1 5556 119 ROLE OF FLUORIDE INDUCED HISTONE TRIMETHYLATION IN DEVELOPMENT OF SKELETAL FLUOROSIS. CHRONIC EXPOSURE TO FLUORIDE HAS BEEN ASSOCIATED WITH THE DEVELOPMENT OF SKELETAL FLUOROSIS. LIMITED REPORTS ARE AVAILABLE ON FLUORIDE INDUCED HISTONE MODIFICATION. HOWEVER, THE ROLE OF HISTONE MODIFICATION IN THE PATHOGENESIS OF SKELETAL FLUOROSIS IS NOT INVESTIGATED. IN THE PRESENT STUDY, WE HAVE INVESTIGATED THE ROLE OF FLUORIDE INDUCED HISTONE MODIFICATION ON FLUOROSIS DEVELOPMENT USING HUMAN OSTEOSARCOMA (HOS) CELL LINE. THE EXPRESSION OF HISTONE METHYLTRANSFERASES (EHMT1 AND EHZ2) AND LEVEL OF GLOBAL HISTONE TRIMETHYLATION (H3K9 AND H3K27) HAVE BEEN ASSESSED AND OBSERVED TO BE INCREASED SIGNIFICANTLY AFTER FLUORIDE EXPOSURE (8 MG/L). EPITECT CHROMATIN IMMUNOPRECIPITATION (CHIP) QPCR ARRAY (HUMAN TGFBETA/BMP SIGNALING PATHWAY) WAS PERFORMED TO ASSESS THE H3K9 TRIMETHYLATION AT PROMOTER REGIONS OF PATHWAY-SPECIFIC GENES. H3K9 CHIP PCR ARRAY ANALYSIS IDENTIFIED HYPER H3K9 TRIMETHYLATION IN PROMOTER REGIONS OF TGFBR2 AND SMAD3. QPCR AND STRING ANALYSIS WAS CARRIED OUT TO DETERMINE THE REPRESSIVE EPIGENETIC EFFECT OF H3K9 TRIMETHYLATION ON EXPRESSION PATTERN AND FUNCTIONAL ASSOCIATION OF IDENTIFIED GENES. IDENTIFIED GENES (TGFBR2 AND SMAD3) SHOWED DOWN-REGULATION WHICH CONFIRMS THE REPRESSIVE EPIGENETIC EFFECT OF PROMOTER H3K9 HYPER TRIMETHYLATION. EXPRESSION OF TWO OTHER VITAL GENES COL1A1 AND MMP13 INVOLVED IN TGFBR2-SMAD SIGNALING PATHWAY WAS ALSO FOUND TO BE DOWN-REGULATED WITH A DECREASE IN EXPRESSION OF TGFBR2 AND SMAD3. STRING ANALYSIS REVEALED FUNCTIONAL ASSOCIATION AND INVOLVEMENT OF IDENTIFIED GENES TGFBR2, SMAD3, COL1A1 AND MMP13 IN THE COLLAGEN AND CARTILAGE DEVELOPMENT/MORPHOGENESIS, CONNECTIVE TISSUE FORMATION, BIO-MINERAL TISSUE DEVELOPMENT, ENDOCHONDRAL BONE FORMATION, BONE AND SKELETAL MORPHOGENESIS. IN CONCLUSION, PRESENT INVESTIGATION IS A FIRST ATTEMPT TO LINK FLUORIDE INDUCED HYPER H3K9 TRI-METHYLATION MEDIATED REPRESSION OF TGFBR2 AND SMAD3 WITH THE DEVELOPMENT OF SKELETAL FLUOROSIS. 2018 2 5555 47 ROLE OF FLUORIDE INDUCED EPIGENETIC ALTERATIONS IN THE DEVELOPMENT OF SKELETAL FLUOROSIS. FLUORIDE IS AN ESSENTIAL TRACE ELEMENT REQUIRED FOR PROPER BONE AND TOOTH DEVELOPMENT. SYSTEMIC HIGH EXPOSURE TO FLUORIDE THROUGH ENVIRONMENTAL EXPOSURE (DRINKING WATER AND FOOD) MAY RESULT IN TOXICITY CAUSING A DISORDER CALLED FLUOROSIS. IN THE PRESENT STUDY, WE INVESTIGATED THE ALTERATION IN DNA METHYLATION PROFILE WITH CHRONIC EXPOSURE (30 DAYS) TO FLUORIDE (8 MG/L) AND ITS RELEVANCE IN THE DEVELOPMENT OF FLUOROSIS. WHOLE GENOME BISULFITE SEQUENCING (WGBS) WAS CARRIED OUT IN HUMAN OSTEOSARCOMA CELLS (HOS) EXPOSED TO FLUORIDE. WHOLE GENOME BISULFITE SEQUENCING (WGBS) AND FUNCTIONAL ANNOTATION OF DIFFERENTIALLY METHYLATED GENES INDICATE ALTERATIONS IN METHYLATION STATUS OF GENES INVOLVED IN BIOLOGICAL PROCESSES ASSOCIATED WITH BONE DEVELOPMENT PATHWAYS. COMBINED ANALYSIS OF PROMOTER DNA HYPER METHYLATION, STRING: FUNCTIONAL PROTEIN ASSOCIATION NETWORKS AND GENE EXPRESSION ANALYSIS REVEALED EPIGENETIC ALTERATIONS IN BMP1, METAP2, MMP11 AND BACH1 GENES, WHICH PLAYS A ROLE IN THE EXTRACELLULAR MATRIX DISASSEMBLY, COLLAGEN CATABOLIC/ORGANIZATION PROCESS, SKELETAL MORPHOGENESIS/DEVELOPMENT, OSSIFICATION AND OSTEOBLAST DEVELOPMENT. THE PRESENT STUDY SHOWS THAT FLUORIDE CAUSES PROMOTER DNA HYPERMETHYLATION IN BMP1, METAP2, MMP11 AND BACH1 GENES WITH SUBSEQUENT DOWN-REGULATION IN THEIR EXPRESSION LEVEL (RNA LEVEL). THE RESULTS IMPLIES THAT FLUORIDE INDUCED DNA HYPERMETHYLATION OF THESE GENES MAY HAMPER EXTRACELLULAR MATRIX DEPOSITION, CARTILAGE FORMATION, ANGIOGENESIS, VASCULAR SYSTEM DEVELOPMENT AND POROSITY OF BONE, THUS PROMOTE SKELETAL FLUOROSIS. 2019 3 908 40 CHRONIC EXPOSURE TO ENVIRONMENTALLY RELEVANT CONCENTRATION OF FLUORIDE IMPAIRS OSTEOBLAST'S COLLAGEN SYNTHESIS AND MATRIX MINERALIZATION: INVOLVEMENT OF EPIGENETIC REGULATION IN SKELETAL FLUOROSIS. GLOBALLY, 200 MILLION PEOPLE ARE SUFFERING FROM TOXIC MANIFESTATIONS OF FLUORIDE(F), DENTAL AND SKELETAL FLUOROSIS; UNFORTUNATELY, THERE IS NO TREATMENT. TO UNRAVEL THE PATHOGENESIS OF SKELETAL FLUOROSIS, WE ESTABLISHED FLUOROSIS MICE BY TREATING ENVIRONMENTALLY RELEVANT CONCENTRATION OF F (15 PPM NAF) THROUGH DRINKING WATER FOR 4 MONTHS. AS IN SKELETAL FLUOROSIS, LOCOMOTOR DISABILITY, CRIPPLING DEFORMITIES OCCUR AND THUS, OUR HYPOTHESIS WAS F MIGHT ADVERSELY AFFECTS COLLAGEN WHICH GIVES THE BONE TENSILE STRENGTH. THIS WORK INEVITABLY HAD TO BE CARRIED OUT ON OSTEOBLAST CELLS, RESPONSIBLE FOR SYNTHESIS, DEPOSITION, AND MINERALIZATION OF BONE MATRIX. ISOLATED OSTEOBLAST CELLS WERE CONFIRMED BY ALP ACTIVITY AND MINERALIZED NODULES FORMATION. EXPRESSION OF COLLAGEN COL1A1, COL1A2, COL1A1 WAS SIGNIFICANTLY REDUCED IN TREATED MICE. FURTHER, A STUDY REVEALED THE INVOLVEMENT OF EPIGENETIC