1 3206 184 HDAC9 IS AN EPIGENETIC REPRESSOR OF KIDNEY ANGIOTENSINOGEN ESTABLISHING A SEX DIFFERENCE. BACKGROUND: SEXUAL DIFFERENCE HAS BEEN SHOWN IN THE PATHOGENESIS OF CHRONIC KIDNEY DISEASE INDUCED BY HYPERTENSION. FEMALES ARE PROTECTED FROM HYPERTENSION AND RELATED END-ORGAN DAMAGE. AUGMENTATION OF RENAL PROXIMAL TUBULAR ANGIOTENSINOGEN (AGT) EXPRESSION CAN PROMOTE INTRARENAL ANGIOTENSIN FORMATION AND THE DEVELOPMENT OF ASSOCIATED HYPERTENSION AND KIDNEY INJURY. FEMALE RODENTS EXHIBIT LOWER INTRARENAL AGT LEVELS THAN MALES UNDER NORMAL CONDITIONS, SUGGESTING THAT THE SUPPRESSED INTRARENAL AGT PRODUCTION BY PROGRAMMED MECHANISMS IN FEMALES MAY PROVIDE PROTECTION FROM THESE DISEASES. THIS STUDY WAS PERFORMED TO EXAMINE WHETHER EPIGENETIC MECHANISMS SERVE AS REPRESSORS OF AGT. METHODS: MALE AND FEMALE SPRAGUE DAWLEY RATS WERE USED TO INVESTIGATE SEX DIFFERENCES OF SYSTEMIC, HEPATIC, AND INTRARENAL AGT LEVELS. ALL HISTONE DEACETYLASE (HDAC) MRNA LEVELS IN THE KIDNEYS WERE DETERMINED USING A PCR ARRAY. HDAC9 PROTEIN EXPRESSION IN THE KIDNEYS AND CULTURED RENAL PROXIMAL TUBULAR CELLS (PTC) WAS ANALYZED BY WESTERN BLOT ANALYSIS AND IMMUNOHISTOCHEMISTRY. THE EFFECTS OF HDAC9 ON AGT EXPRESSION WERE EVALUATED BY USING AN INHIBITOR AND SIRNA. CHIP ASSAY WAS PERFORMED TO INVESTIGATE THE INTERACTION BETWEEN THE AGT PROMOTER AND HDAC9. RESULTS: PLASMA AND LIVER AGT LEVELS DID NOT SHOW DIFFERENCES BETWEEN MALE AND FEMALE SPRAGUE-DAWLEY RATS. IN CONTRAST, FEMALES EXHIBITED LOWER AGT LEVELS THAN MALES IN THE RENAL CORTEX AND URINE. IN THE ABSENCE OF SUPPLEMENTED SEX HORMONES, PRIMARY CULTURED RENAL CORTICAL CELLS ISOLATED FROM FEMALE RATS SUSTAINED LOWER AGT LEVELS THAN THOSE FROM MALES, SUGGESTING THAT THE KIDNEYS HAVE A UNIQUE MECHANISM OF AGT REGULATION CONTROLLED BY EPIGENETIC FACTORS RATHER THAN SEX HORMONES. HDAC9 MRNA AND PROTEIN LEVELS WERE HIGHER IN THE RENAL CORTEX OF FEMALE RATS VERSUS MALE RATS (7.09 +/- 0.88, RATIO TO MALE) WHILE OTHER HDACS DID NOT EXHIBIT A SEX DIFFERENCE. HDAC9 EXPRESSION WAS LOCALIZED IN PTC WHICH ARE THE PRIMARY SOURCE OF INTRARENAL AGT. IMPORTANTLY, HDAC9 KNOCKDOWN AUGMENTED AGT MRNA (1.92 +/- 0.35-FOLD) AND PROTEIN (2.25 +/- 0.50-FOLD) LEVELS, SIMILAR TO AN HDAC9 INHIBITOR. FURTHERMORE, AN INTERACTION BETWEEN HDAC9 AND A DISTAL 5' FLANKING REGION OF AGT VIA A HISTONE COMPLEX CONTAINING H3 AND H4 WAS DEMONSTRATED. CONCLUSIONS: THESE RESULTS INDICATE THAT HDAC9 IS A NOVEL SUPPRESSING FACTOR INVOLVED IN AGT REGULATION IN PTC, LEADING TO LOW LEVELS OF INTRARENAL AGT IN FEMALES. THESE FINDINGS WILL HELP TO DELINEATE MECHANISMS UNDERLYING SEX DIFFERENCES IN THE DEVELOPMENT OF HYPERTENSION AND RENIN-ANGIOTENSIN SYSTEM (RAS) ASSOCIATED KIDNEY INJURY. 