1 4493 120 MORAXELLA CATARRHALIS INDUCES INFLAMMATORY RESPONSE OF BRONCHIAL EPITHELIAL CELLS VIA MAPK AND NF-KAPPAB ACTIVATION AND HISTONE DEACETYLASE ACTIVITY REDUCTION. MORAXELLA CATARRHALIS IS A MAJOR CAUSE OF INFECTIOUS EXACERBATIONS OF CHRONIC OBSTRUCTIVE LUNG DISEASE (COPD) AND MAY ALSO CONTRIBUTE TO THE PATHOGENESIS OF COPD. LITTLE IS KNOWN ABOUT M. CATARRHALIS-BRONCHIAL EPITHELIUM INTERACTION. WE INVESTIGATED ACTIVATION OF M. CATARRHALIS INFECTED BRONCHIAL EPITHELIAL CELLS AND CHARACTERIZED THE SIGNAL TRANSDUCTION PATHWAYS. MOREOVER, WE TESTED THE HYPOTHESIS THAT THE M. CATARRHALIS-INDUCED CYTOKINE EXPRESSION IS REGULATED BY ACETYLATION OF HISTONE RESIDUES AND CONTROLLED BY HISTONE DEACETYLASE ACTIVITY (HDAC). WE DEMONSTRATED THAT M. CATARRHALIS INDUCED A STRONG TIME- AND DOSE-DEPENDENT INFLAMMATORY RESPONSE IN THE BRONCHIAL EPITHELIAL CELL LINE (BEAS-2B), CHARACTERIZED BY THE RELEASE OF IL-8 AND GM-CSF. FOR THIS CYTOKINE LIBERATION ACTIVATION OF THE ERK AND P38 MITOGEN-ACTIVATED PROTEIN (MAP) KINASES AND TRANSCRIPTION FACTOR NF-KAPPAB WAS REQUIRED. FURTHERMORE, M. CATARRHALIS-INFECTED BRONCHIAL EPITHELIAL CELLS SHOWED AN ENHANCED ACETYLATION OF HISTONE H3 AND H4 GLOBALLY AND AT THE PROMOTER OF THE IL8 GENE. PREVENTING HISTONE DEACETYLATION BY THE HISTONE DEACETYLASE INHIBITOR TRICHOSTATIN A AUGMENTED THE M. CATARRHALIS-INDUCED IL-8 RESPONSE. AFTER EXPOSURE TO M. CATARRHALIS, WE FOUND A DECREASE IN GLOBAL HISTONE DEACETYLASE EXPRESSION AND ACTIVITY. OUR FINDINGS SUGGEST THAT M. CATARRHALIS-INDUCED ACTIVATION OF IL8 GENE TRANSCRIPTION WAS CAUSED BY INTERFERENCE WITH EPIGENETIC MECHANISMS REGULATING IL8 GENE ACCESSIBILITY. OUR FINDINGS PROVIDE INSIGHT INTO IMPORTANT MOLECULAR AND CELLULAR MECHANISMS OF M. CATARRHALIS-INDUCED ACTIVATION OF HUMAN BRONCHIAL EPITHELIUM. 2006 2 2910 36 GENE EXPRESSION PROFILING OF EPIGENETIC CHROMATIN MODIFICATION ENZYMES AND HISTONE MARKS BY CIGARETTE SMOKE: IMPLICATIONS FOR COPD AND LUNG CANCER. CHROMATIN-MODIFYING ENZYMES MEDIATE DNA METHYLATION AND HISTONE MODIFICATIONS ON RECRUITMENT TO SPECIFIC TARGET GENE LOCI IN RESPONSE TO VARIOUS STIMULI. THE KEY ENZYMES THAT REGULATE CHROMATIN ACCESSIBILITY FOR MAINTENANCE OF MODIFICATIONS IN DNA AND HISTONES, AND FOR MODULATION OF GENE EXPRESSION PATTERNS IN RESPONSE TO CIGARETTE SMOKE (CS), ARE NOT KNOWN. WE HYPOTHESIZE THAT CS EXPOSURE ALTERS THE GENE EXPRESSION PATTERNS OF CHROMATIN-MODIFYING ENZYMES, WHICH THEN AFFECTS MULTIPLE DOWNSTREAM PATHWAYS INVOLVED IN THE RESPONSE TO CS. WE HAVE, THEREFORE, ANALYZED CHROMATIN-MODIFYING ENZYME PROFILES AND VALIDATED BY QUANTITATIVE REAL-TIME PCR (QPCR). WE ALSO PERFORMED IMMUNOBLOT ANALYSIS OF TARGETED HISTONE MARKS IN C57BL/6J MICE EXPOSED TO ACUTE AND SUBCHRONIC CS, AND OF LUNGS FROM NONSMOKERS, SMOKERS, AND PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). WE FOUND A SIGNIFICANT INCREASE IN EXPRESSION OF SEVERAL CHROMATIN MODIFICATION ENZYMES, INCLUDING DNA METHYLTRANSFERASES, HISTONE ACETYLTRANSFERASES, HISTONE METHYLTRANSFERASES, AND SET DOMAIN PROTEINS, HISTONE KINASES, AND UBIQUITINASES. OUR QPCR VALIDATION DATA REVEALED A SIGNIFICANT DOWNREGULATION OF DNMT1, DNMT3A, DNMT3B, HDAC2, HDAC4, HAT1, PRMT1, AND AURKB WE IDENTIFIED TARGETED CHROMATIN HISTONE MARKS (H3K56AC AND H4K12AC), WHICH ARE INDUCED BY CS. THUS CS-INDUCED GENOTOXIC STRESS DIFFERENTIALLY AFFECTS THE EXPRESSION OF EPIGENETIC MODULATORS THAT REGULATE TRANSCRIPTION OF TARGET GENES VIA DNA METHYLATION AND SITE-SPECIFIC HISTONE MODIFICATIONS. THIS MAY HAVE IMPLICATIONS IN DEVISING EPIGENETIC-BASED THERAPIES FOR COPD AND LUNG CANCER. 2016 3 1012 37 CIGARETTE SMOKE INDUCES DISTINCT HISTONE MODIFICATIONS IN LUNG CELLS: IMPLICATIONS FOR THE PATHOGENESIS OF COPD AND LUNG CANCER. CIGARETTE SMOKE (CS)-MEDIATED OXIDATIVE STRESS INDUCES SEVERAL SIGNALING CASCADES, INCLUDING KINASES, WHICH RESULTS IN CHROMATIN MODIFICATIONS (HISTONE ACETYLATION/DEACETYLATION AND HISTONE METHYLATION/DEMETHYLATION). WE HAVE PREVIOUSLY REPORTED THAT CS INDUCES CHROMATIN REMODELING IN PRO-INFLAMMATORY GENE PROMOTERS; HOWEVER, THE UNDERLYING SITE-SPECIFIC HISTONE MARKS FORMED IN HISTONES H3 AND H4 DURING CS EXPOSURE IN LUNGS IN VIVO AND IN LUNG CELLS IN VITRO, WHICH CAN EITHER DRIVE GENE EXPRESSION OR REPRESSION, ARE NOT KNOWN. WE HYPOTHESIZE THAT CS EXPOSURE IN MOUSE AND HUMAN BRONCHIAL EPITHELIAL CELLS (H292) CAN