1 4034 101 M6A METHYLATION PROMOTES WHITE-TO-BEIGE FAT TRANSITION BY FACILITATING HIF1A TRANSLATION. OBESITY MAINLY RESULTS FROM A CHRONIC ENERGY IMBALANCE. PROMOTING BROWNING OF WHITE ADIPOCYTES IS A PROMISING STRATEGY TO ENHANCE ENERGY EXPENDITURE AND COMBAT OBESITY. N6-METHYLADENOSINE (M6A), THE MOST ABUNDANT MRNA MODIFICATION IN EUKARYOTES, PLAYS AN IMPORTANT ROLE IN REGULATING ADIPOGENESIS. HOWEVER, WHETHER M6A REGULATES WHITE ADIPOCYTE BROWNING WAS UNKNOWN. HERE, WE REPORT THAT ADIPOSE TISSUE-SPECIFIC DELETION OF FTO, AN M6A DEMETHYLASE, PREDISPOSES MICE TO PREVENT HIGH-FAT DIET (HFD)-INDUCED OBESITY BY ENHANCING ENERGY EXPENDITURE. ADDITIONALLY, DELETION OF FTO IN VITRO PROMOTES THERMOGENESIS AND WHITE-TO-BEIGE ADIPOCYTE TRANSITION. MECHANISTICALLY, FTO DEFICIENCY INCREASES THE M6A LEVEL OF HIF1A MRNA, WHICH IS RECOGNIZED BY M6A-BINDING PROTEIN YTHDC2, FACILITATING MRNA TRANSLATION AND INCREASING HIF1A PROTEIN ABUNDANCE. HIF1A ACTIVATES THE TRANSCRIPTION OF THERMOGENIC GENES, INCLUDING PPAGGC1A, PRDM16, AND PPARG, THEREBY PROMOTING UCP1 EXPRESSION AND THE BROWNING PROCESS. COLLECTIVELY, THESE RESULTS UNVEIL AN EPIGENETIC MECHANISM BY WHICH M6A-FACILITATED HIF1A EXPRESSION CONTROLS BROWNING OF WHITE ADIPOCYTES AND THERMOGENESIS, PROVIDING A POTENTIAL TARGET TO COUNTERACT OBESITY AND METABOLIC DISEASE. 2021 2 2301 27 EPIGENETIC REGULATION OF BEIGE ADIPOCYTE FATE BY HISTONE METHYLATION. ADIPOSE TISSUE HARBORS PLASTICITY TO ADAPT TO ENVIRONMENTAL THERMAL CHANGES. WHILE BROWN ADIPOCYTE IS A THERMOGENIC CELL WHICH PRODUCES HEAT ACUTELY IN RESPONSE TO COLD STIMULI, BEIGE (OR BRITE) ADIPOCYTE IS AN INDUCIBLE FORM OF THERMOGENIC ADIPOCYTES WHICH EMERGES IN THE WHITE ADIPOSE DEPOTS IN RESPONSE TO CHRONIC COLD EXPOSURE. SUCH ADAPTABILITY OF ADIPOCYTES IS REGULATED BY EPIGENETIC MECHANISMS. AMONG THEM, HISTONE METHYLATION IS CHEMICALLY STABLE AND THUS IS AN APPROPRIATE EPIGENETIC MARK FOR MEDIATING CELLULAR MEMORY TO INDUCE AND MAINTAIN THE BEIGE ADIPOCYTE CHARACTERISTICS. THE ENZYMES THAT CATALYZE THE METHYLATION OR DEMETHYLATION OF H3K27 AND H3K9 REGULATE BROWN ADIPOCYTE BIOGENESIS THROUGH THEIR CATALYTIC ACTIVITY-DEPENDENT AND -INDEPENDENT MECHANISMS. RESOLVING THE BIVALENCY OF H3K4ME3 AND H3K27ME3 AS WELL AS "OPENING" THE CHROMATIN STRUCTURE BY DEMETHYLATION OF H3K9 BOTH MEDIATE BEIGE ADIPOGENESIS. IN ADDITION, IT IS RECENTLY REPORTED THAT MAINTENANCE OF BEIGE ADIPOCYTE, BEIGE-TO-WHITE TRANSITION, AND CELLULAR MEMORY OF PRIOR COLD EXPOSURE IN BEIGE ADIPOCYTE ARE ALSO REGULATED BY HISTONE METHYLATION. A FURTHER UNDERSTANDING OF THE EPIGENETIC MECHANISM OF BEIGE ADIPOCYTE BIOGENESIS WOULD UNRAVEL THE MECHANISM OF THE CELLULAR MEMORY OF ENVIRONMENTAL STIMULI AND PROVIDE A NOVEL THERAPEUTICS FOR THE METABOLIC DISORDERS SUCH AS OBESITY AND DIABETES THAT ARE INFLUENCED BY ENVIRONMENTAL FACTORS. 2019 3 240 34 ADIPOCYTE EXPRESSION OF SLC19A1 LINKS DNA HYPERMETHYLATION TO ADIPOSE TISSUE INFLAMMATION AND INSULIN RESISTANCE. CONTEXT: INSULIN RESISTANCE (IR) IS PROMOTED BY A CHRONIC LOW-GRADE INFLAMMATION IN WHITE ADIPOSE TISSUE (WAT). THE LATTER MIGHT BE REGULATED THROUGH EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION. THE ONE CARBON CYCLE (1CC) IS A CENTRAL METABOLIC PROCESS GOVERNING DNA METHYLATION. OBJECTIVE: TO IDENTIFY ADIPOCYTE-EXPRESSED 1CC GENES LINKED TO WAT INFLAMMATION, IR, AND THEIR CAUSAL ROLE. DESIGN: COHORT STUDY. SETTING: OUTPATIENT ACADEMIC CLINIC. PARTICIPANTS: OBESE AND NONOBESE SUBJECTS. METHODS: GENE EXPRESSION AND DNA METHYLATION ARRAYS WERE PERFORMED IN SUBCUTANEOUS WAT AND ISOLATED ADIPOCYTES. IN IN VITRO DIFFERENTIATED HUMAN ADIPOCYTES, GENE KNOCKDOWN WAS ACHIEVED BY SMALL INTERFERING RNA, AND ANALYSES INCLUDED MICROARRAY, QUANTITATIVE POLYMERASE CHAIN REACTION, DNA METHYLATION BY ENZYME-LINKED IMMUNOSORBENT ASSAY AND PYROSEQUENCING, PROTEIN