1 5753 140 SOCIAL ISOLATION REDUCES MAMMARY DEVELOPMENT, TUMOR INCIDENCE, AND EXPRESSION OF EPIGENETIC REGULATORS IN WILD-TYPE AND P53-HETEROZYGOTIC MICE. CHRONIC STRESS IS ASSOCIATED WITH MORE RAPID TUMOR PROGRESSION, AND RECENT EVIDENCE SUGGESTS THAT STRESS MAY CONTRIBUTE TO SOCIAL AND ETHNIC DISPARITIES IN THE INCIDENCE AND MORTALITY OF BREAST CANCER. WE EVALUATED THE P53(+/-) FVB/N MOUSE AS A MODEL TO INVESTIGATE EFFECTS OF CHRONIC SOCIAL STRESS ON MAMMARY GLAND DEVELOPMENT, GENE EXPRESSION, AND TUMORIGENESIS. WE INDIVIDUALLY HOUSED (IH) WILD-TYPE AND P53(+/-) FEMALE FVB/N MICE, STARTING AT WEANING. AT 14 WEEKS OF AGE, BOTH WILD-TYPE AND P53(+/-) IH MICE SHOWED STRIKINGLY REDUCED MAMMARY DEVELOPMENT COMPARED WITH GROUP-HOUSED (GH) CONTROLS, WITH IH MICE HAVING SIGNIFICANTLY FEWER PRETERMINAL END BUDS. THIS MORPHOLOGIC DIFFERENCE WAS NOT REFLECTED IN LEVELS OF MAMMARY TRANSCRIPTS FOR ESTROGEN RECEPTOR-ALPHA OR PROGESTIN RECEPTOR. HOWEVER, IH INCREASED LEVELS OF MRNA FOR THE KISSPEPTIN RECEPTOR IN THE MEDIAL PREOPTIC AREA OF THE HYPOTHALAMUS, ASSOCIATED WITH REDUCED DURATION OF ESTROUS CYCLES. FURTHERMORE, IH ALTERED MAMMARY TRANSCRIPTS OF GENES ASSOCIATED WITH DNA METHYLATION; TRANSCRIPTS FOR METHYL-BINDING PROTEIN 2 AND DNA METHYLTRANSFERASE 3B (DNMT3B), BUT NOT DNMT1 AND DNMT3A, WERE REDUCED IN IH COMPARED WITH GH FEMALES. INTERESTINGLY, THE GLANDS OF P53(+/-) FEMALES SHOWED REDUCED EXPRESSION OF ALL THESE MEDIATORS COMPARED WITH WILD-TYPE FEMALES. HOWEVER, CONTRARY TO OUR INITIAL HYPOTHESIS, IH DID NOT INCREASE MAMMARY TUMORIGENESIS. RATHER, P53(+/-) GH FEMALES DEVELOPED SIGNIFICANTLY MORE MAMMARY TUMORS THAN IH MICE. TOGETHER, THESE DATA SUGGEST THAT SOCIAL ISOLATION INITIATED AT PUBERTY MIGHT CONFOUND STUDIES OF TUMORIGENESIS BY ALTERING MAMMARY DEVELOPMENT IN MOUSE MODELS. 2010 2 1418 40 DIFFERENCES IN DNA METHYLATION REPROGRAMMING UNDERLIE THE SEXUAL DIMORPHISM OF BEHAVIORAL DISORDER CAUSED BY PRENATAL STRESS IN RATS. PRENATAL STRESS (PS) CAN LEAD TO NEUROENDOCRINE AND EMOTIONAL DISORDERS LATER IN ADOLESCENCE. SEXUAL DIMORPHISM IN THESE NEURODEVELOPMENTAL OUTCOMES HAVE BEEN OBSERVED; HOWEVER, THE UNDERLYING MECHANISMS ARE NOT FULLY UNDERSTOOD. TO ADDRESS THIS ISSUE, WE INVESTIGATED WHETHER THERE ARE SEX DIFFERENCES IN EPIGENETIC REPROGRAMMING IN RATS EXPOSED TO PS. PREGNANT FEMALE RATS WERE SUBJECTED TO CHRONIC RESTRAINT STRESS FROM GESTATIONAL DAY (G)12 TO G18. FROM POSTNATAL DAY (P)38 TO P45, SUBGROUPS OF OFFSPRING INCLUDING BOTH MALES AND FEMALES WERE SUBJECTED TO BEHAVIORAL TESTING AND BRAIN TISSUE SPECIMENS WERE ANALYZED BY DNA PYROSEQUENCING, WESTERN BLOTTING, AND GOLGI STAINING TO ASSESS CHANGES IN METHYLATION PATTERN OF GLUCOCORTICOID RECEPTOR (GR) GENE, EXPRESSION OF DNA METHYLTRANSFERASE (DNMT) AND DNA DEMETHYLASE, AND DENDRITE MORPHOLOGY, RESPECTIVELY. THE DNA METHYLTRANSFERASE INHIBITOR DECITABINE WAS ADMINISTERED TO RATS PRIOR TO PS TO FURTHER EVALUATE THE ROLE OF METHYLATION IN THE SEXUALLY DIMORPHIC EFFECTS OF PS. THE RESULTS SHOWED THAT PS INCREASED ANXIETY-LIKE BEHAVIOR IN OFFSPRING, ESPECIALLY IN FEMALES, WHILE DEPRESSION-LIKE BEHAVIOR WAS INCREASED IN MALE OFFSPRING COMPARED TO CONTROL LITTERMATES. THE METHYLATION PATTERN IN THE PROMOTER REGION OF THE GR GENE DIFFERED BETWEEN MALES AND FEMALES. SEX-SPECIFIC CHANGES IN THE EXPRESSION OF DNMTS (DNMT1 AND DNMT3A) AND DNA DEMETHYLASE (TET METHYLCYTOSINE DIOXYGENASE 2) WERE ALSO OBSERVED. INTERESTINGLY, DECITABINE ALLEVIATED THE BEHAVIORAL DISORDER CAUSED BY PS AND RESTORED DENDRITE DENSITY AND MORPHOLOGY IN FEMALE BUT NOT MALE RATS. THESE FINDINGS SUGGEST THAT DIFFERENT CHANGE PATTERNS OF DNMT AND DEMETHYLASE IN THE TWO SEXES AFTER PS ARE RESPONSIBLE FOR THE SEXUALLY DIMORPHISM, WHICH COULD HAVE IMPLICATIONS FOR THE CLINICAL MANAGEMENT OF STRESS-RELATED DISORDERS. 