1 249 133 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 2 5166 42 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 3 1503 35 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 4 4085 36 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 5 1520 41 DNA METHYLATION AT DIFFERENTIALLY METHYLATED REGIONS OF IMPRINTED GENES IS RESISTANT TO DEVELOPMENTAL PROGRAMMING BY MATERNAL NUTRITION. THE NUTRITIONAL ENVIRONMENT IN WHICH THE MAMMALIAN FETUS OR INFANT DEVELOP IS RECOGNIZED AS INFLUENCING THE RISK OF CHRONIC DISEASES, SUCH AS TYPE 2 DIABETES AND HYPERTENSION, IN A PHENOMENON THAT HAS BECOME KNOWN AS DEVELOPMENTAL PROGRAMMING. THE LATE ONSET OF SUCH DISEASES IN RESPONSE TO EARLIER TRANSIENT EXPERIENCES HAS LED TO THE SUGGESTION THAT DEVELOPMENTAL PROGRAMMING MAY HAVE AN EPIGENETIC COMPONENT, BECAUSE EPIGENETIC MARKS SUCH AS DNA METHYLATION OR HISTONE TAIL MODIFICATIONS COULD PROVIDE A PERSISTENT MEMORY OF EARLIER NUTRITIONAL STATES. ONE CLASS OF GENES THAT HAS BEEN CONSIDERED A POTENTIAL TARGET OR MEDIATOR OF PROGRAMMING EVENTS IS IMPRINTED GENES, BECAUSE THESE GENES CRITICALLY DEPEND UPON EPIGENETIC MODIFICATIONS FOR CORRECT EXPRESSION AND BECAUSE MANY IMPRINTED GENES HAVE ROLES IN CONTROLLING FETAL GROWTH AS WELL AS NEONATAL AND ADULT METABOLISM. IN THIS STUDY, WE HAVE USED AN ESTABLISHED MODEL OF DEVELOPMENTAL PROGRAMMING-ISOCALORIC PROTEIN RESTRICTION TO FEMALE MICE DURING GESTATION OR LACTATION-TO EXAMINE WHETHER THERE ARE EFFECTS ON EXPRESSION AND DNA METHYLATION OF IMPRINTED GENES IN THE OFFSPRING. WE FIND THAT ALTHOUGH EXPRESSION OF SOME IMPRINTED GENES IN LIVER OF OFFSPRING IS ROBUSTLY AND SUSTAINABLY CHANGED, METHYLATION OF THE DIFFERENTIALLY METHYLATED REGIONS (DMRS) THAT CONTROL THEIR MONOALLELIC EXPRESSION REMAINS LARGELY UNALTERED. WE CONCLUDE THAT DEREGULATION OF IMPRINTING THROUGH A GENERAL EFFECT ON DMR METHYLATION IS UNLIKELY TO BE A COMMON FACTOR IN DEVELOPMENTAL PROGRAMMING. 2012 6 2472 32 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 7 5294 37 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 8 1439 31 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 9 904 44 CHRONIC EXPOSURE TO CADMIUM INDUCES DIFFERENTIAL METHYLATION IN MICE SPERMATOZOA. CADMIUM EXPOSURE IS UBIQUITOUS AND HAS BEEN LINKED TO DISEASES INCLUDING CANCERS AND REPRODUCTIVE DEFECTS. SINCE CADMIUM IS NONMUTAGENIC, IT IS THOUGHT TO EXERT ITS GENE DYSREGULATORY EFFECTS THROUGH EPIGENETIC REPROGRAMMING. SEVERAL STUDIES HAVE IMPLICATED GERMLINE EXPOSURE TO CADMIUM IN DEVELOPMENTAL REPROGRAMMING. HOWEVER, MOST OF THESE STUDIES HAVE FOCUSED ON MATERNAL EXPOSURE, WHILE THE IMPACT ON SPERM FERTILITY AND DISEASE SUSCEPTIBILITY HAS RECEIVED LESS ATTENTION. IN THIS STUDY, WE USED REDUCED REPRESENTATION BISULFITE SEQUENCING TO COMPREHENSIVELY INVESTIGATE THE IMPACT OF CHRONIC CADMIUM EXPOSURE ON MOUSE SPERMATOZOA DNA