1 3632 132 INCORPORATING TRANSGENERATIONAL EPIGENETIC INHERITANCE INTO ECOLOGICAL RISK ASSESSMENT FRAMEWORKS. CHRONIC EXPOSURE TO ENVIRONMENTAL CONTAMINANTS CAN INDUCE HERITABLE "TRANSGENERATIONAL" MODIFICATIONS TO ORGANISMS, POTENTIALLY AFFECTING FUTURE ECOSYSTEM HEALTH AND FUNCTIONALITY. INCORPORATING TRANSGENERATIONAL EPIGENETIC HERITABILITY INTO RISK ASSESSMENT PROCEDURES HAS BEEN PREVIOUSLY SUGGESTED. HOWEVER, A CRITICAL REVIEW OF EXISTING LITERATURE YIELDED NUMEROUS STUDIES CLAIMING TRANSGENERATIONAL IMPACTS, WITH LITTLE COMPELLING EVIDENCE. THEREFORE, CONTAMINANT-INDUCED EPIGENETIC INHERITANCE MAY BE LESS COMMON THAN IS REPORTED IN THE LITERATURE. WE IDENTIFIED A NEED FOR MULTIGENERATION EPIGENETIC STUDIES THAT EXTEND BEYOND WHAT COULD BE DEEMED "DIRECT EXPOSURE" TO F1 AND F2 GAMETES AND ALSO INCLUDE SUBSEQUENT MULTIPLE NONEXPOSED GENERATIONS TO ADEQUATELY EVALUATE TRANSGENERATIONAL RECOVERY TIMES. ALSO, INCREASED EXPERIMENTAL REPLICATION IS REQUIRED TO ACCOUNT FOR THE HIGHLY VARIABLE NATURE OF EPIGENETIC RESPONSES AND APPARENT IRREPRODUCIBILITY OF CURRENT STUDIES. FURTHER, EPIGENETIC END POINTS NEED TO BE CORRELATED WITH OBSERVABLE DETRIMENTAL ORGANISM CHANGES BEFORE A NEED FOR RISK MANAGEMENT CAN BE PROPERLY DETERMINED. WE SUGGEST THAT EPIGENETIC-BASED CONTAMINANT STUDIES INCLUDE CONCENTRATIONS LOWER THAN CURRENT "EC(10-20)" OR "LOWEST OBSERVABLE EFFECT CONCENTRATIONS" FOR THE ORGANISM'S MOST SENSITIVE PHENOTYPIC END POINT, AS HIGHER CONCENTRATIONS ARE LIKELY ALREADY REGULATED. FINALLY, WE PROPOSE A REGULATORY FRAMEWORK AND OPTIMAL EXPERIMENTAL DESIGN THAT ENABLES TRANSGENERATIONAL EPIGENETIC EFFECTS TO BE ASSESSED AND INCORPORATED INTO CONVENTIONAL ECOTOXICOLOGICAL TESTING. 2017 2 2137 41 EPIGENETIC INHERITANCE AND EVOLUTION: A PATERNAL PERSPECTIVE ON DIETARY INFLUENCES. THE EARLIEST INDICATIONS FOR PATERNALLY INDUCED TRANSGENERATIONAL EFFECTS FROM THE ENVIRONMENT TO FUTURE GENERATIONS WERE BASED ON A SMALL NUMBER OF LONG-TERM EPIDEMIOLOGICAL STUDIES AND SOME EMPIRICAL OBSERVATIONS. ONLY RECENTLY HAVE EXPERIMENTAL ANIMAL MODELS AND A FEW ANALYSES ON HUMAN DATA EXPLORED THE TRANSGENERATIONAL NATURE OF PHENOTYPIC CHANGES OBSERVED IN OFFSPRING. CHANGES INCLUDE MULTIPLE METABOLIC DISORDERS, CANCER AND OTHER CHRONIC DISEASES. THESE PHENOTYPES CANNOT ALWAYS BE EXPLAINED BY MENDELIAN INHERITANCE, DNA MUTATIONS OR GENETIC DAMAGE. HENCE, A NEW COMPELLING THEORY ON EPIGENETIC INHERITANCE IS GAINING INTEREST, PROVIDING NEW CONCEPTS THAT EXTEND DARWIN'S EVOLUTIONARY THEORY. EPIGENETIC ALTERATIONS OR "EPIMUTATIONS" ARE BEING CONSIDERED TO EXPLAIN TRANSGENERATIONAL INHERITANCE OF PARENTALLY ACQUIRED TRAITS. THE RESPONSIBLE MECHANISMS FOR THESE EPIMUTATIONS INCLUDE DNA METHYLATION, HISTONE MODIFICATION, AND RNA-MEDIATED EFFECTS. THIS REVIEW EXPLORES THE LITERATURE ON A NUMBER OF TIME-DEPENDENT ENVIRONMENTALLY INDUCED EPIGENETIC ALTERATIONS, SPECIFICALLY THOSE FROM DIETARY EXPOSURES. WE SUGGEST A ROLE FOR THE MALE GERM LINE AS ONE OF NATURE'S TOOLS TO CAPTURE MESSAGES FROM OUR CONTINUOUSLY CHANGING ENVIRONMENT AND TO TRANSFER THIS INFORMATION TO SUBSEQUENT GENERATIONS. FURTHER, WE OPEN THE DISCUSSION THAT THE PATERNALLY INHERITED EPIGENETIC INFORMATION MAY CONTRIBUTE TO EVOLUTIONARY ADAPTATION. 