1 2117 120 EPIGENETIC HISTONE METHYLATION MODULATES FIBROTIC GENE EXPRESSION. TGF-BETA1-INDUCED EXPRESSION OF EXTRACELLULAR MATRIX (ECM) GENES PLAYS A MAJOR ROLE IN THE DEVELOPMENT OF CHRONIC RENAL DISEASES SUCH AS DIABETIC NEPHROPATHY. ALTHOUGH MANY KEY TRANSCRIPTION FACTORS ARE KNOWN, MECHANISMS INVOLVING THE NUCLEAR CHROMATIN THAT MODULATE ECM GENE EXPRESSION REMAIN UNCLEAR. HERE, WE EXAMINED THE ROLE OF EPIGENETIC CHROMATIN MARKS SUCH AS HISTONE H3 LYSINE METHYLATION (H3KME) IN TGF-BETA1-INDUCED GENE EXPRESSION IN RAT MESANGIAL CELLS UNDER NORMAL AND HIGH-GLUCOSE (HG) CONDITIONS. TGF-BETA1 INCREASED THE EXPRESSION OF THE ECM-ASSOCIATED GENES CONNECTIVE TISSUE GROWTH FACTOR, COLLAGEN-ALPHA1[IOTA], AND PLASMINOGEN ACTIVATOR INHIBITOR-1. INCREASED LEVELS OF CHROMATIN MARKS ASSOCIATED WITH ACTIVE GENES (H3K4ME1, H3K4ME2, AND H3K4ME3), AND DECREASED LEVELS OF REPRESSIVE MARKS (H3K9ME2 AND H3K9ME3) AT THESE GENE PROMOTERS ACCOMPANIED THESE CHANGES IN EXPRESSION. TGF-BETA1 ALSO INCREASED EXPRESSION OF THE H3K4 METHYLTRANSFERASE SET7/9 AND RECRUITMENT TO THESE PROMOTERS. SET7/9 GENE SILENCING WITH SIRNAS SIGNIFICANTLY ATTENUATED TGF-BETA1-INDUCED ECM GENE EXPRESSION. FURTHERMORE, A TGF-BETA1 ANTIBODY NOT ONLY BLOCKED HG-INDUCED ECM GENE EXPRESSION BUT ALSO REVERSED HG-INDUCED CHANGES IN PROMOTER H3KME LEVELS AND SET7/9 OCCUPANCY. TAKEN TOGETHER, THESE RESULTS SHOW THE FUNCTIONAL ROLE OF EPIGENETIC CHROMATIN HISTONE H3KME IN TGF-BETA1-MEDIATED ECM GENE EXPRESSION IN MESANGIAL CELLS UNDER NORMAL AND HG CONDITIONS. PHARMACOLOGIC AND OTHER THERAPIES THAT REVERSE THESE MODIFICATIONS COULD HAVE POTENTIAL RENOPROTECTIVE EFFECTS FOR DIABETIC NEPHROPATHY. 2010 2 446 40 APABETALONE DOWNREGULATES FIBROTIC, INFLAMMATORY AND CALCIFIC PROCESSES IN RENAL MESANGIAL CELLS AND PATIENTS WITH RENAL IMPAIRMENT. EPIGENETIC MECHANISMS ARE IMPLICATED IN TRANSCRIPTIONAL PROGRAMS DRIVING CHRONIC KIDNEY DISEASE (CKD). APABETALONE IS AN ORALLY AVAILABLE INHIBITOR OF BROMODOMAIN AND EXTRATERMINAL (BET) PROTEINS, WHICH ARE EPIGENETIC READERS THAT MODULATE GENE EXPRESSION. IN THE PHASE 3 BETONMACE TRIAL, APABETALONE REDUCED RISK OF MAJOR ADVERSE CARDIAC EVENTS (MACE) BY 50% IN THE CKD SUBPOPULATION, INDICATING FAVORABLE EFFECTS ALONG THE KIDNEY-HEART AXIS. ACTIVATION OF HUMAN RENAL MESANGIAL CELLS (HRMCS) TO A CONTRACTILE PHENOTYPE THAT OVERPRODUCES EXTRACELLULAR MATRIX (ECM) AND INFLAMMATORY CYTOKINES, AND PROMOTES CALCIFICATION, FREQUENTLY ACCOMPANIES CKD TO DRIVE PATHOLOGY. HERE, WE SHOW APABETALONE DOWNREGULATED HRMC ACTIVATION WITH TGF-BETA1 STIMULATION BY SUPPRESSING TGF-BETA1-INDUCED ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA) EXPRESSION, ALPHA-SMA ASSEMBLY INTO STRESS FIBERS, ENHANCED CONTRACTION, COLLAGEN OVERPRODUCTION, AND EXPRESSION OF KEY DRIVERS OF FIBROSIS, INFLAMMATION, OR CALCIFICATION INCLUDING THROMBOSPONDIN, FIBRONECTIN, PERIOSTIN, SPARC, INTERLEUKIN 6, AND ALKALINE PHOSPHATASE. LIPOPOLYSACCHARIDE-STIMULATED EXPRESSION OF INFLAMMATORY GENES IL6, IL1B, AND PTGS2 WAS ALSO SUPPRESSED. TRANSCRIPTOMICS CONFIRMED APABETALONE AFFECTED GENE SETS OF ECM REMODELING AND INTEGRINS. CLINICAL TRANSLATION OF IN VITRO RESULTS WAS INDICATED IN CKD PATIENTS WHERE A SINGLE DOSE OF APABETALONE REDUCED PLASMA LEVELS OF KEY PRO-FIBROTIC AND INFLAMMATORY MARKERS, AND INDICATED INHIBITION OF TGF-BETA1 SIGNALING. WHILE PLASMA PROTEINS CANNOT BE TRACED TO THE KIDNEY ALONE, ANTI-FIBROTIC AND ANTI-INFLAMMATORY EFFECTS OF APABETALONE IDENTIFIED IN THIS STUDY ARE CONSISTENT WITH THE OBSERVED DECREASE IN CARDIOVASCULAR RISK IN CKD PATIENTS. 