2020 3 2297 38 EPIGENETIC REGULATION OF ACUTE INFLAMMATORY PAIN. ACUTE PAIN IS ASSOCIATED WITH TISSUE DAMAGE, WHICH RESULTS IN THE RELEASE OF INFLAMMATORY MEDIATORS. RECENT STUDIES POINT TO THE INVOLVEMENT OF EPIGENETIC MECHANISMS (DNA METHYLATION) IN THE DEVELOPMENT OF PAIN. WE HAVE FOUND THAT DURING ACUTE INFLAMMATORY PAIN INDUCED BY THE APPLICATION OF 10% MUSTARD OIL ON THE TONGUES OF RATS, LEVELS OF DNMT3A AND 3B WERE ELEVATED MARKEDLY (36 AND 42 % RESPECTIVELY), WHEREAS THE LEVEL OF DNMT1 WAS NOT CHANGED SIGNIFICANTLY. PREVIOUS INJECTION OF XEFOCAM WITH 0,4 MG/KG DOSE DECREASED LEVELS OF DNMT3A AND 3B (25 AND 24% RESPECTIVELY). THE LEVEL OF DNMT1 WAS NOT CHANGED SIGNIFICANTLY COMPARED TO THE CONTROL GROUP. THE FINDINGS SUPPORT THE IDEA THAT INHIBITORS OF DNA-METHYLTRANSFERASES COULD BE USEFUL FOR PAIN MANAGEMENT. OUR DATA SUGGEST THAT NSAIDS (ALONE OR IN COMBINATION WITH DNMT INHIBITORS) MAY BE PROPOSED AS POSSIBLE EPIGENETIC REGULATORY AGENTS, WHICH MAY PLAY A ROLE IN EPIGENETIC MECHANISMS INDIRECTLY THROUGH ALTERING THE ACTIVITY OF INFLAMMATORY MEDIATORS INVOLVED IN PAIN DEVELOPMENT. 2014 4 4224 37 METHYLATION CHANGES IN MUSCLE AND LIVER TISSUES OF MALE AND FEMALE MICE EXPOSED TO ACUTE AND CHRONIC LOW-DOSE X-RAY-IRRADIATION. THE BIOLOGICAL AND GENETIC EFFECTS OF CHRONIC LOW-DOSE RADIATION (LDR) EXPOSURE AND ITS RELATIONSHIP TO CARCINOGENESIS HAVE RECEIVED A LOT OF ATTENTION IN THE RECENT YEARS. FOR EXAMPLE, RADIATION-INDUCED GENOME INSTABILITY, WHICH IS THOUGHT TO BE A PRECURSOR OF TUMOROGENESIS, WAS SHOWN TO HAVE A TRANSGENERATIONAL NATURE. THIS INDICATES A POSSIBLE INVOLVEMENT OF EPIGENETIC MECHANISMS IN LDR-INDUCED GENOME INSTABILITY. GENOMIC DNA METHYLATION IS ONE OF THE MOST IMPORTANT EPIGENETIC MECHANISMS. EXISTING DATA ON RADIATION EFFECTS ON DNA METHYLATION PATTERNS IS LIMITED, AND NO ONE HAS SPECIFICALLY STUDIED THE EFFECTS OF THE LDR. WE REPORT THE FIRST STUDY OF THE EFFECTS OF WHOLE-BODY LDR EXPOSURE ON GLOBAL GENOME METHYLATION IN MUSCLE AND LIVER TISSUES OF MALE AND FEMALE MICE. IN PARALLEL, WE EVALUATED CHANGES IN PROMOTER METHYLATION AND EXPRESSION OF THE TUMOR SUPPRESSOR GENE P16(INKA) AND DNA REPAIR GENE O(6)-METHYLGUANINE-DNA METHYLTRANSFERASE (MGMT). WE OBSERVED DIFFERENT PATTERNS OF RADIATION-INDUCED GLOBAL GENOME DNA METHYLATION IN THE LIVER AND MUSCLE OF EXPOSED MALES AND FEMALES. WE ALSO FOUND SEX AND TISSUE-SPECIFIC DIFFERENCES IN P16(INKA) PROMOTER METHYLATION UPON LDR EXPOSURE. IN MALE LIVER TISSUE, P16(INKA) PROMOTER METHYLATION WAS MORE PRONOUNCED THAN IN FEMALE TISSUE. IN CONTRAST, NO SIGNIFICANT RADIATION-INDUCED CHANGES IN P16(INKA) PROMOTER METHYLATION WERE NOTED IN THE MUSCLE TISSUE OF EXPOSED MALES AND FEMALES. RADIATION ALSO DID NOT SIGNIFICANTLY AFFECT METHYLATION STATUS OF MGMT PROMOTER. WE ALSO OBSERVED SUBSTANTIAL SEX DIFFERENCES IN ACUTE AND CHRONIC RADIATION-INDUCED EXPRESSION OF P16(INKA) AND MGMT GENES. ANOTHER IMPORTANT OUTCOME OF OUR STUDY WAS THE FACT THAT CHRONIC LOW-DOSE RADIATION EXPOSURE PROVED TO BE A MORE POTENT INDUCER OF EPIGENETIC EFFECTS THAN THE ACUTE EXPOSURE. THIS SUPPORTS PREVIOUS FINDINGS THAT CHRONIC EXPOSURE LEADS TO GREATER GENOME DESTABILIZATION THAN ACUTE EXPOSURE. 2004 5 978 43 CHRONIC OXIDATIVE STRESS CAUSES ESTROGEN-INDEPENDENT AGGRESSIVE PHENOTYPE, AND EPIGENETIC INACTIVATION OF ESTROGEN RECEPTOR ALPHA IN MCF-7 BREAST CANCER CELLS. THE ROLE OF CHRONIC OXIDATIVE STRESS IN THE DEVELOPMENT AND AGGRESSIVE GROWTH OF ESTROGEN RECEPTOR (ER)-POSITIVE BREAST CANCER IS WELL KNOWN; HOWEVER, THE MECHANISTIC UNDERSTANDING IS NOT CLEAR. ESTROGEN-INDEPENDENT GROWTH IS ONE OF THE FEATURES OF AGGRESSIVE SUBTYPE OF BREAST CANCER. THEREFORE, THE OBJECTIVE OF THIS STUDY WAS TO EVALUATE THE EFFECT OF OXIDATIVE STRESS ON ESTROGEN SENSITIVITY AND EXPRESSION OF NUCLEAR ESTROGEN RECEPTORS IN ER-POSITIVE BREAST CANCER CELLS. MCF-7 CELLS CHRONICALLY EXPOSED TO HYDROGEN PEROXIDE WERE USED AS A CELL MODEL IN THIS STUDY, AND THEIR GROWTH IN RESPONSE TO 17-BETA ESTRADIOL WAS EVALUATED BY CELL VIABILITY, CELL CYCLE, AND CELL MIGRATION ANALYSIS. RESULTS WERE FURTHER CONFIRMED AT MOLECULAR LEVEL BY ANALYSIS OF GENE EXPRESSIONS AT TRANSCRIPT AND PROTEIN LEVELS. HISTONE H3 MODIFICATIONS, EXPRESSION OF EPIGENETIC REGULATORY GENES, AND THE EFFECT OF DNA DEMETHYLATION