2015 3 4496 31 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 6295 38 THE PROMISES AND CHALLENGES OF TOXICO-EPIGENOMICS: ENVIRONMENTAL CHEMICALS AND THEIR IMPACTS ON THE EPIGENOME. BACKGROUND: IT HAS BEEN ESTIMATED THAT A SUBSTANTIAL PORTION OF CHRONIC AND NONCOMMUNICABLE DISEASES CAN BE CAUSED OR EXACERBATED BY EXPOSURE TO ENVIRONMENTAL CHEMICALS. MULTIPLE LINES OF EVIDENCE INDICATE THAT EARLY LIFE EXPOSURE TO ENVIRONMENTAL CHEMICALS AT RELATIVELY LOW CONCENTRATIONS COULD HAVE LASTING EFFECTS ON INDIVIDUAL AND POPULATION HEALTH. ALTHOUGH THE POTENTIAL ADVERSE EFFECTS OF ENVIRONMENTAL CHEMICALS ARE KNOWN TO THE SCIENTIFIC COMMUNITY, REGULATORY AGENCIES, AND THE PUBLIC, LITTLE IS KNOWN ABOUT THE MECHANISTIC BASIS BY WHICH THESE CHEMICALS CAN INDUCE LONG-TERM OR TRANSGENERATIONAL EFFECTS. TO ADDRESS THIS QUESTION, EPIGENETIC MECHANISMS HAVE EMERGED AS THE POTENTIAL LINK BETWEEN GENETIC AND ENVIRONMENTAL FACTORS OF HEALTH AND DISEASE. OBJECTIVES: WE PRESENT AN OVERVIEW OF EPIGENETIC REGULATION AND A SUMMARY OF REPORTED EVIDENCE OF ENVIRONMENTAL TOXICANTS AS EPIGENETIC DISRUPTORS. WE ALSO DISCUSS THE ADVANTAGES AND CHALLENGES OF USING EPIGENETIC BIOMARKERS AS AN INDICATOR OF TOXICANT EXPOSURE, USING MEASURES THAT CAN BE TAKEN TO IMPROVE RISK ASSESSMENT, AND OUR PERSPECTIVES ON THE FUTURE ROLE OF EPIGENETICS IN TOXICOLOGY. DISCUSSION: UNTIL RECENTLY, EFFORTS TO APPLY EPIGENOMIC DATA IN TOXICOLOGY AND RISK ASSESSMENT WERE RESTRICTED BY AN INCOMPLETE UNDERSTANDING OF EPIGENOMIC VARIABILITY ACROSS TISSUE TYPES AND POPULATIONS. THIS IS POISED TO CHANGE WITH THE DEVELOPMENT OF NEW TOOLS AND CONCERTED EFFORTS BY RESEARCHERS ACROSS DISCIPLINES THAT HAVE LED TO A BETTER UNDERSTANDING OF EPIGENETIC MECHANISMS AND COMPREHENSIVE MAPS OF EPIGENOMIC VARIATION. WITH THE FOUNDATIONS NOW IN PLACE, WE FORESEE THAT UNPRECEDENTED ADVANCEMENTS WILL TAKE PLACE IN THE FIELD IN THE COMING YEARS. HTTPS://DOI.ORG/10.1289/EHP6104. 2020 5 3210 30 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 6 6554 30 TRANSGENERATIONAL EFFECTS OF EARLY ENVIRONMENTAL INSULTS ON AGING AND DISEASE INCIDENCE. ADVERSE EARLY LIFE EXPERIENCES ARE MAJOR INFLUENCES ON DEVELOPMENTAL TRAJECTORIES WITH POTENTIALLY LIFE-LONG CONSEQUENCES. PRENATAL OR EARLY POSTNATAL EXPOSURE TO STRESS, UNDERNUTRITION OR ENVIRONMENTAL TOXICANTS MAY REPROGRAM BRAIN DEVELOPMENT AND INCREASE RISK OF BEHAVIOURAL AND NEUROLOGICAL DISORDERS LATER IN LIFE. NOT ONLY EXPERIENCE WITHIN A SINGLE LIFETIME, BUT ALSO