1 579 163 BEHAVIORAL AND MOLECULAR NEUROEPIGENETIC ALTERATIONS IN PRENATALLY STRESSED MICE: RELEVANCE FOR THE STUDY OF CHROMATIN REMODELING PROPERTIES OF ANTIPSYCHOTIC DRUGS. WE HAVE RECENTLY REPORTED THAT MICE BORN FROM DAMS STRESSED DURING PREGNANCY (PRS MICE), IN ADULTHOOD, HAVE BEHAVIORAL DEFICITS REMINISCENT OF BEHAVIORS OBSERVED IN SCHIZOPHRENIA (SZ) AND BIPOLAR (BP) DISORDER PATIENTS. FURTHERMORE, WE HAVE SHOWN THAT THE FRONTAL CORTEX (FC) AND HIPPOCAMPUS OF ADULT PRS MICE, LIKE THAT OF POSTMORTEM CHRONIC SZ PATIENTS, ARE CHARACTERIZED BY INCREASES IN DNA-METHYLTRANSFERASE 1 (DNMT1), TEN-ELEVEN METHYLCYTOSINE DIOXYGENASE 1 (TET1) AND EXHIBIT AN ENRICHMENT OF 5-METHYLCYTOSINE (5MC) AND 5-HYDROXYMETHYLCYTOSINE (5HMC) AT NEOCORTICAL GABAERGIC AND GLUTAMATERGIC GENE PROMOTERS. HERE, WE SHOW THAT THE BEHAVIORAL DEFICITS AND THE INCREASED 5MC AND 5HMC AT GLUTAMIC ACID DECARBOXYLASE 67 (GAD1), REELIN (RELN) AND BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) PROMOTERS AND THE REDUCED EXPRESSION OF THE MESSENGER RNAS (MRNAS) AND PROTEINS CORRESPONDING TO THESE GENES IN FC OF ADULT PRS MICE IS REVERSED BY TREATMENT WITH CLOZAPINE (5 MG KG(-1) TWICE A DAY FOR 5 DAYS) BUT NOT BY HALOPERIDOL (1 MG KG(-1) TWICE A DAY FOR 5 DAYS). INTERESTINGLY, CLOZAPINE HAD NO EFFECT ON EITHER THE BEHAVIOR, PROMOTER METHYLATION OR THE EXPRESSION OF THESE MRNAS AND PROTEINS WHEN ADMINISTERED TO OFFSPRING OF NONSTRESSED PREGNANT MICE. CLOZAPINE, BUT NOT HALOPERIDOL, REDUCED THE ELEVATED LEVELS OF DNMT1 AND TET1, AS WELL AS THE ELEVATED LEVELS OF DNMT1 BINDING TO GAD1, RELN AND BDNF PROMOTERS IN PRS MICE SUGGESTING THAT CLOZAPINE, UNLIKE HALOPERIDOL, MAY LIMIT DNA METHYLATION BY INTERFERING WITH DNA METHYLATION DYNAMICS. WE CONCLUDE THAT THE PRS MOUSE MODEL MAY BE USEFUL PRECLINICALLY IN SCREENING FOR THE POTENTIAL EFFICACY OF ANTIPSYCHOTIC DRUGS ACTING ON ALTERED EPIGENETIC MECHANISMS. FURTHERMORE, PRS MICE MAY BE INVALUABLE FOR UNDERSTANDING THE ETIOPATHOGENESIS OF SZ AND BP DISORDER AND FOR PREDICTING TREATMENT RESPONSES AT EARLY STAGES OF THE ILLNESS ALLOWING FOR EARLY DETECTION AND REMEDIAL INTERVENTION. 2016 2 1875 46 EMERGING ROLE OF ONE-CARBON METABOLISM AND DNA METHYLATION ENRICHMENT ON DELTA-CONTAINING GABAA RECEPTOR EXPRESSION IN THE CEREBELLUM OF SUBJECTS WITH ALCOHOL USE DISORDERS (AUD). BACKGROUND: CEREBELLUM IS AN AREA OF THE BRAIN PARTICULARLY SENSITIVE TO THE EFFECTS OF ACUTE AND CHRONIC ALCOHOL CONSUMPTION. ALCOHOL EXPOSURE DECREASES CEREBELLAR PURKINJE CELL OUTPUT BY INCREASING GABA RELEASE FROM GOLGI CELLS ONTO EXTRASYNAPTIC ALPHA6/DELTA-CONTAINING GABAA RECEPTORS LOCATED ON GLUTAMATERGIC GRANULE CELLS. HERE, WE STUDIED WHETHER