2017 2 3663 21 INDUCTION OF TET3-DEPENDENT EPIGENETIC REMODELING BY LOW-DOSE HYDRALAZINE ATTENUATES PROGRESSION OF CHRONIC KIDNEY DISEASE. PROGRESSION OF CHRONIC KIDNEY DISEASE REMAINS A PRINCIPAL PROBLEM IN CLINICAL NEPHROLOGY AND THERE IS A PRESSING NEED FOR NOVEL THERAPEUTICS AND BIOMARKERS. ABERRANT PROMOTER CPG ISLAND METHYLATION AND SUBSEQUENT TRANSCRIPTIONAL SILENCING OF SPECIFIC GENES HAVE EMERGED AS CONTRIBUTORS TO PROGRESSION OF CHRONIC KIDNEY DISEASE. HERE, WE REPORT THAT TRANSCRIPTIONAL SILENCING OF THE RAS-GTP SUPPRESSOR RASAL1 CONTRIBUTES CAUSALLY TO PROGRESSION OF KIDNEY FIBROSIS AND WE IDENTIFIED THAT CIRCULATING METHYLATED RASAL1 PROMOTER DNA FRAGMENTS IN PERIPHERAL BLOOD CORRESPOND WITH LEVELS OF INTRARENAL LEVELS OF RASAL1 PROMOTER METHYLATION AND DEGREE OF FIBROSIS IN KIDNEY BIOPSIES, ENABLING NON-INVASIVE LONGITUDINAL ANALYSIS OF INTRARENAL CPG ISLAND METHYLATION. 2015 3 3358 36 HISTONE H3K9 METHYLATION REGULATES CHRONIC STRESS AND IL-6-INDUCED COLON EPITHELIAL PERMEABILITY AND VISCERAL PAIN. BACKGROUND: CHRONIC STRESS IS ASSOCIATED WITH ACTIVATION OF THE HPA AXIS, ELEVATION IN PRO-INFLAMMATORY CYTOKINES, DECREASE IN INTESTINAL EPITHELIAL CELL TIGHT JUNCTION (TJ) PROTEINS, AND ENHANCED VISCERAL PAIN. IT IS UNKNOWN WHETHER EPIGENETIC REGULATORY PATHWAYS PLAY A ROLE IN CHRONIC STRESS-INDUCED INTESTINAL BARRIER DYSFUNCTION AND VISCERAL HYPERALGESIA. METHODS: YOUNG ADULT MALE RATS WERE SUBJECTED TO WATER AVOIDANCE STRESS +/- H3K9 METHYLATION INHIBITORS OR SIRNAS. VISCERAL PAIN RESPONSE WAS ASSESSED. DIFFERENTIATED CACO-2/BBE CELLS AND HUMAN COLONOIDS WERE TREATED WITH CORTISOL OR IL-6 +/- ANTAGONISTS. EXPRESSION OF TJ, IL-6, AND H3K9 METHYLATION STATUS AT GENE PROMOTERS WAS MEASURED. TRANSEPITHELIAL ELECTRICAL RESISTANCE AND FITC-DEXTRAN PERMEABILITY WERE EVALUATED. KEY RESULTS: CHRONIC STRESS INDUCED IL-6 UP-REGULATION PRIOR TO A DECREASE IN TJ PROTEINS IN THE RAT COLON. THE IL-6 LEVEL INVERSELY CORRELATED WITH OCCLUDIN EXPRESSION. TREATMENT WITH IL-6 DECREASED OCCLUDIN AND INDUCED VISCERAL HYPERALGESIA. CHRONIC STRESS AND IL-6 INCREASED H3K9 METHYLATION AND DECREASED TRANSCRIPTIONAL GR BINDING TO THE OCCLUDIN GENE PROMOTER, LEADING TO DOWN-REGULATION OF PROTEIN EXPRESSION AND INCREASE IN PARACELLULAR PERMEABILITY. INTRARECTAL ADMINISTRATION OF A H3K9 METHYLATION ANTAGONIST PREVENTED CHRONIC STRESS-INDUCED VISCERAL HYPERALGESIA IN THE RAT. IN A HUMAN COLONOID MODEL, CORTISOL DECREASED OCCLUDIN EXPRESSION, WHICH WAS PREVENTED BY THE GR ANTAGONIST RU486, AND IL-6 INCREASED H3K9 METHYLATION AND DECREASED TJ PROTEIN LEVELS, WHICH WERE PREVENTED BY INHIBITORS OF H3K9 METHYLATION. CONCLUSIONS & INFERENCES: OUR FINDINGS SUPPORT A NOVEL ROLE FOR METHYLATION OF THE REPRESSIVE HISTONE H3K9 TO REGULATE CHRONIC STRESS, PRO-INFLAMMATORY CYTOKINE-MEDIATED REDUCTION IN COLON TJ PROTEIN LEVELS, AND INCREASE IN PARACELLULAR PERMEABILITY AND VISCERAL HYPERALGESIA. 2020 4 3451 34 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 5 2001 34 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 6 4016 34 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 5442 35 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 8 766 44 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 5504 36 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 10 1123 31 COMPLEMENT COMPONENT C5A INDUCES ABERRANT EPIGENETIC MODIFICATIONS IN RENAL TUBULAR EPITHELIAL CELLS