context
stringlengths 5
6.31k
⌀ | question
stringlengths 13
640
| answer
stringlengths 4
2.42k
⌀ |
---|---|---|
Earlier work demonstrated that the transcription factor C/EBPα can convert immature and mature murine B lineage cells into functional macrophages. Testing >20 human lymphoma and leukemia B cell lines, we found that most can be transdifferentiated at least partially into macrophage-like cells, provided that C/EBPα is expressed at sufficiently high levels. A tamoxifen-inducible subclone of the Seraphina Burkitt lymphoma line, expressing C/EBPαER, could be efficiently converted into phagocytic and quiescent cells with a transcriptome resembling normal macrophages. The converted cells retained their phenotype even when C/EBPα was inactivated, a hallmark of cell reprogramming. Interestingly, C/EBPα induction also impaired the cells' tumorigenicity. Likewise, C/EBPα efficiently converted a lymphoblastic leukemia B cell line into macrophage-like cells, again dramatically impairing their tumorigenicity. Our experiments show that human cancer cells can be induced by C/EBPα to transdifferentiate into seemingly normal cells at high frequencies and provide a proof of principle for a potential new therapeutic strategy for treating B cell malignancies.
|
How can B-cells transdifferentiate into macrophages?
|
Earlier work demonstrated that the transcription factor C/EBPα can convert immature and mature murine B lineage cells into functional macrophages.
|
X inactivation, the transcriptional silencing of one of the two X chromosomes in female mammals, achieves dosage compensation of X-linked genes relative to XY males. In eutherian mammals X inactivation is regulated by the X-inactive specific transcript (Xist), a cis-acting non-coding RNA that triggers silencing of the chromosome from which it is transcribed. Marsupial mammals also undergo X inactivation but the mechanism is relatively poorly understood. We set out to analyse the X chromosome in Monodelphis domestica and Didelphis virginiana, focusing on characterizing the interval defined by the Chic1 and Slc16a2 genes that in eutherians flank the Xist locus. The synteny of this region is retained on chicken chromosome 4 where other loci belonging to the evolutionarily ancient stratum of the human X chromosome, the so-called X conserved region (XCR), are also located. We show that in both M. domestica and D. virginiana an evolutionary breakpoint has separated the Chic1 and Slc16a2 loci. Detailed analysis of opossum genomic sequences revealed linkage of Chic1 with the Lnx3 gene, recently proposed to be the evolutionary precursor of Xist, and Fip1, the evolutionary precursor of Tsx, a gene located immediately downstream of Xist in eutherians. We discuss these findings in relation to the evolution of Xist and X inactivation in mammals.
|
The X-inactive specific transcript (Xist) gene is responsible for mediating the X-chromosome inactivation in females, where one X-chromosome is silenced and transcriptionally inactivated. What does Xist encode?
|
In eutherian mammals X inactivation is regulated by the X-inactive specific transcript (Xist), a cis-acting non-coding RNA that triggers silencing of the chromosome from which it is transcribed.
|
Purpose The aim of this study was to determine the occurrence and distribution of the 'central vein' sign in white matter lesions on susceptibility-weighted magnetic resonance images in patients with multiple sclerosis (MS) and cerebral small vessel disease (CSVD). Materials and methods T2-weighted and fluid-attenuated inversion recovery magnetic resonance images of 19 MS patients and 19 patients affected by CSVD were analysed for the presence and localisation of focal hyperintense white matter lesions. Lesions were subdivided into periventricular or non-periventricular (juxtacortical, subcortical, deep white matter and cerebellar) distributed. The number and localisation of lesions presenting with the central vein sign were recorded and compared between MS and CSVD lesions. Results A total of 313 MS patients and 75 CSVD lesions were identified on T2-weighted and fluid-attenuated inversion recovery magnetic resonance images. The central vein sign was found in 128 MS lesions (40.9%), and the majority of them (71/128, 55.5%) had a periventricular distribution. The central vein sign was found in 22 out of 75 (29.3%) CSVD lesions, and periventricular distribution was seen in six out of 22 (27.2%) CSVD lesions. The difference in the proportion of white matter hyperintense lesions that presented with the central vein sign on susceptibility-weighted images in patients with MS and CSVD was statistically different, and a significantly higher number of MS patients presented with lesions with the central vein sign compared to CSVD patients. Conclusion The presence of the central vein sign on susceptibility-weighted images for MS lesions improves the understanding of the periventricular distribution of MS lesions and could contribute as adjunctive diagnostic criteria for MS disease.
|
Central Vein Sign is characteristic to which disease?
|
Conclusion The presence of the central vein sign on susceptibility-weighted images for MS lesions improves the understanding of the periventricular distribution of MS lesions and could contribute as adjunctive diagnostic criteria for MS disease.
|
A novel method is developed to model and predict the transmembrane regions of beta-barrel membrane proteins. It is based on a Hidden Markov model (HMM) with architecture obeying those proteins' construction principles. The HMM is trained and tested on a non-redundant set of 11 beta-barrel membrane proteins known to date at atomic resolution with a jack-knife procedure. As a result, the method correctly locates 97% of 172 transmembrane beta-strands. Out of the 11 proteins, the barrel size for ten proteins and the overall topology for seven proteins are correctly predicted. Additionally, it successfully assigns the entire topology for two new beta-barrel membrane proteins that have no significant sequence homology to the 11 proteins. Predicted topology for two candidates for beta-barrel structure of the outer mitochondrial membrane is also presented in the paper.
|
What are the computational methods for the prediction of beta-barrel transmembrane proteins?
|
A novel method is developed to model and predict the transmembrane regions of beta-barrel membrane proteins. It is based on a Hidden Markov model (HMM) with architecture obeying those proteins' construction principles.
|
Necroptosis is a programmed cell death pathway triggered by activation of receptor interacting protein kinase 3 (RIPK3), which phosphorylates and activates the mixed lineage kinase-like domain pseudokinase, MLKL, to rupture or permeabilize the plasma membrane. Necroptosis is an inflammatory pathway associated with multiple pathologies including autoimmunity, infectious and cardiovascular diseases, stroke, neurodegeneration, and cancer. Here, we describe protocols that can be used to characterize MLKL as the executioner of plasma membrane rupture in necroptosis. We visualize the process of necroptosis in cells using live-cell imaging with conventional and confocal fluorescence microscopy, and in fixed cells using electron microscopy, which together revealed the redistribution of MLKL from the cytosol to the plasma membrane prior to induction of large holes in the plasma membrane. We present in vitro nuclear magnetic resonance (NMR) analysis using lipids to identify putative modulators of MLKL-mediated necroptosis. Based on this method, we identified quantitative lipid-binding preferences and phosphatidyl-inositol phosphates (PIPs) as critical binders of MLKL that are required for plasma membrane targeting and permeabilization in necroptosis.
|
Do cells undergoing necroptosis show disruption of their cell membranes?
|
Necroptosis is a programmed cell death pathway triggered by activation of receptor interacting protein kinase 3 (RIPK3), which phosphorylates and activates the mixed lineage kinase-like domain pseudokinase, MLKL, to rupture or permeabilize the plasma membrane.
|
Analysis of serum and plasma proteomes is a common approach for biomarker discovery, and the removal of high-abundant proteins, such as albumin and immunoglobins, is usually the first step in the analysis. However, albumin binds peptides and proteins, which raises concerns as to how the removal of albumin could impact the outcome of the biomarker study while ignoring the possibility that this could be a biomarker subproteome itself. The first goal of this study was to test a new commercially available affinity capture reagent from Protea Biosciences and to compare the efficiency and reproducibility to four other commercially available albumin depletion methods. The second goal of this study was to determine if there is a highly efficient albumin depletion/isolation system that minimizes sample handling and would be suitable for large numbers of samples. Two of the methods tested (Sigma and ProteaPrep) showed an albumin depletion efficiency of 97% or greater for both serum and cerebrospinal fluid (CSF). Isolated serum and CSF albuminomes from ProteaPrep spin columns were analyzed directly by LC-MS/MS, identifying 128 serum (45 not previously reported) and 94 CSF albuminome proteins (17 unique to the CSF albuminome). Serum albuminome was also isolated using Vivapure anti-HSA columns for comparison, identifying 105 proteins, 81 of which overlapped with the ProteaPrep method.
|
Albumin depletion is a common first step for proteomic analysis of CSF fluid. What is the advantage and disadvantage of this procedure?
|
However, albumin binds peptides and proteins, which raises concerns as to how the removal of albumin could impact the outcome of the biomarker study while ignoring the possibility that this could be a biomarker subproteome itself.
|
During mammalian oocyte maturation, protein synthesis is mainly controlled through cytoplasmic polyadenylation of stored maternal mRNAs. In this study, the role of polyadenylation modification of maternal transcripts in pig oocytes was investigated by adding cordycepin (3'-dA), a potent polyadenylation inhibitor, to the culture medium of porcine oocytes maturing in vitro. 3'-dA significantly prevented cumulus expansion regardless of the concentration used, and inhibited pig oocyte maturation in a dose-dependent manner. Further, 3'-dA 1 microg/ml-treated MII oocytes experienced significantly lower rates of cleavage (29%) and blastocyst formation (15.35%) compared to control MII oocytes (58.6% and 35.3%, respectively). Western blotting revealed that the activity of mitogen-activated protein kinase (MAPK) and p34(cdc2) was significantly decreased in oocytes and cumulus cells treated with 3'-dA at a concentration of 1 microg/ml or greater. To further explore the underlying molecular mechanisms, expression patterns and polyadenylation states of four important genes, C-mos, cyclin B, GDF9 and BMP15, were studied as representative maternal transcripts by real-time PCR and the PAT assay. 3'-dA at concentrations above 1 microg/ml significantly prevented polyadenylation and caused aberrant expression of C-mos and GDF9 during oocyte maturation. These results suggest that polyadenylation inhibitor blocked pig oocyte maturation in vitro by one or more of the following actions: (1) inactivation of MAPK and MPF in oocytes, especially at the late stages (MI and MII); (2) prevention of cumulus cell expansion through inactivation of cellular MAPK; and (3) inhibition of the maternal mRNA polyadenylation process, which in reverse, disrupted the maternal mRNA patterns in pig oocytes' maturation in vitro.
|
Is polyadenylation a process that stabilizes a protein by adding a string of Adenosine residues to the end of the molecule?
|
During mammalian oocyte maturation, protein synthesis is mainly controlled through cytoplasmic polyadenylation of stored maternal mRNAs.
|
Förster resonance energy transfer (FRET) is a powerful tool in biological research and has been widely used in the study of biomolecular interactions. SUMOylation is an important post-translational modification that is involved in many key biological processes. As a multi-step cascade reaction, SUMOylation involves multiple enzymes and protein-protein interactions. Here, we report the development of an in vitro FRET-based high-throughput screening (HTS) assay in SUMOylation. This assay is based on steady state and high efficiency of the fluorescent energy transfer between CyPet and YPet fused to SUMO1 and Ubc9, respectively. We optimized the assay and performed a small-scale pilot study to validate the screening platform. Carried out in 384-well plate format, our FRET-based HTS provides a powerful tool for large-scale and high-throughput applications.
|
Is SUMOylation a post-translational modification in eukaryotes?
|
SUMOylation is an important post-translational modification that is involved in many key biological processes
|
Septins are important components of the cytoskeleton that are highly conserved in eukaryotes and play major roles in cytokinesis, patterning, and many developmental processes. Septins form heteropolymers which assemble into higher-order structures including rings, filaments, and gauzes. In contrast to actin filaments and microtubules, the molecular mechanism by which septins assemble is not well-understood. Here, we report that in the filamentous fungus Aspergillus nidulans, four core septins form heteropolymeric complexes. AspE, a fifth septin lacking in unicellular yeasts, interacts with only one of the core septins, and only during multicellular growth. AspE is required for proper localization of three of the core septins, and requires this same subset of core septins for its own unique cortical localization. The ΔaspE mutant lacks developmentally-specific septin higher-order structures and shows reduced spore production and slow growth with low temperatures and osmotic stress. Our results show that at least two distinct septin heteropolymer populations co-exist in A. nidulans, and that while AspE is not a subunit of either heteropolymer, it is required for assembly of septin higher-order structures found in multicellular development.
|
What are Septins?
|
Septins are important components of the cytoskeleton that are highly conserved in eukaryotes and play major roles in cytokinesis, patterning, and many developmental processes.
|
The objective of this open single-centre study was to evaluate the efficacy and tolerability of botulinum toxin type-A (BTX-A) as add-on in the prophylactic treatment of cluster headache (CH). Twelve male patients with episodic (n=3) or chronic (n=9) CH, unresponsive to common prophylactic medications, were treated with a cumulative dose of 50 International Units (IU) BTX-A according to a standardised injection scheme into the ipsilateral pericranial muscles. One patient with chronic CH experienced a total cessation of attacks and in 2 patients attack intensity and frequency improved. In another patient with chronic CH typical attacks were not influenced, but an ipsilateral continuous occipital headache significantly improved. Patients with episodic CH did not benefit from BTX-A treatment. Tolerability was excellent. These findings provide evidence that BTX-A may be beneficial as an add-on prophylactic therapy for a limited number of patients with chronic CH.
|
What pharmacological and non-pharmacological interventions can be considered as prophylactic therapies in Cluster Headache patients?
|
The objective of this open single-centre study was to evaluate the efficacy and tolerability of botulinum toxin type-A (BTX-A) as add-on in the prophylactic treatment of cluster headache (CH).
|
Interphase chromatin is organized into topologically associating domains (TADs). Within TADs, chromatin looping interactions are formed between DNA regulatory elements, but their functional importance for the establishment of the 3D genome organization and gene regulation during development is unclear. Using high-resolution Hi-C experiments, we analyze higher order 3D chromatin organization during Drosophila embryogenesis and identify active and repressive chromatin loops that are established with different kinetics and depend on distinct factors: Zelda-dependent active loops are formed before the midblastula transition between transcribed genes over long distances. Repressive loops within polycomb domains are formed after the midblastula transition between polycomb response elements by the action of GAGA factor and polycomb proteins. Perturbation of PRE function by CRISPR/Cas9 genome engineering affects polycomb domain formation and destabilizes polycomb-mediated silencing. Preventing loop formation without removal of polycomb components also decreases silencing efficiency, suggesting that chromatin architecture can play instructive roles in gene regulation during development. VIDEO ABSTRACT.
|
Do polycomb group proteins (PcG) mediate the formation of chromatin loops?
|
Repressive loops within polycomb domains are formed after the midblastula transition between polycomb response elements by the action of GAGA factor and polycomb proteins.
|
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'.
|
Are ultraconserved elements often transcribed?
|
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
|
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 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.
|
We present a study on computational identification of uber-operons in a prokaryotic genome, each of which represents a group of operons that are evolutionarily or functionally associated through operons in other (reference) genomes. Uber-operons represent a rich set of footprints of operon evolution, whose full utilization could lead to new and more powerful tools for elucidation of biological pathways and networks than what operons have provided, and a better understanding of prokaryotic genome structures and evolution. Our prediction algorithm predicts uber-operons through identifying groups of functionally or transcriptionally related operons, whose gene sets are conserved across the target and multiple reference genomes. Using this algorithm, we have predicted uber-operons for each of a group of 91 genomes, using the other 90 genomes as references. In particular, we predicted 158 uber-operons in Escherichia coli K12 covering 1830 genes, and found that many of the uber-operons correspond to parts of known regulons or biological pathways or are involved in highly related biological processes based on their Gene Ontology (GO) assignments. For some of the predicted uber-operons that are not parts of known regulons or pathways, our analyses indicate that their genes are highly likely to work together in the same biological processes, suggesting the possibility of new regulons and pathways. We believe that our uber-operon prediction provides a highly useful capability and a rich information source for elucidation of complex biological processes, such as pathways in microbes. All the prediction results are available at our Uber-Operon Database: http://csbl.bmb.uga.edu/uber, the first of its kind.
|
What are the uber-operons?