WERE ALSO ANALYZED. LOSS OF GROWTH IN RESPONSE TO ESTROGEN WITH A DECREASE IN ERALPHA EXPRESSION WAS OBSERVED IN MCF-7 CELLS ADAPTED TO CHRONIC OXIDATIVE STRESS. INCREASES IN MTTFA AND NRF1 IN THESE CELLS FURTHER SUGGESTED THE ROLE OF MITOCHONDRIA-DEPENDENT REDOX-SENSITIVE GROWTH SIGNALING AS AN ALTERNATIVE PATHWAY TO ESTROGEN-DEPENDENT GROWTH. CHANGES IN EXPRESSION OF EPIGENETIC REGULATORY GENES, LEVELS OF HISTONE H3 MODIFICATIONS AS WELL AS SIGNIFICANT RESTORATIONS OF BOTH ERALPHA EXPRESSION AND ESTROGEN RESPONSE BY 5-AZA-2'-DEOXYCYTIDINE FURTHER CONFIRMED THE EPIGENETIC BASIS FOR ESTROGEN-INDEPENDENT GROWTH IN THESE CELLS. IN CONCLUSION, RESULTS OF THIS STUDY SUGGEST THAT CHRONIC OXIDATIVE STRESS CAN CONVERT ESTROGEN-DEPENDENT NONAGGRESSIVE BREAST CANCER CELLS INTO ESTROGEN-INDEPENDENT AGGRESSIVE FORM POTENTIALLY BY EPIGENETIC MECHANISM. 2015 6 4093 36 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 7 990 37 CHRONIC SOCIAL STRESS INDUCES DNA METHYLATION CHANGES AT AN EVOLUTIONARY CONSERVED INTERGENIC REGION IN CHROMOSOME X. CHRONIC STRESS RESULTING FROM PROLONGED EXPOSURE TO NEGATIVE LIFE EVENTS INCREASES THE RISK OF MOOD AND ANXIETY DISORDERS. ALTHOUGH CHRONIC STRESS CAN CHANGE GENE EXPRESSION RELEVANT FOR BEHAVIOR, MOLECULAR REGULATORS OF THIS CHANGE HAVE NOT BEEN FULLY DETERMINED. ONE PROCESS THAT COULD PLAY A ROLE IS DNA METHYLATION, AN EPIGENETIC PROCESS WHEREBY A METHYL GROUP IS ADDED ONTO NUCLEOTIDES, PREDOMINANTLY CYTOSINE IN THE CPG CONTEXT, AND WHICH CAN BE INDUCED BY CHRONIC STRESS. IT IS UNKNOWN TO WHAT EXTENT CHRONIC SOCIAL DEFEAT, A MODEL OF HUMAN SOCIAL STRESS, INFLUENCES DNA METHYLATION PATTERNS ACROSS THE GENOME. OUR STUDY ADDRESSED THIS QUESTION BY USING A TARGETED-CAPTURE APPROACH CALLED METHYL-SEQ TO INVESTIGATE DNA METHYLATION PATTERNS OF THE DENTATE GYRUS AT PUTATIVE REGULATORY REGIONS ACROSS THE MOUSE GENOME FROM MICE EXPOSED TO 14 DAYS OF SOCIAL DEFEAT. FINDINGS WERE REPLICATED IN INDEPENDENT COHORTS BY BISULFITE-PYROSEQUENCING. TWO DIFFERENTIALLY METHYLATED REGIONS (DMRS) WERE IDENTIFIED. ONE DMR WAS LOCATED AT INTRON 9 OF DROSHA, AND IT SHOWED REDUCED METHYLATION IN STRESSED MICE. THIS OBSERVATION REPLICATED IN ONE OF TWO INDEPENDENT COHORTS. A SECOND DMR WAS IDENTIFIED AT AN INTERGENIC REGION OF CHROMOSOME X, AND METHYLATION IN THIS REGION WAS INCREASED IN STRESSED MICE. THIS METHYLATION DIFFERENCE REPLICATED IN TWO INDEPENDENT COHORTS AND IN MAJOR DEPRESSIVE DISORDER (MDD) POSTMORTEM BRAINS. THESE RESULTS HIGHLIGHT A REGION NOT PREVIOUSLY KNOWN TO BE DIFFERENTIALLY METHYLATED BY CHRONIC SOCIAL DEFEAT STRESS AND WHICH MAY BE INVOLVED IN MDD. 2018 8 4811 47 OBESITY-ASSOCIATED ALTERATIONS IN INFLAMMATION, EPIGENETICS, AND MAMMARY TUMOR GROWTH PERSIST IN FORMERLY OBESE MICE. USING A MURINE MODEL OF BASAL-LIKE BREAST CANCER, WE TESTED THE HYPOTHESIS THAT CHRONIC OBESITY, AN ESTABLISHED BREAST CANCER RISK AND PROGRESSION FACTOR IN WOMEN, INDUCES MAMMARY GLAND EPIGENETIC REPROGRAMMING AND INCREASES MAMMARY TUMOR GROWTH. MOREOVER, WE ASSESSED WHETHER THE OBESITY-INDUCED EPIGENETIC AND PROTUMOR EFFECTS ARE REVERSED BY WEIGHT NORMALIZATION. OVARIECTOMIZED FEMALE C57BL/6 MICE WERE FED A CONTROL DIET OR DIET-INDUCED OBESITY (DIO) REGIMEN FOR 17 WEEKS, RESULTING IN A NORMAL WEIGHT OR OBESE PHENOTYPE, RESPECTIVELY. MICE ON THE DIO REGIMEN WERE THEN RANDOMIZED TO CONTINUE THE DIO DIET OR WERE SWITCHED TO THE CONTROL DIET, RESULTING IN FORMERLY OBESE (FOB) MICE WITH WEIGHTS COMPARABLE WITH CONTROL MICE. AT WEEK 24, ALL MICE WERE ORTHOTOPICALLY INJECTED WITH MMTV-WNT-1 MOUSE MAMMARY TUMOR CELLS. MEAN TUMOR VOLUME, SERUM IL6 LEVELS, EXPRESSION OF PROINFLAMMATORY GENES IN THE MAMMARY FAT PAD, AND MAMMARY DNA METHYLATION PROFILES WERE SIMILAR IN DIO AND FOB MICE AND HIGHER THAN IN CONTROLS. MANY OF THE GENES FOUND TO HAVE OBESITY-ASSOCIATED HYPERMETHYLATION IN MICE WERE ALSO FOUND TO BE HYPERMETHYLATED IN THE NORMAL BREAST TISSUE OF OBESE VERSUS NONOBESE HUMAN SUBJECTS, AND NEARLY ALL OF THESE CONCORDANT GENES REMAINED HYPERMETHYLATED AFTER SIGNIFICANT WEIGHT