1 3388 93 HOMOCYSTEINE INDUCES PODOCYTE APOPTOSIS BY REGULATING MIR-1929-5P EXPRESSION THROUGH C-MYC, DNMT1 AND EZH2. CHRONIC KIDNEY DISEASE (CKD) IS A COMMON AND COMPLEX DISEASE IN KIDNEYS WHICH HAS BEEN ASSOCIATED WITH AN INCREASED RISK OF RENAL CELL CARCINOMA. ELEVATED HOMOCYSTEINE (HCY) LEVELS ARE KNOWN TO INFLUENCE THE DEVELOPMENT AND PROGRESSION OF CKD BY REGULATING PODOCYTE INJURY AND APOPTOSIS. TO INVESTIGATE THE MOLECULAR MECHANISMS TRIGGERED IN PODOCYTES BY HCY, WE USED CBS(+/-) MICE AND OBSERVED THAT HIGHER HCY LEVELS INCREASED THE APOPTOSIS RATE OF PODOCYTES WITH ACCOMPANYING GLOMERULAR DAMAGE. HCY-INDUCED PODOCYTE INJURY AND APOPTOSIS IN CBS(+/-) MICE WAS REGULATED BY INHIBITION OF MICRORNA (MIR)-1929-5P EXPRESSION. OVEREXPRESSION OF MIR-1929-5P IN PODOCYTES INHIBITED APOPTOSIS BY UPREGULATING BCL-2. FURTHERMORE, THE EXPRESSION OF MIR-1929-5P WAS REGULATED BY EPIGENETIC MODIFICATIONS OF ITS PROMOTER. HCY UPREGULATED DNA METHYLTRANSFERASE 1 (DNMT1) AND ENHANCER OF ZESTE HOMOLOG 2 (EZH2) LEVELS, RESULTING IN INCREASED DNA METHYLATION AND H3K27ME3 LEVELS ON THE MIR-1929-5P PROMOTER. ADDITIONALLY, WE OBSERVED THAT C-MYC RECRUITED DNMT1 AND EZH2 TO THE MIR-1929-5P PROMOTER AND SUPPRESSED THE EXPRESSION OF MIR-1929-5P. IN SUMMARY, WE DEMONSTRATED THAT HCY PROMOTES PODOCYTE APOPTOSIS THROUGH THE REGULATION OF THE EPIGENETIC MODIFIERS DNMT1 AND EZH2, WHICH ARE RECRUITED BY C-MYC TO THE PROMOTER OF MIR-1929-5P TO SILENCE MIR-1929-5P EXPRESSION. 2021 2 273 40 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 3 141 32 ABERRANT DNA METHYLATION OF MTOR PATHWAY GENES PROMOTES INFLAMMATORY ACTIVATION OF IMMUNE CELLS IN DIABETIC KIDNEY DISEASE. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF DIABETIC KIDNEY DISEASE (DKD), BUT THE UNDERLYING MECHANISMS REMAIN UNCLEAR. IN THIS STUDY, WE TESTED THE HYPOTHESIS THAT ABERRANT DNA METHYLATION IN PERIPHERAL IMMUNE CELLS CONTRIBUTES TO DKD PROGRESSION. WE SHOWED THAT LEVELS OF DNA METHYLTRANSFERASE 1 (DNMT1), A KEY ENZYME FOR DNA METHYLATION, WERE INCREASED ALONG WITH INFLAMMATORY ACTIVITY OF PERIPHERAL BLOOD MONONUCLEAR CELLS IN DKD PATIENTS. INHIBITION OF DNMT1 WITH 5-AZA-2'-DEOXYCYTIDINE (5-AZA) MARKEDLY INCREASED THE PROPORTION OF CD4(+)CD25(+) REGULATORY T CELLS IN PERIPHERAL BLOOD MONONUCLEAR CELLS IN CULTURE AND IN DIABETIC ANIMALS. ADOPTIVE TRANSFER OF IMMUNE CELLS FROM 5-AZA-TREATED ANIMALS SHOWED BENEFICIAL EFFECTS ON THE HOST IMMUNE SYSTEM, RESULTING IN A SIGNIFICANT IMPROVEMENT OF DKD. USING GENOME-WIDE DNA METHYLATION ASSAYS, WE IDENTIFIED THE DIFFERENTIALLY METHYLATED CYTOSINES IN THE PROMOTER REGIONS OF MAMMALIAN TARGET OF RAPAMYCIN (MTOR) REGULATORS IN PERIPHERAL BLOOD MONONUCLEAR CELLS OF DIABETIC PATIENTS. FURTHER, MRNA ARRAYS CONFIRMED THE CONSISTENT INDUCTION OF GENES EXPRESSED IN THE MTOR PATHWAY. IMPORTANTLY, DOWN-REGULATION OF DNMT1 EXPRESSION VIA RNA INTERFERENCE RESULTED IN PROMINENT CYTOSINE DEMETHYLATION OF MTOR NEGATIVE REGULATORS AND SUBSEQUENT DECREASE OF MTOR ACTIVITY. LASTLY, MODULATION OF MTOR RESULTED IN CHANGES IN THE EFFECT OF 5-AZA ON DIABETIC IMMUNE CELLS. THUS, UP-REGULATION OF DNMT1 IN DIABETIC IMMUNE CELLS INDUCES ABERRANT CYTOSINE METHYLATION OF THE UPSTREAM REGULATORS OF MTOR, LEADING TO PATHOGENIC ACTIVATION OF THE MTOR PATHWAY AND CONSEQUENT INFLAMMATION IN DIABETIC KIDNEYS. HENCE, THIS STUDY HIGHLIGHTS THERAPEUTIC POTENTIAL OF TARGETING EPIGENETIC EVENTS IN IMMUNE SYSTEM FOR TREATING DKD. 2019 4 3367 32 HISTONE METHYLTRANSFERASE EZH2: A POTENTIAL THERAPEUTIC TARGET FOR KIDNEY DISEASES. ENHANCER OF ZESTE HOMOLOG 2 (EZH2) IS A HISTONE-LYSINE N-METHYLTRANSFERASE ENZYME THAT CATALYZES THE ADDITION OF METHYL GROUPS TO HISTONE H3 AT LYSINE 27, LEADING TO GENE SILENCING. MUTATION OR OVER-EXPRESSION OF EZH2 HAS BEEN LINKED TO MANY CANCERS INCLUDING RENAL