1 5754 101 SOCIAL PSYCHOGENIC STRESS PROMOTES THE DEVELOPMENT OF ENDOMETRIOSIS IN MOUSE. EXPOSURE TO CHRONIC STRESS BEFORE AND WELL AFTER THE INDUCTION OF ENDOMETRIOSIS IS REPORTED TO INCREASE LESION SIZES IN RATS, BUT IT IS UNCLEAR WHETHER STRESS, EXPOSED SHORTLY AFTER THE INDUCTION OF ENDOMETRIOSIS, WOULD ALSO PROMOTE THE DEVELOPMENT OF ENDOMETRIOSIS, NOR IS IT CLEAR WHAT THE UNDERLYING POSSIBLE MOLECULAR MECHANISM IS. THIS STUDY WAS UNDERTAKEN TO TEST THE HYPOTHESIS THAT CHRONIC STRESS CAN PROMOTE THE DEVELOPMENT OF ENDOMETRIOSIS. A PROSPECTIVE RANDOMIZED MOUSE EXPERIMENT WAS CONDUCTED THAT SUBJECTED MICE WITH INDUCED ENDOMETRIOSIS TO PREDATOR STRESS. IN ADDITION, A CROSS-SECTIONAL IMMUNOHISTOCHEMISTRY STUDY WAS PERFORMED IN ECTOPIC AND EUTOPIC ENDOMETRIAL TISSUE SAMPLES FROM AGE- AND ROUGHLY MENSTRUAL PHASE-MATCHED WOMEN WITH OVARIAN ENDOMETRIOMAS. IT WAS FOUND THAT THE CHRONIC PSYCHOGENIC STRESS INDUCED EPIGENETIC CHANGES IN THE HIPPOCAMPUS IN MOUSE INDEPENDENT OF ENDOMETRIOSIS. IT WAS ALSO FOUND THAT CHRONIC PSYCHOGENIC STRESS INDUCED EPIGENETIC CHANGES IN THE HIPPOCAMPUS OF MICE WITH ENDOMETRIOSIS, AND SEEMINGLY ACTIVATED THE ADRENERGIC SIGNALLING IN ECTOPIC ENDOMETRIUM, RESULTING IN INCREASED ANGIOGENESIS AND ACCELERATED GROWTH OF ENDOMETRIOTIC LESIONS. THUS, CHRONIC PSYCHOGENIC STRESS PROMOTES ENDOMETRIOSIS DEVELOPMENT, RAISING THE POSSIBILITY THAT THE USE OF ANTI-DEPRESSANTS IN CASES OF PROLONGED AND INTENSE STRESS MIGHT FORESTALL THE NEGATIVE IMPACT OF STRESS ON THE DEVELOPMENT OF ENDOMETRIOSIS. 2017 2 1202 23 COULD DNA HYDROXYMETHYLATION BE CRUCIAL IN INFLUENCING STEROID HORMONE SIGNALING IN ENDOMETRIAL BIOLOGY AND ENDOMETRIOSIS? ENDOMETRIOSIS AFFECTS 10% OF REPRODUCTIVE-AGED WOMEN. IT IS CHARACTERIZED BY THE GROWTH OF THE ENDOMETRIUM, OUTSIDE THE UTERUS AND IS ASSOCIATED WITH INFERTILITY AND CHRONIC ABDOMINAL PAIN. LACK OF NONINVASIVE DIAGNOSTIC TOOLS AND EARLY SCREENING TESTS RESULTS IN DELAYED TREATMENT AND SUBSEQUENTLY INCREASED DISEASE SEVERITY. ENDOMETRIOSIS IS A DISEASE ASSOCIATED WITH A DEREGULATED HORMONAL RESPONSE, THEREFORE, UNDERSTANDING THE MOLECULAR MECHANISMS THAT GOVERN THIS HORMONAL INTERPLAY IS OF PARAMOUNT IMPORTANCE. DNA METHYLATION IS AN EPIGENETIC MARK THAT REGULATES GENE EXPRESSION AND IS OFTEN ASSOCIATED WITH GENES THAT CODE FOR STEROID RECEPTORS AND ENZYMES ASSOCIATED WITH ESTROGEN SYNTHESIS AND METABOLISM IN ENDOMETRIOSIS. DNA HYDROXYMETHYLATION, WHICH IS STRUCTURALLY SIMILAR TO METHYLATION BUT FUNCTIONALLY DIFFERENT, IS A BIOLOGICALLY CRITICAL MECHANISM THAT IS ALSO KNOWN TO REGULATE GENE EXPRESSION. TEN ELEVEN TRANSLOCATION (TET) PROTEINS MEDIATE HYDROXYMETHYLATION. HOWEVER, THE ROLE OF DNA HYDROXYMETHYLATION OR TETS IN THE ENDOMETRIUM REMAINS RELATIVELY UNEXPLORED. CURRENTLY, THE "GOLD STANDARD" TECHNIQUE USED TO STUDY METHYLATION PATTERNS IS BISULFITE GENOMIC SEQUENCING. THIS TECHNIQUE ALSO DETECTS HYDROXYMETHYLATION BUT FAILS TO DISTINGUISH BETWEEN THE TWO, THEREBY LIMITING OUR UNDERSTANDING OF THESE TWO PROCESSES. THE PRESENCE OF TETS IN THE MALE AND FEMALE REPRODUCTIVE TRACT AND ITS CONTRIBUTION TO ENDOMETRIAL CANCER MAKES IT AN IMPORTANT FACTOR TO STUDY IN ENDOMETRIOSIS. THIS REVIEW SUMMARIZES THE ROLE OF DNA METHYLATION IN ABERRANT STEROID HORMONE SIGNALING AND HYPOTHESIZES THAT HYDROXYMETHYLATION COULD BE A FACTOR INFLUENCING HORMONAL INSTABILITY SEEN IN ENDOMETRIOSIS. 2020 3 3003 33 GENETIC, EPIGENETIC AND STEM CELL ALTERATIONS IN ENDOMETRIOSIS: NEW INSIGHTS AND POTENTIAL THERAPEUTIC PERSPECTIVES. HUMAN ENDOMETRIUM IS A HIGHLY DYNAMIC TISSUE, UNDERGOING PERIODIC GROWTH AND REGRESSION AT EACH MENSTRUAL CYCLE. ENDOMETRIOSIS IS A FREQUENT CHRONIC PATHOLOGICAL STATUS CHARACTERIZED BY ENDOMETRIAL TISSUE WITH AN ECTOPIC LOCALIZATION, CAUSING PELVIC PAIN AND INFERTILITY AND A VARIABLE CLINICAL PRESENTATION. IN ADDITION, THERE IS WELL-ESTABLISHED EVIDENCE THAT, ALTHOUGH ENDOMETRIOSIS IS CONSIDERED BENIGN, IT IS ASSOCIATED WITH AN INCREASED RISK OF MALIGNANT TRANSFORMATION IN APPROXIMATELY 1.0% OF AFFECTED WOMEN, WITH THE INVOLVEMENT OF MULTIPLE PATHWAYS OF DEVELOPMENT. INCREASING EVIDENCE SUPPORTS A KEY CONTRIBUTION OF DIFFERENT STEM/PROGENITOR CELL POPULATIONS NOT ONLY IN THE CYCLIC REGENERATION OF EUTOPIC ENDOMETRIUM, BUT ALSO IN THE PATHOGENESIS OF AT LEAST SOME TYPES OF ENDOMETRIOSIS. EVIDENCE HAS ARISEN