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 2 101 32 A RAT METHYL-SEQ PLATFORM TO IDENTIFY EPIGENETIC CHANGES ASSOCIATED WITH STRESS EXPOSURE. AS GENOMES OF A WIDER VARIETY OF ANIMALS BECOME AVAILABLE, THERE IS AN INCREASING NEED FOR TOOLS THAT CAN CAPTURE DYNAMIC EPIGENETIC CHANGES IN THESE ANIMAL MODELS. THE RAT IS ONE PARTICULAR MODEL ANIMAL WHERE AN EPIGENETIC TOOL CAN COMPLEMENT MANY PHARMACOLOGICAL AND BEHAVIORAL STUDIES TO PROVIDE INSIGHTFUL MECHANISTIC INFORMATION. TO THIS END, WE ADAPTED THE SURESELECT TARGET CAPTURE SYSTEM (REFERRED TO AS METHYL-SEQ) FOR THE RAT, WHICH CAN ASSESS DNA METHYLATION LEVELS ACROSS THE RAT GENOME. THE RAT DESIGN TARGETED PROMOTERS, CPG ISLANDS, ISLAND SHORES, AND GC-RICH REGIONS FROM ALL REFSEQ GENES. TO IMPLEMENT THE PLATFORM ON A RAT EXPERIMENT, MALE SPRAGUE DAWLEY RATS WERE EXPOSED TO CHRONIC VARIABLE STRESS FOR 3 WEEKS, AFTER WHICH BLOOD SAMPLES WERE COLLECTED FOR GENOMIC DNA EXTRACTION. METHYL-SEQ LIBRARIES WERE CONSTRUCTED FROM THE RAT DNA SAMPLES BY SHEARING, ADAPTER LIGATION, TARGET ENRICHMENT, BISULFITE CONVERSION, AND MULTIPLEXING. LIBRARIES WERE SEQUENCED ON A NEXT-GENERATION SEQUENCING PLATFORM AND THE SEQUENCED READS WERE ANALYZED TO IDENTIFY DMRS BETWEEN DNA OF STRESSED AND UNSTRESSED RATS. TOP CANDIDATE DMRS WERE INDEPENDENTLY VALIDATED BY BISULFITE PYROSEQUENCING TO CONFIRM THE ROBUSTNESS OF THE PLATFORM. RESULTS DEMONSTRATE THAT THE RAT METHYL-SEQ PLATFORM IS A USEFUL EPIGENETIC TOOL THAT CAN CAPTURE METHYLATION CHANGES INDUCED BY EXPOSURE TO STRESS. 2018 3 6613 25 ULTRADEEP BISULFITE SEQUENCING ANALYSIS OF DNA METHYLATION PATTERNS IN MULTIPLE GENE PROMOTERS BY 454 SEQUENCING. WE DEVELOPED A NOVEL APPROACH FOR CONDUCTING MULTISAMPLE, MULTIGENE, ULTRADEEP BISULFITE SEQUENCING ANALYSIS OF DNA METHYLATION PATTERNS IN CLINICAL SAMPLES. A MASSIVELY PARALLEL SEQUENCING-BY-SYNTHESIS METHOD (454 SEQUENCING) WAS USED TO DIRECTLY SEQUENCE >100 BISULFITE PCR PRODUCTS IN A SINGLE SEQUENCING RUN WITHOUT SUBCLONING. WE SHOWED THE UTILITY, ROBUSTNESS, AND SUPERIORITY OF THIS APPROACH BY ANALYZING METHYLATION IN 25 GENE-RELATED CPG RICH REGIONS FROM >40 CASES OF PRIMARY CELLS, INCLUDING NORMAL PERIPHERAL BLOOD LYMPHOCYTES, ACUTE LYMPHOBLASTIC LEUKEMIA (ALL), CHRONIC LYMPHOCYTIC LEUKEMIA (CLL), FOLLICULAR LYMPHOMA (FL), AND MANTLE CELL LYMPHOMA (MCL). A TOTAL OF 294,631 SEQUENCES WAS GENERATED WITH AN AVERAGE READ LENGTH OF 131 BP. ON AVERAGE, >1,600 INDIVIDUAL SEQUENCES WERE GENERATED FOR EACH PCR AMPLICON FAR BEYOND THE FEW CLONES (<20) TYPICALLY ANALYZED BY TRADITIONAL BISULFITE SEQUENCING. COMPREHENSIVE ANALYSIS OF CPG METHYLATION PATTERNS AT A SINGLE DNA MOLECULE LEVEL USING CLUSTERING ALGORITHMS REVEALED DIFFERENTIAL METHYLATION PATTERNS BETWEEN DISEASES. A SIGNIFICANT INCREASE IN METHYLATION WAS DETECTED IN ALL AND FL SAMPLES COMPARED WITH CLL AND MCL. FURTHERMORE, A PROGRESSIVE SPREADING OF METHYLATION WAS DETECTED FROM THE PERIPHERY TOWARD THE CENTER OF SELECT CPG ISLANDS IN THE ALL AND FL SAMPLES. THE ULTRADEEP SEQUENCING ALSO ALLOWED SIMULTANEOUS ANALYSIS OF GENETIC AND EPIGENETIC DATA AND REVEALED AN ASSOCIATION BETWEEN A SINGLE NUCLEOTIDE POLYMORPHISM AND THE METHYLATION PRESENT IN THE LRP1B PROMOTER. THIS NEW GENERATION OF METHYLOME SEQUENCING WILL PROVIDE DIGITAL PROFILES OF ABERRANT DNA METHYLATION FOR INDIVIDUAL HUMAN CANCERS AND OFFERS A ROBUST METHOD FOR THE EPIGENETIC CLASSIFICATION OF TUMOR SUBTYPES. 