1 1945 130 EPIGALLOCATECHIN-3-GALLATE, A HISTONE ACETYLTRANSFERASE INHIBITOR, INHIBITS EBV-INDUCED B LYMPHOCYTE TRANSFORMATION VIA SUPPRESSION OF RELA ACETYLATION. BECAUSE THE P300/CBP-MEDIATED HYPERACETYLATION OF RELA (P65) IS CRITICAL FOR NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) ACTIVATION, THE ATTENUATION OF P65 ACETYLATION IS A POTENTIAL MOLECULAR TARGET FOR THE PREVENTION OF CHRONIC INFLAMMATION. DURING OUR ONGOING SCREENING STUDY TO IDENTIFY NATURAL COMPOUNDS WITH HISTONE ACETYLTRANSFERASE INHIBITOR (HATI) ACTIVITY, WE IDENTIFIED EPIGALLOCATECHIN-3-GALLATE (EGCG) AS A NOVEL HATI WITH GLOBAL SPECIFICITY FOR THE MAJORITY OF HAT ENZYMES BUT WITH NO ACTIVITY TOWARD EPIGENETIC ENZYMES INCLUDING HDAC, SIRT1, AND HMTASE. AT A DOSE OF 100 MICROMOL/L, EGCG ABROGATES P300-INDUCED P65 ACETYLATION IN VITRO AND IN VIVO, INCREASES THE LEVEL OF CYTOSOLIC IKAPPABALPHA, AND SUPPRESSES TUMOR NECROSIS FACTOR ALPHA (TNFALPHA)-INDUCED NF-KAPPAB ACTIVATION. WE ALSO SHOWED THAT EGCG PREVENTS TNFALPHA-INDUCED P65 TRANSLOCATION TO THE NUCLEUS, CONFIRMING THAT HYPERACETYLATION IS CRITICAL FOR NF-KAPPAB TRANSLOCATION AS WELL AS ACTIVITY. FURTHERMORE, EGCG TREATMENT INHIBITED THE ACETYLATION OF P65 AND THE EXPRESSION OF NF-KAPPAB TARGET GENES IN RESPONSE TO DIVERSE STIMULI. FINALLY, EGCG REDUCED THE BINDING OF P300 TO THE PROMOTER REGION OF INTERLEUKIN-6 GENE WITH AN INCREASED RECRUITMENT OF HDAC3, WHICH HIGHLIGHTS THE IMPORTANCE OF THE BALANCE BETWEEN HATS AND HISTONE DEACETYLASES IN THE NF-KAPPAB-MEDIATED INFLAMMATORY SIGNALING PATHWAY. IMPORTANTLY, EGCG AT 50 MICROMOL/L DOSE COMPLETELY BLOCKS EBV INFECTION-INDUCED CYTOKINE EXPRESSION AND SUBSEQUENTLY THE EBV-INDUCED B LYMPHOCYTE TRANSFORMATION. THESE RESULTS SHOW THE CRUCIAL ROLE OF ACETYLATION IN THE DEVELOPMENT OF INFLAMMATORY-RELATED DISEASES. 2009 2 1906 39 ENHANCER OF ZESTE HOMOLOG 2-CATALYSED H3K27 TRIMETHYLATION PLAYS A KEY ROLE IN ACUTE-ON-CHRONIC LIVER FAILURE VIA TNF-MEDIATED PATHWAY. ACUTE-ON-CHRONIC LIVER FAILURE IS MAINLY DUE TO HOST IMMUNITY SELF-DESTRUCTION. THE HISTONE H3 LYSINE 27 (H3K27) TRIMETHYLATING ENZYME, ENHANCER OF ZESTE HOMOLOG 2 (EZH2) MEDIATES EPIGENETIC SILENCING OF GENE EXPRESSION AND REGULATES IMMUNITY, ALSO INVOLVES PATHOGENESIS OF SEVERAL LIVER DISEASES. THE CURRENT STUDY WAS TO DETERMINE THE ROLE OF METHYLTRANSFERASE EZH2 AND ITS CATALYSED H3K27 TRIMETHYLATION (H3K27ME3) IN LIVER FAILURE, AND TO FURTHER INVESTIGATE THE POTENTIAL TARGET FOR LIVER FAILURE TREATMENT. EZH2 AND ITS CATALYSED H3K27ME3 WERE DETERMINED IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) FROM LIVER FAILURE PATIENTS AND KUPFFER CELLS FROM EXPERIMENTAL MICE. FURTHERMORE, GSK126 (AN INHIBITOR FOR EZH2 TRIMETHYLATION FUNCTION) WAS APPLIED IN LIVER FAILURE MICE IN VIVO, AND LIPOPOLYSACCHARIDE-STIMULATED MONONUCLEAR CELLS IN VITRO. EZH2 AND H3K27ME3 WERE SIGNIFICANTLY UPREGULATED IN HUMAN PBMC FROM LIVER FAILURE PATIENTS OR MURINE KUPFFER CELLS FROM THE LIVER FAILURE ANIMALS, RESPECTIVELY. GSK126 AMELIORATED DISEASE SEVERITY IN LIVER FAILURE MICE, WHICH MAYBE ATTRIBUTE TO DOWN-REGULATE CIRCULATING AND HEPATIC PROINFLAMMATORY CYTOKINES, ESPECIALLY TNF VIA REDUCING H3K27ME3. IN-DEPTH CHROMATIN IMMUNOPRECIPITATION ANALYSIS UNRAVELLED THAT DECREASED ENRICHMENT OF H3K27ME3 ON TNF PROMOTOR, RESULTING IN TNF ELEVATION IN KUPFFER CELLS FROM LIVER FAILURE MICE. NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND PROTEIN KINASE B (AKT) SIGNALLING PATHWAYS WERE ACTIVATED UPON LIPOPOLYSACCHARIDE STIMULATION, BUT ATTENUATED BY USING GSK126, ACCOMPANIED WITH DECREASED TNF IN VITRO. IN CONCLUSION, EZH2 AND H3K27ME3 CONTRIBUTED TO THE PATHOGENESIS OF LIVER FAILURE VIA TRIGGERING TNF AND OTHER INDISPENSABLE PROINFLAMMATORY CYTOKINES. EZH2 WAS TO MODIFY H3K27ME3 ENRICHMENT, AS WELL AS, ACTIVATION OF THE DOWNSTREAM NF-KAPPAB AND AKT SIGNALLING PATHWAYS. 2018 3 4506 34 MRTF-A MEDIATES LPS-INDUCED PRO-INFLAMMATORY TRANSCRIPTION BY INTERACTING WITH THE COMPASS COMPLEX. 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-KAPPAB. 