1 6075 114 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 2 1832 41 EFFECTS OF METABOLIC MEMORY ON INFLAMMATION AND FIBROSIS ASSOCIATED WITH DIABETIC KIDNEY DISEASE: AN EPIGENETIC PERSPECTIVE. DIABETIC KIDNEY DISEASE (DKD) IS ONE OF THE MOST COMMON MICROVASCULAR COMPLICATION OF BOTH TYPE 1 (T1DM) AND TYPE 2 DIABETES MELLITUS (T2DM), AND THE LEADING CAUSE OF END-STAGE RENAL DISEASE (ESRD) WORLDWIDE. PERSISTENT INFLAMMATION AND SUBSEQUENT CHRONIC FIBROSIS ARE MAJOR CAUSES OF LOSS OF RENAL FUNCTION, WHICH IS ASSOCIATED WITH THE PROGRESSION OF DKD TO ESRD. IN FACT, DKD PROGRESSION IS AFFECTED BY A COMBINATION OF GENETIC AND ENVIRONMENTAL FACTORS. APPROXIMATELY, ONE-THIRD OF DIABETIC PATIENTS PROGRESS TO DEVELOP DKD DESPITE INTENSIVE GLYCEMIC CONTROL, WHICH PROPOSE AN ESSENTIAL CONCEPT "METABOLIC MEMORY." EPIGENETIC MODIFICATIONS, AN EXTENSIVELY STUDIED MECHANISM OF METABOLIC MEMORY, HAVE BEEN SHOWN TO CONTRIBUTE TO THE SUSCEPTIBILITY TO DEVELOP DKD. EPIGENETIC MODIFICATIONS ALSO PLAY A REGULATORY ROLE IN THE INTERACTIONS BETWEEN THE GENES AND THE ENVIRONMENTAL FACTORS. THE EPIGENETIC CONTRIBUTIONS TO THE PROCESSES OF INFLAMMATION AND FIBROGENESIS INVOLVED IN DKD OCCUR AT DIFFERENT REGULATORY LEVELS, INCLUDING DNA METHYLATION, HISTONE MODIFICATION AND NON-CODING RNA MODULATION. COMPARED WITH GENETIC FACTORS, EPIGENETICS REPRESENTS A NEW THERAPEUTIC FRONTIER IN UNDERSTANDING THE DEVELOPMENT DKD AND MAY LEAD TO THERAPEUTIC BREAKTHROUGHS DUE TO THE POSSIBILITY TO REVERSE THESE MODIFICATIONS THERAPEUTICALLY. EARLY RECOGNITION OF EPIGENETIC EVENTS AND BIOMARKERS IS CRUCIAL FOR TIMELY DIAGNOSIS AND INTERVENTION OF DKD, AND FOR THE PREVENTION OF THE PROGRESSION OF DKD TO ESRD. HEREIN, WE WILL REVIEW THE LATEST EPIGENETIC MECHANISMS INVOLVED IN THE RENAL PATHOLOGY OF BOTH TYPE 1 (T1DN) AND TYPE 2 DIABETIC NEPHROPATHY (T2DN) AND HIGHLIGHT THE EMERGING ROLE AND POSSIBLE THERAPEUTIC STRATEGIES BASED ON THE UNDERSTANDING OF THE ROLE OF EPIGENETICS IN DKD-ASSOCIATED INFLAMMATION AND FIBROGENESIS. 2021 3 6638 42 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 4 2579 26 EPIGENETICS OF KIDNEY DISEASE. DNA METHYLATION AND HISTONE MODIFICATIONS DETERMINE RENAL PROGRAMMING AND THE DEVELOPMENT AND PROGRESSION OF RENAL DISEASE. THE IDENTIFICATION OF THE WAY IN WHICH THE RENAL CELL EPIGENOME IS ALTERED BY ENVIRONMENTAL MODIFIERS DRIVING THE ONSET AND PROGRESSION OF RENAL DISEASES HAS EXTENDED OUR UNDERSTANDING OF THE PATHOPHYSIOLOGY OF KIDNEY DISEASE PROGRESSION. IN THIS REVIEW, WE FOCUS ON CURRENT KNOWLEDGE CONCERNING THE IMPLICATIONS OF EPIGENETIC MODIFICATIONS DURING RENAL DISEASE FROM EARLY DEVELOPMENT TO CHRONIC KIDNEY DISEASE PROGRESSION INCLUDING RENAL FIBROSIS, DIABETIC NEPHROPATHY AND THE TRANSLATIONAL POTENTIAL OF IDENTIFYING NEW BIOMARKERS AND TREATMENTS FOR THE PREVENTION AND THERAPY OF CHRONIC KIDNEY DISEASE AND END-STAGE KIDNEY DISEASE. 