beyond phase 2 trials after so many failures on other targets. Thus, there are new treatment options for RA patients beyond existing oral DMARDs and parenteral biologics. The advent of anti-Tumor Necrosis Factor (TNF) therapy has changed the way of treating inflammatory bowel disease (IBD). However, primary and secondary failure are relatively frequent with all anti-TNF agents, which are available only as parenteral agents. Tofacitinib is an oral janus kinase (JAK) inhibitor that inhibits JAK family kinase members, in particular JAK1 and JAK3, achieving a broad limitation of inflammation by interfering with several cytokine receptors. It first proved its efficacy as an immunosuppressive regimen after renal transplantation, and was recently approved by the FDA for rheumatoid arthritis. First data in IBD are promising, especially in ulcerative colitis. Ongoing clinical trials in both UC and Crohn's disease (CD) are needed to further explore its efficacy in CD and to better assess its safety profile. INTRODUCTION: The JAK family comprises of the four non-receptor tyrosine kinases JAK1, JAK2, JAK3 and Tyk2, which play key, but differing, roles in cytokine receptor signal transduction. A non-selective JAK inhibitor, ruxolitinib, has recently been approved to treat myelofibrosis whereas tofacitinib is poised for approval to treat rheumatoid arthritis. Selective inhibition of JAK3, JAK1 or Tyk2 provides the opportunity to achieve clinical efficacy in the treatment of inflammatory diseases while reducing the risk of dose-limiting effects attributable to JAK2 inhibition. AREAS COVERED: This review considers the small number of published patent filings that claim either selective JAK1 or selective Tyk2 inhibitors. These are considered in the context of the considerably larger number of disclosures and patent filings claiming selective JAK2 or JAK3 inhibitors. EXPERT OPINION: The recent disclosure of the clinical efficacy of a selective JAK1 inhibitor (GLPG-0634) in rheumatoid arthritis and detailed disclosure of the some potent and highly selective JAK1 inhibitors provide a clear stimulus for further activity in this area. The availability of a selective Tyk2 inhibitor will provide the opportunity for better understanding of the physiological role of this kinase. Recent patent applications indicate that Tyk2 selectivity is achievable and Tyk2 inhibitors have potential in the treatment of multiple sclerosis. INTRODUCTION: Interleukin (IL)-6-type cytokines exert their effects through activation of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling cascade. The JAK/STAT pathways play an important role in rheumatoid arthritis, since JAK inhibitors have exhibited dramatic effects on rheumatoid arthritis (RA) in clinical trials. In this study, we investigated the molecular effects of a small molecule JAK inhibitor, CP690,550 on the JAK/STAT signaling pathways and examined the role of JAK kinases in rheumatoid synovitis. METHODS: Fibroblast-like synoviocytes (FLS) were isolated from RA patients and stimulated with recombinant oncostatin M (OSM). The cellular supernatants were analyzed using cytokine protein chips. IL-6 mRNA and protein expression were analyzed by real-time PCR method and ELISA, respectively. Protein phosphorylation of rheumatoid synoviocytes was assessed by Western blot using phospho-specific antibodies. RESULTS: OSM was found to be a potent inducer of IL-6 in FLS. OSM stimulation elicited rapid phosphorylation of STATs suggesting activation of the JAK/STAT pathway in FLS. CP690,550 pretreatment completely abrogated the OSM-induced production of IL-6, as well as OSM-induced JAK/STAT, and activation of mitogen-activated kinases (MAPKs) in FLS. CONCLUSIONS: These findings suggest that IL-6-type cytokines contribute to rheumatoid synovitis through activation of the JAK/STAT pathway in rheumatoid synoviocytes. Inhibition of these pro-inflammatory signaling pathways by CP690,550 could be important in the treatment of RA. Conventional immunosuppressive therapies have radically transformed patient survival in systemic lupus erythematosus (SLE), but their use is associated with considerable toxicity and a substantial proportion of patients remain refractory to treatment. A more comprehensive understanding of the complexity of SLE immunopathogenesis has evolved over the past decade and has led to the testing of several biologic agents in clinical trials. There is a clear need for new therapeutic agents that overcome these issues, and biologic agents offer exciting prospects as future SLE therapies.An array of promising new therapies are currently emerging or are under development including B-cell depletion therapies, agents targeting B-cell survival factors, blockade of T-cell co-stimulation and anti-cytokine therapies, such as monoclonal antibodies against interleukin-6 and interferon-α. OBJECTIVE: To determine the efficacy, safety, and tolerability of 3 different dosages of CP-690,550, a potent, orally active JAK inhibitor, in patients with active rheumatoid arthritis (RA) in whom methotrexate, etanercept, infliximab, or adalimumab caused an inadequate or toxic response. METHODS: Patients (n = 264) were randomized equally to receive placebo, 5 mg of CP-690,550, 15 mg of CP-690,550, or 30 mg of CP-690,550 twice daily for 6 weeks, and were followed up for an additional 6 weeks after treatment. The primary efficacy end point was the American College of Rheumatology 20% improvement criteria (ACR20) response rate at 6 weeks. RESULTS: By week 6, the ACR20 response rates were 70.5%, 81.2%, and 76.8% in the 5 mg, 15 mg, and 30 mg twice daily groups, respectively, compared with 29.2% in the placebo group (P < 0.001). Improvements in disease activity in CP-690,550-treated patients compared with placebo were seen in all treatment groups as early as week 1. ACR50 and ACR70 response rates significantly improved in all treatment groups by week 4. The most common adverse events reported were headache and nausea. The infection rate in both the 15 mg twice daily group and the 30 mg twice daily group was 30.4% (versus 26.2% in the placebo group). No opportunistic infections or deaths occurred. Increases in mean low-density lipoprotein cholesterol and high-density lipoprotein cholesterol levels, and increases in mean serum creatinine level (0.04-0.06 mg/dl) were seen in all CP-690,550 treatment arms. CONCLUSION: Our findings indicate that CP-690,550 is efficacious in the treatment of RA, resulting in rapid, statistically significant, and clinically meaningful reductions in the signs and symptoms of RA. Further studies of CP-690,550 in RA are warranted. Protein kinase inhibitors represent a novel and promising approach to the treatment of rheumatoid arthritis (RA). By targeting intracellular signaling pathways of cytokine-mediated reactions, these substances are able to interfere with critical immune processes that underly the pathology of RA. With tofacitinib, the first Janus kinase (JAK) inhibitor has been approved in the USA, as well as in Switzerland and other countries. Several other substances are currently undergoing phase II or phase III trials.A crucial question that will shape the future of these new drugs is whether they are safe and in particular, whether they are safer than biological therapies. This article provides an overview on current data concerning the efficacy and safety of the most promising substances and discusses the potential future role of intracellular kinase inhibitors. There is a critical need for safer and more convenient treatments for organ transplant rejection and autoimmune disorders such as rheumatoid arthritis. Janus tyrosine kinases (JAK1, JAK3) are expressed in lymphoid cells and are involved in the signaling of multiple cytokines important for various T cell functions. Blockade of the JAK1/JAK3-STAT pathway with a small molecule was anticipated to provide therapeutic immunosuppression/immunomodulation. The Pfizer compound library was screened against the catalytic domain of JAK3 resulting in the identification of a pyrrolopyrimidine-based series of inhibitors represented by CP-352,664 (2a). Synthetic analogues of 2a were screened against the JAK enzymes and evaluated in an IL-2 induced T cell blast proliferation assay. Select compounds were evaluated in rodent efficacy models of allograft rejection and destructive inflammatory arthritis. Optimization within this chemical series led to identification of CP-690,550 1, a potential first-in-class JAK inhibitor for treatment of autoimmune diseases and organ transplant rejection. Rheumatoid arthritis (RA) is a representative autoimmune disease characterized by chronic and destructive inflammatory synovitis. The multiple cytokines play pivotal roles in RA pathogenesis by inducing intracellular signaling, and members of the Janus kinase (JAK) family are essential for such signal transduction. An orally available JAK3 inhibitor, tofacitinib, has been applied for RA, with satisfactory effects and acceptable safety in multiple clinical examinations. From phase 2 dose-finding studies, tofacitinib 5 mg and 10 mg twice a day appear suitable for further evaluation. Subsequently, multiple phase 3 studies were carried out, and tofacitinib with or without methotrexate (MTX) is efficacious and has a manageable safety profile in active RA patients who are MTX naïve or show inadequate response to methotrexate (MTX-IR), disease-modifying antirheumatic drugs (DMARD)-IR, or tumor necrosis factor (TNF)-inhibitor-IR. The common adverse events were infections, such as nasopharyngitis; increases in cholesterol, transaminase, and creatinine; and decreases in neutrophil counts. Although the mode of action of tofacitinib remains unclear, we clarified that the inhibitory effects of tofacitinib could be mediated through suppression of interleukin (IL)-17 and interferon (IFN)-γ production and proliferation of CD4(+) T cells in the inflamed synovium. Taken together, an orally available kinase inhibitor tofacitinib targeting JAK-mediated signals would be expected to be a new option for RA treatment. Janus kinases have proved to be essential for many immunological processes but there is growing evidence that they also play a critical role in pathogenesis of many diseases including inflammatory diseases and cancer where they promote multiple steps of tumorigenesis. Several companies are in late stage clinical programs for the development of JAK kinase inhibitors and the first small molecule JAK inhibitor, Jakafi® (ruxolitinib) has been just approved for treatment of myeloproliferative neoplasms. Several other molecules are on the rise to treat arthritis, psoriasis and multiple types of cancer. This commentary will provide a review of the JAK kinase field as it pertains to small molecule inhibition for the treatment of cancer and autoimmune diseases with an emphasis on JAK2. The use of experimental and clinical inhibitors of JAK will be discussed for solid tumor and hematological malignancies, lupus, arthritis, colitis, neurological disorders, pain, diabetes and cardiovascular disease. In addition, it will review current paradigms in the field and treatment programs which could be complemented by small molecule inhibitors of Janus kinase. OBJECTIVES: To determine the efficacy of CP-690,550 in improving pain, function and health status in patients with moderate to severe active rheumatoid arthritis (RA) and an inadequate response to methotrexate or a tumour necrosis factor alpha inhibitor. METHODS: Patients were randomised equally to placebo, CP-690,550 5, 15 or 30 mg twice daily for 6 weeks, with 6 weeks' follow-up. The patient's assessment of arthritis pain (pain), patient's assessment of disease activity, Health Assessment Questionnaire-Disability Index (HAQ-DI) and Short Form-36 (SF-36) were recorded. RESULTS: At week 6, significantly more patients in the CP-690,550 5, 15 and 30 mg twice-daily groups experienced a 50% improvement in pain compared with placebo (44%, 66%, 78% and 14%, respectively), clinically meaningful reductions in HAQ-DI (> or =0.3 units) (57%, 75%, 76% and 36%, respectively) and clinically meaningful improvements in SF-36 domains and physical and mental components. CONCLUSIONS: CP-690,550 was efficacious in improving the pain, function and health status of patients with RA, from week 1 to week 6. OBJECTIVE: To review the pharmacology, pharmacokinetics, efficacy and safety, dosage administration, and adverse effects of tofacitinib for rheumatoid arthritis (RA) treatment. DATA SOURCES: Primary sources of information were obtained from clinical studies, which were identified through PubMed (1966 to June 2013) and International Pharmaceutical Abstracts (1970 to March 2013) using terms: tofacitinib, tasocitinib, CP-690550, and CP-690,550. Information was used from tofacitinib package insert, guidelines, and published abstracts from the American College of Rheumatology (ACR) and the European League Against Rheumatism. STUDY SELECTION AND DATA EXTRACTION: Data search was limited to include publications in English language and from human subjects. DATA SYNTHESIS: Tofacitinib is the first oral Janus kinase inhibitor indicated for treatment of moderate to severe RA. Tofacitinib demonstrated efficacy and safety comparable to other disease-modifying antirheumatic drugs (DMARDs). Tofacitinib was efficacious in RA patients, indicated by achievements of ACR20, ACR50, and ACR70 criteria. Similar improvements were observed in patients who met remission criteria based on the Disease Activity Scores 28 criteria and quality of life as measured by the Health Assessment Questionnaire-Disability Index (HAQ-DI). Tofacitinib was associated with infections and malignancies; and elevations in serum creatinine and lipids were observed. Drug interactions with inducers and inhibitors of the cytochrome P-450 3A4 and 2C9 isoenzymes were reported. CONCLUSIONS: Tofacitinib is an oral treatment option for RA patients who have inadequate response or intolerance to methotrexate. Postmarket surveillance will provide further insight to tofacitinib's role in RA therapy, especially in patients who may require different types of combination therapy with DMARDS. OBJECTIVE: To summarise the adverse events (AE) reported in patients with rheumatoid arthritis (RA) treated with protein kinase inhibitors (PKi), and identify family and molecule-related AEs. METHODS: Systematic review of the PKi used in clinical trials (CTs) in RA. Medline, Embase, Cochrane Library, Web of Knowledge, and international abstracts of congress were reviewed, (up to 31 October 2012). Search was limited to interventional studies of PKi used in CTs in RA, written in English, and reporting frequencies of AE. Diseases with similar comorbidity burden also were included. Frequency of AE, serious AE (SAE), death and discontinuation due to AEs (DCAE) were recorded. Risk of bias was assessed. Meta-analysis was carried using pooled relative risk (RR) with 95% CI as effect measure. RESULTS: The search produced 4410 hits. Forty-one articles reporting data on 21 PKi of the Janus kinase (JAK), SYK, p38 and cKit families were selected for detailed analysis. In patients treated with p38 inhibitors, RR for dizziness was 2.36 (1.20 to 4.63), and in patients treated with c-Kit inhibitors, RR for oedema was 3.43 (1.58 to 7.42). In patients treated with the JAK inhibitor tofacitinib, RR for hypercholesterolaemia was 1.70 (1.10 to 2.63) that was dose related. In patients treated with the Syk inhibitor fostamatinib, pooled RR for hypertransaminasaemia, hypertension, diarrhoea and neutropenia were 2.93 (1.02 to 8.43), 2.80 (1.58 to 5.99), 5.20 (3.19 to 8.49) and 9.24 (2.22 to 38.42), respectively. Serious infections and malignancies were not significantly more frequent in PKi-treated patients than in comparator groups. CONCLUSIONS: Event rates of serious infections and malignancies with PKi are not different from biologics. In addition, PKi have a unique safety profile related to target and off-target inhibition of kinases, at times dose related. OBJECTIVE: Tofacitinib, which is a Janus kinase (JAK) inhibitor, has shown clinical effects in the treatment of rheumatoid arthritis. JAKs are important kinases in lymphocyte differentiation; however, their function in dendritic cells (DCs) is unknown. In this study, the function of JAKs in DCs was investigated with tofacitinib. METHODS: The effects of tofacitinib on the maturation of human monocyte-derived DCs induced by lipopolysaccharide (LPS) stimulation were investigated. In addition, its effects on T cell stimulatory capability was investigated by coculturing with naïve CD45RA-positive T cells. RESULTS: Tofacitinib decreased expression of CD80/CD86 in a concentration-dependent manner in LPS-stimulated DCs; however, it did not affect HLA-DR expression. Tofacitinib suppressed tumour necrosis factor, interleukin (IL)-6 and IL-1β production without affecting transforming growth factor (TGF)-β and IL-10 production. Meanwhile, CD80/CD86 expression in DCs was enhanced by type I interferon (IFN) stimulation, and the LPS-induced CD80/CD86 expression was inhibited by an antibody to type I IFN receptor. Furthermore, tofacitinib suppressed production of type I IFN and activation of interferon regulatory factor (IRF)-7, which is a transcription factor involved in CD80/CD86 and type I IFN expression. Tofacitinib also decreased the T cell stimulatory capability of DCs and increased expression of indoleamine 2,3-dioxygenase (IDO)-1 and IDO-2. CONCLUSIONS: Tofacitinib, a JAK1/JAK3 inhibitor, affected the activities of human DCs. It decreased CD80/CD86 expression and T cell stimulatory capability through suppression of type I IFN signalling. These results suggest a novel mode of action for tofacitinib and a pivotal role for JAKs in the differentiation of DCs. OBJECTIVE: To compare the efficacy, safety, and tolerability of 5 doses of oral tofacitinib (CP-690,550) or adalimumab monotherapy with placebo for the treatment of active rheumatoid arthritis (RA) in patients with an inadequate response to disease-modifying antirheumatic drugs. METHODS: In this 24-week, double-blind, phase IIb study, patients with RA (n = 384) were randomized to receive placebo, tofacitinib at 1, 3, 5, 10, or 15 mg administered orally twice a day, or adalimumab at 40 mg injected subcutaneously every 2 weeks (total of 6 injections) followed by oral tofacitinib at 5 mg twice a day for 12 weeks. The primary end point was the responder rate according to the American College of Rheumatology 20% improvement criteria (ACR20) at week 12. RESULTS: Treatment with tofacitinib at a dose of ≥3 mg twice a day resulted in a rapid response with significant efficacy when compared to placebo, as indicated by the primary end point (ACR20 response at week 12), achieved in 39.2% (3 mg; P ≤ 0.05), 59.2% (5 mg; P < 0.0001), 70.5% (10 mg; P < 0.0001), and 71.9% (15 mg; P < 0.0001) in the tofacitinib group and 35.9% of patients in the adalimumab group (P = 0.105), compared with 22.0% of patients receiving placebo. Improvements were sustained at week 24, according to the ACR20, ACR50, and ACR70 response rates as well as classifications of remission according to the 3-variable Disease Activity Score in 28 joints (DAS28) using C-reactive protein and the 4-variable DAS28 using the erythrocyte sedimentation rate. The most common treatment-emergent adverse events (AEs) in patients across all tofacitinib treatment arms (n = 272) were urinary tract infection (7.7%), diarrhea (4.8%), headache (4.8%), and bronchitis (4.8%). CONCLUSION: Tofacitinib monotherapy at ≥3 mg twice a day was efficacious in the treatment of patients with active RA over 24 weeks and demonstrated a manageable safety profile. AIMS: To investigate the effects of methotrexate (MTX) on the pharmacokinetics (PK) of CP-690,550, a novel Janus kinase (JAK) inhibitor in development as a therapy for rheumatoid arthritis (RA), to determine the effects of multiple doses of CP-690,550 on the PK of MTX, and to evaluate the short-term safety and tolerability of co-administration of CP-690,550 and MTX. METHODS: This was a fixed-dose drug-drug interaction study. Twelve patients diagnosed with RA for at least 6 months were enrolled in a Phase I, open-label study of the PK of multiple doses of CP-690,550 (30 mg b.i.d.) and single doses of MTX (15-25 mg per week). RESULTS: All patients completed the study and were evaluated for PK and safety. CP-690,550 exposure was not affected by co-administration with MTX; AUC(12) ratio (CP-690,550 + MTX/CP-690,550) was 103.06% [90% confidence interval (CI) 99.00, 107.29]. MTX exposure decreased by 10%; AUC(12) ratio (CP-690,550 + MTX/MTX) was 89.53% (90% CI 77.38, 103.57), which was not considered clinically significant. Co-administration of CP-690,550 and MTX was safe and well tolerated. There were no serious adverse events or withdrawals from the study and there was no trend in the incidence or severity of adverse events across treatments. CONCLUSIONS: Co-administration of CP-690,550 and MTX was safe and well tolerated. There was no clinically significant effect on the PK profile of either drug. Therefore, dose adjustments should not be required when co-administering CP-690,550 and MTX. In this review, we describe the current knowledge of the biology of the JAKs. The JAK family comprises the four nonreceptor tyrosine kinases JAK1, JAK2, JAK3, and Tyk2, all key players in the signal transduction from cytokine receptors to transcription factor activation. We also review the progresses made towards the optimization of JAK inhibitors and the importance of their selectivity profile. Indeed, the full array of many medicinal chemistry enabling tools (HTS, X-ray crystallography, scaffold morphing, etc.) has been deployed to successfully design molecules that discriminate among JAK family and other kinases. While the first JAK inhibitor was launched in 2011, this review also summarizes the status of several other small-molecule JAK inhibitors currently in development to treat arthritis, psoriasis, organ rejection, and multiple cancer types. Treatment of rheumatoid arthritis (RA) has developed dramatically by the appearance of biologics. However the development of a new anti-rheumatic drug is necessary because of its issue on route of administration and expense. Recently, inhibitors targeting tyrosine kinase known as Janus kinase (Jak) has shown prominent effect on RA. Jak family is comprised by Jak1, Jak2, Jak3 and Tyk2 which is necessary for signal transduction for inflammatory cytokines. INCB18424 targeting Jak1/2 and CP690,550 targeting Jak3 has been developed and is now on phase II clinical study for RA. Results from those clinical studies have proven that these inhibitors can be effective as biologics with few side effects. However, it has been reported that inhibitors are less specific than it has been expect and that non-specificity can be important for its effect. Therefore, we think that the mechanism of inhibitors cannot be explained by its inhibition of a single kinase. Herein, we describe IL-10 overproduction by Jak3 and Stat6 deficient dendritic cell. We speculate that this is one possible mechanism of action for CP690,550 although as for its non-specificity we need further investigation to predict not only its effect but also its side effect in a long term administration. CP-690,550 is an orally active and selective inhibitor of the janus kinase (JAK) molecules. The molecular pathways through which the JAK moieties function are described along with the clinical mechanisms associated with their inhibition. Animal models of JAK inhibition are reviewed as a background for the possible inhibition of JAK in humans. The pharmacokinetics of CP-690,550 in humans is described, and the Phase IIA and IIB trials are reviewed in some detail. These trials were dose-ranging and showed a general dose response with relatively robust American College of Rheumatology 20 (ACR20) responses. A proof-of-concept 6-week trial in which CP-690,550 was given as monotherapy was associated with highly efficacious responses at the mid and higher twice-daily dose ranges employed. A subsequent 24 week dose-ranging trial in which CP-690,550 was administered in combination with methotrexate showed ACR20 responses, which were also statistically significant versus placebo interventions. CP-690,550 treatment was associated with side effects, which included headache and nausea. Infections were more common versus placebo as were elevations in transaminase enzymes when administered in combination with methotrexate, and increases in low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol. Decreases in haemoglobin and white blood cell (WBC) counts were also observed along with small increases in serum creatinine. Occasional significant decreases of haemoglobin (>2 g dl(-1)) were observed, although decreases of WBC to less than 1000 per mm(3) were not seen. Plans for long-term follow-up of the described trials are described along with the features of five presently ongoing Phase III trials of the CP-690,550 janus kinase (JAK) inhibitor. Future directions include completion and publication of these trials along with study of JAK inhibition for other indications. Multiple cytokines play a pivotal role in the pathogenesis of rheumatoid arthritis (RA). The appropriate intracellular signalling pathways must be activated via cytokine receptors on the cell surface, and the tyrosine kinases transduce the first 'outside to in' signals to be phosphorylated after receptor binding to its ligand. Among them, members of the Janus kinase (JAK) family are essential for the signalling pathways of various cytokines and are implicated in the pathogenesis of RA. The in vitro, ex vivo and in vivo effects of a JAK inhibitor CP-690,550 (tofacitinib) for the treatment of RA are reported. In vitro experiments indicated that the effects of tofacitinib were mediated through suppression of interleukin 17 (IL-17) and interferon γ production and proliferation of CD4 T cells, presumably Th1 and Th17. A treatment study was conducted in the severe combined immunodeficiency (SCID)-HuRAg mice, an RA animal model using SCID mice implanted with synovium and cartilage from patients. Tofacitinib reduced serum levels of human IL-6 and IL-8 in the mice and also reduced synovial inflammation and invasion into the implanted cartilage. A phase 2 double-blind study using tofacitinib was carried out in Japanese patients with active RA and inadequate response to methotrexate (MTX). A total of 140 patients were randomised to tofacitinib 1, 3, 5, 10 mg or placebo twice daily and the American College of Rheumatology 20% improvement criteria (ACR20) response rate at week 12, a primary end point, was significant for all tofacitinib treatment groups. Thus, an orally available tofacitinib in combination with MTX was efficacious and had a manageable safety profile. Tofacitinib at 5 and 10 mg twice a day appears suitable for further evaluation to optimise the treatment of RA.

Which is the mechanism used for synthesis of a highly functional N-truncated dystrophin isoform that attenuates dystrophinopathy?

Translation from a DMD exon 5 IRES results in a functional dystrophin isoform that attenuates dystrophinopathy in humans and mice

[25108525]

Author information: (1)1] The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA. [2]. (2)Section of Microbiology and Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy. (3)Department of Proteomics and Nanobiotechnology, School of Biotechnology, KTH Royal Institute of Technology, Stockholm, Sweden. (4)Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, USA. (5)The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA. (6)1] Center for RNA Biology, The Ohio State University, Columbus, Ohio, USA. [2] Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio, USA. (7)Department of Neuroscience, University of Messina and Centro Clinico Nemo Sud, Messina, Italy. (8)Bambino Gesù Children's Hospital, Rome, Italy. (9)Centre for Comparative Genomics, Murdoch University, Perth, Western Australia, Australia. (10)1] The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA. [2] Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA. (11)Division of Biomedical Informatics, Department of Computer Science, University of Kentucky Lexington, Kentucky, USA. (12)Department of Human Genetics, The University of Utah School of Medicine, Salt Lake City, Utah, USA. (13)1] The Center for Gene Therapy, Nationwide Children's Hospital, The Ohio State University, Columbus, Ohio, USA. [2] Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA. [3] Department of Neurology, The Ohio State University, Columbus, Ohio, USA.

Which are the newly identified DNA nucleases that can be used to treat thalassemia?

Thalassemia is genetic diseases of the blood caused by mutations in the globin gene. Main goal for thalassemia treatment is to develop homologous recombination based gene therapy in order to cure these diseases. Zinc finger nucleases (ZFNs) and TAL effector nucleases (TALENs) are proper targets for the human globin gene. Genome editing using engineered nucleases such as ZFNs and TALENs has become a powerful technology for reverse genetics.

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β-Thalassemia (β-Thal) is a group of life-threatening blood disorders caused by either point mutations or deletions of nucleotides in β-globin gene (HBB). It is estimated that 4.5% of the population in the world carry β-Thal mutants (1), posing a persistent threat to public health. The generation of patient-specific induced pluripotent stem cells (iPSCs) and subsequent correction of the disease-causing mutations offer an ideal therapeutic solution to this problem. However, homologous recombination-based gene correction in human iPSCs remains largely inefficient. Here, we describe a robust process combining efficient generation of integration-free β-Thal iPSCs from the cells of patients and transcription activator-like effector nuclease (TALEN)-based universal correction of HBB mutations in situ. We generated integration-free and gene-corrected iPSC lines from two patients carrying different types of homozygous mutations and showed that these iPSCs are pluripotent and have normal karyotype. We showed that the correction process did not generate TALEN-induced off targeting mutations by sequencing. More importantly, the gene-corrected β-Thal iPS cell lines from each patient can be induced to differentiate into hematopoietic progenitor cells and then further to erythroblasts expressing normal β-globin. Our studies provide an efficient and universal strategy to correct different types of β-globin mutations in β-Thal iPSCs for disease modeling and applications. Author information: (1)is at the Genome Center and the Department of Biochemistry and Molecular Medicine , University of California, Davis , United States [email protected]. RNA-guided endonucleases (RGENs), derived from the prokaryotic adaptive immune system known as CRISPR/Cas, enable targeted genome engineering in cells and organisms. RGENs are ribonucleoproteins that consist of guide RNA and Cas9, a protein component originated from Streptococcus pyogenes. These enzymes cleave chromosomal DNA, whose sequence is complementary, to guide RNA in a targeted manner, producing site-specific DNA double-strand breaks (DSBs), the repair of which gives rise to targeted genome modifications. Despite broad interest in RGEN-mediated genome editing, these nucleases are limited by off-target mutations and unwanted chromosomal translocations associated with off-target DNA cleavages. Here, we show that off-target effects of RGENs can be reduced below the detection limits of deep sequencing by choosing unique target sequences in the genome and modifying both guide RNA and Cas9. We found that both the composition and structure of guide RNA can affect RGEN activities in cells to reduce off-target effects. RGENs efficiently discriminated on-target sites from off-target sites that differ by two bases. Furthermore, exome sequencing analysis showed that no off-target mutations were induced by two RGENs in four clonal populations of mutant cells. In addition, paired Cas9 nickases, composed of D10A Cas9 and guide RNA, which generate two single-strand breaks (SSBs) or nicks on different DNA strands, were highly specific in human cells, avoiding off-target mutations without sacrificing genome-editing efficiency. Interestingly, paired nickases induced chromosomal deletions in a targeted manner without causing unwanted translocations. Our results highlight the importance of choosing unique target sequences and optimizing guide RNA and Cas9 to avoid or reduce RGEN-induced off-target mutations. Induced pluripotent stem (iPS) cell technology holds vast promises for a cure to the hemoglobinopathies. Constructs and methods to safely insert therapeutic genes to correct the genetic defect need to be developed. Site-specific insertion is a very attractive method for gene therapy because the risks of insertional mutagenesis are eliminated provided that a "safe harbor" is identified, and because a single set of validated constructs can be used to correct a large variety of mutations simplifying eventual clinical use. We report here the correction of α-thalassemia major hydrops fetalis in transgene-free iPS cells using zinc finger-mediated insertion of a globin transgene in the AAVS1 site on human chromosome 19. Homozygous insertion of the best of the 4 constructs tested led to complete correction of globin chain imbalance in erythroid cells differentiated from the corrected iPS cells. Tal-effector nucleases (TALENs) are engineered proteins that can stimulate precise genome editing through specific DNA double-strand breaks. Sickle cell disease and β-thalassemia are common genetic disorders caused by mutations in β-globin, and we engineered a pair of highly active TALENs that induce modification of 54% of human β-globin alleles near the site of the sickle mutation. These TALENS stimulate targeted integration of therapeutic, full-length beta-globin cDNA to the endogenous β-globin locus in 19% of cells prior to selection as quantified by single molecule real-time sequencing. We also developed highly active TALENs to human γ-globin, a pharmacologic target in sickle cell disease therapy. Using the β-globin and γ-globin TALENs, we generated cell lines that express GFP under the control of the endogenous β-globin promoter and tdTomato under the control of the endogenous γ-globin promoter. With these fluorescent reporter cell lines, we screened a library of small molecule compounds for their differential effect on the transcriptional activity of the endogenous β- and γ-globin genes and identified several that preferentially upregulate γ-globin expression. Transcription activator-like effectors (TALEs), first identified in Xanthomonas bacteria, are naturally occurring or artificially designed proteins that modulate gene transcription. These proteins recognize and bind DNA sequences based on a variable numbers of tandem repeats. Each repeat is comprised of a set of ∼ 34 conserved amino acids; within this conserved domain, there are usually two amino acids that distinguish one TALE from another. Interestingly, TALEs have revealed a simple cipher for the one-to-one recognition of proteins for DNA bases. Synthetic TALEs have been used to successfully target genes in a variety of species, including humans. Depending on the type of functional domain that is fused to the TALE of interest, these proteins can have diverse biological effects. For example, after binding DNA, TALEs fused to transcriptional activation domains can function as robust transcription factors (TALE-TFs), while fused to restriction endonucleases (TALENs) can cut DNA. Targeted genome editing, in theory, is capable of modifying any endogenous gene sequence of interest; this can be performed in cells or organisms, and may be applied to clinical gene-based therapies in the future. With current technologies, highly accurate, specific, and reliable gene editing cannot be achieved. Thus, recognition and binding mechanisms governing TALE biology are currently hot research areas. In this review, we summarize the major advances in TALE technology over the past several years with a focus on the interaction between TALEs and DNA, TALE design and construction, potential applications for this technology, and unique characteristics that make TALEs superior to zinc finger endonucleases. The Cas9 endonuclease is the central component of the Type II CRISPR/Cas system, a prokaryotic adaptive restriction system against invading nucleic acids, such as those originating from bacteriophages and plasmids. Recently, this RNA-directed DNA endonuclease has been harnessed to target DNA sequences of interest. Here, we review the development of Cas9 as an important tool to not only edit the genomes of a number of different prokaryotic and eukaryotic species, but also as an efficient system for site-specific transcriptional repression or activation. Additionally, a specific Cas9 protein has been observed to target an RNA substrate, suggesting that Cas9 may have the ability to be programmed to target RNA as well. Cas proteins from other CRISPR/Cas subtypes may also be exploited in this regard. Thus, CRISPR/Cas systems represent an effective and versatile biotechnological tool, which will have significant impact on future advancements in genome engineering. Genome editing using engineered nucleases such as transcription activator-like effector nucleases (TALENs) has become a powerful technology for reverse genetics. In this study, we have described efficient detection methods for TALEN-induced mutations at endogenous loci and presented guidelines of TALEN design for efficient targeted mutagenesis in medaka, Oryzias latipes. We performed a heteroduplex mobility assay (HMA) using an automated microchip electrophoresis system, which is a simple and high-throughput method for evaluation of in vivo activity of TALENs and for genotyping mutant fish of F1 or later generations. We found that a specific pattern of mutations is dominant for TALENs harboring several base pairs of homologous sequences in target sequence. Furthermore, we found that a 5' T, upstream of each TALEN-binding sequence, is not essential for genomic DNA cleavage. Our findings provide information that expands the potential of TALENs and other engineered nucleases as tools for targeted genome editing in a wide range of organisms, including medaka. DNA mismatch repair (MMR) greatly contributes to genome integrity via the correction of mismatched bases that are mainly generated by replication errors. Postreplicative MMR excises a relatively long tract of error-containing single-stranded DNA. MutL is a widely conserved nicking endonuclease that directs the excision reaction to the error-containing strand of the duplex by specifically nicking the daughter strand. Because MutL apparently exhibits nonspecific nicking endonuclease activity in vitro, the regulatory mechanism of MutL has been argued. Recent studies suggest ATP-dependent conformational and functional changes of MutL, indicating that the regulatory mechanism involves the ATP binding and hydrolysis cycle. In this study, we investigated the effect of ATP binding on the structure of MutL. First, a cross-linking experiment confirmed that the N-terminal ATPase domain physically interacts with the C-terminal endonuclease domain. Next, hydrogen/deuterium exchange mass spectrometry clarified that the binding of ATP to the N-terminal domain induces local structural changes at the catalytic sites of MutL C-terminal domain. Finally, on the basis of the results of the hydrogen/deuterium exchange experiment, we successfully identified novel regions essential for the endonuclease activity of MutL. The results clearly show that ATP modulates the nicking endonuclease activity of MutL via structural rearrangements of the catalytic site. In addition, several Lynch syndrome-related mutations in human MutL homolog are located in the position corresponding to the newly identified catalytic region. Our data contribute toward understanding the relationship between mutations in MutL homolog and human disease. Base excision repair (BER) is a frontline repair system that is responsible for maintaining genome integrity and thus preventing premature aging, cancer and many other human diseases by repairing thousands of DNA lesions and strand breaks continuously caused by endogenous and exogenous mutagens. This fundamental and essential function of BER not only necessitates tight control of the continuous availability of basic components for fast and accurate repair, but also requires temporal and spatial coordination of BER and cell cycle progression to prevent replication of damaged DNA. The major goal of this review is to critically examine controversial and newly emerging questions about mammalian BER pathways, mechanisms regulating BER capacity, BER responses to DNA damage and their links to checkpoint control of DNA replication. In this study, we used zinc finger nuclease-mediated knockout of the aryl hydrocarbon receptor (AHR) or AHR nuclear translocator (ARNT) in MCF7 and AHR knockout in MDA-MB-231 human breast cancer cells to investigate cross talk among AHR, ARNT, and estrogen receptor α (ERα). Knockout of AHR or ARNT prevented the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-dependent induction of all AHR target genes examined. Knockout of AHR or ARNT also significantly reduced basal cytochrome P4501B1 (CYP1B1) expression levels, which were restored with overexpression of either protein but not with a DNA binding-deficient AHR mutant. Basal and TCDD-, 17β-estradiol (E2)-, or TCDD + E2-dependent recruitment of AHR, ARNT, ERα, NCoA3, and RNA polymerase II to CYP1B1 as well as CYP1B1 mRNA levels were abolished in MCF7-AHR((ko)) and MDA-MB-231 AHR(ko) cells. However, reduced but significant E2-dependent recruitment of ERα, NCoA3, and RNA polymerase II to CYP1B1 and weak increases in CYP1B1 mRNA levels were observed in MCF7 ARNT((ko)) cells. Interestingly, E2-dependent increases in trefoil factor 1, but not growth regulation by estrogen in breast cancer 1 (GREB1) mRNA levels, were dependent on ARNT expression. Moreover, the TCDD-dependent increases in the proteolytic degradation of ERα were prevented by the loss of AHR or ARNT. Our data show that AHR and ARNT play critical roles in the basal, TCDD, and E2-induced regulation of CYP1B1 but also reveal distinct roles for both proteins in ERα transactivation. Over the past 5 years there has been a major transformation in our ability to precisely manipulate the genomes of animals. Efficiencies of introducing precise genetic alterations in large animal genomes have improved 100000-fold due to a succession of site-specific nucleases that introduce double-strand DNA breaks with a specificity of 10(-9). Herein we describe our applications of site-specific nucleases, especially transcription activator-like effector nucleases, to engineer specific alterations in the genomes of pigs and cows. We can introduce variable changes mediated by non-homologous end joining of DNA breaks to inactive genes. Alternatively, using homology-directed repair, we have introduced specific changes that support either precise alterations in a gene's encoded polypeptide, elimination of the gene or replacement by another unrelated DNA sequence. Depending on the gene and the mutation, we can achieve 10%-50% effective rates of precise mutations. Applications of the new precision genetics are extensive. Livestock now can be engineered with selected phenotypes that will augment their value and adaption to variable ecosystems. In addition, animals can be engineered to specifically mimic human diseases and disorders, which will accelerate the production of reliable drugs and devices. Moreover, animals can be engineered to become better providers of biomaterials used in the medical treatment of diseases and disorders. 1. 1.

Does ziconotide bind to N-type calcium channels?

Yes, ziconotide/omega-conotoxin MVIIA blocks N-type calcium channels.

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Ziconotide has been introduced as a new nonopioid treatment for chronic pain. Structurally, it is a peptide, the synthetic analog of the omega-conotoxin, derived from the marine snail, Conus magus. N-type voltage-sensitive calcium channels play a role in the transmission of nociceptive stimuli and also are involved in the release of neurotransmitters important in pain transmission. Ziconotide's therapeutic benefit derives from its potent and selective blockade of neuronal-type voltage-sensitive calcium channels. Blockade of the channels results in suppression of abnormal ectopic discharges from the injury site or the dorsal root ganglia, possibly resulting in decreased neuroplasticity, and decreased synaptic transmission that leads to the generation of chronic pain syndromes. The advantage of ziconotide is that tolerance does not occur, while disadvantages associated with ziconotide are the need for intrathecal administration and significant neurotoxicites associated with its use. When tested in clinical trials, ziconotide has been shown to have synergistic or additive value to the effect of morphine. Ziconotide, formerly known also as SNX- 111, represents a new class of agents, the N-type calcium channel blockers. These may represent another option for patients with refractory pain and refractory pain syndromes. BACKGROUND: The authors investigated the role of different voltage-sensitive calcium channels expressed at presynaptic afferent terminals in substance P release and on nociceptive behavior evoked by intraplantar formalin by examining the effects of intrathecally delivered N- (ziconotide), T- (mibefradil), and L-type voltage-sensitive calcium channel blockers (diltiazem and verapamil). METHODS: Rats received intrathecal pretreatment with saline or doses of morphine, ziconotide, mibefradil, diltiazem, or verapamil. The effect of these injections upon flinching evoked by intraplantar formalin (5%, 50 μl) was quantified. To assess substance P release, the incidence of neurokinin-1 receptor internalization in the ipsilateral and contralateral lamina I was determined in immunofluorescent-stained tissues. RESULTS: Intrathecal morphine (20 μg), ziconotide (0.3, 0.6, and 1 μg), mibefradil (100 μg, but not 50 μg), diltiazem (500 μg, but not 300 μg), and verapamil (200 μg, but not 50 and 100 μg) reduced paw flinching in phase 2 compared with vehicle control (P < 0.05), with no effect on phase 1. Ziconotide (0.3, 0.6, and 1 μg) and morphine (20 μg) significantly inhibited neurokinin-1 receptor internalization (P < 0.05), but mibefradil, diltiazem, and verapamil at the highest doses had no effect. CONCLUSION: These results emphasize the role in vivo of N-type but not T- and L-type voltage-sensitive calcium channel blockers in mediating the stimulus-evoked substance P release from small primary afferents and suggest that T- and L-type voltage-sensitive calcium channel blockers exert antihyperalgesic effects by an action on other populations of afferents or mechanisms involving postsynaptic excitability. Ca(V)2.2 (N-type) calcium channels are key regulators of neurotransmission. Evidence from knockout animals and localization studies suggest that Ca(V)2.2 channels play a critical role in nociceptive transmission. Additionally, ziconotide, a selective peptide inhibitor of Ca(V)2.2 channels, is clinically used to treat refractory pain. However, the use of ziconotide is limited by its low therapeutic index, which is believed, at least in part, to be a consequence of ziconotide inhibiting Ca(V)2.2 channels regardless of the channel state. Subsequent efforts have focused on the discovery of state-dependent inhibitors that preferentially bind to the inactivated state of Ca(V)2.2 channels in order to achieve an improved safety profile relative to ziconotide. Much less attention has been paid to understanding the binding kinetics of these state-dependent inhibitors. Here, we describe a novel electrophysiology-based assay on an automated patch platform designed to differentiate Ca(V)2.2 inhibitors based on their combined state dependence and kinetics. More specifically, this assay assesses inactivated state block, closed state block, and monitors the kinetics of recovery from block when channels move between states. Additionally, a use-dependent assay is described that uses a train of depolarizing pulses to drive channels to a similar level of inactivation for comparison. This use-dependent protocol also provides information on the kinetics of block development. Data are provided to show how these assays can be utilized to screen for kinetic diversity within and across chemical classes. The N-type calcium channel is a member of the voltage-sensitive calcium channel family and plays a major role in the regulation of neurotransmitter release in the central and peripheral nervous systems. Inhibition of the N-type calcium channel by intrathecal administration of the channel-specific blocker omega-conotoxin MVIIA (ziconotide) is efficacious in the treatment of severe chronic pain. While no orally active small molecules that block the N-type calcium channel are currently available, the discovery of such potentially valuable therapeutics would benefit from a reliable, high throughput assay. However, the assay of N-type calcium channel activity by measuring calcium influx using nonadherent cells in a high throughput fashion has not been achieved before, likely owing to a number of technical hurdles. For example, the measurement of calcium levels in nonadherent cells using conventional calcium indicators, such as Fluo-3 or Fluo-4, requires dyeloading the cells in suspension and subsequent removal of extracellular dye. This limits plate throughput and requires constant handling of the cells. To assay the N-type calcium channel activity using a nonadherent cell line in a high throughput manner, we investigated the application of no-wash calcium assay kits from Molecular Devices Corp. (Sunnyvale, CA): FLIPR Calcium, FLIPR Calcium Plus, and FLIPR Calcium 3. We show here that the FLIPR Calcium 3 assay kit can be used with nonadherent IMR-32 cells to measure potassium-evoked, omega-conotoxin MVIIA-reversible calcium flux with high throughput (15,000 data points/day), high quality (Z approximately 0.6), and minimal handling of the cells. Thus, this assay can be used to reliably and efficiently screen large compound libraries in the search for small molecule N-type calcium channel blockers. Ziconotide (SNX-111), a selective blocker of neuronal N-type voltage-sensitive calcium channels, is antinociceptive when it is administered intrathecally. It is currently under clinical investigation for the treatment of malignant and non-malignant pain syndromes. The present study was undertaken to compare and contrast antinociceptive properties of ziconotide, morphine and clonidine in a rat model of post-operative pain. Post-operative pain was produced by making a longitudinal incision through the skin, fascia, and muscle of the plantar aspect of the left hindpaw. This procedure produced immediate (0.5 h after surgery) and long-lasting (4-7 days post-surgery) heat hyperalgesia and mechanical allodynia in the injured hindpaw. Pain thresholds in the contralateral hindpaw were unaffected. Administered one day after incisional surgery, intrathecal ziconotide blocked established heat hyperalgesia in the injured hindpaw in a dose-dependent manner yielding an ED(50)4 h) but reversible (<24 h) blockade of established mechanical allodynia. Administered one day after surgery, intrathecal bolus injection of morphine dose-dependently blocked heat hyperalgesia in the injured hindpaw with an ED(50) of 1.6 microg (2.1 nmol) and heat nociceptive responses in the normal hindpaw with an ED(50) of 2.7 microg (3.6 nmol). The effects were immediate and short-lasting (</=1 h). Intravenous bolus injection of 3 mg/kg (1.1 micromol/kg) ziconotide, administered either before or after incisional surgery, had no effect on thermal pain thresholds measured in either the injured or normal hindpaw. In contrast, intraperitoneal injections of 2 mg/kg (2.6 micromol/kg) morphine and 2.5 mg/kg (9.4 micromol/kg) clonidine blocked heat hyperalgesia in the injured hindpaw; morphine, but not clonidine, also elevated thermal (heat) nociceptive response thresholds in the normal hindpaw. The results of this study show that intrathecal ziconotide is antinociceptive in a rat incisional model of post-operative pain and is more potent, longer acting, and more specific in its actions than intrathecal morphine. Voltage-gated sodium channels (VGSCs) are large transmembrane proteins that conduct sodium ions across the membrane and by doing so they generate signals of communication between many kinds of tissues. They are responsible for the generation and propagation of action potentials in excitable cells, in close collaboration with other channels like potassium channels. Therefore, genetic defects in sodium channel genes can cause a wide variety of diseases, generally called "channelopathies." The first insights into the mechanism of action potentials and the involvement of sodium channels originated from Hodgkin and Huxley for which they were awarded the Nobel Prize in 1963. These concepts still form the basis for understanding the function of VGSCs. When VGSCs sense a sufficient change in membrane potential, they are activated and consequently generate a massive influx of sodium ions. Immediately after, channels will start to inactivate and currents decrease. In the inactivated state, channels stay refractory for new stimuli and they must return to the closed state before being susceptible to a new depolarization. On the other hand, studies with neurotoxins like tetrodotoxin (TTX) and saxitoxin (STX) also contributed largely to our today's understanding of the structure and function of ion channels and of VGSCs specifically. Moreover, neurotoxins acting on ion channels turned out to be valuable lead compounds in the development of new drugs for the enormous range of diseases in which ion channels are involved. A recent example of a synthetic neurotoxin that made it to the market is ziconotide (Prialt(®), Elan). The original peptide, ω-MVIIA, is derived from the cone snail Conus magus and now FDA/EMA-approved for the management of severe chronic pain by blocking the N-type voltage-gated calcium channels in pain fibers. This review focuses on the current status of research on neurotoxins acting on VGSC, their contribution to further unravel the structure and function of VGSC and their potential as novel lead compounds in drug development. Accumulation of calcium following experimental traumatic brain injury (TBI) has been demonstrated to be a prominent pathophysiological component that can compromise mitochondrial functioning and threaten cell survival. The omega-conopeptide SNX-111, also known as Ziconotide, is a potent antagonist of the voltage-gated N-type calcium channel and has demonstrated significant neuroprotective effects against ischemia-induced neuronal injury. To determine whether this compound would be effective in reducing calcium accumulation associated with TBI, SNX-111 was administered intravenously to rats 1 hour following a moderate (2.2 to 2.75 atm) lateral fluid-percussion injury (or sham) at doses of 1 (n = 30), 3 (n = 31), or 5 (n = 30) mg/kg; another group received 0.9% saline solution (n = 35). Brains were processed for calcium 45 (45Ca) autoradiography at 6, 12, 24, 48, and 96 hours following insult. Optical density measurements of 20 cortical and subcortical regions were analyzed. Injured animals administered saline solution exhibited a significant increase in 45Ca uptake within 12 regions ipsilateral to the site of injury. The most prominent increases were evident throughout the ipsilateral cerebral cortex. SNX-111 reduced the injury-induced calcium accumulation within the ipsilateral cortex in a dose-response fashion when measured at 6, 12, and 48 hours after insult. These drug-induced reductions in calcium accumulation were as high as 75% in the ipsilateral cerebral cortex, and up to 50% in other ipsilateral regions (including thalamus and hippocampus). Consequently, the results suggest that posttraumatic blocking of the voltage-gated N-type calcium channel after injury reduces prolonged, trauma-induced calcium accumulation. There is strong pharmacological, biological, and genetic evidence supporting the role of N-type calcium channels (CaV2.2) in nociception. There is also human validation data from ziconotide, the CaV2.2-selective peptidyl inhibitor used clinically to treat refractory pain. Unfortunately, ziconotide utility is limited by its narrow therapeutic window and required intrathecal route of administration. A major focus has been placed on identifying state-dependent CaV2.2 inhibitors to improve safety margins. Much less attention, however, has been given to characterizing the kinetics of CaV2.2 inhibitors as a means to further differentiate compounds and maximize therapeutic potential. Here we provide a detailed characterization of the CaV2.2 inhibitor T4 in terms of its state-dependence, use-dependence, kinetics, and mechanism of inhibition. Compound T4 displayed a >20-fold difference in potency when measured under inactivating conditions (IC50=1.1 μM) as compared to closed-state conditions (IC50=25 μM). At 3 μM, T4 produced a 15-fold hyperpolarizing shift in the inactivation curve for CaV2.2 while having no effect on channel activation. To assess the kinetic properties of T4 in a more physiological manner, its inhibition kinetics were assessed at 32°C using 2 mM Ca(2+) as the charge carrier. Surprisingly, the repriming rate for CaV2.2 channels at hyperpolarized potentials was similar in both the presence and absence of T4. This was in contrast to other compounds which markedly delayed repriming. Furthermore, T4 inhibited CaV2.2 channels more potently when channel inactivation was driven through a tonic sub-threshold depolarization rather than through a use-dependent protocol, despite similar levels of inactivation. Despite their high sequence homology, the peptide neurotoxins omega-conotoxin MVIIA and MVIIC selectively block N- and P/Q-type calcium channels, respectively. To study the recognition mechanism of calcium channel subtypes, two chimeric analogs of omega-conotoxin MVIIA and MVIIC were synthesized by exchanging their N- and C-terminal halves. Binding assay for both N- and P/Q-type calcium channels showed that amino acid residues restricted to the N-terminal half are important for the recognition of N-type channels, whereas essential residues for P/Q-type channel recognition are widely spread over the whole omega-conotoxin molecule. Ziconotide is a selective, potent and reversible blocker of neuronal N-type voltage-sensitive calcium channels (VSCCs). Morphine is an agonist of mu-opioid receptors and inhibits N-type VSCC channels via a G-protein coupling mechanism. Both agents are antinociceptive when they are administered intrathecally (spinally). The present study investigated the acute and chronic (7-day) interactions of intrathecally administered ziconotide and morphine on nociception in several animal models of pain. In the acute study, intrathecal bolus injections of morphine and ziconotide alone produced dose-dependent inhibition of formalin-induced tonic flinch responses and withdrawal responses to paw pressure. The combination of ziconotide and morphine produced an additive inhibition of formalin-induced tonic flinch responses and a significant leftward shift of the morphine dose-response curve in the paw pressure test. After chronic (7-day) intrathecal infusion, ziconotide enhanced morphine analgesia in the formalin test. In contrast, chronic intrathecal morphine infusion produced tolerance to analgesia, but did not affect ziconotide antinociception. Antinociception produced by ziconotide alone was the same as that observed when the compound was co-administered with morphine to morphine-tolerant rats. In the hot-plate and tail immersion tests, chronic intrathecal infusion of morphine lead to rapid tolerance whereas ziconotide produced sustained analgesia with no loss of potency throughout the infusion period. Although ziconotide in combination with morphine produced an apparent synergistic analgesic effects during the initial phase of continuous infusion, it did not prevent morphine tolerance to analgesia. These results demonstrate that (1) acute intrathecal administrations of ziconotide and morphine produce additive or synergistic analgesic effects; (2) chronic intrathecal morphine infusion results in tolerance to analgesia but does not produce cross-tolerance to ziconotide; (3) chronic intrathecal ziconotide administration produces neither tolerance nor cross-tolerance to morphine analgesia; (4) intrathecal ziconotide does not prevent or reverse morphine tolerance. Worldwide a large number of patients suffer from severe chronic pain even after treatment with opioids following the 3-step analgesic ladder developed by the WHO. Intraspinal agents, including morphine, have been tried as a fourth step. However, approximately 20% of cases remain refractory. Ziconotide, an intrathecal analgesic with orphan drug status, is a novel alternative for the management of chronic intractable pain. Ziconotide is a synthetic peptide based on the toxin of the fish-hunting marine snail, Conus magus. It is the first therapeutic agent in a new pharmacological class of "topically" active analgesics that selectively target neuron-specific (N-type), voltage-gated calcium channels. Ziconotide produces potent analgesia by interruption of Ca-dependent primary afferent transmission of pain signals in the spinal cord. Ziconotide was significantly more effective than placebo in the treatment of chronic malignant (p < 0.001) and non-malignant pain (p < 0.001). In several clinical studies morphine dosages could be substituted by ziconotide. The drug has a lag-time for the onset and offset of analgesia and adverse effects. Initial doses should therefore be low (2.4 microg/day) and titrated slowly (increasing up to a maximum of 21.6 microg/day in increases of 2.4 microg/day no more than twice weekly). The gradual increase in dose helps to reduce the incidence and severity of adverse events which affect primarily the central nervous system (e.g. dizziness, nausea, confusion). Ziconotide maintains its analgesic efficacy over months and does not cause tolerance, dependence or respiratory depression. Following intrathecal infusion ziconotide is distributed within the cerebral spinal fluid (CSF) where its clearance (0.38 ml/min) corresponds to the rate of turnover of the CSF. Negligible amounts of ziconotide are present in the systemic circulation where it is rapidly degraded by proteolysis. In conclusion, ziconotide is a new and valuable alternative analgesic for the acute and long-term treatment of severe pain, especially in patients refractory to opioids. Spinal neurotransmission plays an important role in the perception of pain signaling. In the present study, we investigated the spinal anti-nociceptive mechanism of current standard analgesics in mouse models of tactile allodynia induced by intrathecal administration of N-methyl-D-aspartic acid (NMDA), prostaglandin E2 (PGE2), and bicuculline. NMDA-induced allodynia is induced by postsynaptic NMDA receptor activation, while PGE2-induced allodynia is triggered by the enhancement of presynaptic glutamate release via EP1 receptor activation. In contrast, bicuculline induces allodynia by the blockade of gamma-aminobutyric acid (GABA)A receptor-mediated inhibitory system. As the clinically available analgesics, pregabalin (alpha2delta-subunit calcium channel ligand), ziconotide (N-type calcium channel blocker), mexiletine (sodium channel blocker), and duloxetine (serotonin and norepinephrine reuptake inhibitors) were evaluated in these neurochemically-induced allodynia models. Pregabalin almost completely alleviated NMDA-, PGE2-, and bicuculline-induced allodynia. Despite being classified as an agent with a similar molecular target mechanism, ziconotide could only alleviate PGE2-induced allodynia, but not NMDA- or bicuculline-induced allodynia, as did mexiletine and duloxetine. These results taken together suggest that ziconotide, mexiletine, and duloxetine suppress spinal hyperactivity via the presynaptic site mechanism. In contrast, pregabalin could suppress via the downstream step during spinal hyperactivation such as postsynaptic NMDA activation or dysfunction of GABAergic control in addition to presynaptic mechanism. In conclusion, present findings provide implication that the spinal anti-nociceptive mechanistic site of pregabalin is different from that of ziconotide, mexiletine, and duloxetine, and pregabalin could have a broader anti-nociceptive mechanism other than N-type calcium channel blockade. Ziconotide is a powerful analgesic drug that has a unique mechanism of action involving potent and selective block of N-type calcium channels, which control neurotransmission at many synapses. The analgesic efficacy of ziconotide likely results from its ability to interrupt pain signaling at the level of the spinal cord. Ziconotide is a peptidic drug and has been approved for the treatment of severe chronic pain in patients only when administered by the intrathecal route. Importantly, prolonged administration of ziconotide does not lead to the development of addiction or tolerance. The current review discusses the various studies that have addressed the in vitro biochemical and electrophysiological actions of ziconotide as well as the numerous pre-clinical studies that were conducted to elucidate its antinociceptive mechanism of action in animals. In addition, this review considers the pivotal Phase 3 (and other) clinical trials that were conducted in support of ziconotide's approval for the treatment of severe chronic pain and tries to offer some insights regarding the future discovery and development of newer analgesic drugs that would act by a similar mechanism to ziconotide but which might offer improved safety, tolerability and ease of use. Selective blockers of the N-type calcium channel have proven to be effective in animal models of chronic pain. However, even though intrathecally delivered synthetic ω-conotoxin MVIIA from Conus magnus (ziconotide [Prialt®]) has been approved for the treatment of chronic pain in humans, its mode of delivery and narrow therapeutic window have limited its usefulness. Therefore, the identification of orally active, small-molecule N-type calcium channel blockers would represent a significant advancement in the treatment of chronic pain. A novel series of pyrazole-based N-type calcium channel blockers was identified by structural modification of a high-throughput screening hit and further optimized to improve potency and metabolic stability. In vivo efficacy in rat models of inflammatory and neuropathic pain was demonstrated by a representative compound from this series. Cone snails (Conidae) are marine predators with some extraordinary features. Their venom contains a hundred or more peptides that target numerous ion channels and receptors in mammals, including several that are involved in disease. omega-Conotoxins from fish hunting snails are 24-27 residue peptides with a rigid 4-loop cysteine framework that target the N-type voltage-gated calcium channel (VGCC). Two omega-conotoxins, MVIIA and CVID are currently in clinical development for chronic pain management (Ziconotide or Prialt, and AM336, respectively). In an attempt to develop small molecule equivalents of CVID, we defined the Calpha-Cbeta vectors of the residues believed to be important for binding to the N-type VGCC. Using these vectors, we undertook a virtual screening of virtual libraries approach to identify compounds that matched the pharmacophore. Cyclic pentapeptides containing residues of loop 2 of CVID, with one or more being a D-amino acid were designed and synthesised and were found to be active at the N-type VGCC (IC50 approximately 20 microM). Agreeing with the specificity profile of CVID, molecules were inactive at the P/Q-type VGCC. N-type calcium channels represent a promising target for the treatment of neuropathic pain. The selective N-type calcium channel blocker ziconotide ameliorates severe chronic pain but has a narrow therapeutic window and requires intrathecal administration. We identified tetrahydroisoquinoline derivative 1a as a novel potent N-type calcium channel blocker. However, this compound also exhibited potent inhibitory activity against hERG channels. Structural optimizations led to identification of (1S)-(1-cyclohexyl-3,4-dihydroisoquinolin-2(1H)-yl)-2-{[(1-hydroxycyclohexyl)methyl]amino}ethanone ((S)-1h), which exhibited high selectivity for hERG channels while retaining potency for N-type calcium channel inhibition. (S)-1h went on to demonstrate in vivo efficacy as an orally available N-type calcium channel blocker in a rat spinal nerve ligation model of neuropathic pain. OBJECT: Determining the efficacy of a drug used in experimental traumatic brain injury (TBI) requires the use of one or more outcome measures such as decreased mortality or fewer neurological and neuropsychological deficits. Unfortunately, outcomes in these test batteries have a fairly large variability, requiring relatively large sample sizes, and administration of the tests themselves is also very time consuming. The authors previously demonstrated that experimental TBI and human TBI induce mitochondrial dysfunction. Because mitochondrial dysfunction is easy to assess compared with neurobehavioral endpoints, it might prove useful as an outcome measure to establish therapeutic time windows and dose-response curves in preclinical drug testing. This idea was tested in a model of TBI in rats. METHODS: Animals treated with the selective N-type voltage-sensitive calcium channel blocker Ziconotide (also known as SNX-111 and CI-1009) after cortical impact displayed significant improvement in brain mitochondrial function. When a single intravenous bolus injection of 4 mg/kg Ziconotide was given at different time intervals, ranging from 15 minutes before injury to 10 hours after injury, mitochondrial function was improved at all time points, but more so between 2 and 6 hours postinjury. The authors evaluated the effects on mitochondrial function of Ziconotide at different doses by administering 0.5 to 6 mg/kg as a single bolus injection 4 hours after injury, and found 4 mg/kg to be the optimum dose. CONCLUSIONS: The authors established these time-window profiles and dose-response curves on the basis of mitochondrial outcome measures in a total of 42 rats because there were such low standard deviations in these tests. Establishing similar time-window profiles and dose-response curves by using neurobehavioral endpoints would have required using 114 rats in much more elaborate experiments. We recently reported that amino acid residues contained within a putative EF hand motif in the domain III S5-H5 region of the alpha(1B) subunit affected the relative barium:calcium permeability of N-type calcium channels (Feng, Z. P., Hamid, J., Doering, C., Jarvis, S. E., Bosey, G. M., Bourinet, E., Snutch, T. P., and Zamponi, G. W. (2001) J. Biol. Chem. 276, 5726-5730). Since this region partially overlaps with residues previously implicated in block of the channel by omega-conotoxin GVIA, we assessed the effects of mutations in the putative EF hand domain on channel block by omega-conotoxin GVIA and the structurally related omega-conotoxin MVIIA. Both of the toxins irreversibly block the activity of wild type alpha(1B) N-type channels. We find that in addition to previously identified amino acid residues, residues in positions 1326 and 1332 are important determinants of omega-conotoxin GVIA blockade. Substitution of residue Glu(1332) to arginine slows the time course of development of block. Point mutations in position Gly(1326) to either arginine, glutamic acid, or proline dramatically decrease the time constant for development of the block. Additionally, in the G1326P mutant channel activity was almost completely recovered following washout. A qualitatively similar result was obtained with omega-conotoxin MVIIA, suggesting that common molecular determinants underlie block by these two toxins. Taken together the data suggest that residue Gly(1326) may form a barrier, which controls the access of peptide toxins to their blocking site within the outer vestibule of the channel pore and also stabilizes the toxin-channel interaction. BACKGROUND AND OBJECTIVES: Voltage-sensitive calcium channel conductance is essential for the nervous system to signal a painful event. However, intrathecal administration of L-type calcium channel blockers does not provide analgesia. The present investigation was designed to assess the safety and analgesic efficacy of ziconotide, a new N-type calcium channel blocker, when administered intrathecally to patients with acute postoperative pain. METHODS: This randomized, double-blind, pilot study included patients undergoing elective total abdominal hysterectomy, radical prostatectomy, or total hip replacement. After intrathecal injection of local anesthetic and before surgical incision, a continuous intrathecal infusion of either placebo or 1 of 2 doses of ziconotide (0.7 microg/h or 7.0 microg/h) was started and continued for 48 to 72 hours postoperatively. Primary and secondary efficacy variables were the mean daily patient controlled analgesia (PCA) morphine equivalent consumption and visual analog pain intensity (VASPI) scores, respectively. RESULTS: Thirty patients received study drug; 26 were evaluable for efficacy. Mean daily PCA morphine equivalent consumption was less in patients receiving ziconotide than in placebo-treated patients, and the difference was statistically significant between 24 and 48 hours (P = .040). VASPI scores during the first 8 hours postoperatively were markedly lower in ziconotide-treated than in placebo-treated patients. In 4 of 6 patients receiving the high-dose of ziconotide (7 microg/h), adverse events, such as dizziness, blurred vision, nystagmus, and sedation contributed to study drug being discontinued after 24 hours. After ziconotide discontinuation, these symptoms resolved. CONCLUSIONS: Ziconotide showed analgesic activity, as shown by decreased PCA morphine equivalent consumption and lower VASPI scores. Because of a favorable trend of decreased morphine consumption with an acceptable side-effect profile in the low-dose ziconotide group, 0.7 microg/h may be closer to the ideal dose than 7 microg/h. Large-scale studies are required to clarify this issue. PURPOSE: Spinal cord ischemia and resulting paraplegia represent a major complication associated with surgical repair of the thoracoabdominal aorta. Although the mechanism of spinal neuronal degeneration during ischemia is unclear, it may involve excessive calcium influx via N-type voltage-sensitive calcium channels (VSCCs). The neuroprotective capacity of intrathecal (IT) administration of the selective N-type VSCC blocker ziconotide, previously shown to be potently analgesic, was studied. METHODS: In a rat aortic occlusion model, spinal cord ischemia was induced for 8, 9, or 10 minutes by occluding the descending thoracic aorta. Ziconotide was administered IT as (1) a continuous infusion of 300 or 600 ng/kg/h initiated 24 hours before ischemia and continuing an additional 24 hours or (2) a 0.3 microgram bolus injected 45 minutes before the induction of ischemia. Animals were allowed to live for 24 hours, and recovery of motor function was evaluated during this period. Spinal cords were processed using a silver impregnation technique and microtubule-associated protein type II (MAP2) immunohistochemistry. RESULTS: Continuous IT infusion of ziconotide provided significant protection against 8- and 9-minute occlusions, but not 10-minute occlusions, as indicated by recovery of motor function, degree of spinal neuronal degeneration, and loss of MAP2 immunoreactivity. Acute IT pretreatment with ziconotide provided transient protection during the initial 4 hours of reperfusion; however, this protective effect was no longer present at 24 hours. CONCLUSION: These data implicate N-type VSCC activation in spinal neuronal degeneration caused by transient spinal ischemia, because selective blockade of this channel by continuous IT infusion of ziconotide was protective against injurious intervals of spinal ischemia. Based on these findings, ziconotide may provide both neuroprotection and preemptive analgesia for aortic aneurysm surgery. N-type calcium channels located on presynaptic nerve terminals regulate neurotransmitter release, including that from the spinal terminations of primary afferent nociceptors. Accordingly, N-type calcium channel blockers may have clinical utility as analgesic drugs. A selective N-type calcium channel inhibitor, ziconotide (Prialt), is a neuroactive peptide recently marketed as a novel nonopioid treatment for severe chronic pain. To develop a small-molecule N-type calcium channel blocker, the authors developed a 96-well plate high-throughput screening scintillation proximity assay (SPA) for N-type calcium channel blockers using [125I]-labeled omega-conotoxin GVIA as a channel-specific ligand. Assay reagents were handled using Caliper's Allegro automation system, and bound ligands were detected using a PerkinElmer TopCount. Using this assay, more than 150,000 compounds were screened at 10 microM and approximately 340 compounds were identified as hits, exhibiting at least 40% inhibition of [125I]GVIA binding. This is the 1st demonstration of the use of [125I]-labeled peptides with SPA beads to provide a binding assay for the evaluation of ligand binding to calcium channels. This assay could be a useful tool for drug discovery. Ziconotide is a novel peptide that blocks the entry of calcium into neuronal N-type voltage-sensitive calcium channels, preventing the conduction of nerve signals. N-type calcium channels are present in the superficial laminae of the dorsal horn of the spinal cord. In various animal models of pain, intrathecal administration of ziconotide blocked nerve transmission and nociception. The United States Food and Drug Administration recently approved ziconotide intrathecal infusion for the management of severe chronic pain in patients who require intrathecal therapy and who are intolerant of or refractory to other treatment, such as systemic analgesics, adjunctive therapies, or intrathecal morphine. The drug has a narrow therapeutic window and a lag time for the onset and offset of analgesia and adverse events. In early clinical trials, frequent and severe psychiatric and central nervous system adverse effects were associated with rapid intrathecal infusion (0.4 microg/hr) and frequent up-titration (every 12 hrs). Therefore, patients with psychiatric symptoms are not candidates for this drug. Drug trials of external intrathecal catheters and microinfusion devices demonstrated a 3% risk of meningitis. A low initial infusion rate of 0.1 microg/hour and limiting infusion rate increases to 2-3 times/week are now recommended. Patients responsive to intrathecal ziconotide require an implanted infusion system to receive long-term therapy. Biological, genetic, and clinical evidence provide validation for N-type calcium channels (Ca(V)2.2) as therapeutic targets for chronic pain. A state-dependent Ca(V)2.2 inhibitor may provide an improved therapeutic window over ziconotide, the peptidyl Ca(V)2.2 inhibitor used clinically. Supporting this notion, we recently reported that in preclinical models, the state-dependent Ca(V)2 inhibitor (3R)-5-(3-chloro-4-fluorophenyl)-3-methyl-3-(pyrimidin-5-ylmethyl)-1-(1H-1,2,4-triazol-3-yl)-1,3-dihydro-2H-indol-2-one (TROX-1) has an improved therapeutic window compared with ziconotide. Here we characterize TROX-1 inhibition of Cav2.2 channels in more detail. When channels are biased toward open/inactivated states by depolarizing the membrane potential under voltage-clamp electrophysiology, TROX-1 inhibits Ca(V)2.2 channels with an IC(50) of 0.11 μM. The voltage dependence of Ca(V)2.2 inhibition was examined using automated electrophysiology. TROX-1 IC(50) values were 4.2, 0.90, and 0.36 μM at -110, -90, and -70 mV, respectively. TROX-1 displayed use-dependent inhibition of Ca(V)2.2 with a 10-fold IC(50) separation between first (27 μM) and last (2.7 μM) pulses in a train. In a fluorescence-based calcium influx assay, TROX-1 inhibited Ca(V)2.2 channels with an IC(50) of 9.5 μM under hyperpolarized conditions and 0.69 μM under depolarized conditions. Finally, TROX-1 potency was examined across the Ca(V)2 subfamily. Depolarized IC(50) values were 0.29, 0.19, and 0.28 μM by manual electrophysiology using matched conditions and 1.8, 0.69, and 1.1 μM by calcium influx for Ca(V)2.1, Ca(V)2.2, and Ca(V)2.3, respectively. Together, these in vitro data support the idea that a state-dependent, non-subtype-selective Ca(V)2 channel inhibitor can achieve an improved therapeutic window over the relatively state-independent Ca(V)2.2-selective inhibitor ziconotide in preclinical models of chronic pain.

How is OCT3 associated with serotonin?

OCT3 plays a role in serotonin clearance

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Mood disorders cause much suffering and are the single greatest cause of lost productivity worldwide. Although multiple medications, along with behavioral therapies, have proven effective for some individuals, millions of people lack an effective therapeutic option. A common serotonin (5-HT) transporter (5-HTT/SERT, SLC6A4) polymorphism is believed to confer lower 5-HTT expression in vivo and elevates risk for multiple mood disorders including anxiety, alcoholism, and major depression. Importantly, this variant is also associated with reduced responsiveness to selective 5-HT reuptake inhibitor antidepressants. We hypothesized that a reduced antidepressant response in individuals with a constitutive reduction in 5-HTT expression could arise because of the compensatory expression of other genes that inactivate 5-HT in the brain. A functionally upregulated alternate transporter for 5-HT may prevent extracellular 5-HT from rising to levels sufficiently high enough to trigger the adaptive neurochemical events necessary for therapeutic benefit. Here we demonstrate that expression of the organic cation transporter type 3 (OCT3, SLC22A3), which also transports 5-HT, is upregulated in the brains of mice with constitutively reduced 5-HTT expression. Moreover, the OCT blocker decynium-22 diminishes 5-HT clearance and exerts antidepressant-like effects in these mice but not in WT animals. OCT3 may be an important transporter mediating serotonergic signaling when 5-HTT expression or function is compromised. The organic cation transporter 3 (OCT3; synonymous: extraneuronal monoamine transporter, EMT, Slc22a3) encodes an isoform of the organic cation transporters and is expressed widely across the whole brain. OCTs are a family of high-capacity, bidirectional, multispecific transporters of organic cations. These also include serotonin, dopamine and norepinephrine making OCTs attractive candidates for a variety of neuropsychiatric disorders including anxiety disorders. OCT3 has been implicated in termination of monoaminergic signalling in the central nervous system. Interestingly, OCT3 mRNA is however also significantly up-regulated in the hippocampus of serotonin transporter knockout mice where it might serve as an alternative reuptake mechanism for serotonin. The examination of the behavioural phenotype of OCT3 knockout mice thus is paramount to assess the role of OCT3. We have therefore subjected mice lacking the OCT3 gene to a comprehensive behavioural test battery. While cognitive functioning in the Morris water maze test and aggression levels measured with the resident-intruder paradigm were in the same range as the respective control animals, OCT3 knockout animals showed a tendency of increased activity and were significantly less anxious in the elevated plus-maze test and the open field test as compared to their respective wild-type controls arguing for a role of OCT3 in the regulation of fear and anxiety, probably by modulating the serotonergic tone in limbic circuitries. The organic cation transporter (OCT) 3 is widely expressed in various organs in humans, and involved in the disposition of many exogenous and endogenous compounds. Several lines of evidence have suggested that OCT3 expressed in the brain plays an important role in the regulation of neurotransmission. Relative to wild-type (WT) animals, Oct3 knockout (KO) mice have displayed altered behavioral and neurochemical responses to psychostimulants such as amphetamine (AMPH) and methamphetamine. In the present study, both in vitro and in vivo approaches were utilized to explore potential mechanisms underlying the disparate neuropharmacological effects observed following AMPH exposure in Oct3 KO mice. In vitro uptake studies conducted in OCT3 transfected cells indicated that dextroamphetamine (d-AMPH) is not a substrate of OCT3. However, OCT3 was determined to be a high-capacity and low-affinity transporter for the neurotransmitters dopamine (DA), norepinephrine (NE), and serotonin (5-HT). Inhibition studies demonstrated that d-AMPH exerts relatively weak inhibitory effects on the OCT3-mediated uptake of DA, NE, 5-HT, and the model OCT3 substrate 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide. The IC(50) values were determined to be 41.5 +/- 7.5 and 24.1 +/- 7.0 microM for inhibiting DA and 5-HT uptake, respectively, while 50% inhibition of NE and 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide uptake was not achieved by even the highest concentration of d-AMPH applied (100 microM). Furthermore, the disposition of d-AMPH in various tissues including the brain, liver, heart, kidney, muscle, intestine, spleen, testis, uterus, and plasma were determined in both male and female Oct3 KO and WT mice. No significant difference was observed between either genotypes or sex in all tested organs and tissues. Our findings suggest that OCT3 is not a prominent factor influencing the disposition of d-AMPH. Additionally, based upon the inhibitory potency observed in vitro, d-AMPH is unlikely to inhibit the uptake of monoamines mediated by OCT3 in the brain. Differentiated neuropharmacological effects of AMPHs noted between Oct3 KO and WT mice appear to be due to the absence of Oct3 mediated uptake of neurotransmitters in the KO mice. BACKGROUND: Murine basophils can contribute to the T(H)2 polarization of the immune response by providing rapidly large amounts of IL-4, which suggests that pharmacologic downregulation of this cytokine might provide a strategy to attenuate pathologies associated with excessive production. OBJECTIVE: We examined a number of physiological and pharmacologic ligands of the organic cation transporter 3 (OCT3), a membrane carrier of biogenic amines, for their inhibitory effect on IL-4 production by basophils, selecting the most efficient compounds for in vivo evaluation in basophil-dependent experimental models. METHODS: IL-4 production by basophils isolated ex vivo or from bone marrow cultures was assessed in response to various stimuli with or without biogenic monoamines or pharmacologic analogs. Selected compounds were administered in vivo to examine their effect on levels of circulating IgE generated during a basophil-dependent T(H)2 response and on basophil activation in mice receiving IL-33. RESULTS: We found a drastic decrease in IL-4 production by stimulated basophils on exposure to serotonin (5-hydroxytryptamine [5-HT]) that is taken up by basophils through the specific high-affinity transporters serotonin transporter and the polyspecific, high-capacity organic cation transporter 3 (OCT3; or Slc22a3) but inhibits their function exclusively through the latter. This downregulation is likewise observed in vivo in response to 5-HT and other OCT3 ligands, as well as in human basophils sorted from PMBCs of nonatopic donors. CONCLUSIONS: We provide evidence for a new means of downregulating IL-4 production by basophils, both in vitro and in vivo, through OCT3 targeted by 5-HT and pharmacologic ligands. The serotonin (5HT) transporter (5HTT) regulates serotonergic neurotransmission by mediating the reuptake of 5HT from the synaptic cleft. Although lacking the high affinity and selectivity of the 5HTT, the brain expresses a large number of other transporters, including the polyspecific organic cation transporters (OCTs). OCT1 and OCT3, members of the potential-sensitive organic cation transporter gene family, physiologically transport a wide spectrum of organic cations. In addition, both transporters mediate low-affinity 5HT transport and, therefore, may participate in the clearance of excessive 5HT. Because concentrations of extracellular 5HT are increased in the brain of 5HTT-deficient mice, they are a model for investigating the role of OCTs in 5HT system homeostasis. Here, we analyzed OCT1 and OCT3 gene expression in the brain of 5HTT knockout mice by semiquantitative competitive polymerase chain reaction and in situ hybridization. We demonstrate that, in 5HTT-deficient mice, OCT3 mRNA concentrations were significantly increased in the hippocampus, but not in other brain regions, including cortex, striatum, cerebellum, and brainstem. In contrast, no difference in OCT1 expression was detected between 5HTT knockout and control mice. Up-regulation of OCT3 expression and enhanced low-affinity 5HT uptake may limit the adverse effects of elevated extracellular 5HT and may play a critical role in maintaining 5HT-dependent functions of the hippocampus in the absence of 5HTT. Organic cation transporter 3 (OCT3) is a high-capacity, low-affinity transporter that mediates bidirectional, sodium-independent transport of dopamine, norepinephrine, epinephrine, serotonin, and histamine. OCT3-mediated transport is directly inhibited by corticosterone, suggesting a potential role for the transporter in mediating some of the effects of stress and glucocorticoids on monoaminergic neurotransmission. To elucidate the importance of OCT3 in clearance of extracellular monoamines in the brain, we used immunohistochemical techniques to describe the distribution of OCT3-like-immunoreactive (OCT3-ir) cells throughout the rostrocaudal extent of adult male rat brains. OCT3-ir cell bodies were widely distributed throughout the brain, with the highest densities observed in the superior and inferior colliculi, islands of Calleja, subiculum, lateral septum, lateral and dorsomedial hypothalamic nuclei, and granule cell layers of the main and accessory olfactory bulbs, the cerebellum, and the retrosplenial granular cortex. OCT3-ir cells and/or fibers were also observed in circumventricular organs, and OCT3-ir ependymal cells were observed in the linings of all cerebral ventricles. The widespread distribution of OCT3-ir cell bodies, including regions receiving dense monoaminergic projections, suggests an important role for this transporter in regulating extracellular concentrations of monoamines in the rat brain and is consistent with the hypothesis that corticosterone-induced inhibition of OCT3-mediated transport may contribute to effects of acute stress or corticosterone on monoaminergic neurotransmission.

What constitutes an increased risk for individuals with Fanconi anemia?

Fanconi anemia is a rare genetic disorder associated with an increased risk of leukemias and solid tumors.

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Fanconi anemia (FA) is a rare autosomal recessive disease characterized by skeletal defects, anemia, chromosomal instability and increased risk of leukemia. At the cellular level FA is characterized by increased sensitivity to agents forming interstrand crosslinks (ICL) in DNA. Six FA genes have been cloned and interactions among individual FANC proteins have been found. The FANCD2 protein co-localizes in nuclear foci with the BRCA1 protein following DNA damage and during S-phase, requiring the FANCA, C, E and G proteins to do so. This finding may reflect a direct role for the BRCA1 protein in double strand break (DSB) repair and interaction with the FANC proteins. Therefore interactions between BRCA1 and the FANC proteins were investigated. Among the known FANC proteins, we find evidence for direct interaction only between the FANCA protein and BRCA1. The evidence rests on three different tests: yeast two-hybrid analysis, coimmunoprecipitation from in vitro synthesis, and coimmunoprecipitation from cell extracts. The amino terminal portion of FANCA and the central part (aa 740-1083) of BRCA1 contain the sites of interaction. The interaction does not depend on DNA damage, thus FANCA and BRCA1 are constitutively interacting. The demonstrated interaction directly connects BRCA1 to the FA pathway of DNA repair. Fanconi anemia is a genetically heterogeneous disorder associated with chromosome instability and a highly elevated risk for developing cancer. The mutated genes encode proteins involved in the cellular response to DNA replication stress. Fanconi anemia proteins are extensively connected with DNA caretaker proteins, and appear to function as a hub for the coordination of DNA repair with DNA replication and cell cycle progression. At a molecular level, however, the raison d'être of Fanconi anemia proteins still remains largely elusive. The thirteen Fanconi anemia proteins identified to date have not been embraced into a single and defined biological process. To help put the Fanconi anemia puzzle into perspective, we begin this review with a summary of the strategies employed by prokaryotes and eukaryotes to tolerate obstacles to the progression of replication forks. We then summarize what we know about Fanconi anemia with an emphasis on biochemical aspects, and discuss how the Fanconi anemia network, a late acquisition in evolution, may function to permit the faithful and complete duplication of our very large vertebrate chromosomes. Fanconi anemia is an inherited disease characterized by bone marrow failure, congenital malformations, and predisposition to cancer. The breast cancer susceptibility gene BRCA2 was recently found to be associated with Fanconi anemia complementation group D1 (FA-D1). We examined four kindreds afflicted with Fanconi anemia for the presence of germline BRCA2 mutations. One kindred, of Ashkenazi Jewish ancestry, had five members who were diagnosed with breast cancer and two cousins who were BRCA2*6174delT/C3069X compound heterozygotes and had Fanconi anemia and brain tumors. In another kindred of Ashkenazi Jewish and Lithuanian Catholic ancestry, a child with Fanconi anemia and a medulloblastoma was a BRCA2*6174delT/886delGT compound heterozygote. Two other kindreds each contained a Fanconi anemia-afflicted child who developed medulloblastoma; one child was of Latin American ancestry and a compound heterozygote for BRCA2*I2490T/ 5301insA and the other was African American and a compound heterozygote for BRCA2*Q3066X/E1308X. Median age of the Fanconi anemia-afflicted children at brain tumor diagnosis was 3.5 years. The co-occurrence of brain tumors, Fanconi anemia, and breast cancer observed in one of these kindreds constitutes a new syndromic association. Individuals who carry a germline BRCA2 mutation and who plan to have children with a partner of Ashkenazi Jewish descent should consider undergoing genetic counseling. Fanconi anemia (FA) is a heterogeneous disease characterized by spontaneous chromosomal breaks and abnormal DNA repair. Major clinical problems in FA include congenital abnormalities, endocrinopathies, early onset bone marrow failure and increased risk of myelodysplastic syndrome, acute leukemia and solid tumors. To date, 15 different genes have been shown to cause FA, all of which have some role in DNA double-strand break repair. Very few strict genotype-phenotype associations have been identified and clinical manifestations vary widely from patient to patient, most likely due to modifier genes, environment and chance effects. Hematopoietic stem cell transplantation is the only proven cure for the hematopoietic manifestations of FA and aggressive lifelong surveillance for solid tumors is essential. Fanconi anemia (FA) is a rare recessive DNA repair disorder that is clinically characterized by congenital malformations, progressive bone marrow failure, and increased incidence of malignancies, especially acute myeloid leukemia and squamous cell carcinomas of the head and neck (HNSCCs) and the anogenital regions. On a cellular level, typical features of the disorder are a high degree of genomic instability and an increased sensitivity to bi-functionally alkylating agents. So far, germ-line defects in 15 different FA genes have been identified. Some of these FA genes are also established as tumor susceptibility genes for familiar cancers.In recent years, the prevention and therapy of HNSCCs in FA patients has become more important as the percentage of patients surviving into adulthood is rising. HNSCCs appear in very young FA patients without common risk factors. Since cisplatin-based chemotherapy in combination with radiotherapy, essential parts of the standard treatment approach for sporadic HNSCCs, cannot be used in FA patients due to therapy-associated toxicities and mortalities even with reduced dosing, surgery is the most important treatment option for HNSCCs, in FA patients and requires an early and efficient detection of malignant lesions. So far, no uniform treatment protocol for the management of HNSCCs in FA patients exists. Therefore, we propose that the information on affected FA patients should be collected worldwide, practical therapeutic guidelines developed and national treatment centers established. BACKGROUND: Fanconi anemia (FA) is an autosomal recessive, cancer susceptibility disorder characterized by diverse clinical features, such as short stature, skeletal or skin abnormalities, progressive bone marrow (BM) failure, and increased risk of malignancies. Clonal chromosomal abnormalities are frequently reported in FA patients transformed to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). AIM: To study the incidence of malignancy and clonal chromosomal abnormalities in FA patients. MATERIALS AND METHODS: Thirty-eight clinically diagnosed FA patients were studied at the time of diagnosis and the patients were followed-up for a maximum of 28 months at 3-month intervals. The median duration of follow-up of these patients was 19.8 months. Chromosomal breakage investigation using mitomycin C (MMC)- and diepoxybutane (DEB)-induced peripheral blood cultures were stimulated with phytohemagglutinin. Cytogenetic study was done on the BM cells to detect clonal chromosomal aberrations. RESULTS: Eleven (28.95%) out of 38 patients developed malignancies, including 6 (54.54%) MDS, 4 (36.36%) AML, and 1 (2.63%) squamous cell carcinoma. The clonal chromosomal abnormalities were detected in 5 (45.45%) FA patients who developed malignancies and the type of chromosomal abnormality detected were monosomies 5, 7, trisomy 10, dup(1)(q12-q24), and inv(7)(p11pter). CONCLUSION: The FA patients have a high risk of developing malignancies, and clonal chromosomal abnormalities play an important role in the prognosis of the disease. Therefore, FA patients need to be followed-up at regular intervals for early diagnosis and optimal management of the disease. Genes of the Fanconi complementation groups [Fanconi anemia (FA) genes] are suggested to be involved in homologous DNA recombination and produce FA when two allelic mutations are inherited. BRCA2 is an FA gene and additionally conveys an inherited risk for breast, ovarian, and pancreatic cancer for individuals carrying a single mutated allele [N. G. Howlett et al., Science (Wash. DC), 297: 606-609, 2002]. Here we report inherited and somatic mutations of FANCC and FANCG present in young-onset pancreatic cancer. This may imply a general involvement of Fanconi genes with an inherited risk of cancer. The known hypersensitivity of Fanconi cells to mitomycin and other therapeutic agents [M. S. Sasaki, Nature (Lond.), 257: 501-503, 1975] suggests a therapeutic utility for a more complete characterization of the DNA repair defects and their causative genetic mutations in pancreatic cancer. The incidence of esophageal squamous cell carcinoma (ESCC) is very high in northeastern Iran. Previously, we reported a strong familial component of ESCC among Turkmens, who constitute approximately one-half of the population of this region. We hypothesized that the genes which cause Fanconi anemia might be candidate genes for ESCC. We sequenced the entire coding regions of 12 Fanconi anemia genes in the germline DNA of 190 Turkmen cases of ESCC. We identified three heterozygous insertion/deletion mutations: one in FANCD2 (p.Val1233del), one in FANCE (p.Val311SerfsX2), and one in FANCL (p.Thr367AsnfsX13). All three patients had a strong family history of ESCC. In addition, four patients (out of 746 tested) were homozygous for the FANCA p.Ser858Arg mutation, compared to none of 1,373 matched controls (OR = 16.7, 95% CI = 6.2-44.2, P = 0.01). The p. Lys3326X mutation in BRCA2 (also known as Fanconi anemia gene FANCD1) was present in 27 of 746 ESCC cases and in 16 of 1,373 controls (OR = 3.38, 95% CI = 1.97-6.91, P = 0.0002). In summary, both heterozygous and homozygous mutations in several Fanconi anemia-predisposing genes are associated with an increased risk of ESCC in Iran. Three patients with Fanconi's anemia were analyzed for chromosome breaks. T and B cells were separated and grown in tissue culture with PHA and pokeweed antigen to ascertain the rates of breakage in these lymphocytic subpopulations. It has been found that there is no statistically significant difference in breakage rates in T and B lymphocytes. It is postulated that both T and B cells could be involved in the development of leukemia in Fanconi's anemia patients, assuming that chromosome breaks constitute a factor predisposing to the development of malignancy. Fanconi anemia (FA) is a rare autosomal recessive disease characterized by a greatly increased risk of cancer among those diagnosed with the syndrome. The question as to whether FA heterozygotes are at increased risk for cancer is of great importance to those at risk for being a carrier. To address this question, we formed a cohort of grandparents of probands identified through the International Fanconi Anemia Registry. We obtained informed consent, a short questionnaire, and either blood or buccal swab DNA. After diagnosis of the proband was confirmed and complementation studies or DNA sequencing on the proband were completed, mutation analyses of the putative carriers and noncarriers was carried out. Standardized incidence ratios (SIR) were calculated to compare the observed cancer incidence of the grandparents and other relatives with the expected rates of cancer, using the Surveillance, Epidemiology, and End Results registries and the Connecticut Cancer registry. In the 944 study subjects who participated (784 grandparents and 160 other relatives), there was no suggestion of an increase in overall cancer incidence. On the other hand, a significantly higher rate of breast cancer than expected was observed among carrier grandmothers [SIR, 1.7; 95% confidence interval (95% CI), 1.1-2.7]. Among the grandmothers, those who were carriers of FANCC mutations were found to be at highest risk (SIR, 2.4; 95% CI, 1.1-5.2). Overall, there was no increased risk for cancer among FA heterozygotes in this study of Fanconi relatives, although there is some evidence that FANCC mutations are possibly breast cancer susceptibility alleles. Fanconi anaemia (FA) is an inherited condition characterised by congenital and developmental abnormalities and a strong cancer predisposition. In around 3-5% of cases FA is caused by biallelic mutations in the BRCA2 gene. Individuals heterozygous for BRCA2 mutations have an increased risk of inherited breast and ovarian cancer. We reviewed the mutation spectrum in BRCA2-associated FA, and the spectrum and frequency of BRCA2 mutations in distinct populations. The rarity of FA due to biallelic BRCA2 mutations supports a fundamental role of BRCA2 for prevention of malignant transformation during development. The spectrum of malignancies seen associated with FA support the concept of a tissue selectivity of BRCA2 mutations for development of FA-associated cancers. This specificity is illustrated by the distinct FA-associated BRCA2 mutations that appear to predispose to specific brain or haematological malignancies. For some populations, the number of FA-patients with biallelic BRCA2 disruption is smaller than that expected from the carrier frequency, and this implies that some pregnancies with biallelic BRCA2 mutations do not go to term. The apparent discrepancy between expected and observed incidence of BRCA2 mutation-associated FA in high-frequency carrier populations has important implications for the genetic counselling of couples with recurrent miscarriages from high-risk populations. Fanconi anemia (FA) is an inherited disease characterized by bone marrow failure, increased cancer risk and hypersensitivity to DNA cross-linking agents, implying a role for this pathway in the maintenance of genomic stability. The central player of the FA pathway is the multi-subunit E3 ubiquitin ligase complex activated through a replication- and DNA damage-dependent mechanism. A consequence of the activation of the complex is the monoubiquitylation of FANCD2 and FANCI, late term effectors in the maintenance of genome integrity. The details regarding the coordination of the FA-dependent response and the DNA replication process are still mostly unknown. We found, by yeast two-hybrid assay and co-immunoprecipitation in human cells, that the core complex subunit FANCF physically interacts with PSF2, a member of the GINS complex essential for both the initiation and elongation steps of DNA replication. In HeLa cells depleted for PSF2, we observed a decreased binding to chromatin of the FA core complex, suggesting that the GINS complex may have a role in either loading or stabilizing the FA core complex onto chromatin. Consistently, GINS and core complex bind chromatin contemporarily upon origin firing and PSF2 depletion sensitizes cells to DNA cross-linking agents. However, depletion of PSF2 is not sufficient to reduce monoubiquitylation of FANCD2 or its localization to nuclear foci following DNA damage. Our results suggest a novel crosstalk between DNA replication and the FA pathway. BACKGROUND: Fanconi anemia (FA) is an autosomal recessive DNA repair disorder with affected individuals having a high risk of developing acute myeloid leukaemia and certain solid tumours. Thirteen complementation groups have been identified and the genes for all of these are known (FANCA, B, C, D1/BRCA2, D2, E, F, G, I, J/BRIP1, L, M and N/PALB2). Previous studies of cancer incidence in relatives of Fanconi anemia cases have produced conflicting results. A study of British FA families was therefore carried out to investigate this question, since increases in cancer risk in FA heterozygotes would have implications for counselling FA family members, and possibly also for the implementation of preventative screening measures in FA heterozygotes. METHODS: Thirty-six families took part and data was collected on 575 individuals (276 males, 299 females), representing 18,136 person years. In this cohort, 25 males and 30 females were reported with cancer under the age of 85 years, and 36 cancers (65%) could be confirmed from death certificates, cancer registries or clinical records. RESULTS: A total of 55 cancers were reported in the FA families compared to an estimated incidence of 56.95 in a comparable general population cohort, and the relative risk of cancer was 0.97 (95% C.I. = 0.71-1.23, p = 0.62) for FA family members. Analysis of relative risk for individual cancer types in each carrier probability group did not reveal any significant differences with the possible exception of prostate cancer (RR = 3.089 (95% C.I. = 1.09 - 8.78; Chi2 = 4.767, p = 0.029). CONCLUSION: This study has not shown a significant difference in overall cancer risk in FA families. BACKGROUND: Fanconi anemia (FA) is a rare autosomal recessive genetic disorder characterized by bone marrow failure and increased risk of cancers including acute myelogenous leukemia and various solid tumors, especially head and neck cancer. Management of head and neck cancer in the setting of FA is complicated by pancytopenia, poor tolerance of chemotherapy, and potentially increased radiosensitivity. There are limited reports on tolerance of radiotherapy (RT) in patients with FA. METHODS: We report a case of a patient with FA who presented with a small oral tongue cancer that was excised. He rapidly developed extensive locoregional recurrence and underwent surgical resection followed by postoperative RT with concurrent cetuximab. RESULTS: Both RT and cetuximab were well tolerated with manageable toxicities. Unfortunately, the patient died of early locoregional disease progression. CONCLUSIONS: RT with concurrent cetuximab was well tolerated and may be an appropriate option in patients with FA. However, many patients have a poor prognosis due to aggressive disease.

Is stop codon bypass possible?

In 1999, proof-of-concept for treating these disorders was obtained in a mouse model of muscular dystrophy, when administration of aminoglycosides restored protein translation by inducing the ribosome to bypass a PTC. Aminoglycosides can bypass nonsense mutations and are the prototypic agents for translational bypass therapy (TBT). Expression of retroviral replication enzymes (Pol) requires a controlled translational recoding event to bypass the stop codon at the end of gag. This recoding event occurs either by direct suppression of termination via the insertion of an amino acid at the stop codon (readthrough) or by alteration of the mRNA reading frame (frameshift).

[17961216, 11492998, 7479046, 17158156, 17187982, 18809619, 2103444, 2010914, 23083810, 10102819, 23649834, 2691247, 9223347, 2207158, 21969101, 22718819, 9537381, 17881586, 12711673]

BACKGROUND: In the C. albicans retrotransposon Tca2, the gag and pol ORFs are separated by a UGA stop codon, 3' of which is a potential RNA pseudoknot. It is unclear how the Tca2 gag UGA codon is bypassed to allow pol expression. However, in other retroelements, translational readthrough of the gag stop codon can be directed by its flanking sequence, including a 3' pseudoknot. RESULTS: The hypothesis was tested that in Tca2, gag stop codon flanking sequences direct translational readthrough and synthesis of a gag-pol fusion protein. Sequence from the Tca2 gag-UGA-pol junction (300 nt) was inserted between fused lacZ and luciferase (luc) genes in a Saccharomyces cerevisiae dual reporter construct. Although downstream of UGA, luc was expressed, but its expression was unaffected by inserting additional stop codons at the 3' end of lacZ. Luc expression was instead being driven by a previously unknown minor promoter activity within the gag-pol junction region. Evidence together indicated that junction sequence alone cannot direct UGA readthrough. Using reporter genes in C. albicans, the activities of this gag-pol junction promoter and the Tca2 long terminal repeat (LTR) promoter were compared. Of the two promoters, only the LTR promoter was induced by heat-shock, which also triggers retrotransposition. Tca2 pol protein, epitope-tagged in C. albicans to allow detection, was also heat-shock induced, indicating that pol proteins were expressed from a gag-UGA-pol RNA. CONCLUSION: This is the first demonstration that the LTR promoter directs Tca2 pol protein expression, and that pol proteins are translated from a gag-pol RNA, which thus requires a mechanism for stop codon bypass. However, in contrast to most other retroelement and viral readthrough signals, immediate gag UGA-flanking sequences were insufficient to direct stop readthrough in S. cerevisiae, indicating non-canonical mechanisms direct gag UGA bypass in Tca2. Ribosomes bypass a 50 nucleotide non-coding segment of mRNA between the two open reading frames of bacteriophage T4 gene 60 in order to synthesize a topoisomerase subunit. While nearly all ribosomes appear to initiate bypassing, only 50 % resume translation in the second open reading frame. Failure to bypass is shown here to be independent of the stop codon at the end of the first open reading frame and to be amplified by mutant variants of tRNA(Gly)(2) known to diminish bypassing efficiency. Unproductive bypassing may result from premature dissociation of peptidyl-tRNAs from ribosomes (drop-off) or resumption of translation at inappropriate sites. Assessment of the influence of factors known to induce drop-off reveals that ribosome recycling factor accounts for a small fraction of unproductive bypassing products, but none of the other known factors appear to play a significant role. Resumption of translation at inappropriate sites appears to be minimal, which suggests that spontaneous release of the peptidyl-tRNA may account for the remaining unproductive bypassing products and may be inherent to the gene 60 bypassing mechanism. Translation of yeast GCN4 mRNA occurs by a reinitiation mechanism that is modulated by amino acid levels in the cell. Ribosomes which translate the first of four upstream open reading frames (uORFs) in the mRNA leader resume scanning and can reinitiate downstream. Under non-starvation conditions reinitiation occurs at one of the remaining three uORFs and GCN4 is repressed. Under starvation conditions, in contrast, ribosomes bypass the uORFs and reinitiate at GCN4 instead. The high frequency of reinitiation following uORF1 translation depends on an adequate distance to the next start codon and particular sequences surrounding the uORF1 stop codon. We present evidence that sequences 5' to uORF1 also strongly enhance reinitiation. First, reinitiation was severely inhibited when uORF1 was transplanted into the position of uORF4, even though the native sequence environment of the uORF1 stop codon was maintained, and this effect could not be accounted for by the decreased uORF1-GCN4 spacing. Second, insertions and deletions in the leader preceding uORF1 greatly reduced reinitiation at GCN4. Sequences 5' to uORF1 may influence the probability of ribosome release following peptide termination at uORF1. Alternatively, they may facilitate rebinding of an initiation factor required for reinitiation prior to resumption of the scanning process. Stop codons are used to signal the ribosome to terminate the decoding of an mRNA template. Recent studies on translation termination in the yeast Saccharomyces cerevisiae have not only enabled the identification of the key components of the termination machinery, but have also revealed several regulatory mechanisms that might enable the controlled synthesis of C-terminally extended polypeptides via stop-codon readthrough. These include both genetic and epigenetic mechanisms. Rather than being a translation 'error', stop-codon readthrough can have important effects on other cellular processes such as mRNA degradation and, in some cases, can confer a beneficial phenotype to the cell. The extensive molecular genetic heterogeneity seen with inherited eye disease is a major barrier to the development of gene-based therapeutics. The underlying molecular pathology in a considerable proportion of these diseases however are nonsense mutations leading to premature termination codons. A therapeutic intervention targeted at this abnormality would therefore potentially be relevant to a wide range of inherited eye diseases. We have taken advantage of the ability of aminoglycoside drugs to suppress such nonsense mutations and partially restore full-length, functional protein in a zebrafish model of choroideraemia (chm(ru848); juvenile chorio-retinal degeneration) and in two models of ocular coloboma (noi(tu29a) and gup(m189); congenital optic fissure closure defects). In vitro cell-based assays showed significant readthrough with two drugs, gentamicin and paromomycin, which was confirmed by western blot and in vitro prenylation assays. The presence of either aminoglycoside during zebrafish development in vivo showed remarkable prevention of mutant ocular phenotypes in each model and a reduction in multisystemic defects leading to a 1.5-1.7-fold increase in survival. We also identified a significant reduction in abnormal cell death shown by TUNEL assay. To test the hypothesis that optic fissure closure was apoptosis-dependent, the anti-apoptotic agents, curcumin and zVAD-fmk, were tested in gup(m189) embryos. Both drugs were found to reduce the size of the coloboma, providing molecular evidence that cell death is required for optic fissure remodelling. These findings draw attention to the value of zebrafish models of eye disease as useful preclinical drug screening tools in studies to identify molecular mechanisms amenable to therapeutic intervention. Plant RNA viruses commonly exploit leaky translation termination signals in order to express internal protein coding regions. As a first step to elucidate the mechanism(s) by which ribosomes bypass leaky stop codons in vivo, we have devised a system in which readthrough is coupled to the transient expression of beta-glucuronidase (GUS) in tobacco protoplasts. GUS vectors that contain the stop codons and surrounding nucleotides from the readthrough regions of several different RNA viruses were constructed and the plasmids were tested for the ability to direct transient GUS expression. These studies indicated that ribosomes bypass the leaky termination sites at efficiencies ranging from essentially 0 to ca. 5% depending upon the viral sequence. The results suggest that the efficiency of readthrough is determined by the sequence surrounding the stop codon. We describe improved GUS expression vectors and optimized transfection conditions which made it possible to assay low-level translational events. Expression of the RNA replicase domain of tobacco mosaic virus (TMV) and certain protein-coding regions in other plant viruses, is mediated by translational readthrough of a leaky UAG stop codon. It has been proposed that normal tobacco tyrosine tRNAs are able to read the UAG codon of TMV by non-conventional base-pairing but recent findings that stop codons can also be bypassed as a result of extended translocational shifts (tRNA hopping) have encouraged a re-examination. In light of the alternatives, we investigated the sequences flanking the leaky UAG codon using an in vivo assay in which bypass of the stop codon is coupled to the transient expression of beta-glucuronidase (GUS) reporter genes in tobacco protoplasts. Analysis of GUS constructions in which codons flanking the stop were altered allowed definition of the minimal sequence required for read through as UAG-CAA-UUA. The effects of all possible single-base mutations in the codons flanking the stop indicated that 3' contexts of the form CAR-YYA confer leakiness and that the 3' context permits read through of UAA and UGA stop codons as well as UAG. Our studies demonstrate a major role for the 3' context in the read through process and do not support a model in which teh UAG is bypassed exclusively as a result of anticodon-codon interactions. No evidence for tRNA hopping was obtained. The 3' context apparently represents a unique sequence element that affects translation termination. Ten percent of inherited diseases are caused by premature termination codon (PTC) mutations that lead to degradation of the mRNA template and to the production of a non-functional, truncated polypeptide. In addition, many acquired mutations in cancer introduce similar PTCs. In 1999, proof-of-concept for treating these disorders was obtained in a mouse model of muscular dystrophy, when administration of aminoglycosides restored protein translation by inducing the ribosome to bypass a PTC. Since, many studies have validated this approach, but despite the promise of PTC readthrough therapies, the mechanisms of translation termination remain to be precisely elucidated before even more progress can be made. Here, we review the molecular basis for PTC readthrough in eukaryotes and describe currently available compounds with significant therapeutic potential for treating genetic disorders and cancer. Cytosine deamination to uracil occurs frequently in cellular DNA. In vitro, RNA polymerase efficiently inserts adenine opposite to uracil, resulting in G to A base substitutions. In vivo, uracil could potentially alter transcriptional fidelity, resulting in production of mutant proteins. This study demonstrates that in nondividing Escherichia coli cells, a DNA template base replaced with uracil in a stop codon in the firefly luciferase gene results in conversion of inactive to active luciferase. The level of transcriptional base substitution is dependent on the capacity to repair uracil. These results provide evidence for a DNA damage-dependent, transcription-driven pathway for generating mutant proteins in nondividing cells. Our goal was to identify evolutionary conserved frame transitions in protein coding regions and to uncover an underlying functional role of these structural aberrations. We used the ab initio frameshift prediction program, GeneTack, to detect reading frame transitions in 206 991 genes (fs-genes) from 1106 complete prokaryotic genomes. We grouped 102 731 fs-genes into 19 430 clusters based on sequence similarity between protein products (fs-proteins) as well as conservation of predicted position of the frameshift and its direction. We identified 4010 pseudogene clusters and 146 clusters of fs-genes apparently using recoding (local deviation from using standard genetic code) due to possessing specific sequence motifs near frameshift positions. Particularly interesting was finding of a novel type of organization of the dnaX gene, where recoding is required for synthesis of the longer subunit, τ. We selected 20 clusters of predicted recoding candidates and designed a series of genetic constructs with a reporter gene or affinity tag whose expression would require a frameshift event. Expression of the constructs in Escherichia coli demonstrated enrichment of the set of candidates with sequences that trigger genuine programmed ribosomal frameshifting; we have experimentally confirmed four new families of programmed frameshifts. A translational frameshift is necessary in the synthesis of Escherichia coli release factor 2 (RF-2) to bypass an in-frame termination codon within the coding sequence. The nucleotide sequence preceding the in-phase stop codon within RF-2 mRNA is complementary to the 3' anti-(Shine-Dalgarno sequence) region found in prokaryotic 16S rRNA and Weiss et al. (1988) have concluded that this pairing triggers the frameshift event. In vitro production of RNA coding for RF-2, suitable for translation on eukaryotic ribosomes, has enabled testing of whether eukaryotic ribosomes can frameshift at this sequence. The 18S rRNA of eukaryotic ribosomes does not contain the 3' anti-(Shine-Dalgarno sequence) region. The prokaryotic RF-2 gene and the gene for the other release factor, RF-1, which does not contain an in-frame stop codon, were subcloned into transcription vectors such that the RNA transcripts produced in vitro would resemble a typical eukaryotic mRNA. These RF-1 and RF-2 RNAs both synthesized a major product of Mr approximately 45,000 when translated in vitro within reticulocyte lysate; the size expected for full length RF-1 and RF-2 molecules. The RF-2 product was immunoprecipitated by RF-2-specific antibodies, including those to regions of the protein encoded in the mRNA downstream from the frameshift site. The putative premature termination product, an oligopeptide of 25 amino acids, was not detected, but a chemically synthesized derivative was shown to be very unstable within the translation system. Although it was not possible therefore to calculate an absolute efficiency of frameshifting, the relative efficiency of the translation of RF-2 RNA was estimated to be 10-20% of that of RF-1 RNA in the reticulocyte system. This was similar to the relative synthesis of the two proteins in a plasmid-DNA-directed prokaryotic transcription/translation system. These results show that in vitro on eukaryotic ribosomes where the Shine-Dalgarno-type interaction is not possible, high efficiency frameshifting around the in-phase stop codon in the RF-2 mRNA can still occur. We isolated from a tomato cDNA library the tomPRO1 locus, which encodes gamma-glutamyl kinase (GK) and gamma-glutamyl phosphate reductase (GPR). This locus is unusual among eukaryotic genetic elements because it contains two open reading frames, and thus resembles prokaryotic polycistronic operons. The first open reading frame, specifying GK, is terminated by a TAA codon, which is followed by five nucleotides, an ATG translation initiation codon, and the second open reading frame, encoding GPR. DNA sequence analysis of fragments obtained by PCR amplification confirmed that the internal TAA and neighboring sequences are present in the endogenous tomPRO1 sequence in tomato. We demonstrated with RNase protection assays that the tomPRO1 locus is transcribed in tomato tissue culture cells, into a product that contains the internal stop codon. In Escherichia coli, tomPRO1 directed the synthesis of two proteins, a 33-kDa GK and a 44-kDa GPR. Antibodies against the 44-kDa GPR purified from E. coli recognized a 70-kDa product in tomato tissue culture cells and a 60-kDa product in leaves and roots. These results suggest that in tomato tissues, GPR is made as part of a longer polypeptide by some translational mechanism that enables bypass of the internal stop codon, such as frameshifting or ribosome hopping. The tomPRO1 locus may be the first example of a nuclear genetic element in plants that encodes two functional enzymes in two distinct open reading frames. Several genetic diseases are triggered by nonsense mutations leading to the formation of truncated and defective proteins. Aminoglycosides have the capability to mediate a bypass of stop mutations during translation thus resulting in a rescue of protein expression. So far no attention has been directed to obesity-associated stop mutations as targets for nonsense suppression. Herein, we focus on the characterization of the melanocortin-4-receptor (MC4R) nonsense allele W16X identified in obese subjects. Cell culture assays revealed a loss-of-function of Mc4r(X16) characterized by impaired surface expression and defect signaling. The aminoglycoside G-418 restored Mc4r(X16) function in vitro demonstrating that Mc4r(X16) is susceptible to nonsense suppression. For the evaluation of nonsense suppression in vivo, we generated a Mc4r(X16) knock-in mouse line by gene targeting. Mc4r(X16) knock-in mice developed hyperphagia, impaired glucose tolerance, severe obesity and an increased body length demonstrating that this new mouse model resembles typical characteristics of Mc4r deficiency. In a first therapeutic trial, the aminoglycosides gentamicin and amikacin induced no amelioration of obesity. Further experiments with Mc4r(X16) knock-in mice will be instrumental to establish nonsense suppression for Mc4r as an obesity-associated target gene expressed in the central nervous system. Expression of retroviral replication enzymes (Pol) requires a controlled translational recoding event to bypass the stop codon at the end of gag. This recoding event occurs either by direct suppression of termination via the insertion of an amino acid at the stop codon (readthrough) or by alteration of the mRNA reading frame (frameshift). Here we report the effects of a host protein, large ribosomal protein 4 (RPL4), on the efficiency of recoding. Using a dual luciferase reporter assay, we found that transfection of cells with a plasmid encoding RPL4 cDNA increases recoding efficiency in a dose-dependent manner, with a maximal enhancement of nearly twofold. Expression of RPL4 increases recoding of reporters containing retroviral readthrough and frameshift sequences, as well as the Sindbis virus leaky termination signal. RPL4-induced enhancement of recoding is cell line specific and appears to be specific to RPL4 among ribosomal proteins. Cotransfection of RPL4 cDNA with Moloney murine leukemia proviral DNA results in Gag processing defects and a reduction of viral particle formation, presumably caused by the RPL4-dependent alteration of the Gag-to-Gag-Pol ratio required for virion assembly and release. Aminoglycosides can bypass nonsense mutations and are the prototypic agents for translational bypass therapy (TBT). Initial results demonstrate the need for more potent drugs and an in vivo model system for quantitative assessment of TBT. Herein, we present an in vivo system for evaluating the efficacy of premature stop codon management therapies: in vivo quantitative stop codon management repli-sampling TBT efficacy assay (IQSCMaRTEA). Application of IQSCMaRTEA reveals that geneticin is much more efficacious in vivo than gentamicin. Treatment with geneticin elicits a multiday response, and residual F9 antigen can be detected after 3 weeks. These data demonstrate the utility of IQSCMaRTEA for evaluating drugs that bypass nonsense mutations. In addition, IQSCMaRTEA may be helpful for testing inhibitors of nonsense-mediated decay, as stop codon management therapy will sometimes require inhibition of nonsense-mediated decay and translational bypass of the nonsense mutation. Furthermore, geneticin, its metabolites, or better tolerated analogues should be evaluated as a general treatment with multiday response for severe genetic disease caused by nonsense mutation.

Is the protein β1-integrin recycled?

Yes, the β1-integrin is recycled.

[24036548, 25344254, 23264734, 22561348, 24719112, 22222055, 24887021, 26256210, 22454518, 23839032, 23139422]

Cell migration is dependent on a series of integrated cellular events including the membrane recycling of the extracellular matrix receptor integrins. In this paper, we investigate the role of autophagy in regulating cell migration. In a wound-healing assay, we observed that autophagy was reduced in cells at the leading edge than in cells located rearward. These differences in autophagy were correlated with the robustness of MTOR activity. The spatial difference in the accumulation of autophagic structures was not detected in rapamycin-treated cells, which had less migration capacity than untreated cells. In contrast, the knockdown of the autophagic protein ATG7 stimulated cell migration of HeLa cells. Accordingly, atg3(-/-) and atg5(-/-) MEFs have greater cell migration properties than their wild-type counterparts. Stimulation of autophagy increased the co-localization of β1 integrin-containing vesicles with LC3-stained autophagic vacuoles. Moreover, inhibition of autophagy slowed down the lysosomal degradation of internalized β1 integrins and promoted its membrane recycling. From these findings, we conclude that autophagy regulates cell migration, a central mechanism in cell development, angiogenesis, and tumor progression, by mitigating the cell surface expression of β1 integrins. Chloride intracellular channel protein 4 (CLIC4) exists in both soluble and membrane-associated forms, and is implicated in diverse cellular processes, ranging from ion channel formation to intracellular membrane remodeling. CLIC4 is rapidly recruited to the plasma membrane by lysophosphatidic acid (LPA) and serum, suggesting a possible role for CLIC4 in exocytic-endocytic trafficking. However, the function and subcellular target(s) of CLIC4 remain elusive. Here, we show that in HeLa and MDA-MB-231 cells, CLIC4 knockdown decreases cell-matrix adhesion, cell spreading and integrin signaling, whereas it increases cell motility. LPA stimulates the recruitment of CLIC4 to β1 integrin at the plasma membrane and in Rab35-positive endosomes. CLIC4 is required for both the internalization and the serum- or LPA-induced recycling of β1 integrin, but not for EGF receptor trafficking. Furthermore, we show that CLIC4 suppresses Rab35 activity and antagonizes Rab35-dependent regulation of β1 integrin trafficking. Our results define CLIC4 as a regulator of Rab35 activity and serum- and LPA-dependent integrin trafficking. Cells inversely adjust the plasma membrane levels of integrins and cadherins during cell migration and cell-cell adhesion but the regulatory mechanisms that coordinate these trafficking events remain unknown. Here, we demonstrate that the small GTPase Rab35 maintains cadherins at the cell surface to promote cell-cell adhesion. Simultaneously, Rab35 supresses the activity of the GTPase Arf6 to downregulate an Arf6-dependent recycling pathway for β1-integrin and EGF receptors, resulting in inhibition of cell migration and attenuation of signaling downstream of these receptors. Importantly, the phenotypes of decreased cell adhesion and increased cell migration observed following Rab35 knock down are consistent with the epithelial-mesenchymal transition, a feature of invasive cancer cells, and we show that Rab35 expression is suppressed in a subset of cancers characterized by Arf6 hyperactivity. Our data thus identify a key molecular mechanism that efficiently coordinates the inverse intracellular sorting and cell surface levels of cadherin and integrin receptors for cell migration and differentiation. Integrin functions are controlled by regulating their affinity for ligand, and by the efficient recycling of intact integrins through endosomes. Here we demonstrate that the Kindlin-binding site in the β1-integrin cytoplasmic domain serves as a molecular switch enabling the sequential binding of two FERM-domain-containing proteins in different cellular compartments. When β1 integrins are at the plasma membrane, Kindlins control ligand-binding affinity. However, when they are internalized, Kindlins dissociate from integrins and sorting nexin 17 (SNX17) is recruited to free β1-integrin tails in early endosomes to prevent β1-integrin degradation, leading to their recycling back to the cell surface. Our results identify SNX17 as a β1-integrin-tail-binding protein that interacts with the free Kindlin-binding site in endosomes to stabilize β1 integrins, resulting in their recycling to the cell surface where they can be reused. Integrins have been implicated in various processes of nervous system development, including proliferation, migration, and differentiation of neuronal cells. In this study, we show that the serine/threonine kinase Ndr2 controls integrin-dependent dendritic and axonal growth in mouse hippocampal neurons. We further demonstrate that Ndr2 is able to induce phosphorylation at the activity- and trafficking-relevant site Thr(788/789) of β1-integrin to stimulate the PKC- and CaMKII-dependent activation of β1-integrins, as well as their exocytosis. Accordingly, Ndr2 associates with integrin-positive early and recycling endosomes in primary hippocampal neurons and the surface expression of activated β1-integrins is reduced on dendrites of Ndr2-deficient neurons. The role of Ndr2 in dendritic differentiation is also evident in vivo, because Ndr2-null mutant mice show arbor-specific alterations of dendritic complexity in the hippocampus. This indicates a role of Ndr2 in the fine regulation of dendritic growth; in fact, treatment of primary neurons with Semaphorin 3A rescues Ndr2 knock-down-induced dendritic growth deficits but fails to enhance growth beyond control level. Correspondingly, Ndr2-null mutant mice show a Semaphorin 3A(-/-)-like phenotype of premature dendritic branching in the hippocampus. The results of this study show that Ndr2-mediated integrin trafficking and activation are crucial for neurite growth and guidance signals during neuronal development. Integrin trafficking plays an important role in cellular motility and cytokinesis. Integrins undergo constant endo/exocytic shuttling to facilitate the dynamic regulation of cell adhesion. Integrin activity toward the components of the extracellular matrix is regulated by the ability of these receptors to switch between active and inactive conformations. Several cellular signalling pathways have been described in the regulation of integrin traffic under different conditions. However, the interrelationship between integrin activity conformations and their endocytic fate have remained incompletely understood. Here, we have investigated the endocytic trafficking of active and inactive β1 integrins in cancer cells. Both conformers are endocytosed in a clathrin- and dynamin-dependent manner. The net endocytosis rate of the active β1 integrins is higher, whereas endocytosis of the inactive β1 integrin is counteracted by rapid recycling back to the plasma membrane via an ARF6- and early endosome antigen 1-positive compartment in an Rab4a- and actin-dependent manner. Owing to these distinct trafficking routes, the two receptor pools display divergent subcellular localization. At steady state, the inactive β1 integrin is mainly on the plasma membrane, whereas the active receptor is predominantly intracellular. These data provide new insights into the endocytic traffic of integrins and imply the possibility of a previously unappreciated crosstalk between pathways regulating integrin activity and traffic. Regulated turnover of integrin receptors is essential for cell adhesion and migration. Pathways selectively regulating β1-integrin recycling are implicated in cancer invasion and metastasis, yet proteins required for the internalization of this pro-invasive integrin remain to be identified. Here, we uncover formin-like 2 (FMNL2) as a critical regulator of β1-integrin internalization downstream of protein kinase C (PKC). PKCα associates with and phosphorylates FMNL2 at S1072 within its Diaphanous autoregulatory region, leading to the release of formin autoinhibition. Phosphorylation of FMNL2 triggers its rapid relocation and promotes its interaction with the cytoplasmic tails of the α-integrin subunits for β1-integrin endocytosis. FMNL2 drives β1-integrin internalization and invasive motility in a phosphorylation-dependent manner, while a FMNL2 mutant defective in actin assembly interferes with β1-integrin endocytosis and cancer cell invasion. Our data establish a role for FMNL2 in the regulation of β1-integrin and provide a mechanistic understanding of the function of FMNL2 in cancer invasiveness. Recycling of internalized integrins is a crucial step in adhesion remodeling and cell movement. Recently, we determined that the ADP-ribosylation factor-guanine nucleotide exchange factors (ARF-GEFs) cytohesin 2/ARNO and cytohesin 3/GRP1 have opposing effects on adhesion and stimulated β1 integrin recycling even though they are very closely related proteins (80% sequence identity). We have now determined the sequence differences underlying the differential actions of cytohesin 2/ARNO and cytohesin 3/GRP1. We found that the ability of cytohesins to promote β1 integrin recycling and adhesion depends upon the presence or absence of a key glycine residue in their pleckstrin homology (PH) domains. This glycine residue determines the phosphoinositide specificity and affinity of cytohesin PH domains. Switching the number of glycines in the PH domains of cytohesin 2 and cytohesin 3 is sufficient to reverse their effects on adhesion and spreading and to reverse their subcellular locations. Importantly, we also find that a mutant form of cytohesin 3/GRP1 that has three rather than two glycines in its PH domain rescues β1 integrin recycling in cytohesin 2/ARNO knockdown cells. Conversely, a mutant form of cytohesin 2/ARNO with two glycines in its PH domain fails to rescue β1 integrin recycling. Therefore, we conclude that phosphoinositide specificity is the sole functional difference that determines which cytohesin can promote integrin recycling. The human plasma membrane sialidase NEU3 is a key enzyme in the catabolism of membrane gangliosides, is crucial in the regulation of cell surface processes, and has been demonstrated to be significantly up-regulated in renal cell carcinomas (RCCs). In this report, we show that NEU3 regulates β1 integrin trafficking in RCC cells by controlling β1 integrin recycling to the plasma membrane and controlling activation of the epidermal growth factor receptor (EGFR) and focal adhesion kinase (FAK)/protein kinase B (AKT) signaling. NEU3 silencing in RCC cells increased the membrane ganglioside content, in particular the GD1a content, and changed the expression of key regulators of the integrin recycling pathway. In addition, NEU3 silencing up-regulated the Ras-related protein RAB25, which directs internalized integrins to lysosomes, and down-regulated the chloride intracellular channel protein 3 (CLIC3), which induces the recycling of internalized integrins to the plasma membrane. In this manner, NEU3 silencing enhanced the caveolar endocytosis of β1 integrin, blocked its recycling and reduced its levels at the plasma membrane, and, consequently, inhibited EGFR and FAK/AKT. These events had the following effects on the behavior of RCC cells: they (a) decreased drug resistance mediated by the block of autophagy and the induction of apoptosis; (b) decreased metastatic potential mediated by down-regulation of the metalloproteinases MMP1 and MMP7; and (c) decreased adhesion to collagen and fibronectin. Therefore, our data identify NEU3 as a key regulator of the β1 integrin-recycling pathway and FAK/AKT signaling and demonstrate its crucial role in RCC malignancy.