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-KAPPAB-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-KAPPAB-DEPENDENT MANNER. RECIPROCALLY, MRTF-A INFLUENCED THE NUCLEAR ENRICHMENT AND TARGET BINDING OF NF-KAPPAB. MECHANISTICALLY, MRTF-A WAS NECESSARY FOR THE ACCUMULATION OF ACTIVE HISTONE MODIFICATIONS ON NF-KAPPAB 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-KAPPAB 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. 2014 4 5715 42 SIRT3 RESTRICTS HEPATITIS B VIRUS TRANSCRIPTION AND REPLICATION THROUGH EPIGENETIC REGULATION OF COVALENTLY CLOSED CIRCULAR DNA INVOLVING SUPPRESSOR OF VARIEGATION 3-9 HOMOLOG 1 AND SET DOMAIN CONTAINING 1A HISTONE METHYLTRANSFERASES. HEPATITIS B VIRUS (HBV) INFECTION REMAINS A MAJOR HEALTH PROBLEM WORLDWIDE. MAINTENANCE OF THE COVALENTLY CLOSED CIRCULAR DNA (CCCDNA), WHICH SERVES AS A TEMPLATE FOR HBV RNA TRANSCRIPTION, IS RESPONSIBLE FOR THE FAILURE OF ERADICATING CHRONIC HBV DURING CURRENT ANTIVIRAL THERAPY. CCCDNA IS ASSEMBLED WITH CELLULAR HISTONE PROTEINS INTO CHROMATIN, BUT LITTLE IS KNOWN ABOUT THE REGULATION OF HBV CHROMATIN BY HISTONE POSTTRANSLATIONAL MODIFICATIONS. IN THIS STUDY, WE IDENTIFIED SILENT MATING TYPE INFORMATION REGULATION 2 HOMOLOG 3 (SIRT3) AS A HOST FACTOR RESTRICTING HBV TRANSCRIPTION AND REPLICATION BY SCREENING SEVEN MEMBERS OF THE SIRTUIN FAMILY, WHICH IS THE CLASS III HISTONE DEACETYLASE. ECTOPIC SIRT3 EXPRESSION SIGNIFICANTLY REDUCED TOTAL HBV RNAS, 3.5-KB RNA, AS WELL AS REPLICATIVE INTERMEDIATE DNA IN HBV-INFECTED HEPG2-NA(+) /TAUROCHOLATE COTRANSPORTING POLYPEPTIDE CELLS AND PRIMARY HUMAN HEPATOCYTES. IN CONTRAST, GENE SILENCING OF SIRT3 PROMOTED HBV TRANSCRIPTION AND REPLICATION. A MECHANISTIC STUDY FOUND THAT NUCLEAR SIRT3 WAS RECRUITED TO THE HBV CCCDNA, WHERE IT DEACETYLATED HISTONE 3 LYSINE 9. IMPORTANTLY, OCCUPANCY OF SIRT3 ON CCCDNA COULD INCREASE THE RECRUITMENT OF HISTONE METHYLTRANSFERASE SUPPRESSOR OF VARIEGATION 3-9 HOMOLOG 1 TO CCCDNA AND DECREASE RECRUITMENT OF SET DOMAIN CONTAINING 1A, LEADING TO A MARKED INCREASE OF TRIMETHYL-HISTONE H3 (LYS9) AND A DECREASE OF TRIMETHYL-HISTONE H3 (LYS4) ON CCCDNA. MOREOVER, SIRT3-MEDIATED HBV CCCDNA TRANSCRIPTIONAL REPRESSION INVOLVED DECREASED BINDING OF HOST RNA POLYMERASE II AND TRANSCRIPTION FACTOR YIN YANG 1 TO CCCDNA. FINALLY, HEPATITIS B VIRAL X PROTEIN COULD RELIEVE SIRT3-MEDIATED CCCDNA TRANSCRIPTIONAL REPRESSION BY INHIBITING BOTH SIRT3 EXPRESSION AND ITS RECRUITMENT TO CCCDNA. CONCLUSION: SIRT3 IS A HOST FACTOR EPIGENETICALLY RESTRICTING HBV CCCDNA TRANSCRIPTION BY ACTING COOPERATIVELY WITH HISTONE METHYLTRANSFERASE; THESE DATA PROVIDE A RATIONALE FOR THE USE OF SIRT3 ACTIVATORS IN THE PREVENTION OR TREATMENT OF HBV INFECTION. (HEPATOLOGY 2018). 2018 5 2370 37 EPIGENETIC REGULATION OF THE ALTERNATIVELY ACTIVATED MACROPHAGE PHENOTYPE. ALTERNATIVELY ACTIVATED (M2) MACROPHAGES PLAY CRITICAL ROLES IN DIVERSE CHRONIC DISEASES, INCLUDING PARASITE INFECTIONS, CANCER, AND ALLERGIC RESPONSES. HOWEVER, LITTLE IS KNOWN ABOUT THE ACQUISITION AND MAINTENANCE OF THEIR PHENOTYPE. WE REPORT THAT M2-MACROPHAGE MARKER GENES ARE EPIGENETICALLY REGULATED BY RECIPROCAL CHANGES IN HISTONE H3 LYSINE-4 (H3K4) AND HISTONE H3 LYSINE-27 (H3K27) METHYLATION; AND THE LATTER METHYLATION MARKS ARE REMOVED BY THE H3K27 DEMETHYLASE JUMONJI DOMAIN CONTAINING 3 (JMJD3). WE FOUND THAT CONTINUOUS INTERLEUKIN-4 (IL-4) TREATMENT LEADS TO DECREASED H3K27 METHYLATION, AT THE PROMOTER OF M2 MARKER GENES, AND A CONCOMITANT INCREASE IN JMJD3 EXPRESSION. FURTHERMORE, WE DEMONSTRATE THAT IL-4-DEPENDENT JMJD3 EXPRESSION IS MEDIATED BY STAT6, A MAJOR TRANSCRIPTION FACTOR OF IL-4-MEDIATED SIGNALING. AFTER IL-4 STIMULATION, ACTIVATED STAT6 IS INCREASED AND BINDS TO CONSENSUS SITES AT THE JMJD3 PROMOTER. INCREASED JMJD3 CONTRIBUTES TO THE DECREASE OF H3K27 DIMETHYLATION AND TRIMETHYLATION (H3K27ME2/3) MARKS AS WELL AS THE TRANSCRIPTIONAL ACTIVATION OF SPECIFIC M2 MARKER GENES. THE DECREASE IN H3K27ME2/3 AND INCREASE IN JMJD3 RECRUITMENT WERE CONFIRMED BY IN VIVO STUDIES USING A SCHISTOSOMA MANSONI EGG-CHALLENGED MOUSE MODEL, A WELL-STUDIED SYSTEM KNOWN TO SUPPORT AN M2 PHENOTYPE. COLLECTIVELY, THESE DATA INDICATE THAT CHROMATIN REMODELING IS MECHANISTICALLY IMPORTANT IN THE ACQUISITION OF THE M2-MACROPHAGE PHENOTYPE. 