question
stringlengths 13
215
| ground_truth
stringlengths 2
3.15k
| context
stringlengths 0
157k
|
|---|---|---|
Which was the first adeno-associated virus vector gene therapy product approved in the United States? | The first adeno-associated virus vector gene therapy product in the United States was Luxturna. | Recent clinical trials have demonstrated the potential of adeno-associated virus
(AAV)-based vectors for treating rare diseases. However, significant barriers
remain for the translation of these vectors into widely available therapies. In
particular, exposure to the AAV capsid can generate an immune response of
neutralizing antibodies. One approach to overcome this response is to map the
AAV-specific neutralizing epitopes and rationally design an AAV capsid able to
evade neutralization. To accomplish this, we isolated a monoclonal antibody
against AAV9 following immunization of BALB/c mice and hybridoma screening. This
antibody, PAV9.1, is specific for intact AAV9 capsids and has a high
neutralizing titer of >1:160,000. We used cryo-electron microscopy to
reconstruct PAV9.1 in complex with AAV9. We then mapped its epitope to the
3-fold axis of symmetry on the capsid, specifically to residues 496-NNN-498 and
588-QAQAQT-592. Capsid mutagenesis demonstrated that even a single amino acid
substitution within this epitope markedly reduced binding and neutralization by
PAV9.1. In addition, in vivo studies showed that mutations in the PAV9.1 epitope
conferred a "liver-detargeting" phenotype to the mutant vectors, unlike AAV9,
indicating that the residues involved in PAV9.1 interactions are also
responsible for AAV9 tropism. However, we observed minimal changes in binding
and neutralizing titer when we tested these mutant vectors for evasion of
polyclonal sera from mice, macaques, or humans previously exposed to AAV. Taken
together, these studies demonstrate the complexity of incorporating mapped
neutralizing epitopes and previously identified functional motifs into the
design of novel capsids able to evade immune response.IMPORTANCE Gene therapy
utilizing viral vectors has experienced recent success, culminating in U.S. Food
and Drug Administration approval of the first adeno-associated virus vector gene
therapy product in the United States: Luxturna for inherited retinal dystrophy.
However, application of this approach to other tissues faces significant
barriers. One challenge is the immune response to viral infection or vector
administration, precluding patients from receiving an initial or readministered
dose of vector, respectively. Here, we mapped the epitope of a novel
neutralizing antibody generated in response to this viral vector to design a
next-generation capsid to evade immune responses. Epitope-based mutations in the
capsid interfered with the binding and neutralizing ability of the antibody but
not when tested against polyclonal samples from various sources. Our results
suggest that targeted mutation of a greater breadth of neutralizing epitopes
will be required to evade the repertoire of neutralizing antibodies responsible
for blocking viral vector transduction. |
What is known about the gene MIR140? | Chondrocyte-specific microRNA-140 regulates endochondral bone development and targets Dnpep to modulate bone morphogenetic protein signaling.
Our findings showed the novel transcriptional role of miR140-5p in the expression of Nrf2 and miR-140-5p protected against Cisplatin induced oxidative stress by activating Nrf2-dependent antioxidant pathway, providing a potentially therapeutic target in acute kidney injury. | MicroRNAs (miRNAs) play critical roles in a variety of biological processes in
diverse organisms, including mammals. In the mouse skeletal system, a global
reduction of miRNAs in chondrocytes causes a lethal skeletal dysplasia. However,
little is known about the physiological roles of individual miRNAs in
chondrocytes. The miRNA-encoding gene, Mir140, is evolutionarily conserved among
vertebrates and is abundantly and almost exclusively expressed in chondrocytes.
In this paper, we show that loss of Mir140 in mice causes growth defects of
endochondral bones, resulting in dwarfism and craniofacial deformities.
Endochondral bone development is mildly advanced due to accelerated hypertrophic
differentiation of chondrocytes in Mir140-null mice. Comparison of profiles of
RNA associated with Argonaute 2 (Ago2) between wild-type and Mir140-null
chondrocytes identified Dnpep as a Mir140 target. As expected, Dnpep expression
was increased in Mir140-null chondrocytes. Dnpep overexpression showed a mild
antagonistic effect on bone morphogenetic protein (BMP) signaling at a position
downstream of Smad activation. Mir140-null chondrocytes showed lower-than-normal
basal BMP signaling, which was reversed by Dnpep knockdown. These results
demonstrate that Mir140 is essential for normal endochondral bone development
and suggest that the reduced BMP signaling caused by Dnpep upregulation plays a
causal role in the skeletal defects of Mir140-null mice. Runx2 and Axin2 regulate skeletal development. We recently determined that Axin2
and Runx2 molecularly interact in differentiating osteoblasts to regulate
intramembranous bone formation, but the relationship between these factors in
endochondral bone formation was unresolved. To address this, we examined the
effects of Axin2 deficiency on the cleidocranial dysplasia (CCD) phenotype of
Runx2(+/-) mice, focusing on skeletal defects attributed to improper
endochondral bone formation. Axin2 deficiency unexpectedly exacerbated calvarial
components of the CCD phenotype in the Runx2(+/-) mice; the endocranial layer of
the frontal suture, which develops by endochondral bone formation, failed to
mineralize in Axin2(-/-):Runx2(+/-) mice, resulting in a cartilaginous, fibrotic
and larger fontanel than observed in Runx2(+/-) mice. Transcripts associated
with cartilage development (e.g., Acan, miR140) were expressed at higher levels,
whereas blood vessel morphogenesis transcripts (e.g., Slit2) were suppressed in
Axin2(-/-):Runx2(+/-) calvaria. Cartilage maturation was impaired, as primary
chondrocytes from double mutant mice demonstrated delayed differentiation and
produced less calcified matrix in vitro. The genetic domice of Runx2 was also
reflected during endochondral fracture repair, as both Runx2(+/-) and double
mutant Axin2(-/-):Runx2(+/-) mice had enlarged fracture calluses at early stages
of healing. However, by the end stages of fracture healing, double mutant
animals diverged from the Runx2(+/-) mice, showing smaller calluses and
increased torsional strength indicative of more rapid end stage bone formation
as seen in the Axin2(-/-) mice. Taken together, our data demonstrate a domit
role for Runx2 in chondrocyte maturation, but implicate Axin2 as an important
modulator of the terminal stages of endochondral bone formation. |
Which gene therapy treatment is FDA approved for retinal dystrophy? | Luxturna is approved by the Food and Drug Administration (FDA) for the treatment of inherited retinal dystrophy. | Recent clinical trials have demonstrated the potential of adeno-associated virus
(AAV)-based vectors for treating rare diseases. However, significant barriers
remain for the translation of these vectors into widely available therapies. In
particular, exposure to the AAV capsid can generate an immune response of
neutralizing antibodies. One approach to overcome this response is to map the
AAV-specific neutralizing epitopes and rationally design an AAV capsid able to
evade neutralization. To accomplish this, we isolated a monoclonal antibody
against AAV9 following immunization of BALB/c mice and hybridoma screening. This
antibody, PAV9.1, is specific for intact AAV9 capsids and has a high
neutralizing titer of >1:160,000. We used cryo-electron microscopy to
reconstruct PAV9.1 in complex with AAV9. We then mapped its epitope to the
3-fold axis of symmetry on the capsid, specifically to residues 496-NNN-498 and
588-QAQAQT-592. Capsid mutagenesis demonstrated that even a single amino acid
substitution within this epitope markedly reduced binding and neutralization by
PAV9.1. In addition, in vivo studies showed that mutations in the PAV9.1 epitope
conferred a "liver-detargeting" phenotype to the mutant vectors, unlike AAV9,
indicating that the residues involved in PAV9.1 interactions are also
responsible for AAV9 tropism. However, we observed minimal changes in binding
and neutralizing titer when we tested these mutant vectors for evasion of
polyclonal sera from mice, macaques, or humans previously exposed to AAV. Taken
together, these studies demonstrate the complexity of incorporating mapped
neutralizing epitopes and previously identified functional motifs into the
design of novel capsids able to evade immune response.IMPORTANCE Gene therapy
utilizing viral vectors has experienced recent success, culminating in U.S. Food
and Drug Administration approval of the first adeno-associated virus vector gene
therapy product in the United States: Luxturna for inherited retinal dystrophy.
However, application of this approach to other tissues faces significant
barriers. One challenge is the immune response to viral infection or vector
administration, precluding patients from receiving an initial or readministered
dose of vector, respectively. Here, we mapped the epitope of a novel
neutralizing antibody generated in response to this viral vector to design a
next-generation capsid to evade immune responses. Epitope-based mutations in the
capsid interfered with the binding and neutralizing ability of the antibody but
not when tested against polyclonal samples from various sources. Our results
suggest that targeted mutation of a greater breadth of neutralizing epitopes
will be required to evade the repertoire of neutralizing antibodies responsible
for blocking viral vector transduction. |
Salivary Cortisol is a biomarker for what disease/syndrome/condition? | Salivary cortisone , as a biomarker for psychosocial stress , is associated with state anxiety and heart rate .
ortisol as a stress biomarker | Salivary cortisol is frequently used as a biomarker of psychological stress.
However, psychobiological mechanisms, which trigger the
hypothalamus-pituitary-adrenal axis (HPAA) can only indirectly be assessed by
salivary cortisol measures. The different instances that control HPAA reactivity
(hippocampus, hypothalamus, pituitary, adrenals) and their respective
modulators, receptors, or binding proteins, may all affect salivary cortisol
measures. Thus, a linear relationship with measures of plasma ACTH and cortisol
in blood or urine does not necessarily exist. This is particularly true under
response conditions. The present paper addresses several psychological and
biological variables, which may account for such dissociations, and aims to help
researchers to rate the validity and psychobiological significance of salivary
cortisol as an HPAA biomarker of stress in their experiments. Cortisol is a classical biomarker for the stress levels of human beings. We
fabricated highly sensitive bioluminescent probes for salivary cortisol. The
following strategies were contrived in the molecular design. Gaussia princeps
luciferase (GLuc) was dissected into two fragments, between which an
N-terminal-extended ligand binding domain of glucocorticoid receptor (GR HLBD),
named Simgr4, was inserted. First, this unique single-chain probe was then
situated downstream of a glucocorticoid response element (GRE) promoter in a
reporter-gene system for constructing two ON-OFF switches for cortisol. Second,
a circularly permutated (CP) variant of Simgr4 was formulated. The reporter-gene
system exerted an improved signal-to-background (S/B) ratio of 8.5 to cortisol.
Furthermore, a circularly permutated (CP) variant of Simgr4 exerted a 10×
enhanced detection limit to cortisol and a long dynamic range from 10(-9) to
10(-6) M cortisol, covering all of the normal clinical ranges of serum, urine,
and saliva. This optimized probe successfully determined daily fluctuations of
salivary cortisol and the correlations with those by ELISA. This study is the
first to investigate the contribution of the HLBD of a nuclear receptor and
multiple ON-OFF switches for molecular probes and salivary cortisols. The utility of measuring salivary cortisol has become increasingly appreciated
since the early 1980s. Salivary cortisol is a measure of active free cortisol
and follows the diurnal rhythm of serum or plasma cortisol. The saliva sample
may be collected by drooling or through the use of absorbent swabs which are
placed into the mouth until saturated. Salivary cortisol is therefore convenient
for patients and research participants to collect noninvasively on an outpatient
basis. Several assay techniques have been used to measure salivary cortisol,
including radioimmunoassay and more recently liquid chromatography-tandem mass
spectrometry. The analytical sensitivity varies between these assay methods, as
does the potential for cross-reactivity with other steroids. The interpretation
of salivary cortisol levels relies on rigorous standardization of sampling
equipment, sampling protocols and assay technology with establishment of a local
reference range. Clinically, the commonest use for salivary cortisol is
measuring late-night salivary cortisol as a screening test for Cushing's
syndrome. Several studies have shown diagnostic sensitivities and specificities
of over 90%, which compares very favourably with other screening tests for
Cushing's syndrome such as the 24-h urinary-free cortisol and the 1-mg overnight
dexamethasone suppression test. There are emerging roles for the use of salivary
cortisol in diagnosing adrenal insufficiency, particularly in conditions
associated with low cortisol-binding globulin levels, and in the monitoring of
glucocorticoid replacement. Finally, salivary cortisol has been used extensively
as a biomarker of stress in a research setting, especially in studies examining
psychological stress with repeated measurements. Salivary cortisol is commonly used as a clinical biomarker of endocrine status
and also as a marker of psychosocial stress. Annexin-A1 (AnxA1) is an
anti-inflammatory protein whose expression is modulated by glucocorticoids. Our
principal objectives were to (i) detect the presence of and (ii) measure AnxA1
protein in whole human saliva and to (iii) investigate whether salivary cortisol
and AnxA1 are correlated in healthy humans. A total of 37 healthy participants
(male and female) were used in the study. Saliva was collected using salivette
tubes. Salivary cortisol and AnxA1 protein were sampled at between 3 and 6 time
points over 24h and measured for cortisol and AnxA1 protein using specific
ELISA's. The presence of salivary AnxA1 protein was confirmed by Western
blotting. AnxA1 protein is detectable in whole human saliva, as detected by
Western blot analysis and ELISA. A diurnal rhythm was evident in both salivary
cortisol (P<0.01) and AnxA1 (P<0.01) and was defined as a significant difference
in time 0 (waking) samples compared to 'bed' (2300 h) samples. AnxA1 protein did
not exhibit an awakening response (P>0.05), whereas salivary cortisol was
significantly elevated between time 0 and 30 min post waking (P<0.001). AnxA1
protein correlates positively with salivary cortisol, indicating that cortisol
is most likely a regulator of AnxA1 in human saliva. PURPOSE: Psychological stress has been suggested to result in hormonal effects
(e.g. changes in cortisol pattern) that may change food selection in unhealthy
ways. This study examines whether children's dietary pattern is indeed related
to salivary cortisol levels.
METHODS: In 323 children (5-10 years old) participating in the Belgian ChiBS
study, salivary cortisol samples, a biomarker for stress, was sampled when
waking up, 30 and 60 min after wake up and in the evening on two consecutive
weekdays. Data on the children's dietary pattern (frequency of sweet foods,
fatty foods, snacks, fruit and vegetables) was collected with a food frequency
questionnaire. Multilevel time modelling was used with adjustments for sex, age,
body mass index, parental education and wake up time.
RESULTS: Higher overall cortisol levels and a large cortisol awakening response
(CAR) were associated with more frequent consumption of sweet foods. A steeper
diurnal cortisol decline was associated with a higher sweet, fatty and snack
food consumption frequency. No associations with fruit and vegetables
consumption were found.
CONCLUSIONS: High cortisol levels were linked to an unhealthier dietary pattern
(more fatty food, snacks and especially sweet food). This supports the theory of
cortisol-induced comfort food preference and strengthens the stress-diet
relation. PURPOSE: Cortisol is frequently assayed as a stress-responsive biomarker which
changes over the course of minutes to meet the demands of a person's social
context. Salivary cortisol is often used as a noninvasive sampling method that
possesses important health implications. A critical barrier to psychobiological
research that involves salivary cortisol is a time delay of days to months
before cortisol results are obtained via immunoassay, long after the person is
no longer proximate to the social context in which they provided the sample. The
present study was designed to address this critical barrier through creation of
a lateral flow test (LFT) cortisol device capable of measuring salivary cortisol
within minutes of sample collection. The LFT is frequently used within
commercial point-of-care settings to obtain rapid answers to the
presence/absence of a biomarker. The present study extends the LFT into the
research domain by presenting performance characteristics of a quantitative LFT
that measures salivary cortisol within 20 minutes of sample collection.
METHODS: Saliva samples from 29 adults (15 men) were obtained in the morning and
afternoon by using Passive Drool and then the Super·SAL Extra Collection Device
(hereafter Super·SAL) and later assayed with LFT and a commercially available
enzyme immunoassay.
FINDINGS: Results indicate the LFT correlated well with these collection methods
(R = 0.872 with Super · SAL, R = 0.739 with Passive Drool, P < 0.0001) and at
comparable levels to correspondence of Super · SAL with Passive Drool (R =
0.798, P < 0.0001) which were measured with the same assay.
IMPLICATIONS: These results open an exciting new possibility to integrate this
technologic advance into stress research, including knowing and potentially
changing the person's social context in a time-sensitive manner. Methodological
improvements such as this have the possibility of refining conceptual models of
stress reactivity and regulation. OBJECTIVE: To investigate the influence of occupational stress on salivary
cortisol concentration in employees.
METHODS: In September 2014, occupational stress evaluation was performed for 186
employees in a solar photovoltaic company, and enzyme-linked immunosorbent assay
was used to measure the salivary cortisol concentration.
RESULTS: The salivary cortisol concentration showed no significant differences
between groups with different demographic features(P>0.05). The group with a
high score of job control had a significantly lower salivary cortisol
concentration than that with a low score(74.62±15.34 μg/L vs 79.95±12.99 μg/L,
P<0.05). The groups with high scores of job danger and job responsibility and
burden had significantly higher salivary cortisol concentrations than those with
low scores(80.29±9.45 μg/L vs 75.60±16.41, P<0.05; 80.94±10.87 μg/L vs
74.05±16.35 μg/L, P<0.05). The salivary cortisol concentration was positively
correlated with the scores of job danger and job responsibility and
burden(r=0.176 and 0.252, P<0.05) and negatively correlated with the score of
job control(r=-0.208, P<0.05).
CONCLUSION: Salivary cortisol concentration is positively correlated with
occupational stress and increases with the increasing degree of occupational
stress, and can be used as an objective biomarker for the identification and
evaluation of occupational stress. Salivary cortisol is considered to be a safe and noninvasive measure of
hypothalamic-pituitary-adrenal axis functioning, and is a commonly measured
biomarker of the human stress response in pediatric research. However, cortisol
is highly variable and sensitive to a wide range of factors, creating a
challenge for reliable salivary cortisol collection in the community setting.
Furthermore, the acceptability of salivary cortisol collection in community
samples of children is largely unknown. The purpose of this integrative review
was to investigate current evidence on the acceptability and feasibility of
salivary cortisol collection in community samples of children. In an analysis
framed by the Theory of Planned Behavior, data extracted from 31 studies
revealed six categories of psychosocial influences on acceptability and
feasibility: uncertainty and misconceptions, cultural and ethnic values, family
rules and values, difficulty following protocols and procedures, burden of
multiple samples, and child refusal or resistance. Further research is required
to fully understand the factors that influence acceptability and feasibility of
salivary cortisol collection in community samples of children. Understanding
individual, family, and community perceptions of biobehavioral research will
lead to more culturally sensitive and feasible community-based research methods.
© 2016 Wiley Periodicals, Inc. PURPOSE OF REVIEW: A resurgence of interest in salivary biomarkers has generated
evidence for their value in assessing adrenal function. The advantages of
salivary measurements include only free hormone is detected, samples can be
collected during normal daily routines and stress-induced cortisol release is
less likely to occur than during venepuncture. We review the use of salivary
biomarkers to diagnose and monitor patients for conditions of cortisol excess
and deficiency and discuss the value of measuring salivary cortisone versus
salivary cortisol.
RECENT FINDINGS: Developments in laboratory techniques have enabled the
measurement of salivary hormones with a high level of sensitivity and
specificity. In states of altered cortisol binding, salivary biomarkers are more
accurate measures of adrenal reserve than serum cortisol. Salivary cortisone is
a superior marker of serum cortisol compared with salivary cortisol,
specifically when serum cortisol is low and during hydrocortisone therapy when
contamination of saliva may result in misleading salivary cortisol
concentrations.
SUMMARY: Salivary cortisol and cortisone can be used to assess cortisol excess,
deficiency and hydrocortisone replacement, with salivary cortisone having the
advantage of detection when serum cortisol levels are low and there is no
interference from oral hydrocortisone. BACKGROUND: Stress activates the central nervous, the autonomic nervous, and the
endocrine system. This study aimed to (1) test the usability of salivary
cortisone in a standardized psychosocial stressor, (2) create a comprehensive
profile of hormonal responses to determine laboratory parameters with high
discriminatory power, and (3) analyze their association with psychometric and
autonomic stress measures.
METHODS: Healthy young men (18-35 years) completed either the Trier Social
Stress Test (TSST) (n = 33) or a Placebo-TSST (n = 34). Blood and saliva were
collected at 14 time points along with state-anxiety (STAI) and heart rate.
Serum steroids (cortisol*, cortisone*, dehydroepiandrosterone-sulfate,
androstenedione*, progesterone*, 17-hydroxyprogesterone*, testosterone,
estradiol*, aldosterone*), salivary cortisol* and cortisone*, copeptin*,
adrenocorticoptropic hormone*, corticosteroid-binding globulin, and salivary
alpha-amylase* were analyzed. We used mixed-design ANOVAs to test group
differences, receiver operator characteristic (ROC) curve analyses to assess the
discriminatory power of each measure, and Spearman correlation analyses to probe
the association between measures.
RESULTS: The largest area under the ROC curve was observed in salivary cortisone
at 20 min after the end of the TSST (AUC = 0.909 ± 0.044, p < 0.0001).
Significant time-by-group interactions were found in the parameters marked with
* above, indicating stress-induced increases. The peak response of salivary
cortisone was significantly associated with those of STAI (rho = 0.477,
p = 0.016) and heart rate (rho = 0.699, p < 0.0001) in the TSST group.
CONCLUSION: Our study found salivary cortisone to be a stress biomarker with
high discriminatory power and significant correlations with subjective and
autonomic stress measures. Our results can inform future stress studies of
sampling time for different laboratory parameters. INTRODUCTION: Cushing's syndrome is defined as chronic excess free cortisol in
circulation. According to recent studies, midnight salivary cortisol is an
accurate and non-stress method for screening and diagnosing Cushing's syndrome.
However, there is limited data on midnight salivary cortisol for diagnosing
Cushing's syndrome in the Chinese population.
METHODS: Among 61 suspected Chinese patients, 48 patients were confirmed to have
Cushing's syndrome. We evaluated the midnight salivary cortisol, midnight serum
cortisol and 24-hour urine free cortisol excretion for diagnosis. Midnight
salivary cortisol was collected from 21 healthy volunteers for control purposes.
RESULTS: In the patient group, mean urine free cortisol excretion and midnight
salivary cortisol levels were 296.50 ± 47.99 µg/day and 10.18 ± 1.29 ng/mL,
respectively. Among the control group and normal participants, mean midnight
salivary cortisol level was 0.53 ± 0.13 ng/mL and 0.50 ± 0.12 ng/mL,
respectively. The cut-off value for midnight salivary cortisol was 1.7 ng/mL for
diagnosing Cushing's syndrome, with a sensitivity of 98% and specificity of
100%. The diagnostic performance of midnight salivary cortisol (area under the
curve [AUC] = 0.99) was superior to that of urine free cortisol (AUC = 0.89).
CONCLUSION: Our study confirmed the good diagnostic performance of midnight
salivary cortisol for diagnosing Cushing's syndrome in a Chinese population.
Correlation between midnight salivary cortisol and either urine free cortisol or
midnight serum cortisol was good. Midnight salivary cortisol is a convenient and
precise tool for diagnosing Cushing's syndrome and can be the screening test of
choice for Chinese populations. |
What is the function of the cGAS pathway? | The cGAS-STING pathway not only mediates protective immune defense against infection by a large variety of DNA-containing pathogens but also detects tumor-derived DNA and generates intrinsic antitumor immunity. | Author information:
(1)Adjuvant Research Group, School of Biochemistry and Immunology, Trinity
Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, D02 PN40,
Ireland.
(2)Centre for Immunology and Microbial Disease, Albany Medical College, 47 New
Scotland Avenue, MC 151, Albany, NY 12208, USA.
(3)Statens Serum Institut, Department of Infectious Disease Immunology,
Artillerivej 5, 2300 Copenhagen S, Denmark.
(4)School of Biochemistry and Immunology and Trinity College Institute of
Neuroscience, Trinity College Dublin, Dublin 2, D02 PN40, Ireland.
(5)Centre for Innate Immunity and Infectious Diseases, MIMR-PHI and Department
of Molecular and Translational Sciences, Monash University, Clayton, VIC 3068,
Australia.
(6)Program in Innate Immunity, Division of Infectious Diseases and Immunology,
Department of Medicine, University of Massachusetts Medical School, Worcester,
MA, 01605, USA; Centre of Molecular Inflammation Research, Department of Cancer
Research and Molecular Medicine, Norwegian University of Science and Technology,
7491 Trondheim, Norway.
(7)Viral Immune Evasion Group, School of Biochemistry and Immunology, Trinity
Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, D02 PN40,
Ireland.
(8)Adjuvant Research Group, School of Biochemistry and Immunology, Trinity
Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, D02 PN40,
Ireland; Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN)
& Advanced Materials Bio-Engineering Research Centre (AMBER), Trinity College
Dublin, Dublin 2, D02 PN40, Ireland. Electronic address: [email protected]. cGMP-AMP (cGAMP) synthase (cGAS) is a cytosolic DNA sensor that activates innate
immune responses. cGAS catalyzes the synthesis of cGAMP, which functions as a
second messenger that binds and activates the adaptor protein STING to induce
type I interferons (IFNs) and other immune modulatory molecules. Here we show
that cGAS is indispensable for the antitumor effect of immune checkpoint
blockade in mice. Wild-type, but not cGAS-deficient, mice exhibited slower
growth of B16 melanomas in response to a PD-L1 antibody treatment. Consistently,
intramuscular delivery of cGAMP inhibited melanoma growth and prolonged the
survival of the tumor-bearing mice. The combination of cGAMP and PD-L1 antibody
exerted stronger antitumor effects than did either treatment alone. cGAMP
treatment activated dendritic cells and enhanced cross-presentation of
tumor-associated antigens to CD8 T cells. These results indicate that activation
of the cGAS pathway is important for intrinsic antitumor immunity and that cGAMP
may be used directly for cancer immunotherapy. Author information:
(1)Gene Expression Laboratory, The Salk Institute for Biological Studies, La
Jolla, California 92037, USA.
(2)Universidad Católica de Murcia (UCAM), Campus de los Jerónimos, 135,
Guadalupe 30107, Spain.
(3)Research Center for Tumor Medical Science, Graduate Institute of Cancer
Biology, China Medical University, Taichung 40402, Taiwan.
(4)Department of Dental Hygiene, China Medical University, Taichung 40402,
Taiwan.
(5)Department of Pathology, National Defense Medical Centre and Tri-Service
General Hospital, Taipei 114, Taiwan.
(6)Flow Cytometry Core Facility, The Salk Institute for Biological Studies, La
Jolla, California 92037, USA.
(7)Graduate Institute of Life Sciences, National Defense Medical Center, Taipei,
Taiwan.
(8)Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for
Biological Studies, La Jolla, California 92037, USA.
(9)Division of Biological Sciences, University of California, San Diego, La
Jolla, California 92037, USA.
(10)Department of Family Medicine and Public Health, University of California,
San Diego, La Jolla, California 92037, USA.
(11)Department of Otolaryngology-Head and Neck Surgery, National Defense Medical
Centre and Tri-Service General Hospital, Taipei 114, Taiwan.
(12)Department of Otolaryngology-Head and Neck Surgery, Kaohsiung Veterans
General Hospital, Kaohsiung 81362, Taiwan.
(13)Moores Cancer Center, University of California, San Diego, La Jolla,
California 92037, USA.
(14)Center for Microbiome Innovation, University of California, San Diego, La
Jolla, California 92037, USA. Cyclic di-AMP (c-di-AMP) is a bacterial signaling nucleotide synthesized by
several human pathogens. This widespread and specific bacterial product is
recognized by infected host cells to trigger an innate immune response.
Detection of c-di-AMP in the host cytosol leads primarily to the induction of
type I interferon via the STING-cGAS signaling axis, while being also entangled
in the activation of the NF-κB pathway. During their long-standing interaction,
host and pathogens have co-evolved to control c-di-AMP activation of innate
immunity. On the bacterial side, the quantity of c-di-AMP released inside cells
allows to manipulate the host response to exacerbate infection by avoiding
immune recognition or, at the opposite, by overloading the STING-cGAS pathway. |
Does RUNX2 inhibit astrocyte differentiation? | No, RUNX2 promostes astrocyte differentiation. | Identification of cell-fate determits for directing stem cell differentiation
remains a challenge. Moreover, little is known about how cell-fate determits
are regulated in functionally important subnetworks in large gene-regulatory
networks (i.e., GRN motifs). Here we propose a model of stem cell
differentiation in which cell-fate determits work synergistically to
determine different cellular identities, and reside in a class of GRN motifs
known as feedback loops. Based on this model, we develop a computational method
that can systematically predict cell-fate determits and their GRN motifs. The
method was able to recapitulate experimentally validated cell-fate determits,
and validation of two predicted cell-fate determits confirmed that
overexpression of ESR1 and RUNX2 in mouse neural stem cells induces neuronal and
astrocyte differentiation, respectively. Thus, the presented GRN-based model of
stem cell differentiation and computational method can guide differentiation
experiments in stem cell research and regenerative medicine. |
What are 5 key questions in human performance modeling? | There are five key questions of human performance modeling: 1) Why we build models of human performance; 2) What the expectations of a good human performance model are; 3) What the procedures and requirements in building and verifying a human performance model are; 4) How we integrate a human performance model with system design; and 5) What the possible future directions of human performance modeling research are. | Via building computational (typically mathematical and computer simulation)
models, human performance modeling (HPM) quantifies, predicts, and maximizes
human performance, human-machine system productivity and safety. This paper
describes and summarizes the five key questions of human performance modeling:
1) Why we build models of human performance; 2) What the expectations of a good
human performance model are; 3) What the procedures and requirements in building
and verifying a human performance model are; 4) How we integrate a human
performance model with system design; and 5) What the possible future directions
of human performance modeling research are. Recent and classic HPM findings are
addressed in the five questions to provide new thinking in HPM's motivations,
expectations, procedures, system integration and future directions. |
What is the mode of action of the Tc toxins? | The toxin complex (tc) genes of bacteria comprise a large and growing family whose mode of action remains obscure. Tc toxins are widely distributed among different gram-negative and gram-positive bacteria, where they act as pathogenicity factors. Tripartite Tc toxin complexes of bacterial pathogens perforate the host membrane and translocate toxic enzymes into the host cell, including in humans. The underlying mechanism is complex but poorly understood. | The toxin complex (tc) genes of Photorhabdus encode insecticidal, high molecular
weight Tc toxins. These toxins have been suggested as useful alternatives to
those derived from Bacillus thuringiensis for expression in insect-resistant
transgenic plants. Although Photorhabdus luminescens is symbiotic with nematodes
that kill insects, tc genes have recently been described from other
insect-associated bacteria such as Serratia entomophila, an insect pathogen, and
Yersinia pestis, the causative agent of bubonic plague, which has a flea vector.
Here, recent advances in our understanding of the tc gene family are reviewed in
view of their potential development as insect-control agents. The toxin complex (tc) genes of bacteria comprise a large and growing family
whose mode of action remains obscure. In the insect pathogen Photorhabdus, tc
genes encode high molecular weight insecticidal toxins with oral activity
against caterpillar pests. One protein, TcdA, has recently been expressed in
transgenic plants and shown to confer insect resistance. These toxins therefore
represent alternatives to toxins from Bacillus thuringiensis (Bt) for deployment
in transgenic crops. Levels of TcdA expression in transgenic plants were,
however, low and the full toxicity associated with the native toxin was not
reconstituted. Here we show that increased activity of the toxin TcdA1 requires
potentiation by either of two pairs of gene products, TcdB1 and TccC1 or TcdB2
and TccC3. Moreover, these same pairs of proteins can also cross-potentiate a
second toxin, TcaA1B1. To elucidate the likely functional domains present in
these large proteins, we expressed fragments of each 'toxin' or 'potentiator'
gene within mammalian cells. Several domains produced abnormal cellular
morphologies leading to cell death, while others showed specific phenotypes such
as nuclear translocation. Our results prove that the Tc toxins are complex
proteins with multiple functional domains. They also show that both toxin genes
and their potentiator pairs will need to be expressed to reconstitute full
activity in insect-resistant transgenic plants. Moreover, they suggest that the
same potentiator pair will be able to cross-potentiate more than one toxin in a
single plant. Tc toxins are widely distributed among different gram-negative and gram-positive
bacteria, where they act as pathogenicity factors. The toxins are composed of
different components that form oligomers for biological activity. Lipid bilayer
experiments were performed with the TcdA1 component of the Tc toxin from
Photorhabdus luminescens, which preferentially kills insects by actin
polymerization. TcdA1 was able to increase the specific conductance of
artificial lipid bilayer membranes by the formation of ion-permeable channels.
The channels had on average a single-channel conductance of 125 pS in 150 mM KCl
and were found to be cation selective. The single-channel conductance of the
TcdA1-channels was only moderately dependent on the bulk aqueous KCl
concentration, which indicated point-charge effects on the channel properties.
Experiments to study the voltage dependence of the TcdA1 channel demonstrated
that it is reconstituted in a fully oriented way when it is added to only one
side of the lipid bilayer membrane. A combination of biologically active
components (TccC3) and a possible chaperone (TcdB2) blocked the TcdA1-mediated
conductance efficiently in a dose-dependent manner when they were added to the
cis side of the membrane. The half-saturation constant for binding of
TcdB2-TccC3 to TcdA1 is in the low omolar range. Tripartite Tc toxin complexes of bacterial pathogens perforate the host membrane
and translocate toxic enzymes into the host cell, including in humans. The
underlying mechanism is complex but poorly understood. Here we report the first,
to our knowledge, high-resolution structures of a TcA subunit in its prepore and
pore state and of a complete 1.7 megadalton Tc complex. The structures reveal
that, in addition to a translocation channel, TcA forms four receptor-binding
sites and a neuraminidase-like region, which are important for its host
specificity. pH-induced opening of the shell releases an entropic spring that
drives the injection of the TcA channel into the membrane. Binding of TcB/TcC to
TcA opens a gate formed by a six-bladed β-propeller and results in a continuous
protein translocation channel, whose architecture and properties suggest a novel
mode of protein unfolding and translocation. Our results allow us to understand
key steps of infections involving Tc toxins at the molecular level. Tc toxins from pathogenic bacteria use a special syringe-like mechanism to
perforate the host cell membrane and inject a deadly enzyme into the host
cytosol. The molecular mechanism of this unusual injection system is poorly
understood. Using electron cryomicroscopy, we determined the structure of TcdA1
from Photorhabdus luminescens embedded in lipid odiscs. In our structure,
compared with the previous structure of TcdA1 in the prepore state, the
transmembrane helices rearrange in the membrane and open the initially closed
pore. However, the helices do not span the complete membrane; instead, the loops
connecting the helices form the rim of the funnel. Lipid head groups reach into
the space between the loops and consequently stabilize the pore conformation.
The linker domain is folded and packed into a pocket formed by the other domains
of the toxin, thereby considerably contributing to stabilization of the pore
state. Various bacterial toxins have potent insecticidal activity. Recently, the Toxin
complexes (Tc's) of Photorhabdus and Xenorhabdus species have become an
increased focus of current research. These large tripartite toxins with
molecular masses >1.4 megadaltons consist of three components termed A, B, and C
(or TcA, TcB, and TcC). While TcA is involved in receptor binding and toxin
translocation, TcC possesses the specific toxin enzyme activity and TcB is a
linker between components TcA and TcC. Here, a structure function analysis of
the toxins is described and the application of Tc toxins as potential
insecticides is discussed. Tc toxins secrete toxic enzymes into host cells using a unique syringe-like
injection mechanism. They are composed of three subunits, TcA, TcB and TcC. TcA
forms the translocation channel and the TcB-TcC heterodimer functions as a
cocoon that shields the toxic enzyme. Binding of the cocoon to the channel
triggers opening of the cocoon and translocation of the toxic enzyme into the
channel. Here we show in atomic detail how the assembly of the three components
activates the toxin. We find that part of the cocoon completely unfolds and
refolds into an alternative conformation upon binding. The presence of the toxic
enzyme inside the cocoon is essential for its subomolar binding affinity for
the TcA subunit. The enzyme passes through a narrow negatively charged
constriction site inside the cocoon, probably acting as an extruder that
releases the unfolded protein with its C terminus first into the translocation
channel. |
What does RUNX2 stand for? | Runt related factor-2 | |
Where, in the body, would the Cobb-Stainsby excision arthroplasty be performed? | The Cobb-Stainsby forefoot arthroplasty combines partial phalangectomy ( Stainsby ) with extensor tendon transfer to the metatarsal head ( Cobb ) . | BACKGROUND: Dislocated metatarsophalangeal joints from clawed or hammer toes can
be a disabling consequence of several conditions. The Cobb-Stainsby forefoot
arthroplasty combines partial phalangectomy (Stainsby) with extensor tendon
transfer to the metatarsal head (Cobb). We present a retrospective, three
surgeon case series of 215 toes in 126 patients.
METHODS: Early results and complications were gathered from the medical charts
of 126 patients who met the inclusion criteria. Seventy-five patients were
contactable by phone with a follow up range of 12-82 months (median follow up 45
months). Primary outcome measures were improvement of pain and function,
reduction in plantar callosities and cosmetic improvement of the deformity.
RESULTS: Pre-operatively all patients presented with pain and shoe wear
problems. Post-operatively seventy-two patients (96%) were satisfied, 72 (96%)
reported pain relief, 55 (73%) were happy with toe control, 61 (81%) were
pleased with cosmesis and 56 (75%) reported unlimited daily activities.
Superficial wound infections were observed in 13 of the 126 patients (10%) and
two in 75 patients (2%) developed recurrent clawing.
CONCLUSION: Our case series demonstrates improved outcomes over alternatives
such as the Weil's osteotomy. |
Are cardenolides inhibitors of Na+/K+ ATPase? | Yes,
Cardenolides have shown significant antitumor activity due to their ability to inhibit the Na+K+ATPase enzyme, and the expression of this enzyme is increased in tumor cells. | PREMISE OF THE STUDY: Pachypodium (Apocynaceae) is a genus of iconic
stem-succulent and poisonous plants endemic to Madagascar and southern Africa.
We tested hypotheses about the mode of action and macroevolution of toxicity in
this group. We further hypothesized that while monarch butterflies are highly
resistant to cardenolide toxins (a type of cardiac glycoside) from American
Asclepias, they may be negatively affected by Pachypodium defenses, which
evolved independently.
METHODS: We grew 16 of 21 known Pachypodium spp. and quantified putative
cardenolides by HPLC and also by inhibition of animal Na+ /K+ -ATPase (the
physiological target of cardiac glycosides) using an in vitro assay. Pachypodium
extracts were tested against monarch caterpillars in a feeding bioassay. We also
tested four Asclepias spp. and five Pachypodium spp. extracts, contrasting
inhibition of the cardenolide-sensitive porcine Na+ /K+ -ATPase to the monarch's
resistant form.
KEY RESULTS: We found evidence for low cardenolides by HPLC, but substantial
toxicity when extracts were assayed on Na+ /K+ -ATPases. Toxicity showed
phylogenetic signal, and taller species showed greater toxicity (this was
marginal after phylogenetic correction). Application of Pachypodium extracts to
milkweed leaves reduced monarch growth, and this was predicted by inhibition of
the sensitive Na+ /K+ -ATPase in phylogenetic analyses. Asclepias extracts were
100-fold less potent against the monarch compared to the porcine Na+ /K+
-ATPase, but this difference was absent for Pachypodium extracts.
CONCLUSIONS: Pachypodium contains potent toxicity capable of inhibiting
sensitive and cardenolide-adapted Na+ /K+ -ATPases. Given the monarch's
sensitivity to Pachypodium, we suggest that these plants contain novel cardiac
glycosides or other compounds that facilitate toxicity by binding to Na+ /K+
-ATPases. Cardenolides are plant-derived toxic substances. Their cytotoxicity and the
underlying mechanistic signaling axes have been extensively documented, but only
a few anti-viral activities of cardenolides and the associated signaling
pathways have been reported. Previously, we reported that a variety of
cardenolides impart anti-transmissible gastroenteritis coronavirus (TGEV)
activity in swine testicular (ST) cells, through targeting of the cell membrane
sodium/potassium pump, Na+/K+-ATPase. Herein, we further explore the potential
signaling cascades associated with this anti-TGEV activity in ST cells. Ouabain,
a representative cardenolide, was found to potently diminish TGEV titers and
inhibit the TGEV-induced production of IL-6 in a dose dependent manner, with 50%
inhibitory concentrations of 37 nM and 23 nM respectively. By pharmacological
inhibition and gene silencing, we demonstrated that PI3K_PDK1_RSK2 signaling was
induced in TGEV-infected ST cells, and ouabain imparted a degree of anti-TGEV
activity via further augmentation of this existing PI3K_PDK1 axis signaling, in
a manner dependent upon its association with the Na+/K+-ATPase. Finally,
inhibition of PI3K by LY294002 or PDK1 by BX795 antagonized the anti-viral
activity of ouabain and restored the TGEV virus titer and yields. This finding
is the first report of a PI3K_PDK1 signaling axis further induced by ouabain and
implicated in the suppression of TGEV activity and replication; greatly
illuminates the underlying mechanism of cardenolide toxicity; and is expected to
result in one or more anti-viral applications for the cardenolides in the
future. |
Can antisense threapy be used for Huntington's disease? | Yes, antisense oligonucleotide therapy has been shown to lower Huntingtin mRNA levels and be beneficial against Huntington's disease. | Lowering mutant Huntingtin is a consensus therapeutic strategy for Huntington's
disease. In this issue of Neuron, Kordasiewicz et al. (2012) show the benefit of
transient antisense oligonucleotide (ASO) therapy to degrade Huntingtin mRNA and
elicit sustained therapeutic benefit in HD mice. |
What are acoustic reported genes used to detect? | Acoustic reporter genes are genetic constructs that allow bacterial gene expression to be visualized in vivo using ultrasound. | The mammalian microbiome has many important roles in health and disease, and
genetic engineering is enabling the development of microbial therapeutics and
diagnostics. A key determit of the activity of both natural and engineered
microorganisms in vivo is their location within the host organism. However,
existing methods for imaging cellular location and function, primarily based on
optical reporter genes, have limited deep tissue performance owing to light
scattering or require radioactive tracers. Here we introduce acoustic reporter
genes, which are genetic constructs that allow bacterial gene expression to be
visualized in vivo using ultrasound, a widely available inexpensive technique
with deep tissue penetration and high spatial resolution. These constructs are
based on gas vesicles, a unique class of gas-filled protein ostructures that
are expressed primarily in water-dwelling photosynthetic organisms as a means to
regulate buoyancy. Heterologous expression of engineered gene clusters encoding
gas vesicles allows Escherichia coli and Salmonella typhimurium to be imaged
noninvasively at volumetric densities below 0.01% with a resolution of less than
100 μm. We demonstrate the imaging of engineered cells in vivo in
proof-of-concept models of gastrointestinal and tumour localization, and develop
acoustically distinct reporters that enable multiplexed imaging of cellular
populations. This technology equips microbial cells with a means to be
visualized deep inside mammalian hosts, facilitating the study of the mammalian
microbiome and the development of diagnostic and therapeutic cellular agents. |
What is a lipin 1 protein doing? | As a lipin family founding member, lipin1 exerts dual functions as a phosphatidate phosphatase enzyme and/or a co-transcriptional regulator in lipid metabolism. In fact, it is also involved in many other cell processes. | Conflict of interest statement: The authors thank Dr. Alan Pestronk and Dr.
Abhinav Diwan for technical assistance in interpreting histology, and Dennis J.
Dietzen for determining plasma creatine kinase (all from Washington University).
This work was supported by U.S. National Institutes of Health (NIH) National
Institute of Diabetes and Digestive and Kidney Diseases Grant R01 DK078187 and
NIH National Heart, Lung, and Blood Institute Grant R01 HL119225 (to B.N.F.).
G.G.S. was supported by NIH National Heart, Lung, and Blood Institute Grants T32
HL007275, T32 HL007081, and the Washington University Institute of Clinical and
Translational Sciences NIH Grant UL1 TR000448, Subaward KL2 TR000450, from the
National Center for Advancing Translational Sciences (NCATS). K.S.M. was
supported by NIH National Institute of Diabetes and Digestive and Kidney
Diseases Grant T32-DK007120. J.Y. was supported by Washington University
Institute of Clinical and Translational Sciences NIH Grant UL1 TR000448,
Subaward KL2 TR000450. T.E.H. and J.M.E. were supported by NIH National
Institute of Diabetes and Digestive and Kidney Diseases Grant R01 DK101946.
C.C.W. and S.K.P were supported by NIH National Institute on Aging Grant R01
AG031867. This work was also supported by the cores of the Washington University
Nutrition Obesity Research Center (Grant P30 DK56341), Diabetes Research Center
(DRC) (Grant P30 DK020579), the Metabolomics Facility at Washington University
(Grant P30 DK056341), and the Washington University NIH National Institute of
General Medical Sciences Biomedical Mass Spectrometry Resource (Grant P41
GM103422) to F.-F.H.; the Washington University Genome Technology Access Center
in the Department of Genetics (Grant P30 CA91842); and the Department of
Pathology DRC Electron Microscopy Facility (Grant P60 DK020579). The authors
declare no conflicts of interest. As a lipin family founding member, lipin1 exerts dual functions as a
phosphatidate phosphatase enzyme and/or a co-transcriptional regulator in lipid
metabolism. In fact, it is also involved in many other cell processes. In this
study, we utilized pull down assay coupled with mass spectrometry (MS) to
unravel protein-protein interaction networks of lipin1 in 293T human embryonic
kidney cells. Pull-down assay on the Ni2+ -chelating column was used to isolate
lipin1 complexes from 293T cells transfected with 6-His tagged lipin1. The
lipin1 complexes were analyzed on Q Exactive mass spectrometer. A total of 30
proteins were identified from label free quantitation of the MS data by Proteome
Discoverer platform. The physical interaction between lipin1 and eEF1A1 was
further affirmed in 293T cells transfected with 6-His tagged lipin1 and
hepatocyte SMMC7721 cells by protein immunoprecipitation and immunofluorescence
microscopy. Lipin1 also interacted with HIST1H2BK, which was confirmed in
SMMC7721 cells by protein immunoprecipitation. Our proteomic analysis implicated
lipin1 in novel roles in various cellular processes. © 2018 IUBMB Life,
70(8):753-762, 2018. |
Which company produces patisiran? | Patisiran has been developed by Alnylam Pharmaceuticals. | |
What protein is recruited by Crumbs to regulate tracheal development? | In Drosophila, stellate-shaped tracheal terminal cells make seamless tubes, Early endocytosis maintains normal steady-state levels of Crumbs, which recruits apical phosphorylated (active) Moesin (Moe), which in turn regulates seamless tube shape in the development of the trachea. | Many epithelial tissues undergo extensive remodelling during morphogenesis. How
their epithelial features, such as apicobasal polarity or adhesion, are
maintained and remodelled and how adhesion and polarity proteins contribute to
morphogenesis are two important questions in development. Here, we approach
these issues by investigating the role of the apical determit protein Crumbs
(Crb) during the morphogenesis of the embryonic Drosophila tracheal system. Crb
accumulates differentially throughout tracheal development and is required for
different tracheal events. The earliest requirement for Crb is for tracheal
invagination, which is preceded by an enhanced accumulation of Crb in the
invagination domain. There, Crb, acting in parallel with the epidermal growth
factor receptor (Egfr) pathway, is required for tracheal cell apical
constriction and for organising an actomyosin complex, which we propose is
mediated by Crb recruitment of moesin (Moe). The ability of a Crb isoform unable
to rescue polarity in crb mutants to otherwise rescue their invagination
phenotype, and the converse inability of a FERM-binding domain mutant Crb to
rescue faulty invagination, support our hypothesis that it is the absence of
Crb-dependent Moe enrichment, and not the polarity defect, that mainly underlies
the crb invagination phenotype. This hypothesis is supported by the phenotype of
lethal giant larvae (lgl); crb double mutants. These results unveil a link
between Crb and the organisation of the actin cytoskeleton during morphogenesis. Most tubes have seams (intercellular or autocellular junctions that seal
membranes together into a tube), but "seamless" tubes also exist. In Drosophila,
stellate-shaped tracheal terminal cells make seamless tubes, with single
branches running through each of dozens of cellular extensions. We find that
mutations in braided impair terminal cell branching and cause formation of
seamless tube cysts. We show that braided encodes Syntaxin7 and that cysts also
form in cells deficient for other genes required either for membrane scission
(shibire) or for early endosome formation (Rab5, Vps45, and Rabenosyn-5). These
data define a requirement for early endocytosis in shaping seamless tube lumens.
Importantly, apical proteins Crumbs and phospho-Moesin accumulate to aberrantly
high levels in braided terminal cells. Overexpression of either Crumbs or
phosphomimetic Moesin induced lumenal cysts and decreased terminal branching.
Conversely, the braided seamless tube cyst phenotype was suppressed by mutations
in crumbs or Moesin. Indeed, mutations in Moesin domitly suppressed seamless
tube cyst formation and restored terminal branching. We propose that early
endocytosis maintains normal steady-state levels of Crumbs, which recruits
apical phosphorylated (active) Moe, which in turn regulates seamless tube shape
through modulation of cortical actin filaments. |
Is collagen matrix of human articular cartilage changing with disease? | No,
The collagen matrix of human articular cartilage is an essentially permanent structure that has no significant turnover in adults, even with the occurrence of disease. | Type II collagen is a major component of articular cartilage and its breakdown
is a key feature of osteoarthritis. Products of cartilage collagen metabolism
can be detected in the blood, synovial fluid and urine. Several biomarker assays
have been developed which can be used to measure the synthesis and degradation
of collagen, and therefore provide information regarding cartilage turnover.
This is the first part of a two-part review and describes the need for accurate,
reliable information regarding collagen turnover, the processes by which the
biomarker epitopes are generated, their application to the study of both healthy
and diseased cartilage and the results of currently published studies, with
particular reference to the veterinary species. The second part of the review
considers the non-collagenous biomarkers of cartilage matrix turnover. |
Is ustekinumab a polyclonal antibody? | Ustekinumab is a human monoclonal IgG1 antibody targeting the p40-subunit shared by interleukin (IL)12 and IL-23. | AIM: Ustekinumab, a human monoclonal IgG1 antibody targeting the p40-subunit
shared by interleukin (IL)12 and IL-23, represents a potential treatment for
atopic dermatitis (AD). We evaluated the efficacy and safety of ustekinumab in
the treatment of AD.
METHODS: We reviewed the published literature by searching from PubMed, EMBASE,
Web of Science and ClinicalTrial.gov then retrieved and analyzed several
variables from patients records.
RESULTS: Ten studies including eight cases and two RCT, comprising 107 patients,
were included in the systematic review. Analysis all studies, a total of 58
patients (54.2%) gained an effective treatment with little adverse events.
CONCLUSIONS: Ustekinumab is a well-tolerated and safe treatment with no
significant difference in effect from placebo in patients with AD. Further,
larger randomized controlled trials need to be conducted to identify a suitable
regimen for AD and provide more evidence for clinical application. |
Where in the body, is ghrelin secreted? | Ghrelin, an orexigenic peptide, is secreted from endocrine cells in the gastric mucosa. | BACKGROUND: Ghrelin is secreted by the stomach, the hypothalamus, and the
placenta in humans and has growth hormone-secreting and orexigenic properties.
Leptin is secreted mainly by the adipocyte, plays a major role in energy
balance, and reflects fat mass in infants as well as adults. Leptin and ghrelin
central effects are mediated, at least partly, through the neuropeptide Y/Y1
receptor pathway in the hypothalamus.
METHODS: We determined whether ghrelin is also present in the fetus and
investigated its relationship to leptin, growth hormone, birth weight, and calf
and abdominal circumferences in 90 full-term neonates.
RESULTS: Immunoreactive ghrelin was detected in all cord samples (mean +/- SD,
187 +/- 88 pmol/L; range, 66-594 pmol/L). In contrast to leptin, ghrelin
concentrations of boys and girls were not statistically different. In female
neonates, ghrelin is inversely correlated with anthropometric measures. In male
neonates, ghrelin is positively correlated with leptin and negatively with
growth hormone.
CONCLUSION: The presence of significant ghrelin concentrations in all neonates
before the first feeding is intriguing. Unlike the fairly constant
concentrations and effects of leptin over the short term, the wide variability
of ghrelin concentrations observed in newborns raises the possibility that
ghrelin secretion causes short-term changes in feeding behavior. We suggest that
ghrelin may play a physiologic role in the initiation of feeding. Ghrelin is a recently described hormone secreted by the stomach. Ghrelin
administration in ad-libitum-fed rodents was shown to increase appetite as well
as body weight and body fat content, showing metabolic effects of ghrelin in
vivo and suggesting its involvement in the pathogenesis of obesity. However,
plasma ghrelin concentration was shown to be inversely correlated with body
weight and body fat in people and rodents. Increased plasma ghrelin
concentration was also reported during diet-induced weight loss and in
malnourished states. These findings suggest that circulating ghrelin is
regulated by nutritional state and body fat with a feedback mechanism opposing
changes in body composition, with a potential key adaptive role during calorie
restriction. Plasma ghrelin concentration was shown to be increased in advanced
renal failure and hemodialysis patients. The known metabolic effects of ghrelin
and the potential implications of hyperghrelinemia in kidney disease will be
discussed in this article. OBJECTIVES: Ghrelin, a recently discovered hormone mainly secreted by the
stomach, has several metabolic functions including regulation of food intake,
energy homeostasis and body weight. There are few studies on this hormone in
healthy infants during the first year of life. The aim of this study was to
examine the correlations between ghrelin and weight gain in healthy term infants
in the first year of life.
METHODS: 104 healthy term infants aged 0 to 12 months were included in a
cross-sectional study. Anthropometric measurements were assessed and mean weight
gain was calculated. Serum ghrelin concentrations have been determined at least
3 hours after feeding by radioimmunoassay test.
RESULTS: Ghrelin concentrations were correlated negatively to weight gain
(r=-0.302; P=0.003) and positively to age (r = 0.412; P < 0.001), weight (r =
0.374; P < 0.001) and length (r=0.387; P<0.001). In breastfed infants a
statistically significant negative correlation between ghrelin concentration and
infant weight gain (r=-0.407; P=0.001) was observed, whereas in formula-fed
infants this correlation was not statistically significant (r=-0.067; P=0.719).
CONCLUSIONS: The negative correlation observed between ghrelin concentration and
infant weight gain suggests that ghrelin might also play a role in the
regulation of body weight in healthy infants with a physiologic energy balance.
Further studies are needed to clarify how ghrelin might be involved in both
short-term and long-term energy balance. BACKGROUND: Ghrelin is a body weight-regulating peptide produced and secreted
primarily by the gastric mucosa. Helicobacter pylori infection impairs gastric
ghrelin production, leading to a lower plasma ghrelin concentration. However,
the effect of H. pylori eradication on plasma ghrelin levels and its relation to
body weight change after H. pylori cure are still uncertain. We examined the
association of plasma ghrelin levels with gastric ghrelin production and body
weight change before and after H. pylori eradication.
