23 research outputs found
The histone acetyl transferases CBP and p300 regulate stress response pathways in synovial fibroblasts at transcriptional and functional levels.
The activation of stress response pathways in synovial fibroblasts (SF) is a hallmark of rheumatoid arthritis (RA). CBP and p300 are two highly homologous histone acetyl transferases and writers of activating histone 3 lysine 27 acetylation (H3K27ac) marks. Furthermore, they serve as co-factors for transcription factors and acetylate many non-histone proteins. Here we showed that p300 but not CBP protein expression was down regulated by TNF and 4-hydroxynonenal, two factors that mimic inflammation and oxidative stress in the synovial microenvironment. We used existing RNA-sequencing data sets as a basis for a further in-depth investigation of individual functions of CBP and p300 in regulating different stress response pathways in SF. Pathway enrichment analysis pointed to a profound role of CBP and/ or p300 in regulating stress response-related gene expression, with an enrichment of pathways associated with oxidative stress, hypoxia, autophagy and proteasome function. We silenced CBP or p300, and performed confirmatory experiments on transcriptome, protein and functional levels. We have identified some overlap of CBP and p300 target genes in the oxidative stress response pathway, however, with several genes being regulated in opposite directions. The majority of stress response genes was regulated by p300, with a specific function of p300 in regulating hypoxia response genes and genes encoding proteasome subunits. Silencing of p300 suppressed proteasome enzymatic activities. CBP and p300 regulated autophagy on transcriptome and functional levels. Whereas CBP was indispensable for autophagy synthesis, silencing of p300 affected late-stage autophagy. In line with impaired autophagy and proteasome function, poly-ubiquitinated proteins accumulated after silencing of p300
The histone acetyl transferases CBP and p300 regulate stress response pathways in synovial fibroblasts at transcriptional and functional levels
The activation of stress response pathways in synovial fibroblasts (SF) is a hallmark of rheumatoid arthritis (RA). CBP and p300 are two highly homologous histone acetyl transferases and writers of activating histone 3 lysine 27 acetylation (H3K27ac) marks. Furthermore, they serve as co-factors for transcription factors and acetylate many non-histone proteins. Here we showed that p300 but not CBP protein expression was down regulated by TNF and 4-hydroxynonenal, two factors that mimic inflammation and oxidative stress in the synovial microenvironment. We used existing RNA-sequencing data sets as a basis for a further in-depth investigation of individual functions of CBP and p300 in regulating different stress response pathways in SF. Pathway enrichment analysis pointed to a profound role of CBP and/ or p300 in regulating stress response-related gene expression, with an enrichment of pathways associated with oxidative stress, hypoxia, autophagy and proteasome function. We silenced CBP or p300, and performed confirmatory experiments on transcriptome, protein and functional levels. We have identified some overlap of CBP and p300 target genes in the oxidative stress response pathway, however, with several genes being regulated in opposite directions. The majority of stress response genes was regulated by p300, with a specific function of p300 in regulating hypoxia response genes and genes encoding proteasome subunits. Silencing of p300 suppressed proteasome enzymatic activities. CBP and p300 regulated autophagy on transcriptome and functional levels. Whereas CBP was indispensable for autophagy synthesis, silencing of p300 affected late-stage autophagy. In line with impaired autophagy and proteasome function, poly-ubiquitinated proteins accumulated after silencing of p300
BRD3 Regulates the Inflammatory and Stress Response in Rheumatoid Arthritis Synovial Fibroblasts
BACKGROUND
Individual functions of members of the bromodomain (BRD) and extra-terminal (BET) protein family underlying the anti-inflammatory effects of BET inhibitors in rheumatoid arthritis (RA) are incompletely understood. Here, we aimed to analyze the regulatory functions of BRD3, an understudied member of the BET protein family, in RA synovial fibroblasts (FLS).
METHODS
BRD3 was silenced in FLS prior to stimulation with TNF. Alternatively, FLS were treated with I-BET. Transcriptomes were analyzed by RNA sequencing (RNAseq), followed by pathway enrichment analysis. We confirmed results for selective target genes by real-time PCR, ELISA, and Western blotting.
RESULTS
BRD3 regulates the expression of several cytokines and chemokines in FLS, and positively correlates with inflammatory scores in the RA synovium. In addition, RNAseq pointed to a profound role of BRD3 in regulating FLS proliferation, metabolic adaption, and response to stress, including oxidative stress, and autophagy.
