1 4343 162 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 2 6729 40 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 3 291 41 AGING AND STRESS: PAST HYPOTHESES, PRESENT APPROACHES AND PERSPECTIVES. BRAIN AGING HAS BEEN SUGGESTED TO BE CONDITIONED BY AN EXCESSIVE GLUCOCORTIOID SECRETION LEADING TO DAMAGES ON BRAIN AREAS INVOLVED NOT ONLY IN COGNITIVE AND EMOTIONAL PROCESSES BUT ALSO IN THE CONTROL OF THE ACTIVITY OF THE HYPOTHALAMIC-PITUITARY ADRENAL AXIS. THIS REVIEW DESCRIBES SOME OF THE HYPOTHESIS THAT TRY TO EXPLAIN THE RELATION BETWEEN THE DYSREGULATION OF THE STRESS RESPONSE AND BRAIN AGING, FOCUSING ON CORTICOSTERONE BUT ALSO ON NEUROTRANSMISSION IN THE HIPPOCAMPUS, THE PREFRONTAL CORTEX AND THE AMYGDALA. MOREOVER, DIFFERENT MOLECULAR FACTORS CAN ACCOUNT FOR AN ENHANCED VULNERABILITY OF THE AGED BRAIN TO STRESS EXPOSURE, SPECIALLY FOR RESILIENCE. AMONG THEM, GOOD CANDIDATES COULD BE THOSE MECHANISMS DETERMINING THE LEVELS OF CORTICOSTERONE IN THE BRAIN, SEVERAL MOLECULES DOWNSTREAM GLUCOCORTICOID RECEPTOR ACTIVATION (IE: HEAT SHOCK PROTEINS, BAG-1) OR EVEN THE EPIGENETIC PROGRAMMING OF THE HPA AXIS IN EARLY STAGES. IN CONCLUSION, GENETIC AND ENVIRONMENTAL FACTORS (EARLY LIFE STRESS, CHRONIC STRESS DURING ADULTHOOD) CAN PRODUCE AN ENHANCED VULNERABILITY AND A REDUCED RESILIENCE OF THE BRAIN TO SUBSEQUENT STRESS EXPOSURES OR TO METABOLIC CHALLENGES LEADING, IN TURN, TO AN UNSUCCESSFUL AGING OF THE BRAIN. HOWEVER, RESULTS OBTAINED WITH THE USE OF THE ENVIRONMENTAL ENRICHMENT MODEL IN ANIMALS, ADDED TO SEVERAL RESULTS IN HUMANS ALSO DESCRIBED IN THIS REVIEW SUGGEST THAT POSITIVE ENVIRONMENTAL FACTORS (COGNITIVE-DEMANDING TASKS OR PHYSICAL EXERCISE) CAN HELP TO MAINTAIN NEURONAL PLASTICITY DURING AGING AND TO PROTECT THE BRAIN AGAINST THE DAMAGING EFFECTS OF STRESS EXPOSURE. 2011 4 3405 37 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 3151 37 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 6 6228 30 THE LINKS BETWEEN STRESS AND DEPRESSION: PSYCHONEUROENDOCRINOLOGICAL, GENETIC, AND ENVIRONMENTAL INTERACTIONS. THE ROLE OF STRESS IN THE ORIGIN AND DEVELOPMENT OF DEPRESSION MAY BE CONCEIVED AS THE RESULT OF MULTIPLE CONVERGING FACTORS, INCLUDING THE CHRONIC EFFECT OF ENVIRONMENTAL STRESSORS AND THE LONG-LASTING EFFECTS OF STRESSFUL EXPERIENCES DURING CHILDHOOD, ALL OF WHICH MAY INDUCE PERSISTENT