1 1182 200 CONVERGING AND DIFFERENTIAL BRAIN PHOSPHOLIPID DYSREGULATION IN THE PATHOGENESIS OF REPETITIVE MILD TRAUMATIC BRAIN INJURY AND ALZHEIMER'S DISEASE. REPETITIVE MILD TRAUMATIC BRAIN INJURY (RMTBI) IS A MAJOR EPIGENETIC RISK FACTOR FOR ALZHEIMER'S DISEASE (AD). THE PRECISE NATURE OF HOW RMTBI LEADS TO OR PRECIPITATES AD PATHOLOGY IS CURRENTLY UNKNOWN. NUMEROUS NEUROLOGICAL CONDITIONS HAVE SHOWN AN IMPORTANT ROLE FOR DYSFUNCTIONAL PHOSPHOLIPID METABOLISM AS A DRIVING FACTOR FOR THE PATHOGENESIS OF NEURODEGENERATIVE DISEASES. HOWEVER, THE PRECISE ROLE IN RMTBI AND AD REMAINS ELUSIVE. WE HYPOTHESIZED THAT A DETAILED PHOSPHOLIPID CHARACTERIZATION WOULD REVEAL PROFILES OF RESPONSE TO INJURY IN TBI THAT OVERLAP WITH AGE-DEPENDENT CHANGES IN AD AND THUS PROVIDE INSIGHTS INTO THE TBI-AD RELATIONSHIP. WE EMPLOYED A LIPIDOMIC APPROACH EXAMINING BRAIN PHOSPHOLIPID PROFILES FROM MOUSE MODELS OF RMTBI AND AD. CORTEX AND HIPPOCAMPAL TISSUE WERE COLLECTED AT 24 H, 3, 6, 9, AND 12 MONTHS POST-RMTBI, AND AT AGES REPRESENTING 'PRE', 'PERI' AND 'POST' ONSET OF AMYLOID PATHOLOGY (I.E., 3, 9, 15 MONTHS-OLD). TOTAL LEVELS OF PHOSPHATIDYLCHOLINE (PC), PHOSPHATIDYLETHANOLAMINE (PE), LYSOPE, AND PHOSPHATIDYLINOSITOL (PI), INCLUDING THEIR MONOUNSATURATED, POLYUNSATURATED AND SATURATED FATTY ACID (FA) CONTAINING SPECIES WERE SIGNIFICANTLY INCREASED AT ACUTE AND/OR CHRONIC TIME POINTS POST-INJURY IN BOTH BRAIN REGIONS. HOWEVER, LEVELS OF MOST PHOSPHOLIPID SPECIES IN PS1/APP MICE WERE NOMINAL IN THE HIPPOCAMPUS, WHILE IN THE CORTEX, LEVELS WERE SIGNIFICANTLY DECREASED AT AGES POST-ONSET OF AMYLOID PATHOLOGY. SPHINGOMYELIN AND LYSOPC LEVELS SHOWED COINCIDENTAL TRENDS IN OUR RMTBI AND AD MODELS WITHIN THE HIPPOCAMPUS, AN INCREASE AT ACUTE AND/OR CHRONIC TIME POINTS EXAMINED. THE RATIO OF ARACHIDONIC ACID (OMEGA-6 FA) TO DOCOSAHEXAENOIC ACID (OMEGA-3 FA)-CONTAINING PE SPECIES WAS INCREASED AT EARLY TIME POINTS IN THE HIPPOCAMPUS OF INJURED VERSUS SHAM MICE, AND IN PS1/APP MICE THERE WAS A COINCIDENTAL INCREASE COMPARED TO WILD TYPE LITTERMATES AT ALL TIME POINTS. THIS STUDY DEMONSTRATES SOME OVERLAPPING AND DIVERSE PHOSPHOLIPID PROFILES IN RMTBI AND AD MODELS. FUTURE STUDIES ARE REQUIRED TO CORROBORATE OUR FINDINGS IN HUMAN POST-MORTEM TISSUE. INVESTIGATION OF SECONDARY MECHANISMS TRIGGERED BY ABERRANT DOWNSTREAM ALTERATIONS IN BIOACTIVE METABOLITES OF THESE PHOSPHOLIPIDS, AND THEIR MODULATION AT THE APPROPRIATE TIME-WINDOWS OF OPPORTUNITY COULD HELP FACILITATE DEVELOPMENT OF NOVEL THERAPEUTIC STRATEGIES TO AMELIORATE THE NEURODEGENERATIVE CONSEQUENCES OF RMTBI OR THE POTENTIAL TRIGGERING OF AD PATHOGENESIS BY RMTBI. 2019 2 5464 35 RESILIENCE IN LONG-TERM VIRAL INFECTION: GENETIC DETERMINANTS AND INTERACTIONS. VIRUS-INDUCED NEUROLOGICAL SEQUELAE RESULTING FROM INFECTION BY THEILER'S MURINE ENCEPHALOMYELITIS VIRUS (TMEV) ARE USED FOR STUDYING HUMAN CONDITIONS RANGING FROM EPILEPTIC SEIZURES TO DEMYELINATING DISEASE. MOUSE STRAINS ARE TYPICALLY CONSIDERED SUSCEPTIBLE OR RESISTANT TO TMEV INFECTION BASED ON VIRAL PERSISTENCE AND EXTREME PHENOTYPES, SUCH AS DEMYELINATION. WE HAVE IDENTIFIED A BROADER SPECTRUM OF PHENOTYPIC OUTCOMES BY INFECTING STRAINS OF THE GENETICALLY DIVERSE COLLABORATIVE CROSS (CC) MOUSE RESOURCE. WE EVALUATED THE CHRONIC-INFECTION GENE EXPRESSION PROFILES OF HIPPOCAMPI AND THORACIC SPINAL CORDS FOR 19 CC STRAINS IN RELATION TO PHENOTYPIC SEVERITY AND TMEV PERSISTENCE. STRAINS WERE CLUSTERED BASED ON SIMILAR PHENOTYPIC PROFILES AND TMEV LEVELS AT 90 DAYS POST-INFECTION, AND WE CATEGORIZED DISTINCT TMEV RESPONSE PROFILES. THE THREE MOST COMMON PROFILES INCLUDED "RESISTANT" AND "SUSCEPTIBLE," AS BEFORE, AS WELL AS A "RESILIENT" TMEV RESPONSE GROUP WHICH EXPERIENCED BOTH TMEV PERSISTENCE AND MILD NEUROLOGICAL PHENOTYPES EVEN AT 90 DAYS POST-INFECTION. EACH PROFILE HAD A DISTINCT GENE EXPRESSION SIGNATURE, ALLOWING THE IDENTIFICATION OF PATHWAYS AND NETWORKS SPECIFIC TO EACH TMEV RESPONSE GROUP. CC FOUNDER HAPLOTYPES FOR GENES INVOLVED IN THESE PATHWAYS/NETWORKS REVEALED CANDIDATE RESPONSE-SPECIFIC ALLELES. THESE ALLELES DEMONSTRATED PLEIOTROPY AND EPIGENETIC (MIRNA) REGULATION IN LONG-TERM TMEV INFECTION, WITH PARTICULAR RELEVANCE FOR RESILIENT MOUSE STRAINS. 