METHODS: Plasma ghrelin concentrations, gastric ghrelin expression, and body
weight were determined in a total of 134 consecutive individuals before and 12
weeks after successful H. pylori eradication. Gastric ghrelin expression was
evaluated by determining mRNA expression levels and the number of
ghrelin-producing cells in gastric mucosa biopsy specimens by real-time reverse
transcriptase-polymerase chain reaction and immunohistochemistry, respectively.
RESULTS: Plasma ghrelin concentration increased in 50 patients and decreased in
84 patients after H. pylori eradication. After H. pylori cure, however, gastric
preproghrelin mRNA expression was increased nearly fourfold (P < 0.0001), and
the number of ghrelin-positive cells was increased or unchanged. In contrast,
plasma ghrelin changes after H. pylori cure were inversely correlated with both
body weight change (P < 0.0001) and initial plasma ghrelin levels (P < 0.0001).
CONCLUSIONS: Changes in plasma ghrelin concentrations before and after H. pylori
cure were inversely correlated with body weight change and initial plasma
ghrelin levels but not with gastric ghrelin production in Japanese patients. BACKGROUND & AIMS: Ghrelin is secreted by the stomach and stimulates food
intake. Obese individuals have lower fasting plasma ghrelin levels but increased
appetite, suggesting greater responses to endogenous ghrelin in obesity. The aim
of this study was to compare effects of exogenous ghrelin (at a dose that
stimulates growth hormone [GH] release in the physiologic range) versus placebo
on gastric emptying, gastric volume, and postprandial symptoms and determine
whether body mass (ranging from normal weight to obesity) influences responses
to ghrelin.
METHODS: After intravenous bolus synthetic human ghrelin (0.33 mug/kg) or
saline, we measured plasma GH, gastric volume, and gastric emptying by combined
(99m)Tc-single-photon emission computed tomography and scintigraphy ((111)In egg
meal, 300 kcal) and postprandial symptoms using visual analogue scales.
RESULTS: In 25 obese subjects (5 men and 20 women; body mass index [BMI], 36 +/-
4 kg/m(2)) and 13 female normal-weight (BMI, 22 +/- 2 kg/m(2)) subjects of
similar ages, ghrelin increased GH levels (15.0 +/- 2.4 ng/mL) at 40 minutes
postinjection and tended to decrease fasting gastric volumes compared with
placebo (P = .059). There were no effects of BMI on treatment response and no
differences between ghrelin and saline on postprandial (P = .09) or change in
(postprandial minus fasting) gastric volumes, gastric emptying, or aggregate
postprandial symptoms. Effects of ghrelin did not differ between obese and
normal-weight participants.
CONCLUSIONS: At doses that stimulate physiologic GH plasma levels, synthetic
ghrelin tended to decrease fasting gastric volumes without altering postprandial
volumes or gastric emptying in a predomitly female cohort. The data are not
consistent with the hypothesis that higher body mass is associated with
increased gastric responsiveness to ghrelin. Ghrelin, the only known orexigenic gut hormone, is secreted mainly from the
stomach, increases with fasting and before meal initiation in humans and rats,
and increases food intake after central or peripheral administration. To
investigate sex differences in the action of ghrelin, we assessed the effects of
exogenous ghrelin in intact male and female rats, the effects of exogenous
ghrelin in ovariectomized (OVX) and estradiol (E2)-treated female rats, as well
as the effects of OVX on plasma ghrelin and hypothalamic orexigneic neuropeptide
expression in rats and on food intake and weight gain in transgenic mice lacking
the ghrelin receptor (Ghsr(-/-) mice). Male and OVX female rats were
significantly more sensitive than intact female rats to the orexigenic effects
of both centrally (intra-third ventricular, i3vt, 0.01, 0.1, and 1.0 nmol) and
systemically (ip, 3, 6, and 9 nmol) administered ghrelin. This difference is
likely to be estradiol dependent because E2 attenuated the orexigenic action of
ghrelin in OVX female and male rats. Furthermore, OVX increased food intake and
body weight in wild-type mice, but not in Ghsr(-/-) mice, suggesting that OVX
increases food intake by releasing ghrelin from a tonic inhibitory effect of
estradiol. In addition, following OVX, there was an increase in plasma ghrelin
that was temporally associated with increased food intake, body weight, and
hypothalamic neuropeptide Y and Agouti-related protein mRNA expression.
Collectively, these data suggest that estradiol inhibits the orexigenic action
of ghrelin in females, that weight gain associated with OVX is ghrelin mediated,
and that this endocrine interaction may account for an important sex differences
in food intake and the regulation of body weight. OBJECTIVE: Ghrelin is a hormone secreted mainly in the stomach which stimulates
appetite and food intake. Endocrine factors are among the causes of anorexia in
elderly people. The main objective of the present study was to examine the
effect of age on ghrelin levels in non-institutionalized elderly people.
DESIGN AND SETTING: Observational, cross-sectional, population-based study.
PARTICIPANTS: A random sample of men aged 70 yr or older was taken from the
municipal census.
MEASUREMENTS: All participants underwent a physical examination which measured
weight and height, grip strength, functional capacity (according to the Barthel
Index) and nutritional status (according to the short form of the Mini
Nutritional Assessment). Blood was taken for basic biochemical analysis,
determination of somatotropic, corticotropic, and gonadotropic hormones, and for
measurement of ghrelin and cholecystokinin.
RESULTS: 152 men with a mean (SD) age of 76.7 (5.4) yr were recruited. Mean
ghrelin levels were 1143 (401) pg/ml. A weak negative correlation was found
between ghrelin levels and age (r=-0.16, p=0.057). Multiple linear regression
analysis showed a significant and independent effect of age (beta=-12.1,
p=0.049), body mass index (BMI) (beta=-22.0, p=0.021), and creatinine levels
(beta=407.7, p=0.002) on ghrelin. No correlations with age and BMI were found
for cholecystokinin.
CONCLUSIONS: There is a slight decrease in ghrelin levels with age in older men
aged 70 yr or more, although the clinical relevance of this finding remains
unclear. Ghrelin is produced primarily in the stomach in response to hunger, and
circulates in the blood. Plasma ghrelin levels increase during fasting and
decrease after ingesting glucose and lipid, but not protein. The efferent vagus
nerve contributes to the fasting-induced increase in ghrelin secretion. Ghrelin
secreted by the stomach stimulates the afferent vagus nerve and promotes food
intake. Ghrelin also stimulates pituitary gland secretion of growth hormone (GH)
via the afferent vagus nerve. GH inhibits stomach ghrelin secretion. These
findings indicate that the vagal circuit between the central nervous system and
stomach has a crucial role in regulating plasma ghrelin levels. Moreover, body
mass index modulates plasma ghrelin levels. In a lean state and anorexia
nervosa, plasma ghrelin levels are increased, whereas in obesity, except in
Prader-Willi syndrome, plasma ghrelin levels are decreased and the feeding- and
sleeping-induced decline in plasma ghrelin levels is disrupted. There are two
forms of ghrelin: active n-octanoyl-modified ghrelin and des-acyl ghrelin.
Fasting increases both ghrelin types compared with the fed state. Hyperphagia
and obesity are likely to decrease plasma des-acyl ghrelin, but not
n-octanoyl-modified ghrelin levels. Hypothalamic serum and
glucocorticoid-inducible kinase-1 and serotonin 5-HT2C/1B receptor gene
expression levels are likely to be proportional to plasma des-acyl ghrelin
levels during fasting, whereas they are likely to be inversely proportional to
plasma des-acyl ghrelin levels in an increased energy storage state such as
obesity. Thus, a dysfunction of the ghrelin feedback systems might contribute to
the pathophysiology of obesity and eating disorders. Identification of ghrelin started with the discovery of growth hormone
secretagogues, continued with the description of ghrelin receptors and ended
with the elucidation of the chemical structure of ghrelin. However, several
issues concerning the role of ghrelin in physiological and pathophysiological
processes are still under investigation. Most of the ghrelin produced in the
body is secreted in the stomach, but it is also expressed in the hypothalamus,
pituitary, pancreas, intestine, kidney, heart and gonads. Ghrelin stimulates
growth hormone secretion via growth hormone secretagogue receptors. Ghrelin
secretion in the stomach depends on both acute and chronic changes in
nutritional status and energy balance. Current data support the hypothesis that
the stomach, in addition to its important role in digestion, not only influences
pituitary hormone secretion but, via ghrelin production, it also sends
orexigenic (appetite increasing) signals to hypothalamic nuclei involved in the
regulation of energy homeostasis. In addition to these main effects, ghrelin
influences insulin secretion and glucose metabolism and it may exert potentially
important effects on cardiovascular and gastrointestinal functions. Because of
its effects on a large number of physiological functions, ghrelin may be
involved in the pathomechanism of several human disorders, including
disturbances of appetite, energy homeostasis and glucose metabolism. Further
research might lead to a better understanding of the pathophysiology of ghrelin
and might provide more effective therapy for the above disorders. Ghrelin is primarily secreted from the stomach and has been implicated in the
coordination of eating behavior and weight regulation. Ghrelin also plays an
essential role in the mechanism of gastric mucosal defense. Thus, it is
important to clarify which diseases primarily influence changes in plasma
ghrelin concentrations. Helicobacter pylori (H pylori) infection is involved in
the pathogenesis of gastritis, gastric and duodenal ulcer, gastric carcinoma,
and mucosa-associated lymphoid tissue lymphoma. H pylori eradication is related
to body weight change. Compared, H pylori infected and negative subjects with
normal body mass index, plasma ghrelin concentration, gastric ghrelin mRNA, and
the number of ghrelin producing cells in gastric mucosa are significantly lower
in H pylori infected subjects than in H pylori-negative controls. Plasma ghrelin
concentration decreases with the progression of gastric atrophy. Impaired
gastric ghrelin production in association with atrophic gastritis induced by H
pylori infection accounts for the decrease in plasma ghrelin concentration.
However, the ratio of plasma acylated ghrelin to total ghrelin levels is higher
in patients with chronic atrophic gastritis than in healthy subjects. This may
result from the compensatory increase in plasma active ghrelin concentration in
response to gastric atrophy. After H pylori eradication, gastric preproghrelin
mRNA expression is increased nearly 4-fold in most cases. However, changes in
plasma ghrelin concentrations before and after H pylori cure are not associated
with the gastric ghrelin production. Plasma ghrelin changes are inversely
correlated with both body weight change and initial plasma ghrelin levels. Ghrelin is a peptide hormone produced and secreted in the stomach. Numerous
studies over the past decade demonstrate its importance in food intake,
body-weight regulation and glucose homeostasis. These effects are driven largely
by the high expression of the ghrelin receptor (GHSR1a) in the hypothalamus.
However, GHSR1a is also expressed in numerous extra-hypothalamic neuronal
populations, suggesting that ghrelin has physiological functions besides those
involved in metabolic functions. In this review, I focus on increasing evidence
that ghrelin has important roles in extra-hypothalamic functions, including
learning and memory, reward and motivation, anxiety and depression, and
neuroprotection. Furthermore, I discuss how the recently demonstrated role of
ghrelin in promoting survival during periods of caloric restriction could
contribute to its inherent neuroprotective and neuromodulatory properties. BACKGROUND: Ghrelin is secreted mainly in the stomach and plays a role in food
intake regulation. Morbidly obese (MO) individuals report a decline in appetite
after sleeve gastrectomy (SG), presumably due, in part, to ghrelin cell removal.
Ghrelin cell distribution and expression were determined in three areas of
resected stomach specimens from MO patients subjected to SG.
METHODS: Resected stomach specimens from 20 MO patients undergoing SG were
analyzed. Real-time polymerase chain reaction of ghrelin mRNA and
immunohistostaining for ghrelin cells in three stomach regions (fundus, body,
and pre-antral areas) were performed. Body mass index (BMI) and total plasma
ghrelin levels were obtained before and 3 months postoperatively.
RESULTS: Ghrelin mRNA was detected throughout the stomach, its expression
decreasing from the fundus towards the antrum. The relative quantification for
ghrelin mRNA expression was 0.043, 0.026, and 0.015 at the fundus, body, and
pre-antral region, respectively (P = 0.05, fundus vs. pre-antral region).
Average ghrelin cell counts declined from 60 ± 40 to 45 ± 20 and 39 ± 13
cells/high power fields in the fundus, body, and pre-antral region,
respectively. Three months after surgery, total plasma ghrelin levels decreased
from 1,676 ± 470 to 1,179 ± 188 pg/ml (P < 0.00001) and BMI dropped from 46 ± 6
to 38 ± 5 kg/m2 (P < 0.00001).
CONCLUSIONS: Distribution and expression of ghrelin-secreting cells throughout
the stomach were defined, emphasizing the importance of meticulous resection of
the fundus during SG for maximal ghrelin cell removal. BACKGROUND: A wide variety of functions has been attributed to ghrelin, a
peptide hormone secreted in the stomach. The objective of the study was to
assess the association of ghrelin concentrations with body composition among
Iranian children.
METHODS: In this study, blood samples of 57 boys and 54 girls aged 6-10 were
collected to measure ghrelin levels. Fat mass (FM) and fat-free mass (FFM) were
examined by body composition analyzer. Actigraph GT3X was administered to assess
children's physical activity and sleep. Data were analyzed using linear
regression models.
RESULTS: All measured parameters did not differ between genders except for sleep
time which was higher and sleep efficacy which was lower in boys compared with
girls. None of the FM and FFM indices studied in boys was significantly
associated with ghrelin levels. In girls, however, ghrelin concentrations were
significantly associated with FM (β = 0.04, P = 0.01), fat mass index (β = 0.07,
P = 0.008), and fat-free mass index (β = 0.08, P = 0.04) and near-significantly
associated with FFM (β = 0.03, P = 0.09) after adjusting for age, physical
activity, sleep, and dietary intake.
CONCLUSION: Girls with higher ghrelin levels were more likely to have increased
total FM and FFM. Conversely, body composition was not associated with ghrelin
levels in boys. Consequently, ghrelin may influence the gender-related
differences of body composition during childhood in girls. But, further study is
needed to confirm our findings. PURPOSE: Ghrelin is mainly secreted from the stomach and plays a role in
appetite, weight gain, and the promotion of a positive energy balance. The
levels of ghrelin decrease immediately after gastrectomy. We herein investigated
the effect of the administration of synthetic ghrelin to treat postoperative
severe weight loss in a prospective, one-arm clinical trial to develop new
strategies for weight gain.
METHODS: Ten patients (four distal gastrectomy and six total gastrectomy)
received ghrelin treatment. Eligibility criteria included patients who underwent
gastrectomy more than 1 year previously and 15 % body weight loss from the
preoperative weight or a body mass index under 19. Synthetic human ghrelin
(3 μg/kg) was administered to the patients twice a day for 1 week. Oral intake
of calories, appetite [evaluated using the visual analog scale (VAS)], and body
weight before and during administration of ghrelin were compared.
RESULTS: There was a significant difference in the oral food intake before and
during treatment (before treatment: 1236 ± 409 kcal vs. during treatment:
1398 ± 365 kcal, p = 0.039), and the VAS for appetite significantly improved
with each day of ghrelin administration (p < 0.05). Significant amounts of body
weight were gained (39.5 ± 6.8 vs. 40.1 ± 6.9, p = 0.037).
CONCLUSIONS: The administration of synthetic ghrelin improved the food intake
and was effective for treating appetite loss and body weight loss. Synthetic
ghrelin may be a promising new therapy for severe body weight loss following
gastrectomy. BACKGROUND: Ghrelin, an orexigenic peptide, is secreted from endocrine cells in
the gastric mucosa. Circulating levels rise in the preprandial phase, suggesting
an anticipatory or cephalic phase of release, and decline in the postprandial
phase, suggesting either the loss of a stimulatory factor or inhibition by
factors released when nutrients enter the intestine. We hypothesized that vagal
signals are not required for the (i) preprandial increase or (ii) postprandial
suppression of ghrelin levels. Further, we wanted to investigate the hypothesis
that (iii) glucagon-like peptide-1 might be implicated in the postprandial
decline in ghrelin levels.
METHODS: We measured ghrelin levels in plasma from sham-feeding and meal studies
carried out in vagotomized individuals and controls, and from a GLP-1 infusion
study carried out in fasting healthy young individuals.
KEY RESULTS: We find that (i) ghrelin secretion is unchanged during indirect
vagal stimulation as elicited by modified sham-feeding in vagotomized
individuals and matched controls, (ii) ghrelin secretion is similarly suppressed
after meal ingestion in vagotomized individuals and controls, and (iii) infusion
of GLP-1 does not lower ghrelin levels.
CONCLUSIONS & INFERENCES: We conclude that for postprandial suppression of
circulating ghrelin levels, a circulating factor (but not GLP-1) or short
(duodeno-gastric) reflexes seem to be implicated. |
List the ERM proteins. | ezrin
radixin
moesin | This review deals with recent advances in studies on P-glycoprotein (P-gp) and
its expression regulators, focusing especially on our own research. Firstly, we
describe findings demonstrating that the distribution of P-gp along the small
intestine is heterogeneous, which explains why orally administered P-gp
substrate drugs often show bimodal changes of plasma concentration. Secondly, we
discuss the post-translational regulation of P-gp localization and function by
the scaffold proteins ezrin, radixin and moesin (ERM proteins), together with
recent reports indicating that tissue-specific differences in regulation by ERM
proteins in normal tissues might be retained in corresponding cancerous tissues.
Thirdly, we review evidence that P-gp activity is enhanced in the process of
epithelial-to-mesenchymal transition (EMT), which is associated with cancer
progression, without any increase in expression of P-gp mRNA. Finally, we
describe two examples in which P-gp critically influences the brain distribution
of drugs, i.e., oseltamivir, where low levels of P-gp associated with early
development allow oseltamivir to enter the brain, potentially resulting in
neuropsychiatric side effects in children, and cilnidipine, where impairment of
P-gp function in ischemia allows cilnidipine to enter the ischemic brain, where
it exerts a neuroprotective action. Leukocyte transendothelial migration (TEM) is absolutely fundamental to the
inflammatory response, and involves initial pseudopod protrusion and subsequent
polarised migration across inflamed endothelium. Ezrin/radixin/moesin (ERM)
proteins are expressed in leukocytes and mediate cell shape changes and
polarity. The spatio-temporal organisation of ERM proteins with their targets,
and their individual contribution to protrusion during TEM, has never been
explored. Here, we show that blocking binding of moesin to phosphatidylinositol
4,5-bisphosphate (PIP2) reduces its C-terminal phosphorylation during monocyte
TEM, and that on-off cycling of ERM activity is essential for pseudopod
protrusion into the subendothelial space. Reactivation of ERM proteins within
transmigrated pseudopods re-establishes their binding to targets, such as
L-selectin. Knockdown of ezrin, but not moesin, severely impaired the
recruitment of monocytes to activated endothelial monolayers under flow,
suggesting that this protein plays a unique role in the early recruitment
process. Ezrin binds preferentially to L-selectin in resting cells and during
early TEM. The moesin-L-selectin interaction increases within transmigrated
pseudopods as TEM proceeds, facilitating localised L-selectin ectodomain
shedding. In contrast, a non-cleavable L-selectin mutant binds selectively to
ezrin, driving multi-pseudopodial extensions. Taken together, these results show
that ezrin and moesin play mutually exclusive roles in modulating L-selectin
signalling and shedding to control protrusion dynamics and polarity during
monocyte TEM. |
What is epitranscriptomics? | Epitranscriptomics is the fast expanding area of RNA modifications. | Author information:
(1)a Medical University of Vienna , Department of Cell- and Developmental
Biology , Vienna , Austria.
(2)b UNIVERSITA DEGLI STUDI DI TRENTO , Italy.
(3)c CEITEC, Masaryk University , Brno , Czech Republic.
(4)d Johannes Gutenberg Universitat Mainz , Mainz , Germany.
(5)e University of Cambridge , Cambridge , United Kingdom.
(6)f Hospital Complex of Malaga (Virgen de la Victoria) , Malaga , Spain.
(7)g Stockholm University , Sweden.
(8)h IMBA - Institute of Molecular Biotechnology , Vienna , Austria.
(9)i Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied
Genoproteomics (GIGA), University of Liege , Sart Tilman , Belgium.
(10)j ULB-Faculty of Medicine , Brussels , Belgium.
(11)k The Cyprus Institute of Neurology & Genetics (CING) , Cyprus.
(12)l University of Copenhagen , Copenhagen , Denmark.
(13)m CNRS, University of Perpig , Perpig , France.
(14)n Lorraine University -CNRS Biopole UL , Lorraine , France.
(15)o Institute of Molecular Biology , Mainz , Germany.
(16)p University of Thessaly , Department of Biochemistry and Biotechnology
Thessaly , Greece.
(17)q Biotalentum Ltd Gödöllö , Hungary.
(18)r University College Cork Biochemistry Department , Cork , Ireland.
(19)s Trinity College Dublin Trinity Biomedical Sciences Institute , Dublin ,
Ireland.
(20)t Technion - Israel institute of technology , Haifa , Israel.
(21)u Tel Aviv University , Tel Aviv , Israel.
(22)v Center for Genomic Science of IIT@SEMM , Milano , Italy.
(23)w University of Latvia , Riga , Latvia.
(24)x Riga Stradins University A.Kirhensteins Institute of Microbiology , Riga ,
Latvia.
(25)y National Blood Transfusion Service, St. Luke's Hospital , Malta.
(26)z University of Malta Centre for Molecular Medicine and Biobanking
Biomedical sciences , Malta.
(27)aa Norwegian University of Science and Technology Department of Cancer
Research and Molecular Medicine, Faculty of Medicine Norwegian , Trondheim ,
Norway.
(28)ab Oslo University Hospital , Oslo , Norway.
(29)ac International Institute of Molecular and Cell Biology in Warsaw , Poland.
(30)ad Instituto Portugues de Oncologia do Porto , Porto , Portugal.
(31)ae IPATIMUP , Porto , Portugal.
(32)af "Victor Babes" National Institute of Pathology Bucharest , Romania.
(33)ag Faculty of Biology , University o Bucharest , Bucharest , Romania.
(34)ah Institute for Biological Research "Sinisa Stankovic" , Belgrade , Serbia.
(35)ai Institute of Molecular Genetics and Genetic Engineering, University of
Belgrade , Belgrade , Serbia.
(36)aj Faculty of Pharmacy, University of Bratislava , Slovakia.
(37)ak Fundacion para la Gestion de la Investigacion Biomedica de Cadiz , Cadiz
, Spain.
(38)al Polygene AG , Zürich , Switzerland.
(39)am Gebze Technical University , Gebze , Turkey.
(40)an Istanbul Medipol University , Istanbul , Turkey.
(41)ao University of Dundee Centre for Gene Regulation and Expression School of
Life Sciences , Dundee , United Kingdom.
(42)ap Universite Libre de Bruxelles , Gosselies , Belgium.
(43)aq Institut de Genomique Fonctionnelle , Montpellier , France.
(44)ar Institut de Biologie Paris Seine - Pierre et Marie Curie University
Institut de Biologie Paris , Paris , France.
(45)as German Cancer Research Center , Heidelberg , Germany.
(46)at University of Kassel , Kassel , Germany.
(47)au Weizmann Institute of Science , Rehovot , Israel.
(48)av Institute for Advanced Bioscience , Grenoble , France.
(49)aw Fundacion IMDEA Alimentacion Ctra . de Canto Blanco, Madrid , Spain.
(50)ax Germans Trias i Pujol Research Institute , Barcelona , Spain.
(51)ay University of Edinburgh MRC Centre for Regenerative Medicine , Edinburgh
, United Kingdom.
(52)az The Francis Crick Institute , London , United Kingdom.
(53)ba University of Nottingham School of Biosceinces , Nottingham , United
Kingdom. |
What is resistin? | The adipocyte-secreting adipokine, resistin, may play a critical role in the modulation of inflammatory diseases. | Resistin is a recently discovered hormone that is exclusively expressed in
adipose tissue. Its expression in rodents was reported to be elevated or
suppressed in genetic and diet-induced obesity, respectively. Resistin treatment
impaired glucose tolerance and insulin action. Immunoneutralization of resistin
improved insulin sensitivity, while thiazolidinedione treatment reduced resistin
expression. Therefore, resistin could play a critical role in the development of
obesity and type 2 diabetes. In this study were determined resistin plasma
levels in humans suffering from type 1 and type 2 diabetes and in healthy
controls. Plasma levels of resistin in healthy controls were 38.78 ng/ml. They
were not statistically different in individuals with a broad BMI range. Resistin
plasma levels in type 2 diabetes were 38.7 ng/ml, and 39.4 ng/ml in type 1
diabetes. Thiazolidinedione treatment did not influence resistin plasma levels.
We conclude from our data: 1. resistin can be detected in human plasma, 2.
plasma resistin levels are not different in type 1 and type 2 diabetes. Resistin is an adipose-derived hormone that has been proposed as a link among
obesity, insulin resistance, and diabetes. In agreement with a role of resistin
in insulin resistance, the administration of recombit resistin led to glucose
intolerance in mice and impaired insulin action in rat liver. However, the
regulation of resistin expression by physiological conditions, hormones, or
agents known to modulate insulin sensitivity does not always support the
association between resistin and obesity-induced insulin resistance. In the
present study we investigated the effects of leptin administration on adipose
resistin expression in insulin-resistant and obese ob/ob mice. We show that the
expression of resistin mRNA and protein in adipose tissue is lower in ob/ob than
in wild-type control mice, in agreement with the reduced adipocyte resistin mRNA
level reported in several models of obesity. Leptin administration in ob/ob mice
resulted in improvement of insulin sensitivity concomitant with a decrease in
resistin gene expression. The lack of effect of leptin on resistin in db/db mice
indicated that the leptin inhibitory action on resistin expression requires the
long leptin receptor isoform. In addition, we demonstrated that the effect of
leptin on resistin expression was centrally mediated. High-fat feeding in
C57BL/6J wild-type mice, which is known to induce the development of obesity and
insulin resistance, produced an increase in resistin expression. Interestingly,
in both ob/ob and high fat-fed mice we obtained a striking positive correlation
between glycemia and resistin gene expression. In conclusion, our results
demonstrate that leptin decreases resistin expression and suggest that resistin
may influence glucose homeostasis. Resistin is a new adipocytokine which is expressed in rat, mouse and possibly
human adipose tissue. Its putative role as a mediator of insulin resistance is
controversial. We hypothesized that resistin, like leptin, would have multiple
roles in non-adipose tissues and we reported that resistin is expressed in mouse
brain and pituitary. Moreover, resistin expression in female mouse pituitary is
developmentally regulated and maximal expression occurs peripubertally. Although
the role of endogenous resistin in mouse brain and pituitary has not been
determined, our data suggest that resistin could be important in the postnatal
maturation of the hypothalamic-pituitary system. In the present study we
compared the ontogeny of resistin gene expression in the pituitary of male and
female mice using semi-quantitative RT-PCR analysis. We show that resistin
expression is developmentally regulated in the pituitary of male and female CD1
mice. However, significant gender differences were evident (male > female at
postnatal day 28 and 42) and this was not modified by neonatal treatment of
female pups with testosterone. Since resistin expression in adipose tissue is
also influenced by obesity, we evaluated resistin expression in fat, brain and
pituitary of the obese ob/ob mouse. Resistin mRNA was significantly increased in
both visceral and subcutaneous adipose depots in postnatal day 28 ob/ob mice
compared to controls, but pituitary resistin expression was significantly
reduced. In contrast to the prepubertal levels, and in agreement with other
reports, adipose resistin expression was reduced in adult ob/ob mice. In a third
set of experiments we examined the influence of food deprivation on pituitary
and fat resistin mRNA. Resistin gene expression was severely down-regulated by a
24-hour fast in adipose and pituitary tissue but not in hypothalamus. In
conclusion, pituitary resistin expression is age- and gender-dependent. In ob/ob
mice, and in fasted mice, resistin is regulated in a tissue-specific manner.
Thus in visceral fat obesity increases but starvation decreases resistin mRNA.
In contrast, pituitary levels are decreased in the presence of both high (ob/ob)
and low (fasting) adipose stores. Further studies are required to define the
unexpected hormonal regulation of resistin gene expression in the pituitary. Resistin is known as an adipocyte-specific secretory hormone that can cause
insulin resistance and decrease adipocyte differentiation. It can be regulated
by sexual hormones. Whether environmental estrogens regulate the production of
resistin is still not clear. Using 3T3-L1 adipocytes, we found that octylphenol
upregulated resistin mRNA expression in dose- and time-dependent manners. The
concentration of octylphenol that increased resistin mRNA levels by 50% was
approximately 100 nM within 6 h of treatment. The basal half-life of resistin
mRNA induced by actinomycin D was lengthened by octylphenol treatment,
suggesting that octylphenol decreases the rate of resistin mRNA degradation. In
addition, octylphenol stimulated resistin protein expression and release. The
basal half-life of resistin protein induced by cycloheximide was lengthened by
octylphenol treatment, suggesting that octylphenol decreases the rate of
resistin protein degradation. While octylphenol was shown to increase activities
of the estrogen receptor (ER) and MEK1, signaling was demonstrated to be blocked
by pretreatment with either ICI-182780 (an ERalpha antagonist) or U-0126 (a MEK1
inhibitor), in which both inhibitors prevented octylphenol-stimulated
phosphorylation of ERK. These results imply that ERalpha and ERK are necessary
for the octylphenol stimulation of resistin mRNA expression. Moreover, U-0126
antagonized the octylphenol-increased resistin protein expression and release.
These data suggest that the way octylphenol signaling increases resistin protein
levels is similar to that by which it increases resistin mRNA levels; it is
likely mediated through an ERK-dependent pathway. In vivo, octylphenol increased
adipose resistin mRNA expression and serum resistin and glucose levels,
supporting its in vitro effect. The body mass index, and especially the lean/fat tissue ratio, are determits
of female fertility. In 1996, it was claimed that leptin might be the "missing
link" between fat and reproduction. Leptin belongs to the adipokine family,
which also contains adiponectin and resistin. Leptin and resistin impair insulin
sensitivity, whereas adiponectin enhances it. Leptin is a potent stimulator of
central GnRH and gonadotropin secretion, and, paradoxically, a potent inhibitor
of ovarian steroidogenesis. The central roles of adiponectin and resistin are
less clear. In the ovary, adiponectin stimulates steroidogenesis by granulosa
cells. Recent data point to the existence of a distinct lipid metabolism in the
ovary. Its role in female reproduction will provide an exciting field of
research in coming years. OBJECTIVE: Resistin is a secreted factor that is elevated in rheumatoid
arthritis (RA) and believed to drive joint inflammation in vivo. This study was
undertaken to determine if resistin is present in the joint following joint
injury and to elucidate the role of resistin in cartilage degradation.
METHODS: The level of resistin was measured in paired synovial fluid (SF) and
serum samples from patients following joint injury (anterior cruciate ligament,
ACL or meniscus tear). Localization of resistin was visualized by
immunohistochemistry of synovial tissue and cartilage from healthy and OA
donors. Mouse and human cartilage cultures were used to assess the effect of
resistin on cartilage metabolism.
RESULTS: In trauma patients, resistin levels declined with increasing time post
injury. The resistin levels were highest in samples collected up to 1 week
following traumatic injury (SF: 2980 pg/ml, serum: 7901 pg/ml) and lowest in
samples collected 6-26 years post injury (SF: 686 pg/ml, serum: 5682 pg/ml).
Resistin was shown to be expressed in macrophage-like cells in both healthy and
OA synovial tissue. Treatment of mouse cartilage cultures with recombit
resistin led to a dose dependent loss of proteoglycan and induction of
inflammatory cytokine and PGE(2) production. Recombit resistin inhibited
proteoglycan synthesis in human cartilage explants.
CONCLUSION: Resistin is elevated both systemically and locally in the weeks
immediately following joint injury and has a direct effect on cartilage matrix
turnover and cytokine production. Resistin may play a role in the early stages
of trauma-induced OA and may represent a new therapeutic target to slow joint
destruction in OA. OBJECTIVES: Resistin is an adipocytokine that has been related to inflammation
and insulin resistance. Following knee injury, elevated levels of resistin have
been found in synovial fluid (SF) while very little is known about the role of
resistin in osteoarthritis (OA). The aim of the present study was to investigate
resistin levels in OA joints and to determine if it is associated with
inflammatory and catabolic factors in the joints.
METHOD: SF, plasma, and cartilage samples were collected from 88 OA patients
undergoing knee replacement surgery. Resistin levels were measured by
enzyme-linked immunosorbent assay (ELISA) in SF, plasma, and cartilage culture
media.
RESULTS: Significant levels of resistin [0.75 (0.67) ng/mL; median (IQR)] were
found in SF from OA patients. Resistin correlated positively with interleukin
(IL)-6 (r = 0.39, p < 0.001) and with matrix metalloproteinases MMP-1 (r = 0.31,
p = 0.004) and MMP-3 (r = 0.24, p = 0.024) in SF. Resistin was also released
from cultured OA cartilage and it correlated with resistin levels in SF (r =
0.39, p < 0.001). In addition, resistin levels in plasma correlated positively
with those in SF (r = 0.44, p < 0.001). There were no differences in SF or
plasma resistin concentrations between females and males or between non-diabetic
and diabetic patients, and resistin did not correlate with body mass index
(BMI).
CONCLUSIONS: Resistin is present in OA joints and is released from OA cartilage.
Levels of resistin in SF are associated with inflammatory and catabolic factors,
suggesting that resistin has a role to play in the pathogenesis of, and as a
possible drug target in, OA. BACKGROUND: Adipokines, such as resistin and adiponectin, modify inflammation
and may contribute to increased asthma risk and severity in obese people.
OBJECTIVE: To examine plasma resistin and resistin:adiponectin ratio (i) in
asthmatics compared to healthy controls, (ii) according to asthma severity,
obesity and gender (iii) following weight loss in obese asthmatics.
METHODS: In a cross-sectional observational study of asthmatic adults (n = 96)
and healthy controls (n = 46), plasma resistin and adiponectin were measured. In
a separate intervention study, obese asthmatic adults (n = 27) completed a
10-week weight loss intervention and plasma resistin and adiponectin
concentrations were analysed.
RESULTS: Plasma resistin and resistin:adiponectin ratio were higher in asthma
compared to controls and were higher again in subjects with a severe vs.
mild-to-moderate asthma pattern. Amongst asthmatic subjects, resistin was not
modified by gender or obesity, while adiponectin was lower in males and obese
subjects. As a result, resistin:adiponectin ratio was higher in obese males,
non-obese males and obese females, compared to non-obese females. In a logistic
regression model, plasma resistin concentration was a predictor of asthma risk.
In a multiple linear regression model, plasma resistin:adiponectin ratio was a
negative predictor of FEV1 in asthma. Following weight loss, neither resistin,
adiponectin nor resistin:adiponectin ratio was changed. However, the change (∆)
in %body fat was associated with ∆ resistin:adiponectin ratio. Post-intervention
∆ resistin was negatively correlated with both ∆FRC and ∆RV.
CONCLUSION AND CLINICAL RELEVANCE: This study demonstrates that resistin and
resistin:adiponectin ratio are higher in asthma and are higher again in subjects
who have more severe disease. Resistin:adiponectin ratio is highest in obese
male asthmatics. As resistin is a predictor of asthma risk and
resistin:adiponectin is a predictor of FEV1 in asthma, these adipokines may be
contributing to the obese asthma phenotype, thus providing a potential
therapeutic target for obese asthma. Author information:
(1)Department of Chemical Drugs, Faculty of Pharmacy, University of Veterinary
and Pharmaceutical Sciences, Brno, Czech Republic.
(2)1st Department of Internal Medicine, Faculty of Medicine, Comenius University
in Bratislava and University Hospital, Bratislava, Slovakia.
(3)Department of Medical Biology, Jessenius Faculty of Medicine, Comenius
University in Bratislava, Martin, Slovakia; Department of Experimental
Carcinogenesis, Division of Oncology, Biomedical Center Martin, Jessenius
Faculty of Medicine, Comenius University in Bratislava, Martin, Slovakia.
(4)Mosjøen, Norway.
(5)Department of Obstetrics and Gynecology, Jessenius Faculty of Medicine,
Comenius University in Bratislava, Martin, Slovakia.
(6)Department of Neurology, Jessenius Faculty of Medicine, Comenius University
in Bratislava, Martin, Slovakia.
(7)Department of Medical and Clinical Biophysics, Faculty of Medicine, Pavol
Jozef Safarik University, Kosice, Slovakia.
(8)Department of Functional Sciences, Victor Babes University of Medicine and
Pharmacy, Timisoara, Romania.
(9)Institute of Histology and Embryology, Faculty of Medicine, University of
Ljubljana, Ljubljana, Slovenia.
(10)Department of Psychiatry, Faculty of Medicine, Pavol Jozef Safarik
University and University Hospital, Kosice, Slovakia.
(11)Department of Cardiology, National Institute of Cardiovascular Diseases and
Slovak Medical University, Bratislava, Slovakia.
(12)Weill Cornell Medicine in Qatar, Qatar Foundation-Education City, Doha,
Qatar.
(13)Centre for Chronic Disease (CCD), College of Health & Biomedicine, Victoria
University, Melbourne, Victoria, Australia.
(14)Faculty of Medicine, University of Oviedo, Central University Hospital of
Asturias (HUCA), Oviedo, Spain.
(15)Department of Chemical Drugs, Faculty of Pharmacy, University of Veterinary
and Pharmaceutical Sciences, Brno, Czech Republic; 2nd Department of Surgery,
Faculty of Medicine, Masaryk University and St. Anne´s University Hospital,
Brno, Czech Republic. Electronic address: [email protected].
(16)Department of Ophthalmology, Faculty of Medicine, Comenius University in
Bratislava and University Hospital, Bratislava, Slovakia. BACKGROUND: Resistin is an immunometabolic mediator that is elevated in several
inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates
the recruitment and activation of myeloid cells, notably neutrophils.
Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due
to the release of human neutrophil elastase- and myeloperoxidase-rich primary
granules, leading to tissue damage. Here we assessed the relationship of
resistin to CF lung disease.
METHODS: Resistin levels were measured in plasma and sputum from three
retrospective CF cohorts spanning a wide range of disease. We also assessed the
ability of neutrophils to secrete resistin upon activation in vitro. Finally, we
constructed a multivariate model assessing the relationship between resistin
levels and lung function.
RESULTS: Plasma resistin levels were only marginally higher in CF than in
healthy control subjects. By contrast, sputum resistin levels were very high in
CF, reaching 50-100 fold higher levels than in plasma. Among CF patients, higher
plasma resistin levels were associated with allergic bronchopulmonary
aspergillosis, and higher sputum resistin levels were associated with CF-related
diabetes. Mechanistically, in vitro release of neutrophil primary granules was
concomitant with resistin secretion. Overall, sputum resistin levels were
negatively correlated with CF lung function, independently of other variables
(age, sex, and genotype).
CONCLUSIONS: Our data establish relationships between resistin levels in the
plasma and sputum of CF patients that correlate with disease status, and
identify resistin as a novel mechanistic link between neutrophilic inflammation
and lung disease in CF. The adipokine resistin has been proposed to link obesity, insulin resistance and
diabetes. We have previously reported that diabetic hearts express high levels
of resistin while overexpression of resistin in adult rat hearts gives rise to a
phenotype resembling diabetic cardiomyopathy. The transcriptional regulation of
resistin in diabetic cardiac tissue is currently unknown. This study
investigated the mechanism of resistin upregulation and the role of Serca2a in
its transcriptional suppression. We demonstrate that restoration of Ca2+
homeostasis in diabetic hearts, through normalization of Serca2a function
genetically and pharmacologically, suppressed resistin expression via inhibition
of NFATc. H9c2 myocytes stimulated with high-glucose concentration or Ca2+
time-dependently increased NFATc and resistin expression while addition of the
Ca2+ chelator BAPTA-AM attenuated this effect. NFATc expression was enhanced in
hearts from ob/ob diabetic and from cardiac-specific Serca2a-/- mice. Similarly,
NFATc increased resistin expression in myocytes cultured in low glucose while
the NFATc inhibitor VIVIT blocked glucose-induced resistin expression,
suggesting that hyperglycemia/diabetes induces resistin expression possibly
through NFATc activation. Interestingly, overexpression of Serca2a or VIVIT
mitigated glucose-stimulated resistin and NFATc expression and enhanced AMPK
activity, a downstream target of resistin signaling. NFATc direct activation of
resistin was verified by resistin promoter luciferase activity and
chromatin-immunoprecipitation analysis. Interestingly, activation of Serca2a by
a novel agonist, CDN1163, mirrored the effects of AAV9-Serca2a gene transfer on
resistin expression and its promoter activity and AMPK signaling in diabetic
mice. These findings parse a role for Ca2+ in resistin transactivation and
provide support that manipulation of Serca2a-NFATc-Resistin axis might be useful
in hyper-resistinemic conditions. |
Is Pim-1 a protein phosphatase? | No,
Pim-1 is a kinase and not a phosphatase. | Pim-1 proto-oncogene, serine/threonine kinase (PIM-1) phosphorylates a series of
substrates to exert its oncogenic function in numerous maligcies. The present
study investigated the clinical significance of the PIM-1 protein, apoptosis
status and apoptosis-associated proteins, including forkhead box O3a (FOXO3a), B
cell lymphoma-2 (BCL-2) and BCL-2-associted agonist of cell death (BAD), were
investigated in salivary gland adenoid cystic carcinoma (ACC) tissues. PIM-1
expression levels in 4 pairs of ACC tissues and corresponding normal salivary
gland tissues were determined by western blot analysis. PIM-1, FOXO3a, BAD and
BCL-2 expression levels in 60 ACC tissues were evaluated by immunohistochemistry
(IHC). A terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling
assay was performed to detect the apoptosis status of ACC tissues. PIM-1 was
revealed to be highly expressed in ACC tissues compared with adjacent normal
tissues. IHC staining results demonstrated high expression ratios of PIM-1,
FOXO3a, BCL-2 and BAD [33.33% (20/60), 51.67% (31/60), 51.67% (31/60) and 55%
(33/60)], respectively, and significant correlations between the expression of
PIM-1 and FOXO3a and BCL-2 (P<0.05). Apoptotic rates were significantly
associated with PIM-1, FOXO3a, BCL-2 and BAD expression levels (P<0.05). PIM-1
expression levels were significantly associated with tumor size, lymph node
involvement, nerve invasion, distant metastasis and weakly associated with tumor
node metastasis stage. Kaplan-Meier survival curves revealed that PIM-1
expression level was significantly associated with disease-free survival of
patients with ACC (P=0.009). Cox regression multivariate analysis results
revealed that histotype, distant metastasis and apoptotic rate were independent
prognosis factors for ACC. Assessment of PIM-1 may be useful in investigating
the maligt behaviors of ACC and predicting the outcome of patients with ACC. |
Name three binding partners of cofilin 2. | Cofilin 2 can bind miR-201a, the protein 14-3-3, and ATP/ADP-Pi-actin filaments. | The muscle LIM protein (MLP) and cofilin 2 (CFL2) are important regulators of
striated myocyte function. Mutations in the corresponding genes have been
directly associated with severe human cardiac and skeletal myopathies, and
aberrant expression patterns have often been observed in affected muscles.
Herein, we have investigated whether MLP and CFL2 are involved in common
molecular mechanisms, which would promote our understanding of disease
pathogenesis. We have shown for the first time, using a range of biochemical and
immunohistochemical methods, that MLP binds directly to CFL2 in human cardiac
and skeletal muscles. The interaction involves the inter-LIM domain, amino acids
94 to 105, of MLP and the amino-terminal domain, amino acids 1 to 105, of CFL2,
which includes part of the actin depolymerization domain. The MLP/CFL2 complex
is stronger in moderately acidic (pH 6.8) environments and upon CFL2
phosphorylation, while it is independent of Ca(2+) levels. This interaction has
direct implications in actin cytoskeleton dynamics in regulating CFL2-dependent
F-actin depolymerization, with maximal depolymerization enhancement at an
MLP/CFL2 molecular ratio of 2:1. Deregulation of this interaction by
intracellular pH variations, CFL2 phosphorylation, MLP or CFL2 gene mutations,
or expression changes, as observed in a range of cardiac and skeletal
myopathies, could impair F-actin depolymerization, leading to sarcomere
dysfunction and disease. ADF/cofilins drive cytoskeletal dynamics by promoting the disassembly of "aged"
ADP-actin filaments. Mammals express several ADF/cofilin isoforms, but their
specific biochemical activities and cellular functions have not been studied in
detail. Here, we demonstrate that the muscle-specific isoform cofilin-2 promotes
actin filament disassembly in sarcomeres to control the precise length of thin
filaments in the contractile apparatus. In contrast to other isoforms, cofilin-2
efficiently binds and disassembles both ADP- and ATP/ADP-Pi-actin filaments. We
mapped surface-exposed cofilin-2-specific residues required for ATP-actin
binding and propose that these residues function as an "actin nucleotide-state
sensor" among ADF/cofilins. The results suggest that cofilin-2 evolved specific
biochemical and cellular properties that allow it to control actin dynamics in
sarcomeres, where filament pointed ends may contain a mixture of ADP- and
ATP/ADP-Pi-actin subunits. Our findings also offer a rationale for why cofilin-2
mutations in humans lead to myopathies. Calsarcin-1 deficient mice develop dilated cardiomyopathy (DCM) phenotype in
pure C57BL/6 genetic background (Cs1-ko) despite severe contractile dysfunction
and robust activation of fetal gene program. Here we performed a microRNA
microarray to identify the molecular causes of this cardiac phenotype that
revealed the dysregulation of several microRNAs including miR-301a, which was
highly downregulated in Cs1-ko mice compared to the wild-type littermates.
Cofilin-2 (Cfl2) was identified as one of the potential targets of miR-301a
using prediction databases, which we validated by luciferase assay and mutation
of predicted binding sites. Furthermore, expression of miR-301a contrastingly
regulated Cfl2 expression levels in neonatal rat ventricular cardiomyocytes
(NRVCM). Along these lines, Cfl2 was significantly upregulated in Cs1-ko mice,
indicating the physiological association between miR-301a and Cfl2 in vivo.
Mechanistically, we found that Cfl2 activated serum response factor response
element (SRF-RE) driven luciferase activity in neonatal rat cardiomyocytes and
in C2C12 cells. Similarly, knockdown of miR301a activated, whereas, its
overexpression inhibited the SRF-RE driven luciferase activity, further
strengthening physiological interaction between miR-301a and Cfl2.
Interestingly, the expression of SRF and its target genes was strikingly
increased in Cs1-ko suggesting a possible in vivo correlation between expression
levels of Cfl2/miR-301a and SRF activation, which needs to be independently
validated. In summary, our data demonstrates that miR-301a regulates Cofilin-2
in vitro in NRVCM, and in vivo in Cs1-ko mice. Our findings provide an
additional and important layer of Cfl2 regulation, which we believe has an
extended role in cardiac signal transduction and dilated cardiomyopathy
presumably due to the reported involvement of Cfl2 in these mechanisms. |
What is the function of GvpA? | The gas vesicle wall is solely formed of proteins with the two major components, GvpA and GvpC, and | Gas vesicle synthesis in Haloferax mediterranei involves several gene products
encoded by a 9.4-kilobase pair DNA region (mc-vac region) that contains 13 genes
in addition to gvpA encoding the major structural gas vesicle protein. The
expression of part of this region, encompassing the genes gvpA, gvpC, gvpN, and
gvpO was investigated. These genes are transcribed from a common promoter
located upstream of gvpA. Transcripts of 0.34 (gvpA only), 1.8 (gvpA/C), 2.4
(gvpA/C/N) and 3 kilobases (gvpA/C/N/O) were observed, with the gvpA transcript
being the predomit mRNA species. The majority of the mRNA formed terminates
64 base pairs downstream of gvpA at the cytosine of the sequence 5' TTTTTC 3'.
The synthesis of the GvpA and GvpC proteins was investigated by Western
analyses. An antiserum raised against isolated gas vesicles of Hf. mediterranei
detects, in addition to gas vesicle fragments, the GvpA protein of the M(r) of
approximately 8,000 in lysates derived from different halobacteria or from
Escherichia coli expressing gvpA. In samples containing isolated gas vesicles,
mainly partially disaggregated gas vesicle fragments hybridize, but a minor
amount of monomeric GvpA is also seen. For the detection of the GvpC protein,
two versions of the gvpC gene (full length and gvp delta C lacking the 3' part
encoding the acidic C terminus) were expressed in E. coli, and the resulting
proteins were purified. The two antisera raised against these GvpC versions
indicate the expression of gvpC in different halobacteria. By Western analysis,
GvpC is also detectable in samples containing isolated gas vesicles
demonstrating that GvpC is a second, but minor, gas vesicle structural protein. Gas vesicles are intracellular, microbial flotation devices that consist of
mainly one protein, GvpA. The formation of halobacterial gas vesicles occurs
along a complex pathway involving 14 different gvp genes that are clustered in a
genomic region termed the "vac region". Various vac regions found in
Halobacterium salinarum (p-vac and c-vac), Haloferax mediterranei (mc-vac), and
Natronobacterium vacuolatum (nv-vac) have been investigated. Except for the
latter vac region, the arrangement of the gvp genes is identical. Single gvp
genes have been mutated to study the effect on gas vesicle synthesis in
transformants and to determine their possible function. Each vac region exhibits
a characteristic transcription pattern, and regulatory steps have been observed
at the DNA, RNA, and protein level, indicating a complex regulatory network
acting during gas vesicle gene expression. The structure and assembly process of gas vesicles have received significant
attention in recent decades, although relatively little is still known. This
work combines state-of-the-art computational methods to develop a model for the
major gas vesicle protein, GvpA, and explore its structure within the assembled
vesicle. Elucidating this protein's structure has been challenging due to its
adherent and aggregative nature, which has so far precluded in-depth biochemical
analyses. Moreover, GvpA has extremely low similarity with any known protein
structure, which renders homology modeling methods ineffective. Thus, alternate
approaches were used to model its tertiary structure. Starting with the sequence
from haloarchaeon Halobacterium sp. NRC-1, we performed ab initio modeling and
threading to acquire a multitude of structure decoys, which were equilibrated
and ranked using molecular dynamics and mechanics, respectively. The highest
ranked predictions exhibited an α-β-β-α secondary structure in agreement with
earlier experimental findings, as well as with our own secondary structure
predictions. Afterwards, GvpA subunits were docked in a quasi-periodic
arrangement to investigate the assembly of the vesicle wall and to conduct
simulations of contact-mode atomic force microscopy imaging, which allowed us to
reconcile the structure predictions with the available experimental data.
Finally, the GvpA structure for two representative organisms, Anabaena
flos-aquae and Calothrix sp. PCC 7601, was also predicted, which reproduced the
major features of our GvpA model, supporting the expectation that homologous
GvpA sequences synthesized by different organisms should exhibit similar
structures. A range of bacteria and archaea produce intracellular gas-filled proteinaceous
structures that function as flotation devices in order to maintain a suitable
depth in the aqueous environment. The wall of these gas vesicles is freely
permeable to gas molecules and is composed of a small hydrophobic protein, GvpA,
which forms a single-layer wall. In addition, several minor structural,
accessory or regulatory proteins are required for gas vesicle formation. In
different organisms, 8-14 genes encoding gas vesicle proteins have been
identified, and their expression has been shown to be regulated by environmental
factors. In this Review, I describe the basic properties of gas vesicles, the
genes that encode them and how their production is regulated. I also discuss the
function of these vesicles and the initial attempts to exploit them for
biotechnological purposes. Halophilic Archaea (Haloarchaea) thrive in salterns containing sodium chloride
concentrations up to saturation. Many Haloarchaea possess genes encoding gas
vesicles, but only a few species, such as Halobacterium salinarum and Haloferax
mediterranei, produce these gas-filled, proteinaceous ocompartments. Gas
vesicles increase the buoyancy of cells and enable them to migrate vertically in
the water body to regions with optimal conditions. Their synthesis depends on
environmental factors, such as light, oxygen supply, temperature and salt
concentration. Fourteen gas vesicle protein (gvp) genes are involved in their
formation, and regulation of gvp gene expression occurs at the level of
transcription, including the two regulatory proteins, GvpD and GvpE, but also at
the level of translation. The gas vesicle wall is solely formed of proteins with
the two major components, GvpA and GvpC, and seven additional accessory proteins
are also involved. Except for GvpI and GvpH, all of these are required to form
the gas permeable wall. The applications of gas vesicles include their use as an
antigen presenter for viral or pathogen proteins, but also as a stable
ultrasonic reporter for biomedical purposes. Gas vesicles are proteinaceous, gas-filled ostructures produced by some
bacteria and archaea. The hydrophobic major structural protein GvpA forms the
ribbed gas vesicle wall. An in-silico 3D-model of GvpA of the predicted
coil-α1-β1-β2-α2-coil structure is available and implies that the two β-chains
constitute the hydrophobic interior surface of the gas vesicle wall. To test the
importance of individual amino acids in GvpA we performed 85 single
substitutions and analyzed these variants in Haloferax volcanii ΔA + Amut
transformants for their ability to form gas vesicles (Vac+ phenotype). In most
cases, an alanine substitution of a non-polar residue did not abolish gas
vesicle formation, but the replacement of single non-polar by charged residues
in β1 or β2 resulted in Vac- transformants. A replacement of residues near the
β-turn altered the spindle-shape to a cylindrical morphology of the gas
vesicles. Vac- transformants were also obtained with alanine substitutions of
charged residues of helix α1 suggesting that these amino acids form salt-bridges
with another GvpA monomer. In helix α2, only the alanine substitution of His53
or Tyr54, led to Vac- transformants, whereas most other substitutions had no
effect. We discuss our results in respect to the GvpA structure and data
available from solid-state NMR. |
What is a SMR based BCI? | Many Brain Computer Interface (BCI) and neurofeedback studies have investigated the impact of sensorimotor rhythm (SMR) | All brain-computer interface (BCI) groups that have published results of studies
involving a large number of users performing BCI control based on the voluntary
modulation of sensorimotor rhythms (SMR) report that BCI control could not be
achieved by a non-negligible number of subjects (estimated 20% to 25%). This
failure of the BCI system to read the intention of the user is one of the
greatest problems and challenges in BCI research. There are two main causes for
this problem in SMR-based BCI systems: either no idle SMR is observed over motor
areas of the user, or this idle rhythm is not modulated during motor imagery,
resulting in a classification performance lower than 70% (criterion level) that
renders the control of a BCI application (like a speller) difficult or
impossible. Previously, we introduced the concept of machine learning based
co-adaptive calibration, which provided substantially improved performance for a
variety of users. Here, we use a similar approach and investigate to what extent
co-adaptive learning enables significant BCI control for completely novice
users, as well as for those who could not achieve control with a conventional
SMR-based BCI. OBJECTIVE: It is well known that to acquire sensorimotor (SMR)-based
brain-computer interface (BCI) control requires a training period before users
can achieve their best possible performances. Nevertheless, the effect of this
training procedure on the cortical activity related to the mental imagery
ability still requires investigation to be fully elucidated. The aim of this
study was to gain insights into the effects of SMR-based BCI training on the
cortical spectral activity associated with the performance of different mental
imagery tasks.
