1 3036 135 GENISTEIN AMELIORATES RENAL FIBROSIS THROUGH REGULATION SNAIL VIA M6A RNA DEMETHYLASE ALKBH5. RENAL TUBULE-INTERSTITIAL FIBROSIS IS RELATED TO CHRONIC KIDNEY DISEASE PROGRESSION AND A TYPICAL FEATURE OF THE AGING KIDNEY. EPIGENETIC MODIFICATIONS OF FIBROSIS-PRONE GENES REGULATE THE DEVELOPMENT OF RENAL FIBROSIS. AS A KIND OF "EPIGENETIC DIET", SOY ISOFLAVONE GENISTEIN WAS REPORTED TO HAVE RENAL PROTECTIVE ACTION AND EPIGENETIC-MODULATING EFFECTS. HOWEVER, ITS RENAL PROTECTION ROLE AND UNDERLYING MECHANISMS ARE YET TO BE FULLY CLARIFIED. HEREIN, WE SHOWED THAT GENISTEIN EXHIBITS A DEMONSTRABLE ANTI-FIBROTIC EFFECT ON KIDNEY IN VIVO UUO (UNILATERAL URETERAL OCCLUSION) MODEL AND RENAL EPITHELIAL CELLS IN VITRO MODEL. THE MECHANISM IS STRONGLY ASSOCIATED WITH EPITHELIAL-TO-MESENCHYMAL TRANSITION AND M6A RNA DEMETHYLASE ALKBH5. MOUSE FIBROTIC KIDNEYS INDUCED BY UUO EXHIBITED ADVERSE EXPRESSION OF RENAL FIBROSIS-RELATED PROTEINS AND SIGNIFICANT INCREASES IN THE TOTAL M6A LEVEL. AS AN ERASER, ALKBH5 SHOWED SEVERER SUPPRESSION IN THE RENAL FIBROSIS PROCESS. HOWEVER, GENISTEIN PRETREATMENT RESTORED ALKBH5 LOSS REMARKABLY AND REDUCED RENAL FIBROSIS, ABNORMAL PROTEIN, AND INFLAMMATORY MARKERS. THE EXAMINATION OF POSSIBLE MECHANISMS REVEALED THAT GENISTEIN PROMOTED ALKBH5 AND MAYBE INDUCED THE LEVEL OF MRNA M6A METHYLATION IN SOME EPITHELIAL-TO-MESENCHYMAL TRANSITION-RELATED TRANSCRIPTION FACTORS. WE FOUND SNAIL WAS THE CRITICAL REGULATOR AND CRITICAL FOR THE PROTECTIVE ROLE OF GENISTEIN. TO VERIFY THE RELATIONSHIP BETWEEN ALKBH5 AND SNAIL, WE GENERATED KNOCKDOWN AND OVEREXPRESSION OF ALKBH5 CELLS IN VITRO. ALKBH5 KNOCKDOWN ENHANCED THE MESENCHYMAL PHENOTYPE MARKER ALPHA-SMOOTH MUSCLE ACTIN AND SNAIL EXPRESSION. IN AGREEMENT, OVEREXPRESSION ALKBH5 INCREASED EPITHELIAL ADHESION MOLECULE E-CADHERIN AND REDUCED SNAIL EXPRESSION. IN CONCLUSION, GENISTEIN INCREASED RENAL ALKBH5 EXPRESSION IN UUO-INDUCED RENAL FIBROSIS AND REDUCED RNA M6A LEVELS AND AMELIORATES RENAL DAMAGES. 2020 2 3889 61 KLOTHO RECOVERY BY GENISTEIN VIA PROMOTER HISTONE ACETYLATION AND DNA DEMETHYLATION MITIGATES RENAL FIBROSIS IN MICE. RENAL FIBROSIS IS A COMMON HISTOMORPHOLOGICAL FEATURE OF RENAL AGING AND CHRONIC KIDNEY DISEASES OF ALL ETIOLOGIES, AND ITS INITIATION AND PROGRESSION ARE SUBSTANTIALLY INFLUENCED BY ABERRANT EPIGENETIC MODIFICATIONS OF FIBROSIS-SUSCEPTIBLE GENES, YET WITHOUT EFFECTIVE THERAPY. "EPIGENETIC DIETS" EXHIBIT TISSUE-PROTECTIVE AND EPIGENETIC-MODULATING PROPERTIES; HOWEVER, THEIR ANTI-RENAL FIBROSIS FUNCTIONS AND THE UNDERLYING MECHANISMS ARE LESS UNDERSTOOD. IN THIS STUDY, WE SHOW THAT GENISTEIN, A PHYTOESTROGENIC ISOFLAVONE ENRICHED IN DIETARY SOY PRODUCTS, EXHIBITS IMPRESSIVE ANTI-RENAL FIBROSIS ACTIVITIES BY RECOVERING EPIGENETIC LOSS OF KLOTHO, A KIDNEY-ENRICHED ANTI-AGING AND FIBROSIS-SUPPRESSING PROTEIN. MOUSE FIBROTIC KIDNEYS INDUCED BY UUO (UNILATERAL URETERAL OCCLUSION) DISPLAYED SEVERER KLOTHO SUPPRESSION AND ADVERSE EXPRESSION OF RENAL FIBROSIS-ASSOCIATED