1 6145 355 THE EXPANDING PHENOTYPES OF COHESINOPATHIES: ONE RING TO RULE THEM ALL! PRESERVATION AND DEVELOPMENT OF LIFE DEPEND ON THE ADEQUATE SEGREGATION OF SISTER CHROMATIDS DURING MITOSIS AND MEIOSIS. THIS PROCESS IS ENSURED BY THE COHESIN MULTI-SUBUNIT COMPLEX. MUTATIONS IN THIS COMPLEX HAVE BEEN ASSOCIATED WITH AN INCREASING NUMBER OF DISEASES, TERMED COHESINOPATHIES. THE BEST CHARACTERIZED COHESINOPATHY IS CORNELIA DE LANGE SYNDROME (CDLS), IN WHICH INTELLECTUAL AND GROWTH RETARDATIONS ARE THE MAIN PHENOTYPIC MANIFESTATIONS. DESPITE SOME OVERLAP, THE CLINICAL MANIFESTATIONS OF COHESINOPATHIES VARY CONSIDERABLY. NOVEL ROLES OF THE COHESIN COMPLEX HAVE EMERGED DURING THE PAST DECADES, SUGGESTING THAT IMPORTANT CELL CYCLE REGULATORS EXERT IMPORTANT BIOLOGICAL EFFECTS THROUGH NON-COHESION-RELATED FUNCTIONS AND BROADENING THE POTENTIAL PATHOMECHANISMS INVOLVED IN COHESINOPATHIES. THIS REVIEW FOCUSES ON NON-COHESION-RELATED FUNCTIONS OF THE COHESIN COMPLEX, GENE DOSAGE EFFECT, EPIGENETIC REGULATION AND TGF-BETA IN COHESINOPATHY CONTEXT, ESPECIALLY IN COMPARISON TO CHRONIC ATRIAL AND INTESTINAL DYSRHYTHMIA (CAID) SYNDROME, A VERY DISTINCT COHESINOPATHY CAUSED BY A HOMOZYGOUS SHUGOSHIN-1 (SGO1) MUTATION (K23E) AND CHARACTERIZED BY PACEMAKER FAILURE IN BOTH HEART (SICK SINUS SYNDROME FOLLOWED BY ATRIAL FLUTTER) AND GUT (CHRONIC INTESTINAL PSEUDO-OBSTRUCTION) WITH NO INTELLECTUAL OR GROWTH DELAY. WE DISCUSS THE POSSIBLE IMPACT OF SGO1 ALTERATIONS IN HUMAN PATHOLOGIES AND THE POTENTIAL IMPACT OF THE SGO1 K23E MUTATION IN THE SINUS NODE AND GUT DEVELOPMENT AND FUNCTIONS. WE SUGGEST THAT THE HUMAN PHENOTYPES OBSERVED IN CDLS, CAID SYNDROME AND OTHER COHESINOPATHIES CAN INFORM FUTURE STUDIES INTO THE LESS WELL-KNOWN NON-COHESION-RELATED FUNCTIONS OF COHESIN COMPLEX GENES. ABBREVIATIONS: AD: ALZHEIMER DISEASE; AFF4: AF4/FMR2 FAMILY MEMBER 4; ANKRD11: ANKYRIN REPEAT DOMAIN 11; APC: ANAPHASE PROMOTER COMPLEX; ASD: ATRIAL SEPTAL DEFECT; ATRX: ATRX CHROMATIN REMODELER; ATRX: ALPHA THALASSEMIA X-LINKED INTELLECTUAL DISABILITY SYNDROME; BIRC5: BACULOVIRAL IAP REPEAT CONTAINING 5; BMP: BONE MORPHOGENETIC PROTEIN; BRD4: BROMODOMAIN CONTAINING 4; BUB1: BUB1 MITOTIC CHECKPOINT SERINE/THREONINE KINASE; CAID: CHRONIC ATRIAL AND INTESTINAL DYSRHYTHMIA; CDK1: CYCLIN DEPENDENT KINASE 1; CDLS: CORNELIA DE LANGE SYNDROME; CHD: CONGENITAL HEART DISEASE; CHOPS: COGNITIVE IMPAIRMENT, COARSE FACIES, HEART DEFECTS, OBESITY, PULMONARY INVOLVEMENT, SHORT STATURE, AND SKELETAL DYSPLASIA; CIPO: CHRONIC INTESTINAL PSEUDO-OBSTRUCTION; C-KIT: KIT PROTO-ONCOGENE RECEPTOR TYROSINE KINASE; COATS: COHESIN ACETYLTRANSFERASES; CTCF: CCCTC-BINDING FACTOR; DDX11: DEAD/H-BOX HELICASE 11; ERG: TRANSCRIPTIONAL REGULATOR ERG; ESCO2: ESTABLISHMENT OF SISTER CHROMATID COHESION N-ACETYLTRANSFERASE 2; GJC1: GAP JUNCTION PROTEIN GAMMA 1; H2A: HISTONE H2A; H3K4: HISTONE H3 LYSINE 4; H3K9: HISTONE H3 LYSINE 9; HCN4: HYPERPOLARIZATION ACTIVATED CYCLIC NUCLEOTIDE GATED POTASSIUM AND SODIUM CHANNEL 4;P HDAC8: HISTONE DEACETYLASES 8; HP1: HETEROCHROMATIN PROTEIN 1; ICC: INTERSTITIAL CELLS OF CAJAL; ICC-MP: MYENTERIC PLEXUS INTERSTITIAL CELLS OF CAJAL; ICC-DMP: DEEP MUSCULAR PLEXUS INTERSTITIAL CELLS OF CAJAL; I(F): PACEMAKER FUNNY CURRENT; IP3: INOSITOL TRISPHOSPHATE; JNK: C-JUN N-TERMINAL KINASE; LDS: LOEYS-DIETZ SYNDROME; LOAD: LATE-ONSET ALZHEIMER DISEASE; MAPK: MITOGEN-ACTIVATED PROTEIN KINASE; MAU: MAU SISTER CHROMATID COHESION FACTOR; MFS: MARFAN SYNDROME; NIPBL: NIPBL, COHESIN LOADING FACTOR; OCT4: OCTAMER-BINDING PROTEIN 4; P38: P38 MAP KINASE; PDA: PATENT DUCTUS ARTERIOSUS; PDS5: PDS5 COHESIN ASSOCIATED FACTOR; P-H3: PHOSPHO HISTONE H3; PLK1: POLO LIKE KINASE 1; POPDC1: POPEYE DOMAIN CONTAINING 1; POPDC2: POPEYE DOMAIN CONTAINING 2; PP2A: PROTEIN PHOSPHATASE 2; RAD21: RAD21 COHESIN COMPLEX COMPONENT; RBS: ROBERTS SYNDROME; REC8: REC8 MEIOTIC RECOMBINATION PROTEIN; RNAP2: RNA POLYMERASE II; SAN: SINOATRIAL NODE; SCN5A: SODIUM VOLTAGE-GATED CHANNEL ALPHA SUBUNIT 5; SEC: SUPER ELONGATION COMPLEX; SGO1: SHOGOSHIN-1; SMAD: SMAD FAMILY MEMBER; SMC1A: STRUCTURAL MAINTENANCE OF CHROMOSOMES 1A; SMC3: STRUCTURAL MAINTENANCE OF CHROMOSOMES 3; SNV: SINGLE NUCLEOTIDE VARIANT; SOX2: SRY-BOX 2; SOX17: SRY-BOX 17; SSS: SICK SINUS SYNDROME; STAG2: COHESIN SUBUNIT SA-2; TADS: TOPOLOGY ASSOCIATED DOMAINS; TBX: T-BOX TRANSCRIPTION FACTORS; TGF-BETA: TRANSFORMING GROWTH FACTOR BETA; TGFBR: TRANSFORMING GROWTH FACTOR BETA RECEPTOR; TOF: TETRALOGY OF FALLOT; TREK1: TREK-1 K(+) CHANNEL SUBUNIT; VSD: VENTRICULAR SEPTAL DEFECT; WABS: WARSAW BREAKAGE SYNDROME; WAPL: WAPL COHESIN RELEASE FACTOR. 