1 5716 120 SIRT6 PROTECTS VASCULAR SMOOTH MUSCLE CELLS FROM OSTEOGENIC TRANSDIFFERENTIATION VIA RUNX2 IN CHRONIC KIDNEY DISEASE. VASCULAR CALCIFICATION (VC) IS REGARDED AS AN IMPORTANT PATHOLOGICAL CHANGE LACKING EFFECTIVE TREATMENT AND ASSOCIATED WITH HIGH MORTALITY. SIRTUIN 6 (SIRT6) IS A MEMBER OF THE SIRTUIN FAMILY, A CLASS III HISTONE DEACETYLASE AND A KEY EPIGENETIC REGULATOR. SIRT6 HAS A PROTECTIVE ROLE IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD). HOWEVER, THE EXACT ROLE AND MOLECULAR MECHANISM OF SIRT6 IN VC IN PATIENTS WITH CKD REMAIN UNCLEAR. HERE, WE DEMONSTRATED THAT SIRT6 WAS MARKEDLY DOWNREGULATED IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) AND IN THE RADIAL ARTERY TISSUE OF PATIENTS WITH CKD WITH VC. SIRT6-TRANSGENIC (SIRT6-TG) MICE SHOWED ALLEVIATED VC, WHILE VASCULAR SMOOTH MUSCLE CELL-SPECIFIC (VSMC-SPECIFIC) SIRT6 KNOCKED-DOWN MICE SHOWED SEVERE VC IN CKD. SIRT6 SUPPRESSED THE OSTEOGENIC TRANSDIFFERENTIATION OF VSMCS VIA REGULATION OF RUNT-RELATED TRANSCRIPTION FACTOR 2 (RUNX2). COIMMUNOPRECIPITATION (CO-IP) AND IMMUNOPRECIPITATION (IP) ASSAYS CONFIRMED THAT SIRT6 BOUND TO RUNX2. MOREOVER, RUNX2 WAS DEACETYLATED BY SIRT6 AND FURTHER PROMOTED NUCLEAR EXPORT VIA EXPORTIN 1 (XPO1), WHICH IN TURN CAUSED DEGRADATION OF RUNX2 THROUGH THE UBIQUITIN-PROTEASOME SYSTEM. THESE RESULTS DEMONSTRATED THAT SIRT6 PREVENTED VC BY SUPPRESSING THE OSTEOGENIC TRANSDIFFERENTIATION OF VSMCS, AND AS SUCH TARGETING SIRT6 MAY BE AN APPEALING THERAPEUTIC TARGET FOR VC IN CKD. 2022 2 5717 43 SIRTUIN-6-DEPENDENT GENETIC AND EPIGENETIC ALTERATIONS ARE ASSOCIATED WITH POOR CLINICAL OUTCOME IN HEPATOCELLULAR CARCINOMA PATIENTS. SIRTUIN 6 (SIRT6) IS A MEMBER OF THE SIRTUIN FAMILY OF NAD+-DEPENDENT DEACETYLASES. GENETIC DELETION OF SIRT6 IN MICE RESULTS IN A SEVERE DEGENERATIVE PHENOTYPE WITH IMPAIRED LIVER FUNCTION AND PREMATURE DEATH. THE ROLE OF SIRT6 IN DEVELOPMENT AND PROGRESSION OF HEPATOCELLULAR CARCINOMA IS CURRENTLY UNKNOWN. WE FIRST INVESTIGATED SIRT6 EXPRESSION IN 153 PRIMARY HUMAN LIVER CANCERS AND IN NORMAL AND CIRRHOTIC LIVERS USING MICROARRAY ANALYSIS. SIRT6 WAS SIGNIFICANTLY DOWN-REGULATED IN BOTH CIRRHOTIC LIVERS AND CANCER. A SIRT6 KNOCKOUT (KO) GENE EXPRESSION SIGNATURE WAS GENERATED FROM PRIMARY HEPATOCTYES ISOLATED FROM 3-WEEK-OLD SIRT6-DEFICIENT ANIMALS. SIRT6-DEFICIENT HEPATOCYTES SHOWED UP-REGULATION OF ESTABLISHED HEPATOCELLULAR CARCINOMA (HCC) BIOMARKERS ALPHA-FETOPROTEIN (AFP), INSULIN-LIKE GROWTH FACTOR 2 (IGF2), H19, AND GLYPICAN-3. FURTHERMORE, DECREASED SIRT6 EXPRESSION WAS OBSERVED IN HEPATOMA CELL LINES THAT ARE KNOWN TO BE APOPTOSIS-INSENSITIVE. RE-EXPRESSION OF SIRT6 IN HEPG2 CELLS INCREASED APOPTOSIS SENSITIVITY TO CD95-STIMULATION OR CHEMOTHERAPY TREATMENT. LOSS OF SIRT6 WAS CHARACTERIZED BY ONCOGENIC CHANGES, SUCH AS GLOBAL HYPOMETHYLATION, AS WELL AS METABOLIC CHANGES, SUCH AS HYPOGLYCEMIA AND INCREASED FAT DEPOSITION. THE HEPATOCYTE-SPECIFIC SIRT6-KO SIGNATURE HAD A PROGNOSTIC IMPACT AND WAS ENRICHED IN PATIENTS WITH POORLY DIFFERENTIATED TUMORS WITH HIGH AFP LEVELS AS WELL AS RECURRENT DISEASE. FINALLY, WE DEMONSTRATED THAT THE SIRT6-KO SIGNATURE POSSESSED A PREDICTIVE VALUE FOR TUMORS OTHER THAN HCC (E.G., BREAST AND LUNG CANCER). CONCLUSION: LOSS OF SIRT6 INDUCES EPIGENETIC CHANGES THAT MAY BE RELEVANT TO CHRONIC LIVER DISEASE AND HCC DEVELOPMENT. DOWN-REGULATION OF SIRT6 AND GENES DYSREGULATED BY LOSS OF SIRT6 POSSESS ONCOGENIC EFFECTS IN HEPATOCARCINOGENESIS. OUR DATA DEMONSTRATE THAT DEFICIENCY IN ONE EPIGENETIC REGULATOR PREDISPOSES A TUMORIGENIC PHENOTYPE THAT ULTIMATELY HAS RELEVANCE FOR OUTCOME OF HCC AND OTHER CANCER PATIENTS. 