1 1520 134 DNA METHYLATION AT DIFFERENTIALLY METHYLATED REGIONS OF IMPRINTED GENES IS RESISTANT TO DEVELOPMENTAL PROGRAMMING BY MATERNAL NUTRITION. THE NUTRITIONAL ENVIRONMENT IN WHICH THE MAMMALIAN FETUS OR INFANT DEVELOP IS RECOGNIZED AS INFLUENCING THE RISK OF CHRONIC DISEASES, SUCH AS TYPE 2 DIABETES AND HYPERTENSION, IN A PHENOMENON THAT HAS BECOME KNOWN AS DEVELOPMENTAL PROGRAMMING. THE LATE ONSET OF SUCH DISEASES IN RESPONSE TO EARLIER TRANSIENT EXPERIENCES HAS LED TO THE SUGGESTION THAT DEVELOPMENTAL PROGRAMMING MAY HAVE AN EPIGENETIC COMPONENT, BECAUSE EPIGENETIC MARKS SUCH AS DNA METHYLATION OR HISTONE TAIL MODIFICATIONS COULD PROVIDE A PERSISTENT MEMORY OF EARLIER NUTRITIONAL STATES. ONE CLASS OF GENES THAT HAS BEEN CONSIDERED A POTENTIAL TARGET OR MEDIATOR OF PROGRAMMING EVENTS IS IMPRINTED GENES, BECAUSE THESE GENES CRITICALLY DEPEND UPON EPIGENETIC MODIFICATIONS FOR CORRECT EXPRESSION AND BECAUSE MANY IMPRINTED GENES HAVE ROLES IN CONTROLLING FETAL GROWTH AS WELL AS NEONATAL AND ADULT METABOLISM. IN THIS STUDY, WE HAVE USED AN ESTABLISHED MODEL OF DEVELOPMENTAL PROGRAMMING-ISOCALORIC PROTEIN RESTRICTION TO FEMALE MICE DURING GESTATION OR LACTATION-TO EXAMINE WHETHER THERE ARE EFFECTS ON EXPRESSION AND DNA METHYLATION OF IMPRINTED GENES IN THE OFFSPRING. WE FIND THAT ALTHOUGH EXPRESSION OF SOME IMPRINTED GENES IN LIVER OF OFFSPRING IS ROBUSTLY AND SUSTAINABLY CHANGED, METHYLATION OF THE DIFFERENTIALLY METHYLATED REGIONS (DMRS) THAT CONTROL THEIR MONOALLELIC EXPRESSION REMAINS LARGELY UNALTERED. WE CONCLUDE THAT DEREGULATION OF IMPRINTING THROUGH A GENERAL EFFECT ON DMR METHYLATION IS UNLIKELY TO BE A COMMON FACTOR IN DEVELOPMENTAL PROGRAMMING. 2012 2 4496 39 MORE THAN GENES: THE ADVANCED FETAL PROGRAMMING HYPOTHESIS. MANY LINES OF DATA, INITIAL EPIDEMIOLOGIC STUDIES AS WELL AS SUBSEQUENT EXTENSIVE EXPERIMENTAL STUDIES, INDICATE THAT EARLY-LIFE EVENTS PLAY A POWERFUL ROLE IN INFLUENCING LATER SUCEPTIBILITY TO CERTAIN CHRONIC DISEASES. SUCH EVENTS MIGHT BE OVER- OR UNDERNUTRITION, EXPOSURE TO ENVIRONMENTAL TOXINS, BUT ALSO CHANGES IN HORMONES, IN PARTICULAR STRESS HORMONES. TYPICALLY, THOSE EVENTS ARE TRIGGERED BY THE ENVIRONMENTAL CHALLENGES OF THE MOTHER. HOWEVER, RECENT STUDIES HAVE SHOWN THAT PATERNAL ENVIRONMENTAL OR NUTRITIONAL FACTORS AFFECT THE PHENOTYPE OF THE OFFSPRING AS WELL. THE MATERNAL AND PATERNAL ENVIRONMENTAL FACTORS ACT ON THE PHENOTYPE OF THE OFFSPRING VIA EPIGENETIC MODIFICATION OF ITS GENOME. THE ADVANCED FETAL PROGRAMMING HYPOTHESIS PROPOSES AN ADDITIONAL NON-ENVIRONMENTALLY DRIVEN MECHANISM: MATERNAL AND ALSO PATERNAL GENES MAY INFLUENCE THE MATURATING SPERM, THE OOCYTE, AND LATER THE EMBRYO/FETUS, LEADING TO THEIR EPIGENETIC ALTERATION. THUS, THE OBSERVED PHENOTYPE OF THE OFFSPRING MAY BE ALTERED BY MATERNAL/PATERNAL GENES INDEPENDENT OF THE FETAL GENOME. MEANWHILE, SEVERAL INDEPENDENT ASSOCIATION STUDIES IN HUMANS DEALING WITH METABOLIC AND NEUROLOGICAL TRAITS ALSO SUGGEST THAT MATERNAL GENES MIGHT AFFECT THE OFFSPRING PHENOTYPE INDEPENDENT OF THE TRANSMISSION OF THAT PARTICULAR GENE TO THE OFFSPRING. CONSIDERING THE IMPLICATIONS OF THIS HYPOTHESIS, SOME CONCLUSIONS DRAWN FROM TRANSGENIC OR KNOCKOUT ANIMAL MODELS AND BASED ON THE CAUSALITY BETWEEN A GENETIC ALTERATION AND A PHENOTYPE, NEED TO BE CHALLENGED. POSSIBLE IMPLICATIONS FOR THE DEVELOPMENT, DIAGNOSTIC AND THERAPY OF HUMAN GENETIC DISEASES HAVE TO BE INVESTIGATED. 