1 3155 100 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 2 685 19 BRAIN-DERIVED NEUROTROPHIC FACTOR INVOLVED EPIGENETIC REPRESSION OF UGT2B7 IN COLORECTAL CARCINOMA: A MECHANISM TO ALTER MORPHINE GLUCURONIDATION IN TUMOR. URIDINE DIPHOSPHATE-GLUCURONOSYLTRANSFERASE (UGT) 2B7, AS ONE OF SIGNIFICANT DRUG ENZYMES, IS RESPONSIBLE ON THE GLUCURONIDATION OF ABUNDANT ENDOBIOTICS OR XENOBIOTICS. WE HERE REPORT THAT IT IS MARKEDLY REPRESSED IN THE TUMOR TISSUES OF COLORECTAL CARCINOMA (CRC) PATIENTS. ACCORDINGLY, MORPHINE IN CRC CELLS WILL STIMULATE THE EXPRESSION OF ITS MAIN METABOLIC ENZYME, UGT2B7 DURING TOLERANCE GENERATION BY ACTIVATING THE POSITIVE SIGNALS IN HISTONE 3, ESPECIALLY FOR TRIMETHYLATED LYSINE 27 (H3K4ME3) AND ACETYLATED LYSINE 4 (H3K27AC). FURTHER STUDY REVEALS THAT BRAIN-DERIVED NEUTROPHILIC FACTOR (BDNF), A SECRETORY NEUROTROPHIN, ENRICHED IN CRC CAN INTERACT AND INHIBIT UGT2B7 BY PRIMARILY BLOCKING THE POSITIVE SIGNALS OF H3K4ME3 AS WELL AS ACTIVATING H3K27AC ON THE PROMOTER REGION OF UGT2B7. MEANWHILE, BDNF REPRESSION ATTRIBUTES TO THE SENSITIZATIONS OF MAIN CORE FACTORS IN POLY-COMB REPRESSIVE COMPLEX (PRC) 1 RATHER THAN PRC2 AS THE REASON OF THE DEPRESSION OF SUZ12 IN THE LATER COMPLEX. BESIDES THAT, THE PRODUCTIONS OF TWO MAIN MORPHINE GLUCURONIDES ARE BOTH INCREASED IN THE BDNF DEFICIENT OR TSA AND BIX-01294 TREATED MORPHINE TOLERANCE-LIKE HCT-116 CELLS. ON THE SAME CONDITION, ACTIVE METABOLITE, MORPHINE-6-GLUCURONIDE (M6G) WAS ACCUMULATED MORE THAN INACTIVE M3G. OUR FINDINGS IMPLY THAT ENZYMATIC ACTIVITY ENHANCEMENT AND SUBSTRATE REGIOSELECTIVE CATALYSIS ALTERATION OF UGT2B7 MAY RELEASE MORPHINE TOLERANCE UNDER THE CURE OF TUMOR-INDUCED PAIN. 2017 3 4928 21 PARP-1 AND PARP-2 ACTIVITY IN CANCER-INDUCED CACHEXIA: POTENTIAL THERAPEUTIC IMPLICATIONS. SKELETAL MUSCLE DYSFUNCTION AND MASS LOSS IS A CHARACTERISTIC FEATURE IN PATIENTS WITH CHRONIC DISEASES INCLUDING CANCER AND ACUTE CONDITIONS SUCH AS CRITICAL ILLNESS. MAINTENANCE OF AN ADEQUATE MUSCLE MASS IS CRUCIAL FOR THE PATIENTS' PROGNOSIS IRRESPECTIVE OF THE UNDERLYING CONDITION. MOREOVER, AGING-RELATED SARCOPENIA MAY FURTHER AGGRAVATE THE MUSCLE WASTING PROCESS ASSOCIATED WITH CHRONIC DISEASES AND CANCER. POLY(ADENOSINE DIPHOSPHATE-RIBOSE) POLYMERASE (PARP) ACTIVATION HAS BEEN DEMONSTRATED TO CONTRIBUTE TO THE PATHOPHYSIOLOGY OF MUSCLE MASS LOSS AND DYSFUNCTION IN ANIMAL MODELS OF CANCER-INDUCED CACHEXIA. GENETIC INHIBITION OF PARP ACTIVITY ATTENUATED THE DELETERIOUS EFFECTS SEEN ON DEPLETED MUSCLES IN MOUSE MODELS OF ONCOLOGIC CACHEXIA. IN THE PRESENT MINIREVIEW THE MECHANISMS WHEREBY PARP ACTIVITY INHIBITION MAY IMPROVE MUSCLE MASS AND PERFORMANCE IN MODELS OF CANCER-INDUCED CACHEXIA ARE DISCUSSED. SPECIFICALLY, THE BENEFICIAL EFFECTS OF INHIBITION OF PARP ACTIVITY ON ATTENUATION OF INCREASED OXIDATIVE STRESS, PROTEIN CATABOLISM, POOR MUSCLE ANABOLISM AND MITOCHONDRIAL CONTENT AND EPIGENETIC MODULATION OF MUSCLE PHENOTYPE ARE REVIEWED IN THIS ARTICLE. FINALLY, THE POTENTIAL THERAPEUTIC STRATEGIES OF PHARMACOLOGICAL PARP ACTIVITY INHIBITION FOR THE TREATMENT OF CANCER-INDUCED CACHEXIA ARE ALSO BEING DESCRIBED IN THIS REVIEW. 2018 4 1067 20 CLINICAL UTILITY OF PDSS2 EXPRESSION TO STRATIFY PATIENTS AT RISK FOR RECURRENCE OF HEPATOCELLULAR CARCINOMA. IDENTIFICATION OF NOVEL GENETIC AND EPIGENETIC ALTERATIONS IS REQUIRED FOR OPTIMAL STRATIFICATION OF PATIENTS WITH HEPATOCELLULAR CARCINOMA (HCC) AT RISK FOR RECURRENCE AND ADVERSE PROGNOSIS. COENZYME Q10 (COQ10), WHICH MEDIATES APOPTOSIS, IS SYNTHESIZED BY PRENYL DIPHOSPHATE SYNTHASE SUBUNIT 2 (PDSS2). IN THE PRESENT STUDY WE EVALUATED THE CLINICAL SIGNIFICANCE AND REGULATORY MECHANISMS OF PDSS2 EXPRESSION IN HCC. PDSS2 EXPRESSION LEVELS AND THOSE OF GENES ENCODING POTENTIALLY INTERACTING PROTEINS AS WELL AS THE METHYLATION STATUS OF THE PDSS2 PROMOTER REGION WERE ANALYZED