1 4747 145 NOVEL MODULATORS OF HEPATOSTEATOSIS, INFLAMMATION AND FIBROGENESIS. ALCOHOLIC STEATOSIS, INSTEAD OF BEING INNOCUOUS, PLAYS A CRITICAL ROLE IN LIVER INFLAMMATION AND FIBROGENESIS. THE SEVERITY OF FATTY LIVER IS GOVERNED BY THE CONCERTED BALANCE BETWEEN LIPID TRANSPORT, SYNTHESIS, AND DEGRADATION. WHEREAS SCAVENGER RECEPTOR CLASS B, TYPE I (SR-B1) IS CRITICAL FOR REVERSE CHOLESTEROL UPTAKE BY THE LIVER, PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPARGAMMA) COACTIVATOR-1ALPHA AND -BETA (PGC1ALPHA AND PGC1BETA) ARE CRITICAL FOR LIPID DEGRADATION AND SYNTHESIS, RESPECTIVELY. BECAUSE BETAINE IS A LIPOTROPIC AGENT, WE HAVE EVALUATED ITS EFFECTS ON ALCOHOLIC STEATOSIS. BETAINE EFFECTIVELY PREVENTED CHRONIC ALCOHOL-MEDIATED (I) IMPAIRED SR-B1 GLYCOSYLATION, PLASMA MEMBRANE LOCALIZATION, AND CONSEQUENT IMPAIRED CHOLESTEROL TRANSPORT; AND (II) UP REGULATION OF PGC-1BETA, STEROL REGULATORY ELEMENT-BINDING PROTEIN 1C AND DOWNSTREAM LIPOGENIC GENES WITH CONCOMITANT INCREASED LIVER CHOLESTEROL, TRIGLYCERIDES AND HEPATIC LIPID SCORE. SIMILARLY, BECAUSE OF ITS ANTI-INFLAMMATORY AND ANTI-FIBROTIC EFFECTS IN OTHER ORGANS, WE EVALUATED THE PROTECTIVE EFFECTS OF THYMOSIN BETA4 (TBETA4) AGAINST CARBON TETRACHLORIDE (CCL4)-INDUCED HEPATOTOXICITY IN RAT. TBETA4 PREVENTED CCL4-INDUCED (I) NECROSIS, INFLAMMATORY INFILTRATION AND UP-REGULATION OF ALPHA1(2)COLLAGEN, ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA), PLATELET DERIVED GROWTH FACTOR BETA (PDGF-BETA) RECEPTOR AND FIBRONECTIN MRNA EXPRESSION; (II) DOWN-REGULATION OF ADIPOGENIC GENE, PPARGAMMA AND THE UP-REGULATION OF EPIGENETIC REPRESSOR GENE, METHYL CPG BINDING PROTEIN 2 (MECP2) MRNA LEVELS, SUGGESTING THAT THE ANTI-FIBROGENIC ACTIONS OF TBETA4 INVOLVE THE PREVENTION OF TRANS-DIFFERENTIATION OF QUIESCENT HEPATIC STELLATE CELLS INTO MYO-FIBROBLASTS LARGELY BY UP-REGULATING PPARGAMMA AND BY DOWN-REGULATING MECP2 GENES. WE THEREFORE CONCLUDE THAT BETAINE AND TBETA4 CAN EFFECTIVELY PROTECT AGAINST ALCOHOLIC HEPATOSTEATOSIS AND HEPATIC FIBROGENESIS, RESPECTIVELY. 2014 2 6456 40 THYMOSIN BETA4 PREVENTS OXIDATIVE STRESS, INFLAMMATION, AND FIBROSIS IN ETHANOL- AND LPS-INDUCED LIVER INJURY IN MICE. THYMOSIN BETA 4 (TBETA4), AN ACTIN-SEQUESTERING PROTEIN, IS INVOLVED IN TISSUE DEVELOPMENT AND REGENERATION. IT PREVENTS INFLAMMATION AND FIBROSIS IN SEVERAL TISSUES. WE INVESTIGATED THE ROLE OF TBETA4 IN CHRONIC ETHANOL- AND ACUTE LIPOPOLYSACCHARIDE- (LPS-) INDUCED MOUSE LIVER INJURY. C57BL/6 MICE WERE FED 5% ETHANOL IN LIQUID DIET FOR 4 WEEKS PLUS BINGE ETHANOL (5 G/KG, GAVAGE) WITH OR WITHOUT LPS (2 MG/KG, INTRAPERITONEAL) FOR 6 HOURS. TBETA4 (1 MG/KG, INTRAPERITONEAL) WAS ADMINISTERED FOR 1 WEEK. WE DEMONSTRATED THAT TBETA4 PREVENTED ETHANOL- AND LPS-MEDIATED INCREASE IN LIVER INJURY MARKERS AS WELL AS CHANGES IN LIVER PATHOLOGY. IT ALSO PREVENTED ETHANOL- AND LPS-MEDIATED INCREASE IN OXIDATIVE STRESS BY DECREASING ROS AND LIPID PEROXIDATION AND INCREASING THE ANTIOXIDANTS, REDUCED GLUTATHIONE AND MANGANESE-DEPENDENT SUPEROXIDE DISMUTASE. IT ALSO PREVENTED THE ACTIVATION OF NUCLEAR FACTOR KAPPA B BY BLOCKING THE PHOSPHORYLATION OF THE INHIBITORY PROTEIN, IKAPPAB, THEREBY PREVENTED PROINFLAMMATORY CYTOKINE PRODUCTION. MOREOVER, TBETA4 PREVENTED FIBROGENESIS BY SUPPRESSING THE EPIGENETIC REPRESSOR, METHYL-CPG-BINDING PROTEIN 2, THAT COORDINATELY REVERSED THE EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AND DOWNREGULATED FIBROGENIC GENES, PLATELET-DERIVED GROWTH FACTOR-BETA RECEPTOR, ALPHA-SMOOTH MUSCLE ACTIN, COLLAGEN 1, AND FIBRONECTIN, RESULTING IN REDUCED FIBROSIS. OUR DATA SUGGEST THAT TBETA4 HAS ANTIOXIDANT, ANTI-INFLAMMATORY, AND ANTIFIBROTIC POTENTIAL DURING ALCOHOLIC LIVER INJURY. 