1 931 119 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 2 2154 49 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 5376 41 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 4 3404 30 HOW EPIGENETICS IMPACTS ON HUMAN DISEASES. EPIGENETICS IS A RAPIDLY GROWING FIELD OF BIOLOGY THAT STUDIES THE CHANGES IN GENE EXPRESSION THAT ARE NOT DUE TO ALTERATIONS IN THE DNA SEQUENCE BUT RATHER THE CHEMICAL MODIFICATIONS OF DNA AND ITS ASSOCIATED PROTEINS. EPIGENETIC MECHANISMS CAN PROFOUNDLY INFLUENCE GENE EXPRESSION, CELL DIFFERENTIATION, TISSUE DEVELOPMENT, AND DISEASE SUSCEPTIBILITY. UNDERSTANDING EPIGENETIC CHANGES IS ESSENTIAL TO ELUCIDATE THE MECHANISMS UNDERLYING THE INCREASINGLY RECOGNIZED ROLE OF ENVIRONMENTAL AND LIFESTYLE FACTORS IN HEALTH AND DISEASE AND THE INTERGENERATIONAL TRANSMISSION OF PHENOTYPES. RECENT STUDIES SUGGEST EPIGENETICS MAY BE CRITICAL IN VARIOUS DISEASES, FROM CARDIOVASCULAR DISEASE AND CANCER TO NEURODEVELOPMENTAL AND NEURODEGENERATIVE DISORDERS. EPIGENETIC MODIFICATIONS ARE POTENTIALLY REVERSIBLE AND COULD PROVIDE NEW THERAPEUTIC AVENUES FOR TREATING THESE DISEASES USING EPIGENETIC MODULATORS. MOREOVER, EPIGENETICS PROVIDE INSIGHT INTO DISEASE PATHOGENESIS AND BIOMARKERS FOR DISEASE DIAGNOSIS AND RISK STRATIFICATION. NEVERTHELESS, EPIGENETIC INTERVENTIONS HAVE THE POTENTIAL FOR UNINTENDED CONSEQUENCES AND MAY POTENTIALLY LEAD TO INCREASED RISKS OF UNEXPECTED OUTCOMES, SUCH AS ADVERSE DRUG REACTIONS, DEVELOPMENTAL ABNORMALITIES, AND CANCER. THEREFORE, RIGOROUS STUDIES ARE ESSENTIAL TO MINIMIZE THE RISKS ASSOCIATED WITH EPIGENETIC THERAPIES AND TO DEVELOP SAFE AND EFFECTIVE INTERVENTIONS FOR IMPROVING HUMAN HEALTH. THIS ARTICLE PROVIDES A SYNTHETIC AND HISTORICAL VIEW OF THE ORIGIN OF EPIGENETICS AND SOME OF THE MOST RELEVANT ACHIEVEMENTS. 2023 5 2982 32 GENETIC CONSIDERATIONS IN PEDIATRIC CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IN CHILDREN IS AN IRREVERSIBLE PROCESS THAT, IN SOME CASES, MAY LEAD TO END-STAGE RENAL DISEASE. THE MAJORITY OF CHILDREN WITH CKD HAVE A CONGENITAL DISORDER OF THE KIDNEY OR UROLOGICAL TRACT ARISING FROM BIRTH. THERE IS STRONG EVIDENCE FOR BOTH A GENETIC AND EPIGENETIC COMPONENT TO PROGRESSION OF CKD. UTILIZATION OF GENE-MAPPING STRATEGIES, RANGING FROM GENOME-WIDE ASSOCIATION STUDIES TO SINGLE-NUCLEOTIDE POLYMORPHISM ANALYSIS, SERVES TO IDENTIFY POTENTIAL GENETIC VARIANTS THAT MAY LEND TO DISEASE VARIATION. GENOME-WIDE ASSOCIATION STUDIES EVALUATING POPULATION-BASED DATA HAVE IDENTIFIED DIFFERENT LOCI ASSOCIATED WITH CKD PROGRESSION. ANALYSIS OF SINGLE-NUCLEOTIDE POLYMORPHISMS ON AN INDIVIDUAL LEVEL SUGGESTS THAT SECONDARY SYSTEMIC SEQUELAE OF CKD ARE CLOSELY RELATED TO DYSFUNCTION OF THE CARDIOVASCULAR-INFLAMMATORY AXIS AND MAY LEAD TO