LOSS IN THE FOB MICE. OUR FINDINGS SUGGEST THAT WEIGHT NORMALIZATION MAY NOT BE SUFFICIENT TO REVERSE THE EFFECTS OF CHRONIC OBESITY ON EPIGENETIC REPROGRAMMING AND INFLAMMATORY SIGNALS IN THE MICROENVIRONMENT THAT ARE ASSOCIATED WITH BREAST CANCER PROGRESSION. CANCER PREV RES; 9(5); 339-48. (C)2016 AACR. 2016 9 3714 39 INHERITANCE OF SOCIAL DOMINANCE IS ASSOCIATED WITH GLOBAL SPERM DNA METHYLATION IN INBRED MALE MICE. DOMINANCE RELATIONSHIPS BETWEEN MALES AND THEIR ASSOCIATED TRAITS ARE USUALLY HERITABLE AND HAVE IMPLICATIONS FOR SEXUAL SELECTION IN ANIMALS. IN PARTICULAR, SOCIAL DOMINANCE AND ITS RELATED MALE PHEROMONES ARE HERITABLE IN INBRED MICE; THUS, WE WONDERED WHETHER EPIGENETIC CHANGES DUE TO ALTERED LEVELS OF DNA METHYLATION DETERMINE INHERITANCE. HERE, WE USED C57BL/6 MALE MICE TO ESTABLISH A SOCIAL DOMINANCE-SUBORDINATION RELATIONSHIP THROUGH CHRONIC DYADIC ENCOUNTERS, AND THIS RELATIONSHIP AND PHEROMONE COVARIATION OCCURRED IN THEIR OFFSPRING, INDICATIVE OF HERITABILITY. THROUGH TRANSCRIPTOME SEQUENCING AND WHOLE-GENOME DNA METHYLATION PROFILING OF THE SPERM OF BOTH GENERATIONS, WE FOUND THAT DIFFERENTIAL METHYLATION OF MANY GENES WAS INDUCED BY SOCIAL DOMINANCE-SUBORDINATION IN SIRES AND COULD BE PASSED ON TO THE OFFSPRING. THESE METHYLATED GENES WERE MAINLY RELATED TO GROWTH AND DEVELOPMENT PROCESSES, NEURODEVELOPMENT, AND CELLULAR TRANSPORTATION. THE EXPRESSION OF THE GENES WITH SIMILAR FUNCTIONS IN WHOLE-GENOME METHYLATION/BISULFITE SEQUENCING WAS ALSO DIFFERENTIATED BY SOCIAL DOMINANCE-SUBORDINATION, AS REVEALED BY RNA-SEQ. IN PARTICULAR, THE GENE DENND1A, WHICH REGULATES NEURAL SIGNALING, WAS DIFFERENTIALLY METHYLATED AND EXPRESSED IN THE SPERM AND MEDIAL PREFRONTAL CORTEX IN PAIRED MALES BEFORE AND AFTER DOMINANCE-SUBORDINATION ESTABLISHMENT, SUGGESTING THE POTENTIAL EPIGENETIC CONTROL AND INHERITANCE OF SOCIAL DOMINANCE-RELATED AGGRESSION. WE SUGGEST THAT SOCIAL DOMINANCE MIGHT BE PASSED ON TO MALE OFFSPRING THROUGH SPERM DNA METHYLATION AND THAT THE DIFFERENCES COULD POTENTIALLY AFFECT MALE COMPETITION IN OFFSPRING BY AFFECTING THE DEVELOPMENT OF THE NERVOUS SYSTEM. 2023 10 920 29 CHRONIC HYPOXIA FACILITATES ALZHEIMER'S DISEASE THROUGH DEMETHYLATION OF GAMMA-SECRETASE BY DOWNREGULATING DNA METHYLTRANSFERASE 3B. INTRODUCTION: ENVIRONMENTAL FACTORS AND EPIGENETIC MECHANISMS ARE BELIEVED TO CONTRIBUTE TO ALZHEIMER'S DISEASE (AD). WE PREVIOUSLY DOCUMENTED THAT PRENATAL HYPOXIA AGGRAVATED THE COGNITIVE IMPAIRMENT AND NEUROPATHOLOGY IN OFFSPRING MICE. HERE, WE INVESTIGATE THE CHRONIC HYPOXIA-INDUCED EPIGENETIC MODIFICATIONS IN AD. METHODS: THE 3-MONTH-OLD APP(SWE)/PS1(DE9) MICE WERE EXPOSED TO HYPOXIC ENVIRONMENT 6 HOUR/DAY FOR 30 DAYS, FOLLOWED BY LEARNING AND MEMORY TESTS AND BIOCHEMICAL AND NEUROPATHOLOGY MEASUREMENT AT THE AGE OF 4, 6, AND 9 MONTHS. RESULTS: WE FOUND HYPOXIA EXAGGERATED THE NEUROPATHOLOGY AND COGNITIVE IMPAIRMENT IN AD MICE. CHRONIC HYPOXIA INDUCED DEMETHYLATION ON GENOMIC DNA AND DECREASED THE EXPRESSION OF DNA METHYLTRANSFERASE 3B (DNMT3B) IN VIVO. WE FURTHER FOUND THAT DNMTS INHIBITION ELEVATED THE PROTEIN LEVELS OF AMYLOID PRECURSOR PROTEIN, BETA- AND GAMMA-SECRETASES, WHEREAS OVEREXPRESSION OF DNMT3B SUPPRESSED THE LEVELS OF THEM IN VITRO. DISCUSSION: OUR STUDY SUGGESTS CHRONIC HYPOXIA CAN AGGRAVATE AD PROGRESSION THROUGH DEMETHYLATION OF GENES ENCODING GAMMA-SECRETASE COMPONENTS BY DOWNREGULATION OF DNMT3B. 2016 11 3981 39 LONG-TERM EPIGENETIC THERAPY WITH ORAL ZEBULARINE HAS MINIMAL SIDE EFFECTS AND PREVENTS INTESTINAL TUMORS IN MICE. RECENT SUCCESSES IN THE APPLICATION OF EPIGENETIC DRUGS FOR THE TREATMENT OF MYELODYSPLASTIC SYNDROME HAVE RAISED QUESTIONS ON THE SAFETY OF LONG-TERM ADMINISTRATION OF DNA METHYLATION INHIBITORS. WE TREATED PREWEANED CANCER PRONE APC(MIN/+) (MIN) MICE CONTINUOUSLY WITH THE DNA METHYLATION INHIBITOR ZEBULARINE IN THEIR DRINKING WATER TO DETERMINE THE EFFECTS OF THE DRUG ON NORMAL MOUSE DEVELOPMENT AS WELL AS CANCER PREVENTION. ZEBULARINE CAUSED A TISSUE-SPECIFIC REDUCTION IN DNA METHYLATION AT B1 