1 2784 110 EZH2 PROMOTES EXTRACELLULAR MATRIX DEGRADATION VIA NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) AND P38 SIGNALING PATHWAYS IN PULPITIS. PULPITIS IS A COMPLICATED CHRONIC INFLAMMATORY PROCESS WHICH CAN BE IN A DYNAMIC BALANCE BETWEEN DAMAGE AND REPAIR. THE EXTRACELLULAR MATRIX PLAYS AN IMPORTANT REGULATORY ROLE IN WOUND HEALING AND TISSUE REPAIR. THE AIM OF THIS STUDY WAS TO EXPLORE THE ROLE OF THE EPIGENETIC MARK, ENHANCER OF ZESTE HOMOLOG 2 (EZH2) ON THE DEGRADATION OF EXTRACELLULAR MATRIX DURING PULPITIS. QUANTITATIVE POLYMERASE CHAIN REACTION WAS USED TO ASSESS THE EXPRESSION OF MATRIX METALLOPROTEINASES (MMPS) AND TYPE I COLLAGEN IN HUMAN DENTAL PULP CELLS (HDPCS) UPON EZH2 AND EI1 (EZH2 INHIBITOR) STIMULATION. THE MECHANISM OF EZH2 AFFECTING EXTRACELLULAR MATRIX WAS EXPLORED THROUGH QUANTITATIVE POLYMERASE CHAIN REACTION AND WESTERN BLOT. A RAT MODEL OF DENTAL PULP INFLAMMATION WAS ESTABLISHED, AND THE EXPRESSION OF TYPE I COLLAGEN IN DENTAL PULP UNDER EZH2 STIMULATION WAS DETECTED BY IMMUNOHISTOCHEMICAL STAINING. EZH2 UPREGULATED THE EXPRESSION OF MMP-1, MMP-3, MMP-8, AND MMP-10 AND DECREASED THE PRODUCTION OF TYPE I COLLAGEN IN HDPCS, WHILE EI1 HAD THE OPPOSITE EFFECT. EZH2 ACTIVATED THE NUCLEAR FACTOR-KAPPA B (NF-KAPPAB) AND P38 SIGNALING PATHWAYS IN HDPCS, THE INHIBITION OF WHICH REVERSED THE INDUCTION OF MMPS AND THE SUPPRESSION OF TYPE I COLLAGEN. EZH2 CAN DOWNREGULATE THE TYPE I COLLAGEN LEVELS IN AN EXPERIMENTAL MODEL OF DENTAL PULPITIS IN RATS. EZH2 PROMOTES EXTRACELLULAR MATRIX DEGRADATION VIA NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) AND P38 SIGNALING PATHWAYS IN PULPITIS. EZH2 CAN DECREASE THE TYPE I COLLAGEN LEVELS IN VIVO AND IN VITRO. 2021 2 4159 32 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 3 1905 42 ENHANCER OF ZESTE HOMOLOG 2 CONTRIBUTES TO APOPTOSIS BY INACTIVATING JANUS KINASE 2/ SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION SIGNALING IN INFLAMMATORY BOWEL DISEASE. BACKGROUND: INFLAMMATORY BOWEL DISEASE (IBD) IS A PREVALENT WORLDWIDE HEALTH PROBLEM FEATURED BY RELAPSING, CHRONIC GASTROINTESTINAL INFLAMMATION. ENHANCER OF ZESTE HOMOLOG 2 (EZH2) IS A CRITICAL EPIGENETIC REGULATOR IN DIFFERENT PATHOLOGICAL MODELS, SUCH AS CANCER AND INFLAMMATION. HOWEVER, THE ROLE OF EZH2 IN THE IBD DEVELOPMENT IS STILL OBSCURE. AIM: TO EXPLORE THE EFFECT OF EZH2 ON IBD PROGRESSION AND THE UNDERLYING MECHANISM. METHODS: THE IBD MOUSE MODEL WAS CONDUCTED BY ADDING DEXTRAN SODIUM SULFATE (DSS), AND THE EFFECT OF EZH2 ON DSS-INDUCED COLITIS WAS ASSESSED IN THE MODEL. THE FUNCTION OF EZH2 IN REGULATING APOPTOSIS AND PERMEABILITY WAS EVALUATED BY ANNEXIN V-FITC APOPTOSIS DETECTION KIT, TRANSEPITHELIAL ELECTRICAL RESISTANCE ANALYSIS, AND