1 4222 108 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 2 2371 39 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 3 4118 29 MECHANISMS OF BRAIN GLUCOCORTICOID RESISTANCE IN STRESS-INDUCED PSYCHOPATHOLOGIES. EXPOSURE TO STRESS ACTIVATES THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS AND LEADS TO INCREASED LEVELS OF GLUCOCORTICOID (GC) HORMONES. PROLONGED ELEVATION OF GC LEVELS CAUSES NEURONAL DYSFUNCTION, DECREASES THE DENSITY OF SYNAPSES, AND IMPAIRS NEURONAL PLASTICITY. DECREASED SENSITIVITY TO GLUCOCORTICOIDS (GLUCOCORTICOID RESISTANCE) THAT DEVELOPS AS A RESULT OF CHRONIC STRESS IS ONE OF THE CHARACTERISTIC FEATURES OF STRESS-INDUCED PSYCHOPATHOLOGIES. IN THIS ARTICLE, WE REVIEWED THE PUBLISHED DATA ON PROPOSED MOLECULAR MECHANISMS THAT CONTRIBUTE TO THE DEVELOPMENT OF GLUCOCORTICOID RESISTANCE IN BRAIN, INCLUDING CHANGES IN THE EXPRESSION OF THE GLUCOCORTICOID RECEPTOR (GR) GENE, BIOSYNTHESIS OF GR ISOFORMS, AND GR POSTTRANSLATIONAL MODIFICATIONS. WE ALSO PRESENT DATA ON ALTERATIONS IN THE EXPRESSION OF THE FKBP5 GENE ENCODING THE MAIN COMPONENT OF CELL ULTRA-SHORT NEGATIVE FEEDBACK LOOP OF GC SIGNALING REGULATION. RECENT DISCOVERIES ON STRESS- AND GR-INDUCED CHANGES IN EPIGENETIC MODIFICATION PATTERNS AS WELL AS NORMALIZING ACTION OF ANTIDEPRESSANTS ARE DISCUSSED. GR AND FKBP5 GENE POLYMORPHISMS ASSOCIATED WITH STRESS-INDUCED PSYCHOPATHOLOGIES ARE DESCRIBED, AND THEIR ROLE IN GLUCOCORTICOID RESISTANCE IS DISCUSSED. 2017 4 2905 30 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 5 1752 37 EARLY LIFE STRESS RESTRICTS TRANSLATIONAL REACTIVITY IN CA3 NEURONS ASSOCIATED WITH ALTERED STRESS RESPONSES IN ADULTHOOD. EARLY LIFE EXPERIENCES PROGRAM BRAIN STRUCTURE AND FUNCTION AND CONTRIBUTE TO BEHAVIORAL ENDOPHENOTYPES IN ADULTHOOD. EPIGENETIC CONTROL OF GENE EXPRESSION BY THOSE EXPERIENCES AFFECT DISCRETE BRAIN REGIONS INVOLVED IN MOOD, COGNITIVE FUNCTION AND REGULATION OF HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS. IN RODENTS, ACUTE RESTRAINT STRESS INCREASES THE EXPRESSION OF THE REPRESSIVE HISTONE H3 LYSINE 9 TRI-METHYLATION (H3K9ME3) IN HIPPOCAMPAL FIELDS, INCLUDING THE CA3 PYRAMIDAL NEURONS. THESE CA3 NEURONS ARE CRUCIALLY INVOLVED IN COGNITIVE FUNCTION AND MOOD REGULATION AS WELL AS ACTIVATION OF GLUCOCORTICOID (CORT) SECRETION. CA3 NEURONS ALSO EXHIBIT STRUCTURAL AND FUNCTIONAL CHANGES AFTER EARLY-LIFE STRESS (ELS) AS WELL AS AFTER CHRONIC STRESS IN ADULTHOOD. USING A PROTOCOL OF CHRONIC ELS INDUCED BY LIMITED BEDDING AND NESTING MATERIAL FOLLOWED BY ACUTE-SWIM STRESS (AS) IN ADULTHOOD, WE SHOW THAT MICE WITH A HISTORY OF ELS DISPLAY A BLUNTED CORT RESPONSE TO AS, DESPITE EXHIBITING ACTIVATION OF IMMEDIATE EARLY GENES AFTER STRESS SIMILAR TO THAT FOUND IN CONTROL MICE. WE FIND THAT ELS INDUCED PERSISTENTLY INCREASED EXPRESSION OF THE REPRESSIVE H3K9ME3 HISTONE MARK IN THE CA3 SUBFIELD AT BASELINE THAT WAS SUBSEQUENTLY DECREASED FOLLOWING AS. IN CONTRAST, AS INDUCED A TRANSIENT INCREASE OF THIS MARK IN CONTROL MICE. USING TRANSLATING RIBOSOME AFFINITY PURIFICATION (TRAP) METHOD TO ISOLATE CA3 TRANSLATING MRNAS, WE FOUND THAT EXPRESSION OF GENES OF THE EPIGENETIC GENE FAMILY, GABA/GLUTAMATE FAMILY, AND GLUCOCORTICOID RECEPTORS BINDING GENES WERE DECREASED TRANSIENTLY IN CONTROL MICE BY AS AND SHOWED A PERSISTENT REDUCTION IN ELS MICE. IN MOST CASES, AS IN ELS MICE DID NOT INDUCE GENE EXPRESSION CHANGES. A STRINGENT FILTERING OF GENES AFFECTED BY AS IN CONTROL AND ELS MICE REVEALED A NOTEWORTHY DECREASE IN GENE EXPRESSION CHANGE IN ELS MICE COMPARED TO CONTROL. ONLY 18 GENES WERE SELECTIVELY REGULATED BY AS IN ELS MICE AND ENCOMPASSED PATHWAYS SUCH AS CIRCADIAN RHYTHM, INFLAMMATORY RESPONSE, OPIOID RECEPTORS, AND MORE GENES INCLUDED IN THE GLUCOCORTICOID RECEPTOR BINDING FAMILY. THUS, ELS PROGRAMS A RESTRICTED TRANSLATIONAL RESPONSE TO STRESS IN STRESS-SENSITIVE CA3 NEURONS LEADING TO PERSISTENT CHANGES IN GENE EXPRESSION, SOME OF WHICH MIMIC THE TRANSIENT EFFECTS OF AS IN CONTROL MICE, WHILE LEAVING