1 3463 137 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 2 5815 39 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 3 6267 38 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 4 3405 38 HOW STRESS GETS UNDER THE SKIN: EARLY LIFE ADVERSITY AND GLUCOCORTICOID RECEPTOR EPIGENETIC REGULATION. EARLY LIFE ADVERSITY IS ASSOCIATED WITH BOTH PERSISTENT DISRUPTIONS IN THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS AND PSYCHIATRIC SYMPTOMS. GLUCOCORTICOID RECEPTORS (GRS), WHICH ARE ENCODED BY THE NR3C1 GENE, BIND TO CORTISOL AND OTHER GLUCOCORTICOIDS TO CREATE A NEGATIVE FEEDBACK LOOP WITHIN THE HPA AXIS TO REGULATE THE BODY'S NEUROENDOCRINE RESPONSE TO STRESS. EXCESS METHYLATION OF A PROMOTER SEQUENCE WITHIN NR3C1 THAT ATTENUATES GR EXPRESSION, HOWEVER, HAS BEEN ASSOCIATED WITH BOTH EARLY LIFE ADVERSITY AND PSYCHOPATHOLOGY. AS CRITICAL REGULATORS WITHIN THE HPA AXIS, GRS AND THEIR EPIGENETIC REGULATION MAY MEDIATE THE LINK BETWEEN EARLY LIFE ADVERSITY AND THE ONSET OF PSYCHOPATHOLOGY. THE PRESENT REVIEW DISCUSSES THIS WORK AS ONE MECHANISM BY WHICH STRESS MAY GET UNDER THE SKIN TO DISRUPT HPA FUNCTIONING AT AN EPIGENETIC LEVEL AND CREATE LONG-LASTING VULNERABILITIES IN THE STRESS REGULATORY SYSTEM THAT SUBSEQUENTLY PREDISPOSE INDIVIDUALS TO PSYCHOPATHOLOGY. SPANNING PRENATAL INFLUENCES TO CRITICAL PERIODS OF EARLY LIFE AND ADOLESCENCE, WE DETAIL THE IMPACT THAT EARLY ADVERSITY HAS ON GR EXPRESSION, PHYSIOLOGICAL RESPONSES TO STRESS, AND THEIR IMPLICATIONS FOR LONG-TERM STRESS MANAGEMENT. WE NEXT PROPOSE A DUAL TRANSMISSION HYPOTHESIS REGARDING BOTH GENOMIC AND NON-GENOMIC MECHANISMS BY WHICH CHRONIC AND ACUTE STRESS PROPAGATE THROUGH NUMEROUS GENERATIONS. LASTLY, WE OUTLINE SEVERAL DIRECTIONS FOR FUTURE RESEARCH, INCLUDING POTENTIAL REVERSIBILITY OF METHYLATION PATTERNS AND ITS FUNCTIONAL IMPLICATIONS, VARIATION IN BEHAVIOR DETERMINED SOLELY BY NR3C1, AND CONSENSUS ON WHICH SPECIFIC PROMOTER REGIONS SHOULD BE STUDIED. 2018 5 3092 39 GENOMIC AND EPIGENOMIC MECHANISMS OF GLUCOCORTICOIDS IN THE BRAIN. FOLLOWING THE DISCOVERY OF GLUCOCORTICOID RECEPTORS IN THE HIPPOCAMPUS AND OTHER BRAIN REGIONS, RESEARCH HAS FOCUSED ON UNDERSTANDING THE EFFECTS OF GLUCOCORTICOIDS IN THE BRAIN AND THEIR ROLE IN REGULATING EMOTION AND COGNITION. GLUCOCORTICOIDS ARE ESSENTIAL FOR ADAPTATION TO STRESSORS (ALLOSTASIS) AND IN MALADAPTATION RESULTING FROM ALLOSTATIC LOAD AND OVERLOAD. ALLOSTATIC OVERLOAD, WHICH CAN OCCUR DURING CHRONIC STRESS, CAN RESHAPE THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS THROUGH EPIGENETIC MODIFICATION OF GENES IN THE HIPPOCAMPUS, HYPOTHALAMUS AND OTHER STRESS-RESPONSIVE BRAIN REGIONS. GLUCOCORTICOIDS