2021 3 2246 33 EPIGENETIC MODULATION OF INFLAMMATION AND SYNAPTIC PLASTICITY PROMOTES RESILIENCE AGAINST STRESS IN MICE. MAJOR DEPRESSIVE DISORDER IS ASSOCIATED WITH ABNORMALITIES IN THE BRAIN AND THE IMMUNE SYSTEM. CHRONIC STRESS IN ANIMALS SHOWED THAT EPIGENETIC AND INFLAMMATORY MECHANISMS PLAY IMPORTANT ROLES IN MEDIATING RESILIENCE AND SUSCEPTIBILITY TO DEPRESSION. HERE, THROUGH A HIGH-THROUGHPUT SCREENING, WE IDENTIFY TWO PHYTOCHEMICALS, DIHYDROCAFFEIC ACID (DHCA) AND MALVIDIN-3'-O-GLUCOSIDE (MAL-GLUC) THAT ARE EFFECTIVE IN PROMOTING RESILIENCE AGAINST STRESS BY MODULATING BRAIN SYNAPTIC PLASTICITY AND PERIPHERAL INFLAMMATION. DHCA/MAL-GLUC ALSO SIGNIFICANTLY REDUCES DEPRESSION-LIKE PHENOTYPES IN A MOUSE MODEL OF INCREASED SYSTEMIC INFLAMMATION INDUCED BY TRANSPLANTATION OF HEMATOPOIETIC PROGENITOR CELLS FROM STRESS-SUSCEPTIBLE MICE. DHCA REDUCES PRO-INFLAMMATORY INTERLEUKIN 6 (IL-6) GENERATIONS BY INHIBITING DNA METHYLATION AT THE CPG-RICH IL-6 SEQUENCES INTRONS 1 AND 3, WHILE MAL-GLUC MODULATES SYNAPTIC PLASTICITY BY INCREASING HISTONE ACETYLATION OF THE REGULATORY SEQUENCES OF THE RAC1 GENE. PERIPHERAL INFLAMMATION AND SYNAPTIC MALADAPTATION ARE IN LINE WITH NEWLY HYPOTHESIZED CLINICAL INTERVENTION TARGETS FOR DEPRESSION THAT ARE NOT ADDRESSED BY CURRENTLY AVAILABLE ANTIDEPRESSANTS. 2018 4 1584 30 DNA METHYLATION PROFILES OF SELECTED PRO-INFLAMMATORY CYTOKINES IN ALZHEIMER DISEASE. BY MEANS OF FUNCTIONAL GENOMICS ANALYSIS, WE RECENTLY DESCRIBED THE MRNA EXPRESSION PROFILES OF VARIOUS GENES INVOLVED IN THE NEUROINFLAMMATORY RESPONSE IN THE BRAINS OF SUBJECTS WITH LATE-ONSET ALZHEIMER DISEASE (LOAD). SOME OF THESE GENES, NAMELY INTERLEUKIN (IL)-1BETA AND IL-6, SHOWED DISTINCT EXPRESSION PROFILES WITH PEAK EXPRESSION DURING THE FIRST STAGES OF THE DISEASE AND CONTROL-LIKE LEVELS AT LATER STAGES. IL-1BETA AND IL-6 GENES ARE MODULATED BY DNA METHYLATION IN DIFFERENT CHRONIC AND DEGENERATIVE DISEASES; IT IS ALSO WELL KNOWN THAT LOAD MAY HAVE AN EPIGENETIC BASIS. INDEED, WE AND OTHERS HAVE PREVIOUSLY REPORTED GENE-SPECIFIC DNA METHYLATION ALTERATIONS IN LOAD AND IN RELATED ANIMAL MODELS. BASED ON THESE DATA, WE STUDIED THE DNA METHYLATION PROFILES, AT SINGLE CYTOSINE RESOLUTION, OF IL-1BETA AND IL-6 5'-FLANKING REGION BY BISULPHITE MODIFICATION IN THE CORTEX OF HEALTHY CONTROLS AND LOAD PATIENTS AT 2 DIFFERENT DISEASE STAGES: BRAAK I-II/A AND BRAAK V-VI/C. OUR ANALYSIS PROVIDES EVIDENCE THAT NEUROINFLAMMATION IN LOAD IS ASSOCIATED WITH (AND POSSIBLY MEDIATED BY) EPIGENETIC MODIFICATIONS. 2017 5 1162 37 CONTRASTING EFFECTS OF ACUTE AND CHRONIC STRESS ON THE TRANSCRIPTOME, EPIGENOME, AND IMMUNE RESPONSE OF ATLANTIC SALMON. STRESS EXPERIENCED DURING EARLY LIFE MAY HAVE LASTING EFFECTS ON THE IMMUNE SYSTEM, WITH IMPACTS ON HEALTH AND DISEASE DEPENDENT ON THE NATURE AND DURATION OF THE STRESSOR. THE EPIGENOME IS ESPECIALLY SENSITIVE TO ENVIRONMENTAL STIMULI DURING EARLY LIFE AND REPRESENTS A POTENTIAL MECHANISM THROUGH WHICH STRESS MAY CAUSE LONG-LASTING HEALTH EFFECTS. HOWEVER, THE EXTENT TO WHICH THE EPIGENOME RESPONDS DIFFERENTLY TO CHRONIC VS ACUTE STRESSORS IS UNCLEAR, ESPECIALLY FOR NON-MAMMALIAN SPECIES. WE EXAMINED THE EFFECTS OF ACUTE STRESS (COLD-SHOCK DURING EMBRYOGENESIS) AND CHRONIC STRESS (ABSENCE OF TANK ENRICHMENT DURING LARVAL-STAGE) ON GLOBAL GENE EXPRESSION (USING RNA-SEQ) AND DNA METHYLATION (USING RRBS) IN THE GILLS OF ATLANTIC SALMON (SALMO SALAR) FOUR MONTHS AFTER HATCHING. CHRONIC STRESS INDUCED PRONOUNCED TRANSCRIPTIONAL DIFFERENCES, WHILE ACUTE STRESS CAUSED FEW LASTING TRANSCRIPTIONAL EFFECTS. HOWEVER, BOTH ACUTE AND CHRONIC STRESS CAUSED LASTING AND CONTRASTING CHANGES IN THE METHYLOME. CRUCIALLY, WE FOUND THAT ACUTE STRESS ENHANCED TRANSCRIPTIONAL IMMUNE RESPONSE TO A PATHOGENIC CHALLENGE (BACTERIAL LIPOPOLYSACCHARIDE, LPS), WHILE CHRONIC STRESS SUPPRESSED IT. WE IDENTIFIED STRESS-INDUCED CHANGES IN PROMOTER AND GENE-BODY METHYLATION THAT WERE ASSOCIATED WITH ALTERED EXPRESSION FOR A SMALL PROPORTION OF IMMUNE-RELATED GENES, AND EVIDENCE OF WIDER EPIGENETIC REGULATION WITHIN SIGNALLING PATHWAYS INVOLVED IN IMMUNE RESPONSE. OUR RESULTS SUGGEST THAT STRESS CAN AFFECT IMMUNO-COMPETENCE THROUGH EPIGENETIC MECHANISMS, AND HIGHLIGHT THE MARKEDLY DIFFERENT EFFECTS OF CHRONIC LARVAL AND ACUTE EMBRYONIC STRESS. THIS KNOWLEDGE COULD BE USED TO HARNESS THE STIMULATORY EFFECTS OF ACUTE STRESS ON IMMUNITY, PAVING THE WAY FOR IMPROVED STRESS AND DISEASE MANAGEMENT THROUGH EPIGENETIC CONDITIONING. 