1 994 124 CHRONIC STRESS INDUCES SEX-SPECIFIC ALTERATIONS IN METHYLATION AND EXPRESSION OF CORTICOTROPIN-RELEASING FACTOR GENE IN THE RAT. BACKGROUND: ALTHOUGH THE HIGHER PREVALENCE OF DEPRESSION IN WOMEN THAN IN MEN IS WELL KNOWN, THE NEURONAL BASIS OF THIS SEX DIFFERENCE IS LARGELY ELUSIVE. METHODS: MALE AND FEMALE RATS WERE EXPOSED TO CHRONIC VARIABLE MILD STRESS (CVMS) AFTER WHICH IMMEDIATE EARLY GENE PRODUCTS, CORTICOTROPIN-RELEASING FACTOR (CRF) MRNA AND PEPTIDE, VARIOUS EPIGENETIC-ASSOCIATED ENZYMES AND DNA METHYLATION OF THE CRF GENE WERE DETERMINED IN THE HYPOTHALAMIC PARAVENTRICULAR NUCLEUS (PVN), OVAL (BSTOV) AND FUSIFORM (BSTFU) PARTS OF THE BED NUCLEUS OF THE STRIA TERMINALIS, AND CENTRAL AMYGDALA (CEA). RESULTS: CVMS INDUCED SITE-SPECIFIC CHANGES IN CRF GENE METHYLATION IN ALL BRAIN CENTERS STUDIED IN FEMALE RATS AND IN THE MALE BST AND CEA, WHEREAS THE HISTONE ACETYLTRANSFERASE, CREB-BINDING PROTEIN WAS INCREASED IN THE FEMALE BST AND THE HISTONE-DEACETYLASE-5 DECREASED IN THE MALE CEA. THESE CHANGES WERE ACCOMPANIED BY AN INCREASED AMOUNT OF C-FOS IN THE PVN, BSTFU AND CEA IN MALES, AND OF FOSB IN THE PVN OF BOTH SEXES AND IN THE MALE BSTOV AND BSTFU. IN THE PVN, CVMS INCREASED CRF MRNA IN MALES AND CRF PEPTIDE DECREASED IN FEMALES. CONCLUSIONS: THE DATA CONFIRM OUR HYPOTHESIS THAT CHRONIC STRESS AFFECTS GENE EXPRESSION AND CRF TRANSCRIPTIONAL, TRANSLATIONAL AND SECRETORY ACTIVITIES IN THE PVN, BSTOV, BSTFU AND CEA, IN A BRAIN CENTER-SPECIFIC AND SEX-SPECIFIC MANNER. BRAIN REGION-SPECIFIC AND SEX-SPECIFIC CHANGES IN EPIGENETIC ACTIVITY AND NEURONAL ACTIVATION MAY PLAY, TOO, AN IMPORTANT ROLE IN THE SEX SPECIFICITY OF THE STRESS RESPONSE AND THE SUSCEPTIBILITY TO DEPRESSION. 2011 2 2828 36 FLUOXETINE TREATMENT SUPPORTS PREDICTIVE VALIDITY OF THE THREE HIT MODEL OF DEPRESSION IN MALE PACAP HETEROZYGOUS MICE AND UNDERPINS THE IMPACT OF EARLY LIFE ADVERSITY ON THERAPEUTIC EFFICACY. ACCORDING TO THE THREE HIT CONCEPT OF DEPRESSION, INTERACTION OF GENETIC PREDISPOSITION ALTERED EPIGENETIC PROGRAMMING AND ENVIRONMENTAL STRESS FACTORS CONTRIBUTE TO THE DISEASE. EARLIER WE DEMONSTRATED THE CONSTRUCT AND FACE VALIDITY OF OUR THREE HIT CONCEPT-BASED MOUSE MODEL. IN THE PRESENT WORK, WE AIMED TO EXAMINE THE PREDICTIVE VALIDITY OF OUR MODEL, THE THIRD WILLNERIAN CRITERION. FLUOXETINE TREATMENT WAS APPLIED IN CHRONIC VARIABLE MILD STRESS (CVMS)-EXPOSED (ENVIRONMENTAL HIT) CD1 MICE CARRYING ONE MUTATED ALLELE OF PITUITARY ADENYLATE CYCLASE-ACTIVATING POLYPEPTIDE GENE (GENETIC HIT) THAT WERE PREVIOUSLY EXPOSED TO MATERNAL DEPRIVATION (EPIGENETIC HIT) VS. CONTROLS. FLUOXETINE REDUCED THE ANXIETY LEVEL IN CVMS-EXPOSED MICE IN MARBLE BURYING TEST, AND DECREASED THE DEPRESSION LEVEL IN TAIL SUSPENSION TEST IF MICE WERE NOT DEPRIVED MATERNALLY. HISTORY OF MATERNAL DEPRIVATION CAUSED FUNDAMENTAL FUNCTIONAL-MORPHOLOGICAL CHANGES IN RESPONSE TO CVMS AND FLUOXETINE TREATMENT IN THE CORTICOTROPIN-RELEASING HORMONE-PRODUCING CELLS OF THE BED NUCLEUS OF THE STRIA TERMINALIS AND CENTRAL AMYGDALA, IN TYROSINE-HYDROXYLASE CONTENT OF VENTRAL TEGMENTAL AREA, IN UROCORTIN 1-EXPRESSING CELLS OF THE CENTRALLY PROJECTING EDINGER-WESTPHAL NUCLEUS, AND SEROTONERGIC CELLS OF THE DORSAL RAPHE NUCLEUS. THE EPIGENETIC BACKGROUND OF ALTERATIONS WAS APPROVED BY ALTERED ACETYLATION OF HISTONE H3. OUR FINDINGS FURTHER SUPPORT THE VALIDITY OF BOTH THE THREE HIT CONCEPT AND THAT OF OUR ANIMAL MODEL. REVERSAL OF BEHAVIORAL AND FUNCTIONAL-MORPHOLOGICAL ANOMALIES BY FLUOXETINE TREATMENT SUPPORTS THE PREDICTIVE VALIDITY OF THE MODEL. THIS STUDY HIGHLIGHTS THAT EARLY LIFE STRESS DOES NOT ONLY INTERACT WITH THE GENETIC AND ENVIRONMENTAL FACTORS, BUT HAS STRONG INFLUENCE ALSO ON THERAPEUTIC EFFICACY. 