CHRONIC ALCOHOL CONSUMPTION INDUCES CHANGES IN GABAA RECEPTOR SUBUNIT EXPRESSION AND WHETHER THESE CHANGES ARE ASSOCIATED WITH ALTERATIONS IN EPIGENETIC MECHANISMS VIA DNA METHYLATION. METHODS: WE USED A COHORT OF POSTMORTEM CEREBELLUM FROM CONTROL AND CHRONIC ALCOHOLICS, HERE DEFINED AS ALCOHOL USE DISORDERS SUBJECTS (N=25/GROUP). S-ADENOSYL-METHIONINE/S-ADENOSYL-HOMOCYSTEINE WERE MEASURED BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY. MRNA LEVELS OF VARIOUS GENES WERE ASSESSED BY REVERSE TRANSCRIPTASE-QUANTITATIVE POLYMERASE CHAIN REACTION. PROMOTER METHYLATION ENRICHMENT WAS ASSESSED USING METHYLATED DNA IMMUNOPRECIPITATION AND HYDROXY-METHYLATED DNA IMMUNOPRECIPITATION ASSAYS. RESULTS: MRNAS ENCODING KEY ENZYMES OF 1-CARBON METABOLISM THAT DETERMINE THE S-ADENOSYL-METHIONINE/S-ADENOSYL-HOMOCYSTEINE RATIO WERE INCREASED, INDICATING HIGHER "METHYLATION INDEX" IN ALCOHOL USE DISORDER SUBJECTS. WE FOUND THAT INCREASED METHYLATION OF THE PROMOTER OF THE DELTA SUBUNIT GABAA RECEPTOR WAS ASSOCIATED WITH REDUCED MRNA AND PROTEIN LEVELS IN THE CEREBELLUM OF ALCOHOL USE DISORDER SUBJECTS. NO CHANGES WERE OBSERVED IN ALPHA1- OR ALPHA6-CONTAINING GABAA RECEPTOR SUBUNITS. THE EXPRESSION OF DNA-METHYLTRANSFERASES (1, 3A, AND 3B) WAS UNALTERED, WHEREAS THE MRNA LEVEL OF TET1, WHICH PARTICIPATES IN THE DNA DEMETHYLATION PATHWAY, WAS DECREASED. HENCE, INCREASED METHYLATION OF THE DELTA SUBUNIT GABAA RECEPTOR PROMOTER MAY RESULT FROM ALCOHOL-INDUCED REDUCTION OF DNA DEMETHYLATION. CONCLUSION: TOGETHER, THESE RESULTS SUPPORT THE HYPOTHESIS THAT ABERRANT DNA METHYLATION PATHWAYS MAY BE INVOLVED IN CEREBELLAR PATHOPHYSIOLOGY OF ALCOHOLISM. FURTHERMORE, THIS WORK PROVIDES NOVEL EVIDENCE FOR A CENTRAL ROLE OF DNA METHYLATION MECHANISMS IN THE ALCOHOL-INDUCED NEUROADAPTIVE CHANGES OF HUMAN CEREBELLAR GABAA RECEPTOR FUNCTION. 2017 3 1299 30 DECREASED REELIN EXPRESSION IN THE LEFT PREFRONTAL CORTEX (BA9) IN CHRONIC SCHIZOPHRENIA PATIENTS. BACKGROUND: REELIN IS UNDER EPIGENETIC CONTROL AND HAS BEEN REPORTED TO BE DECREASED IN CORTICAL REGIONS IN SCHIZOPHRENIA. METHODS: TO ESTABLISH IF EXPRESSION OF REELIN IS ALTERED IN SPECIFIC CORTICAL, HIPPOCAMPAL OR THALAMIC REGIONS OF SCHIZOPHRENIA PATIENTS, WE MEASURED GENE EXPRESSION OF REELIN IN A POSTMORTEM STUDY OF ELDERLY PATIENTS WITH SCHIZOPHRENIA AND NON-AFFECTED CONTROLS IN BOTH HEMISPHERES DIFFERENTIATING BETWEEN GRAY AND WHITE MATTER. WE COMPARED CEREBRAL POSTMORTEM SAMPLES (DORSOLATERAL PREFRONTAL CORTEX BA9 AND BA46, SUPERIOR TEMPORAL CORTEX BA22, ENTORHINAL CORTEX BA28, SENSORIC CORTEX BA1-3, HIPPOCAMPUS, CA4, MEDIODORSAL NUCLEUS OF THE THALAMUS) FROM 12 SCHIZOPHRENIA PATIENTS WITH 13 NORMAL