1 1361 140 DEVELOPMENTAL CONSEQUENCES OF TRACE MINERAL DEFICIENCIES IN RODENTS: ACUTE AND LONG-TERM EFFECTS. APPROXIMATELY 3% OF INFANTS BORN HAVE AT LEAST ONE SERIOUS CONGENITAL MALFORMATION. IN THE U.S., AN AVERAGE OF 10 INFANTS PER THOUSAND DIE BEFORE 1 Y OF LIFE; ABOUT HALF OF THESE DEATHS CAN BE ATTRIBUTED TO BIRTH DEFECTS, LOW BIRTH WEIGHT OR PREMATURITY. ALTHOUGH THE CAUSES OF DEVELOPMENTAL ABNORMALITIES ARE CLEARLY MULTIFACTORIAL IN NATURE, WE SUGGEST THAT A COMMON FACTOR CONTRIBUTING TO THE OCCURRENCE OF DEVELOPMENTAL ABNORMALITIES IS SUBOPTIMAL MINERAL NUTRITION DURING EMBRYONIC AND FETAL DEVELOPMENT. USING ZINC AND COPPER AS EXAMPLES, EVIDENCE IS PRESENTED THAT NUTRITIONAL DEFICIENCIES CAN RAPIDLY AFFECT THE DEVELOPING CONCEPTUS AND RESULT IN GROSS STRUCTURAL ABNORMALITIES. DEFICITS OF ZINC OR COPPER CAN RESULT IN RAPID CHANGES IN CELLULAR REDOX BALANCE, TISSUE OXIDATIVE STRESS, INAPPROPRIATE PATTERNS OF CELL DEATH, ALTERATIONS IN THE MIGRATION OF NEURAL CREST CELLS AND CHANGES IN THE EXPRESSION OF KEY PATTERNING GENES. IN ADDITION TO WELL-RECOGNIZED MALFORMATIONS, MINERAL DEFICIENCIES DURING PERINATAL DEVELOPMENT CAN RESULT IN BEHAVIORAL, IMMUNOLOGICAL AND BIOCHEMICAL ABNORMALITIES THAT PERSIST INTO ADULTHOOD. ALTHOUGH THESE PERSISTENT DEFECTS CAN IN PART BE ATTRIBUTED TO SUBTLE MORPHOLOGICAL ABNORMALITIES, IN OTHER CASES THEY MAY BE SECONDARY TO EPIGENETIC OR DEVELOPMENTAL CHANGES IN DNA METHYLATION PATTERNS. EPIGENETIC DEFECTS COMBINED WITH SUBTLE MORPHOLOGICAL ABNORMALITIES CAN INFLUENCE AN INDIVIDUAL'S RISK FOR CERTAIN CHRONIC DISEASES AND THUS INFLUENCE HIS OR HER RISK FOR MORBIDITY AND MORTALITY LATER IN LIFE. 2003 2 3582 25 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 1371 33 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 4 4125 31 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 5 2274 32 EPIGENETIC REGULATION AND FETAL PROGRAMMING. FETAL PROGRAMMING ENCOMPASSES THE ROLE OF DEVELOPMENTAL PLASTICITY IN RESPONSE TO ENVIRONMENTAL AND NUTRITIONAL SIGNALS DURING EARLY LIFE AND ITS POTENTIAL ADVERSE CONSEQUENCES (RISK OF CARDIOVASCULAR, METABOLIC AND BEHAVIOURAL DISEASES) IN LATER LIFE. THE FIRST STUDIES IN THIS FIELD HIGHLIGHTED AN ASSOCIATION BETWEEN POOR FETAL GROWTH AND CHRONIC ADULT DISEASES. HOWEVER, ENVIRONMENTAL SIGNALS DURING EARLY LIFE MAY LEAD TO ADVERSE LONG-TERM EFFECTS