1 1060 105 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 2 2154 48 EPIGENETIC MECHANISMS AND KIDNEY DISEASES. IN RECENT YEARS, MOLECULAR RESEARCH HAS BROUGHT TO LIGHT A SERIES OF MECHANISMS INVOLVED IN THE REGULATION OF GENE FUNCTION WITHOUT ALTERING THE DNA SEQUENCE. THESE MECHANISMS ARE DESCRIBED WITH THE TERM "EPIGENETICS" AND INCLUDE MODIFICATIONS IN THE STRUCTURE OF THE HUMAN GENOME, LEADING TO HERITABLE AND POTENTIALLY REVERSIBLE CHANGES IN GENE EXPRESSION. THERE IS NOW INCREASING EVIDENCE SUGGESTING THAT SEVERAL CHARACTERISTIC FEATURES OF CHRONIC KIDNEY DISEASE SUCH AS HYPERHOMOCYSTEINEMIA, SUBCLINICAL INFLAMMATION, INCREASED OXIDATIVE STRESS AND OTHERS MAY AFFECT THE HUMAN EPIGENOME. IN ADDITION, ANIMAL STUDIES HAVE SUGGESTED A POSSIBLE LINK BETWEEN NUTRITION AND ENVIRONMENTAL EXPOSURE DURING THE PERICONCEPTIONAL PERIOD AND EPIGENETIC CHANGES IN THE EXPRESSION OF MAJOR GENES IMPLICATED IN KIDNEY ORGANOGENESIS; THESE CHANGES RESULT IN A DIMINISHED NUMBER OF NEPHRONS IN THE DEVELOPING KIDNEY, WHICH PREDISPOSES TO AN INCREASED RISK FOR HYPERTENSION AND CHRONIC KIDNEY DISEASE IN FUTURE LIFE. THE UNDERSTANDING OF THE ROLE OF EPIGENETIC PHENOMENA IN THE PATHOGENESIS OF CHRONIC KIDNEY DISEASE OPENS NEW AVENUES FOR FUTURE THERAPEUTIC STRATEGIES, THROUGH THE DEVELOPMENT OF PHARMACEUTICAL AGENTS THAT TARGET DIRECTLY WITH THE CHANGES IN THE HUMAN EPIGENOME. SUCH EPIGENETIC DRUGS ARE ALREADY IN CLINICAL USE FOR THE TREATMENT OF CANCER AS WELL AS UNDER INVESTIGATION FOR THE USE IN OTHER DISEASES. THIS REVIEW WILL SUMMARIZE THE EXISTING DATA ON THE LINK BETWEEN EPIGENETIC MECHANISMS AND CHRONIC UREMIC MILIEU, AS WELL AS THE PROMISING RESULTS OF ONGOING RESEARCH IN THE FIELD OF EPIGENETIC DRUGS THAT COULD REPRESENT ADDITIONAL OPTIONS IN OUR THERAPEUTIC ARMAMENTARIUM FOR PATIENTS WITH CHRONIC KIDNEY DISEASE. 2011 3 1505 29 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 4 5376 42 RECENT DEVELOPMENTS IN EPIGENETICS OF ACUTE AND CHRONIC KIDNEY DISEASES. THE GROWING EPIDEMIC OF OBESITY AND DIABETES, THE AGING POPULATION AS WELL AS PREVALENCE OF DRUG ABUSE HAS LED TO SIGNIFICANT INCREASES IN THE RATES OF THE CLOSELY ASSOCIATED ACUTE AND CHRONIC KIDNEY DISEASES, INCLUDING DIABETIC NEPHROPATHY. FURTHERMORE, EVIDENCE SHOWS THAT PARENTAL BEHAVIOR AND DIET CAN AFFECT THE PHENOTYPE OF SUBSEQUENT GENERATIONS VIA EPIGENETIC TRANSMISSION MECHANISMS. THESE DATA SUGGEST A STRONG INFLUENCE OF THE ENVIRONMENT ON DISEASE SUSCEPTIBILITY AND THAT, APART FROM GENETIC SUSCEPTIBILITY, EPIGENETIC MECHANISMS NEED TO BE EVALUATED TO GAIN CRITICAL NEW INFORMATION ABOUT KIDNEY DISEASES. EPIGENETICS IS THE STUDY OF PROCESSES THAT CONTROL GENE EXPRESSION AND PHENOTYPE WITHOUT ALTERATIONS