ANCESTRAL EXPERIENCE AFFECTS HEALTH TRAJECTORIES AND CHANCES OF SUCCESSFUL AGING. THE CENTRAL MECHANISM IN TRANSGENERATIONAL PROGRAMMING OF A DISEASE MAY BE THE FORMATION OF EPIGENETIC MEMORY. THIS REVIEW EXPLORES TRANSGENERATIONAL EFFECTS OF EARLY ADVERSE EXPERIENCE ON HEALTH AND DISEASE INCIDENCE IN OLDER AGE. FIRST, WE ADDRESS MECHANISMS OF DEVELOPMENTAL AND TRANSGENERATIONAL PROGRAMMING OF DISEASE AND INHERITANCE. SECOND, WE DISCUSS EXPERIMENTAL AND CLINICAL FINDINGS LINKING EARLY ENVIRONMENTAL DETERMINANTS TO ADVERSE AGING TRAJECTORIES IN ASSOCIATION WITH POSSIBLE PARENTAL CONTRIBUTIONS AND SEX-SPECIFIC EFFECTS. THIRD, WE OUTLINE THE MAIN MECHANISMS OF AGE-RELATED FUNCTIONAL DECLINE AND SUGGEST POTENTIAL INTERVENTIONS TO REVERSE NEGATIVE EFFECTS OF TRANSGENERATIONAL PROGRAMMING. THUS, STRATEGIES THAT SUPPORT HEALTHY DEVELOPMENT AND SUCCESSFUL AGING SHOULD TAKE INTO ACCOUNT THE POTENTIAL INFLUENCES OF TRANSGENERATIONAL INHERITANCE. 2020 7 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 8 1932 28 ENVIRONMENTAL EXPOSURES: AN UNDERRECOGNIZED CONTRIBUTION TO NONCOMMUNICABLE DISEASES. PREVIOUS ATTEMPTS TO DETERMINE THE DEGREE TO WHICH EXPOSURE TO ENVIRONMENTAL FACTORS CONTRIBUTE TO NONCOMMUNICABLE DISEASES (NCDS) HAVE BEEN VERY CONSERVATIVE AND HAVE SIGNIFICANTLY UNDERESTIMATED THE ACTUAL CONTRIBUTION OF THE ENVIRONMENT FOR AT LEAST TWO REASONS. FIRSTLY, MOST PREVIOUS REPORTS HAVE EXCLUDED THE CONTRIBUTION OF LIFESTYLE BEHAVIORAL RISK FACTORS, BUT THESE USUALLY INVOLVE SIGNIFICANT EXPOSURE TO ENVIRONMENTAL CHEMICALS THAT INCREASE RISK OF DISEASE. SECONDLY, EARLY LIFE EXPOSURE TO CHEMICAL CONTAMINANTS IS NOW CLEARLY ASSOCIATED WITH AN ELEVATED RISK OF SEVERAL DISEASES LATER IN LIFE, BUT THESE CONNECTIONS ARE OFTEN DIFFICULT TO DISCERN. THIS IS ESPECIALLY TRUE FOR ASTHMA AND NEURODEVELOPMENTAL CONDITIONS, BUT THERE IS ALSO A MAJOR CONTRIBUTION TO THE DEVELOPMENT OF OBESITY AND CHRONIC DISEASES. MOST CANCERS ARE CAUSED BY ENVIRONMENTAL EXPOSURES IN GENETICALLY SUSCEPTIBLE INDIVIDUALS. IN ADDITION, NEW INFORMATION SHOWS SIGNIFICANT ASSOCIATIONS BETWEEN CARDIOVASCULAR DISEASES AND DIABETES AND EXPOSURE TO ENVIRONMENTAL CHEMICALS PRESENT IN AIR, FOOD, AND WATER. THESE RELATIONSHIPS LIKELY REFLECT THE COMBINATION OF EPIGENETIC EFFECTS AND GENE INDUCTION. ENVIRONMENTAL FACTORS CONTRIBUTE SIGNIFICANTLY MORE TO NCDS THAN PREVIOUS REPORTS HAVE SUGGESTED. PREVENTION NEEDS TO SHIFT FOCUS FROM INDIVIDUAL RESPONSIBILITY TO SOCIETAL RESPONSIBILITY AND AN UNDERSTANDING THAT EFFECTIVE PREVENTION OF NCDS ULTIMATELY RELIES ON IMPROVED ENVIRONMENTAL MANAGEMENT TO REDUCE EXPOSURE TO MODIFIABLE RISKS. 