2018 3 5013 31 PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AS A THERAPEUTIC TARGET FOR HEPATIC FIBROSIS: FROM BENCH TO BEDSIDE. HEPATIC FIBROSIS IS A DYNAMIC CHRONIC LIVER DISEASE OCCURRING AS A CONSEQUENCE OF WOUND-HEALING RESPONSES TO VARIOUS HEPATIC INJURIES. THIS DISORDER IS ONE OF PRIMARY PREDICTORS FOR LIVER-ASSOCIATED MORBIDITY AND MORTALITY WORLDWIDE. TO DATE, NO PHARMACOLOGICAL AGENT HAS BEEN APPROVED FOR HEPATIC FIBROSIS OR COULD BE RECOMMENDED FOR ROUTINE USE IN CLINICAL CONTEXT. CELLULAR AND MOLECULAR UNDERSTANDING OF HEPATIC FIBROSIS HAS REVEALED THAT PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPARGAMMA), THE FUNCTIONING RECEPTOR FOR ANTIDIABETIC THIAZOLIDINEDIONES, PLAYS A PIVOTAL ROLE IN THE PATHOBIOLOGY OF HEPATIC STELLATE CELLS (HSCS), WHOSE ACTIVATION IS THE CENTRAL EVENT IN THE PATHOGENESIS OF HEPATIC FIBROSIS. ACTIVATION OF PPARGAMMA INHIBITS HSC COLLAGEN PRODUCTION AND MODULATES HSC ADIPOGENIC PHENOTYPE AT TRANSCRIPTIONAL AND EPIGENETIC LEVELS. THESE MOLECULAR INSIGHTS INDICATE PPARGAMMA AS A PROMISING DRUG TARGET FOR ANTIFIBROTIC CHEMOTHERAPY. INTENSIVE ANIMAL STUDIES HAVE DEMONSTRATED THAT STIMULATION OF PPARGAMMA REGULATORY SYSTEM THROUGH GENE THERAPY APPROACHES AND PPARGAMMA LIGANDS HAS THERAPEUTIC PROMISE FOR HEPATIC FIBROSIS INDUCED BY A VARIETY OF ETIOLOGIES. AT THE SAME TIME, THIAZOLIDINEDIONE AGENTS HAVE BEEN INVESTIGATED FOR THEIR CLINICAL BENEFITS PRIMARILY IN PATIENTS WITH NONALCOHOLIC STEATOHEPATITIS, A COMMON METABOLIC LIVER DISORDER WITH HIGH POTENTIAL TO PROGRESS TO FIBROSIS AND LIVER-RELATED DEATH. ALTHOUGH SOME STUDIES HAVE SHOWN INITIAL PROMISE, NONE HAS ESTABLISHED LONG-TERM EFFICACY IN WELL-CONTROLLED RANDOMIZED CLINICAL TRIALS. THIS COMPREHENSIVE REVIEW COVERS THE 10-YEAR DISCOVERIES OF THE MOLECULAR BASIS FOR PPARGAMMA REGULATION OF HSC PATHOPHYSIOLOGY AND THEN FOCUSES ON THE ANIMAL INVESTIGATIONS AND CLINICAL TRIALS OF VARIOUS THERAPEUTIC MODALITIES TARGETING PPARGAMMA FOR HEPATIC FIBROSIS. 2013 4 4159 35 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 5 4501 26 MORPHOGENS AND HEPATIC STELLATE CELL FATE REGULATION IN CHRONIC LIVER DISEASE. HEPATIC STELLATE CELLS (HSC) ARE THE LIVER MESENCHYMAL CELL TYPE WHICH RESPONDS TO HEPATOCELLULAR DAMAGE AND PARTICIPATES IN WOUND HEALING. ALTHOUGH HSC MYOFIBROBLASTIC TRANS-DIFFERENTIATION (ACTIVATION) IS IMPLICATED IN EXCESSIVE EXTRACELLULAR MATRIX DEPOSITION, MOLECULAR UNDERSTANDING OF THIS PHENOTYPIC SWITCH FROM THE VIEWPOINT OF CELL FATE REGULATION IS LIMITED. RECENT STUDIES DEMONSTRATE THE ROLES OF ANTI-ADIPOGENIC MORPHOGENS (WNT, NECDIN, SHH) IN EPIGENETIC REPRESSION OF THE HSC DIFFERENTIATION GENE PPARGAMMA AS A CAUSAL EVENT IN HSC ACTIVATION. THESE MORPHOGENS HAVE POSITIVE CROSS-INTERACTIONS WHICH CONVERGE TO EPIGENETIC REPRESSION OF PPARGAMMA INVOLVING THE METHYL-CPG BINDING PROTEIN MECP2. HOWEVER, THESE MORPHOGENS EXPRESSED BY ACTIVATED HSC MAY ALSO PARTICIPATE IN CROSS-TALK BETWEEN HSC AND HEPATOBLASTS/HEPATOCYTES TO SUPPORT LIVER REGENERATION, AND THEIR ABERRANT REGULATION MAY CONTRIBUTE TO LIVER TUMORIGENESIS. IMPLICATIONS OF HSC-DERIVED MORPHOGENS IN THESE POSSIBILITIES ARE DISCUSSED. 2012 6 5012 26 PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA AS A TARGET AND REGULATOR OF EPIGENETIC MECHANISMS IN NONALCOHOLIC FATTY LIVER DISEASE. PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPARGAMMA) BELONGS TO THE SUPERFAMILY OF NUCLEAR RECEPTORS THAT CONTROL THE TRANSCRIPTION OF MULTIPLE GENES. ALTHOUGH IT IS FOUND IN MANY CELLS AND TISSUES, PPARGAMMA IS MOSTLY EXPRESSED IN THE LIVER AND ADIPOSE TISSUE. PRECLINICAL AND CLINICAL STUDIES SHOW THAT PPARGAMMA TARGETS SEVERAL GENES IMPLICATED IN VARIOUS FORMS OF CHRONIC LIVER DISEASE, INCLUDING NONALCOHOLIC FATTY LIVER DISEASE (NAFLD). CLINICAL TRIALS ARE CURRENTLY UNDERWAY TO INVESTIGATE THE BENEFICIAL EFFECTS OF PPARGAMMA AGONISTS ON NAFLD/NONALCOHOLIC