PROTEINS, BUT GENISTEIN ADMINISTRATION MARKEDLY RECOVERED THE KLOTHO LOSS AND ATTENUATED RENAL FIBROSIS AND THE PROTEIN EXPRESSION ABNORMALITIES. THE EXAMINATION OF POSSIBLE CAUSES OF THE KLOTHO RECOVERY REVEALED THAT GENISTEIN SIMULTANEOUSLY INHIBITED HISTONE 3 DEACETYLATION OF KLOTHO PROMOTER AND NORMALIZED THE PROMOTER DNA HYPERMETHYLATION BY SUPPRESSING ELEVATED DNA METHYLTRANSFERASE DNMT1 AND DNMT3A. MORE IMPORTANTLY, GENISTEIN'S ANTI-RENAL FIBROSIS EFFECTS ON THE RENAL FIBROTIC LESIONS AND THE ABNORMAL EXPRESSIONS OF FIBROSIS-ASSOCIATED PROTEINS WERE ABROGATED WHEN KLOTHO IS KNOCKDOWN BY RNA INTERFERENCES IN UUO MICE. THUS, OUR RESULTS IDENTIFY KLOTHO RESTORATION VIA EPIGENETIC HISTONE ACETYLATION AND DNA DEMETHYLATION AS A CRITICAL MECHANISM OF GENISTEIN'S ANTI-FIBROSIS FUNCTION AND SHED NEW LIGHTS ON THE POTENTIALS OF EPIGENETIC DIETS IN PREVENTING OR TREATING AGING OR RENAL FIBROSIS-ASSOCIATED KIDNEY DISEASES. KEY MESSAGES: GENISTEIN PREVENTS RENAL FIBROSIS AND THE ASSOCIATED KLOTHO SUPPRESSION IN UUO MICE. GENISTEIN UPREGULATES KLOTHO IN PART BY REVERSING THE PROMOTER HISTONE 3 HYPOACETYLATION. GENISTEIN ALSO PRESERVES KLOTHO VIA RELIEVING KLOTHO PROMOTER HYPERMETHYLATION. GENISTEIN DEMETHYLATES KLOTHO PROMOTER BY INHIBITING ABERRANT DNMT1/3A EXPRESSION. GENISTEIN RESTORATION OF KLOTHO IS ESSENTIAL FOR ITS ANTI-RENAL FIBROSIS FUNCTION. 2019 3 5994 55 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 4 6058 42 THE DEFICIENCY OF N6-METHYLADENOSINE DEMETHYLASE ALKBH5 ENHANCES THE NEURODEGENERATIVE DAMAGE INDUCED BY COBALT. COBALT EXPOSURE, EVEN AT LOW CONCENTRATIONS, INDUCES NEURODEGENERATIVE DAMAGE, SUCH AS ALZHEIMER'S DISEASE (AD). THE SPECIFIC UNDERLYING MECHANISMS REMAIN UNCLEAR. OUR PREVIOUS STUDY DEMONSTRATED THAT M(6)A METHYLATION ALTERATION IS INVOLVED IN COBALT-INDUCED NEURODEGENERATIVE DAMAGE, SUCH AS IN AD. HOWEVER, THE ROLE OF M(6)A RNA METHYLATION AND ITS UNDERLYING MECHANISMS ARE POORLY UNDERSTOOD. IN THIS STUDY, BOTH EPIDEMIOLOGICAL AND LABORATORY STUDIES SHOWED THAT COBALT EXPOSURE COULD DOWNREGULATE THE EXPRESSION OF THE M(6)A DEMETHYLASE ALKBH5, SUGGESTING A KEY ROLE FOR ALKBH5. MOREOVER, METHYLATED RNA IMMUNOPRECIPITATION AND SEQUENCING (MERIP-SEQ) ANALYSIS REVEALED THAT ALKBH5 DEFICIENCY IS ASSOCIATED WITH NEURODEGENERATIVE DISEASES. KEGG PATHWAY AND GENE ONTOLOGY ANALYSES FURTHER REVEALED THAT THE DIFFERENTIALLY M(6)A-MODIFIED GENES RESULTING FROM ALKBH5 DOWNREGULATION AND COBALT EXPOSURE WERE AGGREGATED IN THE PATHWAYS OF PROLIFERATION, APOPTOSIS, AND AUTOPHAGY. SUBSEQUENTLY, ALKBH5 DEFICIENCY WAS SHOWN TO EXACERBATE CELL VIABILITY DECLINE, MOTIVATE CELL APOPTOSIS AND ATTENUATE CELL AUTOPHAGY INDUCED BY COBALT WITH EXPERIMENTAL TECHNIQUES OF GENE OVEREXPRESSION/INHIBITION. IN ADDITION, MORPHOLOGICAL CHANGES IN NEURONS AND THE EXPRESSION OF AD-RELATED PROTEINS, SUCH AS APP, P-TAU, AND TAU, IN THE CEREBRAL HIPPOCAMPUS OF WILD-TYPE AND ALKBH5 KNOCKOUT MICE AFTER CHRONIC COBALT EXPOSURE WERE ALSO INVESTIGATED. BOTH IN VITRO AND IN VIVO RESULTS SHOWED THAT LOWER EXPRESSION OF ALKBH5 AGGRAVATED COBALT-INDUCED NEURODEGENERATIVE DAMAGE. THESE RESULTS SUGGEST THAT ALKBH5, AS AN EPIGENETIC REGULATOR, COULD BE A POTENTIAL TARGET FOR ALLEVIATING COBALT-INDUCED NEURODEGENERATIVE DAMAGE. IN ADDITION, WE PROPOSE A NOVEL STRATEGY FOR THE PREVENTION AND TREATMENT OF ENVIRONMENTAL TOXICANT-RELATED NEURODEGENERATION FROM AN EPIGENETIC PERSPECTIVE. 