|
Uber-operons represent a rich set of footprints of operon evolution, whose full utilization could lead to new and more powerful tools for elucidation of biological pathways and networks than what operons have provided, and a better understanding of prokaryotic genome structures and evolution
|
We report on a male newborn with multiple congenital abnormalities consistent with the diagnosis of VACTERL association (vertebral, anal, cardiac, tracheo-esophageal fistula, renal, and limb anomalies), who had Fanconi anemia (complementation group B) recognized by the detection of a deletion in chromosome Xp22.2 using an oligonucleotide array. The diagnosis of Fanconi anemia was confirmed by increased chromosomal breakage abnormalities observed in cultured cells that were treated with cross-linking agents. This is the first report in the literature of Fanconi anemia complementation group B detected by oligonucleotide array testing postnatally.
|
What is considered a reliable technique for the definitive cytogenetic diagnosis of Fanconi anemia homozygosity?
|
The diagnosis of Fanconi anemia was confirmed by increased chromosomal breakage abnormalities observed in cultured cells that were treated with cross-linking agents.
|
X chromosome inactivation (XCI) depends on a noncoding sense-antisense transcript pair, Xist and Tsix. At the onset of XCI, Xist RNA accumulates on one of two Xs, coating and silencing the chromosome in cis. The molecular basis for monoallelic Xist upregulation is not known, though evidence predominantly supports a posttranscriptional mechanism through RNA stabilization. Here, we test whether Tsix RNA destabilizes Xist RNA. Unexpectedly, we find that Xist upregulation is not based on transcript stabilization at all but is instead controlled by transcription in a sex-specific manner. Tsix directly regulates its transcription. On the future inactive X, Tsix downregulation induces a transient heterochromatic state in Xist, followed paradoxically by high-level Xist expression. A Tsix-deficient X chromosome adopts the heterochromatic state in pre-XCI cells. This state persists through XCI establishment and "reverts" to a euchromatic state during XCI maintenance. We have therefore identified chromatin marks that preempt and predict asymmetric Xist expression.
|
Which is the transcript responsible for X-chromosome inactivation?
|
chromosome inactivation (XCI) depends on a noncoding sense-antisense transcript pair, Xist
|
The University of California Santa Cruz (UCSC) Genome Browser Database is an up to date source for genome sequence data integrated with a large collection of related annotations. The database is optimized to support fast interactive performance with the web-based UCSC Genome Browser, a tool built on top of the database for rapid visualization and querying of the data at many levels. The annotations for a given genome are displayed in the browser as a series of tracks aligned with the genomic sequence. Sequence data and annotations may also be viewed in a text-based tabular format or downloaded as tab-delimited flat files. The Genome Browser Database, browsing tools and downloadable data files can all be found on the UCSC Genome Bioinformatics website (http://genome.ucsc.edu), which also contains links to documentation and related technical information.
|
Which algorithm is used by the UCSC Genome Browser?
|
The database is optimized to support fast interactive performance with the web-based UCSC Genome Browser, a tool built on top of the database for rapid visualization and querying of the data at many levels. The annotations for a given genome are displayed in the browser as a series of tracks aligned with the genomic sequence. Sequence data and annotations may also be viewed in a text-based tabular format or downloaded as tab-delimited flat files.
|
Severe hypertriglyceridaemia is associated with pancreatitis and chronic pancreatitis-induced diabetes. Familial chylomicronaemia syndrome (FCS) is a rare autosomal recessive disorder of lipid metabolism characterised by high levels of triglycerides (TGs) due to failure of chylomicron clearance. It causes repeated episodes of severe abdominal pain, fatigue and attacks of acute pancreatitis. There are few current options for its long-term management. The only universal long-term therapy is restriction of total dietary fat intake to <10-15% of daily calories (15 to 20g per day). Many patients have been treated with fibrates and statins with a variable response, but many remain susceptible to pancreatitis. Other genetic syndromes associated with hypertriglyceridaemia include familial partial lipodystrophy (FPLD). Targeting apolipoprotein C3 (apoC3) offers the ability to increase clearance of chylomicrons and other triglyceride-rich lipoproteins. Volanesorsen is an antisense oligonucleotide (ASO) inhibitor of apoC3, which reduces TG levels by 70-80% which has been shown also to reduce rates of pancreatitis and improve well-being in FCS and reduce TGs and improve insulin resistance in FPLD. It is now undergoing licensing and payer reviews. Further developments of antisense technology including small interfering RNA therapy to apoC3 as well as other approaches to modulating triglycerides are in development for this rare disorder.
|
What is the target of Volanesorsen?
|
Volanesorsen is an antisense oligonucleotide (ASO) inhibitor of apoC3, which reduces TG levels by 70-80% which has been shown also to reduce rates of pancreatitis and improve well-being in FCS and reduce TGs and improve insulin resistance in FPLD.
|
Indocyanine green (ICG), a US Food and Drug Administration-approved fluorescent compound, has been on the medical stage for more than 60 years. Current uses include hepatic function evaluation before surgical procedure and fundus evaluation. The large safety margin and near-infrared fluorescent optical advantage of the drug have proved useful in several clinical trials of intraoperative systems for tumor removal. Several nanoparticle-sized formulations for thermal ablation and photodynamic therapy have also been evaluated in animal experiments. Studies have attempted to manipulate ICG as a reporter fluorophore with initial success. In this article, we reviewed ICG's histological applications, chemical and physical properties, current clinical applications, ongoing clinical trials, and biomedical studies and prospects. We believe that ICG could be used with novel biotechnological techniques, such as fluorescent endoscopy and photoacoustic equipment, in a range of biomedical fields.
|
How is Indocyanine green (ICG) used?
|
Indocyanine green (ICG), a US Food and Drug Administration-approved fluorescent compound, has been on the medical stage for more than 60 years. Current uses include hepatic function evaluation before surgical procedure and fundus evaluation.
|
We compared the safety and efficacy of siltuximab (S), an anti-interleukin-6 chimeric monoclonal antibody, plus bortezomib (B) with placebo (plc) + B in patients with relapsed/refractory multiple myeloma in a randomized phase 2 study. Siltuximab was given by 6 mg/kg IV every 2 weeks. On progression, B was discontinued and high-dose dexamethasone could be added to S/plc. Response and progression-free survival (PFS) were analyzed pre-dexamethasone by European Group for Blood and Marrow Transplantation (EBMT) criteria. For the 281 randomized patients, median PFS for S + B and plc + B was 8.0 and 7.6 months (HR 0.869, P = 0.345), overall response rate was 55 versus 47% (P = 0.213), complete response rate was 11 versus 7%, and median overall survival (OS) was 30.8 versus 36.8 months (HR 1.353, P = 0.103). Sustained suppression of C-reactive protein, a marker reflective of inhibition of interleukin-6 activity, was seen with S + B. Siltuximab did not affect B pharmacokinetics. Siltuximab/placebo discontinuation (75 versus 66%), grade ≥3 neutropenia (49 versus 29%), thrombocytopenia (48 versus 34%), and all-grade infections (62 versus 49%) occurred more frequently with S + B. The addition of siltuximab to bortezomib did not appear to improve PFS or OS despite a numerical increase in response rate in patients with relapsed or refractory multiple myeloma.
|
Which interleukin is blocked by Siltuximab?
|
We compared the safety and efficacy of siltuximab (S), an anti-interleukin-6 chimeric monoclonal antibody, plus bortezomib (B) with placebo (plc) + B in patients with relapsed/refractory multiple myeloma in a randomized phase 2 study.
|
The enormous genetic variability reported in HIV-1 has posed problems in the treatment of infected individuals. This is evident in the form of HIV-1 resistant to antiviral agents, neutralizing antibodies and cytotoxic T lymphocytes (CTLs) involving multiple viral gene products. Based on this, it has been suggested that a comprehensive analysis of the polymorphisms in HIV proteins is of value for understanding the virus transmission and pathogenesis as well as for the efforts towards developing anti-viral therapeutics and vaccines. This study, for the first time, describes an in-depth analysis of genetic variation in Vpr using information from global HIV-1 isolates involving a total of 976 Vpr sequences. The polymorphisms at the individual amino acid level were analyzed. The residues 9, 33, 39, and 47 showed a single variant amino acid compared to other residues. There are several amino acids which are highly polymorphic. The residues that show ten or more variant amino acids are 15, 16, 28, 36, 37, 48, 55, 58, 59, 77, 84, 86, 89, and 93. Further, the variant amino acids noted at residues 60, 61, 34, 71 and 72 are identical. Interestingly, the frequency of the variant amino acids was found to be low for most residues. Vpr is known to contain multiple CTL epitopes like protease, reverse transcriptase, Env, and Gag proteins of HIV-1. Based on this, we have also extended our analysis of the amino acid polymorphisms to the experimentally defined and predicted CTL epitopes. The results suggest that amino acid polymorphisms may contribute to the immune escape of the virus. The available data on naturally occurring polymorphisms will be useful to assess their potential effect on the structural and functional constraints of Vpr and also on the fitness of HIV-1 for replication.
|
How is the sequence variability defined in antibodies?
|
This study, for the first time, describes an in-depth analysis of genetic variation in Vpr using information from global HIV-1 isolates involving a total of 976 Vpr sequences
|
Cystic fibrosis is the most common hereditary disease in populations of European descent, with its prevalence depending on the populations and ethnic groups studied. In contrast to Europe and North America, there is little information about this disease in Latin America. Uruguay currently has a human population of 3,000,000, with a low rate of miscegenation and no remaining isolated Amerindian groups. In the present study, we estimated the prevalence of cystic fibrosis in this country based on the detection of DeltaF508 mutation carriers in 500 unrelated individuals and on the frequency of individuals homozygous for this mutation within the affected population. The latter was calculated from the frequency of the different mutations and genotypes observed in a sample of 52 previously described patients with confirmed cystic fibrosis. A theoretical estimate of the prevalence of cystic fibrosis based on anthropological data suggested a frequency of 25 affected individuals/100,000 inhabitants. However, our data indicated that the true prevalence in the population was considerably lower (6.9 cases/100,000 inhabitants).
|
Which is the prevalence of cystic fibrosis in the human population?
|
A theoretical estimate of the prevalence of cystic fibrosis based on anthropological data suggested a frequency of 25 affected individuals/100,000 inhabitants. However, our data indicated that the true prevalence in the population was considerably lower (6.9 cases/100,000 inhabitants)
|
Recently, unique areas of transcriptional regulation termed super-enhancers have been identified and implicated in human disease. Defined by their magnitude of size, transcription factor density, and binding of transcriptional machinery, super-enhancers have been associated with genes driving cell differentiation. While their functions are not completely understood, it is clear that these regions driving high-level transcription are susceptible to perturbation, and trait-associated single nucleotide polymorphisms (SNPs) occur within super-enhancers of disease-relevant cell types. Here we review evidence for super-enhancer involvement in cancers, complex diseases, and developmental disorders and discuss interactions between super-enhancers and cofactors/chromatin regulators.
|
What are the properties of super-enhancers?
|
Here we review evidence for super-enhancer involvement in cancers, complex diseases, and developmental disorders and discuss interactions between super-enhancers and cofactors/chromatin regulators.
|
Erythropoiesis requires large amounts of iron for hemoglobin synthesis, which is mainly provided by macrophages and the intestines in a transferrin (Tf)-bound form. Bone marrow erythroblasts incorporate Tf through endocytosis, which is mediated by transferrin receptor 1 (TFR1). Recently, human TFR1, aside from its role as a Tf receptor, was also found to be a receptor for the H-subunit of ferritin (FTH). In humans, hematopoietic erythroid precursor cells express high levels of TFR1 and specifically take up the FTH homopolymer (H-ferritin). H-ferritin inhibits the formation of burst forming unit-erythroid colonies in vitro. TFR2, which is also a Tf receptor, is predominantly expressed in hepatocytes and erythroid precursor cells. In the liver, TFR2 forms a complex with HFE, a hereditary hemochromatosis-associated protein, and acts as an iron sensor. In mice, hepatocyte-specific knockout of the TFR2 gene has been shown to cause systemic iron-overload with decreased expression of hepcidin, the central regulator of iron homeostasis. In erythroid cells, TFR2 forms a complex with the erythropoietin receptor and facilitates its trafficking to the cell membrane. Moreover, hematopoietic cell-specific knockout of the TFR2 gene causes microcytic erythrocytosis in mice. This review focuses on the molecular evolution and functions of these TFRs and their ligands.
|
Is the TFR1 gene dispensable for erythropoiesis?
|
In humans, hematopoietic erythroid precursor cells express high levels of TFR1 and specifically take up the FTH homopolymer (H-ferritin).
|
Prostate cancer is the leading cause of cancer-related deaths in men. Androgen ablation is the mainstay of treatment for advanced prostate cancer. This therapy is very effective in androgen-dependent cancer; however, these cancers eventually become androgen independent, rendering anti-androgen therapy ineffective. The exploration of novel modalities of treatment is therefore essential to improve the prognosis of this neoplasia. Telomeres are specialized heterochromatin structures that act as protective caps at the ends of chromosomes. Telomere maintenance in the majority of tumor cells is achieved by telomerase, a reverse transcriptase enzyme that catalyzes the synthesis of further telomeric DNA. Telomerase is detected in the majority of prostate cancers, but not in normal or benign prostatic hyperplasia tissue. Moreover, the human telomerase reverse transcriptase (hTERT) gene, the catalytic subunit of telomerase, is regulated by androgens as well as by different oncogenes including Her-2, Ras, c-Myc and Bcl-2, which seem to play an important role in prostate cancer progression. Thus, telomerase may represent a very good candidate for targeted therapy in prostate tumors. To inhibit telomere maintenance by telomerase, approaches that directly target either telomerase and telomeres or the telomerase regulatory mechanisms have been used. Moreover, strategies targeting telomerase-positive cells as a means to directly kill the tumor cells have been tested. This review summarizes the most promising results achieved by anti-telomerase strategy in different solid tumors. Most of the telomerase-associated therapies described here have proved very promising for the treatment of prostate cancer. On the basis of the good results obtained and considering the multigenic defects of human tumors, including prostate cancer, the combination of anti-telomerase strategies with conventional drugs and/or molecules capable of interfering with oncogenic pathways could efficiently improve the response of this neoplasia.
|
What makes telomerase a good drug target?
|
Telomerase is detected in the majority of prostate cancers, but not in normal or benign prostatic hyperplasia tissue.
|
Mutations in dynamin 2 (DNM2) lead to dominant intermediate Charcot-Marie-Tooth neuropathy type B, while a different set of DNM2 mutations cause autosomal dominant centronuclear myopathy. In this study, we aimed to elucidate the disease mechanisms in dominant intermediate Charcot-Marie-Tooth neuropathy type B and to find explanations for the tissue-specific defects that are associated with different DNM2 mutations in dominant intermediate Charcot-Marie-Tooth neuropathy type B versus autosomal dominant centronuclear myopathy. We used tissue derived from Dnm2-deficient mice to establish an appropriate peripheral nerve model and found that dominant intermediate Charcot-Marie-Tooth neuropathy type B-associated dynamin 2 mutants, but not autosomal dominant centronuclear myopathy mutants, impaired myelination. In contrast to autosomal dominant centronuclear myopathy mutants, Schwann cells and neurons from the peripheral nervous system expressing dominant intermediate Charcot-Marie-Tooth neuropathy mutants showed defects in clathrin-mediated endocytosis. We demonstrate that, as a consequence, protein surface levels are altered in Schwann cells. Furthermore, we discovered that myelination is strictly dependent on Dnm2 and clathrin-mediated endocytosis function. Thus, we propose that altered endocytosis is a major contributing factor to the disease mechanisms in dominant intermediate Charcot-Marie-Tooth neuropathy type B.
|
Which genes are associated with autosomal dominant Charcot-Marie-Tooth?
|
In this study, we aimed to elucidate the disease mechanisms in dominant intermediate Charcot-Marie-Tooth neuropathy type B and to find explanations for the tissue-specific defects that are associated with different DNM2 mutations in dominant intermediate Charcot-Marie-Tooth neuropathy type B versus autosomal dominant centronuclear myopathy.