STEATOHEPATITIS. UNDERSTANDING PPARGAMMA REGULATORS MAY THEREFORE AID IN UNRAVELING THE MECHANISMS GOVERNING THE DEVELOPMENT AND PROGRESSION OF NAFLD. RECENT ADVANCES IN HIGH-THROUGHPUT BIOLOGY AND GENOME SEQUENCING HAVE GREATLY FACILITATED THE IDENTIFICATION OF EPIGENETIC MODIFIERS, INCLUDING DNA METHYLATION, HISTONE MODIFIERS, AND NON-CODING RNAS AS KEY FACTORS THAT REGULATE PPARGAMMA IN NAFLD. IN CONTRAST, LITTLE IS STILL KNOWN ABOUT THE PARTICULAR MOLECULAR MECHANISMS UNDERLYING THE INTRICATE RELATIONSHIPS BETWEEN THESE EVENTS. THE PAPER THAT FOLLOWS OUTLINES OUR CURRENT UNDERSTANDING OF THE CROSSTALK BETWEEN PPARGAMMA AND EPIGENETIC REGULATORS IN NAFLD. ADVANCES IN THIS FIELD ARE LIKELY TO AID IN THE DEVELOPMENT OF EARLY NONINVASIVE DIAGNOSTICS AND FUTURE NAFLD TREATMENT STRATEGIES BASED ON PPARGAMMA EPIGENETIC CIRCUIT MODIFICATION. 2023 7 6757 37 WNT SIGNALING IN LIVER FIBROSIS: PROGRESS, CHALLENGES AND POTENTIAL DIRECTIONS. LIVER FIBROSIS IS A COMMON WOUND-HEALING RESPONSE TO CHRONIC LIVER INJURIES, INCLUDING ALCOHOLIC OR DRUG TOXICITY, PERSISTENT VIRAL INFECTION, AND GENETIC FACTORS. MYOFIBROBLASTIC TRANSDIFFERENTIATION (MTD) IS THE PIVOTAL EVENT DURING LIVER FIBROGENESIS, AND RESEARCH IN THE PAST FEW YEARS HAS IDENTIFIED KEY MEDIATORS AND MOLECULAR MECHANISMS RESPONSIBLE FOR MTD OF HEPATIC STELLATE CELLS (HSCS). HSCS ARE UNDIFFERENTIATED CELLS WHICH PLAY AN IMPORTANT ROLE IN LIVER REGENERATION. RECENT EVIDENCE DEMONSTRATES THAT HSCS DERIVE FROM MESODERM AND AT LEAST IN PART VIA SEPTUM TRANSVERSUM AND MESOTHELIUM, AND HSCS EXPRESS MARKERS FOR DIFFERENT CELL TYPES WHICH DERIVE FROM MULTIPOTENT MESENCHYMAL PROGENITORS. THERE IS A REGULATORY COMMONALITY BETWEEN DIFFERENTIATION OF ADIPOCYTES AND THAT OF HSC, AND THE SHIFT FROM ADIPOGENIC TO MYOGENIC OR NEURONAL PHENOTYPE CHARACTERIZES HSC MTD. CENTRAL OF THIS SHIFT IS A LOSS OF EXPRESSION OF THE MASTER ADIPOGENIC REGULATOR PEROXISOME PROLIFERATOR ACTIVATED RECEPTOR GAMMA (PPARGAMMA). RESTORED EXPRESSION OF PPARGAMMA AND/OR OTHER ADIPOGENIC TRANSCRIPTION GENES CAN REVERSE MYOFIBROBLASTIC HSCS TO DIFFERENTIATED CELLS. VERTEBRATE WNT AND DROSOPHILA WINGLESS ARE HOMOLOGOUS GENES, AND THEIR TRANSLATED PROTEINS HAVE BEEN SHOWN TO PARTICIPATE IN THE REGULATION OF CELL PROLIFERATION, CELL POLARITY, CELL DIFFERENTIATION, AND OTHER BIOLOGICAL ROLES. MORE RECENTLY, WNT SIGNALING IS IMPLICATED IN HUMAN FIBROSING DISEASES, SUCH AS PULMONARY FIBROSIS, RENAL FIBROSIS, AND LIVER FIBROSIS. BLOCKING THE CANONICAL WNT SIGNAL PATHWAY WITH THE CO-RECEPTOR ANTAGONIST DICKKOPF-1 (DKK1) ABROGATES THESE EPIGENETIC REPRESSIONS AND RESTORES THE GENE PPARGAMMA EXPRESSION AND HSC DIFFERENTIATION. THE IDENTIFIED MORPHOGEN MEDIATED EPIGENETIC REGULATION OF PPARGAMMA AND HSC DIFFERENTIATION ALSO SERVES AS NOVEL THERAPEUTIC TARGETS FOR LIVER FIBROSIS AND LIVER REGENERATION. IN CONCLUSION, THE WNT SIGNALING PROMOTES LIVER FIBROSIS BY ENHANCING HSC ACTIVATION AND SURVIVAL, AND WE HEREIN DISCUSS WHAT WE CURRENTLY KNOW AND WHAT WE EXPECT WILL COME IN THIS FIELD IN THE NEXT FUTURE. 2013 8 3295 29 HIGH PHOSPHATE-INDUCED DOWNREGULATION OF PPARGAMMA CONTRIBUTES TO CKD-ASSOCIATED VASCULAR CALCIFICATION. MEDIAL ARTERIAL CALCIFICATION ASSOCIATED WITH HYPERPHOSPHATEMIA IS A MAIN CAUSE OF CARDIOVASCULAR MORTALITY IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD), BUT THE MECHANISMS UNDERLYING HIGH PHOSPHATE-INDUCED VASCULAR CALCIFICATION REMAIN LARGELY UNKNOWN. HERE, WE OBSERVED A SIGNIFICANT DECREASE IN THE EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPARGAMMA) IN CALCIFIED ARTERIES BOTH IN CKD PATIENTS AND IN A MOUSE MODEL OF CKD WITH HYPERPHOSPHATEMIA. IN VITRO, HIGH PHOSPHATE TREATMENT LED TO A DECREASED EXPRESSION OF PPARGAMMA IN MOUSE VASCULAR SMOOTH MUSCLE CELLS (VMSCS), ACCOMPANIED BY APPARENT OSTEOGENIC DIFFERENTIATION