1 2101 132 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 2 5192 39 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 3 668 45 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 4 3462 41 HYPOTHALAMIC NR3C1 DNA METHYLATION IN RATS EXPOSED TO PRENATAL STRESS. BACKGROUND: HUMAN AND ANIMAL STUDIES HAVE INDICATED THAT MATERNAL PRENATAL STRESS (PS) HAS MOLECULAR AND BEHAVIORAL EFFECTS DURING PREGNANCY AND EARLY LIFE. THE PRESENT STUDY AIMED TO EVALUATE THE EPIGENETIC CHANGES OF THE NR3C1 GENE INVOLVED IN THE HPA AXIS IN THE HYPOTHALAMIC TISSUES OF RATS EXPOSED TO PS INDUCED BY CHRONIC UNPREDICTABLE MILD STRESS (CUMS). BEHAVIORAL AND MOLECULAR EFFECTS OF THESE CHANGES ON THE NEXT GENERATION WERE ALSO ASSESSED. METHODS AND RESULTS: CUMS PROTOCOL WAS USED TO GENERATE STRESS IN PREGNANT WISTAR RATS. TO DETERMINE THE EFFECTS OF STRESS ON ANHEDONIA AND MOVEMENT, SUCROSE PREFERENCE TEST, FORCED SWIMMING TEST, AND OPEN FIELD TEST WERE PERFORMED. FOLLOWING THESE BEHAVIORAL EXPERIMENTS, BISULFITE SEQUENCING PCR FOR DNA METHYLATION LEVELS OF THE NR3C1 GENE, RT-QPCR FOR MRNA LEVELS, AND WESTERN BLOT TECHNIQUES FOR PROTEIN ANALYSIS WERE USED IN THE HYPOTHALAMIC TISSUE OF SACRIFICED RATS. DEPRESSION-LIKE BEHAVIORS WERE EVIDENT IN THE BEHAVIORAL TESTS OF STRESS-EXPOSED MOTHERS AND PUPS. IN PS-EXPOSED PUPS, HYPOTHALAMIC NR3C1 PROMOTER METHYLATION WAS HIGHER, AND NR3C1 MRNA LEVELS AND NR3C1 PROTEIN LEVELS WERE LOWER COMPARED WITH CONTROLS, REGARDLESS OF SEX. CONCLUSION: OUR RESULTS CONFIRM THE RELATIONSHIP BETWEEN PS AND EPIGENETIC CHANGES OF HPA AXIS-RELATED GENES AND SHOW THAT NR3C1 GENE METHYLATION STATUS IN PUPS IS SENSITIVE TO PS DURING PREGNANCY. ENVIRONMENTAL MATERNAL STRESS MAY HAVE TRANSGENERATIONAL EFFECTS THAT ARE POTENTIALLY ASSOCIATED WITH ADVERSE OUTCOMES IN THE PUPS. 2022 5 2371 48 EPIGENETIC REGULATION OF THE GLUCOCORTICOID RECEPTOR PROMOTER 1(7) IN ADULT RATS. REGULATION OF GLUCOCORTICOID RECEPTOR (GR) LEVELS IS AN IMPORTANT STRESS ADAPTATION MECHANISM. TRANSCRIPTION FACTOR NFGI-A AND ENVIRONMENTALLY INDUCED GR PROMOTER 1 7 METHYLATION HAVE BEEN IMPLICATED IN FINE-TUNING THE EXPRESSION OF GR 1 7 TRANSCRIPTS. HERE, WE INVESTIGATED GR PROMOTER 1 7 METHYLATION AND GR 1 7 EXPRESSION IN ADULT RATS EXPOSED TO EITHER ACUTE OR CHRONIC STRESS PARADIGMS. A STRONG NEGATIVE CORRELATION WAS OBSERVED BETWEEN THE SUM OF PROMOTER-WIDE METHYLATION LEVELS AND GR 1 7 TRANSCRIPT LEVELS, INDEPENDENT OF THE STRESSOR. METHYLATION OF INDIVIDUAL SITES DID NOT, HOWEVER, CORRELATE WITH TRANSCRIPT LEVELS. THIS SUGGESTED