2013 3 3295 49 HIGH PHOSPHATE-INDUCED DOWNREGULATION OF PPARGAMMA CONTRIBUTES TO CKD-ASSOCIATED VASCULAR CALCIFICATION. MEDIAL ARTERIAL CALCIFICATION ASSOCIATED WITH HYPERPHOSPHATEMIA IS A MAIN CAUSE OF CARDIOVASCULAR MORTALITY IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD), BUT THE MECHANISMS UNDERLYING HIGH PHOSPHATE-INDUCED VASCULAR CALCIFICATION REMAIN LARGELY UNKNOWN. HERE, WE OBSERVED A SIGNIFICANT DECREASE IN THE EXPRESSION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR-GAMMA (PPARGAMMA) IN CALCIFIED ARTERIES BOTH IN CKD PATIENTS AND IN A MOUSE MODEL OF CKD WITH HYPERPHOSPHATEMIA. IN VITRO, HIGH PHOSPHATE TREATMENT LED TO A DECREASED EXPRESSION OF PPARGAMMA IN MOUSE VASCULAR SMOOTH MUSCLE CELLS (VMSCS), ACCOMPANIED BY APPARENT OSTEOGENIC DIFFERENTIATION AND CALCIFICATION. PRETREATMENT WITH PPARGAMMA AGONIST ROSIGLITAZONE SIGNIFICANTLY REVERSED HIGH PHOSPHATE-INDUCED VSMCS CALCIFICATION. FURTHER INVESTIGATION SHOWED THAT METHYL-CPG BINDING PROTEIN 2 (MECP2)-MEDIATED EPIGENETIC REPRESSION WAS INVOLVED IN HIGH PHOSPHATE-INDUCED PPARGAMMA DOWNREGULATION. MOREOVER, THE EXPRESSION OF KLOTHO THAT HAS THE ABILITY TO INHIBIT VASCULAR CALCIFICATION BY REGULATING PHOSPHATE UPTAKE DECREASED WITH THE PPARGAMMA REDUCTION IN VSMCS AFTER HIGH PHOSPHATE TREATMENT, AND ROSIGLITAZONE FAILED TO INHIBIT HIGH PHOSPHATE-INDUCED CALCIFICATION IN VSMCS WITH KNOCKDOWN OF KLOTHO OR IN AORTIC RINGS FROM KLOTHO-DEFICIENT (KL/KL) MICE. FINALLY, AN IN VIVO STUDY DEMONSTRATED THAT ORAL ADMINISTRATION OF ROSIGLITAZONE COULD INCREASE KLOTHO EXPRESSION AND PROTECT AGAINST HIGH PHOSPHATE-INDUCED VASCULAR CALCIFICATION IN CKD MICE. THESE FINDINGS SUGGEST THAT THE INHIBITION OF PPARGAMMA EXPRESSION MAY CONTRIBUTE TO THE PATHOGENESIS OF HIGH PHOSPHATE-INDUCED VASCULAR CALCIFICATION, WHICH MAY PROVIDE A NEW THERAPEUTIC TARGET FOR VASCULAR CALCIFICATION IN CKD PATIENTS. 2018 4 6658 44 UPREGULATED LNCRNA H19 SPONGES MIR-106A-5P AND CONTRIBUTES TO ALDOSTERONE-INDUCED VASCULAR CALCIFICATION VIA ACTIVATING THE RUNX2-DEPENDENT PATHWAY. BACKGROUND: EXCESS ALDOSTERONE IS IMPLICATED IN VASCULAR CALCIFICATION (VC), BUT THE MECHANISM BY WHICH ALDOSTERONE-MR (MINERALOCORTICOID RECEPTOR) COMPLEX PROMOTES VC IS UNCLEAR. EMERGING EVIDENCE INDICATES THAT LONG-NONCODING RNA H19 (H19) PLAYS A CRITICAL ROLE IN VC. WE EXAMINED WHETHER ALDOSTERONE-INDUCED OSTEOGENIC DIFFERENTIATION OF VASCULAR SMOOTH MUSCLE CELLS (VSMCS) THROUGH H19 EPIGENETIC MODIFICATION OF RUNX2 (RUNT-RELATED TRANSCRIPTION FACTOR-2) IN A MR-DEPENDENT MANNER. METHODS: WE INDUCED IN VIVO RAT MODEL OF CHRONIC KIDNEY DISEASE USING A HIGH ADENINE AND PHOSPHATE DIET TO EXPLORE THE RELATIONSHIP AMONG ALDOSTERONE, MR, H19, AND VC. WE ALSO CULTURED HUMAN AORTIC VSMCS TO EXPLORE THE ROLES OF H19 IN ALDOSTERONE-MR COMPLEX-INDUCED OSTEOGENIC DIFFERENTIATION AND CALCIFICATION OF VSMCS. RESULTS: H19 AND RUNX2 WERE SIGNIFICANTLY INCREASED IN ALDOSTERONE-INDUCED VSMC OSTEOGENIC DIFFERENTIATION AND VC, BOTH IN VITRO AND IN VIVO, WHICH WERE SIGNIFICANTLY BLOCKED BY THE MR ANTAGONIST SPIRONOLACTONE. MECHANISTICALLY, OUR FINDINGS REVEAL THAT THE ALDOSTERONE-ACTIVATED MR BOUND TO H19 PROMOTER AND INCREASED ITS TRANSCRIPTIONAL ACTIVITY, AS DETERMINED BY CHROMATIN IMMUNOPRECIPITATION, ELECTROPHORETIC MOBILITY SHIFT ASSAY, AND LUCIFERASE REPORTER ASSAY. SILENCING H19 INCREASED MICRORNA-106A-5P (MIR-106A-5P) EXPRESSION, WHICH SUBSEQUENTLY INHIBITED ALDOSTERONE-INDUCED RUNX2 EXPRESSION AT THE POSTTRANSCRIPTIONAL LEVEL. IMPORTANTLY, WE OBSERVED A DIRECT INTERACTION BETWEEN H19 AND