IN HCC CELL LINES. PDSS2 MRNA LEVELS IN 151 PAIRS OF RESECTED SPECIMENS WERE DETERMINED TO EVALUATE THE ASSOCIATION OF PDSS2 EXPRESSION AND CLINICOPATHOLOGICAL FACTORS. THE EXPRESSION AND DISTRIBUTION OF PDSS2 WERE DETERMINED USING IMMUNOHISTOCHEMISTRY. PDSS2 MRNA EXPRESSION WAS DECREASED IN SIX OF NINE HCC CELL LINES AND SIGNIFICANTLY CORRELATED WITH THOSE OF HEPATOCYTE NUCLEAR FACTOR 4ALPHA. PDSS2 TRANSCRIPTION IN HCC CELLS WITH DECREASED PDSS2 EXPRESSION ACCOMPANYING HYPERMETHYLATION WAS REACTIVATED AFTER TREATING THESE CELLS WITH A METHYLATION INHIBITOR. MEAN EXPRESSION LEVELS OF PDSS2 MRNA RELATIVE TO THAT OF UNINVOLVED LIVER DIMINISHED GRADUALLY IN THE ORDER OF CHRONIC HEPATITIS TO CIRRHOSIS, AND EACH WAS SIGNIFICANTLY HIGHER THAN THOSE OF HCCS. PDSS2 AND PDSS2 MRNA LEVELS WERE CONSISTENT. DECREASED PDSS2 MRNA LEVELS WERE DETECTED IN HCC TISSUES OF 56 PATIENTS, CORRELATED WITH SHORTER DISEASE-SPECIFIC SURVIVAL, AND WAS IDENTIFIED AS AN INDEPENDENT PROGNOSTIC FACTOR. PDSS2 IS A PUTATIVE TUMOR SUPPRESSOR, AND PROMOTER HYPERMETHYLATION IS A KEY REGULATORY MECHANISM IN HCC. DECREASED LEVELS OF PDSS2 MRNA EXPRESSION MAY REPRESENT A NOVEL BIOMARKER OF HCC. 2014 5 1944 18 EPIGALLOCATECHIN-3-GALLATE AND BIX-01294 HAVE DIFFERENT IMPACT ON EPIGENETICS AND SENESCENCE MODULATION IN ACUTE AND CHRONIC MYELOID LEUKEMIA CELLS. MYELOID LEUKEMIA TREATMENT IS QUITE SUCCESSFUL NOWADAYS; NEVERTHELESS THE DEVELOPMENT OF NEW THERAPIES IS STILL NECESSARY. IN THE PRESENT STUDY, WE INVESTIGATED THE POTENTIAL OF EPIGENETIC MODULATORS EGCG (EPIGALLOCATECHIN-3-GALLATE) AND BIX-01294 (N-(1-BENZYLPIPERIDIN-4-YL)-6,7-DIMETHOXY-2-(4-METHYL-1,4-DIAZEPAN-1-YL)QUINAZOLIN-4-AMINE) TO ALTER EPIGENETIC STATE AND CAUSE CELLULAR SENESCENCE IN ACUTE AND CHRONIC MYELOID LEUKEMIA NB4 AND K562 CELLS. WE HAVE SHOWN THAT AFTER LEUKEMIA CELL TREATMENT WITH EGCG AND BIX-01294 THE PROLIFERATION AND SURVIVAL WERE INHIBITED OF BOTH CELL LINES; HOWEVER, ONLY NB4 CELLS UNDERWENT APOPTOSIS. BOTH EPIGENETIC MODULATORS CAUSED CELL CYCLE ARREST IN G0/G1 PHASE AS ASSESSED BY RT-QPCR (P53, P21, RB) AND FLOW CYTOMETRY ANALYSIS. INCREASED LEVELS OF ATM, HMGA2, PHOSPHORYLATED ATM, AND SA-BETA-GALACTOSIDASE STAINING INDICATED THAT EGCG CAUSED CELLULAR SENESCENCE, WHEREAS BIX-01294 DID NOT. IMMUNOBLOT ANALYSIS OF EPIGENETIC PLAYERS DNMT1, HP1ALPHA, H3K9ME3, EZH2, AND SUZ12 DEMONSTRATED BENEFICIAL EPIGENETIC MODULATION BY BOTH AGENTS WITH EXCEPTION OF MAINLY NO EPIGENETIC CHANGES CAUSED IN K562 CELLS BY EGCG. THEREFORE, WE SUGGEST EGCG AS A PROMISING EPIGENETIC MODULATOR FOR ACUTE PROMYELOCYTIC LEUKEMIA THERAPY AND AS A POTENTIAL CELLULAR SENESCENCE INDUCER IN BOTH ACUTE AND CHRONIC MYELOID LEUKEMIA TREATMENT, WHEREAS BIX-01294 COULD BE BENEFICIAL AS AN EPIGENETIC MODIFIER FOR BOTH MYELOID LEUKEMIAS TREATMENT. 2018 6 4356 22 MIR-30A-5P PROMOTES GLOMERULAR PODOCYTE APOPTOSIS VIA DNMT1-MEDIATED HYPERMETHYLATION UNDER HYPERHOMOCYSTEINEMIA. ABNORMAL ELEVATION OF HOMOCYSTEINE (HCY) LEVEL IS CLOSELY RELATED TO THE DEVELOPMENT AND PROGRESSION OF CHRONIC KIDNEY DISEASE (CKD), WITH THE MOLECULAR MECHANISMS THAT ARE NOT FULLY ELUCIDATED. GIVEN THE DEMONSTRATION THAT MIR-30A-5P IS SPECIFICALLY EXPRESSED IN GLOMERULAR PODOCYTES, IN THE PRESENT STUDY WE AIMED TO INVESTIGATE THE ROLE AND POTENTIAL UNDERLYING MECHANISM OF MIR-30A-5P IN GLOMERULAR PODOCYTE APOPTOSIS INDUCED BY HCY. WE FOUND THAT ELEVATED HCY DOWNREGULATES MIR-30A-5P EXPRESSION IN THE MICE AND HCY-TREATED PODOCYTES, AND MIR-30A-5P DIRECTLY TARGETS THE 3'-UNTRANSLATED REGION (3'-UTR) OF THE FORKHEAD BOX A1 (FOXA1) AND OVEREXPRESSION OF MIR-30A-5P INHIBITS FOXA1 EXPRESSION. BY NMS-PCR AND MASSARRAY QUANTITATIVE METHYLATION ANALYSIS, WE SHOWED THE INCREASED DNA METHYLATION LEVEL OF MIR-30A-5P PROMOTER BOTH AND . MEANWHILE, DUAL-LUCIFERASE REPORTER ASSAY SHOWED THAT THE REGION BETWEEN --1400 AND --921 BP