2009 6 4546 36 MUTANT P53 REGULATES ENHANCER-ASSOCIATED H3K4 MONOMETHYLATION THROUGH INTERACTIONS WITH THE METHYLTRANSFERASE MLL4. MONOMETHYLATION OF HISTONE H3 LYSINE 4 (H3K4ME1) IS ENRICHED AT ENHANCERS THAT ARE PRIMED FOR ACTIVATION AND THE LEVELS OF THIS HISTONE MARK ARE FREQUENTLY ALTERED IN VARIOUS HUMAN CANCERS. YET, HOW ALTERATIONS IN H3K4ME1 ARE ESTABLISHED AND THE CONSEQUENCES OF THESE EPIGENETIC CHANGES IN TUMORIGENESIS ARE NOT WELL UNDERSTOOD. USING CHIP-SEQ IN HUMAN COLON CANCER CELLS, WE DEMONSTRATE THAT MUTANT P53 DEPLETION RESULTS IN DECREASED H3K4ME1 LEVELS AT ACTIVE ENHANCERS THAT REVEAL A STRIKING COLOCALIZATION OF MUTANT P53 AND THE H3K4 MONOMETHYLTRANSFERASE MLL4 FOLLOWING CHRONIC TUMOR NECROSIS FACTOR ALPHA (TNFALPHA) SIGNALING. WE FURTHER REVEAL THAT MUTANT P53 FORMS PHYSIOLOGICAL ASSOCIATIONS AND DIRECT INTERACTIONS WITH MLL4 AND PROMOTES THE ENHANCER BINDING OF MLL4, WHICH IS REQUIRED FOR TNFALPHA-INDUCIBLE H3K4ME1 AND HISTONE H3 LYSINE 27 ACETYLATION (H3K27AC) LEVELS, ENHANCER-DERIVED TRANSCRIPT (ERNA) SYNTHESIS, AND MUTANT P53-DEPENDENT TARGET GENE ACTIVATION. COMPLEMENTARY IN VITRO STUDIES WITH RECOMBINANT CHROMATIN AND PURIFIED PROTEINS DEMONSTRATE THAT BINDING OF THE MLL3/4 COMPLEX AND H3K4ME1 DEPOSITION IS ENHANCED BY MUTANT P53 AND P300-MEDIATED ACETYLATION, WHICH IN TURN REFLECTS A MLL3/4-DEPENDENT ENHANCEMENT OF MUTANT P53 AND P300-DEPENDENT TRANSCRIPTIONAL ACTIVATION. COLLECTIVELY, OUR FINDINGS ESTABLISH A MECHANISM IN WHICH MUTANT P53 COOPERATES WITH MLL4 TO REGULATE ABERRANT ENHANCER ACTIVITY AND TUMOR-PROMOTING GENE EXPRESSION IN RESPONSE TO CHRONIC IMMUNE SIGNALING. 2018 7 699 36 BROMODOMAIN PROTEIN 4 IS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HEPATIC STELLATE CELL ACTIVATION. LIVER FIBROSIS IS CHARACTERIZED BY THE EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX IN LIVER. CHRONIC LIVER INJURY INDUCES THE ACTIVATION OF HEPATIC STELLATE CELL (HSCS), A KEY STEP IN LIVER FIBROGENESIS. THE ACTIVATED HSC IS THE PRIMARY SOURCE OF ECM AND CONTRIBUTES SIGNIFICANTLY TO LIVER FIBROSIS. TGFBETA1 IS THE MOST POTENT PRO-FIBROTIC CYTOKINE. BROMODOMAIN PROTEIN 4 (BRD4), AN EPIGENETIC READER OF HISTONE ACETYLATION MARKS, WAS CRUCIAL FOR PROFIBROTIC GENE EXPRESSION IN HSCS. THE PRESENT STUDY AIMED TO INVESTIGATE THE ROLES OF BRD4 IN TGFBETA1-DEPENDENT HSC ACTIVATION AND LIVER FIBROSIS, FOCUSING ON TGFBETA1-INDUCED ALTERATIONS OF THE LEVELS OF THE FIBROTIC-RELATED IMPORTANT PROTEINS IN HSCS BY EMPLOYING THE HETEROZYGOUS TGFBETA1 KNOCKOUT MICE AND BRD4 KNOCKDOWN IN VIVO AND IN VITRO. RESULTS REVEALED THAT BRD4 PROTEIN LEVEL WAS SIGNIFICANTLY UPREGULATED BY TGFBETA1 AND BRD4 KNOCKDOWN REDUCED TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. BRD4 WAS REQUIRED FOR THE INFLUENCES OF TGFBETA1 ON PDGFBETA RECEPTOR AND ON THE PATHWAYS OF SMAD3, STAT3, AND AKT. BRD4 ALSO MEDIATED TGFBETA1-INDUCED INCREASES IN HISTONE ACETYLTRANSFERASE P300, THE PIVOTAL PRO-INFLAMMATORY NFKB P65, AND TISSUE INHIBITOR OF METALLOPROTEINASE 1 WHEREAS BRD4 REDUCED CASPASE-3 PROTEIN LEVELS IN HSCS DURING LIVER INJURY, INDEPENDENT OF TGFBETA1. FURTHER EXPERIMENTS INDICATED THE INTERACTION BETWEEN TGFBETA1-INDUCED BRD4 AND NFKB P65 IN HSCS AND IN LIVER OF TAA-INDUCED LIVER INJURY. HUMAN CIRRHOTIC LIVERS WERE DEMONSTRATED A PARALLEL INCREASE IN THE PROTEIN LEVELS OF BRD4 AND NFKB P65 IN HSCS. THIS STUDY REVEALED THAT BRD4 WAS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. 2023 8 1667 38 DOWNREGULATION OF PCAF BY MIR-181A/B PROVIDES FEEDBACK REGULATION TO TNF-ALPHA-INDUCED TRANSCRIPTION OF PROINFLAMMATORY GENES IN LIVER EPITHELIAL CELLS. ABERRANT CELLULAR RESPONSES TO PROINFLAMMATORY CYTOKINES, SUCH AS TNF-ALPHA, ARE PATHOGENIC FEATURES IN MOST CHRONIC INFLAMMATORY DISEASES. A VARIETY OF EXTRACELLULAR AND INTRACELLULAR FEEDBACK PATHWAYS HAS EVOLVED TO PREVENT AN INAPPROPRIATE CELLULAR REACTION TO THESE PROINFLAMMATORY CYTOKINES. IN THIS STUDY, WE REPORT THAT TNF-ALPHA TREATMENT OF HUMAN AND MOUSE CHOLANGIOCYTES AND HEPATOCYTES DOWNREGULATED EXPRESSION OF P300/CBP-ASSOCIATED FACTOR (PCAF), A COACTIVATOR AND