ACCELERATING SENESCENCE BY WNT4/BETACATENIN SIGNALING AFTER ISCHEMIA/REPERFUSION INJURY. EPIGENETIC MECHANISMS, SUCH AS DNA METHYLATION, AFFECT TUBULAR MALADAPTIVE RESPONSE AFTER ACUTE KIDNEY INJURY (AKI) AND ACCELERATE RENAL AGING. UPON ISCHEMIA/REPERFUSION (I/R) INJURY, COMPLEMENT ACTIVATION LEADS TO C5A RELEASE THAT MEDIATES DAMAGE; HOWEVER, LITTLE IS KNOWN ABOUT THE EFFECT OF C5A-C5A RECEPTOR (C5AR) INTERACTION IN RENAL TUBULAR EPITHELIAL CELLS (RTEC).THROUGH A WHOLE-GENOME DNA METHYLATION ANALYSIS IN CULTURED RTEC, WE FOUND THAT C5A INDUCED ABERRANT METHYLATION, PARTICULARLY IN REGIONS INVOLVED IN CELL CYCLE CONTROL, DNA DAMAGE AND WNT SIGNALING. THE MOST REPRESENTED GENES WERE BCL9, CYP1B1 AND CDK6. C5A STIMULATION OF RTEC LED TO UP-REGULATION OF SA-BETA GAL AND CELL CYCLE ARREST MARKERS SUCH AS P53 AND P21. C5A INCREASED ALSO IL-6, MCP-1 AND CTGF GENE EXPRESSION, CONSISTENT WITH SASP DEVELOPMENT. IN ACCORDANCE, IN A SWINE MODEL OF RENAL I/R INJURY, WE FOUND THE INCREASED EXPRESSION OF WNT4 AND BETACATENIN CORRELATING WITH SA-BETA GAL, P21, P16 AND IL-6 POSITIVITY. ADMINISTRATION OF COMPLEMENT INHIBITOR (C1-INH), ANTAGONIZED SASP BY REDUCING SA-BETA GAL, P21, P16, IL-6 AND ABROGATING WNT4/BETACATENIN ACTIVATION.THUS, C5A AFFECTS THE DNA METHYLATION OF GENES INVOLVED IN TUBULAR SENESCENCE. TARGETING EPIGENETIC PROGRAMS AND COMPLEMENT MAY OFFER NOVELS STRATEGIES TO PROTECT TUBULAR CELLS FROM ACCELERATED AGING AND TO COUNTERACT PROGRESSION TO CHRONIC KIDNEY DISEASE. 2019 11 4226 29 METHYLATION IN PERICYTES AFTER ACUTE INJURY PROMOTES CHRONIC KIDNEY DISEASE. THE ORIGIN AND FATE OF RENAL MYOFIBROBLASTS IS NOT CLEAR AFTER ACUTE KIDNEY INJURY (AKI). HERE, WE DEMONSTRATE THAT MYOFIBROBLASTS WERE ACTIVATED FROM QUIESCENT PERICYTES (QPERICYTES) AND THE CELL NUMBERS INCREASED AFTER ISCHEMIA/REPERFUSION INJURY-INDUCED AKI (IRI-AKI). MYOFIBROBLASTS UNDERWENT APOPTOSIS DURING RENAL RECOVERY BUT ONE-FIFTH OF THEM SURVIVED IN THE RECOVERED KIDNEYS ON DAY 28 AFTER IRI-AKI AND THEIR CELL NUMBERS INCREASED AGAIN AFTER DAY 56. MICROARRAY DATA SHOWED THE DISTINCTIVE GENE EXPRESSION PATTERNS OF QPERICYTES, ACTIVATED PERICYTES (APERICYTES, MYOFIBROBLASTS), AND INACTIVATED PERICYTES (IPERICYTES) ISOLATED FROM KIDNEYS BEFORE, ON DAY 7, AND ON DAY 28 AFTER IRI-AKI. HYPERMETHYLATION OF THE ACTA2 REPRESSOR YBX2 DURING IRI-AKI RESULTED IN EPIGENETIC MODIFICATION OF IPERICYTES TO PROMOTE THE TRANSITION TO CHRONIC KIDNEY DISEASE (CKD) AND AGGRAVATED FIBROGENESIS INDUCED BY A SECOND AKI INDUCED BY ADENINE. MECHANISTICALLY, TRANSFORMING GROWTH FACTOR-BETA1 DECREASED THE BINDING OF YBX2 TO THE PROMOTER OF ACTA2 AND INDUCED YBX2 HYPERMETHYLATION, THEREBY INCREASING ALPHA-SMOOTH MUSCLE ACTIN EXPRESSION IN APERICYTES. DEMETHYLATION BY 5-AZACYTIDINE RECOVERED THE MICROVASCULAR STABILIZING FUNCTION OF APERICYTES, REVERSED THE PROFIBROTIC PROPERTY OF IPERICYTES, PREVENTED AKI-CKD TRANSITION, AND ATTENUATED FIBROGENESIS INDUCED BY A SECOND ADENINE-AKI. IN CONCLUSION, INTERVENTION TO ERASE HYPERMETHYLATION OF PERICYTES AFTER AKI PROVIDES A STRATEGY TO