1 5192 131 PRENATAL ENVIRONMENTAL STRESSORS AND DNA METHYLATION LEVELS IN PLACENTA AND PERIPHERAL TISSUES OF MOTHERS AND NEONATES EVALUATED BY APPLYING ARTIFICIAL NEURAL NETWORKS. EXPOSURE TO ENVIRONMENTAL STRESSORS DURING PREGNANCY PLAYS AN IMPORTANT ROLE IN INFLUENCING SUBSEQUENT SUSCEPTIBILITY TO CERTAIN CHRONIC DISEASES THROUGH THE MODULATION OF EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION. OUR AIM WAS TO EXPLORE THE CONNECTIONS BETWEEN ENVIRONMENTAL EXPOSURES DURING GESTATION WITH DNA METHYLATION OF PLACENTAL CELLS, MATERNAL AND NEONATAL BUCCAL CELLS BY APPLYING ARTIFICIAL NEURAL NETWORKS (ANNS). A TOTAL OF 28 MOTHER-INFANT PAIRS WERE ENROLLED. DATA ON GESTATIONAL EXPOSURE TO ADVERSE ENVIRONMENTAL FACTORS AND ON MOTHER HEALTH STATUS WERE COLLECTED THROUGH THE ADMINISTRATION OF A QUESTIONNAIRE. DNA METHYLATION ANALYSES AT BOTH GENE-SPECIFIC AND GLOBAL LEVEL WERE ANALYZED IN PLACENTAS, MATERNAL AND NEONATAL BUCCAL CELLS. IN THE PLACENTA, THE CONCENTRATIONS OF VARIOUS METALS AND DIOXINS WERE ALSO ANALYZED. ANALYSIS OF ANNS REVEALED THAT SUBOPTIMAL BIRTH WEIGHT IS ASSOCIATED WITH PLACENTAL H19 METHYLATION, MATERNAL STRESS DURING PREGNANCY WITH METHYLATION LEVELS OF NR3C1 AND BDNF IN PLACENTAS AND MOTHER'S BUCCAL DNA, RESPECTIVELY, AND EXPOSURE TO AIR POLLUTANTS WITH MATERNAL MGMT METHYLATION. ASSOCIATIONS WERE ALSO OBSERVED BETWEEN PLACENTAL CONCENTRATIONS OF LEAD, CHROMIUM, CADMIUM AND MERCURY WITH METHYLATION LEVELS OF OXTR IN PLACENTAS, HSD11B2 IN MATERNAL BUCCAL CELLS AND PLACENTAS, MECP2 IN NEONATAL BUCCAL CELLS, AND MTHFR IN MATERNAL BUCCAL CELLS. FURTHERMORE, DIOXIN CONCENTRATIONS WERE ASSOCIATED WITH PLACENTAL RELN, NEONATAL HSD11B2 AND MATERNAL H19 GENE METHYLATION LEVELS. CURRENT RESULTS SUGGEST THAT EXPOSURE OF PREGNANT WOMEN TO ENVIRONMENTAL STRESSORS DURING PREGNANCY COULD INDUCE ABERRANT METHYLATION LEVELS IN GENES LINKED TO SEVERAL PATHWAYS IMPORTANT FOR EMBRYOGENESIS IN BOTH THE PLACENTA, POTENTIALLY AFFECTING FOETAL DEVELOPMENT, AND IN THE PERIPHERAL TISSUES OF MOTHERS AND INFANTS, POTENTIALLY PROVIDING PERIPHERAL BIOMARKERS OF ENVIRONMENTAL EXPOSURE. 2023 2 668 37 BNDF METHYLATION IN MOTHERS AND NEWBORNS IS ASSOCIATED WITH MATERNAL EXPOSURE TO WAR TRAUMA. BACKGROUND: THE BDNF GENE CODES FOR BRAIN-DERIVED NEUROTROPHIC FACTOR, A GROWTH FACTOR INVOLVED IN NEURAL DEVELOPMENT, CELL DIFFERENTIATION, AND SYNAPTIC PLASTICITY. PRESENT IN BOTH THE BRAIN AND PERIPHERY, BDNF PLAYS CRITICAL ROLES THROUGHOUT THE BODY AND IS ESSENTIAL FOR PLACENTAL AND FETAL DEVELOPMENT. RODENT STUDIES SHOW THAT EARLY LIFE STRESS, INCLUDING PRENATAL STRESS, BROADLY ALTERS BDNF METHYLATION, WITH PRESUMED CHANGES IN GENE EXPRESSION. NO STUDIES HAVE ASSESSED PRENATAL EXPOSURE TO MATERNAL TRAUMATIC STRESS AND BDNF METHYLATION IN HUMANS. THIS STUDY EXAMINED ASSOCIATIONS OF PRENATAL EXPOSURE TO MATERNAL STRESS AND BDNF METHYLATION AT CPG SITES ACROSS THE BDNF GENE. RESULTS: AMONG 24 MOTHERS AND NEWBORNS IN THE EASTERN DEMOCRATIC REPUBLIC OF CONGO, A REGION WITH EXTREME CONFLICT AND VIOLENCE TO WOMEN, MATERNAL EXPERIENCES OF WAR TRAUMA AND CHRONIC STRESS WERE ASSOCIATED WITH BDNF METHYLATION IN UMBILICAL CORD BLOOD, PLACENTAL TISSUE, AND MATERNAL VENOUS BLOOD. ASSOCIATIONS OF MATERNAL STRESS AND BDNF METHYLATION SHOWED HIGH TISSUE SPECIFICITY. THE MAJORITY OF SIGNIFICANT ASSOCIATIONS WERE OBSERVED IN PUTATIVE TRANSCRIPTION FACTOR BINDING REGIONS. CONCLUSIONS: THIS IS THE FIRST STUDY IN HUMANS TO EXAMINE BDNF METHYLATION IN RELATION TO PRENATAL EXPOSURE TO MATERNAL STRESS IN THREE TISSUES SIMULTANEOUSLY AND THE FIRST IN ANY MAMMALIAN SPECIES TO REPORT ASSOCIATIONS OF PRENATAL STRESS AND BDNF METHYLATION IN PLACENTAL TISSUE. THE FINDINGS ADD TO THE GROWING BODY OF EVIDENCE HIGHLIGHTING THE IMPORTANCE OF CONSIDERING EPIGENETIC EFFECTS WHEN EXAMINING THE IMPACTS OF TRAUMA AND STRESS, NOT ONLY FOR ADULTS BUT ALSO FOR OFFSPRING EXPOSED VIA EFFECTS TRANSMITTED BEFORE BIRTH. 