THAT PROMOTER 1 7 WAS DIRECTLY REGULATED BY PROMOTER-WIDE DNA METHYLATION. ALTHOUGH ACUTE STRESS INCREASED NGFI-A EXPRESSION IN THE HYPOTHALAMIC PARAVENTRICULAR NUCLEUS (PVN), GR 1 7 TRANSCRIPT LEVELS REMAINED UNAFFECTED DESPITE LOW METHYLATION LEVELS. ACUTE STRESS HAD LITTLE EFFECT ON THESE LOW METHYLATION LEVELS, EXCEPT AT FOUR HIPPOCAMPAL CPGS. CHRONIC STRESS ALTERED THE CORTICOSTERONE RESPONSE TO AN ACUTE STRESSOR. IN THE ADRENAL AND PITUITARY GLANDS, BUT NOT IN THE BRAIN, THIS WAS ACCOMPANIED BY AN INCREASE IN METHYLATION LEVELS IN ORCHESTRATED CLUSTERS RATHER THAN INDIVIDUAL CPGS. PVN METHYLATION LEVELS, UNAFFECTED BY ACUTE OR CHRONIC STRESS, WERE SIGNIFICANTLY MORE VARIABLE WITHIN- THAN BETWEEN-GROUPS, SUGGESTING THAT THEY WERE INSTATED PROBABLY DURING THE PERINATAL PERIOD AND REPRESENT A PRE-ESTABLISHED TRAIT. THUS, IN ADDITION TO THE KNOWN PERINATAL PROGRAMMING, THE GR 1 7 PROMOTER IS EPIGENETICALLY REGULATED BY CHRONIC STRESS IN ADULTHOOD, AND RETAINS PROMOTER-WIDE TISSUE-SPECIFIC PLASTICITY. DIFFERENCES IN METHYLATION SUSCEPTIBILITY BETWEEN THE PVN IN THE PERINATAL PERIOD AND THE PERIPHERAL HPA AXIS TISSUES IN ADULTHOOD MAY REPRESENT AN IMPORTANT "TRAIT" VS. "STATE" REGULATION OF THE GR GENE. 2012 6 5166 49 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 7 1418 49 DIFFERENCES IN DNA METHYLATION REPROGRAMMING UNDERLIE THE SEXUAL DIMORPHISM OF BEHAVIORAL DISORDER CAUSED BY PRENATAL STRESS IN RATS. PRENATAL STRESS (PS) CAN LEAD TO NEUROENDOCRINE AND EMOTIONAL DISORDERS LATER IN ADOLESCENCE. SEXUAL DIMORPHISM IN THESE NEURODEVELOPMENTAL OUTCOMES HAVE BEEN OBSERVED; HOWEVER, THE UNDERLYING MECHANISMS ARE NOT FULLY UNDERSTOOD. TO ADDRESS THIS ISSUE, WE INVESTIGATED WHETHER THERE ARE SEX DIFFERENCES IN EPIGENETIC REPROGRAMMING IN RATS EXPOSED TO PS. PREGNANT FEMALE RATS WERE SUBJECTED TO CHRONIC RESTRAINT STRESS FROM GESTATIONAL DAY (G)12 TO G18. FROM POSTNATAL DAY (P)38 TO P45, SUBGROUPS OF OFFSPRING INCLUDING BOTH MALES AND FEMALES WERE SUBJECTED TO BEHAVIORAL TESTING AND BRAIN TISSUE SPECIMENS WERE ANALYZED BY DNA PYROSEQUENCING, WESTERN BLOTTING, AND GOLGI STAINING TO ASSESS CHANGES IN METHYLATION PATTERN OF GLUCOCORTICOID RECEPTOR (GR) GENE, EXPRESSION OF DNA METHYLTRANSFERASE (DNMT) AND DNA DEMETHYLASE, AND DENDRITE MORPHOLOGY, RESPECTIVELY. THE DNA METHYLTRANSFERASE INHIBITOR DECITABINE WAS ADMINISTERED TO RATS PRIOR TO PS TO FURTHER EVALUATE THE ROLE OF METHYLATION IN THE SEXUALLY DIMORPHIC EFFECTS OF PS. THE RESULTS SHOWED THAT PS INCREASED ANXIETY-LIKE BEHAVIOR IN OFFSPRING, ESPECIALLY