2014 3 6133 44 THE EPIGENETIC ROLE OF VITAMIN C IN NEURODEVELOPMENT. THE MATERNAL DIET DURING PREGNANCY IS A KEY DETERMINANT OF OFFSPRING HEALTH. EARLY STUDIES HAVE LINKED POOR MATERNAL NUTRITION DURING GESTATION WITH A PROPENSITY FOR THE DEVELOPMENT OF CHRONIC CONDITIONS IN OFFSPRING. THESE CONDITIONS INCLUDE CARDIOVASCULAR DISEASE, TYPE 2 DIABETES AND EVEN COMPROMISED MENTAL HEALTH. WHILE MULTIPLE FACTORS MAY CONTRIBUTE TO THESE OUTCOMES, DISTURBED EPIGENETIC PROGRAMMING DURING EARLY DEVELOPMENT IS ONE POTENTIAL BIOLOGICAL MECHANISM. THE EPIGENOME IS PROGRAMMED PRIMARILY IN UTERO, AND DURING THIS TIME, THE DEVELOPING FETUS IS HIGHLY SUSCEPTIBLE TO ENVIRONMENTAL FACTORS SUCH AS NUTRITIONAL INSULTS. DURING NEURODEVELOPMENT, EPIGENETIC PROGRAMMING COORDINATES THE FORMATION OF PRIMITIVE CENTRAL NERVOUS SYSTEM STRUCTURES, NEUROGENESIS, AND NEUROPLASTICITY. DYSREGULATED EPIGENETIC PROGRAMMING HAS BEEN IMPLICATED IN THE AETIOLOGY OF SEVERAL NEURODEVELOPMENTAL DISORDERS SUCH AS TATTON-BROWN-RAHMAN SYNDROME. ACCORDINGLY, THERE IS GREAT INTEREST IN DETERMINING HOW MATERNAL NUTRIENT AVAILABILITY IN PREGNANCY MIGHT AFFECT THE EPIGENETIC STATUS OF OFFSPRING, AND HOW SUCH INFLUENCES MAY PRESENT PHENOTYPICALLY. IN RECENT YEARS, A NUMBER OF EPIGENETIC ENZYMES THAT ARE ACTIVE DURING EMBRYONIC DEVELOPMENT HAVE BEEN FOUND TO REQUIRE VITAMIN C AS A COFACTOR. THESE ENZYMES INCLUDE THE TEN-ELEVEN TRANSLOCATION METHYLCYTOSINE DIOXYGENASES (TETS) AND THE JUMONJI C DOMAIN-CONTAINING HISTONE LYSINE DEMETHYLASES THAT CATALYSE THE OXIDATIVE REMOVAL OF METHYL GROUPS ON CYTOSINES AND HISTONE LYSINE RESIDUES, RESPECTIVELY. THESE ENZYMES ARE INTEGRAL TO EPIGENETIC REGULATION AND HAVE FUNDAMENTAL ROLES IN CELLULAR DIFFERENTIATION, THE MAINTENANCE OF PLURIPOTENCY AND DEVELOPMENT. THE DEPENDENCE OF THESE ENZYMES ON VITAMIN C FOR OPTIMAL CATALYTIC ACTIVITY ILLUSTRATES A POTENTIALLY CRITICAL CONTRIBUTION OF THE NUTRIENT DURING MAMMALIAN DEVELOPMENT. THESE INSIGHTS ALSO HIGHLIGHT A POTENTIAL RISK ASSOCIATED WITH VITAMIN C INSUFFICIENCY DURING PREGNANCY. THE LINK BETWEEN VITAMIN C INSUFFICIENCY AND DEVELOPMENT IS PARTICULARLY APPARENT IN THE CONTEXT OF NEURODEVELOPMENT AND HIGH VITAMIN C CONCENTRATIONS IN THE BRAIN ARE INDICATIVE OF IMPORTANT FUNCTIONAL REQUIREMENTS IN THIS ORGAN. ACCORDINGLY, THIS REVIEW CONSIDERS THE EVIDENCE FOR THE POTENTIAL IMPACT OF MATERNAL VITAMIN C STATUS ON NEURODEVELOPMENTAL EPIGENETICS. 2022 4 3848 37 IS EPIGENETICS AN IMPORTANT LINK BETWEEN EARLY LIFE EVENTS AND ADULT DISEASE? BACKGROUND: EPIGENETIC MECHANISMS PROVIDE ONE POTENTIAL EXPLANATION FOR HOW ENVIRONMENTAL INFLUENCES IN EARLY LIFE CAUSE LONG-TERM CHANGES IN CHRONIC DISEASE SUSCEPTIBILITY. WHEREAS EPIGENETIC DYSREGULATION IS INCREASINGLY IMPLICATED IN VARIOUS RARE DEVELOPMENTAL SYNDROMES AND CANCER, THE ROLE OF EPIGENETICS IN COMPLEX CHRONIC DISEASES, SUCH AS CARDIOVASCULAR DISEASE, TYPE 2 DIABETES AND OBESITY, REMAINS LARGELY UNCHARACTERIZED. EXTENSIVE WORK IN ANIMAL MODELS IS REQUIRED TO DEVELOP SPECIFIC HYPOTHESES THAT CAN BE PRACTICABLY TESTED IN HUMANS. ANIMAL MODELS: WE HAVE DEVELOPED A MOUSE MODEL SHOWING THAT METHYL DONOR SUPPLEMENTATION PREVENTS TRANSGENERATIONAL AMPLIFICATION OF OBESITY, SUGGESTING A ROLE FOR DNA METHYLATION IN THE DEVELOPMENTAL ESTABLISHMENT OF BODY WEIGHT REGULATION. CONCLUSIONS: COUPLING SUCH MODELS WITH RECENTLY DEVELOPED EPIGENOMIC TECHNOLOGIES SHOULD ULTIMATELY ENABLE US TO DETERMINE IF EPIGENETICS IS AN IMPORTANT LINK BETWEEN EARLY LIFE EVENTS AND ADULT DISEASE. 