CAUSE SITE-SPECIFIC POSTTRANSLATIONAL HISTONE MODIFICATIONS (PTMS) THAT MAY PLAY AN IMPORTANT ROLE IN THE PATHOGENESIS OF CS-INDUCED CHRONIC LUNG DISEASES. WE USED A BOTTOM-UP MASS SPECTROMETRY APPROACH TO IDENTIFY SOME POTENTIALLY NOVEL HISTONE MARKS, INCLUDING ACETYLATION, MONOMETHYLATION, AND DIMETHYLATION, IN SPECIFIC LYSINE AND ARGININE RESIDUES OF HISTONES H3 AND H4 IN MOUSE LUNGS AND H292 CELLS. WE FOUND THAT CS-INDUCED DISTINCT POSTTRANSLATIONAL HISTONE MODIFICATION PATTERNS IN HISTONE H3 AND HISTONE H4 IN LUNG CELLS, WHICH MAY BE CONSIDERED AS USABLE BIOMARKERS FOR CS-INDUCED CHRONIC LUNG DISEASES. THESE IDENTIFIED HISTONE MARKS (HISTONE H3 AND HISTONE H4) MAY PLAY AN IMPORTANT ROLE IN THE EPIGENETIC STATE DURING THE PATHOGENESIS OF SMOKING-INDUCED CHRONIC LUNG DISEASES, SUCH AS CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND LUNG CANCER. 2014 4 5418 49 REGULATION OF DNA METHYLATION SIGNATURES ON NF-KAPPAB AND STAT3 PATHWAY GENES AND TET ACTIVITY IN CIGARETTE SMOKE EXTRACT-CHALLENGED CELLS/COPD EXACERBATION MODEL IN VITRO. BACKGROUND: CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A GLOBAL HEALTH PROBLEM. CURRENTLY, THERE IS A LACK OF KNOWLEDGE ABOUT THE PATHOBIOLOGY OF THIS DISEASE AND AVAILABLE THERAPIES ARE INEFFECTIVE. CIGARETTE SMOKING IS THE LEADING CAUSE OF COPD; HOWEVER, NOT ALL SMOKERS DEVELOP COPD. EXACERBATIONS OF COPD CAUSED BY MICROBES ARE COMMON AND DETRIMENTAL. APPROXIMATELY 20-50% OF PATIENT EXACERBATIONS ARE CAUSED BY BACTERIAL COLONIZATION IN THE LOWER AIRWAYS. IT IS GENERALLY ACCEPTED THAT EPIGENETIC MECHANISMS, ESPECIALLY DNA METHYLATION, PLAY AN IMPORTANT ROLE DURING PROGRESSION OF COPD. THUS, WE HYPOTHESIZED THAT DNA METHYLATION PATTERNS VARY SIGNIFICANTLY FOLLOWING SMOKE EXPOSURE AND DURING EXACERBATIONS CAUSED BY BACTERIAL INFECTIONS. TO TEST OUR HYPOTHESIS, WE USED AN IN VITRO STUDY MODEL THAT MIMICS COPD EXACERBATIONS AND PERFORMED EXTENSIVE STUDIES TO UNDERSTAND THE ROLE OF CPG PROMOTER METHYLATION OF NF-KAPPAB AND STAT3-MEDIATED PATHWAY GENES. BOTH NF-KAPPAB AND STAT3 TRANSCRIPTION FACTORS PLAY CRITICAL ROLES IN ORCHESTRATING INFLAMMATORY RESPONSES DURING CIGARETTE SMOKE EXPOSURE. IN BRIEF, HUMAN LUNG ADENOCARCINOMA CELLS WITH TYPE II ALVEOLAR EPITHELIUM CHARACTERISTICS (A549) WERE CHALLENGED WITH CIGARETTE SMOKE EXTRACT (CSE) OR DMSO (CONTROL) FOLLOWED BY A 3-H CHALLENGE WITH BACTERIAL LIPOPOLYSACCHARIDE (LPS; FROM PSEUDOMONAS AERUGINOSA) PRIOR TO THE TERMINATION OF CSE EXPOSURE (COPD EXACERBATION GROUP). THE PRODUCTION OF CYTOKINES/CHEMOKINES, REGULATION OF TRANSCRIPTION FACTORS, AND DNA METHYLATION OF SPECIFIC GENES WERE THEN ASSESSED. WE ALSO STUDIED CHANGES IN THE EXPRESSION AND ACTIVITY OF TEN-ELEVEN TRANSLOCASES (TETS), THE ENZYMES RESPONSIBLE FOR DNA DEMETHYLATION, AND ASSESSED THEIR ROLE IN REGULATING DNA METHYLATION IN THE CSE-CHALLENGED GROUP. RESULTS: THERE WAS A SIGNIFICANT INCREASE IN THE RELEASE OF CYTOKINES/CHEMOKINES (IL-8, MCP-1, IL-6 AND CCL5) IN THE COPD EXACERBATION GROUP AS COMPARED TO THE CONTROL GROUP. HYPOMETHYLATION OF NF-KAPPAB-MEDIATED PATHWAY GENES CORRELATED WITH THEIR INDUCTION IN OUR COPD EXACERBATION STUDY MODEL. FURTHER, WE OBSERVED AN IMPORTANT ROLE OF TET1/2 IN REGULATING THE DNA METHYLATION OF NF-KAPPAB, STAT3, IKK, AND NIK GENES AND CYTOKINE/CHEMOKINE PRODUCTION BY A549 CELLS DURING CSE CHALLENGE. CONCLUSIONS: STUDIES TO FURTHER DEFINE THE ROLE OF TETS IN CSE-MEDIATED EPIGENETIC REGULATION MAY LEAD TO THE DEVELOPMENT OF BETTER AND MORE EFFECTIVE THERAPEUTIC INTERVENTION STRATEGIES FOR COPD. 2020 5 4302 39 MICRORNA-223 CONTROLS THE EXPRESSION OF HISTONE DEACETYLASE 2: A NOVEL AXIS IN COPD. REDUCED ACTIVITY OF HISTONE DEACETYLASE 2 (HDAC2) HAS BEEN DESCRIBED IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), BUT THE MECHANISMS RESULTING IN DECREASED EXPRESSION OF THIS IMPORTANT EPIGENETIC MODIFIER REMAIN UNKNOWN. HERE, WE EMPLOYED SEVERAL IN VITRO EXPERIMENTS TO ADDRESS THE ROLE OF MICRORNAS (MIRNAS) ON THE REGULATION OF HDAC2 IN ENDOTHELIAL CELLS. MANIPULATION OF MIRNA LEVELS IN HUMAN PULMONARY ARTERY ENDOTHELIAL CELLS (HPAEC) WAS ACHIEVED BY USING ELECTROPORATION WITH ANTI-MIRNAS AND MIRNA MIMICS. TARGET PREDICTION SOFTWARE IDENTIFIED MIR-223 AS A POTENTIAL REPRESSOR OF HDAC2. IN SUBSEQUENT STIMULATION EXPERIMENTS USING INFLAMMATORY CYTOKINES KNOWN TO BE INCREASED IN PATIENTS WITH