IN FEMALES, WHILE DEPRESSION-LIKE BEHAVIOR WAS INCREASED IN MALE OFFSPRING COMPARED TO CONTROL LITTERMATES. THE METHYLATION PATTERN IN THE PROMOTER REGION OF THE GR GENE DIFFERED BETWEEN MALES AND FEMALES. SEX-SPECIFIC CHANGES IN THE EXPRESSION OF DNMTS (DNMT1 AND DNMT3A) AND DNA DEMETHYLASE (TET METHYLCYTOSINE DIOXYGENASE 2) WERE ALSO OBSERVED. INTERESTINGLY, DECITABINE ALLEVIATED THE BEHAVIORAL DISORDER CAUSED BY PS AND RESTORED DENDRITE DENSITY AND MORPHOLOGY IN FEMALE BUT NOT MALE RATS. THESE FINDINGS SUGGEST THAT DIFFERENT CHANGE PATTERNS OF DNMT AND DEMETHYLASE IN THE TWO SEXES AFTER PS ARE RESPONSIBLE FOR THE SEXUALLY DIMORPHISM, WHICH COULD HAVE IMPLICATIONS FOR THE CLINICAL MANAGEMENT OF STRESS-RELATED DISORDERS. 2020 8 5206 48 PRENATAL STRESS INDUCES LONG-TERM BEHAVIORAL SEX-DEPENDENT CHANGES IN RATS OFFSPRING: THE ROLE OF THE HPA AXIS AND EPIGENETICS. PRECLINICAL GENETIC STUDIES HAVE RELATED STRESS EARLY EXPOSURES WITH CHANGES IN GENE REGULATORY MECHANISMS, INCLUDING EPIGENETIC ALTERATIONS, SUCH AS MODIFICATIONS OF DNA METHYLATION, HISTONE DEACETYLATION, AND HISTONES ACETYLATION. THIS STUDY EVALUATES THE EFFECTS OF PRENATAL STRESS ON THE BEHAVIOR, HYPOTHALAMUS-PITUITARY-ADRENAL (HPA)-AXIS, AND EPIGENETIC PARAMETERS IN STRESSED DAMS AND THEIR OFFSPRING. THE RATS WERE SUBJECTED TO A PROTOCOL OF CHRONIC UNPREDICTABLE MILD STRESS ON THE FOURTEENTH DAY OF PREGNANCY UNTIL THE BIRTH OF OFFSPRING. AFTER BIRTH, MATERNAL CARE WAS EVALUATED FOR SIX DAYS. FOLLOWING WEANING, THE LOCOMOTOR AND DEPRESSIVE-LIKE BEHAVIORS OF THE DAMS AND THEIR OFFSPRING (60 DAYS OLD) WERE ASSESSED. THE HPA AXIS PARAMETERS WERE EVALUATED IN SERUM FROM DAMS AND OFFSPRING, AND EPIGENETIC PARAMETERS (HISTONE ACETYLTRANSFERASE (HAT), HISTONE DEACETYLASE (HDAC), DNA METHYLTRANSFERASE (DNMT) ACTIVITIES, AND THE LEVELS OF HISTONE H3 ACETYLATED AT LYSINE RESIDUE 9 (H3K9AC) AND HISTONE 3 ACETYLATED AT LYSINE RESIDUE 14 (H3K14AC)) WERE ASSESSED IN DAMS' AND OFFSPRING' BRAINS. PRENATAL STRESS DID NOT SIGNIFICANTLY INFLUENCE MATERNAL CARE; HOWEVER, IT INDUCED MANIC BEHAVIOR IN FEMALE OFFSPRING. THESE BEHAVIORAL ALTERATIONS IN THE OFFSPRING WERE ACCOMPANIED BY HYPERACTIVITY OF THE HPA-AXIS, EPIGENETIC ADAPTATIONS IN THE ACTIVITY OF HDAC AND DNMT, AND ACETYLATION IN THE HISTONES H3K9 AND H3K14. IN ADDITION, THE PRENATAL STRESSED FEMALE OFFSPRING SHOWED INCREASED LEVELS OF ACTH COMPARED TO THEIR MALE COUNTERPART. OUR FINDINGS REINFORCE THE IMPACT OF PRENATAL STRESS ON BEHAVIOR, STRESS RESPONSE, AND EPIGENETIC PROFILE OF OFFSPRING. 