2019 2 4484 53 MOLECULAR SIGNATURE OF CAID SYNDROME: NONCANONICAL ROLES OF SGO1 IN REGULATION OF TGF-BETA SIGNALING AND EPIGENOMICS. BACKGROUND & AIMS: A GENERALIZED HUMAN PACEMAKING SYNDROME, CHRONIC ATRIAL AND INTESTINAL DYSRHYTHMIA (CAID) (OMIM 616201), IS CAUSED BY A HOMOZYGOUS SGO1 MUTATION (K23E), LEADING TO CHRONIC INTESTINAL PSEUDO-OBSTRUCTION AND ARRHYTHMIAS. BECAUSE CAID PATIENTS DO NOT SHOW PHENOTYPES CONSISTENT WITH PERTURBATION OF KNOWN ROLES OF SGO1, WE HYPOTHESIZED THAT NONCANONICAL ROLES OF SGO1 DRIVE THE CLINICAL MANIFESTATIONS OBSERVED. METHODS: TO IDENTIFY A MOLECULAR SIGNATURE FOR CAID SYNDROME, WE ACHIEVED UNBIASED SCREENS IN CELL LINES AND GUT TISSUES FROM CAID PATIENTS VS WILD-TYPE CONTROLS. WE PERFORMED RNA SEQUENCING ALONG WITH STABLE ISOTOPE LABELING WITH AMINO ACIDS IN CELL CULTURE. IN ADDITION, WE DETERMINED THE GENOME-WIDE DNA METHYLATION AND CHROMATIN ACCESSIBILITY SIGNATURES USING REDUCED REPRESENTATIVE BISULFITE SEQUENCING AND ASSAY FOR TRANSPOSASE-ACCESSIBLE CHROMATIN WITH HIGH-THROUGHPUT SEQUENCING. FUNCTIONAL STUDIES INCLUDED PATCH-CLAMP, QUANTITATION OF TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) SIGNALING, AND IMMUNOHISTOCHEMISTRY IN CAID PATIENT GUT BIOPSY SPECIMENS. RESULTS: PROTEOME AND TRANSCRIPTOME STUDIES CONVERGE ON CELL-CYCLE REGULATION, CARDIAC CONDUCTION, AND SMOOTH MUSCLE REGULATION AS DRIVERS OF CAID SYNDROME. SPECIFICALLY, THE INWARD RECTIFIER CURRENT, AN IMPORTANT REGULATOR OF CELLULAR FUNCTION, WAS DISRUPTED. IMMUNOHISTOCHEMISTRY CONFIRMED OVEREXPRESSION OF BUDDING UNINHIBITED BY BENZIMIDAZOLES 1 (BUB1) IN PATIENTS, IMPLICATING THE TGF-BETA PATHWAY IN CAID PATHOGENESIS. CANONICAL TGF-BETA SIGNALING WAS UP-REGULATED AND UNCOUPLED FROM NONCANONICAL SIGNALING IN CAID PATIENTS. REDUCED REPRESENTATIVE BISULFITE SEQUENCING AND ASSAY FOR TRANSPOSASE-ACCESSIBLE CHROMATIN WITH HIGH-THROUGHPUT SEQUENCING EXPERIMENTS SHOWED SIGNIFICANT CHANGES OF CHROMATIN STATES IN CAID, POINTING TO EPIGENETIC REGULATION AS A POSSIBLE PATHOLOGIC MECHANISM. CONCLUSIONS: OUR FINDINGS POINT TO IMPAIRED INWARD RECTIFIER POTASSIUM CURRENT, DYSREGULATION OF CANONICAL TGF-BETA SIGNALING, AND EPIGENETIC REGULATION AS POTENTIAL DRIVERS OF INTESTINAL AND CARDIAC MANIFESTATIONS OF CAID SYNDROME. TRANSCRIPT PROFILING AND GENOMICS DATA ARE AS FOLLOWS: REPOSITORY URL: HTTPS://WWW.NCBI.NLM.NIH.GOV/GEO; SUPERSERIES GSE110612 WAS COMPOSED OF THE FOLLOWING SUBSERIES: GSE110309, GSE110576, AND GSE110601. 2019 3 1092 45 COHESIN MUTATIONS IN MYELOID MALIGNANCIES. COHESIN IS A MULTISUBUNIT PROTEIN COMPLEX THAT FORMS A RING-LIKE STRUCTURE AROUND DNA. IT IS ESSENTIAL FOR SISTER CHROMATID COHESION, CHROMATIN ORGANIZATION, TRANSCRIPTIONAL REGULATION, AND DNA DAMAGE REPAIR AND PLAYS A MAJOR ROLE IN DYNAMICALLY SHAPING THE GENOME ARCHITECTURE AND MAINTAINING DNA INTEGRITY. THE CORE COMPLEX SUBUNITS STAG2, RAD21, SMC1, AND SMC3, AS WELL AS ITS MODULATORS PDS5A/B, WAPL, AND NIPBL, HAVE BEEN FOUND TO BE RECURRENTLY MUTATED IN HEMATOLOGIC AND SOLID MALIGNANCIES. THESE MUTATIONS ARE FOUND ACROSS THE FULL SPECTRUM OF MYELOID NEOPLASIA, INCLUDING PEDIATRIC DOWN SYNDROME-ASSOCIATED ACUTE MEGAKARYOBLASTIC LEUKEMIA, MYELODYSPLASTIC SYNDROMES, CHRONIC MYELOMONOCYTIC LEUKEMIA, AND DE NOVO AND SECONDARY ACUTE MYELOID LEUKEMIAS. THE MECHANISMS BY WHICH COHESIN MUTATIONS ACT AS DRIVERS OF CLONAL EXPANSION AND DISEASE PROGRESSION ARE STILL POORLY UNDERSTOOD. RECENT STUDIES HAVE DESCRIBED THE IMPACT OF COHESIN ALTERATIONS ON SELF-RENEWAL AND DIFFERENTIATION OF HEMATOPOIETIC STEM AND PROGENITOR CELLS, WHICH ARE ASSOCIATED WITH CHANGES IN CHROMATIN AND EPIGENETIC STATE DIRECTING LINEAGE COMMITMENT, AS WELL AS GENOMIC INTEGRITY. HEREIN, WE REVIEW THE ROLE OF THE COHESIN COMPLEX IN HEALTHY AND MALIGNANT HEMATOPOIESIS. WE DISCUSS CLINICAL IMPLICATIONS OF COHESIN MUTATIONS IN MYELOID MALIGNANCIES AND DISCUSS OPPORTUNITIES FOR THERAPEUTIC TARGETING. 2021 4 5527 36 RNA HELICASE DEAD BOX PROTEIN 5 REGULATES POLYCOMB REPRESSIVE COMPLEX 2/HOX TRANSCRIPT ANTISENSE INTERGENIC RNA FUNCTION IN HEPATITIS B VIRUS INFECTION AND HEPATOCARCINOGENESIS. CHRONIC HEPATITIS B VIRUS (HBV) INFECTION IS A MAJOR FACTOR IN HEPATOCELLULAR CARCINOMA (HCC) PATHOGENESIS BY A MECHANISM NOT YET UNDERSTOOD. ELUCIDATING MECHANISMS OF HBV-MEDIATED HEPATOCARCINOGENESIS IS NEEDED TO GAIN INSIGHTS INTO CLASSIFICATION AND TREATMENT OF HCC. IN HBV REPLICATING CELLS, INCLUDING VIRUS-ASSOCIATED HCCS, SUPPRESSOR OF ZESTE 12 HOMOLOG (SUZ12), A CORE SUBUNIT OF POLYCOMB REPRESSIVE COMPLEX2 (PRC2), UNDERGOES PROTEASOMAL DEGRADATION. THIS PROCESS REQUIRES THE LONG NONCODING RNA, HOX TRANSCRIPT ANTISENSE INTERGENIC RNA (HOTAIR). INTRIGUINGLY, HOTAIR INTERACTS WITH PRC2 AND ALSO BINDS RNA-BINDING E3 LIGASES, SERVING AS A UBIQUITINATION SCAFFOLD. HEREIN, WE IDENTIFIED THE RNA HELICASE, DEAD BOX PROTEIN 5 (DDX5), AS A REGULATOR OF SUZ12 STABILITY AND PRC2-MEDIATED GENE REPRESSION, ACTING BY REGULATING RNA-PROTEIN COMPLEXES FORMED WITH HOTAIR. SPECIFICALLY, KNOCKDOWN OF DDX5 AND/OR HOTAIR ENABLED REEXPRESSION OF PRC2-REPRESSED GENES EPITHELIAL CELL ADHESION MOLECULE (EPCAM) AND PLURIPOTENCY GENES. ALSO, KNOCKDOWN OF DDX5 ENHANCED TRANSCRIPTION FROM THE HBV MINICHROMOSOME. THE HELICASE ACTIVITY OF DDX5 STABILIZED SUZ12- AND PRC2-MEDIATED GENE SILENCING, BY