APPROACH: Linear cortical estimation and statistical brain mapping techniques
were applied on high-density EEG data acquired from 18 healthy participants
performing three different mental imagery tasks. Subjects were divided in two
groups, one of BCI trained subjects, according to their previous exposure (at
least six months before this study) to motor imagery-based BCI training, and one
of subjects who were naive to any BCI paradigms.
MAIN RESULTS: Cortical activation maps obtained for trained and naive subjects
indicated different spectral and spatial activity patterns in response to the
mental imagery tasks. Long-term effects of the previous SMR-based BCI training
were observed on the motor cortical spectral activity specific to the BCI
trained motor imagery task (simple hand movements) and partially generalized to
more complex motor imagery task (playing tennis). Differently, mental imagery
with spatial attention and memory content could elicit recognizable cortical
spectral activity even in subjects completely naive to (BCI) training.
SIGNIFICANCE: The present findings contribute to our understanding of BCI
technology usage and might be of relevance in those clinical conditions when
training to master a BCI application is challenging or even not possible. In the last years Brain Computer Interface (BCI) technology has benefited from
the development of sophisticated machine leaning methods that let the user
operate the BCI after a few trials of calibration. One remarkable example is the
recent development of co-adaptive techniques that proved to extend the use of
BCIs also to people not able to achieve successful control with the standard BCI
procedure. Especially for BCIs based on the modulation of the Sensorimotor
Rhythm (SMR) these improvements are essential, since a not negligible percentage
of users is unable to operate SMR-BCIs efficiently. In this study we evaluated
for the first time a fully automatic co-adaptive BCI system on a large scale. A
pool of 168 participants naive to BCIs operated the co-adaptive SMR-BCI in one
single session. Different psychological interventions were performed prior the
BCI session in order to investigate how motor coordination training and
relaxation could influence BCI performance. A neurophysiological indicator based
on the Power Spectral Density (PSD) was extracted by the recording of few
minutes of resting state brain activity and tested as predictor of BCI
performances. Results show that high accuracies in operating the BCI could be
reached by the majority of the participants before the end of the session. BCI
performances could be significantly predicted by the neurophysiological
indicator, consolidating the validity of the model previously developed. Anyway,
we still found about 22% of users with performance significantly lower than the
threshold of efficient BCI control at the end of the session. Being the
inter-subject variability still the major problem of BCI technology, we pointed
out crucial issues for those who did not achieve sufficient control. Finally, we
propose valid developments to move a step forward to the applicability of the
promising co-adaptive methods. OBJECTIVE: Brain-computer interface (BCI) technology is attracting increasing
interest as a tool for enhancing recovery of motor function after stroke, yet
the optimal way to apply this technology is unknown. Here, we studied the
immediate and therapeutic effects of BCI-based training to control pre-movement
sensorimotor rhythm (SMR) amplitude on robot-assisted finger extension in people
with stroke.
APPROACH: Eight people with moderate to severe hand impairment due to chronic
stroke completed a four-week three-phase protocol during which they practiced
finger extension with assistance from the FINGER robotic exoskeleton. In Phase
1, we identified spatiospectral SMR features for each person that correlated
with the intent to extend the index and/or middle finger(s). In Phase 2, the
participants learned to increase or decrease SMR features given visual feedback,
without movement. In Phase 3, the participants were cued to increase or decrease
their SMR features, and when successful, were then cued to immediately attempt
to extend the finger(s) with robot assistance.
MAIN RESULTS: Of the four participants that achieved SMR control in Phase 2,
three initiated finger extensions with a reduced reaction time after decreasing
(versus increasing) pre-movement SMR amplitude during Phase 3. Two also extended
at least one of their fingers more forcefully after decreasing pre-movement SMR
amplitude. Hand function, measured by the box and block test (BBT), improved by
7.3 ± 7.5 blocks versus 3.5 ± 3.1 blocks in those with and without SMR
control, respectively. Higher BBT scores at baseline correlated with a larger
change in BBT score.
SIGNIFICANCE: These results suggest that learning to control person-specific
pre-movement SMR features associated with finger extension can improve finger
extension ability after stroke for some individuals. These results merit further
investigation in a rehabilitation context. Many Brain Computer Interface (BCI) and neurofeedback studies have investigated
the impact of sensorimotor rhythm (SMR) self-regulation training procedures on
motor skills enhancement in healthy subjects and patients with motor
disabilities. This critical review aims first to introduce the different
definitions of SMR EEG target in BCI/Neurofeedback studies and to summarize the
background from neurophysiological and neuroplasticity studies that led to SMR
being considered as reliable and valid EEG targets to improve motor skills
through BCI/neurofeedback procedures. The second objective of this review is to
introduce the main findings regarding SMR BCI/neurofeedback in healthy subjects.
Third, the main findings regarding BCI/neurofeedback efficiency in patients with
hypokinetic activities (in particular, motor deficit following stroke) as well
as in patients with hyperkinetic activities (in particular, Attention Deficit
Hyperactivity Disorder, ADHD) will be introduced. Due to a range of limitations,
a clear association between SMR BCI/neurofeedback training and enhanced motor
skills has yet to be established. However, SMR BCI/neurofeedback appears
promising, and highlights many important challenges for clinical neurophysiology
with regards to therapeutic approaches using BCI/neurofeedback. |
Is myc a tumour suppressor gene? | No,
Myc is a proto-oncogene. | RhoA regulates actin cytoskeleton but recent evidence suggest a role for this
conserved Rho GTPase also in other cellular processes, including transcriptional
control of cell proliferation and survival. Interestingy, loss of RhoA is
synthetic lethal with oncogenic Myc, a master transcription factor that turns on
anabolic metabolism to promote cell growth in many cancers. We show evidence
indicating that the synthetic lethal interaction between RhoA loss and Myc
arises from deficiency in glutamine utilization, resulting from impaired
co-regulation of glutaminase expression and anaplerosis by Myc and RhoA - serum
response factor (SRF) pathway. The results suggest metabolic coordination
between Myc and RhoA/SRF in sustaining cancer cell viability and indicate
RhoA/SRF as a potential vulnerability in cancer cells for therapeutic targeting. |
Which syndrome is associated to SAMHD1 gene mutations? | Mutations in the SAMHD1 gene that cause the severe autoimmune disease, Aicardi-Goutieres syndrome (AGS). | |
List proteins with RING domain. | RING1
TRIM proteins
TRAF6
UHRF1
MARCH7
SINA
BRCA1 | Autophagy is the process of degradation of intracellular proteins through the
lysosome. Members of the tripartite motif (TRIM) proteins have shown to directly
recognize autophagic cargo and also to act as a hub for the phagophore
nucleation complex. The TRIM proteins are classically characterized by the
presence of an amino-terminal RING domain and a B-box domain followed by a
coiled coil domain. Although regarded as ubiquitin E3 ligases, this activity has
been shown only for a minor set of the 79 human TRIM proteins. Additionally, the
role of each domain in the E3 ligase activity is unknown. We investigated the
role of the SPRY and RING domains of the human TRIM49 protein in its E3
ubiquitin ligase activity. Wild-type and mutant constructs of tagged TRIM49 were
expressed in E. coli or mammalian cells, and the autoubiquitination activity of
the purified protein was assessed. The purified TRIM49 showed no ubiquitin E3
ligase activity in vitro. However, cells transfected with the wild-type or
mutant protein showed increased levels of lower mass polyubiquitinated proteins
and both proteins copurified with polyubiquitinated proteins. Taken together,
these results indicate that the TRIM49 protein plays a role in autophagic
protein degradation independently of an ubiquitin E3 ligase activity. As a component of the transcriptional repression complex 1 (PRC1), the ring
finger protein RING1 participates in the epigenetic regulation in cancer.
However, the contributions of RING1 to cancer etiology or development are
unknown. In this study, we report that RING1 is a critical negative regulator of
p53 homeostasis in human hepatocellular and colorectal carcinomas. RING1 acts as
an E3 ubiquitin (Ub) ligase to directly interact with and ubiquitinate p53,
resulting in its proteasome-dependent degradation. The RING domain of RING1 was
required for its E3 Ub ligase activity. RING1 depletion inhibited the
proliferation and survival of the p53 wild-type cancer cells by inducing
cell-cycle arrest, apoptosis, and senescence, with only modest effects on
p53-deficient cells. Its growth inhibitory effect was partially rescued by p53
silencing, suggesting an important role for the RING1-p53 complex in human
cancer. In clinical specimens of hepatocellular carcinoma, RING1 upregulation
was evident in association with poor clinical outcomes. Collectively, our
results elucidate a novel PRC1-independent function of RING1 and provide a
mechanistic rationale for its candidacy as a new prognostic marker and/or
therapeutic target in human cancer.Significance: These results elucidate a novel
PRC1-independent function of RING1 and provide a mechanistic rationale for its
candidacy as a new prognostic marker and/or therapeutic target in human cancer.
Cancer Res; 78(2); 359-71. ©2017 AACR. The tumor suppressor p53 plays a prominent role in the protection against
cancer. The activity of p53 is mainly controlled by the ubiquitin E3 ligase
Mdm2, which targets p53 for proteasomal degradation. However, the regulation of
Mdm2 remains not well understood. Here, we show that MARCH7, a RING
domain-containing ubiquitin E3 ligase, physically interacts with Mdm2 and is
essential for maintaining the stability of Mdm2. MARCH7 catalyzes Lys63-linked
polyubiquitination of Mdm2, which impedes Mdm2 autoubiquitination and
degradation, thereby leading to the stabilization of Mdm2. MARCH7 also promotes
Mdm2-dependent polyubiquitination and degradation of p53. Furthermore, MARCH7 is
able to regulate cell proliferation, DNA damage-induced apoptosis, and
tumorigenesis via a p53-dependent mechanism. These findings uncover a novel
mechanism for the regulation of Mdm2 and reveal MARCH7 as an important regulator
of the Mdm2-p53 pathway. Seven in absentia (SINA) protein is one subgroup of ubiquitin ligases possessing
an N-terminal cysteine-rich really interesting new gene (RING) domain, two
zinc-finger motifs, and a C-terminal domain responsible for substrate-binding
and dimerization. In tomato (Solanum lycopersicum), the SINA gene family has six
members, and we characterize in this study all tomato SINA (SlSINA) genes and
the gene products. Our results show that SlSINA genes are differentially
regulated in leaf, bud, stem, flower, and root. All SlSINA proteins possess
RING-dependent E3 ubiquitin ligase activity, exhibiting similar specificity
towards the E2 ubiquitin-conjugating enzyme. SlSINA1/3/4/5/6 are localized in
both cytoplasm and nucleus, whereas SlSINA2 is exclusively localized in the
nucleus. Moreover, all SlSINAs can interact with each other for homo- or
hetero-dimerization. The functionality of SlSINA proteins has been investigated.
SlSINA4 plays a positive role in defense signalling, as manifested by
elicitation of E3-dependent hypersensitive response-like cell death; the other
SlSINAs are negative regulator and capable to suppress hypersensitive response
cell death. Transgenic tomato plants overexpressing SlSINA2 exhibit pale-green
leaf phenotype, suggesting SlSINA2 regulates chlorophyll level in plant cells,
whereas transgenic tomato plants overexpressing SlSINA5 have altered floral
structure with exserted stigma, implicating SlSINA5 plays a role in flower
development. Missense mutations that disrupt the RING domain of the tumor suppressor gene
BRCA1 lead to increased risk of breast and ovarian cancer. The BRCA1 RING domain
is a ubiquitin ligase, whose structure and function rely critically on forming a
heterodimer with BARD1, which also harbors a RING domain. The function of the
BARD1 RING domain is unknown. In families severely affected with breast cancer,
we identified inherited BARD1 missense mutations Cys53Trp, Cys71Tyr, and
Cys83Arg that alter three zinc-binding residues of the BARD1 RING domain. Each
of these mutant BARD1 proteins retained the ability to form heterodimeric
complexes with BRCA1 to make an active ubiquitin ligase, but the mutant
BRCA1/BARD1 complexes were deficient in binding to nucleosomes and in
ubiquitylating histone H2A. The BARD1 mutations also caused loss of
transcriptional repression of BRCA1-regulated estrogen metabolism genes CYP1A1
and CYP3A4; breast epithelial cells edited to create heterozygous loss of BARD1
showed significantly higher expression of CYP1A1 and CYP3A4 Reintroduction of
wild-type BARD1 into these cells restored CYP1A1 and CYP3A4 transcription to
normal levels, but introduction of the cancer-predisposing BARD1 RING mutants
failed to do so. These results indicate that an intact BARD1 RING domain is
critical to BRCA1/BARD1 binding to nucleosomes and hence to ubiquitylation of
histone H2A and also critical to transcriptional repression of BRCA1-regulated
genes active in estrogen metabolism. Germ-line mutations in breast cancer susceptibility gene, BRCA1, result in
familial predisposition to breast and ovarian cancers. The BRCA1 protein has
multiple functional domains that interact with a variety of proteins in multiple
cellular processes. Understanding the biological consequences of BRCA1
interactions with its binding partners is important for elucidating its
tissue-specific tumor suppression function. The Cofactor of BRCA1 (COBRA1) is a
BRCA1-binding protein that, as a component of negative elongation factor (NELF),
regulates RNA polymerase II pausing during transcription elongation. We recently
identified a genetic interaction between mouse Brca1 and Cobra1 that
antagonistically regulates mammary gland development. However, it remains
unclear which of the myriad functions of Brca1 are required for its genetic
interaction with Cobra1. Here, we show that, unlike deletion of Brca1 exon 11,
separation-of-function mutations that abrogate either the E3 ligase activity of
its RING domain or the phospho-recognition property of its BRCT domain are not
sufficient to rescue the mammary developmental defects in Cobra1 knockout mice.
Furthermore, deletion of mouse Palb2, another breast cancer susceptibility gene
with functional similarities to BRCA1, does not rescue Cobra1
knockout-associated mammary defects. Thus, the Brca1/Cobra1 genetic interaction
is both domain- and gene-specific in the context of mammary gland development. Tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6) plays a vital
role in immune signal transduction pathways by acting as a ubiquitin ligase (E3)
for Lys63-linked polyubiquitin chain synthesis. However, the detailed mechanism
by which the TRAF6 RING dimer promotes ubiquitin transfer was unknown. Through
structural modeling and biochemical analysis, we here show that the TRAF6 RING
dimer employs a concerted allosteric mechanism using both subunits of the TRAF6
dimer to promote ubiquitin (Ub) transfer. In particular, we reveal the
importance of the C-terminal extension of the TRAF6 RING domain that mediates
trans-interactions with the donor-Ub. By analyzing structures and models of E3s
in complex with Ub-loaded ubiquitin-conjugating enzymes (E2s), we further
highlight the roles of N-terminal and C-terminal extensions beyond the bona fide
RING domains in promoting Ub transfer through engagement with a donor-Ub in cis
and in trans, respectively. |
What conditions are associated with mutations in the gene FAAH? | Human FAAH gene mutations are associated with increased body weight and obesity. Results suggest that genetic mutations in FAAH may constitute important risk factors for problem drug use and support a potential link between functional abnormalities in the endogenous cannabinoid system and drug abuse and dependence.
research on the genetic modulation of pain has already identified variants in these genes, relative to pain, which may facilitate the pharmacogenetic assessments of new analgesics. | Fatty acid amide hydrolase (FAAH) is a mammalian integral membrane enzyme
responsible for the hydrolysis of a number of neuromodulatory fatty acid amides,
including the endogenous cannabinoid adamide and the sleep-inducing lipid
oleamide. FAAH belongs to a large class of hydrolytic enzymes termed the
"amidase signature family," whose members are defined by a conserved stretch of
approximately 130 amino acids termed the "amidase signature sequence." Recently,
site-directed mutagenesis studies of FAAH have targeted a limited number of
conserved residues in the amidase signature sequence of the enzyme, identifying
Ser-241 as the catalytic nucleophile and Lys-142 as an acid/base catalyst. The
roles of several other conserved residues with potentially important and/or
overlapping catalytic functions have not yet been examined. In this study, we
have mutated all potentially catalytic residues in FAAH that are conserved among
members of the amidase signature family, and have assessed their individual
roles in catalysis through chemical labeling and kinetic methods. Several of
these residues appear to serve primarily structural roles, as their mutation
produced FAAH variants with considerable catalytic activity but reduced
expression in prokaryotic and/or eukaryotic systems. In contrast, five
mutations, K142A, S217A, S218A, S241A, and R243A, decreased the amidase activity
of FAAH greater than 100-fold without detectably impacting the structural
integrity of the enzyme. The pH rate profiles, amide/ester selectivities, and
fluorophosphonate reactivities of these mutants revealed distinct catalytic
roles for each residue. Of particular interest, one mutant, R243A, displayed
uncompromised esterase activity but severely reduced amidase activity,
indicating that the amidase and esterase efficiencies of FAAH can be
functionally uncoupled. Collectively, these studies provide evidence that
amidase signature enzymes represent a large class of serine-lysine catalytic
dyad hydrolases whose evolutionary distribution rivals that of the catalytic
triad superfamily. Problem drug use and dependence are neurobehavioral disorders of complex origin.
Although environmental factors contribute to drug abuse and addiction, genetic
factors also play a significant role estimated at 40-60% of the total risk.
Nonetheless, the precise identities of human genes that confer vulnerability to
problem drug use remain mostly unknown. Here, we describe a natural single
nucleotide polymorphism in the human gene that encodes the principal
endocannabinoid-inactivating enzyme, fatty acid amide hydrolase (FAAH), that in
homozygous form is strongly associated with both street drug use and problem
drug/alcohol use. This single nucleotide polymorphism results in a missense
mutation (385C-->A) that converts a conserved proline residue to threonine
(Pro129-->Thr), producing a FAAH variant that displays normal catalytic
properties but an enhanced sensitivity to proteolytic degradation. Collectively,
these results suggest that genetic mutations in FAAH may constitute important
risk factors for problem drug use and support a potential link between
functional abnormalities in the endogenous cannabinoid system and drug abuse and
dependence. BACKGROUND: Obesity is a worldwide epidemic, and severe obesity is a risk factor
for many diseases, including diabetes, heart disease, stroke, and some cancers.
Endocannabinoid system (ECS) signaling in the brain and peripheral tissues is
activated in obesity and plays a role in the regulation of body weight. The main
research question here was whether quantitative measurement of plasma
endocannabinoids, adamide, and related N-acylethanolamines (NAEs), combined
with genotyping for mutations in fatty acid amide hydrolase (FAAH) would
identify circulating biomarkers of ECS activation in severe obesity.
METHODOLOGY/PRINCIPAL FINDINGS: Plasma samples were obtained from 96 severely
obese subjects with body mass index (BMI) of > or = 40 kg/m(2), and 48 normal
weight subjects with BMI of < or = 26 kg/m(2). Triple-quadrupole mass
spectroscopy methods were used to measure plasma ECS analogs. Subjects were
genotyped for human FAAH gene mutations. The principal analysis focused on the
FAAH 385 C-->A (P129T) mutation by comparing plasma ECS metabolite levels in the
FAAH 385 minor A allele carriers versus wild-type C/C carriers in both groups.
The main finding was significantly elevated mean plasma levels of adamide
(15.1+/-1.4 pmol/ml) and related NAEs in study subjects that carried the FAAH
385 A mutant alleles versus normal subjects (13.3+/-1.0 pmol/ml) with wild-type
FAAH genotype (p = 0.04), and significance was maintained after controlling for
BMI.
CONCLUSIONS/SIGNIFICANCE: Significantly increased levels of the endocannabinoid
adamide and related NAEs were found in carriers of the FAAH 385 A mutant
alleles compared with wild-type FAAH controls. This evidence supports
endocannabinoid system activation due to the effect of FAAH 385 mutant A
genotype on plasma AEA and related NAE analogs. This is the first study to
document that FAAH 385 A mutant alleles have a direct effect on elevated plasma
levels of adamide and related NAEs in humans. These biomarkers may indicate
risk for severe obesity and may suggest novel ECS obesity treatment strategies. BACKGROUND: FAAH (fatty acid amide hydrolase), primarily expressed in the liver,
hydrolyzes the endocannabinoids fatty acid ethanolamides (FAA). Human FAAH gene
mutations are associated with increased body weight and obesity. In our present
study, using targeted metabolite and lipid profiling, and new global acetylome
profiling methodologies, we examined the role of the liver on fuel and energy
homeostasis in whole body FAAH(-/-) mice.
METHODOLOGY/PRINCIPAL FINDINGS: FAAH(-/-) mice exhibit altered energy
homeostasis demonstrated by decreased oxygen consumption (Indirect calorimetry).
FAAH(-/-) mice are hyperinsulinemic and have adipose, skeletal and hepatic
insulin resistance as indicated by stable isotope phenotyping (SIPHEN). Fed
state skeletal muscle and liver triglyceride levels was increased 2-3 fold,
while glycogen was decreased 42% and 57% respectively. Hepatic cholesterol
synthesis was decreased 22% in FAAH(-/-) mice. Dysregulated hepatic FAAH(-/-)
lysine acetylation was consistent with their metabolite profiling. Fasted to fed
increases in hepatic FAAH(-/-) acetyl-CoA (85%, p<0.01) corresponded to similar
increases in citrate levels (45%). Altered FAAH(-/-) mitochondrial malate
dehydrogenase (MDH2) acetylation, which can affect the malate aspartate shuttle,
was consistent with our observation of a 25% decrease in fed malate and
aspartate levels. Decreased fasted but not fed dihydroxyacetone-P and
glycerol-3-P levels in FAAH(-/-) mice was consistent with a compensating
contribution from decreased acetylation of fed FAAH(-/-) aldolase B. Fed
FAAH(-/-) alcohol dehydrogenase (ADH) acetylation was also decreased.
CONCLUSIONS/SIGNIFICANCE: Whole body FAAH deletion contributes to a pre-diabetic
phenotype by mechanisms resulting in impairment of hepatic glucose and lipid
metabolism. FAAH(-/-) mice had altered hepatic lysine acetylation, the pattern
sharing similarities with acetylation changes reported with chronic alcohol
treatment. Dysregulated hepatic lysine acetylation seen with impaired FAA
hydrolysis could support the liver's role in fostering the pre-diabetic state,
and may reflect part of the mechanism underlying the hepatic effects of
endocannabinoids in alcoholic liver disease mouse models. INTRODUCTION: The consumption of marijuana (exogenous cannabinoid) almost
doubled in adults during last decade. Consumption of exogenous cannabinoids
interferes with the endogenous cannabinoid (or "endocannabinoid" (eCB)) system
(ECS), which comprises N-arachidonylethanolamide (adamide, AEA),
2-arachidonoyl glycerol (2-AG), endocannabinoid receptors (cannabinoid receptors
1 and 2 (CB1R and CB2R), encoded by CNR1 and CNR2, respectively), and
synthesizing/degrading enzymes (FAAH, fatty-acid amide hydrolase; MAGL,
monoacylglycerol lipase; DAGL-α, diacylglycerol lipase-alpha). Reports regarding
the toxic and therapeutic effects of pharmacological compounds targeting the ECS
are sometimes contradictory. This may be caused by the fact that structure of
the eCBs varies in the species studied.
OBJECTIVES: First: to clone and characterize the cDNAs of selected members of
ECS in a non-human primate (baboon, Papio spp.), and second: to compare those
cDNA sequences to known human structural variants (single nucleotide
polymorphisms and haplotypes).
MATERIALS AND METHODS: Polymerase chain reaction-amplified gene products from
baboon tissues were transformed into Escherichia coli. Amplicon-positive clones
were sequenced, and the obtained sequences were conceptually translated into
amino-acid sequences using the genetic code.
RESULTS: Among the ECS members, CNR1 was the best conserved gene between humans
and baboons. The phenotypes associated with mutations in the untranslated
regions of this gene in humans have not been described in baboons. One
difference in the structure of CNR2 between humans and baboons was detected in
the region with the only known clinically relevant polymorphism in a human
receptor. All of the differences in the amino-acid structure of DAGL-α between
humans and baboons were located in the hydroxylase domain, close to
phosphorylation sites. None of the differences in the amino-acid structure of
MAGL observed between baboons and humans were located in the area critical for
enzyme function.
CONCLUSION: The evaluation of the data, obtained in non-human primate model of
cannabis-related developmental exposure should take into consideration possible
evolutionary-determined species-specific differences in the CB1R expression,
CB2R transduction pathway, and FAAH and DAGLα substrate-enzyme interactions. |
What is the results of mutations in the gene autoimmune regulator? | Autoimmune-polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a primary immunodeficiency caused by mutations in the autoimmune regulator gene (AIRE) | Protection against mucocutaneous candidiasis depends on the T helper (Th)17
pathway, as gene defects affecting its integrity result in inability to clear
Candida albicans infection on body surfaces. Moreover, autoantibodies
neutralizing Th17 cytokines have been related to chronic candidiasis in a rare
inherited disorder called autoimmune polyendocriopathy candidiasis ectodermal
dystrophy (APECED) caused by mutations in autoimmune regulator (AIRE) gene.
However, the direct pathogenicity of these autoantibodies has not yet been
addressed. Here we show that the level of anti-IL17A autoantibodies that develop
in aged Aire-deficient mice is not sufficient for conferring susceptibility to
oropharyngeal candidiasis. However, patient-derived monoclonal antibodies that
cross-react with murine IL-22 increase the fungal burden on C. albicans infected
mucosa. Nevertheless, the lack of macroscopically evident infectious pathology
on the oral mucosa of infected mice suggests that additional susceptibility
factors are needed to precipitate a clinical disease. The autoimmune regulator gene (AIRE) is a transcription factor expressed both in
the thymus, by medullary thymic epithelial cells, and in secondary lymphoid
organs. AIRE controls the local transcription of organ- specific proteins
typically expressed in peripheral tissues, thus allowing the negative selection
of self- reactive T cells. The crucial role played by AIRE in central immune
tolerance emerged in the studies on the pathogenesis of Autoimmune
Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy, a rare inherited
polyendocrine/autoimmune disease. Thereafter, several studies found evidences
indicating that AIRE impairment might be pathogenically involved in several
autoimmune diseases and in tumorigenesis. In this review, we focus on recent
advances relative to AIRE's effect on T cell development in physiology and
disease. In particular, we address the following issues: 1) AIRE function and
mTECs biology, 2) the impact of AIRE gene mutations in autoimmune diseases, and
3) the role of AIRE gene in anti-tumor immune response. Autoimmune polyendocrine syndrome type 1 (APS-1; OMIM #240300), also referred to
as autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), is a
rare monogenic autoimmune disorder caused by mutations in the autoimmune
regulator (AIRE) gene. APS-1 is classically characterized by a triad of chronic
mucocutaneous candidiasis, autoimmune hypoparathyroidism, and autoimmune
adrenocortical insufficiency. We report a 5-yr-old female who presented with
symptoms of tetany due to hypocalcemia and was subsequently found to be
secondary to hypoparathyroidism. Rapid trio whole-genome sequencing revealed
compound heterozygous variants in AIRE in the proband, with a paternally
inherited, pathogenic, frameshift variant (c.1265delC; p.Pro422LeufsTer58) and a
novel, likely pathogenic, maternally inherited missense variant (c.268T>C;
p.Tyr90His). Autoimmune-polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a
primary immunodeficiency caused by mutations in the autoimmune regulator gene
(AIRE). Patients with AIRE mutations are susceptible to Candida albicans
infection and present with autoimmune disorders. We previously demonstrated that
cytoplasmic AIRE regulates the Syk-dependent Dectin-1 pathway. In this study, we
further evaluated direct contact with fungal elements, synapse formation, and
the response of macrophage-like THP-1 cells to C. albicans hyphae to determine
the role of AIRE upon Dectin receptors function and signaling. We examined the
fungal synapse (FS) formation in wild-type and AIRE-knockdown THP-1 cells
differentiated to macrophages, as well as monocyte-derived macrophages from
APECED patients. We evaluated Dectin-2 receptor signaling, phagocytosis, and
cytokine secretion upon hyphal stimulation. AIRE co-localized with Dectin-2 and
Syk at the FS upon hyphal stimulation of macrophage-like THP-1 cells.
AIRE-knockdown macrophage-like THP-1 cells exhibited less Dectin-1 and Dectin-2
receptors accumulation, decreased signaling pathway activity at the FS, lower C.
albicans phagocytosis, and less lysosome formation. Furthermore, IL-1β, IL-6, or
TNF-α secretion by AIRE-knockdown macrophage-like THP-1 cells and AIRE-deficient
patient macrophages was decreased compared to control cells. Our results suggest
that AIRE modulates the FS formation and hyphal recognition and help to
orchestrate an effective immune response against C. albicans. |
Is CD63 an exosomal marker? | Yes,
CD63 is a exosomal marker | Exosomes is a key component of cell paracrine secretion and can exert important
effects in various disease models. However, the role of exosomes in neuron
repair of spinal cord injury (SCI) has rarely been reported. In this study,
Exosomes were isolated from cerebrospinal fluid of SCI and normal, and incubated
neuron in vitro respectively to research its biological function in cell
proliferation. The results demonstrated these exosomes all expressed CD9, CD63,
CD81, Alix and Tsg101; however, only exosomes derived from cerebrospinal fluid
of SCI could promote proliferation of neuron via ERK signaling pathway, and
decrease cell apoptosis. Exosomes contain cytosolic content, including proteins,
mRNAs and non-cording RNAs, and play a role in important biological function.
Our research showed exosomes derived from cerebrospinal fluid of SCI, they can
influence neuron cell proliferation in vitro, we did not observe these
characters in exosome derived from normal cerebrospinal fluid. Exosomes are produced from mammalian cells when multivesicular endosomes fuse
with the plasma membrane, releasing their intralumenal vesicles. In this study
we assessed the effects of MOPIPP, a novel indole-based chalcone, and
vacuolin-1, a distinct triazine-based compound, on exosome production in
cultured glioblastoma and 293T cells. Both compounds promote vacuolization of
late endosome compartments and interfere with trafficking of late endosomes to
lysosomes, without significant cytotoxicity. The results show that vacuolated
cells treated with these compounds release exosomes with morphologies similar to
untreated controls. However, both compounds trigger multi-fold increases in
release of exosome marker proteins (e.g., CD63, Alix) in exosome fractions
collected from equivalent numbers of cells. Despite the marked increase in
exosome production, the profiles of selected miRNA cargoes carried by the
exosomes were generally similar in cells treated with the compounds. Insofar as
MOPIPP and vacuolin-1 seem able to increase the overall yield of exosomes from
cultured cells, they might be useful for efforts to develop exosome-based
therapeutics. |
Is subdural empyema a complication of sinusitis? | Yes, subdural empyema can be a complication of sinusitis | Despite the availability of new broad-spectrum antibiotics, sinusitis
occasionally causes significant morbidity and mortality. One serious
complication of paranasal sinusitis is subdural empyema, a fulminating
intracranial disease that is invariably fatal if not treated. The symptoms of
subdural empyema may be mild and may be the same as those associated with
sinusitis, or the infection may result in alteration of the level of
consciousness and focal neurologic deficits. Rapid recognition and treatment of
subdural empyema is extremely important. Before magnetic resoce imaging
became available, computed tomography was used for rapid diagnosis of this
infection. Magnetic resoce imaging, however, is now becoming the diagnostic
tool of choice. Neurosurgical intervention and high doses of intravenously
administered antibiotics are the mainstays of treatment. If treatment is
initiated as soon as the diagnosis of subdural empyema is made, the patient has
a good chance of recovering with no, or only slight, neurologic defects. Subdural empyema is a rare but serious complication of paranasal sinusitis which
may result in death or permanent disability in a significant proportion of
cases. A case is presented in which displacement of a premolar root in the
maxillary sinus led to a subdural empyema and a resultant left-sided hemiplegia.
This case illustrates the necessity of early surgical intervention to remove
displaced roots in the maxillary antrum in order to prevent the serious
complications of paranasal sinusitis. We present a case of frontal sinusitis complicated with a subdural empyema, in
which the identified microorganism was Gemella morbillorum, a frequent host of
the aerodigestive tract and occasionally related to infections. The problem was
resolved successfully using endoscopic surgery and an external approach of the
sinus. Afterwards it was completed with a subdural drainage through craniotomy.
Subdural empyema is a rare complication of sinusitis although very severe. We
want to emphasize the importance of early diagnosis of intracranial
complications, the need of a detailed microbiology test the method used to
obtain samples, and the convenience of a combined approach by the
otolaryngologists and the neurosurgeons for its complete drainage. Subdural empyema represents loculated infection between the outermost layer of
the meninges, the dura, and the arachnoid. The empyema may develop
intracranially or in the spinal canal. Intracranial subdural empyema is most
frequently a complication of sinusitis or, less frequently, otitis or
neurosurgical procedures. Spinal subdural empyema is rare and may result from
hematogenous infection or spread of infection from osteomyelitis. The most
common organisms in intracranial subdural empyema are anaerobic and
microaerophilic streptococci, in particular those of the Streptococcus milleri
group (S. milleri and Streptococcus anginosus). Staphylococcus aureus is present
in a minority of cases, and multiple additional organisms, including
Gram-negative organisms, such as Escherichia coli, and anaerobic organisms, such
as Bacteroides, may be present. Pseudomonas aeruginosa or Staphylococcus
epidermidis may be present in cases related to neurosurgical procedures, and
Salmonella species have been detected in patients with advanced AIDS; multiple
organisms may be present simultaneously. Spinal subdural empyemas are almost
invariably caused by streptococci or by S. aureus. Subdural empyema--whether it
occurs in the skull or the spinal canal--may cause rapid compression of the
brain or spinal cord, and represents an extreme medical and neurosurgical
emergency. The diagnostic procedure of choice for intracranial and spinal
subdural empyema is MRI with gadolinium enhancement. Computed tomography scan
may miss intracranial subdural empyemas detectable by MRI. Conversely, occasion
spinal subdural empyemas may be detected by CT myelography where MRI is
negative. Treatment in virtually all cases of intracranial or spinal subdural
empyema requires prompt surgical drainage and antibiotic therapy. Pus from the
empyema should always be sent for anaerobic, as well as aerobic, culture.
Because intracranial subdural empyemas may contain multiple organisms,
provisional antibiotic therapy of intracranial subdural empyema, where the
organism is unknown, should be directed against S. aureus, microaerophilic and
anaerobic streptococci, and Gram-negative organisms. Antibiotics should include
1) nafcillin, oxacillin, or vancomycin; plus 2) a third generation
cephalosporin; plus 3) metronidazole. Provisional antibiotic therapy of spinal
subdural empyemas should be directed against S. aureus and streptococci, and
should include nafcillin, oxacillin, or vancomycin. Morbidity and mortality in
intracranial and spinal subdural empyema relate directly to the delay in
institution of therapy. Both conditions should, thus, be treated with great
urgency. Subdural empyema is a rare complication of sinusitis in children. Its clinical
presentation represents a neurosurgical emergency and as a scarcely recognized
entity a delayed diagnosis rapidly increases its fatal prognosis. We report the
clinical and radiological course of an adolescent with a subdural empyema
secondary to sinusitis. Clinical and radiological features, laboratory findings
and outcome of this condition are discussed based in a review of previously
reported cases. OBJECTIVE: Sinusitis is a rare cause of intracranial infection in children.
While intracranial complications of sinusitis are rare, the morbidity and
mortality remain high. Subdural empyema is recognized as the most common
sinogenic intracranial complication. We undertook a review of our cases of
subdural empyema and other intracranial complications of sinusitis over the past
8 years at a busy inner city hospital. Our intent was to identify factors that
may predispose children to these serious complications.
METHODS: A retrospective chart review was conducted using ICD-9 codes to
identify pediatric patients treated for complications of sinusitis at University
Hospital (UH) from 1996 to 2004. Only patients age 18 or younger at the time of
admission were included in this study. The following data were collected from
hospital medical records: age, gender, past medical and social history,
presenting symptoms, history of present illness, microbiology, surgical and
medical intervention, and outcome.
RESULTS: Twelve patients were identified that fit the criteria for this study.
The mean age of these patients was 14.1 years, and 10 of our 12 patients were
male (83.3%). The most common presenting complaints were fever, headache,
altered mental status, orbital cellulitis, nasal symptoms, nausea and vomiting,
and photophobia. In the week prior to admission for intracranial complications,
nine patients were seen by a physician: five patients were seen in the ER and
four by a primary care physician. Subdural empyema was the most commonly
observed intracranial complication in this series. Microaerophilic and anaerobic
organisms were most commonly identified in this series. Most sinus procedures
consisted of endoscopic ethmoid and maxillary sinus drainage. There was a
long-term morbidity rate of 16% and a mortality rate of 8%.
CONCLUSIONS: Three conclusions may be drawn from this study. First, the
morbidity and mortality of intracranial complications of sinusitis remain high
in the pediatric inner-city population despite adequate access to medical care.
Second, subdural empyema appears to arise in the setting of subacute rather than
acute frontal sinusitis. Lastly, there may be an under-diagnosis and delay in
treatment of patients with frontal sinusitis, resulting in subsequent
intracranial complications. Suppurative intracranial infection, including meningitis, intracranial abscess,
subdural empyema, epidural abscess, cavernous sinus thrombosis, and thrombosis
of other dural sinuses, are uncommon sequelae of paranasal sinusitis. A high
index of suspicion is necessary to identify these serious complications. We
present a patient with subdural empyema in whom the diagnosis was delayed,
followed by a discussion of suppurative complications of sinusitis. The case
shows the rapid progression of subdural empyema, which represents a true
neurosurgical emergency requiring prompt diagnosis and management. Intracranial complications of pediatric sinusitis are rare but potentially life
threatening. These complications include cavernous sinus thrombosis, orbital
infection, meningitis, and subdural empyema. Children with these complications
may experience significant morbidity from their infection. In such cases, delay
in diagnosis and treatment may lead to severe brain damage or death. Emergency
physicians, pediatricians, and otolaryngologists should maintain a high index of
suspicion for this complication of disease when treating patients with sinusitis
in the emergency department or outpatient clinic. Early and accurate diagnosis
of subdural empyema will lead to prompt treatment and a favorable outcome for
the patient. We report a case of subdural empyema secondary to frontal sinusitis
in an otherwise healthy immunocompetent adolescent boy. INTRODUCTION: We present the first case of a subdural empyema caused by
Streptococcus pluranimalium, in a healthy adolescent male as a possible
complication of subclinical frontal sinusitis. Clinical features, diagnostic
approach and management of subdural empyema are discussed.
PRESENTATION OF CASE: A 17-year-old male with a 2 day history of headache and
nausea was referred to our Emergency Department (ED) as a case of possible
meningitis. He was afebrile, lethargic and drowsy with significant neck
stiffness on examination. Computerized tomography (CT) revealed a large
frontotemporoparietal subdural fluid collection with significant midline shift.
Subsequent contrast-enhanced CT established the presence of intracranial
empyema; the patient underwent immediate burr-hole evacuation of the pus and
received 7 weeks of intravenous antibiotics, recovering with no residual
neurological deficit.
DISCUSSION: The diagnosis of subdural empyema as a complication of asymptomatic
sinusitis in an immunocompetent patient with no history of fever or upper
respiratory symptoms was uticipated. Furthermore, the organism Streptococcus
pluranimalium that was cultured from the pus has only been documented twice
previously in medical literature to cause infection in humans, as it is
primarily a pathogen responsible for infection in bovine and avian species.
CONCLUSION: Subdural empyema represents a neurosurgical emergency and if left
untreated is invariably fatal. Rapid diagnosis, surgical intervention and
intensive antibiotic therapy improve both morbidity and mortality. Intracranial complications of paranasal sinusitis have become rare due to the
use of antibiotics nowadays. However, several cases have been reported due the
ability of paranasal sinusitis to cause serious complications. Once the
infection spreads over the cranial structure, it could infect the orbits,
underlying bones, meninges, adjacent veins, and brain. Subdural empyema is a
rare but potentially life-threatening complication following paranasal sinusitis
and should be considered as a neurological emergency. The location where
subdural empyema may appear is a challenge in diagnosis and treatment. We report
the case of a 17-year-old boy who presented in a state of somnolence due to
interhemispheric and infratentorial subdural empyema with preseptal cellulitis
secondary to pansinusitis. Early diagnosis and aggressive antibiotic treatment
combined with neurosurgical operation were mandatorily implemented. The case was
managed using a multidisciplinary approach including the ENT, eye, and nutrition
departments. The boy achieved clinical improvement, with impairment of eye
movement as the only persistent symptom before discharge. Daily supervision at
the primary health care center with continuous antibiotic treatment was
recommended to the patient. Pertinent literature with controversies in the
management of subdural empyema will be briefly discussed in this case report. PURPOSE OF REVIEW: Acute and chronic sinusitis can give rise to a wide array of
intracranial and orbital complications. These complications include brain
abscess, subdural empyema, epidural abscess, meningitis, venous sinus
thrombosis, frontal bone osteomyelitis, and orbital cellulitis and abscess.
Despite numerous medical advances, these complications carry a risk of mortality
and significant morbidity.
RECENT FINDINGS: Recent studies have shown improvement in both the mortality and
the morbidity associated with the neurologic complications of acute and chronic
sinusitis. However, there are still a large portion of patients with long-term
sequelae, and the literature reports a morbidity rate of approximately 30%. The
most common post-treatment morbidities include permanent changes in vision,
seizures, and hemiparesis. Although the overall incidence of neurologic
complications from a sinogenic source are rare, the potential long-term
complications can be devastating making prompt diagnosis and treatment vital to
improving outcomes. A 49-year-old male was brought to the Emergency Department after being found
unresponsive. The patient had multiple seizures and was intubated in the
prehospital setting. A computed tomography scan showed bilateral paranasal sinus
disease, and magnetic resoce imaging showed a right frontal abscess and
subdural empyema. Neurosurgery took the patient to the operating room, performed
a craniotomy, and drained a large amount of purulent fluid. He was subsequently
discharged for acute rehabilitation. Clinicians should consider complicated
frontal sinusitis, especially in the undifferentiated patient presenting with
neurologic deficits and signs or symptoms of sinus disease. |
What is aphasia? | Aphasia is an inability to comprehend or formulate language because of damage to specific brain regions. | |
Anaplasma phagocytophilum is an obligate gram-negative, intracellular bacterium, yes or no | Anaplasma phagocytophilum is an obligate gram-negative, intracellular bacterium and causes anaplasmosis | The genus Anaplasma belonging to the Anaplasmataceae family (order
Rickettsiales) comprises obligate intracellular Gram-negative bacteria of
veterinary and public health importance. Six species and five types of strains
genetically related are currently assigned to the genus Anaplasma including
Anaplasma marginale, A. centrale, A. bovis, A. phagocytophilum, A. ovis and A.
platys as classified species, and "A. capra", A. odocolei sp. nov., A.
phagocytophilum-like 1 (Anaplasma sp.-Japan), A. phagocytophilum-like 2
(Anaplasma sp.-China) and A. platys-like (also named Candidatus Anaplasma
camelii) as unclassified strains. Most of these Anaplasma species and strains
have been molecularly identified in several animal and/or tick species in the
north of Africa. The aim of this review is to summarize the current knowledge
about molecular epidemiology, associated risk factors and genetic diversity of
Anaplasma species and related strains infecting animals and/or their
incriminated tick vectors in North Africa. All these data should be considered
when establishing of common management and control programs for anaplasmosis
infecting humans and different animal species in North African countries. Human granulocytic anaplasmosis (HGA), an increasingly recognized febrile
tick-borne illness, is caused by a gram-negative obligate intracellular
bacterium Anaplasma phagocytophilum. Because of nonspecific clinical
manifestations, diagnosis of HGA highly depends on laboratory tests.
Identification of immunoreactive proteins is prerequisite for development of
specific and sensitive immunoassays for HGA. In this study, we identified novel
immunoreactive proteins of A. phagocytophilum. Previous studies indicated that
secreted proteins of A. phagocytophilum and other bacteria can be immunoreactive
antigens. Here we in silico screened A. phagocytophilum genome for encoding
proteins which bear features of type IV secretion system substrates. Among
seventy seven predicted proteins, fourteen proteins were determined for
antigenicity and nine proteins were showed to be immunoreactive antigens. In
addition, an APH1384 peptide harboring a B cell epitope predicted by
bioinformatics was found specifically reacting with anti-A. phagocytophilum
sera. Hereby, we identified novel immunoreactive proteins and delineated a
specific epitope of A. phagocytophilum, which might be employed for HGA
diagnosis. |
What is the role of Acyl-Homoserine Lactone in bacteria? | A number of bacteria use a class of chemical compounds called acyl-homoserine lactones (AHLs) as quorum sensing (QS) signals to coordinate their behavior at the population level, including pathogens like Pseudomonas aeruginosa. | Diverse Gram-negative bacteria communicate with each other by using diffusible
N-acyl-homoserine lactone (AHL) signaling molecules to coordinate gene
expression with cell population density. This mechanism termed 'quorum sensing'
is involved in the regulation of physiological functions as well as multiple
virulence determits. It becomes more and more evident, that bacteria
communicate not only with each other but also with their host. Up to now, little
is known about this interkingdom communication. The AHL quorum sensing molecule
N-3-(oxododecanoyl)-L-homoserine lactone (OdDHL) from Pseudomonas aeruginosa has
been shown to influence the immune system of the host. The role and potential
influence of other AHL molecules from other bacteria have so far not been
determined. In this paper, we investigated the role of 7 different AHLs on
apoptosis of human Jurkat T lymphocytes. We found, that among all homoserine
lactones tested, only OdDHL rapidly induced apoptosis which was accompanied by
the breakdown of the mitochondrial transmembrane potential (DeltaPsi(m)). Since
overexpression of anti-apoptotic Bcl-2 completely abrogated the apoptotic
effect, we presume that OdDHL induces apoptosis by activation of the intrinsic
mitochondrial apoptosis pathway. The reason that bacteria induce apoptosis is
largely unknown. We suspect that through apoptosis an anti-inflammatory response
is triggered. The genomes of many bacteria that participate in nitrogen cycling through the
process of nitrification contain putative genes associated with acyl-homoserine
lactone (AHL) quorum sensing (QS). AHL QS or bacterial cell-cell signaling is a
method of bacterial communication and gene regulation and may be involved in
nitrogen oxide fluxes or other important phenotypes in nitrifying bacteria.
Here, we carried out a broad survey of AHL production in nitrifying bacteria in
three steps. First, we analyzed the evolutionary history of AHL synthase and AHL
receptor homologs in sequenced genomes and metagenomes of nitrifying bacteria to
identify AHL synthase homologs in ammonia-oxidizing bacteria (AOB) of the genus
Nitrosospira and nitrite-oxidizing bacteria (NOB) of the genera Nitrococcus,
Nitrobacter, and Nitrospira Next, we screened cultures of both AOB and NOB with
uncharacterized AHL synthase genes and AHL synthase-negative nitrifiers by a
bioassay. Our results suggest that an AHL synthase gene is required for, but
does not guarantee, cell density-dependent AHL production under the conditions
tested. Finally, we utilized mass spectrometry to identify the AHLs produced by
the AOB Nitrosospira multiformis and Nitrosospira briensis and the NOB
Nitrobacter vulgaris and Nitrospira moscoviensis as N-decanoyl-l-homoserine
lactone (C10-HSL), N-3-hydroxy-tetradecanoyl-l-homoserine lactone
(3-OH-C14-HSL), a monounsaturated AHL (C10:1-HSL), and N-octanoyl-l-homoserine
lactone (C8-HSL), respectively. Our survey expands the list of AHL-producing
nitrifiers to include a representative of Nitrospira lineage II and suggests
that AHL production is widespread in nitrifying bacteria.IMPORTANCE
Nitrification, the aerobic oxidation of ammonia to nitrate via nitrite by
nitrifying microorganisms, plays an important role in environmental nitrogen
cycling from agricultural fertilization to wastewater treatment. The genomes of
many nitrifying bacteria contain genes associated with bacterial cell-cell
signaling or quorum sensing (QS). QS is a method of bacterial communication and
gene regulation that is well studied in bacterial pathogens, but less is known
about QS in environmental systems. Our previous work suggested that QS might be
involved in the regulation of nitrogen oxide gas production during nitrite
metabolism. This study characterized putative QS signals produced by different
genera and species of nitrifiers. Our work lays the foundation for future
experiments investigating communication between nitrifying bacteria, the purpose
of QS in these microorganisms, and the manipulation of QS during nitrification. A number of bacteria use a class of chemical compounds called acyl-homoserine
lactones (AHLs) as quorum sensing (QS) signals to coordinate their behavior at
the population level, including pathogens like Pseudomonas aeruginosa. Blocking
QS using antibodies is an attractive strategy for infection control as this
process takes a central role in P. aeruginosa infections. Here the methods
involved in the generation of high sensitivity anti-QS monoclonal antibodies
from an immunized sheep phage display antibody library are described. A panel of
AHL compounds conjugated to carrier proteins are used for sheep immunization and
a phage display antibody library is constructed using the immune repertoire of
sheep as a source of antibody genes. High sensitivity single chain antibody
fragments (scFv) are isolated from the library using "smart selection
strategies" and reformatted into single chain antibodies (scAbs). The resultant
monoclonal antibodies: (1) recognize HSL compounds at low omolar
concentrations; (2) have the potential to reduce virulence gene expression in P.
aeruginosa; and (3) offer protection in a nematode model of infection. The present work combines molecular docking calculations, 3D-QSAR, molecular
dynamics simulations and free binding energy calculations (MM/PBSA and MM/GBSA)
in a set of 28 structural analogues of acyl homoserine lactones with Quorum
Sensing antagonist activity. The aim of this work is to understand how ligand
binds and is affected by the molecular microenvironment in the active site of
the LasR receptor for pseudomonas aeruginosa. We also study the stability of the
interaction to find key structural characteristics that explain the antagonist
activities of this set of ligands. This information is relevant for the rational
modification or design of molecules and their identification as powerful LasR
modulators. The analysis of molecular docking simulations shows that the 28
analogues have a similar binding mode compared to the native ligand. The
carbonyl groups belonging to the lactone ring and the amide group of the acyl
chain are oriented towards the amino acids forming hydrogen bond like
interactions. The difference in antagonist activity is due to location and
orientation of the LasR side chains within the hydrophobic pocket in its binding
site. Additionally, we carried out molecular dynamics simulations to understand
the conformational changes in the ligand-receptor interaction and the stability
of each complex. Results show a direct relationship among the interaction
energies of the ligands and the activities as an antagonist of the LasR
receptor. |
List 3 indications for rituximab. | Rituximab is used to treat rheumatoid arthritis as well as poly- and dermatomyositis, chronic lymphocytic leukemia, juvenile idiopathic arthritis, and Pemphigus foliaceus (PF). | BACKGROUND: Rituximab is a chimeric, anti-CD20 monoclonal antibody registered
for the treatment of B-cell maligcies and refractory rheumatoid arthritis in
Australia. In addition to these approved indications, there has been growing
interest in the use of off-label rituximab in the management of a variety of
diseases.
AIMS: To determine the current usage of off-label rituximab in Australia, we
collected nationwide data.
METHODS: Information regarding patients receiving rituximab for off-label
indications was prospectively collected for a 6-month period from Australian
public hospitals. Data recorded included clinical indication, dosing schedule,
previous therapy and efficacy assessment. The level of evidence for the use of
rituximab was determined for each off-label indication.
RESULTS: During the 6-month period, a total of 364 instances of off-label
rituximab use was recorded in the national database. A total of 63 underlying
diagnoses was identified. These were subclassified into haematological disorders
(19%), autoimmune connective tissue diseases (12%), vasculitis (12%),
neurological disorders (12%), transplant-related uses (12%), haematological
maligcies (11%), muscle disorders (8%), renal diseases (6%), dermatological
conditions (5%), other conditions (2%) and ocular diseases (1%). Forty percent
of these requests were supported only by level 4 evidence of benefit. Data
highlighted the non-standardised approaches to drug approval mechanisms, dosing
schedules and monitoring for efficacy.
CONCLUSIONS: Off-label rituximab is prescribed for a diverse range of clinical
conditions. Determining a safe and effective means of regulating this use within
an evidence-based framework remains an ongoing challenge. Rituximab is an anti-CD20 monoclonal antibody with considerable potential in
dermatology due to an increase in off-label indications. Chronic
graft-versus-host disease and pemphigus vulgaris are two of the most promising
indications for off-label use of rituximab. It is a generally safe alternative
that should be considered when traditional therapy with corticosteroids or
immunosuppressants has failed or caused significant intolerance. Currently,
rituximab is only FDA-approved for treatment of follicular and diffuse large
B-cell non-Hodgkin's lymphoma, rheumatoid arthritis, chronic lymphocytic
leukemia, granulomatosis with polyangiitis (formerly Wegener's granulomatosis)
and microscopic polyangiitis. Herein, off-label uses of rituximab and its
efficacy in the treatment of cutaneous diseases are reviewed. A number of new treatment options have recently emerged for chronic lymphocytic
leukemia (CLL) patients, including the Bruton's tyrosine kinase (BTK) inhibitor
ibrutinib, phosphatidylinositol-3-kinase (PI3K) delta isoform inhibitor
idelalisib combined with rituximab, the Bcl-2 antagonist venetoclax, and the new
anti-CD20 antibodies obinutuzumab and ofatumumab. Most of these agents are
already included into treatment algorithms defined by international practice
guidelines, but more clinical investigations are needed to answer still
remaining questions. Ibrutinib was proven as a primary choice for patients with
the TP53 gene deletion/mutation, who otherwise have no active treatment
available. Idelalisib with rituximab is also an active therapy, but due to
increased risk of serious infections, its use in first-line treatment is limited
to patients for whom ibrutinib is not an option. A new indication for ibrutinib
was recently approved for older patients with comorbidities, as an alternative
to the already existing indication for chlorambucil with obinutuzumab. The use
of kinase inhibitors is already well established in recurrent/refractory
disease. Immunochemotherapy with fludarabine, cyclophosphamide, rituximab (FCR)
remains a major first-line option for many CLL patients without the TP53 gene
deletion/mutation, and who have no significant comorbidities or history of
infections, and is particularly effective in patients with favorable features
including mutated IGHV status. There are a number of issues regarding novel
therapies for CLL that need further investigation such as optimum duration of
treatment with kinase inhibitors, appropriate sequencing of novel agents,
mechanisms of resistance to inhibitors and response to class switching after
treatment failure, along with the potential role of combinations of targeted
agents. BackgroundPemphigus foliaceus (PF) is a blistering disorder most commonly
presenting in middle age. As PF is restricted to the superficial epidermis, it
is considered more benign than other pemphigus diseases. However, progression to
severe disease is not uncommon. Although rituximab's efficacy has been
well-documented in adults with refractory PF, little data is available on its
role in adolescents.PurposeWe describe a patient with juvenile PF treated with
rituximab and review the literature for similar cases.MethodsPubMed was searched
for the terms: antibody, B cells, blistering, CD20, foliaceus, juvenile,
pemphigus, rituximab, immunosuppression. As the first reported case of rituximab
treated pemphigus was in 2001, only cases from 2001 and after were included.