MIR-106A-5P, AND DOWNREGULATION OF MIR-106A-5P EFFICIENTLY REVERSED THE SUPPRESSION OF RUNX2 INDUCED BY H19 SILENCING. CONCLUSIONS: OUR STUDY CLARIFIES A NOVEL MECHANISM BY WHICH UPREGULATION OF H19 CONTRIBUTES TO ALDOSTERONE-MR COMPLEX-PROMOTED RUNX2-DEPENDENT VSMC OSTEOGENIC DIFFERENTIATION AND VC THROUGH SPONGING MIR-106A-5P. THESE FINDINGS HIGHLIGHT A POTENTIAL THERAPEUTIC TARGET FOR ALDOSTERONE-INDUCED VC. 2023 5 364 44 AMELIORATION OF UREMIC TOXIN INDOXYL SULFATE-INDUCED OSTEOBLASTIC CALCIFICATION BY SET DOMAIN CONTAINING LYSINE METHYLTRANSFERASE 7/9 PROTEIN. BACKGROUND: VASCULAR CALCIFICATION (VC) IS A VERY COMMON PHENOMENON IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD). IT HAS BEEN REPORTED THAT SOME HISTONE METHYLATION PLAY A ROLE IN VC AS AN EPIGENETIC REGULATOR. INDOXYL SULFATE (IS) IS A PROTEIN-BOUND UREMIC TOXIN THAT HAS BEEN PROVEN AS ONE OF THE MAJOR RISK FACTORS OF CARDIOVASCULAR DISEASE IN CKD. SET DOMAIN CONTAINING LYSINE METHYLTRANSFERASE 7/9 (SET7/9) IS ONE OF THE IMPORTANT HISTONE METHYLTRANSFERASES. OBJECTIVES: THIS STUDY AIMED TO DETERMINE THE EFFECT OF IS ON THE EXPRESSION OF SET7/9 AND THE ROLE OF SET7/9 IN IS-INDUCED OSTEOBLASTIC DIFFERENTIATION AND CALCIFICATION OF VASCULAR SMOOTH MUSCLE CELLS (VSMCS). METHODS: VSMCS WERE INCUBATED WITH VARIOUS CONCENTRATIONS OF IS FOR DIFFERENT DURATIONS TO ASSESS OSTEOBLASTIC DIFFERENTIATION AND EXPRESSION OF SET7/9. WESTERN BLOT ANALYSIS AND QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION WERE PERFORMED TO ASSESS THE PROTEIN AND MRNA LEVELS OF SET7/9 RESPECTIVELY. THE CALCIUM CONTENT WAS MEASURED TO EVALUATE CALCIFICATION. RESULTS: OSTEOBLASTIC DIFFERENTIATION AND CALCIFICATION OF VSMCS AND DOWNREGULATION OF THE EXPRESSION OF SET7/9 WERE OBSERVED AFTER IS TREATMENT. THE AUTOPHAGY WAS ACTIVATED AFTER TREATMENT WITH IS, WHEREAS THE INHIBITION OF THE AUTOPHAGY PARTIALLY ATTENUATED THE EFFECT OF IS ON BOTH THE STIMULATION OF THE EXPRESSION OF RUNT-RELATED TRANSCRIPTION FACTOR 2 AND CALCIUM DEPOSITION. CONCLUSIONS: OUR DATA DEMONSTRATED THAT SET7/9 DOWNREGULATION AND AUTOPHAGY ACTIVATION MAY BE THE KEY MECHANISM OF IS-INDUCED VC IN CKD. 2019 6 5596 36 ROLES OF HISTONE ACETYLATION MODIFIERS AND OTHER EPIGENETIC REGULATORS IN VASCULAR CALCIFICATION. VASCULAR CALCIFICATION (VC) IS CHARACTERIZED BY CALCIUM DEPOSITION INSIDE ARTERIES AND IS CLOSELY ASSOCIATED WITH THE MORBIDITY AND MORTALITY OF ATHEROSCLEROSIS, CHRONIC KIDNEY DISEASE, DIABETES, AND OTHER CARDIOVASCULAR DISEASES (CVDS). VC IS NOW WIDELY KNOWN TO BE AN ACTIVE PROCESS OCCURRING IN VASCULAR SMOOTH MUSCLE CELLS (VSMCS) INVOLVING MULTIPLE MECHANISMS AND FACTORS. THESE MECHANISMS SHARE FEATURES WITH THE PROCESS OF BONE FORMATION, SINCE THE PHENOTYPE SWITCHING FROM THE CONTRACTILE TO THE OSTEOCHONDROGENIC PHENOTYPE ALSO OCCURS IN VSMCS DURING VC. IN ADDITION, VC CAN BE REGULATED BY EPIGENETIC FACTORS, INCLUDING DNA METHYLATION, HISTONE MODIFICATION, AND NONCODING RNAS. ALTHOUGH VC IS COMMONLY OBSERVED IN PATIENTS WITH CHRONIC KIDNEY DISEASE AND CVD, SPECIFIC DRUGS FOR VC HAVE NOT BEEN DEVELOPED. THUS, DISCOVERING NOVEL THERAPEUTIC TARGETS MAY BE NECESSARY. IN THIS REVIEW, WE SUMMARIZE THE CURRENT EXPERIMENTAL EVIDENCE REGARDING THE ROLE OF EPIGENETIC REGULATORS INCLUDING HISTONE DEACETYLASES AND PROPOSE THE THERAPEUTIC IMPLICATION OF THESE REGULATORS IN THE TREATMENT OF VC. 2020 7 3656 43 INDUCIBLE PRMT1 ABLATION IN ADULT VASCULAR SMOOTH MUSCLE LEADS TO CONTRACTILE DYSFUNCTION AND AORTIC DISSECTION. VASCULAR SMOOTH MUSCLE CELLS (VSMCS) HAVE REMARKABLE PLASTICITY IN RESPONSE TO DIVERSE ENVIRONMENTAL CUES. ALTHOUGH