2007 4 666 37 BLOOD-BASED DNA METHYLATION BIOMARKERS FOR TYPE 2 DIABETES: POTENTIAL FOR CLINICAL APPLICATIONS. TYPE 2 DIABETES (T2D) IS A LEADING CAUSE OF DEATH AND DISABILITY WORLDWIDE. IT IS A CHRONIC METABOLIC DISORDER THAT DEVELOPS DUE TO AN INTERPLAY OF GENETIC, LIFESTYLE, AND ENVIRONMENTAL FACTORS. THE BIOLOGICAL ONSET OF THE DISEASE OCCURS LONG BEFORE CLINICAL SYMPTOMS DEVELOP, THUS THE SEARCH FOR EARLY DIAGNOSTIC AND PROGNOSTIC BIOMARKERS, WHICH COULD FACILITATE INTERVENTION STRATEGIES TO PREVENT OR DELAY DISEASE PROGRESSION, HAS INCREASED CONSIDERABLY IN RECENT YEARS. EPIGENETIC MODIFICATIONS REPRESENT IMPORTANT LINKS BETWEEN GENETIC, ENVIRONMENTAL AND LIFESTYLE CUES AND INCREASING EVIDENCE IMPLICATE ALTERED EPIGENETIC MARKS SUCH AS DNA METHYLATION, THE MOST CHARACTERIZED AND WIDELY STUDIED EPIGENETIC MECHANISM, IN THE PATHOGENESIS OF T2D. THIS REVIEW PROVIDES AN UPDATE OF THE CURRENT STATUS OF DNA METHYLATION AS A BIOMARKER FOR T2D. FOUR DATABASES, SCOPUS, PUBMED, COCHRANE CENTRAL, AND GOOGLE SCHOLAR WERE SEARCHED FOR STUDIES INVESTIGATING DNA METHYLATION IN BLOOD. THIRTY-SEVEN STUDIES WERE IDENTIFIED, AND ARE SUMMARIZED WITH RESPECT TO POPULATION CHARACTERISTICS, BIOLOGICAL SOURCE, AND METHOD OF DNA METHYLATION QUANTIFICATION (GLOBAL, CANDIDATE GENE OR GENOME-WIDE). WE HIGHLIGHT THAT DIFFERENTIAL METHYLATION OF THE TCF7L2, KCNQ1, ABCG1, TXNIP, PHOSPHO1, SREBF1, SLC30A8, AND FTO GENES IN BLOOD ARE REPRODUCIBLY ASSOCIATED WITH T2D IN DIFFERENT POPULATION GROUPS. THESE GENES SHOULD BE PRIORITIZED AND REPLICATED IN LONGITUDINAL STUDIES ACROSS MORE POPULATIONS IN FUTURE STUDIES. FINALLY, WE DISCUSS THE LIMITATIONS FACED BY DNA METHYLATION STUDIES, WHICH INCLUDE INCLUDING INTERPATIENT VARIABILITY, CELLULAR HETEROGENEITY, AND LACK OF ACCOUNTING FOR STUDY CONFOUNDERS. THESE LIMITATIONS AND CHALLENGES MUST BE OVERCOME BEFORE THE IMPLEMENTATION OF BLOOD-BASED DNA METHYLATION BIOMARKERS INTO A CLINICAL SETTING. WE EMPHASIZE THE NEED FOR LONGITUDINAL PROSPECTIVE STUDIES TO SUPPORT THE ROBUSTNESS OF THE CURRENT FINDINGS OF THIS REVIEW. 2018 5 5872 24 SUSTAINED TNF-ALPHA STIMULATION LEADS TO TRANSCRIPTIONAL MEMORY THAT GREATLY ENHANCES SIGNAL SENSITIVITY AND ROBUSTNESS. TRANSCRIPTIONAL MEMORY ALLOWS CERTAIN GENES TO RESPOND TO PREVIOUSLY EXPERIENCED SIGNALS MORE ROBUSTLY. HOWEVER, WHETHER AND HOW THE KEY PROINFLAMMATORY CYTOKINE TNF-ALPHA MEDIATES TRANSCRIPTIONAL MEMORY ARE POORLY UNDERSTOOD. USING HEK293F CELLS AS A MODEL SYSTEM, WE REPORT THAT SUSTAINED TNF-ALPHA STIMULATION INDUCES TRANSCRIPTIONAL MEMORY DEPENDENT ON TET ENZYMES. THE HYPOMETHYLATED STATUS OF TRANSCRIPTIONAL REGULATORY REGIONS CAN BE INHERITED, FACILITATING NF-KAPPAB BINDING AND MORE ROBUST SUBSEQUENT ACTIVATION. A HIGH INITIAL METHYLATION LEVEL AND CPG DENSITY AROUND KAPPAB SITES ARE CORRELATED WITH THE FUNCTIONAL POTENTIAL OF TRANSCRIPTIONAL MEMORY MODULES. INTERESTINGLY, THE CALCB GENE, ENCODING THE PROVEN MIGRAINE THERAPEUTIC TARGET CGRP, EXHIBITS THE BEST TRANSCRIPTIONAL MEMORY. A NEIGHBORING PRIMATE-SPECIFIC ENDOGENOUS RETROVIRUS STIMULATES MORE RAPID, MORE STRONG, AND AT LEAST 100-FOLD MORE SENSITIVE CALCB INDUCTION IN SUBSEQUENT TNF-ALPHA STIMULATION. OUR STUDY REVEALS THAT TNF-ALPHA-MEDIATED TRANSCRIPTIONAL MEMORY IS GOVERNED BY ACTIVE DNA DEMETHYLATION AND GREATLY