OF MIR-30A-5P PROMOTER IS A POSSIBLE REGULATORY ELEMENT FOR ITS TRANSCRIPTION. MECHANISTIC STUDIES INDICATED THAT DNA METHYLTRANSFERASE ENZYME 1 (DNMT1) IS THE KEY REGULATOR OF MIR-30A-5P, WHICH IN TURN ENHANCES MIR-30A-5P PROMOTER METHYLATION LEVEL AND THEREBY INHIBITS ITS EXPRESSION. TAKEN TOGETHER, OUR RESULTS REVEALED THAT EPIGENETIC MODIFICATION OF MIR-30A-5P IS INVOLVED IN GLOMERULAR PODOCYTE INJURY INDUCED BY HCY, PROVIDING A DIAGNOSTIC MARKER CANDIDATE AND NOVEL THERAPEUTIC TARGET IN CKD INDUCED BY HCY. 2022 7 1298 20 DECREASED NUCLEAR RECEPTOR ACTIVITY AND EPIGENETIC MODULATION ASSOCIATES WITH DOWN-REGULATION OF HEPATIC DRUG-METABOLIZING ENZYMES IN CHRONIC KIDNEY DISEASE. PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD) REQUIRE MANY MEDICATIONS. CYP2C AND CYP3A DRUG-METABOLIZING ENZYMES PLAY A CRITICAL ROLE IN DETERMINING THE PHARMACOKINETICS OF THE MAJORITY OF PRESCRIBED MEDICATIONS. THESE ENZYMES ARE TRANSCRIPTIONALLY REGULATED BY THE NUCLEAR RECEPTORS PREGNANE X RECEPTOR (PXR) AND HEPATIC NUCLEAR FACTOR 4ALPHA (HNF-4ALPHA). EXPRESSION OF CYP2C AND CYP3A IS DECREASED IN CKD; HOWEVER, THE MECHANISMS BY WHICH THIS OCCURS IS UNKNOWN. WE INDUCED CKD IN RATS BY 5/6 NEPHRECTOMY AND USED CHROMATIN IMMUNOPRECIPITATION (CHIP) TO DETERMINE NUCLEAR RECEPTOR- AND EPIGENETIC ALTERATION-MEDIATED DIFFERENCES IN THE PROMOTER REGION OF THE CYP2C AND CYP3A GENES. RNA POLYMERASE II AND HNF-4ALPHA BINDING WAS DECREASED 76 AND 57% IN THE CYP2C11 PROMOTOR AND 71 AND 77% IN THE CYP3A2 PROMOTER, RESPECTIVELY (P<0.05). CHIP ALSO REVEALED A 57% DECREASE IN PXR BINDING TO THE CYP3A2 PROMOTER IN CKD RATS (P<0.05). THE DECREASE IN PXR AND HNF-4ALPHA BINDING WAS ACCOMPANIED BY DIMINISHED HISTONE 4 ACETYLATION IN THE CYP3A2 PROMOTER (48%) AND HISTONE 3 ACETYLATION IN THE CYP2C11 (77%) AND CYP3A2 (77%) PROMOTER LOCI FOR NUCLEAR RECEPTOR ACTIVATION (P<0.05). THIS STUDY SUGGESTS THAT DECREASED NUCLEAR RECEPTOR BINDING AND HISTONE ACETYLATION MAY CONTRIBUTE TO THE MECHANISM OF DRUG-METABOLIZING ENZYME DOWN-REGULATION AND ALTERED PHARMACOKINETICS IN CKD. 2014 8 5064 22 PHOSPHORYLATION OF RELA/P65 PROMOTES DNMT-1 RECRUITMENT TO CHROMATIN AND REPRESSES TRANSCRIPTION OF THE TUMOR METASTASIS SUPPRESSOR GENE BRMS1. THE MAJORITY OF PATIENTS WITH LUNG CANCER PRESENT WITH METASTATIC DISEASE. CHRONIC INFLAMMATION AND SUBSEQUENT ACTIVATION OF NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) HAVE BEEN ASSOCIATED WITH THE DEVELOPMENT OF CANCERS. THE RELA/P65 SUBUNIT OF NF-KAPPAB IS TYPICALLY ASSOCIATED WITH TRANSCRIPTIONAL ACTIVATION. IN THIS REPORT WE SHOW THAT RELA/P65 CAN FUNCTION AS AN ACTIVE TRANSCRIPTIONAL REPRESSOR THROUGH ENHANCED METHYLATION OF THE BRMS1 (BREAST CANCER METASTASIS SUPPRESSOR 1) METASTASIS SUPPRESSOR GENE PROMOTER VIA DIRECT RECRUITMENT OF DNMT-1 (DNA (CYTOSINE-5)-METHYLTRANSFERASE 1) TO CHROMATIN IN RESPONSE TO TUMOR NECROSIS FACTOR (TNF). TNF-MEDIATED PHOSPHORYLATION OF S276 ON RELA/P65 IS REQUIRED FOR RELA/P65-DNMT-1 INTERACTIONS, CHROMATIN LOADING OF DNMT-1 AND SUBSEQUENT BRMS1 PROMOTER METHYLATION AND TRANSCRIPTIONAL REPRESSION. THE ABILITY OF RELA/P65 TO FUNCTION AS AN ACTIVE TRANSCRIPTIONAL REPRESSOR IS PROMOTER SPECIFIC, AS THE NF-KAPPAB-REGULATED GENE CIAP2 (CELLULAR INHIBITOR OF APOPTOSIS 2) IS TRANSCRIPTIONALLY ACTIVATED WHEREAS BRMS1 IS REPRESSED UNDER IDENTICAL CONDITIONS. SMALL-MOLECULE INHIBITION OF EITHER OF THE MINIMAL INTERACTING DOMAINS BETWEEN RELA/P65-DNMT-1 AND RELA/P65-BRMS1 PROMOTER ABROGATES BRMS1 METHYLATION AND ITS TRANSCRIPTIONAL REPRESSION. THE ABILITY OF RELA/P65 TO DIRECTLY RECRUIT DNMT-1 TO CHROMATIN, RESULTING IN PROMOTER-SPECIFIC METHYLATION AND TRANSCRIPTIONAL REPRESSION OF TUMOR METASTASIS SUPPRESSOR GENE BRMS1, HIGHLIGHTS A NEW MECHANISM THROUGH WHICH NF-KAPPAB CAN REGULATE METASTATIC DISEASE, AND OFFERS A POTENTIAL TARGET FOR NEWER-GENERATION EPIGENETIC ONCOPHARMACEUTICALS. 