2023 3 542 30 ATP-CITRATE LYASE IS AN EPIGENETIC REGULATOR TO PROMOTE OBESITY-RELATED KIDNEY INJURY. OBESITY IS A LEADING CAUSE OF CHRONIC KIDNEY DISEASE (CKD), BUT HOW OBESITY PROMOTES RENAL INJURY REMAINS POORLY UNDERSTOOD. HERE WE SHOWED THAT ATP-CITRATE LYASE (ACL), AN ENZYME CONVERTING CITRATE TO ACETYL-COA, IS HIGHLY INDUCED IN THE KIDNEY OF OVERWEIGHT OR OBESE PATIENTS WITH CKD AND OB/OB BTBR MICE. ACL INDUCTION IS ASSOCIATED WITH INCREASED ECTOPIC LIPID ACCUMULATION (ELA), GLOMERULOSCLEROSIS, AND ALBUMINURIA. ACETYL-COA IS THE SUBSTRATE FOR DE NOVO LIPOGENESIS AS WELL AS FOR HISTONE ACETYLATION. BY RAISING ACETYL-COA CONCENTRATION ACL PROMOTES H3K9/14 AND H3K27 HYPERACETYLATION LEADING TO UP-REGULATION OF SEVERAL RATE-LIMITING LIPOGENIC ENZYMES AND FIBROGENIC FACTORS. ON THE OTHER HAND, THE EXCESS ACETYL-COA GENERATED AS A RESULT OF ACL INDUCTION PROVIDES THE SUBSTRATE FOR THESE LIPOGENIC ENZYMES TO DRIVE DE NOVO LIPOGENESIS LEADING TO ELA, A DETRIMENTAL EVENT TOWARD RENAL INJURY. IN MESANGIAL CELLS, ACL IS SYNERGISTICALLY INDUCED BY HIGH GLUCOSE, PALMITATE, AND TNF-ALPHA VIA NF-KAPPAB AND PKA PATHWAYS. UNDER THESE CONDITIONS, H3K9/14 AND H3K27 HYPERACETYLATION, AS WELL AS THE INDUCTION OF THE LIPOGENIC AND FIBROGENIC PROTEINS, ARE COMPLETELY BLOCKED IN THE PRESENCE OF AN ACL INHIBITOR. COLLECTIVELY, THESE DATA SUGGEST THAT ACL IS AN EPIGENETIC REGULATOR THAT PROMOTES RENAL ELA AND FIBROGENESIS LEADING TO RENAL INJURY IN OBESITY.-CHEN, Y., DEB, D. K., FU, X., YI, B., LIANG, Y., DU, J., HE, L., LI, Y. C. ATP-CITRATE LYASE IS AN EPIGENETIC REGULATOR TO PROMOTE OBESITY-RELATED KIDNEY INJURY. 2019 4 5363 20 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 5 6075 27 THE DYNAMICS AND PLASTICITY OF EPIGENETICS IN DIABETIC KIDNEY DISEASE: THERAPEUTIC APPLICATIONS VIS-A-VIS. CHRONIC KIDNEY DISEASE (CKD) REFERS TO THE PHENOMENON OF PROGRESSIVE DECLINE IN THE GLOMERULAR FILTRATION RATE ACCOMPANIED BY ADVERSE CONSEQUENCES, INCLUDING FLUID RETENTION, ELECTROLYTE IMBALANCE, AND AN INCREASED CARDIOVASCULAR RISK COMPARED TO THOSE WITH NORMAL RENAL FUNCTION. THE TRIGGERS FOR THE IRREVERSIBLE RENAL FUNCTION DETERIORATION ARE MULTIFACTORIAL, AND DIABETES MELLITUS SERVES AS A MAJOR CONTRIBUTOR TO THE DEVELOPMENT OF CKD, NAMELY DIABETIC KIDNEY DISEASE (DKD). RECENTLY, EPIGENETIC DYSREGULATION EMERGED AS A PIVOTAL PLAYER STEERING THE PROGRESSION OF DKD, PARTLY RESULTING FROM HYPERGLYCEMIA-ASSOCIATED METABOLIC DISTURBANCES, RISING OXIDATIVE STRESS, AND/OR UNCONTROLLED INFLAMMATION. IN THIS REVIEW, WE DESCRIBE THE MAJOR EPIGENETIC MOLECULAR MECHANISMS, FOLLOWED BY SUMMARIZING CURRENT UNDERSTANDINGS OF THE EPIGENETIC ALTERATIONS PERTAINING TO DKD. WE HIGHLIGHT THE EPIGENETIC REGULATORY PROCESSES INVOLVED IN SEVERAL CRUCIAL RENAL CELL TYPES: MESANGIAL CELLS, PODOCYTES, TUBULAR EPITHELIA, AND GLOMERULAR ENDOTHELIAL CELLS. FINALLY, WE HIGHLIGHT EPIGENETIC BIOMARKERS AND RELATED THERAPEUTIC CANDIDATES THAT HOLD PROMISING POTENTIAL FOR THE EARLY DETECTION OF DKD AND THE AMELIORATION OF ITS PROGRESSION. 