STOP THE TRANSITION TO CKD. 2020 12 4001 52 LOSS OF MEN1 LEADS TO RENAL FIBROSIS AND DECREASES HGF-ADAMTS5 PATHWAY ACTIVITY VIA AN EPIGENETIC MECHANISM. BACKGROUND: RENAL FIBROSIS IS A SERIOUS CONDITION THAT RESULTS IN THE DEVELOPMENT OF CHRONIC KIDNEY DISEASES. THE MEN1 GENE IS AN EPIGENETIC REGULATOR THAT ENCODES THE MENIN PROTEIN AND ITS ROLE IN KIDNEY TISSUE REMAINS UNCLEAR. METHODS: KIDNEY HISTOLOGY WAS EXAMINED ON PARAFFIN SECTIONS STAINED WITH HEMATOXYLIN-EOSIN STAINING. MASSON'S TRICHROME STAINING AND SIRIUS RED STAINING WERE USED TO ANALYZE RENAL FIBROSIS. GENE AND PROTEIN EXPRESSION WERE DETERMINED BY QUANTITATIVE REAL-TIME PCR (QPCR) AND WESTERN BLOT, RESPECTIVELY. IMMUNOHISTOCHEMISTRY STAINING IN THE KIDNEY TISSUES FROM MICE OR PATIENTS WAS USED TO EVALUATE PROTEIN LEVELS. FLOW CYTOMETRY WAS USED TO ANALYZE THE CELL CYCLE DISTRIBUTIONS AND APOPTOSIS. RNA-SEQUENCING WAS PERFORMED FOR DIFFERENTIAL EXPRESSION GENES IN THE KIDNEY TISSUES OF THE MEN1F/F AND MEN1?/? MICE. CHROMATIN IMMUNOPRECIPITATION SEQUENCING (CHIP-SEQ) WAS CARRIED OUT FOR IDENTIFICATION OF MENIN- AND H3K4ME3-ENRICHED REGIONS WITHIN THE WHOLE GENOME IN THE MOUSE KIDNEY TISSUE. CHIP-QPCR ASSAYS WERE PERFORMED FOR OCCUPANCY OF MENIN AND H3K4ME3 AT THE GENE PROMOTER REGIONS. LUCIFERASE REPORTER ASSAY WAS USED TO DETECT THE PROMOTER ACTIVITY. THE EXACERBATED UNILATERAL URETERAL OBSTRUCTION (UUO) MODELS IN THE MEN1F/F AND MEN1?/? MICE WERE USED TO ASSESS THE PHARMACOLOGICAL EFFECTS OF RH-HGF ON RENAL FIBROSIS. RESULTS: THE EXPRESSION OF MEN1 IS REDUCE IN KIDNEY TISSUES OF FIBROTIC MOUSE AND HUMAN DIABETIC PATIENTS AND TREATMENT WITH FIBROTIC FACTOR RESULTS IN THE DOWNREGULATION OF MEN1 EXPRESSION IN RENAL TUBULAR EPITHELIAL CELLS (RTECS). DISRUPTION OF MEN1 IN RTECS LEADS TO HIGH EXPRESSION OF ALPHA-SMA AND COLLAGEN 1, WHEREAS MEN1 OVEREXPRESSION RESTRAINS EPITHELIAL-TO-MESENCHYMAL TRANSITION (EMT) INDUCED BY TGF-BETA TREATMENT. CONDITIONAL KNOCKOUT OF MEN1 RESULTED IN CHRONIC RENAL FIBROSIS AND UUO-INDUCED TUBULOINTERSTITIAL FIBROSIS (TIF), WHICH IS ASSOCIATED WITH AN INCREASED INDUCTION OF EMT, G2/M ARREST AND JNK SIGNALING. MECHANISTICALLY, MENIN RECRUITS AND INCREASES H3K4ME3 AT THE PROMOTER REGIONS OF HEPATOCYTE GROWTH FACTOR (HGF) AND A DISINTEGRIN AND METALLOPROTEINASE WITH THROMBOSPONDIN MOTIFS 5 (ADAMTS5) GENES AND ENHANCES THEIR TRANSCRIPTIONAL ACTIVATION. IN THE UUO MICE MODEL, EXOGENOUS HGF RESTORED THE EXPRESSION OF ADAMTS5 AND AMELIORATED RENAL FIBROSIS INDUCED BY MEN1 DEFICIENCY. CONCLUSIONS: THESE FINDINGS DEMONSTRATE THAT MEN1 IS AN ESSENTIAL ANTIFIBROTIC FACTOR IN RENAL FIBROGENESIS AND COULD BE A POTENTIAL TARGET FOR ANTIFIBROTIC THERAPY. 