2012 9 240 42 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 10 2372 20 EPIGENETIC REGULATION OF THE IL-13-INDUCED HUMAN EOTAXIN-3 GENE BY CREB-BINDING PROTEIN-MEDIATED HISTONE 3 ACETYLATION. THE ETIOLOGY OF A VARIETY OF CHRONIC INFLAMMATORY DISORDERS HAS BEEN ATTRIBUTED TO THE INTERACTION OF GENETIC AND ENVIRONMENTAL FACTORS. HEREIN, WE IDENTIFIED A LINK BETWEEN EPIGENETIC REGULATION AND IL-13-DRIVEN EOTAXIN-3 IN THE PATHOGENESIS OF CHRONIC ALLERGIC INFLAMMATION. WE FIRST DEMONSTRATED THAT THE CAMP-RESPONSIVE ELEMENT (CRE) SITE IN THE EOTAXIN-3 PROMOTER AFFECTS IL-13-INDUCED EOTAXIN-3 PROMOTER ACTIVITY. FURTHERMORE, THE CRE-BINDING PROTEIN-BINDING PROTEIN (CBP), A HISTONE ACETYLTRANSFERASE, INDUCED BASE-LINE AND IL-13-INDUCED EOTAXIN-3 PROMOTER ACTIVITY. ADDITIONALLY, IL-13 TREATMENT PROMOTED GLOBAL HISTONE 3 ACETYLATION AS WELL AS THE FORMATION OF A COMPLEX CONTAINING CBP AND STAT6 AND THE SUBSEQUENT ACETYLATION OF HISTONE 3 AT THE EOTAXIN-3 PROMOTER. CBP GENE SILENCING DECREASED IL-13-INDUCED TRANSCRIPTION OF EOTAXIN-3. CONVERSELY, INHIBITION OF HISTONE DEACETYLATION INCREASED IL-13-INDUCED EOTAXIN-3 PRODUCTION. CLINICAL STUDIES DEMONSTRATED MARKEDLY INCREASED GLOBAL ACETYLATION OF HISTONE 3 IN THE INFLAMED TISSUE OF PATIENTS WITH ALLERGIC INFLAMMATION. COLLECTIVELY, THESE RESULTS IDENTIFY AN EPIGENETIC MECHANISM INVOLVING CBP AND CHROMATIN REMODELING IN REGULATING IL-13-INDUCED CHEMOKINE TRANSCRIPTION. 2011 11 5675 20 SHIFTS IN PODOCYTE HISTONE H3K27ME3 REGULATE MOUSE AND HUMAN GLOMERULAR DISEASE. HISTONE PROTEIN MODIFICATIONS CONTROL FATE DETERMINATION DURING NORMAL DEVELOPMENT AND DEDIFFERENTIATION DURING DISEASE. HERE, WE SET OUT TO DETERMINE THE EXTENT TO WHICH DYNAMIC CHANGES TO HISTONES AFFECT THE DIFFERENTIATED PHENOTYPE OF ORDINARILY QUIESCENT ADULT GLOMERULAR PODOCYTES. TO DO THIS, WE EXAMINED THE CONSEQUENCES OF SHIFTING THE BALANCE OF THE REPRESSIVE HISTONE H3 LYSINE 27 TRIMETHYLATION (H3K27ME3) MARK IN PODOCYTES. ADRIAMYCIN NEPHROTOXICITY AND SUBTOTAL NEPHRECTOMY (SNX) STUDIES INDICATED THAT DELETION OF THE HISTONE METHYLATING ENZYME EZH2 FROM PODOCYTES DECREASED H3K27ME3 LEVELS AND SENSITIZED MICE TO GLOMERULAR DISEASE. H3K27ME3 WAS ENRICHED AT THE PROMOTER REGION OF THE NOTCH LIGAND JAG1 IN PODOCYTES, AND DEREPRESSION OF JAG1 BY EZH2 INHIBITION OR KNOCKDOWN FACILITATED PODOCYTE DEDIFFERENTIATION. CONVERSELY, INHIBITION OF THE JUMONJI C DOMAIN-CONTAINING DEMETHYLASES JMJD3 AND UTX INCREASED THE H3K27ME3 CONTENT OF PODOCYTES AND ATTENUATED GLOMERULAR DISEASE IN ADRIAMYCIN NEPHROTOXICITY, SNX, AND DIABETES. PODOCYTES IN GLOMERULI FROM HUMANS WITH FOCAL SEGMENTAL GLOMERULOSCLEROSIS OR DIABETIC NEPHROPATHY EXHIBITED DIMINISHED H3K27ME3 AND HEIGHTENED UTX CONTENT. ANALOGOUS TO HUMAN DISEASE, INHIBITION OF JMJD3 AND UTX ABATED NEPHROPATHY PROGRESSION IN MICE WITH ESTABLISHED GLOMERULAR INJURY AND REDUCED H3K27ME3 LEVELS. TOGETHER, THESE FINDINGS INDICATE THAT OSTENSIBLY STABLE CHROMATIN MODIFICATIONS CAN BE DYNAMICALLY REGULATED IN QUIESCENT CELLS AND THAT EPIGENETIC REPROGRAMMING CAN IMPROVE OUTCOMES IN GLOMERULAR DISEASE BY REPRESSING THE REACTIVATION OF DEVELOPMENTAL PATHWAYS. 2018 12 2887 19 GADD45A TRANSCRIPTIONAL INDUCTION ELICITED BY THE AURORA KINASE INHIBITOR MK-0457 IN BCR-ABL-EXPRESSING CELLS IS DRIVEN BY OCT-1 TRANSCRIPTION FACTOR. THE ADVANTAGE OF AURORA KINASE (AK) INHIBITORS IN CHRONIC MYELOID LEUKEMIA (CML) THERAPY MOSTLY ARISES FROM "OFF-TARGET" EFFECTS ON TYROSINE KINASE (TK) ACTIVITY OF WILD TYPE (WT) OR MUTATED BCR-ABL PROTEINS WHICH DRIVE THE DISEASE RESISTANCE TO IMATINIB (IM). WE PROVED THAT THE AK INHIBITOR MK-0457 INDUCES THE GROWTH ARREST DNA DAMAGE-INDUCIBLE (GADD) 45A THROUGH RECRUITMENT OF OCTAMER-BINDING (OCT)-1 TRANSCRIPTION FACTOR AT A CRITICAL PROMOTER REGION FOR GENE TRANSCRIPTION AND COVALENT MODIFICATIONS OF HISTONE H3 (LYSINE 14 ACETYLATION, LYSINE 9 DE-METHYLATION). SUCH EPIGENETIC CHROMATIN MODIFICATIONS MAY DEPICT A GENERAL MECHANISM PROMOTING THE RE-ACTIVATION OF TUMOR SUPPRESSOR GENES SILENCED BY BCR-ABL. 2012 13 5009 25 PERK IS A CRITICAL METABOLIC HUB FOR IMMUNOSUPPRESSIVE FUNCTION IN MACROPHAGES. CHRONIC INFLAMMATION TRIGGERS COMPENSATORY IMMUNOSUPPRESSION TO STOP INFLAMMATION AND MINIMIZE TISSUE DAMAGE. STUDIES HAVE DEMONSTRATED THAT ENDOPLASMIC RETICULUM (ER) STRESS AUGMENTS THE SUPPRESSIVE PHENOTYPES OF IMMUNE CELLS; HOWEVER, THE MOLECULAR MECHANISMS UNDERPINNING THIS PROCESS AND HOW IT LINKS TO THE METABOLIC REPROGRAMMING OF IMMUNOSUPPRESSIVE MACROPHAGES REMAIN ELUSIVE. IN THE PRESENT STUDY, WE REPORT THAT THE HELPER T CELL 2 CYTOKINE INTERLEUKIN-4 AND THE TUMOR MICROENVIRONMENT INCREASE THE ACTIVITY OF A PROTEIN KINASE RNA-LIKE ER KINASE (PERK)-SIGNALING CASCADE IN MACROPHAGES AND PROMOTE IMMUNOSUPPRESSIVE M2 ACTIVATION AND PROLIFERATION. LOSS OF PERK SIGNALING IMPEDED MITOCHONDRIAL RESPIRATION AND LIPID OXIDATION CRITICAL FOR M2 MACROPHAGES. PERK ACTIVATION MEDIATED THE UPREGULATION OF PHOSPHOSERINE AMINOTRANSFERASE 1 (PSAT1) AND SERINE BIOSYNTHESIS VIA THE DOWNSTREAM TRANSCRIPTION FACTOR ATF-4. INCREASED SERINE BIOSYNTHESIS RESULTED IN ENHANCED MITOCHONDRIAL FUNCTION AND ALPHA-KETOGLUTARATE PRODUCTION REQUIRED FOR JMJD3-DEPENDENT EPIGENETIC MODIFICATION. INHIBITION OF PERK SUPPRESSED MACROPHAGE IMMUNOSUPPRESSIVE ACTIVITY AND COULD ENHANCE THE EFFICACY OF IMMUNE CHECKPOINT PROGRAMMED CELL DEATH PROTEIN 1 INHIBITION IN MELANOMA. OUR FINDINGS DELINEATE A PREVIOUSLY UNDESCRIBED CONNECTION BETWEEN PERK SIGNALING AND PSAT1-MEDIATED SERINE METABOLISM CRITICAL FOR PROMOTING IMMUNOSUPPRESSIVE FUNCTION IN M2 MACROPHAGES. 2022 14 6085 31 THE EFFECTS OF ACARBOSE ON CHEMOKINE AND CYTOKINE PRODUCTION IN HUMAN MONOCYTIC THP-1 CELLS. BACKGROUND AND OBJECTIVES: CHRONIC INFLAMMATION INDUCED BY PROINFLAMMATORY CYTOKINES AND CHEMOKINES IS POSTULATED TO BE INVOLVED IN INSULIN RESISTANCE AND BETA-CELL DYSFUNCTION IN TYPE 2 DIABETES MELLITUS (T2DM). ACARBOSE, THE ALPHA-GLUCOSIDASE INHIBITOR, IS AN ORAL ANTIDIABETIC DRUG FOR T2DM. ACARBOSE SUPPRESSES INFLAMMATORY CYTOKINE PRODUCTION IN PATIENTS WITH T2DM, THOUGH THE UNDERLYING MECHANISMS ARE UNCLEAR. IN THE PRESENT STUDY, WE AIMED TO INVESTIGATE THE ANTI-INFLAMMATORY EFFECTS AND THE EXACT MECHANISMS OF ACARBOSE IN HUMAN MONOCYTIC THP-1 CELLS. METHODS: THP-1 CELLS WERE PRETREATED WITH ACARBOSE AND THEN STIMULATED WITH LIPOPOLYSACCHARIDE (LPS). THE LEVELS OF TH1-RELATED CHEMOKINES, INCLUDING INTERFERON-GAMMA-INDUCIBLE PROTEIN-10 (IP-10), MONOCYTE CHEMOATTRACTANT PROTEIN-1 (MCP-1), TH2-RELATED CHEMOKINE MACROPHAGE-DERIVED CHEMOKINE (MDC), AND PROINFLAMMATORY CYTOKINE TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA), WERE DETERMINED BY ENZYME-LINKED IMMUNOSORBENT ASSAY. INTRACELLULAR SIGNALING PATHWAYS WERE EXPLORED BY WESTERN BLOT ANALYSIS AND USING A CHROMATIN IMMUNOPRECIPITATION ASSAY. RESULTS: ACARBOSE SUPPRESSED THE LEVELS OF IP-10, MCP-1, MDC, AND TNF-ALPHA AND DOWNREGULATED PHOSPHORYLATION OF P38, C-JUN N-TERMINAL KINASE (JNK), EXTRACELLULAR SIGNAL-REGULATED KINASE (ERK), AND NUCLEAR FACTOR-KAPPA B-P65 (NF-KAPPAB-P65) IN LPS-STIMULATED THP-1 CELLS. ACARBOSE SUPPRESSED LPS-INDUCED ACETYLATION OF HISTONES H3 (H3) AND H4 IN THE IP-10 AND MCP-1 PROMOTER REGIONS. THESE FINDINGS REVEALED THE SUPPRESSIVE EFFECTS OF ACARBOSE ON IP-10, MCP-1, MDC, AND TNF-ALPHA PRODUCTION IN THP-1 CELLS VIA, AT LEAST PARTIALLY, THE P38, JNK, ERK, AND NF-KAPPAB-P65 PATHWAYS, AS WELL AS THROUGH EPIGENETIC REGULATION VIA HISTONE H3 AND H4 ACETYLATION. CONCLUSION: OUR STUDY POINTS TO THE THERAPEUTIC ANTI-INFLAMMATORY POTENTIAL OF ACARBOSE. 