1 5403 128 REGENERATION AFTER ACUTE KIDNEY INJURY REQUIRES PTIP-MEDIATED EPIGENETIC MODIFICATIONS. A TERMINALLY DIFFERENTIATED CELLULAR PHENOTYPE IS THOUGHT TO BE MAINTAINED, AT LEAST IN PART, BY BOTH ACTIVE AND REPRESSIVE HISTONE MARKS. HOWEVER, IT IS UNCLEAR WHETHER REGENERATING CELLS AFTER INJURY NEED TO REPLICATE SUCH EPIGENETIC MARKS TO RECOVER. TO TEST WHETHER RENAL EPITHELIAL CELL REGENERATION IS DEPENDENT ON HISTONE H3K4 METHYLATION, WE GENERATED A MOUSE MODEL THAT DELETED THE PAXIP1 GENE IN MATURE RENAL PROXIMAL TUBULES. PAXIP1 ENCODES PTIP, AN ESSENTIAL PROTEIN IN THE MLL3/4 HISTONE H3K4 METHYLTRANSFERASE COMPLEX. MICE WITH PTIP DELETIONS IN THE ADULT KIDNEY PROXIMAL TUBULES WERE VIABLE AND FERTILE. UPON ACUTE KIDNEY INJURY, SUCH MICE FAILED TO REGENERATE DAMAGED TUBULES, LEADING TO SCARRING AND INTERSTITIAL FIBROSIS. THE INABILITY TO REPAIR DAMAGE WAS LIKELY DUE TO A FAILURE TO REENTER MITOSIS AND REACTIVATE REGULATORY GENES SUCH AS SOX9. PTIP DELETION REDUCED HISTONE H3K4 METHYLATION IN UNINJURED ADULT KIDNEYS BUT DID NOT SIGNIFICANTLY AFFECT FUNCTION OR THE EXPRESSION OF EPITHELIAL SPECIFIC MARKERS. STRIKINGLY, CELL LINEAGE TRACING REVEALED THAT SURVIVING PTIP MUTANT CELLS COULD ALTER THEIR PHENOTYPE AND LOSE EPITHELIAL MARKERS. THESE DATA DEMONSTRATE THAT PTIP AND ASSOCIATED MLL3/4-MEDIATED HISTONE METHYLATION ARE NEEDED FOR REGENERATING PROXIMAL TUBULES AND TO MAINTAIN OR REESTABLISH THE CELLULAR EPITHELIAL PHENOTYPE. 2020 2 3644 27 INCREASED LEVELS OF ENDOGENOUS RETROVIRUSES TRIGGER FIBROINFLAMMATION AND PLAY A ROLE IN KIDNEY DISEASE DEVELOPMENT. INFLAMMATION IS A COMMON FEATURE OF ALL FORMS OF CHRONIC KIDNEY DISEASE; HOWEVER, THE UNDERLYING MECHANISM REMAINS POORLY UNDERSTOOD. EVOLUTIONARILY INHERITED ENDOGENOUS RETROVIRUSES (ERVS) HAVE THE POTENTIAL TO TRIGGER AN IMMUNE REACTION. COMPREHENSIVE RNA-SEQUENCING OF CONTROL AND DISEASED KIDNEYS FROM HUMAN AND MOUSE DISEASE MODELS INDICATED HIGHER EXPRESSION OF TRANSPOSABLE ELEMENTS (TES) AND ERVS IN DISEASED KIDNEYS. LOSS OF CYTOSINE METHYLATION CAUSING EPIGENETIC DEREPRESSION LIKELY CONTRIBUTES TO AN INCREASE IN ERV LEVELS. GENETIC DELETION/PHARMACOLOGICAL INHIBITION OF DNA METHYLTRANSFERASE 1 (DNMT1) INDUCES ERV EXPRESSION. IN CULTURED KIDNEY TUBULE CELLS, ERVS ELICIT THE ACTIVATION OF CYTOSOLIC NUCLEOTIDE SENSORS SUCH AS RIG-I, MDA5, AND STING. ERVS EXPRESSIONS IN KIDNEY TUBULES TRIGGER RIG-I/STING, AND CYTOKINE EXPRESSION, AND CORRELATE WITH THE PRESENCE OF IMMUNE CELLS. GENETIC DELETION OF RIG-I OR STING OR TREATMENT WITH REVERSE TRANSCRIPTASE INHIBITOR AMELIORATES KIDNEY FIBROINFLAMMATION. OUR DATA INDICATE AN IMPORTANT ROLE OF EPIGENETIC DEREPRESSION-INDUCED ERV ACTIVATION TRIGGERING RENAL FIBROINFLAMMATION. 