2017 3 520 41 ASSOCIATIONS BETWEEN MATERNAL PRENATAL STRESS, METHYLATION CHANGES IN IGF1 AND IGF2, AND BIRTH WEIGHT. MATERNAL STRESS HAS BEEN LINKED TO LOW BIRTH WEIGHT IN NEWBORNS. ONE POTENTIAL PATHWAY INVOLVES EPIGENETIC CHANGES AT CANDIDATE GENES THAT MAY MEDIATE THE EFFECTS OF PRENATAL MATERNAL STRESS ON BIRTH WEIGHT. THIS RELATIONSHIP HAS BEEN DOCUMENTED IN STRESS-RELATED GENES, SUCH AS NR3C1. THERE IS LESS LITERATURE EXPLORING THE EFFECT OF STRESS ON GROWTH-RELATED GENES. IGF1 AND IGF2 HAVE BEEN IMPLICATED IN FETAL GROWTH AND DEVELOPMENT, THOUGH VIA DIFFERENT MECHANISMS AS IGF2 IS UNDER IMPRINTING CONTROL. IN THIS STUDY, WE TESTED FOR ASSOCIATIONS BETWEEN PRENATAL STRESS, METHYLATION OF IGF1 AND IGF2, AND BIRTH WEIGHT. A TOTAL OF 24 MOTHER-NEWBORN DYADS IN THE DEMOCRATIC REPUBLIC OF CONGO WERE ENROLLED. ETHNOGRAPHIC INTERVIEWS WERE CONDUCTED WITH MOTHERS AT DELIVERY TO GATHER CULTURALLY RELEVANT WAR-RELATED AND CHRONIC STRESSORS. DNA METHYLATION DATA WERE GENERATED FROM MATERNAL VENOUS, CORD BLOOD AND PLACENTAL TISSUE SAMPLES. MULTIVARIATE REGRESSIONS WERE USED TO TEST FOR ASSOCIATIONS BETWEEN STRESS MEASURES, DNA METHYLATION AND BIRTH WEIGHT IN EACH OF THE THREE TISSUE TYPES. WE FOUND AN ASSOCIATION BETWEEN IGF2 METHYLATION IN MATERNAL BLOOD AND BIRTH WEIGHT. PREVIOUS LITERATURE ON THE RELATIONSHIP BETWEEN IGF2 METHYLATION AND BIRTH WEIGHT HAS FOCUSED ON METHYLATION AT KNOWN DIFFERENTIALLY METHYLATED REGIONS IN CORD BLOOD OR PLACENTAL SAMPLES. OUR FINDINGS INDICATE THERE MAY BE LINKS BETWEEN THE MATERNAL EPIGENOME AND LOW BIRTH WEIGHT THAT RELY ON MECHANISMS OUTSIDE KNOWN IMPRINTING PATHWAYS. IT THUS MAY BE IMPORTANT TO CONSIDER THE EFFECT OF MATERNAL EXPOSURES AND EPIGENETIC PROFILES ON BIRTH WEIGHT EVEN IN THE SETTING OF MATERNALLY IMPRINTED GENES SUCH AS IGF2. 2018 4 649 37 BIRTHWEIGHT, MATERNAL WEIGHT TRAJECTORIES AND GLOBAL DNA METHYLATION OF LINE-1 REPETITIVE ELEMENTS. LOW BIRTHWEIGHT, PREMATURE BIRTH, INTRAUTERINE GROWTH RETARDATION, AND MATERNAL MALNUTRITION HAVE BEEN RELATED TO AN INCREASED RISK OF CARDIOVASCULAR DISEASE, TYPE 2 DIABETES MELLITUS, OBESITY, AND NEUROPSYCHIATRIC DISORDERS LATER IN LIFE. CONVERSELY, HIGH BIRTHWEIGHT HAS BEEN LINKED TO FUTURE RISK OF CANCER. GLOBAL DNA METHYLATION ESTIMATED BY THE METHYLATION OF REPETITIVE SEQUENCES IN THE GENOME IS AN INDICATOR OF SUSCEPTIBILITY TO CHRONIC DISEASES. WE USED DATA AND BIOSPECIMENS FROM AN EPIGENETIC BIRTH COHORT TO EXPLORE THE ASSOCIATION BETWEEN TRAJECTORIES OF FETAL AND MATERNAL WEIGHT AND LINE-1 METHYLATION IN 319 MOTHER-CHILD DYADS. NEWBORNS WITH LOW OR HIGH BIRTHWEIGHT HAD SIGNIFICANTLY LOWER LINE-1 METHYLATION LEVELS IN THEIR CORD BLOOD COMPARED TO NORMAL WEIGHT INFANTS AFTER ADJUSTING FOR GESTATIONAL AGE, SEX OF THE CHILD, MATERNAL AGE AT DELIVERY, AND MATERNAL SMOKING DURING PREGNANCY (P = 0.007 AND P = 0.036, RESPECTIVELY), BUT THE MAGNITUDE OF THE DIFFERENCE WAS SMALL. INFANTS BORN PREMATURELY ALSO HAD LOWER LINE-1 METHYLATION LEVELS IN CORD BLOOD COMPARED TO TERM INFANTS, AND THIS DIFFERENCE, THOUGH SMALL, WAS STATISTICALLY SIGNIFICANT (P = 0.004). WE DID NOT FIND IMPORTANT ASSOCIATIONS BETWEEN MATERNAL PREPREGNANCY BMI OR GESTATIONAL WEIGHT GAIN AND GLOBAL METHYLATION OF THE CORD BLOOD OR FETAL PLACENTAL TISSUE. IN CONCLUSION, WE FOUND SIGNIFICANT DIFFERENCES IN CORD BLOOD LINE-1 METHYLATION AMONG NEWBORNS WITH LOW AND HIGH BIRTHWEIGHT AS WELL AS AMONG PREMATURELY BORN INFANTS. FUTURE STUDIES MAY ELUCIDATE WHETHER CHROMOSOMAL INSTABILITIES OR OTHER FUNCTIONAL CONSEQUENCES OF THESE CHANGES CONTRIBUTE TO THE INCREASED RISK OF CHRONIC DISEASES AMONG INDIVIDUALS WITH THESE CHARACTERISTICS. 2011 5 4223 34 METHYLATION CHANGES AT NR3C1 IN NEWBORNS ASSOCIATE WITH MATERNAL PRENATAL STRESS EXPOSURE AND NEWBORN BIRTH WEIGHT. EARLY LIFE EXPERIENCES, INCLUDING THOSE IN UTERO, HAVE BEEN LINKED TO INCREASED RISK FOR ADULT-ONSET CHRONIC DISEASE. THE UNDERLYING ASSUMPTION IS THAT THERE IS A CRITICAL PERIOD OF DEVELOPMENTAL PLASTICITY IN UTERO WHEN SELECTION OF THE FETAL PHENOTYPE THAT IS BEST ADAPTED TO THE INTRAUTERINE ENVIRONMENT OCCURS. THE CURRENT STUDY IS THE FIRST TO TEST THE IDEA THAT EXTREME MATERNAL PSYCHOSOCIAL STRESSORS, AS OBSERVED IN THE DEMOCRATIC REPUBLIC OF CONGO, MAY MODIFY LOCUS-SPECIFIC EPIGENETIC MARKS IN THE NEWBORN RESULTING IN ALTERED HEALTH OUTCOMES. HERE WE SHOW A SIGNIFICANT CORRELATION BETWEEN CULTURALLY RELEVANT MEASURES OF MATERNAL PRENATAL STRESS, NEWBORN BIRTH WEIGHT AND NEWBORN METHYLATION IN THE PROMOTER OF THE GLUCOCORTICOID RECEPTOR NR3C1. INCREASED METHYLATION MAY CONSTRAIN PLASTICITY IN SUBSEQUENT GENE EXPRESSION AND RESTRICT THE RANGE OF STRESS ADAPTATION RESPONSES POSSIBLE IN AFFECTED INDIVIDUALS, THUS INCREASING THEIR RISK FOR ADULT-ONSET DISEASES. 