2023 5 476 49 ARSENIC INDUCES FIBROGENIC CHANGES IN HUMAN KIDNEY EPITHELIAL CELLS POTENTIALLY THROUGH EPIGENETIC ALTERATIONS IN DNA METHYLATION. ARSENIC CONTAMINATION IS A SIGNIFICANT PUBLIC HEALTH ISSUE, AND KIDNEY IS ONE OF THE TARGET ORGAN FOR ARSENIC-INDUCED ADVERSE EFFECTS. RENAL FIBROSIS IS A WELL-KNOWN PATHOLOGICAL STAGE FREQUENTLY OBSERVED IN PROGRESSIVE CHRONIC KIDNEY DISEASE (CKD). EPIDEMIOLOGICAL STUDIES IMPLICATE ARSENIC EXPOSURE TO CKD, BUT THE ROLE OF ARSENIC IN KIDNEY FIBROSIS AND THE UNDERLYING MECHANISM IS STILL UNCLEAR. IT IS IN THIS CONTEXT THAT THE CURRENT STUDY EVALUATED THE EFFECTS OF LONG-TERM ARSENIC EXPOSURE ON THE CELLULAR RESPONSE IN MORPHOLOGY, AND MARKER GENES EXPRESSION WITH RESPECT TO FIBROSIS USING HUMAN KIDNEY 2 (HK-2) EPITHELIAL CELLS. RESULTS OF THIS STUDY REVEALED THAT IN ADDITION TO INCREASED GROWTH, HK-2 CELLS UNDERWENT PHENOTYPIC, BIOCHEMICAL AND MOLECULAR CHANGES INDICATIVE OF EPITHELIAL-MESENCHYMAL TRANSITION (EMT) IN RESPONSE TO THE EXPOSURE TO ARSENIC. MOST IMPORTANTLY, THE ARSENIC-EXPOSED CELLS ACQUIRED THE PATHOGENIC FEATURES OF FIBROSIS AS SUPPORTED BY INCREASED EXPRESSION OF MARKERS FOR FIBROSIS, SUCH AS COLLAGEN I, FIBRONECTIN, TRANSFORMING GROWTH FACTOR BETA, AND ALPHA-SMOOTH MUSCLE ACTIN. UPREGULATION OF FIBROSIS ASSOCIATED SIGNALING MOLECULES SUCH AS TISSUE INHIBITOR OF METALLOPROTEINASES-3 AND MATRIX METALLOPROTEINASE-2 AS WELL AS ACTIVATION OF AKT WAS ALSO OBSERVED. ADDITIONALLY, THE EXPRESSION OF EPIGENETIC GENES (DNA METHYLTRANSFERASES 3A AND 3B; METHYL-CPG BINDING DOMAIN 4) WAS INCREASED IN ARSENIC-EXPOSED CELLS. TREATMENT WITH DNA METHYLATION INHIBITOR 5-AZA-2'-DC REVERSED THE EMT PROPERTIES AND RESTORED THE LEVEL OF PHOSPHO-AKT. TOGETHER, THESE DATA FOR THE FIRST TIME SUGGEST THAT LONG-TERM EXPOSURE TO ARSENIC CAN INCREASE THE RISK OF KIDNEY FIBROSIS. ADDITIONALLY, OUR DATA SUGGEST THAT THE ARSENIC-INDUCED FIBROTIC CHANGES ARE, AT LEAST IN PART, MEDIATED BY DNA METHYLATION AND THEREFORE POTENTIALLY CAN BE REVERSED BY EPIGENETIC THERAPEUTICS. 2019 6 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 7 141 35 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 8 6665 40 UPSTREAM AND DOWNSTREAM REGULATORS OF KLOTHO EXPRESSION IN CHRONIC KIDNEY DISEASE. KLOTHO IS A CRITICAL PROTEIN THAT PROTECTS THE KIDNEY. KLOTHO IS SEVERELY DOWNREGULATED IN CHRONIC KIDNEY DISEASE (CKD), AND ITS DEFICIENCY IS IMPLICATED IN THE PATHOGENESIS AND PROGRESSION OF CKD. CONVERSELY, AN INCREASE IN KLOTHO LEVELS RESULTS IN IMPROVED KIDNEY FUNCTION AND DELAYS CKD PROGRESSION, SUPPORTING THE NOTION THAT MODULATING KLOTHO LEVELS COULD