1 5994 145 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 2 3036 55 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 3 3889 70 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 4 766 46 CCL5 SUPPRESSES KLOTHO EXPRESSION VIA P-STAT3/DNA METHYLTRANSFERASE1-MEDIATED PROMOTER HYPERMETHYLATION. BACKGROUND: ENHANCED INFLAMMATION AND REDUCED KLOTHO ARE COMMON FEATURES IN CHRONIC KIDNEY DISEASE (CKD). INFLAMMATION INDUCES DNA HYPERMETHYLATION. THIS STUDY ASSESSED THE PERFORMANCE OF INFLAMMATORY MARKER C-C MOTIF CHEMOKINE 5 (CCL5) IN EPIGENETIC REGULATION OF KLOTHO EXPRESSION. METHODS: FIFTY CKD PATIENTS AND 25 MATCHED CONTROLS WERE ENROLLED, AND SERUM CCL5 LEVEL, SKLOTHO LEVEL, AND DNA METHYLATION WERE EVALUATED IN THESE SUBJECTS. A RENAL INTERSTITIAL FIBROSIS (RIF) MODEL WITH CKD WAS INDUCED IN MICE VIA UNILATERAL URETERAL OBSTRUCTION (UUO) IN VIVO AND HUMAN PROXIMAL TUBULAR EPITHELIAL (HK-2) CELLS TREATED WITH CCL5 IN VITRO. 5-AZA-2'-DEOXYCYTIDINE (5-AZA), A DNA METHYLTRANSFERASE INHIBITOR WAS GIVEN TO UUO MICE. HEMATOXYLIN AND EOSIN (HE) AND MASSON TRICHROME STAINING WERE ADOPTED TO EVALUATE RENAL PATHOLOGICAL CHANGES. METHYLATION-SPECIFIC PCR WAS PERFORMED TO ASSESS DNA METHYLATION OF KLOTHO PROMOTER IN THE PERIPHERAL BLOOD LEUCOCYTES (PBLS) FROM CKD PATIENTS AND OBSTRUCTIVE KIDNEY FROM UUO MICE. CCL5, KLOTHO, AND DNA METHYLTRANSFERASES (DNMTS) WERE DETERMINED BY ELISAS, IMMUNOFLUORESCENCE, OR WESTERN BLOTTING. HK-2 CELLS WERE EXPOSED TO CCL5 WITH OR WITHOUT 5-AZA AND STATTIC, A P-SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) INHIBITOR, AND EXPRESSIONS OF P-STAT3, DNMT1, AND KLOTHO WERE DETERMINED BY WESTERN BLOTTING. RESULTS: CCL5 UPREGULATION CONCOMITANT WITH KLOTHO DOWNREGULATION IN SERUM AND GLOBAL DNA METHYLATION IN PBLS WERE OBSERVED IN CKD SAMPLES. UUO CONTRIBUTED TO SEVERE RENAL INTERSTITIAL FIBROSIS AND ENHANCED EXPRESSIONS OF FIBROTIC MARKERS. MOREOVER, UUO INCREASED THE CCL5 LEVEL, INDUCED KLOTHO PROMOTER METHYLATION, SUPPRESSED KLOTHO LEVEL, ACTIVATED P-STAT3 SIGNALING, AND UPREGULATED DNMT1 LEVEL. A SIMILAR OBSERVATION WAS MADE IN HK-2 CELLS TREATED WITH CCL5. MORE IMPORTANTLY, 5-AZA INHIBITED UUO-INDUCED KLOTHO HYPERMETHYLATION, REVERSED KLOTHO, DOWNREGULATED P-STAT3 EXPRESSIONS, AND AMELIORATED RIF IN VIVO. THE CONSISTENT FINDINGS IN VITRO WERE ALSO OBTAINED IN HK-2 CELLS EXPOSED TO 5-AZA AND STATTIC. CONCLUSION: THE CCL5/P-STAT3/DNMT1 AXIS IS IMPLICATED IN EPIGENETIC REGULATION OF KLOTHO EXPRESSION IN CKD. THIS STUDY PROVIDES NOVEL THERAPEUTIC POSSIBILITIES FOR REVERSAL OF KLOTHO SUPPRESSION BY CKD. 2022 5 6298 44 THE PROTECTIVE EFFECT OF ZEBULARINE, AN INHIBITOR OF DNA METHYLTRANSFERASE, ON RENAL TUBULOINTERSTITIAL INFLAMMATION AND FIBROSIS. RENAL FIBROSIS, THE FINAL PATHWAY OF CHRONIC KIDNEY DISEASE, IS CAUSED BY GENETIC AND EPIGENETIC MECHANISMS. ALTHOUGH