2013 9 1371 32 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 10 3771 40 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 11 634 34 BIOLOGICAL EMBEDDING OF EARLY-LIFE ADVERSITY AND A SCOPING REVIEW OF THE EVIDENCE FOR INTERGENERATIONAL EPIGENETIC TRANSMISSION OF STRESS AND TRAUMA IN HUMANS. SEVERE OR CHRONIC STRESS AND TRAUMA CAN HAVE A DETRIMENTAL IMPACT ON HEALTH. EVIDENCE SUGGESTS THAT EARLY-LIFE ADVERSITY CAN BECOME BIOLOGICALLY EMBEDDED AND HAS THE POTENTIAL TO INFLUENCE HEALTH OUTCOMES DECADES LATER. EPIGENETICS IS ONE MECHANISM THAT HAS BEEN IMPLICATED IN THESE LONG-LASTING EFFECTS. OBSERVATIONAL STUDIES IN HUMANS INDICATE THAT THE EFFECTS OF STRESS COULD EVEN PERSIST ACROSS GENERATIONS, ALTHOUGH WHETHER OR NOT EPIGENETIC MECHANISMS ARE INVOLVED REMAINS UNDER DEBATE. HERE, WE PROVIDE AN OVERVIEW OF STUDIES IN ANIMALS AND HUMANS THAT DEMONSTRATE THE EFFECTS OF EARLY-LIFE STRESS ON DNA METHYLATION, ONE OF THE MOST WIDELY STUDIED EPIGENETIC MECHANISMS, AND SUMMARIZE FINDINGS FROM ANIMAL MODELS DEMONSTRATING THE INVOLVEMENT OF EPIGENETICS IN THE TRANSMISSION OF STRESS ACROSS GENERATIONS. WE THEN DESCRIBE THE RESULTS OF A SCOPING REVIEW TO DETERMINE THE EXTENT TO WHICH THE TERMS INTERGENERATIONAL OR TRANSGENERATIONAL HAVE BEEN USED IN HUMAN STUDIES INVESTIGATING THE TRANSMISSION OF TRAUMA AND STRESS VIA EPIGENETIC MECHANISMS. WE END WITH A DISCUSSION OF KEY AREAS FOR FUTURE RESEARCH TO ADVANCE UNDERSTANDING OF THE ROLE OF EPIGENETICS IN THE LEGACY EFFECTS OF STRESS AND TRAUMA. 2023 12 2651 41 EPIGENOMICS AND TRANSCRIPTOMICS IN THE PREDICTION AND DIAGNOSIS OF CHILDHOOD ASTHMA: ARE WE THERE YET? ASTHMA IS THE MOST COMMON NON-COMMUNICABLE CHRONIC DISEASE OF CHILDHOOD. DESPITE ITS HIGH PREVALENCE, TO DATE WE LACK METHODS THAT ARE BOTH EFFICIENT AND ACCURATE IN DIAGNOSING ASTHMA. MOST TRADITIONAL APPROACHES HAVE BEEN BASED ON GARNERING CLINICAL EVIDENCE, SUCH AS RISK FACTORS AND EXPOSURES. GIVEN THE HIGH HERITABILITY OF ASTHMA, MORE RECENT APPROACHES HAVE LOOKED AT GENETIC POLYMORPHISMS AS POTENTIAL "RISK FACTORS." HOWEVER, GENETIC VARIANTS EXPLAIN ONLY A SMALL PROPORTION OF ASTHMA RISK, AND HAVE BEEN LESS THAN OPTIMAL AT PREDICTING RISK FOR INDIVIDUAL SUBJECTS. EPIGENOMIC STUDIES OFFER SIGNIFICANT ADVANTAGES OVER PREVIOUS APPROACHES. EPIGENETIC REGULATION IS HIGHLY TISSUE-SPECIFIC, AND CAN INDUCE BOTH SHORT- AND LONG-TERM CHANGES IN GENE EXPRESSION. SUCH CHANGES CAN START IN UTERO, CAN VARY THROUGHOUT THE LIFE SPAN, AND IN SOME INSTANCES CAN BE PASSED ON FROM ONE GENERATION TO ANOTHER. MOST IMPORTANTLY, THE EPIGENOME CAN BE MODIFIED BY ENVIRONMENTAL FACTORS AND EXPOSURES, AND THUS EPIGENETIC AND TRANSCRIPTOMIC PROFILING MAY YIELD THE MOST ACCURATE RISK ESTIMATES FOR A GIVEN PATIENT BY INCORPORATING ENVIRONMENTAL (AND TREATMENT) EFFECTS THROUGHOUT THE LIFESPAN. HERE WE WILL REVIEW THE MOST RECENT ADVANCES IN THE USE OF EPIGENETIC AND TRANSCRIPTOMIC ANALYSIS FOR THE EARLY DIAGNOSIS OF ASTHMA AND ATOPY, AS WELL AS CHALLENGES AND FUTURE DIRECTIONS IN THE FIELD AS IT MOVES FORWARD. WE WILL PARTICULARLY FOCUS ON DNA METHYLATION, THE MOST STUDIED MECHANISM OF EPIGENETIC REGULATION. 