1 3210 135 HEALTH EFFECTS ASSOCIATED WITH PRE- AND PERINATAL EXPOSURE TO ARSENIC. INORGANIC ARSENIC IS A WELL-ESTABLISHED HUMAN CARCINOGEN, ABLE TO INDUCE GENETIC AND EPIGENETIC ALTERATIONS. MORE THAN 200 MILLION PEOPLE WORLDWIDE ARE EXPOSED TO ARSENIC CONCENTRATIONS IN DRINKING WATER EXCEEDING THE RECOMMENDED WHO THRESHOLD (10MUG/L). ADDITIONALLY, CHRONIC EXPOSURE TO LEVELS BELOW THIS THRESHOLD IS KNOWN TO RESULT IN LONG-TERM HEALTH EFFECTS IN HUMANS. THE ARSENIC-RELATED HEALTH EFFECTS IN HUMANS ARE ASSOCIATED WITH ITS BIOTRANSFORMATION PROCESS, WHEREBY THE RESULTING METABOLITES CAN INDUCE MOLECULAR DAMAGE THAT ACCUMULATES OVER TIME. THE EFFECTS DERIVED FROM THESE ALTERATIONS INCLUDE GENOMIC INSTABILITY ASSOCIATED WITH OXIDATIVE DAMAGE, ALTERATION OF GENE EXPRESSION (INCLUDING CODING AND NON-CODING RNAS), GLOBAL AND LOCALIZED EPIGENETIC REPROGRAMMING, AND HISTONE POSTTRANSLATIONAL MODIFICATIONS. THESE ALTERATIONS DIRECTLY AFFECT MOLECULAR PATHWAYS INVOLVED IN THE ONSET AND PROGRESSION OF MANY CONDITIONS THAT CAN ARISE EVEN DECADES AFTER THE EXPOSURE OCCURS. IMPORTANTLY, ARSENIC METABOLITES GENERATED DURING ITS BIOTRANSFORMATION CAN ALSO PASS THROUGH THE PLACENTAL BARRIER, RESULTING IN FETAL EXPOSURE TO THIS CARCINOGEN AT SIMILAR LEVELS TO THOSE OF THE MOTHER. AS SUCH, MORE IMMEDIATE EFFECTS OF THE ARSENIC-INDUCED MOLECULAR DAMAGE CAN BE OBSERVED AS DETRIMENTAL EFFECTS ON FETAL DEVELOPMENT, PREGNANCY, AND BIRTH OUTCOMES. IN THIS REVIEW, WE FOCUS ON THE GENETIC AND EPIGENETIC DAMAGE ASSOCIATED WITH EXPOSURE TO LOW LEVELS OF ARSENIC, PARTICULARLY THOSE AFFECTING EARLY DEVELOPMENTAL STAGES. WE ALSO PRESENT HOW THESE ALTERATIONS OCCURRING DURING EARLY LIFE CAN IMPACT THE DEVELOPMENT OF CERTAIN DISEASES IN ADULT LIFE. 2021 2 1371 40 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 3 4496 43 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 4 1917 50 ENVIRONMENTAL ARSENIC EXPOSURE: FROM GENETIC SUSCEPTIBILITY TO PATHOGENESIS. MORE THAN 200 MILLION PEOPLE IN 70 COUNTRIES ARE EXPOSED TO ARSENIC THROUGH DRINKING WATER. CHRONIC EXPOSURE TO THIS METALLOID HAS BEEN ASSOCIATED WITH THE ONSET OF MANY DISEASES, INCLUDING CANCER. EPIDEMIOLOGICAL EVIDENCE SUPPORTS ITS CARCINOGENIC POTENTIAL, HOWEVER, DETAILED MOLECULAR MECHANISMS REMAIN TO BE ELUCIDATED. DESPITE THE GLOBAL MAGNITUDE OF THIS PROBLEM, NOT ALL INDIVIDUALS FACE THE SAME RISK. SUSCEPTIBILITY TO THE TOXIC EFFECTS OF ARSENIC IS INFLUENCED BY ALTERATIONS IN GENES INVOLVED IN ARSENIC METABOLISM, AS WELL AS BIOLOGICAL FACTORS, SUCH AS AGE, GENDER AND NUTRITION. MOREOVER, CHRONIC ARSENIC EXPOSURE