Juvenile PF was defined as disease diagnosis between ages 12-17.ResultsFive
cases have been reported. The indication for rituximab in most cases was
refractory PF unresponsive to systemic glucocorticoids and non-steroidal
adjuvant therapies. All cases demonstrated significant improvement or complete
remission and most experienced no adverse events.ConclusionsRituximab appears to
be both well tolerated and efficacious for refractory juvenile PF. Therefore, it
may be considered for severe cases of PF to avoid side effects associated with
conventional glucocorticoid therapy. OBJECTIVES: Rituximab (RTX) may be a treatment option for children and young
people with JIA, although it is not licensed for this indication. The aim of
this study was to describe RTX use and outcomes among children with JIA.
METHODS: This analysis included all JIA patients within the UK Biologics for
Children with Rheumatic Diseases study starting RTX. Disease activity was
assessed at RTX start and at follow-up. The total number of courses each patient
received was assessed. Serious infections and infusion reactions occurring
following RTX were reported.
RESULTS: Forty-one JIA patients starting RTX were included, the majority with
polyarthritis: polyarthritis RF negative [n = 14 (35%)], polyarthritis RF
positive [n = 13 (33%)] and extended oligoarthritis [n = 9 (23%)]. Most were
female (80%) with a median age of 15 years [interquartile range (IQR) 12-16] and
a median disease duration of 9 years (IQR 5-11). The median improvement in the
clinical Juvenile Arthritis Disease Activity Score (cJADAS; three-variable
71-joint JADAS) from RTX start was 9 units (n = 7; IQR -14-2). More than half
reported more than one course of RTX. The median time between each course was
219 days (IQR 198-315). During follow-up, 17 (41%) patients reported switching
to another biologic, including tocilizumab (n = 8), abatacept (n = 6) and TNF
inhibitor (n = 3). Three patients (7%) reported a serious infection on RTX (rate
of first serious infection 6.2/100 person-years). Four patients (10%) reported
an infusion reaction.
CONCLUSIONS: This real-world cohort of children with JIA, the majority with
polyarticular or extended oligoarticular JIA, showed RTX may be an effective
treatment option for children who do not respond to TNF inhibitor, with a low
rate of serious infections on treatment. |
Is the crystal structure of Pim-1 available? | Yes,
The crystal structures of Pim1 in apo form and bound with AMPPNP have been solved | Pim1, a serine/threonine kinase, is involved in several biological functions
including cell survival, proliferation, and differentiation. While pim1 has been
shown to be involved in several hematopoietic cancers, it was also recently
identified as a target of aberrant somatic hypermutation in diffuse large cell
lymphoma (DLCL), the most common form of non-Hodgkin's lymphoma. The crystal
structures of Pim1 in apo form and bound with AMPPNP have been solved and
several unique features of Pim1 were identified, including the presence of an
extra beta-hairpin in the N-terminal lobe and an unusual conformation of the
hinge connecting the two lobes of the enzyme. While the apo Pim1 structure is
nearly identical with that reported recently, the structure of AMPPNP bound to
Pim1 is significantly different. Pim1 is unique among protein kinases due to the
presence of a proline residue at position 123 that precludes the formation of
the canonical second hydrogen bond between the hinge backbone and the adenine
moiety of ATP. One crystal structure reported here shows that changing P123 to
methionine, a common residue that offers the backbone hydrogen bond to ATP, does
not restore the ATP binding pocket of Pim1 to that of a typical kinase. These
unique structural features in Pim1 result in novel binding modes of AMP and a
known kinase inhibitor scaffold, as shown by co-crystallography. In addition,
the kinase activities of five Pim1 mutants identified in DLCL patients have been
determined. In each case, the observed effects on kinase activity are consistent
with the predicted consequences of the mutation on the Pim1 structure. Finally,
70 co-crystal structures of low molecular mass, low-affinity compounds with Pim1
have been solved in order to identify novel chemical classes as potential Pim1
inhibitors. Based on the structural information, opportunities for optimization
of one specific example are discussed. We have studied the subtleties of fragment docking and binding using data
generated in a Pim-1 kinase inhibitor program. Crystallographic and docking data
analyses have been undertaken using inhibitor complexes derived from an in-house
surface plasmon resoce (SPR) fragment screen, a virtual needle screen, and a
de novo designed fragment inhibitor hybrid. These investigations highlight that
fragments that do not fill their binding pocket can exhibit promiscuous
hydrophobic interactions due to the lack of steric constraints imposed on them
by the boundaries of said pocket. As a result, docking modes that disagree with
an observed crystal structure but maintain key crystallographically observed
hydrogen bonds still have potential value in ligand design and optimization.
This observation runs counter to the lore in fragment-based drug design that all
fragment elaboration must be based on the parent crystal structure alone. Human Pim1 kinase is a serine/threonine protein kinase that plays important
biological roles in cell survival, apoptosis, proliferation, and
differentiation. Moreover, Pim1 is up-regulated in various hematopoietic
maligcies and solid tumors. Thus, Pim1 is an attractive target for cancer
therapeutics, and there has been growing interest in developing small molecule
inhibitors for Pim1. Here, we describe the crystal structure of Pim1 in complex
with a newly developed pyrido[4,3-d]pyrimidine-derivative inhibitor (SKI-O-068).
Our inhibitor exhibits a half maximum inhibitory concentration (IC50) of 123
(±14) nM and has an unusual binding mode in complex with Pim1 kinase. The
interactions between SKI-O-068 and the Pim1 active site pocket residue are
different from those of other scaffold inhibitor-bound structures. The binding
mode analysis suggests that the SKI-O-068 inhibitor can be improved by
introducing functional groups that facilitate direct interaction with Lys67,
which aid in the design of an optimized inhibitor. PIM kinases are implicated in variety of cancers by promoting cell survival and
proliferation and are targets of interest for therapeutic intervention. We have
identified a low-omolar pan-PIM inhibitor (PIM1/2/3 potency 5:14:2nM) using
structure based modeling. The crystal structure of this compound with PIM1
confirmed the predicted binding mode and protein-ligand interactions except
those in the acidic ribose pocket. We show the SAR suggesting the importance of
having a hydrogen bond donor in this pocket for inhibiting PIM2; however, this
interaction is not important for inhibiting PIM1 or PIM3. In addition, we report
the discovery of a new class of PIM inhibitors by using computational de novo
design tool implemented in MOE software (Chemical Computing Group). These
inhibitors have a different interaction profile. Sustained vascular smooth muscle hypercontractility promotes hypertension and
cardiovascular disease. The etiology of hypercontractility is not completely
understood. New therapeutic targets remain vitally important for drug discovery.
Here we report that Pim kinases, in combination with DAPK3, regulate
contractility and control hypertension. Using a co-crystal structure of lead
molecule (HS38) in complex with DAPK3, a dual Pim/DAPK3 inhibitor (HS56) and
selective DAPK3 inhibitors (HS94 and HS148) were developed to provide
mechanistic insight into the polypharmacology of hypertension. In vitro and
ex vivo studies indicated that Pim kinases directly phosphorylate smooth muscle
targets and that Pim/DAPK3 inhibition, unlike selective DAPK3 inhibition,
significantly reduces contractility. In vivo, HS56 decreased blood pressure in
spontaneously hypertensive mice in a dose-dependent manner without affecting
heart rate. These findings suggest including Pim kinase inhibition within a
multi-target engagement strategy for hypertension management. HS56 represents a
significant step in the development of molecularly targeted antihypertensive
medications. |
Do tumour-associated macrophages have a prognostic role in gliomas? | M2-like TAMs hold an unfavourable prognostic value in high-grade gliomas and may contribute to a pro-tumourigenic microenvironment. | AIMS: Glioblastomas are highly aggressive and treatment resistant. Increasing
evidence suggests that tumour-associated macrophages/microglia (TAMs) facilitate
tumour progression by acquiring a M2-like phenotype. Our objective was to
investigate the prognostic value of TAMs in gliomas using automated quantitative
double immunofluorescence.
METHODS: Samples from 240 patients with primary glioma were stained with
antibodies against ionized calcium-binding adaptor molecule-1 (IBA-1) and
cluster of differentiation 204 (CD204) to detect TAMs and M2-like TAMs. The
expression levels were quantified by software-based classifiers. The
associations between TAMs, gemistocytic cells and glioblastoma subtype were
examined with immuno- and haematoxylin-eosin stainings. Three tissue arrays
containing glioblastoma specimens were included to study IBA-1/CD204 levels in
central tumour and tumour periphery and to characterize CD204+ cells.
RESULTS: Our data revealed that the amount of especially CD204+ TAMs increases
with maligcy grade. In grade III-IV, high CD204 expression was associated
with shorter survival, while high IBA-1 intensity correlated with a longer
survival. In grade IV, CD204 showed independent prognostic value when adjusting
for clinical data and the methylation status of O6-methylguanine-DNA
methyltransferase. Our findings were confirmed in two bioinformatics databases.
TAMs were more abundant in central tumour tissue, mesenchymal glioblastomas and
gliomas with many gemistocytic cells. CD204+ TAMs co-expressed proteins related
to tumour aggressiveness including matrix metallopeptidase-14 and
hypoxia-inducible factor-1α.
CONCLUSIONS: This is the first study to use automated quantitative
immunofluorescence to determine the prognostic impact of TAMs. Our results
suggest that M2-like TAMs hold an unfavourable prognostic value in high-grade
gliomas and may contribute to a pro-tumourigenic microenvironment. |
Is TNF-α an activator of pancreatic stellate cells? | Yes,
TNF-α is the prime factor responsible for the activation of pancreatic stellate cells. | |
Can mitochondria transfer from cell to cell? | Yes,
the recently discovered phenomenon of mitochondrial transfer between mammalian cells has gained momentum since it was first described in cell culture systems more than a decade ago. | Interest in the recently discovered phenomenon of mitochondrial transfer between
mammalian cells has gained momentum since it was first described in cell culture
systems more than a decade ago. Mitochondria-targeting fluorescent dyes have
been repurposed and are now widely used in these studies and in acute disease
models, sometimes without due consideration of their limitations, while vectors
containing mitochondrially-imported fluorescent proteins have complemented the
use of mitochondria-targeting dyes. Genetic approaches that use mitochondrial
DNA polymorphisms have also been used in some in vitro studies and in tumor
models and are particularly useful where mtDNA is damaged or deleted. These
approaches can also be used to study the long-term consequences of mitochondrial
transfer such as in bone marrow and organ transplantation and in tumour biology
where inherent mitochondrial damage is often a key feature. As research on
intercellular mitochondrial transfer moves from cell culture into animal models
and human diseases it will be important to understand the limitations of the
various techniques in order to apply appropriate methodologies to address
physiological and pathophysiological conditions. |
Can Enlimomab improve stroke outcomes? | No. Anti-ICAM therapy with enlimomab is not an effective treatment for ischemic stroke and, indeed, may significantly worsen stroke outcome. | A growing body of evidence, primarily from animal models of cerebral ischemia
and preliminary human studies, indicates that inflammatory mechanisms contribute
to secondary neuronal injury after acute cerebral ischemia. Ischemia followed by
reperfusion rapidly leads to the expression of inflammatory cytokines,
particularly tumor necrosis factor-alpha and interleukin-1beta, which stimulate
a complex cascade of events involving local endothelial cells, neurons,
astrocytes, and perivascular cells. A secondary response includes the release of
other cytokines, an increase in components of the coagulation system, an
upregulation of cell adhesion molecule expression, and changes in the expression
of components of the immune response. The net effect of these events is
transformation of the local endothelium to a prothrombotic/proinflammatory state
and induction of leukocyte migration to the site of injury. A number of studies
have shown that leukocyte migration occurs within hours of reperfusion.
Leukocytes accumulate in the injured region, where they cause tissue injury by
several mechanisms, including occlusion of microvasculature, generation of
oxygen free radicals, release of cytotoxic enzymes, alteration of vasomotor
reactivity, and increase in cytokine and chemoattractant release. Monoclonal
antibodies against leukocyte adhesion molecules have been shown to reduce
infarct volume in animal models of ischemia-reperfusion. However, this treatment
failed to show benefit in the Enlimomab Acute Stroke Trial. A number of factors
may complicate the use of antibody directed adhesion molecule blockade in acute
stroke and will be discussed in this article. Overall, an increased
understanding of inflammatory and immunologic mechanisms still offers great
potential for reducing acute stroke injury. BACKGROUND: There has been recent interest in the possible role of
reperfusion-induced inflammation with neuronal injury after stroke. Enlimomab, a
murine intercellular adhesion molecule-1 (ICAM-1) antibody, reduces leukocyte
adhesion and infarct size in experimental stroke studies. The purpose of the
current clinical trial was to evaluate the use of enlimomab after ischemic
stroke.
METHODS: A total of 625 patients with ischemic stroke were randomized to receive
either enlimomab (n = 317) or placebo (n = 308) within 6 hours of stroke onset.
Treatment was given over 5 days. Patients were evaluated at baseline and on days
5 and 90 after initiation of treatment; long-term assessments were carried out
after 6 and 12 months. The primary efficacy endpoint was the response to therapy
at 90 days on the Modified Rankin Scale; other endpoints included Barthel Index
(BI) and NIH Stroke Scale and survival.
RESULTS: At day 90, the Modified Rankin Scale score was worse in patients
treated with enlimomab than with placebo (p = 0.004). Fewer patients had
symptom-free recovery on enlimomab than placebo (p = 0.004), and more died (22.2
versus 16.2%). The negative effect of enlimomab was apparent on days 5, 30, and
90 of treatment (p = 0.005). There were significantly more adverse events with
enlimomab treatment than placebo, primarily infections and fever. Patients
experiencing fever were more likely to have a poor outcome or die.
CONCLUSIONS: The authors conclude that anti-ICAM therapy with enlimomab is not
an effective treatment for ischemic stroke in the model studied and, indeed, may
significantly worsen stroke outcome. BACKGROUND AND PURPOSE: Enlimomab, a murine monoclonal anti-human intercellular
adhesion molecule (ICAM)-1 antibody, had a negative outcome in a multicenter
acute-stroke trial. We did a bedside-to-bench study in standardized rat stroke
models to explore mechanisms for these untoward results.
METHODS: After focal brain ischemia in Wistar rats and spontaneously
hypertensive rats (SHR), we administered murine anti-rat ICAM-1 antibody (1A29),
subclass-matched murine immunoglobulin (IgG1), or vehicle intravenously. To
examine whether rat anti-mouse antibodies were generated against the mouse
protein and whether these were deleterious, we sensitized Wistar rats with 1A29
or vehicle 7 days before surgery. Infarct volume, tissue myeloperoxidase
activity, neutrophil CD11b expression, and microvascular E-selectin, P-selectin,
and ICAM-1 expression were examined 48 hours after surgery. Complement
activation was serially assessed for 2 hours after a single injection of either
1A29 or vehicle.
RESULTS: 1A29 treatment did not significantly reduce infarct size in either
strain. 1A29 sensitization augmented infarct size and generated rat anti-mouse
antibodies. Although 1A29 inhibited neutrophil trafficking shown by reduction in
brain myeloperoxidase activity, circulating neutrophils were activated and
displayed CD11b upregulation. Complement was activated in 1A29-sensitized Wistar
rats and 1A29-treated SHR. E-selectin (SHR), endothelial P-selectin (Wistar and
SHR), and ICAM-1 (SHR) were upregulated in animals treated with 1A29.
CONCLUSIONS: Administration to rats of a murine antibody preparation against
ICAM-1, 1A29, elicits the production of host antibodies against the protein,
activation of circulating neutrophils, complement activation, and sustained
microvascular activation. These observations provide several possible mechanisms
for central nervous system-related clinical deterioration that occurred when
Enlimomab was given in acute ischemic stroke. An abundance of experimental data show that inflammation contributes to cerebral
ischaemic injury and that attenuation of the inflammatory response can improve
outcome. The two clinical trials of therapy aimed at limiting the inflammatory
response in acute stroke that have been carried out to date, however, have not
shown a benefit to such therapy. The potential reasons for the failure of these
trials are discussed. Animal models of focal ischaemia induced by middle cerebral artery occlusion
(MCAO) provide most evidence for cellular inflammatory responses in stroke.
Permanent MCAO results in a modest neutrophil infiltration at 24 h after
ischaemia, predomitly around arterial vessels at the margins of infarction,
whereas MCAO with subsequent reperfusion is associated with substantial
infiltration by neutrophils throughout the entire infarct. Several studies show
that C-reactive protein (CRP), an inflammatory marker, is associated with stroke
outcomes and future vascular events. Several drugs, especially
hydroxymethylglutaryl coenzyme A reductase inhibitors (statins), have been
demonstrated to reduce hsCRP levels independently of their effects on plasma
cholesterol. Various cytokines were shown to be expressed in the injured brain.
Recent investigations demonstrated that mRNAs of above cytokines were induced in
the ischemic rat brain. TNF-alpha is a pleiotropic cytokine that mediates key
roles in many physiological and pathological cellular processes including acute
and chronic inflammation, programmed cell death or apoptosis, anti-tumor
responses, and infection. Pharmaceutical industry to search a small molecule TNF
inhibitor have taken multiple strategies. Significant protection after in vivo
oral use of SB-239063 from brain injury and neurological deficits was observed
in one study. In the same study significant protection from brain injury and
neurological deficits was also demonstrated due to i.v post-stroke treatment
with the same compound. Leukocyte-endothelial adhesion process consists of
several steps, beginning with rolling of the leukocyte on the endothelial
surface until it has slowed down to such a degree that it sticks to the
endothelium. Treatment with a murine anti-ICAM-1 antibody (enlimomab) has been
investigated in patients with acute ischemic stroke in the Enlimomab Acute
Stroke Trial (EAST). Unfortunately, the case fatality rate in this trial was
significantly higher in the enlimomab patient group than in the placebo group.
Furthermore, experimental data have shown that focal cerebral ischemia induces a
time-dependent activation of granulocytes, lymphocytes, and macrophages.
Dissipation of ATP by CD39 reduced P2X7 receptor stimulation and thereby
suppressed baseline leukocyte alphaMbeta2-integrin expression. As
alphaMbeta2-integrin blockade reversed the postischemic, inflammatory phenotype
of Cd39-/- mice, these data suggest that phosphohydrolytic activity on the
leukocyte surface suppresses cell-cell interactions that would otherwise promote
thrombosis or inflammation. |
What is the Triad of Alport Syndrome? | Alport syndrome is a rare condition characterized by the clinical triad of nephritic syndrome, sensorineural deafness, and ophthalmological alterations. | BACKGROUND: Alport syndrome refers to the clinical triad of hereditary
nephritis, sensorineural deafness, and ocular abnormalities. Ultrastructural
findings in the lens capsule and in the renal glomeruli have provided evidence
that abnormal basement membranes are elaborated in affected tissues of patients
with this disorder. Recently, the results of several linkage studies have
allowed the genetic defect in Alport syndrome to be mapped to a locus that codes
for a subtype of type IV collagen (alpha 5) known to be present in glomerular
basement membranes. In spite of these advances, the nature of the retinal flecks
in Alport syndrome and the visual consequences of the flecks remain
controversial.
METHODS: Detailed psychophysical and electrophysiologic testing was performed in
a young man with Alport syndrome. The concurrence of an unusually extensive
fleck retinopathy and unilateral pseudophakia afforded a unique opportunity to
assess the effect of the flecks on retinal function.
RESULTS: No sensory deficits were present in the eye with clear media.
CONCLUSION: Macular flecks in Alport syndrome are not associated with
demonstrable retinal dysfunction. The authors address questions about the nature
and pathogenesis of the flecks in light of new clinical and genetic information. Alport syndrome is an oculo-renal syndrome characterized by a triad of clinical
findings consisting of hemorrhagic nephritis, sensorineural hearing loss and
characteristic ocular findings. We report a young male patient who presented
with painless diminution of vision associated with hearing loss. The importance
of ophthalmic evaluation for suspecting the disease is highlighted. INTRODUCTION: Collagen type IV related nephropathies are due to the defects in
collagen IV genes COL4A3, COL4A4, or COL4A5 and comprise a spectrum of
phenotypes ranging from Alport Syndrome (AS) to its mild variants, termed as
familial haematuria or thin basement membrane nephropathy. Classical AS is a
progressive renal disease presenting with a triad of progressive hematuric
nephritis and typical extra-renal complications, such as sensorineural hearing
loss (SNHL) and variable ocular anomalies. The mode of inheritance in AS is
X-linked in 85%, autosomal recessive in 15%, and autosomal domit in rare
cases.
OBJECTIVES: This study aims to identify underlying mutation in multiple
individuals from a large consanguineous Saudi family with inherited nephropathy,
including our index patient who manifested all the features of classical AS.
PATIENTS AND METHODS: Patients were diagnosed by nephrologists and clinical
geneticists. All the individuals underwent clinical, audiological and
ophthalmological evaluation. Blood samples were collected after written informed
consent. DNA extraction, homozygosity mapping and PCR amplification followed
standard methodologies.
RESULTS: The disease locus was mapped to 2q36.3, where both COL4A3 and COL4A4
reside. Sanger sequencing of COL4A3 and COL4A4 revealed an underlying novel
homozygous disease-causing COL4A4 mutation (c.2420delG; p.G807fsX60) in the
affected proband. Considerable phenotypic variability segregating with this
COL4A4 mutation in our study family is documented. The homozygous mutants were
manifesting end-stage renal disease (ESRD) in their adolescence, while the
heterozygous carrier members were presenting with considerable phenotypic
heterogeneity ranging from intermittent hematuria to late onset ESRD. In
addition, there is a relatively severe involvement of the ear (SNHL) and eye in
the homozygotes than the heterozygotes. Fertility problems were also noted in
both of the homozygous females.
CONCLUSION: Identification of the causative mutation is an efficient strategy
for conclusive molecular diagnosis in the patients and to establish
genotype/phenotype correlation. It is important to study and evaluate
asymptomatic carriers, to predict prognosis of the disease and to obviate the
need for another renal biopsy in at-risk related family members. While an
accurate genetic diagnosis of AS provides valuable information for genetic
counseling in the extended family members, it can also facilitate future
prenatal diagnosis and planning for pre-implantation genetic diagnosis. BACKGROUND: Alport syndrome is an inherited Type IV collagenopathy characterised
by renal failure, hearing loss and ophthalmic manifestations such as lenticonus
and dot-and-fleck retinopathy. New signs have been described which can be useful
both for diagnosis and for prognosticating the risk of complications. This study
examines and describes a triad comprising the unusual 'stair-case' foveal sign,
together with choroidal thinning and late-stage peripheral schisis in a patient
with Alport syndrome.
CASE PRESENTATION: This is a case report of a 49-year-old Caucasian male with a
background of X-linked Alport syndrome presenting with gradual and progressive
diminution of vision in the left eye with a central blur. He had already
undergone three renal allografts, was deaf and suffered from hypertension by the
time of his first presentation to ophthalmology. On examination, corrected
visual acuity was 6/9.5 in the right eye and 6/30 in the left eye. Optical
coherence tomography imaging showed an unusual 'stair-case' sign of the fovea in
both eyes, together with choroidal thinning. We postulate that an abnormal
vitreomacular interface followed by vitreomacular traction and eventually
separation, removing layers of the inner retina with the vitreous, led to this
unusual appearance. Subsequently, this patient also developed schitic changes
more peripherally in the retina which progressed over the following 5 years.
CONCLUSION: The stair-case foveal sign, choroidal thinning and mid-peripheral
schisis are three signs that clinicians might expect to encounter on optical
coherence tomography imaging of patients with Alport syndrome. These findings
can be attributed to unique mutations of collagen IV which lead to a variety of
clinical phenotypes affecting basement membrane structures. Identification of
these features may not only be useful diagnostically and in forecasting
complications such as macular holes, but also predict mode of inheritance and
likelihood of early-onset renal failure. |
Does GRHL2 over-expression lead to EMT? | Grainyhead-like 2 (Grhl2), a transcription factor, has been reported to be associated with several tumor processes including EMT. Grhl2 antagonizes transforming growth factor-b (TGFb)-induced EMT | Until now the essential transcription factor that determines the epithelial
phenotype of breast cancer has not been identified and its role in
epithelial-to-mesenchymal transition (EMT) and tumor progression remain unclear.
Here, by analyzing large expression profiles of human breast cancer cells, we
found an extraordinary correlation between the expression of Grainyhead
transcription factor Grhl2 and epithelial marker E-cadherin. Knockdown of Grhl2
expression by shRNA in human mammary epithelial cell MCF10A leads to
down-regulation of E-cadherin and EMT. Grhl2 is down-regulated in disseminated
cancer cells that have undergone EMT, and over-expression of Grhl2 is sufficient
to induce epithelial gene expression. Large clinical datasets reveal that
expression of Grhl2 is significantly associated with poor relapse free survival
and increased risk of metastasis in breast cancer patients. In mouse models,
over-expression of Grhl2 significantly promotes tumor growth and metastasis.
Further testing of several Grhl2 regulated genes leads to the same conclusions
that the tumorigenic and metastatic potentials of tumor cells are linked to
epithelial phenotype but not mesenchymal phenotype. In conclusion, our findings
indicate that Grhl2 plays an essential role in the determination of epithelial
phenotype of breast cancers, EMT and tumor progression. Using a retrovirus-mediated cDNA expression cloning approach, we identified the
grainyhead-like 2 (GRHL2) transcription factor as novel protooncogene.
Overexpression of GRHL2 in NIH3T3 cells induced striking morphological changes,
an increase in cell proliferation, anchorage-independent growth, and tumor
growth in vivo. By combining a microarray analysis and a phylogenetic
footprinting analysis with various biochemical assays, we identified the
epidermal growth factor receptor family member Erbb3 as a novel GRHL2 target
gene. In breast cancer cell lines, shRNA-mediated knockdown of GRHL2 expression
or functional inactivation of GRHL2 using domit negative GRHL2 proteins
induces down-regulation of ERBB3 gene expression, a striking reduction in cell
proliferation, and morphological and phenotypical alterations characteristic of
an epithelial-to-mesenchymal transition (EMT), thus implying contradictory roles
of GRHL2 in breast carcinogenesis. Interestingly, we could further demonstrate
that expression of GRHL2 is directly suppressed by the transcription factor zinc
finger enhancer-binding protein 1 (ZEB1), which in turn is a direct target for
repression by GRHL2, suggesting that the EMT transcription factors GRHL2 and
ZEB1 form a double negative regulatory feedback loop in breast cancer cells.
Finally, a comprehensive immunohistochemical analysis of GRHL2 expression in
primary breast cancers showed loss of GRHL2 expression at the invasive front of
primary tumors. A pathophysiological relevance of GRHL2 in breast cancer
metastasis is further demonstrated by our finding of a statistically significant
association between loss of GRHL2 expression in primary breast cancers and lymph
node metastasis. We thus demonstrate a crucial role of GRHL2 in breast
carcinogenesis. The transcription factor grainyhead-like 2 (GRHL2) plays a crucial role in
various developmental processes. Although GRHL2 recently has attracted
considerable interest in that it could be identified as a novel suppressor of
the epithelial-to-mesenchymal transition, evidence is emerging that GRHL2 also
exhibits tumour-promoting activities. Aim of the present study therefore was to
help defining the relevance of GRHL2 for human cancers by performing a
comprehensive immunohistochemical analysis of GRHL2 expression in normal (n =
608) and (n = 3,143) tumour tissues using tissue microarrays. Consistent with
its accepted role in epithelial morphogenesis, GRHL2 expression preferentially
but not exclusively was observed in epithelial cells. Regenerative and
proliferating epithelial cells with stem cell features showed a strong GRHL2
expression. Highly complex GRHL2 expression patterns indicative of both reduced
and elevated GRHL2 expression in tumours, possibly reflecting potential
tumour-suppressing as well as oncogenic functions of GRHL2 in distinct human
tumours, were observed. A dysregulation of GRHL2 expression for the first time
was found in tumours of non-epithelial origin (e.g., astrocytomas, melanomas).
We also report GRHL2 copy number gains which, however, did not necessarily
translate into increased GRHL2 expression levels in cancer cells. Results
obtained by meta-analysis of gene expression microarray data in conjunction with
functional assays demonstrating a direct regulation of HER3 expression further
point to a potential therapeutic relevance of GRHL2 in ovarian cancer.
Hopefully, the results presented in this study may pave the way for a better
understanding of the yet largely unknown function of GRHL2 in the initiation,
progression and also therapy of cancers. Epithelial-mesenchymal transition (EMT), a biological process by which polarized
epithelial cells convert into a mesenchymal phenotype, has been implicated to
contribute to the molecular heterogeneity of epithelial ovarian cancer (EOC).
Here we report that a transcription factor--Grainyhead-like 2 (GRHL2) maintains
the epithelial phenotype. EOC tumours with lower GRHL2 levels are associated
with the Mes/Mesenchymal molecular subtype and a poorer overall survival.
shRNA-mediated knockdown of GRHL2 in EOC cells with an epithelial phenotype
results in EMT changes, with increased cell migration, invasion and motility. By
ChIP-sequencing and gene expression microarray, microRNA-200b/a is identified as
the direct transcriptional target of GRHL2 and regulates the epithelial status
of EOC through ZEB1 and E-cadherin. Our study demonstrates that loss of GRHL2
increases the levels of histone mark H3K27me3 on promoters and GRHL2-binding
sites at miR-200b/a and E-cadherin genes. These findings support GRHL2 as a
pivotal gatekeeper of EMT in EOC via miR-200-ZEB1. Phenotypic plasticity involves a process in which cells transiently acquire
phenotypic traits of another lineage. Two commonly studied types of phenotypic
plasticity are epithelial-mesenchymal transition (EMT) and
mesenchymal-epithelial transition (MET). In carcinomas, EMT drives invasion and
metastatic dissemination, while MET is proposed to play a role in metastatic
colonization. Phenotypic plasticity in sarcomas is not well studied; however,
there is evidence that a subset of sarcomas undergo an MET-like phenomenon.
While the exact mechanisms by which these transitions occur remain largely
unknown, it is likely that some of the same master regulators that drive EMT and
MET in carcinomas also act in sarcomas. In this study, we combined mathematical
models with bench experiments to identify a core regulatory circuit that
controls MET in sarcomas. This circuit comprises the microRNA 200 (miR-200)
family, ZEB1, and GRHL2. Interestingly, combined expression of miR-200s and
GRHL2 further upregulates epithelial genes to induce MET. This effect is
phenocopied by downregulation of either ZEB1 or the ZEB1 cofactor, BRG1. In
addition, an MET gene expression signature is prognostic for improved overall
survival in sarcoma patients. Together, our results suggest that a miR-200,
ZEB1, GRHL2 gene regulatory network may drive sarcoma cells to a more
epithelial-like state and that this likely has prognostic relevance. Metastasis is one of the typical features of maligcy that significantly
increases cancer-related mortality. Recent studies have shown that
epithelial-mesenchymal transition (EMT) is closely related to the invasion and
migration of cancer cells. Grainyhead-like 2 (Grhl2), a transcription factor,
has been reported to be associated with several tumor processes including EMT.
In the previous study, we have reported that Grhl2 functioned as a tumor
suppressor in proliferation and apoptosis of gastric cancer. Here we aim to
explore the effects of Grhl2 on invasion and migration of gastric cancer and
further clarify its possible underlying mechanisms. As a result, in both SGC7901
and MKN45 cells, Grhl2 overexpression significantly inhibited the ability of
invasion and migration. In addition, preliminary experiments showed that Grhl2
reduces the protein expression of matrix metalloproteinase-2, -7 and -9 (MMP-2,
MMP-7 and MMP-9). Most importantly, Grhl2 antagonizes transforming growth
factor-β (TGFβ)-induced EMT, and inhibition of TGFβ signaling pathways can
restore Grhl2 expression. Finally, the results of subcutaneous xenograft model
indicated that Grhl2 suppresses the growth of gastric cancer and reverses EMT
process in vivo. Meanwhile, the metastatic tumor model further confirmed the
inhibition of Grhl2 on metastasis of gastric cancer. Taken together, our
findings proved that Grhl2, functioned as a tumor suppressor, reduces the
invasion and migration through inhibition of TGFβ-induced EMT in gastric cancer. |
What is Intanza? | Intanza(r) 9 ug (sanofi pasteur) is a microneedle-delivered intradermal trivalent inactivated influenza vaccine approved in 2009 for the prevention of seasonal influenza in adults 18 to 59 years of age. The microneedle system reliably and reproducibly delivers the vaccine to the dermis. Clinical studies show that Intanza 9 ug is as immunogenic and as well tolerated in working-age adults as a reference intramuscular trivalent inactivated vaccine. Local reactions to Intanza 9 ug, mainly erythema, are transient, mostly mild or moderate, and do not affect acceptability. Intanza 9 ug is considered satisfactory by at least 95% of both vaccinees and prescribers, especially because of the short needle and rapid administration. | |
Is the Fluzone intradermal and the Fluzone intradermal quadrivalent vaccine produced by different companies? | No, the Fluzone Intradermal vaccine and the Fluzone Intradermal Quadrivalent vaccine are produced by Sanofi Pasteur. | INTRODUCTION: An intradermal version of Fluzone® split-virion inactivated
trivalent influenza vaccine, containing 9 µg hemagglutinin per strain of A/H1N1,
A/H3N2, and one B lineage virus (Fluzone Intradermal, Sanofi Pasteur), became
available in the US during the 2011-2012 influenza season for adults 18-64 years
of age. In advance of the 2015-2016 season, Fluzone Intradermal was replaced
with Fluzone Intradermal Quadrivalent vaccine, which contains 9 µg hemagglutinin
per strain of the two A-strain viruses and both B-strain lineage viruses
(Victoria and Yamagata).
AREAS COVERED: This literature review summarizes the history and mechanism of
intradermal vaccination, discusses the clinical trial results supporting the
immunogenicity and safety of Fluzone Intradermal Quadrivalent vaccine, and
describes the unique microinjection system used to deliver Fluzone Intradermal
Quadrivalent. Expert commentary: Fluzone Intradermal Quadrivalent may boost
confidence in influenza vaccination with the addition of a second B-lineage
strain. By using an innovative microinjection system, the vaccine is also
designed to address some of the logistic challenges faced by healthcare
providers administering immunizations. |
What is the purpose of the Barricaid annular closure device? | Barricaid annular closure device can improve outcome after lumbar discectomy by reducing the risk of recurrent disc herniation of the same level. | Lumbar discectomy is an effective treatment for lumbar disc herniation (LDH).
Although the majority of patients experience successful outcomes, a significant
fraction will experience a recurrence of their back pain due to facet joint
degeneration. Facet joint degeneration after discectomy may be the result of
excessive nuclear removal, disc space narrowing, and annular injury. This study
investigated whether implantation with the Barricaid annular closure device
(ACD) during discectomy reduced the rate of facet degeneration. Inclusion
criteria were primary lumbar disc herniation failing conservative treatment,
Visual Analog Scale (VAS) Leg≥40/100, Oswestry Disability Index (ODI)≥40/100 and
defects that were ≤60 mm2 (Barricaid arm only), and patient age 18-75. CT
interpretations were collected preoperatively and 12 months post-discectomy.
Patients implanted with Barricaid had significantly reduced rates and grades of
facet degeneration than patients without Barricaid. Reinforcing the annulus
fibrosus with Barricaid during lumbar discectomy may slow the progression of
facet joint degeneration. Although lumbar discectomy is an effective treatment for lumbar disc herniation,
complications exist, including postoperative disc height loss, facet joint
degeneration, and recurrent disc herniation. To solve these problems, annular
closure devices have been utilized in other countries, producing satisfactory
results, but there has been no report of annular closure device use in our
country. Here, we demonstrate the preliminary reports of Barricaid® insertion in
3 patients who underwent surgery for lumbar disc herniation. BACKGROUND: Patients with large defects in the annulus fibrosus following lumbar
discectomy have high rates of symptomatic reherniation. The Barricaid annular
closure device provides durable occlusion of the annular defect and has been
shown to significantly lower the risk of symptomatic reherniation in a large
European randomized trial. However, the performance of the Barricaid device in a
United States (US) population has not been previously reported.
DESIGN AND METHODS: This is a historically controlled post-market multicenter
study to determine the safety and efficacy of the Barricaid device when used in
addition to primary lumbar discectomy in a US population. A total of 75 patients
with large annular defects will receive the Barricaid device following lumbar
discectomy at up to 25 sites in the US and will return for clinical and imaging
follow-up at 4 weeks, 3 months, and 1 year. Trial oversight will be provided by
a data safety monitoring board and imaging studies will be read by an
independent imaging core laboratory. Patients treated with the Barricaid device
in a previous European randomized trial with comparable eligibility criteria,
surgical procedures, and outcome measures will serve as historical controls.
Main outcomes will include back pain severity, leg pain severity, Oswestry
Disability Index, health utility on the EuroQol-5 Dimension questionnaire,
complications, symptomatic reherniation, and reoperation. Propensity score
adjustment using inverse probability of treatment weighting will be used to
adjust for differences in baseline patient characteristics between the US trial
participants and European historical controls.
ETHICS AND DISSEMINATION: This study was approved by a central institutional
review board. The study results of this trial will be widely disseminated at
conference proceedings and published in peer-reviewed journals. The outcomes of
this study will have important clinical and economic implications for all
stakeholders involved in treating patients with lumbar discectomy in the US.
STUDY REGISTRATION: ClinicalTrials.gov (https://clinicaltrials.gov):
NCT03986580.
LEVEL OF EVIDENCE: 3. |
What disease is associated with mutations in the MECP2 transcription factor? | mutations in the methyl-cpg-binding protein-2 gene (mecp2) are commonly associated with rett syndrome | Rett syndrome (RTT) is a severe neurodevelopmental disorder with features of
autism that results from mutation of the gene encoding the transcriptional
repressor methyl-CpG binding protein (MECP2). The consequences of loss of a
transcription factor may be complex, affecting the expression of many proteins,
thus limiting understanding of this class of diseases and impeding therapeutic
strategies. This is true for RTT. Neither the cell biological mechanism(s) nor
the developmental stage affected by MECP2 deficiency is known. In vivo analysis
of the olfactory system demonstrates that Mecp2 deficiency leads to a transient
delay in the terminal differentiation of olfactory neurons. This delay in
maturation disrupts axonal targeting in the olfactory bulb, resulting in
abnormal axonal projections, subglomerular disorganization, and a persistent
reduction in glomerular size. These results indicate a critical cell biological
function for Mecp2 in mediating the final stages of neuronal development. Rett syndrome (RTT), the second most common cause of mental retardation in
females, has been associated with mutations in MeCP2, the archetypical member of
the methyl-CpG binding domain (MBD) family of proteins. MeCP2 additionally
possesses a transcriptional repression domain (TRD). We have compared the gene
expression profiles of RTT- and normal female-derived lymphoblastoid cells by
using cDNA microarrays. Clustering analysis allowed the classification of RTT
patients according to the localization of the MeCP2 mutation (MBD or TRD) and
those with clinically diagnosed RTT but without detectable MeCP2 mutations.
Numerous genes were observed to be overexpressed in RTT patients compared with
control samples, including excellent candidate genes for neurodevelopmental
disease. Chromatin immunoprecipitation analysis confirmed that binding of MeCP2
to corresponding promoter CpG islands was lost in RTT-derived cells harboring a
mutation in the region of the MECP2 gene encoding the MBD. Bisulfite genomic
sequencing demonstrated that the majority of MeCP2 binding occurred in DNA
sequences with methylation-associated silencing. Most importantly, the finding
that these genes are also methylated and bound by MeCP2 in neuron-related cells
suggests a role in this neurodevelopmental disease. Our results provide new data
of the underlying mechanisms of RTT and unveil novel targets of MeCP2-mediated
gene repression. Rett syndrome (RTT) is associated with mutations in the transcriptional
repressor gene MeCP2. Although the clinical and neuropathological signs of RTT
suggest disrupted synaptic function, the specific role of methyl-CpG binding
protein 2 (MeCP2) in postmitotic neurons remains relatively unknown. We examined
whether MeCP2 deficiency in central neurons contributes to the neuropathogenesis
in RTT. Primary cerebellar granule neuronal cultures from wild-type (WT) and
MeCP2-/- mice were exposed to N-methyl-d-aspartate (NMDA) and AMPA-induced
excitotoxicity and hypoxic-ischemic insult. The magnitude of cell death in
MeCP2-/- cells after excitotoxicity and hypoxia was greater than in the WT
littermate control cultures and occurred after shorter exposures that usually,
in the WT, would not cause cell death. Pretreatment with the growth factor
fibroblast growth factor 1 (FGF-1) under conditions at which WT cells showed
complete neuroprotection, only partially protected MeCP2-/- cells. To elucidate
specifically the effects of MeCP2 knockout (KO) on cell death, we examined two
death cascade pathways. MeCP2-/- neurons exposed to 6 h of hypoxia exhibited
enhanced activation of the proapoptotic caspase-3 and increased mitochondrial
release of apoptosis inducing factor (AIF) compared with WT neurons, which did
not show significant changes. However, pretreatment with the caspase inhibitor
ZVAD-FMK had little or no effect on AIF release and its subcellular
translocation to the nucleus, suggesting caspase-independent AIF release and
their independent contribution to hypoxia-induced cell death. Reintroduction of
intact MeCP2 gene in MeCP2-/- cells or MeCP2 gene silencing by MeCP2siRNA in WT
cells further confirmed the differential sensitivity of the WT and MeCP2-/-
cells and suggest a direct role of MeCP2 in cell death. These results clearly
demonstrate increased cell death occurred in neurons lacking MeCP2 expression
via both caspase- and AIF-dependent apoptotic mechanisms. Our findings suggest a
novel, yet unknown, role for MeCP2 in central neurons in the control of neuronal
response to cell death. BACKGROUND: Rett syndrome (RTT) is caused by mutations in the transcriptional
repressor methyl CpG-binding protein 2 (MECP2). Brain-derived neurotrophic
factor (BDNF) is a neurotrophic factor playing a major role in neuronal
survival, neurogenesis, and plasticity, and it has been shown that BDNF
expression is regulated by MeCP2 through a complex interaction. A common
polymorphism of BDNF (Val66Met [p.V66M]) has been found to correlate with
severity and course of several neuropsychiatric disorders.
METHODS: We examined the association between disease severity score, assessed by
the modified Percy score, and BDNF polymorphism, using regression methods, in
125 mutation-positive patients with RTT from the Australian Rett Syndrome
Database and an Israeli cohort.
RESULTS: Those who were heterozygous (Val/Met) had slightly more severe disease
than those who were homozygous for the wild-type (Val/Val) BDNF polymorphism
(increased severity score 2.1, p = 0.09). In those with p.R168X, a commonly
occurring MECP2 mutation in RTT, there was a 6-point increase in severity score
for those who were heterozygous for the BDNF polymorphism, both unadjusted (p =
0.02) and adjusted for age (p = 0.03). Individuals with the p.R168X mutation and
heterozygous for the BDNF polymorphism were also at an increased risk of seizure
onset (hazard ratio 5.3, 95% confidence interval 1.6-17.7) compared with those
homozygous for the wild-type BDNF allele.
CONCLUSIONS: In addition to mutation type and degree of X-chromosome skewing,
the common brain-derived neurotrophic factor (BDNF) polymorphism appears to be
another genetic modifier of Rett syndrome (RTT) severity. This suggests that
BDNF function may play a significant role in the pathogenesis of RTT. Rett syndrome is a severe neurodevelopmental disorder mainly caused by mutations
in the transcriptional regulator MeCP2. Although there is no effective therapy
for Rett syndrome, the recently discovered disease reversibility in mice
suggests that there are therapeutic possibilities. Identification of MeCP2
targets or modifiers of the phenotype can facilitate the design of curative
strategies. To identify possible novel MeCP2 interactors, we exploited a
bioinformatic approach and selected Ying Yang 1 (YY1) as an interesting
candidate. We demonstrate that MeCP2 interacts in vitro and in vivo with YY1, a
ubiquitous zinc-finger epigenetic factor regulating the expression of several
genes. We show that MeCP2 cooperates with YY1 in repressing the ANT1 gene
encoding a mitochondrial adenine nucleotide translocase. Importantly, ANT1 mRNA
levels are increased in human and mouse cell lines devoid of MeCP2, in Rett
patient fibroblasts and in the brain of Mecp2-null mice. We further demonstrate
that ANT1 protein levels are upregulated in Mecp2-null mice. Finally, the
identified MeCP2-YY1 interaction, together with the well-known involvement of
YY1 in the regulation of D4Z4-associated genes at 4q35, led us to discover the
anomalous depression of FRG2, a subtelomeric gene of unknown function, in Rett
fibroblasts. Collectively, our data indicate that mutations in MeCP2 might cause
the aberrant overexpression of genes located at a specific locus, thus providing
new candidates for the pathogenesis of Rett syndrome. As both ANT1 mutations and
overexpression have been associated with human diseases, we consider it highly
relevant to address the consequences of ANT1 deregulation in Rett syndrome. Rett syndrome is a neurodevelopmental disorder caused by loss-of-function
mutations in the gene encoding the transcription factor methyl-CpG-binding
protein 2 (MeCP2). One of its targets is the gene encoding brain-derived
neurotrophic factor (bdnf). In vitro studies using cultured neurons have
produced conflicting results with respect to the role of MeCP2 in BDNF
expression. Acute intermittent hypoxia (AIH) induces plasticity in the
respiratory system characterized by long-term facilitation of phrenic nerve
amplitude. This paradigm induces an increase in BDNF protein. We hypothesized
that AIH leads to augmentation of BDNF transcription in respiratory-related
areas of the brainstem and that MeCP2 is necessary for this process. Wild-type
and mecp2 null (mecp2(-/y)) mice were subjected to three 5-min episodes of
exposure to 8% O(2)/4% CO(2)/88% N(2), delivered at 5-min intervals. Normoxia
control wild-type and mecp2 null mice were exposed to room air for the total
length of time, that is, 30 min. Following a recovery in room air, the pons and
medulla were rapidly removed. Expression of BDNF protein and transcripts were
determined by ELISA and quantitative PCR, respectively. AIH induced a
significant increase in BDNF protein in the pons and medulla, and in mRNA
transcript levels in the pons of wild-type animals. In contrast, there were no
significant changes in either BDNF protein or transcripts in the pons or medulla
of mice lacking MeCP2. The results indicate that MeCP2 is required for
regulation of BDNF expression by acute intermittent hypoxia in vivo. Mutations in the gene encoding the methyl-CpG-binding protein MECP2 are the
major cause of Rett syndrome, an autism spectrum disorder mainly affecting young
females. MeCP2 is an abundant chromatin-associated protein, but how and when its
absence begins to alter brain function is still far from clear. Using a stem
cell-based system allowing the synchronous differentiation of neuronal
progenitors, we found that in the absence of MeCP2, the size of neuronal nuclei
fails to increase at normal rates during differentiation. This is accompanied by
a marked decrease in the rate of ribonucleotide incorporation, indicating an
early role of MeCP2 in regulating total gene transcription, not restricted to
selected mRNAs. We also found that the levels of brain-derived neurotrophic
factor (BDNF) were decreased in mutant neurons, while those of the presynaptic
protein synaptophysin increased at similar rates in wild-type and mutant
neurons. By contrast, nuclear size, transcription rates, and BDNF levels
remained unchanged in astrocytes lacking MeCP2. Re-expressing MeCP2 in mutant
neurons rescued the nuclear size phenotype as well as BDNF levels. These results
reveal a new role of MeCP2 in regulating overall RNA synthesis in neurons during
the course of their maturation, in line with recent findings indicating a
reduced nucleolar size in neurons of the developing brain of mice lacking Mecp2. BACKGROUND: Rett syndrome (RTT), a neurodevelopmental disorder that primarily
affects girls, is characterised by a period of apparently normal development
until 6-18 months of age when motor and communication abilities regress. More
than 95% of individuals with RTT have mutations in methyl-CpG-binding protein 2
(MECP2), whose protein product modulates gene transcription. Surprisingly,
although the disorder is caused by mutations in a single gene, disease severity
in affected individuals can be quite variable. To explore the source of this
phenotypic variability, we propose that specific MECP2 mutations lead to
different degrees of disease severity.
METHODS: Using a database of 1052 participants assessed over 4940 unique visits,
the largest cohort of both typical and atypical RTT patients studied to date, we
examined the relationship between MECP2 mutation status and various phenotypic
measures over time.
RESULTS: In general agreement with previous studies, we found that particular
mutations, such as p.Arg133Cys, p.Arg294X, p.Arg306Cys, 3° truncations and other
point mutations, were relatively less severe in both typical and atypical RTT.
In contrast, p.Arg106Trp, p.Arg168X, p.Arg255X, p.Arg270X, splice sites,
deletions, insertions and deletions were significantly more severe. We also
demonstrated that, for most mutation types, clinical severity increases with
age. Furthermore, of the clinical features of RTT, ambulation, hand use and age
at onset of stereotypies are strongly linked to overall disease severity.
CONCLUSIONS: We have confirmed that MECP2 mutation type is a strong predictor of
disease severity. These data also indicate that clinical severity continues to
become progressively worse regardless of initial severity. These findings will
allow clinicians and families to anticipate and prepare better for the needs of
individuals with RTT. Rett syndrome is a monogenic disease due to de novo mutations in either MECP2 or
CDKL5 genes. In spite of their involvement in the same disease, a functional
interaction between the two genes has not been proven. MeCP2 is a
transcriptional regulator; CDKL5 encodes for a kinase protein that might be
involved in the regulation of gene expression. Therefore, we hypothesized that
mutations affecting the two genes may lead to similar phenotypes by
dysregulating the expression of common genes. To test this hypothesis we used
induced pluripotent stem (iPS) cells derived from fibroblasts of one Rett
patient with a MECP2 mutation (p.Arg306Cys) and two patients with mutations in
CDKL5 (p.Gln347Ter and p.Thr288Ile). Expression profiling was performed in
CDKL5-mutated cells and genes of interest were confirmed by real-time RT-PCR in
both CDKL5- and MECP2-mutated cells. The only major change in gene expression
common to MECP2- and CDKL5-mutated cells was for GRID1, encoding for glutamate
D1 receptor (GluD1), a member of the δ-family of ionotropic glutamate receptors.
GluD1 does not form AMPA or NMDA glutamate receptors. It acts like an adhesion
molecule by linking the postsynaptic and presynaptic compartments,
preferentially inducing the inhibitory presynaptic differentiation of cortical
neurons. Our results demonstrate that GRID1 expression is downregulated in both
MECP2- and CDKL5-mutated iPS cells and upregulated in neuronal precursors and
mature neurons. These data provide novel insights into disease pathophysiology
and identify possible new targets for therapeutic treatment of Rett syndrome. Rett syndrome (RTT) is a severe neurodevelopmental disease caused by mutations
in methyl-CpG-binding protein 2 (MECP2), which encodes a transcriptional
modulator of many genes including BDNF. BDNF comprises nine distinct promoter
regions, each triggering the expression of a specific transcript. The role of
this diversity of transcripts remains unknown. MeCP2 being highly expressed in
neurons, RTT was initially considered as a neuronal disease. However, recent
studies have shown that MeCP2 was also expressed in astrocytes. Though several
studies explored Bdnf IV expression in Mecp2-deficient mice, the differential
expression of Bdnf isoforms in Mecp2-deficient neurons and astrocytes was never
studied. By using TaqMan technology and a mouse model expressing a truncated
Mecp2 (Mecp2(308/y)), we firstly showed in neurons that Bdnf transcripts
containing exon I, IIb, IIc, IV, and VI are prominently expressed, whereas in
astrocytes, Bdnf transcript containing exon VI is preferentially expressed,
suggesting a specific regulation of Bdnf expression at the cellular level.
Secondly, we confirmed the repressive role of Mecp2 only on the expression of
Bdnf VI in neurons. Our data suggested that the truncated Mecp2 protein
maintains its function on Bdnf expression regulation in neurons and in
astrocytes. Interestingly, we observed that Bdnf transcripts (I and IXA),
regulated by neural activity induced by bicuculline in Mecp2(308/y) neurons,
were not affected by histone deacetylase inhibition. In contrast, Bdnf
transcripts (IIb, IIc, and VI), regulated by histone deacetylation, were not
affected by bicuculline treatment in wild-type and Mecp2(308/y) neurons. All
these results reflect the complexity of regulation of Bdnf gene. Rett syndrome (RTT) is an X-linked neurodevelopmental disorder due to mutations
affecting the neural transcription factor MeCP2. Approximately 50% of affected
females have decreased bone mass. We studied osteoblast function using a murine
model of RTT. Female heterozygote (HET) and male Mecp2-null mice were compared
to wild type (WT) mice. Micro-CT of tibia from 5 week-old Mecp2-null mice showed
significant alterations in trabecular bone including reductions in bone volume
fraction (-29%), number (-19%), thickness (-9%) and connectivity density (-32%),
and increases in trabecular separation (+28%) compared to WT. We also found
significant reductions in cortical bone thickness (-18%) and in polar moment of
inertia (-45%). In contrast, cortical and trabecular bone from 8 week-old WT and
HET female mice were not significantly different. However, mineral apposition
rate, mineralizing surface and bone formation rate/bone surface were each
decreased in HET and Mecp2-null mice compared to WT mice. Histomorphometric
analysis of femurs showed decreased numbers of osteoblasts but similar numbers
of osteoclasts compared to WT, altered osteoblast morphology and decreased
tissue synthesis of alkaline phosphatase in Mecp2-null and HET mice. Osteoblasts
cultured from Mecp2-null mice, which unlike WT osteoblasts did not express
MeCP2, had increased growth rates, but reductions in mRNA expression of type I
collagen, Runx2 and Osterix compared to WT osteoblasts. These results indicate
that MeCP2 deficiency leads to altered bone growth. Osteoblast dysfunction was
more marked in Mecp2-null male than in HET female mice, suggesting that
expression of MeCP2 plays a critical role in bone development. OBJECTIVES: Methyl-CpG binding protein 2 (MeCP2) is a ubiquitous epigenetic
factor that represses gene expression by modifying chromatin. Mutations in the
MeCP2 gene cause Rett syndrome, a progressive neurodevelopmental disorder.
Recent studies also have shown that MeCP2 plays a role in carcinogenesis.
Specifically, functional ablation of MeCP2 suppresses cell growth and leads to
the proliferation of cancer cells. However, MeCP2's function in adult tissues
remains poorly understood. We utilized a weight matrix-based comparison software
to identify transcription factor binding site (TFBS) of MeCP2-regulated genes,
which were recognized by cDNA microarray analysis.
METHODS: MeCP2 expression was silenced using annealed siRNA in HEK293 cells, and
then a cDNA microarray analysis was performed. Functional analysis was carried
out, and transcriptional levels in target genes regulated by MeCP2 were
investigated. TFBS analysis was done within genes selected by the cDNA
microarray analysis, using a weight matrix-based program and the TRANSFAC 6.0
database.