SENSITIZES MEMORY GENES TO MUCH LOWER DOSES OF INFLAMMATORY CUES. 2020 6 940 22 CHRONIC LYMPHOCYTIC LEUKEMIA AND MANTLE CELL LYMPHOMA: CROSSROADS OF GENETIC AND MICROENVIRONMENT INTERACTIONS. CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) AND MANTLE CELL LYMPHOMA (MCL) ARE 2 WELL-DEFINED ENTITIES THAT DIVERGE IN THEIR BASIC PATHOGENIC MECHANISMS AND CLINICAL EVOLUTION BUT THEY SHARE EPIDEMIOLOGICAL CHARACTERISTICS, CELLS OF ORIGIN, MOLECULAR ALTERATIONS, AND CLINICAL FEATURES THAT DIFFER FROM OTHER LYMPHOID NEOPLASMS. CLL AND MCL ARE CLASSICALLY CONSIDERED INDOLENT AND AGGRESSIVE NEOPLASMS, RESPECTIVELY. HOWEVER, THE CLINICAL EVOLUTION OF BOTH TUMORS IS VERY HETEROGENEOUS, WITH SUBSETS OF PATIENTS HAVING STABLE DISEASE FOR A LONG TIME WHEREAS OTHERS REQUIRE IMMEDIATE INTERVENTION. BOTH CLL AND MCL INCLUDE 2 MAJOR MOLECULAR SUBTYPES THAT SEEM TO DERIVE FROM ANTIGEN-EXPERIENCED CD5(+) B CELLS THAT RETAIN A NAIVE OR MEMORY-LIKE EPIGENETIC SIGNATURE AND CARRY A VARIABLE LOAD OF IMMUNOGLOBULIN HEAVY-CHAIN VARIABLE REGION SOMATIC MUTATIONS FROM TRULY UNMUTATED TO HIGHLY MUTATED, RESPECTIVELY. THESE 2 SUBTYPES OF TUMORS DIFFER IN THEIR MOLECULAR PATHWAYS, GENOMIC ALTERATIONS, AND CLINICAL BEHAVIOR, BEING MORE AGGRESSIVE IN NAIVE-LIKE THAN MEMORY-LIKE-DERIVED TUMORS IN BOTH CLL AND MCL. THE PATHOGENESIS OF THE 2 ENTITIES INTEGRATES THE RELEVANT INFLUENCE OF B-CELL RECEPTOR SIGNALING, TUMOR CELL MICROENVIRONMENT INTERACTIONS, GENOMIC ALTERATIONS, AND EPIGENOME MODIFICATIONS THAT CONFIGURE THE EVOLUTION OF THE TUMORS AND OFFER NEW POSSIBILITIES FOR THERAPEUTIC INTERVENTION. THIS REVIEW WILL FOCUS ON THE SIMILARITIES AND DIFFERENCES OF THESE 2 TUMORS BASED ON RECENT STUDIES THAT ARE ENHANCING THE UNDERSTANDING OF THEIR PATHOGENESIS AND CREATING SOLID BASES FOR NEW MANAGEMENT STRATEGIES. 2018 7 1102 24 COMBINED CHEMOSENSITIVITY AND CHROMATIN PROFILING PRIORITIZES DRUG COMBINATIONS IN CLL. THE BRUTON TYROSINE KINASE (BTK) INHIBITOR IBRUTINIB HAS SUBSTANTIALLY IMPROVED THERAPEUTIC OPTIONS FOR CHRONIC LYMPHOCYTIC LEUKEMIA (CLL). ALTHOUGH IBRUTINIB IS NOT CURATIVE, IT HAS A PROFOUND EFFECT ON CLL CELLS AND MAY CREATE NEW PHARMACOLOGICALLY EXPLOITABLE VULNERABILITIES. TO IDENTIFY SUCH VULNERABILITIES, WE DEVELOPED A SYSTEMATIC APPROACH THAT COMBINES EPIGENOME PROFILING (CHARTING THE GENE-REGULATORY BASIS OF CELL STATE) WITH SINGLE-CELL CHEMOSENSITIVITY PROFILING (QUANTIFYING CELL-TYPE-SPECIFIC DRUG RESPONSE) AND BIOINFORMATIC DATA INTEGRATION. BY APPLYING OUR METHOD TO A COHORT OF MATCHED PATIENT SAMPLES COLLECTED BEFORE AND DURING IBRUTINIB THERAPY, WE IDENTIFIED CHARACTERISTIC IBRUTINIB-INDUCED CHANGES THAT PROVIDE A STARTING POINT FOR THE RATIONAL DESIGN OF IBRUTINIB COMBINATION THERAPIES. SPECIFICALLY, WE OBSERVED AND VALIDATED PREFERENTIAL SENSITIVITY TO PROTEASOME, PLK1, AND MTOR INHIBITORS DURING IBRUTINIB TREATMENT. MORE GENERALLY, OUR STUDY ESTABLISHES A BROADLY APPLICABLE METHOD FOR INVESTIGATING TREATMENT-SPECIFIC VULNERABILITIES BY INTEGRATING THE COMPLEMENTARY PERSPECTIVES OF EPIGENETIC CELL STATES AND PHENOTYPIC DRUG RESPONSES IN PRIMARY PATIENT SAMPLES. 