1 4159 130 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 2 3944 43 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 3 164 29 ABNORMAL HISTONE METHYLATION IS RESPONSIBLE FOR INCREASED VASCULAR ENDOTHELIAL GROWTH FACTOR 165A SECRETION FROM AIRWAY SMOOTH MUSCLE CELLS IN ASTHMA. VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF), A KEY ANGIOGENIC MOLECULE, IS ABERRANTLY EXPRESSED IN SEVERAL DISEASES INCLUDING ASTHMA WHERE IT CONTRIBUTES TO BRONCHIAL VASCULAR REMODELING AND CHRONIC INFLAMMATION. ASTHMATIC HUMAN AIRWAY SMOOTH MUSCLE CELLS HYPERSECRETE VEGF, BUT THE MECHANISM IS UNCLEAR. IN THIS STUDY, WE DEFINED THE MECHANISM IN HUMAN AIRWAY SMOOTH MUSCLE CELLS FROM NONASTHMATIC AND ASTHMATIC PATIENTS. WE FOUND THAT ASTHMATIC CELLS LACKED A REPRESSION COMPLEX AT THE VEGF PROMOTER, WHICH WAS PRESENT IN NONASTHMATIC CELLS. RECRUITMENT OF G9A, TRIMETHYLATION OF HISTONE H3 AT LYSINE 9 (H3K9ME3), AND A RESULTANT DECREASE IN RNA POLYMERASE II AT THE VEGF PROMOTER WAS CRITICAL TO REPRESSION OF VEGF SECRETION IN NONASTHMATIC CELLS. AT THE ASTHMATIC PROMOTER, H3K9ME3 WAS ABSENT BECAUSE OF FAILED RECRUITMENT OF G9A; RNA POLYMERASE II BINDING, IN ASSOCIATION WITH TATA-BINDING PROTEIN-ASSOCIATED FACTOR 1, WAS INCREASED; H3K4ME3 WAS PRESENT; AND SP1 BINDING WAS EXAGGERATED AND SUSTAINED. IN CONTRAST, DNA METHYLATION AND HISTONE ACETYLATION WERE SIMILAR IN ASTHMATIC AND NONASTHMATIC CELLS. THIS IS THE FIRST STUDY, TO OUR KNOWLEDGE, TO SHOW THAT AIRWAY CELLS IN ASTHMA HAVE ALTERED EPIGENETIC REGULATION OF REMODELING GENE(S). HISTONE METHYLATION AT GENES SUCH AS VEGF MAY BE AN IMPORTANT NEW THERAPEUTIC TARGET. 2012 4 1615 33 DNA METHYLTRANSFERASE 3B PLAYS A PROTECTIVE ROLE AGAINST HEPATOCARCINOGENESIS CAUSED BY CHRONIC INFLAMMATION VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. MOST HEPATOCELLULAR CARCINOMAS (HCCS) DEVELOP ON THE BASIS OF CHRONIC HEPATITIS, BUT THE MECHANISM OF EPIGENETIC REGULATION IN INFLAMMATORY HEPATOCARCINOGENESIS HAS YET TO BE ELUCIDATED. AMONG DE NOVO DNA METHYLTRANSFERASES (DNMTS), DNMT3B HAS LATELY BEEN REPORTED TO ACT SPECIFICALLY ON ACTIVELY TRANSCRIBED GENES, SUGGESTING THE POSSIBILITY THAT IT PLAYS A ROLE IN THE PATHOGENESIS OF CANCER. WE CONFIRMED THAT DNMT3B ISOFORMS LACKING ITS CATALYTIC DOMAIN WERE HIGHLY EXPRESSED IN HCCS COMPARED WITH NON-TUMOROUS LIVER TISSUE. TO ELUCIDATE THE ROLE OF DNMT3B IN HEPATOCARCINOGENESIS, WE GENERATED A GENETICALLY ENGINEERED MOUSE MODEL WITH HEPATOCYTE-SPECIFIC DNMT3B DELETION. THE LIVER OF THE DNMT3B-DEFICIENT MICE EXHIBITED AN EXACERBATION OF THIOACETAMIDE-INDUCED HEPATITIS, PROGRESSION OF LIVER FIBROSIS AND A HIGHER INCIDENCE OF HCC