2022 3 4948 38 PATERNAL STRESS EXPOSURE ALTERS SPERM MICRORNA CONTENT AND REPROGRAMS OFFSPRING HPA STRESS AXIS REGULATION. NEUROPSYCHIATRIC DISEASE FREQUENTLY PRESENTS WITH AN UNDERLYING HYPOREACTIVITY OR HYPERREACTIVITY OF THE HPA STRESS AXIS, SUGGESTING AN EXCEPTIONAL VULNERABILITY OF THIS CIRCUITRY TO EXTERNAL PERTURBATIONS. PARENTAL LIFETIME EXPOSURES TO ENVIRONMENTAL CHALLENGES ARE ASSOCIATED WITH INCREASED OFFSPRING NEUROPSYCHIATRIC DISEASE RISK, AND LIKELY CONTRIBUTE TO STRESS DYSREGULATION. WHILE MATERNAL INFLUENCES HAVE BEEN EXTENSIVELY EXAMINED, MUCH LESS IS KNOWN REGARDING THE SPECIFIC ROLE OF PATERNAL FACTORS. TO INVESTIGATE THE POTENTIAL MECHANISMS BY WHICH PATERNAL STRESS MAY CONTRIBUTE TO OFFSPRING HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS DYSREGULATION, WE EXPOSED MICE TO 6 WEEKS OF CHRONIC STRESS BEFORE BREEDING. AS EPIDEMIOLOGICAL STUDIES SUPPORT VARIATION IN PATERNAL GERM CELL SUSCEPTIBILITY TO REPROGRAMMING ACROSS THE LIFESPAN, MALE STRESS EXPOSURE OCCURRED EITHER THROUGHOUT PUBERTY OR IN ADULTHOOD. REMARKABLY, OFFSPRING OF SIRES FROM BOTH PATERNAL STRESS GROUPS DISPLAYED SIGNIFICANTLY REDUCED HPA STRESS AXIS RESPONSIVITY. GENE SET ENRICHMENT ANALYSES IN OFFSPRING STRESS REGULATING BRAIN REGIONS, THE PARAVENTRICULAR NUCLEUS (PVN) AND THE BED NUCLEUS OF STRIA TERMINALIS, REVEALED GLOBAL PATTERN CHANGES IN TRANSCRIPTION SUGGESTIVE OF EPIGENETIC REPROGRAMMING AND CONSISTENT WITH ALTERED OFFSPRING STRESS RESPONSIVITY, INCLUDING INCREASED EXPRESSION OF GLUCOCORTICOID-RESPONSIVE GENES IN THE PVN. IN EXAMINING POTENTIAL EPIGENETIC MECHANISMS OF GERM CELL TRANSMISSION, WE FOUND ROBUST CHANGES IN SPERM MICRORNA (MIR) CONTENT, WHERE NINE SPECIFIC MIRS WERE SIGNIFICANTLY INCREASED IN BOTH PATERNAL STRESS GROUPS. OVERALL, THESE RESULTS DEMONSTRATE THAT PATERNAL EXPERIENCE ACROSS THE LIFESPAN CAN INDUCE GERM CELL EPIGENETIC REPROGRAMMING AND IMPACT OFFSPRING HPA STRESS AXIS REGULATION, AND MAY THEREFORE OFFER NOVEL INSIGHT INTO FACTORS INFLUENCING NEUROPSYCHIATRIC DISEASE RISK. 2013 4 4944 27 PATERNAL PRECONCEPTION ETHANOL EXPOSURE BLUNTS HYPOTHALAMIC-PITUITARY-ADRENAL AXIS RESPONSIVITY AND STRESS-INDUCED EXCESSIVE FLUID INTAKE IN MALE MICE. A GROWING NUMBER OF ENVIRONMENTAL INSULTS HAVE BEEN SHOWN TO INDUCE EPIGENETIC EFFECTS THAT PERSIST ACROSS GENERATIONS. FOR INSTANCE, PATERNAL PRECONCEPTION EXPOSURES TO ETHANOL OR STRESS HAVE INDEPENDENTLY BEEN SHOWN TO EXERT SUCH INTERGENERATIONAL EFFECTS. SINCE ETHANOL EXPOSURE IS A PHYSIOLOGICAL STRESSOR THAT ACTIVATES THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS, WE HYPOTHESIZED THAT PATERNAL ETHANOL EXPOSURE WOULD IMPACT STRESS RESPONSIVITY OF OFFSPRING. ADULT MALE MICE WERE EXPOSED TO CHRONIC INTERMITTENT VAPOR ETHANOL OR CONTROL CONDITIONS FOR 5 WEEKS BEFORE BEING MATED WITH ETHANOL-NAIVE FEMALES TO PRODUCE ETHANOL (E)- AND CONTROL (C)-SIRED OFFSPRING. ADULT MALE AND FEMALE OFFSPRING WERE TESTED FOR PLASMA CORTICOSTERONE (CORT) LEVELS FOLLOWING ACUTE RESTRAINT STRESS AND THE MALE OFFSPRING WERE FURTHER EXAMINED FOR STRESS-EVOKED 2-BOTTLE CHOICE ETHANOL-DRINKING. PATERNAL ETHANOL EXPOSURE BLUNTED PLASMA CORT LEVELS FOLLOWING ACUTE RESTRAINT STRESS SELECTIVELY IN MALE OFFSPRING; FEMALES WERE UNAFFECTED. IN A STRESS-EVOKED ETHANOL-DRINKING ASSAY, THERE WAS NO EFFECT OF STRESS ON ETHANOL CONSUMPTION. HOWEVER, C-SIRED MALES EXHIBITED INCREASED TOTAL FLUID INTAKE (POLYDIPSIA) IN RESPONSE TO STRESS WHILE E-SIRED MALES WERE RESISTANT TO THIS STRESS-INDUCED PHENOTYPE. TAKEN TOGETHER, THESE DATA SUGGEST THAT PATERNAL ETHANOL EXPOSURE IMPARTS STRESS HYPORESPONSIVITY TO MALE OFFSPRING. 2016 5 5651 36 SEX DIFFERENCES IN THE EPIGENETIC REGULATION OF CHRONIC VISCERAL PAIN FOLLOWING UNPREDICTABLE EARLY LIFE STRESS. BACKGROUND: WE PREVIOUSLY REPORTED THAT EARLY LIFE STRESS (ELS) DYSREGULATED GLUCOCORTICOID RECEPTOR (GR) AND CORTICOTROPHIN-RELEASING HORMONE (CRH) EXPRESSION IN THE CENTRAL NUCLEUS OF THE AMYGDALA (CEA). EPIGENETIC MODIFICATIONS SERVE AS MEMORIES OF ADVERSE EVENTS THAT OCCURRED DURING EARLY LIFE. THEREFORE, WE HYPOTHESIZED THAT EPIGENETIC MECHANISMS ALTER GR AND CRH EXPRESSION IN THE CEA AND UNDERLIE CHRONIC VISCERAL PAIN AFTER ELS. METHODS: NEONATAL RATS WERE EXPOSED TO UNPREDICTABLE, PREDICTABLE ELS, OR ODOR ONLY (NO STRESS CONTROL) FROM POSTNATAL DAYS 8 TO 12. IN ADULTHOOD, VISCERAL SENSITIVITY WAS ASSESSED OR THE CEA WAS ISOLATED FOR WESTERN BLOT OR CHIP-QPCR TO STUDY HISTONE MODIFICATIONS AT THE GR AND CRH PROMOTERS. FEMALE ADULT RATS UNDERWENT