THESE CELLS ARE VERSATILE, CHRONIC STRESS CAN TRIGGER VSMC DYSFUNCTION, WHICH ULTIMATELY LEADS TO VASCULAR DISEASES SUCH AS AORTIC ANEURYSM AND ATHEROSCLEROSIS. PROTEIN ARGININE METHYLTRANSFERASE 1 (PRMT1) IS A MAJOR ENZYME CATALYZING ASYMMETRIC ARGININE DIMETHYLATION OF PROTEINS THAT ARE SOURCES OF ASYMMETRIC DIMETHYLARGININE (ADMA), AN ENDOGENOUS INHIBITOR OF NITRIC OXIDE SYNTHASE. ALTHOUGH A POTENTIAL ROLE OF PRMT1 IN VASCULAR PATHOGENESIS HAS BEEN PROPOSED, ITS ROLE IN VASCULAR FUNCTION HAS YET TO BE CLARIFIED. HERE, WE INVESTIGATED THE ROLE AND UNDERLYING MECHANISM OF PRMT1 IN VASCULAR SMOOTH MUSCLE CONTRACTILITY AND FUNCTION. THE EXPRESSION OF PRMT1 AND CONTRACTILE-RELATED GENES WAS SIGNIFICANTLY DECREASED IN THE AORTAS OF ELDERLY HUMANS AND PATIENTS WITH AORTIC ANEURYSMS. MICE WITH VSMC-SPECIFIC PRMT1 ABLATION (SMKO) EXHIBITED PARTIAL LETHALITY, LOW BLOOD PRESSURE AND AORTIC DILATION. THE PRMT1-ABLATED AORTAS SHOWED AORTIC DISSECTION WITH ELASTIC FIBER DEGENERATION AND CELL DEATH. EX VIVO AND IN VITRO ANALYSES INDICATED THAT PRMT1 ABLATION SIGNIFICANTLY DECREASED THE CONTRACTILITY OF THE AORTA AND TRACTION FORCES OF VSMCS. PRMT1 ABLATION DOWNREGULATED THE EXPRESSION OF CONTRACTILE GENES SUCH AS MYOCARDIN WHILE UPREGULATING THE EXPRESSION OF SYNTHETIC GENES, THUS CAUSING THE CONTRACTILE TO SYNTHETIC PHENOTYPIC SWITCH OF VSMCS. IN ADDITION, MECHANISTIC STUDIES DEMONSTRATED THAT PRMT1 DIRECTLY REGULATES MYOCARDIN GENE ACTIVATION BY MODULATING EPIGENETIC HISTONE MODIFICATIONS IN THE MYOCARDIN PROMOTER REGION. THUS, OUR STUDY DEMONSTRATES THAT VSMC PRMT1 IS ESSENTIAL FOR VASCULAR HOMEOSTASIS AND THAT ITS ABLATION CAUSES AORTIC DILATION/DISSECTION THROUGH IMPAIRED MYOCARDIN EXPRESSION. 2021 8 3654 45 INDOXYL SULFATE ACCELERATES VASCULAR SMOOTH MUSCLE CELL CALCIFICATION VIA MICRORNA-29B DEPENDENT REGULATION OF WNT/BETA-CATENIN SIGNALING. VASCULAR CALCIFICATION (VC) IS A VERY COMMON PHENOMENON IN PATIENTS WITH CHRONIC KIDNEY DISEASE(CKD) AND IT INCREASES THE INCIDENCE OF CARDIOVASCULAR DISEASE AND LEADS TO HIGH MORTALITY IN CKD PATIENTS. IT HAS BEEN REPORTED THAT SOME MICRORNAS (MIRS) PLAY ROLES IN VASCULAR CALCIFICATION AS AN EPIGENETIC REGULATOR. INDOXYL SULFATE (IS) IS A PROTEIN-BOUND UREMIC TOXIN WHICH HAS BEEN PROVEN AS ONE OF THE MAJOR RISK FACTORS OF CARDIOVASCULAR DISEASE IN CKD. HERE WE INVESTIGATED WHETHER MICRORNA-29B (MIR-29B) IS INVOLVED IN IS-INDUCED VASCULAR CALCIFICATION. WE FOUND THAT VASCULAR MIR-29B WAS DOWN-REGULATED IN RADIAL ARTERIES OF PATIENTS WITH END-STAGE RENAL DISEASE. CONSISTENTLY, IS ALSO DECREASED MIR-29B EXPRESSION IN HUMAN AORTIC SMOOTH MUSCLE CELLS (HASMCS) AND POTENTIATED THEIR CALCIFICATION. MIR-29B MIMICS SIGNIFICANTLY SUPPRESSED, WHILE MIR-29B ANTI-MIR MARKEDLY ENHANCED, IS-INDUCED RUNT-RELATED TRANSCRIPTION FACTOR 2 AND OSTEOPONTIN EXPRESSION. THE EXPRESSION OF WNT7B/BETA-CATENIN IN RADIAL ARTERIES WAS HIGHER IN END STAGE RENAL DISEASE THAN IN CONTROL GROUP, AND IS INCREASED WNT7B/BETA-CATENIN EXPRESSION IN HASMCS AS EARLY AS 3DAYS AFTER STIMULATION. FURTHERMORE, MIR-29B MIMICS POTENTLY REPRESSED WNT7B/BETA-CATENIN PROTEIN EXPRESSION IN HASMCS, WHEREAS MIR-29B ANTI-MIR INCREASED THEIR EXPRESSION, INDICATING MIR-29B INDEED NEGATIVELY REGULATES WNT7B/BETA-CATENIN SIGNALING. DICKKOPF-1 PROTEIN, THE WNT/BETA-CATENIN SIGNALING INHIBITOR, SUPPRESSED ANTI-MIR-29B-ENHANCED HASMCS CALCIFICATION. OUR DATA THUS INDICATE THAT MIR-29B DOWNREGULATION AND WNT/BETA-CATENIN SIGNALING ACTIVATION MAY BE THE KEY MECHANISM OF IS INDUCED VASCULAR CALCIFICATION IN CHRONIC KIDNEY DISEASE. 