1 4375 139 MISREGULATED INFLAMMATION AS AN OUTCOME OF EARLY-LIFE EXPOSURE TO ENDOCRINE-DISRUPTING CHEMICALS. THIS REVIEW INTRODUCES A POTENTIAL UNIFYING CONCEPT INVOLVING THE RISK OF CHRONIC DISEASES IN WHICH EARLY-LIFE EXPOSURE TO ENDOCRINE-DISRUPTING CHEMICALS (EDCS) CAN PROGRAM HOST RESPONSES FOR MISREGULATED INFLAMMATION. INFLAMMATION IS A PART OF HOST DEFENSE AGAINST PATHOGENIC CHALLENGES AND ONE OF THE PROCESSES NECESSARY FOR NORMAL TISSUE HOMEOREGULATION AND FOR REPRODUCTION (E.G., IMPLANTATION, LABOR). DEVIATIONS FROM TIGHTLY REGULATED INFLAMMATION PRESENT A SIGNIFICANT HEALTH RISK BECAUSE UNRESOLVED INFLAMMATION CAN COMPROMISE TISSUE FUNCTION AND INCREASE THE RISK FOR LATER-LIFE CANCER IN THE AFFECTED TARGET TISSUE. THE CRITICAL WINDOWS OF INNATE IMMUNE VULNERABILITY DURING PRENATAL AND NEONATAL MATURATION ARE WHEN DEVELOPMENTAL PROGRAMMING AND THE TRAJECTORY FOR CHILDHOOD AND ADULT INFLAMMATORY RESPONSES ARE LARGELY ESTABLISHED. MISREGULATED INFLAMMATION IS A COMMON THREAD THAT LINKS MOST SIGNIFICANT CHRONIC DISEASES AND CONDITIONS ACROSS ALL PHYSIOLOGIC SYSTEMS AS WELL AS THE ASSOCIATED COMORBID CONDITIONS. AS A RESULT, CHRONIC DISEASES EXIST BOTH AS A MYRIAD OF CONDITIONS AND AS AN INTEGRATED, DYSFUNCTIONALLY CONNECTED UNIT. BECAUSE THE HORMONE MICROENVIRONMENT EXERTS A SIGNIFICANT EFFECT ON RESIDENT INNATE IMMUNE CELL FUNCTION, ENDOCRINE DISRUPTION IS LIKELY TO PRODUCE MISREGULATED INFLAMMATION IN TISSUES. AMONG THE FACTORS DETERMINING SPECIFIC HEALTH RISKS AND DISEASE OUTCOMES ACROSS A LIFETIME ARE THE AGE OF EXPOSURE, SEX, GENETIC BACKGROUND, AND TRANSGENERATIONAL EPIGENETIC EXPERIENCES. ADDITIONAL RESEARCH INTO EARLY-LIFE EDC EXPOSURE AND MISREGULATION OF INFLAMMATION APPEARS TO BE A USEFUL AVENUE FOR REDUCING ENVIRONMENTAL HEALTH RISKS. 2012 2 3582 35 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 3 2007 33 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 4 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 5 4125 29 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 6 6844 25 [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 7 6034 39 THE CHALLENGE BY MULTIPLE ENVIRONMENTAL AND BIOLOGICAL FACTORS INDUCE INFLAMMATION IN AGING: THEIR ROLE IN THE PROMOTION OF CHRONIC DISEASE. THE AGING PROCESS IS DRIVEN BY MULTIPLE MECHANISMS THAT LEAD TO CHANGES IN ENERGY PRODUCTION, OXIDATIVE STRESS, HOMEOSTATIC DYSREGULATION AND EVENTUALLY TO LOSS OF FUNCTIONALITY AND INCREASED DISEASE SUSCEPTIBILITY. MOST AGED INDIVIDUALS DEVELOP CHRONIC LOW-GRADE INFLAMMATION, WHICH IS AN IMPORTANT RISK FACTOR FOR MORBIDITY, PHYSICAL AND COGNITIVE IMPAIRMENT, FRAILTY, AND DEATH. AT ANY AGE, CHRONIC INFLAMMATORY DISEASES ARE MAJOR CAUSES OF