INDEPENDENTLY OF OBVIOUS EFFECTS ON FETAL GROWTH. ADVERSE LONG-TERM EFFECTS REFLECT A MISMATCH BETWEEN EARLY (FETAL AND NEONATAL) ENVIRONMENTAL CONDITIONS AND THE CONDITIONS THAT THE INDIVIDUAL WILL CONFRONT LATER IN LIFE. THE MECHANISMS UNDERLYING THIS RISK REMAIN UNCLEAR. HOWEVER, EXPERIMENTAL DATA IN RODENTS AND RECENT OBSERVATIONS IN HUMANS SUGGEST THAT EPIGENETIC CHANGES IN REGULATORY GENES AND GROWTH-RELATED GENES PLAY A SIGNIFICANT ROLE IN FETAL PROGRAMMING. IMPROVEMENTS IN OUR UNDERSTANDING OF THE BIOCHEMICAL AND MOLECULAR MECHANISMS AT PLAY IN FETAL PROGRAMMING WOULD MAKE IT POSSIBLE TO IDENTIFY BIOMARKERS FOR DETECTING INFANTS AT HIGH RISK OF ADULT-ONSET DISEASES. SUCH IMPROVEMENTS SHOULD ALSO LEAD TO THE DEVELOPMENT OF PREVENTIVE AND THERAPEUTIC STRATEGIES. 2008 6 4496 33 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 7 3848 28 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 6088 41 THE EFFECTS OF ASSISTED REPRODUCTION TECHNOLOGIES ON METABOLIC HEALTH AND DISEASEDAGGER. THE INCREASING PREVALENCE OF METABOLIC DISEASES PLACES A SUBSTANTIAL BURDEN ON HUMAN HEALTH THROUGHOUT THE WORLD. IT IS BELIEVED THAT PREDISPOSITION TO METABOLIC DISEASE STARTS EARLY IN LIFE, A PERIOD OF GREAT SUSCEPTIBILITY TO EPIGENETIC REPROGRAMMING DUE TO ENVIRONMENTAL INSULTS. ASSISTED REPRODUCTIVE TECHNOLOGIES (ART), I.E., TREATMENTS FOR INFERTILITY, MAY AFFECT EMBRYO DEVELOPMENT, RESULTING IN MULTIPLE ADVERSE HEALTH OUTCOMES IN POSTNATAL LIFE. THE MOST FREQUENTLY OBSERVED ALTERATION IN ART PREGNANCIES IS IMPAIRED PLACENTAL NUTRIENT TRANSFER. MOREOVER, CONSEQUENT INTRAUTERINE GROWTH RESTRICTION AND LOW BIRTH WEIGHT FOLLOWED BY CATCH-UP GROWTH CAN ALL PREDICT FUTURE OBESITY, INSULIN RESISTANCE, AND CHRONIC METABOLIC DISEASES. IN THIS REVIEW, WE HAVE FOCUSED ON EVIDENCE OF ADVERSE METABOLIC ALTERATIONS ASSOCIATED WITH ART, WHICH CAN CONTRIBUTE TO THE DEVELOPMENT OF CHRONIC ADULT-ONSET DISEASES, SUCH AS METABOLIC SYNDROME, TYPE 2 DIABETES, AND CARDIOVASCULAR DISEASE. DUE TO HIGH PHENOTYPIC PLASTICITY, ART PREGNANCIES CAN PRODUCE BOTH OFFSPRING WITH ADVERSE HEALTH OUTCOMES, AS WELL AS HEALTHY INDIVIDUALS. WE FURTHER DISCUSS THE SEX-SPECIFIC AND AGE-DEPENDENT METABOLIC ALTERATIONS REFLECTED IN ART OFFSPRING, AND HOW THE DEGREE OF INTERFERENCE OF A GIVEN ART PROCEDURE (FROM MILD TO MORE SEVERE MANIPULATION OF THE EGG) AFFECTS THE OCCURRENCE