CARCINOMA. RECENT STUDIES HAVE SHOWN THAT EZH2 EXPRESSION AND ACTIVITY ARE ALSO INCREASED IN SEVERAL ANIMAL MODELS OF KIDNEY INJURY, SUCH AS ACUTE KIDNEY INJURY (AKI), RENAL FIBROSIS, DIABETIC NEPHROPATHY, LUPUS NEPHRITIS (LN), AND RENAL TRANSPLANTATION REJECTION. THE PHARMACOLOGICAL AND/OR GENETIC INHIBITION OF EZH2 CAN ALLEVIATE AKI, RENAL FIBROSIS, AND LN, BUT POTENTIATE PODOCYTE INJURY IN ANIMAL MODELS, SUGGESTING THAT THE FUNCTIONAL ROLE OF EZH2 VARIES WITH RENAL CELL TYPE AND DISEASE MODEL. IN THIS ARTICLE, WE SUMMARIZE THE ROLE OF EZH2 IN THE PATHOLOGY OF RENAL INJURY AND RELEVANT MECHANISMS AND HIGHLIGHT EZH2 AS A POTENTIAL THERAPEUTIC TARGET FOR KIDNEY DISEASES. 2021 5 5972 21 TET REPRESSION AND INCREASED DNMT ACTIVITY SYNERGISTICALLY INDUCE ABERRANT DNA METHYLATION. CHRONIC INFLAMMATION IS DEEPLY INVOLVED IN VARIOUS HUMAN DISORDERS, SUCH AS CANCER, NEURODEGENERATIVE DISORDERS, AND METABOLIC DISORDERS. INDUCTION OF EPIGENETIC ALTERATIONS, ESPECIALLY ABERRANT DNA METHYLATION, IS ONE OF THE MAJOR MECHANISMS, BUT HOW IT IS INDUCED IS STILL UNCLEAR. HERE, WE FOUND THAT EXPRESSION OF TET GENES, METHYLATION ERASERS, WAS DOWNREGULATED IN INFLAMED MOUSE AND HUMAN TISSUES, AND THAT THIS WAS CAUSED BY UPREGULATION OF TET-TARGETING MIRNAS SUCH AS MIR20A, MIR26B, AND MIR29C, LIKELY DUE TO ACTIVATION OF NF-KAPPAB SIGNALING DOWNSTREAM OF IL-1BETA AND TNF-ALPHA. HOWEVER, TET KNOCKDOWN INDUCED ONLY MILD ABERRANT METHYLATION. NITRIC OXIDE (NO), PRODUCED BY NOS2, ENHANCED ENZYMATIC ACTIVITY OF DNA METHYLTRANSFERASES (DNMTS), METHYLATION WRITERS, AND NO EXPOSURE INDUCED MINIMAL ABERRANT METHYLATION. IN CONTRAST, A COMBINATION OF TET KNOCKDOWN AND NO EXPOSURE SYNERGISTICALLY INDUCED ABERRANT METHYLATION, INVOLVING GENOMIC REGIONS NOT METHYLATED BY EITHER ALONE. THE RESULTS SHOWED THAT A VICIOUS COMBINATION OF TET REPRESSION, DUE TO NF-KAPPAB ACTIVATION, AND DNMT ACTIVATION, DUE TO NO PRODUCTION, IS RESPONSIBLE FOR ABERRANT METHYLATION INDUCTION IN HUMAN TISSUES. 2020 6 6321 25 THE ROLE AND MECHANISM OF LYSINE METHYLTRANSFERASE AND ARGININE METHYLTRANSFERASE IN KIDNEY DISEASES. METHYLATION CAN OCCUR IN BOTH HISTONES AND NON-HISTONES. KEY LYSINE AND ARGININE METHYLTRANSFERASES UNDER INVESTIGATION FOR RENAL DISEASE TREATMENT INCLUDE ENHANCER OF ZESTE HOMOLOG 2 (EZH2), G9A, DISRUPTOR OF TELOMERIC SILENCING 1-LIKE PROTEIN (DOT1L), AND PROTEIN ARGININE METHYLTRANSFERASES (PRMT) 1 AND 5. RECENT STUDIES HAVE SHOWN THAT METHYLTRANSFERASES EXPRESSION AND ACTIVITY ARE ALSO INCREASED IN SEVERAL ANIMAL MODELS OF KIDNEY INJURY, SUCH AS ACUTE KIDNEY INJURY(AKI), OBSTRUCTIVE NEPHROPATHY, DIABETIC NEPHROPATHY AND LUPUS NEPHRITIS. THE INHIBITION OF MOST METHYLTRANSFERASES CAN ATTENUATE KIDNEY INJURY, WHILE THE ROLE OF METHYLTRANSFERASE IN DIFFERENT ANIMAL MODELS REMAINS CONTROVERSIAL. IN THIS ARTICLE, WE SUMMARIZE THE ROLE AND MECHANISM OF LYSINE METHYLTRANSFERASE AND ARGININE METHYLTRANSFERASE IN VARIOUS KIDNEY DISEASES AND HIGHLIGHT METHYLTRANSFERASE AS A POTENTIAL THERAPEUTIC TARGET FOR KIDNEY DISEASES. 2022 7 1494 40 DNA HYPERMETHYLATION IN HYPERHOMOCYSTEINEMIA CONTRIBUTES TO ABNORMAL EXTRACELLULAR MATRIX METABOLISM IN THE KIDNEY. HYPERHOMOCYSTEINEMIA (HHCY) IS PREVALENT IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD) AND END-STAGE RENAL DISEASE (ESRD). EMERGING STUDIES SUGGEST THAT EPIGENETIC MECHANISMS CONTRIBUTE TO THE DEVELOPMENT AND PROGRESSION OF FIBROSIS IN CKD. HHCY AND ITS INTERMEDIATES ARE KNOWN TO ALTER THE DNA METHYLATION PATTERN, WHICH IS A CRITICAL REGULATOR OF EPIGENETIC INFORMATION. IN THIS STUDY, WE HYPOTHESIZED THAT HHCY CAUSES RENOVASCULAR REMODELING BY DNA HYPERMETHYLATION, LEADING TO GLOMERULOSCLEROSIS. WE ALSO EVALUATED WHETHER THE DNA METHYLATION INHIBITOR, 5-AZA-2'-DEOXYCYTIDINE (5-AZA) COULD MODULATE EXTRACELLULAR MATRIX (ECM) METABOLISM AND REDUCE RENOVASCULAR FIBROSIS. C57BL/6J (WILD-TYPE) AND CYSTATHIONINE-BETA-SYNTHASE (CBS(+/-)) MICE, TREATED WITHOUT OR WITH 5-AZA (0.5 MG/KG BODY WEIGHT, I.P.), WERE USED. CBS(+/-) MICE SHOWED HIGH PLASMA HCY LEVELS, HYPERTENSION, AND SIGNIFICANT GLOMERULAR AND ARTERIOLAR INJURY. 