1 1447 88 DIOXIN AND ENDOMETRIOSIS: A NEW POSSIBLE RELATION BASED ON EPIGENETIC THEORY. ENDOMETRIOSIS IS A CHRONIC DISEASE CHARACTERIZED BY THE GROWTH OF ENDOMETRIAL-LIKE GLANDS AND STROMA OUTSIDE THE UTERINE CAVITY. NOWADAYS, THE EXACT ETIOLOGY OF ENDOMETRIOSIS IS UNCLEAR AND THE INTERACTION BETWEEN A VARIETY OF ENVIRONMENTAL PHYSICAL AND CHEMICAL COMPOUNDS MAY POTENTIALLY PROMOTE THE DISEASE IN WOMEN WITH AN INDIVIDUAL SUSCEPTIBILITY. THE FIRST DEMONSTRATION OF A RELATION BETWEEN AN ENVIRONMENTAL FACTOR AND ENDOMETRIOSIS WAS OBTAINED WITH THE CHRONIC DIETARY EXPOSURE OF A PRIMATE COLONY TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD). BESIDES THE WELL-KNOWN DIOXIN'S PATHWAY OF ACTION, SEVERAL PAPERS ARE FOCUSING ON THE ROLE OF EPIGENETIC MECHANISMS, A WAY THROUGH WHICH THE GENOME RESPONDS TO THE ENVIRONMENT AND CAN LEAD TO PERMANENT CHANGES IN GENE EXPRESSION UNTIL AFFECTING THE PHENOTYPES OR CAUSE DISEASE. IN THIS REVIEW, WE FOCUS ON THE POSSIBLE ROLE OF DIOXIN EPIGENETICS MODIFICATION IN ENDOMETRIOSIS. 2020 2 5242 31 PROGESTERONE RESISTANCE IN ENDOMETRIOSIS: ORIGINS, CONSEQUENCES AND INTERVENTIONS. ENDOMETRIOSIS IS A COMMON CAUSE OF PELVIC PAIN AND AFFECTS UP TO 10% OF WOMEN OF REPRODUCTIVE AGE. ABERRANT PROGESTERONE SIGNALING IN THE ENDOMETRIUM PLAYS A SIGNIFICANT ROLE IN IMPAIRED DECIDUALIZATION AND ESTABLISHMENT OF ECTOPIC ENDOMETRIAL IMPLANTS. EUTOPIC ENDOMETRIAL CELLS FROM WOMEN WITH ENDOMETRIOSIS FAIL TO DOWNREGULATE GENES NEEDED FOR DECIDUALIZATION, SUCH AS THOSE INVOLVED IN CELL CYCLE REGULATION, LEADING TO UNBRIDLED PROLIFERATION. SEVERAL CAUSES OF PROGESTERONE RESISTANCE IN THE ENDOMETRIUM HAVE BEEN POSTULATED, INCLUDING CONGENITAL "PRECONDITIONING", WHEREBY THE IN UTERO ENVIRONMENT RENDERS INFANTS SUSCEPTIBLE TO NEONATAL UTERINE BLEEDING AND ENDOMETRIOSIS. PROGESTERONE ACTION IS CRUCIAL TO DECREASING INFLAMMATION IN THE ENDOMETRIUM, AND DEVIANT PROGESTERONE SIGNALING RESULTS IN A PROINFLAMMATORY PHENOTYPE. CONVERSELY, CHRONIC INFLAMMATION CAN INDUCE A PROGESTERONE-RESISTANT STATE. REPETITIVE RETROGRADE ENDOMETRIAL SHEDDING BEGETS CHRONIC PERITONEAL INFLAMMATION, WHICH FURTHER EXACERBATES PROGESTERONE RESISTANCE. GENETIC CAUSES OF PROGESTERONE RESISTANCE INCLUDE PROGESTERONE RECEPTOR GENE POLYMORPHISMS, ALTERED MICRORNA EXPRESSION, AND EPIGENETIC MODIFICATIONS TO PROGESTERONE RECEPTORS AND THEIR TARGETS. ENVIRONMENTAL TOXINS SUCH AS DIOXIN PLAY A POSSIBLE ROLE IN THE GENESIS OF ENDOMETRIOSIS BY PERMITTING AN INFLAMMATORY MILIEU. A CONSEQUENCE OF IMPAIRED PROGESTERONE ACTION IS THAT HORMONAL THERAPY IS RENDERED INEFFECTIVE FOR A SUBSET OF WOMEN WITH ENDOMETRIOSIS. SYNTHETIC PROGESTINS, SUCH AS DIENOGEST, MAY OVERCOME THIS PHENOMENON BY INCREASING PROGESTERONE RECEPTOR EXPRESSION AND DECREASING PROINFLAMMATORY CYTOKINES. OTHER MODALITIES INCLUDE HIGH DOSE DEPOT FORMULATIONS OF PROGESTINS, MEDICATED INTRAUTERINE DEVICES AND THE LIKELY ADVENT OF ORAL GNRH ANTAGONISTS. UNEARTHING ROOT CAUSES OF PROGESTERONE INACTION IN ENDOMETRIOSIS WILL AID IN THE DEVELOPMENT OF NOVEL THERAPEUTICS GEARED TOWARD PREVENTION AND TREATMENT. 