2012 6 4085 43 MATERNAL OBESITY AND GESTATIONAL DIABETES REPROGRAM THE METHYLOME OF OFFSPRING BEYOND BIRTH BY INDUCING EPIGENETIC SIGNATURES IN METABOLIC AND DEVELOPMENTAL PATHWAYS. BACKGROUND: OBESITY IS A NEGATIVE CHRONIC METABOLIC HEALTH CONDITION THAT REPRESENTS AN ADDITIONAL RISK FOR THE DEVELOPMENT OF MULTIPLE PATHOLOGIES. EPIDEMIOLOGICAL STUDIES HAVE SHOWN HOW MATERNAL OBESITY OR GESTATIONAL DIABETES MELLITUS DURING PREGNANCY CONSTITUTE SERIOUS RISK FACTORS IN RELATION TO THE APPEARANCE OF CARDIOMETABOLIC DISEASES IN THE OFFSPRING. FURTHERMORE, EPIGENETIC REMODELLING MAY HELP EXPLAIN THE MOLECULAR MECHANISMS THAT UNDERLIE THESE EPIDEMIOLOGICAL FINDINGS. THUS, IN THIS STUDY WE EXPLORED THE DNA METHYLATION LANDSCAPE OF CHILDREN BORN TO MOTHERS WITH OBESITY AND GESTATIONAL DIABETES DURING THEIR FIRST YEAR OF LIFE. METHODS: WE USED ILLUMINA INFINIUM METHYLATIONEPIC BEADCHIP ARRAYS TO PROFILE MORE THAN 770,000 GENOME-WIDE CPG SITES IN BLOOD SAMPLES FROM A PAEDIATRIC LONGITUDINAL COHORT CONSISTING OF 26 CHILDREN BORN TO MOTHERS WHO SUFFERED FROM OBESITY OR OBESITY WITH GESTATIONAL DIABETES MELLITUS DURING PREGNANCY AND 13 HEALTHY CONTROLS (MEASUREMENTS TAKEN AT 0, 6 AND 12 MONTH; TOTAL N = 90). WE CARRIED OUT CROSS-SECTIONAL AND LONGITUDINAL ANALYSES TO DERIVE DNA METHYLATION ALTERATIONS ASSOCIATED WITH DEVELOPMENTAL AND PATHOLOGY-RELATED EPIGENOMICS. RESULTS: WE IDENTIFIED ABUNDANT DNA METHYLATION CHANGES DURING CHILD DEVELOPMENT FROM BIRTH TO 6 MONTHS AND, TO A LESSER EXTENT, UP TO 12 MONTHS OF AGE. USING CROSS-SECTIONAL ANALYSES, WE DISCOVERED DNA METHYLATION BIOMARKERS MAINTAINED ACROSS THE FIRST YEAR OF LIFE THAT COULD DISCRIMINATE CHILDREN BORN TO MOTHERS WHO SUFFERED FROM OBESITY OR OBESITY WITH GESTATIONAL DIABETES. IMPORTANTLY, ENRICHMENT ANALYSES SUGGESTED THAT THESE ALTERATIONS CONSTITUTE EPIGENETIC SIGNATURES THAT AFFECT GENES AND PATHWAYS INVOLVED IN THE METABOLISM OF FATTY ACIDS, POSTNATAL DEVELOPMENTAL PROCESSES AND MITOCHONDRIAL BIOENERGETICS, SUCH AS CPT1B, SLC38A4, SLC35F3 AND FN3K. FINALLY, WE OBSERVED EVIDENCE OF AN INTERACTION BETWEEN DEVELOPMENTAL DNA METHYLATION CHANGES AND MATERNAL METABOLIC CONDITION ALTERATIONS. CONCLUSIONS: OUR OBSERVATIONS HIGHLIGHT THE FIRST SIX MONTHS OF DEVELOPMENT AS BEING THE MOST CRUCIAL FOR EPIGENETIC REMODELLING. FURTHERMORE, OUR RESULTS SUPPORT THE EXISTENCE OF SYSTEMIC INTRAUTERINE FOETAL PROGRAMMING LINKED TO OBESITY AND GESTATIONAL DIABETES THAT AFFECTS THE CHILDHOOD METHYLOME BEYOND BIRTH, WHICH INVOLVES ALTERATIONS RELATED TO METABOLIC PATHWAYS, AND WHICH MAY INTERACT WITH ORDINARY POSTNATAL DEVELOPMENT PROGRAMMES. 2023 7 5166 35 PRECONCEPTION PATERNAL ALCOHOL EXPOSURE EXERTS SEX-SPECIFIC EFFECTS ON OFFSPRING GROWTH AND LONG-TERM METABOLIC PROGRAMMING. BACKGROUND: ALTHOUGH CLINICAL DATA SUPPORT AN ASSOCIATION BETWEEN PATERNAL ALCOHOL USE AND DEFICITS IN CHILD NEUROCOGNITIVE DEVELOPMENT, THE RELATIONSHIP BETWEEN PATERNAL DRINKING AND ALCOHOL-INDUCED GROWTH PHENOTYPES REMAINS CHALLENGING TO DEFINE. USING AN ESTABLISHED MOUSE MODEL OF CHRONIC EXPOSURE, PREVIOUS WORK BY OUR GROUP HAS LINKED PRECONCEPTION PATERNAL ALCOHOL USE TO SEX-SPECIFIC PATTERNS OF FETAL GROWTH RESTRICTION AND PLACENTAL DYSFUNCTION. THE AIM OF THE PRESENT STUDY WAS TO INVESTIGATE THE LONG-TERM IMPACT OF CHRONIC PRECONCEPTION PATERNAL ALCOHOL USE ON OFFSPRING GROWTH AND METABOLIC PROGRAMMING. RESULTS: PRECONCEPTION PATERNAL ALCOHOL EXPOSURE INDUCED A PROLONGED PERIOD OF FETAL GESTATION AND AN INCREASED INCIDENCE OF INTRAUTERINE GROWTH RESTRICTION, WHICH AFFECTED THE MALE OFFSPRING TO A GREATER EXTENT THAN THE FEMALES. WHILE THE FEMALE OFFSPRING OF ETHANOL-EXPOSED MALES WERE ABLE TO MATCH THE BODY WEIGHTS OF THE CONTROLS WITHIN THE FIRST 2 WEEKS OF POSTNATAL LIFE, MALE OFFSPRING CONTINUED TO DISPLAY AN 11% REDUCTION IN WEIGHT AT 5 WEEKS OF AGE AND A 6% REDUCTION AT 8 WEEKS OF AGE. THE OBSERVED GROWTH DEFICITS ASSOCIATED WITH INSULIN HYPERSENSITIVITY IN THE MALE OFFSPRING, WHILE IN CONTRAST, FEMALES DISPLAYED A MODEST LAG IN THEIR GLUCOSE TOLERANCE TEST. THESE METABOLIC DEFECTS WERE ASSOCIATED WITH AN UP-REGULATION OF GENES WITHIN THE PRO-FIBROTIC TGF-BETA SIGNALING PATHWAY AND INCREASED LEVELS OF CELLULAR HYDROXYPROLINE WITHIN THE LIVERS OF THE MALE OFFSPRING. WE OBSERVED SUPPRESSED CYTOKINE PROFILES WITHIN THE LIVER AND PANCREAS OF BOTH THE MALE AND FEMALE OFFSPRING, WHICH CORRELATED WITH THE UP-REGULATION OF GENES IN THE LIVERX/RETINOIDX/FARNESOIDX RECEPTOR PATHWAYS. HOWEVER, PATTERNS OF GENE EXPRESSION WERE HIGHLY VARIABLE BETWEEN THE OFFSPRING OF ALCOHOL-EXPOSED SIRES. IN THE ADULT OFFSPRING OF ALCOHOL-EXPOSED MALES, WE DID NOT OBSERVE ANY DIFFERENCES IN THE ALLELIC EXPRESSION OF IGF2 OR ANY OTHER IMPRINTED GENES. CONCLUSIONS: THE IMPACT OF PATERNAL ALCOHOL USE ON CHILD DEVELOPMENT IS POORLY EXPLORED AND REPRESENTS A SIGNIFICANT GAP IN OUR UNDERSTANDING OF THE TERATOGENIC EFFECTS OF ETHANOL. OUR STUDIES IMPLICATE PATERNAL EXPOSURE HISTORY AS AN ADDITIONAL AND IMPORTANT MODIFIER OF ALCOHOL-INDUCED GROWTH PHENOTYPES AND CHALLENGE THE CURRENT MATERNAL-CENTRIC EXPOSURE PARADIGM. 