AND CALCIFICATION. PRETREATMENT WITH PPARGAMMA AGONIST ROSIGLITAZONE SIGNIFICANTLY REVERSED HIGH PHOSPHATE-INDUCED VSMCS CALCIFICATION. FURTHER INVESTIGATION SHOWED THAT METHYL-CPG BINDING PROTEIN 2 (MECP2)-MEDIATED EPIGENETIC REPRESSION WAS INVOLVED IN HIGH PHOSPHATE-INDUCED PPARGAMMA DOWNREGULATION. MOREOVER, THE EXPRESSION OF KLOTHO THAT HAS THE ABILITY TO INHIBIT VASCULAR CALCIFICATION BY REGULATING PHOSPHATE UPTAKE DECREASED WITH THE PPARGAMMA REDUCTION IN VSMCS AFTER HIGH PHOSPHATE TREATMENT, AND ROSIGLITAZONE FAILED TO INHIBIT HIGH PHOSPHATE-INDUCED CALCIFICATION IN VSMCS WITH KNOCKDOWN OF KLOTHO OR IN AORTIC RINGS FROM KLOTHO-DEFICIENT (KL/KL) MICE. FINALLY, AN IN VIVO STUDY DEMONSTRATED THAT ORAL ADMINISTRATION OF ROSIGLITAZONE COULD INCREASE KLOTHO EXPRESSION AND PROTECT AGAINST HIGH PHOSPHATE-INDUCED VASCULAR CALCIFICATION IN CKD MICE. THESE FINDINGS SUGGEST THAT THE INHIBITION OF PPARGAMMA EXPRESSION MAY CONTRIBUTE TO THE PATHOGENESIS OF HIGH PHOSPHATE-INDUCED VASCULAR CALCIFICATION, WHICH MAY PROVIDE A NEW THERAPEUTIC TARGET FOR VASCULAR CALCIFICATION IN CKD PATIENTS. 2018 9 2118 36 EPIGENETIC HISTONE METHYLATION OF PPARGAMMA AND CPT1A SIGNALING CONTRIBUTES TO BETAHISTINE PREVENTING OLANZAPINE-INDUCED DYSLIPIDEMIA. AS A PARTIAL HISTAMINE H1 RECEPTOR AGONIST AND H3 ANTAGONIST, BETAHISTINE HAS BEEN REPORTED TO PARTIALLY PREVENT OLANZAPINE-INDUCED DYSLIPIDEMIA AND OBESITY THROUGH A COMBINATION THERAPY, ALTHOUGH THE UNDERLYING EPIGENETIC MECHANISMS ARE STILL NOT KNOWN. RECENT STUDIES HAVE REVEALED THAT HISTONE REGULATION OF KEY GENES FOR LIPOGENESIS AND ADIPOGENESIS IN THE LIVER IS ONE OF THE CRUCIAL MECHANISMS FOR OLANZAPINE-INDUCED METABOLIC DISORDERS. THIS STUDY INVESTIGATED THE ROLE OF EPIGENETIC HISTONE REGULATION IN BETAHISTINE CO-TREATMENT PREVENTING DYSLIPIDEMIA AND FATTY LIVER CAUSED BY CHRONIC OLANZAPINE TREATMENT IN A RAT MODEL. IN ADDITION TO ABNORMAL LIPID METABOLISM, THE UPREGULATION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPARGAMMA) AND CCAAT/ENHANCER BINDING PROTEIN (C/EBPALPHA), AS WELL AS THE DOWNREGULATION OF CARNITINE PALMITOYLTRANSFERASE 1A (CPT1A) IN THE LIVER INDUCED BY OLANZAPINE, WERE SIGNIFICANTLY ATTENUATED BY BETAHISTINE CO-TREATMENT. IN ADDITION, BETAHISTINE CO-TREATMENT SIGNIFICANTLY ENHANCED THE GLOBAL EXPRESSION OF H3K4ME AND THE ENRICHMENT OF H3K4ME BINDING ON THE PROMOTER OF CPT1A GENE AS REVEALED BY CHIP-QPCR, BUT INHIBITED THE EXPRESSION OF ONE OF ITS SITE-SPECIFIC DEMETHYLASES, LYSINE (K)-SPECIFIC DEMETHYLASE 1A (KDM1A). BETAHISTINE CO-TREATMENT ALSO SIGNIFICANTLY ENHANCED THE GLOBAL EXPRESSION OF H3K9ME AND THE ENRICHMENT OF H3K9ME BINDING ON THE PROMOTER OF THE PPARG GENE, BUT INHIBITED THE EXPRESSION OF TWO OF ITS SITE-SPECIFIC DEMETHYLASES, LYSINE DEMETHYLASE 4B (KDM4B) AND PHD FINGER PROTEIN 2 (PHF2). THESE RESULTS SUGGEST THAT BETAHISTINE ATTENUATES ABNORMAL ADIPOGENESIS AND LIPOGENESIS TRIGGERED BY OLANZAPINE THROUGH MODULATING HEPATIC HISTONE METHYLATION, AND THUS INHIBITING THE PPARGAMMA PATHWAY-MEDIATED LIPID STORAGE, WHILE AT THE SAME TIME PROMOTING CP1A-MEDIATED FATTY ACID OXIDATION. 2023 10 3359 23 HISTONE H4 LYSINE 16 ACETYLATION CONTROLS CENTRAL CARBON METABOLISM AND DIET-INDUCED OBESITY IN MICE. NONCOMMUNICABLE DISEASES (NCDS) ACCOUNT FOR OVER 70% OF DEATHS WORLD-WIDE. PREVIOUS WORK HAS LINKED NCDS SUCH AS TYPE 2 DIABETES (T2D) TO DISRUPTION OF CHROMATIN REGULATORS. HOWEVER, THE EXACT MOLECULAR ORIGINS OF THESE CHRONIC CONDITIONS REMAIN ELUSIVE. HERE, WE IDENTIFY THE H4 LYSINE 16 ACETYLTRANSFERASE MOF AS A CRITICAL REGULATOR OF CENTRAL CARBON METABOLISM. HIGH-THROUGHPUT METABOLOMICS UNVEIL A SYSTEMIC AMINO ACID AND CARBOHYDRATE IMBALANCE IN MOF DEFICIENT MICE, MANIFESTING IN T2D PREDISPOSITION. ORAL GLUCOSE TOLERANCE TESTING (OGTT) REVEALS DEFECTS IN GLUCOSE ASSIMILATION