2017 3 2466 33 EPIGENETIC THERAPY: NOVEL TRANSLATIONAL IMPLICATIONS FOR ARREST OF ENVIRONMENTAL DIOXIN-INDUCED DISEASE IN FEMALES. INCREASED TOXICANT EXPOSURE AND RESULTANT ENVIRONMENTALLY INDUCED DISEASES ARE A TRADEOFF OF INDUSTRIAL PRODUCTIVITY. DIOXIN [2,3,7,8 TETRACHLORODIBENZO-P-DIOXIN (TCDD)], A UBIQUITOUS BYPRODUCT, IS ASSOCIATED WITH A SPECTRUM OF DISEASES INCLUDING ENDOMETRIOSIS, A COMMON, CHRONIC DISEASE IN WOMEN. TCDD ACTIVATES CYTOCHROME (CYP) P450 METABOLIC ENZYMES THAT ALTER ORGAN FUNCTION TO CAUSE DISEASE. IN CONTRAST, THE TRANSCRIPTION FACTOR, KRUPPEL-LIKE FACTOR (KLF) 11, REPRESSES THESE ENZYMES VIA EPIGENETIC MECHANISMS. IN THIS STUDY, WE CHARACTERIZED THESE OPPOSING MECHANISMS IN VITRO AND IN VIVO AS WELL AS DETERMINING POTENTIAL TRANSLATIONAL IMPLICATIONS OF EPIGENETIC INHIBITOR THERAPY. KLF11 ANTAGONIZED TCDD-MEDIATED ACTIVATION OF CYP3A4 GENE EXPRESSION AND FUNCTION IN ENDOMETRIAL CELLS. THE REPRESSION WAS PHARMACOLOGICALLY REPLICATED BY SELECTIVE USE OF AN EPIGENETIC HISTONE ACETYLTRANSFERASE INHIBITOR (HATI). WE FURTHER SHOWED PHENOTYPIC RELEVANCE OF THIS MECHANISM USING AN ANIMAL MODEL FOR ENDOMETRIOSIS. FIBROTIC EXTENT IN TCDD-EXPOSED WILD-TYPE ANIMALS WAS SIMILAR TO THAT PREVIOUSLY OBSERVED IN KLF11-/- ANIMALS. WHEN TCDD-EXPOSED ANIMALS WERE TREATED WITH A HATI, CYP3 MESSENGER RNA LEVELS AND PROTEIN EXPRESSION DECREASED ALONG WITH DISEASE PROGRESSION. FIBROTIC PROGRESSION IS UBIQUITOUS IN ENVIRONMENTALLY INDUCED CHRONIC, UNTREATABLE DISEASES; THIS REPORT SHOWS THAT RELENTLESS DISEASE PROGRESSION CAN BE ARRESTED THROUGH TARGETED EPIGENETIC MODULATION OF PROTECTIVE MECHANISMS. 2018 4 1767 30 EARLY-LIFE EXPOSURE TO ENDOCRINE DISRUPTING CHEMICALS AND LATER-LIFE HEALTH OUTCOMES: AN EPIGENETIC BRIDGE? A GROWING BODY OF EVIDENCE DEMONSTRATES THAT ADVERSE EVENTS EARLY IN DEVELOPMENT, AND PARTICULARLY DURING INTRAUTERINE LIFE, MAY PROGRAM RISKS FOR DISEASES IN ADULT LIFE. INCREASING EVIDENCE HAS BEEN ACCUMULATED INDICATING THE IMPORTANT ROLE OF EPIGENETIC REGULATION INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS AND MIRNAS IN DEVELOPMENTAL PROGRAMMING. AMONG THE ENVIRONMENTAL FACTORS WHICH PLAY AN IMPORTANT ROLE IN PROGRAMMING OF CHRONIC PATHOLOGIES, THE ENDOCRINE-DISRUPTING CHEMICALS (EDCS) THAT HAVE ESTROGENIC, ANTI-ESTROGENIC, AND ANTI-ANDROGENIC ACTIVITY ARE OF SPECIFIC CONCERN BECAUSE THE DEVELOPING ORGANISM IS EXTREMELY SENSITIVE TO PERTURBATION BY SUBSTANCES WITH HORMONE-LIKE ACTIVITY. AMONG EDCS, THERE ARE MANY SUBSTANCES THAT ARE CONSTANTLY PRESENT IN THE MODERN HUMAN ENVIRONMENT OR ARE IN WIDESPREAD USE, INCLUDING DIOXIN AND DIOXIN-LIKE COMPOUNDS, PHTHALATES, AGRICULTURAL PESTICIDES, POLYCHLORINATED BIPHENYLS, INDUSTRIAL SOLVENTS, PHARMACEUTICALS, AND HEAVY METALS. APART FROM THEIR COMMON ENDOCRINE ACTIVE PROPERTIES, SEVERAL EDCS HAVE BEEN SHOWN TO DISRUPT DEVELOPMENTAL EPIGENOMIC PROGRAMMING. THE PURPOSE OF THIS REVIEW IS TO PROVIDE A SUMMARY OF RECENT RESEARCH FINDINGS WHICH INDICATE THAT EXPOSURE TO EDCS DURING IN-UTERO AND/OR NEONATAL DEVELOPMENT CAN CAUSE LONG-TERM HEALTH OUTCOMES VIA MECHANISMS OF EPIGENETIC MEMORY. 2014 5 6069 24 THE DIOXIN RECEPTOR IS SILENCED BY PROMOTER HYPERMETHYLATION IN HUMAN ACUTE LYMPHOBLASTIC LEUKEMIA THROUGH INHIBITION OF SP1 BINDING. THE TRANSCRIPTION FACTOR ARYL HYDROCARBON RECEPTOR (AHR) HAS RELEVANT FUNCTIONS IN CELL PROLIFERATION. INTERESTINGLY, THE AHR CAN EITHER PROMOTE OR INHIBIT PROLIFERATION DEPENDING ON THE CELL PHENOTYPE. ALTHOUGH RECENT DATA REVEAL POTENTIAL PATHWAYS FOR AHR SIGNALING IN CELL PROLIFERATION, THE MECHANISMS THAT REGULATE ITS ACTIVITY IN TUMOR CELLS REMAIN UNKNOWN. HERE, WE HAVE ANALYZED PROMOTER HYPERMETHYLATION AS A POTENTIAL MECHANISM CONTROLLING AHR EXPRESSION IN HUMAN TUMOR