FROM EXPERIMENTS IN ANIMAL MODELS OF DISEASE THROUGH DIFFERENT KINDS OF ASSAYS (INCLUDING CLONOGENICITY, THE LABEL-RETAINING CELL APPROACH, THE ANALYSIS OF UNDIFFERENTIATION MARKERS), AS WELL AS FROM DESCRIPTIVE STUDIES ON ECTOPIC AND EUTOPIC TISSUE SAMPLES HARVESTED FROM AFFECTED WOMEN. CHANGES IN STEM CELL POPULATIONS IN ENDOMETRIOTIC LESIONS ARE ASSOCIATED WITH GENETIC AND EPIGENETIC ALTERATIONS, INCLUDING IMBALANCE OF MIRNA EXPRESSION, HISTONE AND DNA MODIFICATIONS AND CHROMOSOMAL ABERRATIONS. THE PRESENT SHORT REVIEW MAINLY SUMMARIZES THE LATEST OBSERVATIONS CONTRIBUTING TO THE CURRENT KNOWLEDGE REGARDING THE PRESENCE AND THE POTENTIAL CONTRIBUTION OF STEM/PROGENITOR CELLS IN EUTOPIC ENDOMETRIUM AND THE AETIOLOGY OF ENDOMETRIOSIS, TOGETHER WITH A REPORT OF THE MOST RECENTLY IDENTIFIED GENETIC AND EPIGENETIC ALTERATIONS IN ENDOMETRIOSIS. WE ALSO DESCRIBE THE POTENTIAL ADVANTAGES OF SINGLE CELL MOLECULAR PROFILING IN ENDOMETRIUM AND IN ENDOMETRIOTIC LESIONS. ALL THESE DATA CAN HAVE CLINICAL IMPLICATIONS AND PROVIDE A BASIS FOR NEW POTENTIAL THERAPEUTIC APPLICATIONS. 2014 4 5892 24 SYSTEMS GENETICS VIEW OF ENDOMETRIOSIS: A COMMON COMPLEX DISORDER. ENDOMETRIOSIS IS A CONDITION IN WHICH CELLS DERIVED FROM THE ENDOMETRIUM GROW OUTSIDE THE UTERUS, E.G. IN THE PERITONEUM (EXTERNAL GENITAL ENDOMETRIOSIS). AS THESE CELLS ARE UNDER THE INFLUENCE OF FEMALE HORMONES, MAJOR SYMPTOMS OF ENDOMETRIOSIS ARE PAIN, ESPECIALLY DURING THE CYCLE, AND INFERTILITY. NUMEROUS HYPOTHESES FOR THE FORMATION OF ENDOMETRIOSIS CAN BE FOUND IN THE LITERATURE, BUT THERE IS GROWING EVIDENCE OF SERIOUS GENETIC CONTRIBUTIONS TO ENDOMETRIOSIS SUSCEPTIBILITY. THE INVOLVEMENT OF GENES, STEROID HORMONE METABOLISM, IMMUNOLOGICAL REACTIONS, RECEPTOR FORMATION, INFLAMMATION, PROLIFERATION, APOPTOSIS, INTERCELLULAR ADHESION, CELL INVASION AND ANGIOGENESIS AS WELL AS GENES REGULATING THE ACTIVITY OF AFOREMENTIONED ENZYMES HAVE BEEN SUGGESTED. SOME MORE RECENTLY SUGGESTED CANDIDATE GENES PICKED UP IN GENOME-WIDE ASSOCIATION STUDIES ARE INVOLVED IN ONCOGENESIS, METAPLASIA OF ENDOMETRIUM CELLS AND PATHWAYS OF EMBRYONIC DEVELOPMENT OF THE FEMALE REPRODUCTIVE SYSTEM. HOWEVER, GENE MUTATIONS PROVEN TO BE CAUSATIVE FOR ENDOMETRIOSIS HAVE NOT BEEN IDENTIFIED SO FAR, EVEN THOUGH THE ABNORMAL EXPRESSION OF CANDIDATE GENES FOR ENDOMETRIOSIS COULD BE PROVOKED BY DIFFERENT EPIGENETIC MODIFICATIONS INCLUDING DNA METHYLATION, HETEROCHROMATIZATION OR INTRODUCTION OF REGULATORY MIRNA. WE HYPOTHESIZE THAT ENDOMETRIOSIS IS INDUCED BY A COMBINATION OF ABNORMAL GENETIC AND/OR EPIGENETIC MUTATIONS: THE LATTER PAVE THE WAY FOR PATHOLOGICAL CHANGES WHICH BECOME IRREVERSIBLE, AND ACCORDING TO THE "EPIGENETIC LANDSCAPE" THEORY, THIS PROCEEDS TO THE TYPICAL CLINICAL MANIFESTATIONS. TWO STAGES IN THE ENDOMETRIOSIS PATHWAY ARE SUGGESTED: (1) INDUCTION OF PRIMARY ENDOMETRIAL CELLS TOWARD ENDOMETRIOSIS, AND (2) IMPLANTATION AND PROGRESSION OF THESE CELLS INTO ENDOMETRIOSIS LESIONS. THE MODEL FAVORS ENDOMETRIOSIS AS AN OUTGROWTH OF PRIMARY CELLS DIFFERENT IN THEIR ORIGIN, CANALIZATION OF PATHOLOGICAL PROCESSES, MANIFESTATION DIVERSITY PROVOKED BY UNIQUE GENETIC BACKGROUND AND EPIGENETIC INFLUENCES, WHICH RESULT IN MANY DIFFERENT CLINICAL FORMS OF THE DISEASE. 2015 5 3005 21 GENETIC, EPIGENETIC, AND STEROIDOGENIC MODULATION MECHANISMS IN ENDOMETRIOSIS. ENDOMETRIOSIS IS A CHRONIC GYNECOLOGICAL DISEASE, AFFECTING UP TO 10% OF REPRODUCTIVE-AGE WOMEN. THE EXACT CAUSE OF THE DISEASE IS UNKNOWN; HOWEVER, IT IS A HERITABLE CONDITION AFFECTED BY MULTIPLE GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS. PREVIOUS STUDIES REPORTED VARIATIONS IN THE EPIGENETIC PATTERNS OF NUMEROUS GENES KNOWN TO BE INVOLVED IN THE ABERRANT MODULATION OF CELL CYCLE STEROIDOGENESIS, ABNORMAL HORMONAL, IMMUNE AND INFLAMMATORY STATUS IN ENDOMETRIOSIS, APOPTOSIS, ADHESION, ANGIOGENESIS, PROLIFERATION, IMMUNE AND INFLAMMATORY PROCESSES, RESPONSE TO HYPOXIA, STEROIDOGENIC PATHWAY AND HORMONE SIGNALING ARE INVOLVED IN THE PATHOGENESIS OF ENDOMETRIOSIS. ACCUMULATING EVIDENCE SUGGEST THAT VARIOUS EPIGENETIC ABERRATIONS MAY CONTRIBUTE TO THE PATHOGENESIS OF ENDOMETRIOSIS. AMONG THEM, DNA METHYLTRANSFERASES, HISTONE DEACETYLATORS, AND NON-CODING MICRORNAS DEMONSTRATE DIFFERENTIAL EXPRESSION WITHIN ENDOMETRIOTIC LESIONS AND IN THE ENDOMETRIUM OF PATIENTS WITH ENDOMETRIOSIS. IT HAS BEEN INDICATED THAT THE IDENTIFICATION OF EPIGENETIC DIFFERENCES WITHIN THE DNA OR HISTONE PROTEINS MAY CONTRIBUTE TO THE DISCOVERY OF A USEFUL PROGNOSTIC BIOMARKER, WHICH COULD AID IN THE FUTURE EARLIER DETECTION, TIMELY DIAGNOSIS, AND INITIATION OF A NEW APPROACH TO THE TREATMENT OF ENDOMETRIOSIS, AS WELL AS INFORM US ABOUT THE EFFECTIVENESS OF TREATMENT AND THE STAGE OF THE DISEASE. AS THE ETIOLOGY OF ENDOMETRIOSIS IS HIGHLY COMPLEX AND STILL FAR FROM BEING FULLY ELUCIDATED, THE PRESENTED REVIEW FOCUSES ON DIFFERENT APPROACHES TO IDENTIFY THE GENETIC AND EPIGENETIC LINKS OF ENDOMETRIOSIS AND ITS PATHOGENESIS. 