ADVANCED CARDIOVASCULAR DISEASE THROUGH ABNORMAL VASCULAR CALCIFICATION AND ACTIVATION OF THE RENIN-ANGIOTENSIN SYSTEM. SIMILARLY, GENETIC VARIANTS AFFECTING CYTOKINE CONTROL, FIBROSIS, AND PARENCHYMAL DEVELOPMENT MAY MODULATE CKD THROUGH DEVELOPMENT AND ACCELERATION OF RENAL INTERSTITIAL FIBROSIS. EPIGENETIC STUDIES EVALUATE MODIFICATION OF THE GENOME THROUGH DNA METHYLATION, HISTONE MODIFICATION, OR RNA INTERFERENCE, WHICH MAY BE DIRECTLY INFLUENCED BY EXTERNAL OR ENVIRONMENTAL FACTORS DIRECTING GENOMIC EXPRESSION. LASTLY, IMPROVED UNDERSTANDING OF THE GENETIC AND EPIGENETIC CONTRIBUTION TO CKD PROGRESSION MAY ALLOW PROVIDERS TO IDENTIFY A POPULATION AT ACCELERATED RISK FOR DISEASE PROGRESSION AND APPLY NOVEL THERAPIES TARGETED AT THE GENETIC MECHANISM OF DISEASE. 2016 6 5364 36 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 7 6204 36 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 8 5660 32 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 9 5258 31 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 10 1060 32 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 11 2570 24 EPIGENETICS OF CHRONIC INFLAMMATORY DISEASES. CHRONIC, NONCOMMUNICABLE, AND INFLAMMATION-ASSOCIATED DISEASES REMAIN THE LARGEST CAUSE OF MORBIDITY AND MORTALITY GLOBALLY AND WITHIN THE UNITED STATES. THIS IS MAINLY DUE TO OUR LIMITED UNDERSTANDING OF THE MOLECULAR MECHANISMS THAT UNDERLIE THESE COMPLEX PATHOLOGIES. THE AVAILABLE EVIDENCE INDICATES THAT STUDIES OF EPIGENETICS (TRADITIONALLY DEFINED AS THE HERITABLE CHANGES TO GENE EXPRESSION THAT ARE INDEPENDENT OF CHANGES TO DNA) ARE SIGNIFICANTLY ADVANCING OUR KNOWLEDGE OF THESE INFLAMMATORY CONDITIONS. THIS REVIEW WILL FOCUS ON EPIGENETIC STUDIES OF THREE DISEASES, THAT ARE AMONG THE MOST BURDENSOME GLOBALLY: CARDIOVASCULAR DISEASE, THE NUMBER ONE CAUSE OF DEATHS WORLDWIDE, TYPE 2 DIABETES AND, ALZHEIMER'S DISEASE. THE CURRENT STATUS OF EPIGENETIC RESEARCH, INCLUDING THE ABILITY TO PREDICT DISEASE RISK, AND KEY PATHOPHYSIOLOGICAL DEFECTS ARE DISCUSSED. THE SIGNIFICANCE OF DEFINING THE CONTRIBUTION OF EPIGENETIC DEFECTS TO NONRESOLVING INFLAMMATION AND AGING, EACH ASSOCIATED WITH THESE DISEASES, IS HIGHLIGHTED, AS THESE ARE LIKELY TO PROVIDE NEW INSIGHTS INTO INFLAMMATORY DISEASE PATHOGENESIS. 2019 12 6001 34 THE ACUTE KIDNEY INJURY TO CHRONIC KIDNEY DISEASE TRANSITION: A POTENTIAL OPPORTUNITY TO IMPROVE CARE IN ACUTE KIDNEY INJURY. RECENT CONTROLLED TRIALS, EPIDEMIOLOGICAL ANALYSES AND BASIC RESEARCH STUDIES OFFER A COMPREHENSIVE VIEW OF THE SHORT AND LONG-TERM CLINICAL REPERCUSSION OF DE NOVO ACUTE KIDNEY INJURY OR AKI. WHILE MOST POST-AKI PATIENTS RECOVER THEIR BASELINE RENAL FUNCTION, A SIGNIFICANT NUMBER, APPROXIMATELY ~20% OF THOSE AFFECTED, WILL GO ON TO DEVELOP