WESTERN BLOT ANALYSIS OF RELATED MARKERS, INCLUDING ZONA OCCLUDENS 1, CLAUDIN-5, AND OCCLUDIN, IN NCM460 AND FETAL HUMAN COLON (FHC) CELLS. THE MECHANICAL INVESTIGATION WAS PERFORMED BY QUANTITATIVE REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION, WESTERN BLOT ANALYSIS, AND CHROMATIN IMMUNOPRECIPITATION ASSAYS. RESULTS: THE COLON LENGTH WAS INHIBITED IN THE DSS-TREATED MICE AND WAS ENHANCED BY THE EZH2 DEPLETION IN THE SYSTEM. DSS TREATMENT CAUSED A DECREASED HISTOLOGICAL SCORE IN THE MICE, WHICH WAS REVERSED BY EZH2 DEPLETION. THE INFLAMMATORY CYTOKINES, SUCH AS TUMOR NECROSIS FACTOR-ALPHA, INTERLEUKIN-6, AND INTERLEUKIN-1BETA, WERE INDUCED IN THE DSS-TREATED MICE, IN WHICH THE DEPLETION OF EZH2 COULD REVERSE THIS EFFECT. MOREOVER, THE TUMOR NECROSIS FACTOR-ALPHA TREATMENT INDUCED THE APOPTOSIS OF NCM460 AND FHC CELLS, IN WHICH EZH2 DEPLETION COULD REVERSE THIS EFFECT IN THE CELLS. MOREOVER, THE DEPLETION OF EZH2 ATTENUATED PERMEABILITY OF COLONIC EPITHELIAL CELLS. MECHANICALLY, THE DEPLETION OF EZH2 OR EZH2 INHIBITOR GSK343 WAS ABLE TO ENHANCE THE EXPRESSION AND THE PHOSPHORYLATION OF JANUS KINASE 2 (JK2) AND SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION IN THE NCM460 AND FHC CELLS. SPECIFICALLY, EZH2 INACTIVATED JAK2 EXPRESSION BY REGULATING HISTONE H3K27ME3. JAK2 INHIBITOR TG101348 WAS ABLE TO REVERSE EZH2 KNOCKDOWN-MEDIATED COLONIC EPITHELIAL CELL PERMEABILITY AND APOPTOSIS. CONCLUSION: THUS, WE CONCLUDED THAT EZH2 CONTRIBUTED TO APOPTOSIS AND INFLAMMATORY RESPONSE BY INACTIVATING JAK2/ SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION SIGNALING IN IBD. EZH2 MAY BE APPLIED AS A POTENTIAL TARGET FOR IBD THERAPY. 2021 4 3527 29 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 5 2748 32 EXPRESSION AND FUNCTION OF EZH2 IN SYNOVIAL FIBROBLASTS: EPIGENETIC REPRESSION OF THE WNT INHIBITOR SFRP1 IN RHEUMATOID ARTHRITIS. OBJECTIVES: TO STUDY THE EXPRESSION, REGULATION AND FUNCTION OF THE HISTONE METHYLTRANSFERASE ENHANCER OF ZESTE HOMOLOGUE 2 (EZH2) IN SYNOVIAL FIBROBLASTS (SF) FROM PATIENTS WITH RHEUMATOID ARTHRITIS (RA) AND OSTEOARTHRITIS (OA). METHODS: SF WERE OBTAINED FROM RA AND OA PATIENTS UNDERGOING JOINT SURGERY. EXPRESSION LEVELS WERE ASSESSED BY QUANTITATIVE REAL-TIME PCR AND WESTERN BLOT. KINASE INHIBITORS AND REPORTER GENE ASSAYS WERE EMPLOYED TO STUDY SIGNALLING PATHWAYS. FUNCTIONAL ANALYSES INCLUDED EZH2 OVEREXPRESSION BY PLASMID TRANSFECTION AND GENE SILENCING BY SMALL INTERFERING RNA. CHROMATIN IMMUNOPRECIPITATION ASSAY WAS USED TO ANALYSE HISTONE METHYLATION WITHIN DISTINCT PROMOTER REGIONS. RESULTS: BY STUDYING THE EXPRESSION AND FUNCTION OF EZH2 IN SF THE AUTHORS FOUND THAT EZH2 IS OVEREXPRESSED IN RHEUMATOID ARTHRITIS SYNOVIAL FIBROBLASTS (RASF) AND FURTHER INDUCED BY TUMOUR NECROSIS FACTOR ALPHA THROUGH THE NUCLEAR FACTOR KAPPA B AND JUN KINASE PATHWAYS. AS A TARGET GENE OF EZH2 THE AUTHORS IDENTIFIED SECRETED FRIZZLED-RELATED PROTEIN 1 (SFRP1), AN INHIBITOR OF WNT SIGNALLING, WHICH IS ASSOCIATED WITH THE ACTIVATION OF RASF, AND SHOW THAT SFRP1 EXPRESSION CORRELATES WITH THE OCCUPATION OF ITS PROMOTER WITH ACTIVATING AND SILENCING HISTONE MARKS. CONCLUSIONS: THESE DATA STRONGLY SUGGEST THAT THE CHRONIC INFLAMMATORY ENVIRONMENT OF THE RA JOINT INDUCES EZH2 AND THUS MIGHT CAUSE CHANGES IN THE EPIGENETIC PROGRAMMES OF SF. 2011 6 2825 39 FLOW-DEPENDENT EPIGENETIC REGULATION OF IGFBP5 EXPRESSION BY H3K27ME3 CONTRIBUTES TO ENDOTHELIAL ANTI-INFLAMMATORY EFFECTS. RATIONALE: ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY AND EPIGENETIC DISEASE THAT IS INFLUENCED BY DIFFERENT PATTERNS OF BLOOD FLOW. HOWEVER, THE EPIGENETIC MECHANISM WHEREBY ATHEROPROTECTIVE FLOW CONTROLS ENDOTHELIAL GENE PROGRAMMING REMAINS ELUSIVE. HERE, WE INVESTIGATED THE POSSIBILITY THAT FLOW ALTERS ENDOTHELIAL GENE EXPRESSION THROUGH EPIGENETIC MECHANISMS. METHODS: EN FACE STAINING AND WESTERN BLOT WERE USED TO DETECT PROTEIN EXPRESSION. REAL-TIME PCR WAS USED TO DETERMINE RELATIVE GENE EXPRESSION. RNA-SEQUENCING OF HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS TREATED WITH SIRNA OF ENHANCER OF ZESTE HOMOLOG 2 (EZH2) OR LAMINAR FLOW WAS USED FOR TRANSCRIPTIONAL PROFILING. RESULTS: WE FOUND THAT TRIMETHYLATION OF HISTONE 3 LYSINE 27 (H3K27ME3), A REPRESSIVE EPIGENETIC MARK THAT ORCHESTRATES GENE REPRESSION, WAS REDUCED IN LAMINAR FLOW AREAS OF MOUSE AORTA AND FLOW-TREATED HUMAN ENDOTHELIAL CELLS. THE DECREASE OF H3K27ME3 PARALLELED A REDUCTION IN THE EPIGENETIC "WRITER"-EZH2, THE CATALYTIC SUBUNIT OF THE POLYCOMB REPRESSIVE COMPLEX 2 (PRC2). MOREOVER, LAMINAR FLOW DECREASED EXPRESSION OF EZH2 VIA MECHANOSENSITIVE MIR101. GENOME-WIDE TRANSCRIPTOME PROFILING STUDIES IN ENDOTHELIAL CELLS TREATED WITH EZH2 SIRNA AND FLOW REVEALED THE UPREGULATION OF NOVEL MECHANOSENSITIVE GENE IGFBP5 (INSULIN-LIKE GROWTH FACTOR-BINDING PROTEIN 5), WHICH IS EPIGENETICALLY SILENCED BY H3K27ME3. FUNCTIONALLY, INHIBITION OF H3K27ME3 BY EZH2 SIRNA OR GSK126 (A SPECIFIC EZH2 INHIBITOR) REDUCED H3K27ME3 LEVELS AND MONOCYTE ADHESION TO ENDOTHELIAL CELLS. ADENOVIRAL OVEREXPRESSION OF IGFBP5 ALSO RECAPITULATED THE ANTI-INFLAMMATORY EFFECTS OF H3K27ME3 INHIBITION. MORE IMPORTANTLY, WE OBSERVED EZH2 UPREGULATION, AND IGFBP5 DOWNREGULATION, IN ADVANCED ATHEROSCLEROTIC PLAQUES FROM HUMAN PATIENTS. CONCLUSION: TAKEN TOGETHER, OUR FINDINGS REVEAL THAT ATHEROPROTECTIVE FLOW REDUCES H3K27ME3 AS A CHROMATIN-BASED MECHANISM TO AUGMENT THE EXPRESSION OF GENES THAT CONFER AN ANTI-INFLAMMATORY RESPONSE IN THE ENDOTHELIUM. OUR STUDY EXEMPLIFIES FLOW-DEPENDENT EPIGENETIC REGULATION OF ENDOTHELIAL GENE EXPRESSION, AND ALSO SUGGESTS THAT TARGETING THE EZH2/H3K27ME3/IGFBP5 PATHWAY MAY OFFER NOVEL THERAPEUTICS FOR INFLAMMATORY DISORDERS SUCH AS ATHEROSCLEROSIS. 