AN ACETYLTRANSFERASE THAT PROMOTES HISTONE ACETYLATION AND GENE TRANSCRIPTION. OF THESE UPREGULATED MICRORNAS IN TNF-ALPHA-TREATED CELLS, MIR-181A/B (MIR-181A AND MIR-181B) SUPPRESSED TRANSLATION OF PCAF MRNA. FUNCTIONAL MANIPULATION OF MIR-181A/B CAUSED RECIPROCAL ALTERATIONS IN PCAF PROTEIN EXPRESSION IN CULTURED CHOLANGIOCYTES AND HEPATOCYTES. INHIBITION OF MIR-181A/B FUNCTION WITH ANTI-MIRS BLOCKED TNF-ALPHA-INDUCED SUPPRESSION OF PCAF EXPRESSION. PROMOTER RECRUITMENT OF PCAF WAS SHOWN TO BE ASSOCIATED WITH TNF-ALPHA-INDUCED TRANSCRIPTION OF INFLAMMATORY GENES. INTRIGUINGLY, PRETREATMENT OF CELLS WITH TNF-ALPHA INHIBITED TRANSCRIPTION OF INFLAMMATORY GENES IN RESPONSE TO SUBSEQUENT TNF-ALPHA STIMULATION. OVEREXPRESSION OF PCAF OR INHIBITION OF MIR-181A/B FUNCTION WITH ANTI-MIRS ATTENUATED THE INHIBITORY EFFECTS OF TNF-ALPHA PRETREATMENT ON EPITHELIAL INFLAMMATORY RESPONSE TO SUBSEQUENT TNF-ALPHA STIMULATION. DOWNREGULATION OF PCAF AND THE INHIBITORY EFFECTS OF TNF-ALPHA PRETREATMENT ON LIVER EPITHELIAL INFLAMMATORY RESPONSE WERE FURTHER CONFIRMED IN A MOUSE MODEL OF TNF-ALPHA I.P. INJECTION. THESE DATA SUGGEST THAT PCAF IS A TARGET FOR MIR-181A/B, AND DOWNREGULATION OF PCAF BY TNF-ALPHA PROVIDES NEGATIVE FEEDBACK REGULATION TO INFLAMMATORY REACTIONS IN LIVER EPITHELIAL CELLS, A PROCESS THAT MAY BE RELEVANT TO THE EPIGENETIC FINE-TUNING OF EPITHELIAL INFLAMMATORY PROCESSES IN GENERAL. 2012 9 6599 26 TWIST1 AND TWIST2 INDUCE HUMAN MACROPHAGE MEMORY UPON CHRONIC INNATE RECEPTOR TREATMENT BY HDAC-MEDIATED DEACETYLATION OF CYTOKINE PROMOTERS. INTESTINAL TISSUES ARE CONTINUOUSLY EXPOSED TO MICROBIAL PRODUCTS THAT STIMULATE PATTERN-RECOGNITION RECEPTORS (PRRS). ONGOING PRR STIMULATION CAN CONFER EPIGENETIC CHANGES IN MACROPHAGES, WHICH CAN THEN REGULATE SUBSEQUENT IMMUNE OUTCOMES AND ADAPTATION TO THE LOCAL ENVIRONMENT. MECHANISMS LEADING TO THESE CHANGES ARE INCOMPLETELY UNDERSTOOD. WE FOUND THAT SHORT-TERM STIMULATION OF THE PRR NOD2 IN PRIMARY HUMAN MONOCYTE-DERIVED MACROPHAGES RESULTED IN INCREASED H3 AND H4 ACETYLATION OF CYTOKINE PROMOTERS, CONSISTENT WITH THE INCREASED CYTOKINE SECRETION OBSERVED. HOWEVER, WITH PROLONGED NOD2 STIMULATION, BOTH THE ACETYLATION AND CYTOKINE SECRETION WERE DRAMATICALLY DECREASED. CHRONIC NOD2 STIMULATION UPREGULATED THE TRANSCRIPTION FACTORS TWIST1 AND TWIST2, WHICH BOUND TO THE PROMOTERS OF THE HISTONE DEACETYLASES HDAC1 AND HDAC3 AND INDUCED HDAC1 AND HDAC3 EXPRESSION. HDAC1 AND HDAC3 THEN MEDIATED HISTONE DEACETYLATION AT CYTOKINE PROMOTERS AND, IN TURN, CYTOKINE DOWNREGULATION UNDER THESE CONDITIONS. SIMILAR REGULATION WAS OBSERVED UPON CHRONIC STIMULATION OF MULTIPLE PRRS. CONSISTENT WITH THE CHRONIC MICROBIAL EXPOSURE IN THE INTESTINAL ENVIRONMENT, TWIST1, TWIST2, HDAC1, AND HDAC3 WERE UPREGULATED IN HUMAN INTESTINAL RELATIVE TO PERIPHERAL MACROPHAGES. IMPORTANTLY, COMPLEMENTING HDAC1 AND HDAC3 IN TWIST1/TWIST2-DEFICIENT MONOCYTE-DERIVED MACROPHAGES RESTORED THE REDUCED HISTONE ACETYLATION ON CYTOKINE PROMOTERS AND THE DECREASED CYTOKINE SECRETION WITH CHRONIC NOD2 STIMULATION. TAKEN TOGETHER, WE IDENTIFY MECHANISMS WHEREIN TWIST1 AND TWIST2 PROMOTE CHROMATIN MODIFICATIONS, RESULTING IN MACROPHAGE INSTRUCTION AND ADAPTATION TO CONDITIONS IN THE INTESTINAL MICROENVIRONMENT. 2019 10 2425 26 EPIGENETIC SILENCING OF IRF1 DYSREGULATES TYPE III INTERFERON RESPONSES TO RESPIRATORY VIRUS INFECTION IN EPITHELIAL TO MESENCHYMAL TRANSITION. CHRONIC OXIDATIVE INJURY PRODUCED BY AIRWAY DISEASE TRIGGERS A TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA)-MEDIATED EPIGENETIC REPROGRAMMING KNOWN AS THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT). WE OBSERVE THAT EMT SILENCES PROTECTIVE MUCOSAL INTERFERON (IFN)-I AND III PRODUCTION ASSOCIATED WITH ENHANCED RHINOVIRUS (RV) AND RESPIRATORY SYNCYTIAL VIRUS (RSV) REPLICATION. MESENCHYMAL TRANSITIONED CELLS ARE DEFECTIVE IN INDUCIBLE INTERFERON REGULATORY FACTOR 1 (IRF1) EXPRESSION BY OCCLUDING RELA AND IRF3 ACCESS TO THE PROMOTER. IRF1 IS NECESSARY FOR THE EXPRESSION OF TYPE III IFNS (IFNLS 1 AND 2/3). INDUCED BY THE EMT, ZINC FINGER E-BOX BINDING HOMEOBOX 1 (ZEB1) BINDS AND SILENCES IRF1. ECTOPIC ZEB1 IS SUFFICIENT FOR IRF1 SILENCING, WHEREAS ZEB1 KNOCKDOWN PARTIALLY RESTORES IRF1-IFNL UPREGULATION. ZEB1 SILENCES IRF1 THROUGH THE CATALYTIC ACTIVITY OF THE ENHANCER OF ZESTE 2 POLYCOMB REPRESSIVE COMPLEX 2 SUBUNIT (EZH2), FORMING REPRESSIVE H3K27(ME3) MARKS. WE OBSERVE THAT IRF1 EXPRESSION IS MEDIATED BY ZEB1 DE-REPRESSION, AND OUR STUDY DEMONSTRATES HOW AIRWAY REMODELLING/FIBROSIS IS ASSOCIATED WITH A DEFECTIVE MUCOSAL ANTIVIRAL RESPONSE THROUGH ZEB1-INITIATED EPIGENETIC SILENCING. 