2019 8 1439 41 DIFFERENTIAL PLACENTAL CPG METHYLATION IS ASSOCIATED WITH CHRONIC LUNG DISEASE OF PREMATURITY. BACKGROUND: CHRONIC LUNG DISEASE (CLD) IS THE MOST COMMON PULMONARY MORBIDITY IN EXTREMELY PRETERM INFANTS. IT IS UNCLEAR TO WHAT EXTENT PRENATAL EXPOSURES INFLUENCE THE RISK OF CLD. EPIGENETIC VARIATION IN PLACENTA DNA METHYLATION MAY BE ASSOCIATED WITH DIFFERENTIAL RISK OF CLD, AND THESE ASSOCIATIONS MAY BE DEPENDENT UPON SEX. METHODS: DATA WERE OBTAINED FROM A MULTI-CENTER COHORT OF INFANTS BORN EXTREMELY PRETERM (<28 WEEKS' GESTATION) AND AN EPIGENOME-WIDE APPROACH WAS USED TO IDENTIFY ASSOCIATIONS BETWEEN PLACENTAL DNA METHYLATION AND CLD (N = 423). ASSOCIATIONS WERE EVALUATED USING ROBUST LINEAR REGRESSION ADJUSTING FOR COVARIATES, WITH A FALSE DISCOVERY RATE OF 0.05. ANALYSES STRATIFIED BY SEX WERE USED TO ASSESS DIFFERENCES IN METHYLATION-CLD ASSOCIATIONS. RESULTS: CLD WAS ASSOCIATED WITH DIFFERENTIAL METHYLATION AT 49 CPG SITES REPRESENTING 46 GENES IN THE PLACENTA. CLD WAS ASSOCIATED WITH DIFFERENTIAL METHYLATION OF PROBES WITHIN GENES RELATED TO PATHWAYS INVOLVED IN FETAL LUNG DEVELOPMENT, SUCH AS P53 SIGNALING AND MYO-INOSITOL BIOSYNTHESIS. ASSOCIATIONS BETWEEN CPG METHYLATION AND CLD DIFFERED BY SEX. CONCLUSIONS: DIFFERENTIAL PLACENTAL METHYLATION WITHIN GENES WITH KEY ROLES IN FETAL LUNG DEVELOPMENT MAY REFLECT COMPLEX CELL SIGNALING BETWEEN THE PLACENTA AND FETUS WHICH MEDIATE CLD RISK. THESE PATHWAYS APPEAR TO BE DISTINCT BASED ON FETAL SEX. IMPACT: IN EXTREMELY PRETERM INFANTS, DIFFERENTIAL METHYLATION OF CPG SITES WITHIN PLACENTAL GENES INVOLVED IN PATHWAYS RELATED TO CELL SIGNALING, OXIDATIVE STRESS, AND TROPHOBLAST INVASION IS ASSOCIATED WITH CHRONIC LUNG DISEASE OF PREMATURITY. DNA METHYLATION PATTERNS ASSOCIATED WITH CHRONIC LUNG DISEASE WERE DISTINCTLY BASED ON FETAL SEX, SUGGESTING A POTENTIAL MECHANISM UNDERLYING DIMORPHIC PHENOTYPES. MECHANISMS RELATED TO FETAL HYPOXIA AND PLACENTAL MYO-INOSITOL SIGNALING MAY PLAY A ROLE IN FETAL LUNG PROGRAMMING AND THE DEVELOPMENTAL ORIGINS OF CHRONIC LUNG DISEASE. CONTINUED RESEARCH OF THE RELATIONSHIP BETWEEN THE PLACENTAL EPIGENOME AND CHRONIC LUNG DISEASE COULD INFORM EFFORTS TO AMELIORATE OR PREVENT THIS CONDITION. 2022 9 5294 33 PROTECTIVE EFFECTS OF MATERNAL METHYL DONOR SUPPLEMENTATION ON ADULT OFFSPRING OF HIGH FAT DIET-FED DAMS. OBESITY HAS BECOME A GLOBAL PUBLIC HEALTH PROBLEM ASSOCIATED WITH METABOLIC DYSFUNCTION AND CHRONIC DISORDERS. IT HAS BEEN SHOWN THAT THE RISK OF OBESITY AND THE DNA METHYLATION PROFILES OF THE OFFSPRING CAN BE AFFECTED BY MATERNAL NUTRITION, SUCH AS HIGH-FAT DIET (HFD) CONSUMPTION. THE AIM OF THIS STUDY WAS TO INVESTIGATE WHETHER METABOLIC DYSREGULATION AND PHYSIOLOGICAL ABNORMALITIES IN OFFSPRING CAUSED BY MATERNAL HFD CAN BE ALLEVIATED BY THE TREATMENT OF METHYL DONORS DURING PREGNANCY AND LACTATION OF DAMS. FEMALE C57BL/6 MICE WERE ASSIGNED TO SPECIFIC GROUPS AND GIVEN DIFFERENT NUTRIENTS (CONTROL DIET, CONTROL+MET, HFD AND HFD+MET) THROUGHOUT GESTATION AND LACTATION. OFFSPRING OF EACH GROUP WERE WEANED ONTO A CONTROL DIET AT 3 WEEKS OF AGE. PHYSIOLOGICAL (WEIGHT GAIN AND ADIPOSE COMPOSITION) AND METABOLIC (PLASMA BIOCHEMICAL ANALYSES) OUTCOMES WERE ASSESSED IN MALE AND FEMALE ADULT OFFSPRING. EXPRESSION AND DNA METHYLATION PROFILES OF OBESOGENIC-RELATED GENES INCLUDING PPAR GAMMA, FATTY ACID SYNTHASE, LEPTIN AND ADIPONECTIN WERE ALSO DETECTED IN VISCERAL FAT OF OFFSPRING. THE RESULTS SHOWED THAT DIETARY SUPPLEMENTATION WITH METHYL DONORS CAN PREVENT THE ADVERSE EFFECTS OF MATERNAL HFD ON OFFSPRING. CHANGES IN THE EXPRESSION AND DNA METHYLATION OF OBESOGENIC-RELATED GENES INDICATED THAT EPIGENETIC REGULATION MAY CONTRIBUTE TO THE EFFECTS OF MATERNAL DIETARY FACTORS ON OFFSPRING OUTCOMES. 