2009 5 2183 39 EPIGENETIC MECHANISMS RESPONSIBLE FOR THE TRANSGENERATIONAL INHERITANCE OF INTRAUTERINE GROWTH RESTRICTION PHENOTYPES. A POORLY FUNCTIONING PLACENTA RESULTS IN IMPAIRED EXCHANGES OF OXYGEN, NUTRITION, WASTES AND HORMONES BETWEEN THE MOTHER AND HER FETUS. THIS CAN LEAD TO RESTRICTION OF FETAL GROWTH. THESE GROWTH RESTRICTED BABIES ARE AT INCREASED RISK OF DEVELOPING CHRONIC DISEASES, SUCH AS TYPE-2 DIABETES, HYPERTENSION, AND KIDNEY DISEASE, LATER IN LIFE. ANIMAL STUDIES HAVE SHOWN THAT GROWTH RESTRICTED PHENOTYPES ARE SEX-DEPENDENT AND CAN BE TRANSMITTED TO SUBSEQUENT GENERATIONS THROUGH BOTH THE PATERNAL AND MATERNAL LINEAGES. ALTERED EPIGENETIC MECHANISMS, SPECIFICALLY CHANGES IN DNA METHYLATION, HISTONE MODIFICATIONS, AND NON-CODING RNAS THAT REGULATE EXPRESSION OF GENES THAT ARE IMPORTANT FOR FETAL DEVELOPMENT HAVE BEEN SHOWN TO BE ASSOCIATED WITH THE TRANSMISSION PATTERN OF GROWTH RESTRICTED PHENOTYPES. THIS REVIEW WILL DISCUSS THE SUBSEQUENT HEALTH OUTCOMES IN THE OFFSPRING AFTER GROWTH RESTRICTION AND THE TRANSMISSION PATTERNS OF THESE DISEASES. EVIDENCE OF ALTERED EPIGENETIC MECHANISMS IN ASSOCIATION WITH FETAL GROWTH RESTRICTION WILL ALSO BE REVIEWED. 2022 6 1371 39 DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE: NEW INSIGHTS. EPIDEMIOLOGICAL AND ANIMAL STUDIES SHOW THAT SMALL CHANGES IN THE DEVELOPMENTAL ENVIRONMENT CAN INDUCE PHENOTYPIC CHANGES AFFECTING AN INDIVIDUAL'S RESPONSES TO THEIR LATER ENVIRONMENT. THESE MAY ALTER THE RISK OF CHRONIC DISEASE SUCH AS METABOLIC SYNDROME OR CARDIOVASCULAR DISEASE. RECENT RESEARCH SHOWS THAT ANIMALS EXPOSED TO SUCH A MISMATCH BETWEEN PRENATAL AND POSTNATAL ENVIRONMENT DEVELOP OBESITY, REDUCED ACTIVITY, LEPTIN AND INSULIN RESISTANCE, ELEVATED BLOOD PRESSURE AND VASCULAR ENDOTHELIAL DYSFUNCTION. EPIGENETIC PROCESSES ARE INVOLVED IN SUCH EFFECTS, TARGETED TO PROMOTER REGIONS OF SPECIFIC GENES IN SPECIFIC TISSUES. SUCH FINE CONTROL OF GENE EXPRESSION SUGGESTS THAT THE MECHANISMS HAVE BEEN RETAINED THROUGH EVOLUTION THROUGH THEIR ADAPTIVE ADVANTAGE, RATHER THAN REPRESENTING EXTREME EFFECTS OF DEVELOPMENTAL DISRUPTION AKIN TO TERATOGENESIS. THERE MAY BE ADAPTIVE ADVANTAGE IN A DEVELOPMENTAL CUE INDUCING A PHENOTYPIC CHANGE IN GENERATIONS BEYOND THE IMMEDIATE PREGNANCY, AND A RANGE OF DATA THAT SUPPORT THIS CONCEPT. IN ANIMALS, EPIGENETIC EFFECTS SUCH AS DNA METHYLATION CAN BE PASSED TO SUCCESSIVE GENERATIONS. ENVIRONMENTAL TOXINS, INCLUDING ENDOCRINE DISRUPTORS, MAY INDUCE GREATER RISK OF CHRONIC DISEASE, EVEN AT LOW EXPOSURE LEVELS, IF THEY AFFECT SUCH NORMAL DEVELOPMENTAL EPIGENETIC PROCESSES. APPROPRIATE INTERVENTIONS MAY HAVE LONG-TERM MULTIGENERATIONAL EFFECTS TO REDUCE THE RISK OF CHRONIC DISEASE. 2008 7 4767 32 NUCLEAR AND MITOCHONDRIAL DNA ALTERATIONS IN NEWBORNS WITH PRENATAL EXPOSURE TO CIGARETTE SMOKE. NEWBORNS EXPOSED TO MATERNAL CIGARETTE SMOKE (CS) IN UTERO HAVE AN INCREASED RISK OF DEVELOPING CHRONIC DISEASES, CANCER, AND ACQUIRING DECREASED COGNITIVE FUNCTION IN ADULTHOOD. ALTHOUGH THE LITERATURE REPORTS MANY DELETERIOUS EFFECTS ASSOCIATED WITH MATERNAL CIGARETTE SMOKING ON THE FETUS, THE MOLECULAR ALTERATIONS AND MECHANISMS OF ACTION ARE NOT YET CLEAR. SMOKING MAY ACT DIRECTLY ON NUCLEAR DNA BY INDUCING MUTATIONS OR EPIGENETIC MODIFICATIONS. RECENT STUDIES ALSO INDICATE THAT SMOKING MAY ACT ON MITOCHONDRIAL DNA BY INDUCING A CHANGE IN THE NUMBER OF COPIES TO MAKE UP FOR THE DAMAGE CAUSED BY SMOKING ON THE RESPIRATORY CHAIN AND LACK OF ENERGY. IN ADDITION, INDIVIDUAL GENETIC SUSCEPTIBILITY PLAYS A SIGNIFICANT ROLE