STEREOTAXIC IMPLANTATION OF INDWELLING CANNULAS FOR MICROINJECTIONS OF GARCINOL (HAT INHIBITOR) INTO THE CEA. AFTER 7 DAYS OF MICROINJECTIONS, VISCERAL SENSITIVITY WAS ASSESSED OR THE CEA WAS ISOLATED FOR CHIP-QPCR ASSAYS. RESULTS: UNPREDICTABLE ELS INCREASED VISCERAL SENSITIVITY IN ADULT FEMALE RATS, BUT NOT IN MALE COUNTERPARTS. ELS INCREASED HISTONE 3 LYSINE 9 (H3K9) ACETYLATION IN THE CEA AND H3K9 ACETYLATION LEVELS AT THE GR PROMOTER IN THE CEA OF ADULT FEMALE RATS. AFTER UNPREDICTABLE ELS, H3K9 ACETYLATION WAS INCREASED AND GR BINDING WAS DECREASED AT THE CRH PROMOTER. ADMINISTRATION OF GARCINOL IN THE CEA OF ADULT FEMALES, THAT UNDERWENT UNPREDICTABLE ELS, NORMALIZED H3K9 ACETYLATION AND RESTORED GR BINDING AT THE CRH PROMOTER. CONCLUSION: DYSREGULATED HISTONE ACETYLATION AND GR BINDING AT THE CRH PROMOTER IN THE CEA ARE AN IMPORTANT MECHANISM FOR "MEMORIZING" ELS EVENTS MEDIATING VISCERAL PAIN IN ADULTHOOD. 2020 6 1999 32 EPIGENETIC AND NEURONAL ACTIVITY MARKERS SUGGEST THE RECRUITMENT OF THE PREFRONTAL CORTEX AND HIPPOCAMPUS IN THE THREE-HIT MODEL OF DEPRESSION IN MALE PACAP HETEROZYGOUS MICE. DEPRESSION AND ITS INCREASING PREVALENCE CHALLENGE PATIENTS, THE HEALTHCARE SYSTEM, AND THE ECONOMY. WE RECENTLY CREATED A MOUSE MODEL BASED ON THE THREE-HIT CONCEPT OF DEPRESSION. AS GENETIC PREDISPOSITION (FIRST HIT), WE APPLIED PITUITARY ADENYLATE CYCLASE-ACTIVATING POLYPEPTIDE HETEROZYGOUS MICE ON CD1 BACKGROUND. MATERNAL DEPRIVATION MODELED THE EPIGENETIC FACTOR (SECOND HIT), AND THE CHRONIC VARIABLE MILD STRESS WAS THE ENVIRONMENTAL FACTOR (THIRD HIT). FLUOXETINE TREATMENT WAS APPLIED TO TEST THE PREDICTIVE VALIDITY OF OUR MODEL. WE AIMED TO EXAMINE THE DYNAMICS OF THE EPIGENETIC MARKER ACETYL-LYSINE 9 H3 HISTONE (H3K9AC) AND THE NEURONAL ACTIVITY MARKER FOSB IN THE PREFRONTAL CORTEX (PFC) AND HIPPOCAMPUS. FLUOXETINE DECREASED H3K9AC IN PFC IN NON-DEPRIVED ANIMALS, BUT A HISTORY OF MATERNAL DEPRIVATION ABOLISHED THE EFFECT OF STRESS AND SSRI TREATMENT ON H3K9AC IMMUNOREACTIVITY. IN THE HIPPOCAMPUS, STRESS DECREASED, WHILE SSRI INCREASED H3K9AC IMMUNOSIGNAL, UNLIKE IN THE DEPRIVED MICE, WHERE THE OPPOSITE EFFECT WAS DETECTED. FOSB IN STRESS WAS STIMULATED BY FLUOXETINE IN THE PFC, WHILE IT WAS INHIBITED IN THE HIPPOCAMPUS. THE FOSB IMMUNOREACTIVITY WAS ALMOST COMPLETELY ABOLISHED IN THE HIPPOCAMPUS OF THE DEPRIVED MICE. THIS STUDY SHOWED THAT FOSB AND H3K9AC WERE MODULATED IN A TERRITORY-SPECIFIC MANNER BY EARLY LIFE ADVERSITIES AND LATER LIFE STRESS INTERACTING WITH THE EFFECT OF FLUOXETINE THERAPY SUPPORTING THE RELIABILITY OF OUR MODEL. 2022 7 2905 32 GENE DYSREGULATION IN THE ADULT RAT PARAVENTRICULAR NUCLEUS AND AMYGDALA BY PRENATAL EXPOSURE TO DEXAMETHASONE. FETAL PROGRAMMING IS THE CONCEPT THAT MATERNAL STRESSORS DURING CRITICAL PERIODS OF FETAL DEVELOPMENT CAN ALTER OFFSPRING PHENOTYPES POSTNATALLY. EXCESS GLUCOCORTICOIDS CAN INTERACT WITH THE FETUS TO EFFECT GENETIC AND EPIGENETIC CHANGES IMPLICATED IN ADVERSE DEVELOPMENTAL OUTCOMES. THE PRESENT STUDY INVESTIGATES HOW CHRONIC EXPOSURE TO THE SYNTHETIC GLUCOCORTICOID DEXAMETHASONE DURING LATE GESTATION ALTERS THE EXPRESSION OF GENES RELATED TO BEHAVIOR IN BRAIN AREAS RELEVANT TO THE REGULATION AND FUNCTION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS. PREGNANT WISTAR KYOTO RATS RECEIVED SUBCUTANEOUS INJECTIONS OF DEXAMETHASONE (100 MUG/KG) DAILY FROM GESTATIONAL DAY 15-21 OR VEHICLE ONLY AS SHAM CONTROLS. THE AMYGDALA AND PARAVENTRICULAR NUCLEUS (PVN) WERE MICRO-PUNCHED TO EXTRACT MRNA FOR REVERSE TRANSCRIPTION AND QUANTITATIVE POLYMERASE CHAIN REACTION FOR THE ANALYSIS OF THE EXPRESSION OF SPECIFIC GENES. IN THE PVN, THE EXPRESSION OF THE GLUCOCORTICOID RECEPTOR NR3C1 WAS DOWNREGULATED IN FEMALE RATS IN RESPONSE TO PROGRAMMING. THE EXPRESSION OF CACNA1C ENCODING THE CA(V)1.2 PORE SUBUNIT OF L-TYPE VOLTAGE-GATED CALCIUM CHANNELS WAS DOWNREGULATED IN MALE AND FEMALE RATS PRENATALLY EXPOSED TO DEXAMETHASONE. COLLECTIVELY, THE RESULTS SUGGEST THAT PRENATAL EXPOSURE TO ELEVATED LEVELS OF GLUCOCORTICOIDS PLAYS A ROLE IN THE DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS AND