2019 15 6519 20 TRANSCRIPTIONAL AND EPIGENETIC REGULATION OF INTERLEUKIN-2 GENE IN ACTIVATED T CELLS BY MORPHINE. CHRONIC MORPHINE INHIBITS INTERLEUKIN-2 (IL-2) AT BOTH THE TRANSCRIPTIONAL AND PROTEIN SYNTHESIS LEVELS. THE MOLECULAR MECHANISMS BY WHICH MORPHINE DECREASES IL-2 ARE NOT FULLY UNDERSTOOD. THE PRODUCTION OF IL-2 IS TIGHTLY REGULATED BY SEVERAL TRANSCRIPTION FACTORS THAT BIND TO THE IL-2 PROMOTER. HEREIN, WE SHOW THAT CHRONIC MORPHINE TREATMENT RESULTS IN AN INCREASE IN CAMP LEVELS WITH A CONCURRENT UP-REGULATION OF THE CAMP INDUCIBLE REPRESSOR INDUCIBLE CAMP EARLY REPRESSOR (ICER)/CAMP RESPONSE ELEMENT MODULATOR (CREM) AND DOWN-REGULATION OF P-CAMP-RESPONSE ELEMENT-BINDING PROTEIN (CREB) IN ACTIVATED T CELLS. FURTHERMORE, ICER COMPETES FOR P-CREB BINDING TO THE CAMP-RESPONSIVE ELEMENTS (CRES) SITE. THIS LEADS TO THE UNCOUPLING OF CBP/P300 THEREBY ABROGATING IL-2 TRANSCRIPTION. OVEREXPRESSION OF EITHER ANTISENSE CREM OR CREB PLASMID RESCUED MORPHINE-INDUCED INHIBITION OF IL-2 PROMOTER ACTIVITY AND PROTEIN PRODUCTION. IN ADDITION, WE ALSO FOUND THAT CHRONIC MORPHINE TREATMENT INHIBITED THE ACETYLATION AND TRIMETHYLATION OF HISTONES AND DECREASED BOTH DNA DEMETHYLATION AND ACCESSIBILITY OF THE IL-2 PROMOTER. THESE FINDINGS SUGGEST THAT CHRONIC MORPHINE TREATMENT MAY FUNCTION THROUGH BOTH TRANSCRIPTIONAL AND EPIGENETIC MECHANISMS TO INHIBIT IL-2 PRODUCTION. 2007 16 3128 28 GIPC-REGULATED IGFBP-3 PROMOTES HSC MIGRATION IN VITRO AND PORTAL HYPERTENSION IN VIVO THROUGH A BETA1-INTEGRIN PATHWAY. BACKGROUND & AIMS: TRANSFORMING GROWTH FACTOR (TGF-BETA)-INDUCED ACTIVATION OF QUIESCENT HEPATIC STELLATE CELLS (HSCS) AND THEIR TRANSFORMATION TO MYOFIBROBLASTS IS A KEY EVENT IN LIVER FIBROSIS AND PORTAL HYPERTENSION. GIPC (ALSO REFERRED TO AS SYNECTIN) IS A DOWNSTREAM SIGNAL ACTIVATION MOLECULE OF TGF-BETA AND OTHER RECEPTORS. IN THIS STUDY, WE SOUGHT TO IDENTIFY NOVEL GENES TARGETED BY TGF-BETA AND GIPC AND ELUCIDATE IF AND HOW THEY MAY CONTRIBUTE TO LIVER FIBROSIS. METHODS: WE PERFORMED SEQUENTIAL MESSENGER RNA SEQUENCING ANALYSIS ON TGF-BETA-STIMULATED HSCS AND THEN ON TGF-BETA-STIMULATED HSCS IN THE PRESENCE AND ABSENCE OF GIPC ALSO REFERRED TO AS SYNECTIN (GIPC) KNOCKDOWN. INSULIN-LIKE GROWTH FACTOR BINDING PROTEIN-3 (IGFBP-3) TRANSPORT PROTEIN EMERGED AS A TOP ACTIVATION TARGET OF BOTH TGF-BETA AND GIPC. QUANTITATIVE POLYMERASE CHAIN REACTION, ENZYME-LINKED IMMUNOSORBENT ASSAY, TARGETED CHROMATIN IMMUNOPRECIPITATION, AND WESTERN BLOT ANALYSIS WERE DONE FOR FURTHER CONFIRMATION. RESULTS: IGFBP-3, AN INSULIN GROWTH FACTOR TRANSPORT PROTEIN, EMERGED AS A TOP ACTIVATION TARGET OF BOTH TGF-BETA AND GIPC, WHICH WAS CONFIRMED BY QUANTITATIVE POLYMERASE CHAIN REACTION, ENZYME-LINKED IMMUNOSORBENT ASSAY, AND WESTERN BLOT ANALYSIS. TARGETED CHROMATIN IMMUNOPRECIPITATION SHOWED THAT GIPC INCREASES THE HISTONE 3 LYSINE 27 (H3K27) ACETYLATION ACTIVATING MARK AND CONCURRENTLY DECREASES THE H3K27 INHIBITORY TRIMETHYLATION (H3K27M3) MARK, PROVIDING AN EPIGENETIC CORRELATE TO THE GENE REGULATION CHANGES. IN VIVO, GLOBAL KNOCKOUT OF IGFBP-3 MICE RESULTED IN ATTENUATION OF HSC ACTIVATION MARKERS AND ATTENUATION OF PORTAL PRESSURE IN RESPONSE TO CHRONIC LIVER INJURY MODELS. ANALYSIS OF SERUM LEVELS FROM CIRRHOTIC PATIENTS ALSO SHOWED AN IGFBP-3 INCREASE OF MORE THAN 2-FOLD COMPARED WITH HEALTHY CONTROLS. FINALLY, IN VITRO MECHANISM STUDIES SHOWED THAT IGFBP-3 PROMOTES HSC MIGRATION THROUGH INTEGRIN-DEPENDENT PHOSPHORYLATION OF PROTEIN KINASE B. CONCLUSIONS: TGF-BETA UP-REGULATES IGFBP-3 THROUGH GIPC, LEADING TO INCREASED HSC MIGRATION IN VITRO AND PROMOTES PORTAL HYPERTENSION IN VIVO. THESE STUDIES SUPPORT THE ROLE OF IGFBP-3 AS A POTENTIAL PATHOPHYSIOLOGIC TARGET OR BIOMARKER IN CHRONIC LIVER DISEASE. 