2023 3 1819 29 EFFECTS OF CHRONIC OCHRATOXIN A EXPOSURE ON P53 HETEROZYGOUS AND P53 HOMOZYGOUS MICE. EXPOSURE TO THE MYCOTOXIN OCHRATOXIN A (OTA) CAUSES NEPHROPATHY IN DOMESTIC ANIMALS AND RODENTS AND RENAL TUMORS IN RODENTS AND POULTRY. HUMANS ARE EXPOSED TO OTA BY CONSUMING FOODS MADE WITH CONTAMINATED CEREAL GRAINS AND OTHER COMMODITIES. MANAGEMENT OF HUMAN HEALTH RISKS DUE TO OTA EXPOSURE DEPENDS, IN PART, ON ESTABLISHING A MODE OF ACTION (MOA) FOR OTA CARCINOGENESIS. TO FURTHER INVESTIGATE OTA'S MOA, P53 HETEROZYGOUS (P53+/-) AND P53 HOMOZYGOUS (P53+/+) MICE WERE EXPOSED TO OTA IN DIET FOR 26 WEEKS. THE FORMER ARE SUSCEPTIBLE TO TUMORIGENESIS UPON CHRONIC EXPOSURE TO GENOTOXIC CARCINOGENS. OTA-INDUCED RENAL DAMAGE BUT NO TUMORS WERE OBSERVED IN EITHER STRAIN, INDICATING THAT P53 HETEROZYGOSITY CONFERRED LITTLE ADDITIONAL SENSITIVITY TO OTA. RENAL CHANGES INCLUDED DOSE-DEPENDENT INCREASES IN CELLULAR PROLIFERATION, APOPTOSIS, KARYOMEGALY, AND TUBULAR DEGENERATION IN PROXIMAL TUBULES, WHICH WERE CONSISTENT WITH OCHRATOXICOSIS. THE LOWEST OBSERVED EFFECT LEVEL FOR RENAL CHANGES IN P53+/- AND P53+/+ MICE WAS 200 MUG OTA/KG BW/DAY. BASED ON THE LACK OF TUMORS AND THE SEVERITY OF RENAL AND BODY WEIGHT CHANGES AT A MAXIMUM TOLERATED DOSE, THE RESULTS WERE INTERPRETED AS SUGGESTIVE OF A PRIMARILY NONGENOTOXIC (EPIGENETIC) MOA FOR OTA CARCINOGENESIS IN THIS MOUSE MODEL. 2015 4 5994 44 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 5 4821 27 OCHRATOXIN A: 13-WEEK ORAL TOXICITY AND CELL PROLIFERATION IN MALE F344/N RATS. OCHRATOXIN A (OTA) IS NEPHROTOXIC AND A POTENT RENAL CARCINOGEN. MALE RATS ARE MOST SUSCEPTIBLE TO OTA TOXICITY, AND CHRONIC ADMINISTRATION OF OTA (70 AND 210 MICROG/KG BW) FOR 2 YEARS HAS BEEN SHOWN TO INDUCE HIGH INCIDENCES OF ADENOMAS AND CARCINOMAS ARISING FROM THE STRAIGHT SEGMENT OF THE PROXIMAL TUBULE EPITHELIUM. IN CONTRAST, TREATMENT WITH A LOWER DOSE OF 21 MICROG/KG BW DID NOT RESULT IN INCREASED TUMOR RATES, SUGGESTING A NONLINEAR DOSE RESPONSE FOR RENAL TUMOR FORMATION BY OTA. SINCE THE MECHANISM OF OTA CARCINOGENICITY IS STILL LARGELY UNKNOWN, THIS STUDY WAS CONDUCTED TO INVESTIGATE EARLY FUNCTIONAL AND PATHOLOGICAL EFFECTS OF OTA AND TO DETERMINE IF SUSTAINED STIMULATION OF RENAL CELL PROLIFERATION PLAYS A ROLE. MALE F344/N RATS WERE TREATED WITH OTA FOR UP TO 13 WEEKS UNDER CONDITIONS OF THE NATIONAL TOXICOLOGY PROGRAM (NTP) BIOASSAY. CELL PROLIFERATION IN THE RENAL CORTEX AND OUTER STRIPE OF THE OUTER MEDULLA (OSOM) WAS DETERMINED USING BROMODEOXYURIDINE INCORPORATION AND IMMUNOHISTOCHEMISTRY. HISTOPATHOLOGICAL EXAMINATION SHOWED RENAL ALTERATIONS IN MID- AND HIGH-DOSE-TREATED ANIMALS INVOLVING SINGLE-CELL DEATH AND PROMINENT NUCLEAR ENLARGEMENT WITHIN THE STRAIGHT PROXIMAL TUBULES. TREATMENT WITH OTA AT DOSES OF 70 AND 210 MICROG/KG BW LED TO A MARKED DOSE- AND TIME-DEPENDENT INCREASE IN RENAL CELL