METHYLATION. ADULT MALE C57BL/J6 MICE WERE PROVIDED WATER WITH OR WITHOUT CADMIUM CHLORIDE FOR 9 WEEKS. SPERM, TESTES, LIVER, AND KIDNEY TISSUES WERE COLLECTED AT THE END OF THE TREATMENT PERIOD. CADMIUM EXPOSURE WAS CONFIRMED THROUGH GENE EXPRESSION ANALYSIS OF METALLOTHIONEIN-1 AND 2, 2 WELL-KNOWN CADMIUM-INDUCED GENES. ANALYSIS OF SPERM DNA METHYLATION CHANGES REVEALED 1788 DIFFERENTIALLY METHYLATED SITES PRESENT AT REGULATORY REGIONS IN SPERM OF MICE EXPOSED TO CADMIUM COMPARED WITH VEHICLE (CONTROL) MICE. FURTHERMORE, MOST OF THESE DIFFERENTIAL METHYLATION CHANGES POSITIVELY CORRELATED WITH CHANGES IN GENE EXPRESSION AT BOTH THE TRANSCRIPTION INITIATION STAGE AS WELL AS THE SPLICING LEVELS. INTERESTINGLY, THE GENES TARGETED BY CADMIUM EXPOSURE ARE INVOLVED IN SEVERAL CRITICAL DEVELOPMENTAL PROCESSES. OUR RESULTS PRESENT A COMPREHENSIVE ANALYSIS OF THE SPERM METHYLOME IN RESPONSE TO CHRONIC CADMIUM EXPOSURE. THESE DATA, THEREFORE, HIGHLIGHT A FOUNDATIONAL FRAMEWORK TO STUDY GENE EXPRESSION PATTERNS THAT MAY AFFECT FERTILITY IN THE EXPOSED INDIVIDUAL AS WELL AS THEIR OFFSPRING, THROUGH PATERNAL INHERITANCE. 2021 10 5661 30 SEXUAL DIMORPHISM IN EPIGENOMIC RESPONSES OF STEM CELLS TO EXTREME FETAL GROWTH. EXTREME FETAL GROWTH IS ASSOCIATED WITH INCREASED SUSCEPTIBILITY TO A RANGE OF ADULT DISEASES THROUGH AN UNKNOWN MECHANISM OF CELLULAR MEMORY. WE TESTED WHETHER HERITABLE EPIGENETIC PROCESSES IN LONG-LIVED CD34(+) HAEMATOPOIETIC STEM/PROGENITOR CELLS SHOWED EVIDENCE FOR RE-PROGRAMMING ASSOCIATED WITH THE EXTREMES OF FETAL GROWTH. HERE WE SHOW THAT BOTH FETAL GROWTH RESTRICTION AND OVER-GROWTH ARE ASSOCIATED WITH GLOBAL SHIFTS TOWARDS DNA HYPERMETHYLATION, TARGETING CIS-REGULATORY ELEMENTS IN PROXIMITY TO GENES INVOLVED IN GLUCOSE HOMEOSTASIS AND STEM CELL FUNCTION. WE FIND A SEXUALLY DIMORPHIC RESPONSE; INTRAUTERINE GROWTH RESTRICTION IS ASSOCIATED WITH SUBSTANTIALLY GREATER EPIGENETIC DYSREGULATION IN MALES, WHEREAS LARGE FOR GESTATIONAL AGE GROWTH PREDOMINANTLY AFFECTS FEMALES. THE FINDINGS ARE CONSISTENT WITH EXTREME FETAL GROWTH INTERACTING WITH VARIABLE FETAL SUSCEPTIBILITY TO INFLUENCE CELLULAR AGEING AND METABOLIC CHARACTERISTICS THROUGH EPIGENETIC MECHANISMS, POTENTIALLY GENERATING BIOMARKERS THAT COULD IDENTIFY INFANTS AT HIGHER RISK FOR CHRONIC DISEASE LATER IN LIFE. 2014 11 1599 38 DNA METHYLATION SIGNATURE OF CHILDHOOD CHRONIC PHYSICAL AGGRESSION IN T CELLS OF BOTH MEN AND WOMEN. BACKGROUND: HIGH FREQUENCY OF PHYSICAL AGGRESSION IS THE CENTRAL FEATURE OF SEVERE CONDUCT DISORDER AND IS ASSOCIATED WITH A WIDE RANGE OF SOCIAL, MENTAL AND PHYSICAL HEALTH PROBLEMS. WE HAVE PREVIOUSLY TESTED THE HYPOTHESIS THAT DIFFERENTIAL DNA METHYLATION SIGNATURES IN PERIPHERAL T CELLS ARE ASSOCIATED WITH A CHRONIC AGGRESSION TRAJECTORY IN MALES. DESPITE THE FACT THAT SEX DIFFERENCES APPEAR TO PLAY A PIVOTAL ROLE IN DETERMINING