2022 6 6431 32 THE USE OF TARGETED NEXT GENERATION SEQUENCING TO EXPLORE CANDIDATE REGULATORS OF TGF-BETA1'S IMPACT ON KIDNEY CELLS. AIMS/HYPOTHESIS: TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA1) PLAYS AN IMPORTANT REGULATORY ROLE IN THE PROGRESSION OF CHRONIC KIDNEY FAILURE. FURTHER, DAMAGE TO KIDNEY GLOMERULAR MESANGIAL CELLS IS CENTRAL TO THE PROGRESSION OF DIABETIC NEPHROPATHY. THE AIM OF THIS STUDY WAS TO EXPLORE THE GENETIC ASSOCIATIONS BETWEEN MRNA, MICRORNA, AND EPIGENETICS IN MESANGIAL CELLS IN RESPONSE TO TGF-BETA1. METHODS: THE REGULATORY EFFECTS OF TGF-BETA1 ON MESANGIAL CELLS WERE INVESTIGATED AT DIFFERENT MOLECULAR LEVELS BY TREATING MESANGIAL CELLS WITH TGF-BETA1 FOR 3 DAYS FOLLOWED BY GENOME-WIDE MIRNA, RNA, DNA METHYLATION, AND H3K27ME3 EXPRESSION PROFILING USING NEXT GENERATION SEQUENCING (NGS). RESULTS: OUR RESULTS PROVIDE THE FIRST COMPREHENSIVE, COMPUTATIONALLY INTEGRATED REPORT OF RNA-SEQ, MIRNA-SEQ, AND EPIGENOMIC ANALYSES ACROSS ALL GENETIC VARIATIONS, CONFIRMING THE OCCURRENCE OF DNA METHYLATION AND H3K27ME3 IN RESPONSE TO TGF-BETA1. OUR FINDINGS SHOW THAT THE EXPRESSION OF KLF7 AND GJA4 ARE INVOLVED IN TGF-BETA1 REGULATED DNA METHYLATION. OUR DATA ALSO PROVIDE EVIDENCE OF THE ASSOCIATION BETWEEN EPIGENETIC CHANGES AND THE EXPRESSION OF GENES CLOSELY RELATED TO TGF-BETA1 REGULATION. CONCLUSION: THIS STUDY HAS ADVANCED OUR CURRENT KNOWLEDGE OF MECHANISMS THAT CONTRIBUTE TO THE EXPRESSION OF TGF-BETA1-REGULATED GENES INVOLVED IN THE PATHOGENESIS OF KIDNEY DISEASE. THE MOLECULAR UNDERPINNINGS OF TGF-BETA1 STIMULATION OF KIDNEY CELLS WAS DETERMINED, THEREBY PROVIDING A ROBUST PLATFORM FOR FURTHER TARGET EXPLORATION. 2018 7 6910 25 [TRANSFORMING GROWTH FACTOR-BETA AND RENAL FIBROSIS]. TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) IS A DRIVING FORCE OF RENAL FIBROSIS, WHICH MAY LEAD TO CHRONIC KIDNEY DISEASES AND EVEN END STAGE RENAL DISEASES. BY ACTIVATING CANONICAL AND NON-CANONICAL SIGNALING PATHWAYS, TGF-BETA PROMOTES THE SYNTHESIS OF EXTRACELLULAR MATRIX WHILE PREVENTING THEIR DEGRADATION. IN THE INJURED KIDNEY, TGF-BETA INDUCES APOPTOSIS, PROLIFERATION AND FIBROTIC RESPONSE OF RENAL CELLS INCLUDING EPITHELIAL CELLS, ENDOTHELIAL CELLS, PODOCYTES, FIBROBLASTS, PERICYTES AND MACROPHAGES, AND IT ALSO PROMOTES TRANSDIFFERENTIATION, ACTIVATION AND PROLIFERATION OF MYOFIBROBLASTS. ADDITIONALLY, TGF-BETA EXERTS PROFIBROTIC EFFECTS BY INTERPLAYING WITH OTHER SIGNALING PATHWAYS LIKE BMP-7, WNT/BETA-CATENIN AND MAP KINASE. SMAD3 IS THE CENTRAL PATHOLOGICAL GENE IN RENAL FIBROSIS, AND EPIGENETIC REGULATION OF TGF-BETA/SMAD3 IS A HOT TOPIC IN KIDNEY FIELD. ALTHOUGH DIRECT TARGETING TGF-BETA MAY CAUSE SIDE EFFECTS INCLUDING TUMORIGENESIS AND IMMUNE DISEASES, THE THERAPEUTIC STRATEGIES TARGETING THE BALANCE OF DOWNSTREAM SMAD3 AND SMAD7 MAY PREVENT OR DELAY THE PROGRESSION OF FIBROTIC KIDNEY DISEASE. 2018 8 5994 39 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 9 5988 30 TGF-BETA/SMAD AND RENAL FIBROSIS. RENAL FIBROSIS IS CHARACTERIZED BY EXCESSIVE DEPOSITION OF EXTRACELLULAR MATRIX (ECM) THAT DISRUPTS AND REPLACES FUNCTIONAL PARENCHYMA, WHICH LEADS TO ORGAN FAILURE. IT IS KNOWN AS THE MAJOR PATHOLOGICAL MECHANISM OF CHRONIC KIDNEY DISEASE (CKD). ALTHOUGH CKD HAS AN IMPACT ON NO LESS THAN 10% OF THE WORLD POPULATION, THERAPEUTIC OPTIONS ARE STILL LIMITED. REGARDLESS OF ETIOLOGY, ELEVATED TGF-BETA LEVELS ARE HIGHLY CORRELATED WITH THE ACTIVATED PRO-FIBROTIC PATHWAYS AND DISEASE PROGRESSION. TGF-BETA, THE KEY DRIVER OF RENAL FIBROSIS, IS INVOLVED IN A DYNAMIC PATHOPHYSIOLOGICAL PROCESS THAT LEADS TO CKD AND END-STAGE RENAL DISEASE (ESRD). IT IS BECOMING CLEAR THAT EPIGENETICS REGULATES RENAL PROGRAMMING, AND THEREFORE, THE DEVELOPMENT AND PROGRESSION OF RENAL DISEASE. INDEED, RECENT EVIDENCE SHOWS TGF-BETA1/SMAD SIGNALING REGULATES RENAL FIBROSIS VIA EPIGENETIC-CORRELATED MECHANISMS. THIS REVIEW FOCUSES ON THE FUNCTION OF TGF-BETA/SMADS IN RENAL FIBROGENESIS, AND THE ROLE OF EPIGENETICS AS A REGULATOR OF PRO-FIBROTIC GENE EXPRESSION. 