2022 13 2349 57 EPIGENETIC REGULATION OF MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX PRODUCTION IN NASAL POLYP-DERIVED FIBROBLASTS. BACKGROUND: NASAL POLYPOSIS IS A MULTI-FACTORIAL DISEASE ASSOCIATED WITH CHRONIC INFLAMMATORY CONDITION OF THE PARANASAL SINUSES. MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX (ECM) ACCUMULATION ARE INVOLVED IN THE PATHOGENESIS OF NASAL POLYPOSIS. OBJECTIVE: THE AIM OF THIS STUDY WAS TO STUDY THE EFFECT OF TRICHOSTATIN A (TSA), A HISTONE DEACETYLASE (HDAC) INHIBITOR, ON TRANSFORMING GROWTH FACTOR (TGF)-BETA1-INDUCED MYOFIBROBLAST DIFFERENTIATION AND ECM ACCUMULATION IN NASAL POLYP-DERIVED FIBROBLASTS (NPDFS). METHODS: NASAL POLYP-DERIVED FIBROBLASTS WERE ISOLATED FROM NASAL POLYPS OF PATIENTS WHO HAVE CHRONIC RHINOSINUSITIS WITH NASAL POLYP. TSA WAS TREATED IN TGF-BETA1-INDUCED NPDFS. EXPRESSION LEVELS OF HDAC2, ALPHA-SMOOTH MUSCLE ACTIN (SMA), TGF-BETA1, COLLAGEN TYPE I, ACETYLATED HISTONE H3, ACETYLATED HISTONE H4, PHOSPHORYLATED SMAD2/3 AND SMAD7 WERE DETERMINED BY RT-PCR, WESTERN BLOT AND/OR IMMUNOFLUORESCENT STAINING. THE TOTAL COLLAGEN AMOUNT PRODUCTION WAS ANALYSED BY SIRCOL SOLUBLE COLLAGEN ASSAY AND CONTRACTILE ACTIVITY WAS MEASURED BY COLLAGEN GEL CONTRACTION ASSAY. HDAC2 INHIBITION BY TSA OR HDAC2 SILENCING WAS ESTABLISHED BY RT-PCR AND WESTERN BLOT. THE EPIGENETIC EFFECT ON ALPHA-SMA GENE INACTIVATION WAS EXAMINED BY CHROMATIN IMMUNOPRECIPITATION ASSAY. PROLIFERATION WAS DETERMINED BY KI67-POSITIVE CELL STAINING AND CYTOTOXICITY WAS ASSESSED BY 3-(4,5- DIMETHYLTHIAZOL-2YL)-2,5-DIPHENYL-2H-TETRAZOLIUM BROMIDE (MTT) ASSAY. RESULTS: THE EXPRESSION LEVELS OF HDAC2, ALPHA-SMA AND TGF-BETA1 WERE INCREASED IN NASAL POLYP TISSUES COMPARED TO NORMAL INFERIOR TURBINATE TISSUES. TSA AND HDAC2 SILENCING INHIBITED EXPRESSION LEVELS ALPHA-SMA, COLLAGEN AND HDAC2. TSA INDUCED HYPERACETYLATION OF HISTONE AND SUPPRESSED OPENING OF ALPHA-SMA GENE PROMOTER IN TGF-BETA1-INDUCED NPDFS. TSA INHIBITED TGF-BETA1-INDUCED SMAD 2/3 AND RESCUED TGF-BETA1-SUPPRESSED SMAD7 SIGNALLING PATHWAY. FINALLY, TSA BLOCKED PROLIFERATION IN TGF-BETA1-INDUCED NPDFS AND HAS NO CYTOTOXIC EFFECT IN NPDFS. CONCLUSIONS AND CLINICAL RELEVANCE: THESE RESULTS SUGGEST THAT HDAC INHIBITION IS ASSOCIATED WITH MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLUAR MATRIX ACCUMULATION IN NASAL POLYPOSIS. TSA MAY BE USEFUL AS AN INHIBITOR OF NASAL POLYP GROWTH, AND THUS HAS POTENTIAL TO BE USED AS A NOVEL TREATMENT OPTION FOR NASAL POLYPOSIS. 2012 14 1274 40 DACH1 PROTECTS PODOCYTES FROM EXPERIMENTAL DIABETIC INJURY AND MODULATES PTIP-H3K4ME3 ACTIVITY. DACHSHUND HOMOLOG 1 (DACH1), A KEY CELL-FATE DETERMINANT, REGULATES TRANSCRIPTION BY DNA SEQUENCE-SPECIFIC BINDING. WE IDENTIFIED DIMINISHED DACH1 EXPRESSION IN A LARGE-SCALE SCREEN FOR MUTATIONS THAT CONVERT INJURY-RESISTANT PODOCYTES INTO INJURY-SUSCEPTIBLE PODOCYTES. IN DIABETIC KIDNEY DISEASE (DKD) PATIENTS, PODOCYTE DACH1 EXPRESSION LEVELS ARE DIMINISHED, A CONDITION THAT STRONGLY CORRELATES WITH POOR CLINICAL OUTCOMES. GLOBAL DACH1 KO MICE MANIFEST RENAL HYPOPLASIA AND DIE PERINATALLY. PODOCYTE-SPECIFIC DACH1 KO MICE, HOWEVER, MAINTAIN NORMAL GLOMERULAR ARCHITECTURE AT BASELINE, BUT RAPIDLY EXHIBIT PODOCYTE INJURY AFTER DIABETES ONSET. FURTHERMORE, PODOCYTE-SPECIFIC AUGMENTATION OF DACH1 EXPRESSION IN MICE PROTECTS FROM DKD. COMBINED RNA SEQUENCING AND IN SILICO PROMOTER ANALYSIS REVEAL CONVERSELY OVERLAPPING GLOMERULAR