THE DEVELOPMENT, MAGNITUDE AND FREQUENCY OF AGGRESSION, MOST OF PREVIOUS STUDIES FOCUSED ON MALES, SO LITTLE IS KNOWN ABOUT FEMALE CHRONIC PHYSICAL AGGRESSION. WE THEREFORE TESTED HERE WHETHER OR NOT THERE IS A SIGNATURE OF PHYSICAL AGGRESSION IN FEMALE DNA METHYLATION AND, IF THERE IS, HOW IT RELATES TO THE SIGNATURE OBSERVED IN MALES. METHODOLOGY/PRINCIPAL FINDINGS: METHYLATION PROFILES WERE CREATED USING THE METHOD OF METHYLATED DNA IMMUNOPRECIPITATION (MEDIP) FOLLOWED BY MICROARRAY HYBRIDIZATION AND STATISTICAL AND BIOINFORMATIC ANALYSES ON T CELL DNA OBTAINED FROM ADULT WOMEN WHO WERE FOUND TO BE ON A CHRONIC PHYSICAL AGGRESSION TRAJECTORY (CPA) BETWEEN 6 AND 12 YEARS OF AGE COMPARED TO WOMEN WHO FOLLOWED A NORMAL PHYSICAL AGGRESSION TRAJECTORY. WE CONFIRMED THE EXISTENCE OF A WELL-DEFINED, GENOME-WIDE SIGNATURE OF DNA METHYLATION ASSOCIATED WITH CHRONIC PHYSICAL AGGRESSION IN THE PERIPHERAL T CELLS OF ADULT FEMALES THAT INCLUDES MANY OF THE GENES SIMILARLY ASSOCIATED WITH PHYSICAL AGGRESSION IN THE SAME CELL TYPES OF ADULT MALES. CONCLUSIONS: THIS STUDY IN A SMALL NUMBER OF WOMEN PRESENTS PRELIMINARY EVIDENCE FOR A GENOME-WIDE VARIATION IN PROMOTER DNA METHYLATION THAT ASSOCIATES WITH CPA IN WOMEN THAT WARRANT LARGER STUDIES FOR FURTHER VERIFICATION. A SIGNIFICANT PROPORTION OF THESE ASSOCIATIONS WERE PREVIOUSLY OBSERVED IN MEN WITH CPA SUPPORTING THE HYPOTHESIS THAT THE EPIGENETIC SIGNATURE OF EARLY LIFE AGGRESSION IN FEMALES IS COMPOSED OF A COMPONENT SPECIFIC TO FEMALES AND ANOTHER COMMON TO BOTH MALES AND FEMALES. 2014 12 4767 34 NUCLEAR AND MITOCHONDRIAL DNA ALTERATIONS IN NEWBORNS WITH PRENATAL EXPOSURE TO CIGARETTE SMOKE. NEWBORNS EXPOSED TO MATERNAL CIGARETTE SMOKE (CS) IN UTERO HAVE AN INCREASED RISK OF DEVELOPING CHRONIC DISEASES, CANCER, AND ACQUIRING DECREASED COGNITIVE FUNCTION IN ADULTHOOD. ALTHOUGH THE LITERATURE REPORTS MANY DELETERIOUS EFFECTS ASSOCIATED WITH MATERNAL CIGARETTE SMOKING ON THE FETUS, THE MOLECULAR ALTERATIONS AND MECHANISMS OF ACTION ARE NOT YET CLEAR. SMOKING MAY ACT DIRECTLY ON NUCLEAR DNA BY INDUCING MUTATIONS OR EPIGENETIC MODIFICATIONS. RECENT STUDIES ALSO INDICATE THAT SMOKING MAY ACT ON MITOCHONDRIAL DNA BY INDUCING A CHANGE IN THE NUMBER OF COPIES TO MAKE UP FOR THE DAMAGE CAUSED BY SMOKING ON THE RESPIRATORY CHAIN AND LACK OF ENERGY. IN ADDITION, INDIVIDUAL GENETIC SUSCEPTIBILITY PLAYS A SIGNIFICANT ROLE IN DETERMINING THE EFFECTS OF SMOKING DURING DEVELOPMENT. FURTHERMORE, PRIOR EXPOSURE OF PATERNAL AND MATERNAL GAMETES TO CIGARETTE SMOKE MAY AFFECT THE HEALTH OF THE DEVELOPING INDIVIDUAL, NOT ONLY THE IN UTERO EXPOSURE. THIS REVIEW EXAMINES THE GENETIC AND EPIGENETIC ALTERATIONS IN NUCLEAR AND MITOCHONDRIAL DNA ASSOCIATED WITH SMOKE EXPOSURE DURING THE MOST SENSITIVE PERIODS OF DEVELOPMENT (PRIOR TO CONCEPTION, PRENATAL AND EARLY POSTNATAL) AND ASSESSES HOW SUCH CHANGES MAY HAVE CONSEQUENCES FOR BOTH FETAL GROWTH AND DEVELOPMENT. 