IN OPERATION THE IMMEDIATE EARLY GENE RESPONSE TO AS. 2019 6 3412 34 HPA AXIS REGULATION AND EPIGENETIC PROGRAMMING OF IMMUNE-RELATED GENES IN CHRONICALLY STRESSED AND NON-STRESSED MID-LIFE WOMEN. HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS DYSREGULATION HAS BEEN ASSOCIATED WITH ALTERED IMMUNE FUNCTION, BUT THE UNDERLYING MOLECULAR MECHANISMS ARE UNCLEAR. EPIGENETIC PROCESSES, INCLUDING DNA METHYLATION, RESPOND TO THE GLUCOCORTICOID END-PRODUCTS OF THE HPA AXIS (CORTISOL IN HUMANS) AND COULD BE INVOLVED IN THIS NEUROENDOCRINE-IMMUNE CROSSTALK. HERE WE EXAMINED THE EXTENT TO WHICH VARIATIONS IN HPA AXIS REGULATION ARE ASSOCIATED WITH PERIPHERAL BLOOD DNA (CPG) METHYLATION CHANGES IN 57 CHRONICALLY STRESSED CAREGIVERS AND 67 CONTROL WOMEN. DNA METHYLATION WAS DETERMINED WITH THE ILLUMINA 450K ARRAY FOR A PANEL OF GENES INVOLVED IN HPA AXIS AND IMMUNE FUNCTION. HPA AXIS FEEDBACK WAS ASSESSED WITH THE LOW-DOSE DEXAMETHASONE SUPPRESSION TEST (DST), MEASURING THE EXTENT TO WHICH CORTISOL SECRETION IS SUPPRESSED BY THE SYNTHETIC GLUCOCORTICOID DEXAMETHASONE. AFTER MULTIPLE TESTING CORRECTION IN THE ENTIRE COHORT, HIGHER POST-DST CORTISOL, REFLECTING BLUNTED HPA AXIS NEGATIVE FEEDBACK, BUT NOT BASELINE WAKING CORTISOL, WAS ASSOCIATED WITH LOWER DNA METHYLATION AT EIGHT TNF AND TWO FKBP5 CPG SITES. CAREGIVER GROUP STATUS WAS ASSOCIATED WITH LOWER METHYLATION AT TWO IL6 CPG SITES. SINCE ASSOCIATIONS WERE MOST ROBUST WITH TNF METHYLATION (32% OF THE 450K-COVERED SITES), WE FURTHER EXAMINED FUNCTIONALITY OF THIS EPIGENETIC SIGNATURE IN CULTURED PERIPHERAL BLOOD MONONUCLEAR CELLS IN 33 PARTICIPANTS; INTRIGUINGLY, LOWER TNF METHYLATION RESULTED IN HIGHER EX VIVO TNF MRNA FOLLOWING IMMUNE STIMULATION. TAKEN TOGETHER, OUR FINDINGS LINK CHRONIC STRESS AND HPA AXIS REGULATION WITH EPIGENETIC SIGNATURES AT IMMUNE-RELATED GENES, THEREBY PROVIDING NOVEL INSIGHTS INTO HOW ABERRANT HPA AXIS FUNCTION MAY CONTRIBUTE TO HEIGHTENED INFLAMMATION AND DISEASE RISK. 2021 7 997 27 CHRONIC STRESS-DRIVEN GLUCOCORTICOID RECEPTOR ACTIVATION PROGRAMS KEY CELL PHENOTYPES AND FUNCTIONAL EPIGENOMIC PATTERNS IN HUMAN FIBROBLASTS. CHRONIC ENVIRONMENTAL STRESS CAN PROFOUNDLY IMPACT CELL AND BODY FUNCTION. ALTHOUGH THE UNDERLYING MECHANISMS ARE POORLY UNDERSTOOD, EPIGENETICS HAS EMERGED AS A KEY LINK BETWEEN ENVIRONMENT AND HEALTH. THE GENOMIC EFFECTS OF STRESS ARE THOUGHT TO BE MEDIATED BY THE ACTION OF GLUCOCORTICOID STRESS HORMONES, PRIMARILY CORTISOL IN HUMANS, WHICH ACT VIA THE GLUCOCORTICOID RECEPTOR (GR). TO DISSECT HOW CHRONIC STRESS-DRIVEN GR ACTIVATION INFLUENCES EPIGENETIC AND CELL STATES, HUMAN FIBROBLASTS UNDERWENT PROLONGED EXPOSURE TO PHYSIOLOGICAL STRESS LEVELS OF CORTISOL AND/OR A SELECTIVE GR ANTAGONIST. CORTISOL WAS FOUND TO DRIVE ROBUST CHANGES IN CELL PROLIFERATION, MIGRATION, AND MORPHOLOGY, WHICH WERE ABROGATED BY CONCOMITANT GR BLOCKADE. THE GR-DRIVEN CELL PHENOTYPES WERE ACCOMPANIED BY WIDESPREAD, YET GENOMIC CONTEXT-DEPENDENT, CHANGES IN DNA METHYLATION AND MRNA EXPRESSION, INCLUDING GENE LOCI WITH KNOWN ROLES IN CELL PROLIFERATION AND MIGRATION. THESE FINDINGS PROVIDE INSIGHTS INTO HOW CHRONIC STRESS-DRIVEN FUNCTIONAL EPIGENOMIC PATTERNS BECOME ESTABLISHED TO SHAPE KEY CELL PHENOTYPES. 2022 8 1903 36 ENHANCED NEUROINFLAMMATION MEDIATED BY DNA METHYLATION OF THE GLUCOCORTICOID RECEPTOR TRIGGERS COGNITIVE DYSFUNCTION AFTER SEVOFLURANE ANESTHESIA IN ADULT RATS SUBJECTED TO MATERNAL SEPARATION DURING THE NEONATAL PERIOD. BACKGROUND: MOUNTING EVIDENCE INDICATES THAT CHILDREN WHO EXPERIENCE ABUSE AND NEGLECT ARE PRONE TO CHRONIC DISEASES AND PREMATURE MORTALITY LATER IN LIFE. ONE MECHANISTIC HYPOTHESIS FOR THIS PHENOMENON IS THAT EARLY LIFE ADVERSITY ALTERS THE EXPRESSION OR FUNCTIONING OF THE GLUCOCORTICOID RECEPTOR (GR) THROUGHOUT THE COURSE OF LIFE AND THEREBY INCREASES SENSITIVITY TO INFLAMMATORY STIMULATION. AN EXAGGERATED PRO-INFLAMMATORY RESPONSE IS GENERALLY CONSIDERED TO BE A KEY CAUSE OF POSTOPERATIVE COGNITIVE DYSFUNCTION (POCD). THE AIM OF THIS