2020 6 2086 19 EPIGENETIC DYSREGULATION IN ENDOMETRIOSIS: IMPLICATIONS FOR PATHOPHYSIOLOGY AND THERAPEUTICS. ENDOMETRIOSIS IS A PREVALENT GYNECOLOGICAL CONDITION ASSOCIATED WITH PELVIC PAIN AND INFERTILITY. DESPITE MORE THAN A CENTURY OF RESEARCH, THE ETIOLOGY OF ENDOMETRIOSIS STILL ELUDES SCIENTIFIC CONSENSUS. THIS LACK OF CLARITY HAS RESULTED IN SUBOPTIMAL PREVENTION, DIAGNOSIS, AND TREATMENT OPTIONS. EVIDENCE OF GENETIC CONTRIBUTORS TO ENDOMETRIOSIS IS INTERESTING BUT LIMITED; HOWEVER, SIGNIFICANT PROGRESS HAS BEEN MADE IN RECENT YEARS IN IDENTIFYING EPIGENETIC ROLE IN THE PATHOGENESIS OF ENDOMETRIOSIS THROUGH CLINICAL STUDIES, IN VITRO CELL CULTURE EXPERIMENTS, AND IN VIVO ANIMAL MODELS. THE PREDOMINANT FINDINGS INCLUDE ENDOMETRIOSIS-RELATED DIFFERENTIAL EXPRESSION OF DNA METHYLTRANSFERASES AND DEMETHYLASES, HISTONE DEACETYLASES, METHYLTRANSFERASES, AND DEMETHYLASES, AND REGULATORS OF CHROMATIN ARCHITECTURE. THERE IS ALSO AN EMERGING ROLE FOR MIRNAS IN THE CONTROL OF EPIGENETIC REGULATORS IN THE ENDOMETRIUM AND ENDOMETRIOSIS. CHANGES IN THESE EPIGENETIC REGULATORS RESULT IN DIFFERENTIAL CHROMATIN ORGANIZATION AND DNA METHYLATION WITH CONSEQUENCES FOR GENE EXPRESSION INDEPENDENT OF A GENETIC SEQUENCE. EPIGENETICALLY ALTERED EXPRESSION OF GENES RELATED TO STEROID HORMONE PRODUCTION AND SIGNALING, IMMUNE REGULATION, AND ENDOMETRIAL CELL IDENTITY AND FUNCTION HAVE ALL BEEN IDENTIFIED AND APPEAR TO PLAY INTO THE PATHOPHYSIOLOGICAL MECHANISMS OF ENDOMETRIOSIS AS WELL AS RESULTING INFERTILITY. THIS REVIEW SUMMARIZES AND CRITICALLY DISCUSSES EARLY SEMINAL FINDINGS, THE EVER-GROWING RECENT EVIDENCE OF EPIGENETIC CONTRIBUTIONS TO THE PATHOPHYSIOLOGY OF ENDOMETRIOSIS, AND IMPLICATIONS FOR PROPOSED EPIGENETICALLY TARGETED THERAPEUTICS. 2023 7 146 18 ABERRANT ENDOMETRIAL DNA METHYLOME AND ASSOCIATED GENE EXPRESSION IN WOMEN WITH ENDOMETRIOSIS. ENDOMETRIOSIS IS AN ESTROGEN-DEPENDENT, PROGESTERONE-RESISTANT DISORDER LARGELY DERIVED FROM RETROGRADE TRANSPLANTATION OF MENSTRUAL TISSUE/CELLS INTO THE PELVIS, ELICITING AN INFLAMMATORY RESPONSE, PELVIC PAIN, AND INFERTILITY. EUTOPIC ENDOMETRIUM (WITHIN THE UTERUS), GIVING RISE TO PELVIC DISEASE, DISPLAYS CYCLE-DEPENDENT TRANSCRIPTOMIC, PROTEOMIC, AND SIGNALING ABNORMALITIES, AND ALTHOUGH ITS DNA METHYLATION PROFILES DYNAMICALLY CHANGE ACROSS THE CYCLE IN HEALTHY WOMEN, STUDIES IN ENDOMETRIOSIS ARE LIMITED. HEREIN, WE INVESTIGATED THE DNA METHYLOME AND ASSOCIATED GENE EXPRESSION IN THREE PHASES OF THE CYCLE IN EUTOPIC ENDOMETRIUM OF WOMEN WITH SEVERE ENDOMETRIOSIS VERSUS CONTROLS, MATCHED FOR ETHNICITY, MEDICATIONS, SMOKING, AND NO RECENT CONTRACEPTIVE STEROID USE. GENOME-WIDE DNA METHYLATION AND GENE EXPRESSION WERE COASSESSED IN EACH SAMPLE. CYCLE PHASE WAS DETERMINED BY HISTOLOGY, SERUM HORMONE LEVELS, AND UNSUPERVISED PRINCIPAL COMPONENT AND HIERARCHICAL CLUSTER ANALYSES OF MICROARRAY DATA. ALTERED ENDOMETRIAL DNA METHYLATION IN ENDOMETRIOSIS WAS MOST PROMINENT IN THE MIDSECRETORY PHASE (PEAK PROGESTERONE), WITH DISRUPTION OF THE NORMAL PATTERN OF CYCLE-DEPENDENT DNA METHYLATION CHANGES, INCLUDING A BIAS TOWARD METHYLATION OF CPG ISLANDS, SUGGESTING WIDE-RANGE ABNORMALITIES OF THE CHROMATIN REMODELING MACHINERY IN ENDOMETRIOSIS. DNA METHYLATION CHANGES WERE ASSOCIATED WITH ALTERED GENE EXPRESSION RELEVANT TO ENDOMETRIAL FUNCTION/DYSFUNCTION, INCLUDING CELL PROLIFERATION, INFLAMMATION/IMMUNE RESPONSE, ANGIOGENESIS, AND STEROID HORMONE RESPONSE. THE DATA PROVIDE INSIGHT INTO EPIGENETIC REPROGRAMMING AND STEROID HORMONE ACTIONS IN ENDOMETRIUM CONTRIBUTING TO THE PATHOGENESIS AND PATHOPHYSIOLOGY OF ENDOMETRIOSIS. 