2015 13 1583 33 DNA METHYLATION PROFILES OF BLOOD CELLS ARE DISTINCT BETWEEN EARLY-ONSET OBESE AND CONTROL INDIVIDUALS. OBESITY IS A HIGHLY PREVALENT, CHRONIC DISORDER THAT HAS BEEN INCREASING IN INCIDENCE IN YOUNG PATIENTS. BOTH EPIGENETIC AND GENETIC ABERRATIONS MAY PLAY A ROLE IN THE PATHOGENESIS OF OBESITY. THEREFORE, IN-DEPTH EPIGENOMIC AND GENOMIC ANALYSES WILL ADVANCE OUR UNDERSTANDING OF THE DETAILED MOLECULAR MECHANISMS UNDERLYING OBESITY AND AID IN THE SELECTION OF POTENTIAL BIOMARKERS FOR OBESITY IN YOUTH. HERE, WE PERFORMED MICROARRAY-BASED DNA METHYLATION AND GENE EXPRESSION PROFILING OF PERIPHERAL WHITE BLOOD CELLS OBTAINED FROM SIX YOUNG, OBESE INDIVIDUALS AND SIX HEALTHY CONTROLS. WE OBSERVED THAT THE HIERARCHICAL CLUSTERING OF DNA METHYLATION, BUT NOT GENE EXPRESSION, CLEARLY SEGREGATES THE OBESE INDIVIDUALS FROM THE CONTROLS, SUGGESTING THAT THE METABOLIC DISTURBANCE THAT OCCURS AS A RESULT OF OBESITY AT A YOUNG AGE MAY AFFECT THE DNA METHYLATION OF PERIPHERAL BLOOD CELLS WITHOUT ACCOMPANYING TRANSCRIPTIONAL CHANGES. TO EXAMINE THE GENOME-WIDE DIFFERENCES IN THE DNA METHYLATION PROFILES OF YOUNG OBESE AND CONTROL INDIVIDUALS, WE IDENTIFIED DIFFERENTIALLY METHYLATED CPG SITES AND INVESTIGATED THEIR GENOMIC AND EPIGENOMIC CONTEXTS. THE ABERRANT DNA METHYLATION PATTERNS IN OBESE INDIVIDUALS CAN BE SUMMARIZED AS RELATIVE GAINS AND LOSSES OF DNA METHYLATION IN GENE PROMOTERS AND GENE BODIES, RESPECTIVELY. WE ALSO OBSERVED THAT THE CPG ISLANDS OF OBESE INDIVIDUALS ARE MORE SUSCEPTIBLE TO DNA METHYLATION COMPARED TO CONTROLS. OUR PILOT STUDY SUGGESTS THAT THE GENOME-WIDE ABERRANT DNA METHYLATION PATTERNS OF OBESE INDIVIDUALS MAY ADVANCE NOT ONLY OUR UNDERSTANDING OF THE EPIGENOMIC PATHOGENESIS BUT ALSO EARLY SCREENING OF OBESITY IN YOUTH. 2017 14 5397 34 REDUCED LEVELS OF MIRNAS 449 AND 34 IN SPERM OF MICE AND MEN EXPOSED TO EARLY LIFE STRESS. EXPOSURE OF MALE MICE TO EARLY LIFE STRESS ALTERS THE LEVELS OF SPECIFIC SPERM MIRNAS THAT PROMOTE STRESS-ASSOCIATED BEHAVIORS IN THEIR OFFSPRING. TO BEGIN TO EVALUATE WHETHER SIMILAR PHENOMENA OCCUR IN MEN, WE SEARCHED FOR SPERM MIRNA CHANGES THAT OCCUR IN BOTH MICE AND MEN EXPOSED TO EARLY LIFE STRESSORS THAT HAVE LONG-LASTING EFFECTS. FOR MEN, WE USED THE ADVERSE CHILDHOOD EXPERIENCE (ACE) QUESTIONNAIRE. IT REVEALS THE DEGREE OF ABUSIVE AND/OR DYSFUNCTIONAL FAMILY EXPERIENCES WHEN YOUNG, WHICH INCREASES RISKS OF DEVELOPING FUTURE PSYCHOLOGICAL AND PHYSICAL DISORDERS. FOR MALE MICE, WE USED ADOLESCENT CHRONIC SOCIAL INSTABILITY (CSI) STRESS, WHICH NOT ONLY ENHANCES SOCIABILITY DEFECTS FOR >1 YEAR, BUT ALSO ANXIETY AND DEFECTIVE SOCIABILITY IN FEMALE OFFSPRING FOR MULTIPLE GENERATIONS THROUGH THE MALE LINEAGE. HERE WE FOUND A STATISTICALLY SIGNIFICANT INVERSE CORRELATION BETWEEN LEVELS OF MULTIPLE MIRNAS OF