1 754 148 CARDIOVASCULAR ADAPTATIONS TO PARTICLE INHALATION EXPOSURE: MOLECULAR MECHANISMS OF THE TOXICOLOGY. AMBIENT AIR, OCCUPATIONAL SETTINGS, AND THE USE AND DISTRIBUTION OF CONSUMER PRODUCTS ALL SERVE AS CONDUITS FOR TOXICANT EXPOSURE THROUGH INHALATION. WHILE THE PULMONARY SYSTEM REMAINS A PRIMARY TARGET FOLLOWING INHALATION EXPOSURE, CARDIOVASCULAR IMPLICATIONS ARE EXCEPTIONALLY CULPABLE FOR INCREASED MORBIDITY AND MORTALITY. THE EPIDEMIOLOGICAL EVIDENCE FOR CARDIOVASCULAR DYSFUNCTION RESULTING FROM ACUTE OR CHRONIC INHALATION EXPOSURE TO PARTICULATE MATTER HAS BEEN WELL DOCUMENTED, BUT THE MECHANISMS DRIVING THE RESULTING DISTURBANCES REMAIN ELUSIVE. IN THE CURRENT REVIEW, WE AIM TO SUMMARIZE THE CELLULAR AND MOLECULAR MECHANISMS THAT ARE DIRECTLY LINKED TO CARDIOVASCULAR HEALTH FOLLOWING EXPOSURE TO A VARIETY OF INHALED TOXICANTS. THE PURPOSE OF THIS REVIEW IS TO PROVIDE A COMPREHENSIVE OVERVIEW OF THE BIOCHEMICAL CHANGES IN THE CARDIOVASCULAR SYSTEM FOLLOWING PARTICLE INHALATION EXPOSURE AND TO HIGHLIGHT POTENTIAL BIOMARKERS THAT EXIST ACROSS MULTIPLE EXPOSURE PARADIGMS. WE ATTEMPT TO INTEGRATE THESE MOLECULAR SIGNATURES IN AN EFFORT TO PROVIDE DIRECTION FOR FUTURE INVESTIGATIONS. THIS REVIEW ALSO CHARACTERIZES HOW MOLECULAR RESPONSES ARE MODIFIED IN AT-RISK POPULATIONS, SPECIFICALLY THE IMPACT OF ENVIRONMENTAL EXPOSURE DURING CRITICAL WINDOWS OF DEVELOPMENT. MATERNAL EXPOSURE TO PARTICULATE MATTER DURING GESTATION CAN LEAD TO FETAL EPIGENETIC REPROGRAMMING, RESULTING IN LONG-TERM DEFICITS TO THE CARDIOVASCULAR SYSTEM. IN BOTH DIRECT AND INDIRECT (GESTATIONAL) EXPOSURES, CONNECTING THE BIOCHEMICAL MECHANISMS WITH FUNCTIONAL DEFICITS OUTLINES PATHWAYS THAT CAN BE TARGETED FOR FUTURE THERAPEUTIC INTERVENTION. ULTIMATELY, FUTURE INVESTIGATIONS INTEGRATING "OMICS"-BASED APPROACHES WILL BETTER ELUCIDATE THE MECHANISMS THAT ARE ALTERED BY XENOBIOTIC INHALATION EXPOSURE, IDENTIFY BIOMARKERS, AND GUIDE IN CLINICAL DECISION MAKING. 2020 2 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 3 3582 26 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 4 6295 44 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 6781 50 [BREATHING: AMBIENT AIR POLLUTION AND HEALTH - PART III]. THE THIRD PART OF THE DGP STATEMENT INTRODUCES THE CURRENT BODY OF KNOWLEDGE ON LESS STUDIED HEALTH OUTCOMES ASSOCIATED WITH EXPOSURE TO AMBIENT AIR