POTENTIALLY LEARNING AND MEMORY BY ALTERING THE EXPRESSION OF SPECIFIC GENES WITHIN THE AMYGDALA AND PVN. 2022 8 4222 34 METHYLATION AT THE CPG ISLAND SHORE REGION UPREGULATES NR3C1 PROMOTER ACTIVITY AFTER EARLY-LIFE STRESS. EARLY-LIFE STRESS (ELS) INDUCES LONG-LASTING CHANGES IN GENE EXPRESSION CONFERRING AN INCREASED RISK FOR THE DEVELOPMENT OF STRESS-RELATED MENTAL DISORDERS. GLUCOCORTICOID RECEPTORS (GR) MEDIATE THE NEGATIVE FEEDBACK ACTIONS OF GLUCOCORTICOIDS (GC) IN THE PARAVENTRICULAR NUCLEUS (PVN) OF THE HYPOTHALAMUS AND ANTERIOR PITUITARY AND THEREFORE PLAY A KEY ROLE IN THE REGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS AND THE ENDOCRINE RESPONSE TO STRESS. WE HERE SHOW THAT ELS PROGRAMS THE EXPRESSION OF THE GR GENE (NR3C1) BY SITE-SPECIFIC HYPERMETHYLATION AT THE CPG ISLAND (CGI) SHORE IN HYPOTHALAMIC NEURONS THAT PRODUCE CORTICOTROPIN-RELEASING HORMONE (CRH), THUS PREVENTING CRH UPREGULATION UNDER CONDITIONS OF CHRONIC STRESS. CPGS MAPPING TO THE NR3C1 CGI SHORE REGION ARE DYNAMICALLY REGULATED BY ELS AND UNDERPIN METHYLATION-SENSITIVE CONTROL OF THIS REGION'S INSULATION-LIKE FUNCTION VIA YING YANG 1 (YY1) BINDING. OUR RESULTS PROVIDE NEW INSIGHT INTO HOW A GENOMIC ELEMENT INTEGRATES EXPERIENCE-DEPENDENT EPIGENETIC PROGRAMMING OF THE COMPOSITE PROXIMAL NR3C1 PROMOTER, AND ASSIGNS AN INSULATING ROLE TO THE CGI SHORE. 2015 9 2187 49 EPIGENETIC MECHANISMS UNDERLYING STRESS-INDUCED VISCERAL PAIN: RESILIENCE VERSUS VULNERABILITY IN A TWO-HIT MODEL OF EARLY LIFE STRESS AND CHRONIC ADULT STRESS. BACKGROUND: WOMEN WITH A HISTORY OF EARLY LIFE STRESS (ELS) HAVE A HIGHER RISK OF DEVELOPING IRRITABLE BOWEL SYNDROME (IBS). IN ADDITION, CHRONIC STRESS IN ADULTHOOD CAN EXACERBATE IBS SYMPTOMS SUCH AS ABDOMINAL PAIN DUE TO VISCERAL HYPERSENSITIVITY. WE PREVIOUSLY SHOWED THAT SEX AND THE PREDICTABILITY OF ELS DETERMINE WHETHER RATS DEVELOP VISCERAL HYPERSENSITIVITY IN ADULTHOOD. IN FEMALE RATS, UNPREDICTABLE ELS CONFERS VULNERABILITY AND RESULTS IN VISCERAL HYPERSENSITIVITY, WHEREAS PREDICTABLE ELS INDUCES RESILIENCE AND DOES NOT INDUCE VISCERAL HYPERSENSITIVITY IN ADULTHOOD. HOWEVER, THIS RESILIENCE IS LOST AFTER EXPOSURE TO CHRONIC STRESS IN ADULTHOOD LEADING TO AN EXACERBATION OF VISCERAL HYPERSENSITIVITY. EVIDENCE SUGGESTS THAT CHANGES IN HISTONE ACETYLATION AT THE PROMOTER REGIONS OF GLUCOCORTICOID RECEPTOR (GR) AND CORTICOTROPHIN-RELEASING FACTOR (CRF) IN THE CENTRAL NUCLEUS OF THE AMYGDALA (CEA) UNDERLIE STRESS-INDUCED VISCERAL HYPERSENSITIVITY. HERE, WE AIMED TO INVESTIGATE THE ROLE OF HISTONE ACETYLATION IN THE CEA ON VISCERAL HYPERSENSITIVITY IN A TWO-HIT MODEL OF ELS FOLLOWED BY CHRONIC STRESS IN ADULTHOOD. METHODS: MALE AND FEMALE NEONATAL RATS WERE EXPOSED TO UNPREDICTABLE, PREDICTABLE ELS, OR ODOR ONLY (NO STRESS CONTROL) FROM POSTNATAL DAYS 8 TO 12. IN ADULTHOOD, RATS UNDERWENT STEREOTAXIC IMPLANTATION OF INDWELLING CANNULAS. RATS WERE EXPOSED TO CHRONIC WATER AVOIDANCE STRESS (WAS, 1 H/DAY FOR 7 DAYS) OR SHAM STRESS AND RECEIVED INFUSIONS OF VEHICLE, THE HISTONE DEACETYLASE INHIBITOR TRICHOSTATIN A (TSA) OR THE HISTONE ACETYLTRANSFERASE INHIBITOR GARCINOL (GAR) AFTER EACH WAS SESSION. 24 H AFTER THE FINAL INFUSION, VISCERAL SENSITIVITY WAS ASSESSED AND THE CEA WAS REMOVED FOR MOLECULAR EXPERIMENTS. RESULTS: IN THE TWO-HIT MODEL (ELS + WAS), FEMALE RATS PREVIOUSLY EXPOSED TO PREDICTABLE ELS, SHOWED A SIGNIFICANT REDUCTION IN HISTONE 3 LYSINE 9 (H3K9) ACETYLATION AT THE GR PROMOTER AND A SIGNIFICANT INCREASE IN H3K9 ACETYLATION AT THE CRF PROMOTER. THESE EPIGENETIC CHANGES WERE ASSOCIATED WITH CHANGES IN GR AND CRF MRNA EXPRESSION IN THE CEA AND AN EXACERBATION OF STRESS-INDUCED VISCERAL HYPERSENSITIVITY IN FEMALE ANIMALS. TSA INFUSIONS IN THE CEA ATTENUATED THE EXACERBATED STRESS-INDUCED VISCERAL HYPERSENSITIVITY, WHEREAS GAR INFUSIONS ONLY PARTIALLY AMELIORATED ELS+WAS INDUCED VISCERAL HYPERSENSITIVITY. CONCLUSION: THE TWO-HIT MODEL OF ELS FOLLOWED BY WAS IN ADULTHOOD REVEALED THAT EPIGENETIC DYSREGULATION OCCURS AFTER EXPOSURE TO STRESS IN TWO IMPORTANT PERIODS OF LIFE AND CONTRIBUTES TO THE DEVELOPMENT OF VISCERAL HYPERSENSITIVITY. THESE ABERRANT UNDERLYING EPIGENETIC CHANGES MAY EXPLAIN THE EXACERBATION OF STRESS-INDUCED ABDOMINAL PAIN IN IBS PATIENTS. 