MORBIMORTALITY, AFFECTING UP TO 5-8% OF THE POPULATION OF INDUSTRIALIZED COUNTRIES. SEVERAL ENVIRONMENTAL FACTORS CAN PLAY AN IMPORTANT ROLE FOR MODIFYING THE INFLAMMATORY STATE. GENETICS ACCOUNTS FOR ONLY A SMALL FRACTION OF CHRONIC-INFLAMMATORY DISEASES, WHEREAS ENVIRONMENTAL FACTORS APPEAR TO PARTICIPATE, EITHER WITH A CAUSATIVE OR A PROMOTIONAL ROLE IN 50% TO 75% OF PATIENTS. SEVERAL OF THOSE CHANGES DEPEND ON EPIGENETIC CHANGES THAT WILL FURTHER MODIFY THE INDIVIDUAL RESPONSE TO ADDITIONAL STIMULI. THE INTERACTION BETWEEN INFLAMMATION AND THE ENVIRONMENT OFFERS IMPORTANT INSIGHTS ON AGING AND HEALTH. THESE CONDITIONS, OFTEN DEPENDING ON THE INDIVIDUAL'S SEX, APPEAR TO LEAD TO DECREASED LONGEVITY AND PHYSICAL AND COGNITIVE DECLINE. IN ADDITION TO BIOLOGICAL FACTORS, THE ENVIRONMENT IS ALSO INVOLVED IN THE GENERATION OF PSYCHOLOGICAL AND SOCIAL CONTEXT LEADING TO STRESS. POOR PSYCHOLOGICAL ENVIRONMENTS AND OTHER SOURCES OF STRESS ALSO RESULT IN INCREASED INFLAMMATION. HOWEVER, THE MECHANISMS UNDERLYING THE ROLE OF ENVIRONMENTAL AND PSYCHOSOCIAL FACTORS AND NUTRITION ON THE REGULATION OF INFLAMMATION, AND HOW THE RESPONSE ELICITED FOR THOSE FACTORS INTERACT AMONG THEM, ARE POORLY UNDERSTOOD. WHEREAS CERTAIN DELETERIOUS ENVIRONMENTAL FACTORS RESULT IN THE GENERATION OF OXIDATIVE STRESS DRIVEN BY AN INCREASED PRODUCTION OF REACTIVE OXYGEN AND NITROGEN SPECIES, ENDOPLASMIC RETICULUM STRESS, AND INFLAMMATION, OTHER FACTORS, INCLUDING NUTRITION (POLYUNSATURATED FATTY ACIDS) AND BEHAVIORAL FACTORS (EXERCISE) CONFER PROTECTION AGAINST INFLAMMATION, OXIDATIVE AND ENDOPLASMIC RETICULUM STRESS, AND THUS AMELIORATE THEIR DELETERIOUS EFFECT. HERE, WE DISCUSS PROCESSES AND MECHANISMS OF INFLAMMATION ASSOCIATED WITH ENVIRONMENTAL FACTORS AND BEHAVIOR, THEIR LINKS TO SEX AND GENDER, AND THEIR OVERALL IMPACT ON AGING. 2020 8 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 9 1938 35 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 10 5202 34 PRENATAL ORIGINS OF ADULT DISEASE. PURPOSE OF REVIEW: HUMAN EPIDEMIOLOGICAL AND ANIMAL STUDIES SHOW THAT MANY CHRONIC ADULT CONDITIONS HAVE THEIR ANTECEDENTS IN COMPROMISED FETAL AND EARLY POSTNATAL DEVELOPMENT. DEVELOPMENTAL PROGRAMMING IS DEFINED AS THE RESPONSE BY THE DEVELOPING MAMMALIAN ORGANISM TO A SPECIFIC CHALLENGE DURING A CRITICAL TIME WINDOW THAT ALTERS THE TRAJECTORY OF DEVELOPMENT WITH RESULTING PERSISTENT EFFECTS ON PHENOTYPE. MAMMALS PASS MORE BIOLOGICAL MILESTONES BEFORE BIRTH THAN ANY OTHER TIME IN THEIR LIVES. EACH INDIVIDUAL'S PHENOTYPE IS INFLUENCED BY THE DEVELOPMENTAL ENVIRONMENT AS MUCH AS THEIR GENES. A BETTER UNDERSTANDING IS REQUIRED OF GENE-ENVIRONMENT INTERACTIONS LEADING TO ADULT