LONG TERM ILLNESS CHARACTERIZED BY AN INCREASE IN LATE STAGE CKD, CARDIOVASCULAR COMPLICATIONS, AND INCREASED DEATH RATES. WHEN AKI OCCURS IN HOSPITALIZED PATIENTS, SELECTED DEMOGRAPHIC AND LABORATORY RESULTS CAN BE INCORPORATED INTO RISK CALCULATORS THAT IDENTIFY THOSE AT HIGHER RISK FOR LONG-TERM COMPLICATIONS. THIS REVIEW TOUCHES ON SOME OF THE SALIENT EPIDEMIOLOGICAL STUDIES OF THE AKI TO CKD TRANSITION. IT ALSO FOCUSES ON CERTAIN RECENT ADVANCEMENTS IN OUR UNDERSTANDING OF THE BIOLOGICAL AND FUNCTIONAL IMPACT OF AKI ON THE RENAL TUBULE REPAIR MECHANISM, AS WELL AS THE IMPORTANT ROLE THAT GENETIC, EPIGENETIC, BIOCHEMICAL AND INFLAMMATORY EVENTS, SEEMINGLY BENEFICIAL TO THE RE-ESTABLISHMENT OF NORMAL RENAL FUNCTION, CAN BE OFFSET BY MEDIATORS OF PROGRESSIVE FIBROSIS AND IRREVERSIBLE STRUCTURAL CHANGES. CHARACTERIZATION OF BASIC PROCESSES THAT MEDIATE THE AKI TO CKD TRANSITION REVEALS PROMISING PHARMACOLOGICAL AND BIOLOGICAL AGENTS THAT HOPEFULLY WILL ONE DAY BE USED IN THE EARLY STAGES OF AKI TO PREVENT ITS DEADLY CONSEQUENCES. 2016 13 2807 28 FETAL PROGRAMMING OF CHRONIC KIDNEY DISEASE: THE ROLE OF MATERNAL SMOKING, MITOCHONDRIAL DYSFUNCTION, AND EPIGENETIC MODFIFICATION. THE ROLE OF AN ADVERSE IN UTERO ENVIRONMENT IN THE PROGRAMMING OF CHRONIC KIDNEY DISEASE IN THE ADULT OFFSPRING IS INCREASINGLY RECOGNIZED. THE CELLULAR AND MOLECULAR MECHANISMS LINKING THE IN UTERO ENVIRONMENT AND FUTURE DISEASE SUSCEPTIBILITY REMAIN UNKNOWN. MATERNAL SMOKING IS A COMMON MODIFIABLE ADVERSE IN UTERO EXPOSURE, POTENTIALLY ASSOCIATED WITH BOTH MITOCHONDRIAL DYSFUNCTION AND EPIGENETIC MODIFICATION IN THE OFFSPRING. WHILE STUDIES ARE EMERGING THAT POINT TOWARD A KEY ROLE OF MITOCHONDRIAL DYSFUNCTION IN ACUTE AND CHRONIC KIDNEY DISEASE, IT MAY HAVE ITS ORIGIN IN EARLY DEVELOPMENT, BECOMING CLINICALLY APPARENT WHEN SECONDARY INSULTS OCCUR. ABERRANT EPIGENETIC PROGRAMMING MAY ADD AN ADDITIONAL LAYER OF COMPLEXITY TO ORCHESTRATE FIBROGENESIS IN THE KIDNEY AND SUSCEPTIBILITY TO CHRONIC KIDNEY DISEASE IN LATER LIFE. IN THIS REVIEW, WE EXPLORE THE EVIDENCE FOR MITOCHONDRIAL DYSFUNCTION AND EPIGENETIC MODIFICATION THROUGH ABERRANT DNA METHYLATION AS KEY MECHANISTIC ASPECTS OF FETAL PROGRAMMING OF CHRONIC KIDNEY DISEASE AND DISCUSS THEIR POTENTIAL USE IN DIAGNOSTICS AND TARGETS FOR THERAPY. 2015 14 97 24 A PRIMER ON THE EPIGENETICS OF KIDNEY FIBROSIS. DESPITE EXTENSIVE KNOWLEDGE OF THE VARIOUS MOLECULAR PATHWAYS THAT CONTRIBUTE TO TUBULOINTERSTITIAL FIBROSIS, IT REMAINS AN UNSOLVED QUESTION WHY THE PROGRESSION RATE OF CHRONIC KIDNEY DISEASE VARIES SUBSTANTIALLY FROM PATIENT TO PATIENT, EVEN AMONG PATIENTS WITH COMMON UNDERLYING NEPHROPATHIES AND COMORBIDITIES. POSSIBLE EXPLANATIONS FOR DIFFERENT SUSCEPTIBILITIES OF INDIVIDUAL PATIENTS TO DEVELOP END-STAGE RENAL FAILURE INCLUDE GENETIC OR EPIGENETIC VARIATIONS, WHICH MODIFY HOW INDIVIDUAL PATIENTS RESPOND TO KIDNEY INJURY. HERE WE REVIEW PRINCIPLES OF EPIGENETIC MECHANISMS IN CONTEXT OF CHRONIC KIDNEY DISEASE AND DISCUSS HOW SUCH INSIGHTS MAY BE UTILIZED FOR FUTURE THERAPEUTIC STRATEGIES AND MAY LEAD TO NOVEL DIAGNOSTIC TOOLS IN THE FUTURE. 