|
The proposed research will investigate two microbial communities that are of direct relevance to Department of Energy interests. One is the microbial community associated with the in situ bioremediation of uranium-contaminated groundwater. The second is a microbial community that harvests energy from waste organic matter in the form of electricity. These studies will address DOE needs for (1) remediation of metals and radionuclides at DOE sites and (2) the development of cleaner forms of energy and biomass conversion to energy. Our previous studies have demonstrated that the microbial communities involved in uranium bioremediation and energy harvesting are both dominated by microorganisms in the family Geobacteraceae and that the organisms in this family are responsible for uranium bioremediation and electron transfer to electrodes. The initial objectives of this study are to (1) describe the genetic potential of the Geobacteraceae that predominate in the environments of interest; (2) identify conserved patterns of gene expression within the Geobacteraceae family in response to a range of environmental conditions; (3) begin to identify mechanisms controlling the expression of key genes related to survival, growth, and activity in subsurface environments and on electrodes; and (4) use the results from subobjectives 1-3 to develop a conceptual model for predicting gene expression of Geobacteraceae in the environments of interest. This will serve as the basis for a subsequent simulation model of the growth and activity of Geobacteraceae in the subsurface and on electrodes.
|
List bacteria that may be useful in uranium bioremediation.
|
Our previous studies have demonstrated that the microbial communities involved in uranium bioremediation and energy harvesting are both dominated by microorganisms in the family Geobacteraceae and that the organisms in this family are responsible for uranium bioremediation and electron transfer to electrodes.
|
HOTAIR was proposed to regulate either HoxD cluster genes in trans or HoxC cluster genes in cis, a mechanism that remains unclear. We have identified a 32-nucleotide conserved noncoding element (CNE) as HOTAIR ancient sequence that likely originated at the root of vertebrate. The second round of whole-genome duplication resulted in one copy of the CNE within HOTAIR and another copy embedded in noncoding transcript of HOXD11. Paralogous CNEs underwent compensatory mutations, exhibit sequence complementarity with respect to transcripts directionality, and have high affinity in vitro. The HOTAIR CNE resembled a poised enhancer in stem cells and an active enhancer in HOTAIR-expressing cells. HOTAIR expression is positively correlated with HOXC11 in cis and negatively correlated with HOXD11 in trans. We propose a dual modality of HOTAIR regulation where transcription of HOTAIR and its embedded enhancer regulates HOXC11 in cis and sequence complementarity between paralogous CNEs suggests HOXD11 regulation in trans.
|
How many nucleotides long is the HOTAIR CNE?
|
HOTAIR was proposed to regulate either HoxD cluster genes in trans or HoxC cluster genes in cis, a mechanism that remains unclear. We have identified a 32-nucleotide conserved noncoding element (CNE) as HOTAIR ancient sequence that likely originated at the root of vertebrate. The second round of whole-genome duplication resulted in one copy of the CNE within HOTAIR and another copy embedded in noncoding transcript of HOXD11. Paralogous CNEs underwent compensatory mutations, exhibit sequence complementarity with respect to transcripts directionality, and have high affinity in vitro. The HOTAIR CNE resembled a poised enhancer in stem cells and an active enhancer in HOTAIR-expressing cells. HOTAIR expression is positively correlated with HOXC11 in cis and negatively correlated with HOXD11 in trans.
|
Previously, we found that treatment of cells with the Hsp90 inhibitor geldanamycin (GA) leads to a substantial reduction in the number of processing bodies (P-bodies), and also alters the size and subcellular localization of stress granules. These findings imply that the chaperone activity of Hsp90 is involved in the formation of P-bodies and stress granules. To verify these observations, we examined whether another Hsp90 inhibitor radicicol (RA) affected P-bodies and stress granules. Treatment with RA reduced the level of the Hsp90 client protein Argonaute 2 and the number of P-bodies. Although stress granules still assembled in RA-treated cells upon heat shock, they were smaller and more dispersed in the cytoplasm than those in untreated cells. Furthermore eIF4E and eIF4E-transporter were dissociated selectively from stress granules in RA-treated cells. These observations were comparable to those obtained upon treatment with GA in our previous work. Thus, we conclude that abrogation of the chaperone activity of Hsp90 affects P-body formation and the integrity of stress granules.
|
Which protein is required for Argonaute 2 recruitment to stress granules and P-bodies?
|
Treatment with RA reduced the level of the Hsp90 client protein Argonaute 2 and the number of P-bodies.
|
Ribosomal protein S19 (RPS19) is frequently mutated in Diamond-Blackfan anemia (DBA), a rare congenital hypoplastic anemia. Recent studies have shown that RPS19 expression decreases during terminal erythroid differentiation. Currently no information is available on the subcellular localization of normal RPS19 and the potential effects of various RPS19 mutations on cellular localization. In the present study, using wild-type and mutant RPS19 cDNA, we explored the subcellular distribution of normal and mutant proteins in a fibroblast cell line (Cos-7 cells). RPS19 was detected primarily in the nucleus, and more specifically in the nucleoli, where RPS19 colocalized with the nucleolar protein nucleolin. Using various N-terminal and C-terminal deletion constructs, we identified 2 nucleolar localization signals (NoSs) in RPS19: the first comprising amino acids Met1 to Arg16 in the NH2-terminus and the second comprising Gly120 to Asn142 in the COOH-terminus. Importantly, 2 mutations identified in DBA patients, Val15Phe and Gly127Gln, each of which localized to 1 of the 2 NoS, failed to localize RPS19 to the nucleolus. In addition to their mislocalization, there was a dramatic decrease in the expression of the 2 mutant proteins compared to the wild type. This decrease in protein expression was specific for the mutant RPS19, since expression of other proteins was normal. The present findings enable us to document the nucleolar localization signals in RPS19 and help define the phenotypic consequences of some mutations in RPS19 in DBA.
|
Which class of genes are mutated in Diamond Blackfan Anemia patients?
|
Ribosomal protein S19 (RPS19) is frequently mutated in Diamond-Blackfan anemia (DBA), a rare congenital hypoplastic anemia.
|
Combinatorial chemistry needs focused molecular diversity applied to the druglike chemical space (drugspace). A drugspace map can be obtained by systematically applying the same conventions when examining the chemical space, in a manner similar to the Mercator convention in geography: Rules are equivalent to dimensions (e.g., longitude and latitude), while structures are equivalent to objects (e.g., cities and countries). Selected rules include size, lipophilicity, polarizability, charge, flexibility, rigidity, and hydrogen bond capacity. For these, extreme values were set, e.g., maximum molecular weight 1500, calculated negative logarithm of the octanol/water partition between -10 and 20, and up to 30 nonterminal rotatable bonds. Only S, N, O, P, and halogens were considered as elements besides C and H. Selected objects include a set of "satellite" structures and a set of representative drugs ("core" structures). Satellites, intentionally placed outside drugspace, have extreme values in one or several of the desired properties, while containing druglike chemical fragments. ChemGPS (chemical global positioning system) is a tool that combines these predefined rules and objects to provide a global drugspace map. The ChemGPS drugspace map coordinates are t-scores extracted via principal component analysis (PCA) from 72 descriptors that evaluate the above-mentioned rules on a total set of 423 satellite and core structures. Global ChemGPS scores describe well the latent structures extracted with PCA for a set of 8599 monocarboxylates, a set of 45 heteroaromatic compounds, and for 87 alpha-amino acids. ChemGPS positions novel structures in drugspace via PCA-score prediction, providing a unique mapping device for the druglike chemical space. ChemGPS scores are comparable across a large number of chemicals and do not change as new structures are predicted, making this tool a well-suited reference system for comparing multiple libraries and for keeping track of previously explored regions of the chemical space.
|
Which are the components that evaluate druglikeness?
|
. Selected rules include size, lipophilicity, polarizability, charge, flexibility, rigidity, and hydrogen bond capacity. For these, extreme values were set, e.g., maximum molecular weight 1500, calculated negative logarithm of the octanol/water partition between -10 and 20, and up to 30 nonterminal rotatable bonds
|
null |
Moreover, computational gene finding in newly sequenced genomes is especially a difficult task due to the absence of a training set of abundant validated genes. Here we present a new gene-finding program, SCGPred, to improve the accuracy of prediction by combining multiple sources of evidence.
| null |
There is compelling evidence that glial-immune interactions contribute to the progression of neurodegenerative diseases. The adaptive immune response has been implicated in disease processes of amyotrophic lateral sclerosis (ALS), but it remains unknown if innate immune signaling also contributes to ALS progression. Here we report that deficiency of the innate immune adaptor TIR domain-containing adaptor inducing interferon-β (TRIF), which is essential for certain Toll-like receptor (TLR) signaling cascades, significantly shortens survival time and accelerates disease progression of ALS mice. While myeloid differentiation factor 88 (MyD88) is also a crucial adaptor for most TLR signaling pathways, MyD88 deficiency had only a marginal impact on disease course. Moreover, TRIF deficiency reduced the number of natural killer (NK), NK-T-lymphocytes, and CD8-T cells infiltrating into the spinal cord of ALS mice, but experimental modulation of these populations did not substantially influence survival time. Instead, we found that aberrantly activated astrocytes expressing Mac2, p62, and apoptotic markers were accumulated in the lesions of TRIF-deficient ALS mice, and that the number of aberrantly activated astrocytes was negatively correlated with survival time. These findings suggest that TRIF pathway plays an important role in protecting a microenvironment surrounding motor neurons by eliminating aberrantly activated astrocytes.
|
What links immune response pathways to ALS?
|
he adaptive immune response has been implicated in disease processes of amyotrophic lateral sclerosis (ALS), but it remains unknown if innate immune signaling also contributes to ALS progression. H
|
Signal transduction networks allow cells to recognize and respond to changes in the extracellular environment. All eukaryotic cells have MAPK (mitogen-activated protein kinase) pathways that participate in diverse cellular functions, including differentiation, survival, transformation and movement. Five distinct groups of MAPKs have been characterized in mammals, the most extensively studied of which is the Ras/Raf/MEK [MAPK/ERK (extracellular-signal-regulated kinase) kinase]/ERK cascade. Numerous stimuli, including growth factors and phorbol esters, activate MEK/ERK signalling. How disparate extracellular signals are translated by MEK/ERK into different cellular functions remains obscure. Originally identified in yeast, scaffold proteins are now recognized to contribute to the specificity of MEK/ERK pathways in mammalian cells. These scaffolds include KSR (kinase suppressor of Ras), beta-arrestin, MEK partner-1, Sef and IQGAP1. Scaffolds organize multiprotein signalling complexes. This targets MEK/ERK to specific substrates and facilitates communication with other pathways, thereby mediating diverse functions. The adaptor proteins regulate the kinetics, amplitude and localization of MEK/ERK signalling, providing an efficient mechanism that enables an individual extracellular stimulus to promote a specific biological response.
|
List scaffold proteins of the ERK signaling pathway.
|
Originally identified in yeast, scaffold proteins are now recognized to contribute to the specificity of MEK/ERK pathways in mammalian cells. These scaffolds include KSR (kinase suppressor of Ras), beta-arrestin, MEK partner-1, Sef and IQGAP1.
|
A patient with human immunodeficiency virus-1 infection presented with sub-acute liver failure, temporally related to commencement of an antiretroviral therapy regimen containing dolutegravir (Triumeq). The patient was not a carrier of HLA-B5701, and abacavir hypersensitivity was unlikely. We believe this is the first report of severe dolutegravir-related hepatotoxicity resulting in sub-acute liver failure and transplantation and highlights a potential need for closer monitoring after drug initiation.
|
List drugs included in the TRIUMEQ pill.
|
A patient with human immunodeficiency virus-1 infection presented with sub-acute liver failure, temporally related to commencement of an antiretroviral therapy regimen containing dolutegravir (Triumeq).
|
Etanercept (ETN) (Enbrel®) is a soluble protein that binds to, and specifically inhibits, tumor necrosis factor (TNF), a proinflammatory cytokine. ETN is synthesized in Chinese hamster ovary cells by recombinant DNA technology as a fusion protein, with a fully human TNFRII ectodomain linked to the Fc portion of human IgG1. Successful manufacture of biologics, such as ETN, requires sophisticated process and product understanding, as well as meticulous control of operations to maintain product consistency. The objective of this evaluation was to show that the product profile of ETN drug substance (DS) has been consistent over the course of production. Multiple orthogonal biochemical analyses, which included evaluation of attributes indicative of product purity, potency, and quality, were assessed on >2,000 batches of ETN from three sites of DS manufacture, during the period 1998-2015. Based on the key quality attributes of product purity (assessed by hydrophobic interaction chromatography HPLC), binding activity (to TNF by ELISA), potency (inhibition of TNF-induced apoptosis by cell-based bioassay) and quality (N-linked oligosaccharide map), we show that the integrity of ETN DS has remained consistent over time. This consistency was maintained through three major enhancements to the initial process of manufacturing that were supported by detailed comparability assessments, and approved by the European Medicines Agency. Examination of results for all major quality attributes for ETN DS indicates a highly consistent process for over 18 years and throughout changes to the manufacturing process, without affecting safety and efficacy, as demonstrated across a wide range of clinical trials of ETN in multiple inflammatory diseases.
|
What is the chemical structure of Etanercept (ETN)?
|
ETN is synthesized in Chinese hamster ovary cells by recombinant DNA technology as a fusion protein, with a fully human TNFRII ectodomain linked to the Fc portion of human IgG1.
|
Amyotrophic lateral sclerosis (ALS) is a multifactorial neurodegenerative disease involving motor neuron (MN) degeneration in the spinal cord, brain stem and primary motor cortex. The existence of inflammatory processes around MN and axonal degeneration in ALS has been shown. Unfortunately, none of the successful therapies in ALS animal models has improved clinical outcomes in patients with ALS. Therefore, the detection of blood biomarkers to be used as screening tools for disease onset and progression has been an expanding research area with few advances in the development of drugs for the treatment of ALS. In this review, we will address the available data analyzing regarding the relationship of lipid metabolism and lipid derived- products with ALS. We will address the advances on the studies about the role that lipids plays at the onset, progression and lifespan extension of ALS patients.
|
What links lipid metabolism pathways to ALS?
|
eview, we will address the available data analyzing regarding the relationship of lipid metabolism and lipid derived- products with ALS. We will a
|
Growth factor signaling pathways are tightly regulated by phosphorylation and include many important kinase targets of interest for drug discovery. Small molecule inhibitors of the bone morphogenetic protein (BMP) receptor kinase ALK2 (ACVR1) are needed urgently to treat the progressively debilitating musculoskeletal disease fibrodysplasia ossificans progressiva (FOP). Dorsomorphin analogues, first identified in zebrafish, remain the only BMP inhibitor chemotype reported to date. By screening an assay panel of 250 recombinant human kinases we identified a highly selective 2-aminopyridine-based inhibitor K02288 with in vitro activity against ALK2 at low nanomolar concentrations similar to the current lead compound LDN-193189. K02288 specifically inhibited the BMP-induced Smad pathway without affecting TGF-β signaling and induced dorsalization of zebrafish embryos. Comparison of the crystal structures of ALK2 with K02288 and LDN-193189 revealed additional contacts in the K02288 complex affording improved shape complementarity and identified the exposed phenol group for further optimization of pharmacokinetics. The discovery of a new chemical series provides an independent pharmacological tool to investigate BMP signaling and offers multiple opportunities for pre-clinical development.
|
What genes are drug targets for Fibrodysplasia Ossificans Progressiva (FOP)?