SUBJECTS INVESTIGATING GENE EXPRESSION OF REELIN IN THE GRAY AND WHITE MATTER OF BOTH HEMISPHERES BY IN SITU-HYBRIDIZATION. RESULTS: THE LEFT PREFRONTAL AREA (BA9) OF SCHIZOPHRENIA PATIENTS REVEALED A DECREASED EXPRESSION OF REELIN-MRNA OF 29.1% IN THE WHITE (P = 0.022) AND 13.6% IN THE GRAY MATTER (P = 0.007) COMPARED TO THE CONTROL GROUP. NONE OF THE OTHER REGIONS EXAMINED SHOWED ANY STATISTICALLY SIGNIFICANT DIFFERENCES. CONCLUSION: SINCE REELIN IS RESPONSIBLE FOR MIGRATION AND SYNAPSE FORMATION, THE DECREASED GENE EXPRESSION OF REELIN IN THE LEFT PREFRONTAL AREA OF SCHIZOPHRENIA PATIENTS POINTS TO NEURODEVELOPMENTAL DEFICITS IN NEURONAL MIGRATION AND SYNAPTIC PLASTICITY. HOWEVER, OUR STUDY GROUP WAS SMALL, AND RESULTS SHOULD BE VERIFIED USING LARGER SAMPLES. 2012 4 1610 53 DNA METHYLATION/DEMETHYLATION NETWORK EXPRESSION IN PSYCHOTIC PATIENTS WITH A HISTORY OF ALCOHOL ABUSE. BACKGROUND: RECENT STUDIES SUGGEST THAT PROTRACTED AND EXCESSIVE ALCOHOL USE INDUCES AN EPIGENETIC DYSREGULATION IN HUMAN AND RODENT BRAINS. WE RECENTLY REPORTED THAT DNA METHYLATION DYNAMICS ARE ALTERED IN BRAINS OF PSYCHOTIC (PS) PATIENTS, INCLUDING SCHIZOPHRENIA AND BIPOLAR DISORDER PATIENTS. BECAUSE PS PATIENTS ARE OFTEN COMORBID WITH CHRONIC ALCOHOL ABUSE, WE EXAMINED WHETHER THE ALTERED EXPRESSION OF MULTIPLE MEMBERS OF THE DNA METHYLATION/DEMETHYLATION NETWORK OBSERVED IN POSTMORTEM BRAINS OF PS PATIENTS WAS MODIFIED IN PS PATIENTS WITH A HISTORY OF CHRONIC ALCOHOL ABUSE. METHODS: DNA-METHYLTRANSFERASE-1 (DNMT1) MRNA-POSITIVE NEURONS WERE COUNTED IN SITU IN PREFRONTAL CORTEX SAMPLES OBTAINED FROM THE HARVARD BRAIN TISSUE RESOURCE CENTER, BELMONT, MA. 10-11-TRANSLOCATION (TETS 1, 2, 3), APOLIPOPROTEIN B EDITING COMPLEX ENZYME (APOBEC-3C), GROWTH AND DNA-DAMAGE-INDUCIBLE PROTEIN 45BETA (GADD45BETA), AND METHYL-BINDING DOMAIN PROTEIN-4 (MBD4) MRNAS WERE MEASURED BY QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION IN INFERIOR PARIETAL CORTICAL LOBULE SAMPLES OBTAINED FROM THE STANLEY FOUNDATION NEUROPATHOLOGY CONSORTIUM, BETHESDA, MD. RESULTS: WE OBSERVED AN INCREASE IN DNMT1 MRNA-POSITIVE NEURONS IN PS PATIENTS COMPARED WITH NON-PS SUBJECTS. IN ADDITION, THERE WAS A PRONOUNCED DECREASE IN APOBEC-3C AND A PRONOUNCED INCREASE IN GADD45BETA AND TET1 MRNAS IN PS PATIENTS WITH NO HISTORY OF ALCOHOL ABUSE. IN PS PATIENTS WITH A HISTORY OF CHRONIC ALCOHOL ABUSE, THE NUMBERS OF DNMT1-POSITIVE NEURONS WERE NOT INCREASED SIGNIFICANTLY. FURTHERMORE, THE DECREASE IN APOBEC-3C MRNA WAS LESS PRONOUNCED, WHILE THE INCREASE IN TET1 MRNA HAD A TENDENCY TO BE POTENTIATED IN THOSE PS PATIENTS THAT WERE CHRONIC ALCOHOL ABUSERS. GADD45BETA AND MBD4 MRNAS WERE