2019 8 2106 27 EPIGENETIC EVOLUTION AND LINEAGE HISTORIES OF CHRONIC LYMPHOCYTIC LEUKAEMIA. GENETIC AND EPIGENETIC INTRA-TUMORAL HETEROGENEITY COOPERATE TO SHAPE THE EVOLUTIONARY COURSE OF CANCER(1). CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) IS A HIGHLY INFORMATIVE MODEL FOR CANCER EVOLUTION AS IT UNDERGOES SUBSTANTIAL GENETIC DIVERSIFICATION AND EVOLUTION AFTER THERAPY(2,3). THE CLL EPIGENOME IS ALSO AN IMPORTANT DISEASE-DEFINING FEATURE(4,5), AND GROWING POPULATIONS OF CELLS IN CLL DIVERSIFY BY STOCHASTIC CHANGES IN DNA METHYLATION KNOWN AS EPIMUTATIONS(6). HOWEVER, PREVIOUS STUDIES USING BULK SEQUENCING METHODS TO ANALYSE THE PATTERNS OF DNA METHYLATION WERE UNABLE TO DETERMINE WHETHER EPIMUTATIONS AFFECT CLL POPULATIONS HOMOGENEOUSLY. HERE, TO MEASURE THE EPIMUTATION RATE AT SINGLE-CELL RESOLUTION, WE APPLIED MULTIPLEXED SINGLE-CELL REDUCED-REPRESENTATION BISULFITE SEQUENCING TO B CELLS FROM HEALTHY DONORS AND PATIENTS WITH CLL. WE OBSERVED THAT THE COMMON CLONAL ORIGIN OF CLL RESULTS IN A CONSISTENTLY INCREASED EPIMUTATION RATE, WITH LOW VARIABILITY IN THE CELL-TO-CELL EPIMUTATION RATE. BY CONTRAST, VARIABLE EPIMUTATION RATES ACROSS HEALTHY B CELLS REFLECT DIVERSE EVOLUTIONARY AGES ACROSS THE TRAJECTORY OF B CELL DIFFERENTIATION, CONSISTENT WITH EPIMUTATIONS SERVING AS A MOLECULAR CLOCK. HERITABLE EPIMUTATION INFORMATION ALLOWED US TO RECONSTRUCT LINEAGES AT HIGH-RESOLUTION WITH SINGLE-CELL DATA, AND TO APPLY THIS DIRECTLY TO PATIENT SAMPLES. THE CLL LINEAGE TREE SHAPE REVEALED EARLIER BRANCHING AND LONGER BRANCH LENGTHS THAN IN NORMAL B CELLS, REFLECTING RAPID DRIFT AFTER THE INITIAL MALIGNANT TRANSFORMATION AND A GREATER PROLIFERATIVE HISTORY. INTEGRATION OF SINGLE-CELL BISULFITE SEQUENCING ANALYSIS WITH SINGLE-CELL TRANSCRIPTOMES AND GENOTYPING CONFIRMED THAT GENETIC SUBCLONES MAPPED TO DISTINCT CLADES, AS INFERRED SOLELY ON THE BASIS OF EPIMUTATION INFORMATION. FINALLY, TO EXAMINE POTENTIAL LINEAGE BIASES DURING THERAPY, WE PROFILED SERIAL SAMPLES DURING IBRUTINIB-ASSOCIATED LYMPHOCYTOSIS, AND IDENTIFIED CLADES OF CELLS THAT WERE PREFERENTIALLY EXPELLED FROM THE LYMPH NODE AFTER TREATMENT, MARKED BY DISTINCT TRANSCRIPTIONAL PROFILES. THE SINGLE-CELL INTEGRATION OF GENETIC, EPIGENETIC AND TRANSCRIPTIONAL INFORMATION THUS CHARTS THE LINEAGE HISTORY OF CLL AND ITS EVOLUTION WITH THERAPY. 2019 9 5107 42 POLYCYSTIC OVARY SYNDROME: A BRAIN DISORDER CHARACTERIZED BY EATING PROBLEMS ORIGINATING DURING PUBERTY AND ADOLESCENCE. POLYCYSTIC OVARY SYNDROME (PCOS) IS AN ENDOCRINE CONDITION ASSOCIATED WITH REPRODUCTIVE AND PSYCHIATRIC DISORDERS, AND WITH OBESITY. EATING DISORDERS, SUCH AS BULIMIA AND RECURRENT DIETING, ARE ALSO LINKED TO PCOS. THEY CAN LEAD TO THE EPIGENETIC DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-GONADAL (HPG) AXIS, THEREBY IMPACTING ON OVARIAN FOLLICULOGENESIS. WE POSTULATE THAT PCOS IS INDUCED BY PSYCHOLOGICAL DISTRESS AND EPISODES OF OVEREATING AND/OR DIETING DURING PUBERTY AND ADOLESCENCE, WHEN BODY DISSATISFACTION AND EMOTIONAL DISTRESS ARE OFTEN PRESENT. WE PROPOSE THAT UPREGULATED ACTIVATION OF THE CENTRAL HPG AXIS DURING THIS PERIOD CAN BE EPIGENETICALLY ALTERED BY PSYCHOLOGICAL STRESSORS AND BY BULIMIA/RECURRENT DIETING, WHICH ARE COMMON DURING ADOLESCENCE AND WHICH CAN LEAD TO PCOS. THIS HYPOTHESIS IS BASED ON EVENTS THAT OCCUR DURING A LARGELY NEGLECTED STAGE OF FEMALE REPRODUCTIVE DEVELOPMENT. TO DATE, MOST RESEARCH INTO THE ORIGINS OF PCOS HAS FOCUSED ON THE PRENATAL INDUCTION OF THIS DISORDER, PARTICULARLY IN UTERO ANDROGENIZATION AND THE ROLE OF ANTI-MULLERIAN HORMONE. ESTABLISHING CAUSALITY