POLLUTION: THE NEGATIVE IMPACT ON METABOLISM LEADING TO IMPAIRED GLUCOSE TOLERANCE AND DIABETES AS WELL AS CONTRIBUTION TO THE DEVELOPMENT OF NEURODEGENERATIVE DISORDERS AND DELAYED COGNITIVE FUNCTION IN CHILDREN. FURTHERMORE, PRENATAL EXPOSURE AND ADVERSE EFFECTS ON MOTHER AND CHILD ARE ADDRESSED. FINALLY, THE CURRENTLY DISCUSSED BIOLOGICAL MECHANISMS UNDERLYING VARIOUS HEALTH EFFECTS ASSOCIATED WITH EXPOSURE TO AIR POLLUTION ARE DESCRIBED.DIFFERING, BUT OFTEN COMPLEMENTARY BIOLOGICAL MECHANISMS CREATE THE BASIS FOR THE DIVERSE HEALTH OUTCOMES CAUSED BY AIR POLLUTION. OXIDATIVE STRESS AND A SUBCLINICAL INFLAMMATORY RESPONSE IN THE LUNGS AND ON A SYSTEMIC LEVEL ("LOW-GRADE SYSTEMIC INFLAMMATION") ARE CONSIDERED TO BE KEY MECHANISMS. THEY PROMOTE SECONDARY ALTERATIONS IN THE BODY, SUCH AS VASCULAR OR METABOLIC PROCESSES, AND MAY ALSO RESULT IN THE CURRENTLY STUDIED EPIGENETIC PHENOMENA OR NEUROINFLAMMATION. IN THIS CONTEXT, THE HEALTH SIGNIFICANCE OF SOLUBLE PARTICULATE MATTER AND THE ROLE OF ULTRAFINE PARTICLES TRANSLOCATED ACROSS BIOLOGICAL MEMBRANES INTO BLOOD VESSEL AND TRANSPORTED VIA THE CIRCULATION TO SECONDARY TARGET ORGANS, SUCH AS LIVER, BRAIN OR THE FETUS, ARE INTENSIVELY DISCUSSED.DIABETES IS ONE OF THE LEADING CHRONIC DISEASES WORLDWIDE, WITH A PREVALENCE OF ALMOST 14 % IN GERMANY. ALTHOUGH LIFESTYLE FACTORS ARE THE MAIN CAUSES, CURRENT EVIDENCE SUGGESTS THAT LONG-TERM EXPOSURE TO AIR POLLUTION MAY ADDITIONALLY INCREASE THE RISK FOR TYPE 2 DIABETES. SUPPORTING EVIDENCE FOR A CAUSAL ROLE OF AIR POLLUTION IS PROVIDED BY STUDIES ADDRESSING THE REGULATION OF THE BLOOD GLUCOSE LEVELS IN METABOLICALLY HEALTHY PARTICIPANTS, INSULIN SENSITIVITY, OR PREGNANCY-RELATED DIABETES. EXPERIMENTAL STUDIES PROVIDE FURTHER SUPPORT FOR PLAUSIBLE BIOLOGICAL MECHANISMS. HOWEVER, PROSPECTIVE STUDIES ARE NEEDED TO GAIN MORE EVIDENCE, TAKING MULTIPLE LIFESTYLE AND ENVIRONMENTAL FACTORS, SUCH AS GREEN SPACE AND NOISE, AND AN IMPROVED INDIVIDUAL EXPOSURE ASSESSMENT INTO ACCOUNT.THE AGING POPULATION HAS AN INCREASED RISK OF NEURODEGENERATIVE DISEASES. FIRST STUDIES POINT TOWARDS A CONTRIBUTION OF CHRONIC EXPOSURE TO AIR POLLUTION, SPECIFICALLY BY PARTICULATE MATTER. SEVERAL STUDIES REPORT ITS ASSOCIATION WITH DECREASED NEUROCOGNITIVE CAPACITY OR AN INCREASED PREVALENCE OF DEMENTIA OR ALZHEIMER'S DISEASE IN ADULTS. HOWEVER, THE STUDIES ARE INHOMOGENEOUS