IN THE UNDERLYING DNA SEQUENCE. EPIGENETIC MODIFICATIONS, INCLUDING CYTOSINE DNA METHYLATION AND COVALENT POST-TRANSLATIONAL MODIFICATIONS OF HISTONES IN CHROMATIN, ARE PART OF THE EPIGENOME, THE INTERFACE BETWEEN THE STABLE GENOME AND THE VARIABLE ENVIRONMENT. THIS DYNAMIC EPIGENETIC LAYER RESPONDS TO EXTERNAL ENVIRONMENTAL CUES TO INFLUENCE THE EXPRESSION OF GENES ASSOCIATED WITH DISEASE STATES. THE FIELD OF EPIGENETICS HAS SEEN REMARKABLE GROWTH IN THE PAST FEW YEARS WITH SIGNIFICANT ADVANCES IN BASIC BIOLOGY, CONTRIBUTIONS TO HUMAN DISEASE, AS WELL AS EPIGENOMICS TECHNOLOGIES. FURTHER UNDERSTANDING OF HOW THE RENAL CELL EPIGENOME IS ALTERED BY METABOLIC AND OTHER STIMULI CAN YIELD NOVEL NEW INSIGHTS INTO THE PATHOGENESIS OF KIDNEY DISEASES. IN THIS REVIEW, WE HAVE DISCUSSED THE CURRENT KNOWLEDGE ON THE ROLE OF EPIGENETIC MECHANISMS (PRIMARILY DNAME AND HISTONE MODIFICATIONS) IN ACUTE AND CHRONIC KIDNEY DISEASES, AND THEIR TRANSLATIONAL POTENTIAL TO IDENTIFY MUCH NEEDED NEW THERAPIES. 2015 5 5364 43 RECENT ADVANCES IN EPIGENETICS OF AGE-RELATED KIDNEY DISEASES. RENAL AGING HAS ATTRACTED INCREASING ATTENTION IN TODAY'S AGING SOCIETY, AS ELDERLY PEOPLE WITH ADVANCED AGE ARE MORE SUSCEPTIBLE TO VARIOUS KIDNEY DISORDERS SUCH AS ACUTE KIDNEY INJURY (AKI) AND CHRONIC KIDNEY DISEASE (CKD). THERE IS NO CLEAR-CUT UNIVERSAL MECHANISM FOR IDENTIFYING AGE-RELATED KIDNEY DISEASES, AND THEREFORE, THEY POSE A CONSIDERABLE MEDICAL AND PUBLIC HEALTH CHALLENGE. EPIGENETICS REFERS TO THE STUDY OF HERITABLE MODIFICATIONS IN THE REGULATION OF GENE EXPRESSION THAT DO NOT REQUIRE CHANGES IN THE UNDERLYING GENOMIC DNA SEQUENCE. A VARIETY OF EPIGENETIC MODIFIERS SUCH AS HISTONE DEACETYLASES (HDAC) INHIBITORS AND DNA METHYLTRANSFERASE (DNMT) INHIBITORS HAVE BEEN PROPOSED AS POTENTIAL BIOMARKERS AND THERAPEUTIC TARGETS IN NUMEROUS FIELDS INCLUDING CARDIOVASCULAR DISEASES, IMMUNE SYSTEM DISEASE, NERVOUS SYSTEM DISEASES, AND NEOPLASMS. ACCUMULATING EVIDENCE IN RECENT YEARS INDICATES THAT EPIGENETIC MODIFICATIONS HAVE BEEN IMPLICATED IN RENAL AGING. HOWEVER, NO PREVIOUS SYSTEMATIC REVIEW HAS BEEN PERFORMED TO SYSTEMATICALLY GENERALIZE THE RELATIONSHIP BETWEEN EPIGENETICS AND AGE-RELATED KIDNEY DISEASES. IN THIS REVIEW, WE AIM TO SUMMARIZE THE RECENT ADVANCES IN EPIGENETIC MECHANISMS OF AGE-RELATED KIDNEY DISEASES AS WELL AS DISCUSS THE APPLICATION OF EPIGENETIC MODIFIERS AS POTENTIAL BIOMARKERS AND THERAPEUTIC TARGETS IN THE FIELD OF AGE-RELATED KIDNEY DISEASES. IN SUMMARY, THE MAIN TYPES OF EPIGENETIC PROCESSES INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS, NON-CODING RNA (NCRNA) MODULATION HAVE ALL BEEN IMPLICATED IN THE PROGRESSION OF AGE-RELATED KIDNEY DISEASES, AND THERAPEUTIC TARGETING OF THESE PROCESSES WILL YIELD NOVEL THERAPEUTIC STRATEGIES FOR THE PREVENTION AND/OR TREATMENT OF AGE-RELATED KIDNEY DISEASES. 