2018 7 2783 30 EZH2 METHYLTRANSFERASE REGULATES NEUROINFLAMMATION AND NEUROPATHIC PAIN. RECENT STUDIES BY US AND OTHERS HAVE SHOWN THAT ENHANCER OF ZESTE HOMOLOG-2 (EZH2), A HISTONE METHYLTRANSFERASE, IN GLIAL CELLS REGULATES THE GENESIS OF NEUROPATHIC PAIN BY MODULATING THE PRODUCTION OF PROINFLAMMATORY CYTOKINES AND CHEMOKINES. IN THIS REVIEW, WE SUMMARIZE RECENT ADVANCES IN THIS RESEARCH AREA. EZH2 IS A SUBUNIT OF POLYCOMB REPRESSIVE COMPLEX 2 (PRC2), WHICH PRIMARILY SERVES AS A HISTONE METHYLTRANSFERASE TO CATALYZE METHYLATION OF HISTONE 3 ON LYSINE 27 (H3K27), ULTIMATELY RESULTING IN TRANSCRIPTIONAL REPRESSION. ANIMALS WITH NEUROPATHIC PAIN EXHIBIT INCREASED EZH2 ACTIVITY AND NEUROINFLAMMATION OF THE INJURED NERVE, SPINAL CORD, AND ANTERIOR CINGULATE CORTEX. INHIBITION OF EZH2 WITH DZNEP OR GSK-126 AMELIORATES NEUROINFLAMMATION AND NEUROPATHIC PAIN. EZH2 PROTEIN EXPRESSION INCREASES UPON ACTIVATION OF TOLL-LIKE RECEPTOR 4 AND CALCITONIN GENE-RELATED PEPTIDE RECEPTORS, DOWNREGULATION OF MIR-124-3P AND MIR-378 MICRORNAS, OR UPREGULATION OF LNCENC1 AND MALAT1 LONG NONCODING RNAS. GENES SUPPRESSED BY EZH2 INCLUDE SUPPRESSOR OF CYTOKINE SIGNALING 3 (SOCS3), NUCLEAR FACTOR (ERYTHROID-DERIVED 2)-LIKE-2 FACTOR (NRF2), MIR-29B-3P, MIR-146A-5P, AND BRAIN-SPECIFIC ANGIOGENESIS INHIBITOR 1 (BAI1). PRO-INFLAMMATORY MEDIATORS FACILITATE NEURONAL ACTIVATION ALONG PAIN-SIGNALING PATHWAYS BY SENSITIZING NOCICEPTORS IN THE PERIPHERY, AS WELL AS ENHANCING EXCITATORY SYNAPTIC ACTIVITIES AND SUPPRESSING INHIBITORY SYNAPTIC ACTIVITIES IN THE CNS. THESE STUDIES COLLECTIVELY REVEAL THAT EZH2 IS IMPLICATED IN SIGNALING PATHWAYS KNOWN TO BE KEY PLAYERS IN THE PROCESS OF NEUROINFLAMMATION AND GENESIS OF NEUROPATHIC PAIN. THEREFORE, TARGETING THE EZH2 SIGNALING PATHWAY MAY OPEN A NEW AVENUE TO MITIGATE NEUROINFLAMMATION AND NEUROPATHIC PAIN. 2023 8 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 9 3944 31 LNCRNA H19-EZH2 INTERACTION PROMOTES LIVER FIBROSIS VIA REPROGRAMMING H3K27ME3 PROFILES. LIVER FIBROSIS IS A WOUND-HEALING PROCESS CHARACTERIZED BY EXCESS FORMATION OF EXTRACELLULAR MATRIX (ECM) FROM ACTIVATED HEPATIC STELLATE CELLS (HSCS). PREVIOUS STUDIES SHOW THAT BOTH EZH2, AN EPIGENETIC REGULATOR THAT CATALYZES LYSINE 27 TRIMETHYLATION ON HISTONE 3 (H3K27ME3), AND LONG NON-CODING RNA H19 ARE HIGHLY CORRELATED WITH FIBROGENESIS. IN THE CURRENT STUDY, WE INVESTIGATED THE UNDERLYING MECHANISMS. VARIOUS MODELS OF LIVER FIBROSIS INCLUDING