2018 9 141 38 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 10 3655 38 INDOXYL SULFATE ENHANCE THE HYPERMETHYLATION OF KLOTHO AND PROMOTE THE PROCESS OF VASCULAR CALCIFICATION IN CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS A STATE OF KLOTHO DEFICIENCY. THE KLOTHO EXPRESSION MAY BE SUPPRESSED DUE TO DNA HYPERMETHYLATION IN CANCER CELLS SO WE HAVE INVESTIGATED THE EFFECTS AND POSSIBLE MECHANISMS BY WHICH KLOTHO EXPRESSION IS REGULATED IN HUMAN AORTIC SMOOTH MUSCLE CELLS (HASMCS). THE VASCULAR KLOTHO HYPERMETHYLATION IN RADIAL ARTERIES OF PATIENTS WITH END-STAGE RENAL DISEASE WAS DESCRIBED. CULTURED HASMCS AND 5/6-NEPHRECTOMIZED SPRAGUE DAWLEY (SD) RATS TREATED WITH INDOXYL SULFATE (IS) WERE USED AS IN VITRO AND IN VIVO MODELS, RESPECTIVELY. IS INCREASED CPG HYPERMETHYLATION OF THE KLOTHO GENE AND DECREASED KLOTHO EXPRESSION IN HASMCS, AND POTENTIATED HASMCS CALCIFICATION. THE EXPRESSION OF DNA METHYLTRANSFERASE (DNMT) 1 AND 3A IN HASMCS TREATED WITH IS WAS SIGNIFICANTLY INCREASED AND SPECIFIC INHIBITION OF DNA METHYLTRANSFERASE 1 BY 5-AZA-2'-DEOXYCYTIDINE(5AZA-2DC) CAUSED DEMETHYLATION OF THE KLOTHO GENE AND INCREASED KLOTHO EXPRESSION. IN RATS, INJECTION OF IS POTENTIATED VASCULAR CALCIFICATION, INCREASED CPG HYPERMETHYLATION OF THE KLOTHO GENE AND DECREASED KLOTHO EXPRESSION IN THE AORTIC MEDIAL LAYER AND ALL OF THESE CHANGES COULD BE REVERTED BY 5AZA-2DC TREATMENT. TRANSCRIPTIONAL SUPPRESSION OF VASCULAR KLOTHO GENE EXPRESSION BY IS AND EPIGENETIC MODIFICATION OF KLOTHO BY IS MAY BE AN IMPORTANT PATHOLOGICAL MECHANISM OF VASCULAR CALCIFICATION IN CKD. 2016 11 1906 36 ENHANCER OF ZESTE HOMOLOG 2-CATALYSED H3K27 TRIMETHYLATION PLAYS A KEY ROLE IN ACUTE-ON-CHRONIC LIVER FAILURE VIA TNF-MEDIATED PATHWAY. ACUTE-ON-CHRONIC LIVER FAILURE IS MAINLY DUE TO HOST IMMUNITY SELF-DESTRUCTION. THE HISTONE H3 LYSINE 27 (H3K27) TRIMETHYLATING ENZYME, ENHANCER OF ZESTE HOMOLOG 2 (EZH2) MEDIATES EPIGENETIC SILENCING OF GENE EXPRESSION AND REGULATES IMMUNITY, ALSO INVOLVES PATHOGENESIS OF SEVERAL LIVER DISEASES. THE CURRENT STUDY WAS TO DETERMINE THE ROLE OF METHYLTRANSFERASE EZH2 AND ITS CATALYSED H3K27 TRIMETHYLATION (H3K27ME3) IN LIVER FAILURE, AND TO FURTHER INVESTIGATE THE POTENTIAL TARGET FOR LIVER FAILURE TREATMENT. EZH2 AND ITS CATALYSED H3K27ME3 WERE DETERMINED IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) FROM LIVER FAILURE PATIENTS AND KUPFFER CELLS FROM EXPERIMENTAL MICE. FURTHERMORE, GSK126 (AN INHIBITOR FOR EZH2 TRIMETHYLATION FUNCTION) WAS APPLIED IN LIVER FAILURE MICE IN VIVO, AND LIPOPOLYSACCHARIDE-STIMULATED MONONUCLEAR CELLS IN VITRO. EZH2 AND H3K27ME3 WERE SIGNIFICANTLY UPREGULATED IN HUMAN PBMC FROM LIVER FAILURE PATIENTS OR MURINE KUPFFER CELLS FROM THE LIVER FAILURE ANIMALS, RESPECTIVELY. GSK126 AMELIORATED DISEASE SEVERITY IN LIVER FAILURE MICE, WHICH MAYBE ATTRIBUTE TO DOWN-REGULATE CIRCULATING AND HEPATIC PROINFLAMMATORY CYTOKINES, ESPECIALLY TNF VIA REDUCING H3K27ME3. IN-DEPTH CHROMATIN IMMUNOPRECIPITATION ANALYSIS UNRAVELLED THAT DECREASED ENRICHMENT OF H3K27ME3 ON TNF PROMOTOR, RESULTING IN TNF ELEVATION IN KUPFFER CELLS FROM LIVER FAILURE MICE. NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND PROTEIN KINASE B (AKT) SIGNALLING PATHWAYS WERE ACTIVATED UPON LIPOPOLYSACCHARIDE STIMULATION, BUT ATTENUATED BY USING GSK126, ACCOMPANIED WITH DECREASED TNF IN VITRO. IN CONCLUSION, EZH2 AND H3K27ME3 CONTRIBUTED TO THE PATHOGENESIS OF LIVER FAILURE VIA TRIGGERING TNF AND OTHER INDISPENSABLE PROINFLAMMATORY CYTOKINES. EZH2 WAS TO MODIFY H3K27ME3 ENRICHMENT, AS WELL AS, ACTIVATION OF THE DOWNSTREAM NF-KAPPAB AND AKT SIGNALLING PATHWAYS. 