THE MIR-449/34 FAMILY AND ACE SCORES OF CAUCASIAN MALES. REMARKABLY, WE FOUND MEMBERS OF THE SAME SPERM MIRNA FAMILY ARE ALSO REDUCED IN MICE EXPOSED TO CSI STRESS. THUS, FUTURE STUDIES SHOULD BE DESIGNED TO DIRECTLY TEST WHETHER REDUCED LEVELS OF THESE MIRNAS COULD BE USED AS UNBIASED INDICATORS OF CURRENT AND/OR EARLY LIFE EXPOSURE TO SEVERE STRESS. MOREOVER, AFTER MATING STRESSED MALE MICE, THESE SPERM MIRNA REDUCTIONS PERSIST IN BOTH EARLY EMBRYOS THROUGH AT LEAST THE MORULA STAGE AND IN SPERM OF MALES DERIVED FROM THEM, SUGGESTING THESE MIRNA CHANGES CONTRIBUTE TO TRANSMISSION OF STRESS PHENOTYPES ACROSS GENERATIONS. SINCE OFFSPRING OF MEN EXPOSED TO EARLY LIFE TRAUMA HAVE ELEVATED RISKS FOR PSYCHOLOGICAL DISORDERS, THESE FINDINGS RAISE THE POSSIBILITY THAT A PORTION OF THIS RISK MAY BE DERIVED FROM EPIGENETIC REGULATION OF THESE SPERM MIRNAS. 2018 15 4093 34 MATERNAL SEPARATION FOLLOWED BY CHRONIC MILD STRESS IN ADULTHOOD IS ASSOCIATED WITH CONCERTED EPIGENETIC REGULATION OF AP-1 COMPLEX GENES. DEPRESSION IS ONE OF THE MOST PREVALENT MENTAL DISEASES WORLDWIDE. PATIENTS WITH PSYCHIATRIC DISEASES OFTEN HAVE A HISTORY OF CHILDHOOD NEGLECT, INDICATING THAT EARLY-LIFE EXPERIENCES PREDISPOSE TO PSYCHIATRIC DISEASES IN ADULTHOOD. TWO STRONG MODELS WERE USED IN THE PRESENT STUDY: THE MATERNAL SEPARATION/EARLY DEPRIVATION MODEL (MS) AND THE CHRONIC MILD STRESS MODEL (CMS). IN BOTH MODELS, WE FOUND CHANGES IN THE EXPRESSION OF A NUMBER OF GENES SUCH AS CREB AND NPY. STRIKINGLY, THERE WAS A CLEAR REGULATION OF EXPRESSION OF FOUR GENES INVOLVED IN THE AP-1 COMPLEX: C-FOS, C-JUN, FOSB, AND JUN-B. INTERESTINGLY, DIFFERENT EXPRESSION LEVELS WERE OBSERVED DEPENDING ON THE MODEL, WHEREAS THE COMBINATION OF THE MODELS RESULTED IN A NORMAL LEVEL OF GENE EXPRESSION. THE EFFECTS OF MS AND CMS ON GENE EXPRESSION WERE ASSOCIATED WITH DISTINCT HISTONE METHYLATION/ACETYLATION PATTERNS OF ALL FOUR GENES. THE EPIGENETIC CHANGES, LIKE GENE EXPRESSION, WERE ALSO DEPENDENT ON THE SPECIFIC STRESSOR OR THEIR COMBINATION. THE OBTAINED RESULTS SUGGEST THAT SINGLE LIFE EVENTS LEAVE A MARK ON GENE EXPRESSION AND THE EPIGENETIC SIGNATURE OF GENE PROMOTERS, BUT A COMBINATION OF DIFFERENT STRESSORS AT DIFFERENT LIFE STAGES CAN FURTHER CHANGE GENE EXPRESSION THROUGH EPIGENETIC FACTORS, POSSIBLY CAUSING THE LONG-LASTING ADVERSE EFFECTS OF STRESS. 2021 16 2158 46 EPIGENETIC MECHANISMS FOR NUTRITION DETERMINANTS OF LATER HEALTH OUTCOMES. EPIGENETIC MARKING ON GENES CAN DETERMINE WHETHER OR NOT GENES ARE EXPRESSED. EPIGENETIC REGULATION IS MEDIATED BY THE ADDITION OF METHYL GROUPS TO DNA CYTOSINE BASES, OF METHYL AND ACETYL GROUPS TO PROTEINS (HISTONES) AROUND WHICH DNA IS WRAPPED, AND BY SMALL INTERFERING RNA MOLECULES. SOME COMPONENTS OF EPIGENETIC REGULATION HAVE EVOLVED TO PERMIT CONTROL OF WHETHER MATERNAL OR PATERNAL GENES ARE EXPRESSED. THE EPIGENETIC