RESULTS: Among the differentially expressed genes with a change in expression
greater than two-fold, 189 genes were up-regulated and 91 genes were
down-regulated. Genes related to apoptosis and cell proliferation (JUN, FOSL2,
CYR61, SKIL, ATF3, BMABI, BMPR2, RERE, and FALZ) were highly up-regulated. Genes
with anti-apoptotic and anti-proliferative functions (HNRPA0, HIS1, and FOXC1)
were down-regulated. Using TFBS analysis within putative promoters of novel
candidate target genes of MeCP2, disease-related transcription factors were
identified.
CONCLUSIONS: The present results provide insights into the new target genes
regulated by MeCP2 under epigenetic control. This information will be valuable
for further studies aimed at clarifying the pathogenesis of Rett syndrome and
neoplastic diseases. Mutations in MECP2 cause the neurodevelopmental disorder Rett syndrome (RTT).
The RTT missense MECP2R306C mutation prevents MeCP2 from interacting with the
NCoR/histone deacetylase 3 (HDAC3) complex; however, the neuronal function of
HDAC3 is incompletely understood. We found that neuronal deletion of Hdac3 in
mice elicited abnormal locomotor coordination, sociability and cognition.
Transcriptional and chromatin profiling revealed that HDAC3 positively regulated
a subset of genes and was recruited to active gene promoters via MeCP2.
HDAC3-associated promoters were enriched for the FOXO transcription factors, and
FOXO acetylation was elevated in Hdac3 knockout (KO) and Mecp2 KO neurons. Human
RTT-patient-derived MECP2R306C neural progenitor cells had deficits in HDAC3 and
FOXO recruitment and gene expression. Gene editing of MECP2R306C cells to
generate isogenic controls rescued HDAC3-FOXO-mediated impairments in gene
expression. Our data suggest that HDAC3 interaction with MeCP2 positively
regulates a subset of neuronal genes through FOXO deacetylation, and disruption
of HDAC3 contributes to cognitive and social impairment. Mutations in the transcription factor methyl-CpG-binding-protein 2 (MeCP2) cause
a delayed-onset neurodevelopmental disorder known as Rett syndrome (RTT).
Although alteration in serotonin levels have been reported in RTT patients, the
molecular mechanisms underlying these defects are not well understood.
Therefore, we chose to investigate the serotonergic system in hippocampus and
brainstem of male Mecp2-/y knock-out mice in the B6.129P2(C)-Mecp2(tm1.1Bird)
mouse model of RTT. The serotonergic system in mouse is comprised of 16 genes,
whose mRNA expression profile was analyzed by quantitative RT-PCR. Mecp2-/y mice
are an established animal model for RTT displaying most of the cognitive and
physical impairments of human patients and the selected areas receive
significant modulation through serotonin. Using anatomically and functional
characterized areas, we found region-specific differential expression between
wild type and Mecp2-/y mice at post-natal day 40. In brainstem, we found five
genes to be dysregulated, while in hippocampus, two genes were dysregulated. The
one gene dysregulated in both brain regions was dopamine decarboxylase, but of
special interest is the serotonin receptor 5b (5-ht5b), which showed 75-fold
dysregulation in brainstem of Mecp2-/y mice. This dysregulation was not due to
upregulation, but due to failure of down-regulation in Mecp2-/y mice during
development. Detailed analysis of 5-ht5b revealed a receptor that localizes to
endosomes and interacts with Gαi proteins. Mutations in the methyl-CpG-binding protein-2 gene (MECP2) are commonly
associated with Rett syndrome. However, it has long been appreciated that there
exists a spectrum of neuropsychiatric phenotypes associated with MECP2 variants.
The most frequent Rett missense mutations are located in either the
methyl-CpG-binding domain (MBD) or transcription repression domain (TRD).
Clinical roles for mutations in other domains such as the intervening domain
(ID) or AT-Hook domains have yet to be determined. Here, we report functional
analysis of MECP2 missense mutations, located in AT-Hook1 within the ID, in a
large Pakistani family with childhood onset cognitive decline and schizophrenia
(SCZ), de novo in a girl with atypical Rett syndrome, and de novo in a woman
with SCZ. We show that both p.Arg190His and p.Arg190Cys affect the ability of
MeCP2 to bind to AT-rich DNA, also the brain-derived neurotrophic factor (BDNF)
promoter, with the more drastic effects seen for p.Arg190Cys. Both mutations
also affect nuclear chromatin clustering in vitro. These data support a possible
molecular link between MECP2 AT-Hook1 mutations and psychosis. Given the ongoing
large-scale whole exome and whole genome sequencing projects for psychiatric
disorders, our findings suggest that rare missense variants in MECP2 be
carefully evaluated for molecular consequences. |
Is endotrophin derived from collagen? | Yes,
Endotrophin is released from COL VI. | Adipocytes account for the largest proportion among the cells that comprise
breast tissue; therefore, they are considered to be a critical cell type in the
tumor microenvironment of breast cancer. In breast cancer, adipocytes are not
only found adjacent to cancer cells, but they also play an active role in the
entire process of cancer development, progression, metastasis, and treatment
response. Factors including the secretion of adipokines such as leptin and
adiponectin, as well as autotaxin, interleukin 6, tumor necrosis factor alpha,
and hepatic growth factor, metabolic remodeling that supports the growth of
breast cancer by transfer of fatty acids to increase mitochondrial β-oxidation,
extracellular matrix remodeling and endotrophin production from type IV
collagen, and cancer-associated fibroblast phenotype changes have all been
implicated in this comprehensive process. Moreover, adipocytes may act as
obstacles to therapy, as they are involved in mechanisms of resistance against
various breast cancer treatments. Adipose tissues may also be a reservoir for
dormant tumor cells during postsurgical autologous fat grafting. Thus,
adipocytes, and the processes and pathways in which they are involved, could be
effective therapeutic targets for breast cancer. In this review, we focus on the
current understanding of adipocyte biology as it affects breast cancer. Renal fibrosis is the central pathogenic process in progression of chronic
kidney disease (CKD). Collagen type VI (COL VI) is upregulated in renal
fibrosis. Endotrophin is released from COL VI and promotes pleiotropic
pro-fibrotic effects. Kidney disease severity varies considerably and accurate
information regarding CKD progression may improve clinical decisions. We tested
the hypothesis that urinary endotrophin derived during COL VI deposition in
fibrotic human kidneys is a marker for progression of CKD in the Renal
Impairment in Secondary Care (RIISC) cohort, a prospective observational study
of 499 CKD patients. Endotrophin localised to areas of increased COL VI
deposition in fibrotic kidneys but was not present in histologically normal
kidneys. The third and fourth quartiles of urinary endotrophin:creatinine ratio
(ECR) were independently associated with one-year disease progression after
adjustment for traditional risk factors (OR (95%CI) 3.68 (1.06-12.83) and 8.65
(2.46-30.49), respectively). Addition of ECR quartiles to the model for disease
progression increased prediction as seen by an increase in category-free net
reclassification improvement (0.45, 95% CI 0.16-0.74, p = 0.002) and integrated
discrimination improvement (0.04, 95% CI 0.02-0.06, p < 0.001). ECR was
associated with development of end-stage renal disease (ESRD). It is concluded
that ECR predicts disease progression of CKD patients. |
Which receptor is inhibited by bimagrumab? | Bimagrumab is a fully human monoclonal antibody that blocks the activin type II receptors, preventing the activity of myostatin and other negative skeletal muscle regulators. | The myostatin/activin type II receptor (ActRII) pathway has been identified to
be critical in regulating skeletal muscle size. Several other ligands, including
GDF11 and the activins, signal through this pathway, suggesting that the ActRII
receptors are major regulatory nodes in the regulation of muscle mass. We have
developed a novel, human anti-ActRII antibody (bimagrumab, or BYM338) to prevent
binding of ligands to the receptors and thus inhibit downstream signaling.
BYM338 enhances differentiation of primary human skeletal myoblasts and
counteracts the inhibition of differentiation induced by myostatin or activin A.
BYM338 prevents myostatin- or activin A-induced atrophy through inhibition of
Smad2/3 phosphorylation, thus sparing the myosin heavy chain from degradation.
BYM338 dramatically increases skeletal muscle mass in mice, beyond sole
inhibition of myostatin, detected by comparing the antibody with a myostatin
inhibitor. A mouse version of the antibody induces enhanced muscle hypertrophy
in myostatin mutant mice, further confirming a beneficial effect on muscle
growth beyond myostatin inhibition alone through blockade of ActRII ligands.
BYM338 protects muscles from glucocorticoid-induced atrophy and weakness via
prevention of muscle and tetanic force losses. These data highlight the
compelling therapeutic potential of BYM338 for the treatment of skeletal muscle
atrophy and weakness in multiple settings. OBJECTIVE: To study activin signaling and its blockade in sporadic inclusion
body myositis (sIBM) through translational studies and a randomized controlled
trial.
METHODS: We measured transforming growth factor β signaling by SMAD2/3
phosphorylation in muscle biopsies of 50 patients with neuromuscular disease (17
with sIBM). We tested inhibition of activin receptors IIA and IIB (ActRII) in 14
patients with sIBM using one dose of bimagrumab (n = 11) or placebo (n = 3). The
primary outcome was the change in right thigh muscle volume by MRI at 8 weeks.
Lean body mass, strength, and function were secondary outcomes. Twelve of the
patients (10 bimagrumab, 2 placebo) participated in a subsequent 16-week
observation phase.
RESULTS: Muscle SMAD2/3 phosphorylation was higher in sIBM than in other muscle
diseases studied (p = 0.003). Eight weeks after dosing, the bimagrumab-treated
patients increased thigh muscle volume (right leg +6.5% compared with placebo, p
= 0.024; left leg +7.6%, p = 0.009) and lean body mass (+5.7% compared with
placebo, p = 0.014). Subsequently, bimagrumab-treated patients had improved
6-minute walking distance, which peaked at 16 weeks (+14.6%, p = 0.008) compared
with placebo. There were no serious adverse events; the main adverse events with
bimagrumab were mild acne and transient involuntary muscle contractions.
CONCLUSIONS: Transforming growth factor β superfamily signaling, at least
through ActRII, is implicated in the pathophysiology of sIBM. Inhibition of
ActRII increased muscle mass and function in this pilot trial, offering a
potential novel treatment of sIBM.
CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for
patients with inclusion body myositis, bimagrumab increases thigh muscle volume
at 8 weeks. Bone is a biomechanical tissue shaped by forces from muscles and gravitation.
Simultaneous bone and muscle decay and dysfunction (osteosarcopenia or
sarco-osteoporosis) is seen in ageing, numerous clinical situations including
after stroke or paralysis, in neuromuscular dystrophies, glucocorticoid excess,
or in association with vitamin D, growth hormone/insulin like growth factor or
sex steroid deficiency, as well as in spaceflight. Physical exercise may be
beneficial in these situations, but further work is still needed to translate
acceptable and effective biomechanical interventions like vibration therapy from
animal models to humans. Novel antiresorptive and anabolic therapies are
emerging for osteoporosis as well as drugs for sarcopenia, cancer cachexia or
muscle wasting disorders, including antibodies against myostatin or activin
receptor type IIA and IIB (e.g. bimagrumab). Ideally, increasing muscle mass
would increase muscle strength and restore bone loss from disuse. However, the
classical view that muscle is unidirectionally domit over bone via mechanical
loading is overly simplistic. Indeed, recent studies indicate a role for
neuronal regulation of not only muscle but also bone metabolism, bone signaling
pathways like receptor activator of nuclear factor kappa-B ligand (RANKL)
implicated in muscle biology, myokines affecting bone and possible
bone-to-muscle communication. Moreover, pharmacological strategies inducing
isolated myocyte hypertrophy may not translate into increased muscle power
because tendons, connective tissue, neurons and energy metabolism need to adapt
as well. We aim here to critically review key musculoskeletal molecular pathways
involved in mechanoregulation and their effect on the bone-muscle unit as a
whole, as well as preclinical and emerging clinical evidence regarding the
effects of sarcopenia therapies on osteoporosis and vice versa. Bimagrumab (BYM338) is a novel fully human monoclonal antibody that exerts
strong promyogenic effects on skeletal muscle by blocking activin type II
receptors (ActRII). We investigated whether such blockade of ActRII by
bimagrumab manifests any detrimental effect on outcomes of bone healing in a rat
fibula osteotomy model. Animals (n = 150) were divided into 11 groups and
received weekly treatment with either bimagrumab (10 or 100 mg/kg) or vehicle.
Progression and outcomes of bone healing were assessed by lateral radiographs in
vivo as well as by peripheral quantitative computed tomography (pQCT), 4-point
bending test, and microscopic examination of the excised fibula at Day 29 or
later. The radiographic progression of bone healing showed no significant
differences between treatment groups in any comparative setting. In 3-month-old
animals, pQCT revealed slightly reduced immature callus size and bone mineral
content in bimagrumab-treated animals compared with vehicle-treated animals at
Day 29 (p < 0.05). There were, however, no differences in mature callus size,
bone mineral density, or biomechanical competency. The aforementioned effects on
immature callus size were not present when the treatment was initiated 4 weeks
post osteotomy or when treating 6-month-old animals. In summary, these findings
suggest that there is no major impact of ActRII blockade on overall fracture
healing, and delayed treatment initiation can bypass the small and transient
effect of the therapy on immature callus formation observed in younger animals.
Verification of these findings in humans is the subject of an ongoing clinical
trial on elderly hip fracture patients. BACKGROUND: Cachexia affects the majority of patients with advanced cancer and
is associated with reduced treatment tolerance, response to therapy, quality of
life, and life expectancy. Cachectic patients with advanced cancer often receive
anti-cancer therapies against their specific cancer type as a standard of care,
and whether specific ActRII inhibition is efficacious when combined with
anti-cancer agents has not been elucidated yet.
METHODS: In this study, we evaluated interactions between ActRII blockade and
anti-cancer agents in CT-26 mouse colon cancer-induced cachexia model. CDD866
(murinized version of bimagrumab) is a neutralizing antibody against the activin
receptor type II (ActRII) preventing binding of ligands such as myostatin and
activin A, which are involved in cancer cachexia. CDD866 was evaluated in
association with cisplatin as a standard cytotoxic agent or with everolimus, a
molecular-targeted agent against mammalian target of rapamycin (mTOR). In the
early studies, the treatment effect on cachexia was investigated, and in the
additional studies, the treatment effect on progression of cancer and the
associated cachexia was evaluated using body weight loss or tumor volume as
interruption criteria.
RESULTS: Cisplatin accelerated body weight loss and tended to exacerbate
skeletal muscle loss in cachectic animals, likely due to some toxicity of this
anti-cancer agent. Administration of CDD866 alone or in combination with
cisplatin protected from skeletal muscle weight loss compared to animals
receiving only cisplatin, corroborating that ActRII inhibition remains fully
efficacious under cisplatin treatment. In contrast, everolimus treatment alone
significantly protected the tumor-bearing mice against skeletal muscle weight
loss caused by CT-26 tumor. CDD866 not only remains efficacious in the presence
of everolimus but also showed a non-significant trend for an additive effect on
reversing skeletal muscle weight loss. Importantly, both combination therapies
slowed down time-to-progression.
CONCLUSIONS: Anti-ActRII blockade is an effective intervention against cancer
cachexia providing benefit even in the presence of anti-cancer therapies.
Co-treatment comprising chemotherapies and ActRII inhibitors might constitute a
promising new approach to alleviate chemotherapy- and cancer-related wasting
conditions and extend survival rates in cachectic cancer patients. BACKGROUND: Patients experiencing disuse atrophy report acute loss of skeletal
muscle mass which subsequently leads to loss of strength and physical capacity.
In such patients, especially the elderly, complete recovery remains a challenge
even with improved nutrition and resistance exercise. This study aimed to
explore the clinical potential of bimagrumab, a human monoclonal antibody
targeting the activin type II receptor, for the recovery of skeletal muscle
volume from disuse atrophy using an experimental model of lower extremity
immobilization.
METHODS: In this double-blind, placebo-controlled trial, healthy young men
(n = 24; mean age, 24.1 years) were placed in a full-length cast of one of the
lower extremities for 2 weeks to induce disuse atrophy. After cast removal,
subjects were randomized to receive a single intravenous (i.v.) dose of either
bimagrumab 30 mg/kg (n = 15) or placebo (n = 9) and were followed for 12 weeks.
Changes in thigh muscle volume (TMV) and inter-muscular adipose tissue (IMAT)
and subcutaneous adipose tissue (SCAT) of the thigh, maximum voluntary knee
extension strength, and safety were assessed throughout the 12 week study.
RESULTS: Casting resulted in an average TMV loss of -4.8% and comparable
increases in IMAT and SCAT volumes. Bimagrumab 30 mg/kg i.v. resulted in a rapid
increase in TMV at 2 weeks following cast removal and a +5.1% increase above
pre-cast levels at 12 weeks. In comparison, TMV returned to pre-cast level at
12 weeks (-0.1%) in the placebo group. The increased adiposity of the casted leg
was sustained in the placebo group and decreased substantially in the bimagrumab
group at Week 12 (IMAT: -6.6%, SCAT: -3.5%). Knee extension strength decreased
by ~25% in the casted leg for all subjects and returned to pre-cast levels
within 6 weeks after cast removal in both treatment arms. Bimagrumab was well
tolerated with no serious or severe adverse events reported during the study.
CONCLUSIONS: A single dose of bimagrumab 30 mg/kg i.v. safely accelerated the
recovery of TMV and reversal of accumulated IMAT following 2 weeks in a
joint-immobilizing cast. BACKGROUND: Bimagrumab is a human monoclonal antibody inhibitor of activin type
II receptors (ActRII), with anabolic action on skeletal muscle mass by blocking
binding of myostatin and other negative regulators of muscle growth. Bimagrumab
is under evaluation for muscle wasting and associated functional loss in hip
fracture and sarcopenia, and in obesity. Bimagrumab also blocks other endogenous
ActRII ligands, such as activins, which act on the neurohormonal axes,
pituitary, gonads and adrenal glands.
AIM: To evaluate the effect of bimagrumab on the pituitary-gonadal and
pituitary-adrenal axes in humans.
METHODS: Healthy men and women, aged 55 to 75 years, received bimagrumab
intravenously 10 mg/kg or placebo on Day 1 and Day 29. Pituitary-gonadal and
pituitary-adrenal functions were evaluated with basal hormone measurement and
standard gonadotropin-releasing hormone (GnRH) and adrenocorticotropic hormone
(ACTH) stimulation tests at baseline, Week 8 and at the end of study (EOS)-Week
20.
RESULTS: At Week 8, follicle-stimulating hormone (FSH) levels were reduced by
42.16 IU/L (P < .001) and luteinizing hormone (LH) levels were increased by 2.5
IU/L (P = .08) over placebo in response to bimagrumab in women but not in men.
Effects that were reversible after bimagrumab was cleared. Gonadal and adrenal
androgen levels were not affected by exposure to bimagrumab.
CONCLUSION: Bimagrumab alters the function of pituitary gonadotroph cells,
consistent with blockade of activin on local ActRII. This effect is reversible
with clearance of bimagrumab. Bimagrumab did not impact gonadal and adrenal
androgen secretion. RATIONALE: Bimagrumab is a fully human monoclonal antibody that blocks the
activin type II receptors, preventing the activity of myostatin and other
negative skeletal muscle regulators.
OBJECTIVES: To assess the effects of bimagrumab on skeletal muscle mass and
function in patients with chronic obstructive pulmonary disease (COPD) and
reduced skeletal muscle mass.
METHODS: Sixty-seven patients with COPD (mean FEV1, 1.05 L [41.6% predicted];
aged 40-80 yr; body mass index < 20 kg/m2 or appendicular skeletal muscle mass
index ≤ 7.25 [men] and ≤ 5.67 [women] kg/m2), received two doses of either
bimagrumab 30 mg/kg intravenously (n = 33) or placebo (n = 34) (Weeks 0 and 8)
over 24 weeks.
MEASUREMENTS AND MAIN RESULTS: We assessed changes in thigh muscle volume (cubic
centimeters) as the primary endpoint along with 6-minute-walk distance (meters),
safety, and tolerability. Fifty-five (82.1%) patients completed the study. Thigh
muscle volume increased by Week 4 and remained increased at Week 24 in
bimagrumab-treated patients, whereas no changes were observed with placebo (Week
4: +5.9% [SD, 3.4%] vs. 0.0% [3.3%], P < 0.001; Week 8: +7.0% [3.7%] vs. -0.7%
[2.8%], P < 0.001; Week 16: +7.8% [5.1%] vs. -0.9% [4.5%], P < 0.001; Week 24:
+5.0% [4.9%] vs. -1.3% [4.3%], P < 0.001). Over 24 weeks, 6-minute-walk distance
did not increase significantly in either group. Adverse events in the bimagrumab
group included muscle-related symptoms, diarrhea, and acne, most of which were
mild in severity.
CONCLUSIONS: Blocking the action of negative muscle regulators through the
activin type II receptors with bimagrumab treatment safely increased skeletal
muscle mass but did not improve functional capacity in patients with COPD and
low muscle mass. Clinical trial registered with www.clinicaltrials.gov
(NCT01669174). A global, randomized, double-blind placebo-controlled study was conducted to
confirm that BYM338 (bimagrumab), an anti-activin type II receptor antibody,
improves motor function in patients with sporadic inclusion body myositis after
52 weeks' treatment consisting of intravenous administration every 4 weeks at
doses of 10, 3, and 1 mg/kg. In a Japanese sub-population (20 patients in total,
5 per dose group), no significant differences in the change from baseline of the
6-minute walking distance at Week 52 (primary endpoint) were observed between
the placebo group and each BYM338 dose group. Furthermore, the lean body mass as
an indicator of skeletal muscle mass increased in all BYM338 groups compared
with the placebo group and the effects were dose-dependent. Overall, the
Japanese sub-population showed similar trends as observed in the entire
population (251 patients in total). |
Where is the yeast transpozable element Ty3 preferentially inserted? | Ty3 is preferentially inserted in genes encoding transfer RNA genes. | The function of a TATA element in RNA polymerase (EC 2.7.7.6) III transcription
of a naturally TATA-containing U6 snRNA gene and a naturally TATA-less tRNA gene
was probed by transcription and Ty3 transposition analyses. Deletion of the TATA
box from a U6 minigene did not abolish transcription and Ty3 integration but
changed the positions of initiation and insertion. Insertion of the U6 TATA box
at three positions upstream of the TATA-less SUP2 tRNA(Tyr) gene resulted in
novel transcription initiation and Ty3 integration patterns that depended upon
position of the insertion. Nevertheless, the predomit tRNA gene initiation
sites were not affected by insertion of the TATA sequence and remained at a
fixed distance from the internal box A promoter element. Insertions of the TATA
box upstream of a SUP2 box A mutant affected the level of transcription and
restricted the use of upstream start sites, but they neither enhanced the use of
TATA-dependent initiation sites nor restored expression to the level of the
wild-type gene. We conclude that (i) the U6 TATA box is essential in vivo for
correct initiation but not for transcription, (ii) a TATA box does not
compensate for a weak box A sequence and so cannot perform equivalently, and
(iii) the TATA-binding protein, and probably components of transcription factor
IIIB, are present on the target at the time of Ty3 integration. Retroviruses in nondividing cells and yeast retrotransposons must transit the
nuclear membrane in order for integration to occur. Mutations in a bipartite
basic motif in the carboxyl-terminal domain of the Ty3 integrase (IN) protein
were previously shown to block transposition at a step subsequent to 3'-end
processing of Ty3 extrachromosomal DNA. In this work, the Ty3 IN was shown to be
sufficient to target green fluorescent protein to the nucleolus. Mutations in
the bipartite basic motif abrogated this localization. The region containing the
motif was shown to be sufficient for nuclear but not subnuclear localization of
a heterologous protein. Viruslike particles (VLPs) from cells expressing a Ty3
element defective for nuclear localization were inactive in an in vitro
integration assay, suggesting that nuclear entry is required to form active VLPs
or that this motif is required for post-nuclear entry steps. Ty3 inserts at
transcription initiation sites of genomic tRNA genes and plasmid-borne 5S and U6
RNA genes transcribed by RNA polymerase III. In situ hybridization with Ty3- and
Ty3 long terminal repeat-specific probes showed that these elements which are
associated with tRNA genes do not colocalize with the ribosomal DNA (rDNA).
However, a PCR assay of cells undergoing transposition showed that Ty3 insertion
does occur into the 5S genes, which, in yeast, are interspersed with the rDNA
and therefore, like Ty3 IN, associated with the nucleolus. |
List features of the Currarino triad. | Currarino syndrome is a congenital malformation syndrome typically characterized by sacral agenesis, anorectal malformation, and presence of a pre-sacral mass. | The Currarino triad is a unique complex of congenital caudal anomalies including
anorectal malformation, sacral bony abnormality, and presacral mass. The usual
symptomatology is constipation due to anorectal stenosis. Contrast enema and
computed tomographic myelography are the imaging modalities of choice for
diagnostic confirmation and clarification of the anomalies. The clinical
features, unique radiologic appearance, and importance of a correct diagnosis of
the Currarino triad are reviewed. The association of congenital anal stenosis, scimitar-shaped sacral defect and a
presacral mass is known as the Currarino triad. These patients present with
constipation of variable severity which may result from a combination of
compression by the mass, neurogenic dysfunction as well as anal stenosis itself.
We have treated three patients who illustrate the spectrum of severity of this
condition. All had an associated tethered cord. One was cured by a single anal
dilatation, cord release and anterior meningocele repair. The second did not
improve after anoplasty and neurosurgical intervention. A previously diagnosed
rectal ectasia was felt to be contributory to the constipation and was treated
by low anterior resection with excellent results. The third patient developed an
ischiorectal abscess that required drainage and colostomy after unsuccessful
dilatation of a very tight and deeply scarred anal stenosis. A subsequent
tethered cord release and closure of the anterior meningocele was followed by an
anoplasty. Colostomy was closed at a later date. In all patients with anal
stenosis a search should be made for a presacral mass and its associated sacral
defect. Release of the tethered cord, resection of the presacral mass and/or
closure of the anterior meningocele are essential for optimal functional
results. The Currarino triad is a hereditary transmitted syndrome, originally defined by
Currarino as ASP-association, consisting of an anorectal malformation, a sacral
bony defect and a presacral mass. In most cases autosomal domit transmission
is suggested. In family members one or two features of the syndrome may be
missing, indicating an incomplete form of this complex. We describe two
unrelated girls at the age of 8 and 9 months respectively with ASP-association.
Family screening in both patients showed 8 additional cases with a complete or
incomplete Currarino triad, four of them being asymptomatic. A review of the
literature up to 1991 revealed 48 patients with ASP-association. In more than
80% of cases, this complex is diagnosed in the first decade, whereas incomplete
Currarino syndrome is diagnosed predomitly in adults. Most frequently the
presacral mass in ASP-association was reported to be an anterior meningocele
(47%) and a benign teratoma (40%). The number of patients with Currarino
syndrome has been underestimated so far. We recommend anorectal examination,
pelvic ultrasound and pelvic x-rays in all patients with a history of chronic
constipation since early childhood. Positive findings should lead to further
investigations such as barium enema, MRI, myelography and family screening.
Close cooperation between pediatric surgeons and neurosurgeons is required to
ensure adequate surgical treatment, considering both the risk of maligt
degeneration as well as the risk of intraoperative nerve damage. Thus, radical
excisional surgery is not obligatory in every case of Currarino syndrome. The Currarino triad is a unique complex of congenital caudal anomalies including
anorectal malformation, sacral bone abnormality, and presacral mass. In this
report, the authors describe three cases with the complete Currarino triad in a
family. The authors treated a 30-year-old mother with an anterior sacral
meningocele, her 1-year-old son with a combination of anterior sacral
meningocele and dermoid cyst, and her 4-year-old daughter with an epidermoid
cyst. These three patients had associated sacral agenesis and anorectal
malformations. To the authors' knowledge, this is the first report describing
radiological and operative findings of complete familial Currarino triad in
which a mother and her two children were affected. PURPOSE: Currarino triad, which comprises anorectal stenosis, anterior sacral
defect, and a presacral mass, is an uncommon cause of constipation in children
and adults. The presacral mass in this triad is most often caused by an anterior
sacral meningocele, a teratoma, or an enterogenous cyst, but rarely may be
caused by dual pathology. A neonate with Currarino triad and dual pathology in
the presacral mass is described in this report.
METHOD: A male Chinese neonate, who presented with abdominal distention and
constipation on the second day of life, was found to have features of Currarino
triad. Colostomy was done in the neonatal period, and the presacral mass was
excised by posterior sagittal perineal approach at the age of six months.
RESULTS: The excised presacral mass consisted of an anterior meningocele and a
teratoma. The patient continued to have constipation during follow-up and
required anorectoplasty to correct residual anorectal stenosis. At the time of
this report the patient was three years old and growing normally with normal
anorectal function.
DISCUSSION: Of a total of about 200 cases of complete Currarino triad found in
the literature, in only 22 patients did the presacral mass contain both
meningocele and teratoma. The features of these 22 patients and the current
views on the surgical management of Currarino triad are discussed. The Currarino triad is a complex anomaly consisting of an anorectal
malformation, a sacral bone defect and a presacral mass. It was first described
in 1981 and since then, approximately 250 cases have been reported. Radiology
has an important part to play in the diagnosis of this entity, as the imaging
features are characteristic. We report a case of Currarino triad in an infant
who presented with intractable constipation and discuss relevant MRI and plain
radiography findings. The Currarino triad, also known as the "Currarino Syndrome", is a rare complex
of congenital caudal anomalies including three main features; a sacral bony
deformity, anorectal malformations, and a presacral mass. We present an
extremely uncommon case of Currarino syndrome in adulthood presenting with
repeated episodes of meningitis. Magnetic resoce imaging of spine was
suggestive of caudal regression. Cord was low lying, conus ending at L3 level
with evidence of tethering at that level. A large cyst was noted in the sacral
canal extending forwards in the pelvis through the widened sacral foramina on
right side. She was operated through a posterior approach, via sacral
laminectomy. Dura was opened in the midline, large silvery white epidermoid
tumor was found completely occupying the anterior sacral meningocele. The case
and relevant literature is discussed. INTRODUCTION: Currarino syndrome (Currarino triad) was described in 1981 as a
triad syndrome with a common embryogenesis in infants and with three
characteristics: anorectal stenosis, a defect in the sacral bone, and a
presacral mass. We describe here an unusual case of Currarino syndrome in an
adult presenting with a presacral abscess but no meningitis.
CASE PRESENTATION: A 32-year-old Japanese man presented with fever, arthralgia
and buttock pain. A digital rectal examination showed mild rectal stenosis with
local warmth and tenderness in the posterior wall of his rectum. Computed
tomography showed a scimitar-shaped deformity of his sacrum and an 8cm presacral
mass, which continued to a pedicle of his deformed sacrum. This was diagnosed as
Currarino syndrome with a presacral abscess. The abscess was drained by a
perianal approach with our patient treated with antibiotics. His symptoms soon
disappeared. After three months, an excision was performed through a posterior
sagittal approach. His postoperative course was uneventful and he was discharged
10 days after surgery. A histopathological examination revealed an infected
epidermoid cyst. He has been free from recurrence as of four years and six
months after surgery.
CONCLUSIONS: We report a case of Currarino syndrome in an adult who presented
with a presacral abscess but no meningitis. Abscess drainage followed by radical
surgery resulted in a successful outcome. The Currarino triad is a unique complex of congenital caudal anomalies,
including anorectal malformation, sacral bony defect and presacral mass. This
triad may be associated with Müllerian duct anomalies, such as duplication of
the vagina and uterus. Each of these diseases has a familial tendency and
sometimes coexist within families. But, when coexisting in familial cases,
nearly all reported cases revealed mutations of the motor neuron and pancreas
homeobox 1 (MNX1) gene. Familial cases of Currarino triad combined with
Müllerian duct anomaly without MNX1 gene mutation are very rare. Here we report
cases of mother and daughter, who had Currarino triad and Müllerian duct anomaly
without MNX1 gene mutation, along with a brief literature review. Partial duplications of the long arm of chromosome 3, dup(3q), are a rare but
well-described condition, sharing features of Cornelia de Lange syndrome. Around
two thirds of cases are derived from unbalanced translocations, whereas pure
dup(3q) have rarely been reported. Here, we provide an extensive review of the
literature on dup(3q). This search revealed several patients with caudal
malformations and anomalies, suggesting that caudal malformations or anomalies
represent an inherent phenotypic feature of dup(3q). In this context, we report
a patient with a pure de novo duplication 3q26.32-q27.2. The patient had the
clinical diagnosis of Currarino syndrome (CS) (characterized by the triad of
sacral anomalies, anorectal malformations and a presacral mass) and additional
features, frequently detected in patients with a dup(3q). Mutations within the
MNX1 gene were found to be causative in CS but no MNX1 mutation could be
detected in our patient. Our comprehensive search for candidate genes located in
the critical region of the duplication 3q syndrome, 3q26.3-q27, revealed a so
far neglected phenotypic overlap of dup(3q) and the Pierpont syndrome,
associated with a mutation of the TBL1XR1 gene on 3q26.32. BACKGROUND: The major genetic cause of Currarino syndrome (CS), a congenital
malformation syndrome typically characterized by sacral agenesis, anorectal
malformation, and presence of a pre-sacral mass, is known to be pathogenic
variants in motor neuron and pancreas homeobox 1 (MNX1), which exist in almost
all familial cases and 30% of sporadic cases. Less commonly, a large deletion or
a complex rearrangement involving the 7q36 region is associated with CS. We
investigated the spectrum of MNX1 pathogenic variants and associated clinical
features in the Korean patients with CS.
METHODS: We enrolled 25 patients with CS, including 24 sporadic cases and one
familial case. Direct sequencing of MNX1 and multiplex ligation-dependent probe
amplification were performed. We also analyzed clinical phenotypes and evaluated
genotype-phenotype correlations.
RESULTS: We identified six novel variants amongst a total of six null variants,
one missense variant, and one large deletion. The null variants included four
frameshift variants (p.Gly98Alafs* 124, p.Gly145Alafs*77, p.Gly151Leufs*67, and
p.Ala216Profs*5) and two nonsense variants (p.Tyr186* and p.Gln212*). The
missense variant, p.Lys295Gln, was located in the highly-conserved homeobox
domain and was predicted to be deleterious. A large deletion involving the 7q36
region was detected in one patient. Pathogenic variants in MNX1 were detected in
28% of all CS cases and 25% of sporadic cases. The clinical phenotype was
variable in patients with and without pathogenic variants; no significant
genotype-phenotype correlation was observed.
CONCLUSIONS: This study revealed the spectrum and phenotypic variability of MNX1
pathogenic variants in the Korean population. BACKGROUND: Currarino syndrome is a rare condition characterized by presacral
mass, anorectal malformation and sacral dysgenesis.
CASE PRESENTATION: We report the case of a child that presented chronic
constipation, encopresis and mycrocephaly. The characteristics were initially
compatible with a case of functional constipation and a therapy with
polyethylene glycol was prescribed. After a year, because of poor response, a
plain abdominal X-ray was performed, detecting sacrum abnormalities. Finally, a
CGH-array analysis was performed and a form of Currarino Syndrome caused by a
rare 7q36 microdeletion, was diagnosed.
CONCLUSION: Occult spinal dysraphism should be suspected in case of poor
polyethylene glycol responder constipation, even when evident sacral
abnormalities on the physical examination are not detected. |
When was Afrezza approved by the FDA? | Afrezza was approved by the FDA in June 2014. | The current review was designed to compare between the insulin inhalation
systems Exubera and Afrezza and to investigate the reasons why Exubera was
unsuccessful, when Afrezza maker is expecting their product to be felicitous. In
January 2006, Pfizer secured FDA and EC approval for the first of its kind,
regular insulin through Exubera inhaler device for the management of types 1 and
2 diabetes mellitus (DM) in adults. The product was no longer available to the
market after less than two years from its approval triggering a setback for
competitive new inhalable insulins that were already in various clinical
development phases. In contrary, MannKind Corporation started developing its
ultra-rapid-acting insulin Afrezza in a bold bid, probably by managing the
issues in which Exubera was not successful. Afrezza has been marketed since
February, 2015 by Sanofi after getting FDA approval in June 2014. The results
from this systematic review indicate the effectiveness of insulin inhalation
products, particularly for patients initiating insulin therapy. Pharmaceutical
companies should capitalize on the information available from insulin inhalation
to produce competitive products that are able to match the bioavailability of
subcutaneous (SC) insulin injection and to deal with the single insulin unit
increments and basal insulin requirements in some diabetic patients or extending
the horizon to inhalable drug products with completely different drug entities
for other indications. |
What are invasomes | Ultra-flexible vesicles, e.g. invasomes and core-multishell (CMS) nanotransporters are efficient drug delivery systems | The present study compares three vesicular systems, cationic LeciPlex,
invasomes, and conventional liposomes for their ability to deliver drugs deep
into the skin. Skin penetration ability of the three vesicular systems was
studied for two drugs namely idebenone (antioxidant/anticancer) and azelaic acid
(antiacne). All systems showed sizes in ometer range with small
polydispersity indices. Vesicular systems were characterized by CryoTEM studies
to understand the differences in morphology of the vesicular systems. Ex vivo
human skin penetration studies suggested a pattern in penetration of drugs in
different layers of the skin: LeciPlex showed higher penetration for idebenone
whereas invasomes showed higher penetration of azelaic acid. Ex vivo study using
a fluorescent dye (DiI) was performed to understand the differences in the
penetration behavior of the three vesicular systems on excised human skin. In
vitro cytotoxicity studies on B16F10 melanoma cell lines revealed, when loaded
with idebenone, LeciPlex formulations had the superior activity followed by
invasomes and liposomes. In vitro antimicrobial study of azelaic acid loaded
systems on Propionibacterium acne revealed high antimicrobial activity for DDAB
leciplex followed by almost equal activity for invasomes and CTAB LeciPlex
followed by liposomes. Whereas antiacne efficacy study in rats for azelaic acid
loaded systems, invasomes exhibited the best antiacne efficacy followed by
liposomes and LeciPlex. BACKGROUND: Improvisation of the osized vesicular systems has led to a series
of useful developments including the deformable vesicles namely transfersomes,
ethosomes and invasomes. The former two have been explored extensively, however,
literature on invasomes is relatively scanty.
METHOD: Invasomal formulations researched for various applications have been
reviewed using search engine "Scopus". The present review focuses on the update
of the research activity on effectiveness and permeation enhancing effects of
invasomes for dermal and topical delivery.
RESULT: Many research reports could be found on invasomes in the literature but
scarce patent citations were found. The present write up elaborates the
mechanism of penetration, and compiles literature dental applications of the
invasomes, the detection ability, use in photodynamic therapy, pilosebaceous
targeting, and for delivery of macromolecules. The use of massage and
microneedles for penetration enhancement is the newer element in this area.
Interestingly, the majority of research has been reported on temoporfin molecule
but scarce literature is available for other molecules, so the area provides
ample research opportunities. The review also highlights toxicity fact sheet of
commonly used terpenes for invasome formulation.
CONCLUSION: Though invasomes present an advantageous system for enhanced topical
delivery but it needs to be assessed for dermatopharmacokinetics; safety and
toxicity issues on long term usage. |
Which T-UCRs have been implicated in lung cancer? | Transcribed ultraconserved regions (T-UCRs) classified as long non-coding RNAs (Lnc-RNAs) are transcripts longer than 200-nt RNA with no protein-coding capacity. The clinicopathologic significance and regulatory mechanism of T-UCRs in lung cancer (LC) remain largely unknown. Uc.454 is downregulated in both non-small-cell LC (NSCLC) tissues and LC cell lines, and the downregulated uc.454 is associated with tumor size and tumors with more advanced stages. Transfection with uc.454 markedly induces apoptosis and inhibites cell proliferation in SPC-A-1 and NCI-H2170 LC cell lines. Thus uc.454 potentially plays a suppressive role in LC. Transcribed uc.339 is upregulated in archival NSCLC samples, functioning as a decoy RNA for miR-339-3p, -663b-3p, and -95-5p. As a result, Cyclin E2, a direct target of all these microRNAs is upregulated, promoting cancer growth and migration. Modulation of uc.339 affects microRNA expression. However, overexpression or downregulation of these microRNAs causes no significant variations in uc.339 levels. | Author information:
(1)Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST)
S.r.l., IRCCS, Gene Therapy Unit, 47014, Meldola (FC), Italy.
(2)Departments of Pediatrics and Molecular Microbiology & Immunology, Norris
Comprehensive Cancer Center, Keck School of Medicine, University of Southern
California, Children's Center for Cancer and Blood Diseases and The Saban
Research Institute, Children's Hospital Los Angeles, Los Angeles, CA, 90027,
USA.
(3)Department of Biochemistry and Molecular Biology, University of Nebraska
Medical Center, 985870 Nebraska Medical Center, Omaha, NE, 68198, USA.
(4)Department of Internal Medicine, Division of Pulmonary, Allergy, Critical
Care and Sleep Medicine, The Ohio State University, Columbus, OH, 43210, USA.
(5)Department of Experimental, Diagnostic and Specialty Medicine-DIMES,
University of Bologna, 40126, Bologna, Italy.
(6)Department of Experimental Therapeutics, The University of Texas MD Anderson
Cancer Center, Houston, TX, 77030, USA.
(7)The Center for RNA Interference and Non-coding RNAs, The University of Texas
MD Anderson Cancer Center, Houston, 77030, TX, USA.
(8)Departments of Preventive Medicine and Neurological Surgery, Northwestern
University-Feinberg School of Medicine, Chicago, IL, 60611, USA.
(9)Department of Experimental Radiation Oncology, The University of Texas MD
Anderson Cancer Center, Houston, TX, 77030, USA.
(10)Department of Gynecologic Oncology and Reproductive Medicine, The University
of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
(11)Integrated Molecular Discovery Laboratory, Department of Experimental
Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX,
77030, USA.
(12)Department of Molecular Virology, Immunology and Medical Genetics,
Comprehensive Cancer Center, Ohio State University, Columbus, OH, 43210, USA.
(13)Department of Biochemistry and Molecular Biology, McGovern Medical School,
The University of Texas Health Science Center at Houston, Houston, TX, 77030,
USA.
(14)Istituto Scientifico Romagnolo per lo Studio e la Cura dei Tumori (IRST)
S.r.l., IRCCS, Biosciences Laboratory Unit, 47014, Meldola (FC), Italy.
(15)Division of Medical Oncology, Norris Comprehensive Cancer Center, Keck
School of Medicine, University of Southern California, Los Angeles, CA, 90033,
USA.
(16)Departments of Surgery and Biochemistry and Molecular Medicine, Norris
Comprehensive Cancer Center, Keck School of Medicine, University of Southern
California, Los Angeles, CA, 90033, USA.
(17)Division of Pulmonary Diseases and Critical Care Medicine, Virginia
Commonwealth University, Richmond, VA, 23298, USA.
(18)Department of Morphology, Surgery and Experimental Medicine and Laboratory
for Technologies of Advanced Therapies (LTTA), University of Ferrara, 44121,
Ferrara, Italy.
(19)Department of Bioinformatics and Computational Biology, The University of
Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
(20)Department of Oncology Unit, Istituto Scientifico Romagnolo per lo Studio e
la Cura dei Tumori (IRST) S.r.l., IRCCS, 47014, Meldola (FC), Italy.
(21)Institute of Genetics and Biophysics, National Research Council, 80131,
Naples, Italy.
(22)Department of Experimental Therapeutics, The University of Texas MD Anderson
Cancer Center, Houston, TX, 77030, USA. [email protected].
(23)The Center for RNA Interference and Non-coding RNAs, The University of Texas
MD Anderson Cancer Center, Houston, 77030, TX, USA. [email protected].
(24)Departments of Pediatrics and Molecular Microbiology & Immunology, Norris
Comprehensive Cancer Center, Keck School of Medicine, University of Southern
California, Children's Center for Cancer and Blood Diseases and The Saban
Research Institute, Children's Hospital Los Angeles, Los Angeles, CA, 90027,
USA. [email protected]. Transcribed ultraconserved regions (T-UCRs) classified as long non-coding RNAs
(Lnc-RNAs) are transcripts longer than 200-nt RNA with no protein-coding
capacity. Previous studies showed that T-UCRs serve as novel oncogenes, or tumor
suppressors are involved in tumorigenesis and cancer progressive. Nevertheless,
the clinicopathologic significance and regulatory mechanism of T-UCRs in lung
cancer (LC) remain largely unknown. We found that uc.454 was downregulated in
both non-small-cell LC (NSCLC) tissues and LC cell lines, and the downregulated
uc.454 is associated with tumor size and tumors with more advanced stages.
Transfection with uc.454 markedly induced apoptosis and inhibited cell
proliferation in SPC-A-1 and NCI-H2170 LC cell lines. Above results suggested
that uc.454 played a suppressive role in LC. Heat shock protein family A member
12B (HSPA12B) protein was negatively regulated by uc.454 at the
posttranscriptional level by dual-luciferase reporter assay and affected the
expressions of Bcl-2 family members, which finally induced LC apoptosis. The
uc.454/HSPA12B axis furthers our understanding of the molecular mechanisms
involved in tumor apoptosis, which may potentially serve as a therapeutic target
for lung carcinoma. |
Can Daptacel be used instead of IPOL? | No, Daptacel is a diphtheria, tetanus, 5-component acellular pertussis vaccine, while IPOL is an inactivated poliovirus vaccine. | |
Is ACE2 expressed on cell surfaces? | Yes,
ACE2 is a type 1 integral membrane protein and contains a catalytically active ectodomain that can be shed from the cell surface into the extracellular space. | Angiotensin-converting enzyme 2 (ACE2) is a recently described member of the
renin-angiotensin system that hydrolyzes angiotensin (Ang) II to Ang-(1-7), and
may thereby protect against cardiovascular and renal diseases. ACE2 is a type 1
integral membrane protein and contains a catalytically active ectodomain that
can be shed from the cell surface into the extracellular space, via cleavage by
a disintegrin and metalloproteinase-17 (ADAM-17). ACE2 enzymatic activity and
protein can be detected in biological fluids, including urine, plasma, and
conditioned cell culture media. We present a detailed method for measurement of
ACE2 activity in biological fluids, using hydrolysis of an intramolecularly
quenched fluorogenic ACE2 substrate, in the absence or presence of the ACE2
inhibitors MLN-4760 or DX600. Recombit human or mouse ACE2 is used to
generate standard curves for this assay, with ACE2 detection ranging from 1.56
to 50 ng/ml. While MLN-4760 potently inhibits the activity of both human and
mouse ACE2, DX600 (linear form) only effectively blocks human ACE2 activity in
this assay. In biological samples of human and mouse urine, cell culture medium
from mouse proximal tubular cells, and mouse plasma, the mean intra- and
inter-assay coefficients of variation (CVs) of the assay range from 1.43 to 4.39
%, and from 7.01 to 13.17 %, respectively. We present data on the time and
substrate concentration dependence of the assay, and show that exogenous D
-glucose, creatinine, urea, and albumin do not interfere with its performance.
In biological fluids, this assay is a simple and reliable method to study the
role of ACE2 and its shed fragments in cardiovascular and renal diseases. |
List symptoms of the One-and-a-half syndrome. | One-and-a-half syndrome is defined by conjugated horizontal gaze palsy and internuclear ophthalmoplegia. | The one-and-a-half syndrome is characterised by a lateral gaze palsy in one
direction and internuclear ophthalmoplegia in the other. It is due to a
unilateral lesion of the dorsal pontine tegmentum, involving the ipsilateral
paramedian pontine reticular formation, internuclear fibres of the ipsilateral
medical longitudinal fasciculus and, usually, the abducens nucleus. The main
causes of this rare syndrome are stroke and multiple sclerosis. Few cases have
been reported since the introduction of MRI. Our aim was to examine
clinicoradiological correlations in six patients with a one-and-a-half syndrome
due to a stroke. Ophthalmological symptoms were diplopia, oscillopsia or blurred
vision. Four patients had an associated facial nerve palsy, three a hemiparesis
and one a unilateral hemihypoaesthesia. MRI revealed an infarct in the pons in
all patients. The cause of the infarct was a basilar artery dissection in one
patient, bilateral vertebral artery dissection in a second and unknown in the
other four. All patients recovered within 2 days to 8 weeks. This study showed a
good correlation between the site of the lesion (superior, inferior or extensive
pontine ischaemia) and clinical deficits. A 52-year-old patient developed an eye movement disorder first resembling a left
internuclear ophthalmoplegia and subsequently a "one-and-a-half syndrome" as the
presenting symptoms of ocular myasthenia gravis. No accompanying myasthenic
features were present except for the fluctuation in the amplitude of dissociated
nystagmus. This patient shows that an oculomotor disorder considered a typical
pontine lesion may instead be caused by myasthenia gravis, even in the absence
of other clinical and electrophysiologic features of neuromuscular deficit. One-and-a-half syndrome is a clinical disorder featuring extraocular movements
characterized by horizontal conjugate gaze palsy with internuclear
ophthalmoplegia. It usually results from a unilateral lesion of the midbrain,
and the most common cause of this syndrome in young women is multiple sclerosis.
We report the case of a 38-year-old woman diagnosed as having acute myeloblastic
leukemia presenting with characteristic neurologic and imaging features of
one-and-a-half syndrome. Hyperleukocytosis, cancer procoagulants, tissue factor
expression, and the increased proteolysis of coagulation factors by leukemic
cells may all contribute to the propensity for thrombotic vascular occlusion.
The optimal treatment of acute brain infarction in acute leukemia patients with
hyperleukocytosis remains unclear. However, this patient illustrates that
leukapheresis alone can provide rapid and effective relief of visual symptoms
without neurologic sequela. To achieve better outcomes and survival, clinicians
must maintain a heightened awareness of this distinctly unusual manifestation. We report a unique neuroophthalmological syndrome consisting of vertical
one-and-a-half syndrome-resulting from a combination of supranuclear conjugate
upgaze palsy associated with left infranuclear (fascicular) third nerve
involvement (Weber syndrome)-with concomitant contralesional pseudo-abducens
palsy. Magnetic resoce imaging confirmed that this unusual clinical
combination was the result of two infarcts one in the left thalamomesencephalic
junction and another affecting the left infrategmental paramedian area of the
rostral midbrain. We discuss the clinical topography of both
neuroophthalmological findings. This unusual neuroophthalmological finding has
not been reported. A 42-year-old young lady presented with acute onset of dizziness, drooping of
left eye with binocular diplopia and inability to walk unassisted. She had past
history of uncontrolled diabetes mellitus and hypertension. On examination, she
had left fascicular type of third nerve palsy, vertical one and half syndrome
(VOHS), left internuclear ophthalmoplegia and skew deviation with ipsilesional
hypertropia. She also had thalamic astasia and right unilateral asterixis. Her
MRI revealed T2 and Flair hyper intense signal changes with restricted diffusion
in the left thalamus, subthalamus and left midbrain. MR Angiography was normal.
Thalamic-subthalamic paramedian territory infarct is relatively uncommon. It can
present with oculomotor abnormalities including vertical one and half syndrome,
skew deviation, thalamic astasia and asterixis. This case is reported for the
rarity of the presenting clinical findings in unilateral thalamo-mesencephalic
infarcts. We describe a rare case in which both wall-eyed bilateral internuclear
ophthalmoplegia syndrome and vertical one-and-a-half syndrome were observed in a
68-year-old man with acute ischemic stroke. Concurrent horizontal and vertical
gaze palsies are rare because the corresponding gaze centers are anatomically
separated. The complicated gaze palsies observed in this patient might have
resulted from long, vertical lesions affecting oculomotor pathways for both
sides of the brain stem. "Eight-and-a-half" syndrome is "one-and-a-half" syndrome (conjugated horizontal
gaze palsy and internuclear ophthalmoplegia) plus ipsilateral fascicular cranial
nerve seventh palsy. This rare condition, particularly when isolated, is caused
by circumscribed lesions of the pontine tegmentum involving the abducens
nucleus, the ipsilateral medial longitudinal fasciculus, and the adjacent facial
colliculus. Its recognition is therefore of considerable diagnostic value. We
report a case of a 65-year-old man who presented with eight-and-a-half syndrome
in which brain magnetic resoce imaging scan revealed a lacunar pontine
infarction. BACKGROUND AND PURPOSE: Unilateral gaze palsy associated with internuclear
ophthalmoplegia (INO), i.e., one-and-a-half syndrome, is well known. Exotropia
can also be associated with INO, but it has been reported only rarely. We sought
to determine the frequencies and courses of gaze palsy and exotropia in INO.
METHODS: Patients hospitalized with acute-onset INO during the period January
2009 through December 2013 were identified from our clinical registry.
Associated gaze palsy and exotropia were evaluated in the identified patients.
RESULTS: Twenty-five patients with unilateral INO and 7 patients with bilateral
INO were included in this study. Of the 25 patients with unilateral INO, 4
(16.0.0%) had ipsilateral gaze palsy (one-and-a-half syndrome), 8 (32.0%) had
exotropia (non-paralytic pontine exotropia), and 6 (24.0%) had both ipsilateral
gaze palsy and exotropia (paralytic pontine exotropia). Six (85.7%) of the 7
patients with bilateral INO had exotropia. The gaze palsy persisted more than 1
week in 40.0% of patients, whereas the exotropia disappeared within 1 week in
92.9% of patients when the INO was unilateral.
CONCLUSION: Exotropia is not uncommon in the acute stage of INO. However, it is
often overlooked because of its short duration. The authors report a case of a 22-year-old otherwise healthy female who
presented following a head injury during a bar altercation, with no associated
loss of consciousness and an unknown mechanism of injury. Examination revealed
an isolated 1cm laceration on the right upper eyelid, superior to her medial
canthus. She experienced diplopia on right horizontal gaze due to a left
internuclear ophthalmoplegia (INO) with an associated left conjugate horizontal
gaze palsy, collectively described as a left one-and-a-half syndrome. CT and MRI
demonstrated evidence of a deep penetrating injury above the right medial
canthus, traversing the ethmoid and sphenoid sinuses, the dorsum sella, narrowly
missing the basilar artery, penetrating the pons, and extending to the floor of
the contralateral fourth ventricle. The patient was diagnosed with multiple
sinus fractures, lesions in her left paramedian pontine reticular formation
(PPRF) and medial longitudinal fasciculus (MLF), and progressive pneumocephalus.
She underwent a transsphenoidal endoscopic repair via a vascularized mucosal
flap without complication. Postoperatively, the patient's pneumocephalus
resolved and her conjugate gaze markedly improved; however, minimal diplopia
remained. This case demonstrates the importance of the clinical exam, and its
benefit in localizing imaging findings and guiding treatment. We report a case of 43-year-old male, presented with sudden onset binocular
diplopia on lateral gazes. Ocular examination showed features of ipsilateral
one-and-a-half syndrome. Comprehensive systemic work in conjunction with
magnetic resoce imaging of the brain illustrated irregular mixed solid and
cystic lesions in the brainstem, possibly indicative of brain metastases.
Further imaging revealed hidden renal cell carcinoma as a primary neoplasm,
which led to secondary manifestations. One-and-a-half syndrome is a syndrome characterized by horizontal movement
disorders of the eyeballs, which was first reported and named by Fisher in 1967.