2018 12 3720 34 INHIBITION OF CLASS I HISTONE DEACETYLASES ABROGATES TUMOR GROWTH FACTOR BETA EXPRESSION AND DEVELOPMENT OF FIBROSIS DURING CHRONIC PANCREATITIS. PANCREATIC FIBROSIS IS THE HALLMARK OF CHRONIC PANCREATITIS, A HIGHLY DEBILITATING DISEASE FOR WHICH THERE IS CURRENTLY NO CURE. THE KEY EVENT AT THE BASIS OF PANCREATIC FIBROSIS IS THE DEPOSITION OF EXTRACELLULAR MATRIX PROTEINS BY ACTIVATED PANCREATIC STELLATE CELLS (PSCS). TRANSFORMING GROWTH FACTOR BETA (TGFBETA) IS A POTENT PROFIBROTIC FACTOR IN THE PANCREAS AS IT PROMOTES THE ACTIVATION OF PSC; THUS, PHARMACOLOGIC INTERVENTIONS THAT EFFECTIVELY REDUCE TGFBETA EXPRESSION HARBOR CONSIDERABLE THERAPEUTIC POTENTIAL IN THE TREATMENT OF CHRONIC PANCREATITIS. IN THIS STUDY, WE INVESTIGATED WHETHER TGFBETA EXPRESSION IS REDUCED BY PHARMACOLOGIC INHIBITION OF THE EPIGENETIC MODIFIERS HISTONE DEACETYLASES (HDACS). TO ADDRESS THIS AIM, CHRONIC PANCREATITIS WAS INDUCED IN C57BL/6 MICE WITH SERIAL INJECTIONS OF CERULEIN, AND THE SELECTIVE CLASS 1 HDAC INHIBITOR MS-275 WAS ADMINISTERED IN VIVO IN A PREVENTIVE AND THERAPEUTIC MANNER. BOTH MS-275 REGIMENS POTENTLY REDUCED DEPOSITION OF EXTRACELLULAR MATRIX AND DEVELOPMENT OF FIBROSIS IN THE PANCREAS AFTER 4 WEEKS OF CHRONIC PANCREATITIS. REDUCED PANCREATIC FIBROSIS WAS CONCOMITANT WITH LOWER EXPRESSION OF PANCREATIC TGFBETA AND CONSEQUENT REDUCED PSC ACTIVATION. IN SEARCH OF THE CELL TYPES TARGETED BY THE INHIBITOR, WE FOUND THAT MS-275 TREATMENT ABROGATED THE EXPRESSION OF TGFBETA IN ACINAR CELLS STIMULATED BY CERULEIN TREATMENT. OUR STUDY DEMONSTRATES THAT MS-275 IS AN EFFECTIVE ANTIFIBROTIC AGENT IN THE CONTEXT OF EXPERIMENTAL CHRONIC PANCREATITIS AND THUS MAY CONSTITUTE A VALID THERAPEUTIC INTERVENTION FOR THIS SEVERE DISEASE. 2018 13 4772 36 NUCLEAR SIRTUINS AND INFLAMMATORY SIGNALING PATHWAYS. THE REGULATION OF CHRONIC INFLAMMATION HAS RECEIVED CONSIDERABLE RESEARCH ATTENTION IN RECENT YEARS BECAUSE OF ITS CONTRIBUTION TO THE PATHOGENESIS OF CHRONIC DISEASES SUCH AS ARTHRITIS, DIABETES, METABOLIC SYNDROME AND OBESITY. THUS, STRATEGIES THAT INHIBIT THE INFLAMMATORY STATE MAY BE BENEFICIAL IN IMPROVING THE PATHOPHYSIOLOGY OF SEVERAL INFLAMMATION-RELATED DISORDERS. SIRTUINS ARE A FAMILY OF HISTONE DEACETYLASES THAT CONTAIN SEVEN ENZYMATIC ACTIVITIES IN MAMMALS (SIRT1-SIRT7) AND FUNCTION TO SUPPRESS GENE TRANSCRIPTION BY EPIGENETIC MECHANISMS. NUCLEAR SIRTUINS (SIRT 1, 2, 6 AND 7) IN PARTICULAR MAY PLAY AN IMPORTANT ROLE IN THE REGULATION OF INFLAMMATORY RESPONSES. IN THE PRESENT REVIEW, WE ASSESSED THE ROLES OF NUCLEAR SIRTUINS IN INFLAMMATORY REACTIONS: SIRT1 HAS BEEN SHOWN TO SUPPRESS NF-KAPPAB ACTIVITY, THE MASTER REGULATOR OF CELLULAR INFLAMMATORY RESPONSE, DECREASE COX-2 AND INOS PRODUCTION, AND INCREASE ANTIOXIDANT GENE EXPRESSION THAT SUPPRESSED INFLAMMATION. SIRT2 ACTIVITY INCLUDED THE DEACETYLATION OF P65 SUBUNIT OF NF-KAPPABETA AND RIP-1, WHILE SIRT6 HAS BEEN SHOWN TO INTERACT WITH P65/RELA BOUND TO THE NF-KAPPABETA PROMOTER REGION AND REPRESS TRANSCRIPTIONAL ACTIVITY. FURTHERMORE, RECENT STUDIES HAVE SHOWN THAT THE ABSENCE OF SIRT7 PRODUCED AN INCREASE IN INFLAMMATION, ILLUSTRATING THAT SIRT7 ALSO FUNCTIONED TO DECREASE INFLAMMATION. GIVEN THEIR SIGNIFICANT ROLES IN THE REGULATION OF CHRONIC INFLAMMATION, NUCLEAR SIRTUINS REPRESENT POTENTIAL THERAPEUTIC TARGETS IN THE CONTROL OF CHRONIC INFLAMMATORY DISEASES. 