1 2230 107 EPIGENETIC MODIFICATIONS OF KLOTHO EXPRESSION IN KIDNEY DISEASES. DEVELOPMENTS OF MANY RENAL DISEASES ARE SUBSTANTIALLY INFLUENCED BY EPIGENETIC MODIFICATIONS OF NUMEROUS GENES, MAINLY MEDIATED BY DNA METHYLATIONS, HISTONE MODIFICATIONS, AND MICRORNA INTERFERENCE; HOWEVER, NOT ALL GENE MODIFICATIONS CAUSALLY AFFECT THE DISEASE ONSET OR PROGRESSION. KLOTHO IS A CRITICAL GENE WHOSE REPRESSIONS IN VARIOUS PATHOLOGICAL CONDITIONS REPORTEDLY INVOLVE EPIGENETIC REGULATORY MECHANISMS. KLOTHO IS ALMOST UNEXCEPTIONALLY REPRESSED EARLY AFTER ACUTE OR CHRONIC RENAL INJURIES AND ITS LEVELS INVERSELY CORRELATED WITH THE DISEASE PROGRESSION AND SEVERITY. MOREOVER, THE STRATEGIES OF KLOTHO DEREPRESSION VIA EPIGENETIC MODULATIONS BENEFICIALLY CHANGE THE PATHOLOGICAL COURSES BOTH IN VITRO AND IN VIVO. HENCE, KLOTHO IS NOT ONLY CONSIDERED A BIOMARKER OF THE RENAL DISEASE BUT ALSO A POTENTIAL OR EVEN AN IDEAL TARGET OF THERAPEUTIC EPIGENETIC INTERVENTION. HERE, WE SUMMARIZE AND DISCUSS STUDIES THAT INVESTIGATE THE KLOTHO REPRESSION AND INTERVENTION IN RENAL DISEASES FROM AN EPIGENETIC POINT OF VIEW. THESE INFORMATION MIGHT SHED NEW SIGHTS INTO THE EFFECTIVE THERAPEUTIC STRATEGIES TO PREVENT AND TREAT VARIOUS RENAL DISORDERS. 2021 2 2589 32 EPIGENETICS OF PROGRESSION OF CHRONIC KIDNEY DISEASE: FACT OR FANTASY? EPIGENETIC MODIFICATIONS ARE IMPORTANT IN THE NORMAL FUNCTIONING OF THE CELL, FROM REGULATING DYNAMIC EXPRESSION OF ESSENTIAL GENES AND ASSOCIATED PROTEINS TO REPRESSING THOSE THAT ARE UNNEEDED. EPIGENETIC CHANGES ARE ESSENTIAL FOR DEVELOPMENT AND FUNCTIONING OF THE KIDNEY, AND ABERRANT METHYLATION, HISTONE MODIFICATIONS, AND EXPRESSION OF MICRORNA COULD LEAD TO CHRONIC KIDNEY DISEASE (CKD). HERE, EPIGENETIC MODIFICATIONS MODULATE TRANSFORMING GROWTH FACTOR BETA SIGNALING, INFLAMMATION, PROFIBROTIC GENES, AND THE EPITHELIAL-TO-MESENCHYMAL TRANSITION, PROMOTING RENAL FIBROSIS AND PROGRESSION OF CKD. IDENTIFICATION OF THESE EPIGENETIC CHANGES IS IMPORTANT BECAUSE THEY ARE POTENTIALLY REVERSIBLE AND MAY SERVE AS THERAPEUTIC TARGETS IN THE FUTURE TO PREVENT SUBSEQUENT RENAL FIBROSIS AND CKD. IN THIS REVIEW WE DISCUSS THE DIFFERENT TYPES OF EPIGENETIC CONTROL, METHODS TO STUDY EPIGENETIC MODIFICATIONS, AND HOW EPIGENETICS PROMOTES PROGRESSION OF CKD. 2013 3 6510 34 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 4 4719 33 NONCODING RNA AND EPIGENETIC GENE REGULATION IN RENAL DISEASES. KIDNEYS HAVE A MAJOR ROLE IN NORMAL PHYSIOLOGY AND METABOLIC HOMEOSTASIS. LOSS OR