EXERT THEIR EFFECTS ON THE BRAIN THROUGH GENOMIC MECHANISMS THAT INVOLVE BOTH GLUCOCORTICOID RECEPTORS AND MINERALOCORTICOID RECEPTORS DIRECTLY BINDING TO DNA, AS WELL AS BY NON-GENOMIC MECHANISMS. FURTHERMORE, GLUCOCORTICOIDS SYNERGIZE BOTH GENOMICALLY AND NON-GENOMICALLY WITH NEUROTRANSMITTERS, NEUROTROPHIC FACTORS, SEX HORMONES AND OTHER STRESS MEDIATORS TO SHAPE AN ORGANISM'S PRESENT AND FUTURE RESPONSES TO A STRESSFUL ENVIRONMENT. HERE, WE DISCUSS THE MECHANISMS OF GLUCOCORTICOID ACTION IN THE BRAIN AND REVIEW HOW GLUCOCORTICOIDS INTERACT WITH STRESS MEDIATORS IN THE CONTEXT OF ALLOSTASIS, ALLOSTATIC LOAD AND STRESS-INDUCED NEUROPLASTICITY. 2017 6 5209 43 PRENATAL XENOBIOTIC EXPOSURE AND INTRAUTERINE HYPOTHALAMUS-PITUITARY-ADRENAL AXIS PROGRAMMING ALTERATION. THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS IS ONE OF THE MOST IMPORTANT NEUROENDOCRINE AXES AND PLAYS AN IMPORTANT ROLE IN STRESS DEFENSE RESPONSES BEFORE AND AFTER BIRTH. PRENATAL EXPOSURE TO XENOBIOTICS, INCLUDING ENVIRONMENTAL TOXINS (SUCH AS SMOKE, SULFUR DIOXIDE AND CARBON MONOXIDE), DRUGS (SUCH AS SYNTHETIC GLUCOCORTICOIDS), AND FOODS AND BEVERAGE CATEGORIES (SUCH AS ETHANOL AND CAFFEINE), AFFECTS FETAL DEVELOPMENT INDIRECTLY BY CHANGING THE MATERNAL STATUS OR DAMAGING THE PLACENTA. CERTAIN XENOBIOTICS (SUCH AS CAFFEINE, ETHANOL AND DEXAMETHASONE) MAY ALSO AFFECT THE FETUS DIRECTLY BY CROSSING THE PLACENTA INTO THE FETUS DUE TO THEIR LIPOPHILIC PROPERTIES AND LOWER MOLECULAR WEIGHTS. ALL OF THESE FACTORS PROBABLY RESULT IN INTRAUTERINE PROGRAMMING ALTERATION OF THE HPA AXIS, WHICH SHOWED A LOW BASAL ACTIVITY BUT HYPERSENSITIVITY TO CHRONIC STRESS. THESE ALTERATIONS WILL, THEREFORE, INCREASE THE SUSCEPTIBILITY TO ADULT NEUROPSYCHIATRIC (SUCH AS DEPRESSION AND SCHIZOPHRENIA) AND METABOLIC DISEASES (SUCH AS HYPERTENSION, DIABETES AND NON-ALCOHOLIC FATTY LIVER DISEASE). THE "OVER-EXPOSURE OF FETUSES TO MATERNAL GLUCOCORTICOIDS" MAY BE THE MAIN INITIATION FACTOR BY WHICH THE FETAL HPA AXIS PROGRAMMING IS ALTERED. MEANTIME, XENOBIOTICS CAN DIRECTLY INDUCE ABNORMAL EPIGENETIC MODIFICATIONS AND EXPRESSION ON THE IMPORTANT FETAL GENES (SUCH AS HIPPOCAMPAL GLUCOCORTICOID RECEPTOR, ADRENAL STEROIDOGENIC ACUTE REGULATORY PROTEIN, ET AL) OR DAMAGE BY IN SITU OXIDATIVE METABOLISM OF FETAL ADRENALS, WHICH MAY ALSO BE CONTRIBUTED TO THE PROGRAMMING ALTERATION OF FETAL HPA AXIS. 2014 7 4222 32 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 8 4948 41 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 9 6729 41 VULNERABILITY TO STROKE: IMPLICATIONS OF PERINATAL PROGRAMMING OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS. CHRONIC STRESS IS CAPABLE OF EXACERBATING