2023 9 586 41 BEHAVIOURAL AND EPIGENETIC EFFECTS OF PATERNAL EXPOSURE TO CANNABINOIDS DURING ADOLESCENCE ON OFFSPRING VULNERABILITY TO STRESS. CHRONIC CANNABINOID EXPOSURE DURING ADOLESCENCE IN MALE RATS INDUCES CHRONIC COGNITIVE AND EMOTIONAL IMPAIRMENTS. HOWEVER, THE IMPACT OF THIS FORM OF EXPOSURE ON OFFSPRING VULNERABILITY TO STRESS IS UNKNOWN. THE AIM OF THIS STUDY WAS TO EVALUATE THE BEHAVIOURAL AND EPIGENETIC EFFECTS OF STRESS IN THE OFFSPRING OF MALE RATS WHOSE FATHERS WERE EXPOSED TO CANNABINOIDS DURING ADOLESCENCE. MALE ADOLESCENT OFFSPRING OF WIN55,212-2 (1.2 MG/KG) TREATED RATS WERE EXPOSED DURING ONE WEEK TO VARIABLE STRESSORS AND SUBJECTED TO BEHAVIOURAL TESTS OF ANXIETY AND EPISODIC-LIKE MEMORY, FOLLOWED BY AN ASSESSMENT OF GLOBAL DNA METHYLATION AND EXPRESSION OF DNA METHYLTRANSFERASES ENZYMES DNMT1 AND DNMT3A MRNA IN THE PREFRONTAL CORTEX. STRESS EXPOSURE INDUCED A SIGNIFICANT ANXIOGENIC-LIKE EFFECT BUT DID NOT AFFECT THE EPISODIC-LIKE MEMORY IN THE OFFSPRING OF WIN55,212-2 EXPOSED FATHERS IN COMPARISON TO THE OFFSPRING OF NON-EXPOSED FATHERS. THESE BEHAVIOURAL CHANGES WERE SUBSEQUENT TO A SIGNIFICANT INCREASE IN GLOBAL DNA METHYLATION AND DNMT1 AND DNMTA3 TRANSCRIPTION IN THE PREFRONTAL CORTEX. THESE DATA SUGGEST THAT THE DELETERIOUS EFFECT OF CHRONIC EXPOSURE TO CANNABINOIDS DURING ADOLESCENCE ARE NOT LIMITED TO THE EXPOSED INDIVIDUALS BUT MAY INCREASE THE VULNERABILITY TO STRESS-INDUCED ANXIETY IN THE OFFSPRING AND ALTER THEIR EPIGENETIC PROGRAMMING. 2019 10 2472 34 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 11 1563 40 DNA METHYLATION OF METHYLATION COMPLEX GENES IN RELATION TO STRESS AND GENOME-WIDE METHYLATION IN MOTHER-NEWBORN DYADS. OBJECTIVES: EARLY LIFE STRESS IS KNOWN TO HAVE ENDURING BIOLOGICAL EFFECTS, PARTICULARLY WITH RESPECT TO HEALTH. EPIGENETIC MODIFICATIONS, SUCH AS DNA METHYLATION, ARE A POSSIBLE MECHANISM TO MEDIATE THE BIOLOGICAL EFFECT OF STRESS. WE PREVIOUSLY FOUND CORRELATIONS BETWEEN MATERNAL STRESS, NEWBORN BIRTHWEIGHT, AND GENOME-WIDE MEASURES OF DNA METHYLATION. HERE WE INVESTIGATE TEN GENES RELATED TO THE METHYLATION/DEMETHYLATION COMPLEX IN ORDER TO BETTER UNDERSTAND THE IMPACT OF STRESS ON HEALTH. MATERIALS AND METHODS: DNA METHYLATION AND GENETIC VARIANTS AT METHYLATION/DEMETHYLATION GENES WERE ASSAYED. MEAN METHYLATION MEASURES WERE CONSTRUCTED FOR EACH GENE AND TESTED, IN ADDITION TO GENETIC VARIANTS, FOR ASSOCIATION WITH MATERNAL STRESS MEASURES BASED ON INTERVIEW AND SURVEY DATA (CHRONIC STRESS AND WAR TRAUMA), MATERNAL VENOUS, AND NEWBORN