AND DEGREE OF OFFSPRING ALTERATIONS. OVER THE LAST FEW YEARS, STUDIES HAVE REPORTED SIGNS OF CARDIOMETABOLIC ALTERATIONS IN ART OFFSPRING THAT ARE DETECTABLE AT A YOUNG AGE BUT THAT DO NOT APPEAR TO CONSTITUTE A HIGH RISK OF DISEASE AND MORBIDITY PER SE. THESE ABNORMAL PHENOTYPES COULD BE EARLY INDICATORS OF THE DEVELOPMENT OF CHRONIC DISEASES, INCLUDING METABOLIC SYNDROME, IN ADULTHOOD. THE EARLY DETECTION OF METABOLIC ALTERATIONS COULD CONTRIBUTE TO PREVENTING THE ONSET OF DISEASE IN ADULTHOOD. SUCH EARLY INTERVENTIONS MAY COUNTERACT THE RISK FACTORS AND IMPROVE THE LONG-TERM HEALTH OF THE INDIVIDUAL. 2021 9 6844 36 [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 10 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 11 6064 29 THE DEVELOPMENTAL ORIGINS OF ADULT DISEASE. EPIDEMIOLOGICAL AND CLINICAL OBSERVATIONS HAVE LED TO THE HYPOTHESIS THAT THE RISK OF DEVELOPING SOME CHRONIC DISEASES IN ADULTHOOD IS INFLUENCED NOT ONLY BY GENETIC AND ADULT LIFESTYLE FACTORS, BUT ALSO BY ENVIRONMENTAL FACTORS ACTING IN EARLY LIFE. THESE FACTORS ACT THROUGH THE PROCESSES OF DEVELOPMENTAL PLASTICITY AND POSSIBLY EPIGENETIC MODIFICATION, AND CAN BE DISTINGUISHED FROM DEVELOPMENTAL DISRUPTION. THE CONCEPT OF PREDICTIVE ADAPTATION HAS BEEN DEVELOPED TO EXPLAIN THE RELATIONSHIP BETWEEN EARLY LIFE EVENTS AND THE RISK OF LATER DISEASE. AT ITS BASE, THE MODEL SUGGESTS THAT A MISMATCH BETWEEN FETAL EXPECTATION OF ITS POSTNATAL ENVIRONMENT AND ACTUAL POSTNATAL ENVIRONMENT CONTRIBUTE TO LATER ADULT DISEASE RISK. THIS MISMATCH IS EXACERBATED, IN PART, BY THE PHENOMENON OF "MATERNAL CONSTRAINT" ON FETAL GROWTH, WHICH IMPLICITLY PROVIDES AN UPPER LIMIT OF POSTNATAL NUTRITIONAL ENVIRONMENT THAT HUMANS HAVE ADAPTED FOR AND IS NOW FREQUENTLY EXCEEDED. THESE EXPERIMENTAL, CLINICAL AND CONCEPTUAL CONSIDERATIONS HAVE IMPORTANT IMPLICATIONS FOR PREVENTION AND INTERVENTION IN THE CURRENT EPIDEMIC OF CHILDHOOD OBESITY AND ADULT METABOLIC AND CARDIOVASCULAR DISORDERS. 2005 12 6234 30 THE LONG-TERM EFFECTS OF PRENATAL DEVELOPMENT ON GROWTH AND METABOLISM. PEOPLE WHO WERE SMALL AT BIRTH AND HAD POOR INFANT GROWTH HAVE AN INCREASED RISK OF ADULT CARDIOVASCULAR DISEASE, OSTEOPOROSIS, AND TYPE 2 DIABETES, PARTICULARLY IF THEIR RESTRICTED EARLY GROWTH WAS FOLLOWED BY INCREASED CHILDHOOD WEIGHT GAIN. THESE RELATIONS EXTEND ACROSS THE NORMAL RANGE OF BIRTH