SHORT INTERSPERSED NUCLEOTIDE ELEMENTS IN THE SMALL AND LARGE INTESTINES OF FEMALE MIN MICE BUT NOT IN OTHER ORGANS EXAMINED AFTER CHRONIC ORAL TREATMENT. NO SIGNIFICANT DIFFERENCE IN THE AVERAGE WEIGHTS OF MICE WAS OBSERVED DURING THE TREATMENT. IN ADDITION, ANALYSIS OF GLOBAL GENE EXPRESSION OF COLONIC EPITHELIAL CELLS FROM THE FEMALES INDICATED THAT ONLY 3% TO 6% OF THE GENES WERE AFFECTED IN THEIR EXPRESSION. WE DID NOT DETECT TOXICITY AND ABNORMALITIES FROM THE HISTOPATHOLOGIC ANALYSIS OF LIVER AND INTESTINAL TISSUES. LASTLY, WE TESTED WHETHER PREVENTION OF TUMORIGENESIS CAN BE ACHIEVED WITH CHRONIC ORAL ADMINISTRATION OF ZEBULARINE IN MIN MICE. THE AVERAGE NUMBER OF POLYPS IN MIN FEMALES DECREASED FROM 58 TO 1, WHEREAS THE AVERAGE POLYP NUMBER REMAINED UNAFFECTED IN MIN MALES POSSIBLY DUE TO DIFFERENTIAL ACTIVITY OF ALDEHYDE OXIDASE. TAKEN TOGETHER, OUR RESULTS SHOW FOR THE FIRST TIME THAT LONG-TERM ORAL ADMINISTRATION OF ZEBULARINE CAUSES A GENDER-SPECIFIC ABROGATION OF INTESTINAL TUMORS WHILE CAUSING A TISSUE-SPECIFIC DNA DEMETHYLATION. IMPORTANTLY, PROLONGED TREATMENT OF MICE WITH EPIGENETIC DRUGS RESULTED IN ONLY MINOR DEVELOPMENTAL AND HISTOLOGIC CHANGES. 2008 12 1820 39 EFFECTS OF CHRONIC RESTRAINT STRESS ON THE GLOBAL DNA METHYLATION PROFILE OF RAT LUNG CELLS: MODULATION BY PHYSICAL EXERCISE. THE POTENTIAL OF BEHAVIORAL STRESS TO AFFECT EPIGENETIC MECHANISMS OF NON-ENCEPHALIC TISSUES IS STILL UNDERESTIMATED. IN THE PRESENT STUDY WE EVALUATED THE EFFECTS OF CHRONIC BEHAVIORAL STRESS ON THE DNA METHYLATION PROFILE OF RAT LUNG CELLS. FURTHERMORE, WE EVALUATED THE POTENTIAL OF PHYSICAL EXERCISE TO MODULATE THE CHANGES EVOKED BY BEHAVIORAL STRESS IN LUNG CELLS. MALE WISTAR RATS WERE DIVIDED INTO FOUR EXPERIMENTAL GROUPS: (1) ANIMALS SUBMITTED TO CHRONIC RESTRAINT STRESS (CRS) (ST GROUP) DURING THE PERIOD OF THE 67TH-80TH POSTNATAL DAY (PND); (2) ANIMALS SUBMITTED TO PHYSICAL EXERCISE (EX GROUP) DURING THE 53RD-79TH PND; (3) ANIMALS SUBMITTED TO SWIMMING DURING THE 53RD-79TH PND AND TO CRS DURING THE 67TH-80TH PND (EX-ST GROUP); AND (4) ANIMALS NOT SUBMITTED TO STRESS OR SWIMMING PROTOCOLS (CTL). GLOBAL DNA METHYLATION WAS QUANTIFIED USING AN ELISA-BASED APPROACH AND GENE EXPRESSION WAS EVALUATED BY REAL TIME PCR. A DECREASED GLOBAL DNA METHYLATION PROFILE WAS OBSERVED IN THE ST GROUP, HOWEVER PHYSICAL EXERCISE DEMONSTRATED PROTECTION OF LUNG CELLS FROM THIS STRESS-RELATED HYPOMETHYLATION. INCREASED EXPRESSION OF THE DNMT1 GENE WAS EVIDENCED IN THE ST GROUP, WHEREAS PHYSICAL EXERCISE WAS SHOWN TO PROTECT LUNG CELLS FROM THIS STRESS-RELATED EFFECT IN THE EX-ST GROUP. COMPARATIVE ANALYSIS OF THE ST AND EX GROUPS REVEALED OPPOSITE EFFECTS ON THE EXPRESSION OF DNMT3A AND DNMT3B; HOWEVER, A STRESS-RELATED INCREASE IN EXPRESSION OF DNMT3A AND DNMT3B WAS NOT SEEN IN THE EX-ST GROUP. OUR DATA SHOWED THAT BEHAVIORAL STRESS INDUCED SIGNIFICANT CHANGES IN THE DNA METHYLATION PROFILE OF RAT LUNG CELLS AND THAT THIS COULD BE MODULATED BY PHYSICAL EXERCISE. 2017 13 904 49 CHRONIC EXPOSURE TO CADMIUM INDUCES DIFFERENTIAL METHYLATION IN MICE SPERMATOZOA. CADMIUM EXPOSURE IS UBIQUITOUS AND HAS BEEN LINKED TO DISEASES INCLUDING CANCERS AND REPRODUCTIVE DEFECTS. SINCE CADMIUM IS NONMUTAGENIC, IT IS THOUGHT TO EXERT ITS GENE DYSREGULATORY EFFECTS THROUGH EPIGENETIC REPROGRAMMING. SEVERAL STUDIES HAVE IMPLICATED GERMLINE EXPOSURE TO CADMIUM IN DEVELOPMENTAL REPROGRAMMING. HOWEVER, MOST OF THESE STUDIES HAVE FOCUSED ON MATERNAL EXPOSURE, WHILE THE IMPACT ON SPERM FERTILITY AND DISEASE SUSCEPTIBILITY HAS RECEIVED LESS ATTENTION. IN THIS STUDY, WE USED REDUCED REPRESENTATION BISULFITE SEQUENCING TO COMPREHENSIVELY INVESTIGATE THE IMPACT OF CHRONIC CADMIUM EXPOSURE ON MOUSE SPERMATOZOA DNA METHYLATION. ADULT MALE C57BL/J6 MICE WERE PROVIDED WATER WITH OR WITHOUT CADMIUM CHLORIDE FOR 9 WEEKS. SPERM, TESTES, LIVER, AND KIDNEY TISSUES WERE COLLECTED AT THE END OF THE TREATMENT PERIOD. CADMIUM EXPOSURE WAS CONFIRMED THROUGH GENE EXPRESSION ANALYSIS OF METALLOTHIONEIN-1 AND 2, 2 WELL-KNOWN