1 2301 109 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 2 4034 27 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 3 4022 29 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 4 701 20 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 5 2754 28 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 6 241 31 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 7 240 30 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 8 6182 33 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 9 6291 25 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 10 3155 22 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 11 1725 28 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 12 5878 26 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 13 6887 29 [ROLE OF METAFLAMMATION AS A SYSTEMIC MANIFESTATION OF METABOLIC DISEASES]. VISCERAL OBESITY AS A COMPONENT OF THE METABOLIC SYNDROME IS CHARACTERIZED BY SYSTEMIC AND LOCAL INFLAMMATION, WHICH CAN BE QUANTIFIED IN ORGANS (METAFLAMMATION). THIS PROCESS CAN BE REGARDED AS A CHRONIC, STERILE, AND LOW-GRADE STATE OF INFLAMMATION WITHOUT INFECTION, TRAUMA, TUMOR OR AUTOIMMUNITY. IT IS CAUSED BY AN INFLAMMATION OF THE VISCERAL ADIPOSE TISSUE (ADIPOSE INFLAMMATION OR ADIPOFLAMMATION) DUE TO ADIPOCYTE HYPERTROPHY AND HYPERPLASIA WITH INCREASED INFILTRATION BY MONOCYTES AND MACROPHAGES. IMPORTANT IS THE PRESENCE OF PROINFLAMMATORY, SO-CALLED POLARIZED M1 MACROPHAGES THAT ARE INDUCED BY INTERFERON GAMMA (IFN-GAMMA) AND LIPOPOLYSACCHARIDES (LPS) WITH SECRETION OF INTERLEUKIN (IL)-6, TUMOR NECROSIS FACTOR (TNF) AND IL?1. IN CONTRAST, THE ANTI-INFLAMMATORY, SO-CALLED POLARIZED M2 MACROPHAGES INDUCED BY IL?4 AND IL-13 WITH SECRETION OF IL?8 AND IL-10 DECREASE. IN ADDITION, THE SECRETED ADIPOKINE PATTERN CHANGES FROM ANTI-INFLAMMATORY TO PROINFLAMMATORY. ADIPOCYTE NECROSIS, LOCAL HYPOXIA, DYSREGULATED AUTOPHAGY, ACTIVATION OF INFLAMMASOMES, MODULATION OF TOLL-LIKE RECEPTORS, AND EPIGENETIC FACTORS PLAY A COMPLEX ROLE. THIS MECHANISM RESULTS IN LOCAL INSULIN RESISTANCE AND SUBSEQUENTLY A SYSTEMIC INSULIN RESISTANCE OF PERIPHERAL ORGANS AS WELL AS A SPILLOVER OF LOCAL MEDIATORS OF INFLAMMATION INTO THE SYSTEMIC CIRCULATION (MEASURED AS OBESITY C?REACTIVE PROTEIN, CRP). THE ACTIVATION OF INFLAMMATORY SIGNAL TRANSDUCTION CASCADES LEADS TO INHIBITORY PHOSPHORYLATION OF THE INSULIN SIGNALING PATHWAY AND A WEAKENING OF THE EFFECT OF INSULIN. IN PARALLEL, ECTOPIC LIPID ACCUMULATION OCCURS IN THE LIVER, MUSCULATURE, PANCREAS, PERICARDIUM AND LUNGS. DIACYLGLYCEROL (DAG) ACTIVATES SPECIFIC ISOFORMS OF PROTEIN KINASE C (EPSILON IN THE LIVER AND TAU IN THE MUSCULATURE), WHICH IN TURN LEAD TO INHIBITION OF THE INSULIN SIGNALING PATHWAY. INSULIN RESISTANCE IN OBESITY AND TYPE 2 DIABETES MELLITUS IS AN INFLAMMATORY DISEASE. THE AIM OF FUTURE TRANSLATIONAL APPROACHES IS AN ANTI-INFLAMMATORY, MOLECULARLY INDIVIDUALIZED (PRECISION MEDICINE) TREATMENT IN ADIPOSE TISSUE (TARGETED THERAPY) AND IN ORGANS OF INSULIN RESISTANCE. 