IN DETERMINING THE EFFECTS OF SMOKING DURING DEVELOPMENT. FURTHERMORE, PRIOR EXPOSURE OF PATERNAL AND MATERNAL GAMETES TO CIGARETTE SMOKE MAY AFFECT THE HEALTH OF THE DEVELOPING INDIVIDUAL, NOT ONLY THE IN UTERO EXPOSURE. THIS REVIEW EXAMINES THE GENETIC AND EPIGENETIC ALTERATIONS IN NUCLEAR AND MITOCHONDRIAL DNA ASSOCIATED WITH SMOKE EXPOSURE DURING THE MOST SENSITIVE PERIODS OF DEVELOPMENT (PRIOR TO CONCEPTION, PRENATAL AND EARLY POSTNATAL) AND ASSESSES HOW SUCH CHANGES MAY HAVE CONSEQUENCES FOR BOTH FETAL GROWTH AND DEVELOPMENT. 2015 8 2158 50 EPIGENETIC MECHANISMS FOR NUTRITION DETERMINANTS OF LATER HEALTH OUTCOMES. EPIGENETIC MARKING ON GENES CAN DETERMINE WHETHER OR NOT GENES ARE EXPRESSED. EPIGENETIC REGULATION IS MEDIATED BY THE ADDITION OF METHYL GROUPS TO DNA CYTOSINE BASES, OF METHYL AND ACETYL GROUPS TO PROTEINS (HISTONES) AROUND WHICH DNA IS WRAPPED, AND BY SMALL INTERFERING RNA MOLECULES. SOME COMPONENTS OF EPIGENETIC REGULATION HAVE EVOLVED TO PERMIT CONTROL OF WHETHER MATERNAL OR PATERNAL GENES ARE EXPRESSED. THE EPIGENETIC IMPRINTING OF IGF2 EXPRESSION IS AN EXAMPLE OF MATERNAL AND PATERNAL EPIGENETIC MARKING THAT MODULATES FETAL GROWTH AND FETAL SIZE. HOWEVER, EPIGENETIC REGULATION ALSO PERMITS THE FETUS AND THE INFANT TO ADAPT GENE EXPRESSION TO THE ENVIRONMENT IN WHICH IT IS GROWING; SOMETIMES WHEN THIS ADJUSTMENT GOES AWRY, THE RISK OF CHRONIC DISEASE IS INCREASED. RECENT PROGRESS IN THE UNDERSTANDING OF NUTRITIONAL INFLUENCES ON EPIGENETICS SUGGESTS THAT NUTRIENTS THAT ARE PART OF METHYL-GROUP METABOLISM CAN SIGNIFICANTLY INFLUENCE EPIGENETICS. DURING CRITICAL PERIODS IN DEVELOPMENT, DIETARY METHYL-GROUP INTAKE (CHOLINE, METHIONINE, AND FOLATE) CAN ALTER DNA AND HISTONE METHYLATION, WHICH RESULTS IN LIFELONG CHANGES IN GENE EXPRESSION. IN RODENT MODELS, PREGNANT DAMS THAT WERE FED DIETS HIGH IN METHIONINE, FOLIC ACID, AND CHOLINE PRODUCED OFFSPRING WITH DIFFERENT COAT COLORS OR WITH KINKED TAILS. A NUMBER OF SYNDROMES IN HUMANS CAN BE CAUSED BY DEFECTIVE EPIGENETIC REGULATION, INCLUDING RETT SYNDROME. THERE ARE INTERESTING EXAMPLES OF THE EFFECTS OF NUTRITION IN EARLY LIFE THAT RESULT IN ALTERED HEALTH IN ADULTS, AND SOME OF THESE COULD BE THE RESULT OF ALTERED EPIGENETIC REGULATION OF GENE EXPRESSION. 2009 9 1929 41 ENVIRONMENTAL EXPOSURE, DNA METHYLATION, AND GENE REGULATION: LESSONS FROM DIETHYLSTILBESTEROL-INDUCED CANCERS. DNA METHYLATION IS AN EPIGENETIC MECHANISM THAT REGULATES CHROMOSOMAL STABILITY AND GENE EXPRESSION. ABNORMAL DNA METHYLATION PATTERNS HAVE BEEN OBSERVED IN MANY TYPES OF HUMAN TUMORS, INCLUDING THOSE OF THE BREAST, PROSTATE, COLON, THYROID, STOMACH, UTERUS, AND CERVIX. WE AND OTHERS HAVE SHOWN THAT EXPOSURE TO A WIDE VARIETY OF XENOBIOTICS DURING CRITICAL PERIODS OF MAMMALIAN DEVELOPMENT CAN PERSISTENTLY ALTER THE PATTERN OF DNA METHYLATION, RESULTING IN POTENTIALLY ADVERSE BIOLOGICAL EFFECTS SUCH AS ABERRANT GENE EXPRESSION. THUS, THIS EPIGENETIC MECHANISM MAY UNDERLIE THE OBSERVED INCREASED RISK IN ADULTHOOD OF SEVERAL CHRONIC DISEASES, INCLUDING CANCER, IN RESPONSE TO XENOBIOTIC EXPOSURES EARLY IN LIFE. WE PRESENT HERE THE LESSONS LEARNED FROM STUDIES ON THE EFFECTS OF PERINATAL DIETHYLSTILBESTEROL (DES) EXPOSURE ON THE METHYLATION PATTERN OF THE PROMOTERS OF SEVERAL ESTROGEN-RESPONSIVE GENES ASSOCIATED WITH THE DEVELOPMENT OF REPRODUCTIVE ORGANS. PERINATAL DES EXPOSURE, WHICH INDUCES EPITHELIAL TUMORS OF THE UTERUS IN MICE AND IS ASSOCIATED WITH SEVERAL REPRODUCTIVE TRACT ABNORMALITIES