IMPAIRMENT OF KIDNEY FUNCTION IS A COMMON OCCURRENCE IN SEVERAL METABOLIC DISORDERS, INCLUDING HYPERTENSION AND DIABETES. CHRONIC KIDNEY DISEASE (CKD) AFFECT NEARLY 10% OF THE POPULATION WORLDWIDE; RANKS 18TH IN THE LIST OF CAUSES OF DEATH; AND CONTRIBUTES TO A SIGNIFICANT PROPORTION OF HEALTHCARE COSTS. THE TISSUE REPAIR AND REGENERATIVE POTENTIAL OF KIDNEYS ARE LIMITED AND THEY DECLINE DURING AGING. RECENT STUDIES HAVE DEMONSTRATED A KEY ROLE FOR EPIGENETIC PROCESSES AND PLAYERS, SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS, NONCODING (NC)RNA, AND SO ON, IN BOTH KIDNEY DEVELOPMENT AND DISEASE. IN THIS REVIEW, WE HIGHLIGHT THESE RECENT FINDINGS WITH AN EMPHASIS ON ABERRANT EPIGENETIC CHANGES THAT ACCOMPANY RENAL DISEASES, KEY TARGETS, AND THEIR THERAPEUTIC VALUE. 2017 5 3826 41 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 6 1487 26 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 7 6665 37 UPSTREAM AND DOWNSTREAM REGULATORS OF KLOTHO EXPRESSION IN CHRONIC KIDNEY DISEASE. KLOTHO IS A CRITICAL PROTEIN THAT PROTECTS THE KIDNEY. KLOTHO IS SEVERELY DOWNREGULATED IN CHRONIC KIDNEY DISEASE (CKD), AND ITS DEFICIENCY IS IMPLICATED IN THE PATHOGENESIS AND PROGRESSION OF CKD. CONVERSELY, AN INCREASE IN KLOTHO LEVELS RESULTS IN IMPROVED KIDNEY FUNCTION AND DELAYS CKD PROGRESSION, SUPPORTING THE NOTION THAT MODULATING KLOTHO LEVELS COULD REPRESENT A POSSIBLE THERAPEUTIC STRATEGY FOR CKD TREATMENT. NEVERTHELESS, THE REGULATORY MECHANISMS RESPONSIBLE FOR THE LOSS OF KLOTHO REMAIN ELUSIVE. PREVIOUS STUDIES HAVE DEMONSTRATED THAT OXIDATIVE STRESS, INFLAMMATION, AND EPIGENETIC MODIFICATIONS CAN MODULATE KLOTHO LEVELS. THESE MECHANISMS RESULT IN A DECREASE IN KLOTHO MRNA TRANSCRIPT LEVELS AND REDUCED TRANSLATION, THUS CAN BE GROUPED TOGETHER AS UPSTREAM REGULATORY MECHANISMS. HOWEVER, THERAPEUTIC STRATEGIES THAT AIM TO RESCUE KLOTHO LEVELS BY TARGETING THESE UPSTREAM MECHANISMS DO NOT ALWAYS RESULT IN INCREASED KLOTHO, INDICATING THE INVOLVEMENT OF OTHER REGULATORY MECHANISMS. EMERGING EVIDENCE HAS SHOWN THAT ENDOPLASMIC RETICULUM (ER) STRESS, THE UNFOLDED PROTEIN RESPONSE, AND ER-ASSOCIATED DEGRADATION ALSO AFFECT THE MODIFICATION, TRANSLOCATION, AND DEGRADATION OF KLOTHO, AND THUS ARE PROPOSED TO BE DOWNSTREAM REGULATORY MECHANISMS. HERE, WE DISCUSS THE CURRENT UNDERSTANDING OF UPSTREAM AND DOWNSTREAM REGULATORY MECHANISMS OF KLOTHO AND EXAMINE POTENTIAL THERAPEUTIC STRATEGIES TO UPREGULATE KLOTHO EXPRESSION FOR CKD TREATMENT. 