5-AZA TREATMENT NORMALIZED BLOOD PRESSURE AND REVERSED RENAL INJURY. CBS(+/-) MICE SHOWED GLOBAL HYPERMETHYLATION AND UP-REGULATION OF DNA METHYLTRANSFERASE-1 AND -3A. METHYLATION-SPECIFIC PCR SHOWED AN IMBALANCE BETWEEN MATRIX METALLOPROTEINASE (MMP)-9 AND TISSUE INHIBITOR OF METALLOPROTEINASE (TIMP)-1 AND -2 AND ALSO INCREASED COLLAGEN AND GALECTIN-3 EXPRESSION. 5-AZA REDUCED ABNORMAL DNA METHYLATION AND RESTORED THE MMP-9/TIMP-1, -2 BALANCE. IN CONCLUSION, OUR DATA SUGGEST THAT DURING HHCY, ABNORMAL DNA METHYLATION AND AN IMBALANCE BETWEEN MMP-9 AND TIMP-1 AND -2 LEAD TO ECM REMODELING AND RENAL FIBROSIS. 2015 8 3527 30 IL-6 ENHANCES THE NUCLEAR TRANSLOCATION OF DNA CYTOSINE-5-METHYLTRANSFERASE 1 (DNMT1) VIA PHOSPHORYLATION OF THE NUCLEAR LOCALIZATION SEQUENCE BY THE AKT KINASE. THE EPIGENETIC PROGRAMMING OF GENOMIC DNA IS ACCOMPLISHED, IN PART, BY SEVERAL DNA CYTOSINE-5-METHYLTRANSFERASES THAT ACT BY COVALENTLY MODIFYING CYTOSINES WITH THE ADDITION OF A METHYL GROUP. THIS COVALENT MODIFICATION IS MAINTAINED BY THE DNA CYTOSINE-5-METHYLTRANSFERASE-1 ENZYME (DNMT1), WHICH IS CAPABLE OF ACTING IN CONCERT WITH OTHER SIMILAR ENZYMES TO SILENCE IMPORTANT TUMOR SUPPRESSOR GENES. IL-6 IS A MULTIFUNCTIONAL MEDIATOR OF INFLAMMATION, ACTING THROUGH SEVERAL MAJOR SIGNALING CASCADES, INCLUDING THE PHOSPHATIDYLINOSITOL-3-KINASE PATHWAY (PI-3-K), WHICH ACTIVATES PROTEIN KINASE B (AKT/PKB) DOWNSTREAM. HERE, WE SHOW THAT THE SUBCELLULAR LOCALIZATION OF DNMT1 CAN BE ALTERED BY THE ADDITION OF IL-6, INCREASING THE RATE OF NUCLEAR TRANSLOCATION OF THE ENZYME FROM THE CYTOSOLIC COMPARTMENT. THE MECHANISM OF NUCLEAR TRANSLOCATION OF DNMT1 IS GREATLY ENHANCED BY PHOSPHORYLATION OF THE DNMT1 NUCLEAR LOCALIZATION SIGNAL (NLS) BY PKB/AKT KINASE. MUTAGENIC ALTERATION OF THE TWO AKT TARGET AMINO ACIDS WITHIN THE NLS RESULTS IN A MAJOR LOSS OF DNMT1 NUCLEAR TRANSLOCATION, WHILE THE CREATION OF A "PHOSPHO-MIMIC" AMINO ACID (MUTATION TO ACIDIC RESIDUES) RESTORES THIS COMPARTMENTATION ABILITY. THESE OBSERVATIONS SUGGEST AN INTERESTING HYPOTHESIS REGARDING HOW MEDIATORS OF CHRONIC INFLAMMATION MAY DISTURB THE DELICATE BALANCE OF CELLULAR COMPARTMENTALIZATION OF IMPORTANT PROTEINS, AND REVEALS A POTENTIAL MECHANISM FOR THE INDUCTION OR ENHANCEMENT OF TUMOR GROWTH VIA ALTERATION OF THE COMPONENTS INVOLVED IN THE EPIGENETIC PROGRAMMING OF A CELL. 2007 9 1615 30 DNA METHYLTRANSFERASE 3B PLAYS A PROTECTIVE ROLE AGAINST HEPATOCARCINOGENESIS CAUSED BY CHRONIC INFLAMMATION VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. MOST HEPATOCELLULAR CARCINOMAS (HCCS) DEVELOP ON THE BASIS OF CHRONIC HEPATITIS, BUT THE MECHANISM OF EPIGENETIC REGULATION IN INFLAMMATORY HEPATOCARCINOGENESIS HAS YET TO BE ELUCIDATED. AMONG DE NOVO DNA METHYLTRANSFERASES (DNMTS), DNMT3B HAS LATELY BEEN REPORTED TO ACT SPECIFICALLY ON ACTIVELY TRANSCRIBED GENES, SUGGESTING THE POSSIBILITY THAT IT PLAYS A ROLE IN THE PATHOGENESIS OF CANCER. WE CONFIRMED THAT DNMT3B ISOFORMS LACKING ITS CATALYTIC DOMAIN WERE HIGHLY EXPRESSED IN HCCS COMPARED WITH NON-TUMOROUS LIVER TISSUE. TO ELUCIDATE THE ROLE OF DNMT3B IN HEPATOCARCINOGENESIS, WE GENERATED A GENETICALLY ENGINEERED MOUSE MODEL WITH HEPATOCYTE-SPECIFIC DNMT3B DELETION. THE LIVER OF THE DNMT3B-DEFICIENT MICE EXHIBITED AN EXACERBATION OF THIOACETAMIDE-INDUCED HEPATITIS, PROGRESSION OF LIVER FIBROSIS AND A HIGHER INCIDENCE OF HCC COMPARED WITH THE LIVER OF THE CONTROL MICE. WHOLE-GENOME BISULFITE SEQUENCING VERIFIED A LOWER CG METHYLATION LEVEL IN THE DNMT3B-DEFICIENT LIVER, DEMONSTRATING DIFFERENTIALLY METHYLATED REGIONS THROUGHOUT THE GENOME. TRANSCRIPTOME ANALYSIS REVEALED DECREASED EXPRESSION OF GENES RELATED TO OXIDATIVE PHOSPHORYLATION IN THE DNMT3B-DEFICIENT LIVER. MOREOVER, PRIMARY HEPATOCYTES ISOLATED FROM THE DNMT3B-DEFICIENT MICE SHOWED REDUCED MITOCHONDRIAL RESPIRATORY CAPACITY, LEADING TO THE ENHANCEMENT OF OXIDATIVE STRESS IN THE LIVER TISSUE. OUR FINDINGS SUGGEST THE PROTECTIVE ROLE OF DNMT3B AGAINST CHRONIC INFLAMMATION AND HCC DEVELOPMENT VIA MAINTAINING MITOCHONDRIAL HOMEOSTASIS. 