COMPARED WITH THE LIVER OF THE CONTROL MICE. WHOLE-GENOME BISULFITE SEQUENCING VERIFIED A LOWER CG METHYLATION LEVEL IN THE DNMT3B-DEFICIENT LIVER, DEMONSTRATING DIFFERENTIALLY METHYLATED REGIONS THROUGHOUT THE GENOME. TRANSCRIPTOME ANALYSIS REVEALED DECREASED EXPRESSION OF GENES RELATED TO OXIDATIVE PHOSPHORYLATION IN THE DNMT3B-DEFICIENT LIVER. MOREOVER, PRIMARY HEPATOCYTES ISOLATED FROM THE DNMT3B-DEFICIENT MICE SHOWED REDUCED MITOCHONDRIAL RESPIRATORY CAPACITY, LEADING TO THE ENHANCEMENT OF OXIDATIVE STRESS IN THE LIVER TISSUE. OUR FINDINGS SUGGEST THE PROTECTIVE ROLE OF DNMT3B AGAINST CHRONIC INFLAMMATION AND HCC DEVELOPMENT VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. 2020 5 5972 22 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 6 3527 26 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 7 273 46 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 8 2590 43 EPIGENETICS OF PROTEASOME INHIBITION IN THE LIVER OF RATS FED ETHANOL CHRONICALLY. AIM: TO EXAMINE THE EFFECTS OF ETHANOL-INDUCED PROTEASOME INHIBITION, AND THE EFFECTS OF PROTEASOME INHIBITION IN THE REGULATION OF EPIGENETIC MECHANISMS. METHODS: RATS WERE FED ETHANOL FOR 1 MO USING THE TSUKAMOTO-FRENCH MODEL AND WERE COMPARED TO RATS GIVEN THE PROTEASOME INHIBITOR PS-341 (BORTEZOMIB, VELCADE(TM)) BY INTRAPERITONEAL INJECTION. MICROARRAY ANALYSIS AND REAL TIME PCR WERE PERFORMED AND PROTEASOME ACTIVITY ASSAYS AND WESTERN BLOT ANALYSIS WERE PERFORMED USING ISOLATED NUCLEI. RESULTS: CHRONIC ETHANOL FEEDING CAUSED A SIGNIFICANT INHIBITION OF THE UBIQUITIN PROTEASOME PATHWAY IN THE NUCLEUS, WHICH LED TO CHANGES IN THE TURNOVER OF TRANSCRIPTIONAL FACTORS, HISTONE-MODIFYING ENZYMES, AND, THEREFORE, AFFECTED EPIGENETIC MECHANISMS. CHRONIC ETHANOL FEEDING WAS RELATED TO AN INCREASE IN HISTONE ACETYLATION, AND IT IS HYPOTHESIZED THAT THE PROTEASOME PROTEOLYTIC ACTIVITY REGULATED HISTONE MODIFICATIONS BY CONTROLLING THE STABILITY OF HISTONE MODIFYING ENZYMES, AND, THEREFORE, REGULATED THE CHROMATIN STRUCTURE, ALLOWING EASY ACCESS TO CHROMATIN BY RNA POLYMERASE, AND, THUS, PROPER GENE EXPRESSION. PROTEASOME INHIBITION BY PS-341 INCREASED HISTONE ACETYLATION SIMILAR TO CHRONIC ETHANOL FEEDING. IN ADDITION, PROTEASOME INHIBITION CAUSED DRAMATIC CHANGES IN HEPATIC REMETHYLATION REACTIONS AS THERE WAS A SIGNIFICANT DECREASE IN THE ENZYMES RESPONSIBLE FOR THE REGENERATION OF S-ADENOSYLMETHIONINE, AND, IN PARTICULAR, A SIGNIFICANT DECREASE IN THE BETAINE-HOMOCYSTEINE METHYLTRANSFERASE ENZYME. THIS SUGGESTED THAT HYPOMETHYLATION WAS ASSOCIATED WITH PROTEASOME INHIBITION, AS INDICATED BY THE DECREASE IN HISTONE METHYLATION. CONCLUSION: THE ROLE OF PROTEASOME INHIBITION IN REGULATING EPIGENETIC MECHANISMS, AND ITS LINK TO LIVER INJURY IN ALCOHOLIC LIVER DISEASE, IS THUS A PROMISING APPROACH TO STUDY LIVER INJURY DUE TO CHRONIC ETHANOL CONSUMPTION. 