|
By screening an assay panel of 250 recombinant human kinases we identified a highly selective 2-aminopyridine-based inhibitor K02288 with in vitro activity against ALK2 at low nanomolar concentrations similar to the current lead compound LDN-193189
|
Patients with severe chronic neutropenia have blood neutrophil level <0.5 × 10(9)/L, predisposing them to increased susceptibility to life-threatening bacterial infections. This chapter focuses on cyclic and congenital neutropenia, two very interesting and rare hematological conditions causing severe chronic neutropenia. Both disorders respond well to treatment with the myeloid growth factor, granulocyte colony-stimulating factor (G-CSF). This chapter describes the basic features of these diseases and addresses several current clinical issues regarding their diagnosis and management. Cyclic neutropenia is a rare, inherited autosomal dominant disorder due to mutations in the gene for neutrophil elastase (ELA-2 or ELANE). Usually these patients have regular oscillation of blood neutrophil counts with periods of severe neutropenia occurring every 21 days. During these periods, they have painful mouth ulcers, fevers, and bacterial infections. The most severe consequences are gangrene, bacteremia, and septic shock. Cyclic neutropenia patients respond well to treatment with granulocyte colony-stimulating factor (G-CSF) given by subcutaneous injections on a daily or alternate-day basis. Severe congenital neutropenia is also a rare hematological disease, but it is probably more common than cyclic neutropenia. Blood neutrophils are extremely low on a continuing basis; the levels may be <0.2 × 10(9)/L, and the risk of severe bacterial infections is even greater than in cyclic neutropenia. The majority of cases are due to autosomal dominant inheritance of mutations in the ELA-2 or ELANE gene. Less commonly, mutations in HAX-1, G6PC3, and other genes cause this disorder. Treatment with G-CSF is usually effective, but the dose of G-CSF required to normalize blood neutrophils varies greatly. Ten to thirty percent of severe congenital neutropenia patients evolve to develop acute myeloid leukemia, necessitating careful clinical monitoring.
|
Which treatment leads to an increase in neutrophil counts in severe congenital neutropenia?
|
This chapter focuses on cyclic and congenital neutropenia, two very interesting and rare hematological conditions causing severe chronic neutropenia. Both disorders respond well to treatment with the myeloid growth factor, granulocyte colony-stimulating factor (G-CSF)
|
Identifying genomic variants is a fundamental first step toward the understanding of the role of inherited and acquired variation in disease. The accelerating growth in the corpus of sequencing data that underpins such analysis is making the data-download bottleneck more evident, placing substantial burdens on the research community to keep pace. As a result, the search for alternative approaches to the traditional "download and analyze" paradigm on local computing resources has led to a rapidly growing demand for cloud-computing solutions for genomics analysis. Here, we introduce the Genome Variant Investigation Platform (GenomeVIP), an open-source framework for performing genomics variant discovery and annotation using cloud- or local high-performance computing infrastructure. GenomeVIP orchestrates the analysis of whole-genome and exome sequence data using a set of robust and popular task-specific tools, including VarScan, GATK, Pindel, BreakDancer, Strelka, and Genome STRiP, through a web interface. GenomeVIP has been used for genomic analysis in large-data projects such as the TCGA PanCanAtlas and in other projects, such as the ICGC Pilots, CPTAC, ICGC-TCGA DREAM Challenges, and the 1000 Genomes SV Project. Here, we demonstrate GenomeVIP's ability to provide high-confidence annotated somatic, germline, and de novo variants of potential biological significance using publicly available data sets.
|
What is GenomeVIP?
|
Here, we introduce the Genome Variant Investigation Platform (GenomeVIP), an open-source framework for performing genomics variant discovery and annotation using cloud- or local high-performance computing infrastructure.
|
Recently, two randomized controlled phase II studies showed that acute initiation of statin treatment directly after aneurysmal subarachnoid hemorrhage (SAH) decreases the incidence of radiologic vasospasm and clinical signs of delayed cerebral ischemia (DCI), and even reduces mortality. It was hypothesized that the beneficial effect resulted from pleiotropic effects of statins. The purpose of this study was to investigate the biologic effects of acute statin treatment in patients with SAH. We performed an exploratory single-center, prospective, randomized, double-blind, placebo-controlled trial. Patients were randomized to simvastatin 80 mg or placebo once daily. A total of 32 patients were included. There were no statistically significant differences in clinical baseline characteristics. With regard to primary outcomes, there were significant differences by treatment group for total cholesterol and low-density lipoprotein (LDL) cholesterol (P<0.0001), but not for parameters of coagulation, fibrinolysis, endothelium function, and inflammation. With regard to secondary outcomes, no differences were observed in the incidence of transcranial Doppler vasospasm, clinical signs of DCI, and poor outcome. We conclude that both the primary and secondary outcome results of this study do not support a beneficial effect of simvastatin in patients with SAH.
|
Is statin use associated with improved outcomes after aneurysmal subarachnoid hemorrhage?
|
Recently, two randomized controlled phase II studies showed that acute initiation of statin treatment directly after aneurysmal subarachnoid hemorrhage (SAH) decreases the incidence of radiologic vasospasm and clinical signs of delayed cerebral ischemia (DCI), and even reduces mortality.
|
MALAT1 plays an oncogenic role in urothelial carcinoma of the bladder. Silencing MALAT1 is a potential novel therapeutic approach for this cancer.
|
Do lincRNAs play a role in human cancer?
|
Silencing MALAT1 is a potential novel therapeutic approach for this cancer.
|
Friedreich's ataxia (FRDA) is a neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin. The physiopathological consequences of frataxin deficiency are a severe disruption of iron-sulfur cluster biosynthesis, mitochondrial iron overload coupled to cellular iron dysregulation and an increased sensitivity to oxidative stress. Frataxin is a highly conserved protein, which has been suggested to participate in a variety of different roles associated with cellular iron homeostasis. The present review discusses recent advances that have made crucial contributions in understanding the molecular mechanisms underlying FRDA and in advancements toward potential novel therapeutic approaches. Owing to space constraints, this review will focus on the most commonly accepted and solid molecular and biochemical studies concerning the function of frataxin and the physiopathology of the disease. We invite the reader to read the following reviews to have a more exhaustive overview of the field [Pandolfo, M. and Pastore, A. (2009) The pathogenesis of Friedreich ataxia and the structure and function of frataxin. J. Neurol., 256 (Suppl. 1), 9-17; Gottesfeld, J.M. (2007) Small molecules affecting transcription in Friedreich ataxia. Pharmacol. Ther., 116, 236-248; Pandolfo, M. (2008) Drug insight: antioxidant therapy in inherited ataxias. Nat. Clin. Pract. Neurol., 4, 86-96; Puccio, H. (2009) Multicellular models of Friedreich ataxia. J. Neurol., 256 (Suppl. 1), 18-24].
|
What is Friedreich's Ataxia?
|
Friedreich's ataxia (FRDA) is a neurodegenerative disease caused by reduced expression of the mitochondrial protein frataxin.
|
O6-Alkylguanine-DNA alkyltransferase (EC 2.1.1.63) repairs O6-alkylguanine lesions in DNA. A homology model of the human protein (hAT) was built, based on the crystal structure of the C-terminal domain of the Ada protein, which carries out a similar repair in Escherichia coli. Sequence alignments of known O6-alkylguanine-DNA alkyltransferases were used to aid the model building using QUANTA and CHARMm software. Despite low homology in the N-terminal half (hAT residues 1-85), a well-defined topology over this region in Ada permitted successful modelling. The C-terminal half of hAT (residues 92-207) was modelled almost entirely by residue-for-residue superposition onto the Ada structure up to residue hAT175. The model was solvated to a residue radius of 8.0 A [corrected] and then minimized using CHARMm. This structural model was used to rationalize findings from site-directed mutagenesis experiments on hAT, to make further predictions on the relationship between structure and function for the alkyltransferase family of proteins, and to explain the specificity towards known small-molecule inhibitors of the protein.
|
What is the role of the Ada O6-alkylguanine alkyltransferase in bacteria?
|
O6-Alkylguanine-DNA alkyltransferase (EC 2.1.1.63) repairs O6-alkylguanine lesions in DNA.
|
Kummel disease is the eponym for avascular necrosis of the vertebral body after a vertebral compression fracture. As our population ages, the prevalence of osteoporosis, its most common fragility fracture (vertebral compression fracture), and Kummel disease will increase. The purpose of this article is to report a prototypical case with complete radiographic and histologic workup and to provide facts regarding Kummel disease that are salient to the primary care provider.
|
Is Kummell’s disease an avascular necrosis of the vertebral body?
|
Kummel disease is the eponym for avascular necrosis of the vertebral body after a vertebral compression fracture.
|
Histone H2A.X is an H2A variant present in multicellular organisms that is specifically phosphorylated on the serine in the C-terminal consensus sequence, canonically "SQEY," in response to DNA damage. We have recently shown the significance of phosphorylation of the penultimate tyrosine for maintenance and processing of the DNA damage response in mammalian cells. Here, we report the identification of distinct H2A.X variants in the eggs and early embryos of the frog Xenopus laevis that contain a C-terminal SQEF, among other changes; we have denoted these proteins as "H2A.X-F." H2A.X-F is present only in late-staged oocytes, eggs, and premidblastula transition embryos and is not present in somatic cells. Similar unannotated isoforms were identified in other rapidly developing aquatic species, such as Xenopus tropicalis, goldfish, and zebrafish, and in Arabidopsis and chickpea. Furthermore, we demonstrate by mass spectrometry and phospho-specific antibodies that H2A.X-F is phosphorylated in the absence of exogenous DNA damage, in both actively dividing, unperturbed embryos and cell-free egg extract in the absence and presence of DNA damage and S-phase checkpoint conditions. We propose that this isoform may be involved in modulating the cellular response to the rapid early cell cycles in externally developing species.
|
What histone variants play a role in the DNA damage reponse?
|
H2A.X is an H2A variant present in multicellular organisms that is specifically phosphorylated on the serine in the C-terminal consensus sequence, canonically "SQEY," in response to DNA damage.
|
Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a sensory-motor neurological disorder with a circadian component. RLS is characterized by uncomfortable sensations in the extremities, generally at night or during sleep, which often leads to an uncontrollable urge to move them for relief. Recently, genomic studies identified single-nucleotide polymorphisms in BTBD9, along with three other genes, as being associated with a higher risk of RLS. Little is known about the function of BTBD9 or its potential role in the pathophysiology of RLS. We therefore examined a line of Btbd9 mutant mice we recently generated for phenotypes similar to symptoms found in RLS patients. We observed that the Btbd9 mutant mice had motor restlessness, sensory alterations likely limited to the rest phase, and decreased sleep and increased wake times during the rest phase. Additionally, the Btbd9 mutant mice had altered serum iron levels and monoamine neurotransmitter systems. Furthermore, the sensory alterations in the Btbd9 mutant mice were relieved using ropinirole, a dopaminergic agonist widely used for RLS treatment. These results, taken together, suggest that the Btbd9 mutant mice model several characteristics similar to RLS and would therefore be the first genotypic mouse model of RLS. Furthermore, our data provide further evidence that BTBD9 is involved in RLS, and future studies of the Btbd9 mutant mice will help shine light on its role in the pathophysiology of RLS. Finally, our data argue for the utility of Btbd9 mutant mice to discover and screen novel therapeutics for RLS.
|
Willis-Ekbom disease is also known as?
|
Restless legs syndrome (RLS), also known as Willis-Ekbom disease, is a sensory-motor neurological disorder with a circadian component.
|
Vascular endothelial growth factor (VEGF) has emerged as a therapeutic target in several malignancies, including cervical cancer. Chemotherapy doublets combined with the fully humanized monoclonal antibody, bevacizumab, now constitute first-line therapy for women struggling with recurrent/metastatic cervical carcinoma. Regulatory approval for this indication was based on the phase III randomized trial, GOG 240, which demonstrated a statistically significant and clinically meaningful improvement in overall survival when bevacizumab was added to chemotherapy: 17.0 vs 13.3 months; HR 0.71; 98% CI, 0.54-0.95; p = .004. Incorporation of bevacizumab resulted in significant improvements in progression-free survival and response. These benefits were not accompanied by deterioration in quality of life. GOG 240 identified vaginal fistula as a new adverse event associated with bevacizumab use. All fistulas occurred in women who had received prior pelvic radiotherapy, and none resulted in emergency surgery, sepsis, or death. Final protocol-specified analysis demonstrated continued separation of the survival curves favoring VEGF inhibition: 16.8 vs 13.3 months; HR 0.77; 95% CI, 0.62-9.95; p = .007. Post-progression survival was not significantly different between the arms in GOG 240. Moving forward, immunotherapy has now entered the clinical trial arena to address the high unmet clinical need for effective and tolerable second line therapies in this patient population. Targeting the programmed cell death 1/programmed death ligand 1 (PD-1/PD-L1) pathway using checkpoint inhibitors to break immunologic tolerance is promising. The immunologic landscape involving human papillomavirus-positive head and neck carcinoma and cutaneous squamous cell carcinoma can be informative when considering feasibility of checkpoint blockade in advanced cervical cancer. Phase II studies using anti-PD-1 molecules, nivolumab and pembrolizumab are ongoing, and GOG 3016, the first phase III randomized trial of a checkpoint inhibitor (cemiplimab) in cervical cancer, recently activated. Important considerations in attempts to inhibit the inhibitors include pseudoprogression and post-progression survival, abscopal effects, and immune-related adverse events, including endocrinopathies.
|
What is the mechanism of action of cemiplimab?
|
Phase II studies using anti-PD-1 molecules, nivolumab and pembrolizumab are ongoing, and GOG 3016, the first phase III randomized trial of a checkpoint inhibitor (cemiplimab) in cervical cancer, recently activated.
|
Master regulator genes (MRGs) have become a hot topic in recent decades. They not only affect the development of tissue and organ systems but also play a role in other signal pathways by regulating additional MRGs. Because a MRG can regulate the concurrent expression of several genes, its mutation often leads to major diseases. Moreover, the occurrence of many tumors and cardiovascular and nervous system diseases are closely related to MRG changes. With the development in omics technology, an increasing amount of investigations will be directed toward MRGs because their regulation involves all aspects of an organism's development. This review focuses on the definition and classification of MRGs as well as their influence on disease regulation.
|
What are master regulatory genes?
|
Because a MRG can regulate the concurrent expression of several genes, its mutation often leads to major diseases.
|
Atogepant is a potent, selective, oral calcitonin gene-related peptide (CGRP) receptor antagonist in development for migraine prevention. The chemical structure of atogepant is distinct from previous CGRP receptor antagonists, which were associated with elevated serum alanine aminotransferase (ALT) in clinical trials. Here, we report the safety, tolerability, and pharmacokinetics (PKs) of a once-daily supratherapeutic dose (170 mg) of atogepant for 28 days from a randomized, double-blind, placebo-controlled phase I trial in healthy participants. Overall safety, hepatic safety, and plasma PK parameters were evaluated. Thirty-four participants aged 23-55 years enrolled; 28 (82.4%) completed the study in accordance with the protocol. Multiple doses of 170 mg atogepant for 28 consecutive days were generally well-tolerated. All adverse events (AEs; reported in 87.0% of the atogepant group; 72.7%, placebo) were mild in severity except one serious AE of subarachnoid hemorrhage due to a bicycle accident and not considered related to treatment. There were two discontinuations due to AEs, both with atogepant, one considered possibly related to treatment. Over 28 days of treatment, no participant receiving atogepant had an ALT elevation above 1.5 × upper limit of normal. Change from baseline in serum ALT levels was not different between atogepant and placebo. Atogepant is rapidly absorbed (median time to maximum plasma concentration, ~ 2 hours) with an apparent terminal half-life of ~ 11 hours, and no evidence of accumulation after once-daily dosing. Overall, atogepant at a high oral dose is safe and well-tolerated in healthy participants with no clinically meaningful elevations in ALT.
|
What is the use of Atogepant?
|
Atogepant is a potent, selective, oral calcitonin gene-related peptide (CGRP) receptor antagonist in development for migraine prevention.