2023 8 2195 36 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 9 6511 31 TRANSCRIPTION FACTORS AS THERAPEUTIC TARGETS IN CHRONIC KIDNEY DISEASE. THE GROWING NUMBER OF PATIENTS WITH CHRONIC KIDNEY DISEASE (CKD) IS RECOGNIZED AS AN EMERGING PROBLEM WORLDWIDE. RECENT STUDIES HAVE INDICATED THAT DEREGULATION OF TRANSCRIPTION FACTORS IS ASSOCIATED WITH THE ONSET OR PROGRESSION OF KIDNEY DISEASE. SEVERAL CLINICAL TRIALS INDICATED THAT REGRESSION OF CKD MAY BE FEASIBLE VIA ACTIVATION OF THE TRANSCRIPTION FACTOR NUCLEAR FACTOR ERYTHROID-2 RELATED FACTOR 2 (NRF2), WHICH SUGGESTS THAT TRANSCRIPTION FACTORS MAY BE POTENTIAL DRUG TARGETS FOR CKD. AGENTS STABILIZING HYPOXIA-INDUCIBLE FACTOR (HIF), WHICH MAY BE BENEFICIAL FOR RENAL ANEMIA AND RENAL PROTECTION, ARE ALSO NOW UNDER CLINICAL TRIAL. RECENTLY, WE HAVE REPORTED THAT THE TRANSCRIPTION FACTOR KRUPPEL-LIKE FACTOR 4 (KLF4) REGULATES THE GLOMERULAR PODOCYTE EPIGENOME, AND THAT THE ANTIPROTEINURIC EFFECT OF THE RENIN(-)ANGIOTENSIN SYSTEM BLOCKADE MAY BE PARTIALLY MEDIATED BY KLF4. KLF4 IS ONE OF THE YAMANAKA FACTORS THAT INDUCES IPS CELLS AND IS REPORTED TO BE INVOLVED IN EPIGENETIC REMODELING. IN THIS ARTICLE, WE SUMMARIZE THE TRANSCRIPTION FACTORS ASSOCIATED WITH CKD AND PARTICULARLY FOCUS ON THE POSSIBILITY OF TRANSCRIPTION FACTORS BEING NOVEL DRUG TARGETS FOR CKD THROUGH EPIGENETIC MODULATION. 2018 10 1515 35 DNA METHYLATION AND THE POTENTIAL ROLE OF DEMETHYLATING AGENTS IN PREVENTION OF PROGRESSIVE CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS A GLOBAL EPIDEMIC, AND ITS MAJOR RISK FACTORS INCLUDE OBESITY AND TYPE 2 DIABETES. OBESITY NOT ONLY PROMOTES METABOLIC DYSREGULATION AND THE DEVELOPMENT OF DIABETIC KIDNEY DISEASE BUT ALSO MAY INDEPENDENTLY LEAD TO CKD BY A VARIETY OF MECHANISMS, INCLUDING ENDOCRINE AND METABOLIC DYSFUNCTION, INFLAMMATION, OXIDATIVE STRESS, ALTERED RENAL HEMODYNAMICS, AND LIPOTOXICITY. DELETERIOUS RENAL EFFECTS OF OBESITY CAN ALSO BE TRANSMITTED FROM ONE GENERATION TO THE NEXT, AND IT IS INCREASINGLY RECOGNIZED THAT OFFSPRING OF OBESE MOTHERS ARE PREDISPOSED TO CKD. EPIGENETIC MODIFICATIONS ARE CHANGES THAT REGULATE GENE EXPRESSION WITHOUT ALTERING THE DNA SEQUENCE. OF THESE, DNA METHYLATION IS THE MOST STUDIED. EPIGENETIC IMPRINTS, PARTICULARLY DNA METHYLATION, ARE LAID DOWN DURING CRITICAL PERIODS OF FETAL DEVELOPMENT, AND THEY MAY PROVIDE A MECHANISM BY WHICH MATERNAL-FETAL TRANSMISSION OF CHRONIC DISEASE OCCURS. OUR CURRENT REVIEW EXPLORES THE EVIDENCE FOR THE ROLE OF DNA METHYLATION IN THE DEVELOPMENT OF CKD, DIABETIC KIDNEY DISEASE, DIABETES, AND OBESITY. DNA METHYLATION HAS BEEN IMPLICATED IN RENAL FIBROSIS-THE FINAL PATHOPHYSIOLOGIC PATHWAY IN THE DEVELOPMENT OF END-STAGE KIDNEY DISEASE-WHICH SUPPORTS THE NOTION THAT DEMETHYLATING AGENTS MAY PLAY A POTENTIAL THERAPEUTIC ROLE IN PREVENTING DEVELOPMENT AND PROGRESSION OF CKD.