DISPLACING THE RNA-BINDING E3 LIGASE, MEX-3 RNA-BINDING FAMILY MEMBER B (MEX3B), FROM HOTAIR. CONVERSELY, ECTOPIC EXPRESSION OF MEX3B UBIQUITINATED SUZ12, DISPLACED DDX5 FROM HOTAIR, AND INDUCED SUZ12 DOWN-REGULATION. IN G2 PHASE OF CELLS EXPRESSING THE HBV X PROTEIN (HBX), SUZ12 PREFERENTIALLY ASSOCIATED WITH MEX3B, BUT NOT DDX5, RESULTING IN DE-REPRESSION OF PRC2 TARGETS, INCLUDING EPCAM AND PLURIPOTENCY GENES. SIGNIFICANTLY, LIVER TUMORS FROM HBX/C-MYC BITRANSGENIC MICE AND CHRONICALLY HBV-INFECTED PATIENTS EXHIBITED A STRONG NEGATIVE CORRELATION BETWEEN DDX5 MESSENGER RNA LEVELS, PLURIPOTENCY GENE EXPRESSION, AND LIVER TUMOR DIFFERENTIATION. NOTABLY, CHRONICALLY INFECTED HBV PATIENTS WITH HCC EXPRESSING REDUCED DDX5 EXHIBITED POOR PROGNOSIS AFTER TUMOR RESECTION, IDENTIFYING DDX5 AS AN IMPORTANT PLAYER IN POOR PROGNOSIS HCC. CONCLUSION: THE RNA HELICASE DDX5, AND E3 LIGASE MEX3B, ARE IMPORTANT CELLULAR TARGETS FOR THE DESIGN OF NOVEL, EPIGENETIC THERAPIES TO COMBAT HBV INFECTION AND POOR PROGNOSIS HBV-ASSOCIATED LIVER CANCER. (HEPATOLOGY 2016;64:1033-1048). 2016 5 6569 40 TRANSPLANTATION OF EPIGENETICALLY MODIFIED ADULT CARDIAC C-KIT+ CELLS RETARDS REMODELING AND IMPROVES CARDIAC FUNCTION IN ISCHEMIC HEART FAILURE MODEL. CARDIAC C-KIT+ CELLS HAVE A MODEST CARDIOGENIC POTENTIAL THAT COULD LIMIT THEIR EFFICACY IN HEART DISEASE TREATMENT. THE PRESENT STUDY WAS DESIGNED TO AUGMENT THE CARDIOGENIC POTENTIAL OF CARDIAC C-KIT+ CELLS THROUGH CLASS I HISTONE DEACETYLASE (HDAC) INHIBITION AND EVALUATE THEIR THERAPEUTIC POTENCY IN THE CHRONIC HEART FAILURE (CHF) ANIMAL MODEL. MYOCARDIAL INFARCTION (MI) WAS CREATED BY CORONARY ARTERY OCCLUSION IN RATS. C-KIT+ CELLS WERE TREATED WITH MOCETINOSTAT (MOCE), A SPECIFIC CLASS I HDAC INHIBITOR. AT 3 WEEKS AFTER MI, CHF ANIMALS WERE RETROGRADELY INFUSED WITH UNTREATED (CONTROL) OR MOCE-TREATED C-KIT+ CELLS (MOCE/C-KIT+ CELLS) AND EVALUATED AT 3 WEEKS AFTER CELL INFUSION. WE FOUND THAT CLASS I HDAC INHIBITION IN C-KIT+ CELLS ELEVATED THE LEVEL OF ACETYLATED HISTONE H3 (ACH3) AND INCREASED ACH3 LEVELS IN THE PROMOTER REGIONS OF PLURIPOTENT AND CARDIAC-SPECIFIC GENES. EPIGENETIC CHANGES WERE ACCOMPANIED BY INCREASED EXPRESSION OF CARDIAC-SPECIFIC MARKERS. TRANSPLANTATION OF CHF RATS WITH EITHER CONTROL OR MOCE/C-KIT+ CELLS RESULTED IN AN IMPROVEMENT IN CARDIAC FUNCTION, RETARDATION OF CHF REMODELING MADE EVIDENT BY INCREASED VASCULARIZATION AND SCAR SIZE, AND CARDIOMYOCYTE HYPERTROPHY REDUCTION. COMPARED WITH CHF INFUSED WITH CONTROL CELLS, INFUSION OF MOCE/C-KIT+ CELLS RESULTED IN A FURTHER REDUCTION IN LEFT VENTRICLE END-DIASTOLIC PRESSURE AND TOTAL COLLAGEN AND AN INCREASE IN INTERLEUKIN-6 EXPRESSION. THE LOW ENGRAFTMENT OF INFUSED CELLS SUGGESTS THAT PARACRINE EFFECTS MIGHT ACCOUNT FOR THE BENEFICIAL EFFECTS OF C-KIT+ CELLS IN CHF. IN CONCLUSION, SELECTIVE INHIBITION OF CLASS I HDACS INDUCED EXPRESSION OF CARDIAC MARKERS IN C-KIT+ CELLS AND PARTIALLY AUGMENTED THE EFFICACY OF THESE CELLS FOR CHF REPAIR. SIGNIFICANCE: THE STUDY HAS SHOWN THAT SELECTIVE CLASS 1 HISTONE DEACETYLASE INHIBITION IS SUFFICIENT TO REDIRECT C-KIT+ CELLS TOWARD A CARDIAC FATE. EPIGENETICALLY MODIFIED C-KIT+ CELLS IMPROVED CONTRACTILE FUNCTION AND RETARDED REMODELING OF THE CONGESTIVE HEART FAILURE HEART. THIS STUDY PROVIDES NEW INSIGHTS INTO THE EFFICACY OF CARDIAC C-KIT+ CELLS IN THE ISCHEMIC HEART FAILURE MODEL. 2015 6 6037 35 THE CHD6 CHROMATIN REMODELER IS AN OXIDATIVE DNA DAMAGE RESPONSE FACTOR. CELL SURVIVAL AFTER OXIDATIVE DNA DAMAGE REQUIRES SIGNALING, REPAIR AND TRANSCRIPTIONAL EVENTS OFTEN ENABLED BY NUCLEOSOME DISPLACEMENT, EXCHANGE OR REMOVAL BY CHROMATIN REMODELING ENZYMES. HERE, WE SHOW THAT CHROMODOMAIN HELICASE DNA-BINDING PROTEIN 6 (CHD6), DISTINCT TO OTHER CHD ENZYMES, IS STABILIZED DURING OXIDATIVE STRESS VIA REDUCED DEGRADATION. CHD6 RELOCATES RAPIDLY TO DNA DAMAGE IN A MANNER DEPENDENT UPON OXIDATIVE LESIONS AND A CONSERVED N-TERMINAL POLY(ADP-RIBOSE)-DEPENDENT RECRUITMENT MOTIF, WITH LATER RETENTION REQUIRING THE DOUBLE CHROMODOMAIN AND CENTRAL CORE. CHD6 ABLATION INCREASES REACTIVE OXYGEN SPECIES PERSISTENCE AND IMPAIRS ANTI-OXIDANT TRANSCRIPTIONAL RESPONSES, LEADING TO ELEVATED DNA BREAKAGE AND POLY(ADP-RIBOSE) INDUCTION THAT CANNOT BE RESCUED BY CATALYTIC OR DOUBLE CHROMODOMAIN MUTANTS. DESPITE NO OVERT EPIGENETIC OR DNA REPAIR ABNORMALITIES, CHD6 LOSS LEADS TO IMPAIRED CELL SURVIVAL AFTER CHRONIC OXIDATIVE STRESS, ABNORMAL CHROMATIN RELAXATION, AMPLIFIED DNA DAMAGE SIGNALING AND CHECKPOINT HYPERSENSITIVITY. WE SUGGEST THAT CHD6 IS A KEY REGULATOR OF THE OXIDATIVE DNA DAMAGE RESPONSE. 