HYPERACTIVITY OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS. THESE CHANGES, INCLUDING INCREASED AVAILABILITY OF CORTICOTROPIN-RELEASING FACTOR AND CORTISOL, ARE ALSO ASSOCIATED WITH HYPERACTIVITY OF THE AMYGDALA, HYPOACTIVITY OF THE HIPPOCAMPUS, AND DECREASED SEROTONERGIC NEUROTRANSMISSION, WHICH TOGETHER RESULT IN INCREASED VULNERABILITY TO STRESS. THE ROLE OF OTHER MONOAMINERGIC NEUROTRANSMITTERS, GENETIC POLYMORPHISMS, EPIGENETIC MECHANISMS, INFLAMMATORY PROCESSES, AND ALTERED COGNITIVE PROCESSING HAS ALSO BEEN CONSIDERED IN THE DEVELOPMENT OF A COMPREHENSIVE MODEL OF THE INTERACTIONS BETWEEN DIFFERENT FACTORS OF VULNERABILITY. FURTHER UNDERSTANDING OF THE UNDERLYING MECHANISMS THAT LINK THESE FACTORS MAY CONTRIBUTE SIGNIFICANTLY TO THE DEVELOPMENT OF MORE EFFECTIVE TREATMENTS AND PREVENTIVE STRATEGIES IN THE INTERFACE BETWEEN STRESS AND MOOD DISORDERS. 2016 7 5662 26 SEXUAL DIMORPHISM IN GLUCOCORTICOID STRESS RESPONSE. CHRONIC STRESS IS ENCOUNTERED IN OUR EVERYDAY LIFE AND IS THOUGHT TO CONTRIBUTE TO A NUMBER OF DISEASES. MANY OF THESE STRESS-RELATED DISORDERS DISPLAY A SEX BIAS. BECAUSE GLUCOCORTICOID HORMONES ARE THE MAIN BIOLOGICAL MEDIATOR OF CHRONIC STRESS, RESEARCHERS HAVE BEEN INTERESTED IN UNDERSTANDING THE SEXUAL DIMORPHISM IN GLUCOCORTICOID STRESS RESPONSE TO BETTER EXPLAIN THE SEX BIAS IN STRESS-RELATED DISEASES. ALTHOUGH NOT YET DEMONSTRATED FOR GLUCOCORTICOID REGULATION, SEX CHROMOSOMES DO INFLUENCE SEX-SPECIFIC BIOLOGY AS SOON AS CONCEPTION. THEN A TRANSIENT RISE IN TESTOSTERONE START TO SHAPE THE MALE BRAIN DURING THE PRENATAL PERIOD DIFFERENTLY TO THE FEMALE BRAIN. THESE ORGANIZATIONAL EFFECTS ARE COMPLETED JUST BEFORE PUBERTY. THE CEREBRAL REGIONS IMPLICATED IN GLUCOCORTICOID REGULATION AT REST AND AFTER STRESS ARE THEREBY IMPACTED IN A SEX-SPECIFIC MANNER. AFTER PUBERTY, THE HIGH LEVELS OF ALL GONADAL HORMONES WILL INTERACT WITH GLUCOCORTICOID HORMONES IN SPECIFIC CROSSTALK THROUGH THEIR RESPECTIVE NUCLEAR RECEPTORS. IN ADDITION, STRESS OCCURRING EARLY IN LIFE, IN PARTICULAR DURING THE PRENATAL PERIOD AND IN ADOLESCENCE WILL PRIME IN THE LONG-TERM GLUCOCORTICOID STRESS RESPONSE THROUGH EPIGENETIC MECHANISMS, AGAIN IN A SEX-SPECIFIC MANNER. ALTOGETHER, VARIOUS MOLECULAR MECHANISMS EXPLAIN SEX-SPECIFIC GLUCOCORTICOID STRESS RESPONSES THAT DO NOT EXCLUDE IMPORTANT GENDER EFFECTS IN HUMANS. 