AND INCREASED VAGINAL AND CERVICAL CANCER RISK IN WOMEN, PROVIDES A CLEAR EXAMPLE OF HOW ESTROGENIC XENOBIOTIC EXPOSURE DURING A CRITICAL PERIOD OF DEVELOPMENT CAN ABNORMALLY DEMETHYLATE DNA SEQUENCES DURING ORGAN DEVELOPMENT AND POSSIBLY INCREASE CANCER RISK LATER IN LIFE. IN ADDITION, NUTRITIONAL FACTORS AND STRESS MAY ALSO ALTER DNA METHYLATION DURING EARLY LIFE AND MODULATE THE RISK OF CANCER AND OTHER CHRONIC DISEASES IN ADULTHOOD. WE SUGGEST THAT DNA METHYLATION STATUS MAY BE INFLUENCED BY ENVIRONMENTAL EXPOSURES IN EARLY LIFE, LEADING TO INCREASED RISK OF CANCER IN ADULTHOOD. 2003 10 4125 34 MECHANISMS OF DISEASE: IN UTERO PROGRAMMING IN THE PATHOGENESIS OF HYPERTENSION. NUTRITIONAL AND OTHER ENVIRONMENTAL CUES DURING DEVELOPMENT CAN PERMANENTLY ALTER THE STRUCTURE, HOMEOSTATIC SYSTEMS, AND FUNCTIONS OF THE BODY. THIS PHENOMENON HAS BEEN REFERRED TO AS 'PROGRAMMING'. EPIDEMIOLOGICAL AND ANIMAL STUDIES SHOW THAT PROGRAMMED EFFECTS OPERATE WITHIN THE NORMAL RANGE OF GROWTH AND DEVELOPMENT, AND INFLUENCE THE RISK OF CHRONIC DISEASE IN ADULT LIFE. WE REVIEW THE EVIDENCE THAT THESE EFFECTS INCLUDE REDUCED NEPHRON NUMBER AND COMPENSATORY ADAPTATIONS, WHICH MIGHT LEAD TO HYPERTENSION, AND PERHAPS ACCELERATE THE DECLINE IN RENAL FUNCTION THAT ACCOMPANIES AGING. THESE PROCESSES MIGHT BE EXACERBATED BY PROGRAMMED CHANGES IN VASCULAR STRUCTURE AND FUNCTION, AND ALTERATIONS IN ENDOCRINE AND METABOLIC HOMEOSTASIS. PROGRAMMED EFFECTS MIGHT BE INITIATED AS EARLY AS THE PERICONCEPTUAL PHASE OF DEVELOPMENT, AND COULD INVOLVE EPIGENETIC CHANGES IN GENE EXPRESSION OR ALTERED STEM CELL ALLOCATION. BETTER UNDERSTANDING OF THESE PROCESSES COULD LEAD TO THE DEVELOPMENT OF NOVEL DIAGNOSTIC AND PREVENTIVE MEASURES, AND TO EARLY DETECTION OF AT-RISK INDIVIDUALS. BY MONITORING BLOOD PRESSURE, WEIGHT, AND RENAL FUNCTION IN CHILDREN, IT MIGHT BE POSSIBLE TO REDUCE THE RISK OF CARDIOVASCULAR AND RENAL DISEASE IN LATER LIFE. 2006 11 6812 35 [EPIGENETICS, INTERFACE BETWEEN ENVIRONMENT AND GENES: ROLE IN COMPLEX DISEASES]. EPIGENETICS IS THE STUDY OF HERITABLE CHANGES IN GENE EXPRESSION OR CELLULAR PHENOTYPE CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE. EPIGENETICS IS ONE OF THE MAJOR MECHANISMS EXPLAINING THE "DEVELOPMENTAL ORIGIN OF HEALTH AND DISEASES" (DOHAD). BESIDES GENETIC BACKGROUND INHERITED FROM PARENTS, WHICH CONFERS SUSCEPTIBILITY TO CERTAIN PATHOLOGIES, EPIGENETIC CHANGES CONSTITUTE THE MEMORY OF PREVIOUS EVENTS, EITHER POSITIVE OR NEGATIVE, ALONG THE LIFE CYCLE, INCLUDING AT THE IN UTERO STAGE. THE LATER EXPOSITION TO HOSTILE ENVIRONMENT MAY REVEAL SUCH SUSCEPTIBILITY, WITH THE DEVELOPMENT OF VARIOUS PATHOLOGIES, AMONG THEM NUMEROUS CHRONIC COMPLEX DISEASES. THE DEMONSTRATION OF SUCH A SEQUENCE OF EVENTS HAS BEEN SHOWN FOR METABOLIC DISEASES AS OBESITY, METABOLIC SYNDROME AND TYPE 2 DIABETES, CARDIOVASCULAR DISEASE AND CANCER. IN CONTRAST TO GENETIC PREDISPOSITION, WHICH IS IRREVERSIBLE, EPIGENETIC CHANGES ARE POTENTIALLY REVERSIBLE, THUS GIVING TARGETS NOT ONLY FOR PREVENTION, BUT POSSIBLY ALSO FOR THE TREATMENT OF CERTAIN COMPLEX DISEASES. 