2017 11 6015 29 THE ARGININE METHYLTRANSFERASE PRMT7 PROMOTES EXTRAVASATION OF MONOCYTES RESULTING IN TISSUE INJURY IN COPD. EXTRAVASATION OF MONOCYTES INTO TISSUE AND TO THE SITE OF INJURY IS A FUNDAMENTAL IMMUNOLOGICAL PROCESS, WHICH REQUIRES RAPID RESPONSES VIA POST TRANSLATIONAL MODIFICATIONS (PTM) OF PROTEINS. PROTEIN ARGININE METHYLTRANSFERASE 7 (PRMT7) IS AN EPIGENETIC FACTOR THAT HAS THE CAPACITY TO MONO-METHYLATE HISTONES ON ARGININE RESIDUES. HERE WE SHOW THAT IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS, PRMT7 EXPRESSION IS ELEVATED IN THE LUNG TISSUE AND LOCALIZED TO THE MACROPHAGES. IN MOUSE MODELS OF COPD, LUNG FIBROSIS AND SKIN INJURY, REDUCED EXPRESSION OF PRMT7 ASSOCIATES WITH DECREASED RECRUITMENT OF MONOCYTES TO THE SITE OF INJURY AND HENCE LESS SEVERE SYMPTOMS. MECHANISTICALLY, ACTIVATION OF NF-KAPPAB/RELA IN MONOCYTES INDUCES PRMT7 TRANSCRIPTION AND CONSEQUENTIAL MONO-METHYLATION OF HISTONES AT THE REGULATORY ELEMENTS OF RAP1A, WHICH LEADS TO INCREASED TRANSCRIPTION OF THIS GENE THAT IS RESPONSIBLE FOR ADHESION AND MIGRATION OF MONOCYTES. PERSISTENT MONOCYTE-DERIVED MACROPHAGE ACCUMULATION LEADS TO ALOX5 OVER-EXPRESSION AND ACCUMULATION OF ITS METABOLITE LTB4, WHICH TRIGGERS EXPRESSION OF ACSL4 A FERROPTOSIS PROMOTING GENE IN LUNG EPITHELIAL CELLS. CONCLUSIVELY, INHIBITION OF ARGININE MONO-METHYLATION MIGHT OFFER TARGETED INTERVENTION IN MONOCYTE-DRIVEN INFLAMMATORY CONDITIONS THAT LEAD TO EXTENSIVE TISSUE DAMAGE IF LEFT UNTREATED. 2022 12 2117 36 EPIGENETIC HISTONE METHYLATION MODULATES FIBROTIC GENE EXPRESSION. TGF-BETA1-INDUCED EXPRESSION OF EXTRACELLULAR MATRIX (ECM) GENES PLAYS A MAJOR ROLE IN THE DEVELOPMENT OF CHRONIC RENAL DISEASES SUCH AS DIABETIC NEPHROPATHY. ALTHOUGH MANY KEY TRANSCRIPTION FACTORS ARE KNOWN, MECHANISMS INVOLVING THE NUCLEAR CHROMATIN THAT MODULATE ECM GENE EXPRESSION REMAIN UNCLEAR. HERE, WE EXAMINED THE ROLE OF EPIGENETIC CHROMATIN MARKS SUCH AS HISTONE H3 LYSINE METHYLATION (H3KME) IN TGF-BETA1-INDUCED GENE EXPRESSION IN RAT MESANGIAL CELLS UNDER NORMAL AND HIGH-GLUCOSE (HG) CONDITIONS. TGF-BETA1 INCREASED THE EXPRESSION OF THE ECM-ASSOCIATED GENES CONNECTIVE TISSUE GROWTH FACTOR, COLLAGEN-ALPHA1[IOTA], AND PLASMINOGEN ACTIVATOR INHIBITOR-1. INCREASED LEVELS OF CHROMATIN MARKS ASSOCIATED WITH ACTIVE GENES (H3K4ME1, H3K4ME2, AND H3K4ME3), AND DECREASED LEVELS OF REPRESSIVE MARKS (H3K9ME2 AND H3K9ME3) AT THESE GENE PROMOTERS ACCOMPANIED THESE CHANGES IN EXPRESSION. TGF-BETA1 ALSO INCREASED EXPRESSION OF THE H3K4 METHYLTRANSFERASE SET7/9 AND RECRUITMENT TO THESE PROMOTERS. SET7/9 GENE SILENCING WITH SIRNAS SIGNIFICANTLY ATTENUATED TGF-BETA1-INDUCED ECM GENE EXPRESSION. FURTHERMORE, A TGF-BETA1 ANTIBODY NOT ONLY BLOCKED HG-INDUCED ECM GENE EXPRESSION BUT ALSO REVERSED HG-INDUCED CHANGES IN PROMOTER H3KME LEVELS AND SET7/9 OCCUPANCY. TAKEN TOGETHER, THESE RESULTS SHOW THE FUNCTIONAL ROLE OF EPIGENETIC CHROMATIN HISTONE H3KME IN TGF-BETA1-MEDIATED ECM GENE EXPRESSION IN MESANGIAL CELLS UNDER NORMAL AND HG CONDITIONS. PHARMACOLOGIC AND OTHER THERAPIES THAT REVERSE THESE MODIFICATIONS COULD HAVE POTENTIAL RENOPROTECTIVE EFFECTS FOR DIABETIC NEPHROPATHY. 