NOT INFLUENCED BY ALCOHOL ABUSE. THE EFFECT OF CHRONIC ALCOHOL ABUSE ON DNA METHYLATION/DEMETHYLATION NETWORK ENZYMES CANNOT BE ATTRIBUTED TO CONFOUNDING DEMOGRAPHIC VARIABLES OR TO THE TYPE AND DOSE OF MEDICATION USED. CONCLUSIONS: BASED ON THESE RESULTS, WE HYPOTHESIZE THAT PS PATIENTS MAY ABUSE ALCOHOL AS A POTENTIAL ATTEMPT AT SELF-MEDICATION TO NORMALIZE ALTERED DNA METHYLATION/DEMETHYLATION NETWORK PATHWAYS. HOWEVER, BEFORE ACCEPTING THIS CONCLUSION, WE NEED TO STUDY ALTERATIONS IN THE DNA METHYLATION/DEMETHYLATION PATHWAYS AND THE DNA METHYLATION DYNAMICS IN A SUBSTANTIAL NUMBER OF ALCOHOLIC PS AND NON-PS PATIENTS. ADDITIONAL INVESTIGATION MAY ALSO BE NECESSARY TO DETERMINE WHETHER THE ALTERED DNA METHYLATION DYNAMICS ARE DIRECT OR THE CONSEQUENCE OF AN INDIRECT INTERACTION OF ALCOHOL WITH THE NEUROPATHOGENETIC MECHANISMS UNDERLYING PSYCHOSIS. 2013 5 4390 62 MODELING THE MOLECULAR EPIGENETIC PROFILE OF PSYCHOSIS IN PRENATALLY STRESSED MICE. BASED ON POSTMORTEM BRAIN STUDIES, OUR OVERARCHING EPIGENETIC HYPOTHESIS IS THAT CHRONIC SCHIZOPHRENIA (SZ) IS A PSYCHOPATHOLOGICAL CONDITION INVOLVING DYSREGULATION OF THE DYNAMIC EQUILIBRIUM AMONG DNA METHYLATION/DEMETHYLATION NETWORK COMPONENTS AND THE EXPRESSION OF SZ TARGET GENES, INCLUDING GABAERGIC AND GLUTAMATERGIC GENES. SZ HAS A NATURAL COURSE, STARTING WITH A PRODROMAL PHASE, A FIRST EPISODE THAT OCCURS IN ADOLESCENTS OR IN YOUNG ADULTS, AND LATER DETERIORATION OVER THE ADULT YEARS. HENCE, THE EPIGENETIC STATUS AT EACH NEURODEVELOPMENTAL STAGE OF THE DISEASE CANNOT BE STUDIED JUST IN POSTMORTEM BRAIN OF CHRONIC SZ PATIENTS, BUT REQUIRES THE USE OF NEURODEVELOPMENTAL ANIMAL MODELS. WE HAVE DIRECTED THE FOCUS OF OUR RESEARCH TOWARD STUDYING THE EPIGENETIC SIGNATURE OF THE SZ BRAIN IN THE OFFSPRING OF DAMS STRESSED DURING PREGNANCY (PRS MICE). ADULT PRS MICE HAVE BEHAVIORAL DEFICITS REMINISCENT OF BEHAVIORS OBSERVED IN PSYCHOTIC PATIENTS. THE ADULT PRS BRAIN, LIKE THAT OF POSTMORTEM CHRONIC SZ PATIENTS, IS CHARACTERIZED BY A SIGNIFICANT INCREASE IN DNA METHYLTRANSFERASE 1, TET METHYLCYTOSINE DIOXYGENASE 1 (TET1), 5-METHYLCYTOSINE, AND 5-HYDROXYMETHYLCYTOSINE AT SZ CANDIDATE GENE PROMOTERS AND A REDUCTION IN THE EXPRESSION OF GLUTAMATERGIC AND GABAERGIC GENES. IN PRS MICE, MEASUREMENTS OF EPIGENETIC BIOMARKERS FOR SZ CAN BE ASSESSED AT DIFFERENT STAGES OF DEVELOPMENT WITH THE GOAL OF FURTHER ELUCIDATING THE PATHOPHYSIOLOGY OF THIS DISEASE AND PREDICTING TREATMENT RESPONSES AT SPECIFIC STAGES OF THE ILLNESS, WITH PARTICULAR ATTENTION TO EARLY DETECTION AND POSSIBLY EARLY INTERVENTION. 