Are BBS mutations involved in syndromic Hirschsprung disease?

In 3 families with Bardet-Biedl syndrome (BBS) and Hirschsprung disease (HSCR), concomitant mutations in BBS genes and regulatory RET elements have been identified. Analysis of the data suggests that BBS mutations can potentiate HSCR predisposing RET alleles, which by themselves are insufficient to cause disease.

[19666486]

Hirschsprung disease (HSCR) is a common, multigenic neurocristopathy characterized by incomplete innervation along a variable length of the gut. The pivotal gene in isolated HSCR cases, either sporadic or familial, is RET. HSCR also presents in various syndromes, including Shah-Waardenburg syndrome (WS), Down (DS), and Bardet-Biedl (BBS). Here, we report 3 families with BBS and HSCR with concomitant mutations in BBS genes and regulatory RET elements, whose functionality is tested in physiologically relevant assays. Our data suggest that BBS mutations can potentiate HSCR predisposing RET alleles, which by themselves are insufficient to cause disease. We also demonstrate that these genes interact genetically in vivo to modulate gut innervation, and that this interaction likely occurs through complementary, yet independent, pathways that converge on the same biological process.

Which signaling pathway is activating the dishevelled proteins?

Dishevelled (Xdsh) controls cell fate via canonical Wnt signaling

[15936275, 19561403, 25358879]

The Dishevelled protein mediates several diverse biological processes. Intriguingly, within the same tissues where Xenopus Dishevelled (Xdsh) controls cell fate via canonical Wnt signaling, it also controls cell polarity via the vertebrate planar cell polarity (PCP) cascade [1, 2, 3, 4, 5, 6, 7, 8 and 9]. The relationship between subcellular localization of Dishevelled and its signaling activities remains unclear; conflicting results have been reported depending upon the organism and cell types examined [8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 and 20]. We have approached this issue by developing new reagents to sequester wild-type Dishevelled protein either at the cell membrane or away from the cell membrane. Removal of Dishevelled from the cell membrane disrupts convergent extension by preventing Rho/Rac activation and mediolateral cell polarization. By manipulating the subcellular localization of K-->M (dsh1), we show that this mutation inhibits Dishevelled activation of Rac, regardless of its subcellular localization. These data demonstrate that membrane localization of Dishevelled is a prerequisite for vertebrate PCP signaling. However, both membrane-targeted and cytoplasm-targeted Dishevelled can potently activate canonical Wnt signaling, suggesting that local concentration of Dishevelled protein, but not its spatial localization, is central to canonical Wnt signaling. These results suggest that in vertebrate embryos, subcellular localization is insufficient to account for the pathway specificity of Dishevelled in the canonical Wnt versus PCP signaling cascades. Wnt signaling is known to be important for diverse embryonic and post-natal cellular events and be regulated by the proteins Dishevelled and Axin. Although Dishevelled is activated by Wnt and involved in signal transduction, it is not clear how Dishevelled-mediated signaling is turned off. We report that guanine nucleotide binding protein beta 2 (Gnb2; Gbeta2) bound to Axin and Gbeta2 inhibited Wnt mediated reporter activity. The inhibition involved reduction of the level of Dishevelled, and the Gbeta2gamma2 mediated reduction of Dishevelled was countered by increased expression of Axin. Consistent with these effects in HEK293T cells, injection of Gbeta2gamma2 into Xenopus embryos inhibited the formation of secondary axes induced either by XWnt8 or Dishevelled, but not by beta-catenin. The DEP domain of Dishevelled is necessary for both interaction with Gbeta2gamma2 and subsequent degradation of Dishevelled via the lysosomal pathway. Signaling induced by Gbeta2gamma2 is required because a mutant of Gbeta2, Gbeta2 (W332A) with lower signaling activity, had reduced ability to downregulate the level of Dishevelled. Activation of Wnt signaling by either of two methods, increased Frizzled signaling or transient transfection of Wnt, also led to increased degradation of Dishevelled and the induced Dishevelled loss is dependent on Gbeta1 and Gbeta2. Other studies with agents that interfere with PLC action and calcium signaling suggested that loss of Dishevelled is mediated through the following pathway: Wnt/Frizzled-->Gbetagamma-->PLC-->Ca(+2)/PKC signaling. Together the evidence suggests a novel negative feedback mechanism in which Gbeta2gamma2 inhibits Wnt signaling by degradation of Dishevelled. Dishevelled (DVL) proteins, three of which have been identified in humans, are highly conserved components of canonical and noncanonical Wnt signaling pathways. These multifunctional proteins, originally discovered in the fruit fly, through their different domains mediate complex signal transduction: DIX (dishevelled, axin) and PDZ (postsynaptic density 95, discs large, zonula occludens-1) domains serve for canonical beta-catenin signaling, while PDZ and DEP (dishevelled, Egl-10, pleckstrin) domains serve for non-canonical signaling. In canonical or beta-catenin signaling, DVL forms large molecular supercomplexes at the plasma membrane consisting of Wnt-Fz-LRP5/6-DVL-AXIN. This promotes the disassembly of the beta-catenin destruction machinery, beta-catenin accumulation, and consequent activation of Wnt signaling. Therefore, DVLs are considered to be key regulators that rescue cytoplasmic beta-catenin from degradation. The potential medical importance of DVLs is in both human degenerative disease and cancer. The overexpression of DVL has been shown to potentiate the activation of Wnt signaling and it is now apparent that up-regulation of DVLs is involved in several types of cancer.

Which is the defective protein causing the lysosomal storage disease Fabry?

Anderson-Fabry disease (referred to as Fabry disease) is an X-linked disorder characterized by a deficiency of the lysosomal enzyme alpha-galactosidase A and the subsequent accumulation in various tissues of globotriaosylceramide (Gb(3)), the main substrate of the defective enzyme.

[15702403, 9323559, 9395081, 19146893, 19202000, 15533650]

Human alpha-galactosidase A (EC 3.2.1.22; alpha-Gal A) is the lysosomal exoglycosidase responsible for the hydrolysis of terminal alpha-galactosyl residues from glycoconjugates and is the defective enzyme causing Fabry disease (McKusick 301500). An unusally elevated level of plasma alpha-Gal A activity (> 2.5 times the normal mean) was detected in two unrelated normal males and the elevated activities were inherited as X-linked traits in their families. Sequencing of the alpha-Gal A coding region, intron/exon boundaries and 5'-flanking region from the proband identified a single mutation, a G-->A transition 30 nt upstream from the initiation of translation codon in exon 1. The -30G-->A mutation occurred in a putative NF kappa B/Ets consensus binding site that was recently shown to inhibit protein binding to the 5'-untranslated region of the gene, providing a possible explanation for its high activity. To further characterize the mutation, the mRNA and protein expressed by this variant allele were studied. Purified plasma and lymphoblast alpha-Gal A activity from individuals with the -30G-->A mutation had normal physical and kinetic properties. In vitro translation of mRNAs from the cloned normal and high plasma activity alleles resulted in similar levels of alpha-Gal A protein, indicating that this mutation did not enhance translation. These findings suggest that the -30G-->A mutation in the 5'-untranslated region of the alpha-Gal A gene enhances transcription, presumably by interfering with the binding of negatively-acting transcription factors which normally decrease alpha-Gal A expression in various cells. Preliminary studies of the frequency of the -30G-->A mutation in 395 unrelated normal males of mixed ancestry revealed two additional unrelated individuals who had high plasma enzymatic activity and the mutation, confirming the effect of this mutation on enzyme expression and suggesting that about 0.5% of normal individuals have high plasma alpha-Gal A activity due to this variant allele. Transgenic mice expressing a human mutant alpha-galactosidase with an R301Q substitution, which was found in a patient with a variant form of Fabry disease, were established. The mice transcribed a sufficient amount of alpha-galactosidase mRNA, but the steady-state levels of the enzyme protein were decreased in liver, kidney and heart, only residual activity being detected in these tissues. The mice will be useful for the clarification of the defective regulation of the structurally altered enzyme protein expressed by the mutant gene at the organ or individual level as well as for the evaluation of drugs that stabilize and/or activate the mutant alpha-galactosidase. Lysosomal storage diseases arise from a genetic loss-of-function defect in enzymes mediating key catabolic steps resulting in accumulation of substrate within the lysosome. Treatment of several of these disorders has been achieved by enzyme replacement therapy (ERT), in which a recombinant version of the defective enzyme is expressed in vitro and administered by infusion. However, in many cases the biodistribution of the administered protein does not match that of the accumulated substrate due to the glycosylation-mediated clearance of the enzymes from circulation, resulting in poor or absent substrate clearance from some tissues. To overcome this limitation, we have evaluated several peptide-based targeting motifs to redirect recombinant human alpha-galactosidase (rhalphaGal) to specific receptors. A reversible thiol-based PEGylation chemistry was developed to achieve multivalent peptide display with lysosomal release. In vitro, cell uptake was peptide dependent and independent of the normal mannose-6-phosphate receptor mediated pathway. Surprisingly, despite increased plasma half-life and decreased liver uptake, none of the peptide conjugates showed significantly altered biodistribution in alphaGal-knockout mice. This suggests that these peptide-based targeting motifs are unlikely to provide substantial therapeutic benefit likely due to the complexity of factors affecting PK and biodistribution. The lysosomal storage disorder Fabry disease is characterized by excessive globotriaosylceramide (Gb3) accumulation in major organs such as the heart and kidney. Defective lysosomal alpha-galactosidase A (Gla) is responsible for excessive Gb3 accumulation, and one cell sensitive to the effects of Gb3 accumulation is vascular endothelium. Endothelial dysfunction is associated with Fabry disease and excessive cellular Gb3. We previously demonstrated that excessive vascular Gb3 in a mouse model of Fabry disease, the Gla-knockout (Gla(-/0)) mouse, results in abnormal vascular function, which includes abnormal endothelium-dependent contractions, a vascular phenomenon known to involve cyclooxygenase (COX). Therefore, we hypothesized that the vasculopathy in the Gla knockout mouse may be due to a vasoactive COX-derived product. To test this hypothesis, vascular reactivity experiments were performed in aortic rings from wild-type (Gla(+/0)) and Gla(-/0) mice in the presence and absence of specific and nonspecific COX inhibitors. Specific inhibition of COX1 or COX2 in endothelium-intact rings from Gla(-/0) mice decreased overall phenylephrine contractility compared with untreated Gla(-/0) rings, whereas COX inhibitors had no effect on contractility in endothelium-denuded rings. Nonspecific inhibition of COX with indomethacin (10 micromol/l) or COX1 inhibition with valeryl salicylate (3 mmol/l) improved endothelial function in rings from Gla(-/0) mice, but COX2 inhibition with NS-398 (1 micromol/l) further increased endothelial dysfunction in rings from Gla(-/0) mice. These results suggest that, in the Gla(-/0) mice, COX1 and COX2 activity are increased and localized in the endothelium, producing vasopressor and vasorelaxant products, which contribute to the Fabry-related vasculopathy. Sphingolipidoses are a subgroup of lysosomal storage diseases. They are defined as disorders caused by a genetic defect in catabolism of sphingosine-containing lipids. Catabolism of these lipids involves enzymes and activator proteins. After the discovery of lysosomes by de Duve and the demonstration of the first defective lysosomal enzyme by Hers in 1963, the first enzyme deficiency for sphingolipidoses was characterized in 1965 and all the defective enzymes were demonstrated in the last three decades. In 1984, the first activator protein was found and it expanded the concept of sphingolipidoses. In the following years, many researches have been undertaken to understand the molecular basis of these diseases, the mechanism of pathogenesis, the mechanism of lysosomal digestion of glycosphingolipids (GSLs) and the functional domains of lysosomal enzymes. New hypotheses and theories have been put forward for the mechanism of lysosomal digestion and pathogenesis. However, although much has been done, the pathogenesis of sphingolipidoses has not been fully elucidated. Mouse models of these diseases have facilitated the elucidation of pathogenesis and the development of therapeutic strategies for these diseases, which are not treatable at present except for Fabry and type 1 Gaucher disease. The purpose of this review is to collect information on the recent researches related to sphingolipidoses. The review includes the hydrolysis of GSLs in lysosome, mechanism of hydrolysis, pathogenesis and genetics of sphingolipidoses, a brief mouse model and therapeutic strategies of these diseases.

Is there any software for automated analysis of immuno-histochemistry images?

In some studies of breast cancer, quantitation of immunohistochemically highlighted microvessel ‘hot spots’ has been shown to be a powerful prognostic tool. However, the antibody used, the number and size of the ‘hot spots’ assessed, and the stratification of patients into high and low vascular groups vary between studies. Furthermore, little is known about the relationship between microvessel density and other vascular parameters. These uncertainties and the laborious nature of the technique make it unsuitable for diagnostic practice. Both manual and computerized image analysis techniques were used in this study to examine the relationship between microvessel density and the vascular parameters in different sized microscopic fields in a pilot series of 30 invasive breast carcinomas. Automated pixel analysis of immunohistochemical staining, Chalkley point counting, and observer subjective vascular grading were also assessed as more rapid methods of measuring tumour vascularity

[24262147, 20588996, 22114700, 23586030, 24003130, 23625497, 20663194, 21818782]

LIM homeodomain transcription factors are critical regulators of early development in multiple systems but have yet to be examined for a role in circuit formation. The LIM homeobox gene Lhx2 is expressed in cortical progenitors during development and also in the superficial layers of the neocortex in maturity. However, analysis of Lhx2 function at later stages of cortical development has been hampered by severe phenotypes associated with early loss of function. We identified a particular Cre-recombinase line that acts in the cortical primordium after its specification is complete, permitting an analysis of Lhx2 function in neocortical lamination, regionalization, and circuit formation by selective elimination of Lhx2 in the dorsal telencephalon. We report a profound disruption of cortical neuroanatomical and molecular features upon loss of Lhx2 in the cortex from embryonic day 11.5. A unique feature of cortical circuitry, the somatosensory barrels, is undetectable, and molecular patterning of cortical regions appears disrupted. Surprisingly, thalamocortical afferents innervate the mutant cortex with apparently normal regional specificity. Electrophysiological recordings reveal a loss of responses evoked by stimulation of individual whiskers, but responses to simultaneous stimulation of multiple whiskers were present, suggesting that thalamic afferents are unable to organize the neurocircuitry for barrel formation because of a cortex-specific requirement of Lhx2. We report that Lhx2 is required for the expression of transcription factor paired box gene 6, axon guidance molecule Ephrin A5, and the receptor NMDA receptor 1. These genes may mediate Lhx2 function in the formation of specialized neurocircuitry necessary for neocortical function. PURPOSE: To develop a fully automated algorithm (AP) to perform a volumetric measure of the optic disc using conventional stereoscopic optic nerve head (ONH) photographs, and to compare algorithm-produced parameters with manual photogrammetry (MP), scanning laser ophthalmoscope (SLO) and optical coherence tomography (OCT) measurements. METHODS: One hundred twenty-two stereoscopic optic disc photographs (61 subjects) were analyzed. Disc area, rim area, cup area, cup/disc area ratio, vertical cup/disc ratio, rim volume and cup volume were automatically computed by the algorithm. Latent variable measurement error models were used to assess measurement reproducibility for the four techniques. RESULTS: AP had better reproducibility for disc area and cup volume and worse reproducibility for cup/disc area ratio and vertical cup/disc ratio, when the measurements were compared to the MP, SLO and OCT methods. CONCLUSION: AP provides a useful technique for an objective quantitative assessment of 3D ONH structures. The basal ganglia are critical for selecting actions and evaluating their outcome. Although the circuitry for selection is well understood, how these nuclei evaluate the outcome of actions is unknown. Here, we show in lamprey that a separate evaluation circuit, which regulates the habenula-projecting globus pallidus (GPh) neurons, exists within the basal ganglia. The GPh neurons are glutamatergic and can drive the activity of the lateral habenula, which, in turn, provides an indirect inhibitory influence on midbrain dopamine neurons. We show that GPh neurons receive inhibitory input from the striosomal compartment of the striatum. The striosomal input can reduce the excitatory drive to the lateral habenula and, consequently, decrease the inhibition onto the dopaminergic system. Dopaminergic neurons, in turn, provide feedback that inhibits the GPh. In addition, GPh neurons receive direct projections from the pallium (cortex in mammals), which can increase the GPh activity to drive the lateral habenula to increase the inhibition of the neuromodulatory systems. This circuitry, thus, differs markedly from the "direct" and "indirect" pathways that regulate the pallidal (e.g., globus pallidus) output nuclei involved in the control of motion. Our results show that a distinct reward-evaluation circuit exists within the basal ganglia, in parallel to the direct and indirect pathways, which select actions. Our results suggest that these circuits are part of the fundamental blueprint that all vertebrates use to select actions and evaluate their outcome. Zebrafish have emerged as a powerful model organism to study embryo morphogenesis. Due to their optical clarity, they are uniquely suited for time-lapse imaging studies, providing insights into the dynamic processes underlying tissue formation and cell migration. These studies have been tremendously facilitated by the availability of transgenic zebrafish lines, labelling distinct embryonic structures, individual cells, or even subcellular structures, such as the nucleus. Zebrafish studies have revealed that the migration of several different cell types in the embryo is controlled by chemokines, small vertebrate-specific proteins. Here, we report methods to analyze the expression pattern of a given chemokine and its receptor in transgenic zebrafish using fluorescent in situ hybridization in combination with an anti-green fluorescent protein (GFP) antibody staining. We furthermore illustrate how to image migrating cell populations using time-lapse microscopy in double-transgenic embryos. We show how to investigate cell number and direction of migration by using a nuclear-localized GFP. The combination of this transgene with a membrane-targeted red fluorescent protein allows for the simultaneous determination of changes in cell shape, such as the formation of filopodial extensions. We exemplify this by describing how a mutation in the chemokine receptor cxcr4a affects endothelial cell migration and blood vessel formation. Finally, we provide a method to perform fluorescent angiography to monitor blood vessel perfusion in chemokine receptor mutants. INTRODUCTION: Accurate assessment of estrogen receptor (ER), progesterone receptor (PR), and Ki-67 is essential in the histopathologic diagnostics of breast cancer. Commercially available image analysis systems are usually bundled with dedicated analysis hardware and, to our knowledge, no easily installable, free software for immunostained slide scoring has been described. In this study, we describe a free, Internet-based web application for quantitative image analysis of ER, PR, and Ki-67 immunohistochemistry in breast cancer tissue sections. METHODS: The application, named ImmunoRatio, calculates the percentage of positively stained nuclear area (labeling index) by using a color deconvolution algorithm for separating the staining components (diaminobenzidine and hematoxylin) and adaptive thresholding for nuclear area segmentation. ImmunoRatio was calibrated using cell counts defined visually as the gold standard (training set, n = 50). Validation was done using a separate set of 50 ER, PR, and Ki-67 stained slides (test set, n = 50). In addition, Ki-67 labeling indexes determined by ImmunoRatio were studied for their prognostic value in a retrospective cohort of 123 breast cancer patients. RESULTS: The labeling indexes by calibrated ImmunoRatio analyses correlated well with those defined visually in the test set (correlation coefficient r = 0.98). Using the median Ki-67 labeling index (20%) as a cutoff, a hazard ratio of 2.2 was obtained in the survival analysis (n = 123, P = 0.01). ImmunoRatio was shown to adapt to various staining protocols, microscope setups, digital camera models, and image acquisition settings. The application can be used directly with web browsers running on modern operating systems (e.g., Microsoft Windows, Linux distributions, and Mac OS). No software downloads or installations are required. ImmunoRatio is open source software, and the web application is publicly accessible on our website. CONCLUSIONS: We anticipate that free web applications, such as ImmunoRatio, will make the quantitative image analysis of ER, PR, and Ki-67 easy and straightforward in the diagnostic assessment of breast cancer specimens. During normal brain development, axons are myelinated by mature oligodendrocytes (OLGs). Under pathological, demyelinating conditions within the central nervous system (CNS), axonal remyelination is only partially successful because oligodendrocyte precursor cells (OPCs) largely remain in an undifferentiated state resulting in a failure to generate myelinating OLGs. Tissue Transglutaminase (TG2) is a multifunctional enzyme, which amongst other functions, is involved in cell differentiation. Therefore, we hypothesized that TG2 contributes to differentiation of OPCs into OLGs and thereby stimulates remyelination. In vivo studies, using the cuprizone model for de- and remyelination in TG2(-/-) and wild-type mice, showed that during remyelination expression of proteolipid protein mRNA, as a marker for remyelination, in the corpus callosum lags behind in TG2(-/-) mice resulting in less myelin formation and, moreover, impaired recovery of motor behavior. Subsequent in vitro studies showed that rat OPCs express TG2 protein and activity which reduces when the cells have matured into OLGs. Furthermore, when TG2 activity is pharmacologically inhibited, the differentiation of OPCs into myelin-forming OLGs is dramatically reduced. We conclude that TG2 plays a prominent role in remyelination of the CNS, probably through stimulating OPC differentiation into myelin-forming OLGs. Therefore, manipulating TG2 activity may represent an interesting new target for remyelination in demyelinating diseases.

Is TALEN being used on stem cells?

Yes, TALEN is being used on stem cells for genome editing.

[25047178, 21738127, 23246482, 23928856, 24305178, 24691488, 25245091, 24319658, 26052525, 25414332, 25434822, 24996167, 22749015, 23945944, 23666012, 24155235, 24206569, 25408877, 23921522]

TALEN is one of the most widely used tools in the field of genome editing. It enables gene integration and gene inactivation in a highly efficient and specific fashion. Although very attractive, the apparent simplicity and high success rate of TALEN could be misleading for novices in the field of gene editing. Depending on the application, specific TALEN designs, activity assessments and screening strategies need to be adopted. Here we report different methods to efficiently perform TALEN-mediated gene integration and inactivation in different mammalian cell systems including induced pluripotent stem cells and delineate experimental examples associated with these approaches. Transcription activator-like effector nucleases (TALENs) are a new class of engineered nucleases that are easier to design to cleave at desired sites in a genome than previous types of nucleases. We report here the use of TALENs to rapidly and efficiently generate mutant alleles of 15 genes in cultured somatic cells or human pluripotent stem cells, the latter for which we differentiated both the targeted lines and isogenic control lines into various metabolic cell types. We demonstrate cell-autonomous phenotypes directly linked to disease-dyslipidemia, insulin resistance, hypoglycemia, lipodystrophy, motor-neuron death, and hepatitis C infection. We found little evidence of TALEN off-target effects, but each clonal line nevertheless harbors a significant number of unique mutations. Given the speed and ease with which we were able to derive and characterize these cell lines, we anticipate TALEN-mediated genome editing of human cells becoming a mainstay for the investigation of human biology and disease. Sickle cell disease (SCD) is the most common human genetic disease which is caused by a single mutation of human β-globin (HBB) gene. The lack of long-term treatment makes the development of reliable cell and gene therapies highly desirable. Disease-specific patient-derived human induced pluripotent stem cells (hiPSCs) have great potential for developing novel cell and gene therapies. With the disease-causing mutations corrected in situ, patient-derived hiPSCs can restore normal cell functions and serve as a renewable autologous cell source for the treatment of genetic disorders. Here we successfully utilized transcription activator-like effector nucleases (TALENs), a recently emerged novel genome editing tool, to correct the SCD mutation in patient-derived hiPSCs. The TALENs we have engineered are highly specific and generate minimal off-target effects. In combination with piggyBac transposon, TALEN-mediated gene targeting leaves no residual ectopic sequences at the site of correction and the corrected hiPSCs retain full pluripotency and a normal karyotype. Our study demonstrates an important first step of using TALENs for the treatment of genetic diseases such as SCD, which represents a significant advance toward hiPSC-based cell and gene therapies. The establishment of embryonic stem cells (ESCs) and gene targeting technologies in mice has revolutionised the field of genetics. The relative ease with which genes can be knocked out, and exogenous sequences introduced, has allowed the mouse to become the prime model for deciphering the genetic code. Not surprisingly, the lack of authentic ESCs has hampered the livestock genetics field and has forced animal scientists into adapting alternative technologies for genetic engineering. The recent discovery of the creation of induced pluripotent stem cells (iPSCs) by upregulation of a handful of reprogramming genes has offered renewed enthusiasm to animal geneticists. However, much like ESCs, establishing authentic iPSCs from the domestic animals is still beset with problems, including (but not limited to) the persistent expression of reprogramming genes and the lack of proven potential for differentiation into target cell types both in vitro and in vivo. Site-specific nucleases comprised of zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and clustered regulated interspaced short palindromic repeats (CRISPRs) emerged as powerful genetic tools for precisely editing the genome, usurping the need for ESC-based genetic modifications even in the mouse. In this article, in the aftermath of these powerful genome editing technologies, the role of pluripotent stem cells in livestock genetics is discussed. The development of human embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) facilitates in vitro studies of human disease mechanisms, speeds up the process of drug screening, and raises the feasibility of using cell replacement therapy in clinics. However, the study of genotype-phenotype relationships in ESCs or iPSCs is hampered by the low efficiency of site-specific gene editing. Transcription activator-like effector nucleases (TALENs) spurred interest due to the ease of assembly, high efficiency and faithful gene targeting. In this study, we optimized the TALEN design to maximize its genomic cutting efficiency. We showed that using optimized TALENs in conjunction with single-strand oligodeoxynucleotide (ssODN) allowed efficient gene editing in human cells. Gene mutations and gene deletions for up to 7.8 kb can be accomplished at high efficiencies. We established human tumor cell lines and H9 ESC lines with homozygous deletion of the microRNA-21 (miR-21) gene and miR-9-2 gene. These cell lines provide a robust platform to dissect the roles these genes play during cell differentiation and tumorigenesis. We also observed that the endogenous homologous chromosome can serve as a donor template for gene editing. Overall, our studies demonstrate the versatility of using ssODN and TALEN to establish genetically modified cells for research and therapeutic application. Generation and precise genetic correction of patient-derived hiPSCs have great potential in regenerative medicine. Such targeted genetic manipulations can now be achieved using gene-editing nucleases. Here, we report generation of cystic fibrosis (CF) and Gaucher's disease (GD) hiPSCs respectively from CF (homozygous for CFTRΔF508 mutation) and Type II GD [homozygous for β-glucocerebrosidase (GBA) 1448T>C mutation] patient fibroblasts, using CCR5- specific TALENs. Site-specific addition of loxP-flanked Oct4/Sox2/Klf4/Lin28/Nanog/eGFP gene cassette at the endogenous CCR5 site of patient-derived disease-specific primary fibroblasts induced reprogramming, giving rise to both monoallele (heterozygous) and biallele CCR5-modified hiPSCs. Subsequent excision of the donor cassette was done by treating CCR5-modified CF and GD hiPSCs with Cre. We also demonstrate site-specific correction of sickle cell disease (SCD) mutations at the endogenous HBB locus of patient-specific hiPSCs [TNC1 line that is homozygous for mutated β- globin alleles (βS/βS)], using HBB-specific TALENs. SCD-corrected hiPSC lines showed gene conversion of the mutated βS to the wild-type βA in one of the HBB alleles, while the other allele remained a mutant phenotype. After excision of the loxP-flanked DNA cassette from the SCD-corrected hiPSC lines using Cre, we obtained secondary heterozygous βS/βA hiPSCs, which express the wild-type (βA) transcript to 30-40% level as compared to uncorrected (βS/βS) SCD hiPSCs when differentiated into erythroid cells. Furthermore, we also show that TALEN-mediated generation and genetic correction of disease-specific hiPSCs did not induce any off-target mutations at closely related sites. MicroRNAs are important gene regulators involved in many biological processes, including stemness maintenance and cellular reprogramming. Current methods used in loss-of-function studies of microRNAs mainly include locked nucleic acid (LNA) oligonucleotides and miRZip inhibitors, which have several limitations. Due to their unique gene structures and small sizes, there is no efficient or simple strategy to knock down or knock out microRNAs or whole microRNA clusters. Here, we demonstrate knockdown of the miR-302/367 cluster by using the Kruppel-associated box repressor domain fused with specific transcription activator-like effectors (TALEs) designed to bind the miR-302/367 cluster promoter. We also designed two pairs of TALE nucleases (TALENs) to efficiently delete the miR-302/367 cluster in primary human fibroblasts and determined that knockout of the miR-302/367 cluster completely blocked induced pluripotent stem cell (iPSC) generation. Together, our results demonstrate that TALE-based transcriptional repressor and TALENs are two promising approaches for loss-of-function studies of microRNA clusters in somatic cells and pluripotent stem cells. Duchenne muscular dystrophy (DMD) is a severe muscle-degenerative disease caused by a mutation in the dystrophin gene. Genetic correction of patient-derived induced pluripotent stem cells (iPSCs) by TALENs or CRISPR-Cas9 holds promise for DMD gene therapy; however, the safety of such nuclease treatment must be determined. Using a unique k-mer database, we systematically identified a unique target region that reduces off-target sites. To restore the dystrophin protein, we performed three correction methods (exon skipping, frameshifting, and exon knockin) in DMD-patient-derived iPSCs, and found that exon knockin was the most effective approach. We further investigated the genomic integrity by karyotyping, copy number variation array, and exome sequencing to identify clones with a minimal mutation load. Finally, we differentiated the corrected iPSCs toward skeletal muscle cells and successfully detected the expression of full-length dystrophin protein. These results provide an important framework for developing iPSC-based gene therapy for genetic disorders using programmable nucleases. The rat is the preferred animal model in many areas of biomedical research and drug development. Genetic manipulation in rats has lagged behind that in mice due to the lack of efficient gene targeting tools. Previously, we generated a knockout rat via conventional homologous recombination in rat embryonic stem (ES) cells. Here, we show that efficient gene targeting in rat ES cells can be achieved quickly through transcription activator-like effector nuclease (TALEN)-mediated DNA double-strand breaks. Using the Golden Gate cloning technique, we constructed a pair of TALEN targeting vectors for the gene of interest in 5 days. After gene transfection, the targeted rat ES cell colonies were isolated, screened, and confirmed by PCR without the need of drug selection. Our results suggest that TALEN-mediated gene targeting is a superior means of establishing genetically modified rat ES cell lines with high efficiency and short turnaround time. Safety and reliability of transgene integration in human genome continue to pose challenges for stem cell-based gene therapy. Here, we report a baculovirus-transcription activator-like effector nuclease system for AAVS1 locus-directed homologous recombination in human induced pluripotent stem cells (iPSCs). This viral system, when optimized in human U87 cells, provided a targeted integration efficiency of 95.21% in incorporating a Neo-eGFP cassette and was able to mediate integration of DNA insert up to 13.5 kb. In iPSCs, targeted integration with persistent transgene expression was achieved without compromising genomic stability. The modified iPSCs continued to express stem cell pluripotency markers and maintained the ability to differentiate into three germ lineages in derived embryoid bodies. Using a baculovirus-Cre/LoxP system in the iPSCs, the Neo-eGFP cassette at the AAVS1 locus could be replaced by a Hygro-mCherry cassette, demonstrating the feasibility of cassette exchange. Moreover, as assessed by measuring γ-H2AX expression levels, genome toxicity associated with chromosomal double-strand breaks was not detectable after transduction with moderate doses of baculoviral vectors expressing transcription activator-like effector nucleases. Given high targeted integration efficiency, flexibility in transgene exchange and low genome toxicity, our baculoviral transduction-based approach offers great potential and attractive option for precise genetic manipulation in human pluripotent stem cells. The functional study of Y chromosome genes has been hindered by a lack of mouse models with specific Y chromosome mutations. We used transcription activator-like effector nuclease (TALEN)-mediated gene editing in mouse embryonic stem cells (mESCs) to produce mice with targeted gene disruptions and insertions in two Y-linked genes--Sry and Uty. TALEN-mediated gene editing is a useful tool for dissecting the biology of the Y chromosome. β-Thalassemia (β-Thal) is a group of life-threatening blood disorders caused by either point mutations or deletions of nucleotides in β-globin gene (HBB). It is estimated that 4.5% of the population in the world carry β-Thal mutants (1), posing a persistent threat to public health. The generation of patient-specific induced pluripotent stem cells (iPSCs) and subsequent correction of the disease-causing mutations offer an ideal therapeutic solution to this problem. However, homologous recombination-based gene correction in human iPSCs remains largely inefficient. Here, we describe a robust process combining efficient generation of integration-free β-Thal iPSCs from the cells of patients and transcription activator-like effector nuclease (TALEN)-based universal correction of HBB mutations in situ. We generated integration-free and gene-corrected iPSC lines from two patients carrying different types of homozygous mutations and showed that these iPSCs are pluripotent and have normal karyotype. We showed that the correction process did not generate TALEN-induced off targeting mutations by sequencing. More importantly, the gene-corrected β-Thal iPS cell lines from each patient can be induced to differentiate into hematopoietic progenitor cells and then further to erythroblasts expressing normal β-globin. Our studies provide an efficient and universal strategy to correct different types of β-globin mutations in β-Thal iPSCs for disease modeling and applications. BACKGROUND: Transcription activator-like effector nucleases (TALENs) have emerged as a tool for enabling targeted gene editing and disruption in difficult systems, such as human pluripotent stem cells (hPSCs). The modular architecture of TAL effectors theoretically enables targeting of any genomic locus and several cloning systems for custom TALEN assembly have recently been established. However, there is a lack of versatile TALEN expression systems applicable to hPSCs. RESULTS: Here, we extend an existing TALE assembly system by a dual set of expression vectors for efficient application of TALEN technology in hPSCs. This is characterized by improved TALEN architecture as well as antibiotic resistance and fluorescent reporter cassettes, thus enabling enrichment for transfected cells. Improved functionality of the combined system was demonstrated by targeted disruption of the HPRT1 gene to create isogenic disease models of Lesch-Nyhan-Syndrome. Using female hPSCs, homozygous disruption of HPRT1 occurred at efficiencies of up to 15%. Differentiating isogenic knock-out cells both into central nervous system (CNS) as well as into sensory-like neurons recapitulated previously described phenotypes based on patient-specific induced PSCs and extended these findings to non-CNS neurons, respectively. CONCLUSION: The combined vector system allows for flexible and affordable generation of knock-out hPSCs lines, thus enabling investigation of developmental processes as well as the generation of isogenic disease models without the need for patient material. Our ability to precisely and efficiently edit mammalian and plant genomes has been significantly improved in recent years, partially due to increasing use of designer nucleases that recognize a pre-determined DNA sequence, make a specific DNA double-strand break, and stimulate gene targeting. A pair of zinc finger nucleases (ZFNs) or transcription activator-like effector nucleases (TALENs) that recognize two adjacent unique DNA sequences dimerize through the fused FokI nuclease domain and cut in the middle of target DNA sequences. We report here that increasing the length of recognition DNA sequences by TALENs or ZFNs does not necessarily translate to a higher efficiency or specificity. We also discover that one subunit of ZFNs and one subunit of TALENs can form a pair of hybrid nucleases with expanded specificity at two diverse targets, and stimulate gene targeting in multiple cell types including human induced pluripotent stem (iPS) cells with improved efficiency.

Is there an association between bruxism and reflux

There is an association between bruxism and reflux.

[19089153, 21248360, 23937680, 23738993, 14655925, 15520695, 24011800, 19830044]

Bruxism is a pathological activity of the stomatognathic system that involves tooth grinding and clenching during parafunctional jaw movements. Clinical signs of bruxism are mostly related to dental wear and muscular and joint discomforts, but a large number of etiological factors can be listed, as local, systemic, psychological and hereditary factors. The association between bruxism, feeding and smoking habits and digestive disorders may lead to serious consequences to dental and related structures, involving dental alterations (wear, fractures and cracks), periodontal signs (gingival recession and tooth mobility) and muscle-joint sensitivity, demanding a multidisciplinary treatment plan. This paper presents a case report in which bruxism associated with acid feeding, smoking habit and episodes of gastric reflow caused severe tooth wear and great muscular discomfort with daily headache episodes. From the diagnosis, a multidisciplinary treatment plan was established. The initial treatment approach consisted of medical follow up with counseling on diet and smoking habits and management of the gastric disorders. This was followed by the installation of an interocclusal acrylic device in centric relation of occlusion (CRO) for reestablishment of the occlusal stability, vertical dimension of occlusion, anterior guides and return to normal muscle activity (90-day use approximately). After remission of initial symptoms, oral rehabilitation was implemented in CRO by means of full resin composite restorations and new interocclusal device for protection of restorations. Satisfactory esthetics, improved function and occlusal stability were obtained after oral rehabilitation. The patient has attended annual follow-ups for the past 2 years. The multidisciplinary treatment seems to be the key for a successful rehabilitation of severe cases of dental wear involving the association of different health disorders. The aim of this cross-over, randomized, single-blinded trial was to examine whether intra-esophageal acidification induces sleep bruxism (SB). Polysomnography with electromyogram (EMG) of masseter muscle, audio-video recording, and esophageal pH monitoring were performed in a sleep laboratory. Twelve healthy adult males without SB participated. Intra-esophageal infusions of 5-mL acidic solution (0.1 N HCl) or saline were administered. The frequencies of EMG bursts, rhythmic masticatory muscle activity (RMMA) episodes, grinding noise, and the RMMA/microarousal ratio were significantly higher in the 20-minute period after acidic infusion than after saline infusion. RMMA episodes including SB were induced by esophageal acidification. This trial is registered with the UMIN Clinical Trials Registry, UMIN000002923. ABBREVIATIONS: ASDA, American Sleep Disorders Association; EMG, electromyogram; GER, gastroesophageal reflux; LES, lower esophageal sphincter; NREM, non-rapid eye movement; REM, rapid eye movement; RMMA, rhythmic masticatory muscle activity; SB, sleep bruxism; SD, standard deviation; UES, upper esophageal sphincter. BACKGROUND: There are few large-scale epidemiologic studies examining the associations between sleep problems, gastroesophageal reflux disease (GERD) symptoms, lifestyle and food habits and problem behaviors (PB) in adolescents. The aim of this study was to evaluate the associations among these factors in Japanese adolescents. METHODS: A cross-sectional survey of 1840 junior high school students was carried out using questionnaires. The subjects were classified into PB or normal behavior (NB) groups using the Pediatric Symptom Checklist (PSC). The scores of the sleep-related factors, sleep bruxism, lifestyle and food habits, and GERD symptoms were compared. Logistic regression analysis was used to determine the factors related to PB. RESULTS: Mean subject age was 13.3 ± 1.8 years. The PB group had significantly longer sleep latency and higher GERD symptom score (P < 0.001). Furthermore, the PB group was significantly more likely to experience absence of the mother at dinner time, skip breakfast, and have <30 min of conversation among family at dinner time. The PB group had significantly higher frequencies of sleep bruxism, difficulty falling asleep within 30 min, nightmares, feeling of low sleep quality, daytime somnolence, and daytime lack of motivation. Feelings of low sleep quality had the strongest association with PB, with an adjusted odds ratio of 12.88 (95% confidence interval: 8.99-18.46). CONCLUSIONS: PB in adolescents are associated with sleep problems, including sleep bruxism, as well as lifestyle and food habits and GERD symptoms. Gastroesophageal reflux disease (GERD) is a gastrointestinal disorder in which stomach acids are chronically regurgitated into the esophagus and oral cavity. Continual exposure of the teeth to these acids can cause severe tooth wear. Dentists are often the first healthcare professionals to diagnose dental erosion in patients with GERD. This article presents a case report of a 27-year-old male smoker with tooth wear and dentin sensitivity caused by GERD associated with bruxism. After diagnosis, a multidisciplinary treatment plan was established. The initial treatment approach consisted of medical follow-up with counseling on dietary and smoking habits, as well as management of the gastric disorders with medication. GERD management and the dental treatment performed for the eroded dentition are described, including diagnosis, treatment planning, and restorative therapy. The purpose of this study was to examine the relationships among nocturnal jaw muscle activities, decreased esophageal pH, and sleep positions. Twelve adult volunteers, including 4 bruxism patients, participated in this study. Portable pH monitoring, electromyography of the temporal muscle, and audio-video recordings were conducted during the night in the subjects' homes. Rhythmic masticatory muscle activity (RMMA) episodes were observed most frequently, with single short-burst episodes the second most frequent. The frequencies of RMMA, single short-burst, and clenching episodes were significantly higher during decreased esophageal pH episodes than those during other times. Both the electromyography and the decreased esophageal pH episodes were most frequently observed in the supine position. These results suggest that most jaw muscle activities, ie, RMMA, single short-burst, and clenching episodes, occur in relation to gastroesophageal reflux mainly in the supine position. STATEMENT OF PROBLEM: Rhythmic masticatory muscle activity, including sleep bruxism (SB), can be induced in healthy individuals by experimental esophageal acidification, which plays an important role in the pathogenesis of gastroesophageal reflux disease (GERD). However, no robust evidence supports the association between SB and GERD. PURPOSE: The purpose of this study was to investigate the association between SB and GERD. MATERIAL AND METHODS: Forty-five individuals were eligible to participate in this observational transversal study at the Gastroenterology Service of the Clinical Hospital of Porto Alegre, Brazil. The participants were classified into 2 groups, those with and without GERD, according to the Montreal Criteria and pH-metry/endoscopy findings. The diagnosis of SB was not assessed in a sleep laboratory but was based on self-report plus clinical inspection, according to the minimal diagnostic criteria of the American Academy of Sleep Medicine. The Lipp Stress Symptom Inventory was used to evaluate self-perceived stress. Univariate and multiple logistic regression analyses were performed with SB as dependent variable and GERD, sex, age, body mass index, and stress as predictors (α=.05; 90% power). RESULTS: The study population included individuals with SB without GERD (13.3%) and individuals with SB with GERD (31.1%). In participants with GERD, the prevalence of SB was 73.7%. Only the variable GERD was significantly associated with SB (P=.017; odds ratio 6.58; 95% confidence interval 1.40-30.98), although adjusted for stress and age. CONCLUSIONS: Sleep bruxism is prevalent in GERD patients, and GERD is highly associated with SB. INTRODUCTION: Chronic regurgitation of gastric acids in patients with gastroesophageal reflux disease may cause dental erosion, which can lead in combination with attrition or bruxism to extensive loss of coronal tooth tissue. CASE PRESENTATION: This clinical report describes treatment of severe tooth wear of a gastroesophageal reflux disease patient who is 54-year-old Turkish male patient. After his medical treatment, severe tooth wear, bruxism and decreased vertical dimensions were determined. The vertical dimension was re-established and maxillary and mandibular anterior and posterior teeth were prepared for metal-ceramic restorations. Metal-ceramic fixed partial dentures were fabricated as full mouth restorations for both maxillary and mandibular arches because of splinting all teeth. And then maxillary stabilization splint was fabricated for his bruxism history. CONCLUSION: Significant loss of coronal tooth structure must taken into consideration. Gastroesophageal reflux disease by itself or in combination with attrition, abrasion or bruxism may be responsible for the loss. An extensive diagnostic evaluation is essential for the medical and dental effects of the problem.

what is the role of IGF-1 in cardiac regeneration after myocardial infarction?

Ischemia-reperfusion injury is a strong stimulus for both global and focal cardiomyocyte progenitor cell marker up-regulations, correlating to the endogenous up-regulation of IGF-1. Furthermore, in an animal model of myocardial infarction, intracoronary administration of IGF-1 is shown to reduce pathological cardiac remodeling, induce myocardial regeneration, and improve ventricular function. IGF-1 is a potent modulator of stem cell replication, commitment to the myocyte lineage, and myocyte differentiation. In another study, the dual delivery of IGF-1 and HGF from affinity-binding alginate biomaterial prevented cell apoptosis, induced cardiomyocyte cell cycle re-entry and increased the incidence of GATA-4-positive cell clusters. The addition of nanofiber-mediated IGF-1 delivery to Cardiac Progenitor Cells therapy improved in part the recovery of myocardial structure and function after infarction. IGF-1 promotes proliferation and survival of CPCs. The strategy of IGF-1 transgene expression has shown to induce massive stem cell mobilization via SDF-1alpha signaling and culminated in extensive angiomyogenesis in the infarcted heart.

[18556576, 19704095, 16141414, 17805990, 16698918, 18948617, 9329962, 22403243, 20607468, 21621517, 21546606, 20889201, 17045939, 22590612, 21723061, 17525368, 15951423]

Ischemic heart disease is characterized chronically by a healed infarct, foci of myocardial scarring, cavitary dilation, and impaired ventricular performance. These alterations can only be reversed by replacement of scarred tissue with functionally competent myocardium. We tested whether cardiac progenitor cells (CPCs) implanted in proximity of healed infarcts or resident CPCs stimulated locally by hepatocyte growth factor and insulin-like growth factor-1 invade the scarred myocardium and generate myocytes and coronary vessels improving the hemodynamics of the infarcted heart. Hepatocyte growth factor is a powerful chemoattractant of CPCs, and insulin-like growth factor-1 promotes their proliferation and survival. Injection of CPCs or growth factors led to the replacement of approximately 42% of the scar with newly formed myocardium, attenuated ventricular dilation and prevented the chronic decline in function of the infarcted heart. Cardiac repair was mediated by the ability of CPCs to synthesize matrix metalloproteinases that degraded collagen proteins, forming tunnels within the fibrotic tissue during their migration across the scarred myocardium. New myocytes had a 2n karyotype and possessed 2 sex chromosomes, excluding cell fusion. Clinically, CPCs represent an ideal candidate cell for cardiac repair in patients with chronic heart failure. CPCs may be isolated from myocardial biopsies and, following their expansion in vitro, administered back to the same patients avoiding the adverse effects associated with the use of nonautologous cells. Alternatively, growth factors may be delivered locally to stimulate resident CPCs and promote myocardial regeneration. These forms of treatments could be repeated over time to reduce progressively tissue scarring and expand the working myocardium. BACKGROUND: Cardiac progenitor cells (CPCs) possess the insulin-like growth factor-1 (IGF-1)-IGF-1 receptor system, and IGF-1 can be tethered to self-assembling peptide nanofibers (NF-IGF-1), leading to prolonged release of this growth factor to the myocardium. Therefore, we tested whether local injection of clonogenic CPCs and NF-IGF-1 potentiates the activation and differentiation of delivered and resident CPCs enhancing cardiac repair after infarction. METHODS AND RESULTS: Myocardial infarction was induced in rats, and untreated infarcts and infarcts treated with CPCs or NF-IGF-1 only and CPCs and NF-IGF-1 together were analyzed. With respect to infarcts exposed to CPCs or NF-IGF-1 alone, combination therapy resulted in a greater increase in the ratio of left ventricular mass to chamber volume and a better preservation of +dP/dt, -dP/dt, ejection fraction, and diastolic wall stress. Myocardial regeneration was detected in all treated infarcts, but the number of newly formed myocytes with combination therapy was 32% and 230% higher than with CPCs and NF-IGF-1, respectively. Corresponding differences in the volume of regenerated myocytes were 48% and 115%. Similarly, the length density of newly formed coronary arterioles with both CPCs and NF-IGF-1 was 73% and 83% greater than with CPCs and NF-IGF-1 alone, respectively. Importantly, activation of resident CPCs by paracrine effects contributed to cardiomyogenesis and vasculogenesis. Collectively, CPCs and NF-IGF-1 therapy reduced infarct size more than CPCs and NF-IGF-1 alone. CONCLUSIONS: The addition of nanofiber-mediated IGF-1 delivery to CPC therapy improved in part the recovery of myocardial structure and function after infarction. Cardiac stem cells and early committed cells (CSCs-ECCs) express c-Met and insulin-like growth factor-1 (IGF-1) receptors and synthesize and secrete the corresponding ligands, hepatocyte growth factor (HGF) and IGF-1. HGF mobilizes CSCs-ECCs and IGF-1 promotes their survival and proliferation. Therefore, HGF and IGF-1 were injected in the hearts of infarcted mice to favor, respectively, the translocation of CSCs-ECCs from the surrounding myocardium to the dead tissue and the viability and growth of these cells within the damaged area. To facilitate migration and homing of CSCs-ECCs to the infarct, a growth factor gradient was introduced between the site of storage of primitive cells in the atria and the region bordering the infarct. The newly-formed myocardium contained arterioles, capillaries, and functionally competent myocytes that with time increased in size, improving ventricular performance at healing and long thereafter. The volume of regenerated myocytes was 2200 microm3 at 16 days after treatment and reached 5100 microm3 at 4 months. In this interval, nearly 20% of myocytes reached the adult phenotype, varying in size from 10,000 to 20,000 microm3. Moreover, there were 43+/-13 arterioles and 155+/-48 capillaries/mm2 myocardium at 16 days, and 31+/-6 arterioles and 390+/-56 capillaries at 4 months. Myocardial regeneration induced increased survival and rescued animals with infarcts that were up to 86% of the ventricle, which are commonly fatal. In conclusion, the heart has an endogenous reserve of CSCs-ECCs that can be activated to reconstitute dead myocardium and recover cardiac function. Strategies for cardiac repair include injection of cells, but these approaches have been hampered by poor cell engraftment, survival, and differentiation. To address these shortcomings for the purpose of improving cardiac function after injury, we designed self-assembling peptide nanofibers for prolonged delivery of insulin-like growth factor 1 (IGF-1), a cardiomyocyte growth and differentiation factor, to the myocardium, using a "biotin sandwich" approach. Biotinylated IGF-1 was complexed with tetravalent streptavidin and then bound to biotinylated self-assembling peptides. This biotin sandwich strategy allowed binding of IGF-1 but did not prevent self-assembly of the peptides into nanofibers within the myocardium. IGF-1 that was bound to peptide nanofibers activated Akt, decreased activation of caspase-3, and increased expression of cardiac troponin I in cardiomyocytes. After injection into rat myocardium, biotinylated nanofibers provided sustained IGF-1 delivery for 28 days, and targeted delivery of IGF-1 in vivo increased activation of Akt in the myocardium. When combined with transplanted cardiomyocytes, IGF-1 delivery by biotinylated nanofibers decreased caspase-3 cleavage by 28% and increased the myocyte cross-sectional area by 25% compared with cells embedded within nanofibers alone or with untethered IGF-1. Finally, cell therapy with IGF-1 delivery by biotinylated nanofibers improved systolic function after experimental myocardial infarction, demonstrating how engineering the local cellular microenvironment can improve cell therapy. We hypothesized that mesenchymal stem cells (MSCs) overexpressing insulin-like growth factor (IGF)-1 showed improved survival and engraftment in the infarcted heart and promoted stem cell recruitment through paracrine release of stromal cell-derived factor (SDF)-1alpha. Rat bone marrow-derived MSCs were used as nontransduced ((Norm)MSCs) or transduced with adenoviral-null vector ((Null)MSCs) or vector encoding for IGF-1 ((IGF-1)MSCs). (IGF-1)MSCs secreted higher IGF-1 until 12 days of observation (P<0.001 versus (Null)MSCs). Molecular studies revealed activation of phosphoinositide 3-kinase, Akt, and Bcl.xL and inhibition of glycogen synthase kinase 3beta besides release of SDF-1alpha in parallel with IGF-1 expression in (IGF-1)MSCs. For in vivo studies, 70 muL of DMEM without cells (group 1) or containing 1.5x10(6) (Null)MSCs (group 2) or (IGF-1)MSCs (group 3) were implanted intramyocardially in a female rat model of permanent coronary artery occlusion. One week later, immunoblot on rat heart tissue (n=4 per group) showed elevated myocardial IGF-1 and phospho-Akt in group 3 and higher survival of (IGF-1)MSCs (P<0.06 versus (Null)MSCs) (n=6 per group). SDF-1alpha was increased in group 3 animal hearts (20-fold versus group 2), with massive mobilization and homing of ckit(+), MDR1(+), CD31(+), and CD34(+) cells into the infarcted heart. Infarction size was significantly reduced in cell transplanted groups compared with the control. Confocal imaging after immunostaining for myosin heavy chain, actinin, connexin-43, and von Willebrand factor VIII showed extensive angiomyogenesis in the infarcted heart. Indices of left ventricular function, including ejection fraction and fractional shortening, were improved in group 3 as compared with group 1 (P<0.05). In conclusion, the strategy of IGF-1 transgene expression induced massive stem cell mobilization via SDF-1alpha signaling and culminated in extensive angiomyogenesis in the infarcted heart. To determine whether IGF-1 opposes the stimulation of myocyte death in the surviving myocardium after infarction, transgenic mice overexpressing human IGF-1B in myocytes (FVB.Igf+/-) and wild-type littermates at 1.5 and 2.5 mo of age were subjected to coronary ligation and killed 7 d later. Myocardial infarction involved an average 50% of the left ventricle, and produced cardiac failure. In the region proximate to infarction, myocyte apoptosis increased 4. 2-fold and 2.1-fold in nontransgenics at 1.5 and 2.5 mo, respectively. Corresponding increases in myocyte necrosis were 1. 8-fold and 1.6-fold. In contrast, apoptotic and necrotic myocyte death did not increase in FVB.Igf+/- mice at either age after infarction. In 2.5-mo-old infarcted nontransgenics, functional impairment was associated with a 29% decrease in wall thickness, 43% increase in chamber diameter, and a 131% expansion in chamber volume. Conversely, the changes in wall thickness, chamber diameter, and cavitary volume were 41, 58, and 48% smaller in infarcted FVB.Igf+/- than in nontransgenics. The differential response to infarction of FVB.Igf+/- mice resulted in an attenuated increase in diastolic wall stress, cardiac weight, and left and right ventricular weight-to-body wt ratios. In conclusion, constitutive overexpression of IGF-1 prevented activation of cell death in the viable myocardium after infarction, limiting ventricular dilation, myocardial loading, and cardiac hypertrophy. Although most medicines have historically been small molecules, many newly approved drugs are derived from proteins. Protein therapies have been developed for treatment of diseases in almost every organ system, including the heart. Great excitement has now arisen in the field of regenerative medicine, particularly for cardiac regeneration after myocardial infarction. Every year, millions of people suffer from acute myocardial infarction, but the adult mammalian myocardium has limited regeneration potential. Regeneration of the heart after myocardium infarction is therefore an exciting target for protein therapeutics. In this review, we discuss different classes of proteins that have therapeutic potential to regenerate the heart after myocardial infarction. Protein candidates have been described that induce angiogenesis, including fibroblast growth factors and vascular endothelial growth factors, although thus far clinical development has been disappointing. Chemotactic factors that attract stem cells, e.g., hepatocyte growth factor and stromal cell-derived factor-1, may also be useful. Finally, neuregulins and periostin are proteins that induce cell-cycle reentry of cardiomyocytes, and growth factors like IGF-1 can induce growth and differentiation of stem cells. As our knowledge of the biology of regenerative processes and the role of specific proteins in these processes increases, the use of proteins as regenerative drugs could develop as a cardiac therapy. RATIONALE: Age and coronary artery disease may negatively affect the function of human cardiac stem cells (hCSCs) and their potential therapeutic efficacy for autologous cell transplantation in the failing heart. OBJECTIVE: Insulin-like growth factor (IGF)-1, IGF-2, and angiotensin II (Ang II), as well as their receptors, IGF-1R, IGF-2R, and AT1R, were characterized in c-kit(+) hCSCs to establish whether these systems would allow us to separate hCSC classes with different growth reserve in the aging and diseased myocardium. METHODS AND RESULTS: C-kit(+) hCSCs were collected from myocardial samples obtained from 24 patients, 48 to 86 years of age, undergoing elective cardiac surgery for coronary artery disease. The expression of IGF-1R in hCSCs recognized a young cell phenotype defined by long telomeres, high telomerase activity, enhanced cell proliferation, and attenuated apoptosis. In addition to IGF-1, IGF-1R(+) hCSCs secreted IGF-2 that promoted myocyte differentiation. Conversely, the presence of IGF-2R and AT1R, in the absence of IGF-1R, identified senescent hCSCs with impaired growth reserve and increased susceptibility to apoptosis. The ability of IGF-1R(+) hCSCs to regenerate infarcted myocardium was then compared with that of unselected c-kit(+) hCSCs. IGF-1R(+) hCSCs improved cardiomyogenesis and vasculogenesis. Pretreatment of IGF-1R(+) hCSCs with IGF-2 resulted in the formation of more mature myocytes and superior recovery of ventricular structure. CONCLUSIONS: hCSCs expressing only IGF-1R synthesize both IGF-1 and IGF-2, which are potent modulators of stem cell replication, commitment to the myocyte lineage, and myocyte differentiation, which points to this hCSC subset as the ideal candidate cell for the management of human heart failure. Proper spatio-temporal delivery of multiple therapeutic proteins represents a major challenge in therapy strategies aimed at inducing myocardial regeneration after myocardial infarction (MI). We hypothesized that the dual delivery of insulin-like growth factor-1 (IGF-1) and hepatocyte growth factor (HGF) by injectable affinity-binding alginate biomaterial would maximize their therapeutic effects, leading to a more favorable course of tissue restoration after acute MI. A sequential release of IGF-1 followed by HGF was attained from affinity-binding alginate biomaterial, which also protected the proteins from proteolysis (shown by mass spectroscopy). The released factors retained bioactivity, as judged by their capability to activate their respective signaling pathways and to prevent cardiomyocyte apoptosis in vitro. In a rat model of acute MI, an intramyocardial injection of the dual IGF-1/HGF affinity-bound alginate biomaterial preserved scar thickness, attenuated infarct expansion and reduced scar fibrosis after 4 weeks, concomitantly with increased angiogenesis and mature blood vessel formation at the infarct. Furthermore, this treatment prevented cell apoptosis, induced cardiomyocyte cell cycle re-entry and increased the incidence of GATA-4-positive cell clusters. The dual delivery of IGF-1 and HGF from affinity-binding alginate biomaterial represents a useful strategy to treat MI. It showed a marked therapeutic efficacy at various tissue levels, as well as potential to induce endogenous regeneration of cardiac muscle. BACKGROUND: Myoblast transplantation (Tx) is promising for the improvement of cardiac function in ischemic cardiomyopathy. Insulin-like growth factor-1 (IGF-1) has anti-apoptotic and angiogenic effects, and induces myocyte hypertrophy. Our hypothesis is that topical and slow-release IGF-1 enhances the efficacy of Tx through its multiple functions. METHODS: Four weeks after coronary artery ligation, Lewis rats were divided into four groups: (1) IGF-1+Tx, injection of 6 x 10(6) myoblasts into the infarcted area with placement of an IGF-1-impregnated sheet on the left ventricular (LV) free wall; (2) Tx, Tx alone; (3) IGF-1, IGF-1 sheet alone; and (4) control. We measured cardiac function and performed immunohistochemical examinations. RESULTS: At 4 weeks after treatment, LV diastolic dimension was the smallest, end-systolic elastance was the highest, and tau was the smallest in the IGF-1+Tx group. The graft volume in the IGF-1+Tx group was 3-fold larger than in the Tx group. One day after transplantation, TUNEL-positive donor cells were fewer in the IGF-1+Tx than in the Tx group. Western blot analysis demonstrated that the phosphorylation of Akt increased and the expression of Bax decreased in the transplanted area of IGF-1+Tx rats compared with Tx rats. The vascular density in the peri-infarcted area was larger in IGF-1+Tx than in Tx rats. The mean diameter of graft-derived myotubes was larger in IGF-1+Tx than in Tx animals. CONCLUSIONS: IGF-1 increases the graft volume and enhances the efficacy of Tx in the chronic myocardial infarction model due to its multiple effects of preventing apoptosis, inducing angiogenesis, and promoting myoblast growth. To explore how cardiac regeneration and cell turnover adapts to disease, different forms of stress were studied for their effects on the cardiac progenitor cell markers c-Kit and Isl1, the early cardiomyocyte marker Nkx2.5, and mast cells. Adult female rats were examined during pregnancy, after myocardial infarction and ischemia-reperfusion injury with/out insulin like growth factor-1(IGF-1) and hepatocyte growth factor (HGF). Different cardiac sub-domains were analyzed at one and two weeks post-intervention, both at the mRNA and protein levels. While pregnancy and myocardial infarction up-regulated Nkx2.5 and c-Kit (adjusted for mast cell activation), ischemia-reperfusion injury induced the strongest up-regulation which occurred globally throughout the entire heart and not just around the site of injury. This response seems to be partly mediated by increased endogenous production of IGF-1 and HGF. Contrary to c-Kit, Isl1 was not up-regulated by pregnancy or myocardial infarction while ischemia-reperfusion injury induced not a global but a focal up-regulation in the outflow tract and also in the peri-ischemic region, correlating with the up-regulation of endogenous IGF-1. The addition of IGF-1 and HGF did boost the endogenous expression of IGF and HGF correlating to focal up-regulation of Isl1. c-Kit expression was not further influenced by the exogenous growth factors. This indicates that there is a spatial mismatch between on one hand c-Kit and Nkx2.5 expression and on the other hand Isl1 expression. In conclusion, ischemia-reperfusion injury was the strongest stimulus with both global and focal cardiomyocyte progenitor cell marker up-regulations, correlating to the endogenous up-regulation of the growth factors IGF-1 and HGF. Also pregnancy induced a general up-regulation of c-Kit and early Nkx2.5+ cardiomyocytes throughout the heart. Utilization of these pathways could provide new strategies for the treatment of cardiac disease.

What is known about prostate cancer screening in the UK

Screening for early disease has been available for many years, but there is still no national screening programme established in the United Kingdom. Two systematic reviews have concluded that screening should not be carried out. In general, this recommendation has been accepted in the United Kingdom.

[20507844, 20060331, 17826892, 23728749, 19904272, 11495383, 20840664, 19671770]

BACKGROUND: Web-based decision aids are known to have an effect on knowledge, attitude, and behavior; important components of informed decision making. We know what decision aids achieve in randomized controlled trials (RCTs), but we still know very little about how they are used and how this relates to the informed decision making outcome measures. OBJECTIVE: To examine men's use of an online decision aid for prostate cancer screening using website transaction log files (web-logs), and to examine associations between usage and components of informed decision making. METHODS: We conducted an observational web-log analysis of users of an online decision aid, Prosdex. Men between 50 and 75 years of age were recruited for an associated RCT from 26 general practices across South Wales, United Kingdom. Men allocated to one arm of the RCT were included in the current study. Time and usage data were derived from website log files. Components of informed decision making were measured by an online questionnaire. RESULTS: Available for analysis were 82 web-logs. Overall, there was large variation in the use of Prosdex. The mean total time spent on the site was 20 minutes. The mean number of pages accessed was 32 (SD 21) out of a possible 60 pages. Significant associations were found between increased usage and increased knowledge (Spearman rank correlation [rho] = 0.69, P < .01), between increased usage and less favorable attitude towards PSA testing (rho = -0.52, P < .01), and between increased usage and reduced intention to undergo PSA testing (rho = -0.44, P < .01). A bimodal distribution identified two types of user: low access and high access users. CONCLUSIONS: Increased usage of Prosdex leads to more informed decision making, the key aim of the UK Prostate Cancer Risk Management Programme. However, developers realistically have roughly 20 minutes to provide useful information that will support informed decision making when the patient uses a web-based interface. Future decision aids need to be developed with this limitation in mind. We recommend that web-log analysis should be an integral part of online decision aid development and analysis. TRIAL REGISTRATION: ISRCTN48473735; http://www.controlled-trials.com/ISRCTN48473735 (Archived by WebCite at http://www.webcitation.org/5pqeF89tS). Prostate specific antigen (PSA) was introduced as a prostate cancer screening tool more than 20 years ago. However, there is continuing debate regarding its utility in screening for prostate cancer. Mass screening is costly, may result in the diagnosis and treatment of prostate cancers that never become clinically significant, and the evidence of a subsequent reduction in mortality is inconclusive. In addition to its role in screening, PSA is also used to monitor the progression of the disease, both localized and metastatic. Although the evidence is contradictory, PSA is still an important tool for monitoring patient progression following treatment of definitive localized prostate cancer. However, its use in monitoring castrate-resistant prostate cancer (CRPC) is more controversial, particularly in the context of novel targeted treatments, which may have little impact on PSA levels. These issues highlight the urgent need to identify prostate cancer biomarkers that will improve early disease detection, increase accuracy of diagnosis, determine the aggressiveness of disease, and monitor treatment efficacy, particularly in late-stage disease. This review discusses the key issues associated with the use of PSA as an early screening tool for prostate cancer, as a prognostic marker to measure disease progression in both early- and late-stage prostate cancer, and as a surrogate endpoint in clinical trials with new agents. OBJECTIVES: To review evidence regarding the potential introduction of prostate cancer screening programmes and highlight issues pertinent to the management of screen-detected prostate cancer. METHODS: Screening for prostate cancer is a controversial health care issue in general and urological practice. A PubMed database search was performed, followed by a systematic review of the literature, to examine the evidence base underlying prostate cancer screening. RESULTS: A prostate cancer screening programme should satisfy several key postulates prior to its introduction. To date, several of these postulates have not been satisfied, and the evidence available for prostate cancer screening is currently insufficient to warrant its introduction as a public health policy. The natural history of screen-detected prostate cancer remains poorly understood, and recent evidence suggests that a screening programme may detect a large number of men with indolent disease who may be subsequently overtreated. Several randomised clinical trials are currently in progress and it is hoped that they will provide robust evidence to inform future practice. CONCLUSIONS: National systematic prostate cancer screening programmes outside randomised clinical trial settings have not been implemented to date owing to lack of robust evidence that such programmes would improve survival and/or quality of life in men with screen-detected disease. Forthcoming results of clinical trials and the application of appropriate risk stratification to prevent overtreatment of indolent prostate cancer are likely to change practice in coming years. INTRODUCTION: Prostate cancer is the commonest cancer in men and a major health issue worldwide. Screening for early disease has been available for many years, but there is still no national screening programme established in the United Kingdom. OBJECTIVE: To assess the latest evidence regarding prostate cancer screening and whether it meets the necessary requirements to be established as a national programme for all men. METHODS: Electronic databases and library catalogues were searched electronically and manual retrieval was performed. Only primary research results were used for the analysis. RESULTS: In recent years, several important randomised controlled trials have produced varied outcomes. In Europe the largest study thus far concluded that screening reduced prostate cancer mortality by 20%. On the contrary, a large American trial found no reduction in mortality after 7-10 years follow-up. Most studies comment on the adverse effects of screening - principally those of overdiagnosis and subsequent overtreatment. DISCUSSION: Further information about the natural history of prostate cancer and accuracy of screening is needed before a screening programme can be truly justified. In the interim, doctors and patients should discuss the risks, benefits and sequelae of taking part in voluntary screening for prostate cancer. OBJECTIVE: To evaluate the role of targeted prostate cancer screening in men with BRCA1 or BRCA2 mutations, an international study, IMPACT (Identification of Men with a genetic predisposition to ProstAte Cancer: Targeted screening in BRCA1/2 mutation carriers and controls), was established. This is the first multicentre screening study targeted at men with a known genetic predisposition to prostate cancer. A preliminary analysis of the data is reported. PATIENTS AND METHODS: Men aged 40-69 years from families with BRCA1 or BRCA2 mutations were offered annual prostate specific antigen (PSA) testing, and those with PSA > 3 ng/mL, were offered a prostate biopsy. Controls were men age-matched (± 5 years) who were negative for the familial mutation. RESULTS: In total, 300 men were recruited (205 mutation carriers; 89 BRCA1, 116 BRCA2 and 95 controls) over 33 months. At the baseline screen (year 1), 7.0% (21/300) underwent a prostate biopsy. Prostate cancer was diagnosed in ten individuals, a prevalence of 3.3%. The positive predictive value of PSA screening in this cohort was 47·6% (10/21). One prostate cancer was diagnosed at year 2. Of the 11 prostate cancers diagnosed, nine were in mutation carriers, two in controls, and eight were clinically significant. CONCLUSIONS: The present study shows that the positive predictive value of PSA screening in BRCA mutation carriers is high and that screening detects clinically significant prostate cancer. These results support the rationale for continued screening in such men. Making informed decisions about breast and prostate cancer screening requires knowledge of its benefits. However, country-specific information on public knowledge of the benefits of screening is lacking. Face-to-face computer-assisted personal interviews were conducted with 10,228 persons selected by a representative quota method in nine European countries (Austria, France, Germany, Italy, the Netherlands, Poland, Russia, Spain, and the United Kingdom) to assess perceptions of cancer-specific mortality reduction associated with mammography and prostate-specific antigen (PSA) screening. Participants were also queried on the extent to which they consulted 14 different sources of health information. Correlation coefficients between frequency of use of particular sources and the accuracy of estimates of screening benefit were calculated. Ninety-two percent of women overestimated the mortality reduction from mammography screening by at least one order of magnitude or reported that they did not know. Eighty-nine percent of men overestimated the benefits of PSA screening by a similar extent or did not know. Women and men aged 50-69 years, and thus targeted by screening programs, were not substantially better informed about the benefits of mammography and PSA screening, respectively, than men and women overall. Frequent consulting of physicians (r = .07, 95% confidence interval [CI] = 0.05 to 0.09) and health pamphlets (r = .06, 95% CI = 0.04 to 0.08) tended to increase rather than reduce overestimation. The vast majority of citizens in nine European countries systematically overestimate the benefits of mammography and PSA screening. In the countries investigated, physicians and other information sources appear to have little impact on improving citizens' perceptions of these benefits.

Can a peptide aptamer be used as protein inhibitor?

Yes, peptide aptamers can be used as inhibitors.

[10439043, 21296653, 24130701, 19150354, 20842131, 20191379, 17917077, 12123800, 16581027, 22714536, 22533554, 19389625, 16139842, 16815302, 18195017, 22811618, 22956136, 18186614, 24188027]

The p16-cyclin D-pRB-E2F pathway is frequently deregulated in human tumors. This critical regulatory pathway controls the G1/S transition of the mammalian cell cycle by positive and negative regulation of E2F-responsive genes required for DNA replication. To assess the value of the transcription factors E2Fs as targets for antiproliferative strategies, we have initiated a program aiming to develop inhibitors targeting specifically these proteins in vitro and in vivo. The cellular activity of E2F is the result of the heterodimeric association of two families of proteins, E2Fs and DPs, which then bind DNA. Here, we use a two hybrid approach to isolate from combinatorial libraries peptide aptamers that specifically interact with E2Fs DNA binding and dimerization domains. One of these is a potent inhibitor of E2F binding activity in vitro and in mammalian fibroblasts, blocks cells in G1, and the free variable region from this aptamer has the same effect. Our experiments argue that the variable region of this aptamer is structured, and that it functions by binding E2F with a motif that resembles a DP heterodimerization region, and blocking E2F's association with DP. These results show that cell proliferation can be inhibited using genetically-selected synthetic peptides that specifically target protein-protein interaction motifs within cell cycle regulators. These results also emphasize the critical role of the E2F pathway for cell proliferation and might allow the design of novel antiproliferative agents targeting the cyclin/CDK-pRB-E2F pathway. The eukaryotic DNA recombination repair protein BRCA2 is functional in the parasitic protozoan Trypanosoma brucei. The mechanism of the involvement of BRCA2 in homologous recombination includes its interaction with the DNA recombinase proteins of the RAD51 family. BRCA2 is known to interact with RAD51 through its unique and essential BRC sequence motifs. T. brucei BRCA2 homolog (TbBRCA2) has fifteen repeating BRC motifs as compared to mammalian BRCA2 that has only eight. We report here our yeast 2-hybrid analysis studies on the interactions of TbBRCA2 BRC motifs with five different RAD51 paralogues of T. brucei. Our study revealed that a single BRC motif is sufficient to bind to these RAD51 paralogues. To test the possibility whether a single 44 amino acid long repeating unit of the TbBRCA2 BRC motif may be exploited as an inhibitor of T. brucei growth, we ectopically expressed this peptide segment in the procyclic form of the parasite and evaluated its effects on cell survival as well as the sensitivity of these cells to the DNA damaging agent methyl methane sulfonate (MMS). Expression of a single BRC motif led to MMS sensitivity and inhibited cellular proliferation in T. brucei. To identify critical host factors necessary for human immunodeficiency virus 1 (HIV-1) replication, large libraries of short-peptide-aptamers were expressed retrovirally. The target of one inhibitor peptide, Pep80, identified in this screen was determined to be Snapin, a protein associated with the soluble N-ethyl maleimide sensitive factor adaptor protein receptor (SNARE) complex that is critical for calcium-dependent exocytosis during neurotransmission. Pep80 inhibited Ca²⁺ release from intracellular stores and blocked downstream signaling by direct interruption of the association between Snapin and an intracellular calcium release channel, the ryanodine receptor (RyR). NFAT signaling was preferentially abolished by Pep80. Expression of Snapin overcame Pep80-mediated inhibition of Ca²⁺/NFAT signaling and HIV-1 replication. Furthermore, Snapin induced HIV-1 replication in primary CD4⁺ T cells. Thus, through its interaction with RyR, Snapin is a critical regulator of Ca²⁺ signaling and T cell activation. Use of the genetically selected intracellular aptamer inhibitors allowed us to define unique mechanisms important to HIV-1 replication and T cell biology. Proteases are involved in various biological functions. Thus, inhibition of their activities is scientifically interesting and medically important. However, there is no systematic method established to date to generate endopeptidase inhibitory peptides. Here, we report a general system to identify endopeptidase inhibitory peptides based on the use of in vitro evolution. Using this system, we generated peptides that inhibit cathepsin E (CE) specifically at a submicromolar IC(50). This system generates protease inhibitor peptides utilizing techniques of cDNA display, selection-by-function, Y-ligation-based block shuffling, and others. We further demonstrated the importance and effectiveness of a secondary library for obtaining small-sized and active peptides. CE inhibitory peptides generated by this method were characterized by a small size (8 to 12 aa) and quite different sequences, suggesting that they bind to different sites on CE. Typical CE inhibitory peptide aptamers obtained here (P(i)101; SCGG IIII SCIA) have half an inhibition activity (K(i); 5 nM) of pepstatin A (potent CE inhibitor) without inhibiting cathepsin D (structurally similar to CE). The general applicability of this system suggests that it may be useful to identify inhibitory peptides for various kinds of proteases and that it may therefore contribute to protein science and drug discovery. The peptide binding to a protein is discussed in comparison with the antibody binding to an antigen. BACKGROUND: Inhibitors of DNA-binding proteins (Id1-4), lacking the basic DNA-binding domain, function as dominant inhibitors of cell-cycle regulators. Overexpression of Id proteins promotes cancer cell proliferation and resistance against apoptosis. Level of Id protein expression, especially of Id1, correlates with poor differentiation, enhanced malignant potential and more aggressive clinical behaviour of ovarian tumours. Although overexpression of Ids has been found and shown to correlate with poor clinical outcome, their inhibition at protein level has never been studied. METHODS: A peptide aptamer, Id1/3-PA7, targeting Id1 and Id3, was isolated from a randomised combinatorial expression library using yeast and mammalian two-hybrid systems. Id1/3-PA7 was fused, expressed and purified with a cell-penetrating protein transduction domain. RESULTS: Intracellular-delivered Id1/3-PA7 colocalised to Id1 and Id3. It induced cell-cycle arrest and apoptosis in ovarian cancer cells ES-2 and PA-1. It activated the E-box promoter and increased the expression level of cyclin-dependent kinase inhibitor (CDKN2A) in a dose-dependent manner that is paralleled by the cleavage of poly-ADP ribose polymerase. These effects were counteracted by ectopically overexpressed Id1 and Id3. CONCLUSION: Id1/3-PA7 could represent an exogenous anti-tumour agent that can significantly trigger cell-cycle arrest and apoptosis in ovarian cancer. Inhibitors of differentiation or DNA binding (Id) proteins have been shown to be involved in tumor growth, invasiveness, metastasis, and angiogenesis. Overexpression of Id proteins, especially Id1, correlates with unfavorable clinical prognosis. Thus, they are attractive molecular targets for anticancer therapy. Overexpression of Id proteins mediates breast cancer metastasis to lung. Targeting Id1 and Id3 expression in breast cancer cells reduces breast cancer metastasis in animal models. Different breast tumors failed to grow and/or metastasize in Id1 (+/-) Id3 (-/-) mice. Id1 and Id3 preferentially dimerize with the key regulatory E-proteins which inhibit the expression of different tumor suppressor genes. Nevertheless, the inhibition of tumorigenic activities of Id1 and Id3 at protein level has never been studied. Here, we isolated a novel peptide aptamer, Id1/3-PA7, specifically interacting with Id1 and Id3 from randomized combinatorial expression library using yeast and mammalian two-hybrid systems. Intracellular delivered Id1/3-PA7 co-localized to Id1 and Id3 and interfered with their functions. It repressed E47 protein sequestration by Id1 and Id3, activated the E-box promoter and increased the expression level of cyclin-dependent kinase inhibitors (CDKN1A and CDKN1B) in a dose-dependent fashion, paralleled by the cleavage of poly ADP ribose polymerase (PARP). These effects were counteracted by ectopically overexpressed Id1 and Id3. Peptide aptamer Id1/3-PA7 induced cell cycle arrest and apoptosis in breast cancer cells MCF7 and MDA-MB-231. In conclusion, Id1/3-PA7 could represent a nontoxic exogenous agent that can significantly provoke antiproliferative and apoptotic effects in breast cancer cells, which are associated with deregulated expression of Id1 and Id3. Amyloid-beta peptide-binding alcohol dehydrogenase (ABAD) inhibiting peptide, as a specific inhibitor between ABAD and amyloid-beta (Abeta), has been demonstrated to effectively inhibit Abeta peptide cytotoxicity. However, a major drawback is its short half-life, which results in the need for multiple applications and high synthesis costs. To overcome this, we established a lentiviral expression system that allowed the stable expression of the small ABAD-inhibiting peptide by fusion with cytosolic thioredoxin-1 (TRX). The fusion peptide, TA aptamer, was observed within PC12 cytoplasm and maintained both Abeta-binding ability and antioxygenic property similar to TRX. Our data showed that overexpression of both TRX and TA aptamer could protect PC12 cells from intracellular Abeta cytotoxicity. The present study suggests that TRX, as a cytosolic protein and a fusion motif, could not only assist ABAD-inhibiting peptide expression, cytoplasmic localization, but rebalance the disturbed "redox equilibrium" caused by intracellular Abeta in PC12 cells. The Rho-guanine nucleotide exchange factors (Rho-GEFs) remodel the actin cytoskeleton via their Rho-GTPase targets and affect numerous physiological processes such as transformation and cell motility. They are therefore attractive targets to design specific inhibitors that may have therapeutic applications. Trio contains two Rho-GEF domains, GEFD1 and GEFD2, which activate the Rac and RhoA pathways, respectively. Here we have used a genetic screen in yeast to select in vivo peptides coupled to thioredoxin, called aptamers, that could inhibit GEFD2 activity. One aptamer, TRIAPalpha (TRio Inhibitory APtamer), specifically blocks GEFD2-exchange activity on RhoA in vitro. The corresponding peptide sequence, TRIPalpha, inhibits TrioGEFD2-mediated activation of RhoA in intact cells and specifically reverts the neurite retraction phenotype induced by TrioGEFD2 in PC12 cells. Thus TRIPalpha is the first Rho-GEF inhibitor isolated so far, and represents an important step in the design of inhibitors for the expanding family of Rho-GEFs. FLASH protein is a component of death-inducing signaling complex and might be involved in death receptor-mediated extrinsic apoptosis. Here we developed the peptide aptamer against death effecter domain recruiting domain (DRD) of FLASH protein and showed that the peptide bound to FLASH protein in vitro. Intracellular expression of the DRD-binding peptide aptamer specifically suppressed receptor-mediated extrinsic apoptosis but not intrinsic pathway, which was recapitulated by the antisense oligonucleotides for FLASH. These data suggest that DRD-binding peptide is not only a novel inhibitor modulating receptor-mediated apoptosis but also a tool for elucidating the roles of FLASH in apoptosis. Among the many abnormally expressed proteins in ovarian cancer, the prominent cancer in women, ID1 (inhibitors of DNA binding protein 1) is a potential one among other several targets. Interaction of ID1 with ETS-1 (transcriptional activator of p16(INK4a)) suppresses the transcription of p16(INK4a) and causes abnormal cell proliferation. A peptide aptamer (ID1/3-PA7) has been designed to prevent this interaction and thereby leading to the transcription of p16(INK4a). However, the structural basis behind the molecular interaction of ID1 with ETS-1 (agonist) and ID1/3-PA7 (antagonist) is poorly understood. In order to understand this structural recognition and their interaction mechanism, in silico methods were used. From this interaction analysis, the residues of ETS-1 involved in interaction with the p16(INK4a) promoter were found to be targeted by ID1. Subsequently, ETS-1 binding residues of ID1 were found to be targeted by its aptamer- ID1/3-PA7. These results suggest that both ETS-1 and ID1/3-PA7 binds at the same region harbored by the residues-H97, D100, R103, D104, L107, A144, C145, D149, D150 and C154 of ID1. All these observations correlate with the experimental reports, suggesting that the identified residues might play a crucial role in promulgating the oncogenic effects of ID1. In silico alanine scanning mutagenesis also confirms the role of identified hot spot residues in p16(INK4a) regulation. Finally, the molecular dynamic simulation studies reveal the prolonged stability of the aforementioned interacting complexes. The obtained results throw light on the structure and residues of ID1 involved in transcriptional regulation of p16(INK4a). Peptide aptamers are peptides constrained and presented by a scaffold protein that are used to study protein function in cells. They are able to disrupt protein-protein interactions and to constitute recognition modules that allow the creation of a molecular toolkit for the intracellular analysis of protein function. The success of peptide aptamer technology is critically dependent on the performance of the scaffold. Here, we describe a rational approach to the design of a new peptide aptamer scaffold. We outline the qualities that an ideal scaffold would need to possess to be broadly useful for in vitro and in vivo studies and apply these criteria to the design of a new scaffold, called STM. Starting from the small, stable intracellular protease inhibitor stefin A, we have engineered a biologically neutral scaffold that retains the stable conformation of the parent protein. We show that STM is able to present peptides that bind to targets of interest, both in the context of known interactors and in library screens. Molecular tools based on our scaffold are likely to be used in a wide range of studies of biological pathways, and in the validation of drug targets. In order to efficiently select aptamers that bind to and inhibit proteins, we developed a method that involves screening DNA aptamers based on their inhibitory activities using an evolution-mimicking algorithm after the pre-selection by SELEX. The value of this method was demonstrated by the identification of an inhibitor of Taq DNA polymerase in a unique single-stranded DNA library, which was expected to form a G-quartet structure. This method consists of selection via an inhibition assay, sequence shuffling, and mutation in silico. After six rounds of selection, the inhibitory activities of the aptamers had evolved significantly. This demonstrates the utility of this strategy for screening aptamers based on their inhibitory actions. Many advanced tumors produce excessive amounts of Transforming Growth Factor-β (TGF-β) which, in normal epithelial cells, is a potent growth inhibitor. However, in oncogenically activated cells, the homeostatic action of TGF-β is often diverted along alternative pathways. Hence, TGF-β signaling elicits protective or tumor suppressive effects during the early growth-sensitive stages of tumorigenesis. However, later in tumor development when carcinoma cells become refractory to TGF-β-mediated growth inhibition, the tumor cell responds by stimulating pathways with tumor progressing effects. At late stages of malignancy, tumor progression is driven by TGF-β overload. The tumor microenvironment is a target of TGF-β action that stimulates tumor progression via pro-tumorigenic effects on vascular, immune, and fibroblastic cells. Bone is one of the richest sources of TGF-β in the body and a common site for dissemination of breast cancer metastases. Osteoclastic degradation of bone matrix, which accompanies establishment and growth of metastases, triggers further release of bone-derived TGF-β. This leads to a vicious positive feedback of tumor progression, driven by ever increasing levels of TGF-β released from both the tumor and bone matrix. It is for this reason, that pharmaceutical companies have developed therapeutic agents that block TGF-β signaling. Nonetheless, the choice of drug design and dosing strategy can affect the efficacy of TGF-β therapeutics. This review will describe pre-clinical and clinical data of four major classes of TGF-β inhibitor, namely i) ligand traps, ii) antisense oligonucleotides, iii) receptor kinase inhibitors and iv) peptide aptamers. Long term dosing strategies with TGF-β inhibitors may be ill-advised, since this class of drug has potentially highly pleiotropic activity, and development of drug resistance might potentiate tumor progression. Current paradigms for the use of TGF-β inhibitors in oncology have therefore moved towards the use of combinatorial therapies and short term dosing, with considerable promise for the clinic. Accumulating work over the past decade has shown that peptide aptamer screening represents a valid strategy for inhibitor identification that can be applied to a variety of different targets. Because of the screening method in cells and the highly combinatorial libraries available, this approach yields rapidly highly specific candidate inhibitors. Once a hit peptide has been identified, its interaction strength and affinity towards its target protein can be optimized even more, in order to increase its inhibition efficiency when subsequently applied in vivo. A condition to a successful optimization is that gain of inhibition strength should not result in loss of specificity. Here we present a simple method for peptide aptamer optimization, which can be achieved by PCR-based random mutagenesis combined with a selection screen in yeast using a strong selective drug. The rationale of this approach, which has proven valid and efficient, is that stronger interaction in yeast will also lead to stronger inhibition. Our optimization method is effective, without loss of specificity, which is of a great importance for the discovery of inhibitors that target specific protein-protein interactions. Peptide aptamers of LIM-only protein 2 (Lmo2) were previously used to successfully treat Lmo2-induced tumours in a mouse model of leukaemia. Here we show that the Lmo2 aptamer PA207, either as a free peptide or fused to thioredoxin Trx-PA207, causes purified Lmo2 to precipitate rather than binding to a defined surface on the protein. Stabilisation of Lmo2 through interaction with LIM domain binding protein 1 (Ldb1), a normal binding partner of Lmo2, abrogates this effect. The addition of free zinc causes Trx-PA207 to self associate, suggesting that PA207 destabilises Lmo2 by modulating normal zinc-coordination in the LIM domains. GST-pulldown experiments with other Lmo and Gata proteins indicates that PA207 can bind to a range of zinc finger proteins. Thus, PA207 and other cysteine-containing peptide aptamers for Lmo2 may form a class of general zinc finger inhibitors.

List inflammatory caspase proteins?

caspase-1 caspase-4 caspase-5

[25943872, 22195746, 21880711, 21051981, 20401456, 22895188, 20514521, 20401526, 24280500, 19927353, 20541850, 23215645]

Engagement of tumor necrosis factor receptor 1 signals two diametrically opposed pathways: survival-inflammation and cell death. An additional switch decides, depending on the cellular context, between caspase-dependent apoptosis and RIP kinase (RIPK)-mediated necrosis, also termed necroptosis. We explored the contribution of both cell death pathways in TNF-induced systemic inflammatory response syndrome (SIRS). Deletion of apoptotic executioner caspases (caspase-3 or -7) or inflammatory caspase-1 had no impact on lethal SIRS. However, deletion of RIPK3 conferred complete protection against lethal SIRS and reduced the amounts of circulating damage-associated molecular patterns. Pretreatment with the RIPK1 kinase inhibitor, necrostatin-1, provided a similar effect. These results suggest that RIPK1-RIPK3-mediated cellular damage by necrosis drives mortality during TNF-induced SIRS. RIPK3 deficiency also protected against cecal ligation and puncture, underscoring the clinical relevance of RIPK kinase inhibition in sepsis and identifying components of the necroptotic pathway that are potential therapeutic targets for treatment of SIRS and sepsis. INTRODUCTION: When apoptosis is disrupted, the transformed cells can survive, proliferate, and evolve into a malignancy. The strictly conserved caspase genes and the reliable experimental data clearly show that some caspases play a crucial role in apoptosis even if some of them have no apoptotic activity and others exhibit both apoptotic and nonapoptotic properties. Although caspase-2 belongs to initiator caspases, its normal role remains unclear. Experimental studies have shown that it is primarily necessary for the execution of apoptosis in mutagenic cells. Human caspase-5 is classified as an inflammatory caspase, although its substrate has not been identified yet. In this research, the activities of caspase-2 and caspase-5 have been estimated during the progression of human cervical malignancy. METHODS: The experimental material includes human cervical tissue samples (normal and pathological) and blood serum samples of the corresponding tissue donors, where enzyme activities have been measured colorimetrically. RESULTS: Both caspases' activities showed the highest increase, statistically significant (P < 0.01, by t test) compared with the controls, in the low-grade squamous intraepithelial lesion tissues. Caspase-2 of all pathological tissues was proved more active than the controls. Serum caspases' activities were significantly lower than those of the tissues. Serum caspase-2's activity in patients with low-grade squamous intraepithelial lesion stage showed no statistically significant increase compared with the controls. Serum caspase-5's activity of all patients with malignancy stages was presented elevated, whereas that of the serum of patients with cervical cancer had the highest activity (P < 0.01, by t test). CONCLUSIONS: The changes of caspase-2 and caspase-5 activities could be indicative of their involvement in the cervical malignancy mechanisms. Host protection against fungi depends on intact innate and adaptive immune responses. Consistently, fungal infections can cause systemic life-threatening diseases in immunocomprimised individuals, suffering e.g. from cancer or AIDS. Recent work has uncovered essential roles for the spleen tyrosine kinase (SYK) and the cytosolic NLRP3 inflammasome for Interleukin-1beta (IL-1beta) production in innate antifungal immunity. Upon fungal infection, SYK is activated by several C-type lectin pattern recognition receptors on myeloid cells. Subsequently, SYK signals for the production of reactive oxygen species and for gene transcription to induce pro-inflammatory factors, including pro-IL-1beta to initiate antifungal responses. Mature IL-1beta production additionally requires cleavage of the pro-IL-1beta precursor protein by the inflammatory caspase-1 which is controlled within the NLRP3 inflammasome. Here, we discuss how SYK signaling cooperates with the NLRP3 inflammasome for IL-1beta production in antifungal immunity. Inflammasomes are cytosolic multiprotein complexes assembled by intracellular nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs) and they initiate innate immune responses to invading pathogens and danger signals by activating caspase-1 (ref. 1). Caspase-1 activation leads to the maturation and release of the pro-inflammatory cytokines interleukin (IL)-1β and IL-18, as well as lytic inflammatory cell death known as pyroptosis. Recently, a new non-canonical inflammasome was described that activates caspase-11, a pro-inflammatory caspase required for lipopolysaccharide-induced lethality. This study also highlighted that previously generated caspase-1 knockout mice lack a functional allele of Casp11 (also known as Casp4), making them functionally Casp1 Casp11 double knockouts. Previous studies have shown that these mice are more susceptible to infections with microbial pathogens, including the bacterial pathogen Salmonella enterica serovar Typhimurium (S. typhimurium), but the individual contributions of caspase-1 and caspase-11 to this phenotype are not known. Here we show that non-canonical caspase-11 activation contributes to macrophage death during S. typhimurium infection. Toll-like receptor 4 (TLR4)-dependent and TIR-domain-containing adaptor-inducing interferon-β (TRIF)-dependent interferon-β production is crucial for caspase-11 activation in macrophages, but is only partially required for pro-caspase-11 expression, consistent with the existence of an interferon-inducible activator of caspase-11. Furthermore, Casp1(-/-) mice were significantly more susceptible to infection with S. typhimurium than mice lacking both pro-inflammatory caspases (Casp1(-/-) Casp11(-/-)). This phenotype was accompanied by higher bacterial counts, the formation of extracellular bacterial microcolonies in the infected tissue and a defect in neutrophil-mediated clearance. These results indicate that caspase-11-dependent cell death is detrimental to the host in the absence of caspase-1-mediated innate immunity, resulting in extracellular replication of a facultative intracellular bacterial pathogen. Although it is conventionally regarded as an inflammatory caspase, recent studies have shown that caspase-4 plays a role in induction of apoptosis by endoplasmic reticulum (ER) stress. We report here that activation of caspase-4 is also involved in induction of apoptosis by TNF-related apoptosis-inducing ligand (TRAIL) in human melanoma cells. Treatment with TRAIL resulted in activation of caspase-4. This appeared to be mediated by caspase-3, in that caspase-4 was activated later than caspase-8, -9, and -3, and that inhibition of caspase-3 blocked TRAIL-induced caspase-4 activation. Notably, TRAIL triggered ER stress in melanoma cells as shown by up-regulation of the GRP78 protein and the spliced form of XBP-1 mRNA. This seemed to be necessary for activation of caspase-4, as activation of caspase-3 by agents that did not trigger ER stress did not cause activation of caspase-4. Importantly, inhibition of caspase-4 also partially blocked caspase-3 activation, suggesting that activation of caspase-4 may be positive feed-back mechanism to further enhance caspase-3 activation. Collectively, these results show that activation of caspase-4 contributes to TRAIL-induced apoptosis and is associated with induction of ER stress by TRAIL in melanoma cells, and may have important implications for improving therapeutic efficacies of TRAIL in melanoma. INTRODUCTION: Infections with fungi can cause systemic life-threatening diseases in immunocompromised individuals like cancer or AIDS patients. Recent work has uncovered essential roles for C-type lectin pattern recognition receptors, spleen tyrosine kinase (SYK) and the cytosolic NLRP3 inflammasome in innate antifungal immunity. Upon fungal infection, SYK is activated by several ITAM-containing or ITAM-coupled C-type lectin receptors on myeloid cells leading to the production of pro-inflammatory cytokines including IL-1beta to initiate antifungal responses. Mature IL-1beta production requires in addition to the synthesis of pro-IL-1beta a cleavage of the precursor protein by the inflammatory Caspase-1 which is controlled within the NLRP3 inflammasome. SCOPE: Here, we discuss how ITAM receptor signaling and NLRP3 cooperate for the induction of antifungal immunity. Human beings are constantly exposed to pathogens. The innate immune system is the first line of defense against microbes. It has evolved to recognize conserved microbial motifs (PAMP or pathogen-associated molecular patterns) thanks to a limited array of receptors termed pattern recognition receptors (PRR). Upon activation, most PRR trigger a transcriptional response leading to neosynthesis of hundreds of genes. In contrast, engagement of various PRR in the recently identified inflammasome complexes lead to activation of a cysteine protease, caspase-1. This inflammatory caspase has a dual activity: it triggers the release of very potent proinflammatory cytokines IL-1β and IL-18 and, an hyperinflammatory cell death termed pyroptosis. In this review, we describe the inflammasome receptors and their ligands, the molecular mechanisms leading to the assembly of this innate immune platform and the role of the inflammasome during viral and bacterial infections. INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is a worldwide burden and a major cause of death. The disease is accompanied by chronic inflammation and increased cellular turnover that is partly due to an overwhelming induction of apoptosis. In this study, we hypothesized that systemic markers of apoptosis are altered in patients with mild-to-severe COPD. MATERIALS AND METHODS: A total number of 64 patients and controls were enrolled in the study. Lung function parameters of all groups (nonsmoker, healthy smoker, COPD GOLD I&II, COPD GOLD III&IV) were evaluated at the time of inclusion. Enzyme-linked immunosorbent assays were used to quantify protein levels in serum samples. RESULTS: Serum contents of apoptotic end-products caspase-cleaved cytokeratin-18 and histone-associated-DNA-fragments were increased in patients with COPD, whereas anti-inflammatory soluble ST2 showed a peak in patients with COPD I&II (P=0.031) compared to healthy smokers. Levels of pro-inflammatory caspase-1/ ICE correlated significantly with the number of pack years (R=0.337; P=0.007). DISCUSSION: Our results indicate a systemic release of apoptosis-specific proteins as markers for increased cellular turnover accompanied by progression of COPD. Furthermore, soluble ST2 seems to have a critical role in the anti-inflammatory regulatory mechanism at early stages of the disease. Inflammasomes are cytosolic multiprotein complexes that assemble in response to a variety of infectious and noxious insults. Inflammasomes play a critical role in the initiation of innate immune responses, primarily by serving as platforms for the activation of inflammatory caspase proteases. One such caspase, CASPASE-1 (CASP1), initiates innate immune responses by cleaving pro-IL-1β and pro-IL-18, leading to their activation and release. CASP1 and another inflammatory caspase termed CASP11 can also initiate a rapid and inflammatory form of cell death termed pyroptosis. Several distinct inflammasomes have been described, each of which contains a unique sensor protein of the NLR (nucleotide-binding domain, leucine-rich repeat-containing) superfamily or the PYHIN (PYRIN and HIN-200 domain-containing) superfamily. Here we describe the surprisingly diverse mechanisms by which NLR/PYHIN proteins sense bacteria and initiate innate immune responses. We conclude that inflammasomes represent a highly adaptable scaffold ideally suited for detecting and initiating rapid innate responses to diverse and rapidly evolving bacteria.

List invertebrates where ultraconserved elements have been identified.

Ultraconserved elements have been identified in the following genomes of invertebrates: tunicates, diptera, worm and yeast.

[23217155, 23393190, 16697139, 16024819, 17114937, 18514361, 15899965]

BACKGROUND: Ultraconserved elements of DNA have been identified in vertebrate and invertebrate genomes. These elements have been found to have diverse functions, including enhancer activities in developmental processes. The evolutionary origins and functional roles of these elements in cellular systems, however, have not yet been determined. RESULTS: Here, we identified a wide range of ultraconserved elements common to distant species, from primitive aquatic organisms to terrestrial species with complicated body systems, including some novel elements conserved in fruit fly and human. In addition to a well-known association with developmental genes, these DNA elements have a strong association with genes implicated in essential cell functions, such as epigenetic regulation, apoptosis, detoxification, innate immunity, and sensory reception. Interestingly, we observed that ultraconserved elements clustered by sequence similarity. Furthermore, species composition and flanking genes of clusters showed lineage-specific patterns. Ultraconserved elements are highly enriched with binding sites to developmental transcription factors regardless of how they cluster. CONCLUSION: We identified large numbers of ultraconserved elements across distant species. Specific classes of these conserved elements seem to have been generated before the divergence of taxa and fixed during the process of evolution. Our findings indicate that these ultraconserved elements are not the exclusive property of higher modern eukaryotes, but rather transmitted from their metazoan ancestors. Co-option of cis-regulatory modules has been suggested as a mechanism for the evolution of expression sites during development. However, the extent and mechanisms involved in mobilization of cis-regulatory modules remains elusive. To trace the history of non-coding elements, which may represent candidate ancestral cis-regulatory modules affirmed during chordate evolution, we have searched for conserved elements in tunicate and vertebrate (Olfactores) genomes. We identified, for the first time, 183 non-coding sequences that are highly conserved between the two groups. Our results show that all but one element are conserved in non-syntenic regions between vertebrate and tunicate genomes, while being syntenic among vertebrates. Nevertheless, in all the groups, they are significantly associated with transcription factors showing specific functions fundamental to animal development, such as multicellular organism development and sequence-specific DNA binding. The majority of these regions map onto ultraconserved elements and we demonstrate that they can act as functional enhancers within the organism of origin, as well as in cross-transgenesis experiments, and that they are transcribed in extant species of Olfactores. We refer to the elements as 'Olfactores conserved non-coding elements'. We have explored the distributions of fully conserved ungapped blocks in genome-wide pair-wise alignments of recently completed species of Drosophila: D. melanogaster, D. yakuba, D. ananassae, D. pseudoobscura, D. virilis, and D. mojavensis. Based on these distributions we have found that nearly every functional sequence category possesses its own distinctive conservation pattern, sometimes independent of the overall sequence conservation level. In the coding and regulatory regions, the ungapped blocks were longer than in introns, UTRs, and nonfunctional sequences. At the same time, the blocks in the coding regions carried a 3N + 2 signature characteristic of synonymous substitutions in the third-codon position. Larger block sizes in transcription regulatory regions can be explained by the presence of conserved arrays of binding sites for transcription factors. We also have shown that the longest ungapped blocks, or "ultraconserved" sequences, are associated with specific gene groups, including those encoding ion channels and components of the cytoskeleton. We discuss how restraining conservation patterns may help in mapping functional sequence categories and improve genome annotation. We have conducted a comprehensive search for conserved elements in vertebrate genomes, using genome-wide multiple alignments of five vertebrate species (human, mouse, rat, chicken, and Fugu rubripes). Parallel searches have been performed with multiple alignments of four insect species (three species of Drosophila and Anopheles gambiae), two species of Caenorhabditis, and seven species of Saccharomyces. Conserved elements were identified with a computer program called phastCons, which is based on a two-state phylogenetic hidden Markov model (phylo-HMM). PhastCons works by fitting a phylo-HMM to the data by maximum likelihood, subject to constraints designed to calibrate the model across species groups, and then predicting conserved elements based on this model. The predicted elements cover roughly 3%-8% of the human genome (depending on the details of the calibration procedure) and substantially higher fractions of the more compact Drosophila melanogaster (37%-53%), Caenorhabditis elegans (18%-37%), and Saccharaomyces cerevisiae (47%-68%) genomes. From yeasts to vertebrates, in order of increasing genome size and general biological complexity, increasing fractions of conserved bases are found to lie outside of the exons of known protein-coding genes. In all groups, the most highly conserved elements (HCEs), by log-odds score, are hundreds or thousands of bases long. These elements share certain properties with ultraconserved elements, but they tend to be longer and less perfectly conserved, and they overlap genes of somewhat different functional categories. In vertebrates, HCEs are associated with the 3' UTRs of regulatory genes, stable gene deserts, and megabase-sized regions rich in moderately conserved noncoding sequences. Noncoding HCEs also show strong statistical evidence of an enrichment for RNA secondary structure. In a recent study that identified highly evolutionary conserved sequences in three genomes of Diptera species we described an ultraconserved element found at an internal exon-intron junction of the Drosophila melanogaster homothorax (hth) gene that appeared to be involved in the control of hth pre-mRNA splicing. We also discussed a possible role of RNA secondary structure at this site in the regulation of hth pre-mRNA splicing. In this report we identify a shorter evolutionary conserved intronic element within the hth gene that is located downstream of the first element and has sequence complementarity to it. We demonstrate that intramolecular interactions between these two elements would give rise to alternative RNA secondary structures, which in turn may result in differential control of homothorax pre-mRNA splicing. We also provide additional comparative genomic data from several newly available insect genomes supporting our original conclusion that these conserved elements are important in the post-transcriptional regulation of homothorax gene expression in Diptera. Aligning and comparing genomic sequences enables the identification of conserved sequence signatures and can enrich for coding and noncoding functional regions. In vertebrates, the comparison of human and rodent genomes and the comparison of evolutionarily distant genomes, such as human and pufferfish, have identified specific sets of 'ultraconserved' sequence elements associated with the control of early development. However, is this just the tip of a 'conservation iceberg' or do these sequences represent a specific class of regulatory element? Studies on the zebrafish phox2b gene region and the ENCODE project suggest that many regulatory elements are not highly conserved, posing intriguing questions about the relationship between noncoding sequence conservation and function and the evolution of regulatory sequences. Recently, we identified a large number of ultraconserved (uc) sequences in noncoding regions of human, mouse, and rat genomes that appear to be essential for vertebrate and amniote ontogeny. Here, we used similar methods to identify ultraconserved genomic regions between the insect species Drosophila melanogaster and Drosophila pseudoobscura, as well as the more distantly related Anopheles gambiae. As with vertebrates, ultraconserved sequences in insects appear to occur primarily in intergenic and intronic sequences, and at intron-exon junctions. The sequences are significantly associated with genes encoding developmental regulators and transcription factors, but are less frequent and are smaller in size than in vertebrates. The longest identical, nongapped orthologous match between the three genomes was found within the homothorax (hth) gene. This sequence spans an internal exon-intron junction, with the majority located within the intron, and is predicted to form a highly stable stem-loop RNA structure. Real-time quantitative PCR analysis of different hth splice isoforms and Northern blotting showed that the conserved element is associated with a high incidence of intron retention in hth pre-mRNA, suggesting that the conserved intronic element is critically important in the post-transcriptional regulation of hth expression in Diptera.

Which gene is most commonly associated with severe congenital and cyclic neutropenia?

Neutrophil elastase gene (ELANE) mutations are responsible for the majority of cases of severe congenital neutropenia (SCN) and cyclic neutropenia (CN).

[19415009, 12483111, 17761833, 11543999, 23463630, 19057199, 11001877, 14962902, 17107353, 20582973, 17053055]

PURPOSE: Three familial cases of each of severe congenital neutropenia (SCN) and cyclic neutropenia (CN) in addition to 3 sporadic cases of SCN were analyzed for neutrophil elastase (Ela2) gene mutation. The contents of the neutrophil-specific granule proteins cathelicidin antimicrobial peptide and neutrophil gelatinase-associated lipocalin were also analyzed in SCN. METHODS: Genomic DNA was extracted from the patients' peripheral blood or bone marrow, and the coding sequence of the Ela2 gene was amplified by polymerase chain reaction and subjected to direct sequencing. The contents of antimicrobial peptides were analyzed by flow cytometry. RESULTS: Three cases of familial SCN (P13L, R52P, and S97L), 2 of familial CN (W212stop and P110L), and 1 of sporadic SCN (V72M) were shown to have heterozygous mutations in the Ela2 gene. W212stop found in a familial CN case was a novel mutation of Ela2. Prophylactic treatment for growth factors or antibiotic prophylaxis against bacterial infection was useful for lowering the frequency of infectious episodes. Adult patients tended to have less frequent infections compared with minors in the same family. The contents of both cathelicidin antimicrobial peptide and neutrophil gelatinase-associated lipocalin were significantly reduced in SCN compared with healthy controls. CONCLUSIONS: Prophylaxis by growth factor or antibiotics is useful for decreasing risks of bacterial infections in SCN and CN. Adults were likely to have less frequent infections than children in familial cases of SCN and CN with the same mutation of Ela2. Two forms of inherited deficiency of neutrophil numbers are cyclic hematopoiesis and severe congenital neutropenia. In cyclic hematopoiesis, neutrophil counts oscillate opposite monocytes in a 3-week cycle. Severe congenital neutropenia consists of static neutropenia and a predisposition to myelodysplasia and acute myelogenous leukemia. All cases of cyclic neutropenia and most cases of severe congenital neutropenia result from heterozygous germline mutations in the gene encoding neutrophil elastase, ela2. Recent work extends the list of neutropenia genes to include WASp, Gfi-1, adaptin, and tafazzin. Studies of mosaic patients suggest that ela2 mutations act in a cell-autonomous fashion. A hypothetical feedback circuit potentially interconnects these genes. Genetic dissection of signaling in model organisms along with experimental hematology implicate C/EPBepsilon, RUNX1/AML1, Notch family members, LEF1, and Cdc42 as additional nodes in this pathway. The authors propose that neutrophil elastase acts as an inhibitor of myelopoiesis, substantiating a chalone hypothesis proposed many years ago. Severe congenital neutropenia (SCN) is an inborn disorder of granulopoiesis. Mutations of the ELA2 gene encoding neutrophil elastase (NE) are responsible for most cases of SCN and cyclic neutropenia (CN), a related but milder disorder of granulopoiesis. However, the mechanisms by which these mutations disrupt granulopoiesis are unclear. We hypothesize that the ELA2 mutations result in the production of misfolded NE protein, activation of the unfolded protein response (UPR), and ultimately apoptosis of granulocytic precursors. Expression of mutant NE but not wild-type NE strongly induced BiP/GRP78 mRNA expression and XBP1 mRNA splicing, 2 classic markers of the UPR. The magnitude of UPR activation by a specific ELA2 mutation correlated with its associated clinical phenotype. Consistent with the UPR model, expression of mutant NE in primary human granulocytic precursors increased expression of CHOP (DDITS) and induced apoptosis in a protease-independent fashion. Most strikingly, UPR activation and decreased NE protein expression were detected in primary granulocytic precursors from SCN patients. Collectively, these data provide strong support for a UPR model of SCN disease pathogenesis and place SCN in a growing list of human diseases caused by misfolded proteins. Severe neutropenia disorders are characterized by extremely low levels of peripheral blood neutrophils, a maturation block of bone marrow progenitor cells and recurring severe bacterial and fungal infections. Recent reports indicated that severe neutropenia is a consequence of an impaired survival and abnormal cell cycle progression of myeloid progenitor cells in both cyclic and severe congenital neutropenia. Mutations in the neutrophil elastase gene were identified in all patients with cyclic neutropenia and most of the patients with severe congenital neutropenia. We hypothesize that expression of mutant neutrophil elastase protein results in deregulation of intracellular activity and premature cell death of myeloid-committed progenitor cells in these disorders, resulting in the lack of peripheral blood neutrophils. The potential molecular mechanisms of mutant-protein-mediated neutropenia is discussed. Neutrophil elastase gene (ELANE) mutations are responsible for the majority of cases of severe congenital neutropenia (CN) and cyclic neutropenia (CyN). We screened CN (n = 395) or CyN (n = 92) patients for ELANE mutations and investigated the impact of mutations on mRNA expression, protein expression, and activity. We found 116 different mutations in 162 (41%) CN patients and 26 in 51 (55%) CyN patients, 69 of them were novel. CyN-associated mutations were predicted to be more benign than CN-associated mutations, but the mutation severity largely overlapped. The frequency of acquired CSF3R mutations, malignant transformation, and the need for hematopoietic stem cell transplantation was significantly higher in CN patients with ELANE mutation than in ELANE mutation negative patients. Cellular elastase activity was reduced in neutrophils from CN/CyN patients, irrespective of the mutation status. In CN, enzymatic activity was significantly lower in patients with ELANE mutations compared with those with wild-type ELANE. Despite differences in the spectrum of mutations in CN or CyN, type or localization of mutation only partially determine the clinical phenotype. Specific ELANE mutations have limited predictive value for leukemogenesis; the risk for leukemia was correlated with disease severity rather than with occurrence of an ELANE mutation. PURPOSE OF REVIEW: Severe congenital neutropenia has been a well known hematological condition for over 50 years. Over this long period of time, the variable genetic causes and associated sequelae of the disease have been ascertained, and successful treatment strategies developed. Over the past 2 years, however, new studies have added greatly to our understanding of the molecular basis of the disease, details of which are presented in this review. RECENT FINDINGS: Recent studies have elucidated a role for the unfolded protein response in mediating the pathogenic effects of ELA2 mutations, the most common mutation in severe congenital neutropenia (SCN) as well as cyclic neutropenia. Genetic lesions in HAX1 have also been identified in the original Kostmann pedigree representing the autosomal recessive form of SCN. An emerging theme is the convergence of these and other genetic lesions underlying SCN in enhancing neutrophil apoptosis. Other studies have revealed the importance of multiple independent mutations in these and other genes in SCN. Finally, the key role for signal transducer and activator of transcription 5 in mediating the effects of granulocyte colony-stimulating factor receptor truncation mutations in the development of myelodysplastic syndrome/acute myeloid leukemia following SCN has been elucidated. SUMMARY: As the full spectrum of molecular mutations causing neutropenia emerges, it is becoming possible to differentiate patients into subtypes with different prognoses, for whom tailored therapies are indicated. Heterozygous mutations of the gene encoding neutrophil elastase (ELA2) have been associated with cyclic neutropenia (CN) and severe congenital neutropenia (SCN). To date, 30 different mutations have been reported, but no correlation has been found with the degree of neutropenia. To address this issue, we analyzed the clinical, hematologic, and molecular characteristics of 81 unrelated patients with SCN (n = 54) or CN (n = 27). We identified mutations in 31 patients, two thirds of whom had sporadic forms. Familial cases were consistent with dominant inheritance. Seventeen novel mutations were identified, showing that the mutational spectrum encompasses not only the region encoding the mature enzyme but also the prodomains and promoter region. Genotype-phenotype analysis strongly suggested that ELA2 mutations correlate with more severe expression of neutropenia, specifically in patients diagnosed with SCN. This study underlines the importance of ELA2 molecular screening to identify patients who may be at particular risk of severe bacterial infections and/or acute myeloid leukemia/myelodysplasia. By phenotypic analysis of affected relatives and carriers of the same ELA2 mutations, we showed that the expression of neutropenia in CN and SCN may be either homogeneous or variable according to the type of mutations, suggesting different pathogenetic mechanisms. Proteases and their serpin inhibitors are abundantly expressed in haemopoietic and peripheral blood cells. There is, however, relatively little information about the role played by serpins in the control of protease activity within these cells and in the pericellular region. The observation that mutations in the neutrophil elastase gene, which cause cyclic and severe congenital neutropenia, are associated with protease maldistribution gives some clue as to the potential importance of inhibitor proteins. To begin to address the role of protease/inhibitor balance in blood cells we used reverse transcription polymerase chain reaction to examine protease and serpin gene expression in mature peripheral blood cells, differentiating haemopoietic progenitors, leukaemic blasts and haemopoietic cell lines. The results demonstrate stage-specific expression of proteases together with widespread expression of intra- and extra-cellular serpins. The elastase inhibitors monocyte neutrophil elastase inhibitor (MNEI) and antitrypsin (AT) showed overlapping expression. MNEI is predominantly expressed in early haemopoietic progenitors while antitrypsin is mainly expressed in more mature myeloid precursors, peripheral blood granulocytes and mononuclear cells. Our results give an overall picture of serpin and protease gene expression and draws attention to the potential importance of elastase regulators at all stages of myelopoiesis. BACKGROUND: Cyclic neutropenia (CN) and severe congenital neutropenia (SCN) are disorders of neutrophil production that differ markedly in disease severity. Mutations of the ELANE gene (the symbol recently replacing ELA2) are considered largely responsible for most cases of CN and SCN, but specific mutations are typically associated with one or the other. PROCEDURE: We performed ELANE genotyping on all individuals and paternal sperm in an SCN kindred with eight SCN progeny of a sperm donor and six different mothers. RESULTS: One patient with CN had the same S97L ELANE mutation as seven patients with the SCN phenotype. The mutant allele was detected in the donor's spermatozoa, representing 18% of the ELANE gene pool, but not in DNA from his lymphocytes, neutrophils, or buccal mucosa, indicating gonadal mosaicism. CONCLUSIONS: The coexistence of CN and SCN phenotypes in this kindred with a shared paternal haplotype strongly suggests both a role for modifying genes in determination of congenital neutropenia disease phenotypes, and the classification of CN and SCN within a spectrum of phenotypes expressing varying degrees of the same disease process. Mutations in ELA2 encoding the neutrophil granule protease, neutrophil elastase (NE), are the major cause of the 2 main forms of hereditary neutropenia, cyclic neutropenia and severe congenital neutropenia (SCN). Genetic evaluation of other forms of neutropenia in humans and model organisms has helped to illuminate the role of NE. A canine form of cyclic neutropenia corresponds to human Hermansky-Pudlak syndrome type 2 (HPS2) and results from mutations in AP3B1 encoding a subunit of a complex involved in the subcellular trafficking of vesicular cargo proteins (among which NE appears to be one). Rare cases of SCN are attributable to mutations in the transcriptional repressor Gfi1 (among whose regulatory targets also include ELA2). The ultimate biochemical consequences of the mutations are not yet known, however. Gene targeting of ELA2 has thus far failed to recapitulate neutropenia in mice. The cycling phenomenon and origins of leukemic transformation in SCN remain puzzling. Nevertheless, mutations in all 3 genes are capable of causing the mislocalization of NE and may also induce the unfolded protein response, suggesting that there might a convergent pathogenic mechanism focusing on NE.

what is the role of TGFbeta in cardiac regeneration after myocardial injury?

TGFβ is activated in the myocardium in response to injury and plays a crucial role in cardiac repair by suppressing inflammation while promoting myofibroblast phenotypic modulation and extracellular matrix deposition. In fact, upregulation of TGF-beta signaling promotes the formation of a myofibroblast-like phenotype. TGF-beta interacts with bone morphogenic protein and Wnt pathways to form a complex signaling network that is critical in regulating the fate choices of both stromal and tissue-specific resident stem cells, determining whether functional regeneration or the formation of scar tissue follows an injury. In addition, TGF-beta enhances the formation of cardiospheres and could potentially enhance the regenerative potential of adult cardiac progenitor cells.