2019 13 6426 29 THE TRANSGENERATIONAL TRANSMISSION OF THE PATERNAL TYPE 2 DIABETES-INDUCED SUBFERTILITY PHENOTYPE. DIABETES IS A CHRONIC METABOLIC DISORDER CHARACTERIZED BY HYPERGLYCEMIA AND ASSOCIATED WITH MANY HEALTH COMPLICATIONS DUE TO THE LONG-TERM DAMAGE AND DYSFUNCTION OF VARIOUS ORGANS. A CONSEQUENTIAL COMPLICATION OF DIABETES IN MEN IS REPRODUCTIVE DYSFUNCTION, REDUCED FERTILITY, AND POOR REPRODUCTIVE OUTCOMES. HOWEVER, THE MOLECULAR MECHANISMS RESPONSIBLE FOR DIABETIC ENVIRONMENT-INDUCED SPERM DAMAGE AND OVERALL DECREASED REPRODUCTIVE OUTCOMES ARE NOT FULLY ESTABLISHED. WE EVALUATED THE EFFECTS OF TYPE 2 DIABETES EXPOSURE ON THE REPRODUCTIVE SYSTEM AND THE REPRODUCTIVE OUTCOMES OF MALES AND THEIR MALE OFFSPRING, USING A MOUSE MODEL. WE DEMONSTRATE THAT PATERNAL EXPOSURE TO TYPE 2 DIABETES MEDIATES INTERGENERATIONAL AND TRANSGENERATIONAL EFFECTS ON THE REPRODUCTIVE HEALTH OF THE OFFSPRING, ESPECIALLY ON SPERM QUALITY, AND ON METABOLIC CHARACTERISTICS. GIVEN THE TRANSGENERATIONAL IMPAIRMENT OF REPRODUCTIVE AND METABOLIC PARAMETERS THROUGH TWO GENERATIONS, THESE CHANGES LIKELY TAKE THE FORM OF INHERITED EPIGENETIC MARKS THROUGH THE GERMLINE. OUR RESULTS EMPHASIZE THE IMPORTANCE OF IMPROVING METABOLIC HEALTH NOT ONLY IN WOMEN OF REPRODUCTIVE AGE, BUT ALSO IN POTENTIAL FATHERS, IN ORDER TO REDUCE THE NEGATIVE IMPACTS OF DIABETES ON SUBSEQUENT GENERATIONS. 2021 14 3784 30 INTERGENERATIONAL EFFECTS OF ALCOHOL: A REVIEW OF PATERNAL PRECONCEPTION ETHANOL EXPOSURE STUDIES AND EPIGENETIC MECHANISMS IN THE MALE GERMLINE. WHILE ALCOHOL USE DISORDER (AUD) IS A HIGHLY HERITABLE PSYCHIATRIC DISEASE, EFFORTS TO ELUCIDATE THAT HERITABILITY BY EXAMINING GENETIC VARIATION (E.G., SINGLE NUCLEOTIDE POLYMORPHISMS) HAVE BEEN INSUFFICIENT TO FULLY ACCOUNT FOR FAMILIAL AUD RISK. PERHAPS NOT COINCIDENTLY, THERE HAS BEEN A BURGEONING INTEREST IN NOVEL NONGENOMIC MECHANISMS OF INHERITANCE (I.E., EPIGENETICS) THAT ARE SHAPED IN THE MALE OR FEMALE GERM CELLS BY SIGNIFICANT LIFETIME EXPERIENCES SUCH AS EXPOSURE TO CHRONIC STRESS, MALNUTRITION, OR DRUGS OF ABUSE. WHILE MANY EPIDEMIOLOGICAL AND PRECLINICAL STUDIES HAVE LONG POINTED TO A ROLE FOR THE PARENTAL PRECONCEPTION ENVIRONMENT IN OFFSPRING BEHAVIOR, OVER THE LAST DECADE MANY STUDIES HAVE IMPLICATED A CAUSAL RELATIONSHIP BETWEEN THE ENVIRONMENTALLY SENSITIVE SPERM EPIGENOME AND INTERGENERATIONAL PHENOTYPES. THIS CRITICAL REVIEW WILL DETAIL THE HERITABLE EFFECTS OF ALCOHOL AND THE POTENTIAL ROLE FOR EPIGENETICS. 