1 3889 146 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 2 3655 29 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 3 5504 60 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 4 2001 29 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 5 5994 70 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 6 3887 23 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 7 766 43 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 8 6665 34 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 1665 35 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 10 3890 29 KLOTHO, PHOSPHATE AND INFLAMMATION/AGEING IN CHRONIC KIDNEY DISEASE. EVIDENCE IS EMERGING FOR THE INFLAMMATORY NATURE OF MANY AGEING-ASSOCIATED DISEASES, INCLUDING ATHEROSCLEROSIS, VASCULAR CALCIFICATION, DIABETES AND CHRONIC KIDNEY DISEASE (CKD), AMONG OTHERS. AGEING ITSELF RESULTS IN CHRONIC LOW-GRADE INFLAMMATION THAT PROMOTES END-ORGAN DAMAGE. INFLAMMATORY ORGAN DAMAGE, IN TURN, MAY CONTRIBUTE TO INFLAMMATION. RECENT RESEARCH HAS IDENTIFIED THE KIDNEY-SECRETED HORMONE KLOTHO AS A CENTRAL PLAYER AT THE AGEING-INFLAMMATION INTERFACE. THUS, SYSTEMIC OR LOCAL RENAL INFLAMMATION DECREASES KIDNEY KLOTHO EXPRESSION. KLOTHO DOWN-REGULATION MAY BE INDUCED BY SPECIFIC CYTOKINES SUCH AS TUMOUR NECROSIS FACTOR-ALPHA OR TWEAK THROUGH THE CANONICAL ACTIVATION OF THE INFLAMMATORY TRANSCRIPTION FACTOR NUCLEAR FACTOR KAPPA B (NFKAPPAB) AND, SPECIFICALLY RELA. IN ADDITION, INFLAMMATORY CYTOKINES LEAD TO THE EPIGENETIC INACTIVATION OF KLOTHO TRANSCRIPTION. KLOTHO ITSELF HAS ANTIOXIDANT AND ANTI-INFLAMMATORY PROPERTIES AND THE CANONICAL NFKAPPAB COMPONENT RELA IS ONE OF ITS TARGETS. KLOTHO IS A KEY REGULATOR OF PHOSPHATE BALANCE AND A ROLE OF PHOSPHATE IN AGEING HAS BEEN SHOWN. HOWEVER, THE POTENTIAL RELATIONSHIP BETWEEN PHOSPHATE AND INFLAMMATION REQUIRES FURTHER CLARIFICATION. A CORRECT UNDERSTANDING OF THESE INTERACTIONS MAY LEAD TO THE DESIGN OF NOVEL THERAPEUTIC APPROACHES TO CKD AND CKD-RELATED INFLAMMATORY AND AGEING FEATURES AS WELL AS TO INFLAMMATION/AGEING IN GENERAL. 2012 11 3295 30 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 12 3036 61 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 13 2230 38 EPIGENETIC MODIFICATIONS OF KLOTHO EXPRESSION IN KIDNEY DISEASES. DEVELOPMENTS OF MANY RENAL DISEASES ARE SUBSTANTIALLY INFLUENCED BY EPIGENETIC MODIFICATIONS OF NUMEROUS GENES, MAINLY MEDIATED BY DNA METHYLATIONS, HISTONE MODIFICATIONS, AND MICRORNA INTERFERENCE; HOWEVER, NOT ALL GENE MODIFICATIONS CAUSALLY AFFECT THE DISEASE ONSET OR PROGRESSION. KLOTHO IS A CRITICAL