2012 12 1974 43 EPIGENETIC ALTERATIONS CAUSED BY NUTRITIONAL STRESS DURING FETAL PROGRAMMING OF THE ENDOCRINE PANCREAS. NUTRITION DURING CRITICAL PERIODS OF DEVELOPMENT IS ONE OF THE PIVOTAL FACTORS IN ESTABLISHING A LIFELONG HEALTHY METABOLISM. DIFFERENT NUTRITIONAL DEFICIENCIES SUCH AS A LOW AVAILABILITY OF PROTEINS IN THE MATERNAL DIET PRODUCE ALTERATIONS IN OFFSPRING THAT INCLUDE CHANGES IN INSULIN AND GLUCOSE METABOLISM, A DECREASE IN THE SIZE AND NUMBER OF CELLS OF PANCREATIC ISLETS OF LANGERHANS, AND PREMATURE AGEING OF THE SECRETORY FUNCTION OF PANCREATIC BETA CELLS. MOREOVER, IT HAS BEEN REPORTED THAT CHRONIC NUTRITIONAL STRESS IS ASSOCIATED WITH EPIGENETIC ALTERATIONS IN MECHANISMS OF GENE REGULATION DURING PANCREATIC DEVELOPMENT AND FUNCTION. THESE ALTERATIONS CAN LEAD TO DYSFUNCTIONAL STATES IN PANCREATIC BETA CELLS, WHICH IN THE LONG RUN ARE RESPONSIBLE FOR THE ONSET OF METABOLIC DISEASES LIKE TYPE 2 DIABETES. THE PRESENT REVIEW SUMMARIZES THE MOST IMPORTANT EVIDENCE IN RELATION TO THE PARTICIPATION OF EPIGENETIC MECHANISMS IN THE REGULATION OF GENE EXPRESSION DURING THE INTRAUTERINE PROGRAMMING OF THE ENDOCRINE PANCREAS IN ANIMAL MODELS. SUCH MECHANISMS INCLUDE DNA METHYLATION AS WELL AS MODIFICATIONS OF HISTONES AND MICRORNAS (MIRNAS). 2015 13 1014 35 CIGARETTE SMOKING AND DNA METHYLATION. DNA METHYLATION IS THE MOST STUDIED EPIGENETIC MODIFICATION, CAPABLE OF CONTROLLING GENE EXPRESSION IN THE CONTEXTS OF NORMAL TRAITS OR DISEASES. IT IS HIGHLY DYNAMIC DURING EARLY EMBRYOGENESIS AND REMAINS RELATIVELY STABLE THROUGHOUT LIFE, AND SUCH PATTERNS ARE INTRICATELY RELATED TO HUMAN DEVELOPMENT. DNA METHYLATION IS A QUANTITATIVE TRAIT DETERMINED BY A COMPLEX INTERPLAY OF GENETIC AND ENVIRONMENTAL FACTORS. GENETIC VARIANTS AT A SPECIFIC LOCUS CAN INFLUENCE BOTH REGIONAL AND DISTANT DNA METHYLATION. THE ENVIRONMENT CAN HAVE VARYING EFFECTS ON DNA METHYLATION DEPENDING ON WHEN THE EXPOSURE OCCURS, SUCH AS DURING PRENATAL LIFE OR DURING ADULTHOOD. IN PARTICULAR, CIGARETTE SMOKING IN THE CONTEXT OF BOTH CURRENT SMOKING AND PRENATAL EXPOSURE IS A STRONG MODIFIER OF DNA METHYLATION. EPIGENOME-WIDE ASSOCIATION STUDIES HAVE UNCOVERED CANDIDATE GENES ASSOCIATED WITH CIGARETTE SMOKING THAT HAVE BIOLOGICALLY RELEVANT FUNCTIONS IN THE ETIOLOGY OF SMOKING-RELATED DISEASES. AS SUCH, DNA METHYLATION IS A POTENTIAL MECHANISTIC LINK BETWEEN CURRENT SMOKING AND CANCER, AS WELL AS PRENATAL CIGARETTE-SMOKE EXPOSURE AND THE DEVELOPMENT OF ADULT CHRONIC DISEASES. 2013 14 6063 30 THE DEVELOPMENTAL ENVIRONMENT, EPIGENETIC BIOMARKERS AND LONG-TERM HEALTH. EVIDENCE FROM BOTH HUMAN AND ANIMAL STUDIES HAS SHOWN THAT THE PRENATAL AND EARLY POSTNATAL ENVIRONMENTS INFLUENCE SUSCEPTIBILITY TO CHRONIC DISEASE IN LATER LIFE AND SUGGESTS THAT EPIGENETIC PROCESSES ARE AN IMPORTANT MECHANISM BY WHICH THE ENVIRONMENT ALTERS LONG-TERM DISEASE RISK. EPIGENETIC PROCESSES, INCLUDING DNA METHYLATION, HISTONE MODIFICATION AND NON-CODING RNAS, PLAY A CENTRAL ROLE IN REGULATING GENE EXPRESSION. THE EPIGENOME IS HIGHLY SENSITIVE TO ENVIRONMENTAL FACTORS IN EARLY LIFE, SUCH AS NUTRITION, STRESS, ENDOCRINE DISRUPTION AND POLLUTION, AND CHANGES IN THE EPIGENOME CAN INDUCE LONG-TERM CHANGES IN GENE EXPRESSION AND PHENOTYPE. IN THIS REVIEW WE FOCUS ON HOW THE EARLY LIFE NUTRITIONAL ENVIRONMENT CAN ALTER THE EPIGENOME LEADING TO AN ALTERED SUSCEPTIBILITY TO DISEASE IN LATER LIFE. 2015 15 2038 29 EPIGENETIC CHANGES PREDISPOSING TO TYPE 2 DIABETES IN INTRAUTERINE GROWTH RETARDATION. EPIDEMIOLOGIC STUDIES HAVE DEMONSTRATED AN ASSOCIATION BETWEEN INTRAUTERINE GROWTH RETARDATION AND A GREATER RISK OF CHRONIC DISEASE, INCLUDING CORONARY HEART DISEASE, HYPERTENSION, STROKE, AND TYPE 2 DIABETES IN ADULTHOOD. AN ADVERSE INTRAUTERINE ENVIRONMENT MAY AFFECT BOTH GROWTH AND DEVELOPMENT OF THE ORGANISM, PERMANENTLY PROGRAMMING ENDOCRINE AND METABOLIC FUNCTIONS. ONE OF THE MECHANISMS OF PROGRAMMING IS THE EPIGENETIC MODIFICATION OF GENE PROMOTERS INVOLVED IN THE CONTROL OF KEY METABOLIC PATHWAYS. THE AIM OF THIS REVIEW IS TO PROVIDE AN OVERVIEW OF THE EXPERIMENTAL EVIDENCE SHOWING THE EFFECTS OF EARLY EXPOSURE TO SUBOPTIMAL ENVIRONMENT ON EPIGENOME. THE KNOWLEDGE OF THE EPIGENETIC MARKERS OF PROGRAMMING MAY ALLOW THE IDENTIFICATION OF SUSCEPTIBLE INDIVIDUALS AND THE DESIGN OF TARGETED PREVENTION STRATEGIES. 