PROLIFERATION, EXTENDING FROM THE MEDULLARY RAYS INTO THE OSOM. NO EFFECTS WERE EVIDENT IN KIDNEYS OF LOW-DOSE-TREATED ANIMALS OR IN THE LIVER, WHICH IS NOT A TARGET FOR OTA CARCINOGENICITY. A NO OBSERVED EFFECT LEVEL IN THIS STUDY WAS ESTABLISHED AT 21 MICROG/KG BW, CORRELATING WITH THE DOSE IN THE NTP 2-YEAR BIOASSAY THAT DID NOT PRODUCE RENAL TUMORS. THE APPARENT CORRELATION BETWEEN ENHANCED CELL TURNOVER AND TUMOR FORMATION INDUCED BY OTA INDICATES THAT STIMULATION OF CELL PROLIFERATION MAY PLAY AN IMPORTANT ROLE IN OTA CARCINOGENICITY AND PROVIDES FURTHER EVIDENCE FOR AN EPIGENETIC, THRESHOLDED MECHANISM. 2007 6 4513 23 MULTI-OMIC APPROACHES TO ACUTE KIDNEY INJURY AND REPAIR. THE KIDNEY HAS A REMARKABLE REGENERATIVE CAPACITY. IN RESPONSE TO ISCHEMIC OR TOXIC INJURY, PROXIMAL TUBULE CELLS CAN PROLIFERATE TO REBUILD DAMAGED TUBULES AND RESTORE KIDNEY FUNCTION. HOWEVER, SEVERE ACUTE KIDNEY INJURY (AKI) OR RECURRENT AKI EVENTS CAN LEAD TO MALADAPTIVE REPAIR AND DISEASE PROGRESSION FROM AKI TO CHRONIC KIDNEY DISEASE (CKD). THE APPLICATION OF SINGLE CELL TECHNOLOGIES HAS IDENTIFIED INJURED PROXIMAL TUBULE CELL STATES WEEKS AFTER AKI, DISTINGUISHED BY A PRO-INFLAMMATORY SENESCENT MOLECULAR SIGNATURE. EPIGENETIC STUDIES HIGHLIGHTED DYNAMIC CHANGES IN THE CHROMATIN LANDSCAPE OF THE KIDNEY FOLLOWING AKI AND DESCRIBED KEY TRANSCRIPTION FACTORS LINKED TO THE AKI RESPONSE. THE INTEGRATION OF MULTI-OMIC TECHNOLOGIES OPENS NEW POSSIBILITIES TO IMPROVE OUR UNDERSTANDING OF AKI AND THE DRIVING FORCES BEHIND THE AKI-TO-CKD TRANSITION, WITH THE ULTIMATE GOAL OF DESIGNING TAILORED DIAGNOSTIC AND THERAPEUTIC STRATEGIES TO IMPROVE AKI OUTCOMES AND PREVENT KIDNEY DISEASE PROGRESSION. 2021 7 4000 37 LOSS OF HISTONE H3 K79 METHYLTRANSFERASE DOT1L FACILITATES KIDNEY FIBROSIS BY UPREGULATING ENDOTHELIN 1 THROUGH HISTONE DEACETYLASE 2. BACKGROUND: THE PROGRESSION RATE OF CKD VARIES SUBSTANTIALLY AMONG PATIENTS. THE GENETIC AND EPIGENETIC CONTRIBUTIONS THAT MODIFY HOW INDIVIDUAL PATIENTS RESPOND TO KIDNEY INJURY ARE LARGELY UNKNOWN. EMERGING EVIDENCE HAS SUGGESTED THAT HISTONE H3 K79 METHYLTRANSFERASE DOT1L HAS AN ANTIFIBROTIC EFFECT BY REPRESSING EDN1, WHICH ENCODES ENDOTHELIN 1 IN THE CONNECTING TUBULE/COLLECTING DUCT. METHODS: TO DETERMINE IF DELETION OF THE DOT1L GENE IS A GENETIC AND EPIGENETIC RISK FACTOR THROUGH REGULATING EDN1, WE STUDIED FOUR GROUPS OF MICE: WILD-TYPE MICE, CONNECTING TUBULE/COLLECTING DUCT-SPECIFIC DOT1L CONDITIONAL KNOCKOUT MICE (DOT1L(AC) ), DOT1L AND EDN1 DOUBLE-KNOCKOUT MICE (DE(AC) ), AND EDN1 CONNECTING TUBULE/COLLECTING DUCT-SPECIFIC CONDITIONAL KNOCKOUT MICE (EDN1(AC) ), UNDER THREE EXPERIMENTAL CONDITIONS (STREPTOZOTOCIN-INDUCED DIABETES, DURING NORMAL AGING, AND AFTER UNILATERAL URETERAL OBSTRUCTION). WE USED SEVERAL APPROACHES (COLOCALIZATION, GLUTATHIONE S-TRANSFERASE PULLDOWN, COIMMUNOPRECIPITATION, YEAST TWO-HYBRID, GEL SHIFT, AND CHROMATIN IMMUNOPRECIPITATION ASSAYS) TO IDENTIFY AND CONFIRM INTERACTION OF DOT1A (THE MAJOR DOT1L SPLICING VARIANT IN THE MOUSE KIDNEY) WITH HISTONE DEACETYLASE 2 (HDAC2), AS WELL AS THE FUNCTION OF THE DOT1A-HDAC2 COMPLEX IN REGULATING EDN1 TRANSCRIPTION. RESULTS: IN EACH CASE, DOT1L(AC) MICE DEVELOPED MORE PRONOUNCED KIDNEY FIBROSIS AND KIDNEY MALFUNCTION COMPARED WITH WILD-TYPE MICE. THESE DOT1L(AC) PHENOTYPES WERE AMELIORATED IN THE DOUBLE-KNOCKOUT DE(AC) MICE. THE INTERACTION BETWEEN DOT1A AND HDAC2 PREVENTS THE DOT1A-HDAC2 COMPLEX FROM ASSOCIATION WITH DNA, PROVIDING A COUNTERBALANCING MECHANISM GOVERNING EDN1 TRANSCRIPTION BY MODULATING H3 K79 DIMETHYLATION AND H3 ACETYLATION AT THE EDN1 PROMOTER. CONCLUSIONS: OUR STUDY CONFIRMS DOT1L TO BE A GENETIC AND EPIGENETIC MODIFIER OF KIDNEY FIBROSIS, REVEALS A NEW MECHANISM REGULATING EDN1 TRANSCRIPTION BY DOT1A AND HDAC2, AND REINFORCES ENDOTHELIN 1 AS A THERAPEUTIC TARGET OF KIDNEY FIBROSIS. 2020 8 766 31 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 9 4016 33 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 10 4362 33 MIR?152 REGULATES TGF?BETA1?INDUCED EPITHELIAL?MESENCHYMAL TRANSITION BY TARGETING HPIP IN TUBULAR EPITHELIAL CELLS. RENAL FIBROSIS IS A COMMON PATHOLOGICAL FEATURE OF CHRONIC KIDNEY DISEASES, AND THEIR DEVELOPMENT AND PROGRESSION ARE INFLUENCED BY EPIGENETIC MODIFICATIONS INCLUDING ABERRANT MICRORNA (MIRNA OR MIR) EXPRESSION. MIRNAS HAVE BEEN DEMONSTRATED TO MODULATE THE AGGRESSIVENESS OF VARIOUS CANCERS AND HAVE EMERGED AS POSSIBLE THERAPEUTIC AGENTS FOR THE MANAGEMENT OF RENAL FIBROSIS. TRANSFORMING GROWTH FACTOR BETA1 (TGF?BETA1)?INDUCED EPITHELIAL?MESENCHYMAL TRANSITION (EMT) OF TUBULAR EPITHELIAL CELLS SERVES A ROLE IN THE INITIATION AND PROGRESSION OF RENAL FIBROSIS. FURTHERMORE, RECENT RESULTS INDICATED THAT THE PROGRESSION OF EMT IS REVERSIBLE. THE PRESENT STUDY AIMED TO CLARIFY THE ROLE OF MIR?152 IN EMT OF THE TUBULAR EPITHELIAL CELL LINE HK?2, STIMULATED BY TGF?BETA1, USING IN VITRO TRANSFECTION WITH A MIR?152 MIMIC AND TO FURTHER INVESTIGATE THE UNDERLYING MECHANISM OF MIR?152 ACTIVITY. IN THE PRESENT STUDY, MIR?152 EXPRESSION WAS SIGNIFICANTLY REDUCED IN TGF?BETA1?TREATED HK?2 CELLS, ACCOMPANIED BY AN INCREASED EXPRESSION OF HEMATOPOIETIC PRE?B?CELL LEUKEMIA TRANSCRIPTION FACTOR (PBX)?INTERACTING PROTEIN (HPIP). ADDITIONALLY, MIR?152 OVEREXPRESSION INHIBITED TGF?BETA1?INDUCED EMT AND SUPPRESSED HPIP EXPRESSION BY DIRECTLY TARGETING THE 3' UNTRANSLATED REGION OF HPIP IN HK?2 CELLS. FURTHERMORE, UPREGULATION OF HPIP REVERSED MIR?152?MEDIATED INHIBITORY EFFECTS ON THE EMT. COLLECTIVELY, THE RESULTS SUGGEST THAT DOWNREGULATION OF MIR?152 INITIATES THE DEDIFFERENTIATION OF RENAL TUBULES AND PROGRESSION OF RENAL FIBROSIS, WHICH MAY PROVIDE IMPORTANT TARGETS FOR PREVENTION STRATEGIES OF RENAL FIBROSIS. 