MDR2(-/-), BILE DUCT LIGATION (BDL) AND CCL(4) MICE WERE ADAPTED. WE FOUND THAT EZH2 WAS MARKEDLY UPREGULATED AND CORRELATED WITH H19 AND FIBROTIC MARKERS EXPRESSION IN THESE MODELS. ADMINISTRATION OF EZH2 INHIBITOR 3-DZNEP CAUSED SIGNIFICANT PROTECTIVE EFFECTS IN THESE MODELS. FURTHERMORE, TREATMENT WITH 3-DZNEP OR GSK126 SIGNIFICANTLY INHIBITED PRIMARY HSC ACTIVATION AND PROLIFERATION IN TGF-BETA-TREATED HSCS AND H19-OVEREXPREESING LX2 CELLS IN VIVO. USING RNA-PULL DOWN ASSAY COMBINED WITH RNA IMMUNOPRECIPITATION, WE DEMONSTRATED THAT H19 COULD DIRECTLY BIND TO EZH2. INTEGRATED ANALYSIS OF RNA-SEQUENCING (RNA-SEQ) AND CHROMATIN IMMUNOPRECIPITATION SEQUENCING (CHIP-SEQ) FURTHER REVEALED THAT H19 REGULATED THE REPROGRAMMING OF EZH2-MEDIATED H3K27ME3 PROFILES, WHICH EPIGENETICALLY PROMOTED SEVERAL PATHWAYS FAVORING HSCS ACTIVATION AND PROLIFERATION, INCLUDING EPITHELIAL-MESENCHYMAL TRANSITION AND WNT/BETA-CATENIN SIGNALING. IN CONCLUSION, HIGHLY EXPRESSED H19 IN CHRONIC LIVER DISEASES PROMOTES FIBROGENESIS BY REPROGRAMMING EZH2-MEDIATED EPIGENETIC REGULATION OF HSCS ACTIVATION. TARGETING THE H19-EZH2 INTERACTION MAY SERVE AS A NOVEL THERAPEUTIC APPROACH FOR LIVER FIBROSIS. 2023 10 3795 30 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 5088 32 PIPERLONGUMINE REGULATES EPIGENETIC MODULATION AND ALLEVIATES PSORIASIS-LIKE SKIN INFLAMMATION VIA INHIBITION OF HYPERPROLIFERATION AND INFLAMMATION. PSORIASIS IS AN AUTOIMMUNE SKIN DISEASE, WHERE CHRONIC IMMUNE RESPONSES DUE TO EXAGGERATED CYTOKINE SIGNALING, ABNORMAL DIFFERENTIATION, AND EVASION OF KERATINOCYTES APOPTOSIS PLAYS A CRUCIAL ROLE IN MEDIATING ABNORMAL KERATINOCYTES HYPERPROLIFERATION. FROM THE THERAPEUTIC PERSPECTIVE, THE MOLECULES WITH STRONG ANTI-PROLIFERATIVE AND ANTI-INFLAMMATORY PROPERTIES COULD HAVE TREMENDOUS RELEVANCE. IN THIS STUDY, WE DEMONSTRATED THAT PIPERLONGUMINE (PPL) TREATMENT EFFECTIVELY ABROGATED THE HYPERPROLIFERATION AND DIFFERENTIATION OF KERATINOCYTES BY INDUCING ROS-MEDIATED LATE APOPTOSIS WITH LOSS OF MITOCHONDRIAL MEMBRANE POTENTIAL. BESIDES, THE ARREST OF CELL CYCLE WAS FOUND AT SUB-G1 PHASE AS A RESULT OF DNA FRAGMENTATION. MOLECULARLY, INHIBITION OF STAT3 AND AKT SIGNALING WAS OBSERVED WITH A DECREASE IN PROLIFERATIVE MARKERS SUCH AS PCNA, KI67, AND CYCLIN D1 ALONG WITH ANTI-APOPTOTIC BCL-2 PROTEIN EXPRESSION. KERATIN 17 IS A CRITICAL REGULATOR OF KERATINOCYTE DIFFERENTIATION, AND IT WAS FOUND TO BE DOWNREGULATED WITH PPL SIGNIFICANTLY. FURTHERMORE, PROMINENT ANTI-INFLAMMATORY EFFECTS WERE OBSERVED BY INHIBITION OF LIPOPOLYSACCHARIDE (LPS)/IMIQUIMOD (IMQ)-INDUCED P65 NF-KAPPAB SIGNALING CASCADE AND STRONGLY INHIBITED THE PRODUCTION OF CYTOKINE STORM INVOLVED IN PSORIASIS-LIKE SKIN INFLAMMATION, THUS LED TO THE