IMPRINTING OF IGF2 EXPRESSION IS AN EXAMPLE OF MATERNAL AND PATERNAL EPIGENETIC MARKING THAT MODULATES FETAL GROWTH AND FETAL SIZE. HOWEVER, EPIGENETIC REGULATION ALSO PERMITS THE FETUS AND THE INFANT TO ADAPT GENE EXPRESSION TO THE ENVIRONMENT IN WHICH IT IS GROWING; SOMETIMES WHEN THIS ADJUSTMENT GOES AWRY, THE RISK OF CHRONIC DISEASE IS INCREASED. RECENT PROGRESS IN THE UNDERSTANDING OF NUTRITIONAL INFLUENCES ON EPIGENETICS SUGGESTS THAT NUTRIENTS THAT ARE PART OF METHYL-GROUP METABOLISM CAN SIGNIFICANTLY INFLUENCE EPIGENETICS. DURING CRITICAL PERIODS IN DEVELOPMENT, DIETARY METHYL-GROUP INTAKE (CHOLINE, METHIONINE, AND FOLATE) CAN ALTER DNA AND HISTONE METHYLATION, WHICH RESULTS IN LIFELONG CHANGES IN GENE EXPRESSION. IN RODENT MODELS, PREGNANT DAMS THAT WERE FED DIETS HIGH IN METHIONINE, FOLIC ACID, AND CHOLINE PRODUCED OFFSPRING WITH DIFFERENT COAT COLORS OR WITH KINKED TAILS. A NUMBER OF SYNDROMES IN HUMANS CAN BE CAUSED BY DEFECTIVE EPIGENETIC REGULATION, INCLUDING RETT SYNDROME. THERE ARE INTERESTING EXAMPLES OF THE EFFECTS OF NUTRITION IN EARLY LIFE THAT RESULT IN ALTERED HEALTH IN ADULTS, AND SOME OF THESE COULD BE THE RESULT OF ALTERED EPIGENETIC REGULATION OF GENE EXPRESSION. 2009 17 990 33 CHRONIC SOCIAL STRESS INDUCES DNA METHYLATION CHANGES AT AN EVOLUTIONARY CONSERVED INTERGENIC REGION IN CHROMOSOME X. CHRONIC STRESS RESULTING FROM PROLONGED EXPOSURE TO NEGATIVE LIFE EVENTS INCREASES THE RISK OF MOOD AND ANXIETY DISORDERS. ALTHOUGH CHRONIC STRESS CAN CHANGE GENE EXPRESSION RELEVANT FOR BEHAVIOR, MOLECULAR REGULATORS OF THIS CHANGE HAVE NOT BEEN FULLY DETERMINED. ONE PROCESS THAT COULD PLAY A ROLE IS DNA METHYLATION, AN EPIGENETIC PROCESS WHEREBY A METHYL GROUP IS ADDED ONTO NUCLEOTIDES, PREDOMINANTLY CYTOSINE IN THE CPG CONTEXT, AND WHICH CAN BE INDUCED BY CHRONIC STRESS. IT IS UNKNOWN TO WHAT EXTENT CHRONIC SOCIAL DEFEAT, A MODEL OF HUMAN SOCIAL STRESS, INFLUENCES DNA METHYLATION PATTERNS ACROSS THE GENOME. OUR STUDY ADDRESSED THIS QUESTION BY USING A TARGETED-CAPTURE APPROACH CALLED METHYL-SEQ TO INVESTIGATE DNA METHYLATION PATTERNS OF THE DENTATE GYRUS AT PUTATIVE REGULATORY REGIONS ACROSS THE MOUSE GENOME FROM MICE EXPOSED TO 14 DAYS OF SOCIAL DEFEAT. FINDINGS WERE REPLICATED IN INDEPENDENT COHORTS BY BISULFITE-PYROSEQUENCING. TWO DIFFERENTIALLY METHYLATED REGIONS (DMRS) WERE IDENTIFIED. ONE DMR WAS LOCATED AT INTRON 9 OF DROSHA, AND IT SHOWED REDUCED METHYLATION IN STRESSED MICE. THIS OBSERVATION REPLICATED IN ONE OF TWO INDEPENDENT COHORTS. A SECOND DMR WAS IDENTIFIED AT AN INTERGENIC REGION OF CHROMOSOME X, AND METHYLATION IN THIS REGION WAS INCREASED IN STRESSED MICE. THIS METHYLATION DIFFERENCE REPLICATED IN TWO INDEPENDENT COHORTS AND IN MAJOR DEPRESSIVE DISORDER (MDD) POSTMORTEM BRAINS. THESE RESULTS HIGHLIGHT A REGION NOT PREVIOUSLY KNOWN TO BE DIFFERENTIALLY METHYLATED BY CHRONIC SOCIAL