2023 14 4271 27 MICROBIAL DYSBIOSIS-INDUCED OBESITY: ROLE OF GUT MICROBIOTA IN HOMOEOSTASIS OF ENERGY METABOLISM. THE GLOBAL OBESITY EPIDEMIC HAS NECESSITATED THE SEARCH FOR BETTER INTERVENTION STRATEGIES INCLUDING THE EXPLOITATION OF THE HEALTH BENEFITS OF SOME GUT MICROBIOTA AND THEIR METABOLIC PRODUCTS. THEREFORE, WE EXAMINED THE GUT MICROBIAL COMPOSITION AND MECHANISMS OF INTERACTION WITH THE HOST IN RELATION TO HOMOEOSTATIC ENERGY METABOLISM AND PATHOPHYSIOLOGY OF DYSBIOSIS-INDUCED METABOLIC INFLAMMATION AND OBESITY. WE ALSO DISCUSSED THE EUBIOTIC, HEALTH-PROMOTING EFFECTS OF PROBIOTICS AND PREBIOTICS AS WELL AS EPIGENETIC MODIFICATIONS ASSOCIATED WITH GUT MICROBIAL DYSBIOSIS AND RISK OF OBESITY. HIGH-FAT/CARBOHYDRATE DIET PROGRAMMES THE GUT MICROBIOTA TO ONE PREDOMINATED BY FIRMICUTES (CLOSTRIDIUM), PREVOTELLA AND METHANOBREVIBACTER BUT DEFICIENT IN BENEFICIAL GENERA/SPECIES SUCH AS BACTEROIDES, BIFIDOBACTERIUM, LACTOBACILLUS AND AKKERMANSIA. ALTERED GUT MICROBIOTA IS ASSOCIATED WITH DECREASED EXPRESSION OF SCFA THAT MAINTAIN INTESTINAL EPITHELIAL BARRIER INTEGRITY, REDUCE BACTERIAL TRANSLOCATION AND INFLAMMATION AND INCREASE EXPRESSION OF HUNGER-SUPPRESSING HORMONES. REDUCED AMOUNTS OF BENEFICIAL MICRO-ORGANISMS ALSO INHIBIT FASTING-INDUCED ADIPOCYTE FACTOR EXPRESSION LEADING TO DYSLIPIDAEMIA. A LOW-GRADE CHRONIC INFLAMMATION (METABOLIC ENDOTOXAEMIA) ENSUES WHICH CULMINATES IN OBESITY AND ITS CO-MORBIDITIES. THE SYNERGY OF HIGH-FAT DIET AND DYSBIOTIC GUT MICROBIOTA INITIATES A RECIPE THAT EPIGENETICALLY PROGRAMMES THE HOST FOR INCREASED ADIPOSITY AND POOR GLYCAEMIC CONTROL. INTERESTINGLY, THESE OBESOGENIC MECHANISTIC PATHWAYS THAT ARE TRANSMITTABLE FROM ONE GENERATION TO ANOTHER CAN BE MODULATED THROUGH THE ADMINISTRATION OF PROBIOTICS, PREBIOTICS AND SYNBIOTICS. THOUGH THE INFLUENCE OF GUT MICROBIOTA ON THE RISK OF OBESITY AND SEVERAL INTERVENTION STRATEGIES HAVE BEEN EXTENSIVELY DEMONSTRATED IN ANIMAL MODELS, APPLICATION IN HUMANS STILL REQUIRES FURTHER ROBUST INVESTIGATION. 2020 15 992 25 CHRONIC STRESS AND ADIPOSE TISSUE IN THE ANOREXIC STATE: ENDOCRINE AND EPIGENETIC MECHANISMS. ALTHOUGH ADIPOSE TISSUE METABOLISM IN OBESITY HAS BEEN WIDELY STUDIED, THERE IS LIMITED RESEARCH ON THE ANOREXIC STATE, WHERE THE ENDOCRINE SYSTEM IS DISRUPTED BY REDUCED ADIPOSE TISSUE MASS AND THERE ARE DEPOT-SPECIFIC CHANGES IN ADIPOCYTE TYPE AND FUNCTION. STRESS EXPOSURE AT DIFFERENT STAGES OF LIFE CAN ALTER THE BALANCE BETWEEN ENERGY INTAKE AND EXPENDITURE AND