2019 7 2326 29 EPIGENETIC REGULATION OF HOTAIR IN ADVANCED CHRONIC MYELOID LEUKEMIA. PURPOSE: CHRONIC MYELOID LEUKEMIA (CML) ACCOUNTS FOR ~10% OF LEUKEMIA CASES, AND ITS PROGRESSION INVOLVES EPIGENETIC GENE REGULATION. THIS STUDY INVESTIGATED EPIGENETIC REGULATION OF HOTAIR AND ITS TARGET MICRORNA, MIR-143, IN ADVANCED CML. PATIENTS AND METHODS: WE FIRST ISOLATED BONE MARROW MONONUCLEAR CELLS FROM 70 PATIENTS WITH DIFFERENT PHASES OF CML AND FROM HEALTHY DONORS AS NORMAL CONTROL; WE ALSO CULTURED K562 AND KCL22 CELLS, TREATED WITH DEMETHYLATION DRUG; MTT ASSAY, FLOW CYTOMETRY, QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QPCR), METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), WESTERN BLOT, LUCIFERASE ASSAY, RNA PULL-DOWN ASSAY AND RNA-BINDING PROTEIN IMMUNOPRECIPITATION (RIP) ASSAY WERE PERFORMED. RESULT: AS MEASURED BY QPCR, HOTAIR EXPRESSION IN K562 CELLS, KCL22 CELLS, AND SAMPLES FROM CASES OF ADVANCED-STAGE CML INCREASED WITH LEVELS OF SEVERAL DNA METHYLTRANSFERASES AND HISTONE DEACETYLATES, INCLUDING DNMT1, DNMT3A, HDAC1, EZH2, AND LSD1, AND MIR-143 LEVELS WERE DECREASED AND HOTAIR LEVELS WERE INCREASED. TREATMENT WITH 5-AZACYTIDINE, A DNA METHYLATION INHIBITOR, DECREASED DNMT1, DNMT3A, HDAC1, EZH2, LSD1 MRNA, PROTEIN LEVELS, AND HOTAIR MRNA LEVELS BUT INCREASED MIR-143 LEVELS. HOTAIR KNOCKDOWN AND MIR-143 OVEREXPRESSION BOTH INHIBITED PROLIFERATION AND PROMOTED APOPTOSIS IN KCL22 AND K562 CELLS THROUGH THE PI3K/AKT PATHWAY. RNA PULL-DOWN, MASS SPECTROMETRY, AND RIP ASSAYS SHOWED THAT HOTAIR INTERACTED WITH EZH2 AND LSD1. A DUAL-LUCIFERASE ASSAY DEMONSTRATED THAT HOTAIR INTERACTED WITH MIR-143. CONCLUSION: OUR FINDINGS DEMONSTRATE THE KEY EPIGENETIC INTERACTIONS OF HOTAIR RELATED TO CML PROGRESSION AND SUGGEST HOTAIR AS A POTENTIAL THERAPEUTIC TARGET FOR ADVANCED CML. FURTHERMORE, OUR RESULTS SUPPORT THE USE OF DEMETHYLATION DRUGS AS A CML TREATMENT STRATEGY. 2018 8 2969 90 GENETIC AND EPIGENETIC REGULATION OF THE INNATE IMMUNE RESPONSE TO GOUT. GOUT IS A DISEASE CAUSED BY URIC ACID (UA) ACCUMULATION IN THE JOINTS, CAUSING INFLAMMATION. TWO UA FORMS - MONOSODIUM URATE (MSU) AND SOLUBLE URIC ACID (SUA) HAVE BEEN SHOWN TO INTERACT PHYSICALLY WITH INFLAMMASOMES, ESPECIALLY WITH THE NOD-LIKE RECEPTOR (NLR) FAMILY PYRIN DOMAIN CONTAINING 3 (NLRP3), ALBEIT THE ROLE OF THE IMMUNE RESPONSE TO UA IS POORLY UNDERSTOOD, GIVEN THAT ASYMPTOMATIC HYPERURICEMIA DOES ALSO EXIST. MACROPHAGE PHAGOCYTOSIS OF UA ACTIVATE NLRP3, LEAD TO CYTOKINES RELEASE, AND ULTIMATELY, LEAD TO CHEMOATTRACT NEUTROPHILS AND LYMPHOCYTES TO THE GOUT FLARE JOINT SPOT. GENETIC VARIANTS OF INFLAMMASOME GENES AND OF GENES ENCODING THEIR MOLECULAR PARTNERS MAY INFLUENCE HYPERURICEMIA AND GOUT SUSCEPTIBILITY, WHILE ALSO INFLUENCING OTHER COMORBIDITIES SUCH AS METABOLIC SYNDROME AND CARDIOVASCULAR DISEASES. IN THIS REVIEW, WE SUMMARIZE THE INFLAMMATORY RESPONSES IN ACUTE AND CHRONIC GOUT, SPECIFICALLY FOCUSING ON INNATE IMMUNE CELL MECHANISMS AND GENETIC AND EPIGENETIC CHARACTERISTICS OF PARTICIPATING MOLECULES. UNPRECEDENTLY, A NOVEL UA BINDING PROTEIN - THE NEURONAL APOPTOSIS INHIBITOR PROTEIN (NAIP) - IS SUGGESTED AS RESPONSIBLE FOR THE ASYMPTOMATIC HYPERURICEMIA PARADOX.ABBREVIATION: BETA2-INTEGRINS: LEUKOCYTE-SPECIFIC ADHESION MOLECULES; ABCG2: ATP-BINDING CASSETE FAMILY/BREAST CANCER-RESISTANT PROTEIN; ACR: AMERICAN COLLEGE OF RHEUMATOLOGY; AIM2: ABSENT IN MELANOMA 2, TYPE OF PATTERN RECOGNITION RECEPTOR; ALPK1: ALPHA-PROTEIN KINASE 1; ANGPTL2: ANGIOPOIETIN-LIKE PROTEIN 2; ASC: APOPTOSIS-ASSOCIATED SPECK-LIKE PROTEIN; BIR: BACULOVIRUS INHIBITOR OF APOPTOSIS PROTEIN REPEAT; BIRC1: BACULOVIRUS IAP REPEAT-CONTAINING PROTEIN 1; BIRC2: BACULOVIRAL IAP REPEAT-CONTAINING PROTEIN 2; C5A: COMPLEMENT ANAPHYLATOXIN; CAMP: CYCLIC ADENOSINE MONOPHOSPHATE; CARD: CASPASE ACTIVATION AND RECRUITMENT DOMAINS; CARD8: CASPASE RECRUITMENT DOMAIN-CONTAINING PROTEIN 8; CASP1: CASPASE 1; CCL3: CHEMOKINE (C-C MOTIF) LIGAND 3; CD14: CLUSTER OF DIFFERENTIATION 14; CD44: CLUSTER OF DIFFERENTIATION 44; CG05102552: DNA-METHYLATION SITE, USUALLY CYTOSINE FOLLOWED BY GUANINE NUCLEOTIDES; CONTAINS ARBITRARY IDENTIFICATION CODE; CIDEC: CELL DEATH-INDUCING DNA FRAGMENTATION FACTOR-LIKE EFFECTOR FAMILY; CKD: CHRONIC KIDNEY DISEASE; CNV: COPY NUMBER VARIATION; CPT1A: CARNITINE PALMITOYL TRANSFERASE - TYPE 1A; CXCL1: CHEMOKINE (CXC MOTIF) LIGAND 1; DAMPS: DAMAGE ASSOCIATED MOLECULAR PATTERNS; DC: DENDRITIC CELLS; DNMT(1): MAINTENANCE DNA METHYLTRANSFERASE; EQTL: EXPRESSION QUANTITATIVE TRAIT LOCI; ERK1: EXTRACELLULAR SIGNAL-REGULATED KINASE 1; ERK2: EXTRACELLULAR SIGNAL-REGULATED KINASE 2; EULAR: EUROPEAN LEAGUE AGAINST RHEUMATISM; GMCSF: GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR; GWAS: GLOBAL WIDE ASSOCIATION STUDIES; H3K27ME3: TRI-METHYLATION AT THE 27TH LYSINE RESIDUE OF THE HISTONE H3 PROTEIN; H3K4ME1: MONO-METHYLATION AT THE 4TH LYSINE RESIDUE OF THE HISTONE H3 PROTEIN; H3K4ME3: TRI-METHYLATION AT THE 4TH LYSINE RESIDUE OF THE HISTONE H3 PROTEIN; HOTAIR: HUMAN GENE LOCATED BETWEEN HOXC11 AND HOXC12 ON CHROMOSOME 12; IKAPPABALPHA: CYTOPLASMATIC PROTEIN/NF-KAPPAB TRANSCRIPTION INHIBITOR; IAP: INHIBITORY APOPTOSIS PROTEIN; IFNGAMMA: INTERFERON GAMMA; IL-1BETA: INTERLEUKIN 1 BETA; IL-12: INTERLEUKIN 12; IL-17: INTERLEUKIN 