2018 6 2776 50 EXTRAUTERINE GROWTH RESTRICTION ON PULMONARY VASCULAR ENDOTHELIAL DYSFUNCTION IN ADULT MALE RATS: THE ROLE OF EPIGENETIC MECHANISMS. OBJECTIVE: EARLY POSTNATAL LIFE IS CONSIDERED AS A CRITICAL TIME WINDOW FOR THE DETERMINATION OF LONG-TERM METABOLIC STATES AND ORGAN FUNCTIONS. EXTRAUTERINE GROWTH RESTRICTION (EUGR) CAUSES THE DEVELOPMENT OF ADULT-ONSET CHRONIC DISEASES, INCLUDING PULMONARY HYPERTENSION. HOWEVER, THE EFFECTS OF NUTRITIONAL DISADVANTAGES DURING THE EARLY POSTNATAL PERIOD ON PULMONARY VASCULAR CONSEQUENCES IN LATER LIFE ARE NOT FULLY UNDERSTOOD. OUR STUDY WAS DESIGNED TO TEST WHETHER EPIGENETICS DYSREGULATION MEDIATES THE CELLULAR MEMORY OF THIS EARLY POSTNATAL EVENT. METHODS AND RESULTS: TO TEST THIS HYPOTHESIS, WE ISOLATED PULMONARY VASCULAR ENDOTHELIAL CELLS BY MAGNETIC-ACTIVATED CELL SORTING FROM EUGR AND CONTROL RATS. A POSTNATAL INSULT, NUTRITIONAL RESTRICTION-INDUCED EUGR CAUSED DEVELOPMENT OF AN INCREASED PULMONARY ARTERY PRESSURE AT 9 WEEKS OF AGE IN MALE SPRAGUE-DAWLEY RATS. METHYL-DNA IMMUNE PRECIPITATION CHIP, GENOME-SCALE MAPPING STUDIES TO SEARCH FOR DIFFERENTIALLY METHYLATED LOCI BETWEEN CONTROL AND EUGR RATS, REVEALED SIGNIFICANT DIFFERENCE IN CYTOSINE METHYLATION BETWEEN EUGR AND CONTROL RATS. EUGR CHANGES THE CYTOSINE METHYLATION AT APPROXIMATELY 500 LOCI IN MALE RATS AT 9 WEEKS OF AGE, PRECEDING THE DEVELOPMENT OF PULMONARY HYPERTENSION AND THESE REPRESENT THE CANDIDATE LOCI FOR MEDIATING THE PATHOGENESIS OF PULMONARY VASCULAR DISEASE THAT OCCURS LATER IN LIFE. GENE ONTOLOGY ANALYSIS ON DIFFERENTIALLY METHYLATED GENES SHOWED THAT HYPERMETHYLATED GENES IN EUGR ARE VASCULAR DEVELOPMENT-ASSOCIATED GENES AND HYPOMETHYLATED GENES IN EUGR ARE LATE-DIFFERENTIATION-ASSOCIATED AND SIGNAL TRANSDUCTION GENES. WE VALIDATED CANDIDATE DYSREGULATED LOCI WITH THE QUANTITATIVE ASSAYS OF CYTOSINE METHYLATION AND GENE EXPRESSIONS. CONCLUSION: THESE RESULTS DEMONSTRATE THAT EPIGENETICS DYSREGULATION IS A STRONG MECHANISM FOR PROPAGATING THE CELLULAR MEMORY OF EARLY POSTNATAL EVENTS, CAUSING CHANGES IN THE EXPRESSION OF GENES AND LONG-TERM SUSCEPTIBILITY TO PULMONARY HYPERTENSION, AND FURTHER PROVIDING A NEW INSIGHT INTO THE PREVENTION AND TREATMENT OF EUGR-RELATED PULMONARY HYPERTENSION. 2014 7 5468 34 RESISTANCE TRAINING AND REDOX HOMEOSTASIS: CORRELATION WITH AGE-ASSOCIATED GENOMIC CHANGES. REGULAR PHYSICAL ACTIVITY IS EFFECTIVE AS PREVENTION AND TREATMENT FOR DIFFERENT CHRONIC CONDITIONS RELATED TO THE AGEING PROCESSES. IN FACT, A SEDENTARY LIFESTYLE HAS BEEN LINKED TO A WORSENING OF CELLULAR AGEING BIOMARKERS SUCH AS TELOMERE LENGTH (TL) AND/OR SPECIFIC EPIGENETIC CHANGES (E.G. DNA METHYLATION), WITH INCREASE OF THE PROPENSITY TO AGING-RELATED DISEASES AND PREMATURE DEATH. EXTENDING OUR PREVIOUS FINDINGS, WE AIMED TO TEST THE HYPOTHESIS THAT 12 WEEKS OF LOW FREQUENCY, MODERATE INTENSITY, EXPLOSIVE-TYPE RESISTANCE TRAINING (EMRT) MAY ATTENUATE AGE-ASSOCIATED GENOMIC CHANGES. TO THIS AIM, TL, GLOBAL DNA METHYLATION, TRF2, KU80, SIRT1, SIRT2 AND GLOBAL PROTEIN ACETYLATION, AS WELL AS OTHER PROTEINS INVOLVED IN APOPTOTIC PATHWAY (BCL-2, BAX AND CASPASE-3), ANTIOXIDANT RESPONSE (TRXR1 AND MNSOD) AND OXIDATIVE DAMAGE (MYELOPEROXIDASE) WERE EVALUATED BEFORE AND AFTER EMRT IN WHOLE BLOOD OR PERIPHERAL MONONUCLEAR CELLS (PBMCS) OF ELDERLY SUBJECTS. OUR FINDINGS CONFIRM THE POTENTIAL OF EMRT TO INDUCE AN ADAPTIVE CHANGE IN THE ANTIOXIDANT PROTEIN SYSTEMS AT SYSTEMIC LEVEL AND SUGGEST A PUTATIVE ROLE OF RESISTANCE TRAINING IN THE REDUCTION OF GLOBAL DNA METHYLATION. MOREOVER, WE OBSERVED THAT EMRT COUNTERACTS THE TELOMERES' SHORTENING IN A MANNER THAT PROVED TO BE DIRECTLY CORRELATED WITH THE AMELIORATION OF REDOX HOMEOSTASIS AND EFFICACY OF TRAINING REGIME, EVALUATED AS IMPROVEMENT OF BOTH MUSCLE'S POWER/STRENGTH AND FUNCTIONAL PARAMETERS. 