REGARDING DESIGN, EXPOSURE AND OUTCOME, LEADING TO INCONSISTENT RESULTS. WITH RESPECT TO THE INFLUENCE ON NEUROCOGNITIVE DEVELOPMENT OF CHILDREN, FIRST STUDIES SUGGEST AN ASSOCIATION BETWEEN THE LEVEL OF AIR POLLUTION, E. G. AT SCHOOL, AND DELAYED COGNITIVE DEVELOPMENT.EVEN THOUGH THE EVIDENCE FOR THE DIFFERENT BIOLOGICAL ENDPOINTS DURING PREGNANCY IS STILL HETEROGENEOUS, THE STUDIES GENERALLY POINT TOWARDS AN ADVERSE IMPACT OF AIR POLLUTION ON THE MATERNAL AND FETAL ORGANISMS. THE STRONGEST EVIDENCE EXISTS FOR LOW BIRTH WEIGHT, WITH SMALL EFFECT SIZES OF ONLY SOME GRAMS, AND FOR A HIGHER INCIDENCE OF REDUCED BIRTH WEIGHT (< 2500 G). AN INCREASED RISK FOR GESTATIONAL HYPERTENSION AND PREECLAMPSIA UNDERSCORES THE POSSIBLE IMPACT OF EXPOSURE TO AIR POLLUTION ON THE MATERNAL ORGANISM. HOWEVER, THE CURRENT BODY OF EVIDENCE DOES NOT YET ALLOW A FINAL CONCLUSION ON THE INFLUENCE OF INTRAUTERINE EXPOSURE TO AIR POLLUTION REGARDING EARLY CHILDHOOD LUNG FUNCTION AND DEVELOPMENT OF ALLERGIES, PARTICULARLY IN LIGHT OF THE FACT THAT IT IS HARD TO DISTINGUISH IN EPIDEMIOLOGICAL STUDIES BETWEEN THE EFFECTS OF PRE- AND POSTNATAL EXPOSURE. 2019 6 5434 30 RELATIONSHIP BETWEEN ENVIRONMENTAL EXPOSURES IN CHILDREN AND ADULT LUNG DISEASE: THE CASE FOR OUTDOOR EXPOSURES. THERE IS A GROWING UNDERSTANDING THAT CHRONIC RESPIRATORY DISEASES IN ADULTS HAVE THEIR ORIGINS IN EARLY LIFE. ADVERSE ENVIRONMENTAL EXPOSURES OCCURRING IN VULNERABLE PERIODS DURING LUNG GROWTH AND DEVELOPMENT IN THE FETAL PERIOD AND IN EARLY CHILDHOOD THAT ALTER LUNG STRUCTURE AND LIMIT THE GROWTH IN LUNG FUNCTION MAY HAVE LIFELONG CONSEQUENCES. EVIDENCE IS INCREASING THAT EXPOSURE TO THE AMBIENT ENVIRONMENT, INCLUDING AIR POLLUTANTS, PERSISTENT TOXIC SUBSTANCES, WATER POLLUTANTS AND RESPIRATORY VIRAL INFECTIONS, CAN INHIBIT LUNG FUNCTION GROWTH AND PREDISPOSE TO CHRONIC NON-MALIGNANT LUNG DISEASES. THESE EXPOSURES GENERALLY INTERACT WITH A GENETIC PREDISPOSITION, AND GENE-ENVIRONMENT INTERACTIONS AND EPIGENETIC PHENOMENA ARE ATTRACTING CONSIDERABLE STUDY. AN UNDERSTANDING OF HOW AMBIENT EXPOSURES IMPACT ON NORMAL LUNG GROWTH AND DEVELOPMENT WILL AID IN UNDERSTANDING OF HOW CHRONIC RESPIRATORY DISEASES OF ADULTS DEVELOP AND MAY LEAD TO NEW PREVENTATIVE STRATEGIES. 