DNA METHYLATION HAS DRAWN ATTENTION AS A DEVELOPING MECHANISM OF RENAL FIBROSIS, ITS CONTRIBUTION TO RENAL FIBROSIS HAS NOT BEEN CLARIFIED. TO ADDRESS THIS ISSUE, THE EFFECT OF ZEBULARINE, A DNA METHYLTRANSFERASE INHIBITOR, ON RENAL INFLAMMATION AND FIBROSIS IN THE MURINE UNILATERAL URETERAL OBSTRUCTION (UUO) MODEL WAS ANALYZED. ZEBULARINE SIGNIFICANTLY ATTENUATED RENAL TUBULOINTERSTITIAL FIBROSIS AND INFLAMMATION. ZEBULARINE DECREASED TRICHROME, ALPHA-SMOOTH MUSCLE ACTIN, COLLAGEN IV, AND TRANSFORMING GROWTH FACTOR-BETA1 STAINING BY 56.2%. 21.3%, 30.3%, AND 29.9%, RESPECTIVELY, AT 3 DAYS, AND BY 54.6%, 41.9%, 45.9%, AND 61.7%, RESPECTIVELY, AT 7 DAYS AFTER UUO. ZEBULARINE DOWNREGULATED MRNA EXPRESSION LEVELS OF MATRIX METALLOPROTEINASE (MMP)-2, MMP-9, FIBRONECTIN, AND SNAIL1 BY 48.6%. 71.4%, 31.8%, AND 42.4%, RESPECTIVELY, AT 7 DAYS AFTER UUO. ZEBULARINE ALSO SUPPRESSED THE ACTIVATION OF NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) AND THE EXPRESSION OF PRO-INFLAMMATORY CYTOKINES, INCLUDING TUMOR NECROSIS FACTOR-ALPHA, INTERLEUKIN (IL)-1BETA, AND IL-6, BY 69.8%, 74.9%, AND 69.6%, RESPECTIVELY, IN OBSTRUCTED KIDNEYS. FURTHERMORE, INHIBITING DNA METHYLTRANSFERASE BUTTRESSED THE NUCLEAR EXPRESSION OF NUCLEAR FACTOR (ERYTHROID-DERIVED 2)-LIKE FACTOR 2, WHICH UPREGULATED DOWNSTREAM EFFECTORS SUCH AS CATALASE (1.838-FOLD INCREASE AT 7 DAYS, P < 0.01), SUPEROXIDE DISMUTASE 1 (1.494-FOLD INCREASE AT 7 DAYS, P < 0.05), AND NAD(P)H: QUINONE OXIDOREDUATE-1 (1.376-FOLD INCREASE AT 7 DAYS, P < 0.05) IN OBSTRUCTED KIDNEYS. COLLECTIVELY, THESE FINDINGS SUGGEST THAT INHIBITING DNA METHYLATION RESTORES THE DISRUPTED BALANCE BETWEEN PRO-INFLAMMATORY AND ANTI-INFLAMMATORY PATHWAYS TO ALLEVIATE RENAL INFLAMMATION AND FIBROSIS. THEREFORE, THESE RESULTS HIGHLIGHT THE POSSIBILITY OF DNA METHYLTRANSFERASES AS THERAPEUTIC TARGETS FOR TREATING RENAL INFLAMMATION AND FIBROSIS. 2022 6 4016 41 LOW-DOSE HYDRALAZINE PREVENTS FIBROSIS IN A MURINE MODEL OF ACUTE KIDNEY INJURY-TO-CHRONIC KIDNEY DISEASE PROGRESSION. ACUTE KIDNEY INJURY (AKI) AND PROGRESSIVE CHRONIC KIDNEY DISEASE (CKD) ARE INTRINSICALLY TIED SYNDROMES. IN THIS REGARD, THE ACUTELY INJURED KIDNEY OFTEN DOES NOT ACHIEVE ITS FULL REGENERATIVE CAPACITY AND AKI DIRECTLY TRANSITIONS INTO PROGRESSIVE CKD ASSOCIATED WITH TUBULOINTERSTITIAL FIBROSIS. UNDERLYING MECHANISMS OF SUCH AKI-TO-CKD PROGRESSION ARE STILL INCOMPLETELY UNDERSTOOD AND SPECIFIC THERAPEUTIC INTERVENTIONS ARE STILL ELUSIVE. BECAUSE EPIGENETIC MODIFICATIONS PLAY A ROLE IN MAINTAINING TISSUE FIBROSIS, WE USED A MURINE MODEL OF ISCHEMIA-REPERFUSION INJURY TO DETERMINE WHETHER ABERRANT PROMOTER METHYLATION OF RASAL1 CONTRIBUTES CAUSALLY TO THE SWITCH BETWEEN PHYSIOLOGICAL REGENERATION AND TUBULOINTERSTITIAL FIBROGENESIS, A HALLMARK OF AKI-TO-CKD PROGRESSION. IT IS KNOWN THAT THE ANTIHYPERTENSIVE