RESULTS IN SEVERAL GENOTOXIC AND EPIGENETIC ALTERATIONS TIGHTLY ASSOCIATED WITH THE ARSENIC BIOTRANSFORMATION PROCESS, RESULTING IN AN INCREASED CANCER RISK. IN THIS REVIEW, WE: 1) REVIEW THE ROLES OF INTER-INDIVIDUAL DNA-LEVEL VARIATIONS INFLUENCING THE SUSCEPTIBILITY TO ARSENIC-INDUCED CARCINOGENESIS; 2) DISCUSS THE CONTRIBUTION OF ARSENIC BIOTRANSFORMATION TO CANCER INITIATION; 3) PROVIDE INSIGHTS INTO EMERGING RESEARCH AREAS AND THE CHALLENGES IN THE FIELD; AND 4) COMPILE A RESOURCE OF PUBLICLY AVAILABLE ARSENIC-RELATED DNA-LEVEL VARIATIONS, TRANSCRIPTOME AND METHYLATION DATA. UNDERSTANDING THE MOLECULAR MECHANISMS OF ARSENIC EXPOSURE AND ITS SUBSEQUENT HEALTH EFFECTS WILL SUPPORT EFFORTS TO REDUCE THE WORLDWIDE HEALTH BURDEN AND ENCOURAGE THE DEVELOPMENT OF STRATEGIES FOR MANAGING ARSENIC-RELATED DISEASES IN THE ERA OF PERSONALIZED MEDICINE. 2018 5 3582 31 IMPACT OF PRENATAL AND EARLY LIFE ENVIRONMENTAL EXPOSURES ON NORMAL HUMAN DEVELOPMENT. THE GLOBAL BURDEN AND PATTERN OF DISEASE HAS CHANGED IN RECENT DECADES, WITH FEWER EARLY CHILDHOOD DEATHS AND LONGER LIVES COMPLICATED BY CHRONIC DISEASE. DISRUPTION OF NORMAL HUMAN GROWTH AND DEVELOPMENT BY ADVERSE ENVIRONMENTAL EXPOSURES, ESPECIALLY DURING FOETAL DEVELOPMENT AND EARLY POSTNATAL LIFE INCREASE LIFE-LONG RISK OF CHRONIC DISEASE. THE DEVELOPMENTAL TIMING AND METHOD OF ADVERSE EXPOSURE DETERMINES THE LIKELY IMPACT ON HEALTH AND DEVELOPMENT. WHILE MANY ORGAN SYSTEMS ARE STRUCTURALLY AND FUNCTIONALLY MATURE AT BIRTH, THE CNS, RESPIRATORY AND IMMUNE SYSTEMS ARE NOT AND UNDERGO PROLONGED PERIODS OF POSTNATAL GROWTH AND DEVELOPMENT. AS SUCH, THESE ORGAN SYSTEMS ARE VULNERABLE TO ADVERSE EFFECTS OF BOTH PRENATAL AND POSTNATAL ENVIRONMENTAL EXPOSURES. WHILE THE PRECISE MECHANISMS UNDERLYING CHRONIC DISEASE ARE UNKNOWN, EPIGENETIC MECHANISMS AND THE INDUCTION OF OXIDATIVE STRESS ARE LIKELY TO BE INVOLVED. AN UNDERSTANDING OF THESE PROCESSES IS NECESSARY TO DEVELOP MITIGATION STRATEGIES AIMED AT REDUCING CHRONIC DISEASE PREVALENCE. 2021 6 6063 36 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 7 2655 47 EPIMUTAGENESIS: A PROSPECTIVE MECHANISM TO REMEDIATE ARSENIC-INDUCED TOXICITY. ARSENIC TOXICITY IS A GLOBAL ISSUE, ADDRESSED BY THE WORLD HEALTH ORGANIZATION AS ONE OF THE MAJOR NATURAL CALAMITIES FACED BY HUMANS. MORE THAN 137 MILLION INDIVIDUALS IN 70 NATIONS ARE AFFECTED BY ARSENIC MAINLY THROUGH DRINKING WATER AND ALSO THROUGH DIET. CHRONIC ARSENIC EXPOSURE LEADS TO VARIOUS TYPES OF PATHO-PHYSIOLOGICAL END POINTS IN HUMANS INCLUDING CANCERS. ARSENIC, A XENOBIOTIC SUBSTANCE, IS BIOTRANSFORMED IN