2022 6 3826 36 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 7 2609 37 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 8 2195 37 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 5660 36 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 10 462 29 ARE ALTERATIONS IN DNA METHYLATION RELATED TO CKD DEVELOPMENT? THE MODIFICATIONS IN GENOMIC DNA METHYLATION ARE INVOLVED IN THE REGULATION OF NORMAL AND PATHOLOGICAL CELLULAR PROCESSES. THE EPIGENETIC REGULATION STIMULATES BIOLOGICAL PLASTICITY AS AN ADAPTIVE RESPONSE TO VARIATIONS IN ENVIRONMENTAL FACTORS. THE ROLE OF EPIGENETIC CHANGES IS VITAL FOR THE DEVELOPMENT OF SOME DISEASES, INCLUDING ATHEROGENESIS, CANCERS, AND CHRONIC KIDNEY DISEASE (CKD). THE RESULTS OF STUDIES PRESENTED IN THIS REVIEW HAVE SUGGESTED THAT ALTERED DNA METHYLATION CAN MODULATE THE EXPRESSION OF PRO-INFLAMMATORY AND PRO-FIBROTIC GENES, AS WELL THOSE ESSENTIAL FOR KIDNEY DEVELOPMENT AND FUNCTION, THUS STIMULATING RENAL DISEASE PROGRESSION. ABNORMALLY INCREASED HOMOCYSTEINE, HYPOXIA, AND INFLAMMATION HAVE BEEN SUGGESTED TO ALTER EPIGENETIC REGULATION OF GENE EXPRESSION IN CKD. STUDIES OF RENAL SAMPLES HAVE DEMONSTRATED THE RELATIONSHIP BETWEEN VARIATIONS IN DNA METHYLATION AND FIBROSIS AND VARIATIONS IN ESTIMATED GLOMERULAR FILTRATION RATE (EGFR) IN HUMAN CKD. THE UNRAVELLING OF THE GENETIC-EPIGENETIC PROFILE WOULD ENHANCE OUR UNDERSTANDING OF PROCESSES UNDERLYING THE DEVELOPMENT OF CKD. THE UNDERSTANDING OF MULTIFACETED RELATIONSHIP BETWEEN DNA METHYLATION, GENES EXPRESSION, AND DISEASE DEVELOPMENT AND PROGRESSION COULD IMPROVE THE ABILITY TO IDENTIFY INDIVIDUALS AT RISK OF CKD AND ENABLE THE CHOICE OF APPROPRIATE DISEASE MANAGEMENT. 2022 11 2333 35 EPIGENETIC REGULATION OF INFLAMMATION: THE METABOLOMICS CONNECTION. EPIGENETIC FACTORS ARE CONSIDERED THE REGULATOR OF COMPLEX MACHINERY BEHIND INFLAMMATORY DISORDERS AND SIGNIFICANTLY CONTRIBUTED TO THE EXPRESSION OF INFLAMMATION-ASSOCIATED GENES. EPIGENETIC MODIFICATIONS MODULATE VARIATION IN THE EXPRESSION PATTERN OF TARGET GENES WITHOUT AFFECTING THE DNA SEQUENCE. THE CURRENT KNOWLEDGE OF EPIGENETIC RESEARCH FOCUSED ON THEIR ROLE IN THE PATHOGENESIS OF VARIOUS INFLAMMATORY DISEASES THAT CAUSES MORBIDITY AND MORTALITY WORLDWIDE. INFLAMMATORY DISEASES ARE CATEGORIZED AS ACUTE AND CHRONIC BASED ON THE DISEASE SEVERITY AND ARE REGULATED BY THE EXPRESSION PATTERN OF VARIOUS GENES. HENCE, UNDERSTANDING THE ROLE OF EPIGENETIC MODIFICATIONS DURING INFLAMMATION PROGRESSION WILL CONTRIBUTE TO THE DISEASE OUTCOMES AND THERAPEUTIC APPROACHES. THIS REVIEW