[18832581, 21611174, 22982064, 23293297, 22765842, 18620057, 23270300, 23166366]

The regulation of valve interstitial cell (VIC) function in response to tissue injury and valve disease is not well understood. Because transforming growth factor-beta (TGF-beta) has been implicated in tissue repair, we tested the hypothesis that TGF-beta is a regulator of VIC activation and associated cell responses that occur during early repair processes. We used a well-characterized wound model that was created by mechanical denudation of a confluent VIC monolayer to study activation and repair 24 hours after wounding. VIC activation was demonstrated by immunofluorescent localization of alpha-smooth muscle actin (alpha-SMA), and alpha-SMA mRNA levels were quantified by real-time polymerase chain reaction. Proliferation and apoptosis were quantified by bromodeoxyuridine staining and terminal deoxynucleotidyl transferase dUTP nick end labeling, respectively. Repair was quantified by measuring VIC extension into the wound, and TGF-beta expression was shown by immunofluorescent localization of intracellular TGF-beta. Compared with nonwounded monolayers, VICs at the wound edge showed alpha-SMA staining, increased alpha-SMA mRNA content, elongation into the wound with stress fibers, proliferation, and apoptosis. VICs at the wound edge also showed increased TGF-beta and pSmad2/3 staining with co-expression of alpha-SMA. Addition of TGF-beta neutralizing antibody to the wound decreased VIC activation, alpha-SMA mRNA content, proliferation, apoptosis, wound closure rate, and stress fibers. Conversely, exogenous addition of TGF-beta to the wound increased VIC activation, proliferation, wound closure rate, and stress fibers. Thus, wounding activates VICs, and TGF-beta signaling modulates VIC response to injury. Fibroblasts are the predominant cell type in the cardiac interstitium. As the main matrix-producing cells in the adult mammalian heart, fibroblasts maintain the integrity of the extracellular matrix network, thus preserving geometry and function. Following myocardial infarction fibroblasts undergo dynamic phenotypic alterations and direct the reparative response. Due to their strategic location, cardiac fibroblasts serve as sentinel cells that sense injury and activate the inflammasome secreting cytokines and chemokines. During the proliferative phase of healing, infarct fibroblasts undergo myofibroblast transdifferentiation forming stress fibers and expressing contractile proteins (such as α-smooth muscle actin). Mechanical stress, transforming growth factor (TGF)-β/Smad3 signaling and alterations in the composition of the extracellular matrix induce acquisition of the myofibroblast phenotype. In the highly cellular and growth factor-rich environment of the infarct, activated myofibroblasts produce matrix proteins, proteases and their inhibitors regulating matrix metabolism. As the infarct matures, "stress-shielding" of myofibroblasts by the cross-linked matrix and growth factor withdrawal may induce quiescence and ultimately cause apoptotic death. Because of their critical role in post-infarction cardiac remodeling, fibroblasts are promising therapeutic targets following myocardial infarction. However, the complexity of fibroblast functions and the pathophysiologic heterogeneity of post-infarction remodeling in the clinical context discourage oversimplified approaches in clinical translation. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Cardiac Pathways of Differentiation, Metabolism and Contraction. Autologous cardiac progenitor cells (CPCs) isolated as cardiospheres (CSps) represent a promising candidate for cardiac regenerative therapy. A better understanding of the origin and mechanisms underlying human CSps formation and maturation is undoubtedly required to enhance their cardiomyogenic potential. Epithelial-to-mesenchymal transition (EMT) is a key morphogenetic process that is implicated in the acquisition of stem cell-like properties in different adult tissues, and it is activated in the epicardium after ischemic injury to the heart. We investigated whether EMT is involved in the formation and differentiation of human CSps, revealing that an up-regulation of the expression of EMT-related genes accompanies CSps formation that is relative to primary explant-derived cells and CSp-derived cells grown in a monolayer. EMT and CSps formation is enhanced in the presence of transforming growth factor β1 (TGFβ1) and drastically blocked by the type I TGFβ-receptor inhibitor SB431452, indicating that TGFβ-dependent EMT is essential for the formation of these niche-like 3D-multicellular clusters. Since TGFβ is activated in the myocardium in response to injury, our data suggest that CSps formation mimics an adaptive mechanism that could potentially be enhanced to increase in vivo or ex vivo regenerative potential of adult CPCs. Myocardial infarction is the most common cause of cardiac injury and results in acute loss of a large number of myocardial cells. Because the heart has negligible regenerative capacity, cardiomyocyte death triggers a reparative response that ultimately results in formation of a scar and is associated with dilative remodeling of the ventricle. Cardiac injury activates innate immune mechanisms initiating an inflammatory reaction. Toll-like receptor-mediated pathways, the complement cascade and reactive oxygen generation induce nuclear factor (NF)-kappaB activation and upregulate chemokine and cytokine synthesis in the infarcted heart. Chemokines stimulate the chemotactic recruitment of inflammatory leukocytes into the infarct, while cytokines promote adhesive interactions between leukocytes and endothelial cells, resulting in transmigration of inflammatory cells into the site of injury. Monocyte subsets play distinct roles in phagocytosis of dead cardiomyocytes and in granulation tissue formation through the release of growth factors. Clearance of dead cells and matrix debris may be essential for resolution of inflammation and transition into the reparative phase. Transforming growth factor (TGF)-beta plays a crucial role in cardiac repair by suppressing inflammation while promoting myofibroblast phenotypic modulation and extracellular matrix deposition. Myofibroblast proliferation and angiogenesis result in formation of highly vascularized granulation tissue. As the healing infarct matures, fibroblasts become apoptotic and a collagen-based matrix is formed, while many infarct neovessels acquire a muscular coat and uncoated vessels regress. Timely resolution of the inflammatory infiltrate and spatial containment of the inflammatory and reparative response into the infarcted area are essential for optimal infarct healing. Targeting inflammatory pathways following infarction may reduce cardiomyocyte injury and attenuate adverse remodeling. In addition, understanding the role of the immune system in cardiac repair is necessary in order to design optimal strategies for cardiac regeneration. Adult stem cells are activated to proliferate and differentiate during normal tissue homeostasis as well as in disease states and injury. This activation is a vital component in the restoration of function to damaged tissue via either complete or partial regeneration. When regeneration does not fully occur, reparative processes involving an overproduction of stromal components ensure the continuity of tissue at the expense of its normal structure and function, resulting in a "reparative disorder". Adult stem cells from multiple organs have been identified as being involved in this process and their role in tissue repair is being investigated. Evidence for the participation of mesenchymal stromal cells (MSCs) in the tissue repair process across multiple tissues is overwhelming and their role in reparative disorders is clearly demonstrated, as is the involvement of a number of specific signaling pathways. Transforming growth factor beta, bone morphogenic protein and Wnt pathways interact to form a complex signaling network that is critical in regulating the fate choices of both stromal and tissue-specific resident stem cells (TSCs), determining whether functional regeneration or the formation of scar tissue follows an injury. A growing understanding of both TSCs, MSCs and the complex cascade of signals regulating both cell populations have, therefore, emerged as potential therapeutic targets to treat reparative disorders. This review focuses on recent advances on the role of these cells in skeletal muscle, heart and lung tissues.

List two chemotherapeutic agents that are used for treatment of Subependymal Giant Cell Astrocytoma

Everolimus and rapamycin are chemotherapeutic agents that are used for treatment of Subependymal Giant Cell Astrocytoma.

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The authors present a 21-year-old woman who has been receiving rapamycin for 5 months for bilateral subependymal giant cell astrocytomas. The patient was started at a dose of 0.2 mg/kg/day. Levels were maintained between 11 and 13 ng/mL. Magnetic resonance imaging of the brain 2(1/2) months after initiating rapamycin demonstrated a decrease in size of both astrocytomas (11 to 7.5 mm on the right and 8 to 5 mm on the left). Further studies are needed with prolonged observation to confirm these findings, determine the length of necessary treatment, and evaluate recurrence risk after discontinuation of rapamycin. INTRODUCTION: Better understanding of aberrantly active molecular pathways in tumors offers potential to develop more specific and less toxic therapies. Abnormal mammalian target of rapamycin (mTOR) complex signaling and defects in TSC1 and TSC2 have been associated with the development of subependymal giant cell astrocytomas (SEGAs) in tuberous sclerosis complex (TSC) patients. Recently, mTOR inhibitors such as everolimus have shown encouraging benefit for patients with SEGAs. AREAS COVERED: The authors discuss a molecular genetic pathway linked with TSC, specifically the role of two proteins whose functional absence is responsible for most SEGA tumors that arise in TSC patients. The authors also examine the rationale for targeted agents against this pathway therapeutically and describe the clinical evidence underlying the FDA approval of everolimus for patients with inoperable SEGAs. EXPERT OPINION: Everolimus (Afinitor) selectively targets a molecular defect of SEGAs in TSC patients. Although surgery is effective, most SEGAs recur. An agent that inhibits an underlying molecular abnormality represents a particularly attractive therapeutic option for patients with inoperable or recurrent tumors. Studies are also underway to assess everolimus in treating other sequelae of TSC, and other gliomas. Finally, additional research aimed at better understanding aberrant cell signaling pathways may lead to the development of more effective therapeutics. Everolimus (RAD001), a mTOR inhibitor, was initially used as an immunosuppressant in organ transplant patients; however, it also has significant antineoplastic properties. In patients with subependymal giant cell astrocytomas (SEGAs) associated with tuberous sclerosis complex who are not candidates for surgery, single-agent everolimus has demonstrated the ability to significantly reduce SEGA volume with good tolerability. In the Phase III, randomized, placebo-controlled trial, everolimus was associated with a SEGA response rate of 35% compared with 0% in the placebo group. The most common adverse events in clinical trials were stomatitis/mouth ulceration and upper respiratory tract infections, and most adverse events were grade 1 or 2; grade 4 events were rare. OBJECTIVES: To evaluate the efficacy and side effects of oral mammalian target of rapamycin (mTOR) inhibitors in children and adolescents with tuberous sclerosis complex (TSC) and intractable epilepsy or subependymal giant cell astrocytoma (SEGA). STUDY DESIGN: Single-center series of 13 children and adolescents with TSC who received sirolimus or everolimus (mTOR inhibitors). The anticonvulsant response was evaluated in 7 patients with TSC and refractory seizures. Six patients with SEGAs were treated with either sirolimus or everolimus for nonsurgical management. SEGA volumes were assessed longitudinally using 1.5-T magnetic resonance imaging. RESULTS: Of the intractable seizure group (7 patients), 1 patient had >90% reduction, 4 had 50%-90% reduction, and 2 had <50% reduction. Three reported subjective improvements in learning. By 12 months of treatment, there were statistically significant reductions in the SEGA volumes in 4 patients who received mTOR inhibitors (P < .04). The mean SEGA volume after 6 months of treatment was 2.18 cm(3), which represents 33% reduction in the mean baseline volume of 3.26 cm(3). The mTOR inhibitors were well tolerated. Adverse effects include dyslipidaemia (3 of 13), gingivitis (1 of 13), anorexia (1 of 13), and mild gastrointestinal side effects (1 of 13). CONCLUSION: This case series suggests that mTOR inhibitors can improve seizures in those with TSC and refractory epilepsy. They are also an effective treatment for reducing the volume of SEGAs in patients with TSC not amenable to surgery with an acceptable side effect profile. BACKGROUND: Neurosurgical resection is the standard treatment for subependymal giant-cell astrocytomas in patients with the tuberous sclerosis complex. An alternative may be the use of everolimus, which inhibits the mammalian target of rapamycin, a protein regulated by gene products involved in the tuberous sclerosis complex. METHODS: Patients 3 years of age or older with serial growth of subependymal giant-cell astrocytomas were eligible for this open-label study. The primary efficacy end point was the change in volume of subependymal giant-cell astrocytomas between baseline and 6 months. We gave everolimus orally, at a dose of 3.0 mg per square meter of body-surface area, to achieve a trough concentration of 5 to 15 ng per milliliter. RESULTS: We enrolled 28 patients. Everolimus therapy was associated with a clinically meaningful reduction in volume of the primary subependymal giant-cell astrocytoma, as assessed on independent central review (P<0.001 for baseline vs. 6 months), with a reduction of at least 30% in 21 patients (75%) and at least 50% in 9 patients (32%). Marked reductions were seen within 3 months and were sustained. There were no new lesions, worsening hydrocephalus, evidence of increased intracranial pressure, or necessity for surgical resection or other therapy for subependymal giant-cell astrocytoma. Of the 16 patients for whom 24-hour video electroencephalography data were available, seizure frequency for the 6-month study period (vs. the previous 6-month period) decreased in 9, did not change in 6, and increased in 1 (median change, -1 seizure; P=0.02). The mean (±SD) score on the validated Quality-of-Life in Childhood Epilepsy questionnaire (on which scores can range from 0 to 100, with higher scores indicating a better quality of life) was improved at 3 months (63.4±12.4) and 6 months (62.1±14.2) over the baseline score (57.8±14.0). Single cases of grade 3 treatment-related sinusitis, pneumonia, viral bronchitis, tooth infection, stomatitis, and leukopenia were reported. CONCLUSIONS: Everolimus therapy was associated with marked reduction in the volume of subependymal giant-cell astrocytomas and seizure frequency and may be a potential alternative to neurosurgical resection in some cases, though long-term studies are needed. (Funded by Novartis; ClinicalTrials.gov number, NCT00411619.). BACKGROUND: Everolimus, an orally administered rapamycin analogue, inhibits the mammalian target of rapamycin (mTOR), a highly conserved intracellular serine-threonine kinase that is a central node in a network of signaling pathways controlling cellular metabolism, growth, survival, proliferation, angiogenesis, and immune function. Everolimus has demonstrated substantial clinical benefit in randomized, controlled, phase III studies leading to approval for the treatment of advanced renal cell carcinoma, advanced neuroendocrine tumors of pancreatic origin, renal angiomyolipoma and subependymal giant-cell astrocytoma associated with tuberous sclerosis complex, as well as advanced hormone-receptor-positive (HR(+)) and human epidermal growth factor receptor-2-negative advanced breast cancer. MATERIALS AND METHODS: We discuss clinically relevant everolimus-related adverse events from the phase III studies, including stomatitis, noninfectious pneumonitis, rash, selected metabolic abnormalities, and infections, with focus on appropriate clinical management of these events and specific considerations in patients with breast cancer. RESULTS: The majority of adverse events experienced during everolimus therapy are of mild to moderate severity. The safety profile and protocols for toxicity management are well established. The class-effect adverse event profile observed with everolimus plus endocrine therapy in breast cancer is (as expected) distinct from that of endocrine therapy alone, but is similar to that observed with everolimus in other solid tumors. Information gained from the experience in other carcinomas on prompt diagnosis and treatments to optimize drug exposure, treatment outcomes, and patients' quality of life also applies to the patient population with advanced breast cancer. CONCLUSIONS: As with all orally administered agents, education of both physicians and patients in the management of adverse events for patients receiving everolimus is critical to achieving optimal exposure and clinical benefit. Active monitoring for early identification of everolimus-related adverse events combined with aggressive and appropriate intervention should lead to a reduction in the severity and duration of the event. BACKGROUND: Brain subependymal giant cell astrocytomas (SEGAs) in patients with tuberous sclerosis have been reported to respond to everolimus. METHODS: A 15-year-old male patient with intractable seizures and multiple SEGAs of the brain developed leptomeningeal enhancement and multiple metastatic, histologically confirmed SEGAs of the spinal cord. He received daily everolimus at a dose of 3 mg/m for 6 weeks, which was then increased to 6 mg/m. RESULTS: Magnetic resonance image of the brain and spine showed significant reduction in the size of SEGAs after 6 weeks of treatment. The patient has remained free of progression for 24 months. Additional benefits included: excellent seizure control, decrease in the size of cardiac rhabdomyomas, and improved quality of life. CONCLUSIONS: We describe a rare case of metastatic SEGA, which was successfully treated with everolimus. BACKGROUND: Tuberous sclerosis complex (TSC) is characterized by benign tumours in multiple organs, including the brain, kidneys, skin, lungs and heart. Our objective was to evaluate everolimus, an mTOR inhibitor, in the treatment of angiomyolipoma in patients with subependymal giant cell astrocytoma (SEGA) associated with TSC. METHODS: EXamining everolimus In a Study of Tuberous Sclerosis Complex-1 (NCT00789828), a prospective, double-blind, randomized, placebo-controlled, Phase 3 study, examined everolimus in treating SEGA associated with TSC. Patients with serial SEGA growth from pre-baseline to baseline scans were randomly assigned (2:1) to receive 4.5 mg/m(2)/day everolimus (target blood trough: 5-15 ng/mL; n = 78) or placebo (n = 39). Angiomyolipoma response rates were analysed in patients (n = 44) with target baseline angiomyolipoma lesions (≥1 angiomyolipoma; longest diameter ≥1.0 cm). An angiomyolipoma response rate, defined as the proportion of patients with confirmed angiomyolipoma response, was assessed by kidney CT or MRI screening at baseline, at 12, 24 and 48 weeks and annually. RESULTS: Angiomyolipoma response rates were 53.3% (16/30) and 0% (0/14) for everolimus- and placebo-treated patients, respectively. Angiomyolipoma reductions ≥50% in the sum of volumes of all target lesions were seen only in everolimus-treated patients (56.5, 78.3 and 80.0%) compared with placebo-treated patients (0% at each time point) at Weeks 12, 24 and 48, respectively. Greater percentages of everolimus-treated patients had angiomyolipoma reductions ≥30% at these same time points (82.6, 100 and 100% versus 8.3, 18.2 and 16.7% for everolimus versus placebo, respectively). CONCLUSIONS: Everolimus showed efficacy in reducing angiomyolipoma lesion volume in patients with SEGA associated with TSC.The trial is registered with ClinicalTrials.gov, number NCT00789828; http://clinicaltrials.gov/ct2/show/NCT00789828?term=EXIST-1&rank=1. Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by inactivating mutations in either the TSC1 or TSC2 genes. It is characterized by the development of multiple, benign tumors in several organs throughout the body. Lesions occur in the brain, kidneys, heart, liver, lungs, and skin and result in seizures and epilepsy, mental retardation, autism, and renal and pulmonary organ system dysfunction, as well as other complications. Elucidation of the molecular pathways and etiological factors responsible for causing TSC has led to a paradigm shift in the management and treatment of the disease. TSC1 or TSC2 mutations lead to constitutive upregulation of the mammalian target of rapamycin pathway, which affects many cellular processes involved in tumor growth. By targeting mammalian target of rapamycin with everolimus, an orally active rapamycin derivative, clinically meaningful and statistically significant reductions in tumor burden have been achieved for the main brain (subependymal giant cell astrocytoma) and renal manifestations (angiomyolipoma) associated with TSC. This review provides an overview of TSC, everolimus, and the clinical trials that led to its approval for the treatment of TSC-associated subependymal giant cell astrocytoma and renal angiomyolipoma. We are reporting on a 13.5-year-old girl with tuberous sclerosis complex (TSC) who was treated with everolimus because of giant cell astrocytoma and bilateral angiomyolipoma. She suffered from pharmacoresistant partial epilepsy with clusters of tonic and tonic-clonic seizures. Treatment with carbamazepine and sulthiame had led to a stable situation for more than 2.5 years. The dosage of everolimus had to be increased and refractory status epilepticus followed after 12 days. In the absence of any other possible cause, we believe that the status epilepticus was provoked by everolimus. So far, only a few cases of possible seizure aggravation by everolimus have been reported. The clinical relevance of possible negative effects in epileptic patients remains unclear. Similar observations should be documented and reported. BACKGROUND: Tuberous sclerosis complex is a genetic disorder leading to constitutive activation of mammalian target of rapamycin (mTOR) and growth of benign tumours in several organs. In the brain, growth of subependymal giant cell astrocytomas can cause life-threatening symptoms--eg, hydrocephalus, requiring surgery. In an open-label, phase 1/2 study, the mTOR inhibitor everolimus substantially and significantly reduced the volume of subependymal giant cell astrocytomas. We assessed the efficacy and safety of everolimus in patients with subependymal giant cell astrocytomas associated with tuberous sclerosis complex. METHODS: In this double-blind, placebo-controlled, phase 3 trial, patients (aged 0-65 years) in 24 centres in Australia, Belgium, Canada, Germany, the UK, Italy, the Netherlands, Poland, Russian Federation, and the USA were randomly assigned, with an interactive internet-response system, in a 2:1 ratio to oral everolimus 4·5 mg/m(2) per day (titrated to achieve blood trough concentrations of 5-15 ng/mL) or placebo. Eligible patients had a definite diagnosis of tuberous sclerosis complex and at least one lesion with a diameter of 1 cm or greater, and either serial growth of a subependymal giant cell astrocytoma, a new lesion of 1 cm or greater, or new or worsening hydrocephalus. The primary endpoint was the proportion of patients with confirmed response--ie, reduction in target volume of 50% or greater relative to baseline in subependymal giant cell astrocytomas. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00789828. FINDINGS: 117 patients were randomly assigned to everolimus (n=78) or placebo (n=39). 27 (35%) patients in the everolimus group had at least 50% reduction in the volume of subependymal giant cell astrocytomas versus none in the placebo group (difference 35%, 95% CI 15-52; one-sided exact Cochran-Mantel-Haenszel test, p<0·0001). Adverse events were mostly grade 1 or 2; no patients discontinued treatment because of adverse events. The most common adverse events were mouth ulceration (25 [32%] in the everolimus group vs two [5%] in the placebo group), stomatitis (24 [31%] vs eight [21%]), convulsion (18 [23%] vs ten [26%]), and pyrexia (17 [22%] vs six [15%]). INTERPRETATION: These results support the use of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis. Additionally, everolimus might represent a disease-modifying treatment for other aspects of tuberous sclerosis. FUNDING: Novartis Pharmaceuticals.

Are integrins part of the extracellular matrix?

Yes, integrins are a central family of extracellular matrix receptors.

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The extracellular matrix component periostin is a secreted protein that functions as both a cell attachment protein and an autocrine or paracrine factor that signals through the cell adhesion molecule integrins αvβ3 and αvβ5. Periostin participates in normal physiological activities such as cardiac development, but is also involved in pathophysiological processes in vascular diseases, wound repair, bone formation, and tumor development. It is of increasing interest in tumor biology because it is frequently overexpressed in a variety of epithelial carcinomas and is functionally involved in multiple steps of metastasis progression. These include the maintenance of stemness, niche formation, EMT, the survival of tumor cells, and angiogenesis, all of which are indispensable for gastric cancer metastasis. Periostin has been reported to activate the PI-3K/AKT, Wnt, and FAK-mediated signaling pathways to promote metastasis. Therefore, periostin represents a potentially promising candidate for the inhibition of metastasis. In this review article, we summarize recent advances in knowledge concerning periostin, its antagonist PNDA-3, and their influence on such key processes in cancer metastasis as maintenance of stemness, niche formation, epithelial-to-mesenchymal transition, tumor cell survival, and angiogenesis. In particular, we focus our attention on the role of periostin in gastric cancer metastasis, speculate as to the usefulness of periostin as a therapeutic and diagnostic target for gastric cancer metastasis, and consider potential avenues for future research. We have previously reported a unique response of traction force generation for cells grown on mature cardiac ECM, where traction force was constant over a range of stiffnesses. In this study we sought to further investigate the role of the complex mixture of ECM on this response and assess the potential mechanism behind it. Using traction force microscopy, we measured cellular traction forces and stresses for mesenchymal stem cells (MSCs) grown on polyacrylamide gels at a range of stiffnesses (9, 25, or 48 kPa) containing either adult rat heart ECM, different singular ECM proteins including collagen I, fibronectin, and laminin, or ECM mimics comprised of varying amounts of collagen I, fibronectin, and laminin. We also measured the expression of integrins on these different substrates as well as probed for β1 integrin binding. There was no significant change in traction force generation for cells grown on the adult ECM, as previously reported, whereas cells grown on singular ECM protein substrates had increased traction force generation with an increase in substrate stiffness. Cells grown on ECM mimics containing collagen I, fibronectin and laminin were found to be reminiscent of the traction forces generated by cells grown on native ECM. Integrin expression generally increased with increasing stiffness except for the β1 integrin, potentially implicating it as playing a role in the response to adult cardiac ECM. We inhibited binding through the β1 integrin on cells grown on the adult ECM and found that the inhibition of β1 binding led to a return to the typical response of increasing traction force generation with increasing stiffness. Our data demonstrates that cells grown on the mature cardiac ECM are able to circumvent typical stiffness related cellular behaviors, likely through β1 integrin binding to the complex composition. BACKGROUND: The growth properties and self-renewal capacity of embryonic stem (ES) cells are regulated by their immediate microenvironment such as the extracellular matrix (ECM). Integrins, a central family of cellular ECM receptors, have been implicated in these processes but their specific role in ES cell self-renewal remains unclear. RESULTS: Here we have studied the effects of different ECM substrates and integrins in mouse ES cells in the absence of Leukemia Inhibitory Factor (LIF) using short-term assays as well as long-term cultures. Removal of LIF from ES cell culture medium induced morphological differentiation of ES cells into polarized epistem cell-like cells. These cells maintained epithelial morphology and expression of key stemness markers for at least 10 passages in the absence of LIF when cultured on laminin, fibronectin or collagen IV substrates. The specific functional roles of α6-, αV- and β1-integrin subunits were dissected using stable lentivirus-mediated RNAi methodology. β1-integrins were required for ES cell survival in long-term cultures and for the maintenance of stem cell marker expression. Inhibition of α6-integrin expression compromised self-renewal on collagen while αV-integrins were required for robust ES cell adhesion on laminin. Analysis of the stemness marker expression revealed subtle differences between α6- and αV-depleted ES cells but the expression of both was required for optimal self-renewal in long-term ES cell cultures. CONCLUSIONS: In the absence of LIF, long-term ES cell cultures adapt an epistem cell-like epithelial phenotype and retain the expression of multiple stem cell markers. Long-term maintenance of such self-renewing cultures depends on the expression of β1-, α6- and αV-integrins. Mechanosensitive ion channels (MSCs) have long been the only established molecular class of cell mechanosensors; however, in the last decade, a variety of non-channel type mechanosensor molecules have been identified. Many of them are focal adhesion-associated proteins that include integrin, talin, and actin. Mechanosensors must be non-soluble molecules firmly interacting with relatively rigid cellular structures such as membranes (in terms of lateral stiffness), cytoskeletons, and adhesion structures. The partner of MSCs is the membrane in which MSC proteins efficiently transduce changes in the membrane tension into conformational changes that lead to channel opening. By contrast, the integrin, talin, and actin filament form a linear complex of which both ends are typically anchored to the extracellular matrices via integrins. Upon cell deformation by forces, this structure turns out to be a portion that efficiently transduces the generated stress into conformational changes of composite molecules, leading to the activation of integrin (catch bond with extracellular matrices) and talin (unfolding to induce vinculin bindings). Importantly, this structure also serves as an "active" mechanosensor to detect substrate rigidity by pulling the substrate with contraction of actin stress fibers (SFs), which may induce talin unfolding and an activation of MSCs in the vicinity of integrins. A recent study demonstrates that the actin filament acts as a mechanosensor with unique characteristics; the filament behaves as a negative tension sensor in which increased torsional fluctuations by tension decrease accelerate ADF/cofilin binding, leading to filament disruption. Here, we review the latest progress in the study of those non-channel mechanosensors and discuss their activation mechanisms and physiological roles. Integrin receptors connect the extracellular matrix to the cell cytoskeleton to provide essential forces and signals. To examine the contributions of the β1 integrin cytoplasmic tail to adhesive forces, we generated cell lines expressing wild-type and tail mutant β1 integrins in β1-null fibroblasts. Deletion of β1 significantly reduced cell spreading, focal adhesion assembly, and adhesive forces, and expression of human β1 (hβ1) integrin in these cells restored adhesive functions. Cells expressing a truncated tail mutant had impaired spreading, fewer and smaller focal adhesions, reduced integrin binding to fibronectin, and lower adhesion strength and traction forces compared to hβ1-expressing cells. All these metrics were equivalent to those for β1-null cells, demonstrating that the β1 tail is essential to these adhesive functions. Expression of the constitutively-active D759A hβ1 mutant restored many of these adhesive functions in β1-null cells, although with important differences when compared to wild-type β1. Even though there were no differences in integrin-fibronectin binding and adhesion strength between hβ1- and hβ1-D759A-expressing cells, hβ1-D759A-expressing cells assembled more but smaller adhesions than hβ1-expressing cells. Importantly, hβ1-D759A-expressing cells generated lower traction forces compared to hβ1-expressing cells. These differences between hβ1- and hβ1-D759A-expressing cells suggest that regulation of integrin activation is important for fine-tuning cell spreading, focal adhesion assembly, and traction force generation. The aim of the present review is to survey the accumulated knowledge on the extracellular matrix (ECM) of tumors referring to its putative utility as therapeutic target. Following the traditional observation on the extensive morphological alteration in the tumor-affected tissue, the well-documented aberrant cellular regulation indicated that ECM components have an active role in tumor progression. However, due to the diverse functions and variable expression of proteoglycans, matrix proteins, and integrins, it is rather difficult to identify a comprehensive therapeutic target among ECM components. At present, the elevated level of heparanase and the prominent expression of αvβ5 integrin are considered as promising therapeutic targets. The inhibition of glycosaminoglycan offers another promising approach in the treatment of those tumors which are stimulated by proteoglycans. It can be ascertained that a selective ECM inhibitor would be a great asset to control metastasis driven by ECM-mediated signaling. Integrin-dependent cell-extracellular matrix (ECM) adhesion is a determinant of spindle orientation. However, the signaling pathways that couple integrins to spindle orientation remain elusive. Here, we show that PCTAIRE-1 kinase (PCTK1), a member of the cyclin-dependent kinases (CDKs) whose function is poorly characterized, plays an essential role in this process. PCTK1 regulates spindle orientation in a kinase-dependent manner. Phosphoproteomic analysis together with an RNA interference screen revealed that PCTK1 regulates spindle orientation through phosphorylation of Ser83 on KAP0, a regulatory subunit of protein kinase A (PKA). This phosphorylation is dispensable for KAP0 dimerization and for PKA binding but is necessary for its interaction with myosin X, a regulator of spindle orientation. KAP0 binds to the FERM domain of myosin X and enhances the association of myosin X-FERM with β1 integrin. This interaction between myosin X-FERM and β1 integrin appeared to be crucial for spindle orientation control. We propose that PCTK1-KAP0-myosin X-β1 integrin is a functional module providing a link between ECM and the actin cytoskeleton in the ECM-dependent control of spindle orientation. During development, growth factors (GFs) such as bone morphogenetic proteins (BMPs) exert important functions in several tissues by regulating signaling for cell differentiation and migration. In vivo, the extracellular matrix (ECM) not only provides support for adherent cells, but also acts as reservoir of GFs. Several constituents of the ECM provide adhesive cues, which serve as binding sites for cell trans-membrane receptors, such as integrins. In conveying adhesion-mediated signaling to the intracellular compartment, integrins do not function alone but rather crosstalk and cooperate with other receptors, such as GF receptors. Here, we present a strategy for the immobilization of BMP-2 onto cellular fibronectin (cFN), a key protein of the ECM, to investigate GF-mediated signaling and migration. Following biotinylation, BMP-2 was linked to biotinylated cFN using NeutrAvidin as cross-linker. Characterization with quartz crystal microbalance with dissipation monitoring and enzyme-linked immunosorbent assay confirmed the efficient immobilization of BMP-2 on cFN over a period of 24 h. To validate the bioactivity of matrix-immobilized BMP-2 (iBMP-2), we investigated short- and long-term responses of C2C12 myoblasts, which are an established in vitro model for BMP-2 signaling, in comparison to soluble BMP-2 (sBMP-2) or in absence of GFs. Similarly to sBMP-2, iBMP-2 triggered Smad 1/5 phosphorylation and translocation of the complex to the nucleus, corresponding to the activation of BMP-mediated Smad-dependent pathway. Additionally, successful suppression of myotube formation was observed after 6 days in sBMP-2 and iBMP-2. We next implemented this approach in the fabrication of cFN micropatterned stripes by soft lithography. These stripes allowed cell-surface interaction only on the patterned cFN, since the surface in between was passivated, thus serving as platform for studies on directed cell migration. During a 10-h observation time, the migratory behavior, especially the cells' net displacement, was increased in presence of BMP-2. As such, this versatile tool retains the bioactivity of GFs and allows the presentation of ECM adhesive cues. Breast cancer is the second leading cause of malignant death among women. A crucial feature of metastatic cancers is their propensity to lose adhesion to the underlying basement membrane as they transition to a motile phenotype and invade surrounding tissue. Attachment to the extracellular matrix is mediated by a complex of adhesion proteins, including integrins, signaling molecules, actin and actin-binding proteins, and scaffolding proteins. Focal adhesion kinase (FAK) is pivotal for the organization of focal contacts and maturation into focal adhesions, and disruption of this process is a hallmark of early cancer invasive potential. Our recent work has revealed that myoferlin (MYOF) mediates breast tumor cell motility and invasive phenotype. In this study we demonstrate that noninvasive breast cancer cell lines exhibit increased cell-substrate adhesion and that silencing of MYOF using RNAi in the highly invasive human breast cancer cell line MDA-MB-231 also enhances cell-substrate adhesion. In addition, we detected elevated tyrosine phosphorylation of FAK (FAK(Y397)) and paxillin (PAX(Y118)), markers of focal adhesion protein activation. Morphometric analysis of PAX expression revealed that RNAi-mediated depletion of MYOF resulted in larger, more elongated focal adhesions, in contrast to cells transduced with a control virus (MDA-231(LVC) cells), which exhibited smaller focal contacts. Finally, MYOF silencing in MDA-MB-231 cells exhibited a more elaborate ventral cytoskeletal structure near focal adhesions, typified by pronounced actin stress fibers. These data support the hypothesis that MYOF regulates cell adhesions and cell-substrate adhesion strength and may account for the high degree of motility in invasive breast cancer cells. The diverse morphologies of animal tissues are underlain by different configurations of adherent cells and extracellular matrix (ECM). Here, we elucidate a cross-scale mechanism for tissue assembly and ECM remodeling involving Cadherin 2, the ECM protein Fibronectin, and its receptor Integrin α5. Fluorescence cross-correlation spectroscopy within the zebrafish paraxial mesoderm mesenchyme reveals a physical association between Integrin α5 on adjacent cell membranes. This Integrin-Integrin complex correlates with conformationally inactive Integrin. Cadherin 2 stabilizes both the Integrin association and inactive Integrin conformation. Thus, Integrin repression within the adherent mesenchymal interior of the tissue biases Fibronectin fibrillogenesis to the tissue surface lacking cell-cell adhesions. Along nascent somite boundaries, Cadherin 2 levels decrease, becoming anti-correlated with levels of Integrin α5. Simultaneously, Integrin α5 clusters and adopts the active conformation and then commences ECM assembly. This cross-scale regulation of Integrin activation organizes a stereotypic pattern of ECM necessary for vertebrate body elongation and segmentation.

Is Calcium homeostasis important in cardiac physiology and pathophysiology?

Calcium homeostasis is very important in cardiac physiology and pathophysiology. Maintenance of cellular calcium homeostasis is critical to regulating cardiac contraction. Abnormalities in calcium homeostasis underlie cardiac arrhythmia, contractile dysfunction and cardiac remodelling.

[21750914, 24657282, 22707075, 20347784, 22673935, 22137362, 23595672, 20457122, 7889444, 17517353, 19920172, 17509680, 21614516, 22733365, 18172603, 17353151, 23554644, 19068246, 20875630, 19678847]

Maintenance of cellular calcium homeostasis is critical to regulating mitochondrial ATP production and cardiac contraction. The ion channel known as the L-type calcium channel is the main route for calcium entry into cardiac myocytes. The channel associates with cytoskeletal proteins that assist with the communication of signals from the plasma membrane to intracellular organelles, including mitochondria. This article explores the roles of calcium and the cytoskeleton in regulation of mitochondrial function in response to alterations in L-type calcium channel activity. Direct activation of the L-type calcium channel results in an increase in intracellular calcium and increased mitochondrial calcium uptake. As a result, mitochondrial NADH production, oxygen consumption and reactive oxygen species production increase. In addition the L-type calcium channel is able to regulate mitochondrial membrane potential via cytoskeletal proteins when conformational changes in the channel occur during activation and inactivation. Since the L-type calcium channel is the initiator of contraction, a functional coupling between the channel and mitochondria via the cytoskeleton may represent a synchronised process by which mitochondrial function is regulated in addition to calcium influx to meet myocardial energy demand on a beat to beat basis. Cardiac calcium (Ca(2+)) handling subsumes the mechanisms maintaining the myocardial Ca(2+) homeostasis that contribute essentially to cardiac performance. This review addresses the interaction of transplasmalemmal and transsarcoplasmic Ca(2+) flux, its potential modifications due to β-adrenergic stimulation and its implications on cardiac action potential. Important insights into the molecular basis of hypertrophic cardiomyopathy and related diseases have been gained by studying families with inherited cardiac hypertrophy. Integrated clinical and genetic investigations have demonstrated that different genetic defects can give rise to the common phenotype of cardiac hypertrophy. Diverse pathways have been identified, implicating perturbations in force generation, force transmission, intracellular calcium homeostasis, myocardial energetics, and cardiac metabolism in causing disease. Although not fully elucidated, the fundamental mechanisms linking gene mutations to clinical disease are being characterized. Further advances will allow a better understanding of pathogenesis, diagnosis, and treatment, not just of relatively rare inherited cardiomyopathies, but potentially also of relevance to more common acquired forms of hypertrophic remodeling. Ca(2+) is a universal carrier of biological information: it controls cell life from its origin at fertilization to its end in the process of programmed cell death. Ca(2+) is a conventional diffusible second messenger released inside cells by the interaction of first messengers with plasma membrane receptors. However, it can also penetrate directly into cells to deliver information without the intermediation of first or second messengers. Even more distinctively, Ca(2+) can act as a first messenger, by interacting with a plasma membrane receptor to set in motion intracellular signaling pathways that involve Ca(2+) itself. Perhaps the most distinctive property of the Ca(2+) signal is its ambivalence: while essential to the correct functioning of cells, Ca(2+) becomes an agent that mediates cell distress, or even (toxic) cell death, if its concentration and movements inside cells are not carefully tuned. Ca(2+) is controlled by reversible complexation to specific proteins, which could be pure Ca(2+) buffers, or which, in addition to buffering Ca(2+), also decode its signal to pass it on to targets. The most important actors in the buffering of cell Ca(2+) are proteins that transport it across the plasma membrane and the membrane of the organelles: some have high Ca(2+) affinity and low transport capacity (e.g., Ca(2+) pumps), others have opposite properties (e.g., the Ca(2+) uptake system of mitochondria). Between the initial event of fertilization, and the terminal event of programmed cell death, the Ca(2+) signal regulates the most important activities of the cell, from the expression of genes, to heart and muscle contraction and other motility processes, to diverse metabolic pathways involved in the generation of cell fuels. Energy metabolism and Ca(2+) handling serve critical roles in cardiac physiology and pathophysiology. Peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1 alpha) is a multi-functional coactivator that is involved in the regulation of cardiac mitochondrial functional capacity and cellular energy metabolism. However, the regulation of PGC-1 alpha in cardiac Ca(2+) signaling has not been fully elucidated. To address this issue, we combined confocal line-scan imaging with off-line imaging processing to characterize calcium signaling in cultured adult rat ventricular myocytes expressing PGC-1 alpha via adenoviral transduction. Our data shows that overexpressing PGC-1 alpha improved myocyte contractility without increasing the amplitude of Ca(2+) transients, suggesting that myofilament sensitivity to Ca(2+) increased. Interestingly, the decay kinetics of global Ca(2+) transients and Ca(2+) waves accelerated in PGC-1 alpha-expressing cells, but the decay rate of caffeine-elicited Ca(2+) transients showed no significant change. This suggests that sarcoplasmic reticulum (SR) Ca(2+)-ATPase (SERCA2a), but not Na(+)/Ca(2+) exchange (NCX) contribute to PGC-1 alpha-induced cytosolic Ca(2+) clearance. Furthermore, PGC-1 alpha induced the expression of SERCA2a in cultured cardiac myocytes. Importantly, overexpressing PGC-1 alpha did not disturb cardiac Ca(2+) homeostasis, because SR Ca(2+) load and the propensity for Ca(2+) waves remained unchanged. These data suggest that PGC-1 alpha can ameliorate cardiac Ca(2+) cycling and improve cardiac work output in response to physiological stress. Unraveling the PGC-1 alpha-calcium handling pathway sheds new light on the role of PGC-1 alpha in the therapy of cardiac diseases. OBJECTIVE: To compare clinically relevant pharmacokinetic, pharmacodynamic and toxico logical characteristics of calcium-modulating compounds used in ischemic heart disease. DATA SOURCES: A MEDLINE search (1990 pt B to 1991 pt A revised for 1993; 1991 pt B to 1992 revised for 1993; and January to May 1993) combining the search phrases 'calcium channel blockers', 'myocardial ischemia', 'pharmacodynamics' and 'pharmacokinetics', and a search in Compact Cambridge Drug Information Source vol-6 (revised 1992, fourth quarter) using the search phrase 'calcium antagonists' and medical subject headings (MeSH) 'pharmacokinetics' and 'pharmacodynamics' were used to obtain title and abstract information on available current literature. STUDY SELECTION: Review articles, proceedings and studies published in English and available within the University of Saskatchewan library system, as they appeared to relate closely to the objective, were obtained for closer evaluation. In addition, primary references were examined, and journal reprints were selected from the authors' files. DATA EXTRACTION: The focus was on studies and objective reviews that profiled one or more representative compounds in a manner suitable for deriving background and comparative information pertaining to the objective. Data from multiple studies, or from studies that employed multiple methodological approaches, were preferentially extracted and summarized for presentation. DATA SYNTHESIS: The role of calcium in cardiac and vascular smooth muscle physiology was reviewed, highlighting the major mechanisms responsible for maintaining calcium homeostasis in these cells. With a focus on verapamil, diltiazem and 1,4-dihydropyridines currently employed in the treatment of cardiovascular disorders, a general survey of their sites of action, tissue selective pharmacodynamics, pharmacokinetic properties and side effects was undertaken in a comparative context. CONCLUSIONS: Calcium antagonists are employed in the treatment of angina, certain cardiac arrhythmias and hypertension. They are a chemically and pharmacologically heterogeneous group of compounds that act principally to inhibit the influx of calcium across certain voltage-dependent membrane channels. Concepts pertaining to calcium mobilization in the pathophysiology of myocardial ischemia, particularly at the molecular level, have evolved remarkably over the past decade. The repertoire of agents having calcium-regulating properties has expanded in parallel. The task of integrating new knowledge in both of these areas requires further attention in order to determine optimal approaches to treatment. BACKGROUND: The cardiac sodium-calcium exchanger (NCX1) is a key sarcolemmal protein for the maintenance of calcium homeostasis in the heart. Because heart failure is associated with increased expression of NCX1, heterozygous (HET) and homozygous (HOM) transgenic mice overexpressing NCX1 were developed and evaluated. METHODS AND RESULTS: The NCX1 transgenic mice display 2.3-fold (HET) and 3.1-fold (HOM) increases in exchanger activity from wild-type (WT) mice. Functional information was obtained by echocardiography and catheterizations before and after hemodynamic stress from pregnancy, treadmill exercise or transaortic constriction (TAC). HET and HOM mice exhibited hypertrophy and blunted responses with beta-adrenergic stimulation. Postpartum mice from all groups were hypertrophied, but only the HOM mice exhibited premature death from heart failure. HOM mice became exercise intolerant after 6 weeks of daily treadmill running. After 21 days TAC, HET, and HOM mice exhibited significant contractile dysfunction and 15% to 40% mortality with clinical evidence of heart failure. CONCLUSIONS: Hemodynamic stress results in a compensated hypertrophy in WT mice, but NCX1 transgenic mice exhibit decreased contractile function and heart failure in proportion to their level of NCX1 expression. Thus exchanger overexpression in mice leads to abnormal calcium handling and a decompensatory transition to heart failure with stress. Central to controlling intracellular calcium concentration ([Ca(2+)](i)) are a number of Ca(2+) transporters and channels with the L-type Ca(2+) channel, Na(+)-Ca(2+) exchanger and sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) being of particular note in the heart. This review concentrates on the regulation of [Ca(2+)](i) in cardiac muscle and the homeostatic mechanisms employed to ensure that the heart can operate under steady-state conditions on a beat by beat basis. To this end we discuss the relative importance of various sources and sinks of Ca(2+) responsible for initiating contraction and relaxation in cardiac myocytes and how these can be manipulated to regulate the Ca(2+) content of the major Ca(2+) store, the sarcoplasmic reticulum (SR). We will present a simple feedback system detailing how such control can be achieved and highlight how small perturbations to the steady-state operation of the feedback loop can be both beneficial physiologically and underlie changes in systolic Ca(2+) in ageing and heart disease. In addition to manipulating the amplitude of the normal systolic Ca(2+) transient, the tight regulation of SR Ca(2+) content is also required to prevent the abnormal, spontaneous or diastolic release of Ca(2+) from the SR. Such diastolic events are a major factor contributing to the genesis of cardiac arrhythmias in disease situations and in recently identified familial mutations in the SR Ca(2+) release channel (ryanodine receptor, RyR). How such diastolic release arises and potential mechanisms for controlling this will be discussed. Calcium is an important mediator in cardiac excitation and disorders in cardiac Ca(2+) homeostasis have great influence on the cardiac action potential. Therefore dysfunction in regulatory proteins that are involved in Ca(2+) handling can lead to the occurrence of severe arrhythmia. Although mutations in Ca(2+) regulating proteins are quite rare, they can offer general insights into arrhythmogenesis. Here, we briefly review some important aspects of arrhythmia-associated mutations in Ca(2+) regulating proteins with special emphasis to its associated pathophysiology. With aging, the heart develops myocyte hypertrophy associated with impaired relaxation indices. To define the cellular basis of this adaptation, we examined the physiological changes that arise in calcium handling in the aging heart and contrasted the adaptations that occur following the imposition of a stimulus that alters calcium homeostasis in a young and an old heart. We utilized a cardiac-specific conditional transgenic approach to "switch on" protein kinase (PKC)-beta II expression in mice at different stages of adult life (3 and 12 months) and characterized alterations in ICa and calcium release in wild-type (WT) and PKC-beta II-expressing cells. Amplitude or voltage dependence of ICa were not significantly altered by expression of PKC-beta II at any age. No significant differences in calcium-release properties were seen with age. Upon activation of PKC-beta II, the amplitude of the calcium transient was larger, and the calcium spark frequency was greater in PKC-beta II mice compared to WT at both 3 and 12 months. Spark amplitude increased only in the 12-month PKC-beta II mice. These changes occurred in parallel with an increase in cell size (as determined by capacitance measurements) in the 12-month PKC-beta II mice but not the 3-month PKC-beta II mice. These data suggest that alterations in the calcium-handling machinery of the cardiocyte differ in the context of age and as such may predispose the older heart to the development of a hypertrophic phenotype. Ion channels underlie the electrical activity of cells. Calcium channels have a unique functional role, because not only do they participate in this activity, they form the means by which electrical signals are converted to responses within the cell. Calcium channels play an integral role in excitation in the heart and shaping the cardiac action potential. In addition, calcium influx through calcium channels is responsible for initiating contraction. Abnormalities in calcium homeostasis underlie cardiac arrhythmia, contractile dysfunction and cardiac remodelling. Reactive oxygen species participate in the development of pathology by altering the redox state of regulatory proteins. There is now good evidence that reactive oxygen species regulate the function of calcium channels. In this mini-review, the evidence for regulation of calcium channels by reactive oxygen species and implications with respect to pathology are presented. Calcium channels may represent a target for intervention during hypoxic trigger of arrhythmia or chronic pathological remodelling. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a primary electrical myocardial disease characterized by exercise- and stress-related ventricular tachycardia manifested as syncope and sudden death. The disease has a heterogeneous genetic basis, with mutations in the cardiac Ryanodine Receptor channel (RyR2) gene accounting for an autosomal-dominant form (CPVT1) in approximately 50% and mutations in the cardiac calsequestrin gene (CASQ2) accounting for an autosomal-recessive form (CPVT2) in up to 2% of CPVT cases. Both RyR2 and calsequestrin are important participants in the cardiac cellular calcium homeostasis. We review the physiology of the cardiac calcium homeostasis, including the cardiac excitation contraction coupling and myocyte calcium cycling. The pathophysiology of cardiac arrhythmias related to myocyte calcium handling and the effects of different modulators are discussed. The putative derangements in myocyte calcium homeostasis responsible for CPVT, as well as the clinical manifestations and therapeutic options available, are described. Our understanding of the molecular processes which regulate cardiac function has grown immeasurably in recent years. Even with the advent of β-blockers, angiotensin inhibitors and calcium modulating agents, heart failure (HF) still remains a seriously debilitating and life-threatening condition. Here, we review the molecular changes which occur in the heart in response to increased load and the pathways which control cardiac hypertrophy, calcium homeostasis, and immune activation during HF. These can occur as a result of genetic mutation in the case of hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) or as a result of ischemic or hypertensive heart disease. In the majority of cases, calcineurin and CaMK respond to dysregulated calcium signaling and adrenergic drive is increased, each of which has a role to play in controlling blood pressure, heart rate, and left ventricular function. Many major pathways for pathological remodeling converge on a set of transcriptional regulators such as myocyte enhancer factor 2 (MEF2), nuclear factors of activated T cells (NFAT), and GATA4 and these are opposed by the action of the natriuretic peptides ANP and BNP. Epigenetic modification has emerged in recent years as a major influence cardiac physiology and histone acetyl transferases (HATs) and histone deacetylases (HDACs) are now known to both induce and antagonize hypertrophic growth. The newly emerging roles of microRNAs in regulating left ventricular dysfunction and fibrosis also has great potential for novel therapeutic intervention. Finally, we discuss the role of the immune system in mediating left ventricular dysfunction and fibrosis and ways this can be targeted in the setting of viral myocarditis. Calcium ions are the most ubiquitous and versatile signaling molecules in eukaryotic cells. Calcium homeostasis and signaling systems are crucial for both the normal growth of the budding yeast Saccharomyces cerevisiae and the intricate working of the mammalian heart. In this paper, we make a detailed comparison between the calcium homeostasis/signaling networks in yeast cells and those in mammalian cardiac myocytes. This comparison covers not only the components, structure and function of the networks but also includes existing knowledge on the measured and simulated network dynamics using mathematical models. Surprisingly, most of the factors known in the yeast calcium homeostasis/signaling network are conserved and operate similarly in mammalian cells, including cardiac myocytes. Moreover, the budding yeast S. cerevisiae is a simple organism that affords powerful genetic and genomic tools. Thus, exploring and understanding the calcium homeostasis/signaling system in yeast can provide a shortcut to help understand calcium homeostasis/signaling systems in mammalian cardiac myocytes. In turn, this knowledge can be used to help treat relevant human diseases such as pathological cardiac hypertrophy and heart failure.

List available databases containing information about conserved noncoding elements.

Ancora and TFCONES.

[18045502, 18279518]

BACKGROUND: Transcription factors (TFs) regulate gene transcription and play pivotal roles in various biological processes such as development, cell cycle progression, cell differentiation and tumor suppression. Identifying cis-regulatory elements associated with TF-encoding genes is a crucial step in understanding gene regulatory networks. To this end, we have used a comparative genomics approach to identify putative cis-regulatory elements associated with TF-encoding genes in vertebrates. DESCRIPTION: We have created a database named TFCONES (Transcription Factor Genes & Associated COnserved Noncoding ElementS) (http://tfcones.fugu-sg.org) which contains all human, mouse and fugu TF-encoding genes and conserved noncoding elements (CNEs) associated with them. The CNEs were identified by gene-by-gene alignments of orthologous TF-encoding gene loci using MLAGAN. We also predicted putative transcription factor binding sites within the CNEs. A significant proportion of human-fugu CNEs contain experimentally defined binding sites for transcriptional activators and repressors, indicating that a majority of the CNEs may function as transcriptional regulatory elements. The TF-encoding genes that are involved in nervous system development are generally enriched for human-fugu CNEs. Users can retrieve TF-encoding genes and their associated CNEs by conducting a keyword search or by selecting a family of DNA-binding proteins. CONCLUSION: The conserved noncoding elements identified in TFCONES represent a catalog of highly prioritized putative cis-regulatory elements of TF-encoding genes and are candidates for functional assay. Metazoan genomes contain arrays of highly conserved noncoding elements (HCNEs) that span developmental regulatory genes and define regulatory domains. We describe Ancora http://ancora.genereg.net, a web resource that provides data and tools for exploring genomic organization of HCNEs for multiple genomes. Ancora includes a genome browser that shows HCNE locations and features novel HCNE density plots as a powerful tool to discover developmental regulatory genes and distinguish their regulatory elements and domains.

What was the purpose of the FANTOM5 project?

The functional annotation of the mammalian genome 5 (FANTOM5) project provides comprehensive expression profiles and functional annotation of mammalian cell-type-specific transcriptomes with wide applications in biomedical research. The FANTOM5 and ENCODE projects represent two independent large scale efforts to map regulatory and transcriptional features to the human genome.

[24669905, 24670763, 24670764]

BACKGROUND: Deciphering the most common modes by which chromatin regulates transcription, and how this is related to cellular status and processes is an important task for improving our understanding of human cellular biology. The FANTOM5 and ENCODE projects represent two independent large scale efforts to map regulatory and transcriptional features to the human genome. Here we investigate chromatin features around a comprehensive set of transcription start sites in four cell lines by integrating data from these two projects. RESULTS: Transcription start sites can be distinguished by chromatin states defined by specific combinations of both chromatin mark enrichment and the profile shapes of these chromatin marks. The observed patterns can be associated with cellular functions and processes, and they also show association with expression level, location relative to nearby genes, and CpG content. In particular we find a substantial number of repressed inter- and intra-genic transcription start sites enriched for active chromatin marks and Pol II, and these sites are strongly associated with immediate-early response processes and cell signaling. Associations between start sites with similar chromatin patterns are validated by significant correlations in their global expression profiles. CONCLUSIONS: The results confirm the link between chromatin state and cellular function for expressed transcripts, and also indicate that active chromatin states at repressed transcripts may poise transcripts for rapid activation during immune response. Collaborators: Forrest AR, Kawaji H, Rehli M, Baillie JK, de Hoon MJ, Haberle V, Lassmann T, Kulakovskiy IV, Lizio M, Itoh M, Andersson R, Mungall CJ, Meehan TF, Schmeier S, Bertin N, Jørgensen M, Dimont E, Arner E, Schmid C, Schaefer U, Medvedeva YA, Plessy C, Vitezic M, Severin J, Semple CA, Ishizu Y, Young RS, Francescatto M, Alam I, Albanese D, Altschuler GM, Arakawa T, Archer JA, Arner P, Babina M, Rennie S, Balwierz PJ, Beckhouse AG, Pradhan-Bhatt S, Blake JA, Blumenthal A, Bodega B, Bonetti A, Briggs J, Brombacher F, Burroughs AM, Califano A, Cannistracti CV, Carbajo D, Chen Y, Chierici M, Ciani Y, Clevers HC, Dalla E, Davis CA, Detmar M, Diehl AD, Dohi T, Drabløs F, Edge AS, Edinger M, Ekwall K, Endoh M, Enomoto H, Fagiolini M, Fairbairn L, Fang H, Farach-Carson MC, Faulkner GJ, Favorov AV, Fisher ME, Frith MC, Fujita R, Fukuda S, Furlanello C, Furuno M, Furusawa J, Geijtenbeek TB, Gibson AP, Gingeras T, Goldowitz D, Gough J, Guhl S, Guler R, Gustincich S, Ha TJ, Hamaguchi M, Hara M, Harbers M, Harshbarger J, Hasegawa A, Hasegawa Y, Hashimoto T, Herlyn M, Hitchens KJ, Ho Sui SJ, Hofman OM, Hoof I, Hori F, Huminiecki L, Iida K, Ikawa T, Jankovic BR, Jia H, Joshi A, Jurman G, Kaczkowski B, Kai C, Kaida K, Kaiho A, Kajiyama K, Kanamori-Katayama M, Kasianov AS, Kasukawa T, Katayama S, Kato S, Kawaguchi S, Kawamoto H, Kawamura YI, Kawashima T, Kempfle JS, Kenna TJ, Kere J, Khachigian LM, Kitamura T, Klinken SP, Knox AJ, Kojima M, Kojima S, Kondo N, Koseki H, Koyasu S, Krampitz S, Kubosaki A, Kwon AT, Laros JF, Lee W, Lennartsson A, Li K, Lilje B, Lipovich L, Mackay-Sim A, Manabe R, Mar JC, Marchand B, Mathelier A, Mejhert N, Meynert A, Mizuno Y, de Lima Morais DA, Morikawa H, Morimoto M, Moro K, Motakis E, Motohashi H, Mummery CL, Murata M, Nagao-Sato S, Nakachi Y, Nakahara F, Nakamura T, Nakamura Y, Nakazato K, van Nimwegen E, Ninomiya N, Nishiyori H, Noma S, Nozaki T, Ogishima S, Ohkura N, Ohmiya H, Ohno H, Onshima M, Okada-Hatakeyama M, Okazaki Y, Orlando V, Ovchinnikov DA, Pain A, Passier R, Patrikakis M, Persson H, Piazza S, Prendergast JG, Rackham OJ, Ramilowski JA, Rashid M, Ravasi T, Rizzu P, Roncador M, Roy S, Rye MB, Saijyo E, Sajantila A, Saka A, Sakaguchi S, Sakai M, Sato H, Satoh H, Savvi S, Saxena A, Schneider C, Schultes EA, Schultz-Tanzil GG, Schwegmann A, Sengstag T, Sheng G, Shimoji H, Shimoni Y, Shin JW, Simon C, Sugiyama D, Sugiyama T, Suzuki M, Suzuki N, Swoboda RK, 't Hoen PA, Tagami M, Takahashi N, Takai J, Tanaka H, Tatsukawa H, Tatum Z, Thompson M, Toyoda H, Toyodo T, Valen E, van de Wetering M, van den Berg LM, Verardo R, Vijayan D, Vorontsov IE, Wasserman WW, Watanabe S, Wells CA, Winteringham LN, Wolvetang E, Wood EJ, Yamaguchi Y, Yamamoto M, Yoneda M, Yonekura Y, Yoshida S, Zabierowski SE, Zhang PG, Zhao X, Zucchelli S, Summers KM, Suzuki H, Daub CO, Kawai J, Heutink P, Hide W, Freeman TC, Lenhard B, Bajic VB, Taylor MS, Makeev VJ, Sandelin A, Hume DA, Carninci P, Hayashizaki Y. FANTOM Consortium and the RIKEN PMI and CLST (DGT); Forrest AR, Kawaji H, Rehli M, Baillie JK, de Hoon MJ, Haberle V, Lassmann T, Kulakovskiy IV, Lizio M, Itoh M, Andersson R, Mungall CJ, Meehan TF, Schmeier S, Bertin N, Jørgensen M, Dimont E, Arner E, Schmidl C, Schaefer U, Medvedeva YA, Plessy C, Vitezic M, Severin J, Semple C, Ishizu Y, Young RS, Francescatto M, Alam I, Albanese D, Altschuler GM, Arakawa T, Archer JA, Arner P, Babina M, Rennie S, Balwierz PJ, Beckhouse AG, Pradhan-Bhatt S, Blake JA, Blumenthal A, Bodega B, Bonetti A, Briggs J, Brombacher F, Burroughs AM, Califano A, Cannistraci CV, Carbajo D, Chen Y, Chierici M, Ciani Y, Clevers HC, Dalla E, Davis CA, Detmar M, Diehl AD, Dohi T, Drabløs F, Edge AS, Edinger M, Ekwall K, Endoh M, Enomoto H, Fagiolini M, Fairbairn L, Fang H, Farach-Carson MC, Faulkner GJ, Favorov AV, Fisher ME, Frith MC, Fujita R, Fukuda S, Furlanello C, Furino M, Furusawa J, Geijtenbeek TB, Gibson AP, Gingeras T, Goldowitz D, Gough J, Guhl S, Guler R, Gustincich S, Ha TJ, Hamaguchi M, Hara M, Harbers M, Harshbarger J, Hasegawa A, Hasegawa Y, Hashimoto T, Herlyn M, Hitchens KJ, Ho Sui SJ, Hofmann OM, Hoof I, Hori F, Huminiecki L, Iida K, Ikawa T, Jankovic BR, Jia H, Joshi A, Jurman G, Kaczkowski B, Kai C, Kaida K, Kaiho A, Kajiyama K, Kanamori-Katayama M, Kasianov AS, Kasukawa T, Katayama S, Kato S, Kawaguchi S, Kawamoto H, Kawamura YI, Kawashima T, Kempfle JS, Kenna TJ, Kere J, Khachigian LM, Kitamura T, Klinken SP, Knox AJ, Kojima M, Kojima S, Kondo N, Koseki H, Koyasu S, Krampitz S, Kubosaki A, Kwon AT, Laros JF, Lee W, Lennartsson A, Li K, Lilje B, Lipovich L, Mackay-Sim A, Manabe R, Mar JC, Marchand B, Mathelier A, Mejhert N, Meynert A, Mizuno Y, de Lima Morais DA, Morikawa H, Morimoto M, Moro K, Motakis E, Motohashi H, Mummery CL, Murata M, Nagao-Sato S, Nakachi Y, Nakahara F, Nakamura T, Nakamura Y, Nakazato K, van Nimwegen E, Ninomiya N, Nishiyori H, Noma S, Noma S, Noazaki T, Ogishima S, Ohkura N, Ohimiya H, Ohno H, Ohshima M, Okada-Hatakeyama M, Okazaki Y, Orlando V, Ovchinnikov DA, Pain A, Passier R, Patrikakis M, Persson H, Piazza S, Prendergast JG, Rackham OJ, Ramilowski JA, Rashid M, Ravasi T, Rizzu P, Roncador M, Roy S, Rye MB, Saijyo E, Sajantila A, Saka A, Sakaguchi S, Sakai M, Sato H, Savvi S, Saxena A, Schneider C, Schultes EA, Schulze-Tanzil GG, Schwegmann A, Sengstag T, Sheng G, Shimoji H, Shimoni Y, Shin JW, Simon C, Sugiyama D, Sugiyama T, Suzuki M, Suzuki N, Swoboda RK, 't Hoen PA, Tagami M, Takahashi N, Takai J, Tanaka H, Tatsukawa H, Tatum Z, Thompson M, Toyodo H, Toyoda T, Valen E, van de Wetering M, van den Berg LM, Verado R, Vijayan D, Vorontsov IE, Wasserman WW, Watanabe S, Wells CA, Winteringham LN, Wolvetang E, Wood EJ, Yamaguchi Y, Yamamoto M, Yoneda M, Yonekura Y, Yoshida S, Zabierowski SE, Zhang PG, Zhao X, Zucchelli S, Summers KM, Suzuki H, Daub CO, Kawai J, Heutink P, Hide W, Freeman TC, Lenhard B, Bajic VB, Taylor MS, Makeev VJ, Sandelin A, Hume DA, Carninci P, Hayashizaki Y.

Is the gene DUX4 epigenetically regulated in somatic cells?

The human double-homeodomain retrogene DUX4 is expressed in the testis and epigenetically repressed in somatic tissues. Recent studies provide evidence that DUX4 is expressed in the human germline and then epigenetically silenced in somatic cells.

[22522912, 22025602, 23196547, 21288772, 21060811, 21734574, 24278031, 23143600, 23272181, 22871573, 23969240, 23593020, 24940479]

BACKGROUND: The epigenome refers to marks on the genome, including DNA methylation and histone modifications, that regulate the expression of underlying genes. A consistent profile of gene expression changes in end-stage cardiomyopathy led us to hypothesize that distinct global patterns of the epigenome may also exist. METHODS AND RESULTS: We constructed genome-wide maps of DNA methylation and histone-3 lysine-36 trimethylation (H3K36me3) enrichment for cardiomyopathic and normal human hearts. More than 506 Mb sequences per library were generated by high-throughput sequencing, allowing us to assign methylation scores to ≈28 million CG dinucleotides in the human genome. DNA methylation was significantly different in promoter CpG islands, intragenic CpG islands, gene bodies, and H3K36me3-enriched regions of the genome. DNA methylation differences were present in promoters of upregulated genes but not downregulated genes. H3K36me3 enrichment itself was also significantly different in coding regions of the genome. Specifically, abundance of RNA transcripts encoded by the DUX4 locus correlated to differential DNA methylation and H3K36me3 enrichment. In vitro, Dux gene expression was responsive to a specific inhibitor of DNA methyltransferase, and Dux siRNA knockdown led to reduced cell viability. CONCLUSIONS: Distinct epigenomic patterns exist in important DNA elements of the cardiac genome in human end-stage cardiomyopathy. The epigenome may control the expression of local or distal genes with critical functions in myocardial stress response. If epigenomic patterns track with disease progression, assays for the epigenome may be useful for assessing prognosis in heart failure. Further studies are needed to determine whether and how the epigenome contributes to the development of cardiomyopathy. Autosomal dominant facioscapulohumeral muscular dystrophy (FSHD) has an unusual pathogenic mechanism. FSHD is caused by deletion of a subset of D4Z4 macrosatellite repeat units in the subtelomere of chromosome 4q. Recent studies provide compelling evidence that a retrotransposed gene in the D4Z4 repeat, DUX4, is expressed in the human germline and then epigenetically silenced in somatic tissues. In FSHD, the combination of inefficient chromatin silencing of the D4Z4 repeat and polymorphisms on the FSHD-permissive alleles that stabilize the DUX4 mRNAs emanating from the repeat result in inappropriate DUX4 protein expression in muscle cells. FSHD is thereby the first example of a human disease caused by the inefficient repression of a retrogene in a macrosatellite repeat array. Each unit of the D4Z4 macrosatellite repeat contains a retrotransposed gene encoding the DUX4 double-homeobox transcription factor. Facioscapulohumeral dystrophy (FSHD) is caused by deletion of a subset of the D4Z4 units in the subtelomeric region of chromosome 4. Although it has been reported that the deletion of D4Z4 units induces the pathological expression of DUX4 mRNA, the association of DUX4 mRNA expression with FSHD has not been rigorously investigated, nor has any human tissue been identified that normally expresses DUX4 mRNA or protein. We show that FSHD muscle expresses a different splice form of DUX4 mRNA compared to control muscle. Control muscle produces low amounts of a splice form of DUX4 encoding only the amino-terminal portion of DUX4. FSHD muscle produces low amounts of a DUX4 mRNA that encodes the full-length DUX4 protein. The low abundance of full-length DUX4 mRNA in FSHD muscle cells represents a small subset of nuclei producing a relatively high abundance of DUX4 mRNA and protein. In contrast to control skeletal muscle and most other somatic tissues, full-length DUX4 transcript and protein is expressed at relatively abundant levels in human testis, most likely in the germ-line cells. Induced pluripotent (iPS) cells also express full-length DUX4 and differentiation of control iPS cells to embryoid bodies suppresses expression of full-length DUX4, whereas expression of full-length DUX4 persists in differentiated FSHD iPS cells. Together, these findings indicate that full-length DUX4 is normally expressed at specific developmental stages and is suppressed in most somatic tissues. The contraction of the D4Z4 repeat in FSHD results in a less efficient suppression of the full-length DUX4 mRNA in skeletal muscle cells. Therefore, FSHD represents the first human disease to be associated with the incomplete developmental silencing of a retrogene array normally expressed early in development. The human double-homeodomain retrogene DUX4 is expressed in the testis and epigenetically repressed in somatic tissues. Facioscapulohumeral muscular dystrophy (FSHD) is caused by mutations that decrease the epigenetic repression of DUX4 in somatic tissues and result in mis-expression of this transcription factor in skeletal muscle. DUX4 binds sites in the human genome that contain a double-homeobox sequence motif, including sites in unique regions of the genome as well as many sites in repetitive elements. Using ChIP-seq and RNA-seq on myoblasts transduced with DUX4 we show that DUX4 binds and activates transcription of mammalian apparent LTR-retrotransposons (MaLRs), endogenous retrovirus (ERVL and ERVK) elements, and pericentromeric satellite HSATII sequences. Some DUX4-activated MaLR and ERV elements create novel promoters for genes, long non-coding RNAs, and antisense transcripts. Many of these novel transcripts are expressed in FSHD muscle cells but not control cells, and thus might contribute to FSHD pathology. For example, HEY1, a repressor of myogenesis, is activated by DUX4 through a MaLR promoter. DUX4-bound motifs, including those in repetitive elements, show evolutionary conservation and some repeat-initiated transcripts are expressed in healthy testis, the normal expression site of DUX4, but more rarely in other somatic tissues. Testis expression patterns are known to have evolved rapidly in mammals, but the mechanisms behind this rapid change have not yet been identified: our results suggest that mobilization of MaLR and ERV elements during mammalian evolution altered germline gene expression patterns through transcriptional activation by DUX4. Our findings demonstrate a role for DUX4 and repetitive elements in mammalian germline evolution and in FSHD muscular dystrophy. Facioscapulohumeral dystrophy (FSHD) is characterized by chromatin relaxation of the D4Z4 macrosatellite array on chromosome 4 and expression of the D4Z4-encoded DUX4 gene in skeletal muscle. The more common form, autosomal dominant FSHD1, is caused by contraction of the D4Z4 array, whereas the genetic determinants and inheritance of D4Z4 array contraction-independent FSHD2 are unclear. Here, we show that mutations in SMCHD1 (encoding structural maintenance of chromosomes flexible hinge domain containing 1) on chromosome 18 reduce SMCHD1 protein levels and segregate with genome-wide D4Z4 CpG hypomethylation in human kindreds. FSHD2 occurs in individuals who inherited both the SMCHD1 mutation and a normal-sized D4Z4 array on a chromosome 4 haplotype permissive for DUX4 expression. Reducing SMCHD1 levels in skeletal muscle results in D4Z4 contraction-independent DUX4 expression. Our study identifies SMCHD1 as an epigenetic modifier of the D4Z4 metastable epiallele and as a causal genetic determinant of FSHD2 and possibly other human diseases subject to epigenetic regulation. Facioscapulohumeral muscular dystrophy (FSHD) is a progressive muscle disorder linked to a contraction of the D4Z4 repeat array in the 4q35 subtelomeric region. This deletion induces epigenetic modifications that affect the expression of several genes located in the vicinity. In each D4Z4 element, we identified the double homeobox 4 (DUX4) gene. DUX4 expresses a transcription factor that plays a major role in the development of FSHD through the initiation of a large gene dysregulation cascade that causes myogenic differentiation defects, atrophy and reduced response to oxidative stress. Because miRNAs variably affect mRNA expression, proteomic approaches are required to define the dysregulated pathways in FSHD. In this study, we optimized a differential isotope protein labeling (ICPL) method combined with shotgun proteomic analysis using a gel-free system (2DLC-MS/MS) to study FSHD myotubes. Primary CD56(+) FSHD myoblasts were found to fuse into myotubes presenting various proportions of an atrophic or a disorganized phenotype. To better understand the FSHD myogenic defect, our improved proteomic procedure was used to compare predominantly atrophic or disorganized myotubes to the same matching healthy control. FSHD atrophic myotubes presented decreased structural and contractile muscle components. This phenotype suggests the occurrence of atrophy-associated proteolysis that likely results from the DUX4-mediated gene dysregulation cascade. The skeletal muscle myosin isoforms were decreased while non-muscle myosin complexes were more abundant. In FSHD disorganized myotubes, myosin isoforms were not reduced, and increased proteins were mostly involved in microtubule network organization and myofibrillar remodeling. A common feature of both FSHD myotube phenotypes was the disturbance of several caveolar proteins, such as PTRF and MURC. Taken together, our data suggest changes in trafficking and in the membrane microdomains of FSHD myotubes. Finally, the adjustment of a nuclear fractionation compatible with mass spectrometry allowed us to highlight alterations of proteins involved in mRNA processing and stability. In most cases facioscapulohumeral muscular dystrophy (FSHD) is caused by contraction of the D4Z4 repeat in the 4q subtelomere. This contraction is associated with local chromatin decondensation and derepression of the DUX4 retrogene. Its complex genetic and epigenetic cause and high clinical variability in disease severity complicate investigations on the pathogenic mechanism underlying FSHD. A validated cellular model bypassing the considerable heterogeneity would facilitate mechanistic and therapeutic studies of FSHD. Taking advantage of the high incidence of somatic mosaicism for D4Z4 repeat contraction in de novo FSHD, we have established a clonal myogenic cell model from a mosaic patient. Individual clones are genetically identical except for the size of the D4Z4 repeat array, being either normal or FSHD sized. These clones retain their myogenic characteristics, and D4Z4 contracted clones differ from the noncontracted clones by the bursts of expression of DUX4 in sporadic nuclei, showing that this burst-like phenomenon is a locus-intrinsic feature. Consequently, downstream effects of DUX4 expression can be observed in D4Z4 contracted clones, like differential expression of DUX4 target genes. We also show their participation to in vivo regeneration with immunodeficient mice, further expanding the potential of these clones for mechanistic and therapeutic studies. These cell lines will facilitate pairwise comparisons to identify FSHD-specific differences and are expected to create new opportunities for high-throughput drug screens. Facioscapulohumeral dystrophy (FSHD) is a progressive muscular dystrophy caused by decreased epigenetic repression of the D4Z4 macrosatellite repeats and ectopic expression of DUX4, a retrogene encoding a germline transcription factor encoded in each repeat. Unaffected individuals generally have more than 10 repeats arrayed in the subtelomeric region of chromosome 4, whereas the most common form of FSHD (FSHD1) is caused by a contraction of the array to fewer than 10 repeats, associated with decreased epigenetic repression and variegated expression of DUX4 in skeletal muscle. We have generated transgenic mice carrying D4Z4 arrays from an FSHD1 allele and from a control allele. These mice recapitulate important epigenetic and DUX4 expression attributes seen in patients and controls, respectively, including high DUX4 expression levels in the germline, (incomplete) epigenetic repression in somatic tissue, and FSHD-specific variegated DUX4 expression in sporadic muscle nuclei associated with D4Z4 chromatin relaxation. In addition we show that DUX4 is able to activate similar functional gene groups in mouse muscle cells as it does in human muscle cells. These transgenic mice therefore represent a valuable animal model for FSHD and will be a useful resource to study the molecular mechanisms underlying FSHD and to test new therapeutic intervention strategies. Although the pathophysiology of facioscapulohumeral dystrophy (FSHD) has been controversial over the last decades, progress in recent years has led to a model that incorporates these decades of findings and is gaining general acceptance in the FSHD research community. Here we review how the contributions from many labs over many years led to an understanding of a fundamentally new mechanism of human disease. FSHD is caused by inefficient repeat-mediated epigenetic repression of the D4Z4 macrosatellite repeat array on chromosome 4, resulting in the variegated expression of the DUX4 retrogene, encoding a double-homeobox transcription factor, in skeletal muscle. Normally expressed in the testis and epigenetically repressed in somatic tissues, DUX4 expression in skeletal muscle induces expression of many germline, stem cell, and other genes that might account for the pathophysiology of FSHD. Although some disagreements regarding the details of mechanisms remain in the field, the coalescing agreement on a central model of pathophysiology represents a pivot-point in FSHD research, transitioning the field from discovery-oriented studies to translational studies aimed at developing therapies based on a sound model of disease pathophysiology.

What is the function of the mammalian gene Irg1?

Human IRG1 and mouse Irg1 mediates antiviral and antimicrobial immune responses, without its exact role having been elucidated. Irg1 has been suggested to have a role in apoptosis and to play a significant role in embryonic implantation. Irg1 is reported as the mammalian ortholog of methylcitrate dehydratase.

[23455712, 14500577, 7721348, 21865384, 21424586, 11356686, 15937114, 12893884, 21947773, 16415166, 19014335]

The steroid hormone progesterone (P) is a critical regulator of uterine receptivity during blastocyst implantation. The hormone acts through nuclear P receptors (PRs) to modulate the expression of specific gene networks in various uterine cell types. To identify the P-regulated pathways underlying uterine receptivity, we previously used oligonucleotide microarrays to analyze uterine mRNA profiles at the time of implantation in response to RU486, a PR antagonist. We reported that the mRNA corresponding to the immune-responsive gene 1 (Irg1), a previously described lipopolysaccharide-inducible gene, is one of the several mRNAs that are markedly down-regulated by RU486 in the preimplantation uterus. In the present study, we performed in situ hybridization to show that P stimulates Irg1 mRNA synthesis in the luminal epithelial cells of uteri of ovariectomized wild-type but not PR knockout mice. We also report that Irg1 mRNA was induced in the luminal epithelium of pregnant uterus between d 3 and 5, overlapping the window of implantation. To investigate the function of Irg1 during implantation, we administered sense or antisense oligodeoxynucleotides into preimplantation mouse uteri. Treatment with antisense oligodeoxynucleotides led to suppression in Irg1 mRNA expression without affecting unrelated mRNAs in the pregnant uterus. This intervention was also accompanied by impairment in embryo implantation, indicating that the phenotype is linked to the suppression of Irg1 mRNA. Collectively, our studies identified Irg1 as a novel target of PR in the pregnant uterus and also revealed that it is a critical regulator of the early events leading to implantation. Murine immune-responsive gene 1 (IRG1) plays significant roles in embryonic implantation and neurodegeneration. The expression pattern of the human IRG1 gene, however, has not yet been established, and the predicted gene sequence has been revised several times according to computed expressed sequence tags (ESTs). To determine the human IRG1 gene expression profile, human fetal tissue samples, peripheral blood mononuclear cells (PBMCs) from normal healthy subjects, and the human leukemia cell lines THP-1 and K-562 challenged with lipopolysaccharide (LPS) were subjected to RT-PCR using degenerate primers. The results indicated that the IRG1 gene is differentially expressed in human fetal PBMCs and LPS-stimulated adult PBMCs. The amplified gene fragment was cloned into the pET32a(+) vector and fusion-expressed with a His-tag in a prokaryotic system. After affinity chromatography, human IRG1h fusion proteins were isolated by SDS-PAGE and identified by mass spectrometric analysis for use as an immunogen to immunize rabbits. The titer and specificity of the purified rabbit antiserum were sufficient to measure human IRG1 gene expression in various tissues and cultures. This purified polyclonal antiserum will allow us to initiate studies to elucidate the biological roles of the human IRG1 gene. Implantation of the developing blastocyst is regulated by multiple effectors, such as steroid hormones, growth factors, and cytokines. To understand how these diverse signaling pathways interact to modulate uterine gene expression, we employed a gene expression screen technique to identify the molecules that are induced in the periimplantation rat uterus. Here we report the isolation of a complementary DNA representing a novel gene, interferon-regulated gene 1 (IRG1). This gene exhibits significant homology to interferon (IFN)-alpha/beta-inducible human genes p27 and 6-16, indicating that these genes may belong to the same family. Consistent with this finding, expression of IRG1 messenger RNA (mRNA) in rat uterus increased about 20-fold in response to IFNalpha. Uterine expression of IRG1 was also stimulated by estrogen and was partially inhibited by an antiestrogen, ICI 182,780. In pregnant rats, IRG1 expression was high on day 1, but declined on days 2 and 3. The level of IRG1 mRNA again rose transiently on day 4 immediately preceding implantation. In situ hybridization analysis localized the IRG1 mRNA expression in the endometrial epithelium and the surrounding stroma. Interestingly, the expression of p27, which shows high homology to IRG1, was strongly enhanced in human endometrium during the midsecretory phase of the menstrual cycle, overlapping the putative window of implantation. Both IRG1 and p27 mRNAs are therefore induced in the endometrium in an implantation stage-specific manner. We also observed a synergistic interaction between IFNalpha and estrogen receptor signaling pathways that led to maximal induction of p27 mRNA in Ishikawa cells. Although the functional roles of IRG1 and p27 remain unclear, we describe for the first time, identification of a gene family regulated by IFNalpha in both rodent and human uteri. More importantly, our studies reveal that a complex interplay between the steroid hormone and IFN pathways regulates the expression of these genes in the endometrium at the time of implantation. Activation of the receptors for leukemia inhibitory factor (LIF) and IL-11 is essential for embryo attachment and decidualization in mice. Both receptors induce activation of the Stat family of signal transducers via the Jak/Stat pathway. Here, we aimed to establish whether activation of Stat3 in maternal endometrium is essential for successful implantation. Functional blockade of Stat3 before implantation, by injection into the uterine lumen of a cell-permeable Stat3 peptide inhibitor, reduced embryo implantation specifically by 70% (P < 0.001). Stat3 is phosphorylated in the luminal epithelium (LE) in response to LIF, and this phosphorylation was significantly reduced both in vitro and in vivo by the Stat3 inhibitor. The inhibitor also blocked induction by LIF of several LIF-regulated genes in the LE including Irg1, which has been shown previously to be essential for implantation. Successful implantation is therefore dependent on phosphorylation and activation of Stat3 in the endometrium before implantation. This finding provides a target for contraceptive development, based on selective blockade of signal transduction pathways essential for implantation. This study demonstrates that cell-permeable peptide inhibitors can be used effectively to target intracellular signaling pathways in the uterine LE. Implantation requires coordination between development of the blastocyst and the sex steroid hormone-regulated differentiation of the uterus. Under the influence of these hormones, the uterine luminal epithelium becomes receptive to attachment of the hatched blastocyst. In this study we sought to identify genes regulated by progesterone (P4) in the uterine epithelium. This resulted in the identification of one novel P4-regulated gene that had been previously found in lipopolysaccharide-stimulated macrophages and called immune response gene-1 (Irg1) and which is the mammalian ortholog of the bacterial gene encoding methylcitrate dehydratase. In adult mice Irg1 expression was limited to the uterine luminal epithelium where it is expressed only during pregnancy with a peak coinciding with implantation. Irg1 mRNA expression is regulated synergistically by P4 and estradiol (E2) but not by E2 alone. In macrophages Irg1 is induced by lipopolysaccharide through a protein kinase C (PKC)-regulated pathway. Now we demonstrate that the PKC pathway is induced in the uterine epithelium at implantation by the synergistic action of P4 and E2 and is responsible for the hormone induction of Irg1. These results suggest that the PKC pathway plays an important role in modulating steroid hormone responsiveness in the uterine luminal epithelium during the implantation window and that Irg1 will be an important marker of this window and may play an important role in implantation. Interleukin-10 (IL-10) modulates inflammatory responses elicited in vitro and in vivo by Borrelia burgdorferi, the Lyme disease spirochete. How IL-10 modulates these inflammatory responses still remains elusive. We hypothesize that IL-10 inhibits effector functions of multiple genes induced by B. burgdorferi in macrophages to control concomitantly elicited inflammation. Because macrophages are essential in the initiation of inflammation, we used mouse J774 macrophages and live B. burgdorferi spirochetes as the model target cell and stimulant, respectively. First, we employed transcriptome profiling to identify genes that were induced by stimulation of cells with live spirochetes and that were perturbed by addition of IL-10 to spirochete cultures. Spirochetes significantly induced upregulation of 347 genes at both the 4-h and 24-h time points. IL-10 inhibited the expression levels, respectively, of 53 and 65 of the 4-h and 24-h genes, and potentiated, respectively, at 4 h and 24 h, 65 and 50 genes. Prominent among the novel identified IL-10-inhibited genes also validated by quantitative real-time PCR (qRT-PCR) were Toll-like receptor 1 (TLR1), TLR2, IRAK3, TRAF1, IRG1, PTGS2, MMP9, IFI44, IFIT1, and CD40. Proteome analysis using a multiplex enzyme-linked immunosorbent assay (ELISA) revealed the IL-10 modulation/and or potentiation of RANTES/CCL5, macrophage inflammatory protein 2 (MIP-2)/CXCL2, IP-10/CXCL10, MIP-1α/CCL3, granulocyte colony-stimulating factor (G-CSF)/CSF3, CXCL1, CXCL5, CCL2, CCL4, IL-6, tumor necrosis factor alpha (TNF-α), IL-1α, IL-1β, gamma interferon (IFN-γ), and IL-9. Similar results were obtained using sonicated spirochetes or lipoprotein as stimulants. Our data show that IL-10 alters effectors induced by B. burgdorferi in macrophages to control concomitantly elicited inflammatory responses. Moreover, for the first time, this study provides global insight into potential mechanisms used by IL-10 to control Lyme disease inflammation. Mycobacterium avium subspecies paratuberculosis (MAP) causes a chronic enteritis in ruminants. In addition, MAP is presently the most favored pathogen linked to Crohn's disease. In this study, we were interested in dissecting the molecular mechanisms of macrophage activation or deactivation after infection with MAP. By subtractive hybridization of cDNAs, we identified the immune-responsive gene 1 (IRG1), which was expressed substantially higher in lipopolysaccharide (LPS)-stimulated than in MAP-infected murine macrophage cell lines. A nuclear run-on transcription assay revealed that the IRG1 gene was activated transcriptionally in LPS-stimulated and MAP-infected macrophages with higher expression in LPS-stimulated cells. Analysis of post-transcriptional regulation demonstrated that IRG1 mRNA stability was increased in LPS-stimulated but not in MAP-infected macrophages. Furthermore, IRG1 gene expression of macrophages infected with the nonpathogenic Mycobacterium smegmatis differed from those of LPS-stimulated and MAP-infected macrophages. At 2 h postinfection, M. smegmatis-induced IRG1 gene expression was as low as in MAP-infected, and 8 h postinfection, it increased nearly to the level in LPS-stimulated macrophages. Transient transfection experiments revealed similar IRG1 promoter activities in MAP- and M. smegmatis-infected cells. Northern analysis demonstrated increased IRG1 mRNA stability in M. smegmatis-infected macrophages. IRG1 mRNA stabilization was p38 mitogen-activated protein kinase-independent. Inhibition of protein synthesis revealed that constitutively expressed factors seemed to be responsible for IRG1 mRNA destabilization. Thus, our data demonstrate that transcriptional and post-transcriptional mechanisms are responsible for a differential IRG1 gene expression in murine macrophages treated with LPS, MAP, and M. smegmatis. Interferon-gamma (IFN-gamma) and tumor necrosis factor (TNF) are essential cytokines for successful clearance of microbial infections. Activation of macrophages by synergistic effects of these cytokines leads to induction of antimicrobial effector systems like reactive oxygen and reactive nitrogen intermediates. Strikingly, IFN-gammaR(-/-) and TNFRp55(-/-) mice are considerably more susceptible to infections than inducible nitric oxide synthase(-/-) and p47phox(-/-) mice. Thus we applied transcriptome-profiling studies to identify genes synergistically upregulated by IFN-gamma and TNF in macrophages which are potentially involved in the defense against intracellular pathogens. From a total of 234 regulated genes we found 35 genes that were upregulated by combined effects of IFN-gamma and TNF and were at least 2-fold induced. The majority of these genes are involved in signal transduction and transcriptional regulation. However, we found several genes were poorly characterized with regard to immunological functions. As a prototypic TNF- and IFN-gamma-coregulated gene we characterized the expression and the subcellular localization of immunoresponsive gene 1 (IRG1) in murine macrophages. IRG1 is highly upregulated in murine ANA-1 macrophages by several proinflammatory cytokines and Toll-like receptor (TLR) agonists, as well as in spleen and lung of Listeria monocytogenes or Toxoplasma gondii infected mice, respectively. Furthermore, this study identifies 35 genes that constitute the IFN-gamma/TNF-triggered effector program in innate immunity.

Have hESC been tested for the treatment of age-related macular degeneration?

Yes, human embryonic stem cell (hESC) therapies are being assessed for age-related macular degeneration (AMD).

[25273541, 22281388, 23601133, 20709808, 22514096, 19521979]

Age-related macular degeneration (AMD) is the leading cause of vision loss in older adults and ultimately leads to the death of photoreceptor cells in the macular area of the neural retina. Currently, treatments are only available for patients with the wet form of AMD. In this review, we describe recent approaches to develop cell-based therapies for the treatment of AMD. Recent research has focused on replacing the retinal pigment epithelium (RPE), a monolayer of cells vital to photoreceptor cell health. We discuss the various methods used to differentiate and purify RPE from human embryonic stem cells (HESC), and describe the surgical approaches being used to transplant these cells in existing and forthcoming clinical trials. Age-related macular degeneration (AMD) is characterized by the loss or dysfunction of retinal pigment epithelium (RPE) and is the most common cause of vision loss among the elderly. Stem-cell-based strategies, using human embryonic stem cells (hESCs) or human-induced pluripotent stem cells (hiPSCs), may provide an abundant donor source for generating RPE cells in cell replacement therapies. Despite a significant amount of research on deriving functional RPE cells from various stem cell sources, it is still unclear whether stem-cell-derived RPE cells fully mimic primary RPE cells. In this report, we demonstrate that functional RPE cells can be derived from multiple lines of hESCs and hiPSCs with varying efficiencies. Stem-cell-derived RPE cells exhibit cobblestone-like morphology, transcripts, proteins and phagocytic function similar to human fetal RPE (fRPE) cells. In addition, we performed global gene expression profiling of stem-cell-derived RPE cells, native and cultured fRPE cells, undifferentiated hESCs and fibroblasts to determine the differentiation state of stem-cell-derived RPE cells. Our data indicate that hESC-derived RPE cells closely resemble human fRPE cells, whereas hiPSC-derived RPE cells are in a unique differentiation state. Furthermore, we identified a set of 87 signature genes that are unique to human fRPE and a majority of these signature genes are shared by stem-cell-derived RPE cells. These results establish a panel of molecular markers for evaluating the fidelity of human pluripotent stem cell to RPE conversion. This study contributes to our understanding of the utility of hESC/hiPSC-derived RPE in AMD therapy.

What disease in Loxapine prominently used for?

The best indication of loxapine is paranoid schizophrenia.

[22014696, 7914051]

Since the beginning of the neuroleptics in 1952, French psychiatrists have proposed a classification of neuroleptics, taking into account the pharmacological and therapeutic differences between these drugs. They distinguished 3 different clinical effects of neuroleptics: sedative effects, effects on the positive symptoms of schizophrenia and effects on the negative symptoms. The effect of some neuroleptics on negative symptoms is recognized by the international community, which considers clozapine to be effective. In France, in most cases, the indication of clozapine is still refractory paranoid schizophrenia. The effect of this atypical neuroleptic on other types of schizophrenic patient is not well known. Remoxipride appears to be as effective in treating psychotic symptoms and to have fewer side effects than haloperidol. Remoxipride is effective for both positive and negative symptoms. Loxapine has been prescribed in France since 1980. Its pharmacological profile is close to that of clozapine: it has dopamine (D2), histamine (H1), serotonin (5-HT2) and adrenergic (alpha 1)-blocking activities. Its best indication seems to be paranoid schizophrenia, although some data suggest bipolar action. The bipolar action of some new neuroleptics is illustrated by amisulpride, a substitute benzamide derivative. The originality of this molecule lies in its two opposite actions at two distinct doses. Doses of 600-1200 mg/day are effective against positive symptoms; 50-150 mg/day improves negative symptoms. This latter effect could be mediated by activation of the dopamine system.(ABSTRACT TRUNCATED AT 250 WORDS)

What is the systemic nickel allergy syndrome?

A severe form of this allergy is the Systemic nickel allergy syndrome, clinically characterized by cutaneous manifestions (contact dermatitis, pompholyx, hand dermatitis dyshydrosis, urticaria) with chronic course and systemic symptoms (headache, asthenia, itching, and gastrointestinal disorders related to histopathological alterations of gastrointestinal mucosa, borderline with celiac disease).

[21409856, 23405604, 22652902, 24256166, 23393800, 24067467, 22217998, 19843408, 23527730, 20378005, 21658331]

Nickel is a very common metal contained in many everyday objects and is the leading cause of ACD (Allergic Contact Dermatitis). Nickel is present in most of the constituents of a normal diet, but some food groups are usually considered to be richer. However, the nickel content of specific food can vary widely, depending on many factors. Thus, the daily intake of nickel is also highly variable both among different populations and in a single individual, in different seasons and even in different days. Measuring precisely the daily intake of nickel from food and drinks is extremely difficult, if not impossible. The relationship between ACD and contact with nickel is undisputed and widely confirmed in literature. The situation is different for systemic nickel allergy syndrome (SNAS). The SNAS can have cutaneous signs and symptoms (Systemic Contact Dermatitis or SCD) or extracutaneous signs and symptoms (gastrointestinal, respiratory, neurological, etc.).The occurrence of SCD as a systemic reaction to the nickel normally assumed in the daily diet is very controversial. A rigorous demonstration of the relationship between SCD and nickel is extremely difficult. In particular, further and larger studies are needed to assess the reality and the prevalence of nickel urticaria. With respect to nickel-related gastrointestinal symptoms, as well as chronic fatigue syndrome, fibromyalgia, headache, recurring cold sores and recurrent infections in general, the data available in literature are not conclusive and the studies lack the support of clear, first-hand evidence. With respect to respiratory disorders, the role of food nickel and the effectiveness of a dietary treatment have been assumed but not proven. In fact, the usefullness of a therapeutic low-nickel diet is controversial: rare, if not exceptional, and limited to very sporadic cases of SCD. Additionally, the quantitative and qualitative composition of a low-nickel diet presents few certainties and many uncertainties. The low-nickel diets suggested in literature are highly variable, both in the extension of the restrictions and in their details--and the differences are not marginal. CONCLUSION: an evaluation of the data presented by medical literature about SNAS and its relationship with oral nickel does not allow to draw final conclusions. In the absence of genuine certainty we can only conclude that further and broader studies, more rigorously conducted, are needed. Subjects with Nickel sensitization proved by patch test may suffer of contact eczema, but also of a Sistemic Nickel Allergy Syndrome (SNAS) consisting of urticaria-like troubles, itch, erythema, cutaneous rush, headache, intestinal symptoms, recurrent vesicular palmar dermatitis. 160 subjects (130 F, 30 M) were classified into three groups and underwent dosage of Nickel in urines (U-Ni) and blood (B-Ni). The two groups with SNAS showed an higher indicators of Nickel absorption, while the only-eczema group did not. 95 subjects with SNAS were enrolled for a Nickel-scanty diet: most of them improved. 24 ones again symptomatic were admitted to an experimental treatment, by a schedule of oral increasing microdose (nanograms) of Nickel sulphate: all of them improved. In conclusion Nickel pathology is changing, allergy seems to be due to different mechanism, dietary intake is important, an immune-tolerance can be induced. BACKGROUND: This is the first randomized, double-blind, placebo-controlled trial (EUDRACT No. 2009-013923-43) evaluating nickel oral hyposensitizing treatment (NiOHT) in patients with "systemic nickel allergy syndrome" (SNAS), characterized by Ni-allergic contact dermatitis and systemic reactions after eating Ni-rich food. METHODS: Adults with positive Ni-patch test, who reported symptoms suggesting SNAS, which improved after Ni-poor diet, and were positive to Ni-oral challenge were eligible. Patients were randomly assigned to three treatments (1.5 μg, 0.3 μg, or 30 ng Ni/week) or placebo for a year, with progressive reintroduction of Ni-rich foods form the 5(th) month. Out of 141 patients randomized, 113 completed the trial. Endpoints were efficacy and tolerability of treatment. RESULTS: During Ni-rich food re-introduction, the 1.5 μg Ni/week group had a mean VAS score significantly higher than placebo (p = 0.044), with significant improvement of gastrointestinal symptoms (p = 0.016;) and significantly fewer rescue medications. Cutaneous manifestations also improved but without reaching statistical significance. After the treatment, oral challenge with higher Ni doses than at baseline were needed to cause symptoms to flare-up in significantly more patients given 1.5 μg Ni/week than placebo (p = 0.05). Patients reported no side-effects. CONCLUSIONS: NiOHT is effective in SNAS, in particular on gastrointestinal manifestations, with trend toward improvement of cutaneous symptoms. Nowadays nickel is a global problem, related to occupations (mainly metalworkers) and to life habits. The dietary intake, more than environments, is the source of a basic immune identification and also of possible complications after occupational inhalation or contact. Nickel insoluble compounds are proved to be cancerogenic. Nickel ions are very reactive with proteins and oxidant, then also potential irritant for the airways. Metallic nickel and soluble compounds are sensitizers, causing dermatitis, rhinitis and asthma. Recently a Systemic Nickel Allergy Syndrome (SNAS) has been identified in allergic subjects, with a clinical picture of urticaria, general hitching, headache, gastrointestinal troubles. SNAS may affect allergic occupational or non-occupational ones. Studies are in progress aimed to an oral treatment inducing immunotolerance. Nickel in urine seems to be the best tool for monitoring nickel absorption. Systemic (gastrointestinal and skin) reactions to ingestion of nickel rich foods in patients with nickel allergic contact dermatitis characterize Systemic Nickel Allergy Syndrome (SNAS). The objective of the study was to describe the nosologic framework of the syndrome and to compare sensibility and specificity for SNAS diagnosis between two different low nickel diets - BraMa-Ni and the usually prescribed list of forbidden foods - along with patient adherence to diet. One hundred forty-five patients with suspected SNAS (by history and benefit from nickel dietary restrictions) were selected and orally challenged with nickel for a definite diagnosis. Specificity and sensibility of the diets were calculated in relation to the results of nickel challenges. The nosologic framework of SNAS was deduced from the clinical pictures of 98 patients with positive nickel challenge and characterized essentially by skin and gastrointestinal symptoms, whereas all other symptoms (dizziness, headache etc.) were never elicited by the oral nickel challenge. The specificity and sensibility of BraMa-Ni in detecting SNAS were significantly higher than the forbidden food list diet, with an excellent patient adherence. Therefore, BraMa-Ni diet can be prescribed for the treatment of the syndrome other than for the diagnosis, the gold standard of which remains the oral nickel challenge. Some patients with nickel (Ni) allergic contact dermatitis (ACD) suffer from systemic symptoms after ingestion of Ni-rich foods, a condition termed Systemic Nickel Allergy Syndrome (SNAS). The aim of this study is to investigate in children the relationship between Ni ACD and lymphocyte subsets or susceptibility to infections. Nineteen children with Ni ACD and 18 controls matched for sex and age were enrolled. All participants underwent patch test, skin prick test and clinical assessment. Serum immunoglobulins and flow cytometry for lymphocyte subset study were also evaluated. In children with Ni ACD a higher incidence of recurrent upper respiratory tract infections and recurrent otitis media were detected. Serum levels of immunoglobulins and lymphocyte subsets did not show significant changes (p>0.05) between the two groups studied. We can hypothesize that in children with Ni ACD the risk of recurrent infections is increased. Although the clinical manifestations of SNAS are still controversial, we can suppose that recurrent infections may be considered a clinical symptom of this syndrome. Nickel sensitization can not only induce allergic contact dermatitis (ACD), but also can induce an overlapping disease referred to as "systemic nickel allergy syndrome" (SNAS), characterized by urticaria/angioedema and gastrointestinal symptoms correlated to the ingestion of nickel-containing foods. This study was designed to determine if oxidative stress occurs in patients with nickel allergy. Thirty-one female patients (mean age 31.26 + 13.04 years, range 16-64 years) with confirmed nickel CD underwent oral nickel challenge because of clinically suspected SNAS; serum concentrations of protein carbonyl groups (PCGs) and nitrosylated proteins (NPs; biomarkers of oxidative stress) were measured before and after oral nickel challenge as well as in healthy female controls. Twenty-three of these 31 patients were diagnosed with SNAS because they had a positive reaction to the oral nickel challenge, and 8 patients had no reaction and therefore were classified as patients with contact nickel allergy only. Although both nickel-allergic patients and controls presented similar serum levels of PCGs, NP values in nickel-allergic patients appeared higher than in controls and tended to decrease after the challenge; furthermore, serum levels of NPs in patients affected by SNAS were higher (although not significantly) than in patients with nickel ACD only. The involvement of specific biomarkers of oxidative stress such as NPs and the lack of involvement of other biomarkers such as PCGs may help to better understand the alteration of the redox homeostasis occurring in nickel ACD and particularly in SNAS. Nickel ingested with food can elicit either systemic cutaneous or gastrointestinal symptoms causing a systemic nickel allergy syndrome (SNAS) that can be treated with tolerance by oral ingestion of the metal. It has been suggested that interleukins 2 (IL-2) and 10 (IL-10) are involved in the mechanisms underlying oral tolerance. We evaluated the clinical efficacy of oral desensitization therapy in SNAS consisting in the administration of nickel sulphate. Because nickel allergy prevalently affects women, only female subjects (N = 22) were recruited. Oral nickel desensitizing therapy was associated with low-nickel diet for three months. Before and after therapy, clinical conditions were evaluated, and circulating cytokines IL-2 and IL-10 were measured. After the two-year treatment, visual analogue scale (VAS) scores for symptoms were significantly reduced (P less than 0.001). Patients were released by either cutaneous or gastrointestinal symptoms and by tolerating nickel-containing food. At the end of the treatment, nickel oral challenge test was negative in 18 patients, and IL-2 level in the serum was significantly reduced while IL-10 was increased, although this datum was not statistically significant. Our study confirms the clinical efficacy of nickel oral immunotherapy and focuses on the mechanisms triggered by oral tolerance indicating that reduction of IL-2 can be associated with success of oral nickel desensitizing therapy. Some patients with nickel (Ni) allergic contact dermatitis suffer from systemic (intestinal or cutaneous) symptoms after ingestion of Ni-rich foods and experience symptoms reduction with low-Ni diet, a condition termed Systemic Ni Allergy Syndrome (SNAS). We aimed at evaluating whether oral administration of low nickel doses improved clinical conditions and modulated immunological aspects of SNAS, without significant side effects. Thirty-six SNAS patients were enrolled. Treatment started after 1-month of low-Ni diet and consisted in an incremental oral NiOH dose phase (0.3ng to 1.5 microg/week) followed by a 12-months maintenance phase (1.5 microg/week). Randomly, twenty-four patients added Ni therapy to low-Ni diet and 12 remained with diet alone. All patients were allowed rescue medications (antihistamines and topical steroids). After 4 months, Ni-rich foods were gradually reintroduced. In vitro allergen-driven IL13, IL5 and IFN-gamma release by peripheral blood mononuclear cells was evaluated before and after treatment. Twenty-three patients receiving NiOH and the 12 control patients completed the study. Evaluation of SNAS clinical severity (by VAS and drug consumption) showed a significant difference in favor of NiOH-treated patients compared to controls. Twenty of 23 patients in the NiOH group and none in the control group tolerated Ni-rich food reintroduction. Release of all studied cytokines in culture supernatants was significantly lower after NiOH treatment. In conclusion NiOH is effective in reducing symptoms and drug consumption in SNAS and is able to modulate inflammatory parameters. Some patients affected by nickel-contact allergy present digestive symptoms in addition to systemic cutaneous manifestations, falling under the condition known as systemic nickel allergy syndrome (SNAS). A nickel-related pro-inflammatory status has been documented at intestinal mucosal level. The aim of the present study is to evaluate the prevalence of lactose intolerance in patients affected by SNAS compared to a healthy population. Consecutive patients affected by SNAS referring to our departments were enrolled. The control population consisted of healthy subjects without gastrointestinal symptoms. All subjects enrolled underwent lactose breath test under standard conditions. One hundred and seventy-eight SNAS patients and 60 healthy controls were enrolled. Positivity of lactose breath test occurred in 74.7% of the SNAS group compared to 6.6% of the control group. Lactose intolerance is highly prevalent in our series of patients affected by SNAS. Based on our preliminary results, we can hypothesize that in SNAS patients, the nickel-induced pro-inflammatory status could temporarily impair the brush border enzymatic functions, resulting in hypolactasia. Further trials evaluating the effect of a nickel-low diet regimen on lactase activity, histological features and immunological pattern are needed.

Which antibodies cause Riedel thyroiditis?

Riedel thyroiditis (Immunoglobulin G4-related thyroid disease) is caused by IgG4 antibodies. It is part of the spectrum of Ig4-related sclerosing disease. It is associated with fibrosis and inflammation of the thyroid gland.

[26273473, 21881964, 24783026, 22498583, 22210556, 25011997, 25224542]

Immunoglobulin (Ig)G4-related sclerosing disease (IgG4-RSD) is a new disease entity first proposed with regard to autoimmune pancreatitis. A 67-year-old male patient was examined because of weight loss and an abdominal pain. Based on the clinical characteristics, laboratory parameters and ultrasound features, we identified the diagnosis of the IgG4-related systemic disease (IgG4-RSD), that was confirmed by the histopathological analysis after the biopsy of the head of pancreas. After confirmation, we started with the corticosteroid therapy with a good clinical, biochemical and morphological response. During the previous therapy, the disturbance of glucoregulation appeared, so we had to change the modality of treatment. We decided to add Azathioprine to the therapy in a dose of 150 mg/day. We achieved a stable phase of the disease with IgG 4.37 g/l and IgG4 0.179 g/l, and with no side effects from the therapy. LEARNING POINTS: There are potential clinical applications of identifying subsets of patients with IgG4 thyroiditis (FVHT and Riedel thyroiditis).A trial of immunosuppressive therapy should be included if a resection is deemed inadvisable.In particular, cases of FVHT that mimic malignancy, tissue and serum IgG4 may provide supportive diagnostic information. Hakaru Hashimoto described 4 patients with a hitherto unknown cause for goitre, struma lymphomatosa, a century ago. He was careful to distinguish this from Riedel thyroiditis but it has become clear that fibrosis and atrophy of the thyroid are indeed components of Hashimoto thyroiditis, and in rare cases IgG4-related sclerosing disease may be an outcome. Although the cause of the lymphocytic infiltration was unknown to Hashimoto, we now know through the pioneering studies of N.R. Rose and E. Witebsky [J Immunol 1956;76:417-427] that this condition is the archetype for autoimmune destruction as a disease mechanism. In the last two decades in particular, there has been huge interest in unravelling the genetic basis for this and related autoimmune disorders. The list of polymorphisms associated with autoimmune thyroid disease grows each year, and in the case of vitiligo, which is frequently found in association with thyroid autoimmunity, we know that 27 separate susceptibility loci account for less than 20% of the heritability of this condition. Environmental and existential factors may turn out to be just as complex in number and in interactions. We can thus imagine a 'Swiss cheese' model for the causation of autoimmune thyroid disease, in which the effects of cumulative weaknesses line up - like the holes in slices of cheese - to allow the catastrophic event of autoimmune destruction to occur. More than a century has passed since the first description of Hashimoto thyroiditis (HT) as a clinicopathologic entity. HT is an autoimmune disease in which a breakdown of immune tolerance is caused by interplay of a variety of immunologic, genetic, and environmental factors. Thyrocyte injury resulting from environmental factors results in expression of new or hidden epitopes that leads to proliferation of autoreactive T and B cells. Infiltration of thyroid by these cells results in HT. In addition to the usual type of HT, several variants such as the fibrous type and Riedal thyroiditis are also recognized. The most recently recognized variant is immunoglobulin G4(+) HT, which may occur as isolated thyroid limited disease or as part of a generalized Ig4-related sclerosing disease. The relationship between HT and Riedel thyroiditis remains unclear; however, recent evidence seems to suggest that it may also be part of the spectrum of Ig4-related sclerosing disease. HT is frequently associated with papillary thyroid carcinoma and may indeed be a risk factor for developing this type of cancer. The relationship between thyroid lymphoma and HT on the other hand appears well established. Patients with IgG4-related disease (IgG4-RD) typically have elevated serum concentrations of IgG4 and share histopathologic features that are similar across affected organ(s). IgG4-RD patients frequently require prolonged treatment with glucocorticoids and are often unable to taper these medications. Traditional disease-modifying antirheumatic drugs (DMARDs) are generally ineffective. We assessed the clinical and serologic responses to B lymphocyte depletion therapy in 10 consecutive patients with steroid- and DMARD-refractory IgG4-RD.Ten patients with IgG4-RD were treated with rituximab (RTX) (2 infusions of 1000 mg, 15 days apart). Clinical improvement was assessed by monitoring the patient's ability to taper prednisone to discontinuation and to stop DMARDs; by serial measurements of total IgG and IgG subclasses; and by follow-up radiologic assessments guided by the patient's particular pattern of organ involvement. We also developed and retrospectively applied the IgG4-RD Disease Activity Index and Flare Tool.Organ involvement included the pancreas, biliary tree, aorta, salivary glands (submandibular and parotid), lacrimal glands, lymph nodes, thyroid gland, and retroperitoneum. Nine of 10 patients demonstrated striking clinical improvement within 1 month of starting RTX. One patient with advanced thyroid fibrosis associated with Riedel thyroiditis and a history of disease in multiple other organ systems did not have improvement in the thyroid gland, but the disease did not progress to involve new organs. All 10 patients were able to discontinue prednisone and DMARDs following RTX therapy. Significant decreases in IgG concentrations were observed for the IgG4 subclass only. Four patients were re-treated with RTX after 6 months because of either symptom recurrence and increasing IgG4 concentration at the time of peripheral B cell reconstitution (n = 2) or because of physician discretion (n = 2). Repeated courses of RTX maintained their effectiveness and resulted in further decreases in IgG4 concentrations. In patients who had an increased IgG4 concentration at the time of presentation, the level of serum IgG4 appeared to be a reliable measure of disease activity.IgG4-RD is an idiopathic, multiorgan inflammatory disease in which diverse organ manifestations are linked by characteristic histopathologic and immunohistochemical features. Treatment with RTX led to prompt clinical and serologic improvement in refractory IgG4-RD in all patients with active inflammation. Serial treatments with RTX may lead to progressive declines in serum IgG4 concentrations and better disease control. Serum IgG4 concentrations may remain low, and clinical disease activity may remain quiescent even after B cell reconstitution in a significant proportion of patients. Immunoglobulin G4-related sclerosing disease (IgG4-RSD) represents a recently identified inflammatory disorder in which infiltration of IgG4 plasma cells causes fibrosis in organs. While IgG4-RSD is well documented in the pancreas and other organs, it is poorly characterized in the thyroid gland. We report a case of a 48-year-old female with a fibrotic thyroid mass associated with a retroperitoneal fibrosis. Diagnosed early as Riedel disease, the high serum IgG4, immunohistopathology and decreased fibrosis with corticosteroid therapy, finally confirm for the first time, the origin of IgG4-RSD fibrosis of the thyroid.

What are the effects of ILK ablation?

Depending on the tissue or cell where ILK is ablated we see different effects: Ablation of ILK in heart results in dilated cardiomyopathy and spontaneous heart failure Ablation of ILK in fibroblasts leads to impaired healing due to a severe reduction in the number of myofibroblasts Ablation of ILK in osteoclasts inhibits bone resorption Ablation of ILK in liver results in enhanced and prolonged cell proliferation and hepatomegaly after phenobarbital administration and in abnormal histology Ablation of ILK in podocytes caused an aberrant distribution of nephrin and alpha-actinin-4

[20564195, 19575460, 22658851, 20980390, 19920070, 19349584, 16951252, 18846549, 16837631]

Following liver regeneration after partial hepatectomy, liver grows back precisely to its original mass and does not exceed it. The mechanism regulating this "hepatostat" is not clear and no exceptions have been found to date. Although pathways initiating liver regeneration have been well studied, mechanisms involved in the termination of liver regeneration are unclear. Here, we report that integrin-linked kinase (ILK) (involved in transmission of the extracellular matrix [ECM] signaling by way of integrin receptors) and/or hepatic adaptations that ensue following ILK hepatocyte-targeted removal are critical for proper termination of liver regeneration. Following partial hepatectomy (PHx), mice with a liver-specific ILK ablation (ILK-KO-Liver) demonstrate a termination defect resulting in 58% larger liver than their original pre-PHx mass. This increase in post-PHx liver mass is due to sustained cell proliferation driven in part by increased signaling through hepatocyte growth factor (HGF), and the beta-catenin pathway and Hippo kinase pathways. CONCLUSION: The data indicate that ECM-mediated signaling by way of ILK is essential in proper termination of liver regeneration. This is the first evidence of a defect leading to impaired termination of regeneration and excessive accumulation of liver weight following partial hepatectomy. Wound healing crucially relies on the mechanical activity of fibroblasts responding to TGFβ1 and to forces transmitted across focal adhesions. Integrin-linked kinase (ILK) is a central adapter recruited to integrin β1 tails in focal adhesions mediating the communication between cells and extracellular matrix. Here, we show that fibroblast-restricted inactivation of ILK in mice leads to impaired healing due to a severe reduction in the number of myofibroblasts, whereas inflammatory infiltrate and vascularization of the granulation tissue are unaffected. Primary ILK-deficient fibroblasts exhibit severely reduced levels of extracellular TGFβ1, α-smooth muscle actin (αSMA) production and myofibroblast conversion, which are rescued by exogenous TGFβ1. They are further characterized by elevated RhoA and low Rac1 activities, resulting in abnormal shape and reduced directional migration. Interference with RhoA-ROCK signaling largely restores morphology, migration and TGFβ1 levels. We conclude that, in fibroblasts, ILK is crucial for limiting RhoA activity, thus promoting TGFβ1 production, which is essential for dermal repair following injury. During development, Schwann cells (SCs) interpret different extracellular cues to regulate their migration, proliferation, and the remarkable morphological changes associated with the sorting, ensheathment, and myelination of axons. Although interactions between extracellular matrix proteins and integrins are critical to some of these processes, the downstream signaling pathways they control are still poorly understood. Integrin-linked kinase (ILK) is a focal adhesion protein that associates with multiple binding partners to link integrins to the actin cytoskeleton and is thought to participate in integrin and growth factor-mediated signaling. Using SC-specific gene ablation, we report essential functions for ILK in radial sorting of axon bundles and in remyelination in the peripheral nervous system. Our in vivo and in vitro experiments show that ILK negatively regulates Rho/Rho kinase signaling to promote SC process extension and to initiate radial sorting. ILK also facilitates axon remyelination, likely by promoting the activation of downstream molecules such as AKT/protein kinase B. A requirement for integrin-mediated adhesion in cardiac physiology is revealed through targeted deletion of integrin-associated genes in the murine heart. Here we show that targeted ablation of the integrin-linked kinase (ILK) expression results in spontaneous cardiomyopathy and heart failure by 6 wk of age. Deletion of ILK results in disaggregation of cardiomyocytes, associated with disruption of adhesion signaling through the beta1-integrin/FAK (focal adhesion kinase) complex. Importantly, the loss of ILK is accompanied by a reduction in cardiac Akt phosphorylation, which normally provides a protective response against stress. Together, these results suggest that ILK plays a central role in protecting the mammalian heart against cardiomyopathy and failure. Integrin-linked kinase (ILK) has been implicated in the pathogenesis of proteinuria and congenital nephrotic syndrome. However, the function of ILK in glomerular podocyte in a physiologic setting remains unknown. In this study, a mouse model was generated in which ILK gene was selectively disrupted in podocytes by using the Cre-LoxP system. Podocyte-specific ablation of ILK resulted in heavy albuminuria, glomerulosclerosis, and kidney failure, which led to animal death beginning at 10 wk of age. Podocyte detachment and apoptosis were not observed at 4 wk of age, when albuminuria became prominent, indicating that they are not the initial cause of proteinuria. Electron microscopy revealed an early foot process effacement, as well as morphologic abnormality, in ILK-deficient podocytes. ILK deficiency caused an aberrant distribution of nephrin and alpha-actinin-4 in podocytes, whereas the localization of podocin and synaptopodin remained relatively intact. Co-immunoprecipitation demonstrated that ILK physically interacted with nephrin to form a ternary complex, and alpha-actinin-4 participated in ILK/nephrin complex formation. Therefore, ILK plays an essential role in specifying nephrin and alpha-actinin-4 distribution and in maintaining the slit diaphragm integrity and podocyte architecture. These results also illustrate that the integrin and slit diaphragm signals in podocytes are intrinsically coupled through an ILK-dependent mechanism.

Does d-tubocurarine (d-TC) induces irreversible inhibition of nicotinic acetylcholine receptor (nAChR) at the neuromuscular junction?

The d-tubocurarine is a nondepolarizing neuromuscular blocking agent (nondepolarizing muscle relaxant - NDMR). The nondepolarizing muscle relaxants act by blocking the nicotinic acetylcholine receptors of the neuromuscular junction. The neuromuscular blocking action of tubocurarine is reversible and concentration-dependent. The inhibition of acetylcholine-induced currents by d-tubocurarine can be reversed by anticholinesterase agents, such as edrophonium and methamidophos.