2019 10 1665 40 DOWNREGULATION OF KIDNEY PROTECTIVE FACTORS BY INFLAMMATION: ROLE OF TRANSCRIPTION FACTORS AND EPIGENETIC MECHANISMS. CHRONIC KIDNEY DISEASE (CKD) IS ASSOCIATED TO AN INCREASED RISK OF DEATH, CKD PROGRESSION, AND ACUTE KIDNEY INJURY (AKI) EVEN FROM EARLY STAGES, WHEN GLOMERULAR FILTRATION RATE (GFR) IS PRESERVED. THE LINK BETWEEN EARLY CKD AND THESE RISKS IS UNCLEAR, SINCE THERE IS NO ACCUMULATION OF UREMIC TOXINS. HOWEVER, PATHOLOGICAL ALBUMINURIA AND KIDNEY INFLAMMATION ARE FREQUENT FEATURES OF EARLY CKD, AND THE PRODUCTION OF KIDNEY PROTECTIVE FACTORS MAY BE DECREASED. INDEED, KLOTHO EXPRESSION IS ALREADY DECREASED IN CKD CATEGORY G1 (NORMAL GFR). KLOTHO HAS ANTI-AGING AND NEPHROPROTECTIVE PROPERTIES, AND DECREASED KLOTHO LEVELS MAY CONTRIBUTE TO INCREASE THE RISK OF DEATH, CKD PROGRESSION, AND AKI. IN THIS REVIEW, WE DISCUSS THE DOWNREGULATION BY MEDIATORS OF INFLAMMATION OF MOLECULES WITH SYSTEMIC AND/OR RENAL LOCAL PROTECTIVE FUNCTIONS, EXEMPLIFIED BY KLOTHO AND PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA COACTIVATOR-1ALPHA (PGC-1ALPHA), A TRANSCRIPTION FACTOR THAT PROMOTES MITOCHONDRIAL BIOGENESIS. CYTOKINES SUCH AS TWEAK, TNF-ALPHA, OR TRANSFORMING GROWTH FACTOR -BETA1 PRODUCED LOCALLY DURING KIDNEY INJURY OR RELEASED FROM INFLAMMATORY SITES AT OTHER ORGANS MAY DECREASE KIDNEY EXPRESSION OF KLOTHO AND PGC-1ALPHA OR LEAD TO SUBOPTIMAL RECRUITMENT OF THESE NEPHROPROTECTIVE PROTEINS. TRANSCRIPTION FACTORS (E.G., SMAD3 AND NF-KAPPAB) AND EPIGENETIC MECHANISMS (E.G., HISTONE ACETYLATION OR METHYLATION) CONTRIBUTE TO DOWNREGULATE THE EXPRESSION OF KLOTHO AND/OR PGC-1ALPHA, WHILE HISTONE CROTONYLATION PROMOTES PGC-1ALPHA EXPRESSION. NF-KAPPABIZ FACILITATES THE REPRESSIVE EFFECT OF NF-KAPPAB ON KLOTHO EXPRESSION. A DETAILED UNDERSTANDING OF THESE MEDIATORS MAY CONTRIBUTE TO THE DEVELOPMENT OF NOVEL THERAPEUTIC APPROACHES TO PREVENT CKD PROGRESSION AND ITS NEGATIVE IMPACT ON MORTALITY AND AKI. 2016 11 364 31 AMELIORATION OF UREMIC TOXIN INDOXYL SULFATE-INDUCED OSTEOBLASTIC CALCIFICATION BY SET DOMAIN CONTAINING LYSINE METHYLTRANSFERASE 7/9 PROTEIN. BACKGROUND: VASCULAR CALCIFICATION (VC) IS A VERY COMMON PHENOMENON IN PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD). IT HAS BEEN REPORTED THAT SOME HISTONE METHYLATION PLAY A ROLE IN VC AS AN EPIGENETIC REGULATOR. INDOXYL SULFATE (IS) IS A PROTEIN-BOUND UREMIC TOXIN THAT HAS BEEN PROVEN AS ONE OF THE MAJOR RISK FACTORS OF CARDIOVASCULAR DISEASE IN CKD. SET DOMAIN CONTAINING LYSINE METHYLTRANSFERASE 7/9 (SET7/9) IS ONE OF THE IMPORTANT HISTONE METHYLTRANSFERASES. OBJECTIVES: THIS STUDY AIMED TO DETERMINE THE EFFECT OF IS ON THE EXPRESSION OF SET7/9 AND THE ROLE OF SET7/9 IN IS-INDUCED OSTEOBLASTIC DIFFERENTIATION AND CALCIFICATION OF VASCULAR SMOOTH MUSCLE CELLS (VSMCS). METHODS: VSMCS WERE INCUBATED WITH VARIOUS CONCENTRATIONS OF IS FOR DIFFERENT DURATIONS TO ASSESS OSTEOBLASTIC DIFFERENTIATION AND EXPRESSION OF SET7/9. WESTERN BLOT ANALYSIS AND QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION WERE PERFORMED TO ASSESS THE PROTEIN AND MRNA LEVELS OF SET7/9 RESPECTIVELY. THE CALCIUM CONTENT WAS MEASURED TO EVALUATE CALCIFICATION. RESULTS: OSTEOBLASTIC DIFFERENTIATION AND CALCIFICATION OF VSMCS AND DOWNREGULATION OF THE EXPRESSION OF SET7/9 WERE OBSERVED AFTER IS TREATMENT. THE