CADMIUM-INDUCED GENES. ANALYSIS OF SPERM DNA METHYLATION CHANGES REVEALED 1788 DIFFERENTIALLY METHYLATED SITES PRESENT AT REGULATORY REGIONS IN SPERM OF MICE EXPOSED TO CADMIUM COMPARED WITH VEHICLE (CONTROL) MICE. FURTHERMORE, MOST OF THESE DIFFERENTIAL METHYLATION CHANGES POSITIVELY CORRELATED WITH CHANGES IN GENE EXPRESSION AT BOTH THE TRANSCRIPTION INITIATION STAGE AS WELL AS THE SPLICING LEVELS. INTERESTINGLY, THE GENES TARGETED BY CADMIUM EXPOSURE ARE INVOLVED IN SEVERAL CRITICAL DEVELOPMENTAL PROCESSES. OUR RESULTS PRESENT A COMPREHENSIVE ANALYSIS OF THE SPERM METHYLOME IN RESPONSE TO CHRONIC CADMIUM EXPOSURE. THESE DATA, THEREFORE, HIGHLIGHT A FOUNDATIONAL FRAMEWORK TO STUDY GENE EXPRESSION PATTERNS THAT MAY AFFECT FERTILITY IN THE EXPOSED INDIVIDUAL AS WELL AS THEIR OFFSPRING, THROUGH PATERNAL INHERITANCE. 2021 14 6794 35 [EFFECT OF BENZO(A)PYRENE ON THE EXPRESSION OF AHR-REGULATED MICRORNA IN FEMALE AND MALE RAT LUNGS]. SMOKING IS THE MAIN RISK FACTOR FOR LUNG CANCER, MAINLY DUE TO PRESENCE OF NITROSAMINES AND POLYCYCLIC AROMATIC HYDROCARBONS, INCLUDING BENZO[A]PYRENE (BP) IN TOBACCO SMOKE COMPOSITION. THE GENOTOXIC EFFECT OF BP IS BASED ON THE HIGH DNA-BINDING ABILITY OF ITS METABOLITES, WHILE THE EPIGENETIC EFFECTS ARE MEDIATED BY A CHANGE IN THE EXPRESSION OF CANCER RELATED GENES OR REGULATORY RNAS. IT HAS BEEN SHOWN THAT WOMEN HAVE A HIGHER RISK TO DEVELOP LUNG CANCER UPON SMOKING RATHER THAN MEN. WE HYPOTHESIZED THAT CROSSTALK BETWEEN SIGNALING PATHWAYS ACTIVATED BY BP AND ESTROGENS COULD UNDERLIE THE SEX-DEPENDENT DIFFERENCES IN MIRNAS EXPRESSION. TO TEST THIS HYPOTHESIS, MALE AND FEMALE RATS WERE SUBJECTED TO SHORT-TERM OR LONG-TERM BP EXPOSURE. USING IN SILICO ANALYSIS, MIRNAS CONTAINING THE ER- AND AHR-BINDING SITES IN THE PROMOTERS OF THE GENES (OR HOST GENES) WERE SELECTED. DURING CHRONIC EXPOSURE OF BP THE EXPRESSION OF MIR-22-3P, -29A-3P, -126A-3P, -193B-5P IN THE LUNGS OF MALE RATS WERE SIGNIFICANTLY INCREASED, WHILE THE LEVEL OF MIRNA-483-3P WERE DECREASED. EXPRESSION OF MIRNA-483-3P WAS UP-REGULATED DURING CHRONIC BP EXPOSURE IN THE LUNGS OF FEMALE RATS AND THE LEVELS OF OTHER STUDIED MIRNAS WERE UNCHANGED. IN TURN, CHANGES IN THE EXPRESSION OF MIRNAS WERE FOLLOWED BY CHANGES IN THE EXPRESSION OF THEIR TARGET GENES, INCLUDING PTEN, EMP2, IGF1, ITGA6, SLC34A2, AND THE OBSERVED CHANGES IN FEMALE AND MALE RAT LUNGS WERE VARIED. THUS, OUR RESULTS SUGGEST THAT SEX-DEPENDENT EPIGENETIC EFFECTS OF BP MAY BE BASED ON DIFFERENT EXPRESSION OF AHR- AND ER- REGULATED MIRNAS. 2020 15 1503 36 DNA METHYLATION AND GENE EXPRESSION DIFFERENCES IN CHILDREN CONCEIVED IN VITRO OR IN VIVO. EPIDEMIOLOGICAL DATA INDICATE THAT CHILDREN CONCEIVED IN VITRO HAVE A GREATER RELATIVE RISK OF LOW BIRTH-WEIGHT, MAJOR AND MINOR BIRTH DEFECTS, AND RARE DISORDERS INVOLVING IMPRINTED GENES, SUGGESTING THAT EPIGENETIC CHANGES MAY BE ASSOCIATED WITH ASSISTED REPRODUCTION. WE EXAMINED DNA METHYLATION AT MORE THAN 700 GENES (1536 CPG SITES) IN PLACENTA AND CORD BLOOD AND MEASURED GENE EXPRESSION LEVELS OF A SUBSET OF GENES THAT DIFFERED IN METHYLATION LEVELS BETWEEN CHILDREN CONCEIVED IN VITRO VERSUS IN VIVO. OUR RESULTS SUGGEST THAT IN VITRO CONCEPTION IS ASSOCIATED WITH LOWER MEAN METHYLATION AT CPG SITES IN PLACENTA AND HIGHER MEAN METHYLATION AT CPG SITES IN CORD BLOOD. WE ALSO FIND THAT IN VITRO CONCEPTION-ASSOCIATED DNA METHYLATION DIFFERENCES ARE ASSOCIATED WITH GENE EXPRESSION DIFFERENCES AT BOTH IMPRINTED AND NON-IMPRINTED GENES. THE RANGE OF INTER-INDIVIDUAL VARIATION IN GENE EXPRESSION OF THE IN VITRO AND IN VIVO GROUPS OVERLAPS SUBSTANTIALLY BUT SOME INDIVIDUALS FROM THE IN VITRO GROUP DIFFER FROM THE IN VIVO GROUP MEAN BY MORE THAN TWO STANDARD DEVIATIONS. SEVERAL OF THE GENES WHOSE EXPRESSION DIFFERS BETWEEN THE TWO GROUPS HAVE BEEN IMPLICATED IN CHRONIC METABOLIC DISORDERS, SUCH AS OBESITY AND TYPE II DIABETES. THESE FINDINGS SUGGEST THAT THERE MAY BE EPIGENETIC DIFFERENCES IN THE GAMETES OR EARLY EMBRYOS DERIVED FROM COUPLES UNDERGOING TREATMENT FOR INFERTILITY. ALTERNATIVELY, ASSISTED REPRODUCTION TECHNOLOGY MAY HAVE AN EFFECT ON GLOBAL PATTERNS OF DNA METHYLATION AND GENE EXPRESSION. IN EITHER CASE, THESE DIFFERENCES OR CHANGES MAY AFFECT LONG-TERM PATTERNS OF GENE EXPRESSION. 