CELLS. AHR PROMOTER CPG METHYLATION WAS SPORADIC IN A PANEL OF 19 TUMOR CELL LINES EXCEPT FOR THE CHRONIC MYELOID LEUKEMIA (CML) K562 AND THE ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) REH. WHEN COMPARED WITH NORMAL LYMPHOCYTES, REH HAD VERY LOW CONSTITUTIVE AHR EXPRESSION THAT COULD BE ATTRIBUTED TO PROMOTER HYPERMETHYLATION SINCE TREATMENT WITH THE DNA DEMETHYLATING AGENT 5-AZA-2'-DEOXYCITIDINE (AZA) SIGNIFICANTLY INCREASED AHR MRNA AND PROTEIN. THESE RESULTS IN LEUKEMIA-DERIVED CELL LINES WERE FURTHER CONFIRMED IN PRIMARY ALL, WHERE 33% OF THE PATIENTS (7/21) HAD AHR PROMOTER HYPERMETHYLATION. CHROMATIN IMMUNOPRECIPITATION (CHIP) SHOWED THAT METHYLATION IMPAIRED BINDING OF THE TRANSCRIPTION FACTOR SP1 TO THE AHR PROMOTER, THUS PROVIDING A MECHANISM FOR AHR DOWNREGULATION IN REH CELLS. THEREFORE, PROMOTER HYPERMETHYLATION REPRESENTS A NOVEL EPIGENETIC MECHANISM DOWNREGULATING AHR ACTIVITY IN HEMATOLOGICAL MALIGNANCIES SUCH AS ALL. 2006 6 5192 28 PRENATAL ENVIRONMENTAL STRESSORS AND DNA METHYLATION LEVELS IN PLACENTA AND PERIPHERAL TISSUES OF MOTHERS AND NEONATES EVALUATED BY APPLYING ARTIFICIAL NEURAL NETWORKS. EXPOSURE TO ENVIRONMENTAL STRESSORS DURING PREGNANCY PLAYS AN IMPORTANT ROLE IN INFLUENCING SUBSEQUENT SUSCEPTIBILITY TO CERTAIN CHRONIC DISEASES THROUGH THE MODULATION OF EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION. OUR AIM WAS TO EXPLORE THE CONNECTIONS BETWEEN ENVIRONMENTAL EXPOSURES DURING GESTATION WITH DNA METHYLATION OF PLACENTAL CELLS, MATERNAL AND NEONATAL BUCCAL CELLS BY APPLYING ARTIFICIAL NEURAL NETWORKS (ANNS). A TOTAL OF 28 MOTHER-INFANT PAIRS WERE ENROLLED. DATA ON GESTATIONAL EXPOSURE TO ADVERSE ENVIRONMENTAL FACTORS AND ON MOTHER HEALTH STATUS WERE COLLECTED THROUGH THE ADMINISTRATION OF A QUESTIONNAIRE. DNA METHYLATION ANALYSES AT BOTH GENE-SPECIFIC AND GLOBAL LEVEL WERE ANALYZED IN PLACENTAS, MATERNAL AND NEONATAL BUCCAL CELLS. IN THE PLACENTA, THE CONCENTRATIONS OF VARIOUS METALS AND DIOXINS WERE ALSO ANALYZED. ANALYSIS OF ANNS REVEALED THAT SUBOPTIMAL BIRTH WEIGHT IS ASSOCIATED WITH PLACENTAL H19 METHYLATION, MATERNAL STRESS DURING PREGNANCY WITH METHYLATION LEVELS OF NR3C1 AND BDNF IN PLACENTAS AND MOTHER'S BUCCAL DNA, RESPECTIVELY, AND EXPOSURE TO AIR POLLUTANTS WITH MATERNAL MGMT METHYLATION. ASSOCIATIONS WERE ALSO OBSERVED BETWEEN PLACENTAL CONCENTRATIONS OF LEAD, CHROMIUM, CADMIUM AND MERCURY WITH METHYLATION LEVELS OF OXTR IN PLACENTAS, HSD11B2 IN MATERNAL BUCCAL CELLS AND PLACENTAS, MECP2 IN NEONATAL BUCCAL CELLS, AND MTHFR IN MATERNAL BUCCAL CELLS. FURTHERMORE, DIOXIN CONCENTRATIONS WERE ASSOCIATED WITH PLACENTAL RELN, NEONATAL HSD11B2 AND MATERNAL H19 GENE METHYLATION LEVELS. CURRENT RESULTS SUGGEST THAT EXPOSURE OF PREGNANT WOMEN TO ENVIRONMENTAL STRESSORS DURING PREGNANCY COULD INDUCE ABERRANT METHYLATION LEVELS IN GENES LINKED TO SEVERAL PATHWAYS IMPORTANT FOR EMBRYOGENESIS IN BOTH THE PLACENTA, POTENTIALLY AFFECTING FOETAL DEVELOPMENT, AND IN THE PERIPHERAL TISSUES OF MOTHERS AND INFANTS, POTENTIALLY PROVIDING PERIPHERAL BIOMARKERS OF ENVIRONMENTAL EXPOSURE. 