2018 11 3889 36 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 12 3036 42 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 2937 33 GENETIC AND EPIGENETIC ALTERATIONS DURING RENAL CARCINOGENESIS. RENAL CELL CARCINOMA (RCC) IS NOT A SINGLE ENTITY, BUT COMPRISES A GROUP OF TUMORS INCLUDING CLEAR CELL RCC, PAPILLARY RCC AND CHROMOPHOBE RCC, WHICH ARISE FROM THE EPITHELIUM OF RENAL TUBULES. THE MAJORITY OF CLEAR CELL RCCS, THE MAJOR HISTOLOGICAL SUBTYPE, HAVE GENETIC OR EPIGENETIC INACTIVATION OF THE VON HIPPEL-LINDAU (VHL) GENE. GERMLINE MUTATIONS IN THE MET AND FUMARATE HYDRATASE (FH) GENES LEAD TO THE DEVELOPMENT OF TYPE 1 AND TYPE 2 PAPILLARY RCCS, RESPECTIVELY, AND SUCH MUTATIONS OF EITHER THE TSC1 OR TSC2 GENE INCREASE THE RISK OF RCC. GENOME-WIDE COPY NUMBER ALTERATION ANALYSIS HAS SUGGESTED THAT LOSS OF CHROMOSOME 3P AND GAIN OF CHROMOSOMES 5Q AND 7 MAY BE COPY NUMBER ABERRATIONS INDISPENSABLE FOR THE DEVELOPMENT OF CLEAR CELL RCC. WHEN CHROMOSOME 1P, 4, 9, 13Q OR 14Q IS ALSO LOST, MORE CLINICOPATHOLOGICALLY AGGRESSIVE CLEAR CELL RCC MAY DEVELOP. SINCE RENAL CARCINOGENESIS IS ASSOCIATED WITH NEITHER CHRONIC INFLAMMATION NOR PERSISTENT VIRAL INFECTION, AND HARDLY ANY HISTOLOGICAL CHANGE IS EVIDENT IN CORRESPONDING NON-TUMOROUS RENAL TISSUE FROM PATIENTS WITH RENAL TUMORS, PRECANCEROUS CONDITIONS IN THE KIDNEY HAVE BEEN RARELY DESCRIBED. HOWEVER, REGIONAL DNA HYPERMETHYLATION ON C-TYPE CPG ISLANDS HAS ALREADY ACCUMULATED IN SUCH NON-CANCEROUS RENAL TISSUES, SUGGESTING THAT, FROM THE VIEWPOINT OF ALTERED DNA METHYLATION, THE PRESENCE OF PRECANCEROUS CONDITIONS CAN BE RECOGNIZED EVEN IN THE KIDNEY. GENOME-WIDE DNA METHYLATION PROFILES IN PRECANCEROUS CONDITIONS ARE BASICALLY INHERITED BY THE CORRESPONDING CLEAR CELL RCCS DEVELOPING IN INDIVIDUAL PATIENTS: DNA METHYLATION ALTERATIONS AT THE PRECANCEROUS STAGE MAY FURTHER PREDISPOSE RENAL TISSUE TO EPIGENETIC AND GENETIC ALTERATIONS, GENERATE MORE MALIGNANT CANCERS, AND EVEN DETERMINE PATIENT OUTCOME. THE LIST OF TUMOR-RELATED GENES SILENCED BY DNA HYPERMETHYLATION HAS RECENTLY BEEN INCREASING. GENETIC AND EPIGENETIC PROFILING PROVIDES AN OPTIMAL MEANS OF PROGNOSTICATION FOR PATIENTS WITH RCCS. RECENTLY DEVELOPED HIGH-THROUGHPUT TECHNOLOGIES FOR GENETIC AND EPIGENETIC ANALYSES WILL FURTHER ACCELERATE THE IDENTIFICATION OF KEY MOLECULES FOR USE IN THE PREVENTION, DIAGNOSIS AND THERAPY OF RCCS. 2010 14 1502 29 DNA METHYLATION AND EPIGENETIC EVENTS UNDERLYING RENAL CELL CARCINOMAS. RENAL CELL CARCINOMA (RCC) REFERS TO A GROUP OF TUMORS THAT DEVELOP FROM THE EPITHELIUM OF THE KIDNEY TUBES, INCLUDING CLEAR CELL RCC, PAPILLARY RCC, AND CHROMOPHOBE RCC. MOST CLEAR CELL RENAL