COPD, MIR-223 WAS FOUND TO BE SIGNIFICANTLY INDUCED. FUNCTIONAL ANALYSIS DEMONSTRATED THAT OVEREXPRESSION OF MIR-223 DECREASED HDAC2 EXPRESSION AND ACTIVITY IN HPAEC. CONVERSELY, HDAC2 EXPRESSION AND ACTIVITY WAS PRESERVED IN ANTI-MIR-223-TREATED CELLS. DIRECT MIRNA-TARGET INTERACTION WAS CONFIRMED BY REPORTER GENE ASSAY. IN A NEXT STEP, REDUCED EXPRESSION OF HDAC2 WAS FOUND TO INCREASE THE LEVELS OF THE CHEMOKINE FRACTALKINE (CX3CL1). IN VIVO STUDIES CONFIRMED ELEVATED EXPRESSION LEVELS OF MIR-223 IN MICE EXPOSED TO CIGARETTE SMOKE AND IN EMPHYSEMATOUS LUNG TISSUE FROM LPS-TREATED MICE. MOREOVER, A SIGNIFICANT INVERSE CORRELATION OF MIR-223 AND HDAC2 EXPRESSION WAS FOUND IN TWO INDEPENDENT COHORTS OF COPD PATIENTS. THESE DATA EMPHASIZE THAT MIR-223, THE MOST PREVALENT MIRNA IN COPD, CONTROLS EXPRESSION AND ACTIVITY OF HDAC2 IN PULMONARY CELLS, WHICH, IN TURN, MIGHT ALTER THE EXPRESSION PROFILE OF CHEMOKINES. THIS PATHWAY PROVIDES A NOVEL PATHOGENIC LINK BETWEEN DYSREGULATED MIRNA EXPRESSION AND EPIGENETIC ACTIVITY IN COPD. KEY MESSAGES: HISTONE DEACETYLASE 2 IS DIRECTLY TARGETED BY MIR-223. LEVELS OF MIR-223 ARE INDUCED BY INTERLEUKIN-1BETA AND TUMOR NECROSIS FACTOR-ALPHA. MIR-223 CONTROLS THE EXPRESSION OF FRACTALKINE BY TARGETING HISTONE DEACETYLASE 2. MIR-223 LEVELS ARE INCREASED IN COPD MOUSE MODELS. MIR-223 LEVELS INVERSELY CORRELATE WITH HDAC2 EXPRESSION IN COPD PATIENTS. 2016 6 2228 39 EPIGENETIC MODIFICATIONS OF HISTONES IN PERIODONTAL DISEASE. PERIODONTITIS IS A CHRONIC INFECTIOUS DISEASE DRIVEN BY DYSBIOSIS, AN IMBALANCE BETWEEN COMMENSAL BACTERIA AND THE HOST ORGANISM. PERIODONTITIS IS A LEADING CAUSE OF TOOTH LOSS IN ADULTS AND OCCURS IN ABOUT 50% OF THE US POPULATION. IN ADDITION TO THE CLINICAL CHALLENGES ASSOCIATED WITH TREATING PERIODONTITIS, THE PROGRESSION AND CHRONIC NATURE OF THIS DISEASE SERIOUSLY AFFECT HUMAN HEALTH. EMERGING EVIDENCE SUGGESTS THAT PERIODONTITIS IS ASSOCIATED WITH MECHANISMS BEYOND BACTERIA-INDUCED PROTEIN AND TISSUE DEGRADATION. HERE, WE HYPOTHESIZE THAT BACTERIA ARE ABLE TO INDUCE EPIGENETIC MODIFICATIONS IN ORAL EPITHELIAL CELLS MEDIATED BY HISTONE MODIFICATIONS. IN THIS STUDY, WE FOUND THAT DYSBIOSIS IN VIVO LED TO EPIGENETIC MODIFICATIONS, INCLUDING ACETYLATION OF HISTONES AND DOWNREGULATION OF DNA METHYLTRANSFERASE 1. IN ADDITION, IN VITRO EXPOSURE OF ORAL EPITHELIAL CELLS TO LIPOPOLYSACCHARIDES RESULTED IN HISTONE MODIFICATIONS, ACTIVATION OF TRANSCRIPTIONAL COACTIVATORS, SUCH AS P300/CBP, AND ACCUMULATION OF NUCLEAR FACTOR-KAPPAB (NF-KAPPAB). GIVEN THAT ORAL EPITHELIAL CELLS ARE THE FIRST LINE OF DEFENSE FOR THE PERIODONTIUM AGAINST BACTERIA, WE ALSO EVALUATED WHETHER ACTIVATION OF PATHOGEN RECOGNITION RECEPTORS INDUCED HISTONE MODIFICATIONS. WE FOUND THAT ACTIVATION OF THE TOLL-LIKE RECEPTORS 1, 2, AND 4 AND THE NUCLEOTIDE-BINDING OLIGOMERIZATION DOMAIN PROTEIN 1 INDUCED HISTONE ACETYLATION IN ORAL EPITHELIAL CELLS. OUR FINDINGS CORROBORATE THE EMERGING CONCEPT THAT EPIGENETIC MODIFICATIONS PLAY A ROLE IN THE DEVELOPMENT OF PERIODONTITIS. 2016 7 172 37 ABSENCE OF HDAC3 BY MATRIX STIFFNESS PROMOTES CHROMATIN REMODELING AND FIBROBLAST ACTIVATION IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC AND FATAL DISEASE CHARACTERIZED BY PROGRESSIVE AND IRREVERSIBLE LUNG SCARRING ASSOCIATED WITH PERSISTENT ACTIVATION OF FIBROBLASTS. EPIGENETICS COULD INTEGRATE DIVERSE MICROENVIRONMENTAL SIGNALS, SUCH AS STIFFNESS, TO DIRECT PERSISTENT FIBROBLAST ACTIVATION. HISTONE MODIFICATIONS BY DEACETYLASES (HDAC) MAY PLAY AN ESSENTIAL ROLE IN THE GENE EXPRESSION CHANGES INVOLVED IN THE PATHOLOGICAL REMODELING OF THE LUNG. PARTICULARLY, HDAC3 IS CRUCIAL FOR MAINTAINING CHROMATIN AND REGULATING GENE EXPRESSION, BUT LITTLE IS KNOWN ABOUT ITS ROLE IN IPF. IN THE STUDY, CONTROL AND IPF-DERIVED FIBROBLASTS WERE USED TO DETERMINE THE INFLUENCE OF HDAC3 ON CHROMATIN REMODELING AND GENE EXPRESSION ASSOCIATED WITH IPF SIGNATURE. ADDITIONALLY, THE CELLS WERE GROWN ON HYDROGELS TO MIMIC THE STIFFNESS OF A FIBROTIC LUNG. OUR RESULTS SHOWED A DECREASED HDAC3 IN THE NUCLEUS OF IPF FIBROBLASTS, WHICH CORRELATES WITH CHANGES IN NUCLEUS SIZE AND HETEROCHROMATIN LOSS. THE INHIBITION OF HDAC3 WITH A PHARMACOLOGICAL INHIBITOR CAUSES HYPERACETYLATION OF H3K9 AND PROVOKES AN INCREASED EXPRESSION OF COL1A1, ACTA2, AND P21. COMPARABLE RESULTS WERE FOUND IN HYDROGELS, WHERE MATRIX STIFFNESS PROMOTES THE LOSS OF NUCLEAR HDAC3 AND INCREASES THE PROFIBROTIC SIGNATURE. FINALLY, LATRUNCULIN B WAS USED TO CONFIRM THAT CHANGES BY STIFFNESS DEPEND ON THE MECHANOTRANSDUCTION SIGNALS. TOGETHER, THESE RESULTS SUGGEST THAT HDAC3 COULD BE A LINK BETWEEN EPIGENETIC MECHANISMS AND THE FIBROTIC MICROENVIRONMENT. 