2017 5 2121 38 EPIGENETIC HISTONE MODIFICATIONS IN THE PATHOGENESIS OF DIABETIC KIDNEY DISEASE. DIABETIC KIDNEY DISEASE (DKD), AS THE MAIN COMPLICATION OF DIABETES MELLITUS, IS THE PRIMARY CAUSE OF THE END-STAGE RENAL DISEASE (ESRD) AND THE MOST COMMON CHRONIC KIDNEY DISEASE. OVERALL, 30-40% OF PATIENTS WITH TYPE 1 AND TYPE 2 DIABETES EVENTUALLY DEVELOP DKD. ALTHOUGH SOME DIABETES PATIENTS HAVE INTENSIFIED GLYCEMIC CONTROL, THEY STILL DEVELOP DIABETIC KIDNEY DISEASE. CURRENT TREATMENT METHODS CAN ALLEVIATE BUT DO NOT MARKEDLY HALT DISEASE DEVELOPMENT, RESULTING IN RENAL FAILURE AND SEVERE COMPLICATIONS, EVEN CONTRIBUTING TO ELEVATED MORBIDITY AND MORTALITY RATES. DKD IS A DISEASE WITH INTERACTIONS OF GENES AND THE ENVIRONMENT. EMERGING EVIDENCE INDICATES THAT DKD-ASSOCIATED KEY GENES ARE ALSO REGULATED BY THE EPIGENETIC MECHANISM. RECENTLY, INCREASING RESEARCHES INVOLVING CELLS AND EXPERIMENTAL ANIMALS DEMONSTRATED THAT HISTONE POST-TRANSLATIONAL MODIFICATIONS CAN MEDIATE GENE EXPRESSION, WHICH CORRELATED WITH DIABETIC KIDNEY DISEASE. NOVEL THERAPEUTIC STRATEGIES FOR EPIGENETIC EVENTS COULD BE BENEFICIAL FOR THE EARLY DETECTION AND TREATMENT OF DKD TO PREVENT IT FROM DEVELOPING INTO END-STAGE RENAL DISEASE (ESRD). IN THIS REVIEW, WE DISCUSS PRIOR FINDINGS IN THE FIELD OF HISTONE MODIFICATIONS IN DKD, ESPECIALLY HISTONE ACETYLATION AND HISTONE METHYLATION. WE THEN FOCUS ON RECENT DEVELOPMENTS IN HISTONE ACETYLATION AND METHYLATION INVOLVED IN THE PATHOGENESIS OF DKD. 2021 6 2195 32 EPIGENETIC MODIFICATION MECHANISMS INVOLVED IN INFLAMMATION AND FIBROSIS IN RENAL PATHOLOGY. THE GROWING INCIDENCE OF OBESITY, HYPERTENSION, AND DIABETES, COUPLED WITH THE AGING OF THE POPULATION, IS INCREASING THE PREVALENCE OF RENAL DISEASES IN OUR SOCIETY. CHRONIC KIDNEY DISEASE (CKD) IS CHARACTERIZED BY PERSISTENT INFLAMMATION, FIBROSIS, AND LOSS OF RENAL FUNCTION LEADING TO END-STAGE RENAL DISEASE. NOWADAYS, CKD TREATMENT HAS LIMITED EFFECTIVENESS UNDERSCORING THE IMPORTANCE OF THE DEVELOPMENT OF INNOVATIVE THERAPEUTIC OPTIONS. RECENT STUDIES HAVE IDENTIFIED HOW EPIGENETIC MODIFICATIONS PARTICIPATE IN THE SUSCEPTIBILITY TO CKD AND HAVE EXPLAINED HOW THE ENVIRONMENT INTERACTS WITH THE RENAL CELL EPIGENOME TO CONTRIBUTE TO RENAL DAMAGE. EPIGENETIC MECHANISMS REGULATE CRITICAL PROCESSES INVOLVED IN GENE REGULATION AND DOWNSTREAM CELLULAR RESPONSES. THE MOST RELEVANT EPIGENETIC MODIFICATIONS THAT PLAY A CRITICAL ROLE IN RENAL DAMAGE INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS, AND CHANGES IN MIRNA LEVELS. IMPORTANTLY, THESE EPIGENETIC MODIFICATIONS ARE REVERSIBLE AND, THEREFORE, A SOURCE OF POTENTIAL THERAPEUTIC TARGETS. HERE, WE WILL EXPLAIN HOW EPIGENETIC MECHANISMS MAY REGULATE ESSENTIAL PROCESSES INVOLVED IN RENAL PATHOLOGY AND HIGHLIGHT SOME POSSIBLE EPIGENETIC THERAPEUTIC STRATEGIES FOR CKD TREATMENT. 