AUTOPHAGY WAS ACTIVATED AFTER TREATMENT WITH IS, WHEREAS THE INHIBITION OF THE AUTOPHAGY PARTIALLY ATTENUATED THE EFFECT OF IS ON BOTH THE STIMULATION OF THE EXPRESSION OF RUNT-RELATED TRANSCRIPTION FACTOR 2 AND CALCIUM DEPOSITION. CONCLUSIONS: OUR DATA DEMONSTRATED THAT SET7/9 DOWNREGULATION AND AUTOPHAGY ACTIVATION MAY BE THE KEY MECHANISM OF IS-INDUCED VC IN CKD. 2019 12 5571 45 ROLE OF MICRORNA 1207-5P AND ITS HOST GENE, THE LONG NON-CODING RNA PVT1, AS MEDIATORS OF EXTRACELLULAR MATRIX ACCUMULATION IN THE KIDNEY: IMPLICATIONS FOR DIABETIC NEPHROPATHY. DIABETIC NEPHROPATHY IS THE MOST COMMON CAUSE OF CHRONIC KIDNEY FAILURE AND END-STAGE RENAL DISEASE IN THE WESTERN WORLD. ONE OF THE MAJOR CHARACTERISTICS OF THIS DISEASE IS THE EXCESSIVE ACCUMULATION OF EXTRACELLULAR MATRIX (ECM) IN THE KIDNEY GLOMERULI. WHILE BOTH ENVIRONMENTAL AND GENETIC DETERMINANTS ARE RECOGNIZED FOR THEIR ROLE IN THE DEVELOPMENT OF DIABETIC NEPHROPATHY, EPIGENETIC FACTORS, SUCH AS DNA METHYLATION, LONG NON-CODING RNAS, AND MICRORNAS, HAVE ALSO RECENTLY BEEN FOUND TO UNDERLIE SOME OF THE BIOLOGICAL MECHANISMS, INCLUDING ECM ACCUMULATION, LEADING TO THE DISEASE. WE PREVIOUSLY FOUND THAT A LONG NON-CODING RNA, THE PLASMACYTOMA VARIANT TRANSLOCATION 1 (PVT1), INCREASES PLASMINOGEN ACTIVATOR INHIBITOR 1 (PAI-1) AND TRANSFORMING GROWTH FACTOR BETA 1 (TGF-BETA1) IN MESANGIAL CELLS, THE TWO MAIN CONTRIBUTORS TO ECM ACCUMULATION IN THE GLOMERULI UNDER HYPERGLYCEMIC CONDITIONS, AS WELL AS FIBRONECTIN 1 (FN1), A MAJOR ECM COMPONENT. HERE, WE REPORT THAT MIR-1207-5P, A PVT1-DERIVED MICRORNA, IS ABUNDANTLY EXPRESSED IN KIDNEY CELLS, AND IS UPREGULATED BY GLUCOSE AND TGF-BETA1. WE ALSO FOUND THAT LIKE PVT1, MIR-1207-5P INCREASES EXPRESSION OF TGF-BETA1, PAI-1, AND FN1 BUT IN A MANNER THAT IS INDEPENDENT OF ITS HOST GENE. IN ADDITION, REGULATION OF MIR-1207-5P EXPRESSION BY GLUCOSE AND TGFBETA1 IS INDEPENDENT OF PVT1. THESE RESULTS PROVIDE EVIDENCE SUPPORTING IMPORTANT ROLES FOR MIR-1207-5P AND ITS HOST GENE IN THE COMPLEX PATHOGENESIS OF DIABETIC NEPHROPATHY. 2013 13 4137 33 MECHANISMS OF METABOLIC MEMORY AND RENAL HYPOXIA AS A THERAPEUTIC TARGET IN DIABETIC KIDNEY DISEASE. DIABETIC KIDNEY DISEASE (DKD) IS A WORLDWIDE PUBLIC HEALTH PROBLEM. THE DEFINITION OF DKD IS UNDER DISCUSSION. ALTHOUGH THE TERM DKD WAS ORIGINALLY DEFINED AS 'KIDNEY DISEASE SPECIFIC TO DIABETES,' DKD FREQUENTLY MEANS CHRONIC KIDNEY DISEASE WITH DIABETES MELLITUS AND INCLUDES NOT ONLY CLASSICAL DIABETIC NEPHROPATHY, BUT ALSO KIDNEY DYSFUNCTION AS A RESULT OF NEPHROSCLEROSIS AND OTHER CAUSES. METABOLIC MEMORY PLAYS A CRUCIAL ROLE IN THE PROGRESSION OF VARIOUS COMPLICATIONS OF DIABETES, INCLUDING DKD. THE MECHANISMS OF METABOLIC MEMORY IN DKD ARE SUPPOSED TO INCLUDE ADVANCED GLYCATION END-PRODUCTS, DEOXYRIBONUCLEIC ACID METHYLATION, HISTONE MODIFICATIONS AND NON-CODING RIBONUCLEIC ACID INCLUDING MICRO RIBONUCLEIC ACID. REGARDLESS OF THE PRESENCE OF DIABETES MELLITUS, THE FINAL COMMON PATHWAY IN CHRONIC KIDNEY DISEASE IS CHRONIC KIDNEY HYPOXIA, WHICH INFLUENCES EPIGENETIC PROCESSES, INCLUDING DEOXYRIBONUCLEIC ACID METHYLATION, HISTONE MODIFICATION, AND CONFORMATIONAL CHANGES IN MICRO RIBONUCLEIC ACID AND CHROMATIN. THEREFORE, HYPOXIA AND OXIDATIVE STRESS ARE APPROPRIATE TARGETS OF THERAPIES AGAINST DKD. PROLYL HYDROXYLASE DOMAIN INHIBITOR ENHANCES THE DEFENSIVE MECHANISMS AGAINST HYPOXIA. BARDOXOLONE METHYL PROTECTS AGAINST OXIDATIVE STRESS, AND CAN EVEN REVERSE IMPAIRED RENAL FUNCTION; A PHASE 2 TRIAL WITH CONSIDERABLE ATTENTION TO HEART COMPLICATIONS IS CURRENTLY ONGOING IN JAPAN. 