STUDY WAS TO EXAMINE THE EFFECTS OF EARLY LIFE ADVERSITY ON COGNITIVE FUNCTION AND NEUROINFLAMMATION AFTER SEVOFLURANE ANESTHESIA IN ADULT RATS AND TO DETERMINE WHETHER SUCH EFFECTS ARE ASSOCIATED WITH THE EPIGENETIC REGULATION OF GR. METHODS: WISTAR RAT PUPS WERE REPEATEDLY SUBJECTED TO INFANT MATERNAL SEPARATION (EARLY LIFE STRESS) FROM POSTNATAL DAYS 2-21. IN ADULTHOOD, THEIR BEHAVIOR AND THE SIGNALING OF HIPPOCAMPAL PRO-INFLAMMATORY FACTORS AND NUCLEAR FACTOR-KAPPA B (NF-KAPPAB) AFTER SEVOFLURANE ANESTHESIA WERE EVALUATED. WE ALSO EXAMINED THE EFFECTS OF MATERNAL SEPARATION (MS) ON THE EXPRESSION OF GR AND THE DNA METHYLATION STATUS OF THE PROMOTER REGION OF EXON 1(7) OF GR AND WHETHER BEHAVIORAL CHANGES AND NEUROINFLAMMATION AFTER ANESTHESIA WERE REVERSIBLE WHEN THE EXPRESSION OF GR WAS INCREASED BY ALTERING DNA METHYLATION. RESULTS: MS INDUCED COGNITIVE DECLINE AFTER SEVOFLURANE INHALATION IN THE MORRIS WATER MAZE AND CONTEXT FEAR CONDITIONING TESTS AND ENHANCED THE RELEASE OF CYTOKINES AND THE ACTIVATION OF ASTROCYTE INTRACELLULAR NF-KAPPAB SIGNALING INDUCED BY SEVOFLURANE IN THE HIPPOCAMPUS OF ADULT RATS. BLOCKING NF-KAPPAB SIGNALING BY PYRROLIDINE DITHIOCARBAMATE (PDTC) INHIBITED THE RELEASE OF CYTOKINES. MS ALSO REDUCED THE EXPRESSION OF GR AND UPREGULATED THE METHYLATION LEVELS OF THE PROMOTER REGION OF GR EXON 1(7), AND SUCH EFFECTS WERE REVERSED BY TREATMENT WITH THE HISTONE DEACETYLASE INHIBITOR TRICHOSTATIN A (TSA) IN ADULT RATS. MOREOVER, TSA TREATMENT IN ADULT MS RATS INHIBITED THE OVERACTIVATION OF ASTROCYTE INTRACELLULAR NF-KAPPAB SIGNALING AND THE RELEASE OF CYTOKINES AND ALLEVIATED COGNITIVE DYSFUNCTION AFTER SEVOFLURANE ANESTHESIA. CONCLUSIONS: EARLY LIFE STRESS INDUCES COGNITIVE DYSFUNCTION AFTER SEVOFLURANE ANESTHESIA, PERHAPS DUE TO THE ABERRANT METHYLATION OF THE GR GENE PROMOTER, WHICH REDUCES THE EXPRESSION OF THE GR GENE AND FACILITATES EXAGGERATED INFLAMMATORY RESPONSES. 2017 9 887 24 CHRONIC CORTISOL EXPOSURE IN EARLY DEVELOPMENT LEADS TO NEUROENDOCRINE DYSREGULATION IN ADULTHOOD. OBJECTIVE: CHRONIC EARLY LIFE STRESS CAN AFFECT DEVELOPMENT OF THE NEUROENDOCRINE STRESS SYSTEM, LEADING TO ITS PERSISTENT DYSREGULATION AND CONSEQUENTLY INCREASED DISEASE RISK IN ADULTHOOD. ONE CONTRIBUTING FACTOR IS THOUGHT TO BE EPIGENETIC PROGRAMMING IN RESPONSE TO CHRONIC CORTISOL EXPOSURE DURING EARLY DEVELOPMENT. WE HAVE PREVIOUSLY SHOWN THAT ZEBRAFISH EMBRYOS TREATED CHRONICALLY WITH CORTISOL DEVELOP INTO ADULTS WITH CONSTITUTIVELY ELEVATED WHOLE-BODY CORTISOL AND ABERRANT IMMUNE GENE EXPRESSION. HERE WE FURTHER CHARACTERIZE THAT PHENOTYPE BY ASSESSING PERSISTENT EFFECTS OF THE TREATMENT ON CORTISOL TISSUE DISTRIBUTION AND DYNAMICS, CHROMATIN ACCESSIBILITY, AND ACTIVITIES OF GLUCOCORTICOID-RESPONSIVE REGULATORY GENES KLF9 AND FKBP5. TO THAT END CORTISOL LEVELS IN DIFFERENT TISSUES OF FED AND FASTED ADULTS WERE MEASURED USING ELISA, OPEN CHROMATIN IN ADULT BLOOD CELLS WAS MAPPED USING ATAC-SEQ, AND GENE ACTIVITY IN ADULT BLOOD AND BRAIN CELLS WAS MEASURED USING QRT-PCR. RESULTS: ADULTS DERIVED FROM CORTISOL-TREATED EMBRYOS HAVE ELEVATED WHOLE-BODY CORTISOL WITH ABERRANTLY REGULATED TISSUE DISTRIBUTION AND DYNAMICS THAT CORRELATE WITH DIFFERENTIAL ACTIVITY OF KLF9 AND FKBP5 IN BLOOD AND BRAIN. 2020 10 5160 33 PREADOLESCENT ADVERSITY PROGRAMS A DISRUPTED MATERNAL STRESS REACTIVITY IN HUMANS AND MICE. BACKGROUND: ADVERSE CHILDHOOD EXPERIENCES (ACES) ARE ONE OF THE GREATEST PREDICTORS OF AFFECTIVE DISORDERS FOR WOMEN. PERIODS OF DYNAMIC HORMONAL FLUX, INCLUDING PREGNANCY, EXACERBATE THE RISK FOR AFFECTIVE DISTURBANCE AND PROMOTE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS DYSREGULATION, A KEY FEATURE OF AFFECTIVE DISORDERS. LITTLE IS UNDERSTOOD AS TO HOW STRESS EXPERIENCED IN LATE CHILDHOOD, DEFINED AS PREADOLESCENCE, ALTERS THE PROGRAMMING UNIQUE TO THIS PERIOD OF BRAIN MATURATION AND ITS INTERACTION WITH THE HORMONAL CHANGES OF PREGNANCY AND POSTPARTUM. METHODS: PREADOLESCENT FEMALE MICE WERE EXPOSED TO CHRONIC STRESS AND