SECRETION BY ENZYME-LINKED IMMUNOSORBENT ASSAY, TARGETED METABOLOMICS, AND LUCIFERASE REPORTER AND THERMAL SHIFT ASSAYS. MAIN OUTCOME MEASURES: EFFECTS ON ADIPOCYTE INFLAMMATION. RESULTS: IN ADIPOCYTES FROM OBESE INDIVIDUALS, GLOBAL DNA HYPERMETHYLATION WAS ASSOCIATED POSITIVELY WITH GENE EXPRESSION OF PROINFLAMMATORY PATHWAYS. AMONG THE 1CC GENES, IR IN VIVO AND PROINFLAMMATORY GENE EXPRESSION IN WAT WERE MOST STRONGLY AND INVERSELY ASSOCIATED WITH SLC19A1, A GENE ENCODING A MEMBRANE FOLATE CARRIER. SLC19A1 KNOCKDOWN IN HUMAN ADIPOCYTES PERTURBED INTRACELLULAR 1CC METABOLISM, INDUCED GLOBAL DNA HYPERMETHYLATION, AND INCREASED EXPRESSION OF PROINFLAMMATORY GENES. SEVERAL CPG LOCI LINKED SLC19A1 TO INFLAMMATION; VALIDATION STUDIES WERE FOCUSED ON THE CHEMOKINE C-C MOTIF CHEMOKINE LIGAND 2 (CCL2) IN WHICH METHYLATION IN THE PROMOTER (CG12698626) REGULATED CCL2 EXPRESSION AND CCL2 SECRETION THROUGH ALTERED TRANSCRIPTIONAL ACTIVITY. CONCLUSIONS: REDUCED SLC19A1 EXPRESSION IN HUMAN ADIPOCYTES INDUCES DNA HYPERMETHYLATION, RESULTING IN INCREASED EXPRESSION OF SPECIFIC PROINFLAMMATORY GENES, INCLUDING CCL2. THIS CONSTITUTES AN EPIGENETIC MECHANISM THAT MIGHT LINK DYSFUNCTIONAL ADIPOCYTES TO WAT INFLAMMATION AND IR. 2018 4 1725 26 DYSREGULATION OF INFLAMMATION, OXIDATIVE STRESS, AND GLUCOSE METABOLISM-RELATED GENES AND MIRNAS IN VISCERAL ADIPOSE TISSUE OF WOMEN WITH TYPE 2 DIABETES MELLITUS. BACKGROUND HUMAN VISCERAL ADIPOSE TISSUE (VAT), NOW IDENTIFIED AS AN ENDOCRINE ORGAN, PLAYS A SIGNIFICANT ROLE IN IMPAIRED FASTING GLUCOSE AND DIABETES THROUGH THE DEREGULATED METABOLISM AND ADIPOGENESIS OF VISCERAL ADIPOCYTES IN OBESITY. OUR STUDY FOCUSES ON EXPLORING THE LINK BETWEEN INFLAMMATION, OXIDATIVE STRESS, AND GLUCOSE METABOLISM-ASSOCIATED GENES WITH CORRESPONDING MIRNAS IN HUMAN VISCERAL ADIPOCYTES AND VAT FROM INDIVIDUALS WITH GLUCOSE METABOLISM DISORDERS. MATERIAL AND METHODS WE EXAMINED THE EXPRESSION OF ATM, NFKB1, SOD2, INSR, AND TIGAR, ALONG WITH THEIR RELATED MIRNAS USING PCR, IN TWO CONTEXTS:1 - DURING THE THREE-STAGE VISCERAL ADIPOGENESIS UNDER NORMAL GLUCOSE LEVELS (5.5 MILLIMOLES), INTERMITTENT, AND CHRONIC HYPERGLYCEMIA (30 MILLIMOLES).2 - IN VISCERAL ADIPOSE TISSUE FROM SUBJECTS (34 F, 18 M) WITH NORMAL GLUCOSE METABOLISM, IMPAIRED FASTING GLUCOSE, AND TYPE 2 DIABETES MELLITUS. RESULTS BOTH CHRONIC AND INTERMITTENT HYPERGLYCEMIA SIMILARLY INFLUENCED ATM, NFKB1, TIGAR, SOD2, INSR GENE EXPRESSION IN VISCERAL ADIPOCYTES, WITH CORRESPONDING CHANGES IN A FEW TESTED MIRNAS (EG, LET-7G-5P, MIR-145-5P, MIR-21-5P). ANTHROPOMETRIC AND BIOCHEMICAL PARAMETERS LED US TO FOCUS ON FEMALE SUBJECTS. OUR RESULTS SHOWED TRANSACTIVATION OF NFKB1, TIGAR, MIR-10B-5P, MIR-132-3P, MIR-20A-5P, MIR-21-5P, AND MIR-26A-5P EXCLUSIVELY IN TYPE 2 DIABETES MELLITUS. UPREGULATED MOLECULES (EXCLUDING MIR-10B-5P AND MIR-20A-5P) POSITIVELY CORRELATED WITH GLUCOSE METABOLISM MARKERS. CONCLUSIONS THE GENES STUDIED MAY UNDERGO MIRNA INTERFERENCES AND HYPERGLYCEMIC MEMORY IN VISCERAL ADIPOCYTES UNDER HYPERGLYCEMIC CONDITIONS. VAT FROM WOMEN WITH TYPE 2 DIABETES MELLITUS, BUT NOT WITH IMPAIRED FASTING GLUCOSE, SHOWED TRANSACTIVATED MIRNAS AND A MOLECULAR DYSREGULATION OF TIGAR AND NFKB1, POSSIBLY ENHANCING INFLAMMATION, OXIDATIVE STRESS, AND DISRUPTED GLUCOSE METABOLISM. THESE FINDINGS HIGHLIGHT THE EPIGENETIC AND MOLECULAR DISTURBANCES IN VAT RELATED TO GLUCOSE METABOLISM ABNORMALITIES. HOWEVER, ADDITIONAL RESEARCH IS NECESSARY TO FURTHER UNDERSTAND THEIR BIOLOGICAL SIGNIFICANCE. 