2020 10 4900 37 OXIDATIVE STRESS-INDUCED EPIGENETIC CHANGES ASSOCIATED WITH MALIGNANT TRANSFORMATION OF HUMAN KIDNEY EPITHELIAL CELLS. RENAL CELL CARCINOMA (RCC) IN HUMANS IS POSITIVELY INFLUENCED BY OXIDATIVE STRESS STATUS IN KIDNEYS. WE RECENTLY REPORTED THAT ADAPTIVE RESPONSE TO LOW LEVEL OF CHRONIC OXIDATIVE STRESS INDUCES MALIGNANT TRANSFORMATION OF IMMORTALIZED HUMAN RENAL TUBULAR EPITHELIAL CELLS. EPIGENETIC ALTERATIONS IN HUMAN RCC ARE WELL DOCUMENTED, BUT ITS ROLE IN OXIDATIVE STRESS-INDUCED MALIGNANT TRANSFORMATION OF KIDNEY CELLS IS NOT KNOWN. THEREFORE, THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE THE POTENTIAL ROLE OF EPIGENETIC CHANGES IN CHRONIC OXIDATIVE STRESS-INDUCED MALIGNANT TRANSFORMATION OF HK-2, HUMAN RENAL TUBULAR EPITHELIAL CELLS. THE RESULTS REVEALED ABERRANT EXPRESSION OF EPIGENETIC REGULATORY GENES INVOLVED IN DNA METHYLATION (DNMT1, DNMT3A AND MBD4) AND HISTONE MODIFICATIONS (HDAC1, HMT1 AND HAT1) IN HK-2 CELLS MALIGNANTLY TRANSFORMED BY CHRONIC OXIDATIVE STRESS. ADDITIONALLY, BOTH IN VITRO SOFT AGAR ASSAY AND IN VIVO NUDE MICE STUDY SHOWING DECREASED TUMORIGENIC POTENTIAL OF MALIGNANTLY TRANSFORMED HK-2 CELLS FOLLOWING TREATMENT WITH DNA DE-METHYLATING AGENT 5-AZA 2' DC FURTHER CONFIRMED THE CRUCIAL ROLE OF DNA HYPERMETHYALTION IN OXIDATIVE STRESS-INDUCED MALIGNANT TRANSFORMATION. CHANGES OBSERVED IN GLOBAL HISTONE H3 ACETYLATION (H3K9, H3K18, H3K27 AND H3K14) AND DECREASE IN PHOSPHO-H2AX (SER139) ALSO SUGGEST POTENTIAL ROLE OF HISTONE MODIFICATIONS IN INCREASED SURVIVAL AND MALIGNANT TRANSFORMATION OF HK-2 CELLS BY OXIDATIVE STRESS. IN SUMMARY, THE RESULTS OF THIS STUDY SUGGEST THAT EPIGENETIC REPROGRAMMING INDUCED BY LOW LEVELS OF OXIDATIVE STRESS ACT AS DRIVER FOR MALIGNANT TRANSFORMATION OF KIDNEY EPITHELIAL CELLS. FINDINGS OF THIS STUDY ARE HIGHLY RELEVANT IN POTENTIAL CLINICAL APPLICATION OF EPIGENETIC-BASED THERAPEUTICS FOR TREATMENTS OF KIDNEY CANCERS. 2017 11 5675 29 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 4159 34 MECP2 CONTROLS AN EPIGENETIC PATHWAY THAT PROMOTES MYOFIBROBLAST TRANSDIFFERENTIATION AND FIBROSIS. BACKGROUND & AIMS: MYOFIBROBLAST TRANSDIFFERENTIATION GENERATES HEPATIC MYOFIBROBLASTS, WHICH PROMOTE LIVER FIBROGENESIS. THE PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPARGAMMA) IS A NEGATIVE REGULATOR OF THIS PROCESS. WE INVESTIGATED EPIGENETIC REGULATION OF PPARGAMMA AND MYOFIBROBLAST TRANSDIFFERENTIATION. METHODS: CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAYS ASSESSED THE BINDING OF METHYL-CPG BINDING PROTEIN 2 (MECP2) TO PPARGAMMA AND CHROMATIN MODIFICATIONS THAT SILENCE THIS GENE. MECP2(-/Y) MICE AND AN INHIBITOR (DZNEP) OF THE EPIGENETIC REGULATORY PROTEIN EZH2 WERE USED IN THE CARBON TETRACHLORIDE MODEL OF LIVER FIBROSIS. LIVER TISSUES FROM MICE WERE ASSESSED BY HISTOLOGIC ANALYSIS; MARKERS OF FIBROSIS WERE MEASURED BY QUANTITATIVE POLYMERASE CHAIN REACTION (QPCR). REVERSE TRANSCRIPTION PCR DETECTED CHANGES IN EXPRESSION OF THE MICRORNA MIR132 AND ITS TARGET, ELONGATED TRANSCRIPTS OF MECP2. MYOFIBROBLASTS WERE TRANSFECTED WITH MIR132; PPARGAMMA AND MECP2 EXPRESSIONS WERE ANALYZED BY QPCR OR IMMUNOBLOTTING. RESULTS: MYOFIBROBLAST TRANSDIFFERENTIATION OF HEPATIC STELLATE CELLS IS CONTROLLED BY A COMBINATION OF MECP2, EZH2, AND MIR132 