EXAMINED FOR CHANGES IN THEIR HPA AXIS DURING PREGNANCY AND POSTPARTUM, INCLUDING ASSESSMENT OF MATERNAL-SPECIFIC STRESS RESPONSIVENESS AND TRANSCRIPTOMICS OF THE PARAVENTRICULAR NUCLEUS OF THE HYPOTHALAMUS. TRANSLATIONALLY, PREGNANT WOMEN WITH LOW OR HIGH ACES WERE EXAMINED FOR THEIR MATERNAL STRESS RESPONSIVENESS. RESULTS: AS PREDICTED, PREADOLESCENT STRESS IN MICE RESULTED IN A SIGNIFICANT BLUNTING OF THE CORTICOSTERONE RESPONSE DURING PREGNANCY. TRANSCRIPTOMIC ANALYSIS OF THE PARAVENTRICULAR NUCLEUS REVEALED WIDESPREAD CHANGES IN EXPRESSION OF IMMEDIATE EARLY GENES AND THEIR TARGETS, SUPPORTING THE LIKELY INVOLVEMENT OF AN UPSTREAM EPIGENETIC MECHANISM. CRITICALLY, IN OUR HUMAN STUDIES, THE HIGH ACE WOMEN SHOWED A SIGNIFICANT BLUNTING OF THE HPA RESPONSE. CONCLUSIONS: THIS UNIQUE MOUSE MODEL RECAPITULATES A CLINICAL OUTCOME OF A HYPORESPONSIVE HPA STRESS AXIS, AN IMPORTANT FEATURE OF AFFECTIVE DISORDERS, DURING A DYNAMIC HORMONAL PERIOD, AND SUGGESTS INVOLVEMENT OF TRANSCRIPTIONAL REGULATION IN THE HYPOTHALAMUS. THESE STUDIES IDENTIFY A NOVEL MOUSE MODEL OF FEMALE ACES THAT CAN BE USED TO EXAMINE HOW ADDITIONAL LIFE ADVERSITY MAY PROVOKE DISEASE RISK OR RESILIENCE. 2017 11 2740 27 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 12 3080 32 GENOME-WIDE METHYLATION IN ALCOHOL USE DISORDER SUBJECTS: IMPLICATIONS FOR AN EPIGENETIC REGULATION OF THE CORTICO-LIMBIC GLUCOCORTICOID RECEPTORS (NR3C1). ENVIRONMENTAL FACTORS, INCLUDING SUBSTANCE ABUSE AND STRESS, CAUSE LONG-LASTING CHANGES IN THE REGULATION OF GENE EXPRESSION IN THE BRAIN VIA EPIGENETIC MECHANISMS, SUCH AS DNA METHYLATION. WE EXAMINED GENOME-WIDE DNA METHYLATION PATTERNS IN THE PREFRONTAL CORTEX (PFC, BA10) OF 25 PAIRS OF CONTROL AND INDIVIDUALS WITH ALCOHOL USE DISORDER (AUD), USING THE INFINIUM((R)) METHYLATIONEPIC BEADCHIP. WE IDENTIFIED 5254 DIFFERENTIALLY METHYLATED CPGS (P(NOMINAL) < 0.005). BIOINFORMATIC ANALYSES HIGHLIGHTED BIOLOGICAL PROCESSES CONTAINING GENES RELATED TO STRESS ADAPTATION, INCLUDING THE GLUCOCORTICOID RECEPTOR (ENCODED BY NR3C1). CONSIDERING THAT ALCOHOL IS A STRESSOR, WE FOCUSED OUR ATTENTION ON DIFFERENTIALLY METHYLATED REGIONS OF THE NR3C1 GENE AND VALIDATED THE DIFFERENTIAL METHYLATION OF SEVERAL GENES IN THE NR3C1 NETWORK. CHRONIC ALCOHOL DRINKING RESULTS IN A SIGNIFICANT INCREASED METHYLATION OF THE NR3C1 EXON VARIANT 1(H), WITH A PARTICULAR INCREASE IN THE LEVELS OF 5-HYDROXYMETHYLCYTOSINE OVER 5-METHYLCYTOSINE. THESE CHANGES IN DNA METHYLATION WERE ASSOCIATED WITH REDUCED NR3C1 MRNA AND PROTEIN EXPRESSION LEVELS IN PFC, AS WELL AS OTHER CORTICO-LIMBIC REGIONS OF AUD SUBJECTS WHEN COMPARED WITH CONTROLS. FURTHERMORE, WE SHOW THAT THE EXPRESSION OF SEVERAL STRESS-RESPONSIVE GENES (E.G., CRF, POMC, AND FKBP5) IS ALTERED IN THE PFC OF AUD SUBJECTS. THESE STRESS-RESPONSE GENES WERE ALSO CHANGED IN THE HIPPOCAMPUS, A REGION THAT IS HIGHLY SUSCEPTIBLE TO STRESS. THESE DATA SUGGEST THAT ALCOHOL-DEPENDENT ABERRANT DNA METHYLATION OF NR3C1 AND CONSEQUENT CHANGES IN OTHER STRESS-RELATED GENES MIGHT BE FUNDAMENTAL IN THE PATHOPHYSIOLOGY OF AUD AND LAY THE GROUNDWORK FOR TREATMENTS TARGETING THE EPIGENETIC MECHANISMS REGULATING NR3C1 IN AUD. 2021 13 5834 28 STRESS-INDUCED VISCERAL PAIN IN FEMALE RATS IS ASSOCIATED WITH EPIGENETIC REMODELING IN THE CENTRAL NUCLEUS OF THE AMYGDALA. STRESS AND ANXIETY CONTRIBUTE TO THE PATHOPHYSIOLOGY OF IRRITABLE BOWEL SYNDROME (IBS), A FEMALE-PREDOMINANT DISORDER OF THE GUT-BRAIN AXIS, CHARACTERIZED BY ABDOMINAL PAIN DUE TO HEIGHTENED VISCERAL SENSITIVITY. IN THE CURRENT STUDY, WE AIMED TO EVALUATE IN FEMALE RATS WHETHER EPIGENETIC REMODELING IN THE LIMBIC BRAIN, SPECIFICALLY IN THE CENTRAL NUCLEUS OF THE AMYGDALA (CEA), IS A CONTRIBUTING FACTOR IN STRESS-INDUCED VISCERAL HYPERSENSITIVITY. OUR RESULTS SHOWED THAT 1 H EXPOSURE TO WATER AVOIDANCE STRESS (WAS) FOR 7 CONSECUTIVE DAYS DECREASED HISTONE ACETYLATION AT THE GR PROMOTER AND INCREASED HISTONE ACETYLATION AT THE CRH PROMOTER IN THE CEA. CHANGES IN HISTONE ACETYLATION WERE