DEFEAT STRESS AND WHICH MAY BE INVOLVED IN MDD. 2018 18 287 28 AGING AND CHRONIC SUN EXPOSURE CAUSE DISTINCT EPIGENETIC CHANGES IN HUMAN SKIN. EPIGENETIC CHANGES ARE WIDELY CONSIDERED TO PLAY AN IMPORTANT ROLE IN AGING, BUT EXPERIMENTAL EVIDENCE TO SUPPORT THIS HYPOTHESIS HAS BEEN SCARCE. WE HAVE USED ARRAY-BASED ANALYSIS TO DETERMINE GENOME-SCALE DNA METHYLATION PATTERNS FROM HUMAN SKIN SAMPLES AND TO INVESTIGATE THE EFFECTS OF AGING, CHRONIC SUN EXPOSURE, AND TISSUE VARIATION. OUR RESULTS REVEAL A HIGH DEGREE OF TISSUE SPECIFICITY IN THE METHYLATION PATTERNS AND ALSO SHOWED VERY LITTLE INTERINDIVIDUAL VARIATION WITHIN TISSUES. DATA STRATIFICATION BY AGE REVEALED THAT DNA FROM OLDER INDIVIDUALS WAS CHARACTERIZED BY A SPECIFIC HYPERMETHYLATION PATTERN AFFECTING LESS THAN 1% OF THE MARKERS ANALYZED. INTERESTINGLY, STRATIFICATION BY SUN EXPOSURE PRODUCED A FUNDAMENTALLY DIFFERENT PATTERN WITH A SIGNIFICANT TREND TOWARDS HYPOMETHYLATION. OUR RESULTS THUS IDENTIFY DEFINED AGE-RELATED DNA METHYLATION CHANGES AND SUGGEST THAT THESE ALTERATIONS MIGHT CONTRIBUTE TO THE PHENOTYPIC CHANGES ASSOCIATED WITH SKIN AGING. 2010 19 5193 35 PRENATAL EXPOSURE TO ENVIRONMENTAL PRO-OXIDANTS INDUCES MITOCHONDRIA-MEDIATED EPIGENETIC CHANGES: A CROSS-SECTIONAL PILOT STUDY. MITOCHONDRIA PLAY A CENTRAL ROLE IN MAINTAINING CELLULAR AND METABOLIC HOMEOSTASIS DURING VITAL DEVELOPMENT CYCLES OF FOETAL GROWTH. OPTIMAL MITOCHONDRIAL FUNCTIONS ARE IMPORTANT NOT ONLY TO SUSTAIN ADEQUATE ENERGY PRODUCTION BUT ALSO FOR REGULATED EPIGENETIC PROGRAMMING. HOWEVER, THESE ORGANELLES ARE SUBTLE TARGETS OF ENVIRONMENTAL EXPOSURES, AND ANY PERTURBANCE IN THE DEFINED MITOCHONDRIAL MACHINERY DURING THE DEVELOPMENTAL STAGE CAN LEAD TO THE RE-PROGRAMMING OF THE FOETAL EPIGENETIC LANDSCAPE. AS THESE MODIFICATIONS CAN BE TRANSFERRED TO SUBSEQUENT GENERATIONS, WE HEREIN PERFORMED A CROSS-SECTIONAL STUDY TO HAVE AN IN-DEPTH UNDERSTANDING OF THIS INTRICATE PHENOMENON. THE STUDY WAS CONDUCTED WITH TWO ARMS: WHEREAS THE FIRST GROUP CONSISTED OF IN UTERO PRO-OXIDANT EXPOSED INDIVIDUALS AND THE SECOND GROUP INCLUDED CONTROLS. OUR RESULTS SHOWED HIGHER LEVELS OF OXIDATIVE MTDNA DAMAGE AND ASSOCIATED INTEGRATED STRESS RESPONSE AMONG THE EXPOSED INDIVIDUALS. THESE DISTURBANCES WERE FOUND TO BE CLOSELY RELATED TO THE OBSERVED DISCREPANCIES IN MITOCHONDRIAL BIOGENESIS. THE EXPOSED GROUP SHOWED MTDNA HYPERMETHYLATION AND CHANGES IN ALLIED MITOCHONDRIAL FUNCTIONING. ALTERED EXPRESSION OF MITOMIRS AND THEIR RESPECTIVE TARGET GENES IN THE EXPOSED GROUP INDICATED THE POSSIBILITIES OF A DISTURBED MITOCHONDRIAL-NUCLEAR CROSS TALK. THIS WAS FURTHER CONFIRMED BY THE MODIFIED ACTIVITY OF THE MITOCHONDRIAL STRESS REGULATORS AND PRO-INFLAMMATORY MEDIATORS AMONG THE EXPOSED GROUP. IMPORTANTLY, THE DISTURBED DNMT FUNCTIONING, HYPERMETHYLATION OF NUCLEAR DNA, AND HIGHER DEGREE OF POST-TRANSLATIONAL