2021 8 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 9 2520 28 EPIGENETICS AND THE GLUCOCORTICOID RECEPTOR: A REVIEW OF THE IMPLICATIONS IN DEPRESSION. DEPRESSION IS A SERIOUS PSYCHIATRIC DISORDER THAT EFFECTS AT LEAST 350 MILLION PEOPLE WORLDWIDE TODAY. DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS (HPAA) IS A ROBUST FINDING IN THE PATHOPHYSIOLOGY OF DEPRESSION. THIS DYSREGULATION IS HYPOTHESIZED TO RESULT FROM ALTERED CENTRAL GLUCOCORTICOID RECEPTOR (GR) LEVELS AND/OR FUNCTION AS A CONSEQUENCE OF CHRONIC GLUCOCORTICOID (GC) RELEASE, LEADING TO RECEPTOR RESISTANCE. PIVOTAL ANIMAL AND HUMAN RESEARCH TO DATE HAS IDENTIFIED THAT EARLY LIFE EXPOSURE TO PROLONGED LEVELS OF GCS, STRESS AND/OR DEPRESSION, CAN INDUCE EPIGENETIC MODIFICATIONS AT KEY REGIONS ON THE GR GENE THAT LEAD TO ALTERATIONS IN GR EXPRESSION AND FUNCTION. EPIGENETICS PROVIDES AN ATTRACTIVE MECHANISM TO EXPLAIN HOW ONES' GENES AND ENVIRONMENT CAN INTERACT TO PRODUCE DIFFERENT DISEASE PHENOTYPES. THIS REVIEW AIMS TO COMPILE THE INFORMATION THAT HAS BEEN COLLECTED TO DATE AND TO IDENTIFY KEY AREAS FOR FURTHER INVESTIGATION. 2016 10 997 25 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 11 1981 31 EPIGENETIC ALTERATIONS IN DNA AND HISTONE MODIFICATIONS CAUSED BY DEPRESSION AND ANTIDEPRESSANT DRUGS: LESSONS FROM THE RODENT MODELS. EPIGENETIC MODIFICATIONS REGULATE CHROMATIN FOLDING AND FUNCTION. EPIGENETIC MECHANISMS REGULATE TRANSCRIPTION MEDIATING EFFECTS OF VARIOUS STIMULI ON GENE EXPRESSION. THESE MECHANISMS ARE INVOLVED IN TRANSCRIPTIONAL CONTROL IN VARIOUS PHYSIOLOGICAL AND PATHOLOGICAL CONDITIONS INCLUDING NEUROPSYCHIATRIC DISORDERS AND BEHAVIORAL ABNORMALITIES SUCH AS DEPRESSION. IN RODENTS, EXPOSURE TO CHRONIC SOCIAL STRESS WAS SHOWN TO INDUCE BEHAVIORAL IMPAIRMENTS AND MEMORY/LEARNING DEFICITS THAT RESEMBLE DEPRESSIVE-LIKE PHENOTYPE IN HUMANS. THE RODENT MODELS OF CHRONIC STRESS WERE WIDELY USED TO STUDY MOLECULAR MECHANISMS OF DEPRESSION. IN THESE MODELS, EARLY EXPOSURE TO CHRONIC STRESS SUCH AS PRENATAL OR POSTNATAL STRESS INDUCES LONG-TERM HYPERACTIVE STRESS RESPONSES, BEHAVIORAL ABNORMALITIES, AND FUNCTIONAL IMPAIRMENTS IN BRAIN FUNCTION THAT PERSIST IN ADULTHOOD. FURTHERMORE, THESE ALTERATIONS CAN BE TRANSMITTED TO OFFSPRING OF CHRONICALLY STRESSED ANIMALS ACROSS SEVERAL GENERATIONS. MOLECULAR STUDIES IN ANIMAL MODELS