-LARKIN, B. P., GLASTRAS, S. J., CHEN, H., POLLOCK, C. A., SAAD, S. DNA METHYLATION AND THE POTENTIAL ROLE OF DEMETHYLATING AGENTS IN PREVENTION OF PROGRESSIVE CHRONIC KIDNEY DISEASE. 2018 11 4668 36 NEW INSIGHTS INTO MOLECULAR MECHANISMS OF EPIGENETIC REGULATION IN KIDNEY DISEASE. THE NUMBER OF PATIENTS WITH KIDNEY FAILURE HAS INCREASED IN RECENT YEARS. DIFFERENT FACTORS CONTRIBUTE TO THE PROGRESSION OF CHRONIC KIDNEY DISEASE, INCLUDING GLOMERULAR SCLEROSIS, ATHEROSCLEROSIS OF THE RENAL ARTERIES AND TUBULOINTERSTITIAL FIBROSIS. TUBULOINTERSTITIAL INJURY IS INDUCED BY HYPOXIA AND OTHER INFLAMMATORY SIGNALS, LEADING TO FIBROBLAST ACTIVATION. TECHNOLOGICAL ADVANCES USING HIGH-THROUGHPUT SEQUENCING HAS ENABLED THE DETERMINATION OF THE EXPRESSION PROFILE OF ALMOST ALL GENES, REVEALING THAT GENE EXPRESSION IS INTRICATELY REGULATED BY DNA METHYLATION, HISTONE MODIFICATION, CHANGES IN CHROMOSOME CONFORMATION, LONG NON-CODING RNAS AND MICRORNAS. THESE EPIGENETIC MODIFICATIONS ARE STORED AS CELLULAR EPIGENETIC MEMORY. EPIGENETIC MEMORY LEADS TO ADULT-ONSET DISEASE OR AGEING IN THE LONG TERM AND MAY POSSIBLY PLAY AN IMPORTANT ROLE IN THE KIDNEY DISEASE PROCESS. HEREIN WE EMPHASIZE THE IMPORTANCE OF CLARIFYING THE MOLECULAR MECHANISMS UNDERLYING EPIGENETIC MODIFICATIONS BECAUSE THIS MAY LEAD TO THE DEVELOPMENT OF NEW THERAPEUTIC TARGETS IN KIDNEY DISEASE. 2016 12 4250 34 METHYLATION-DEMETHYLATION DYNAMICS: IMPLICATIONS OF CHANGES IN ACUTE KIDNEY INJURY. OVER THE YEARS, THE EPIGENETIC LANDSCAPE HAS GROWN INCREASINGLY COMPLEX. UNTIL RECENTLY, METHYLATION OF DNA AND HISTONES WAS CONSIDERED ONE OF THE MOST IMPORTANT EPIGENETIC MODIFICATIONS. HOWEVER, WITH THE DISCOVERY OF ENZYMES INVOLVED IN THE DEMETHYLATION PROCESS, SEVERAL EXCITING PROSPECTS HAVE EMERGED THAT FOCUS ON THE DYNAMIC REGULATION OF METHYLATION AND ITS CRUCIAL ROLE IN DEVELOPMENT AND DISEASE. AN INTERPLAY OF THE METHYLATION-DEMETHYLATION MACHINERY CONTROLS THE PROCESS OF GENE EXPRESSION. SINCE ACUTE KIDNEY INJURY (AKI), A MAJOR RISK FACTOR FOR CHRONIC KIDNEY DISEASE AND DEATH, IS CHARACTERISED BY ABERRANT EXPRESSION OF GENES, UNDERSTANDING THE DYNAMICS OF METHYLATION AND DEMETHYLATION WILL PROVIDE NEW