2009 9 2068 37 EPIGENETIC CONTROL OF MICROSOMAL PROSTAGLANDIN E SYNTHASE-1 BY HDAC-MEDIATED RECRUITMENT OF P300. NONSTEROIDAL ANTI-INFLAMMATORY DRUGS ARE THE MOST WIDELY USED MEDICINE TO TREAT PAIN AND INFLAMMATION, AND TO INHIBIT PLATELET FUNCTION. UNDERSTANDING THE EXPRESSION REGULATION OF ENZYMES OF THE PROSTANOID PATHWAY IS OF GREAT MEDICAL RELEVANCE. HISTONE ACETYLATION CRUCIALLY CONTROLS GENE EXPRESSION. WE SET OUT TO IDENTIFY THE IMPACT OF HISTONE DEACETYLASES (HDACS) ON THE GENERATION OF PROSTANOIDS AND EXAMINE THE CONSEQUENCES ON VASCULAR FUNCTION. HDAC INHIBITION (HDACI) WITH THE PAN-HDAC INHIBITOR, VORINOSTAT, ATTENUATED PROSTAGLANDIN (PG)E(2) GENERATION IN THE MURINE VASCULATURE AND IN HUMAN VASCULAR SMOOTH MUSCLE CELLS. IN LINE WITH THIS, THE EXPRESSION OF THE KEY ENZYME FOR PGE(2) SYNTHESIS, MICROSOMAL PGE SYNTHASE-1 (PTGES1), WAS REDUCED BY HDACI. ACCORDINGLY, THE RELAXATION TO ARACHIDONIC ACID WAS DECREASED AFTER EX VIVO INCUBATION OF MURINE VESSELS WITH HDACI. TO IDENTIFY THE UNDERLYING MECHANISM, CHROMATIN IMMUNOPRECIPITATION (CHIP) AND CHIP-SEQUENCING ANALYSIS WERE PERFORMED. THESE RESULTS SUGGEST THAT HDACS ARE INVOLVED IN THE RECRUITMENT OF THE TRANSCRIPTIONAL ACTIVATOR P300 TO THE PTGES1 GENE AND THAT HDACI PREVENTED THIS EFFECT. IN LINE WITH THE ACETYLTRANSFERASE ACTIVITY OF P300, H3K27 ACETYLATION WAS REDUCED AFTER HDACI AND RESULTED IN THE FORMATION OF HETEROCHROMATIN IN THE PTGES1 GENE. IN CONCLUSION, HDAC ACTIVITY MAINTAINS PTGES1 EXPRESSION BY RECRUITING P300 TO ITS GENE. 2017 10 2783 36 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 11 3330 35 HISTONE DEACETYLASE INHIBITOR GIVINOSTAT ALLEVIATES LIVER FIBROSIS BY REGULATING HEPATIC STELLATE CELL ACTIVATION. HEPATIC FIBROSIS, A COMMON PATHOLOGICAL MANIFESTATION OF CHRONIC LIVER INJURY, IS GENERALLY CONSIDERED TO BE THE END RESULT OF AN INCREASE IN EXTRACELLULAR MATRIX PRODUCED BY ACTIVATED HEPATIC STELLATE CELLS (HSCS). THE AIM OF THE PRESENT STUDY WAS TO TARGET THE MECHANISMS UNDERLYING HSC ACTIVATION IN ORDER TO PROVIDE A POWERFUL THERAPEUTIC STRATEGY FOR THE PREVENTION AND TREATMENT OF LIVER FIBROSIS. IN THE PRESENT STUDY, A HIGH?THROUGHPUT SCREENING ASSAY WAS ESTABLISHED, AND THE HISTONE DEACETYLASE INHIBITOR GIVINOSTAT WAS IDENTIFIED AS A POTENT INHIBITOR OF HSC ACTIVATION IN VITRO. GIVINOSTAT SIGNIFICANTLY INHIBITED HSC ACTIVATION IN VIVO, AMELIORATED CARBON TETRACHLORIDE?INDUCED MOUSE LIVER FIBROSIS AND LOWERED PLASMA