MEDIATED BY THE HISTONE DEACETYLASE (HDAC) SIRT-6 AND THE HISTONE ACETYLTRANSFERASE CBP, RESPECTIVELY. ADMINISTRATION OF THE HDAC INHIBITOR TRICHOSTATIN A (TSA) INTO THE CEA PREVENTED STRESS-INDUCED VISCERAL HYPERSENSITIVITY THROUGH BLOCKADE OF SIRT-6 MEDIATED HISTONE ACETYLATION AT THE GR PROMOTER. IN ADDITION, HDAC INHIBITION WITHIN THE CEA PREVENTED STRESS-INDUCED HISTONE ACETYLATION OF THE CRH PROMOTER. OUR RESULTS SUGGEST THAT, IN FEMALES, EPIGENETIC MODIFICATIONS IN THE LIMBIC BRAIN REGULATING GR AND CRH EXPRESSION CONTRIBUTE TO STRESS-INDUCED VISCERAL HYPERSENSITIVITY AND OFFER A POTENTIAL EXPLANATION OF HOW STRESS CAN TRIGGER SYMPTOMS IN IBS PATIENTS. 2021 14 989 25 CHRONIC SOCIAL DEFEAT STRESS DIFFERENTIALLY REGULATES THE EXPRESSION OF BDNF TRANSCRIPTS AND EPIGENETIC MODIFYING ENZYMES IN SUSCEPTIBLE AND RESILIENT MICE. OBJECTIVES: ALTHOUGH STRESS IS CONSIDERED A PRIMARY RISK FACTOR FOR NEUROPSYCHIATRIC DISORDERS, A MAJORITY OF INDIVIDUALS ARE RESILIENT TO THE EFFECTS OF STRESS EXPOSURE AND SUCCESSFULLY ADAPT TO ADVERSE LIFE EVENTS, WHILE OTHERS, THE SO-CALLED SUSCEPTIBLE INDIVIDUALS, MAY HAVE PROBLEMS TO PROPERLY ADAPT TO ENVIRONMENTAL CHANGES. HOWEVER, THE MECHANISMS UNDERLYING THESE DIFFERENT RESPONSES TO STRESS EXPOSURE ARE POORLY UNDERSTOOD.METHODS: ADULT MALE C57BL/6J MICE WERE EXPOSED TO CHRONIC SOCIAL DEFEAT STRESS PROTOCOL AND LEVELS OF BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) TRANSCRIPTS AND EPIGENETIC MODIFYING ENZYMES WERE ANALYSED BY REAL-TIME PCR IN THE HIPPOCAMPUS (HPC) AND PREFRONTAL CORTEX (PFC) OF SUSCEPTIBLE AND RESILIENT MICE.RESULTS: WE FOUND A SELECTIVE REDUCTION OF BDNF-6 TRANSCRIPT IN THE HPC AND AN INCREASE OF BDNF-4 TRANSCRIPT IN THE PFC OF SUSCEPTIBLE MICE. MOREOVER, SUSCEPTIBLE MICE SHOWED A SELECTIVE REDUCTION OF THE G9A MRNA LEVELS IN THE HPC, WHILE HDAC-5 AND DNMT3A MRNA LEVELS WERE SPECIFICALLY REDUCED IN THE PFC.CONCLUSIONS: OVERALL, OUR RESULTS, SHOWING A DIFFERENT EXPRESSION OF BDNF TRANSCRIPTS AND EPIGENETIC MODIFYING ENZYMES IN SUSCEPTIBLE AND RESILIENT MICE, SUGGEST THAT STRESS RESILIENCE IS NOT SIMPLY A LACK OF ACTIVATION OF STRESS-RELATED PATHWAYS, BUT IS RELATED TO THE ACTIVATION OF ADDITIONAL DIFFERENT SPECIFIC MECHANISMS. 2019 15 5815 37 STRESS AND GLUCOCORTICOID RECEPTOR TRANSCRIPTIONAL PROGRAMMING IN TIME AND SPACE: IMPLICATIONS FOR THE BRAIN-GUT AXIS. BACKGROUND: CHRONIC PSYCHOLOGICAL STRESS IS ASSOCIATED WITH ENHANCED ABDOMINAL PAIN AND ALTERED INTESTINAL BARRIER FUNCTION THAT MAY RESULT FROM A PERTURBATION IN THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS. THE GLUCOCORTICOID RECEPTOR (GR) EXPLOITS DIVERSE MECHANISMS TO ACTIVATE OR SUPPRESS CONGENERIC GENE EXPRESSION, WITH REGULATORY VARIATION ASSOCIATED WITH STRESS-RELATED DISORDERS IN PSYCHIATRY AND GASTROENTEROLOGY. PURPOSE: DURING ACUTE AND CHRONIC STRESS, CORTICOTROPIN-RELEASING HORMONE DRIVES SECRETION OF ADRENOCORTICOTROPIC HORMONE FROM THE PITUITARY, ULTIMATELY LEADING TO THE RELEASE OF CORTISOL (HUMAN) AND CORTICOSTERONE (RODENT) FROM THE ADRENAL GLANDS. CORTISOL BINDS WITH THE GR IN THE CYTOSOL, TRANSLOCATES TO THE NUCLEUS, AND ACTIVATES THE NR3C1 (NUCLEAR RECEPTOR SUBFAMILY 3, GROUP C, MEMBER 1 [GR]) GENE. THIS REVIEW FOCUSES ON THE RAPIDLY DEVELOPING OBSERVATIONS THAT CORTISOL IS RESPONSIBLE FOR DRIVING CIRCADIAN AND ULTRADIAN BURSTS OF TRANSCRIPTIONAL ACTIVITY IN THE CLOCK (CLOCK CIRCADIAN REGULATOR) AND PER (PERIOD CIRCADIAN CLOCK 1) GENE FAMILIES, AND THIS RHYTHM IS DISRUPTED IN MAJOR DEPRESSIVE DISORDER, BIPOLAR DISORDER, AND STRESS-RELATED GASTROINTESTINAL AND IMMUNE DISORDERS. GLUCOCORTICOID RECEPTOR REGULATES DIFFERENT SETS OF TRANSCRIPTS IN A TISSUE-SPECIFIC MANNER, THROUGH PULSATILE WAVES OF GENE EXPRESSION THAT INCLUDES OCCUPANCY OF GLUCOCORTICOID RESPONSE ELEMENTS LOCATED WITHIN CONSTITUTIVELY OPEN SPATIAL DOMAINS IN CHROMATIN. EMERGING EVIDENCE SUPPORTS A POTENTIALLY PIVOTAL ROLE FOR EPIGENETIC REGULATION OF HOW GR INTERACTS WITH OTHER CHROMATIN REGULATORS TO CONTROL THE EXPRESSION OF ITS TARGET