2010 13 3246 26 HEPATITIS B VIRUS (HBV) INDUCES THE EXPRESSION OF INTERLEUKIN-8 THAT IN TURN REDUCES HBV SENSITIVITY TO INTERFERON-ALPHA. HIGH LEVELS OF SERUM INTERLEUKIN-8 (IL-8) HAVE BEEN DETECTED IN CHRONIC HEPATITIS B (CHB) PATIENTS DURING EPISODES OF HEPATITIS FLARES. WE INVESTIGATED WHETHER HEPATITIS B VIRUS (HBV) MAY DIRECTLY INDUCE IL-8 PRODUCTION AND WHETHER IL-8 MAY ANTAGONIZE INTERFERON-ALPHA (IFN-ALPHA) ANTIVIRAL ACTIVITY AGAINST HBV. WE SHOWED THAT CHB PATIENTS HAD SIGNIFICANTLY HIGHER IL-8 LEVELS BOTH IN SERUM AND IN LIVER TISSUE THAN CONTROLS. IN HBV-REPLICATING HEPG2 CELLS, IL-8 TRANSCRIPTION WAS SIGNIFICANTLY ACTIVATED. AP-1, C/EBP AND NF-KB TRANSCRIPTION FACTORS WERE CONCURRENTLY NECESSARY FOR MAXIMUM IL-8 INDUCTION. MOREOVER, HBX VIRAL PROTEIN WAS RECRUITED ONTO THE IL-8 PROMOTER AND THIS WAS PARALLELED BY IL8-BOUND HISTONE HYPERACETYLATION AND BY ACTIVE RECRUITMENT OF TRANSCRIPTIONAL COACTIVATORS. INHIBITION OF IL-8 INCREASES THE ANTIVIRAL ACTIVITY OF IFN-ALPHA AGAINST HBV. OUR RESULTS INDICATE THAT HBV ACTIVATES IL-8 GENE EXPRESSION BY TARGETING THE EPIGENETIC REGULATION OF THE IL-8 PROMOTER AND THAT IL-8 MAY CONTRIBUTE TO REDUCE HBV SENSITIVITY TO IFN-ALPHA. 2013 14 3189 28 HBX RELIEVES CHROMATIN-MEDIATED TRANSCRIPTIONAL REPRESSION OF HEPATITIS B VIRAL CCCDNA INVOLVING SETDB1 HISTONE METHYLTRANSFERASE. BACKGROUND & AIMS: MAINTENANCE OF THE COVALENTLY CLOSED CIRCULAR HBV DNA (CCCDNA) THAT SERVES AS A TEMPLATE FOR HBV TRANSCRIPTION IS RESPONSIBLE FOR THE FAILURE OF ANTIVIRAL THERAPIES. WHILE STUDIES IN CHRONIC HEPATITIS PATIENTS HAVE SHOWN THAT HIGH VIREMIA CORRELATES WITH HYPERACETYLATION OF CCCDNA-ASSOCIATED HISTONES, THE MOLECULAR MECHANISMS CONTROLLING CCCDNA STABILITY AND TRANSCRIPTIONAL REGULATION ARE STILL POORLY UNDERSTOOD. THIS STUDY AIMED TO DECIPHER THE ROLE OF CHROMATIN AND CHROMATIN MODIFIER PROTEINS ON HBV TRANSCRIPTION. METHODS: WE ANALYZED THE CHROMATIN STRUCTURE OF ACTIVELY TRANSCRIBED OR SILENCED CCCDNA BY INFECTING PRIMARY HUMAN HEPATOCYTES AND DIFFERENTIATED HEPARG CELLS WITH WILD-TYPE VIRUS OR VIRUS DEFICIENT (HBVX-) FOR THE EXPRESSION OF HEPATITIS B VIRUS X PROTEIN (HBX), THAT IS REQUIRED FOR HBV EXPRESSION. RESULTS: IN THE ABSENCE OF HBX, HBV CCCDNA WAS TRANSCRIPTIONALLY SILENCED WITH THE CONCOMITANT DECREASE OF HISTONE 3 (H3) ACETYLATION AND H3K4ME3, INCREASE OF H3 DI- AND TRI-METHYLATION (H3K9ME) AND THE RECRUITMENT OF HETEROCHROMATIN PROTEIN 1 FACTORS (HP1) THAT CORRELATE WITH CONDENSED CHROMATIN. SETDB1 WAS FOUND TO BE THE MAIN HISTONE METHYLTRANSFERASE RESPONSIBLE FOR THE DEPOSITION OF H3K9ME3 AND HBV REPRESSION. FINALLY, FULL TRANSCRIPTIONAL REACTIVATION OF HBVX- UPON HBX RE-EXPRESSION CORRELATED WITH AN INCREASE OF HISTONE ACETYLATION AND H3K4ME3, AND A CONCOMITANT DECREASE OF HP1 BINDING AND OF H3K9ME3 ON THE CCCDNA. CONCLUSION: UPON HBV INFECTION, CELLULAR MECHANISMS INVOLVING SETDB1-MEDIATED H3K9ME3 AND HP1 INDUCE SILENCING OF HBV CCCDNA TRANSCRIPTION THROUGH MODULATION OF CHROMATIN STRUCTURE. HBX IS ABLE TO RELIEVE THIS REPRESSION AND ALLOW THE ESTABLISHMENT OF ACTIVE CHROMATIN. 2015 15 3357 31 HISTONE H3 LYSINE 9 DI-METHYLATION AS AN EPIGENETIC SIGNATURE OF THE INTERFERON RESPONSE. EFFECTIVE ANTIVIRAL IMMUNITY DEPENDS ON THE ABILITY OF INFECTED CELLS OR CELLS TRIGGERED WITH VIRUS-DERIVED NUCLEIC ACIDS TO PRODUCE TYPE I INTERFERON (IFN), WHICH ACTIVATES TRANSCRIPTION OF NUMEROUS ANTIVIRAL GENES. HOWEVER, DISPROPORTIONATELY STRONG OR CHRONIC IFN EXPRESSION IS A COMMON CAUSE OF INFLAMMATORY AND AUTOIMMUNE DISEASES. WE DESCRIBE AN EPIGENETIC MECHANISM THAT DETERMINES CELL TYPE-SPECIFIC DIFFERENCES IN IFN AND IFN-STIMULATED GENE (ISG) EXPRESSION IN RESPONSE TO EXOGENOUS SIGNALS. WE IDENTIFY DI-METHYLATION OF HISTONE H3 AT LYSINE 9 (H3K9ME2) AS A SUPPRESSOR OF IFN AND IFN-INDUCIBLE ANTIVIRAL GENE EXPRESSION. WE SHOW THAT LEVELS OF H3K9ME2 AT IFN AND ISG CORRELATE INVERSELY WITH THE SCOPE AND AMPLITUDE OF IFN AND ISG EXPRESSION IN FIBROBLASTS AND DENDRITIC CELLS. ACCORDINGLY, GENETIC ABLATION OR PHARMACOLOGICAL INACTIVATION OF LYSINE METHYLTRANSFERASE G9A, WHICH IS ESSENTIAL FOR THE GENERATION OF H3K9ME2, RESULTED IN PHENOTYPIC CONVERSION OF FIBROBLASTS INTO HIGHLY POTENT IFN-PRODUCING CELLS AND RENDERED THESE CELLS RESISTANT TO PATHOGENIC RNA VIRUSES. IN SUMMARY, OUR STUDIES IMPLICATE H3K9ME2 AND ENZYMES CONTROLLING ITS ABUNDANCE AS KEY REGULATORS OF INNATE ANTIVIRAL IMMUNITY. 