2016 8 5318 22 PSYCHONEUROENDOCRINE INTERVENTIONS AIMED AT ATTENUATING IMMUNOSENESCENCE: A REVIEW. THERE IS EVIDENCE SUGGESTING THAT IMMUNOSENESCENCE CAN BE ACCELERATED BY EXTERNAL FACTORS SUCH AS CHRONIC STRESS. HERE WE REVIEW POTENTIAL PSYCHONEUROENDOCRINE DETERMINANTS OF PREMATURE AGING OF THE IMMUNE SYSTEM AND DISCUSS AVAILABLE INTERVENTIONS AIMED AT ATTENUATING IMMUNOSENESCENCE. CHRONIC STRESS MAY ACCELERATE VARIOUS FEATURES OF IMMUNOSENESCENCE BY ACTIVATING KEY ALLOSTATIC SYSTEMS, NOTABLY THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS. THE IMMUNOLOGICAL IMPACT OF SUCH NEUROENDOCRINE DYSREGULATION MAY BE FURTHER AMPLIFIED BY A DRAMATIC DECLINE IN DEHYDROEPIANDROSTERONE (DHEA) LEVELS, ACTING IN PART AS AN ENDOGENOUS GLUCOCORTICOID ANTAGONIST. STRESS-BUFFERING STRATEGIES SHOW BENEFICIAL EFFECTS ON VARIOUS BIOMARKERS IN ELDERLY POPULATIONS. LIKEWISE, SUPPLEMENTATION OF DHEA, MELATONIN OR GROWTH HORMONE HAS YIELDED SIGNIFICANT BENEFICIAL EFFECTS IN A NUMBER OF STUDIES, INCLUDING: INCREASED WELL-BEING, MEMORY PERFORMANCE, BONE MINERAL DENSITY AND IMPROVED IMMUNOCOMPETENCE AS EVIDENCED BY RESULTS OF IN VITRO (T CELL PROLIFERATION, CYTOTOXICITY, CYTOKINE PRODUCTION), AND IN VIVO IMMUNE CHALLENGES. HOWEVER, THE SIDE-EFFECTS OF HORMONAL SUPPLEMENTATION ARE ALSO DISCUSSED. FINALLY, MODERATE EXERCISE VIA THE PROMOTION OF CORTISOL/DHEA BALANCE OR EPIGENETIC MODIFICATIONS, IS ASSOCIATED WITH LOWER SERUM PRO-INFLAMMATORY CYTOKINES, GREATER LYMPHOPROLIFERATIVE RESPONSES AND LOWER COUNTS OF SENESCENT T CELLS. TAKEN TOGETHER, THESE DATA SUGGEST THAT IMMUNE SYSTEM IS PLASTIC AND IMMUNOSENESCENCE CAN BE ATTENUATED PSYCHONEUROENDOCRINE INTERVENTIONS. 2013 9 3148 28 GLUCOCORTICOID INDUCED LOSS OF OESTROGEN RECEPTOR ALPHA GENE METHYLATION AND RESTORATION OF SENSITIVITY TO FULVESTRANT IN TRIPLE NEGATIVE BREAST CANCER. THE RESPONSE TO PSYCHOLOGICAL STRESS CAN DIFFER DEPENDING ON THE TYPE AND DURATION OF THE STRESSOR. ACUTE STRESS CAN FACILITATE A "FIGHT OR FLIGHT RESPONSE" AND AID SURVIVAL, WHEREAS CHRONIC LONG-TERM STRESS WITH THE PERSISTENT RELEASE OF STRESS HORMONES SUCH AS CORTISOL HAS BEEN SHOWN TO BE DETRIMENTAL TO HEALTH. WE ARE NOW BEGINNING TO UNDERSTAND HOW THIS STRESS HORMONE RESPONSE IMPACTS IMPORTANT PROCESSES SUCH AS DNA REPAIR AND CELL PROLIFERATION PROCESSES IN BREAST CANCER. HOWEVER, IT IS NOT KNOWN WHAT EPIGENETIC CHANGES STRESS HORMONES INDUCE IN BREAST CANCER. EPIGENETIC MECHANISMS INCLUDE MODIFICATION OF DNA AND HISTONES WITHIN CHROMATIN THAT MAY BE INVOLVED IN GOVERNING THE TRANSCRIPTIONAL PROCESSES IN CANCER CELLS IN RESPONSE TO CHANGES BY ENDOGENOUS STRESS HORMONES. THE CONTRIBUTION OF ENDOGENOUS ACUTE OR LONG-TERM EXPOSURE OF GLUCOCORTICOID STRESS HORMONES, AND EXOGENOUS GLUCOCORTICOIDS TO METHYLATION PATTERNS IN BREAST CANCER TISSUES WITH DIFFERENT AETIOLOGIES REMAINS TO BE EVALUATED. IN VITRO AND IN VIVO MODELS WERE DEVELOPED TO INVESTIGATE THE EPIGENETIC MODIFICATIONS AND THEIR CONTRIBUTION TO BREAST CANCER PROGRESSION AND AETIOLOGY. A PANEL OF TRIPLE NEGATIVE BREAST CANCER CELL LINES WERE TREATED WITH THE GLUCOCORTICOID, CORTISOL WHICH RESULTED IN EPIGENETIC ALTERATION CHARACTERISED BY LOSS OF METHYLATION ON PROMOTER REGIONS OF TUMOUR SUPPRESSOR GENES INCLUDING ESR1, AND LOSS OF METHYLATION ON LINE-1 REPETITIVE ELEMENT USED AS A SURROGATE MARKER FOR GLOBAL METHYLATION. THIS WAS VERIFIED IN VIVO IN MDA-MB-231 XENOGRAFTS; THE MODEL VERIFIED THE LOSS OF METHYLATION ON ESR1 PROMOTER, AND SUBSEQUENT INCREASE IN ESR1 EXPRESSION IN PRIMARY TUMOURS IN MICE SUBJECTED TO RESTRAINT STRESS. OUR STUDY HIGHLIGHTS THAT DNA METHYLATION LANDSCAPE IN BREAST CANCER CAN BE ALTERED IN RESPONSE TO STRESS AND GLUCOCORTICOID TREATMENT. 2023 10 4957 25 PATHOGENESIS OF ENDOMETRIOSIS: THE GENETIC/EPIGENETIC THEORY. OBJECTIVE: TO STUDY THE PATHOPHYSIOLOGY OF ENDOMETRIOSIS. DESIGN: OVERVIEW OF OBSERVATIONS ON ENDOMETRIOSIS. SETTING: NOT APPLICABLE. PATIENT(S): NONE. INTERVENTIONS(S): NONE. MAIN OUTCOME MEASURE(S): THE HYPOTHESIS IS COMPATIBLE WITH ALL OBSERVATIONS. RESULT(S): ENDOMETRIOSIS, ENDOMETRIUM-LIKE TISSUE OUTSIDE THE UTERUS, HAS A VARIABLE MACROSCOPIC APPEARANCE AND A POORLY UNDERSTOOD NATURAL HISTORY. IT IS A HEREDITARY AND HETEROGENEOUS DISEASE WITH MANY BIOCHEMICAL CHANGES IN THE LESIONS, WHICH ARE CLONAL IN ORIGIN. IT IS ASSOCIATED WITH PAIN, INFERTILITY, ADENOMYOSIS, AND CHANGES IN THE JUNCTIONAL