EACH MAJOR, MODIFIABLE, ENDOGENOUS RISK FACTOR FOR CEREBROVASCULAR AND CARDIOVASCULAR DISEASE. INDEED, EXPOSURE TO STRESS CAN INCREASE BOTH THE INCIDENCE AND SEVERITY OF STROKE, PRESUMABLY THROUGH ACTIVATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS. NOW THAT CHARACTERIZATION OF THE MECHANISMS UNDERLYING EPIGENETIC PROGRAMMING OF THE HPA AXIS IS WELL UNDERWAY, THERE HAS BEEN RENEWED INTEREST IN EXAMINING THE ROLE OF EARLY ENVIRONMENT ON THE EVOLUTION OF HEALTH CONDITIONS ACROSS THE ENTIRE LIFESPAN. INDEED, NEONATAL MANIPULATIONS IN RODENTS THAT REDUCE STRESS RESPONSIVITY, AND SUBSEQUENT LIFE-TIME EXPOSURE TO GLUCOCORTICOIDS, ARE ASSOCIATED WITH A REDUCTION IN THE DEVELOPMENT OF NEUROENDOCRINE, NEUROANATOMICAL, AND COGNITIVE DYSFUNCTIONS THAT TYPICALLY PROGRESS WITH AGE. ALTHOUGH IMPROVED DAY TO DAY REGULATION OF THE HPA AXIS ALSO MAY BE ACCOMPANIED BY A DECREASE IN STROKE RISK, EVIDENCE FROM RODENT STUDIES SUGGEST THAT AN ASSOCIATED COST COULD BE INCREASED SUSCEPTIBILITY TO INFLAMMATION AND NEURONAL DEATH IN THE EVENT THAT A STROKE DOES OCCUR AND THE INDIVIDUAL IS EXPOSED TO PERSISTENTLY ELEVATED CORTICOSTEROIDS. GIVEN ITS IMPORTANCE IN REGULATION OF HEALTH AND DISEASE STATES, ANY LONG-TERM MODULATION OF THE HPA AXIS IS LIKELY TO BE ASSOCIATED WITH BOTH BENEFITS AND POTENTIAL RISKS. THE GOALS OF THIS REVIEW ARTICLE ARE TO EXAMINE (1) THE CLINICAL AND EXPERIMENTAL DATA SUGGESTING THAT NEONATAL EXPERIENCES CAN SHAPE HPA AXIS REGULATION, (2) THE INFLUENCE OF STRESS AND THE HPA AXIS ON STROKE INCIDENCE AND SEVERITY, AND (3) THE POTENTIAL FOR NEONATAL PROGRAMMING OF THE HPA AXIS TO IMPACT ADULT CEREBROVASCULAR HEALTH. 2009 10 5200 32 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 4343 32 MINIREVIEW: STRESS-RELATED PSYCHIATRIC DISORDERS WITH LOW CORTISOL LEVELS: A METABOLIC HYPOTHESIS. SEVERAL STRESS-ASSOCIATED NEUROPSYCHIATRIC DISORDERS, NOTABLY POSTTRAUMATIC STRESS DISORDER AND CHRONIC PAIN AND FATIGUE SYNDROMES, PARADOXICALLY EXHIBIT SOMEWHAT LOW PLASMA LEVELS OF THE STRESS HORMONE CORTISOL. THE EFFECTS APPEAR GREATEST IN THOSE INITIALLY TRAUMATIZED IN EARLY LIFE, IMPLYING A DEGREE OF DEVELOPMENTAL PROGRAMMING, PERHAPS OF BOTH LOWER CORTISOL AND VULNERABILITY TO PSYCHOPATHOLOGY. IN THESE CONDITIONS, LOWERED CORTISOL IS NOT DUE TO ANY ADRENAL OR PITUITARY INSUFFICIENCY. INSTEAD, TWO PROCESSES APPEAR INVOLVED. FIRST, THERE IS INCREASED TARGET CELL SENSITIVITY TO GLUCOCORTICOID ACTION, NOTABLY NEGATIVE FEEDBACK UPON THE HYPOTHALAMIC-PITUITARY-ADRENAL (STRESS) AXIS. ALTERED DENSITY OF THE GLUCOCORTICOID RECEPTOR IS INFERRED, SQUARING WITH MUCH PRECLINICAL DATA SHOWING EARLY LIFE CHALLENGES CAN PERMANENTLY PROGRAM