DISEASE. RECENT FINDINGS: DURING DEVELOPMENT, THERE ARE CRITICAL PERIODS OF VULNERABILITY TO SUBOPTIMAL CONDITIONS WHEN PROGRAMMING MAY PERMANENTLY MODIFY DISEASE SUSCEPTIBILITY. PROGRAMMING INVOLVES STRUCTURAL CHANGES IN IMPORTANT ORGANS; ALTERED CELL NUMBER, IMBALANCE IN DISTRIBUTION OF DIFFERENT CELL TYPES WITHIN THE ORGAN, AND ALTERED BLOOD SUPPLY OR RECEPTOR NUMBERS. COMPENSATORY EFFORTS BY THE FETUS MAY CARRY A PRICE. EFFECTS OF PROGRAMMING MAY PASS ACROSS GENERATIONS BY MECHANISMS THAT DO NOT NECESSARILY INVOLVE STRUCTURAL GENE CHANGES. PROGRAMMING OFTEN HAS DIFFERENT EFFECTS IN MALES AND FEMALES. SUMMARY: DEVELOPMENTAL PROGRAMMING SHOWS THAT EPIGENETIC FACTORS PLAY MAJOR ROLES IN DEVELOPMENT OF PHENOTYPE AND PREDISPOSITION TO DISEASE IN LATER LIFE. 2008 11 1360 36 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 12 2103 30 EPIGENETIC EPIDEMIOLOGY OF THE DEVELOPMENTAL ORIGINS HYPOTHESIS. EXTENSIVE HUMAN EPIDEMIOLOGIC AND ANIMAL MODEL DATA INDICATE THAT DURING CRITICAL PERIODS OF PRENATAL AND POSTNATAL MAMMALIAN DEVELOPMENT, NUTRITION AND OTHER ENVIRONMENTAL STIMULI INFLUENCE DEVELOPMENTAL PATHWAYS AND THEREBY INDUCE PERMANENT CHANGES IN METABOLISM AND CHRONIC DISEASE SUSCEPTIBILITY. THE BIOLOGIC MECHANISMS UNDERLYING THIS "DEVELOPMENTAL ORIGINS HYPOTHESIS" ARE POORLY UNDERSTOOD. THIS REVIEW FOCUSES ON THE LIKELY INVOLVEMENT OF EPIGENETIC MECHANISMS IN THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE (DOHAD). WE DESCRIBE PERMANENT EFFECTS OF TRANSIENT ENVIRONMENTAL INFLUENCES ON THE DEVELOPMENTAL ESTABLISHMENT OF EPIGENETIC GENE REGULATION AND EVIDENCE LINKING EPIGENETIC DYSREGULATION WITH HUMAN DISEASE. WE PROPOSE A DEFINITION OF "EPIGENETIC EPIDEMIOLOGY" AND DELINEATE HOW THIS EMERGING FIELD PROVIDES A BASIS FROM WHICH TO EXPLORE THE ROLE OF EPIGENETIC MECHANISMS IN DOHAD. WE SUGGEST STRATEGIES FOR FUTURE HUMAN EPIDEMIOLOGIC STUDIES TO IDENTIFY CAUSAL ASSOCIATIONS BETWEEN EARLY EXPOSURES, LONG-TERM CHANGES IN EPIGENETIC REGULATION, AND DISEASE, WHICH MAY ULTIMATELY ENABLE SPECIFIC EARLY-LIFE INTERVENTIONS TO IMPROVE HUMAN HEALTH. 2007 13 2274 27 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 14 3771 37 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 15 6251 37 THE MICROBIOLOGICAL MEMORY, AN EPIGENETIC REGULATOR GOVERNING THE BALANCE BETWEEN GOOD HEALTH AND METABOLIC DISORDERS. IF THE TRANSMISSION OF BIOLOGICAL INFORMATION FROM ONE GENERATION TO THE NEXT IS BASED ON DNA, MOST HERITABLE PHENOTYPIC TRAITS SUCH AS CHRONIC METABOLIC DISEASES, ARE NOT LINKED TO GENETIC VARIATION IN DNA SEQUENCES. NON-GENETIC HERITABILITY MIGHT HAVE SEVERAL CAUSES INCLUDING EPIGENETIC, PARENTAL EFFECT, ADAPTIVE SOCIAL LEARNING, AND INFLUENCE OF