TRANSCRIPTOMIC SIGNATURES BETWEEN PODOCYTE-SPECIFIC DACH1 AND PAX TRANSACTIVATION-DOMAIN INTERACTING PROTEIN (PTIP) KO MICE, WITH UPREGULATED GENES POSSESSING HIGHER-THAN-EXPECTED NUMBERS OF PROMOTER DACH1-BINDING SITES. PTIP, AN ESSENTIAL COMPONENT OF THE ACTIVATING HISTONE H3 LYSINE 4 TRIMETHYLATION (H3K4ME3) COMPLEX, INTERACTS WITH DACH1 AND IS RECRUITED BY DACH1 TO ITS PROMOTER-BINDING SITES. DACH1-PTIP RECRUITMENT REPRESSES TRANSCRIPTION AND REDUCES PROMOTER H3K4ME3 LEVELS. DACH1 KNOCKDOWN IN PODOCYTES COMBINED WITH HYPERGLYCEMIA TRIGGERS TARGET GENE UPREGULATION AND INCREASES PROMOTER H3K4ME3. THESE FINDINGS REVEAL THAT IN DKD, DIMINISHED DACH1 EXPRESSION ENHANCES PODOCYTE INJURY VULNERABILITY VIA EPIGENETIC DEREPRESSION OF ITS TARGET GENES. 2021 15 5990 33 TGF-BETA1 PROMOTES EXPRESSION OF FIBROSIS-RELATED GENES THROUGH THE INDUCTION OF HISTONE VARIANT H3.3 AND HISTONE CHAPERONE HIRA. RENAL FIBROSIS IS A HISTOLOGICAL MANIFESTATION THAT OCCURS IN ALMOST EVERY TYPE OF CHRONIC KIDNEY DISEASE. HISTONE VARIANT H3.3 AND ITS CHAPERONE, HISTONE CELL CYCLE REGULATION DEFECTIVE HOMOLOG A (HIRA), SERVE AS EPIGENETIC MARKS THAT REGULATE TRANSCRIPTIONAL ACTIVITY. IN THIS STUDY, WE ASSESSED THE ROLES OF HISTONE H3.3 AND HIRA IN UNILATERAL URETERAL-OBSTRUCTION (UUO) MICE. IN UUO MICE, THE LEVELS OF HISTONE H3.3 AND HIRA WERE SIGNIFICANTLY UPREGULATED IN THE KIDNEYS. THESE UPREGULATED LEVELS WERE DECREASED BY A TGF-BETA1 NEUTRALIZING ANTIBODY. TGF-BETA1 INDUCED HISTONE H3.3 AND HIRA EXPRESSION IN VITRO VIA A SMAD3-DEPENDENT PATHWAY IN NORMAL RAT KIDNEY (NRK)-52E CELLS. ADDITIONALLY, KNOCKDOWN OF HIRA EXPRESSION DECREASED HISTONE H3.3 EXPRESSION AND FIBROGENESIS IN NRK-52E CELLS AFTER TGF-BETA1 STIMULATION. CHROMATIN IMMUNOPRECIPITATION ANALYSIS REVEALED THAT PROMOTERS OF FIBROSIS-RELATED GENES WERE IMMUNOPRECIPITATED WITH BOTH HISTONE H3.3 AND HIRA IN NRK-52E CELLS. LASTLY, IN HUMAN KIDNEY BIOPSIES FROM PATIENTS DIAGNOSED WITH IGA NEPHROPATHY, HISTONE H3.3 AND HIRA IMMUNOSTAINING CORRELATED POSITIVELY WITH AREAS OF FIBROSIS AND ESTIMATED GLOMERULAR FILTRATION RATE. IN CONCLUSION, TGF-BETA1 INDUCES EXPRESSION OF HISTONE H3.3 AND HIRA, WHICH REGULATES EXPRESSION OF FIBROSIS-RELATED GENES. 2018 16 1690 36 DUAL ROLES OF CHROMATIN REMODELING PROTEIN BRG1 IN ANGIOTENSIN II-INDUCED ENDOTHELIAL-MESENCHYMAL TRANSITION. ENDOTHELIAL-MESENCHYMAL TRANSITION (ENDMT) IS CONSIDERED ONE OF THE PROCESSES UNDERLYING TISSUE FIBROSIS BY CONTRIBUTING TO THE POOL OF MYOFIBROBLASTS. IN THE PRESENT STUDY, WE INVESTIGATED THE EPIGENETIC MECHANISM WHEREBY ANGIOTENSIN II (ANG II) REGULATES ENDMT TO PROMOTE CARDIAC FIBROSIS FOCUSING ON THE ROLE OF CHROMATIN REMODELING PROTEIN BRG1. BRG1 KNOCKDOWN OR INHIBITION ATTENUATED ANG II-INDUCED ENDMT, AS EVIDENCED BY DOWN-REGULATION OF CDH5, AN ENDOTHELIAL MARKER, AND UP-REGULATION OF COL1A2, A MESENCHYMAL MARKER, IN CULTURED VASCULAR ENDOTHELIAL CELLS. ON THE ONE HAND, BRG1 INTERACTED WITH AND WAS RECRUITED BY SP1 TO THE SNAI2 (ENCODING SLUG) PROMOTER TO ACTIVATE SNAI2 TRANSCRIPTION IN RESPONSE TO ANG II STIMULATION. ONCE