2023 10 5200 31 PRENATAL MATERNAL STRESS PREDICTS METHYLATION OF GENES REGULATING THE HYPOTHALAMIC-PITUITARY-ADRENOCORTICAL SYSTEM IN MOTHERS AND NEWBORNS IN THE DEMOCRATIC REPUBLIC OF CONGO. EXPOSURE TO STRESS EARLY IN LIFE PERMANENTLY SHAPES ACTIVITY OF THE HYPOTHALAMIC-PITUITARY-ADRENOCORTICAL (HPA) AXIS AND THE BRAIN. PRENATALLY, GLUCOCORTICOIDS PASS THROUGH THE PLACENTA TO THE FETUS WITH POSTNATAL IMPACTS ON BRAIN DEVELOPMENT, BIRTH WEIGHT (BW), AND HPA AXIS FUNCTIONING. LITTLE IS KNOWN ABOUT THE BIOLOGICAL MECHANISMS BY WHICH PRENATAL STRESS AFFECTS POSTNATAL FUNCTIONING. THIS STUDY ADDRESSES THIS GAP BY EXAMINING THE EFFECT OF CHRONIC STRESS AND TRAUMATIC WAR-RELATED STRESS ON EPIGENETIC CHANGES IN FOUR KEY GENES REGULATING THE HPA AXIS IN NEONATAL CORD BLOOD, PLACENTA, AND MATERNAL BLOOD: CRH, CRHBP, NR3C1, AND FKBP5. PARTICIPANTS WERE 24 MOTHER-NEWBORN DYADS IN THE CONFLICT-RIDDEN REGION OF THE EASTERN DEMOCRATIC REPUBLIC OF CONGO. BW DATA WERE COLLECTED AT DELIVERY AND MATERNAL INTERVIEWS WERE CONDUCTED TO ASSESS CULTURALLY RELEVANT CHRONIC AND WAR-RELATED STRESSORS. CHRONIC STRESS AND WAR TRAUMA HAD WIDESPREAD EFFECTS ON HPA AXIS GENE METHYLATION, WITH SIGNIFICANT EFFECTS OBSERVED AT TRANSCRIPTION FACTOR BINDING (TFB) SITES IN ALL TARGET GENES TESTED. SOME CHANGES IN METHYLATION WERE UNIQUE TO CHRONIC OR WAR STRESS, WHEREAS OTHERS WERE OBSERVED ACROSS BOTH STRESSOR TYPES. MOREOVER, STRESS EXPOSURES IMPACTED MATERNAL AND FETAL TISSUES DIFFERENTLY, SUPPORTING THEORETICAL MODELS THAT STRESS IMPACTS VARY ACCORDING TO LIFE PHASE. METHYLATION IN SEVERAL NR3C1 AND CRH CPG SITES, ALL LOCATED AT TFB SITES, WAS ASSOCIATED WITH BW. THESE FINDINGS SUGGEST THAT PRENATAL STRESS EXPOSURE IMPACTS DEVELOPMENT VIA EPIGENETIC CHANGES IN HPA AXIS GENES. 2016 11 2371 43 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 12 5749 33 SOCIAL DEFEAT INDUCES CHANGES IN HISTONE ACETYLATION AND EXPRESSION OF HISTONE MODIFYING ENZYMES IN THE VENTRAL HIPPOCAMPUS, PREFRONTAL CORTEX, AND DORSAL RAPHE NUCLEUS. CHRONIC EXPOSURE TO STRESS IS ASSOCIATED WITH A NUMBER OF PSYCHIATRIC DISORDERS, BUT LITTLE IS KNOWN ABOUT THE EPIGENETIC MECHANISMS THAT UNDERLIE THE STRESS RESPONSE OR RESILIENCE TO CHRONIC STRESS. WE INVESTIGATED HISTONE ACETYLATION IN SEVEN DIFFERENT BRAIN REGIONS OF RATS EXPOSED TO CHRONIC SOCIAL DEFEAT STRESS: THE DORSAL HIPPOCAMPUS (DHPC), VENTRAL HIPPOCAMPUS (VHPC), MEDIAL PREFRONTAL CORTEX (MPFC), BASOLATERAL AMYGDALA (BLA), LOCUS COERULEUS (LC), PARAVENTRICULAR THALAMUS (PVT), AND DORSAL RAPHE (DR) NUCLEUS. THIS STRESS PARADIGM WAS UNIQUE IN THAT IT ALLOWED RATS TO DISPLAY RESILIENCE IN THE FORM OF AN ACTIVE COPING MECHANISM. WE FOUND THAT THERE WAS AN INCREASE IN ACETYLATION OF H3K9/14 (H3K9/14AC) AND BULK ACETYLATION OF H4K5,8,12,16 (H4K5,8,12,16AC) IN THE DR NUCLEUS OF RATS THAT WERE LESS RESILIENT. LESS RESILIENT RATS ALSO DISPLAYED INCREASED LEVELS OF H3K18 ACETYLATION (H3K18AC) IN THE MPFC WHEN COMPARED TO NON-STRESSED CONTROLS. IN THE VHPC, THERE WAS AN INCREASE IN H3K18AC AND H4K12 (H4K12AC) IN RATS THAT WERE LESS RESILIENT WHEN COMPARED TO NON-STRESSED CONTROL RATS. IN ADDITION, THERE WAS A DECREASE IN LEVELS OF H4K8 ACETYLATION (H4K8AC) IN BOTH RESILIENT AND NON-RESILIENT RATS AS COMPARED TO CONTROLS. WE ASSESSED EXPRESSION OF HISTONE MODIFYING ENZYMES IN THE VHPC AND THE MPFC USING QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (PCR) AND FOUND CHANGES IN EXPRESSION OF A NUMBER OF TARGETS. THESE INCLUDED CHANGES IN SIRT1 AND SIRT2 IN THE VHPC AND CHANGES IN KAT5 IN THE MPFC. OVERALL, THESE RESULTS SUGGEST THAT CHANGES IN HISTONE ACETYLATION AND EXPRESSION OF HISTONE MODIFYING ENZYMES IN THESE REGIONS CORRELATE WITH THE BEHAVIORAL RESPONSE TO STRESS IN SOCIALLY DEFEATED RATS. 2014 13 4943 33 PATERNAL PRECONCEPTION ALCOHOL EXPOSURE IMPARTS INTERGENERATIONAL ALCOHOL-RELATED BEHAVIORS TO MALE OFFSPRING ON A PURE C57BL/6J BACKGROUND. WHILE ALCOHOL USE DISORDER (AUD) IS A HIGHLY HERITABLE CONDITION, THE