THE ECOLOGICAL ENVIRONMENT. DISTINGUISHING AMONG THESE CAUSES IS CRUCIAL TO RESOLVE MAJOR PHENOTYPIC ENIGMAS. STRONG EVIDENCE INDICATES THAT CHANGES IN DNA EXPRESSION THROUGH VARIOUS EPIGENETIC MECHANISMS CAN BE LINKED TO PARENT-OFFSPRING RESEMBLANCE IN TERMS OF SENSITIVITY TO METABOLIC DISEASES. AMONG NON-GENETIC HERITABLE TRAITS, EARLY NUTRITION COULD ACCOUNT FOR A LONG TERM DEVIANT PROGRAMMING OF GENES EXPRESSION RESPONSIBLE FOR METABOLIC DISEASES IN ADULTHOOD. NUTRITION COULD SHAPE AN INADEQUATE GUT MICROBIOTA (DYSBIOSIS), TRIGGERING EPIGENETIC DEREGULATION OF TRANSCRIPTION WHICH CAN BE OBSERVED IN CHRONIC METABOLIC DISEASES. WE REVIEW HEREIN THE EVIDENCE THAT DYSBIOSIS MIGHT BE A MAJOR CAUSE OF HERITABLE EPIGENETIC PATTERNS FOUND TO BE ASSOCIATED WITH METABOLIC DISEASES. BY TAKING INTO ACCOUNT THE RECENT ADVANCES ON THE GUT MICROBIOME, WE HAVE AGGREGATED TOGETHER DIFFERENT OBSERVATIONS SUPPORTING THE HYPOTHESIS THAT THE GUT MICROBIOTA COULD PROMOTE THE MOLECULAR CROSSTALK BETWEEN BACTERIA AND SURROUNDING HOST CELLS WHICH CONTROLS THE PATHOLOGICAL EPIGENETIC SIGNATURE. WE INTRODUCE FOR THE FIRST TIME THE CONCEPT OF "MICROBIOLOGICAL MEMORY" AS THE MAIN REGULATOR OF THE EPIGENETIC SIGNATURES, THEREBY INDICATING THAT DIFFERENT CAUSES OF NON-GENETIC HERITABILITY CAN INTERACT IN COMPLEX PATHWAYS TO PRODUCE INHERITANCE. 2018 16 6823 33 [GENERAL CONCEPTS OF EPIGENETICS: PROJECTIONS IN PAEDIATRICS]. CURRENT EVIDENCE SUPPORTS THE NOTION THAT ALTERATIONS IN INTRAUTERINE GROWTH AND DURING THE FIRST YEARS OF LIFE HAVE A SUBSTANTIAL EFFECT ON THE RISK FOR THE DEVELOPMENT OF CHRONIC DISEASE, WHICH IN SOME CASES IS EVEN HIGHER THAN THOSE DUE TO GENETIC FACTORS. THE PERSISTENCE AND REPRODUCIBILITY OF THE PHENOTYPES ASSOCIATED WITH ALTERED EARLY DEVELOPMENT SUGGEST THE PARTICIPATION OF MECHANISMS THAT WOULD RECORD ENVIRONMENTAL CUES, GENERATING A CELLULAR REPROGRAMMING (I.E., EPIGENETIC MECHANISMS). THIS REVIEW IS AN INTRODUCTION TO A SERIES OF FIVE ARTICLES FOCUSED ON THE PARTICIPATION OF EPIGENETIC MECHANISMS IN THE DEVELOPMENT OF HIGHLY PREVALENT CHRONIC DISEASES (I.E., CARDIOVASCULAR, METABOLIC, ASTHMA/ALLERGIES AND CANCER) AND THEIR ORIGINS IN THE FOETAL AND NEONATAL PERIOD. THIS SERIES OF ARTICLES AIMS TO SHOW THE STATE OF THE ART IN THIS RESEARCH AREA AND PRESENT THE UPCOMING CLUES AND CHALLENGES, IN WHICH PAEDIATRICIANS HAVE A PROMINENT ROLE, DEVELOPING STRATEGIES FOR THE PREVENTION, EARLY DETECTION AND FOLLOW-UP. 2016 17 5164 31 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 18 6812 25 [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 19 4273 32 MICROBIOTA AND EPIGENETICS: HEALTH IMPACT. EPIGENETIC CHANGES ASSOCIATED WITH DISEASE DEVELOPMENT