AND INSULIN SECRETION IN THESE ANIMALS. FURTHERMORE, MOF DEFICIENT MICE ARE RESISTANT TO DIET-INDUCED FAT GAIN DUE TO DEFECTS IN GLUCOSE UPTAKE IN ADIPOSE TISSUE. MOF-MEDIATED H4K16AC DEPOSITION CONTROLS EXPRESSION OF THE MASTER REGULATOR OF GLUCOSE METABOLISM, PPARG AND THE ENTIRE DOWNSTREAM TRANSCRIPTIONAL NETWORK. GLUCOSE UPTAKE AND LIPID STORAGE CAN BE RECONSTITUTED IN MOF-DEPLETED ADIPOCYTES IN VITRO BY ECTOPIC GLUT4 EXPRESSION, PPARGAMMA AGONIST THIAZOLIDINEDIONE (TZD) TREATMENT OR SIRT1 INHIBITION. HENCE, CHRONIC IMBALANCE IN H4K16AC PROMOTES A DESTABILISATION OF METABOLISM TRIGGERING THE DEVELOPMENT OF A METABOLIC DISORDER, AND ITS MAINTENANCE PROVIDES AN UNPRECEDENTED REGULATORY EPIGENETIC MECHANISM CONTROLLING DIET-INDUCED OBESITY. 2021 11 5187 21 PRENATAL AIRBORNE POLYCYCLIC AROMATIC HYDROCARBON EXPOSURE, ALTERED REGULATION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPAR)GAMMA, AND LINKS WITH MAMMARY CANCER. ENVIRONMENTAL EXPOSURE TO POLYCYCLIC AROMATIC HYDROCARBONS (PAH) HAS BEEN SHOWN TO BE ASSOCIATED WITH CHRONIC DISEASE OUTCOMES THROUGH MULTIPLE MECHANISMS INCLUDING ALTERED REGULATION OF THE TRANSCRIPTION FACTOR PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPAR) GAMMA. BECAUSE PAH EXPOSURE AND PPARGAMMA EACH HAVE BEEN ASSOCIATED WITH MAMMARY CANCER, WE ASKED WHETHER PAH WOULD INDUCE ALTERED REGULATION OF PPARGAMMA IN MAMMARY TISSUE, AND WHETHER THIS ASSOCIATION MAY UNDERLIE THE ASSOCIATION BETWEEN PAH AND MAMMARY CANCER. PREGNANT MICE WERE EXPOSED TO AEROSOLIZED PAH AT PROPORTIONS THAT MIMIC EQUIVALENT HUMAN EXPOSURES IN NEW YORK CITY AIR. WE HYPOTHESIZED THAT PRENATAL PAH EXPOSURE WOULD ALTER PPARGAMMA DNA METHYLATION AND GENE EXPRESSION AND INDUCE THE EPITHELIAL TO MESENCHYMAL TRANSITION (EMT) IN MAMMARY TISSUE OF OFFSPRING (F1) AND GRANDOFFSPRING (F2) MICE. WE ALSO HYPOTHESIZED THAT ALTERED REGULATION OF PPARGAMMA IN MAMMARY TISSUE WOULD ASSOCIATE WITH BIOMARKERS OF EMT, AND EXAMINED ASSOCIATIONS WITH WHOLE BODY WEIGHT. WE FOUND THAT PRENATAL PAH EXPOSURE LOWERED PPARGAMMA MAMMARY TISSUE METHYLATION AMONG GRANDOFFSPRING MICE AT POSTNATAL DAY (PND) 28. HOWEVER, PAH EXPOSURE DID NOT ASSOCIATE WITH ALTERED PPARGAMMA GENE EXPRESSION OR CONSISTENTLY WITH BIOMARKERS OF EMT. FINALLY, LOWER PPARGAMMA METHYLATION, BUT NOT GENE EXPRESSION, WAS ASSOCIATED WITH HIGHER BODY WEIGHT AMONG OFFSPRING AND GRANDOFFSPRING MICE AT PND28 AND PND60. FINDINGS SUGGEST ADDITIONAL EVIDENCE OF MULTI-GENERATIONAL ADVERSE EPIGENETIC EFFECTS OF PRENATAL PAH EXPOSURE AMONG GRANDOFFSPRING MICE. 2023 12 3242 35 HEPATIC NCOR1 DELETION EXACERBATES ALCOHOL-INDUCED LIVER INJURY IN MICE BY PROMOTING CCL2-MEDIATED MONOCYTE-DERIVED MACROPHAGE INFILTRATION. NUCLEAR RECEPTOR COREPRESSOR 1 (NCOR1) IS A COREPRESSOR OF THE EPIGENETIC REGULATION OF GENE TRANSCRIPTION THAT HAS IMPORTANT FUNCTIONS IN METABOLISM AND INFLAMMATION, BUT LITTLE IS KNOWN ABOUT ITS ROLE IN ALCOHOL-ASSOCIATED LIVER DISEASE (ALD). IN THIS STUDY, WE DEVELOPED MICE WITH HEPATOCYTE-SPECIFIC NCOR1 KNOCKOUT (NCOR1(HEP-/-)) USING THE ALBUMIN-CRE/LOXP SYSTEM AND INVESTIGATED THE ROLE OF NCOR1 IN THE PATHOGENESIS OF ALD AND THE UNDERLYING MECHANISMS. THE TRADITIONAL ALCOHOL FEEDING MODEL AND NIAAA MODEL OF ALD WERE BOTH ESTABLISHED IN WILD-TYPE AND NCOR1(HEP-/-) MICE. WE SHOWED THAT AFTER ALD WAS ESTABLISHED, NCOR1(HEP-/-) MICE HAD WORSE LIVER INJURY BUT LESS STEATOSIS THAN WILD-TYPE MICE. WE DEMONSTRATED THAT HEPATOCYTE-SPECIFIC LOSS OF NCOR1 ATTENUATED LIVER STEATOSIS BY PROMOTING FATTY ACID OXIDATION BY UPREGULATING BMAL1 (A CIRCADIAN CLOCK COMPONENT THAT HAS BEEN REPORTED TO PROMOTE PEROXISOME PROLIFERATOR ACTIVATED RECEPTOR ALPHA (PPARALPHA)-MEDIATED FATTY BETA-OXIDATION BY UPREGULATING DE NOVO LIPID SYNTHESIS). ON THE OTHER HAND, HEPATOCYTE-SPECIFIC LOSS OF NCOR1 EXACERBATED ALCOHOL-INDUCED LIVER INFLAMMATION AND OXIDATIVE STRESS BY RECRUITING MONOCYTE-DERIVED MACROPHAGES VIA C-C MOTIF CHEMOKINE LIGAND 2 (CCL2). IN THE MOUSE HEPATOCYTE LINE AML12, NCOR1 KNOCKDOWN SIGNIFICANTLY INCREASED ETHANOL-INDUCED CCL2 RELEASE. THESE RESULTS SUGGEST THAT HEPATOCYTE NCOR1 PLAYS DISTINCT ROLES IN CONTROLLING LIVER INFLAMMATION AND STEATOSIS, WHICH PROVIDES NEW INSIGHTS INTO THE DEVELOPMENT OF TREATMENTS FOR STEATOHEPATITIS INDUCED BY CHRONIC ALCOHOL CONSUMPTION. 