CORD GENOME-WIDE MEAN METHYLATION (GMM), AND BIRTHWEIGHT. RESULTS: AFTER CELL TYPE CORRECTION, WE FOUND MULTIPLE PAIRWISE ASSOCIATIONS BETWEEN WAR TRAUMA, MATERNAL GMM, MATERNAL METHYLATION AT DNMT1, DNMT3A, TET3, AND MBD2, AND BIRTHWEIGHT. CONCLUSIONS: THE ASSOCIATION OF MATERNAL GMM AND MATERNAL METHYLATION AT DNMT1, DNMT3A, TET3, AND MBD2 IS CONSISTENT WITH THE ROLE OF THESE GENES IN ESTABLISHING, MAINTAINING AND ALTERING GENOME-WIDE METHYLATION PATTERNS, IN SOME CASES IN RESPONSE TO STRESS. DNMT1 PRODUCES ONE OF THE PRIMARY ENZYMES THAT REPRODUCES METHYLATION PATTERNS DURING DNA REPLICATION. DNMT3A AND TET3 HAVE BEEN IMPLICATED IN GENOME-WIDE HYPOMETHYLATION IN RESPONSE TO GLUCOCORTICOID HORMONES. ALTHOUGH WE CANNOT DETERMINE THE DIRECTIONALITY OF THE GENIC AND GENOME-WIDE CHANGES IN METHYLATION, OUR RESULTS SUGGEST THAT ALTERED METHYLATION OF SPECIFIC METHYLATION GENES MAY BE PART OF THE MOLECULAR MECHANISM UNDERLYING THE HUMAN BIOLOGICAL RESPONSE TO STRESS. 2018 12 5199 45 PRENATAL MATERNAL STRESS IS ASSOCIATED WITH INCREASED SENSITIVITY TO NEUROPATHIC PAIN AND SEX-SPECIFIC CHANGES IN SUPRASPINAL MRNA EXPRESSION OF EPIGENETIC- AND STRESS-RELATED GENES IN ADULTHOOD. EXPOSURE TO PRENATAL MATERNAL STRESS IMPACTS ADULT BEHAVIORAL OUTCOMES AND HAS BEEN SUGGESTED AS A RISK FACTOR FOR CHRONIC PAIN. HOWEVER, THE NEUROBIOLOGICAL MECHANISMS IMPLICATED ARE NOT WELL-CHARACTERIZED. IN THIS STUDY, WE ANALYZED THE EFFECT OF A PRENATAL MATERNAL STRESS ON THE DEVELOPMENT OF NEUROPATHIC PAIN-RELATED BEHAVIOURS AND GENE EXPRESSION IN THE FRONTAL CORTEX AND HIPPOCAMPUS IN ADULT OFFSPRING FOLLOWING CHRONIC CONSTRICTION INJURY OF THE SCIATIC NERVE IN MALE AND FEMALE CD1 MICE. NERVE INJURY-INDUCED MECHANICAL HYPERSENSITIVITY WAS AMPLIFIED IN BOTH MALE AND FEMALE PRENATALLY-STRESSED OFFSPRING, SUGGESTING THAT PRENATAL STRESS EXACERBATES PAIN AFTER INJURY. ANALYSIS OF MRNA EXPRESSION OF GENES RELATED TO EPIGENETIC REGULATION AND STRESS RESPONSES IN THE FRONTAL CORTEX AND HIPPOCAMPUS, BRAIN STRUCTURES IMPLICATED IN CHRONIC PAIN, SHOWED DISTINCT SEX AND REGION-SPECIFIC PATTERNS OF DYSREGULATION. IN GENERAL, MRNA EXPRESSION WAS MOST FREQUENTLY ALTERED IN THE MALE HIPPOCAMPUS AND EFFECTS OF PRENATAL STRESS WERE MORE PREVALENT THAN EFFECTS OF NERVE INJURY IN BOTH SUPRASPINAL AREAS. THESE FINDINGS DEMONSTRATE THE IMPACT OF PRENATAL STRESS ON BEHAVIORAL SENSITIVITY TO A PAINFUL INJURY. CHANGES IN THE EXPRESSION OF EPIGENETIC- AND STRESS-RELATED GENES SUGGEST A POSSIBLE MECHANISM BY WHICH THE EARLY LIFE STRESS BECOMES EMBEDDED IN THE CENTRAL NERVOUS SYSTEM. INCREASED UNDERSTANDING OF THE INTERACTIONS AMONG EARLY-LIFE STRESS, SEX, AND PAIN MAY LEAD TO THE IDENTIFICATION OF NOVEL THERAPEUTIC TARGETS AND EPIGENETIC DRUGS FOR THE TREATMENT OF CHRONIC PAIN DISORDERS. 