[6141831, 2066280, 9788777, 11562442, 2611499, 21453711, 16931985, 9291508, 1884116, 11867382, 3781972, 12145052, 2002334]

The pharmacological diversity of the different isoforms of the nicotinic acetylcholine receptor arises from the diversity of the subunits that assemble to form the native receptors. The aim of this study was to investigate the actions of the muscle relaxants d-tubocurarine, pancuronium and vecuronium on different isoforms of nicotinic acetylcholine receptors (mouse foetal muscle, mouse adult muscle and a rat neuronal), using the Xenopus oocyte expression system. Oocytes were injected with cRNAs for alpha, beta, gamma, delta subunits (the native foetal muscle subunit combination), or with cRNAs for alpha, beta, epsilon, delta subunits (the native adult muscle subunit combination), or with cRNAs for alpha4beta2 subunits (a putative native neuronal subunit combination). Acetylcholine had a similar potency at all three subunit combinations (EC50 11.6, 17.4 and 19.1 microM, respectively). At all three receptor types, d-tubocurarine and pancuronium blocked the responses elicited by acetylcholine in a reversible manner. Furthermore, the inhibition of the acetylcholine currents for the foetal and adult nicotinic acetylcholine receptor by pancuronium and d-tubocurarine was independent of the holding voltage over the range -100 to -40 mV. In oocytes expressing the foetal muscle nicotinic acetylcholine receptors the inhibition of the current in response to 100 microM acetylcholine by 10 nM d-tubocurarine was 29 +/- 5% (mean +/- S.E.M.; n = 7), and the inhibition by 10 nM pancuronium was 39 +/- 6% (mean +/- S.E.M.; n = 8; P > 0.05 vs. d-tubocurarine). However, in the adult form of the muscle nicotinic acetylcholine receptor, 10 nM d-tubocurarine and 10 nM pancuronium were both more effective at blocking the response to 100 microM acetylcholine compared to the foetal muscle nicotinic acetylcholine receptor, with values of 55 +/- 5% (P < 0.01; n = 12) and 60 +/- 4% (P < 0.001; n = 10), respectively. Thus the developmental switch from the gamma to the epsilon subunit alters the antagonism of the nicotinic acetylcholine receptor for both pancuronium and d-tubocurarine. Vecuronium was more potent than pancuronium. One nM vecuronium reduced the response to 100 microM acetylcholine by 71 +- 6% (n = 10) for foetal and 63 +/- 5% (n = 4) for adult nicotinic acetylcholine receptors. In the alpha4beta2 neuronal nicotinic acetylcholine receptor combination, 10 nM pancuronium was a more effective antagonist of the response to 100 microM acetylcholine (69 +/- 6%, n = 6) than 10 nM d-tubocurarine (30 +/- 5%; n = 6; P < 0.05 compared to pancuronium). This is in contrast to the adult muscle nicotinic acetylcholine receptor, where pancuronium and d-tubocurarine were equieffective. The expression of the beta2 subunit with muscle alpha, epsilon and delta subunits formed a functional receptor which was blocked by pancuronium and d-tubocurarine in a similar manner to the alphabeta1epsilondelta subunit consistent with the hypothesis that the beta subunit is not a major determinant in the action of this drug at the adult muscle nicotinic acetylcholine receptor. Equilibrium conditions of neurotransmitter concentration and receptor binding are never achieved during synaptic transmission at the neuromuscular junction. Thus, it is important to determine the binding kinetics of drugs that act this synapse. Previous determinations of the dissociation rate of (+)-tubocurarine have produced inconsistent results ranging from 0.1 to 4000/s. Here, we used a direct approach to measure association (l(on)) and dissociation (l(on)) rates for two competitive antagonists (clinically used as nondepolarizing muscle relaxants), pancuronium and (+)-tubocurarine, at nicotinic acetylcholine receptors (nAChR). We made macroscopic current recordings from outside-out patches of BC3H-1 cells expressing embryonic mouse muscle nAChR. We used a three-tube rapid perfusion system to make timed applications of antagonists and acetylcholine to the patch. We made independent measurements of the equilibrium inhibition (IC(50)) and the kinetics of onset and recovery of antagonist inhibition at 20 to 23 degrees C. Rate constants were calculated from the predictions of a single (high-affinity) site model of competitive inhibition. For pancuronium: IC(50) = 5.5 +/- 0.5 nM (mean +/- S.D.), l(on) = 2.7 +/- 0.9 x 10(8) M(-1) s(-1), l(off) = 2.1 +/- 0.7/s [corrected] x 10(8)/s. For (+)-tubocurarine: IC(50) = 41 +/- 2 nM, l(on) = 1.2 +/- 0.2 x 10(8) M(-1) s(-1), l(off) = 5.9 +/- 1.3/s. The kinetic results are consistent with the equilibrium results in that l(off)/l(on) is in good agreement with the IC(50) values. All differences between the antagonists are significant at the p < 0.001 level. The higher affinity of pancuronium is caused by a faster association rate (2.2-fold) coupled with a slower dissociation rate (2.8-fold). The association rates of both antagonists are comparable with or greater than the association rate for acetylcholine binding to nAChR. AIMS: The aim of this study was to investigate the mechanism for the reversal effect of NF449 (a suramin analogue) on the neuromuscular block induced by d-tubocurarine (d-TC). MAIN METHODS: Nerve-stimulated muscle contractions and end-plate potentials were performed in mouse phrenic nerve-diaphragm preparations. Acetylcholine (ACh)-induced muscle contractions were performed in the chick biventer cervicis preparations. Presynaptic nerve terminal waveform recordings were performed in mouse triangularis sterni preparations. KEY FINDINGS: Amongst the suramin analogues in this study, only the NF449 and suramin were able to reverse the blockade effect produced by d-TC on nerve-stimulated muscle contractions. Each of these suramin analogues (NF007, NF023, NF279 and NF449) alone has no significant effect on the amplitude of nerve-stimulated muscle contractions. NF449 and suramin also showed the antagonising effects on the inhibition of end-plate potentials induced by d-TC. Furthermore, pre-treatment with NF449 can antagonise the inhibition of d-TC in ACh-induced contractions of chick biventer cervicis muscle. NF449 produced a greater rightward shift of the dose-response inhibition curve for d-TC than did suramin. Because other purinergic 2X (P2X) receptor antagonists, NF023 and NF279, do not have the reverse effects on the neuromuscular blockade of d-TC, the effect of NF449 seems irrelevant to inhibition of P2X receptors. SIGNIFICANCE: These data suggest that NF449 was able to compete with the binding of d-TC on the nicotinic ACh receptors, and the effect of NF449 was more potent than suramin in reducing the inhibition of d-TC. The structure of NF449 may provide useful information for designing potent antidotes against neuromuscular toxins. BACKGROUND: Nondepolarizing neuromuscular blocking agents (NMBAs) are extensively used in the practice of anesthesia and intensive care medicine. Their primary site of action is at the postsynaptic nicotinic acetylcholine receptor (nAChR) in the neuromuscular junction, but their action on neuronal nAChRs have not been fully evaluated. Furthermore, observed adverse effects of nondepolarizing NMBAs might originate from an interaction with neuronal nAChRs. The aim of this study was to examine the effect of clinically used nondepolarizing NMBAs on muscle and neuronal nAChR subtypes. METHODS: Xenopus laevis oocytes were injected with messenger RNA encoding for the subunits included in the human alpha1beta1epsilondelta, alpha3beta2, alpha3beta4, alpha4beta2, and alpha7 nAChR subtypes. The interactions between each of these nAChR subtypes and atracurium, cisatracurium, d-tubocurarine, mivacurium, pancuronium, rocuronium, and vecuronium were studied using an eight-channel two-electrode voltage clamp setup. Responses were measured as peak current and net charge. RESULTS: All nondepolarizing NMBAs inhibited both muscle and neuronal nAChRs. The neuronal nAChRs were reversibly and concentration-dependently inhibited in the low micromolar range. The mechanism (i.e., competitive vs. noncompetitive) of the block at the neuronal nAChRs was dependent both on subtype and the NMBA tested. The authors did not observe activation of the nAChR subtypes by any of the NMBAs tested. CONCLUSIONS: The authors conclude that nondepolarizing NMBAs concentration-dependently inhibit human neuronal nAChRs. The inhibition of the presynaptic alpha3beta2 nAChR subtype expressed at the motor nerve ending provides a possible molecular explanation for the tetanic and train-of-four fade seen during a nondepolarizing neuromuscular block. 1. Although (+)-tubocurarine (Tc) is classically considered to be a competitive antagonist at the neuromuscular junction, kinetic details of the interaction remain unclear. 2. We studied the competitive action of Tc on the nicotinic receptor at the frog neuromuscular junction using a quantitative analysis of the generation phase of miniature endplate currents (m.e.p.cs) recorded in Ringer solution (20 degrees C) under voltage clamp (-90 mV) in the absence or presence of 1-5 microM Tc. Under control conditions four neurotransmission parameters were estimated by non-linear regression using a mathematical model of synaptic transmission incorporating transmitter release, diffusion, hydrolysis, receptor binding and channel gating. These parameters were then used in a further regression to estimate binding rate constants for Tc at the same endplate. Allowance was made for open channel block by Tc, which under the conditions of this study was only a small component of total blockade. 3. The results suggest that Tc binds to the two agonist recognition sites on the nicotinic receptor with equal affinity (stoichiometric KDs of 2.2 and 8.8 microM), and that most of the functional blockade at concentrations up to 5 microM is due to occupancy of only one site. 4. The association rate constant for Tc binding to sites on the nicotinic acetylcholine receptor appears to be very fast (k+D = 8.9 x 10(8) M-1 s-1) and comparable to that for acetylcholine (ACh). 5. In the brief time during which an m.e.p.c. is generated (approximately 200 microseconds, reversal of Tc blockade by transiently high concentrations of ACh seems to be kinetically limited. We studied the inhibition of fetal (gamma-nAChR) and adult (epsilon-nAChR) muscle-type nicotinic acetylcholine receptors by the two new nondepolarizing muscle relaxants (NDMRs) rocuronium and rapacuronium, the metabolite 3-desacetyl rapacuronium (Org 9488), and five other, longer-used NDMRs (pancuronium, vecuronium, mivacurium, d-tubocurarine, and gallamine). Receptors were expressed in Xenopus laevis oocytes by cytoplasmic injection of subunit complementary RNAs. Functional channels were activated with 10 microM acetylcholine, alone or in combination with various concentrations of the NDMRs. Currents were recorded with a whole-cell two-electrode voltage clamp technique. All NDMRs reversibly inhibited acetylcholine-activated currents in a dose-dependent fashion. Potencies of rapacuronium and Org 9488 were not statistically different at either gamma-nAChR (half-maximal response = 58.2 and 36.5 nM, respectively) or epsilon-nAChR (half-maximal response = 80.3 and 97.7 nM, respectively). The rank order of potencies at the epsilon-nAChR (pancuronium > vecuronium similar mivacurium > rocuronium similar d-tubocurarine > rapacuronium similar Org 9488 > gallamine) correlated highly with the clinical doses needed to produce 50% twitch depression at the adductor pollicis muscle in adults. Neuromuscular blockade by rapacuronium may be enhanced by its metabolite Org 9488. Different drug-receptor affinities of the tested NDMRs contribute to the differences in clinical dose requirements of these drugs needed to achieve appropriate muscle relaxation. IMPLICATIONS: Potencies of nondepolarizing muscle relaxants, studied at muscle nicotinic acetylcholine receptors expressed in a recombinant expression system, correlate highly with the clinical doses needed in adults to produce 50% twitch depression at the adductor pollicis muscle. Volatile anesthetics enhance the neuromuscular blockade produced by nondepolarizing muscle relaxants (NDMRs). The neuromuscular junction is a postulated site of this interaction. We tested the hypothesis that volatile anesthetic enhancement of muscle relaxation is the result of combined drug effects on the nicotinic acetylcholine receptor. The adult mouse muscle nicotinic acetylcholine receptor (alpha(2), beta, delta, epsilon) was heterologously expressed in Xenopus laevis oocytes. Concentration-effect curves for the inhibition of acetylcholine-induced currents were established for vecuronium, d-tubocurarine, isoflurane, and sevoflurane. Subsequently, inhibitory effects of NDMRs were studied in the presence of the volatile anesthetics at a concentration equivalent to half the concentration producing a 50% inhibition alone. All individually tested compounds produced rapid and readily reversible concentration-dependent inhibition. The calculated 50% inhibitory concentration values were 9.9 nM (95% confidence interval [CI], 8.4-11.4 nM), 43.4 nM (95% CI, 33.6-53.3 nM), 897 microM (95% CI, 699-1150 microM), and 818 microM (95% CI, 685-1001 microM) for vecuronium, d-tubocurarine, isoflurane, and sevoflurane, respectively. Coapplication of either isoflurane or sevoflurane significantly enhanced the inhibitory effects of vecuronium and d-tubocurarine, especially so at small concentrations of NDMRs. Volatile anesthetics increase the potency of NDMRs, possibly by enhancing antagonist affinity at the receptor site. This effect may contribute to the clinically observable enhancement of neuromuscular blockade by volatile anesthetics. IMPLICATIONS: Isoflurane and sevoflurane enhance the receptor blocking effects of nondepolarizing muscle relaxants on nicotinic acetylcholine receptors. Studies were conducted to ascertain the temporal and dose-dependent effects of nicotinic ligand exposure on functional activity of different nicotinic acetylcholine receptor (nAChR) subtypes, as expressed by cells of the PC12 rat pheochromocytoma (ganglia-type nAChR) or the TE671/RD human (muscle-type nAChR) clonal line. Chronic (3-72-h) agonist (nicotine or carbamylcholine) treatment of cells led to a complete (TE671) or nearly complete (PC12) loss of functional nAChR responses, which is referred to as "functional inactivation." Some inactivation of nAChR function was also observed for the nicotinic ligands d-tubocurarine (d-TC), mecamylamine, and decamethonium. Half-maximal inactivation of nAChR function was observed within 3 min for TE671 cells and within 10 min for PC12 cells treated with inactivating ligands. Functional inactivation occurred with dose dependencies that could not always be reconciled with those obtained for acute agonist activation of nAChR function or for acute inhibition of those responses by d-TC, decamethonium, or mecamylamine. Treatment of TE671 or PC12 cells with the nicotinic antagonist pancuronium or alcuronium alone had no effect on levels of expression of functional nAChRs. However, evidence was obtained that either of these antagonists protected TE671 cell muscle-type nAChRs or PC12 cell ganglia-type nAChRs from functional inactivation on long-term treatment with agonists. Recovery of TE671 cell nAChR function following treatment with carbamylcholine, nicotine, or d-TC occurred with half-times of 1-3 days whether cells were maintained in situ or harvested and replated after removal of ligand. By contrast, 50% recovery of functional nAChRs on PC12 cells occurred within 2-6 h after drug removal. In either case the time course for recovery from nAChR functional inactivation is much slower than recovery from nAChR "functional desensitization," which is a reversible process that occurs on shorter-term (0-5-min) agonist exposure of cells. These results indicate that ganglia-type and muscle-type nAChRs are similar in their sensitivities to functional inactivation by nicotinic ligands but differ in their rates of recovery from and onset of those effects. The ability of drugs such as the agonists d-TC, decamethonium, and mecamylamine to induce functional inactivation may relate to their activities as partial/full agonists, channel blockers, and/or allosteric regulators. Effects of drugs such as pancuronium and alcuronium are likely to reflect simple competitive inhibition of primary ligand binding at functional activation sites.(ABSTRACT TRUNCATED AT 400 WORDS)

Which receptors are bound by Tasimelteon?

Tasimelteon (HETLIOZ™) is an orally bioavailable agonist of the melatonin MT1 and MT2 receptors that has been approved in the US for the treatment of non-24-hour sleep-wake disorder.

[19579175, 25423562, 24228714, 24610704, 25207602, 25422900, 25534555, 20945020]

Tasimelteon, developed by Vanda Pharmaceuticals Inc under license from Bristol-Myers Squibb Co, is a melatonin receptor agonist. Because of the high density of melatonin receptors in the circadian pacemaker, the suprachiasmatic nucleus, melatonergic actions can phase-shift circadian rhythms and promote sleep. Tasimelteon was effective in reducing sleep onset latency (in phase II and III clinical trials) and in resetting the circadian melatonin rhythm (in phase II trials), which indicated its potential suitability as treatment for jet lag, shift work and circadian rhythm sleep disorders. Statistically significant improvements in sleep maintenance have also been observed with the drug. Tasimelteon has been claimed to be useful in the treatment of depression, and preclinical evidence in this respect is to be confirmed in a phase II clinical trial, which was ready to be initiated at the time of publication. It is plausible that the drug may be effective in the treatment of depressive disorders, at least those that are related to circadian dysfunction, and that it may attenuate sleep problems in depressed patients of different subtypes. A general suitability in mitigating other symptoms of major depressive disorder cannot be deduced from the actions of tasimelteon via the melatonin receptors MT1 and MT2. The drug is well tolerated, does not induce impairment of next-day functioning or dependence, and seems to be safe in short-term treatment; however, toxicological data would be required for assessing its long-term safety. Several melatonin receptors agonists (ramelteon, prolonged-release melatonin, agomelatine and tasimelteon) have recently become available for the treatment of insomnia, depression and circadian rhythms sleep-wake disorders. The efficacy and safety profiles of these compounds in the treatment of the indicated disorders are reviewed. Accumulating evidence indicates that sleep-wake disorders and co-existing medical conditions are mutually exacerbating. This understanding has now been incorporated into the new Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5). Therefore, when evaluating the risk/benefit ratio of sleep drugs, it is pertinent to also evaluate their effects on wake and comorbid condition. Beneficial effects of melatonin receptor agonists on comorbid neurological, psychiatric, cardiovascular and metabolic symptomatology beyond sleep regulation are also described. The review underlines the beneficial value of enhancing physiological sleep in comorbid conditions.

Is zyxin a focal adhesion protein?

Yes, zyxin is a focal adhesion protein.

[23267329, 23336069, 23687301, 23742986, 22553491, 22778267, 19853601, 21889443, 23028903, 24039980, 22609203, 24157374, 23254340, 20139076, 20801875, 23454549, 19856213, 21598955, 19173742, 22516607]

Zyxin is a focal adhesion protein that has been implicated in the modulation of cell adhesion and motility, and is hypothesized to be a mechano-sensor in integrin-mediated responses to mechanical force. To test the functional role of zyxin in the mechanotransduction of microvascular smooth muscle cells (VSMC), we utilized atomic force microscopy (AFM) to apply localized pulling forces to VSMC through a fibronectin (FN) focal adhesion induced by a FN-coated bead on cell surface. Application of force with the AFM induced an increase of zyxin accumulation at the site of the FN-bead focal adhesion that accompanied the VSMC contractile response. Whereas, reduction of zyxin expression by using a zyxin-shRNA construct abolished the VSMC contractile response to AFM pulling forces, even though the zyxin-silenced VSMCs displayed increased adhesion to FN in both AFM adhesion assays and cell adhesion assays. The reduced zyxin expression significantly impaired cell spreading and reorganization of the actin cytoskeleton that could indicate a possible underlying reason for the loss of a contractile response to mechanical force. Consistent with these observations, in zyxin-silenced VSMC, we also observed a reduced expression of Rac1, which plays an important role in the actin reorganization in VSMC, but increased thyroid receptor-interacting proteins (TRIP6) and FAK expression, the latter being a major protein that promote cell adhesion. In conclusion, these data support an important enabling role for zyxin in VSMCs ability to mechanically respond to applied force. Cells continuously sense and respond to external mechanical forces through their cytoskeleton. Here we show that only a small subset of actin fibers, those forming the perinuclear actin cap that wraps around the nucleus, form in response to low physiological mechanical stresses in adherent fibroblasts. While conventional basal stress fibers form only past a threshold shear stress of 0.5 dyn/cm(2), actin-cap fibers are formed at shear stresses 50 times lower and orders-of-magnitude faster than biochemical stimulation. This fast differential response is uniquely mediated by focal adhesion protein zyxin at low shear stress and actomyosin fibers of the actin cap. We identify additional roles for lamin A/C of the nuclear lamina and linkers of nucleus to cytoskeleton (LINC) molecules nesprin2giant and nesprin3, which anchor actin cap fibers to the nucleus. These results suggest an interconnected physical pathway for mechanotransduction, from the extracellular milieu to the nucleus. During heart valve development, epithelial-mesenchymal transformation (EMT) is a key process for valve formation. EMT leads to the generation of mesenchymal cells that will eventually become the interstitial cells (fibroblasts) of the mature valve. During EMT, cell architecture and motility change markedly; significant changes are also observed in various signaling pathways. Here we systematically examined the expression, localization, and function of zyxin, a focal adhesion protein, in EMT during atrioventricular (AV) valve morphogenesis. Expression and localization studies showed that zyxin was expressed in the AV canal region during crucial stages of valve development. An in vitro 3D collagen gel culture system was used to determine zyxin function either after siRNA gene knockdown or after overexpression. Our studies revealed that zyxin overexpression inhibited endocardial cell migration and cell differentiation and also led to a decrease in the number of migrating mesenchymal cells. Moreover, correlative cytoskeletal changes were apparent in response to both overexpression and knockdown treatments. Thus, zyxin appears to play a role as a regulator of cell migration and differentiation during EMT in chicken AV valve formation. Tubulobulbar complexes (TBCs) are actin-related double-membrane invaginations formed at intercellular junctions in the seminiferous epithelium of mammalian testis. They occur at basal junction complexes between neighboring Sertoli cells and at apical junctions between Sertoli cells and spermatids. They are proposed to internalize intercellular junctions during the translocation of spermatocytes from basal to adluminal compartments of the seminiferous epithelium, and during sperm release from Sertoli cells. Although TBCs are specific to the seminiferous epithelium, they morphologically resemble podosomes in osteoclasts. Previously, we have reported that a key group of proteins consisting of N-WASp, Arp2/3, cortactin and dynamin that occur at podosomes also is present at TBCs. Here we explore the prediction that zyxin, a focal adhesion protein known to be present at podosomes, also is present at apical TBCs. A rabbit polyclonal anti-zyxin antibody (B71) was used to label fixed fragments and frozen sections of testis. In both fragments and sections, B71 labeled tubular regions of TBCs at apical sites of attachment between Sertoli cells and spermatids, in addition to being localized at actin related intercellular adhesion junctions termed ectoplasmic specializations. Although the function of zyxin at TBCs has yet to be determined, the protein is known to interact with the cytoplasmic domain of integrins at focal adhesions, and integrins are known to be present in TBCs. Synemin is a unique cytoplasmic intermediate filament protein for which there is limited understanding of its exact cellular functions. The single human synemin gene encodes at least two splice variants named alpha-synemin and beta-synemin, with the larger alpha-synemin containing an additional 312 amino acid insert within the C-terminal tail domain. We report herein that, by using the entire tail domain of the smaller beta-synemin as the bait in a yeast two-hybrid screen of a human skeletal muscle cDNA library, the LIM domain protein zyxin was identified as an interaction partner for human synemin. The synemin binding site in human zyxin was subsequently mapped to the C-terminal three tandem LIM-domain repeats, whereas the binding site for zyxin within beta-synemin is within the C-terminal 332 amino acid region (SNbetaTII) at the end of the long tail domain. Transient expression of SNbetaTII within mammalian cells markedly reduced zyxin protein level, blocked localization of zyxin at focal adhesion sites and resulted in decreased cell adhesion and increased motility. Knockdown of synemin expression with siRNAs within mammalian cells resulted in significantly compromised cell adhesion and cell motility. Our results suggest that synemin participates in focal adhesion dynamics and is essential for cell adhesion and migration. Cellular responses to mechanical perturbation are vital to cell physiology. In particular, migrating cells have been shown to sense substrate stiffness and alter cell morphology and speed. Zyxin is a focal adhesion protein that responds to external mechanical forces; however, the mechanisms of zyxin recruitment at force-bearing sites are unknown. Using force-sensing microfabricated substrates, we simultaneously measured traction force and zyxin recruitment at force-bearing sites. GFP-tagged zyxin accumulates at force-bearing sites at the leading edge, but not at the trailing edge, of migrating epithelial cells. Zyxin recruitment at force-bearing sites depends on Rho-kinase and myosin II activation, suggesting that zyxin responds not only to the externally applied force, as previously shown, but also to the internally generated actin-myosin force. Zyxin in turn recruits vasodilator-stimulated phosphoprotein, a regulator of actin assembly, to force-bearing sites. To dissect the domains of zyxin that are essential for this unique force-dependent accumulation, we generated two zyxin truncation mutants: one lacking the LIM domain (ΔLIM) and one containing only the LIM domain with all three LIM motifs (LIM). GFP-tagged ΔLIM does not localize to the force-bearing sites, but GFP-tagged zyxin LIM-domain is sufficient for the recruitment to and dynamics at force-bearing focal adhesions. Furthermore, one or two LIM motifs are not sufficient for force-dependent accumulation, suggesting that all three LIM motifs are required. Therefore, the LIM domain of zyxin recruits zyxin to force-bearing sites at the leading edge of migrating cells. Altered cell motility is considered to be a key factor in determining tumor invasion and metastasis. Epidermal growth factor (EGF) signaling has been implicated in this process by affecting cytoskeletal organization and dynamics in multiple ways. To sort the temporal and spatial regulation of EGF-dependent cytoskeletal re-organization in relation to a cell's motile behavior time-lapse microscopy was performed on EGF-responsive gastric carcinoma-derived MKN1 cells co-expressing different fluorescently labeled cytoskeletal filaments and focal adhesion components in various combinations. The experiments showed that EGF almost instantaneously induces a considerable increase in membrane ruffling and lamellipodial activity that can be inhibited by Cetuximab EGF receptor antibodies and is not elicited in non-responsive gastric carcinoma Hs746T cells. The transient cell extensions are rich in actin but lack microtubules and keratin intermediate filaments. We show that this EGF-induced increase in membrane motility can be measured by a simple image processing routine. Microtubule plus-ends subsequently invade growing cell extensions, which start to accumulate focal complexes at the lamellipodium-lamellum junction. Such paxillin-positive complexes mature into focal adhesions by tyrosine phosphorylation and recruitment of zyxin. These adhesions then serve as nucleation sites for keratin filaments which are used to enlarge the neighboring peripheral keratin network. Focal adhesions are either disassembled or give rise to stable zyxin-rich fibrillar adhesions which disassemble in the presence of EGF to support formation of new focal adhesion sites in the cell periphery. Taken together the results serve as a basis for modeling the early cytoskeletal EGF response as a tightly coordinated and step-wise process which is relevant for the prediction of the effectiveness of anti-EGF receptor-based tumor therapy. Treatment of cultured cells with inhibitors of actomyosin contractility induces rapid deterioration of stress fibers, and disassembly of the associated focal adhesions (FAs). In this study, we show that treatment with the Rho kinase inhibitor Y-27632, which blocks actomyosin contractility, induces disarray in the FA-associated actin bundles, followed by the differential dissociation of eight FA components from the adhesion sites. Live-cell microscopy indicated that the drug triggers rapid dissociation of VASP and zyxin from FAs (τ values of 7-8 min), followed by talin, paxillin and ILK (τ ~16 min), and then by FAK, vinculin and kindlin-2 (τ = 25-28 min). Examination of the molecular kinetics of the various FA constituents, using Fluorescence Recovery After Photobleaching (FRAP), in the absence of or following short-term treatment with the drug, revealed major changes in the kon and koff values of the different proteins tested, which are in close agreement with their differential dissociation rates from the adhesion sites. These findings indicate that mechanical, actomyosin-generated forces differentially regulate the molecular kinetics of individual FA-associated molecules, and thereby modulate FA composition and stability. The ability to sense mechanical forces is vital to cell physiology. Yet, the molecular basis of mechano-signaling remains unclear. Previous studies have shown that zyxin, a focal adhesion protein, is recruited at force-bearing sites on the actin cytoskeleton and, therefore, identifying zyxin as a mechano-sensing protein candidate. Furthermore, zyxin accumulation at force-bearing sites requires the LIM domain located at the C-terminus of zyxin. The zyxin LIM domain consists of three LIM motifs, each containing two zinc-binding sites. Since individual LIM motifs do not accumulate at focal adhesions or force-bearing sites, we hypothesize that multiple zyxin LIM domains increase force sensitivity. Using a miniature force sensor and GFP-tagged LIM variants, we quantified the relationship between single, tandem dimer and trimer LIM protein localization and traction forces. While the presence of extra LIM domains affected VASP recruitment to focal adhesions, force sensitivity was not enhanced over the single LIM domain. Therefore, zyxin force sensitivity is optimal with a single LIM domain, while additional LIM domains fail to enhance force sensitivity. Randomly spread fibroblasts on fibronectin-coated elastomeric membranes respond to cyclic strain by a varying degree of focal adhesion assembly and actin reorganization. We speculated that the individual shape of the cells, which is linked to cytoskeletal structure and pre-stress, might tune these integrin-dependent mechanotransduction events. To this aim, fibronectin circles, squares and rectangles of identical surface area (2000μm(2)) were micro-contact printed onto elastomeric substrates. Fibroblasts plated on these patterns occupied the corresponding shapes. Cyclic 10% equibiaxial strain was applied to patterned cells for 30min, and changes in cytoskeleton and cell-matrix adhesions were quantified after fluorescence staining. After strain, megakaryocytic leukemia-1 protein translocated to the nucleus in most cells, indicating efficient RhoA activation independently of cell shape. However, circular and square cells (with radial symmetry) showed a significantly greater increase in the number of actin stress fibers and vinculin-positive focal adhesions after cyclic strain than rectangular (bipolar) cells of identical size. Conversely, cyclic strain induced larger changes in pY397-FAK positive focal complexes and zyxin relocation from focal adhesions to stress fibers in bipolar compared to symmetric cells. Thus, radially symmetric cells responded to cyclic strain with a larger increase in assembly, whereas bipolar cells reacted with more pronounced reorganization of actin stress fibers and matrix contacts. We conclude that integrin-mediated responses to external mechanical strain are differentially modulated in cells that have the same spreading area but different geometries, and do not only depend on mere cell size. Focal adhesions are large protein complexes organized at the basal surface of cells, which physically connect the extracellular matrix to the cytoskeleton and have long been speculated to mediate cell migration. However, whether clustering of these molecular components into focal adhesions is actually required for these proteins to regulate cell motility is unclear. Here we use quantitative microscopy to characterize descriptors of focal adhesion and cell motility for mouse embryonic fibroblasts and human fibrosarcoma cells, across a wide range of matrix compliance and following genetic manipulations of focal adhesion proteins (vinculin, talin, zyxin, FAK, and paxilin). This analysis reveals a tight, biphasic gaussian relationship between mean size of focal adhesions (not their number, surface density, or shape) and cell speed. The predictive power of this relationship is comprehensively validated by disrupting nonfocal adhesion proteins (α-actinin, F-actin, and myosin II) and subcellular organelles (mitochondria, nuclear DNA, etc.) not known to affect either focal adhesions or cell migration. This study suggests that the mean size of focal adhesions robustly and precisely predicts cell speed independently of focal adhesion surface density and molecular composition. We report the development and application of photoactivatable Green Cherry (G(PA)C), the first genetically encoded "continuously red-photoactivatable green" two-color probe for live cell imaging. G(PA)C is unique in that it enables real-time tracking of selected subpopulations of proteins and organelles in the cell or of cells within tissues and whole organisms, with constant reference to the entire population of the probe. Using G(PA)C-zyxin as proof of utility, we obtained new insights into the dynamic movement of the cytoskeletal protein zyxin. We show that zyxin is continuously and rapidly recruited from the cytosol into established focal adhesions. It can also move rapidly within a given focal adhesion and "hop" between adjacent focal adhesions, emphasizing the dynamic nature of proteins within these structures. The in vivo utility of G(PA)C is exemplified by tracking hemocyte movements using a versatile transgenic Drosophila model engineered to express G(PA)C in tissues and cells of interest under the control of the GAL4-inducible promoter. Focal adhesion proteins link cell surface integrins and intracellular actin stress fibers and therefore play an important role in mechanotransduction and cell motility. When endothelial cells are subjected to cyclic mechanical strain, time-lapse imaging revealed that cells underwent significant morphological changes with their resultant long axes aligned away from the strain direction. To explore how this response is regulated by focal adhesion-associated proteins the expression levels of paxillin, focal adhesion kinase (FAK), and zyxin were knocked down using gene silencing techniques. In addition, rescue of endogenous and two mutant zyxins were used to investigate the specific role of zyxin interactions. Cells with decreased zyxin expression levels and rescue with the mutant lacking zyxin/alpha-actinin binding exhibited lower orientation angles after comparable times of stretching as compared to normal and control cells. However, knockdown of the expression levels of paxillin and FAK and rescue with the mutant lacking zyxin/VASP (vasodilator-stimulated phosphoprotein) binding did not significantly affect the degree of cell orientation. In addition, wound closure speed and cell-substratum adhesive strength were observed to be significantly reduced only for cells with zyxin depletion and the mutation lacking zyxin/alpha-actinin binding. These results suggest that zyxin and its interaction with alpha-actinin are important in the regulation of endothelial cell adhesive strength, motility and orientation response to mechanical stretching. BACKGROUND: SIRT1 is a mammalian homologue of NAD+-dependent deacetylase sirtuin family. It regulates longevity in several model organisms and is involved with cell survival, differentiation, metabolism among other processes in mammalian cells. SIRT1 modulates functions of various key targets via deacetylation. Recent studies have revealed SIRT1 protects neurons from axonal degeneration or neurodegeneration. Further, SIRT1 null mice exhibit growth retardation and developmental defects, suggesting its critical roles in neurons and development. RESULTS: To identify novel binding partners for SIRT1 in the central nervous system, we performed yeast two-hybrid screening on human fetal brain cDNA library and found that zyxin is a possible binding partner. SIRT1 and zyxin transcript were both preferentially expressed in developmental mouse brain. Zyxin accumulates in the nucleus where it is co-localized with SIRT1 after treatment with leptomycin B in COS-7 cells. Furthermore, SIRT1 deacetylates zyxin, suggesting SIRT1 could interact with nuclear-accumulated zyxin and modulate its function through deacetylation. CONCLUSION: Zyxin could be a novel interacting partner of SIRT1. Zyxin is an adaptor protein at focal adhesion plaque, regulating cytoskeletal dynamics and signal transduction to convey signal from the ECM (extracellular matrix) to the nucleus. Our results raise the possibility that SIRT1 regulates signal transmission from ECM to the nucleus by modulating the functions of zyxin via deacetylation.

What is the role of ELMO1 gene in cell migration?

ELMO proteins are also known to regulate actin cytoskeleton reorganization through activation of the small GTPbinding protein Rac via the ELMO-Dock180 complex. In mammalian cells, ELMO1 interacts with Dock180 as a component of the CrkII/Dock180/Rac pathway responsible for phagocytosis and cell migration. We also show that Hck and ELMO1 interact in intact cells and that ELMO1 is heavily tyrosine-phosphorylated in cells that co-express Hck, suggesting that it is a substrate of Hck.The ELMO1/DOCK180 complex then forms a guanine nucleotide exchange factor for Rac1, regulating its activation during cell migration in different biological systems. Rac activation by the ELMO.Dock180 complex at discrete intracellular locations is mediated by the N-terminal 330 amino acids of ELMO1 rather than generalized Rac activation plays a role in cell migration.

[12029088, 23591873, 20466982, 14638695, 24819662, 22503503, 24821968, 11595183, 15952790, 16377631]

RATIONALE: Angiogenesis is regulated by the small GTPase Rac1. The ELMO1/DOCK180 complex forms a guanine nucleotide exchange factor for Rac1, regulating its activation during cell migration in different biological systems. OBJECTIVE: To investigate the function of ELMO1/DOCK180 in vascular development. METHODS AND RESULTS: In situ hybridization studies for elmo1 identified a vascular and neuronal expression in zebrafish. Morpholino-based expression silencing of elmo1 severely impaired the formation of the vasculature, including intersomitic vessels, the dorsal longitudinal anastomotic vessel, the parachordal vessel, and the development of the thoracic duct in tg(fli1:EGFP) embryos. Mechanistically, we identified Netrin-1 and its receptor Unc5B as upstream activators of the ELMO1/DOCK180 complex, regulating its functional interaction and leading to Rac1 activation in endothelial cells and vessel formation in zebrafish. CONCLUSIONS: Our data have identified a novel signaling cascade regulating vasculature formation in zebrafish. Cell migration is essential throughout embryonic and adult life. In numerous cell systems, the small GTPase Rac is required for lamellipodia formation at the leading edge and movement ability. However, the molecular mechanisms leading to Rac activation during migration are still unclear. Recently, a mammalian superfamily of proteins related to the prototype member Dock180 has been identified with homologues in Drosophila and Caenorhabditis elegans. Here, we addressed the role of Dock180 and ELMO1 proteins, which function as a complex to mediate Rac activation, in mammalian cell migration. Using mutants of Dock180 and ELMO1 in a Transwell assay as well as transgenic rescue of a C. elegans mutant lacking CED-5 (Dock180 homologue), we identified specific regions of Dock180 and ELMO1 required for migration in vitro and in a whole animal model. In both systems, the Dock180.ELMO1 complex formation and the ability to activate Rac were required. We also found that ELMO1 regulated multiple Dock180 superfamily members to promote migration. Interestingly, deletion mutants of ELMO1 missing their first 531 or first 330 amino acids that can still bind and cooperate with Dock180 in Rac activation failed to promote migration, which correlated with the inability to localize to lamellipodia. This finding suggests that Rac activation by the ELMO.Dock180 complex at discrete intracellular locations mediated by the N-terminal 330 amino acids of ELMO1 rather than generalized Rac activation plays a role in cell migration. OBJECTIVE: Engulfment and cell motility 1 (Elmo1) has been reported to cooperate with dedicator of cytokinesis 1 (Dock180) and to be linked to the invasive phenotype of cancer cells through activating small G-protein Rac. We aimed to study the role of Elmo1 in the malignant migration of ovarian cancer. METHODS: Engulfment and cell motility 1 expression was evaluated in specimens from 93 patients with serous ovarian cancer (SOC) by immunohistochemical staining. Next, Elmo1-RNAi cells were established by validated small interference RNAs. Cell proliferation and cell motility were observed and compared with Dock180-RNAi cells. To confirm their synergetic contribution to forming focal adhesion and activating Rac1, Rac1-GTP level was measured by GST pull-down assay and immunofluorescence was used to observe focal adhesion formation both in Elmo1-RNAi and Dock180-RNAi cells. RESULTS: Engulfment and cell motility 1 was mainly overexpressed in high-grade SOC tissues. Western blot analysis demonstrated that both Elmo1 and Dock180 expressions were hampered in Elmo1-RNAi cells. Compared with the negative control, decreased colony formation and cell invasion were observed in Elmo1-RNAi cells and Dock180-RNAi cells. Consistently, both exhibited reduced Rac1-GTP level and inhibited focal adhesion formation. CONCLUSIONS: Engulfment and cell motility 1 presents with synergetic action in helping Dock180 to activate Rac1 and promote cell motility, and thus promote untoward expansion and aggressiveness of SOC. Apoptotic cell death is essential for development and tissue homeostasis. Failure to clear apoptotic cells can ultimately cause inflammation and autoimmunity. Apoptosis has primarily been studied by staining of fixed tissue sections, and a clear understanding of the behavior of apoptotic cells in living tissue has been elusive. Here, we use a newly developed technique to track apoptotic cells in real time as they emerge and are cleared from the zebrafish brain. We find that apoptotic cells are remarkably motile, frequently migrating several cell diameters to the periphery of living tissues. F-actin remodeling occurs in surrounding cells, but also within the apoptotic cells themselves, suggesting a cell-autonomous component of motility. During the first 2 days of development, engulfment is rare, and most apoptotic cells lyse at the brain periphery. By 3 days postfertilization, most cell corpses are rapidly engulfed by macrophages. This engulfment requires the guanine nucleotide exchange factor elmo1. In elmo1-deficient macrophages, engulfment is rare and may occur through macropinocytosis rather than directed engulfment. These findings suggest that clearance of apoptotic cells in living vertebrates is accomplished by the combined actions of apoptotic cell migration and elmo1-dependent macrophage engulfment. Elmo1 and Elmo2 are highly homologous cytoplasmic adaptor proteins that interact with Dock family guanine nucleotide exchange factors to promote activation of the small GTPase Rac. In T lymphocytes, Dock2 is essential for CCR7- and CXCR4-dependent Rac activation and chemotaxis, but the role of Elmo proteins in regulating Dock2 function in primary T cells is not known. In this article, we show that endogenous Elmo1, but not Elmo2, interacts constitutively with Dock2 in mouse and human primary T cells. CD4(+) T cells from Elmo1(-/-) mice were profoundly impaired in polarization, Rac activation, and chemotaxis in response to CCR7 and CXCR4 stimulation. Transfection of full-length Elmo1, but not Elmo2 or a Dock2-binding mutant of Elmo1, rescued defective migration of Elmo1(-/-) T cells. Interestingly, Dock2 protein levels were reduced by 4-fold in Elmo1(-/-) lymphocytes despite normal levels of Dock2 mRNA. Dock2 polyubiquitination was increased in Elmo1(-/-) T cells, and treatment with proteasome inhibitors partially restored Dock2 levels in Elmo1(-/-) T cells. Finally, we show that Dock2 is directly ubiquitinated in CD4(+) T cells and that Elmo1 expression in heterologous cells inhibits ubiquitination of Dock2. Taken together, these findings reveal a previously unknown, nonredundant role for Elmo1 in controlling Dock2 levels and Dock2-dependent T cell migration in primary lymphocytes. Inhibition of Dock2 has therapeutic potential as a means to control recruitment of pathogenic lymphocytes in diseased tissues. This work provides valuable insights into the molecular regulation of Dock2 by Elmo1 that can be used to design improved inhibitors that target the Elmo-Dock-Rac signaling complex. The C. elegans genes ced-2, ced-5, and ced-10, and their mammalian homologs crkII, dock180, and rac1, mediate cytoskeletal rearrangements during phagocytosis of apoptotic cells and cell motility. Here, we describe an additional member of this signaling pathway, ced-12, and its mammalian homologs, elmo1 and elmo2. In C. elegans, CED-12 is required for engulfment of dying cells and for cell migrations. In mammalian cells, ELMO1 functionally cooperates with CrkII and Dock180 to promote phagocytosis and cell shape changes. CED-12/ELMO-1 binds directly to CED-5/Dock180; this evolutionarily conserved complex stimulates a Rac-GEF, leading to Rac1 activation and cytoskeletal rearrangements. These studies identify CED-12/ELMO as an upstream regulator of Rac1 that affects engulfment and cell migration from C. elegans to mammals.

What is the biological role of K-48 linked protein ubiquitination?

The proteasome, which identifies and destroys unwanted proteins rapidly, plays a vital role in maintaining cellular protein homeostasis. Proteins that are destined for proteasome-mediated degradation are usually tagged with a chain of ubiquitin linked via lysine (K) 48 that targets them to the proteolytic machinery. K(48)-linked polyubiquitinated proteins are degraded by the proteasomes to elevate cellular levels of amino acids needed for intracellular proliferation. NF-κB and ubiquitylation initially became linked when it was recognised that lysine (K)48-linked ubiquitin chains are involved in the processing of NF-κB precursors and the degradation of inhibitor of kappa B (IκB) proteins.

[19887490, 15728425, 22389394, 19432818, 20696248, 24126522]

Proteins tagged with lysine (Lys, K) 48 polyubiquitins chains are destined for degradation by the 26S proteasomal system. Impairment of the ubiquitin proteasome system (UPS) function culminates in the accumulation of polyubiquitinated proteins in many neurodegenerative conditions including Parkinson's disease (PD). Nevertheless, the cellular mechanisms underlying cell death induced by an impaired UPS are still not clear. Intriguingly, recent studies indicate that several proteins associated with familial PD are capable of promoting the assembly of Lys-63 polyubiquitin chains. Therefore, the objective of this study was to examine the role of K48 and K63 ubiquitination in mitochondria-mediated apoptosis in in vitro models of dopaminergic degeneration. Exposure of the widely used proteasome inhibitor MG-132 to dopaminergic neuronal cell line (N27) induced a rapid accumulation of polyubiquitinated proteins in the mitochondria. This appears to result in the preferential association of ubiquitin conjugates in the outer membrane and polyubiquitination of outer membrane proteins. Interestingly, the ubiquitin(K48R) mutant effectively rescued cells from MG-132-induced mitochondrial apoptosis without altering the antioxidant status of cells; whereas the ubiquitin(K63R) mutant augmented the proapoptotic effect of MG-132. Herein, we report a novel conclusion that polyubiquitinated proteins, otherwise subjected to proteasomal degradation, preferentially accumulate in the mitochondria during proteolytic stress; and that polyubiquitination of Lys-48 and Lys-63 are key determinants of mitochondria-mediated cell death during proteasomal dysfunction. Together, these findings yield novel insights into a crosstalk between the UPS and mitochondria in dopaminergic neuronal cells. Upon entry of Legionella pneumophila into amoebas and macrophages, host-mediated farnesylation of the AnkB effector enables its anchoring to the Legionella-containing vacuole (LCV) membrane. On the LCV, AnkB triggers docking of K(48)-linked polyubiquitinated proteins that are degraded by the host proteasomes to elevate cellular levels of amino acids needed for intracellular proliferation. Interference with AnkB function triggers L. pneumophila to exhibit a starvation response and differentiate into the nonreplicative phase in response to the basal levels of cellular amino acids that are not sufficient to power intracellular proliferation of L. pneumophila. Therefore, we have determined whether the biological function of AnkB is temporally and spatially triggered upon bacterial attachment to the host cell to circumvent a counterproductive bacterial differentiation into the nonreplicative phase upon bacterial entry. Here, we show that upon attachment of L. pneumophila to human monocyte-derived macrophages (hMDMs), the host farnesylation and ubiquitination machineries are recruited by the Dot/Icm system to the plasma membrane exclusively beneath sites of bacterial attachment. Transcription and injection of ankB is triggered by attached extracellular bacteria followed by rapid farnesylation and anchoring of AnkB to the cytosolic side of the plasma membrane beneath bacterial attachment, where K(48)-linked polyubiquitinated proteins are assembled and degraded by the proteasomes, leading to a rapid rise in the cellular levels of amino acids. Our data represent a novel strategy by an intracellular pathogen that triggers rapid nutritional remodeling of the host cell upon attachment to the plasma membrane, and as a result, a gratuitous surplus of cellular amino acids is generated to support proliferation of the incoming pathogen.

Could DNA (cytosine-5-)-methyltransferases serve as tumour markers?

Yes. It has been demonstrated in a number of experimental studies that DNA (Cytosine-5-)-methyltransferases (DNMT1, DNMT3A and DNMT3B) are deregulated in several types of cancer (invasive cervical cancer, colon cancer, esophageal squamous cell carcinoma (ESCC), gastric cancer, embryonal carcinoma, cervical cancer, adenoma, adenoid cystic carcinoma, salivary gland neoplasms). Moreover, three single nucleotide polymorphisms (SNPs) of the DNMT3B promoter region have been reported to be stratification markers that can predict an individual's susceptibility to cancers. Therefore, DNA (Cytosine-5-)-methyltransferases can serve as tumour markers.

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We evaluated the significance of aberrant DNA methyltransferase 1 (DNMT1) protein expression during gastric carcinogenesis. The protein expression of DNMT1, Muc2, human gastric mucin, E-cadherin, and proliferating cell nuclear antigen was examined immunohistochemically in gastric cancers and corresponding noncancerous mucosae from 134 patients. The DNA methylation status of the CpG islands of the p16, human MutL homologue 1 (hMLH1), E-cadherin, and thrombospondin-1 (THBS-1) genes and the methylated in tumor (MINT)-1, -2, -12, and -31 clones was examined by methylation-specific polymerase chain reaction and combined bisulfite restriction enzyme analysis. Epstein-Barr virus (EBV) infection was detected by in situ hybridization. Nuclear immunoreactivity for DNMT1 was not detected in any of the noncancerous epithelia, except in proliferative zones (positive internal control), but was found in 97 (72%) of the gastric cancers. DNMT1 overexpression correlated significantly with poorer tumor differentiation (P < 0.001), but not with the phenotype (gastric type versus intestinal type) of the cancer cells. It also correlated significantly with DNA hypermethylation of the CpG islands of the hMLH1 (P = 0.024) and THBS-1 genes (P = 0.043), and with the CpG island methylator phenotype in the gastric cancers (P = 0.007). Reduced E-cadherin expression correlated significantly with poorer tumor differentiation (P = 0.002), DNA hypermethylation of the E-cadherin gene (P < 0.001) and DNMT1 overexpression (P = 0.014). DNMT1 overexpression was also associated with EBV infection (a potential etiological factor in gastric carcinogenesis) but not with the proliferative activity of the cancer cells as indicated by the proliferating cell nuclear antigen-labeling index. These results suggest that DNMT1 overexpression may not be just a secondary effect of increased cancer cell proliferative activity, but may be associated with EBV infection and other etiological factors during gastric carcinogenesis. Furthermore, DNMT1 may play a significant role in the development of poorly differentiated gastric cancers by inducing frequent DNA hypermethylation of multiple CpG islands. Aberrant DNA methylation has been shown to play an important role during multistage carcinogenesis in various human organs. The aim of the present study was to evaluate the significance of DNA methyltransferase 1 (DNMT1) protein expression during pancreatic carcinogenesis. Immunohistochemical analysis of DNMT1 in 48 peripheral pancreatic duct epithelia showing no remarkable histological findings without an inflammatory background (DE), 54 peripheral pancreatic duct epithelia with an inflammatory background (DEI), 188 pancreatic intraepithelial neoplasias (PanIN), and 220 areas of invasive ductal carcinoma from surgical specimens resected from 100 patients, was carried out. The average incidence of DNMT1 immunoreactivity increased progressively from DE to DEI (P = 0.003), from DE and DEI to PanIN (P < 0.0001), among PanIN with different grades of dysplasia (from PanIN I to PanIN II, P = 0.0012), from PanIN to invasive ductal carcinomas (P < 0.0001) and among invasive ductal carcinomas with different grades of histological differentiation (from well or moderately to poorly differentiated adenocarcinomas, P < 0.0001). High-level DNMT1 protein expression in invasive ductal carcinomas was correlated significantly with an advanced t category (P = 0.0224) and an advanced stage (P = 0.0294). Moreover, patients with invasive ductal carcinomas showing high-level DNMT1 protein expression had a poorer outcome (P = 0.0469). These data suggest that increased DNMT1 protein expression participates in multistage pancreatic carcinogenesis from the precancerous stage to malignant progression of ductal carcinomas and may be a biological predictor of poor prognosis. Vorinostat (suberoylanilide hydroxamic acid), a class of histone deacetylase inhibitors, represents an emerging class of anticancer agents currently progressing in clinical trials. It causes cell growth inhibition, differentiation, and apoptosis of many tumor types in vitro and in vivo. Recently, it was reported that hTERT is one of the targets for cancer therapy in cancer cells. Telomerase repeat amplification protocol assay was used to analyze the expression of hTERT after vorinostat treatment in the A549 lung cancer cells. Vorinostat inhibited telomerase activity by reducing the expression of human telomerase reverse transcriptase (hTERT) in A549 human lung cancer cells. The epigenetic regulation mechanism is responsible for the repression of hTERT by vorinostat, analyzed through the methylation-specific PCR and bisulfite sequencing of the hTERT promoter. Vorinostat induced the demethylation of site-specific CpGs on the promoter region of hTERT, which was caused by the down-regulation of DNA methyltransferases. DNA methyltransferases (DNMT1 and DNMT3b) were also decreased in vorinostat-treated A549 cancer cells. Furthermore, chromatin immunoprecipitation analysis of the hTERT promoter revealed that vorinostat decreased the level of inactive chromatin markers dimethyl-H3K9, and the declined binding of DNMT1 and DNMT3b were associated. The novel insights showed that vorinostat down-regulated telomerase via epigenetic alteration in lung cancer to vorinostat-mediated cancer-specific therapies. Candidate gene-based studies have identified a handful of aberrant CpG DNA methylation events in prostate cancer. However, DNA methylation profiles have not been compared on a large scale between prostate tumor and normal prostate, and the mechanisms behind these alterations are unknown. In this study, we quantitatively profiled 95 primary prostate tumors and 86 benign adjacent prostate tissue samples for their DNA methylation levels at 26,333 CpGs representing 14,104 gene promoters by using the Illumina HumanMethylation27 platform. A 2-class Significance Analysis of this data set revealed 5912 CpG sites with increased DNA methylation and 2151 CpG sites with decreased DNA methylation in tumors (FDR < 0.8%). Prediction Analysis of this data set identified 87 CpGs that are the most predictive diagnostic methylation biomarkers of prostate cancer. By integrating available clinical follow-up data, we also identified 69 prognostic DNA methylation alterations that correlate with biochemical recurrence of the tumor. To identify the mechanisms responsible for these genome-wide DNA methylation alterations, we measured the gene expression levels of several DNA methyltransferases (DNMTs) and their interacting proteins by TaqMan qPCR and observed increased expression of DNMT3A2, DNMT3B, and EZH2 in tumors. Subsequent transient transfection assays in cultured primary prostate cells revealed that DNMT3B1 and DNMT3B2 overexpression resulted in increased methylation of a substantial subset of CpG sites that showed tumor-specific increased methylation. Epigenetic modifications are a driving force in carcinogenesis. However, their role in cancer metastasis remains poorly understood. The present study investigated the role of DNA methylation in the cervical cancer metastasis. Here, we report evidence of the overexpression of DNA methyltransferases 3B (DNMT3B) in invasive cervical cancer and of the inhibition of metastasis by DNMT3B interference. Using methyl-DNA immunoprecipitation coupled with microarray analysis, we found that the protein tyrosine phosphatase receptor type R (PTPRR) was silenced through DNMT3B-mediated methylation in the cervical cancer. PTPRR inhibited p44/42 MAPK signaling, the expression of the transcription factor AP1, human papillomavirus (HPV) oncogenes E6/E7 and DNMTs. The methylation status of PTPRR increased in cervical scrapings (n=358) in accordance with disease severity, especially in invasive cancer. Methylation of the PTPRR promoter has an important role in the metastasis and may be a biomarker of invasive cervical cancer. Epigenetic events play a prominent role during cancer development. This is evident from the fact that almost all cancer types show aberrant DNA methylation. These abnormal DNA methylation levels are not restricted to just a few genes but affect the whole genome. Previous studies have shown genome-wide DNA hypomethylation and gene-specific hypermethylation to be a hallmark of most cancers. Molecules like DNA methyltransferase act as effectors of epigenetic reprogramming. In the present study we have examined the possibility that the reprogramming genes themselves undergo epigenetic modifications reflecting their changed transcriptional status during cancer development. Comparison of DNA methylation status between the normal and cervical cancer samples was carried out at the promoters of a few reprogramming molecules. Our study revealed statistically significant DNA methylation differences within the promoter of DNMT3L. A regulator of de novo DNA methyltransferases DNMT3A and DNMT3B, DNMT3L promoter was found to have lost DNA methylation to varying levels in 14 out of 15 cancer cervix samples analysed. The present study highlights the importance of DNA methylation profile at DNMT3L promoter not only as a promising biomarker for cervical cancer, which is the second most common cancer among women worldwide, but also provides insight into the possible role of DNMT3L in cancer development. 5-Azactydine inhibits cell growth by direct cytotoxic action as well as by inhibition of DNA methyl transferase enzyme. Inhibitors of DNMT have been reported to potentiate the therapeutic activity of cisplatin in vitro. Dose dependent bone marrow toxicity, neurotoxicity and nephrotoxicity are the major side effects of cisplatin, limiting its use as an effective chemotherapeutic agent. The present study was aimed to reduce the nephrotoxic potential of cisplatin without compensating its potency. To best of our knowledge, this is the first report which shows that the combination of 5-azacytidine with cisplatin leads to remarkable reduction in nephrotoxicity, by involving inhibition of cisplatin induced metallothionein expression. 5-Azacytidine treatment with cisplatin leads to maximum reduction in tumor size in DMH induced colon cancer and tumor volume in DMBA induced breast cancer bearing SD rats. This combination regimen prevents phosphorylation and acetylation of histone H3 which may be involved in inhibition of aberrant gene expression in colon tumors. Further, 5-azacytidine potentiated cisplatin induced antitumor activity by involving decreased expression of pAKT, DNMT1 and an increased expression of p38 in colon tumors. Thus, combination of 5-azactydine with cisplatin attenuates the cisplatin induced nephrotoxicity and potentiates the anti-cancer activity which can have profound clinical implications. DNA methyltransferase Dnmt1 ensures clonal transmission of lineage-specific DNA methylation patterns in a mammalian genome during replication. Dnmt1 is targeted to replication foci, interacts with PCNA, and favors methylating the hemimethylated form of CpG sites. To understand the underlying mechanism of its maintenance function, we purified recombinant forms of full-length Dnmt1, a truncated form of Dnmt1-(291-1620) lacking the binding sites for PCNA and DNA and examined their processivity using a series of long unmethylated and hemimethylated DNA substrates. Direct analysis of methylation patterns using bisulfite-sequencing and hairpin-PCR techniques demonstrated that full-length Dnmt1 methylates hemimethylated DNA with high processivity and a fidelity of over 95%, but unmethylated DNA with much less processivity. The truncated form of Dnmt1 showed identical properties to full-length Dnmt1 indicating that the N-terminal 290-amino acid residue region of Dnmt1 is not required for preferential activity toward hemimethylated sites or for processivity of the enzyme. Remarkably, our analyses also revealed that Dnmt1 methylates hemimethylated CpG sites on one strand of double-stranded DNA during a single processive run. Our findings suggest that these inherent enzymatic properties of Dnmt1 play an essential role in the faithful and efficient maintenance of methylation patterns in the mammalian genome. PURPOSE: Testicular germ cell tumors (TGCT) have a unique epigenetic profile distinct from that of other types of cancer. Elucidation of these properties has a potential to identify novel markers for TGCTs. EXPERIMENTAL DESIGN: We conducted comprehensive analysis of DNA methyltransferase (DNMT) gene expression in TGCTs. Based on the expression profiles of DNMT genes in TGCTs, we generated a rabbit polyclonal anti-human DNMT3L antibody. We then studied the role of DNMT3L in TGCTs by the treatment of two embryonal carcinoma (EC) cell lines with a small interfering RNA system. Finally, we evaluated the immunohistochemical detection of DNMT3L in TGCT tissues. We also compared the patterns of DNMT3L immunohistochemistry with those of CD30 and SOX2. RESULTS: Among the DNMT genes, we found that mRNA for DNMT3L was specifically expressed in TGCTs, but neither in normal testicular tissues nor in cancer cells of somatic tissue origin. DNMT3L protein was strongly expressed in two EC cell lines, but not in the cell lines of somatic tissue origin. Transfection of small interfering RNA for DNMT3L significantly reduced DNMT3L expression and resulted in growth suppression and apoptosis in EC cells. Immunohistochemical analysis showed that DNMT3L protein was present only in EC cells, but not in the other types of TGCT components and cancer cells of somatic tissue origin. DNMT3L staining was more prominent and specific than CD30 or SOX2 staining for detecting EC cells. CONCLUSION: DNMT3L is a novel marker and is essential for the growth of human embryonal carcinoma. BACKGROUND: A hallmark of cancer cells is hypermethylation of CpG islands (CGIs), which probably arises from upregulation of one or more DNA methyltransferases. The purpose of this study was to identify the targets of DNMT3B, an essential DNA methyltransferase in mammals, in colon cancer. METHODOLOGY/PRINCIPAL FINDINGS: Chromatin immunoprecipitation with DNMT3B specific antibody followed by CGI microarray identified genes with or without CGIs, repeat elements and genomic contigs in RKO cells. ChIP-Chop analysis showed that the majority of the target genes including P16, DCC, DISC1, SLIT1, CAVEOLIN1, GNA11, TBX5, TBX18, HOXB13 and some histone variants, that harbor CGI in their promoters, were methylated in multiple colon cancer cell lines but not in normal colon epithelial cells. Further, these genes were reactivated in RKO cells after treatment with 5-aza-2'-deoxycytidine, a DNA hypomethylating agent. COBRA showed that the CGIs encompassing the promoter and/or coding region of DCC, TBX5, TBX18, SLIT1 were methylated in primary colorectal tumors but not in matching normal colon tissues whereas GNA11 was methylated in both. MassARRAY analysis demonstrated that the CGI located approximately 4.5 kb upstream of HOXB13 +1 site was tumor-specifically hypermethylated in primary colorectal cancers and cancer cell lines. HOXB13 upstream CGI was partially hypomethylated in DNMT1(-/-) HCT cells but was almost methylation free in cells lacking both DNMT1 and DNMT3B. Analysis of tumor suppressor properties of two aberrantly methylated transcription factors, HOXB13 and TBX18, revealed that both inhibited growth and clonogenic survival of colon cancer cells in vitro, but only HOXB13 abolished tumor growth in nude mice. CONCLUSIONS/SIGNIFICANCE: This is the first report that identifies several important tumor suppressors and transcription factors as direct DNMT3B targets in colon cancer and as potential biomarkers for this cancer. Further, this study shows that methylation at an upstream CGI of HOXB13 is unique to colon cancer. Overexpression of the DNA methyltransferase 3B (DNMT3B) gene and its effect on carcinogenesis has been demonstrated for various types of cancer. Recently, three single nucleotide polymorphisms (SNPs) of the DNMT3B promoter region, C46359T (-149C>T), -283T>C, and -579G>T have also been reported to be stratification markers that can predict an individual's susceptibility to cancers. In this study, we analyzed expression of DNMT3B in nasopharyngeal carcinoma (NPC) specimens and did not find elevated levels of DNMT3B in tumors using cDNA microarray analysis and RT-PCR. Meanwhile, 259 NPC patients and 250 controls were genotyped for the above three SNPs using a MALDI-TOF based mini-sequencing method. For C46359T (-149C>T), only the T/T genotype was found to be present in both patient and control groups (100% frequency). The frequency of the genotypes, -283CC, -283CT and -283TT, amongst NPC patients versus controls was, respectively, 86.1% versus 84.0%, 13.5% versus 15.6%, and 0.4% versus 0.4% (P=0.589). The allele frequency, -597TT, -597GT and -597GG, for patients versus controls was, respectively, 87.3% versus 84.8%, 12.0% versus 15.2%, and 0.8% versus 0 (P=0.501). The distribution of SNPs among cancer patients either featuring or not featuring cervical metastasis also did not reveal any significant difference. In conclusion, our data indicate that neither overexpression of DNMT3B nor the presence of three DNMT3B SNPs are associated with NPC, which suggests that DNMT3B might not play a role in hypermethylation of many tumor suppressor genes during carcinogenesis of NPC. Aberrant DNA methylation has been shown to play important roles during multistage carcinogenesis in various human organs. The aim of this study was to evaluate the significance of DNA methyltransferase 1 (DNMT1) protein expression during cervical carcinogenesis. We carried out an immunohistochemical examination for DNMT1 in 34 samples of histologically normal squamous epithelium, 36 samples of low-grade cervical intraepithelial neoplasia (CIN), 61 samples of higher-grade CIN and 30 samples of squamous cell carcinoma of the uterine cervix. The DNMT1 protein expression score, reflecting the intensity and incidence of DNMT1 nuclear immunoreactivity, was increased even in low-grade CIN (P<0.0001) in comparison with histologically normal squamous epithelium and was further increased in higher-grade CIN (P<0.0001 compared to low-grade CIN). The DNMT1 protein expression score remained at a plateau in microinvasive carcinoma (Stage IA, P=0.0690 compared to higher-grade CIN) and then decreased with cancer invasion (Stage IB or more, P=0.0176 compared to Stage IA), whereas the proliferating cell nuclear antigen (PCNA) labeling index did not decrease with cancer invasion (P=0.8259 between Stage IA and Stage IB or more). Thus, the DNMT1 protein expression score and the PCNA labeling index were not mutually correlated in squamous cell carcinoma of the uterine cervix (P=0.2304). These data suggest that progressively increasing expression of DNMT1 protein is not entirely a secondary result of increased cell proliferative activity, but is associated with an early step of multistage cervical carcinogenesis. DNA methylation patterns in genome are maintained during replication by a DNA methyltransferase Dnmt1. Mouse Dnmt1 is a 180 kDa protein comprising the N-terminal regulatory domain, which covers 2/3 of the molecule, and the rest C-terminal catalytic domain. In the present study, we demonstrated that the limited digestion of full-length Dnmt1 with different proteases produced a common N-terminal fragment, which migrated along with Dnmt1 (1-248) in SDS-polyacrylamide gel electrophoresis. Digestion of the N-terminal domains larger than Dnmt1 (1-248) with chymotrypsin again produced the fragment identical to the size of Dnmt1 (1-248). These results indicate that the N-terminal domain of 1-248 forms an independent domain. This N-terminal domain showed DNA binding activity, and the responsible sequence was narrowed to the 79 amino acid residues involving the proliferating cell nuclear antigen (PCNA) binding motif. The DNA binding activity did not distinguish between DNA methylated and non-methylated states, but preferred to bind to the minor groove of AT-rich sequence. The DNA binding activity of the N-terminal domain competed with the PCNA binding. We propose that DNA binding activity of the N-terminal domain contributes to the localization of Dnmt1 to AT-rich sequence such as Line 1, satellite, and the promoter of tissue-specific silent genes. Genomic hypomethylation is a consistent finding in both human and animal tumors and mounting experimental evidence suggests a key role for epigenetic events in tumorigenesis. Furthermore, it has been suggested that early changes in DNA methylation and histone modifications may serve as sensitive predictive markers in animal testing for carcinogenic potency of environmental agents. Alterations in metabolism of methyl donors, disturbances in activity and/or expression of DNA methyltransferases, and presence of DNA single-strand breaks could contribute to the loss of cytosine methylation during carcinogenesis; however, the precise mechanisms of genomic hypomethylation induced by chemical carcinogens remain largely unknown. This study examined the mechanism of DNA hypomethylation during hepatocarcinogenesis induced by peroxisome proliferators WY-14,643 (4-chloro-6-(2,3-xylidino)-pyrimidynylthioacetic acid) and DEHP (di-(2-ethylhexyl)phthalate), agents acting through non-genotoxic mode of action. In the liver of male Fisher 344 rats exposed to WY-14,643 (0.1% (w/w), 5 months), the level of genomic hypomethylation increased by approximately 2-fold, as compared to age-matched controls, while in the DEHP group (1.2% (w/w), 5 months) DNA methylation did not change. Global DNA hypomethylation in livers from WY-14,643 group was accompanied by the accumulation of DNA single-strand breaks, increased cell proliferation, and diminished expression of DNA methyltransferase 1, while the metabolism of methyl donors was not affected. In contrast, none of these parameters changed significantly in rats fed DEHP. Since WY-14,643 is much more potent carcinogen than DEHP, we conclude that the extent of loss of DNA methylation may be related to the carcinogenic potential of the chemical agent, and that accumulation of DNA single-strand breaks coupled to the increase in cell proliferation and altered DNA methyltransferase expression may explain genomic hypomethylation during peroxisome proliferator-induced carcinogenesis. DNA methyltransferase 1 (DNMT1) is the primary enzyme that maintains DNA methylation. We describe a previously unknown mode of regulation of DNMT1 protein stability through the coordinated action of an array of DNMT1-associated proteins. DNMT1 was destabilized by acetylation by the acetyltransferase Tip60, which triggered ubiquitination by the E3 ligase UHRF1, thereby targeting DNMT1 for proteasomal degradation. In contrast, DNMT1 was stabilized by histone deacetylase 1 (HDAC1) and the deubiquitinase HAUSP (herpes virus-associated ubiquitin-specific protease). Analysis of the abundance of DNMT1 and Tip60, as well as the association between HAUSP and DNMT1, suggested that during the cell cycle the initiation of DNMT1 degradation was coordinated with the end of DNA replication and the need for DNMT activity. In human colon cancers, the abundance of DNMT1 correlated with that of HAUSP. HAUSP knockdown rendered colon cancer cells more sensitive to killing by HDAC inhibitors both in tissue culture and in tumor xenograft models. Thus, these studies provide a mechanism-based rationale for the development of HDAC and HAUSP inhibitors for combined use in cancer therapy. The prevalence, the prognostic effect, and interaction with other molecular markers of DNMT3A mutations was studied in 415 patients with acute myeloid leukemia (AML) younger than 60 years. We show mutations in DNMT3A in 96 of 415 patients with newly diagnosed AML (23.1%). Univariate Cox regression analysis showed that patients with DNMT3A(mutant) AML show significantly worse overall survival (OS; P = .022; hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.04-1.81), and relapse-free survival (RFS; P = .005; HR, 1.52; 95% CI, 1.13-2.05) than DNMT3A(wild-type) AMLs. In a multivariable analysis, DNMT3A mutations express independent unfavorable prognostic value for OS (P = .003; HR, 1.82; 95% CI, 1.2-2.7) and RFS (P < .001; HR, 2.2; 95% CI, 1.4-3.3). In a composite genotypic subset of cytogenetic intermediate-risk AML without FLT3-ITD and NPM1 mutations, this association is particularly evident (OS: P = .013; HR, 2.09; 95% CI, 1.16-3.77; RFS: P = .001; HR, 2.65; 95% CI, 1.48-4.89). The effect of DNMT3A mutations in human AML remains elusive, because DNMT3A(mutant) AMLs did not express a methylation or gene expression signature that discriminates them from patients with DNMT3A(wild-type) AML. We conclude that DNMT3A mutation status is an important factor to consider for risk stratification of patients with AML. OBJECTIVE: Salivary gland neoplasms pathogenesis has not been well established. DNA methylation occurs when methyl groups are added to cytosine nucleotides in specific areas of the gene by the enzyme DNA methyltransferase (DNMT). This chemical modification can alter gene expression without altering DNA sequence. While DNMT3a is mostly involved in de novo methylation, DNMT1 acts as a maintenance methyltransferase. We aimed to investigate the immunoexpression of DNMT3a and DNMT1 in minor salivary gland neoplasms, comparing it with normal tissue. MATERIAL: Forty-four formalin-fixed and paraffin-embedded samples of pleomorphic adenoma, adenoid cystic carcinoma, mucoepidermoid carcinoma and polymorphous low-grade adenocarcinoma were included in the study. The DNMT1 and DNMT3a proteins were identified by using a highly sensitive polymer-based system. RESULTS: Positive nuclear and cytoplasmic labeling for DNMT1 was observed in all samples, including the controls. Positive nuclear labeling for DNMT3a was found only in few neoplasms: 1 pleomorphic adenoma (9.0%), 2 adenoid cystic carcinoma (16.6%) and 1 mucoepidermoid (9.0%) cases. CONCLUSION: Our results were not able to demonstrate a clear correlation between DNMT1 and DNMT3a immunoexpression and salivary gland neoplasms development. We assessed expression of the BRCA1, CTCF and DNMT3b methyltransferase genes along with BRCA1 promoter methylation to better define the epigenetic events involved in BRCA1 inactivation in sporadic breast cancer. These gene expression patterns were determined in 54 sporadic breast tumours by immunohistochemistry and the methylation status of the BRCA1 promoter was evaluated using methylation-specific PCR. We observed significant DNMT3b expression in 80% of the tumours and that 43% of tumours exhibited novel cytoplasmic CTCF expression. Pairwise analyses of gene expression patterns showed that 28/32 tumours lacked BRCA1 expression and also exhibited cytoplasmic CTCF staining, while 24/32 of these tumours also overexpressed DNMT3b. Furthermore, 86% of the BRCA1 low-expressing tumours were methylated at the BRCA1 promoter and a subset of these tumours displayed both cytoplasmic CTCF and increased DNMT3b expression. Thus, tumour subsets exist that display concurrent decreased BRCA1 expression, BRCA1 promoter methylation, cytoplasmic CTCF expression and with DNMT3b over-expression. We suggest that these altered CTCF and DNMT3b expression patterns represent (a) critical events responsible for the epigenetic inactivation of BRCA1 and (b) a diagnostic signature for epigenetic inactivation of other tumour suppressor genes in sporadic breast tumours. This study was designed to determine the significance of DNA methyltransferases (DNMTs) in DNA hypermethylation in esophageal squamous cell carcinoma (ESCC) and to identify DNA methylation markers in serum for the early diagnosis of ESCC. A promoter methylation profile of 12 tumor-related genes was assessed using methylation-specific PCR in ESCC and paired non-tumor tissue samples from 47 patients. Expression levels of DNMTs were examined by real-time reverse transcription-PCR and immunohistochemistry. Using MethyLight, the methylation status of 5 genes was analyzed in serum samples from 45 patients and 15 healthy individuals. A total of 46 (97.9%) of 47 ESCC samples showed methylation in at least one of the examined genes, and methylation was most frequent for RAR-β (46.8%), DAPK (46.8%), p16 (44.7%), and CDH1 (42.6%). Methylation of RASSF1A was significantly correlated with the poorly differentiated tumors and the early pathologic tumor classification (P=0.035 and P=0.046, respectively). Tumoral DNMT3b mRNA up-regulation was significantly correlated with hypermethylation of multiple tumor-related genes (P=0.021). In addition, hypermethylation of cell-free serum DNA was common in ESCC patients, and diagnostic accuracy was increased when methylation of multiple genes (RAR-β, DAPK, CDH1, p16 and RASSF1A) were analyzed in combination (ROC AUC 0.911, 82.2% sensitivity and 100% specificity). The present study suggests that hypermethylation of multiple tumor-related genes may be involved in the pathogenesis of ESCC and mediated by the increase of DNMT3b expression. A cluster of multiple methylated genes in serum DNA has the potential as a novel biomarker for ESCC diagnosis. DNA (cytosine-5-)-methyltransferase 1 (DNMT1) plays an important role in the maintenance of DNA methylation patterns via complicated networks including signaling pathways and transcriptional factors, relating to cell differentiation or carcinogenesis. In the present study, we designed an antisense oligodeoxynucleotide of DNMT1 (AS/MT: 5'-CGGTAC GCGCCGGCATCT-3') and demonstrated successful inhibition of DNMT1 expression by AS/MT at the protein level, using gastric cancer cell lines in vitro. E-cadherin protein expression was increased, and both cyclin D1 and PCNA were decreased by AS/MT treatment. AS/MT also induced suppression of cell growth as determined by BrDU uptake incorporation, in a dose-dependent manner, suggesting specificity of AS/MT. Simultaneously, morphological alterations were observed in both TMK-1 and MKN-45 cells after 24 h incubation with 2 micro M of AS/MT. The cells changed shape from their original forms to dispersed, fibroblast-like cells with neurite-like processes, accompanied by an increased adhesive potential of the cells. An in vivo model of peritoneal dissemination using the nude mouse system showed an increased malignant potential of AS/MT treated TMK-1 cells as demonstrated by a greater number of peritoneal tumor nodules in the AS/MT as compared to the NS/MT treated group, 34.8+/-4.3 vs. 22.4+/-3.0 nodules, respectively (p=0.0039). The total wet tumor weight in the AS/MT group (350+/-47.4 g) was significantly greater than that in the NS/MT group (248+/-41.5 g) (p=0.0065). In conclusion, the inhibition of DNA methylation by DNMT1 by an antisense oligodeoxynucleotide influences cell morphology and adhesion, as well as cell growth in gastric cancer cells in vitro. Moreover, these alterations in the characteristics of cancer cells resulted in an increased ability to attach onto the peritoneum in the nude mouse system in vivo, suggesting that strict clinical guidelines will be necessary to utilize such a DNA methylation inhibitor, since it does not always mean a therapeutic antitumor strategy. Aberrant DNA methylation plays a relevant role in multiple myeloma (MM) pathogenesis. MicroRNAs (miRNAs) are a class of small non-coding RNAs that recently emerged as master regulator of gene expression by targeting protein-coding mRNAs. However, miRNAs involvement in the regulation of the epigenetic machinery and their potential use as therapeutics in MM remain to be investigated. Here, we provide evidence that the expression of de novo DNA methyltransferases (DNMTs) is deregulated in MM cells. Moreover, we show that miR-29b targets DNMT3A and DNMT3B mRNAs and reduces global DNA methylation in MM cells. In vitro transfection of MM cells with synthetic miR-29b mimics significantly impairs cell cycle progression and also potentiates the growth-inhibitory effects induced by the demethylating agent 5-azacitidine. Most importantly, in vivo intratumor or systemic delivery of synthetic miR-29b mimics, in two clinically relevant murine models of human MM, including the SCID-synth-hu system, induces significant anti-tumor effects. All together, our findings demonstrate that aberrant DNMTs expression is efficiently modulated by tumor suppressive synthetic miR-29b mimics, indicating that methyloma modulation is a novel matter of investigation in miRNA-based therapy of MM. It has been recently shown that DNA methyl transferase overexpression is correlated with unfavourable prognosis in human malignancies while methylation deregulation remains a hallmark that defines acute myeloid leukemia (AML). The oncogenic transcription factor EVI1 is involved in methylation deregulation and its overexpression plays a major role for predicting an adverse outcome. Moreover, the identification of DNMT3A mutations in AML patients has recently been described as a poor prognostic indicator. In order to clarify relationship between these key actors in methylation mechanisms and their potential impact on patient outcomes, we analysed 195 de novo AML patients for the expression of DNMT3A, 3B (and its non-catalytic variant 3B(NC)) and their correlations with the outcome and the expression of other common prognostic genetic biomarkers (EVI1, NPM1, FLT3ITD/TKD and MLL) in adult AML. The overexpression of DNMT3B/3B(NC) is (i) significantly correlated with a shorter overall survival, and (ii) inversely significantly correlated with event-free survival and DNMT3A expression level. Moreover, multivariate analysis showed that a high expression level of DNMT3B/3B(NC) is statistically a significant independent poor prognostic indicator. This study represents the first report showing that the overexpression of DNMT3B/3B(NC) is an independent predictor of poor survival in AML. Its quantification should be implemented to the genetic profile used to stratify patients for therapeutical strategies and should be useful to identify patients who may benefit from therapy based on demethylating agents. Global DNA hypomethylation is a hallmark of cancer cells, but its molecular mechanisms have not been elucidated. Here, we show that the disruption of Dnmt1/PCNA/UHRF1 interactions promotes a global DNA hypomethylation in human gliomas. We then demonstrate that the Dnmt1 phosphorylations by Akt and/or PKC abrogate the interactions of Dnmt1 with PCNA and UHRF1 in cellular and acellular studies including mass spectrometric analyses and the use of primary cultured patient-derived glioma. By using methylated DNA immunoprecipitation, methylation and CGH arrays, we show that global DNA hypomethylation is associated with genes hypomethylation, hypomethylation of DNA repeat element and chromosomal instability. Our results reveal that the disruption of Dnmt1/PCNA/UHRF1 interactions acts as an oncogenic event and that one of its signatures (i.e. the low level of mMTase activity) is a molecular biomarker associated with a poor prognosis in GBM patients. We identify the genetic and epigenetic alterations which collectively promote the acquisition of tumor/glioma traits by human astrocytes and glial progenitor cells as that promoting high proliferation and apoptosis evasion. Changes in DNA methylation patterns is a prominent characteristic of human tumors. Tumor cells display reduced levels of genomic DNA methylation and site-specific CpG island hypermethylation. Methylation of CpG dinucleotides is catalyzed by the enzyme family of DNA methyltransferases (DNMTs). In this review, the role of DNA methylation and DNMTs as key determinants of carcinogenesis is further elucidated. The chromatin modifying proteins that are known to interact with DNMTs are also described. Finally, the role of DNMTs as potential therapeutic targets is addressed. Overexpression of the major DNA methyltransferase Dnmt1 is cytotoxic and has been hypothesized to result in aberrant hypermethylation of genes required for cell survival. Indeed, overexpression of mouse or human Dnmt1 in murine and human cell lines decreased clonogenicity. By frame-shift and deletion constructs, this effect of mouse Dnmt1 was localized at the N-terminal 124 amino acid domain, which mediates interaction with proliferating cell nuclear antigen (PCNA). Mutation of the PCNA-binding site restored normal cloning efficiencies. Overexpression of Dnmt3A or Dnmt3B, which do not interact with PCNA, yielded weaker effects on clonogenicity. Following introduction of the toxic domain, no significant effects on apoptosis, replication, or overall DNA methylation were observed for up to 3 d. Suppression of clonogenicity by Dnmt1 was also observed in cell lines lacking wild-type p53, p21(CIP1), or p16(INK4A). Suppression of clonogenicity by Dnmt1 overexpression may act as a fail-safe mechanism against carcinogenicity of sustained Dnmt1 overexpression.

Which RNA polymerase is used for the replication of viroids?

DNA-dependent RNA polymerase II of plant origin transcribes viroid RNA into full-length copies

[10664390, 6896006, 1733098, 22422064, 16593489, 6760914, 16912306, 7231549, 16406459, 11713308, 10668797]

An active replication complex of citrus exocortis viroid (CEV) was isolated as a chromatin-enriched fraction of infected tomato leaf with CEV RNA synthesis activity. This activity was solubilised from the chromatin with ammonium sulphate, but not with sarkosyl. Nucleoprotein complexes in the soluble fraction which bound to a monoclonal antibody to the carboxy terminal domain of the largest subunit of RNA polymerase II (8WG16) were affinity purified and contained plus- and minus-sense CEV RNA. The results support a role for RNA polymerase II in viroid replication and provide the first direct evidence of an association in vivo between host RNA polymerase II and CEV. RNA-dependent RNA polymerase from healthy tomato plant tissue accepts potato spindle tuber viroid (PSTV) RNA as a template for the in vitro synthesis of full-length RNA copies of the PSTV genome. Viroid transcription requires the presence of Mn2+ and /or Mg2+ ions and is not inhibited by concentrations of 10(-5) M alpha-amanitin. This is the first report of a well-defined product synthesized in vitro by an RNA-dependent RNA polymerase from healthy plants. Analysis by molecular hybridization of the RNAs transcribed by a cell-free fraction from avocado infected with avocado sunblotch viroid (ASBV) demonstrated the presence of newly synthesized viroid-specific sequences, most of which were of the same polarity as the mature infectious viroid RNA. Treatment of the cell-free fraction with DNase reduced the total synthesis of RNA considerably, but it did not influence that of the ASBV-specific RNAs, indicating that the latter were transcribed on an RNA template. Inhibition studies with alpha-amanitin showed that the synthesis of ASBV-specific RNAs was not affected by concentrations of 1 and 200 micrograms/ml of the drug, which typically inhibit RNA polymerase II and III, respectively, from most animal and plant systems. These results suggest that either RNA polymerase I or an unidentified RNA polymerase activity resistant to alpha-amanitin, acting on an RNA template, plays a role in the replication of ASBV, whereas for the rest of the viroids studied so far it appears that RNA polymerase II is involved. Analysis by polycrylamide gel electrophoresis under partially and fully denaturing conditions of the ASBV-specific RNAs synthesized in vitro showed that they contain unit and longer than unit length viroid strands, probably associated in complexes with single- and double-stranded regions. The structural properties of these complexes are similar to those of the RNAs accumulating in vivo in viroid-infected tissues, which are the postulated replicative intermediates of the rolling-circle mechanism proposed for viroid synthesis. Potato spindle tuber viroid (PSTVd) is a small, single-stranded, circular, non-coding RNA pathogen. Host DNA-dependent RNA polymerase II (RNAP II) was proposed to be critical for its replication, but no interaction site for RNAP II on the PSTVd RNA genome was identified. Using a co-immunoprecipitation strategy involving a mAb specific for the conserved heptapeptide (i.e. YSPTSPS) located at the carboxy-terminal domain of the largest subunit of RNAP II, we established the interaction of tomato RNAP II with PSTVd RNA and showed that RNAP II associates with the left terminal domain of PSTVd (+) RNA. RNAP II did not interact with any of several PSTVd (-) RNAs tested. Deletion and site-directed mutagenesis of a shortened model PSTVd (+) RNA fragment were used to identify the role of specific nucleotides and structural motifs in this interaction. Our results provide evidence for the interaction of a RNAP II complex from a natural host with the rod-like conformation of the left terminal domain of PSTVd (+) RNA. Cell-free synthesis of citrus exocortis viroid (CEV) in nuclei-rich preparations from infected Gynura aurantiaca was optimum at 18-24 degrees C. Incubation of reaction mixtures at higher temperatures (30-36 degrees C) resulted in an increase of CEV linear molecules and the recovery of incomplete or nicked newly synthesized RNA species. Although the Mg(2+) optimum (2.5-5 mM) for CEV synthesis was lower than that for total [(32)P]CMP incorporation (10 mM), the response to Mn(2+) ion was distinctly different. Whereas maximum total activity was observed in 1 mM Mn(2+) with a pronounced reduction (80%) in 5 mM Mn(2+), CEV synthesis was maintained in 1-15 mM Mn(2+). Inhibition of alpha-amanitin-sensitive CEV synthesis in 200 mM (NH(4))(2)SO(4) resembles the reaction of RNA polymerase II on a free nucleic acid template. However, detection of trace levels of alpha-amanitin-resistant CEV synthesis activity inhibited by low (NH(4))(2)SO(4) concentrations (25 mM) suggests the possible involvement of RNA polymerase I- and/or III-like activity. The RNA genome of potato spindle tuber viroid (PSTV) is transcribed in vitro into complementary DNA and RNA by DNA-dependent DNA polymerase I and RNA polymerase, respectively, from Escherichia coli. In vitro synthesis of complementary RNA produces distinct transcripts larger than unit length thus reflecting the in vivo mechanism of viroid replication. The influence of varying experimental conditions on the transcription process is studied; actinomycin D is found to drastically reduce complementary RNA synthesis from the PSTV RNA template by RNA polymerase. RNA-templated RNA replication is essential for viral or viroid infection, as well as for regulation of cellular gene expression. Specific RNA motifs likely regulate various aspects of this replication. Viroids of the Pospiviroidae family, as represented by the Potato spindle tuber viroid (PSTVd), replicate in the nucleus by utilizing DNA-dependent RNA polymerase II. We investigated the role of the loop E (sarcin/ricin) motif of the PSTVd genomic RNA in replication. A tertiary-structural model of this motif, inferred by comparative sequence analysis and comparison with nuclear magnetic resonance and X-ray crystal structures of loop E motifs in other RNAs, is presented in which core non-Watson-Crick base pairs are precisely specified. Isostericity matrix analysis of these base pairs showed that the model accounts for the reported natural sequence variations and viable experimental mutations in loop E motifs of PSTVd and other viroids. Furthermore, isostericity matrix analysis allowed us to design disruptive, as well as compensatory, mutations of PSTVd loop E. Functional analyses of such mutants by in vitro and in vivo experiments demonstrated that loop E structural integrity is crucial for replication, specifically during transcription. Our results suggest that the PSTVd loop E motif exists and functions in vivo and provide loss-of-function genetic evidence for the essential role of a viroid RNA three-dimensional motif in rolling-circle replication. The use of isostericity matrix analysis of non-Watson-Crick base pairing to rationalize mutagenesis of tertiary motifs and systematic in vitro and in vivo functional assays of mutants offers a novel, comprehensive approach to elucidate the tertiary-structure-function relationships for RNA motifs of general biological significance. DNA-dependent RNA polymerase II purified from healthy plant tissue is capable of synthesizing linear (-)-viroid RNA copies of full length from (+)-viroid RNA templates in vitro. Together with the specific alpha-amanitin sensitivity of viroid replication observed in vivo, these findings suggest that viroids replicate by an entirely novel mechanism in which infecting viroid RNA molecules are copied by the host enzyme which is normally responsible for the synthesis of nuclear precursors to messenger RNA. Viroids are single-stranded, circular RNAs of 250 to 400 bases, that replicate autonomously in their host plants but do not code for a protein. Viroids of the family Pospiviroidae, of which potato spindle tuber viroid (PSTVd) is the type strain, are replicated by the host's DNA-dependent RNA polymerase II in the nucleus. To analyze the initiation site of transcription from the (+)-stranded circles into (-)-stranded replication intermediates, we used a nuclear extract from a non-infected cell culture of the host plant S. tuberosum. The (-)-strands, which were de novo-synthesized in the extract upon addition of circular (+)-PSTVd, were purified by affinity chromatography. This purification avoided contamination by host nucleic acids that had resulted in a misassignment of the start site in an earlier study. Primer-extension analysis of the de novo-synthesized (-)-strands revealed a single start site located in the hairpin loop of the left terminal region in circular PSTVd's secondary structure. This start site is supported further by analysis of the infectivity and replication behavior of site-directed mutants in planta. Pospiviroidae, with their main representative potato spindle tuber viroid (PSTVd), are replicated via a rolling circle mechanism by the host-encoded DNA-dependent RNA polymerase II (pol II). In the first step, the (+)-strand circular viroid is transcribed into a (-)-strand oligomer intermediate. As yet it is not known whether transcription is initiated by promotors at specific start sites or is distributed non-specifically over the whole circle. An in vitro transcription extract was prepared from a non-infected potato cell culture which exhibited transcriptional activity using added circular PSTVd (+)-strand RNA as template. In accordance with pol II activity, transcription could be inhibited by alpha-amanitin. RT-PCR revealed the existence of at least two different start sites and primer extension identified these as nucleotides A(111) and A(325). The sequences of the first 7 nt transcribed are very similar, (105)GGAGCGA(111) and (319)GGGGCGA(325). GC-boxes are located at a distance of 15 and 16 nt upstream, respectively, in the native viroid structure, which may act to facilitate initiation. The GC-boxes may have a similar function to the GC-rich hairpin II in the (-)-strand intermediate, as described previously. The results are compared with the corresponding features of avocado sunblotch viroid, which belongs to a different family of viroids and exhibits different transcription initiation properties. RNA polymerase II is implicated in the RNA-templated RNA synthesis during replication of viroids and Hepatitis Delta Virus (HDV); however, neither the RNA template nor protein factor requirements for this process are well defined. We have developed an in vitro transcription system based on HeLa cell nuclear extract (NE), in which a segment of antigenomic RNA corresponding to the left-hand tip region of the HDV rod-like structure serves as a template for efficient and highly specific RNA synthesis. Accumulation of the unique RNA product is highly sensitive to alpha-amanitin in HeLa NE and only partially sensitive to this drug in NE from PMG cells that contain an allele of the alpha-amanitin-resistant subunit of pol II, strongly suggesting pol II involvement in this reaction. Detailed analysis of the RNA product revealed that it represents a chimeric molecule composed of a newly synthesized transcript covalently attached to the 5' half of the RNA template. Selection of the start site for transcription is remarkably specific and depends on the secondary structure of the RNA template, rather than on its primary sequence. Some features of this reaction resemble the RNA cleavage-extension process observed for pol II-arrested complexes in vitro. A possible involvement of the described reaction in HDV replication is discussed.

List Parkin binding partners

HSP90 CDC37 GRP75 HSP60 LRPPRC TUFM PICK1 PSMA7 Pael receptor

[18623069, 17229476, 17553932, 24244333, 14579121, 20064468, 15987638, 18190519, 16842202, 16714300, 21437181]

Dysregulation of genes that control cell-cycle progression and DNA repair is a hallmark of tumorigenesis. It is becoming increasingly apparent, however, that these defects also contribute to degeneration of post-mitotic neurons under certain conditions. The gene for ataxia-telangiectasia mutated (ATM) is a prototype for this dual mechanism of action, with loss-of-function mutations causing not only selective degeneration of cerebellar neurons but also increased susceptibility to breast cancer and hematologic malignancy. Increased dosage of amyloid precursor protein in Down syndrome (trisomy 21) predisposes to dementia of Alzheimer type and may also contribute to acute leukemia and transient myeloproliferative disorder. The gene parkin, loss-of-function mutations in which account for about half of cases of early-onset Parkinson disease, has been identified as a candidate tumor suppressor gene by several groups. Parkin is deleted or downregulated in several tumor types, and its re-expression sensitizes derivative cell lines to inhibitors of cell-cycle progression. The overlap of molecular pathways implicated in cancer and neurodegeneration challenges long-held notions about differentiated cellular states and may open the door to novel therapeutic approaches to both groups of disorders. p193/CUL7 is an E3 ubiquitin ligase initially identified as an SV40 Large T Antigen binding protein. Expression of a dominant interfering variant of mouse p193/CUL7 (designated 1152stop) conferred resistance to MG132- and etoposide-induced apoptosis in U2OS cells. Immune precipitation/Western analyses revealed that endogenous p193/CUL7 formed a complex with Parc (a recently identified parkin-like ubiquitin ligase) and p53. Apoptosis resistance did not result from 1152stop-mediated disruption of the endogenous p193/CUL7 binding partners. Moreover, 1152stop molecule did not directly bind to endogenous p193/CUL7, Parc or p53. These data suggested a role for p193/CUL7 in the regulation of apoptosis independently of p53 and Parc activity. Autosomal recessive juvenile parkinsonism (AR-JP) is caused by mutations of the parkin gene. Parkin is an E3 ubiquitin ligase that specifically recognizes its substrate protein, promoting its ubiquitination and subsequent degradation. Accordingly, we hypothesized that AR-JP may be caused by accumulation of an unidentified neurotoxic protein, which is a substrate of parkin. Based on this hypothesis, we cloned parkin-binding protein using a yeast two-hybrid system and identified a putative G protein-coupled receptor protein,which we named the Pael receptor (Pael-R). When overexpressed in cells, this receptor became unfolded, insoluble, and ubiquitinated. Accumulation of the insoluble Pael-R subsequently led to endoplasmic reticulum (ER) stress-induced cell death. Parkin specifically ubiquitinates the unfolded Pael-R and promotes its degradation, resulting in suppression of cell death induced by the accumulation of unfolded Pael-R. Moreover, insoluble Pael-R accumulates in the brains of AR-JP patients. It is highly expressed by the dopaminergic neurons of the substantia nigra, strongly suggesting that accumulation of unfolded Pael-R may lead to selective death of dopaminergic neurons in AR-JP.Recently, we identified Hsp70 and its co-chaperone CHIP as novel parkin-binding partners. We found that CHIP enhanced parkinmediated ubiquitination of Pael-R. In concert with Hsp70, CHIP also enhanced the ability of parkin to inhibit cell death induced by Pael-R, indicating that CHIP and Hsp70 are both co-factors of parkin. Mutations in the parkin gene are responsible for a common inherited form of Parkinson's disease (PD). Parkin is a RING-type E3 ubiquitin ligase with an N-terminal ubiquitin-like domain (Ubl). We report here that the parkin Ubl binds SH3 domains from endocytic BAR proteins such as endophilin-A with an affinity comparable to proline-rich domains (PRDs) from well-established SH3 partners. The NMR structure of the Ubl-SH3 complex identifies the PaRK extension, a unique C-terminal motif in the parkin Ubl required for SH3 binding and for parkin-mediated ubiquitination of endophilin-A in vitro. In nerve terminals, conditions that promote phosphorylation enhance the interaction between parkin and endophilin-A and increase the levels of ubiquitinated proteins within PRD-associated synaptic protein complexes in wild-type but not parkin knockout brain. The findings identify a pathway for the recruitment of synaptic substrates to parkin with the potential to explain the defects in synaptic transmission observed in recessive forms of PD. CASK, which belongs to the family of membrane-associated guanylate kinase (MAGUK) proteins, is recognized as a multidomain scaffolding protein highly expressed in the mammalian nervous system. MAGUK proteins generally target to neuronal synapses and regulate trafficking, targeting, and signaling of ion channels. However, CASK is a unique MAGUK protein in several respects. It not only plays a role in synaptic protein targeting but also contributes to neural development and regulation of gene expression. Several CASK-interacting proteins have been identified from yeast two-hybrid screening and biochemical isolation. These proteins, whose interactions with CASK are reviewed here, include the Parkinson's disease molecule parkin, the adhesion molecule neurexin, syndecans, calcium channel proteins, the cytoplasmic adaptor protein Mint1, Veli/mLIN-7/MALS, SAP97, caskin and CIP98, transcription factor Tbr-1, and nucleosome assembly protein CINAP. More important, CASK may form different complexes with different binding partners and perform different functions. Among these interactions, CASK, Tbr-1, and CINAP can form a transcriptional complex regulating gene expression. Reelin and NMDAR subunit 2b (NR2b) genes have been identified as Tbr-1 target genes. Reelin is critical for neural development. NR2b is an important subunit of NMDAR, which plays important roles in neural function and neurological diseases. Regulation of reelin and NR2b expression suggests the potential roles of the Tbr-1-CASK-CINAP complex in neural activity, development, and disease. The functions of these CASK protein complexes are also discussed in detail in this review. Mutations in the parkin gene, encoding an E3 ubiquitin-protein ligase, are a frequent cause of autosomal recessive parkinsonism and are also involved in sporadic Parkinson's disease. Loss of Parkin function is thought to compromise the polyubiquitylation and proteasomal degradation of specific substrates, leading to their deleterious accumulation. Several studies have analyzed the effects of parkin gene mutations on the biochemical properties of the protein. However, the absence of a cell-free system for studying intrinsic Parkin activity has limited the interpretation of these studies. Here we describe the biochemical characterization of Parkin and 10 pathogenic variants carrying amino-acid substitutions throughout the sequence. Mutations in the RING fingers or the ubiquitin-like domain decreased the solubility of the protein in detergent and increased its tendency to form visible aggregates. None of the mutations studied compromised the binding of Parkin to a series of known protein partners/substrates. Moreover, only two variants with substitutions of conserved cysteine residues of the second RING finger were inactive in a purely in vitro ubiquitylation assay, demonstrating that loss of ligase activity is a minor pathogenic mechanism. Interestingly, in this in vitro assay, Parkin catalyzed the linkage of single ubiquitin molecules only, whereas the ubiquitin-protein ligases CHIP and Mdm2 promoted the formation of polyubiquitin chains. Similarly, in mammalian cells Parkin promoted the multimonoubiquitylation of its substrate p38, rather than its polyubiquitylation. Thus, Parkin may mediate polyubiquitylation or proteasome-independent monoubiquitylation depending on the protein context. The discovery of monoubiquitylated Parkin species in cells hints at a novel post-translational modification potentially involved in the regulation of Parkin function. Recent publications suggest that the Parkinson's disease- (PD-) related PINK1/Parkin pathway promotes elimination of dysfunctional mitochondria by autophagy. We used tandem affinity purification (TAP), SDS-PAGE, and mass spectrometry as a first step towards identification of possible substrates for PINK1. The cellular abundance of selected identified interactors was investigated by Western blotting. Furthermore, one candidate gene was sequenced in 46 patients with atypical PD. In addition to two known binding partners (HSP90, CDC37), 12 proteins were identified using the TAP assay; four of which are mitochondrially localized (GRP75, HSP60, LRPPRC, and TUFM). Western blot analysis showed no differences in cellular abundance of these proteins comparing PINK1 mutant and control fibroblasts. When sequencing LRPPRC, four exonic synonymous changes and 20 polymorphisms in noncoding regions were detected. Our study provides a list of putative PINK1 binding partners, confirming previously described interactions, but also introducing novel mitochondrial proteins as potential components of the PINK1/Parkin mitophagy pathway.

What is generic name of drug Adempas?

Riociguat is generic name of drug Adempas. It is a soluble guanylate cyclase stimulator that was approved for the treatment of patients with chronic thromboembolic pulmonary hypertension and pulmonary arterial hypertension.

[24391396, 24218053, 25395817, 25352393, 24524094]

Duavee, an oral contraceptive; riociguat (Adempas) for two types of pulmonary hypertension; and macitentan (Opsumit) for pulmonary arterial hypertension. Riociguat (Adempas(®)), a soluble guanylate cyclase stimulator, is a new, first-in-class drug approved for the treatment of patients with chronic thromboembolic pulmonary hypertension (CTEPH) [inoperable or persistent/recurrent following surgery] or pulmonary arterial hypertension (PAH). It has been designated an orphan medicine by the European Medicines Agency and the US FDA. This article reviews the available pharmacological properties of oral riociguat and its clinical efficacy and tolerability in adults with CTEPH or PAH. Riociguat is effective and well tolerated in patients with inoperable CTEPH or persistent/recurrent CTEPH following pulmonary endarterectomy, and in patients with PAH. It has a positive result on exercise capacity and pulmonary haemodynamics, and improves WHO functional class. Most adverse events can be attributed to the vasodilatory mechanism of riociguat; however, there is a potential for serious bleeding and fetal harm, and riociguat use is contraindicated in pregnant patients. Pulmonary endarterectomy remains the first treatment of choice for CTEPH, as it is potentially curative. Head-to-head trials comparing riociguat with the approved phosphodiesterase type 5 inhibitors in patients with PAH would be of value for the placement of riociguat in the management of this disease. Riociguat is a promising addition to the treatment options for patients with CTEPH or PAH. Pulmonary hypertension (PH) is a progressive disease that is accompanied by a poor prognosis. Pulmonary vasoconstriction is facilitated through multiple pathways and results in increased pulmonary vascular pressure leading to cell proliferation, vascular remodeling, right ventricular hypertrophy/failure, and ultimately death. Until recently, just six medications were approved -all for one subclass of PH. On October 8, 2013, riociguat (Adempas®) became the first medication approved for multiple etiologies of PH. Preclinical studies have demonstrated safety and efficacy with significant clinical trials supporting its advancement into phase IV trials. Although long-term safety and efficacy and place in therapy remain to be established, riociguat presents as an exciting new option for the treatment of PH and potentially has additional indications in the near future.

What is known about Vancomycin dosing in neonates?

Staphylococcus epidermis, including methicillin-resistant strains, are inhibited by vancomycin concentrations of 1-4 µg/ml. Staphylococcus pyogenes, Streptococcus pneumonia, and Streptococcus viridans are susceptible to 2 µg/ml vancomycin. Bacillus spp. are inhibited by 2 µg/ml, Corynebacterium spp. by 0.04-3.1 µg/ml and Clostridium spp. by 0.39-6 µg/ml vancomycin. Peak and trough concentrations of vancomycin should be 40 μg/ml and 10 μg/ml, respectively, to both be effective and avoid oto- or nephrotoxicity in adults. There is no ideal pattern of vancomycin dosing; vancomycin dosages must be individualized. Because vancomycin activity is primarily time-dependent, the 24-h area under the curve (AUC0-24h) divided by the minimum inhibitor concentration (MIC) value (AUC0-24h/MIC) is a better predictor of efficacy. In adults with MIC values less than 1 μg/ml, trough concentrations greater than 10 µg/ml result in AUC0-24h/MIC values 400 Compared with adults, neonates have a higher extracellular fluid volume and a limited renal elimination capacity resulting in different pharmacokinetics subject to maturation stage. Infants weighing less than 1,000 gm had significantly larger volumes of drug distribution and consequently longer drug half-lives than larger premature infants, regardless of postconceptual or actual age. These differences alter the vancomycin dosing recommendations in these two groups of premature infants. Vancomycin-associated nephrotoxicity is rare in neonates, even with serum peak concentrations 40 microg/mL. Vancomycin is associated with ototoxicity. There is no consensus on vancomycin dosing in newborns and young infants, which leads to significant variation in vancomycin dosing regimens and TDM guidance across neonatal units. The development of standardized, evidence-based protocols should be prioritized.

[21455009, 22892931, 21862473, 10103340, 22488303, 3991250, 11378679, 2630235, 10801244, 21378399]

BACKGROUND: Aminoglycoside-induced ototoxicity has been reported in neonates but its incidence is poorly defined, whereas vancomycin-induced ototoxicity has not been reported in neonates. OBJECTIVE: To compare hearing test results in infants in a neonatal intensive care unit (NICU) who were or were not treated with extended interval gentamicin dosing and/or standard vancomycin dosing. METHOD: A database of otoacoustic emissions (OAE), over a 5-year period of NICU admissions, was combined with databases of gentamicin and vancomycin dosing to compare patients treated or not treated with these antibiotics. RESULTS: A total of 2,347 OAE results was available. OAE failure rates were: no gentamicin and no vancomycin (noGnoV), 7% (85/1,233); gentamicin but no vancomycin (GnoV), 4% (42/949); vancomycin but no gentamicin (VnoG), 22% (9/41) and gentamicin and vancomycin (GandV), 14% (17/124). Compared to noGnoV there was a decreased risk of OAE failure in GnoV (p = 0.022, OR 0.64, 95% CI 0.44-0.94) and an increased risk in VnoG (p = 0.003, OR 3.46, 95% CI 1.54-7.75) and GandV, (p = 0.006, OR 2.20, 95% CI 1.26-3.83). CONCLUSIONS: Gentamicin, as used and evaluated in this audit, showed no evidence of an increased risk of ototoxicity; what was observed was a statistically significant decrease in OAE failure rate. Vancomycin, by contrast, was associated with ototoxicity. Neonatal sepsis is common and is a major cause of morbidity and mortality. Vancomycin is the preferred treatment of several neonatal staphylococcal infections. The aim of this study was to review published data on vancomycin pharmacokinetics in neonates and to provide a critical analysis of the literature. A bibliographic search was performed using PubMed and Embase, and articles with a publication date of August 2011 or earlier were included in the analysis. Vancomycin pharmacokinetic estimates, which are different in neonates compared with adults, also exhibit extensive inter-neonatal variability. In neonates, several vancomycin dosing schedules have been proposed, mainly based on age (i.e., postmenstrual and postnatal), body weight or serum creatinine level. Other covariates [e.g., extracorporeal membrane oxygenation (ECMO), indomethacin or ibuprofen, and growth restriction] of vancomycin pharmacokinetics have been reported in neonates. Finally, vancomycin penetrates cerebrospinal fluid (range = 7-42%). Renal function drives vancomycin pharmacokinetics. Because either age or weight is the most relevant covariate of renal maturation, these covariates should be considered first in neonatal vancomycin dosing guidelines and further adjusted by renal dysfunction indicators (e.g., ECMO and ibuprofen/indomethacin). In addition to the prospective validation of available dosing guidelines, future studies should focus on the relevance of therapeutic drug monitoring and on the value of continuous vancomycin administration in neonates. OBJECTIVE: The purpose of this study was to compare the incidence of nephrotoxicity, defined as doubling of baseline serum creatinine concentration, in newborn infants with peak vancomycin serum concentrations </=40 microg/mL at steady state to infants with peak vancomycin serum concentrations >40 microg/mL. A secondary objective was to correlate concomitant disease states and potentially nephrotoxic drug therapy with rises in serum creatinine in vancomycin recipients. METHODS: Newborn infants with culture-proven Staphylococcus aureus or coagulase-negative staphylococcal septicemia who received vancomycin therapy for >3 days between 1985 and 1995 were identified from an existing database and a review of medical record. All 69 patients included in the study had serial serum creatinine determinations, including a baseline value within 48 hours of starting treatment with vancomycin, and serum vancomycin concentrations determined after at least three doses, with peak and trough concentrations determined 1 hour after a 60-minute infusion and 15 to 30 minutes before a dose, respectively. Infants with congenital renal or cardiac anomalies were excluded. Demographic characteristics, vancomycin dosing regimen, serum vancomycin concentrations and sample times, concomitant drug therapy, and disease states were recorded. Patients were divided into group A (peak vancomycin concentration </=40 microg/mL) and group B (peak vancomycin concentration >40 microg/mL). The change in serum creatinine concentration between the start and end of vancomycin therapy was determined. Nephrotoxicity was identified if serum creatinine doubled at any time from the start to the end of vancomycin therapy. Alternative definitions of nephrotoxicity (any rise in serum creatinine to >0.6 mg/dL or new abnormalities of urine sediment) were used in additional analyses. RESULTS: A total of 69 evaluable patients (gestational age, 28.9 +/- 3.0 weeks; birth weight, 1219 +/- 516 g) were identified, 61 in group A and 8 in group B. Six patients in group A underwent doubling of serum creatinine concentration during vancomycin therapy, whereas none in group B did so. Serum creatinine doubled to >0.6 mg/dL in only 3 infants (all in group A). Any increase in serum creatinine to >0.6 mg/dL was seen in 10 infants, 9 of whom were in group A. No confounding variable, including previous or concomitant underlying disease states associated with renal dysfunction or treatment with other potentially nephrotoxic agents, were associated with a significant rise in serum creatinine. CONCLUSION: Vancomycin-associated nephrotoxicity is rare in neonates, even with serum peak concentrations >40 microg/mL. STUDY OBJECTIVE: To compare four common dosing regimens for vancomycin in preterm and term neonates by assessing the probability that each regimen would achieve the widely used therapeutic target serum trough concentrations of 5-15 mg/L and the newly suggested target of 15-20 mg/L. DESIGN: Retrospective population pharmacokinetic analysis using therapeutic drug monitoring data obtained from 1990-2007, with a subsequent simulation study performed on the pharmacokinetic model. SETTING: Tertiary-care children's hospital. PATIENTS: One hundred thirty-four preterm (66%) and term (34%) neonates, with a postnatal age of 1-121 days and postmenstrual age of 24.6-44 weeks. MEASUREMENTS AND MAIN RESULTS: Therapeutic drug monitoring data for vancomycin were used to develop a population pharmacokinetic model in the target population. Parameter estimates for the derived pharmacostatistical model were used to perform Monte Carlo simulations for four recommended dosing regimens: a standard dose for all neonates, postmenstrual age-based dosing, postmenstrual and postnatal age-based dosing, and serum creatinine-based dosing. Multivariate age-weight distributions were established for term and preterm neonates using Centers for Disease Control and Prevention growth charts and intrauterine and postnatal growth charts from the literature, respectively. Each dosing regimen was treated as a separate scenario in which 200 replicates with 100 patients/replicate were simulated. The 5-15-mg/L target trough serum concentration was achieved in 34% (90% confidence interval [CI] 20-53%), 42% (90% CI 31-55%), 52% (90% CI 43-60%), and 63% (90% CI 54-72%) of patients receiving the standard dose, postmenstrual age-based dose, postmenstrual and postnatal age-based dose, and serum creatinine-based dose, respectively. Serum creatinine-based dosing produced trough concentrations predominantly in the 5-15-mg/L target range, with the smallest variability in both term and preterm neonates. As expected, when the target range was narrow and higher (15-20 mg/L), only 13-21% of patients were within the range across the four dosing regimens. CONCLUSION: Monte Carlo simulations based on our population pharmacokinetic model suggest that vancomycin dosing guidelines based on serum creatinine concentration have a greater likelihood of achieving trough concentrations in the 5-15-mg/L range compared with other evaluated dosing regimens. None of the four dosing regimens is suitable to produce target trough concentration of 15-20 mg/L in an acceptable number of patients. Vancomycin pharmacokinetics were studied in nine premature infants. Infants weighing less than 1,000 gm had significantly larger volumes of drug distribution and consequently longer drug half-lives than larger premature infants, regardless of postconceptual or actual age. These differences alter the vancomycin dosing recommendations in these two groups of premature infants. We recommend initial dosage regimens consisting of a loading dose of vancomycin of 25 mg/kg followed by doses of 15 mg/kg every 12 hours for infants with weights less than 1,000 gm. Infants weighing over 1,000 gm should receive 10 mg/kg every 12 hours, with a loading dose of 12.5 mg/kg. Serum vancomycin concentration should be monitored, however, for final optimization of therapy. Multidose pharmacokinetics of vancomycin were studied in 15 infants with gestational age less than 36 weeks and suspected or confirmed Staphylococcus epidermidis infections. Postconceptional age (PCA) at the time of the study ranged from 26 to 44 weeks. Vancomycin individual doses ranged from 6.7 to 10.6 mg/kg and were infused over 60 min. Five postinfusion samples were obtained in 13 infants, while 4 samples were obtained in 2 patients. Vancomycin pharmacokinetic parameters were determined by fitting the data to a two-compartment model using a weighted least-squares nonlinear regression method. Mean vancomycin body clearance (CL), volume of distribution (Vdss) and terminal elimination half-life were 1.37 ml/min, 0.58 liters and 5.6 h, respectively. When standardized for patient weight, the CL and Vdss values were 1.07 ml/min/kg and 0.48 liters/kg, respectively. The CL (ml/min/kg) was strongly inversely correlated with the serum creatinine (r = -0.82), while a weaker but significant association was noted with PCA (r = 0.41). These data suggest that in sick infants, in addition to the PCA, serum creatinine should be considered when determining the initial vancomycin dosing regimen. BACKGROUND: Recently the value of vancomycin therapeutic drug monitoring, as well as the required therapeutic range, has been subject of debate, resulting in new recommendations. This study was performed to incorporate these new insights in an up-to-date dosing scheme for neonates of various gestational ages. METHODS: In this retrospective study with prospective validation, 108 newborns with suspected central line-related septicemia during the first month of life received 30 mg/kg/day vancomycin divided into two doses regardless of gestational or postconceptional age. Trough and peak vancomycin serum concentrations were determined before and after the third dose. Vancomycin data were analyzed according to a one-compartment open model with use of NONMEM population pharmacokinetic software. Model parameters were evaluated and then used to simulate vancomycin dosing for different dose and dose interval combinations. Targets were a trough concentration between 5 and 15 mg/L and a peak below 40 mg/L. In the prospective study, the optimal scheme was tested in 22 patients. RESULTS: Of the 108 patients, 34.3% of measured trough concentrations and 17.6% of peak concentrations were outside the desired therapeutic range. The model that best fitted the data included clearance and volume per kilogram and was independent of gestational age. Simulation of various dosing schemes showed that a dosing schedule of 30 mg/kg/day, irrespective of gestational age, in three doses was optimal, and this scheme was prospectively tested. Mean trough concentrations before the second dose were 8.2 +/- 2.2 mg/L versus a predicted trough of 8.9 +/- 2.5 mg/L. No peak levels higher than 40 mg/L were found. CONCLUSIONS: The use of the proposed schedule leads to adequate vancomycin trough serum concentrations, and there is no need for routine monitoring of peak serum concentrations. BACKGROUND: There is no consensus on vancomycin dosing in newborns and young infants. OBJECTIVE: The first objective was to assess the efficiency of a simplified dosing regimen with a cohort study. The secondary objective was to examine pharmacokinetic data to determine how this simplified dosing could be improved. METHODS: All neonates admitted to our intensive care unit and treated with vancomycin were included in the pharmacokinetic study (PK group, 83 treatments, 156 measurements). The vancomycin dosing regimen consisted of a loading dose of 7 mg/kg, followed by a constant continuous dose of 30 mg/kg/day. The target serum vancomycin concentration ranged from 10 mg/l to 30 mg/l. Data from patients whose medications followed the scheduled dosing without modifications or prescription errors (actual dosing group: 62 treatments, 108 measurements) were analysed separately. A population pharmacokinetic analysis was performed (PK group) to simulate several vancomycin dosings. RESULTS: Prescription errors were found in 10 of 83 treatments (12%). In the actual dosing group, 89.2% of vancomycin measurements were within the target range. Serum creatinine remained stable throughout treatment. Vancomycin concentrations varied widely. The modified regimen for a target vancomycin concentration of 25 mg/l consisted of a bolus of 20 mg/kg followed by continuous infusion of 30 mg/kg. CONCLUSION: Our pharmacokinetic data and bedside results suggest that a simplified schedule of vancomycin can achieve the targeted drug concentrations in most patients while avoiding secondary renal toxicity. The proposed new dosing scheme should be validated in a drug survey, but due to pharmacokinetic variability, still requires therapeutic drug monitoring.

Is single guide RNA part of the CRISPR/Cas9 tool or an inhibitor of its function?

Single guide RNA is part of the CRISPR/Cas9 system.