REPRESENT A POSSIBLE THERAPEUTIC STRATEGY FOR CKD TREATMENT. NEVERTHELESS, THE REGULATORY MECHANISMS RESPONSIBLE FOR THE LOSS OF KLOTHO REMAIN ELUSIVE. PREVIOUS STUDIES HAVE DEMONSTRATED THAT OXIDATIVE STRESS, INFLAMMATION, AND EPIGENETIC MODIFICATIONS CAN MODULATE KLOTHO LEVELS. THESE MECHANISMS RESULT IN A DECREASE IN KLOTHO MRNA TRANSCRIPT LEVELS AND REDUCED TRANSLATION, THUS CAN BE GROUPED TOGETHER AS UPSTREAM REGULATORY MECHANISMS. HOWEVER, THERAPEUTIC STRATEGIES THAT AIM TO RESCUE KLOTHO LEVELS BY TARGETING THESE UPSTREAM MECHANISMS DO NOT ALWAYS RESULT IN INCREASED KLOTHO, INDICATING THE INVOLVEMENT OF OTHER REGULATORY MECHANISMS. EMERGING EVIDENCE HAS SHOWN THAT ENDOPLASMIC RETICULUM (ER) STRESS, THE UNFOLDED PROTEIN RESPONSE, AND ER-ASSOCIATED DEGRADATION ALSO AFFECT THE MODIFICATION, TRANSLOCATION, AND DEGRADATION OF KLOTHO, AND THUS ARE PROPOSED TO BE DOWNSTREAM REGULATORY MECHANISMS. HERE, WE DISCUSS THE CURRENT UNDERSTANDING OF UPSTREAM AND DOWNSTREAM REGULATORY MECHANISMS OF KLOTHO AND EXAMINE POTENTIAL THERAPEUTIC STRATEGIES TO UPREGULATE KLOTHO EXPRESSION FOR CKD TREATMENT. 2023 9 6431 37 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 10 3367 25 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 11 3795 38 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 12 1632 39 DNMTS ARE INVOLVED IN TGF-BETA1-INDUCED EPITHELIAL-MESENCHYMAL TRANSITIONS IN AIRWAY EPITHELIAL CELLS. CHRONIC RHINOSINUSITIS (CRS) PATHOGENESIS IS CLOSELY RELATED TO TISSUE REMODELING, INCLUDING EPITHELIAL-MESENCHYMAL TRANSITION (EMT). EPIGENETIC MECHANISMS PLAY KEY ROLES IN EMT. DNA METHYLATION, MEDIATED BY DNA METHYLTRANSFERASES (DNMTS), IS AN EPIGENETIC MARKER THAT IS CRITICAL TO EMT. THE GOAL OF THIS STUDY WAS TO DETERMINE WHETHER DNMTS WERE INVOLVED IN TGF-BETA1-INDUCED EMT AND ELUCIDATE THE UNDERLYING MECHANISMS IN NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION AND DNMT ACTIVITY WERE QUANTIFIED. DNMT EXPRESSION WAS MEASURED USING REAL-TIME PCR (QRT-PCR) IN HUMAN CRS TISSUES. MRNA AND PROTEIN LEVELS OF DNMTS, E-CADHERIN, VIMENTIN, ALPHA-SMA, AND FIBRONECTIN WERE DETERMINED USING RT-PCR AND WESTERN BLOTTING, RESPECTIVELY. DNMT1, DNMT3A, AND DNMT3B GENE EXPRESSION WERE KNOCKED DOWN USING SIRNA TRANSFECTION. MAPK PHOSPHORYLATION AND EMT-RELATED TRANSCRIPTION FACTOR LEVELS WERE DETERMINED USING WESTERN BLOTTING. SIGNALING PATHWAYS WERE ANALYZED USING SPECIFIC INHIBITORS OF MAPK. WE DEMONSTRATED THESE DATA IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. GLOBAL DNA METHYLATION, DNMT ACTIVITY, AND DNMT EXPRESSION INCREASED IN CRS TISSUES. DNMT EXPRESSION WAS POSITIVELY CORRELATED WITH LUND-MCKAY CT SCORES. TGF-BETA1 DOSE-DEPENDENTLY INDUCED DNMT EXPRESSION. FURTHER, 5-AZA INHIBITED TGF-BETA1-INDUCED DNMT, SNAIL, AND SLUG EXPRESSION RELATED TO EMT, AS WELL AS P38 AND JNK PHOSPHORYLATION IN A549 CELLS AND TGF-BETA1-INDUCED DNMT EXPRESSION AND EMT IN PRIMARY NASAL EPITHELIAL CELLS AND AIR-LIQUID INTERFACE CULTURES. TGF-BETA1-INDUCED DNMT EXPRESSION LEADS TO DNA METHYLATION AND EMT VIA P38, JNK, SNAIL, AND SLUG SIGNALING PATHWAYS. INHIBITION OF DNMT SUPPRESSED THE EMT PROCESS AND THEREFORE IS POTENTIALLY A CRS THERAPEUTIC STRATEGY. 