2020 13 990 41 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 14 3973 38 LONG-TERM BEHAVIORAL AND NEUROENDOCRINE ALTERATIONS FOLLOWING CHRONIC SOCIAL STRESS IN MICE: IMPLICATIONS FOR STRESS-RELATED DISORDERS. THE PERIOD OF ADOLESCENCE IS CHARACTERIZED BY A HIGH VULNERABILITY TO STRESS AND TRAUMA, WHICH MIGHT RESULT IN LONG-LASTING CONSEQUENCES AND AN INCREASED RISK TO DEVELOP PSYCHIATRIC DISORDERS. USING A RECENTLY DEVELOPED MOUSE MODEL FOR CHRONIC SOCIAL STRESS DURING ADOLESCENCE, WE STUDIED PERSISTENT NEUROENDOCRINE AND BEHAVIORAL EFFECTS OF CHRONIC SOCIAL STRESS OBTAINED 12 MONTHS AFTER CESSATION OF THE STRESSOR. AS A REFERENCE, WE INVESTIGATED IMMEDIATE EFFECTS OF CHRONIC STRESS EXPOSURE OBTAINED AT THE END OF THE CHRONIC STRESS PERIOD. IMMEDIATELY AFTER THE 7 WEEK CHRONIC STRESS PERIOD STRESSED ANIMALS SHOW SIGNIFICANTLY INCREASED ADRENAL WEIGHTS, DECREASED THYMUS WEIGHT, INCREASED BASAL CORTICOSTERONE SECRETION AND A FLATTENED CIRCADIAN RHYTHM. FURTHERMORE, STRESSED ANIMALS DISPLAY AN INCREASED ANXIETY-LIKE BEHAVIOR IN THE ELEVATED PLUS MAZE AND THE NOVELTY-INDUCED SUPPRESSION OF FEEDING TEST. HIPPOCAMPAL MINERALOCORTICOID RECEPTOR (MR) AND THE GLUCOCORTICOID RECEPTOR (GR) MRNA LEVELS WERE SIGNIFICANTLY DECREASED. TO INVESTIGATE PERSISTENT CONSEQUENCES OF THIS EARLY STRESSFUL EXPERIENCE, THE SAME PARAMETERS WERE ASSESSED IN AGED MICE 12 MONTHS AFTER THE CESSATION OF THE STRESSOR. INTERESTINGLY, WE STILL FOUND DIFFERENCES BETWEEN FORMERLY STRESSED AND CONTROL MICE IN IMPORTANT STRESS-RELATED PARAMETERS. MR EXPRESSION LEVELS WERE SIGNIFICANTLY LOWER IN STRESSED ANIMALS, SUGGESTING LASTING, POSSIBLY EPIGENETIC ALTERATIONS IN GENE EXPRESSION REGULATION. FURTHERMORE, WE OBSERVED LONG-TERM BEHAVIORAL ALTERATIONS IN ANIMALS STRESSED DURING ADOLESCENCE. THUS, WE COULD DEMONSTRATE THAT CHRONIC STRESS EXPOSURE DURING A CRUCIAL DEVELOPMENTAL TIME PERIOD RESULTS IN LONG-TERM, PERSISTENT EFFECTS ON PHYSIOLOGICAL AND BEHAVIORAL PARAMETERS THROUGHOUT LIFE, WHICH MAY CONTRIBUTE TO AN ENHANCED VULNERABILITY TO STRESS-INDUCED DISEASES. 