ACTIVATED, SLUG BOUND TO THE CDH5 PROMOTER TO REPRESS CDH5 TRANSCRIPTION. ON THE OTHER HAND, BRG1 INTERACTED WITH AND WAS RECRUITED BY SRF TO THE COL1A2 PROMOTER TO ACTIVATE COL1A2 TRANSCRIPTION. MECHANISTICALLY, BRG1 EVICTED HISTONES FROM THE TARGET PROMOTERS TO FACILITATE THE BINDINGS OF SP1 AND SRF. FINALLY, ENDOTHELIAL CONDITIONAL BRG1 KNOCKOUT MICE (CKO) EXHIBITED A REDUCTION IN CARDIAC FIBROSIS, COMPARED TO THE WILD TYPE (WT) LITTERMATES, IN RESPONSE TO CHRONIC ANG II INFUSION. IN CONCLUSION, OUR DATA DEMONSTRATE THAT BRG1 IS A KEY TRANSCRIPTIONAL COORDINATOR PROGRAMMING ANG II-INDUCED ENDMT TO CONTRIBUTE TO CARDIAC FIBROSIS. 2020 17 6298 40 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 18 5401 52 REDUCTION OF SIRT1 EPIGENETICALLY UPREGULATES NALP1 EXPRESSION AND CONTRIBUTES TO NEUROPATHIC PAIN INDUCED BY CHEMOTHERAPEUTIC DRUG BORTEZOMIB. BACKGROUND: BORTEZOMIB IS A FREQUENTLY USED CHEMOTHERAPEUTIC DRUG FOR THE TREATMENT OF MULTIPLE MYELOMA AND OTHER NONSOLID MALIGNANCIES. ACCUMULATING EVIDENCE HAS DEMONSTRATED THAT BORTEZOMIB-INDUCED PERSISTENT PAIN SERVES AS THE MOST FREQUENT REASON FOR TREATMENT DISCONTINUATION. METHODS: THE VON FREY TEST WAS PERFORMED TO EVALUATE NEUROPATHIC PAIN BEHAVIOR, AND REAL-TIME QUANTITATIVE REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION, CHROMATIN IMMUNOPRECIPITATION, WESTERN BLOT, IMMUNOHISTOCHEMISTRY, AND SMALL INTERFERING RNA WERE PERFORMED TO EXPLORE THE MOLECULAR MECHANISMS IN ADULT MALE SPRAGUE-DAWLEY RATS. RESULTS: WE FOUND THAT APPLICATION OF BORTEZOMIB SIGNIFICANTLY INCREASED THE EXPRESSION OF NALP1 PROTEIN AND MRNA LEVELS IN SPINAL DORSAL HORN NEURONS, AND INTRATHECAL APPLICATION OF NALP1 SIRNA ATTENUATED THE BORTEZOMIB-INDUCED MECHANICAL ALLODYNIA. IN ADDITION, BORTEZOMIB ALSO DECREASED THE SIRT1 EXPRESSION, AND TREATMENT WITH SIRT1 ACTIVATOR RESVERATROL AMELIORATED THE NALP1 UPREGULATION AND MECHANICAL ALLODYNIA INDUCED BY BORTEZOMIB. MEANWHILE, KNOCKDOWN OF SIRT1 USING THE SIRT1 SIRNA INDUCED THE NALP1 UPREGULATION IN DORSAL HORN AND MECHANICAL ALLODYNIA IN NORMAL ANIMAL. THESE RESULTS SUGGESTED THAT REDUCTION OF SIRT1 INDUCED THE NALP1 UPREGULATION IN DORSAL HORN NEURONS, AND PARTICIPATED IN BORTEZOMIB-INDUCED MECHANICAL ALLODYNIA. IMPORTANTLY, WE FOUND THAT THE BINDING OF SIRT1 AND NALP1 PROMOTER REGION DID NOT CHANGE BEFORE AND AFTER BORTEZOMIB TREATMENT, BUT SIRT1 DOWNREGULATION INCREASED P-STAT3 EXPRESSION. FURTHERMORE, THE ACTIVATION OF STAT3 ENHANCED THE RECRUITMENT OF P-STAT3 TO THE NALP1 GENE PROMOTER, WHICH INCREASED THE ACETYLATION OF HISTONE H3 AND H4 IN NALP1 PROMOTER REGIONS AND EPIGENETICALLY UPREGULATED NALP1 EXPRESSION IN THE RODENTS WITH BORTEZOMIB TREATMENT. CONCLUSION: THESE FINDINGS SUGGESTED A NEW EPIGENETIC MECHANISM FOR NALP1 UPREGULATION INVOLVING SIRT1 REDUCTION AND SUBSEQUENT STAT3-MEDIATED HISTONE HYPERACETYLATION IN NALP1 PROMOTER REGION IN DORSAL HORN NEURONS, WHICH CONTRIBUTED TO THE BORTEZOMIB-INDUCED MECHANICAL ALLODYNIA. 