2023 5 3155 26 GLUTAMINE METABOLISM IN ADIPOCYTES: A BONA FIDE EPIGENETIC MODULATOR OF INFLAMMATION. A CHRONIC LOW-GRADE INFLAMMATION OF WHITE ADIPOSE TISSUE (WAT) IS ONE OF THE HALLMARKS OF OBESITY AND IS PROPOSED TO CONTRIBUTE TO INSULIN RESISTANCE AND TYPE 2 DIABETES. DESPITE THIS, THE CAUSAL MECHANISMS UNDERLYING WAT INFLAMMATION REMAIN UNCLEAR. BASED ON METABOLOMIC ANALYSES OF HUMAN WAT, PETRUS ET AL. SHOWED THAT THE AMINO ACID GLUTAMINE WAS THE MOST MARKEDLY REDUCED POLAR METABOLITE IN THE OBESE STATE. REDUCED GLUTAMINE LEVELS IN ADIPOCYTES INDUCE AN INCREASE OF URIDINE DIPHOSPHATE N-ACETYLGLUCOSAMINE (UDP-GLCNAC) LEVELS VIA INDUCTION OF GLYCOLYSIS AND THE HEXOSAMINE BIOSYNTHETIC PATHWAYS. THIS PROMOTES NUCLEAR O-GLCNACYLATION, A POSTTRANSLATIONAL MODIFICATION THAT ACTIVATES THE TRANSCRIPTION OF PRO-INFLAMMATORY GENES. CONVERSELY, GLUTAMINE SUPPLEMENTATION IN VITRO AND IN VIVO, REVERSED THESE EFFECTS. ALTOGETHER, DYSREGULATION OF INTRACELLULAR GLUTAMINE METABOLISM IN WAT ESTABLISHES AN EPIGENETIC LINK BETWEEN ADIPOCYTES AND INFLAMMATION. THIS COMMENTARY DISCUSSES THESE FINDINGS AND THEIR POSSIBLY THERAPEUTIC RELEVANCE IN RELATION TO INSULIN RESISTANCE AND TYPE 2 DIABETES. 2020 6 875 21 CHRONIC AND TRANSIENT HYPERGLYCEMIA INDUCES CHANGES IN THE EXPRESSION PATTERNS OF IL6 AND ADIPOQ GENES AND THEIR ASSOCIATED EPIGENETIC MODIFICATIONS IN DIFFERENTIATING HUMAN VISCERAL ADIPOCYTES. ADIPOKINES SECRETED BY HYPERTROPHIC VISCERAL ADIPOSE TISSUE (VAT) INSTIGATE LOW-GRADE INFLAMMATION, FOLLOWED BY HYPERGLYCEMIA (HG)-RELATED METABOLIC DISORDERS. THE LATTER MAY DEVELOP WITH THE PARTICIPATION OF EPIGENETIC MODIFICATIONS. OUR AIM WAS TO ASSESS HOW HG INFLUENCES SELECTED EPIGENETIC MODIFICATIONS AND THE EXPRESSION OF INTERLEUKIN 6 (IL-6) AND ADIPONECTIN (APN; GENE SYMBOL ADIPOQ) DURING THE ADIPOGENESIS OF HUMAN VISCERAL PREADIPOCYTES (HPA-V). ADIPOCYTES (ADS) WERE CHRONICALLY OR TRANSIENTLY HG-TREATED DURING THREE STAGES OF ADIPOGENESIS (PROLIFERATION, DIFFERENTIATION, MATURATION). WE MEASURED ADIPOKINE MRNA, PROTEIN, PROVEN OR PREDICTED MICRORNA EXPRESSION (RT-QPCR AND ELISA), AND ENRICHMENT OF H3K9/14AC, H3K4ME3, AND H3K9ME3 AT GENE PROMOTER REGIONS (CHROMATIN IMMUNOPRECIPITATION). IN CHRONIC HG, WE DETECTED DIFFERENT EXPRESSION PATTERNS OF THE STUDIED ADIPOKINES AT THE MRNA AND PROTEIN LEVELS. CHRONIC AND TRANSIENT HG-INDUCED CHANGES IN MIRNA (MIR-26A-5P, MIR-26B-5P, LET-7D-5P, LET-7E-5P, MIR-365A-3P, MIR-146A-5P) WERE MOSTLY CONVERGENT TO ALTERED IL-6 TRANSCRIPTION. ALTERATIONS IN HISTONE MARKS AT THE IL6 PROMOTER WERE ALSO IN AGREEMENT WITH IL-6 MRNA. THE OPEN CHROMATIN MARKS AT THE ADIPOQ PROMOTER MOSTLY REFLECTED THE APN TRANSCRIPTION DURING NG ADIPOGENESIS, WHILE, IN THE DIFFERENTIATION STAGE, HG-INDUCED CHANGES IN ALL STUDIED MARKS WERE IN LINE WITH APN MRNA LEVELS. IN SUMMARY, HG DYSREGULATED ADIPOKINE EXPRESSION, PROMOTING INFLAMMATION. EPIGENETIC CHANGES COEXISTED WITH ALTERED EXPRESSION OF ADIPOKINES, ESPECIALLY FOR IL-6; THEREFORE, EPIGENETIC MARKS INDUCED BY TRANSIENT HG MAY ACT AS EPI-MEMORY IN ADS. SUCH CHANGES IN THE EPIGENOME AND EXPRESSION OF ADIPOKINES COULD BE INSTRUMENTAL IN THE DEVELOPMENT OF INFLAMMATION AND METABOLIC DEREGULATION OF VAT. 2021 7 5332 29 PYRUVATE DEHYDROGENASE KINASE 1 AND 2 DEFICIENCY REDUCES HIGH-FAT DIET-INDUCED HYPERTROPHIC OBESITY AND INHIBITS THE DIFFERENTIATION OF PREADIPOCYTES INTO MATURE ADIPOCYTES. OBESITY IS NOW RECOGNIZED AS A DISEASE. THIS STUDY REVEALED A NOVEL ROLE FOR PYRUVATE DEHYDROGENASE KINASE (PDK) IN DIET-INDUCED HYPERTROPHIC OBESITY. MICE WITH GLOBAL OR ADIPOSE TISSUE-SPECIFIC PDK2 DEFICIENCY WERE PROTECTED AGAINST DIET-INDUCED OBESITY. THE WEIGHT OF ADIPOSE TISSUES AND THE SIZE OF ADIPOCYTES WERE REDUCED. ADIPOCYTE-SPECIFIC PDK2 DEFICIENCY SLIGHTLY INCREASED INSULIN SENSITIVITY IN HFD-FED MICE. IN STUDIES WITH 3T3-L1 PREADIPOCYTES, PDK2 AND PDK1 EXPRESSION WAS STRONGLY INCREASED DURING ADIPOGENESIS. EVIDENCE WAS FOUND FOR EPIGENETIC INDUCTION OF BOTH PDK1 AND PDK2. GAIN- AND LOSS-OF-FUNCTION STUDIES WITH 3T3-L1 CELLS REVEALED A CRITICAL ROLE FOR PDK1/2 IN ADIPOCYTE DIFFERENTIATION AND LIPID ACCUMULATION. PDK1/2 