CONCLUSIONS
BRD3 acts as an upstream regulatory factor that integrates the response to inflammatory stimuli and stress conditions in FLS and executes many functions of BET proteins that have previously been identified using pan-BET inhibitors
ASSOCIATION OF THE GLUCOCORTICOID RECEPTOR GENE POLYMORPHISMS AND THEIR INTERACTION WITH STRESSFUL LIFE EVENTS IN POLISH ADOLESCENT GIRLS WITH ANOREXIA NERVOSA
Background: Disturbances in stress response mechanisms and hypothalamic-pituitary-adrenal axis (HPA) functioning are
considered important factors involved in the pathophysiology of anorexia nervosa (AN). Thus, genetic variations in the end effector
of HPA - glucocorticoid receptor gene and relationships to stressful life events (SLE) may be connected to a higher risk of illness.
The aim of the study was examining the association between glucocorticoid receptor gene (NR3C1) polymorphisms and risk factors
among stressful life events in AN patients.
Subjects and methods: This study comprised 256 patients with AN and 167 control subjects. The questionnaires examining brief
history of the mother’s pregnancy and long-acting stress factors, as well as life events checklist to assess stressful life events during
the 6 months prior to hospitalization were used. The eight common SNPs (rs6198, rs6191, rs6196, rs258813, rs33388, rs41423247,
rs56149945 and rs10052957) of NR3C1 gene were genotyped.
Results: The association of five polymorphisms (rs6191, rs258813, rs33388, rs41423247 and rs10052957) and one complex
allele (TCAGT) of NR3C1 gene with increased risk of AN were found. However, no significant correlations between early, longacting
and predicting hospitalization SLE and any of the analyzed polymorphisms were observed.
Conclusions: The results confirm that the NR3C1 gene is associated with AN risk regardless of the type of stressful triggering
factors
Catechol-O-Methyltransferase Val158Met Polymorphism and Clinical Response to Antipsychotic Treatment in Schizophrenia and Schizo-Affective Disorder Patients: a Meta-Analysis
BACKGROUND:
The catechol-O-methyltransferase (COMT) enzyme plays a crucial role in dopamine degradation, and the COMT Val158Met polymorphism (rs4680) is associated with significant differences in enzymatic activity and consequently dopamine concentrations in the prefrontal cortex. Multiple studies have analyzed the COMT Val158Met variant in relation to antipsychotic response. Here, we conducted a meta-analysis examining the relationship between COMT Val158Met and antipsychotic response.
METHODS:
Searches using PubMed, Web of Science, and PsycInfo databases (03/01/2015) yielded 23 studies investigating COMT Val158Met variation and antipsychotic response in schizophrenia and schizo-affective disorder. Responders/nonresponders were defined using each study's original criteria. If no binary response definition was used, authors were asked to define response according to at least 30% Positive and Negative Syndrome Scale score reduction (or equivalent in other scales). Analysis was conducted under a fixed-effects model.
RESULTS:
Ten studies met inclusion criteria for the meta-analysis. Five additional antipsychotic-treated samples were analyzed for Val158Met and response and included in the meta-analysis (ntotal=1416). Met/Met individuals were significantly more likely to respond than Val-carriers (P=.039, ORMet/Met=1.37, 95% CI: 1.02-1.85). Met/Met patients also experienced significantly greater improvement in positive symptoms relative to Val-carriers (P=.030, SMD=0.24, 95% CI: 0.024-0.46). Posthoc analyses on patients treated with atypical antipsychotics (n=1207) showed that Met/Met patients were significantly more likely to respond relative to Val-carriers (P=.0098, ORMet/Met=1.54, 95% CI: 1.11-2.14), while no difference was observed for typical-antipsychotic-treated patients (n=155) (P=.65).