GLUCOCORTICOID RECEPTORS IN A TISSUE-SPECIFIC MANNER. THESE EFFECTS INVOLVE EPIGENETIC MECHANISMS. SECOND, EARLY LIFE TRAUMA/STARVATION INDUCES LONG-LASTING LOWERING OF GLUCOCORTICOID CATABOLISM, SPECIFICALLY BY 5ALPHA-REDUCTASE TYPE 1 (PREDOMINANTLY A LIVER ENZYME) AND 11BETA-HYDROXYSTEROID DEHYDROGENASE TYPE 2 (IN KIDNEY), AN EFFECT ALSO SEEN IN MODEL SYSTEMS. THESE CHANGES REFLECT A PLAUSIBLE EARLY-LIFE ADAPTATION TO INCREASE THE PERSISTENCE OF ACTIVE CORTISOL IN LIVER (TO MAXIMIZE FUEL OUTPUT) AND KIDNEY (TO INCREASE SALT RETENTION) WITHOUT ELEVATION OF CIRCULATING LEVELS, THUS AVOIDING THEIR DELETERIOUS EFFECTS ON BRAIN AND MUSCLE. MODESTLY LOWERED CIRCULATING CORTISOL AND INCREASED VULNERABILITY TO STRESS-ASSOCIATED DISORDERS MAY BE THE OUTCOME. THIS NOTION IMPLIES A VULNERABLE EARLY-LIFE PHENOTYPE MAY BE DISCERNABLE AND INDICATES POTENTIAL THERAPY BY MODEST GLUCOCORTICOID REPLACEMENT. INDEED, EARLY CLINICAL TRIALS WITH CORTISOL HAVE SHOWN A MODICUM OF PROMISE. 2011 12 235 31 ADDING FUEL TO THE FIRE: THE IMPACT OF STRESS ON THE AGEING BRAIN. BOTH AGEING AND CHRONIC STRESS ARE ASSOCIATED WITH ALTERED BRAIN PLASTICITY, DYSREGULATION OF THE IMMUNE SYSTEM, AND AN INCREASED RISK OF DEVELOPING BRAIN DISORDERS; ALL OF WHICH HAVE CONSEQUENCES FOR COGNITIVE AND EMOTIONAL PROCESSING. HERE WE EXAMINE THE SIMILARITIES BETWEEN BEHAVIOURAL CHANGES DURING AGEING AND STRESS ALTERED BEHAVIOURS (ANXIETY, DEPRESSIVE-LIKE BEHAVIOUR, COGNITION, AND SOCIABILITY) IN RODENTS AND HUMANS. THE MOLECULAR MECHANISMS HYPOTHESISED TO MEDIATE AGE-RELATED CHANGES IN BRAIN FUNCTION INCLUDING DYSFUNCTION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS, DYSREGULATION OF NEUROTRANSMISSION AND NEUROTROPHIC FACTOR SIGNALLING, INCREASED INFLAMMATORY STATE, GENETIC AND EPIGENETIC CHANGES, OXIDATIVE STRESS, METABOLIC CHANGES, AND CHANGES IN THE MICROBIOTA-GUT-BRAIN AXIS ARE DISCUSSED. FINALLY, WE EXPLORE HOW THE ALREADY STRESSED AGED BRAIN PSYCHOLOGICALLY AND PHYSIOLOGICALLY RESPONDS TO EXTERNAL STRESSORS. 2015 13 2144 30 EPIGENETIC LANDSCAPE OF STRESS SURFEIT DISORDERS: KEY ROLE FOR DNA METHYLATION DYNAMICS. CHRONIC EXPOSURE TO STRESS THROUGHOUT LIFESPAN ALTERS BRAIN STRUCTURE AND FUNCTION, INDUCING A MALADAPTIVE RESPONSE TO ENVIRONMENTAL STIMULI, THAT CAN CONTRIBUTE TO THE DEVELOPMENT OF A PATHOLOGICAL PHENOTYPE. STUDIES HAVE SHOWN THAT HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS DYSFUNCTION IS ASSOCIATED WITH VARIOUS NEUROPSYCHIATRIC DISORDERS, INCLUDING MAJOR DEPRESSIVE, ALCOHOL USE AND POST-TRAUMATIC STRESS DISORDERS. DOWNSTREAM ACTORS OF THE HPA AXIS, GLUCOCORTICOIDS ARE CRITICAL MEDIATORS OF THE STRESS RESPONSE AND EXERT THEIR FUNCTION THROUGH SPECIFIC