INDUCTION DURING DIFFERENTIATION WAS ALSO ACCOMPANIED BY INCREASED EXPRESSION OF HYPOXIA-INDUCIBLE FACTOR-1ALPHA (HIF1ALPHA) AND ENHANCED LACTATE PRODUCTION, BOTH OF WHICH WERE ABSENT IN THE CONTEXT OF PDK1/2 DEFICIENCY. EXOGENOUS LACTATE SUPPLEMENTATION INCREASED THE STABILITY OF HIF1ALPHA AND PROMOTED ADIPOGENESIS. PDK1/2 OVEREXPRESSION-MEDIATED ADIPOGENESIS WAS ABOLISHED BY HIF1ALPHA INHIBITION, SUGGESTING A ROLE FOR THE PDK-LACTATE-HIF1ALPHA AXIS DURING ADIPOGENESIS. IN HUMAN ADIPOSE TISSUE, THE EXPRESSION OF PDK1/2 WAS POSITIVELY CORRELATED WITH THAT OF THE ADIPOGENIC MARKER PPARGAMMA AND INVERSELY CORRELATED WITH OBESITY. SIMILARLY, PDK1/2 EXPRESSION IN MOUSE ADIPOSE TISSUE WAS DECREASED BY CHRONIC HIGH-FAT DIET FEEDING. WE CONCLUDE THAT PDK1 AND 2 ARE NOVEL REGULATORS OF ADIPOGENESIS THAT PLAY CRITICAL ROLES IN OBESITY. 2021 8 2754 31 EXPRESSION OF CAVEOLIN 1 IS ENHANCED BY DNA DEMETHYLATION DURING ADIPOCYTE DIFFERENTIATION. STATUS OF INSULIN SIGNALING. CAVEOLIN 1 (CAV-1) IS AN ESSENTIAL CONSTITUENT OF ADIPOCYTE CAVEOLAE WHICH BINDS THE BETA SUBUNIT OF THE INSULIN RECEPTOR (IR) AND IS IMPLICATED IN THE REGULATION OF INSULIN SIGNALING. WE HAVE FOUND THAT, DURING ADIPOCYTE DIFFERENTIATION OF 3T3-L1 CELLS THE PROMOTER, EXON 1 AND FIRST INTRON OF THE CAV-1 GENE UNDERGO A DEMETHYLATION PROCESS THAT IS ACCOMPANIED BY A STRONG INDUCTION OF CAV-1 EXPRESSION, INDICATING THAT EPIGENETIC MECHANISMS MUST HAVE A PIVOTAL ROLE IN THIS DIFFERENTIATION PROCESS. FURTHERMORE, IR, PKB-AKT AND GLUT-4 EXPRESSION ARE ALSO INCREASED DURING THE DIFFERENTIATION PROCESS SUGGESTING A COORDINATED REGULATION WITH CAV-1. ACTIVATION OF CAV-1 PROTEIN BY PHOSPHORYLATION ARISES DURING THE DIFFERENTIATION PROCESS, YET IN FULLY MATURE ADIPOCYTES INSULIN IS NO LONGER ABLE TO SIGNIFICANTLY INCREASE CAV-1 PHOSPHORYLATION. HOWEVER, THESE LONG-TERM DIFFERENTIATED CELLS ARE STILL ABLE TO RESPOND ADEQUATELY TO INSULIN, INCREASING IR AND PKB-AKT PHOSPHORYLATION AND GLUCOSE UPTAKE. THE ACTIVATION OF CAV-1 DURING THE ADIPOCYTE DIFFERENTIATION PROCESS COULD FACILITATE THE MAINTENANCE OF INSULIN SENSITIVITY BY THESE FULLY MATURE ADIPOCYTES ISOLATED FROM ADDITIONAL EXTERNAL STIMULI. HOWEVER, UNDER THE INFLUENCE OF PHYSIOLOGICAL CONDITIONS ASSOCIATED TO OBESITY, SUCH AS CHRONIC INFLAMMATION AND HYPOXIA, INSULIN SENSITIVITY WOULD FINALLY BE COMPROMISED. 2014 9 4022 26 LSD1 FOR THE TARGETED REGULATION OF ADIPOSE TISSUE. WHITE AND THERMAL (BROWN AND BEIGE) ADIPOSE TISSUE ENERGY STORAGE AND OXIDATIVE REGULATION PATHWAYS PLAY A CENTRAL ROLE IN MAINTAINING THE ENERGY BALANCE THROUGHOUT THE BODY, AND THE DYSREGULATION OF THESE PATHWAYS IS CLOSELY RELATED TO GLUCOSE AND LIPID METABOLISM DISORDERS AND ADIPOSE TISSUE DYSFUNCTION, INCLUDING OBESITY, CHRONIC INFLAMMATION, INSULIN RESISTANCE, MITOCHONDRIAL DYSFUNCTION, AND FIBROSIS. RECENT EPIGENETIC STUDIES HAVE IDENTIFIED THE NOVEL REGULATORY ELEMENT LSD1, WHICH CONTROLS THE ABOVE PARAMETERS, AND HAVE PROVIDED NEW MECHANISTIC POSSIBILITIES FOR RE-ENCODING THE FATE AND FUNCTION OF ADIPOCYTES. IN THIS REVIEW, WE OUTLINE THE CURRENT ADVANCES IN ADIPOCYTE METABOLISM IN PHYSIOLOGY AND DISEASE AND DISCUSS POSSIBLE STRATEGIES FOR LSD1 TO ALTER THE PHENOTYPE OF ADIPOSE TISSUE AND THUS INFLUENCE ENERGY UTILIZATION TO IMPROVE METABOLIC HEALTH. 