2023 8 3527 31 IL-6 ENHANCES THE NUCLEAR TRANSLOCATION OF DNA CYTOSINE-5-METHYLTRANSFERASE 1 (DNMT1) VIA PHOSPHORYLATION OF THE NUCLEAR LOCALIZATION SEQUENCE BY THE AKT KINASE. THE EPIGENETIC PROGRAMMING OF GENOMIC DNA IS ACCOMPLISHED, IN PART, BY SEVERAL DNA CYTOSINE-5-METHYLTRANSFERASES THAT ACT BY COVALENTLY MODIFYING CYTOSINES WITH THE ADDITION OF A METHYL GROUP. THIS COVALENT MODIFICATION IS MAINTAINED BY THE DNA CYTOSINE-5-METHYLTRANSFERASE-1 ENZYME (DNMT1), WHICH IS CAPABLE OF ACTING IN CONCERT WITH OTHER SIMILAR ENZYMES TO SILENCE IMPORTANT TUMOR SUPPRESSOR GENES. IL-6 IS A MULTIFUNCTIONAL MEDIATOR OF INFLAMMATION, ACTING THROUGH SEVERAL MAJOR SIGNALING CASCADES, INCLUDING THE PHOSPHATIDYLINOSITOL-3-KINASE PATHWAY (PI-3-K), WHICH ACTIVATES PROTEIN KINASE B (AKT/PKB) DOWNSTREAM. HERE, WE SHOW THAT THE SUBCELLULAR LOCALIZATION OF DNMT1 CAN BE ALTERED BY THE ADDITION OF IL-6, INCREASING THE RATE OF NUCLEAR TRANSLOCATION OF THE ENZYME FROM THE CYTOSOLIC COMPARTMENT. THE MECHANISM OF NUCLEAR TRANSLOCATION OF DNMT1 IS GREATLY ENHANCED BY PHOSPHORYLATION OF THE DNMT1 NUCLEAR LOCALIZATION SIGNAL (NLS) BY PKB/AKT KINASE. MUTAGENIC ALTERATION OF THE TWO AKT TARGET AMINO ACIDS WITHIN THE NLS RESULTS IN A MAJOR LOSS OF DNMT1 NUCLEAR TRANSLOCATION, WHILE THE CREATION OF A "PHOSPHO-MIMIC" AMINO ACID (MUTATION TO ACIDIC RESIDUES) RESTORES THIS COMPARTMENTATION ABILITY. THESE OBSERVATIONS SUGGEST AN INTERESTING HYPOTHESIS REGARDING HOW MEDIATORS OF CHRONIC INFLAMMATION MAY DISTURB THE DELICATE BALANCE OF CELLULAR COMPARTMENTALIZATION OF IMPORTANT PROTEINS, AND REVEALS A POTENTIAL MECHANISM FOR THE INDUCTION OR ENHANCEMENT OF TUMOR GROWTH VIA ALTERATION OF THE COMPONENTS INVOLVED IN THE EPIGENETIC PROGRAMMING OF A CELL. 2007 9 2493 41 EPIGENETICS AND CHROMATIN REMODELING PLAY A ROLE IN LUNG DISEASE. EPIGENETICS IS DEFINED AS HERITABLE CHANGES THAT AFFECT GENE EXPRESSION WITHOUT ALTERING THE DNA SEQUENCE. EPIGENETIC REGULATION OF GENE EXPRESSION IS FACILITATED THROUGH DIFFERENT MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS AND RNA-ASSOCIATED SILENCING BY SMALL NON-CODING RNAS. ALL THESE MECHANISMS ARE CRUCIAL FOR NORMAL DEVELOPMENT, DIFFERENTIATION AND TISSUE-SPECIFIC GENE EXPRESSION. THESE THREE SYSTEMS INTERACT AND STABILIZE ONE ANOTHER AND CAN INITIATE AND SUSTAIN EPIGENETIC SILENCING, THUS DETERMINING HERITABLE CHANGES IN GENE EXPRESSION. HISTONE ACETYLATION REGULATES DIVERSE CELLULAR FUNCTIONS INCLUDING INFLAMMATORY GENE EXPRESSION, DNA REPAIR AND CELL PROLIFERATION. TRANSCRIPTIONAL COACTIVATORS POSSESS INTRINSIC HISTONE ACETYLTRANSFERASE ACTIVITY AND THIS ACTIVITY DRIVES INFLAMMATORY GENE EXPRESSION. ELEVEN CLASSICAL HISTONE DEACETYLASES (HDACS) ACT TO REGULATE THE EXPRESSION OF DISTINCT SUBSETS OF INFLAMMATORY/IMMUNE GENES. THUS, LOSS OF HDAC ACTIVITY OR THE PRESENCE OF HDAC INHIBITORS CAN FURTHER ENHANCE INFLAMMATORY GENE EXPRESSION BY PRODUCING A GENE-SPECIFIC CHANGE IN HAT ACTIVITY. FOR EXAMPLE, HDAC2 EXPRESSION AND ACTIVITY ARE REDUCED IN LUNG MACROPHAGES, BIOPSY SPECIMENS, AND BLOOD CELLS FROM PATIENTS WITH SEVERE ASTHMA AND SMOKING ASTHMATICS, AS WELL AS IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). THIS MAY ACCOUNT, AT LEAST IN PART, FOR THE ENHANCED INFLAMMATION AND REDUCED STEROID RESPONSIVENESS SEEN IN THESE PATIENTS. OTHER PROTEINS, PARTICULARLY TRANSCRIPTION FACTORS, ARE ALSO ACETYLATED AND ARE TARGETS FOR DEACETYLATION BY HDACS AND SIRTUINS, A RELATED FAMILY OF 7 PREDOMINANTLY PROTEIN DEACETYLASES. THUS THE ACETYLATION/DEACETYLATION STATUS OF NF-KAPPAB AND THE GLUCOCORTICOID RECEPTOR CAN ALSO AFFECT THE OVERALL EXPRESSION PATTERN OF INFLAMMATORY GENES AND REGULATE THE INFLAMMATORY RESPONSE. UNDERSTANDING AND TARGETING SPECIFIC ENZYMES INVOLVED IN THIS PROCESS MIGHT LEAD TO NEW THERAPEUTIC AGENTS, PARTICULARLY IN SITUATIONS IN WHICH CURRENT ANTI-INFLAMMATORY THERAPIES ARE SUBOPTIMAL. 