INSIGHTS INTO THE INTRICACIES OF THE DISEASE. RESEARCH ON EPIGENETICS IN AKI HAS ONLY MADE ITS MARK IN THE RECENT YEARS BUT HAS PROVIDED COMPELLING EVIDENCE THAT IMPLICATES THE INVOLVEMENT OF METHYLATION AND DEMETHYLATION CHANGES IN ITS PATHOPHYSIOLOGY. IN THIS REVIEW, WE EXPLORE THE ROLE OF METHYLATION AND DEMETHYLATION MACHINERY IN CELLULAR EPIGENETIC CONTROL AND FURTHER DISCUSS THE CONTRIBUTION OF METHYLOMIC CHANGES AND HISTONE MODIFICATIONS TO THE PATHOPHYSIOLOGY OF AKI. 2018 13 607 40 BEYOND GENETICS: EPIGENETIC CODE IN CHRONIC KIDNEY DISEASE. EPIGENETICS REFERS TO A HERITABLE CHANGE IN THE PATTERN OF GENE EXPRESSION THAT IS MEDIATED BY A MECHANISM SPECIFICALLY NOT DUE TO ALTERATIONS IN THE PRIMARY NUCLEOTIDE SEQUENCE. WELL-KNOWN EPIGENETIC MECHANISMS ENCOMPASS DNA METHYLATION, CHROMATIN REMODELING (HISTONE MODIFICATIONS), AND RNA INTERFERENCE. FUNCTIONALLY, EPIGENETICS PROVIDES AN EXTRA LAYER OF TRANSCRIPTIONAL CONTROL AND PLAYS A CRUCIAL ROLE IN NORMAL PHYSIOLOGICAL DEVELOPMENT, AS WELL AS IN PATHOLOGICAL CONDITIONS. ABERRANT DNA METHYLATION IS IMPLICATED IN IMMUNE DYSFUNCTION, INFLAMMATION, AND INSULIN RESISTANCE. EPIGENETIC CHANGES MAY BE RESPONSIBLE FOR 'METABOLIC MEMORY' AND DEVELOPMENT OF MICRO- AND MACROVASCULAR COMPLICATIONS OF DIABETES. MICRORNAS ARE CRITICAL IN THE MAINTENANCE OF GLOMERULAR HOMEOSTASIS AND HENCE RNA INTERFERENCE MAY BE IMPORTANT IN THE PROGRESSION OF RENAL DISEASE. RECENT STUDIES HAVE SHOWN THAT EPIGENETIC MODIFICATIONS ORCHESTRATE THE EPITHELIAL-MESENCHYMAL TRANSITION AND EVENTUALLY FIBROSIS OF THE RENAL TISSUE. OXIDATIVE STRESS, INFLAMMATION, HYPERHOMOCYSTEINEMIA, AND UREMIC TOXINS COULD INDUCE EPIMUTATIONS IN CHRONIC KIDNEY DISEASE. EPIGENETIC ALTERATIONS ARE ASSOCIATED WITH INFLAMMATION AND CARDIOVASCULAR DISEASE IN PATIENTS WITH CHRONIC KIDNEY DISEASE. REVERSIBLE NATURE OF THE EPIGENETIC CHANGES GIVES A UNIQUE OPPORTUNITY TO HALT OR EVEN REVERSE THE DISEASE PROCESS THROUGH TARGETED THERAPEUTIC STRATEGIES. 2011 14 1505 28 DNA METHYLATION AND HISTONE MODIFICATION IN HYPERTENSION. SYSTEMIC HYPERTENSION, WHICH EVENTUALLY RESULTS IN HEART FAILURE, RENAL FAILURE OR STROKE, IS A COMMON CHRONIC HUMAN DISORDER THAT PARTICULARLY AFFECTS ELDERS. ALTHOUGH MANY SIGNALING PATHWAYS INVOLVED IN THE DEVELOPMENT OF HYPERTENSION HAVE BEEN REPORTED OVER THE PAST DECADES, WHICH HAS LED TO THE IMPLEMENTATION OF A WIDE VARIETY OF ANTI-HYPERTENSIVE THERAPIES, ONE HALF OF ALL HYPERTENSIVE PATIENTS STILL DO NOT HAVE THEIR BLOOD PRESSURE CONTROLLED. THE