CARCINOMAS HAVE A LARGE HISTOLOGIC SUBTYPE, GENETIC OR EPIGENETIC VON HIPPEL-LINDAU (VHL). A COMPREHENSIVE ANALYSIS OF THE GENETIC MODIFICATION GENOME SUGGESTED THAT CHROMOSOME 3P LOSS AND CHROMOSOME GAINS 5Q AND 7 MAY BE SIGNIFICANT COPY DEFECTS IN THE DEVELOPMENT OF CLEAR RCC. A MORE POTENT RCC MAY DEVELOP IF CHROMOSOME 1P, 4, 9, 13Q, OR 14Q IS ALSO LOST. RENAL CARCINOGENESIS IS NOT ASSOCIATED WITH CHRONIC INFLAMMATION OR HISTOLOGICAL CHANGES. HOWEVER, IF REGIONAL HYPERMETHYLATION OF DNA IN CPG C-TYPE ISLANDS HAS ALREADY ACCUMULATED IN CANCER-FREE KIDNEY TISSUE, IT IMPLIES THAT THE PRESENCE OF MALIGNANT KIDNEY LESIONS MAY ALSO BE DETECTED BY MODIFIED DNA METHYLATION. MODIFICATION OF DNA METHYLATION IN CANCEROUS KIDNEY TISSUE MAY ADVANCE KIDNEY TISSUE TO EPIGENETIC MUTATIONS AND GENES, LEADING TO MORE SERIOUS CANCERS AND EVEN DETERMINING A PATIENT'S OUTCOME. THE GENETIC AND EPIGENETIC PROFILE PROVIDES ACCURATE PREDICTORS FOR PATIENTS WITH KIDNEY CANCER. NEW GENETIC AND EPIGENETIC ANALYSIS TECHNOLOGIES WILL HELP TO SPEED UP THE IDENTIFICATION OF VITAL CELLS FOR KIDNEY CANCER PREVENTION, DIAGNOSIS, AND TREATMENT. 2022 15 6020 39 THE ATTENUATION OF RENAL FIBROSIS BY HISTONE DEACETYLASE INHIBITORS IS ASSOCIATED WITH THE PLASTICITY OF FOXP3(+)IL-17(+) T CELLS. BACKGROUND: THE HISTONE DEACETYLASE (HDAC) INHIBITOR, WHICH HAS POTENTIAL EFFECTS ON EPIGENETIC MODIFICATIONS, HAD BEEN REPORTED TO ATTENUATE RENAL FIBROSIS. CD4(+) FORKHEAD BOX P3 (FOXP3)(+) T REGULATORY (TREG) CELLS MAY BE CONVERTED TO INFLAMMATION-ASSOCIATED T HELPER 17 CELLS (TH17) WITH TISSUE FIBROSIS PROPERTIES. THE ASSOCIATION BETWEEN FOXP3(+)IL-17(+) T CELLS AND THE ATTENUATION OF RENAL FIBROSIS BY THE HDAC INHIBITOR IS NOT CLEAR. METHODS: THIS STUDY EVALUATED THE ROLES OF THE HDAC INHIBITOR, TREG CELLS AND THEIR DIFFERENTIATION INTO TH17 CELLS, WHICH AGGRAVATE CHRONIC INFLAMMATION AND RENAL FIBROSIS IN A UNILATERAL URETERAL OBSTRUCTION (UUO) MOUSE MODEL. THE STUDY GROUPS INCLUDED CONTROL AND UUO MICE THAT WERE MONITORED FOR 7, 14 OR 21 DAYS. RESULTS: JUXTAGLOMERULAR (JG) HYPERPLASIA, ANGIOTENSIN II TYPE 1 RECEPTOR (AT1R) EXPRESSION AND LYMPHOCYTE INFILTRATION WERE OBSERVED IN RENAL TISSUES AFTER UUO BUT WERE DECREASED AFTER TRICHOSTATIN A (TSA) TREATMENT, A HDAC INHIBITOR. THE NUMBER OF CD4(+)FOXP3(+) T CELLS INCREASED PROGRESSIVELY, ALONG WITH THE NUMBER OF FOXP3(+)INTERLEUKIN (IL)-17(+) T CELLS, AFTER 14 DAYS, AND THEIR NUMBERS THEN PROGRESSIVELY DECREASED WITH INCREASING CD4(+)IL-17(+) T CELL NUMBERS, AS DEMONSTRATED BY DOUBLE IMMUNOHISTOCHEMISTRY. PROGRESSIVE RENAL FIBROSIS WAS ASSOCIATED WITH THE LOSS OF CD4(+)FOXP3(+)IL-17(+) T CELLS IN SPLENIC SINGLE-CELL SUSPENSIONS. FOXP3(+)IL-17(+) T CELLS EXPRESSED TGF-BETA1 BOTH IN VITRO AND IN VIVO, AND TGF-BETA1 EXPRESSION WAS SIGNIFICANTLY KNOCKDOWN BY IL-17 SIRNA IN VITRO. THESE CELLS WERE FOUND TO PLAY A ROLE IN CONVERTING TREGS INTO IL-17- AND TGF-BETA1-PRODUCING CELLS. CONCLUSIONS: TSA TREATMENT DECREASED JG HYPERPLASIA, THE PERCENTAGE OF FOXP3(+)IL-17(+) CELLS AND THE DEGREE OF FIBROSIS, SUGGESTING THAT THERAPEUTIC BENEFITS MAY RESULT FROM EPIGENETIC MODIFICATIONS. 