BASIS OF AUD IN FAMILIES WITH A HISTORY OF ALCOHOLISM IS DIFFICULT TO EXPLAIN BY GENETIC VARIATION ALONE. EMERGING EVIDENCE SUGGESTS THAT PARENTAL EXPERIENCE PRIOR TO CONCEPTION CAN AFFECT INHERITANCE OF COMPLEX BEHAVIORS IN OFFSPRING VIA NON-GENOMIC (EPIGENETIC) MECHANISMS. FOR INSTANCE, MALE C57BL/6J (B6) MICE EXPOSED TO CHRONIC INTERMITTENT VAPOR ETHANOL (CIE) PRIOR TO MATING WITH STRAIN 129S1/SVIMJ ETHANOL-NAIVE FEMALES PRODUCE MALE OFFSPRING WITH REDUCED ETHANOL-DRINKING PREFERENCE, INCREASED ETHANOL SENSITIVITY, AND INCREASED BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) EXPRESSION IN THE VENTRAL TEGMENTAL AREA (VTA). IN THE PRESENT STUDY, WE TESTED THE HYPOTHESIS THAT THESE INTERGENERATIONAL EFFECTS OF PATERNAL CIE ARE REPRODUCIBLE IN MALE OFFSPRING ON AN INBRED B6 BACKGROUND. TO THIS END, B6 MALES WERE EXPOSED TO 6 WEEKS OF CIE (OR ROOM AIR AS A CONTROL) BEFORE MATING WITH ETHANOL-NAIVE B6 FEMALES TO PRODUCE ETHANOL (E)-SIRED AND CONTROL (C)-SIRED MALE AND FEMALE OFFSPRING. WE OBSERVED A SEX-SPECIFIC EFFECT, AS E-SIRED MALES EXHIBITED DECREASED TWO-BOTTLE FREE-CHOICE ETHANOL-DRINKING PREFERENCE, INCREASED SENSITIVITY TO THE ANXIOLYTIC EFFECTS OF ETHANOL, AND INCREASED VTA BDNF EXPRESSION; NO DIFFERENCES WERE OBSERVED IN FEMALE OFFSPRING. THESE FINDINGS CONFIRM AND EXTEND OUR PREVIOUS RESULTS BY DEMONSTRATING THAT THE EFFECTS OF PATERNAL PRECONCEPTION ETHANOL ARE REPRODUCIBLE USING GENETICALLY IDENTICAL, INBRED B6 ANIMALS. 2017 14 6267 28 THE NEUROENDOCRINOLOGY OF STRESS: A NEVER ENDING STORY. EVOLUTIONARY SUCCESS DEPENDS ON OUR ABILITY TO ADAPT TO CHANGING CIRCUMSTANCES. THE NEUROENDOCRINE RESPONSE TO STRESS IS AN EXCELLENT EXAMPLE OF A PLASTIC SYSTEM THAT RESPONDS TO THREATS TO HOMEOSTASIS AND ALTERS ITS OUTPUT TO MEET CURRENT AND EXPECTED FUTURE DEMANDS. AT THE LEVEL OF THE HYPOTHALAMUS, THE CORTICOTROPH SECRETAGOGUES CORTICOTROPHIN-RELEASING HORMONE (CRH) AND ARGININE VASOPRESSIN (AVP) RESPOND RAPIDLY TO AN ACUTE STRESSOR BUT, FOLLOWING CHRONIC STRESS, THEY ADAPT WITH A REDUCTION OF CRH BUT A MAJOR INCREASE IN AVP. THE RELEASE OF CRH AND AVP ACTIVATES PRO-OPIOMELANOCORTIN IN ANTERIOR PITUITARY CORTICOTROPH CELLS AND THE RELEASE OF ADRENOCORTICOTROPHIC HORMONE INTO PERIPHERAL BLOOD FROM WHERE IT TARGETS RECEPTORS IN THE ADRENAL CORTEX TO RELEASE GLUCOCORTICOID HORMONES. THESE HORMONES (I.E. CORTICOSTERONE IN THE RAT AND CORTISOL IN MAN) ARE RELEASED IN A PULSATILE ULTRADIAN PATTERN WHICH DEFINES THE NORMAL CIRCADIAN RHYTHM. THE FREQUENCY OF THE PULSES IS INCREASED UNDER STATES OF CHRONIC STRESS, AND IN RATS WITH GENETICALLY DETERMINED HYPER-RESPONSIVENESS OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS. INTERESTINGLY, NEONATAL INFLUENCES CAN ALSO PROGRAMME ALTERATIONS IN ULTRADIAN RHYTHMICITY, IMPLICATING EPIGENETIC FACTORS IN ITS REGULATION. AT THE LEVEL OF TISSUE RECEPTORS, THE ALTERATION IN PATTERN OF GLUCOCORTICOID ULTRADIAN RHYTHM HAS DIFFERENTIAL EFFECTS ON MINERALOCORTICOID RECEPTOR AND GLUCOCORTICOID RECEPTOR (GR) BINDING TO DNA AND OFFERS A MECHANISM FOR TISSUE SPECIFIC RESPONSES TO ALTERED GLUCOCORTICOID DYNAMICS. THE EFFECTS OF NEONATAL EXPERIENCE ARE NOT ONLY SEEN AT THE LEVEL OF CRH AND GR REGULATION, BUT ALSO ARE EVIDENT IN BEHAVIOURAL RESPONSES TO STRESS AND IN THE RESPONSIVENESS OF BRAIN STEM SEROTONERGIC PATHWAYS, AS MEASURED BY TRYPTOPHAN HYDROXYLASE MRNA IN THE BRAIN STEM. 2008 15 2243 31 EPIGENETIC MODULATION OF CHRONIC ANXIETY AND PAIN BY HISTONE DEACETYLATION. PROLONGED EXPOSURE OF THE CENTRAL AMYGDALA (CEA) TO ELEVATED CORTICOSTEROIDS (CORT) FACILITATES LONG-TERM ANXIETY AND PAIN THROUGH ACTIVATION OF GLUCOCORTICOID RECEPTORS (GRS) AND CORTICOTROPIN-RELEASING FACTOR (CRF). HOWEVER, THE MECHANISMS MAINTAINING THESE RESPONSES ARE UNKNOWN. SINCE CHRONIC PHENOTYPES CAN BE SUSTAINED BY EPIGENETIC MECHANISMS, INCLUDING HISTONE MODIFICATIONS SUCH AS DEACETYLATION, WE TESTED THE HYPOTHESIS THAT HISTONE DEACETYLATION CONTRIBUTES TO THE MAINTENANCE OF CHRONIC ANXIETY AND PAIN INDUCED BY PROLONGED EXPOSURE OF THE CEA TO CORT. WE FOUND THAT BILATERAL INFUSIONS OF A HISTONE DEACETYLASE INHIBITOR INTO THE