ALSO FOCUSES ON THE METABOLOMICS APPROACH ASSOCIATED WITH THE STUDY OF INFLAMMATORY DISORDERS. INFLAMMATORY RESPONSES AND METABOLIC REGULATION ARE HIGHLY INTEGRATED AND VARIOUS ADVANCED TECHNIQUES ARE ADOPTED TO STUDY THE METABOLIC SIGNATURE MOLECULES. HERE WE DISCUSS SEVERAL METABOLOMICS APPROACHES USED TO LINK INFLAMMATORY DISORDERS AND EPIGENETIC CHANGES. WE PROPOSED THAT DECIPHERING THE MECHANISM BEHIND THE INFLAMMATION-METABOLISM LOOP MAY HAVE IMMENSE IMPORTANCE IN BIOMARKERS RESEARCH AND MAY ACT AS A PRINCIPAL COMPONENT IN DRUG DISCOVERY AS WELL AS THERAPEUTIC APPLICATIONS. 2022 12 2163 34 EPIGENETIC MECHANISMS IN DIABETIC VASCULAR COMPLICATIONS. THERE HAS BEEN A RAPID INCREASE IN THE INCIDENCE OF DIABETES AS WELL THE ASSOCIATED VASCULAR COMPLICATIONS. BOTH GENETIC AND ENVIRONMENTAL FACTORS HAVE BEEN IMPLICATED IN THESE PATHOLOGIES. INCREASING EVIDENCE SUGGESTS THAT EPIGENETIC FACTORS PLAY A KEY ROLE IN THE COMPLEX INTERPLAY BETWEEN GENES AND THE ENVIRONMENT. ACTIONS OF MAJOR PATHOLOGICAL MEDIATORS OF DIABETES AND ITS COMPLICATIONS SUCH AS HYPERGLYCAEMIA, OXIDANT STRESS, AND INFLAMMATORY FACTORS CAN LEAD TO DYSREGULATED EPIGENETIC MECHANISMS THAT AFFECT CHROMATIN STRUCTURE AND GENE EXPRESSION. FURTHERMORE, PERSISTENCE OF THIS ALTERED STATE OF THE EPIGENOME MAY BE THE UNDERLYING MECHANISM CONTRIBUTING TO A 'METABOLIC MEMORY' THAT RESULTS IN CHRONIC INFLAMMATION AND VASCULAR DYSFUNCTION IN DIABETES EVEN AFTER ACHIEVING GLYCAEMIC CONTROL. FURTHER EXAMINATION OF EPIGENETIC MECHANISMS BY ALSO TAKING ADVANTAGE OF RECENTLY DEVELOPED NEXT-GENERATION SEQUENCING TECHNOLOGIES CAN PROVIDE NOVEL INSIGHTS INTO THE PATHOLOGY OF DIABETES AND ITS COMPLICATIONS AND LEAD TO THE DISCOVERY OF MUCH NEEDED NEW DRUG TARGETS FOR THESE DISEASES. IN THIS REVIEW, WE HIGHLIGHT THE ROLE OF EPIGENETICS IN DIABETES AND ITS VASCULAR COMPLICATIONS, AND RECENT TECHNOLOGICAL ADVANCES THAT HAVE SIGNIFICANTLY ACCELERATED THE FIELD. 2011 13 607 36 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 4719 36 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 15 6204 41 THE INFLUENCE OF EPIGENETICS AND INFLAMMATION ON CARDIOMETABOLIC RISKS. CARDIOMETABOLIC DISEASES INCLUDE METABOLIC SYNDROME, OBESITY, TYPE 2 DIABETES MELLITUS, AND HYPERTENSION. EPIGENETIC MODIFICATIONS PARTICIPATE IN CARDIOMETABOLIC DISEASES THROUGH SEVERAL PATHWAYS, INCLUDING INFLAMMATION, VASCULAR DYSFUNCTION, AND INSULIN RESISTANCE. EPIGENETIC MODIFICATIONS, WHICH ENCOMPASS ALTERATIONS TO GENE EXPRESSION WITHOUT MUTATING THE DNA SEQUENCE, HAVE GAINED MUCH ATTENTION IN RECENT YEARS, SINCE THEY HAVE BEEN CORRELATED WITH CARDIOMETABOLIC DISEASES AND MAY BE TARGETED FOR THERAPEUTIC INTERVENTIONS. EPIGENETIC MODIFICATIONS ARE