2012 15 4743 24 NOVEL INSIGHTS FROM GENETIC AND EPIGENETIC STUDIES IN UNDERSTANDING THE COMPLEX URAEMIC PHENOTYPE. LIKE IN MANY OTHER COMMON COMPLEX DISORDERS, STUDIES OF CHRONIC KIDNEY DISEASE (CKD) CAN NOW MAKE USE OF THE INCREASING KNOWLEDGE OF THE HUMAN GENOME, ITS VARIATIONS AND IMPACT ON DISEASE SUSCEPTIBILITY, INITIATION, PROGRESSION AND COMPLICATIONS. SUCH STUDIES ARE FACILITATED BY NOVEL READILY AVAILABLE HIGH THROUGH-PUT GENOTYPING METHODS AND SOPHISTICATED ANALYTICAL APPROACHES TO SCAN THE GENOME FOR DNA VARIATIONS AND EPIGENETIC MODIFICATIONS. HERE, WE REVIEW SOME OF THE RECENT DISCOVERIES THAT HAVE EMERGED FROM THESE STUDIES AND EXPANDED OUR KNOWLEDGE OF GENETIC RISK LOCI AND EPIGENETIC MARKERS IN CKD PATHOPHYSIOLOGY. OBSTACLES AND PRACTICAL ISSUES IN THIS FIELD ARE DISCUSSED. 2014 16 5647 38 SEX DIFFERENCES IN FETAL KIDNEY REPROGRAMMING: THE CASE IN THE RENIN-ANGIOTENSIN SYSTEM. DURING THE EARLY STAGES OF THE DEVELOPMENT OF THE LIVING MULTIORGAN SYSTEMS, GENOME MODIFICATIONS OTHER THAN SEQUENCE VARIATION OCCUR THAT GUIDE CELL DIFFERENTIATION AND ORGANOGENESIS. THESE MODIFICATIONS ARE KNOWN TO OPERATE AS A FETAL PROGRAMMING CODE DURING THIS PERIOD, AND RECENT RESEARCH INDICATES THAT THERE ARE SOME TISSUE-SPECIFIC CODES IN ORGANOGENESIS WHOSE EFFECTS MAY PERSIST AFTER BIRTH UNTIL ADULTHOOD. CONSEQUENTLY, THE EVENTS THAT DISRUPT THE PRE-ESTABLISHED EPIGENETIC PATTERN COULD INDUCE SHIFTS IN ORGAN PHYSIOLOGY, WITH IMPLICATIONS ON HEALTH FROM BIRTH OR LATER IN ADULT LIFE. CHRONIC KIDNEY DISEASE (CKD) IS ONE OF THE MAIN CAUSES OF MORTALITY WORLDWIDE; ITS ETIOLOGY IS MULTIFACTORIAL, BUT DIABETES, OBESITY, AND HYPERTENSION ARE THE MAIN CAUSES OF CKD IN ADULTS, ALTHOUGH THERE ARE OTHER RISK FACTORS THAT ARE MAINLY ASSOCIATED WITH AN INDIVIDUAL'S LIFESTYLE. RECENT STUDIES SUGGEST THAT FETAL REPROGRAMMING IN THE DEVELOPING KIDNEY COULD BE IMPLICATED IN THE SUSCEPTIBILITY TO KIDNEY DISEASE IN BOTH CHILDHOOD AND ADULTHOOD. SOME EPIGENETIC MODIFICATIONS, SUCH AS GENOME METHYLATION STATUS, DYSREGULATION OF MIRNA, AND HISTONE CODING ALTERATIONS IN GENES RELATED TO THE REGULATION OF THE RENIN-ANGIOTENSIN AXIS, A COMMON DENOMINATOR IN CKD, MAY HAVE ORIGINATED DURING FETAL DEVELOPMENT. THIS REVIEW FOCUSES ON EPIGENETIC CHANGES DURING NEPHROGENESIS AND THEIR REPERCUSSIONS ON KIDNEY HEALTH AND DISEASE. IN ADDITION, THE FOCUS IS ON THE INFLUENCE OF ENVIRONMENTAL FACTORS DURING PREGNANCY, SUCH AS MATERNAL METABOLIC DISEASES AND DIETARY AND METABOLIC CONDITIONS, AS WELL AS SOME SEX DIFFERENCES IN FETAL KIDNEY REPROGRAMMING DURING WHICH DYSREGULATION OF THE RENIN-ANGIOTENSIN SYSTEM IS INVOLVED. 