2011 10 3795 41 INTERLEUKIN-6 CONTRIBUTES TO GROWTH IN CHOLANGIOCARCINOMA CELLS BY ABERRANT PROMOTER METHYLATION AND GENE EXPRESSION. THE ASSOCIATION BETWEEN CHRONIC INFLAMMATION AND THE DEVELOPMENT AND PROGRESSION OF MALIGNANCY IS EXEMPLIFIED IN THE BILIARY TRACT WHERE PERSISTENT INFLAMMATION STRONGLY PREDISPOSES TO CHOLANGIOCARCINOMA. THE INFLAMMATORY CYTOKINE INTERLEUKIN-6 (IL-6) ENHANCES TUMOR GROWTH IN CHOLANGIOCARCINOMA BY ALTERED GENE EXPRESSION VIA AUTOCRINE MECHANISMS. IL-6 CAN REGULATE THE ACTIVITY OF DNA METHYLTRANSFERASES, AND MOREOVER, ABERRANT DNA METHYLATION CAN CONTRIBUTE TO CARCINOGENESIS. WE THEREFORE INVESTIGATED THE EFFECT OF CHRONIC EXPOSURE TO IL-6 ON METHYLATION-DEPENDENT GENE EXPRESSION AND TRANSFORMED CELL GROWTH IN HUMAN CHOLANGIOCARCINOMA. THE RELATIONSHIP BETWEEN AUTOCRINE IL-6 PATHWAYS, DNA METHYLATION, AND TRANSFORMED CELL GROWTH WAS ASSESSED USING MALIGNANT CHOLANGIOCYTES STABLY TRANSFECTED TO OVEREXPRESS IL-6. TREATMENT WITH THE DNA METHYLATION INHIBITOR 5-AZA-2'-DEOXYCYTIDINE DECREASED CELL PROLIFERATION, GROWTH IN SOFT AGAR, AND METHYLCYTOSINE CONTENT OF MALIGNANT CHOLANGIOCYTES. HOWEVER, THIS EFFECT WAS NOT OBSERVED IN IL-6-OVEREXPRESSING CELLS. IL-6 OVEREXPRESSION RESULTED IN THE ALTERED EXPRESSION AND PROMOTER METHYLATION OF SEVERAL GENES, INCLUDING THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR). EGFR PROMOTER METHYLATION WAS DECREASED AND GENE AND PROTEIN EXPRESSION WAS INCREASED BY IL-6. THUS, EPIGENETIC REGULATION OF GENE EXPRESSION BY IL-6 CAN CONTRIBUTE TO TUMOR PROGRESSION BY ALTERING PROMOTER METHYLATION AND GENE EXPRESSION OF GROWTH-REGULATORY PATHWAYS, SUCH AS THOSE INVOLVING EGFR. MOREOVER, ENHANCED IL-6 EXPRESSION MAY DECREASE THE SENSITIVITY OF TUMOR CELLS TO THERAPEUTIC TREATMENTS USING METHYLATION INHIBITORS. THESE OBSERVATIONS HAVE IMPORTANT IMPLICATIONS FOR CANCER TREATMENT AND PROVIDE A MECHANISM BY WHICH PERSISTENT CYTOKINE STIMULATION CAN PROMOTE TUMOR GROWTH. 2006 11 3193 46 HDAC INHIBITION REGULATES OXIDATIVE STRESS IN CD4(+)THELPER CELLS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE AND NON-SMALL CELL LUNG CANCER PATIENTS VIA MITOCHONDRIAL TRANSCRIPTION FACTOR A (MTTFA) MODULATING NF-KAPPAB/HIF1ALPHA AXIS. HISTONE DEACETYLASES (HDACS) PLAY A CRUCIAL ROLE IN THE EPIGENETIC REGULATION OF GENE EXPRESSION BY REMODELLING CHROMATIN. ISOENZYMES OF THE HDAC FAMILY EXHIBIT ABERRANT REGULATION IN A WIDE VARIETY OF CANCERS AS WELL AS SEVERAL INFLAMMATORY LUNG DISORDERS LIKE CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). INHIBITION OF HDACS IS A POTENTIAL THERAPEUTIC STRATEGY THAT COULD BE USED TO REVERSE EPIGENETIC MODIFICATION. TRICHOSTATIN A (TSA), A POWERFUL HISTONE DEACETYLASE (HDAC) INHIBITOR, HAS ANTI-CANCER EFFECTS IN NUMEROUS CANCER TYPES. HOWEVER, IT IS NOT YET APPARENT HOW HDAC INHIBITORS AFFECT HUMAN NON-SMALL CELL LUNG CANCER CELLS (NSCLC) AND COPD. THIS STUDY AIMS TO INVESTIGATE TSA'S ROLE IN RESTORING MITOCHONDRIAL DYSFUNCTION AND ITS EFFECT ON HYPOXIA AND INFLAMMATION IN CD4(+)T CELLS OBTAINED FROM PATIENTS WITH COPD AND LUNG CANCER. AS A RESULT OF TREATMENT WITH TSA, THERE IS A REDUCTION IN THE EXPRESSION OF INFLAMMATORY CYTOKINES AND A DECREASED ENRICHMENT OF TRANSCRIPTIONAL FACTORS ASSOCIATED WITH INFLAMMATION AT VEGFA GENE LOCI. WE HAVE SEEN A SUBSTANTIAL DECREASE IN THE EXPRESSION OF NF-KAPPAB AND HIF1ALPHA, WHICH ARE THE CRITICAL MEDIATORS OF INFLAMMATION AND HYPOXIA, RESPECTIVELY. FOLLOWING TSA TREATMENT, MTTFA EXPRESSION WAS INCREASED, FACILITATING PATIENTS WITH COPD AND NSCLC IN THE RECOVERY OF THEIR DYSFUNCTIONAL MITOCHONDRIA. FURTHERMORE, WE HAVE DISCOVERED THAT TSA TREATMENT IN PATIENTS WITH COPD AND NSCLC MAY LEAD TO IMMUNOPROTECTIVE NESS BY INDUCING TH1NESS. OUR FINDING GIVES A NEW INSIGHT INTO THE EXISTING BODY OF KNOWLEDGE REGARDING TSA-BASED THERAPEUTIC METHODS AND HIGHLIGHTS THE NECESSITY OF EPIGENETIC THERAPY FOR THESE DEVASTATING LUNG DISORDERS. 