2023 7 3999 21 LOSS OF HDAC3 RESULTS IN NONRECEPTIVE ENDOMETRIUM AND FEMALE INFERTILITY. ENDOMETRIOSIS IS A DISEASE IN WHICH TISSUE THAT NORMALLY GROWS INSIDE THE UTERUS GROWS OUTSIDE THE UTERUS AND CAUSES CHRONIC PELVIC PAIN AND INFERTILITY. HOWEVER, THE EXACT MECHANISMS OF THE PATHOGENESIS OF ENDOMETRIOSIS-ASSOCIATED INFERTILITY ARE UNKNOWN. EPIGENETIC DYSREGULATION HAS RECENTLY BEEN IMPLICATED IN INFERTILITY. HERE, WE REPORT A REDUCTION OF HISTONE DEACETYLASE 3 (HDAC3) PROTEIN AMOUNTS IN EUTOPIC ENDOMETRIUM OF INFERTILE WOMEN WITH ENDOMETRIOSIS COMPARED TO A CONTROL GROUP. TO INVESTIGATE THE EFFECT OF HDAC3 LOSS IN THE UTERUS, WE GENERATED MICE WITH CONDITIONAL ABLATION OF HDAC3 IN PROGESTERONE RECEPTOR (PGR)-POSITIVE CELLS (PGR(CRE/+)HDAC3(F/F) ; HDAC3(D/D) ). LOSS OF HDAC3 IN THE UTERUS OF MICE RESULTS IN INFERTILITY DUE TO IMPLANTATION FAILURE AND DECIDUALIZATION DEFECT. EXPRESSION MICROARRAY AND CHIP-SEQ ANALYSES IDENTIFIED COL1A1 AND COL1A2 AS DIRECT TARGETS OF HDAC3 IN BOTH MICE AND HUMANS. REDUCTION OF HDAC3 ABROGATED DECIDUALIZATION IN A PRIMARY CULTURE OF HUMAN ENDOMETRIAL STROMAL CELLS (HESCS) SIMILAR TO THAT OBSERVED IN INFERTILE PATIENTS WITH ENDOMETRIOSIS. WHEREAS ATTENUATION OF HDAC3 RESULTED IN P300 RECRUITMENT TO COL1A1 AND COL1A2 GENES IN THE UTERUS OF MICE AS WELL AS HESCS, INHIBITION OF P300 PERMITTED HESCS TO UNDERGO DECIDUALIZATION. COLLECTIVELY, WE FOUND ATTENUATION OF HDAC3 AND OVEREXPRESSION OF COLLAGEN TYPE I IN THE EUTOPIC ENDOMETRIUM OF INFERTILE PATIENTS WITH ENDOMETRIOSIS. HDAC3 LOSS CAUSED A DEFECT OF DECIDUALIZATION THROUGH THE ABERRANT TRANSCRIPTIONAL ACTIVATION OF COL1A1 AND COL1A2 GENES IN MICE AND COL1A1 AND COL1A2 GENES IN HUMANS. OUR RESULTS SUGGEST THAT HDAC3 IS CRITICAL FOR ENDOMETRIAL RECEPTIVITY AND DECIDUALIZATION. 2019 8 1501 14 DNA METHYLATION ANALYSIS OF HUMAN TISSUE-SPECIFIC CONNEXIN GENES. CONNEXINS ARE THE STRUCTURAL PROTEINS OF GAP JUNCTIONS AND THEIR FUNCTIONING AS TUMOR SUPPRESSORS IS WELL KNOWN. EPIGENETIC MODIFICATIONS, SUCH AS METHYLATION OF CONNEXIN GENES, PLAY IMPORTANT ROLES IN REGULATING GENE EXPRESSION. OVER THE PAST DECADE, SEVERAL METHODS HAVE BEEN APPLIED TO CHARACTERIZE DNA METHYLATION-SPECIFIC LOCI OF CONNEXIN GENES. THIS CHAPTER DESCRIBES ANALYSIS OF SELECTIVE CONNEXIN32 AND CONNEXIN43 GENE DNA METHYLATION IN HUMAN GASTRIC TISSUES USING METHYLATION-SPECIFIC PCR, BISULFITE-SPECIFIC PCR SEQUENCING AS WELL AS MASSARRAY TECHNIQUES. 2016 9 5239 26 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 10 5057 14 PHENOBARBITAL MECHANISTIC DATA AND RISK ASSESSMENT: ENZYME INDUCTION, ENHANCED CELL PROLIFERATION, AND TUMOR PROMOTION. CHRONIC EXPOSURE TO HIGH DOSES OF PHENOBARBITAL (PB) CAUSES HEPATOCELLULAR ADENOMAS IN BOTH MICE AND RATS AND HEPATOCELLULAR CARCINOMAS IN SOME STRAINS OF MICE. LONG-TERM PB THERAPY HAS NOT BEEN FOUND TO CAUSE HUMAN TUMORS. PB IS NOT DNA REACTIVE, AND MOST GENOTOXICITY TESTS HAVE YIELDED NEGATIVE RESULTS. PB HAS BEEN EXTENSIVELY STUDIED AS AN EPIGENETIC, RODENT LIVER TUMOR PROMOTER. AT EXPOSURES CAUSING RODENT LIVER TUMORS, PB HAS MEASURABLE EFFECTS ON HEPATOCYTES: PB INHIBITS CELL-TO-CELL COMMUNICATION; PB INDUCES ENZYMES, INCLUDING P450 CYTOCHROMES; PB STIMULATES PROLIFERATION AND INHIBITS APOPTOSIS OF HEPATOCYTES IN NEOPLASTIC FOCI. THRESHOLD EXPOSURES FOR SOME OF THESE ENDPOINTS COINCIDE WITH THE THRESHOLD EXPOSURE FOR TUMORIGENESIS. 