SIZE IN A GRADED MANNER, SO REDUCED SIZE IS NOT A PREREQUISITE. IN ADDITION, LARGER BIRTH SIZE IS ASSOCIATED WITH RISKS OF OBESITY AND TYPE 2 DIABETES. THE ASSOCIATIONS APPEAR TO REFLECT DEVELOPMENTAL PLASTIC RESPONSES MADE BY THE FETUS AND INFANT BASED ON CUES ABOUT THE ENVIRONMENT, INFLUENCED BY MATERNAL CHARACTERISTICS INCLUDING DIET, BODY COMPOSITION, STRESS, AND EXERCISE LEVELS. THESE RESPONSES INVOLVE EPIGENETIC PROCESSES THAT MODIFY THE OFFSPRING'S PHENOTYPE. VULNERABILITY TO ILL HEALTH RESULTS IF THE ENVIRONMENT IN INFANCY, CHILDHOOD, AND LATER LIFE IS MISMATCHED TO THE PHENOTYPE INDUCED IN DEVELOPMENT, INFORMED BY THE DEVELOPMENTAL CUES. THIS MISMATCH MAY ARISE THROUGH UNBALANCED DIET OR BODY COMPOSITION OF THE MOTHER OR A CHANGE IN LIFESTYLE FACTORS BETWEEN GENERATIONS. THESE INSIGHTS OFFER NEW POSSIBILITIES FOR THE EARLY DIAGNOSIS AND PREVENTION OF CHRONIC DISEASE. 2011 13 5202 33 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 14 6133 31 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 15 5647 47 SEX DIFFERENCES IN FETAL KIDNEY REPROGRAMMING: THE CASE IN THE RENIN-ANGIOTENSIN SYSTEM. DURING THE EARLY STAGES OF THE DEVELOPMENT OF THE LIVING MULTIORGAN SYSTEMS, GENOME MODIFICATIONS OTHER THAN SEQUENCE VARIATION OCCUR THAT GUIDE CELL DIFFERENTIATION AND ORGANOGENESIS. THESE MODIFICATIONS ARE KNOWN TO OPERATE AS A FETAL PROGRAMMING CODE DURING THIS PERIOD, AND RECENT RESEARCH INDICATES THAT THERE ARE SOME TISSUE-SPECIFIC CODES IN ORGANOGENESIS WHOSE EFFECTS MAY PERSIST AFTER BIRTH UNTIL ADULTHOOD. CONSEQUENTLY, THE EVENTS THAT DISRUPT THE PRE-ESTABLISHED EPIGENETIC PATTERN COULD INDUCE SHIFTS IN ORGAN PHYSIOLOGY, WITH IMPLICATIONS ON HEALTH FROM BIRTH OR LATER IN ADULT LIFE. CHRONIC KIDNEY DISEASE (CKD) IS ONE OF THE MAIN CAUSES OF MORTALITY WORLDWIDE; ITS ETIOLOGY IS MULTIFACTORIAL, BUT DIABETES, OBESITY, AND HYPERTENSION ARE THE MAIN CAUSES OF CKD IN ADULTS, ALTHOUGH THERE ARE OTHER RISK FACTORS THAT ARE MAINLY ASSOCIATED WITH AN INDIVIDUAL'S LIFESTYLE. RECENT STUDIES SUGGEST THAT FETAL REPROGRAMMING IN THE DEVELOPING KIDNEY COULD BE IMPLICATED IN THE SUSCEPTIBILITY TO KIDNEY DISEASE IN BOTH CHILDHOOD AND ADULTHOOD. SOME EPIGENETIC MODIFICATIONS, SUCH AS GENOME METHYLATION STATUS, DYSREGULATION OF MIRNA, AND HISTONE CODING ALTERATIONS IN GENES RELATED TO THE REGULATION OF THE RENIN-ANGIOTENSIN AXIS, A