IN A RELAY PATHWAY. THE PATHWAY IS ACTIVATED BY DOWN-REGULATION OF MIR132, RELEASING THE TRANSLATIONAL BLOCK ON MECP2. MECP2 IS RECRUITED TO THE 5' END OF PPARGAMMA, WHERE IT PROMOTES METHYLATION BY H3K9 AND RECRUITS THE TRANSCRIPTION REPRESSOR HP1ALPHA. MECP2 ALSO STIMULATES EXPRESSION OF EZH2 AND METHYLATION OF H3K27 TO FORM A REPRESSIVE CHROMATIN STRUCTURE IN THE 3' EXONS OF PPARGAMMA. GENETIC AND PHARMACOLOGIC DISRUPTIONS OF MECP2 OR EZH2 REDUCED THE FIBROGENIC CHARACTERISTICS OF MYOFIBROBLASTS AND ATTENUATED FIBROGENESIS. CONCLUSIONS: LIVER FIBROSIS IS REGULATED BY AN EPIGENETIC RELAY PATHWAY THAT INCLUDES MECP2, EZH2, AND MIR132. REAGENTS THAT INTERFERE WITH THIS PATHWAY MIGHT BE DEVELOPED TO REDUCE FIBROGENESIS IN CHRONIC LIVER DISEASE. 2010 13 6431 33 THE USE OF TARGETED NEXT GENERATION SEQUENCING TO EXPLORE CANDIDATE REGULATORS OF TGF-BETA1'S IMPACT ON KIDNEY CELLS. AIMS/HYPOTHESIS: TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA1) PLAYS AN IMPORTANT REGULATORY ROLE IN THE PROGRESSION OF CHRONIC KIDNEY FAILURE. FURTHER, DAMAGE TO KIDNEY GLOMERULAR MESANGIAL CELLS IS CENTRAL TO THE PROGRESSION OF DIABETIC NEPHROPATHY. THE AIM OF THIS STUDY WAS TO EXPLORE THE GENETIC ASSOCIATIONS BETWEEN MRNA, MICRORNA, AND EPIGENETICS IN MESANGIAL CELLS IN RESPONSE TO TGF-BETA1. METHODS: THE REGULATORY EFFECTS OF TGF-BETA1 ON MESANGIAL CELLS WERE INVESTIGATED AT DIFFERENT MOLECULAR LEVELS BY TREATING MESANGIAL CELLS WITH TGF-BETA1 FOR 3 DAYS FOLLOWED BY GENOME-WIDE MIRNA, RNA, DNA METHYLATION, AND H3K27ME3 EXPRESSION PROFILING USING NEXT GENERATION SEQUENCING (NGS). RESULTS: OUR RESULTS PROVIDE THE FIRST COMPREHENSIVE, COMPUTATIONALLY INTEGRATED REPORT OF RNA-SEQ, MIRNA-SEQ, AND EPIGENOMIC ANALYSES ACROSS ALL GENETIC VARIATIONS, CONFIRMING THE OCCURRENCE OF DNA METHYLATION AND H3K27ME3 IN RESPONSE TO TGF-BETA1. OUR FINDINGS SHOW THAT THE EXPRESSION OF KLF7 AND GJA4 ARE INVOLVED IN TGF-BETA1 REGULATED DNA METHYLATION. OUR DATA ALSO PROVIDE EVIDENCE OF THE ASSOCIATION BETWEEN EPIGENETIC CHANGES AND THE EXPRESSION OF GENES CLOSELY RELATED TO TGF-BETA1 REGULATION. CONCLUSION: THIS STUDY HAS ADVANCED OUR CURRENT KNOWLEDGE OF MECHANISMS THAT CONTRIBUTE TO THE EXPRESSION OF TGF-BETA1-REGULATED GENES INVOLVED IN THE PATHOGENESIS OF KIDNEY DISEASE. THE MOLECULAR UNDERPINNINGS OF TGF-BETA1 STIMULATION OF KIDNEY CELLS WAS DETERMINED, THEREBY PROVIDING A ROBUST PLATFORM FOR FURTHER TARGET EXPLORATION. 2018 14 2825 36 FLOW-DEPENDENT EPIGENETIC REGULATION OF IGFBP5 EXPRESSION BY H3K27ME3 CONTRIBUTES TO ENDOTHELIAL ANTI-INFLAMMATORY EFFECTS. RATIONALE: ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY AND EPIGENETIC DISEASE THAT IS INFLUENCED BY DIFFERENT PATTERNS OF BLOOD FLOW. HOWEVER, THE EPIGENETIC MECHANISM WHEREBY ATHEROPROTECTIVE FLOW CONTROLS ENDOTHELIAL GENE PROGRAMMING REMAINS ELUSIVE. HERE, WE INVESTIGATED THE POSSIBILITY THAT FLOW ALTERS ENDOTHELIAL GENE EXPRESSION THROUGH EPIGENETIC MECHANISMS. METHODS: EN FACE STAINING AND WESTERN BLOT WERE USED TO DETECT PROTEIN EXPRESSION. REAL-TIME PCR WAS USED TO DETERMINE RELATIVE GENE EXPRESSION. RNA-SEQUENCING OF HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS TREATED WITH SIRNA OF ENHANCER OF ZESTE HOMOLOG 2 (EZH2) OR LAMINAR FLOW WAS USED FOR TRANSCRIPTIONAL PROFILING. RESULTS: WE FOUND THAT TRIMETHYLATION OF HISTONE 3 LYSINE 27 (H3K27ME3), A REPRESSIVE EPIGENETIC MARK THAT ORCHESTRATES GENE REPRESSION, WAS REDUCED IN LAMINAR FLOW AREAS OF MOUSE AORTA AND FLOW-TREATED HUMAN ENDOTHELIAL CELLS. THE DECREASE OF H3K27ME3 PARALLELED A REDUCTION IN THE EPIGENETIC "WRITER"-EZH2, THE CATALYTIC SUBUNIT OF THE POLYCOMB REPRESSIVE COMPLEX 2 (PRC2). MOREOVER, LAMINAR FLOW DECREASED EXPRESSION OF EZH2 VIA MECHANOSENSITIVE MIR101. GENOME-WIDE TRANSCRIPTOME PROFILING STUDIES IN ENDOTHELIAL CELLS TREATED WITH