GENES. DYSREGULATION OF THE CENTRAL AND PERIPHERAL GR REGULOME HAS POTENTIALLY SIGNIFICANT CONSEQUENCES FOR STRESS-RELATED DISORDERS AFFECTING THE BRAIN-GUT AXIS. 2016 16 3978 32 LONG-TERM EFFECTS OF PRENATAL SEVERE HYPOXIA ON CENTRAL AND PERIPHERAL COMPONENTS OF THE GLUCOCORTICOID SYSTEM IN RATS. INTRODUCTION: PRENATAL HYPOXIA IS A RISK FACTOR FOR THE DEVELOPMENT OF NUMEROUS NEUROLOGICAL DISORDERS. IT IS KNOWN THAT THE MATERNAL STRESS RESPONSE TO HYPOXIA DETERMINES THE EPIGENETIC IMPAIRMENT OF THE PERINATAL EXPRESSION OF GLUCOCORTICOID RECEPTORS (GR) IN THE HIPPOCAMPUS OF THE PROGENY, BUT SO FAR NO DETAILED STUDY OF HOW THIS AFFECTS THE FUNCTIONAL STATE OF THE GLUCOCORTICOID SYSTEM DURING FURTHER ONTOGENESIS HAS BEEN PERFORMED. OBJECTIVE: THE GOAL OF THE PRESENT STUDY WAS TO EXAMINE THE LONG-TERM EFFECTS OF THE PRENATAL HYPOXIA ON THE FUNCTIONING OF THE GLUCOCORTICOID SYSTEM THROUGHOUT LIFE. METHODS: PRENATAL SEVERE HYPOBARIC HYPOXIA (PSH) WAS INDUCED IN THE CRITICAL PERIOD OF EMBRYONIC HIPPOCAMPAL FORMATION ON DAYS 14-16 OF GESTATION IN A HYPOBARIC CHAMBER (180 TORR, 5% OXYGEN, 3 H). THE ACTIVITY OF CENTRAL (HIPPOCAMPUS) AND PERIPHERAL (LIVER) COMPONENTS OF THE GLUCOCORTICOID SYSTEM WAS ASSESSED IN 1-DAY-OLD (NEWBORN), 2-WEEK-OLD (JUVENILE), 3-MONTH-OLD (ADULT), AND 18-MONTH-OLD (AGED) MALE RATS. RESULTS: THE PSH RESULTED IN CONTINUOUSLY ELEVATED BASELINE CORTICOSTERONE BLOOD LEVELS IN THE ADULT AND AGED RATS. THE CHRONIC ELEVATION OF THE CORTICOSTERONE LEVELS WAS ACCOMPANIED BY A PROGRESSIVE DEFICIT OF THE GR EXPRESSION IN THE LIVER, INCREASED HEPATIC GLYCOGEN CONTENT, DYSREGULATED GLUCOSE-6-PHOSPHATASE ACTIVITY, AND EVENTUALLY HYPOGLYCEMIA. ELEVATED CORTICOSTERONE APPEARS TO RESULT FROM THE IMPAIRMENT OF THE MECHANISMS OF GLUCOCORTICOID NEGATIVE FEEDBACK SINCE A SUBSTANTIAL DECREASE IN BOTH THE TOTAL NUMBER OF GR AND THEIR NUCLEAR LOCALIZATION WAS OBSERVED ALREADY IN THE HIPPOCAMPUS OF NEWBORN RAT PUPS AND PERSISTED THROUGHOUT LIFE. CORRESPONDING STABLE HIPPOCAMPAL DOWNREGULATION OF GR-DEPENDENT GENES WAS OBSERVED AS WELL. SUPPRESSION OF THE MATERNAL GLUCOCORTICOID STRESS RESPONSE TO HYPOXIA BY METYRAPONE INJECTION TO PREGNANT RATS PRIOR TO EACH HYPOXIC CHALLENGE CONSIDERABLY REDUCED CORTICOSTERONE OVER-RESPONSE TO HYPOXIA AND PREVENTED REDUCED HIPPOCAMPAL GR. CONCLUSIONS: OUR FINDINGS DEMONSTRATE THAT IN PROGENY A DEFICIT OF HIPPOCAMPAL GR RESULTING FROM MATERNAL GLUCOCORTICOID RESPONSE TO HYPOXIA REMAINS STABLE THROUGHOUT LIFE AND IS ACCOMPANIED BY SEVERE DISTURBANCES OF BASELINE GLUCOCORTICOID LEVELS AND ITS PERIPHERAL RECEPTION. NEGATIVE CONSEQUENCES OF PSH CAN BE PREVENTED BY INJECTION WITH AN INHIBITOR OF CORTICOSTERONE SYNTHESIS (METYRAPONE) TO PREGNANT FEMALES UNDERGOING HYPOXIA. 2020 17 584 35 BEHAVIORAL NEUROADAPTATION TO ALCOHOL: FROM GLUCOCORTICOIDS TO HISTONE ACETYLATION. A PRIME MECHANISM THAT CONTRIBUTES TO THE DEVELOPMENT AND MAINTENANCE OF ALCOHOLISM IS THE DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS ACTIVITY AND THE RELEASE OF GLUCOCORTICOIDS (CORTISOL IN HUMANS AND PRIMATES, CORTICOSTERONE IN RODENTS) FROM THE ADRENAL GLANDS. IN THE BRAIN, SUSTAINED, LOCAL ELEVATION OF GLUCOCORTICOID CONCENTRATION EVEN LONG AFTER CESSATION OF CHRONIC ALCOHOL CONSUMPTION COMPROMISES FUNCTIONAL INTEGRITY OF A CIRCUIT, INCLUDING THE PREFRONTAL CORTEX (PFC), THE HIPPOCAMPUS (HPC), AND THE AMYGDALA (AMG). THESE STRUCTURES ARE IMPLICATED IN LEARNING AND MEMORY PROCESSES AS WELL AS IN ORCHESTRATING NEUROADAPTIVE RESPONSES TO STRESS AND ANXIETY RESPONSES. THUS, POTENTIATION OF ANXIETY-RELATED NEUROADAPTATION BY ALCOHOL IS CHARACTERIZED BY AN ABNORMALLY AMG HYPERACTIVITY COUPLED WITH A HYPOFUNCTION OF THE PFC AND THE HPC. THIS REVIEW DESCRIBES RESEARCH ON MOLECULAR AND EPIGENETIC MECHANISMS BY WHICH ALCOHOL CAUSES DISTINCT REGION-SPECIFIC ADAPTIVE CHANGES IN GENE EXPRESSION PATTERNS AND ULTIMATELY LEADS TO A VARIETY OF COGNITIVE AND BEHAVIORAL IMPAIRMENTS ON PREFRONTAL- AND HIPPOCAMPAL-BASED TASKS. ALCOHOL-INDUCED NEUROADAPTATIONS