[25713377, 24870050, 23907171, 25048165, 25398342, 25239977, 24710347, 24920971, 24838573, 25161872, 24825012, 25731961, 25122746, 25274302, 25437567]

Cas9, an RNA-guided DNA endonuclease found in clustered regularly interspaced short palindromic repeats (CRISPR) bacterial immune systems, is a versatile tool for genome editing, transcriptional regulation, and cellular imaging applications. Structures of Streptococcus pyogenes Cas9 alone or bound to single-guide RNA (sgRNA) and target DNA revealed a bilobed protein architecture that undergoes major conformational changes upon guide RNA and DNA binding. To investigate the molecular determinants and relevance of the interlobe rearrangement for target recognition and cleavage, we designed a split-Cas9 enzyme in which the nuclease lobe and α-helical lobe are expressed as separate polypeptides. Although the lobes do not interact on their own, the sgRNA recruits them into a ternary complex that recapitulates the activity of full-length Cas9 and catalyzes site-specific DNA cleavage. The use of a modified sgRNA abrogates split-Cas9 activity by preventing dimerization, allowing for the development of an inducible dimerization system. We propose that split-Cas9 can act as a highly regulatable platform for genome-engineering applications. Prokaryotic type II CRISPR-Cas systems can be adapted to enable targeted genome modifications across a range of eukaryotes. Here we engineer this system to enable RNA-guided genome regulation in human cells by tethering transcriptional activation domains either directly to a nuclease-null Cas9 protein or to an aptamer-modified single guide RNA (sgRNA). Using this functionality we developed a transcriptional activation-based assay to determine the landscape of off-target binding of sgRNA:Cas9 complexes and compared it with the off-target activity of transcription activator-like (TALs) effectors. Our results reveal that specificity profiles are sgRNA dependent, and that sgRNA:Cas9 complexes and 18-mer TAL effectors can potentially tolerate 1-3 and 1-2 target mismatches, respectively. By engineering a requirement for cooperativity through offset nicking for genome editing or through multiple synergistic sgRNAs for robust transcriptional activation, we suggest methods to mitigate off-target phenomena. Our results expand the versatility of the sgRNA:Cas9 tool and highlight the critical need to engineer improved specificity. CRISPR-Cas encodes an adaptive immune system that defends prokaryotes against infectious viruses and plasmids. Immunity is mediated by Cas nucleases, which use small RNA guides (the crRNAs) to specify a cleavage site within the genome of invading nucleic acids. In type II CRISPR-Cas systems, the DNA-cleaving activity is performed by a single enzyme Cas9 guided by an RNA duplex. Using synthetic single RNA guides, Cas9 can be reprogrammed to create specific double-stranded DNA breaks in the genomes of a variety of organisms, ranging from human cells to bacteria, and thus constitutes a powerful tool for genetic engineering. Here we describe recent advancements in our understanding of type II CRISPR-Cas immunity and how these studies led to revolutionary genome editing applications. The clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 system has become a powerful and precise tool for targeted gene modification (e.g., gene knockout and gene replacement) in numerous eukaryotic organisms. Initial attempts to apply this technology to a model, the single-cell alga, Chlamydomonas reinhardtii, failed to yield cells containing edited genes. To determine if the Cas9 and single guide RNA (sgRNA) genes were functional in C. reinhardtii, we tested the ability of a codon-optimized Cas9 gene along with one of four different sgRNAs to cause targeted gene disruption during a 24-h period immediately following transformation. All three exogenously supplied gene targets as well as the endogenous FKB12 (rapamycin sensitivity) gene of C. reinhardtii displayed distinct Cas9/sgRNA-mediated target site modifications as determined by DNA sequencing of cloned PCR amplicons of the target site region. Success in transient expression of Cas9 and sgRNA genes contrasted with the recovery of only a single rapamycin-resistant colony bearing an appropriately modified FKB12 target site in 16 independent transformation experiments involving >10(9) cells. Failure to recover transformants with intact or expressed Cas9 genes following transformation with the Cas9 gene alone (or even with a gene encoding a Cas9 lacking nuclease activity) provided strong suggestive evidence for Cas9 toxicity when Cas9 is produced constitutively in C. reinhardtii. The present results provide compelling evidence that Cas9 and sgRNA genes function properly in C. reinhardtii to cause targeted gene modifications and point to the need for a focus on development of methods to properly stem Cas9 production and/or activity following gene editing. Genetic modification, including plant breeding, has been widely used to improve crop yield and quality, as well as to increase disease resistance. Targeted genome engineering is expected to contribute significantly to future varietal improvement, and genome editing technologies using zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9/single guide RNA (sgRNA) have already been successfully used to genetically modify plants. However, to date, there has been no reported use of any of the current genome editing approaches in sweet orange, an important fruit crop. In this study, we first developed a novel tool, Xcc-facilitated agroinfiltration, for enhancing transient protein expression in sweet orange leaves. We then successfully employed Xcc-facilitated agroinfiltration to deliver Cas9, along with a synthetic sgRNA targeting the CsPDS gene, into sweet orange. DNA sequencing confirmed that the CsPDS gene was mutated at the target site in treated sweet orange leaves. The mutation rate using the Cas9/sgRNA system was approximately 3.2 to 3.9%. Off-target mutagenesis was not detected for CsPDS-related DNA sequences in our study. This is the first report of targeted genome modification in citrus using the Cas9/sgRNA system-a system that holds significant promise for the study of citrus gene function and for targeted genetic modification. BACKGROUND: The type II clustered, regularly interspaced, short palindromic repeat (CRISPR)/ CRISPR-associated protein 9 (Cas9) system is a novel molecular tool for site-specific genome modification. The CRISPR-Cas9 system was recently introduced into plants by transient or stable transformation. FINDINGS: Here, we report gene targeting in rice via the Agrobacterium tumefaciens-mediated CRISPR-Cas9 system. Three 20-nt CRISPR RNAs were designed to pair with diverse sites followed by the protospacer adjacent motif (PAM) of the rice herbicide resistance gene BEL. After integrating the single-guide RNA (sgRNA) and Cas9 cassette in a single binary vector, transgenic rice plants harboring sgRNA:Cas9 were generated by A. tumefaciens-mediated stable transformation. By analyzing the targeting site on the genome of corresponding transgenic plants, the mutations were determined. The mutagenesis efficiency was varied from ~2% to ~16%. Furthermore, phenotypic analysis revealed that the biallelic mutated transgenic plant was sensitive to bentazon. CONCLUSIONS: Our results indicate that the agricultural trait could be purposely modified by sgRNA:Cas9-induced gene targeting. CRISPR-Cas9 system could be exploited as a powerful tool for trait improvements in crop breeding. CRISPR/Cas9 systems are a versatile tool for genome editing due to the highly efficient targeting of DNA sequences complementary to their RNA guide strands. However, it has been shown that RNA-guided Cas9 nuclease cleaves genomic DNA sequences containing mismatches to the guide strand. A better understanding of the CRISPR/Cas9 specificity is needed to minimize off-target cleavage in large mammalian genomes. Here we show that genomic sites could be cleaved by CRISPR/Cas9 systems when DNA sequences contain insertions ('DNA bulge') or deletions ('RNA bulge') compared to the RNA guide strand, and Cas9 nickases used for paired nicking can also tolerate bulges in one of the guide strands. Variants of single-guide RNAs (sgRNAs) for four endogenous loci were used as model systems, and their cleavage activities were quantified at different positions with 1- to 5-bp bulges. We further investigated 114 putative genomic off-target loci of 27 different sgRNAs and confirmed 15 off-target sites, each harboring a single-base bulge and one to three mismatches to the guide strand. Our results strongly indicate the need to perform comprehensive off-target analysis related to DNA and sgRNA bulges in addition to base mismatches, and suggest specific guidelines for reducing potential off-target cleavage. Toxoplasma gondii has become a model for studying the phylum Apicomplexa, in part due to the availability of excellent genetic tools. Although reverse genetic tools are available in a few widely utilized laboratory strains, they rely on special genetic backgrounds that are not easily implemented in natural isolates. Recent progress in modifying CRISPR (clustered regularly interspaced short palindromic repeats), a system of DNA recognition used as a defense mechanism in bacteria and archaea, has led to extremely efficient gene disruption in a variety of organisms. Here we utilized a CRISPR/CAS9-based system with single guide RNAs to disrupt genes in T. gondii. CRISPR/CAS9 provided an extremely efficient system for targeted gene disruption and for site-specific insertion of selectable markers through homologous recombination. CRISPR/CAS9 also facilitated site-specific insertion in the absence of homology, thus increasing the utility of this approach over existing technology. We then tested whether CRISPR/CAS9 would enable efficient transformation of a natural isolate. Using CRISPR/CAS9, we were able to rapidly generate both rop18 knockouts and complemented lines in the type I GT1 strain, which has been used for forward genetic crosses but which remains refractory to reverse genetic approaches. Assessment of their phenotypes in vivo revealed that ROP18 contributed a greater proportion to acute pathogenesis in GT1 than in the laboratory type I RH strain. Thus, CRISPR/CAS9 extends reverse genetic techniques to diverse isolates of T. gondii, allowing exploration of a much wider spectrum of biological diversity. IMPORTANCE: Genetic approaches have proven very powerful for studying the biology of organisms, including microbes. However, ease of genetic manipulation varies widely among isolates, with common lab isolates often being the most amenable to such approaches. Unfortunately, such common lab isolates have also been passaged frequently in vitro and have thus lost many of the attributes of wild isolates, often affecting important traits, like virulence. On the other hand, wild isolates are often not amenable to standard genetic approaches, thus limiting inquiry about the genetic basis of biological diversity. Here we imported a new genetic system based on CRISPR/CAS9, which allows high efficiency of targeted gene disruption in natural isolates of T. gondii. This advance promises to bring the power of genetics to bear on the broad diversity of T. gondii strains that have been described recently. As a powerful genome-editing tool, the clustered regularly interspaced short palindromic repeats (CRISPR)-clustered regularly interspaced short palindromic repeats-associated protein 9 (Cas9) system has been quickly developed into a large-scale function-based screening strategy in mammalian cells. This new type of genetic library is constructed through the lentiviral delivery of single-guide RNA collections that direct Cas9 or inactive dead Cas9 fused with effectors to interrogate gene function or regulate gene transcription in targeted cells. Compared with RNA interference screening, the CRISPR-Cas9 system demonstrates much higher levels of effectiveness and reliability with respect to both loss-of-function and gain-of-function screening. Unlike the RNA interference strategy, a CRISPR-Cas9 library can target both protein-coding sequences and regulatory elements, including promoters, enhancers and elements transcribing microRNAs and long noncoding RNAs. This powerful genetic tool will undoubtedly accelerate the mechanistic discovery of various biological processes. In this mini review, we summarize the general procedure of CRISPR-Cas9 library mediated functional screening, system optimization strategies and applications of this new genetic toolkit. Engineered DNA-binding proteins that manipulate the human genome and transcriptome have enabled rapid advances in biomedical research. In particular, the RNA-guided CRISPR/Cas9 system has recently been engineered to create site-specific double-strand breaks for genome editing or to direct targeted transcriptional regulation. A unique capability of the CRISPR/Cas9 system is multiplex genome engineering by delivering a single Cas9 enzyme and two or more single guide RNAs (sgRNAs) targeted to distinct genomic sites. This approach can be used to simultaneously create multiple DNA breaks or to target multiple transcriptional activators to a single promoter for synergistic enhancement of gene induction. To address the need for uniform and sustained delivery of multiplex CRISPR/Cas9-based genome engineering tools, we developed a single lentiviral system to express a Cas9 variant, a reporter gene and up to four sgRNAs from independent RNA polymerase III promoters that are incorporated into the vector by a convenient Golden Gate cloning method. Each sgRNA is efficiently expressed and can mediate multiplex gene editing and sustained transcriptional activation in immortalized and primary human cells. This delivery system will be significant to enabling the potential of CRISPR/Cas9-based multiplex genome engineering in diverse cell types. Author information: (1)Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China. (2)Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua Fly Center, Tsinghua University, Beijing 100084, China; School of Basic Medical Sciences, Wuhan University, Wuhan 430071, China; College of Bioengineering, Hubei University of Technology, Wuhan 430068, China. (3)Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China; Sichuan Academy of Grassland Science, Chengdu 611731, China. (4)Department of Genetics, Harvard Medical School, Boston, MA 02115, USA. (5)Tsinghua Fly Center, Tsinghua University, Beijing 100084, China. (6)Department of Genetics, Stanford University, Stanford, CA 94305, USA. (7)Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China; Tsinghua Fly Center, Tsinghua University, Beijing 100084, China. (8)Department of Molecular and Cellular Medicine, College of Medicine, Texas A&M Health Science Center, College Station, TX 77843, USA. (9)Department of Genetics, Stanford University, Stanford, CA 94305, USA. Electronic address: [email protected]. (10)Gene Regulatory Lab, School of Medicine, Tsinghua University, Beijing 100084, China. Electronic address: [email protected].

What is the target protein of the drug Idelalisib?

Idelalisib represents a first-in-class specific inhibitor of the phosphoinositol-3 kinase (PI3K) delta isoform.

[24273091, 24060900, 23617253, 24261963, 24009233, 24085367, 23847354, 24323900, 24014301]

DISEASE OVERVIEW: Mantle cell lymphoma (MCL) is a non-Hodgkin lymphoma characterized by involvement of the lymph nodes, spleen, blood, and bone marrow with a short remission duration to standard therapies and a median overall survival of 4-5 years. DIAGNOSIS: Diagnosis is based on lymph node, bone marrow, or tissue morphology of centrocytic lymphocytes, small cell type, or blastoid variant cells. A chromosomal translocation t(11:14) is the molecular hallmark of MCL, resulting in the overexpression of cyclin D1. Cyclin D1 is detected by immunohistochemistry in 98% of cases. The absence of SOX-11 or a low Ki-67 may correlate with a more indolent form of MCL. The differential diagnosis of MCL includes small lymphocytic lymphoma, marginal zone lymphoma, and follicular lymphoma. RISK STRATIFICATION: The Mantle Cell Lymphoma International Prognostic Index (MIPI) is the prognostic model most often used and incorporates ECOG performance status, age, leukocyte count, and lactic dehydrogenase. A modification of the MIPI also adds the Ki-67 proliferative index if available. The median overall survival (OS) for the low risk group was not reached (5-year OS of 60%). The median OS for the intermediate risk group was 51 months and 29 months for the high risk group. RISK-ADAPTED THERAPY: For selected indolent, low MIPI MCL patients, initial observation may be appropriate therapy. For younger patients with intermediate or high risk MIPI MCL, aggressive therapy with a cytarabine containing regimen ± autologous stem cell transplantation should be considered. For older MCL patients with intermediate or high risk MIPI, combination chemotherapy with R-CHOP, R-Bendamustine, or a clinical trial should be considered. At the time of relapse, agents directed at activated pathways in MCL cells such as bortezomib (NFkB inhibitor) or lenalidamide (anti-angiogenesis) are approved agents. Clinical trials with Ibruitinib (Bruton's Tyrosine Kinase inhibitor) or Idelalisib (PI3K inhibitor) have demonstrated excellent clinical activity in MCL patients. Autologous or allogeneic stem cell transplantation can also be considered in young patients. The B-cell receptor (BCR) is essential for normal B-cell development and maturation. In an increasing number of B-cell malignancies, BCR signaling is implicated as a pivotal pathway in tumorigenesis. Mechanisms of BCR activation are quite diverse and range from chronic antigenic drive by microbial or viral antigens to autostimulation of B-cells by self-antigens to activating mutations in intracellular components of the BCR pathway. Hepatitis C virus infection can lead to the development of splenic marginal zone lymphoma, while Helicobacter pylori infection is associated with the development of mucosa-associated lymphoid tissue lymphomas. In some of these cases, successful treatment of the infection removes the inciting antigen and results in resolution of the lymphoma. Chronic lymphocytic leukemia has been recognized for decades as a malignancy of auto-reactive B-cells and its clinical course is in part determined by the differential response of the malignant cells to BCR activation. In a number of B-cell malignancies, activating mutations in signal transduction components of the BCR pathway have been identified; prominent examples are activated B-cell-like (ABC) diffuse large B-cell lymphomas (DLBCL) that carry mutations in CD79B and CARD11 and display chronic active BCR signaling resulting in constitutive activation of the NF-κB pathway. Despite considerable heterogeneity in biology and clinical course, many mature B-cell malignancies are highly sensitive to kinase inhibitors that disrupt BCR signaling. Thus, targeted therapy through inhibition of BCR signaling is emerging as a new treatment paradigm for many B-cell malignancies. Here, we review the role of the BCR in the pathogenesis of B-cell malignancies and summarize clinical results of the emerging class of kinase inhibitors that target this pathway. Normal B lymphocytes receive signals from B-cell antigen receptor (BCR) that are triggered by binding of the BCR to an external antigen. Tonic signaling through the BCR provides growth and signals to chronic lymphocytic leukemia (CLL) cells, and plays an important role in the pathogenesis and progression of the disease. Antigen engagement of BCR is followed by intracellular recruitment and activation of BCR-associated kinases including spleen tyrosine kinase (Syk), Bruton's tyrosine kinase (Btk) and phosphatidylinositol 3-kinases (PI3K). Inhibition of signaling pathways downstream of the BCR induces disruption of chemokine-mediated CLL cell migration and cell killing. BCR signal transduction inhibitors represent a promising new strategy for targeted CLL treatment. A number of therapeutic agents have recently been developed with significant activity in CLL. The compounds that are currently investigated in patients with CLL include ibrutinib -inhibitor of Btk, fostamatinib-inhibitor of Syk and idelalisib (GS-1101) -a specific isoform of the PI3K (PI3K) inhibitor. The clinical activity of ibrutinib, GS-1101 and fostamatinib in patients with CLL is associated with marked lymphocytosis due to release of tumor cells from the lymph nodes into the peripheral blood. Further studies are ongoing with single agents and their combinations with other targeted and conventional therapies. This article will review the preclinical rationale of BCR signaling inhibitors in the treatment of CLL, and the clinical evidence supporting the use of these agents in CLL patients. Phosphatidylinositol 3-kinases (PI3Ks) are lipid kinases that regulate diverse cellular processes including proliferation, adhesion, survival, and motility. Dysregulated PI3K pathway signaling occurs in one-third of human tumors. Aberrantly activated PI3K signaling also confers sensitivity and resistance to conventional therapies. PI3K has been recognized as an attractive molecular target for novel anti-cancer molecules. In the last few years, several classes of potent and selective small molecule PI3K inhibitors have been developed, and at least fifteen compounds have progressed into clinical trials as new anticancer drugs. Among these, idelalisib has advanced to phase III trials in patients with advanced indolent non-Hodgkin's lymphoma and mantle cell lymphoma. In this review, we summarized the major molecules of PI3K signaling pathway, and discussed the preclinical models and clinical trials of potent small-molecule PI3K inhibitors. Membrane antigens are critical to the pathogenesis of chronic lymphocytic leukemia (CLL) as they facilitate microenvironment homing, proliferation, and survival. Targeting the CLL membrane and associated signaling patterns is a current focus of therapeutic development. Many tumor membrane targets are simultaneously targeted by humoral immunity, thus forming recognizable immunoglobulin responses. We sought to use this immune response to identify novel membrane-associated targets for CLL. Using a novel strategy, we interrogated CLL membrane-specific autologous immunoglobulin G reactivity. Our analysis unveiled lymphocyte cytosolic protein 1 (LCP1), a lymphocyte-specific target that is highly expressed in CLL. LCP1 plays a critical role in B-cell biology by crosslinking F-actin filaments, thereby solidifying cytoskeletal structures and providing a scaffold for critical signaling pathways. Small interfering RNA knockdown of LCP1 blocked migration toward CXCL12 in transwell assays and to bone marrow in an in vivo xenotransplant model, confirming a role for LCP1 in leukemia migration. Furthermore, we demonstrate that the Bruton's tyrosine kinase inhibitor ibrutinib or the PI3K inhibitor idelalisib block B-cell receptor induced activation of LCP1. Our data demonstrate a novel strategy to identify cancer membrane target antigens using humoral anti-tumor immunity. In addition, we identify LCP1 as a membrane-associated target in CLL with confirmed pathogenic significance. This clinical trial was registered at clinicaltrials.gov; study ID number: OSU-0025 OSU-0156. Interactions between malignant B lymphocytes and the tissue microenvironment play a major role in the pathogenesis of chronic lymphocytic leukemia (CLL) and other B-cell malignancies. The coexistence and coevolution of CLL cells with their tissue neighbors provided the basis for discovery of critical cellular and molecular drivers of the disease and identification of new therapeutic targets. Bone marrow stromal cells (BMSC), monocyte-derived nurselike cells (NLC), and T cells are key players in the CLL microenvironment, which activate and protect CLL cells within the tissues. CLL surface molecules, such as the B-cell antigen receptor (BCR), chemokine receptors, adhesion molecules, and TNF receptor superfamily members (e.g., CD40, BCMA, and BAFF-R) engage in cross-talk with respective tissue ligands. This cross-talk results in survival and expansion of the CLL clone, and protects CLL cells from conventional cytotoxic drugs. Inhibiting these pathways represents an alternative therapeutic strategy to more conventional chemoimmunotherapy. Here, we review central components of the CLL microenvironment, with a particular emphasis on BCR signaling, and we summarize the most relevant clinical advances with inhibitors that target the BCR-associated spleen tyrosine kinase/SYK (fostamatinib), Bruton's tyrosine kinase/BTK (ibrutinib), and PI3Kδ (idelalisib). The B cell antigen receptor (BCR) and its downstream pathways are pivotal in the pathogenesis of chronic lymphocytic leukemia (CLL). Recently, inhibitors of kinases in the BCR pathway have shown promising clinical activity in CLL. Based upon these results, the treatment paradigm for CLL will likely undergo major changes. The kinases essential for BCR signal transduction, which are emerging as targets for CLL treatment, and the specific inhibitors under development are the focus of this chapter. In particular, the BTK inhibitor ibrutinib and the PI3K inhibitor idelalisib (GS-1101) are two evolving targeted therapies with the most mature clinical data.

Which antiepileptic drug is most strongly associated with spina bifida?

Phenytoin is not used in pregnancy as it is associated with a severe fetal deformation. From the other anticonvulsants most studies report the higher association between use during pregnancy and spin bifida to occur with Valproate.

[22051200, 2707392, 17075842, 3939491, 21766433, 23082254, 10339792, 11077457, 8075508, 19490036]

The teratogenicity of antiepilepsy drug valproic acid (VPA) mostly is found in genetic and somatic levels, causing teratogenesis involving neurotubular defects (NTDs), anencephaly, lumbosacral meningomyelocele, and leg dysfunction due to spina bifida aperta. A diversity of nutraceutics have been tried to alleviate the risk of VPA-teratogenicity. The effect was varying. In order to promote the preventive prescription, to find out its action mechanism can be rather crucial. We used chicken embryo model to try the effect of folic acid (FA), ascorbic acid (AA), and N-acetyl cysteine (NAC). VPA at 30mM showed the higher malformation rate (66.7%) with the least mortality (22.2%). Pathological findings indicated that the cervical muscle was more susceptible to VPA injury than the ankle muscle. VPA downregulated levels of superoxide dismutase (SOD), glutathione (GSH), histone deacetylase (HDAC) and folate, and upregulated H(2)O(2) and homocysteine. FA, AA, and NAC significantly upregulated SOD, but only AA alone activated GSH. AA and NAC downregulated H(2)O(2), while FA was totally ineffective. All three nutraceutics comparably rescued HDAC with simultaneously suppressed homocysteine accumulation and folate re-elevation, although less effectively by NAC. Based on these data, we conclude VPA possesses "Multiple Point Action Mechanism". In addition to affecting the cited transcription and translation levels, we hypothesize that VPA competitively antagonize the glutamic acid to couple with pteroic acid in biosynthesis of dihydrofolic acid (DHFA). H(2)O(2) directly destroyed the NADPH reducing system at dihydrofolate reductase (DHFR) and methylene tetrahydrofolate reductase (MTHFR) levels, while completely restored by AA, an implication in preservation of intact apoenzymes. In addition, the GSH-GSSG system is sandwiched between the reducing systems NADPH/NADP and DHA-AA, its net balance is highly dependent on in situ in vivo Redox state, hence folic acid transformation is varying. To rescue the VPA-induced teratogenicity, simultaneous multiple prescriptions are suggested. The distribution of anticonvulsant drug therapy was studied in 318 malformed infants with known histories of maternal epilepsy. Data on the infants was collected from six birth defect monitoring programs in Europe and South America. Use of specific types of anticonvulsants varies widely among reporting countries. Heterogeneity of drug-malformation distribution, was analyzed to determine whether use of specific drugs were linked to specific malformations. A significant association was seen between maternal use of valproic acid and spina bifida, and a weaker, non-significant one between carbamazepine and spina bifida. Facial clefts were associated with both diphenylhydantoin and phenobarbitone use and also with polytherapy. These differences indicate that the actual drug used is significant for the teratogenic process. The technique may be useful in analysis of other drug-related teratogenic questions. Valproic acid, a drug commonly used to treat seizures and other psychiatric disorders, causes neural tube defects (NTDs) in exposed fetuses at a rate 20 times higher than in the general population. Failure of the neural tube to close during development results in exencephaly or anencephaly, as well as spina bifida. In mice, nonspecific activation of the maternal immune system can reduce fetal abnormalities caused by diverse etiologies, including diabetes-induced NTDs. We hypothesized that nonspecific activation of the maternal immune system with interferon-gamma (IFN-gamma) and granulocyte-macrophage colony-stimulating factor (GM-CSF) could reduce valproic acid (VA)-induced defects as well. Female CD-1 mice were given immune stimulant prebreeding: either IFN-gamma or GM-CSF. Approximately half of the control and immune-stimulated pregnant females were then exposed to 500 mg/kg VA on the morning of gestational day 8. The incidence of developmental defects was determined on gestational day 17 from at least eight litters in each of the following treatment groups: control, VA only, IFN-gamma only, IFN-gamma+VA, GM-CSF only, and GM-CSF+VA. The incidence of NTDs was 18% in fetuses exposed to VA alone, compared to 3.7% and 2.9% in fetuses exposed to IFN-gamma+VA, or GM-CSF+VA respectively. Ocular defects were also significantly reduced from 28.0% in VA exposed groups to 9.8% in IFN-gamma+VA and 12.5% in GM-CSF+VA groups. The mechanisms by which maternal immune stimulation prevents birth defects remain unclear, but may involve maternal or fetal production of cytokines or growth factors which protect the fetus from the dysregulatory effects of teratogens. A case control study on the association between maternal epilepsy, anticonvulsants use during pregnancy and birth defects was carried out in the Italian Multicentric Registry of Birth Defects (IPIMC). In the period 1980-1983, 7,607 malformed babies out of 439,717 total births (still + live) were registered. Fourty-one malformed babies with maternal epilepsy were identified (5.39 X 1,000). The overall relative risk of having a malformed baby among pregnant epileptic women was 1.87. Spina Bifida, Congenital Heart Defects, Clefts, Diaphragmatic Hernia and Trisomy 18 were more frequent than expected among babies with maternal epilepsy. The different therapeutic regimens were also tested to identify the possible independent teratogenic effect of anticonvulsants. A statistically significant association between Spina Bifida and Valproic Acid (odds ratio 22.7; Fisher p value = 0.0364) was observed: no other anticonvulsant tested showed any association with any type of malformation. Selected antiepileptic drugs (AEDs) increase the risk of birth defects. To assess the impact of influencing AED prescribing practices on spina bifida and cleft palate we searched the literature for estimates of the association between valproic acid or carbamazepine use during pregnancy and these defects and summarized the associations using meta-analyses. We estimated distributions of the prevalence of valproic acid and carbamazepine use among women of childbearing age based on analyses of four data sets. We estimated the attributable fractions and the number of children born with each defect that could be prevented annually in the United States if valproic acid and carbamazepine were not used during pregnancy. The summary odds ratio estimate for the association between valproic acid and spina bifida was 11.9 (95% uncertainty interval (UI): 4.0-21.2); for valproic acid and cleft palate 5.8 (95% UI: 3.3-9.5); for carbamazepine and spina bifida 3.6 (95% UI: 1.3-7.8); and for carbamazepine and cleft palate 2.4 (95% UI: 1.1-4.5) in the United States. Approximately 40 infants (95% UI: 10-100) with spina bifida and 35 infants (95% UI: 10-70) with cleft palate could be born without these defects each year if valproic acid were not used during pregnancy; 5 infants (95% UI: 0-15) with spina bifida and 5 infants (95% UI: 0-15) with cleft palate could be born without these defects each year if carbamazepine were not used during pregnancy. This modeling approach could be extended to other medications to estimate the impact of translating pharmacoepidemiologic data to evidence-based prenatal care practice. Fetal hydantoin syndrome is a rare disorder that is believed to be caused by exposure of a fetus to the anticonvulsant drug phenytoin. The classic features of fetal hydantoin syndrome include craniofacial anomalies, prenatal and postnatal growth deficiencies, underdeveloped nails of the fingers and toes, and mental retardation. Less frequently observed anomalies include cleft lip and palate, microcephaly, ocular defects, cardiovascular anomalies, hypospadias, umbilical and inguinal hernias, and significant developmental delays. Anaesthesia for incidental surgery in such a patient poses unique challenges for the anesthesiologist. We report the successful management of a 4-year-old male child with fetal hydantoin syndrome, cleft palate, spina bifida, atrial septal defect, and dextrocardia for tibialis anterior lengthening under subarachnoid block. PURPOSE: The study goal was to assess teratogenic effects of antiepileptic drugs (AEDs) through the use of a surveillance system (MADRE) of infants with malformations. METHODS: Information on all malformed infants (1990-1996) with maternal first-trimester drug exposure was collected by the International Clearinghouse for Birth Defects and Monitoring Systems (ICBDMS). Cases were defined as infants presenting with a specific malformation, and controls were defined as infants presenting with any other birth defect. Exposure was defined by the use of AEDs during the first trimester of pregnancy. The association of AEDs with malformations was then estimated by calculating the odds ratios with 95% confidence intervals and testing their homogeneity among registries. RESULTS: Among 8005 cases of malformations, 299 infants were exposed in utero to AEDs. Of those exposed to monotherapy, 65 were exposed to phenobarbital, 10 to methylphenobarbital, 80 to valproic acid, 46 to carbamazepine, 24 to phenytoin, and 16 to other AEDs. Associations were found for spina bifida with valproic acid. Infants exposed to phenobarbital and to methylphenobarbital showed an increased risk of oral clefts. Cardiac malformations were found to be associated with phenobarbital, methylphenobarbital, valproic acid, and carbamazepine. Hypospadias was associated with valproic acid. Porencephaly and other specified anomalies of brain, anomalies of face, coarctation of aorta, and limb reduction defects were found to be associated with valproic acid. CONCLUSIONS: Using the MADRE system, we confirmed known teratogenic effects of AEDs. We also found increased risks for malformations that had never been reported associated with AEDs or for which the association was suggested by case reports. Women with epilepsy giving birth during 1973 to 1991 were identified by record linkage of Swedish health registries. Among 3,625 identified infants, 9 had spina bifida. A nested case-control study was performed, comparing drugs used in early pregnancy in the 9 cases and in 18 controls, matched for year of delivery, maternal age, and parity. Six of the spina bifida mothers had used carbamazepine and two had used valproic acid. Among the controls, 5 women used carbamazepine and one valproic acid. There is an apparent excess risk for spina bifida after use of either of these two drugs, but it is not statistically significant when the analysis is restricted to drug-using women. The findings support earlier reports in the literature of an association between carbamazepine and spina bifida. PURPOSE: To investigate pregnancy, delivery, and child outcome in an unselected population of women with both treated and untreated epilepsy. METHODS: In the compulsory Medical Birth Registry of Norway, all 2,861 deliveries by women with epilepsy recorded from 1999-2005 were compared to all 369,267 nonepilepsy deliveries in the same period. RESULTS: The majority (66%, n = 1900) in the epilepsy group did not use antiepileptic drugs (AEDs) during pregnancy. A total of 961 epilepsy-pregnancies were exposed to AEDs. Compared to nonepilepsy controls, AED-exposed infants were more often preterm (p = 0.01), and more often had birth weight <2,500 g (p < 0.001), head circumference <2.5 percentile (p < 0.001), and low Apgar score (p = 0.03). Small-for-gestational-age (SGA) infants (<10 percentile) occurred more frequently in both AED-exposed (p = 0.05) and unexposed (p = 0.02) epilepsy-pregnancies. Frequency of major congenital malformations (MCMs) was 2.8% (n = 81) in the epilepsy group versus 2.5% in controls (p = 0.3). Increased risk for MCMs could be demonstrated only for exposure to valproate (5.6%, p = 0.005) and AED polytherapy (6.1%, p = 0.02). Neonatal spina bifida was not significantly increased, but was a major indication for elective pregnancy termination among women with epilepsy. Cesarean section was performed more often in maternal epilepsy, regardless of AED-exposure (p < 0.001). DISCUSSION: Adverse pregnancy and birth outcome in women with epilepsy is mainly confined to AED-exposed pregnancies, although some risks are associated also with untreated epilepsy. The risk for congenital malformations was lower than previously reported. This could be due to a shift in AED selection, folic acid supplement, or possibly reflect the true risks in an unselected epilepsy population.

Which bacteria caused plague?

Yersinia pestis is the causative bacteria of the plague.

[8052312, 16410352]

Protein tyrosine phosphatases (PTPases) and kinases coregulate the critical levels of phosphorylation necessary for intracellular signalling, cell growth and differentiation. Yersinia, the causative bacteria of the bubonic plague and other enteric diseases, secrete an active PTPase, Yop51, that enters and suppresses host immune cells. Though the catalytic domain is only approximately 20% identical to human PTP1B, the Yersinia PTPase contains all of the invariant residues present in eukaryotic PTPases, including the nucleophilic Cys 403 which forms a phosphocysteine intermediate during catalysis. We present here structures of the unliganded (2.5 A resolution) and tungstate-bound (2.6 A) crystal forms which reveal that Cys 403 is positioned at the centre of a distinctive phosphate-binding loop. This loop is at the hub of several hydrogen-bond arrays that not only stabilize a bound oxyanion, but may activate Cys 403 as a reactive thiolate. Binding of tungstate triggers a conformational change that traps the oxyanion and swings Asp 356, an important catalytic residue, by approximately 6 A into the active site. The same anion-binding loop in PTPases is also found in the enzyme rhodanese. Plague is still an endemic disease in different regions of the world. Increasing reports of incidence, the discovery of antibiotic resistance strains, and concern about a potential use of the causative bacteria Yersinia pestis as an agent of biological warfare have highlighted the need for a safe, efficacious, and rapidly producible vaccine. The use of F1 and V antigens and the derived protein fusion F1-V has shown great potential as a protective vaccine in animal studies. Plants have been extensively studied for the production of pharmaceutical proteins as an inexpensive and scalable alternative to common expression systems. In the current study the recombinant plague antigens F1, V, and fusion protein F1-V were produced by transient expression in Nicotiana benthamiana by using a deconstructed tobacco mosaic virus-based system that allowed very rapid and extremely high levels of expression. All of the plant-derived purified antigens, administered s.c. to guinea pigs, generated systemic immune responses and provided protection against an aerosol challenge of virulent Y. pestis.

The drug JTV519 is derivative of which group of chemical compounds?

The 1,4-benzothiazepine derivative JTV-519 is a new type of calcium ion channel modulator.JTV-519, which has potential use as an antiarrhythmic [285800]. The drug is a novel cardioprotectant derivative of 1,4-benzothiazepine for which phase I trials were completed in the third quarter of 1998

[23349825, 11757794, 15073377, 12551874, 21989257, 22509897, 10789707, 11101196, 10864882, 11429046, 17112502, 12433661, 10683355, 17313373, 12359358]

Activation of the skeletal muscle ryanodine receptor (RyR1) complex results in the rapid release of Ca(2+) from the sarcoplasmic reticulum and muscle contraction. Dissociation of the small FK506 binding protein 12 subunit (FKBP12) increases RyR1 activity and impairs muscle function. The 1,4-benzothiazepine derivative JTV519, and the more specific derivative S107 (2,3,4,5,-tetrahydro-7-methoxy-4-methyl-1,4-benzothiazepine), are thought to improve skeletal muscle function by stabilizing the RyR1-FKBP12 complex. Here, we report a high degree of nonspecific and specific low affinity [(3)H]S107 binding to SR vesicles. SR vesicles enriched in RyR1 bound ∼48 [(3)H]S107 per RyR1 tetramer with EC(50) ∼52 µM and Hillslope ∼2. The effects of S107 and FKBP12 on RyR1 were examined under conditions that altered the redox state of RyR1. S107 increased FKBP12 binding to RyR1 in SR vesicles in the presence of reduced glutathione and the NO-donor NOC12, with no effect in the presence of oxidized glutathione. Addition of 0.15 µM FKBP12 to SR vesicles prevented FKBP12 dissociation; however, in the presence of oxidized glutathione and NOC12, FKBP12 dissociation was observed in skeletal muscle homogenates that contained 0.43 µM myoplasmic FKBP12 and was attenuated by S107. In single channel measurements with FKBP12-depleted RyR1s, in the absence and presence of NOC12, S107 augmented the FKBP12-mediated decrease in channel activity. The data suggest that S107 can reverse the harmful effects of redox active species on SR Ca(2+) release in skeletal muscle by binding to RyR1 low affinity sites. Ventricular arrhythmias can cause sudden cardiac death (SCD) in patients with normal hearts and in those with underlying disease such as heart failure. In animals with heart failure and in patients with inherited forms of exercise-induced SCD, depletion of the channel-stabilizing protein calstabin2 (FKBP12.6) from the ryanodine receptor-calcium release channel (RyR2) complex causes an intracellular Ca2+ leak that can trigger fatal cardiac arrhythmias. A derivative of 1,4-benzothiazepine (JTV519) increased the affinity of calstabin2 for RyR2, which stabilized the closed state of RyR2 and prevented the Ca2+ leak that triggers arrhythmias. Thus, enhancing the binding of calstabin2 to RyR2 may be a therapeutic strategy for common ventricular arrhythmias. BACKGROUND: JTV519 is know to protect cardiomyocytes from calcium overloading-induced damage. The aim of this study was to investigate the potential protective effect of JTV519 on myocardium subjected to prolonged ischemia and the underlying mechanism of such protection. The effect of JTV519 was also compared with that of diltiazem, a 1,5-benzothiazepine derivative. METHODS: Isolated rat hearts were randomly divided into three groups. Control hearts were arrested with histidine-tryptophan-ketoglutarat (HTK) cardioplegic solution alone. In the JTV519 group of hearts, cardiac arrest was achieved with JTV519 (10(-3) mmol/L) in the HTK solution. Hearts in the diltiazem group were arrested with diltiazem (0.5 mmol/L) in the HTK solution. All the hearts were then subjected to 6-hour storage in HTK solution at 4 degrees C. RESULTS: After a 30-minute reperfusion, the left ventricular developed pressure in the JTV519 and diltiazem groups were improved significantly compared with the control group. There was a significantly lower left ventricular end-diastolic pressure level and higher recovery of coronary flow in the JTV519 group than in the control group. The postischemic intracellular calcium concentration was attenuated by adding JTV519 or diltiazem to HTK cardioplegia. CONCLUSION: As an adjunct to cardioplegia, JTV519 showed a significant protective effect on myocardium undergoing 6 hours of ischemia. The beneficial protective effects of JTV519 are correlated with its ability to inhibit the postischemic rise in intracellular calcium. A new 1,4-benzothiazepine derivative, JTV519 (JTV), has strong protective effects against isoproterenol-induced myocardial injury. We investigated the effects of JTV on Ca2+ overload and on functional recovery during ischemia/reperfusion in isolated coronary-perfused rat hearts. After 30 minutes of reperfusion following 30 min of global ischemia, the % recovery of LV developed pressure was improved in a concentration-dependent manner when JTV (0.3-3.0 microM) was administered either 5 min before induction of ischemia or for 5 min at the time of reperfusion only JTV showed a negative inotropic effect only at concentrations above 3.0 microM. In indol-loaded isolated heart preparations, 0.3 microM JTV did not affect the preischemic systolic or diastolic Ca2+ levels of the Ca2+ transient as measured by the ratio of 2-wavelength fluormetry (R405/500). In contrast, it significantly reduced the increase in the ratio in the postischemic reperfusion period (% change of R405/500 from baseline: JTV(-), by 42.7 +/- 3.2%; JTV(+), by 18.4 +/- 9.1%, p < 0.05). In isolated rat ventricular myocytes with a standard patch-clamp method, we further tested the interaction of JTV with the L-type Ca2+ channel (I(Ca)). The % inhibition of the peak current of I(Ca) was 6.2 +/- 0.8% at 0.3 microM (p = n.s.), 22.0 +/- 3.3% at 1.0 microM (p < 0.05), and 59.6 +/- 1.4% at 3.0 microM (p < 0.01). Thus, the marked cardioprotection due to JTV at 0.3 microM may not be solely attributed to its inhibitory effect on the transsarcolemmal Ca2+ influx through I(Ca). In conclusion, JTV519 is a novel pharmacological agent that has been demonstrated for the first time to have clinical potential for the treatment of acute coronary syndrome by its efficacy in administration at the time of reperfusion, by its suppression of reperfusion-related intracellular Ca2+ overload with no significant interaction with I(Ca), and by its subsequent ability of strong myocardial protection. The 1,4-benzothiazepine derivative JTV-519 is a new type of calcium ion channel modulator. We examined the modulatory effect of JTV-519 on the antitumor activity of several platinum compounds (cisplatin, carboplatin, and nedaplatin) in a human cancer cell line resistant to cisplatin (PC-14 / CDDP) in vitro. PC-14 / CDDP cells showed 8-fold resistance to cisplatin compared with the parental PC-14 cells as determined by dye formation [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT] assay. In PC-14 / CDDP, but not PC-14 cells, augmentation of cytotoxicity was observed when a nontoxic concentration (10 mM) of JTV-519 was combined with the platinum compounds. Increased intracellular cisplatin accumulation was observed in PC-14 / CDDP cells in the presence of JTV-519 as measured by atomic absorption assay. Therefore, increased cisplatin accumulation was considered to be a possible mechanism underlying the reversing effect of JTV-519 on cisplatin resistance. These results suggest that JTV-519 is a potent agent reversing cisplatin resistance. K201 (JTV519) is a 1,4-benzothiazepine derivative that exhibits a strong cardioprotective action and acts as a multiple-channel blocker, including as a K+ channel blocker. An experimental model of prolongation of the QT interval and torsades de pointes can be induced in rabbits by treatment with clofilium in the presence of the alpha1-adrenoreceptor agonist methoxamine. In this study we examined the effects of K201 with and without methoxamine on the QT and QTc intervals, and determined whether K201 inhibits clofilium-induced torsades de pointes in the presence of methoxamine (15 microg/kg/min) in rabbits (n=74). Administration of K201 (0, 40, 100, 200 and 400 microg/kg/min) with and without methoxamine prolonged the QT interval in a dose-dependent manner, and torsades de pointes did not occur in any animals. However, clofilium (50 microg/kg/min) with methoxamine induced torsades de pointes in all animals (6/6). Torsades de pointes occurred at rates of 100%, 67%, 40% and 0% at K201 concentrations of 0, 50, 200 and 400 microg/kg/min, respectively, in the clofilium-infused torsades de pointes model. Therefore, 400 microg/kg/min of K201 completely inhibited clofilium-induced torsades de pointes and attenuated the increase of repolarization caused by clofilium; the inhibitory effects of K201 may be related to its pharmacological properties as an alpha1-adrenoceptor blocker. Overall, our results show that K201 causes prolongation of the QT and QTc intervals, but does not induce torsades de pointes, with and without alpha1-adrenoceptor stimulation. Furthermore, K201 inhibits clofilium-induced torsades de pointes, despite QT prolongation, suggesting that QT prolongation alone is not a proarrhythmic signal. BACKGROUND: A new 1,4-benzothiazepine derivative, JTV519, has a strong protective effect against Ca(2+) overload-induced myocardial injury. We investigated the effect of JTV519 on ischemia/reperfusion injury in isolated rat hearts. METHODS AND RESULTS: At 30 minutes of reperfusion after 30-minute global ischemia, the percent recovery of left ventricular developed pressure was improved, and the creatine phosphokinase and lactate dehydrogenase leakage was reduced in a concentration-dependent manner when JTV519 was administered in the coronary perfusate both at 5 minutes before the induction of ischemia and at the time of reperfusion. The myocardial protective effect of JTV519 was completely blocked by pretreatment of the heart with GF109203X, a specific protein kinase C (PKC) inhibitor. In contrast, the effect of JTV519 was not affected by alpha(1)-, A(1)-, and B(2)-receptor blockers that couple with PKC in the cardiomyocyte. Both immunofluorescence images and immunoblots of JTV519-treated left ventricular myocardium and isolated ventricular myocytes demonstrated that this agent induced concentration-dependent translocation of the delta-isoform but not the other isoforms of PKC to the plasma membrane. CONCLUSIONS: The mechanism of cardioprotection by JTV519 against ischemia/reperfusion injury involves isozyme-specific PKC activation through a receptor-independent mechanism. This agent may provide a novel pharmacological approach for the treatment of patients with acute coronary diseases via a subcellular mechanism mimicking ischemic preconditioning. K201 (JTV519), a benzothiazepine derivative, has been shown to possess anti-arrhythmic and cardioprotective properties, but the mechanism of its action is both complex and controversial. It is believed to stabilize the closed state of the RyR2 (cardiac ryanodine receptor) by increasing its affinity for the FKBP12.6 (12.6 kDa FK506 binding protein) [Wehrens, Lehnart, Reiken, Deng, Vest, Cervantes, Coromilas, Landry and Marks (2004) Science 304, 292-296]. In the present study, we investigated the effect of K201 on spontaneous Ca2+ release induced by Ca2+ overload in rat ventricular myocytes and in HEK-293 cells (human embryonic kidney cells) expressing RyR2 and the role of FKBP12.6 in the action of K201. We found that K201 abolished spontaneous Ca2+ release in cardiac myocytes in a concentration-dependent manner. Treating ventricular myocytes with FK506 to dissociate FKBP12.6 from RyR2 did not affect the suppression of spontaneous Ca2+ release by K201. Similarly, K201 was able to suppress spontaneous Ca2+ release in FK506-treated HEK-293 cells co-expressing RyR2 and FKBP12.6. Furthermore, K201 suppressed spontaneous Ca2+ release in HEK-293 cells expressing RyR2 alone and in cells co-expressing RyR2 and FKBP12.6 with the same potency. In addition, K201 inhibited [3H]ryanodine binding to RyR2-wt (wild-type) and an RyR2 mutant linked to ventricular tachycardia and sudden death, N4104K, in the absence of FKBP12.6. These observations demonstrate that FKBP12.6 is not involved in the inhibitory action of K201 on spontaneous Ca2+ release. Our results also suggest that suppression of spontaneous Ca2+ release and the activity of RyR2 contributes, at least in part, to the anti-arrhythmic properties of K201. A newly synthesized 1,4-benzothiazipine derivate, 4-[3-(4-benzylpiperidin-1-yl) propionyl]-7-methoxy-2,3,4,5-tetrahydro-1, 4-benzothiazepine monohydrochloride (JTV-519) was examined for its ability to reverse P-glycoprotein (P-gp) and multidrug resistance protein 1 (MRP1) mediated multidrug resistance (MDR) in K562/MDR and KB/MRP cells, respectively. JTV-519 at 3 microM reversed the resistance of K562/MDR cells to vincristine (VCR), taxol, etoposide (VP16), adriamycin (ADM) and actinomycin D and at 0.5 or 1 microM reversed their resistance to STI571. JTV-519 at 10 microM enhanced the accumulation of ADM in K562/MDR cells to the level in parental K562 cells and inhibited the efflux of ADM from K562/MDR cells. Photoaffinity labeling of P-gp with 3H-azidopine was almost completely inhibited by 500 microM JTV-519. JTV-519 at 3 microM also partially reversed the resistance of KB/MRP cells to VCR and at 500 microM partially inhibited the photoaffinity labeling of MRP1 with (125)I-II-azidophenyl agosterol A (125I-azidoAG-A). These results suggest that JTV-519 reversed the resistance to the anti-cancer agents in P-gp and MRP1 overexpressing multidrug-resistant cells by directly binding to P-gp and MRP1, and competitively inhibiting transport of the anti-cancer agents.

Is the long non- coding RNA malat-1 up or downregulated in cancer?

Malat-1 expression is upregulated in several tumor types

[21266177, 16878148, 24163781, 22722759, 21678027, 16441420, 18006640, 23845456, 23104528, 22858678, 23726266, 15552795, 22088988, 12970751]

RNA processing is vital for the high fidelity and diversity of eukaryotic transcriptomes and the encoded proteomes. However, control of RNA processing is not fully established. Σ RNA is a class of conserved large non-coding RNAs (murine Hepcarcin; human MALAT-1) up-regulated in carcinomas. Using antisense technology, we identified that RNA post-transcriptional modification is the most significant global function of Σ RNA. Specifically, processing of the pre-mRNAs of genes including Tissue Factor and Endoglin was altered by hydrolysis of Σ RNA/MALAT-1. These results support the hypothesis that Σ RNA/MALAT-1 is a regulatory molecule exerting roles in RNA post-transcriptional modification. Although metastasis-associated lung adenocarcinoma transcript (MALAT)-1 is known to be consistently upregulated in several epithelial malignancies, little is known about its function or regulation. We therefore examined the relationship between MALAT-1 expression and candidate modulators such as DNA tumor virus oncoproteins human papillomavirus (HPV)-16 E6 and E7, BK virus T antigen (BKVTAg), mouse polyoma virus middle T antigen (MPVmTAg) and tumor suppressor genes p53 and pRb. Using suppressive subtractive hybridization (SSH) and real-time reverse transcriptase polymerase chain reaction (RT-PCR) assays, MALAT-1 was shown to be increased in viral oncongene-expressing salivary gland biopsies from humans and mice. The results also indicated that MALAT-1 transcripts and promoter activity were increased in vitro when viral oncongene-expressing plasmids were introduced into different cell types. These same viral oncogenes in addition to increasing MALAT-1 transcription have also been shown to inhibit p53 and/or pRb function. In p53 mutant or inactive cell lines MALAT-1 was also shown to be highly upregulated. We hypothesize that there is a correlation between MALAT-1 over-expression and p53 deregulation. In conclusion, we show that disruption of p53, by both polyoma and papilloma oncoproteins appear to play an important role in the up-regulation of MALAT-1. MALAT-1 might therefore represent a biomarker for p53 deregulation within malignancies. Recent studies reveal that long non-coding RNAs (lncRNAs) have been shown to have important regulatory roles in cancer biology, and lncRNA MALAT-1 expression is upregulated in some tumors. However, the contributions of MALAT-1 to bladder cancer metastasis remain largely unknown. In the present study we evaluated MALAT-1 expression in bladder cancer tissues by real-time PCR, and defined its biological functions. We verified that MALAT-1 levels were upregulated in bladder cancer tissues compared with adjacent normal tissues, and MALAT-1 expression was remarkably increased in primary tumors that subsequently metastasized, when compared to those primary tumors that did not metastasize. SiRNA-mediated MALAT-1 silencing impaired in vitro bladder cancer cell migration. Downregulation of MALAT-1 resulted in a decrease of the epithelial-mesenchymal transition (EMT)-associated ZEB1, ZEB2 and Slug levels, and an increase of E-cadherin levels. We further demonstrated that MALAT-1 promoted EMT by activating Wnt signaling in vitro. These data suggest an important role for MALAT-1 in regulating metastasis of bladder cancer and the potential application of MALAT-1 in bladder cancer therapy. Metastasis-associated lung adenocarcinoma transcript 1(MALAT1), a long non-coding RNA (lncRNA), is up-regulated in many solid tumors and associated with cancer metastasis and recurrence. However, its role in hepatocellular carcinoma (HCC) remains poorly understood. In the present study, we evaluated the expression of MALAT1 by quantitative real-time PCR in 9 liver cancer cell lines and 112 HCC cases including 60 cases who received liver transplantation (LT) with complete follow-up data. Moreover, small interfering RNA (siRNA) was used to inhibit MALAT1 expression to investigate its biological role in tumor progression. We found that MALAT1 was up-regulated in both cell lines and clinical tissue samples. Patients with high expression level of MALAT1 had a significantly increased risk of tumor recurrence after LT, particularly in patients who exceeded the Milan criteria. On multivariate analysis, MALAT1 was an independent prognostic factor for predicting HCC recurrence (hazard ratio, 3.280, P = 0.003).In addition, inhibition of MALAT1 in HepG2 cells could effectively reduce cell viability, motility, invasiveness, and increase the sensitivity to apoptosis. Our data suggest that lncRNA MALAT1 play an important role in tumor progression and could be a novel biomarker for predicting tumor recurrence after LT and serve as a promising therapeutic target. Endometrial stromal sarcoma (ESS) of the uterus is a rare uterine malignancy that has not been characterized in detail. To characterize the phenotype of ESS of the uterus, we extracted RNA from ESS and the stroma of normal endometrium using a tissue microdissection system and compared the expression profiles in the two tissues. After suppression subtractive hybridization and differential screening, we detected the metastasis-associated lung adenocarcinoma transcript 1 (MALAT-1) gene as one of the major genes upregulated in ESS, and a full-length placental cDNA clone (CS0DI066YJ10) as one of the major genes downregulated. The results were confirmed by in situ hybridization in four resected specimens of ESS and 36 biopsy specimens of normal endometrial tissue. All ESS (4/4) and all cases of endometrial stromal cells in the proliferative phase (13/13) were positive for MALAT-1, but samples of normal stroma in the secretory phase and menopausal state included some that were negative or weakly positive for MALAT-1 (5/13 and 3/10, respectively). In contrast, all ESS and 12 of 13 cases of stromal cells in the proliferative phase were negative for the full-length placental cDNA clone but 10 of 13 cases of endometrial stromal cells in the secretory phase were positive for transcripts of the gene (P < 0.05). These results indicated that endometrial stromal cells have different phenotypic characteristics between proliferative and secretory phases and the tumor cells of ESS have the phenotypic character of endometrial stromal cells in the proliferative phase. Recent studies with tiling arrays have revealed more genomic transcription than previously anticipated. Whole new groups of non-coding transcripts (NCTs) have been detected. Some of these NCTs, including miRNAs, can regulate gene expression. To date, most known NCTs studied have been relatively short, but several important regulatory NCTs, including XIST, MALAT-1, BC1 and BC200, are considerably larger in length and represent a novel class of long, non-coding RNA species. Whole-genome tiling arrays were utilized to identify novel long NCTs across the entire human genome. Our results have identified a new group of long (>400 nt), abundantly expressed NCTs and have found that a subset of these are also highly evolutionarily conserved. In this report, we have begun to characterize 15 long, conserved NCTs. Quantitative real-time RT-PCR was used to analyze their expression in different normal human tissue and also in breast and ovarian cancers. We found altered expression of many of these NCTs in both cancer types. In addition, several of these NCTs have consistent mutations when sequences of normal samples were compared with a panel of cancer-derived cell lines. One NCT was found to be consistently mutated in a panel of endometrial cancers compared with matched normal blood. These NCTs were among the most abundantly expressed transcripts detected. There are probably many long, conserved NCTs, albeit with lower levels of expression. Although the function of these NCTs is currently unknown, our study indicates that they may play an important function in both normal cells and in cancer development. 1. The metastasis-associated lung adenocarcinoma transcript 1, MALAT1, is a long non-coding RNA (lncRNA) that has been discovered as a marker for lung cancer metastasis. It is highly abundant, its expression is strongly regulated in many tumor entities including lung adenocarcinoma and hepatocellular carcinoma as well as physiological processes, and it is associated with many RNA binding proteins and highly conserved throughout evolution. The nuclear transcript MALAT-1 has been functionally associated with gene regulation and alternative splicing and its regulation has been shown to impact proliferation, apoptosis, migration and invasion. Here, we have developed a human and a mouse knockout system to study the loss-of-function phenotypes of this important ncRNA. In human tumor cells, MALAT1 expression was abrogated using Zinc Finger Nucleases. Unexpectedly, the quantitative loss of MALAT1 did neither affect proliferation nor cell cycle progression nor nuclear architecture in human lung or liver cancer cells. Moreover, genetic loss of Malat1 in a knockout mouse model did not give rise to any obvious phenotype or histological abnormalities in Malat1-null compared with wild-type animals. Thus, loss of the abundant nuclear long ncRNA MALAT1 is compatible with cell viability and normal development. Examining plasma RNA is an emerging non-invasive diagnosis technique. However, whether tumour-derived long non-coding RNAs (lncRNAs) in plasma can be used as a novel approach to detect human prostate cancer (PCa) has not yet been established. The study was divided into three parts: (1) the characteristics of PCa-related lncRNA fragments were systematically studied in the plasma or serum of 25 patients; (2) the source of the circulating lncRNA fragments was explored in vitro and in vivo; and (3) the diagnostic performance of metastasis associated in lung adenocarcinoma transcript 1 (MALAT-1) derived (MD) miniRNA was validated in an independent cohort of 192 patients. The expression levels of lncRNAs were measured by quantitative real time polymerase chain reaction (qRT-PCR). The MD-miniRNA copies were calculated using a standard curve in an area under the ROC curve (AUC)-receiver operating characteristic (ROC) analysis. Genome-wide profiling revealed that MALAT-1 and prostate cancer gene 3 (PCA3) are overexpressed in PCa tissues. Plasma lncRNAs probably exist in the form of fragments in a stable form. MD-miniRNA enters cell culture medium at measurable levels, and MD-miniRNA derived from human PCa xenografts actually enters the circulation in vivo and can be measured to distinguish xenografted mice from controls. In addition, plasma MD-miniRNA levels are significantly elevated in PCa patients compared to non-PCa patients (p<0.001). At a cut-off of 867.8 MD-miniRNA copies per microlitre of plasma, the sensitivity is 58.6%, 58.6% and 43.5% and the specificity is 84.8%, 84.8% and 81.6% for discriminating PCa from non-PCa, positive biopsy from negative biopsy and positive biopsy from negative biopsy, respectively. We conclude that MD-miniRNA can be used as a novel plasma-based biomarker for PCa detection and can improve diagnostic accuracy by predicting prostate biopsy outcomes. Further large-scale studies are needed to confirm our findings. In early-stage non-small-cell lung cancer (NSCLC), a substantial proportion of patients can be cured by surgery. Development of distant metastases is the most frequent cause of therapeutic failure. The possibility to accurately predict a patient's risk for developing distant metastasis would help to identify patients that are candidates for further intervention such as conventional adjuvant chemotherapy or experimental drugs. Current molecular biology techniques allow the genome-wide screening for differentially expressed genes; and adequate bioinformatics approaches are developed at a rapid pace to improve prognosis prediction. Genes associated with metastasis do not necessarily play a role in disease pathogenesis but rather reflect the activation of specific signal-transduction pathways that are associated with enhanced migration and invasion capability. In our own work, we have identified several genes (e.g. thymosin beta-4, elF4A1), including a novel non-coding RNA (MALAT-1) to be expressed at significantly higher levels in stage-I and stage-II NSCLC primary tumours that subsequently metastasised. As a consequence, patients with high-level expression of these genes were shown to have significantly worse survival compared to patients with low-level expression of these genes. These data support the hypothesis that gene-expression patterns in primary tumours determine the tumours' likelihood to metastasise. In the near future, this information will be used for tailored therapy approaches for patients with early-stage NSCLC. INTRODUCTION: The functions of large noncoding RNAs (ncRNAs) have remained elusive in many cases. Metastasis-Associated-in-Lung-Adenocarcinoma-Transcript-1 (MALAT-1) is an ncRNA that is highly expressed in several tumor types. METHODS: Overexpression and RNA interference (RNAi) approaches were used for the analysis of the biological functions of MALAT-1 RNA. Tumor growth was studied in nude mice. For prognostic analysis, MALAT-1 RNA was detected on paraffin-embedded non-small cell lung cancer (NSCLC) tissue probes (n = 352) using in situ hybridization. RESULTS: MALAT-1 was highly expressed in several human NSCLC cell lines. MALAT-1 expression was regulated by an endogenous negative feedback loop. In A549 NSCLCs, RNAi-mediated suppression of MALAT-1 RNA suppressed migration and clonogenic growth. Forced expression of MALAT-1 in NIH 3T3 cells significantly increased migration. Upon injection into nude mice, NSCLC xenografts with decreased MALAT-1 expression were impaired in tumor formation and growth. In situ hybridization on paraffin-embedded lung cancer tissue probes revealed that high MALAT-1 RNA expression in squamous cell carcinoma of the lung was associated with a poor prognosis. On genetic level, MALAT-1 displays the strongest association with genes involved in cancer like cellular growth, movement, proliferation, signaling, and immune regulation. CONCLUSIONS: These data indicate that MALAT-1 expression levels are associated with patient survival and identify tumor-promoting functions of MALAT-1.

Oxantel is used for periodontitis treatment. How does it work?

Oxantel, a cholinergic anthelmintic and fumarate reductase inhibitor, significantly inhibited biofilm formation by P. gingivalis and disrupted established biofilms.

[20038616, 24165189]

Bacterial pathogens commonly associated with chronic periodontitis are the spirochete Treponema denticola and the Gram-negative, proteolytic species Porphyromonas gingivalis and Tannerella forsythia. These species rely on complex anaerobic respiration of amino acids, and the anthelmintic drug oxantel has been shown to inhibit fumarate reductase (Frd) activity in some pathogenic bacteria and inhibit P. gingivalis homotypic biofilm formation. Here, we demonstrate that oxantel inhibited P. gingivalis Frd activity with a 50% inhibitory concentration (IC50) of 2.2 μM and planktonic growth of T. forsythia with a MIC of 295 μM, but it had no effect on the growth of T. denticola. Oxantel treatment caused the downregulation of six P. gingivalis gene products and the upregulation of 22 gene products. All of these genes are part of a regulon controlled by heme availability. There was no large-scale change in the expression of genes encoding metabolic enzymes, indicating that P. gingivalis may be unable to overcome Frd inhibition. Oxantel disrupted the development of polymicrobial biofilms composed of P. gingivalis, T. forsythia, and T. denticola in a concentration-dependent manner. In these biofilms, all three species were inhibited to a similar degree, demonstrating the synergistic nature of biofilm formation by these species and the dependence of T. denticola on the other two species. In a murine alveolar bone loss model of periodontitis oxantel addition to the drinking water of P. gingivalis-infected mice reduced bone loss to the same level as the uninfected control.

What is apelin?

Apelin, a small regulatory peptide, is the endogenous ligand for the apelin receptor (APJ) receptor.

[25711427, 25362565, 25965959, 25491175, 25486928, 25380625, 25668242, 26149233, 25931124, 26491547]

Obesity is a major health problem worldwide. The prevalence of obesity is increasing in both developed and developing countries. In the UK, for example, 60% of adults are overweight and 25% are obese. Obesity is associated with many pathological complications including respiratory, cardiovascular and endocrine, but it also affects fertility and is associated with many reproductive complications. This has led us and others to investigate links between women with high BMI, pregnancy outcome and uterine function. These studies in turn have led investigators to ask how obesity can have such an impact on reproduction and, as part of this, to consider the role of the adipokines released from adipose tissues. Our focus in this short review is on adipokines and myometrial activity, and for completeness we overview their effects on other smooth muscles. To date four adipokines (leptin, visfatin, apelin and ghrelin) have been investigated and all affect myometrial contractility, but some more potently than others. We consider the possible mechanisms involved in how adipokines may modify uterine contractility, and discuss the potential impact on labor and delivery. The adipocytokine apelin is a peptide, Apelin and its receptor are abundantly expressed in the nervous and cardiovascular systems. Previous studies had found apelin-13 reduces brain injuries and postischemic cerebral edema through blocking programmed cell death, Apelin-13 is also able to inhibit glucose deprivation induced cardiomyocyte autophagy in a concentration dependent fashion. To observe the effect of Apelin-13 on the brain injury induced by traumatic brain injury (TBI), and explore the effect of Apelin-13 on autophagy in TBI, We performed The neurological test, and the numbers of TBI-induced neural cell death were also counted by propidium iodide labeling. At last, the autophagy associated proteins LC3, Beclin-1, Bcl-2, p62 were also assessed with western-blotting. Compared with saline vehicle groups, the neural cell death, lesion volume, and neural dysfunction were attenuated by apelin-13 after TBI. In additionally, Apelin-13 also reversed TBI induced downregulation of LC3, Beclin-1, Bcl-2, p62 expression, compared with saline vehicle groups, at 24 and 48 h post TBI. Apelin-13 attenuates TBI induced brain damage by suppressing autophagy. All these results revealed that Apelin-13 suppressed autophagy. The autophagy may be involved in the mechanism of Apelin-13 rescue the subsequent damaged neuron in TBI. Protection and replenishment of a functional pancreatic β-cell mass (BCM) are key goals of all diabetes therapies. Apelin, a small regulatory peptide, is the endogenous ligand for the apelin receptor (APJ) receptor. The apelin-APJ signaling system is expressed in rodent and human islet cells. Apelin exposure has been shown to inhibit and to stimulate insulin secretion. Our aim was to assess the influence of a selective APJ deletion in pancreatic islet cells on islet homeostasis and glucose tolerance in mice. Cre-LoxP strategy was utilized to mediate islet APJ deletion. APJ deletion in islet cells (APJ(Δislet)) resulted in a significantly reduced islet size, density and BCM. An ip glucose tolerance test showed significantly impaired glucose clearance in APJ(Δislet) mice. APJ(Δislet) mice were not insulin resistant and in vivo glucose-stimulated insulin secretion was reduced modestly. In vitro glucose-stimulated insulin secretion showed a significantly reduced insulin secretion by islets from APJ(Δislet) mice. Glucose clearance in response to ip glucose tolerance test in obese APJ(Δislet) mice fed a chronic high-fat (HF) diet, but not pregnant APJ(Δislet) mice, was impaired significantly. In addition, the obesity-induced adaptive elevations in mean islet size and fractional islet area were reduced significantly in obese APJ(Δislet) mice when compared with wild-type mice. Together, these findings demonstrate a stimulatory role for the islet cell apelin-APJ signaling axis in regulation of pancreatic islet homeostasis and in metabolic induced β-cell hyperplasia. The results indicate the apelin-APJ system can be exploited for replenishment of BCM. BACKGROUND: C-terminal fragments of adipokine apelin are able to attenuate myocardial ischemia-reperfusion (I/R) injury, but whether their effects are manifested during cardioplegic arrest remain obscure. This study was designed to evaluate the efficacy of natural apelin-12 (H-Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Met-Pro-Phe-OH, A12) and its novel structural analogs (H-(N(α)Me)Arg-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Nle-Pro-Phe-OH, AI, and N(G)-Arg(N(G)NO2)-Pro-Arg-Leu-Ser-His-Lys-Gly-Pro-Nle-Pro-Phe-NH2, AII) as additives to crystalloid cardioplegia and explore benefits of early reperfusion with these peptides. METHODS: Isolated working rat hearts subjected to normothermic global ischemia and further reperfusion were used. St. Thomas' Hospital cardioplegic solution No.2 (STH2) containing 140 μM A12, AI, or AII was infused for 5 min at 25 °C before ischemia. In separate series, peptide administration was used for 5 min after ischemia. Metabolic state of the hearts was evaluated by myocardial content of high energy phosphates and lactate. Lactate dehydrogenase (LDH) leakage was assessed in myocardial effluent on early reperfusion. RESULTS: Addition of the peptides to STH2 enhanced functional and metabolic recovery of reperfused hearts compared with those of control (STH2 without additives). Cardioplegia with analog AII was the most effective and accompanied by a reduction of postischemic LDH leakage. Infusion of A12, AI, or AII after ischemia improved the majority indices of cardiac function and metabolic state of the heart by the end of reperfusion. However, the overall protective effect of the peptides was less than when they were added to STH2. CONCLUSIONS: Enhancement of apelin bioavailability may minimize myocardial I/R damage during cardiac surgery. Structural analogs of A12 are promising components of clinical cardioplegic solutions. Children with sickle cell disease (SCD) have painful vaso-occlusive episodes (VOEs), which often reoccur across the individual's lifespan. Vaso-constrictive and vaso-dilatory molecules have been hypothesized to play a role in VOEs. Endothelin-1 (ET-1) is a potent vasoconstrictor that is released during VOEs and is correlated with pain history. Apelin is a vaso-dilatory peptide that also has a modulatory role in pain processing. We hypothesize that the ratio between vaso-dilatory and vaso-constrictive tone in children with SCD may be a marker of pain sensitization and vaso-occlusion. Plasma endothelin and apelin levels were measured in 47 children with SCD. Procedural pain and baseline pain were assessed via child- and caregiver-reports and observational distress. Pain history was assessed using retrospective chart review. Plasma apelin was related to age, with decreased levels in older children. The ratio between apelin and ET-1 was negatively correlated to observational baseline pain. The ratio between apelin and Big ET was negatively correlated to caregiver ratings of baseline pain and positively correlated to history of VOEs, which is possibly due to hydroxyurea treatment. These results suggest that an imbalance in the apelin and endothelin systems may contribute to an increasing number of VOEs and baseline pain in children with SCD. The aim of this study was to determine the levels of regulatory peptides apelin, glucagon-like peptide (GLP-1) and visfatin in hypercholesterolemic and hyperhomocysteinemic state and to examine their relation with nitric oxide (NO) metabolism. 32 Male guinea pigs were divided into four groups and each group was fed as follows: (a) commercial chow, (b) cholesterol (chol)-rich diet, (c) methionine (meth)-rich diet, and (d) chol + meth-rich diet. Blood samples were drawn at the end of 10 weeks, and abdominal aorta was dissected for histopathological examination. Serum insulin, GLP-1, apelin, visfatin, and nitrotyrosine concentrations were measured by the manufacturer's kits based on ELISA; asymmetric dimethylarginine (ADMA) and arginine levels were measured by the high performance liquid chromatography. Homocysteine level was measured by the chemiluminescence immunoassay; glucose, total chol and triglyceride levels were measured by the autoanalyzer. The microscopic examination of aorta indicated varying degrees of vascular disturbance in chol- and chol + meth-fed groups. High levels of chol and homocysteine, accompanied with significantly low levels of apelin and GLP-1 were detected in the plasma. Visfatin, ADMA, and nitrotyrosine levels both in chol- and chol + meth-fed groups were significantly higher than those in control animals, whereas arginine and arginine/ADMA ratio were lower. This study indicated that circulating levels of apelin, GLP-1, and visfatin are markedly altered during the development of atherosclerotic changes in close association with chol, homocysteine, NO, and ADMA levels. The measurements of these peptides in serum may help for the diagnosis and follow-up of vascular dysfunction. Apelin is a novel bioactive peptide as the endogenous ligand for APJ. Apelin and APJ have also been identified in the testis, hypothalamic nuclei such as arcuate, supraoptic and paraventricular nuclei, implicating roles in the control of reproduction. Therefore, the present study was designed to investigate the effects of chronic central infusion of apelin-13 on LH, FSH and testosterone levels and testis morphology. 21 Wistar-Albino male rats received continuous intracerebroventricular infusion via Alzet osmotic mini pumps filled artificial cerebrospinal fluid (vehicle) or apelin-13 at concentrations of 1 or 10 nmol (10 μl/h) for seven days. At the last 90 min of the infusion period, the blood samples were collected at 15 min intervals (0-90 min) for LH and FSH analyses. At the last sampling point, the blood samples were analyzed for testosterone levels. Infusion of high dose apelin-13 significantly suppressed LH release compared with the vehicle values at 30, 60 and 75 min (p<0.05). However, FSH levels did not significantly differ among the groups. Serum testosterone levels in high dose apelin-13 group were statistically lower than the control group (p<0.05). In addition, histological examination showed that infusion of high dose apelin-13 significantly decreased the number of Leydig cells compared with the control and lower dose apelin-13 groups (p<0.05, p<0.01). Our results suggest that apelin-13 may play a role in the central regulation and decreases testosterone release by suppressing LH secretion. Thus, antagonists of the apelin receptor may, therefore, be useful for pharmaceuticals in the treatment of infertility. Pericytes are a population of cells that participate in normal vessel architecture and regulate permeability. Apelin, as the endogenous ligand of G protein-coupled receptor APJ, participates in a number of physiological and pathological processes. To date, the effect of apelin on pericyte is not clear. Our study aimed to investigate the potential protection mechanisms of apelin, with regard to primary rat retinal pericytes under hypoxia. Immunofluorescence staining revealed that pericytes colocalized with APJ in the fibrovascular membranes dissected from proliferative diabetic retinopathy patients. In the in vitro studies, we first demonstrated that the expression of apelin/APJ was upregulated in pericytes under hypoxia, and apelin increased pericytes proliferation and migration. Moreover, knockdown of apelin in pericyte was achieved via lentivirus-mediated RNA interference. After the inhibition of apelin, pericytes proliferation was inhibited significantly in hypoxia culture condition. Furthermore, exogenous recombinant apelin effectively prevented hypoxia-induced apoptosis through downregulating active-caspase 3 expression and increasing the ratio of B cell lymphoma-2 (Bcl-2)/Bcl-2 associated X protein (Bax) in pericytes. These results suggest that apelin suppressed hypoxia-induced pericytes injury, which indicated that apelin could be a potential therapeutic target for retinal angiogenic diseases.

What is the function of the protein encoded by the gene PABPC4?

The main function of PABPC4 is in mRNA stability and translation initiation. PABPC4 may also play a role in chronic inflammation and in the pathogenesis of colorectal cancer.

[23938467, 20943973, 11328870, 22884093, 22530058, 22896784, 23181716, 23300856, 21300955, 21940797]

Spermiogenesis is a postmeiotic process that drives development of round spermatids into fully elongated spermatozoa. Spermatid elongation is largely controlled post-transcriptionally after global silencing of mRNA synthesis from the haploid genome. Here, rats that differentially express EGFP from a lentiviral transgene during early and late steps of spermiogenesis were used to flow sort fractions of round and elongating spermatids. Mass-spectral analysis of 2D gel protein spots enriched >3-fold in each fraction revealed a heterogeneous RNA binding proteome (hnRNPA2/b1, hnRNPA3, hnRPDL, hnRNPK, hnRNPL, hnRNPM, PABPC1, PABPC4, PCBP1, PCBP3, PTBP2, PSIP1, RGSL1, RUVBL2, SARNP2, TDRD6, TDRD7) abundantly expressed in round spermatids prior to their elongation. Notably, each protein within this ontology cluster regulates alternative splicing, sub-cellular transport, degradation and/or translational repression of mRNAs. In contrast, elongating spermatid fractions were enriched with glycolytic enzymes, redox enzymes and protein synthesis factors. Retrogene-encoded proteins were over-represented among the most abundant elongating spermatid factors identified. Consistent with these biochemical activities, plus corresponding histological profiles, the identified RNA processing factors are predicted to collectively drive post-transcriptional expression of an alternative exome that fuels finishing steps of sperm maturation and fitness. In testis mRNA stability and translation initiation are extensively under the control of poly(A)-binding proteins (PABP). Here we have cloned a new human testis-specific PABP (PABP3) of 631 amino acids (70.1 kDa) with 92.5% identical residues to the ubiquitous PABP1. A northern blot of multiple human tissues hybridised with PABP3- and PABP1-specific oligonucleotide probes revealed two PABP3 mRNAs (2.1 and 2.5 kb) detected only in testis, whereas PABP1 mRNA (3.2 kb) was present in all tested tissues. In human adult testis, PABP3 mRNA expression was restricted to round spermatids, whereas PABP1 was expressed in these cells as well as in pachytene spermatocytes. PABP3-specific antibodies identified a protein of 70 kDa in human testis extracts. This protein binds poly(A) with a slightly lower affinity as compared to PABP1. The human PABP3 gene is intronless with a transcription start site 61 nt upstream from the initiation codon. A sequence of 256 bp upstream from the transcription start site drives the promoter activity of PABP3 and its tissue-specific expression. The expression of PABP3 might be a way to bypass PABP1 translational repression and to produce the amount of PABP needed for active mRNA translation in spermatids. Cytoplasmic poly(A) binding protein 4 (PABPC4) is an RNA-processing protein that plays an important role in the regulation of gene expression. The aim of this study was to investigate the expression pattern and identify the potential clinical significance of PABPC4 in colorectal cancer. Immunohistochemical analysis revealed that 26.7% (27/101 patients) of primary colorectal tumors and 60.5% (23/38 patients) of corresponding adjacent, normal tissues showed high cytoplasmic expression of PABPC4, whereas expression was absent in 98% (43/44 patients) of distant, normal tissues. Using Kaplan-Meier analysis, we observed that the expression of PABPC4 was significantly correlated with disease-free survival and overall survival in patients with stage II and stage III colorectal cancer (P=0.022 and P=0.020, respectively). PABPC4 expression was positively associated with survival outcome, and may have predictive value in the prognosis of patients with colorectal cancer. Taken together, our findings indicate that PABPC4 may play a role in the pathogenesis of colorectal cancer. Cytoplasmic poly(A)-binding proteins (PABPs) regulate mRNA stability and translation. Although predominantly localized in the cytoplasm, PABP proteins also cycle through the nucleus. Recent work has established that their steady-state localization can be altered by cellular stresses such as ultraviolet (UV) radiation, and infection by several viruses, resulting in nuclear accumulation of PABPs. Here, we present further evidence that their interaction with and release from mRNA and translation complexes are important in determining their sub-cellular distribution and propose an integrated model for regulated nucleo-cytoplasmic transport of PABPs. BACKGROUND: C-reactive protein (CRP) is a heritable marker of chronic inflammation that is strongly associated with cardiovascular disease. We sought to identify genetic variants that are associated with CRP levels. METHODS AND RESULTS: We performed a genome-wide association analysis of CRP in 66 185 participants from 15 population-based studies. We sought replication for the genome-wide significant and suggestive loci in a replication panel comprising 16 540 individuals from 10 independent studies. We found 18 genome-wide significant loci, and we provided evidence of replication for 8 of them. Our results confirm 7 previously known loci and introduce 11 novel loci that are implicated in pathways related to the metabolic syndrome (APOC1, HNF1A, LEPR, GCKR, HNF4A, and PTPN2) or the immune system (CRP, IL6R, NLRP3, IL1F10, and IRF1) or that reside in regions previously not known to play a role in chronic inflammation (PPP1R3B, SALL1, PABPC4, ASCL1, RORA, and BCL7B). We found a significant interaction of body mass index with LEPR (P<2.9×10(-6)). A weighted genetic risk score that was developed to summarize the effect of risk alleles was strongly associated with CRP levels and explained ≈5% of the trait variance; however, there was no evidence for these genetic variants explaining the association of CRP with coronary heart disease. CONCLUSIONS: We identified 18 loci that were associated with CRP levels. Our study highlights immune response and metabolic regulatory pathways involved in the regulation of chronic inflammation. Poly(A)-binding protein 1 (PABP1) has a fundamental role in the regulation of mRNA translation and stability, both of which are crucial for a wide variety of cellular processes. Although generally a diffuse cytoplasmic protein, it can be found in discrete foci such as stress and neuronal granules. Mammals encode several additional cytoplasmic PABPs that remain poorly characterised, and with the exception of PABP4, appear to be restricted in their expression to a small number of cell types. We have found that PABP4, similarly to PABP1, is a diffusely cytoplasmic protein that can be localised to stress granules. However, UV exposure unexpectedly relocalised both proteins to the nucleus. Nuclear relocalisation of PABPs was accompanied by a reduction in protein synthesis but was not linked to apoptosis. In examining the mechanism of PABP relocalisation, we found that it was related to a change in the distribution of poly(A) RNA within cells. Further investigation revealed that this change in RNA distribution was not affected by PABP knockdown but that perturbations that block mRNA export recapitulate PABP relocalisation. Our results support a model in which nuclear export of PABPs is dependent on ongoing mRNA export, and that a block in this process following UV exposure leads to accumulation of cytoplasmic PABPs in the nucleus. These data also provide mechanistic insight into reports that transcriptional inhibitors and expression of certain viral proteins cause relocation of PABP to the nucleus.

What kind of enzyme is encoded by the proto-oncogene ABL1?

ABL-family proteins comprise one of the best conserved branches of the tyrosine kinases. Each ABL protein contains an SH3-SH2-TK (Src homology 3-Src homology 2-tyrosine kinase) domain cassette, which confers autoregulated kinase activity and is common among nonreceptor tyrosine kinases. This cassette is coupled to an actin-binding and -bundling domain, which makes ABL proteins capable of connecting phosphoregulation with actin-filament reorganization. Two vertebrate paralogs, ABL1 and ABL2, have evolved to perform specialized functions.

[20841568, 19794087, 24012954, 18528425, 9500553, 19290927, 12796783, 18796434, 23842646, 21435002]

ABL-family proteins comprise one of the best conserved branches of the tyrosine kinases. Each ABL protein contains an SH3-SH2-TK (Src homology 3-Src homology 2-tyrosine kinase) domain cassette, which confers autoregulated kinase activity and is common among nonreceptor tyrosine kinases. This cassette is coupled to an actin-binding and -bundling domain, which makes ABL proteins capable of connecting phosphoregulation with actin-filament reorganization. Two vertebrate paralogs, ABL1 and ABL2, have evolved to perform specialized functions. ABL1 includes nuclear localization signals and a DNA binding domain through which it mediates DNA damage-repair functions, whereas ABL2 has additional binding capacity for actin and for microtubules to enhance its cytoskeletal remodeling functions. Several types of posttranslational modifications control ABL catalytic activity, subcellular localization, and stability, with consequences for both cytoplasmic and nuclear ABL functions. Binding partners provide additional regulation of ABL catalytic activity, substrate specificity, and downstream signaling. Information on ABL regulatory mechanisms is being mined to provide new therapeutic strategies against hematopoietic malignancies caused by BCR-ABL1 and related leukemogenic proteins. Protein tyrosine kinases form a large family of signaling proteins implicated in both normal and malignant cell signaling. The aim of this study was to identify protein tyro-sine kinases that can transform hematopoietic cells to growth factor independent proliferation when constitutively activated by homodimerization. We used a modified retroviral insertion mutagenesis screen with a retroviral vector containing the homodimerization domain of ETV6 followed by an artificial splice donor site. Integration of this retroviral vector within a gene of the host genome would generate a fusion transcript containing the dimerization domain and part of the disrupted gene. Using this strategy with the IL3 dependent Ba/F3 cell line, we identified 8 different protein tyrosine kinases (Abl1, Fgfr1, Hck, Jak2, Lck, Mertk, Mst1r, Tnk1) that transformed the cells. These results characterize HCK, MERTK, MST1R and TNK1 as potential oncogenes and describe a method to identify gain-of-function fusion genes using a retroviral insertion screen. The oncogenic BCR/ABL tyrosine kinase induces constitutive enhanced "spontaneous" DNA damage and unfaithful repair in Philadelphia chromosome positive leukemia cells. Here, we investigated the changes of protein profile in H2O2-induced DNA damage/repair in BaF3-MIGR1 and BaF3-BCR/ABL cells through a proteomic strategy consisting of two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF mass spectrometry. In total, 41 spots were differentially expressed and 13 proteins were identified with further MS analysis. Two essential proteins, Proto-oncogene tyrosine-protein kinase ABL1 (c-ABL) and Heat shock 70kDa protein 4 (Apg-2), were confirmed by Western blot and showed consistent changes with proteomic results. Moreover, functional analysis demonstrated that inhibition of Apg-2 not only decreased cell proliferation, but also induced cell apoptosis in BCR/ABL positive cells (BaF3-BCR/ABL, BaF3-BCR/ABL(T315I)). We also proved that Apg-2 inhibition aggravated H2O2 induced damage in BCR/ABL positive cells, and enhanced the sensitivity of BaF3-BCR/ABL(T315I) to STI571. Taken together, the findings in this work provide us with some clues to a better understanding of the molecular mechanisms underlying BCR/ABL in the DNA damage/repair processes and demonstrated that Apg-2 would be a valid target for anti-leukemia drug development. Constitutively activated mutants of the non-receptor tyrosine kinases (TK) ABL1 (Abelson murine leukemia viral (v-abl) homolog (1) protein) and JAK2 (JAnus Kinase 2 or Just Another Kinase 2) play a central role in the pathogenesis of clinically and morphologically distinct chronic myeloproliferative disorders but are also found in some cases of de novo acute leukemia and lymphoma. Ligand-independent activation occurs as a consequence of point mutations or insertions/deletions within functionally relevant regulatory domains (JAK2) or the creation of TK fusion proteins by balanced reciprocal translocations, insertions or episomal amplification (ABL1 and JAK2). Specific abnormalities are correlated with clinical phenotype, although some are broad and encompass several World Health Organization-defined entities. TKs are excellent drug targets as exemplified by the activity of imatinib in BCR-ABL1-positive disease, particularly chronic myeloid leukemia. Resistance to imatinib is seen in a minority of cases and is often associated with the appearance of secondary point mutations within the TK domain of BCR-ABL1. These mutations are highly variable in their sensitivity to increased doses of imatinib or alternative TK inhibitors such as nilotinib or dasatinib. Selective and non-selective inhibitors of JAK2 are currently being developed, and encouraging data from pre-clinical experiments and initial phase-I studies regarding efficacy and potential toxicity of these compounds have already been reported. The ABL1 proto-oncogene encodes a cytoplasmic and nuclear protein tyrosine kinase (c-Abl) that has been implicated in processes of cell differentiation, cell division, cell adhesion and stress response. Alterations of ABL1 by chromosomal rearrangement or viral transduction can lead to malignant transformation. Activity of the c-Abl protein is negatively regulated by its SH3 domain through an unknown mechanism, and deletion of the SH3 domain turns ABL1 into an oncogene. We present evidence for an intramolecular inhibitory interaction of the SH3 domain with the catalytic domain and with the linker between the SH2 and catalytic domain (SH2-CD linker). Site-directed mutations in each of these three elements activate c-Abl. Mutations in the linker cause a conformational change of the molecule and increase binding of the SH3 domain to peptide ligands. Individual mutation of two charged residues in the SH3 and catalytic domain activates c-Abl, while inhibition is restored in the double reciprocal mutant. We propose that regulators of c-Abl will have opposite effects on its activity depending on their ability to favour or disrupt these intramolecular interactions. Stimulation of the T-cell antigen receptor (TCR) leads to the activation of signaling pathways that are essential for T-cell development and the response of mature T cells to antigens. The TCR has no intrinsic catalytic activity, but TCR engagement results in tyrosine phosphorylation of downstream targets by non-receptor tyrosine kinases. Three families of tyrosine kinases have long been recognized to play critical roles in TCR-dependent signaling. They are the Src, zeta-associated protein of 70 kDa, and Tec families of kinases. More recently, the Abelson (Abl) tyrosine kinases have been shown to be activated by TCR engagement and to be required for maximal TCR signaling. Using T-cell conditional knockout mice deficient for Abl family kinases, Abl (Abl1) and Abl-related gene (Arg) (Abl2), it was recently shown that loss of Abl kinases results in defective T-cell development and a partial block in the transition to the CD4(+)CD8(+) stage. Abl/Arg double null T cells exhibit impaired TCR-induced signaling, proliferation, and cytokine production. Moreover, conditional knockout mice lacking Abl and Arg in T cells exhibit impaired CD8(+) T-cell expansion in vivo upon Listeria monocytogenes infection. Thus, Abl kinase signaling is required for both T-cell development and mature T-cell function. Agrin signals through the muscle-specific receptor tyrosine kinase (MuSK) to cluster acetylcholine receptors (AChRs) on the postsynaptic membrane of the neuromuscular junction (NMJ). This stands as the prevailing model of synapse induction by a presynaptic factor, yet the agrin-dependent MuSK signaling cascade is largely undefined. Abl1 (previously known as Abl) and the Abl1-related gene product Abl2 (previously known as Arg) define a family of tyrosine kinases that regulate actin structure and presynaptic axon guidance. Here we show that the Abl kinases are critical mediators of postsynaptic assembly downstream of agrin and MuSK. In mouse muscle, Abl kinases were localized to the postsynaptic membrane of the developing NMJ. In cultured myotubes, Abl kinase activity was required for agrin-induced AChR clustering and enhancement of MuSK tyrosine phosphorylation. Moreover, MuSK and Abl kinases effected reciprocal tyrosine phosphorylation and formed a complex after agrin engagement. Our findings suggest that Abl kinases provide the developing synapse with the kinase activity required for signal amplification and the intrinsic cytoskeletal regulatory capacity required for assembly and remodeling. ABL family tyrosine kinases are tightly regulated by autoinhibition and phosphorylation mechanisms. These kinases maintain an inactive conformation through intramolecular interactions involving SH3 and SH2 domains. RIN1, a downstream effector of RAS, binds to the ABL SH3 and SH2 domains and stimulates ABL tyrosine kinase activity. RIN1 binding to the ABL2 kinase resulted in a large decrease in Km and a small increase in Vmax toward an ABL consensus substrate peptide. The enzyme efficiency (k(cat)/Km) was increased more than 5-fold by RIN1. In addition, RIN1 strongly enhanced ABL-mediated phosphorylation of CRK, PSTPIP1, and DOK1, all established ABL substrates but with unique protein structures and distinct target sequences. Importantly RIN1-mediated stimulation of ABL kinase activity was independent of activation by SRC-mediated phosphorylation. RIN1 increased the kinase activity of both ABL1 and ABL2, and this occurred in the presence or absence of ABL regulatory domains outside the SH3-SH2-tyrosine kinase domain core. We further demonstrate that a catalytic site mutation associated with broad drug resistance, ABL1T315I, remains responsive to stimulation by RIN1. These findings are consistent with an allosteric kinase activation mechanism by which RIN1 binding promotes a more accessible ABL catalytic site through relief of autoinhibition. Direct disruption of RIN1 binding may therefore be a useful strategy to suppress the activity of normal and oncogenic ABL, including inhibitor-resistant mutants that confound current therapeutic strategies. Stimulation through derepression may be applicable to many other tyrosine kinases autoinhibited by coupled SH3 and SH2 domains. Chromosomal rearrangements involving the ABL1 gene, leading to a BCR-ABL1 fusion gene, have been mainly associated with chronic myeloid leukemia and B-cell acute lymphoblastic leukemia (ALL). At present, six other genes have been shown to fuse to ABL1. The kinase domain of ABL1 is retained in all chimeric proteins that are also composed of the N-terminal part of the partner protein that often includes a coiled-coil or a helix-loop-helix domain. These latter domains allow oligomerization of the protein that is required for tyrosine kinase activation, cytoskeletal localization, and neoplastic transformation. Fusion genes that have a break in intron 1 or 2 (BCR-ABL1, ETV6-ABL1, ZMIZ1-ABL1, EML1-ABL1, and NUP214-ABL1) have transforming activity, although NUP214-ABL1 requires amplification to be efficient. The NUP214-ABL1 gene is the second most prevalent fusion gene involving ABL1 in malignant hemopathies, with a frequency of 5% in T-cell ALL. Both fusion genes (SFPQ-ABL1 and RCSD1-ABL1) characterized by a break in intron 4 of ABL1 are associated with B-cell ALL, as the chimeric proteins lacked the SH2 domain of ABL1. Screening for ABL1 chimeric genes could be performed in patients with ALL, more particularly in those with T-cell ALL because ABL1 modulates T-cell development and plays a role in cytoskeletal remodeling processes in T cells.

What is the mode of inheritance of Romano Ward long QT syndrome?

The Romano Ward long QT syndrome (LQTS) has an autosomal dominant mode of inheritance.

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Loss of consciousness in childhood may be due to cardiovascular causes, and the Long Q-T syndromes can present with seizures. The Romano-Ward syndrome is of autosomal dominant inheritance, and the Jervell and Lange-Nielson syndrome, with associated deafness, of autosomal recessive inheritance. The diagnosis is often delayed, but a careful history can avoid this. The syndromes can appear to be due to an imbalance in the sympathetic nerve to the ventricular myocardium, and precipitating causes such as stress suggest a CNS influence on this. The electrocardiogram can confirm the prolonged Q-T interval, but this is not always present, at least without an exercise test. Treatment with beta-blockers is often successful. If a wrong diagnosis of epilepsy is made a chance may be missed of avoiding sudden death, quite apart from all the medical, and social consequences that can result from such a diagnosis. A family with the Romano-Ward syndrome is presented. This family showed typical features of this syndrome with QT prolongation, torsades de pointes ventricular tachycardia, sudden death and an autosomal dominant inheritance pattern. The index case presented with an exacerbation of torsades de pointes ventricular tachycardia from diuretic induced hypokalaemia, and responded to diuretic withdrawal and beta blocker therapy. Long QT and short QT syndromes (LQTS and SQTS) are cardiac repolarization abnormalities that are characterized by length perturbations of the QT interval as measured on electrocardiogram (ECG). Prolonged QT interval and a propensity for ventricular tachycardia of the torsades de pointes (TdP) type are characteristic of LQTS, while SQTS is characterized by shortened QT interval with tall peaked T-waves and a propensity for atrial fibrillation. Both syndromes represent a high risk for syncope and sudden death. LQTS exists as a congenital genetic disease (cLQTS) with more than 700 mutations described in 12 genes (LQT1-12), but can also be acquired (aLQTS). The genetic forms of LQTS include Romano-Ward syndrome (RWS), which is characterized by isolated LQTS and an autosomal dominant pattern of inheritance, and syndromes with LQTS in association with other conditions. The latter includes Jervell and Lange-Nielsen syndrome (JLNS), Andersen syndrome (AS), and Timothy syndrome (TS). The genetics are further complicated by the occurrence of double and triple heterozygotes in LQTS and a considerable number of nonpathogenic rare polymorphisms in the involved genes. SQTS is a very rare condition, caused by mutations in five genes (SQTS1-5). The present mutation update is a comprehensive description of all known LQTS- and SQTS-associated mutations. Romano-Ward syndrome is an autosomal dominant long-QT syndrome (LQTS) that predisposes affected individuals to sudden death from tachyarrhythmias. We investigated the molecular basis of LQTS in a Taiwanese kindred. Clinical and genetic analyses revealed that a mutation was linked to the human ether-a-go-go-related gene (HERG). The coding sequences and exon-intron borders of HERG were amplified by means of polymerase chain reaction and subjected to single-strand conformation polymorphism (SSCP) analysis. An exon with an aberrant SSCP pattern was cloned and sequenced to study the molecular lesion. A C-->T transition in codon 614, leading to substitution of a valine for an alanine residue in the pore region of the HERG protein, was identified. Analysis with Bsp12861 endonuclease digestion showed the mutation to be present in all affected family members. Given that an unaffected paternal uncle had inherited the same allele from the grandfather as the proband's father, a de novo mutation had apparently occurred in the father and was transmitted to his offspring. In addition to offering presymptomatic genetic diagnosis, identification of the disease-causing mutation may suggest new therapeutic approaches for treatment and prevention of this cardiovascular disease. OBJECTIVE: Hereditary long QT syndrome (LQTS) is a genetically heterogeneous disease characterized by prolonged QT intervals and an increased risk for ventricular arrhythmias and sudden cardiac death. Mutations in the voltage-gated potassium channel subunit KCNQ1 induce the most common form of LQTS. KCNQ1 is associated with two different entities of LQTS, the autosomal-dominant Romano-Ward syndrome (RWS), and the autosomal-recessive Jervell and Lange-Nielsen syndrome (JLNS) characterized by bilateral deafness in addition to cardiac arrhythmias. In this study, we investigate and discuss dominant-negative I(Ks) current reduction by a KCNQ1 deletion mutation identified in a RWS family. METHODS: Single-strand conformation polymorphism analysis and direct sequencing were used to screen LQTS genes for mutations. Mutant KCNQ1 channels were heterologously expressed in Xenopus oocytes, and potassium currents were recorded using the two-microelectrode voltage clamp technique. RESULTS: A heterozygous deletion of three nucleotides (CTT) identified in the KCNQ1 gene caused the loss of a single phenylalanine residue at position 339 (KCNQ1-deltaF339). Electrophysiological measurements in the presence and absence of the regulatory beta-subunit KCNE1 revealed that mutant and wild type forms of an N-terminal truncated KCNQ1 subunit (isoform 2) caused much stronger dominant-negative current reduction than the mutant form of the full-length KCNQ1 subunit (isoform 1). CONCLUSION: This study highlights the functional relevance of the truncated KCNQ1 splice variant (isoform 2) in establishment and mode of inheritance in long QT syndrome. In the RWS family presented here, the autosomal-dominant trait is caused by multiple dominant-negative effects provoked by heteromultimeric channels formed by wild type and mutant KCNQ1-isoforms in combination with KCNE1. The Romano-Ward long QT syndrome, an autosomal dominant inherited disorder, is an increasingly recognized cause of sudden cardiac death in children and adults. Sudden death may or may not be preceded by a history of "seizures" and recurrent syncope; the diagnosis relies on electrocardiographic evidence, including prolongation of the QT interval corrected for heart rate, T wave abnormalities, sinus bradycardia, and polymorphous ventricular tachycardia (torsades de pointes). Recently, a gene responsible for causing long QT syndrome was localized (using molecular genetic methods) to the short arm of chromosome 11 (11p15.5) in the region near the Harvey ras-1 locus. The purpose of this report is to describe the current molecular genetic understanding of long QT syndrome, including information regarding gene mapping, genetic heterogeneity, and prenatal or presymptomatic diagnosis.

Which histone modifications have been associated to alternative splicing?

H3K36m3 has been systematically associated to exon inclusion in almost all published studies. Other marks have been associated as well in specific studies to exon expression, but it can not be concluded that the effect of these marks in exon expression it is not a consequence of their effect in gene expression.

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The genomes of higher organisms are packaged in nucleosomes with functional histone modifications. Until now, genome-wide nucleosome and histone modification studies have focused on transcription start sites (TSSs) where nucleosomes in RNA polymerase II (RNAPII) occupied genes are well positioned and have histone modifications that are characteristic of expression status. Using public data, we here show that there is a higher nucleosome-positioning signal in internal human exons and that this positioning is independent of expression. We observed a similarly strong nucleosome-positioning signal in internal exons of Caenorhabditis elegans. Among the 38 histone modifications analyzed in man, H3K36me3, H3K79me1, H2BK5me1, H3K27me1, H3K27me2, and H3K27me3 had evidently higher signals in internal exons than in the following introns and were clearly related to exon expression. These observations are suggestive of roles in splicing. Thus, exons are not only characterized by their coding capacity, but also by their nucleosome organization, which seems evolutionarily conserved since it is present in both primates and nematodes. Splicing is a complex process regulated by sequence at the classical splice sites and other motifs in exons and introns with an enhancing or silencing effect. In addition, specific histone modifications on nucleosomes positioned over the exons have been shown to correlate both positively and negatively with exon expression. Here, we trained a model of "IF … THEN …" rules to predict exon inclusion levels in a transcript from histone modification patterns. Furthermore, we showed that combinations of histone modifications, in particular those residing on nucleosomes preceding or succeeding the exon, are better predictors of exon inclusion levels than single modifications. The resulting model was evaluated with cross validation and had an average accuracy of 72% for 27% of the exons, which demonstrates that epigenetic signals substantially mark alternative splicing. BACKGROUND: While alternative splicing (AS) contributes greatly to protein diversities, the relationship between various types of AS and epigenetic factors remains largely unknown. RESULTS: In this study, we discover that a number of epigenetic features, including DNA methylation, nucleosome occupancy, specific histone modifications and protein features, are strongly associated with AS. To further enhance our understanding of the association between these features and AS, we cluster our investigated features based on their association patterns with each AS type into four groups, with H3K36me3, EGR1, GABP, SRF, SIN3A and RNA Pol II grouped together and showing strongest association with AS. In addition, we find that the AS types can be classified into two general classes, namely the exon skipping related process (ESRP), and the alternative splice site selection process (ASSP), based on their association levels with the epigenetic features. CONCLUSION: Our analysis thus suggests that epigenetic features are likely to play important roles in regulating AS. Pre-mRNA splicing is a complex process involving combinatorial effects of cis- and trans-elements. Here, we focused on histone modifications as typical trans-regulatory elements and performed systematic analyses of associations between splicing patterns and histone modifications by using publicly available ChIP-Seq, mRNA-Seq, and exon-array data obtained in two human cell lines. We found that several types of histone modifications including H3K36me3 were associated with the inclusion or exclusion of alternative exons. Furthermore, we observed that the levels of H3K36me3 and H3K79me1 in the cell lines were well correlated with the differences in alternative splicing patterns between the cell lines. Variation in patterns of methylations of histone tails reflects and modulates chromatin structure and function. To provide a framework for the analysis of chromatin function in Caenorhabditis elegans, we generated a genome-wide map of histone H3 tail methylations. We find that C. elegans genes show distributions of histone modifications that are similar to those of other organisms, with H3K4me3 near transcription start sites, H3K36me3 in the body of genes and H3K9me3 enriched on silent genes. We also observe a novel pattern: exons are preferentially marked with H3K36me3 relative to introns. H3K36me3 exon marking is dependent on transcription and is found at lower levels in alternatively spliced exons, supporting a splicing-related marking mechanism. We further show that the difference in H3K36me3 marking between exons and introns is evolutionarily conserved in human and mouse. We propose that H3K36me3 exon marking in chromatin provides a dynamic link between transcription and splicing. Alternative splicing of pre-mRNA is a prominent mechanism to generate protein diversity, yet its regulation is poorly understood. We demonstrated a direct role for histone modifications in alternative splicing. We found distinctive histone modification signatures that correlate with the splicing outcome in a set of human genes, and modulation of histone modifications causes splice site switching. Histone marks affect splicing outcome by influencing the recruitment of splicing regulators via a chromatin-binding protein. These results outline an adaptor system for the reading of histone marks by the pre-mRNA splicing machinery. While much attention has been focused on chromatin at promoters and exons, human genes are mostly composed of intronic sequences. Analyzing published surveys of nucleosomes and 41 chromatin marks in humans, we identified histone modifications specifically associated with 5' intronic sequences, distinguishable from promoter marks and bulk nucleosomes. These intronic marks were spatially reciprocal to trimethylated histone H3 Lys36 (H3K36me3), typically transitioning near internal exons. Several marks transitioned near bona fide exons, but not near nucleosomes at exon-like sequences. Therefore, we examined whether splicing affects histone marking. Even with considerable changes in regulated alternative splicing, histone marks were stable. Notably, these findings are consistent with exon definition influencing histone marks. In summary, we show that the location of many intragenic marks in humans can be distilled into a simple organizing principle: association with 5' intronic or 3' exonic regions. MOTIVATION: Chromatin structure, including post-translational modifications of histones, regulates gene expression, alternative splicing and cell identity. ChIP-seq is an increasingly used assay to study chromatin function. However, tools for downstream bioinformatics analysis are limited and are only based on the evaluation of signal intensities. We reasoned that new methods taking into account other signal characteristics such as peak shape, location and frequencies might reveal new insights into chromatin function, particularly in situation where differences in read intensities are subtle. RESULTS: We introduced an analysis pipeline, based on linear predictive coding (LPC), which allows the capture and comparison of ChIP-seq histone profiles. First, we show that the modeled signal profiles distinguish differentially expressed genes with comparable accuracy to signal intensities. The method was robust against parameter variations and performed well up to a signal-to-noise ratio of 0.55. Additionally, we show that LPC profiles of activating and repressive histone marks cluster into distinct groups and can be used to predict their function. AVAILABILITY AND IMPLEMENTATION: http://www.cancerresearch.unsw.edu.au/crcweb.nsf/page/LPCHP A Matlab implementation along with usage instructions and an example input file are available from: http://www.cancerresearch.unsw.edu.au/crcweb.nsf/page/LPCHP. Recent genome-wide studies have revealed a remarkable correspondence between nucleosome positions and exon-intron boundaries, and several studies have implicated specific histone modifications in regulating alternative splicing. In addition, recent progress in cracking the 'splicing code' shows that sequence motifs carried on the nascent RNA molecule itself are sufficient to accurately predict tissue-specific alternative splicing patterns. Together, these studies shed light on the complex interplay between RNA sequence, DNA sequence, and chromatin properties in regulating splicing. Alternative splicing affects more than 90% of human genes. Coupling between transcription and splicing has become crucial in the complex network underlying alternative splicing regulation. Because chromatin is the real template for nuclear transcription, changes in its structure, but also in the "reading" and "writing" of the histone code, could modulate splicing choices. Here, we discuss the evidence supporting these ideas, from the first proposal of chromatin affecting alternative splicing, performed 20 years ago, to the latest findings including genome-wide evidence that nucleosomes are preferentially positioned in exons. We focus on two recent reports from our laboratories that add new evidence to this field. The first report shows that a physiological stimulus such as neuron depolarization promotes intragenic histone acetylation (H3K9ac) and chromatin relaxation, causing the skipping of exon 18 of the neural cell adhesion molecule gene. In the second report, we show how specific histone modifications can be created at targeted gene regions as a way to affect alternative splicing: Using small interfering RNAs (siRNAs), we increased the levels of H3K9me2 and H3K27me3 in the proximity of alternative exon 33 of the human fibronectin gene, favoring its inclusion into mature messenger RNA (mRNA) through a mechanism that recalls RNA-mediated transcriptional gene silencing. How are short exonic sequences recognized within the vast intronic oceans in which they reside? Despite decades of research, this remains one of the most fundamental, yet enigmatic, questions in the field of pre-mRNA splicing research. For many years, studies aiming to shed light on this process were focused at the RNA level, characterizing the manner by which splicing factors and auxiliary proteins interact with splicing signals, thereby enabling, facilitating and regulating splicing. However, we increasingly understand that splicing is not an isolated process; rather it occurs co-transcriptionally and is presumably also regulated by transcription-related processes. In fact, studies by our group and others over the past year suggest that DNA structure in terms of nucleosome positioning and specific histone modifications, which have a well established role in transcription, may also have a role in splicing. In this review we discuss evidence for the coupling between transcription and splicing, focusing on recent findings suggesting a link between chromatin structure and splicing, and highlighting challenges this emerging field is facing.

Is phospholamban phosphorylated by Protein kinase A?

Phospholamban (PLB) is a sarcoplasmic reticulum (SR) protein that is phosphorylated at Ser16 by PKA. Phosphorylation of PLB by PKA reverses the inhibitory action of PLB.

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We previously found that a canine model of selective surgical ventricular denervation (VD), which does not permit increased sympathetic tone during the pathogenesis of heart failure (HF), tolerated the development of HF better than controls. To investigate the cellular mechanisms, we examined cellular contraction and L-type Ca(2+) channel currents (I(Ca)) and their responses to beta-adrenergic receptor (beta-AR) stimulation in left ventricular myocytes from 1) control, 2) VD, 3) HF induced by rapid pacing, and 4) HF induced in VD (VD-HF) dogs. The magnitude of myocyte contraction and rate of relaxation in VD were similar to control but were depressed in both HF and VD-HF. These changes were associated with reduced protein expression of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a) and protein kinase A phosphorylated phospholamban (PLB), which was reduced in HF, but essentially abolished in VD-HF. beta-AR kinase (GRK2) was increased in HF but reduced in VD-HF. Basal I(Ca) density did not differ among control, VD, and HF groups, but VD-HF myocytes showed a markedly reduced I(Ca) density (approximately 40%). Compared to controls, the sensitivity of I(Ca) to isoproterenol (ISO), was significantly higher in VD, but reduced in HF. While I(Ca) responses to ISO in VD-HF were maintained at control levels, the amplitude of the ISO-stimulated I(Ca) was significantly smaller (approximately 50%) compared with HF myocytes. The relative decrease in Ca(2+) influx due to downregulation of I(Ca) density may contribute to the cardioprotective effects in VD-HF hearts by preventing Ca(2+) overload during the development of HF. These findings, in combination with the virtual abolition of phosphorylated PLB in VD-HF and the decrease in GRK2, may explain, in part, why VD dogs tolerate the development of HF better than control dogs. Activation of cardiac muscle sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) by beta1-agonists involves cAMP- and PKA-dependent phosphorylation of phospholamban (PLB), which relieves the inhibitory effects of PLB on SERCA2a. To investigate the mechanism of SERCA2a activation, we compared the kinetic properties of SERCA2a expressed with (+) and without (-) PLB in High Five insect cell microsomes to those of SERCA1 and SERCA2a in native skeletal and cardiac muscle SR. Both native SERCA1 and expressed SERCA2a without PLB exhibited high-affinity (10-50 microM) activation of pre-steady-state catalytic site dephosphorylation by ATP, steady-state accumulation of the ADP-sensitive phosphoenzyme (E1P), and a rapid phase of EGTA-induced phosphoenzyme (E2P) hydrolysis. In contrast, SERCA2a in native cardiac SR vesicles and expressed SERCA2a with PLB lacked the high-affinity activation by ATP and the rapid phase of E2P hydrolysis, and exhibited low steady-state levels of E1P. The results indicate that the kinetic differences in Ca2+ transport between skeletal and cardiac SR are due to the presence of phospholamban in cardiac SR, and not due to isoform-dependent differences between SERCA1 and SERCA2a. Therefore, the results are discussed in terms of a model in which PLB interferes with SERCA2a oligomeric interactions, which are important for the mechanism of Ca2+ transport in skeletal muscle SERCA1 [Mahaney, J. E., Thomas, D. D., and Froehlich, J. P. (2004) Biochemistry 43, 4400-4416]. We propose that intermolecular coupling of SERCA2a molecules during catalytic cycling is obligatory for the changes in Ca2+ transport activity that accompany the relief of PLB inhibition of the cardiac SR Ca2+-ATPase. Sarcoplasmic reticulum (SR) dysfunction is one of the multiple alterations that occurs in ischemia-reperfused hearts. Because SR function is regulated by phosphorylation of phospholamban (PLB), a SR protein phosphorylated by cAMP-dependent protein kinase (PKA) at Ser(16)and Ca(2+)-calmodulin-dependent protein kinase (CaMKII) at Thr(17), the phosphorylation of these residues during ischemia and reperfusion was examined in Langendorff-perfused rat hearts. Ser(16)phosphorylation increased significantly after 20 min of ischemia from 2.5+/-0.6% to 99.8+/-25.5% of maximal isoproterenol-induced site-specific phosphorylation and decreased to control values immediately after reperfusion. Thr(17)phosphorylation transiently increased at 2-5 min of ischemia and at 1 min of reperfusion (R1, 166.2+/-28.2%). The ischemia-induced increase in Ser(16)phosphorylation was significantly diminished in hearts from catecholamine-depleted animals and/or after beta-blockade and abolished in the presence of the PKA-inhibitor, H-89. Thr(17)phosphorylation at the beginning of ischemia was blunted by nifedipine, whereas at R1 it was significantly diminished by perfusion with 0 m m Ca(2+)in the presence of EGTA and by the Na(+)/Ca(2+)exchanger inhibitor KB-R7943. KN-93, used to specifically inhibit CaMKII, decreased Thr(17)phosphorylation at R1 and significantly prolonged half relaxation time. The results demonstrated a dissociation between the phosphorylation of PLB sites, being phosphorylation of Ser(16)dependent on the beta-adrenergic cascade during ischemia and phosphorylation of Thr(17)on Ca(2+)influx both, at the beginning of ischemia and reperfusion. Phosphorylation of Thr(17)at the onset of reflow may provide the cell a mechanism to cope with Ca(2+)overload, transiently favoring the recovery of relaxation during early reperfusion. The phosphorylation-induced mobility shift of the high molecular weight form of phospholamban (24,500 daltons) in the cardiac sarcoplasmic reticulum produced on 3',5'-cyclic AMP (cAMP)-dependent phosphorylation with 5 mM ATP was resolved into five clear steps on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and on Ca2+-calmodulin-dependent phosphorylation into ten steps. The mobility shift of the low molecular weight form of phospholamban (less than 14,400 daltons) in these reactions occurred in one step and two steps, respectively. With the two protein kinase activities, the electrophoretic pattern of the mobility shifts of the high and low molecular weight forms of phospholamban was similar to that obtained with Ca2+-calmodulin-dependent protein kinase alone. The results of pulse-chase experiments involving the centrifuge column method suggested that the site(s) of phosphorylation by cAMP- and Ca2+-calmodulin-dependent protein kinase activities are on the same phospholamban molecule. Two-dimensional tryptic peptide maps of phosphorylated phospholamban indicated that cAMP-dependent protein kinase phosphorylates at a single site, A, and Ca2+-calmodulin-dependent protein kinase phosphorylates at sites C1 and C2 in the low molecular weight form, where A is different from C1 but may be the same as C2. The high molecular weight form of phospholamban is suggested to be a pentamer of identical monomers (low molecular weight form) having one phosphorylation site for cAMP-dependent protein kinase and two for Ca2+-calmodulin-dependent protein kinase. Phospholamban (PLB) is a sarcoplasmic reticulum (SR) protein that when phosphorylated at Ser16 by PKA and/or at Thr17 by CaMKII increases the affinity of the SR Ca2+ pump for Ca2+. PLB is therefore, a critical regulator of SR function, myocardial relaxation and myocardial contractility. The present study was undertaken to examine the status of PLB phosphorylation after ischemia and reperfusion and to provide evidence about the possible role of the phosphorylation of Thr17 PLB residue on the recovery of contractility and relaxation after a period of ischemia. Experiments were performed in Langendorff perfused hearts from Wistar rats. Hearts were submitted to a protocol of global normothermic ischemia and reperfusion. The results showed that (1) the phosphorylation of Ser16 and Thr17 residues of PLB increased at the end of the ischemia and the onset of reperfusion, respectively. The increase in Thr17 phosphorylation was associated with a recovery of relaxation to preischemic values. This recovery occurred in spite of the fact that contractility was depressed. (2) The reperfusion-induced increase in Thr17 phosphorylation was dependent on Ca2+ entry to the cardiac cell. This Ca2+ influx would mainly occur by the coupled activation of the Na+ / H+ exchanger and the Na+ / Ca2+ exchanger working in the reverse mode, since phosphorylation of Thr17 was decreased by inhibition of these exchangers and not affected by blockade of the L-type Ca2+ channels. (3) Specific inhibition of CaMKII by KN93 significantly decreased Thr17 phosphorylation. This decrease was associated with an impairment of myocardial relaxation. The present study suggests that the phosphorylation of Thr17 of PLB upon reflow, may favor the full recovery of relaxation after ischemia. The sarcoplasmic reticulum (SR) plays a critical role in mediating cardiac contractility and its function is abnormal in the diabetic heart. However, the mechanisms underlying SR dysfunction in the diabetic heart are not clear. Because protein phosphorylation regulates SR function, this study examined the phosphorylation state of phospholamban, a key SR protein that regulates SR calcium (Ca2+) uptake in the heart. Diabetes was induced in male Sprague-Dawley rats by an injection of streptozotocin (STZ; 65 mg kg(-1) i.v.), and the animals were humanely killed after 6 weeks and cardiac SR function was examined. Depressed cardiac performance was associated with reduced SR Ca2+-uptake activity in diabetic animals. The reduction in SR Ca2+-uptake was consistent with a significant decrease in the level of SR Ca2+-pump ATPase (SERCA2a) protein. The level of phospholamban (PLB) protein was also decreased, however, the ratio of PLB to SERCA2a was increased in the diabetic heart. Depressed SR Ca2+-uptake was also due to a reduction in the phosphorylation of PLB by the Ca2+-calmodulin-dependent protein kinase (CaMK) and cAMP-dependent protein kinase (PKA). Although the activities of the SR-associated Ca2+-calmodulin-dependent protein kinase (CaMK), cAMP-dependent protein kinase (PKA) were increased in the diabetic heart, depressed phosphorylation of PLB could partly be attributed to an increase in the SR-associated protein phosphatase activities. These results suggest that there is increased inhibition of SERCA2a by PLB and this appears to be a major defect underlying SR dysfunction in the diabetic heart. Oligomeric interactions between Ca-ATPase polypeptide chains and their modulation by phospholamban (PLB) were measured in native cardiac sarcoplasmic reticulum (SR) microsomes. Progressive modification of Lys(514) with fluorescein 5-isothiocyanate (FITC), which physically blocks access to the nucleotide binding site by ATP, demonstrates that Ca-ATPase active sites function independently of one another prior to the phosphorylation of PLB. However, upon cAMP-dependent protein kinase (PKA) phosphorylation of PLB, a second-order dependence between residual enzyme activity and the fraction of active sites is observed, consistent with a dimeric functional complex. Complementary distance measurements were made using FITC or 5-iodoacetamidofluorescein (IAF) bound to Cys(674) within the N- or P-domains, respectively, to detect structural coupling within oligomeric complexes. Accompanying the phosphorylation of PLB, neighboring Ca-ATPase polypeptide chains exhibit a 4 +/- 2 A decrease in the proximity between FITC sites within the N-domain and a 9 +/- 3 A increase in the proximity between IAF sites within P-domains. Thus, the phosphorylation of PLB induces spatial rearrangements between the N- and P-domain elements of proximal Ca-ATPase polypeptide chains which restore functional interactions between neighboring polypeptide chains and, in turn, result in increased rates of catalytic turnover. These results are interpreted in terms of a structural model, calculated through optimization of shape complementarity, desolvation, and electrostatic energies, which suggests a dimeric arrangement of Ca-ATPase polypeptide chains through the proximal association of N-domains that accommodates interaction with PLB. We suggest that the phosphorylation of PLB acts to release constraints involving interdomain subunit interactions that enhance catalytically important N-domain motions. Although dilated cardiomyopathy (DCM) is known to result in cardiac contractile dysfunction, the underlying mechanisms are unclear. The sarcoplasmic reticulum (SR) is the main regulator of intracellular Ca2+ required for cardiac contraction and relaxation. We therefore hypothesized that abnormalities in both SR function and regulation will contribute to cardiac contractile dysfunction of the J2N-k cardiomyopathic hamster, an appropriate model of DCM. Echocardiographic assessment indicated contractile dysfunction, because the ejection fraction, fractional shortening, cardiac output, and heart rate were all significantly reduced in J2N-k hamsters compared with controls. Depressed cardiac function was associated with decreased cardiac SR Ca2+ uptake in the cardiomyopathic hamsters. Reduced SR Ca2+ uptake could be further linked to a decrease in the expression of the SR Ca(2+)-ATPase and cAMP-dependent protein kinase (PKA)-mediated phospholamban (PLB) phosphorylation at serine-16. Depressed PLB phosphorylation was paralleled with a reduction in the activity of SR-associated PKA, as well as an elevation in protein phosphatase activity in J2N-k hamster. The results of this study suggest that an alteration in SR function and its regulation contribute to cardiac contractile dysfunction in the J2N-k cardiomyopathic hamster. The status of phospholamban (PLB) phosphorylation in the ischemia-reperfused hearts remains controversial. Although a decrease in the phosphorylation of both PLB residues (Ser16, PKA site, and Thr17, CaMKII site) was previously reported, experiments from our laboratory failed to detect this decrease. In an attempt to elucidate the cause for this discrepancy, experiments were performed in Langendorff-perfused rat hearts with two main goals: (1) To determine whether keeping pacing during ischemia, a protocol followed in other ischemia-reperfusion models, decreases the phosphorylation of PLB residues, below pre-ischemic values; (2) To investigate whether a maximal beta-adrenergic challenge allows to detect a decrease in the ability of PLB to be phosphorylated in ischemia-reperfused hearts. Hearts were submitted to a global ischemia/reperfusion protocol (20/30 min) with (P) or without (NP) pacing during ischemia, and phosphorylation of PLB residues was assessed by immunodetection. The recovery of contractility upon reperfusion was lower in P vs. NP hearts. Ser16 of PLB, was phosphorylated at the end of ischemia in NP hearts. This increase appeared earlier in P hearts and was significantly diminished by catecholamine depletion and beta-blockade. Thr17 site was phosphorylated at the beginning of ischemia and the onset of reperfusion. The ischemia-induced phosphorylation of Thr17 was higher and more sustained in P vs. NP hearts, and inhibited by the calcium channel blocker, nifedipine, whereas the reperfusion-induced increase in Thr17 phosphorylation was similar in P and NP hearts and was significantly diminished by the Na+/Ca2+ exchanger inhibitor KB-R7943. Phosphorylation of PLB residues did not decrease below basal levels at any time during ischemia and reperfusion. However, the phosphorylation, inotropic and lusitropic response to beta-adrenergic stimulation was significantly decreased both in P and NP hearts. Phospholamban, the cardiac sarcoplasmic reticulum proteolipid, is phosphorylated by cAMP-dependent protein kinase, by Ca2+/phospholipid-dependent protein kinase, and by an endogenous Ca2+/calmodulin-dependent protein kinase, the identity of which remains to be defined. The aim of this study was therefore to characterize the latter kinase, called phospholamban kinase. Phospholamban kinase was purified approximately 42-fold with a yield of 11%. The purified fraction exhibits a specific activity of 6.5 nmol of phosphate incorporated into exogenous phospholamban per minute per milligram of protein. Phospholamban kinase appears to be a high molecular weight enzyme and presents a broad substrate specificity, synapsin-1, glycogen synthase, and smooth muscle myosin regulatory light chain being the best substrates. Phospholamban kinase phosphorylates synapsin-1 on a Mr 30 000 peptide. The enzyme exhibits an optimum pH of 8.6, a Km for ATP of 9 microM, and a requirement for Mg2+ ions. These data suggest that phospholamban kinase might be an isoenzyme of the multifunctional Ca2+/calmodulin-dependent protein kinase. Consequently we have searched for Mr 50 000-60 000 phosphorylatable subunits among cardiac sarcoplasmic reticulum proteins. A Mr 56 000 protein was found to be phosphorylated in the presence of Ca2+/calmodulin. Such phosphorylation alters the electrophoretic migration velocity of the protein. In addition, this protein that binds calmodulin was always found to be present in fractions containing phospholamban kinase activity. This Mr 56 000 protein is therefore a good candidate for being a subunit of phospholamban kinase. However, the Mr 56 000 calmodulin-binding protein and the Mr 53 000 intrinsic glycoprotein which binds ATP are two distinct entities.

Are there telemedicine applications for chronic pain management?

Yes, telemedicine is feasible and cost-effective for education and therapy of patients with chronic pain.