2012 16 5795 37 STAT3 INDUCTION OF MIR-146B FORMS A FEEDBACK LOOP TO INHIBIT THE NF-KAPPAB TO IL-6 SIGNALING AXIS AND STAT3-DRIVEN CANCER PHENOTYPES. INTERLEUKIN-6 (IL-6)-MEDIATED ACTIVATION OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) IS A MECHANISM BY WHICH CHRONIC INFLAMMATION CAN CONTRIBUTE TO CANCER AND IS A COMMON ONCOGENIC EVENT. WE DISCOVERED A PATHWAY, THE LOSS OF WHICH IS ASSOCIATED WITH PERSISTENT STAT3 ACTIVATION IN HUMAN CANCER. WE FOUND THAT THE GENE ENCODING THE TUMOR SUPPRESSOR MICRORNA MIR-146B IS A DIRECT STAT3 TARGET GENE, AND ITS EXPRESSION WAS INCREASED IN NORMAL BREAST EPITHELIAL CELLS BUT DECREASED IN TUMOR CELLS. METHYLATION OF THE MIR-146B PROMOTER, WHICH INHIBITED STAT3-MEDIATED INDUCTION OF EXPRESSION, WAS INCREASED IN PRIMARY BREAST CANCERS. MOREOVER, WE FOUND THAT MIR-146B INHIBITED NUCLEAR FACTOR KAPPAB (NF-KAPPAB)-DEPENDENT PRODUCTION OF IL-6, SUBSEQUENT STAT3 ACTIVATION, AND IL-6/STAT3-DRIVEN MIGRATION AND INVASION IN BREAST CANCER CELLS, THEREBY ESTABLISHING A NEGATIVE FEEDBACK LOOP. IN ADDITION, HIGHER EXPRESSION OF MIR-146B WAS POSITIVELY CORRELATED WITH PATIENT SURVIVAL IN BREAST CANCER SUBTYPES WITH INCREASED IL6 EXPRESSION AND STAT3 PHOSPHORYLATION. OUR RESULTS IDENTIFY AN EPIGENETIC MECHANISM OF CROSSTALK BETWEEN STAT3 AND NF-KAPPAB RELEVANT TO CONSTITUTIVE STAT3 ACTIVATION IN MALIGNANCY AND THE ROLE OF INFLAMMATION IN ONCOGENESIS. 2014 17 1764 34 EARLY-IMMEDIATE GENE EGR1 IS ASSOCIATED WITH TGFBETA1 REGULATION OF EPIGENETIC READER BROMODOMAIN-CONTAINING PROTEIN 4 VIA THE CANONICAL SMAD3 SIGNALING IN HEPATIC STELLATE CELLS IN VITRO AND IN VIVO. UPON CHRONIC DAMAGE TO THE LIVER, MULTIPLE CYTOKINES STIMULATE HEPATIC STELLATE CELLS (HSCS), CAUSING THE ALTERATIONS OF GENE EXPRESSION PROFILES AND THUS LEADING TO HSC ACTIVATION, A KEY STEP IN LIVER FIBROGENESIS. ACTIVATED HSCS ARE THE DOMINANT CONTRIBUTORS TO LIVER FIBROSIS. BROMODOMAIN CONTAINING PROTEIN 4 (BRD4), AN IMPORTANT EPIGENETIC READER, WAS DEMONSTRATED TO CONCENTRATE ON HUNDREDS OF ENHANCERS ASSOCIATED WITH GENES INVOLVED IN MULTIPLE PROFIBROTIC PATHWAYS, THEREBY DIRECTING HSC ACTIVATION AND THE FIBROTIC RESPONSES. THE PRESENT STUDIES WERE DESIGNED TO EXAMINE THE EFFECT OF TRANSFORMING GROWTH FACTOR BETA-1 (TGFBETA1), THE MOST POTENT PRO-FIBROTIC CYTOKINE, ON BRD4 EXPRESSION IN HSCS AND, IF SO, ELUCIDATED THE UNDERLYING MECHANISMS IN VITRO AND IN VIVO. THE EXPERIMENTS EMPLOYED THE HETEROGENEOUS TGFBETA1 KNOCKOUT (TGFBETA1(+/-) ) MICE, GENE KNOCKDOWN IN VIVO, AND A MODEL OF THIOACETAMIDE (TAA)-INDUCED LIVER INJURY. THE RESULTS REVEALED THAT TGFBETA1 ENHANCED BRD4 EXPRESSION IN HSCS, WHICH WAS MEDIATED, AT LEAST, BY SMAD3 SIGNALING AND EARLY-IMMEDIATE GENE EGR1 (EARLY GROWTH RESPONSE-1). TGFBETA1-INDUCED SMAD3 SIGNALING INCREASED EGR1 EXPRESSION AND PROMOTED EGR1 BINDING TO BRD4 PROMOTER AT A SITE AROUND -111 BP, PROMOTING BRD4 EXPRESSION. EGR1 KNOCKDOWN REDUCED BRD4 EXPRESSION IN HSCS IN A MOUSE MODEL OF TAA-INDUCED LIVER INJURY AND LESSENED LIVER FIBROSIS. DOUBLE FLUORESCENCE STAINING DEMONSTRATED A STRONG INCREASE IN BRD4 EXPRESSION IN ACTIVATED HSCS IN FIBROTIC AREAS OF THE HUMAN LIVERS, PARALLELING THE UPREGULATION OF P-SMAD3 AND EGR1. THIS RESEARCH SUGGESTED NOVEL MOLECULAR EVENTS UNDERLYING THE ROLES OF THE MASTER PRO-FIBROTIC CYTOKINE TGFBETA1 IN HSC ACTIVATION AND LIVER FIBROGENESIS. 2022 18 5868 35 SUPPRESSIVE EFFECTS OF METFORMIN ON T-HELPER 1-RELATED CHEMOKINES EXPRESSION IN THE HUMAN MONOCYTIC LEUKEMIA CELL LINE THP-1. PURPOSE OF THE STUDY: TYPE 1 AND TYPE 2 DIABETES MELLITUS (DM) ARE CHRONIC T-CELL-MEDIATED INFLAMMATORY DISEASES. METFORMIN IS A WIDELY USED DRUG FOR TYPE 2 DM THAT REDUCES THE NEED FOR INSULIN IN TYPE 1 DM. HOWEVER, WHETHER METFORMIN HAS AN ANTI-INFLAMMATORY EFFECT FOR TREATING DM IS UNKNOWN. WE INVESTIGATED THE ANTI-INFLAMMATORY MECHANISM OF METFORMIN IN THE HUMAN MONOCYTIC LEUKEMIA CELL LINE THP-1. MATERIALS AND METHODS: THE HUMAN MONOCYTIC LEUKEMIA CELL LINE THP-1 WAS PRETREATED WITH METFORMIN AND STIMULATED WITH LIPOPOLYSACCHARIDE (LPS). THE PRODUCTION OF T-HELPER (TH)-1-RELATED CHEMOKINES INCLUDING INTERFERON-GAMMA-INDUCED PROTEIN-10 (IP-10) AND MONOCYTE CHEMOATTRACTANT PROTEIN-1 (MCP-1), TH2-RELATED CHEMOKINE MACROPHAGE-DERIVED CHEMOKINE, AND THE PROINFLAMMATORY CHEMOKINE TUMOR NECROSIS FACTOR-ALPHA WAS MEASURED USING ENZYME-LINKED