1996 11 919 23 CHRONIC HYPOXIA DURING GESTATION CAUSES EPIGENETIC REPRESSION OF THE ESTROGEN RECEPTOR-ALPHA GENE IN OVINE UTERINE ARTERIES VIA HEIGHTENED PROMOTER METHYLATION. ESTROGEN RECEPTOR-ALPHA (ERALPHA) PLAYS A KEY ROLE IN THE ADAPTATION OF INCREASED UTERINE BLOOD FLOW IN PREGNANCY. CHRONIC HYPOXIA IS A COMMON STRESS TO MATERNAL CARDIOVASCULAR HOMEOSTASIS AND CAUSES INCREASED RISK OF PREECLAMPSIA. STUDIES IN PREGNANT SHEEP DEMONSTRATED THAT HYPOXIA DURING GESTATION DOWNREGULATED ERALPHA GENE EXPRESSION IN UTERINE ARTERIES. THE PRESENT STUDY TESTED THE HYPOTHESIS THAT HYPOXIA CAUSES EPIGENETIC REPRESSION OF THE ERALPHA GENE IN UTERINE ARTERIES VIA HEIGHTENED PROMOTER METHYLATION. OVINE ERALPHA PROMOTER OF 2035 BP SPANNING FROM -2000 TO +35 OF THE TRANSCRIPTION START SITE WAS CLONED. NO ESTROGEN OR HYPOXIA-INDUCIBLE FACTOR RESPONSE ELEMENTS WERE FOUND AT THE PROMOTER. TWO TRANSCRIPTION FACTOR BINDING SITES, USF(-15) AND SP1(-520), CONTAINING CPG DINUCLEOTIDES WERE IDENTIFIED, WHICH HAD SIGNIFICANT EFFECTS ON THE PROMOTER ACTIVITY. THE USF ELEMENT BINDS TRANSCRIPTION FACTORS USF1 AND USF2, AND THE SP1 ELEMENT BINDS SP1, AS WELL AS ERALPHA THROUGH SP1. DELETION OF THE SP1 SITE ABROGATED 17BETA-ESTRADIOL-INDUCED INCREASE IN THE PROMOTER ACTIVITY. IN NORMOXIC CONTROL SHEEP, CPG METHYLATION AT THE SP1 BUT NOT THE USF SITE WAS SIGNIFICANTLY DECREASED IN UTERINE ARTERIES OF PREGNANT AS COMPARED WITH NONPREGNANT ANIMALS. IN PREGNANT SHEEP EXPOSED TO LONG-TERM HIGH-ALTITUDE HYPOXIA, CPG METHYLATION AT BOTH SP1 AND USF SITES IN UTERINE ARTERIES WAS SIGNIFICANTLY INCREASED. METHYLATION INHIBITED TRANSCRIPTION FACTOR BINDING AND THE PROMOTER ACTIVITY. THE RESULTS PROVIDE EVIDENCE OF HYPOXIA CAUSING HEIGHTENED PROMOTER METHYLATION AND RESULTANT ERALPHA GENE REPRESSION IN UTERINE ARTERIES AND SUGGEST NEW INSIGHTS OF MOLECULAR MECHANISMS LINKING GESTATIONAL HYPOXIA TO ABERRANT UTEROPLACENTAL CIRCULATION AND INCREASED RISK OF PREECLAMPSIA. 2012 12 4310 28 MICRORNAS AND PROGESTERONE RECEPTOR SIGNALING IN ENDOMETRIOSIS PATHOPHYSIOLOGY. ENDOMETRIOSIS IS A SIGNIFICANT DISEASE CHARACTERIZED BY INFERTILITY AND PELVIC PAIN IN WHICH ENDOMETRIAL STROMAL AND GLANDULAR TISSUE GROW IN ECTOPIC LOCATIONS. ALTERED RESPONSIVENESS TO PROGESTERONE IS A CONTRIBUTING FACTOR TO ENDOMETRIOSIS PATHOPHYSIOLOGY, BUT THE PRECISE MECHANISMS ARE POORLY UNDERSTOOD. PROGESTERONE RESISTANCE INFLUENCES BOTH THE EUTOPIC AND ECTOPIC (ENDOMETRIOTIC LESION) ENDOMETRIUM. AN INABILITY OF THE EUTOPIC ENDOMETRIUM TO PROPERLY RESPOND TO PROGESTERONE IS BELIEVED TO CONTRIBUTE TO THE INFERTILITY ASSOCIATED WITH THE DISEASE, WHILE AN ALTERED RESPONSIVENESS OF ENDOMETRIOTIC LESION TISSUE MAY CONTRIBUTE TO THE SURVIVAL OF THE ECTOPIC TISSUE AND ASSOCIATED SYMPTOMS. WOMEN WITH ENDOMETRIOSIS EXPRESS ALTERED LEVELS OF SEVERAL ENDOMETRIAL PROGESTERONE TARGET GENES WHICH MAY BE DUE TO THE ABNORMAL EXPRESSION AND/OR FUNCTION OF PROGESTERONE RECEPTORS AND/OR CHAPERONE PROTEINS, AS WELL AS INFLAMMATION, GENETICS, AND EPIGENETICS. MIRNAS ARE A CLASS OF EPIGENETIC MODULATORS PROPOSED TO PLAY A ROLE IN ENDOMETRIOSIS PATHOPHYSIOLOGY, INCLUDING THE MODULATION OF PROGESTERONE SIGNALING. IN THIS PAPER, WE SUMMARIZE THE ROLE OF PROGESTERONE RECEPTORS AND PROGESTERONE SIGNALING IN ENDOMETRIOSIS PATHOPHYSIOLOGY, REVIEW MIRNAS, WHICH ARE OVER-EXPRESSED IN ENDOMETRIOSIS TISSUES AND FLUIDS, AND FOLLOW THIS WITH A DISCUSSION ON THE POTENTIAL REGULATION OF KEY PROGESTERONE SIGNALING COMPONENTS BY THESE MIRNAS, CONCLUDING WITH SUGGESTIONS FOR FUTURE RESEARCH ENDEAVORS IN THIS AREA. 2022 13 2480 21 EPIGENETIC UPREGULATION OF LARGE-CONDUCTANCE CA2+-ACTIVATED K+ CHANNEL EXPRESSION IN UTERINE VASCULAR ADAPTATION TO PREGNANCY. OUR PREVIOUS STUDY DEMONSTRATED THAT PREGNANCY INCREASED LARGE-CONDUCTANCE