2016 10 2419 43 EPIGENETIC SIGNATURE OF CHRONIC MATERNAL STRESS LOAD DURING PREGNANCY MIGHT BE A POTENTIAL BIOMARKER FOR SPONTANEOUS PRETERM BIRTH. PRETERM BIRTH IS THE LEADING CAUSE OF MORTALITY IN NEWBORN INFANTS AND CAN LEAD TO SIGNIFICANT NEONATAL MORBIDITIES. SPONTANEOUS PRETERM BIRTH ACCOUNTS FOR AT LEAST 50.0% OF ALL PRETERM BIRTHS. WE ARGUE THAT CHRONIC MATERNAL STRESS LOAD, WHICH IS AN IMPORTANT RISK FACTOR FOR SPONTANEOUS PRETERM BIRTH, COULD BE REPRESENTED BY EPIGENETIC SIGNATURE OF SEVERAL SPECIFIC GENETIC LOCI IN THE MOTHER'S BLOOD. A LITERATURE SEARCH WAS DONE IN PUBMED WITH THE FOLLOWING KEYWORDS: "DNA METHYLATION," "EPIGENETICS," "MATERNAL STRESS" AND "PRETERM BIRTH" FROM YEAR 2000 TO 2017. WE SUGGEST THAT THESE GENETIC LOCI MIGHT BE RELATED TO VULNERABILITY AND HYPERSENSIBILITY OF STRESS RESPONSE DURING PREGNANCY IN WOMEN WITH PRETERM BIRTHS. THE MOTHER'S EPI-GENETIC STRESS BIOPROFILE WAS SUPPOSED TO BE A RESULT OF CHRONIC MATERNAL STRESS LOAD SINCE HER BIRTH. THIS EPIGENETIC BIOPROFILE MIGHT ALSO BE A POTENTIAL BIOMARKER FOR SPONTANEOUS PRETERM BIRTH. DNA METHYLATION CHANGES ARE TISSUE-SPECIFIC AND HUMAN STRESS RESPONSE MANIFESTS MOSTLY THROUGH THE CENTRAL NERVOUS SYSTEM (CNS). NEVERTHELESS, WE FOUND EVIDENCE THAT METHYLATION CHANGES OF DNA ISOLATED FROM BLOOD LEUCOCYTES MIGHT BE A RELIABLE MEASURE OF STRESS-RELATED EPIGENETIC CHANGES THAT OCCUR IN THE CNS. EVALUATING BIOLOGICAL MECHANISMS THROUGH THE DEVELOPMENT OF SIMPLE ASSAYS BASED ON EPIGENETIC CHANGES TO MEASURE CHRONIC STRESS LOADS IN EXPECTANT MOTHERS CAN LEAD TO OUR ABILITY TO PREPARE MORE EFFECTIVE MEASURES FOR THE PREVENTION OF PRETERM BIRTHS, AS WELL AS LEADING TO MORE EFFECTIVE TREATMENT STRATEGIES FOR BOTH EXPECTANT MOTHERS AND THEIR NEWBORNS. 2018 11 4079 39 MATERNAL L-CARNITINE SUPPLEMENTATION AMELIORATES RENAL UNDERDEVELOPMENT AND EPIGENETIC CHANGES IN MALE MICE OFFSPRING DUE TO MATERNAL SMOKING. OBJECTIVES: EPIDEMIOLOGICAL AND ANIMAL STUDIES SHOWED THAT L-CARNITINE (LC) SUPPLEMENTATION CAN AMELIORATE OXIDATIVE STRESS-INDUCED TISSUES DAMAGE. WE HAVE PREVIOUSLY SHOWN THAT MATERNAL CIGARETTE SMOKE EXPOSURE (SE) CAN INCREASE RENAL OXIDATIVE STRESS IN NEWBORN OFFSPRING WITH POSTNATAL KIDNEY UNDERDEVELOPMENT AND RENAL DYSFUNCTION IN ADULTHOOD, WHICH WERE NORMALISED BY LC ADMINISTRATION IN THE SE DAMS DURING PREGNANCY. EXPOSURE TO AN ADVERSE INTRAUTERINE ENVIRONMENT MAY LEAD TO ALTERATION IN THE EPIGENOME, A MECHANISM BY WHICH ADVERSE PRENATAL CONDITIONS INCREASE THE SUSCEPTIBILITY TO CHRONIC DISEASE LATER IN LIFE. THE CURRENT STUDY AIMED TO DETERMINE WHETHER MATERNAL SE INDUCES EPIGENETIC CHANGES IN THE OFFSPRING'S KIDNEY ARE ASSOCIATED WITH RENAL UNDERDEVELOPMENT, AND THE PROTECTIVE EFFECT OF MATERNAL LC SUPPLEMENTATION. METHOD: FEMALE BALB/C MICE (7 WEEKS) WERE EXPOSED TO CIGARETTE SMOKE (SE) OR AIR (SHAM) FOR 6 WEEKS PRIOR TO MATING, DURING GESTATION AND LACTATION. A SUBGROUP OF THE SE DAMS RECEIVED LC VIA DRINKING WATER (SE + LC, 1.5 MMOL/L) THROUGHOUT GESTATION AND LACTATION. MALE OFFSPRING WERE STUDIED AT POSTNATAL DAY (P)1, P20, AND 13 WEEKS. RESULTS: MATERNAL SE ALTERED THE EXPRESSION OF RENAL DEVELOPMENT MARKERS GLIAL CELL LINE-DERIVED NEUROTROPHIC FACTOR AND FIBROBLAST GROWTH FACTOR 2, WHICH WERE ASSOCIATED WITH INCREASED RENAL GLOBAL DNA METHYLATION AND DNA METHYLTRANSFERASE 1 MRNA EXPRESSION AT BIRTH. THESE DISORDERS WERE REVERSED BY MATERNAL LC ADMINISTRATION. CONCLUSION: THE EFFECT OF MATERNAL SE ON RENAL UNDERDEVELOPMENT INVOLVES GLOBAL EPIGENETIC ALTERATIONS FROM BIRTH, WHICH CAN BE PREVENTED BY MATERNAL LC SUPPLEMENTATION. 2019 12 3119 37 GESTATIONAL EXPOSURE TO PARTICULATE AIR POLLUTION EXACERBATES THE GROWTH PHENOTYPES INDUCED BY PRECONCEPTION PATERNAL ALCOHOL USE: A MULTIPLEX MODEL OF EXPOSURE. IT IS NOW CLEAR THAT PARENTAL HISTORIES OF DRUG USE, TOXICANT EXPOSURE, AND SOCIAL STRESS ALL HAVE A SIGNIFICANT INFLUENCE ON THE HEALTH AND DEVELOPMENT OF THE NEXT GENERATION. HOWEVER, THE ABILITY OF EPIGENETIC PARENTAL LIFE MEMORIES TO INTERACT WITH SUBSEQUENT GESTATIONAL EXPOSURES AND CUMULATIVELY MODIFY THE DEVELOPMENTAL TRAJECTORY OF THE OFFSPRING REMAINS AN UNEXPLORED PERSPECTIVE IN TOXICOLOGY. STUDIES FROM OUR LABORATORY HAVE IDENTIFIED MALE-SPECIFIC POSTNATAL GROWTH RESTRICTION IN A MOUSE MODEL OF CHRONIC, PRECONCEPTION PATERNAL ALCOHOL EXPOSURE. THE GOAL OF THE CURRENT STUDY WAS TO DETERMINE IF PATERNAL ALCOHOL USE, BEFORE CONCEPTION, COULD MODIFY THE SUSCEPTIBILITY OF THE OFFSPRING TO A COMPLETELY SEPARATE EXPOSURE ENCOUNTERED BY THE MOTHER DURING PREGNANCY. IN INDEPENDENT EXPERIMENTS, WE