|
This article reviews the molecular structure, expression pattern, physiological function, pathological roles and molecular mechanisms of Twist1 in development, genetic disease and cancer. Twist1 is a basic helix-loop-helix domain-containing transcription factor. It forms homo- or hetero-dimers in order to bind the Nde1 E-box element and activate or repress its target genes. During development, Twist1 is essential for mesoderm specification and differentiation. Heterozygous loss-of-function mutations of the human Twist1 gene cause several diseases including the Saethre-Chotzen syndrome. The Twist1-null mouse embryos die with unclosed cranial neural tubes and defective head mesenchyme, somites and limb buds. Twist1 is expressed in breast, liver, prostate, gastric and other types of cancers, and its expression is usually associated with invasive and metastatic cancer phenotypes. In cancer cells, Twist1 is upregulated by multiple factors including SRC-1, STAT3, MSX2, HIF-1α, integrin-linked kinase and NF-κB. Twist1 significantly enhances epithelial-mesenchymal transition (EMT) and cancer cell migration and invasion, hence promoting cancer metastasis. Twist1 promotes EMT in part by directly repressing E-cadherin expression by recruiting the nucleosome remodeling and deacetylase complex for gene repression and by upregulating Bmi1, AKT2, YB-1, etc. Emerging evidence also suggests that Twist1 plays a role in expansion and chemotherapeutic resistance of cancer stem cells. Further understanding of the mechanisms by which Twist1 promotes metastasis and identification of Twist1 functional modulators may hold promise for developing new strategies to inhibit EMT and cancer metastasis.
|
Which cancer types are associated with mutations in the TWIST1 gene?
|
Twist1 is expressed in breast, liver, prostate, gastric and other types of cancers, and its expression is usually associated with invasive and metastatic cancer phenotypes.
|
There is a considerable need for improvement in clinical diagnostic and staging procedures, especially with a view toward nonsurgical treatment. With the exception of eradication therapy in H. pylori-positive low-grade lymphoma of stage EI and the subgroup of locally advanced high-grade lymphoma, resection remains the treatment of choice. However, because there is an increasing trend toward stomach-conserving therapy, a randomized trial comparing cure of disease and quality of life with surgical and conservative treatment is needed.
|
What is the treatment of choice for gastric lymphoma?
|
With the exception of eradication therapy in H. pylori-positive low-grade lymphoma of stage EI and the subgroup of locally advanced high-grade lymphoma, resection remains the treatment of choice.
|
Apixaban is one of the new oral anticoagulants, which is prescribed as an alternative to vitamin K antagonists (VKAs). Concerns regarding its bleeding profile persist and require further evaluation. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) to compare the risks of bleeding and all-cause mortality between apixaban and VKAs. The MEDLINE, EMBASE, and Cochrane Library of Clinical Trials databases were systematically searched for RCTs comparing the risks of bleeding and all-cause mortality of apixaban (2.5 or 5 mg twice daily) with those of VKAs. We included RCTs conducted in adults and published in English or French. Data were pooled across RCTs using random-effects meta-analytical models. Our systematic search identified 5 RCTs meeting our inclusion criteria (n = 24,435). They included patients with atrial fibrillation (n = 18,358), total knee replacement surgery (n = 458), and venous thromboembolism (n = 5,619). Data pooled across RCTs revealed that apixaban was associated with reduced risks of any bleeding (relative risk [RR] 0.73, 95% confidence interval [CI] 0.59 to 0.90) and a composite of major or clinically relevant nonmajor bleeding (RR 0.60, 95% CI 0.40 to 0.88). Apixaban was also associated with a lower risk of intracranial bleeding (RR 0.42, 95% CI 0.31 to 0.58) whereas analyses of major and minor bleeding were inconclusive. Moreover, apixaban was associated with decreased all-cause mortality (RR 0.89, 95% CI 0.81 to 0.99) although this finding was driven by the results of the ARISTOTLE trial. In conclusion, our meta-analysis found that apixaban is associated with a lower risk of bleeding than VKAs, providing some reassurance regarding its safety.
|
Which two drugs were compared in the ARISTOTLE Trial?
|
Moreover, apixaban was associated with decreased all-cause mortality (RR 0.89, 95% CI 0.81 to 0.99) although this finding was driven by the results of the ARISTOTLE trial.
|
Acromelic frontonasal dysostosis (AFND) is a rare disorder characterized by distinct craniofacial, brain, and limb malformations, including frontonasal dysplasia, interhemispheric lipoma, agenesis of the corpus callosum, tibial hemimelia, preaxial polydactyly of the feet, and intellectual disability. Exome sequencing of one trio and two unrelated probands revealed the same heterozygous variant (c.3487C>T [p. Arg1163Trp]) in a highly conserved protein domain of ZSWIM6; this variant has not been seen in the 1000 Genomes data, dbSNP, or the Exome Sequencing Project. Sanger validation of the three trios confirmed that the variant was de novo and was also present in a fourth isolated proband. In situ hybridization of early zebrafish embryos at 24 hr postfertilization (hpf) demonstrated telencephalic expression of zswim6 and onset of midbrain, hindbrain, and retinal expression at 48 hpf. Immunohistochemistry of later-stage mouse embryos demonstrated tissue-specific expression in the derivatives of all three germ layers. qRT-PCR expression analysis of osteoblast and fibroblast cell lines available from two probands was suggestive of Hedgehog pathway activation, indicating that the ZSWIM6 mutation associated with AFND may lead to the craniofacial, brain and limb malformations through the disruption of Hedgehog signaling.
|
Which disorders are caused by de novo mutations in ZSWIM6?
|
Acromelic frontonasal dysostosis (AFND) is a rare disorder characterized by distinct craniofacial, brain, and limb malformations, including frontonasal dysplasia, interhemispheric lipoma, agenesis of the corpus callosum, tibial hemimelia, preaxial polydactyly of the feet, and intellectual disability. Exome sequencing of one trio and two unrelated probands revealed the same heterozygous variant (c.3487C>T [p. Arg1163Trp]) in a highly conserved protein domain of ZSWIM6; this variant has not been seen in the 1000 Genomes data, dbSNP, or the Exome Sequencing Project. Sanger validation of the three trios confirmed that the variant was de novo and was also present in a fourth isolated proband. In situ hybridization of early zebrafish embryos at 24 hr postfertilization (hpf) demonstrated telencephalic expression of zswim6 and onset of midbrain, hindbrain, and retinal expression at 48 hpf. Immunohistochemistry of later-stage mouse embryos demonstrated tissue-specific expression in the derivatives of all three germ layers. qRT-PCR expression analysis of osteoblast and fibroblast cell lines available from two probands was suggestive of Hedgehog pathway activation, indicating that the ZSWIM6 mutation associated with AFND may lead to the craniofacial, brain and limb malformations through the disruption of Hedgehog signaling.
|
TFIID is a large multiprotein complex that initiates assembly of the transcription machinery. It is unclear how TFIID recognizes promoters in vivo when templates are nucleosome-bound. Here, it is shown that TAFII250, the largest subunit of TFIID, contains two tandem bromodomain modules that bind selectively to multiply acetylated histone H4 peptides. The 2.1 angstrom crystal structure of the double bromodomain reveals two side-by-side, four-helix bundles with a highly polarized surface charge distribution. Each bundle contains an Nepsilon-acetyllysine binding pocket at its center, which results in a structure ideally suited for recognition of diacetylated histone H4 tails. Thus, TFIID may be targeted to specific chromatin-bound promoters and may play a role in chromatin recognition.
|
What is the structural fold of bromodomain proteins?
|
The 2.1 angstrom crystal structure of the double bromodomain reveals two side-by-side, four-helix bundles with a highly polarized surface charge distribution
|
Viroids are noncoding RNA pathogens inducing severe to mild disease symptoms on agriculturally important crop plants. Viroid replication is entirely dependent on host transcription machinery, and their replication/accumulation in the infected cells can activate RNA silencing-a host defense mechanism that targets the viroid itself. RNA silencing produces in the cell large amounts of viroid-specific small RNAs of 21-24-nucleotides by cleaving (or "dicing") entire molecules of viroid RNA. However, viroid replication is resistant to the effects of RNA silencing and disrupts the normal regulation of host gene expression, finally resulting in the development of disease symptoms on infected plant. The molecular mechanisms of biological processes involving RNA silencing and underlying various aspects of viroid-host interaction, such as symptom expression, are of special interests to both basic and applied areas of viroid research. Here we present a method to create infectious viroid cDNA clones and RNA transcripts, the starting material for such analyses, using Hop stunt viroid as an example. Next we describe methods for the preparation and analysis of viroid-specific small RNAs by deep sequencing using tomato plants infected with Potato spindle tuber viroid as an example. Finally we introduce bioinformatics tools and methods necessary to process, analyze, and characterize these viroid-specific small RNAs. These bioinformatic methods provide a powerful new tool for the detection and discovery of both known and new viroid species.
|
What is the mechanism of viroid replication?
|
Viroid replication is entirely dependent on host transcription machinery, and their replication/accumulation in the infected cells can activate RNA silencing-a host defense mechanism that targets the viroid itself.
|
The purpose of this study was to quantitate motor performance in 196 genetically confirmed steroid-naïve boys with Duchenne muscular dystrophy (DMD), to evaluate the test-retest reliability of measures of motor performance in young DMD boys, and to assess correlations among the different functional outcomes including timed tests. Boys aged 4-7 years were recruited in the FOR-DMD study, a comparative effectiveness study of different steroid regimens in DMD. Eligible boys had to be able to rise from the floor independently and to perform pulmonary function testing consistently. The boys were evaluated with standardized assessments at the screening and baseline visits at 32 sites in 5 countries (US, UK, Canada, Italy, Germany). Assessments included timed rise from floor, timed 10 m walk/run, six-minute walk distance, North Star Ambulatory Assessment (NSAA) and forced vital capacity (FVC). Mean age at baseline was 5.9 years (range 4.1-8.1 years). Test-retest reliability was high for functional assessments, regardless of time lag between assessments (up to 90 days) and for the majority of age groups. Correlations were strong among the functional measures and timed tests, less so with FVC. Physiotherapy measures are reliable in a young, steroid-naïve population and rise from floor velocity appears to be a sensitive measure of strength in this population.
|
Is North Star Ambulatory Assessment score a reliable clinical outcome for disease progression assessment in Duchenne Muscular Dystrophy?
|
The boys were evaluated with standardized assessments at the screening and baseline visits at 32 sites in 5 countries (US, UK, Canada, Italy, Germany). Assessments included timed rise from floor, timed 10 m walk/run, six-minute walk distance, North Star Ambulatory Assessment (NSAA) and forced vital capacity (FVC). Mean age at baseline was 5.9 years (range 4.1-8.1 years). Test-retest reliability was high for functional assessments, regardless of time lag between assessments (up to 90 days) and for the majority of age groups. Correlations were strong among the functional measures and timed tests, less so with FVC.
|
Clinical experience with hydroxyurea for patients with sickle cell disease (SCD) has been accumulating for the past 25 years. The bulk of the current evidence suggests that hydroxyurea is well-tolerated, safe, and efficacious for most patients with SCD. Hydroxyurea has proven clinical efficacy for reducing acute vaso-occlusive events including pain episodes and acute chest syndrome. Salutary effects on hematological parameters include increases in fetal hemoglobin (HbF), hemoglobin, and MCV; also significant decreases occur in WBC, ANC, reticulocytes, LDH, and bilirubin. Treatment with hydroxyurea is usually considered for patients with recurrent vaso-occlusive events, but additional indications for treatment may include laboratory markers of disease severity and evidence of chronic organ dysfunction. Ten years ago, the US Food and Drug Administration approved hydroxyurea for adult patients with clinically severe SCD; however, its use in children remains off-label. Despite the large body of evidence regarding its efficacy and safety, hydroxyurea is currently prescribed only sparingly for patients with SCD and therefore has only limited effectiveness for this disorder; barriers to its use need to be identified and overcome.
|
Is hydroxyurea usually used to treated infectious disease?
|
Clinical experience with hydroxyurea for patients with sickle cell disease (SCD) has been accumulating for the past 25 years. The bulk of the current evidence suggests that hydroxyurea is well-tolerated, safe, and efficacious for most patients with SCD
|
An 11-day embryonic Swiss Webster/NIH mouse cDNA library was screened with a partial murine selenoprotein P cDNA probe and a murine selenoprotein-P-type cDNA clone of 2075 bp length was obtained. The clone contained a 5'-leader sequence of 132 bp length, the selenoprotein P coding frame, and 803 base pairs in the 3' untranslated region. Alignment and RNA folding studies revealed the presence of two well conserved selenocysteine inserting motifs in the 3' flanking region. The deduced polypeptide sequence comprises 380 residues including ten selenocysteines. Identical amino acid residues in homologous positions are 86%, 71%, and 64% when compared to the previously reported selenoprotein P sequences of rat, man, and cattle, respectively. The comparatively low similarity between the selenoprotein P sequences reported so far leaves open the question whether they belong to the same molecular clade.
|
Which is the human selenoprotein that contains several Se-Cys residues?
|
The deduced polypeptide sequence comprises 380 residues including ten selenocysteines
|
Dynorphin (DYN) is an endogenous neurosecretory peptide which exerts its activity by binding to the family of G protein-coupled receptors, namely the kappa opioid receptor (KOR). Opioids are associated with pain, analgesia, and drug abuse, which play a central role in mood disorders with monoamine neurotransmitter interactions. Growing evidence demonstrates the cellular signaling cascades linked to KOR-mediated monoamine transporters regulation in cell models and native brain tissues. This chapter will review DYN/KOR role in mood and addiction in relevance to dopaminergic and serotonergic neurotransmissions. Also, we discuss the recent findings on KOR-mediated differential regulation of serotonin and dopamine transporters (SERT and DAT). These findings led to a better understanding of the role of DYN/KOR system in aminergic neurotransmission via its modulatory effect on both amine release and clearance. Detailed knowledge of these processes at the molecular level enables designing novel pharmacological reagents to target transporter motifs to treat mood and addiction and reduce unwanted side effects such as aversion, dysphoria, sedation, and psychomimesis.
|
What is the function of the protein SERT?
|
serotonin and dopamine transporters (SERT and DAT).
|
Gamma-ray irradiation introduces single and/or double strand breaks into the DNA molecule of the cells. In the case of mammalian cells, these breaks are being repaired in general during the first hr following exposure to ionizing radiation. The article reports on the results obtained from testing the ability of cultured lymphocytes from patients with Down's syndrome to repair radiation-induced DNA single-strand breaks. The ability to repair was deduced from the study of the DNA sedimentation profiles in alkaline sucrose gradients. It was found that lymphocytes from Down's syndrome patients are less efficient in repairing single-strand DNA breaks than are lymphocytes from normal individuals. This significantly increased fraction of unrepaired DNA strand breaks might be associated with the unusually high level of radiation-induced chromosome aberrations as compared with normals.
|
Are breaks in double stranded DNA associated with ionizing radiation?
|
Gamma-ray irradiation introduces single and/or double strand breaks into the DNA molecule of the cells.
|
An exosome (30-150 nm size) is a cell-derived vesicle. Exosome-induced regulation in inflammatory bowel disease (IBD) is becoming increasingly popular due to their potential functions of exosomal pathways. Exosomes, which are involved in the regulation of IBD, can be released from various cell types, or found in many physiological fluids, and plants. The specific functions of exosomes in IBD primarily depend on the internal functional components, including RNAs, proteins, and other substances. However, exosome-induced transport mechanisms involving cell-cell communications or cell-environment interactions are also very important. Recent studies have revealed that exosome crosstalk mechanisms may influence major IBD-related pathways, such as immune responses, barrier functions, and intestinal flora. This review highlights the advancements in the biology of exosome secretions and their regulation in IBD. The functional roles of exosomal components, including nucleic acids, proteins, and some other components, are the main focus of this review. More animal and clinical research is needed to study the functions of exosomes on IBD. Designing new drug dosage form using exosome-like-structure may provide new insights into IBD treatment. This review suggests a potential significance for exosomes in IBD diagnosis and treatment.
|
What is an exosome?
|
An exosome (30-150 nm size) is a cell-derived vesicle.