DRUG HYDRALAZINE HAS DEMETHYLATING ACTIVITY, AND THAT ITS OPTIMUM DEMETHYLATING ACTIVITY OCCURS AT CONCENTRATIONS BELOW BLOOD PRESSURE-LOWERING DOSES. ADMINISTRATION OF LOW-DOSE HYDRALAZINE EFFECTIVELY INDUCED EXPRESSION OF HYDROXYLASE TET3, WHICH CATALYZED RASAL1 HYDROXYMETHYLATION AND SUBSEQUENT RASAL1 PROMOTER DEMETHYLATION. HYDRALAZINE-INDUCED CPG PROMOTER DEMETHYLATION SUBSEQUENTLY ATTENUATED RENAL FIBROSIS AND PRESERVED EXCRETORY RENAL FUNCTION INDEPENDENT OF ITS BLOOD PRESSURE-LOWERING EFFECTS. IN COMPARISON, RASAL1 DEMETHYLATION AND INHIBITION OF TUBULOINTERSTITIAL FIBROSIS WAS NOT DETECTED UPON ADMINISTRATION OF THE ANGIOTENSIN-CONVERTING ENZYME INHIBITOR RAMIPRIL IN THIS MODEL. THUS, RASAL1 PROMOTER METHYLATION AND SUBSEQUENT TRANSCRIPTIONAL RASAL1 SUPPRESSION PLAYS A CAUSAL ROLE IN AKI-TO-CKD PROGRESSION. 2017 7 594 30 BET PROTEIN INHIBITOR JQ1 MODULATES MITOCHONDRIAL DYSFUNCTION AND OXIDATIVE STRESS INDUCED BY CHRONIC KIDNEY DISEASE. AMONG THE MECHANISMS INVOLVED IN THE PROGRESSION OF KIDNEY DISEASE, MITOCHONDRIAL DYSFUNCTION HAS SPECIAL RELEVANCE. EPIGENETIC DRUGS SUCH AS INHIBITORS OF EXTRA-TERMINAL DOMAIN PROTEINS (IBET) HAVE SHOWN BENEFICIAL EFFECTS IN EXPERIMENTAL KIDNEY DISEASE, MAINLY BY INHIBITING PROLIFERATIVE AND INFLAMMATORY RESPONSES. THE IMPACT OF IBET ON MITOCHONDRIAL DAMAGE WAS EXPLORED IN IN VITRO STUDIES IN RENAL CELLS STIMULATED WITH TGF-BETA1 AND IN VIVO IN MURINE UNILATERAL URETERAL OBSTRUCTION (UUO) MODEL OF PROGRESSIVE KIDNEY DAMAGE. IN VITRO, JQ1 PRETREATMENT PREVENTED THE TGF-BETA1-INDUCED DOWNREGULATION OF COMPONENTS OF THE OXIDATIVE PHOSPHORYLATION CHAIN (OXPHOS), SUCH AS CYTOCHROME C AND CV-ATP5A IN HUMAN PROXIMAL TUBULAR CELLS. IN ADDITION, JQ1 ALSO PREVENTED THE ALTERED MITOCHONDRIAL DYNAMICS BY AVOIDING THE INCREASE IN THE DRP-1 FISSION FACTOR. IN UUO MODEL, RENAL GENE EXPRESSION LEVELS OF CYTOCHROME C AND CV-ATP5A AS WELL AS PROTEIN LEVELS OF CYTOCHROME C WERE REDUCED THESE CHANGES WERE PREVENTED BY JQ1 ADMINISTRATION. IN ADDITION, JQ1 DECREASED PROTEIN LEVELS OF THE DRP1 FISSION PROTEIN AND INCREASED THE OPA-1 FUSION PROTEIN, RESTORING MITOCHONDRIAL DYNAMICS. MITOCHONDRIA ALSO PARTICIPATE IN THE MAINTENANCE OF REDOX BALANCE. JQ1 RESTORED THE GENE EXPRESSION OF ANTIOXIDANT PROTEINS, SUCH AS CATALASE AND HEME OXYGENASE 1 IN TGF-BETA1-STIMULATED HUMAN PROXIMAL TUBULAR CELLS AND IN MURINE OBSTRUCTED KIDNEYS. INDEED, IN TUBULAR CELLS, JQ1 DECREASED ROS PRODUCTION INDUCED BY STIMULATION WITH TGF-BETA1, AS EVALUATED BY MITOSOXTM. IBETS, SUCH AS JQ1, IMPROVE MITOCHONDRIAL DYNAMICS, FUNCTIONALITY, AND OXIDATIVE STRESS IN KIDNEY DISEASE. 