RECEPTORS, I.E., THE GLUCOCORTICOID RECEPTOR (GR), HIGHLY EXPRESSED IN STRESS/REWARD-INTEGRATIVE PATHWAYS. GRS ARE LIGAND-ACTIVATED TRANSCRIPTION FACTORS THAT RECRUIT EPIGENETIC ACTORS TO REGULATE GENE EXPRESSION VIA DNA METHYLATION, ALTERING CHROMATIN STRUCTURE AND THUS SHAPING THE RESPONSE TO STRESS. THE DYNAMIC INTERPLAY BETWEEN STRESS RESPONSE AND EPIGENETIC MODIFIERS SUGGEST DNA METHYLATION PLAYS A KEY ROLE IN THE DEVELOPMENT OF STRESS SURFEIT DISORDERS. 2021 14 4118 30 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 15 2269 43 EPIGENETIC PROGRAMMING OF THE NEUROENDOCRINE STRESS RESPONSE BY ADULT LIFE STRESS. THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS IS CRITICALLY INVOLVED IN THE NEUROENDOCRINE REGULATION OF STRESS ADAPTATION, AND THE RESTORATION OF HOMEOSTASIS FOLLOWING STRESS EXPOSURE. DYSREGULATION OF THIS AXIS IS ASSOCIATED WITH STRESS-RELATED PATHOLOGIES LIKE MAJOR DEPRESSIVE DISORDER, POST-TRAUMATIC STRESS DISORDER, PANIC DISORDER AND CHRONIC ANXIETY. IT HAS LONG BEEN UNDERSTOOD THAT STRESS DURING EARLY LIFE CAN HAVE A SIGNIFICANT LASTING INFLUENCE ON THE DEVELOPMENT OF THE NEUROENDOCRINE SYSTEM AND ITS NEURAL REGULATORS, PARTIALLY BY MODIFYING EPIGENETIC REGULATION OF GENE EXPRESSION, WITH IMPLICATIONS FOR HEALTH AND WELL-BEING IN LATER LIFE. EVIDENCE IS ACCUMULATING THAT EPIGENETIC PLASTICITY ALSO EXTENDS TO ADULTHOOD, PROPOSING IT AS A MECHANISM BY WHICH PSYCHOLOGICAL TRAUMA LATER IN LIFE CAN LONG-LASTINGLY AFFECT HPA AXIS FUNCTION, BRAIN PLASTICITY, NEURONAL FUNCTION AND BEHAVIOURAL ADAPTATION TO NEUROPSYCHOLOGICAL STRESS. FURTHER CORROBORATING THIS CLAIM IS THE PHENOMENON THAT THESE EPIGENETIC CHANGES CORRELATE WITH THE BEHAVIOURAL CONSEQUENCES OF TRAUMA EXPOSURE. THEREBY, EPIGENETIC MODIFICATIONS PROVIDE A PUTATIVE MOLECULAR MECHANISM BY WHICH THE BEHAVIOURAL PHENOTYPE AND TRANSCRIPTIONAL/TRANSLATIONAL POTENTIAL OF GENES INVOLVED IN HPA AXIS REGULATION CAN CHANGE DRASTICALLY IN RESPONSE TO ENVIRONMENTAL CHALLENGES, AND APPEAR AN IMPORTANT TARGET FOR TREATMENT OF STRESS-RELATED DISORDERS. HOWEVER, IMPROVED INSIGHT IS REQUIRED TO INCREASE THEIR THERAPEUTIC (DRUG) POTENTIAL. HERE, WE PROVIDE AN OVERVIEW OF THE GROWING BODY OF LITERATURE DESCRIBING THE EPIGENETIC MODULATION OF THE (PRIMARILY NEUROENDOCRINE) STRESS RESPONSE AS A CONSEQUENCE OF ADULT LIFE STRESS AND INTERPRET THE IMPLICATIONS FOR, AND THE CHALLENGES INVOLVED IN APPLYING THIS KNOWLEDGE TO, THE IDENTIFICATION AND TREATMENT OF STRESS-RELATED PSYCHIATRIC DISORDERS. 