2022 13 2969 44 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 14 3240 28 HEPATIC LIPID ACCUMULATION ALTERS GLOBAL HISTONE H3 LYSINE 9 AND 4 TRIMETHYLATION IN THE PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA NETWORK. RECENT DATA SUGGEST THAT THE ETIOLOGY OF SEVERAL METABOLIC DISEASES IS CLOSELY ASSOCIATED WITH TRANSCRIPTOME ALTERATION BY ABERRANT HISTONE METHYLATION. WE PERFORMED DNA MICROARRAY AND CHIP-ON-CHIP ANALYSES TO EXAMINE TRANSCRIPTOME PROFILING AND TRIMETHYLATION ALTERATIONS TO IDENTIFY THE GENOMIC SIGNATURE OF NONALCOHOLIC FATTY LIVER DISEASE (NAFLD), THE MOST COMMON FORM OF CHRONIC LIVER DISEASE. TRANSCRIPTOME ANALYSIS SHOWED THAT STEATOTIC LIVERS IN HIGH-FAT DIET-FED APOLIPOPROTEIN E2 MICE SIGNIFICANTLY ALTERED THE EXPRESSION OF APPROXIMATELY 70% OF TOTAL GENES COMPARED WITH NORMAL DIET-FED CONTROL LIVERS, SUGGESTING THAT HEPATIC LIPID ACCUMULATION INDUCES DRAMATIC ALTERATIONS IN GENE EXPRESSION IN VIVO. ALSO, PATHWAY ANALYSIS SUGGESTED THAT GENES ENCODING CHROMATIN-REMODELING ENZYMES, SUCH AS JUMONJI C-DOMAIN-CONTAINING HISTONE DEMETHYLASES THAT REGULATE HISTONE H3K9 AND H3K4 TRIMETHYLATION (H3K9ME3, H3K4ME3), WERE SIGNIFICANTLY ALTERED IN STEATOTIC LIVERS. THUS, WE FURTHER INVESTIGATED THE GLOBAL H3K9ME3 AND H3K4ME3 STATUS IN LIPID-ACCUMULATED MOUSE PRIMARY HEPATOCYTES BY CHIP-ON-CHIP ANALYSIS. RESULTS SHOWED THAT HEPATIC LIPID ACCUMULATION INDUCED ABERRANT H3K9ME3 AND H3K4ME3 STATUS IN PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ALPHA AND HEPATIC LIPID CATABOLISM NETWORK GENES, REDUCING THEIR MRNA EXPRESSION COMPARED WITH NON-TREATED CONTROL HEPATOCYTES. THIS STUDY PROVIDES THE FIRST EVIDENCE THAT EPIGENETIC REGULATION BY H3K9ME3 AND H3K4ME3 IN HEPATOCYTES MAY BE INVOLVED IN HEPATIC STEATOSIS AND THE PATHOGENESIS OF NAFLD. THUS, CONTROL OF H3K9ME3 AND H3K4ME3 REPRESENTS A POTENTIAL NOVEL NAFLD PREVENTION AND TREATMENT STRATEGY. 2012 15 699 24 BROMODOMAIN PROTEIN 4 IS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HEPATIC STELLATE CELL ACTIVATION. LIVER FIBROSIS IS CHARACTERIZED BY THE EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX IN LIVER. CHRONIC LIVER INJURY INDUCES THE ACTIVATION OF HEPATIC STELLATE CELL (HSCS), A KEY STEP IN LIVER FIBROGENESIS. THE ACTIVATED HSC IS THE PRIMARY SOURCE OF ECM AND CONTRIBUTES SIGNIFICANTLY TO LIVER FIBROSIS. TGFBETA1 IS THE MOST POTENT PRO-FIBROTIC CYTOKINE. BROMODOMAIN PROTEIN 4 (BRD4), AN EPIGENETIC READER OF HISTONE ACETYLATION MARKS, WAS CRUCIAL FOR PROFIBROTIC GENE EXPRESSION IN HSCS. THE PRESENT STUDY AIMED TO INVESTIGATE THE ROLES OF BRD4 IN TGFBETA1-DEPENDENT HSC ACTIVATION AND LIVER FIBROSIS, FOCUSING ON TGFBETA1-INDUCED ALTERATIONS OF THE LEVELS OF THE FIBROTIC-RELATED IMPORTANT PROTEINS IN HSCS BY EMPLOYING THE HETEROZYGOUS TGFBETA1 KNOCKOUT MICE AND BRD4 KNOCKDOWN IN VIVO AND IN VITRO. RESULTS REVEALED THAT BRD4 PROTEIN LEVEL WAS SIGNIFICANTLY UPREGULATED BY TGFBETA1 AND BRD4 KNOCKDOWN REDUCED TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. BRD4 WAS REQUIRED FOR THE INFLUENCES OF TGFBETA1 ON PDGFBETA RECEPTOR AND ON THE PATHWAYS OF SMAD3, STAT3, AND AKT. BRD4 ALSO MEDIATED TGFBETA1-INDUCED INCREASES IN HISTONE ACETYLTRANSFERASE P300, THE PIVOTAL PRO-INFLAMMATORY NFKB P65, AND TISSUE INHIBITOR OF METALLOPROTEINASE 1 WHEREAS BRD4 REDUCED CASPASE-3 PROTEIN LEVELS IN HSCS DURING LIVER INJURY, INDEPENDENT OF TGFBETA1. FURTHER EXPERIMENTS INDICATED THE INTERACTION BETWEEN TGFBETA1-INDUCED BRD4 AND NFKB P65 IN HSCS AND IN LIVER OF TAA-INDUCED LIVER INJURY. HUMAN CIRRHOTIC LIVERS WERE DEMONSTRATED A PARALLEL INCREASE IN THE PROTEIN LEVELS OF BRD4 AND NFKB P65 IN HSCS. THIS STUDY REVEALED THAT BRD4 WAS A KEY MOLECULAR DRIVER OF TGFBETA1-INDUCED HSC ACTIVATION AND LIVER FIBROSIS. 