ZONE, PLACENTATION, IMMUNOLOGY, PLASMA, PERITONEAL FLUID, AND CHRONIC INFLAMMATION OF THE PERITONEAL CAVITY. THE SAMPSON HYPOTHESIS OF IMPLANTED ENDOMETRIAL CELLS FOLLOWING RETROGRADE MENSTRUATION, ANGIOGENIC SPREAD, LYMPHOGENIC SPREAD, OR THE METAPLASIA THEORY CANNOT EXPLAIN ALL OBSERVATIONS IF METAPLASIA IS DEFINED AS CELLS WITH REVERSIBLE CHANGES AND AN ABNORMAL BEHAVIOR/MORPHOLOGY DUE TO THE ABNORMAL ENVIRONMENT. WE PROPOSE A POLYGENETIC/POLYEPIGENETIC MECHANISM. THE SET OF GENETIC AND EPIGENETIC INCIDENTS TRANSMITTED AT BIRTH COULD EXPLAIN THE HEREDITARY ASPECTS, THE PREDISPOSITION, AND THE ENDOMETRIOSIS-ASSOCIATED CHANGES IN THE ENDOMETRIUM, IMMUNOLOGY, AND PLACENTATION. TO DEVELOP TYPICAL, CYSTIC OVARIAN OR DEEP ENDOMETRIOSIS LESIONS, A VARIABLE SERIES OF ADDITIONAL TRANSMISSIBLE GENETIC AND EPIGENETIC INCIDENTS ARE REQUIRED TO OCCUR IN A CELL WHICH MAY VARY FROM ENDOMETRIAL TO STEM CELLS. SUBTLE LESIONS ARE VIEWED AS ENDOMETRIUM IN A DIFFERENT ENVIRONMENT UNTIL ADDITIONAL INCIDENTS OCCUR. TYPICAL CYSTIC OVARIAN OR DEEP ENDOMETRIOSIS LESIONS ARE HETEROGENEOUS AND REPRESENT THREE DIFFERENT DISEASES. CONCLUSION(S): THE GENETIC EPIGENETIC THEORY IS COMPATIBLE WITH ALL OBSERVATIONS ON ENDOMETRIOSIS. IMPLICATIONS FOR TREATMENT AND PREVENTION ARE DISCUSSED. 2019 11 898 27 CHRONIC EXPOSURE OF MICE TO BISPHENOL-A ALTERS UTERINE FIBROBLAST GROWTH FACTOR SIGNALING AND LEADS TO ABERRANT EPITHELIAL PROLIFERATION. UTERINE EPITHELIAL PROLIFERATION IS REGULATED IN A PARACRINE MANNER BY A COMPLEX INTERPLAY BETWEEN ESTROGEN (E) AND PROGESTERONE (P) SIGNALING, IN WHICH E STIMULATES PROLIFERATION AND P INHIBITS IT. PERTURBATION OF STEROID HORMONE SIGNALING WITHIN THE UTERINE MILIEU COULD CONTRIBUTE TO THE DEVELOPMENT OF ENDOMETRIAL HYPERPLASIA AND CANCER. IT IS WELL ESTABLISHED THAT BISPHENOL-A (BPA) IS AN ENDOCRINE-DISRUPTING CHEMICAL WITH WEAK ESTROGENIC EFFECTS, ALTHOUGH LITTLE IS KNOWN ABOUT HOW IT AFFECTS STEROID HORMONE SIGNALING IN THE ADULT UTERUS. BECAUSE BPA ACTS AS A WEAK E, WE HYPOTHESIZED THAT CHRONIC EXPOSURE TO BPA WOULD CREATE AN IMBALANCE BETWEEN E AND P SIGNALING AND CAUSE CHANGES IN THE UTERUS, SUCH AS ABERRANT EPITHELIAL PROLIFERATION. INDEED, EXPOSURE TO AN ENVIRONMENTALLY RELEVANT DOSE OF BPA HAD A UTEROTROPHIC AFFECT. BPA-TREATED MICE SHOWED INCREASED PROLIFERATION, NOTABLY IN THE GLANDULAR EPITHELIUM, WHICH ARE SITES OF ORIGIN FOR ENDOMETRIAL HYPERPLASIA AND CANCER. INCREASED PROLIFERATION APPEARED TO BE MEDIATED THROUGH A SIMILAR MECHANISM AS E-INDUCED PROLIFERATION, VIA ACTIVATION OF THE FIBROBLAST GROWTH FACTOR RECEPTOR PATHWAY AND PHOSPHORYLATION OF THE ERK1/2 MITOGEN-ACTIVATED PROTEIN KINASES IN THE EPITHELIUM. INTERESTINGLY, BPA REDUCED EXPRESSION OF HEART AND NEURAL CREST DERIVATIVES EXPRESSED 2 (HAND2), A KNOWN MEDIATOR OF THE ANTIPROLIFERATIVE EFFECTS OF P. BPA ALSO INCREASED METHYLATION OF A CPG ISLAND IN THE HAND2 GENE PROMOTER, SUGGESTING THAT BPA MAY PROMOTE EPITHELIAL PROLIFERATION THROUGH EPIGENETIC SILENCING OF ANTIPROLIFERATIVE FACTORS LIKE HAND2. COLLECTIVELY, THESE FINDINGS ESTABLISH THAT CHRONIC EXPOSURE TO BPA IMPAIRS STEROID HORMONE SIGNALING IN THE MOUSE UTERUS, AND MAY CONTRIBUTE TO THE PATHOGENESIS OF UTERINE HYPERPLASIA AND CANCER. 2019 12 2602 21 EPIGENETICS, ENDOMETRIOSIS AND SEX STEROID RECEPTORS: AN UPDATE ON THE EPIGENETIC REGULATORY MECHANISMS OF ESTROGEN AND PROGESTERONE RECEPTORS IN PATIENTS WITH ENDOMETRIOSIS. ENDOMETRIOSIS IS A BENIGN GYNECOLOGICAL DISEASE AFFECTING APPROXIMATELY 10% OF REPRODUCTIVE-AGED WOMEN AND IS DEFINED AS THE PRESENCE OF ENDOMETRIAL GLANDS AND STROMA OUTSIDE THE UTERINE CAVITY. ENDOMETRIOSIS CAN CAUSE A VARIETY OF HEALTH PROBLEMS, FROM PELVIC DISCOMFORT TO CATAMENIAL PNEUMOTHORAX, BUT IT'S MAINLY LINKED WITH SEVERE AND CHRONIC PELVIC PAIN, DYSMENORRHEA, AND DEEP DYSPAREUNIA, AS WELL AS REPRODUCTIVE ISSUES. THE PATHOGENESIS OF ENDOMETRIOSIS INVOLVES AN ENDOCRINE DYSFUNCTION, WITH ESTROGEN DEPENDENCY AND PROGESTERONE RESISTANCE, AND INFLAMMATORY MECHANISM ACTIVATION, TOGETHER WITH IMPAIRED CELL PROLIFERATION AND NEUROANGIOGENESIS. THE PRESENT CHAPTER AIMS TO DISCUSS THE MAIN EPIGENETIC MECHANISMS RELATED TO ESTROGEN RECEPTORS (ERS) AND PROGESTERONE RECEPTORS (PRS) IN PATIENTS WITH ENDOMETRIOSIS. THERE ARE NUMEROUS EPIGENETIC MECHANISMS PARTICIPATING IN ENDOMETRIOSIS, REGULATING THE EXPRESSION OF THE GENES ENCODING THESE RECEPTORS BOTH INDIRECTLY, THROUGH THE REGULATION OF TRANSCRIPTION FACTORS, AND DIRECTLY, THROUGH DNA METHYLATION, HISTONE MODIFICATIONS, MICRO RNAS AND LONG NONCODING RNAS. THIS REPRESENTS AN OPEN FIELD OF INVESTIGATION, WHICH MAY LEAD TO IMPORTANT CLINICAL IMPLICATIONS SUCH AS THE DEVELOPMENT OF EPIGENETIC DRUGS FOR THE TREATMENT OF ENDOMETRIOSIS AND THE IDENTIFICATION OF SPECIFIC AND EARLY BIOMARKERS FOR THE DISEASE. 