INVOLVE THE DYSREGULATION OF NUMEROUS SIGNALING CASCADES, LEADING TO LONG-TERM CHANGES IN TRANSCRIPTIONAL PROFILES OF GENES, THROUGH THE ACTIONS OF TRANSCRIPTION FACTORS SUCH AS [CAMP RESPONSE ELEMENT-BINDING PROTEIN (CREB)] AND CHROMATIN REMODELING DUE TO POSTTRANSLATIONAL MODIFICATIONS OF HISTONE PROTEINS. WE DESCRIBE THE ROLE OF PREFRONTAL-HPC-AMG CIRCUIT IN MEDIATING THE EFFECTS OF ACUTE AND CHRONIC ALCOHOL ON LEARNING AND MEMORY, AND REGION-SPECIFIC MOLECULAR AND EPIGENETIC MECHANISMS INVOLVED IN THIS PROCESS. THIS REVIEW FIRST DISCUSSES THE IMPORTANCE OF BRAIN REGION-SPECIFIC DYSREGULATION OF GLUCOCORTICOID CONCENTRATION IN THE DEVELOPMENT OF ALCOHOL DEPENDENCE AND DESCRIBES HOW PERSISTENTLY INCREASED GLUCOCORTICOID LEVELS IN PFC MAY BE INVOLVED IN MEDIATING WORKING MEMORY IMPAIRMENTS AND NEUROADAPTIVE CHANGES DURING WITHDRAWAL FROM CHRONIC ALCOHOL INTAKE. IT THEN HIGHLIGHTS THE ROLE OF CAMP-PKA-CREB SIGNALING CASCADE AND HISTONE ACETYLATION WITHIN THE PFC AND LIMBIC STRUCTURES IN ALCOHOL-INDUCED ANXIETY AND BEHAVIORAL IMPAIRMENTS, AND HOW AN UNDERSTANDING OF FUNCTIONAL ALTERATIONS OF THESE PATHWAYS MIGHT LEAD TO BETTER TREATMENTS FOR NEUROPSYCHIATRIC DISORDERS. 2016 18 6551 40 TRANSGENERATIONAL BLUNTING OF MORPHINE-INDUCED CORTICOSTERONE SECRETION IS ASSOCIATED WITH DYSREGULATED GENE EXPRESSION IN MALE OFFSPRING. A NUMBER OF PARENTAL EXPERIENCES, EVEN WHEN OCCURRING PRIOR TO CONCEPTION, HAVE BEEN SHOWN TO INDUCE TRANSGENERATIONAL EFFECTS BEYOND THE FIRST GENERATION. IN THE CASE OF EXPOSURE TO DRUGS OF ABUSE, STUDIES IN RODENTS SUGGEST THAT OFFSPRING DEMONSTRATE SIGNIFICANT DIFFERENCES IN HOW THEY RESPOND TO THE DRUG TO WHICH THEIR PARENT WAS EXPOSED. WE HAVE PREVIOUSLY OBSERVED SIGNIFICANT ALTERATIONS IN MORPHINE ANALGESIA, CONDITIONED PLACE PREFERENCE AND SELF-ADMINISTRATION IN THE OFFSPRING OF FEMALES EXPOSED TO MORPHINE DURING ADOLESCENT DEVELOPMENT. IN ADDITION TO EFFECTS ON PAIN PERCEPTION AND REWARD, MORPHINE ALSO MODULATES THE HYPOTHALAMIC PITUITARY ADRENAL (HPA) AXIS. THE PURPOSE OF THE CURRENT STUDY WAS TO DETERMINE WHETHER FEMALE ADOLESCENT MORPHINE EXPOSURE RESULTS IN TRANSGENERATIONAL EFFECTS ON REGULATION OF THE HPA AXIS BY MORPHINE IN FUTURE GENERATIONS. ADOLESCENT MORPHINE WAS ADMINISTERED TO FEMALE SPRAGUE DAWLEY RATS USING A 10 DAY, ESCALATING DOSE REGIMEN OF MORPHINE (5-25 MG/KG; FROM 30 TO 39 DAYS OF AGE). CONTROL ANIMALS RECEIVED SALINE. BOTH SALINE AND MORPHINE EXPOSED FEMALES (SAL-F0 AND MOR-F0, RESPECTIVELY) WERE MATED WITH DRUG NAIVE MALES BEGINNING AT LEAST 3 WEEKS AFTER THE FINAL INJECTION. PLASMA CORTICOSTERONE LEVELS WERE MEASURED IN MALE AND FEMALE OFFSPRING (F1) DURING ADULTHOOD FOLLOWING 0, 0.1, OR 10 MG/KG MORPHINE. IN ADDITION, EXPRESSION OF CORTICOTROPIN RELEASING HORMONE (CRH) AND MU OPIOID RECEPTOR (OPRM1) IN THE PARAVENTRICULAR NUCLEUS (PVN) WERE MEASURED USING QUANTITATIVE PCR. MOR-F1 MALES, BUT NOT FEMALES, HAD BLUNTED MORPHINE-INDUCED CORTICOSTERONE SECRETION. THIS EFFECT WAS SPECIFIC TO OFFSPRING FROM FEMALES EXPOSED TO MORPHINE DURING ADOLESCENCE AS THOSE EXPOSED DURING ADULTHOOD PRODUCED OFFSPRING IN WHICH THE EFFECT WAS ABSENT. IN ADDITION, MOR-F1 MALES HAD SIGNIFICANTLY LOWER LEVELS OF PVN CRH FOLLOWING SALINE. THESE EFFECTS WERE NOT DRIVEN BY PVN OPRM1 IN THE F1 MALES AS THERE WERE NO DIFFERENCES BASED ON MATERNAL ADOLESCENT EXPOSURE. TO DETERMINE THE PERSISTENCE OF THE BLUNTED MORPHINE-INDUCED CORTICOSTERONE EFFECT, SAL-F2 AND MOR-F2 MALES WERE EXAMINED. BLUNTED MORPHINE-INDUCED CORTICOSTERONE SECRETION EXTENDED INTO THE MOR-F2 GENERATION, AS WELL AS EFFECTS ON CRH. IN ADDITION, THERE WAS ADDITIONAL DYSREGULATION OFOPRM1 EXPRESSION IN THE PVN IN MOR-F2 COMPARED WITH SAL-F2 MALES. THESE FINDINGS SUGGEST THAT SEX-SPECIFIC ALTERATIONS IN OPIOID-MEDIATED REGULATION OF THE HPA AXIS ARE TRANSGENERATIONALLY TRANSMITTED FOR AT LEAST TWO GENERATIONS FOLLOWING FEMALE ADOLESCENT MORPHINE EXPOSURE. THESE EFFECTS MAY PLAY A ROLE IN THE PREVIOUSLY OBSERVED CHANGES IN MORPHINE ANALGESIA AND REWARD-RELATED BEHAVIORS OBSERVED IN THIS PHENOTYPE. IN ADDITION, ALTERATIONS IN HPA FUNCTIONING SUCH AS THESE MAY PLAY A BROAD ROLE IN TRANSGENERATIONAL EPIGENETIC TRANSMISSION. 