It presents a combination of ipsilateral conjugate horizontal gaze palsy (one)
and ipsilateral internuclear ophthalmoplegia (INO) (a half). On the basis of the
one-and-a-half syndrome, there are a series of related rare syndromes called the
one-and-a-half syndrome spectrum disorders. This article reviews rare cases of
one-and-a-half syndrome spectrum disorder, describes the clinical and
pathological features of different syndromes, and summarizes their nomenclature. RATIONALE: One-and-a-half syndrome (OAAH) is characterized as the combination of
ipsilateral horizontal gaze palsy and internuclear ophthalmoplegia. OAAH
syndrome accompanied with 7th and 8th cranial nerve palsy is called
16-and-a-half syndrome. We aimed to report the case of 16-and-a-half syndrome
with metastatic pons tumor.
PATIENT CONCERNS: A 57-year-old male diagnosed with nonsmall-cell lung cancer
(NSCLC) with brain metastasis occurring 15 months ago was referred to our clinic
with the chief complaint of horizontal diplopia and right gaze palsy.
DIAGNOSIS: According to the patient symptom, ocular examination, and
radiographic findings, he was diagnosed as 16-and-a-half syndrome which was
caused by brain tumor metastasis from NSCLC.
INTERVENTIONS: We referred him to hemato-oncology department and he was treated
with radiation and supportive therapy.
OUTCOMES: Unfortunately, the patient passed away 1 month later without
improvement of ophthalmoplegia.
LESSONS: The clinical findings of our case indicate 16-and-a-half syndrome
caused by brain tumor metastasis from NSCLC, which to our knowledge has not been
previously reported. The case highlights a rare cause of OAAH spectrum disease
and the importance of a systemic work-up including associated neurologic
symptoms and brain imaging in patients with horizontal gaze palsy. |
When was Fluzone Intradermal replaced with Fluzone Intradermal Quadrivalent? | Fluzone Intradermal was replaced with Fluzone Intradermal Quadrivalent vaccine in advance of the 2015-2016 season. | INTRODUCTION: An intradermal version of Fluzone® split-virion inactivated
trivalent influenza vaccine, containing 9 µg hemagglutinin per strain of A/H1N1,
A/H3N2, and one B lineage virus (Fluzone Intradermal, Sanofi Pasteur), became
available in the US during the 2011-2012 influenza season for adults 18-64 years
of age. In advance of the 2015-2016 season, Fluzone Intradermal was replaced
with Fluzone Intradermal Quadrivalent vaccine, which contains 9 µg hemagglutinin
per strain of the two A-strain viruses and both B-strain lineage viruses
(Victoria and Yamagata).
AREAS COVERED: This literature review summarizes the history and mechanism of
intradermal vaccination, discusses the clinical trial results supporting the
immunogenicity and safety of Fluzone Intradermal Quadrivalent vaccine, and
describes the unique microinjection system used to deliver Fluzone Intradermal
Quadrivalent. Expert commentary: Fluzone Intradermal Quadrivalent may boost
confidence in influenza vaccination with the addition of a second B-lineage
strain. By using an innovative microinjection system, the vaccine is also
designed to address some of the logistic challenges faced by healthcare
providers administering immunizations. |
List the cancers that are associated with SBLA syndrome. | Li-Fraumeni syndrome is an autosomal dominant inherited disorder also known as the SBLA cancer syndrome (sarcoma, breast, leukemia, and adrenal). Li-Fraumeni syndrome (LFS) is characterized by a pleth | Choroid plexus neoplasms are rare epithelial tumors of the central nervous
system. A carcinoma of the choroid plexus occurred in a child from a family with
the breast cancer-sarcoma syndrome (Li-Fraumeni or SBLA syndrome), an inherited
condition characterized by the development of diverse neoplasms (sarcoma, breast
cancer, brain tumors, leukemia, adrenal cortical carcinoma, and others). Choroid
plexus carcinomas were identified in two kindreds previously reported with the
syndrome. The literature contains reports of choroid plexus neoplasms occurring
in families and in individuals with multiple primary tumors. Choroid plexus
neoplasm may be a manifestation of the inherited proclivity to tumor development
in the breast cancer-sarcoma syndrome. We have provided an in-depth, longitudinal, clinical/genetic/pathologic
investigation of a family consot with the sarcoma, breast cancer and brain
tumors, lung and laryngeal cancer, leukemia, lymphoma, and adrenalcortical
carcinoma syndrome. The pattern of cancer expression involves all three germinal
layers with transmission through multiple generations. Segregation of these
cancers occur in a manner consot with an autosomal domit mode of genetic
transmission. It is hoped that recognition of the significance of this tumor
pattern within families will provide an impetus for cancer surveillance,
control, and laboratory research in the quest for clues to biomarkers which
correlate with its cancer-prone genotype. A histological analysis was conducted in 138 female breast cancer patients, and
the results were classified in accordance with "Histological Typing of Breast
Tumours" (WHO, Geneva 1981). Since about half of these tumors showed more than
one histological type of carcinoma, a simplified classification system with four
groups was adopted. When patients were categorized according to the number and
degree of kinship of their relatives with breast cancer, no specific association
with the histological types was found. Familial tumors also encompassed a wide
spectrum of histopathologic diagnoses. This suggests the absence of a
histological marker in familial breast cancer. Pedigrees of all the patients
were then analyzed, special emphasis being placed on relatives suffering from
the same and other maligcies. It was found that 13.8% of the probands had at
least one first-degree relative with breast cancer and that, compared with the
tumor spectra in the male and female population, there was a significantly
higher number of esophageal carcinomas in the fathers, of stomach cancers in the
uncles and grandfathers, of brain tumors in the mothers, and of sarcomas in the
brothers. An accumulation of the same tumors, especially stomach cancer and
tumors related to the SBLA syndrome, was observed in families of index patients
with tubular or medullary breast cancer. The SBLA syndrome is a complex familial
cancer syndrome characterized by a proclivity to Sarcomas, Breast cancers, brain
tumors, Lung and laryngeal cancers, leukemia, and Adrenocortical carcinomas. Hereditary breast cancer (HBC) shows extant clinical and genetic heterogeneity.
Clinically one finds the onset of breast cancer at an early age, an excess of
bilaterality, and patterns of multiple primary cancer such as combinations of
breast and ovarian carcinoma in the hereditary breast-ovarian cancer (HBOC)
syndrome. In addition to HBOC, one sees a variety of putative breast
cancer-prone genotypes inclusive of hereditary site-specific breast cancer, and
the Li-Fraumeni (SBLA) syndrome that is characterized by cancers involving all
three germinal layers including sarcomas, brain tumors, leukemia, lymphoma, and
adrenal cortical carcinoma in addition to often markedly early-onset breast
cancer. Breast cancer is also associated with autosomal domitly inherited
Cowden's disease and autosomal recessively inherited ataxia-telangiectasia.
Examples of pedigrees depicting clinical examples of these several HBC syndromes
are presented in order to describe HBC's heterogeneity. The recent
identification of the BRCA1 gene in early-onset hereditary site-specific breast
cancer and the HBOC syndrome has led to new challenges for the genetic
counselor. We review genetic counseling, which embraces surveillance and
management recommendations that are responsive to the natural history of HBC and
address the concept for future development of centers of expertise for HBC in
the interest of improving cancer control. BACKGROUND: Li-Fraumeni syndrome (LFS) is characterized by a plethora of
cancers, most prominent of which is carcinoma of the breast followed by
sarcomas, brain tumors, leukemia, lymphoma, lung carcinoma, and adrenocortical
carcinoma (therefore, also referred to by the acronym SBLA syndrome).
METHODS: The family reported herein was first described 2 decades ago. Now
extensive follow-up has shown the predictable occurrence of these tumor types,
in addition to an excess of brain tumors and the finding of Sturge-Weber
syndrome (SWS) in an LFS-affected family member.
RESULTS: A possible new feature of the disorder, suggestive of SWS, was
identified in a patient in the direct genetic lineage. This patient had a
rhabdomyosarcoma of the eyelid at age 29 months and at age 14 years was
diagnosed with lymphoblastic lymphoma/acute lymphoblastic leukemia. A remarkable
excess of brain tumors was identified in this family through this current
update. The p53 germ-line mutation was not identified in any affected member of
this family.
CONCLUSIONS: To the authors' knowledge, this is the first example of SWS in the
context of LFS. Brain tumors appear to be an important component of the tumor
spectrum of LFS, as evidenced in this family. |
Can leuprorelin acetate be used as androgen deprivation therapy? | Yes, leuprorelin acetate is being used as androgen deprivation therapy. | INTRODUCTION: We investigated the health-related quality of life (HRQoL) of
long-term prostate cancer patients who received leuprorelin acetate in
microcapsules (LAM) for androgen-deprivation therapy (ADT).
METHODS: The observational study was carried out by 30 office-based German
urologists in 536 prostate cancer (PCa) patients treated for ≥5 years with LAM
and in 116 patients of an age-matched control group (CG). Data on HRQoL and
health status was collected prospectively using validated questionnaires
QLQ-C30, QLQ-PR25 and Karnofsky Index. Data on effectiveness (clinical response,
prostate specific antigen [PSA], testosterone) and safety was collected
retrospectively from patients' health records. We used descriptive statistics to
analyze the data.
RESULTS: The mean treatment duration was 8.6 years (range 4.5-19.8 years).
General health status (QLQ-C30) was comparable for both groups. Differences were
observed regarding physical - and role functioning. ADT patients rated single
items slightly worse than CG. Karnofsky-Index showed comparable high values
(median of 90%). QLQ-PR25 revealed more PCa-related symptoms for ADT patients.
Within 6 months, median PSA level declined >90% and median testosterone levels
declined below castration level from 4.0 to 0.2 ng/mL. Clinical response
(European Organisation for Research and Treatment of Cancer criteria) was
observed in at least 90% of ADT patients.
CONCLUSIONS: Long-term ADT with LAM is a well-accepted, tolerated, effective,
and low-burden treatment option for patients with advanced, hormone-sensitive
PCa. |
Which factors are included in the the APPEND score? | APPEND score components are anorexia, migratory Pain, local Peritonism, Elevated C-reactive protein, Neutrophilia and male gender (Dude). It is an acute appendicitis clinical prediction rule. | BACKGROUND: Although many clinical prediction rules (CPRs) for appendicitis
exist, none have been developed for a New Zealand population presenting with
right iliac fossa (RIF) pain. The aim of this study was to derive and validate
an appendicitis CPR for our population.
METHOD: This is a retrospective review of all patients from December 2010 to
February 2012 of at least 15 years of age presenting to the general surgery
service with RIF pain. Patient data were divided into derivation and validation
groups. Univariate and multiple regression analyses identified significant
predictors of appendicitis which were used to construct a CPR. A retrospective
validation study was then performed and the CPR was refined accordingly.
Finally, the accuracy of the CPR was tested.
RESULTS: The final components of the new CPR, the APPEND score, were Anorexia,
migratory Pain, local Peritonism, Elevated C-reactive protein, Neutrophilia and
male gender (Dude). This CPR has an area under the receiver operating
characteristic curve of 0.84. The CPR can stratify patients into low,
intermediate and high-risk groups which may standardize patient care and reduce
the negative appendicectomy rate.
CONCLUSION: A new CPR for predicting appendicitis, in patients presenting with
RIF pain, has been derived and validated for use in our population. A
prospective study to further evaluate its performance is required. |
What is the function of the SSX proteins? | The SYT protein appears to act as a transcriptional co-activator and the SSX proteins as co-repressors | Cancer-testis antigens (CTAs) represent an expanding class of tumor-associated
proteins defined on the basis of their tissue-restricted expression to testis or
ovary germline cells and frequent ectopic expression in tumor tissue. The
expression of CTA in MHC class I-deficient germline cells makes these proteins
particularly attractive as immunotherapeutic targets because they serve as
essentially tumor-specific antigens for MHC class I-restricted CD8+ T cells.
Moreover, because CTAs are expressed in many types of cancer, any therapeutic
developed to target these antigens might have efficacy for multiple cancer
types. Of particular interest among CTAs is the synovial sarcoma X chromosome
breakpoint (SSX) family of proteins, which includes ten highly homologous family
members. Expression of SSX proteins in tumor tissues has been associated with
advanced stages of disease and worse patient prognosis. Additionally, both
humoral and cell-mediated immune responses to SSX proteins have been
demonstrated in patients with tumors of varying histological origin, which
indicates that natural immune responses can be spontaneously generated to these
antigens in cancer patients. The current review will describe the history and
identification of this family of proteins, as well as what is known of their
function, expression in normal and maligt tissues, and immunogenicity. |
Are astrocytes part of the blood brain barrier? | Yes
The blood-brain barrier (BBB) is a tight boundary formed between endothelial cells and astrocytes, which separates and protects brain from most pathogens as well as neural toxins in circulation. | The blood-brain barrier (BBB) consists of endothelial cells, astrocytes, and
pericytes embedded in basal lamina (BL). Most in vitro models use nonhuman,
monolayer cultures for therapeutic-delivery studies, relying on transendothelial
electrical resistance (TEER) measurements without other tight-junction (TJ)
formation parameters. We aimed to develop reliable, reproducible, in vitro
3-dimensional (3D) models incorporating relevant human, in vivo cell types and
BL proteins. The 3D BBB models were constructed with human brain endothelial
cells, human astrocytes, and human brain pericytes in mono-, co-, and
tricultures. TEER was measured in 3D models using a volt/ohmmeter and
cellZscope. Influence of BL proteins-laminin, fibronectin, collagen type IV,
agrin, and perlecan-on adhesion and TEER was assessed using an electric
cell-substrate impedance-sensing system. TJ protein expression was assessed by
Western blotting (WB) and immunocytochemistry (ICC). Perlecan (10 µg/ml) evoked
unreportedly high, in vitro TEER values (1200 Ω) and the strongest adhesion.
Coculturing endothelial cells with astrocytes yielded the greatest resistance
over time. ICC and WB results correlated with resistance levels, with evidence
of prominent occludin expression in cocultures. BL proteins exerted differential
effects on TEER, whereas astrocytes in contact yielded higher TEER values and TJ
expression.-Maherally, Z., Fillmore, H. L., Tan, S. L., Tan, S. F., Jassam, S.
A., Quack, F. I., Hatherell, K. E., Pilkington, G. J. Real-time acquisition of
transendothelial electrical resistance in an all-human, in vitro, 3-dimensional,
blood-brain barrier model exemplifies tight-junction integrity. |
What is Invaplex 50? | The Shigella flexneri Invaplex 50 is a macromolecular complex containing IpaB, IpaC, and LPS, formulated from an aqueous extract of virulent Shigella delivered via nasal administration. It is used against shigellosis, a leading cause of diarrhea worldwide. The Invaplex 50 nasal vaccine was safe with encouraging mucosal immune responses. | Shigellosis is a leading cause of diarrhea worldwide prompting vaccine
development. The Shigella flexneri Invaplex 50 is a macromolecular complex
containing IpaB, IpaC, and LPS, formulated from an aqueous extract of virulent
Shigella delivered via nasal administration. Preclinical vaccine testing
demonstrated safety, immunogenicity and efficacy. An open-label dose-escalating
phase 1 study evaluated a 3-dose (2-week intervals) regimen via nasal pipette
delivery. Thirty-two subjects were enrolled into one of four vaccine dose groups
(10, 50, 240, or 480 microg). The vaccine was well tolerated with minor
short-lived nasal symptoms without evidence of dose effect. Antibody-secreting
cell (ASC) responses were elicited at doses > or =50 microg with the highest IgG
ASC, Invaplex 50 (100%) and S. flexneri 2a LPS (71%), as well as, serologic
responses (43%) occurring with the 240 microg dose. Fecal IgA responses,
Invaplex 50 (38.5%) and LPS (30.8%), were observed at doses > or =240 microg.
The Invaplex 50 nasal vaccine was safe with encouraging mucosal immune
responses. Follow-on studies will optimize dose, delivery mechanism and assess
efficacy in a S. flexneri 2a challenge study. |
Which X chromosome abnormalities present lupus-like symptoms? | Lupus-like symptoms of systemic lupus erythematosus (SLE) are caused by X-linked mutations in the genes Tlr7 and Y. | |
Which lncRNAS are regulated by SAM68? | Hotair, Mir155hg, as well as SR-lncRNA-1 and SR-lncRNA-2 are regulated by Sam68, and contained consensus Sam68 binding sites. | The KH-type RNA binding protein Sam68 is required for adipogenesis. We have
previously shown that Sam68-deficient mice have a lean phenotype and are
protected against dietary-induced obesity due to defects in mTOR and S6K1
alternative splicing. Herein we profiled the transcriptome of Sam68 wild type
and deficient 3T3-L1 mouse preadipocytes. We identified 652 protein-coding genes
and 9 ncRNAs that were significantly altered with the loss of Sam68. As
expected, downregulated genes were significantly associated with GO terms linked
to cell migration, motility, and fat cell differentiation, while upregulated
genes were mostly associated with GO terms linked to neurogenesis. Of the
lncRNAs, we identified Hotair, Mir155hg, as well as two new lncRNAs (SR-lncRNA-1
and SR-lncRNA-2) that were regulated by Sam68, and contained consensus Sam68
binding sites. RNA stability assays showed that Sam68-deficiency decreased the
half-life of Hotair, and increased the half-lives of Mir155hg and SR-lncRNA-2,
while the stability of SR-lncRNA-1 was unaffected. Depletion of Hotair and
SR-lncRNA-1 in wild type 3T3-L1 cells led to defects in adipogenesis, whereas
depletion of SR-lncRNA-2 in Sam68-deficient 3T3-L1 cells partially rescued the
adipogenesis defect observed in these cells. Collectively, our findings define a
new role for Sam68 as a regulator of lncRNAs during adipogenic differentiation. |
How many proteins have been queried for protein partners by the Drosophila protein interaction map (DPiM)? | Over 5,000 proteins have been queried for protein partners by the Drosophila protein interaction map (DPiM). | Proteins perform essential cellular functions as part of protein complexes,
often in conjunction with RNA, DNA, metabolites and other small molecules. The
genome encodes thousands of proteins but not all of them are expressed in every
cell type; and expressed proteins are not active at all times. Such diversity of
protein expression and function accounts for the level of biological intricacy
seen in nature. Defining protein-protein interactions in protein complexes, and
establishing the when, what and where of potential interactions, is therefore
crucial to understanding the cellular function of any protein-especially those
that have not been well studied by traditional molecular genetic approaches. We
generated a large-scale resource of affinity-tagged expression-ready clones and
used co-affinity purification combined with tandem mass-spectrometry to identify
protein partners of nearly 5,000 Drosophila melanogaster proteins. The resulting
protein complex "map" provided a blueprint of metazoan protein complex
organization. Here we describe how the map has provided valuable insights into
protein function in addition to generating hundreds of testable hypotheses. We
also discuss recent technological advancements that will be critical in
addressing the next generation of questions arising from the map. |
What is known about the orphan receptor GPR151? | Gpr151 is an orphan GPCR whose function is unknown. The restricted pattern of neuronal expression in the habenula, dorsal horn of the spinal cord and dorsal root ganglion plus homology with the galanin family of receptors imply a role in nociception.
Our data demonstrate that GPR151 is highly conserved, specific for a subdivision of the habenular neurocircuitry, and constitutes a promising novel target for psychiatric drug development. | The habenula is a phylogenetically conserved brain structure in the epithalamus.
It is a major node in the information flow between fronto-limbic brain regions
and monoaminergic brainstem nuclei, and is thus anatomically and functionally
ideally positioned to regulate emotional, motivational, and cognitive behaviors.
Consequently, the habenula may be critically important in the pathophysiology of
psychiatric disorders such as addiction and depression. Here we investigated the
expression pattern of GPR151, a G protein-coupled receptor (GPCR), whose mRNA
has been identified as highly and specifically enriched in habenular neurons by
in situ hybridization and translating ribosome affinity purification (TRAP). In
the present immunohistochemical study we demonstrate a pronounced and highly
specific expression of the GPR151 protein in the medial and lateral habenula of
rodent brain. Specific expression was also seen in efferent habenular fibers
projecting to the interpeduncular nucleus, the rostromedial tegmental area, the
rhabdoid nucleus, the mesencephalic raphe nuclei, and the dorsal tegmental
nucleus. Using confocal microscopy and quantitative colocalization analysis, we
found that GPR151-expressing axons and terminals overlap with cholinergic,
substance P-ergic, and glutamatergic markers. Virtually identical expression
patterns were observed in rat, mouse, and zebrafish brains. Our data demonstrate
that GPR151 is highly conserved, specific for a subdivision of the habenular
neurocircuitry, and constitutes a promising novel target for psychiatric drug
development. GPR151 is a G-protein coupled receptor for which the endogenous ligand remains
unknown. In the nervous system of vertebrates, its expression is enriched in
specific diencephalic structures, where the highest levels are observed in the
habenular area. The habenula has been implicated in a range of different
functions including behavioral flexibility, decision making, inhibitory control,
and pain processing, which makes it a promising target for treating psychiatric
and neurological disease. This study aimed to further characterize neurons
expressing the Gpr151 gene, by tracing the afferent connectivity of this
diencephalic cell population. Using pseudotyped rabies virus in a transgenic
Gpr151-Cre mouse line, monosynaptic afferents of habenular and thalamic
Gpr151-expressing neuronal populations could be visualized. The habenular and
thalamic Gpr151 systems displayed both shared and distinct connectivity
patterns. The habenular neurons primarily received input from basal forebrain
structures, the bed nucleus of stria terminalis, the lateral preoptic area, the
entopeduncular nucleus, and the lateral hypothalamic area. The Gpr151-expressing
neurons in the paraventricular nucleus of the thalamus was primarily contacted
by medial hypothalamic areas as well as the zona incerta and projected to
specific forebrain areas such as the prelimbic cortex and the accumbens nucleus.
Gpr151 mRNA was also detected at low levels in the lateral posterior thalamic
nucleus which received input from areas associated with visual processing,
including the superior colliculus, zona incerta, and the visual and
retrosplenial cortices. Knowledge about the connectivity of Gpr151-expressing
neurons will facilitate the interpretation of future functional studies of this
receptor. Author information:
(1)Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical
School, Boston, MA, 02114, USA.
(2)Department of Medicine, Massachusetts General Hospital, Cardiology Division,
Harvard Medical School, Boston, MA, 02114, USA.
(3)Program in Medical and Population Genetics, Broad Institute, Cambridge, MA,
02142, USA.
(4)Department of Surgery, Massachusetts General Hospital, Harvard Medical
School, Boston, MA, 02114, USA.
(5)Department of Computational Biology & Bioinformatics, Yale Medical School,
Yale University, New Haven, MA, 06510, USA.
(6)Division of Cardiology, Azienda Ospedaliero-Universitaria di Parma, Parma,
43121, Italy.
(7)Associazione per lo Studio Della Trombosi in Cardiologia, Pavia, 27100,
Italy.
(8)Department of Physiology and Biophysics, University of Mississippi Medical
Center, Jackson, MS, 39216, USA.
(9)Deutsches Herzzentrum München, Technische Universität München, Deutsches
Zentrum für Herz-Kreislauf-Forschung, München, 80333, Germany.
(10)University of Ottawa Heart Institute, Ottawa, ON, K1Y4W7, Canada.
(11)Radcliffe Department of Medicine, Division of Cardiovascular Medicine,
University of Oxford, Oxford, OX1 2JD, UK.
(12)Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX1
2JD, UK.
(13)Cardiovascular Epidemiology and Genetics, Hospital del Mar Research
Institute, Barcelona, 08003, Spain.
(14)CIBER Enfermedades Cardiovasculares (CIBERCV), Barcelona, 28029, Spain.
(15)Facultat de Medicina, Universitat de Vic-Central de Cataluña, Barcelona,
VIC, 08500, Spain.
(16)Department of Cardiovascular Sciences, University of Leicester, and NIHR
Leicester Biomedical Research Centre, Leicester, LE1 7RH, UK.
(17)The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of
Medicine at Mount Sinai, New York, 10029, NY, USA.
(18)Institute for Integrative and Experimental Genomics, University of Lübeck,
Lübeck, 23562, Germany.
(19)Department of Public Health and Primary Care, Cardiovascular Epidemiology
Unit, University of Cambridge, Cambridge, CB2 0SR, UK.
(20)Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1SA, UK.
(21)National Institute of Health Research Blood and Transplant; Research Unit in
Donor Health and Genomics, University of Cambridge, Cambridge, CB2 1TN, UK.
(22)Center for Cardiovascular Disease Prevention, Brigham and Women's Hospital,
Boston, 02115, USA.
(23)Department of Biomedical Informatics, Vanderbilt University, Nashville, TN,
37235, USA.
(24)Department of Chronic Disease Epidemiology, Yale School of Public Health,
New Haven, CT, 06510, USA.
(25)Department of Emergency Medicine, Yale University, New Haven, CT, 06520,
USA.
(26)Center for Outcomes Research and Evaluation, Yale-New Haven Hospital, New
Haven, CT, 06510, USA.
(27)Department of Biomedical & Saint Luke's Mid America Heart Institute and the
Health Informatics, Division of Endocrinology and Metabolism, University of
Missouri-Kansas City, Kansas City, MO, 64110, USA.
(28)Department of Internal Medicine, Taichung Veterans General Hospital,
Taichung, 40705, Taiwan.
(29)The Institute for Translational Genomics and Population Sciences, LABioMed
and Department of Pediatrics at Harbor-UCLA Medical Center, Torrance, CA, 90095,
USA.
(30)Cardiovascular Health Research Unit, Departments of Medicine, Epidemiology
and Health Services, University of Washington, Seattle, 98195, WA, USA.
(31)Cardiovascular Health Research Unit, Kaiser Permanente Washington Health
Research Institute, 98101, Seattle, WA, USA.
(32)Center for Public Health Genomics, University of Virginia School of
Medicine, Charlottesville, VA, 22908, USA.
(33)Division of Cardiology, Johns Hopkins University School of Medicine,
Baltimore, MD, 21205, USA.
(34)Center for Non-Communicable Diseases, Karachi, 74800, Pakistan.
(35)Department of Biostatistics and Epidemiology, Perelman School of Medicine,
University of Pennsylvania, Philadelphia, PA, 19104, USA.
(36)Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical
School, Boston, MA, 02114, USA. [email protected].
(37)Department of Medicine, Massachusetts General Hospital, Cardiology Division,
Harvard Medical School, Boston, MA, 02114, USA. [email protected].
(38)Program in Medical and Population Genetics, Broad Institute, Cambridge, MA,
02142, USA. [email protected]. |
Is Li–Fraumeni syndrome a rare, autosomal recessive, hereditary disorder that predisposes carriers to cancer development? | Li-Fraumeni syndrome is a rare, autosomal DOMINANT, hereditary disorder that predisposes carriers to cancer development. | Li-Fraumeni syndrome is a rare autosomal domit cancer predisposition
syndrome. The majority of families fulfilling definition of Li-Fraumeni syndrome
demonstrate inherited abnormalities involving the p53 gene. Cells with
dysfunctional p53 are predisposed to the development of cancer phenotype.
Advexin (Introgen Therapeutics Inc., TX, USA) is an adenoviral-based
experimental therapeutic that provides delivery of wild-type p53 to cancer cells
and demonstrates anticancer activity following adequate expression of p53.
Theoretically, correction of p53 function in cancer developing in patients with
Li-Fraumeni syndrome through treatment with Advexin will provide anti-tumor
activity. One patient with Li-Fraumeni syndrome has been reported to have
responded to Advexin. This review will summarize background knowledge of
Li-Fraumeni syndrome, mechanisms of Advexin and clinical response of cancer to
Advexin with a focus on Li-Fraumeni syndrome. Studies to determine the etiology of osteosarcoma involve epidemiologic and
environmental factors and genetic impairments. Factors related to patient
characteristics include age, gender, ethnicity, growth and height, genetic and
familial factors, and preexisting bone abnormalities. Rapidly proliferating
cells may be particularly susceptible to oncogenic agents and mitotic errors
which lead to neoplastic transformation. Genetic aberrations that accompany
osteosarcoma have received increasing recognition as an important factor in its
etiology. Osteosarcoma tumor cells exhibit karyotypes with a high degree of
complexity which has made it difficult to determine whether any recurrent
chromosomal aberrations characterize osteosarcoma. Although extremely rare,
osteosarcoma has occasionally been observed in several members of the same
family. No other clinical abnormalities in the proband or the affected members
were reported. Pathologic examination of the tumors revealed no unusual
features. Genetic testing was not available in most of these reports. The
patients generally responded to conventional therapy. A genetic predisposition
to osteosarcoma is found in patients with hereditary retinoblastoma,
characterized by mutation of the retinoblastoma gene RB1 on chromosome 13q14.
The Rothmund-Thomson syndrome is an autosomal recessive disorder with a
heterogeneous clinical profile. Patients may have a few or multiple clinical
features including skin rash, small stature, skeletal dysplasias, sparse or
absent scalp hair, eyebrows or eyelashes, juvenile cataracts, and
gastrointestinal disturbance including chronic emesis and diarrhea; its
molecular basis is the mutation in the RECQL4 gene in a subset of cases. The
Li-Fraumeni syndrome is an autosomal domit disorder characterized by a high
risk of developing osteosarcoma and has been found in up to 3% of children with
osteosarcoma. It is associated with a germline mutation of the p53, a suppressor
gene. The following three criteria must be met for a diagnosis of Li-Fraumeni
syndrome: (1) A proband diagnosed with sarcoma when younger than 45 years; (2) A
first-degree relative with any cancer diagnosed when younger than 45 years; (3)
Another first- or second-degree relative of the same genetic lineage with any
cancer diagnosed when younger than 45 years or sarcoma diagnosed at any age. A
second recessive p53 oncogene on chromosome 17p13.1 may also play a role in the
development and progression of osteosarcoma. Osteosarcoma has also been
associated with solitary or multiple osteochondroma, solitary enchondroma or
enchondromatosis (Ollier's disease), multiple hereditary exostoses, fibrous
dysplasia, chronic osteomyelitis, sites of bone infarcts, sites of metallic
prostheses and sites of prior internal fixation. Ionizing radiation is a
well-documented etiologic factor. Osteosarcoma has also been associated with the
use of intravenous radium and Thorotrast. Exposure to alkylating agents may also
contribute to its development ,and it is apparently independent of the
administration of radiotherapy. INTRODUCTION: The Li-Fraumeni syndrome (LFS) is an autosomal domit hereditary
disorder associated with different tumor types in childhood and young adults.
Approximately 70% of LFS cases contain germline mutations in the TP53 gene. We
report a case of a family suspected of LFS.
MATERIALS AND METHODS: The proband and four members of the family affected were
diagnosed with cancer at an early age and they all died except the proband.
Exons 5-9 from TP53 gene were analysed by direct amplification and sequencing in
7 family members.
RESULTS: The analysis revealed a germline nonsense mutation in exon 8 at codon
306 of the codified region of the TP53 gene, causing a change of CGA to TGA
(Arg→Stop) in the proband, her mother, her cousin and her maternal uncle.
Proband's maternal grandmother and aunt do not have the mutation.
CONCLUSIONS: The members of this family that were studied meet the criteria of
classic LFS and the described mutation increases their susceptibility to develop
cancer. The proband's maternal grandfather died of lung cancer in 1993, and we
believe that he was the carrier of the mutation in this family. Li-Fraumeni syndrome (LFS) is a rare autosomal domit disorder caused by a
mutation in the p53 gene. Melanoma is considered to be a rare, controversial
component of LFS. The aim of this study is to describe the utility of systematic
screening for melanoma in patients with LFS and atypical mole syndrome. Two
28-year-old identical twin sisters with LFS and atypical moles were monitored by
physical examination, total-body digital photography and dermoscopy be-tween
2006 and 2014. A total of 117, predomitly dark-brown, reticular naevi were
identified on case 1 and 105 on case 2. Excisions were performed during the
evaluation period of 1 in-situ melanoma and 3 basal cell carcinomas in case 1,
and 1 in-situ melanoma and 1 early invasive melanoma in case 2. The remaining
melanocytic lesions in both patients were stable during follow-up. The 3
melanomas were new atypical lesions detected with total-body photography and
dermoscopy. In conclusion, monitoring LFS patients with total-body photography
and dermoscopy may be useful to detect early melanoma. Li-Fraumeni syndrome (LFS) is a rare cancer predisposition syndrome inherited in
an autosomal domit fashion that involves a germline mutation of tumor protein
53 (TP53). With the advent of more accessible and accurate genetic testing
methods, along with more widespread knowledge of LFS, asymptomatic carriers can
now be more easily identified. No general surveillance protocols were previously
recommended other than routine physical exams and breast and colon cancer
screening at younger ages, primarily due to questions involving efficacy, cost,
and clinical benefits. With more data now available to support the
implementation of a surveillance protocol for cancer predisposition syndromes
such as LFS, preventative screening has become a national standard of care.
However, as surveillance becomes more integrated into patient care, the benefits
and risks must be further evaluated. We briefly describe our institutional
experience with surveillance screening in LFS and describe two patients in depth
where surveillance imaging brought to light false positives that led to
increased utilization of resources and concern for new maligcy. Though the
benefits of surveillance are clear, it is important to understand the potential
for false positives involved with instituting this practice. Continued research
of this topic is thus warranted, perhaps with larger prospective studies, to
better capture the survival benefits of patients undergoing surveillance
screening and more comprehensively understand the incidence of false positives. Li-Fraumeni syndrome (LFS) is an inherited, autosomal-domit condition that
predisposes individuals to a wide-spectrum of tumors at an early age.
Approximately 70% of families with classic LFS have pathogenic variants in the
tumor suppressor gene TP53 that disrupt protein function or stability. While
more than 70% of pathogenic variants in TP53 are missense variants, the vast
majority occur very infrequently, and thus their clinical significance is
uncertain or conflicting. Here, we report an extremely rare TP53 missense
variant, c.799C > T (p.Arg267Trp), identified in a 2-year-old Saudi proband
diagnosed with choroid plexus carcinoma (CPC) and six of his first- and
second-degree relatives. CPC is frequently found in families with LFS, and this
is the first detailed report of a family with this variant. Intriguingly, the
proband's father is homozygous for TP53 c.799C > T and phenotypically normal at
39 years of age. While loss of TP53 heterozygosity is often observed in tumors
from individuals with LFS, homozygous germline TP53 pathogenic variants are
rare. Based on our analysis of this single family, we hypothesize that TP53
c.799C > T has low or variable penetrance for LFS, with predisposition to the
development of CPC. The observations from this family have furthered our
understanding of the phenotypic variability that may be caused by one variant of
TP53, even in the same family, and suggest that other factors (genetic and/or
environmental) may play a role in mechanism of disease manifestation in LFS. |
Which is the target of belimumab in Systemic Lupus Erythematosus treatment? | Belimumab is a fully human monoclonal antibody directed against BAFF. Belimumab, a human monoclonal antibody specific for soluble BLyS, was ultimately approved by the United States Food and Drug Administration (FDA) in March 2011 for active autoantibody patients with systemic lupus erythematosus (SLE) despite standard therapy. | Systemic lupus erythematosus (SLE) is a chronic inflammatory disorder that is
driven by autoantibodies that target multiple organ systems. B-lymphocyte
stimulator (BLyS) and its receptors on B-cell subsets play an important role in
autoimmune B-cell development and SLE pathogenesis. Targeted therapy with
belimumab, the monoclonal antibody against BLyS, has shown clinical benefit in
two large-scale, multicenter phase III trials leading to US Food and Drug
Administration approval for patients with serologically positive SLE who have
active disease despite standard therapy. This review will discuss the challenges
in lupus drug development and clinical trials, the basics of B-cell pathogenesis
in SLE, the recent lupus clinical trials of B-cell targeted treatments, and
other potential targeted therapies under investigation for patients with lupus. There have been few changes over the last 50 years in the treatment of Systemic
lupus erythematosus (SLE), using non-specific anti-inflammatory agents such as:
nonsteroidal anti-inflammatory drugs along with the immune cell modulating agent
hydroxychloroquine for mild disease, and broad spectrum immunosuppressants plus
antiinflammatories such as corticosteroids, azathioprine, cyclophosphamide, or
mycophenolate during flares or severe disease with organ involvement. In some
patients, the response is inadequate and side effects appear from mild
unpleasant up to severe toxicity. Drug metabolism and clearance may be severely
compromised. Therefore, it is a priority to develop better treatments with fewer
adverse events that can be used at different stages of disease activity. In
recent years, a member of the tumor necrosis factor (TNF) family, soluble human
B Lymphocyte Stimulator protein (BLyS), also referred to as B-cell activating
factor (BAFF) and TNFSF13B has been studied extensively. This protein is
synthesized by myeloid cell lines, specifically interacts with B lymphocytes and
increases their life-span. BlyS plays a key role in the selection, maturation
and survival of B cells and it has a significant role in the pathogenesis of
SLE. In this review, we analyzed the role of BLyS as a diagnostic/prognostic
marker and/or therapeutic target for lupus patients, and the different clinical
studies published using belimumab. BAFF, a member of the TNF superfamily, has been recognized as a good target for
autoimmune diseases. Belimumab, an anti-BAFF monoclonal antibody, was approved
by the FDA for use in treating systemic lupus erythematosus. However, the
molecular basis of BAFF neutralization by belimumab remains unclear. Here our
crystal structure of the BAFF-belimumab Fab complex shows the precise epitope
and the BAFF-neutralizing mechanism of belimumab, and demonstrates that the
therapeutic activity of belimumab involves not only antagonizing the
BAFF-receptor interaction, but also disrupting the formation of the more active
BAFF 60-mer to favor the induction of the less active BAFF trimer through
interaction with the flap region of BAFF. In addition, the belimumab HCDR3 loop
mimics the DxL(V/L) motif of BAFF receptors, thereby binding to BAFF in a
similar manner as endogenous BAFF receptors. Our data thus provides insights for
the design of new drugs targeting BAFF for the treatment of autoimmune diseases. |
Salzburg EEG criteria are used to diagnose which disorder? | Salzburg EEG criteria are used to diagnose Nonconvulsive Status Epilepticus. | BACKGROUND: Salzburg Consensus Criteria for diagnosis of Non-Convulsive Status
Epilepticus (SCNC) were proposed at the 4th London-Innsbruck Colloquium on
status epilepticus in Salzburg (2013).
METHODS: We retrospectively analyzed the EEGs of 50 consecutive nonhypoxic
patients with diagnoses of nonconvulsive status epilepticus (NCSE) at discharge
and 50 consecutive controls with abnormal EEGs in a large university hospital in
Austria. We implemented the American Clinical Neurophysiology Society's
Standardized Critical Care EEG Terminology, 2012 version (ACNS criteria) to
increase the test performance of SCNC. In patients without preexisting epileptic
encephalopathy, the following criteria were applied: (1) more than 25
epileptiform discharges (ED) per 10-second epoch, i.e., >2.5/s and (2) patients
with EDs ≤ 2.5/s or rhythmic delta/theta activity (RDT) exceeding 0.5/s AND at
least one of the additional criteria: (2a) clinical and EEG improvements from
antiepileptic drugs (AEDs), (2b) subtle clinical phenomena, or (2c) typical
spatiotemporal evolution. In case of fluctuation without evolution or EEG
improvement without clinical improvement, "possible NCSE" was diagnosed. For
identification of RDT, the following criteria were compared: (test condition A)
continuous delta-theta activity without further rules, (B) ACNS criterion for
rhythmic delta activity (RDA), and (C) ACNS criteria for RDA and fluctuation.
RESULTS: False positive rate in controls dropped from 28% (condition A) to 2%
(B) (p = 0.00039) and finally to 0% (C) (p = 0.000042). Application of test
condition C in the group with NCSE gives one false negative (2%). Various EEG
patterns were found in patients with NCSE: (1) 8.2%, (2a) 2%, (2b) 12.2%, and
(2c) 32.7%. Possible NCSE was diagnosed based on fluctuations in 57.1% and EEG
improvement without clinical improvement in 14.2%.
CONCLUSION: The modified SCNC with refined definitions including the ACNS
terminology leads to clinically relevant and statistically significant reduction
of false positive diagnoses of NCSE and to minimal loss in sensitivity. This
article is part of a Special Issue entitled "Status Epilepticus". Nonconvulsive status epilepticus (NCSE) is common in patients with coma with a
prevalence between 5% and 48%. Patients in deep coma may exhibit epileptiform
EEG patterns, such as generalized periodic spikes, and there is an ongoing
debate about the relationship of these patterns and NCSE. The purposes of this
review are (i) to discuss the various EEG patterns found in coma, its
fluctuations, and transitions and (ii) to propose modified criteria for NCSE in
coma. Classical coma patterns such as diffuse polymorphic delta activity,
spindle coma, alpha/theta coma, low output voltage, or burst suppression do not
reflect NCSE. Any ictal patterns with a typical spatiotemporal evolution or
epileptiform discharges faster than 2.5 Hz in a comatose patient reflect
nonconvulsive seizures or NCSE and should be treated. Generalized periodic
diacharges or lateralized periodic discharges (GPDs/LPDs) with a frequency of
less than 2.5 Hz or rhythmic discharges (RDs) faster than 0.5 Hz are the
borderland of NCSE in coma. In these cases, at least one of the additional
criteria is needed to diagnose NCSE (a) subtle clinical ictal phenomena, (b)
typical spatiotemporal evolution, or (c) response to antiepileptic drug
treatment. There is currently no consensus about how long these patterns must be
present to qualify for NCSE, and the distinction from nonconvulsive seizures in
patients with critical illness or in comatose patients seems arbitrary. The
Salzburg Consensus Criteria for NCSE [1] have been modified according to the
Standardized Terminology of the American Clinical Neurophysiology Society [2]
and validated in three different cohorts, with a sensitivity of 97.2%, a
specificity of 95.9%, and a diagnostic accuracy of 96.3% in patients with
clinical signs of NCSE. Their diagnostic utility in different cohorts with
patients in deep coma has to be studied in the future. This article is part of a
Special Issue entitled "Status Epilepticus". BACKGROUND: Several EEG criteria have been proposed for diagnosis of
non-convulsive status epilepticus (NCSE), but none have been clinically
validated. We aimed to assess the diagnostic accuracy of the EEG criteria
proposed by a panel of experts at the fourth London-Innsbruck Colloquium on
Status Epilepticus in Salzburg, 2013 (henceforth called the Salzburg criteria).
METHODS: We did a retrospective, diagnostic accuracy study using EEG recordings
from patients admitted for neurological symptoms or signs to three centres in
two countries (Danish Epilepsy Centre, Dianalund, Denmark; Aarhus University
Hospital, Aarhus, Denmark; and Paracelsus Medical University, Salzburg,
Austria). Participants were included from the Danish centres if they were aged 4
months or older, and from the Austrian centre if aged 18 years or older.
Participants were sorted into two groups: consecutive patients under clinical
suspicion of having NCSE (the clinical validation group) or consecutive patients
with abnormal EEG findings but no clinical suspicion of NCSE (the control
group). Two raters blinded to all other patient data retrospectively analysed
the EEG recordings and, using the Salzburg criteria, categorised patients as in
NCSE or not in NCSE. By comparing with a reference standard inferred from all
clinical and para-clinical data, therapeutic response, and the final outcome, we
calculated sensitivity, specificity, overall diagnostic accuracy, positive and
negative predictive values, and inter-rater agreement for the Salzburg criteria.
The reference standard was inferred by two raters who were blinded to the
scorings of the Salzburg criteria.
FINDINGS: We retrospectively reviewed EEG data from 220 patients. EEGs in the
clinical validation group were recorded in 120 patients between Jan 1, and Feb
28, 2014 (Austria), and Aug 1, 2014, and Jan 31, 2015 (Denmark). EEGs in the
control group were recorded in 100 patients between Jan 13 and Jan 22, 2014
(Austria) and Jan 12 and Jan 26, 2015 (Denmark). According to the reference
standard, 43 (36%) of the 120 patients in the validation group had NCSE. In the
validation cohort sensitivity was 97·7% (95% CI 87·9-99·6) and specificity was
89·6% (80·8-94·6); overall accuracy was 92·5% (88·3-97·5). Positive predictive
value was 84·0% (95% CI 74·1-91·5) and negative predictive value was 98·6%
(94·4-100). Three people in the control group (n=100) fulfilled the Salzburg
criteria and were therefore false positives (specificity 97·0%, 95% CI
91·5-99·0; sensitivity not calculable). Inter-rater agreement was high for both
the Salzburg criteria (k=0·87) and for the reference standard (k=0·95).
Therapeutic changes occurred significantly more often in the group of patients
fulfilling Salzburg criteria (42 [84%] of 50 patients) than in those who did not
(11 [16%] of 70; p<0·0001).
INTERPRETATION: The Salzburg criteria for diagnosis of NCSE have high diagnostic
accuracy and excellent inter-rater agreement, making them suitable for
implementation in clinical practice.
FUNDING: None. PURPOSE: to investigate the semiology of subtle motor phenomena in critically
ill patients, with- versus without nonconvulsive status epilepticus (NCSE).
METHODS: 60 consecutive comatose patients, in whom subtle motor phenomena were
observed in the intensive care unit (ICU), were analysed prospectively. The
semiology of the subtle phenomena was described from video-recordings, blinded
to all other data. For each patient, the type, location and
occurrence-pattern/duration were described. EEGs recorded in the ICU were
classified using the Salzburg criteria for NCSE.
RESULTS: only 23% (14/60) of the patients had NCSE confirmed by EEG. None of the
semiological features could distinguish between patients with NCSE and those
without. In both groups, the following phenomena were most common: discrete
myoclonic muscle twitching and discrete tonic muscle activation. Besides these,
automatisms and eye deviation were observed in both groups.
CONCLUSION: subtle motor phenomena in critically ill patients can raise the
suspicion of NCSE. Nevertheless, EEG is needed to confirm the diagnosis, since
none of the semiological features are specific. OBJECTIVES: To investigate clinical characteristics and outcomes of
nonconvulsive status epilepticus (NCSE) after convulsive status epilepticus
(CSE) and determine risk factors for unfavorable outcomes.
METHODS: We reviewed consecutive patients with NCSE after CSE over eight years
in the neurological intensive care unit. Clinical presentations and the Salzburg
EEG criteria for NCSE were used to identify patients with NCSE after CSE.
Demographics, clinical features, and anti-epileptic treatment responses were
collected and analyzed. Modified Rankin Scale (mRS) was used to evaluate
three-month outcomes. A multivariate logistic regression model was used to
determine independent prognostic factors.
RESULTS: Among 145 consecutive patients with convulsive SE, 48 (33.1%) patents
eventually evolved into NCSE. Two patients with cerebral anoxia were exclude. At
three-month follow-up, 23 patients (50.0%) had mRS ≥ 3, and 16 (34.8%) died.
Thirty-two patients (69.6%) were given continuous intravenous anesthetic drugs
(CIVADs). Fourteen patients (30.4%) had CIVAD at the rate >50% proposed maximal
dose (PMD). There was a single predictor factor found significant after
multivariate logistic regression analysis: the recurrence of EEG seizures within
two hours of initiation of CIVAD at a dose of greater than half the proposed
maximal dose (OR, 9.63; 95%CI, 1.08-86.18; p = 0.043). The use of CIVAD, even
with a high dose (>50% PMD), was not independently associated with unfavorable
outcomes.
CONCLUSIONS: The recurrence of EEG seizures within two hours of initiation of
CIVAD at a dose of greater than half the proposed maximal dose predicts
unfavorable outcomes in NCSE after CSE. The refractoriness of the seizures might
be a significantly greater risk for poor outcome in NCSE after CSE than
treatment with CIVADs. PURPOSE: Rapid and correct diagnosis of nonconvulsive status epilepticus (NCSE)
is crucial for optimal treatment. However, electroencephalographic diagnosis can
be challenging. Salzburg Consensus Criteria (SCC) have been proposed to
facilitate correct diagnosis, but their validity needs to be further
established.
METHODS: We retrospectively reanalyzed the first EEG in adult patients (n = 284)
referred under the suspicion of NCSE at our institution in 2014. Nonconvulsive
status epilepticus or possible NCSE was diagnosed according to the SCC by an
examiner specifically trained in SCC and was compared with the original
diagnosis made by an expert EEG examiner, which in this context served as the
reference standard, to assess the validity of the criteria. Furthermore, the
clinical outcome for patients not diagnosed using SCC (false-negatives) was
examined.
RESULTS: Nonconvulsive status epilepticus or possible NCSE was diagnosed in 40
patients by the inexperienced reader using the SCC, blinded to other clinical
data, and in 47 patients by the experienced reader, not blinded to the clinical
data, who did not use SCC. There were eight false-negatives, one false-positive,
39 true-positives, and 236 true-negatives. Concordance between SCC and the
reference standard was high (k = 0.88 [95% confidence interval, 0.80 to 0.96]).
Four of the eight false-negatives suffered from anoxic encephalopathy. The
remainder had a history of epilepsy and returned to preictal functional state.
CONCLUSIONS: The SCC for NCSE implemented by an inexperienced EEG reader,
blinded to all other data, yielded results highly concordant with the evaluation
of EEG by an experienced reader. False-negative diagnoses were associated with
postictal states or anoxic encephalopathy. BACKGROUND: The diagnosis of nonconvulsive status epilepticus (NCSE) can pose a
challenge. Electroencephalogram (EEG) patterns can be difficult to interpret,
and the absence of an EEG correlate does not rule out the diagnosis of NCSE. In
this setting, neuroimaging tools to help in the diagnosis are crucial. Our aim
was to evaluate the role of 99mTc-hexamethyl propyleneamine oxime (HMPAO) single
photon emission computed tomography (SPECT) and quantitative HMPAO-SPECT
(QtSPECT) in patients with clinical suspicion of NCSE, and to evaluate their
value in the final diagnosis of NCSE.
METHODS: We recruited consecutive patients admitted in our center with suspicion
of NCSE, and selected those who underwent an HMPAO-SPECT. All patients were
admitted to the neurology ward and underwent an EEG. We divided the patients
into those who were finally with diagnosed NCSE (NCSE-p) and those who were not
(non-NCSE) according to the Salzburg Diagnostic EEG criteria. Sensitivity and
specificity of the diagnostic tools were calculated. The SPECTs were acquired in
a Skylight SPECT (Philips Healthcare, Amsterdam). The injections were done
during the clinical episode suspected of being an NCSE. The HMPAO-SPECT was
analyzed by two experts and was also quantified. All data were normalized to the
SPM SPECT template. We used an external healthy normal database to obtain a
Z-score map for each individual versus the normal database. The Z-score maximum
(Zmax) was extracted from each region of the AAL atlas as was the percentage of
voxels with a Z-score higher than 2.5 (N(%)). A logistic regression combining
the Zmax, N(%), and the effect of patient age was fitted to predict the final
NCSE diagnosis. A receiver operator characteristic (ROC) curve and the area
under the curve (AUC) were obtained to evaluate the classification performance.
RESULTS: We included 55 patients, 21 of them women (38.9%), with a median age of
62.1 years old (range 25-84). Thirty-six patients were with diagnosed NCSE
(62.9%). Initial EEG had a sensitivity of 61.1% and a specificity of 89%. Most
of the patients were critically ill with diagnostic difficulties, and it could
be one of the main reasons to find low sensitivity of the Salzburg diagnostic
EEG criteria. The Zmax and N(%) were significantly higher in NCSE-p than in
non-NCSE (p = 0.005 and p < 0.001, respectively). The HMPAO-SPECT qualitative
analysis had a sensitivity of 80.5% and specificity of 89.5% while QtSPECT had a
sensitivity of 82% and specificity of 81%.
CONCLUSION: Both 99mTc-HMPAO-SPECT and QtSPECT can be useful in the diagnosis of
NCSE. This article is part of the Special Issue "Proceedings of the 7th
London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures". |
List the components of the COMPASS complex | MLL4
MLL3
WDR5
RBBP5
ASH2
SET1 | Chronic inflammation underscores the pathogenesis of a range of human diseases.
Lipopolysaccharide (LPS) elicits strong pro-inflammatory responses in
macrophages through the transcription factor NF-κB. The epigenetic mechanism
underlying LPS-induced pro-inflammatory transcription is not fully understood.
Herein, we describe a role for myocardin-related transcription factor A (MRTF-A,
also known as MKL1) in this process. MRTF-A overexpression enhanced
NF-κB-dependent pro-inflammatory transcription, whereas MRTF-A silencing
inhibited this process. MRTF-A deficiency also reduced the synthesis of
pro-inflammatory mediators in a mouse model of colitis. LPS promoted the
recruitment of MRTF-A to the promoters of pro-inflammatory genes in an
NF-κB-dependent manner. Reciprocally, MRTF-A influenced the nuclear enrichment
and target binding of NF-κB. Mechanistically, MRTF-A was necessary for the
accumulation of active histone modifications on NF-κB target promoters by
communicating with the histone H3K4 methyltransferase complex (COMPASS).
Silencing of individual members of COMPASS, including ASH2, WDR5 and SET1 (also
known as SETD1A), downregulated the production of pro-inflammatory mediators and
impaired the NF-κB kinetics. In summary, our work has uncovered a previously
unknown function for MRTF-A and provided insights into the rationalized
development of anti-inflammatory therapeutic strategies. Histone modification plays important roles in many biological processes such as
development and carcinogenesis. Methylation of histone H3 lysine 4 (H3K4) is
commonly associated with transcriptional activation of genes. H3K4 methylation
in mammalian cells is carried out by COMPASS (complex of proteins associated
with Set1)-like complexes that are composed of catalytic subunits such as MLL1
(mixed-lineage leukaemia 1) and multiple regulatory subunits in which WDR5 (WD40
repeat-containing protein 5), RBBP5 (retinoblastoma-binding protein 5), ASH2
(absent, small or homoeotic discs 2) and DPY30 [constituting the WRAD
sub-complex (WDR5-ASH2-RBBP5-DPY30 complex)] are the major ones shared from
yeast to metazoans. We report, in the present paper, a new mode of spatial
regulation of H3K4 methyltransferase complexes. PAQR3 (progestin and adipoQ
receptors member 3), a tumour suppressor specifically localized in the Golgi
apparatus, negatively regulates H3K4 trimethylation (H3K4me3) in mammalian
cells. Consistently, HOXC8 and HOXA9 gene expression was negatively regulated by
PAQR3 expression levels. Hypoxia-induced H3K4me3 was augmented by PAQR3
knockdown and suppressed by PAQR3 overexpression in AGS gastric cancer cells.
PAQR3 was able to interact directly or indirectly with the four members of the
WRAD sub-complex and tether them to the Golgi apparatus, accompanied by
reduction in histone methyltransferase activity in the nucleus. PAQR3 also
interfered with the interaction of WDR5 with the C-terminus of MLL1 (C-ter).