PREVIOUSLY IDENTIFIED ALTERED DEVELOPMENTAL PROGRAMMING AND INCREASED MARKERS OF SEVERE ASTHMA INDUCED BY GESTATIONAL EXPOSURE TO PARTICULATE AIR POLLUTION. IN THIS STUDY, MALE MICE WERE EXPOSED TO EITHER THE CONTROL OR ALCOHOL PRECONCEPTION TREATMENTS, THEN MATED TO NAIVE FEMALES, WHICH WE SUBSEQUENTLY EXPOSED TO AN ULTRAFINE MIXTURE OF PARTICULATE MATTER VIA INHALATION. INDIVIDUALLY, NEITHER PRECONCEPTION PATERNAL DRINKING NOR GESTATIONAL EXPOSURES TO PARTICULATE AIR POLLUTION IMPACTED THE POSTNATAL GROWTH OF FEMALE OFFSPRING. HOWEVER, WHEN BOTH EXPOSURES WERE COMBINED, FEMALES DISPLAYED A 30% REDUCTION IN WEIGHT GAIN. UNEXPECTEDLY, THIS EXPOSURE PARADIGM RESULTED IN A DRAMATIC POSTNATAL INCREASE IN LITTER LOSS DUE TO MATERNAL CANNIBALISM, WHICH PREVENTED ADDITIONAL MEASURES OF OFFSPRING HEALTH. THESE PRELIMINARY STUDIES PROVIDE EVIDENCE OF A COMPLEX INTERPLAY BETWEEN PRECONCEPTION LIFE HISTORY AND INTRAUTERINE ENVIRONMENTAL FACTORS IN THE CONTROL OF POSTNATAL GROWTH. 2020 13 4065 38 MATERNAL AND GESTATIONAL INFLUENCES ON CHILDHOOD BLOOD PRESSURE. EXPOSURES THAT CONTRIBUTE TO A SUB-OPTIMAL INTRAUTERINE ENVIRONMENT CAN HAVE AN EFFECT ON THE DEVELOPING FETUS. IMPAIRED FETAL GROWTH THAT RESULTS IN LOW BIRTH WEIGHT IS AN ESTABLISHED RISK FACTOR FOR CARDIO-METABOLIC DISORDERS LATER IN LIFE. RECENT EPIDEMIOLOGIC AND PROSPECTIVE COHORT STUDIES THAT INCLUDE THE MATERNAL AND GESTATIONAL PERIOD HAVE IDENTIFIED MATERNAL AND GESTATIONAL CONDITIONS THAT CONFER INCREASED RISK FOR SUBSEQUENT CARDIO-METABOLIC DISORDERS IN THE ABSENCE OF LOW BIRTH WEIGHT. MATERNAL PRE-CONCEPTION HEALTH STATUS, INCLUDING CHRONIC OBESITY AND TYPE 2 DIABETES, INCREASE RISK FOR CHILDHOOD OBESITY AND OBESITY-RELATED HIGHER BLOOD PRESSURE (BP) IN CHILD OFFSPRING. MATERNAL GESTATIONAL EXPOSURES, INCLUDING GESTATIONAL DIABETES, GESTATIONAL HYPERTENSION, AND PREECLAMPSIA, ARE ASSOCIATED WITH HIGHER BP IN OFFSPRING. OTHER MATERNAL EXPOSURES SUCH AS CIGARETTE SMOKE AND AIR POLLUTION ALSO INCREASE RISK FOR HIGHER BP IN CHILD OFFSPRING. RECENT, BUT LIMITED, DATA INDICATE THAT ASSISTED REPRODUCTIVE TECHNOLOGIES CAN BE ASSOCIATED WITH HYPERTENSION IN CHILDHOOD, DESPITE OTHERWISE NORMAL GESTATION AND HEALTHY NEWBORN. GESTATIONAL EXPOSURES ASSOCIATED WITH HIGHER BP IN CHILDHOOD CAN BE RELATED TO FAMILIAL LIFESTYLE FACTORS, GENETICS, OR EPIGENETIC MODIFICATION OF FETAL DEOXYRIBONUCLEIC ACID (DNA). THESE FACTORS, OR COMBINATION OF FACTORS, AS WELL AS OTHER ADVERSE INTRAUTERINE CONDITIONS, COULD INDUCE FETAL PROGRAMING LEADING TO HEALTH CONSEQUENCES IN LATER LIFE. CURRENT AND DEVELOPING RESEARCH WILL PROVIDE ADDITIONAL INSIGHTS ON GESTATIONAL EXPOSURES AND FETAL ADJUSTMENTS THAT INCREASE RISK FOR HIGHER BP LEVELS IN CHILDHOOD. 2020 14 2677 29 EVALUATING THE CHALLENGES AND REPRODUCIBILITY OF STUDIES INVESTIGATING DNA METHYLATION SIGNATURES OF PSYCHOLOGICAL STRESS. PSYCHOLOGICAL STRESS CAN INCREASE THE RISK OF A WIDE RANGE OF NEGATIVE HEALTH OUTCOMES. STUDIES HAVE BEEN COMPLETED TO DETERMINE IF DNA METHYLATION CHANGES OCCUR IN THE HUMAN BRAIN BECAUSE OF STRESS AND ARE ASSOCIATED WITH LONG-TERM EFFECTS AND DISEASE, BUT RESULTS HAVE BEEN INCONSISTENT. HUMAN CANDIDATE GENE STUDIES (150) AND EPIGENOME-WIDE ASSOCIATION STUDIES (67) WERE SYSTEMATICALLY EVALUATED TO ASSESS HOW DNA METHYLATION IS IMPACTED BY STRESS DURING THE PRENATAL PERIOD, EARLY CHILDHOOD AND ADULTHOOD. THE ASSOCIATION BETWEEN DNA METHYLATION OF NR3C1 EXON 1F AND CHILD MALTREATMENT AND EARLY LIFE ADVERSITY WAS WELL DEMONSTRATED, BUT OTHER GENES DID NOT EXHIBIT A CLEAR ASSOCIATION. THE REPRODUCIBILITY OF INDIVIDUAL CPG SITES IN EPIGENOME-WIDE ASSOCIATION STUDIES WAS ALSO POOR. HOWEVER, BIOLOGICAL PATHWAYS, INCLUDING STRESS RESPONSE, BRAIN DEVELOPMENT AND IMMUNITY, HAVE BEEN CONSISTENTLY IDENTIFIED ACROSS DIFFERENT STRESSORS THROUGHOUT THE LIFE SPAN. FUTURE STUDIES WOULD BENEFIT FROM THE INCREASED SAMPLE SIZE, LONGITUDINAL DESIGN, STANDARDIZED METHODOLOGY, OPTIMAL QUALITY CONTROL, AND IMPROVED STATISTICAL PROCEDURES. 