[17336868, 23291270, 23659470, 22662734, 16691087, 21375412, 22303839]

The under treatment of pain has been well documented. Contributing to this is the limited availability of pain management specialists in many geographic areas. The use of technology to provide care to underserved areas is gaining momentum. We chose to study whether stable patients and staff in chronic pain clinic were satified with the use of a videoconferencing format in care delivery. Our goals were to determine whether patients and staff could successfully operate the extant videoconferencing equipment, was the equipment dependably functional, was the use of a videoconferencing format an acceptable method of healthcare delivery for both patients and staff, whether patients and staff were satisfied with the process, and whether this was a cost-effective mode of care delivery. Thirty-six patients were enrolled over 29 months. Questionnaires were administered to staff and patients. Routine pain clinic patient assessment tools were administered. Results showed the use of videoconferencing for this group of patients is useable and satisfactory for both patients and staff, that the patients save time and money, and that for a system where videoconferencing equipment is already in use, it is also cost effective. Staff were able to identify new patient problems. Some patients would prefer to be seen in person but find that the savings in time and money override this preference. Hearing impaired patients have difficulty using this medium. Dependable equipment and phone connections are needed. A videoconferencing clinic format is a clinically acceptable and cost effective method for follow-up of stable patients with chronic pain. BACKGROUND: Internet-based interventions using cognitive behavioral approaches can be effective in promoting self-management of chronic pain conditions. Web-based programs delivered via smartphones are increasingly used to support the self-management of various health disorders, but research on smartphone interventions for persons with chronic pain is limited. OBJECTIVE: The aim of this trial was to study the efficacy of a 4-week smartphone-delivered intervention with written diaries and therapist feedback following an inpatient chronic pain rehabilitation program. METHODS: A total of 140 women with chronic widespread pain who participated in a 4-week inpatient rehabilitation program were randomized into 2 groups: with or without a smartphone intervention after the rehabilitation. The smartphone intervention consisted of 1 face-to-face session and 4 weeks of written communication via a smartphone. Participants received 3 smartphone diary entries daily to support their awareness of and reflection on pain-related thoughts, feelings, and activities. The registered diaries were immediately available to a therapist who submitted personalized written feedback daily based on cognitive behavioral principles. Both groups were given access to a noninteractive website after discharge to promote constructive self-management. Outcomes were measured with self-reported questionnaires. The primary outcome measure of catastrophizing was determined using the pain catastrophizing scale (score range 0-52). Secondary outcomes included acceptance of pain, emotional distress, functioning, and symptom levels. RESULTS: Of the 140 participants, 112 completed the study: 48 in the intervention group and 64 in the control group. Immediately after the intervention period, the intervention group reported less catastrophizing (mean 9.20, SD 5.85) than the control group (mean 15.71, SD 9.11, P<.001), yielding a large effect size (Cohen's d=0.87) for study completers. At 5-month follow-up, the between-group effect sizes remained moderate for catastrophizing (Cohen's d=0.74, P=.003), acceptance of pain (Cohen's d=0.54, P=.02), and functioning and symptom levels (Cohen's d=0.75, P=.001). CONCLUSIONS: The results suggest that a smartphone-delivered intervention with diaries and personalized feedback can reduce catastrophizing and prevent increases in functional impairment and symptom levels in women with chronic widespread pain following inpatient rehabilitation. TRIAL REGISTRATION: Clinicaltrials.gov NCT01236209; http://www.clinicaltrials.gov/ct2/show/NCT01236209 (Archived by WebCite at http://www.webcitation.org/6DUejLpPY). OBJECTIVE: Access to care has become a priority for the Veterans Administration (VA) health care system as a significant number of veterans enrolled in the VA health care system reside in rural areas. The feasibility and effects of a novel clinical intervention that combined group therapy and biofeedback training was evaluated on women veterans living in rural areas. METHODS: The study was conducted at selected community-based outpatient clinics (CBOCs) in Texas. Thirty four women veterans with chronic pain and comorbid depression and/or posttraumatic stress disorder (PTSD) were recruited. Five sessions of education/therapy were delivered via telemedicine in combination with daily home practice of a portable biofeedback device (Stress Eraser®, Helicor, New York, NY, USA). Participants responded to self-report questionnaires at baseline, at posttreatment, and at 6-week follow-up. Daily practice logs were also maintained by participants. RESULTS: The clinical protocol was acceptable, easy to administer, and associated with statistically significant decreases in self-reported pain unpleasantness, pain interference, depressive symptoms, PTSD symptoms, and sleep disturbance at posttreatment. Improvements were maintained at 6-week follow-up. Qualitative analyses indicated that many participants 1) wished to continue to meet as a support group in their respective CBOCs and 2) felt less isolated and more empowered to cope with their problems of daily living as a result of the treatment. CONCLUSIONS: It is feasible to provide treatment to women veterans living in rural areas by utilizing video-teleconferencing technology between larger VA medical centers and facilities at CBOCs in more rural settings. A controlled trial of the intervention is warranted. OBJECTIVES: Telemedicine has been used extensively in various settings, including monitoring patient treatment response and counseling. However, there are few data on the application of telemedicine to chronic pain patients. The present study was the first pilot project to determine whether telemedicine technology for chronic pain consultation was feasible, cost-saving, and satisfactory to patients and pain physicians. METHODS: A prospective pilot study was conducted on chronic pain patients requiring follow-up consultations using telemedicine technology. Patients were interviewed by phone following the consultation. RESULTS: Eleven telemedicine anesthesia consultations involving eight patients (age 42+/-9 years; six men, two women) were performed. All were follow-up consultations. The average distance from patients' home to the clinic was 314+/-170 km. The reasons for consultation were for update of patient progress (10/11), medication change (6/11), and counseling (3/11). The time to complete the consultation was 24.5+/-9.5 minutes. The data for the time and the cost that the patient spent on the consultation are presented as median and 25% to 75% interquartile range. Patients having telemedicine consultations spent 0.9 hours (0.83-1) and Canadian dollar 3 (dollar 2-4) versus an estimate of 8 hours (6-8) and Canadian dollar 80 (dollar 46-260) for a conventional consultation (both P<0.005). Telemedicine consultation was found to be highly satisfactory to the patient and the consulting and attending anesthesiologists. CONCLUSIONS: This pilot study indicates that telemedicine follow-up consultations for chronic pain patients are feasible and cost-saving. Patients and anesthesiologists were highly satisfied with telemedicine consultation. Patients reported a significant saving in time and cost compared with a conventional consultation. OBJECTIVE: Adapting therapeutic practice from traditional face-to-face exchange to remote technology-based delivery presents challenges for the therapist, patient, and technical writer. This article documents the process of therapy adaptation and the resultant specification for the SMART2 project-a technology-based self-management system for assisting long-term health conditions, including chronic pain. MATERIALS AND METHODS: Focus group discussions with healthcare professionals and patients were conducted to inform selection of therapeutic objectives and appropriate technology. RESULTS: Pertinent challenges are identified, relating to (1) reduction and definition of therapeutic objectives, and (2) how to approach adaptation of therapy to a form suited to technology delivery. The requirement of the system to provide dynamic and intelligent responses to patient experience and behavior is also emphasized. CONCLUSION: Solutions to these challenges are described in the context of the SMART2 technology-based intervention. More explicit discussion and documentation of therapy adaptation to technology-based delivery within the literature is encouraged. Pain is generally undertreated in the United States, owing to a number of barriers including geographic distance from specialty treatment providers; functional disability that limits mobility; treatment-related stigma; economic limitations; and educational barriers. Pain undertreatment exacerbates pain chronicity and emotional disruption that can significantly erode a pain patient's quality of life, and there is widespread agreement that pain care must evolve to address this significant problem. The growing field of telehealth (defined for the purposes of this paper as technology that allows for distance interaction between providers and/or patients) offers a novel opportunity to expand pain assessment, consultation, and treatment services beyond the walls of the specialty pain clinic, but there is limited availability of resources describing how to best use this technology to improve access to care. A recent literature review (September 2011) using universally endorsed MeSH search criteria revealed only 32 MEDLINE references focusing on telehealth for pain. This is surprising in light of the very large number of references covering telehealth (14,164 references) and pain (104,564 references), respectively. Of the studies available, there are very few randomized trials of telehealth pain care and only one general overview of e-health and chronic pain, which dedicates just a few paragraphs to telehealth. This manuscript represents one of the first comprehensive reviews of the current state of telehealth and pain management research and practice. The goals are to provide a rationale for the potential benefit of telehealth-based pain management services; describe the various applications of telehealth technology for pain management; orient the reader to cost models for telehealth; present examples of services in place; and offer recommendations for future research based on the current state of knowledge.

What is a P-body (processing body)?

Processing bodies (P bodies, PB) are cytoplasmic protein complexes involved in degradation and translational arrest of mRNA.

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In eukaryotic cells, non-translating mRNAs can accumulate into cytoplasmic mRNP (messenger ribonucleoprotein) granules such as P-bodies (processing bodies) and SGs (stress granules). P-bodies contain the mRNA decay and translational repression machineries and are ubiquitously expressed in mammalian cells and lower eukaryote species including Saccharomyces cerevisiae, Drosophila melanogaster and Caenorhabditis elegans. In contrast, SGs are only detected during cellular stress when translation is inhibited and form from aggregates of stalled pre-initiation complexes. SGs and P-bodies are related to NGs (neuronal granules), which are essential in the localization and control of mRNAs in neurons. Importantly, RNA granules are linked to the cytoskeleton, which plays an important role in mediating many of their dynamic properties. In the present review, we discuss how P-bodies, SGs and NGs are linked to cytoskeletal networks and the importance of these linkages in maintaining localization of their RNA cargoes. In eukaryotic cells, components of the 5' to 3' mRNA degradation machinery can undergo a rapid phase transition. The resulting cytoplasmic foci are referred to as processing bodies (P-bodies). The molecular details of the self-aggregation process are, however, largely undetermined. Herein, we use a bottom-up approach that combines NMR spectroscopy, isothermal titration calorimetry, X-ray crystallography, and fluorescence microscopy to probe if mRNA degradation factors can undergo phase transitions in vitro. We show that the Schizosaccharomyces pombe Dcp2 mRNA decapping enzyme, its prime activator Dcp1, and the scaffolding proteins Edc3 and Pdc1 are sufficient to reconstitute a phase-separation process. Intermolecular interactions between the Edc3 LSm domain and at least 10 helical leucine-rich motifs in Dcp2 and Pdc1 build the core of the interaction network. We show that blocking of these interactions interferes with the clustering behavior, both in vitro and in vivo. The localization of mRNA forms a key facet of the post-transcriptional control of gene expression and recent evidence suggests that it may be considerably more widespread than previously anticipated. For example, defined mRNA-containing granules can be associated with translational repression or activation. Furthermore, mRNA P-bodies (processing bodies) harbour much of the mRNA decay machinery and stress granules are thought to play a role in mRNA storage. In the present review, we explore the process of mRNA localization in the yeast Saccharomyces cerevisiae, examining connections between organellar mRNA localization and the response to stress. We also review recent data suggesting that even where there is a global relocalization of mRNA, the specificity and kinetics of this process can be regulated. Numerous mRNAs are degraded in processing bodies (P bodies) in Saccharomyces cerevisiae. In logarithmically growing cells, only 0-1 P bodies per cell are detectable. However, the number and appearance of P bodies change once the cell encounters stress. Here, we show that the polysome-associated mRNA-binding protein Scp160 interacts with P body components, such as the decapping protein Dcp2 and the scaffold protein Pat1, presumably, on polysomes. Loss of either Scp160 or its interaction partner Bfr1 caused the formation of Dcp2-positive structures. These Dcp2-positive foci contained mRNA, because their formation was inhibited by the presence of cycloheximide. In addition, Scp160 was required for proper P body formation because only a subset of bona fide P body components could assemble into the Dcp2-positive foci in Δscp160 cells. In either Δbfr1 or Δscp160 cells, P body formation was uncoupled from translational attenuation as the polysome profile remained unchanged. Collectively, our data suggest that Bfr1 and Scp160 prevent P body formation under normal growth conditions. Author information: (1)Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA. Electronic address: [email protected]. (2)Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA. (3)Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, MA 02115, USA; Department of Medicine, Harvard Medical School, Boston, MA 02115, USA. Electronic address: [email protected]. mRNA accumulation is tightly regulated by diverse molecular pathways. The identification and characterization of enzymes and regulatory proteins involved in controlling the fate of mRNA offers the possibility to broaden our understanding of posttranscriptional gene regulation. Processing bodies (P bodies, PB) are cytoplasmic protein complexes involved in degradation and translational arrest of mRNA. Composition and dynamics of these subcellular structures have been studied in animal systems, yeasts and in the model plant Arabidopsis. Their assembly implies the aggregation of specific factors related to decapping, deadenylation, and exoribonucleases that operate synchronously to regulate certain mRNA targets during development and adaptation to stress. Although the general function of PB along with the flow of genetic information is understood, several questions still remain open. This review summarizes data on the composition, potential molecular roles, and biological significance of PB and potentially related proteins in Arabidopsis. The mammalian target of rapamycin complex 1 (mTORC1) is involved in the cellular transcription and translation processes. The undertaken study characterized the enhancer of mRNA decapping protein 4 (Edc4) as mTORC1 interacting protein. Human T lymphoblast (CCRF-CEM) cells were used for mTORC1 purification. Co-immunoprecipitation coupled with immunoblotting analysis was used to confirm the interaction of Edc4 in mTORC1 specific purifications. Further assays were incorporated to conclude the role of mTORC1 in mRNA decapping via Edc4. Edc4 was identified as a new interacting protein with mTORC1 in both the endogenous and myc-tag raptor component mTORC1 specific purifications. Quantitative co-localization using confocal microscopy demonstrated that raptor component of mTORC1 coexists with Edc4 in processing (P) bodies, a site for mRNA degradation. Incubation of cells with rapamycin, a known inhibitor of mTOR kinase activity, increased the total Edc4 protein expression but at the same time decreased the Edc4 interaction with mTORC1. Moreover, rapamycin treatment resulted in a significant decrease in total serine phosphorylated Edc4 protein signal and the total 5'-capped mRNA. These findings provide the first evidence for the pivotal role of mTORC1 in Edc4 regulation. Further in-depth studies are required to get a complete understanding of molecular crosstalk between mTORC1 signaling and mRNA decapping pathway. Author information: (1)Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France. (2)Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, Luxembourg; National Center for Microscopy and Imaging Research, University of California San Diego, La Jolla, California, United States of America. (3)Institute for Systems Biology, Seattle, Washington, United States of America. (4)Tampere University of Technology, Pori, Finland; BioMediTech, University of Tampere, Tampere, Finland. (5)Physics and Bioengineering, University of Washington, Seattle, Washington, United States of America. (6)Centre for High-Throughput Biology, Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada. (7)Institute for Systems Biology, Seattle, Washington, United States of America; Molecular and Cellular Biology Program, University of Washington, Seattle, Washington, United States of America. (8)Molecular and Cellular Biology Program, University of Washington, Seattle, Washington, United States of America; Pacific Northwest Diabetes Research Institute, Seattle, Washington, United States of America. Processing bodies (P-bodies) are cytoplasmatic mRNP granules containing non-translating mRNAs and proteins from the mRNA decay and silencing machineries. The mechanism of P-body assembly has been typically addressed by depleting P-body components. Here we apply a complementary approach and establish an automated cell-based assay platform to screen for molecules affecting P-body assembly. From a unique library of compounds derived from myxobacteria, 30 specifically inhibited P-body assembly. Gephyronic acid A (GA), a eukaryotic protein synthesis inhibitor, showed the strongest effect. GA also inhibited, under stress conditions, phosphorylation of eIF2α and stress granule formation. Other hits uncovered interesting novel links between P-body assembly, lipid metabolism, and internal organelle physiology. The obtained results provide a chemical toolbox to manipulate P-body assembly and function. Serine/arginine-rich splicing factor 3 (SRSF3), a member of the serine/arginine (SR)-rich family of proteins, regulates both alternative splicing of pre-mRNA and export of mature mRNA from the nucleus. Although its role in nuclear mRNA processing is well understood, the mechanism by which it alters the fate of cytoplasmic mRNA molecules remains elusive. Here, we provide evidence that SRSF3 not only regulates the alternative splicing pattern of programmed cell death 4 (PDCD4) mRNA, but also modulates its translational efficiency in the cytoplasm by lowering translation levels. We observed a marked increase in PDCD4 mRNA in translating polysome fractions upon silencing of SRSF3, and, conversely, ectopic overexpression of SRSF3 shifted PDCD4 mRNA into non-translating ribosomal fractions. In live cells, SRSF3 colocalized with PDCD4 mRNA in P-bodies (PBs), where translationally silenced mRNAs are deposited, and this localization was abrogated upon SRSF3 silencing. Furthermore, using two different reporter systems, we showed that SRSF3 interacts directly with PDCD4 mRNA and mediates translational repression by binding to the 5'-untranslated region (5'-UTR). In summary, our data suggest that the oncogenic potential of SRSF3 might be realized, in part, through the translational repression of PDCD4 mRNA. The decapping enzymes DCP1 and DCP2 are components of a decapping complex that degrades mRNAs. DCP2 is the catalytic core and DCP1 is an auxiliary subunit. It has been assumed that DCP1 and DCP2 are consistently co-localized in cytoplasmic RNA granules called processing bodies (P-bodies). However, it has not been confirmed whether DCP1 and DCP2 co-localize in Arabidopsis thaliana. In this study, we generated DCP1-green fluorescent protein (GFP) and DCP2-GFP transgenic plants that complemented dcp1 and dcp2 mutants, respectively, to see whether localization of DCP2 is identical to that of DCP1. DCP2 was present throughout the cytoplasm, whereas DCP1 formed P-body-like foci. Use of DCP1-GFP/DCP2-red fluorescent protein (RFP) or DCP1-RFP/DCP2-GFP plants showed that heat treatment induced DCP2 assembly into DCP1 foci. In contrast, cold treatment did not induce DCP2 assembly, while the number of DCP1 foci increased. These changes in DCP1 and DCP2 localization during heat and cold treatments occurred without changes in DCP1 and DCP2 protein abundance. Our results show that DCP1 and DCP2 respond differently to environmental changes, indicating that P-bodies have diverse DCP1 and DCP2 proportions depending on environmental conditions. The localization changes of DCP1 and DCP2 may explain how specific mRNAs are degraded during changes in environmental conditions. During cell stress, the transcription and translation of immediate early genes are prioritized, while most other messenger RNAs (mRNAs) are stored away in stress granules or degraded in processing bodies (P-bodies). TIA-1 is an mRNA-binding protein that needs to translocate from the nucleus to seed the formation of stress granules in the cytoplasm. Because other stress granule components such as TDP-43, FUS, ATXN2,SMN, MAPT, HNRNPA2B1, and HNRNPA1 are crucial for the motor neuron diseases amyotrophic lateral sclerosis (ALS)/spinal muscular atrophy (SMA) and for the frontotemporal dementia(FTD), here we studied mouse nervous tissue to identify mRNAs with selective dependence on Tia1 deletion. Transcriptome profiling with oligonucleotide microarrays in comparison of spinal cord and cerebellum, together with independent validation in quantitative reverse transcriptase PCR and immunoblots demonstrated several strong and consistent dysregulations. In agreement with previously reported TIA1 knock down effects, cell cycle and apoptosis regulators were affected markedly with expression changes up to +2-fold, exhibiting increased levels for Cdkn1a, Ccnf, and Tprkb vs.decreased levels for Bid and Inca1 transcripts. Novel and surprisingly strong expression alterations were detected for fat storage and membrane trafficking factors, with prominent +3-fold upregulations of Plin4, Wdfy1, Tbc1d24, and Pnpla2 vs. a −2.4-fold downregulation of Cntn4 transcript, encoding an axonal membrane adhesion factor with established haploinsufficiency.In comparison, subtle effects on the RNA processing machinery included up to 1.2-fold upregulations of Dcp1b and Tial1. The effect on lipid dynamics factors is noteworthy, since also the gene deletion of Tardbp (encoding TDP-43) and Atxn2 led to fat metabolism phenotypes in mouse. In conclusion, genetic ablation of the stress granule nucleator TIA-1 has a novel major effect on mRNAs encoding lipid homeostasis factors in the brain, similar to the fasting effect. Processing (P)-bodies are cytoplasmic RNA protein aggregates responsible for the storage, degradation, and quality control of translationally repressed messenger RNAs in eukaryotic cells. In mammals, P-body-related RNA and protein exchanges are actomyosin dependent, whereas P-body movement requires intact microtubules. In contrast, in plants, P-body motility is actin based. In this study, we show the direct interaction of the P-body core component DECAPPING PROTEIN1 (DCP1) with the tails of different unconventional myosins in Arabidopsis (Arabidopsis thaliana). By performing coexpression studies with AtDCP1, dominant-negative myosin fragments, as well as functional full-length myosin XI-K, the association of P-bodies and myosins was analyzed in detail. Finally, the combination of mutant analyses and characterization of P-body movement patterns showed that myosin XI-K is essential for fast and directed P-body transport. Together, our data indicate that P-body movement in plants is governed by myosin XI members through direct binding to AtDCP1 rather than through an adapter protein, as known for membrane-coated organelles. Interspecies and intraspecies interaction approaches with mammalian and yeast protein homologs suggest that this mechanism is evolutionarily conserved among eukaryotes. The localization of mRNA to defined cytoplasmic sites in eukaryotic cells not only allows localized protein production but also determines the fate of mRNAs. For instance, translationally repressed mRNAs localize to P-bodies and stress granules where their decay and storage, respectively, are directed. Here, we find that several mRNAs are localized to granules in unstressed, actively growing cells. These granules play a key role in the stress-dependent formation of P-bodies. Specific glycolytic mRNAs are colocalized in multiple granules per cell, which aggregate during P-body formation. Such aggregation is still observed under conditions or in mutants where P-bodies do not form. In unstressed cells, the mRNA granules appear associated with active translation; this might enable a coregulation of protein expression from the same pathways or complexes. Parallels can be drawn between this coregulation and the advantage of operons in prokaryotic systems.

What is the mechanism of action of decitabine?

Decitabine reactivates unmethylated p21WAF1 in some AML cell lines but the possible occurrence of p21WAF1 methylation in AML in vivo has not been studied in detail and decitabine effects on p21WAF1 chromatin remodeling have not been reported. We also discuss the following questions: What is the best administration schedule of decitabine in solid tumors? Is there tumor type specificity for decitabine-based epigenetic therapy? We found that p21WAF1 mRNA was undetectable in 6 of 24 AML patient samples and 4 of 5 AML cell lines but there was no evidence of p21WAF1 promoter methylation.

[16273408, 22893792, 25123082, 16585166, 16043219, 24286424, 16211386, 25130173]

Recent evidence demonstrates that epigenetic silencing of genes is associated with myelodysplasia and that a worse prognosis may be correlated with hypermethylation of certain genes, such as the cyclin-dependent kinase inhibitor p15. 5-Aza-2'-deoxycytidine (decitabine, DAC) is a nucleoside analog, which, at low doses, acts as a hypomethylating agent and is fivefold to tenfold more active than 5-azacytidine (azacitidine, Vidaza)--currently the only approved drug for treatment of myelodysplastic syndrome (MDS). Clinical studies have demonstrated that decitabine has activity in patients with MDS. Preliminary results of a phase III multicenter North American trial comparing low-dose decitabine to supportive care verified that therapy with decitabine resulted in higher response rates, improved quality of life, and prolonged time to leukemic transformation and/or death. However, further elucidation of its mechanism of action is required, as clinical response to decitabine does not correlate with demethylation of the p15 gene promoter or the repetitive DNA element LINE. Decitabine appears to upregulate both hypermethylated and nonmethylated genes. Ongoing studies aim to determine the optimal dose, schedule, and route of administration of decitabine, and to evaluate whether efficacy can be improved by using it in combination with other agents, such as histone deacetylase inhibitors. We have previously demonstrated proteasomal degradation of DNMT1 in mammalian cells following treatment with several DNA hypomethylating agents. Here, we demonstrate dose-dependent degradation of Dnmt1 in mouse embryonic stem (ES) cells expressing catalytic site mutant (cys-ser), confirming that the covalent bond formation between Dnmt1 and decitabine-incorporated DNA is not essential for this process. DNMT1o, the oocyte-specific isoform that lacks the N-terminal 118-amino acid domain, did not undergo decitabine-mediated degradation, which further proves the requirement of multiple domains including nuclear localization signal, KEN box, and BAH domains for this process. Analysis of glycerol density gradient fractions of micrococcal nuclease-digested nuclei showed that both nucleosomal and nucleoplasmic DNMT1 are degraded upon decitabine treatment. Among different inhibitors tested, the inhibitors of the proteasomal pathway and several protein kinases impeded decitabine-induced DNMT1 degradation. The maximal effect caused by inhibiting protein kinase C (PKC) persuaded us to investigate further its role in decitabine-mediated DNMT1 degradation. Blockage of the degradation process after treatment with rottlerin, an inhibitor of PKCδ, or after siRNA-mediated depletion of PKCδ, indicated that this protein kinase is involved in decitabine-mediated depletion of DNMT1. PKCδ interacted with and phosphorylated DNMT1 in vitro. Moreover, rottlerin inhibited both basal and decitabine-induced phosphorylation of DNMT1. These studies provide substantial evidence that decitabine-induced degradation of the maintenance methyltransferase DNMT1 does not require covalent bond formation with the substrate and also elucidate its underlying molecular mechanism. Decitabine, a demethylating drug, is the first-line treatment for myelodysplastic syndromes and gains better overall survival, which is based on epigenetic mechanism. Activated by promoter demethylation, melanoma-associated antigens-A (MAGE-A), cancer-testis antigens are attractive targets for immunotherapy. Our purpose was to investigate whether decitabine could show anti-tumor effects for esophageal cancer and explore its mechanism. In addition, we aimed to examine its modulation for most MAGE-A members. The results showed the baseline expression were MAGE-A2, -3,-9, and -10 in Eca109 cells and decitabine (0.5 μM) could induce MAGE-A8 and -A4 whereas reduce MAGE-A9 and -A10. Moreover, decitabine (0.5 μM) inhibited cell proliferation, migration and invasive ability by 15%, 34% and 47.2%, respectively and decreased expressions of NF-κB2 and MMP2. Our results demonstrated that low-dose decitabine induced the expression of MAGE-A8 and -A4, and inhibited cell invasion through decreasing expression of MMP2 and NF-κB2, which provides possibilities for combing decitabine with immunotherapy targeting MAGE-A to treat advanced esophageal squamous cell carcinoma. Progress on several unresolved issues in cancer epigenetics will benefit from rapid and standardized methods for profiling DNA methylation genome-wide. In the area of epigenetic therapy, the demethylating drug decitabine (5-aza-2'-deoxycytidine) is increasingly used to treat acute myelogenous leukemia and myelodysplastic syndrome, but the mechanisms of its anticancer activity have remained unclear. Given the clinical efficacy of decitabine and the uncertainties about its mode of action, it will be useful to optimize methods for following DNA methylation as a biochemical response in individual patients. Here, we describe a single nucleotide polymorphism (SNP) chip-based method (MSNP) for profiling DNA methylation. Using this procedure, the extent of demethylation in bone marrow aspirates from patients with leukemia receiving decitabine can be assessed genome-wide using commercially available (Affymetrix) SNP chips. We validated the accuracy of MSNP by comparing the results with combined bisulfite restriction analysis and by sequencing cloned PCR products from bisulfite-converted DNA. We further validated MSNP in a Wilms' tumor/normal kidney comparison, comparing the results with methylation-sensitive Southern blotting. MSNP simultaneously detects aberrations in DNA copy number and loss of heterozygosity, making it a generally useful approach for combined genetic and epigenetic profiling in tissue samples from cancer patients. Decitabine is a potent demethylating agent that exhibits clinical activity against myeloid malignancies. Numerous genes silenced by hypermethylation are reactivated by decitabine through a mechanism involving promoter demethylation with subsequent release of histone deacetylases (HDACs) and accumulation of acetylated histones. Recent studies indicating that decitabine also induces regional chromatin remodeling of some unmethylated genes suggest additional mechanisms of action. Decitabine reactivates unmethylated p21WAF1 in some AML cell lines but the possible occurrence of p21WAF1 methylation in AML in vivo has not been studied in detail and decitabine effects on p21WAF1 chromatin remodeling have not been reported. We found that p21WAF1 mRNA was undetectable in 6 of 24 AML patient samples and 4 of 5 AML cell lines but there was no evidence of p21WAF1 promoter methylation. However, decitabine induced p21WAF1 in AML cell lines KG-1 and KG-1a in association with release of HDAC1 and increased acetylated histone H3 at the unmethylated p21WAF1 promoter. Decitabine effects on p21WAF1 histone acetylation and induction were enhanced by the HDAC inhibitor trichostatin A and were independent of wild type p53. Our findings indicate that decitabine can relieve p21WAF1 repression in AML by a mechanism that involves release of HDAC1 without requiring promoter demethylation. Furthermore, our study provides evidence that combined decitabine and HDAC inhibitor treatment can enhance chromatin remodeling and reactivation of an unmethylated tumor suppressor gene. This latter finding is of relevance to the clinical use of these agents in AML as we found the p21WAF1 promoter to be unmethylated in vivo. BACKGROUND: Cancer testis antigens (CTAs) are a novel group of tumor associated antigens. Demethylating agent decitabine was reported to be able to up-regulate CTAs through its hypomethylation mechanism, thus enhance the immunogenicity of leukemia cells. However, few researches have ever focused on the questions that whether this immunostimulatory effect of decitabine could induce autologous CTA specific cytotoxic T lymphocytes (CTLs) in vivo, and if so, whether this effect contributes to disease control. In this study, we aimed to show that decitabine could induce specific autologous CTLs against some mouse CTAs in leukemia cells in vitro and in vivo. METHODS: Several mouse CTAs were screened by RT-PCR. CTL specific to one of the CTAs named P1A was detected and sorted by P1A specific dimer by flow cytometry. The activity of specific CTLs was measured by real time RT-PCR. RESULTS: We firstly screened expression of some CTAs in mouse leukemia cells before and after decitabine treatment and found that decitabine treatment did up-regulate expression of many CTAs. Then we measured the CTLs' activity specific to a mouse CTA P1A in vivo and showed that this activity increased after decitabine treatment. Finally, we sorted these in vivo induced P1A specific CTLs by flow cytometry and demonstrated their cytotoxicity against decitabine treated leukemia cells. CONCLUSIONS: Our study showed the autologous immune response induced by decitabine in vivo. And more importantly, we firstly proved that this response may contribute to disease control. We believe that this immunostimulatory effect is another anti-cancer mechanism of decitabine, and this special effect would inspire new applications of decitabine in the field of leukemia treatment in the future. During the last 10 years, three European phase II studies were performed to investigate the treatment of elderly patients with myelodysplastic syndrome (MDS) with low-dose 5-aza-2'-deoxycytidine (decitabine, DAC). All these European trial data were reviewed on the basis of the International Prognostic Scoring System (IPSS) risk criteria and the response criteria as recently published by an international working group. To investigate the results in a larger cohort of patients and to determine risk factors, all data were pooled with some observations from the PCH 95-06 US phase II study. The response rate in the 177 patients evaluated (median age 70 years) was 49%. The median response duration was 36 weeks, and the median survival was 15 months. Analysis of the data according to sex, age, French-American-British classification, percentage of blasts in the bone marrow, IPSS risk group, lactate dehydrogenase and cytogenetics did not reveal any factor predictive of response. Overall, 69% of patients benefited, including those with stable disease during therapy. Response duration was significantly shorter with increasing risk (according to the IPSS classification). Haemoglobin level and neutrophil count showed an inverse correlation to the IPSS classification. Univariate analysis showed a significantly inferior survival for elderly patients (>75 years of age) and for those with high levels of serum lactate dehydrogenase (LDH) (more than two times the normal values). Patients with high-risk cytogenetic abnormalities according to the IPSS risk criteria showed better overall survival than those with intermediate-risk abnormalities. When analysed according to the IPSS risk classification, high-risk patients had worse survival prospects following decitabine therapy than those with intermediate risk; however, compared to the originally reported IPPS outcomes for high-risk patients, they probably showed better survival. During the treatment period, 18% of the patients progressed towards acute leukaemia. Decitabine showed a rather low toxicity profile in this elderly patient group. In conclusion, low-dose decitabine is an active drug for the treatment of MDS patients, even for those older than 75 years with bad prognostic characteristics.

Which gene is associated with the Mitchell-Riley syndrome?

Mutations in the gene coding for the transcription factor RFX6 (regulatory factor X,6) have been described as the cause of the Mitchell-Riley syndrome.

[21215266, 23914949]

Recently, bi-allelic mutations in the transcription factor RFX6 were described as the cause of a rare condition characterized by neonatal diabetes with pancreatic and biliary hypoplasia and duodenal/jejunal atresia. A male infant developed severe hyperglycemia (446 mg/dL) within 24 h of birth. Acute abdominal concerns by day five necessitated exploratory surgery that revealed duodenal atresia, gallbladder agenesis, annular pancreas and intestinal malrotation. He also exhibited chronic diarrhea and feeding intolerance, cholestatic jaundice, and subsequent liver failure. He died of sepsis at four months old while awaiting liver transplantation. The phenotype of neonatal diabetes with intestinal atresia and biliary agenesis clearly pointed to RFX6 as the causative gene; indeed, whole exome sequencing revealed a novel homozygous RFX6 mutation c.779A>C; p.Lys260Thr (K260T). This missense mutation also changes the consensus 5' splice donor site before intron 7 and is thus predicted to cause disruption in splicing. Both parents, who were not known to be related, were heterozygous carriers. Targeted genetic testing based on consideration of phenotypic features may reveal a cause among the many genes now associated with heterogeneous forms of monogenic neonatal diabetes. Our study demonstrates the feasibility of using modern sequencing technology to identify one such rare cause. Continued research is needed to determine the possible cost-effectiveness of this approach, especially when clear phenotypic clues are absent. Further study of patients with RFX6 mutations should clarify its role in pancreatic, intestinal and enteroendocrine cellular development and explain features such as the diarrhea exhibited in our case.

Is paramyxovirus involved in human subacute thyroiditis?

There is no evidence that paramyxovirus are involved in etiology of subacute thyroiditis.

[1691523, 9797, 20960165, 22459018, 16279854, 2998895, 1180050, 20886354, 806773, 22819125, 9637274]

New data on viruses isolated from patients with subacute thyroiditis de Quervain are reported. Characteristic morphological, cytological, some physico-chemical and biological features of the isolated viruses are described. A possible role of these viruses in human and animal health disorders is discussed. The isolated viruses remain unclassified so far. We describe a case of quick recovery of myocardium damage in a 15-year-old adolescent with subacute thyroiditis. After 1 week of admission, his cardiovascular status began to show signs of improvement accompanied by the recovery of electrocardiogram and indicators of myocardial damage. We speculate that myocardium damage associated with subacute thyroiditis is a complication of common virus, although we did not detect any abnormal virus antibody and deoxyribonucleic acid in the patient's serum. Subacute thyroiditis is a rare disease in childhood and is considered postviral in origin. Epstein-Barr virus (EBV) involvement has been suspected, but just once demonstrated in an adult female. We report a case of subacute thyroiditis during infectious mononucleosis in a 3-year-old girl. The diagnosis of infectious mononucleosis was supported, in addition to the typical clinical symptoms, by presence of EBV DNA both in plasma and leukocytes. Subacute thyroiditis was diagnosed based on elevated thyroid hormone levels with thyrotropin (TSH) suppression, high inflammation markers and almost absent (99)TC uptake by thyroid. Moreover after 3 months from diagnosis thyroid function went back to normal as well as the (99)TC uptake. The author experienced a case of subacute thyroiditis (de Quervain) in a 36-year-old female. Electron microscopic examination of the thyroid tissue of the patient revealed virus-like particles (VLP) in the degenerated follicular epithelium Judging from the size, the VLP corresponded to the influenza or mumps virus. de Quervain thyroiditis, also known as subacute thyroiditis, is a self-limited inflammatory disease of the thyroid gland. It is extremely rare in children. The hallmarks for diagnosis are painful thyroid enlargement, elevated inflammatory markers, and decreased uptake of the thyroid gland on thyroid scintigraphy. Viral infection has been proposed to be associated with de Quervain thyroiditis. Coxsackie virus has been reported to be one of the viruses associated with the disease. To our knowledge, childhood de Quervain thyroiditis associated with hand-foot-mouth disease caused by coxsackie infection has never been reported. We report a 2.7-year-old boy who presented with typical features of de Quervain thyroiditis following hand-foot-mouth disease caused by coxsackie B4 infection. He had a brief thyrotoxic phase initially, followed by transient hypothyroid phase and euthyroidism thereafter. His thyroid scintigraphy showed a typical faint uptake at the diagnosis, and an improvement of the thyroid scan and uptake was shown 8 weeks later. He was treated with prednisolone and nearly complete resolution was documented within 2 months. Careful evaluation of the patient led to the correct diagnosis and appropriate management. Virological and serological methods were used in examination of 28 patients suffering from subacute thyroiditis de Quervain. Attempts to isolate a presumed viral agent from 8 patients were performed by inoculation of serum, urine, and aspiration biopsies of thyroid glands taken at different stages of the illness, into tissue cultures of different types of human and animal cells. Recovery of a cytopathic viral agent on cells of a rabbit lung continuous line was successful in 5 cases. Serological cross reactions exist between the isolated viruses and patient serum but not with serum of healthy people. Cases with the acquired illness and positive antibodies against the isolated viruses who had been in close and prolonged contact with patients suffering from subacute thyroiditis de Quervain were also investigated. Subacute (de Quervain's) thyroiditis is a rare but important cause of fever of unknown origin. Most cases of subacute thyroiditis are caused by a variety of viruses, for example, Coxsackie, cytomegalovirus, Epstein-Barr virus, and adenovirus. Influenza immunization or infection may cause subacute thyroiditis. We present the first reported case of a fever of unknown origin due to seasonal influenza A in a 67-year-old woman. The etiology of subacute granulomatous thyroiditis (SAT) is obscure, although it is postulated to be associated with viral infections and genetic factors. In the present study, the possibility of an infectious etiology was prospectively studied in 27 consecutive patients with SAT. Special emphasis was put on the role of enteroviruses. Coupled sera (interval one month) were taken from all patients and single sera from 29 control subjects for virus antibody determinations. Stool samples were collected for virus isolation and fine-needle aspiration samples from thyroid gland for the detection of enterovirus RNA using RT-PCR were taken from SAT patients. Enteroviral antibodies were tested using three different methods: indirect EIA, heavy chain capture RIA, and standard complement fixation (CF) test. Antibodies against other common viral pathogens, including enteroviruses, were screened using the CF test and those against Mycoplasma pneumoniae and Chlamydia pneumoniae using EIA and microimmunofluorescence techniques, respectively. Common respiratory viruses were also screened from nasopharyngeal suction samples by antigen detection EIA. Based on serological findings, one patient had acute Cytomegalovirus infection. All other patients were negative in antibody tests, virus isolation, RT-PCR, and antigen detection. Enterovirus RNA was not detected by PCR in the thyroid tissue in any of the fine-needle aspiration samples. There was no evidence of recent enteroviral infections in SAT patients. The results suggest that SAT is not usually associated with acute infections. No evidence was obtained to support the proposed role of enteroviruses as an important etiologic agent of SAT.

What are the mobile applications fields of use for patients ?

Weight-loss mobile applications pediatric obesity prevention and treatment, healthy eating, and physical activity promotion A total of 229 dermatology-related apps were identified in the following categories: general dermatology reference (61 [26.6%]), self-surveillance/diagnosis (41 [17.9%]), disease guide (39 [17.0%]), educational aid (20 [8.7%]), sunscreen/UV recommendation (19 [8.3%]), calculator (12 [5.2%]), teledermatology (8 [3.5%]), conference (6 [2.6%]), journal (6 [2.6%]), photograph storage/sharing (5 [2.2%]), dermoscopy (2 [0.9%]), pathology (2 [0.9%]), and other (8 [3.5%]). The most reviewed apps included Ultraviolet ~ UV Index (355 reviews), VisualDx (306), SPF (128), iSore (61), and SpotMole (50) mobile health and fitness app alcohol-use behavior change or recovery More than 17,000 mHealth apps now are available for smart phones and other devices, and they do everything from monitoring urine flow for patients with enlarged prostates to reminding people prone to kidney stones to drink more water.

[24073184, 23821609, 21591562, 24067948, 22942063, 24139770, 21689119]

Mobile applications (apps) offer a novel way to engage children in behavior change, but little is known about content of commercially available apps for this population. We analyzed the content of apps for iPhone/iPad for pediatric weight loss, healthy eating (HE), and physical activity (PA). Fifty-seven apps were downloaded and tested by two independent raters. Apps were coded for: inclusion of the Expert Committee for Pediatric Obesity Prevention's (ECPOP) eight recommended strategies (e.g., set goals) and seven behavioral targets (e.g., do ≥1 h of PA per day), utilization of gaming elements, and general characteristics. Most apps lacked any expert recommendations (n = 35, 61.4 %). The mean number of recommendations among apps that used recommendations was 3.6 ± 2.7 out of 15, 56.1 % (n = 32) apps were classified as games, and mean price per app was $1.05 ± 1.66. Most apps reviewed lacked expert recommendations and could be strengthened by addition of comprehensive information about health behavior change and opportunities for goal setting. IMPORTANCE: With advancements in mobile technology, cellular phone-based mobile applications (apps) may be used in the practice and delivery of dermatologic care. OBJECTIVE: To identify and categorize the variety of current mobile apps available in dermatology for patients and providers. DESIGN, SETTING, AND PARTICIPANTS: Dermatology-related search terms were queried in the online app stores of the most commonly used mobile platforms developed by Apple, Android, Blackberry, Nokia, and Windows. Applications were assigned to categories based on description. Popularity, price, and reviews were recorded and target audiences were determined through websites offering online mobile apps. MAIN OUTCOMES AND MEASURES: Number, type, and price of mobile apps in dermatology. RESULTS: A total of 229 dermatology-related apps were identified in the following categories: general dermatology reference (61 [26.6%]), self-surveillance/diagnosis (41 [17.9%]), disease guide (39 [17.0%]), educational aid (20 [8.7%]), sunscreen/UV recommendation (19 [8.3%]), calculator (12 [5.2%]), teledermatology (8 [3.5%]), conference (6 [2.6%]), journal (6 [2.6%]), photograph storage/sharing (5 [2.2%]), dermoscopy (2 [0.9%]), pathology (2 [0.9%]), and other (8 [3.5%]). The most reviewed apps included Ultraviolet ~ UV Index (355 reviews), VisualDx (306), SPF (128), iSore (61), and SpotMole (50). There were 209 unique apps, with 17 apps existing on more than 1 operating system. More than half of the apps were offered free of charge (117 [51.1%]). Paid apps (112 [48.9%]) ranged from $0.99 to $139.99 (median, $2.99). Target audiences included patient (117 [51.1%]), health care provider (94 [41.0%]), and both (18 [7.9%]). CONCLUSIONS AND RELEVANCE: The widespread variety and popularity of mobile apps demonstrate a great potential to expand the practice and delivery of dermatologic care. Smartphones and tablets are slowly but steadily changing the way we look after our health and fitness. Today, many high quality mobile apps are available for users and health professionals and cover the whole health care chain, i.e. information collection, prevention, diagnosis, treatment and monitoring. Our team has developed a mobile health and fitness app called myFitnessCompanion® which has been available via Android market since February 2011. The objective of this paper is to share our experience with rolling out a mobile health and fitness app. We discuss the acceptance of health apps by end-users and healthcare industry. We discuss how mobile health apps will be distributed in the near future, the use of Personal Health Record (PHR) systems such as Microsoft HealthVault and the impact of regulations (FDA) on the future of mobile health apps. The paper is based on seven years of experience by the authors as mobile health and fitness application developers and we discuss the challenges and opportunities for app developers in the health industry. BACKGROUND: Physicians have limited time for weight-loss counseling, and there is a lack of resources to which they can refer patients for assistance with weight loss. Weight-loss mobile applications (apps) have the potential to be a helpful tool, but the extent to which they include the behavioral strategies included in evidence-based interventions is unknown. PURPOSE: The primary aims of the study were to determine the degree to which commercial weight-loss mobile apps include the behavioral strategies included in evidence-based weight-loss interventions, and to identify features that enhance behavioral strategies via technology. METHODS: Thirty weight-loss mobile apps, available on iPhone and/or Android platforms, were coded for whether they included any of 20 behavioral strategies derived from an evidence-based weight-loss program (i.e., Diabetes Prevention Program). Data on available apps were collected in January 2012; data were analyzed in June 2012. RESULTS: The apps included on average 18.83% (SD=13.24; range=0%-65%) of the 20 strategies. Seven of the strategies were not found in any app. The most common technology-enhanced features were barcode scanners (56.7%) and a social network (46.7%). CONCLUSIONS: Weight-loss mobile apps typically included only a minority of the behavioral strategies found in evidence-based weight-loss interventions. Behavioral strategies that help improve motivation, reduce stress, and assist with problem solving were missing across apps. Inclusion of additional strategies could make apps more helpful to users who have motivational challenges. BACKGROUND: Interactive and mobile technologies (i.e., smartphones such as Blackberries, iPhones, and palm-top computers) show promise as an efficacious and cost-effective means of communicating health-behavior risks, improving public health outcomes, and accelerating behavior change. The present study was conducted as a "needs assessment" to examine the current available mobile smartphone applications (e.g., apps) that utilize principles of ecological momentary assessment (EMA)-daily self-monitoring or near real-time self-assessment of alcohol-use behavior-to promote positive behavior change, alcohol harm reduction, psycho-education about alcohol use, or abstinence from alcohol. METHODS: Data were collected and analyzed from iTunes for Apple iPhone(©) . An inventory assessed the number of available apps that directly addressed alcohol use and consumption, alcohol treatment, or recovery, and whether these apps incorporated empirically based components of alcohol treatment. RESULTS: Findings showed that few apps addressed alcohol-use behavior change or recovery. Aside from tracking drinking consumption, a minority utilized empirically based components of alcohol treatment. Some apps claimed they could serve as an intervention; however, no empirical evidence was provided. CONCLUSIONS: More studies are needed to examine the efficacy of mobile technology in alcohol intervention studies. The large gap between availability of mobile apps and their use in alcohol treatment programs indicates several important future directions for research.

Is there any link between the aurora B kinase and the polycomb protein ring1B?

Yes. The aurora B kinase and the polycomb protein ring1B combine to regulate active promoters in quiescent lymphocytes.

[24034696]

Reversible cellular quiescence is critical for developmental processes in metazoan organisms and is characterized by a reduction in cell size and transcriptional activity. We show that the Aurora B kinase and the polycomb protein Ring1B have essential roles in regulating transcriptionally active genes in quiescent lymphocytes. Ring1B and Aurora B bind to a wide range of active promoters in resting B and T cells. Conditional knockout of either protein results in reduced transcription and binding of RNA Pol II to promoter regions and decreased cell viability. Aurora B phosphorylates histone H3S28 at active promoters in resting B cells as well as inhibiting Ring1B-mediated ubiquitination of histone H2A and enhancing binding and activity of the USP16 deubiquitinase at transcribed genes. Our results identify a mechanism for regulating transcription in quiescent cells that has implications for epigenetic regulation of the choice between proliferation and quiescence.

Which are the genes responsible for Dyskeratosis Congenita?

To date, 8 genes have been associated with Dyskeratosis Congenita development. These are DKC1, TERC, TERT, NOP10, NHP2, TIN2, C16orf57, and TCAB1. Seven of these are important in telomere maintenance, because either they encode components of the telomerase enzyme complex (DKC1, TERC, TERT, NOP10, NHP2, and TCAB1) or the shelterin complex (TINF2).

[10903840, 21199492, 9886310, 9863595, 15842668, 22160078, 20301779, 20687509, 15304085, 19419704, 18989882]

Mutations in the DKC1 gene are responsible for causing X-linked recessive dyskeratosis congenita (DKC) and a more severe allelic variant of the disease, Hoyeraal-Hreidarsson syndrome. Both diseases are characterized by progressive and fatal bone marrow failure. The nucleolar protein dyskerin is the pseudouridine synthase component of the box H+ACA snoRNAs and also interacts with the RNA component (human telomerase, hTR) of the telomerase complex. Dyskerin is therefore thought to function in the processing of pre-rRNA and of the hTR, strengthening the notion that the underlying mechanism of DKC is a premature senescence of cells, especially of the rapidly dividing epithelial and hemopoietic cells. To examine the functions of dyskerin in vivo, it will be necessary to generate mouse models. As a first step, we here provide the genomic structure of the mouse Dkc1 gene and expression analysis of the transcript. Northern hybridizations revealed the tissue-specific expression of an alternative 4.5-kb transcript, in addition to the ubiquitous 2.6-kb transcript. RNA in situ hybridizations on day 10.5-18.5 postconception embryos showed a ubiquitous expression of Dkc1 with a notably higher level of expression confined to the epithelial tissues. In addition, higher level Dkc1 expression was confined to embryonic neural tissues as well as to specific neurons in the cerebellum (Purkinje cells) and the olfactory bulb (mitral cells) of the adult brain. In adult testis, elevated expression was limited to the Leydig cells. The results indicate that some of the pertinent functions of dyskerin may be more tissue-specific than previously thought and are not limited to rapidly dividing cells. Dyskeratosis congenita (DC) is an inherited disorder characterized by skin pigmentation, nail dystrophy and mucosal leucoplakia. In 1995 a Dyskeratosis Congenita Registry was established at the Hammersmith Hospital. In the 46 families recruited, 76/83 patients were male, suggesting that the major form of DC is X-linked. As well as a variety of noncutaneous abnormalities, the majority (93%) of patients had bone marrow (BM) failure and this was the principal cause (71%) of early mortality. In addition to BM hypoplasia, some patients also developed myelodysplasia and acute myelod leukaemia. Pulmonary abnormalities were present in 19% of patients. In affected females the phenotype was less severe. Some female carriers of X-linked DC had clinical features. Carriers of X-linked DC showed skewed X-chromosome inactivation patterns (XCIPs), suggesting that cells expressing the normal DC allele have a growth/survival advantage over cells that express the mutant allele. Linkage analysis in multiplex families confirmed that the DKC1 gene, responsible for the X-linked form of DC, is located within Xq28 and facilitated its positional cloning. The high incidence of BM failure in association with a wide range of somatic abnormalities together with the ubiquitous expression of DKC1 suggest that, as well as having a critical role in normal haemopoiesis, this gene has a key role in normal cell biology. Dyskeratosis congenita (DC) is a rare inherited disorder characterised by the early onset of reticulate skin pigmentation, nail dystrophy, and mucosal leucoplakia. In over 80% of cases bone marrow failure develops and this is the main cause of early mortality. The DC1 gene responsible for the X linked form (MIM 305000) of dyskeratosis congenita has been mapped to Xq28. In order to narrow the candidate gene region, genetic linkage analysis was performed in eight X linked pedigrees using a set of markers spanning Xq28. A maximum lod score of 5.31 with no recombinations was achieved with marker DXS1073. Two recombination events were identified; one of these uses X chromosome inactivation pattern analysis to determine carrier status and haplotype analysis to fine map the recombination breakpoint. The fine mapping of these recombination events has enabled the candidate gene region for X linked dyskeratosis congenita to be defined as the 1.4 Mb interval between Xq3274 and DXS1108. Dyskeratosis congenita (DC) is a multisystem inherited syndrome exhibiting marked clinical and genetic heterogeneity. In its classic form, it is characterized by mucocutaneous abnormalities, BM failure, and a predisposition to cancer. BM failure is the principal cause of premature mortality. Studies over the last 15 years have led to significant advances, with 8 DC genes (DKC1, TERC, TERT, NOP10, NHP2, TIN2, C16orf57, and TCAB1) having been characterized. Seven of these are important in telomere maintenance either because they encode components of the telomerase enzyme complex (DKC1, TERC, TERT, NOP10, NHP2, and TCAB1) or the shelterin complex (TINF2). DC is therefore principally a disease of defective telomere maintenance and patients usually have very short telomeres. The genetic advances have led to the unification of DC with several other disorders, including the severe multisystem disorders Hoyeraal-Hreidarsson and Revesz syndromes, as well as a subset of patients with aplastic anemia, myelodysplasia, leukemia, and idiopathic pulmonary fibrosis. This wide spectrum of diseases ranging from classic DC to aplastic anemia can be regarded as disorders of defective telomere maintenance-"the telomereopathies." These advances have increased our understanding of normal hematopoiesis and highlighted the important role of telomerase and telomeres in human biology. They are also facilitating the diagnosis (especially when presentation is atypical) and management of DC. Dyskeratosis congenita (DC) is a multi-system disorder which in its classical form is characterised by abnormalities of the skin, nails and mucous membranes. In approximately 80% of cases, it is associated with bone marrow dysfunction. A variety of other abnormalities (including bone, brain, cancer, dental, eye, gastrointestinal, immunological and lung) have also been reported. Although first described almost a century ago it is the last 10 years, following the identification of the first DC gene (DKC1) in 1998, in which there has been rapid progress in its understanding. Six genes have been identified, defects in which cause different genetic subtypes (X-linked recessive, autosomal dominant, autosomal recessive) of DC. The products of these genes encode components that are critical for telomere maintenance; either because they are core constituents of telomerase (dyskerin, TERC, TERT, NOP10 and NHP2) or are part of the shelterin complex that protects the telomeric end (TIN2). These advances have also highlighted the connection between the more "cryptic/atypical" forms of the disease including aplastic anaemia and idiopathic pulmonary fibrosis. Equally, studies on this disease have demonstrated the critical importance of telomeres in human cells (including stem cells) and the severe consequences of their dysfunction. In this context DC and related diseases can now be regarded as disorders of "telomere and stem cell dysfunction".

Is CD99 encoded by MIC2 gene?

CD99 is a 32-kDa transmembrane glycoprotein that is encoded by the MIC2 gene

[10492040, 10941840, 15359120, 8399135, 11037347, 25007147, 22356523, 1867320, 21063743, 10782405, 24322504, 17725386, 10688843, 22020966, 9278313, 9623916, 23644663, 24158076, 15978751]

The Ewing family of tumors (EFT) is characterized by high MIC2/CD99 expression and specific EWS/ETS gene rearrangements, resulting in different chimeric transcripts. Further division into peripheral primitive neuroectodermal tumors and Ewing's sarcoma is still debated and, in the absence of distinct morphological parameters, has been based on the reactivity with neuroglial markers (NgM). We investigated 44 EFT in terms of a possible correlation between the type of EWS chimeric transcripts and reactivity with the following NgM: polyclonal and monoclonal neuron-specific enolase (NSE), S-100, chromogranin A, synaptophysin, Leu-7, glial fibrillary acid protein, and neurofilament. EWS/Fli1 fusion type 1 was detected in 30 of 44 and type 2 in 11 of 44 tumors. Three tumors, presenting with an uncommon morphology, carried rare chimeric transcripts. Our results indicate an association of lack of NgM staining with type 1 EWS/Fli1 translocations, found in 16 of 18 tumors with no NgM expression as detectable by any of the antibodies we applied. Using the monoclonal NSE antibody, 21 of 26 tumors without NgM staining expressed type 1 EWS/FLI1chimeric RNA, whereas in the groups with 1 or more and 2 or more NgM, only 9 of 17 and 1 of 5 tumors, respectively, carried type 1 EWS/Fli1 fusion transcripts. Despite this association of increased NgM expression with a non-type 1 EWS/Fli1 gene fusion, a strict correlation between the extent of NgM expression and certain EWS fusion types was not evident. This fortifies the concept to consider EFT as a spectrum of tumors and suggests the type of EWS fusion transcripts as one, but not the only parameter influencing the extent of differentiation. CD99, the product of the MIC2 gene, exhibits an erythroid-specific quantitative polymorphism co-regulated with the Xga blood group polymorphism. The co-expression of X-linked MIC2 and XG genes is presumably controlled at the transcriptional level by a single XGR locus in the pseudoautosomal region of sexual chromosomes. This locus is composed of two alleles, XGR(low) and XGR(high), which determine low or high CD99 levels (CD99-L, CD99-H) and the Xg(a-)/ Xg(a+) status. To test this hypothesis, the phenotypic relationship between Xga and CD99 antigens on human RBCs was investigated by quantitative flow cytometry using NBL-1 (anti-Xga) and 12E7 (anti-CD99) monoclonal antibodies and semi-quantitative estimate of membrane proteins and RNA by Western blot and Northern blot, respectively. The antibody binding capacity of RBCs, which is an estimation of the antigen density, was determined for 118 blood donors including 60 males and 58 females. Xg(a+) RBCs, which all belong to the group of CD99-H expressors, carry 159+/-13 and 960+/-50 copies of Xga and CD99 molecules/cell, respectively. Xg(a-) RBCs have no Xga antigen, but are subdivided into CD99-H (all male) and CD99-L expressors carrying 747+/-28 and 200+/-22 CD99 copies/cell, respectively, with identical CD99 levels between CD99-L males and females. However, among males, the CD99 expression was higher in Xg(a+) than in Xg(a-)/CD99-H individuals (P<0.01). In addition, CD99-H expressors in Xg(a+) males could be clearly subdivided into two categories, high and super high expressors, which are presumably heterozygous and homozygous for the XGR(high) allele, which fits the above hypothesis. This was not the case for Xg(a+) females where CD99-H subcategories were not found. Quantitative differences were confirmed by Western blot analysis of red cell membrane preparations from individuals of different Xga and CD99 phenotypes and by Northern blot analysis showing that the reticulocytes from CD99-L individuals expressed a reduced level of MIC2 transcripts compared to CD99-H donors. These findings further support the hypothesis of a single genetic control of CD99 and Xga expression by the XGR locus. Human CD99, which is encoded by the mic2 gene, is a ubiquitous 32 kDa transmembrane protein. Its major cellular functions are related to homotypic cell adhesion, apoptosis, vesicular protein transport, and differentiation of thymocytes or T cells. Recent reports have suggested that expression of a splice variant of CD99 increases the invasiveness of human breast cancer cells. In order to determine the structural basis of CD99 function, we have initiated structural studies on the human CD99 Type I cytoplasmic domain (hCD99cytoI) using circular dichroism and multi-dimensional NMR spectroscopy. The solution structure of hCD99cytoI shows that it has a hairpin shape anchored by two flexible loops. Consequently, hCD99cytoI does not have any regular secondary structural element; however, the NMR and CD data indicate that it possesses an intrinsic helical nature. Monoclonal antibodies (mAbs) directed against E2, a 32-kDa transmembrane protein encoded by the MIC2 gene located in the pseudoautosomal region, induce a transbilayer movement of phosphatidylserine and, to a lesser extent, phosphatidylethanolamine in human thymocytes and a Jurkat T lymphocytes. The translocation of phosphatidylserine has been evidenced by using either derivatization of anionic phospholipids with trinitrobenzenesulfonate (TNBS) or cytofluorimetry after labeling of cells with antiphosphatidylserine antibodies. The perturbation of membrane phospholipids induced by anti-E2 mAbs was further evidenced by labeling the cells with merocyanine 540. The specificity of anti-E2-induced perturbations of membrane asymmetry was tested by using a number of mAbs able to activate T cells, including CD3 and CD2. The results strongly suggest that anti-E2-induced changes in PtdSer are related to cell aggregation since the same mAbs specifically induce the aggregation of both thymocytes and Jurkat cells and since the E2 molecule has been previously implicated in the adhesive properties of human T cells with erythrocytes. Although considered a specific marker for Ewing's sarcoma/peripheral neuroectodermal tumour, the MIC2 gene product (CD99) has been immunolocalised in a variety of human tumours. The present study evaluated immunohistochemically the prevalence of CD99 expression in a series of 68 neuroendocrine tumours of different gastrointestinal and pulmonary sites. We now report on membrane and/or granular cytoplasmic immunoreactivity in 25% of these tumours, independent of their anatomical sites. In lung neuroendocrine tumours, CD99 was preferentially confined to typical carcinoids (P=0.009). A statistically significant relationship was observed between the number of CD99 positive cells but not the immunostaining patterns and the presence of local invasion and/or distant metastases (P<0.001). Moreover, there was a tendency for CD99-reactive tumours to show a reduced proliferative activity expressed by a Ki67 index of 2% (P=0.119). The number of CD99 immunoreactive cells or patterns of immunoreactivity did not correlate with the presence of associated clinical syndrome or particular hormonal immunostaining. Although the molecular basis underlying CD99 expression in neuroendocrine tumours is still poorly understood, our data suggest that CD99 may be involved in cell-to-cell adhesion of neuroendocrine tumour cells and in downregulation of their proliferative activity. The XG blood group system is best known for its contributions to the fields of genetics and chromosome mapping. This system comprises two antigens, Xg(a) and CD99, that are not antithetical but that demonstrate a unique phenotypic relationship. XG is located on the tip of the short arm of the X chromosome with exons 1 to 3 present in the pseudoautosomal region of the X (and Y) chromosome(s) and exons 4 to 10 located only on the X chromosome. Xg(a) demonstrates a clear X-linked pattern of inheritance. MIC2, the gene encoding the CD99 antigen, is found in the pseudoautosomal region of both the X and Y chromosomes. Anti-Xg(a) is comparatively rare, and only two examples of anti-CD99 have ever been identified. Alloanti-Xg(a) is considered clinically insignificant; only one example of autoanti-Xg(a) has been reported, but it resulted in severe hemolytic anemia. Insufficient data exist to determine the clinical significance of anti-CD99. Linkage of XG to several X-borne genes encoding inherited disorders has been demonstrated. CD99 is an adhesion molecule, and high levels are associated with some types of cancer. Monoclonal antibody (MAb) HBA71, which was raised against Ewing's sarcoma cells, recognizes a cell-surface glycoprotein, p30/32MIC2, that is encoded by the MIC2 gene in the pseudoautosomal region of human chromosomes X and Y. This immunohistochemical study evaluates the specificity and sensitivity of MAb HBA71 for tumor diagnosis. Frozen and paraffin-embedded tissues of more than 300 tumors of diverse histologic type, including more than 100 small round cell tumors of childhood and adolescence, were tested with this MAb by the avidin-biotin immunoperoxidase procedure. The authors found HBA71 immunoreactivity in 61 of 63 Ewing's sarcomas studied and 9 of 11 primitive neuroectodermal tumors and peripheral neuroepitheliomas. HBA71-negative tumors included neuroblastomas (0 of 24), melanomas (0 of 13), an esthesioneuroblastoma, small cell osteosarcomas (0 of 2), a malignant ectomesenchymoma, desmoplastic SRCT (0 of 5), and medulloblastomas (0 of 5). Heterogeneous expression of HBA71 immunostaining was found in some embryonal rhabdomyosarcomas (3 of 14) and astrocytomas (4 of 7), and in a few neuroendocrine tumors (4 of 26), carcinomas (3 of 94), and lymphomas (6 of 30). Because Ewing's sarcomas are consistently HBA71 positive, the authors searched for antigen-positive normal cells that may represent precursors for these tumors; however, no obvious candidate for the elusive cell of origin for Ewing's sarcoma was identified in the normal fetal tissues tested. Their findings indicate that HBA71 is a highly restricted cell-surface antigen of Ewing's sarcomas and primitive neuroectodermal tumors, and immunohistochemistry employing this antibody may be of value in the differential diagnosis of selected small round cell tumors in childhood and adolescence. Two cases of extraosseous Ewing's sarcoma/peripheral neuroectodermal tumor arising in unusual, superficial sites are reported. One tumor involved the vaginal wall of a 35-year-old woman, and the other neoplasm arose in the dermis of the vulva in a 28-year-old woman. The tumors showed characteristic microscopic features of Ewing's sarcoma/peripheral neuroectodermal tumor with nodular monotonous proliferations of undifferentiated, small, round, hyperchromatic cells with a low mitotic index. Rare rosette-like formations were apparent only in the vulvar neoplasm. The tumors displayed intense immunoreactivity in a membranous pattern for CD99, the cell surface glycoprotein encoded by the MIC2 gene. Genetically, the tumors expressed the EWS/FLI-1 chimeric transcript, derived from the t(11;22)(q24;q12) chromosomal translocation. Both patients had localized disease treated with wide local excision; one received postoperative chemotherapy, and the other received chemotherapy and radiotherapy. To date, 18 and 19 months after diagnosis, neither patient has had clinical evidence of local recurrence or metastasis. To our knowledge, these are the first reported cases of vaginal and vulvar Ewing's sarcoma/peripheral neuroectodermal tumor, confirmed with molecular genetic analysis, in the English literature. Ewing sarcoma is the third most common sarcoma in children and young adults. Its characteristic chromosomal rearrangement results in a chimerical EWSR1-ETS transcription factor. Secondary genetic alterations are very common. Membranous expression of CD99 is seen in almost all tumors. We report 2 unusual cytogenetic findings in a pediatric Ewing sarcoma, an insertion of the MIC2 gene encoding CD99 from Xp to 10p and a submicroscopic deletion of the well-known tumor supressor gene KLF6. The latter has not been described previously in pediatric neoplasms. Molecular pathways in tumorigenesis and genetic complexity in cancer are discussed. The leukocyte surface molecule CD99 is an integral membrane glycoprotein encoded by the E2/MIC2 gene. This molecule is broadly expressed on cells of the hematopoietic system and displays two surface forms, a long 32 kDa form and a short 28 kDa form. While the complete function of the CD99 molecule is unclear, it has been reported to be involved in regulation of cell adhesion, migration, and apoptosis. Thus, several CD99 monoclonal antibodies (MAbs) have been generated for biochemical and functional studies of the CD99 molecule. In the present study two CD99 MAbs, MT99/1 and MT99/2, were produced. The MAbs recognized different epitopes of the CD99 molecule. MAb MT99/1, but not MT99/2, was appropriate for biochemical characterization. Binding of MAb MT99/1 with its epitope led to the induction of cell adhesion and apoptosis. The generated MAbs can be used for future study of the function and mechanism of the CD99 molecule, including its role in the immune system, and may have application in tumor diagnosis and treatment. CD99, the product of the MIC2 gene, exhibits an erythroid-specific quantitative polymorphism coregulated with the polymorphism of the XG blood group gene. As a preliminary study of this phenomenon, human XG and CD99 recombinant proteins were expressed in murine RAG cells and analyzed by flow cytometry. Both proteins were expressed independently and at a similar level in single and double transfectants. Immunoprecipitation and Western blot analysis, using the murine monoclonal antibodies NBL-1 and 12E7, revealed species of 26 kd (XG) and 32 kd (CD99), respectively. A putative 28-kd intracellular precursor of CD99 was also detected, as was a 26-kd species after neuraminidase treatment of CD99-expressing cells. No evidence of association or complex formation between XG and CD99 proteins could be proven, either on transfected RAG cells or on human erythrocytes. These results were confirmed using somatic hybrids between single transfectants. These findings suggest that the phenotypic relationship between XG and CD99 is mostly regulated at the transcriptional level, but they do not formally exclude some posttranscriptional effect. Studies on the tissue specificity of XG expression showed that surface expression of the XG protein could not be restored in somatic hybrids between B-lymphoblastoid cell lines from Xg(a+) persons and fibroblasts (RAG) or erythroid (MEL) cells. RT-PCR analysis of the transcripts revealed the existence of an XG mRNA in each cell line, suggesting that the tissue-specific regulation of cell surface XG expression occurs either at a quantitative transcriptional level or is a posttranscriptional event. By Northern blot analysis, XG transcripts were detected in erythroid tissues and several nonerythroid tissues. (Blood. 2000;95:1819-1826) CD99 is a 32-kDa transmembrane glycoprotein that is encoded by the MIC2 gene. Our study was carried out to examine the role of CD99 in tumor progression of classical Hodgkin lymphoma (cHL). Here, we showed that lowly expressed CD99 protein in cHL cell lines and primary cHL cases correlates with the deficient expression of the positive regulatory domain 1 (PRDM1/BLIMP1). In addition, cHL cell lines showed high levels of miR-9 expression. We determined that the upregulation of CD99 induced expression of transcription factor PRDM1, a master regulator of plasma-cell differentiation, which is also a target for miR-9-mediated downregulation. Indeed, inhibition of miR-9 also triggered upregulation of PRDM1 expression. Furthermore, overexpression of CD99 resulted in changed growth features and reorganization of actin cytoskeleton. As upregulation of CD99 led to a decrease in cHL diagnosis marker CD30 and CD15 and an increase in plasma-cell differentiation marker CD38 and the restoration of B-cell makers PAX5, CD79α and CD19, we suggest that downregulated CD99 leads to the prevention of plasma-cell differentiation in Hodgkin/Reed-Sternberg (H/RS) cells. Furthermore, these data indicate that CD99 may control miR-9 expression, which directly targets PRDM1. Altogether, these results reveal a CD99-miR-9-PRDM1 molecule axis in lymphomagenesis of cHL and suggest that upregulation of CD99 in H/RS cells induces terminal B-cell differentiation, which may provide a novel therapeutic strategies for cHL. In our monoclonal antibody (MAb) stocks prepared against the BHK-21 cell antigens, two (#11875 and 28276) recognized a 21-kDa polypeptide (referred to as VAP21) which is efficiently incorporated into the rabies virion. By using these MAbs, we isolated the cDNA clones that encoded a polypeptide of 144 amino acids from our BHK-21 cell cDNA library. Based on the following evidence, the cDNA was assumed to encode a full-length sequence of VAP21 antigen: i) expression of the cDNA in animal cells resulted in the production of a polypeptide recognized by the two MAbs, and its electrophoretic mobility was the same as that of authentic VAP21 antigen; and ii) immunization with the products from the cDNA-transformed E. coli cells raised specific antibodies in rabbits that recognized a 21-kDa polypeptide in the virion. From the deduced amino acid sequence, it is suggested that the VAP21 antigen has a molecular structure of type-I transmembrane protein containing characteristic proline-rich and glycine-rich regions in its ectodomain. Homology searches resulted in finding homologous sequences (totally about 40% homology) in the human MIC2 gene product (CD99; 32-kDa) of T lymphocytes. These results suggest that the VAP21 antigen in the rabies virion is a cellular CD99-related transmembrane protein. CD99, a transmembrane protein encoded by MIC2 gene is involved in multiple cellular events including cell adhesion and migration, apoptosis, cell differentiation and regulation of protein trafficking either in physiological or pathological conditions. In osteosarcoma, CD99 is expressed at low levels and functions as a tumour suppressor. The full-length protein (CD99wt) and the short-form harbouring a deletion in the intracytoplasmic domain (CD99sh) have been associated with distinct functional outcomes with respect to tumour malignancy. In this study, we especially evaluated modulation of cell-cell contacts, reorganisation of the actin cytoskeleton and modulation of signalling pathways by comparing osteosarcoma cells characterised by different metastasis capabilities and CD99 expression, to identify molecular mechanisms responsible for metastasis. Our data indicate that forced expression of CD99wt induces recruitment of N-cadherin and β-catenin to adherens junctions. In addition, transfection of CD99wt inhibits the expression of several molecules crucial to the remodelling of the actin cytoskeleton, such as ACTR2, ARPC1A, Rho-associated, coiled-coil containing protein kinase 2 (ROCK2) as well as ezrin, an ezrin/radixin/moesin family member that has been clearly associated with tumour progression and metastatic spread in osteosarcoma. Functional studies point to ROCK2 as a crucial intracellular mediator regulating osteosarcoma migration. By maintaining c-Src in an inactive conformation, CD99wt inhibits ROCK2 signalling and this leads to ezrin decrease at cell membrane while N-cadherin and β-catenin translocate to the plasma membrane and function as main molecular bridges for actin cytoskeleton. Taken together, we propose that the re-expression of CD99wt, which is generally present in osteoblasts but lost in osteosarcoma, through inhibition of c-Src and ROCK2 activity, manages to increase contact strength and reactivate stop-migration signals that counteract the otherwise dominant promigratory action of ezrin in osteosarcoma cells. We report a rare case of Ewing's sarcoma (ES)/primitive neuroectodermal tumor (PNET) arising from the adrenal gland. A 17-year-old Japanese woman presented with left upper abdominal pain and high fever. Computed tomography and magnetic resonance imaging revealed a 15 × 10 cm tumor replacing the adrenal gland. Preoperative diagnosis was an adrenocortical carcinoma. Resection of the tumor was performed. We obtained the final diagnosis of ES/PNET by immunohistochemical molecular study with positive staining for the MIC2 gene product (CD99) and a Ewing sarcoma breakpoint region 1 (EWSR1) gene rearrangement. Local recurrence was observed one month after the surgery. The patient was then treated with systemic chemotherapy and localized radiotherapy.

Name five programs for transcript quantification from RNASeq experiments

Popular programs for transcript quantification from RNASeq experiments include: Cufflinks, RSEM, Flux Capacitor, Mitie, Miso, Tigar, Montebello, Drut, Traph, Pome, IsoformEx, Neuma,

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MOTIVATION: RNA-Seq technology is promising to uncover many novel alternative splicing events, gene fusions and other variations in RNA transcripts. For an accurate detection and quantification of transcripts, it is important to resolve the mapping ambiguity for those RNA-Seq reads that can be mapped to multiple loci: >17% of the reads from mouse RNA-Seq data and 50% of the reads from some plant RNA-Seq data have multiple mapping loci. In this study, we show how to resolve the mapping ambiguity in the presence of novel transcriptomic events such as exon skipping and novel indels towards accurate downstream analysis. We introduce ORMAN ( O ptimal R esolution of M ultimapping A mbiguity of R N A-Seq Reads), which aims to compute the minimum number of potential transcript products for each gene and to assign each multimapping read to one of these transcripts based on the estimated distribution of the region covering the read. ORMAN achieves this objective through a combinatorial optimization formulation, which is solved through well-known approximation algorithms, integer linear programs and heuristics. RESULTS: On a simulated RNA-Seq dataset including a random subset of transcripts from the UCSC database, the performance of several state-of-the-art methods for identifying and quantifying novel transcripts, such as Cufflinks, IsoLasso and CLIIQ, is significantly improved through the use of ORMAN. Furthermore, in an experiment using real RNA-Seq reads, we show that ORMAN is able to resolve multimapping to produce coverage values that are similar to the original distribution, even in genes with highly non-uniform coverage. AVAILABILITY: ORMAN is available at http://orman.sf.net The recent development of various deep sequencing techniques has led to the most powerful transcript profiling method available to date, RNA sequencing or RNA-Seq. Besides the identification of new genes and new splice variants of known genes, RNA-Seq allows to compare the whole transcriptome of any organism under two or more experimental conditions, such as before and after jasmonate treatment. However, the vast amounts of data generated during RNA-Seq experiments require complex computational methods for read mapping and expression quantification. Here, we describe a detailed protocol for the analysis of deep sequencing data, starting from the raw RNA-Seq reads. First, a quality check is performed on the raw reads to assess the quality of the sequencing. Subsequently, adapters and low-quality sequences are trimmed off the raw reads. The resulting processed reads are mapped to the reference genome, and the mapped reads are counted to generate expression data for the annotated genes for each sample. This method can be used for the analysis of RNA-Seq data of any organism for which a reference genome is available. MOTIVATION: Quantification of sequence abundance in RNA-Seq experiments is often conflated by protocol-specific sequence bias. The exact sources of the bias are unknown, but may be influenced by polymerase chain reaction amplification, or differing primer affinities and mixtures, for example. The result is decreased accuracy in many applications, such as de novo gene annotation and transcript quantification. RESULTS: We present a new method to measure and correct for these influences using a simple graphical model. Our model does not rely on existing gene annotations, and model selection is performed automatically making it applicable with few assumptions. We evaluate our method on several datasets, and by multiple criteria, demonstrating that it effectively decreases bias and increases uniformity. Additionally, we provide theoretical and empirical results showing that the method is unlikely to have any effect on unbiased data, suggesting it can be applied with little risk of spurious adjustment. AVAILABILITY: The method is implemented in the seqbias R/Bioconductor package, available freely under the LGPL license from http://bioconductor.org CONTACT: [email protected] SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online. BACKGROUND: Comprehensive annotation and quantification of transcriptomes are outstanding problems in functional genomics. While high throughput mRNA sequencing (RNA-Seq) has emerged as a powerful tool for addressing these problems, its success is dependent upon the availability and quality of reference genome sequences, thus limiting the organisms to which it can be applied. RESULTS: Here, we describe Rnnotator, an automated software pipeline that generates transcript models by de novo assembly of RNA-Seq data without the need for a reference genome. We have applied the Rnnotator assembly pipeline to two yeast transcriptomes and compared the results to the reference gene catalogs of these organisms. The contigs produced by Rnnotator are highly accurate (95%) and reconstruct full-length genes for the majority of the existing gene models (54.3%). Furthermore, our analyses revealed many novel transcribed regions that are absent from well annotated genomes, suggesting Rnnotator serves as a complementary approach to analysis based on a reference genome for comprehensive transcriptomics. CONCLUSIONS: These results demonstrate that the Rnnotator pipeline is able to reconstruct full-length transcripts in the absence of a complete reference genome. The paper addresses the problem of how to use RNA-Seq data for transcriptome reconstruction and quantification, as well as novel transcript discovery in partially annotated genomes. We present a novel annotation-guided general framework for transcriptome discovery, reconstruction and quantification in partially annotated genomes and compare it with existing annotation-guided and genome-guided transcriptome assembly methods. Our method, referred as Discovery and Reconstruction of Unannotated Transcripts (DRUT), can be used to enhance existing transcriptome assemblers, such as Cufflinks, as well as to accurately estimate the transcript frequencies. Empirical analysis on synthetic datasets confirms that Cufflinks enhanced by DRUT has superior quality of reconstruction and frequency estimation of transcripts. BACKGROUND: mRNA-Seq technology has revolutionized the field of transcriptomics for identification and quantification of gene transcripts not only at gene level but also at isoform level. Estimating the expression levels of transcript isoforms from mRNA-Seq data is a challenging problem due to the presence of constitutive exons. RESULTS: We propose a novel algorithm (IsoformEx) that employs weighted non-negative least squares estimation method to estimate the expression levels of transcript isoforms. Validations based on in silico simulation of mRNA-Seq and qRT-PCR experiments with real mRNA-Seq data showed that IsoformEx could accurately estimate transcript expression levels. In comparisons with published methods, the transcript expression levels estimated by IsoformEx showed higher correlation with known transcript expression levels from simulated mRNA-Seq data, and higher agreement with qRT-PCR measurements of specific transcripts for real mRNA-Seq data. CONCLUSIONS: IsoformEx is a fast and accurate algorithm to estimate transcript expression levels and gene expression levels, which takes into account short exons and alternative exons with a weighting scheme. The software is available at http://bioinformatics.wistar.upenn.edu/isoformex. RNA sequencing is a recent technology which has seen an explosion of methods addressing all levels of analysis, from read mapping to transcript assembly to differential expression modeling. In particular the discovery of isoforms at the transcript assembly stage is a complex problem and current approaches suffer from various limitations. For instance, many approaches use graphs to construct a minimal set of isoforms which covers the observed reads, then perform a separate algorithm to quantify the isoforms, which can result in a loss of power. Current methods also use ad-hoc solutions to deal with the vast number of possible isoforms which can be constructed from a given set of reads. Finally, while the need of taking into account features such as read pairing and sampling rate of reads has been acknowledged, most existing methods do not seamlessly integrate these features as part of the model. We present Montebello, an integrated statistical approach which performs simultaneous isoform discovery and quantification by using a Monte Carlo simulation to find the most likely isoform composition leading to a set of observed reads. We compare Montebello to Cufflinks, a popular isoform discovery approach, on a simulated data set and on 46.3 million brain reads from an Illumina tissue panel. On this data set Montebello appears to offer a modest improvement over Cufflinks when considering discovery and parsimony metrics. In addition Montebello mitigates specific difficulties inherent in the Cufflinks approach. Finally, Montebello can be fine-tuned depending on the type of solution desired. MOTIVATION: Alternative splicing (AS) is a pre-mRNA maturation process leading to the expression of multiple mRNA variants from the same primary transcript. More than 90% of human genes are expressed via AS. Therefore, quantifying the inclusion level of every exon is crucial for generating accurate transcriptomic maps and studying the regulation of AS. RESULTS: Here we introduce SpliceTrap, a method to quantify exon inclusion levels using paired-end RNA-seq data. Unlike other tools, which focus on full-length transcript isoforms, SpliceTrap approaches the expression-level estimation of each exon as an independent Bayesian inference problem. In addition, SpliceTrap can identify major classes of alternative splicing events under a single cellular condition, without requiring a background set of reads to estimate relative splicing changes. We tested SpliceTrap both by simulation and real data analysis, and compared it to state-of-the-art tools for transcript quantification. SpliceTrap demonstrated improved accuracy, robustness and reliability in quantifying exon-inclusion ratios. CONCLUSIONS: SpliceTrap is a useful tool to study alternative splicing regulation, especially for accurate quantification of local exon-inclusion ratios from RNA-seq data. AVAILABILITY AND IMPLEMENTATION: SpliceTrap can be implemented online through the CSH Galaxy server http://cancan.cshl.edu/splicetrap and is also available for download and installation at http://rulai.cshl.edu/splicetrap/. CONTACT: [email protected]. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online. MOTIVATION: RNA sequencing (RNA-Seq) is a powerful new technology for mapping and quantifying transcriptomes using ultra high-throughput next-generation sequencing technologies. Using deep sequencing, gene expression levels of all transcripts including novel ones can be quantified digitally. Although extremely promising, the massive amounts of data generated by RNA-Seq, substantial biases and uncertainty in short read alignment pose challenges for data analysis. In particular, large base-specific variation and between-base dependence make simple approaches, such as those that use averaging to normalize RNA-Seq data and quantify gene expressions, ineffective. RESULTS: In this study, we propose a Poisson mixed-effects (POME) model to characterize base-level read coverage within each transcript. The underlying expression level is included as a key parameter in this model. Since the proposed model is capable of incorporating base-specific variation as well as between-base dependence that affect read coverage profile throughout the transcript, it can lead to improved quantification of the true underlying expression level. AVAILABILITY AND IMPLEMENTATION: POME can be freely downloaded at http://www.stat.purdue.edu/~yuzhu/pome.html. CONTACT: [email protected]; [email protected] SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online. We propose a novel, efficient and intuitive approach of estimating mRNA abundances from the whole transcriptome shotgun sequencing (RNA-Seq) data. Our method, NEUMA (Normalization by Expected Uniquely Mappable Area), is based on effective length normalization using uniquely mappable areas of gene and mRNA isoform models. Using the known transcriptome sequence model such as RefSeq, NEUMA pre-computes the numbers of all possible gene-wise and isoform-wise informative reads: the former being sequences mapped to all mRNA isoforms of a single gene exclusively and the latter uniquely mapped to a single mRNA isoform. The results are used to estimate the effective length of genes and transcripts, taking experimental distributions of fragment size into consideration. Quantitative RT-PCR based on 27 randomly selected genes in two human cell lines and computer simulation experiments demonstrated superior accuracy of NEUMA over other recently developed methods. NEUMA covers a large proportion of genes and mRNA isoforms and offers a measure of consistency ('consistency coefficient') for each gene between an independently measured gene-wise level and the sum of the isoform levels. NEUMA is applicable to both paired-end and single-end RNA-Seq data. We propose that NEUMA could make a standard method in quantifying gene transcript levels from RNA-Seq data. BACKGROUND: Through transcription and alternative splicing, a gene can be transcribed into different RNA sequences (isoforms), depending on the individual, on the tissue the cell is in, or in response to some stimuli. Recent RNA-Seq technology allows for new high-throughput ways for isoform identification and quantification based on short reads, and various methods have been put forward for this non-trivial problem. RESULTS: In this paper we propose a novel radically different method based on minimum-cost network flows. This has a two-fold advantage: on the one hand, it translates the problem as an established one in the field of network flows, which can be solved in polynomial time, with different existing solvers; on the other hand, it is general enough to encompass many of the previous proposals under the least sum of squares model. Our method works as follows: in order to find the transcripts which best explain, under a given fitness model, a splicing graph resulting from an RNA-Seq experiment, we find a min-cost flow in an offset flow network, under an equivalent cost model. Under very weak assumptions on the fitness model, the optimal flow can be computed in polynomial time. Parsimoniously splitting the flow back into few path transcripts can be done with any of the heuristics and approximations available from the theory of network flows. In the present implementation, we choose the simple strategy of repeatedly removing the heaviest path. CONCLUSIONS: We proposed a new very general method based on network flows for a multiassembly problem arising from isoform identification and quantification with RNA-Seq. Experimental results on prediction accuracy show that our method is very competitive with popular tools such as Cufflinks and IsoLasso. Our tool, called Traph (Transcrips in gRAPHs), is available at: http://www.cs.helsinki.fi/gsa/traph/. BACKGROUND: RNA-Seq is revolutionizing the way transcript abundances are measured. A key challenge in transcript quantification from RNA-Seq data is the handling of reads that map to multiple genes or isoforms. This issue is particularly important for quantification with de novo transcriptome assemblies in the absence of sequenced genomes, as it is difficult to determine which transcripts are isoforms of the same gene. A second significant issue is the design of RNA-Seq experiments, in terms of the number of reads, read length, and whether reads come from one or both ends of cDNA fragments. RESULTS: We present RSEM, an user-friendly software package for quantifying gene and isoform abundances from single-end or paired-end RNA-Seq data. RSEM outputs abundance estimates, 95% credibility intervals, and visualization files and can also simulate RNA-Seq data. In contrast to other existing tools, the software does not require a reference genome. Thus, in combination with a de novo transcriptome assembler, RSEM enables accurate transcript quantification for species without sequenced genomes. On simulated and real data sets, RSEM has superior or comparable performance to quantification methods that rely on a reference genome. Taking advantage of RSEM's ability to effectively use ambiguously-mapping reads, we show that accurate gene-level abundance estimates are best obtained with large numbers of short single-end reads. On the other hand, estimates of the relative frequencies of isoforms within single genes may be improved through the use of paired-end reads, depending on the number of possible splice forms for each gene. CONCLUSIONS: RSEM is an accurate and user-friendly software tool for quantifying transcript abundances from RNA-Seq data. As it does not rely on the existence of a reference genome, it is particularly useful for quantification with de novo transcriptome assemblies. In addition, RSEM has enabled valuable guidance for cost-efficient design of quantification experiments with RNA-Seq, which is currently relatively expensive. As next generation sequencing technologies are getting more efficient and less expensive, RNA-Seq is becoming a widely used technique for transcriptome studies. Computational analysis of RNA-Seq data often starts with the mapping of millions of short reads back to the genome or transcriptome, a process in which some reads are found to map equally well to multiple genomic locations (multimapping reads). We have developed the Minimum Unique Length Tool (MULTo), a framework for efficient and comprehensive representation of mappability information, through identification of the shortest possible length required for each genomic coordinate to become unique in the genome and transcriptome. Using the minimum unique length information, we have compared different uniqueness compensation approaches for transcript expression level quantification and demonstrate that the best compensation is achieved by discarding multimapping reads and correctly adjusting gene model lengths. We have also explored uniqueness within specific regions of the mouse genome and enhancer mapping experiments. Finally, by making MULTo available to the community we hope to facilitate the use of uniqueness compensation in RNA-Seq analysis and to eliminate the need to make additional mappability files. The RNA transcriptome varies in response to cellular differentiation as well as environmental factors, and can be characterized by the diversity and abundance of transcript isoforms. Differential transcription analysis, the detection of differences between the transcriptomes of different cells, may improve understanding of cell differentiation and development and enable the identification of biomarkers that classify disease types. The availability of high-throughput short-read RNA sequencing technologies provides in-depth sampling of the transcriptome, making it possible to accurately detect the differences between transcriptomes. In this article, we present a new method for the detection and visualization of differential transcription. Our approach does not depend on transcript or gene annotations. It also circumvents the need for full transcript inference and quantification, which is a challenging problem because of short read lengths, as well as various sampling biases. Instead, our method takes a divide-and-conquer approach to localize the difference between transcriptomes in the form of alternative splicing modules (ASMs), where transcript isoforms diverge. Our approach starts with the identification of ASMs from the splice graph, constructed directly from the exons and introns predicted from RNA-seq read alignments. The abundance of alternative splicing isoforms residing in each ASM is estimated for each sample and is compared across sample groups. A non-parametric statistical test is applied to each ASM to detect significant differential transcription with a controlled false discovery rate. The sensitivity and specificity of the method have been assessed using simulated data sets and compared with other state-of-the-art approaches. Experimental validation using qRT-PCR confirmed a selected set of genes that are differentially expressed in a lung differentiation study and a breast cancer data set, demonstrating the utility of the approach applied on experimental biological data sets. The software of DiffSplice is available at http://www.netlab.uky.edu/p/bioinfo/DiffSplice. Accurately mapping RNA-Seq reads to the reference genome is a critical step for performing downstream analysis such as transcript assembly, isoform detection and quantification. Many tools have been developed; however, given the huge size of the next generation sequencing datasets and the complexity of the transcriptome, RNA-Seq read mapping remains a challenge with the ever-increasing amount of data. We develop Omicsoft sequence aligner (OSA), a fast and accurate alignment tool for RNA-Seq data. Benchmarked with existing methods, OSA improves mapping speed 4-10-fold with better sensitivity and less false positives. AVAILABILITY: OSA can be downloaded from http://omicsoft.com/osa. It is free to academic users. OSA has been tested extensively on Linux, Mac OS X and Windows platforms.

What are the main characteristics/symptoms of the "Brugada" syndrome

In 1992, Brugada and Brugada first described a new entity, which became known as Brugada syndrome, that is associated with a high risk of ventricular arrhythmias and sudden cardiac death in patients without structural heart disease. This syndrome is characterized by a distinct electrocardiographic phenotype, type 1 Brugada pattern, consisting of a coved ST-segment elevation (≥0.2 mV) followed by a negative T wave in more than one right precordial lead. The typical Brugada electrocardiogram (ECG) phenotype is often concealed in affected population. Brugada syndrome is a genetically determined familial disease with autosomal dominant transmission and variable penetrance, conferring a predisposition to sudden cardiac death due to ventricular arrhythmias. Brugada syndrome (BrS)is considered to be a primary inherited channelopathy often involving the inward sodium current and the diagnosis has traditionally required the exclusion of overt structural heart disease. Brugada syndrome (BrS) is an inherited cardiac disease characterized by ST segment elevation in V1-V3 ECG leads. Mutations SCN5A gene encoding for the cardiac voltage-gated Na(+) channel are found in some BrS patients, but also in family members with isolated conduction disturbances.

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Brugada syndrome is an inherited arrhythmia syndrome predisposing to sudden cardiac death. Six years after its initial description as a clinical entity, the first mutations in SCN5A encoding the cardiac sodium channel Nav1.5 were reported. Over 300 mutations in SCN5A have since been described in addition to mutations in genes encoding Nav1.5 auxiliary units, potassium and calcium channels. This review summarizes the current knowledge on the genetics of Brugada syndrome, focusing on SCN5A, and discusses its use as a biomarker for diagnosis, prognosis and treatment. Brugada's syndrome is one of the main causes of sudden death in young adults without a structural heart disease. This is an electrical cardiac illness secondary to a mutation of SCN5A gene of chromosome 3 that has a dominant autosomic transmission pattern. This mutation implies the dysfunction of the sodium channel that increases the Ito, loosing the dome of the epicardiac action potential phase two. An "all or none" repolarization pattern ensues and gives rise to a phase two reentry. This kind of reentry is responsible for the initiation and perpetuation of malignant ventricular arrhythmias among these patients. The clinical characteristics of the syndrome are the right bundle branch block, ST segment elevation from V1 to V3 leads and sudden death or syncope. In some patients, a pharmacological test must be done with ajmaline or procainamide to unmask the electrocardiographic changes. At present, the only effective treatment is the implantable cardioverter defibrillator (ICD). This device has the capability to reduce mortality from 40% annually to 0% at ten years. Pharmacological treatment is not useful. In 1992 we described a new syndrome consisting of syncopal episodes and/or sudden death in patients with a structurally normal heart and a characteristic electrocardiogram displaying a pattern resembling right bundle branch block with an ST segment elevation in leads V1 to V3. In 1998 it was described that the disease is genetically determined with an autosomal dominant pattern of transmission. Three different mutations have been identified. All three mutations affect the structure and the function of the sodium channel SCN5A. Two mutations result in total loss of function of the sodium channel. The other mutation results in acceleration of the recovery of the sodium channel from inactivation. The disease causes 4 to 10 sudden deaths per 10,000 inhabitants per year in areas like Thailand and Laos. Up to 50% of the yearly sudden deaths in patients with a normal heart might be caused by this syndrome. The diagnosis is easily made by means of the electrocardiogram (ECG). The presence of concealed and intermittent forms, however, makes the diagnosis difficult in some patients. The ECG can be modulated by changes in autonomic balance and the administration of antiarrhythmic drugs. Beta-adrenergic stimulation normalises the ECG, while i.v. ajmaline, flecainide or procainamide accentuate the ST segment elevation and are capable of unmasking concealed and intermittent forms of the disease. The prognosis is poor for patients who do not receive an implantable cardioverter-defibrillator. Antiarrhythmic drugs like amiodarone or beta-blockers do not prevent sudden death in symptomatic or asymptomatic individuals. Brugada syndrome is a rare cardiac arrhythmia characterized by electrocardiographic right bundle branch block and persistent ST-segment elevation in the right precordial leads. It is associated with ventricular fibrillation and a high risk for sudden cardiac death, predominantly in younger males with structurally normal hearts. Patients can remain asymptomatic, and electrocardiographic patterns can occur both spontaneously or after pharmacological induction. So far, several pathogenic genes have been identified as associated with the disease, but SCN5A is the most prevalent one. Two consensus reports to define the diagnostic criteria, risk stratification, and management of patients have been published in the last few years. This brief review focuses on the recent clinical diagnosis, genetic basis, and advances in pharmacological treatment of Brugada syndrome. Brugada syndrome is a major cause of sudden death in young adults. Fever has been described to induce a Brugada-type electrocardiogram in asymptomatic patients with a negative family history, to disclose Brugada syndrome and to increase the risk of death and induce T wave alternans in patients with diagnosed Brugada syndrome. Risk stratification is challenging and demands a careful evaluation. Here we present 2 case reports and review the literature. Brugada syndrome predisposes individuals to ventricular arrhythmias and sudden cardiac death, in the absence of structural heart disease. The typical Brugada electrocardiogram (ECG) phenotype is often concealed in affected population, and the existing genetic testing is capable of detecting just about 20% of cases. Therefore, the diagnosis largely requires various pharmacological provocative agents like class I antiarrhythmic drugs to unmask the unique features of Brugada ECG phenotype. We report an unusual case of "unmasking" of Brugada ECG pattern with ventricular tachycardia brought out by amiodarone infusion. AIMS: Brugada syndrome is characterized by typical ECG features, ventricular arrhythmias and sudden cardiac death (SCD), more frequent during nighttime. Autonomic cardiovascular control has been implicated in triggering the ventricular arrhythmias. Sleep-disordered breathing (SDB) elicits marked autonomic changes during sleep and is also associated with an increased risk of nighttime SCD. Brugada patients may have a higher likelihood of SDB compared to controls. However, no data are available on cardiac autonomic control in Brugada patients, particularly with regard to the comorbidity of SDB. METHODS: We evaluated autonomic cardiovascular control in Brugada patients with SDB (BRU-SDB, n=9), without SDB (BRU, n=9), in controls (CON, n=8) and in non-Brugada patients with SDB (n=6), during wakefulness and sleep (N2, N3 and REM). Linear spectral and entropy-derived measures of heart rate variability (HRV) were performed during apnea-free stable breathing epochs. RESULTS: Total HRV was attenuated in BRU-SDB compared to CON and BRU. During N2 and REM, in BRU-SDB patients sympathetic modulation decreased compared to BRU and CON, while during REM, they showed an increased parasympathetic modulation, compared to the other two groups. BRU-SDB and SDB were similar in terms of spectral components. Entropy-derived indices showed preserved dynamic changes in Brugada patients compared to controls through the different sleep stages. CONCLUSION: Brugada syndrome per se does not appear associated with an altered autonomic cardiovascular control during wakefulness and sleep. The comorbidity with SDB may contribute to disrupted autonomic cardiovascular regulation during sleep, possibly predisposing to the increased likelihood of sleep-related ventricular tachyarrhythmias and SCD. Our understanding of Brugada syndrome (BrS) has evolved since the syndrome was first described in 1992. BrS is considered to be a primary inherited channelopathy often involving the inward sodium current and the diagnosis has traditionally required the exclusion of overt structural heart disease. In view of recently published observations about BrS, we propose that the term BrS may actually encompass a heterogeneous group of disorders with a variety of genetic and clinical phenotypes. This disease has classically been described as a primary electrical disorder involving the sodium channel leading to the characteristic electrocardiogram (ECG) changes of BrS. We challenge the current understanding and propose that patients with structurally normal hearts, family history of sudden cardiac death, with associated genetic abnormalities only account for a subset of patients with the "Brugada pattern" ECG. There may also be some patients with a diagnosis of BrS who may also have features which overlap with arrhythmogenic right ventricular cardiomyopathy. In these patients there may be an underlying structural abnormality. In this context, it is possible that catheter ablation may abolish the "Brugada pattern" ECG changes as well as abolishing the risk of life threatening arrhythmias in these patients. Given the recent developments in the field, we propose a novel comprehensive multimodality model for risk stratification and assessment of patients with BrS. Identification of variations of diseases may facilitate more specific risk stratification models and management paradigms in patients with Brugada ECG pattern. Brugada syndrome (BrS), one of the most frequently diagnosed inherited arrhythmogenic syndromes, is responsible for more than 4% of all sudden deaths and at least 20% of sudden deaths in patients with structurally normal hearts. The sudden death is often the first symptom of BrS and appears most often already during the fourth decade of life of BrS patients. Implantation of cardioverter--defibrillator was proved to be the only effective treatment, i.e. prevention of the sudden death, in BrS. Thus, it is uniquely determined to be used in case of symptomatic BrS patients. On the contrary, the individual risk of life-threatening arrhythmias has to be thoroughly considered in case of asymptomatic BrS patients due to substantial side effects of implantation of cardioverter-defibrillator. This review first provides a summary of factors recommended for the risk stratification in BrS patients in 2005 including their support or rejection in the following studies. Subsequently, we focused on the most important risk factors newly suggested after 2005. In 1992, Brugada and Brugada first described a new entity, which became known as Brugada syndrome, that is associated with a high risk of ventricular arrhythmias and sudden cardiac death in patients without structural heart disease. This syndrome is characterized by a distinct electrocardiographic phenotype, type 1 Brugada pattern, consisting of a coved ST-segment elevation (≥0.2 mV) followed by a negative T wave in more than one right precordial lead. This pattern is dynamic, and can be spontaneous or concealed, but is unmasked under certain circumstances, like febrile states. The authors report a case in which the diagnosis of Brugada syndrome was made in the course of etiologic investigation of recurrent syncope in a febrile state. Brugada syndrome is a genetically determined familial disease with autosomal dominant transmission and variable penetrance, conferring a predisposition to sudden cardiac death due to ventricular arrhythmias. The syndrome is characterized by a typical electrocardiographic pattern in the right precordial leads. This article will focus on the new electrocardiographic features recently agreed on by expert consensus helping to identify this infequent electrocardiographic pattern. AIMS: Brugada syndrome (BrS) is an inherited cardiac disease characterized by ST segment elevation in V1-V3 ECG leads. Mutations SCN5A gene encoding for the cardiac voltage-gated Na(+) channel are found in some BrS patients, but also in family members with isolated conduction disturbances. However, some patients show coved ST elevation in the inferior or lateral leads whose association with SCN5A and familial conduction disturbances are poorly known. METHODS AND RESULTS: Two novel SCN5A mutations, D1430N and Q1476X, were identified in two unrelated families comprising patients with Brugada-like ST elevation located in the inferior leads or isolated conduction disturbances. Wild-type (WT) and D1430N mutant channels were expressed in tsA201 cells. Patch clamp electrophysiological experiments revealed total absence of Na(+) current resulting from Nav1.5 mutant when compared to WT channels. Treatments known to restore trafficking defect (incubation at low temperature, with mexiletine or lidocaine) did not restore Na(+) current supporting that Nav1.5 mutation is not a defective trafficking mutation. Furthermore, immunocytolabelling indicates the membrane localisation of both WT and mutant channels confirming what we observed in our patch clamp experiments. This suggests that the mutation may induce a complete block of Na(+) permeation. The nonsense mutation Q1476X was leading to a premature stop codon and was not expressed. CONCLUSION: Brugada-like ST elevation in the inferior ECG leads or isolated conduction disturbances were found in two unrelated families and associated with two novel SCN5A mutations. The missense and nonsense mutations are both resulting in a complete loss of ventricular Na(+) current explaining the phenotypes.

What is the main component of the Lewy bodies?

Parkinson's disease (PD) is characterized by the progressive degeneration of substantia nigra pars compacta (SNpc) dopaminergic neurones and the formation of Lewy bodies (LB) in a proportion of the remaining neurones. Alpha-synuclein has been identified as the main component of the Lewy bodies.

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Dementia with Lewy bodies (DLB) is characterized by the widespread presence of Lewy bodies (LBs) in the brain. alpha-Synuclein, the main component of LBs, is expressed as two main isoforms (112 and 140), but little is known about their differential expression in the brain. We compared alpha-synuclein 112 and alpha-synuclein 140 expression levels in the prefrontal cortices of six DLB patients, eight Alzheimer disease (AD) patients, and six control subjects. Relative alpha-synuclein 112 and alpha-synuclein 140 expression levels were determined by real-time polymerase chain reaction with competimer technology using a LightCycler System. Whereas total alpha-synuclein levels were just marginally elevated in DLB in comparison with the other groups, alpha-synuclein 112 was seen to be markedly increased in DLB compared with AD cases and controls. In contrast, alpha-synuclein 140 levels were significantly diminished in both neurodegenerative disorders in comparison with controls. These results show differential overexpression of alpha-synuclein 112 in DLB, a finding that could be of importance in DLB pathogenesis. A common finding in many neurodegenerative diseases is the presence of inclusion bodies made of aggregated proteins in neurons of affected brain regions. In Parkinson's disease, the inclusion bodies are referred to as Lewy bodies and their main component is alpha-synuclein. Although many studies have suggested that inclusion bodies may be cell protective, it is still not clear whether Lewy bodies promote or inhibit dopaminergic cell death in Parkinson's disease. Synphilin-1 interacts with alpha-synuclein and is present in Lewy bodies. Accumulation of ubiquitylated synphilin-1 leads to massive formation of inclusion bodies, which resemble Lewy bodies by their ability to recruit alpha-synuclein. We have recently isolated an isoform of synphilin-1, synphilin-1A, that spontaneously aggregates in cells, and is present in detergent-insoluble fractions of brain protein samples from alpha-synucleinopathy patients. Synphilin-1A displays marked neuronal toxicity and, upon proteasome inhibition, accumulates into ubiquitylated inclusions with concomitant reduction of its intrinsic toxicity. The fact that alpha-synuclein interacts with synphilin-1A, and is recruited to synphilin-1A inclusion bodies in neurons together with synphilin-1, further indicates that synphilin-1A cell model is relevant for research on Parkinson's disease. Synphilin-1A cell model may help provide important insights regarding the role of inclusion bodies in Parkinson's disease and other neurodegenerative disorders. Alpha-synuclein, a main component of Lewy bodies in synucleinopathies and senile plaques in Alzheimer disease, is centrally involved in neurodegeneration. Three different isoforms (alpha-synuclein 112, 126, and 140) resulting from alternative splicing have been described so far. The present study explores alpha-synuclein 126 mRNA expression levels in the prefrontal cortex of six patients with dementia with Lewy bodies, eight patients with Lewy body variant of Alzheimer disease, eight patients with Alzheimer disease, and 10 controls. Relative alpha-synuclein 126 expression levels were determined by real-time polymerase chain reaction with competimer technology. Alpha-synuclein 126 mRNA expression was markedly decreased in the three dementias in comparison with controls, suggesting an important role of this alpha-synuclein isoform in the normal brain. Fibrillar α-synuclein (α-Syn) is the principal component of Lewy bodies, which are evident in individuals affected by Parkinson disease (PD). This neuropathologic form of α-Syn plays a central role in PD progression as it has been shown to propagate between neurons. Tools that interfere with α-Syn assembly or change the physicochemical properties of the fibrils have potential therapeutic properties as they may be sufficient to interfere with and/or halt cell-to-cell transmission and the systematic spread of α-Syn assemblies within the central nervous system. Vertebrate molecular chaperones from the constitutive/heat-inducible heat shock protein 70 (Hsc/p70) family have been shown to hinder the assembly of soluble α-Syn into fibrils and to bind to the fibrils and very significantly reduce their toxicity. To understand how Hsc70 family members sequester soluble α-Syn, we set up experiments to identify the molecular chaperone-α-Syn surface interfaces. We cross-linked human Hsc70 and its yeast homologue Ssa1p and α-Syn using a chemical cross-linker and mapped the Hsc70- and Ssa1p-α-Syn interface. We show that the client binding domain of Hsc70 and Ssa1p binds two regions within α-Syn similar to a tweezer, with the first spanning residues 10-45 and the second spanning residues 97-102. Our findings define what is necessary and sufficient for engineering Hsc70- and Ssa1p-derived polypeptide with minichaperone properties with a potential as therapeutic agents in Parkinson disease through their ability to affect α-Syn assembly and/or toxicity. Parkinson's disease (PD) is characterized by the progressive degeneration of substantia nigra pars compacta (SNpc) dopaminergic neurones and the formation of Lewy bodies (LB) in a proportion of the remaining neurones. α-synuclein is the main component of LB, but the pathological mechanisms that lead to neurodegeneration associated with LB formation remain unclear. Three pivotal elements have emerged in the development of PD: α-synuclein, mitochondria and protein degradation systems. We previously reported a unique model, created by conditional genetic depletion of 26S proteasomes in the SNpc of mice, which mechanistically links these three elements with the neuropathology of PD: progressive neurodegeneration and intraneuronal inclusion formation. Using this model, we tested the hypothesis that α-synuclein was essential for the formation of inclusions and neurodegeneration caused by 26S proteasomal depletion. We found that both of these processes were independent of α-synuclein. This provides an important insight into the relationship between the proteasome, α-synuclein, inclusion formation and neurodegeneration. We also show that the autophagy-lysosomal pathway is not activated in 26S proteasome-depleted neurones. This leads us to suggest that the paranuclear accumulation of mitochondria in inclusions in our model may reflect a role for the ubiquitin proteasome system in mitochondrial homeostasis and that neurodegeneration may be mediated through mitochondrial factors linked to inclusion biogenesis. Amyloid precursor protein (APP) is involved in the accumulation of alpha-synuclein, the main component of Lewy bodies. It is currently unknown, however, whether any of the APP isoforms is instrumental in alpha-synuclein deposition in dementia with Lewy bodies (DLB). Using real-time RT-PCR, we have studied relative mRNA expression levels of APP isoforms in frozen postmortem frontal cortices of DLB patients, Alzheimer disease (AD) patients, and control subjects. Of the three main APP isoforms, the two with a Kunitz protease inhibitory (KPI) motif (APP770 and APP751) were found to be specifically overexpressed in the frontal cortices of DLB patients when compared with controls and AD patients. These findings suggest a specific role of APP isoforms containing Kunitz protease inhibitor in DLB pathogenesis. A shared neuropathological feature of idiopathic Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy is the development of intracellular aggregates of α-synuclein that gradually engage increasing parts of the nervous system. The pathogenetic mechanisms underlying these neurodegenerative disorders, however, are unknown. Several studies have highlighted similarities between classic prion diseases and these neurological proteinopathies. Specifically, identification of Lewy bodies in fetal mesencephalic neurons transplanted in patients with Parkinson's disease raised the hypothesis that α-synuclein, the main component of Lewy bodies, could be transmitted from the host brain to a graft of healthy neurons. These results and others have led to the hypothesis that a prion-like mechanism might underlie progression of synucleinopathy within the nervous system. We review experimental findings showing that misfolded α-synuclein can transfer between cells and, once transferred into a new cell, can act as a seed that recruits endogenous α-synuclein, leading to formation of larger aggregates. This model suggests that strategies aimed at prevention of cell-to-cell transfer of α-synuclein could retard progression of symptoms in Parkinson's disease and other synucleinopathies. alpha-Synuclein and ubiquitin are two Lewy body protein components that may play antagonistic roles in the pathogenesis of Lewy bodies. We examined the relationship between alpha-synuclein, ubiquitin, and lipids in Lewy bodies of fixed brain sections or isolated from cortical tissues of dementia with Lewy bodies. Lewy bodies exhibited a range of labeling patterns for alpha-synuclein and ubiquitin, from a homogeneous pattern in which alpha-synuclein and ubiquitin were evenly distributed and overlapped across the inclusion body to a concentric pattern in which alpha-synuclein and ubiquitin were partially segregated, with alpha-synuclein labeling concentrated in the peripheral domain and ubiquitin in the central domain of the Lewy body. Lipids represented a significant component in both homogeneous and concentric Lewy bodies. These results suggest that Lewy bodies are heterogeneous in their subregional composition. The segregation of alpha-synuclein to Lewy body peripheral domain is consistent with the hypothesis that alpha-synuclein is continually deposited onto Lewy bodies. We proposed the term 'Lewy body disease' (LBD) in 1980. Subsequently, we classified LBD into three types according to the distribution pattern of Lewy bodies: a brainstem type, a transitional type and a diffuse type. Later, we added the cerebral type. As we have proposed since 1980, LBD has recently been used as a generic term, including Parkinson's disease, Parkinson's disease with dementia and dementia with Lewy bodies. LBD has neuropathological characteristics whereby numerous Lewy bodies are present in the central and sympathetic nervous systems, and it is a type of alpha-synucleinopathy because the main component of Lewy body is alpha-synuclein. In this paper we explain the most recent concept of LBD from the historical viewpoint. The term alpha-synucleinopathy is used to name a group of disorders having in common the abnormal deposition of alpha-synuclein in the cytoplasm of neurons or glial cells, as well as in extracellular deposits of amyloid. In Parkinson's disease and Lewy body dementia, alpha-synuclein is the main component of Lewy bodies and dystrophic neurites; alpha-synuclein also accumulates in the cytoplasm of glial cells. In multiple system atrophy, alpha-synuclein conforms the cytoplasmic oligodendroglial inclusions and the neuronal inclusions which are the hallmark of this disease. Finally, the amyloidogenic fragment 61-95 amino acids of alpha-synuclein is the non-Abeta component of senile plaque amyloid in Alzheimer disease. Accumulations of alpha-synuclein in all these disorders have in common a fibrilar configuration, but they differ in the binding of alpha-synuclein to distinct proteins with the exception of ubiquitin whose binding to alpha-synuclein is common to all alpha-synuclein inclusions. The mechanisms leading to alpha-synuclein fragmentation and aggegation into extracellular amyloid are not known, although alpha-synuclein fragment and betaA4 aggregates are the result of abnormal cleavage of large precursors. On the other hand, several studies have shown that alpha-synuclein may adopt a fibrilar conformation and give rise to insoluble forms and high molecular weight aggregates in vitro. Similar complexes have also been observed in alpha-synucleinopathies. Although studies in vitro and in vivo have shown toxic effects of alpha-synuclein, the consequence of alpha-synuclein deposition on cell survival in alpha-synucleinopathies is not known. Parkinson's disease (PD) is one of the most common neurodegenerative diseases. Majority of PD are sporadic, for which genetic causes remain largely unknown. Alpha-synuclein, the main component of Lewy bodies, plays a central role in the PD pathogenesis. Macroautophagy is a highly conserved cellular process that digests dysfunctional macromolecules and damaged organelles. Accumulating evidence indicates that macroautophagy (hereafter referred to as autophagy) is involved in alpha-synuclein degradation. Dysregulation of autophagy has been observed in the brain tissues from PD patients and animal models. We hypothesized that change expression levels of autophagy-related genes (ATG), including ATG5, may contribute to PD. In this study, we genetically and functionally analyzed the ATG5 gene promoter in groups of sporadic PD patients and ethnic-matched healthy controls. A novel heterozygous variant, 106774459T>A, was identified in one female patient, but in none of controls, which significantly enhanced transcriptional activities of the ATG5 gene promoter. Furthermore, ATG5 gene expression level in the PD patient was significantly elevated than that in controls. Four novel heterozygous variants, 106774423C>A, 106774418C>A, 106774382C>A and 106774206G>A, were only found in controls. The variant, 106774464C>T, and SNP-106774030A>G (rs510432) were found in PD patients and controls with similar frequencies. Collectively, the variant identified in PD patient may change ATG5 protein levels and alter autophagy activities, contributing to PD onset as a risk factor. α-Synuclein is a major component of Lewy bodies in Parkinson disease (PD) and dementia with Lewy bodies (DLB). We recently showed that abnormal α-synuclein with resistance to proteinase K (PK) is deposited at presynapses of distinct brain anatomic regions from the early stages of PD and DLB. NUB1, a synphilin-1-binding protein, also accumulates in Lewy bodies, but it is not known whether abnormal α-synuclein is associated with NUB1. Here, we demonstrate that, in the brain of patients with PD and DLB, NUB1 accumulates in the presynapses in the hippocampus, cerebral neocortex, and substantia nigra in which PK-resistant α-synuclein is deposited. Endogenous NUB1 also accumulated with PK-resistant α-synuclein in the presynapses of transgenic mice that express human α-synuclein with an A53T mutation. Immunoelectron microscopy showed that NUB1 is localized to presynaptic nerve terminals where no abnormal filaments are seen. Biochemical analyses showed that NUB1 coexists with abnormal α-synuclein in the brain of DLB patients. These findings suggest that NUB1 along with abnormal α-synuclein is involved in the pathogenesis of Lewy body disease. The pre-synaptic protein alpha-synuclein is the main component of Lewy bodies and Lewy neurites, the defining neuropathological characteristics of Parkinson's disease and dementia with Lewy bodies. Mutations in the alpha-synuclein gene cause familial forms of Parkinson's disease and dementia with Lewy bodies. We previously described a transgenic mouse line expressing truncated human alpha-synuclein(1-120) that develops alpha-synuclein aggregates, striatal dopamine deficiency and reduced locomotion, similar to Parkinson's disease. We now show that in the striatum of these mice, as in Parkinson's disease, synaptic accumulation of alpha-synuclein is accompanied by an age-dependent redistribution of the synaptic SNARE proteins SNAP-25, syntaxin-1 and synaptobrevin-2, as well as by an age-dependent reduction in dopamine release. Furthermore, the release of FM1-43 dye from PC12 cells expressing either human full-length alpha-synuclein(1-140) or truncated alpha-synuclein(1-120) was reduced. These findings reveal a novel gain of toxic function of alpha-synuclein at the synapse, which may be an early event in the pathogenesis of Parkinson's disease. Parkinson disease (PD) is the most important movement disorder and about 50% of patients develop dementia over the time. PD belongs to the group of Lewy body disorders. Alpha-synuclein (AS) is the main component of Lewy bodies and its aggregation is a key event in the pathogenesis of PD. Beta-synuclein (BS) inhibits AS aggregation in vitro and in vivo and has been shown to interact directly with AS regulating its functionality and preventing its oligomerization. Recently, we have described a molecular subgroup of DLB characterized by the drastic BS reduction in cortical areas. In this study we have analyzed the expression of two BS transcripts and the main AS transcript SNCA140, in frozen samples of three brain areas, temporal cortex, caudate nucleus and pons, from patients with PD and PDD in comparison with controls. Relative mRNA expression was determined by real-time PCR with SybrGreen, neuron-specific-enolase as housekeeping gene and the deltadeltaCt method. The most important difference in BS and AS mRNA expression between PD and PDD was found in the caudate nucleus, where BS mRNA was overexpressed in PD and AS mRNA diminished in PDD. Our findings provide new insights into the pathogenesis of dementia in PD, indicating that differential BS and AS expression in the caudate nucleus may represent one of the molecular mechanisms involved in these complex diseases.

How does thyroid hormone regulate mitochondrial biogenesis in the myocardium?

T4 increases myocardial mitochondrial bioenergetic capacity, oxygen consumption and markers of mitochondrial biogenesis. The marked, parallel increases in PPARalpha levels suggest its potential involvement in mediating myocardial-specific remodeling of mitochondria in response to T4. T3 induces mitochondrial biogenesis. In fact, T3 treatment for 72h increases activity of respiratory complexes II, IV, V and citrate synthase (CS), levels of mitochondrial enzyme subunits (e.g. COXI, COXIV) and nuclear-encoded transcription factors, involved in mitochondrial biogenesis (e.g. PGC-1, mtTFA and PPAR-alpha). Furthermore, L-T3 increases the expression of factors involved in mitochondrial DNA transcription and biogenesis, such as hypoxic inducible factor-1α, mitochondrial transcription factor A and peroxisome proliferator activated receptor γ coactivator-1α, in the LV peri-infarct zone. The activation of TFAM and TFB2M expression is shown to be required for the induction of mtDNA biogenesis by T3. Truncated forms of the nuclear receptor TRα1, with molecular weights of 43 kDa (p43) and 28 Kda have been previously identified in mitochondria. P43 is a mitochondrial T3 receptor which stimulates mitochondrial transcription and protein synthesis in the presence of T3. p43 depletion in mice decreases mitochondrial DNA replication and respiratory chain activity.

