1 4668 102 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 2 2195 41 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 3 3826 40 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 4 2542 41 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 5 607 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 6 5660 40 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 7 4250 39 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 8 1597 35 DNA METHYLATION REGULATED GENE EXPRESSION IN ORGAN FIBROSIS. DNA METHYLATION IS A MAJOR EPIGENETIC MECHANISM TO REGULATE GENE EXPRESSION. EPIGENETIC REGULATION, INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND RNA INTERFERENCE, RESULTS IN HERITABLE CHANGES IN GENE EXPRESSION INDEPENDENT OF ALTERATIONS IN DNA SEQUENCE. EPIGENETIC REGULATION OFTEN OCCURS IN RESPONSE TO AGING AND ENVIRONMENT STIMULI, INCLUDING EXPOSURES AND DIET. STUDIES HAVE SHOWN THAT DNA METHYLATION IS CRITICAL IN THE PATHOGENESIS OF FIBROSIS INVOLVING MULTIPLE ORGAN SYSTEMS, CONTRIBUTING TO SIGNIFICANT MORBIDITY AND MORTALITY. ABERRANT DNA METHYLATION CAN SILENCE OR ACTIVATE GENE EXPRESSION PATTERNS THAT DRIVE THE FIBROSIS PROCESS. FIBROSIS IS A PATHOLOGICAL WOUND HEALING PROCESS IN RESPONSE TO CHRONIC INJURY. IT IS CHARACTERIZED BY EXCESSIVE EXTRACELLULAR MATRIX PRODUCTION AND ACCUMULATION, WHICH EVENTUALLY AFFECTS ORGAN ARCHITECTURE AND RESULTS IN ORGAN FAILURE. FIBROSIS CAN AFFECT A WIDE RANGE OF ORGANS, INCLUDING THE HEART AND LUNGS, AND HAVE LIMITED THERAPEUTIC OPTIONS. DNA METHYLATION, LIKE OTHER EPIGENETIC PROCESS, IS REVERSIBLE, THEREFORE REGARDED AS ATTRACTIVE THERAPEUTIC INTERVENTIONS. ALTHOUGH EPIGENETIC MECHANISMS ARE HIGHLY INTERACTIVE AND OFTEN REINFORCING, THIS REVIEW DISCUSSES DNA METHYLATION-DEPENDENT MECHANISMS IN THE PATHOGENESIS OF ORGAN FIBROSIS, WITH FOCUS ON CARDIAC AND PULMONARY FIBROSIS. WE DISCUSS SPECIFIC PRO- AND ANTI-FIBROTIC GENES AND PATHWAYS REGULATED BY DNA METHYLATION IN ORGAN FIBROSIS; WE FURTHER HIGHLIGHT THE POTENTIAL BENEFITS AND SIDE-EFFECTS OF EPIGENETIC THERAPIES IN FIBROTIC DISORDERS. 2017 9 2286 36 EPIGENETIC REGULATION IN KIDNEY TRANSPLANTATION. KIDNEY TRANSPLANTATION IS A STANDARD CARE FOR END STAGE RENAL DISEASE, BUT IT IS ALSO ASSOCIATED WITH A COMPLEX PATHOGENESIS INCLUDING ISCHEMIA-REPERFUSION INJURY, INFLAMMATION, AND DEVELOPMENT OF FIBROSIS. OVER THE PAST DECADE, ACCUMULATING EVIDENCE HAS SUGGESTED A ROLE OF EPIGENETIC REGULATION IN KIDNEY TRANSPLANTATION, INVOLVING DNA METHYLATION, HISTONE MODIFICATION, AND VARIOUS KINDS OF NON-CODING RNAS. HERE, WE ANALYZE THESE RECENT STUDIES SUPPORTING THE ROLE OF EPIGENETIC REGULATION IN DIFFERENT PATHOLOGICAL PROCESSES OF KIDNEY TRANSPLANTATION, I.E., ISCHEMIA-REPERFUSION INJURY, ACUTE REJECTION, AND CHRONIC GRAFT PATHOLOGIES INCLUDING RENAL INTERSTITIAL FIBROSIS. FURTHER INVESTIGATION OF EPIGENETIC ALTERATIONS, THEIR PATHOLOGICAL ROLES AND UNDERLYING MECHANISMS IN KIDNEY TRANSPLANTATION MAY LEAD TO NEW STRATEGIES FOR THE DISCOVERY OF NOVEL DIAGNOSTIC BIOMARKERS AND THERAPEUTIC INTERVENTIONS. 