THE BODY TO ITS METHYLATED SPECIES BY USING THE PHYSIOLOGICAL S-ADENOSYL METHIONINE (SAM). SAM DICTATES METHYLATION STATUS OF THE GENOME AND ARSENIC METABOLISM LEADS TO DEPLETION OF SAM LEADING TO AN EPIGENETIC DISEQUILIBRIUM. SINCE EPIGENETICS IS ONE OF THE MAJOR PHENOMENON AT THE INTERFACE BETWEEN THE ENVIRONMENT AND HUMAN HEALTH IMPACT, ITS DISEQUILIBRIUM BY ARSENIC INFLICTS UPON THE CHROMATIN COMPACTION, GENE EXPRESSION, GENOMIC STABILITY AND A HOST OF BIOMOLECULAR INTERACTIONS, THE INTERACTOME WITHIN THE CELL. SINCE ARSENIC IS NOT MUTAGENIC BUT IS CARCINOGENIC IN NATURE, ARSENIC INDUCED EPIMUTAGENESIS HAS COME TO THE FOREFRONT SINCE IT DETERMINES THE TRANSCRIPTIONAL AND GENOMIC INTEGRITY OF THE CELL. ARSENIC TOXICITY BRINGS FORTH SEVERAL PATHOPHYSIOLOGICAL MANIFESTATIONS LIKE DERMATOLOGICAL NON-CANCEROUS, PRE-CANCEROUS AND CANCEROUS LESIONS, PERIPHERAL NEUROPATHY, DNA DAMAGE, RESPIRATORY DISORDERS AND CANCERS OF SEVERAL INTERNAL ORGANS. RECENTLY, SEVERAL DISEASES OF SIMILAR MANIFESTATIONS HAVE BEEN EXPLAINED WITH THE RELEVANT EPIGENETIC PERSPECTIVES REGARDING THE POSSIBLE MOLECULAR MECHANISM FOR THEIR ONSET. HENCE, IN THE CURRENT REVIEW, WE COMPREHENSIVELY TRY TO INTERCALATE THE INFORMATION ON ARSENIC-INDUCED EPIGENETIC ALTERATIONS OF DNA, HISTONES AND MICRORNA SO AS TO UNDERSTAND WHETHER THE ARSENIC-INDUCED TOXIC MANIFESTATIONS ARE BROUGHT ABOUT BY THE EPIGENETIC CHANGES. WE HIGHLIGHT THE NEED TO UNDERSTAND THE ASPECT OF EPIMUTAGENESIS AND SUBSEQUENT ALTERATIONS IN THE CELLULAR INTERACTOME DUE TO ARSENIC-INDUCED MOLECULAR CHANGES, WHICH MAY BE UTILIZED TO DEVELOP PUTATIVE THERAPEUTIC STRATEGIES TARGETING BOTH OXIDATIVE POTENTIAL AND EPIMUTAGENESIS IN HUMANS. 2015 8 3848 25 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 9 6133 39 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 10 3771 43 INTER- AND TRANSGENERATIONAL EPIGENETIC INHERITANCE: EVIDENCE IN ASTHMA AND COPD? EVIDENCE IS NOW EMERGING THAT EARLY LIFE ENVIRONMENT CAN HAVE LIFELONG EFFECTS ON METABOLIC, CARDIOVASCULAR, AND PULMONARY FUNCTION IN OFFSPRING, A CONCEPT ALSO KNOWN AS FETAL OR DEVELOPMENTAL PROGRAMMING. IN MAMMALS, DEVELOPMENTAL PROGRAMMING IS THOUGHT TO OCCUR MAINLY VIA EPIGENETIC MECHANISMS, WHICH INCLUDE DNA METHYLATION, HISTONE MODIFICATIONS, AND EXPRESSION OF NON-CODING RNAS. THE EFFECTS OF DEVELOPMENTAL PROGRAMMING CAN BE INDUCED BY THE INTRAUTERINE ENVIRONMENT, LEADING TO INTERGENERATIONAL EPIGENETIC EFFECTS FROM ONE GENERATION TO THE NEXT. TRANSGENERATIONAL EPIGENETIC INHERITANCE MAY BE CONSIDERED WHEN DEVELOPMENTAL PROGRAMMING IS TRANSMITTED ACROSS GENERATIONS