2016 8 5205 36 PRENATAL STRESS CHANGES THE GLYCOPROTEIN GPM6A GENE EXPRESSION AND INDUCES EPIGENETIC CHANGES IN RAT OFFSPRING BRAIN. PRENATAL STRESS (PS) EXERTS STRONG IMPACT ON FETAL BRAIN DEVELOPMENT AND ON ADULT OFFSPRING BRAIN FUNCTIONS. PREVIOUS WORK DEMONSTRATED THAT CHRONIC STRESS ALTERS THE MRNA EXPRESSION OF GPM6A, A NEURONAL GLYCOPROTEIN INVOLVED IN FILOPODIUM EXTENSION. IN THIS WORK, WE ANALYZED THE EFFECT OF PS ON GPM6A EXPRESSION AND THE EPIGENETIC MECHANISMS INVOLVED. PREGNANT WISTAR RATS RECEIVED RESTRAINT STRESS DURING THE LAST WEEK OF GESTATION. MALE OFFSPRING WERE SACRIFICED ON POSTNATAL DAYS 28 AND 60. HIPPOCAMPUS AND PREFRONTAL CORTEX SAMPLES WERE ANALYZED FOR GENE EXPRESSION (QPCR FOR MRNAS AND MICRORNAS), METHYLATION STATUS (BISULFITE CONVERSION) AND PROTEIN LEVELS. HIPPOCAMPAL NEURONS IN CULTURE WERE USED TO ANALYZE MICRORNA OVEREXPRESSION EFFECTS. PRENATAL STRESS INDUCED CHANGES IN GPM6A LEVELS IN BOTH TISSUES AND AT BOTH AGES ANALYZED, INDICATING A PERSISTENT EFFECT. TWO CPG ISLANDS IN THE GPM6A GENE WERE IDENTIFIED. VARIATIONS IN THE METHYLATION PATTERN AT THREE SPECIFIC CPGS WERE FOUND IN HIPPOCAMPUS, BUT NOT IN PFC SAMPLES FROM PS OFFSPRING. MICRORNAS PREDICTED TO TARGET GPM6A WERE IDENTIFIED IN SILICO. QPCR MEASUREMENTS SHOWED THAT PS MODIFIED THE EXPRESSION OF SEVERAL MICRORNAS IN BOTH TISSUES, BEING MICRORNA-133B THE MOST SIGNIFICANTLY ALTERED. FURTHER STUDIES OVEREXPRESSING THIS MICRORNA IN NEURONAL CULTURES SHOWED A REDUCTION IN GMP6A MRNA AND PROTEIN LEVEL. MOREOVER FILOPODIUM DENSITY WAS ALSO REDUCED, SUGGESTING THAT GPM6A FUNCTION WAS AFFECTED. GESTATIONAL STRESS AFFECTED GPM6A GENE EXPRESSION IN OFFSPRING LIKELY THROUGH CHANGES IN METHYLATION STATUS AND IN POSTTRANSCRIPTIONAL REGULATION BY MICRORNAS. THUS, OUR FINDINGS PROPOSE GPM6A AS A NOVEL TARGET FOR EPIGENETIC REGULATION DURING PRENATAL STRESS. 2014 9 20 41 5-HYDROXYMETHYLATION-ASSOCIATED EPIGENETIC MODIFIERS OF ALZHEIMER'S DISEASE MODULATE TAU-INDUCED NEUROTOXICITY. ALZHEIMER'S DISEASE (AD) IS A CHRONIC NEURODEGENERATIVE DISORDER CHARACTERIZED BY PROGRESSIVE DETERIORATION OF COGNITIVE FUNCTION. PATHOGENESIS OF AD IS INCOMPLETELY UNDERSTOOD; EVIDENCE SUGGESTS A ROLE FOR EPIGENETIC REGULATION, IN PARTICULAR THE CYTOSINE MODIFICATIONS 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE (5HMC). 5HMC IS ENRICHED IN THE NERVOUS SYSTEM AND DISPLAYS NEURODEVELOPMENT AND AGE-RELATED CHANGES. TO DETERMINE THE ROLE OF 5HMC IN AD, WE PERFORMED GENOME-WIDE ANALYSES OF 5HMC IN DNA FROM PREFRONTAL CORTEX OF POST-MORTEM AD PATIENTS, AND RNA-SEQ TO CORRELATE CHANGES IN 5HMC WITH TRANSCRIPTIONAL CHANGES. WE IDENTIFIED 325 GENES CONTAINING DIFFERENTIALLY HYDROXYMETHYLATED LOCI (DHMLS) IN BOTH DISCOVERY AND REPLICATION DATASETS. THESE ARE ENRICHED FOR PATHWAYS INVOLVED IN NEURON PROJECTION DEVELOPMENT AND NEUROGENESIS. OF THESE, 140 SHOWED CHANGES IN GENE EXPRESSION. PROTEINS ENCODED BY THESE GENES FORM DIRECT PROTEIN-PROTEIN INTERACTIONS WITH AD-ASSOCIATED GENES, EXPANDING THE NETWORK OF GENES IMPLICATED IN AD. WE IDENTIFIED AD-ASSOCIATED SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) LOCATED WITHIN OR NEAR DHMLS, SUGGESTING THESE SNPS MAY IDENTIFY REGIONS OF EPIGENETIC GENE REGULATION THAT PLAY A ROLE IN AD PATHOGENESIS. FINALLY, USING AN EXISTING AD FLY MODEL, WE SHOWED SOME OF THESE GENES MODULATE AD-ASSOCIATED TOXICITY. OUR DATA IMPLICATE NEURONAL PROJECTION DEVELOPMENT AND NEUROGENESIS PATHWAYS AS POTENTIAL TARGETS IN AD. BY INCORPORATING EPIGENOMIC AND TRANSCRIPTOMIC DATA WITH GENOME-WIDE ASSOCIATION STUDIES DATA, WITH VERIFICATION IN THE DROSOPHILA MODEL, WE CAN EXPAND THE KNOWN NETWORK OF GENES INVOLVED IN DISEASE PATHOGENESIS AND IDENTIFY EPIGENETIC MODIFIERS OF ALZHEIMER'S DISEASE. 2016 10 2886 33 GABA-AALPHA5 MIGHT BE INVOLVED IN LEARNING-MEMORY DYSFUNCTION IN THE OFFSPRINGS OF CHRONIC ETHANOL-TREATED RATS VIA GABA-AALPHA5 HISTONE H3K9 ACETYLATION. RECENTLY, NUMEROUS STUDIES HAVE BEEN FOCUSED ON THE RELATIONSHIP BETWEEN GABA-A RECEPTORS AND ALCOHOL-INDUCED SPATIAL LEARNING AND MEMORY DEFICITS. GABA-AALPHA5, A SUBUNIT OF GABA-A RECEPTORS, IS CONSIDERED TO PLAY AN IMPORTANT ROLE IN ALCOHOL-INDUCED COGNITIVE IMPAIRMENT, HOWEVER, THE MECHANISM REMAINS OBSCURE. IN THIS STUDY, WE FOUND THAT THE EXPRESSION OF GABA-AALPHA5 INCREASED IN RATS TREATED WITH CHRONIC ETHANOL VIA HISTONE H3K9 ACETYLATION. FURTHERMORE, THIS EPIGENETIC MODIFICATION COULD BE INHERITED BY THE NEXT GENERATIONS, WHICH EVENTUALLY EXHIBIT SIMILAR SPATIAL LEARNING AND MEMORY DEFICITS IN THE OFFSPRINGS. IN SUMMARY, OUR RESULTS SUGGESTED THAT GABA-AALPHA5 MIGHT BE INVOLVED IN CHRONIC ETHANOL TREATMENT-INDUCED LEARNING-MEMORY DYSFUNCTION AND FOR THE FIRST TIME PROVED THAT LEARNING-MEMORY DYSFUNCTION COULD BE INHERITED BY THE OFFSPRINGS VIA HISTONE H3K9 ACETYLATION. HOPEFULLY, IN THE NEAR FUTURE, GABA-AALPHA5 INHIBITORS WOULD BE AN EFFECTIVE WAY TO TREAT ALCOHOL-INDUCED COGNITION IMPAIRMENT. 