REGULATION BY PROMOTER HYPERMETHYLATION OF COL1A1; EXPRESSIONAL ALTERATIONS OF TRANSCRIPTION FACTORS, CALCIUM CHANNELS AND OTHER GENES E.G., CBFA-1, TGF-BETA1, BMP1, SP1, SP7, NF-(K)B P65, BMP-2, BGLAP, GPRC6A AND CAV(1.2) ARE ASSOCIATED WITH IMPAIRMENT OF COLLAGEN SYNTHESIS, DEPOSITION AND DECREASED MINERALIZATION THUS, ENFEEBLING BONE HEALTH. THIS STUDY INDICATES THE POSSIBLE ASSOCIATION OF EPIGENETIC REGULATION IN SKELETAL FLUOROSIS. HOWEVER, NO ASSOCIATION WAS FOUND BETWEEN POLYMORPHISMS IN THE COL1A1 (RSAI, HINDIII) AND COL1A2 (RSAI, HINDIII) GENES WITH FLUOROSIS IN MICE. 2023 4 1144 41 CONCOMITANT HETEROCHROMATINISATION AND DOWN-REGULATION OF GENE EXPRESSION UNVEILS EPIGENETIC SILENCING OF RELB IN AN AGGRESSIVE SUBSET OF CHRONIC LYMPHOCYTIC LEUKEMIA IN MALES. BACKGROUND: THE SENSITIVITY OF CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) CELLS TO CURRENT TREATMENTS, BOTH IN VITRO AND IN VIVO, RELIES ON THEIR ABILITY TO ACTIVATE APOPTOTIC DEATH. CLL CELLS RESISTANT TO DNA DAMAGE-INDUCED APOPTOSIS DISPLAY DEREGULATION OF A SPECIFIC SET OF GENES. METHODS: MICROARRAY HYBRIDIZATION (HUMAN GENECHIP, AFFYMETRIX), IMMUNOFLUORESCENT IN SITU LABELING COUPLED WITH VIDEO-MICROSCOPY RECORDING/ANALYSES, CHROMATIN-IMMUNOPRECIPITATION (CHIP), POLYMERASE CHAIN REACTIONS (PCR), REAL-TIME QUANTITATIVE PCR (RT-QPCR) AND BISULFITE GENOME SEQUENCING WERE THE MAIN METHODS APPLIED. STATISTICAL ANALYSES WERE PERFORMED BY APPLYING GCRMA AND SAM ANALYSIS (MICROARRAY DATA) AND STUDENT'S T-TEST OR MANN & WHITNEY'S U-TEST. RESULTS: HEREIN WE SHOW THAT, REMARKABLY, IN A RESISTANT MALE CLL CELLS THE VAST MAJORITY OF GENES WERE DOWN-REGULATED COMPARED WITH SENSITIVE CELLS, WHEREAS THIS WAS NOT THE CASE IN CELLS DERIVED FROM FEMALES. THIS GENE DOWN-REGULATION WAS FOUND TO BE ASSOCIATED WITH AN OVERALL GAIN OF HETEROCHROMATIN AS EVIDENCED BY IMMUNOFLUORESCENT LABELING OF HETEROCHROMATIN PROTEIN 1ALPHA (HP-1), TRIMETHYLATED HISTONE 3 LYSINE 9 (3METH3K9), AND 5-METHYLCYTIDINE (5METC). NOTABLY, 17 GENES WERE FOUND TO BE COMMONLY DEREGULATED IN RESISTANT MALE AND FEMALE CELL SAMPLES. AMONG THESE, RELB WAS IDENTIFIED AS A DISCRIMINATORY CANDIDATE GENE REPRESSED IN THE MALE AND UPREGULATED IN THE FEMALE RESISTANT CELLS. CONCLUSION: THE MOLECULAR DEFECTS IN THE SILENCING OF RELB INVOLVE AN INCREASE IN H3K9- BUT NOT CPG-ISLAND METHYLATION IN THE PROMOTER REGIONS. INCREASE IN ACETYL-H3 IN RESISTANT FEMALE BUT NOT MALE CLL SAMPLES AS WELL AS A DECREASE OF TOTAL CELLULAR LEVEL OF RELB AFTER AN INHIBITION OF HISTONE DEACETYLASE (HDAC) BY TRICHOSTATIN A (TSA), FURTHER EMPHASIZE THE ROLE OF EPIGENETIC MODIFICATIONS WHICH COULD DISCRIMINATE TWO CLL SUBSETS. TOGETHER, THESE RESULTS HIGHLIGHTED THE EPIGENETIC RELB SILENCING AS A NEW MARKER OF THE PROGRESSIVE DISEASE IN MALES. 2010 5 2395 40 EPIGENETIC REPROGRAMMING IN MIST1(-/-) MICE PREDICTS THE MOLECULAR RESPONSE TO CERULEIN-INDUCED PANCREATITIS. GENE EXPRESSION IS AFFECTED BY MODIFICATIONS TO HISTONE CORE PROTEINS WITHIN CHROMATIN. CHANGES IN THESE MODIFICATIONS, OR EPIGENETIC REPROGRAMMING, CAN DICTATE CELL FATE AND PROMOTE SUSCEPTIBILITY TO DISEASE. THE GOAL OF THIS STUDY WAS TO DETERMINE THE EXTENT OF EPIGENETIC REPROGRAMMING IN RESPONSE TO CHRONIC STRESS THAT OCCURS FOLLOWING ABLATION OF MIST1 (MIST1(-/-) ), WHICH IS REPRESSED IN PANCREATIC DISEASE. CHROMATIN IMMUNOPRECIPITATION FOR TRIMETHYLATION OF LYSINE RESIDUE 4 ON HISTONE 3 (H3K4ME3) IN PURIFIED ACINAR CELLS FROM WILD TYPE AND MIST1(-/-) MICE WAS FOLLOWED BY NEXT GENERATION SEQUENCING (CHIP-SEQ) OR CHIP-QPCR. H3K4ME3-ENRICHED GENES WERE ASSESSED FOR EXPRESSION BY QRT-PCR IN PANCREATIC TISSUE BEFORE AND AFTER INDUCTION OF CERULEIN-INDUCED PANCREATITIS. WHILE MOST OF H3K4ME3-ENRICHMENT IS RESTRICTED TO TRANSCRIPTIONAL START SITES, >25% OF ENRICHMENT SITES ARE FOUND WITHIN, DOWNSTREAM OR BETWEEN ANNOTATED GENES. LESS THAN 10% OF THESE SITES WERE ALTERED IN MIST1(-/-) ACINI, WITH MOST CHANGES IN H3K4ME3 ENRICHMENT NOT REFLECTING ALTERED GENE EXPRESSION. INGENUITY PATHWAY ANALYSIS OF GENES DIFFERENTIALLY-ENRICHED FOR H3K4ME3 REVEALED AN ASSOCIATION WITH PANCREATITIS AND PANCREATIC DUCTAL ADENOCARCINOMA IN MIST1(-/-) TISSUE. MOST OF THESE GENES WERE NOT DIFFERENTIALLY EXPRESSED BUT SEVERAL WERE READILY INDUCED BY ACUTE EXPERIMENTAL PANCREATITIS, WITH SIGNIFICANTLY INCREASED EXPRESSION IN MIST1(-/-) TISSUE RELATIVE TO WILD TYPE MICE. WE SUGGEST THAT THE CHRONIC CELL STRESS OBSERVED IN THE ABSENCE OF MIST1 RESULTS IN EPIGENETIC REPROGRAMMING OF GENES INVOLVED IN PROMOTING PANCREATITIS TO A POISED STATE, THEREBY INCREASING THE SENSITIVITY TO EVENTS THAT PROMOTE DISEASE. 