2018 7 1983 39 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 8 6409 33 THE SIGNALING OF CELLULAR SENESCENCE IN DIABETIC NEPHROPATHY. DIABETIC NEPHROPATHY IS THE LEADING CAUSE OF CHRONIC KIDNEY DISEASE (CKD) IN WESTERN COUNTRIES. NOTABLY, IT HAS A RAPIDLY RISING PREVALENCE IN CHINA. THE PATIENTS, COMMONLY COMPLICATED WITH CARDIOVASCULAR DISEASES AND NEUROLOGIC DISORDERS, ARE AT HIGH RISK TO PROGRESS INTO END-STAGE RENAL DISEASE (ESRD) AND DEATH. HOWEVER, THE PATHOGENIC MECHANISMS OF DIABETIC NEPHROPATHY HAVE NOT BEEN DETERMINED. CELLULAR SENESCENCE, WHICH RECENTLY HAS GAINED BROAD ATTENTION, IS THOUGHT TO BE AN IMPORTANT PLAYER IN THE ONSET AND DEVELOPMENT OF DIABETIC NEPHROPATHY. IN THIS ISSUE, WE GENERALLY REVIEW THE MECHANISMS OF CELLULAR SENESCENCE IN DIABETIC NEPHROPATHY, WHICH INVOLVE TELOMERE ATTRITION, DNA DAMAGE, EPIGENETIC ALTERATIONS, MITOCHONDRIAL DYSFUNCTION, LOSS OF KLOTHO, WNT/BETA-CATENIN SIGNALING ACTIVATION, PERSISTENT INFLAMMATION, AND ACCUMULATION OF UREMIC TOXINS. MOREOVER, WE HIGHLIGHT THE POTENTIAL THERAPEUTIC TARGETS OF CELLULAR SENESCENCE IN DIABETIC NEPHROPATHY AND PROVIDE IMPORTANT CLUES FOR CLINICAL STRATEGIES. 2019 9 5660 34 SEX-SPECIFIC EPIGENETIC PROGRAMMING IN RENAL FIBROSIS AND INFLAMMATION. THE GROWING PREVALENCE OF HYPERTENSION, HEART DISEASE, DIABETES, AND OBESITY ALONG WITH AN AGING POPULATION, IS LEADING TO HIGHER INCIDENCE OF RENAL DISEASES IN THE SOCIETY. CHRONIC KIDNEY DISEASE (CKD) IS CHARACTERIZED MAINLY BY PERSISTENT INFLAMMATION, FIBROSIS, AND GRADUAL LOSS OF RENAL FUNCTION LEADING TO RENAL FAILURE. SEX IS A KNOWN CONTRIBUTOR TO THE DIFFERENCES IN INCIDENCE AND PROGRESSION OF CKD. EPIGENETIC PROGRAMMING IS AN ESSENTIAL REGULATOR OF RENAL PHYSIOLOGY AND IS CRITICALLY INVOLVED IN THE PATHOPHYSIOLOGY OF RENAL INJURY AND FIBROSIS. EPIGENETIC SIGNALING INTEGRATES INTRINSIC AND EXTRINSIC SIGNALS ONTO THE GENOME, AND VARIOUS ENVIRONMENTAL AND HORMONAL STIMULI, INCLUDING SEX HORMONES, WHICH REGULATE GENE EXPRESSION AND DOWNSTREAM CELLULAR RESPONSES. THE MOST EXTENSIVELY STUDIED EPIGENETIC ALTERATIONS THAT PLAY A CRITICAL ROLE IN RENAL DAMAGE INCLUDE HISTONE MODIFICATIONS AND DNA METHYLATION. NOTABLY, THESE EPIGENETIC ALTERATIONS ARE REVERSIBLE, MAKING THEM CANDIDATES FOR POTENTIAL THERAPEUTIC TARGETS FOR THE TREATMENT OF RENAL DISEASES. HERE, WE WILL SUMMARIZE THE CURRENT KNOWLEDGE ON SEX-DIFFERENCES IN EPIGENETIC MODULATION OF RENAL FIBROSIS AND INFLAMMATION AND HIGHLIGHT SOME POSSIBLE EPIGENETIC THERAPEUTIC STRATEGIES FOR CKD TREATMENT. 2023 10 1487 34 DNA DAMAGE AND EPIGENETIC CHANGES IN KIDNEY DISEASES - FOCUSED ON TRANSCRIPTION FACTORS IN PODOCYTES. RECENTLY IT HAS BEEN SHOWN THAT EPIGENETIC MECHANISMS ARE INVOLVED IN INITIATION AND PROGRESSION OF CARIDIOVASCULAR AND METABOLIC DISEASES, INCLUDING DIABETES, OBESITY, ATHEROSCLEROSIS, HEART FAILURE, HYPERTENSION AND KIDNEY DISEASES. IN THESE CHRONIC DISEASES, VARIOUS EXOGENOUS AND ENDOGENOUS STRESSES CAUSE DNA DAMAGE, FOLLOWED BY