2018 19 5467 28 RESILIENT PHENOTYPE IN CHRONIC MILD STRESS PARADIGM IS ASSOCIATED WITH ALTERED EXPRESSION LEVELS OF MIR-18A-5P AND SEROTONIN 5-HT(1A) RECEPTOR IN DORSAL PART OF THE HIPPOCAMPUS. DISTURBED SEROTONERGIC SIGNALING IN THE HIPPOCAMPUS OBSERVED IN MANY INDIVIDUALS VULNERABLE TO STRESS HAS BEEN SUGGESTED AS ONE OF THE PRIMARY FACTORS CONTRIBUTING TO THE DEVELOPMENT OF DEPRESSION. HOWEVER, LITTLE IS KNOWN ABOUT THE PHYSIOLOGY OF THE BRAIN IN THE RESILIENT PHENOTYPE. RESILIENT SUBJECTS MAINTAIN A POSITIVE MOOD AND PSYCHOLOGICAL BALANCE DESPITE BEING UNDER THE STRESS INFLUENCE. IN OUR STUDY, WE GENERATED STRESS-VULNERABLE AND RESILIENT RATS BY USING A CHRONIC MILD STRESS (CMS) PARADIGM. USING DIFFERENT MOLECULAR APPROACHES, WE REVEALED THAT RESILIENT ANIMALS EXHIBITED A SIGNIFICANTLY DECREASED EXPRESSION LEVEL OF MIR-18A-5P AND, IN THE SAME TIME, AN ELEVATED LEVEL OF 5-HT1AR IN DORSAL, BUT NOT VENTRAL, PART OF THE HIPPOCAMPUS. DESCRIBED BIOCHEMICAL CHANGES WERE NOT OBSERVED IN ANIMALS BEHAVIORALLY VULNERABLE TO STRESS. FURTHER, IN VITRO ANALYSIS SHOWED THAT MIR-18A-5P MAY BE A NEGATIVE EPIGENETIC REGULATOR OF 5-HT1AR SINCE THE TREATMENT OF ADULT HIPPOCAMPAL NEURONS WITH MIR-18A-5P MIMIC SIGNIFICANTLY LOWERED THE EXPRESSION LEVEL OF MRNA ENCODING 5-HT1AR. MOREOVER, BIOINFORMATIC ANALYSIS OF POTENTIAL TARGET GENES EXPRESSED IN THE HIPPOCAMPUS AND BEING REGULATED BY MIR-18A-5P SHOWED THAT THIS MICRORNA MAY REGULATE BIOLOGICAL PROCESSES, SUCH AS AXONOGENESIS, WHICH ARE IMPORTANT IN THE FUNCTIONING OF THE HIPPOCAMPUS IN BOTH RATS AND HUMANS. ALL THESE MOLECULAR FEATURES MAY CONTRIBUTE TO SEROTONERGIC HOMEOSTATIC BALANCE AT THE LEVEL OF SEROTONIN TURNOVER OBSERVED IN HIPPOCAMPI OF RESILIENT BUT NOT STRESS-VULNERABLE RATS. DELINEATION OF FURTHER MOLECULAR AND BIOCHEMICAL MARKERS UNDERLYING RESILIENCE TO STRESS MAY CONTRIBUTE TO THE DEVELOPMENT OF NEW ANTIDEPRESSANT STRATEGIES WHICH WILL RESTORE RESILIENT PHENOTYPE IN DEPRESSED PATIENTS. 2019 20 5219 33 PREVIOUS HISTORY OF CHRONIC STRESS CHANGES THE TRANSCRIPTIONAL RESPONSE TO GLUCOCORTICOID CHALLENGE IN THE DENTATE GYRUS REGION OF THE MALE RAT HIPPOCAMPUS. CHRONIC STRESS IS A RISK FACTOR FOR SEVERAL NEUROPSYCHIATRIC DISEASES, SUCH AS DEPRESSION AND PSYCHOSIS. IN RESPONSE TO STRESS GLUCOCORTICOIDS (GCS) ARE SECRETED THAT BIND TO MINERALOCORTICOID AND GLUCOCORTICOID RECEPTORS, LIGAND-ACTIVATED TRANSCRIPTION FACTORS THAT REGULATE THE TRANSCRIPTION OF GENE NETWORKS IN THE BRAIN NECESSARY FOR COPING WITH STRESS, RECOVERY, AND ADAPTATION. CHRONIC STRESS PARTICULARLY AFFECTS THE DENTATE GYRUS (DG) SUBREGION OF THE HIPPOCAMPUS, CAUSING SEVERAL FUNCTIONAL AND MORPHOLOGICAL CHANGES WITH CONSEQUENCES FOR LEARNING AND MEMORY, WHICH ARE LIKELY ADAPTIVE BUT AT THE SAME TIME MAKE DG NEURONS MORE VULNERABLE TO SUBSEQUENT CHALLENGES. THE AIM OF THIS STUDY WAS TO INVESTIGATE THE TRANSCRIPTIONAL RESPONSE OF DG NEURONS TO A GC CHALLENGE IN MALE RATS PREVIOUSLY EXPOSED TO CHRONIC RESTRAINT STRESS (CRS). AN INTRIGUING FINDING OF THE CURRENT STUDY WAS THAT HAVING A HISTORY OF CRS HAD PROFOUND CONSEQUENCES FOR THE SUBSEQUENT RESPONSE TO ACUTE GC CHALLENGE, DIFFERENTIALLY AFFECTING THE EXPRESSION OF SEVERAL HUNDREDS OF GENES IN THE DG COMPARED WITH CHALLENGED NONSTRESSED CONTROL ANIMALS. THIS ENDURING EFFECT OF PREVIOUS STRESS EXPOSURE SUGGESTS THAT EPIGENETIC PROCESSES MAY BE INVOLVED. IN LINE WITH THIS, CRS INDEED AFFECTED THE EXPRESSION OF SEVERAL GENES INVOLVED IN CHROMATIN STRUCTURE AND EPIGENETIC PROCESSES, INCLUDING ASF1, ASH1L, HIST1H3F, AND TP63. THE DATA PRESENTED HERE INDICATE THAT CRS ALTERS THE TRANSCRIPTIONAL RESPONSE TO A SUBSEQUENT GC INJECTION. WE PROPOSE THAT THIS ALTERED TRANSCRIPTIONAL POTENTIAL FORMS PART OF THE MOLECULAR MECHANISM UNDERLYING THE ENHANCED VULNERABILITY FOR STRESS-RELATED DISORDERS LIKE DEPRESSION CAUSED BY CHRONIC STRESS. 2013