THAT WERE NOT EXPOSED TO THE INITIAL ENVIRONMENT WHICH TRIGGERED THE CHANGE. SO FAR, INTER- AND TRANSGENERATIONAL PROGRAMMING HAS BEEN MAINLY DESCRIBED FOR CARDIOVASCULAR AND METABOLIC DISEASE RISK. IN THIS REVIEW, WE DISCUSS AVAILABLE EVIDENCE THAT EPIGENETIC INHERITANCE ALSO OCCURS IN RESPIRATORY DISEASES, USING ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AS EXAMPLES. WHILE MULTIPLE EPIDEMIOLOGICAL AS WELL AS ANIMAL STUDIES DEMONSTRATE EFFECTS OF 'TOXIC' INTRAUTERINE EXPOSURE ON VARIOUS ASTHMA-RELATED PHENOTYPES IN THE OFFSPRING, ONLY FEW STUDIES LINK EPIGENETIC MARKS TO THE OBSERVED PHENOTYPES. AS EPIGENETIC MARKS MAY DISTINGUISH INDIVIDUALS MOST AT RISK OF LATER DISEASE AT EARLY AGE, IT WILL ENABLE EARLY INTERVENTION STRATEGIES TO REDUCE SUCH RISKS. TO ACHIEVE THIS GOAL FURTHER, WELL DESIGNED EXPERIMENTAL AND HUMAN STUDIES ARE NEEDED. 2015 11 4125 27 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 12 4767 36 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 13 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 14 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 15 2007 31 EPIGENETIC BASIS FOR FETAL ORIGINS OF AGE-RELATED DISEASE. THE CURRENT CONCEPT OF FETAL ORIGINS OF ADULT DISEASES DESCRIBES IN UTERO PROGRAMMING, OR ADAPTATION TO A SPECTRUM OF ADVERSE ENVIRONMENTAL CONDITIONS THAT ULTIMATELY LEADS TO INCREASED SUSCEPTIBILITY TO AGE-RELATED DISEASES (E.G., TYPE 2 DIABETES AND CARDIOVASCULAR DISEASE) LATER IN LIFE. ALTHOUGH THE PRECISE MECHANISM OF THIS BIOLOGICAL MEMORY REMAINS UNCLEAR, MOUNTING EVIDENCE SUGGESTS AN EPIGENETIC BASIS. THE INCREASED SUSCEPTIBILITY TO CHRONIC DISEASE AND INVOLVEMENT OF MULTIPLE ORGAN SYSTEMS THAT IS OBSERVED IS ANALOGOUS TO THE DECLINE IN RESISTANCE TO DISEASE THAT IS TYPICAL OF NORMAL AGING. ALTHOUGH THE CUMULATIVE ENVIRONMENT OVER THE COURSE OF A LIFETIME CAN INDUCE INCREASING EPIGENETIC DYSREGULATION, WE PROPOSE THAT ADVERSE EVENTS THAT OCCUR DURING EARLY DEVELOPMENT CAN INDUCE SIGNIFICANT ADDITIONAL DYSREGULATION OF THE EPIGENOME. HERE, WE DESCRIBE THE CURRENT EVIDENCE FOR FETAL ORIGINS OF ADULT DISEASE AND THE ASSOCIATED ROLE OF EPIGENETIC DYSREGULATION. IN ADDITION, WE PRESENT A NEW PERSPECTIVE ON THE INDUCTION OF EPIGENETIC ALTERATIONS IN UTERO, WHICH SUBSEQUENTLY LEAD TO AN AGING PHENOTYPE MARKED BY INCREASED SUSCEPTIBILITY TO AGE-RELATED DISEASES. 