2018 19 4146 29 MECHANISMS REGULATING MUSCLE PROTEIN SYNTHESIS IN CKD. BACKGROUND: CKD INDUCES LOSS OF MUSCLE PROTEINS PARTLY BY SUPPRESSING MUSCLE PROTEIN SYNTHESIS. MUSCLES OF MICE WITH CKD HAVE INCREASED EXPRESSION OF NUCLEOLAR PROTEIN 66 (NO66), AS DO MUSCLE BIOPSY SPECIMENS FROM PATIENTS WITH CKD OR THOSE UNDERGOING HEMODIALYSIS. INFLAMMATION STIMULATES NO66 EXPRESSION AND CHANGES IN NF-KAPPAB MEDIATE THE RESPONSE. METHODS: SUBTOTAL NEPHRECTOMY CREATED A MOUSE MODEL OF CKD WITH BUN >80 MG/DL. CROSSING NO66(FLOX/FLOX) WITH MCK-CRE MICE BRED MUSCLE-SPECIFIC NO66 (MCK-NO66) KNOCKOUT MICE. EXPERIMENTS ASSESSED THE EFFECT OF REMOVING NO66. RESULTS: MUSCLE-SPECIFIC NO66 KNOCKOUT IN MICE BLOCKS CKD-INDUCED LOSS OF MUSCLE MASS AND IMPROVES PROTEIN SYNTHESIS. NO66 SUPPRESSION OF RIBOSOMAL BIOGENESIS VIA DEMETHYLASE ACTIVITY IS THE MECHANISM BEHIND THESE RESPONSES. IN MUSCLE CELLS, EXPRESSION OF NO66, BUT NOT OF DEMETHYLASE-DEAD MUTANT NO66, DECREASED H3K4ME3 AND H3K36ME3 AND SUPPRESSED PRE-RRNA EXPRESSION. KNOCKING OUT NO66 INCREASED THE ENRICHMENT OF H3K4ME3 AND H3K36ME3 ON RIBOSOMAL DNA. IN PRIMARY MUSCLE CELLS AND IN MUSCLES OF MICE WITHOUT NO66, RIBOSOMAL RNA, PRE-RRNA, AND PROTEIN SYNTHESIS ALL INCREASED. CONCLUSIONS: CKD SUPPRESSES MUSCLE PROTEIN SYNTHESIS VIA EPIGENETIC MECHANISMS THAT NO66 MEDIATES. BLOCKING NO66 COULD SUGGEST STRATEGIES THAT COUNTER CKD-INDUCED ABNORMAL MUSCLE PROTEIN CATABOLISM. 2020 20 4919 36 PANNEXIN-1 UP-REGULATION IN THE DORSAL ROOT GANGLION CONTRIBUTES TO NEUROPATHIC PAIN DEVELOPMENT. PANNEXIN-1 (PANX1) IS A LARGE-PORE MEMBRANE CHANNEL INVOLVED IN THE RELEASE OF ATP AND OTHER SIGNALING MEDIATORS. LITTLE IS KNOWN ABOUT THE EXPRESSION AND FUNCTIONAL ROLE OF PANX1 IN THE DORSAL ROOT GANGLION (DRG) IN THE DEVELOPMENT OF CHRONIC NEUROPATHIC PAIN. IN THIS STUDY, WE DETERMINED THE EPIGENETIC MECHANISM INVOLVED IN INCREASED PANX1 EXPRESSION IN THE DRG AFTER NERVE INJURY. SPINAL NERVE LIGATION IN RATS SIGNIFICANTLY INCREASED THE MRNA AND PROTEIN LEVELS OF PANX1 IN THE DRG BUT NOT IN THE SPINAL CORD. IMMUNOCYTOCHEMICAL LABELING SHOWED THAT PANX1 WAS PRIMARILY EXPRESSED IN A SUBSET OF MEDIUM AND LARGE DRG NEURONS IN CONTROL RATS AND THAT NERVE INJURY MARKEDLY INCREASED THE NUMBER OF PANX1-IMMUNOREACTIVE DRG NEURONS. NERVE INJURY SIGNIFICANTLY INCREASED THE ENRICHMENT OF TWO ACTIVATING HISTONE MARKS (H3K4ME2 AND H3K9AC) AND DECREASED THE OCCUPANCY OF TWO REPRESSIVE HISTONE MARKS (H3K9ME2 AND H3K27ME3) AROUND THE PROMOTER REGION OF PANX1 IN THE DRG. HOWEVER, NERVE INJURY HAD NO EFFECT ON THE DNA METHYLATION LEVEL AROUND THE PANX1 PROMOTER IN THE DRG. FURTHERMORE, INTRATHECAL INJECTION OF THE PANX1 BLOCKERS OR PANX1-SPECIFIC SIRNA SIGNIFICANTLY REDUCED PAIN HYPERSENSITIVITY INDUCED BY NERVE INJURY. IN ADDITION, SIRNA KNOCKDOWN OF PANX1 EXPRESSION IN A DRG CELL LINE SIGNIFICANTLY REDUCED CASPASE-1 RELEASE INDUCED BY NEURONAL DEPOLARIZATION. OUR FINDINGS SUGGEST THAT NERVE INJURY INCREASES PANX1 EXPRESSION LEVELS IN THE DRG THROUGH ALTERED HISTONE MODIFICATIONS. PANX1 UP-REGULATION CONTRIBUTES TO THE DEVELOPMENT OF NEUROPATHIC PAIN AND STIMULATION OF INFLAMMASOME SIGNALING. 2015