IN OUR PERIPUBERTAL MODEL REQUIRES PROSPECTIVE COHORT STUDIES FROM INFANCY. MECHANISTIC STUDIES SHOULD CONSIDER THE ROLE OF THE GUT MICROBIOTA IN ADDITION TO THE EPIGENETIC REGULATION OF (NEURO) HORMONES. FINALLY, CLINICIANS SHOULD CONSIDER THE IMPORTANCE OF UNDERLYING CHRONIC PSYCHOLOGICAL DISTRESS AND EATING DISORDERS IN PCOS. 2020 10 6894 28 [SOCIAL INEQUALITY AND MENTAL HEALTH]. SOCIAL INEQUALITY REFERS TO THE INEQUITABLE DISTRIBUTION OF SOCIAL PROSPERITY INCLUDING THE RESOURCE OF HEALTH. THE RELATIONSHIP BETWEEN SOCIAL INEQUALITY AND MENTAL HEALTH CAN BE ESTABLISHED BY MEANS OF INDICATORS OF SOCIAL INEQUALITY THROUGHOUT ALL AGE GROUPS IN GERMANY. THERE ARE SOCIAL GRADIENTS OF MENTAL HEALTH ON THE POPULATION LEVEL, I.E. THE LINEAR RELATIONSHIP BETWEEN SOCIAL CLASSES OR STATUS AND STATE OF HEALTH. FUNDAMENTAL DETERMINANTS OF HEALTH DISPARITY ARE CULTURAL, SOCIAL, POLITICAL, AND GEOGRAPHICAL CONDITIONS, WHICH INTERACT WITH THE GENETIC MAKE-UP AND EPIGENETIC PROCESSES. THESE DETERMINANTS ALSO INFLUENCE THE MANAGEMENT OF DEVELOPMENTAL TASKS DURING THE LIFE COURSE AND ARE OF UTMOST IMPORTANCE FOR THE DEVELOPMENT OF MENTAL DISORDERS. THE MALADAPTATION TO CHRONIC STRESS IS AT THE CORE OF HEALTH DISPARITY. INTERVENTIONS AT THE INDIVIDUAL BEHAVIORAL LEVEL SHOULD COMPRISE THE DEVELOPMENT OF STRESS MANAGEMENT AND COPING STRATEGIES. 2019 11 1754 40 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 12 3926 36 LITERATURE REVIEW AND METHODOLOGICAL CONSIDERATIONS FOR UNDERSTANDING CIRCULATING RISK BIOMARKERS FOLLOWING TRAUMA EXPOSURE. EXPOSURE TO TRAUMATIC EVENTS IS COMMON. WHILE MANY INDIVIDUALS RECOVER FOLLOWING TRAUMA EXPOSURE, A SUBSTANTIAL SUBSET DEVELOP ADVERSE POSTTRAUMATIC NEUROPSYCHIATRIC SEQUELAE (APNS) SUCH AS POSTTRAUMATIC STRESS, MAJOR DEPRESSION, AND REGIONAL OR WIDESPREAD CHRONIC MUSCULOSKELETAL PAIN. APNS CAUSE SUBSTANTIAL BURDEN TO THE INDIVIDUAL AND TO SOCIETY, CAUSING FUNCTIONAL IMPAIRMENT AND PHYSICAL DISABILITY, RISK FOR SUICIDE, LOST WORKDAYS, AND INCREASED HEALTH CARE COSTS. CONTEMPORARY TREATMENT IS LIMITED BY AN INABILITY TO IDENTIFY INDIVIDUALS AT HIGH RISK OF APNS IN THE IMMEDIATE AFTERMATH OF TRAUMA, AND AN INABILITY TO IDENTIFY OPTIMAL TREATMENTS FOR INDIVIDUAL PATIENTS. OUR PURPOSE IS TO PROVIDE A COMPREHENSIVE REVIEW DESCRIBING CANDIDATE BLOOD-BASED BIOMARKERS THAT MAY HELP TO IDENTIFY THOSE AT HIGH RISK OF APNS AND/OR GUIDE INDIVIDUAL INTERVENTION DECISION-MAKING. SUCH BLOOD-BASED BIOMARKERS INCLUDE CIRCULATING BIOLOGICAL FACTORS SUCH AS HORMONES, PROTEINS, IMMUNE MOLECULES, NEUROPEPTIDES, NEUROTRANSMITTERS, MRNA, AND NONCODING RNA EXPRESSION SIGNATURES, WHILE WE DO NOT REVIEW GENETIC AND EPIGENETIC BIOMARKERS DUE TO OTHER RECENT REVIEWS OF THIS TOPIC. THE CURRENT STATE OF THE LITERATURE ON CIRCULATING RISK BIOMARKERS OF APNS IS SUMMARIZED, AND KEY CONSIDERATIONS AND CHALLENGES FOR THEIR DISCOVERY AND TRANSLATION ARE DISCUSSED. WE ALSO DESCRIBE THE AURORA STUDY, A SPECIFIC EXAMPLE OF CURRENT SCIENTIFIC EFFORTS TO IDENTIFY SUCH CIRCULATING RISK BIOMARKERS AND THE LARGEST STUDY TO DATE FOCUSED ON IDENTIFYING RISK AND PROGNOSTIC FACTORS IN THE AFTERMATH OF TRAUMA EXPOSURE. 