2017 16 3151 41 GLUCOCORTICOIDS, EPIGENETIC CONTROL AND STRESS RESILIENCE. GLUCOCORTICOID HORMONES PLAY A PIVOTAL ROLE IN THE RESPONSE TO STRESSFUL CHALLENGES. THE SURGE IN GLUCOCORTICOID HORMONE SECRETION AFTER STRESS NEEDS TO BE TIGHTLY CONTROLLED WITH CHARACTERISTICS LIKE PEAK HEIGHT, CURVATURE AND DURATION DEPENDING ON THE NATURE AND SEVERITY OF THE CHALLENGE. THIS IS IMPORTANT AS CHRONIC HYPER- OR HYPO-RESPONSES ARE DETRIMENTAL TO HEALTH DUE TO INCREASING THE RISK FOR DEVELOPING A STRESS-RELATED MENTAL DISORDER. PROPER GLUCOCORTICOID RESPONSES TO STRESS ARE CRITICAL FOR ADAPTATION. THEREFORE, THE TIGHT CONTROL OF BASELINE AND STRESS-EVOKED GLUCOCORTICOID SECRETION ARE IMPORTANT CONSTITUENTS OF AN ORGANISM'S RESILIENCE. HERE, WE ADDRESS A NUMBER OF MECHANISMS THAT ILLUSTRATE THE MULTITUDE AND COMPLEXITY OF MEASURES SAFEGUARDING THE CONTROL OF GLUCOCORTICOID FUNCTION. THESE MECHANISMS INCLUDE THE CONTROL OF MINERALOCORTICOID (MR) AND GLUCOCORTICOID RECEPTOR (GR) OCCUPANCY AND CONCENTRATION, THE DYNAMIC CONTROL OF FREE GLUCOCORTICOID HORMONE AVAILABILITY BY CORTICOSTEROID-BINDING GLOBULIN (CBG), AND THE CONTROL EXERTED BY GLUCOCORTICOIDS AT THE SIGNALING, EPIGENETIC AND GENOMIC LEVEL ON GENE TRANSCRIPTIONAL RESPONSES TO STRESS. WE REVIEW THE BENEFICIAL EFFECTS OF REGULAR EXERCISE ON HPA AXIS AND SLEEP PHYSIOLOGY, AND COGNITIVE AND ANXIETY-RELATED BEHAVIOR. FURTHERMORE, WE DESCRIBE THAT, POSSIBLY THROUGH CHANGES IN THE GABAERGIC SYSTEM, EXERCISE REDUCES THE IMPACT OF STRESS ON A SIGNALING PATHWAY SPECIFICALLY IN THE DENTATE GYRUS THAT IS STRONGLY IMPLICATED IN THE BEHAVIORAL RESPONSE TO THAT STRESSOR. THESE OBSERVATIONS UNDERLINE THE IMPACT OF LIFE STYLE ON STRESS RESILIENCE. FINALLY, WE ADDRESS HOW SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) AFFECTING GLUCOCORTICOID ACTION CAN COMPROMISE STRESS RESILIENCE, WHICH BECOMES MOST APPARENT UNDER CONDITIONS OF CHILDHOOD ABUSE. 2015 17 5160 39 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 18 4622 30 NEUROBIOLOGICAL DEVELOPMENT IN THE CONTEXT OF CHILDHOOD TRAUMA. NEUROBIOLOGICAL SYSTEMS MAY BE PARTICULARLY SUSCEPTIBLE TO DELETERIOUS IMPACT OF CHILDHOOD TRAUMA, AND THE IMPACT OF CHILDHOOD TRAUMA ON DEVELOPMENT AND SUBSEQUENT FUNCTIONAL OUTCOMES ACROSS THE LIFESPAN HAS BEEN WELL-DOCUMENTED. THE CURRENT REVIEW ADDRESSES THE NEUROBIOLOGICAL IMPACT OF EXPOSURE TO INTERPERSONAL TRAUMA IN CHILDHOOD IN THE CONTEXT OF EXECUTIVE FUNCTION, EMOTION REGULATION, AND DISSOCIATION/INTEROCEPTIVE AWARENESS. SUBSEQUENT RISK FOR PTSD AND DEPRESSION IS ALSO DISCUSSED. THE PATHWAY OF RISK FROM CHILDHOOD TRAUMA TO THESE COGNITIVE, EMOTIONAL, AND PSYCHIATRIC OUTCOMES IS ADDRESSED IN TERMS OF POTENTIAL STRUCTURAL AND FUNCTIONAL ALTERATIONS WITHIN THE HIPPOCAMPUS, PREFRONTAL CORTEX, AND AMYGDALA RESULTING FROM CHRONIC OR REPEATED ACTIVATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS AND ITS INTERACTION WITH AND INFLUENCE ON GENETIC AND EPIGENETIC PROCESSES DURING SENSITIVE PERIODS OF DEVELOPMENT. IMPLICATIONS FOR PRACTICE ARE DISCUSSED. 