GENE WHOSE REPRESSIONS IN VARIOUS PATHOLOGICAL CONDITIONS REPORTEDLY INVOLVE EPIGENETIC REGULATORY MECHANISMS. KLOTHO IS ALMOST UNEXCEPTIONALLY REPRESSED EARLY AFTER ACUTE OR CHRONIC RENAL INJURIES AND ITS LEVELS INVERSELY CORRELATED WITH THE DISEASE PROGRESSION AND SEVERITY. MOREOVER, THE STRATEGIES OF KLOTHO DEREPRESSION VIA EPIGENETIC MODULATIONS BENEFICIALLY CHANGE THE PATHOLOGICAL COURSES BOTH IN VITRO AND IN VIVO. HENCE, KLOTHO IS NOT ONLY CONSIDERED A BIOMARKER OF THE RENAL DISEASE BUT ALSO A POTENTIAL OR EVEN AN IDEAL TARGET OF THERAPEUTIC EPIGENETIC INTERVENTION. HERE, WE SUMMARIZE AND DISCUSS STUDIES THAT INVESTIGATE THE KLOTHO REPRESSION AND INTERVENTION IN RENAL DISEASES FROM AN EPIGENETIC POINT OF VIEW. THESE INFORMATION MIGHT SHED NEW SIGHTS INTO THE EFFECTIVE THERAPEUTIC STRATEGIES TO PREVENT AND TREAT VARIOUS RENAL DISORDERS. 2021 14 3451 27 HYPERMETHYLATIONS OF RASAL1 AND KLOTHO IS ASSOCIATED WITH RENAL DYSFUNCTION IN A CHINESE POPULATION ENVIRONMENTALLY EXPOSED TO CADMIUM. EXPOSURE TO CADMIUM (CD) CAN AFFECT BOTH DNA METHYLATION AND RENAL FUNCTION, BUT THERE ARE FEW EXAMPLES OF THE ASSOCIATION BETWEEN EPIGENETIC MARKERS AND CD-INDUCED KIDNEY DAMAGE. IT HAS BEEN SUGGESTED THAT HYPERMETHYLATION OF THE GENES RASAL1 AND KLOTHO IS ASSOCIATED WITH RENAL FIBROGENESIS. TO INVESTIGATE WHETHER HYPERMETHYLATION OF RASAL1 AND KLOTHO IN PERIPHERAL BLOOD DNA CAN BE ASSOCIATED WITH CD EXPOSURE AND/OR CD-INDUCED RENAL DYSFUNCTION, THE DEGREES OF METHYLATION OF RASAL1 AND KLOTHO IN PERIPHERAL BLOOD DNA FROM 81 RESIDENTS IN CD-POLLUTED AND NON-POLLUTED AREAS WERE MEASURED USING BISULFATE-PCR-PYROSEQUENCING. CHANGES IN BLOOD CADMIUM (BCD), URINARY CADMIUM (UCD), AND KIDNEY PARAMETERS WERE MEASURED, AND THE GLOMERULAR FILTRATION RATE (EGFR) WAS ESTIMATED. THE LEVELS OF BCD AND UCD CORRELATED POSITIVELY WITH THE LEVELS OF DNA METHYLATION IN RASAL1 AND IN KLOTHO. THE MORE HEAVILY EXPOSED RESIDENTS (BCD, 4.23-13.22MUG/L; UCD, 8.65-32.90MUG/G CREATININE) EXHIBITED OBVIOUS RENAL DYSFUNCTION. NOTABLY, WHEN CD CONCENTRATION IN BLOOD AND URINE WAS ADJUSTED, THE INCREASED METHYLATION LEVEL IN RASAL1 WAS INVERSELY CORRELATED WITH EGFR (P<0.01) BUT THE RELATIONSHIP BETWEEN HYPERMETHYLATION OF KLOTHO AND EGFR WAS NOT STATISTICALLY SIGNIFICANT. THE METHYLATION OF RASAL1 INCREASED ALONG WITH THE INCREASED ABNORMAL PREVALENCE OF EGFR. OUR FINDINGS SUGGEST THAT CD EXPOSURE CAN INDUCE THE HYPERMETHYLATION OF RASAL1 AND KLOTHO. HYPERMETHYLATION OF RASAL1 MAY BE AN INDICATOR OF THE PROGRESS FOR CHRONIC KIDNEY DISEASE. 