2020 13 5827 27 STRESS, BURNOUT AND DEPRESSION: A SYSTEMATIC REVIEW ON DNA METHYLATION MECHANISMS. DESPITE THAT BURNOUT PRESENTS A SERIOUS BURDEN FOR MODERN SOCIETY, THERE ARE NO DIAGNOSTIC CRITERIA. ADDITIONAL DIFFICULTY IS THE DIFFERENTIAL DIAGNOSIS WITH DEPRESSION. CONSEQUENTLY, THERE IS A NEED TO DISPOSE OF A BURNOUT BIOMARKER. EPIGENETIC STUDIES SUGGEST THAT DNA METHYLATION IS A POSSIBLE MEDIATOR LINKING INDIVIDUAL RESPONSE TO STRESS AND PSYCHOPATHOLOGY AND COULD BE CONSIDERED AS A POTENTIAL BIOMARKER OF STRESS-RELATED MENTAL DISORDERS. THUS, THE AIM OF THIS REVIEW IS TO PROVIDE AN OVERVIEW OF DNA METHYLATION MECHANISMS IN STRESS, BURNOUT AND DEPRESSION. IN ADDITION TO STATE-OF-THE-ART OVERVIEW, THE GOAL OF THIS REVIEW IS TO PROVIDE A SCIENTIFIC BASE FOR BURNOUT BIOMARKER RESEARCH. WE PERFORMED A SYSTEMATIC LITERATURE SEARCH AND IDENTIFIED 25 PERTINENT ARTICLES. AMONG THESE, 15 FOCUSED ON DEPRESSION, 7 ON CHRONIC STRESS AND ONLY 3 ON WORK STRESS/BURNOUT. THREE EPIGENOME-WIDE STUDIES WERE IDENTIFIED AND THE MAJORITY OF STUDIES USED THE CANDIDATE-GENE APPROACH, ASSESSING 12 DIFFERENT GENES. THE GLUCOCORTICOID RECEPTOR GENE (NR3C1) DISPLAYED DIFFERENT METHYLATION PATTERNS IN CHRONIC STRESS AND DEPRESSION. THE SEROTONIN TRANSPORTER GENE (SLC6A4) METHYLATION WAS SIMILARLY AFFECTED IN STRESS, DEPRESSION AND BURNOUT. WORK-RELATED STRESS AND DEPRESSIVE SYMPTOMS WERE ASSOCIATED WITH DIFFERENT METHYLATION PATTERNS OF THE BRAIN DERIVED NEUROTROPHIC FACTOR GENE (BDNF) IN THE SAME HUMAN SAMPLE. THE TYROSINE HYDROXYLASE (TH) METHYLATION WAS CORRELATED WITH WORK STRESS IN A SINGLE STUDY. ADDITIONAL, THOROUGHLY DESIGNED LONGITUDINAL STUDIES ARE NECESSARY FOR REVEALING THE CAUSE-EFFECT RELATIONSHIP OF WORK STRESS, EPIGENETICS AND BURNOUT, INCLUDING ITS OVERLAP WITH DEPRESSION. 2017 14 675 29 BRAIN AGE AND OTHER BODILY 'AGES': IMPLICATIONS FOR NEUROPSYCHIATRY. AS OUR BRAINS AGE, WE TEND TO EXPERIENCE COGNITIVE DECLINE AND ARE AT GREATER RISK OF NEURODEGENERATIVE DISEASE AND DEMENTIA. SYMPTOMS OF CHRONIC NEUROPSYCHIATRIC DISEASES ARE ALSO EXACERBATED DURING AGEING. HOWEVER, THE AGEING PROCESS DOES NOT AFFECT PEOPLE UNIFORMLY; NOR, IN FACT, DOES THE AGEING PROCESS APPEAR TO BE UNIFORM EVEN WITHIN AN INDIVIDUAL. HERE, WE OUTLINE RECENT NEUROIMAGING RESEARCH INTO BRAIN AGEING AND THE USE OF OTHER BODILY AGEING BIOMARKERS, INCLUDING TELOMERE LENGTH, THE EPIGENETIC CLOCK, AND GRIP STRENGTH. SOME OF THESE TECHNIQUES, USING STATISTICAL APPROACHES, HAVE THE ABILITY TO PREDICT CHRONOLOGICAL AGE IN HEALTHY PEOPLE. MOREOVER, THEY ARE NOW BEING APPLIED TO NEUROLOGICAL AND PSYCHIATRIC DISEASE GROUPS TO PROVIDE INSIGHTS INTO HOW THESE DISEASES INTERACT WITH THE AGEING PROCESS AND TO DELIVER INDIVIDUALISED PREDICTIONS ABOUT FUTURE BRAIN AND BODY HEALTH. WE DISCUSS THE IMPORTANCE OF INTEGRATING DIFFERENT TYPES OF BIOLOGICAL MEASUREMENTS, FROM BOTH THE BRAIN AND THE REST OF THE BODY, TO BUILD MORE COMPREHENSIVE MODELS OF THE BIOLOGICAL AGEING PROCESS. FINALLY, WE PROPOSE SEVEN STEPS FOR THE FIELD OF BRAIN-AGEING RESEARCH TO TAKE IN COMING YEARS. THIS WILL HELP US REACH THE LONG-TERM GOAL OF DEVELOPING CLINICALLY APPLICABLE STATISTICAL MODELS OF BIOLOGICAL PROCESSES TO MEASURE, TRACK AND PREDICT BRAIN AND BODY HEALTH IN AGEING AND DISEASE. 