2023 8 4017 35 LOW-DOSE HYDRALAZINE REDUCES ALBUMINURIA AND GLOMERULOSCLEROSIS IN A MOUSE MODEL OF OBESITY-RELATED CHRONIC KIDNEY DISEASE. AIM: TO DETERMINE, USING A MOUSE MODEL OF OBESITY, WHETHER LOW-DOSE HYDRALAZINE PREVENTS OBESITY-RELATED CHRONIC KIDNEY DISEASE (CKD). METHODS: FROM 8 WEEKS OF AGE, MALE C57BL/6 MICE RECEIVED A HIGH-FAT DIET (HFD) OR CHOW, WITH OR WITHOUT LOW-DOSE HYDRALAZINE (25 MG/L) IN DRINKING WATER, FOR 24 WEEKS. BIOMETRIC AND METABOLIC VARIABLES, RENAL FUNCTION AND STRUCTURAL CHANGES, RENAL GLOBAL DNA METHYLATION, DNA METHYLATION PROFILE AND MARKERS OF RENAL FIBROSIS, INJURY, INFLAMMATION AND OXIDATIVE STRESS WERE ASSESSED. RESULTS: THE HFD-FED MICE DEVELOPED OBESITY, WITH GLUCOSE INTOLERANCE, HYPERINSULINAEMIA AND DYSLIPIDAEMIA. OBESITY INCREASED ALBUMINURIA AND GLOMERULOSCLEROSIS, WHICH WERE SIGNIFICANTLY AMELIORATED BY LOW-DOSE HYDRALAZINE IN THE ABSENCE OF A BLOOD PRESSURE-LOWERING EFFECT. OBESITY INCREASED RENAL GLOBAL DNA METHYLATION AND THIS WAS ATTENUATED BY LOW-DOSE HYDRALAZINE. HFD-INDUCED CHANGES IN METHYLATION OF INDIVIDUAL LOCI WERE ALSO SIGNIFICANTLY REVERSED BY LOW-DOSE HYDRALAZINE. OBESE MICE DEMONSTRATED INCREASED MARKERS OF KIDNEY FIBROSIS, INFLAMMATION AND OXIDATIVE STRESS, BUT THESE MARKERS WERE NOT SIGNIFICANTLY IMPROVED BY HYDRALAZINE. CONCLUSION: LOW-DOSE HYDRALAZINE AMELIORATED HFD-INDUCED ALBUMINURIA AND GLOMERULOSCLEROSIS, INDEPENDENT OF ALTERATIONS IN BIOMETRIC AND METABOLIC VARIABLES OR BLOOD PRESSURE REGULATION. ALTHOUGH THE PRECISE MECHANISM OF RENOPROTECTION IN OBESITY IS UNCLEAR, AN EPIGENETIC BASIS MAY BE IMPLICATED. THESE DATA SUPPORT REPURPOSING HYDRALAZINE AS A NOVEL THERAPY TO PREVENT CKD PROGRESSION IN OBESE PATIENTS. 2022 9 5363 24 RECENT ADVANCES IN DIABETIC KIDNEY DISEASES: FROM KIDNEY INJURY TO KIDNEY FIBROSIS. DIABETIC KIDNEY DISEASE (DKD) IS THE LEADING CAUSE OF CHRONIC KIDNEY DISEASE AND END-STAGE RENAL DISEASE. THE NATURAL HISTORY OF DKD INCLUDES GLOMERULAR HYPERFILTRATION, PROGRESSIVE ALBUMINURIA, DECLINING ESTIMATED GLOMERULAR FILTRATION RATE, AND, ULTIMATELY, KIDNEY FAILURE. IT IS KNOWN THAT DKD IS ASSOCIATED WITH METABOLIC CHANGES CAUSED BY HYPERGLYCEMIA, RESULTING IN GLOMERULAR HYPERTROPHY, GLOMERULOSCLEROSIS, AND TUBULOINTERSTITIAL INFLAMMATION AND FIBROSIS. HYPERGLYCEMIA IS ALSO KNOWN TO CAUSE PROGRAMMED EPIGENETIC MODIFICATION. HOWEVER, THE DETAILED MECHANISMS INVOLVED IN THE ONSET AND PROGRESSION OF DKD REMAIN ELUSIVE. IN THIS REVIEW, WE DISCUSS RECENT ADVANCES REGARDING THE PATHOGENIC MECHANISMS INVOLVED IN DKD. 2021 10 6235 42 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 11 1665 43 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 12 3388 40 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 13 3048 40 GENOME-WIDE ANALYSIS REVEALED THAT DZNEP REDUCES TUBULOINTERSTITIAL FIBROSIS VIA DOWN-REGULATION OF PRO-FIBROTIC GENES. TUBULOINTERSTITIAL FIBROSIS HAS BEEN RECENTLY REPORTED TO BE CAUSED BY THE COLLAPSE OF THE EPIGENETIC REGULATION OF KIDNEY DISEASES. WE EXAMINED WHETHER PHARMACOLOGICAL INHIBITION OF HISTONE MODIFICATION