2017 14 6638 29 UNRAVELING THE EPIGENETIC LANDSCAPE OF GLOMERULAR CELLS IN KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS A MAJOR PUBLIC HEALTH CONCERN AND ITS PREVALENCE AND INCIDENCE ARE RISING QUICKLY. IT IS A NON-COMMUNICABLE DISEASE PRIMARILY CAUSED BY DIABETES AND/OR HYPERTENSION AND IS ASSOCIATED WITH HIGH MORBIDITY AND MORTALITY. DESPITE DECADES OF RESEARCH EFFORTS, THE PATHOGENESIS OF CKD REMAINS A PUZZLE WITH MISSING PIECES. UNDERSTANDING THE CELLULAR AND MOLECULAR MECHANISMS THAT GOVERN THE LOSS OF KIDNEY FUNCTION IS CRUCIAL. ABRUPT REGULATION OF GENE EXPRESSION IN KIDNEY CELLS IS APPARENT IN CKD AND SHOWN TO BE RESPONSIBLE FOR DISEASE ONSET AND PROGRESSION. GENE EXPRESSION REGULATION EXTENDS BEYOND DNA SEQUENCE AND INVOLVES EPIGENETIC MECHANISMS INCLUDING CHANGES IN DNA METHYLATION AND POST-TRANSLATIONAL MODIFICATIONS OF HISTONES, DRIVEN BY THE ACTIVITY OF SPECIFIC ENZYMES. RECENT ADVANCES DEMONSTRATE THE ESSENTIAL PARTICIPATION OF EPIGENETICS IN KIDNEY (PATHO)PHYSIOLOGY, AS ITS ACTIONS REGULATE BOTH THE INTEGRITY OF CELLS BUT ALSO TRIGGERS DELETERIOUS SIGNALING PATHWAYS. HERE, WE REVIEW THE KNOWN EPIGENETIC PROCESSES REGULATING THE COMPLEX FILTRATION UNIT OF THE KIDNEY, THE GLOMERULI. THE REVIEW WILL ELABORATE ON NOVEL INSIGHTS INTO HOW EPIGENETICS CONTRIBUTES TO CELL INJURY IN THE CKD SETTING MAJORLY FOCUSING ON KIDNEY GLOMERULAR CELLS: THE GLOMERULAR ENDOTHELIAL CELLS, THE MESANGIAL CELLS, AND THE SPECIALIZED AND TERMINALLY DIFFERENTIATED PODOCYTE CELLS. 2021 15 3466 23 HYPOXIA AS A KEY PLAYER IN THE AKI-TO-CKD TRANSITION. RECENT CLINICAL AND ANIMAL STUDIES HAVE SHOWN THAT ACUTE KIDNEY INJURY (AKI), EVEN IF FOLLOWED BY COMPLETE RECOVERY OF RENAL FUNCTION, CAN EVENTUALLY RESULT IN CHRONIC KIDNEY DISEASE (CKD). RENAL HYPOXIA IS EMERGING AS A KEY PLAYER IN THE PATHOPHYSIOLOGY OF THE AKI-TO-CKD TRANSITION. CAPILLARY RAREFACTION AFTER AKI EPISODES INDUCES RENAL HYPOXIA, WHICH CAN IN TURN PROFOUNDLY AFFECT TUBULAR EPITHELIAL CELLS, (MYO)FIBROBLASTS, AND INFLAMMATORY CELLS, CULMINATING IN TUBULOINTERSTITIAL FIBROSIS, I.E., PROGRESSION TO CKD. DAMAGED TUBULAR EPITHELIAL CELLS THAT FAIL TO REDIFFERENTIATE MIGHT SUPPLY A DECREASED AMOUNT OF VASCULAR ENDOTHELIAL GROWTH FACTOR AND CONTRIBUTE TO CAPILLARY RAREFACTION, THUS AGGRAVATING HYPOXIA AND FORMING A VICIOUS CYCLE. MOUNTING EVIDENCE ALSO SHOWS THAT EPIGENETIC CHANGES ARE CLOSELY RELATED TO RENAL HYPOXIA IN THE PATHOPHYSIOLOGY OF CKD PROGRESSION. ANIMAL EXPERIMENTS SUGGEST THAT TARGETING HYPOXIA IS A PROMISING STRATEGY TO BLOCK THE TRANSITION FROM AKI TO CKD. HOWEVER, THE PRECISE MECHANISMS BY WHICH HYPOXIA INDUCES THE AKI-TO-CKD TRANSITION AND BY WHICH HYPOXIA-INDUCIBLE FACTOR ACTIVATION CAN EXERT A PROTECTIVE EFFECT IN THIS CONTEXT SHOULD BE CLARIFIED IN FURTHER STUDIES. 2014 16 6648 28 UPDATE ON DIAGNOSIS, PATHOPHYSIOLOGY, AND MANAGEMENT OF DIABETIC KIDNEY DISEASE. DIABETIC KIDNEY DISEASE (DKD) IS A CHRONIC COMPLICATION OF DIABETES MELLITUS WHICH MAY EVENTUALLY LEAD TO END-STAGE KIDNEY DISEASE (ESKD). DESPITE IMPROVEMENTS IN GLYCAEMIC CONTROL AND BLOOD PRESSURE MANAGEMENT WITH RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM (RAAS) BLOCKADE, THE CURRENT THERAPY CANNOT COMPLETELY HALT DKD PROGRESSION TO ESKD IN SOME PATIENTS. DKD IS A HETEROGENEOUS DISEASE ENTITY IN TERMS OF ITS CLINICAL MANIFESTATIONS, HISTOPATHOLOGY AND THE RATE OF PROGRESSION, WHICH MAKES IT DIFFICULT TO