2019 15 5644 23 SEX AND THE MIGRAINE BRAIN. THE BRAIN RESPONDS DIFFERENTLY TO ENVIRONMENTAL AND INTERNAL SIGNALS THAT RELATE TO THE STAGE OF DEVELOPMENT OF NEURAL SYSTEMS. WHILE GENETIC AND EPIGENETIC FACTORS CONTRIBUTE TO A PREMORBID STATE, HORMONAL FLUCTUATIONS IN WOMEN MAY ALTER THE SET POINT OF MIGRAINE. THE CYCLIC SURGES OF GONADAL HORMONES MAY DIRECTLY ALTER NEURONAL, GLIAL AND ASTROCYTE FUNCTION THROUGHOUT THE BRAIN. ESTROGEN IS MAINLY EXCITATORY AND PROGESTERONE INHIBITORY ON BRAIN NEURONAL SYSTEMS. THESE CHANGES CONTRIBUTE TO THE ALLOSTATIC LOAD OF THE MIGRAINE CONDITION THAT MOST NOTABLY STARTS AT PUBERTY IN GIRLS. 2014 16 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 17 1737 36 EARLY DETECTION OF ACCELERATED AGING AND CELLULAR DECLINE (AACD): A CONSENSUS STATEMENT. THE CELLULAR HALLMARKS OF ACCELERATED AGING AND THEIR CLINICAL EXPRESSION MAY BE GROUPED USING THE TERMS 'ACCELERATED AGING AND CELLULAR DECLINE' (AACD) AND/OR 'AGE-ASSOCIATED CELLULAR DECLINE'. THIS CONSTRUCT IS DESIGNED TO CAPTURE THE BIOLOGICAL BACKGROUND PREDISPOSING THE DEVELOPMENT OF AGE-RELATED CONDITIONS. BY CLASSIFYING RISK FACTORS, EARLY INDICATORS, AND CLINICAL DIFFERENTIATORS OF AACD THROUGH EXPERT CONSENSUS, THIS STUDY AIMED TO IDENTIFY THE SIGNS, SYMPTOMS, AND MARKERS INDICATIVE OF AACD. IN DOING SO, THIS WORK PAVES THE WAY FOR FUTURE IMPLEMENTATION OF THE AACD CONCEPT IN THE CLINICAL AND RESEARCH SETTINGS. AN INTERDISCIPLINARY PANEL OF EXPERTS WITH CLINICAL AND RESEARCH EXPERTISE WAS SELECTED TO PARTICIPATE IN A VIRTUAL WORKSHOP TO DISCUSS AACD. A MODIFIED NOMINAL GROUP TECHNIQUE WAS USED TO ESTABLISH CONSENSUS AMONG THE GROUP. AN EXTENDED GROUP OF INTERNATIONAL EXPERTS CRITICALLY REVIEWED AN EARLY DRAFT OF THE MANUSCRIPT, AND THEIR FEEDBACK WAS THEN INCORPORATED INTO THE MODEL. EXPERTS IDENTIFIED 13 FACTORS PREDISPOSING TO OR CLINICALLY MANIFESTING AACD. AMONG THESE, CHRONIC DISEASES, OBESITY, AND UNFAVORABLE GENETIC BACKGROUND WERE CONSIDERED AS THE MOST IMPORTANT. THERE WAS A CONSENSUS THAT A GRADUAL AND NONSPECIFIC DEVELOPMENT OFTEN CHARACTERIZES AACD, MAKING ITS CLINICAL DETECTION POTENTIALLY CHALLENGING. IN ADDITION, SIGNS AND SYMPTOMS MIGHT HAVE MULTIFACTORIAL CAUSES AND OVERLAPPING ORIGINS, SUCH AS GENETIC AND EPIGENETIC PREDISPOSITIONS. AS A RESULT, AN INITIAL CHECKLIST WAS OUTLINED, LISTING CLINICAL FACTORS OF SPECIAL RELEVANCE (E.G., FATIGUE, LOW QUALITY OF SLEEP, AND LOW MOOD) TO REPRESENT EARLY MANIFESTATIONS OF THE ORGANISM'S EXHAUSTION, WHICH ARE ALSO FREQUENTLY NEGLECTED IN THE CLINICAL SETTING. DIFFERENTIATING AACD FROM OTHER CONDITIONS IS ESSENTIAL. THE USE OF A COMBINATION OF BIOMARKERS WAS PROPOSED AS A VIABLE METHOD IN A TWO-STEP PROCESS OF DIFFERENTIATION: 1) IDENTIFICATION OF EARLY AACD CLINICAL INDICATORS, FOLLOWED BY 2) SYMPTOM AND BIOMARKER CONFIRMATION WITH A FOCUS ON SYSTEM DOMAINS (TO BE POTENTIALLY TARGETED BY FUTURE SPECIFIC INTERVENTIONS). ALTHOUGH THE AACD CONSTRUCT IS NOT YET READY FOR ROUTINE USE IN CLINICAL PRACTICE, ITS OPERATIONALIZATION MAY SUPPORT THE EARLY IDENTIFICATION OF AGE-RELATED CONDITIONS (WHEN THIS MIGHT STILL BE AMENABLE TO REVERSION) AND ALSO ENCOURAGE PREVENTATIVE INTERVENTIONS. FURTHER INVESTIGATION IS NEEDED TO ESTABLISH SPECIFIC BIOMARKERS THAT CONFIRM INDEPENDENT RISK FACTORS FOR AACD AND PROVIDE A MORE DEFINITIVE STRUCTURE TO THE CONCEPT OF AACD (AND AGE-ASSOCIATED CELLULAR DECLINE). 