SHOWED THAT CHRONIC STRESS INDUCES STABLE EPIGENETIC CHANGES IN SPECIFIC BRAIN REGIONS, PRIMARILY IN THE LIMBIC SYSTEM. THESE CHANGES LEAD TO LONG-LASTING ABNORMALITIES IN BEHAVIOR THAT PERSIST IN ADULTHOOD AND CAN BE TRANSMITTED TO OFFSPRING. TREATMENT WITH EPIGENETICALLY ACTIVE ANTIDEPRESSANTS DISRUPTS THE ABNORMAL STRESS-INDUCED EPIGENETIC PROGRAMMING AND PROVIDES EPIGENETIC PATTERNS THAT RESEMBLE EPIGENETIC BACKGROUND OF STRESS RESILIENT INDIVIDUALS. 2017 12 5160 34 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 13 2264 44 EPIGENETIC PROGRAMMING BY STRESS AND GLUCOCORTICOIDS ALONG THE HUMAN LIFESPAN. PSYCHOSOCIAL STRESS TRIGGERS A SET OF BEHAVIORAL, NEURAL, HORMONAL, AND MOLECULAR RESPONSES THAT CAN BE A DRIVING FORCE FOR SURVIVAL WHEN ADAPTIVE AND TIME-LIMITED, BUT MAY ALSO CONTRIBUTE TO A HOST OF DISEASE STATES IF DYSREGULATED OR CHRONIC. THE BENEFICIAL OR DETRIMENTAL EFFECTS OF STRESS ARE LARGELY MEDIATED BY THE HYPOTHALAMIC-PITUITARY AXIS, A HIGHLY CONSERVED NEUROHORMONAL CASCADE THAT CULMINATES IN SYSTEMIC SECRETION OF GLUCOCORTICOIDS. GLUCOCORTICOIDS ACTIVATE THE GLUCOCORTICOID RECEPTOR, A UBIQUITOUS NUCLEAR RECEPTOR THAT NOT ONLY CAUSES WIDESPREAD CHANGES IN TRANSCRIPTIONAL PROGRAMS, BUT ALSO INDUCES LASTING EPIGENETIC MODIFICATIONS IN MANY TARGET TISSUES. WHILE THE EPIGENOME REMAINS SENSITIVE TO STRESSORS THROUGHOUT LIFE, WE PROPOSE TWO KEY PRINCIPLES THAT MAY GOVERN THE EPIGENETICS OF STRESS AND GLUCOCORTICOIDS ALONG THE LIFESPAN: FIRST, THE PRESENCE OF DISTINCT LIFE PERIODS, DURING WHICH THE EPIGENOME SHOWS HEIGHTENED PLASTICITY TO STRESS EXPOSURE, SUCH AS IN EARLY DEVELOPMENT AND AT ADVANCED AGE; AND, SECOND, THE POTENTIAL OF STRESS-INDUCED EPIGENETIC CHANGES TO ACCUMULATE THROUGHOUT LIFE BOTH IN SELECT CHROMATIN REGIONS AND AT THE GENOME-WIDE LEVEL. THESE PRINCIPLES HAVE IMPORTANT CLINICAL AND TRANSLATIONAL IMPLICATIONS, AND THEY SHOW STRIKING PARALLELS WITH THE EXISTENCE OF SENSITIVE DEVELOPMENTAL PERIODS AND THE CUMULATIVE IMPACT OF STRESSFUL EXPERIENCES ON THE DEVELOPMENT OF STRESS-RELATED PHENOTYPES. WE HOPE THAT THIS CONCEPTUAL MECHANISTIC FRAMEWORK WILL STIMULATE FRUITFUL RESEARCH THAT AIMS AT UNRAVELING THE MOLECULAR PATHWAYS THROUGH WHICH OUR LIFE STORIES SCULPT GENOMIC FUNCTION TO CONTRIBUTE TO COMPLEX BEHAVIORAL AND SOMATIC PHENOTYPES. 