2023 17 6905 22 [THE ROLE OF EPIGENETIC REGULATIONS IN EARLY CHILDHOOD DISEASES]. WITH THE ACCEPTANCE OF "THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE" CONCEPT IN THE 1990S, IT BECAME CLEAR THAT EPIGENETIC INHERITANCE, WHICH DO NOT INVOLVE CHANGES IN THE DNA SEQUENCE HAS IMPORTANT ROLE IN THE PATHOGENESIS OF DISEASES. EPIGENETIC REGULATION SERVES THE ADAPTATION TO THE CHANGING ENVIRONMENT AND MAINTAINS THE REPRODUCTIVE FITNESS EVEN ON THE DRAWBACK OF INCREASED RISK OF DISEASES IN LATER LIFE. THE ROLE OF EPIGENETIC MECHANISMS IN CHRONIC NON-COMMUNICABLE DISEASES HAS BEEN WELL ESTABLISHED. RECENT STUDIES HAVE REVEALED THAT EPIGENETIC CHANGES HAVE ALSO CAUSAL ROLE IN CERTAIN PEDIATRIC DISEASES. THE REVIEW EVALUATES THE RECENT EPIGENETIC FINDINGS IN THE PATHOMECHANISM OF COMMON PEDIATRIC DISEASES. THE WIDE RANGE AND LONG-LASTING DURATION OF EPIGENETIC REGULATIONS GIVE IMPORTANCE TO THE SUBJECT. METHODS ARE ALREADY AVAILABLE TO EVALUATE A PART OF THE EPIGENETIC CHANGES IN THE CLINICAL PRACTICE, PRESENTLY AIMING PRIMARILY THE ESTIMATION OF THE DISEASE RISK OR DEFINITION OF DIAGNOSIS. FURTHERMORE, THERE ARE ALREADY AVAILABLE LIMITED MEANS TO INFLUENCE THE EPIGENETIC REGULATION. 2019 18 859 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 19 6113 32 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 20 5204 26 PRENATAL PROGRAMMING-EFFECTS ON BLOOD PRESSURE AND RENAL FUNCTION. IMPAIRED INTRAUTERINE NEPHROGENESIS-MOST CLEARLY ILLUSTRATED BY LOW NEPHRON NUMBER-IS FREQUENTLY ASSOCIATED WITH LOW BIRTHWEIGHT AND HAS BEEN RECOGNIZED AS A POWERFUL RISK FACTOR FOR RENAL DISEASE; IT INCREASES THE RISKS OF LOW GLOMERULAR FILTRATION RATE, OF MORE RAPID PROGRESSION OF PRIMARY KIDNEY DISEASE, AND OF INCREASED INCIDENCE OF CHRONIC KIDNEY DISEASE OR END-STAGE RENAL DISEASE. ANOTHER IMPORTANT CONSEQUENCE OF IMPAIRED NEPHROGENESIS IS HYPERTENSION, WHICH FURTHER AMPLIFIES THE RISK OF ONSET AND PROGRESSION OF KIDNEY DISEASE. HYPERTENSION IS ASSOCIATED WITH LOW NEPHRON NUMBERS IN WHITE INDIVIDUALS, BUT THE ASSOCIATION IS NOT UNIVERSAL AND IS NOT SEEN IN INDIVIDUALS OF AFRICAN ORIGIN. THE DERANGEMENT OF INTRAUTERINE KIDNEY DEVELOPMENT IS AN EXAMPLE OF A MORE GENERAL PRINCIPLE THAT ILLUSTRATES THE PARADIGM OF PLASTICITY DURING DEVELOPMENT-THAT IS, THAT TRANSCRIPTION OF THE GENETIC CODE IS MODIFIED BY EPIGENETIC FACTORS (AS HAS INCREASINGLY BEEN DOCUMENTED). THIS REVIEW OUTLINES THE CONCEPT OF PRENATAL PROGRAMMING AND, IN PARTICULAR, DESCRIBES ITS ROLE IN KIDNEY DISEASE AND HYPERTENSION. 2011