2020 17 4696 22 NF-KAPPAB REPRESSES RETINOIC ACID RECEPTOR-MEDIATED GPRC5A TRANSACTIVATION IN LUNG EPITHELIAL CELLS TO PROMOTE NEOPLASIA. CHRONIC INFLAMMATION IS ASSOCIATED WITH LUNG TUMORIGENESIS, IN WHICH NF-KAPPAB-MEDIATED EPIGENETIC REGULATION PLAYS A CRITICAL ROLE. LUNG TUMOR SUPPRESSOR G PROTEIN-COUPLED RECEPTOR, FAMILY C, MEMBER 5A (GPRC5A), IS REPRESSED IN MOST NON-SMALL CELL LUNG CANCER (NSCLC); HOWEVER, THE MECHANISMS REMAIN UNCLEAR. HERE, WE SHOW THAT NF-KAPPAB ACTS AS A TRANSCRIPTIONAL REPRESSOR IN SUPPRESSION OF GPRC5A. NF-KAPPAB INDUCED GPRC5A REPRESSION BOTH IN VITRO AND IN VIVO. INTRIGUINGLY, TRANSACTIVATION OF NF-KAPPAB DOWNSTREAM TARGETS WAS NOT REQUIRED, BUT THE TRANSACTIVATION DOMAIN OF RELA/P65 WAS REQUIRED FOR GPRC5A REPRESSION. NF-KAPPAB DID NOT BIND TO ANY POTENTIAL CIS-ELEMENT IN THE GPRC5A PROMOTER. INSTEAD, P65 WAS COMPLEXED WITH RETINOIC ACID RECEPTOR ALPHA/BETA (RARALPHA/BETA) AND RECRUITED TO THE RA RESPONSE ELEMENT SITE AT THE GPRC5A PROMOTER, RESULTING IN DISRUPTED RNA POLYMERASE II COMPLEXING AND SUPPRESSED TRANSCRIPTION. NOTABLY, PHOSPHORYLATION ON SERINE 276 OF P65 WAS REQUIRED FOR INTERACTION WITH RARALPHA/BETA AND REPRESSION OF GPRC5A. MOREOVER, NF-KAPPAB-MEDIATED EPIGENETIC REPRESSION WAS THROUGH SUPPRESSION OF ACETYLATED HISTONE H3K9 (H3K9AC), BUT NOT DNA METHYLATION OF THE CPG ISLANDS, AT THE GPRC5A PROMOTER. CONSISTENTLY, A HISTONE DEACETYLASE INHIBITOR, BUT NOT DNA METHYLATION INHIBITOR, RESTORED GPRC5A EXPRESSION IN NSCLC CELLS. THUS, NF-KAPPAB INDUCES TRANSCRIPTIONAL REPRESSION OF GPRC5A VIA A COMPLEX WITH RARALPHA/BETA AND MEDIATES EPIGENETIC REPRESSION VIA SUPPRESSION OF H3K9AC. 2023 18 3153 33 GLUCOSE-INDUCED EXPRESSION OF THE HOMEOTIC TRANSCRIPTION FACTOR PREP1 IS ASSOCIATED WITH HISTONE POST-TRANSLATIONAL MODIFICATIONS IN SKELETAL MUSCLE. AIMS/HYPOTHESIS: CHRONIC HYPERGLYCAEMIA WORSENS INSULIN RESISTANCE IN INDIVIDUALS WITH TYPE 2 DIABETES. WHETHER THIS EFFECT IS CONTRIBUTED BY EPIGENETIC DYSREGULATION AND WHICH GENES ARE INVOLVED REMAIN UNCLEAR. PREP1 (ALSO KNOWN AS PKNOX1) IS A GENE EXERTING MAJOR EFFECTS ON THE SENSITIVITY OF THE GLUCOSE TRANSPORT MACHINERY TO INSULIN. HERE, WE SHOW THAT DYSREGULATION OF PREP1 EXPRESSION BY HIGH GLUCOSE LEVELS IS ASSOCIATED WITH HISTONE MODIFICATIONS AT ITS 5' REGULATORY REGION. METHODS: WE USED MOUSE AND CELL MODELS TO INVESTIGATE PREP1 TRANSCRIPTIONAL REGULATION BY GLUCOSE. RESULTS: DIFFERENTIATED L6 SKELETAL MUSCLE CELLS WERE GROWN IN THE PRESENCE OF EITHER 5.5 OR 25 MMOL/L GLUCOSE (NORMAL [NG] AND HIGH GLUCOSE [HG], RESPECTIVELY). THE HG EXPOSURE INCREASED NUCLEAR FACTOR KAPPA LIGHT CHAIN ENHANCER OF ACTIVATED B CELLS (NF-KAPPAB) P65 BINDING AND RECRUITMENT OF THE SU(VAR)3-9, ENHANCER-OF-ZESTE, TRITHORAX DOMAIN-CONTAINING LYSINE METHYLTRANSFERASE 7 (SET7) HISTONE METHYLTRANSFERASE AND P300 ACETYLTRANSFERASE TO THE 5' REGION OF PREP1, LEADING TO ENHANCED TRANSCRIPTION. IN ADDITION, CHROMATIN IMMUNOPRECIPITATION ASSAYS REVEALED CONCOMITANTLY INCREASED HISTONE H3 MONO- AND DIMETHYLATION AND ACETYLATION AT LYS4 AND LYS9/14, RESPECTIVELY. SKELETAL MUSCLE TISSUE FROM STREPTOZOTOCIN-TREATED DIABETIC MICE ALSO SHOWED PREP1 OVEREXPRESSION ACCOMPANIED BY SIMILARLY INCREASED RECRUITMENT OF NF-KAPPAB P65 AND HISTONE MODIFICATIONS AT THE 5' REGION OF PREP1. IN THESE SAME MICE, AS WELL AS IN PREP1-OVEREXPRESSING L6 CELLS, PREP1-INDUCED RECRUITMENT OF THE REPRESSOR COMPLEX MYOCYTE ENHANCER FACTOR 2 (MEF2)/HISTONE DEACETYLASE 5 (HDAC5) AT THE GLUT4 PROMOTER WAS ALSO INCREASED, LEADING TO REDUCED GLUT4 EXPRESSION. CONCLUSIONS/INTERPRETATION: THESE STUDIES INDICATE THAT HG EXPOSURE INDUCES NF-KAPPAB RECRUITMENT AND HISTONE MODIFICATION AT THE PREP1 5' REGION, THEREBY ENHANCING THE TRANSCRIPTION OF PREP1 AND REPRESSING THAT OF GLUT4. HISTONE CHANGES AT THE PREP1 GENE MAY CONTRIBUTE TO INSULIN RESISTANCE IN INDIVIDUALS WITH TYPE 2 DIABETES. 