CA(2+)-ACTIVATED POTASSIUM CHANNEL BETA1 SUBUNIT (BKBETA1) EXPRESSION AND LARGE-CONDUCTANCE CA(2+)-ACTIVATED POTASSIUM CHANNEL ACTIVITY IN UTERINE ARTERIES, WHICH WERE ABROGATED BY CHRONIC HYPOXIA. THE PRESENT STUDY TESTED THE HYPOTHESIS THAT PROMOTER METHYLATION/DEMETHYLATION IS A KEY MECHANISM IN EPIGENETIC REPROGRAMMING OF BKBETA1 EXPRESSION PATTERNS IN UTERINE ARTERIES. OVINE BKBETA1 PROMOTER OF 2315 BP SPANNING FROM -2211 TO +104 OF THE TRANSCRIPTION START SITE WAS CLONED, AND AN SP1-380 BINDING SITE THAT CONTAINS CPG DINUCLEOTIDE IN ITS CORE BINDING SEQUENCES WAS IDENTIFIED. SITE-DIRECTED DELETION OF THE SP1 SITE SIGNIFICANTLY DECREASED THE BKBETA1 PROMOTER ACTIVITY. ESTROGEN RECEPTOR-ALPHA BOUND TO THE SP1 SITE THROUGH TETHERING TO SP1 AND UPREGULATED THE EXPRESSION OF BKBETA1. THE SP1 BINDING SITE AT BKBETA1 PROMOTER WAS HIGHLY METHYLATED IN UTERINE ARTERIES OF NONPREGNANT SHEEP, AND METHYLATION INHIBITED TRANSCRIPTION FACTOR BINDING AND BKBETA1 PROMOTER ACTIVITY. PREGNANCY CAUSED A SIGNIFICANT DECREASE IN CPG METHYLATION AT THE SP1 BINDING SITE AND INCREASED SP1 BINDING TO THE BKBETA1 PROMOTER AND BKBETA1 MRNA ABUNDANCE. CHRONIC HYPOXIA DURING GESTATION ABROGATED THIS PREGNANCY-INDUCED DEMETHYLATION AND UPREGULATION OF BKBETA1 EXPRESSION. THE RESULTS PROVIDE EVIDENCE OF A NOVEL MECHANISM OF PROMOTER DEMETHYLATION IN PREGNANCY-INDUCED REPROGRAMMING OF LARGE-CONDUCTANCE CA(2+)-ACTIVATED POTASSIUM CHANNEL EXPRESSION AND FUNCTION IN UTERINE ARTERIES AND SUGGEST NEW INSIGHTS OF EPIGENETIC MECHANISMS LINKING GESTATIONAL HYPOXIA TO ABERRANT UTEROPLACENTAL CIRCULATION AND INCREASED RISK OF PREECLAMPSIA. 2014 14 1891 28 ENDOMETRIOSIS. PELVIC ENDOMETRIOSIS IS A COMPLEX SYNDROME CHARACTERIZED BY AN ESTROGEN-DEPENDENT CHRONIC INFLAMMATORY PROCESS THAT AFFECTS PRIMARILY PELVIC TISSUES, INCLUDING THE OVARIES. IT IS CAUSED WHEN SHED ENDOMETRIAL TISSUE TRAVELS RETROGRADE INTO THE LOWER ABDOMINAL CAVITY. ENDOMETRIOSIS IS THE MOST COMMON CAUSE OF CHRONIC PELVIC PAIN IN WOMEN AND IS ASSOCIATED WITH INFERTILITY. THE UNDERLYING PATHOLOGIC MECHANISMS IN THE INTRACAVITARY ENDOMETRIUM AND EXTRAUTERINE ENDOMETRIOTIC TISSUE INVOLVE DEFECTIVELY PROGRAMMED ENDOMETRIAL MESENCHYMAL PROGENITOR/STEM CELLS. ALTHOUGH ENDOMETRIOTIC STROMAL CELLS, WHICH COMPOSE THE BULK OF ENDOMETRIOTIC LESIONS, DO NOT CARRY SOMATIC MUTATIONS, THEY DEMONSTRATE SPECIFIC EPIGENETIC ABNORMALITIES THAT ALTER EXPRESSION OF KEY TRANSCRIPTION FACTORS. FOR EXAMPLE, GATA-BINDING FACTOR-6 OVEREXPRESSION TRANSFORMS AN ENDOMETRIAL STROMAL CELL TO AN ENDOMETRIOTIC PHENOTYPE, AND STEROIDOGENIC FACTOR-1 OVEREXPRESSION CAUSES EXCESSIVE PRODUCTION OF ESTROGEN, WHICH DRIVES INFLAMMATION VIA PATHOLOGICALLY HIGH LEVELS OF ESTROGEN RECEPTOR-BETA. PROGESTERONE RECEPTOR DEFICIENCY CAUSES PROGESTERONE RESISTANCE. POPULATIONS OF ENDOMETRIAL AND ENDOMETRIOTIC EPITHELIAL CELLS ALSO HARBOR MULTIPLE CANCER DRIVER MUTATIONS, SUCH AS KRAS, WHICH MAY BE ASSOCIATED WITH THE ESTABLISHMENT OF PELVIC ENDOMETRIOSIS OR OVARIAN CANCER. IT IS NOT KNOWN HOW INTERACTIONS BETWEEN EPIGENOMICALLY DEFECTIVE STROMAL CELLS AND THE MUTATED GENES IN EPITHELIAL CELLS CONTRIBUTE TO THE PATHOGENESIS OF ENDOMETRIOSIS. ENDOMETRIOSIS-ASSOCIATED PELVIC PAIN IS MANAGED BY SUPPRESSION OF OVULATORY MENSES AND ESTROGEN PRODUCTION, CYCLOOXYGENASE INHIBITORS, AND SURGICAL REMOVAL OF PELVIC LESIONS, AND IN VITRO FERTILIZATION IS FREQUENTLY USED TO OVERCOME INFERTILITY. ALTHOUGH NOVEL TARGETED TREATMENTS ARE BECOMING AVAILABLE, AS ENDOMETRIOSIS PATHOPHYSIOLOGY IS BETTER UNDERSTOOD, PREVENTIVE APPROACHES SUCH AS LONG-TERM OVULATION SUPPRESSION MAY PLAY A CRITICAL ROLE IN THE FUTURE. 