|
Biomarkers are currently widely used to diagnose diseases, monitor treatments, and evaluate potential drug candidates. Research of differential Omics accelerate the advancements of biomarkers' discovery. By extracting biological knowledge from the 'omics' through integration, integrative system biology creates predictive models of cells, organs, biochemical processes and complete organisms, in addition to identifying human disease biomarkers. Recent development in high-throughput methods enables analysis of genome, transcriptome, proteome, and metabolome at an unprecedented scale, thus contributing to the deluge of experimental data in numerous public databases. Several integrative system biology approaches have been developed and applied to the discovery of disease biomarkers from databases. In this review, we highlight several of these approaches and identify future steps in the context of the field of integrative system biology.
|
List omics technologies comprised in system biology.
|
Recent development in high-throughput methods enables analysis of genome, transcriptome, proteome, and metabolome at an unprecedented scale, thus contributing to the deluge of experimental data in numerous public databases.
|
Inflammatory bowel disease (IBD) is considered a chronic condition characterized by mucosal or transmural inflammation in the gastrointestinal tract. Endoscopic diagnosis and surveillance in patients with IBD have become crucial. In addition, endoscopy is a useful modality in estimation and evaluation of the disease, treatment results, and efficacy of treatment delivery and surveillance. In relation to these aspects, endoscopic disease activity has been commonly estimated in clinical practices and trials.<br/> At present, many endoscopic indices of ulcerative colitis have been introduced, including the Truelove and Witts Endoscopy Index, Baron Index, Powell-Tuck Index, Sutherland Index, Mayo Clinic Endoscopic Sub-Score, Rachmilewitz Index, Modified Baron Index, Endoscopic Activity Index, Ulcerative Colitis Endoscopic Index of Severity, Ulcerative Colitis Colonoscopic Index of Severity, and Modified Mayo Endoscopic Score. Endoscopic indices have been also suggested for Crohn's disease, such as the Crohn's Disease Endoscopic Index of Severity, Simple Endoscopic Score for Crohn's Disease, and Rutgeerts Postoperative Endoscopic Index. However, most endoscopic indices have not been validated owing to the complexity of their parameters and inter-observer variations. Therefore, a chronological approach for understanding the various endoscopic indices relating to IBD is needed to improve the management.
|
Rachmilewitz Index is used for which diseases?
|
At present, many endoscopic indices of ulcerative colitis have been introduced, including the Truelove and Witts Endoscopy Index, Baron Index, Powell-Tuck Index, Sutherland Index, Mayo Clinic Endoscopic Sub-Score, Rachmilewitz Index, Modified Baron Index, Endoscopic Activity Index, Ulcerative Colitis Endoscopic Index of Severity, Ulcerative Colitis Colonoscopic Index of Severity, and Modified Mayo Endoscopic Score.
|
Preterm premature rupture of membranes (PPROM) occurs in 1% to 2% of births. Impact of PPROM is greatest in low- and middle-income countries where prematurity-related deaths are most common. Recent investigations identify cytokine and matrix metalloproteinase activation, oxidative stress, and apoptosis as primary pathways to PPROM. These biological processes are initiated by heterogeneous etiologies including infection/inflammation, placental bleeding, uterine overdistention, and genetic polymorphisms. We hypothesize that pathways to PPROM overlap and act synergistically to weaken membranes. We focus our discussion on membrane composition and strength, pathways linking risk factors to membrane weakening, and future research directions to reduce the global burden of PPROM.
|
Is PPROM a condition that occurs in males or females?
|
Preterm premature rupture of membranes (PPROM) occurs in 1% to 2% of births. Im
|
Understanding the structure and function of cortical circuits requires the identification of and control over specific cell types in the cortex. To address these obstacles, recent optogenetic approaches have been developed. The capacity to activate, silence, or monitor specific cell types by combining genetics, virology, and optics will decipher the role of specific groups of neurons within circuits with a spatiotemporal resolution that overcomes standard approaches. In this review, the various strategies for selective genetic targeting of a defined neuronal population are discussed as well as the pros and cons of the use of transgenic animals and recombinant viral vectors for the expression of transgenes in a specific set of neurons.
|
What are viral vectors used for in optogenetics?
|
In this review, the various strategies for selective genetic targeting of a defined neuronal population are discussed as well as the pros and cons of the use of transgenic animals and recombinant viral vectors for the expression of transgenes in a specific set of neurons.
|
The apicomplexan parasite Cryptosporidium parvum possesses a mitosome, a relict mitochondrion with a greatly reduced metabolic capability. This mitosome houses a mitochondrial-type protein import apparatus, but elements of the protein import pathway have been reduced, and even lost, through evolution. The small Tim protein family is a case in point. The genomes of C. parvum and related species of Cryptosporidium each encode just one small Tim protein, CpTimS. This observation challenged the tenet that small Tim proteins are always found in pairs as α3β3 hexamers. We show that the atypical CpTimS exists as a relatively unstable homohexamer, shedding light both on the early evolution of the small Tim protein family and on small Tim hexamer formation in contemporary eukaryotes.
|
What is a mitosome?
|
a mitosome, a relict mitochondrion with a greatly reduced metabolic capability.
|
Avolition affects quality of life in chronic schizophrenia. We investigated the effect of modafinil upon unconstrained motor activity in 18 male patients. In a randomised crossover design study, wrist-worn actigraphic monitors were used to objectively record motor activity over a 20 h period. Patients' total activity was significantly greater when given the drug. These data suggest that modafinil increases quantifiable motor behaviour in schizophrenia and may have an impact on avolition.
|
Was modafinil tested for schizophrenia treatment?
|
. These data suggest that modafinil increases quantifiable motor behaviour in schizophrenia and may have an impact on avolition.
|
Women ages 50 years and older are at risk for herpes zoster, a reactivated virus from varicella zoster virus (chickenpox) that causes a painful vesicular rash and can result in postherpetic neuralgia. It is estimated that one in three adults will be affected by herpes zoster in their lifetime. Research evidence points to the need to prevent herpes zoster through vaccination. Since 2006, clinicians have been vaccinating adults with zoster vaccine live (brand name Zostavax), but the efficacy of this vaccine wanes with time and advanced age. In October 2017, the U.S. Food and Drug Administration approved recombinant zoster vaccine under the brand name Shingrix to prevent herpes zoster. Studies have shown significantly better efficacy of Shingrix versus Zostavax. This article summarizes new guidance regarding vaccination with Shingrix and discusses implications for women's health.
|
The Shingrix vaccine is used to prevent what disease?
|
Women ages 50 years and older are at risk for herpes zoster, a reactivated virus from varicella zoster virus (chickenpox) that causes a painful vesicular rash and can result in postherpetic neuralgia.
|
Gardner Diamond syndrome is a rare condition characterized with painful ecchymoses in different parts of the body and cutaneous and mucosal hemorrhages. The etiology is not known fully and psychogenic factors are thought to be involved. Cutaneous lesions and hemorrhages develop mostly following emotional stress and rarely minor traumas and may recur. Although the extremities are involved with the highest rate, the lesions may be observed in any part of the body. Hemostatic tests are generally normal. The majority of the subjects is composed of young women. It is observed more rarely in men and children. In this article, a patient who presented with recurring painful echymoses and bleeding disorder and diagnosed with Gardner Diamond syndrome by intracutaneous injection of autologous blood was presented to emphasize that this syndrome is observed rarely in the childhood and should be considered not only in the differential diagnosis of cutaneous lesions, but also in the differential diagnosis of various system hemorrhages.
|
What is clinical presentation of the Gardner-Diamond syndrome?
|
Gardner Diamond syndrome is a rare condition characterized with painful ecchymoses in different parts of the body and cutaneous and mucosal hemorrhages. The etiology is not known fully and psychogenic factors are thought to be involved.
|
The Cajal (coiled) body is a discrete nuclear organelle that was first described in mammalian neurons in 1903. Because the molecular composition, structure, and function of Cajal bodies were unknown, these enigmatic structures were largely ignored for most of the last century. The Cajal body has now regained the interest of biologists, due to the isolation of a protein marker, coilin. Despite current widespread use of coilin to identify Cajal bodies in various cell types, its structure and function are still little understood. Here, I would like to discuss what we have learned about coilin and suggest a possible role for coilin in RNA processing and cellular trafficking, especially in relation to Cajal bodies and nucleoli. Although coilin has been investigated primarily in somatic cells, I will emphasize the advantages of using the amphibian oocyte to study nuclear proteins and organelles.
|
Which protein is the main marker of Cajal bodies?
|
Here, I would like to discuss what we have learned about coilin and suggest a possible role for coilin in RNA processing and cellular trafficking, especially in relation to Cajal bodies and nucleoli.
|
Dupilumab is the first US FDA approved biologic for treatment of atopic dermatitis. It is a human monoclonal antibody which blocks the shared receptor component, the interleukin (IL)-4α subunit, of IL-4 and IL-13 signaling pathways. Occurrence of "conjunctivitis", mostly in atopic dermatitis trials, has been the main side effect reported thus far. The etiology of "conjunctivitis" associated with dupilumab treatment is unclear and might be similar to atopic keratoconjunctivitis. There is evidence in the published literature that unlike the Th2-like profile in vernal keratoconjunctivitis, Th1-mediated inflammation is predominant in atopic keratoconjunctivitis. Blocking the Th2 pathway with dupilumab therapy might result in a shift towards Th1, causing the ocular findings associated with dupilumab. In addition, blockage of IL-13 might have implications with regards to mucin production and ocular surface health. This review highlights the clinical manifestations, reviews treatment options and offers explanations for pathogenesis of this ocular surface diseases associated with dupilumab treatment.
|
Has dupilumab been FDA approved for atopic dermatitis?
|
Dupilumab is the first US FDA approved biologic for treatment of atopic dermatitis.
|
The transcription factor Max is a basic-helix-loop-helix leucine zipper (bHLHLZ) protein that forms homodimers or interacts with other bHLHLZ proteins, including Myc and Mxd proteins. Among this dynamic network of interactions, the Myc/Max heterodimer has crucial roles in regulating normal cellular processes, but its transcriptional activity is deregulated in a majority of human cancers. Despite this significance, the arsenal of high-quality chemical probes to interrogate these proteins remains limited. We used small molecule microarrays to identify compounds that bind Max in a mechanistically unbiased manner. We discovered the asymmetric polycyclic lactam, KI-MS2-008, which stabilizes the Max homodimer while reducing Myc protein and Myc-regulated transcript levels. KI-MS2-008 also decreases viable cancer cell growth in a Myc-dependent manner and suppresses tumor growth in vivo. This approach demonstrates the feasibility of modulating Max with small molecules and supports altering Max dimerization as an alternative approach to targeting Myc.
|
Which small molecules inhibit the c-Myc/Max dimerization?
|
ered the asymmetric polycyclic lactam, KI-MS2-008, which stabilizes the Max homodimer while reducing Myc protein and Myc-regulated transcript levels. KI-MS2-00
|
The strength of the evidence relating to this compound is limited, owing to small sample size, poor study design, limited outcomes and incomplete reporting. Molindone may be an effective antipsychotic; however, its adverse effect profile does not differ significantly from that of typical antipsychotics, apart from the event of weight loss. At present there is no evidence to suggest that it may have an atypical profile.
|
Does molindone affect body weight?
|
Molindone may be an effective antipsychotic; however, its adverse effect profile does not differ significantly from that of typical antipsychotics, apart from the event of weight loss.
|
Diagnosis of tuberculosis (TB) is difficult, since symptoms are often very unspecific or lacking. However active, prompt and accurate diagnosis is the key element in the public health response to tuberculosis and the cornerstone of tuberculosis control. Different diagnostic methods for an assured diagnosis of TB are necessary. Chest radiography is a useful keystone to identify tuberculosis, but diagnosis of tuberculosis cannot be established by radiography alone. CT scanning is used in patients without pathological chest radiography but clinically suspected active TB and to differentiate TB from other diseases. Radiological appearance is primarily determined by the immune status of patients and caverns and disseminated disease foci are often observed. Laboratory diagnostic methods include microscopic identification of acid-fast mycobacteria from any body fluid (especially sputum), as well as isolation and characterisation of mycobacteria in culture. It is then possible to type the pathogens by the shape of their colony, their growth behavior and their biochemical characteristics. These methods are regarded as the gold standard in diagnosis of active TB. In patients who are highly suspected of having TB, but whose sputum specimens tested negative for mycobacteria, a nucleic acid amplification test is additionally performed. Moreover, sensitivity testing with first and second line antitubercular drugs is applied as standard. Laboratory diagnostic testing of cellular immunity against pathogenic mycobacteria employs the tuberculin skin test (TST, Mantoux tuberculin test) or the more specific interferon γ test to determine γ interferon released by T lymphocytes stimulated in vitro. The new ELISA and ELISPOT procedures exhibit higher test specificity and less cross reactivity to NTM (non-tuberculosis mycobacteria), are independent of BCG-vaccination status and correlate better with the degree of exposure than does the TST.
|
The Mantoux test detects what latent infection/disease?
|
Laboratory diagnostic testing of cellular immunity against pathogenic mycobacteria employs the tuberculin skin test (TST, Mantoux tuberculin test)
|
Orexin receptor antagonism represents a novel approach for the treatment of insomnia that directly targets sleep/wake regulation. Several such compounds have entered into clinical development, including the dual orexin receptor antagonists, suvorexant and almorexant. In this study, we have used equilibrium and kinetic binding studies with the orexin-2 (OX₂) selective antagonist radioligand, [³H]-EMPA, to profile several orexin receptor antagonists. Furthermore, selected compounds were studied in cell-based assays of inositol phosphate accumulation and ERK-1/2 phosphorylation in CHO cells stably expressing the OX2 receptor that employ different agonist incubation times (30 and 5 min, respectively). EMPA, suvorexant, almorexant and TCS-OX-29 all bind to the OX₂ receptor with moderate to high affinity (pk(I) values ≥ 7.5), whereas the primarily OX1 selective antagonists SB-334867 and SB-408124 displayed low affinity (pK(I) values ca. 6). Competition kinetic analysis showed that the compounds displayed a range of dissociation rates from very fast (TCS-OX2-29, k(off) = 0.22 min⁻¹) to very slow (almorexant, k(off) = 0.005 min⁻¹). Notably, there was a clear correlation between association rate and affinity. In the cell-based assays, fast-offset antagonists EMPA and TCS-OX2-29 displayed surmountable antagonism of orexin-A agonist activity. However, both suvorexant and particularly almorexant cause concentration-dependent depression in the maximal orexin-A response, a profile that is more evident with a shorter agonist incubation time. Analysis according to a hemi-equilibrium model suggests that antagonist dissociation is slower in a cellular system than in membrane binding; under these conditions, almorexant effectively acts as a pseudo-irreversible antagonist.
|
Which receptors are targeted by suvorexant?
|
Several such compounds have entered into clinical development, including the dual orexin receptor antagonists, suvorexant and almorexant.
|
Postdural puncture headache (PDPH) has been a problem for patients, following dural puncture, since August Bier reported the first case in 1898. His paper discussed the pathophysiology of low-pressure headache resulting from leakage of cerebrospinal fluid (CSF) from the subarachnoid to the epidural space. Clinical and laboratory research over the last 30 years has shown that use of small-gauge needles, particularly of the pencil-point design, is associated with a lower risk of PDPH than traditional cutting point needle tips (Quincke-point needle). A careful history can rule out other causes of headache. A postural component of headache is the sine qua non of PDPH. In high-risk patients , for example, age < 50 years, postpartum, large-gauge needle puncture, epidural blood patch should be performed within 24-48 h of dural puncture. The optimum volume of blood has been shown to be 12-20 mL for adult patients. Complications of AEBP are rare.
|
What is the definitive treatment for low pressure headache?