IMMUNOSORBENT ASSAY. INTRACELLULAR SIGNALING PATHWAYS WERE INVESTIGATED USING WESTERN BLOT ANALYSIS AND CHROMATIN IMMUNOPRECIPITATION ASSAY. RESULTS: METFORMIN SUPPRESSED LPS-INDUCED IP-10 AND MCP-1 PRODUCTION AS WELL AS LPS-INDUCED PHOSPHORYLATION OF C-JUN N-TERMINAL KINASE (JNK), P38, EXTRACELLULAR SIGNAL-REGULATED KINASE (ERK), AND NUCLEAR FACTOR-KAPPA B (NF-KAPPAB). MOREOVER, METFORMIN SUPPRESSED LPS-INDUCED ACETYLATION OF HISTONES H3 AND H4 AT THE IP-10 PROMOTER. CONCLUSIONS: METFORMIN SUPPRESSED THE PRODUCTION OF TH1-RELATED CHEMOKINES IP-10 AND MCP-1 IN THP-1 CELLS. SUPPRESSIVE EFFECTS OF METFORMIN ON IP-10 PRODUCTION MIGHT BE ATTRIBUTED AT LEAST PARTIALLY TO THE JNK, P38, ERK, AND NF-KAPPAB PATHWAYS AS WELL AS TO EPIGENETIC REGULATION THROUGH THE ACETYLATION OF HISTONES H3 AND H4. THESE RESULTS INDICATED THE THERAPEUTIC ANTI-INFLAMMATORY POTENTIAL OF METFORMIN. 2018 19 1632 30 DNMTS ARE INVOLVED IN TGF-BETA1-INDUCED EPITHELIAL-MESENCHYMAL TRANSITIONS IN AIRWAY EPITHELIAL CELLS. CHRONIC RHINOSINUSITIS (CRS) PATHOGENESIS IS CLOSELY RELATED TO TISSUE REMODELING, INCLUDING EPITHELIAL-MESENCHYMAL TRANSITION (EMT). EPIGENETIC MECHANISMS PLAY KEY ROLES IN EMT. DNA METHYLATION, MEDIATED BY DNA METHYLTRANSFERASES (DNMTS), IS AN EPIGENETIC MARKER THAT IS CRITICAL TO EMT. THE GOAL OF THIS STUDY WAS TO DETERMINE WHETHER DNMTS WERE INVOLVED IN TGF-BETA1-INDUCED EMT AND ELUCIDATE THE UNDERLYING MECHANISMS IN NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION AND DNMT ACTIVITY WERE QUANTIFIED. DNMT EXPRESSION WAS MEASURED USING REAL-TIME PCR (QRT-PCR) IN HUMAN CRS TISSUES. MRNA AND PROTEIN LEVELS OF DNMTS, E-CADHERIN, VIMENTIN, ALPHA-SMA, AND FIBRONECTIN WERE DETERMINED USING RT-PCR AND WESTERN BLOTTING, RESPECTIVELY. DNMT1, DNMT3A, AND DNMT3B GENE EXPRESSION WERE KNOCKED DOWN USING SIRNA TRANSFECTION. MAPK PHOSPHORYLATION AND EMT-RELATED TRANSCRIPTION FACTOR LEVELS WERE DETERMINED USING WESTERN BLOTTING. SIGNALING PATHWAYS WERE ANALYZED USING SPECIFIC INHIBITORS OF MAPK. WE DEMONSTRATED THESE DATA IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION, DNMT ACTIVITY, AND DNMT EXPRESSION INCREASED IN CRS TISSUES. DNMT EXPRESSION WAS POSITIVELY CORRELATED WITH LUND-MCKAY CT SCORES. TGF-BETA1 DOSE-DEPENDENTLY INDUCED DNMT EXPRESSION. FURTHER, 5-AZA INHIBITED TGF-BETA1-INDUCED DNMT, SNAIL, AND SLUG EXPRESSION RELATED TO EMT, AS WELL AS P38 AND JNK PHOSPHORYLATION IN A549 CELLS AND TGF-BETA1-INDUCED DNMT EXPRESSION AND EMT IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. TGF-BETA1-INDUCED DNMT EXPRESSION LEADS TO DNA METHYLATION AND EMT VIA P38, JNK, SNAIL, AND SLUG SIGNALING PATHWAYS. INHIBITION OF DNMT SUPPRESSED THE EMT PROCESS AND THEREFORE IS POTENTIALLY A CRS THERAPEUTIC STRATEGY. 2022 20 5995 38 TGFBETA-INDUCED FIBROBLAST ACTIVATION REQUIRES PERSISTENT AND TARGETED HDAC-MEDIATED GENE REPRESSION. TISSUE FIBROSIS IS A CHRONIC DISEASE DRIVEN BY PERSISTENT FIBROBLAST ACTIVATION THAT HAS RECENTLY BEEN LINKED TO EPIGENETIC MODIFICATIONS. HERE, WE SCREENED A SMALL LIBRARY OF EPIGENETIC SMALL-MOLECULE MODULATORS TO IDENTIFY COMPOUNDS CAPABLE OF INHIBITING OR REVERSING TGFBETA-MEDIATED FIBROBLAST ACTIVATION. WE IDENTIFIED PRACINOSTAT, AN HDAC INHIBITOR, AS A POTENT ATTENUATOR OF LUNG FIBROBLAST ACTIVATION AND CONFIRMED ITS EFFICACY IN PATIENT-DERIVED FIBROBLASTS ISOLATED FROM FIBROTIC LUNG TISSUE. MECHANISTICALLY, WE FOUND THAT HDAC-DEPENDENT TRANSCRIPTIONAL REPRESSION WAS AN EARLY AND ESSENTIAL EVENT IN TGFBETA-MEDIATED FIBROBLAST ACTIVATION. TREATMENT OF LUNG FIBROBLASTS WITH PRACINOSTAT BROADLY ATTENUATED TGFBETA-MEDIATED EPIGENETIC REPRESSION AND PROMOTED FIBROBLAST QUIESCENCE. WE CONFIRMED A SPECIFIC ROLE FOR HDAC-DEPENDENT HISTONE DEACETYLATION IN THE PROMOTER REGION OF THE ANTI-FIBROTIC GENE PPARGC1A (PGC1ALPHA) IN RESPONSE TO TGFBETA STIMULATION. FINALLY, WE IDENTIFIED HDAC7 AS A KEY FACTOR WHOSE SIRNA-MEDIATED KNOCKDOWN ATTENUATES FIBROBLAST ACTIVATION WITHOUT ALTERING GLOBAL HISTONE ACETYLATION. TOGETHER, THESE RESULTS PROVIDE NOVEL MECHANISTIC INSIGHT INTO THE ESSENTIAL ROLE HDACS PLAY IN TGFBETA-MEDIATED FIBROBLAST ACTIVATION VIA TARGETED GENE REPRESSION. 2019