COMMON DENOMINATOR IN CKD, MAY HAVE ORIGINATED DURING FETAL DEVELOPMENT. THIS REVIEW FOCUSES ON EPIGENETIC CHANGES DURING NEPHROGENESIS AND THEIR REPERCUSSIONS ON KIDNEY HEALTH AND DISEASE. IN ADDITION, THE FOCUS IS ON THE INFLUENCE OF ENVIRONMENTAL FACTORS DURING PREGNANCY, SUCH AS MATERNAL METABOLIC DISEASES AND DIETARY AND METABOLIC CONDITIONS, AS WELL AS SOME SEX DIFFERENCES IN FETAL KIDNEY REPROGRAMMING DURING WHICH DYSREGULATION OF THE RENIN-ANGIOTENSIN SYSTEM IS INVOLVED. 2023 16 625 31 BIOLOGICAL AGE AND ENVIRONMENTAL RISK FACTORS FOR DEMENTIA AND STROKE: MOLECULAR MECHANISMS. SINCE THE DEVELOPMENT OF ANTIBIOTICS AND VACCINATION, AS WELL AS MAJOR IMPROVEMENTS IN PUBLIC HYGIENE, THE MAIN RISK FACTORS FOR MORBIDITY AND MORTALITY ARE AGE AND CHRONIC EXPOSURE TO ENVIRONMENTAL FACTORS, BOTH OF WHICH CAN INTERACT WITH GENETIC PREDISPOSITIONS. AS THE AVERAGE AGE OF THE POPULATION INCREASES, THE PREVALENCE AND COSTS OF CHRONIC DISEASES, ESPECIALLY NEUROLOGICAL CONDITIONS, ARE RAPIDLY INCREASING. THE DELETERIOUS EFFECTS OF AGE AND ENVIRONMENTAL RISK FACTORS, DEVELOP CHRONICALLY OVER RELATIVELY LONG PERIODS OF TIME, IN CONTRAST TO THE RELATIVELY RAPID DELETERIOUS EFFECTS OF INFECTIOUS DISEASES OR ACCIDENTS. OF PARTICULAR INTEREST IS THE HYPOTHESIS THAT THE DELETERIOUS EFFECTS OF ENVIRONMENTAL FACTORS MAY BE MEDIATED BY ACCELERATION OF BIOLOGICAL AGE. THIS HYPOTHESIS IS SUPPORTED BY EVIDENCE THAT DIETARY RESTRICTION, WHICH UNIVERSALLY DELAYS AGE-RELATED DISEASES, ALSO AMELIORATES DELETERIOUS EFFECTS OF ENVIRONMENTAL FACTORS. CONVERSELY, BOTH AGE AND ENVIRONMENTAL RISK FACTORS ARE ASSOCIATED WITH THE ACCUMULATION OF SOMATIC MUTATIONS IN MITOTIC CELLS AND EPIGENETIC MODIFICATIONS THAT ARE A MEASURE OF "BIOLOGICAL AGE", A BETTER PREDICTOR OF AGE-RELATED MORBIDITY AND MORTALITY THAN CHRONOLOGICAL AGE. HERE WE REVIEW EVIDENCE THAT ENVIRONMENTAL RISK FACTORS SUCH AS SMOKING AND AIR POLLUTION MAY ALSO DRIVE NEUROLOGICAL CONDITIONS, INCLUDING ALZHEIMER'S DISEASE, BY THE ACCELERATION OF BIOLOGICAL AGE, MEDIATED BY CUMULATIVE AND PERSISTENT EPIGENETIC EFFECTS AS WELL AS SOMATIC MUTATIONS. ELUCIDATION OF SUCH MECHANISMS COULD PLAUSIBLY ALLOW THE DEVELOPMENT OF INTERVENTIONS WHICH DELAY DELETERIOUS EFFECTS OF BOTH AGING AND ENVIRONMENTAL RISK FACTORS. 