2019 15 5241 28 PROGESTERONE RESISTANCE IN ENDOMETRIOSIS: CURRENT EVIDENCE AND PUTATIVE MECHANISMS. ENDOMETRIOSIS IS AN ESTROGEN-DEPENDENT DISEASE CHARACTERIZED BY THE GROWTH OF ENDOMETRIAL-LIKE TISSUE OUTSIDE THE UTERUS. PROGESTINS ARE CURRENTLY THE MOST COMMONLY USED TREATMENT FOR ENDOMETRIOSIS BECAUSE OF THEIR EXCELLENT THERAPEUTIC EFFECTS AND LIMITED SIDE EFFECTS. HOWEVER, PROGESTINS HAVE BEEN UNSUCCESSFUL IN SOME SYMPTOMATIC PATIENTS. THE INABILITY OF THE ENDOMETRIUM TO RESPOND PROPERLY TO PROGESTERONE IS KNOWN AS PROGESTERONE RESISTANCE. AN INCREASING BODY OF EVIDENCE SUGGESTS THE LOSS OF PROGESTERONE SIGNALING AND THE EXISTENCE OF PROGESTERONE RESISTANCE IN ENDOMETRIOSIS. THE MECHANISMS OF PROGESTERONE RESISTANCE HAVE RECEIVED CONSIDERABLE SCHOLARLY ATTENTION IN RECENT YEARS. ABNORMAL PGR SIGNALING, CHRONIC INFLAMMATION, ABERRANT GENE EXPRESSION, EPIGENETIC ALTERATIONS, AND ENVIRONMENTAL TOXINS ARE CONSIDERED POTENTIAL MOLECULAR CAUSES OF PROGESTERONE RESISTANCE IN ENDOMETRIOSIS. THE GENERAL OBJECTIVE OF THIS REVIEW WAS TO SUMMARIZE THE EVIDENCE AND MECHANISMS OF PROGESTERONE RESISTANCE. A DEEPER UNDERSTANDING OF HOW THESE MECHANISMS CONTRIBUTE TO PROGESTERONE RESISTANCE MAY HELP DEVELOP A NOVEL THERAPEUTIC REGIMEN FOR WOMEN WITH ENDOMETRIOSIS BY REVERSING PROGESTERONE RESISTANCE. 2023 16 898 32 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 17 2575 25 EPIGENETICS OF ESTROGEN AND PROGESTERONE RECEPTORS IN ENDOMETRIOSIS. ENDOMETRIOSIS IS AN ESTROGEN-DEPENDENT INFLAMMATORY GYNECOLOGICAL DISEASE. INCREASED ESTROGEN ACTIVITY AND PROGESTERONE RESISTANCE ARE THE MAIN HORMONAL SUBSTRATE OF THIS DISEASE AND ARE ASSOCIATED WITH INFLAMMATORY RESPONSE AND DEBILITATING SYMPTOMS, INCLUDING PAIN AND INFERTILITY. ESTROGENS AND PROGESTERONE ACT VIA THEIR SPECIFIC NUCLEAR RECEPTORS. THE REGULATION OF RECEPTOR EXPRESSION BY EPIGENETICS MAYBE A CRITICAL FACTOR FOR ENDOMETRIOSIS. THE PRESENT REVIEW AIMS TO DISCUSS THE EPIGENETIC MECHANISMS RELATED TO THE EXPRESSION OF ESTROGEN RECEPTORS (ERS) AND PROGESTERONE RECEPTORS (PRS) IN PATIENTS WITH ENDOMETRIOSIS, INCLUDING TWO CLASSIC EPIGENETIC MECHANISMS: DNA METHYLATION AND HISTONE MODIFICATION, AND, OTHER NON-CLASSIC MECHANISMS: MIRNAS AND LNCRNA. SEVERAL IN VITRO AND IN VIVO STUDIES SUPPORT THE KEY ROLE OF EPIGENETICS IN THE REGULATION OF THE EXPRESSION OF ERS AND PRS, WHICH MAY PROVIDE NEW MOLECULES AND TARGETS FOR THE DIAGNOSIS AND TREATMENT OF ENDOMETRIOSIS. 2020 18 651 21 BISPHENOL A AND PHTHALATES MODULATE PERITONEAL MACROPHAGE FUNCTION IN FEMALE MICE INVOLVING SYMD2-H3K36 DIMETHYLATION. AMPLE EVIDENCE SUGGESTS THAT ENVIRONMENTAL AND OCCUPATIONAL EXPOSURE TO BISPHENOL A (BPA) AND PHTHALATE, TWO CHEMICALS WIDELY USED IN THE PLASTICS INDUSTRY, DISTURBS HOMEOSTASIS OF INNATE IMMUNITY AND CAUSES INFLAMMATORY DISEASES. HOWEVER, THE UNDERLYING MOLECULAR MECHANISMS OF THESE TOXICANTS IN THE REGULATION OF MACROPHAGE INFLAMMATORY FUNCTIONS REMAIN POORLY UNDERSTOOD. IN THIS STUDY, WE ADDRESSED THE EFFECT OF CHRONIC EXPOSURE TO BPA OR PHTHALATE AT LEVELS RELEVANT TO HUMAN EXPOSURE, EITHER IN VITRO OR IN VIVO, ON THE INFLAMMATORY REPROGRAMING OF PERITONEAL MACROPHAGES. OUR STUDIES REVEALED THAT BPA AND