IS EFFECTIVE AGAINST RENAL FIBROSIS. DZNEP (3-DEAZANEPLANOCIN A) WAS ORIGINALLY DEVELOPED AS AN ANTI-CANCER DRUG TO INHIBIT THE REPRESSIVE HISTONE MARK, H3K27ME3. WE USED A MODEL OF CHRONIC TUBULOINTERSTITIAL FIBROSIS INDUCED BY UNILATERAL ISCHAEMIA/REPERFUSION AND ADMINISTERED DZNEP INTRAVENOUSLY TO THE MICE FOR 8 WEEKS. WE FOUND DZNEP CONTRIBUTES TO THE REDUCTION OF TUBULOINTERSTITIAL FIBROSIS. WE SELECTED ONLY TUBULAR CELLS FROM IN VIVO SAMPLES USING LASER-CAPTURE MICRODISSECTION BECAUSE EPIGENETIC REGULATION IS SPECIFIC TO THE CELL TYPES, AND WE FOCUSED ON THE CHANGES IN THE TUBULAR CELLS. WE PERFORMED A GENOME-WIDE ANALYSIS OF TUBULAR CELLS USING HIGH-THROUGHPUT SEQUENCING (RNA-SEQ) TO IDENTIFY NOVEL EPIGENETIC FACTORS ASSOCIATED WITH RENAL FIBROSIS. WE FOUND THAT PRO-FIBROTIC GENES SUCH AS COL3A1 (COLLAGEN TYPE 3A1) AND TIMP2 (TISSUE INHIBITOR OF METALLOPROTEINASE 2) WERE SUPPRESSED BY DZNEP IN VIVO. IN ADDITION, PRO-FIBROTIC GENES SUCH AS COL4A1 (COLLAGEN TYPE 4A1), TIMP2 AND MMP14 WERE DOWN-REGULATED BY DZNEP IN VITRO. IN CONCLUSION, WE FOUND THAT PHARMACOLOGICAL EPIGENETIC MODIFICATION BY DZNEP DECREASED THE EXPRESSION LEVELS OF FIBROGENIC GENES IN TUBULAR CELLS AND INHIBITED TUBULOINTERSTITIAL FIBROSIS. 2018 14 5504 72 RHEIN REVERSAL OF DNA HYPERMETHYLATION-ASSOCIATED KLOTHO SUPPRESSION AMELIORATES RENAL FIBROSIS IN MICE. RENAL FIBROSIS IS THE HALLMARK OF CHRONIC KIDNEY DISEASES (CKD) AND ITS DEVELOPMENT AND PROGRESSION ARE SIGNIFICANTLY AFFECTED BY EPIGENETIC MODIFICATIONS. RHEIN, A PLANT-DERIVED ANTHRAQUINONE, DISPLAYS STRONG ANTI-FIBROSIS PROPERTIES, BUT ITS PROTECTIVE MODE OF ACTION REMAINS INCOMPLETELY UNDERSTOOD. HERE WE EXPLORE THE MECHANISM OF RHEIN ANTI-RENAL FIBROSIS BY INVESTIGATING ITS REGULATION OF KLOTHO, A KNOWN RENAL ANTI-FIBROTIC PROTEIN WHOSE SUPPRESSION AFTER RENAL INJURY REPORTEDLY INVOLVES ABERRANT DNA METHYLATION. WE REPORT THAT RHEIN IS AN IMPRESSIVE UP-REGULATOR OF KLOTHO AND IT MARKEDLY REVERSED KLOTHO DOWN-REGULATION IN UNILATERAL URETERAL OCCLUSION-INDUCED FIBROTIC KIDNEY. FURTHER EXAMINATIONS REVEALED THAT KLOTHO LOSS IN FIBROTIC KIDNEY IS ASSOCIATED WITH KLOTHO PROMOTER HYPERMETHYLATION DUE TO ABERRANT METHYLTRANSFERASE 1 AND 3A EXPRESSIONS. HOWEVER, RHEIN SIGNIFICANTLY CORRECTED ALL THESE EPIGENETIC ALTERATIONS AND SUBSEQUENTLY ALLEVIATED PRO-FIBROTIC PROTEIN EXPRESSION AND RENAL FIBROSIS, WHEREAS KLOTHO KNOCKDOWN VIA RNA INTERFERENCES LARGELY ABROGATED THE ANTI-RENAL FIBROTIC EFFECTS OF RHEIN, SUGGESTING THAT RHEIN EPIGENETIC REVERSAL OF KLOTHO LOSS REPRESENTS A CRITICAL MODE OF ACTION THAT CONFERS RHEIN'S ANTI- RENAL FIBROTIC FUNCTIONS. ALTOGETHER OUR STUDIES UNCOVER A NOVEL HYPOMETHYLATING CHARACTER OF RHEIN IN PREVENTING KLOTHO LOSS AND RENAL FIBROSIS, AND DEMONSTRATE THE EFFICACY OF KLOTHO-TARGETED EPIGENETIC INTERVENTION IN POTENTIAL TREATMENT OF RENAL FIBROSIS-ASSOCIATED KIDNEY DISEASES. 