2022 13 4563 32 MYELOID DNA METHYLTRANSFERASE3B DEFICIENCY AGGRAVATES PULMONARY FIBROSIS BY ENHANCING PROFIBROTIC MACROPHAGE ACTIVATION. BACKGROUND: IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC, PROGRESSIVE AND SEVERE DISEASE CHARACTERIZED BY EXCESSIVE MATRIX DEPOSITION IN THE LUNGS. MACROPHAGES PLAY CRUCIAL ROLES IN MAINTAINING LUNG HOMEOSTASIS BUT ARE ALSO CENTRAL IN THE PATHOGENESIS OF LUNG DISEASES LIKE PULMONARY FIBROSIS. ESPECIALLY, MACROPHAGE POLARIZATION/ACTIVATION SEEMS TO PLAY A CRUCIAL ROLE IN PATHOLOGY AND EPIGENETIC REPROGRAMING IS WELL-KNOWN TO REGULATE MACROPHAGE POLARIZATION. DNA METHYLATION ALTERATIONS IN IPF LUNGS HAVE BEEN WELL DOCUMENTED, BUT THE ROLE OF DNA METHYLATION IN SPECIFIC CELL TYPES, ESPECIALLY MACROPHAGES, IS POORLY DEFINED. METHODS: IN ORDER TO DETERMINE THE ROLE OF DNA METHYLATION IN MACROPHAGES DURING PULMONARY FIBROSIS, WE SUBJECTED MACROPHAGE SPECIFIC DNA METHYLTRANSFERASE (DNMT)3B, WHICH MEDIATES THE DE NOVO DNA METHYLATION, DEFICIENT MICE TO THE BLEOMYCIN-INDUCED PULMONARY FIBROSIS MODEL. MACROPHAGE POLARIZATION AND FIBROTIC PARAMETERS WERE EVALUATED AT 21 DAYS AFTER BLEOMYCIN ADMINISTRATION. DNMT3B KNOCKOUT AND WILD TYPE BONE MARROW-DERIVED MACROPHAGES WERE STIMULATED WITH EITHER INTERLEUKIN (IL)4 OR TRANSFORMING GROWTH FACTOR BETA 1 (TGFB1) IN VITRO, AFTER WHICH PROFIBROTIC GENE EXPRESSION AND DNA METHYLATION AT THE ARG1 PROMOTOR WERE DETERMINED. RESULTS: WE SHOW THAT DNMT3B DEFICIENCY PROMOTES ALTERNATIVE MACROPHAGE POLARIZATION INDUCED BY IL4 AND TGFB1 IN VITRO AND ALSO ENHANCES PROFIBROTIC MACROPHAGE POLARIZATION IN THE ALVEOLAR SPACE DURING PULMONARY FIBROSIS IN VIVO. MOREOVER, MYELOID SPECIFIC DELETION OF DNMT3B PROMOTED THE DEVELOPMENT OF EXPERIMENTAL PULMONARY FIBROSIS. CONCLUSIONS: IN SUMMARY, THESE DATA SUGGEST THAT MYELOID DNMT3B REPRESSES FIBROTIC MACROPHAGE POLARIZATION AND PROTECTS AGAINST BLEOMYCIN INDUCED PULMONARY FIBROSIS. 2022 14 1665 40 DOWNREGULATION OF KIDNEY PROTECTIVE FACTORS BY INFLAMMATION: ROLE OF TRANSCRIPTION FACTORS AND EPIGENETIC MECHANISMS. CHRONIC KIDNEY DISEASE (CKD) IS ASSOCIATED TO AN INCREASED RISK OF DEATH, CKD PROGRESSION, AND ACUTE KIDNEY INJURY (AKI) EVEN FROM EARLY STAGES, WHEN GLOMERULAR FILTRATION RATE (GFR) IS PRESERVED. THE LINK BETWEEN EARLY CKD AND THESE RISKS IS UNCLEAR, SINCE THERE IS NO ACCUMULATION OF UREMIC TOXINS. HOWEVER, PATHOLOGICAL ALBUMINURIA AND KIDNEY INFLAMMATION ARE FREQUENT FEATURES OF EARLY CKD, AND THE PRODUCTION OF KIDNEY PROTECTIVE FACTORS MAY BE DECREASED. INDEED, KLOTHO EXPRESSION IS ALREADY DECREASED IN CKD CATEGORY G1 (NORMAL GFR). KLOTHO HAS ANTI-AGING AND NEPHROPROTECTIVE PROPERTIES, AND DECREASED KLOTHO LEVELS MAY CONTRIBUTE TO INCREASE THE RISK OF DEATH, CKD PROGRESSION, AND AKI. IN THIS REVIEW, WE DISCUSS THE DOWNREGULATION BY MEDIATORS OF INFLAMMATION OF MOLECULES