[12734114, 15543939, 15893763, 20515651, 22109994, 18575627, 21914860, 19036942, 6157679, 17962579, 19462004, 2773621, 7556180, 21568860, 1321044, 20100314, 215035, 12388124]

The transcriptional coactivator the peroxisome proliferator-activated receptor gamma coactivator-1alpha (PGC-1alpha) has been identified as an important mediator of mitochondrial biogenesis based on its ability to interact with transcription factors that activate nuclear genes encoding mitochondrial proteins. The induction of PGC-1alpha protein expression under conditions that provoke mitochondrial biogenesis, such as contractile activity or thyroid hormone (T(3)) treatment, is not fully characterized. Thus we related PGC-1alpha protein expression to cytochrome c oxidase (COX) activity in 1) tissues of varying oxidative capacities, 2) tissues from animals treated with T(3), and 3) skeletal muscle subject to contractile activity both in cell culture and in vivo. Our results demonstrate a strong positive correlation (r = 0.74; P < 0.05) between changes in PGC-1alpha and COX activity, used as an index of mitochondrial adaptations. The highest constitutive levels of PGC-1alpha were found in the heart, whereas the lowest were measured in fast-twitch white muscle and liver. T(3) increased PGC-1alpha content similarly in both fast- and slow-twitch muscle, as well as in the liver, but not in heart. T(3) also induced early (6 h) increases in AMP-activated protein kinase (AMPKalpha) activity, as well as later (5 day) increases in p38 MAP kinase activity in slow-twitch, but not in fast-twitch, muscle. Contractile activity provoked early increases in PGC-1alpha, coincident with increases in mitochondrial transcription factor A (Tfam), and nuclear respiratory factor-1 (NRF-1) protein expression, suggesting that PGC-1alpha is physiologically important in coordinating the expression of the nuclear and mitochondrial genomes. Ca(2+) ionophore treatment of muscle cells led to an approximately threefold increase in PGC-1alpha protein, and contractile activity induced rapid and marked increases in both p38 MAP kinase and AMPKalpha activities. 5-Aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR) treatment of muscle cells also led to parallel increases in AMPKalpha activity and PGC-1alpha protein levels. These data are consistent with observations that indicate that increases in PGC-1alpha protein are affected by Ca(2+) signaling mechanisms, AMPKalpha activity, as well as posttranslational phosphorylation events that increase PGC-1alpha protein stability. Our data support a role for PGC-1alpha in the physiological regulation of mitochondrial content in a variety of tissues and suggest that increases in PGC-1alpha expression form part of a unifying pathway that promotes both T(3)- and contractile activity-induced mitochondrial adaptations. Changes in thyroid status are associated with profound alterations in biochemical and physiological functioning of cardiac muscle impacting metabolic rate, contractility and structural hypertrophy. Using an in vivo model of chronic treatment with thyroid hormone (T4, 0.3 mg/kg/day), we evaluated how mitochondria are regulated in response to T4, and assessed the relationship of T4-induced mitochondrial biogenesis and bioenergetics to overall cardiac hypertrophy. The role of thyroid hormone in cardiac bioenergetic remodeling was addressed in rats treated with T4 for 5, 10 and 15 days. Over that time, myocardial oxygen consumption substantially increased as did cardiac hypertrophy. Myocardial levels of mitochondrial enzyme activities, mitochondrial DNA (mtDNA), specific proteins and transcript were assessed. Activity levels of respiratory complexes I-V and citrate synthase significantly increased with 15 but not with 5 or 10-day T4 treatment. Myocardial levels of mtDNA, mitochondrial proteins (e.g. cytochrome c, cytochrome b, ATPase subunits, MnSOD) and the global transcription factor PPARalpha were significantly elevated with 15-day T4. Transcript analysis revealed increased expression of transcription factors and cofactors involved in mitochondrial biogenesis including PPARalpha, mtTFA, ErbAalpha and PGC-1alpha. Our findings indicate parallel increases in myocardial mitochondrial bioenergetic capacity, oxygen consumption and markers of mitochondrial biogenesis with 15-day T4; these changes were not present with 10-day T4 even with significant cardiac hypertrophy. The marked, parallel increases in PPARalpha levels suggest its potential involvement in mediating myocardial-specific remodeling of mitochondria in response to T4. Thyroid hormone (TH) induces marked changes in the biochemical and physiological functioning of cardiac muscle affecting its bioenergetics, contractility and structure. Using a time-course analysis of in vitro treatment of neonatal rat cardiomyocytes with triiodothyronine (T3), mitochondrial biogenesis, functional bioenergetics and cardiomyocyte hypertrophic phenotype were assessed. Activity of respiratory complexes II, IV, V and citrate synthase (CS), levels of mitochondrial enzyme subunits (e.g. COXI, COXIV) and nuclear-encoded transcription factors, involved in mitochondrial biogenesis (e.g. PGC-1, mtTFA and PPAR-alpha), were significantly elevated with 72 h T3 treatment. A time-course analysis showed an early increase (between 3 and 12 h) in activity and levels of subunits of complex IV and V, mitochondrial Ca2+ accumulation and a late increase (at 72 h) in complex II and CS activities, mitochondrial protein content and mitochondrial respiration. Based on overall protein content and specific peptide levels (e.g. actin or myosin) only mild cardiomyocyte hypertrophy was detected. T3 mediates an early stimulation of enzymes containing mtDNA encoded subunits (e.g. complex IV and V) in contrast to a different regulatory pattern for the entirely nuclear-encoded enzymes (e.g. CS and complex II). T3-regulation was similar in both neonatal and young adult cardiomyocytes (ARCM) but absent in the senescent cardiomyocytes. This model offer an opportunity to study the rapid timing of events involved in myocardial cell signaling, bioenergetics and growth dynamics in a timeframe not available with whole animal studies. Hypothyroidism during early mammalian brain development is associated with decreased expression of various mitochondrial encoded genes along with evidence for mitochondrial dysfunction. However, in-spite of the similarities between neurological disorders caused by perinatal hypothyroidism and those caused by various genetic mitochondrial defects we still do not know as to how thyroid hormone (TH) regulates mitochondrial transcription during development and whether this regulation by TH is nuclear mediated or through mitochondrial TH receptors? We here in rat cerebellum show that hypothyroidism causes reduction in expression of nuclear encoded genes controlling mitochondrial biogenesis like PGC-1alpha, NRF-1alpha and Tfam. Also, we for the first time demonstrate a mitochondrial localization of thyroid hormone receptor (mTR) isoform in developing brain capable of binding a TH response element (DR2) present in D-loop region of mitochondrial DNA. These results thus indicate an integrated nuclear-mitochondrial cross talk in regulation of mitochondrial transcription by TH during brain development. In vertebrates, skeletal muscle myofibers display different contractile and metabolic properties associated with different mitochondrial content and activity. We have previously identified a mitochondrial triiodothyronine receptor (p43) regulating mitochondrial transcription and mitochondrial biogenesis. When overexpressed in skeletal muscle, it increases mitochondrial DNA content, stimulates mitochondrial respiration, and induces a shift in the metabolic and contractile features of muscle fibers toward a slower and more oxidative phenotype. Here we show that a p43 depletion in mice decreases mitochondrial DNA replication and respiratory chain activity in skeletal muscle in association with the induction of a more glycolytic muscle phenotype and a decrease of capillary density. In addition, p43(-/-) mice displayed a significant increase in muscle mass relative to control animals and had an improved ability to use lipids. Our findings establish that the p43 mitochondrial receptor strongly affects muscle mass and the metabolic and contractile features of myofibers and provides evidence that this receptor mediates, in part, the influence of thyroid hormone in skeletal muscle. Thyroid hormone is a major determinant of energy expenditure and a key regulator of mitochondrial activity. We have previously identified a mitochondrial triiodothyronine receptor (p43) that acts as a mitochondrial transcription factor of the organelle genome, which leads, in vitro and in vivo, to a stimulation of mitochondrial biogenesis. Here we generated mice specifically lacking p43 to address its physiological influence. We found that p43 is required for normal glucose homeostasis. The p43(-/-) mice had a major defect in insulin secretion both in vivo and in isolated pancreatic islets and a loss of glucose-stimulated insulin secretion. Moreover, a high-fat/high-sucrose diet elicited more severe glucose intolerance than that recorded in normal animals. In addition, we observed in p43(-/-) mice both a decrease in pancreatic islet density and in the activity of complexes of the respiratory chain in isolated pancreatic islets. These dysfunctions were associated with a down-regulation of the expression of the glucose transporter Glut2 and of Kir6.2, a key component of the K(ATP) channel. Our findings establish that p43 is an important regulator of glucose homeostasis and pancreatic β-cell function and provide evidence for the first time of a physiological role for a mitochondrial endocrine receptor. Mitochondrial (mt)DNA mutations contribute to various disease states characterized by low ATP production. In contrast, thyroid hormone [3,3',5-triiodothyronine (T(3))] induces mitochondrial biogenesis and enhances ATP generation within cells. To evaluate the role of T(3)-mediated mitochondrial biogenesis in patients with mtDNA mutations, three fibroblast cell lines with mtDNA mutations were evaluated, including two patients with Leigh's syndrome and one with hypertrophic cardiomyopathy. Compared with control cells, patient fibroblasts displayed similar levels of mitochondrial mass, peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha), mitochondrial transcription factor A (Tfam), and uncoupling protein 2 (UCP2) protein expression. However, patient cells exhibited a 1.6-fold elevation in ROS production, a 1.7-fold elevation in cytoplasmic Ca2+ levels, a 1.2-fold elevation in mitochondrial membrane potential, and 30% less complex V activity compared with control cells. Patient cells also displayed 20-25% reductions in both cytochrome c oxidase (COX) activity and MnSOD protein levels compared with control cells. After T(3) treatment of patient cells, ROS production was decreased by 40%, cytoplasmic Ca2+ was reduced by 20%, COX activity was increased by 1.3-fold, and ATP levels were elevated by 1.6-fold, despite the absence of a change in mitochondrial mass. There were no significant alterations in the protein expression of PGC-1alpha, Tfam, or UCP2 in either T(3)-treated patient or control cells. However, T(3) restored the mitochondrial membrane potential, complex V activity, and levels of MnSOD to normal values in patient cells and elevated MnSOD levels by 21% in control cells. These results suggest that T(3) acts to reduce cellular oxidative stress, which may help attenuate ROS-mediated damage, along with improving mitochondrial function and energy status in cells with mtDNA defects. Thyroid hormone (T(3)) regulates the function of many tissues within the body. The effects of T(3) have largely been attributed to the modulation of thyroid hormone receptor-dependent gene transcription. However, nongenomic actions of T(3) via the initiation of signaling events are emerging in a number of cell types. This study investigated the ability of short-term T(3) treatment to phosphorylate and, therefore, activate signaling proteins in rat tissues in vivo. The kinases investigated included p38, AMP-activated protein kinase (AMPK), and extracellular signal-regulated kinase (ERK) 1/2. Following 2 h of T(3) treatment, p38 and AMPK phosphorylation was increased in both the slow-twitch soleus and the fast-twitch plantaris muscles. In contrast, ERK1/2 was not activated in either muscle type. Neither p38 nor AMPK was affected in heart. However, AMPK activation was decreased by T(3) in liver. ERK1/2 activation was decreased by T(3) in heart, but increased in liver. Possible downstream consequences of T(3)-induced kinase phosphorylation were investigated by measuring cAMP response element binding protein (CREB) and thyroid hormone receptor DNA binding, as well as peroxisome proliferator-activated receptor-alpha coactivator-1 mRNA levels. Protein DNA binding to the cAMP or thyroid hormone response elements was unaltered by T(3). However, peroxisome proliferator-activated receptor-alpha coactivator-1 mRNA expression was increased following 12 h of T(3) treatment in soleus. These data are the first to characterize the effects of T(3) treatment on kinase phosphorylation in vivo. We show that T(3) rapidly modifies kinase activity in a tissue-specific fashion. Moreover, the T(3)-induced phosphorylation of p38 and AMPK in both slow- and fast-twitch skeletal muscles suggests that these events may be important in mediating hormone-induced increases in mitochondrial biogenesis in skeletal muscle. In previous studies, we characterized a new hormonal pathway involving a mitochondrial T3 receptor (p43) acting as a mitochondrial transcription factor. In in vitro and in vivo studies, we have shown that p43 increases mitochondrial transcription and mitochondrial biogenesis. In addition, p43 overexpression in skeletal muscle stimulates mitochondrial respiration and induces a shift in metabolic and contractile features of muscle fibers which became more oxidative.Here we have studied the influence of p43 overexpression in skeletal muscle of mice during aging. We report that p43 overexpression initially increased mitochondrial mass. However, after the early rise in mitochondrial DNA occurring at 2 months of age in transgenic mice, we observed a progressive decrease of mitochondrial DNA content which became 2-fold lower at 23 months of age relatively to control animals. Moreover, p43 overexpression induced an oxidative stress characterized by a strong increase of lipid peroxidation and protein oxidation in quadriceps muscle, although antioxidant enzyme activities (catalase and superoxide dismutase) were stimulated. In addition, muscle atrophy became detectable at 6 months of age, probably through a stimulation of the ubiquitin proteasome pathway via two muscle-specific ubiquitin ligases E3, Atrogin-1/MAFbx and MuRF1.Taken together, these results demonstrate that a prolonged stimulation of mitochondrial activity induces muscle atrophy. In addition, these data underline the importance of a tight control of p43 expression and suggest that a deregulation of the direct T3 mitochondrial pathway could be one of the parameters involved in the occurrence of sarcopenia. T3 and GH have been implicated in the regulation of mitochondrial biogenesis. Since thyroid hormone promotes the synthesis of growth hormone, its control of human mitochondrial biogenesis could arise through a permissive action on GH biosynthesis. This was studied in hypophysectomized rats treated with T3 and/or human GH by the continuous infusion of hormone for 6 days from mini-infusion pumps implanted sc. Increases in mitochondrial respiration, enzyme activities, and protein synthesis were found in isolated liver mitochondria from rats receiving T3. In contrast, GH alone had no effect, nor did it increase the response to T3. Since it has been argued that mitochondrial biogenesis results from a direct interaction (binding) of GH with mitochondria, GH-specific binding sites were measured with 125I-bGH, a specific somatogenic receptor ligand, in isolated mitochondrial membranes in vitro. In addition, the intracellular endocytic uptake of 125I-bGH injected in vivo was compared in purified subcellular membrane fractions and mitochondria. No evidence in favour of specific GH interaction on mitochondrial membranes was found by either test. It is concluded that T3 exerts a direct, rather than permissive, effect on mitochondrial biogenesis, and that high affinity binding sites for GH are not present in rat liver mitochondria. In order to analyze the role of thyroid hormones in mitochondrial biogenesis, we have studied the expression pattern of the beta subunit of the mitochondrial ATP-synthase complex in liver and in isolated mitochondria during postnatal development of hypothyroid rats. Chemically induced hypothyroidism promoted a significant reduction in body and liver masses at all stages of development. Furthermore, plasma 3,5,3'-triiodo-L-thyronine (T3) and 3,5,3',5'-tetraiodo-L-thyronine (T4) concentrations were significantly reduced in hypothyroid animals when compared to euthyroid animals. Remarkably, steady-state beta-F1-ATPase mRNA levels in livers of hypothyroid animals showed an approximately 50% reduction when compared to age-matched euthyroid rats at all stages of development. The relative amounts of beta-F1-ATPase protein determined in isolated mitochondria of 1-day-old and adult hypothyroid animals were similar to those determined in mitochondria of age-matched euthyroids, indicating that hypothyroidism does not affect organelle differentiation in the liver of suckling and adult rats. In contrast, the relative amount of beta-F1-ATPase protein in liver homogenates varied (0-30% reduction) due to the hypothyroid condition during development. These findings suggest the existence of compensatory mechanisms operating at the translational and/or post-translational levels which promote proliferation of mitochondria in the hypothyroid liver. However, when the liver mass was considered, hypothyroidism significantly reduced overall mitochondrial proliferation in rat liver. Interestingly, the effects of thyroid hormones on the biogenesis of the ATP synthase complex at latter stages of development provide an example in which the hypothyroid condition limits the expression of the nuclear-encoded gene with no apparent effect on the expression of the mitochondrial-encoded genes (ATP synthase subunits 6-8). Exogenous thyroid hormones are regulators of cellular metabolism that involves, along with other cell structures, mitochondria. Mechanisms of the influence of thyroid hormones on the biogenesis of mtDNA are not fully understood due to their pleiotropic nature. Different ways of regulation of mitochondrial biogenesis by thyroid hormones are discussed in literature, but thyroid receptors, localized in both the nucleus and mitochondria, are the main elements of most pathways. Data on events occurring after receptor activation are rather contradictory. We investigated the degree of involvement of mitochondrial transcription factors in the biogenesis of mtDNA induced by triiodothyronine. The contribution of TFAM, TFB2M, and helicase Twinkle in thyroid-induced mtDNA biogenesis was assessed. The activation of TFAM and TFB2M expression is shown to be required for the induction of mtDNA biogenesis. The role of helicase Twinkle, the expression induction of which is also observed after triiodothyronine addition, remains unclear. The analysis of factors that activate TFAM and TFB2M expression showed that NRF-1 is the determinative regulator: deficiency of this factor leads to complete collapse of mtDNA biogenesis. However, lack of transcriptional coactivator PGC-1α did not lead to significant reduction in thyroid-induced biogenesis, whereas literature data point to its key role in the biogenesis of mitochondria. Thus, in this study the role of key transcription factors in mtDNA biogenesis induced by triiodothyronine was demonstrated for the first time in a model system. Thyroid hormone is one of the few known physiological regulators of mammalian mitochondrial biogenesis. Although it exerts a global effect on biogenesis, it does so by regulating the expression of a limited number of unidentified mitochondrial proteins. We have investigated these hormone-regulated proteins in rat liver. Hormone injection induced a 30-fold increase in the levels of cytochrome-c1 mRNA after 3 d. In addition, the mRNA for the growth-activated adenine-nucleotide translocator, ANT2, was increased 13-fold and that for the ATPase N,N'-dicyclohexylcarbodiimide-binding protein increased 4-5-fold. Mitochondrial transcripts of cytochrome-oxidase subunit I also increased. No changes were found in the mRNA levels for the F1-ATPase beta-subunit or cytochrome oxidase IV. A single low dose of triiodothyronine induces rapid increases in cytochrome-c1 and ANT2 mRNA species which parallel changes in the activity of the hormone-responsive malic enzyme, but are earlier than other mitochondrial biogenetic events. These data strengthen the view that thyroid hormone regulates synthesis of specific components within each respiratory-chain complex and that these products apparently play key roles in inner-membrane biogenesis and assembly. The significance of ANT2 induction is also discussed with respect to the rapid respiratory response induced by thyroid hormone. 3,5,3'-Levo-triiodothyronine (L-T3) is essential for DNA transcription, mitochondrial biogenesis and respiration, but its circulating levels rapidly decrease after myocardial infarction (MI). The main aim of our study was to test whether an early and sustained normalization of L-T3 serum levels after MI exerts myocardial protective effects through a mitochondrial preservation. Seventy-two hours after MI induced by anterior interventricular artery ligation, rats were infused with synthetic L-T3 (1.2 μg/kg/day) or saline over 4 weeks. Compared to saline, L-T3 infusion restored FT3 serum levels at euthyroid state (3.0 ± 0.2 versus 4.2 ± 0.3 pg/ml), improved left ventricular (LV) ejection fraction (39.5 ± 2.5 versus 65.5 ± 6.9%), preserved LV end-systolic wall thickening in the peri-infarct zone (6.34 ± 3.1 versus 33.7 ± 6.21%) and reduced LV infarct-scar size by approximately 50% (all P < 0.05). Moreover, L-T3 significantly increased angiogenesis and cell survival and enhanced the expression of nuclear-encoded transcription factors involved in these processes. Finally, L-T3 significantly increased the expression of factors involved in mitochondrial DNA transcription and biogenesis, such as hypoxic inducible factor-1α, mitochondrial transcription factor A and peroxisome proliferator activated receptor γ coactivator-1α, in the LV peri-infarct zone. To further explore mechanisms of L-T3 protective effects, we exposed isolated neonatal cardiomyocytes to H(2)O(2) and found that L-T3 rescued mitochondrial biogenesis and function and protected against cell death via a mitoKATP dependent pathway. Early and sustained physiological restoration of circulating L-T3 levels after MI halves infarct scar size and prevents the progression towards heart failure. This beneficial effect is likely due to enhanced capillary formation and mitochondrial protection. The energy relationships between cytosolic and mitochondrial metabolism were studied in the hearts from euthyroid, hypothyroid, and hyperthyroid rats. Isolated mitochondria showed high respiratory control ratios and impermeability to exogenous NADH. Hypo- and hyperthyroidism, respectively, resulted in lower and higher contents of both cytochromes per mitochondrion and mitochondrial protein per gram of wet weight of heart without changes in the ratio of cytochrome c to cytochrome aa3. In isolated perfused heart, the hyperthyroid state led to an increase in work rate and thereby an elevation of Vo2, which resulted in an increase oxidation-reduction turnover number for the cytochromes. An agreement was found between [ATP]/[ADP][Pi] of cytosolic free adenine nucleotides and the value calculated from a mathematical model of mitochondrial respiration. This implies that mitochondrial respiration is controlled at the cytochrome oxidase reaction and that oxidative phosphorylation in intact tissue is tightly coupled irrespective of thyroid state. It is concluded that thyroid hormone causes an increase in the mitochondrial mass, mitochondrial cytochrome content, and respiratory rate, and consequently expands the capacity of oxidative metabolism without an uncoupling effect on oxidative phosphorylation. Thyroid hormone [3,5,3'-triiodo-l-thyronine (T(3))] induces phenotypic alterations in cardiac mitochondria, in part by influencing protein import and the expression of the import motor mitochondrial heat shock protein (mtHsp70). Here we examined the adaptability of translocases of the inner membrane (Tim) proteins, as well as the outer membrane receptor Tom34, to T(3). Administration of T(3) to rats for 5 days increased cardiac Tim23 and Tim44 mRNA levels by 55 and 50%, respectively, but had no effect on Tim17. T(3) treatment also induced a 45% increase in Tom34 mRNA, with no accompanying changes at the protein level, suggesting regulation at the posttranscriptional level. In H9c2 cardiac cells, Tim17 mRNA was elevated by 114% by 9 days of differentiation, whereas Tim23 and Tim44 declined by 25 and 29%, respectively. To determine the functional consequences of these T(3)-induced changes, malate dehydrogenase (MDH) import rates were measured in H9c2 cells stably overexpressing Tim44 and mtHsp70, either alone or in combination. MDH import remained unaltered in cells overexpressing Tim44 or in cells overexpressing both Tim44 and mtHsp70. However, when mtHsp70 was overexpressed alone, a 13% (P < 0.05) increase in MDH import rate was observed. These findings indicate that import machinery components are differentially regulated in response to stimuli that induce mitochondrial biogenesis, like T(3) and differentiation. In addition, the induction of an import machinery component in response to T(3) may not necessarily result in functional changes in protein import during mitochondrial biogenesis. Finally, mtHsp70 may play a regulatory role in the import process that is independent of its interaction with Tim44.

What is the link between HOT regions and RNA polymerase recruitment?

Most HOT regions co-localize with RNA polymerase II binding sites, but many are not near the promoters of annotated genes. At HOT promoters, TF occupancy is strongly predictive of transcription preinitiation complex recruitment and moderately predictive of initiating Pol II recruitment, but only weakly predictive of elongating Pol II and RNA transcript abundance.

[24138567]

BACKGROUND: High-occupancy target (HOT) regions are compact genome loci occupied by many different transcription factors (TFs). HOT regions were initially defined in invertebrate model organisms, and we here show that they are a ubiquitous feature of the human gene-regulation landscape. RESULTS: We identified HOT regions by a comprehensive analysis of ChIP-seq data from 96 DNA-associated proteins in 5 human cell lines. Most HOT regions co-localize with RNA polymerase II binding sites, but many are not near the promoters of annotated genes. At HOT promoters, TF occupancy is strongly predictive of transcription preinitiation complex recruitment and moderately predictive of initiating Pol II recruitment, but only weakly predictive of elongating Pol II and RNA transcript abundance. TF occupancy varies quantitatively within human HOT regions; we used this variation to discover novel associations between TFs. The sequence motif associated with any given TF's direct DNA binding is somewhat predictive of its empirical occupancy, but a great deal of occupancy occurs at sites without the TF's motif, implying indirect recruitment by another TF whose motif is present. CONCLUSIONS: Mammalian HOT regions are regulatory hubs that integrate the signals from diverse regulatory pathways to quantitatively tune the promoter for RNA polymerase II recruitment.

List variants of the MC1R gene.

V60L D84E V92M R151C R160W R163Q D294H

[24170137, 25219681, 24917043, 26103569]

Several MC1R variants are associated with increased risk of malignant melanoma (MM) in a variety of populations. We aim to examine the influence of the MC1R variants (RHC: D84E, R151C, R160W; NRHC: V60L, R163Q and the synonymous polymorphism T314T) on the MM risk in a population from the Canary Islands. Overall, 1,046 Caucasian individuals were included in the study. A thousand of them were genotyped for MC1R variants: 509 were sporadic MM patients and 491 were healthy control subjects from general population. The analysis was adjusted for age, sex, hair colour, eye colour, skin phototype and ancestry. We found that carriers of the R151C and R163Q variants were at an increased risk for melanoma OR 2.76 (1.59-4.78) and OR 5.62 (2.54-12.42), respectively. The risk of carrying RHC variants was 3.04 (1.90-4.86). Current study confirms the increased MM risk for R151C carriers. It also supports the association between R163Q variant and MM risk in the population on the Canary Islands, as opposed to reported on northern populations. These results highlight the importance of the sample population selection in this kind of studies. The melanocortin 1 receptor (MC1R) gene encodes for a seven-pass transmembrane receptor primarily expressed on melanocytes and melanoma cells. Single nucleotide polymorphisms (SNPs, also termed variants) in MC1R frequently cause red hair, fair skin and are associated with melanoma and keratinocyte-derived skin cancer development. Activation of wild-type (WT) MC1R in skin assists cutaneous photoprotection whereas reduced MC1R signalling, seen with MC1R variants, impairs ultraviolet radiation (UVR)-protective responses. As ancestral humans migrated out of Africa, the evolutionary advantage of MC1R variants may have related to improved cutaneous vitamin D synthesis and higher birthweight reported with certain MC1R variants. Reduced photoprotection secondary to MC1R dysfunction involves pigmentary and non-pigmentary mechanisms (reduced DNA repair, effects on cell proliferation and possibly immunological parameters), leading to clonal expansion of mutated cells within skin and subsequent carcinogenesis. Recent investigations suggest an association between MC1R genotype and vitiligo, with preliminary evidence that a MC1R agonist, [Nle4-D-Phe7]-alpha-MSH, in combination with UVB, assists repigmentation. Future development of compounds to correct defective MC1R responses secondary to MC1R variants could result in photoprotective benefits for fair-skinned individuals and reduce their skin cancer risk. The MC1R gene is a key regulator of skin pigmentation. We aimed to evaluate the association between MC1R variants and the risk of sporadic cutaneous melanoma (CM) within the M-SKIP project, an international pooled-analysis on MC1R, skin cancer and phenotypic characteristics. Data included 5,160 cases and 12,119 controls from 17 studies. We calculated a summary odds ratio (SOR) for the association of each of the nine most studied MC1R variants and of variants combined with CM by using random-effects models. Stratified analysis by phenotypic characteristics were also performed. Melanoma risk increased with presence of any of the main MC1R variants: the SOR for each variant ranged from 1.47 (95%CI: 1.17-1.84) for V60L to 2.74 (1.53-4.89) for D84E. Carriers of any MC1R variant had a 66% higher risk of developing melanoma compared with wild-type subjects (SOR; 95%CI: 1.66; 1.41-1.96) and the risk attributable to MC1R variants was 28%. When taking into account phenotypic characteristics, we found that MC1R-associated melanoma risk increased only for darker-pigmented Caucasians: SOR (95%CI) was 3.14 (2.06-4.80) for subjects with no freckles, no red hair and skin Type III/IV. Our study documents the important role of all the main MC1R variants in sporadic CM and suggests that they have a direct effect on melanoma risk, independently on the phenotypic characteristics of carriers. This is of particular importance for assessing preventive strategies, which may be directed to darker-pigmented Caucasians with MC1R variants as well as to lightly pigmented, fair-skinned subjects. Author information: (1)Division of Epidemiology and Biostatistics, European Institute of Oncology, Via Ripamonti 435, Milan 20141, Italy. (2)Department of Dermatology, University of L'Aquila, 47100 L'Aquila, Italy. (3)Department of Forensic Molecular Biology, Erasmus MC University Medical Center, 3000 DR Rotterdam, The Netherlands. (4)Department of Dermatology, Erasmus MC University Medical Center, 3000 DR Rotterdam, The Netherlands. (5)1] Department of Dermatology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA [2] Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA [3] Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, USA. (6)Division of Molecular Genetic Epidemiology, German Cancer Research Center, D-69120 Heidelberg, Germany. (7)Department of Dermatology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands. (8)Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale Cancer Center, New Haven, CT 06520-8034, USA. (9)Institute of Forensic Research, 31-033 Krakow, Poland. (10)Murdoch Childrens Research Institute, Royal Children's Hospital, Victoria 3052, Australia. (11)Menzies Research Institute Tasmania, University of Tasmania, Hobart, 7001 Australia. (12)Department of Pathology, Oslo University Hospital, N-0027 Oslo, Norway. (13)International Prevention Research Institute, Lyon 69006, France. (14)Department of Biochemistry, Molecular Biology and Immunology, University of Murcia, 30100 Murcia, Spain. (15)Department of Cancer Epidemiology, Moffitt Cancer Center, Tampa, FL 33612, USA. (16)Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD 20892-7236, USA. (17)School of Epidemiology, Public Health and Preventive Medicine, University of Ottawa, Ottawa, Canada ON K1N 6N5. (18)Section of Epidemiology and Biostatistics, Institute of Cancer and Pathology, University of Leeds, Leeds LS9 7TF, UK. (19)UCL Institute of Child Health, London WC1N 1EH, UK.

Which phenotypes are associated with heterozygous mutations of the BSCL2 gene?

Heterozygous mutations in the Berardinelli-Seip congenital lipodystrophy (BSCL2) gene have been associated with different clinical phenotypes including Silver syndrome/spastic paraplegia 17, distal hereditary motor neuropathy type V, and Charcot-Marie-Tooth disease type 2 (CMT2) with predominant hand involvement.

[20806400, 15242882, 17387721, 17633104, 14981520, 20598714, 17663003]

Silver syndrome is a rare autosomal dominant neurodegenerative disorder characterized by marked amyotrophy and weakness of small hand muscles and spasticity in the lower limbs. The locus for Silver syndrome (SPG17) was assigned to a 13 cM region on chromosome 11q12-q14 in a single large pedigree. We recently found heterozygous mutations in the Berardinelli-Seip congenital lipodystrophy (BSCL2, seipin) gene causing SPG17 and distal hereditary motor neuropathy type V (distal HMN V). Here we report the clinical features of two families with heterozygous BSCL2 mutations. Interestingly, both families show a clinical phenotype different from classical Silver syndrome, and in some patients the phenotype is also different from distal HMN V. Patients in the first family had marked spasticity in the lower limbs and very striking distal amyotrophy that always started in the legs. Patients in the second family had distal amyotrophy sometimes starting and predominating in the legs, but no pyramidal tract signs. These observations broaden the clinical phenotype of disorders associated with BSCL2 mutations, having consequences for molecular genetic testing. OBJECTIVE: Heterozygous mutations in the Seipin/BSCL2 gene have recently been identified in two autosomal dominant motor neuron diseases, distal hereditary motor neuropathy type V and Silver's syndrome. Seipin protein is reportedly a transmembrane protein localized in the endoplasmic reticulum (ER). N88S and S90L mutations of this protein disrupt its glycosylation, resulting in its aggregation, but the mechanism of neurodegeneration remains unclear. To clarify the molecular pathogenesis of seipin-related motor neuron diseases, we expressed wild-type and mutant seipin proteins in neuronal and nonneuronal cells. METHODS AND RESULTS: Coexpression of human seipin and ubiquitin showed that seipin is polyubiquitinated and its ubiquitination is enhanced by mutation. Treatment of cells with a proteasome inhibitor increased the amounts of mutant seipin in the cells, suggesting that they are degraded through the ER-associated degradation pathway. Immunoprecipitation studies showed that mutant seipin stably binds to the ER chaperone calnexin, indicating accumulation of unfolded mutant seipin in the ER. Furthermore, expression of mutant seipin increased the level of ER stress-mediated molecules and induced apoptosis in cultured cells. INTERPRETATION: These findings demonstrate that seipin/BSCL2-related motor neuron diseases are novel conformational diseases, and we suspect that they are tightly associated with ER stress-mediated cell death. In 2004, heterozygous mutations (N88S, S90L) in the Seipin/BSCL2 gene were identified in two autosomal dominant motor neuron diseases, distal hereditary motor neuropathy type V (OMIM #182960) and Silver syndrome (OMIM #270685). The Seipin/BSCL2 gene was originally identified as a candidate gene for congenital generalized lipodystrophy type 2 (CGL2) (OMIM #269700). Individuals with homozygous null mutations in seipin have severe lipoatrophy, insulin resistance, hypertriglyceridemia, and mental retardation without any abnormality of the motor neurons. Recent phenotype analyses of the N88S and S90L mutations have revealed a wide spectrum of Seipin/BSCL2-related motor neuron diseases, including Silver syndrome, distal hereditary motor neuropathy type V, variants of Charcot-Marie-Tooth disease type 2, and spastic paraplegia 17; therefore, these diseases should be termed "seipinopathies". Seipin is a transmembrane protein that is localized in the endoplasmic reticulum (ER). Interestingly, the N88S and S90L mutations both disturb the N-glycosylation motif, suggesting that improper glycosylation of seipin is closely associated with the pathogenesis of motor neuron diseases. Our recent study demonstrated that seipin is proteolytically cleaved into N and C-terminal fragments and then polyubiquitinated. The N88S and S90L mutations enhance ubiquitination and degradation by UPS, and N88S and S90L mutants appear to be improperly folded, resulting in their accumulation in the ER. Furthermore, expression of mutant seipin in cultured cells activates UPR stress and induces ER stress-mediated apoptosis. Our findings suggest that seipin-related motor neuron diseases, seipinopathies are novel conformational diseases, and we propose that the pathological process of these diseases is tightly associated with ER stress-mediated cell death. Distal hereditary motor neuropathy (dHMN) or distal spinal muscular atrophy (OMIM #182960) is a heterogeneous group of disorders characterized by an almost exclusive degeneration of motor nerve fibers, predominantly in the distal part of the limbs. Silver syndrome (OMIM #270685) is a rare form of hereditary spastic paraparesis mapped to chromosome 11q12-q14 (SPG17) in which spasticity of the legs is accompanied by amyotrophy of the hands and occasionally also the lower limbs. Silver syndrome and most forms of dHMN are autosomal dominantly inherited with incomplete penetrance and a broad variability in clinical expression. A genome-wide scan in an Austrian family with dHMN-V (ref. 4) showed linkage to the locus SPG17, which was confirmed in 16 additional families with a phenotype characteristic of dHMN or Silver syndrome. After refining the critical region to 1 Mb, we sequenced the gene Berardinelli-Seip congenital lipodystrophy (BSCL2) and identified two heterozygous missense mutations resulting in the amino acid substitutions N88S and S90L. Null mutations in BSCL2, which encodes the protein seipin, were previously shown to be associated with autosomal recessive Berardinelli-Seip congenital lipodystrophy (OMIM #269700). We show that seipin is an integral membrane protein of the endoplasmic reticulum (ER). The amino acid substitutions N88S and S90L affect glycosylation of seipin and result in aggregate formation leading to neurodegeneration. BACKGROUND: Distal hereditary motor neuropathy type V (dHMN-V) and Silver syndrome are rare phenotypically overlapping diseases which can be caused by mutations in the Berardinelli-Seip Congenital Lipodystrophy 2 (BSCL2) gene or Seipin. AIM: To report the first Serbian family with a BSCL2 mutation showing variable expression within the family. PATIENTS AND METHODS: A 55-year-old woman presented with weakness of both hands at the age of 45. At age 47, she noticed distal muscle weakness and atrophy in her legs. Physical examination revealed atrophy and weakness of small hand muscles and mild atrophy and weakness of the lower limbs. There was generalized hyperreflexia with the exception of ankle reflexes which were diminished. Her 25year-old son had only stiffness of both legs at the age of 22. Physical examination revealed only generalized hyporeflexia. The third affected member in this family was her 55year-old cousin who showed a more prominent involvement of leg muscles with mild asymmetrical weakness of hand muscles and no pyramidal tract features. RESULTS: In all three patients sensory nerve conduction velocities (NCV) were normal in all extremities. Compound muscle action potential (CMAP) amplitudes were markedly reduced in all patients. Concentric needle EMG showed evidence of chronic denervation in distal muscles. DNA sequencing of BSCL2 was performed and a heterozygous N88S missense mutation in BSCL2 gene was detected in all three patients. CONCLUSION: This report is further confirmation of phenotypic heterogenity due to the N88S mutation of BSCL2 gene in the same family.

Which is the target protein of the drug nivolumab?

Nivolumab was developed as a monoclonal antibody against programmed death receptor-1, an immune checkpoint inhibitor which negatively regulates T-cell proliferation and activation.

[26406148, 25897158, 26027431, 26273207, 26448890, 26028407]

BACKGROUND: Nivolumab, a programmed death 1 (PD-1) checkpoint inhibitor, was associated with encouraging overall survival in uncontrolled studies involving previously treated patients with advanced renal-cell carcinoma. This randomized, open-label, phase 3 study compared nivolumab with everolimus in patients with renal-cell carcinoma who had received previous treatment. METHODS: A total of 821 patients with advanced clear-cell renal-cell carcinoma for which they had received previous treatment with one or two regimens of antiangiogenic therapy were randomly assigned (in a 1:1 ratio) to receive 3 mg of nivolumab per kilogram of body weight intravenously every 2 weeks or a 10-mg everolimus tablet orally once daily. The primary end point was overall survival. The secondary end points included the objective response rate and safety. RESULTS: The median overall survival was 25.0 months (95% confidence interval [CI], 21.8 to not estimable) with nivolumab and 19.6 months (95% CI, 17.6 to 23.1) with everolimus. The hazard ratio for death with nivolumab versus everolimus was 0.73 (98.5% CI, 0.57 to 0.93; P=0.002), which met the prespecified criterion for superiority (P≤0.0148). The objective response rate was greater with nivolumab than with everolimus (25% vs. 5%; odds ratio, 5.98 [95% CI, 3.68 to 9.72]; P<0.001). The median progression-free survival was 4.6 months (95% CI, 3.7 to 5.4) with nivolumab and 4.4 months (95% CI, 3.7 to 5.5) with everolimus (hazard ratio, 0.88; 95% CI, 0.75 to 1.03; P=0.11). Grade 3 or 4 treatment-related adverse events occurred in 19% of the patients receiving nivolumab and in 37% of the patients receiving everolimus; the most common event with nivolumab was fatigue (in 2% of the patients), and the most common event with everolimus was anemia (in 8%). CONCLUSIONS: Among patients with previously treated advanced renal-cell carcinoma, overall survival was longer and fewer grade 3 or 4 adverse events occurred with nivolumab than with everolimus. (Funded by Bristol-Myers Squibb; CheckMate 025 ClinicalTrials.gov number, NCT01668784.). Author information: (1)Scott N. Gettinger and Mario Sznol, Yale Cancer Center, New Haven, CT; Leora Horn, David P. Carbone, and Jeffrey A. Sosman, Vanderbilt University Medical Center; David R. Spigel, Sarah Cannon Research Institute/Tennessee Oncology, Nashville, TN; Leena Gandhi, David M. Jackman, and F. Stephen Hodi, Dana-Farber Cancer Institute; Rebecca S. Heist and Lecia V. Sequist, Massachusetts General Hospital Cancer Center; David F. McDermott, Beth Israel Deaconess Medical Center, Boston, MA; Scott J. Antonia and Mary C. Pinder-Schenck, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL; Naiyer A. Rizvi, Richard D. Carvajal, and Matthew D. Hellmann, Memorial Sloan Kettering Cancer Center, New York, NY; John D. Powderly, Carolina BioOncology Institute, Huntersville, NC; David C. Smith, University of Michigan, Ann Arbor, MI; Philip Leming, Christ Hospital Cancer Center, Cincinnati, OH; Suzanne L. Topalian, Drew M. Pardoll, and Julie R. Brahmer, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins, Baltimore, MD; and Vindira Sankar, Christoph M. Ahlers, Mark Salvati, Jon M. Wigginton, Georgia D. Kollia, and Ashok K. Gupta, Bristol-Myers Squibb, Princeton, NJ. [email protected]. (2)Scott N. Gettinger and Mario Sznol, Yale Cancer Center, New Haven, CT; Leora Horn, David P. Carbone, and Jeffrey A. Sosman, Vanderbilt University Medical Center; David R. Spigel, Sarah Cannon Research Institute/Tennessee Oncology, Nashville, TN; Leena Gandhi, David M. Jackman, and F. Stephen Hodi, Dana-Farber Cancer Institute; Rebecca S. Heist and Lecia V. Sequist, Massachusetts General Hospital Cancer Center; David F. McDermott, Beth Israel Deaconess Medical Center, Boston, MA; Scott J. Antonia and Mary C. Pinder-Schenck, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL; Naiyer A. Rizvi, Richard D. Carvajal, and Matthew D. Hellmann, Memorial Sloan Kettering Cancer Center, New York, NY; John D. Powderly, Carolina BioOncology Institute, Huntersville, NC; David C. Smith, University of Michigan, Ann Arbor, MI; Philip Leming, Christ Hospital Cancer Center, Cincinnati, OH; Suzanne L. Topalian, Drew M. Pardoll, and Julie R. Brahmer, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins, Baltimore, MD; and Vindira Sankar, Christoph M. Ahlers, Mark Salvati, Jon M. Wigginton, Georgia D. Kollia, and Ashok K. Gupta, Bristol-Myers Squibb, Princeton, NJ. BACKGROUND: Nivolumab (a programmed death 1 [PD-1] checkpoint inhibitor) and ipilimumab (a cytotoxic T-lymphocyte-associated antigen 4 [CTLA-4] checkpoint inhibitor) have been shown to have complementary activity in metastatic melanoma. In this randomized, double-blind, phase 3 study, nivolumab alone or nivolumab plus ipilimumab was compared with ipilimumab alone in patients with metastatic melanoma. METHODS: We assigned, in a 1:1:1 ratio, 945 previously untreated patients with unresectable stage III or IV melanoma to nivolumab alone, nivolumab plus ipilimumab, or ipilimumab alone. Progression-free survival and overall survival were coprimary end points. Results regarding progression-free survival are presented here. RESULTS: The median progression-free survival was 11.5 months (95% confidence interval [CI], 8.9 to 16.7) with nivolumab plus ipilimumab, as compared with 2.9 months (95% CI, 2.8 to 3.4) with ipilimumab (hazard ratio for death or disease progression, 0.42; 99.5% CI, 0.31 to 0.57; P<0.001), and 6.9 months (95% CI, 4.3 to 9.5) with nivolumab (hazard ratio for the comparison with ipilimumab, 0.57; 99.5% CI, 0.43 to 0.76; P<0.001). In patients with tumors positive for the PD-1 ligand (PD-L1), the median progression-free survival was 14.0 months in the nivolumab-plus-ipilimumab group and in the nivolumab group, but in patients with PD-L1-negative tumors, progression-free survival was longer with the combination therapy than with nivolumab alone (11.2 months [95% CI, 8.0 to not reached] vs. 5.3 months [95% CI, 2.8 to 7.1]). Treatment-related adverse events of grade 3 or 4 occurred in 16.3% of the patients in the nivolumab group, 55.0% of those in the nivolumab-plus-ipilimumab group, and 27.3% of those in the ipilimumab group. CONCLUSIONS: Among previously untreated patients with metastatic melanoma, nivolumab alone or combined with ipilimumab resulted in significantly longer progression-free survival than ipilimumab alone. In patients with PD-L1-negative tumors, the combination of PD-1 and CTLA-4 blockade was more effective than either agent alone. (Funded by Bristol-Myers Squibb; CheckMate 067 ClinicalTrials.gov number, NCT01844505.). Nivolumab was developed as a monoclonal antibody against programmed death receptor-1, an immune checkpoint inhibitor which negatively regulates T-cell proliferation and activation. Intravenous administration of nivolumab was approved for the treatment of unresectable malignant melanoma in 2014 in Japan. When advanced melanoma patients were treated with nivolumab, median overall survival became longer. Overall survival rate was significantly better in nivolumab-treated melanoma patients than dacarbazine-treated melanoma patients. Nivolumab had an acceptable long-term tolerability profile, with 22% of patients experiencing grade 3 or 4 adverse events related to the drug. Therefore, nivolumab can become an alternative therapy for advanced malignant melanoma. BACKGROUND: Patients with advanced squamous-cell non-small-cell lung cancer (NSCLC) who have disease progression during or after first-line chemotherapy have limited treatment options. This randomized, open-label, international, phase 3 study evaluated the efficacy and safety of nivolumab, a fully human IgG4 programmed death 1 (PD-1) immune-checkpoint-inhibitor antibody, as compared with docetaxel in this patient population. METHODS: We randomly assigned 272 patients to receive nivolumab, at a dose of 3 mg per kilogram of body weight every 2 weeks, or docetaxel, at a dose of 75 mg per square meter of body-surface area every 3 weeks. The primary end point was overall survival. RESULTS: The median overall survival was 9.2 months (95% confidence interval [CI], 7.3 to 13.3) with nivolumab versus 6.0 months (95% CI, 5.1 to 7.3) with docetaxel. The risk of death was 41% lower with nivolumab than with docetaxel (hazard ratio, 0.59; 95% CI, 0.44 to 0.79; P<0.001). At 1 year, the overall survival rate was 42% (95% CI, 34 to 50) with nivolumab versus 24% (95% CI, 17 to 31) with docetaxel. The response rate was 20% with nivolumab versus 9% with docetaxel (P=0.008). The median progression-free survival was 3.5 months with nivolumab versus 2.8 months with docetaxel (hazard ratio for death or disease progression, 0.62; 95% CI, 0.47 to 0.81; P<0.001). The expression of the PD-1 ligand (PD-L1) was neither prognostic nor predictive of benefit. Treatment-related adverse events of grade 3 or 4 were reported in 7% of the patients in the nivolumab group as compared with 55% of those in the docetaxel group. CONCLUSIONS: Among patients with advanced, previously treated squamous-cell NSCLC, overall survival, response rate, and progression-free survival were significantly better with nivolumab than with docetaxel, regardless of PD-L1 expression level. (Funded by Bristol-Myers Squibb; CheckMate 017 ClinicalTrials.gov number, NCT01642004.).

The CXCR2 receptor is targeted in cancer. Name five antagonists.

There are numerous CXCR2 receptor antagonists, such as SB225002, G31P, SCH-527123, AZ10397767, SCH-479833.

[23019013, 17634442, 18289803, 23204236, 19809428, 18780829, 23359652, 21035946, 15623601, 20967859, 12244149, 21670971, 12753603, 19549892, 19293256, 21328342, 15805273, 18790747, 22590561, 11700073, 20652010, 16540656, 22391039]

Prostate cancer is the most common malignancy in Western countries. Chemokine C-X-C motif receptor 1 (CXCR1) and CXCR2 play a key role in generation and regulation of CXC chemokine signaling. CXCR1 is a receptor for interleukin 8 (IL8), a pro-inflammatory chemokine, and CXCR1/2 are crucially involved in the prostate cancer development and progression. Thus, we generated a high-affinity human CXCR1/CXCR2 inhibitor, CXCL8 (3-72) K11R/G31P, named G31P, which is a synthetic derivative of the human cytokine, IL-8. In this study, we investigated the effects of G31P on regulation of prostate cancer cell growth in vitro and in nude mouse xenografts. Cell viability, adhesion, and wound healing assays were used to assess the effects of G31P on growth, adhesion, and migration of PC-3 human prostate cancer cells in vitro, respectively. Nude mouse xenografts and xenograft implantation assays were performed to determine the effect of G31P on PC-3 cells in vivo. Immunohistochemistry was used to detect gene expression, and fluorescence imaging was used to detect tumor volume and microvessel density in tumor xenografts. The data showed that G31P treatment significantly reduced PC-3 cell viability, adhesion and migration capacity in a dose-dependent manner (up to 100 ng/ml). Additionally, G31P treatment of nude mice suppressed the growth of orthotopically transplanted tumor xenografts. G31P also inhibited tumor tissue vascularization, which was associated with the decreased expression of vascular endothelial growth factor and nuclear transcription factor (NF)-κB in orthotopic xenograft tissues. This study provides evidence that G31P, a CXCR1/2 inhibitor, may effectively control prostate cancer. Although originally identified as mediators of inflammation, it is now apparent that chemokines play a fundamental role in tissue development. In this study, ELR(+)-CXC chemokine family members CXCL2 and CXCL7, along with their preferred receptor CXCR2, were expressed at the earliest stages of metanephric development in the rat, and signaling through this receptor was required for the survival and maintenance of the undifferentiated metanephric mesenchyme (MM). A specific antagonist of the CXCR2 receptor SB225002 induced apoptosis in this population but did not affect more mature structures or cells in the ureteric bud. CXCL7 treatment of isolated MM elicited an angiogenic response by upregulation of matrix metalloprotease 9 and endothelial and mesangial markers (platelet-endothelial cell adhesion molecule, Megsin, Thy-1, PDGF receptor alpha, and vascular alpha-actin) and induced SB225002-sensitive cell invasion through a matrix. Because Wilms' tumor cells may similarly depend on CXCR2 signaling for survival, primary tumor samples were analyzed, and 15 of 16 Wilms' tumors were found to be CXCR2 positive, whereas grossly normal kidney tissues from tumor patients or renal cell carcinomas were CXCR2 negative. Furthermore, cell lines derived from Wilms' tumors but not those from renal cell carcinomas were sensitive to SB225002-induced apoptosis. These data provide evidence for a prosurvival and proangiogenic role of ELR(+)-CXC chemokines and their receptor CXCR2 during metanephric development and suggest a novel mechanism for chemotherapeutic intervention in Wilms' tumor. Benzo(a)pyrene (BP) is an environmental contaminant known to favor airway inflammation likely through up-regulation of pro-inflammatory cytokines. The present study was designed to characterize its effects toward interleukin-8 (IL-8), a well-established pulmonary inflammatory cytokine. In primary human macrophages, BP was shown to induce IL-8 expression at both mRNA and secretion levels in a dose-dependent manner. Such an up-regulation was likely linked to aryl hydrocarbon receptor (AhR)-activation since BP-mediated IL-8 induction was reduced after AhR expression knock-down through RNA interference. Moreover, electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation experiments showed BP-triggered binding of AhR to a consensus xenobiotic responsive element (XRE) found in the human IL-8 promoter. Finally, BP administration to mice led to over-expression of keratinocyte chemoattractant (KC), the murine functional homologue of IL-8, in lung. It also triggered the recruitment of neutrophils in bronchoalveolar lavage (BAL) fluids, which was however fully abolished in the presence of a chemical antagonist of the KC/IL-8 receptors CXCR1/CXCR2, thus supporting the functional and crucial involvement of KC in BP-induced lung inflammation. Overall, these data highlight an AhR-dependent regulation of IL-8 in response to BP that likely contributes to the airway inflammatory effects of this environmental chemical. CXCR2 in non-small cell lung cancer (NSCLC) has been studied mainly in stromal cells and is known to increase tumor inflammation and angiogenesis. Here, we examined the prognostic importance of CXCR2 in NSCLC and the role of CXCR2 and its ligands in lung cancer cells. The effect of CXCR2 expression on tumor cells was studied using stable knockdown clones derived from a murine KRAS/p53-mutant lung adenocarcinoma cell line with high metastatic potential and an orthotopic syngeneic mouse model and in vitro using a CXCR2 small-molecule antagonist (SB225002). CXCR2 protein expression was analyzed in tumor cells from 262 NSCLC. Gene expression profiles for CXCR2 and its ligands (CXCR2 axis) were analyzed in 52 human NSCLC cell lines and 442 human lung adenocarcinomas. Methylation of CXCR2 axis promoters was determined in 70 human NSCLC cell lines. Invasion and metastasis were decreased in CXCR2 knockdown clones in vitro and in vivo. SB225002 decreased invasion in vitro. In lung adenocarcinomas, CXCR2 expression in tumor cells was associated with smoking and poor prognosis. CXCR2 axis gene expression profiles in human NSCLC cell lines and lung adenocarcinomas defined a cluster driven by CXCL5 and associated with smoking, poor prognosis, and RAS pathway activation. Expression of CXCL5 was regulated by promoter methylation. The CXCR2 axis may be an important target in smoking-related lung adenocarcinoma. BACKGROUND: We determined how CXC-chemokine signalling and necrosis factor-kappaB (NF-kappaB) activity affected heat-shock protein 90 (Hsp90) inhibitor (geldanamycin (GA) and 17-allylamino-demethoxygeldanamycin (17-AAG)) cytotoxicity in castrate-resistant prostate cancer (CRPC). METHODS: Geldanamycin and 17-AAG toxicity, together with the CXCR2 antagonist AZ10397767 or NF-kappaB inhibitor BAY11-7082, was assessed by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay in two CRPC lines, DU145 and PC3. Flow cytometry quantified apoptotic or necrosis profiles. Necrosis factor-kappaB activity was determined by luciferase readouts or indirectly by quantitative PCR and ELISA-based determination of CXCL8 expression. RESULTS: Geldanamycin and 17-AAG reduced PC3 and DU145 cell viability, although PC3 cells were less sensitive. Addition of AZ10397767 increased GA (e.g., PC3 IC(20): from 1.67+/-0.4 to 0.18+/-0.2 nM) and 17-AAG (PC3 IC(20): 43.7+/-7.8 to 0.64+/-1.8 nM) potency in PC3 but not DU145 cells. Similarly, BAY11-7082 increased the potency of 17-AAG in PC3 but not in DU145 cells, correlating with the elevated constitutive NF-kappaB activity in PC3 cells. AZ10397767 increased 17-AAG-induced apoptosis and necrosis and decreased NF-kappaB activity/CXCL8 expression in 17-AAG-treated PC3 cells. CONCLUSION: Ansamycin cytotoxicity is enhanced by inhibiting NF-kappaB activity and/or CXC-chemokine signalling in CRPC cells. Detecting and/or inhibiting NF-kappaB activity may aid the selection and treatment response of CRPC patients to Hsp90 inhibitors. Constitutive activation of nuclear factor (NF)-kappaB is linked with the intrinsic resistance of androgen-independent prostate cancer (AIPC) to cytotoxic chemotherapy. Interleukin-8 (CXCL8) is a transcriptional target of NF-kappaB whose expression is elevated in AIPC. This study sought to determine the significance of CXCL8 signaling in regulating the response of AIPC cells to oxaliplatin, a drug whose activity is reportedly sensitive to NF-kappaB activity. Administration of oxaliplatin to PC3 and DU145 cells increased NF-kappaB activity, promoting antiapoptotic gene transcription. In addition, oxaliplatin increased the transcription and secretion of CXCL8 and the related CXC-chemokine CXCL1 and increased the transcription and expression of CXC-chemokine receptors, especially CXC-chemokine receptor (CXCR) 2, which transduces the biological effects of CXCL8 and CXCL1. Stimulation of AIPC cells with CXCL8 potentiated NF-kappaB activation in AIPC cells, increasing the transcription and expression of NF-kappaB-regulated antiapoptotic genes of the Bcl-2 and IAP families. Coadministration of a CXCR2-selective antagonist, AZ10397767 (Bioorg Med Chem Lett 18:798-803, 2008), attenuated oxaliplatin-induced NF-kappaB activation, increased oxaliplatin cytotoxicity, and potentiated oxaliplatin-induced apoptosis in AIPC cells. Pharmacological inhibition of NF-kappaBorRNA interference-mediated suppression of Bcl-2 and survivin was also shown to sensitize AIPC cells to oxaliplatin. Our results further support NF-kappaB activity as an important determinant of cancer cell sensitivity to oxaliplatin and identify the induction of autocrine CXCR2 signaling as a novel mode of resistance to this drug. Recent evidence indicates that CXCR2 signaling is crucial for cancer progression, and its antagonist SB225002 induces apoptosis in Wilms' tumor cells. Here, we investigated the effect of SB225002 on cell cycle progression and apoptosis induction in vitro, using CDDP-sensitive and -resistant OVCA cell lines with different p53 status (wild type, mutant or null). Adenovirus infection of wild-type p53 or transfection of p53 siRNA was used to over-express or knock-down p53. Cell cycle and apoptosis were determined by flow cytometry or Hoechst staining and observation of nuclear morphology. Our data demonstrated that SB225002 induced apoptosis in both wild-type and p53-deficient ovarian cancer (OVCA) cells through alternative mechanisms. SB225002 promoted mitotic catastrophe, as evidenced by the accumulation of mitotic cells with spindle abnormalities, chromosome mis-segregation, multi-polar cell division, multiple nuclei, aneuploidy/polyploidy and subsequent extensive apoptosis. SB225002-induced mitotic catastrophe appeared to be mediated by down-regulation of checkpoint kinase Chk1 and Cdk1-cyclin B activation. In cells expressing wild-type p53 (OV2008 and C13*), SB225002 increased total and phospho-Ser p53 levels, and p53 knock-down decreased SB225002-induced apoptosis, without affecting premature mitosis. These results suggest that SB225002 induces p53-dependent apoptosis, and provokes mitotic catastrophe in p53-independent manner in p53 wild-type cells. Reconstitution with wild-type P53 in P53-null SKOV3 cell attenuated SB225002-induced mitotic catastrophe, suggesting p53 prevented mitotic catastrophe induced by SB225002 in p53-deficient OVCA cells. Finally, the effect of SB225002 could not be prevented by pretreatment with CXCR2 ligand or its neutralizing antibody. The present studies demonstrate for the first time that SB225002 has dual actions in OVCA cells, inducing classic apoptosis through p53 activation and provoking mitotic catastrophe in both p53 wild-type and deficient cells by Chk1 inhibition and Cdk activation. These findings raise the possibility of SB225002 as a new candidate molecule for OVCA therapy independent of the p53 status. CXCR1 and CXCR2 are G-protein coupled receptors, that have been shown to play important role in tumor growth and metastasis, and are prime targets for the development of novel therapeutics. Here, we report that targeting CXCR2 and CXCR1 activity using orally active small molecule antagonist (SCH-527123, SCH-479833) inhibits human colon cancer liver metastasis mediated by decreased neovascularization and enhanced malignant cell apoptosis. There were no differences in primary tumor growth. These studies demonstrate the important role of CXCR2/1 in colon cancer metastasis and that inhibition of CXCR2 and CXCR1, small molecule antagonists provides a novel therapeutic strategy. PURPOSE: This study aims to investigate the role of gastrin-17 (G17) on angiogenesis features in gliomas both in vitro and in vivo. EXPERIMENTAL DESIGN: The influences of G17 and G17 receptor antagonists were characterized in vitro in terms of angiogenesis on human umbilical vein endothelial cell (HUVEC) tubulogenesis processes on Matrigel and in vivo with respect to U373 orthotopic glioma xenografts. The influence of phosphatidylinositol 3'-kinase, protein kinase C, and nuclear factor-kappaB inhibitors was characterized in vitro on G17-mediated HUVEC tubulogenesis. G17-mediated release of interleukin (IL)-8 from HUVECs and G17-induced modifications in nuclear factor-kappaB DNA binding activity were characterized by means of specific enzyme-linked immunosorbent assays. The influence of G17 on E- and P-selectin expression was determined by means of computer-assisted microscopy, whereas the influence of E- and P-selectin on HUVEC migration was approached by means of antisense oligonucleotides. The chemotactic influence of G17 and IL-8 on HUVEC migration was characterized by means of computer-assisted videomicroscopy with Dunn chambers. RESULTS: Messenger RNAs for cholecystokinin (CCK)A, CCKB, and CCKC receptors were present in HUVECs and microvessels dissected from a human glioblastoma. Whereas G17 significantly increased the levels of angiogenesis in vivo in the U373 experimental glioma model and in vitro in the HUVECs, the CCKB receptor antagonist L365,260 significantly counteracted the G17-mediated proangiogenic effects. G17 chemoattracted HUVECs, whereas IL-8 failed to do so. IL-8 receptor alpha (CXCR1) and IL-8 receptor beta (CXCR2) mRNAs were not detected in these endothelial cells. Gastrin significantly (but only transiently) decreased the level of expression of E-selectin, but not P-selectin, whereas IL-8 increased the expression of E-selectin. Specific antisense oligonucleotides against E- and P-selectin significantly decreased HUVEC tubulogenesis processes in vitro on Matrigel. CONCLUSIONS: The present study shows that gastrin has marked proangiogenic effects in vivo on experimental gliomas and in vitro on HUVECs. This effect depends in part on the level of E-selectin activation, but not on IL-8 expression/release by HUVECs. The brain is a target organ for recreational drugs and HIV-1. Epidemiological data demonstrate that opioid abuse is a risk factor for HIV-1 infection and progression to AIDS. Chemokines and their receptors have been implicated in the neuropathogenesis of HIV-1 infections. However, little is known about the effects of opioids on the expression of chemokines and their receptors (the latter also are HIV-1 coreceptors) by cells of the CNS. Herein we describe the effects of morphine on gene expression of the alpha- and beta-chemokines and their receptors by the astrocytoma cell line U87 and by primary normal human astrocyte (NHA) cultures. U87 cells treated with morphine showed significant down-regulation of IL-8 gene expression, whereas expression of the IL-8 receptor CXCR2 was reciprocally up-regulated as detected by RT-PCR. Treatment of NHAs with morphine suppressed IL-8 and macrophage-inflammatory protein-1beta gene expression, whereas expression of their receptor genes, CCR3 and CCR5, was simultaneously enhanced. These morphine-induced effects on U87 and NHA cells were reversed by the opioid mu receptor antagonist beta-funaltrexamine. Morphine also enhanced the constitutive expression of the opioid mu receptor on astroglial cells. Our results support the hypothesis that opioids play a significant role in the susceptibility of the CNS to HIV-1 infection and subsequent encephalopathy by inhibiting local production of HIV-1-protective chemokines (IL-8 and macrophage-inflammatory protein-1beta) and enhancing expression of HIV-1 entry coreceptor genes (CCR3, CCR5, and CXCR2) within the CNS. These effects of opioids appear to be mediated through the opioid mu receptor that we demonstrated on astroglial cells. This study evaluated the relevance of CXCR2 chemokine receptors in oral squamous cell carcinoma, by means of in vitro and in vivo approaches. The in vitro incubation of the selective and non-peptide CXCR2 receptor antagonist N-(2-hydroxy-4-nitrophenyl)-N9-(2-bromophenyl) Urea (SB225002; 25 to 800 nM) produced a time- and concentration-dependent inhibition of SCC158 (rat) and HN30 (human) cell lines viability. Conversely, this antagonist did not significantly affect the viability of the immortalized keratinocyte lineage, HaCaT. Additionally, the incubation of human IL-8 and rat CINC-1 CXCR2 agonists produced a concentration-related increase on HN30 and SCC158 proliferation. The submucosal injection of SCC158 cells (5 × 10(6) cells) into the tongue of Fischer 344 rats induced tumor development, which displayed typical clinical features. Immunohistochemical analysis of rat tongue biopsies revealed a marked increase of CXCR2 receptor immunoreactivity, which was accompanied by augumented expression of VEGF and caspase-3. Our data suggests an important role for CXCR2 receptors in oral squamous cell carcinoma. To examine the significance of chemokine activation of CXCR2 in wound healing after chemical burn, cutaneous injury was created by topical application of nitrogen mustard on CXCR2 wild type (+/+), heterozygous (+/-), and knockout (-/-) mice. Wounds were analyzed histologically for neutrophil and monocyte infiltration and for reepithelialization at postwound days 4, 7, and 10. Neutrophil recruitment to the wound site was reduced through postwound day 7 in CXCR2 -/- mice as indicated by myeloperoxidase assay and by visual quantitation. Because there is always concern that mice with targeted deletion of a specific receptor may undergo developmental adaptations to offset the loss of the receptor, we also accessed chemical wound repair in the presence of a small molecule antagonist of CXCR2. Dietary supplementation with a CXCR2 antagonist (SB-265610) during the wound repair process also markedly delayed healing parameters in CXCR2 +/+ mice, even greater than treatment with glucocorticoids. These parallel studies further establish that mice deficient in CXCR2 function exhibit delayed cutaneous wound healing that may be primarily linked to impaired neutrophil recruitment after chemical burn with nitrogen mustard. Thus, there may be a potential therapeutic benefit of treating nitrogen mustard-induced skin lesions with agonists of CXCR2 to facilitate the wound repair process. The prostaglandin F(2alpha) (PGF(2alpha)) receptor (FP) is elevated in endometrial adenocarcinoma. This study found that PGF(2alpha) signaling via FP regulates expression of chemokine (C-X-C motif) ligand 1 (CXCL1) in endometrial adenocarcinoma cells. Expression of CXCL1 and its receptor, CXCR2, are elevated in cancer tissue compared with normal endometrium and localized to glandular epithelium, endothelium, and stroma. Treatment of Ishikawa cells stably transfected with the FP receptor (FPS cells) with 100 nmol/L PGF(2alpha) increased CXCL1 promoter activity, mRNA, and protein expression, and these effects were abolished by cotreatment of cells with FP antagonist or chemical inhibitors of Gq, epidermal growth factor receptor, and extracellular signal-regulated kinase. Similarly, CXCL1 was elevated in response to 100 nmol/L PGF(2alpha) in endometrial adenocarcinoma explant tissue. CXCL1 is a potent neutrophil chemoattractant. The expression of CXCR2 colocalized to neutrophils in endometrial adenocarcinoma and increased neutrophils were present in endometrial adenocarcinoma compared with normal endometrium. Conditioned media from PGF(2alpha)-treated FPS cells stimulated neutrophil chemotaxis, which could be abolished by CXCL1 protein immunoneutralization of the conditioned media or antagonism of CXCR2. Finally, xenograft tumors in nude mice arising from inoculation with FPS cells showed increased neutrophil infiltration compared with tumors arising from wild-type cells or following treatment of mice bearing FPS tumors with CXCL1-neutralizing antibody. In conclusion, our results show a novel PGF(2alpha)-FP pathway that may regulate the inflammatory microenvironment in endometrial adenocarcinoma via neutrophil chemotaxis. PURPOSE: Melanoma, the most aggressive form of skin cancer, accounts for 75% of all skin cancer-related deaths and current therapeutic strategies are not effective in advanced disease. In the current study, we have investigated the efficacy of orally active small-molecule antagonist targeting CXCR2/CXCR1. EXPERIMENTAL DESIGN: Human A375SM melanoma cells were treated with SCH-479833 or SCH-527123, and their effect on proliferation, motility, and invasion was evaluated in vitro. We examined the downstream signaling events in the cells following treatment with antagonists. For in vivo studies, A375SM cells were implanted subcutaneously into athymic nude mice followed by administration of SCH-479833, SCH-527123, or hydroxypropyl-beta-cyclodextrin (20%) orally for 21 days and their effect on tumor growth and angiogenesis was evaluated. RESULTS: Our data show that SCH-479833 or SCH-527123 inhibited the melanoma cell proliferation, chemotaxis, and invasive potential in vitro. Treatment of melanoma cells with SCH-479833 or SCH-527123 also inhibited tumor growth. Histologic and histochemical analyses showed significant (P < 0.05) decreases in tumor cell proliferation and microvessel density in tumors. Moreover, we observed a significant increase in melanoma cell apoptosis in SCH-479833- or SCH-527123-treated animals compared with controls. CONCLUSION: Together, these studies show that selectively targeting CXCR2/CXCR1 with orally active small-molecule inhibitors is a promising therapeutic approach for inhibiting melanoma growth and angiogenesis. Substance P analogues, including [D-Arg(1),D-Trp(5,7,9),Leu(11)]SP (SPA) are broad-spectrum G protein-coupled receptor (GPCR) antagonists that have potential antitumorigenic activities, although the mechanism(s) are not completely understood. Here, we examined the effects of SPA in ductal pancreatic cancers that express multiple GPCRs for mitogenic agonists and also produce proangiogenic chemokines. Using HPAF-II, a well-differentiated pancreatic cancer cell line as our model system, we showed that SPA inhibited multiple neuropeptide-induced Ca(2+) mobilization, DNA synthesis, and anchorage-independent growth in vitro. SPA also significantly attenuated the growth of HPAF-II tumor xenografts in nude mice beyond the treatment period. Interestingly, SPA markedly increased apoptosis but moderately decreased proliferation marker, Ki-67 in the tumor xenografts implying additional mechanism(s) for the significant growth inhibitory effect observed in vivo. HPAF-II cells express ELR(+) CXC chemokines, including IL-8/CXCL8, which bind to CXCR2 (a member of GPCR superfamily) and promote angiogenesis in multiple cancers, including pancreatic cancer. SPA inhibited CXCR2-mediated Ca(2+) mobilization and blocked specifically IL-8/CXCL8-induced angiogenesis in rat corneal micropocket assay in vivo. A salient feature of the results presented here is that SPA markedly reduced tumor-associated angiogenesis in the HPAF-II xenografts in vivo. Our results show that SPA, a broad-spectrum GPCR antagonist attenuates tumor growth in pancreatic cancer via a dual mechanism involving both the antiproliferative and antiangiogenic properties. We conclude that this novel dual-inhibitory property of SPA could be of significant therapeutic value in pancreatic cancer, when used in combination with other antiproliferative and/or antiangiogenic agents. Chemotherapy-induced interleukin-8 (IL-8) signaling reduces the sensitivity of prostate cancer cells to undergo apoptosis. In this study, we investigated how endogenous and drug-induced IL-8 signaling altered the extrinsic apoptosis pathway by determining the sensitivity of LNCaP and PC3 cells to administration of the death receptor agonist tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). TRAIL induced concentration-dependent decreases in LNCaP and PC3 cell viability, coincident with increased levels of apoptosis and the potentiation of IL-8 secretion. Administration of recombinant human IL-8 was shown to increase the mRNA transcript levels and expression of c-FLIP(L) and c-FLIP(S), two isoforms of the endogenous caspase-8 inhibitor. Pretreatment with the CXCR2 antagonist AZ10397767 significantly attenuated IL-8-induced c-FLIP mRNA up-regulation whereas inhibition of androgen receptor- and/or nuclear factor-kappaB-mediated transcription attenuated IL-8-induced c-FLIP expression in LNCaP and PC3 cells, respectively. Inhibition of c-FLIP expression was shown to induce spontaneous apoptosis in both cell lines and to sensitize these prostate cancer cells to treatment with TRAIL, oxaliplatin, and docetaxel. Coadministration of AZ10397767 also increased the sensitivity of PC3 cells to the apoptosis-inducing effects of recombinant TRAIL, most likely due to the ability of this antagonist to block TRAIL- and IL-8-induced up-regulation of c-FLIP in these cells. We conclude that endogenous and TRAIL-induced IL-8 signaling can modulate the extrinsic apoptosis pathway in prostate cancer cells through direct transcriptional regulation of c-FLIP. Therefore, targeted inhibition of IL-8 signaling or c-FLIP expression in prostate cancer may be an attractive therapeutic strategy to sensitize this stage of disease to chemotherapy. BACKGROUND: The current study was undertaken to characterize the effect of anti-metabolites on inducing CXCL8 signaling and determining whether the constitutive and/or drug-induced CXCL8 signaling in metastatic prostate cancer (CaP) cells modulates their sensitivity to this class of agent. METHODS: The response of metastatic CaP cells to 5-Fluorouracil (5-FU), Pemetrexed or Tomudex was determined using cell count assays, flow cytometry and PARP cleavage analysis. Quantitative-PCR, ELISA and immunoblots were employed to determine effects of drugs or CXCL8 administration on target gene/protein expression. RESULTS: Administration of 5-FU but not pemetrexed potentiated CXCL8 secretion and increased CXCR1 and CXCR2 gene expression in metastatic PC3 cells. Consistent with this, the inhibition of CXCL8 signaling using a CXCR2 antagonist, AZ10397767, increased the cytotoxicity of 5-FU by 4-fold (P<0.001), and increased 5-FU-induced apoptosis in PC3 cells (P<0.01). In contrast, while administration of AZ10397767 had no effect on the sensitivity of pemetrexed, the CXCR2 antagonist exerted the greatest effect in increasing the sensitivity of PC3 cells to Tomudex, a directed thymidylate synthase (TS) inhibitor. Subsequent experiments confirmed that administration of recombinant human CXCL8 increased TS expression, a response mediated in part by the CXCR2 receptor. Moreover, siRNA-mediated knockdown of the CXCL8-target gene Bcl-2 increased the sensitivity of PC3 cells to 5-FU. CONCLUSIONS: CXCL8 signaling provides a selective resistance of metastatic prostate cancer cells to specific anti-metabolites by promoting a target-associated resistance, in addition to underpinning an evasion of treatment-induced apoptosis. Molecular analysis of CCR5, the cardinal coreceptor for HIV-1 infection, has implicated the N-terminal extracellular domain (N-ter) and regions vicinal to the second extracellular loop (ECL2) in this activity. It was shown that residues in the N-ter are necessary for binding of the physiologic ligands, RANTES (CCL5) and MIP-1 alpha (CCL3). vMIP-II, encoded by the Kaposi's sarcoma-associated herpesvirus, is a high affinity CCR5 antagonist, but lacks efficacy as a coreceptor inhibitor. Therefore, we compared the mechanism for engagement by vMIP-II of CCR5 to its interaction with physiologic ligands. RANTES, MIP-1 alpha, and vMIP-II bound CCR5 at high affinity, but demonstrated partial cross-competition. Characterization of 15 CCR5 alanine scanning mutants of charged extracellular amino acids revealed that alteration of acidic residues in the distal N-ter abrogated binding of RANTES, MIP-1 alpha, and vMIP-II. Whereas mutation of residues in ECL2 of CCR5 dramatically reduced the binding of RANTES and MIP-1 alpha and their ability to induce signaling, interaction with vMIP-II was not altered by any mutation in the exoloops of the receptor. Paradoxically, monoclonal antibodies to N-ter epitopes did not block chemokine binding, but those mapped to ECL2 were effective inhibitors. A CCR5 chimera with the distal N-ter residues of CXCR2 bound MIP-1 alpha and vMIP-II with an affinity similar to that of the wild-type receptor. Engagement of CCR5 by vMIP-II, but not RANTES or MIP-1 alpha blocked the binding of monoclonal antibodies to the receptor, providing additional evidence for a distinct mechanism for viral chemokine binding. Analysis of the coreceptor activity of randomly generated mouse-human CCR5 chimeras implicated residues in ECL2 between H173 and V197 in this function. RANTES, but not vMIP-II blocked CCR5 M-tropic coreceptor activity in the fusion assay. The insensitivity of vMIP-II binding to mutations in ECL2 provides a potential rationale to its inefficiency as an antagonist of CCR5 coreceptor activity. These findings suggest that the molecular anatomy of CCR5 binding plays a critical role in antagonism of coreceptor activity. Increased expression of lymphangiogenesis factors VEGF-C/D and heparanase has been correlated with the invasion of cancer. Furthermore, chemokines may modify matrix to facilitate metastasis, and they are associated with VEGF-C and heparanase. The chemokine CXCL7 binds heparin and the G-protein-linked receptor CXCR2. We investigated the effect of CXCR2 blockade on the expression of VEGF-C/D, heparanase, and on invasion. CXCL7 siRNA and a specific antagonist of CXCR2 (SB225002) were used to treat CXCL7 stably transfected MCF10AT cells. Matrigel invasion assays were performed. VEGF-C/D expression and secretion were determined by real-time PCR and ELISA assay, and heparanase activity was quantified by ELISA. SB225002 blocked VEGF-C/D expression and secretion (P < .01). CXCL7 siRNA knockdown decreased heparanase (P < .01). Both SB225002 and CXCL7 siRNA reduced the Matrigel invasion (P < .01). The MAP kinase signaling pathway was not involved. The CXCL7/CXCR2 axis is important for cell invasion and the expression of VEGF-C/D and heparanase, all linked to invasion. Growth-related oncogene (GRO), a member of the CXC chemokine subfamily, plays a major role in inflammation and wound healing. CXC chemokines have been found to be associated with tumorigenesis, angiogenesis, and metastasis. Although elevated expression of GRO has been reported in several human cancers, the expression and role of GRO and its receptor, CXCR2, in esophageal cancer are poorly understood. This study used real-time reverse transcription-PCR (RT-PCR) and immunohistochemical approaches to show that GROalpha, GRObeta, and CXCR2 are up-regulated in esophageal tumor tissue. Furthermore, GROalpha, GRObeta, and CXCR2 are constitutively expressed in WHCO1, an esophageal cancer cell line that was used as a model system here. GRObeta enhances transcription of EGR-1, via the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway, which can be blocked by a specific antagonist of CXCR2 (SB 225002) or specific antibody to GRObeta. WHCO1 cells treated with SB 225002 exhibited a 40% reduction in cell proliferation. A stable WHCO1 GROalpha RNA interference (RNAi) clone displayed a 43% reduction in GROalpha mRNA levels as determined by real-time RT-PCR, reduced levels of GROalpha by fluorescence microscopy, and a 60% reduction in the levels of phosphorylated ERK1/2. A stable clone expressing GRObeta RNAi displayed >95% reduction in GRObeta mRNA levels, reduced levels of GRObeta by fluorescence microscopy, and an 80% reduction in the levels of phosphorylated ERK1/2. Moreover, these GROalpha RNAi- and GRObeta RNAi-expressing clones displayed a 20% and 50% decrease in cell proliferation, respectively. Our results suggest that GROalpha-CXCR2 and GRObeta-CXCR2 signaling contributes significantly to esophageal cancer cell proliferation and that this autocrine signaling pathway may be involved in esophageal tumorigenesis.

What is Snord116?

SNORD116 is a small nucleolar (sno) RNA gene cluster (HBII-85) implicated as a major contributor the Prader-Willi phenotype. SNORD116 genes appears to be responsible for the major features of PWS. SNORD116 is a paternally expressed box C/D snoRNA gene cluster. The mouse C/D box snoRNA MBII-85 (SNORD116) is processed into at least five shorter RNAs using processing sites near known functional elements of C/D box snoRNAs. Snord116 expression in the medial hypothalamus, particularly within nuclei that are part of feeding circuitry. High expression of Snord116 was evident in the paraventricular (PVN) and ventromedial (VMH) nuclei, but particularly prevalent in the arcuate nucleus (ARC) according to in situ hybridization. Snord116 expression level in ventral hypothalamic dissections including ARC was significantly greater (by 2-fold) than that in cortex; and its expression level in dorsal hypothalamic dissections including PVN was double that in cortex. The enhanced expression pattern of Snord116 in hypothalamic nuclei was observed at weaning and young adult stages, but less obvious neonatally when expression was significantly more widespread. Therefore the expression of Snord116 likely is regulated developmentally. Snord116del mice with paternally derived deletion lack expression of this snoRNA. They have early-onset postnatal growth deficiency, but normal fertility and lifespan. While pituitary structure and somatotrophs are normal, liver Igf1 mRNA is decreased. In cognitive and behavior tests, Snord116del mice are deficient in motor learning and have increased anxiety. Around three months of age, they develop hyperphagia, but stay lean on regular and high-fat diet. On reduced caloric intake, Snord116del mice maintain their weight better than wild-type littermates, excluding increased energy requirement as a cause of hyperphagia. Normal compensatory feeding after fasting, and ability to maintain body temperature in the cold indicate normal energy homeostasis regulation. Metabolic chamber studies reveal that Snord116del mice maintain energy homeostasis by altered fuel usage. Prolonged mealtime and increased circulating ghrelin indicate a defect in meal termination mechanism. Snord116del mice, the first snoRNA deletion animal model, reveal a novel role for a non-coding RNA in growth and feeding regulation.

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Genetic analyses were performed in a male patient with suspected Prader-Willi syndrome who presented with hypogonadism, excessive eating, central obesity, small hands and feet and cognition within the low normal range. However, he had no neonatal hypotonia or feeding problems during infancy. Chromosome analysis showed a normal male karyotype. Further analysis with array-CGH identified a mosaic 847 kb deletion in 15q11-q13, including SNURF-SNRPN, the snoRNA gene clusters SNORD116 (HBII-85), SNORD115, (HBII-52), SNORD109 A and B (HBII-438A and B), SNORD64 (HBII-13), and NPAP1 (C15ORF2). MLPA confirmed the deletion and the results were compatible with a paternal origin. Metaphase-FISH verified the mosaicism with the deletion present in 58% of leukocytes analyzed. Three smaller deletions in this region have previously been reported in patients with Prader-Willi syndrome phenotype. All three deletions included SNORD116, but only two encompassed parts of SNURF-SNRPN, implicating SNORD116 as the major contributor to the Prader-Willi phenotype. Our case adds further information about genotype-phenotype correlation and supports the hypothesis that SNORD116 plays a major role in the pathogenesis of Prader-Willi syndrome. Furthermore, it examplifies diagnostic difficulties in atypical cases and illustrates the need for additional testing methods when Prader-Willi syndrome is suspected. The Prader-Willi syndrome (PWS) region in 15q11q13 harbours a cluster of imprinted genes expressed from the paternal chromosome only. Whereas loss of function of the SNORD116 genes appears to be responsible for the major features of PWS, the role of the other genes is less clear. One of these genes is C15orf2, which has no orthologues in rodents, but appears to be under strong positive selection in primates. C15orf2 encodes a 1156 amino acid protein with six nuclear localisation sequences. By protein BLAST analysis and InterProScan signature recognition search, we found sequence similarity of C15orf2 to the nuclear pore complex (NPC) protein POM121. To determine whether C15orf2 is located at nuclear pores, we generated a stable cell line that inducibly expresses FLAG-tagged C15orf2 and performed immunocytochemical studies. We found that C15orf2 is present at the nuclear periphery, where it colocalizes with NPCs and nuclear lamins. At very high expression levels, we observed invaginations of the nuclear envelope. Extending these observations to three-dimensional structured illumination microscopy, which achieves an 8-fold improved volumetric resolution over conventional imaging, we saw that C15orf2 is located at the inner face of the nuclear envelope where it strongly associates with the NPC. In nuclear envelope isolation and fractionation experiments, we detected C15orf2 in the NPC and lamina fractions. These experiments for the first time demonstrate that C15orf2 is part of the NPC or its associated molecular networks. Based on our findings, we propose 'Nuclear pore associated protein 1' as the new name for C15orf2. Prader-Willi syndrome (PWS) is a neurobehavioral disorder manifested by infantile hypotonia and feeding difficulties in infancy, followed by morbid obesity secondary to hyperphagia. It is caused by deficiency of paternally expressed transcript(s) within the human chromosome region 15q11.2. PWS patients harboring balanced chromosomal translocations with breakpoints within small nuclear ribonucleoprotein polypeptide N (SNRPN) have provided indirect evidence for a role for the imprinted C/D box containing small nucleolar RNA (snoRNA) genes encoded downstream of SNRPN. In addition, recently published data provide strong evidence in support of a role for the snoRNA SNORD116 cluster (HBII-85) in PWS etiology. In this study, we performed detailed phenotypic, cytogenetic, and molecular analyses including chromosome analysis, array comparative genomic hybridization (array CGH), expression studies, and single-nucleotide polymorphism (SNP) genotyping for parent-of-origin determination of the 15q11.2 microdeletion on an 11-year-old child expressing the major components of the PWS phenotype. This child had an ∼236.29 kb microdeletion at 15q11.2 within the larger Prader-Willi/Angelman syndrome critical region that included the SNORD116 cluster of snoRNAs. Analysis of SNP genotypes in proband and mother provided evidence in support of the deletion being on the paternal chromosome 15. This child also met most of the major PWS diagnostic criteria including infantile hypotonia, early-onset morbid obesity, and hypogonadism. Identification and characterization of this case provide unequivocal evidence for a critical role for the SNORD116 snoRNA molecules in PWS pathogenesis. Array CGH testing for genomic copy-number changes in cases with complex phenotypes is proving to be invaluable in detecting novel alterations and enabling better genotype-phenotype correlations. The imprinted Snurf-Snrpn chromosomal domain contains two large arrays of tandemly repeated, paternally expressed box C/D small-nucleolar RNA (snoRNA) genes: the SNORD115 (H/MBII-52) and SNORD116 (H/MBII-85) gene clusters believed to play key roles in the fine-tuning of serotonin receptor (5-HT2C) pre-mRNA processing and in the etiology of the Prader-Willi Syndrome (PWS), respectively. SNORD115 and SNORD116 were recently proposed to undergo significant conversion into shorter RNA species, the so-called psnoRNAs. Here, we provide evidence that argues against the existence of abundant psnoRNAs in human or mouse brain. Instead, we characterize a previously unsuspected low-abundance, fibrillarin-associated SNORD115-derived smaller RNA species. Based on these findings, we strongly recommend that PWS-encoded SNORD115 and SNORD116 be considered as bona fide box C/D snoRNAs.

What is the functional role of the protein Drp1?

Drp1 is involved in the regulation of mitochondrial fission.

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Bcl-2/adenovirus E1B 19-kDa interacting protein 1 (BNIP1), which is predominantly localized to the endoplasmic reticulum (ER), is a pro-apoptotic Bcl-2 homology domain 3 (BH3)-only protein. Here, we show that the expression of BNIP1 induced not only a highly interconnected ER network but also mitochondrial fragmentation in a BH3 domain-dependent manner. Functional analysis demonstrated that BNIP1 expression increased dynamin-related protein 1 (Drp1) expression followed by the mitochondrial translocation of Drp1 and subsequent mitochondrial fission. Both BNIP1-induced mitochondrial fission and the translocation of Drp1 were abrogated by Bcl-2 overexpression. These results collectively indicate that ER-specific BNIP1 plays an important role in mitochondrial dynamics by modulating the mitochondrial fission protein Drp1 in a BH3 domain-dependent fashion. It is believed that mitochondrial dynamics is coordinated with endosomal traffic rates during cytoskeletal remodeling, but the mechanisms involved are largely unknown. The adenovirus early region 4 ORF4 protein (E4orf4) subverts signaling by Src family kinases (SFK) to perturb cellular morphology, membrane traffic, and organellar dynamics and to trigger cell death. Using E4orf4 as a model, we uncovered a functional connection between mitochondria-shaping proteins and the small GTPase Rab11a, a key regulator of polarized transport via recycling endosomes. We found that E4orf4 induced dramatic changes in the morphology of mitochondria along with their mobilization at the vicinity of a polarized actin network typifying E4orf4 action, in a manner controlled by SFK and Rab11a. Mitochondrial remodeling was associated with increased proximity between Rab11a and mitochondrial membranes, changes in fusion-fission dynamics, and mitochondrial relocalization of the fission factor dynamin-related protein 1 (Drp1), which was regulated by the Rab11a effector protein FIP1/RCP. Knockdown of FIP1/RCP or inhibition of Drp1 markedly impaired mitochondrial remodeling and actin assembly, involving Rab11a-mediated mitochondrial dynamics in E4orf4-induced signaling. A similar mobilization of mitochondria near actin-rich structures was mediated by Rab11 and Drp1 in viral Src-transformed cells and contributed to the biogenesis of podosome rosettes. These findings suggest a role for Rab11a in the trafficking of Drp1 to mitochondria upon SFK activation and unravel a novel functional interplay between Rab11a and mitochondria during reshaping of the cell cytoskeleton, which would facilitate mitochondria redistribution near energy-requiring actin-rich structures. It is well established that mitochondrial fragmentation plays a key role in the pathogenesis of Alzheimer's disease (AD). Mitochondrial fission is mediated by dynamin-related protein 1 (Drp1), which is highly expressed in nervous system and regulated by various posttranslational modifications including phosphorylation. We identified glycogen synthase kinase (GSK)3β-dependent Drp1 phosphorylation at Ser(40) and Ser(44), which increases Drp1 GTPase activity and its mitochondrial distribution and could induce mitochondrial fragmentation. Moreover, neurons transfected with Ser(40)Ser(44) phosphomimic Drp1 showed increased mitochondria fragmentation and were more vulnerable to amyloid-β (Aβ)-induced apoptosis. Therefore, blocking GSK3β-induced Drp1 phosphorylation may be an effective way to protect neurons from Aβ toxicity. To address this, we designed and synthesized an artificial polypeptide named TAT-Drp1-SpS, which could specifically block GSK3β-induced Drp1 phosphorylation. Our results demonstrated that TAT-Drp1-SpS treatment could significantly reduce Aβ-induced neuronal apoptosis in cultured neurons. Notably, TAT-Drp1-SpS administration in hippocampus Cornu Ammonis 1 (CA1) region significantly reduced Aβ burden and rescued the memory deficits in AD transgenic mice. Although Aβ has multiple targets to exert its neurotoxicity, our findings suggested that GSK3β-induced mitochondrial fragmentation was, at least partially, mediated by Aβ toxicity and contribute to the pathogenesis of AD. Taken together, GSK3β-induced Drp1 phosphorylation provides a novel mechanism for mitochondrial fragmentation in AD, and our findings suggested a novel therapeutic strategy for AD. The mechano-enzyme dynamin-related protein 1 plays an important role in mitochondrial fission and is implicated in cell physiology. Dysregulation of Drp1 is associated with abnormal mitochondrial dynamics and neuronal damage. Drp1 shares structural and functional similarities with dynamin 1 with respect to domain organization, ability to self-assemble into spiral-like oligomers and GTP-cycle-dependent membrane scission. Structural studies of human dynamin-1 have greatly improved the understanding of this prototypical member of the dynamin superfamily. However, high-resolution structural information for full-length human Drp1 covering the GTPase domain, the middle domain and the GTPase effector domain (GED) is still lacking. In order to obtain mechanistic insights into the catalytic activity, a nucleotide-free GTPase-GED fusion protein of human Drp1 was expressed, purified and crystallized. Initial X-ray diffraction experiments yielded data to 2.67 Å resolution. The hexagonal-shaped crystals belonged to space group P2(1)2(1)2, with unit-cell parameters a = 53.59, b = 151.65, c = 43.53 Å, one molecule per asymmetric unit and a solvent content of 42%. Expression of selenomethionine-labelled protein is currently in progress. Here, the expression, purification, crystallization and X-ray diffraction analysis of the Drp1 GTPase-GED fusion protein are presented, which form a basis for more detailed structural and biophysical analysis. RATIONALE: The role of Parkin in hearts is unclear. Germ-line Parkin knockout mice have normal hearts, but Parkin is protective in cardiac ischemia. Parkin-mediated mitophagy is reportedly either irrelevant, or a major factor, in the lethal cardiomyopathy evoked by cardiac myocyte-specific interruption of dynamin-related protein 1 (Drp1)-mediated mitochondrial fission. OBJECTIVE: To understand the role of Parkin-mediated mitophagy in normal and mitochondrial fission-defective adult mouse hearts. METHODS AND RESULTS: Parkin mRNA and protein were present at low levels in normal mouse hearts, but were upregulated after cardiac myocyte-directed Drp1 gene deletion in adult mice. Alone, forced cardiac myocyte Parkin overexpression activated mitophagy without adverse effects. Likewise, cardiac myocyte-specific Parkin deletion evoked no adult cardiac phenotype, revealing no essential function for, and tolerance of, Parkin-mediated mitophagy in normal hearts. Concomitant conditional Parkin deletion with Drp1 ablation in adult mouse hearts prevented Parkin upregulation in mitochondria of fission-defective hearts, also increasing 6-week survival, improving ventricular ejection performance, mitigating adverse cardiac remodeling, and decreasing cardiac myocyte necrosis and replacement fibrosis. Underlying the Parkin knockout rescue was suppression of Drp1-induced hyper-mitophagy, assessed as ubiquitination of mitochondrial proteins and mitochondrial association of autophagosomal p62/sequestosome 1 (SQSTM1) and processed microtubule-associated protein 1 light chain 3 (LC3-II). Consequently, mitochondrial content of Drp1-deficient hearts was preserved. Parkin deletion did not alter characteristic mitochondrial enlargement of Drp1-deficient cardiac myocytes. CONCLUSIONS: Parkin is rare in normal hearts and dispensable for constitutive mitophagic quality control. Ablating Drp1 in adult mouse cardiac myocytes not only interrupts mitochondrial fission, but also markedly upregulates Parkin, thus provoking mitophagic mitochondrial depletion that contributes to the lethal cardiomyopathy. Dorsal root ganglia (DRG) neurons degenerate in diabetic neuropathy (DN) and exhibit mitochondrial damage. We studied mitochondria of cultured DRG neurons exposed to high glucose as an in vitro model of DN. High glucose sequentially increases the expression, activation and localization of the pro-apoptotic proteins Bim and Bax and the mitochondrial fission protein dynamin-regulated protein 1 (Drp1). High glucose causes association of Drp1/Bax, similar to other apoptotic stimuli. Collectively, these events promote mitochondrial fragmentation and reduce mitochondrial number, suggestive of apoptotic mitochondrial fission. Drp1 is also upregulated in DRG from experimentally diabetic rats, suggesting a role for mitochondrial fission in DN. Insulin-like growth factor-I (IGF-I) protects high glucose-treated DRG neurons by preventing mitochondrial accumulation of Bim and Bax but does not modulate Drp1 expression or localization. We propose that mitochondria are compromised by convergence of Bim/Bax proteins with Drp1, which contributes to high glucose-induced injury in DRG neurons. Mitochondria in cells comprise a tubulovesicular network shaped continuously by complementary fission and fusion events. The mammalian Drp1 protein plays a key role in fission, while Mfn1, Mfn2, and OPA1 are required for fusion. Shifts in the balance between these opposing processes can occur rapidly, indicating that modifications to these proteins may regulate mitochondrial membrane dynamics. We highlight posttranslational modifications of the mitochondrial fission protein Drp1, for which these regulatory mechanisms are best characterized. This dynamin-related GTPase undergoes a number of steps to mediate mitochondrial fission, including translocation from cytoplasm to the mitochondrial outer membrane, higher-order assembly into spirals, GTP hydrolysis associated with a conformational change and membrane deformation, and ultimately disassembly. Many of these steps may be influenced by covalent modification of Drp1. We discuss the dynamic nature of Drp1 modifications and how they contribute not only to the normal regulation of mitochondrial division, but also to neuropathologic processes. The mechanoenzyme dynamin-related protein 1 (Drp1) hydrolyzes GTP to power mitochondrial fission, a process required for organelle biogenesis, quality control, transport, and apoptosis. The pleckstrin homology domain of dynamin is essential for targeting to and severing of lipid tubules, but the function of the corresponding variable domain (VD, or insert B) of Drp1 is unknown. We replaced the VD of Drp1 with a panel of linker sequences of varying length and secondary structure composition and found that the VD is dispensable for mitochondrial recruitment, association with the Drp1-anchoring protein Mff (mitochondrial fission factor), and basal and protonophore-induced mitochondrial fragmentation. Indeed, several ΔVD mutants constitutively localized to the outer mitochondrial membrane (OMM) and fragmented mitochondria more efficiently than wild-type Drp1. Consistent with an autoinhibitory role of the VD, we identified Arg-376 in the Drp1 stalk domain as necessary for Mff interaction, assembly into spirals, and mitochondrial fission. Switching the length of N- and C-terminal α-helical segments in the VD-replacing linker converted Drp1 from constitutively active and OMM-localized to inactive and cytosolic. Other hypoactive ΔVD mutants formed stable and characteristically shaped aggregates, including extended filaments. Phosphorylation of a PKA site bordering the VD disassembled the filamentous ΔVD mutant and accelerated cytosolic diffusion of full-length Drp1. We propose a model for regulation of Drp1-dependent mitochondrial fission, in which posttranslational modifications in or near the VD alter the conformation of a membrane-proximal oligomerization interface to influence Drp1 assembly rate and/or geometry. This in turn modulates Arg-376-dependent OMM targeting of Drp1 via multivalent interactions with Mff. Dynamin-Related Protein 1 (Drp1), a large GTPase of the dynamin superfamily, is required for mitochondrial fission in healthy and apoptotic cells. Drp1 activation is a complex process that involves translocation from the cytosol to the mitochondrial outer membrane (MOM) and assembly into rings/spirals at the MOM, leading to membrane constriction/division. Similar to dynamins, Drp1 contains GTPase (G), bundle signaling element (BSE) and stalk domains. However, instead of the lipid-interacting Pleckstrin Homology (PH) domain present in the dynamins, Drp1 contains the so-called B insert or variable domain that has been suggested to play an important role in Drp1 regulation. Different proteins have been implicated in Drp1 recruitment to the MOM, although how MOM-localized Drp1 acquires its fully functional status remains poorly understood. We found that Drp1 can interact with pure lipid bilayers enriched in the mitochondrion-specific phospholipid cardiolipin (CL). Building on our previous study, we now explore the specificity and functional consequences of this interaction. We show that a four lysine module located within the B insert of Drp1 interacts preferentially with CL over other anionic lipids. This interaction dramatically enhances Drp1 oligomerization and assembly-stimulated GTP hydrolysis. Our results add significantly to a growing body of evidence indicating that CL is an important regulator of many essential mitochondrial functions. AIMS: Glucocorticoids, such as dexamethasone, enhance hepatic energy metabolism and gluconeogenesis partly through changes in mitochondrial function. Mitochondrial function is influenced by the balance between mitochondrial fusion and fission events. However, whether glucocorticoids modulate mitochondrial function through the regulation of mitochondrial dynamics is currently unknown. RESULTS: Here, we report that the effects of dexamethasone on mitochondrial function and gluconeogenesis in hepatoma cells are dependent on the mitochondrial fission protein dynamin-related protein 1 (Drp1). Dexamethasone increased routine oxygen consumption, maximal respiratory capacity, superoxide anion, proton leak, and gluconeogenesis in hepatoma cells. Under these conditions, dexamethasone altered mitochondrial morphology, which was paralleled by a large increase in Drp1 expression, and reduced mitofusin 1 (Mfn1) and Mfn2. In vivo dexamethasone treatment also enhanced Drp1 expression in mouse liver. On the basis of these observations, we analyzed the dependence on the Drp1 function of dexamethasone effects on mitochondrial respiration and gluconeogenesis. We show that the increase in mitochondrial respiration and gluconeogenesis induced by dexamethasone are hampered by the inhibition of Drp1 function. INNOVATION: Our findings provide the first evidence that the effects of glucocorticoids on hepatic metabolism require the mitochondrial fission protein Drp1. CONCLUSION: In summary, we demonstrate that the mitochondrial effects of dexamethasone both on mitochondrial respiration and on the gluconeogenic pathway depend on Drp1. Mitochondrial functions are altered in many human diseases including cancer. Development of mitochondria-targeted therapies, either through restoring normal mitochondrial function or promoting mitochondrial-induced cell death, is one of the attractive strategies to improve the outcome of cancer treatment. Recent advances have revealed the important functional involvement of mitochondrial dynamics in cancer biology. Dynamin-related protein 1 (Drp1), a member of the dynamin family of GTPases required for mitochondrial fission, has been found upregulated in certain types of cancers, such as lung and breast cancers. In addition, the roles of Drp1 in cell cycle progression, genome instability, cell migration and apoptosis in cancer cells have also been recently uncovered. These findings raise the possibility of targeting Drp1-mediated mitochondrial fission as an effective therapy for treating cancer. This article explores the function of Drp1 in cancer cells and discusses the theoretical basis for the development of potential targeted therapy. Mitochondria are highly dynamic and undergo constant fusion and fission that are essential for maintaining physiological functions of cells. Although dysfunction of mitochondria has been implicated in tumorigenesis, little is known about the roles of mitochondrial dynamics in metastasis, the major cause of cancer death. In the present study, we found a marked upregulation of mitochondrial fission protein dynamin-related protein 1 (Drp1) expression in human invasive breast carcinoma and metastases to lymph nodes. Compared with non-metastatic breast cancer cells, mitochondria also were more fragmented in metastatic breast cancer cells that express higher levels of total and active Drp1 and less mitochondrial fusion protein 1 (Mfn1). Silencing Drp1 or overexpression of Mfn1 resulted in mitochondria elongation or clusters, respectively, and significantly suppressed metastatic abilities of breast cancer cells. In contrast, silencing Mfn proteins led to mitochondrial fragmentation and enhanced metastatic abilities of breast cancer cells. Interestingly, these manipulations of mitochondrial dynamics altered the subcellular distribution of mitochondria in breast cancer cells. For example, silencing Drp1 or overexpression of Mfn1 inhibited lamellipodia formation, a key step for cancer metastasis, and suppressed chemoattractant-induced recruitment of mitochondria to lamellipodial regions. Conversely, silencing Mfn proteins resulted in more cell spreading and lamellipodia formation, causing accumulation of more mitochondria in lamellipodia regions. More importantly, treatment with a mitochondrial uncoupling agent or adenosine triphosphate synthesis inhibitor reduced lamellipodia formation and decreased breast cancer cell migration and invasion, suggesting a functional importance of mitochondria in breast cancer metastasis. Together, our findings show a new role and mechanism for regulation of cancer cell migration and invasion by mitochondrial dynamics. Thus targeting dysregulated Drp1-dependent mitochondrial fission may provide a novel strategy for suppressing breast cancer metastasis. Drp1 is a dynamin-like GTPase that mediates mitochondrial and peroxisomal division in a process dependent on self-assembly and coupled to GTP hydrolysis. Despite the link between Drp1 malfunction and human disease, the molecular details of its membrane activity remain poorly understood. Here we reconstituted and directly visualized Drp1 activity in giant unilamellar vesicles. We quantified the effect of lipid composition and GTP on membrane binding and remodeling activity by fluorescence confocal microscopy and flow cytometry. In contrast to other dynamin relatives, Drp1 bound to both curved and flat membranes even in the absence of nucleotides. We also found that Drp1 induced membrane tubulation that was stimulated by cardiolipin. Moreover, Drp1 promoted membrane tethering dependent on the intrinsic curvature of the membrane lipids and on GTP. Interestingly, Drp1 concentrated at membrane contact surfaces and, in the presence of GTP, formed discrete clusters on the vesicles. Our findings support a role of Drp1 not only in the formation of lipid tubes but also on the stabilization of tightly apposed membranes, which are intermediate states in the process of mitochondrial fission. RATIONALE: Closure of the ductus arteriosus (DA) is essential for the transition from fetal to neonatal patterns of circulation. Initial PO2-dependent vasoconstriction causes functional DA closure within minutes. Within days a fibrogenic, proliferative mechanism causes anatomic closure. Though modulated by endothelial-derived vasodilators and constrictors, O2 sensing is intrinsic to ductal smooth muscle cells and oxygen-induced DA constriction persists in the absence of endothelium, endothelin, and cyclooxygenase mediators. O2 increases mitochondrial-derived H2O2, which constricts ductal smooth muscle cells by raising intracellular calcium and activating rho kinase. However, the mechanism by which oxygen changes mitochondrial function is unknown. OBJECTIVE: The purpose of this study was to determine whether mitochondrial fission is crucial for O2-induced DA constriction and closure. METHODS AND RESULTS: Using DA harvested from 30 term infants during correction of congenital heart disease, as well as DA from term rabbits, we demonstrate that mitochondrial fission is crucial for O2-induced constriction and closure. O2 rapidly (<5 minutes) causes mitochondrial fission by a cyclin-dependent kinase- mediated phosphorylation of dynamin-related protein 1 (Drp1) at serine 616. Fission triggers a metabolic shift in the ductal smooth muscle cells that activates pyruvate dehydrogenase and increases mitochondrial H2O2 production. Subsequently, fission increases complex I activity. Mitochondrial-targeted catalase overexpression eliminates PO2-induced increases in mitochondrial-derived H2O2 and cytosolic calcium. The small molecule Drp1 inhibitor, Mdivi-1, and siDRP1 yield concordant results, inhibiting O2-induced constriction (without altering the response to phenylephrine or KCl) and preventing O2-induced increases in oxidative metabolism, cytosolic calcium, and ductal smooth muscle cells proliferation. Prolonged Drp1 inhibition reduces DA closure in a tissue culture model. CONCLUSIONS: Mitochondrial fission is an obligatory, early step in mammalian O2 sensing and offers a promising target for modulating DA patency. In response to many apoptotic stimuli, oligomerization of Bax is essential for mitochondrial outer membrane permeabilization and the ensuing release of cytochrome c. These events are accompanied by mitochondrial fission that appears to require Drp1, a large GTPase of the dynamin superfamily. Loss of Drp1 leads to decreased cytochrome c release by a mechanism that is poorly understood. Here we show that Drp1 stimulates tBid-induced Bax oligomerization and cytochrome c release by promoting tethering and hemifusion of membranes in vitro. This function of Drp1 is independent of its GTPase activity and relies on arginine 247 and the presence of cardiolipin in membranes. In cells, overexpression of Drp1 R247A/E delays Bax oligomerization and cell death. Our findings uncover a function of Drp1 and provide insight into the mechanism of Bax oligomerization. We recently reported increased mitochondrial fission and decreased fusion, increased amyloid beta (Aβ) interaction with the mitochondrial fission protein Drp1, increased mitochondrial fragmentation, impaired axonal transport of mitochondria and synaptic degeneration in neurons affected by AD. In the present study, we extended our previous investigations to determine whether phosphorylated tau interacts with Drp1 and to elucidate mitochondrial damage in the progression of AD. We also investigated GTPase activity, which is critical for mitochondrial fragmentation, in postmortem brain tissues from patients with AD and brain tissues from APP, APP/PS1 and 3XTg.AD mice. Using co-immunoprecipitation and immunofluorescence analyses, for the first time, we demonstrated the physical interaction between phosphorylated tau and Drp1. Mitochondrial fission-linked GTPase activity was significantly elevated in the postmortem frontal cortex tissues from AD patients and cortical tissues from APP, APP/PS1 and 3XTg.AD mice. On the basis of these findings, we conclude that Drp1 interacts with Aβ and phosphorylated tau, likely leading to excessive mitochondrial fragmentation, and mitochondrial and synaptic deficiencies, ultimately possibly leading to neuronal damage and cognitive decline. Treatment designed to reduce the expression of Drp1, Aβ and/or phosphorylated tau may decrease the interaction between Drp1 and phosphorylated tau and the interaction between Drp1 and Aβ, conferring protection to neurons from toxic insults of excessive Drp1, Aβ and/or phosphorylated tau. The endoplasmic reticulum (ER) can elicit proapoptotic signalling that results in transmission of Ca(2+) to the mitochondria, which in turn stimulates recruitment of the fission enzyme DRP1 to the surface of the organelle. Here, we show that BH3-only BIK activates this pathway at the ER in intact cells, resulting in mitochondrial fragmentation but little release of cytochrome c to the cytosol. The BIK-induced transformations in mitochondria are dynamic in nature and involve DRP1-dependent remodelling and opening of cristae, where the major stores of cytochrome c reside. This novel function for DRP1 is distinct from its recognized role in regulating mitochondrial fission. Selective permeabilization of the outer membrane with digitonin confirmed that BIK stimulation results in mobilization of intramitochondrial cytochrome c. Of note, BIK can cooperate with a weak BH3-only protein that targets mitochondria, such as NOXA, to activate BAX by a mechanism that is independent of DRP1 enzyme activity. When expressed together, BIK and NOXA cause rapid release of mobilized cytochrome c and activation of caspases. Mitochondria are dynamic organelles forming a tubular network that is continuously fusing and dividing to control their morphology and functions. Recent literature has shed new light on a potential link between the dynamic behavior of mitochondria and muscle development. In this study, we investigate the role of mitochondrial fission factor dynamin-related protein 1 (Drp1) in myogenic differentiation. We found that differentiation of C2C12 myoblasts induced by serum starvation was accompanied by a gradual increase in Drp1 protein expression (to ∼350% up to 3 days) and a fast reduction of Drp1 phosphorylation at Ser-637 (to ∼30%) resulting in translocation of Drp1 protein from the cytosol to mitochondria. During differentiation, treatment of myoblasts with mitochondrial division inhibitor (mdivi-1), a specific inhibitor of Drp1 GTPase activity, caused extensive formation of elongated mitochondria, which coincided with increased apoptosis evidenced by both enhanced caspase-3 activity and increased number of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells. Furthermore, the mdivi-1-treated myotubes (day 3 in differentiation media) showed a reduction in mitochondrial DNA content, mitochondrial mass, and membrane potential in a dose-dependent manner indicating defects in mitochondrial biogenesis during myogenic differentiation. Most interestingly, mdivi-1 treatment significantly suppressed myotube formation in both C2C12 cells and primary myoblasts. Likewise, stable overexpression of a dominant negative mutant Drp1 (K38A) dramatically reduced myogenic differentiation. These data suggest that Drp-1-dependent mitochondrial division is a necessary step for successful myogenic differentiation, and perturbation of mitochondrial dynamics hinders normal mitochondrial adaptations during muscle development. Therefore, in the present study, we report a novel physiological role of mitochondrial dynamics in myogenic differentiation. RATIONALE: Both fusion and fission contribute to mitochondrial quality control. How unopposed fusion affects survival of cardiomyocytes and left ventricular function in the heart is poorly understood. OBJECTIVE: We investigated the role of dynamin-related protein 1 (Drp1), a GTPase that mediates mitochondrial fission, in mediating mitochondrial autophagy, ventricular function, and stress resistance in the heart. METHODS AND RESULTS: Drp1 downregulation induced mitochondrial elongation, accumulation of damaged mitochondria, and increased apoptosis in cardiomyocytes at baseline. Drp1 downregulation also suppressed autophagosome formation and autophagic flux at baseline and in response to glucose deprivation in cardiomyocytes. The lack of lysosomal translocation of mitochondrially targeted Keima indicates that Drp1 downregulation suppressed mitochondrial autophagy. Mitochondrial elongation and accumulation of damaged mitochondria were also observed in tamoxifen-inducible cardiac-specific Drp1 knockout mice. After Drp1 downregulation, cardiac-specific Drp1 knockout mice developed left ventricular dysfunction, preceded by mitochondrial dysfunction, and died within 13 weeks. Autophagic flux is significantly suppressed in cardiac-specific Drp1 knockout mice. Although left ventricular function in cardiac-specific Drp1 heterozygous knockout mice was normal at 12 weeks of age, left ventricular function decreased more severely after 48 hours of fasting, and the infarct size/area at risk after ischemia/reperfusion was significantly greater in cardiac-specific Drp1 heterozygous knockout than in control mice. CONCLUSIONS: Disruption of Drp1 induces mitochondrial elongation, inhibits mitochondrial autophagy, and causes mitochondrial dysfunction, thereby promoting cardiac dysfunction and increased susceptibility to ischemia/reperfusion. Author information: (1)Department of Protein Biochemistry, Institute of Life Science, Kurume University, Kurume, Japan. (2)Department of Protein Biochemistry, Institute of Life Science, Kurume University, Kurume, Japan Department of Physiology and Cell Biology, Tokyo Medical and Dental University, Tokyo, Japan. (3)Department of Physiology and Cell Biology, Tokyo Medical and Dental University, Tokyo, Japan. (4)Department of Medicine, Division of Cardiovascular Medicine, Kurume University School of Medicine, Kurume, Japan. (5)Cardiovascular Research Institute, Kurume University, Kurume, Japan. (6)Faculty of Life and Environmental Sciences, University of Tsukuba, Ibaraki, Japan. (7)Department of Medicine and Bioregulatory Science, Kyushu University, Fukuoka, Japan. (8)Department of Physiology and Cell Biology, Tokyo Medical and Dental University, Tokyo, Japan Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, Japan. (9)Department of Protein Biochemistry, Institute of Life Science, Kurume University, Kurume, Japan Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka, Japan. (10)Department of Protein Biochemistry, Institute of Life Science, Kurume University, Kurume, Japan Department of Physiology and Cell Biology, Tokyo Medical and Dental University, Tokyo, Japan [email protected]. BACKGROUND: Hypertension leads to cardiac hypertrophy as an adaptive response to increased workload. While initial development of hypertrophy is compensatory when contractile function is maintained, persistent stress on heart leads to deteriorated cardiac function and onset of heart failure. Mitochondrial dysfunction develops in the failing heart; however, whether it presents in compensatory cardiac hypertrophy is controversial. METHODS: Spontaneously hypertensive rats (SHRs) and age-matched normotensive Wistar Kyoto rats were used in the study. Mitochondrial function and remodeling-related mechanisms in the left ventricles were measured by enzyme activity tests, Western blots, and reverse transcriptase polymerase chain reaction. RESULTS: Compensatory cardiac hypertrophy in SHR was indicated by higher heart/weigh ratio, left ventricular systolic pressure and ±dp/dt(max) (P<.001, P<.05, and P<.01, respectively). Enzyme activities of mitochondrial complex I and II were significantly reduced (P<.05 and P<.01) in SHR in concert with decreased expression of complex subunits (P<.01 for NDUFS3, P=.068 for SDHB, and P<.05 for ATP5A1). Mitochondrial fission protein Drp1 was decreased (P<.05), while fusion protein OPA1 was increased (P<.01). Parkin and SirT1/AMPK-PGC-1α signaling, responsible for mitochondrial elimination and biogenesis respectively, were decreased in SHR (P<.01 for Parkin, P<.001 for SirT1 and p-AMPK). CONCLUSION: Our results implicated that mitochondrial function and remodeling, indicated by mitochondrial enzyme activities and remodeling-related molecules, were compromised in compensatory hypertrophied myocardium of the SHR hypertensive model. SUMMARY: Mitochondrial function in compensatory hypertrophied myocardium is controversial. Our present study found mitochondrial dysfunction in the left ventricle of spontaneously hypertensive rats, which was possibly a result of compromised mitochondrial remodeling including mitochondrial dynamics, elimination, and biogenesis.

Which is the genetic cause for the development of Fanconi anemia complementation group D1?

Fanconi anemia complementation group D1 (FANCD1) was shown to be induced by biallelic mutations in the BRCA2 breast-cancer-susceptibility gene.

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Fanconi Anemia (FA) is an autosomal recessive syndrome characterized by congenital abnormalities, progressive bone marrow failure, and susceptibility to cancer. FA has eight known complementation groups and is caused by mutations in at least seven genes. Biallelic BRCA2 mutations were shown recently to cause FA-D1. Monoallelic (heterozygous) BRCA2 mutations confer a high risk of breast cancer and are a major cause of familial breast cancer. To investigate whether heterozygous variants in other FA genes are high penetrance breast cancer susceptibility alleles, we screened germ-line DNA from 88 BRCA1/2-negative families, each with at least three cases of breast cancer, for mutations in FANCA, FANCC, FANCD2, FANCE, FANCF, and FANCG. Sixty-nine sequence variants were identified of which 25 were exonic. None of the exonic variants resulted in translational frameshifts or nonsense codons and 14 were polymorphisms documented previously. Of the remaining 11 exonic variants, 2 resulted in synonymous changes, and 7 were present in controls. Only 2 conservative missense variants, 1 in FANCA and 1 in FANCE, were each found in a single family and were not present in 300 controls. The results indicate that FA gene mutations, other than in BRCA2, are unlikely to be a frequent cause of highly penetrant breast cancer predisposition. Fanconi anemia (FA) is an inherited cancer-susceptibility disorder, characterized by genomic instability and hypersensitivity to DNA cross-linking agents. The discovery of biallelic BRCA2 mutations in the FA-D1 complementation group allows for the first time to study the characteristics of primary BRCA2-deficient human cells. FANCD1/BRCA2-deficient fibroblasts appeared hypersensitive to mitomycin C (MMC), slightly sensitive to methyl methane sulfonate (MMS), and like cells derived from other FA complementation groups, not sensitive to X-ray irradiation. However, unlike other FA cells, FA-D1 cells were slightly sensitive to UV irradiation. Despite the observed lack of X-ray sensitivity in cell survival, significant radioresistant DNA synthesis (RDS) was observed in the BRCA2-deficient fibroblasts but also in the FANCA-deficient fibroblasts, suggesting an impaired S-phase checkpoint. FA-D1/BRCA2 cells displayed greatly enhanced levels of spontaneous as well as MMC-induced chromosomal aberrations (CA), similar to cells deficient in homologous recombination (HR) and non-D1 FA cells. In contrast to Brca2-deficient rodent cells, FA-D1/BRCA2 cells showed normal sister chromatid exchange (SCE) levels, both spontaneous as well as after MMC treatment. Hence, these data indicate that human cells with biallelic BRCA2 mutations display typical features of both FA- and HR-deficient cells, which suggests that FANCD1/BRCA2 is part of the integrated FA/BRCA DNA damage response pathway but also controls other functions outside the FA pathway. Fanconi anemia is an inherited disease characterized by bone marrow failure, congenital malformations, and predisposition to cancer. The breast cancer susceptibility gene BRCA2 was recently found to be associated with Fanconi anemia complementation group D1 (FA-D1). We examined four kindreds afflicted with Fanconi anemia for the presence of germline BRCA2 mutations. One kindred, of Ashkenazi Jewish ancestry, had five members who were diagnosed with breast cancer and two cousins who were BRCA2*6174delT/C3069X compound heterozygotes and had Fanconi anemia and brain tumors. In another kindred of Ashkenazi Jewish and Lithuanian Catholic ancestry, a child with Fanconi anemia and a medulloblastoma was a BRCA2*6174delT/886delGT compound heterozygote. Two other kindreds each contained a Fanconi anemia-afflicted child who developed medulloblastoma; one child was of Latin American ancestry and a compound heterozygote for BRCA2*I2490T/ 5301insA and the other was African American and a compound heterozygote for BRCA2*Q3066X/E1308X. Median age of the Fanconi anemia-afflicted children at brain tumor diagnosis was 3.5 years. The co-occurrence of brain tumors, Fanconi anemia, and breast cancer observed in one of these kindreds constitutes a new syndromic association. Individuals who carry a germline BRCA2 mutation and who plan to have children with a partner of Ashkenazi Jewish descent should consider undergoing genetic counseling. Fanconi anemia (FA) is a rare autosomal recessive disorder characterized by congenital and developmental abnormalities, hypersensitivity to DNA cross-linking agents such as mitomycin C (MMC), and strong predisposition to acute myeloid leukemia (AML). In this article, we describe clinical and molecular findings in a boy with a severe FA phenotype who developed AML by the age of 2. Although he lacked a strong family history of cancer, he was subsequently shown to carry biallelic mutations in the FANCD1/BRCA2 gene. These included an IVS7 splice-site mutation, which is strongly associated with early AML in homozygous or compound heterozygous carrier status in FA-D1 patients. Myeloid leukemia cells from this patient have been maintained in culture for more than 1 year and have been designated as the SB1690CB cell line. Growth of SB1690CB is dependent on granulocyte macrophage colony stimulating factor or interleukin-3. This cell line has retained its MMC sensitivity and has undergone further spontaneous changes in the spectrum of cytogenetic aberrations compared with the primary leukemia. This is the second AML cell line derived from an FA-D1 patient and the first proof that malignant clones arising in FA patients can retain inherited MMC sensitivity. As FA-derived malignancies are normally not very responsive to treatment, this implies there are important mechanisms of acquiring correction of the cellular FA phenotype that would explain the poor chemoresponsiveness observed in FA-associated malignancies and might also play a role in the initiation and progression of cancer in the general population. Surprisingly, biallelic mutations in the BRCA2 breast-cancer-susceptibility gene were found in Fanconi anemia (FA), a rare hereditary disorder characterized by chromosomal instability, hypersensitivity to DNA cross-linking agents, and cancer susceptibility. This suggests that a defect in the FA pathway might predispose to familial breast cancer. A previously reported molecular interaction between BRCA1 and the FA protein, FANCD2, supports the hypothesis that both breast-cancer-susceptibility genes are components of the FA pathway, functioning in DNA-damage response. However, an alternative hypothesis, that group FA-D1 with mutated BRCA2 represents a FA-like syndrome that is involved in a pathway distinct from the FA pathway, cannot be excluded. Similar syndromes would also be expected when recombination genes, such as Rad51 and its paralogs, are mutated.

Which diseases are caused by mutations in Calsequestrin 2 (CASQ2) gene?

CASQ2 mutations are associated with autosomal recessive catecholaminergic polymorphic ventricular tachycardia (CPVT) and familial hypertrophic cardiomyopathy.