2016 15 5442 31 RENIN-ANGIOTENSIN BLOCKADE RESETS PODOCYTE EPIGENOME THROUGH KRUPPEL-LIKE FACTOR 4 AND ATTENUATES PROTEINURIA. PROTEINURIA IS A CENTRAL COMPONENT OF CHRONIC KIDNEY DISEASE AND AN INDEPENDENT RISK FACTOR FOR CARDIOVASCULAR DISEASE. KIDNEY PODOCYTES HAVE AN ESSENTIAL ROLE AS A FILTRATION BARRIER AGAINST PROTEINURIA. KRUPPEL-LIKE FACTOR 4 (KLF4) IS EXPRESSED IN PODOCYTES AND DECREASED IN GLOMERULAR DISEASES LEADING TO METHYLATION OF THE NEPHRIN PROMOTER, DECREASED NEPHRIN EXPRESSION AND PROTEINURIA. TREATMENT WITH AN ANGIOTENSIN RECEPTOR BLOCKER (ARB) REDUCED METHYLATION OF THE NEPHRIN PROMOTER IN MURINE GLOMERULI OF AN ADRIAMYCIN NEPHROPATHY MODEL WITH RECOVERY OF KLF4 EXPRESSION AND A DECREASE IN ALBUMINURIA. IN PODOCYTE-SPECIFIC KLF4 KNOCKOUT MICE, THE EFFECT OF ARB ON ALBUMINURIA AND THE NEPHRIN PROMOTER METHYLATION WAS ATTENUATED. IN CULTURED HUMAN PODOCYTES, ANGIOTENSIN II REDUCED KLF4 EXPRESSION AND CAUSED METHYLATION OF THE NEPHRIN PROMOTER WITH DECREASED NEPHRIN EXPRESSION. IN PATIENTS, NEPHRIN PROMOTER METHYLATION WAS INCREASED IN PROTEINURIC KIDNEY DISEASES WITH DECREASED KLF4 AND NEPHRIN EXPRESSION. KLF4 EXPRESSION IN ARB-TREATED PATIENTS WAS HIGHER IN PATIENTS WITH THAN WITHOUT ARB TREATMENT. THUS, ANGIOTENSIN II CAN MODULATE EPIGENETIC REGULATION IN PODOCYTES AND ARB INHIBITS THESE ACTIONS IN PART VIA KLF4 IN PROTEINURIC KIDNEY DISEASES. THIS STUDY PROVIDES A NEW CONCEPT THAT RENIN-ANGIOTENSIN SYSTEM BLOCKADE CAN EXERT THERAPEUTIC EFFECTS THROUGH EPIGENETIC MODULATION OF THE KIDNEY GENE EXPRESSION. 2015 16 6702 42 VEGFA PROMOTER GENE HYPERMETHYLATION AT HIF1ALPHA BINDING SITE IS AN EARLY CONTRIBUTOR TO CKD PROGRESSION AFTER RENAL ISCHEMIA. CHRONIC HYPOXIA IS A MAJOR CONTRIBUTOR TO CHRONIC KIDNEY DISEASE (CKD) AFTER ACUTE KIDNEY INJURY (AKI). HOWEVER, THE TEMPORAL RELATION BETWEEN THE ACUTE INSULT AND MALADAPTIVE RENAL RESPONSE TO HYPOXIA REMAINS UNCLEAR. IN THIS STUDY, WE ANALYZED THE TIME-COURSE OF RENAL HEMODYNAMICS, OXIDATIVE STRESS, INFLAMMATION, AND FIBROSIS, AS WELL AS EPIGENETIC MODIFICATIONS, WITH FOCUS ON HIF1ALPHA/VEGF SIGNALING, IN THE AKI TO CKD TRANSITION. SHAM-OPERATED, RIGHT NEPHRECTOMY (UNX), AND UNX PLUS RENAL ISCHEMIA (IR + UNX) GROUPS OF RATS WERE INCLUDED AND STUDIED AT 1, 2, 3, OR 4 MONTHS. THE IR + UNX GROUP DEVELOPED CKD CHARACTERIZED BY PROGRESSIVE PROTEINURIA, RENAL DYSFUNCTION, TUBULAR PROLIFERATION, AND FIBROSIS. AT FIRST MONTH POST-ISCHEMIA, THERE WAS A TWOFOLD SIGNIFICANT INCREASE IN OXIDATIVE STRESS AND REDUCTION IN GLOBAL DNA METHYLATION THAT WAS MAINTAINED THROUGHOUT THE STUDY. HIF1ALPHA AND VEGFA EXPRESSION WERE DEPRESSED IN THE FIRST AND SECOND-MONTHS POST-ISCHEMIA, AND THEN HIF1ALPHA BUT NOT VEGFA EXPRESSION WAS RECOVERED. INTERESTINGLY, HYPERMETHYLATION OF THE VEGFA PROMOTER GENE AT THE HIF1ALPHA BINDING SITE WAS FOUND, SINCE EARLY STAGES OF THE CKD PROGRESSION. OUR FINDINGS SUGGEST THAT RENAL HYPOPERFUSION, INEFFICIENT HYPOXIC RESPONSE, INCREASED OXIDATIVE STRESS, DNA HYPOMETHYLATION, AND, VEGFA PROMOTER GENE HYPERMETHYLATION AT HIF1ALPHA BINDING SITE, ARE EARLY DETERMINANTS OF AKI-TO-CKD TRANSITION. 