CEA ATTENUATED ANXIETY-LIKE BEHAVIOR AS WELL AS SOMATIC AND VISCERAL HYPERSENSITIVITY RESULTING FROM ELEVATED CORT EXPOSURE. MOREOVER, WE DELINEATED A NOVEL PATHWAY THROUGH WHICH HISTONE DEACETYLATION COULD CONTRIBUTE TO CORT REGULATION OF GR AND SUBSEQUENT CRF EXPRESSION IN THE CEA. SPECIFICALLY, DEACETYLATION OF HISTONE 3 AT LYSINE 9 (H3K9), THROUGH THE COORDINATED ACTION OF THE NAD+-DEPENDENT PROTEIN DEACETYLASE SIRTUIN-6 (SIRT6) AND NUCLEAR FACTOR KAPPA B (NFKAPPAB), SEQUESTERS GR EXPRESSION LEADING TO DISINHIBITION OF CRF. OUR RESULTS INDICATE THAT EPIGENETIC PROGRAMMING IN THE AMYGDALA, SPECIFICALLY HISTONE MODIFICATIONS, IS IMPORTANT IN THE MAINTENANCE OF CHRONIC ANXIETY AND PAIN. 2015 16 3463 34 HYPOTHALAMIC-PITUITARY-ADRENAL AND HYPOTHALAMIC-PITUITARY-GONADAL AXES: SEX DIFFERENCES IN REGULATION OF STRESS RESPONSIVITY. GONADAL HORMONES PLAY A KEY ROLE IN THE ESTABLISHMENT, ACTIVATION, AND REGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS. BY INFLUENCING THE RESPONSE AND SENSITIVITY TO RELEASING FACTORS, NEUROTRANSMITTERS, AND HORMONES, GONADAL STEROIDS HELP ORCHESTRATE THE GAIN OF THE HPA AXIS TO FINE-TUNE THE LEVELS OF STRESS HORMONES IN THE GENERAL CIRCULATION. FROM EARLY LIFE TO ADULTHOOD, GONADAL STEROIDS CAN DIFFERENTIALLY AFFECT THE HPA AXIS, RESULTING IN SEX DIFFERENCES IN THE RESPONSIVITY OF THIS AXIS. THE HPA AXIS INFLUENCES MANY PHYSIOLOGICAL FUNCTIONS MAKING AN ORGANISM'S RESPONSE TO CHANGES IN THE ENVIRONMENT APPROPRIATE FOR ITS REPRODUCTIVE STATUS. ALTHOUGH THE ACUTE HPA RESPONSE TO STRESSORS IS A BENEFICIAL RESPONSE, CONSTANT ACTIVATION OF THIS CIRCUITRY BY CHRONIC OR TRAUMATIC STRESSFUL EPISODES MAY LEAD TO A DYSREGULATION OF THE HPA AXIS AND CAUSE PATHOLOGY. COMPARED TO MALES, FEMALE MICE AND RATS SHOW A MORE ROBUST HPA AXIS RESPONSE, AS A RESULT OF CIRCULATING ESTRADIOL LEVELS WHICH ELEVATE STRESS HORMONE LEVELS DURING NON-THREATENING SITUATIONS, AND DURING AND AFTER STRESSORS. FLUCTUATING LEVELS OF GONADAL STEROIDS IN FEMALES ACROSS THE ESTROUS CYCLE ARE A MAJOR FACTOR CONTRIBUTING TO SEX DIFFERENCES IN THE ROBUSTNESS OF HPA ACTIVITY IN FEMALES COMPARED TO MALES. MOREOVER, GONADAL STEROIDS MAY ALSO CONTRIBUTE TO EPIGENETIC AND ORGANIZATIONAL INFLUENCES ON THE HPA AXIS EVEN BEFORE PUBERTY. CORRESPONDINGLY, CROSSTALK BETWEEN THE HYPOTHALAMIC-PITUITARY-GONADAL (HPG) AND HPA AXES COULD LEAD TO ABNORMALITIES OF STRESS RESPONSES. IN HUMANS, A DYSREGULATED STRESS RESPONSE IS ONE OF THE MOST COMMON SYMPTOMS SEEN ACROSS MANY NEUROPSYCHIATRIC DISORDERS, AND AS A RESULT, SUCH INTERACTIONS MAY EXACERBATE PERIPHERAL PATHOLOGIES. IN THIS REVIEW, WE DISCUSS THE HPA AND HPG AXES AND REVIEW HOW GONADAL STEROIDS INTERACT WITH THE HPA AXIS TO REGULATE THE STRESS CIRCUITRY DURING ALL STAGES IN LIFE. 2017 17 6388 33 THE ROLE OF SIRT1 IN THE BASOLATERAL AMYGDALA IN DEPRESSION-LIKE BEHAVIORS IN MICE. PREVIOUS INVESTIGATIONS HAVE IMPLICATED THE BASOLATERAL AMYGDALA (BLA) EPIGENETIC MECHANISMS IN THE PATHOPHYSIOLOGY OF DEPRESSION. SIRT1 IS A NAD+-DEPENDENT CLASS III HISTONE DEACETYLASE, WIDELY EXPRESSES IN BLA. HOWEVER, EPIGENETIC MECHANISMS IN THE BLA UNDER THE REGULATION OF SIRT1 IN THE DEPRESSION ARE LARGELY UNCHARACTERIZED. UNDER THE CHRONIC UNPREDICTABLE CHRONIC MILD STRESS (CUMS) MOUSE MODEL, WE USED ADENO-ASSOCIATED VIRAL VECTORS (AAV) THAT ENCODED SIRT1-SHRNA OR SIRT1 TO SPECIFICALLY KNOCKDOWN OR OVEREXPRESS SIRT1 IN BLA NEURONS, RESPECTIVELY. CUMS PROCEDURE INDUCED SIGNIFICANT DEPRESSION SYMPTOMS INCLUDING THE DECREASED SUCROSE PREFERENCE, THE LESS BODYWEIGHT GAINED, THE DECREASED IMMOBILE LATENCY AND THE INCREASED IMMOBILE TIME BOTH IN FORCED SWIM TEST (FST) AND TAIL SUSPENSION TEST (TST). KNOCKDOWN OF SIRT1 IN BLA GLUTAMATERGIC NEURONS REVERSED THESE DEPRESSION-LIKE BEHAVIORS AND RESTORED THE SYNAPTIC ABNORMALITIES. OVEREXPRESSION OF SIRT1 IN BLA GLUTAMATERGIC NEURONS INDUCED DEPRESSION-LIKE BEHAVIORS IN NON-STRESSED CONTROL MICE. THE RESULT OF PROTEIN EXPRESSIONS AND ULTRASTRUCTURAL CHANGES WERE CONSISTENT WITH THE BEHAVIORAL RESULTS. OUR STUDY SUGGESTED THAT DOWNREGULATION OF SIRT1 IN BLA HAS CERTAIN BENEFICIAL EFFECT ON CUMS-INDUCED DEPRESSION-LIKE BEHAVIORS SUCH AS ANOREXIA, ANHEDONIA, HOPELESSNESS AND DESPAIR. IN ADDITION, THE INCREASED EXPRESSION OF SIRT1 MAY BE THE IMMEDIATE CAUSE OF DEPRESSIVE-LIKE SYMPTOMS. THE ABNORMAL EXPRESSION OF SIRT1 MAY AFFECT THE TRANSCRIPTIONAL REGULATION MECHANISM AND SIGNALING PROTEIN ACETYLATION, AFFECTING NEUROPLASTICITY AND ULTIMATELY CONTRIBUTE TO MDD. IN THE STRESS-SUSCEPTIBLE MICE, THESE TWO MECHANISMS MAY CO-EXIST, BUT THE SPECIFIC MECHANISM NEEDS FURTHER RESEARCH. 