2009 16 3148 45 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 17 1117 40 COMPARATIVE AND EXPERIMENTAL STUDIES ON THE GENES ALTERED BY CHRONIC HYPOXIA IN HUMAN BRAIN MICROENDOTHELIAL CELLS. BACKGROUND : HYPOXIA INDUCIBLE FACTOR 1 ALPHA (HIF1A) IS A MASTER REGULATOR OF ACUTE HYPOXIA; HOWEVER, WITH CHRONIC HYPOXIA, HIF1A LEVELS RETURN TO THE NORMOXIC LEVELS. IMPORTANTLY, THE GENES THAT ARE INVOLVED IN THE CELL SURVIVAL AND VIABILITY UNDER CHRONIC HYPOXIA ARE NOT KNOWN. THEREFORE, WE TESTED THE HYPOTHESIS THAT CHRONIC HYPOXIA LEADS TO THE UPREGULATION OF A CORE GROUP OF GENES WITH ASSOCIATED CHANGES IN THE PROMOTER DNA METHYLATION THAT MEDIATES THE CELL SURVIVAL UNDER HYPOXIA. RESULTS : WE EXAMINED THE EFFECT OF CHRONIC HYPOXIA (3 DAYS; 0.5% OXYGEN) ON HUMAN BRAIN MICRO ENDOTHELIAL CELLS (HBMEC) VIABILITY AND APOPTOSIS. HYPOXIA CAUSED A SIGNIFICANT REDUCTION IN CELL VIABILITY AND AN INCREASE IN APOPTOSIS. NEXT, WE EXAMINED CHRONIC HYPOXIA ASSOCIATED CHANGES IN TRANSCRIPTOME AND GENOME-WIDE PROMOTER METHYLATION. THE DATA OBTAINED WAS COMPARED WITH 16 OTHER MICROARRAY STUDIES ON CHRONIC HYPOXIA. NINE GENES WERE ALTERED IN RESPONSE TO CHRONIC HYPOXIA IN ALL 17 STUDIES. INTERESTINGLY, HIF1A WAS NOT ALTERED WITH CHRONIC HYPOXIA IN ANY OF THE STUDIES. FURTHERMORE, WE COMPARED OUR DATA TO THREE OTHER STUDIES THAT IDENTIFIED HIF-RESPONSIVE GENES BY VARIOUS APPROACHES. ONLY TWO GENES WERE FOUND TO BE HIF DEPENDENT. WE SILENCED EACH OF THESE 9 GENES USING CRISPR/CAS9 SYSTEM. DOWNREGULATION OF EGLN3 SIGNIFICANTLY INCREASED THE CELL DEATH UNDER CHRONIC HYPOXIA, WHEREAS DOWNREGULATION OF ERO1L, ENO2, ADRENOMEDULLIN, AND SPAG4 REDUCED THE CELL DEATH UNDER HYPOXIA. CONCLUSIONS : WE PROVIDE A CORE GROUP OF GENES THAT REGULATES CELLULAR ACCLIMATIZATION UNDER CHRONIC HYPOXIC STRESS, AND MOST OF THEM ARE HIF INDEPENDENT. 2017 18 531 39 ASTROCYTE REACTIVITY FOLLOWING BLAST EXPOSURE INVOLVES ABERRANT HISTONE ACETYLATION. BLAST INDUCED NEUROTRAUMA (BINT) IS A PREVALENT INJURY WITHIN MILITARY AND CIVILIAN POPULATIONS. THE INJURY IS CHARACTERIZED BY PERSISTENT INFLAMMATION AT THE CELLULAR LEVEL WHICH MANIFESTS AS A MULTITUDE OF COGNITIVE AND FUNCTIONAL IMPAIRMENTS. EPIGENETIC REGULATION OF TRANSCRIPTION OFFERS AN IMPORTANT CONTROL MECHANISM FOR GENE EXPRESSION AND CELLULAR FUNCTION WHICH MAY UNDERLIE CHRONIC INFLAMMATION AND RESULT IN NEURODEGENERATION. WE HYPOTHESIZE THAT ALTERED HISTONE ACETYLATION PATTERNS MAY BE INVOLVED IN BLAST INDUCED INFLAMMATION AND THE CHRONIC ACTIVATION OF GLIAL CELLS. THIS STUDY AIMED TO ELUCIDATE CHANGES TO HISTONE ACETYLATION OCCURRING FOLLOWING INJURY AND THE ROLES THESE CHANGES MAY HAVE WITHIN THE PATHOLOGY. SPRAGUE DAWLEY RATS WERE SUBJECTED TO EITHER A 10 OR 17 PSI BLAST OVERPRESSURE WITHIN AN ADVANCED BLAST SIMULATOR (ABS). SHAM ANIMALS UNDERWENT THE SAME PROCEDURES WITHOUT BLAST EXPOSURE. MEMORY IMPAIRMENTS WERE MEASURED USING THE NOVEL OBJECT RECOGNITION (NOR) TEST AT 2 AND 7 DAYS POST-INJURY. TISSUES WERE COLLECTED AT 7 DAYS FOR WESTERN BLOT AND IMMUNOHISTOCHEMISTRY (IHC) ANALYSIS. SHAM ANIMALS SHOWED INTACT MEMORY AT EACH TIME POINT. THE NOVEL OBJECT DISCRIMINATION DECREASED SIGNIFICANTLY BETWEEN TWO AND 7 DAYS FOR EACH INJURY GROUP (P < 0.05). THIS IS INDICATIVE OF THE ONSET OF MEMORY IMPAIRMENT. WESTERN BLOT ANALYSIS SHOWED GLIAL FIBRILLARY ACIDIC PROTEIN (GFAP), A KNOWN MARKER OF ACTIVATED ASTROCYTES, WAS ELEVATED IN THE PREFRONTAL CORTEX (PFC) FOLLOWING BLAST EXPOSURE FOR BOTH INJURY GROUPS. ANALYSIS OF HISTONE PROTEIN EXTRACT SHOWED NO CHANGES IN THE LEVEL OF ANY TOTAL HISTONE PROTEINS WITHIN THE PFC. HOWEVER, ACETYLATION LEVELS OF HISTONE H2B, H3, AND H4 WERE DECREASED IN BOTH GROUPS (P < 0.05). CO-LOCALIZATION IMMUNOFLUORESCENCE WAS USED TO FURTHER INVESTIGATE ANY POTENTIAL CORRELATION BETWEEN DECREASED HISTONE ACETYLATION AND ASTROCYTE ACTIVATION. THESE EXPERIMENTS SHOWED A SIMILAR DECREASE IN H3 ACETYLATION IN ASTROCYTES EXPOSED TO A 17 PSI BLAST BUT NOT A 10 PSI BLAST. FURTHER INVESTIGATION OF GENE EXPRESSION BY POLYMERASE CHAIN REACTION (PCR) ARRAY, SHOWED DYSREGULATION OF SEVERAL CYTOKINE AND CYTOKINE RECEPTORS THAT ARE INVOLVED IN NEUROINFLAMMATORY PROCESSES. WE HAVE SHOWN ABERRANT HISTONE ACETYLATION PATTERNS INVOLVED IN BLAST INDUCED ASTROGLIOSIS AND COGNITIVE IMPAIRMENTS. FURTHER UNDERSTANDING OF THEIR ROLE IN THE INJURY PROGRESSION MAY LEAD TO NOVEL THERAPEUTIC TARGETS. 