2021 17 4574 42 MYOCARDIN-RELATED TRANSCRIPTION FACTOR A EPIGENETICALLY REGULATES RENAL FIBROSIS IN DIABETIC NEPHROPATHY. DIABETIC NEPHROPATHY (DN) IS ONE OF THE MOST COMMON COMPLICATIONS ASSOCIATED WITH DIABETES AND CHARACTERIZED BY RENAL MICROVASCULAR INJURY ALONG WITH ACCELERATED SYNTHESIS OF EXTRACELLULAR MATRIX PROTEINS CAUSING TUBULOINTERSTITIAL FIBROSIS. PRODUCTION OF TYPE I COLLAGEN, THE MAJOR COMPONENT OF EXTRACELLULAR MATRIX, IS AUGMENTED DURING RENAL FIBROSIS AFTER CHRONIC EXPOSURE TO HYPERGLYCEMIA. HOWEVER, THE TRANSCRIPTIONAL MODULATOR RESPONSIBLE FOR THE EPIGENETIC MANIPULATION LEADING TO INDUCTION OF TYPE I COLLAGEN GENES IS NOT CLEARLY DEFINED. WE SHOW HERE THAT TUBULOINTERSTITIAL FIBROSIS AS A RESULT OF DN WAS DIMINISHED IN MYOCARDIN-RELATED TRANSCRIPTION FACTOR A (MRTF-A) -DEFICIENT MICE. IN CULTURED RENAL TUBULAR EPITHELIAL CELLS AND THE KIDNEYS OF MICE WITH DN, MRTF-A WAS INDUCED BY GLUCOSE AND SYNERGIZED WITH GLUCOSE TO ACTIVATE COLLAGEN TRANSCRIPTION. NOTABLY, MRTF-A SILENCING LED TO THE DISAPPEARANCE OF PROMINENT HISTONE MODIFICATIONS INDICATIVE OF TRANSCRIPTIONAL ACTIVATION, INCLUDING ACETYLATED HISTONE H3K18/K27 AND TRIMETHYLATED HISTONE H3K4. DETAILED ANALYSIS REVEALED THAT MRTF-A RECRUITED P300, A HISTONE ACETYLTRANSFERASE, AND WD REPEAT-CONTAINING PROTEIN 5 (WDR5), A KEY COMPONENT OF THE HISTONE H3K4 METHYLTRANSFERASE COMPLEX, TO THE COLLAGEN PROMOTERS AND ENGAGED THESE PROTEINS IN TRANSCRIPTIONAL ACTIVATION. ESTRADIOL SUPPRESSED COLLAGEN PRODUCTION BY DAMPENING THE EXPRESSION AND BINDING ACTIVITY OF MRTF-A AND INTERFERING WITH THE INTERACTION BETWEEN P300 AND WDR5 IN RENAL EPITHELIAL CELLS. THEREFORE, TARGETING THE MRTF-A-ASSOCIATED EPIGENETIC MACHINERY MIGHT YIELD INTERVENTIONAL STRATEGIES AGAINST DN-ASSOCIATED RENAL FIBROSIS. 2015 18 1536 31 DNA METHYLATION ENZYMES IN THE KIDNEYS OF MALE AND FEMALE BTBR OB/OB MICE. DIABETIC KIDNEY DISEASE (DKD) IS THE LEADING CAUSE OF THE END-STAGE RENAL DISEASE. RECENT STUDIES HAVE SHOWN THAT EPIGENETIC MODIFICATIONS CONTRIBUTE TO ALTERATIONS IN GENE EXPRESSION AND THE DEVELOPMENT OF DKD. THIS STUDY AIMED TO SHOW AN EXPRESSION PROFILE OF KEY DNA (DE)METHYLATION ENZYMES (DNMT, TET PROTEINS) AND THEIR DIFFERENCES BETWEEN SEXES UNDER OBESITY AND DIABETIC CONDITION. MALE AND FEMALE BLACK AND TAN BRACHYURY (BTBR) OB/OB MICE AND THEIR CORRESPONDING WILD-TYPE LITTERMATES (BTBR WT) WERE STUDIED UNTIL 16 WEEKS OF AGE. METABOLIC PARAMETERS, KIDNEY MORPHOPHYSIOLOGY AND THE EXPRESSION OF FIBROTIC MARKERS AND EPIGENETIC ENZYMES WERE