2017 14 678 39 BRAIN DEVELOPMENT UNDER STRESS: HYPOTHESES OF GLUCOCORTICOID ACTIONS REVISITED. ONE OF THE CONUNDRUMS IN TODAY'S STRESS RESEARCH IS WHY SOME INDIVIDUALS FLOURISH AND OTHERS PERISH UNDER SIMILAR STRESSFUL CONDITIONS. IT IS RECOGNIZED THAT THIS INDIVIDUAL VARIABILITY IN ADAPTATION TO STRESS DEPENDS ON THE OUTCOME OF THE INTERACTION OF GENETIC AND COGNITIVE/EMOTIONAL INPUTS IN WHICH GLUCOCORTICOID HORMONES AND RECEPTORS PLAY A CRUCIAL ROLE. HENCE ONE APPROACH TOWARDS UNDERSTANDING INDIVIDUAL VARIATION IN STRESS COPING IS HOW GLUCOCORTICOID ACTIONS CAN CHANGE FROM PROTECTIVE TO HARMFUL. TO ADDRESS THIS QUESTION WE FOCUS ON FOUR HYPOTHESES THAT ARE CONNECTED AND NOT MUTUAL EXCLUSIVE. FIRST, THE CLASSICAL GLUCOCORTICOID CASCADE HYPOTHESIS, IN WHICH THE INABILITY TO COPE WITH CHRONIC STRESS CAUSES A VICIOUS CYCLE OF EXCESS GLUCOCORTICOID AND DOWNREGULATION OF GLUCOCORTICOID RECEPTORS (GR) IN THE HIPPOCAMPUS TRIGGERING A FEED-FORWARD CASCADE OF DEGENERATION AND DISEASE. SECOND, THE BALANCE HYPOTHESIS, WHICH TAKES ALSO THE LIMBIC MINERALOCORTICOID RECEPTORS (MR) INTO ACCOUNT AND PROPOSES THAT AN INTEGRAL LIMBIC MR:GR IMBALANCE IS CAUSAL TO ALTERED PROCESSING OF INFORMATION IN CIRCUITS UNDERLYING FEAR, REWARD, SOCIAL BEHAVIOUR AND RESILIENCE, DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS AND IMPAIRMENT OF BEHAVIOURAL ADAPTATION. THE MR:GR BALANCE IS ALTERED BY GENE VARIANTS OF THESE RECEPTOR COMPLEXES AND EXPERIENCE-RELATED FACTORS, WHICH CAN INDUCE LASTING EPIGENETIC CHANGES IN THE EXPRESSION OF THESE RECEPTORS. A PARTICULAR POTENT EPIGENETIC STIMULUS IS THE MATERNAL ENVIRONMENT WHICH IS FUNDAMENTAL FOR THE MATERNAL MEDIATION HYPOTHESIS. THE OUTCOME OF PERINATAL GENE X ENVIRONMENT INTERACTION, AND THUS OF MR:GR-MEDIATED FUNCTIONS DEPENDS HOWEVER, ON THE DEGREE OF 'MATCHING' WITH ENVIRONMENTAL DEMANDS IN LATER LIFE. THE PREDICTIVE ADAPTATION HYPOTHESIS THEREFORE PRESENTS A CONCEPTUAL FRAMEWORK TO EXAMINE THE ROLE OF GLUCOCORTICOIDS IN UNDERSTANDING INDIVIDUAL PHENOTYPIC DIFFERENCES IN STRESS-RELATED BEHAVIOURS OVER THE LIFESPAN. 