2013 15 3654 30 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 16 5363 21 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 17 307 35 ALBUMINURIA DOWNREGULATION OF THE ANTI-AGING FACTOR KLOTHO: THE MISSING LINK POTENTIALLY EXPLAINING THE ASSOCIATION OF PATHOLOGICAL ALBUMINURIA WITH PREMATURE DEATH. TEN PERCENT OF THE ADULT POPULATION HAS CHRONIC KIDNEY DISEASE (CKD), WHICH IS DIAGNOSED WHEN THE GLOMERULAR FILTRATION RATE (GFR) IS BELOW 60 ML/MIN PER 1.73 M(2) OR WHEN ALBUMINURIA IS ABOVE 30 MG/DAY. THE NUMERICAL THRESHOLDS WERE CHOSEN BECAUSE THEY ARE ASSOCIATED WITH AN INCREASED RISK OF CKD PROGRESSION OR PREMATURE DEATH WITHIN A WIDER SCENARIO OF ACCELERATED AGING. INDEED, CKD IS ONE OF THE FASTEST GROWING CAUSES OF DEATH WORLDWIDE. A DECREASED GFR IS ASSOCIATED WITH THE ACCUMULATION OF URAEMIC TOXINS THAT MAY PROMOTE TISSUE AND ORGAN DAMAGE. HOWEVER, CKD MAY BE DIAGNOSED WHEN THE GFR IS COMPLETELY NORMAL, AS LONG AS THERE IS PATHOLOGICAL ALBUMINURIA. A KEY UNANSWERED QUESTION TO STEM THE RISE OF CKD-ASSOCIATED DEATHS IS WHETHER THE ASSOCIATION BETWEEN ISOLATED ALBUMINURIA (WHEN THE GFR IS NORMAL) AND PREMATURE DEATH IS CAUSAL. THE RECENT DEMONSTRATION THAT ALBUMINURIA PER SE DIRECTLY SUPPRESSES THE PRODUCTION OF THE ANTI-AGING FACTOR KLOTHO BY KIDNEY TUBULAR CELLS MAY BE ONE OF THE FIRST STEPS TO ADDRESS THE CAUSALITY OF THE ALBUMINURIA-PREMATURE DEATH-ACCELERATED AGING ASSOCIATION. THIS HYPOTHESIS SHOULD BE TESTED IN INTERVENTIONAL STUDIES THAT SHOULD DRAW FROM TRANSLATIONAL SCIENCE ADVANCES. THUS, THE OBSERVATION THAT ALBUMINURIA DECREASES KLOTHO PRODUCTION THROUGH EPIGENETIC MECHANISMS IMPLIES THAT KLOTHO DOWNREGULATION MAY PERSIST AFTER THE CORRECTION OF ALBUMINURIA, AND INNOVATIVE THERAPEUTIC APPROACHES ARE NEEDED TO RESTORE KLOTHO PRODUCTION. ON THE BASIS OF RECENT LITERATURE, THESE MAY INCLUDE MANIPULATION OF NF-KAPPAB REGULATORS SUCH AS B CELL LYMPHOMA 3 PROTEIN (BCL-3), AND EPIGENETIC REGULATORS SUCH AS HISTONE DEACETYLASES, OR THE REPURPOSING OF DRUGS SUCH AS PENTOXIFYLLINE. 2020 18 4605 32 NEGATIVE REGULATORS OF TGF-BETA1 SIGNALING IN RENAL FIBROSIS; PATHOLOGICAL MECHANISMS AND NOVEL THERAPEUTIC OPPORTUNITIES. ELEVATED EXPRESSION OF THE MULTIFUNCTIONAL CYTOKINE TRANSFORMING GROWTH FACTOR BETA1 (TGF-BETA1) IS CAUSATIVELY LINKED TO KIDNEY FIBROSIS PROGRESSION INITIATED BY DIABETIC, HYPERTENSIVE, OBSTRUCTIVE, ISCHEMIC AND TOXIN-INDUCED INJURY. THERAPEUTICALLY RELEVANT APPROACHES TO DIRECTLY TARGET THE TGF-BETA1 PATHWAY (E.G., NEUTRALIZING ANTIBODIES AGAINST TGF-BETA1), HOWEVER, REMAIN ELUSIVE IN HUMANS. TGF-BETA1 SIGNALING IS SUBJECTED TO EXTENSIVE NEGATIVE CONTROL AT