2023 13 468 23 ARGININE METHYLTRANSFERASES MEDIATE AN EPIGENETIC OVARIAN RESPONSE TO ENDOMETRIOSIS. ENDOMETRIOSIS IS ASSOCIATED WITH INFERTILITY AND DEBILITATING CHRONIC PAIN. ABNORMAL EPIGENETIC MODIFICATIONS IN THE HUMAN ENDOMETRIUM HAVE RECENTLY BEEN IMPLICATED IN THE PATHOGENESIS OF THIS CONDITION. HOWEVER, WHETHER AN ALTERED EPIGENETIC LANDSCAPE CONTRIBUTES TO PATHOLOGICAL CHANGES IN THE OVARY IS UNKNOWN. USING AN ESTABLISHED BABOON ENDOMETRIOSIS MODEL, EARLY-, AND LATE-STAGE EPIGENETIC CHANGES IN THE OVARY WERE INVESTIGATED. TRANSCRIPT PROFILING OF KEY CHROMATIN-MODIFYING ENZYMES USING PATHWAY-FOCUSED PCR ARRAYS ON OVARIAN TISSUE FROM HEALTHY CONTROL ANIMALS AND AT 3 AND 15 MONTHS OF ENDOMETRIOSIS REVEALED DRAMATIC CHANGES IN GENE EXPRESSION IN A DISEASE DURATION-DEPENDENT MANNER. INGENUITY PATHWAY ANALYSIS INDICATED THAT TRANSCRIPTS FOR CHROMATIN-REMODELING ENZYMES ASSOCIATED WITH REPRODUCTIVE SYSTEM DISEASE AND CANCER DEVELOPMENT WERE ABNORMALLY REGULATED, MOST PROMINENTLY THE ARGININE METHYLTRANSFERASES CARM1, PRMT2, AND PRMT8. DOWNREGULATION OF CARM1 PROTEIN EXPRESSION WAS ALSO DETECTED IN THE OVARY, FULLY-GROWN OOCYTES AND EUTOPIC ENDOMETRIUM FOLLOWING 15 MONTHS OF ENDOMETRIOSIS. SODIUM BISULFITE SEQUENCING REVEALED DNA HYPERMETHYLATION WITHIN THE PRMT8 PROMOTER, SUGGESTING THAT DEREGULATED CPG METHYLATION MAY PLAY A ROLE IN TRANSCRIPTIONAL REPRESSION OF THIS GENE. THESE RESULTS DEMONSTRATE THAT ENDOMETRIOSIS IS ASSOCIATED WITH CHANGES OF EPIGENETIC PROFILES IN THE PRIMATE OVARY AND SUGGEST THAT ARGININE METHYLTRANSFERASES PLAY A PROMINENT ROLE IN MEDIATING THE OVARIAN RESPONSE TO ENDOMETRIOSIS. OWING TO THE CRITICAL ROLE OF CARM1 IN NUCLEAR RECEPTOR-MEDIATED TRANSCRIPTION AND MAINTENANCE OF PLURIPOTENCY IN THE CLEAVAGE STAGE EMBRYO, OUR RESULTS SUGGEST THAT EPIGENETIC ALTERATIONS IN THE OVARY MAY HAVE FUNCTIONAL CONSEQUENCES FOR OOCYTE QUALITY AND THE ETIOLOGY OF INFERTILITY ASSOCIATED WITH ENDOMETRIOSIS. 2015 14 5378 16 RECENT INSIGHTS ON THE GENETICS AND EPIGENETICS OF ENDOMETRIOSIS. ENDOMETRIOSIS IS A GYNECOLOGIC DISEASE AFFECTING UP TO 10% OF THE WOMEN AND A MAJOR CAUSE OF PAIN AND INFERTILITY. IT IS CHARACTERIZED BY THE IMPLANTATION OF FUNCTIONAL ENDOMETRIAL TISSUE AT ECTOPIC POSITIONS GENERALLY WITHIN THE PERITONEUM. THIS COMPLEX DISEASE HAS AN IMPORTANT GENETIC COMPONENT WITH A HERITABILITY ESTIMATED AT AROUND 50%. THIS REVIEW AIMS AT PROVIDING RECENT INSIGHTS INTO THE GENETIC BASES OF ENDOMETRIOSIS, AND PRESENTS A DETAILED OVERVIEW OF EVIDENCE OF EPIGENETIC ALTERATIONS SPECIFIC TO THIS DISEASE. IN THE FUTURE, THESE ALTERATIONS MAY CONSTITUTE THERAPEUTIC TARGETS FOR PHARMACOLOGICAL COMPOUNDS ABLE TO MODIFY THE EPIGENETIC CODE. 2017 15 5239 35 PROGESTERONE ALLEVIATES ENDOMETRIOSIS VIA INHIBITION OF UTERINE CELL PROLIFERATION, INFLAMMATION AND ANGIOGENESIS IN AN IMMUNOCOMPETENT MOUSE MODEL. ENDOMETRIOSIS, DEFINED AS GROWTH OF THE ENDOMETRIAL CELLS OUTSIDE THE UTERUS, IS AN INFLAMMATORY DISORDER THAT IS ASSOCIATED WITH CHRONIC PELVIC PAIN AND INFERTILITY IN WOMEN OF CHILDBEARING AGE. ALTHOUGH THE ESTROGEN-DEPENDENCE OF ENDOMETRIOSIS IS WELL KNOWN, THE ROLE OF PROGESTERONE IN DEVELOPMENT OF THIS DISEASE REMAINS POORLY UNDERSTOOD. IN THIS STUDY, WE DEVELOPED A DISEASE MODEL IN WHICH ENDOMETRIOSIS WAS INDUCED IN THE PERITONEAL CAVITIES OF IMMUNOCOMPETENT FEMALE MICE, AND MAINTAINED WITH EXOGENOUS ESTROGEN. THE ENDOMETRIOSIS-LIKE LESIONS THAT WERE IDENTIFIED AT A VARIETY OF ECTOPIC LOCATIONS EXHIBITED ABUNDANT BLOOD SUPPLY AND EXTENSIVE ADHESIONS. HISTOLOGICAL EXAMINATION REVEALED THAT THESE LESIONS HAD A WELL-ORGANIZED ENDOMETRIAL ARCHITECTURE AND FIBROTIC RESPONSE, RESEMBLING THOSE RECOVERED FROM CLINICAL PATIENTS. IN ADDITION, AN EXTENSIVE PROLIFERATION, INFLAMMATORY RESPONSE, AND LOSS OF ESTROGEN RECEPTOR ALPHA (ERALPHA) AND PROGESTERONE RECEPTOR (PR) EXPRESSION WERE ALSO OBSERVED IN THESE