2010 15 3313 28 HIPPOCAMPAL BDNF IN PHYSIOLOGICAL CONDITIONS AND SOCIAL ISOLATION. EXPOSURE OF AN ORGANISM TO CHRONIC PSYCHOSOCIAL STRESS MAY AFFECT BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) EXPRESSION THAT HAS BEEN IMPLICATED IN THE ETIOLOGY OF PSYCHIATRIC DISORDERS, SUCH AS DEPRESSION. GIVEN THAT DEPRESSION IN HUMANS HAS BEEN LINKED WITH SOCIAL STRESS, THE CHRONIC SOCIAL STRESS PARADIGMS FOR MODELING PSYCHIATRIC DISORDERS IN ANIMALS HAVE THUS BEEN DEVELOPED. CHRONIC SOCIAL ISOLATION IN ANIMAL MODELS GENERALLY CAUSES CHANGES IN HYPOTHALAMIC-PITUITARY-ADRENAL AXIS FUNCTIONING, ASSOCIATED WITH ANXIETY- AND DEPRESSIVE-LIKE BEHAVIORS. ALSO, THIS CHRONIC STRESS CAUSES DOWNREGULATION OF BDNF PROTEIN AND MRNA IN THE HIPPOCAMPUS, A STRESS-SENSITIVE BRAIN REGION CLOSELY RELATED TO THE PATHOPHYSIOLOGY OF DEPRESSION. IN THIS REVIEW, WE DISCUSS THE CURRENT KNOWLEDGE REGARDING THE STRUCTURE, FUNCTION, INTRACELLULAR SIGNALING, INTER-INDIVIDUAL DIFFERENCES AND EPIGENETIC REGULATION OF BDNF IN BOTH PHYSIOLOGICAL CONDITIONS AND DEPRESSION AND CHANGES IN CORTICOSTERONE LEVELS, AS A MARKER OF STRESS RESPONSE. SINCE BDNF LEVELS ARE AGE DEPENDENT IN HUMANS AND RODENTS, THIS REVIEW WILL ALSO HIGHLIGHT THE EFFECTS OF ADOLESCENT AND ADULT CHRONIC SOCIAL ISOLATION MODELS OF BOTH GENDERS ON THE BDNF EXPRESSION. 2017 16 1754 31 EARLY LIFE STRESS, THE DEVELOPMENT OF AGGRESSION AND NEUROENDOCRINE AND NEUROBIOLOGICAL CORRELATES: WHAT CAN WE LEARN FROM ANIMAL MODELS? EARLY LIFE STRESS (CHILD AND ADOLESCENT ABUSE, NEGLECT AND TRAUMA) INDUCES ROBUST ALTERATIONS IN EMOTIONAL AND SOCIAL FUNCTIONING RESULTING IN ENHANCED RISK FOR THE DEVELOPMENT OF PSYCHOPATHOLOGIES SUCH AS MOOD AND AGGRESSIVE DISORDERS. HERE, AN OVERVIEW IS GIVEN ON RECENT FINDINGS IN PRIMATE AND RODENT MODELS OF EARLY LIFE STRESS, DEMONSTRATING THAT CHRONIC DEPRIVATION OF EARLY MATERNAL CARE AS WELL AS CHRONIC DEPRIVATION OF EARLY PHYSICAL INTERACTIONS WITH PEERS ARE PROFOUND RISK FACTORS FOR THE DEVELOPMENT OF INAPPROPRIATE AGGRESSIVE BEHAVIORS. ALTERATIONS IN THE HYPOTHALAMIC-PITUITARY-ADRENOCORTICAL (HPA), VASOPRESSIN AND SEROTONIN SYSTEMS AND THEIR RELEVANCE FOR THE REGULATION OF AGGRESSION ARE DISCUSSED. DATA SUGGEST THAT SOCIAL DEPRIVATION-INDUCED INAPPROPRIATE FORMS OF AGGRESSION ARE ASSOCIATED WITH HIGH OR LOW HPA AXIS (RE)ACTIVITY AND A GENERALLY LOWER FUNCTIONING OF THE SEROTONIN SYSTEM IN ADULTHOOD. MOREOVER, GENETIC AND EPIGENETIC MODIFICATIONS IN HPA AND SEROTONIN SYSTEMS INFLUENCE THE OUTCOME OF EARLY LIFE STRESS AND MAY EVEN MODERATE ADVERSE EFFECTS OF EARLY SOCIAL DEPRIVATION ON AGGRESSION. A MORE COMPREHENSIVE STUDY OF AGGRESSION, NEUROENDOCRINE, NEUROBIOLOGICAL AND (EPI)GENETIC CORRELATES OF EARLY LIFE STRESS USING ANIMAL MODELS IS NECESSARY TO PROVIDE A BETTER UNDERSTANDING OF THE INVASIVE AGGRESSIVE DEFICITS OBSERVED IN HUMANS EXPOSED TO CHILD MALTREATMENT. 