DNA REPAIR PROCESS. ACCUMULATION OF DNA DAMAGES AND IMPAIRED REPAIR PROCESS CAN LEAD TO EPIGENETIC CHANGES, WHICH MAY CONTRIBUTE TO ONSET AND PROGRESSION OF DISEASES. RECENTLY WE HAVE SHOWN THAT THERAPEUTIC EFFECT OF TRANSCRIPTION FACTOR KLF4 (KRUPPEL-LIKE FACTOR 4) IN KIDNEY GLOMERULAR EPITHELIAL CELLS (PODOCYTES) ON PROTEINURIC KIDNEY DISEASES THROUGH EPIGENETIC MECHANISMS. OUR RESULT SUGGESTS THE POSSIBILITY OF TRANSCRIPTION FACTORS AS A TARGET OF SELECTIVE EPIGENETIC THERAPY. MOREOVER, WE HAVE REPORTED THAT RENIN-ANGIOTENSIN SYSTEM (RAS) BLOCKERS, WHICH ARE WIDELY PRESCRIBED FOR THE TREATMENT OF CARDIOVASCULAR DISEASES, CAN RESTORE EPIGENETIC CHANGES THROUGH KLF4 IN PART. THESE RESULTS SUGGEST THAT ACTIVATION OF RAS CAUSES EPIGENETIC CHANGES IN DISEASE STATES, AND ELUCIDATION OF THE PRECISE MECHANISM MAY LEAD TO ESTABLISHMENT OF NOVEL THERAPEUTIC TARGET OF KIDNEY DISEASES. IN THIS REVIEW WE FOCUS ON DNA DAMAGE REPAIR SYSTEM AND EPIGENETIC MODULATORS IN DISEASE STATES, AND SPECULATE A CANDIDATE FOR EPIGENETIC THERAPY OF KIDNEY DISEASES. 2016 11 5370 25 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 12 6377 43 THE ROLE OF NON-CODING RNAS IN DIABETIC NEPHROPATHY: POTENTIAL APPLICATIONS AS BIOMARKERS FOR DISEASE DEVELOPMENT AND PROGRESSION. DIABETIC NEPHROPATHY, A PROGRESSIVE KIDNEY DISEASE THAT DEVELOPS SECONDARY TO DIABETES, IS THE MAJOR CAUSE OF CHRONIC KIDNEY DISEASE IN DEVELOPED COUNTRIES, AND CONTRIBUTES SIGNIFICANTLY TO INCREASED MORBIDITY AND MORTALITY AMONG INDIVIDUALS WITH DIABETES. ALTHOUGH THE CAUSES OF DIABETIC NEPHROPATHY ARE NOT FULLY UNDERSTOOD, RECENT STUDIES DEMONSTRATE A ROLE FOR EPIGENETIC FACTORS IN THE DEVELOPMENT OF THE DISEASE. FOR EXAMPLE, NON-CODING RNA (NCRNA) MOLECULES, INCLUDING MICRORNAS (MIRNAS), HAVE BEEN SHOWN TO BE FUNCTIONALLY IMPORTANT IN MODULATING RENAL RESPONSE TO HYPERGLYCEMIA AND PROGRESSION OF DIABETIC NEPHROPATHY. CHARACTERIZATION OF MIRNA EXPRESSION IN DIABETIC NEPHROPATHY FROM STUDIES OF ANIMAL MODELS OF DIABETES, AND IN VITRO INVESTIGATIONS USING DIFFERENT TYPES OF KIDNEY CELLS ALSO SUPPORT THIS ROLE. THE GOAL OF THIS REVIEW, THEREFORE, IS TO SUMMARIZE THE CURRENT STATE OF KNOWLEDGE OF SPECIFIC NCRNAS INVOLVED IN THE DEVELOPMENT OF DIABETIC NEPHROPATHY, WITH A FOCUS ON THE POTENTIAL ROLE OF MIRNAS TO SERVE AS SENSITIVE, NON-INVASIVE BIOMARKERS OF KIDNEY DISEASE AND PROGRESSION. NON-CODING RNAS ARE CURRENTLY RECOGNIZED AS POTENTIALLY IMPORTANT REGULATORS OF GENES INVOLVED IN PROCESSES RELATED TO THE DEVELOPMENT OF DIABETIC NEPHROPATHY, AND AS SUCH, REPRESENT VIABLE TARGETS FOR BOTH CLINICAL DIAGNOSTIC STRATEGIES AND THERAPEUTIC INTERVENTION. 