2023 12 5946 32 TARGETING THE EPIGENOME IN THE TREATMENT OF ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. EPIGENETIC MODIFICATION OF GENE EXPRESSION BY METHYLATION OF DNA AND VARIOUS POST-TRANSLATIONAL MODIFICATIONS OF HISTONES MAY AFFECT THE EXPRESSION OF MULTIPLE INFLAMMATORY GENES. ACETYLATION OF HISTONES BY HISTONE ACETYLTRANSFERASES ACTIVATES INFLAMMATORY GENES, WHEREAS HISTONE DEACETYLATION RESULTS IN INFLAMMATORY GENE REPRESSION. CORTICOSTEROIDS EXERT THEIR ANTIINFLAMMATORY EFFECTS PARTLY BY INDUCING ACETYLATION OF ANTIINFLAMMATORY GENES, BUT MAINLY BY RECRUITING HISTONE DEACETYLASE-2 (HDAC2) TO ACTIVATED INFLAMMATORY GENES. HDAC2 DEACETYLATES ACETYLATED GLUCOCORTICOID RECEPTORS SO THAT THEY CAN SUPPRESS ACTIVATED INFLAMMATORY GENES IN ASTHMA. IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD), THERE IS RESISTANCE TO THE ANTIINFLAMMATORY ACTIONS OF CORTICOSTEROIDS, WHICH IS EXPLAINED BY REDUCED ACTIVITY AND EXPRESSION OF HDAC2. THIS CAN BE REVERSED BY A PLASMID VECTOR, WHICH RESTORES HDAC2 LEVELS, BUT MAY ALSO BE ACHIEVED BY LOW CONCENTRATIONS OF THEOPHYLLINE. OXIDATIVE STRESS CAUSES CORTICOSTEROID RESISTANCE BY REDUCING HDAC2 ACTIVITY AND EXPRESSION BY ACTIVATION OF PHOSPHOINOSITIDE-3-KINASE-DELTA, RESULTING IN HDAC2 PHOSPHORYLATION VIA A CASCADE OF KINASES. THEOPHYLLINE REVERSES CORTICOSTEROID RESISTANCE BY DIRECTLY INHIBITING OXIDANT-ACTIVATED PI3KDELTA AND IS MIMICKED BY PI3KDELTA KNOCKOUT OR BY SELECTIVE INHIBITORS. OTHER TREATMENTS MAY ALSO INTERACT IN THIS PATHWAY, MAKING IT POSSIBLE TO REVERSE CORTICOSTEROID RESISTANCE IN PATIENTS WITH COPD, AS WELL AS IN SMOKERS WITH ASTHMA AND SOME PATIENTS WITH SEVERE ASTHMA IN WHOM SIMILAR MECHANISMS OPERATE. OTHER HISTONE MODIFICATIONS, INCLUDING METHYLATION, TYROSINE NITRATION, AND UBIQUITINATION MAY ALSO AFFECT HISTONE FUNCTION AND INFLAMMATORY GENE EXPRESSION, AND BETTER UNDERSTANDING OF THESE EPIGENETIC PATHWAYS COULD LED TO NOVEL ANTIINFLAMMATORY THERAPIES, PARTICULARLY IN CORTICOSTEROID-RESISTANT INFLAMMATION. 2009 13 5972 30 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 14 141 32 ABERRANT DNA METHYLATION OF MTOR PATHWAY GENES PROMOTES INFLAMMATORY ACTIVATION OF IMMUNE CELLS IN DIABETIC KIDNEY DISEASE. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF DIABETIC KIDNEY DISEASE (DKD), BUT THE UNDERLYING MECHANISMS REMAIN UNCLEAR. IN THIS STUDY, WE TESTED THE HYPOTHESIS THAT ABERRANT DNA METHYLATION IN PERIPHERAL IMMUNE CELLS CONTRIBUTES TO DKD PROGRESSION. WE SHOWED THAT LEVELS OF DNA METHYLTRANSFERASE 1 (DNMT1), A KEY ENZYME FOR DNA METHYLATION, WERE INCREASED ALONG WITH INFLAMMATORY ACTIVITY OF PERIPHERAL BLOOD MONONUCLEAR CELLS IN DKD PATIENTS. INHIBITION OF DNMT1 WITH 5-AZA-2'-DEOXYCYTIDINE (5-AZA) MARKEDLY INCREASED THE PROPORTION OF CD4(+)CD25(+) REGULATORY T CELLS IN PERIPHERAL BLOOD MONONUCLEAR CELLS IN CULTURE AND IN DIABETIC ANIMALS. ADOPTIVE TRANSFER OF IMMUNE CELLS FROM 5-AZA-TREATED ANIMALS SHOWED BENEFICIAL EFFECTS ON THE HOST IMMUNE SYSTEM, RESULTING IN A SIGNIFICANT IMPROVEMENT OF DKD. USING GENOME-WIDE DNA METHYLATION ASSAYS, WE IDENTIFIED THE DIFFERENTIALLY METHYLATED CYTOSINES IN THE PROMOTER REGIONS OF MAMMALIAN TARGET OF RAPAMYCIN (MTOR) REGULATORS IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF DIABETIC PATIENTS. FURTHER, MRNA ARRAYS CONFIRMED THE CONSISTENT INDUCTION OF GENES EXPRESSED IN THE MTOR PATHWAY. IMPORTANTLY, DOWN-REGULATION OF DNMT1 EXPRESSION VIA RNA INTERFERENCE RESULTED IN PROMINENT CYTOSINE DEMETHYLATION OF MTOR NEGATIVE REGULATORS AND SUBSEQUENT DECREASE OF MTOR ACTIVITY. LASTLY, MODULATION OF MTOR RESULTED IN CHANGES IN THE EFFECT OF 5-AZA ON DIABETIC IMMUNE CELLS. THUS, UP-REGULATION OF DNMT1 IN DIABETIC IMMUNE CELLS INDUCES ABERRANT CYTOSINE METHYLATION OF THE UPSTREAM REGULATORS OF MTOR, LEADING TO PATHOGENIC ACTIVATION OF THE MTOR PATHWAY AND CONSEQUENT INFLAMMATION IN DIABETIC KIDNEYS. HENCE, THIS STUDY HIGHLIGHTS THERAPEUTIC POTENTIAL OF TARGETING EPIGENETIC EVENTS IN IMMUNE SYSTEM FOR TREATING DKD. 2019 15 2926 31 GENERATION OF AN EPIGENETIC SIGNATURE BY CHRONIC HYPOXIA IN PROSTATE CELLS. INCREASING LEVELS OF TISSUE HYPOXIA HAVE BEEN REPORTED AS A NATURAL FEATURE OF THE AGING PROSTATE GLAND AND MAY BE A RISK FACTOR FOR THE DEVELOPMENT OF PROSTATE CANCER. IN THIS STUDY, WE HAVE USED PWR-1E BENIGN PROSTATE EPITHELIAL CELLS AND AN EQUIVALENTLY AGED HYPOXIA-ADAPTED PWR-1E SUB-LINE TO IDENTIFY PHENOTYPIC AND EPIGENETIC CONSEQUENCES OF CHRONIC HYPOXIA IN PROSTATE CELLS. WE HAVE IDENTIFIED A SIGNIFICANTLY ALTERED CELLULAR PHENOTYPE IN RESPONSE TO CHRONIC HYPOXIA AS CHARACTERIZED BY INCREASED RECEPTOR-MEDIATED APOPTOTIC RESISTANCE, THE INDUCTION OF CELLULAR SENESCENCE, INCREASED INVASION AND THE INCREASED SECRETION OF IL-1 BETA, IL6, IL8 AND TNFALPHA CYTOKINES. IN ASSOCIATION WITH THESE PHENOTYPIC CHANGES AND THE ABSENCE OF HIF-1 ALPHA PROTEIN EXPRESSION, WE HAVE DEMONSTRATED SIGNIFICANT INCREASES IN GLOBAL LEVELS OF DNA METHYLATION AND H3K9 HISTONE ACETYLATION IN THESE CELLS, CONCOMITANT WITH THE INCREASED EXPRESSION OF DNA METHYLTRANSFERASE DMNT3B AND GENE-SPECIFIC CHANGES IN DNA METHYLATION AT KEY IMPRINTING LOCI. IN CONCLUSION, WE HAVE DEMONSTRATED A GENOME-WIDE ADJUSTMENT OF DNA METHYLATION AND HISTONE ACETYLATION UNDER CHRONIC HYPOXIC CONDITIONS IN THE PROSTATE. THESE EPIGENETIC SIGNATURES MAY REPRESENT AN ADDITIONAL MECHANISM TO PROMOTE AND MAINTAIN A HYPOXIC-ADAPTED CELLULAR PHENOTYPE WITH A POTENTIAL ROLE IN TUMOUR DEVELOPMENT. 