2014 6 3658 36 INDUCTION OF ABERRANT TRIMETHYLATION OF HISTONE H3 LYSINE 27 BY INFLAMMATION IN MOUSE COLONIC EPITHELIAL CELLS. A FIELD FOR CANCERIZATION (FIELD DEFECT), WHERE GENETIC AND EPIGENETIC ALTERATIONS ARE ACCUMULATED IN NORMAL-APPEARING TISSUES, IS INVOLVED IN HUMAN CARCINOGENESIS, ESPECIALLY CANCERS ASSOCIATED WITH CHRONIC INFLAMMATION. ALTHOUGH ABERRANT DNA METHYLATION IS INVOLVED IN THE FIELD DEFECT AND INDUCED BY CHRONIC INFLAMMATION, IT IS STILL UNCLEAR FOR TRIMETHYLATION OF HISTONE H3 LYSINE 27 (H3K27ME3), WHICH IS INVOLVED IN GENE REPRESSION INDEPENDENT OF DNA METHYLATION AND FUNCTIONS AS A PRE-MARK FOR ABERRANT DNA METHYLATION. IN THIS STUDY, USING A MOUSE COLITIS MODEL INDUCED BY DEXTRAN SULFATE SODIUM (DSS), WE AIMED TO CLARIFY WHETHER ABERRANT H3K27ME3 IS INDUCED BY INFLAMMATION AND INVOLVED IN A FIELD DEFECT. CHIP-ON-CHIP ANALYSIS OF COLONIC EPITHELIAL CELLS REVEALED THAT H3K27ME3 LEVELS WERE INCREASED OR DECREASED FOR 266 GENOMIC REGIONS BY AGING, AND MORE EXTENSIVELY (23 INCREASED AND 3574 DECREASED REGIONS) BY COLITIS. SUCH INCREASE OR DECREASE OF H3K27ME3 WAS INDUCED AS EARLY AS 2 WEEKS AFTER THE INITIATION OF DSS TREATMENT, AND PERSISTED AT LEAST FOR 16 WEEKS EVEN AFTER THE INFLAMMATION DISAPPEARED. SOME OF THE ABERRANT H3K27ME3 IN COLONIC EPITHELIAL CELLS WAS CARRIED OVER INTO COLON TUMORS. FURTHERMORE, H3K27ME3 ACQUIRED AT DAPK1 BY COLITIS WAS FOLLOWED BY INCREASED DNA METHYLATION, SUPPORTING ITS FUNCTION AS A PRE-MARK FOR ABERRANT DNA METHYLATION. THESE RESULTS DEMONSTRATED THAT ABERRANT H3K27ME3 CAN BE INDUCED BY EXPOSURE TO A SPECIFIC ENVIRONMENT, SUCH AS COLITIS, AND SUGGESTED THAT ABERRANT HISTONE MODIFICATION, IN ADDITION TO ABERRANT DNA METHYLATION, IS INVOLVED IN THE FORMATION OF A FIELD DEFECT. 2012 7 6411 34 THE SITE SPECIFIC DEMETHYLATION IN THE 5'-REGULATORY AREA OF NMDA RECEPTOR 2B SUBUNIT GENE ASSOCIATED WITH CIE-INDUCED UP-REGULATION OF TRANSCRIPTION. BACKGROUND: THE NMDA RECEPTOR REPRESENTS A PARTICULARLY IMPORTANT SITE OF ETHANOL ACTION IN THE CNS. WE RECENTLY REPORTED THAT NMDA RECEPTOR 2B (NR2B) GENE EXPRESSION WAS PERSISTENTLY UP-REGULATED FOLLOWING CHRONIC INTERMITTENT ETHANOL (CIE) TREATMENT. INCREASING EVIDENCE THAT EPIGENETIC MECHANISMS ARE INVOLVED IN DYNAMIC AND LONG-LASTING REGULATION OF GENE EXPRESSION IN MULTIPLE NEUROADAPTIVE PROCESSES PROMPTED US TO INVESTIGATE THE ROLE OF DNA METHYLATION IN MEDIATING CIE-INDUCED UP-REGULATION OF NR2B GENE TRANSCRIPTION. TO DISSECT THE CHANGES OF DNA METHYLATION IN THE NR2B GENE, WE HAVE SCREENED A LARGE NUMBER OF CPG SITES WITHIN ITS 5'-REGULATORY AREA FOLLOWING CIE TREATMENT. METHODS: PRIMARY CORTICAL CULTURED NEURONS WERE SUBJECTED TO ETHANOL TREATMENT IN A CIE PARADIGM. BISULFITE CONVERSION FOLLOWED BY PYROSEQUENCING WAS USED FOR QUANTITATIVE MEASUREMENT AND ANALYSIS OF CPG METHYLATION STATUS WITHIN THE 5'-REGULATORY AREA OF THE NR2B GENE; CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY WAS USED TO EXAMINE DNA LEVELS ASSOCIATED WITH METHYLATION AND TRANSCRIPTION FACTOR BINDING. ELECTROPHORETIC MOBILITY SHIFT ASSAY (EMSA) AND IN VITRO DNA METHYLATION ASSAYS WERE PERFORMED TO DETERMINE THE DIRECT IMPACT OF DNA METHYLATION ON THE INTERACTION BETWEEN DNA AND TRANSCRIPTION FACTOR AND PROMOTER ACTIVITY. RESULTS: ANALYSIS OF INDIVIDUAL CPG METHYLATION SITES WITHIN THE NR2B 5'REGULATORY AREA REVEALED THREE REGIONS WITH CLUSTERS OF SITE-SPECIFIC CPG DEMETHYLATION FOLLOWING CIE TREATMENT AND WITHDRAWAL. THIS WAS CONFIRMED BY CHIP SHOWING SIMILAR DECREASES OF METHYLATED DNA IN THE SAME REGIONS. THE CIE-INDUCED DEMETHYLATION IS CHARACTERIZED BY BEING LOCATED NEAR CERTAIN TRANSCRIPTION FACTOR BINDING SEQUENCES, AP-1 AND CRE, AND OCCURRED DURING TREATMENT AS WELL AS AFTER ETHANOL WITHDRAWAL. FURTHERMORE, THE INCREASE IN VITRO OF METHYLATED DNA DECREASED TRANSCRIPTION FACTOR BINDING ACTIVITY AND PROMOTER ACTIVITY. AN ADDITIONAL CHIP ASSAY INDICATED THAT THE CIE-INDUCED DNA DEMETHYLATION IS ACCOMPANIED BY INCREASED OCCUPATION BY TRANSCRIPTION FACTORS. CONCLUSIONS: THESE RESULTS SUGGEST AN IMPORTANT ROLE OF DNA DEMETHYLATION IN MEDIATING CIE-INDUCED NR2B GENE UP-REGULATION, THUS IMPLICATING A NOVEL MOLECULAR SITE OF ALCOHOL ACTION. 2010 8 164 30 ABNORMAL HISTONE METHYLATION IS RESPONSIBLE FOR INCREASED VASCULAR ENDOTHELIAL GROWTH FACTOR 165A SECRETION FROM AIRWAY SMOOTH MUSCLE CELLS IN ASTHMA. VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF), A KEY ANGIOGENIC MOLECULE, IS ABERRANTLY EXPRESSED IN SEVERAL DISEASES INCLUDING ASTHMA WHERE IT CONTRIBUTES TO BRONCHIAL VASCULAR REMODELING AND CHRONIC INFLAMMATION. ASTHMATIC HUMAN AIRWAY SMOOTH MUSCLE CELLS HYPERSECRETE VEGF, BUT THE MECHANISM IS UNCLEAR. IN THIS STUDY, WE DEFINED THE MECHANISM IN HUMAN AIRWAY SMOOTH MUSCLE CELLS FROM NONASTHMATIC AND ASTHMATIC PATIENTS. WE FOUND THAT ASTHMATIC CELLS LACKED A REPRESSION COMPLEX AT THE VEGF PROMOTER, WHICH WAS PRESENT IN NONASTHMATIC CELLS. RECRUITMENT OF G9A, TRIMETHYLATION OF HISTONE H3 AT LYSINE 9 (H3K9ME3), AND A RESULTANT DECREASE IN RNA POLYMERASE II AT THE VEGF PROMOTER WAS CRITICAL TO REPRESSION OF VEGF SECRETION IN NONASTHMATIC CELLS. AT THE ASTHMATIC PROMOTER, H3K9ME3 WAS ABSENT BECAUSE OF FAILED RECRUITMENT OF G9A; RNA POLYMERASE II BINDING, IN ASSOCIATION WITH TATA-BINDING PROTEIN-ASSOCIATED FACTOR 1, WAS INCREASED; H3K4ME3 WAS PRESENT; AND SP1 BINDING WAS EXAGGERATED AND SUSTAINED. IN CONTRAST, DNA METHYLATION AND HISTONE ACETYLATION WERE SIMILAR IN ASTHMATIC AND NONASTHMATIC CELLS. THIS IS THE FIRST STUDY, TO OUR KNOWLEDGE, TO SHOW THAT AIRWAY CELLS IN ASTHMA HAVE ALTERED EPIGENETIC REGULATION OF REMODELING GENE(S). HISTONE METHYLATION AT GENES SUCH AS VEGF MAY BE AN IMPORTANT NEW THERAPEUTIC TARGET. 