LESIONS. INTERESTINGLY, ADMINISTRATION OF PROGESTERONE BEFORE, BUT NOT AFTER, LESION INDUCTION SUPPRESSED LESION EXPANSION AND MAINTAINED ERALPHA AND PR EXPRESSIONS. THESE PROGESTERONE-PRETREATED LESIONS EXHIBITED ATTENUATION IN KI67, CD31, AND PRO-INFLAMMATORY CYTOKINE EXPRESSION AS WELL AS MACROPHAGE INFILTRATION, INDICATING THAT PROGESTERONE AMELIORATES ENDOMETRIOSIS PROGRESSION BY INHIBITING CELL PROLIFERATION, INFLAMMATION AND NEOVASCULARIZATION. OUR STUDIES FURTHER SHOWED THAT SUPPRESSION OF GLOBAL DNA METHYLATION BY APPLICATION OF DNA METHYLTRANSFERASE INHIBITOR TO FEMALE MICE BEARING ECTOPIC LESIONS RESTRAINED LESION EXPANSION AND RESTORED ERALPHA AND PR EXPRESSION IN EUTOPIC ENDOMETRIUM AND ECTOPIC LESIONS. THESE RESULTS INDICATE THAT EPIGENETIC REGULATION OF TARGET GENE EXPRESSION VIA DNA METHYLATION CONTRIBUTES, AT LEAST IN PART, TO PROGESTERONE RESISTANCE IN ENDOMETRIOSIS. 2016 16 2119 27 EPIGENETIC HISTONE MODIFICATION REGULATES DEVELOPMENTAL LEAD EXPOSURE INDUCED HYPERACTIVITY IN RATS. LEAD (PB) EXPOSURE WAS COMMONLY CONSIDERED AS A HIGH ENVIRONMENTAL RISK FACTOR FOR THE DEVELOPMENT OF ATTENTION-DEFICIT/HYPERACTIVITY DISORDER (ADHD). HOWEVER, THE MOLECULAR BASIS OF THIS PATHOLOGICAL PROCESS STILL REMAINS ELUSIVE. IN LIGHT OF THE ROLE OF EPIGENETICS IN MODULATING THE NEUROLOGICAL DISEASE AND THE CAUSATIVE ENVIRONMENT, THE ALTERATIONS OF HISTONE MODIFICATIONS IN THE HIPPOCAMPUS OF RATS EXPOSED BY VARIOUS DOSES OF LEAD, ALONG WITH CONCOMITANT BEHAVIORAL DEFICITS, WERE INVESTIGATED IN THIS STUDY. ACCORDING TO THE FREE AND FORCED OPEN FIELD TEST, THERE SHOWED THAT IN A DOSAGE-DEPENDENT MANNER, LEAD EXPOSURE COULD RESULT IN THE INCREASED LOCOMOTOR ACTIVITY OF RATS, THAT IS, HYPERACTIVITY: A SUBTYPE OF ADHD. WESTERN BLOTTING ASSAYS REVEALED THAT THE LEVELS OF HISTONE ACETYLATION INCREASED SIGNIFICANTLY IN THE HIPPOCAMPUS BY CHRONIC LEAD EXPOSURE, WHILE NO DRAMATIC CHANGES WERE DETECTED IN TERMS OF EXPRESSION YIELDS OF ADHD-RELATED DOPAMINERGIC PROTEINS, INDICATING THAT HISTONE ACETYLATION PLAYS ESSENTIAL ROLES IN THIS TOXICANT-INVOLVED PATHOGENESIS. IN ADDITION, THE INCREASED LEVEL OF HISTONE ACETYLATION MIGHT BE ATTRIBUTED TO THE ENZYMATIC ACTIVITY OF P300, A TYPICAL HISTONE ACETYLTRANSFERASE, AS THE TRANSCRIPTIONAL LEVEL OF P300 WAS SIGNIFICANTLY INCREASED UPON HIGHER-DOSE PB EXPOSURE. IN SUMMARY, THIS STUDY FIRST DISCOVERED THE EPIGENETIC MECHANISM BRIDGING THE ENVIRONMENTAL INFLUENCE (PB) AND THE DISEASE ITSELF (ADHD) IN THE HISTONE MODIFICATION LEVEL, PAVING THE WAY FOR THE COMPREHENSIVE UNDERSTANDING OF ADHD'S ETIOLOGY AND IN FURTHER STEPS, ESTABLISHING THE THERAPY STRATEGY OF THIS WIDESPREAD NEUROLOGICAL DISORDER. 2014 17 4093 23 MATERNAL SEPARATION FOLLOWED BY CHRONIC MILD STRESS IN ADULTHOOD IS ASSOCIATED WITH CONCERTED EPIGENETIC REGULATION OF AP-1 COMPLEX GENES. DEPRESSION IS ONE OF THE MOST PREVALENT MENTAL DISEASES WORLDWIDE. PATIENTS WITH PSYCHIATRIC DISEASES OFTEN HAVE A HISTORY OF CHILDHOOD NEGLECT, INDICATING THAT EARLY-LIFE EXPERIENCES PREDISPOSE TO PSYCHIATRIC DISEASES IN ADULTHOOD. TWO STRONG MODELS WERE USED IN THE PRESENT STUDY: THE MATERNAL SEPARATION/EARLY DEPRIVATION MODEL (MS) AND THE CHRONIC MILD STRESS MODEL (CMS). IN BOTH MODELS, WE FOUND CHANGES IN THE EXPRESSION OF A NUMBER OF GENES SUCH AS CREB AND NPY. STRIKINGLY, THERE WAS A CLEAR REGULATION OF EXPRESSION OF FOUR GENES INVOLVED IN THE AP-1 COMPLEX: C-FOS, C-JUN, FOSB, AND JUN-B. INTERESTINGLY, DIFFERENT EXPRESSION LEVELS WERE OBSERVED DEPENDING ON THE MODEL, WHEREAS THE COMBINATION OF THE MODELS RESULTED IN A NORMAL LEVEL OF GENE EXPRESSION. THE EFFECTS OF MS AND CMS ON GENE EXPRESSION WERE ASSOCIATED WITH DISTINCT HISTONE METHYLATION/ACETYLATION PATTERNS OF ALL FOUR GENES. THE EPIGENETIC CHANGES, LIKE GENE EXPRESSION, WERE ALSO DEPENDENT ON THE SPECIFIC STRESSOR OR THEIR COMBINATION. THE OBTAINED RESULTS SUGGEST THAT SINGLE LIFE EVENTS LEAVE A MARK ON GENE EXPRESSION AND THE EPIGENETIC SIGNATURE OF GENE PROMOTERS, BUT A COMBINATION OF DIFFERENT STRESSORS AT DIFFERENT LIFE STAGES CAN FURTHER CHANGE GENE EXPRESSION THROUGH EPIGENETIC FACTORS, POSSIBLY CAUSING THE LONG-LASTING ADVERSE EFFECTS OF STRESS. 