2022 15 1503 32 DNA METHYLATION AND GENE EXPRESSION DIFFERENCES IN CHILDREN CONCEIVED IN VITRO OR IN VIVO. EPIDEMIOLOGICAL DATA INDICATE THAT CHILDREN CONCEIVED IN VITRO HAVE A GREATER RELATIVE RISK OF LOW BIRTH-WEIGHT, MAJOR AND MINOR BIRTH DEFECTS, AND RARE DISORDERS INVOLVING IMPRINTED GENES, SUGGESTING THAT EPIGENETIC CHANGES MAY BE ASSOCIATED WITH ASSISTED REPRODUCTION. WE EXAMINED DNA METHYLATION AT MORE THAN 700 GENES (1536 CPG SITES) IN PLACENTA AND CORD BLOOD AND MEASURED GENE EXPRESSION LEVELS OF A SUBSET OF GENES THAT DIFFERED IN METHYLATION LEVELS BETWEEN CHILDREN CONCEIVED IN VITRO VERSUS IN VIVO. OUR RESULTS SUGGEST THAT IN VITRO CONCEPTION IS ASSOCIATED WITH LOWER MEAN METHYLATION AT CPG SITES IN PLACENTA AND HIGHER MEAN METHYLATION AT CPG SITES IN CORD BLOOD. WE ALSO FIND THAT IN VITRO CONCEPTION-ASSOCIATED DNA METHYLATION DIFFERENCES ARE ASSOCIATED WITH GENE EXPRESSION DIFFERENCES AT BOTH IMPRINTED AND NON-IMPRINTED GENES. THE RANGE OF INTER-INDIVIDUAL VARIATION IN GENE EXPRESSION OF THE IN VITRO AND IN VIVO GROUPS OVERLAPS SUBSTANTIALLY BUT SOME INDIVIDUALS FROM THE IN VITRO GROUP DIFFER FROM THE IN VIVO GROUP MEAN BY MORE THAN TWO STANDARD DEVIATIONS. SEVERAL OF THE GENES WHOSE EXPRESSION DIFFERS BETWEEN THE TWO GROUPS HAVE BEEN IMPLICATED IN CHRONIC METABOLIC DISORDERS, SUCH AS OBESITY AND TYPE II DIABETES. THESE FINDINGS SUGGEST THAT THERE MAY BE EPIGENETIC DIFFERENCES IN THE GAMETES OR EARLY EMBRYOS DERIVED FROM COUPLES UNDERGOING TREATMENT FOR INFERTILITY. ALTERNATIVELY, ASSISTED REPRODUCTION TECHNOLOGY MAY HAVE AN EFFECT ON GLOBAL PATTERNS OF DNA METHYLATION AND GENE EXPRESSION. IN EITHER CASE, THESE DIFFERENCES OR CHANGES MAY AFFECT LONG-TERM PATTERNS OF GENE EXPRESSION. 2009 16 249 33 ADVANCED AGING PHENOTYPE IS REVEALED BY EPIGENETIC MODIFICATIONS IN RAT LIVER AFTER IN UTERO MALNUTRITION. ADVERSE ENVIRONMENTAL EXPOSURES OF MOTHERS DURING FETAL PERIOD PREDISPOSE OFFSPRING TO A RANGE OF AGE-RELATED DISEASES EARLIER IN LIFE. HERE, WE SET TO DETERMINE WHETHER A DEREGULATED EPIGENETIC PATTERN IS SIMILAR IN YOUNG ANIMALS WHOSE MOTHERS' NUTRITION WAS MODULATED DURING FETAL GROWTH TO THAT ACQUIRED DURING NORMAL AGING IN ANIMALS. USING A RODENT MODEL OF MATERNAL UNDERNUTRITION (UN) OR OVERNUTRITION (ON), WE EXAMINED CYTOSINE METHYLATION PROFILES OF LIVER FROM YOUNG FEMALE OFFSPRING AND COMPARED THEM TO AGE-MATCHED YOUNG CONTROLS AND AGED (20-MONTH-OLD) ANIMALS. HELP-TAGGING, A GENOMEWIDE RESTRICTION ENZYME AND SEQUENCING ASSAY DEMONSTRATES THAT FETAL EXPOSURE TO TWO DIFFERENT MATERNAL DIETS IS ASSOCIATED WITH NONRANDOM DYSREGULATION OF METHYLATION LEVELS WITH PROFILES SIMILAR TO THOSE SEEN IN NORMAL AGING ANIMALS AND OCCUR IN REGIONS MAPPED TO GENES RELEVANT TO METABOLIC DISEASES AND AGING. FUNCTIONAL CONSEQUENCES WERE ASSESSED BY GENE EXPRESSION AT 9 WEEKS OLD WITH MORE SIGNIFICANT CHANGES AT 6 MONTHS OF AGE. EARLY DEVELOPMENTAL EXPOSURES TO UNFAVORABLE MATERNAL DIETS RESULT IN ALTERED METHYLATION PROFILES AND TRANSCRIPTIONAL DYSREGULATION IN PRKCB, PC, NCOR2, AND SMAD3 THAT IS ALSO SEEN WITH NORMAL AGING. THESE NOTCH PATHWAY AND LIPOGENESIS GENES MAY BE USEFUL FOR PREDICTION OF LATER SUSCEPTIBILITY TO CHRONIC DISEASE. 2016 17 2472 27 EPIGENETIC TRANSMISSION OF THE IMPACT OF EARLY STRESS ACROSS GENERATIONS. BACKGROUND: TRAUMATIC EXPERIENCES IN EARLY LIFE ARE RISK FACTORS FOR THE DEVELOPMENT OF BEHAVIORAL AND EMOTIONAL DISORDERS. SUCH DISORDERS CAN PERSIST THROUGH ADULTHOOD AND HAVE OFTEN BEEN REPORTED TO BE TRANSMITTED ACROSS GENERATIONS. METHODS: TO INVESTIGATE THE TRANSGENERATIONAL EFFECT OF EARLY STRESS, MICE WERE EXPOSED TO CHRONIC AND UNPREDICTABLE MATERNAL SEPARATION FROM POSTNATAL DAY 1 TO 14. RESULTS: WE SHOW THAT CHRONIC AND UNPREDICTABLE MATERNAL SEPARATION INDUCES DEPRESSIVE-LIKE BEHAVIORS AND ALTERS THE BEHAVIORAL RESPONSE TO AVERSIVE ENVIRONMENTS IN THE SEPARATED ANIMALS WHEN ADULT. MOST OF THE BEHAVIORAL ALTERATIONS ARE FURTHER EXPRESSED BY THE OFFSPRING OF MALES SUBJECTED TO MATERNAL SEPARATION, DESPITE THE FACT THAT THESE MALES ARE REARED NORMALLY. CHRONIC AND UNPREDICTABLE MATERNAL SEPARATION ALSO ALTERS THE PROFILE OF DNA METHYLATION IN THE PROMOTER OF SEVERAL CANDIDATE GENES IN THE GERMLINE OF THE SEPARATED MALES. COMPARABLE CHANGES IN DNA METHYLATION ARE ALSO PRESENT IN THE BRAIN OF THE OFFSPRING AND ARE ASSOCIATED WITH ALTERED GENE EXPRESSION. CONCLUSIONS: THESE FINDINGS HIGHLIGHT THE NEGATIVE IMPACT OF EARLY STRESS ON BEHAVIORAL RESPONSES ACROSS GENERATIONS AND ON THE REGULATION OF DNA METHYLATION IN THE GERMLINE. 