FRONTIER IN UNDERSTANDING THE MOLECULAR MECHANISMS UNDERLYING HYPERTENSION HAS NOW ADVANCED TO THE LEVEL OF EPIGENOMICS. PARTICULARLY, INCREASING EVIDENCE IS EMERGING THAT DNA METHYLATION AND HISTONE MODIFICATIONS PLAY AN IMPORTANT ROLE IN GENE REGULATION AND ARE INVOLVED IN ALTERATION OF THE PHENOTYPE AND FUNCTION OF VASCULAR CELLS IN RESPONSE TO ENVIRONMENTAL STRESSES. THIS REVIEW SEEKS TO HIGHLIGHT THE RECENT ADVANCES IN OUR KNOWLEDGE OF THE EPIGENETIC REGULATIONS AND MECHANISMS OF HYPERTENSION, FOCUSING ON THE ROLE OF DNA METHYLATION AND HISTONE MODIFICATION IN THE VASCULAR WALL. A BETTER UNDERSTANDING OF THE EPIGENOMIC REGULATION IN THE HYPERTENSIVE VESSEL MAY LEAD TO THE IDENTIFICATION OF NOVEL TARGET MOLECULES THAT, IN TURN, MAY LEAD TO NOVEL DRUG DISCOVERIES FOR THE TREATMENT OF HYPERTENSION. 2018 15 2542 40 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 16 5660 37 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 17 2609 29 EPIGENETICS: A POTENTIAL KEY MECHANISM INVOLVED IN THE PATHOGENESIS OF CARDIORENAL SYNDROMES. EPIGENETICS IS DEFINED AS THE HERITABLE CHANGES IN GENE EXPRESSION PATTERNS WHICH ARE NOT DIRECTLY ENCODED BY MODIFICATIONS IN THE NUCLEOTIDE DNA SEQUENCE OF THE GENOME, INCLUDING HIGHER ORDER CHROMATIN ORGANIZATION, DNA METHYLATION, CYTOSINE MODIFICATIONS, COVALENT HISTONE TAIL MODIFICATIONS, AND SHORT NON-CODING RNA MOLECULES. RECENTLY, MUCH ATTENTION HAS BEEN PAID TO THE ROLE AND THE FUNCTION OF EPIGENETICS AND EPIMUTATIONS IN THE CELLULAR AND SUBCELLULAR PATHWAYS AND IN THE REGULATION OF GENES IN THE SETTING OF BOTH KIDNEY AND CARDIOVASCULAR DISEASE. INDEED, DEREGULATION OF HISTONE ALTERATIONS HAS BEEN HIGHLIGHTED IN A LARGE SPECTRUM OF RENAL AND CARDIAC DISEASE, INCLUDING CHRONIC AND ACUTE RENAL INJURY, RENAL AND CARDIAC FIBROSIS, CARDIAC HYPERTROPHY AND FAILURE, KIDNEY CONGENITAL ANOMALIES, RENAL HYPOXIA, AND DIABETIC RENAL COMPLICATIONS. NEVERTHELESS, THE ROLE OF EPIGENETICS IN THE PATHOGENESIS AND PATHOPHYSIOLOGY OF CARDIORENAL SYNDROMES IS CURRENTLY UNDEREXPLORED. GIVEN THE SIGNIFICANT CLINICAL RELEVANCE OF HEART-KIDNEY CROSSTALK, EFFORTS IN THE RESEARCH FOR NEW ACTION MECHANISMS CONCURRENTLY OPERATING IN BOTH PATHOLOGIES ARE THUS OF MAXIMUM INTEREST. THIS REVIEW FOCUSES ON EPIGENETIC MECHANISMS INVOLVED IN HEART AND KIDNEY DISEASE, AND THEIR POSSIBLE ROLE IN THE SETTING OF CARDIORENAL SYNDROMES. 