2022 10 701 37 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 11 2241 34 EPIGENETIC MODULATION IN PERIODONTITIS: INTERACTION OF ADIPONECTIN AND JMJD3-IRF4 AXIS IN MACROPHAGES. EMERGING EVIDENCE SUGGESTS AN IMPORTANT ROLE FOR EPIGENETIC MECHANISMS IN MODULATING SIGNALS DURING MACROPHAGE POLARIZATION AND INFLAMMATION. JMJD3, A JMJC FAMILY HISTONE DEMETHYLASE NECESSARY FOR M2 POLARIZATION IS ALSO REQUIRED FOR EFFECTIVE INDUCTION OF MULTIPLE M1 GENES BY LIPOPOLYSACCHARIDE (LPS). HOWEVER, THE EFFECTS OF JMJD3 TO INFLAMMATION IN THE CONTEXT OF OBESITY REMAINS UNKNOWN. TO ADDRESS THIS DEFICIENCY, WE FIRSTLY EXAMINED THE EXPRESSION OF JMJD3 IN MACROPHAGE ISOLATED FROM BONE MARROW AND ADIPOSE TISSUE OF DIET INDUCED OBESITY (DIO) MICE. THE RESULTS INDICATED THAT JMJD3 WAS DOWN-REGULATED IN OBESITY. ADIPONECTIN (APN), A FACTOR SECRETED BY ADIPOSE TISSUE WHICH IS DOWN-REGULATED IN OBESITY, FUNCTIONS TO SWITCH MACROPHAGE POLARIZATION FROM M1 TO M2, THEREBY ATTENUATING CHRONIC INFLAMMATION. INTRIGUINGLY, OUR RESULTS INDICATED THAT APN CONTRIBUTED TO JMJD3 UP-REGULATION, REDUCED MACROPHAGE INFILTRATION IN OBESE ADIPOSE TISSUE, AND ABOLISHED THE UP-REGULATION OF JMJD3 IN PERITONEAL MACROPHAGES ISOLATED FROM DIO MICE WHEN CHALLENGED WITH PORPHYROMONAS GINGIVALIS LPS (PG.LPS). TO ELUCIDATE THE INTERACTION OF APN AND JMJD3 INVOLVED IN MACROPHAGE TRANSFORMATION IN THE CONTEXT OF INFLAMMATION, WE DESIGNED THE LOSS AND GAIN-FUNCTION EXPERIMENTS OF APN IN VIVO WITH APN(-/-) MICE WITH EXPERIMENTAL PERIODONTITIS AND IN VITRO WITH MACROPHAGE ISOLATED FROM APN(-/-) MICE. FOR THE FIRST TIME, WE FOUND THAT APN CAN HELP TO REDUCE PERIODONTITIS-RELATED BONE LOSS, MODULATE JMJD3 AND IRF4 EXPRESSION, AND MACROPHAGE INFILTRATION. THEREFORE, IT CAN BE INFERRED THAT APN MAY CONTRIBUTE TO ANTI-INFLAMMATION MACROPHAGE POLARIZATION BY REGULATING JMJD3 EXPRESSION, WHICH PROVIDES A BASIS FOR MACROPHAGE-CENTERED EPIGENETIC THERAPEUTIC STRATEGIES. 2016 12 3359 32 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 13 6291 28 THE POTENTIAL TO FIGHT OBESITY WITH ADIPOGENESIS MODULATING COMPOUNDS. OBESITY IS AN INCREASINGLY SEVERE PUBLIC HEALTH PROBLEM, WHICH BRINGS HUGE SOCIAL AND ECONOMIC BURDENS. INCREASED BODY ADIPOSITY IN OBESITY IS NOT ONLY TIGHTLY ASSOCIATED WITH TYPE 2 DIABETES, BUT ALSO SIGNIFICANTLY INCREASES THE RISKS OF OTHER CHRONIC DISEASES INCLUDING CARDIOVASCULAR DISEASES, FATTY LIVER DISEASES AND CANCERS. ADIPOGENESIS DESCRIBES THE PROCESS OF THE DIFFERENTIATION AND MATURATION OF ADIPOCYTES, WHICH ACCUMULATE IN DISTRIBUTED ADIPOSE TISSUE AT VARIOUS SITES IN THE BODY. THE MAJOR FUNCTIONS OF WHITE ADIPOCYTES ARE TO STORE ENERGY AS FAT DURING PERIODS WHEN ENERGY INTAKE EXCEEDS EXPENDITURE AND TO MOBILIZE THIS STORED FUEL WHEN ENERGY EXPENDITURE EXCEEDS INTAKE. BROWN/BEIGE ADIPOCYTES CONTRIBUTE TO NON-SHIVERING THERMOGENESIS UPON COLD EXPOSURE AND ADRENERGIC STIMULATION, AND THEREBY PROMOTE ENERGY CONSUMPTION. THE IMBALANCE OF ENERGY INTAKE AND EXPENDITURE CAUSES OBESITY. RECENT INTEREST IN EPIGENETICS AND SIGNALING PATHWAYS HAS UTILIZED SMALL MOLECULE TOOLS AIMED AT MODIFYING OBESITY-SPECIFIC GENE EXPRESSION. IN THIS REVIEW, WE DISCUSS COMPOUNDS WITH ADIPOGENESIS-RELATED SIGNALING PATHWAYS AND EPIGENETIC MODULATING PROPERTIES THAT HAVE BEEN IDENTIFIED AS POTENTIAL THERAPEUTIC AGENTS WHICH CAST SOME LIGHT ON THE FUTURE TREATMENT OF OBESITY. 2022 14 241 27 ADIPOCYTE, IMMUNE CELLS, AND MIRNA CROSSTALK: A NOVEL REGULATOR OF METABOLIC DYSFUNCTION AND OBESITY. OBESITY IS CHARACTERIZED AS A COMPLEX AND MULTIFACTORIAL EXCESS ACCRETION OF ADIPOSE TISSUE (AT) ACCOMPANIED WITH ALTERATIONS IN THE IMMUNE RESPONSE THAT AFFECTS VIRTUALLY ALL AGE AND SOCIOECONOMIC GROUPS AROUND THE GLOBE. THE ABNORMAL ACCUMULATION OF AT LEADS TO SEVERAL METABOLIC DISEASES, INCLUDING NONALCOHOLIC FATTY LIVER DISORDER (NAFLD), LOW-GRADE INFLAMMATION, TYPE 2 DIABETES MELLITUS (T2DM), CARDIOVASCULAR DISORDERS (CVDS), AND CANCER. AT IS AN ENDOCRINE ORGAN COMPOSED OF ADIPOCYTES AND IMMUNE CELLS, INCLUDING B-CELLS, T-CELLS AND MACROPHAGES. THESE IMMUNE CELLS SECRETE VARIOUS CYTOKINES AND CHEMOKINES AND CROSSTALK WITH ADIPOKINES TO MAINTAIN METABOLIC HOMEOSTASIS AND LOW-GRADE CHRONIC INFLAMMATION. A NOVEL FORM OF ADIPOKINES, MICRORNA (MIRS), IS EXPRESSED IN MANY DEVELOPING PERIPHERAL TISSUES, INCLUDING ATS, T-CELLS, AND MACROPHAGES, AND MODULATES