Collectively, our study indicates that PAQR3 negatively modulates H3K4
methylation via altering the subcellular compartmentalization of the core
regulatory subunits of the COMPASS-like complexes in mammalian cells. Chromatin regulators control cellular differentiation by orchestrating dynamic
developmental gene expression programs, and hence, malfunctions in the
regulation of chromatin state contribute to both developmental disorders and
disease state. Mll4 (Kmt2d), a member of the COMPASS (COMplex of Proteins
ASsociated with Set1) protein family that implements histone H3 lysine 4
monomethylation (H3K4me1) at enhancers, is essential for embryonic development
and functions as a pancancer tumor suppressor. We define the roles of
Mll4/COMPASS and its catalytic activity in the maintece and exit of
ground-state pluripotency in murine embryonic stem cells (ESCs). Mll4 is
required for ESC to exit the naive pluripotent state; however, its intrinsic
catalytic activity is dispensable for this process. The depletion of the H3K4
demethylase Lsd1 (Kdm1a) restores the ability of Mll4 null ESCs to transition
from naive to primed pluripotency. Thus, we define an opposing regulatory axis,
wherein Lsd1 and associated co-repressors directly repress Mll4-activated gene
targets. This finding has broad reaching implications for human developmental
syndromes and the treatment of tumors carrying Mll4 mutations. The lysine methyltransferase KMT2C (also known as MLL3), a subunit of the
COMPASS complex, implements monomethylation of Lys4 on histone H3 (H3K4) at gene
enhancers. KMT2C (hereafter referred to as MLL3) frequently incurs point
mutations across a range of human tumor types, but precisely how these lesions
alter MLL3 function and contribute to oncogenesis is unclear. Here we report a
cancer mutational hotspot in MLL3 within the region encoding its plant
homeodomain (PHD) repeats and demonstrate that this domain mediates association
of MLL3 with the histone H2A deubiquitinase and tumor suppressor BAP1.
Cancer-associated mutations in the sequence encoding the MLL3 PHD repeats
disrupt the interaction between MLL3 and BAP1 and correlate with poor patient
survival. Cancer cells that had PHD-associated MLL3 mutations or lacked BAP1
showed reduced recruitment of MLL3 and the H3K27 demethylase KDM6A (also known
as UTX) to gene enhancers. As a result, inhibition of the H3K27
methyltransferase activity of the Polycomb repressive complex 2 (PRC2) in tumor
cells harboring BAP1 or MLL3 mutations restored normal gene expression patterns
and impaired cell proliferation in vivo. This study provides mechanistic insight
into the oncogenic effects of PHD-associated mutations in MLL3 and suggests that
restoration of a balanced state of Polycomb-COMPASS activity may have
therapeutic efficacy in tumors that bear mutations in the genes encoding these
epigenetic factors. |
Has the drug Afrezza been approved by the FDA? | Yes, Afrezza has been approved by the FDA. | The current review was designed to compare between the insulin inhalation
systems Exubera and Afrezza and to investigate the reasons why Exubera was
unsuccessful, when Afrezza maker is expecting their product to be felicitous. In
January 2006, Pfizer secured FDA and EC approval for the first of its kind,
regular insulin through Exubera inhaler device for the management of types 1 and
2 diabetes mellitus (DM) in adults. The product was no longer available to the
market after less than two years from its approval triggering a setback for
competitive new inhalable insulins that were already in various clinical
development phases. In contrary, MannKind Corporation started developing its
ultra-rapid-acting insulin Afrezza in a bold bid, probably by managing the
issues in which Exubera was not successful. Afrezza has been marketed since
February, 2015 by Sanofi after getting FDA approval in June 2014. The results
from this systematic review indicate the effectiveness of insulin inhalation
products, particularly for patients initiating insulin therapy. Pharmaceutical
companies should capitalize on the information available from insulin inhalation
to produce competitive products that are able to match the bioavailability of
subcutaneous (SC) insulin injection and to deal with the single insulin unit
increments and basal insulin requirements in some diabetic patients or extending
the horizon to inhalable drug products with completely different drug entities
for other indications. |
Central Vein Sign is characteristic to which disease? | Central vein sign on FLAIR* magnetic resonance imaging is highly specific and sensitive for multiple sclerosis. | BACKGROUND AND PURPOSE: Previous T2*-weighted magnetic resoce imaging (MRI)
studies have used white matter lesion (WML) central veins to distinguish
multiple sclerosis (MS) from its mimics. To be clinically applicable, the
"central vein sign" needs to be detectable across different T2* sequences. Our
objective was to determine if the central vein sign is reliably present in MS
and absent in patients with ischemic small vessel disease (SVD) across different
T2* sequences at 3T MRI.
METHODS: Ten patients with MS and 10 with SVD were each scanned on a 3 T Philips
and GE scanner. The MRI protocol included 3-dimensional (3D) T2* GRE, T2* with
high echo planar imaging (EPI) factor and susceptibility-weighted angiography
(SWAN). Total WML numbers, central vein numbers, and proportion of WMLs with
central veins were calculated using each sequence. Three blinded raters
identified a subset of six WMLs with central veins to diagnose MS or SVD.
RESULTS: Irrespective of the sequence, MS patients were identified based on a
higher proportion of WMLs with central veins. This proportion was dependent on
the T2* sequence used. T2* with high EPI allowed the highest median proportion
(69.6%) in MS patients; 6.1% in SVD patients (P < .0004). Rater reproducibility
varied depending on the T2* sequence used. T2* with high EPI produced good
agreement with the clinical diagnosis (Cohen's kappa range; .78-.89), as did
SWAN imaging with some raters; ĸ = .69.
CONCLUSIONS: The central vein sign can diagnose MS in the clinical setting of
modern 3T scanners. However, variations in the T2* sequences need to be
considered when defining a threshold for diagnosis. Author information:
(1)Translational Neuroradiology Section, National Institute of Neurological
Disorders and Stroke, NIH, 10 Center Drive MSC 1400, Building 10 Room 5C103,
Bethesda, Maryland, USA.
(2)St. Michael's Hospital, University of Toronto, Ontario, Canada.
(3)Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA.
(4)Department of Diagnostic Radiology, Yale University, New Haven, Connecticut,
USA.
(5)Division of Clinical Neuroscience, University of Nottingham, UK.
(6)Center for Neurological Imaging, Department of Radiology, Brigham and Women's
Hospital, Harvard Medical School, Boston, Massachusetts, USA.
(7)Department of Radiology and Biomedical Imaging, University of California, San
Francisco, California, USA.
(8)Department of Neurology, Massachusetts General Hospital, Harvard Medical
School, Boston, Massachusetts, USA.
(9)Center for Biomedical Imaging, Department of Radiology, Massachusetts General
Hospital, Harvard Medical School, Boston, Massachusetts, USA.
(10)Department of Neuroscience, Psychology, Drug Research and Child Health,
University of Florence, Italy.
(11)Multiple Sclerosis Research Group, Department of Neurology, University of
Texas Health Science Center at Houston, Texas, USA.
(12)Mellen Center for MS Treatment and Research, Cleveland Clinic Foundation,
Cleveland, Ohio, USA.
(13)Department of Pediatrics, Division of Neurology, UBC MRI Research Centre,
University of British Columbia, Vancouver, Canada.
(14)Advanced Imaging Research Center, Oregon Health &Science University,
Portland, Oregon, USA.
(15)Department of Biostatistics and Epidemiology, Perelman School of Medicine,
University of Pennsylvania, Philadelphia, Pennsylvania, USA.
(16)Department of Pathology, Stanford University School of Medicine, Stanford,
California, USA.
(17)Department of Neurological Sciences, University of Vermont College of
Medicine, Burlington, Vermont, USA.
(18)Medical Image Analysis Center, University Hospital Basel, Switzerland.
(19)Buffalo Neuroimaging Analysis Center, Department of Neurology, State
University of New York at Buffalo, New York, USA.
(20)Department of Neurology, Cedars-Sinai Medical Center, Los Angeles,
California, USA.
(21)Multiple Sclerosis Center, Department of Neurology, Keck School of Medicine
of the University of Southern California, Los Angeles, California, USA. Magnetic resoce imaging (MRI) is of paramount importance for the early
diagnosis of multiple sclerosis (MS) and MRI findings are part of the MS
diagnostic criteria. There is a growing interest in the use of ultra-high-field
strength -7 Tesla- (7T) MRI to investigate, in vivo, the pathological substrate
of the disease. Areas covered: An overview of 7T MRI applications in MS focusing
on increased sensitivity for lesion detection, specificity of the central vein
sign and better understanding of MS pathophysiology. Implications for disease
diagnosis, monitoring and treatment planning are discussed. Expert commentary:
7T MRI provides increased signal-to-noise and contrast-to-noise-ratio that allow
higher spatial resolution and better detection of anatomical and pathological
features. The high spatial resolution reachable at 7T has been a game changer
for neuroimaging applications not only in MS but also in epilepsy, brain tumors,
dementia, and neuro-psychiatric disorders. Furthermore, the first 7T device has
recently been cleared for clinical use by the food and drug administration. Author information:
(1)From the NMR Research Unit (R.C., L.M., C.T., F.D., M.C.Y., F.P., F.B.,
O.C.), Queen Square Multiple Sclerosis Centre, Department of Neuroinflammation,
UCL Institute of Neurology, University College London; NMO Clinical Service at
the Walton Centre (K.A.-A., A.J.), Liverpool; Translational Imaging Group (F.P.,
S.O., F.B.), Centre for Medical Image Computing (CMIC), Department of Medical
Physics and Bioengineering, University College London; Lysholm Department of
Neuroradiology (T.A.Y.), National Hospital for Neurology and Neurosurgery,
London, UK; Department of Radiology and Nuclear Medicine (F.B.), MS Centre
Amsterdam, VU Medical Centre Amsterdam, the Netherlands; and National Institute
for Health Research (NIHR) (T.A.Y., F.B., O.C.), University College London
Hospitals (UCLH) Biomedical Research Centre, London, UK. [email protected].
(2)From the NMR Research Unit (R.C., L.M., C.T., F.D., M.C.Y., F.P., F.B.,
O.C.), Queen Square Multiple Sclerosis Centre, Department of Neuroinflammation,
UCL Institute of Neurology, University College London; NMO Clinical Service at
the Walton Centre (K.A.-A., A.J.), Liverpool; Translational Imaging Group (F.P.,
S.O., F.B.), Centre for Medical Image Computing (CMIC), Department of Medical
Physics and Bioengineering, University College London; Lysholm Department of
Neuroradiology (T.A.Y.), National Hospital for Neurology and Neurosurgery,
London, UK; Department of Radiology and Nuclear Medicine (F.B.), MS Centre
Amsterdam, VU Medical Centre Amsterdam, the Netherlands; and National Institute
for Health Research (NIHR) (T.A.Y., F.B., O.C.), University College London
Hospitals (UCLH) Biomedical Research Centre, London, UK. 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 resoce images in patients with multiple sclerosis (MS) and cerebral
small vessel disease (CSVD). Materials and methods T2-weighted and
fluid-attenuated inversion recovery magnetic resoce 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
resoce 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. BACKGROUND AND PURPOSE: The central vein sign is a promising MR imaging
diagnostic biomarker for multiple sclerosis. Recent studies have demonstrated
that patients with MS have higher proportions of white matter lesions with the
central vein sign compared with those with diseases that mimic MS on MR imaging.
However, the clinical application of the central vein sign as a biomarker is
limited by interrater differences in the adjudication of the central vein sign
as well as the time burden required for the determination of the central vein
sign for each lesion in a patient's full MR imaging scan. In this study, we
present an automated technique for the detection of the central vein sign in
white matter lesions.
MATERIALS AND METHODS: Using multimodal MR imaging, the proposed method derives
a central vein sign probability, πij, for each lesion, as well as a
patient-level central vein sign biomarker, ψi. The method is probabilistic in
nature, allows site-specific lesion segmentation methods, and is potentially
robust to intersite variability. The proposed algorithm was tested on imaging
acquired at the University of Vermont in 16 participants who have MS and 15
participants who do not.
RESULTS: By means of the proposed automated technique, participants with MS were
found to have significantly higher values of ψ than those without MS (ψMS = 0.55
± 0.18; ψnon-MS = 0.31 ± 0.12; P < .001). The algorithm was also found to show
strong discriminative ability between patients with and without MS, with an area
under the curve of 0.88.
CONCLUSIONS: The current study presents the first fully automated method for
detecting the central vein sign in white matter lesions and demonstrates
promising performance in a sample of patients with and without MS. BACKGROUND: Misdiagnosis is common in multiple sclerosis (MS) as a proportion of
patients present with atypical clinical/magnetic resoce imaging (MRI)
findings. The central vein sign has the potential to be a non-invasive,
MS-specific biomarker.
OBJECTIVE: To test the accuracy of the central vein sign in predicting a
diagnosis of MS in patients with diagnostic uncertainty at disease presentation
using T2*-weighted, 3 T MRI.
METHODS: In this prospective pilot study, we recruited individuals with symptoms
unusual for MS but with brain MRI consistent with the disease, and those with a
typical clinical presentation of MS whose MRI did not suggest MS. We calculated
the proportion of lesions with central veins for each patient and compared the
results to the eventual clinical diagnoses. The optimal central vein threshold
for diagnosis was established.
RESULTS: Thirty-eight patients were scanned, 35 of whom have received a clinical
diagnosis. Median percentage of lesions with central veins was 51% in MS and 28%
in non-MS. A threshold of 40.7% lesions with central veins resulted in 100%
sensitivity and 73.9% specificity.
CONCLUSION: The central vein sign assessed with a clinically available T2* scan
can successfully diagnose MS in cases of diagnostic uncertainty. The central
vein sign should be considered as a diagnostic biomarker in MS. We aimed to evaluate the pooled incidence of central vein sign on T2*-weighted
images from patients with multiple sclerosis (MS), and to determine the
diagnostic performance of this central vein sign for differentiating MS from
other white matter lesions and provide an optimal cut-off value. A computerized
systematic search of the literature in PUBMED and EMBASE was conducted up to
December 14, 2018. Original articles investigating central vein sign on
T2*-weighted images of patients with MS were selected. The pooled incidence was
obtained using random-effects model. The pooled sensitivity and specificity were
obtained using a bivariate random-effects model. An optimal cut-off value for
the proportion of lesions with a central vein sign was calculated from those
studies providing individual patient data. Twenty-one eligible articles covering
501 patients with MS were included. The pooled incidence of central vein sign at
the level of individual lesion in patients with MS was 74% (95% CI, 65-82%). The
pooled sensitivity and pooled specificity for the diagnostic performance of the
central vein sign were 98% (95% CI, 92-100%) and 97% (95% CI, 91-99%),
respectively. The area under the HSROC curve was 1.00 (95% CI, 0.99-1.00). The
optimal cut-off value for the proportion of lesions with a central vein sign was
found to be 45%. Although various T2*-weighted images have been used across
studies, the current evidence supports the use of the central vein sign on
T2*-weighted images to differentiate MS from other white matter lesions. |
Which is the catalytic activity of the protein encoded by the gene KMT2C? | The lysine methyltransferase KMT2C (also known as MLL3), a subunit of the COMPASS complex, implements monomethylation of Lys4 on histone H3 (H3K4) at gene enhancers. | Circulating tumor cells (CTCs) are maligt cells released into the bloodstream
with the potential to form metastases in secondary sites. These cells, acquired
non-invasively, represent a sample of highly relevant tumor tissue that is an
alternative to difficult and low-yield tumor biopsies. In recent years, there
has been growing interest in genomic profiling of CTCs to enable longitudinal
monitoring of the tumor's adaptive response to therapy. However, due to their
extreme rarity, genotyping CTCs has proved challenging. Relevant mutations can
be masked by leukocyte contamination in isolates. Heterogeneity between
subpopulations of tumor cells poses an additional obstacle. Recent advances in
single-cell sequencing can overcome these limitations but isolation of single
CTCs is prone to cell loss and is prohibitively difficult and time consuming. To
address these limitations, we developed a single cell sample preparation and
genome sequencing pipeline that combines biophysical enrichment and single cell
isolation using laser capture microdissection (LCM). A key component of this
process is the encapsulation of enriched CTC sample in a hydrogel matrix, which
enhances the efficiency of single-cell isolation by LCM, and is compatible with
downstream sequencing. We validated this process by sequencing of single CTCs
and cell free DNA (cfDNA) from a single patient with castration resistant
prostate cancer. Identical mutations were observed in prostate cancer driver
genes (TP53, PTEN, FOXA1) in both single CTCs and cfDNA. However, two
independently isolated CTCs also had identical missense mutations in the genes
for ATR serine/threonine kinase, KMT2C histone methyltransferase, and FANCC DNA
damage repair gene. These mutations may be missed by bulk sequencing libraries,
whereas single cell sequencing could potentially enable the characterization of
key CTC subpopulations that arise during metastasis. The lysine methyltransferase KMT2C (also known as MLL3), a subunit of the
COMPASS complex, implements monomethylation of Lys4 on histone H3 (H3K4) at gene
enhancers. KMT2C (hereafter referred to as MLL3) frequently incurs point
mutations across a range of human tumor types, but precisely how these lesions
alter MLL3 function and contribute to oncogenesis is unclear. Here we report a
cancer mutational hotspot in MLL3 within the region encoding its plant
homeodomain (PHD) repeats and demonstrate that this domain mediates association
of MLL3 with the histone H2A deubiquitinase and tumor suppressor BAP1.
Cancer-associated mutations in the sequence encoding the MLL3 PHD repeats
disrupt the interaction between MLL3 and BAP1 and correlate with poor patient
survival. Cancer cells that had PHD-associated MLL3 mutations or lacked BAP1
showed reduced recruitment of MLL3 and the H3K27 demethylase KDM6A (also known
as UTX) to gene enhancers. As a result, inhibition of the H3K27
methyltransferase activity of the Polycomb repressive complex 2 (PRC2) in tumor
cells harboring BAP1 or MLL3 mutations restored normal gene expression patterns
and impaired cell proliferation in vivo. This study provides mechanistic insight
into the oncogenic effects of PHD-associated mutations in MLL3 and suggests that
restoration of a balanced state of Polycomb-COMPASS activity may have
therapeutic efficacy in tumors that bear mutations in the genes encoding these
epigenetic factors. |
Which is the most mutated gene in dilated cardiomyopathy (DCM)? | The LMNA gene is the most mutated gene in dilated cardiomyopathy (DCM) and affects approximately 25% of the patients. | A major advance in the study of the pathogenesis of dilated cardiomyopathy (DC)
has been the identification of a familial trait in a relevant proportion of
cases (more than 25%), which indicates that, at least in these cases, a mutated
gene is the cause of the disease. Familial dilated cardiomyopathy is a
genetically heterogeneous disorder, most frequently with autosomal-domit
inheritance. Five different loci that cosegregate with the disease have been
mapped so far; the identification of the disease genes is still in progress. The
only disease gene known so far is the dystrophin gene, which causes X-linked DC.
By analogy with dystrophin, it is believed that other cytoskeletal proteins
could be involved in the pathogenesis of DC. Finally, in right ventricular
cardiomyopathy, a peculiar form of cardiomyopathy that is frequently familial as
well, several disease loci have been described. Also in this case, no disease
gene has been yet identified. The advances in clinical and molecular genetics of
DC have relevant clinical and therapeutic implications. OBJECTIVE: To examine the function of the novel mutation E82K in LMNA gene
identified in a Chinese family infected by dilated cardiomyopathy.
METHODS: (1) One Chinese family infected by dilated cardiomyopathy was chosen
for the study. Exons 1-12 of the LMNA gene were screened with both PCR method
and the cycle sequencing of the PCR products. (2) cDNA of the E82K mutation or
wild type of LMNA gene was transfected into HEK293 cells and the apoptosis of
the cells was detected after treatment with 0.8 mmol/L H2O2.
RESULTS: (1) A new mutation E82K in LMNA gene was identified in this dilated
cardiomyopathy family. (2) Apoptosis was more in the HEK293 cells transfected
with E82K mutation than those with empty vector or wild type LMNA gene.
CONCLUSIONS: The missense mutation E82K in LMNA gene changed the polar of the
amino acid. It showed a maligt phenotype of severe clinical symptoms, early
onset, poor survival prognosis and might be associated with atrioventricular
conduction block (II degrees-III degrees), suggesting that the E82K mutation in
LMNA gene may be a candidate for nosogenesis of dilated cardiomyopathy. OBJECTIVE: To investigate the effect of a novel LMNA gene mutation E82K found in
a Chinese family with dilated cardiomyopathy on cell cycle of HEK293 cells.
METHODS: (1) Human wild type full-length LMNA gene cDNA was subcloned into
eukaryotic expression vector pTracer-CMV and point mutation was introduced into
the cDNA. LMNA gene wild type and mutant E82K LMNA gene were transfected into
HEK293 cells respectively and stable cell lines resistant to antibiotic were
obtained 4 weeks later. (2) Cell cycle changes were analyzed by flow cytometry
in HEK293 cells transfected with wild type and mutant E82K LMNA gene and empty
vector in the presence of 0.8 mmol/L H(2)O(2).
RESULTS: Cell circle was arrested at G0/G1 phase in the cells transfected with
mutated E82K LMNA gene and at G2/M phase in other cell groups in the presence of
H(2)O(2).
CONCLUSION: Cell circle was arrested at G0/G1 phase in the cells transfected
with E82K LMNA gene in the presence of H(2)O(2) in HEK293 cells. BACKGROUND: Mutations in the lamin A/C gene (LMNA) may cause familial dilated
cardiomyopathy (dilated cardiomyopathy) characterized by early onset
atrio-ventricular block (A-V block) before the manifestation of dilated
cardiomyopathy and high risk of sudden death due to ventricular arrhythmia,
which is very similar to the phenotype of gap junction related heart disease.
This study aimed to determine the expression and localization of connexins in
neonatal myocytes transfected with wild-type (WT) or mutant LMNA to elucidate
how these mutations cause heart diseases.
METHODS: We studied the connexin 43 (Cx43) and connexin 40 (Cx40) expression in
cultured neonatal myocytes transfected with wild-type (WT) or mutant LMNA
(Glu82Lys (E82K) and Arg644Cys (R644C)) using confocal imaging and Western
blotting analysis.
RESULTS: Cx43 protein expression was reduced by 40% in cells transfected with
LMNA E82K than that in cells transfected with WT LMNA cDNA. Confocal imaging
showed that the Cx43 located inside the cells by LMNA E82K. By contrast, LMNA
E82K mutation had no effect on expression and localization of Cx40. LMNA R644C
transfection did not show any significant effects on gap junctions at all.
CONCLUSIONS: Our findings suggest that LMNA E82K significantly reduced the Cx43
expression and altered its localization which may be one of the pathological
mechanisms underlying LMNA-related heart disease. BACKGROUND: The purpose of this study was to identify early features of lamin
A/C gene mutation related dilated cardiomyopathy (DCM) with cardiovascular
magnetic resoce (CMR). We characterise myocardial and functional findings in
carriers of lamin A/C mutation to facilitate the recognition of these patients
using this method. We also investigated the connection between myocardial
fibrosis and conduction abnormalities.
METHODS: Seventeen lamin A/C mutation carriers underwent CMR. Late gadolinium
enhancement (LGE) and cine images were performed to evaluate myocardial
fibrosis, regional wall motion, longitudinal myocardial function, global
function and volumetry of both ventricles. The location, pattern and extent of
enhancement in the left ventricle (LV) myocardium were visually estimated.
RESULTS: Patients had LV myocardial fibrosis in 88% of cases. Segmental wall
motion abnormalities correlated strongly with the degree of enhancement.
Myocardial enhancement was associated with conduction abnormalities. Sixty-nine
percent of our asymptomatic or mildly symptomatic patients showed mild
ventricular dilatation, systolic failure or both in global ventricular analysis.
Decreased longitudinal systolic LV function was observed in 53% of patients.
CONCLUSIONS: Cardiac conduction abnormalities, mildly dilated LV and depressed
systolic dysfunction are common in DCM caused by a lamin A/C gene mutation.
However, other cardiac diseases may produce similar symptoms. CMR is an accurate
tool to determine the typical cardiac involvement in lamin A/C cardiomyopathy
and may help to initiate early treatment in this maligt familiar form of DCM. Author information:
(1)Department of Cardiology, CUB Hôpital Erasme, Université Libre de Bruxelles,
Brussels, Belgium.
(2)Centre for Inherited Cardiovascular Diseases, IRCCS Foundation, University
Hospital Policlinico San Matteo, Pavia, Italy.
(3)Department of Translational Medical Sciences, Federico II University, Naples,
Italy.
(4)Department of Cardiology, Maastricht University Medical Center & CARIM,
Maastricht University, Maastricht, The Netherlands.
(5)School of Medicine, Surgery and Dentistry, University of Salerno, Salerno,
Italy.
(6)School of Medicine and Dentistry, University of Aberdeen, Aberdeen, UK.
(7)Department of Systems Physiology, Ruhr University Bochum, Bochum, Germany.
(8)Molecular Cardiology, Department of Cardiology and Angiology, Hannover
Medical School, Hannover, Germany.
(9)Department of Cardiology, Heidelberg University, Heidelberg, Germany.
(10)Department of Genetics, Stanford University School of Medicine, Genome
Technology Center, Palo Alto, CA, USA.
(11)Cardiovascular R&D Unit, Department of Surgery and Physiology, Faculty of
Medicine, University of Porto, Porto, Portugal.
(12)Department of Cardiothoracic Surgery, Hospital of S. João, Porto, Portugal.
(13)Institute of Molecular and Translational Therapeutic Strategies, Hannover
Medical School, Hannover, Germany.
(14)Department of Physiology, VU University Medical Centre, Amsterdam
Cardiovascular Sciences, Amsterdam, The Netherlands.
(15)Netherlands Heart Institute, Utrecht, The Netherlands.
(16)Cardiovascular Research Center, Royal Brompton and Harefield NHS Foundation
Trust and Imperial College London, London, UK.
(17)Department of Cardiovascular Sciences, Leuven University, Leuven, Belgium. The link between the cytoplasmic desmin intermediate filaments and those of
nuclear lamins serves as a major integrator point for the intracellular
communication between the nucleus and the cytoplasm in cardiac muscle. We
investigated the involvement of desmin in the cardiomyopathy caused by the lamin
A/C gene mutation using the LmnaH222P/H222P mouse model of the disease. We
demonstrate that in these mouse hearts desmin loses its normal Z disk and
intercalated disc localization and presents aggregate formation along with
mislocalization of basic intercalated disc protein components, as well as severe
structural abnormalities of the intercalated discs and mitochondria. To address
the extent by which the observed desmin network defects contribute to the
progression of LmnaH222P/H222P cardiomyopathy, we investigated the consequences
of desmin-targeted approaches for the disease treatment. We showed that
cardiac-specific overexpression of the small heat shock protein αΒ-Crystallin
confers cardioprotection in LmnaH222P/H222P mice by ameliorating desmin network
defects and by attenuating the desmin-dependent mislocalization of basic
intercalated disc protein components. In addition, αΒ-Crystallin overexpression
rescues the intercalated disc, mitochondrial and nuclear defects of
LmnaH222P/H222P hearts, as well as the abnormal activation of ERK1/2. Consistent
with that, by generating the LmnaH222P/H222PDes+/- mice, we showed that the
genetically decreased endogenous desmin levels have cardioprotective effects in
LmnaH222P/H222P hearts since less desmin is available to form dysfunctional
aggregates. In conclusion, our results demonstrate that desmin network
disruption, disorganization of intercalated discs and mitochondrial defects are
a major mechanism contributing to the progression of this LMNA cardiomyopathy
and can be ameliorated by αΒ-Crystallin overexpression. |
List psychiatric diseases that are associated with Synaptosome Associated Protein 25 (snap25). | attention-deficit/hyperactivity disorder
bipolar
schizophrenia | SNAP-25 is a key component of the synaptic-vesicle fusion machinery, involved in
several psychiatric diseases including schizophrenia and ADHD. SNAP-25 protein
expression is lower in different brain areas of schizophrenic patients and in
ADHD mouse models. How the reduced expression of SNAP-25 alters the properties
of synaptic transmission, leading to a pathological phenotype, is unknown. We
show that, unexpectedly, halved SNAP-25 levels at 13-14 DIV not only fail to
impair synaptic transmission but instead enhance evoked glutamatergic
neurotransmission. This effect is possibly dependent on presynaptic
voltage-gated calcium channel activity and is not accompanied by changes in
spontaneous quantal events or in the pool of readily releasable synaptic
vesicles. Notably, synapses of 13-14 DIV neurons with reduced SNAP-25 expression
show paired-pulse depression as opposed to paired-pulse facilitation occurring
in their wild-type counterparts. This phenotype disappears with synapse
maturation. As alterations in short-term plasticity represent a new mechanism
contributing to cognitive impairments in intellectual disabilities, our data
provide mechanistic clues for neuronal circuit alterations in psychiatric
diseases characterized by reduced expression of SNAP-25. Impulsivity is a personality trait of high impact and is connected with several
types of maladaptive behavior and psychiatric diseases, such as attention
deficit hyperactivity disorder, alcohol and drug abuse, as well as pathological
gambling and mood disorders. Polymorphic variants of the SNAP-25 gene emerged as
putative genetic components of impulsivity, as SNAP-25 protein plays an
important role in the central nervous system, and its SNPs are associated with
several psychiatric disorders. In this study we aimed to investigate if
polymorphisms in the regulatory regions of the SNAP-25 gene are in association
with normal variability of impulsivity. Genotypes and haplotypes of two
polymorphisms in the promoter (rs6077690 and rs6039769) and two SNPs in the 3'
UTR (rs3746544 and rs1051312) of the SNAP-25 gene were determined in a healthy
Hungarian population (N = 901) using PCR-RFLP or real-time PCR in combination
with sequence specific probes. Significant association was found between the T-T
3' UTR haplotype and impulsivity, whereas no association could be detected with
genotypes or haplotypes of the promoter loci. According to sequence alignment,
the polymorphisms in the 3' UTR of the gene alter the binding site of
microRNA-641, which was analyzed by luciferase reporter system. It was observed
that haplotypes altering one or two nucleotides in the binding site of the seed
region of microRNA-641 significantly increased the amount of generated protein
in vitro. These findings support the role of polymorphic SNAP-25 variants both
at psychogenetic and molecular biological levels. Collapsin response mediator protein 2 (CRMP2) plays a key role in axon guidance,
dendritic morphogenesis and cell polarization. CRMP2 is implicated in various
neurological and psychiatric disorders. However, in vivo functions of CRMP2
remain unknown. We generated CRMP2 gene-deficient (crmp2-/- ) mice and examined
their behavioral phenotypes. During 24-h home cage monitoring, the activity
level during the dark phase of crmp2-/- mice was significantly higher than that
of wild-type (WT) mice. Moreover, the time during the open arm of an elevated
plus maze was longer for crmp2-/- mice than for WT mice. The duration of social
interaction was shorter for crmp2-/- mice than for WT mice. Crmp2-/- mice also
showed mild impaired contextual learning. We then examined the
methamphetamine-induced behavioral change of crmp2-/- mice. Crmp2-/- mice showed
increased methamphetamine-induced ambulatory activity and serotonin release.
Crmp2-/- mice also showed altered expression of proteins involved in GABAergic
synapse, glutamatergic synapse and neurotrophin signaling pathways. In addition,
SNAP25, RAB18, FABP5, ARF5 and LDHA, which are related genes to schizophrenia
and methamphetamine sensitization, are also decreased in crmp2-/- mice. Our
study implies that dysregulation of CRMP2 may be involved in pathophysiology of
neuropsychiatric disorders. |
Which type of cells protect Haematopoietic stem and progenitor cells (HSPCs) from ultraviolet-light-induced DNA damage in aquatic vertebrates? | Haematopoietic stem and progenitor cells (HSPCs) require a specific microenvironment to grow and are protected from ultraviolet-light-induced DNA damages by melanocytes. Mutations that lack melanocytes have normal steady-state haem atopoiesis under standard laboratory conditions while melanocytes above the stem cell niche protect HSPCs against ultraviolet- light-induced damage. | Author information:
(1)Department of Stem Cell and Regenerative Biology and Harvard Stem Cell
Institute, Harvard University, Cambridge, MA, USA.
(2)Stem Cell Program and Division of Hematology/Oncology, Boston Children's
Hospital and Dana Farber Cancer Institute, Howard Hughes Medical Institute,
Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA.
(3)Department of Pediatric Hematology and Oncology, Center for Pediatrics,
Medical Center-University of Freiburg, Faculty of Medicine, University of
Freiburg, Freiburg, Germany.
(4)Division of Hematology, Department of Medicine, Brigham and Women's Hospital,
Harvard Medical School, Boston, MA, USA.
(5)US Fish and Wildlife Service, Private John Allen National Fish Hatchery,
Tupelo, MS, USA.
(6)Department of Biology, Stanford University, Stanford, CA, USA.
(7)US Geological Survey, Great Lakes Science Center, Hammond Bay Biological
Station, Millersburg, MI, USA.
(8)Molecular Cell Biology, University of California, Merced, CA, USA.
(9)Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard
Medical School, Charlestown, MA, USA.
(10)Department of Dermatology, Medical Center-University of Freiburg, Faculty of
Medicine, University of Freiburg, Freiburg, Germany.
(11)Department of Cellular and Molecular Immunology, Max Planck Institute of
Immunobiology and Epigenetics, Freiburg, Germany.
(12)Developmental Biology, Faculty of Biology, Centre for Biological Signalling
Studies (BIOSS), Albert-Ludwigs-University of Freiburg, Freiburg, Germany.
(13)Department of Stem Cell and Regenerative Biology and Harvard Stem Cell
Institute, Harvard University, Cambridge, MA, USA. [email protected].
(14)Stem Cell Program and Division of Hematology/Oncology, Boston Children's
Hospital and Dana Farber Cancer Institute, Howard Hughes Medical Institute,
Harvard Stem Cell Institute, Harvard Medical School, Boston, MA, USA.
[email protected]. |
Which is the primary interacting protein of BLK? | The B cell adaptor protein with ankyrin repeats (BANK1) and the B lymphoid tyrosine kinase (BLK) have been genetically associated with autoimmunity. The proteins of these genes interact physically and work in concert during B-cell signaling. | OBJECTIVES: Altered signalling in B cells is a predomit feature of systemic
lupus erythematosus (SLE). The genes BANK1 and BLK were recently described as
associated with SLE. BANK1 codes for a B-cell-specific cytoplasmic protein
involved in B-cell receptor signalling and BLK codes for an Src tyrosine kinase
with important roles in B-cell development. To characterise the role of BANK1
and BLK in SLE, a genetic interaction analysis was performed hypothesising that
genetic interactions could reveal functional pathways relevant to disease
pathogenesis.
METHODS: The GPAT16 method was used to analyse the gene-gene interactions of
BANK1 and BLK. Confocal microscopy was used to investigate co-localisation, and
immunoprecipitation was used to verify the physical interaction of BANK1 and
BLK.
RESULTS: Epistatic interactions between BANK1 and BLK polymorphisms associated
with SLE were observed in a discovery set of 279 patients and 515 controls from
northern Europe. A meta-analysis with 4399 European individuals confirmed the
genetic interactions between BANK1 and BLK. As BANK1 was identified as a binding
partner of the Src tyrosine kinase LYN, the possibility that BANK1 and BLK could
also show a protein-protein interaction was tested. The co-immunoprecipitation
and co-localisation of BLK and BANK1 were demonstrated. In a Daudi cell line and
primary naive B cells endogenous binding was enhanced upon B-cell receptor
stimulation using anti-IgM antibodies.
CONCLUSION: This study shows a genetic interaction between BANK1 and BLK, and
demonstrates that these molecules interact physically. The results have
important consequences for the understanding of SLE and other autoimmune
diseases and identify a potential new signalling pathway. BACKGROUND: BANK1 and BLK belong to the pleiotropic autoimmune genes; recently,
epistasis between BANK1 and BLK was detected in systemic lupus erythematosus.
Although BLK has been reproducibly identified as a risk factor in rheumatoid
arthritis (RA), reports are conflicting about the contribution of BANK1 to RA
susceptibility. To ascertain the real impact of BANK1 on RA genetic
susceptibility, we performed a large meta-analysis including our original data
and tested for an epistatic interaction between BANK1 and BLK in RA
susceptibility.
PATIENTS AND METHODS: We investigated data for 1,915 RA patients and 1,915
ethnically matched healthy controls genotyped for BANK1 rs10516487 and rs3733197
and BLK rs13277113. The association of each SNP and RA was tested by logistic
regression. Multivariate analysis was then used with an interaction term to test
for an epistatic interaction between the SNPs in the 2 genes.
RESULTS: None of the SNPs tested individually was significantly associated with
RA in the genotyped samples. However, we detected an epistatic interaction
between BANK1 rs3733197 and BLK rs13277113 (P(interaction) = 0.037). In
individuals carrying the BLK rs13277113 GG genotype, presence of the BANK1
rs3733197 G allele increased the risk of RA (odds ratio 1.21 [95% confidence
interval 1.04-1.41], P = 0.015. Combining our results with those of all other
studies in a large trans-ethnic meta-analysis revealed an association of the
BANK1 rs3733197 G allele and RA (1.11 [1.02-1.21], P = 0.012).
CONCLUSION: This study confirms BANK1 as an RA susceptibility gene and for the
first time provides evidence for epistasis between BANK1 and BLK in RA. Our
results illustrate the concept of pleiotropic epistatic interaction, suggesting
that BANK1 and BLK might play a role in RA pathogenesis. AIM: Autophagy-related gene 5 (ATG5), ATG7, B-lymphoid tyrosine kinase (BLK) and
B-cell scaffold protein with ankyrin repeats 1 (BANK1) are involved in B-cell
signaling; several genome-wide association studies detected these genes as
candidates involved in systemic lupus erythematosus (SLE). We aimed to replicate
the association of these genes with SLE in Chinese Han and to search for
possible gene-gene interactions.
METHODS: TaqMan single-nucleotide polymorphism (SNP) genotyping was used to
detect rs548234, rs665791 in ATG5, rs11706903 in ATG7, rs2736340 in BLK and
rs10516487 in BANK1 in 382 SLE patients and 660 healthy controls. The epistasis
effect was analyzed by logistic regression, multifactor dimensionality reduction
(MDR) and linear regression analysis.
RESULTS: SLE was associated with frequency of rs548234 (P = 0.010; odds ratio
[OR] = 1.298), rs2736340 (P = 2.47 × 10-5 ; OR = 1.574) and rs10516487 (P =
0.002; OR = 0.642). Although no epistasis effects were found among three
autophagy-related gene loci or with rs2736340 and rs10516487, BLK and BANK1 had
the closest interaction effect on logistic regression analysis (P = 0.013; OR =
1.205), MDR (P < 0.0001), and linear regression analysis (P = 0.0017; R2 =
0.1806). The risk genotype TT of rs2736340 was associated with decreased
messenger RNA level of BLK; BLK transcript level was lower in SLE patients than
healthy controls.
CONCLUSION: We confirmed the association of rs548234, rs2736340 and rs10516487
with SLE in Chinese Han and reinforced our hypothesis of their epistasis effect
in regulating B-cell signaling in SLE. |
Is Protoporphyrinogen oxidase localized to the mitochondrium? | Yes,
Mitochondrial targeting of human protoporphyrinogen oxidase. | Earlier studies in this laboratory had shown that the malarial parasite can
synthesize heme de novo and inhibition of the pathway leads to death of the
parasite. It has been proposed that the pathway for the biosynthesis of heme in
Plasmodium falciparum is unique involving three different cellular compartments,
namely mitochondrion, apicoplast and cytosol. Experimental evidences are now
available for the functionality and localization of all the enzymes of this
pathway, except protoporphyrinogen IX oxidase (PfPPO), the penultimate enzyme.
In the present study, PfPPO has been cloned, expressed and shown to be localized
to the mitochondrion by immunofluorescence microscopy. Interestingly, the enzyme
has been found to be active only under anaerobic conditions and is dependent on
electron transport chain (ETC) acceptors for its activity. The native enzyme
present in the parasite is inhibited by the ETC inhibitors, atovaquone and
antimycin. Atovaquone, a well known inhibitor of parasite dihydroorotate
dehydrogenase, dependent on the ETC, inhibits synthesis of heme as well in P.
falciparum culture. A model is proposed to explain the ETC dependence of both
the pyrimidine and heme-biosynthetic pathways in P. falciparum. |
How many doses of vaxchora are required? | Vaxchora is a single-dose vaccine. | OBJECTIVE: To review trials evaluating the efficacy and safety of Vaxchora, a
reformulated, single-dose, oral, lyophilized Vibrio cholerae CVD 103-HgR vaccine
for the prevention of travel-related cholera caused by V cholerae serogroup O1.
DATA SOURCES: A literature search was conducted using MEDLINE (1946 to January
week 3, 2017) and EMBASE (1996 to 2017 week 3). Keywords included oral cholera
vaccine, single-dose, Vaxchora, and CVD 103-HgR. Limits included human, clinical
trials published in English since 2010. ClinicalTrials.gov was used as a source
for unpublished data. Additional data sources were obtained through
bibliographic review of selected articles.
STUDY SELECTION AND DATA EXTRACTION: Studies that addressed the safety and
efficacy of Vaxchora, the reformulated, single-dose oral CVD 103-HgR cholera
vaccine, were selected for analysis.
DATA SYNTHESIS: Approval of Vaxchora, was based on efficacy of the vaccine in
human trials demonstrating 90.3% protection among those challenged with V
cholerae 10 days after vaccination and in immunogenicity studies with 90%
systemic vibriocidal antibody conversion at 6 months after a single-dose of
vaccine. Tolerability was acceptable, with the most common adverse effects
reported to be fatigue, headache, and abdominal pain.
CONCLUSION: Vaxchora is the only FDA-approved, single-dose oral vaccine for the
prevention of cholera caused by V cholerae serogroup O1 in adult travelers from
the United States going to cholera-affected areas. Safety and efficacy has not
been established in children, immunocompromised persons, and pregt or
breastfeeding women or those living in cholera-endemic areas. |
What is the SLC25A20 protein transporting? | The carnitine/acylcarnitine transporter (CACT; SLC25A20) mediates an antiport reaction allowing entry of acyl moieties in the form of acylcarnitines into the mitochondrial matrix and exit of free carnitine. | The carnitine/acylcarnitine transporter (CACT; SLC25A20) mediates an antiport
reaction allowing entry of acyl moieties in the form of acylcarnitines into the
mitochondrial matrix and exit of free carnitine. The transport function of CACT
is crucial for the β-oxidation pathway. In this work, it has been found that
CACT is partially acetylated in rat liver mitochondria as demonstrated by
anti-acetyl-lys antibody immunostaining. Acetylation was reversed by the
deacetylase Sirtuin 3 in the presence of NAD+. After treatment of the
mitochondrial extract with the deacetylase, the CACT activity, assayed in
proteoliposomes, increased. The half-saturation constant of the CACT was not
influenced, while the V max was increased by deacetylation. Sirtuin 3 was not
able to deacetylate the CACT when incubation was performed in intact mitoplasts,
indicating that the acetylation sites are located in the mitochondrial matrix.
Prediction on the localization of acetylated residues by bioinformatics
correlates well with the experimental data. Recombit CACT treated with
acetyl-CoA was partially acetylated by non-enzymatic mechanism with a
corresponding decrease of transport activity. The experimental data indicate
that acetylation of CACT inhibits its transport activity, and thus may
contribute to the regulation of the mitochondrial β-oxidation pathway. The diterpenoid ester ingenol mebutate (IngMeb) is the active ingredient in the
topical drug Picato, a first-in-class treatment for the precancerous skin
condition actinic keratosis. IngMeb is proposed to exert its therapeutic effects
through a dual mode of action involving (i) induction of cell death that is
associated with mitochondrial dysfunction followed by (ii) stimulation of a
local inflammatory response, at least partially driven by protein kinase C (PKC)
activation. Although this therapeutic model has been well characterized, the
complete set of molecular targets responsible for mediating IngMeb activity
remains ill-defined. Here, we have synthesized a photoreactive, clickable
analogue of IngMeb and used this probe in quantitative proteomic experiments to
map several protein targets of IngMeb in human cancer cell lines and primary
human keratinocytes. Prominent among these targets was the mitochondrial
carnitine-acylcarnitine translocase SLC25A20, which we show is inhibited in
cells by IngMeb and the more stable analogue ingenol disoxate (IngDsx), but not
by the canonical PKC agonist 12-O-tetradecanoylphorbol-13-acetate (TPA).
SLC25A20 blockade by IngMeb and IngDsx leads to a buildup of cellular
acylcarnitines and blockade of fatty acid oxidation (FAO), pointing to a
possible mechanism for IngMeb-mediated perturbations in mitochondrial function. Cardiac metabolism is highly adaptive in response to changes in substrate
availability, as occur during fasting. This metabolic flexibility is essential
to the maintece of contractile function and is under the control of a group
of select transcriptional regulators, notably the nuclear receptor family of
factors member PPARα. However, the diversity of physiologic and pathologic
states through which the heart must sustain function suggests the possible
existence of additional transcriptional regulators that play a role in matching
cardiac metabolism to energetic demand. Here we show that cardiac KLF15 is
required for the normal cardiac response to fasting. Specifically, we find that
cardiac function is impaired upon fasting in systemic and cardiac specific
Klf15-null mice. Further, cardiac specific Klf15-null mice display a
fasting-dependent accumulation of long chain acylcarnitine species along with a
decrease in expression of the carnitine translocase Slc25a20. Treatment with a
diet high in short chain fatty acids relieves the KLF15-dependent long chain
acylcarnitine accumulation and impaired cardiac function in response to fasting.
Our observations establish KLF15 as a critical mediator of the cardiac adaptive
response to fasting through its regulation of myocardial lipid utilization. |
List the vaccine strains contained in Fluvirin. | Fluvirin contains 18 mg of haemagglutinin per H1N1 vaccine strain, 17 mg of haemagglutinin per H3N2 vaccine strain, and 15 mg of haemagglutinin per B vaccine strain. | |
Do de novo truncating mutations in WASF1 cause cancer? | No, de novo heterozygous mutations in WASF1 cause a rare form of intellectual disability. | Collaborators: Aitman T, Bennett D, Caulfield M, Chinnery P, Gale D, Koziell A,
Kuijpers TW, Laffan MA, Maher E, Markus HS, Morrell NW, Ouwehand WH, Perry DJ,
Raymond FL, Roberts I, Smith KGC, Thrasher A, Watkins H, Williamson C, Woods G,
Ashford S, Bradley JR, Fletcher D, Hammerton T, James R, Kingston N, Penkett CJ,
Stirrups K, Veltman M, Young T, Brown M, Clements-Brod N, Davis J, Dewhurst E,
Dolling H, Erwood M, Frary A, Linger R, Martin JM, Papadia S, Rehnstrom K, Stark
H, Allsup D, Austin S, Bakchoul T, Bariana TK, Bolton-Maggs P, Chalmers E,
Collins J, Collins P, Erber WN, Everington T, Favier R, Freson K, Furie B,
Gattens M, Gebhart J, Gomez K, Greene D, Greinacher A, Gresele P, Hart D,
Heemskerk JWM, Henskens Y, Kazmi R, Keeling D, Kelly AM, Lambert MP, Lentaigne
C, Liesner R, Makris M, Mangles S, Mathias M, Millar CM, Mumford A, Nurden P,
Payne J, Pasi J, Peerlinck K, Revel-Vilk S, Richards M, Rondina M, Roughley C,
Schulman S, Schulze H, Scully M, Sivapalaratnam S, Stubbs M, Tait RC, Talks K,
Thachil J, Toh CH, Turro E, Van Geet C, De Vries M, Warner TQ, Watson H,
Westbury S, Furnell A, Mapeta R, Rayner-Matthews P, Simeoni I, Staines S,
Stephens J, Watt C, Whitehorn D, Attwood A, Daugherty L, Deevi SVV, Halmagyi C,
Hu F, Matser V, Meacham S, Megy K, Shamardina O, Titterton C, Tuna S, Yu P, von
Ziegenweldt J, Astle W, Bleda M, Carss KJ, Gräf S, Haimel M, Lango-Allen H,
Richardson S, Calleja P, Rankin S, Turek W, Anderson J, Bryson C, Carmichael J,
McJannet C, Stock S, Allen L, Ambegaonkar G, Armstrong R, Arno G,
Bitner-Glindzicz M, Brady A, Canham N, Chitre M, Clement E, Clowes V, Deegan P,
Deshpande C, Doffinger R, Firth H, Flinter F, French C, Gardham A, Ghali N,
Gissen P, Grozeva D, Henderson R, Hensiek A, Holden S, Holder M, Holder S, Hurst
J, Josifova D, Krishnakumar D, Kurian MA, Lees M, MacLaren R, Maw A, Mehta S,
Michaelides M, Moore A, Murphy E, Park SM, Parker A, Patch C, Paterson J, Rankin
J, Reid E, Rosser E, Sanchis-Juan A, Sandford R, Santra S, Scott R, Sohal A,
Stein P, Thomas E, Thompson D, Tischkowitz M, Vogt J, Wakeling E, Wassmer E,
Webster A, Ali S, Ali S, Boggard HJ, Church C, Coghlan G, Cookson V, Corris PA,
Creaser-Myers A, DaCosta R, Dormand N, Eyries M, Gall H, Ghataorhe PK, Ghio S,
Ghofrani A, Gibbs JSR, Girerd B, Greenhalgh A, Hadinnapola C, Houweling AC,
Humbert M, In't Veld AH, Kennedy F, Kiely DG, Kovacs G, Lawrie A, Ross RVM,
Machado R, Masati L, Meehan S, Moledina S, Montani D, Othman S, Peacock AJ,
Pepke-Zaba J, Pollock V, Polwarth G, Ranganathan L, Rhodes CJ, Rue-Albrecht K,
Schotte G, Shipley D, Soubrier F, Southgate L, Scelsi L, Suntharalingam J, Tan
Y, Toshner M, Treacy CM, Trembath R, Vonk Noordegraaf A, Walker S, Wanjiku I,
Wharton J, Wilkins M, Wort SJ, Yates K, Alachkar H, Antrobus R, Arumugakani G,
Bacchelli C, Baxendale H, Bethune C, Bibi S, Booth C, Browning M, Burns S,
Chandra A, Cooper N, Davies S, Devlin L, Drewe E, Edgar D, Egner W, Ghurye R,
Gilmour K, Goddard S, Gordins P, Grigoriadou S, Hackett S, Hague R, Harper L,
Hayman G, Herwadkar A, Huissoon A, Jolles S, Kelleher P, Kumararatne D, Lear S,
Longhurst H, Lorenzo L, Maimaris J, Manson A, McDermott E, Murng S, Nejentsev S,
Noorani S, Oksenhendler E, Ponsford M, Qasim W, Quinti I, Richter A,
Samarghitean C, Sargur R, Savic S, Seneviratne S, Sewell C, Staples E, Stauss H,
Thaventhiran J, Thomas M, Welch S, Willcocks L, Yeatman N, Yong P, Ancliff P,
Babbs C, Layton M, Louka E, McGowan S, Mead A, Roy N, Chambers J, Dixon P, Estiu
C, Hague B, Marschall HU, Simpson M, Chong S, Emmerson I, Ginsberg L, Gosal D,
Hadden R, Horvath R, Mahdi-Rogers M, Manzur A, Marshall A, Matthews E, McCarthy
M, Reilly M, Renton T, Rice A, Themistocleous A, Vale T, Van Zuydam N, Walker S,
Ormondroyd L, Hudson G, Wei W, Yu Wai Man P, Whitworth J, Afzal M, Colby E,
Saleem M, Alavijeh OS, Cook HT, Johnson S, Levine AP, Wong EKS, Tan R, Boycott
KM, MacKenzie A, Majewski J, Brudno M, Bulman D, Dyment D. |
List the attenuated live viruses contained in the Fluzone intradermal quadrivalent vaccine. | The Fluzone Intradermal Quadrivalent vaccine contains 9 ug hemagglutinin per strain of the two A-strain viruses and both B-strain lineage viruses (Victoria and Yamagata). | INTRODUCTION: An intradermal version of Fluzone® split-virion inactivated
trivalent influenza vaccine, containing 9 µg hemagglutinin per strain of A/H1N1,
A/H3N2, and one B lineage virus (Fluzone Intradermal, Sanofi Pasteur), became
available in the US during the 2011-2012 influenza season for adults 18-64 years
of age. In advance of the 2015-2016 season, Fluzone Intradermal was replaced
with Fluzone Intradermal Quadrivalent vaccine, which contains 9 µg hemagglutinin
per strain of the two A-strain viruses and both B-strain lineage viruses
(Victoria and Yamagata).
AREAS COVERED: This literature review summarizes the history and mechanism of
intradermal vaccination, discusses the clinical trial results supporting the
immunogenicity and safety of Fluzone Intradermal Quadrivalent vaccine, and
describes the unique microinjection system used to deliver Fluzone Intradermal
Quadrivalent. Expert commentary: Fluzone Intradermal Quadrivalent may boost
confidence in influenza vaccination with the addition of a second B-lineage
strain. By using an innovative microinjection system, the vaccine is also
designed to address some of the logistic challenges faced by healthcare
providers administering immunizations. |
Which kinases are inhibited by Pyrotinib? | Pyrotinib is a novel irreversible EGFR/HER2 dual tyrosine kinase inhibitor that is used to treat HER2-positive breast cancer. | Pyrotinib is a novel irreversible tyrosine kinase inhibitor developed for the
treatment of human epidermal growth factor receptor 2 (HER2)-positive breast
cancer. The results of phase I clinical trial demonstrated that pyrotinib was
well tolerated and exhibited potent antitumor activity. As a promising
therapeutic agent for HER2-positive breast cancer, it is of great importance to
investigate the biotransformation of pyrotinib in humans and identify the major
enzymes involved in its metabolism during its early stage of development for
safety consideration. For this purpose, a robust analytical method based on
ultra-performance liquid chromatography/quadrupole time-of-flight mass
spectrometry (UPLC/Q-TOF MS) was established to characterize the metabolites of
pyrotinib in human plasma, feces, and urine, and identify the primary enzymes
responsible for its metabolism. As a result, a total of 24 metabolites were
identified, including 16 phase I metabolites resulting from dealkylation,
oxidation, dehydrogenation, and carbonylation, and 8 phase II metabolites
originating from cysteine and N-acetylcysteine conjugation. Pyrotinib was
absorbed into blood by 1h, reached its peak level at 4h, and afterwards
underwent slow elimination. The principal metabolites detected in humans (M1,
M2, and M5) were products resulting from O-depicoline and pyrrolidine lactam
formation, whose structures have been confirmed by the synthetic references. In
addition, fecal clearance was the major route of excretion for pyrotinib.
Further phenotyping experiment proved that CYP3A4 was the most active enzyme
responsible for the biotransformation of pyrotinib, implying the vital necessity
of the assessment of the potential CYP3A-mediated drug-drug interactions in
humans. Taken together, this study provided valuable metabolic data to explicate
the dynamic process of pyrotinib in humans, and important reference basis for
its safety evaluation and rational clinical application. The results will also
benefit the assessment of the contributions to the overall activity or toxicity
from the key metabolites. Author information:
(1)Shanghai Hengrui Pharmaceutical Co., Ltd., 279 Wenjing Road, Shanghai 200245,
China. Electronic address: [email protected].
(2)Jiangsu Hengrui Medicine Co., Ltd., Jiangsu, Lianyungang 222047, China.