2012 9 4076 32 MATERNAL HIGH-FAT DIET MODIFIES EPIGENETIC MARKS H3K27ME3 AND H3K27AC IN BONE TO REGULATE OFFSPRING OSTEOBLASTOGENESIS IN MICE. STUDIES FROM BOTH HUMANS AND ANIMAL MODELS INDICATED THAT MATERNAL CHRONIC POOR-QUALITY DIET, ESPECIALLY A HIGH FAT DIET (HFD), IS SIGNIFICANTLY ASSOCIATED WITH REDUCED BONE DENSITY AND CHILDHOOD FRACTURES IN OFFSPRING. WHEN PREVIOUSLY STUDIED IN A RAT MODEL, OUR DATA SUGGESTED THAT MATERNAL HFD CHANGES EPIGENETIC MARKS SUCH AS DNA METHYLATION AND HISTONE MODIFICATIONS TO CONTROL OSTEOBLAST METABOLISM. IN MOUSE EMBRYONIC AND POSTNATAL OFFSPRING BONE SAMPLES, A CHIP-SEQUENCING (CHIP-SEQ)-BASED GENOME-WIDE METHOD WAS USED TO LOCATE THE REPRESSIVE HISTONE MARK H3K27ME3 (MEDIATED VIA THE POLYCOMB HISTONE METHYLTRANSFERASE, EZH2) AND EXPRESSIVE HISTONE MARK H3K27AC (P300/CBP MEDIATED) THROUGHOUT THE GENOME. USING ISOLATED MOUSE EMBRYONIC CELLS FROM FOETAL CALVARIA (OSTEOBLAST-LIKE CELLS), H3K27ME3 CHIP-SEQ SHOWED THAT 147 GENE BODIES AND 26 GENE PROMOTERS IN HFD EMBRYOTIC SAMPLES HAD A GREATER THAN TWOFOLD INCREASE IN H3K27ME PEAKS COMPARED TO CONTROLS. AMONG THE HFD SAMPLES, PTHLH AND COL2A1 THAT ARE IMPORTANT GENES PLAYING ROLES DURING CHONDRO- AND OSTEOGENESIS HAD SIGNIFICANTLY ENRICHED LEVELS OF H3K27ME3. THEIR DECREASED MRNA EXPRESSION WAS CONFIRMED BY REAL-TIME PCR AND STANDARD CHIP ANALYSIS, INDICATING A STRONG ASSOCIATION WITH EZH2 MEDIATED H3K27ME3 EPIGENETIC CHANGES. USING EMBRYONIC CALVARIA OSTEOBLASTIC CELLS AND OFFSPRING BONE SAMPLES, H3K27AC CHIP-SEQ ANALYSIS SHOWED THAT OSTEOBLAST INHIBITOR GENES TNFAIP3 AND TWIST1 HAD SIGNIFICANTLY ENRICHED PEAKS OF H3K27AC IN HFD SAMPLES COMPARED TO CONTROLS. THEIR INCREASED GENE EXPRESSION AND ASSOCIATION WITH H3K27AC WERE ALSO CONFIRMED BY REAL-TIME PCR AND STANDARD CHIP ANALYSIS. THESE FINDINGS INDICATE THAT CHRONIC MATERNAL HFD CHANGES HISTONE TRIMETHYLATION AND ACETYLATION EPIGENETIC MARKS TO REGULATE EXPRESSION OF GENES CONTROLLING OSTEOBLASTOGENESIS. 2022 10 5972 27 TET REPRESSION AND INCREASED DNMT ACTIVITY SYNERGISTICALLY INDUCE ABERRANT DNA METHYLATION. CHRONIC INFLAMMATION IS DEEPLY INVOLVED IN VARIOUS HUMAN DISORDERS, SUCH AS CANCER, NEURODEGENERATIVE DISORDERS, AND METABOLIC DISORDERS. INDUCTION OF EPIGENETIC ALTERATIONS, ESPECIALLY ABERRANT DNA METHYLATION, IS ONE OF THE MAJOR MECHANISMS, BUT HOW IT IS INDUCED IS STILL UNCLEAR. HERE, WE FOUND THAT EXPRESSION OF TET GENES, METHYLATION ERASERS, WAS DOWNREGULATED IN INFLAMED MOUSE AND HUMAN TISSUES, AND THAT THIS WAS CAUSED BY UPREGULATION OF TET-TARGETING MIRNAS SUCH AS MIR20A, MIR26B, AND MIR29C, LIKELY DUE TO ACTIVATION OF NF-KAPPAB SIGNALING DOWNSTREAM OF IL-1BETA AND TNF-ALPHA. HOWEVER, TET KNOCKDOWN INDUCED ONLY MILD ABERRANT METHYLATION. NITRIC OXIDE (NO), PRODUCED BY NOS2, ENHANCED ENZYMATIC ACTIVITY OF DNA METHYLTRANSFERASES (DNMTS), METHYLATION WRITERS, AND NO EXPOSURE INDUCED MINIMAL ABERRANT METHYLATION. IN CONTRAST, A COMBINATION OF TET KNOCKDOWN AND NO EXPOSURE SYNERGISTICALLY INDUCED ABERRANT METHYLATION, INVOLVING GENOMIC REGIONS NOT METHYLATED BY EITHER ALONE. THE RESULTS SHOWED THAT A VICIOUS COMBINATION OF TET REPRESSION, DUE TO NF-KAPPAB ACTIVATION, AND DNMT ACTIVATION, DUE TO NO PRODUCTION, IS RESPONSIBLE FOR ABERRANT METHYLATION INDUCTION IN HUMAN TISSUES. 2020 11 3468 43 HYPOXIA-INDUCED DNA HYPERMETHYLATION IN HUMAN PULMONARY FIBROBLASTS IS ASSOCIATED WITH THY-1 PROMOTER METHYLATION AND THE DEVELOPMENT OF A PRO-FIBROTIC PHENOTYPE. BACKGROUND: PULMONARY FIBROSIS IS A DEBILITATING AND LETHAL DISEASE WITH NO EFFECTIVE TREATMENT OPTIONS. UNDERSTANDING THE PATHOLOGICAL PROCESSES AT PLAY WILL DIRECT THE APPLICATION OF NOVEL THERAPEUTIC AVENUES. HYPOXIA HAS BEEN IMPLICATED IN THE PATHOGENESIS OF PULMONARY FIBROSIS YET THE PRECISE MECHANISM BY WHICH IT CONTRIBUTES TO DISEASE PROGRESSION REMAINS TO BE FULLY ELUCIDATED. IT HAS BEEN SHOWN THAT CHRONIC HYPOXIA CAN ALTER DNA METHYLATION PATTERNS IN TUMOUR-DERIVED CELL LINES. THIS EPIGENETIC ALTERATION CAN INDUCE CHANGES IN CELLULAR PHENOTYPE WITH PROMOTER METHYLATION BEING ASSOCIATED WITH GENE SILENCING. OF PARTICULAR RELEVANCE TO