2022 10 859 26 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 11 2532 40 EPIGENETICS IN ATHEROSCLEROSIS AND INFLAMMATION. ATHEROSCLEROSIS IS A MULTIFACTORIAL DISEASE WITH A SEVERE BURDEN ON WESTERN SOCIETY. RECENT INSIGHTS INTO THE PATHOGENESIS OF ATHEROSCLEROSIS UNDERSCORE THE IMPORTANCE OF CHRONIC INFLAMMATION IN BOTH THE INITIATION AND PROGRESSION OF VASCULAR REMODELLING. EXPRESSION OF IMMUNOREGULATORY MOLECULES BY VASCULAR WALL COMPONENTS WITHIN THE ATHEROSCLEROTIC LESIONS IS ACCORDINGLY THOUGHT TO CONTRIBUTE TO THE ONGOING INFLAMMATORY PROCESS. BESIDES GENE REGULATORY PROTEINS (TRANSCRIPTION FACTORS), EPIGENETIC MECHANISMS ALSO PLAY AN ESSENTIAL AND FUNDAMENTAL ROLE IN THE TRANSCRIPTIONAL CONTROL OF GENE EXPRESSION. THESE EPIGENETIC MECHANISMS CHANGE THE ACCESSIBILITY OF CHROMATIN BY DNA METHYLATION AND HISTONE MODIFICATIONS. EPIGENETIC MODULATORS ARE THUS CRITICALLY INVOLVED IN THE REGULATION OF VASCULAR, IMMUNE AND TISSUE-SPECIFIC GENE EXPRESSION WITHIN THE ATHEROSCLEROTIC LESION. IMPORTANTLY, EPIGENETIC PROCESSES ARE REVERSIBLE AND MAY PROVIDE AN EXCELLENT THERAPEUTIC TARGET. THE CONCEPT OF EPIGENETIC REGULATION IS GRADUALLY BEING RECOGNIZED AS AN IMPORTANT FACTOR IN THE PATHOGENESIS OF ATHEROSCLEROSIS. RECENT RESEARCH PROVIDES AN ESSENTIAL LINK BETWEEN INFLAMMATION AND REPROGRAMMING OF THE EPIGENOME. IN THIS REVIEW WE THEREFORE DISCUSS THE BASIS OF EPIGENETIC REGULATION - AND THE CONTRIBUTION THEREOF IN THE REGULATION OF INFLAMMATORY PROCESSES IN GENERAL AND DURING ATHEROSCLEROSIS IN PARTICULAR. MOREOVER WE HIGHLIGHT POTENTIAL THERAPEUTIC INTERVENTIONS BASED ON EPIGENETIC MECHANISMS. 2010 12 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 13 1604 35 DNA METHYLATION SUSTAINS "INFLAMED" MEMORY OF PERIPHERAL IMMUNE CELLS AGGRAVATING KIDNEY INFLAMMATORY RESPONSE IN CHRONIC KIDNEY DISEASE. THE INCIDENCE OF CHRONIC KIDNEY DISEASE (CKD) HAS RAPIDLY INCREASED IN THE PAST DECADES. A PROGRESSIVE LOSS OF KIDNEY FUNCTION CHARACTERIZES A PART OF CKD EVEN WITH INTENSIVE SUPPORTIVE TREATMENT. IRRESPECTIVE OF ITS ETIOLOGY, CKD PROGRESSION IS GENERALLY ACCOMPANIED WITH THE DEVELOPMENT OF CHRONIC KIDNEY INFLAMMATION THAT IS PATHOLOGICALLY FEATURED BY THE LOW-GRADE BUT CHRONIC ACTIVATION OF RECRUITED IMMUNE CELLS. CUMULATIVE EVIDENCE SUPPORT THAT ABERRANT DNA METHYLATION PATTERN OF DIVERSE PERIPHERAL IMMUNE CELLS, INCLUDING T CELLS AND MONOCYTES, IS CLOSELY ASSOCIATED WITH CKD DEVELOPMENT IN MANY CHRONIC DISEASE SETTINGS. THE CHANGE OF DNA METHYLATION PROFILE CAN SUSTAIN FOR A LONG TIME AND AFFECT THE FUTURE GENES EXPRESSION IN THE CIRCULATING IMMUNE CELLS EVEN AFTER THEY MIGRATE FROM THE CIRCULATION INTO THE INVOLVED KIDNEY. IT IS OF CLINICAL INTEREST TO REVEAL THE UNDERLYING MECHANISM OF HOW ALTERED DNA METHYLATION REGULATES THE INTENSITY AND THE TIME LENGTH OF THE INFLAMMATORY RESPONSE IN THE RECRUITED EFFECTOR CELLS. WE AND OTHERS RECENTLY DEMONSTRATED THAT ALTERED DNA METHYLATION OCCURS IN PERIPHERAL IMMUNE CELLS AND PROFOUNDLY CONTRIBUTES TO CKD DEVELOPMENT IN SYSTEMIC CHRONIC DISEASES, SUCH AS DIABETES AND HYPERTENSION. THIS REVIEW WILL SUMMARIZE THE CURRENT FINDINGS ABOUT THE INFLUENCE OF ABERRANT DNA METHYLATION ON CIRCULATING IMMUNE CELLS AND HOW IT POTENTIALLY DETERMINES THE OUTCOME OF CKD. 2021 14 2283 33 EPIGENETIC REGULATION IN FIBROSIS PROGRESS. FIBROSIS, A COMMON PROCESS OF CHRONIC INFLAMMATORY DISEASES, IS DEFINED AS A REPAIR RESPONSE DISORDER WHEN ORGANS UNDERGO CONTINUOUS DAMAGE, ULTIMATELY