2019 11 4736 47 NOVEL EPIGENETIC BIOMARKERS MEDIATING BISPHENOL A EXPOSURE AND METABOLIC PHENOTYPES IN FEMALE MICE. THERE IS COMPELLING EVIDENCE THAT EPIGENETIC MODIFICATIONS LINK DEVELOPMENTAL ENVIRONMENTAL INSULTS TO ADULT DISEASE SUSCEPTIBILITY. ANIMAL STUDIES HAVE ASSOCIATED PERINATAL BISPHENOL A (BPA) EXPOSURE TO ALTERED DNA METHYLATION, BUT THESE STUDIES ARE OFTEN LIMITED TO CANDIDATE GENE AND GLOBAL NON-LOCI-SPECIFIC APPROACHES. BY USING AN EPIGENOME-WIDE DISCOVERY PLATFORM, WE ELUCIDATED EPIGENETIC ALTERATIONS IN LIVER TISSUE FROM ADULT MICE OFFSPRING (10 MONTHS) FOLLOWING PERINATAL BPA EXPOSURE AT HUMAN PHYSIOLOGICALLY RELEVANT DOSES (50-NG, 50-MUG, AND 50-MG BPA/KG DIET). BIOLOGICAL PATHWAY ANALYSIS IDENTIFIED AN ENRICHMENT OF SIGNIFICANT DIFFERENTIALLY METHYLATED REGIONS IN METABOLIC PATHWAYS AMONG FEMALES. FURTHERMORE, THROUGH THE USE OF TOP ENRICHED BIOLOGICAL PATHWAYS, 4 CANDIDATE GENES WERE CHOSEN TO ASSESS DNA METHYLATION AS A MEDIATING FACTOR LINKING THE ASSOCIATION OF PERINATAL BPA EXPOSURE TO METABOLIC PHENOTYPES PREVIOUSLY OBSERVED IN FEMALE OFFSPRING. DNA METHYLATION STATUS AT JANUS KINASE-2 (JAK-2), RETINOID X RECEPTOR (RXR), REGULATORY FACTOR X-ASSOCIATED PROTEIN (RFXAP), AND TRANSMEMBRANE PROTEIN 238 (TMEM238) WAS USED WITHIN A MEDIATIONAL REGRESSION ANALYSIS. DNA METHYLATION IN ALL FOUR OF THE CANDIDATE GENES WAS IDENTIFIED AS A MEDIATOR IN THE MECHANISTIC PATHWAY OF DEVELOPMENTAL BPA EXPOSURE AND FEMALE-SPECIFIC ENERGY EXPENDITURE, BODY WEIGHT, AND BODY FAT PHENOTYPES. DATA GENERATED FROM THIS STUDY ARE CRUCIAL FOR DECIPHERING THE MECHANISTIC ROLE OF EPIGENETICS IN THE PATHOGENESIS OF CHRONIC DISEASE AND THE DEVELOPMENT OF EPIGENETIC-BASED PREVENTION AND THERAPEUTIC STRATEGIES FOR COMPLEX HUMAN DISEASE. 2017 12 889 35 CHRONIC DIETARY ADMINISTRATION OF VALPROIC ACID PROTECTS NEURONS OF THE RAT NUCLEUS BASALIS MAGNOCELLULARIS FROM IBOTENIC ACID NEUROTOXICITY. VALPROIC ACID (VPA) HAS BEEN USED FOR MANY YEARS AS A DRUG OF CHOICE FOR EPILEPSY AND MOOD DISORDERS. RECENTLY, EVIDENCE HAS BEEN PROPOSED FOR A WIDE SPECTRUM OF ACTIONS OF THIS DRUG, INCLUDING ANTITUMORAL AND NEUROPROTECTIVE PROPERTIES. VALPROIC ACID-MEDIATED NEUROPROTECTION IN VIVO HAS BEEN SO FAR DEMONSTRATED IN A LIMITED NUMBER OF EXPERIMENTAL MODELS. IN THIS STUDY, WE HAVE TESTED THE NEUROPROTECTIVE POTENTIAL OF CHRONIC (4 + 1 WEEKS) DIETARY ADMINISTRATION OF VPA ON DEGENERATION OF CHOLINERGIC AND GABAERGIC NEURONS OF THE RAT NUCLEUS BASALIS MAGNOCELLULARIS (NBM), INJECTED WITH THE EXCITOTOXIN, IBOTENIC ACID (IBO), AN ANIMAL MODELS THAT IS RELEVANT FOR ALZHEIMER'S DISEASE-LIKE NEURODEGENERATION. WE SHOW THAT VPA TREATMENT SIGNIFICANTLY PROTECTS BOTH CHOLINERGIC AND GABAERGIC NEURONS PRESENT IN THE INJECTED AREA FROM THE EXCITOTOXIC INSULT. A SIGNIFICANT LEVEL OF NEUROPROTECTION, IN PARTICULAR, IS EXERTED TOWARDS THE CHOLINERGIC NEURONS OF THE NBM PROJECTING TO THE CORTEX, AS DEMONSTRATED BY THE SUBSTANTIALLY HIGHER LEVELS OF CHOLINERGIC MARKERS MAINTAINED IN THE TARGET CORTICAL AREA OF VPA-TREATED RATS AFTER IBO INJECTION IN THE NBM. WE FURTHER SHOW THAT CHRONIC VPA ADMINISTRATION RESULTS IN INCREASED ACETYLATION OF HISTONE H3 IN BRAIN, CONSISTENT WITH THE HISTONE DEACETYLASE INHIBITORY ACTION OF VPA AND PUTATIVELY LINKED TO A NEUROPROTECTIVE ACTION OF THE DRUG MEDIATED AT THE EPIGENETIC LEVEL. 2009 13 491 31 ASSESSING THE IMPACT OF POLYETHYLENE NANO/MICROPLASTIC EXPOSURE ON HUMAN VAGINAL KERATINOCYTES. THE GLOBAL RISE OF SINGLE-USE THROW-AWAY PLASTIC PRODUCTS HAS ELICITED A MASSIVE INCREASE IN THE NANO/MICROPLASTICS (N/MPLS) EXPOSURE BURDEN IN HUMANS. RECENTLY, IT HAS BEEN DEMONSTRATED THAT DISPOSABLE PERIOD PRODUCTS MAY RELEASE N/MPLS WITH USAGE, WHICH REPRESENTS A POTENTIAL THREAT TO WOMEN'S HEALTH WHICH HAS NOT BEEN SCIENTIFICALLY ADDRESSED YET. BY USING POLYETHYL ENE (PE) PARTICLES (200 NM TO 9 MUM), WE SHOWED THAT ACUTE EXPOSURE TO A HIGH CONCENTRATION OF N/MPLS INDUCED CELL TOXICITY IN VAGINAL KERATINOCYTES AFTER EFFECTIVE CELLULAR UPTAKE, AS VIABILITY AND APOPTOSIS DATA SUGGEST, ALONG WITH TRANSMISSION ELECTRON MICROSCOPY (TEM) OBSERVATIONS. THE INTERNALISED N/MPLS ALTERED THE EXPRESSION OF JUNCTIONAL AND ADHERENCE PROTEINS AND THE ORGANISATION OF THE ACTIN CORTEX, INFLUENCING THE LEVEL OF GENES INVOLVED IN OXIDATIVE STRESS SIGNALLING PATHWAYS AND THAT OF MIRNAS RELATED TO EPITHELIAL BARRIER FUNCTION. WHEN THE EXPOSURE TO PE N/MPLS WAS DISCONTINUED OR BECAME CHRONIC, CELLS WERE ABLE TO RECOVER FROM THE NEGATIVE EFFECTS ON VIABILITY AND DIFFERENTIATION/PROLIFERATION GENE EXPRESSION IN A FEW DAYS. HOWEVER, IN ALL CASES, PE N/MPL EXPOSURE PROMPTED A SUSTAINED ALTERATION OF DNA METHYLTRANSFERASE AND DNA DEMETHYLASE EXPRESSION, WHICH MIGHT IMPACT EPIGENETIC REGULATION PROCESSES, LEADING TO ACCELERATED CELL AGEING AND INFLAMMATION, OR THE OCCURRENCE OF MALIGNANT TRANSFORMATION. 