2017 14 3935 41 LIVER-SPECIFIC KNOCKDOWN OF CLASS IIA HDACS HAS LIMITED EFFICACY ON GLUCOSE METABOLISM BUT ENTAILS SEVERE ORGAN SIDE EFFECTS IN MICE. HISTONE DEACETYLASES (HDACS) ARE IMPORTANT REGULATORS OF EPIGENETIC GENE MODIFICATION THAT ARE INVOLVED IN THE TRANSCRIPTIONAL CONTROL OF METABOLISM. IN PARTICULAR CLASS IIA HDACS HAVE BEEN SHOWN TO AFFECT HEPATIC GLUCONEOGENESIS AND PREVIOUS APPROACHES REVEALED THAT THEIR INHIBITION REDUCES BLOOD GLUCOSE IN TYPE 2 DIABETIC MICE. IN THE PRESENT STUDY, WE AIMED TO EVALUATE THE POTENTIAL OF CLASS IIA HDAC INHIBITION AS A THERAPEUTIC OPPORTUNITY FOR THE TREATMENT +OF METABOLIC DISEASES. FOR THAT, SIRNAS SELECTIVELY TARGETING HDAC4, 5 AND 7 WERE SELECTED AND USED TO ACHIEVE A COMBINATORIAL KNOCKDOWN OF THESE THREE CLASS IIA HDAC ISOFORMS. SUBSEQUENTLY, THE HEPATOCELLULAR EFFECTS AS WELL AS THE IMPACT ON GLUCOSE AND LIPID METABOLISM WERE ANALYZED IN VITRO AND IN VIVO. THE TRIPLE KNOCKDOWN RESULTED IN A STATISTICALLY SIGNIFICANT DECREASE OF GLUCONEOGENIC GENE EXPRESSION IN MURINE AND HUMAN HEPATOCYTE CELL MODELS. A SIMILAR HDAC-INDUCED DOWNREGULATION OF HEPATIC GLUCONEOGENESIS GENES COULD BE ACHIEVED IN MICE USING A LIVER-SPECIFIC LIPID NANOPARTICLE SIRNA FORMULATION. HOWEVER, THE EFFICACY ON WHOLE BODY GLUCOSE METABOLISM ASSESSED BY PYRUVATE-TOLERANCE TESTS WERE ONLY LIMITED AND DID NOT OUTWEIGH THE SAFETY FINDINGS OBSERVED BY HISTOPATHOLOGICAL ANALYSIS IN SPLEEN AND KIDNEY. MECHANISTICALLY, AFFYMETRIX GENE EXPRESSION STUDIES PROVIDE EVIDENCE THAT CLASS IIA HDACS DIRECTLY TARGET OTHER KEY FACTORS BEYOND THE DESCRIBED FORKHEAD BOX (FOXP) TRANSCRIPTION REGULATORS, SUCH AS HEPATOCYTE NUCLEAR FACTOR 4 ALPHA (HNF4A). DOWNSTREAM OF THESE FACTORS SEVERAL ADDITIONAL PATHWAYS WERE REGULATED NOT MERELY INCLUDING GLUCOSE AND LIPID METABOLISM AND TRANSPORT. IN CONCLUSION, THE LIVER-DIRECTED COMBINATORIAL KNOCKDOWN OF HDAC4, 5 AND 7 BY THERAPEUTIC SIRNAS AFFECTED MULTIPLE PATHWAYS IN VITRO, LEADING IN VIVO TO THE DOWNREGULATION OF GENES INVOLVED IN GLUCONEOGENESIS. HOWEVER, THE EFFECTS ON GENE EXPRESSION LEVEL WERE NOT PARALLELED BY A SIGNIFICANT REDUCTION OF GLUCONEOGENESIS IN MICE. COMBINED KNOCKDOWN OF HDAC ISOFORMS WAS ASSOCIATED WITH SEVERE ADVERSE EFFECTS IN VIVO, CHALLENGING THIS APPROACH AS A TREATMENT OPTION FOR CHRONIC METABOLIC DISORDERS LIKE TYPE 2 DIABETES. 2020 15 2825 40 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 16 446 35 APABETALONE DOWNREGULATES FIBROTIC, INFLAMMATORY AND CALCIFIC PROCESSES IN RENAL MESANGIAL CELLS AND PATIENTS WITH RENAL IMPAIRMENT. EPIGENETIC MECHANISMS ARE IMPLICATED IN TRANSCRIPTIONAL PROGRAMS DRIVING CHRONIC KIDNEY DISEASE (CKD). APABETALONE IS AN ORALLY AVAILABLE INHIBITOR OF BROMODOMAIN AND EXTRATERMINAL (BET) PROTEINS, WHICH ARE EPIGENETIC READERS THAT MODULATE GENE EXPRESSION. IN THE PHASE 3 BETONMACE TRIAL, APABETALONE REDUCED RISK OF MAJOR ADVERSE CARDIAC EVENTS (MACE) BY 50% IN THE CKD SUBPOPULATION, INDICATING FAVORABLE EFFECTS ALONG THE KIDNEY-HEART AXIS. ACTIVATION OF HUMAN RENAL MESANGIAL CELLS (HRMCS) TO A CONTRACTILE PHENOTYPE THAT OVERPRODUCES EXTRACELLULAR MATRIX (ECM) AND INFLAMMATORY CYTOKINES, AND PROMOTES CALCIFICATION, FREQUENTLY ACCOMPANIES CKD TO DRIVE PATHOLOGY. HERE, WE SHOW APABETALONE DOWNREGULATED HRMC ACTIVATION WITH TGF-BETA1 STIMULATION BY SUPPRESSING TGF-BETA1-INDUCED ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION, ALPHA-SMA ASSEMBLY INTO STRESS FIBERS, ENHANCED CONTRACTION, COLLAGEN OVERPRODUCTION, AND EXPRESSION OF KEY DRIVERS OF FIBROSIS, INFLAMMATION, OR CALCIFICATION INCLUDING THROMBOSPONDIN, FIBRONECTIN, PERIOSTIN, SPARC, INTERLEUKIN 6, AND ALKALINE PHOSPHATASE. LIPOPOLYSACCHARIDE-STIMULATED EXPRESSION OF INFLAMMATORY GENES IL6, IL1B, AND PTGS2 WAS ALSO SUPPRESSED. TRANSCRIPTOMICS CONFIRMED APABETALONE AFFECTED GENE SETS OF ECM REMODELING AND INTEGRINS. CLINICAL TRANSLATION OF IN VITRO RESULTS WAS INDICATED IN CKD PATIENTS WHERE A SINGLE DOSE OF APABETALONE REDUCED PLASMA LEVELS OF KEY PRO-FIBROTIC AND INFLAMMATORY MARKERS, AND INDICATED INHIBITION OF TGF-BETA1 SIGNALING. WHILE PLASMA PROTEINS CANNOT BE TRACED TO THE KIDNEY ALONE, ANTI-FIBROTIC AND ANTI-INFLAMMATORY EFFECTS OF APABETALONE IDENTIFIED IN THIS STUDY ARE CONSISTENT WITH THE OBSERVED DECREASE IN CARDIOVASCULAR RISK IN CKD PATIENTS. 