2022 17 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 18 6306 34 THE RECOGNITION AND TREATMENT OF GROWTH DISORDERS - A 50-YEAR RETROSPECTIVE. THE PAST 50 YEARS HAVE SEEN GREAT PROGRESS IN THE UNDERSTANDING AND TREATMENT OF CLASSIC GROWTH DISORDERS. ADVANCES SUCH AS THE RECOGNITION OF HORMONE RECEPTOR DEFECTS, THE DEVELOPMENT OF RECOMBINANT GROWTH HORMONE, AND THE EXPANDING AWARENESS OF EPIGENETIC PHENOMENA AFFECTING GROWTH ARE AMONG THESE GREAT ACHIEVEMENTS. YET GROWTH FAILURE REMAINS A PERVASIVE PROBLEM AMONG CHILDREN WITH COMPLEX HEALTH CONDITIONS, SUCH AS SURVIVORS OF CHILDHOOD CANCERS, PREMATURE INFANTS, ORGAN TRANSPLANT RECIPIENTS, AND CHILDREN WITH CYSTIC FIBROSIS. THE SIGNIFICANT INCREASES IN LIFE EXPECTANCY AMONG THESE GROUPS UNDERSCORES THE POTENTIAL CONSEQUENCES OF POOR GROWTH, WHETHER DUE TO THE UNDERLYING CONDITIONS OR MEDICAL TREATMENTS, AS THEY MAY HAVE LONG-LASTING EFFECTS INTO ADULTHOOD. THE ONGOING CONTRIBUTIONS OF HUMAN BIOLOGISTS TO THE STUDY OF HUMAN GROWTH REMAIN ESSENTIAL IN THE RECOGNITION AND TREATMENT OF GROWTH DISORDERS, BY DEFINING NORMAL PATTERNS OF GROWTH AND BODY COMPOSITION, THE INTERPLAY OF GROWTH AND MATURATION, THE ROLE OF ENVIRONMENTAL, BEHAVIORAL AND GENETIC FACTORS, AND THE LONG-TERM CONSEQUENCES OF GROWTH PATTERNS. EXAMPLES WILL BE GIVEN BASED ON TWO COMMON GENETIC DISORDERS, CYSTIC FIBROSIS AND SICKLE-CELL ANEMIA, TO HIGHLIGHT THE RELATIONSHIPS BETWEEN GROWTH FAILURE, SURVIVAL, AND MALNUTRITION. ALSO, A STUDY OF BONE MINERAL ACCRETION IN CHILDREN WITH CYSTIC FIBROSIS WILL ILLUSTRATE THE IMPORTANCE OF UNDERSTANDING PATTERNS OF GROWTH IN HEALTHY CHILDREN, AND THEIR APPLICATION IN THE DIAGNOSIS AND MANAGEMENT OF CHILDREN WITH CHRONIC DISEASE. THESE EXAMPLES ACCENTUATE THE NEED FOR CONTINUED PARTICIPATION OF HUMAN BIOLOGISTS IN THE STUDY OF GROWTH AND DEVELOPMENT AND THE CARE OF CHILDREN. 2009 19 2038 23 EPIGENETIC CHANGES PREDISPOSING TO TYPE 2 DIABETES IN INTRAUTERINE GROWTH RETARDATION. EPIDEMIOLOGIC STUDIES HAVE DEMONSTRATED AN ASSOCIATION BETWEEN INTRAUTERINE GROWTH RETARDATION AND A GREATER RISK OF CHRONIC DISEASE, INCLUDING CORONARY HEART DISEASE, HYPERTENSION, STROKE, AND TYPE 2 DIABETES IN ADULTHOOD. AN ADVERSE INTRAUTERINE ENVIRONMENT MAY AFFECT BOTH GROWTH AND DEVELOPMENT OF THE ORGANISM, PERMANENTLY PROGRAMMING ENDOCRINE AND METABOLIC FUNCTIONS. ONE OF THE MECHANISMS OF PROGRAMMING IS THE EPIGENETIC MODIFICATION OF GENE PROMOTERS INVOLVED IN THE CONTROL OF KEY METABOLIC PATHWAYS. THE AIM OF THIS REVIEW IS TO PROVIDE AN OVERVIEW OF THE EXPERIMENTAL EVIDENCE SHOWING THE EFFECTS OF EARLY EXPOSURE TO SUBOPTIMAL ENVIRONMENT ON EPIGENOME. THE KNOWLEDGE OF THE EPIGENETIC MARKERS OF PROGRAMMING MAY ALLOW THE IDENTIFICATION OF SUSCEPTIBLE INDIVIDUALS AND THE DESIGN OF TARGETED PREVENTION STRATEGIES. 