2023 14 3591 28 IMPAIRED ONE CARBON METABOLISM AND DNA METHYLATION IN ALCOHOL TOXICITY. EXCESSIVE ALCOHOL CONSUMPTION IS A PROMINENT PROBLEM AND ONE OF THE MAJOR CAUSES OF MORTALITY AND MORBIDITY AROUND THE WORLD. LONG-TERM, HEAVY ALCOHOL CONSUMPTION IS ASSOCIATED WITH A NUMBER OF DELETERIOUS HEALTH CONSEQUENCES, SUCH AS CANCER, HEART AND LIVER DISEASE, A VARIETY OF NEUROLOGICAL, COGNITIVE, AND BEHAVIORAL DEFICITS. ALCOHOL CONSUMPTION IS ALSO ASSOCIATED WITH DEVELOPMENTAL DEFECTS. THE CAUSES OF ALCOHOL-INDUCED TOXICITY ARE PRESENTLY UNCLEAR. ONE OF THE MECHANISMS UNDERLYING ALCOHOL TOXICITY HAS TO DO WITH ITS INTERACTION WITH FOLIC ACID/HOMOCYSTEINE OR ONE-CARBON METABOLISM (OCM). OCM IS A MAJOR DONOR OF METHYL GROUPS FOR METHYLATION, PARTICULARLY DNA METHYLATION CRITICAL FOR EPIGENETIC REGULATION OF GENE EXPRESSION, AND ITS DISTURBANCE MAY COMPROMISE DNA METHYLATION, THEREBY AFFECTING GENE EXPRESSION. OCM DISTURBANCE MEDIATED BY NUTRIENT DEFICITS IS A WELL-KNOWN RISK FACTOR FOR VARIOUS DISORDERS AND DEVELOPMENTAL DEFECTS (E.G., NEURAL TUBE DEFECTS). IN THIS REVIEW, WE SUMMARIZE THE ROLE OF OCM DISTURBANCE AND ASSOCIATED EPIGENETIC ABERRATIONS IN CHRONIC ALCOHOL-INDUCED TOXICITY. IN THIS REVIEW, WE SUMMARIZE THE ROLE OF ONE-CARBON METABOLISM (OCM) ABERRATIONS IN CHRONIC ALCOHOL-INDUCED TOXICITY. OCM IS A MAJOR DONOR OF METHYL GROUPS FOR METHYLATION REACTIONS, PARTICULARLY DNA METHYLATION CRITICAL FOR EPIGENETIC REGULATION OF GENE EXPRESSION. ALCOHOL INTERFERENCE WITH OCM AND CONSEQUENT REDUCED AVAILABILITY OF METHYL GROUPS, IMPROPER DNA METHYLATION, AND ABERRANT GENE EXPRESSION CAN PLAY A CAUSATIVE ROLE IN ALCOHOL TOXICITY. 2014 15 2967 38 GENETIC AND EPIGENETIC REGULATION OF CATECHOL-O-METHYLTRANSFERASE IN RELATION TO INFLAMMATION IN CHRONIC FATIGUE SYNDROME AND FIBROMYALGIA. BACKGROUND: CATECHOL-O-METHYLTRANSFERASE (COMT) HAS BEEN SHOWN TO INFLUENCE CLINICAL PAIN, DESCENDING MODULATION, AND EXERCISE-INDUCED SYMPTOM WORSENING. COMT REGULATES NOCICEPTIVE PROCESSING AND INFLAMMATION, KEY PATHOPHYSIOLOGICAL FEATURES OF CHRONIC FATIGUE SYNDROME AND FIBROMYALGIA (CFS/FM). WE AIMED TO DETERMINE THE INTERACTIONS BETWEEN GENETIC AND EPIGENETIC MECHANISMS REGULATING COMT AND ITS INFLUENCE ON INFLAMMATORY MARKERS AND SYMPTOMS IN PATIENTS WITH CFS/FM. METHODS: A CASE-CONTROL STUDY WITH REPEATED-MEASURES DESIGN WAS USED TO REDUCE THE CHANCE OF FALSE POSITIVE AND INCREASE THE POWER OF OUR FINDINGS. FIFTY-FOUR PARTICIPANTS (28 PATIENTS WITH CFS/FM AND 26 CONTROLS) WERE ASSESSED TWICE WITHIN 4 DAYS. THE ASSESSMENT INCLUDED CLINICAL QUESTIONNAIRES, NEUROPHYSIOLOGICAL ASSESSMENT (PAIN THRESHOLDS, TEMPORAL SUMMATION, AND CONDITIONED PAIN MODULATION), AND BLOOD WITHDRAWAL IN ORDER TO ASSESS RS4818, RS4633, AND RS4680 COMT POLYMORPHISMS AND PERFORM HAPLOTYPE ESTIMATION, DNA METHYLATION IN THE COMT GENE (BOTH MB-COMT AND S-COMT PROMOTERS), AND CYTOKINE EXPRESSION (TNF-ALPHA, IFN-GAMMA, IL-6, AND TGF-BETA). RESULTS: COMT HAPLOTYPES WERE ASSOCIATED WITH DNA METHYLATION IN THE S-COMT PROMOTER, TGF-BETA EXPRESSION, AND SYMPTOMS. HOWEVER, THIS WAS NOT SPECIFIC FOR ONE CONDITION. SIGNIFICANT BETWEEN-GROUP DIFFERENCES WERE FOUND FOR INCREASED DNA METHYLATION IN THE MB-COMT PROMOTER AND DECREASED IFN-GAMMA EXPRESSION IN PATIENTS. DISCUSSION: OUR RESULTS ARE CONSISTENT WITH BASIC AND CLINICAL RESEARCH, PROVIDING INTERESTING INSIGHTS INTO GENETIC-EPIGENETIC REGULATORY MECHANISMS. MB-COMT DNA METHYLATION MIGHT BE AN INDEPENDENT FACTOR CONTRIBUTING TO THE PATHOPHYSIOLOGY OF CFS/FM. FURTHER RESEARCH ON DNA METHYLATION IN COMPLEX CONDITIONS SUCH AS CFS/FM IS WARRANTED. WE RECOMMEND FUTURE RESEARCH TO EMPLOY A REPEATED-MEASURE DESIGN TO CONTROL FOR BIOMARKERS VARIABILITY AND WITHIN-SUBJECT CHANGES. 