2016 19 1675 21 DRP1-MEDIATED MITOCHONDRIAL FISSION PROMOTES RENAL FIBROBLAST ACTIVATION AND FIBROGENESIS. EXCESSIVE MITOCHONDRIAL FISSION ACTS AS A PRO-PROLIFERATIVE MARKER IN SOME CANCERS AND ORGAN FIBROSIS; ITS POTENTIAL ROLE IN RENAL FIBROBLAST ACTIVATION AND FIBROGENESIS HAS NEVER BEEN INVESTIGATED. HERE, WE SHOWED MORE PRONOUNCED FRAGMENTED MITOCHONDRIA IN FIBROTIC THAN IN NON-FIBROTIC RENAL FIBROBLAST IN HUMANS AND MICE. IN A MOUSE MODEL OF OBSTRUCTIVE NEPHROPATHY, PHOSPHORYLATION OF DRP1 AT SERINE 616 (P-DRP1S616) AND ACETYLATION OF H3K27(H3K27AC) WAS INCREASED IN FIBROTIC KIDNEYS; PHARMACOLOGICAL INHIBITION OF MITOCHONDRIAL FISSION BY MDIVI-1 SUBSTANTIALLY REDUCED H3K27AC LEVELS, FIBROBLASTS ACCUMULATION, AND INTERSTITIAL FIBROSIS. MOREOVER, MDIVI-1 TREATMENT WAS ABLE TO ATTENUATE THE ESTABLISHED RENAL FIBROSIS. IN CULTURED RENAL INTERSTITIAL FIBROBLASTS, TARGETING DRP1 USING PHARMACOLOGICAL INHIBITOR OR SIRNA SUPPRESSED TGF-BETA1-ELICITED CELL ACTIVATION AND PROLIFERATION, AS EVIDENCED BY INHIBITING EXPRESSION OF ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA) AND COLLAGEN I, AS WELL AS BY REDUCING DNA SYNTHESIS. IN CONTRAST, DRP1 DELETION ENHANCED CELL APOPTOSIS, ALONG WITH DECREASED MITOCHONDRIAL FRAGMENTATION, MTROS ELEVATION, AND GLYCOLYTIC SHIFT UPON TGF-BETA1 STIMULATION. IN DRP1 DELETION FIBROBLASTS, RE-EXPRESSION OF WILD-TYPE DRP1 RATHER THAN DRP1S616A MUTANT RESTORES THE REDUCTION OF TGF-BETA-INDUCED-DRP1 PHOSPHORYLATION, H3K27AC, AND CELL ACTIVATION. MOREOVER, TGF-BETA1 TREATMENT INCREASED THE ENRICHMENT OF H3K27AC AT THE PROMOTERS OF ALPHA-SMA AND PCNA, WHICH WAS REVERSED IN DRP1-KNOCKDOWN FIBROBLASTS CO-TRANSFECTED WITH EMPTY VECTOR OR DRP1S616A, BUT NOT WILD-TYPE DRP1. COLLECTIVELY, OUR RESULTS IMPLY THAT INHIBITING P-DRP1S616-MEDIATED MITOCHONDRIAL FISSION ATTENUATES FIBROBLAST ACTIVATION AND PROLIFERATION IN RENAL FIBROSIS THROUGH EPIGENETIC REGULATION OF FIBROSIS-RELATED GENES TRANSCRIPTION AND MAY SERVE AS A THERAPEUTIC TARGET FOR RETARDING PROGRESSION OF CHRONIC KIDNEY DISEASE. 2020 20 273 29 AGE-INDUCED SUPPRESSION OF EZH2 MEDIATES INJURY OF PODOCYTES BY REDUCING H3K27ME3. BACKGROUND: CHRONIC HYPERGLYCEMIA, A PIVOTAL FEATURE OF DIABETES MELLITUS (DM), INITIATES THE FORMATION OF ADVANCED GLYCATION END PRODUCTS (AGES) AND THE DYSREGULATION OF EPIGENETIC MECHANISMS, WHICH MAY CAUSE INJURY TO RENAL PODOCYTES, A CENTRAL FEATURE OF DIABETIC KIDNEY DISEASE (DKD). PREVIOUS DATA OF OUR GROUP SHOWED THAT AGES SIGNIFICANTLY REDUCE THE EXPRESSION OF NIPP1 (NUCLEAR INHIBITOR OF PROTEIN PHOSPHATASE 1) IN PODOCYTES IN VITRO AS WELL AS IN HUMAN AND MURINE DKD. NIPP1 WAS SHOWN BY OTHERS TO INTERACT WITH ENHANCER OF ZESTE HOMOLOG 2 (EZH2), WHICH CATALYZES THE REPRESSIVE METHYLATION OF H3K27ME3 ON HISTONE 3. THEREFORE, WE HYPOTHESIZED THAT AGES CAN DIRECTLY INDUCE EPIGENETIC CHANGES IN PODOCYTES. METHODS: WE ANALYZED THE RELEVANCE OF AGES ON EZH2 EXPRESSION AND ACTIVITY IN A MURINE PODOCYTE CELL LINE. CELLS WERE TREATED WITH 5 MG/ML GLYCATED BSA FOR 24 H. TO DETERMINE THE MEANING OF EZH2 SUPPRESSION, EZH2 ACTIVITY WAS INHIBITED BY INCUBATING THE CELLS WITH THE PHARMACOLOGICAL METHYLTRANSFERASE INHIBITOR 3-DEAZANEPLANOCIN A; EZH2 EXPRESSION WAS REPRESSED WITH SIRNA. MRNA EXPRESSION WAS ANALYZED WITH REAL-TIME PCR, AND PROTEIN EXPRESSION WITH WESTERN BLOT. EZH2 EXPRESSION AND LEVEL OF H3K27 TRIMETHYLATION IN PODOCYTES OF DIABETIC DB/DB MICE, A MOUSE MODEL FOR TYPE 2 DM, WERE ANALYZED USING IMMUNOFLUORESCENCE. RESULTS: OUR DATA DEMONSTRATED THAT AGES DECREASE EZH2 EXPRESSION IN PODOCYTES AND CONSEQUENTLY REDUCE H3K27ME3. THIS SUPPRESSION OF EZH2 MIMICKED THE AGE EFFECTS AND CAUSED AN UPREGULATED EXPRESSION OF PATHOLOGICAL FACTORS THAT CONTRIBUTE TO PODOCYTE INJURY IN DKD. IN ADDITION, ANALYSES OF DB/DB MICE SHOWED SIGNIFICANTLY REDUCED H3K27ME3 AND EZH2 EXPRESSION IN PODOCYTES. MOREOVER, THE SUPPRESSION OF NIPP1 AND EZH2 SHOWED SIMILAR EFFECTS REGARDING PODOCYTE INJURY. CONCLUSIONS: OUR STUDIES PROVIDE A NOVEL PATHWAY HOW AGES CONTRIBUTE TO PODOCYTE INJURY AND THE FORMATION OF THE SO-CALLED METABOLIC MEMORY IN DKD. 2020