17; IL18: INTERLEUKIN 18; IL1R1: INTERLEUKIN-1 RECEPTOR; IL-1RA: INTERLEUKIN-1 RECEPTOR ANTAGONIST; IL-22: INTERLEUKIN 22; IL-23: INTERLEUKIN 23; IL23R: INTERLEUKIN 23 RECEPTOR; IL-33: INTERLEUKIN 33; IL-6: INTERLEUKIN 6; IMP: INOSINE MONOPHOSPHATE; INSIG1: INSULIN-INDUCED GENE 1; JNK1: C-JUN N-TERMINAL KINASE 1; LNCRNA: LONG NON-CODING RIBONUCLEIC ACID; LRR: LEUCINE-RICH REPEATS; MIR: MATURE NON-CODING MICRORNAS MEASURING FROM 20 TO 24 NUCLEOTIDES, ANIMAL ORIGIN; MIR-1: MIR FOLLOWED BY ARBITRARY IDENTIFICATION CODE; MIR-145: MIR FOLLOWED BY ARBITRARY IDENTIFICATION CODE; MIR-146A: MIR FOLLOWED BY ARBITRARY IDENTIFICATION CODE, "A" STANDS FOR MIR FAMILY; "A" FAMILY PRESENTS SIMILAR MIR SEQUENCE TO "B" FAMILY, BUT DIFFERENT PRECURSORS; MIR-20B: MIR FOLLOWED BY ARBITRARY IDENTIFICATION CODE; "B" STANDS FOR MIR FAMILY; "B" FAMILY PRESENTS SIMILAR MIR SEQUENCE TO "A" FAMILY, BUT DIFFERENT PRECURSORS; MIR-221: MIR - FOLLOWED BY ARBITRARY IDENTIFICATION CODE; MIR-221-5P: MIR FOLLOWED BY ARBITRARY IDENTIFICATION CODE; "5P" INDICATES DIFFERENT MATURE MIRNAS GENERATED FROM THE 5' ARM OF THE PRE-MIRNA HAIRPIN; MIR-223: MIR FOLLOWED BY ARBITRARY IDENTIFICATION CODE; MIR-223-3P: MIR FOLLOWED BY ARBITRARY IDENTIFICATION CODE; "3P" INDICATES DIFFERENT MATURE MIRNAS GENERATED FROM THE 3' ARM OF THE PRE-MIRNA HAIRPIN; MIR-22-3P: MIR FOLLOWED BY ARBITRARY IDENTIFICATION CODE, "3P" INDICATES DIFFERENT MATURE MIRNAS GENERATED FROM THE 3' ARM OF THE PRE-MIRNA HAIRPIN; MLKL: MIXED LINEAGE KINASE DOMAIN-LIKE PSEUDO KINASE; MM2P: INDUCTOR OF M2-MACROPHAGE POLARIZATION; MSU: MONOSODIUM URATE; MTOR: MAMMALIAN TARGET OF RAPAMYCIN; MYD88: MYELOID DIFFERENTIATION PRIMARY RESPONSE 88; N-3-PUFAS: N-3-POLYUNSATURATED FATTY-ACIDS; NACHT: ACRONYM FOR NAIP (NEURONAL APOPTOSIS INHIBITOR PROTEIN), C2TA (MHC CLASS 2 TRANSCRIPTION ACTIVATOR), HET-E (INCOMPATIBILITY LOCUS PROTEIN FROM PODOSPORA ANSERINA) AND TP1 (TELOMERASE-ASSOCIATED PROTEIN); NAIP: NEURONAL APOPTOSIS INHIBITORY PROTEIN (HUMAN); NAIP1: NEURONAL APOPTOSIS INHIBITORY PROTEIN TYPE 1 (MURINE); NAIP5: NEURONAL APOPTOSIS INHIBITORY PROTEIN TYPE 5 (MURINE); NAIP6: NEURONAL APOPTOSIS INHIBITORY PROTEIN TYPE 6 (MURINE); NBD: NUCLEOTIDE-BINDING DOMAIN; NEK7: SMALLEST NIMA-RELATED KINASE; NET: NEUTROPHIL EXTRACELLULAR TRAPS; NF-KAPPAB: NUCLEAR FACTOR KAPPA-LIGHT-CHAIN-ENHANCER OF ACTIVATED B CELLS; NFIL3: NUCLEAR-FACTOR, INTERLEUKIN 3 REGULATED PROTEIN; NIIMA: NETWORK OF IMMUNITY IN INFECTION, MALIGNANCY, AND AUTOIMMUNITY; NLR: NOD-LIKE RECEPTOR; NLRA: NOD-LIKE RECEPTOR NLRA CONTAINING ACIDIC DOMAIN; NLRB: NOD-LIKE RECEPTOR NLRA CONTAINING BIR DOMAIN; NLRC: NOD-LIKE RECEPTOR NLRA CONTAINING CARD DOMAIN; NLRC4: NOD-LIKE RECEPTOR FAMILY CARD DOMAIN CONTAINING 4; NLRP: NOD-LIKE RECEPTOR NLRA CONTAINING PYD DOMAIN; NLRP1: NUCLEOTIDE-BINDING OLIGOMERIZATION DOMAIN, LEUCINE-RICH REPEAT, AND PYRIN DOMAIN CONTAINING 1; NLRP12: NUCLEOTIDE-BINDING OLIGOMERIZATION DOMAIN, LEUCINE-RICH REPEAT, AND PYRIN DOMAIN CONTAINING 12; NLRP3: NOD-LIKE RECEPTOR FAMILY PYRIN DOMAIN CONTAINING 3; NOD2: NUCLEOTIDE-BINDING OLIGOMERIZATION DOMAIN; NRBP1: NUCLEAR RECEPTOR-BINDING PROTEIN; NRF2: NUCLEAR FACTOR ERYTHROID 2-RELATED FACTOR 2; OR: ODDS RATIO; P2X: GROUP OF MEMBRANE ION CHANNELS ACTIVATED BY THE BINDING OF EXTRACELLULAR; P2X7: P2X PURINOCEPTOR 7 GENE; P38: MEMBER OF THE MITOGEN-ACTIVATED PROTEIN KINASE FAMILY; PAMPS: PATHOGEN ASSOCIATED MOLECULAR PATTERS; PBMC: PERIPHERAL BLOOD MONONUCLEAR CELLS; PGGT1B: GERANYLGERANYL TRANSFERASE TYPE-1 SUBUNIT BETA; PHGDH: PHOSPHOGLYCERATE DEHYDROGENASE; PI3-K: PHOSPHO-INOSITOL; PPARGAMMA: PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA; PPARGC1B: PEROXISOME PROLIFERATIVE ACTIVATED RECEPTOR, GAMMA, COACTIVATOR 1 BETA; PR3: PROTEINASE 3 ANTIGEN; PRO-CASP1: INACTIVE PRECURSOR OF CASPASE 1; PRO-IL1BETA: INACTIVE PRECURSOR OF INTERLEUKIN 1 BETA; PRR: PATTERN RECOGNITION RECEPTORS; PYD: PYRIN DOMAIN; RAPTOR: REGULATORY ASSOCIATED PROTEIN OF MTOR COMPLEX 1; RAS: RENIN-ANGIOTENSIN SYSTEM; REDD1: REGULATED IN DNA DAMAGE AND DEVELOPMENT 1; ROS: REACTIVE OXYGEN SPECIES; RS000*G: SINGLE NUCLEAR POLYMORPHISM, "*G" IS RELATED TO SNP WHERE REPLACED NUCLEOTIDE IS GUANINE, USUALLY PRECEDED BY AN ID NUMBER; SLC2A9: SOLUTE CARRIER FAMILY 2, MEMBER 9; SLC7A11: SOLUTE CARRIER FAMILY 7, MEMBER 11; SMA: SMOOTH MUSCULAR ATROPHY; SMAC: SECOND MITOCHONDRIAL-DERIVED ACTIVATOR OF CASPASES; SNP: SINGLE NUCLEAR POLYMORPHISM; SP3: SPECIFICITY PROTEIN 3; ST2: SERUM STIMULATION-2; STK11: SERINE/THREONINE KINASE 11; SUA: SOLUBLE URIC ACID; SYK: SPLEEN TYROSINE KINASE; TAK1: TRANSFORMING GROWTH FACTOR BETA ACTIVATED KINASE; TH1: TYPE 1 HELPER T CELLS; TH17: TYPE 17 HELPER T CELLS; TH2: TYPE 2 HELPER T CELLS; TH22: TYPE 22 HELPER T CELLS; TLR: TOOL-LIKE RECEPTOR; TLR2: TOLL-LIKE RECEPTOR 2; TLR4: TOLL-LIKE RECEPTOR 4; TNFALPHA: TUMOR NECROSIS FACTOR ALPHA; TNFR1: TUMOR NECROSIS FACTOR RECEPTOR 1; TNFR2: TUMOR NECROSIS FACTOR RECEPTOR 2; UA: URIC ACID; UBAP1: UBIQUITIN ASSOCIATED PROTEIN; ULT: URATE-LOWERING THERAPY; URAT1: URATE TRANSPORTER 1; VDAC1: VOLTAGE-DEPENDENT ANION-SELECTIVE CHANNEL 1. 