2022 16 3093 32 GENOMIC AND EPIGENOMIC RESPONSES TO CHRONIC STRESS INVOLVE MIRNA-MEDIATED PROGRAMMING. STRESS REPRESENTS A CRITICAL INFLUENCE ON MOTOR SYSTEM FUNCTION AND HAS BEEN SHOWN TO IMPAIR MOVEMENT PERFORMANCE. WE HYPOTHESIZED THAT STRESS-INDUCED MOTOR IMPAIRMENTS ARE DUE TO BRAIN-SPECIFIC CHANGES IN MIRNA AND PROTEIN-ENCODING GENE EXPRESSION. HERE WE SHOW A CAUSAL LINK BETWEEN STRESS-INDUCED MOTOR IMPAIRMENT AND ASSOCIATED GENETIC AND EPIGENETIC RESPONSES IN RELEVANT CENTRAL MOTOR AREAS IN A RAT MODEL. EXPOSURE TO TWO WEEKS OF MILD RESTRAINT STRESS ALTERED THE EXPRESSION OF 39 GENES AND NINE MIRNAS IN THE CEREBELLUM. IN LINE WITH PERSISTENT BEHAVIOURAL IMPAIRMENTS, SOME CHANGES IN GENE AND MIRNA EXPRESSION WERE RESISTANT TO RECOVERY FROM STRESS. INTERESTINGLY, STRESS UP-REGULATED THE EXPRESSION OF ADIPOQ AND PROLACTIN RECEPTOR MRNAS IN THE CEREBELLUM. STRESS ALSO ALTERED THE EXPRESSION OF PRLR, MIR-186, AND MIR-709 IN HIPPOCAMPUS AND PREFRONTAL CORTEX. IN ADDITION, OUR FINDINGS DEMONSTRATE THAT MIR-186 TARGETS THE GENE EPS15. FURTHERMORE, WE FOUND AN AGE-DEPENDENT INCREASE IN EPHRINB3 AND GABAA4 RECEPTORS. THESE DATA SHOW THAT EVEN MILD STRESS RESULTS IN SUBSTANTIAL GENOMIC AND EPIGENOMIC CHANGES INVOLVING MIRNA EXPRESSION AND ASSOCIATED GENE TARGETS IN THE MOTOR SYSTEM. THESE FINDINGS SUGGEST A CENTRAL ROLE OF MIRNA-REGULATED GENE EXPRESSION IN THE STRESS RESPONSE AND IN ASSOCIATED NEUROLOGICAL FUNCTION. 2012 17 3465 49 HYPOTHESIS: REGULATION OF NEUROPLASTICITY MAY INVOLVE I-MOTIF AND G-QUADRUPLEX DNA FORMATION MODULATED BY EPIGENETIC MECHANISMS. RECENT STUDIES DEMONSTRATED THE EXISTENCE IN VIVO OF VARIOUS FUNCTIONAL DNA STRUCTURES THAT DIFFER FROM THE DOUBLE HELIX. THE G-QUADRUPLEX (G4) AND INTERCALATED MOTIF (I-MOTIF OR IM) DNA STRUCTURES ARE FORMED AS KNOTS WHERE, CORRESPONDINGLY, GUANINES OR CYTOSINES ON THE SAME STRAND OF DNA BIND TO EACH OTHER. THERE ARE GROUNDS TO BELIEVE THAT G4 AND IM SEQUENCES PLAY A SIGNIFICANT ROLE IN REGULATING GENE EXPRESSION CONSIDERING THEIR TENDENCY TO BE FOUND IN OR NEAR REGULATORY SITES (SUCH AS PROMOTERS, ENHANCERS, AND TELOMERES) AS WELL AS THE CORRELATION BETWEEN THE PREVALENCE OF G4 OR IM CONFORMATIONS AND SPECIFIC PHASES OF CELL CYCLE. NOTABLY, G4 AND IM CAPABLE SEQUENCES TEND TO BE FOUND ON THE OPPOSITE STRANDS OF THE SAME DNA SITE WITH AT MOST ONE OF THE TWO STRUCTURES FORMED AT ANY GIVEN TIME. THE RECENT EVIDENCE THAT K(+), MG(2+) CONCENTRATIONS DIRECTLY AFFECT IM FORMATION (AND LIKELY G4 FORMATION INDIRECTLY) LEAD US TO BELIEVE THAT THESE STRUCTURES MAY PLAY A MAJOR ROLE IN SYNAPTIC PLASTICITY OF NEURONS, AND, THEREFORE, IN A VARIETY OF CENTRAL NERVOUS SYSTEM (CNS) FUNCTIONS INCLUDING MEMORY, LEARNING, HABITUAL BEHAVIORS, PAIN PERCEPTION AND OTHERS. FURTHERMORE, EPIGENETIC MECHANISMS, WHICH HAVE AN IMPORTANT ROLE IN SYNAPTIC PLASTICITY AND MEMORY FORMATION, WERE ALSO SHOWN TO INFLUENCE FORMATION AND STABILITY OF G4S AND IMS. OUR HYPOTHESIS IS THAT NON-CANONICAL DNA AND RNA STRUCTURES COULD BE AN INTEGRAL PART OF NEUROPLASTICITY CONTROL VIA GENE EXPRESSION REGULATION AT THE LEVEL OF TRANSCRIPTION, TRANSLATION AND SPLICING. WE PROPOSE THAT THE REGULATORY ACTIVITY OF DNA IM AND G4 STRUCTURES IS MODULATED BY DNA METHYLATION/DEMETHYLATION OF THE IM AND/OR G4 SEQUENCES, WHICH FACILITATES THE SWITCH BETWEEN CANONICAL AND NON-CANONICAL CONFORMATION. OTHER NEURONAL MECHANISMS INTERACTING WITH THE FORMATION AND REGULATORY ACTIVITY OF NON-CANONICAL DNA AND RNA STRUCTURES, PARTICULARLY G4, IM AND TRIPLEXES, MAY INVOLVE MICRORNAS AS WELL AS ION AND PROTON FLUXES. WE ARE PROPOSING EXPERIMENTS IN ACUTE BRAIN SLICES AND IN VIVO TO TEST OUR HYPOTHESIS. THE PROPOSED STUDIES WOULD PROVIDE NEW INSIGHTS INTO FUNDAMENTAL NEURONAL MECHANISMS IN HEALTH AND DISEASE AND POTENTIALLY OPEN NEW AVENUES FOR TREATING MENTAL HEALTH DISORDERS. 