THE IMMUNE RESPONSE. MIRS ARE ESSENTIAL FOR INSULIN RESISTANCE, MAINTAINING THE TUMOR MICROENVIRONMENT, AND OBESITY-ASSOCIATED INFLAMMATION (OAI). THE ABNORMAL REGULATION OF AT, T-CELLS, AND MACROPHAGE MIRS MAY CHANGE THE FUNCTION OF DIFFERENT ORGANS INCLUDING THE PANCREAS, HEART, LIVER, AND SKELETAL MUSCLE. SINCE OBESITY AND INFLAMMATION ARE CLOSELY ASSOCIATED, THE DYSREGULATED EXPRESSION OF MIRS IN INFLAMMATORY ADIPOCYTES, T-CELLS, AND MACROPHAGES SUGGEST THE IMPORTANCE OF MIRS IN OAI. THEREFORE, IN THIS REVIEW ARTICLE, WE HAVE ELABORATED THE ROLE OF MIRS AS EPIGENETIC REGULATORS AFFECTING ADIPOCYTE DIFFERENTIATION, IMMUNE RESPONSE, AT BROWNING, ADIPOGENESIS, LIPID METABOLISM, INSULIN RESISTANCE (IR), GLUCOSE HOMEOSTASIS, OBESITY, AND METABOLIC DISORDERS. FURTHER, WE WILL DISCUSS A SET OF ALTERED MIRS AS NOVEL BIOMARKERS FOR METABOLIC DISEASE PROGRESSION AND THERAPEUTIC TARGETS FOR OBESITY. 2021 15 5878 31 SYNERGISTIC EFFECTS OF HYPERANDROGENEMIA AND OBESOGENIC WESTERN-STYLE DIET ON TRANSCRIPTION AND DNA METHYLATION IN VISCERAL ADIPOSE TISSUE OF NONHUMAN PRIMATES. POLYCYSTIC OVARY SYNDROME (PCOS) IS A MAJOR REPRODUCTIVE DISORDER THAT IS RESPONSIBLE FOR 80% OF ANOVULATORY INFERTILITY AND THAT IS ASSOCIATED WITH HYPERANDROGENEMIA, INCREASED RISK OF OBESITY, AND WHITE ADIPOSE TISSUE (WAT) DYSFUNCTION. WE HAVE PREVIOUSLY DEMONSTRATED THAT THE COMBINATION OF CHRONIC TESTOSTERONE (T) TREATMENT AND AN OBESOGENIC WESTERN-STYLE DIET (WSD) EXERTS SYNERGISTIC FUNCTIONAL EFFECTS ON WAT, LEADING TO INCREASED LIPID ACCUMULATION IN VISCERAL ADIPOCYTES BY AN UNKNOWN MECHANISM. IN THIS STUDY, WE EXAMINED THE WHOLE-GENOME TRANSCRIPTIONAL RESPONSE IN VISCERAL WAT TO T AND WSD, ALONE AND IN COMBINATION. WE OBSERVED A SYNERGISTIC EFFECT OF T AND WSD ON GENE EXPRESSION, RESULTING IN UPREGULATION OF LIPID STORAGE GENES CONCOMITANT WITH ADIPOCYTE HYPERTROPHY. BECAUSE DNA METHYLATION IS KNOWN TO BE ASSOCIATED WITH BODY FAT DISTRIBUTION AND THE ETIOLOGY OF PCOS, WE CONDUCTED WHOLE-GENOME DNA METHYLATION ANALYSIS OF VISCERAL WAT. WHILE ONLY A FRACTION OF DIFFERENTIALLY EXPRESSED GENES ALSO EXHIBITED DIFFERENTIAL DNA METHYLATION, IN SILICO ANALYSIS SHOWED THAT DIFFERENTIALLY METHYLATED REGIONS WERE ENRICHED IN TRANSCRIPTION FACTOR BINDING MOTIFS, SUGGESTING A POTENTIAL GENE REGULATORY ROLE FOR THESE REGIONS. IN SUMMARY, THIS STUDY DEMONSTRATES THAT HYPERANDROGENEMIA ALONE DOES NOT INDUCE GLOBAL TRANSCRIPTIONAL AND EPIGENETIC RESPONSE IN YOUNG FEMALE MACAQUES UNLESS COMBINED WITH AN OBESOGENIC DIET. 2019 16 3353 35 HISTONE DEMETHYLASES REGULATE ADIPOCYTE THERMOGENESIS. ADIPOCYTES PLAY A PIVOTAL ROLE IN THE REGULATION OF ENERGY METABOLISM. WHILE WHITE ADIPOCYTE STORES ENERGY, BROWN ADIPOCYTE DISSIPATES ENERGY BY PRODUCING HEAT. IN ADDITION, ANOTHER TYPE OF HEAT-PRODUCING ADIPOCYTE, BEIGE ADIPOCYTE, EMERGES IN WHITE ADIPOSE TISSUE IN RESPONSE TO CHRONIC COLDNESS. THIS PHENOTYPIC ADAPTATION TO THE COLD ENVIRONMENT IS CONSIDERED TO BE ATTRIBUTED TO THE EPIGENETIC MODIFICATIONS. HISTONE METHYLATION IS A CHEMICALLY STABLE EPIGENETIC MODIFICATION AND THUS A PROPER MECHANISM FOR LONG-LASTING CELLULAR MEMORY. SEVERAL HISTONE METHYL-MODIFYING ENZYMES SUCH AS EHMT1, JMJD1A, JMJD3, AND LSD1 ARE REPORTED TO BE INVOLVED IN THE BEIGE ADIPOSE CELL FATE DETERMINATION. AMONG THESE, A HISTONE DEMETHYLASE JMJD1A SENSES COLD ENVIRONMENT BY BEING PHOSPHORYLATED AT S265 IN RESPONSE TO BETA-ADRENERGIC RECEPTOR STIMULATION. PHOSPHORYLATED JMJD1A REGULATES BOTH ACUTE AND COLD THERMOGENESIS. UNDER ACUTE COLDNESS, PHOSPHORYLATED JMJD1A FORMS A COMPLEX WITH CHROMATIN REMODELER SWI/SNF AND DNA-BOUND PPARGAMMA, WHICH RECRUITS JMJD1A TO THE TARGET GENOMIC REGIONS IN BROWN ADIPOCYTE. THIS COMPLEX FORMATION, IN TURN, INDUCES THE EXPRESSION OF TARGET GENES BY BRINGING THE ENHANCER AND THE PROMOTER INTO CLOSE PROXIMITY. DURING