2019 15 2159 30 EPIGENETIC MECHANISMS IMPACTED BY CHRONIC STRESS ACROSS THE RODENT LIFESPAN. EXPOSURES TO STRESS AT ALL STAGES OF DEVELOPMENT CAN LEAD TO LONG-TERM BEHAVIOURAL EFFECTS, IN PART THROUGH CHANGES IN THE EPIGENOME. THIS REVIEW DESCRIBES RODENT RESEARCH SUGGESTING THAT STRESS IN PRENATAL, POSTNATAL, ADOLESCENT AND ADULT STAGES LEADS TO LONG-TERM CHANGES IN EPIGENETIC REGULATION IN THE BRAIN WHICH HAVE CAUSAL IMPACTS ON RODENT BEHAVIOUR. WE FOCUS ON STRESS-INDUCED EPIGENETIC CHANGES THAT HAVE BEEN LINKED TO BEHAVIOURAL DEFICITS INCLUDING POOR LEARNING AND MEMORY, AND INCREASED ANXIETY-LIKE AND DEPRESSIVE-LIKE BEHAVIOURS. INTERESTINGLY, ASPECTS OF THESE STRESS-INDUCED BEHAVIOURAL CHANGES CAN BE TRANSMITTED TO OFFSPRING ACROSS SEVERAL GENERATIONS, A PHENOMENON THAT HAS BEEN PROPOSED TO RESULT VIA EPIGENETIC MECHANISMS IN THE GERMLINE. HERE, WE ALSO DISCUSS EVIDENCE FOR THE DIFFERENTIAL IMPACT OF STRESS ON THE EPIGENOME IN MALES AND FEMALES, CONSCIOUS OF THE FACT THAT THE MAJORITY OF PUBLISHED STUDIES HAVE ONLY INVESTIGATED MALES. THIS HAS LED TO A LIMITED PICTURE OF THE EPIGENETIC IMPACT OF STRESS, HIGHLIGHTING THE NEED FOR FUTURE STUDIES TO INVESTIGATE FEMALES AS WELL AS MALES. 2022 16 4996 26 PERINATAL EPIGENETIC DETERMINANTS OF COGNITIVE AND METABOLIC DISORDERS. MULTIPLE CUES FROM THE ENVIRONMENT OF OUR INDIRECT AND IMMEDIATE ANCESTORS, WHICH OFTEN PERSIST THROUGHOUT THE PRENATAL PERIOD AND ADULTHOOD, ARE SHAPING OUR PHENOTYPES THROUGH EITHER DIRECT, PARENT-TO-CHILD INFLUENCES, OR TRANSGENERATIONAL INHERITANCE. THESE EFFECTS ARE DUE TO GENE-ENVIRONMENT INTERACTIONS, WHICH ARE INTENDED TO BE A PREDICTIVE TOOL AND A MECHANISM OF QUICK ADAPTATION TO THE ENVIRONMENT, AS COMPARED WITH GENETIC VARIATIONS THAT ARE INHERITED OVER MANY GENERATIONS. IN CERTAIN CIRCUMSTANCES THE INFLUENCES INDUCED BY THE GENE-ENVIRONMENT INTERACTIONS CAN HAVE DELETERIOUS EFFECTS UPON THE HEALTH STATUS, IN THE CONTEXT OF A RADICAL CHANGE IN THE ENVIRONMENT THAT DOES NOT FIT WITH THE PREDICTED CONDITIONS, VIA EPIGENETIC ALTERATIONS. CONVERSELY THE BEST FIT TO THE EXPECTED ENVIRONMENT MIGHT HAVE A DELAYED AGING PROCESS AND A LONGER LIFE SPAN. THIS REVIEW WILL TOUCH UPON THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE (DOHAD) CONCEPT, WHILE DISCUSSING RECENT ADVANCES IN THE UNDERSTANDING OF METABOLIC AND COGNITIVE DISRUPTIONS, WITH A FOCUS ON EPIGENETIC FACTORS, THEIR TRANSGENERATIONAL EFFECTS, AND THE CONSEQUENCES THEY MIGHT HAVE UPON THE ONSET OF CHRONIC DISEASE AND PREMATURE EXITUS. 2012 17 5650 24 SEX DIFFERENCES IN THE DEVELOPMENT OF PHYSICAL AGGRESSION: AN INTERGENERATIONAL PERSPECTIVE AND IMPLICATIONS FOR PREVENTIVE INTERVENTIONS. THIS ARTICLE REVIEWS THE STATE OF KNOWLEDGE ON THE DEVELOPMENT OF CHRONIC PHYSICAL AGGRESSION (CPA), WITH THE AIM OF IDENTIFYING THE MOST EFFECTIVE PREVENTION STRATEGIES. WE SPECIFICALLY FOCUS ON THE EARLY DEVELOPMENT OF PHYSICAL AGGRESSION, ON SEX DIFFERENCES IN THE USE OF PHYSICAL AGGRESSION, AND ON THE TRANSMISSION OF BEHAVIOR PROBLEMS FROM ONE GENERATION TO THE OTHER. THE BODY OF RESEARCH ON THE DEVELOPMENT OF CPA FROM THE PAST THREE DECADES THAT WE REVIEW SHOWS INCREASING EVIDENCE THAT ITS PREVENTION REQUIRES A