PHTHALATES ADVERSELY AFFECTED EXPRESSION LEVELS OF THE PROINFLAMMATORY CYTOKINES AND MEDIATORS IN RESPONSE TO LIPOPOLYSACCHARIDE STIMULATION. EXPOSURE TO THESE TOXICANTS ALSO AFFECTED GENE EXPRESSION OF SCAVENGER RECEPTORS AND PHAGOCYTIC CAPACITY OF PERITONEAL MACROPHAGES. OUR STUDIES REVEALED THAT THE EPIGENETIC INHIBITORS DIFFERENTIALLY MODULATED TARGET GENE EXPRESSION IN THESE CELLS. FURTHER ANALYSIS REVEALED THAT CERTAIN HISTONE MODIFICATION ENZYMES WERE ABERRANTLY EXPRESSED IN RESPONSE TO BPA OR PHTHALATE EXPOSURE, LEADING TO ALTERATION IN THE LEVELS OF H3K36 ACETYLATION AND DIMETHYLATION, TWO CHROMATIN MODIFICATIONS THAT ARE CRITICAL FOR TRANSCRIPTIONAL EFFICACY AND ACCURACY. OUR RESULTS FURTHER REVEALED THAT SILENCING OF H3K36-SPECIFIC METHYLTRANSFERASE SMYD2 EXPRESSION OR INHIBITION OF SMYD2 ENZYMATIC ACTIVITY ATTENUATED H3K36 DIMETHYLATION AND ENHANCED INTERLEUKIN-6 AND TUMOR NECROSIS FACTOR-ALPHA EXPRESSION BUT DAMPENED THE PHAGOCYTIC CAPACITY OF PERITONEAL MACROPHAGES. IN SUMMARY, OUR RESULTS INDICATE THAT PERITONEAL MACROPHAGES ARE VULNERABLE TO BPA OR PHTHALATE AT LEVELS RELEVANT TO HUMAN EXPOSURE. THESE ENVIRONMENTAL TOXICANTS AFFECT PHENOTYPIC PROGRAMMING OF MACROPHAGES VIA EPIGENETIC MECHANISMS INVOLVING SMYD2-MEDIATED H3K36 MODIFICATION. 2018 19 2101 26 EPIGENETIC EFFECTS OF PRENATAL STRESS ON 11BETA-HYDROXYSTEROID DEHYDROGENASE-2 IN THE PLACENTA AND FETAL BRAIN. MATERNAL EXPOSURE TO STRESS DURING PREGNANCY IS ASSOCIATED WITH SIGNIFICANT ALTERATIONS IN OFFSPRING NEURODEVELOPMENT AND ELEVATED MATERNAL GLUCOCORTICOIDS LIKELY PLAY A CENTRAL ROLE IN MEDIATING THESE EFFECTS. PLACENTAL 11BETA-HYDROXYSTEROID DEHYDROGENASE TYPE 2 (HSD11B2) BUFFERS THE IMPACT OF MATERNAL GLUCOCORTICOID EXPOSURE BY CONVERTING CORTISOL/CORTICOSTERONE INTO INACTIVE METABOLITES. HOWEVER, PREVIOUS STUDIES INDICATE THAT MATERNAL ADVERSITY DURING THE PRENATAL PERIOD CAN LEAD TO A DOWN-REGULATION OF THIS ENZYME. IN THE CURRENT STUDY, WE EXAMINED THE IMPACT OF PRENATAL STRESS (CHRONIC RESTRAINT STRESS DURING GESTATIONAL DAYS 14-20) IN LONG EVANS RATS ON HSD11B2 MRNA IN THE PLACENTA AND FETAL BRAIN (E20) AND ASSESSED THE ROLE OF EPIGENETIC MECHANISMS IN THESE STRESS-INDUCED EFFECTS. IN THE PLACENTA, PRENATAL STRESS WAS ASSOCIATED WITH A SIGNIFICANT DECREASE IN HSD11B2 MRNA, INCREASED MRNA LEVELS OF THE DNA METHYLTRANSFERASE DNMT3A, AND INCREASED DNA METHYLATION AT SPECIFIC CPG SITES WITHIN THE HSD11B2 GENE PROMOTER. WITHIN THE FETAL HYPOTHALAMUS, THOUGH WE FIND NO STRESS-INDUCED EFFECTS ON HSD11B2 MRNA LEVELS, PRENATAL STRESS INDUCED DECREASED CPG METHYLATION WITHIN THE HSD11B2 PROMOTER AND INCREASED METHYLATION AT SITES WITHIN EXON 1. WITHIN THE FETAL CORTEX, HSD11B2 MRNA AND DNA METHYLATION LEVELS WERE NOT ALTERED BY PRENATAL STRESS, THOUGH WE DID FIND STRESS-INDUCED ELEVATIONS IN DNMT1 MRNA IN THIS BRAIN REGION. WITHIN INDIVIDUALS, WE IDENTIFIED CPG SITES WITHIN THE HSD11B2 GENE PROMOTER AND EXON 1 AT WHICH DNA METHYLATION LEVELS WERE HIGHLY CORRELATED BETWEEN THE PLACENTA AND FETAL CORTEX. OVERALL, OUR FINDINGS IMPLICATE DNA METHYLATION AS A MECHANISM BY WHICH PRENATAL STRESS ALTERS HSD11B2 GENE EXPRESSION. THESE FINDINGS HIGHLIGHT THE TISSUE SPECIFICITY OF EPIGENETIC EFFECTS, BUT ALSO RAISE THE INTRIGUING POSSIBILITY OF USING THE EPIGENETIC STATUS OF PLACENTA TO PREDICT CORRESPONDING CHANGES IN THE BRAIN. 2012 20 2602 33 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