2023 9 3389 40 HOMOCYSTEINE SUPPRESSES THE EXPRESSION OF THE COLLAGEN CROSS-LINKER LYSYL OXIDASE INVOLVING IL-6, FLI1, AND EPIGENETIC DNA METHYLATION. ELEVATED HOMOCYSTEINE (HCYS) SERUM LEVELS REPRESENT A RISK FACTOR FOR SEVERAL CHRONIC PATHOLOGIES, INCLUDING CARDIOVASCULAR DISEASE, ATHEROSCLEROSIS, AND CHRONIC RENAL FAILURE, AND AFFECT BONE DEVELOPMENT, QUALITY, AND HOMEOSTASIS. HCYS INFLUENCES THE FORMATION OF A STABLE BONE MATRIX DIRECTLY THROUGH THE INHIBITION OF THE COLLAGEN CROSS-LINKING ENZYME LYSYL OXIDASE (LOX) AND, AS WE HAVE SHOWN RECENTLY, BY REPRESSING ITS MRNA EXPRESSION. THE AIM OF THIS STUDY WAS TO INVESTIGATE THE MECHANISMS INVOLVED IN THIS PROCESS. THROUGH EVALUATION OF GENE ARRAYS, QUANTITATIVE RT-PCR, IMMUNOBLOTS, AND ELISA, WE IDENTIFIED A HCYS-DEPENDENT STIMULATION OF INTERLEUKIN 6 (IL-6) AND GENES INVOLVED IN IL-6/JANUS KINASE 2 (JAK2)-DEPENDENT SIGNAL TRANSDUCTION PATHWAYS IN PRE-OSTEOBLASTIC MC3T3-E1 CELLS. MOREOVER, UP-REGULATION OF GENES ESSENTIAL FOR EPIGENETIC DNA METHYLATION (DNA (CYTOSINE-5)-METHYLTRANSFERASES AND HELICASE LYMPHOID-SPECIFIC (HELLS) WAS OBSERVED. FURTHER INVESTIGATIONS DEMONSTRATED THAT HCYS INCREASED VIA IL-6/JAK2 THE EXPRESSION OF FLI1 (FRIEND LEUKEMIA VIRUS INTEGRATION 1), A TRANSCRIPTION FACTOR, WHICH WE FOUND ESSENTIAL FOR IL-6-DEPENDENT DNMT1 STIMULATION. CPG METHYLATION ANALYSIS OF CPG-RICH LOX PROXIMAL PROMOTER REVEALED AN INCREASED CPG METHYLATION STATUS AFTER TREATMENT OF THE CELLS WITH HCYS INDICATING AN EPIGENETIC ORIGIN FOR HCYS-DEPENDENT LOX REPRESSION. INHIBITION OF THE IL-6/JAK2 PATHWAY OR OF CPG METHYLATION REVERSED THE REPRESSIVE EFFECT OF HCYS ON LOX EXPRESSION. IN CONCLUSION, WE DEMONSTRATE THAT HCYS STIMULATES IL-6 SYNTHESIS IN OSTEOBLASTS, WHICH IS KNOWN TO AFFECT BONE METABOLISM VIA OSTEOCLASTS. FURTHERMORE, IL-6 STIMULATION RESULTS VIA JAK2, FLI1, AND DNMT1 IN DOWN-REGULATION OF LOX EXPRESSION BY EPIGENETIC CPG METHYLATION REVEALING A NEW MECHANISM NEGATIVELY AFFECTING BONE MATRIX FORMATION. 2011 10 1141 32 CONCERTED CELL AND IN VIVO SCREEN FOR PANCREATIC DUCTAL ADENOCARCINOMA (PDA) CHEMOTHERAPEUTICS. PDA IS A MAJOR CAUSE OF US CANCER-RELATED DEATHS. ONCOGENIC KRAS PRESENTS IN 90% OF HUMAN PDAS. KRAS MUTATIONS OCCUR EARLY IN PRE-NEOPLASTIC LESIONS BUT ARE INSUFFICIENT TO CAUSE PDA. OTHER CONTRIBUTING FACTORS EARLY IN DISEASE PROGRESSION INCLUDE CHRONIC PANCREATITIS, ALTERATIONS IN EPIGENETIC REGULATORS, AND TUMOR SUPPRESSOR GENE MUTATION. GPCRS ACTIVATE HETEROTRIMERIC G-PROTEINS THAT STIMULATE INTRACELLULAR CALCIUM AND ONCOGENIC KRAS SIGNALING, THEREBY PROMOTING PANCREATITIS AND PROGRESSION TO PDA. BY CONTRAST, RGS PROTEINS INHIBIT GI/Q-COUPLED GPCRS TO NEGATIVELY REGULATE PDA PROGRESSION. RGS16::GFP IS EXPRESSED IN RESPONSE TO CAERULEIN-INDUCED ACINAR CELL DEDIFFERENTIATION, EARLY NEOPLASIA, AND THROUGHOUT PDA PROGRESSION. IN GENETICALLY ENGINEERED MOUSE MODELS OF PDA, RGS16::GFP IS USEFUL FOR PRE-CLINICAL RAPID IN VIVO VALIDATION OF NOVEL CHEMOTHERAPEUTICS TARGETING EARLY LESIONS IN PATIENTS FOLLOWING SUCCESSFUL RESECTION OR AT HIGH RISK FOR PROGRESSING TO PDA. CULTURED PRIMARY PDA CELLS EXPRESS RGS16::GFP IN RESPONSE TO CYTOTOXIC DRUGS. A HISTONE DEACETYLASE INHIBITOR, TSA, STIMULATED RGS16::GFP EXPRESSION IN PDA PRIMARY CELLS, POTENTIATED GEMCITABINE AND JQ1 CYTOTOXICITY IN CELL CULTURE, AND GEM + TSA + JQ1 INHIBITED TUMOR INITIATION AND PROGRESSION IN VIVO. HERE WE ESTABLISH THE USE OF RGS16::GFP EXPRESSION FOR TESTING DRUG COMBINATIONS IN CELL CULTURE AND VALIDATION OF BEST CANDIDATES IN OUR RAPID IN VIVO SCREEN. 2020 11 5715 50 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 12 1093 21 COHESIN RAD21 GENE PROMOTER METHYLATION IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS THE MOST COMMON TYPE OF LEUKEMIA IN ADULTS AND IS CHARACTERIZED BY THE PRESENCE OF SPECIFIC CYTOGENETIC ABNORMALITIES. CLL RESEARCH HAS BEEN FOCUSED ON EPIGENETIC PROCESSES LIKE GENE PROMOTER METHYLATION OF CPG ISLANDS. IN THE PRESENT STUDY, THE METHYLATION STATUS OF THE RAD21 GENE IS STUDIED AND ASSOCIATED WITH CYTOGENETIC FINDINGS IN CLL PATIENTS IN ORDER TO INVESTIGATE ITS POSSIBLE IMPLICATION IN CLL PATHOGENESIS AND THE FORMATION OF CLL CHROMOSOMAL ABNORMALITIES. 