2021 18 1154 24 CONSERVED DNA METHYLATION PATTERNS IN HEALTHY BLOOD CELLS AND EXTENSIVE CHANGES IN LEUKEMIA MEASURED BY A NEW QUANTITATIVE TECHNIQUE. GENOME WIDE ANALYSIS OF DNA METHYLATION PROVIDES IMPORTANT INFORMATION IN A VARIETY OF DISEASES, INCLUDING CANCER. HERE, WE DESCRIBE A SIMPLE METHOD, DIGITAL RESTRICTION ENZYME ANALYSIS OF METHYLATION (DREAM), BASED ON NEXT GENERATION SEQUENCING ANALYSIS OF METHYLATION-SPECIFIC SIGNATURES CREATED BY SEQUENTIAL DIGESTION OF GENOMIC DNA WITH SMAI AND XMAI ENZYMES. DREAM PROVIDES INFORMATION ON 150,000 UNIQUE CPG SITES, OF WHICH 39,000 ARE IN CPG ISLANDS AND 30,000 ARE AT TRANSCRIPTION START SITES OF 13,000 REFSEQ GENES. WE ANALYZED DNA METHYLATION IN HEALTHY WHITE BLOOD CELLS AND FOUND METHYLATION PATTERNS TO BE REMARKABLY UNIFORM. INTER INDIVIDUAL DIFFERENCES > 30% WERE OBSERVED ONLY AT 227 OF 28,331 (0.8%) OF AUTOSOMAL CPG SITES. SIMILARLY, > 30% DIFFERENCES WERE OBSERVED AT ONLY 59 SITES WHEN WE COMPARING THE CORD AND ADULT BLOOD. THESE CONSERVED METHYLATION PATTERNS CONTRASTED WITH EXTENSIVE CHANGES AFFECTING 18-40% OF CPG SITES IN A PATIENT WITH ACUTE MYELOID LEUKEMIA AND IN TWO LEUKEMIA CELL LINES. THE METHOD IS COST EFFECTIVE, QUANTITATIVE (R ( 2) = 0.93 WHEN COMPARED WITH BISULFITE PYROSEQUENCING) AND REPRODUCIBLE (R ( 2) = 0.997). USING 100-FOLD COVERAGE, DREAM CAN DETECT DIFFERENCES IN METHYLATION GREATER THAN 10% OR 30% WITH A FALSE POSITIVE RATE BELOW 0.05 OR 0.001, RESPECTIVELY. DREAM CAN BE USEFUL IN QUANTIFYING EPIGENETIC EFFECTS OF ENVIRONMENT AND NUTRITION, CORRELATING DEVELOPMENTAL EPIGENETIC VARIATION WITH PHENOTYPES, UNDERSTANDING EPIGENETICS OF CANCER AND CHRONIC DISEASES, MEASURING THE EFFECTS OF DRUGS ON DNA METHYLATION OR DERIVING NEW BIOLOGICAL INSIGHTS INTO MAMMALIAN GENOMES. 2012 19 3001 38 GENETIC, EPIGENETIC AND ENVIRONMENTAL IMPACT ON SEX DIFFERENCES IN SOCIAL BEHAVIOR. THE FIELD OF BEHAVIORAL NEUROENDOCRINOLOGY HAS GENERATED THOUSANDS OF STUDIES THAT INDICATE DIFFERENCES IN BRAIN STRUCTURE AND REACTIVITY TO GONADAL STEROIDS THAT PRODUCE SEX-SPECIFIC PATTERNS OF SOCIAL BEHAVIOR. HOWEVER, RAPIDLY EMERGING EVIDENCE SHOWS THAT GENETIC POLYMORPHISMS AND RESULTING DIFFERENCES IN THE EXPRESSION OF NEUROACTIVE PEPTIDES AND RECEPTORS AS WELL AS EARLY-LIFE EXPERIENCE AND EPIGENETIC CHANGES ARE IMPORTANT MODIFIERS OF SOCIAL BEHAVIOR. FURTHERMORE, DUE TO ITS INHERENT COMPLEXITY, THE NEUROCHEMICAL MECHANISMS UNDERLYING SEX DIFFERENCES IN SOCIAL BEHAVIOR ARE USUALLY STUDIED IN A TIGHTLY REGULATED LABORATORY SETTING RATHER THAN IN COMPLEX ENVIRONMENTS. IMPORTANTLY, SPECIFIC HORMONES MAY ELICIT A RANGE OF DIFFERENT BEHAVIORS DEPENDING ON THE CUES PRESENT IN THESE ENVIRONMENTS. FOR EXAMPLE, INDIVIDUALS EXPOSED TO A PSYCHOSOCIAL STRESSOR MAY RESPOND DIFFERENTLY TO THE EFFECTS OF A GONADAL STEROID THAN THOSE NOT EXPOSED TO CHRONIC STRESS. THE OBJECTIVE OF THIS REVIEW IS NOT TO RE-EXAMINE THE ACTIVATIONAL EFFECTS OF HORMONES ON SEX DIFFERENCES IN SOCIAL BEHAVIOR BUT RATHER TO CONSIDER HOW GENETIC AND ENVIRONMENTAL FACTORS MODIFY THE EFFECTS OF HORMONES ON BEHAVIOR. WE WILL FOCUS ON ESTROGEN AND ITS RECEPTORS BUT CONSIDERATION IS ALSO GIVEN TO THE ROLE OF ANDROGENS. FURTHERMORE, WE HAVE LIMITED OUR DISCUSSIONS TO THE IMPORTANCE OF OXYTOCIN AND VASOPRESSIN AS TARGETS OF GONADAL STEROIDS AND HOW THESE EFFECTS ARE MODIFIED BY GENETIC AND EXPERIENTIAL SITUATIONS. TAKEN TOGETHER, THE DATA CLEARLY UNDERSCORE THE NEED TO EXPAND RESEARCH INITIATIVES TO CONSIDER GENE-ENVIRONMENT INTERACTIONS FOR BETTER UNDERSTANDING OF THE NEUROBIOLOGY OF SEX DIFFERENCES IN SOCIAL BEHAVIOR. 2009 20 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