2017 16 861 31 CHROMATIN REMODELING FACTOR, INO80, INHIBITS PMAIP1 IN RENAL TUBULAR CELLS VIA EXCHANGE OF HISTONE VARIANT H2A.Z. FOR H2A. EPIGENETIC MODIFICATIONS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS, AND CHROMATIN STRUCTURES IN THE KIDNEY CONTRIBUTE TOWARDS THE PROGRESSION OF CHRONIC KIDNEY DISEASE (CKD). IN THIS STUDY, THE ROLE OF CHROMATIN REMODELING FACTOR INOSITOL REQUIRING 80 (INO80) WAS INVESTIGATED. ALTHOUGH INO80 REGULATES TRANSCRIPTION BY ALTERING THE CHROMATIN STRUCTURE AT THE NUCLEOSOME LEVEL, ITS ROLE IN THE KIDNEY REMAINS UNKNOWN. WE DEMONSTRATED THAT THE EXPRESSION OF INO80 IN IMPAIRED KIDNEYS DECREASED IN RATS WITH UNILATERAL URETHRAL OBSTRUCTION. WE INVESTIGATED INO80 EXPRESSION IN A PROXIMAL TUBULAR CELL LINE AND OBSERVED THAT ITS EXPRESSION DECREASED UNDER HYPOXIC CONDITION. ADDITIONALLY, INO80 KNOCKDOWN PROMOTED APOPTOSIS, SUGGESTING THAT INO80 PLAYS A ROLE IN INHIBITING TUBULAR CELL APOPTOSIS. WE IDENTIFIED DOWNSTREAM TARGET GENES OF INO80 VIA GENOME-WIDE ANALYSIS USING RNA-SEQUENCES AND FOUND THAT THE EXPRESSION OF APOPTOSIS-RELATED GENES, SUCH AS TP53 AND E2F1, AND PRO-APOPTOTIC GENES, SUCH AS PMAIP1, INCREASED UPON INO80 KNOCKDOWN. CHIP-QPCR OF THE LOCI OF PMAIP1 SHOWED THAT THE AMOUNT OF H2A.Z. INCREASED INSTEAD OF DECREASING THE AMOUNT OF H2A WHEN INO80 WAS KNOCKED DOWN. THESE RESULTS INDICATED THAT INO80 PLAYS A ROLE IN THE EXCHANGE OF H2A.Z. FOR H2A IN THE PROMOTER REGION OF PMAIP1 IN TUBULAR CELLS TO INHIBIT APOPTOSIS DURING CKD PROGRESSION. 2023 17 3048 37 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 18 3885 36 KIDNEY FIBROSIS: FROM MECHANISMS TO THERAPEUTIC MEDICINES. CHRONIC KIDNEY DISEASE (CKD) IS ESTIMATED TO AFFECT 10-14% OF GLOBAL POPULATION. KIDNEY FIBROSIS, CHARACTERIZED BY EXCESSIVE EXTRACELLULAR MATRIX DEPOSITION LEADING TO SCARRING, IS A HALLMARK MANIFESTATION IN DIFFERENT PROGRESSIVE CKD; HOWEVER, AT PRESENT NO ANTIFIBROTIC THERAPIES AGAINST CKD EXIST. KIDNEY FIBROSIS IS IDENTIFIED BY TUBULE ATROPHY, INTERSTITIAL CHRONIC INFLAMMATION AND FIBROGENESIS, GLOMERULOSCLEROSIS, AND VASCULAR RAREFACTION. FIBROTIC NICHE, WHERE ORGAN FIBROSIS INITIATES, IS A COMPLEX INTERPLAY BETWEEN INJURED PARENCHYMA (LIKE TUBULAR CELLS) AND MULTIPLE NON-PARENCHYMAL CELL LINEAGES (IMMUNE AND MESENCHYMAL CELLS) LOCATED SPATIALLY WITHIN SCARRING AREAS. ALTHOUGH THE MECHANISMS OF KIDNEY FIBROSIS ARE COMPLICATED DUE TO THE KINDS OF CELLS INVOLVED, WITH THE HELP OF SINGLE-CELL TECHNOLOGY, MANY