AMINOTRANSFERASES. TRANSCRIPTOMIC ANALYSIS REVEALED THE MOST SIGNIFICANTLY REGULATED GENES IN THE GIVINOSTAT TREATMENT GROUP IN COMPARISON WITH THOSE IN THE SOLVENT GROUP, AMONG WHICH, DERMOKINE (DMKN), MESOTHELIN (MSLN) AND UROPLAKIN?3B (UPK3B) WERE IDENTIFIED AS POTENTIAL REGULATORS OF HSC ACTIVATION. GIVINOSTAT SIGNIFICANTLY REDUCED THE MRNA EXPRESSION OF DMKN, MSLN AND UPK3B IN BOTH A MOUSE LIVER FIBROSIS MODEL AND IN HSC?LX2 CELLS. KNOCKDOWN OF ANY OF THE AFOREMENTIONED GENES INHIBITED THE TGF?BETA1?INDUCED EXPRESSION OF ALPHA?SMOOTH MUSCLE ACTIN AND COLLAGEN TYPE I, INDICATING THAT THEY ARE CRUCIAL FOR HSC ACTIVATION. IN SUMMARY, USING A NOVEL STRATEGY TARGETING HSC ACTIVATION, THE PRESENT STUDY IDENTIFIED A POTENTIAL EPIGENETIC DRUG FOR THE TREATMENT OF HEPATIC FIBROSIS AND REVEALED NOVEL REGULATORS OF HSC ACTIVATION. 2021 12 2825 43 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 13 3658 33 INDUCTION OF ABERRANT TRIMETHYLATION OF HISTONE H3 LYSINE 27 BY INFLAMMATION IN MOUSE COLONIC EPITHELIAL CELLS. A FIELD FOR CANCERIZATION (FIELD DEFECT), WHERE GENETIC AND EPIGENETIC ALTERATIONS ARE ACCUMULATED IN NORMAL-APPEARING TISSUES, IS INVOLVED IN HUMAN CARCINOGENESIS, ESPECIALLY CANCERS ASSOCIATED WITH CHRONIC INFLAMMATION. ALTHOUGH ABERRANT DNA METHYLATION IS INVOLVED IN THE FIELD DEFECT AND INDUCED BY CHRONIC INFLAMMATION, IT IS STILL UNCLEAR FOR TRIMETHYLATION OF HISTONE H3 LYSINE 27 (H3K27ME3), WHICH IS INVOLVED IN GENE REPRESSION INDEPENDENT OF DNA METHYLATION AND FUNCTIONS AS A PRE-MARK FOR ABERRANT DNA METHYLATION. IN THIS STUDY, USING A MOUSE COLITIS MODEL INDUCED BY DEXTRAN SULFATE SODIUM (DSS), WE AIMED TO CLARIFY WHETHER ABERRANT H3K27ME3 IS INDUCED BY INFLAMMATION AND INVOLVED IN A FIELD DEFECT. CHIP-ON-CHIP ANALYSIS OF COLONIC EPITHELIAL CELLS REVEALED THAT H3K27ME3 LEVELS WERE INCREASED OR DECREASED FOR 266 GENOMIC REGIONS BY AGING, AND MORE EXTENSIVELY (23 INCREASED AND 3574 DECREASED REGIONS) BY COLITIS. SUCH INCREASE OR DECREASE OF H3K27ME3 WAS INDUCED AS EARLY AS 2 WEEKS AFTER THE INITIATION OF DSS TREATMENT, AND PERSISTED AT LEAST FOR 16 WEEKS EVEN AFTER THE INFLAMMATION DISAPPEARED. SOME OF THE ABERRANT H3K27ME3 IN COLONIC EPITHELIAL CELLS WAS CARRIED OVER INTO COLON TUMORS. FURTHERMORE, H3K27ME3 ACQUIRED AT DAPK1 BY COLITIS WAS FOLLOWED BY INCREASED DNA METHYLATION, SUPPORTING ITS FUNCTION AS A PRE-MARK FOR ABERRANT DNA METHYLATION. THESE RESULTS DEMONSTRATED THAT ABERRANT H3K27ME3 CAN BE INDUCED BY EXPOSURE TO A SPECIFIC ENVIRONMENT, SUCH AS COLITIS, AND SUGGESTED THAT ABERRANT HISTONE MODIFICATION, IN ADDITION TO ABERRANT DNA METHYLATION, IS INVOLVED IN THE FORMATION OF A FIELD DEFECT. 