GREATLY INFLUENCED BY ENVIRONMENTAL FACTORS, SUCH AS DIET, PHYSICAL ACTIVITY, CIGARETTE SMOKING, AND POLLUTION. SOME MODIFICATIONS ARE HERITABLE, INDICATING THAT THE BIOLOGICAL EXPRESSION OF EPIGENETIC ALTERATIONS MAY BE OBSERVED ACROSS GENERATIONS. MOREOVER, MANY PATIENTS WITH CARDIOMETABOLIC DISEASES PRESENT WITH CHRONIC INFLAMMATION, WHICH CAN BE INFLUENCED BY ENVIRONMENTAL AND GENETIC FACTORS. THE INFLAMMATORY ENVIRONMENT WORSENS THE PROGNOSIS OF CARDIOMETABOLIC DISEASES AND FURTHER INDUCES EPIGENETIC MODIFICATIONS, PREDISPOSING PATIENTS TO THE DEVELOPMENT OF OTHER METABOLISM-ASSOCIATED DISEASES AND COMPLICATIONS. A DEEPER UNDERSTANDING OF INFLAMMATORY PROCESSES AND EPIGENETIC MODIFICATIONS IN CARDIOMETABOLIC DISEASES IS NECESSARY TO IMPROVE OUR DIAGNOSTIC CAPABILITIES, PERSONALIZED MEDICINE APPROACHES, AND THE DEVELOPMENT OF TARGETED THERAPEUTIC INTERVENTIONS. FURTHER UNDERSTANDING MAY ALSO ASSIST IN PREDICTING DISEASE OUTCOMES, ESPECIALLY IN CHILDREN AND YOUNG ADULTS. THIS REVIEW DESCRIBES EPIGENETIC MODIFICATIONS AND INFLAMMATORY PROCESSES UNDERLYING CARDIOMETABOLIC DISEASES, AND FURTHER DISCUSSES ADVANCES IN THE RESEARCH FIELD WITH A FOCUS ON SPECIFIC POINTS FOR INTERVENTIONAL THERAPY. 2023 16 6113 37 THE EPIGENETIC CONDUCTOR: A GENOMIC ORCHESTRATOR IN CHRONIC KIDNEY DISEASE COMPLICATIONS? EPIGENETICS DEFINES THE CELLULARLY HERITABLE PROPERTIES OF GENOME FUNCTION, WHICH ARE NOT DIRECTLY ENCODED IN THE DNA PRIMARY SEQUENCE. THE UNDERLYING MECHANISMS ORCHESTRATE CELL IDENTITY AND MEMORY AND ARE TARGETS FOR EXTERNAL AND INTERNAL ENVIRONMENTAL INFLUENCES. IT BECOMES INCREASINGLY CLEAR THAT GENETIC AND EPIGENETIC FACTORS ARE COMPLETELY INTERDEPENDENT FOR HOMEOSTASIS. SUBSEQUENTLY, THE SAME IS CERTAINLY TRUE FOR DISEASE. OUR UNDERSTANDING OF EPIGENETIC MECHANISMS IN CHRONIC KIDNEY DISEASE (CKD) IS STILL LAGGING, AND FURTHER STUDIES ARE NEEDED TO UNDERSTAND THE IMPORTANCE OF, E.G., ABERRANT DNA METHYLATION IN RELATION TO THE UREMIC IMPACT ON THE FUNCTIONAL GENOME, ORGANISMAL METABOLISM AND ASSOCIATED PREMATURE VASCULAR DISEASE. MORE RESEARCH IN THIS FIELD WILL ALSO HELP US UNDERSTAND THE LINKS BETWEEN ALTERED GENE REGULATION OF SPECIFIC GENES BY THE UREMIC ENVIRONMENT VIA EPIGENETIC MECHANISMS, AND INITIATION AND PROGRESSION OF ATHEROSCLEROSIS. THE DYNAMIC NATURE OF EPIGENETIC MECHANISMS PROMPTS THERAPEUTIC INVESTIGATIONS IN CKD, TARGETING THE EPIGENOME WITH EPIGENETIC DRUGS. THE IMPORTANCE OF 1-CARBON METABOLISM FOR EPIGENETIC MODIFICATIONS SUGGESTS THAT SPECIFIC DIETS MAY ALSO PROVE TO PLAY AN IMPORTANT PART AS EFFICIENT REMEDIES IN CKD AND ASSOCIATED ATHEROSCLEROTIC PATHOLOGIES. 