HISTONE MODIFICATIONS ESTABLISHED THE EXISTENCE OF ABERRANT EPIGENETIC MODIFICATIONS IN THE EXPOSED INDIVIDUALS. OVERALL, OUR RESULTS DEMONSTRATE THE FIRST MOLECULAR INSIGHTS OF IN UTERO PRO-OXIDANT EXPOSURE ASSOCIATED CHANGES IN THE MITOCHONDRIAL-EPIGENETIC AXIS. ALTHOUGH, OUR STUDY MIGHT NOT CEMENT AN EXPOSURE-RESPONSE RELATIONSHIP FOR ANY PARTICULAR ENVIRONMENTAL PRO-OXIDANT, BUT SUFFICE TO ESTABLISH A DOGMA OF MITO-EPIGENETIC REPROGRAMMING AT INTRAUTERINE MILIEU WITH CHRONIC ILLNESS, A HITHERTO UNREPORTED INTERACTION. 2022 20 3042 41 GENOME-WIDE ALTERATION OF HISTONE METHYLATION PROFILES ASSOCIATED WITH COGNITIVE CHANGES IN RESPONSE TO DEVELOPMENTAL ARSENIC EXPOSURE IN MICE. INORGANIC ARSENIC IS A XENOBIOTIC ENTERING THE BODY PRIMARILY THROUGH CONTAMINATED DRINKING WATER AND FOOD. THERE ARE DEFINED MECHANISMS THAT DESCRIBE ARSENIC'S ASSOCIATION WITH INCREASED CANCER INCIDENCE, HOWEVER MECHANISMS EXPLAINING ARSENIC EXPOSURE AND NEURODEVELOPMENTAL OR AGING DISORDERS ARE POORLY DEFINED. IN RECENT YEARS, ARSENIC EFFECTS ON EPIGENOME HAVE BECOME A PARTICULAR FOCUS. WE HYPOTHESIZE THAT HUMAN RELEVANT ARSENIC EXPOSURE DURING PARTICULAR DEVELOPMENTAL WINDOWS, OR LONG-TERM EXPOSURE LATER IN LIFE INDUCE PATHOPHYSIOLOGICAL NEURAL CHANGES THROUGH EPIGENOMIC ALTERATIONS, IN PARTICULAR HISTONE METHYLATION PROFILE, MANIFESTING AS COGNITIVE DECLINE. C57BL/6 WILD-TYPE MICE WERE CONTINUALLY EXPOSED TO SODIUM ARSENITE (100 MICROG/L) IN DRINKING WATER PRIOR TO MATING THROUGH WEANING OF THE EXPERIMENTAL PROGENY. A SECOND COHORT OF AGED APP/PS MICE WERE CHRONICALLY EXPOSED TO THE SAME LEVEL OF ARSENIC. COGNITIVE TESTING, HISTOLOGICAL EXAMINATION OF BRAINS AND GENOME-WIDE METHYLATION LEVELS OF H3K4ME3 AND H3K27ME3 EXAMINED AFTER CHIP-SEQ WERE USED TO DETERMINE THE EFFECTS OF ARSENIC EXPOSURE. DEVELOPMENTAL ARSENIC EXPOSURE CAUSED SIGNIFICANTLY DIMINISHED COGNITION IN WILD-TYPE MICE. THE ANALYSIS OF CHIP-SEQ DATA AND EXPERIMENTS WITH MOUSE EMBRYONIC STEM CELLS DEMONSTRATED THAT EPIGENETIC CHANGES INDUCED BY ARSENIC EXPOSURE TRANSLATED INTO GENE EXPRESSION ALTERATIONS ASSOCIATED WITH NEURONAL DEVELOPMENT AND NEUROLOGICAL DISEASE. INCREASED HIPPOCAMPAL AMYLOID PLAQUES LEVELS OF APP/PS MICE AND COGNITIVE DECLINE PROVIDED EVIDENCE THAT ARSENIC EXPOSURE AGGRAVATED AN EXISTING ALZHEIMER'S DISEASE-LIKE PHENOTYPE. WE SHOW DEVELOPMENTAL ARSENIC EXPOSURE SIGNIFICANTLY IMPACTS HISTONE MODIFICATIONS IN BRAIN WHICH REMAIN PRESENT INTO ADULTHOOD AND PROVIDE A POTENTIAL MECHANISM BY WHICH DEVELOPMENTAL ARSENIC EXPOSURE INFLUENCES COGNITIVE FUNCTIONS. WE ALSO SHOW THAT HUMAN RELEVANT, CHRONIC ARSENIC EXPOSURE HAS DELETERIOUS EFFECTS ON ADULT APP/PS MICE AND EXACERBATES EXISTING ALZHEIMER'S DISEASE-LIKE SYMPTOMS. THE RESULTS DEMONSTRATE HOW DEVELOPMENTAL ARSENIC EXPOSURE IMPACTS THE BRAIN EPIGENOME, LEADING TO ALTERED GENE EXPRESSION LATER IN LIFE. 2022