DEVELOP EFFECTIVE THERAPEUTICS. IT WAS FORMERLY CONSIDERED THAT ALBUMINURIA PRECEDED KIDNEY FUNCTION DECLINE IN DKD, BUT RECENT EPIDEMIOLOGICAL STUDIES REVEALED THAT A DISTINCT GROUP OF PATIENTS PRESENTED KIDNEY DYSFUNCTION WITHOUT DEVELOPING ALBUMINURIA. OTHER COMORBIDITIES, SUCH AS HYPERTENSION, OBESITY AND GOUT, ALSO AFFECT THE CLINICAL COURSE OF DKD. THE PATHOPHYSIOLOGY OF DKD IS COMPLEX AND MULTIFACTORIAL, INVOLVING BOTH METABOLIC AND HAEMODYNAMIC FACTORS. THESE INDUCE ACTIVATION OF INTRACELLULAR SIGNALLING PATHWAYS, OXIDATIVE STRESS, HYPOXIA, DYSREGULATED AUTOPHAGY AND EPIGENETIC CHANGES, WHICH RESULT IN KIDNEY INFLAMMATION AND FIBROSIS. RECENTLY, TWO GROUPS OF ANTIDIABETIC DRUGS, SODIUM-GLUCOSE COTRANSPORTER 2 (SGLT2) INHIBITORS AND GLUCAGON-LIKE PEPTIDE-1 (GLP-1) RECEPTOR AGONISTS, WERE DEMONSTRATED TO PROVIDE RENOPROTECTION ON TOP OF THEIR GLUCOSE-LOWERING EFFECTS. SEVERAL OTHER THERAPEUTIC AGENTS ARE ALSO BEING DEVELOPED AND EVALUATED IN CLINICAL TRIALS. 2021 17 1983 33 EPIGENETIC ALTERATIONS IN PODOCYTES IN DIABETIC NEPHROPATHY. RECENTLY, EPIGENETIC ALTERATIONS HAVE BEEN SHOWN TO BE INVOLVED IN THE PATHOGENESIS OF DIABETES AND ITS COMPLICATIONS. KIDNEY PODOCYTES, WHICH ARE GLOMERULAR EPITHELIAL CELLS, ARE IMPORTANT CELLS THAT FORM A SLIT MEMBRANE-A BARRIER FOR PROTEINURIA. PODOCYTES ARE TERMINALLY DIFFERENTIATED CELLS WITHOUT CELL DIVISION OR REPLENISHMENT ABILITIES. THEREFORE, PODOCYTE DAMAGE IS SUGGESTED TO BE ONE OF THE KEY FACTORS DETERMINING RENAL PROGNOSIS. RECENT STUDIES, INCLUDING OURS, SUGGEST THAT EPIGENETIC CHANGES IN PODOCYTES ARE ASSOCIATED WITH CHRONIC KIDNEY DISEASE, INCLUDING DIABETIC NEPHROPATHY. FURTHERMORE, THE ASSOCIATION BETWEEN DNA DAMAGE REPAIR AND EPIGENETIC CHANGES IN DIABETIC PODOCYTES HAS BEEN DEMONSTRATED. DETECTION OF PODOCYTE DNA DAMAGE AND EPIGENETIC CHANGES USING HUMAN SAMPLES, SUCH AS KIDNEY BIOPSY AND URINE-DERIVED CELLS, MAY BE A PROMISING STRATEGY FOR ESTIMATING KIDNEY DAMAGE AND RENAL PROGNOSES IN PATIENTS WITH DIABETES. TARGETING EPIGENETIC PODOCYTE CHANGES AND ASSOCIATED DNA DAMAGE MAY BECOME A NOVEL THERAPEUTIC STRATEGY FOR PREVENTING PROGRESSION TO END-STAGE RENAL DISEASE (ESRD) AND PROVIDE A POSSIBLE PROGNOSTIC MARKER IN DIABETIC NEPHROPATHY. THIS REVIEW SUMMARIZES RECENT ADVANCES REGARDING EPIGENETIC CHANGES, ESPECIALLY DNA METHYLATION, IN PODOCYTES IN DIABETIC NEPHROPATHY AND ADDRESSES DETECTION OF THESE ALTERATIONS IN HUMAN SAMPLES. ADDITIONALLY, WE FOCUSED ON DNA DAMAGE, WHICH IS INCREASED UNDER HIGH-GLUCOSE CONDITIONS AND ASSOCIATED WITH THE GENERATION OF EPIGENETIC CHANGES IN PODOCYTES. FURTHERMORE, EPIGENETIC MEMORY IN DIABETES IS DISCUSSED. UNDERSTANDING THE ROLE OF EPIGENETIC CHANGES IN PODOCYTES IN DIABETIC NEPHROPATHY MAY BE OF GREAT IMPORTANCE CONSIDERING THE INCREASING DIABETIC NEPHROPATHY PATIENT POPULATION IN AN AGING SOCIETY. 2021 18 6575 32 TREATMENT OF DIABETIC KIDNEY DISEASE: CURRENT AND FUTURE. DIABETIC KIDNEY DISEASE (DKD) IS THE MAJOR CAUSE OF END-STAGE KIDNEY DISEASE. HOWEVER, ONLY RENIN-ANGIOTENSIN SYSTEM INHIBITOR WITH MULTIDISCIPLINARY TREATMENTS IS EFFECTIVE FOR DKD. IN 2019, SODIUM-GLUCOSE COTRANSPORTER 2 (SGLT2) INHIBITOR SHOWED EFFICACY AGAINST DKD IN CANAGLIFLOZIN AND RENAL EVENTS IN DIABETES WITH ESTABLISHED NEPHROPATHY CLINICAL EVALUATION (CREDENCE) TRIAL, ADDING A NEW TREATMENT OPTION. HOWEVER, THE PROGRESSION OF DKD HAS NOT BEEN COMPLETELY CONTROLLED. THE PATIENTS WITH TRANSIENT EXPOSURE TO HYPERGLYCEMIA DEVELOP DIABETIC COMPLICATIONS, INCLUDING