2008 15 4069 36 MATERNAL CHRONIC FOLATE SUPPLEMENTATION AMELIORATES BEHAVIOR DISORDERS INDUCED BY PRENATAL HIGH-FAT DIET THROUGH METHYLATION ALTERATION OF BDNF AND GRIN2B IN OFFSPRING HIPPOCAMPUS. SCOPE: MATERNAL CONSUMPTION OF A HIGH-FAT DIET (HFD) DURING PREGNANCY INCREASES THE RISK OF BEHAVIORAL PROBLEMS. FOLATE PLAYS AN IMPORTANT ROLE IN NEUROPLASTICITY AND THE PRESERVATION OF NEURONAL INTEGRITY. THIS STUDY AIMS AT DETERMINING THE INFLUENCE OF DIETS SUPPLEMENTED WITH FOLATE ON OFFSPRING BEHAVIOR, AND THE MECHANISMS INVOLVED. METHODS AND RESULTS: FEMALE MICE WERE FED A CONTROL DIET, AN HFD, CONTROL DIET SUPPLEMENTED WITH FOLATE, OR AN HFD SUPPLEMENTED WITH FOLATE FOR 5 WEEKS BEFORE MATING. OPEN FIELD TASK AND ELEVATED PLUS MAZE ARE USED TO EVALUATE THE OFFSPRING BEHAVIORS. RESULTS SHOWED THAT OFFSPRING COGNITIVE PERFORMANCE AND ANXIETY-RELATED BEHAVIORS, INCLUDING THOSE RELATED TO OPEN FIELD EXPLORATION AND ELEVATED PLUS MAZE, WERE SIGNIFICANTLY IMPROVED WHEN DAMS WERE TREATED WITH FOLATE IN PREGNANCY. MOREOVER, THE MATERNAL FOLATE SUPPLEMENT DECREASED BDNF AND GRIN2B METHYLATION AND UPREGULATED THEIR EXPRESSIONS IN THE BRAIN OF OFFSPRING, WHICH WERE ASSOCIATED WITH DECREASING THE EXPRESSION OF DNA METHYLTRANSFERASES COMPARED WITH THOSE DAMS WERE TREATED ONLY HFD IN PREGNANCY. CONCLUSION: MATERNAL FOLATE SUPPLEMENTATION AMELIORATES BEHAVIOR DISORDERS INDUCED BY PRENATAL HIGH-FAT DIET. THE BENEFICIAL EFFECTS WERE ASSOCIATED WITH METHYLATION AND EXPRESSION ALTERATION OF BDNF AND GRIN2B GENES. 2017 16 2740 32 EXPOSURE TO EARLY LIFE STRESS RESULTS IN EPIGENETIC CHANGES IN NEUROTROPHIC FACTOR GENE EXPRESSION IN A PARKINSONIAN RAT MODEL. EARLY LIFE ADVERSITY INCREASES THE RISK OF MENTAL DISORDERS LATER IN LIFE. CHRONIC EARLY LIFE STRESS MAY ALTER NEUROTROPHIC FACTOR GENE EXPRESSION INCLUDING THOSE FOR BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) AND GLIAL CELL DERIVED NEUROTROPHIC FACTOR (GDNF) THAT ARE IMPORTANT IN NEURONAL GROWTH, SURVIVAL, AND MAINTENANCE. MATERNAL SEPARATION WAS USED IN THIS STUDY TO MODEL EARLY LIFE STRESS. FOLLOWING UNILATERAL INJECTION OF A MILD DOSE OF 6-HYDROXYDOPAMINE (6-OHDA), WE MEASURED CORTICOSTERONE (CORT) IN THE BLOOD AND STRIATUM OF STRESSED AND NONSTRESSED RATS; WE ALSO MEASURED DNA METHYLATION AND BDNF AND GDNF GENE EXPRESSION IN THE STRIATUM USING REAL TIME PCR. IN THE PRESENCE OF STRESS, WE FOUND THAT THERE WAS INCREASED CORTICOSTERONE CONCENTRATION IN BOTH BLOOD AND STRIATAL TISSUE. FURTHER TO THIS, WE FOUND HIGHER DNA METHYLATION AND DECREASED NEUROTROPHIC FACTOR GENE EXPRESSION. 