EZH2 SIRNA AND FLOW REVEALED THE UPREGULATION OF NOVEL MECHANOSENSITIVE GENE IGFBP5 (INSULIN-LIKE GROWTH FACTOR-BINDING PROTEIN 5), WHICH IS EPIGENETICALLY SILENCED BY H3K27ME3. FUNCTIONALLY, INHIBITION OF H3K27ME3 BY EZH2 SIRNA OR GSK126 (A SPECIFIC EZH2 INHIBITOR) REDUCED H3K27ME3 LEVELS AND MONOCYTE ADHESION TO ENDOTHELIAL CELLS. ADENOVIRAL OVEREXPRESSION OF IGFBP5 ALSO RECAPITULATED THE ANTI-INFLAMMATORY EFFECTS OF H3K27ME3 INHIBITION. MORE IMPORTANTLY, WE OBSERVED EZH2 UPREGULATION, AND IGFBP5 DOWNREGULATION, IN ADVANCED ATHEROSCLEROTIC PLAQUES FROM HUMAN PATIENTS. CONCLUSION: TAKEN TOGETHER, OUR FINDINGS REVEAL THAT ATHEROPROTECTIVE FLOW REDUCES H3K27ME3 AS A CHROMATIN-BASED MECHANISM TO AUGMENT THE EXPRESSION OF GENES THAT CONFER AN ANTI-INFLAMMATORY RESPONSE IN THE ENDOTHELIUM. OUR STUDY EXEMPLIFIES FLOW-DEPENDENT EPIGENETIC REGULATION OF ENDOTHELIAL GENE EXPRESSION, AND ALSO SUGGESTS THAT TARGETING THE EZH2/H3K27ME3/IGFBP5 PATHWAY MAY OFFER NOVEL THERAPEUTICS FOR INFLAMMATORY DISORDERS SUCH AS ATHEROSCLEROSIS. 2018 15 3658 29 INDUCTION OF ABERRANT TRIMETHYLATION OF HISTONE H3 LYSINE 27 BY INFLAMMATION IN MOUSE COLONIC EPITHELIAL CELLS. A FIELD FOR CANCERIZATION (FIELD DEFECT), WHERE GENETIC AND EPIGENETIC ALTERATIONS ARE ACCUMULATED IN NORMAL-APPEARING TISSUES, IS INVOLVED IN HUMAN CARCINOGENESIS, ESPECIALLY CANCERS ASSOCIATED WITH CHRONIC INFLAMMATION. ALTHOUGH ABERRANT DNA METHYLATION IS INVOLVED IN THE FIELD DEFECT AND INDUCED BY CHRONIC INFLAMMATION, IT IS STILL UNCLEAR FOR TRIMETHYLATION OF HISTONE H3 LYSINE 27 (H3K27ME3), WHICH IS INVOLVED IN GENE REPRESSION INDEPENDENT OF DNA METHYLATION AND FUNCTIONS AS A PRE-MARK FOR ABERRANT DNA METHYLATION. IN THIS STUDY, USING A MOUSE COLITIS MODEL INDUCED BY DEXTRAN SULFATE SODIUM (DSS), WE AIMED TO CLARIFY WHETHER ABERRANT H3K27ME3 IS INDUCED BY INFLAMMATION AND INVOLVED IN A FIELD DEFECT. CHIP-ON-CHIP ANALYSIS OF COLONIC EPITHELIAL CELLS REVEALED THAT H3K27ME3 LEVELS WERE INCREASED OR DECREASED FOR 266 GENOMIC REGIONS BY AGING, AND MORE EXTENSIVELY (23 INCREASED AND 3574 DECREASED REGIONS) BY COLITIS. SUCH INCREASE OR DECREASE OF H3K27ME3 WAS INDUCED AS EARLY AS 2 WEEKS AFTER THE INITIATION OF DSS TREATMENT, AND PERSISTED AT LEAST FOR 16 WEEKS EVEN AFTER THE INFLAMMATION DISAPPEARED. SOME OF THE ABERRANT H3K27ME3 IN COLONIC EPITHELIAL CELLS WAS CARRIED OVER INTO COLON TUMORS. FURTHERMORE, H3K27ME3 ACQUIRED AT DAPK1 BY COLITIS WAS FOLLOWED BY INCREASED DNA METHYLATION, SUPPORTING ITS FUNCTION AS A PRE-MARK FOR ABERRANT DNA METHYLATION. THESE RESULTS DEMONSTRATED THAT ABERRANT H3K27ME3 CAN BE INDUCED BY EXPOSURE TO A SPECIFIC ENVIRONMENT, SUCH AS COLITIS, AND SUGGESTED THAT ABERRANT HISTONE MODIFICATION, IN ADDITION TO ABERRANT DNA METHYLATION, IS INVOLVED IN THE FORMATION OF A FIELD DEFECT. 2012 16 3795 33 INTERLEUKIN-6 CONTRIBUTES TO GROWTH IN CHOLANGIOCARCINOMA CELLS BY ABERRANT PROMOTER METHYLATION AND GENE EXPRESSION. THE ASSOCIATION BETWEEN CHRONIC INFLAMMATION AND THE DEVELOPMENT AND PROGRESSION OF MALIGNANCY IS EXEMPLIFIED IN THE BILIARY TRACT WHERE PERSISTENT INFLAMMATION STRONGLY PREDISPOSES TO CHOLANGIOCARCINOMA. THE INFLAMMATORY CYTOKINE INTERLEUKIN-6 (IL-6) ENHANCES TUMOR GROWTH IN CHOLANGIOCARCINOMA BY ALTERED GENE EXPRESSION VIA AUTOCRINE MECHANISMS. IL-6 CAN REGULATE THE ACTIVITY OF DNA METHYLTRANSFERASES, AND MOREOVER, ABERRANT DNA METHYLATION CAN CONTRIBUTE TO CARCINOGENESIS. WE THEREFORE INVESTIGATED THE EFFECT OF CHRONIC EXPOSURE TO IL-6 ON METHYLATION-DEPENDENT GENE EXPRESSION AND TRANSFORMED CELL GROWTH IN HUMAN CHOLANGIOCARCINOMA. THE RELATIONSHIP BETWEEN AUTOCRINE IL-6 PATHWAYS, DNA METHYLATION, AND TRANSFORMED CELL GROWTH WAS ASSESSED USING MALIGNANT CHOLANGIOCYTES STABLY TRANSFECTED TO OVEREXPRESS IL-6. TREATMENT WITH THE DNA METHYLATION INHIBITOR 5-AZA-2'-DEOXYCYTIDINE