LEADING TO SCAR FORMATION AND FUNCTIONAL FAILURE. AROUND THE WORLD, FIBROTIC DISEASES CAUSE HIGH MORTALITY, UNFORTUNATELY, WITH LIMITED TREATMENT MEANS IN CLINICAL PRACTICE. WITH THE DEVELOPMENT AND APPLICATION OF DEEP SEQUENCING TECHNOLOGY, COMPREHENSIVELY EXPLORING THE EPIGENETIC MECHANISM IN FIBROSIS HAS BEEN ALLOWED. EXTENSIVE REMODELING OF EPIGENETICS CONTROLLING VARIOUS CELLS PHENOTYPE AND MOLECULAR MECHANISMS INVOLVED IN FIBROGENESIS WAS SUBSEQUENTLY VERIFIED. IN THIS REVIEW, WE SUMMARIZE THE REGULATORY MECHANISMS OF DNA METHYLATION, HISTONE MODIFICATION, NONCODING RNAS (NCRNAS) AND N6-METHYLADENOSINE (M6A) MODIFICATION IN ORGAN FIBROSIS, FOCUSING ON HEART, LIVER, LUNG AND KIDNEY. ADDITIONALLY, WE EMPHASIZE THE DIVERSITY OF EPIGENETICS IN THE CELLULAR AND MOLECULAR MECHANISMS RELATED TO FIBROSIS. FINALLY, THE POTENTIAL AND PROSPECT OF TARGETED THERAPY FOR FIBROSIS BASED ON EPIGENETIC IS DISCUSSED. 2021 15 2341 35 EPIGENETIC REGULATION OF LIVER FIBROSIS. FIBROSIS IS A COMMON AND IMPORTANT PATHOLOGY ASSOCIATED WITH PROGRESSIVE CHRONIC LIVER DISEASES AND UNDERLIES THE DEVELOPMENT OF CIRRHOSIS AND HEPATOCELLULAR CARCINOMA. RESEARCH INTO THE MOLECULAR REGULATION OF FIBROSIS HAS DISCOVERED THAT IT IS UNDER THE CONTROL OF A NUMBER OF EPIGENETIC MECHANISMS INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND THE ACTIVITIES OF NON-CODING RNAS. A DEEPER UNDERSTANDING OF HOW EPIGENETIC REGULATORS SUCH AS DNA METHYLTRANSERASES, METHYL-DNA BINDING PROTEINS, HISTONE MODIFYING ENZYMES AND REGULATORY RNA MOLECULES IMPACT ON THE FIBROGENIC PROCESS IS EXPECTED TO RESULT IN NEW BIOMARKERS FOR DISEASE PROGRESSION AS WELL AS NOVEL THERAPEUTIC TARGETS. THE AIM OF THIS MINI-REVIEW IS TO BRIEFLY INTRODUCE THE READER TO THE MAJOR EPIGENETIC REGULATORS SO FAR IDENTIFIED AS BEING IMPLICATED IN FIBROSIS. 2015 16 462 37 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 17 5258 32 PROGRESSION OF TUBULOINTERSTITIAL FIBROSIS AND THE CHRONIC KIDNEY DISEASE PHENOTYPE - ROLE OF RISK FACTORS AND EPIGENETICS. ALTHOUGH THE KIDNEY HAS CAPACITY TO REPAIR AFTER MILD INJURY, ONGOING OR SEVERE DAMAGE RESULTS IN SCARRING (FIBROSIS) AND AN ASSOCIATED PROGRESSIVE LOSS OF KIDNEY FUNCTION. HOWEVER, DESPITE ITS UNIVERSAL SIGNIFICANCE, EVIDENCE HIGHLIGHTS A POPULATION BASED HETEROGENEITY IN THE TRAJECTORY OF CHRONIC KIDNEY DISEASE (CKD) IN THESE PATIENTS. TO EXPLAIN THE HETEROGENEITY OF THE CKD PHENOTYPE REQUIRES AN UNDERSTANDING OF THE RELEVANT RISK FACTORS FOR FIBROSIS. THESE FACTORS INCLUDE BOTH THE EXTRINSIC NATURE OF INJURY, AND INTRINSIC FACTORS SUCH AS AGE, GENDER, GENETICS, AND PERPETUAL ACTIVATION OF FIBROBLASTS THROUGH PRIMING. IN MANY CASES AN ADDITIONAL LEVEL OF REGULATION IS PROVIDED BY EPIGENETIC MECHANISMS WHICH INTEGRATE THE VARIOUS PRO-FIBROTIC AND ANTI-FIBROTIC TRIGGERS IN FIBROGENESIS. IN THIS REVIEW WE THEREFORE EXAMINE THE VARIOUS MOLECULAR AND STRUCTURAL CHANGES OF FIBROSIS, AND HOW THEY ARE INFLUENCED BY EXTRINSIC AND INTRINSIC FACTORS. OUR AIM IS TO PROVIDE A UNIFYING HYPOTHESIS TO HELP EXPLAIN THE TRANSITION FROM ACUTE TO CKD. 2017 18 2579 25 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 1487 32 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 20 6377 36 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