IDIOPATHIC PULMONARY FIBROSIS (IPF) IS THE OBSERVATION THAT THY-1 PROMOTER METHYLATION IS ASSOCIATED WITH A MYOFIBROBLAST PHENOTYPE WHERE LOSS OF THY-1 OCCURS ALONGSIDE INCREASED ALPHA SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION. THE INITIAL AIM OF THIS STUDY WAS TO DETERMINE WHETHER HYPOXIA REGULATES DNA METHYLATION IN NORMAL HUMAN LUNG FIBROBLASTS (CCD19LU). AS IT HAS BEEN REPORTED THAT HYPOXIA SUPPRESSES THY-1 EXPRESSION DURING LUNG DEVELOPMENT WE ALSO STUDIED THE EFFECT OF HYPOXIA ON THY-1 PROMOTER METHYLATION AND GENE EXPRESSION. METHODS: CCD19LU WERE GROWN FOR UP TO 8 DAYS IN HYPOXIA AND ASSESSED FOR GLOBAL CHANGES IN DNA METHYLATION USING FLOW CYTOMETRY. REAL-TIME PCR WAS USED TO QUANTIFY EXPRESSION OF THY-1, ALPHA-SMA, COLLAGEN I AND III. GENOMIC DNA WAS BISULPHITE TREATED AND METHYLATION SPECIFIC PCR (MSPCR) WAS USED TO EXAMINE THE METHYLATION STATUS OF THE THY-1 PROMOTER. RESULTS: SIGNIFICANT GLOBAL HYPERMETHYLATION WAS DETECTED IN HYPOXIC FIBROBLASTS RELATIVE TO NORMOXIC CONTROLS AND WAS ACCOMPANIED BY INCREASED EXPRESSION OF MYOFIBROBLAST MARKERS. THY-1 MRNA EXPRESSION WAS SUPPRESSED IN HYPOXIC CELLS, WHICH WAS RESTORED WITH THE DEMETHYLATING AGENT 5-AZA-2'-DEOXYCYTIDINE. MSPCR REVEALED THAT THY-1 BECAME METHYLATED FOLLOWING FIBROBLAST EXPOSURE TO 1% O2. CONCLUSION: THESE DATA SUGGEST THAT GLOBAL AND GENE-SPECIFIC CHANGES IN DNA METHYLATION MAY PLAY AN IMPORTANT ROLE IN FIBROBLAST FUNCTION IN HYPOXIA. 2012 12 1011 25 CIGARETTE SMOKE CONDENSATE INDUCES DIFFERENTIAL EXPRESSION AND PROMOTER METHYLATION PROFILES OF CRITICAL GENES INVOLVED IN LUNG CANCER IN NL-20 LUNG CELLS IN VITRO: SHORT-TERM AND CHRONIC EXPOSURE. ESTABLISHING EARLY DIAGNOSTIC MARKERS OF HARM IS CRITICAL FOR EFFECTIVE PREVENTION PROGRAMS AND REGULATION OF TOBACCO PRODUCTS. THIS STUDY EXAMINED EFFECTS OF CIGARETTE SMOKE CONDENSATE (CSC) ON EXPRESSION AND PROMOTER METHYLATION PROFILE OF CRITICAL GENES (DAPK, ECAD, MGMT, AND RASSF1A) INVOLVED IN LUNG CANCER DEVELOPMENT IN DIFFERENT HUMAN LUNG CELL LINES. NL-20 CELLS WERE TREATED WITH 0.1-100 MUG/ML OF CSC FOR 24 TO 72 HRS FOR SHORT-TERM EXPOSURES. DAPK EXPRESSION OR METHYLATION STATUS WAS NOT SIGNIFICANTLY AFFECTED. HOWEVER, CSC TREATMENT RESULTED IN CHANGES IN EXPRESSION AND PROMOTER METHYLATION PROFILE OF ECAD, MGMT, AND RASSF1A. FOR CHRONIC STUDIES, CELLS WERE EXPOSED TO 1 OR 10 MUG/ML CSC UP TO 28 DAYS. CELLS SHOWED MORPHOLOGICAL CHANGES ASSOCIATED WITH TRANSFORMATION AND CHANGES IN INVASION CAPACITIES AND GLOBAL METHYLATION STATUS. THIS STUDY PROVIDES CRITICAL DATA SUGGESTING THAT EPIGENETIC CHANGES COULD SERVE AS AN EARLY BIOMARKER OF HARM DUE TO EXPOSURE TO CIGARETTE SMOKE. 2013 13 4742 29 NOVEL HISTONE MODIFICATIONS IN MICROGLIA DERIVED FROM A MOUSE MODEL OF CHRONIC PAIN. AS THE RESIDENT IMMUNE CELLS IN THE CENTRAL NERVOUS SYSTEM, MICROGLIA PLAY AN IMPORTANT ROLE IN THE MAINTENANCE OF ITS HOMEOSTASIS. DYSREGULATION OF MICROGLIA HAS BEEN ASSOCIATED WITH THE DEVELOPMENT AND MAINTENANCE OF CHRONIC PAIN. HOWEVER, THE RELEVANT MOLECULAR PATHWAYS REMAIN POORLY DEFINED. IN THIS STUDY, WE USED A MASS SPECTROMETRY-BASED PROTEOMIC APPROACH TO SCREEN POTENTIAL CHANGES OF HISTONE PROTEIN MODIFICATIONS IN MICROGLIA ISOLATED FROM THE BRAIN OF CONTROL AND CISPLATIN-INDUCED NEUROPATHIC PAIN ADULT C57BL/6J MALE MICE. WE IDENTIFIED SEVERAL NOVEL MICROGLIAL HISTONE MODIFICATIONS ASSOCIATED WITH PAIN, INCLUDING STATISTICALLY SIGNIFICANTLY DECREASED HISTONE H3.1 LYSINE 27 MONO-METHYLATION (H3.1K27ME1, 54.8% OF CONTROL) AND H3 LYSINE 56 TRI-METHYLATION (7.5% OF CONTROL), AS WELL AS A TREND SUGGESTING INCREASED H3 TYROSINE 41 NITRATION. WE FURTHER INVESTIGATED THE FUNCTIONAL ROLE OF H3.1K27ME1 AND FOUND THAT TREATMENT OF CULTURED MICROGLIAL CELLS FOR 4 CONSECUTIVE DAYS WITH 1-10 MUM OF NCDM-64, A POTENT AND SELECTIVE INHIBITOR OF LYSINE DEMETHYLASE 7A, AN ENZYME RESPONSIBLE FOR THE DEMETHYLATION OF H3K27ME1, DOSE-DEPENDENTLY ELEVATED ITS LEVELS WITH A GREATER THAN A TWO-FOLD INCREASE OBSERVED AT 10 MUM COMPARED TO VEHICLE-TREATED CONTROL CELLS. MOREOVER, PRETREATMENT OF MICE WITH NCDM-64 (10 OR 25 MG/KG/DAY, I.P.) PRIOR TO CISPLATIN TREATMENT PREVENTED THE DEVELOPMENT OF NEUROPATHIC PAIN IN MICE. THE IDENTIFICATION OF SPECIFIC CHROMATIN MARKS IN MICROGLIA ASSOCIATED WITH CHRONIC PAIN MAY YIELD CRITICAL INSIGHT INTO THE CONTRIBUTION OF MICROGLIA TO THE DEVELOPMENT AND MAINTENANCE OF PAIN, AND OPENS NEW AVENUES FOR THE DEVELOPMENT OF NOVEL NONOPIOID THERAPEUTICS FOR THE EFFECTIVE MANAGEMENT OF CHRONIC PAIN. 2022 14 4014 34 LOW-DOSE CD INDUCES HEPATIC GENE HYPERMETHYLATION, ALONG WITH THE PERSISTENT REDUCTION OF CELL DEATH AND INCREASE OF CELL PROLIFERATION IN RATS AND MICE. BACKGROUND: CADMIUM (CD) IS CLASSIFIED AS A HUMAN CARCINOGEN PROBABLY ASSOCIATED WITH EPIGENETIC CHANGES. DNA METHYLATION IS ONE OF EPIGENETIC