2010 18 2101 39 EPIGENETIC EFFECTS OF PRENATAL STRESS ON 11BETA-HYDROXYSTEROID DEHYDROGENASE-2 IN THE PLACENTA AND FETAL BRAIN. MATERNAL EXPOSURE TO STRESS DURING PREGNANCY IS ASSOCIATED WITH SIGNIFICANT ALTERATIONS IN OFFSPRING NEURODEVELOPMENT AND ELEVATED MATERNAL GLUCOCORTICOIDS LIKELY PLAY A CENTRAL ROLE IN MEDIATING THESE EFFECTS. PLACENTAL 11BETA-HYDROXYSTEROID DEHYDROGENASE TYPE 2 (HSD11B2) BUFFERS THE IMPACT OF MATERNAL GLUCOCORTICOID EXPOSURE BY CONVERTING CORTISOL/CORTICOSTERONE INTO INACTIVE METABOLITES. HOWEVER, PREVIOUS STUDIES INDICATE THAT MATERNAL ADVERSITY DURING THE PRENATAL PERIOD CAN LEAD TO A DOWN-REGULATION OF THIS ENZYME. IN THE CURRENT STUDY, WE EXAMINED THE IMPACT OF PRENATAL STRESS (CHRONIC RESTRAINT STRESS DURING GESTATIONAL DAYS 14-20) IN LONG EVANS RATS ON HSD11B2 MRNA IN THE PLACENTA AND FETAL BRAIN (E20) AND ASSESSED THE ROLE OF EPIGENETIC MECHANISMS IN THESE STRESS-INDUCED EFFECTS. IN THE PLACENTA, PRENATAL STRESS WAS ASSOCIATED WITH A SIGNIFICANT DECREASE IN HSD11B2 MRNA, INCREASED MRNA LEVELS OF THE DNA METHYLTRANSFERASE DNMT3A, AND INCREASED DNA METHYLATION AT SPECIFIC CPG SITES WITHIN THE HSD11B2 GENE PROMOTER. WITHIN THE FETAL HYPOTHALAMUS, THOUGH WE FIND NO STRESS-INDUCED EFFECTS ON HSD11B2 MRNA LEVELS, PRENATAL STRESS INDUCED DECREASED CPG METHYLATION WITHIN THE HSD11B2 PROMOTER AND INCREASED METHYLATION AT SITES WITHIN EXON 1. WITHIN THE FETAL CORTEX, HSD11B2 MRNA AND DNA METHYLATION LEVELS WERE NOT ALTERED BY PRENATAL STRESS, THOUGH WE DID FIND STRESS-INDUCED ELEVATIONS IN DNMT1 MRNA IN THIS BRAIN REGION. WITHIN INDIVIDUALS, WE IDENTIFIED CPG SITES WITHIN THE HSD11B2 GENE PROMOTER AND EXON 1 AT WHICH DNA METHYLATION LEVELS WERE HIGHLY CORRELATED BETWEEN THE PLACENTA AND FETAL CORTEX. OVERALL, OUR FINDINGS IMPLICATE DNA METHYLATION AS A MECHANISM BY WHICH PRENATAL STRESS ALTERS HSD11B2 GENE EXPRESSION. THESE FINDINGS HIGHLIGHT THE TISSUE SPECIFICITY OF EPIGENETIC EFFECTS, BUT ALSO RAISE THE INTRIGUING POSSIBILITY OF USING THE EPIGENETIC STATUS OF PLACENTA TO PREDICT CORRESPONDING CHANGES IN THE BRAIN. 2012 19 4011 28 LOW PATERNAL DIETARY FOLATE ALTERS THE MOUSE SPERM EPIGENOME AND IS ASSOCIATED WITH NEGATIVE PREGNANCY OUTCOMES. EPIDEMIOLOGICAL STUDIES SUGGEST THAT A FATHER'S DIET CAN INFLUENCE OFFSPRING HEALTH. A PROPOSED MECHANISM FOR PATERNAL TRANSMISSION OF ENVIRONMENTAL INFORMATION IS VIA THE SPERM EPIGENOME. THE EPIGENOME INCLUDES HERITABLE INFORMATION SUCH AS DNA METHYLATION. WE HYPOTHESIZE THAT THE DIETARY SUPPLY OF METHYL DONORS WILL ALTER EPIGENETIC REPROGRAMMING IN SPERM. HERE WE FEED MALE MICE EITHER A FOLATE-DEFICIENT OR FOLATE-SUFFICIENT DIET THROUGHOUT LIFE. PATERNAL FOLATE DEFICIENCY IS ASSOCIATED WITH INCREASED BIRTH DEFECTS IN THE OFFSPRING, WHICH INCLUDE CRANIOFACIAL AND MUSCULOSKELETAL MALFORMATIONS. GENOME-WIDE DNA METHYLATION ANALYSIS AND THE SUBSEQUENT FUNCTIONAL ANALYSIS IDENTIFY DIFFERENTIAL METHYLATION IN SPERM OF GENES IMPLICATED IN DEVELOPMENT, CHRONIC DISEASES SUCH AS CANCER, DIABETES, AUTISM AND SCHIZOPHRENIA. WHILE >300 GENES ARE DIFFERENTIALLY EXPRESSED IN OFFSPRING PLACENTA, ONLY TWO CORRESPOND TO GENES WITH DIFFERENTIAL METHYLATION IN SPERM. THIS MODEL SUGGESTS EPIGENETIC TRANSMISSION MAY INVOLVE SPERM HISTONE H3 METHYLATION OR DNA METHYLATION AND THAT ADEQUATE PATERNAL DIETARY FOLATE IS ESSENTIAL FOR OFFSPRING HEALTH. 2013 20 477 37 ARSENIC PROJECTS IN SE ASIA. EARLY LIFE EXPOSURE TO INORGANIC ARSENIC IS ASSOCIATED WITH A WIDE RANGE OF MALIGNANT AND CHRONIC DISEASE OUTCOMES IN HUMANS. PRENATAL ARSENIC EXPOSURE MAY GIVE RISE TO ADVERSE EFFECTS ON CHILD HEALTH AND DEVELOPMENT AS ARSENIC READILY PASSES THROUGH THE PLACENTA IN HUMAN BEINGS. THE IMPACT OF MATERNAL ARSENIC EXPOSURE ON FETAL GENE EXPRESSION WAS CONDUCTED IN PREGNANT WOMEN LIVING IN SOUTHERN THAILAND. ARSENIC EXPOSED NEWBORNS HAD SIGNIFICANTLY HIGHER LEVELS OF ARSENIC IN CORD BLOOD, AND A SET OF GENES ASSOCIATED WITH NUMEROUS BIOLOGICAL PATHWAYS, INCLUDING CELL SIGNALING, APOPTOSIS, INFLAMMATORY AND STRESS RESPONSE. A SLIGHT INCREASE IN PROMOTER METHYLATION OF P53 IN CORD BLOOD LYMPHOCYTES WHICH CORRELATED WITH ARSENIC ACCUMULATION IN NAILS WAS OBSERVED IN THESE EXPOSED NEWBORNS. A FOLLOW-UP STUDY ON THESE EXPOSED CHILDREN SHOWED A SIGNIFICANT INCREASE IN OXIDATIVE DNA DAMAGE, MEASURED AS 8-HYDROXYDEOXYGUANOSINE (8-OHDG) IN SALIVA. IN ADDITION, LEVELS OF URINARY 8-OHDG EXCRETION AND SALIVARY HOGG1 EXPRESSION WERE SIGNIFICANTLY DECREASED IN EXPOSED CHILDREN SUGGESTING A DEFECT IN REPAIR OF 8-OHDG IN ARSENIC-EXPOSED CHILDREN. OUR STUDY INDICATES THAT PRENATAL ARSENIC AND CONTINUED EXPOSURE THROUGH EARLY CHILDHOOD CAN TRIGGER VARIOUS GENETIC AND EPIGENETIC ALTERATIONS THAT MAY LEAD TO DISEASE DEVELOPMENT LATER IN LIFE. 2016