LONG-TERM BIOPSYCHOSOCIAL DEVELOPMENTAL APPROACH WHICH ALSO MUST INCLUDE AN INTERGENERATIONAL PERSPECTIVE. RECENT GENETIC AND EPIGENETIC RESEARCH HAS INDICATED THAT THERE ARE BOTH IMPORTANT GENETIC AND ENVIRONMENTAL EFFECTS ON GENE EXPRESSION WHICH START AT CONCEPTION. WE CONCLUDE THAT ONE OF THE MOST EFFECTIVE STRATEGIES TO BREAK THE INTERGENERATIONAL TRANSMISSION OF CPA INVOLVES GIVING LONG-TERM SUPPORT TO PREGNANT WOMEN WITH A HISTORY OF BEHAVIOR PROBLEMS, THEIR SPOUSE, AND THEIR OFFSPRING. 2019 18 2901 36 GENDER DIFFERENCES IN GERM-CELL MUTAGENESIS AND GENETIC RISK. CURRENT INTERNATIONAL CLASSIFICATION SYSTEMS FOR CHEMICAL MUTAGENS ARE HAZARD-BASED RATHER THAN AIMED AT ASSESSING RISKS QUANTITATIVELY. IN THE PAST, GERM-CELL TESTS HAVE BEEN MAINLY PERFORMED WITH A LIMITED NUMBER OF SOMATIC CELL MUTAGENS, AND RARELY UNDER CONDITIONS AIMED AT COMPARING GENDER-SPECIFIC DIFFERENCES IN SUSCEPTIBILITY TO MUTAGEN EXPOSURES. THERE ARE PROFOUND DIFFERENCES IN THE GENETIC CONSTITUTION, AND IN HORMONAL, STRUCTURAL, AND FUNCTIONAL ASPECTS OF DIFFERENTIATION AND CONTROL OF GAMETOGENESIS BETWEEN THE SEXES. A CRITICAL REVIEW OF THE LITERATURE SUGGESTS THAT THESE DIFFERENCES MAY HAVE A PROFOUND IMPACT ON THE RELATIVE SUSCEPTIBILITY, STAGE OF HIGHEST SENSITIVITY AND THE RELATIVE RISK FOR THE GENESIS OF GENE MUTATION, AS WELL AS STRUCTURAL AND NUMERICAL CHROMOSOMAL ABERRATIONS IN MALE AND FEMALE GERM CELLS. TRANSMISSION OF GERM-CELL MUTATIONS TO THE OFFSPRING MAY ALSO ENCOUNTER GENDER-SPECIFIC INFLUENCES. GENDER DIFFERENCES IN SUSCEPTIBILITY TO CHEMICALLY DERIVED ALTERATIONS IN IMPRINTING PATTERNS MAY POSE A THREAT FOR THE HEALTH OF THE OFFSPRING AND MAY ALSO BE TRANSMITTED TO FUTURE GENERATIONS. RECENT REPORTS ON DIFFERENT GENETIC EFFECTS FROM HIGH ACUTE AND FROM CHRONIC LOW-DOSE EXPOSURES CHALLENGE THE VALIDITY OF CONCLUSIONS DRAWN FROM STANDARD METHODS OF MUTAGENICITY TESTING. IN CONCLUSION, RESEARCH IS URGENTLY NEEDED TO IDENTIFY GENETIC HAZARDS FOR A LARGER RANGE OF CHEMICAL COMPOUNDS, INCLUDING THOSE SUSPECTED TO DISTURB PROPER CHROMOSOME SEGREGATION. ALTERATIONS IN EPIGENETIC PROGRAMMING AND THEIR HEALTH CONSEQUENCES WILL HAVE TO BE INVESTIGATED. MORE ATTENTION SHOULD BE PAID TO GENDER-SPECIFIC GENETIC EFFECTS. FINALLY, THE DATABASE FOR GERM-CELL MUTAGENS SHOULD BE ENLARGED USING MOLECULAR METHODOLOGIES, AND GENETIC EPIDEMIOLOGY STUDIES SHOULD BE PERFORMED WITH THESE TECHNIQUES TO VERIFY HUMAN GENETIC RISK. 2007 19 6065 28 THE DEVELOPMENTAL ORIGINS OF CHRONIC PHYSICAL AGGRESSION: BIOLOGICAL PATHWAYS TRIGGERED BY EARLY LIFE ADVERSITY. LONGITUDINAL EPIDEMIOLOGICAL STUDIES WITH BIRTH COHORTS HAVE SHOWN THAT PHYSICAL AGGRESSION IN HUMANS DOES NOT APPEAR SUDDENLY IN ADOLESCENCE AS COMMONLY THOUGHT. IN FACT, PHYSICALLY AGGRESSIVE BEHAVIOUR IS OBSERVED AS EARLY AS 12 MONTHS AFTER BIRTH, ITS FREQUENCY PEAKS AROUND 2-4 YEARS OF AGE AND