|
In high-risk patients , for example, age < 50 years, postpartum, large-gauge needle puncture, epidural blood patch should be performed
|
Dual-Specificity Phosphatases (DUSPs) are enzymes that remove phosphate groups from both phospho-tyrosine and phospho-serine/threonine residues. A subgroup of DUSPs specifically targets Mitogen-Activated Protein Kinases (MAPKs) and has been shown to participate in the regulation of differential cellular responses to the large variety of stimuli conveyed by MAPK-pathways. In Drosophila, Puckered has been identified as a DUSP, exhibiting specificity towards the c-Jun-N-terminal kinase (JNK). Recent studies have signified its role in regulating JNK-dependent processes, including immunity, stress tolerance and longevity. Puckered expression depends on the activation of the JNK pathway whereas it's degradation is mediated by the ubiquitin-proteasome system. In this study we show that Puckered is phosphorylated by JNK and p38 in response to arsenite-induced oxidative stress and that phosphorylation affects the interaction between Puckered and these MAPKs. In silico analysis of the Puckered amino acid sequence revealed several MAPK consensus phosphorylation motifs. Expression of Puckered in the heterologous system of HEK293 cells and subsequent stimulation with arsenite resulted in reduced mobility of Puckered in SDS-PAGE. Similar results were obtained when Puckered was co-expressed with the constitutively active forms of JNK and p38. This mobility shift was abolished by lambda-phosphatase treatment or by simultaneous inhibition of JNK and p38. Analysis by mass-spectrometry identified Puckered phosphorylation in Ser413, though phosphorylation on this site was found irrespective of stimulation. Finally, phosphorylation of Puckered enhanced its interaction both with JNK and p38. Our results suggest a possible functional role of Puckered phosphorylation by MAPKs.
|
What is the function of the enzymes known as dual specificity phoshpatases (DUSPs)?
|
Dual-Specificity Phosphatases (DUSPs) are enzymes that remove phosphate groups from both phospho-tyrosine and phospho-serine/threonine residues. A subgroup of DUSPs specifically targets Mitogen-Activated Protein Kinases (MAPKs) and has been shown to participate in the regulation of differential cellular responses to the large variety of stimuli conveyed by MAPK-pathways.
|
Inherited causes account for about 50% of individuals presenting with childhood (prelingual) hearing loss, of which 70% are due to mutation in numerous single genes which impair auditory function alone (non-syndromic). The remainder are associated with other developmental anomalies termed syndromic deafness. Genes responsible for syndromic forms of hearing loss include the COL4A5 gene in Alport syndrome and the PAX3 and MITF genes in Waardenburg syndrome. Pendred syndrome is an autosomal recessive disorder associated with developmental abnormalities of the cochlea, sensorineural hearing loss and diffuse thyroid enlargement (goitre). Pendred syndrome is the most common syndromal form of deafness, yet the primary defect remains unknown. We have established a panel of 12 families with two or more affected individuals and used them to search for the location of the Pendred gene by linkage analysis. We excluded localization to four previously mapped nonsyndromic deafness loci but obtained conclusive evidence for linkage of the Pendred syndrome gene to microsatellite markers on chromosome 7q31 (D7S495 Zmax 7.32, Qmax = 0). This region contains a gene, DFNBL, for autosomal recessive non-syndromic sensorineural hearing loss. Multipoint analysis indicates that DFNB4 and Pendred syndrome co-localize to the same 5.5 centiMorgan (cM) interval flanked by D7S501 and D7S523. These data raise the possibility that Pendred syndrome is either allelic with DFNB4 or may represent an inherited contiguous gene disorder, not clinically manifest in the heterozygote.
|
What are the main clinical characteristics of Pendred syndrome?
|
Pendred syndrome is the most common syndromal form of deafness, yet the primary defect remains unknown.
|
Acute myeloid leukaemia (AML) is the most common acute leukaemia in adults. Around 10-15% of individuals with recessively inherited Fanconi anaemia (FA) develop AML. FA is one of a group of recessive syndromes characterized by excessive spontaneous chromosomal breakage in which heterozygote carriers appear to display an increased risk of cancer and there is some indirect evidence that FA carriers may also be at increased risk of AML. This suggests that FA genes may play a role in the development of AML in the wider context. To examine this proposition, further, we have screened samples from 79 AML patients for mutations in the major FA gene, FANCA. No truncating FANCA mutations were detected. One missense mutation previously designated as pathogenic and five novel missense mutations causing non-conservative amino acid substitutions were detected. The data suggests that while FANCA mutations are rare, FANCA mutations may contribute to the development of the disease in a subset of AML.
|
What constitutes an increased risk for individuals with Fanconi anemia?
|
FA is one of a group of recessive syndromes characterized by excessive spontaneous chromosomal breakage in which heterozygote carriers appear to display an increased risk of cancer and there is some indirect evidence that FA carriers may also be at increased risk of AML
|
Hypotrichosis with juvenile macular dystrophy (HJMD) and ectodermal dysplasia, ectrodactyly and macular dystrophy (EEM) are both caused by mutations in the CDH3 gene. In this report, we describe a family with EEM syndrome caused by a novel CDH3 gene mutation and review the mutation spectrum and limb abnormalities in both EEM and HJMD. A protein structure model showing the localization of different mutations causing both syndromes is presented. The CDH3 gene was sequenced and investigation of the mutations performed using a protein structure model. The conservation score was calculated by ConSurf. We identified a novel CDH3 gene mutation, p.G277V, which resides in a conserved residue located on a β-strand in the second cadherin domain. Review of the data on previously published mutations showed intra-familial and inter-familial variations in the severity of the limb abnormalities. Syndactyly was the most consistent clinical finding present in all the patients regardless of mutation type. The results of our study point to a phenotypic continuum between HJMD and EEM. It is important for genetic counseling to keep in mind the possible clinical/phenotypic overlap between these 2 syndromes and to be aware of the possible risk of limb abnormalities in future pregnancies in families with HJMD syndrome. CDH3 gene mutation screening is recommended in patients with both these syndromes as part of the work-up in order to offer appropriate genetic counseling.
|
List clinical features of EEM syndrome.
|
Hypotrichosis with juvenile macular dystrophy (HJMD) and ectodermal dysplasia, ectrodactyly and macular dystrophy (EEM) are both caused by mutations in the CDH3 gene.
|
Disturbed Wnt signaling has been implicated in numerous diseases, including type 2 diabetes and the metabolic syndrome. In the present study, we have investigated cross-talk between insulin and Wnt signaling pathways using preadipocytes with and without knockdown of the Wnt co-receptors LRP5 and LRP6 and with and without knock-out of insulin and IGF-1 receptors. We find that Wnt stimulation leads to phosphorylation of insulin signaling key mediators, including Akt, GSK3β, and ERK1/2, although with a lower fold stimulation and slower time course than observed for insulin. These Wnt effects are insulin/IGF-1 receptor-dependent and are lost in insulin/IGF-1 receptor double knock-out cells. Conversely, in LRP5 knockdown preadipocytes, insulin-induced phosphorylation of IRS1, Akt, GSK3β, and ERK1/2 is highly reduced. This effect is specific to insulin, as compared with IGF-1, stimulation and appears to be due to an inducible interaction between LRP5 and the insulin receptor as demonstrated by co-immunoprecipitation. These data demonstrate that Wnt and insulin signaling pathways exhibit cross-talk at multiple levels. Wnt induces phosphorylation of Akt, ERK1/2, and GSK3β, and this is dependent on insulin/IGF-1 receptors. Insulin signaling also involves the Wnt co-receptor LRP5, which has a positive effect on insulin signaling. Thus, altered Wnt and LRP5 activity can serve as modifiers of insulin action and insulin resistance in the pathophysiology of diabetes and metabolic syndrome.
|
Is there any cross-talk between the Wnt and the Akt pathways?
|
Wnt induces phosphorylation of Akt, ERK1/2, and GSK3β, and this is dependent on insulin/IGF-1 receptors.
|
Transcriptional enhancers are non-coding segments of DNA that play a central role in the spatiotemporal regulation of gene expression programs. However, systematically and precisely predicting enhancers remain a major challenge. Although existing methods have achieved some success in enhancer prediction, they still suffer from many issues. We developed a deep learning-based algorithmic framework named PEDLA (https://github.com/wenjiegroup/PEDLA), which can directly learn an enhancer predictor from massively heterogeneous data and generalize in ways that are mostly consistent across various cell types/tissues. We first trained PEDLA with 1,114-dimensional heterogeneous features in H1 cells, and demonstrated that PEDLA framework integrates diverse heterogeneous features and gives state-of-the-art performance relative to five existing methods for enhancer prediction. We further extended PEDLA to iteratively learn from 22 training cell types/tissues. Our results showed that PEDLA manifested superior performance consistency in both training and independent test sets. On average, PEDLA achieved 95.0% accuracy and a 96.8% geometric mean (GM) of sensitivity and specificity across 22 training cell types/tissues, as well as 95.7% accuracy and a 96.8% GM across 20 independent test cell types/tissues. Together, our work illustrates the power of harnessing state-of-the-art deep learning techniques to consistently identify regulatory elements at a genome-wide scale from massively heterogeneous data across diverse cell types/tissues.
|
Which deep learning-based algorithms are used for enhancer prediction?
|
We developed a deep learning-based algorithmic framework named PEDLA (https://github.com/wenjiegroup/PEDLA), which can directly learn an enhancer predictor from massively heterogeneous data and generalize in ways that are mostly consistent across various cell types/tissues.
|
Vitamin D had an anti-infection effect and benefited to the intestinal health. Autophagy signaling pathway was regulated by vitamin D3 to inhibit the infection of human immunodeficiency virus type-1. Rotavirus (RV) was a major cause of the severe diarrheal disease in young children and young animals. Although evidence suggested that vitamin D3 attenuates the negative effects of RV infection via the retinoic acid-inducible gene I signaling pathway, little is known of its antiviral effect whether through the regulation of autophagy. The present study was performed to investigate whether vitamin D3 alleviates RV infection in pig and porcine small intestinal epithelial cell line (IPEC-J2) models via regulating the autophagy signaling pathway. RV administration increased the Beclin 1 mRNA abundance in porcine jejunum and ileum. 5000 IU/kg dietary vitamin D3 supplementation greatly up-regulated LC3-II/LC3-I ratios and PR-39 mRNA expression under the condition of RV challenged. The viability of IPEC-J2 was significantly inhibited by RV infection. Incubation with 25-hydroxyvitamin D3 significantly decreased the concentrations of RV antigen and non-structural protein 4 (NSP4), and up-regulated the mRNA expression of Beclin 1 and PR-39 in the RV-infected IPEC-J2 cells. And then, based on the 25-hydroxyvitamin D3 treatment and RV infection, LC3-II mRNA expression in cells was inhibited by an autophagy inhibitor 3-methyladenine (3-MA). Bafilomycin A1 (Baf A1, a class of inhibitors of membrane ATPases, inhibits maturation of autophagic vacuoles) treatment numerically enhanced the LC3-II mRNA abundance, but had no effect on NSP4 concentration. Furthermore, 25-hydroxyvitamin D3 decreased the p62 mRNA expression and increased porcine cathelicidins (PMAP23, PG1-5 and PR-39) mRNA expression in the RV-infected cells. Taken together, these results indicated that vitamin D3 attenuates RV infection through regulating autophagic maturation and porcine cathelicidin genes expression.
|
Does Vitamin D induce autophagy?
|
Autophagy signaling pathway was regulated by vitamin D3
|
This is a summary of a research study (known as a clinical trial) called CROWN. The study tested two medicines called lorlatinib and crizotinib in participants with untreated non-small cell lung cancer that had spread to other parts of their body. All those who took part had changes in a gene called ALK, which is involved in cell growth. In total, 296 participants from 23 countries took part. Half the participants took lorlatinib and half took crizotinib. After participants started taking lorlatinib or crizotinib, they were checked regularly to see if their tumors had grown or spread to other parts of their body (known as tumor progression) and to monitor any side effects. After 1 year of treatment, the participants who took lorlatinib were twice as likely to be alive with no tumor growth as the participants who took crizotinib. More participants who took lorlatinib had cancer that shrank (76%) compared with the participants who took crizotinib (58%). This was also true of the participants whose cancer had spread to their brain. The most common side effects in participants who took lorlatinib were increases in the amount of cholesterol and triglycerides (a type of fat) in their blood, swelling, weight gain, nerve damage, unclear thoughts, and diarrhea. Among the participants who took crizotinib, the most common side effects were diarrhea, feeling like you want to throw up, sight problems, swelling, vomiting, changes in liver function, and feeling tired. Overall, the CROWN study showed that fewer participants with advanced ALK+ non-small cell lung cancer died or had tumor growth with lorlatinib compared with crizotinib treatment. ClinicalTrials.gov NCT number: NCT03052608.
|
When is lorlatinib used?
|
The study tested two medicines called lorlatinib and crizotinib in participants with untreated non-small cell lung cancer that had spread to other parts of their body. All those who took part had changes in a gene called ALK, which is involved in cell growth.
|
Features of chromosomal aberrations, hypersensitivity to DNA crosslinking agents, and predisposition to malignancy have suggested a fundamental anomaly of DNA repair in Fanconi anemia. The function of the recently isolated FACC (Fanconi anemia group C complementing) gene for a subset of this disorder is not yet known. The notion that FACC plays a direct role in DNA repair would predict that the polypeptide should reside in the nucleus. In this study, a polyclonal antiserum raised against FACC was used to determine the subcellular location of the polypeptide. Immunofluorescence and subcellular fractionation studies of human cell lines as well as COS-7 cells transiently expressing human FACC showed that the protein was localized primarily to the cytoplasm under steady-state conditions, transit through the cell cycle, and exposure to crosslinking or cytotoxic agents. However, placement of a nuclear localization signal from the simian virus 40 large tumor antigen at the amino terminus of FACC directed the hybrid protein to the nuclei of transfected COS-7 cells. These observations suggest an indirect role for FACC in regulating DNA repair in this group of Fanconi anemia.
|
Which are the main clinical features of Fanconi anemia?
|
Features of chromosomal aberrations, hypersensitivity to DNA crosslinking agents, and predisposition to malignancy have suggested a fundamental anomaly of DNA repair in Fanconi anemia.
|
Diamond-Blackfan Anemia (DBA) is characterized by a defect of erythroid progenitors and, clinically, by anemia and malformations. DBA exhibits an autosomal dominant pattern of inheritance with incomplete penetrance. Currently nine genes, all encoding ribosomal proteins (RP), have been found mutated in approximately 50% of patients. Experimental evidence supports the hypothesis that DBA is primarily the result of defective ribosome synthesis. By means of a large collaboration among six centers, we report here a mutation update that includes nine genes and 220 distinct mutations, 56 of which are new. The DBA Mutation Database now includes data from 355 patients. Of those where inheritance has been examined, 125 patients carry a de novo mutation and 72 an inherited mutation. Mutagenesis may be ascribed to slippage in 65.5% of indels, whereas CpG dinucleotides are involved in 23% of transitions. Using bioinformatic tools we show that gene conversion mechanism is not common in RP genes mutagenesis, notwithstanding the abundance of RP pseudogenes. Genotype-phenotype analysis reveals that malformations are more frequently associated with mutations in RPL5 and RPL11 than in the other genes. All currently reported DBA mutations together with their functional and clinical data are included in the DBA Mutation Database.
|
Which class of genes are mutated in Diamond Blackfan Anemia patients?
|
Currently nine genes, all encoding ribosomal proteins (RP), have been found mutated in approximately 50% of patients.
|
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.
|
Is TALEN being used on stem cells?
|
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
|
For therapies based on human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (CM) to be effective, arrhythmias must be avoided. Towards achieving this goal, light-activated channelrhodopsin-2 (ChR2), a cation channel activated with 480 nm light, and a first generation halorhodopsin (NpHR1.0), an anion pump activated by 580 nm light, have been introduced into hiPSC. By using in vitro approaches, hiPSC-CM are able to be optogenetically activated and inhibited. ChR2 and NpHR1.0 are stably transduced into undifferentiated hiPSC via a lentiviral vector. Via directed differentiation, both wildtype hiPSC-CM (hiPSC(WT)-CM) and hiPSC(ChR2/NpHR)-CM are produced and subjected to both electrical and optical stimulation. Both hiPSC(WT)-CM and hiPSC(ChR2/NpHR)-CM respond to traditional electrical stimulation and produce similar contractility features but only hiPSC(ChR2/NpHR)-CM can be synchronized and inhibited by optical stimulation. Here it is shown that light sensitive proteins can enable in vitro optical control of hiPSC-CM. For future therapy, in vivo optical stimulation could allow precise and specific synchronization of implanted hiPSC-CM with patient cardiac rates and rhythms.