2010 7 6287 45 THE POTENTIAL ROLE OF ENVIRONMENTAL FACTORS IN MODULATING MITOCHONDRIAL DNA EPIGENETIC MARKS. MANY STUDIES IMPLICATE MITOCHONDRIAL DYSFUNCTION IN THE DEVELOPMENT AND PROGRESSION OF NUMEROUS CHRONIC DISEASES. MITOCHONDRIA ARE RESPONSIBLE FOR MOST CELLULAR ENERGY PRODUCTION, AND UNLIKE OTHER CYTOPLASMIC ORGANELLES, MITOCHONDRIA CONTAIN THEIR OWN GENOME. MOST RESEARCH TO DATE, THROUGH INVESTIGATING MITOCHONDRIAL DNA COPY NUMBER, HAS FOCUSED ON LARGER STRUCTURAL CHANGES OR ALTERATIONS TO THE ENTIRE MITOCHONDRIAL GENOME AND THEIR ROLE IN HUMAN DISEASE. USING THESE METHODS, MITOCHONDRIAL DYSFUNCTION HAS BEEN LINKED TO CANCERS, CARDIOVASCULAR DISEASE, AND METABOLIC HEALTH. HOWEVER, LIKE THE NUCLEAR GENOME, THE MITOCHONDRIAL GENOME MAY EXPERIENCE EPIGENETIC ALTERATIONS, INCLUDING DNA METHYLATION THAT MAY PARTIALLY EXPLAIN SOME OF THE HEALTH EFFECTS OF VARIOUS EXPOSURES. RECENTLY, THERE HAS BEEN A MOVEMENT TO UNDERSTAND HUMAN HEALTH AND DISEASE WITHIN THE CONTEXT OF THE EXPOSOME, WHICH AIMS TO DESCRIBE AND QUANTIFY THE ENTIRETY OF ALL EXPOSURES PEOPLE ENCOUNTER THROUGHOUT THEIR LIVES. THESE INCLUDE, AMONG OTHERS, ENVIRONMENTAL POLLUTANTS, OCCUPATIONAL EXPOSURES, HEAVY METALS, AND LIFESTYLE AND BEHAVIORAL FACTORS. IN THIS CHAPTER, WE SUMMARIZE THE CURRENT RESEARCH ON MITOCHONDRIA AND HUMAN HEALTH, PROVIDE AN OVERVIEW OF THE CURRENT KNOWLEDGE ON MITOCHONDRIAL EPIGENETICS, AND DESCRIBE THE EXPERIMENTAL AND EPIDEMIOLOGIC STUDIES THAT HAVE INVESTIGATED PARTICULAR EXPOSURES AND THEIR RELATIONSHIPS WITH MITOCHONDRIAL EPIGENETIC MODIFICATIONS. WE CONCLUDE THE CHAPTER WITH SUGGESTIONS FOR FUTURE DIRECTIONS IN EPIDEMIOLOGIC AND EXPERIMENTAL RESEARCH THAT IS NEEDED TO ADVANCE THE GROWING FIELD OF MITOCHONDRIAL EPIGENETICS. 2023 8 396 36 AN UPDATE ON EPIGENETICS AND CHILDHOOD RESPIRATORY DISEASES. EPIGENETIC MECHANISMS, DEFINED AS CHANGES IN PHENOTYPE OR GENE EXPRESSION CAUSED BY MECHANISMS OTHER THAN CHANGES IN THE UNDERLYING DNA SEQUENCE, HAVE BEEN PROPOSED TO CONSTITUTE A LINK BETWEEN GENETIC AND ENVIRONMENTAL FACTORS THAT AFFECT COMPLEX DISEASES. RECENT STUDIES SHOW THAT DNA METHYLATION, ONE OF THE KEY EPIGENETIC MECHANISMS, IS ALTERED IN CHILDREN EXPOSED TO AIR POLLUTANTS AND ENVIRONMENTAL TOBACCO SMOKE EARLY IN LIFE. SEVERAL CANDIDATE GENE STUDIES ON EPIGENETICS HAVE BEEN PUBLISHED TO DATE, BUT IT IS ONLY RECENTLY THAT GLOBAL METHYLATION ANALYSES HAVE BEEN PERFORMED FOR RESPIRATORY DISORDERS SUCH AS ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE. HOWEVER, LARGE-SCALE