2021 18 3462 37 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 19 886 34 CHRONIC CORTICOSTERONE EXPOSURE INCREASES EXPRESSION AND DECREASES DEOXYRIBONUCLEIC ACID METHYLATION OF FKBP5 IN MICE. THERE IS EVIDENCE FOR HYPERCORTISOLEMIA PLAYING A ROLE IN THE GENERATION OF PSYCHIATRIC SYMPTOMS AND FOR EPIGENETIC VARIATION WITHIN HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS GENES MEDIATING BEHAVIORAL CHANGES. WE TESTED THE HYPOTHESIS THAT EXPRESSION CHANGES WOULD BE INDUCED IN FKBP5 AND OTHER HPA AXIS GENES BY CHRONIC EXPOSURE TO CORTICOSTERONE AND THAT THESE CHANGES WOULD OCCUR THROUGH THE EPIGENETIC MECHANISM OF LOSS OR GAIN OF DNA METHYLATION (DNAM). WE ADMINISTERED CORTICOSTERONE (CORT) TO C57BL/6J MICE VIA THEIR DRINKING WATER FOR 4 WK AND TESTED FOR BEHAVIORAL AND PHYSIOLOGICAL CHANGES AND CHANGES IN GENE EXPRESSION LEVELS USING RNA EXTRACTED FROM HIPPOCAMPUS, HYPOTHALAMUS, AND BLOOD FOR THE FOLLOWING HPA GENES: FKBP5, NR3C1, HSP90, CRH, AND CRHR1. THE CORT MICE EXHIBITED ANXIETY-LIKE BEHAVIOR IN THE ELEVATED PLUS MAZE TEST. CHRONIC EXPOSURE TO CORT ALSO CAUSED A SIGNIFICANT DECREASE IN THE HIPPOCAMPAL AND BLOOD MRNA LEVELS OF NR3C1 AND A DECREASE IN HSP90 IN BLOOD AND CAUSED AN INCREASE IN FKBP5 FOR ALL TISSUES. DIFFERENCES WERE SEEN IN FKBP5 METHYLATION IN HIPPOCAMPUS AND HYPOTHALAMUS. TO ISOLATE A SINGLE-CELL TYPE, WE FOLLOWED UP WITH AN HT-22 MOUSE HIPPOCAMPAL NEURONAL CELL LINE EXPOSED TO CORT. AFTER 7 D, WE OBSERVED A 2.4-FOLD INCREASE IN FKBP5 EXPRESSION AND A DECREASE IN DNAM. IN THE CORT-TREATED MICE, WE ALSO OBSERVED CHANGES IN BLOOD DNAM IN FKBP5. OUR RESULTS SUGGEST DNAM PLAYS A ROLE IN MEDIATING EFFECTS OF GLUCOCORTICOID EXPOSURE ON FKBP5 FUNCTION, WITH POTENTIAL CONSEQUENCES FOR BEHAVIOR. 2010 20 3177 39 H3K9ME2 REGULATION OF BDNF EXPRESSION IN THE HIPPOCAMPUS AND MEDIAL PREFRONTAL CORTEX IS INVOLVED IN THE DEPRESSIVE-LIKE PHENOTYPE INDUCED BY MATERNAL SEPARATION IN MALE RATS. BACKGROUND: EARLY LIFE STRESS (ELS) INDUCES A DEPRESSIVE-LIKE PHENOTYPE AND INCREASES THE RISK OF DEPRESSION. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) HAS BEEN CONFIRMED TO BE INVOLVED IN THE PATHOPHYSIOLOGY OF DEPRESSION. HOWEVER, THE MECHANISM BY WHICH ELS ALTERS THE EPIGENETIC REGULATION OF BDNF AND CHANGES SUSCEPTIBILITY TO DEPRESSION HAS NOT BEEN FULLY CLARIFIED. METHODS: THE PRESENT STUDY USED MATERNAL SEPARATION (MS) AND CHRONIC UNPREDICTED MILD STRESS (CUMS) TO ESTABLISH AN MS ANIMAL MODEL AND A DEPRESSIVE ANIMAL MODEL. WE ASSESSED DEPRESSIVE-LIKE BEHAVIOURS, INCLUDING ANHEDONIA, LOCOMOTOR ACTIVITY, ANXIETY-LIKE BEHAVIOUR, AND SPATIAL MEMORY, USING THE SUCROSE PREFERENCE TEST, THE OPEN FIELD TEST, THE ELEVATED PLUS MAZE TEST, AND THE MORRIS WATER MAZE TEST. WE ALSO INVESTIGATED BDNF AND H3K9ME2 EXPRESSION IN THE HIPPOCAMPUS AND MEDIAL PREFRONTAL CORTEX (MPFC) BY IMMUNOHISTOCHEMISTRY, WESTERN BLOTTING, AND QPCR ANALYSIS. ADDITIONALLY, WE USED UNC0642, A SMALL MOLECULE INHIBITOR OF HISTONE METHYLTRANSFERASE (G9A), AS AN INTERVENTION. RESULTS: THE RESULTS SHOWED THAT CUMS INDUCED DEPRESSIVE-LIKE BEHAVIOURS IN RATS AND RESULTED IN INCREASED H3K9ME2 EXPRESSION AND DECREASED BDNF EXPRESSION IN THE HIPPOCAMPUS AND MPFC. MORE IMPORTANTLY, ADULT MS RATS EXPERIENCING CUMS HAD MORE SEVERE DEPRESSIVE BEHAVIOURS, HAD HIGHER EXPRESSION OF H3K9ME2 IN THE HIPPOCAMPUS AND MPFC, AND HAD LOWER EXPRESSION OF BDNF IN THE HIPPOCAMPUS AND MPFC. IN ADDITION, ADMINISTRATION OF THE G9A INHIBITOR REVERSED MOST OF THE CHANGES. CONCLUSIONS: OUR STUDY SUGGESTS THAT ELS CHANGED BDNF AND H3K9ME2 EXPRESSION IN THE RAT BRAIN, RESULTING IN A DEPRESSIVE-LIKE PHENOTYPE. 2021