|
What color light does the the inhibitory receptor halorhodopsin (eNpHR) respond to?
|
Towards achieving this goal, light-activated channelrhodopsin-2 (ChR2), a cation channel activated with 480 nm light, and a first generation halorhodopsin (NpHR1.
|
Tuberous Sclerosis Complex (TSC) is a multiorgan genetic disease caused by loss of function of either the TSC1 (encodes hamartin) or TSC2 (encodes tuberin) genes. Patients with TSC have benign tumors (hamartomas) in multiple organs though brain involvement is typically the most disabling aspect of the disease as very high rates of neurodevelopmental disorders are seen. While first described well over 120 years ago, recent advances have transformed TSC into a prototypical disorder that exemplifies the methods and potential of molecular medicine. This review will detail historical aspects of TSC and its strong associations with neurodevelopmental disorders focusing on epilepsy and autism. Finally, promising new approaches for the treatment of epilepsy and autism in patients with TSC as well as those in the general population will be discussed.
|
Is Tuberous Sclerosis a genetic disease?
|
Tuberous Sclerosis Complex (TSC) is a multiorgan genetic disease
|
DNA methylation and nucleosome positioning are two key mechanisms that contribute to the epigenetic control of gene expression. During carcinogenesis, the expression of many genes is altered alongside extensive changes in the epigenome, with repressed genes often being associated with local DNA hypermethylation and gain of nucleosomes at their promoters. However the spectrum of alterations that occur at distal regulatory regions has not been extensively studied. To address this we used Nucleosome Occupancy and Methylation sequencing (NOMe-seq) to compare the genome-wide DNA methylation and nucleosome occupancy profiles between normal and cancer cell line models of the breast and prostate. Here we describe the bioinformatic pipeline and methods that we developed for the processing and analysis of the NOMe-seq data published by (Taberlay et al., 2014 [1]) and deposited in the Gene Expression Omnibus with accession GSE57498.
|
What is measured through the NOMe-Seq methodology?
|
Here we describe the bioinformatic pipeline and methods that we developed for the processing and analysis of the NOMe-seq data published by (Taberlay et al., 2014 [1]) and deposited in the Gene Expression Omnibus with accession GSE57498.
|
Centromeres contain specialized chromatin that includes the centromere-specific histone H3 variant, spCENP-A/Cnp1. Here we report identification of five fission yeast centromere proteins, Mis14-18. Mis14 is recruited to kinetochores independently of CENP-A, and, conversely, CENP-A does not require Mis14 to associate with centromeres. In contrast, Mis15, Mis16 (strong similarity with human RbAp48 and RbAp46), Mis17, and Mis18 are all part of the CENP-A recruitment pathway. Mis15 and Mis17 form an evolutionarily conserved complex that also includes Mis6. Mis16 and Mis18 form a complex and maintain the deacetylated state of histones specifically in the central core of centromeres. Mis16 and Mis18 are the most upstream factors in kinetochore assembly as they can associate with kinetochores in all kinetochore mutants except for mis18 and mis16, respectively. RNAi knockdown in human cells shows that Mis16 function is conserved as RbAp48 and RbAp46 are both required for localization of human CENP-A.
|
What is the function of the Mis18 protein?
|
In contrast, Mis15, Mis16 (strong similarity with human RbAp48 and RbAp46), Mis17, and Mis18 are all part of the CENP-A recruitment pathway.
|
Multiple sclerosis (MS) is the most common CNS-demyelinating disease of humans, showing clinical and pathological heterogeneity and a general resistance to therapy. We first discovered that abnormal myelin hypercitrullination, even in normal-appearing white matter, by peptidylarginine deiminases (PADs) correlates strongly with disease severity and might have an important role in MS progression. Hypercitrullination is known to promote focal demyelination through reduced myelin compaction. Here we report that 2-chloroacetamidine (2CA), a small-molecule, PAD active-site inhibitor, dramatically attenuates disease at any stage in independent neurodegenerative as well as autoimmune MS mouse models. 2CA reduced PAD activity and protein citrullination to pre-disease status. In the autoimmune models, disease induction uniformly induced spontaneous hypercitrullination with citrulline+ epitopes targeted frequently. 2CA rapidly suppressed T cell autoreactivity, clearing brain and spinal cord infiltrates, through selective removal of newly activated T cells. 2CA essentially prevented disease when administered before disease onset or before autoimmune induction, making hypercitrullination, and specifically PAD enzymes, a therapeutic target in MS models and thus possibly in MS.
|
List diseases where protein citrullination plays an important role.
|
We first discovered that abnormal myelin hypercitrullination, even in normal-appearing white matter, by peptidylarginine deiminases (PADs) correlates strongly with disease severity and might have an important role in MS progression.
|
The PAUSE software has been developed as a new tool to study translational control over protein targeting. This makes it possible to correlate the position of clusters of rare codons in a gene, predicted to cause a translational pause, with the position of hydrophobic stretches in the encoded protein, predicted to span a membrane or to act as a cleavable signal for targeting to the secretory pathway. Furthermore, this software gathers these correlations over whole sets of genes. The PAUSE software is described here, and its use is illustrated on a set of membrane proteins from the fungus Emericella nidulans. Preferential distances of about 45 codons and of about 70 codons between putative transmembrane domains and predicted translational pauses were observed. Given that approximately 30 residues are required to span the large ribosomal subunit, the predicted pauses would therefore occur when the hydrophobic domain starts protruding from the ribosome ('+45 pause'), or fully protrudes as a hairpin ('+70 pause'). Thus, these specific pauses might reflect a translational control over membrane protein targeting or early recognition ('+45 pause'), and over insertion or folding ('+70 pause').
|
Which are currently available software tools for detecting rare codon clusters in coding sequences?
|
The PAUSE software has been developed as a new tool to study translational control over protein targeting. This makes it possible to correlate the position of clusters of rare codons in a gene, predicted to cause a translational pause, with the position of hydrophobic stretches in the encoded protein, predicted to span a membrane or to act as a cleavable signal for targeting to the secretory pathway.
|
Transforming growth factor-beta1 (TGF-beta1) has central functions in development, tissue maintenance, and repair and has been implicated in major diseases. We discovered that TGF-beta1 contains several amphipathic helices and hydrophobic domains similar to apolipoprotein E (apoE), a protein involved in lipoprotein metabolism. Indeed, TGF-beta1 associates with lipoproteins isolated from human plasma, cultured liver cells, or astrocytes, and its bioactivity was highest in high-density lipoprotein preparations. Importantly, lipoproteins containing the apoE3 isoform had higher TGF-beta levels and bioactivity than those containing apoE4, a major genetic risk factor for atherosclerosis and Alzheimer's disease. Because TGF-beta1 can be protective in these diseases an association with apoE3 may be beneficial. Association of TGF-beta with different types of lipoproteins may facilitate its diffusion, regulate signaling, and offer additional specificity for this important growth factor.
|
Which ApoE isoform is associated with atherosclerosis and Alzheimer's disease?
|
Importantly, lipoproteins containing the apoE3 isoform had higher TGF-beta levels and bioactivity than those containing apoE4, a major genetic risk factor for atherosclerosis and Alzheimer's disease.
|
Prior to the emergence of antigenically distinct SARS-CoV-2 variants, reinfections were reported infrequently - presumably due to the generation of durable and protective immune responses. However, case reports also suggested that rare, repeated infections may occur as soon as 48 days following initial disease onset. The underlying immunologic deficiencies enabling SARS-CoV-2 reinfections are currently unknown. Here we describe a renal transplant recipient who developed recurrent, symptomatic SARS-CoV-2 infection - confirmed by whole virus genome sequencing - 7 months after primary infection. To elucidate the immunological mechanisms responsible for SARS-CoV-2 reinfection, we performed longitudinal profiling of cellular and humoral responses during both primary and recurrent SARS-CoV-2 infection. We found that the patient responded to the primary infection with transient, poor-quality adaptive immune responses. The patient's immune system was further compromised by intervening treatment for acute rejection of the renal allograft prior to reinfection. Importantly, we also identified the development of neutralizing antibodies and the formation of humoral memory responses prior to SARS-CoV-2 reinfection. However, these neutralizing antibodies failed to confer protection against reinfection, suggesting that additional factors are required for efficient prevention of SARS-CoV-2 reinfection. Further, we found no evidence supporting viral evasion of primary adaptive immune responses, suggesting that susceptibility to reinfection may be determined by host factors rather than pathogen adaptation in this patient. In summary, our study suggests that a low neutralizing antibody presence alone is not sufficient to confer resistance against reinfection. Thus, patients with solid organ transplantation, or patients who are otherwise immunosuppressed, who recover from infection with SARS-CoV-2 may not develop sufficient protective immunity and are at risk of reinfection.
|
Can reinfection occur after SARS-CoV-2 infection?
|
Prior to the emergence of antigenically distinct SARS-CoV-2 variants, reinfections were reported infrequently - presumably due to the generation of durable and protective immune responses.
|
Chronic isolation of adult animals represents a form of psychological stress that produces sympatho-adrenomedullar activation. Exercise training acts as an important modulator of sympatho-adrenomedullary system. This study aimed to investigate physical exercise-related changes in gene expression of catecholamine biosynthetic enzymes (tyrosine hydroxylase, dopamine-ß-hydroxylase and phenylethanolamine N-methyltransferase) and cyclic adenosine monophosphate response element-binding (CREB) in the adrenal medulla, concentrations of catecholamines and corticosterone (CORT) in the plasma and the weight of adrenal glands of chronically psychosocially stressed adult rats exposed daily to 20 min treadmill running for 12 weeks. Also, we examined how additional acute immobilization stress changes the mentioned parameters. Treadmill running did not result in modulation of gene expression of catecholamine synthesizing enzymes and it decreased the level of CREB mRNA in the adrenal medulla of chronically psychosocially stressed adult rats. The potentially negative physiological adaptations after treadmill running were recorded as increased concentrations of catecholamines and decreased morning CORT concentration in the plasma, as well as the adrenal gland hypertrophy of chronically psychosocially stressed rats. The additional acute immobilization stress increases gene expression of catecholamine biosynthetic enzymes in the adrenal medulla, as well as catecholamines and CORT levels in the plasma. Treadmill exercise does not change the activity of sympatho-adrenomedullary system of chronically psychosocially stressed rats.
|
Which enzymes synthesize catecholamines in adrenal glands?
|
This study aimed to investigate physical exercise-related changes in gene expression of catecholamine biosynthetic enzymes (tyrosine hydroxylase, dopamine-ß-hydroxylase and phenylethanolamine N-methyltransferase) and cyclic adenosine monophosphate response element-binding (CREB) in the adrenal medulla, concentrations of catecholamines and corticosterone (CORT) in the plasma and the weight of adrenal glands of chronically psychosocially stressed adult rats exposed daily to 20 min treadmill running for 12 weeks.
|
Electrically-induced twitch responses of the prostatic segment of vas deferens (0.1 Hz, 65 V, 1 ms) are mainly due to the transient presynaptic release of ATP, which acts postsynaptically on non-adrenergic receptors to contract smooth muscle cells. These responses were fully blocked by nanomolar concentrations of the omega-conotoxins GVIA, MVIIA, and MVIIC, most likely by inhibiting Ca2+ entry through presynaptic N-type Ca2+ channels controlling the release of ATP. Repeated washout of the toxins allowed the recovery of contractions, except for omega-conotoxin GVIA, whose inhibitory effects remained unchanged for at least 60 min. In addition, micromolar concentrations of omega-conotoxin MVIIC were unable to protect against the irreversible inhibition of twitch contractions induced by nanomolar concentrations of omega-conotoxin GVIA. At low extracellular Ca2+ concentrations (1.5 mM), 20 nM of omega-conotoxin GVIA or MVIIA inhibited completely the twitch contractions in about 10 min. In 5 mM Ca2+ the blockade of twitch contractions after 10 min was 70% for both toxins. In 1.5 mM Ca2+ omega-conotoxin MVIIC (1 microM) inhibited completely the twitch contraction after 10 min. In 5 mM Ca2+ blockade developed very slowly and was very poor after 30 min, omega-conotoxin MVIIC depressed the response by only 20%. These results are compatible with the idea that the three omega-conotoxins block the purinergic neurotransmission of the vas deferens by acting on presynaptic N-type voltage-dependent Ca2+ channels. However, omega-conotoxin MVIIC seems to bind to sites different from those recognised by omega-conotoxin GVIA and MVIIA, which are markedly differentiated by their Ca2+ requirements for binding to their receptors.
|
Does MVIIA and MVIIC bind to the same calcium channel?
|
omega-conotoxin MVIIC seems to bind to sites different from those recognised by omega-conotoxin GVIA and MVIIA,
|
Pro-social effects of oxytocin and its homologues are well-documented in birds and mammals. However, in fishes, the effect of isotocin, the homologue of oxytocin, on social behaviour is less clear. Studies in fishes have generally shown no effect of isotocin on social behaviours or even an anti-social effect. In our study, we measured association preference for conspecifics in 92 adult guppies (46 females and 46 males), half of which were injected with isotocin and the other half with an isotocin antagonist. We found that individuals injected with isotocin spent 29% more time associating with conspecifics than individuals injected with an isotocin antagonist. The effect of isotocin on association time did not differ between males and females. Our study provides some of the first evidence of a pro-social effects of isotocin in a fish and suggests that in fishes, isotocin may have a homologous role to oxytocin, at least in promoting shoaling behaviour.
|
Isotocin is an homolog of what hormone?
|
However, in fishes, the effect of isotocin, the homologue of oxytocin, on social behaviour is less clear
|
The objective of this review is to summarize data from the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation (ARISTOTLE) and Apixaban Versus Acetylsalicylic Acid to Prevent Stroke in Atrial Fibrillation Patients Who Have Failed or Are Unsuitable for Vitamin K Antagonist Treatment (AVERROES) trials of apixaban for stroke prevention in patients with atrial fibrillation (AF). The ARISTOTLE trial compared apixaban with warfarin in 18 201 patients with AF and ≥ 1 additional risk factor for stroke. The AVERROES trial compared apixaban with aspirin in 5599 patients with AF who were at increased risk of stroke and for whom vitamin K antagonists were unsuitable. In ARISTOTLE, apixaban reduced the risk of stroke or systemic embolism by 21% compared with warfarin (1.27% vs 1.60% per year; hazard ratio, 0.79; 95% confidence interval, 0.66-0.95). The reduction was significant and demonstrated the superiority of apixaban over warfarin for the primary outcome of preventing stroke or systemic embolism (P = 0.01 for superiority). Apixaban also reduced all-cause mortality by 11% (P = 0.047) and major bleeding by 31% (P < 0.001) compared with warfarin. The benefits of apixaban observed in ARISTOTLE are further supported by the results from AVERROES, which demonstrated a 55% reduction in the risk of stroke or systemic embolism compared with aspirin. Risk of major bleeding was not significantly different between apixaban and aspirin. Subgroup analyses in both trials demonstrated that the effects of apixaban are highly consistent across various patient subpopulations. Discontinuation of study medication was significantly lower with apixaban than with either warfarin in ARISTOTLE or aspirin in AVERROES. Apixaban is the first new oral anticoagulant that has been shown to be superior to warfarin in reducing stroke or systemic embolism, all-cause mortality, and major bleeding in patients with AF. Moreover, in patients with AF who are considered unsuitable for warfarin therapy, apixaban was more effective than aspirin for stroke prevention and had a similar rate of major bleeding.
|
Which two drugs were compared in the ARISTOTLE Trial?
|
The ARISTOTLE trial compared apixaban with warfarin in 18 201 patients with AF and ≥ 1 additional risk factor for stroke.
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.