2023 16 1764 29 EARLY-IMMEDIATE GENE EGR1 IS ASSOCIATED WITH TGFBETA1 REGULATION OF EPIGENETIC READER BROMODOMAIN-CONTAINING PROTEIN 4 VIA THE CANONICAL SMAD3 SIGNALING IN HEPATIC STELLATE CELLS IN VITRO AND IN VIVO. UPON CHRONIC DAMAGE TO THE LIVER, MULTIPLE CYTOKINES STIMULATE HEPATIC STELLATE CELLS (HSCS), CAUSING THE ALTERATIONS OF GENE EXPRESSION PROFILES AND THUS LEADING TO HSC ACTIVATION, A KEY STEP IN LIVER FIBROGENESIS. ACTIVATED HSCS ARE THE DOMINANT CONTRIBUTORS TO LIVER FIBROSIS. BROMODOMAIN CONTAINING PROTEIN 4 (BRD4), AN IMPORTANT EPIGENETIC READER, WAS DEMONSTRATED TO CONCENTRATE ON HUNDREDS OF ENHANCERS ASSOCIATED WITH GENES INVOLVED IN MULTIPLE PROFIBROTIC PATHWAYS, THEREBY DIRECTING HSC ACTIVATION AND THE FIBROTIC RESPONSES. THE PRESENT STUDIES WERE DESIGNED TO EXAMINE THE EFFECT OF TRANSFORMING GROWTH FACTOR BETA-1 (TGFBETA1), THE MOST POTENT PRO-FIBROTIC CYTOKINE, ON BRD4 EXPRESSION IN HSCS AND, IF SO, ELUCIDATED THE UNDERLYING MECHANISMS IN VITRO AND IN VIVO. THE EXPERIMENTS EMPLOYED THE HETEROGENEOUS TGFBETA1 KNOCKOUT (TGFBETA1(+/-) ) MICE, GENE KNOCKDOWN IN VIVO, AND A MODEL OF THIOACETAMIDE (TAA)-INDUCED LIVER INJURY. THE RESULTS REVEALED THAT TGFBETA1 ENHANCED BRD4 EXPRESSION IN HSCS, WHICH WAS MEDIATED, AT LEAST, BY SMAD3 SIGNALING AND EARLY-IMMEDIATE GENE EGR1 (EARLY GROWTH RESPONSE-1). TGFBETA1-INDUCED SMAD3 SIGNALING INCREASED EGR1 EXPRESSION AND PROMOTED EGR1 BINDING TO BRD4 PROMOTER AT A SITE AROUND -111 BP, PROMOTING BRD4 EXPRESSION. EGR1 KNOCKDOWN REDUCED BRD4 EXPRESSION IN HSCS IN A MOUSE MODEL OF TAA-INDUCED LIVER INJURY AND LESSENED LIVER FIBROSIS. DOUBLE FLUORESCENCE STAINING DEMONSTRATED A STRONG INCREASE IN BRD4 EXPRESSION IN ACTIVATED HSCS IN FIBROTIC AREAS OF THE HUMAN LIVERS, PARALLELING THE UPREGULATION OF P-SMAD3 AND EGR1. THIS RESEARCH SUGGESTED NOVEL MOLECULAR EVENTS UNDERLYING THE ROLES OF THE MASTER PRO-FIBROTIC CYTOKINE TGFBETA1 IN HSC ACTIVATION AND LIVER FIBROGENESIS. 2022 17 1792 28 EFFECT OF CHRONIC WESTERN DIETS ON NON-ALCOHOLIC FATTY LIVER OF MALE MICE MODIFYING THE PPAR-GAMMA PATHWAY VIA MIR-27B-5P REGULATION. WESTERN DIETS CONTRIBUTE TO METABOLIC DISEASES. HOWEVER, THE EFFECTS OF VARIOUS DIETS AND EPIGENETIC MECHANISMS ARE MOSTLY UNKNOWN. HERE, SIX WEEK-OLD C57BL/6J MALE AND FEMALE MICE WERE FED WITH A LOW-FAT DIET (LFD), HIGH-FAT DIET (HFD), AND HIGH-FAT HIGH-FRUCTOSE DIET (HFD-HF) FOR 20 WEEKS. WE DETERMINED THAT HFD-HF OR HFD MICE EXPERIENCED SIGNIFICANT METABOLIC DYSREGULATION COMPARED TO THE LFD. HFD-HF AND HFD-FED MALE MICE SHOWED SIGNIFICANTLY INCREASED BODY WEIGHT, LIVER SIZE, AND FASTING GLUCOSE LEVELS WITH DOWNREGULATED PPARGAMMA, SCD1, AND FAS PROTEIN EXPRESSION. IN CONTRAST, FEMALE MICE WERE LESS AFFECTED BY HFD AND HFD-HF. AS MIR-27B CONTAINS A SEED SEQUENCE IN PPARGAMMA, IT WAS DISCOVERED THAT THESE CHANGES ARE ACCOMPANIED BY MALE-SPECIFIC UPREGULATION OF MIR-27B-5P, WHICH IS EVEN MORE PRONOUNCED IN THE HFD-HF GROUP (P < 0.01 VS. LFD) COMPARED TO THE HFD GROUP (P < 0.05 VS. LFD). OTHER MIR-27 SUBTYPES WERE INCREASED BUT NOT SIGNIFICANTLY. HFD-HF SHOWED INSIGNIFICANT CHANGES IN FIBROSIS MARKERS WHEN COMPARED TO LFD. INTERESTINGLY, FAT BALLOONING IN HEPATOCYTES WAS INCREASED IN HFD-FED MICE COMPARED TO HFD-HF FED MICE, HOWEVER, THE HFD-HF LIVER SHOWED AN INCREASE IN THE NUMBER OF SMALL CELLS. HERE, WE CONCLUDED THAT CHRONIC WESTERN DIET-COMPOSITION ADMINISTERED FOR 20 WEEKS MAY SURPASS THE NON-ALCOHOLIC FATTY LIVER (NAFL) STAGE BUT MAY BE AT AN INTERMEDIATE STAGE BETWEEN FATTY LIVER AND FIBROSIS VIA MIR-27B-5P-INDUCED PPARGAMMA DOWNREGULATION. 