CHRONIC COLDNESS, PHOSPHORYLATED JMJD1A REGULATES BEIGE ADIPOGENESIS THROUGH A TWO-STEP MECHANISM. IN THE FIRST STEP, PHOSPHORYLATED JMJD1A IS RECRUITED TO THE REGULATORY REGIONS OF TARGET GENES BY FORMING A COMPLEX WITH PRDM16, PGC1ALPHA, AND DNA-BOUND PPARGAMMA. IN THE SECOND STEP, JMJD1A DEMETHYLATES HISTONE H3K9ME2 AND INDUCES STABLE EXPRESSION OF BEIGE-SELECTIVE GENES. THE PHENOTYPIC ANALYSES OF JMJD1A-NULL MICE AND NON-PHOSPHORYLATED MUTANT S265A JMJD1A KNOCK-IN MICE INDICATE THAT JMJD1A IS A POTENTIAL THERAPEUTIC TARGET FOR THE TREATMENT OF OBESITY-RELATED DISEASES INCLUDING METABOLIC SYNDROME AND TYPE 2 DIABETES. 2018 17 6182 26 THE IMPACT OF ADIPOSE TISSUE-DERIVED MIRNAS IN METABOLIC SYNDROME, OBESITY, AND CANCER. OBESITY IS A MULTIFACTORIAL AND COMPLEX CONDITION THAT IS CHARACTERIZED BY ABNORMAL AND EXCESSIVE WHITE ADIPOSE TISSUE ACCUMULATION, WHICH CAN LEAD TO THE DEVELOPMENT OF METABOLIC DISEASES, SUCH AS TYPE 2 DIABETES MELLITUS, NONALCOHOLIC FATTY LIVER DISEASE, CARDIOVASCULAR DISEASES, AND SEVERAL TYPES OF CANCER. OBESITY IS CHARACTERIZED BY EXCESSIVE ADIPOSE TISSUE ACCUMULATION AND ASSOCIATED WITH ALTERATIONS IN IMMUNITY, DISPLAYING A CHRONIC LOW-GRADE INFLAMMATION PROFILE. ADIPOSE TISSUE IS A DYNAMIC AND COMPLEX ENDOCRINE ORGAN COMPOSED NOT ONLY BY ADIPOCYTES, BUT SEVERAL IMMUNOLOGICAL CELLS, WHICH CAN SECRETE HORMONES, CYTOKINES AND MANY OTHER FACTORS CAPABLE OF REGULATING METABOLIC HOMEOSTASIS AND SEVERAL CRITICAL BIOLOGICAL PATHWAYS. REMARKABLY, ADIPOSE TISSUE IS A MAJOR SOURCE OF CIRCULATING MICRORNAS (MIRNAS), RECENTLY DESCRIBED AS A NOVEL FORM OF ADIPOKINES. SEVERAL ADIPOSE TISSUE-DERIVED MIRNAS ARE DEEPLY ASSOCIATED WITH ADIPOCYTES DIFFERENTIATION AND HAVE BEEN IDENTIFIED WITH AN ESSENTIAL ROLE IN OBESITY-ASSOCIATED INFLAMMATION, INSULIN RESISTANCE, AND TUMOR MICROENVIRONMENT. DURING OBESITY, ADIPOSE TISSUE CAN COMPLETELY CHANGE THE PROFILE OF THE SECRETED MIRNAS, INFLUENCING CIRCULATING MIRNAS AND IMPACTING THE DEVELOPMENT OF DIFFERENT PATHOLOGICAL CONDITIONS, SUCH AS OBESITY, METABOLIC SYNDROME, AND CANCER. IN THIS REVIEW, WE DISCUSS HOW MIRNAS CAN ACT AS EPIGENETIC REGULATORS AFFECTING ADIPOGENESIS, ADIPOCYTE DIFFERENTIATION, LIPID METABOLISM, BROWNING OF THE WHITE ADIPOSE TISSUE, GLUCOSE HOMEOSTASIS, AND INSULIN RESISTANCE, IMPACTING DEEPLY OBESITY AND METABOLIC DISEASES. MOREOVER, WE CHARACTERIZE HOW MIRNAS CAN OFTEN ACT AS ONCOGENIC AND TUMOR SUPPRESSOR MOLECULES, SIGNIFICANTLY MODULATING CANCER ESTABLISHMENT AND PROGRESSION. FURTHERMORE, WE HIGHLIGHT IN THIS MANUSCRIPT HOW ADIPOSE TISSUE-DERIVED MIRNAS CAN FUNCTION AS IMPORTANT NEW THERAPEUTIC TARGETS. 2020 18 4307 37 MICRORNA-30 MODULATES METABOLIC INFLAMMATION BY REGULATING NOTCH SIGNALING IN ADIPOSE TISSUE MACROPHAGES. BACKGROUND/OBJECTIVES: OBESITY IS A PANDEMIC DISORDER THAT IS CHARACTERIZED BY ACCUMULATION OF ADIPOSE TISSUE AND CHRONIC LOW-GRADE INFLAMMATION THAT IS DRIVEN PRIMARILY BY ADIPOSE TISSUE MACROPHAGES (ATMS). WHILE ATM POLARIZATION FROM PRO-(M1) TO ANTI-(M2) INFLAMMATORY PHENOTYPE INFLUENCES INSULIN SENSITIVITY AND ENERGY EXPENDITURE, THE MECHANISMS OF SUCH A SWITCH ARE UNCLEAR. IN THE CURRENT STUDY, WE IDENTIFIED EPIGENETIC PATHWAYS INCLUDING MICRORNAS (MIR) IN ATMS THAT REGULATE OBESITY-INDUCED INFLAMMATION. SUBJECTS/METHODS: MALE C57BL/6J MICE WERE FED NORMAL CHOW DIET (NCD) OR HIGH-FAT DIET (HFD) FOR 16 WEEKS TO DEVELOP LEAN AND DIET-INDUCED OBESE MICE, RESPECTIVELY. TRANSCRIPTOME MICROARRAYS, MICRORNA MICROARRAYS, AND MEDIP-SEQ WERE PERFORMED ON ATMS ISOLATED FROM VISCERAL FAT. PATHWAY ANALYSIS AND BONE MARROW-DERIVED MACROPHAGE (BMDM) TRANSFECTIONS FURTHER ALLOWED COMPUTATIONAL AND FUNCTIONAL ANALYSIS OF MIRNA-MEDIATED ATM POLARIZATION. RESULTS: ATMS FROM HFD-FED MICE WERE SKEWED TOWARD M1 INFLAMMATORY PHENOTYPE. CONCURRENTLY, THE EXPRESSION OF