2013 13 2972 35 GENETIC AND EPIGENETIC STUDIES IN DIABETIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE IS A WORLDWIDE HEALTH CRISIS, WHILE DIABETIC KIDNEY DISEASE (DKD) HAS BECOME THE LEADING CAUSE OF END-STAGE RENAL DISEASE (ESRD). DKD IS A MICROVASCULAR COMPLICATION AND OCCURS IN 30-40% OF DIABETES PATIENTS. EPIDEMIOLOGICAL INVESTIGATIONS AND CLINICAL OBSERVATIONS ON THE FAMILIAL CLUSTERING AND HERITABILITY IN DKD HAVE HIGHLIGHTED AN UNDERLYING GENETIC SUSCEPTIBILITY. FURTHERMORE, DKD IS A PROGRESSIVE AND LONG-TERM DIABETIC COMPLICATION, IN WHICH EPIGENETIC EFFECTS AND ENVIRONMENTAL FACTORS INTERACT WITH AN INDIVIDUAL'S GENETIC BACKGROUND. IN RECENT YEARS, RESEARCHERS HAVE UNDERTAKEN GENETIC AND EPIGENETIC STUDIES OF DKD IN ORDER TO BETTER UNDERSTAND ITS MOLECULAR MECHANISMS. IN THIS REVIEW, CLINICAL MATERIAL, RESEARCH APPROACHES AND EXPERIMENTAL DESIGNS THAT HAVE BEEN USED FOR GENETIC AND EPIGENETIC STUDIES OF DKD ARE DESCRIBED. CURRENT INFORMATION FROM GENETIC AND EPIGENETIC STUDIES OF DKD AND ESRD IN PATIENTS WITH DIABETES, INCLUDING THE APPROACHES OF GENOME-WIDE ASSOCIATION STUDY (GWAS) OR EPIGENOME-WIDE ASSOCIATION STUDY (EWAS) AND CANDIDATE GENE ASSOCIATION ANALYSES, ARE SUMMARIZED. FURTHER INVESTIGATION OF MOLECULAR DEFECTS IN DKD WITH NEW APPROACHES SUCH AS NEXT GENERATION SEQUENCING ANALYSIS AND PHENOME-WIDE ASSOCIATION STUDY (PHEWAS) IS ALSO DISCUSSED. 2019 14 4456 28 MOLECULAR MECHANISMS IN RENAL DEGENERATIVE DISEASE. CHRONIC KIDNEY DISEASE (CKD) HAS BECOME A MAJOR PUBLIC HEALTH PROBLEM WORLDWIDE. THEREFORE, A CONSIDERABLE EFFORT IS CURRENTLY DIRECTED TO UNDERSTAND THE MOLECULAR MECHANISMS OF RENAL DEGENERATIVE PROCESSES. REGARDLESS OF THEIR INITIATING CAUSE, ALL CHRONIC KIDNEY DISEASES (CKD) DEVELOP AT SOME LEVEL ORGAN FIBROSIS THAT INTERFERES WITH KIDNEY FUNCTION. THIS IS ALSO TRUE FOR THE TWO MOST COMMON INHERITED CKD SYNDROMES, NEPHRONOPHTHITIS AND POLYCYSTIC KIDNEY DISEASE, WHOSE PRIMARY DEFECTS RESIDE WITHIN THE CILIUM OF KIDNEY EPITHELIAL CELLS. A COHORT OF ELEGANT RECENT STUDIES HAS ELICITED THE ROLE OF THE PRIMARY CILIUM AS A VERSATILE MECHANOSENSORY ORGANELLE THAT ALSO MIGHT COORDINATE CROSS-TALK BETWEEN MULTIPLE SIGNALING PATHWAYS. IN ADDITION, EPIGENETIC MECHANISMS ARE NOW REALIZED TO BE ESSENTIAL IN THE MAINTENANCE OF ADULT RENAL ARCHITECTURE. IN THIS REVIEW, WE WILL DISCUSS RECENT ADVANCES IN OUR UNDERSTANDING OF THE SIGNALING SYSTEMS IMPLICATED IN KIDNEY HOMEOSTASIS AND REPAIR. 2010 15 5923 34 TARGETING DNA METHYLATION IN PODOCYTES TO OVERCOME CHRONIC KIDNEY DISEASE. THE NUMBER OF PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD) IS ON THE RISE WORLDWIDE, AND THERE IS URGENT NEED FOR THE DEVELOPMENT OF EFFECTIVE PLANS AGAINST THE INCREASING INCIDENCE OF CKD. PODOCYTES, GLOMERULAR EPITHELIAL CELLS, ARE AN INTEGRAL PART OF THE PRIMARY FILTRATION UNIT OF THE KIDNEY AND FORM A SLIT MEMBRANE AS A BARRIER TO PREVENT PROTEINURIA. THE ROLE OF PODOCYTES IN THE PATHOGENESIS AND PROGRESSION OF CKD IS NOW RECOGNIZED. PODOCYTE FUNCTION DEPENDS ON A SPECIALIZED MORPHOLOGY WITH THE ARRANGED FOOT PROCESSES, WHICH IS DIRECTLY RELATED TO THEIR FUNCTION. EPIGENETIC CHANGES RESPONSIBLE FOR