MECHANISMS BY WHICH CELLS CONTROL GENE EXPRESSION. THEREFORE, THE PRESENT STUDY GENOME-WIDELY SCREENED THE METHYLATION-ALTERED GENES IN THE LIVER OF RATS PREVIOUSLY EXPOSED TO LOW-DOSE CD. METHODOLOGY PRINCIPAL FINDINGS: RATS WERE EXPOSED TO CD AT 20 NMOL/KG EVERY OTHER DAY FOR 4 WEEKS AND GENE METHYLATION WAS ANALYZED AT THE 48(TH) WEEK WITH METHYLATED DNA IMMUNOPRECIPITATION-CPG ISLAND MICROARRAY. AMONG THE 1629 ALTERED GENES, THERE WERE 675 GENES WHOSE PROMOTER CPG ISLANDS (CGIS) WERE HYPERMETHYLATED, 899 GENES WHOSE PROMOTER CGIS WERE HYPOMETHYLATED, AND 55 GENES WHOSE PROMOTER CGIS WERE MIXED WITH HYPER- AND HYPO-METHYLATION. CASPASE-8 GENE PROMOTER CGIS AND TNF GENE PROMOTER CGIS WERE HYPERMETHYLATED AND HYPOMETHYLATED, RESPECTIVELY, ALONG WITH A LOW APOPTOSIS RATE IN CD-TREATED RAT LIVERS. TO LINK THE ABERRANT METHYLATION OF CASPASE-8 AND TNF GENES TO THE LOW APOPTOSIS INDUCED BY LOW-DOSE CD, MICE WERE GIVEN CHRONIC EXPOSURE TO LOW-DOSE CD WITH AND WITHOUT METHYLATION INHIBITOR (5-AZA-2'-DEOXYCTIDENE, 5-AZA). AT THE 48(TH) WEEK AFTER CD EXPOSURE, LIVERS FROM CD-TREATED MICE DISPLAYED THE INCREASED CASPASE-8 CGI METHYLATION AND DECREASED CASPASE-8 PROTEIN EXPRESSION, ALONG WITH SIGNIFICANT INCREASES IN CELL PROLIFERATION AND OVEREXPRESSION OF TGF-BETA1 AND CYTOKERATIN 8/18 (THE LATTER IS A NEW MARKER OF MOUSE LIVER PRENEOPLASTIC LESIONS), ALL WHICH WERE PREVENTED BY 5-AZA TREATMENT. CONCLUSION/SIGNIFICANCE: THESE RESULTS SUGGEST THAT CD-INDUCED GLOBAL GENE HYPERMETHYLATION, MOST LIKELY CASPASE-8 GENE PROMOTER HYPERMETHYLATION THAT DOWN-REGULATED ITS EXPRESSION, LEADING TO THE DECREASED HEPATIC APOPTOSIS AND INCREASED PRENEOPLASTIC LESIONS. 2012 15 4159 34 MECP2 CONTROLS AN EPIGENETIC PATHWAY THAT PROMOTES MYOFIBROBLAST TRANSDIFFERENTIATION AND FIBROSIS. BACKGROUND & AIMS: MYOFIBROBLAST TRANSDIFFERENTIATION GENERATES HEPATIC MYOFIBROBLASTS, WHICH PROMOTE LIVER FIBROGENESIS. THE PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPARGAMMA) IS A NEGATIVE REGULATOR OF THIS PROCESS. WE INVESTIGATED EPIGENETIC REGULATION OF PPARGAMMA AND MYOFIBROBLAST TRANSDIFFERENTIATION. METHODS: CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAYS ASSESSED THE BINDING OF METHYL-CPG BINDING PROTEIN 2 (MECP2) TO PPARGAMMA AND CHROMATIN MODIFICATIONS THAT SILENCE THIS GENE. MECP2(-/Y) MICE AND AN INHIBITOR (DZNEP) OF THE EPIGENETIC REGULATORY PROTEIN EZH2 WERE USED IN THE CARBON TETRACHLORIDE MODEL OF LIVER FIBROSIS. LIVER TISSUES FROM MICE WERE ASSESSED BY HISTOLOGIC ANALYSIS; MARKERS OF FIBROSIS WERE MEASURED BY QUANTITATIVE POLYMERASE CHAIN REACTION (QPCR). REVERSE TRANSCRIPTION PCR DETECTED CHANGES IN EXPRESSION OF THE MICRORNA MIR132 AND ITS TARGET, ELONGATED TRANSCRIPTS OF MECP2. MYOFIBROBLASTS WERE TRANSFECTED WITH MIR132; PPARGAMMA AND MECP2 EXPRESSIONS WERE ANALYZED BY QPCR OR IMMUNOBLOTTING. RESULTS: MYOFIBROBLAST TRANSDIFFERENTIATION OF HEPATIC STELLATE CELLS IS CONTROLLED BY A COMBINATION OF MECP2, EZH2, AND MIR132 IN A RELAY PATHWAY. THE PATHWAY IS ACTIVATED BY DOWN-REGULATION OF MIR132, RELEASING THE TRANSLATIONAL BLOCK ON MECP2. MECP2 IS RECRUITED TO THE 5' END OF PPARGAMMA, WHERE IT PROMOTES METHYLATION BY H3K9 AND RECRUITS THE TRANSCRIPTION REPRESSOR HP1ALPHA. MECP2 ALSO STIMULATES EXPRESSION OF EZH2 AND METHYLATION OF H3K27 TO FORM A REPRESSIVE CHROMATIN STRUCTURE IN THE 3' EXONS OF PPARGAMMA. GENETIC AND PHARMACOLOGIC DISRUPTIONS OF MECP2 OR EZH2 REDUCED THE FIBROGENIC CHARACTERISTICS OF MYOFIBROBLASTS AND ATTENUATED FIBROGENESIS. CONCLUSIONS: LIVER FIBROSIS IS REGULATED BY AN EPIGENETIC RELAY PATHWAY THAT INCLUDES MECP2, EZH2, AND MIR132. REAGENTS THAT INTERFERE WITH THIS PATHWAY MIGHT BE DEVELOPED TO REDUCE FIBROGENESIS IN CHRONIC LIVER DISEASE. 2010 16 1117 32 COMPARATIVE AND EXPERIMENTAL STUDIES ON THE GENES ALTERED BY CHRONIC HYPOXIA IN HUMAN BRAIN MICROENDOTHELIAL CELLS. BACKGROUND : HYPOXIA INDUCIBLE FACTOR 1 ALPHA (HIF1A) IS A MASTER REGULATOR OF ACUTE HYPOXIA; HOWEVER, WITH CHRONIC HYPOXIA, HIF1A LEVELS RETURN TO THE NORMOXIC LEVELS. IMPORTANTLY, THE GENES THAT ARE INVOLVED IN THE CELL SURVIVAL AND VIABILITY UNDER CHRONIC HYPOXIA ARE NOT KNOWN. THEREFORE, WE TESTED THE HYPOTHESIS THAT CHRONIC HYPOXIA LEADS TO THE UPREGULATION OF A CORE GROUP OF GENES WITH ASSOCIATED CHANGES IN THE PROMOTER DNA METHYLATION THAT MEDIATES THE CELL SURVIVAL UNDER HYPOXIA. RESULTS : WE EXAMINED THE EFFECT OF CHRONIC HYPOXIA (3 DAYS; 0.5% OXYGEN) ON HUMAN BRAIN MICRO ENDOTHELIAL CELLS (HBMEC) VIABILITY AND APOPTOSIS. HYPOXIA CAUSED A SIGNIFICANT REDUCTION IN CELL VIABILITY AND AN INCREASE IN APOPTOSIS. NEXT, WE EXAMINED CHRONIC HYPOXIA ASSOCIATED CHANGES IN TRANSCRIPTOME AND GENOME-WIDE PROMOTER METHYLATION. THE DATA OBTAINED WAS COMPARED WITH 16 OTHER MICROARRAY STUDIES ON CHRONIC HYPOXIA. NINE GENES WERE ALTERED IN RESPONSE TO CHRONIC HYPOXIA IN ALL 17 STUDIES. INTERESTINGLY, HIF1A WAS NOT ALTERED WITH CHRONIC HYPOXIA IN ANY OF THE STUDIES. FURTHERMORE, WE COMPARED OUR DATA TO THREE OTHER STUDIES THAT IDENTIFIED HIF-RESPONSIVE GENES BY VARIOUS APPROACHES. ONLY TWO GENES WERE FOUND TO BE HIF DEPENDENT. WE SILENCED EACH OF THESE 9 GENES USING CRISPR/CAS9 SYSTEM. DOWNREGULATION OF EGLN3 SIGNIFICANTLY INCREASED THE CELL DEATH UNDER CHRONIC HYPOXIA, WHEREAS DOWNREGULATION OF ERO1L, ENO2, ADRENOMEDULLIN, AND SPAG4 REDUCED THE CELL DEATH UNDER HYPOXIA. CONCLUSIONS : WE PROVIDE A CORE GROUP OF GENES THAT REGULATES CELLULAR ACCLIMATIZATION UNDER CHRONIC HYPOXIC STRESS, AND MOST OF THEM ARE HIF INDEPENDENT. 