STUDIES WITH ADEQUATE POWER ARE YET TO BE PRESENTED IN CHILDREN, AND IMPLICATIONS FOR CLINICAL USE REMAIN TO BE EVALUATED. IN THIS REVIEW, WE SUMMARIZE THE RECENT ADVANCES IN EPIGENETICS AND RESPIRATORY DISORDERS IN CHILDREN, WITH A MAIN FOCUS ON METHODOLOGICAL CHALLENGES AND ANALYSES RELATED TO PHENOTYPE AND EXPOSURE USING GLOBAL METHYLATION APPROACHES. 2014 9 4460 32 MOLECULAR MECHANISMS OF ENVIRONMENTAL EXPOSURES AND HUMAN DISEASE. A SUBSTANTIAL PROPORTION OF DISEASE RISK FOR COMMON COMPLEX DISORDERS IS ATTRIBUTABLE TO ENVIRONMENTAL EXPOSURES AND POLLUTANTS. AN APPRECIATION OF HOW ENVIRONMENTAL POLLUTANTS ACT ON OUR CELLS TO PRODUCE DELETERIOUS HEALTH EFFECTS HAS LED TO ADVANCES IN OUR UNDERSTANDING OF THE MOLECULAR MECHANISMS UNDERLYING THE PATHOGENESIS OF CHRONIC DISEASES, INCLUDING CANCER AND CARDIOVASCULAR, NEURODEGENERATIVE AND RESPIRATORY DISEASES. HERE, WE DISCUSS EMERGING RESEARCH ON THE INTERPLAY OF ENVIRONMENTAL POLLUTANTS WITH THE HUMAN GENOME AND EPIGENOME. WE REVIEW EVIDENCE SHOWING THE ENVIRONMENTAL IMPACT ON GENE EXPRESSION THROUGH EPIGENETIC MODIFICATIONS, INCLUDING DNA METHYLATION, HISTONE MODIFICATION AND NON-CODING RNAS. WE ALSO HIGHLIGHT RECENT STUDIES THAT EVALUATE RECENTLY DISCOVERED MOLECULAR PROCESSES THROUGH WHICH THE ENVIRONMENT CAN EXERT ITS EFFECTS, INCLUDING EXTRACELLULAR VESICLES, THE EPITRANSCRIPTOME AND THE MITOCHONDRIAL GENOME. FINALLY, WE DISCUSS CURRENT CHALLENGES WHEN STUDYING THE EXPOSOME - THE CUMULATIVE MEASURE OF ENVIRONMENTAL INFLUENCES OVER THE LIFESPAN - AND ITS INTEGRATION INTO FUTURE ENVIRONMENTAL HEALTH RESEARCH. 2023 10 1932 30 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 11 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 12 3404 35 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 13 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 14 6183 35 THE IMPACT OF ENVIRONMENTAL FACTORS IN INFLUENCING EPIGENETICS RELATED TO OXIDATIVE STATES IN THE CARDIOVASCULAR SYSTEM. OXIDATIVE STATES EXERT A SIGNIFICANT INFLUENCE ON A WIDE RANGE OF BIOLOGICAL AND MOLECULAR PROCESSES AND FUNCTIONS. WHEN THEIR BALANCE IS SHIFTED TOWARDS ENHANCED AMOUNTS OF FREE RADICALS, PATHOLOGICAL PHENOMENA CAN OCCUR, AS THE GENERATION OF REACTIVE OXYGEN SPECIES (ROS) IN TISSUE MICROENVIRONMENT OR IN THE SYSTEMIC CIRCULATION CAN BE DETRIMENTAL. EPIDEMIC CHRONIC DISEASES OF