WITH SYSTEMIC AND/OR RENAL LOCAL PROTECTIVE FUNCTIONS, EXEMPLIFIED BY KLOTHO AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA COACTIVATOR-1ALPHA (PGC-1ALPHA), A TRANSCRIPTION FACTOR THAT PROMOTES MITOCHONDRIAL BIOGENESIS. CYTOKINES SUCH AS TWEAK, TNF-ALPHA, OR TRANSFORMING GROWTH FACTOR -BETA1 PRODUCED LOCALLY DURING KIDNEY INJURY OR RELEASED FROM INFLAMMATORY SITES AT OTHER ORGANS MAY DECREASE KIDNEY EXPRESSION OF KLOTHO AND PGC-1ALPHA OR LEAD TO SUBOPTIMAL RECRUITMENT OF THESE NEPHROPROTECTIVE PROTEINS. TRANSCRIPTION FACTORS (E.G., SMAD3 AND NF-KAPPAB) AND EPIGENETIC MECHANISMS (E.G., HISTONE ACETYLATION OR METHYLATION) CONTRIBUTE TO DOWNREGULATE THE EXPRESSION OF KLOTHO AND/OR PGC-1ALPHA, WHILE HISTONE CROTONYLATION PROMOTES PGC-1ALPHA EXPRESSION. NF-KAPPABIZ FACILITATES THE REPRESSIVE EFFECT OF NF-KAPPAB ON KLOTHO EXPRESSION. A DETAILED UNDERSTANDING OF THESE MEDIATORS MAY CONTRIBUTE TO THE DEVELOPMENT OF NOVEL THERAPEUTIC APPROACHES TO PREVENT CKD PROGRESSION AND ITS NEGATIVE IMPACT ON MORTALITY AND AKI. 2016 15 4702 34 NICOTINE-INDUCED OXIDATIVE STRESS CONTRIBUTES TO EMT AND STEMNESS DURING NEOPLASTIC TRANSFORMATION THROUGH EPIGENETIC MODIFICATIONS IN HUMAN KIDNEY EPITHELIAL CELLS. NICOTINE IS A COMPONENT OF CIGARETTE SMOKE AND MOUNTING EVIDENCE SUGGESTS TOXICITY AND CARCINOGENICITY OF TOBACCO SMOKE IN KIDNEY. CARCINOGENICITY OF NICOTINE ITSELF IN KIDNEY AND THE UNDERLYING MOLECULAR MECHANISMS ARE NOT WELL-UNDERSTOOD. HENCE, THE OBJECTIVE OF THIS STUDY WAS TO DETERMINE THE CARCINOGENIC EFFECTS OF CHRONIC NICOTINE EXPOSURE IN HK-2 HUMAN KIDNEY EPITHELIAL CELLS. THE EFFECTS OF NICOTINE EXPOSURE ON THE EXPRESSION OF GENES FOR CELLULAR REPROGRAMMING, REDOX STATUS, AND GROWTH SIGNALING PATHWAYS WERE ALSO EVALUATED TO UNDERSTAND THE MOLECULAR MECHANISMS. RESULTS REVEALED THAT CHRONIC EXPOSURE TO NICOTINE INDUCED GROWTH AND NEOPLASTIC TRANSFORMATION IN HK-2 CELLS. INCREASED LEVELS OF INTRACELLULAR REACTIVE OXYGEN SPECIES (ROS), ACQUIRED STEM CELL-LIKE SPHERE FORMATION, AND EPITHELIAL-MESENCHYMAL-TRANSITION (EMT) CHANGES WERE OBSERVED IN NICOTINE EXPOSED CELLS. TREATMENT WITH ANTIOXIDANT N-ACETYL CYSTEINE (NAC) RESULTED IN ABROGATION OF EMT AND STEMNESS IN HK-2 CELLS, INDICATING THE ROLE OF NICOTINE-INDUCED ROS IN THESE MORPHOLOGICAL CHANGES. THE RESULT ALSO SUGGESTS THAT ROS CONTROLS THE STEMNESS THROUGH REGULATION OF AKT PATHWAY DURING EARLY STAGES OF CARCINOGENESIS. ADDITIONALLY, THE EXPRESSION OF EPIGENETIC REGULATORY GENES WAS ALTERED IN NICOTINE-EXPOSED CELLS AND THE CHANGES WERE REVERSED BY NAC. THE EPIGENETIC THERAPEUTICS 5-AZA-2'-DEOXYCYTIDINE AND TRICHOSTATIN A ALSO ABROGATED THE STEMNESS. THIS SUGGESTS THE NICOTINE-INDUCED OXIDATIVE STRESS CAUSED EPIGENETIC ALTERATIONS CONTRIBUTING TO STEMNESS DURING NEOPLASTIC TRANSFORMATION. TO OUR KNOWLEDGE, THIS IS THE FIRST REPORT SHOWING THE ROS-MEDIATED EPIGENETIC MODIFICATIONS AS THE UNDERLYING MECHANISM FOR CARCINOGENICITY OF NICOTINE IN HUMAN KIDNEY EPITHELIAL CELLS. THIS STUDY FURTHER SUGGESTS THE POTENTIAL OF EPIGENETIC THERAPEUTICS FOR PHARMACOLOGICAL INTERVENTION IN NICOTINE-INDUCED KIDNEY CANCER. 