2010 20 2700 34 EXCESS IRON: CONSIDERATIONS RELATED TO DEVELOPMENT AND EARLY GROWTH. WHAT EFFECTS MIGHT ARISE FROM EARLY LIFE EXPOSURES TO HIGH IRON? THIS REVIEW CONSIDERS THE SPECIFIC EFFECTS OF HIGH IRON ON THE BRAIN, STEM CELLS, AND THE PROCESS OF ERYTHROPOIESIS AND IDENTIFIES GAPS IN OUR KNOWLEDGE OF WHAT MOLECULAR DAMAGE MAY BE INCURRED BY OXIDATIVE STRESS THAT IS IMPARTED BY HIGH IRON STATUS IN EARLY LIFE. SPECIFIC AREAS TO ENHANCE RESEARCH ON THIS TOPIC INCLUDE THE FOLLOWING: LONGITUDINAL BEHAVIORAL STUDIES OF CHILDREN TO TEST ASSOCIATIONS BETWEEN IRON EXPOSURES AND MOOD, EMOTION, COGNITION, AND MEMORY; ANIMAL STUDIES TO DETERMINE EPIGENETIC CHANGES THAT REPROGRAM BRAIN DEVELOPMENT AND METABOLIC CHANGES IN EARLY LIFE THAT COULD BE FOLLOWED THROUGH THE LIFE COURSE; AND THE ESTABLISHMENT OF HUMAN EPIGENETIC MARKERS OF IRON EXPOSURES AND OXIDATIVE STRESS THAT COULD BE MONITORED FOR EARLY ORIGINS OF ADULT CHRONIC DISEASES. IN ADDITION, EFFORTS TO UNDERSTAND HOW IRON EXPOSURE INFLUENCES STEM CELL BIOLOGY COULD BE ENHANCED BY ESTABLISHING PLATFORMS TO COLLECT BIOLOGICAL SPECIMENS, INCLUDING UMBILICAL CORD BLOOD AND AMNIOTIC FLUID, TO BE MADE AVAILABLE TO THE RESEARCH COMMUNITY. AT THE MOLECULAR LEVEL, THERE IS A NEED TO BETTER UNDERSTAND STRESS ERYTHROPOIESIS AND CHANGES IN IRON METABOLISM DURING PREGNANCY AND DEVELOPMENT, ESPECIALLY WITH RESPECT TO REGULATORY CONTROL UNDER HIGH IRON CONDITIONS THAT MIGHT PROMOTE INEFFECTIVE ERYTHROPOIESIS AND IRON-LOADING ANEMIA. THESE INVESTIGATIONS SHOULD FOCUS NOT ONLY ON FACTORS SUCH AS HEPCIDIN AND ERYTHROFERRONE BUT SHOULD ALSO INCLUDE NEWLY IDENTIFIED INTERACTIONS BETWEEN TRANSFERRIN RECEPTOR-2 AND THE ERYTHROPOIETIN RECEPTOR. FINALLY, DESPITE OUR UNDERSTANDING THAT SEVERAL KEY MICRONUTRIENTS (E.G., VITAMIN A, COPPER, MANGANESE, AND ZINC) SUPPORT IRON'S FUNCTION IN ERYTHROPOIESIS, HOW THESE NUTRIENTS INTERACT REMAINS, TO OUR KNOWLEDGE, UNKNOWN. IT IS NECESSARY TO CONSIDER MANY FACTORS WHEN FORMULATING RECOMMENDATIONS ON IRON SUPPLEMENTATION. 2017