STUDIED IN WHOLE KIDNEY TISSUE OR SPECIFICALLY IN THE GLOMERULUS. THE RESULTS SHOWED SEXUAL DIMORPHISM IN THE DEVELOPMENT OF METABOLIC DISEASE AND IN KIDNEY MORPHOPHYSIOLOGY. FEMALE MICE HAVE A DIFFERENT PROFILE OF DNMTS EXPRESSION IN BOTH WT AND OBESE/DIABETIC CONDITION. FURTHERMORE, METABOLIC CONDITION NEGATIVELY MODULATED THE GLOMERULAR EXPRESSION OF TET1 AND TET3 ONLY IN FEMALES. TO OUR KNOWLEDGE, THIS IS THE FIRST STUDY THAT SHOWS A KIDNEY PROFILE OF THE EXPRESSION OF KEY (DE)METHYLATION ENZYMES, DNMTS AND TETS, IN THE BTBR OB/OB EXPERIMENTAL MODEL OF DKD AND ITS ASSOCIATION WITH SEX. THE KNOWLEDGE OF THIS EPIGENETIC PROFILE MAY HELP FUTURE RESEARCH TO UNDERSTAND THE PATHOPHYSIOLOGY OF DKD IN MALES AND FEMALES. 2023 19 1675 40 DRP1-MEDIATED MITOCHONDRIAL FISSION PROMOTES RENAL FIBROBLAST ACTIVATION AND FIBROGENESIS. EXCESSIVE MITOCHONDRIAL FISSION ACTS AS A PRO-PROLIFERATIVE MARKER IN SOME CANCERS AND ORGAN FIBROSIS; ITS POTENTIAL ROLE IN RENAL FIBROBLAST ACTIVATION AND FIBROGENESIS HAS NEVER BEEN INVESTIGATED. HERE, WE SHOWED MORE PRONOUNCED FRAGMENTED MITOCHONDRIA IN FIBROTIC THAN IN NON-FIBROTIC RENAL FIBROBLAST IN HUMANS AND MICE. IN A MOUSE MODEL OF OBSTRUCTIVE NEPHROPATHY, PHOSPHORYLATION OF DRP1 AT SERINE 616 (P-DRP1S616) AND ACETYLATION OF H3K27(H3K27AC) WAS INCREASED IN FIBROTIC KIDNEYS; PHARMACOLOGICAL INHIBITION OF MITOCHONDRIAL FISSION BY MDIVI-1 SUBSTANTIALLY REDUCED H3K27AC LEVELS, FIBROBLASTS ACCUMULATION, AND INTERSTITIAL FIBROSIS. MOREOVER, MDIVI-1 TREATMENT WAS ABLE TO ATTENUATE THE ESTABLISHED RENAL FIBROSIS. IN CULTURED RENAL INTERSTITIAL FIBROBLASTS, TARGETING DRP1 USING PHARMACOLOGICAL INHIBITOR OR SIRNA SUPPRESSED TGF-BETA1-ELICITED CELL ACTIVATION AND PROLIFERATION, AS EVIDENCED BY INHIBITING EXPRESSION OF ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA) AND COLLAGEN I, AS WELL AS BY REDUCING DNA SYNTHESIS. IN CONTRAST, DRP1 DELETION ENHANCED CELL APOPTOSIS, ALONG WITH DECREASED MITOCHONDRIAL FRAGMENTATION, MTROS ELEVATION, AND GLYCOLYTIC SHIFT UPON TGF-BETA1 STIMULATION. IN DRP1 DELETION FIBROBLASTS, RE-EXPRESSION OF WILD-TYPE DRP1 RATHER THAN DRP1S616A MUTANT RESTORES THE REDUCTION OF TGF-BETA-INDUCED-DRP1 PHOSPHORYLATION, H3K27AC, AND CELL ACTIVATION. MOREOVER, TGF-BETA1 TREATMENT INCREASED THE ENRICHMENT OF H3K27AC AT THE PROMOTERS OF ALPHA-SMA AND PCNA, WHICH WAS REVERSED IN DRP1-KNOCKDOWN FIBROBLASTS CO-TRANSFECTED WITH EMPTY VECTOR OR DRP1S616A, BUT NOT WILD-TYPE DRP1. COLLECTIVELY, OUR RESULTS IMPLY THAT INHIBITING P-DRP1S616-MEDIATED MITOCHONDRIAL FISSION ATTENUATES FIBROBLAST ACTIVATION AND PROLIFERATION IN RENAL FIBROSIS THROUGH EPIGENETIC REGULATION OF FIBROSIS-RELATED GENES TRANSCRIPTION AND MAY SERVE AS A THERAPEUTIC TARGET FOR RETARDING PROGRESSION OF CHRONIC KIDNEY DISEASE. 2020 20 3655 41 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