RESTORATION OF NORMAL EPIDERMAL ARCHITECTURE WITH REDUCTION OF EPIDERMAL HYPERPLASIA AND SPLENOMEGALY. IN ADDITION, PPL EPIGENETICALLY INHIBITED HISTONE-MODIFYING ENZYMES, WHICH INCLUDE HISTONE DEACETYLASES (HDACS) OF CLASS I (HDAC1-4) AND CLASS II (HDAC6) EVALUATED BY IMMUNOBLOTTING AND HDAC ENZYME ASSAY KIT. IN ADDITION, OUR RESULTS SHOW THAT PPL EFFECTIVELY INHIBITS THE NUCLEAR TRANSLOCATION OF P65 AND A HISTONE MODULATOR HDAC3, THUS SEQUESTERED IN THE CYTOPLASM OF MACROPHAGES. FURTHERMORE, PPL EFFECTIVELY ENHANCED THE PROTEIN-PROTEIN INTERACTIONS OF HDAC3 AND P65 WITH IKAPPABALPHA, WHICH WAS DISRUPTED BY LPS STIMULATION AND WERE EVALUATED BY CO-IP AND MOLECULAR MODELING. COLLECTIVELY, OUR FINDINGS INDICATE THAT PIPERLONGUMINE MAY SERVE AS AN ANTI-PROLIFERATIVE AND ANTI-INFLAMMATORY AGENT AND COULD SERVE AS A POTENTIAL THERAPEUTIC OPTION IN TREATING PSORIASIS. 2020 12 172 30 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 13 273 35 AGE-INDUCED SUPPRESSION OF EZH2 MEDIATES INJURY OF PODOCYTES BY REDUCING H3K27ME3. BACKGROUND: CHRONIC HYPERGLYCEMIA, A PIVOTAL FEATURE OF DIABETES MELLITUS (DM), INITIATES THE FORMATION OF ADVANCED GLYCATION END PRODUCTS (AGES) AND THE DYSREGULATION OF EPIGENETIC MECHANISMS, WHICH MAY CAUSE INJURY TO RENAL PODOCYTES, A CENTRAL FEATURE OF DIABETIC KIDNEY DISEASE (DKD). PREVIOUS DATA OF OUR GROUP SHOWED THAT AGES SIGNIFICANTLY REDUCE THE EXPRESSION OF NIPP1 (NUCLEAR INHIBITOR OF PROTEIN PHOSPHATASE 1) IN PODOCYTES IN VITRO AS WELL AS IN HUMAN AND MURINE DKD. NIPP1 WAS SHOWN BY OTHERS TO INTERACT WITH ENHANCER OF ZESTE HOMOLOG 2 (EZH2), WHICH CATALYZES THE REPRESSIVE METHYLATION OF H3K27ME3 ON HISTONE 3. THEREFORE, WE HYPOTHESIZED THAT AGES CAN DIRECTLY INDUCE EPIGENETIC CHANGES IN PODOCYTES. METHODS: WE ANALYZED THE RELEVANCE OF AGES ON EZH2 EXPRESSION AND ACTIVITY IN A MURINE PODOCYTE CELL LINE. CELLS WERE TREATED WITH 5 MG/ML GLYCATED BSA FOR 24 H. TO DETERMINE THE MEANING OF EZH2 SUPPRESSION, EZH2 ACTIVITY WAS INHIBITED BY INCUBATING THE CELLS WITH THE PHARMACOLOGICAL METHYLTRANSFERASE INHIBITOR 3-DEAZANEPLANOCIN A; EZH2 EXPRESSION WAS REPRESSED WITH SIRNA. MRNA EXPRESSION WAS ANALYZED WITH REAL-TIME PCR, AND PROTEIN EXPRESSION WITH WESTERN BLOT. EZH2 EXPRESSION AND LEVEL OF H3K27 TRIMETHYLATION IN PODOCYTES OF DIABETIC DB/DB MICE, A MOUSE MODEL FOR TYPE 2 DM, WERE ANALYZED USING IMMUNOFLUORESCENCE. RESULTS: OUR DATA DEMONSTRATED THAT AGES DECREASE EZH2 EXPRESSION IN PODOCYTES AND CONSEQUENTLY REDUCE H3K27ME3. THIS SUPPRESSION OF EZH2 MIMICKED THE AGE EFFECTS AND CAUSED AN UPREGULATED EXPRESSION OF PATHOLOGICAL FACTORS THAT CONTRIBUTE TO PODOCYTE INJURY IN DKD. IN ADDITION, ANALYSES OF DB/DB MICE SHOWED SIGNIFICANTLY REDUCED H3K27ME3 AND EZH2 EXPRESSION IN