WESTERN SOCIETIES, SUCH AS CARDIOVASCULAR DISEASE, OBESITY, AND DIABETES CORRELATE WITH THE IMBALANCE OF REDOX HOMEOSTASIS. CURRENT ADVANCES IN OUR UNDERSTANDING OF EPIGENETICS HAVE REVEALED A PARALLEL SCENARIO SHOWING THE INFLUENCE OF OXIDATIVE STRESS AS A MAJOR REGULATOR OF EPIGENETIC GENE REGULATION VIA MODIFICATION OF DNA METHYLATION, HISTONES, AND MICRORNAS. THIS HAS PROVIDED BOTH THE BIOLOGICAL LINK AND A POTENTIAL MOLECULAR EXPLANATION BETWEEN OXIDATIVE STRESS AND CARDIOVASCULAR/METABOLIC PHENOMENA. ACCORDINGLY, IN THIS REVIEW, WE WILL PROVIDE CURRENT INSIGHTS ON THE PHYSIOLOGICAL AND PATHOLOGICAL IMPACT OF CHANGES IN OXIDATIVE STATES ON CARDIOVASCULAR DISORDERS, BY SPECIFICALLY FOCUSING ON THE INFLUENCE OF EPIGENETIC REGULATION. A SPECIAL EMPHASIS WILL HIGHLIGHT THE EFFECT ON EPIGENETIC REGULATION OF HUMAN'S CURRENT LIFE HABITS, EXTERNAL AND ENVIRONMENTAL FACTORS, INCLUDING FOOD INTAKE, TOBACCO, AIR POLLUTION, AND ANTIOXIDANT-BASED APPROACHES. ADDITIONALLY, THE STRATEGY TO QUANTIFY OXIDATIVE STATES IN HUMANS IN ORDER TO DETERMINE WHICH BIOLOGICAL MARKER COULD BEST MATCH A SUBJECT'S PROFILE WILL BE DISCUSSED. 2017 15 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 16 3848 30 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 17 4626 36 NEURODEVELOPMENTAL DISORDERS AND ENVIRONMENTAL TOXICANTS: EPIGENETICS AS AN UNDERLYING MECHANISM. THE INCREASING PREVALENCE OF NEURODEVELOPMENTAL DISORDERS, ESPECIALLY AUTISM SPECTRUM DISORDERS (ASD) AND ATTENTION DEFICIT HYPERACTIVITY DISORDER (ADHD), CALLS FOR MORE RESEARCH INTO THE IDENTIFICATION OF ETIOLOGIC AND RISK FACTORS. THE DEVELOPMENTAL ORIGIN OF HEALTH AND DISEASE (DOHAD) HYPOTHESIZES THAT THE ENVIRONMENT DURING FETAL AND CHILDHOOD DEVELOPMENT AFFECTS THE RISK FOR MANY CHRONIC DISEASES IN LATER STAGES OF LIFE, INCLUDING NEURODEVELOPMENTAL DISORDERS. EPIGENETICS, A TERM DESCRIBING MECHANISMS THAT CAUSE CHANGES IN THE CHROMOSOME STATE WITHOUT AFFECTING DNA SEQUENCES, IS SUGGESTED TO BE THE UNDERLYING MECHANISM, ACCORDING TO THE DOHAD HYPOTHESIS. MOREOVER, MANY NEURODEVELOPMENTAL DISORDERS ARE ALSO RELATED TO EPIGENETIC ABNORMALITIES. EXPERIMENTAL AND EPIDEMIOLOGICAL STUDIES SUGGEST THAT EXPOSURE TO PRENATAL ENVIRONMENTAL TOXICANTS IS ASSOCIATED WITH NEURODEVELOPMENTAL DISORDERS. IN ADDITION, THERE IS ALSO EVIDENCE THAT ENVIRONMENTAL TOXICANTS CAN RESULT IN EPIGENETIC ALTERATIONS, NOTABLY