2017 17 1965 36 EPIGENETIC ALTERATION OF MITOCHONDRIAL BIOGENESIS REGULATORY GENES IN ARSENIC EXPOSED INDIVIDUALS (WITH AND WITHOUT SKIN LESIONS) AND IN SKIN CANCER TISSUES: A CASE CONTROL STUDY. CHRONIC ARSENIC TOXICITY HAS BECOME A GLOBAL CONCERN DUE TO ITS ADVERSE PATHOPHYSIOLOGICAL OUTCOME AND CARCINOGENIC POTENTIAL. IT IS ALREADY ESTABLISHED THAT ARSENIC INDUCED REACTIVE OXYGEN SPECIES ALTERS MITOCHONDRIAL FUNCTIONALITY. MAJOR REGULATORY GENES FOR MITOCHONDRIAL BIOGENESIS, I.E., PGC1ALPHA, TFAM, NRF1AND NRF2 ARE LOCATED IN THE NUCLEUS. AS A RESULT, MITOCHONDRIA-NUCLEUS CROSSTALK IS CRUCIAL FOR PROPER MITOCHONDRIAL FUNCTION. THIS PREVIOUS HYPOTHESIS LED US TO INVESTIGATEINVOLVEMENT OF EPIGENETIC ALTERATION BEHINDENHANCED MITOCHONDRIAL BIOGENESIS IN CHRONIC ARSENIC EXPOSURE. AN EXTENSIVE CASE-CONTROL STUDY WAS CONDUCTED WITH 390 STUDY PARTICIPANTS (UNEXPOSED, EXPOSED WITHOUT SKIN LESION, EXPOSED WITH SKIN LESION AND EXPOSED SKIN TUMOUR) FROM HIGHLY ARSENIC EXPOSED AREAS OFWEST BENGAL, INDIA. METHYLATION SPECIFIC PCRREVEALED SIGNIFICANT PROMOTER HYPOMETHYLATION OFTWO KEY BIOGENESIS REGULATORY GENES, PGC1ALPHAANDTFAM IN ARSENIC EXPOSED INDIVIDUALS AND ALSO IN SKIN TUMOUR TISSUES. LINEAR REGRESSION ANALYSIS INDICATED SIGNIFICANT NEGATIVE CORRELATION BETWEEN URINARY ARSENIC CONCENTRATION AND PROMOTER METHYLATION STATUS. INCREASED EXPRESSION OF BIOGENESIS REGULATORY GENES WASOBTAINED BY QUANTITATIVE REAL-TIME PCR ANALYSIS. MOREOVER, ALTERED MITOCHONDRIAL FUSION-FISSION REGULATORY GENE EXPRESSION WAS ALSO OBSERVED IN SKIN TUMOUR TISSUES. MIR663, HAVING TUMOUR SUPPRESSOR GENE LIKE FUNCTION WAS KNOWN TO BE EPIGENETICALLY REGULATED THROUGH MITOCHONDRIAL RETROGRADE SIGNAL. PROMOTER HYPERMETHYLATION WITH SIGNIFICANTLY DECREASED EXPRESSION OF MIR663 WAS FOUND IN SKIN CANCER TISSUES COMPARED TO NON-CANCEROUS CONTROL TISSUE. IN CONCLUSION, RESULTS INDICATED CRUCIAL ROLE OF EPIGENETIC ALTERATION IN ARSENIC INDUCED MITOCHONDRIAL BIOGENESIS AND ARSENICAL SKIN CARCINOGENESIS FOR THE FIRST TIME. HOWEVER, FURTHER MECHANISTIC STUDIES ARE NECESSARY FOR DETAILED UNDERSTANDING OF MITOCHONDRIA-NUCLEUS CROSSTALK IN ARSENIC PERTURBATION. 2020 18 2774 36 EXTRACELLULAR SUPEROXIDE DISMUTASE (EC-SOD) REGULATES GENE METHYLATION AND CARDIAC FIBROSIS DURING CHRONIC HYPOXIC STRESS. CHRONIC HYPOXIC STRESS INDUCES EPIGENETIC MODIFICATIONS MAINLY DNA METHYLATION IN CARDIAC FIBROBLASTS, INACTIVATING TUMOR SUPPRESSOR GENES (RASSF1A) AND ACTIVATING KINASES (ERK1/2) LEADING TO FIBROBLAST PROLIFERATION AND CARDIAC FIBROSIS. THE RAS/ERK SIGNALING PATHWAY IS AN INTRACELLULAR SIGNAL TRANSDUCTION CRITICALLY INVOLVED IN FIBROBLAST PROLIFERATION. RASSF1A FUNCTIONS THROUGH ITS EFFECT ON DOWNSTREAM ERK1/2. THE ANTIOXIDANT ENZYME, EXTRACELLULAR SUPEROXIDE DISMUTASE (EC-SOD), DECREASES OXIDATIVE STRESS FROM CHRONIC HYPOXIA, BUT ITS EFFECTS ON THESE EPIGENETIC CHANGES HAVE NOT BEEN FULLY EXPLORED. TO TEST OUR HYPOTHESIS, WE USED AN IN-VITRO MODEL: WILD-TYPE C57B6 MALE MICE (WT) AND TRANSGENIC MALES WITH AN EXTRA COPY OF HUMAN HEC-SOD (TG). THE STUDIED ANIMALS WERE HOUSED IN HYPOXIA (10% O(2)) FOR 21 DAYS. THE RIGHT VENTRICULAR TISSUE WAS STUDIED FOR CARDIAC FIBROSIS MARKERS USING RT-PCR AND WESTERN BLOT ANALYSES. PRIMARY C57BL6 MOUSE CARDIAC FIBROBLAST TISSUE CULTURE WAS USED TO STUDY THE IN-VITRO MODEL, THE DOWNSTREAM EFFECTS OF RASSF-1 EXPRESSION AND METHYLATION, AND ITS RELATION TO ERK1/2. OUR FINDINGS SHOWED A SIGNIFICANT INCREASE IN CARDIAC FIBROSIS MARKERS: COLLAGEN 1, ALPHA SMOOTH MUSCLE ACTIN (ASMA), AND SNAIL, IN THE WT HYPOXIC ANIMALS AS COMPARED TO THE TG HYPOXIC GROUP (P < 0.05). THE EXPRESSION OF DNA METHYLATION ENZYMES (DNMT 1&3B) WAS SIGNIFICANTLY INCREASED IN THE WT HYPOXIC MICE AS COMPARED TO THE HYPOXIC TG MICE (P < 0.001). RASSF1A EXPRESSION WAS SIGNIFICANTLY LOWER AND ERK1/2 WAS SIGNIFICANTLY HIGHER IN HYPOXIA WT COMPARED TO THE HYPOXIC TG GROUP (P < 0.05). USE OF SIRNA TO BLOCK RASSF1A GENE EXPRESSION IN MURINE CARDIAC FIBROBLAST TISSUE CULTURE LED TO INCREASED FIBROBLAST PROLIFERATION (P < 0.05). METHYLATION OF THE RASSF1A PROMOTER REGION WAS SIGNIFICANTLY REDUCED IN THE TG HYPOXIC GROUP COMPARED TO THE WT HYPOXIC GROUP (0.59 VS. 0.75, RESPECTIVELY). BASED ON OUR FINDINGS, WE CAN SPECULATE THAT EC-SOD SIGNIFICANTLY ATTENUATES RASSF1A GENE METHYLATION AND CAN ALLEVIATE CARDIAC FIBROSIS INDUCED BY HYPOXIA. 