2010 16 6844 33 [METABOLIC PROGRAMMING: THEORETICAL CONCEPTS AND EXPERIMENTAL EVIDENCE]. IT IS KNOWN THAT THE POOR NUTRITION DURING A FETAL DEVELOPMENT MAY CONTRIBUTE TO AN INCREASED RISK OF CHRONIC DISEASES IN ADULTHOOD. IN A MODERN LITERATURE, THIS PHENOMENON IS CALLED <>. IT IS ASSUMED THAT THE QUALITATIVE OR QUANTITATIVE DEFICIENCY OF CERTAIN NUTRITIONAL COMPONENTS DURING AN EARLY DEVELOPMENT MAY LEAD TO THE ADAPTATIONS THAT CONTRIBUTE TO IMPROVED SURVIVAL DURING THE PRENATAL AND EARLY POSTNATAL PERIODS OF AN ONTOGENESIS. HOWEVER, THE CONSEQUENCE OF SUCH ADAPTIVE CHANGES MAY ALSO BE THE DEVELOPMENT OF VARIOUS PATHOLOGICAL PROCESSES AT THE LATER STAGES OF LIFE. RECENT STUDIES HAVE SHOWN THAT ONE OF THE MAJOR MECHANISMS INVOLVED IN THESE ADAPTATIONS IS THE EPIGENETIC REGULATION OF A GENE ACTIVITY. IN THIS REVIEW, THE EXPERIMENTAL EVIDENCE IS PROVIDED THAT PROCESSES ARISING FROM A QUANTITATIVELY OR QUALITATIVELY RESTRICTED DIET DURING THE EARLY STAGES OF DEVELOPMENT PLAY AN IMPORTANT ROLE IN THE FURTHER LIFE AND CAN GREATLY INFLUENCE RISK OF VARIOUS AGE-RELATED DISEASES AND LIFE SPAN. 2013 17 2274 32 EPIGENETIC REGULATION AND FETAL PROGRAMMING. FETAL PROGRAMMING ENCOMPASSES THE ROLE OF DEVELOPMENTAL PLASTICITY IN RESPONSE TO ENVIRONMENTAL AND NUTRITIONAL SIGNALS DURING EARLY LIFE AND ITS POTENTIAL ADVERSE CONSEQUENCES (RISK OF CARDIOVASCULAR, METABOLIC AND BEHAVIOURAL DISEASES) IN LATER LIFE. THE FIRST STUDIES IN THIS FIELD HIGHLIGHTED AN ASSOCIATION BETWEEN POOR FETAL GROWTH AND CHRONIC ADULT DISEASES. HOWEVER, ENVIRONMENTAL SIGNALS DURING EARLY LIFE MAY LEAD TO ADVERSE LONG-TERM EFFECTS INDEPENDENTLY OF OBVIOUS EFFECTS ON FETAL GROWTH. ADVERSE LONG-TERM EFFECTS REFLECT A MISMATCH BETWEEN EARLY (FETAL AND NEONATAL) ENVIRONMENTAL CONDITIONS AND THE CONDITIONS THAT THE INDIVIDUAL WILL CONFRONT LATER IN LIFE. THE MECHANISMS UNDERLYING THIS RISK REMAIN UNCLEAR. HOWEVER, EXPERIMENTAL DATA IN RODENTS AND RECENT OBSERVATIONS IN HUMANS SUGGEST THAT EPIGENETIC CHANGES IN REGULATORY GENES AND GROWTH-RELATED GENES PLAY A SIGNIFICANT ROLE IN FETAL PROGRAMMING. IMPROVEMENTS IN OUR UNDERSTANDING OF THE BIOCHEMICAL AND MOLECULAR MECHANISMS AT PLAY IN FETAL PROGRAMMING WOULD MAKE IT POSSIBLE TO IDENTIFY BIOMARKERS FOR DETECTING INFANTS AT HIGH RISK OF ADULT-ONSET DISEASES. SUCH IMPROVEMENTS SHOULD ALSO LEAD TO THE DEVELOPMENT OF PREVENTIVE AND THERAPEUTIC STRATEGIES. 2008 18 2541 37 EPIGENETICS IN KIDNEY DEVELOPMENT AND RENAL DISEASE. THE STUDY OF EPIGENETICS IS INTIMATELY LINKED AND INSEPARABLE FROM DEVELOPMENTAL BIOLOGY. MANY OF THE GENES THAT IMPRINT EPIGENETIC INFORMATION ON CHROMATIN FUNCTION DURING THE SPECIFICATION OF CELL LINEAGES IN THE DEVELOPING EMBRYO. THESE INCLUDE THE HISTONE METHYLTRANSFERASES AND THEIR COFACTORS OF THE POLYCOMB AND TRITHORAX GENE FAMILIES. HOW HISTONE METHYLATION IS ESTABLISHED AND WHAT REGULATES THE TISSUE AND LOCUS SPECIFICITY OF HISTONE METHYLATION IS AN EMERGING AREA OF RESEARCH. THE EMBRYONIC KIDNEY IS USED AS A MODEL TO UNDERSTAND HOW DNA-BINDING PROTEINS CAN SPECIFY CELL LINEAGES AND HOW