PODOCYTES. MOREOVER, THE SUPPRESSION OF NIPP1 AND EZH2 SHOWED SIMILAR EFFECTS REGARDING PODOCYTE INJURY. CONCLUSIONS: OUR STUDIES PROVIDE A NOVEL PATHWAY HOW AGES CONTRIBUTE TO PODOCYTE INJURY AND THE FORMATION OF THE SO-CALLED METABOLIC MEMORY IN DKD. 2020 14 5972 24 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 15 5114 31 PORPHYROMONAS GINGIVALIS LIPOPOLYSACCHARIDE STIMULATION IN HUMAN PERIODONTAL LIGAMENT STEM CELLS: ROLE OF EPIGENETIC MODIFICATIONS TO THE INFLAMMATION. PERIODONTITIS IS A CHRONIC ORAL INFLAMMATORY DISEASE PRODUCED BY BACTERIA. GINGIVAL RETRACTION AND BONE AND CONNECTIVE TISSUES RESORPTION ARE THE HALLMARKS OF THIS DISEASE. CHRONIC PERIODONTITIS MAY CONTRIBUTE TO THE RISK OF ONSET OR PROGRESSION OF NEUROINFLAMMATORY PATHOLOGICAL CONDITIONS, SUCH AS ALZHEIMER'S DISEASE. THE MAIN GOAL OF THE PRESENT STUDY WAS TO INVESTIGATE IF THE ROLE OF EPIGENETIC MODULATIONS IS INVOLVED IN PERIODONTITIS USING HUMAN PERIODONTAL LIGAMENT STEM CELLS (HPDLSCS) AS AN IN VITRO MODEL SYSTEM. HPDLSCS WERE TREATED WITH LIPOPOLYSACCHARIDE OF PORPHYROMONAS GINGIVALIS AND THE EXPRESSION OF PROTEINS ASSOCIATED WITH DNA METHYLATION AND HISTONE ACETYLATION, SUCH AS DNMT1 AND P300, RESPECTIVELY, AND INFLAMMATORY TRANSCRIPTION FACTOR NF-KB, WERE EXAMINED. IMMUNOFLUORESCENCE, WESTERN BLOT AND NEXT GENERATION SEQUENCING RESULTS DEMONSTRATED THAT P. GINGIVALIS LIPOPOLYSACCHARIDE SIGNIFICANTLY REDUCED DNA METHYLASE DNMT1, WHILE IT MARKEDLY UPREGULATED THE LEVEL OF HISTONE ACETYLTRANSFERASE P300 AND NF-KB IN HPDLSCS. OUR RESULTS SHOWED THAT P. GINGIVALIS LIPOPOLYSACCHARIDE MARKEDLY REGULATE THE GENES INVOLVED IN EPIGENETIC MECHANISM, WHICH MAY RESULT IN INFLAMMATION INDUCTION. WE PROPOSE THAT P. GINGIVALIS LIPOPOLYSACCHARIDE-TREATED HPDLSCS COULD BE A POTENTIAL IN VITRO MODEL SYSTEM TO STUDY EPIGENETICS MODULATIONS ASSOCIATED WITH PERIODONTITIS, WHICH MIGHT BE HELPFUL TO IDENTIFY NOVEL BIOMARKERS LINKED TO THIS ORAL INFLAMMATORY DISEASE. 2017 16 4302 33 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 17 5795 31 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 18 2247 19 EPIGENETIC MODULATION OF MACROPHAGE POLARIZATION PREVENTS LUMBAR DISC DEGENERATION. INFLAMMATION PLAYS AN ESSENTIAL ROLE IN THE DEVELOPMENT OF LUMBAR DISC DEGENERATION (LDD), ALTHOUGH THE EXACT EFFECTS OF MACROPHAGE SUBTYPES ON LDD REMAIN UNCLEAR. BASED ON PREVIOUS STUDIES, WE HYPOTHESIZED THAT M2-POLARIZATION OF LOCAL MACROPHAGES AND SIMULTANEOUS SUPPRESSION OF THEIR PRODUCTION OF FIBROTIC TRANSFORMING GROWTH FACTOR BETA 1 (TGFBETA1) COULD INHIBIT PROGRESSION OF LDD. THUS, WE APPLIED AN ORTHOTOPIC INJECTION OF ADENO-ASSOCIATED VIRUS (AAV) CARRYING SHRNA FOR DNA METHYLTRANSFERASE 1 (DNMT1) AND/OR SHRNA FOR TGFBETA1 UNDER A