Electronic address: [email protected].
(3)Shanghai Hengrui Pharmaceutical Co., Ltd., 279 Wenjing Road, Shanghai 200245,
China. Electronic address: [email protected].
(4)Jiangsu Hengrui Medicine Co., Ltd., Jiangsu, Lianyungang 222047, China.
Electronic address: [email protected].
(5)Shanghai Hengrui Pharmaceutical Co., Ltd., 279 Wenjing Road, Shanghai 200245,
China. Electronic address: [email protected].
(6)Shanghai Hengrui Pharmaceutical Co., Ltd., 279 Wenjing Road, Shanghai 200245,
China. Electronic address: [email protected].
(7)State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica,
Chinese Academy of Sciences, Shanghai 201203, China. Electronic address:
[email protected].
(8)State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica,
Chinese Academy of Sciences, Shanghai 201203, China. Electronic address:
[email protected].
(9)State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica,
Chinese Academy of Sciences, Shanghai 201203, China. Electronic address:
[email protected].
(10)Shanghai Hengrui Pharmaceutical Co., Ltd., 279 Wenjing Road, Shanghai
200245, China. Electronic address: [email protected].
(11)Jiangsu Hengrui Medicine Co., Ltd., Jiangsu, Lianyungang 222047, China;
China Pharmaceutical University, Jiangsu Key Laboratory of Drug Design and
Optimization, Nanjing 210009, China. Electronic address:
[email protected]. Purpose This phase I study assessed the safety, tolerability, pharmacokinetics,
antitumor activity, and predictive biomarkers of pyrotinib, an irreversible
pan-ErbB inhibitor, in patients with human epidermal growth factor receptor 2
(HER2)-positive metastatic breast cancer. Patients and Methods Pyrotinib was
administered continuously, orally, once per day to patients who did not have
prior exposure to tyrosine kinase inhibitors of HER2. Planned dose escalation
was 80, 160, 240, 320, 400, and 480 mg. For pharmacokinetic analysis, timed
blood samples were collected on day 1 and day 28. Next-generation sequencing was
performed on circulating tumor DNA and genomic DNA from tumor samples. Results
Thirty-eight patients were enrolled. The dose-limiting toxicity was grade 3
diarrhea, which occurred in two patients administered 480 mg of pyrotinib; thus,
the maximum tolerated dose was 400 mg. Common pyrotinib-related adverse events
included diarrhea (44.7% [17 of 38]), nausea (13.2% [five of 38]), oral
ulceration (13.2% [five of 38]), asthenia (10.5% [four of 38]), and leukopenia
(10.5% [four of 38]). The only grade 3 adverse event was diarrhea.
Pharmacokinetic analyses indicated that pyrotinib exposure was dose dependent.
The overall response rate was 50.0% (18 of 36), and the clinical benefit rate
(complete response + partial response + stable disease ≥ 24 weeks) was 61.1% (22
of 36). The median progression-free survival was 35.4 weeks (95% CI, 23.3 to
40.0 weeks). The overall response rate was 83.3% (10 of 12) in trastuzumab-naive
patients and 33.3% (eight of 24) in trastuzumab-pretreated patients. Preliminary
results suggest that PIK3CA and TP53 mutations in circulating tumor DNA ( P =
.013) rather than in archival tumor tissues ( P = .474) may predict the efficacy
of pyrotinib. Conclusion Continuous once-per-day pyrotinib was well tolerated
and demonstrated promising antitumor activity in HER2-positive patients with
metastatic breast cancer. The maximum tolerated dose was established as 400 mg.
Diarrhea was the dose-limiting toxicity. The promising antitumor activity and
acceptable tolerability of pyrotinib warrant its further evaluation in a phase
II study. Pyrotinib is an irreversible dual pan-ErbB receptor tyrosine kinase inhibitor
developed for the treatment of HER2-positive advanced solid tumours. Based on
positive results in a phase II trial, the drug recently received conditional
approval in China for use in combination with capecitabine for the treatment of
HER2-positive, advanced or metastatic breast cancer in patients previously
treated with anthracycline or taxane chemotherapy. This article summarizes the
milestones in the development of pyrotinib leading to this first global approval
for the treatment of HER2-positive advanced breast cancer. |
Which bacteria causes rat bite fever? | Rat bite fever is caused by Streptobacillus moniliformis. Infection induces typical but not pathognomonic clinical signs, such as local purulent wound infection followed by maculopapular exanthema, myalgia as well as purulent joint infections. | A 23-year-old black woman was admitted to the hospital in premature labor with
intact amniotic membranes. The patient was afebrile and did not have any obvious
signs of infection. Gram stain of the amniotic fluid, obtained via
transabdominal amniocentesis, revealed the presence of gram-negative rods. The
bacterium was identified as Streptobacillus moniliformis, the agent of rat-bite
fever. Rat-bite fever is an uncommon bacterial illness resulting from infection with
Streptobacillus moniliformis that is often transmitted by the bite of a rat. The
cutaneous findings in rat-bite fever are nonspecific but have been described as
maculopapular or petechial. We describe a 9-year-old girl with acrally
distributed hemorrhagic pustules, fever, and arthralgias. Diagnosis was delayed
because of difficulty in identifying the pathologic organism. She was
successfully treated with 10 days of ceftriaxone. Rat bite fever is a rare infection typically caused by Streptobacillus
moniliformis. The mode of transmission is most commonly through a bite or
scratch from an infected rat. This disease is characterized by polyarthritis,
fever, and a delayed onset erythematous maculopapular rash of the extremities.
The authors report a case of rat bite fever, which led to septic arthritis of
the hip. To the authors' knowledge, the complication of hip sepsis requiring an
arthrotomy has not been reported in the literature. The orthopaedist should be
aware of not only Streptobacillus moniliformis, but also of other zoonotic
organisms, which potentially can cause septic arthritis and warrant treatment
with specific antibiotics. Streptobacillus moniliformis is a Gram-negative bacterium found in various
laboratory animal species and is the cause of rat bite fever and Haverhill fever
in man. In order to evaluate a polymerase chain reaction (PCR) for the detection
of this zoonotic bacterium in animal tissues a set of primers was designed based
on the DNA base sequence of part of the 16S rRNA gene from 11 S. moniliformis
strains. The PCR detected as few as 2-6 copies of S. moniliformis DNA. A 296 bp
DNA fragment was amplified from S. moniliformis strains from rodents, humans and
turkeys. Amplicons of about the same size were obtained from Fusobacterium
necrogenes and Sebaldella (Bacteroides) termitidis but Bfa I treatment of these
amplicons did not result in the S. moniliformis specific 130 bp DNA fragment.
The in silico evaluation of 14 additional Fusobacterium spp. and 12 unculturable
phytoplasmas indicated that none is likely to give rise to confusing amplicons
or DNA fragments. The PCR detected S. moniliformis infection in all four orally-
and four intravenously-infected C57BL/6 mice and the bacterium was cultured from
all but one mouse. The PCR detected S. moniliformis infection in all 12
orally-infected WU rats, and in five of eight rats exposed to natural infection.
Enzyme linked immunosorbent assay (ELISA) and PCR were equally successful in
detecting infection in rats but S. moniliformis was not detected by using
culture. Rat bite fever, caused by Streptobacillus moniliformis, is a systemic illness
classically characterized by fever, rigors, and polyarthralgias. If left
untreated, it carries a mortality rate of 10%. Unfortunately, its nonspecific
initial presentation combined with difficulties in culturing its causative
organism produces a significant risk of delay or failure in diagnosis. The
increasing popularity of rats and other rodents as pets, together with the risk
of invasive or fatal disease, demands increased attention to rat bite fever as a
potential diagnosis. The clinical and biological features of rat bite fever and
Streptobacillus moniliformis are reviewed, providing some distinguishing
features to assist the clinician and microbiologist in diagnosis. A 24-year old man presented himself to the emergency ward with complaints of
fever, nausea, headache, muscle ache and chest pain. Two weeks before
presentation he had been bitten by a pet rat. We determined that he had
bacteraemia caused by a Streptobacillus moniliformis infection, which led to the
development of an illness called rat bite fever. S. moniliformis is a
pleomorphic gram-negative rod-shaped bacterium that is considered part of the
normal nasopharyngeal flora in rats. It is the cause of two similar illnesses:
rat bite fever and Haverhill fever. Clinicians should consider these infections
in the work-up of unexplained fever or sepsis, certainly in the presence of
known exposure to rats. Treatment consists of antibiotics. Streptobacillus moniliformis is a fastidious growing Gram-negative bacillus
responsible of rat-bite fever. We describe here the first report of this disease
in la Réunion and the first isolation using shell vial cell culture from a blood
culture bottle with a bacterium suspected to be dead. BACKGROUND: The Leptotrichiaceae are a family of fairly unnoticed bacteria
containing both microbiota on mucous membranes as well as significant pathogens
such as Streptobacillus moniliformis, the causative organism of streptobacillary
rat bite fever. Comprehensive genomic studies in members of this family have so
far not been carried out. We aimed to analyze 47 genomes from 20 different
member species to illuminate phylogenetic aspects, as well as genomic and
discriminatory properties.
RESULTS: Our data provide a novel and reliable basis of support for previously
established phylogeny from this group and give a deeper insight into
characteristics of genome structure and gene functions. Full genome analyses
revealed that most S. moniliformis strains under study form a heterogeneous
population without any significant clustering. Analysis of infra-species
variability for this highly pathogenic rat bite fever organism led to the
detection of three specific variable number tandem analysis loci with high
discriminatory power.
CONCLUSIONS: This highly useful and economical tool can be directly employed in
clinical samples without laborious prior cultivation. Our and prospective
case-specific data can now easily be compared by using a newly established MLVA
database in order to gain a better insight into the epidemiology of this
presumably under-reported zoonosis. We report acute tetraplegia caused by rat bite fever in a 59-year old man (snake
keeper) and transmission of Streptobacillus moniliformis. We found an identical
characteristic bacterial pattern in rat and human samples, which validated
genotyping-based evidence for infection with the same strain, and identified
diagnostic difficulties concerning infection with this microorganism. Rat bite fever due to Streptobacillus moniliformis induces typical but not
pathognomonic clinical signs, such as local purulent wound infection followed by
maculopapular exanthema, myalgia as well as purulent joint infections. Severe
complications, such as osteomyelitis and endocarditis are possible. it seems
that this infection is rarely diagnosed but this infection could be much more
common because the final diagnostic proof is difficult to achieve. Firstly, the
culture of these bacteria is critical because the bacteria are fastidious and
secondly the exact differentiation of the isolates is hardly possible by
standard laboratory methods. Modern techniques such as mass spectroscopy
(MALDI-TOF) and molecular biology allow a precise clarification. Surgical
cleansing of infection sites in combination with a rational antibiotic therapy,
for example with beta-lactam antibiotics, are generally able to cure the
infection if treatment is started early enough. In addition, vaccinations, for
example against tetanus and rabies have to be considered in this situation as
for all other bite wound infections. We report a case of rat-bite fever in a 94-year-old woman with Streptobacillus
notomytis infection. We established an epidemiologic link between exposure to
rats and human infection by performing nested PCRs that detected S. notomytis in
the intraoral swab specimens obtained from rats captured in the patient's house. |
What is the role of Gata3 in Th2 cells? | RHS6 coordinately regulates the Th2 cytokine genes by recruiting GATA3, SATB1, and IRF4. RHS6 recruited transcription factors GATA3, SATB1, and IRF4, which play important roles in expression of all three Th2 cytokine genes IL-4-mediated STAT6 activation induces high levels of transcription of GATA3, a master regulator of Th2 cell differentiation, and enforced expression of GATA3 induces Th2 cytokine expression. | Age-related changes in lymphocytes are most prominent in the T cell compartment.
There have been substantial numbers of reports on T cell function in aged mice
and humans, such as on the production of Th1 and Th2 cytokines, but the results
show considerable variation and contradictions. In the present study, we used 8-
to 12-mo-old aging mice and a well-established in vitro Th1/Th2 cell
differentiation culture system to identify molecular defects in Th1/Th2 cell
differentiation that can be detected in the relatively early stages of aging.
The capability to differentiate into Th2 cells is reduced in aging mouse CD4(+)
T cells. Decreased activation of the ERK MAPK cascade upon TCR stimulation, but
normal intracellular-free calcium ion concentration mobilization and normal
IL-4-induced STAT6 activation were observed in aging mouse CD4(+) T cells. In
addition, reduced expression of GATA3 was detected in developing Th2 cells.
Chromatin remodeling of the Th2 cytokine gene locus was found to be impaired.
Th2-dependent allergic airway inflammation was milder in aging mice compared
with in young adult mice. These results suggest that the levels of Th2 cell
differentiation and resulting Th2-dependent immune responses, including allergic
airway inflammation, decline during aging through defects in the activation of
the ERK MAPK cascade, expression of GATA3 protein and GATA3-dependent chromatin
remodeling of the Th2 cytokine gene locus. In the present study, we provide the
first evidence indicating that a chromatin-remodeling event in T cells is
impaired by aging. Protein kinase C theta (PKCtheta) is essential for T cell activation, as it is
required for the activation of NF-kappaB and expression of IL-2. PKCtheta has
also been shown to affect NFAT activation and Th2 differentiation. To better
understand the role of PKCtheta in the regulation of T helper cells, we used
PKCtheta-deficient DO11.10 transgenic T cells to study its role in vitro.
DO11.10 Th1 cells deficient in PKCtheta produced significantly less TNF-alpha
and IL-2. The expression of Th2 cytokines, including IL-4, IL-5, IL-10, IL-13
and IL-24 was significantly reduced in PKCtheta-deficient T cells. Moreover, the
expression of the Th2 transcription factor, GATA3, was significantly reduced in
PKCtheta-deficient T cells. Overexpression of GATA3 by retroviral infection in
PKCtheta-deficient T cells resulted in increased expansion of IL-4-producing T
cells and higher IL-4 production than that of wild type Th2 cells. IL-5, IL-10,
IL-13 and IL-24 expressions were also rescued by GATA3 overexpression. Our
observations suggest that PKCtheta regulates Th2 cytokine expression via GATA3. Recently, it was reported that the expression of Runt-related transcription
factor 3 (Runx3) is up-regulated in CD4(+) helper T cells during Th1 cell
differentiation, and that Runx3 functions in a positive feed-forward manner with
the T-box family transcription factor, T-bet, which is a master regulator of Th1
cell differentiation. The relative expression levels of IFN-gamma and IL-4 are
also regulated by the Th2-associated transcription factor, GATA3. Here, we
demonstrate that Runx3 was induced in Th2 as well as Th1 cells and that Runx3
interacted with GATA3 and attenuated GATA3 transcriptional activity. Ectopic
expression of Runx3 in vitro in cultured cells or transgenic expression of Runx3
in mice accelerated CD4(+) cells to a Th1-biased population or down-modulated
Th2 responses, in part by neutralizing GATA3. Our results suggest that the
balance of Runx3 and GATA3 is one factor that influences the manifestation of
CD4(+) cells as the Th1 or Th2 phenotypes. Differentiation of naive CD4 T cells into Th2 cells is accompanied by chromatin
remodeling and increased expression of a set of Th2-specific genes, including
those encoding Th2 cytokines. IL-4-mediated STAT6 activation induces high levels
of transcription of GATA3, a master regulator of Th2 cell differentiation, and
enforced expression of GATA3 induces Th2 cytokine expression. However, it
remains unclear whether the expression of other Th2-specific genes is induced
directly by GATA3. A genome-wide unbiased chromatin immunoprecipitation assay
coupled with massive parallel sequencing analysis revealed that GATA3 bound to
1279 genes selectively in Th2 cells, and 101 genes in both Th1 and Th2 cells.
Simultaneously, we identified 26 highly Th2-specific STAT6-dependent inducible
genes by DNA microarray analysis-based three-step selection processes, and among
them 17 genes showed GATA3 binding. We assessed dependency on GATA3 for the
transcription of these 26 Th2-specific genes, and 10 genes showed increased
transcription in a GATA3-dependent manner, whereas 16 genes showed no
significant responses. The transcription of the 16 GATA3-nonresponding genes was
clearly increased by the introduction of an active form of STAT6, STAT6VT.
Therefore, although GATA3 has been recognized as a master regulator of Th2 cell
differentiation, many Th2-specific genes are not regulated by GATA3 itself, but
in collaboration with STAT6. CD4 T(h) are critical for orchestrating adaptive immune responses. The
expression of the transcription factor GATA3 (GATA-binding protein 3) is
up-regulated or down-regulated during T(h)2 or T(h)1 cell differentiation,
respectively. Furthermore, GATA3 is responsible for induction of T(h)2
differentiation and represses T(h)1 differentiation. In this review, we present
an updated view on the molecular mechanisms through which GATA3 regulates
T(h)1/T(h)2 differentiation. During T(h)2 cell differentiation, GATA3 directly
binds to the T(h)2 cytokine gene locus at several regions and regulates
expression. On the other hand, GATA3 inhibits T(h)1 cell differentiation by
preventing up-regulation of IL-12 receptor β2 and STAT4 (signal transducer and
activator of transcription 4) and neutralization of Runx3 (runt-related
transcription factor 3) function through protein-protein interaction. GATA3 may
also directly act on the Ifng gene. In summary, GATA3 serves as a
transcriptional activator or repressor through direct action on transcriptional
machinery and/or affecting chromatin remodeling at many critical loci encoding
cytokines, cytokine receptors, signaling molecules as well as transcription
factors that are involved in the regulation of T(h)1 and T(h)2 differentiation. T-bet and GATA3 regulate the CD4+ T cell Th1/Th2 cell fate decision but little
is known about the interplay between these factors outside of the murine Ifng
and Il4/Il5/Il13 loci. Here we show that T-bet and GATA3 bind to multiple distal
sites at immune regulatory genes in human effector T cells. These sites display
markers of functional elements, act as enhancers in reporter assays and are
associated with a requirement for T-bet and GATA3. Furthermore, we demonstrate
that both factors bind distal sites at Tbx21 and that T-bet directly activates
its own expression. We also show that in Th1 cells, GATA3 is distributed away
from Th2 genes, instead occupying T-bet binding sites at Th1 genes, and that
T-bet is sufficient to induce GATA3 binding at these sites. We propose these
aspects of T-bet and GATA3 function are important for Th1/Th2 differentiation
and for understanding transcription factor interactions in other T cell lineage
decisions. Th2 cells produce Th2 cytokines such as IL-4, IL-5 and IL-13, but repress Th1
cytokine IFNγ. Recent studies have revealed various distinct memory-type Th2
cell subsets, one of which produces a substantial amount of IFNγ in addition to
Th2 cytokines, however it remains unclear precisely how these Th2 cells produce
IFNγ. We herein show that phosphorylation of Gata3 at Ser308, Thr315 and Ser316
induces dissociation of a histone deacetylase Hdac2 from the Gata3/Chd4
repressive complex in Th2 cells. We also identify Akt1 as a
Gata3-phosphorylating kinase, and the activation of Akt1 induces derepression of
Tbx21 and Ifng expression in Th2 cells. Moreover, T-bet-dependent IFNγ
expression in IFNγ-producing memory Th2 cells appears to be controlled by the
phosphorylation status of Gata3 in human and murine systems. Thus, this study
highlights the molecular basis for posttranslational modifications of Gata3 that
control the regulation of IFNγ expression in memory Th2 cells. BACKGROUND: Asthma is a Th2 cell-driven inflammatory disease and a major public
health concern. The cis-acting element Rad50 hypersensitive site 6 (RHS6) in the
Th2 locus control region is essential for regulation of the Th2 cytokine genes;
however, its role in allergic airway inflammation and underlying molecular
mechanisms of the regulation by RHS6 are poorly understood.
OBJECTIVE: We sought to understand the role of RHS6 in the development of
allergic airway inflammation and its molecular mechanism for Th2 cytokine
expression.
METHODS: We used an ovalbumin-induced allergic inflammation model with
RHS6-deficient mice to examine the role of RHS6 in this process. To examine
molecular mechanism of RHS6 for Th2 cytokine expression, we used DNA affinity
chromatography and mass spectrometry, quantitative RT-PCR, ELISA, intracellular
cytokine staining, chromatin immunoprecipitation, and co-immunoprecipitation.
RESULTS: Deletion of RHS6 caused a dramatic resistance to allergic airway
inflammation. RHS6 recruited transcription factors GATA3, SATB1, and IRF4, which
play important roles in expression of all three Th2 cytokine genes. RHS6
deficiency caused inhibition of transcription factor-induced Th2 cytokine gene
expression.
CONCLUSION: RHS6 is a critical regulatory element for allergic airway
inflammation and for coordinate regulation of Th2 cytokine genes by recruiting
GATA3, SATB1, and IRF4. |
Describe the Disambiguate algorithm and its application in next generation sequencing data | Grafting of cell lines and primary tumours is a crucial step in the drug development process between cell line studies and clinical trials. Disambiguate is a program for computationally separating the sequencing reads of two species derived from grafted samples. Disambiguate operates on DNA or RNA-seq alignments to the two species and separates the components at very high sensitivity and specificity as illustrated in artificially mixed human-mouse samples. This allows for maximum recovery of data from target tumours for more accurate variant calling and gene expression quantification. Given that no general use open source algorithm accessible to the bioinformatics community exists for the purposes of separating the two species data, the Disambiguate tool presents a novel approach and improvement to performing sequence analysis of grafted samples. Both Python and C++ implementations are available and they are integrated into several open and closed source pipelines. Disambiguate is open source and is freely available at https://github.com/AstraZeneca-NGS/disambiguate. | Grafting of cell lines and primary tumours is a crucial step in the drug
development process between cell line studies and clinical trials. Disambiguate
is a program for computationally separating the sequencing reads of two species
derived from grafted samples. Disambiguate operates on DNA or RNA-seq alignments
to the two species and separates the components at very high sensitivity and
specificity as illustrated in artificially mixed human-mouse samples. This
allows for maximum recovery of data from target tumours for more accurate
variant calling and gene expression quantification. Given that no general use
open source algorithm accessible to the bioinformatics community exists for the
purposes of separating the two species data, the proposed Disambiguate tool
presents a novel approach and improvement to performing sequence analysis of
grafted samples. Both Python and C++ implementations are available and they are
integrated into several open and closed source pipelines. Disambiguate is open
source and is freely available at
https://github.com/AstraZeneca-NGS/disambiguate. |
Are ICAMS, Intracellular Adhesion Molecules, part of the immunoglobulin superfamily? | Intercellular adhesion molecule 3 (ICAM-3, also known as CD50), a human leukocyte-restricted immunoglobulin super-family (IgSF) member, has previously been implicated in apoptotic cell clearance, | Intercellular adhesion molecule-3 (ICAM-3, CD50), a member of the immunoglobulin
gene superfamily, is a major ligand for the lymphocyte function-associated
antigen 1 (LFA-1, CD18/CD11a) in the resting immune system and plays a role as a
signaling and costimulatory molecule on T lymphocytes. In this study we have
generated a large panel of anti-ICAM-3 monoclonal antibodies (mAb) and show that
the biological effects of these antibodies are critically dependent on the
epitope recognized. By using an adhesion assay employing COS cells expressing
LFA-1 binding to recombit chimeric ICAM-3-Fc proteins (which overcomes the
confounding effects of interleukocyte LFA-1/ICAM binding events), we have been
able to examine the effects of these antibodies in blocking LFA-1/ICAM-3
adhesion. Our data suggests that only a small minority of ICAM-3 mAb,
recognizing a distinct epitope, are able to mimic the effects of LFA-1 binding
to ICAM-3. Moreover these antibodies are functionally distinct as defined by
their costimulatory activity and ability to elicit interleukin-2 production and
cell proliferation in T lymphocytes. The collective interaction between cells is, in part, mediated by different
families of adhesion molecules. Intercellular adhesion molecules (ICAMs) are
structurally related members of the immunoglobulin supergene family and are
ligands for the beta2 integrin molecules present on leukocytes. Of the five
ICAMs identified, ICAM-1 is the most extensively studied. Although ICAM-1 is
expressed constitutively at low levels on endothelial cells and on some
lymphocytes and monocytes, its expression can be significantly increased in the
presence of cytokines (TNFalpha, IL-1, IFNgamma) and reactive oxygen species.
Depending upon cell type, ICAM-1 participates in trafficking of inflammatory
cells, in cell:cell interactions during antigen presentation, in microbial
pathogenesis, and in signal transduction through outside-in signaling events.
Again, depending upon cell type examined, ICAM-1 engagement has been documented
to activate specific kinases through phosphorylation, resulting in transcription
factor activation and increased cytokine production, increased cell membrane
protein expression, reactive oxygen species production, and cell proliferation. Lymphocyte recruitment to the central nervous system (CNS) is a critical step in
the pathogenesis of diseases such as multiple sclerosis (MS), meningitis and
posterior uveitis. The principle sequential stages that control lymphocyte
emigration from the blood have been widely reported, but only recently has
attention been directed towards the role of the vascular endothelium in actively
supporting transvascular migration. It has now been shown that adhesion
molecules, particularly those of the immunoglobulin super family (e.g. ICAM-1,
VCAM-1 and PECAM-1), not only act as ligands for leucocyte receptors but can
also serve as signal transducers. Engagement of these receptors initiates
endothelial signalling cascades that result in downstream effector mechanisms
which in turn influence the progression of neuroinflammation. In particular, it
has been shown that ICAM-1-mediated signalling in brain endothelial cells is a
crucial regulatory step in the process of lymphocyte migration through the
blood-brain barrier and as such represents an additional phase in the multistep
paradigm of leucocyte recruitment. In this article we review current
understanding of endothelial cell ICAM-1 signalling and discuss the importance
of these findings in relation to leucocyte trafficking to the CNS. Members of the immunoglobulin superfamily of endothelial adhesion molecules,
vascular cell adhesion molecule (VCAM-1) and intercellular cell adhesion
molecule (ICAM- 1), strongly participate in leukocyte adhesion to the
endothelium and play an important role in all stages of atherogenesis. The aim
of this study was to detect and quantify the changes of endothelial expression
of VCAM-1, and ICAM-1 in the vessel wall after the short-term administration of
simvastatin, atorvastatin, and micro dispersed derivatives of oxidised cellulose
(MDOC) in apolipoprotein-E-deficient (apoE(-/-)) mice atherosclerotic model.
Hyperlipidemic apoE(-/-) mice (n = 32) received normal chow diet or diet
containing simvastatin or atorvastatin 10 mg/kg/day or MDOC 50 mg/kg/day. Total
cholesterol, VLDL, LDL, HDL and TAG were measured and the endothelial expression
of VCAM-1 and ICAM-1 was visualized and quantified by means of
immunohistochemistry and stereology, respectively. Total cholesterol levels was
insignificantly lowered only in MDOC treated mice but not in mice treated with
statins. ICAM-1 endothelial expression was not affected by neither simvastatin
nor MDOC treatment. However, significant diminution of VCAM-1 endothelial
expression was observed in both atorvastatin and MDOC treated mice. These
results provide new information of potential hypolipidemic substance MDOC and
its potential anti-inflammatory effects. Furthermore, we have confirmed
anti-inflammatory effects of atorvastatin independent of plasma cholesterol
lowering. Thus, the results of this study show potential benefit of both MDOC
and atorvastatin treatment in apoE(-/-) mouse model of atherosclerosis
suggesting their possible combination might be of interest. BACKGROUND: Members of the immunoglobulin superfamily of endothelial adhesion
molecules, vascular cell adhesion molecule (VCAM-1) and intercellular cell
adhesion molecule (ICAM-1), participate in leukocyte adhesion to the endothelium
and play an important role in all stages of atherosclerosis. The aim of the
study was to examine the expression of VCAM-1 and ICAM-1 in the aorta of rats at
the early stages of atherosclerosis and the correlation with their plasma
concentrations.
MATERIALS AND METHODS: Male rats (n=44), 10 weeks of age, were divided in 4
groups. Groups A and C (n=12) were fed with rich cholesterol diet for 12 and 16
weeks, respectively. Group B (regression group, n=12) was fed for the first 12
weeks with rich cholesterol diet and for another 4 weeks with normal diet. Group
D (control group, n=8) was fed with normal diet for 12 weeks. We measured the
serum lipid profile, the concentration of soluble ICAM-1 and the
immunohistochemical expression of ICAM-1 and VCAM-1 in the endothelium, media
and vasa vasorum of the aorta.
RESULTS: There were significant differences (p<0.05) in the expression of ICAM-1
between group C (maximum time of rich cholesterol diet) and all other groups in
the 3 groups of the aorta studied. There was regression of the expression of
ICAM-1 in group B and significant differences (p<0.05) between group B and all
the other groups, except group D in the expression of ICAM-1. There were no
significant differences in the expression of VCAM-1 between any groups. The
serum concentration of soluble ICAM-1 positively correlated with the expression
of the molecule in the vasa vasorum (r=0.35, p<0.05) and fibroblasts/smooth
muscular cells (r=0.34, p<0.05) of the aorta.
CONCLUSION: A cholesterol diet plays a role in the expression of ICAM-1 but not
in that of VCAM-1 in the rat aorta. The expression of ICAM-1 in the aorta
regresses after the withdrawal of a cholesterol-rich diet. Soluble ICAM-1 is a
reliable measure of ICAM-1 expression in the aorta, vasa vasorum and
fibroblasts/smooth muscle cells. Intercellular adhesion molecules (ICAMs) belong to the immunoglobulin
superfamily and participate in diverse cellular processes including
host-pathogen interactions. ICAM-1 is expressed on various cell types including
macrophages, whereas ICAM-4 is restricted to red blood cells. Here we report the
identification of an 11-kDa synthetic protein, M5, that binds to human ICAM-1
and ICAM-4, as shown by in vitro interaction studies, surface plasmon resoce
and immunolocalization. M5 greatly inhibits the invasion of macrophages and
erythrocytes by Mycobacterium tuberculosis and Plasmodium falciparum,
respectively. Pharmacological and siRNA-mediated inhibition of ICAM-1 expression
also results in reduced M. tuberculosis invasion of macrophages. ICAM-4 binds to
P. falciparum merozoites, and the addition of recombit ICAM-4 to parasite
cultures blocks invasion of erythrocytes by newly released merozoites. Our
results indicate that ICAM-1 and ICAM-4 play roles in host cell invasion by M.
tuberculosis and P. falciparum, respectively, either as receptors or as crucial
accessory molecules. STUDY DESIGN: We investigated the association between ICAM-1, -2, -3 plasma
levels and ankylosing spondylitis (AS) disease activity.
OBJECTIVE: In the present study, we aimed to investigate the association between
ICAM-1, -2, -3 plasma levels and AS disease activity in the Chinese Han
population.
SUMMARY OF BACKGROUND DATA: AS is a chronic inflammatory rheumatic disease that
effects the sacroiliac joints and axial skeleton. The intercellular adhesion
molecules (ICAMs) are members of the immunoglobulin superfamily and have been
identified to play major roles in inflammation and immune responses.
METHODS: A total of 60 patients with AS and 60 healthy individuals were
selected. The plasma levels of proinflammatory cytokines, including tumor
necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and ICAM-1, -2, -3, were
analyzed by ELISA. Disease severity-related indexes, including the Bath
ankylosing spondylitis disease activity index (BASDAI), Bath ankylosing
spondylitis functional index (BASFI), and ankylosing spondylitis disease
activity score (ASDAS), were assessed, along with the erythrocyte sedimentation
rate (ESR) and C-reactive protein (CRP) level.
RESULTS: Both ICAM-1 and ICAM-2 levels in plasma were markedly increased in AS
patients compared with levels in the plasma of controls. There was no difference
between controls and patients in term of ICAM-3 levels. Furthermore, in
patients, correlation analysis showed that TNF-α and IL-6 production, as well as
the ESR and CRP levels, have positive relationships with ICAM-1 and ICAM-2
plasma levels; the BASDAI, BASFI, and ASDAS scores were also found to be
positively correlated with ICAM-2. However, no significant correlations between
ICAM-1 levels and BASDAI, BASFI, or ASDAS were detected in our study.
CONCLUSION: The current findings suggest that ICAM-2 may be a potential
biomarker reflecting disease activity and functional ability in AS patients.
LEVEL OF EVIDENCE: 5. Intercellular adhesion molecule-1 (ICAM-1) is a member of an immunoglobulin-like
superfamily of adhesion molecules that mediate leukocyte adhesion to vascular
endothelium and are involved in several cardiovascular diseases, including
ischemia-reperfusion injury, myocardial infarction, and atherosclerosis.
However, the role of ICAM-1 in angiotensin II (ANG II)-induced cardiac
remodeling in mice remains unclear. Wild-type mice were administered an IgG
control or ICAM-1 neutralizing antibody (1 and 2 mg/mouse, respectively) and ANG
II (1,000 ng·kg-1·min-1) for up to 14 days. Cardiac contractile function and
structure were detected by echocardiography. Hypertrophy, fibrosis, and
inflammation were assessed by histological examination. The infiltration of
lymphocyte function-associated antigen-1 (LFA-1+) monocytes/macrophages was
assessed by immunostaining. The mRNA expression of genes was evaluated by
quantitative RT-PCR analysis. Protein levels were tested by immunoblotting. We
found that ICAM-1 expression in ANG II-infused hearts and ICAM-1 levels in serum
from human patients with heart failure were significantly increased. Moreover,
ANG II infusion markedly enhanced ANG II-induced hypertension, caused cardiac
contractile dysfunction, and promoted cardiac hypertrophy, fibrosis, and LFA-1+
macrophage infiltration. Conversely, blockage of ICAM-1 with a neutralizing
antibody dose-dependently attenuated these effects. Moreover, our in vitro data
further demonstrated that blocking ICAM-1 inhibited ANG II-induced LFA-1+
macrophage adhesion to endothelial cells and migration. In conclusion, these
results provide novel evidence that blocking ICAM-1 exerts a protective effect
in ANG II-induced cardiac remodeling at least in part through the modulation of
adhesion and infiltration of LFA-1+ macrophages in the heart. Inhibition of
ICAM-1 may represent a new therapeutic approach for hypertrophic heart
diseases.NEW & NOTEWORTHY Leukocyte adhesion to vascular endothelium is a
critical step in cardiovascular diseases. ICAM-1 is a member of
immunoglobulin-like superfamily of adhesion molecules that binds LFA-1 to
mediate leukocytes adhesion and migration. However, the significance of ICAM-1
in ANG II-induced cardiac remodeling remains unclear. This study reveals that
blocking of ICAM-1 prevents ANG II-induced cardiac remodeling via modulating
adhesion and migration of LFA-1+ monocytes, may serve as a novel therapeutic
target for hypertensive cardiac diseases. |
Is traditional Chinese medicine associated with a decreased risk of heart failure in breast cancer patients receiving doxorubicin treatment? | Traditional Chinese medicine is associated with a decreased risk of heart failure in breast cancer patients receiving doxorubicin treatmen | |
What receptor is associated with the protein encoded by the Spätzle gene? | Currently, as a ligand for the Toll-1 receptor, only Spatzle (Spz) has been identified and characterized. | The Drosophila gene Spätzle encodes the activating ligand for the Toll receptor.
This signaling pathway is required for dorso-ventral patterning in the early
embryo and an antifungal immune response in larvae and adults. The genome
sequence of Drosophila shows that there are a total of eight Toll-like receptors
and these may function in other aspects of embryonic development and innate
immunity. Here we describe five Drosophila homologues of Spätzle (Spz2-6) found
using an iterative searching method. All five appear to encode proteins
containing neurotrophin-like cystine-knot domains. In addition, most retain a
characteristic intron-exon structure shared with the prototype Spätzle gene.
This provides evidence that the family arose by ancient gene duplication events
and indicates that the gene products may represent activating ligands for
corresponding Toll receptors. Expression studies show that only Spz4 is
expressed strongly in larvae and adults and thus may be involved in an ancillary
antifungal response mediated by Toll-5. By contrast, Spz6 shows a complex
spatial and temporally regulated expression pattern in the late embryo. Thus the
new Toll/Spätzle families of signaling molecules may have important roles in
other aspects of development and immunity. Spätzle protein is an extracellular ligand of Toll receptor in Toll signaling
pathway involved in the embryonic dorsoventral patterning and in the innate
immunity. In this study, a spätzle gene of freshwater prawn, Macrobrachium
rosenbergii (MrSpz) was isolated and characterized. The open reading frame of
MrSpz consisted of 747 nucleotides encoding 248 amino acid residues containing a
signal peptide and C-terminal spätzle activated domain. MrSpz shared high
similarity to spätzle of Fenneropenaeus chinensis (FcSpz) at 92% identity and
Marsupenaeus japonicus (MjSpz) at 83% identity. Phylogenetic analysis was
performed and the results revealed that MrSpz was a member of the clade
containing LvSpz3 of Litopenaeus vannamei, FcSpz and Penaeus monodon spätzle
protein. The expression distribution at transcriptional level in various tissues
of normal prawn revealed that the MrSpz was detected in gills, heart and
hepatopancreas while no expression was observed in hemocyte, muscle and stomach.
In the Aeromonas caviae challenged prawn, the expression level of MrSpz in
hemocyte was increased gradually at 6, 12 and 24 h post-injection. Furthermore,
in MrSpz knocked down prawn injected with Aeromonas caviae, the mortality rate
were higher than that of non-related dsRNA group and control group. These
results suggest that MrSpz protein may play a key role in the innate immunity of
M. rosenbergii, especially in response to Gram-negative bacteria A. caviae
invasion. The Drosophila Toll-1 receptor is involved in embryonic development, innate
immunity, and tissue homeostasis. Currently, as a ligand for the Toll-1
receptor, only Spätzle (Spz) has been identified and characterized. We
previously reported that Drosophila larva-derived tissue extract contains ligand
activity for the Toll-1 receptor, which differs from Spz based on the
observation that larval extract prepared from spz mutants possessed full ligand
activity. Here, we demonstrate that Spz5, a member of the Spz family of
proteins, functions as a ligand for the Toll-1 receptor. Processing of Spz5 by
Furin protease, which is known to be important for ligand activity of Spz5 to
Toll-6, is not required for its function to the Toll-1 receptor. By generating a
spz5 null mutant, we further showed that the Toll-1 ligand activity of
larva-derived extract is mainly derived from Spz5. Finally, we found a genetic
interaction between spz and spz5 in terms of developmental processes. This study
identified a novel ligand for the Drosophila Toll-1 receptor, providing evidence
that Toll-1 is a multi-ligand receptor, similar to the mammalian Toll-like
receptor. The Toll signaling pathway in Drosophila melanogaster regulates several
immune-related functions, including the expression of antimicrobial peptide
(AMP) genes. The canonical Toll receptor (Toll-1) is activated by the cytokine
Spätzle (Spz-1), but Drosophila encodes eight other Toll genes and five other
Spz genes whose interactions with one another and associated functions are less
well-understood. Here, we conducted in vitro assays in the Drosophila S2 cell
line with the Toll/interleukin-1 receptor (TIR) homology domains of each Toll
family member to determine whether they can activate a known target of Toll-1,
the promoter of the antifungal peptide gene drosomycin. All TIR family members
activated the drosomycin promoter, with Toll-1 and Toll-7 TIRs producing the
highest activation. We found that the Toll-1 and Toll-7 ectodomains bind Spz-1,
-2, and -5, and also vesicular stomatitis virus (VSV) virions, and that Spz-1,
-2, -5, and VSV all activated the promoters of drosomycin and several other AMP
genes in S2 cells expressing full-length Toll-1 or Toll-7. In vivo experiments
indicated that Toll-1 and Toll-7 mutants could be systemically infected with two
bacterial species (Enterococcus faecalis and Pseudomonas aeruginosa), the
opportunistic fungal pathogen Candida albicans, and VSV with different survival
times in adult females and males compared with WT fly survival. Our results
suggest that all Toll family members can activate several AMP genes. Our results
further indicate that Toll-1 and Toll-7 bind multiple Spz proteins and also VSV,
but they differentially affect adult survival after systemic infection,
potentially because of sex-specific differences in Toll-1 and Toll-7 expression. |
List targeted genome editing methodologies | Genome editors such as CRISPR/Cas9 and TALENs are at the forefront of research into methodologies for targeted modification of the mammalian genome. | |
Is PTEN a tumour suppressor? | Yes | |
Which is the function of the PRDM9 protein in mammals? | PRDM9 is a major determinant of meiotic recombination hotspots in humans and mice. | During mammalian meiosis, double-strand breaks are deliberately made throughout
the genome and then repaired, leading to the exchange of genetic material
between copies of chromosomes. How the locations of breaks are specified was
largely unknown until a fortuitous confluence of statistical genetics and
molecular biology uncovered the role of PRDM9, a DNA binding protein. Many
properties of this protein remain mysterious, however, including how it binds to
DNA, how it contributes to male infertility-both in humans, and in hybrid
mice-and why, in spite of its fundamental function in meiosis, its binding
domain varies extensively among humans and across mammals. We present a brief
summary of what has recently been learned about PRDM9 in different fields,
focusing on the puzzles yet to be resolved. BACKGROUND: Meiotic recombination ensures proper segregation of homologous
chromosomes and creates genetic variation. In many organisms, recombination
occurs at limited sites, termed 'hotspots', whose positions in mammals are
determined by PR domain member 9 (PRDM9), a long-array zinc-finger and
chromatin-modifier protein. Determining the rules governing the DNA binding of
PRDM9 is a major issue in understanding how it functions.
RESULTS: Mouse PRDM9 protein variants bind to hotspot DNA sequences in a manner
that is specific for both PRDM9 and DNA haplotypes, and that in vitro binding
parallels its in vivo biological activity. Examining four hotspots, three
activated by Prdm9Cst and one activated by Prdm9Dom2, we found that all binding
sites required the full array of 11 or 12 contiguous fingers, depending on the
allele, and that there was little sequence similarity between the binding sites
of the three Prdm9Cst activated hotspots. The binding specificity of each
position in the Hlx1 binding site, activated by Prdm9Cst, was tested by mutating
each nucleotide to its three alternatives. The 31 positions along the binding
site varied considerably in the ability of alternative bases to support binding,
which also implicates a role for additional binding to the DNA phosphate
backbone.
CONCLUSIONS: These results, which provide the first detailed mapping of PRDM9
binding to DNA and, to our knowledge, the most detailed analysis yet of DNA
binding by a long zinc-finger array, make clear that the binding specificities
of PRDM9, and possibly other long-array zinc-finger proteins, are unusually
complex. Developmental progress of germ cells through meiotic phases is closely tied to
ongoing meiotic recombination. In mammals, recombination preferentially occurs
in genomic regions known as hotspots; the protein that activates these hotspots
is PRDM9, containing a genetically variable zinc finger (ZNF) domain and a
PR-SET domain with histone H3K4 trimethyltransferase activity. PRDM9 is required
for fertility in mice, but little is known about its localization and
developmental dynamics. Application of spermatogenic stage-specific markers
demonstrates that PRDM9 accumulates in male germ cell nuclei at pre-leptonema to
early leptonema but is no longer detectable in nuclei by late zygonema. By the
pachytene stage, PRDM9-dependent histone H3K4 trimethyl marks on hotspots also
disappear. PRDM9 localizes to nuclei concurrently with the deposition of meiotic
cohesin complexes, but is not required for incorporation of cohesin complex
proteins into chromosomal axial elements, or accumulation of normal numbers of
RAD51 foci on meiotic chromatin by late zygonema. Germ cells lacking PRDM9
exhibit inefficient homology recognition and synapsis, with aberrant repair of
meiotic DNA double-strand breaks and transcriptional abnormalities
characteristic of meiotic silencing of unsynapsed chromatin. Together, these
results on the developmental time course for nuclear localization of PRDM9
establish its direct window of function and demonstrate the independence of
chromosome axial element formation from the concurrent PRDM9-mediated activation
of recombination hotspots. |
Which graph database is used by the Reactome graph database? | Reactome is a free, open-source, open-data, curated and peer-reviewed knowledgebase of biomolecular pathways. The Neo4j graph database and its query language, Cypher, provide efficient access to the complex Reactome data model, facilitating easy traversal and knowledge discovery. | Reactome is a free, open-source, open-data, curated and peer-reviewed
knowledgebase of biomolecular pathways. One of its main priorities is to provide
easy and efficient access to its high quality curated data. At present,
biological pathway databases typically store their contents in relational
databases. This limits access efficiency because there are performance issues
associated with queries traversing highly interconnected data. The same data in
a graph database can be queried more efficiently. Here we present the rationale
behind the adoption of a graph database (Neo4j) as well as the new
ContentService (REST API) that provides access to these data. The Neo4j graph
database and its query language, Cypher, provide efficient access to the complex
Reactome data model, facilitating easy traversal and knowledge discovery. The
adoption of this technology greatly improved query efficiency, reducing the
average query time by 93%. The web service built on top of the graph database
provides programmatic access to Reactome data by object oriented queries, but
also supports more complex queries that take advantage of the new underlying
graph-based data storage. By adopting graph database technology we are providing
a high performance pathway data resource to the community. The Reactome graph
database use case shows the power of NoSQL database engines for complex
biological data types. |
What is the route of administration of vaxchora? | Vaxchora is an oral vaccine. | OBJECTIVE: To review trials evaluating the efficacy and safety of Vaxchora, a
reformulated, single-dose, oral, lyophilized Vibrio cholerae CVD 103-HgR vaccine
for the prevention of travel-related cholera caused by V cholerae serogroup O1.
DATA SOURCES: A literature search was conducted using MEDLINE (1946 to January
week 3, 2017) and EMBASE (1996 to 2017 week 3). Keywords included oral cholera
vaccine, single-dose, Vaxchora, and CVD 103-HgR. Limits included human, clinical
trials published in English since 2010. ClinicalTrials.gov was used as a source
for unpublished data. Additional data sources were obtained through
bibliographic review of selected articles.
STUDY SELECTION AND DATA EXTRACTION: Studies that addressed the safety and
efficacy of Vaxchora, the reformulated, single-dose oral CVD 103-HgR cholera
vaccine, were selected for analysis.
DATA SYNTHESIS: Approval of Vaxchora, was based on efficacy of the vaccine in
human trials demonstrating 90.3% protection among those challenged with V
cholerae 10 days after vaccination and in immunogenicity studies with 90%
systemic vibriocidal antibody conversion at 6 months after a single-dose of
vaccine. Tolerability was acceptable, with the most common adverse effects
reported to be fatigue, headache, and abdominal pain.
CONCLUSION: Vaxchora is the only FDA-approved, single-dose oral vaccine for the
prevention of cholera caused by V cholerae serogroup O1 in adult travelers from
the United States going to cholera-affected areas. Safety and efficacy has not
been established in children, immunocompromised persons, and pregt or
breastfeeding women or those living in cholera-endemic areas. |
What is the target of the drug remdesivir? | remdesivir is a polymerase inhibitor | Emerging coronaviruses (CoVs) cause severe disease in humans, but no approved
therapeutics are available. The CoV nsp14 exoribonuclease (ExoN) has complicated
development of antiviral nucleosides due to its proofreading activity. We
recently reported that the nucleoside analogue GS-5734 (remdesivir) potently
inhibits human and zoonotic CoVs in vitro and in a severe acute respiratory
syndrome coronavirus (SARS-CoV) mouse model. However, studies with GS-5734 have
not reported resistance associated with GS-5734, nor do we understand the action
of GS-5734 in wild-type (WT) proofreading CoVs. Here, we show that GS-5734
inhibits murine hepatitis virus (MHV) with similar 50% effective concentration
values (EC50) as SARS-CoV and Middle East respiratory syndrome coronavirus
(MERS-CoV). Passage of WT MHV in the presence of the GS-5734 parent nucleoside
selected two mutations in the nsp12 polymerase at residues conserved across all
CoVs that conferred up to 5.6-fold resistance to GS-5734, as determined by EC50
The resistant viruses were unable to compete with WT in direct coinfection
passage in the absence of GS-5734. Introduction of the MHV resistance mutations
into SARS-CoV resulted in the same in vitro resistance phenotype and attenuated
SARS-CoV pathogenesis in a mouse model. Finally, we demonstrate that an MHV
mutant lacking ExoN proofreading was significantly more sensitive to GS-5734.
Combined, the results indicate that GS-5734 interferes with the nsp12 polymerase
even in the setting of intact ExoN proofreading activity and that resistance can
be overcome with increased, nontoxic concentrations of GS-5734, further
supporting the development of GS-5734 as a broad-spectrum therapeutic to protect
against contemporary and emerging CoVs.IMPORTANCE Coronaviruses (CoVs) cause
severe human infections, but there are no approved antivirals to treat these
infections. Development of nucleoside-based therapeutics for CoV infections has
been hampered by the presence of a proofreading exoribonuclease. Here, we expand
the known efficacy of the nucleotide prodrug remdesivir (GS-5734) to include a
group β-2a CoV. Further, GS-5734 potently inhibits CoVs with intact
proofreading. Following selection with the GS-5734 parent nucleoside, 2 amino
acid substitutions in the nsp12 polymerase at residues that are identical across
CoVs provide low-level resistance to GS-5734. The resistance mutations decrease
viral fitness of MHV in vitro and attenuate pathogenesis in a SARS-CoV animal
model of infection. Together, these studies define the target of GS-5734
activity and demonstrate that resistance is difficult to select, only partial,
and impairs fitness and virulence of MHV and SARS-CoV, supporting further
development of GS-5734 as a potential effective pan-CoV antiviral. |
What is known about EphA2 in drug resistance? | ligand- and tyrosine kinase-independent EphA2 signaling (the noncanonical pathway) promotes tumor survival and metastasis and controls acquired drug resistance and maintenance of cancer stem cell-like properties.
Findings confirm EPHA2 as an actionable drug target, provide a rational basis for drug combination approaches, and indicate that chemical proteomics is broadly applicable for the discovery of kinase inhibitor resistance. | Tyrosine kinase inhibitors (TKIs) have become an important therapeutic option
for treating several forms of cancer. Gefitinib, an inhibitor of the epidermal
growth factor receptor (EGFR), is in clinical use for treating non-small cell
lung cancer (NSCLC) harboring activating EGFR mutations. However, despite high
initial response rates, many patients develop resistance to gefitinib. The
molecular mechanisms of TKI resistance often remain unclear. Here, we describe a
chemical proteomic approach comprising kinase affinity purification (kinobeads)
and quantitative mass spectrometry for the identification of kinase inhibitor
resistance mechanisms in cancer cells. We identified the previously described
amplification of MET and found EPHA2 to be more than 10-fold overexpressed (p <
0.001) in gefitinib-resistant HCC827 cells suggesting a potential role in
developing resistance. siRNA-mediated EPHA2 knock-down or treating cells with
the multikinase inhibitor dasatinib restored sensitivity to gefitinib. Of all
dasatinib targets, EPHA2 exhibited the most drastic effect (p < 0.001). In
addition, EPHA2 knockdown or ephrin-A1 treatment of resistant cells decreased
FAK phosphorylation and cell migration. These findings confirm EPHA2 as an
actionable drug target, provide a rational basis for drug combination
approaches, and indicate that chemical proteomics is broadly applicable for the
discovery of kinase inhibitor resistance. Author information:
(1)Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee.
(2)Division of Rheumatology and Immunology, Vanderbilt University, Nashville,
Tennessee.
(3)Department of Biological Chemistry and Molecular Pharmacology, Harvard
Medical School, Boston, Massachusetts. Dana Farber Cancer Institute, Harvard
Medical School, Boston, Massachusetts.
(4)Department of Pathology, Microbiology, and Immunology, Vanderbilt University,
Nashville, Tennessee.
(5)Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee.
Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee.
(6)Department of Biostatistics, Vanderbilt University, Nashville, Tennessee.
(7)Vanderbilt University Institute of Imaging Science, Vanderbilt University,
Nashville, Tennessee.
(8)Department of Pathology, Microbiology, and Immunology, Vanderbilt University,
Nashville, Tennessee. Vanderbilt-Ingram Cancer Center, Vanderbilt University,
Nashville, Tennessee.
(9)Department of Cancer Biology, Vanderbilt University, Nashville, Tennessee.
Division of Rheumatology and Immunology, Vanderbilt University, Nashville,
Tennessee. Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville,
Tennessee. Department of Cell and Developmental Biology, Vanderbilt University,
Nashville, Tennessee. Veterans Affairs Medical Center, Tennessee Valley
Healthcare System, Nashville, Tennessee. [email protected]. A majority of patients with BRAF-mutated metastatic melanoma respond to therapy
with BRAF inhibitors (BRAFi), but relapses are common owing to acquired
resistance. To unravel BRAFi resistance mechanisms we have performed gene
expression and mass spectrometry based proteome profiling of the sensitive
parental A375 BRAF V600E-mutated human melanoma cell line and of daughter cell
lines with induced BRAFi resistance. Increased expression of two novel
resistance candidates, aminopeptidase-N (CD13/ANPEP) and ETS transcription
factor FLI1 was observed in the BRAFi-resistant daughter cell lines. In
addition, increased levels of the previously reported resistance mediators,
receptor tyrosine kinase ephrine receptor A2 (EPHA2) and the hepatocyte growth
factor receptor MET were also identified. The expression of these proteins was
assessed in matched tumor samples from melanoma patients obtained before BRAFi
and after disease progression. MET was overexpressed in all progression samples
while the expression of the other candidates varied between the individual
patients. Targeting CD13/ANPEP by a blocking antibody induced apoptosis in both
parental A375- and BRAFi-resistant daughter cells as well as in melanoma cells
with intrinsic BRAFi resistance and led to dephosphorylation of EPHA2 on S897,
previously demonstrated to cause inhibition of the migratory capacity. AKT and
RSK, both reported to induce EPHA2 S897 phosphorylation, were also
dephosphorylated after inhibition of CD13/ANPEP. FLI1 silencing also caused
decreases in EPHA2 S897 phosphorylation and in total MET protein expression. In
addition, silencing of FLI1 sensitized the resistant cells to BRAFi.
Furthermore, we show that BRAFi in combination with the multi kinase inhibitor
dasatinib can abrogate BRAFi resistance and decrease both EPHA2 S897
phosphorylation and total FLI1 protein expression. This is the first report
presenting CD13/ANPEP and FLI1 as important mediators of resistance to BRAF
inhibition with potential as drug targets in BRAFi refractory melanoma. Aberrant expression of different family members of the Eph/ephrin system, which
comprises the Eph receptors (Ephs) and their ligands (ephrins), has been
implicated in various maligcies including breast cancer. The latter presents
as a heterogeneous disease with diverse molecular, morphologic and clinical
behavior signatures. This review reflects the existing Eph/ephrin literature
while focusing on breast cancer heterogeneity. Hormone positive, HER2 positive
and triple negative breast cancer (TNBC) cell lines, xenografts/mutant animal
models and patient samples are examined separately as, in humans, they represent
entities with differences in prognosis and treatment. EphA2, EphB4 and EphB6 are
the members most extensively studied in breast cancer. Existing research points
to the potential use of various Eph/ephrin members as biomarkers for assessing
prognosis and selecting the most suitable therapeutic strategies in variable
clinical scenarios, also for overcoming drug resistance, in the era of breast
cancer heterogeneity. |
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.