MIRS 30A-5P, 30C-5P, AND 30E-5P WAS DOWNREGULATED IN ATMS FROM HFD MICE WHEN COMPARED TO MICE FED NCD. THE MIR-30 FAMILY WAS SHOWN TO TARGET DELTA-LIKE-4, A NOTCH1 LIGAND, WHOSE EXPRESSION WAS INCREASED IN HFD ATMS. INHIBITION OF MIR-30 IN CONDITIONED BMDM TRIGGERED NOTCH1 SIGNALING, PRO-INFLAMMATORY CYTOKINE PRODUCTION, AND M1 MACROPHAGE POLARIZATION. IN ADDITION, DNA HYPERMETHYLATION WAS OBSERVED IN MIR30-ASSOCIATED CPG ISLANDS, SUGGESTING THAT HFD DOWNREGULATES MIR-30 THROUGH EPIGENETIC MODIFICATIONS. CONCLUSIONS: HFD-INDUCED OBESITY DOWNREGULATES MIR-30 BY DNA METHYLATION THEREBY INDUCING NOTCH1 SIGNALING IN ATMS AND THEIR POLARIZATION TO M1 MACROPHAGES. THESE FINDINGS IDENTIFY MIR-30 AS A REGULATOR OF PRO-INFLAMMATORY ATM POLARIZATION AND SUGGEST THAT MIR-30 MANIPULATION COULD BE A THERAPEUTIC TARGET FOR OBESITY-INDUCED INFLAMMATION. 2018 19 3875 35 KDM2A DEFICIENCY IN MACROPHAGES ENHANCES THERMOGENESIS TO PROTECT MICE AGAINST HFD-INDUCED OBESITY BY ENHANCING H3K36ME2 AT THE PPARG LOCUS. KDM2A CATALYZES H3K36ME2 DEMETHYLATION TO PLAY AN INTRIGUING EPIGENETIC REGULATORY ROLE IN CELL PROLIFERATION, DIFFERENTIATION, AND APOPTOSIS. HEREIN WE FOUND THAT MYELOID-SPECIFIC KNOCKOUT OF KDM2A (LYSM-CRE-KDM2A(F/F), KDM2A(-/-)) PROMOTED MACROPHAGE M2 PROGRAM BY REPROGRAMING METABOLIC HOMEOSTASIS THROUGH ENHANCING FATTY ACID UPTAKE AND LIPOLYSIS. KDM2A(-/-) INCREASED H3K36ME2 LEVELS AT THE PPARG LOCUS ALONG WITH AUGMENTED CHROMATIN ACCESSIBILITY AND STAT6 RECRUITMENT, WHICH RENDERED MACROPHAGES WITH PREFERENTIAL M2 POLARIZATION. THEREFORE, THE KDM2A(-/-) MICE WERE HIGHLY PROTECTED FROM HIGH-FAT DIET (HFD)-INDUCED OBESITY, INSULIN RESISTANCE, AND HEPATIC STEATOSIS, AND FEATURED BY THE REDUCED ACCUMULATION OF ADIPOSE TISSUE MACROPHAGES AND REPRESSED CHRONIC INFLAMMATION FOLLOWING HFD CHALLENGE. PARTICULARLY, KDM2A(-/-) MACROPHAGES PROVIDED A MICROENVIRONMENT IN FAVOR OF THERMOGENESIS. UPON HFD OR COLD CHALLENGE, THE KDM2A(-/-) MICE MANIFESTED HIGHER CAPACITY FOR INDUCING ADIPOSE BROWNING AND BEIGING TO PROMOTE ENERGY EXPENDITURE. COLLECTIVELY, OUR FINDINGS DEMONSTRATE THE IMPORTANCE OF KDM2A-MEDIATED H3K36 DEMETHYLATION IN ORCHESTRATING MACROPHAGE POLARIZATION, PROVIDING NOVEL INSIGHT THAT TARGETING KDM2A IN MACROPHAGES COULD BE A VIABLE THERAPEUTIC APPROACH AGAINST OBESITY AND INSULIN RESISTANCE. 2021 20 906 22 CHRONIC EXPOSURE TO ENVIRONMENTAL LEVEL PHENANTHRENE INDUCES NON-OBESITY-DEPENDENT INSULIN RESISTANCE IN MALE MICE. EPIDEMIOLOGICAL EVIDENCE SHOWS THAT THE BODY BURDEN OF POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IS RELATED TO THE DISRUPTION OF GLUCOSE HOMEOSTASIS. HOWEVER, THE CONTRIBUTION OF PAHS TO THE DEVELOPMENT OF DIABETES REMAINS POORLY DOCUMENTED. IN THE CURRENT WORK, MALE KUNMING MICE RECEIVED PHENANTHRENE (PHE) (5, 50, AND 500 NG/KG) BY GAVAGE ADMINISTRATION ONCE EVERY 2 DAYS FOR 28 WEEKS. THE SIGNIFICANT ELEVATION OF HOMEOSTASIS MODEL ASSESSMENT-INSULIN RESISTANCE (HOMA-IR) AND HOMA-BETA CELL, ACCOMPANIED BY HYPERINSULINEMIA, INDICATED THE OCCURRENCE OF INSULIN RESISTANCE. THE SUPPRESSION OF THE INSULIN RECEPTOR SIGNALING PATHWAY IN SKELETAL MUSCLE MIGHT BE RESPONSIBLE FOR GLUCOSE INTOLERANCE. UNDER THE NONOBESE STATE, THE SERUM LEVELS OF RESISTIN, TUMOR NECROSIS FACTOR-ALPHA, AND INTERLEUKIN-6 WERE ELEVATED, WHEREAS THE LEVELS OF ADIPONECTIN WERE REDUCED. THESE CHANGES IN ADIPOCYTOKINE LEVELS WERE CONSISTENT WITH THEIR TRANSCRIPTION IN WHITE ADIPOSE TISSUE. THE PROMOTER METHYLATION LEVELS OF RETN (ENCODING RESISTIN) AND ADIPOQ (ENCODING ADIPONECTIN) WERE INVERSELY CORRELATED WITH THEIR MRNA LEVELS, INDICATING THAT PHE EXPOSURE COULD CAUSE THE DISRUPTION OF ADIPOCYTOKINE SECRETION VIA EPIGENETIC MODIFICATION. THE RESULTS WOULD BE HELPFUL FOR UNDERSTANDING THE PATHOGENESIS IN THE DEVELOPMENT OF T2DM CAUSED BY NONOBESOGENIC POLLUTANTS. 2020