SUCH PROTEINS INTERACT DIRECTLY WITH THE HISTONE METHYLATION MACHINERY TO GENERATE A UNIQUE EPIGENOME FOR PARTICULAR TISSUES AND CELL TYPES. IN ADULT TISSUES, HISTONE METHYLATION MARKS MUST BE MAINTAINED FOR NORMAL GENE EXPRESSION PATTERNS. IN CHRONIC AND ACUTE RENAL DISEASE, EPIGENETIC MARKS ARE BEING CHARACTERIZED AND CORRELATED WITH THE ESTABLISHMENT OF METABOLIC MEMORY, IN PART TO EXPLAIN THE PERSISTENCE OF PATHOLOGIES EVEN WHEN OPTIMAL TREATMENT MODALITIES ARE USED. THUS, THE STATE OF THE EPIGENOME IN ADULT CELLS MUST BE CONSIDERED WHEN ATTEMPTING TO ALLEVIATE OR ALTER GENE EXPRESSION PATTERNS IN DISEASE. 2015 19 1801 45 EFFECT OF MATERNAL DIET ON THE EPIGENOME: IMPLICATIONS FOR HUMAN METABOLIC DISEASE. THE RAPID INCREASE IN THE INCIDENCE OF CHRONIC NON-COMMUNICABLE DISEASES OVER THE PAST TWO DECADES CANNOT BE EXPLAINED SOLELY BY GENETIC AND ADULT LIFESTYLE FACTORS. THERE IS NOW CONSIDERABLE EVIDENCE THAT THE FETAL AND EARLY POSTNATAL ENVIRONMENT ALSO STRONGLY INFLUENCES THE RISK OF DEVELOPING SUCH DISEASES IN LATER LIFE. HUMAN STUDIES HAVE SHOWN THAT LOW BIRTH WEIGHT IS ASSOCIATED WITH AN INCREASED RISK OF CVD, TYPE II DIABETES, OBESITY AND HYPERTENSION, ALTHOUGH RECENT STUDIES HAVE SHOWN THAT OVER-NUTRITION IN EARLY LIFE CAN ALSO INCREASE SUSCEPTIBILITY TO FUTURE METABOLIC DISEASE. THESE FINDINGS HAVE BEEN REPLICATED IN A VARIETY OF ANIMAL MODELS, WHICH HAVE SHOWN THAT BOTH MATERNAL UNDER- AND OVER-NUTRITION CAN INDUCE PERSISTENT CHANGES IN GENE EXPRESSION AND METABOLISM WITHIN THE OFFSPRING. THE MECHANISM BY WHICH THE MATERNAL NUTRITIONAL ENVIRONMENT INDUCES SUCH CHANGES IS BEGINNING TO BE UNDERSTOOD AND INVOLVES THE ALTERED EPIGENETIC REGULATION OF SPECIFIC GENES. THE DEMONSTRATION OF A ROLE FOR ALTERED EPIGENETIC REGULATION OF GENES IN THE DEVELOPMENTAL INDUCTION OF CHRONIC DISEASES RAISES THE POSSIBILITY THAT NUTRITIONAL OR PHARMACEUTICAL INTERVENTIONS MAY BE USED TO MODIFY LONG-TERM CARDIO-METABOLIC DISEASE RISK AND COMBAT THIS RAPID RISE IN CHRONIC NON-COMMUNICABLE DISEASES. 2011 20 2346 39 EPIGENETIC REGULATION OF METABOLISM AND INFLAMMATION BY CALORIE RESTRICTION. CHRONIC CALORIC RESTRICTION (CR) WITHOUT MALNUTRITION IS KNOWN TO AFFECT DIFFERENT CELLULAR PROCESSES SUCH AS STEM CELL FUNCTION, CELL SENESCENCE, INFLAMMATION, AND METABOLISM. DESPITE THE DIFFERENCES IN THE IMPLEMENTATION OF CR, THE REDUCTION OF CALORIES PRODUCES A WIDESPREAD BENEFICIAL EFFECT IN NONCOMMUNICABLE CHRONIC DISEASES, WHICH CAN BE EXPLAINED BY IMPROVEMENTS IN IMMUNO-METABOLIC ADAPTATION. CELLULAR ADAPTATION THAT OCCURS IN RESPONSE TO DIETARY PATTERNS CAN BE EXPLAINED BY ALTERATIONS IN EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS, AND MICRORNA. IN THIS REVIEW, WE DEFINE THESE MODIFICATIONS AND SYSTEMATICALLY SUMMARIZE THE CURRENT EVIDENCE RELATED TO CR AND THE EPIGENOME. WE THEN EXPLAIN THE SIGNIFICANCE OF GENOME-WIDE EPIGENETIC MODIFICATIONS IN THE CONTEXT OF DISEASE DEVELOPMENT. ALTHOUGH SUBSTANTIAL EVIDENCE EXISTS FOR THE WIDESPREAD EFFECT OF CR ON LONGEVITY, THERE IS NO CONSENSUS REGARDING THE EPIGENETIC REGULATIONS OF THE UNDERLYING CELLULAR MECHANISMS THAT LEAD TO IMPROVED HEALTH. WE PROVIDE COMPELLING EVIDENCE THAT CR PRODUCES LONG-LASTING EPIGENETIC EFFECTS THAT MEDIATE EXPRESSION OF GENES RELATED TO IMMUNO-METABOLIC PROCESSES. EPIGENETIC REPROGRAMMING OF THE UNDERLYING CHRONIC LOW-GRADE INFLAMMATION BY CR CAN LEAD TO IMMUNO-METABOLIC ADAPTATIONS THAT ENHANCE QUALITY OF LIFE, EXTEND LIFESPAN, AND DELAY CHRONIC DISEASE ONSET. 2019