6-OHDA LESION INCREASED NEUROTROPHIC FACTOR GENE EXPRESSION IN BOTH STRESSED AND NONSTRESSED RATS BUT THIS INCREASE WAS HIGHER IN THE NONSTRESSED RATS. OUR RESULTS SUGGEST THAT EXPOSURE TO EARLY POSTNATAL STRESS INCREASES CORTICOSTERONE CONCENTRATION WHICH LEADS TO INCREASED DNA METHYLATION. THIS EFFECT RESULTS IN DECREASED BDNF AND GDNF GENE EXPRESSION IN THE STRIATUM LEADING TO DECREASED PROTECTION AGAINST SUBSEQUENT INSULTS LATER IN LIFE. 2016 17 4079 45 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 18 4223 35 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 19 4093 33 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 20 684 38 BRAIN STAT5 MODULATES LONG-TERM METABOLIC AND EPIGENETIC CHANGES INDUCED BY PREGNANCY AND LACTATION IN FEMALE MICE. SEVERAL METABOLIC AND BEHAVIORAL ADAPTATIONS THAT EMERGE DURING PREGNANCY REMAIN PRESENT AFTER WEANING. THUS, REPRODUCTIVE EXPERIENCE CAUSES LONG-LASTING METABOLIC PROGRAMMING, PARTICULARLY IN THE BRAIN. HOWEVER, THE ISOLATE EFFECTS OF PREGNANCY OR LACTATION AND THE MOLECULAR MECHANISMS INVOLVED IN THESE LONG-TERM MODIFICATIONS ARE CURRENTLY UNKNOWN. IN THE CURRENT STUDY, WE INVESTIGATED THE ROLE OF BRAIN SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION-5 (STAT5), A KEY TRANSCRIPTION FACTOR RECRUITED BY HORMONES HIGHLY SECRETED DURING GESTATION OR LACTATION, FOR THE LONG-TERM ADAPTATIONS INDUCED BY REPRODUCTIVE EXPERIENCE. IN CONTROL MICE, PREGNANCY FOLLOWED BY LACTATION LED TO INCREASED BODY ADIPOSITY AND REDUCED AMBULATORY ACTIVITY LATER IN LIFE. ADDITIONALLY, PREGNANCY+LACTATION INDUCED LONG-TERM EPIGENETIC MODIFICATIONS IN THE BRAIN: WE OBSERVED UPREGULATION IN HYPOTHALAMIC EXPRESSION OF HISTONE DEACETYLASES AND REDUCED NUMBERS OF NEURONS WITH HISTONE H3 ACETYLATION IN THE PARAVENTRICULAR, ARCUATE, AND VENTROMEDIAL NUCLEI. REMARKABLY, BRAIN-SPECIFIC STAT5 ABLATION PREVENTED ALL METABOLIC AND EPIGENETIC CHANGES OBSERVED IN REPRODUCTIVELY EXPERIENCED CONTROL FEMALE MICE. NONETHELESS, BRAIN-SPECIFIC STAT5 KNOCKOUT (KO) MICE THAT HAD THE EXPERIENCE OF PREGNANCY BUT DID NOT LACTATE SHOWED INCREASED BODY WEIGHT AND REDUCED ENERGY EXPENDITURE LATER IN LIFE, WHEREAS PREGNANCY KO AND PREGNANCY+LACTATION KO MICE EXHIBITED IMPROVED INSULIN SENSITIVITY COMPARED WITH VIRGIN KO MICE. IN SUMMARY, LACTATION IS NECESSARY FOR THE LONG-LASTING METABOLIC EFFECTS OBSERVED IN REPRODUCTIVELY EXPERIENCED FEMALE MICE. IN ADDITION, EPIGENETIC MECHANISMS INVOLVING HISTONE ACETYLATION IN NEURONAL POPULATIONS RELATED TO ENERGY BALANCE REGULATION ARE POSSIBLY ASSOCIATED WITH THESE LONG-TERM CONSEQUENCES. FINALLY, OUR FINDINGS HIGHLIGHTED THE KEY ROLE PLAYED BY BRAIN STAT5 SIGNALING FOR THE CHRONIC METABOLIC AND EPIGENETIC CHANGES INDUCED BY PREGNANCY AND LACTATION. 2019