THEREBY CONTRIBUTE TO THE PATHOGENESIS OF ANOREXIA NERVOSA. THIS REVIEW INTEGRATES INFORMATION FROM HUMAN CLINICAL TRIALS TO DESCRIBE ENDOCRINE, GENETIC AND EPIGENETIC ASPECTS OF ADIPOSE TISSUE PHYSIOLOGY IN THE ANOREXIC CONDITION. CHANGES IN THE HYPOTHALAMUS-PITUITARY-THYROID, -ADRENAL, AND -GONADAL AXES AND THEIR RELATIONSHIPS TO APPETITE REGULATION AND ADIPOCYTE FUNCTION ARE DISCUSSED. BECAUSE OF THE ROLE OF STRESS IN TRIGGERING OR MAGNIFYING ANOREXIA, AND THE DYNAMIC BUT ALSO PERSISTENT NATURE OF ENVIRONMENTALLY-INDUCED EPIGENETIC MODIFICATIONS, EPIGENETICS IS LIKELY THE LINK BETWEEN STRESS AND LONG-TERM CHANGES IN THE ENDOCRINE SYSTEM THAT DISRUPT HOMOEOSTATIC FOOD INTAKE AND ADIPOSE TISSUE METABOLISM. HEREIN, WE FOCUS ON THE ADIPOCYTE AND CHANGES IN ITS FUNCTION, INCLUDING ALTERATIONS REINFORCED BY ENDOCRINE DISTURBANCE AND DYSFUNCTIONAL ADIPOKINE REGULATION. THIS INFORMATION IS CRITICAL BECAUSE OF THE POOR UNDERSTANDING OF ANOREXIC PATHOPHYSIOLOGY, DUE TO THE LACK OF SUITABLE RESEARCH MODELS, AND THE COMPLEXITY OF GENETIC AND ENVIRONMENTAL INTERACTIONS. 2020 16 3359 26 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 17 2699 28 EXCESS BODY WEIGHT: NOVEL INSIGHTS INTO ITS ROLES IN OBESITY COMORBIDITIES. EXCESS BODY WEIGHT IS A GLOBAL HEALTH PROBLEM DUE TO SEDENTARY LIFESTYLE AND UNHEALTHY DIET, AFFECTING 2 BILLION POPULATION WORLDWIDE. OBESITY IS A MAJOR RISK FACTOR FOR METABOLIC DISEASES. NOTABLY, THE METABOLIC RISK OF OBESITY LARGELY DEPENDS ON BODY WEIGHT DISTRIBUTION, OF WHICH VISCERAL ADIPOSE TISSUES BUT NOT SUBCUTANEOUS FATS ARE CLOSELY ASSOCIATED WITH OBESITY COMORBIDITIES, INCLUDING TYPE 2 DIABETES, NON-ALCOHOLIC FATTY LIVER DISEASE, CARDIOVASCULAR DISEASE AND CERTAIN TYPES OF CANCER. LATEST MULTI-OMICS AND MECHANISTICAL STUDIES REPORTED THE CRUCIAL INVOLVEMENT OF GENETIC AND EPIGENETIC ALTERATIONS, ADIPOKINES DYSREGULATION, IMMUNITY CHANGES, IMBALANCE OF WHITE AND BROWN ADIPOSE TISSUES, AND GUT MICROBIAL DYSBIOSIS IN MEDIATING THE PATHOGENIC ASSOCIATION BETWEEN VISCERAL ADIPOSE TISSUES AND COMORBIDITIES. IN THIS REVIEW, WE EXPLORE THE EPIDEMIOLOGY OF EXCESS BODY WEIGHT AND THE UP-TO-DATE MECHANISM OF HOW EXCESS BODY WEIGHT AND OBESITY LEAD TO CHRONIC COMPLICATIONS. WE ALSO EXAMINE THE UTILIZATION OF VISCERAL FAT MEASUREMENT AS AN ACCURATE CLINICAL PARAMETER FOR RISK ASSESSMENT IN HEALTHY INDIVIDUALS AND CLINICAL OUTCOME PREDICTION IN OBESE SUBJECTS. IN ADDITION, CURRENT APPROACHES FOR THE PREVENTION AND TREATMENT OF EXCESS BODY WEIGHT AND ITS RELATED METABOLIC COMORBIDITIES ARE FURTHER DISCUSSED. 