DECREASED CELL PROLIFERATION, GROWTH IN SOFT AGAR, AND METHYLCYTOSINE CONTENT OF MALIGNANT CHOLANGIOCYTES. HOWEVER, THIS EFFECT WAS NOT OBSERVED IN IL-6-OVEREXPRESSING CELLS. IL-6 OVEREXPRESSION RESULTED IN THE ALTERED EXPRESSION AND PROMOTER METHYLATION OF SEVERAL GENES, INCLUDING THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR). EGFR PROMOTER METHYLATION WAS DECREASED AND GENE AND PROTEIN EXPRESSION WAS INCREASED BY IL-6. THUS, EPIGENETIC REGULATION OF GENE EXPRESSION BY IL-6 CAN CONTRIBUTE TO TUMOR PROGRESSION BY ALTERING PROMOTER METHYLATION AND GENE EXPRESSION OF GROWTH-REGULATORY PATHWAYS, SUCH AS THOSE INVOLVING EGFR. MOREOVER, ENHANCED IL-6 EXPRESSION MAY DECREASE THE SENSITIVITY OF TUMOR CELLS TO THERAPEUTIC TREATMENTS USING METHYLATION INHIBITORS. THESE OBSERVATIONS HAVE IMPORTANT IMPLICATIONS FOR CANCER TREATMENT AND PROVIDE A MECHANISM BY WHICH PERSISTENT CYTOKINE STIMULATION CAN PROMOTE TUMOR GROWTH. 2006 17 2780 31 EZH2 DOWN-REGULATION EXACERBATES LIPID ACCUMULATION AND INFLAMMATION IN IN VITRO AND IN VIVO NAFLD. NON-ALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS ONE OF THE MOST PREVALENT, CHRONIC LIVER DISEASES, WORLDWIDE. IT IS A MULTIFACTORIAL DISEASE CAUSED BY COMPLEX INTERACTIONS BETWEEN GENETIC, EPIGENETIC AND ENVIRONMENTAL FACTORS. RECENTLY, SEVERAL MICRORNAS, SOME OF WHICH EPIGENETICALLY REGULATED, HAVE BEEN FOUND TO BE UP- AND/OR DOWN-REGULATED DURING NAFLD DEVELOPMENT. HOWEVER, IN NAFLD, THE ESSENTIAL ROLE OF THE POLYCOMB GROUP PROTEIN ENHANCER OF ZESTE HOMOLOG 2 (EZH2), WHICH CONTROLS THE EPIGENETIC SILENCING OF SPECIFIC GENES AND/OR MICRORNAS BY TRIMETHYLATING LYS27 ON HISTONE H3, STILL REMAINS UNKNOWN. IN THIS STUDY, WE DEMONSTRATE THAT THE NUCLEAR EXPRESSION/ACTIVITY OF THE EZH2 PROTEIN IS DOWN-REGULATED BOTH IN LIVERS FROM NAFLD RATS AND IN THE FREE FATTY ACID-TREATED HEPG2. THE DROP IN EZH2 IS INVERSELY CORRELATED WITH: (I) LIPID ACCUMULATION; (II) THE EXPRESSION OF PRO-INFLAMMATORY MARKERS INCLUDING TNF-ALPHA AND TGF-BETA; AND (III) THE EXPRESSION OF MIR-200B AND MIR-155. CONSISTENTLY, THE PHARMACOLOGICAL INHIBITION OF EZH2 BY 3-DEAZANEPLANOCIN A (DZNEP) SIGNIFICANTLY REDUCES EZH2 EXPRESSION/ACTIVITY, WHILE IT INCREASES LIPID ACCUMULATION, INFLAMMATORY MOLECULES AND MICRORNAS. IN CONCLUSION, THE RESULTS OF THIS STUDY SUGGEST THAT THE DEFECTIVE ACTIVITY OF EZH2 CAN ENHANCE THE NAFLD DEVELOPMENT BY FAVOURING STEATOSIS AND THE DE-REPRESSION OF THE INFLAMMATORY GENES AND THAT OF SPECIFIC MICRORNAS. 2013 18 356 34 ALTERING A HISTONE H3K4 METHYLATION PATHWAY IN GLOMERULAR PODOCYTES PROMOTES A CHRONIC DISEASE PHENOTYPE. METHYLATION OF SPECIFIC LYSINE RESIDUES IN CORE HISTONE PROTEINS IS ESSENTIAL FOR EMBRYONIC DEVELOPMENT AND CAN IMPART ACTIVE AND INACTIVE EPIGENETIC MARKS ON CHROMATIN DOMAINS. THE UBIQUITOUS NUCLEAR PROTEIN PTIP IS ENCODED BY THE PAXIP1 GENE AND IS AN ESSENTIAL COMPONENT OF A HISTONE H3 LYSINE 4 (H3K4) METHYLTRANSFERASE COMPLEX CONSERVED IN METAZOANS. IN ORDER TO DETERMINE IF PTIP AND ITS ASSOCIATED COMPLEXES ARE NECESSARY FOR MAINTAINING STABLE GENE EXPRESSION PATTERNS IN A TERMINALLY DIFFERENTIATED, NON-DIVIDING CELL, WE CONDITIONALLY DELETED PTIP IN GLOMERULAR PODOCYTES IN MICE. RENAL DEVELOPMENT AND FUNCTION WERE NOT IMPAIRED IN YOUNG MICE. HOWEVER, OLDER ANIMALS PROGRESSIVELY EXHIBITED PROTEINURIA AND PODOCYTE ULTRA STRUCTURAL DEFECTS SIMILAR TO CHRONIC GLOMERULAR DISEASE. LOSS OF PTIP RESULTED IN SUBTLE CHANGES IN GENE EXPRESSION PATTERNS PRIOR TO THE ONSET OF A RENAL DISEASE PHENOTYPE. CHROMATIN IMMUNOPRECIPITATION SHOWED A LOSS OF PTIP BINDING AND LOWER H3K4 METHYLATION AT THE NTRK3 (NEUROTROPHIC TYROSINE KINASE RECEPTOR, TYPE 3) LOCUS, WHOSE EXPRESSION WAS SIGNIFICANTLY REDUCED AND WHOSE FUNCTION MAY BE ESSENTIAL FOR PODOCYTE FOOT PROCESS PATTERNING. THESE DATA DEMONSTRATE THAT ALTERATIONS OR MUTATIONS IN AN EPIGENETIC REGULATORY PATHWAY CAN ALTER THE PHENOTYPES OF DIFFERENTIATED CELLS AND LEAD TO A CHRONIC DISEASE STATE. 