DECREASES IN FREQUENCY UNTIL EARLY ADULTHOOD. HOWEVER, A MINORITY OF CHILDREN (3-7%) MAINTAIN A HIGH FREQUENCY OF PHYSICAL AGGRESSION FROM CHILDHOOD TO ADOLESCENCE AND DEVELOP SERIOUS SOCIAL ADJUSTMENT PROBLEMS DURING ADULTHOOD. GENETIC FACTORS AND EARLY SOCIAL EXPERIENCES, AS WELL AS THEIR INTERACTION, HAVE BEEN SHOWN TO PLAY AN IMPORTANT ROLE IN THE DEVELOPMENT OF CHRONIC AGGRESSIVE BEHAVIOUR. HOWEVER, THE BIOLOGICAL MECHANISMS UNDERLYING THESE ASSOCIATIONS ARE JUST BEGINNING TO BE UNCOVERED. RECENT EVIDENCE SUGGESTS THAT EPIGENETIC MECHANISMS ARE RESPONSIVE TO ADVERSE ENVIRONMENTS AND COULD BE INVOLVED IN THE DEVELOPMENT OF CHRONIC AGGRESSION. USING BOTH GENE CANDIDATE AND GENOMIC APPROACHES, RECENT STUDIES HAVE IDENTIFIED EPIGENETIC MARKS, SUCH AS DNA METHYLATION ALTERATIONS IN GENES INVOLVED IN THE STRESS RESPONSE AND THE SEROTONIN AND IMMUNE SYSTEMS TO BE PARTLY RESPONSIBLE FOR THE LONG-LASTING EFFECTS OF EARLY ADVERSITY. FURTHER LONGITUDINAL STUDIES WITH BIOLOGICAL, ENVIRONMENTAL AND BEHAVIOURAL ASSESSMENTS FROM BIRTH ONWARDS ARE NEEDED TO ELUCIDATE THE SEQUENCE OF EVENTS THAT LEADS TO THESE LONG-LASTING EPIGENETIC MARKS ASSOCIATED WITH EARLY ADVERSITY AND AGGRESSION. 2015 20 1324 35 DEOXYRIBONUCLEIC ACID (DNA) METHYLATION IN CHILDREN EXPOSED TO AIR POLLUTION: A POSSIBLE MECHANISM UNDERLYING RESPIRATORY HEALTH EFFECTS DEVELOPMENT. AIR POLLUTION IS A SUBSTANTIAL ENVIRONMENTAL THREAT TO CHILDREN AND ACTS AS ACUTE AND CHRONIC DISEASE RISK FACTORS ALIKE. SEVERAL STUDIES HAVE PREVIOUSLY EVALUATED EPIGENETIC MODIFICATIONS CONCERNING ITS EXPOSURE ACROSS VARIOUS LIFE STAGES. HOWEVER, FINDINGS ON EPIGENETIC MODIFICATIONS AS THE CONSEQUENCES OF AIR POLLUTION DURING CHILDHOOD ARE RATHER MINIMAL. THIS REVIEW EVALUATED HIGHLY RELEVANT STUDIES IN THE FIELD TO ANALYZE THE EXISTING LITERATURE REGARDING EXPOSURE TO AIR POLLUTION, WITH A FOCUS ON EPIGENETIC ALTERATIONS DURING CHILDHOOD AND THEIR CONNECTIONS WITH RESPIRATORY HEALTH EFFECTS. THE SEARCH WAS CONDUCTED USING READILY AVAILABLE ELECTRONIC DATABASES (PUBMED AND SCIENCEDIRECT) TO SCREEN FOR CHILDREN'S STUDIES ON EPIGENETIC MECHANISMS FOLLOWING EITHER PRE- OR POST-NATAL EXPOSURE TO AIR POLLUTANTS. STUDIES RELEVANT ENOUGH AND MATCHED THE PREDETERMINED CRITERIA WERE CHOSEN TO BE REVIEWED. NON-ENGLISH ARTICLES AND STUDIES THAT DID NOT REPORT BOTH AIR MONITORING AND EPIGENETIC OUTCOMES IN THE SAME ARTICLE WERE EXCLUDED. THE REVIEW FOUND THAT EPIGENETIC CHANGES HAVE BEEN LINKED WITH EXPOSURE TO AIR POLLUTANTS DURING EARLY LIFE WITH EVIDENCE AND REPORTS OF HOW THEY MAY DEREGULATE THE EPIGENOME BALANCE, THUS INDUCING DISEASE PROGRESSION IN THE FUTURE. EPIGENETIC STUDIES EVOLVE AS A PROMISING NEW APPROACH IN DECIPHERING THE UNDERLYING IMPACTS OF AIR POLLUTION ON DEOXYRIBONUCLEIC ACID (DNA) DUE TO LINKS ESTABLISHED BETWEEN SOME OF THESE EPIGENETIC MECHANISMS AND ILLNESSES. 2021