2012 14 4302 35 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 15 5995 29 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 16 2774 37 EXTRACELLULAR SUPEROXIDE DISMUTASE (EC-SOD) REGULATES GENE METHYLATION AND CARDIAC FIBROSIS DURING CHRONIC HYPOXIC STRESS. CHRONIC HYPOXIC STRESS INDUCES EPIGENETIC MODIFICATIONS MAINLY DNA METHYLATION IN CARDIAC FIBROBLASTS, INACTIVATING TUMOR SUPPRESSOR GENES (RASSF1A) AND ACTIVATING KINASES (ERK1/2) LEADING TO FIBROBLAST PROLIFERATION AND CARDIAC FIBROSIS. THE RAS/ERK SIGNALING PATHWAY IS AN INTRACELLULAR SIGNAL TRANSDUCTION CRITICALLY INVOLVED IN FIBROBLAST PROLIFERATION. RASSF1A FUNCTIONS THROUGH ITS EFFECT ON DOWNSTREAM ERK1/2. THE ANTIOXIDANT ENZYME, EXTRACELLULAR SUPEROXIDE DISMUTASE (EC-SOD), DECREASES OXIDATIVE STRESS FROM CHRONIC HYPOXIA, BUT ITS EFFECTS ON THESE EPIGENETIC CHANGES HAVE NOT BEEN FULLY EXPLORED. TO TEST OUR HYPOTHESIS, WE USED AN IN-VITRO MODEL: WILD-TYPE C57B6 MALE MICE (WT) AND TRANSGENIC MALES WITH AN EXTRA COPY OF HUMAN HEC-SOD (TG). THE STUDIED ANIMALS WERE HOUSED IN HYPOXIA (10% O(2)) FOR 21 DAYS. THE RIGHT VENTRICULAR TISSUE WAS STUDIED FOR CARDIAC FIBROSIS MARKERS USING RT-PCR AND WESTERN BLOT ANALYSES. PRIMARY C57BL6 MOUSE CARDIAC FIBROBLAST TISSUE CULTURE WAS USED TO STUDY THE IN-VITRO MODEL, THE DOWNSTREAM EFFECTS OF RASSF-1 EXPRESSION AND METHYLATION, AND ITS RELATION TO ERK1/2. OUR FINDINGS SHOWED A SIGNIFICANT INCREASE IN CARDIAC FIBROSIS MARKERS: COLLAGEN 1, ALPHA SMOOTH MUSCLE ACTIN (ASMA), AND SNAIL, IN THE WT HYPOXIC ANIMALS AS COMPARED TO THE TG HYPOXIC GROUP (P < 0.05). THE EXPRESSION OF DNA METHYLATION ENZYMES (DNMT 1&3B) WAS SIGNIFICANTLY INCREASED IN THE WT HYPOXIC MICE AS COMPARED TO THE HYPOXIC TG MICE (P < 0.001). RASSF1A EXPRESSION WAS SIGNIFICANTLY LOWER AND ERK1/2 WAS SIGNIFICANTLY HIGHER IN HYPOXIA WT COMPARED TO THE HYPOXIC TG GROUP (P < 0.05). USE OF SIRNA TO BLOCK RASSF1A GENE EXPRESSION IN MURINE CARDIAC FIBROBLAST TISSUE CULTURE LED TO INCREASED FIBROBLAST PROLIFERATION (P < 0.05). METHYLATION OF THE RASSF1A PROMOTER REGION WAS SIGNIFICANTLY REDUCED IN THE TG HYPOXIC GROUP COMPARED TO THE WT HYPOXIC GROUP (0.59 VS. 0.75, RESPECTIVELY). BASED ON OUR FINDINGS, WE CAN SPECULATE THAT EC-SOD SIGNIFICANTLY ATTENUATES RASSF1A GENE METHYLATION AND CAN ALLEVIATE CARDIAC FIBROSIS INDUCED BY HYPOXIA. 