2018 13 692 37 BRD4 PROMOTES HEPATIC STELLATE CELLS ACTIVATION AND HEPATIC FIBROSIS VIA MEDIATING P300/H3K27AC/PLK1 AXIS. HEPATIC FIBROSIS (HF) IS A REVERSIBLE WOUND-HEALING RESPONSE CHARACTERIZED BY EXCESSIVE EXTRACELLULAR MATRIX (ECM) DEPOSITION AND SECONDARY TO PERSISTENT CHRONIC INJURY. BROMODOMAIN PROTEIN 4 (BRD4) COMMONLY FUNCTIONS AS A "READER" TO REGULATE EPIGENETIC MODIFICATIONS INVOLVED IN VARIOUS BIOLOGICAL AND PATHOLOGICAL EVENTS, BUT THE MECHANISM OF HF REMAINS UNCLEAR. IN THIS STUDY, WE ESTABLISHED A CCL(4)-INDUCED HF MODEL AND SPONTANEOUS RECOVERY MODEL IN MICE AND FOUND ABERRANT BRD4 EXPRESSION, WHICH WAS CONSISTENT WITH THE RESULTS IN HUMAN HEPATIC STELLATE CELLS (HSCS)- LX2 CELLS IN VITRO. SUBSEQUENTLY, WE FOUND THAT DISTRICTION AND INHIBITION OF BRD4 RESTRAINED TGFBETA-INDUCED TRANS-DIFFERENTIATION OF LX2 CELLS INTO ACTIVATED, PROLIFERATIVE MYOFIBROBLASTS AND ACCELERATED APOPTOSIS, AND BRD4 OVEREXPRESSION BLOCKED MDI-INDUCED LX2 CELLS INACTIVATION AND PROMOTED THE PROLIFERATION AND INHIBITED APOPTOSIS OF INACTIVATED CELLS. ADDITIONALLY, ADENO-ASSOCIATED VIRUS SEROTYPE 8-LOADED SHORT HAIRPIN RNA-MEDIATED BRD4 KNOCKDOWN IN MICE SIGNIFICANTLY ATTENUATED CCL(4)-INDUCED FIBROTIC RESPONSES INCLUDING HSCS ACTIVATION AND COLLAGEN DEPOSITION. MECHANISTICALLY, BRD4 DEFICIENCY INHIBITED PLK1 EXPRESSION IN ACTIVATED LX2 CELLS, AND CHIP AND CO-IP ASSAYS REVEALED THAT BRD4 REGULATION OF PLK1 WAS DEPENDENT ON P300-MEDIATED ACETYLATION MODIFICATION FOR H3K27 ON THE PLK1 PROMOTER. IN CONCLUSION, BRD4 DEFICIENCY IN THE LIVER ALLEVIATES CCL(4)-INDUCED HF IN MICE, AND BRD4 PARTICIPATES IN THE ACTIVATION AND REVERSAL OF HSCS THROUGH POSITIVELY REGULATING THE P300/H3K27AC/PLK1 AXIS, PROVIDING A POTENTIAL INSIGHT FOR HF THERAPY. 2023 14 3064 39 GENOME-WIDE DNA METHYLATION ENCODES CARDIAC TRANSCRIPTIONAL REPROGRAMMING IN HUMAN ISCHEMIC HEART FAILURE. ISCHEMIC CARDIOMYOPATHY (ICM) IS THE CLINICAL ENDPOINT OF CORONARY HEART DISEASE AND A LEADING CAUSE OF HEART FAILURE. DESPITE GROWING DEMANDS TO DEVELOP PERSONALIZED APPROACHES TO TREAT ICM, PROGRESS IS LIMITED BY INADEQUATE KNOWLEDGE OF ITS PATHOGENESIS. SINCE EPIGENETICS HAS BEEN IMPLICATED IN THE DEVELOPMENT OF OTHER CHRONIC DISEASES, THE CURRENT STUDY WAS DESIGNED TO DETERMINE WHETHER TRANSCRIPTIONAL AND/OR EPIGENETIC CHANGES ARE SUFFICIENT TO DISTINGUISH ICM FROM OTHER ETIOLOGIES OF HEART FAILURE. SPECIFICALLY, WE HYPOTHESIZE THAT GENOME-WIDE DNA METHYLATION ENCODES TRANSCRIPTIONAL REPROGRAMMING IN ICM. RNA-SEQUENCING ANALYSIS WAS PERFORMED ON HUMAN ISCHEMIC LEFT VENTRICULAR TISSUE OBTAINED FROM PATIENTS WITH END-STAGE HEART FAILURE, WHICH ENRICHED KNOWN TARGETS OF THE POLYCOMB METHYLTRANSFERASE EZH2 COMPARED TO NON-ISCHEMIC HEARTS. COMBINED RNA SEQUENCING AND GENOME-WIDE DNA METHYLATION ANALYSIS REVEALED A ROBUST GENE EXPRESSION PATTERN CONSISTENT WITH SUPPRESSION OF OXIDATIVE METABOLISM, INDUCED ANAEROBIC GLYCOLYSIS, AND ALTERED CELLULAR REMODELING. LASTLY, KLF15 WAS IDENTIFIED AS A PUTATIVE UPSTREAM REGULATOR OF METABOLIC GENE EXPRESSION THAT WAS ITSELF REGULATED BY EZH2 IN A SET DOMAIN-DEPENDENT MANNER. OUR OBSERVATIONS THEREFORE DEFINE A NOVEL ROLE OF DNA METHYLATION IN THE METABOLIC REPROGRAMMING OF ICM. FURTHERMORE, WE IDENTIFY EZH2 AS AN EPIGENETIC REGULATOR OF KLF15 ALONG WITH DNA HYPERMETHYLATION, AND WE PROPOSE A NOVEL MECHANISM THROUGH WHICH CORONARY HEART DISEASE REPROGRAMS THE EXPRESSION OF BOTH INTERMEDIATE ENZYMES AND UPSTREAM REGULATORS OF CARDIAC METABOLISM SUCH AS KLF15. 2019 15 3205 44 HDAC8, A POTENTIAL THERAPEUTIC TARGET, REGULATES PROLIFERATION AND DIFFERENTIATION OF BONE MARROW STROMAL CELLS IN FIBROUS DYSPLASIA. FIBROUS DYSPLASIA (FD) IS A DISEASE OF POSTNATAL SKELETAL STEM CELLS CAUSED BY ACTIVATING MUTATIONS OF GUANINE NUCLEOTIDE-BINDING PROTEIN ALPHA-STIMULATING ACTIVITY POLYPEPTIDE (GNAS). FD IS CHARACTERIZED BY HIGH PROLIFERATION AND OSTEOGENESIS DISORDER OF BONE MARROW STROMAL CELLS (BMSCS), RESULTING IN BONE PAIN, DEFORMITIES, AND FRACTURES. THE CAMP-CREB PATHWAY, WHICH IS ACTIVATED BY GNAS MUTATIONS, IS KNOWN TO BE CLOSELY ASSOCIATED WITH THE OCCURRENCE OF FD. HOWEVER, SO FAR THERE IS NO AVAILABLE TARGETED THERAPEUTIC STRATEGY FOR FD, AS A CRITICAL ISSUE THAT REMAINS LARGELY UNKNOWN IS HOW THIS PATHWAY IS INVOLVED IN FD. OUR PREVIOUS STUDY REVEALED THAT HISTONE DEACETYLASE 8 (HDAC8) INHIBITED THE OSTEOGENIC DIFFERENTIATION OF BMSCS VIA EPIGENETIC REGULATION. HERE, COMPARED WITH NORMAL BMSCS, FD BMSCS EXHIBITED SIGNIFICANTLY HIGH PROLIFERATION AND WEAK OSTEOGENIC CAPACITY IN RESPONSE TO HDAC8 UPREGULATION AND TUMOR PROTEIN 53 (TP53) DOWNREGULATION. MOREOVER, INHIBITION OF CAMP REDUCED HDAC8 EXPRESSION, INCREASED TP53 EXPRESSION AND RESULTED IN THE IMPROVEMENT OF FD PHENOTYPE. IMPORTANTLY, HDAC8 INHIBITION PREVENTED CAMP-INDUCED CELL PHENOTYPE AND PROMOTED OSTEOGENESIS IN NUDE MICE THAT WERE IMPLANTED WITH FD BMSCS. MECHANISTICALLY, HDAC8 WAS IDENTIFIED AS A TRANSCRIPTIONAL TARGET GENE OF CREB1 AND ITS TRANSCRIPTION WAS DIRECTLY ACTIVATED BY CREB1 IN FD BMSCS. IN SUMMARY, OUR STUDY REVEALS THAT HDAC8 ASSOCIATES WITH FD PHENOTYPE AND DEMONSTRATES THE MECHANISMS REGULATED BY CAMP-CREB1-HDAC8 PATHWAY. THESE RESULTS PROVIDE INSIGHTS INTO THE MOLECULAR REGULATION OF FD PATHOGENESIS, AND OFFER NOVEL CLUES THAT SMALL MOLECULE INHIBITORS TARGETING HDAC8 ARE PROMISING CLINICAL TREATMENT FOR FD. STEM CELLS TRANSLATIONAL MEDICINE 2019;8:148&14. 