2010 16 633 40 BIOLOGICAL EFFECTS AND EPIDEMIOLOGICAL CONSEQUENCES OF ARSENIC EXPOSURE, AND REAGENTS THAT CAN AMELIORATE ARSENIC DAMAGE IN VIVO. THROUGH CONTAMINATED DIET, WATER, AND OTHER FORMS OF ENVIRONMENTAL EXPOSURE, ARSENIC AFFECTS HUMAN HEALTH. THERE ARE MANY U.S. AND WORLDWIDE "HOT SPOTS" WHERE THE ARSENIC LEVEL IN PUBLIC WATER EXCEEDS THE MAXIMUM EXPOSURE LIMIT. THE BIOLOGICAL EFFECTS OF CHRONIC ARSENIC EXPOSURE INCLUDE GENERATION OF REACTIVE OXYGEN SPECIES (ROS), LEADING TO OXIDATIVE STRESS AND DNA DAMAGE, EPIGENETIC DNA MODIFICATION, INDUCTION OF GENOMIC INSTABILITY, AND INFLAMMATION AND IMMUNOMODULATION, ALL OF WHICH CAN INITIATE CARCINOGENESIS. HIGH ARSENIC EXPOSURE IS EPIDEMIOLOGICALLY ASSOCIATED WITH SKIN, LUNG, BLADDER, LIVER, KIDNEY AND PANCREATIC CANCER, AND CARDIOVASCULAR, NEURONAL, AND OTHER DISEASES. THIS REVIEW BRIEFLY SUMMARIZES THE BIOLOGICAL EFFECTS OF ARSENIC EXPOSURE AND EPIDEMIOLOGICAL CANCER STUDIES WORLDWIDE, AND PROVIDES AN OVERVIEW FOR EMERGING RODENT-BASED STUDIES OF REAGENTS THAT CAN AMELIORATE THE EFFECTS OF ARSENIC EXPOSURE IN VIVO. THESE REAGENTS MAY BE TRANSLATED TO HUMAN POPULATIONS FOR DISEASE PREVENTION. WE PROPOSE THE IMPORTANCE OF DEVELOPING A BIOMARKER-BASED PRECISION PREVENTION APPROACH FOR THE HEALTH ISSUES ASSOCIATED WITH ARSENIC EXPOSURE THAT AFFECTS MILLIONS OF PEOPLE WORLDWIDE. 2017 17 6812 28 [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 18 1938 36 EPIDEMIOLOGIC EVIDENCE FOR ASSOCIATION BETWEEN ADVERSE ENVIRONMENTAL EXPOSURES IN EARLY LIFE AND EPIGENETIC VARIATION: A POTENTIAL LINK TO DISEASE SUSCEPTIBILITY? A GROWING BODY OF EVIDENCE SUGGESTS THAT THE RISK OF DEVELOPMENT AND PROGRESSION OF A VARIETY OF HUMAN CHRONIC DISEASES DEPENDS ON EPIGENETIC MODIFICATIONS TRIGGERED BY ENVIRONMENTAL CUES DURING EARLY LIFE SENSITIVE STAGES. EXPOSURES TO ENVIRONMENTAL FACTORS SUCH AS ADVERSE NUTRITIONAL, PSYCHOLOGICAL, AND SOCIAL CONDITIONS, AS WELL AS POLLUTANTS AND SUBSTANCE ABUSE IN EARLY LIFE, HAVE BEEN SHOWN TO BE IMPORTANT DETERMINANTS OF EPIGENETIC PROGRAMMING OF CHRONIC PATHOLOGICAL CONDITIONS IN HUMAN POPULATIONS. OVER THE PAST YEARS, IT HAS BECOME INCREASINGLY CLEAR DUE TO THE EPIGENOME-WIDE ASSOCIATION STUDIES (EWASS) THAT EARLY LIFE ADVERSE ENVIRONMENTAL EVENTS MAY TRIGGER WIDESPREAD AND PERSISTENT ALTERATIONS IN TRANSCRIPTIONAL PROFILING. SEVERAL CANDIDATE GENES HAVE BEEN IDENTIFIED UNDERLYING THESE ASSOCIATIONS. IN THIS CONTEXT, DNA METHYLATION IS THE MOST INTENSIVELY STUDIED EPIGENETIC PHENOMENON. IN THIS REVIEW, THE CLINICAL AND EPIDEMIOLOGICAL EVIDENCE FOR THE ROLE OF EPIGENETIC FACTORS IN MEDIATING THE LINK BETWEEN EARLY LIFE EXPERIENCES AND LONG-TERM HEALTH OUTCOMES ARE SUMMARIZED. 2015 19 1801 38 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 2274 31 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