2023 17 5994 38 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 18 5795 29 STAT3 INDUCTION OF MIR-146B FORMS A FEEDBACK LOOP TO INHIBIT THE NF-KAPPAB TO IL-6 SIGNALING AXIS AND STAT3-DRIVEN CANCER PHENOTYPES. INTERLEUKIN-6 (IL-6)-MEDIATED ACTIVATION OF SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) IS A MECHANISM BY WHICH CHRONIC INFLAMMATION CAN CONTRIBUTE TO CANCER AND IS A COMMON ONCOGENIC EVENT. WE DISCOVERED A PATHWAY, THE LOSS OF WHICH IS ASSOCIATED WITH PERSISTENT STAT3 ACTIVATION IN HUMAN CANCER. WE FOUND THAT THE GENE ENCODING THE TUMOR SUPPRESSOR MICRORNA MIR-146B IS A DIRECT STAT3 TARGET GENE, AND ITS EXPRESSION WAS INCREASED IN NORMAL BREAST EPITHELIAL CELLS BUT DECREASED IN TUMOR CELLS. METHYLATION OF THE MIR-146B PROMOTER, WHICH INHIBITED STAT3-MEDIATED INDUCTION OF EXPRESSION, WAS INCREASED IN PRIMARY BREAST CANCERS. MOREOVER, WE FOUND THAT MIR-146B INHIBITED NUCLEAR FACTOR KAPPAB (NF-KAPPAB)-DEPENDENT PRODUCTION OF IL-6, SUBSEQUENT STAT3 ACTIVATION, AND IL-6/STAT3-DRIVEN MIGRATION AND INVASION IN BREAST CANCER CELLS, THEREBY ESTABLISHING A NEGATIVE FEEDBACK LOOP. IN ADDITION, HIGHER EXPRESSION OF MIR-146B WAS POSITIVELY CORRELATED WITH PATIENT SURVIVAL IN BREAST CANCER SUBTYPES WITH INCREASED IL6 EXPRESSION AND STAT3 PHOSPHORYLATION. OUR RESULTS IDENTIFY AN EPIGENETIC MECHANISM OF CROSSTALK BETWEEN STAT3 AND NF-KAPPAB RELEVANT TO CONSTITUTIVE STAT3 ACTIVATION IN MALIGNANCY AND THE ROLE OF INFLAMMATION IN ONCOGENESIS. 2014 19 2748 33 EXPRESSION AND FUNCTION OF EZH2 IN SYNOVIAL FIBROBLASTS: EPIGENETIC REPRESSION OF THE WNT INHIBITOR SFRP1 IN RHEUMATOID ARTHRITIS. OBJECTIVES: TO STUDY THE EXPRESSION, REGULATION AND FUNCTION OF THE HISTONE METHYLTRANSFERASE ENHANCER OF ZESTE HOMOLOGUE 2 (EZH2) IN SYNOVIAL FIBROBLASTS (SF) FROM PATIENTS WITH RHEUMATOID ARTHRITIS (RA) AND OSTEOARTHRITIS (OA). METHODS: SF WERE OBTAINED FROM RA AND OA PATIENTS UNDERGOING JOINT SURGERY. EXPRESSION LEVELS WERE ASSESSED BY QUANTITATIVE REAL-TIME PCR AND WESTERN BLOT. KINASE INHIBITORS AND REPORTER GENE ASSAYS WERE EMPLOYED TO STUDY SIGNALLING PATHWAYS. FUNCTIONAL ANALYSES INCLUDED EZH2 OVEREXPRESSION BY PLASMID TRANSFECTION AND GENE SILENCING BY SMALL INTERFERING RNA. CHROMATIN IMMUNOPRECIPITATION ASSAY WAS USED TO ANALYSE HISTONE METHYLATION WITHIN DISTINCT PROMOTER REGIONS. RESULTS: BY STUDYING THE EXPRESSION AND FUNCTION OF EZH2 IN SF THE AUTHORS FOUND THAT EZH2 IS OVEREXPRESSED IN RHEUMATOID ARTHRITIS SYNOVIAL FIBROBLASTS (RASF) AND FURTHER INDUCED BY TUMOUR NECROSIS FACTOR ALPHA THROUGH THE NUCLEAR FACTOR KAPPA B AND JUN KINASE PATHWAYS. AS A TARGET GENE OF EZH2 THE AUTHORS IDENTIFIED SECRETED FRIZZLED-RELATED PROTEIN 1 (SFRP1), AN INHIBITOR OF WNT SIGNALLING, WHICH IS ASSOCIATED WITH THE ACTIVATION OF RASF, AND SHOW THAT SFRP1 EXPRESSION CORRELATES WITH THE OCCUPATION OF ITS PROMOTER WITH ACTIVATING AND SILENCING HISTONE MARKS. CONCLUSIONS: THESE DATA STRONGLY SUGGEST THAT THE CHRONIC INFLAMMATORY ENVIRONMENT OF THE RA JOINT INDUCES EZH2 AND THUS MIGHT CAUSE CHANGES IN THE EPIGENETIC PROGRAMMES OF SF. 2011 20 3795 31 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