2018 18 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 19 1060 34 CLINICAL RELEVANCE OF EPIGENETIC DYSREGULATION IN CHRONIC KIDNEY DISEASE-ASSOCIATED CARDIOVASCULAR DISEASE. ACROSS THE SPECTRUM OF CLINICAL MEDICINE, THE FIELD OF EPIGENETICS HAS GAINED SUBSTANTIAL SCIENTIFIC INTEREST IN RECENT YEARS. EPIGENETICS REFERS TO MODIFICATIONS IN GENE EXPRESSION WHICH ARE NOT EXPLAINED BY CHANGES IN DNA SEQUENCE. CLASSICAL COMPONENTS OF EPIGENETIC REGULATION COMPRISE DNA METHYLATION, HISTONE MODIFICATIONS AND RNA INTERFERENCE. IN CHRONIC KIDNEY DISEASE (CKD), SEVERAL FEATURES OF URAEMIA, SUCH AS HYPERHOMOCYSTEINEMIA AND INFLAMMATION, MAY CONTRIBUTE TO CHANGES IN EPIGENETIC GENE REGULATION. IT HAS BEEN SUGGESTED THAT THESE CHANGES MAY AFFECT GENES RELATED TO CARDIOVASCULAR DISEASE. THEREBY, A URAEMIA-ASSOCIATED DISTURBANCE IN EPIGENETIC REGULATION MAY CONTRIBUTE TO THE SUBSTANTIAL INCREASE IN CARDIOVASCULAR MORBIDITY IN CKD PATIENTS. THE PRESENT REVIEW AIMS TO SUMMARIZE CURRENT KNOWLEDGE OF EPIGENETIC DYSREGULATION IN CARDIOVASCULAR DISEASE FROM A NEPHROLOGICAL PERSPECTIVE, WITH A SPECIAL FOCUS ON DNA METHYLATION. WE FIRST DESCRIBE THE IMPACT OF ALTERED EPIGENETIC REGULATION IN NON-CKD-ASSOCIATED ARTERIOSCLEROSIS, AND NEXT CHARACTERIZE URAEMIC FEATURES WHICH MAY AFFECT EPIGENETIC GENE REGULATION IN THE CONTEXT OF CARDIOVASCULAR DISEASE. FINALLY, WE CONCLUDE THAT SUBSTANTIAL ADDITIONAL WORK IS NEEDED BEFORE EPIGENETIC REGULATORY MECHANISMS MAY BECOME THERAPEUTIC TARGETS IN CKD-ASSOCIATED CARDIOVASCULAR DISEASE. 2013 20 5288 24 PROSPECTS FOR EPIGENETIC COMPOUNDS IN THE TREATMENT OF AUTOIMMUNE DISEASE. THERE IS GROWING EVIDENCE FOR A ROLE FOR EPIGENETIC MECHANISMS IN THE DEVELOPMENT OF AUTOIMMUNE DISEASES. IN MOST CASES OFAUTOIMMUNE DISEASE THE PRECISE EPIGENETIC MECHANISM INVOLVED REMAINS TO BE RESOLVED, HOWEVER DNA HYPOMETHYLATION ACCOMPANIED BY HYPOACETYLATION OFHISTONE H3/H4 IS COMMONLY OBSERVED. DUE TO THE REVERSIBLE NATURE OF EPIGENETIC MARKS THEIR MAINTENANCE ENZYMES SUCH AS DNA METHYLTRANSFERASES (DNMTS), HISTONE DEACETYLASES (HDACS) AND HISTONE LYSINE METHYLTRANSFERASES (HKMT) ARE ATTRACTIVE DRUG TARGETS. SMALL MOLECULE INHIBITORS OF HISTONE MODIFICATION AND DNA METHYLATION MAINTENANCE ARE INCREASINGLY BECOMING AVAILABLE AND WILL BE USEFUL CHEMICAL BIOLOGICAL TOOLS TO DISSECT EPIGENETIC MECHANISMS IN THESE DISEASES. HOWEVER, ALTHOUGH EPIGENETIC THERAPIES USED IN CANCER TREATMENT ARE A PROMISING STARTING POINT FOR THE EXPLORATION OF AUTOIMMUNE DISEASE TREATMENT, THERE IS A REQUIREMENT FOR MORE SPECIFIC AND LESS TOXIC AGENTS FOR THESE CHRONIC DISEASES OR FOR USE AS CHEMOPREVENTATIVE AGENTS. 2011