2017 19 6478 29 TOPICAL REVIEW: THE EMERGING FIELD OF EPIGENETICS: INFORMING MODELS OF PEDIATRIC TRAUMA AND PHYSICAL HEALTH. OBJECTIVE: TRAUMA EXPERIENCED DURING CHILDHOOD AND ADOLESCENCE HAS BEEN LINKED TO A NUMBER OF CHRONIC MEDICAL CONCERNS. WE HIGHLIGHT MAJOR FINDINGS FROM THE PEDIATRIC TRAUMA LITERATURE TO PROVIDE A MODEL FOR UNDERSTANDING THIS ASSOCIATION. METHODS: STUDIES EXAMINING THE EFFECTS OF TRAUMA WERE SYSTEMATICALLY REVIEWED AND SYNTHESIZED INTO A MODEL PROPOSING A CENTRAL ROLE FOR EPIGENETICS IN THE WAYS THAT CHILDHOOD EXPERIENCES CAN AFFECT HEALTH. RESULTS: EARLY HYPOTHALAMIC PITUITARY ADRENAL (HPA) AXIS RESPONSE MAY IMPACT INITIAL TRAUMA EXPERIENCE, WITH DOWNSTREAM EFFECTS ON POSTTRAUMA ADJUSTMENT REFLECTED IN POSTTRAUMA NEUROBIOLOGY, PSYCHOLOGICAL HEALTH, AND PHYSICAL HEALTH. CONCLUSIONS: PROSPECTIVE RESEARCH WITH CHILDREN AND ADOLESCENTS EXPOSED TO TRAUMA IS NEEDED TO BETTER CHARACTERIZE THE GENETIC AND EPIGENETIC INFLUENCES ON THE COURSE OF HPA AND IMMUNE PROCESSES AS RELATED TO POSTTRAUMA PSYCHOLOGICAL AND PHYSICAL HEALTH OUTCOMES. 2016 20 6278 38 THE PATHWAYS BETWEEN CORTISOL-RELATED REGULATION GENES AND PTSD PSYCHOTHERAPY. POST-TRAUMATIC STRESS DISORDER (PTSD) ONLY DEVELOPS AFTER EXPOSURE TO A TRAUMATIC EVENT IN SOME INDIVIDUALS. PTSD CAN BE CHRONIC AND DEBILITATING, AND IS ASSOCIATED WITH CO-MORBIDITIES SUCH AS DEPRESSION, SUBSTANCE USE, AND CARDIOMETABOLIC DISORDERS. ONE OF THE MOST IMPORTANT PATHOPHYSIOLOGICAL MECHANISMS UNDERLYING THE DEVELOPMENT OF PTSD AND ITS SUBSEQUENT MAINTENANCE IS A DYSFUNCTIONAL HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS. THE CORTICOTROPHIN-RELEASING HORMONE, CORTISOL, GLUCOCORTICOID RECEPTOR (GR), AND THEIR RESPECTIVE GENES ARE SOME OF THE MEDIATORS OF PTSD'S PATHOPHYSIOLOGY. SEVERAL TREATMENTS ARE AVAILABLE, INCLUDING MEDICATION AND PSYCHOTHERAPIES, ALTHOUGH THEIR SUCCESS RATE IS LIMITED. SOME PHARMACOLOGICAL THERAPIES BASED ON THE HPA AXIS ARE CURRENTLY BEING TESTED IN CLINICAL TRIALS AND CHANGES IN HPA AXIS BIOMARKERS HAVE BEEN FOUND TO OCCUR IN RESPONSE NOT ONLY TO PHARMACOLOGICAL TREATMENTS, BUT ALSO TO PSYCHOTHERAPY-INCLUDING THE EPIGENETIC MODIFICATION OF THE GR GENE. PSYCHOTHERAPIES ARE CONSIDERED TO BE THE FIRST LINE TREATMENTS FOR PTSD IN SOME GUIDELINES, EVEN THOUGH THEY ARE EFFECTIVE FOR SOME, BUT NOT FOR ALL PATIENTS WITH PTSD. THIS REVIEW AIMS TO ADDRESS HOW KNOWLEDGE OF THE HPA AXIS-RELATED GENETIC MAKEUP CAN INFORM AND PREDICT THE OUTCOMES OF PSYCHOTHERAPEUTIC TREATMENTS. 2020