2009 17 931 32 CHRONIC KIDNEY DISEASE IN CHILDREN AND THE ROLE OF EPIGENETICS: FUTURE THERAPEUTIC TRAJECTORIES. GLOBAL DIFFERENCES IN THE OBSERVED CAUSES OF CHRONIC KIDNEY DISEASE (CKD) IN CHILDREN ARE WELL DOCUMENTED AND ARE ATTRIBUTED TO DISSIMILARITIES IN CLIME, RACE, HEREDITARY, AND ANCESTRY. THUS, FAMILIAL CLUSTERING AND DISPARITIES IN CKD PREVALENCE RATES ACROSS ETHNIC AND RACIAL GROUPS INDICATE THAT THE PROGRESSION OF RENAL DISEASE HAS A STRONG GENETIC COMPONENT. MAMMALIAN STUDIES HAVE DEMONSTRATED A FEASIBLE NEXUS BETWEEN NUTRITION AND NON-GENETIC EXPOSURE (AROUND THE TIME OF CONCEPTION AND IN EPIGENETIC CHANGES) IN THE EXPRESSION OF MAJOR GENES IDENTIFIED IN RENAL ORGANOGENESIS. THE MAJOR CONSEQUENCE IS A REDUCTION IN THE NUMBER OF NEPHRONS, WITH SUBSEQUENT PREDISPOSITION TO HYPERTENSION AND CKD. IDENTIFYING THESE EPIGENETIC CHANGES IS CRUCIAL (DUE TO THEIR POTENTIALLY REVERSIBLE NATURE), AS THEY MAY SERVE AS FUTURE THERAPEUTIC TARGETS TO PREVENT KIDNEY FIBROSIS AND CKD. DESPITE PROGRESS IN THE FIELD OF EPIGENETICS IN ONCOLOGY, RESEARCH IN OTHER SUBSPECIALTIES OF MEDICINE IS LARGELY EXPERIMENTAL WITH FEW EXISTING STUDIES REGARDING THE CLINICAL IMPLICATION OF EPIGENETICS IN RENAL DISEASE. THERAPEUTIC TRAJECTORIES FOR CKD IN CHILDREN BASED ON THE INFLUENCE OF EPIGENETICS MAY EVENTUALLY REVOLUTIONIZE THE MANAGEMENT OF THIS DISEASE. THE AIM OF THE CURRENT NARRATIVE REVIEW IS TO APPRAISE THE ROLE OF EPIGENETICS IN CKD, AND HIGHLIGHT THE POTENTIAL FUTURE THERAPEUTIC PATHWAYS. 2016 18 859 27 CHROMATIN DYNAMICS IN KIDNEY DEVELOPMENT AND FUNCTION. EPIGENETIC MECHANISMS ARE FUNDAMENTAL KEY FEATURES OF DEVELOPING CELLS CONNECTING DEVELOPMENTAL REGULATORY FACTORS TO CHROMATIN MODIFICATION. CHANGES IN THE ENVIRONMENT DURING RENAL DEVELOPMENT CAN HAVE LONG-LASTING EFFECTS ON THE PERMANENT TISSUE STRUCTURE AND THE LEVEL OF EXPRESSION OF IMPORTANT FUNCTIONAL GENES. THESE CHANGES ARE BELIEVED TO CONTRIBUTE TO KIDNEY DISEASE OCCURRENCE AND PROGRESSION. ALTHOUGH THE MECHANISMS OF EARLY PATTERNING AND CELL FATE HAVE BEEN WELL DESCRIBED FOR RENAL DEVELOPMENT, LITTLE IS KNOWN ABOUT ASSOCIATED EPIGENETIC MODIFICATIONS AND THEIR IMPACT ON HOW GENES INTERACT TO SPECIFY THE RENAL EPITHELIAL CELLS OF NEPHRONS AND HOW THIS SPECIFICATION IS RELEVANT TO MAINTAINING NORMAL RENAL FUNCTION. A BETTER UNDERSTANDING OF THE RENAL CELL-SPECIFIC EPIGENETIC MODIFICATIONS AND THE INTERACTION OF DIFFERENT CELL TYPES TO FORM THIS HIGHLY COMPLEX ORGAN WILL NOT ONLY HELP TO BETTER UNDERSTAND DEVELOPMENTAL DEFECTS AND EARLY LOSS OF KIDNEY FUNCTION IN CHILDREN, BUT ALSO HELP TO UNDERSTAND AND IMPROVE CHRONIC DISEASE PROGRESSION, CELL REGENERATION AND RENAL AGING. 2014 19 2542 38 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 20 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