MACROPHAGE-SPECIFIC CD68 PROMOTER TO SPECIFICALLY TARGET LOCAL MACROPHAGES IN A MOUSE MODEL FOR LDD. WE FOUND THAT SHDNMT1 SIGNIFICANTLY REDUCED LEVELS OF THE PRO-INFLAMMATORY CYTOKINES TNFALPHA, IL-1BETA AND IL-6, SIGNIFICANTLY INCREASED LEVELS OF THE ANTI-INFLAMMATORY CYTOKINES IL-4 AND IL-10, SIGNIFICANTLY INCREASED M2 MACROPHAGE POLARIZATION, SIGNIFICANTLY REDUCED CELL APOPTOSIS IN THE DISC DEGENERATION ZONE AND SIGNIFICANTLY REDUCED LDD-ASSOCIATED PAIN. THE ANTI-APOPTOTIC AND ANTI-PAIN EFFECTS WERE FURTHER STRENGTHENED BY CO-APPLICATION OF SHTGFBETA1. TOGETHER, THESE DATA SUGGEST THAT M2 POLARIZATION OF MACROPHAGES INDUCED BY BOTH EPIGENETIC MODULATION AND SUPPRESSED PRODUCTION AND RELEASE OF TGFBETA1 FROM POLARIZED M2 MACROPHAGES, MAY HAVE A DEMONSTRABLE THERAPEUTIC EFFECT ON LDD. 2020 19 5920 29 TARGETING CHROMATIN REMODELING IN INFLAMMATION AND FIBROSIS. MUCOSAL SURFACES OF THE HUMAN BODY ARE LINED BY A CONTIGUOUS EPITHELIAL CELL SURFACE THAT FORMS A BARRIER TO AEROSOLIZED PATHOGENS. SPECIALIZED PATTERN RECOGNITION RECEPTORS DETECT THE PRESENCE OF VIRAL PATHOGENS AND INITIATE PROTECTIVE HOST RESPONSES BY TRIGGERING ACTIVATION OF THE NUCLEAR FACTOR KAPPAB (NFKAPPAB)/RELA TRANSCRIPTION FACTOR AND FORMATION OF A COMPLEX WITH THE POSITIVE TRANSCRIPTION ELONGATION FACTOR (P-TEFB)/CYCLIN-DEPENDENT KINASE (CDK)9 AND BROMODOMAIN-CONTAINING PROTEIN 4 (BRD4) EPIGENETIC READER. THE RELA.BRD4.P-TEFB COMPLEX PRODUCES ACUTE INFLAMMATION BY REGULATING TRANSCRIPTIONAL ELONGATION, WHICH PRODUCES A RAPID GENOMIC RESPONSE BY INACTIVE GENES MAINTAINED IN AN OPEN CHROMATIN CONFIGURATION ENGAGED WITH HYPOPHOSPHORYLATED RNA POLYMERASE II. WE DESCRIBE RECENT STUDIES THAT HAVE LINKED PROLONGED ACTIVATION OF THE RELA-BRD4 PATHWAY WITH THE EPITHELIAL-MESENCHYMAL TRANSITION (EMT) BY INDUCING A CORE OF EMT COREPRESSORS, STIMULATING SECRETION OF GROWTH FACTORS PROMOTING AIRWAY FIBROSIS. THE MESENCHYMAL STATE PRODUCES REWIRING OF THE KINOME AND REPROGRAMMING OF INNATE RESPONSES TOWARD INFLAMMATION. IN ADDITION, THE CORE REGULATOR ZINC FINGER E-BOX HOMEODOMAIN 1 (ZEB1) SILENCES THE EXPRESSION OF THE INTERFERON RESPONSE FACTOR 1 (IRF1), REQUIRED FOR TYPE III IFN EXPRESSION. THIS EPIGENETIC SILENCING IS MEDIATED BY THE ENHANCER OF ZESTE 2 (EZH2) HISTONE METHYLTRANSFERASE. BECAUSE OF THEIR POTENTIAL APPLICATIONS IN CANCER AND INFLAMMATION, SMALL-MOLECULE INHIBITORS OF NFKAPPAB/RELA, CDK9, BRD4, AND EZH2 HAVE BEEN THE TARGETS OF MEDICINAL CHEMISTRY EFFORTS. WE SUGGEST THAT DISRUPTION OF THE RELA.BRD4.P-TEFB PATHWAY AND EZH2 METHYLTRANSFERASE HAS IMPORTANT IMPLICATIONS FOR REVERSING FIBROSIS AND RESTORING NORMAL MUCOSAL IMMUNITY IN CHRONIC INFLAMMATORY DISEASES. 2017 20 141 24 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