2009 16 4563 32 MYELOID DNA METHYLTRANSFERASE3B DEFICIENCY AGGRAVATES PULMONARY FIBROSIS BY ENHANCING PROFIBROTIC MACROPHAGE ACTIVATION. BACKGROUND: IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC, PROGRESSIVE AND SEVERE DISEASE CHARACTERIZED BY EXCESSIVE MATRIX DEPOSITION IN THE LUNGS. MACROPHAGES PLAY CRUCIAL ROLES IN MAINTAINING LUNG HOMEOSTASIS BUT ARE ALSO CENTRAL IN THE PATHOGENESIS OF LUNG DISEASES LIKE PULMONARY FIBROSIS. ESPECIALLY, MACROPHAGE POLARIZATION/ACTIVATION SEEMS TO PLAY A CRUCIAL ROLE IN PATHOLOGY AND EPIGENETIC REPROGRAMING IS WELL-KNOWN TO REGULATE MACROPHAGE POLARIZATION. DNA METHYLATION ALTERATIONS IN IPF LUNGS HAVE BEEN WELL DOCUMENTED, BUT THE ROLE OF DNA METHYLATION IN SPECIFIC CELL TYPES, ESPECIALLY MACROPHAGES, IS POORLY DEFINED. METHODS: IN ORDER TO DETERMINE THE ROLE OF DNA METHYLATION IN MACROPHAGES DURING PULMONARY FIBROSIS, WE SUBJECTED MACROPHAGE SPECIFIC DNA METHYLTRANSFERASE (DNMT)3B, WHICH MEDIATES THE DE NOVO DNA METHYLATION, DEFICIENT MICE TO THE BLEOMYCIN-INDUCED PULMONARY FIBROSIS MODEL. MACROPHAGE POLARIZATION AND FIBROTIC PARAMETERS WERE EVALUATED AT 21 DAYS AFTER BLEOMYCIN ADMINISTRATION. DNMT3B KNOCKOUT AND WILD TYPE BONE MARROW-DERIVED MACROPHAGES WERE STIMULATED WITH EITHER INTERLEUKIN (IL)4 OR TRANSFORMING GROWTH FACTOR BETA 1 (TGFB1) IN VITRO, AFTER WHICH PROFIBROTIC GENE EXPRESSION AND DNA METHYLATION AT THE ARG1 PROMOTOR WERE DETERMINED. RESULTS: WE SHOW THAT DNMT3B DEFICIENCY PROMOTES ALTERNATIVE MACROPHAGE POLARIZATION INDUCED BY IL4 AND TGFB1 IN VITRO AND ALSO ENHANCES PROFIBROTIC MACROPHAGE POLARIZATION IN THE ALVEOLAR SPACE DURING PULMONARY FIBROSIS IN VIVO. MOREOVER, MYELOID SPECIFIC DELETION OF DNMT3B PROMOTED THE DEVELOPMENT OF EXPERIMENTAL PULMONARY FIBROSIS. CONCLUSIONS: IN SUMMARY, THESE DATA SUGGEST THAT MYELOID DNMT3B REPRESSES FIBROTIC MACROPHAGE POLARIZATION AND PROTECTS AGAINST BLEOMYCIN INDUCED PULMONARY FIBROSIS. 2022 17 808 28 CHANGED HISTONE ACETYLATION PATTERNS IN NORMAL-APPEARING WHITE MATTER AND EARLY MULTIPLE SCLEROSIS LESIONS. THE EPIGENETIC IDENTITY OF OLIGODENDROCYTES IS MODULATED BY POSTTRANSLATIONAL MODIFICATIONS OF HISTONES. ACETYLATION OF HISTONE H3 RESULTS FROM THE BALANCE BETWEEN THE ACTIVITY OF HISTONE ACETYLTRANSFERASES (HATS) AND HISTONE DEACETYLASES AND MODULATES TRANSCRIPTIONAL ACTIVATION. WE HAVE PREVIOUSLY SHOWN THAT, IN RODENTS, HISTONE DEACETYLATION FAVORS OLIGODENDROCYTE DIFFERENTIATION, WHEREAS ACETYLATION IS ASSOCIATED WITH INCREASED LEVELS OF TRANSCRIPTIONAL INHIBITORS OF OLIGODENDROCYTE DIFFERENTIATION. HERE, WE REPORT, IN HUMANS BRAINS, A SHIFT TOWARD HISTONE ACETYLATION IN THE WHITE MATTER OF THE FRONTAL LOBES OF AGED SUBJECTS AND IN PATIENTS WITH CHRONIC MULTIPLE SCLEROSIS (MS). INCREASED IMMUNOREACTIVITY FOR ACETYLATED HISTONE H3 WAS OBSERVED IN THE NUCLEI OF NOGOA+ OLIGODENDROCYTES IN A SUBSET OF MS SAMPLES. THESE CHANGES WERE ASSOCIATED WITH HIGH LEVELS OF TRANSCRIPTIONAL INHIBITORS OF OLIGODENDROCYTE DIFFERENTIATION (I.E., TCF7L2, ID2, AND SOX2) AND HIGHER HAT TRANSCRIPT LEVELS (I.E., CBP, P300) IN FEMALE MS PATIENTS COMPARED WITH NON-NEUROLOGICAL CONTROLS AND CORRELATED WITH DISEASE DURATION. CHROMATIN IMMUNOPRECIPITATION FROM SAMPLES OF MS PATIENTS REVEALED ENRICHMENT OF ACETYL-HISTONE H3 AT THE PROMOTER OF THE INCREASED TARGET GENES (I.E., TCF7L2). THE DATA IN CHRONIC LESIONS CONTRASTED WITH FINDINGS IN EARLY MS LESIONS, WHERE A MARKED OLIGODENDROGLIAL HISTONE DEACETYLATION WAS OBSERVED. TOGETHER, THESE DATA SUGGEST THAT HISTONE DEACETYLATION IS A PROCESS THAT OCCURS AT THE EARLY STAGES OF THE DISEASE AND WHOSE EFFICIENCY DECREASES WITH DISEASE DURATION. 