2019 18 660 34 BLOOD LEVELS OF T-CELL RECEPTOR EXCISION CIRCLES (TRECS) PROVIDE AN INDEX OF EXPOSURE TO TRAUMATIC STRESS IN MICE AND HUMANS. EXPOSURE TO STRESS TRIGGERS BIOLOGICAL CHANGES THROUGHOUT THE BODY. ACCUMULATING EVIDENCE INDICATES THAT ALTERATIONS IN IMMUNE SYSTEM FUNCTION ARE ASSOCIATED WITH THE DEVELOPMENT OF STRESS-ASSOCIATED ILLNESSES SUCH AS MAJOR DEPRESSIVE DISORDER AND POST-TRAUMATIC STRESS DISORDER, INCREASING INTEREST IN IDENTIFYING IMMUNE MARKERS THAT PROVIDE INSIGHT INTO MENTAL HEALTH. RECOMBINATION EVENTS DURING T-CELL RECEPTOR REARRANGEMENT AND T-CELL MATURATION IN THE THYMUS PRODUCE CIRCULAR DNA FRAGMENTS CALLED T-CELL RECEPTOR EXCISION CIRCLES (TRECS) THAT CAN BE UTILIZED AS INDICATORS OF THYMIC FUNCTION AND NUMBERS OF NEWLY EMIGRATING T-CELLS. GIVEN DATA SUGGESTING THAT STRESS AFFECTS THYMUS FUNCTION, WE EXAMINED WHETHER BLOOD LEVELS OF TRECS MIGHT SERVE AS A QUANTITATIVE PERIPHERAL INDEX OF CUMULATIVE STRESS EXPOSURE AND ITS PHYSIOLOGICAL CORRELATES. WE HYPOTHESIZED THAT CHRONIC STRESS EXPOSURE WOULD COMPROMISE THYMUS FUNCTION AND PRODUCE CORRESPONDING DECREASES IN LEVELS OF TRECS. IN MALE MICE, EXPOSURE TO CHRONIC SOCIAL DEFEAT STRESS (CSDS) PRODUCED THYMIC INVOLUTION, ADRENAL HYPERTROPHY, AND DECREASED LEVELS OF TRECS IN BLOOD. EXTENDING THESE STUDIES TO HUMANS REVEALED ROBUST INVERSE CORRELATIONS BETWEEN LEVELS OF CIRCULATING TRECS AND CHILDHOOD EMOTIONAL AND PHYSICAL ABUSE. CELL-TYPE SPECIFIC ANALYSES ALSO REVEALED ASSOCIATIONS BETWEEN TREC LEVELS AND BLOOD CELL COMPOSITION, AS WELL AS CELL-TYPE SPECIFIC METHYLATION CHANGES IN CD4T + AND CD8T + CELLS. ADDITIONALLY, TREC LEVELS CORRELATED WITH EPIGENETIC AGE ACCELERATION, A COMMON BIOMARKER OF STRESS EXPOSURE. OUR FINDINGS DEMONSTRATE ALIGNMENT BETWEEN FINDINGS IN MICE AND HUMANS AND SUGGEST THAT BLOOD-BORNE TRECS ARE A TRANSLATIONALLY-RELEVANT BIOMARKER THAT CORRELATES WITH, AND PROVIDES INSIGHT INTO, THE CUMULATIVE PHYSIOLOGICAL AND IMMUNE-RELATED IMPACTS OF STRESS EXPOSURE IN MAMMALS. 2022 19 6137 33 THE EPIGENETICS OF PSYCHOSIS: A STRUCTURED REVIEW WITH REPRESENTATIVE LOCI. THE EVIDENCE FOR AN ENVIRONMENTAL COMPONENT IN CHRONIC PSYCHOTIC DISORDERS IS STRONG AND RESEARCH ON THE EPIGENETIC MANIFESTATIONS OF THESE ENVIRONMENTAL IMPACTS HAS COMMENCED IN EARNEST. IN REVIEWING THIS RESEARCH, THE FOCUS IS ON THREE GENES AS MODELS FOR DIFFERENTIAL METHYLATION, MCHR1, AKT1 AND TDO2, EACH OF WHICH HAVE BEEN INVESTIGATED FOR GENETIC ASSOCIATION WITH PSYCHOTIC DISORDERS. ENVIRONMENTAL FACTORS ASSOCIATED WITH PSYCHOTIC DISORDERS, AND WHICH INTERACT WITH THESE MODEL GENES, ARE EXPLORED IN DEPTH. THE LOCATION OF TRANSCRIPTION FACTOR MOTIFS RELATIVE TO KEY METHYLATION SITES IS EVALUATED FOR PREDICTED GENE EXPRESSION RESULTS, AND FOR OTHER SITES, EVIDENCE IS PRESENTED FOR METHYLATION DIRECTING ALTERNATIVE SPLICING. EXPERIMENTAL RESULTS FROM KEY STUDIES SHOW DIFFERENTIAL METHYLATION: FOR MCHR1, IN PSYCHOSIS CASES VERSUS CONTROLS; FOR AKT1, AS A PRE-EXISTING METHYLATION PATTERN INFLUENCING BRAIN ACTIVATION FOLLOWING ACUTE ADMINISTRATION OF A PSYCHOSIS-ELICITING ENVIRONMENTAL STIMULUS; AND FOR TDO2, IN A PATTERN ASSOCIATED WITH A DEVELOPMENTAL FACTOR OF RISK FOR PSYCHOSIS, IN ALL CASES THE PREDICTED EXPRESSION IMPACT BEING HIGHLY DEPENDENT ON LOCATION. METHYLATION INDUCED BY SMOKING, A CONFOUNDING VARIABLE, EXHIBITS AN INTRIGUING PATTERN FOR ALL THREE GENES. FINALLY, HOW DIFFERENTIAL METHYLATION MESHES WITH DARWINIAN PRINCIPLES IS EXAMINED, IN PARTICULAR AS IT RELATES TO THE "FLEXIBLE STEM" THEORY OF EVOLUTION. 2022 20 1312 40 DELETERIOUS EFFECTS OF CHRONIC FOLATE DEFICIENCY IN THE TS65DN MOUSE MODEL OF DOWN SYNDROME. FOLATE IS AN IMPORTANT B VITAMIN NATURALLY FOUND IN THE HUMAN DIET AND PLAYS A CRITICAL ROLE IN METHYLATION OF NUCLEIC ACIDS. INDEED, ABNORMALITIES IN THIS MAJOR EPIGENETIC MECHANISM PLAY A PIVOTAL ROLE IN THE PATHOGENESIS OF COGNITIVE DEFICIT AND INTELLECTUAL DISABILITY IN HUMANS. THE MOST COMMON CAUSE OF COGNITIVE DYSFUNCTION IN CHILDREN IS DOWN SYNDROME (DS). SINCE FOLATE DEFICIENCY IS VERY COMMON AMONG THE PEDIATRIC POPULATION, WE QUESTIONED WHETHER CHRONIC FOLATE DEFICIENCY (CFD) EXACERBATES COGNITIVE DYSFUNCTION IN A MOUSE MODEL OF DS. TO TEST THIS, ADULT TS65DN MICE AND THEIR DISOMIC LITTERMATES WERE CHRONICALLY FED A DIET FREE OF FOLIC ACID WHILE PREVENTING ENDOGENOUS PRODUCTION OF FOLATE IN THE DIGESTIVE TRACT FOR A PERIOD OF 8 WEEKS. OUR RESULTS SHOW THAT THE TS65DN MOUSE MODEL OF DS WAS SIGNIFICANTLY MORE VULNERABLE TO CFD IN TERMS OF PLASMA HOMOCYSTEINE AND N5-METHYLTETRAHYDROFOLATE (5-MTHF) LEVELS. IMPORTANTLY, THESE CHANGES WERE LINKED TO DEGENERATIVE ALTERATIONS IN HIPPOCAMPAL DENDRITIC MORPHOLOGY AND IMPAIRED NEST BUILDING BEHAVIOR IN TS65DN MICE. BASED ON OUR RESULTS, A RIGOROUS EXAMINATION OF FOLATE INTAKE AND ITS METABOLISM IN INDIVIDUALS WITH DS IS WARRANTED. 2017