2021 19 2673 41 ETHANOL-INDUCED MODULATION OF GPR55 EXPRESSION IN HUMAN MONOCYTE-DERIVED DENDRITIC CELLS IS ACCOMPANIED BY H4K12 ACETYLATION. INFLAMMATION SUPPORTS THE PROGRESSION OF ALCOHOL-RELATED ORGAN INJURY. RECENT RESEARCH FINDINGS HAVE LINKED ETHANOL EXPOSURE TO CHANGES IN HISTONE ACETYLATION AND DEACETYLATION IN THE BRAIN AND IN PERIPHERAL TISSUES, LEADING TO ETHANOL-DEPENDENCE RELATED DAMAGE. ONE OF THE MECHANISMS THAT HAS BEEN SHOWN TO PLAY A MAJOR ROLE DURING INFLAMMATION IS THE CANNABINOID SYSTEM. PREVIOUS RESEARCH HAS DEMONSTRATED THAT ETHANOL CAN MODULATE CANNABINOID RECEPTORS' FUNCTIONS. OUR LAB HAS SHOWN THAT THE G PROTEIN-COUPLED RECEPTOR (GPR55), A NOVEL CANNABINOID RECEPTOR, IS UPREGULATED IN BINGE DRINKERS AND IN CELLS TREATED ACUTELY WITH ETHANOL. ADDITIONALLY, OUR GROUP HAS ALSO UNCOVERED THAT CHRONIC ETHANOL EXPOSURE LEADS TO AN INCREASE IN HISTONE MODIFICATIONS, SUCH AS ACETYLATION. HOWEVER, THE REGULATORY MECHANISM OF GPR55 WITHIN THE IMMUNE SYSTEM UNDER THE INFLUENCE OF ETHANOL IS POORLY UNDERSTOOD. SINCE CHANGES IN HISTONE MODIFICATIONS MIGHT LEAD TO CHANGES IN GENE EXPRESSION, WE HYPOTHESIZE THAT THE MECHANISM OF ETHANOL-INDUCED UPREGULATION OF GPR55 IS LINKED TO EPIGENETIC CHANGES ON HISTONE PROTEINS. TAKING INTO ACCOUNT PREVIOUS FINDINGS FROM OUR LAB, THE GOAL OF THE PRESENT STUDY WAS TO DETERMINE WHETHER THERE IS ANY RELEVANT ASSOCIATION BETWEEN HISTONE HYPERACETYLATION AND THE REGULATION OF THE NOVEL CANNABINOID RECEPTOR GPR55 IN MONOCYTE-DERIVED DENDRITIC CELLS (MDDCS) OF HUMAN ORIGIN TREATED ACUTELY WITH ETHANOL. THEREFORE, MONOCYTES WERE ISOLATED FROM BUFFY COATS AND ALLOWED TO DIFFERENTIATE INTO MDDCS. THE CELLS WERE TREATED WITH ETHANOL FOR 24 H, HARVESTED, FIXED, AND STAINED WITH ANTIBODIES AGAINST GPR55. AS EXPECTED, BASED ON PREVIOUS FINDINGS, CONFOCAL MICROSCOPY SHOWED THAT ETHANOL EXPOSURE INCREASES GPR55 EXPRESSION. IN ORDER TO DEMONSTRATE THE CORRELATION BETWEEN HISTONE ACETYLATION AND GPR55 EXPRESSION REGULATION, THE CELLS WERE TREATED WITH ETHANOL, HARVESTED, AND THEN THE CHROMATIN WAS EXTRACTED AND FRACTIONATED FOR CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY, FOLLOWED BY REAL-TIME QPCR FOR THE ANALYSIS OF DNA FRAGMENTS. THE RESULTS SHOWED AN ENRICHMENT OF THE HISTONE MODIFICATION H4K12AC IN THE GPR55 GENE OF MDDCS TREATED WITH ETHANOL. FURTHERMORE, SIRNA AGAINST THE HISTONE ACETYLTRANSFERASE TIP60 (RESPONSIBLE FOR THE ACETYLATION OF H4K12) RESULTED IN A DOWNREGULATION OF GPR55. IN CONJUNCTION, THESE RESULTS INDICATE THAT IN THE PRESENCE OF ETHANOL, THE UPREGULATION OF GPR55 EXPRESSION IS ACCOMPANIED BY H4K12 ACETYLATION, WHICH MIGHT HAVE A SIGNIFICANT EFFECT IN THE ABILITY OF THIS INNATE IMMUNE SYSTEM'S CELLS TO COPE WITH CELLULAR STRESS INDUCED BY ETHANOL. HOWEVER, THE CAUSALITY OF ETHANOL REGULATION OF H4K12AC IN GPR55 EXPRESSION CHANGES STILL LACKS FURTHER ELUCIDATION; THEREFORE, ADDITIONAL EXPERIMENTAL APPROACHES TO CONFIRM A SIGNIFICANT CAUSALITY BETWEEN H4K12 ACETYLATION AND ETHANOL REGULATION OF GPR55 ARE CURRENTLY UNDERGOING IN OUR LAB. 2018 20 2068 32 EPIGENETIC CONTROL OF MICROSOMAL PROSTAGLANDIN E SYNTHASE-1 BY HDAC-MEDIATED RECRUITMENT OF P300. NONSTEROIDAL ANTI-INFLAMMATORY DRUGS ARE THE MOST WIDELY USED MEDICINE TO TREAT PAIN AND INFLAMMATION, AND TO INHIBIT PLATELET FUNCTION. UNDERSTANDING THE EXPRESSION REGULATION OF ENZYMES OF THE PROSTANOID PATHWAY IS OF GREAT MEDICAL RELEVANCE. HISTONE ACETYLATION CRUCIALLY CONTROLS GENE EXPRESSION. WE SET OUT TO IDENTIFY THE IMPACT OF HISTONE DEACETYLASES (HDACS) ON THE GENERATION OF PROSTANOIDS AND EXAMINE THE CONSEQUENCES ON VASCULAR FUNCTION. HDAC INHIBITION (HDACI) WITH THE PAN-HDAC INHIBITOR, VORINOSTAT, ATTENUATED PROSTAGLANDIN (PG)E(2) GENERATION IN THE MURINE VASCULATURE AND IN HUMAN VASCULAR SMOOTH MUSCLE CELLS. IN LINE WITH THIS, THE EXPRESSION OF THE KEY ENZYME FOR PGE(2) SYNTHESIS, MICROSOMAL PGE SYNTHASE-1 (PTGES1), WAS REDUCED BY HDACI. ACCORDINGLY, THE RELAXATION TO ARACHIDONIC ACID WAS DECREASED AFTER EX VIVO INCUBATION OF MURINE VESSELS WITH HDACI. TO IDENTIFY THE UNDERLYING MECHANISM, CHROMATIN IMMUNOPRECIPITATION (CHIP) AND CHIP-SEQUENCING ANALYSIS WERE PERFORMED. THESE RESULTS SUGGEST THAT HDACS ARE INVOLVED IN THE RECRUITMENT OF THE TRANSCRIPTIONAL ACTIVATOR P300 TO THE PTGES1 GENE AND THAT HDACI PREVENTED THIS EFFECT. IN LINE WITH THE ACETYLTRANSFERASE ACTIVITY OF P300, H3K27 ACETYLATION WAS REDUCED AFTER HDACI AND RESULTED IN THE FORMATION OF HETEROCHROMATIN IN THE PTGES1 GENE. IN CONCLUSION, HDAC ACTIVITY MAINTAINS PTGES1 EXPRESSION BY RECRUITING P300 TO ITS GENE. 2017