CONCLUSIONS:
Our findings suggest that the COMT Val158Met polymorphism is associated with response to antipsychotics in schizophrenia and schizo-affective disorder patients. This effect may be more pronounced for atypical antipsychotics.C.C.Z. is supported by the Brain and Behavior Research Foundation, American Foundation for Suicide Prevention and Eli Lilly. D.F. is supported by the Vanier Canada Graduate Scholarship. D.J.M. has been or is supported by the Canadian Institute of Health Research (CIHR) Operating Grant: “Genetics of antipsychotic-induced metabolic syndrome,” Michael Smith New Investigator Salary Prize for Research in Schizophrenia, NARSAD Independent Investigator Award by the Brain & Behavior Research Foundation, and Early Researcher Award from Ministry of Research and Innovation of Ontario. E.H. is supported by the Canada Graduate Scholarship. H.Y.M. has grant support from Sumitomo Dainippon, Sunovion, Boehringer Ingelheim, Eli Lilly, Janssen, Reviva, Alkermes, Auspex, and FORUM. J.A.L. has received research funding from Alkermes, Biomarin, EnVivo/Forum, Genentech, and Novartis. J.L.K. is supported the CIHR grant “Strategies for gene discovery in schizophrenia: subphenotypes, deep sequencing and interaction.” J.R.B. is supported by NIH grant MH083888. A.K.T. is supported by a NARSAD Young Investigator Award. J.S. is supported by a Pfizer independent grant. P.M. receives salary from Clinica Universidad de Navarra and has received research grants from the Ministry of Education (Spain), the Government of Navarra (Spain), the Spanish Foundation of Psychiatry and Mental Health, and Astrazeneca. S.G. is supported by the Ningbo Medical Technology Project Fund (No. 2004050), the Natural Science Foundation of Ningbo (No. 2009A610186, No. 2013A610249), and the Zhejiang Provincial Medical and Health Project Fund (No. 2015127713). S.G.P. has received research support from Otsuka, Lundbeck, FORUM, and Alkermes
Reply to: The potential and challenges of radiomics in uncovering prognostic and molecular differences in interstitial lung disease associated with systemic sclerosis
We thank L. Zhang and co-workers for their correspondence regarding our manuscript. In interstitial lung disease associated with systemic sclerosis (SSc-ILD), the lack of valid prognostic biomarkers hampers individualised patient management. Our study introduces radiomics as a novel non-invasive tool to acquire phenotypic, prognostic and molecular information derived from standard-of-care high-resolution computed tomography images with great potential to support clinical decision making in SSc-ILD [1]
BRD3 Regulates the Inflammatory and Stress Response in Rheumatoid Arthritis Synovial Fibroblasts.
BACKGROUND
Individual functions of members of the bromodomain (BRD) and extra-terminal (BET) protein family underlying the anti-inflammatory effects of BET inhibitors in rheumatoid arthritis (RA) are incompletely understood. Here, we aimed to analyze the regulatory functions of BRD3, an understudied member of the BET protein family, in RA synovial fibroblasts (FLS).
METHODS
BRD3 was silenced in FLS prior to stimulation with TNF. Alternatively, FLS were treated with I-BET. Transcriptomes were analyzed by RNA sequencing (RNAseq), followed by pathway enrichment analysis. We confirmed results for selective target genes by real-time PCR, ELISA, and Western blotting.
RESULTS
BRD3 regulates the expression of several cytokines and chemokines in FLS, and positively correlates with inflammatory scores in the RA synovium. In addition, RNAseq pointed to a profound role of BRD3 in regulating FLS proliferation, metabolic adaption, and response to stress, including oxidative stress, and autophagy.
CONCLUSIONS
BRD3 acts as an upstream regulatory factor that integrates the response to inflammatory stimuli and stress conditions in FLS and executes many functions of BET proteins that have previously been identified using pan-BET inhibitors
Individual functions of the histone acetyl transferases CBP and p300 in regulating the inflammatory response of synovial fibroblasts.
Chromatin remodeling, and a persistent histone 3 lysine 27 acetylation (H3K27ac) in particular, are associated with a sustained inflammatory response of synovial fibroblasts (SF) in rheumatoid arthritis (RA). Here we investigated individual functions of the writers of H3K27ac marks, the homologues histone acetyl transferases (HAT) CBP and p300, in controlling the constitutive and inflammatory gene expression in RA SF. We applied a silencing strategy, followed by RNA-sequencing and pathway analysis, complemented with the treatment of SF with inhibitors targeting the HAT (C646) or bromo domains (I-CBP) of CBP and p300. We showed that CBP and p300 undertook overlapping and, in particular at gene levels, distinct regulatory functions in SF. p300 is the major HAT for H3K27ac in SF and regulated more diverse pathways than CBP. Whereas both factors regulated genes associated with extracellular matrix remodeling, adhesion and proliferation, p300 specifically controlled developmental genes associated with limb development. Silencing of CBP specifically down regulated the TNF-induced expression of interferon-signature genes. In contrast, silencing of p300 resulted in anti- and pro-inflammatory effects. Integration of data sets derived from RNA-sequencing and chromatin immunoprecipitation sequencing for H3K27ac revealed that changes in gene expression after CBP or p300 silencing could be only partially explained by changes in levels of H3K27ac. Inhibition of CBP/p300 using HAT and bromo domain inhibitors strongly mirrored effects obtained by silencing of p300, including anti- and pro-inflammatory effects, indicating that such inhibitors are not sufficient to be used as anti-inflammatory drugs