2009 17 4642 37 NEURONAL PLASTICITY: A LINK BETWEEN STRESS AND MOOD DISORDERS. ALTHOUGH STRESS REPRESENTS THE MAJOR ENVIRONMENTAL ELEMENT OF SUSCEPTIBILITY FOR MOOD DISORDERS, THE RELATIONSHIP BETWEEN STRESS AND DISEASE REMAINS TO BE FULLY ESTABLISHED. IN THE PRESENT ARTICLE WE REVIEW THE EVIDENCE IN SUPPORT FOR A ROLE OF NEURONAL PLASTICITY, AND IN PARTICULAR OF NEUROTROPHIC FACTORS. EVEN THOUGH DECREASED LEVELS OF NOREPINEPHRINE AND SEROTONIN MAY UNDERLIE DEPRESSIVE SYMPTOMS, COMPELLING EVIDENCE NOW SUGGESTS THAT MOOD DISORDERS ARE CHARACTERIZED BY REDUCED NEURONAL PLASTICITY, WHICH CAN BE BROUGHT ABOUT BY EXPOSURE TO STRESS AT DIFFERENT STAGES OF LIFE. INDEED THE EXPRESSION OF NEUROTROPHIC MOLECULES, SUCH AS THE NEUROTROPHIN BDNF, IS REDUCED IN DEPRESSED SUBJECTS AS WELL AS IN EXPERIMENTAL ANIMALS EXPOSED TO ADVERSE EXPERIENCE AT EARLY STAGES OF LIFE OR AT ADULTHOOD. THESE CHANGES SHOW AN ANATOMICAL SPECIFICITY AND MIGHT BE SUSTAINED BY EPIGENETIC MECHANISMS. PHARMACOLOGICAL INTERVENTION MAY NORMALIZE SUCH DEFECTS AND IMPROVE NEURONAL FUNCTION THROUGH THE MODULATION OF THE SAME FACTORS THAT ARE DEFECTIVE IN DEPRESSION. SEVERAL STUDIES HAVE DEMONSTRATED THAT CHRONIC, BUT NOT ACUTE, ANTIDEPRESSANT TREATMENT INCREASES THE EXPRESSION OF BDNF AND MAY ENHANCE ITS LOCALIZATION AT SYNAPTIC LEVEL. ANTIDEPRESSANT TREATMENT CAN NORMALIZE DEFICITS IN NEUROTROPHIN EXPRESSION PRODUCED BY CHRONIC STRESS PARADIGMS, BUT MAY ALSO ALTER THE MODULATION OF BDNF UNDER ACUTE STRESSFUL CONDITIONS. IN SUMMARY, THERE IS GOOD AGREEMENT IN CONSIDERING NEURONAL PLASTICITY, AND THE EXPRESSION OF KEY PROTEINS SUCH AS THE NEUROTROPHIN BDNF, AS A CENTRAL PLAYER FOR THE EFFECTS OF STRESS ON BRAIN FUNCTION AND ITS IMPLICATION FOR PSYCHOPATHOLOGY. ACCORDINGLY, EFFECTIVE TREATMENTS SHOULD NOT LIMIT THEIR EFFECTS TO THE CONTROL OF NEUROTRANSMITTER AND HORMONAL DYSFUNCTIONS, BUT SHOULD BE ABLE TO NORMALIZE DEFECTIVE MECHANISMS THAT SUSTAIN THE IMPAIRMENT OF NEURONAL PLASTICITY. 2009 18 3092 27 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 19 6278 35 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 20 4118 34 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