2016 19 344 39 ALTERED BDNF METHYLATION IN PATIENTS WITH CHRONIC MUSCULOSKELETAL PAIN AND HIGH BIOPSYCHOSOCIAL COMPLEXITY. PURPOSE: THE INTERMED INSTRUMENT, WHICH WAS DEVELOPED TO MEASURE PATIENT'S BIOPSYCHOSOCIAL (BPS) COMPLEXITY, REPRESENTS A POWERFUL DIAGNOSTIC AND THERAPEUTIC TOOL. EPIGENETIC CHANGES ARE THE INTERFACE BETWEEN SIGNALS FROM THE ENVIRONMENT AND GENETIC MODIFICATIONS, AFFECTING GENE EXPRESSION, IN PARTICULAR, BY DNA METHYLATION OF CPG DINUCLEOTIDES IN PROMOTOR REGIONS OF THE CORRESPONDING GENES. THE BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) GENE PLAYS A CRUCIAL ROLE IN THE CENTRAL SENSITIZATION (CS) OF PAIN. IN THIS STUDY, WE HYPOTHESIZED THAT CHRONIC PAIN MODIFIES THE METHYLATION LEVELS OF THE BDNF GENE IN A MANNER THAT IS INTERCONNECTED WITH THE BPS STATUS. PATIENTS AND METHODS: FIFTY-EIGHT CHRONIC MUSCULOSKELETAL PAIN PATIENTS (CMSP) WERE ENROLLED IN THE STUDY. DNA WAS EXTRACTED FROM BLOOD SAMPLES, THE METHYLATION LEVELS OF 13 CPG SITES IN THE BDNF PROMOTER WERE MEASURED BY PYROSEQUENCING, AND ASSOCIATION STUDIES WITH VARIOUS PATIENT PARAMETERS AND THE INTERMED SCORES WERE PERFORMED. RESULTS: INTERESTINGLY, A NEGATIVE CORRELATION (-0.40) WAS FOUND BETWEEN THE TOTAL INTERMED SCORES AND THE AVERAGE CPG METHYLATION VALUES OF THE BDNF GENE, BUT NO CORRELATION WAS OBSERVED WITH THE SEVERITY OF PAIN, DEGREE OF ANXIETY, DEPRESSION, OR KINESIOPHOBIA AND CATASTROPHISM. MOREOVER, THE ASSOCIATION WAS INDEPENDENT OF AGE, SEX AND LEVEL OF COMORBIDITIES. CONCLUSION: THIS RESULT SHOWS THAT CMSP, IN ASSOCIATION WITH ITS BIOPSYCHOSOCIAL CONTEXT, EPIGENETICALLY DECREASES THE DEGREE OF METHYLATION OF THE BDNF PROMOTER AND SHOULD THEREFORE INCREASE THE LEVEL OF BDNF TRANSCRIPTION. IT ALSO SUGGESTS A ROLE OF THE INTERMED TOOL TO DETECT A RELATIONSHIP BETWEEN THE BPS COMPLEXITY AND THE EPIGENETIC CONTROL OF A TARGET GENE. THE POSSIBLE UPREGULATION OF BDNF EXPRESSION MIGHT BE, AT LEAST IN PART, THE SIGNAL FOR CHRONIC PAIN-INDUCED CENTRAL SENSITIZATION (CS). THIS COULD PARTLY EXPLAIN WHY PATIENTS WITH A HIGHER LEVEL OF COMPLEXITY FEEL MORE PAIN THAN THOSE WITH LOWER COMPLEXITY. 2020 20 1655 22 DOSE-DEPENDENCE, SEX- AND TISSUE-SPECIFICITY, AND PERSISTENCE OF RADIATION-INDUCED GENOMIC DNA METHYLATION CHANGES. RADIATION IS A WELL-KNOWN GENOTOXIC AGENT AND HUMAN CARCINOGEN THAT GIVES RISE TO A VARIETY OF LONG-TERM EFFECTS. ITS DETRIMENTAL INFLUENCE ON CELLULAR FUNCTION IS ACTIVELY STUDIED NOWADAYS. ONE OF THE MOST ANALYZED, YET LEAST UNDERSTOOD LONG-TERM EFFECTS OF IONIZING RADIATION IS TRANSGENERATIONAL GENOMIC INSTABILITY. THE INHERITANCE OF GENOMIC INSTABILITY SUGGESTS THE POSSIBLE INVOLVEMENT OF EPIGENETIC MECHANISMS, SUCH AS CHANGES OF THE METHYLATION OF CYTOSINE RESIDUES LOCATED WITHIN CPG DINUCLEOTIDES. IN THE CURRENT STUDY WE EVALUATED THE DOSE-DEPENDENCE OF THE RADIATION-INDUCED GLOBAL GENOME DNA METHYLATION CHANGES. WE ALSO ANALYZED THE EFFECTS OF ACUTE AND CHRONIC HIGH DOSE (5GY) EXPOSURE ON DNA METHYLATION IN LIVER, SPLEEN, AND LUNG TISSUES OF MALE AND FEMALE MICE AND EVALUATED THE POSSIBLE PERSISTENCE OF THE RADIATION-INDUCED DNA METHYLATION CHANGES. HERE WE REPORT THAT RADIATION-INDUCED DNA METHYLATION CHANGES WERE SEX- AND TISSUE-SPECIFIC, DOSE-DEPENDENT, AND PERSISTENT. IN PARALLEL WE HAVE STUDIED THE LEVELS OF DNA DAMAGE IN THE EXPOSED TISSUES. BASED ON THE CORRELATION BETWEEN THE LEVELS OF DNA METHYLATION AND DNA DAMAGE WE PROPOSE THAT RADIATION-INDUCED GLOBAL GENOME DNA HYPOMETHYLATION IS DNA REPAIR-RELATED. 2004