2019 16 2001 26 EPIGENETIC AND NON-EPIGENETIC REGULATION OF KLOTHO IN KIDNEY DISEASE. KLOTHO IS A NOVEL RENOPROTECTIVE ANTI-AGING PROTEIN AVAILABLE IN MEMBRANE-BOUND OR SOLUBLE FORM. KLOTHO IS EXPRESSED IN BRAIN, PANCREAS, AND OTHER SOLID ORGANS BUT SHOWS HIGHEST EXPRESSION LEVELS IN THE KIDNEY. KLOTHO SUSTAINS NORMAL KIDNEY PHYSIOLOGY BUT KLOTHO REGULATION ALSO CONTRIBUTES TO THE PROGRESSION OF KIDNEY DISEASE. SYSTEMIC AND INTRARENAL LEVELS OF KLOTHO FALL DRASTICALLY DURING ACUTE KIDNEY INJURY, KIDNEY FIBROSIS, DIABETIC NEPHROPATHY, AND OTHER FORMS OF CHRONIC KIDNEY DISEASE, ETC. MOREOVER, EXOGENOUS SUPPLEMENTATION OR OVEREXPRESSION OF ENDOGENOUS KLOTHO ATTENUATES KIDNEY DISEASE. THE REGULATION OF ENDOGENOUS KLOTHO EXPRESSION INVOLVES EPIGENETIC AS WELL AS NON-EPIGENETIC MECHANISMS. THE EPIGENETIC MODIFICATIONS SUCH AS DNA METHYLATION, POST-TRANSLATIONAL HISTONE MODIFICATIONS, MIRNAS REGULATE THE CHANGE IN KLOTHO EXPRESSION IN KIDNEY DISEASE. NON-EPIGENETIC MECHANISMS SUCH AS ER STRESS, WNT SIGNALING, ACTIVATION OF THE RENIN ANGIOTENSIN SYSTEM (RAS), EXCESSIVE REACTIVE OXYGEN SPECIES AND CYTOKINE GENERATION, ALBUMIN OVERLOAD, AND PPAR-GAMMA SIGNALING ALSO CONTRIBUTE TO KLOTHO REGULATION. EVOLVING EVIDENCE HIGHLIGHT THE CAPACITY OF NATURAL PRODUCTS TO REGULATE KLOTHO EXPRESSION IN KIDNEY DISEASE. ALL THESE PRECLINICAL DATA SUGGEST THAT KLOTHO COULD BE A NOVEL BIOMARKER AS WELL AS THERAPEUTIC TARGET. HERE WE REVIEW THE DIFFERENT MECHANISMS OF KLOTHO REGULATION IN THE CONTEXT OF KLOTHO AS A BIOMARKER AND POTENTIAL THERAPEUTIC AGENT. 2021 17 3887 24 KLOTHO METHYLATION IS LINKED TO UREMIC TOXINS AND CHRONIC KIDNEY DISEASE. EPIGENETIC REGULATION PLAYS A MAJOR ROLE IN UREMIC TOXIN-INDUCED CHRONIC KIDNEY DISEASE (CKD) PROGRESSION. THE KLOTHO PROTEIN IS A KEY MODULATOR OF HOMEOSTASIS IN RENAL FUNCTION. UREMIC TOXIN ACCUMULATION CAN INDUCE DNA METHYLTRANSFERASE (DNMT) PROTEIN EXPRESSION, WHICH IS INVOLVED IN THE SILENCING OF KLOTHO THROUGH HYPERMETHYLATION. TREATMENT WITH DNMT INHIBITORS CAN INDUCE A HYPERMETHYLATED STATUS OF KLOTHO AND SUPPRESS MRNA AND PROTEIN EXPRESSION. EPIGENETIC TARGETING OF SPECIFIC GENES MAY BECOME AN EFFECTIVE STRATEGY TO PREVENT PROGRESSION OF UREMIA-RELATED CKD. 2012 18 6321 21 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 19 6235 55 THE M(6)A DEMETHYLASE FTO PROMOTES RENAL EPITHELIAL-MESENCHYMAL TRANSITION BY REDUCING THE M(6)A MODIFICATION OF LNCRNA GAS5. BACKGROUND: RENAL INTERSTITIAL FIBROSIS (RIF) IS THE MAIN PATHOLOGICAL CHANGE OF A VARIETY OF CHRONIC KIDNEY DISEASES (CKD). EPIGENETIC MODIFICATIONS OF FIBROSIS-PRONE GENES REGULATE RIF PROGRESSION. THIS STUDY AIMED TO INVESTIGATE LONG NON-CODING RNA (LNCRNA) N6-METHYLADENOSINE (M(6)A) MODIFICATION AND ITS ROLE IN REGULATING RIF PROGRESSION. METHODS: UNILATERAL URETERAL OCCLUSION (UUO) WAS EMPLOYED TO CONSTRUCT THE RIF IN VIVO MODEL; AND TGF-BETA1-TREATED HK-2 AND HKC-8 CELLS