2021 18 1906 30 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 19 5760 28 SOLUBLE URIC ACID PRIMES TLR-INDUCED PROINFLAMMATORY CYTOKINE PRODUCTION BY HUMAN PRIMARY CELLS VIA INHIBITION OF IL-1RA. OBJECTIVES: THE STUDY OF THE PROINFLAMMATORY ROLE OF URIC ACID HAS FOCUSED ON THE EFFECTS OF ITS CRYSTALS OF MONOSODIUM URATE (MSU). HOWEVER, LITTLE IS KNOWN WHETHER URIC ACID ITSELF CAN DIRECTLY HAVE PROINFLAMMATORY EFFECTS. IN THIS STUDY, WE INVESTIGATE THE PRIMING EFFECTS OF URIC ACID EXPOSURE ON THE CYTOKINE PRODUCTION OF PRIMARY HUMAN CELLS UPON STIMULATION WITH GOUT-RELATED STIMULI. METHODS: PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) WERE HARVESTED FROM PATIENTS WITH GOUT AND HEALTHY VOLUNTEERS. CELLS WERE PRETREATED WITH OR WITHOUT URIC ACID IN SOLUBLE FORM FOR 24 H AND THEN STIMULATED FOR 24 H WITH TOLL-LIKE RECEPTOR (TLR)2 OR TLR4 LIGANDS IN THE PRESENCE OR ABSENCE OF MSU CRYSTALS. CYTOKINE PRODUCTION WAS MEASURED BY ELISA; MRNA LEVELS WERE ASSESSED USING QPCR. RESULTS: THE PRODUCTION OF INTERLEUKIN (IL)-1BETA AND IL-6 WAS HIGHER IN PATIENTS COMPARED WITH CONTROLS AND THIS CORRELATED WITH SERUM URATE LEVELS. PROINFLAMMATORY CYTOKINE PRODUCTION WAS SIGNIFICANTLY POTENTIATED WHEN CELLS FROM HEALTHY SUBJECTS WERE PRETREATED WITH URIC ACID. SURPRISINGLY, THIS WAS ASSOCIATED WITH A SIGNIFICANT DOWNREGULATION OF THE ANTI-INFLAMMATORY CYTOKINE IL-1 RECEPTOR ANTAGONIST (IL-1RA). THIS EFFECT WAS SPECIFIC TO STIMULATION BY URIC ACID AND WAS EXERTED AT THE LEVEL OF GENE TRANSCRIPTION. EPIGENETIC REPROGRAMMING AT THE LEVEL OF HISTONE METHYLATION BY URIC ACID WAS INVOLVED IN THIS EFFECT. CONCLUSIONS: IN THIS STUDY WE DEMONSTRATE A MECHANISM THROUGH WHICH HIGH CONCENTRATIONS OF URIC ACID (UP TO 50 MG/DL) INFLUENCE INFLAMMATORY RESPONSES BY FACILITATING IL-1BETA PRODUCTION IN PBMCS. WE SHOW THAT A MECHANISM FOR THE AMPLIFICATION OF IL-1BETA CONSISTS IN THE DOWNREGULATION OF IL-1RA AND THAT THIS EFFECT COULD BE EXERTED VIA EPIGENETIC MECHANISMS SUCH AS HISTONE METHYLATION. HYPERURICAEMIA CAUSES A SHIFT IN THE IL-1BETA/IL-1RA BALANCE PRODUCED BY PBMCS AFTER EXPOSURE TO MSU CRYSTALS AND TLR-MEDIATED STIMULI, AND THIS PHENOMENON IS LIKELY TO REINFORCE THE ENHANCED STATE OF CHRONIC INFLAMMATION. 2016 20 701 17 BROWN FAT DNMT3B DEFICIENCY AMELIORATES OBESITY IN FEMALE MICE. OBESITY RESULTS FROM A CHRONIC ENERGY IMBALANCE DUE TO ENERGY INTAKE EXCEEDING ENERGY EXPENDITURE. ACTIVATION OF BROWN FAT THERMOGENESIS HAS BEEN SHOWN TO COMBAT OBESITY. EPIGENETIC REGULATION, INCLUDING DNA METHYLATION, HAS EMERGED AS A KEY REGULATOR OF BROWN FAT THERMOGENIC FUNCTION. HERE WE AIMED TO STUDY THE ROLE OF DNMT3B, A DNA METHYLTRANSFERASE INVOLVED IN DE NOVO DNA METHYLATION, IN THE REGULATION OF BROWN FAT THERMOGENESIS AND OBESITY. WE FOUND THAT THE SPECIFIC DELETION OF DNMT3B IN BROWN FAT PROMOTES THE THERMOGENIC AND MITOCHONDRIAL PROGRAM IN BROWN FAT, ENHANCES ENERGY EXPENDITURE, AND DECREASES ADIPOSITY IN FEMALE MICE FED A REGULAR CHOW DIET. WITH A LEAN PHENOTYPE, THE FEMALE KNOCKOUT MICE ALSO EXHIBIT INCREASED INSULIN SENSITIVITY. IN ADDITION, DNMT3B DEFICIENCY IN BROWN FAT ALSO PREVENTS DIET-INDUCED OBESITY AND INSULIN RESISTANCE IN FEMALE MICE. INTERESTINGLY, OUR RNA-SEQ ANALYSIS REVEALED AN UPREGULATION OF THE PI3K-AKT PATHWAY IN THE BROWN FAT OF FEMALE DNMT3B KNOCKOUT MICE. HOWEVER, MALE DNMT3B KNOCKOUT MICE HAVE NO CHANGE IN THEIR BODY WEIGHT, SUGGESTING THE EXISTENCE OF SEXUAL DIMORPHISM IN THE BROWN FAT DNMT3B KNOCKOUT MODEL. OUR DATA DEMONSTRATE THAT DNMT3B PLAYS AN IMPORTANT ROLE IN THE REGULATION OF BROWN FAT FUNCTION, ENERGY METABOLISM AND OBESITY IN FEMALE MICE. 2021