2021 17 3660 33 INDUCTION OF HEPATIC DIFFERENTIATION OF MOUSE BONE MARROW STROMAL STEM CELLS BY THE HISTONE DEACETYLASE INHIBITOR VPA. BONE MARROW STROMAL STEM CELLS (BMSSCS) MAY HAVE POTENTIAL TO DIFFERENTIATE IN VITRO AND IN VIVO INTO HEPATOCYTES. HERE, WE INVESTIGATED THE EFFECTS OF VALPROIC ACID (VPA) INVOLVED IN EPIGENETIC MODIFICATION, A DIRECT INHIBITOR OF HISTONE DEACETYLASE, ON HEPATIC DIFFERENTIATION OF MOUSE BMSSCS. FOLLOWING THE TREATMENT OF 2.5 MM VPA FOR 72 HRS, THE IN VITRO EXPANDED, HIGHLY PURIFIED AND FUNCTIONALLY ACTIVE MOUSE BMSSCS FROM BONE MARROW WERE EITHER EXPOSED TO SOME WELL-DEFINED CYTOKINES AND GROWTH FACTORS IN A SEQUENTIAL WAY (FIBROBLAST GROWTH FACTOR-4 [FGF-4], FOLLOWED BY HGF, AND HGF + OSM + ITS + DEXAMETHASONE, RESEMBLING THE ORDER OF SECRETION DURING LIVER EMBRYOGENESIS) OR TRANSPLANTED (CAUDAL VEIN) IN MICE SUBMITTED TO A PROTOCOL OF CHRONIC INJURY (CHRONIC I.P. INJECTION OF CCL4). ADDITIONAL EXPOSURE OF THE CELLS TO VPA CONSIDERABLY IMPROVED THE IN VITRO DIFFERENTIATION, AS DEMONSTRATED BY A MORE HOMOGENEOUS CELL POPULATION EXHIBITED EPITHELIAL MORPHOLOGY, INCREASING EXPRESSION OF HEPATIC SPECIAL GENES AND ENHANCED HEPATIC FUNCTIONS. FURTHER MORE, IN VIVO RESULTS INDICATE THAT THE PRE-TREATMENT OF VPA SIGNIFICANTLY INCREASED THE HOMING EFFICIENCY OF BMSSCS TO THE SITE OF LIVER INJURY AND, ADDITIONALLY, FOR SUPPORTING HEPATIC DIFFERENTIATION AS WELL AS IN VITRO. WE HAVE DEMONSTRATED THE USEFULNESS OF VPA IN THE TRANSDIFFERENTIATION OF BMSSCS INTO HEPATOCYTES BOTH IN VITRO AND IN VIVO, AND REGULATION OF FIBROBLAST GROWTH FACTOR RECEPTORS (FGFRS) AND C-MET GENE EXPRESSION THROUGH POST-TRANSLATIONAL MODIFICATION OF CORE HISTONES MIGHT BE THE PRIMARY INITIATING EVENT FOR THESE EFFECTS. THIS MODE COULD BE HELPFUL FOR LIVER ENGINEERING AND CLINICAL THERAPY. 2009 18 6419 29 THE TET2-UPF1 COMPLEX MODULATES MRNA STABILITY UNDER STRESS CONDITIONS. INTRODUCTION: ENVIRONMENTAL STRESS PROMOTES EPIGENETIC ALTERATIONS THAT IMPACT GENE EXPRESSION AND SUBSEQUENTLY PARTICIPATE IN THE PATHOLOGICAL PROCESSES OF THE DISORDER. AMONG EPIGENETIC REGULATIONS, TEN-ELEVEN TRANSLOCATION (TET) ENZYMES OXIDIZE 5-METHYLCYTOSINE (5MC) TO 5-HYDROXYMETHYLCYTOSINE (5HMC) IN DNA AND RNA AND FUNCTION AS CRITICAL PLAYERS IN THE PATHOGENESIS OF DISEASES. OUR PREVIOUS RESULTS SHOWED THAT CHRONIC STRESS INCREASES THE EXPRESSION OF CYTOPLASMIC TET2 IN THE HIPPOCAMPUS OF MICE EXPOSED TO CHRONIC MILD STRESS (CMS). WHETHER THE CYTOPLASMIC TET2 ALTERS RNA 5HMC MODIFICATION IN CHRONIC STRESS-RELATED PROCESSES REMAINS LARGELY UNKNOWN. METHODS: TO EXPLORE THE ROLE OF CYTOPLASMIC TET2 UNDER CMS CONDITIONS, WE ESTABLISHED CMS MICE MODEL AND DETECTED THE EXPRESSION OF RNA 5HMC BY DOT BLOT. WE VERIFIED THE INTERACTION OF TET2 AND ITS INTERACTING PROTEIN BY CO-IMMUNOPRECIPITATION COMBINED WITH MASS SPECTROMETRY AND SCREENED DOWNSTREAM TARGET GENES BY CLUSTER ANALYSIS OF TET2 AND UPSTREAM FRAMESHIFT 1 (UPF1) INTERACTING RNA. THE EXPRESSION