AND PROGRESSIONS ARE OF INCREASING IMPORTANCE BECAUSE OF THEIR POTENTIAL DIAGNOSTIC AND THERAPEUTIC APPLICATIONS. SEVERAL EPIGENETIC CHANGES ASSOCIATED WITH CHRONIC METABOLIC DISORDERS HAVE BEEN STUDIED IN VARIOUS DISEASES. EPIGENETIC CHANGES ARE MOSTLY MODULATED BY ENVIRONMENTAL FACTORS, INCLUDING THE HUMAN MICROBIOTA LIVING IN DIFFERENT PARTS OF OUR BODIES. THE MICROBIAL STRUCTURAL COMPONENTS AND THE MICROBIALLY DERIVED METABOLITES DIRECTLY INTERACT WITH HOST CELLS, THEREBY MAINTAINING HOMEOSTASIS. MICROBIOME DYSBIOSIS, ON THE OTHER HAND, IS KNOWN TO PRODUCE ELEVATED LEVELS OF DISEASE-LINKED METABOLITES, WHICH MAY DIRECTLY AFFECT A HOST METABOLIC PATHWAY OR INDUCE EPIGENETIC CHANGES THAT CAN LEAD TO DISEASE DEVELOPMENT. DESPITE THEIR IMPORTANT ROLE IN HOST PHYSIOLOGY AND SIGNAL TRANSDUCTION, THERE HAS BEEN LITTLE RESEARCH INTO THE MECHANICS AND PATHWAYS ASSOCIATED WITH EPIGENETIC MODIFICATIONS. THIS CHAPTER FOCUSES ON THE RELATIONSHIP BETWEEN MICROBES AND THEIR EPIGENETIC EFFECTS IN DISEASED PATHOLOGY, AS WELL AS ON THE REGULATION AND METABOLISM OF THE DIETARY OPTIONS AVAILABLE TO THE MICROBES. FURTHERMORE, THIS CHAPTER ALSO PROVIDES A PROSPECTIVE LINK BETWEEN THESE TWO IMPORTANT PHENOMENA, TERMED "MICROBIOME AND EPIGENETICS." 2023 20 4126 27 MECHANISMS OF DISEASE: THE DEVELOPMENTAL ORIGINS OF DISEASE AND THE ROLE OF THE EPIGENOTYPE. THERE IS ACCUMULATING EVIDENCE THAT MANY CHRONIC DISEASES SUCH AS TYPE 2 DIABETES AND CORONARY HEART DISEASE MIGHT ORIGINATE DURING EARLY LIFE. THIS EVIDENCE GIVES RISE TO THE DEVELOPMENTAL ORIGINS OF DISEASE HYPOTHESIS, AND IS SUPPORTED BY EPIDEMIOLOGICAL DATA IN HUMANS AND EXPERIMENTAL ANIMAL MODELS. A PERTURBED ENVIRONMENT IN EARLY LIFE IS THOUGHT TO ELICIT A RANGE OF PHYSIOLOGICAL AND CELLULAR ADAPTIVE RESPONSES IN KEY ORGAN SYSTEMS. THESE ADAPTIVE CHANGES RESULT IN PERMANENT ALTERATIONS AND MIGHT LEAD TO PATHOLOGY IN LATER LIFE. AGING ORGANS AND CELLS SEEM THEREFORE TO RETAIN A 'MEMORY' OF THEIR FETAL HISTORY AND ADAPTIVE RESPONSES. THE MECHANISMS UNDERLYING THE DEVELOPMENTAL ORIGINS OF DISEASE REMAIN POORLY DEFINED. EPIGENETIC TAGGING OF GENES, SUCH AS DNA METHYLATION AND HISTONE MODIFICATION, CONTROLS THE FUNCTION OF THE GENOME AT DIFFERENT LEVELS AND MAINTAINS CELLULAR MEMORY AFTER MANY CELLULAR DIVISIONS; IMPORTANTLY, TAGGING CAN BE MODULATED BY THE ENVIRONMENT AND IS INVOLVED IN ONSET OF DISEASES SUCH AS CANCER. HERE WE REVIEW THE EVIDENCE FOR THE DEVELOPMENTAL ORIGINS OF DISEASE AND DISCUSS THE ROLE OF THE EPIGENOTYPE AS A CONTRIBUTING MECHANISM. ENVIRONMENTALLY INDUCED CHANGES IN THE EPIGENOTYPE MIGHT BE KEY PRIMARY EVENTS IN THE DEVELOPMENTAL ORIGINS OF DISEASE, WITH IMPORTANT CLINICAL IMPLICATIONS. 2007