WERE USED FOR IN VITRO EXPERIMENTS. THE MRNA AND PROTEIN EXPRESSIONS WERE ASSESSED USING QRT-PCR AND WESTERN BLOT. THE PROLIFERATION AND MIGRATION WERE EVALUATED BY EDU ASSAY AND TRANSWELL ASSAY, RESPECTIVELY. IN ADDITION, LEVELS OF INFLAMMATORY CYTOKINES WERE DETERMINED BY ELISA ASSAY AND QRT-PCR. MOREOVER, LNCRNA GAS5 M(6)A LEVEL WAS DETECTED USING ME-RIP ASSAY. HE AND MASSON STAINING WERE EMPLOYED TO EVALUATE FIBROTIC LESIONS OF THE KIDNEY. RESULTS: FTO EXPRESSION WAS ELEVATED IN HK-2 AND HKC-8 CELLS AFTER TGF-BETA1 TREATMENT AND MOUSE KIDNEY TISSUE FOLLOWING UUO, AND LNCRNA GAS5 WAS DOWNREGULATED. LNCRNA GAS5 OVEREXPRESSION OR FTO SILENCING SUPPRESSED TGF-BETA1-INDUCED THE INCREASE OF EMT-RELATED PROTEINS (VIMENTIN, SNAIL AND N-CADHERIN) AND INFLAMMATORY CYTOKINES (IL-6, IL-1BETA AND TNF-ALPHA) LEVELS IN HK-2 CELLS. FTO SUPPRESSED LNCRNA GAS5 EXPRESSION BY REDUCING THE M6A MODIFICATION OF LNCRNA GAS5. ADDITIONALLY, FTO KNOCKDOWN COULD SUPPRESS EMT PROCESS AND INFLAMMATION RESPONSE INDUCED BY TGF-BETA1 AND UUO IN VITRO AND IN VIVO. AS EXPECTED, FTO KNOCKDOWN ABROGATED THE PROMOTION EFFECTS OF LNCRNA GAS5 SILENCING ON TGF-BETA1-INDUCED EMT PROCESS AND INFLAMMATION RESPONSE IN HK-2 AND HKC-8 CELLS. CONCLUSION: FTO PROMOTED EMT PROCESS AND INFLAMMATION RESPONSE THROUGH REDUCING THE M(6)A MODIFICATION OF LNCRNA GAS5. 2022 20 172 35 ABSENCE OF HDAC3 BY MATRIX STIFFNESS PROMOTES CHROMATIN REMODELING AND FIBROBLAST ACTIVATION IN IDIOPATHIC PULMONARY FIBROSIS. IDIOPATHIC PULMONARY FIBROSIS (IPF) IS A CHRONIC AND FATAL DISEASE CHARACTERIZED BY PROGRESSIVE AND IRREVERSIBLE LUNG SCARRING ASSOCIATED WITH PERSISTENT ACTIVATION OF FIBROBLASTS. EPIGENETICS COULD INTEGRATE DIVERSE MICROENVIRONMENTAL SIGNALS, SUCH AS STIFFNESS, TO DIRECT PERSISTENT FIBROBLAST ACTIVATION. HISTONE MODIFICATIONS BY DEACETYLASES (HDAC) MAY PLAY AN ESSENTIAL ROLE IN THE GENE EXPRESSION CHANGES INVOLVED IN THE PATHOLOGICAL REMODELING OF THE LUNG. PARTICULARLY, HDAC3 IS CRUCIAL FOR MAINTAINING CHROMATIN AND REGULATING GENE EXPRESSION, BUT LITTLE IS KNOWN ABOUT ITS ROLE IN IPF. IN THE STUDY, CONTROL AND IPF-DERIVED FIBROBLASTS WERE USED TO DETERMINE THE INFLUENCE OF HDAC3 ON CHROMATIN REMODELING AND GENE EXPRESSION ASSOCIATED WITH IPF SIGNATURE. ADDITIONALLY, THE CELLS WERE GROWN ON HYDROGELS TO MIMIC THE STIFFNESS OF A FIBROTIC LUNG. OUR RESULTS SHOWED A DECREASED HDAC3 IN THE NUCLEUS OF IPF FIBROBLASTS, WHICH CORRELATES WITH CHANGES IN NUCLEUS SIZE AND HETEROCHROMATIN LOSS. THE INHIBITION OF HDAC3 WITH A PHARMACOLOGICAL INHIBITOR CAUSES HYPERACETYLATION OF H3K9 AND PROVOKES AN INCREASED EXPRESSION OF COL1A1, ACTA2, AND P21. COMPARABLE RESULTS WERE FOUND IN HYDROGELS, WHERE MATRIX STIFFNESS PROMOTES THE LOSS OF NUCLEAR HDAC3 AND INCREASES THE PROFIBROTIC SIGNATURE. FINALLY, LATRUNCULIN B WAS USED TO CONFIRM THAT CHANGES BY STIFFNESS DEPEND ON THE MECHANOTRANSDUCTION SIGNALS. TOGETHER, THESE RESULTS SUGGEST THAT HDAC3 COULD BE A LINK BETWEEN EPIGENETIC MECHANISMS AND THE FIBROTIC MICROENVIRONMENT. 2023