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Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an uncommon heritable disease presenting with syncope or sudden cardiac death. Two genes involved in calcium homeostasis, the ryanodine receptor gene and the calsequestrin 2 (CASQ2) gene, have been implicated in this disease. We describe a young man presenting with exercise-induced syncope, clinically diagnosed as CPVT. Genetic analysis revealed two mutations, p.Y55C (c.164A>G) and p.P308L (c.923C>T), in the CASQ2 gene. Subsequent familial analysis indicates a compound heterozygous form of inheritance. Mutations of two myocardial calcium signaling molecules, ryanodine receptor 2 (RYR2) and calsequestrin 2 (CASQ2), may cause catecholaminergic polymorphic ventricular tachycardia (CPVT), a severe inherited arrhythmic disease manifesting with salvoes of exercise-induced bidirectional and polymorphic tachycardias. We screened 12 Finnish CPVT probands for mutations in these genes and identified three novel RYR2 mutations (V2306I, P4902L, R4959Q), which were absent in unaffected and control individuals. Although no obvious disease-causing mutations were identified in the CASQ2 gene, the molecular screening revealed two novel amino-acid polymorphisms (T66A and V76M). The frequencies of these polymorphisms in 185 unrelated probands with long QT syndrome and in 280 healthy blood donors were not significantly different. These data, combined with our previous findings, show that RYR2 mutations are present in at least 6/16 (38%) of the catecholaminergic polymorphic ventricular tachycardia families, while CASQ2 mutations must be a rare cause of CPVT. Catecholaminergic polymorphic ventricular tachycardia is a familial cardiac arrhythmia that is related to RYR2 or CASQ2 gene mutation. It occurs in patients with structurally normal heart and causes exercise-emotion triggered syncope and sudden cardiac death. We present a 13 year-old girl with recurrent episodes of exercise-related syncope and prior history of sudden death in a first degree relative. Regulation of calcium flux in the heart is a key process that affects cardiac excitability and contractility. Degenerative diseases, such as coronary artery disease, have long been recognized to alter the physiology of intracellular calcium regulation, leading to contractile dysfunction or arrhythmias. Since the discovery of the first gene mutation associated with catecholaminergic polymorphic ventricular tachycardia (CPVT) in 2001, a new area of interest in this field has emerged--the genetic abnormalities of key components of the calcium regulatory system. Such anomalies cause a variety of genetic diseases characterized by the development of life-threatening arrhythmias in young individuals. In this Review, we provide an overview of the structural organization and the function of calcium-handling proteins and describe the mechanisms by which mutations determine the clinical phenotype. Firstly, we discuss mutations in the genes encoding the ryanodine receptor 2 (RYR2) and calsequestrin 2 (CASQ2). These proteins are pivotal to the regulation of calcium release from the sarcoplasmic reticulum, and mutations can cause CPVT. Secondly, we review defects in genes encoding proteins that form the voltage-dependent L-type calcium channel, which regulates calcium entry into myocytes. Mutations in these genes cause various phenotypes, including Timothy syndrome, Brugada syndrome, and early repolarization syndrome. The identification of mutations associated with 'calcium-handling diseases' has led to an improved understanding of the role of calcium in cardiac physiology. Catecholamine-induced polymorphic ventricular tachycardia (CPVT), a rare disease that occurs in subjects without obvious organic heart disease, is characterized by episodes of syncope, seizures, or sudden death in response to physiologic or emotional stress. This report reviews evidence that a missense mutation in the CASQ2 gene is associated with autosomal-recessive CPVT. RATIONALE: Catecholaminergic polymorphic ventricular tachycardia is an inherited disease that predisposes to cardiac arrest and sudden death. The disease is associated with mutations in the genes encoding for the cardiac ryanodine receptor (RyR2) and cardiac calsequestrin (CASQ2). CASQ2 mutations lead to a major loss of CASQ2 monomers, possibly because of enhanced degradation of the mutant protein. The decrease of CASQ2 is associated with a reduction in the levels of Triadin (TrD) and Junctin (JnC), two proteins that form, with CASQ2 and RyR2, a macromolecular complex devoted to control of calcium release from the sarcoplasmic reticulum. OBJECTIVE: We intended to evaluate whether viral gene transfer of wild-type CASQ2 may rescue the broad spectrum of abnormalities caused by mutant CASQ2. METHODS AND RESULTS: We used an adeno-associated serotype 9 viral vector to express a green fluorescent protein-tagged CASQ2 construct. Twenty weeks after intraperitoneal injection of the vector in neonate CASQ2 KO mice, we observed normalization of the levels of calsequestrin, triadin, and junctin, rescue of electrophysiological and ultrastructural abnormalities caused by CASQ2 ablation, and lack of life-threatening arrhythmias. CONCLUSIONS: We have proven the concept that induction of CASQ2 expression in knockout mice reverts the molecular, structural, and electric abnormalities and prevents life-threatening arrhythmias in CASQ2-defective catecholaminergic polymorphic ventricular tachycardia mice. These data support the view that development of CASQ2 viral gene transfer could have clinical application. BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal, rare hereditary disease with an estimated prevalence of 1:10 000. The genetic variants that cause CPVT are usually highly penetrant. To date, about 189 variants in 5 genes (RYR2, CASQ2, CALM1, TRND, and KCNJ2) have been associated with CPVT pathogenesis. METHODS AND RESULTS: The Exome Sequencing Project database (ESP; n=6503) was systematically searched for previously published missense and nonsense CPVT-associated variants reported in several comprehensive reviews and in 2 databases: The Human Gene Mutation Database and The Inherited Arrhythmias Database. We used 4 different prediction tools to assess all missense variants previously associated with CPVT and compared the prediction of protein damage between CPVT-associated variants identified in the ESP and those variants not identified in the ESP. We identified 11% of the variants previously associated with CPVT in the ESP population. In the literature, 57% of these variants were reported as novel disease-causing variants absent in the healthy control subjects. These putative CPVT variants were identified in 41 out of 6131 subjects in the ESP population, corresponding to a prevalence of CPVT of up to 1:150. Using an agreement of ≥3, in silico prediction tools showed a significantly higher frequency of damaging variants among the CPVT-associated variants not identified in the ESP database (83%) compared with those variants identified in the ESP (50%; P=0.021). CONCLUSIONS: We identified a substantial overrepresentation of CPVT-associated variants in a large exome database, suggesting that these variants are not necessarily the monogenic cause of CPVT. Catecholamine-induced polymorphic ventricular tachycardia (CPVT) is a familial disorder caused by cardiac ryanodine receptor type 2 (RyR2) or calsequestrin 2 (CASQ2) gene mutations. To define how CASQ2 mutations cause CPVT, we produced and studied mice carrying a human D307H missense mutation (CASQ(307/307)) or a CASQ2-null mutation (CASQ(DeltaE9/DeltaE9)). Both CASQ2 mutations caused identical consequences. Young mutant mice had structurally normal hearts but stress-induced ventricular arrhythmias; aging produced cardiac hypertrophy and reduced contractile function. Mutant myocytes had reduced CASQ2 and increased calreticulin and RyR2 (with normal phosphorylated proportions) but unchanged calstabin levels, as well as reduced total sarcoplasmic reticulum (SR) Ca(2+), prolonged Ca(2+) release, and delayed Ca(2+) reuptake. Stress further diminished Ca(2+) transients, elevated cytosolic Ca(2+), and triggered frequent, spontaneous SR Ca(2+) release. Treatment with Mg(2+), a RyR2 inhibitor, normalized myocyte Ca(2+) cycling and decreased CPVT in mutant mice, indicating RyR2 dysfunction was critical to mutant CASQ2 pathophysiology. We conclude that CPVT-causing CASQ2 missense mutations function as null alleles. In the absence of CASQ2, calreticulin, a fetal Ca(2+)-binding protein normally downregulated at birth, remains a prominent SR component. Adaptive changes to CASQ2 deficiency (increased posttranscriptional expression of calreticulin and RyR2) maintained electrical-mechanical coupling, but increased RyR2 leakiness, a paradoxical response further exacerbated by stress. The central role of RyR2 dysfunction in CASQ2 deficiency unifies the pathophysiologic mechanism underlying CPVT due to RyR2 or CASQ2 mutations and suggests a therapeutic approach for these inherited cardiac arrhythmias. Cardiac calsequestrin (Casq2) is the major Ca2+ binding protein in the sarcoplasmic reticulum, which is the principle Ca2+ storage organelle of cardiac muscle. During the last decade, experimental studies have provided new concepts on the role of Casq2 in the regulation of cardiac muscle Ca2+ handling. Furthermore, mutations in the gene encoding for cardiac calsequestrin, CASQ2, cause a rare but severe form of catecholaminergic polymorphic ventricular tachycardia (CPVT). Here, we review the physiology of Casq2 in cardiac Ca2+ handling and discuss pathophysiological mechanisms that lead to CPVT caused by CASQ2 mutations. We also describe the clinical aspects of CPVT and provide an update of its contemporary clinical management. BACKGROUND: The genetic background of catecholaminergic polymorphic ventricular tachycardia (CPVT) has been extensively investigated for the last decade in Western countries, but it remains unstudied in the Asian population. METHODS AND RESULTS: In 50 Japanese probands from unrelated families who satisfied clinical criteria for CPVT, genetic testing was conducted in all exons on 3 CPVT-related genes: cardiac ryanodine receptor 2 (RYR2), calsequestrin 2 (CASQ2) and inward rectifier potassium channel 2 (KCNJ2), and the clinical features between RYR2-genotyped and -non-genotyped patient groups were compared. Genetic and clinical evaluation was also done in 46 family members. In the genetic screening, 28 (18 novel) RYR2 (56.0%), 1 compound heterozygous CASQ2 (2.0%) and 1 KCNJ2 (2.0%) mutation carriers were identified. In the RYR2 mutation-positive group, the frequency of bidirectional ventricular tachycardia and the use of β-blockers were significantly higher than in the mutation-negative group. In contrast, there was no significant difference in supraventricular arrhythmias between the 2 groups. With regard to disease penetrance, the number of family members of RYR2-genotyped probands with a clinical diagnosis of CPVT was high. CONCLUSIONS: Thirty gene mutation carriers were found for 3 genes in 50 probands clinically diagnosed as having CPVT. The penetrance of CPVT phenotype was significantly higher in RYR2 mutation carriers, thus RYR2 gene screening in CPVT patients would be indispensable to prevent unexpected cardiac sudden death of young family members. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial cardiac arrhythmia that is related to RYR2 or CASQ2 gene mutation. It occurs in patients with structurally normal heart and causes exercise-emotion-triggered syncope and sudden cardiac death. We experienced a case of CPVT in an 11 year-old female patient who was admitted for sudden cardiovascular collapse. The initial electrocardiogram (ECG) on emergency department revealed ventricular fibrillation. After multiple defibrillations, sinus rhythm was restored. However, recurrent ventricular fibrillation occurred during insertion of nasogastric tube without sedation in coronary care unit. On ECG monitoring, bidirectional ventricular tachycardia occurred with sinus tachycardia and then degenerated into ventricular fibrillation. To our knowledge, there has been no previous case report of CPVT triggered by sinus tachycardia in Korea. Therefore, we report the case as well as a review of the literature. Cardiac excitation-contraction coupling occurs by a calcium ion-mediated mechanism in which the signal of action potential is converted into Ca2+ influx into the cardiomyocytes through the sarcolemmal L-type calcium channels. This is followed by Ca2+-induced release of additional Ca2+ ions from the lumen of the sarcoplasmic reticulum into the cytosol via type 2 ryanodine receptors (RyR2). RyR2 channels form large complexes with additional regulatory proteins, including FKBP12.6 and calsequestrin 2 (CASQ2). Catecholamines, released into the body fluids during emotional or physical stress, activate Ca2+-induced Ca2+ release by protein kinase A-mediated phosphorylation of RyR2. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an insidious, early-onset and highly malignant, inherited disorder characterized by effort-induced ventricular arrhythmias in the absence of structural alterations of the heart. At least some cases of sudden, unexplained death in young individuals may be ascribed to CPVT. Mutations of the RyR2 gene cause autosomal dominant CPVT, while mutations of the CASQ2 gene may cause an autosomal recessive or dominant form of CPVT. The steps of the molecular pathogenesis of CPVT are not entirely clear, but inappropriate "leakiness" of RyR2 channels is thought to play a role; the underlying mechanisms may involve an increase in the basal activity of the RyR2 channel, alterations in its phosphorylation status, a defective interaction of RyR2 with other molecules or ions, such as FKBP12.6, CASQ2, or Mg2+, or its abnormal activation by extra- or intraluminal Ca2+ ions. Beta-adrenergic antagonists have proven to be of value in prevention of arrhythmias in CPVT patients, but occasional treatment failures call for alternative measures. There is great interest at present for the development of novel antiarrhythmic drugs for CPVT, as the same approaches may be applied for treatment of more common forms of life-threatening arrhythmias, such as those arising during ischemia and heart failure. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disease so far related to mutations in the cardiac ryanodine receptor (RYR2) or the cardiac calsequestrin (CASQ2) genes. Because mutations in RYR2 or in CASQ2 are not retrieved in all CPVT cases, we searched for mutations in the physiological protein partners of RyR2 and CSQ2 in a large cohort of CPVT patients with no detected mutation in these two genes. Based on a candidate gene approach, we focused our investigations on triadin and junctin, two proteins that link RyR2 and CSQ2. Mutations in the triadin (TRDN) and in the junctin (ASPH) genes were searched in a cohort of 97 CPVT patients. We identified three mutations in triadin which cosegregated with the disease on a recessive mode of transmission in two families, but no mutation was found in junctin. Two TRDN mutations, a 4 bp deletion and a nonsense mutation, resulted in premature stop codons; the third mutation, a p.T59R missense mutation, was further studied. Expression of the p.T59R mutant in COS-7 cells resulted in intracellular retention and degradation of the mutant protein. This was confirmed after in vivo expression of the mutant triadin in triadin knock-out mice by viral transduction. In this work, we identified TRDN as a new gene responsible for an autosomal recessive form of CPVT. The mutations identified in the two families lead to the absence of the protein, thereby demonstrating the importance of triadin for the normal function of the cardiac calcium release complex in humans. OBJECTIVE: To identify mutations and variants in CASQ2 gene in 27 CPVT patients/family members. METHODS: Mutational analysis was performed with direct DNA sequence analysis. The frequency of an identified CASQ2 variant was determined using the Taqman genotyping assay. RESULTS: A novel heterozygous mutation, F189L, in CASQ2 gene was identified in one family with CPVT. This mutation occurred at the evolutionarily, highly conserved phenylalanine residue at codon 189, and was not present in 1400 control individuals. No other disease-causing mutations were identified in the CASQ2 gene. CONCLUSION: A novel mutation of F189L in the CASQ2 gene was identified.

What are the most frequent non-canonical sequence motifs at the donor and acceptor splice sites in vertebrates?

There are two major exceptions to the canonical GT-AG dinucleotides at donor and acceptor sites: the GG-AG splice site pairs, recognized through the typical U2 splicing machinery, and the AT-AC splice pairs recognized by the U12 splicing machinery.

[16267086, 11125105, 21079731, 20163699, 16306388, 11574683, 11058137, 17082203]

MOTIVATION: mRNA sequences and expressed sequence tags represent some of the most abundant experimental data for identifying genes and alternatively spliced products in metazoans. These transcript sequences are frequently studied by aligning them to a genomic sequence template. For existing programs, error-prone, polymorphic and cross-species data, as well as non-canonical splice sites, still present significant barriers to producing accurate, complete alignments. RESULTS: We took a novel approach to spliced alignment that meaningfully combined information from sequence similarity with that obtained from PSSM splice site models. Scoring systems were chosen to maximize their power of discrimination, and dynamic programming (DP) was employed to guarantee optimal solutions would be found. The resultant program, EXALIN, performed better than other popular tools tested under a wide range of conditions that included detection of micro-exons and human-mouse cross-species comparisons. For improved speed with only a marginal decrease in splice site prediction accuracy, EXALIN could perform limited DP guided by a result from BLASTN. AVAILABILITY: The source code, binaries, scripts, scoring matrices and splice site models for human, mouse, rice and Caenorhabditis elegans utilized in this study are posted at http://blast.wustl.edu/exalin. The software (scripts, source code and binaries) is copyrighted but free for all to use. MOTIVATION: The vast majority of introns in protein-coding genes of higher eukaryotes have a GT dinucleotide at their 5'-terminus and an AG dinucleotide at their 3' end. About 1-2% of introns are non-canonical, with the most abundant subtype of non-canonical introns being characterized by GC and AG dinucleotides at their 5'- and 3'-termini, respectively. Most current gene prediction software, whether based on ab initio or spliced alignment approaches, does not include explicit models for non-canonical introns or may exclude their prediction altogether. With present amounts of genome and transcript data, it is now possible to apply statistical methodology to non-canonical splice site prediction. We pursued one such approach and describe the training and implementation of GC-donor splice site models for Arabidopsis and rice, with the goal of exploring whether specific modeling of non-canonical introns can enhance gene structure prediction accuracy. RESULTS: Our results indicate that the incorporation of non-canonical splice site models yields dramatic improvements in annotating genes containing GC-AG and AT-AC non-canonical introns. Comparison of models shows differences between monocot and dicot species, but also suggests GC intron-specific biases independent of taxonomic clade. We also present evidence that GC-AG introns occur preferentially in genes with atypically high exon counts. AVAILABILITY: Source code for the updated versions of GeneSeqer and SplicePredictor (distributed with the GeneSeqer code) isavailable at http://bioinformatics.iastate.edu/bioinformatics2go/gs/download.html. Web servers for Arabidopsis, rice and other plant species are accessible at http://www.plantgdb.org/PlantGDB-cgi/GeneSeqer/AtGDBgs.cgi, http://www.plantgdb.org/PlantGDB-cgi/GeneSeqer/OsGDBgs.cgi and http://www.plantgdb.org/PlantGDB-cgi/GeneSeqer/PlantGDBgs.cgi, respectively. A SplicePredictor web server is available at http://bioinformatics.iastate.edu/cgi-bin/sp.cgi. Software to generate training data and parameterizations for Bayesian splice site models is available at http://gremlin1.gdcb.iastate.edu/~volker/SB05B/BSSM4GSQ/ U12-dependent introns are found in small numbers in most eukaryotic genomes, but their scarcity makes accurate characterisation of their properties challenging. A computational search for U12-dependent introns was performed using the draft version of the human genome sequence. Human expressed sequences confirmed 404 U12-dependent introns within the human genome, a 6-fold increase over the total number of non-redundant U12-dependent introns previously identified in all genomes. Although most of these introns had AT-AC or GT-AG terminal dinucleotides, small numbers of introns with a surprising diversity of termini were found, suggesting that many of the non-canonical introns found in the human genome may be variants of U12-dependent introns and, thus, spliced by the minor spliceosome. Comparisons with U2-dependent introns revealed that the U12-dependent intron set lacks the 'short intron' peak characteristic of U2-dependent introns. Analysis of this U12-dependent intron set confirmed reports of a biased distribution of U12-dependent introns in the genome and allowed the identification of several alternative splicing events as well as a surprising number of apparent splicing errors. This new larger reference set of U12-dependent introns will serve as a resource for future studies of both the properties and evolution of the U12 spliceosome. A set of 43 337 splice junction pairs was extracted from mammalian GenBank annotated genes. Expressed sequence tag (EST) sequences support 22 489 of them. Of these, 98.71% contain canonical dinucleotides GT and AG for donor and acceptor sites, respectively; 0.56% hold non-canonical GC-AG splice site pairs; and the remaining 0.73% occurs in a lot of small groups (with a maximum size of 0.05%). Studying these groups we observe that many of them contain splicing dinucleotides shifted from the annotated splice junction by one position. After close examination of such cases we present a new classification consisting of only eight observed types of splice site pairs (out of 256 a priori possible combinations). EST alignments allow us to verify the exonic part of the splice sites, but many non-canonical cases may be due to intron sequencing errors. This idea is given substantial support when we compare the sequences of human genes having non-canonical splice sites deposited in GenBank by high throughput genome sequencing projects (HTG). A high proportion (156 out of 171) of the human non-canonical and EST-supported splice site sequences had a clear match in the human HTG. They can be classified after corrections as: 79 GC-AG pairs (of which one was an error that corrected to GC-AG), 61 errors that were corrected to GT-AG canonical pairs, six AT-AC pairs (of which two were errors that corrected to AT-AC), one case was produced from non-existent intron, seven cases were found in HTG that were deposited to GenBank and finally there were only two cases left of supported non-canonical splice sites. If we assume that approximately the same situation is true for the whole set of annotated mammalian non-canonical splice sites, then the 99.24% of splice site pairs should be GT-AG, 0.69% GC-AG, 0.05% AT-AC and finally only 0.02% could consist of other types of non-canonical splice sites. We analyze several characteristics of EST-verified splice sites and build weight matrices for the major groups, which can be incorporated into gene prediction programs. We also present a set of EST-verified canonical splice sites larger by two orders of magnitude than the current one (22 199 entries versus approximately 600) and finally, a set of 290 EST-supported non-canonical splice sites. Both sets should be significant for future investigations of the splicing mechanism. U12-type introns are spliced by the U12-dependent spliceosome and are present in the genomes of many higher eukaryotic lineages including plants, chordates and some invertebrates. However, due to their relatively recent discovery and a systematic bias against recognition of non-canonical splice sites in general, the introns defined by U12-type splice sites are under-represented in genome annotations. Such under-representation compounds the already difficult problem of determining gene structures. It also impedes attempts to study these introns genome-wide or phylum-wide. The resource described here, the U12 Intron Database (U12DB), aims to catalog the U12-type introns of completely sequenced eukaryotic genomes in a framework that groups orthologous introns with each other. This will aid further investigations into the evolution and mechanism of U12-dependent splicing as well as assist ongoing genome annotation efforts. Public access to the U12DB is available at http://genome.imim.es/cgi-bin/u12db/u12db.cgi.

What does isradipine do to L-type channels?

Isradipine antagonizes/blocks the L-type channels.

[18996099, 17311846, 21487241, 17884683, 17218348, 21515375, 7978480, 20816785, 11285265, 9398449, 11283860, 21925266, 8178970, 9585150, 19385055]

Activation of large conductance Ca(2+)-activated potassium (BK) channels hastens action potential repolarisation and generates the fast afterhyperpolarisation in hippocampal pyramidal neurons. A rapid coupling of Ca(2+) entry with BK channel activation is necessary for this to occur, which might result from an identified coupling of Ca(2+) entry through N-type Ca(2+) channels to BK channel activation. This selective coupling was extremely rapid and resistant to intracellular BAPTA, suggesting that the two channel types are close. Using reciprocal co-immunoprecipitation, we found that N-type channels were more abundantly associated with BK channels than L-type channels (Ca(V)1.2) in rat brain. Expression of only the pore-forming alpha-subunits of the N-type (Ca(V)2.2) and BK (Slo(27)) channels in a non-neuronal cell-line gave robust macroscopic currents and reproduced the interaction. Co-expression of Ca(V)2.2/Ca(V)beta(3) subunits with Slo(27) channels revealed rapid functional coupling. By contrast, extremely rare examples of rapid functional coupling were observed with co-expression of Ca(V)1.2/Ca(V)beta(3) and Slo(27) channels. Action potential repolarisation in hippocampal pyramidal neurons was slowed by the N-type channel blocker omega-conotoxin GVIA, but not by the L-type channel blocker isradipine. These data showed that selective functional coupling between N-type Ca(2+) and BK channels provided rapid activation of BK channels in central neurons. Parkinson's disease is a common neurodegenerative disorder of unknown cause. There is no cure or proven strategy for slowing the progression of the disease. Although there are signs of pathology in many brain regions, the core symptoms of Parkinson's disease are attributable to the selective degeneration of dopaminergic neurons in the substantia nigra pars compacta. A potential clue to the vulnerability of these neurons is their increasing reliance on Ca(2+) channels to maintain autonomous activity with age. This reliance could pose a sustained metabolic stress on mitochondria, accelerating cellular ageing and death. The Ca(2+) channels underlying autonomous activity in dopaminergic neurons are closely related to the L-type channels found in the heart and smooth muscle. Systemic administration of isradipine, a dihydropyridine blocker of L-type channels, forces dopaminergic neurons in rodents to revert to a juvenile, Ca(2+)-independent mechanism to generate autonomous activity. More importantly, reversion confers protection against toxins that produce experimental parkinsonism, pointing to a potential neuroprotective strategy for Parkinson's disease with a drug class that has been used safely in human beings for decades. These studies also suggest that, although genetic and environmental factors can hasten its onset, Parkinson's disease stems from a distinctive neuronal design common to all human beings, making its appearance simply a matter of time. This study examines the molecular basis for the T-type and L-type Ca(2+) currents in canine Purkinje cells. The I(CaT) in Purkinje cells was completely suppressed by 200 nM kurtoxin, a specific blocker of both Ca(v)3.1 and Ca(v)3.2 channels. Since only Ca(v)3.2 mRNA is expressed at high levels in Purkinje fibres, being approximately 100-fold more abundant than either Ca(v)3.1 or Ca(v)3.3 mRNAs, it is concluded that the Ca(v)3.2 gene encodes the bulk of the T-type Ca(2+) channels in canine Purkinje cells. This conclusion is consistent with the sensitivity of the current to blockade by Ni(2+) ions (K(D) = 32 microM). For L-type channels, Ca(v)1.2 mRNA was most abundant in Purkinje fibres but a significant level of Ca(v)1.3 mRNA expression was also found. A comparison of the sensitivity to blockade by isradipine of the L-type currents in Purkinje cells and ventricular epicardial myocytes, which only express Ca(v)1.2, suggests that the Ca(v)1.3 channels make, at most, a minor contribution to the L-type current in canine Purkinje cells. The motor symptoms of Parkinson's disease (PD) are due to the progressive loss of dopamine (DA) neurons in substantia nigra pars compacta (SNc). Nothing is known to slow the progression of the disease, making the identification of potential neuroprotective agents of great clinical importance. Previous studies using the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD have shown that antagonism of L-type Ca2+ channels protects SNc DA neurons. However, this was not true in a 6-hydroxydopamine (6-OHDA) model. One potential explanation for this discrepancy is that protection in the 6-OHDA model requires greater antagonism of Cav1.3 L-type Ca2+ channels thought to underlie vulnerability and this was not achievable with the low affinity dihydropyridine (DHP) antagonist used. To test this hypothesis, the DHP with the highest affinity for Cav1.3L-type channels-isradipine-was systemically administered and then the DA toxin 6-OHDA injected intrastriatally. Twenty-five days later, neuroprotection and plasma concentration of isradipine were determined. This analysis revealed that isradipine produced a dose-dependent sparing of DA fibers and cell bodies at concentrations achievable in humans, suggesting that isradipine is a potentially viable neuroprotective agent for PD. In cochlea inner hair cells (IHCs), L-type Ca(2+) channels (LTCCs) formed by alpha1D subunits (D-LTCCs) possess biophysical and pharmacological properties distinct from those of alpha1C containing C-LTCCs. We investigated to which extent these differences are determined by alpha1D itself by analyzing the biophysical and pharmacological properties of cloned human alpha1D splice variants in tsA-201 cells. Variant alpha1D(8A,) containing exon 8A sequence in repeat I, yielded alpha1D protein and L-type currents, whereas no intact protein and currents were observed after expression with exon 8B. In whole cell patch-clamp recordings (charge carrier 15-20 mm Ba(2+)), alpha1D(8A) - mediated currents activated at more negative voltages (activation threshold, -45.7 versus -31.5 mV, p < 0.05) and more rapidly (tau(act) for maximal inward currents 0.8 versus 2.3 ms; p < 0.05) than currents mediated by rabbit alpha1C. Inactivation during depolarizing pulses was slower than for alpha1C (current inactivation after 5-s depolarizations by 90 versus 99%, p < 0.05) but faster than for LTCCs in IHCs. The sensitivity for the dihydropyridine (DHP) L-type channel blocker isradipine was 8.5-fold lower than for alpha1C. Radioligand binding experiments revealed that this was not due to a lower affinity for the DHP binding pocket, suggesting that differences in the voltage-dependence of DHP block account for decreased sensitivity of D-LTCCs. Our experiments show that alpha1D(8A) subunits can form slowly inactivating LTCCs activating at more negative voltages than alpha1C. These properties should allow D-LTCCs to control physiological processes, such as diastolic depolarization in sinoatrial node cells, neurotransmitter release in IHCs and neuronal excitability. Following chronic liver injury, hepatic stellate cells (HSCs) transdifferentiate into myofibroblast-like cells, which develop contractile properties and contribute to increased resistance to blood flow. We investigated whether this phenotypic activation includes changes in the expression of L-type voltage-operated Ca2+ channels (VOCC), which mediate Ca2+ influx and regulate cell contraction in vascular cell types. Rat HSCs were studied in the quiescent phenotype and after their activation in vitro (cultured on plastic for 14 days) and in vivo (isolated from rats with CCl(4)-induced cirrhosis). Patch-clamp studies showed Ca2+ currents through L-type VOCC in HSCs activated both in vitro and in vivo, whereas no currents were detected in quiescent HSCs. Moreover, binding studies with (3)H-isradipine, a specific L-type VOCC antagonist, showed a large number of binding sites in activated HSCs, while no specific binding was found in quiescent HSCs. Finally, messenger RNA (mRNA) encoding L-type VOCC was not detected in quiescent HSCs as assessed by reverse transcription-polymerase chain reaction (RT-PCR) and Northern blot analysis, whereas it was present in activated HSCs. Stimulation of L-type VOCC with KCl resulted in a marked increase in [Ca2+](i) followed by cell contraction in HSCs activated both in vitro and in vivo, whereas no effects were observed in quiescent HSCs. We conclude that the activation of HSCs is associated with up-regulation of L-type VOCC that mediate Ca2+ influx and cell contraction. These results may be relevant to the pathogenesis of portal hypertension. Alzheimer's disease is the most devastating neurodegenerative disorder in the elderly, yet treatment options are severely limited. The drug development effort to modify Alzheimer's disease pathology by intervention at beta amyloid production sites has been largely ineffective or inconclusive. The greatest challenge has been to identify and define downstream mechanisms reliably predictive of clinical symptoms. Beta amyloid accumulation leads to dysregulation of intracellular calcium by plasma membrane L-type calcium channels located on neuronal somatodendrites and axons in the hippocampus and cortex. Paradoxically, L-type calcium channel subtype Ca(v)1.2 also promotes synaptic plasticity and spatial memory. Increased intracellular calcium modulates amyloid precursor protein processing and affects multiple downstream pathways including increased hyperphosphorylated tau and suppression of autophagy. Isradipine is a Federal Drug Administration-approved dihydropyridine calcium channel blocker that binds selectively to Ca(v)1.2 in the hippocampus. Our studies have shown that isradipine in vitro attenuates beta amyloid oligomer toxicity by suppressing calcium influx into cytoplasm and by suppressing Ca(v)1.2 expression. We have previously shown that administration of isradipine to triple transgenic animal model for Alzheimer's disease was well-tolerated. Our results further suggest that isradipine became bioavailable, lowered tau burden, and improved autophagy function in the brain. A better understanding of brain pharmacokinetics of calcium channel blockers will be critical for designing new experiments with appropriate drug doses in any future clinical trials for Alzheimer's disease. This review highlights the importance of Ca(v)1.2 channel overexpression, the accumulation of hyperphosphorylated tau and suppression of autophagy in Alzheimer's disease and modulation of this pathway by isradipine. Previous studies have shown that 17 beta-estradiol (beta-E2) has a direct acute inhibitory effect on vascular smooth muscle (VSM) contraction. To investigate the mechanisms underlying this phenomenon, we utilized whole cell patch-clamping techniques to study effects of beta-E2 on voltage-dependent Ca2+ channels in cultured VSM cells (VSMC). T- and L-type Ca2+ currents were characterized with ramp and pulse protocols in A7r5 cultured VSMC. T-type current, inactivated in < 100 ms, was reduced by Ba2+ and was comparatively little affected by isradipine. L-type current required higher voltages to activate, inactivated slowly, was greatly increased by Ba2+, and could be completely inhibited by 5 microM isradipine. beta-E2 (10 microM) significantly reduced peak L-type Ba2+ current and T-type Ca2+ current within 1-2 min, whereas alpha E2 (a hormonally inactive isomer of estradiol) caused significantly less reduction in both types of current. Vehicle (0.1% ethanol) had no significant effect on either current. The inhibitory effect of beta-E2 on voltage-dependent Ca2+ currents may contribute to previously demonstrated beta-E2 attenuation of VSM contraction. We have demonstrated that both high-K+ and electrical stimulation of the vagus nerves release endogenous glutamate from the vascularly-perfused rat stomach in a calcium-dependent manner. In the present study, we examined properties of calcium channel subtypes mediating endogenous glutamate release from the stomach. Application of 50 mM KCl elicited a release of glutamate, and this release was abolished in calcium-free medium. The release of glutamate was significantly inhibited by both omega-agatoxin IVA, a P/Q-type calcium channel antagonist, and isradipine, an L type calcium channel antagonist. Omega-conotoxin GVIA, an N type calcium channel antagonist and flunarizine, a nonselective T-type calcium channel antagonist were without effect. In contrast to this case of glutamate, omega-conotoxin GVIA induced a marked inhibition in the release of gastric noradrenaline. The combined treatment with omega-agatoxin IVA plus isradipine produced a marked synergistic inhibition of the glutamate release. This inhibition was, however, much less than that by cadmium. The present results suggest that P/Q and L type calcium channels coexist to regulate the release of gastric glutamate. Furthermore, it is possible that unidentified calcium channels other than P/Q and L type channels are also involved in the release of glutamate in the stomach.

Why does cranberry juice help combat urinary tract infections?

Cranberry products affect the surface properties, such as fimbriae and lipopolysaccharides, and adhesion of fimbriated and nonfimbriated E. coli.

[24304610, 21480803, 23440506, 22499815, 19257836, 21688109, 19636526, 20495471, 19284180, 9110682, 19921981]

Flavonoids, present in high levels in cranberries, are potent bioactives known for their health-promoting benefits, but cranberry beverages (CB) are not typically recommended as part of a healthy diet. We examine the association between CB consumption with macronutrient intake and weight status. Data for US adults (≥19 years, n = 10,891) were taken from the National Health and Nutrition Examination Survey (NHANES) Survey 2005-2008. Total CB consumption was measured over two non-consecutive 24-h dietary recalls. Linear and logistic regression models adjusting for important covariates were used to examine predicted differences between CB consumers and non-consumers on macronutrient and anthropometric outcomes. Results are weighted to be nationally representative. CB consumers (n = 581) were older (>50 year) non-Hispanic black females. They consumed an average 221 mL (7.5 oz) CB per day. In fully adjusted models CB consumers (vs. non-consumers) had higher carbohydrates and total sugars and lower percent energy from protein and total fat (all p < 0.001), but no difference in total energy. A significantly higher proportion of CB consumers were predicted to be normal weight (BMI < 25 kg/m2; p = 0.001) and had to have lower waist circumferences (p = 0.001). Although there was not a significant trend across level of CB intake, low and middle level CB consumers compared to non-consumers were more likely to be normal weight (p < 0.001) and less likely to be overweight/obese (BMI ≥ 25 kg/m2, p < 0.001). Despite having slightly higher daily macronutrient intakes, CB consumers have more desirable anthropometric measures compared to non-consumers. Question Plusieurs enfants de ma clinique se rétablissent d’une infection des voies urinaires (IVU). La mère de l’un d’eux m’a demandé si je recommandais le jus de canneberge pour prévenir de futurs épisodes d’IVU. On lui avait recommandé d’en boire lorsqu’elle a souffert d’une IVU il y a quelques mois. Réponse Il a été démontré que le jus de canneberge était efficace pour prévenir l’adhésion de bactéries comme l’Escherichia coli à l’épithélium de la vessie. Les données scientifiques actuelles appuient l’utilisation du jus de canneberge pour la prévention des IVU chez les femmes adultes, mais il n’en existe pas pour le moment sur la prévention des IVU chez l’enfant. Si le jus de canneberge est très sécuritaire pour la plupart des enfants, son acidité fait que son goût est moins apprécié des enfants. Il reste aussi à déterminer la quantité de jus de canneberge nécessaire pour prévenir les IVU chez les enfants. Proanthocyanidin is commonly used for inhibiting urinary tract infection (UTI) of sensitive strains of Escherichia coli. The aim of this study was to investigate the effect of proanthocyanidin on adherence of uropathogenic multi-drug resistant E. coli to uroepithelial cells, which has not yet been investigated so far. Extracts of the purified proanthocyanidin were prepared from dried cranberry juice. Purity and structural assignment of proanthocyanidin was assessed using high performance liquid chromatography and (13)C nuclear magnetic resonance spectroscopy, respectively. Subsequently, its affect on multi-drug resistant bacteria as well as quantification of anti-adherence bioactivity on human vaginal and bladder epithelial cells was appraised. Inhibition of adherence to an extent of about 70% with multi-drug resistant E. coli strains was observed on uroepithelial cell. The anti-adherence bioactivity of the proanthocyanidin was detected at concentrations of 10-50 µg/ml with significant bacteriuria. Probable proanthocyanidin through A-type linkages either combines to P-fimbriae of bacterial cells or modifies the structural entity of P-fimbriae and inhibits bacterial adherence to uroepithelial cells. The proanthocyanidin exhibited anti-adherence property with multi-drug resistant strains of uropathogenic P-fimbriated E. coli with in vitro study. Hence proanthocyanidin may be considered as an inhibitory agent for multi-drug resistant strains of E. coli adherence to uroepithelial cells. Cranberry (Vaccinium macrocarpon) has been used for decades to prevent urinary tract infections (UTIs) that are among the most common bacterial infections in women. As to the traditional use of cranberry and its A-type proanthocyanidins' ability to inhibit adherence of the bacterial P fimbriae in a dose-dependent manner, clinical trials have been conducted on different subpopulations. A Cochrane meta-analysis in 244 females with symptomatic UTI suggests that the effect was more pronounced in women with recurrent UTIs than elderly males and females or people requiring catheterization. A first head-to-head trial in older females has been published comparing effectiveness of a low-dose antibiotic versus cranberry in which investigators suggest that cranberry products may have a role in older females with recurrent UTI. Still with regard to antibiotic treatment in women, a recently published study investigated also the potential cranberry juice interaction with beta-lactam antibiotics supporting the hypothesis that cranberry juice in usual quantities as prophylaxis for UTI is not likely to alter the pharmacokinetics of these oral antibiotics. In addition, the effects of cranberry in pregnant female patients have been investigated. A first pilot trial has been published in which, while a possible protective effect was shown, more than one third of the females withdrew mainly for gastrointestinal upset. CONTEXT: Cranberry juice has long been recognized in folk medicine as a therapeutic agent, mainly in urinary tract infections. Its proposed mechanism of action is antiadhesion of bacteria. OBJECTIVE: Investigation of the potential antiadhesion effect of nondialyzed material of cranberry (NDM) via its influence on secretion, gene expression, and promoter activity of the fructosyltransferase (FTF), which is among the extracellular enzymes associated with dental biofilm formation and pathogenesis of oral bacteria. MAIN OUTCOME MEASURES: Secretion of FTF from Streptococcus mutans, in the presence of NDM, was measured by immunoblotting and confocal scanning laser microscopy. Its influence on ftf gene expression was determined by reverse transcription followed by real-time RT-PCR. The luciferase assay was used to detect bioluminescence expressed by the ftf promoter activity of bacteria exposed to NDM. RESULTS: NDM at concentrations between 0.2/mL and 1mg/mL significantly (P<.05) decreased secretion of extracellular FTF, as well as down-regulated ftf expression in a dose-dependent manner. NDM also markedly reduced the luciferase activity under the ftf promoter. Most research suggests that ingestion of cranberry juice may be useful in preventing urinary tract infections. This pilot study examines the effect of drinking moderate amounts of commercially available cranberry juice cocktail on urinary pH in older, institutionalized adults. The results of the study have implications for home care nurses who have similar patients in their case loads.

In which diseases have electronic patient diaries been applied ?

Parkinson's disease COPD Food hypersensitivity Niacin induced flushing Hemophilia Heartburn Headache

[14728392, 19999626, 20841643, 8904620, 19226411, 19301936, 10594395, 22949085]

Attention needs to be given to how patients can capitalize on the benefits of Personal Digital Assistant technology. The specific aims of this pilot study are to compare the efficacy of diabetic patients documenting their health maintenance data (i.e. blood glucose levels, meal intake, and exercise) using an electronic patient diary (ED) versus a traditional pen and paper (PD) diary; and determine participants' satisfaction with each diary approach. Several studies have shown that the current prevalence of food allergy in Western Europe is about 4% and will further increase. Because of missing therapeutic alternatives, food allergy patients are required to identify individual allergens in the daily food by carefully reading the product's ingredient lists. Experiences with other chronic diseases show that a combination of telemedicine and Disease Management (DM) could have a positive impact on medical outcome and health related costs. A new concept of telemedicine support for allergy patients and allergists has been elaborated within the Luxembourgian MENSSANA project. Instead of measuring physiological parameters, a Smartphone based Personal Allergy Assistant (PAA) allows patients to keep an electronic patient diary by scanning the barcode of the consumed food products. For diagnostic purpose, the diary is regularly transmitted to the allergist's electronic patient record. To further support the individual diet management, the PAA gives a warning before consumption of allergenic food. Computer readable food ingredient lists are required for the PAA diet management. To collect this kind of information, a dedicated web-based "virtual community" of food consumers and producers (www.wikifood.eu) has been established. This volunteer network complements an independent product database. Up to now, more than 13.000 food descriptions are public available within wikifood.eu. This research paper examines the challenges in the development and adoption of an electronic patient diary within the Pathways Home for Respiratory Illness Project. This project supported community-based patients suffering from chronic obstructive pulmonary disease (COPD) to achieve increased levels of self-management and self-efficacy using electronic-monitoring techniques and mentoring by community health nurses. Participants had the option of voluntarily adopting an electronic patient diary to support their self-monitoring, which provided patients, nurses and clinicians with access to symptom and psycho-social data. This aimed to improve the identification, comprehension and initiation of early action in relation to alterations in their conditions. The paper presents data on technology adoption, electronic diary usage and, self-reported data quality, as well as examining the impact of the technology on hospitalisations (frequency and duration). The participants who chose to use the online patient diary continued their involvement with the project for the entire trial period (85% vs 54% completion). Participants were more likely to maintain use of the online patient diary than the paper diary. Both the groups experienced a positive improvement in their self-efficacy to self-manage their condition scores. The data highlight the problems implicit in some of the assumptions underpinning existing information systems models, especially in evaluating impact and the end-points presumed to be relevant in systems development life cycles. On-demand or prophylactic home-treatment is currently the treatment of choice for haemophilia patients. To allow physicians to monitor the amount of factor concentrates administered, the patients document each factor injection in a paper-diary. Nevertheless, because of the fact that most patients visit their physicians only two to four times a year, there could be considerable delay in detecting medication problems. The aim of this pilot study was to assess whether an electronic documentation tool could successfully replace traditional paper-diaries for haemophilia A patients and enable the physician to have a timely overview of the patient's treatment. An electronic, hand-held documentation tool, Haemoassist, was developed. In this study, patients using prophylaxis and on-demand therapies documented their factor consumption both electronically and on paper-diaries. Documentations were compared and descriptively evaluated. Patients also completed a survey to evaluate the feasibility and gather their opinions on the Haemoassist system. Ten patients from two haemophilia treatment centres in Germany submitted a total of 548 records via hand-held device during the observation period, from March 2006 to February 2007. Comparison of electronic and paper-based records showed differing responses among patients with some patients entering more electronic and some others more paper-based documentations. In the questionnaires on feasibility and usefulness of Haemoassist, three patients preferred the electronic tool, two patients wanted to continue using paper-based diaries, and one had no preference. The study shows that an electronic documentation system is feasible for haemophilia patients and provides the physician with the opportunity to more closely monitor patients. However, not all patients seem to be qualified for using an electronic tool, and the tool has to run reliably without major errors for ensuring reliability and acceptability. In the future, Haemoassist might support quality assurance in haemophilia treatment and improve guidance in the home-care setting. BACKGROUND AND OBJECTIVE: A common adverse effect of niacin therapy is flushing, manifested by cutaneous warmth, redness, itching and/or tingling. The Flushing ASsessment Tool (FAST) was developed to assess flushing symptoms and their impact on patients receiving niacin therapy. This study evaluated the reliability, validity and responsiveness of the FAST. The minimal important difference (MID) of the FAST was also examined. METHODS: This was a prospective, randomized, double-blind, placebo-controlled, parallel-group 8-week study conducted to evaluate the psychometric characteristics of the FAST. The instrument is administered daily using an electronic patient diary. The study was conducted at 41 clinical sites in the US. 276 patients with dyslipidaemia were randomized to treatment and were at least 18 years of age, with fasting laboratory values of low-density lipoprotein cholesterol (LDL-C) <250 mg/dL and one of the following: high-density lipoprotein cholesterol (HDL-C) <40 mg/dL for males or <50 mg/dL for females; or triglycerides (TG) > or = 150 and < or = 400 mg/dL; or LDL-C > or = 70 mg/dL for patients with a history of coronary heart disease (CHD) or CHD risk equivalents, or > or = 100 mg/dL for subjects with two risk factors, or > or = 160 mg/dL for subjects with 0-1 risk factors. Patients were randomized (1 : 1 : 1) to receive niacin extended-release (NER) 500 mg/day in week 1, 1000 mg/day in week 2 and 2000 mg/day in weeks 3-6/aspirin (acetylsalicylic acid [ASA]), NER/ASA placebo, or NER placebo/ASA placebo. RESULTS: FAST test-retest reliability in stable patients during the first 2 weeks was demonstrated for overall flushing severity using patient and physician overall treatment effect (OTE) ratings (intraclass correlation coefficients of >0.7 for mean overall and individual flushing severity scores). Over the 6-week treatment period, FAST scores demonstrated significant correlations with individual symptoms, impact on daily activities and sleep, and dissatisfaction related to flushing (p < 0.01). Changes in FAST scores were associated with treatment satisfaction (p < 0.01) and patient- and physician-rated OTE (p < 0.01). Using patient-rated OTE, the mean maximum flushing severity scores improved 1.85 points in responders and only 0.18 points in non-responders (p < 0.001); responders were defined by improved patient- or physician-rated OTE. Among patients with flushing, mean maximum overall flushing scores differed between patients who subsequently discontinued due to flushing (7.9 points) and those who did not discontinue (4.7 points; p < 0.001). The probable range in this study for a detectable change in flushing symptoms (MID) was 0.29-0.38 points for mean flushing severity and 0.66-0.86 points for maximum flushing severity. CONCLUSION: The FAST exhibited test-retest reliability, good evidence of construct validity, and, overall, flushing severity was responsive to change over time. The FAST is a reliable and valid instrument for assessing the impact of niacin-induced flushing in patients with dyslipidaemia. Current clinical methods for the assessment of Parkinson's disease suffer from inconvenience, infrequency and subjectivity. WiiPD is an approach for the objective home based assessment of Parkinson's disease which utilizes the intuitive and sensor rich Nintendo Wii Remote. Combined with an electronic patient diary, a suite of mini-games, a metric analyzer, and a visualization engine, we propose that this system can complement existing clinical practice by providing objective metrics gathered frequently over extended periods of time. In this paper we detail the approach and introduce a series of metrics deemed capable of quantifying the severity of tremor and bradykinesia in those with Parkinson's disease. The system has been tested on a 71 year old participant with Parkinson's disease over a period of 15 days, a 72 year old control user without Parkinson's disease, and a group of 8 young adults. Results indicate a clear correlation between patient self rating scores of tremor severity and metric values obtained, in addition to clear differences in metrics obtained from each user group. These results suggest that this approach is capable of indicating the presence and severity of the motor symptoms of Parkinson's disease that affect arm motor control.

Which type of myeloma is ixazomib being evaluated for?

The disease focus for the irreversible epoxyketone proteasome inhibitor ixazomib is multiple myeloma.

[24292417, 24920586, 25302026, 24712303, 25456369, 24471924, 25268212, 25935605, 24904120, 24486586, 24578203]

(18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT) are useful imaging modalities for evaluating tumor progression and treatment responses in genetically engineered mouse models of solid human cancers, but the potential of integrated FDG-PET/CT for assessing tumor development and new interventions in transgenic mouse models of human blood cancers such as multiple myeloma (MM) has not been demonstrated. Here we use BALB/c mice that contain the newly developed iMyc(ΔEμ) gene insertion and the widely expressed H2-L(d)-IL6 transgene to demonstrate that FDG-PET/CT affords an excellent research tool for assessing interleukin-6- and MYC-driven plasma cell tumor (PCT) development in a serial, reproducible and stage- and lesion-specific manner. We also show that FDG-PET/CT permits determination of objective drug responses in PCT-bearing mice treated with the investigational proteasome inhibitor ixazomib (MLN2238), the biologically active form of ixazomib citrate (MLN9708), that is currently in phase 3 clinical trials in MM. Overall survival of 5 of 6 ixazomib-treated mice doubled compared with mice left untreated. One outlier mouse presented with primary refractory disease. Our findings demonstrate the utility of FDG-PET/CT for preclinical MM research and suggest that this method will play an important role in the design and testing of new approaches to treat myeloma. Ixazomib is the first investigational oral proteasome inhibitor to be studied clinically. In this phase 1 trial, 60 patients with relapsed/refractory multiple myeloma (median of 4 prior lines of therapy; bortezomib, lenalidomide, thalidomide, and carfilzomib/marizomib in 88%, 88%, 62%, and 5%, respectively) received single-agent ixazomib 0.24 to 2.23 mg/m(2) (days 1, 4, 8, 11; 21-day cycles). Two dose-limiting toxicities (grade 3 rash; grade 4 thrombocytopenia) occurred at 2.23 mg/m(2). The maximum tolerated dose was 2.0 mg/m(2), which 40 patients received in 4 expansion cohorts. Patients received a median of 4 cycles (range, 1-39); 18% received ≥12 cycles. Eighty-eight percent had drug-related adverse events, including nausea (42%), thrombocytopenia (42%), fatigue (40%), and rash (40%); drug-related grade ≥3 events included thrombocytopenia (37%) and neutropenia (17%). Grade 1/2 drug-related peripheral neuropathy occurred in 12% (no grade ≥3). Two patients died on the study (both considered unrelated to treatment). The terminal half-life of ixazomib was 3.3 to 7.4 days; plasma exposure increased proportionally with dose (0.48-2.23 mg/m(2)). Among 55 response-evaluable patients, 15% achieved partial response or better (76% stable disease or better). These findings have informed the subsequent clinical development of ixazomib in multiple myeloma. This trial was registered at www.clinicaltrials.gov as #NCT00932698. Proteasome inhibition represents one of the more important therapeutic targets in the treatment of multiple myeloma (MM), since by suppressing nuclear factor-κB activity, which promotes myelomagenesis, it makes plasma cells susceptible to proapoptotic signals. Bortezomib, the first proteasome inhibitor approved for MM therapy, has been shown to increase response rate and improve outcome in patients with relapsed/refractory disease and in the frontline setting, particularly when combined with immunomodulatory drugs and alkylating agents. Among second-generation proteasome inhibitors, ixazomib (MLN9708) is the first oral compound to be evaluated for the treatment of MM. Ixazomib has shown improved pharmacokinetic and pharmacodynamic parameters compared with bortezomib, in addition to similar efficacy in the control of myeloma growth and prevention of bone loss. Ixazomib was found to overcome bortezomib resistance and to trigger synergistic antimyeloma activity with dexamethasone, lenalidomide, and histone deacetylase inhibitors. Phase I/II studies using ixazomib weekly or twice weekly in relapsed/refractory MM patients suggested antitumor activity of the single agent, but more promising results have been obtained with the combination of ixazomib, lenalidomide, and dexamethasone in newly diagnosed MM. Ixazomib has also been used in systemic amyloidosis as a single agent, showing important activity in this difficult-to-treat plasma-cell dyscrasia. More frequent side effects observed during administration of ixazomib were thrombocytopenia, nausea, vomiting, diarrhea, fatigue, and rash, whereas severe peripheral neuropathy was rare. Here, we review the chemical characteristics of ixazomib, as well as its mechanism of action and results from preclinical and clinical trials. Inhibition of proteasome, a proteolytic complex responsible for the degradation of ubiquitinated proteins, has emerged as a powerful strategy for treatment of multiple myeloma (MM), a plasma cell malignancy. First-in-class agent, bortezomib, has demonstrated great positive therapeutic efficacy in MM, both in pre-clinical and in clinical studies. However, despite its high efficiency, a large proportion of patients do not achieve sufficient clinical response. Therefore, the development of a second-generation of proteasome inhibitors (PIs) with improved pharmacological properties was needed. Recently, several of these new agents have been introduced into clinics including carfilzomib, marizomib and ixazomib. Further, new orally administered second-generation PI oprozomib is being investigated. This review provides an overview of main mechanisms of action of PIs in MM, focusing on the ongoing development and progress of novel anti-proteasome therapeutics. BACKGROUND: The combination of bortezomib, lenalidomide, and dexamethasone is a highly effective therapy for newly diagnosed multiple myeloma. Ixazomib is an investigational, oral, proteasome inhibitor with promising anti-myeloma effects and low rates of peripheral neuropathy. In a phase 1/2 trial we aimed to assess the safety, tolerability, and activity of ixazomib in combination with lenalidomide and dexamethasone in newly diagnosed multiple myeloma. METHODS: We enrolled patients newly diagnosed with multiple myeloma aged 18 years or older with measurable disease, Eastern Cooperative Oncology Group performance status 0-2, and no grade 2 or higher peripheral neuropathy, and treated them with oral ixazomib (days 1, 8, 15) plus lenalidomide 25 mg (days 1-21) and dexamethasone 40 mg (days 1, 8, 15, 22) for up to 12 28-day cycles, followed by maintenance therapy with ixazomib alone. In phase 1, we gave patients escalating doses of ixazomib (1·68-3·95 mg/m(2)) to establish the recommended dose for phase 2. The primary endpoints were maximum tolerated dose for phase 1, and the rate of very good partial response or better for phase 2. Safety analyses were done in all patients who received at least one dose of study drug; efficacy analyses were done in all patients who received at least one dose of study drug at the phase 2 dose, had measurable disease at baseline, and had at least one post-baseline response assessment. This study is registered at ClinicalTrials.gov, number NCT01217957. FINDINGS: Between Nov 22, 2010, and Feb 28, 2012, we enrolled 65 patients (15 to phase 1 and 50 to phase 2). Four dose-limiting toxic events were noted in phase 1: one at a dose of ixazomib of 2·97 mg/m(2) and three at 3·95 mg/m(2). The maximum tolerated dose of ixazomib was established as 2·97 mg/m(2) and the recommended phase 2 dose was 2·23 mg/m(2), which was converted to a 4·0 mg fixed dose based on population pharmacokinetic results. Grade 3 or higher adverse events related to any drug were reported in 41 (63%) patients, including skin and subcutaneous tissue disorders (11 patients, 17%), neutropenia (eight patients, 12%), and thrombocytopenia (five patients, 8%); drug-related peripheral neuropathy of grade 3 or higher occurred in four (6%) patients. Five patients discontinued because of adverse events. In 64 response-evaluable patients, 37 (58%, 95% CI 45-70) had a very good partial response or better. INTERPRETATION: The all-oral combination of weekly ixazomib plus lenalidomide and dexamethasone was generally well tolerated and appeared active in newly diagnosed multiple myeloma. These results support the phase 3 trial development of this combination for multiple myeloma. FUNDING: Millennium Pharmaceuticals, a wholly owned subsidiary of Takeda Pharmaceutical International Company. Proteasome inhibition is an effective treatment strategy for multiple myeloma. With improving survival, attention is increasingly focusing on ease of administration and toxicity profile. Ixazomib is an investigational, orally bioavailable 20S proteasome inhibitor. Sixty patients with relapsed and/or refractory multiple myeloma were enrolled on this phase 1 trial to evaluate safety and tolerability and determine the maximum tolerated dose (MTD) of single-agent, oral ixazomib given weekly for 3 of 4 weeks. Upon MTD determination, patients were enrolled to 4 different cohorts based on relapsed/refractory status and prior bortezomib and carfilzomib exposure. The MTD was determined to be 2.97 mg/m(2). Dose-limiting toxicities were grade 3 nausea, vomiting, and diarrhea in 2 patients, and grade 3 skin rash in 1 patient. Common drug-related adverse events were thrombocytopenia (43%), diarrhea (38%), nausea (38%), fatigue (37%), and vomiting (35%). The observed rate of peripheral neuropathy was 20%, with only 1 grade 3 event reported. Nine (18%) patients achieved a partial response or better, including 8 of 30 (27%) evaluable patients treated at the MTD. Pharmacokinetic studies suggested a long terminal half-life of 3.6 to 11.3 days, supporting once-weekly dosing. This trial was registered at www.clinicaltrials.gov as #NCT00963820. Multiple myeloma is still an incurable disease with pattern of regression and remission followed by multiple relapses raising from the residual myeloma cells surviving even in the patients who achieve complete clinical response to treatment. New antimyeloma drugs such as thalidomide, lenalidomide, and bortezomib have dramatically changed treatment paradigm leading to both tumor reduction and tumor suppression. Much progress has been made, but still many unsolved questions remain. In the mode of sequencing treatment for patients with multiple myeloma, we are still using old drugs such as the alkylating agent melphalan, which continues to play a central role in the transplantation setting. Newer drugs are now emerging and are being tested: monoclonal antibodies, histone deacetylase (romidespsin), MLN9708 (ixazomib) a new oral proteasome inhibitor, carfilzomib, signal transduction modulator perifosine. Many advances have been made, but there is still a long way to go.

Which are the Atg8 homologs in human?

Autophagy (Autophagy-related protein 8 or Atg8p or APG8 or AUT7 or CVT5) is a yeast protein involved in cytoplasm to vacuole transport (Cvt) vesicles and autophagosomes formation. In yeast it is represented by a single gene, the ATG8 family in humans contains 6 members (microtubule-associated protein-1 light chain 3A (MAP1LC3A), MAP1LC3B, MAP1LC3C, GABA(A) receptor-associated protein (GABARAP), GABARAPL1, and GABARAPL2/GATE-16).

[23043107, 22948227, 16303767, 20562859, 22120110, 20723759, 20574168, 23022382, 22302004, 19549685, 20418806, 10856287, 21893048, 21620860, 21862879]

Macroautophagy (hereafter referred to as autophagy) is an evolutionarily conserved catabolic process necessary for normal recycling of cellular constituents and for appropriate response to cellular stress. Although several genes belonging to the core molecular machinery involved in autophagosome formation have been discovered, relatively little is known about the nature of signaling networks controlling autophagy upon intracellular or extracellular stimuli. We discovered ATG8-like proteins (MAP1LC3B, GABARAP and GABARAPL1) as novel interactors of MAPK15/ERK8, a MAP kinase involved in cell proliferation and transformation. Based on the role of these proteins in the autophagic process, we demonstrated that MAPK15 is indeed localized to autophagic compartments and increased, in a kinase-dependent fashion, ATG8-like proteins lipidation, autophagosome formation and SQSTM1 degradation, while decreasing LC3B inhibitory phosphorylation. Interestingly, we also identified a conserved LC3-interacting region (LIR) in MAPK15 responsible for its interaction with ATG8-like proteins, for its localization to autophagic structures and, consequently, for stimulation of the formation of these compartments. Furthermore, we reveal that MAPK15 activity was induced in response to serum and amino-acid starvation and that this stimulus, in turn, required endogenous MAPK15 expression to induce the autophagic process. Altogether, these results suggested a new function for MAPK15 as a regulator of autophagy, acting through interaction with ATG8 family proteins. Also, based on the key role of this process in several human diseases, these results supported the use of this MAP kinase as a potential novel therapeutic target. In yeast, phosphatidylethanolamine is a target of the Atg8 modifier in ubiquitylation-like reactions essential for autophagy. Three human Atg8 (hAtg8) homologs, LC3, GABARAP, and GATE-16, have been characterized as modifiers in reactions mediated by hAtg7 (an E1-like enzyme) and hAtg3 (an E2-like enzyme) as in yeast Atg8 lipidation, but their final targets have not been identified. The results of a recent study in which COS7 cells were incubated with [14C]ethanolamine for 48 h suggested that phosphatidylethanolamine is a target of LC3. However, these results were not conclusive because of the long incubation time. To identify the phospholipid targets of Atg8 homologs, we reconstituted conjugation systems for mammalian Atg8 homologs in vitro using purified recombinant Atg proteins and liposomes. Each purified mutant Atg8 homolog with an exposed C-terminal Gly formed an E1-substrate intermediate with hAtg7 via a thioester bond in an ATP-dependent manner and formed an E2-substrate intermediate with hAtg3 via a thioester bond dependent on ATP and hAtg7. A conjugated form of each Atg8 homolog was observed in the presence of hAtg7, hAtg3, ATP, and liposomes. In addition to phosphatidylethanolamine, in vitro conjugation experiments using synthetic phospholipid liposomes showed that phosphatidylserine is also a target of LC3, GABARAP, and GATE-16. In contrast, thin layer chromatography of phospholipids released on hAtg4B-digestion from endogenous LC3-phospholipid conjugate revealed that phosphatidylethanolamine, but not phosphatidylserine, is the predominant target phospholipid of LC3 in vivo. The discrepancy between in vitro and in vivo reactions suggested that there may be selective factor(s) involved in the endogenous LC3 conjugation system. ATG12, an ubiquitin-like modifier required for macroautophagy, has a single known conjugation target, another autophagy regulator called ATG5. Here, we identify ATG3 as a substrate for ATG12 conjugation. ATG3 is the E2-like enzyme necessary for ATG8/LC3 lipidation during autophagy. ATG12-ATG3 complex formation requires ATG7 as the E1 enzyme and ATG3 autocatalytic activity as the E2, resulting in the covalent linkage of ATG12 onto a single lysine on ATG3. Surprisingly, disrupting ATG12 conjugation to ATG3 does not affect starvation-induced autophagy. Rather, the lack of ATG12-ATG3 complex formation produces an expansion in mitochondrial mass and inhibits cell death mediated by mitochondrial pathways. Overall, these results unveil a role for ATG12-ATG3 in mitochondrial homeostasis and implicate the ATG12 conjugation system in cellular functions distinct from the early steps of autophagosome formation. Autophagy protects cellular homeostasis by capturing cytosolic components and invading pathogens for lysosomal degradation. Autophagy receptors target cargo to autophagy by binding ATG8 on autophagosomal membranes. The expansion of the ATG8 family in higher eukaryotes suggests that specific interactions with autophagy receptors facilitate differential cargo handling. However, selective interactors of ATG8 orthologs are unknown. Here we show that the selectivity of the autophagy receptor NDP52 for LC3C is crucial for innate immunity since cells lacking either protein cannot protect their cytoplasm against Salmonella. LC3C is required for antibacterial autophagy because in its absence the remaining ATG8 orthologs do not support efficient antibacterial autophagy. Structural analysis revealed that the selectivity of NDP52 for LC3C is conferred by a noncanonical LIR, in which lack of an aromatic residue is balanced by LC3C-specific interactions. Our report illustrates that specificity in the interaction between autophagy receptors and autophagy machinery is of functional importance to execute selective autophagy. Atg4 is required for cleaving Atg8, allowing it to be conjugated to phosphatidylethanolamine on phagophore membranes, a key step in autophagosome biogenesis. Deconjugation of Atg8 from autophagosomal membranes could be also a regulatory step in controlling autophagy. Therefore, the activity of Atg4 is important for autophagy and could be a target for therapeutic intervention. In this study, a sensitive and specific method to measure the activity of two Atg4 homologs in mammalian cells, Atg4A and Atg4B, was developed using a fluorescence resonance energy transfer (FRET)-based approach. Thus LC3B and GATE-16, two substrates that could be differentially cleaved by Atg4A and Atg4B, were fused with CFP and YFP at the N- and C-terminus, respectively, allowing FRET to occur. The FRET signals decreased in proportion to the Atg4-mediated cleavage, which separated the two fluorescent proteins. This method is highly efficient for measuring the enzymatic activity and kinetics of Atg4A and Atg4B under in vitro conditions. Applications of the assay indicated that the activity of Atg4B was dependent on its catalytic cysteine and expression level, but showed little changes under several common autophagy conditions. In addition, the assays displayed excellent performance in high throughput format and are suitable for screening and analysis of potential modulators. In summary, the FRET-based assay is simple and easy to use, is sensitive and specific, and is suitable for both routine measurement of Atg4 activity and high-throughput screening. Autophagy is an important catabolic process with roles in cell survival and cell death. It sequesters cytosol and organelles within double-membrane autophagosomes that deliver their contents to lysosomes for degradation. Autophagosome biogenesis is coordinated by the autophagy-related protein 4 (Atg4) family of C54 endopeptidases (Atg4A-Atg4D). These enzymes prime and then later delipidate the autophagosome marker, Atg8. Here, we show that one family member, Atg4D, is cleaved by caspase-3 in vitro and in apoptotic cells. Atg4D is a poor priming and delipidation enzyme in vitro, but truncated DeltaN63 Atg4D displays increased activity against the Atg8 paralogue, gamma-aminobutyric acid receptor-associated protein-like 1 (GABARAP-L1). In living cells, DeltaN63 Atg4D stimulates the delipidation of GABARAP-L1, whereas siRNA silencing of the gene expressing Atg4D abrogates GABARAP-L1 autophagosome formation and sensitises cells to starvation and staurosporine-induced cell death. Interestingly, Atg4D overexpression induces apoptosis, which is preceded by the caspase-independent recruitment of Atg4D to mitochondria and is facilitated by a putative C-terminal Bcl-2 homology 3 (BH3) domain. Atg4D also acquires affinity for damaged mitochondria in cells treated with hydrogen peroxide. These data suggest that Atg4D is an autophagy regulator that links mitochondrial dysfunction with apoptosis. Glycogen, a branched polymer of glucose, acts as an intracellular carbon and energy reserve in many tissues and cell types. An important pathway for its degradation is by transport to lysosomes in an autophagy-like process. It has been proposed that starch-binding domain-containing protein 1 (Stbd1) may participate in this mechanism by anchoring glycogen to intracellular membranes. In addition, Stbd1 has been reported to interact with a known autophagy protein, GABARAPL1, a member of the Atg8 family. Here, we confirm this interaction and identify an Atg8 interacting motif (AIM) in Stbd1 necessary for GABARAPL1 binding as judged by co-immunoprecipitation from cell extracts and co-localization in cells as evidenced by immunofluorescence microscopy. The AIM sequence of Stbd1 (200)HEEWEMV(206) lies within a predicted disordered region of the molecule and fits the consensus of other AIM sequences in cargo-specifying proteins such as p62 and Nix. Mutation of the AIM, including single point mutations of either W203 or V206, eliminated the co-localization of Stbd1 with both over-expressed and endogenous GABARAPL1. Stbd1 may therefore function as a novel cargo binding protein that delivers glycogen to lysosomes in an autophagic pathway that could be termed "glycophagy".

To which family does the Zika virus belong?

The Zika virus belongs to the family Flaviviridae.

[25310102]

BACKGROUND: Zika virus (ZIKV; genus Flavivirus, family Flaviviridae) is maintained in a zoonotic cycle between arboreal Aedes spp. mosquitoes and nonhuman primates in African and Asian forests. Spillover into humans has been documented in both regions and the virus is currently responsible for a large outbreak in French Polynesia. ZIKV amplifications are frequent in southeastern Senegal but little is known about their seasonal and spatial dynamics. The aim of this paper is to describe the spatio-temporal patterns of the 2011 ZIKV amplification in southeastern Senegal. METHODOLOGY/FINDINGS: Mosquitoes were collected monthly from April to December 2011 except during July. Each evening from 18:00 to 21:00 hrs landing collections were performed by teams of 3 persons working simultaneously in forest (canopy and ground), savannah, agriculture, village (indoor and outdoor) and barren land cover sites. Mosquitoes were tested for virus infection by virus isolation and RT-PCR. ZIKV was detected in 31 of the 1,700 mosquito pools (11,247 mosquitoes) tested: Ae. furcifer (5), Ae. luteocephalus (5), Ae. africanus (5), Ae. vittatus (3), Ae. taylori, Ae. dalzieli, Ae. hirsutus and Ae. metallicus (2 each) and Ae. aegypti, Ae. unilinaetus, Ma. uniformis, Cx. perfuscus and An. coustani (1 pool each) collected in June (3), September (10), October (11), November (6) and December (1). ZIKV was detected from mosquitoes collected in all land cover classes except indoor locations within villages. The virus was detected in only one of the ten villages investigated. CONCLUSIONS/SIGNIFICANCE: This ZIKV amplification was widespread in the Kédougou area, involved several mosquito species as probable vectors, and encompassed all investigated land cover classes except indoor locations within villages. Aedes furcifer males and Aedes vittatus were found infected within a village, thus these species are probably involved in the transmission of Zika virus to humans in this environment.

Has the fungus Ashbya gossypii got many nuclei that share cytoplasm?

Yes, Ashbya gossypii has a budding yeast-like genome but grows exclusively as multinucleated hyphae.

[16449188, 24094857, 23015595, 16023404, 21737675, 21642510, 17158735, 20844079, 19910487, 20053682, 17122387, 16899511, 11181180, 22267774, 23771903]

Synchronous mitosis is common in multinucleated cells. We analyzed a unique asynchronous nuclear division cycle in a multinucleated filamentous fungus, Ashbya gossypii. Nuclear pedigree analysis and observation of GFP-labeled spindle pole bodies demonstrated that neighboring nuclei in A. gossypii cells are in different cell cycle stages despite close physical proximity. Neighboring nuclei did not differ significantly in their patterns of cyclin protein localization such that both G1 and mitotic cyclins were present regardless of cell cycle stage, suggesting that the complete destruction of cyclins is not occurring in this system. Indeed, the expression of mitotic cyclin lacking NH(2)-terminal destruction box sequences did not block cell cycle progression. Cells lacking AgSic1p, a predicted cyclin-dependent kinase (CDK) inhibitor, however, showed aberrant multipolar spindles and fragmented nuclei that are indicative of flawed mitoses. We hypothesize that the continuous cytoplasm in these cells promoted the evolution of a nuclear division cycle in which CDK inhibitors primarily control CDK activity rather than oscillating mitotic cyclin proteins. We report the mechanistic basis guiding the migration pattern of multiple nuclei in hyphae of Ashbya gossypii. Using electron tomography, we reconstructed the cytoplasmic microtubule (cMT) cytoskeleton in three tip regions with a total of 13 nuclei and also the spindle microtubules of four mitotic nuclei. Each spindle pole body (SPB) nucleates three cMTs and most cMTs above a certain length grow according to their plus-end structure. Long cMTs closely align for several microns along the cortex, presumably marking regions where dynein generates pulling forces on nuclei. Close proximity between cMTs emanating from adjacent nuclei was not observed. The majority of nuclei carry duplicated side-by-side SPBs, which together emanate an average of six cMTs, in most cases in opposite orientation with respect to the hyphal growth axis. Such cMT arrays explain why many nuclei undergo short-range back and forth movements. Only occasionally do all six cMTs orient in one direction, a precondition for long-range nuclear bypassing. Following mitosis, daughter nuclei carry a single SPB with three cMTs. The increased probability that all three cMTs orient in one direction explains the high rate of nuclear bypassing observed in these nuclei. The A. gossypii mitotic spindle was found to be structurally similar to that of Saccharomyces cerevisiae in terms of nuclear microtubule (nMT) number, length distribution and three-dimensional organization even though the two organisms differ significantly in chromosome number. Our results suggest that two nMTs attach to each kinetochore in A. gossypii and not only one nMT like in S. cerevisiae. A few years ago, A. gossypii became recognized as an attractive model to study the growth of long and multinucleated fungal cells (hyphae) because of its small genome, haploid nuclei, and efficient gene targeting methods. It is generally assumed that a better understanding of filamentous fungal growth will greatly stimulate the development of novel fungicides. The use of Ashbya gossypii as a model is particularly promising because of the high level of gene order conservation (synteny) between the genomes of A. gossypii and the yeast Saccharomyces cerevisiae. Thus, a similar set of genes seems to control the surprisingly different growth modes of these two organisms, which predicts that orthologous growth control genes might not play identical cellular roles in both systems. Analyzing the phenotypes of A. gossypii mutants lacking factors with known functions in yeast morphogenesis and nuclear dynamics confirm this hypothesis. Comparative genomics of both organisms also reveals rare examples of differences in the gene sets for some cellular processes, which as shown for phosphate homeostasis can be associated with differences in control levels. During filamentous fungus development, multinucleated hyphae employ a system for long-range nuclear migration to maintain an equal nuclear density. A decade ago the microtubule motor dynein was shown to play a central role in this process. Previous studies with Ashbya gossypii revealed extensive bidirectional movements and bypassings of nuclei, an autonomous cytoplasmic microtubule (cMT) cytoskeleton emanating from each nucleus, and pulling of nuclei by sliding of cMTs along the cortex. Here, we show that dynein is the sole motor for bidirectional movements and bypassing because these movements are concomitantly decreased in mutants carrying truncations of the dynein heavy-chain DYN1 promoter. The dynactin component Jnm1, the accessory proteins Dyn2 and Ndl1, and the potential dynein cortical anchor Num1 are also involved in the dynamic distribution of nuclei. In their absence, nuclei aggregate to different degrees, whereby the mutants with dense nuclear clusters grow extremely long cMTs. As in budding yeast, we found that dynein is delivered to cMT plus ends, and its activity or processivity is probably controlled by dynactin and Num1. Together with its role in powering nuclear movements, we propose that dynein also plays (directly or indirectly) a role in the control of cMT length. Those combined dynein actions prevent nuclear clustering in A. gossypii and thus reveal a novel cellular role for dynein. Ashbya gossypii has a budding yeast-like genome but grows exclusively as multinucleated hyphae. In contrast to budding yeast where positioning of nuclei at the bud neck is a major function of cytoplasmic microtubules (cMTs), A. gossypii nuclei are constantly in motion and positioning is not an issue. To investigate the role of cMTs in nuclear oscillation and bypassing, we constructed mutants potentially affecting cMT lengths. Hyphae lacking the plus (+)end marker Bik1 or the kinesin Kip2 cannot polymerize long cMTs and lose wild-type nuclear movements. Interestingly, hyphae lacking the kinesin Kip3 display longer cMTs concomitant with increased nuclear oscillation and bypassing. Polymerization and depolymerization rates of cMTs are 3 times higher in A. gossypii than in budding yeast and cMT catastrophes are rare. Growing cMTs slide along the hyphal cortex and exert pulling forces on nuclei. Surprisingly, a capture/shrinkage mechanism seems to be absent in A. gossypii. cMTs reaching a hyphal tip do not shrink, and cMT +ends accumulate in hyphal tips. Thus, differences in cMT dynamics and length control between budding yeast and A. gossypii are key elements in the adaptation of the cMT cytoskeleton to much longer cells and much higher degrees of nuclear mobilities. Cyclin protein behavior has not been systematically investigated in multinucleated cells with asynchronous mitoses. Cyclins are canonical oscillating cell cycle proteins, but it is unclear how fluctuating protein gradients can be established in multinucleated cells where nuclei in different stages of the division cycle share the cytoplasm. Previous work in A. gossypii, a filamentous fungus in which nuclei divide asynchronously in a common cytoplasm, demonstrated that one G1 and one B-type cyclin do not fluctuate in abundance across the division cycle. We have undertaken a comprehensive analysis of all G1 and B-type cyclins in A. gossypii to determine whether any of the cyclins show periodic abundance across the cell cycle and to examine whether cyclins exhibit functional redundancy in such a cellular environment. We localized all G1 and B-type cyclins and notably found that only AgClb5/6p varies in subcellular localization during the division cycle. AgClb5/6p is lost from nuclei at the meta-anaphase transition in a D-box-dependent manner. These data demonstrate that efficient nuclear autonomous protein degradation can occur within multinucleated cells residing in a common cytoplasm. We have shown that three of the five cyclins in A. gossypii are essential genes, indicating that there is minimal functional redundancy in this multinucleated system. In addition, we have identified a cyclin, AgClb3/4p, that is essential only for sporulation. We propose that the cohabitation of different cyclins in nuclei has led to enhanced substrate specificity and limited functional redundancy within classes of cyclins in multinucleated cells. We have followed the migration of GFP-labelled nuclei in multinucleate hyphae of Ashbya gossypii. For the first time we could demonstrate that the mode of long range nuclear migration consists of oscillatory movements of nuclei with, on average, higher amplitudes in the direction of the growing tip. We could also show that mitotic division proceeds at a constant rate of 0. 64 microm/minute which differs from the biphasic kinetics described for the yeast Saccharomyces cerevisiae. Furthermore we were able to identify the microtubule-based motor dynein as a key element in the control of long range nuclear migration. For other filamentous fungi it had already been demonstrated that inactivating mutations in dynein led to severe problems in nuclear migration, i.e. generation of long nuclei-free hyphal tips and clusters of nuclei throughout the hyphae. This phenotype supported the view that dynein is important for the movement of nuclei towards the tip. In A. gossypii the opposite seems to be the case. A complete deletion of the dynein heavy chain gene leads to nuclear clusters exclusively at the hyphal tips and to an essentially nucleus-free network of hyphal tubes and branches. Anucleate hyphae and branches in the vicinity of nuclear clusters show actin cables and polarized actin patches, as well as microtubules. The slow growth of this dynein null mutant could be completely reverted to wild-type-like growth in the presence of benomyl, which can be explained by the observed redistribution of nuclei in the hyphal network. Ashbya gossypii grows as multinucleated and constantly elongating hyphae. Nuclei are in continuous forward and backward motion, also move during mitosis, and frequently bypass each other. Whereas these nuclear movements are well documented, comparatively little is known about the density and morphology of organelles which very likely influence these movements. To understand the three-dimensional subcellular organization of hyphae at high resolution, we performed large-scale electron tomography of the tip regions in A. gossypii. Here, we present a comprehensive space-filling model in which most membrane-limited organelles including nuclei, mitochondria, endosomes, multivesicular bodies, vacuoles, autophagosomes, peroxisomes, and vesicles are modeled. Nuclei revealed different morphologies and protrusions filled by the nucleolus. Mitochondria are very abundant and form a tubular network with a polarized spherical fraction. The organelles of the degradative pathways show a clustered organization. By analyzing vesicle-like bodies, we identified three size classes of electron-dense vesicles (∼200, ∼150, and ∼100 nm) homogeneously distributed in the cytoplasm which most likely represent peroxisomes. Finally, coated and uncoated vesicles with approximately 40-nm diameters show a polarized distribution toward the hyphal tip with the coated vesicles preferentially localizing at the hyphal periphery.

Which is the molecular mechanism underlying K-ras alterations in carcinomas?

Activating point mutations most frequently in codon 12

[19783717, 8613066, 19826477, 12697967, 21779504, 16757361, 16166322, 21886451, 21626008, 19509115, 8178941]

BACKGROUND: Activating mutations in one allele of an oncogene (heterozygous mutations) are widely believed to be sufficient for tumorigenesis. However, mutant allele specific imbalance (MASI) has been observed in tumors and cell lines harboring mutations of oncogenes. METHODOLOGY/PRINCIPAL FINDINGS: We determined 1) mutational status, 2) copy number gains (CNGs) and 3) relative ratio between mutant and wild type alleles of KRAS, BRAF, PIK3CA and EGFR genes by direct sequencing and quantitative PCR assay in over 400 human tumors, cell lines, and xenografts of lung, colorectal, and pancreatic cancers. Examination of a public database indicated that homozygous mutations of five oncogenes were frequent (20%) in 833 cell lines of 12 tumor types. Our data indicated two major forms of MASI: 1) MASI with CNG, either complete or partial; and 2) MASI without CNG (uniparental disomy; UPD), due to complete loss of wild type allele. MASI was a frequent event in mutant EGFR (75%) and was due mainly to CNGs, while MASI, also frequent in mutant KRAS (58%), was mainly due to UPD. Mutant: wild type allelic ratios at the genomic level were precisely maintained after transcription. KRAS mutations or CNGs were significantly associated with increased ras GTPase activity, as measured by ELISA, and the two molecular changes were synergistic. Of 237 lung adenocarcinoma tumors, the small number with both KRAS mutation and CNG were associated with shortened survival. CONCLUSIONS: MASI is frequently present in mutant EGFR and KRAS tumor cells, and is associated with increased mutant allele transcription and gene activity. The frequent finding of mutations, CNGs and MASI occurring together in tumor cells indicates that these three genetic alterations, acting together, may have a greater role in the development or maintenance of the malignant phenotype than any individual alteration. Somatic, gain-of-function mutations in ras genes were the first specific genetic alterations identified in human cancer about 3 decades ago. Studies during the last quarter century have characterized the Ras proteins as essential components of signaling networks controlling cellular proliferation, differentiation, or survival. The oncogenic mutations of the H-ras, N-ras, or K-ras genes frequently found in human tumors are known to throw off balance the normal outcome of those signaling pathways, thus leading to tumor development. Oncogenic mutations in a number of other upstream or downstream components of Ras signaling pathways (including membrane RTKs or cytosolic kinases) have been detected more recently in association with a variety of cancers. Interestingly, the oncogenic Ras mutations and the mutations in other components of Ras/MAPK signaling pathways appear to be mutually exclusive events in most tumors, indicating that deregulation of Ras-dependent signaling is the essential requirement for tumorigenesis. In contrast to sporadic tumors, separate studies have identified germline mutations in Ras and various other components of Ras signaling pathways that occur in specific association with a number of different familial, developmental syndromes frequently sharing common phenotypic cardiofaciocutaneous features. Finally, even without being a causative force, defective Ras signaling has been cited as a contributing factor to many other human illnesses, including diabetes and immunological and inflammatory disorders. We aim this review at summarizing and updating current knowledge on the contribution of Ras mutations and altered Ras signaling to development of various tumoral and nontumoral pathologies. Activating K-ras mutations are found in approximately 90% of pancreatic carcinomas and may contribute to the poor prognosis of these tumors. Because radiotherapy is frequently used in pancreatic cancer treatment, we assessed the contribution of oncogenic K-ras signaling to pancreatic cancer radiosensitivity. Seven human pancreatic carcinoma lines with activated K-ras and two cell lines with wild-type ras were used to examine clonogenic cell survival after Ras inhibition. Ras inhibition was accomplished by small interfering RNA (siRNA) knockdown of K-ras expression and by blocking Ras processing using a panel of prenyltransferase inhibitors of differing specificity for the two prenyltransferases that modify K-Ras. K-ras knockdown by siRNA or inhibition of prenyltransferase activity resulted in radiation sensitization in vitro and in vivo in tumors with oncogenic K-ras mutations. Inhibition of farnesyltransferase alone was sufficient to radiosensitize most K-ras mutant tumors, although K-Ras prenylation was not blocked. These results show that inhibition of activated K-Ras can promote radiation killing of pancreatic carcinoma in a superadditive manner. The finding that farnesyltransferase inhibition alone radiosensitizes tumors with K-ras mutations implies that a farnesyltransferase inhibitor-sensitive protein other than K-Ras may contribute to survival in the context of mutant K-ras. Farnesyltransferase inhibitors could therefore be of use as sensitizers for pancreatic carcinoma radiotherapy. Mutations in the K-ras oncogene and in the p53 tumor suppressor gene are commonly identified in sporadic cases of pancreatic adenocarcinoma. Although these genes might serve as useful markers for early diagnosis of pancreatic carcinoma in patients at risk for the development of this disease, familial pancreatic carcinomas have not been studied for these mutations. We recently had the opportunity to examine a pancreas prophylactically removed from a patient with a strong family history of pancreatic carcinoma. This gave us the unique opportunity to study the early events in the development of familial adenocarcinoma of the pancreas. Histopathological examination of the pancreas revealed multifocal papillary and nonpapillary mucinous duct hyperplasia. Seven of these foci were microdissected and analyzed for K-ras and p53 mutations. The K-ras mutations were detected by combined mutant-enriched polymerase chain reaction-restriction fragment length polymorphism analysis and characterized further by allele-specific oligonucleotide hybridization. Five of the seven duct lesions harbored activating point mutations in codon 12 of K-ras; a G to A transition was found in four and a G to C transversion in one. In contrast, these lesions did not harbor detectable p53 mutations as determined by denaturing gradient gel electrophoresis of exons 5 to 8, nor was there overexpression of the p53 protein as determined by immunohistochemistry. These findings suggest that mutations in K-ras represent an early event in the pathogenesis of pancreatic carcinoma. In addition, monitoring of patients with a strong family history of pancreatic carcinoma for K-ras mutations may identify patients at risk for the development of invasive carcinoma.

Is microRNA(miRNA) 30 involved in post-ischemic cardiac remodeling?

Myocardial remodeling after an ischemic insult involves extracellular matrix proteins with increased fibrosis Initial experimental data indicate that miRNA 30 decreases CTGF a key molecule in the process of fibrosis, by directly downregulating the production of CTGF

[22352753, 21434842, 22038740, 19096030]

miRNAs are small non-coding RNAs that regulate post-transcriptionally gene expression by degradation or translational repression of specific target mRNAs. In the 90s, lin-4 and let-7 were firstly identified as small regulatory RNAs able to control C. elegans larval development, by specifically targeting the 3'UTR of lin-14 and lin-28, respectively. These findings have introduced a novel and wide layer of complexity in the regulation of mRNA and protein expression. Lin-4 and let-7 are now considered the founding members of an abundant class of small fine-tuned RNAs, called microRNAs (miRNAs), in viruses, green algae, plants, flies, worms, and in mammals. In humans, the estimated number of genes encoding for miRNAs is as high as 1000 and around 30% of the protein-coding genes are post-transcriptionally controlled by miRNAs. This article reviews the role of miRNAs in regulating several biological responses in muscle cells, ranging from proliferation, differentiation and adaptation to stress cues. Cardiac and skeletal muscles are powerful examples to summarize the activity of miRNAs in cell fate specification, lineage differentiation and metabolic pathways. Indeed, specific miRNAs control the number of proliferating muscle progenitors to guarantee the proper formation of the heart and muscle fibers and to assure the self-renewal of muscle progenitors during adult tissue regeneration. On the other side, several other miRNAs promote the differentiation of muscle progenitors into skeletal myofibers or into cardiomyocytes, where metabolic activity, survival and remodeling process in response to stress, injury and chronic diseases are also fine-tuned by miRNAs. INTRODUCTION: Coronary artery disease (CAD) is still the leading cause of death in industrialized nations. Even though revascularization strategies such as percutaneous coronary intervention (PCI) and coronary artery bypass graft surgery (CABG) as well as drug therapy have significantly reduced mortality, about 30% of patients will develop chronic heart failure over time. Ischemic heart disease and heart failure are characterized by an adverse remodeling of the heart, featuring cardiomyocyte hypertrophy, increased fibrosis and capillary rarification. AREAS COVERED: Beside an assessment of current vector systems, this review focuses on potential target genes affecting angiogenesis/arteriogenesis and contractility. The potential of micro RNA (miRNA) modulation for the de-repression of survival and pro-angiogenic genes is discussed. Since gene therapy of the target region is preferable to avoid systemic contamination, application routes are discussed. EXPERT OPINION: miRNAs are a promising new development for successful gene therapy, especially for acute myocardial infarction since their miRNA antagonists are easy to apply and appear to be selectively absorbed by the ischemic myocardial tissue. Rapid uptake and prolonged presence of known antimirs and antagomirs support this notion. For ischemic heart disease the most promising gene therapeutic approach seems to be the regional intravenous application of suitable AAV vectors and vascular growth factors, providing the full scope of angiogenesis, vessel maturation and collateral growth optionally combined with genes enhancing contractility. Myocardial ischaemia/reperfusion (I/R)-induced remodelling generally includes cell death (necrosis and apoptosis), myocyte hypertrophy, angiogenesis, cardiac fibrosis, and myocardial dysfunction. It is becoming increasingly clear that microRNAs (miRNAs or miRs), a group of highly conserved small (∼18-24 nucleotide) non-coding RNAs, fulfil specific functions in the reperfused myocardium towards post-infarct remodelling. While miR-21, -133, -150, -195, and -214 regulate cardiomyocyte hypertrophy, miR-1/-133 and miR-208 have been elucidated to influence myocardial contractile function. In addition, miR-21, -24, -133, -210, -494, and -499 appear to protect myocytes against I/R-induced apoptosis, whereas miR-1, -29, -199a, and -320 promote apoptosis. Myocardial fibrosis can be regulated by the miR-29 family and miR-21. Moreover, miR-126 and miR-210 augment I/R-induced angiogenesis, but miR-24, -92a, and -320 suppress post-infarct neoangiogenesis. In this review, we summarize the latest advances in the identification of myocardial ischaemia-associated miRNAs and their functional significance in the modulation of I/R-triggered remodelling. Controversial effects of some miRNAs in post-infarct remodelling will be also discussed. The myocardium of the failing heart undergoes a number of structural alterations, most notably hypertrophy of cardiac myocytes and an increase in extracellular matrix proteins, often seen as primary fibrosis. Connective tissue growth factor (CTGF) is a key molecule in the process of fibrosis and therefore seems an attractive therapeutic target. Regulation of CTGF expression at the promoter level has been studied extensively, but it is unknown how CTGF transcripts are regulated at the posttranscriptional level. Here we provide several lines of evidence to show that CTGF is importantly regulated by 2 major cardiac microRNAs (miRNAs), miR-133 and miR-30. First, the expression of both miRNAs was inversely related to the amount of CTGF in 2 rodent models of heart disease and in human pathological left ventricular hypertrophy. Second, in cultured cardiomyocytes and fibroblasts, knockdown of these miRNAs increased CTGF levels. Third, overexpression of miR-133 or miR-30c decreased CTGF levels, which was accompanied by decreased production of collagens. Fourth, we show that CTGF is a direct target of these miRNAs, because they directly interact with the 3' untranslated region of CTGF. Taken together, our results indicate that miR-133 and miR-30 importantly limit the production of CTGF. We also provide evidence that the decrease of these 2 miRNAs in pathological left ventricular hypertrophy allows CTGF levels to increase, which contributes to collagen synthesis. In conclusion, our results show that both miR-133 and miR-30 directly downregulate CTGF, a key profibrotic protein, and thereby establish an important role for these miRNAs in the control of structural changes in the extracellular matrix of the myocardium.

List all clinical trials of the polypill.

'Use of a Multidrug Pill In Reducing cardiovascular Events' (UMPIRE) trial, European Clinical Trials database, as EudraCT: 2009-016278-34 and the Clinical Trials Registry, India as CTRI/2010/091/000250. 'IMProving Adherence using Combination Therapy (IMPACT)', Australian New Zealand Clinical Trial Registry (ACTRN12606000067572). 'Kanyini Guidelines Adherence with the Polypill (Kanyini-GAP)' Phase II study of the Polycap, double-blind, randomised trial, registered with ClinicalTrials.gov, number NCT00443794 Second Indian Polycap Study, TIPS-2 Cluster Randomized Usual Care vs Caduet Investigation Assessing Long-term-risk (CRUCIAL trial) GEMINI trial, 14-week, open-label trial conducted in 1220 patients from the USA GEMINI-Australia, Asia, Latin America, Africa/Middle East (AALA) study JEWEL study program, with JEWEL 1 conducted among 1138 patients from the UK and Canada and JEWEL 2 conducted in 1107 patients from Europe CAPABLE54, the Clinical Utility of Caduet in Simultaneously Achieving Blood Pressure and Lipid End Points , in the USA CUSP (The Caduet® in an Untreated Subject Population trial) TOGETHER trial A randomised controlled trial in seven countries – Australia, Brazil, India, Netherlands , New Zealand , United Kingdom and United States. Australian New Zealand Clinical Trials Registry (ACTRN 12607000099426)

[21647425, 18227490, 19339045, 21777702, 20687931, 21205325, 20334446, 23038750, 15670547, 22162939, 21682553, 22787067, 16479100, 15830173, 22080542]

BACKGROUND: There has been widespread interest in the potential of combination cardiovascular medications containing aspirin and agents to lower blood pressure and cholesterol ('polypills') to reduce cardiovascular disease. However, no reliable placebo-controlled data are available on both efficacy and tolerability. METHODS: We conducted a randomised, double-blind placebo-controlled trial of a polypill (containing aspirin 75 mg, lisinopril 10 mg, hydrochlorothiazide 12.5 mg and simvastatin 20 mg) in 378 individuals without an indication for any component of the polypill, but who had an estimated 5-year cardiovascular disease risk over 7.5%. The primary outcomes were systolic blood pressure (SBP), LDL-cholesterol and tolerability (proportion discontinued randomised therapy) at 12 weeks follow-up. FINDINGS: At baseline, mean BP was 134/81 mmHg and mean LDL-cholesterol was 3.7 mmol/L. Over 12 weeks, polypill treatment reduced SBP by 9.9 (95% CI: 7.7 to 12.1) mmHg and LDL-cholesterol by 0.8 (95% CI 0.6 to 0.9) mmol/L. The discontinuation rates in the polypill group compared to placebo were 23% vs 18% (RR 1.33, 95% CI 0.89 to 2.00, p = 0.2). There was an excess of side effects known to the component medicines (58% vs 42%, p = 0.001), which was mostly apparent within a few weeks, and usually did not warrant cessation of trial treatment. CONCLUSIONS: This polypill achieved sizeable reductions in SBP and LDL-cholesterol but caused side effects in about 1 in 6 people. The halving in predicted cardiovascular risk is moderately lower than previous estimates and the side effect rate is moderately higher. Nonetheless, substantial net benefits would be expected among patients at high risk. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12607000099426. The reality of primary and secondary prevention of cardiovascular complications in people with diabetes is alarming, even in developed countries with a well-structured medical system. Even though therapeutic targets have been more clearly defined during the last decades, their implementation is still suboptimal. Financial and structural reasons, insufficient information of physicians and patients, along with a low compliance of the latter are only a few reasons that have been incriminated. To eliminate some of these inconveniences, attempts to standardize and simplify therapies have been made. Treatment with aspirin and statin for every patient with diabetes has been postulated. Some went even further, developing the concept of a "polypill," an integrated pharmacological agent with up to six different compounds meant to prevent cardiovascular disease in the broad population. Likewise, the idea of a "polymeal" tries to implement healthy nutrients into the populations' lifestyle in a standardized fashion. Our article highlights some of the advantages and pitfalls of these concepts and reflects our point of view with regard to some treatment aspects in people with diabetes. As part of a pro and contra discussion, our article is arguing against the use of statins in all patients with diabetes and especially against the indiscriminate use of a polypill. BACKGROUND: The combination of three blood-pressure-lowering drugs at low doses, with a statin, aspirin, and folic acid (the polypill), could reduce cardiovascular events by more than 80% in healthy individuals. We examined the effect of the Polycap on blood pressure, lipids, heart rate, and urinary thromboxane B2, and assessed its tolerability. METHODS: In a double-blind trial in 50 centres in India, 2053 individuals without cardiovascular disease, aged 45-80 years, and with one risk factor were randomly assigned, by a central secure website, to the Polycap (n=412) consisting of low doses of thiazide (12.5 mg), atenolol (50 mg), ramipril (5 mg), simvastatin (20 mg), and aspirin (100 mg) per day, or to eight other groups, each with about 200 individuals, of aspirin alone, simvastatin alone, hydrochlorthiazide alone, three combinations of the two blood-pressure-lowering drugs, three blood-pressure-lowering drugs alone, or three blood-pressure-lowering drugs plus aspirin. The primary outcomes were LDL for the effect of lipids, blood pressure for antihypertensive drugs, heart rate for the effects of atenolol, urinary 11-dehydrothromboxane B2 for the antiplatelet effects of aspirin, and rates of discontinuation of drugs for safety. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00443794. FINDINGS: Compared with groups not receiving blood-pressure-lowering drugs, the Polycap reduced systolic blood pressure by 7.4 mm Hg (95% CI 6.1-8.1) and diastolic blood pressure by 5.6 mm Hg (4.7-6.4), which was similar when three blood-pressure-lowering drugs were used, with or without aspirin. Reductions in blood pressure increased with the number of drugs used (2.2/1.3 mm Hg with one drug, 4.7/3.6 mm Hg with two drugs, and 6.3/4.5 mm Hg with three drugs). Polycap reduced LDL cholesterol by 0.70 mmol/L (95% CI 0.62-0.78), which was less than that with simvastatin alone (0.83 mmol/L, 0.72-0.93; p=0.04); both reductions were greater than for groups without simvastatin (p<0.0001). The reductions in heart rate with Polycap and other groups using atenolol were similar (7.0 beats per min), and both were significantly greater than that in groups without atenolol (p<0.0001). The reductions in 11-dehydrothromboxane B2 were similar with the Polycap (283.1 ng/mmol creatinine, 95% CI 229.1-337.0) compared with the three blood-pressure-lowering drugs plus aspirin (350.0 ng/mmol creatinine, 294.6-404.0), and aspirin alone (348.8 ng/mmol creatinine, 277.6-419.9) compared with groups without aspirin. Tolerability of the Polycap was similar to that of other treatments, with no evidence of increasing intolerability with increasing number of active components in one pill. INTERPRETATION: This Polycap formulation could be conveniently used to reduce multiple risk factors and cardiovascular risk. BACKGROUND: Cardiovascular disease (CVD) is the leading cause of death, and principal reason for the large difference in life expectancy between indigenous Māori and the non-indigenous population in New Zealand. CVD guidelines recommend that people who are at high risk or who have had previous CVD should be offered aspirin, blood pressure lowering and lipid lowering therapies. However, prescribing and adherence rates are low and CVD events remain high. AIM: To assess whether a medication strategy using a fixed dose combination pill ('polypill') could improve prescribing and adherence to recommended medications, lower blood pressure and improve lipids compared with current care over 12 months. METHODS: IMProving Adherence using Combination Therapy (IMPACT) is an open-label randomised controlled trial comparing a once-daily polypill containing four preventive medications with usual care. Six hundred participants who have had previous CVD events or are at high risk of CVD will be enrolled, including 300 Māori. Participants are identified, enrolled and prescribed either the polypill or current medications at their usual primary health care practice, with medications (including the polypill) dispensed through local community pharmacies. The polypill contains 75 mg aspirin, 40 mg simvastatin, 10mg lisinopril and either 12.5mg hydrochlorothiazide or 50mg atenolol. Primary outcomes are adherence to guidelines-recommended medications and changes in systolic blood pressure and low density lipoprotein at 12 months. Secondary outcomes include other lipids, medication dispensing, barriers to adherence, CVD and other serious adverse events, quality of life and prescriber acceptability. The trial is registered with the Australian New Zealand Clinical Trial Registry (ACTRN12606000067572). BACKGROUND: The Polycap (polypill; aspirin [acetylsalicylic acid], ramipril, simvastatin, atenolol, and hydrochlorothiazide) was found to be safe and effective for reducing multiple cardiovascular risk factors in The Indian Polycap Study (TIPS). OBJECTIVE: We evaluated the bioavailability of each ingredient of the Polycap and determined any drug-drug interactions relative to single component reference preparations. METHODS: The bioavailability of the ingredients of the Polycap (T; test) when formulated as a single capsule was compared with that of identical capsules with each of its ingredients administered separately (R; reference) in a five-arm, randomized, single-dose, two-period, two-treatment, two-sequence, crossover trial with at least a 2-week washout period in a total of 195 healthy volunteers. Plasma concentrations of each drug and, where applicable, its active metabolite were measured using validated liquid chromatography-tandem mass spectrometry and ultra-performance liquid chromatography. Mean pharmacokinetic parameters and their standard deviations were computed for each analyte. RESULTS: Comparative bioavailability was computed and no drug-drug interactions and no difference in comparative bioavailability were concluded for each ingredient based on point estimates of the T/R ratio of the geometric means falling within 80-125% for peak plasma concentration (C(max)), area under the plasma concentration-time curve from time zero to the last measurable concentration (AUC(t)), and AUC from time zero to infinity (AUC(infinity)). The T/R ratio for C(max), AUC(t) and AUC(infinity) was within 80-125% for atenolol, hydrochlorothiazide, ramipril, ramiprilat and dose-normalized salicylic acid. However, for simvastatin, the T/R point estimates for C(max), AUC(t) and AUC(infinity) for Ln-transformed data were significantly lower ( approximately 3-4%) than the lower bound of 80%. For its active metabolite, simvastatin acid, these estimates were significantly higher ( approximately 25-35%) than the higher bound of 125%. Thus, the increased bioavailability of active simvastatin acid appeared to compensate for the loss of bioavailability of simvastatin. CONCLUSION: The Polycap was found to be effective and safe in the previously published TIPS trial. The present study in healthy volunteers establishes that Polycap is safe (no serious adverse events) and well tolerated, and that there is no indication of pharmacokinetic drug-drug interactions for any of the ingredients, with their bioavailabilities being well preserved. A "polypill" for the primary prevention of cardiovascular disease has been proposed. We estimated the projected benefit of a secondary prevention "poly-portfolio" strategy, including pharmacologic and lifestyle approaches for those with coronary heart disease (CHD) or stroke. Based on recent clinical trial results and clinical guidelines, combinations of a high-dose statin, low to standard doses of antihypertensive therapy, aspirin, omega-3 fish oil, cardiac rehabilitation, and diet were evaluated. Patients with CHD, post-myocardial infarction (MI), or stroke were projected to experience 84%, 91%, and 77% reductions, respectively, in CHD events from a pharmacologic approach. Numbers of those needed to treat (NNT) for 5 years were 9 to 11 to prevent 1 CHD event, and 21 to prevent 1 stroke. Post-MI patients were projected to experience a 93% reduction in the risk of CHD death (NNT 16) from a pharmacologic approach and a 97% reduction in the risk of CHD death (NNT 15) with the addition of lifestyle changes. A secondary prevention polyportfolio holds great promise for reducing the burden of cardiovascular disease in the highest risk patients. Clinical guidelines now recognize the importance of a multifactorial approach to managing cardiovascular (CV) risk. This idea was taken a step further with the concept of the Polypill™. There are, however, considerable patent, pharmacokinetic, pharmacodynamic, registration, and cost implications that will need to be overcome before the Polypill™ or other single-pill combinations of CV medications become widely available. However, a medication targeting blood pressure (BP) and lipids provides much of the proposed benefits of the Polypill™. A single-pill combination of the antihypertensive amlodipine besylate and the lipid-lowering medication atorvastatin calcium (SPAA) is currently available in many parts of the world. This review describes the rationale for this combination therapy and the clinical trials that have demonstrated that these two agents can be combined without the loss of efficacy for either agent or an increase in the incidence of adverse events. The recently completed Cluster Randomized Usual Care vs Caduet Investigation Assessing Long-term-risk (CRUCIAL trial) is discussed in detail. CRUCIAL was a 12-month, international, multicenter, prospective, open-label, parallel design, cluster-randomized trial, which demonstrated that a proactive intervention strategy based on SPAA in addition to usual care (UC) had substantial benefits on estimated CV risk, BP, and lipids over continued UC alone. Adherence with antihypertensive and lipid-lowering therapies outside of the controlled environment of clinical trials is very low (~30%-40% at 12 months). Observational studies have demonstrated that improving adherence to lipid-lowering and antihypertensive medications may reduce CV events. One means of improving adherence is the use of single-pill combinations. Real-world observational studies have demonstrated that patients are more adherent to SPAA than co-administered antihypertensive and lipid-lowering therapy, and this improved adherence translated to reduced CV events. Taken together, these findings suggest that SPAA can play an important role in helping physicians improve the management of CV risk in their patients. OBJECTIVE: Large randomized clinical trials have shown the efficacy of aspirin, ACE (angiotensin converting enzyme) inhibitors and statins as secondary prevention measures in patients after an acute coronary syndrome with and without ST elevations. Therefore we aimed to determine the effect of a combination therapy with these three drugs on 1-year mortality after acute myocardial infarction (AMI). METHODS: We prospectively followed 9998 survivors of acute myocardial infarction treated with a beta-blocker for 1 year. Patients were divided into three groups according to their therapy with aspirin, ACE inhibitors and statins: 3 drugs, 2 drugs or 0-1 drug. RESULTS: The majority of patients (n = 6260, 62.6%) were treated with 3 drugs, 2986 (29.9%) with 2 drugs and 752 (7.5%) with 0-1 drug. In the univariate analysis 1-year mortality was 4.9%, 9.7% and 13.6%, respectively. After adjusting for confounding factors in the propensity score analysis the odds ratios for 1-year mortality were significantly increased with 0-1 drug (odds ratio 1.67, 95% CI 1.24-2.27) and with 2 drugs (odds ratio 1.54, 95% CI 1.26-1.87) in comparison with the group treated with all 3 drugs. However, in the ACOS registry the treatment was left to the discretion of the physician. This could lead to a selection bias, which cannot be fully eliminated by using multiple regression analysis. CONCLUSIONS: A combination therapy with aspirin, an ACE inhibitor and a statin reduces 1-year mortality in patients after AMI. Therefore a polypill approach with these three agents should be considered to increase drug compliance and reduce mortality after acute myocardial infarction. Background Significant gaps exist between guidelines-recommended therapies for cardiovascular disease prevention and current practice. Fixed-dose combination pills ('polypills') potentially improve adherence to therapy. This study is a preference study undertaken in conjunction with a clinical trial of a polypill and seeks to examine the underlying reasons for variations in treatment adherence to recommended therapy. Methods/design A preference study comprising: (1) Discrete Choice Experiment for patients; and (2) qualitative study of patients and providers. Both components will be conducted on participants in the trial. A joint model combining the observed adherence in the clinical trial (revealed preference) and the Discrete Choice Experiment data (stated preference) will be estimated. Estimates will be made of the marginal effect (importance) of each attribute on overall choice, the extent to which respondents are prepared to trade-off one attribute for another and predicted values of the level of adherence given a fixed set of attributes, and contextual and socio-demographic characteristics. For the qualitative study, a thematic analysis will be used as a means of exploring in depth the preferences and ultimately provide important narratives on the experiences and perspectives of individuals with regard to adherence behaviour. Ethics and dissemination Primary ethics approval was received from Sydney South West Area Health Service Human Research Ethics Committee (Royal Prince Alfred Hospital zone). In addition to usual scientific forums, the findings will be reported back to the communities involved in the studies through site-specific reports and oral presentations.

What is transvection?

An unusual feature of the Diptera is that homologous chromosomes are intimately synapsed in somatic cells. At a number of loci in Drosophila, this pairing can significantly influence gene expression. Such influences were first detected within the bithorax complex (BX-C) by E.B. Lewis, who coined the term transvection to describe them. Most cases of transvection involve the action of enhancers in trans. At several loci deletion of the promoter greatly increases this action in trans, suggesting that enhancers are normally tethered in cis by the promoter region. Transvection can also occur by the action of silencers in trans or by the spreading of position effect variegation from rearrangements having heterochromatic breakpoints to paired unrearranged chromosomes. Although not demonstrated, other cases of transvection may involve the production of joint RNAs by trans-splicing. Several cases of transvection require Zeste, a DNA-binding protein that is thought to facilitate homolog interactions by self-aggregation. Genes showing transvection can differ greatly in their response to pairing disruption. In several cases, transvection appears to require intimate synapsis of homologs. However, in at least one case (transvection of the iab-5,6,7 region of the BX-C), transvection is independent of synapsis within and surrounding the interacting gene. The latter example suggests that transvection could well occur in organisms that lack somatic pairing. In support of this, transvection-like phenomena have been described in a number of different organisms, including plants, fungi, and mammals.

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Pairing-dependent interallelic complementation was first described for the Ultrabithorax gene of the bithorax-complex in Drosophila by Lewis and cited as an example of a new phenomenon that Lewis called the "trans-vection effect." Several different kinds of pairing-dependent gene expression have been observed in Drosophila, and it is now clear that a variety of different molecular mechanisms probably underlie the changes in gene expression that are observed after disrupting chromosome pairing. Transvection in the bithorax-complex appears to result from the ability of cis-regulatory elements to regulate transcription of the promoter on the homologous chromosome. The same phenomenon appears to be responsible for pairing-dependent interallelic complementation at numerous other genes in Drosophila. Some transvection effects are dependent on the presence of wild-type or specific mutant forms of the protein encoded by the zeste trans-regulatory gene, but other transvection effects are zeste-independent. The ease with which chromosome aberrations can disrupt transvection also varies widely among different genes. Enhancers have been defined operationally as cis-regulatory sequences that can stimulate transcription of RNA polymerase-II-transcribed genes over large distances and even when located downstream of the gene. Recently, it has become evident that enhancers can also stimulate transcription in trans if they are brought into close proximity to the promoter/gene. These reports provide clues to the mechanism of remote enhancer action. In addition, the findings, together with genetic studies in Drosophila, strongly suggest that enhancer action in trans could underlie phenomena such as 'transvection', where one chromosome affects gene expression in the paired homolog. The zeste locus of Drosophila melanogaster encodes a DNA-binding protein that can influence transcription. A number of sites recognized by this protein fall within genes associated with transvection, a phenomenon suggesting a form of gene regulation that is responsive to the proximity of a gene to its homologous allele on another chromosome. These recent observations continue a history of studies concerning zeste and transvection which has inspired molecular models linking chromosome structure and positioning to the modulation of gene expression. Knowledge of fungal chromosome rearrangements comes primarily from N. crassa, but important information has also been obtained from A. nidulans and S. macrospora. Rearrangements have been identified in other Sordaria species and in Cochliobolus, Coprinus, Magnaporthe, Podospora, and Ustilago. In Neurospora, heterozygosity for most chromosome rearrangements is signaled by the appearance of unpigmented deficiency ascospores, with frequencies and ascus types that are characteristic of the type of rearrangement. Summary information is provided on each of 355 rearrangements analyzed in N. crassa. These include 262 reciprocal translocations, 31 insertional translocations, 27 quasiterminal translocations, 6 pericentric inversions, 1 intrachromosomal transposition, and numerous complex or cryptic rearrangements. Breakpoints are distributed more or less randomly among the seven chromosomes. Sixty of the rearrangements have readily detected mutant phenotypes, of which half are allelic with known genes. Constitutive mutations at certain positively regulated loci involve rearrangements having one breakpoint in an upstream regulatory region. Of 11 rearrangements that have one breakpoint in or near the NOR, most appear genetically to be terminal but are in fact physically reciprocal. Partial diploid strains can be obtained as recombinant progeny from crosses heterozygous for insertional or quasiterminal rearrangements. Duplications produced in this way precisely define segments that cover more than two thirds of the genome. Duplication-producing rearrangements have many uses, including precise genetic mapping by duplication coverage and alignment of physical and genetic maps. Typically, fertility is greatly reduced in crosses parented by a duplication strain. The finding that genes within the duplicated segment have undergone RIP mutation in some of the surviving progeny suggests that RIP may be responsible for the infertility. Meiotically generated recessive-lethal segmental deficiencies can be rescued in heterokaryons. New rearrangements are found in 10% or more of strains in which transforming DNA has been stably integrated. Electrophoretic separation of rearranged chromosomal DNAs has found useful applications. Synaptic adjustment occurs in inversion heterozygotes, leading progressively to nonhomologous association of synaptonemal complex lateral elements, transforming loop pairing into linear pairing. Transvection has been demonstrated in Neurospora. Beginnings have been made in constructing effective balancers. Experience has increased our understanding of several phenomena that may complicate analysis. With some rearrangements, nondisjunction of centromeres from reciprocal translocation quadrivalents results in 3:1 segregation and produces asci with four deficiency ascospores that occupy diagnostic positions in linear asci. Three-to-one segregation is most frequent when breakpoints are near centromeres. With some rearrangements, inviable deficiency ascospores become pigmented. Diagnosis must then depend on ascospore viability. In crosses between highly inbred strains, analysis may be handicapped by random ascospore abortion. This is minimized by using noninbred strains as testers. Numerous genes contain regulatory elements located many tens of kilobases away from the promoter they control. Specific mechanisms must be required to ensure that such distant elements can find and interact with their proper targets but not with extraneous genes. This review explores the connections between transvection phenomena, the activation of domains of homeotic gene expression, position effect variegation and silencers. These various examples of long-distance effects suggest that, in all cases, related forms of chromatin packaging may be involved.

What is the role of probiotics in gastrointestinal disease?

Probiotics are live, microbial food supplements that benefit the host animal by improving intestinal microbial balance. Across all 11 probiotic species and eight different gastrointestinal diseases - Irritable Bowel Syndrome (IBS), Helicobacter pylori infection (HPP), Necrotizing Enterocolitis (NEC), Pouchitis (Pouch), Antibiotic Associated diarrhea (AAD), Clostridium difficile Disease (CDD), Infectious diarrhea (ID), and Travellers diarrhea (TD) - probiotics have been shown to have effect on prevention and treatment of gastrointestinal disease through enhancing the immune response, protection against abnormal invasive bacteria. Probiotics have a role in all age groups, incl. infants.

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Gastrointestinal disease is a major cause of morbidity and mortality worldwide each year. Treatment of chronic inflammatory gastrointestinal conditions such as ulcerative colitis and Crohn's disease is difficult due to the ambiguity surrounding their precise aetiology. Infectious gastrointestinal diseases, such as various types of diarrheal disease are also becoming increasingly difficult to treat due to the increasing dissemination of antibiotic resistance among microorganisms and the emergence of the so-called 'superbugs'. Taking into consideration these problems, the need for novel therapeutics is essential. Although described for over a century probiotics have only been extensively researched in recent years. Their use in the treatment and prevention of disease, particularly gastrointestinal disease, has yielded many successful results, some of which we outline in this review. Although promising, many probiotics are hindered by inherent physiological and technological weaknesses and often the most clinically promising strains are unusable. Consequently we discuss various strategies whereby probiotics may be engineered to create designer probiotics. Such innovative approaches include; a receptor mimicry strategy to create probiotics that target specific pathogens and toxins, a patho-biotechnology approach using pathogen-derived genes to create more robust probiotic stains with increased host and processing-associated stress tolerance profiles and meta-biotechnology, whereby, functional metagenomics may be used to identify novel genes from diverse and vastly unexplored environments, such as the human gut, for use in biotechnology and medicine. Intestinal bacterial colonisation in pre-term infants is delayed compared with full-term infants, leading to an increased risk of gastrointestinal disease. Modulation of colonisation through dietary supplementation with probiotics or prebiotics could decrease such a risk. The present study evaluated clinical tolerance, the effects on gut microbiota, and inflammatory and immunological mucosal responses to an infant formula adapted for pre-term infants that included in its manufacturing process a fermentation step with two probiotic strains, Bifidobacterium breve C50 and Streptococcus thermophilus 065, inactivated by heat at the end of the process. A total of fifty-eight infants (gestational age: 30-35 weeks), fed either the fermented pre-term formula or a standard pre-term formula, were followed up during their hospital stay. Clinical tolerance, faecal microbiota using a culture and a culture-independent method (temporal temperature gel electrophoresis), faecal calprotectin and secretory IgA were analysed weekly. No difference was observed regarding anthropometric data and digestive tolerance, except for abdominal distension, the incidence of which was lower in infants fed the fermented formula for 2 weeks. Bacterial colonisation was not modified by the type of feeding, particularly for bifidobacteria. Faecal calprotectin was significantly lower in infants fed the fermented formula for 2 weeks, and secretory IgA increased with both mother's milk and the fermented formula. The fermented formula was well tolerated and did not significantly modulate the bacterial colonisation but had benefits on inflammatory and immune markers, which might be related to some features of gastrointestinal tolerance. GOALS: The objective of this study was to determine how gastroenterologists perceive and use probiotic-based therapies in practice. BACKGROUND: In the United States, there has been a recent increase in research investigating the therapeutic capacities of probiotics in human disease and an accompanying increase in product availability and marketing. How medical care providers have interpreted the available literature and incorporated it into their practice has not been earlier assessed. STUDY: A 16-question survey (see Survey, Supplemental Digital Content 1, http://links.lww.com/JCG/A14) was distributed to practicing gastroenterologists and physicians with a specific interest in GI disorders within a large metropolitan area. RESULTS: All physicians responded that they believed probiotics to be safe for most patients and 98% responded that probiotics have a role in treating gastrointestinal illnesses or symptoms. Currently 93% of physicians have patients taking probiotics most often for irritable bowel syndrome. Commonly used probiotics included yogurt-based products, Bifidobacterium infantis 35624 (Align), and VSL#3. Most surveyed physicians recommended probiotics for irritable bowel syndrome, antibiotic, and Clostridium difficile-associated diarrhea because they believed that the literature supports their usage for these conditions. However, physician practice patterns did not consistently correlate with published, expert-panel-generated recommendations for evidence-based probiotic use. CONCLUSIONS: This study suggests most gastrointestinal disease specialists recognize a role for and have used probiotics as part of their therapeutic armamentarium; however, the effective implementation of this practice will benefit from additional supporting studies and the eventual development of clinical practice guidelines supported by the major gastroenterology societies. Our intestinal microbiota serve many roles vital to the normal daily function of the human gastrointestinal tract. Many probiotics are derived from our intestinal bacteria, and have been shown to provide clinical benefit in a variety of gastrointestinal conditions. Current evidence indicates that probiotic effects are strain-specific, they do not act through the same mechanisms, and nor are all probiotics indicated for the same health conditions. However, they do share several common features in that they exert anti-inflammatory effects, they employ different strategies to antagonize competing microorganisms, and they induce cytoprotective changes in the host either through enhancement of barrier function, or through the upregulation of cytoprotective host proteins. In this review we focus on a few selected probiotics - a bacterial mixture (VSL#3), a Gram-negative probiotic (E. coli Nissle 1917), two Gram-positive probiotic bacteria (LGG, L. reuteri), and a yeast probiotic (S. boulardii) - for which sound clinical and mechanistic data is available. Safety of probiotic formulations is also discussed. OBJECTIVES: Probiotics may be useful in preventing acute infectious diarrhea. Bifidobacteria are particularly attractive as probiotics agent because they constitute the predominant colonic flora of breastfed infants and are thought to play a role in the decreased incidence of diarrhea in breastfed infants. METHODS: This was a multicenter, double-blind, controlled study to evaluate the efficacy of a milk formula supplemented with viable Bifidobacterium lactis strain Bb 12 (BbF) in the prevention of acute diarrhea in infants younger than 8 months living in residential nurseries or foster care centers. RESULTS: Ninety healthy children received either the BbF or a conventional formula (CF) daily. The mean duration of the stay in the residential center was similar (137 v 148 days). At enrollment, there were no differences between the two groups with respect to age (3.7 +/- 2.1 months), gender, anthropometric data, history of allergy or gastrointestinal disease, frequency of breast-feeding in the neonatal period or timing of introduction of solid food. Altogether, 28.3% of the BbF infants had diarrhea during the study compared with 38.7% of controls (NS). There was a statistically insignificant trend for shorter episodes of diarrhea in the BbF group (5.1 +/- 3.3 days v 7 +/- 5.5 days, NS). The number of days with diarrhea was 1.15 +/- 2.5 in the BbF group with a daily probability of diarrhea of 0.84 versus 2.3 +/- 4.5 days and 1.55, respectively, in the CF group (P = 0.0002 and 0.0014). Feeding infants with the BbF reduced their risk of getting diarrhea by a factor of 1.9 (range, 1.33-2.6). Analysis of the cumulative incidence of diarrheal episodes showed a trend that the first onset of diarrhea occurred later in the BbF group. CONCLUSION: These results provide some evidence that viable Bifidobacterium lactis strain Bb 12, added to an acidified infant formula, has some protective effect against acute diarrhea in healthy children. Probiotics are live, microbial food supplements that benefit the host animal by improving intestinal microbial balance. Their major role in preventing and treating gastrointestinal disease appears to be from their effect on the immune process, protection against abnormal invasive bacteria, and in the production of short-chain fatty acids from starch and non-starch polysaccharides. Probiotic microorganisms are administered in food supplements and yogurts. They are also now sold in the form of capsules and powders. There is great variation in the microorganisms in the various supplements. It is important to understand that all probiotic products are different. Some contain a single organism and others contain multiple organisms. Therapeutic results have been achieved with various probiotics in different diseases. In the treatment of inflammatory bowel diseases (IBD), success has been reported with Escherichia coli Nissle strain in ulcerative colitis, and with a multiple organism product, VSL#3 (VSL Pharmaceuticals, Fort Lauderdale, FL), in Crohn's disease and pouchitis. Initial reports in irritable bowel syndrome (IBS) have resulted in encouraging results with the use of E. coli Nissle strain, and recently with multiple organism probiotic supplements. However, caution must still apply to the use of probiotics in IBD and IBS because the reports and the number of patients treated are limited.