2011 18 1251 31 CURRENT PERSPECTIVES ON ROLE OF CHROMATIN MODIFICATIONS AND DEACETYLASES IN LUNG INFLAMMATION IN COPD. CHROMATIN MODIFICATIONS AND EPIGENETIC REGULATION ARE CRITICAL FOR SUSTAINED AND ABNORMAL INFLAMMATORY RESPONSE SEEN IN LUNGS OF PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) BECAUSE THE ACTIVITIES OF ENZYMES THAT REGULATE THESE EPIGENETIC MODIFICATIONS ARE ALTERED IN RESPONSE TO CIGARETTE SMOKE. CIGARETTE SMOKE INDUCES CHROMATIN MODIFICATIONS AND EPIGENETIC CHANGES BY CAUSING POST-TRANSLATIONAL MODIFICATIONS OF HISTONE ACETYLTRANSFERASES, AND HISTONE/NON-HISTONE DEACETYLASES (HDACS), SUCH AS HDAC2 AND SIRTUIN 1 (SIRT1), WHICH LEADS TO CHROMATIN REMODELING. IN THIS REVIEW, WE DISCUSSED THE CURRENT KNOWLEDGE ON CIGARETTE SMOKE/OXIDANTS-INDUCED POST-TRANSLATIONAL MODIFICATIONS OF DEACETYLASES (HDAC2 AND SIRT1), DISRUPTION OF HDAC2/SIRT1-RELA/P65 COREPRESSOR COMPLEX ASSOCIATED WITH ACETYLATION OF RELA/P65, AND CHROMATIN MODIFICATIONS (HISTONE H3 PHOSPHO-ACETYLATION) LEADING TO SUSTAINED PRO-INFLAMMATORY GENE TRANSCRIPTION. KNOWLEDGE ON MOLECULAR MECHANISMS OF EPIGENETIC CHANGES IN ABNORMAL LUNG INFLAMMATION WILL HELP IN UNDERSTANDING THE PATHOPHYSIOLOGY OF COPD WHICH MAY LEAD TO THE DEVELOPMENT OF NOVEL EPIGENETIC THERAPIES IN THE NEAR FUTURE. 2009 19 4899 28 OXIDATIVE STRESS MEDIATES THE APOPTOSIS AND EPIGENETIC MODIFICATION OF THE BCL-2 PROMOTER VIA DNMT1 IN A CIGARETTE SMOKE-INDUCED EMPHYSEMA MODEL. BACKGROUND: EMPHYSEMA IS A CRUCIAL PATHOLOGICAL CHARACTERISTIC OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). OXIDATIVE STRESS, APOPTOSIS AND EPIGENETIC MECHANISMS CONTRIBUTE TO THE PATHOGENESIS OF EMPHYSEMA. HOWEVER, AN ATTEMPT TO ACCURATELY IDENTIFY WHETHER THESE MECHANISMS INTERACT WITH EACH OTHER AND HOW THEY ARE TRIGGERED HAS NEVER BEEN CONDUCTED. METHOD: THE TOTAL REACTIVE OXYGEN SPECIES (ROS) LEVEL, PULMONARY APOPTOSIS AND B-CELL LYMPHOMA/LEUKEMIA-2 (BCL-2) EXPRESSION, AN APOPTOSIS REGULATOR, WERE DETECTED IN SAMPLES FROM COPD PATIENTS. BISULFITE SEQUENCING PCR (BSP) WAS CONDUCTED TO OBSERVE THE ALTERATIONS IN THE METHYLATION OF THE BCL-2 PROMOTER IN SPECIMENS. THE DYSREGULATION OF DNA METHYLTRANSFERASE ENZYME 1 (DNMT1), A VITAL DNA METHYLTRANSFERASE ENZYME, IN THE LUNGS OF PATIENTS WAS CONFIRMED THROUGH WESTERN BLOTTING. TO FIND OUT INTERACTIONS BETWEEN OXIDATIVE STRESS AND DNA METHYLATION IN EMPHYSEMA, MOUSE MODELS WERE BUILT WITH ANTIOXIDANT TREATMENT AND DNMT1 SILENCING, AND WERE EXAMINED WITH THE PULMONARY APOPTOSIS, BCL-2 AND DNMT1 LEVELS, AND EPIGENETIC ALTERATIONS OF BCL-2. RESULTS: HIGHER ROS LEVELS AND PULMONARY APOPTOSIS WERE OBSERVED IN COPD PATIENTS THAN IN HEALTHY CONTROLS. DOWNREGULATED BCL-2 EXPRESSION WITH INCREASED PROMOTER METHYLATION AND DNMT1 PROTEIN EXPRESSION WAS FOUND IN COPD PATIENTS. ANTIOXIDANT TREATMENT REDUCED THE LEVEL OF ROS, DNMT1 PROTEIN AND EMPHYSEMATOUS PROGRESSION IN THE SMOKING MODELS. FOLLOWING DNMT1 BLOCKADE, SMOKING MODELS SHOWED IMPROVED LUNG FUNCTION, PULMONARY APOPTOSIS, EMPHYSEMATOUS PROGRESSION, AND INCREASED BCL-2 PROTEIN LEVEL WITH LESS PROMOTER METHYLATION THAN EMPHYSEMA MICE. CONCLUSION: CIGARETTE-INDUCED OXIDATIVE STRESS MEDIATES PULMONARY APOPTOSIS AND HYPERMETHYLATION OF THE BCL-2 PROMOTER IN EMPHYSEMA MODELS THROUGH DNMT1. 2020 20 5975 32 TET1 IS AN IMPORTANT TRANSCRIPTIONAL ACTIVATOR OF TNFALPHA EXPRESSION IN MACROPHAGES. ACTIVATION OF MACROPHAGES AND OVEREXPRESSION OF TNFALPHA IS ASSOCIATED WITH THE PATHOGENESIS OF CHRONIC INFLAMMATORY DISEASES. HOWEVER, THE MECHANISMS LEADING TO TNFALPHA OVEREXPRESSION ARE STILL UNKNOWN. 5-METHYLOCYTOSINE (5-MC) IS AN EPIGENETIC MODIFICATION THAT IS ASSOCIATED WITH SILENCED GENES. RECENT STUDIES SHOWED THAT IT IS CONVERTED TO 5-HYDROXYLMETHYLOCYTOSINE (5-HMC) AND REACTIVATES GENE EXPRESSION THROUGH THE ACTION OF THE FAMILY OF TEN-ELEVEN-TRANSLOCATION (TET1-3) ENZYMES. IN THIS STUDY, WE SHOW THAT 5-HMC LEVELS ARE INCREASED GLOBALLY AND SPECIFICALLY IN THE TNFALPHA PROMOTER DURING THE DIFFERENTIATION OF MONOCYTES TO MACROPHAGES. IN ADDITION, THE LEVELS OF 5-HMC ARE INCREASED UPON LPS STIMULATION OF MACROPHAGES. FURTHERMORE, CRIPSR STABLE KNOCKOUT OF TET1 DECREASES THE EXPRESSION OF TNFALPHA AND OTHER PRO-INFLAMMATORY CYTOKINES. IN CONCLUSION, WE SHOWED THAT TET1 CONTRIBUTES TO THE ACTIVATION OF MACROPHAGES POSSIBLY THROUGH REGULATION OF 5-HYDROXYMETHYLATION IN THE PROMOTER OF PRO-INFLAMMATORY CYTOKINE GENES. THE TET1 ENZYME COULD BE A PROMISING THERAPEUTIC TARGET TO INHIBIT THE PERSISTENT INFLAMMATION CAUSED BY MACROPHAGES IN CHRONIC INFLAMMATORY DISEASES. 2019