THE REGULATION OF GENE EXPRESSION RELATED TO PODOCYTE MORPHOLOGY HAVE BEEN SHOWN TO BE IMPORTANT IN THE PATHOGENESIS OF CKD. ALTHOUGH EPIGENETIC MECHANISMS INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS, AND RNA-BASED REGULATION, WE HAVE FOCUSED ON DNA METHYLATION CHANGES BECAUSE THEY ARE MORE STABLE THAN OTHER EPIGENETIC MODIFICATIONS. THIS REVIEW SUMMARIZES RECENT LITERATURE ABOUT THE ROLE OF ALTERED DNA METHYLATION IN THE KIDNEY, ESPECIALLY IN GLOMERULAR PODOCYTES, FOCUSING ON TRANSCRIPTION FACTORS AND DNA DAMAGE RESPONSES THAT ARE CLOSELY ASSOCIATED WITH THE FORMATION OF DNA METHYLATION CHANGES. 2023 16 2542 36 EPIGENETICS IN KIDNEY DISEASES. EPIGENETICS EXAMINES HERITABLE CHANGES IN DNA AND ITS ASSOCIATED PROTEINS EXCEPT MUTATIONS IN GENE SEQUENCE. EPIGENETIC REGULATION PLAYS FUNDAMENTAL ROLES IN KIDNEY CELL BIOLOGY THROUGH THE ACTION OF DNA METHYLATION, CHROMATIN MODIFICATION VIA EPIGENETIC REGULATORS AND NON-CODING RNA SPECIES. KIDNEY DISEASES, INCLUDING ACUTE KIDNEY INJURY, CHRONIC KIDNEY DISEASE, DIABETIC KIDNEY DISEASE AND RENAL FIBROSIS ARE MULTISTEP PROCESSES ASSOCIATED WITH NUMEROUS MOLECULAR ALTERATIONS EVEN IN INDIVIDUAL KIDNEY CELLS. EPIGENETIC ALTERATIONS, INCLUDING ANOMALOUS DNA METHYLATION, ABERRANT HISTONE ALTERATIONS AND CHANGES OF MICRORNA EXPRESSION ALL CONTRIBUTE TO KIDNEY PATHOGENESIS. THESE CHANGES ALTER THE GENOME-WIDE EPIGENETIC SIGNATURES AND DISRUPT ESSENTIAL PATHWAYS THAT PROTECT RENAL CELLS FROM UNCONTROLLED GROWTH, APOPTOSIS AND DEVELOPMENT OF OTHER RENAL ASSOCIATED SYNDROMES. MOLECULAR CHANGES IMPACT CELLULAR FUNCTION WITHIN KIDNEY CELLS AND ITS MICROENVIRONMENT TO DRIVE AND MAINTAIN DISEASE PHENOTYPE. IN THIS CHAPTER, WE BRIEFLY SUMMARIZE EPIGENETIC MECHANISMS IN FOUR KIDNEY DISEASES INCLUDING ACUTE KIDNEY INJURY, CHRONIC KIDNEY DISEASE, DIABETIC KIDNEY DISEASE AND RENAL FIBROSIS. WE PRIMARILY FOCUS ON CURRENT KNOWLEDGE ABOUT THE GENOME-WIDE PROFILING OF DNA METHYLATION AND HISTONE MODIFICATION, AND EPIGENETIC REGULATION ON SPECIFIC GENE(S) IN THE PATHOPHYSIOLOGY OF THESE DISEASES AND THE TRANSLATIONAL POTENTIAL OF IDENTIFYING NEW BIOMARKERS AND TREATMENT FOR PREVENTION AND THERAPY. INCORPORATING EPIGENOMIC TESTING INTO CLINICAL RESEARCH IS ESSENTIAL TO ELUCIDATE NOVEL EPIGENETIC BIOMARKERS AND DEVELOP PRECISION MEDICINE USING EMERGING THERAPIES. 2021 17 6510 32 TRANSCRIPTION FACTORS AND EPIGENETIC MODULATION: ITS THERAPEUTIC IMPLICATION IN CHRONIC KIDNEY DISEASE. RECENTLY EMERGING EVIDENCE HAS SHOWN THAT EPIGENETIC MECHANISMS ARE INVOLVED IN INITIATION AND PROGRESSION OF VARIOUS DISEASES, INCLUDING KIDNEY DISEASES. IN THE PRESENT ARTICLE, WE REVIEW THE CURRENT DATA REGARDING THE ROLE OF EPIGENETIC MODULATION IN CHRONIC KIDNEY DISEASE (CKD) AND KIDNEY FIBROSIS, INCLUDING DNA METHYLATION AND HISTONE MODIFICATION. ESPECIALLY WE FOCUSED ON THE ROLE OF TRANSCRIPTION FACTORS IN EPIGENETIC MODULATION AND THE