2021 18 5756 17 SOCIOECONOMIC DEPRIVATION, ADVERSE CHILDHOOD EXPERIENCES AND MEDICAL DISORDERS IN ADULTHOOD: MECHANISMS AND ASSOCIATIONS. SEVERE SOCIOECONOMIC DEPRIVATION (SED) AND ADVERSE CHILDHOOD EXPERIENCES (ACE) ARE SIGNIFICANTLY ASSOCIATED WITH THE DEVELOPMENT IN ADULTHOOD OF (I) ENHANCED INFLAMMATORY STATUS AND/OR HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS DYSFUNCTION AND (II) NEUROLOGICAL, NEUROPROGRESSIVE, INFLAMMATORY AND AUTOIMMUNE DISEASES. THE MECHANISMS BY WHICH THESE ASSOCIATIONS TAKE PLACE ARE DETAILED. THE TWO SETS OF CONSEQUENCES ARE THEMSELVES STRONGLY ASSOCIATED, WITH THE FIRST SET LIKELY CONTRIBUTING TO THE SECOND. MECHANISMS ENABLING BIDIRECTIONAL COMMUNICATION BETWEEN THE IMMUNE SYSTEM AND THE BRAIN ARE DESCRIBED, INCLUDING COMPLEX SIGNALLING PATHWAYS FACILITATED BY FACTORS AT THE LEVEL OF IMMUNE CELLS. ALSO DETAILED ARE MECHANISMS UNDERPINNING THE ASSOCIATION BETWEEN SED, ACE AND THE GENESIS OF PERIPHERAL INFLAMMATION, INCLUDING EPIGENETIC CHANGES TO IMMUNE SYSTEM-RELATED GENE EXPRESSION. THE DURATION AND MAGNITUDE OF INFLAMMATORY RESPONSES CAN BE INFLUENCED BY GENETIC FACTORS, INCLUDING SINGLE NUCLEOTIDE POLYMORPHISMS, AND BY EPIGENETIC FACTORS, WHEREBY PRO-INFLAMMATORY CYTOKINES, REACTIVE OXYGEN SPECIES, REACTIVE NITROGEN SPECIES AND NUCLEAR FACTOR-KAPPAB AFFECT GENE DNA METHYLATION AND HISTONE ACETYLATION AND ALSO INDUCE SEVERAL MICRORNAS INCLUDING MIR-155, MIR-181B-1 AND MIR-146A. ADULT HPA AXIS ACTIVITY IS REGULATED BY (I) GENETIC FACTORS, SUCH AS GLUCOCORTICOID RECEPTOR POLYMORPHISMS; (II) EPIGENETIC FACTORS AFFECTING GLUCOCORTICOID RECEPTOR FUNCTION OR EXPRESSION, INCLUDING THE METHYLATION STATUS OF ALTERNATIVE PROMOTER REGIONS OF NR3C1 AND THE METHYLATION OF FKBP5 AND HSD11BETA2; (III) CHRONIC INFLAMMATION AND CHRONIC NITROSATIVE AND OXIDATIVE STRESS. FINALLY, IT IS SHOWN HOW SEVERE PSYCHOLOGICAL STRESS ADVERSELY AFFECTS MITOCHONDRIAL STRUCTURE AND FUNCTIONING AND IS ASSOCIATED WITH CHANGES IN BRAIN MITOCHONDRIAL DNA COPY NUMBER AND TRANSCRIPTION; MITOCHONDRIA CAN ACT AS COURIERS OF CHILDHOOD STRESS INTO ADULTHOOD. 2019 19 6116 19 THE EPIGENETIC CORRELATION AMONG OVARIAN CANCER, ENDOMETRIOSIS AND PCOS: A REVIEW. OVARIAN CANCER IS A FREQUENT MALIGNANCY THAT AFFECTS A LARGE PERCENTAGE OF WOMEN. ENDOMETRIOSIS IS A CHRONIC CONDITION, WHERE THERE IS A PRODUCTION OF BENIGN LESIONS WERE OBSERVED IN THE UTERINE ENVIRONMENT. PCOS IS A METABOLIC DISORDER CHARACTERIZED BY THE PRESENCE OF NUMEROUS CYSTS IN THE OVARIES. THE RELATION BETWEEN OVARIAN MALIGNANCIES AND PCOS, BY AN INCREASED RATIO OF OVARIAN STROMAL TISSUES IN PCOS PATIENTS. THE DIRECT CORRELATION IS NOT YET CONFIRMED AMONG THE THREE DISORDERS, BUT IT IS OFTEN NOTED THAT THEY SHARE RISK FACTORS, SUCH AS OBESITY, HORMONAL IMBALANCES. EPIGENETIC FACTORS HAVE SHOWN TO BE AN IMPORTANT REASON FOR CANCER PROGRESSION. OUR FINDINGS AT THE EPIGENETIC LEVEL INCLUDES A COMPARATIVE ANALYSIS, POINT MUTATIONS IN GENES, OVERACTIVATION OF SIGNALING PATHWAYS. THIS REVIEW PAPER, HIGHLIGHT THE POSSIBLE CORRELATION BETWEEN THE THREE DISORDERS IN TERMS OF GENETIC AND EPIGENETIC FACTORS AND HOW IT COULD TOGETHER TRIGGER THE CANCER PROGRESSION AND METASTASIS. 2022 20 5645 23 SEX DEPENDENT ALTERATION OF EPIGENETIC MARKS AFTER CHRONIC MORPHINE TREATMENT IN MICE ORGANS. EPIGENETIC MARKS MAY BE ALSO AFFECTED BY SEVERAL FACTORS, SUCH AS AGE, LIFESTYLE, EARLY LIFE EXPERIENCES AND EXPOSURE TO CHEMICALS OR DRUGS, SUCH AS OPIOIDS. PREVIOUS STUDIES HAVE FOCUSED ON HOW MORPHINE EPIGENETICALLY REGULATES DIFFERENT REGIONS OF THE BRAIN THAT ARE IMPLICATED IN TOLERANCE, DEPENDENCE AND OTHER PSYCHIATRIC DISORDERS MORE RELATED TO THE PHYSIO-PATHOLOGICAL EFFECTS OF OPIOIDS. NEVERTHELESS, A SIGNIFICANT KNOWLEDGE GAP REMAINS REGARDING THE EFFECT OF CHRONIC TREATMENT ON OTHER ORGANS AND BIOLOGICAL SYSTEMS. THEREFORE, THE AIM OF THIS WORK IS TO INCREASE OUR KNOWLEDGE ABOUT THE IMPACT OF CHRONIC MORPHINE EXPOSURE ON DNA METHYLATION AND HISTONE MODIFICATION LEVELS IN EACH OF THE ORGANS OF MALE AND FEMALE MODEL MICE IN VIVO. OUR RESULTS REVEAL, FOR THE FIRST TIME, THAT CHRONIC MORPHINE TREATMENT INDUCED CHANGES IN DNA METHYLATION/HYDROXYMETHYLATION AND HISTONE MODIFICATION IN-VIVO AT THE SYSTEMIC LEVEL, REVEALING A POTENTIAL PHYSIOLOGICAL EFFECT ON THE REGULATION OF GENE EXPRESSION. NOTABLY, MORPHINE-INDUCED EPIGENETIC MODIFICATION OCCURS IN A SEX-DEPENDENT MANNER, REVEALING THE EXISTENCE OF DIFFERENT UNDERLYING MECHANISMS OF EPIGENETIC MODIFICATION IN MALE AND FEMALE MICE. 2021