2023 18 996 32 CHRONIC STRESS, EPIGENETICS, AND ADIPOSE TISSUE METABOLISM IN THE OBESE STATE. IN OBESITY, ENDOCRINE AND METABOLIC PERTURBATIONS, INCLUDING THOSE INDUCED BY CHRONIC ACTIVATION OF THE HYPOTHALAMUS-PITUITARY-ADRENAL AXIS, ARE ASSOCIATED WITH THE ACCUMULATION OF ADIPOSE TISSUE AND INFLAMMATION. SUCH CHANGES ARE ATTRIBUTABLE TO A COMBINATION OF GENETIC AND EPIGENETIC FACTORS THAT ARE INFLUENCED BY THE ENVIRONMENT AND EXACERBATED BY CHRONIC ACTIVATION OF THE HYPOTHALAMUS-PITUITARY-ADRENAL AXIS. STRESS EXPOSURE AT DIFFERENT LIFE STAGES CAN ALTER ADIPOSE TISSUE METABOLISM DIRECTLY THROUGH EPIGENETIC MODIFICATION OR INDIRECTLY THROUGH THE MANIPULATION OF HYPOTHALAMIC APPETITE REGULATION, AND THEREBY CONTRIBUTE TO ENDOCRINE CHANGES THAT FURTHER DISRUPT WHOLE-BODY ENERGY BALANCE. THIS REVIEW SYNTHESIZES CURRENT KNOWLEDGE, WITH AN EMPHASIS ON HUMAN CLINICAL TRIALS, TO DESCRIBE METABOLIC CHANGES IN ADIPOSE TISSUE AND ASSOCIATED ENDOCRINE, GENETIC AND EPIGENETIC CHANGES IN THE OBESE STATE. IN PARTICULAR, WE DISCUSS EPIGENETIC CHANGES INDUCED BY STRESS EXPOSURE AND THEIR CONTRIBUTION TO APPETITE AND ADIPOCYTE DYSFUNCTION, WHICH COLLECTIVELY PROMOTE THE PATHOGENESIS OF OBESITY. SUCH KNOWLEDGE IS CRITICAL FOR PROVIDING FUTURE DIRECTIONS OF METABOLISM RESEARCH AND TARGETS FOR TREATING METABOLIC DISORDERS. 2020 19 4307 31 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 20 4455 25 MOLECULAR MECHANISMS FOR THE VICIOUS CYCLE BETWEEN INSULIN RESISTANCE AND THE INFLAMMATORY RESPONSE IN OBESITY. THE COMPREHENSIVE ANABOLIC EFFECTS OF INSULIN THROUGHOUT THE BODY, IN ADDITION TO THE CONTROL OF GLYCEMIA, INCLUDE ENSURING LIPID HOMEOSTASIS AND ANTI-INFLAMMATORY MODULATION, ESPECIALLY IN ADIPOSE TISSUE (AT). THE PREVALENCE OF OBESITY, DEFINED AS A BODY MASS INDEX (BMI) >/= 30 KG/M(2), HAS BEEN INCREASING WORLDWIDE ON A PANDEMIC SCALE WITH ACCOMPANYING SYNDEMIC HEALTH PROBLEMS, INCLUDING GLUCOSE INTOLERANCE, INSULIN RESISTANCE (IR), AND DIABETES. IMPAIRED TISSUE SENSITIVITY TO INSULIN OR IR PARADOXICALLY LEADS TO DISEASES WITH AN INFLAMMATORY COMPONENT DESPITE HYPERINSULINEMIA. THEREFORE, AN EXCESS OF VISCERAL AT IN OBESITY INITIATES CHRONIC LOW-GRADE INFLAMMATORY CONDITIONS THAT INTERFERE WITH INSULIN SIGNALING VIA INSULIN RECEPTORS (INSRS). MOREOVER, IN RESPONSE TO IR, HYPERGLYCEMIA ITSELF STIMULATES A PRIMARILY DEFENSIVE INFLAMMATORY RESPONSE ASSOCIATED WITH THE SUBSEQUENT RELEASE OF NUMEROUS INFLAMMATORY CYTOKINES AND A REAL THREAT OF ORGAN FUNCTION DETERIORATION. IN THIS REVIEW, ALL COMPONENTS OF THIS VICIOUS CYCLE ARE CHARACTERIZED WITH PARTICULAR EMPHASIS ON THE INTERPLAY BETWEEN INSULIN SIGNALING AND BOTH THE INNATE AND ADAPTIVE IMMUNE RESPONSES RELATED TO OBESITY. INCREASED VISCERAL AT ACCUMULATION IN OBESITY SHOULD BE CONSIDERED THE MAIN ENVIRONMENTAL FACTOR RESPONSIBLE FOR THE DISRUPTION IN THE EPIGENETIC REGULATORY MECHANISMS IN THE IMMUNE SYSTEM, RESULTING IN AUTOIMMUNITY AND INFLAMMATION. 2023