THE LEVEL OF TGF-BETA1 RECEPTOR, SMAD2/3 ACTIVATION, COMPLEX ASSEMBLY AND PROMOTER ENGAGEMENT DUE TO ITS CRITICAL ROLE IN TISSUE HOMEOSTASIS AND NUMEROUS PATHOLOGIES. PROGRESSIVE KIDNEY INJURY IS ACCOMPANIED BY THE DEREGULATION (LOSS OR GAIN OF EXPRESSION) OF SEVERAL NEGATIVE REGULATORS OF THE TGF-BETA1 SIGNALING CASCADE BY MECHANISMS INVOLVING PROTEIN AND MRNA STABILITY OR EPIGENETIC SILENCING, FURTHER AMPLIFYING TGF-BETA1/SMAD3 SIGNALING AND FIBROSIS. EXPRESSION OF BONE MORPHOGENETIC PROTEINS 6 AND 7 (BMP6/7), SMAD7, SLOAN-KETTERING INSTITUTE PROTO-ONCOGENE (SKI) AND SKI-RELATED NOVEL GENE (SNON), PHOSPHATE TENSIN HOMOLOG ON CHROMOSOME 10 (PTEN), PROTEIN PHOSPHATASE MAGNESIUM/MANGANESE DEPENDENT 1A (PPM1A) AND KLOTHO ARE DRAMATICALLY DECREASED IN VARIOUS NEPHROPATHIES IN ANIMALS AND HUMANS ALBEIT WITH DIFFERENT KINETICS WHILE THE EXPRESSION OF SMURF1/2 E3 LIGASES ARE INCREASED. SUCH DEREGULATIONS FREQUENTLY INITIATE MALADAPTIVE RENAL REPAIR INCLUDING RENAL EPITHELIAL CELL DEDIFFERENTIATION AND GROWTH ARREST, FIBROTIC FACTOR (CONNECTIVE TISSUE GROWTH FACTOR (CTGF/CCN2), PLASMINOGEN ACTIVATOR INHIBITOR TYPE-1 (PAI-1), TGF-BETA1) SYNTHESIS/SECRETION, FIBROPROLIFERATIVE RESPONSES AND INFLAMMATION. THIS REVIEW ADDRESSES HOW LOSS OF THESE NEGATIVE REGULATORS OF TGF-BETA1 PATHWAY EXACERBATES RENAL LESION FORMATION AND DISCUSSES THE THERAPEUTIC VALUE IN RESTORING THE EXPRESSION OF THESE MOLECULES IN AMELIORATING FIBROSIS, THUS, PRESENTING NOVEL APPROACHES TO SUPPRESS TGF-BETA1 HYPERACTIVATION DURING CHRONIC KIDNEY DISEASE (CKD) PROGRESSION. 2021 19 4016 38 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 20 5322 23 PULMONARY DISEASES AND AGEING. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND IDIOPATHIC PULMONARY FIBROSIS ARE REGARDED AS A DISEASES OF ACCELERATED LUNG AGEING AND SHOW ALL OF THE HALLMARKS OF AGEING, INCLUDING TELOMERE SHORTENING, CELLULAR SENESCENCE, ACTIVATION OF PI3 KINASE-MTOR SIGNALING, IMPAIRED AUTOPHAGY, MITOCHONDRIAL DYSFUNCTION, STEM CELL EXHAUSTION, EPIGENETIC CHANGES, ABNORMAL MICRORNA PROFILES, IMMUNOSENESCENCE AND A LOW GRADE CHRONIC INFLAMMATION DUE TO SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP). MANY OF THESE AGEING MECHANISMS ARE DRIVEN BY EXOGENOUS AND ENDOGENOUS OXIDATIVE STRESS. THERE IS ALSO A REDUCTION IN ANTI-AGEING MOLECULES, SUCH AS SIRTUINS AND KLOTHO, WHICH FURTHER ACCELERATE THE AGEING PROCESS. UNDERSTANDING THESE MOLECULAR MECHANISMS HAS IDENTIFIED SEVERAL NOVEL THERAPEUTIC TARGETS AND SEVERAL DRUGS AND DIETARY INTERVENTIONS ARE NOW IN DEVELOPMENT TO TREAT CHRONIC LUNG DISEASE. 2019