OF PROTEIN WAS DETECTED BY WESTERN BLOT AND THE EXPRESSION OF THE SCREENED TARGET GENES WAS DETECTED BY QRT-PCR. RESULTS: IN THIS STUDY, WE FOUND THAT INCREASED CYTOPLASMIC TET2 EXPRESSION UNDER CMS CONDITIONS LEADS TO INCREASE IN TOTAL RNA 5HMC MODIFICATION. TET2 INTERACTED WITH THE KEY NON-SENSE-MEDIATED MRNA DECAY (NMD) FACTOR UPF1, REGULATED THE STABILITY OF STRESS-RELATED GENES SUCH AS UNC5B MRNA, AND MIGHT THEREBY AFFECT NEURODEVELOPMENT. DISCUSSION: IN SUMMARY, THIS STUDY REVEALED THAT TET2-MEDIATED RNA 5HMC MODIFICATION IS INVOLVED IN STRESS-RELATED MRNA STABILITY REGULATION AND MAY SERVE AS A POTENTIAL THERAPEUTIC TARGET FOR CHRONIC STRESS-RELATED DISEASES SUCH AS DEPRESSION. 2023 19 5088 33 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 20 6765 36 ZINC DEFICIENCY LEADS TO REDUCED INTERLEUKIN-2 PRODUCTION BY ACTIVE GENE SILENCING DUE TO ENHANCED CREMALPHA EXPRESSION IN T CELLS. BACKGROUND & AIMS: THE MICRONUTRIENT ZINC IS ESSENTIAL FOR PROPER IMMUNE FUNCTION. CONSEQUENTLY, ZINC DEFICIENCY LEADS TO IMPAIRED IMMUNE FUNCTION, AS SEEN IN DECREASED SECRETION OF INTERLEUKIN (IL)-2 BY T CELLS. ALTHOUGH THIS ASSOCIATION HAS BEEN KNOWN SINCE THE LATE 1980S, THE UNDERLYING MOLECULAR MECHANISMS ARE STILL UNKNOWN. ZINC DEFICIENCY AND REDUCED IL-2 LEVELS ARE ESPECIALLY FOUND IN THE ELDERLY, WHICH IN TURN ARE PRONE TO CHRONIC DISEASES. HERE, WE DESCRIBE A NEW MOLECULAR LINK BETWEEN ZINC DEFICIENCY AND REDUCED IL-2 EXPRESSION IN T CELLS. METHODS: THE EFFECTS OF ZINC DEFICIENCY WERE FIRST INVESTIGATED IN VITRO IN THE HUMAN T CELL LINES JURKAT AND HUT-78 AND COMPLEMENTED BY IN VIVO DATA FROM ZINC-SUPPLEMENTED PIGS. A SHORT- AND LONG-TERM MODEL FOR ZINC DEFICIENCY WAS ESTABLISHED. ZINC LEVELS WERE DETECTED BY FLOW CYTOMETRY AND EXPRESSION PROFILES WERE INVESTIGATED ON THE MRNA AND PROTEIN LEVEL. RESULTS: THE EXPRESSION OF THE TRANSCRIPTION FACTOR CAMP-RESPONSIVE-ELEMENT MODULATOR ALPHA (CREMALPHA) IS INCREASED DURING ZINC DEFICIENCY IN VITRO, DUE TO INCREASED PROTEIN PHOSPHATASE 2A (PP2A) ACTIVITY, RESULTING IN DECREASED IL-2 PRODUCTION. ADDITIONALLY, ZINC SUPPLEMENTATION IN VIVO REDUCED CREMALPHA LEVELS CAUSING INCREASED IL-2 EXPRESSION. ON EPIGENETIC LEVELS INCREASED CREMALPHA BINDING TO THE IL-2 PROMOTER IS MEDIATED BY HISTONE DEACETYLASE 1 (HDAC1). THE HDAC1 ACTIVITY IS INHIBITED BY ZINC. MOREOVER, DEACETYLATION OF THE ACTIVATING HISTONE MARK H3K9 WAS INCREASED UNDER ZINC DEFICIENCY, RESULTING IN REDUCED IL-2 EXPRESSION. CONCLUSIONS: WITH THE TRANSCRIPTION FACTOR CREMALPHA A MOLECULAR LINK WAS UNCOVERED, CONNECTING ZINC DEFICIENCY WITH REDUCED IL-2 PRODUCTION DUE TO ENHANCED PP2A AND HDAC1 ACTIVITY. 2021