2019 16 598 26 BETA-ADRENERGIC SIGNALING PROMOTES TUMOR ANGIOGENESIS AND PROSTATE CANCER PROGRESSION THROUGH HDAC2-MEDIATED SUPPRESSION OF THROMBOSPONDIN-1. CHRONIC BEHAVIORAL STRESS AND BETA-ADRENERGIC SIGNALING HAVE BEEN SHOWN TO PROMOTE CANCER PROGRESSION, WHOSE UNDERLYING MECHANISMS ARE LARGELY UNCLEAR, ESPECIALLY THE INVOLVEMENT OF EPIGENETIC REGULATION. HISTONE DEACETYLASE-2 (HDAC2), AN EPIGENETIC REGULATOR, IS CRITICAL FOR STRESS-INDUCED CARDIAC HYPERTROPHY. IT IS UNKNOWN WHETHER IT IS NECESSARY FOR BETA-ADRENERGIC SIGNALING-PROMOTED CANCER PROGRESSION. USING XENOGRAFT MODELS, WE SHOWED THAT CHRONIC BEHAVIORAL STRESS AND BETA-ADRENERGIC SIGNALING PROMOTE ANGIOGENESIS AND PROSTATE CANCER PROGRESSION. HDAC2 WAS INDUCED BY BETA-ADRENERGIC SIGNALING IN VITRO AND IN MOUSE XENOGRAFTS. WE NEXT UNCOVERED THAT HDAC2 IS A DIRECT TARGET OF CAMP RESPONSE ELEMENT-BINDING PROTEIN (CREB) THAT IS ACTIVATED BY BETA-ADRENERGIC SIGNALING. NOTABLY, HDAC2 IS NECESSARY FOR BETA-ADRENERGIC SIGNALING TO INDUCE ANGIOGENESIS. WE FURTHER DEMONSTRATED THAT, UPON CREB ACTIVATION, HDAC2 REPRESSES THROMBOSPONDIN-1 (TSP1), A POTENT ANGIOGENESIS INHIBITOR, THROUGH EPIGENETIC REGULATION. TOGETHER, THESE DATA ESTABLISH A NOVEL PATHWAY THAT HDAC2 AND TSP1 ACT DOWNSTREAM OF CREB ACTIVATION IN BETA-ADRENERGIC SIGNALING TO PROMOTE CANCER PROGRESSION. 2017 17 1646 27 DOES THE HEPATITIS B ANTIGEN HBX PROMOTE THE APPEARANCE OF LIVER CANCER STEM CELLS? HEPATITIS B VIRUS (HBV) IS A MAJOR ETIOLOGIC AGENT OF CHRONIC LIVER DISEASE AND HEPATOCELLULAR CARCINOMA (HCC). HBV-ENCODED X ANTIGEN, HBX, AND PATHWAYS IMPLICATED IN THE SELF-RENEWAL OF STEM CELLS CONTRIBUTE TO HCC, BUT IT IS NOT CLEAR WHETHER HBX EXPRESSION PROMOTES "STEMNESS." THUS, EXPERIMENTS WERE DESIGNED TO TEST THE HYPOTHESIS THAT HBX TRIGGERS MALIGNANT TRANSFORMATION BY PROMOTING PROPERTIES THAT ARE CHARACTERISTIC OF CANCER STEM CELLS (CSC). TO TEST THIS HYPOTHESIS, HEPG2 CELLS WERE STABLY TRANSDUCED WITH HBX AND THEN ASSAYED FOR PHENOTYPIC AND MOLECULAR CHARACTERISTICS OF "STEMNESS." THE RELATIONSHIP BETWEEN HBX AND "STEMNESS"-ASSOCIATED MARKERS WAS ALSO EVALUATED BY IMMUNOHISTOCHEMICAL STAINING OF LIVER AND TUMOR TISSUE SECTIONS FROM HBV-INFECTED PATIENTS. THE RESULTS SHOWED THAT OCT-4, NANOG, KLF-4, BETA-CATENIN, AND EPITHELIAL CELL ADHESION MOLECULE (EPCAM) WERE ACTIVATED BY HBX IN VITRO AND IN VIVO. EPCAM WAS DETECTED IN THE NUCLEI OF HUMAN HCC CELLS FROM INFECTED PATIENTS. HBX PROMOTES "STEMNESS" BY ACTIVATING BETA-CATENIN AND EPIGENETIC UPREGULATION OF MIR-181, BOTH OF WHICH TARGET EPCAM. HBX EXPRESSION WAS ALSO ASSOCIATED WITH DEPRESSED LEVELS OF E-CADHERIN. MOREOVER, HBX STIMULATED CELL MIGRATION, GROWTH IN SOFT AGAR, AND SPHEROID FORMATION. THIS WORK IS THE FIRST TO PROPOSE THAT HBV PROMOTES "STEMNESS" IN THE PATHOGENESIS OF HCC. HBX-ASSOCIATED UPREGULATED EXPRESSION OF MULTIPLE "STEMNESS" MARKERS SUPPORTS THE HYPOTHESIS THAT HBX CONTRIBUTES TO HEPATOCARCINOGENESIS, AT LEAST IN PART, BY PROMOTING CHANGES IN GENE EXPRESSION THAT ARE CHARACTERISTICS OF CSCS. 2011 18 3189 38 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 19 6540 33 TRANSCRIPTIONAL, EPIGENETIC, AND FUNCTIONAL REPROGRAMMING OF MONOCYTES FROM NON-HUMAN PRIMATES FOLLOWING CHRONIC ALCOHOL DRINKING. CHRONIC HEAVY DRINKING (CHD) OF ALCOHOL IS A KNOWN RISK FACTOR FOR INCREASED SUSCEPTIBILITY TO BACTERIAL AND VIRAL INFECTION AS WELL AS IMPAIRED WOUND HEALING. EVIDENCE SUGGESTS THAT THESE DEFECTS ARE MEDIATED BY A DYSREGULATED INFLAMMATORY RESPONSE ORIGINATING FROM MYELOID CELLS, NOTABLY MONOCYTES AND MACROPHAGES, BUT THE MECHANISMS REMAIN POORLY UNDERSTOOD. OUR ABILITY TO STUDY CHD IS IMPACTED BY THE COMPLEXITIES OF HUMAN DRINKING PATTERNS AND BEHAVIOR AS WELL AS COMORBIDITIES AND CONFOUNDING RISK FACTORS FOR PATIENTS WITH ALCOHOL USE DISORDERS. TO OVERCOME THESE CHALLENGES, WE UTILIZED A TRANSLATIONAL RHESUS MACAQUE MODEL OF VOLUNTARY ETHANOL SELF-ADMINISTRATION THAT CLOSELY RECAPITULATES HUMAN DRINKING PATTERNS AND CHRONICITY. IN THIS STUDY, WE EXAMINED THE EFFECTS OF CHD ON BLOOD MONOCYTES IN CONTROL AND CHD FEMALE MACAQUES AFTER 12 MONTHS OF DAILY ETHANOL CONSUMPTION. WHILE MONOCYTES FROM CHD FEMALE MACAQUES GENERATED A HYPER-INFLAMMATORY RESPONSE TO EX VIVO LPS STIMULATION, THEIR RESPONSE TO E. COLI WAS DAMPENED. IN DEPTH SCRNA-SEQ ANALYSIS OF PURIFIED MONOCYTES REVEALED SIGNIFICANT SHIFTS IN CLASSICAL MONOCYTE SUBSETS WITH ACCUMULATION OF CELLS EXPRESSING MARKERS OF HYPOXIA (HIF1A) AND INFLAMMATION (NFKB SIGNALING PATHWAY) IN CHD MACAQUES. THE INCREASED PRESENCE OF MONOCYTE SUBSETS SKEWED TOWARDS INFLAMMATORY PHENOTYPES WAS COMPLEMENTED BY EPIGENETIC ANALYSIS, WHICH REVEALED HIGHER ACCESSIBILITY OF PROMOTER REGIONS THAT REGULATE GENES INVOLVED IN CYTOKINE SIGNALING PATHWAYS. COLLECTIVELY, DATA PRESENTED IN THIS MANUSCRIPT DEMONSTRATE THAT CHD SHIFTS CLASSICAL MONOCYTE SUBSET COMPOSITION AND PRIMES THE MONOCYTES TOWARDS A MORE HYPER-INFLAMMATORY RESPONSE TO LPS, BUT COMPROMISED PATHOGEN RESPONSE. 2021 20 1906 37 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