2010 19 5994 40 TGFBETA-INCURRED EPIGENETIC ABERRATIONS OF MIRNA AND DNA METHYLTRANSFERASE SUPPRESS KLOTHO AND POTENTIATE RENAL FIBROSIS. RENAL FIBROSIS IS A COMMON PATHOLOGICAL FEATURE OF CHRONIC KIDNEY DISEASES (CKD) AND ITS DEVELOPMENT AND PROGRESSION ARE SIGNIFICANTLY AFFECTED BY EPIGENETIC MODIFICATIONS SUCH AS ABERRANT MIRNA AND DNA METHYLATION. KLOTHO IS AN ANTI-AGING AND ANTI-FIBROTIC PROTEIN AND ITS EARLY DECLINE AFTER RENAL INJURY IS REPORTEDLY ASSOCIATED WITH ABERRANT DNA METHYLATION. HOWEVER, THE KEY UPSTREAM PATHOLOGICAL MEDIATORS AND THE MOLECULAR CASCADE LEADING TO EPIGENETIC KLOTHO SUPPRESSION ARE NOT EXCLUSIVELY ESTABLISHED. HERE WE INVESTIGATE THE EPIGENETIC MECHANISM OF KLOTHO DEFICIENCY AND ITS FUNCTIONAL RELEVANCE IN RENAL FIBROGENESIS. FIBROTIC KIDNEYS INDUCED BY UNILATERAL URETERAL OCCLUSION (UUO) DISPLAYED MARKED KLOTHO SUPPRESSION AND THE PROMOTER HYPERMETHYLATION. THESE ABNORMALITIES WERE LIKELY DUE TO DEREGULATED TRANSFORMING GROWTH FACTOR-BETA (TGFBETA) SINCE TGFBETA ALONE CAUSED THE SIMILAR EPIGENETIC ABERRATIONS IN CULTURED RENAL CELLS AND TGFBETA BLOCKADE PREVENTED THE ALTERATIONS IN UUO KIDNEY. FURTHER INVESTIGATION REVEALED THAT TGFBETA ENHANCED DNA METHYLTRANSFERASE (DNMT) 1 AND DNMT3A VIA INHIBITING MIR-152 AND MIR-30A IN BOTH RENAL CELLS AND FIBROTIC KIDNEYS. ACCORDINGLY THE BLOCKADE OF EITHER TGFBETA SIGNALING OR DNMT1/3A ACTIVITIES SIGNIFICANTLY RECOVERED THE KLOTHO LOSS AND ATTENUATED PRO-FIBROTIC PROTEIN EXPRESSION AND RENAL FIBROSIS. MOREOVER, KLOTHO KNOCKDOWN BY RNA INTERFERENCES ABOLISHED THE ANTI-FIBROTIC EFFECTS OF DNMT INHIBITION IN BOTH TGFBETA-TREATED RENAL CELL AND UUO KIDNEY, INDICATING THAT TGFBETA-MEDIATED MIR-152/30A INHIBITIONS, DNMT1/3A ABERRATIONS AND SUBSEQUENT KLOTHO LOSS CONSTITUTE A CRITICAL REGULATORY LOOP THAT ELIMINATES KLOTHO'S ANTI-FIBROTIC ACTIVITIES AND POTENTIATES RENAL FIBROGENESIS. THUS, OUR STUDY ELABORATES A NOVEL EPIGENETIC CASCADE OF RENAL FIBROGENESIS AND REVEALS THE POTENTIAL THERAPEUTIC TARGETS FOR TREATING THE RENAL FIBROSIS-ASSOCIATED KIDNEY DISEASES. 2017 20 6661 38 UPREGULATION OF DNA METHYLTRANSFERASE-MEDIATED GENE SILENCING, ANCHORAGE-INDEPENDENT GROWTH, AND MIGRATION OF COLON CANCER CELLS BY INTERLEUKIN-6. INFLAMMATORY BOWEL DISEASE IS CHARACTERIZED BY CHRONIC INFLAMMATION WHICH PREDISPOSES TO COLORECTAL CANCER. THE MECHANISMS BY WHICH INFLAMMATION PROMOTES TUMORIGENESIS ARE NOT FULLY KNOWN. WE AIMED TO INVESTIGATE THE LINKS BETWEEN COLONIC INFLAMMATION AND TUMORIGENESIS VIA EPIGENETIC GENE SILENCING. COLON CANCER SPECIMENS WERE ASSESSED FOR THE EXPRESSION OF DNA METHYLTRANSFERASE-1 (DNMT-1) USING IMMUNOHISTOCHEMISTRY. COLORECTAL CARCINOMA CELL LINES WERE ASSESSED FOR DNMT1 EXPRESSION, METHYLCYTOSINE CONTENT, PROMOTER METHYLATION, GENE EXPRESSION, AND TUMORIGENESIS IN RESPONSE TO INTERLEUKIN (IL)-6. DNMT1 WAS EXPRESSED AT HIGHER LEVELS IN BOTH THE PERITUMORAL STROMA AND TUMOR IN INFLAMMATORY BOWEL DISEASE-ASSOCIATED CANCERS COMPARED WITH SPORADIC COLON CANCERS. IL-6 TREATMENT OF COLON CANCER CELLS RESULTED IN AN INCREASE IN DNMT1 EXPRESSION, INDEPENDENT OF DE NOVO GENE EXPRESSION. IL-6 INCREASED THE METHYLATION OF PROMOTER REGIONS OF GENES ASSOCIATED WITH TUMOR SUPPRESSION, ADHESION, AND APOPTOSIS RESISTANCE. EXPRESSION OF A SUBSET OF THESE GENES WAS DOWNREGULATED BY IL-6, AN EFFECT THAT WAS PREVENTED BY PREINCUBATION WITH 5-AZADEOXYCYTIDINE, A DNMT1 INHIBITOR. ANCHORAGE-INDEPENDENT GROWTH AND MIGRATION OF COLON CANCER CELLS WAS ALSO INCREASED BY IL-6 IN A 5-AZADEOXYCYTIDINE-SENSITIVE MANNER. OUR RESULTS INDICATE THAT DNMT-MEDIATED GENE SILENCING MAY PLAY A ROLE IN INFLAMMATION-ASSOCIATED COLON TUMORIGENESIS. 2010