DNA METHYLATION. IN THIS REVIEW, WE FIRST FOCUS ON THE RELATIONSHIP BETWEEN NEURODEVELOPMENTAL DISORDERS AND ENVIRONMENTAL TOXICANTS, IN PARTICULAR MATERNAL SMOKING, PLASTIC-DERIVED CHEMICALS (BISPHENOL A AND PHTHALATES), PERSISTENT ORGANIC POLLUTANTS, AND HEAVY METALS. WE THEN REVIEW STUDIES SHOWING THE EPIGENETIC EFFECTS OF THOSE ENVIRONMENTAL FACTORS IN HUMANS THAT MAY AFFECT NORMAL NEURODEVELOPMENT. 2017 18 1360 38 DEVELOPMENTAL ASPECTS OF A LIFE COURSE APPROACH TO HEALTHY AGEING. WE EXAMINE THE MECHANISTIC BASIS AND WIDER IMPLICATIONS OF ADOPTING A DEVELOPMENTAL PERSPECTIVE ON HUMAN AGEING. PREVIOUS MODELS OF AGEING HAVE CONCENTRATED ON ITS GENETIC BASIS, OR THE DETRIMENTAL EFFECTS OF ACCUMULATED DAMAGE, BUT ALSO HAVE RAISED ISSUES ABOUT WHETHER AGEING CAN BE VIEWED AS ADAPTIVE ITSELF, OR IS A CONSEQUENCE OF OTHER ADAPTIVE PROCESSES, FOR EXAMPLE IF MAINTENANCE AND REPAIR PROCESSES IN THE PERIOD UP TO REPRODUCTION ARE TRADED OFF AGAINST LATER DECLINE IN FUNCTION. A LIFE COURSE MODEL PLACES AGEING IN THE CONTEXT OF THE ATTAINMENT OF PEAK CAPACITY FOR A BODY SYSTEM, STARTING IN EARLY DEVELOPMENT WHEN PLASTICITY PERMITS CHANGES IN STRUCTURE AND FUNCTION INDUCED BY A RANGE OF ENVIRONMENTAL STIMULI, FOLLOWED BY A PERIOD OF DECLINE, THE RATE OF WHICH DEPENDS ON THE PEAK ATTAINED AS WELL AS THE LATER LIFE CONDITIONS. SUCH PATH DEPENDENCY IN THE RATE OF AGEING MAY OFFER NEW INSIGHTS INTO ITS MODIFICATION. FOCUSING ON MUSCULOSKELETAL AND CARDIOVASCULAR FUNCTION, WE DISCUSS THIS MODEL AND THE POSSIBLE UNDERLYING MECHANISMS, INCLUDING ENDOTHELIAL FUNCTION, OXIDATIVE STRESS, STEM CELLS AND NUTRITIONAL FACTORS SUCH AS VITAMIN D STATUS. EPIGENETIC CHANGES INDUCED DURING DEVELOPMENTAL PLASTICITY, AND IMMUNE FUNCTION MAY PROVIDE A COMMON MECHANISTIC PROCESS UNDERLYING A LIFE COURSE MODEL OF AGEING. THE LIFE COURSE TRAJECTORY DIFFERS IN HIGH AND LOW RESOURCE SETTINGS. NEW INSIGHTS INTO THE DEVELOPMENTAL COMPONENTS OF THE LIFE COURSE MODEL OF AGEING MAY LEAD TO THE DESIGN OF BIOMARKERS OF LATER CHRONIC DISEASE RISK AND TO NEW INTERVENTIONS TO PROMOTE HEALTHY AGEING, WITH IMPORTANT IMPLICATIONS FOR PUBLIC HEALTH. 