DKD, EVEN AFTER NORMALIZATION OF THEIR BLOOD GLUCOSE. TEMPORARY HYPERGLYCEMIA CAUSES ADVANCED GLYCATION END PRODUCT (AGE) ACCUMULATIONS AND EPIGENETIC CHANGES AS METABOLIC MEMORY. THE DRUGS THAT IMPROVE METABOLIC MEMORY ARE AWAITED, AND AGE INHIBITORS AND HISTONE MODIFICATION INHIBITORS ARE THE FOCUS OF CLINICAL AND BASIC RESEARCH. IN ADDITION, INCRETIN-RELATED DRUGS SHOWED A RENOPROTECTIVE ABILITY IN MANY CLINICAL TRIALS, AND THESE TRIALS WITH RENAL OUTCOME AS THEIR PRIMARY ENDPOINT ARE CURRENTLY ONGOING. HYPOXIA-INDUCIBLE FACTOR PROLYL HYDROXYLASE INHIBITORS RECENTLY APPROVED FOR RENAL ANEMIA MAY BE RENOPROTECTIVE SINCE THEY IMPROVE TUBULOINTERSTITIAL HYPOXIA. FURTHERMORE, NF-E2-RELATED FACTOR 2 ACTIVATORS IMPROVED THE GLOMERULAR FILTRATION RATE OF DKD PATIENTS IN BARDOXOLONE METHYL TREATMENT: RENAL FUNCTION IN CHRONIC KIDNEY DISEASE/TYPE 2 DIABETES (BEAM) TRIAL AND PHASE II STUDY OF BARDOXOLONE METHYL IN PATIENTS WITH CHRONIC KIDNEY DISEASE AND TYPE 2 DIABETES (TSUBAKI) TRIAL. THUS, FOLLOWING SGLT2 INHIBITOR, NUMEROUS NOVEL DRUGS COULD BE UTILIZED IN TREATING DKD. FUTURE STUDIES ARE EXPECTED TO PROVIDE NEW INSIGHTS. 2021 19 5370 18 RECENT ADVANCES IN UNDERSTANDING OF CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS DEFINED AS ANY CONDITION THAT CAUSES REDUCED KIDNEY FUNCTION OVER A PERIOD OF TIME. FIBROSIS, TUBULAR ATROPHY AND INTERSTITIAL INFLAMMATION ARE THE HALLMARK OF PATHOLOGICAL FEATURES IN CKD. REGARDLESS OF INITIAL INSULT, CKD HAS SOME COMMON PATHWAYS LEADING CKD TO END-STAGE KIDNEY DISEASE, INCLUDING HYPOXIA IN THE TUBULOINTERSTITIUM AND PROTEINURIA. RECENT ADVANCES IN GENOME EDITING TECHNOLOGIES AND STEM CELL RESEARCH GIVE GREAT INSIGHTS TO UNDERSTAND THE PATHOGENESIS OF CKD, INCLUDING IDENTIFICATIONS OF THE ORIGINS OF RENAL MYOFIBROBLASTS AND TUBULAR EPITHELIAL CELLS UPON INJURY. ENVIRONMENTAL FACTORS SUCH AS HYPOXIA, OXIDATIVE STRESS, AND EPIGENETIC FACTORS IN RELATION TO CKD ARE ALSO DISCUSSED. 2015 20 5992 30 TGF-BETA: THE MASTER REGULATOR OF FIBROSIS. TRANSFORMING GROWTH FACTOR-BETA (TGF-BETA) IS THE PRIMARY FACTOR THAT DRIVES FIBROSIS IN MOST, IF NOT ALL, FORMS OF CHRONIC KIDNEY DISEASE (CKD). INHIBITION OF THE TGF-BETA ISOFORM, TGF-BETA1, OR ITS DOWNSTREAM SIGNALLING PATHWAYS SUBSTANTIALLY LIMITS RENAL FIBROSIS IN A WIDE RANGE OF DISEASE MODELS WHEREAS OVEREXPRESSION OF TGF-BETA1 INDUCES RENAL FIBROSIS. TGF-BETA1 CAN INDUCE RENAL FIBROSIS VIA ACTIVATION OF BOTH CANONICAL (SMAD-BASED) AND NON-CANONICAL (NON-SMAD-BASED) SIGNALLING PATHWAYS, WHICH RESULT IN ACTIVATION OF MYOFIBROBLASTS, EXCESSIVE PRODUCTION OF EXTRACELLULAR MATRIX (ECM) AND INHIBITION OF ECM DEGRADATION. THE ROLE OF SMAD PROTEINS IN THE REGULATION OF FIBROSIS IS COMPLEX, WITH COMPETING PROFIBROTIC AND ANTIFIBROTIC ACTIONS (INCLUDING IN THE REGULATION OF MESENCHYMAL TRANSITIONING), AND WITH COMPLEX INTERPLAY BETWEEN TGF-BETA/SMADS AND OTHER SIGNALLING PATHWAYS. STUDIES OVER THE PAST 5 YEARS HAVE IDENTIFIED ADDITIONAL MECHANISMS THAT REGULATE THE ACTION OF TGF-BETA1/SMAD SIGNALLING IN FIBROSIS, INCLUDING SHORT AND LONG NONCODING RNA MOLECULES AND EPIGENETIC MODIFICATIONS OF DNA AND HISTONE PROTEINS. ALTHOUGH DIRECT TARGETING OF TGF-BETA1 IS UNLIKELY TO YIELD A VIABLE ANTIFIBROTIC THERAPY DUE TO THE INVOLVEMENT OF TGF-BETA1 IN OTHER PROCESSES, GREATER UNDERSTANDING OF THE VARIOUS PATHWAYS BY WHICH TGF-BETA1 CONTROLS FIBROSIS HAS IDENTIFIED ALTERNATIVE TARGETS FOR THE DEVELOPMENT OF NOVEL THERAPEUTICS TO HALT THIS MOST DAMAGING PROCESS IN CKD. 2016