KEY QUESTIONS HAVE BEEN EXPLORED, SUCH AS WHAT KIND OF RENAL TUBULES ARE PROFIBROTIC, WHERE MYOFIBROBLASTS ORIGINATE, WHICH IMMUNE CELLS ARE INVOLVED, AND HOW CELLS COMMUNICATE WITH EACH OTHER. IN ADDITION, GENETICS AND EPIGENETICS ARE DEEPER MECHANISMS THAT REGULATE KIDNEY FIBROSIS. AND THE REVERSIBLE NATURE OF EPIGENETIC CHANGES INCLUDING DNA METHYLATION, RNA INTERFERENCE, AND CHROMATIN REMODELING, GIVES AN OPPORTUNITY TO STOP OR REVERSE KIDNEY FIBROSIS BY THERAPEUTIC STRATEGIES. MORE MARKETED (E.G., RAS BLOCKAGE, SGLT2 INHIBITORS) HAVE BEEN DEVELOPED TO DELAY CKD PROGRESSION IN RECENT YEARS. FURTHERMORE, A BETTER UNDERSTANDING OF RENAL FIBROSIS IS ALSO FAVORED TO DISCOVER BIOMARKERS OF FIBROTIC INJURY. IN THE REVIEW, WE UPDATE RECENT ADVANCES IN THE MECHANISM OF RENAL FIBROSIS AND SUMMARIZE NOVEL BIOMARKERS AND ANTIFIBROTIC TREATMENT FOR CKD. 2023 19 4238 30 METHYLATION PATTERN OF URINARY DNA AS A MARKER OF KIDNEY FUNCTION DECLINE IN DIABETES. INTRODUCTION: RENAL TUBULAR INJURY CONTRIBUTES TO THE DECLINE IN KIDNEY FUNCTION IN PATIENTS WITH DIABETES. CELL TYPE-SPECIFIC DNA METHYLATION PATTERNS HAVE BEEN USED TO CALCULATE PROPORTIONS OF PARTICULAR CELL TYPES. IN THIS STUDY, WE DEVELOPED A METHOD TO DETECT RENAL TUBULAR INJURY IN PATIENTS WITH DIABETES BY DETECTING EXFOLIATED TUBULAR CELLS SHED INTO THE URINE BASED ON TUBULAR CELL-SPECIFIC DNA METHYLATION PATTERNS. RESEARCH DESIGN AND METHODS: WE IDENTIFIED DNA METHYLATION PATTERNS SPECIFIC FOR HUMAN RENAL PROXIMAL TUBULAR CELLS THROUGH COMPARTMENT-SPECIFIC METHYLOME ANALYSIS. WE NEXT DETERMINED THE METHYLATION LEVELS OF PROXIMAL TUBULE-SPECIFIC LOCI IN URINE SEDIMENT OF PATIENTS WITH DIABETES AND ANALYZED CORRELATION WITH CLINICAL VARIABLES. RESULTS: WE IDENTIFIED GENOMIC LOCI IN SMTNL2 AND G6PC TO BE SELECTIVELY UNMETHYLATED IN HUMAN PROXIMAL TUBULAR CELLS. THE METHYLATION LEVELS OF SMTNL2 AND G6PC IN URINE SEDIMENT, DEEMED TO REFLECT THE PROPORTION OF EXFOLIATED PROXIMAL TUBULAR CELLS DUE TO INJURY, CORRELATED WELL WITH EACH OTHER. METHYLATION LEVELS OF SMTNL2 IN URINE SEDIMENT SIGNIFICANTLY CORRELATED WITH THE ANNUAL DECLINE IN ESTIMATED GLOMERULAR FILTRATION RATE. MOREOVER, ADDITION OF URINARY SMTNL2 METHYLATION TO A MODEL CONTAINING KNOWN RISK FACTORS SIGNIFICANTLY IMPROVED DISCRIMINATION OF PATIENTS WITH DIABETES WITH FASTER ESTIMATED GLOMERULAR FILTRATION RATE DECLINE. CONCLUSIONS: THIS STUDY DEMONSTRATES THAT PATIENTS WITH DIABETES WITH CONTINUAL LOSS IN KIDNEY FUNCTION MAY BE STRATIFIED BY A SPECIFIC DNA METHYLATION SIGNATURE THROUGH EPIGENETIC URINALYSIS AND PROVIDES FURTHER EVIDENCE AT THE LEVEL OF EXFOLIATED CELLS IN THE URINE THAT INJURY OF PROXIMAL TUBULAR CELLS MAY CONTRIBUTE TO PATHOGENESIS OF DIABETIC KIDNEY DISEASE. 2020 20 4574 38 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