POSSIBILITY OF THERAPEUTIC TARGET OF CKD. WE HAVE RECENTLY REPORTED THAT TRANSCRIPTION FACTOR KRUPPEL-LIKE FACTOR 4 (ALSO KNOWN AS GUT-ENRICHED KRUPPEL-LIKE FACTOR) IS EXPRESSED IN KIDNEY PODOCYTES (VISCERAL EPITHELIAL CELLS) AND MODULATES PODOCYTE PHENOTYPE BY GENE-SELECTIVE EPIGENETIC CONTROL. TARGETING TRANSCRIPTION FACTORS FOR EPIGENETIC MODIFICATION MAY BE A GOOD CANDIDATE FOR REMISSION AND REGRESSION OF CKD. IT IS NECESSARY FOR THE THERAPY OF CKD WITH AN EPIGENETIC-BASED APPROACH TO INVESTIGATE ORGAN-, TISSUE-, OR GENE-SPECIFIC TREATMENT METHODS FOR REDUCTION OF SIDE EFFECTS. 2015 18 6129 44 THE EPIGENETIC REGULATION OF PODOCYTE FUNCTION IN DIABETES. CHRONIC HYPERGLYCEMIA EARLY IN THE COURSE OF DIABETES CONFERS A SUSTAINED INCREASE IN THE RISK OF COMPLICATIONS DEVELOPMENT. IN RECENT YEARS, EFFORTS TO UNDERSTAND THE MOLECULAR BASIS FOR THIS "METABOLIC MEMORY" HAVE FOCUSED ON EPIGENETIC MECHANISMS AS A MEANS BY WHICH TRANSIENT HIGH GLUCOSE CAN CAUSE PERSISTENT AND PROPAGATED CHANGES IN CELL FUNCTION. FOR INSTANCE, IN VASCULAR ENDOTHELIAL CELLS, SMOOTH MUSCLE CELLS AND PERIPHERAL BLOOD CELLS, TEMPORARY EXPOSURE TO HIGH GLUCOSE CAUSES CHANGES IN EPIGENETIC MARKS THAT PROMOTE A SHIFT TOWARDS A PRO-INFLAMMATORY PHENOTYPE. HOWEVER, THE INFLUENCE OF EPIGENETIC PROCESSES IN COMPLICATIONS DEVELOPMENT EXTENDS BEYOND THEIR CONTRIBUTION TO METABOLIC MEMORY. PODOCYTES, FOR EXAMPLE, ARE TERMINALLY DIFFERENTIATED CELLS OF THE RENAL GLOMERULUS WHOSE INJURY IS A MAJOR CONTRIBUTOR TO THE PATHOGENESIS OF NEPHROPATHY. OVER RECENT MONTHS, SEVERAL REPORTS HAVE EMERGED DESCRIBING THE ESSENTIAL ACTIONS OF HISTONE-MODIFYING ENZYMES AND DNA METHYLATION PATTERNS (THE TWO PRINCIPAL EPIGENETIC MECHANISMS) IN MAINTAINING PODOCYTE INTEGRITY, ESPECIALLY UNDER DIABETIC CONDITIONS. HERE, WE REVIEW THE KNOWN AND POTENTIAL ROLE OF EPIGENETIC PROCESSES WITHIN PODOCYTES, FOCUSING ON THE EVIDENCE LINKING THESE PROCESSES TO OXIDATIVE STRESS, CROSSTALK WITH TUBULE CELLS, AUTOPHAGY AND SLIT-PORE PROTEIN EXPRESSION. WHETHER PODOCYTES THEMSELVES EXHIBIT A METABOLIC MEMORY AWAITS TO BE SEEN. 2015 19 3826 35 INVESTIGATION OF EPIGENETICS IN KIDNEY CELL BIOLOGY. EPIGENETICS IS THE STUDY OF HERITABLE CHANGES IN DNA OR ITS ASSOCIATED PROTEINS EXCEPT MUTATIONS IN GENE SEQUENCE. EPIGENETIC REGULATION PLAYS FUNDAMENTAL ROLES IN THE PROCESSES OF KIDNEY CELL BIOLOGY THROUGH THE ACTION OF DNA METHYLATION, CHROMATIN MODIFICATIONS VIA EPIGENETIC REGULATORS AND INTERACTION VIA TRANSCRIPTION FACTORS, AND NONCODING RNA SPECIES. KIDNEY DISEASES, INCLUDING ACUTE KIDNEY INJURY, CHRONIC KIDNEY DISEASE, NEPHRITIC AND NEPHROTIC SYNDROMES, PYELONEPHRITIS AND POLYCYSTIC KIDNEY DISEASES ARE DRIVEN BY ABERRANT ACTIVITY IN NUMEROUS SIGNALING PATHWAYS IN EVEN INDIVIDUAL KIDNEY CELL. EPIGENETIC ALTERATIONS, INCLUDING DNA METHYLATION, HISTONE ACETYLATION AND METHYLATION, NONCODING RNAS, AND PROTEIN POSTTRANSLATIONAL