2016 19 5164 40 PRECLINICAL AND CLINICAL EVIDENCE OF DNA METHYLATION CHANGES IN RESPONSE TO TRAUMA AND CHRONIC STRESS. EXPOSURE TO CHRONIC STRESS, EITHER REPEATED SEVERE ACUTE OR MODERATE SUSTAINED STRESS, IS ONE OF THE STRONGEST RISK FACTORS FOR THE DEVELOPMENT OF PSYCHOPATHOLOGIES SUCH AS POST-TRAUMATIC STRESS DISORDER AND DEPRESSION. CHRONIC STRESS IS LINKED WITH SEVERAL LASTING BIOLOGICAL CONSEQUENCES, PARTICULARLY TO THE STRESS ENDOCRINE SYSTEM BUT ALSO AFFECTING INTERMEDIATE PHENOTYPES SUCH AS BRAIN STRUCTURE AND FUNCTION, IMMUNE FUNCTION, AND BEHAVIOR. ALTHOUGH GENETIC PREDISPOSITION CONFERS A PROPORTION OF THE RISK, THE MOST RELEVANT MOLECULAR MECHANISMS DETERMINING THOSE SUSCEPTIBLE AND RESILIENT TO THE EFFECTS OF STRESS AND TRAUMA MAY BE EPIGENETIC. EPIGENETICS REFERS TO THE MECHANISMS THAT REGULATE GENOMIC INFORMATION BY DYNAMICALLY CHANGING THE PATTERNS OF TRANSCRIPTION AND TRANSLATION OF GENES. MOUNTING EVIDENCE FROM PRECLINICAL RODENT AND CLINICAL POPULATION STUDIES STRONGLY SUPPORT THAT EPIGENETIC MODIFICATIONS CAN OCCUR IN RESPONSE TO TRAUMATIC AND CHRONIC STRESS. HERE, WE DISCUSS THIS LITERATURE EXAMINING STRESS-INDUCED EPIGENETIC CHANGES IN PRECLINICAL MODELS AND CLINICAL COHORTS OF STRESS AND TRAUMA OCCURRING EARLY IN LIFE OR IN ADULTHOOD. WE HIGHLIGHT THAT A COMPLEX RELATIONSHIP BETWEEN THE TIMING OF ENVIRONMENTAL STRESSORS AND GENETIC PREDISPOSITIONS LIKELY MEDIATE THE RESPONSE TO CHRONIC STRESS OVER TIME, AND THAT A BETTER UNDERSTANDING OF EPIGENETIC CHANGES IS NEEDED BY FURTHER INVESTIGATIONS IN LONGITUDINAL AND POSTMORTEM BRAIN CLINICAL COHORTS. 2017 20 5069 28 PHYSICAL ACTIVITY IN THE PREVENTION OF HUMAN DISEASES: ROLE OF EPIGENETIC MODIFICATIONS. EPIGENETIC MODIFICATION REFERS TO HERITABLE CHANGES IN GENE FUNCTION THAT CANNOT BE EXPLAINED BY ALTERATIONS IN THE DNA SEQUENCE. THE CURRENT LITERATURE CLEARLY DEMONSTRATES THAT THE EPIGENETIC RESPONSE IS HIGHLY DYNAMIC AND INFLUENCED BY DIFFERENT BIOLOGICAL AND ENVIRONMENTAL FACTORS SUCH AS AGING, NUTRIENT AVAILABILITY AND PHYSICAL EXERCISE. AS SUCH, IT IS WELL ACCEPTED THAT PHYSICAL ACTIVITY AND EXERCISE CAN MODULATE GENE EXPRESSION THROUGH EPIGENETIC ALTERNATIONS ALTHOUGH THE TYPE AND DURATION OF EXERCISE ELICITING SPECIFIC EPIGENETIC EFFECTS THAT CAN RESULT IN HEALTH BENEFITS AND PREVENT CHRONIC DISEASES REMAINS TO BE DETERMINED. THIS REVIEW HIGHLIGHTS THE MOST SIGNIFICANT FINDINGS FROM EPIGENETIC STUDIES INVOLVING PHYSICAL ACTIVITY/EXERCISE INTERVENTIONS KNOWN TO BENEFIT CHRONIC DISEASES SUCH AS METABOLIC SYNDROME, DIABETES, CANCER, CARDIOVASCULAR AND NEURODEGENERATIVE DISEASES. 2017