MODIFICATIONS, COULD DISRUPT ESSENTIAL PATHWAYS THAT PROTECT THE RENAL CELLS FROM UNCONTROLLED GROWTH, APOPTOSIS AND ESTABLISHMENT OF OTHER RENAL ASSOCIATED SYNDROMES, WHICH HAVE BEEN RECOGNIZED AS ONE OF THE CRITICAL MECHANISMS FOR REGULATING FUNCTIONAL CHANGES THAT DRIVE AND MAINTAIN THE KIDNEY DISEASE PHENOTYPE. IN THIS CHAPTER, WE BRIEFLY SUMMARIZE THE EPIGENETIC MECHANISMS IN KIDNEY CELL BIOLOGY AND EPIGENETIC BASIS OF KIDNEY DEVELOPMENT, AND INTRODUCE EPIGENETIC TECHNIQUES THAT CAN BE USED IN INVESTIGATING THE MOLECULAR MECHANISM OF KIDNEY CELL BIOLOGY AND KIDNEYS DISEASES, PRIMARILY FOCUSING ON THE INTEGRATION OF DNA METHYLATION AND CHROMATIN IMMUNOPRECIPITATION TECHNOLOGIES INTO KIDNEY DISEASE ASSOCIATED STUDIES. FUTURE STUDIES USING THESE EMERGING TECHNOLOGIES WILL ELUCIDATE HOW ALTERATIONS IN THE RENAL CELL EPIGENOME COOPERATE WITH GENETIC ABERRATIONS FOR KIDNEY DISEASE INITIATION AND PROGRESSION. INCORPORATING EPIGENOMIC TESTING INTO THE CLINICAL RESEARCH IS ESSENTIAL TO FUTURE STUDIES WITH EPIGENETICS BIOMARKERS AND PRECISION MEDICINE USING EMERGING EPIGENETIC THERAPIES. 2019 20 6299 41 THE PROXIMAL TUBULE IS THE PRIMARY TARGET OF INJURY AND PROGRESSION OF KIDNEY DISEASE: ROLE OF THE GLOMERULOTUBULAR JUNCTION. THERE IS AN ALARMING GLOBAL INCREASE IN THE INCIDENCE OF END-STAGE KIDNEY DISEASE, FOR WHICH EARLY BIOMARKERS AND EFFECTIVE TREATMENT OPTIONS ARE LACKING. LARGELY BASED ON THE HISTOLOGY OF THE END-STAGE KIDNEY AND ON THE MODEL OF UNILATERAL URETERAL OBSTRUCTION, CURRENT INVESTIGATION IS FOCUSED ON THE PATHOGENESIS OF RENAL INTERSTITIAL FIBROSIS AS A CENTRAL MECHANISM IN THE PROGRESSION OF CHRONIC KIDNEY DISEASE (CKD). IT IS NOW RECOGNIZED THAT CUMULATIVE EPISODES OF ACUTE KIDNEY INJURY (AKI) CAN LEAD TO CKD, AND, CONVERSELY, CKD IS A RISK FACTOR FOR AKI. BASED ON RECENT AND HISTORIC STUDIES, THIS REVIEW SHIFTS ATTENTION FROM THE GLOMERULUS AND INTERSTITIUM TO THE PROXIMAL TUBULE AS THE PRIMARY SENSOR AND EFFECTOR IN THE PROGRESSION OF CKD AS WELL AS AKI. PACKED WITH MITOCHONDRIA AND DEPENDENT ON OXIDATIVE PHOSPHORYLATION, THE PROXIMAL TUBULE IS PARTICULARLY VULNERABLE TO INJURY (OBSTRUCTIVE, ISCHEMIC, HYPOXIC, OXIDATIVE, METABOLIC), RESULTING IN CELL DEATH AND ULTIMATELY IN THE FORMATION OF ATUBULAR GLOMERULI. ANIMAL MODELS OF HUMAN GLOMERULAR AND TUBULAR DISORDERS HAVE PROVIDED EVIDENCE FOR A BROAD REPERTOIRE OF MORPHOLOGICAL AND FUNCTIONAL RESPONSES OF THE PROXIMAL TUBULE, REVEALING PROCESSES OF DEGENERATION AND REPAIR THAT MAY LEAD TO NEW THERAPEUTIC STRATEGIES. MOST PROMISING ARE STUDIES THAT ENCOMPASS THE ENTIRE LIFE CYCLE FROM FETUS TO SENESCENCE, RECOGNIZING EPIGENETIC FACTORS. THE APPLICATION OF TECHNIQUES IN MOLECULAR CHARACTERIZATION OF TUBULE SEGMENTS AND THE DEVELOPMENT OF HUMAN KIDNEY ORGANOIDS MAY PROVIDE NEW INSIGHTS INTO THE MAMMALIAN KIDNEY SUBJECTED TO STRESS OR INJURY, LEADING TO BIOMARKERS OF EARLY CKD AND NEW THERAPIES. 2016