2014 6 2423 25 EPIGENETIC SIGNATURES OF SMOKING IN FIVE BRAIN REGIONS. (1) BACKGROUND: EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) IN PERIPHERAL BLOOD HAVE REPEATEDLY FOUND ASSOCIATIONS BETWEEN TOBACCO SMOKING AND ABERRANT DNA METHYLATION (DNAM), BUT LITTLE IS KNOWN ABOUT DNAM SIGNATURES OF SMOKING IN THE HUMAN BRAIN, WHICH MAY CONTRIBUTE TO THE PATHOPHYSIOLOGY OF ADDICTIVE BEHAVIOR OBSERVED IN CHRONIC SMOKERS. (2) METHODS: WE INVESTIGATED THE SIMILARITY OF DNAM SIGNATURES IN MATCHED BLOOD AND POSTMORTEM BRAIN SAMPLES (N = 10). IN ADDITION, WE PERFORMED EWASS IN FIVE BRAIN REGIONS BELONGING TO THE NEUROCIRCUITRY OF ADDICTION: ANTERIOR CINGULATE CORTEX (ACC), BRODMANN AREA 9, CAUDATE NUCLEUS, PUTAMEN, AND VENTRAL STRIATUM (N = 38-72). (3) RESULTS: CG15925993 WITHIN THE LOC339975 GENE WAS EPIGENOME-WIDE SIGNIFICANT IN THE ACC. OF 16 IDENTIFIED DIFFERENTIALLY METHYLATED REGIONS, TWO (PRSS50 AND LINC00612/A2M-AS1) OVERLAPPED BETWEEN MULTIPLE BRAIN REGIONS. FUNCTIONAL ENRICHMENT WAS DETECTED FOR BIOLOGICAL PROCESSES RELATED TO NEURONAL DEVELOPMENT, INFLAMMATORY SIGNALING AND IMMUNE CELL MIGRATION. ADDITIONALLY, OUR RESULTS INDICATE THE ASSOCIATION OF THE WELL-KNOWN AHRR CPG SITE CG05575921 WITH SMOKING IN THE BRAIN. (4) CONCLUSION: THE PRESENT STUDY PROVIDES FURTHER EVIDENCE OF THE STRONG RELATIONSHIP BETWEEN ABERRANT DNAM AND SMOKING. 2022 7 5498 33 REVIEW: DNA METHYLATION AND ALCOHOL USE DISORDERS: PROGRESS AND CHALLENGES. BACKGROUND AND OBJECTIVES: RISK FOR ALCOHOL USE DISORDERS (AUDS) IS INFLUENCED BY GENE-ENVIRONMENT INTERACTIONS. ENVIRONMENTAL FACTORS CAN AFFECT GENE EXPRESSION THROUGH EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION. THIS REVIEW OUTLINES THE FINDINGS REGARDING THE ASSOCIATION OF DNA METHYLATION AND AUDS. METHODS: WE SEARCHED PUBMED (BY APRIL 2016) AND IDENTIFIED 29 STUDIES THAT EXAMINED THE ASSOCIATION OF DNA METHYLATION AND AUDS. WE ALSO EVALUATED THE METHODS USED IN THESE STUDIES. RESULTS: TWO STUDIES DEMONSTRATED ELEVATED GLOBAL (REPETITIVE ELEMENT) DNA METHYLATION LEVELS IN AUD SUBJECTS. FIFTEEN CANDIDATE GENE STUDIES SHOWED HYPERMETHYLATION OF PROMOTER REGIONS OF SIX GENES (AVP, DNMT3B, HERP, HTR3A, OPRM1, AND SNCA) OR HYPOMETHYLATION OF THE GDAP1 PROMOTER REGION IN AUD SUBJECTS. FIVE GENOME-WIDE DNA METHYLATION STUDIES DEMONSTRATED WIDESPREAD DNA METHYLATION CHANGES ACROSS THE GENOME IN AUD SUBJECTS. SIX STUDIES SHOWED SIGNIFICANT CORRELATIONS OF DNA METHYLATION WITH GENE EXPRESSION IN AUD SUBJECTS. THREE STUDIES REVEALED INTERACTIVE EFFECTS OF GENETIC VARIATION AND DNA METHYLATION ON SUSCEPTIBILITY TO AUDS. MOST STUDIES ANALYZED AUD-ASSOCIATED DNA METHYLATION CHANGES IN THE PERIPHERAL BLOOD; A FEW STUDIES EXAMINED DNA METHYLATION CHANGES IN POSTMORTEM BRAINS OF AUD SUBJECTS. DISCUSSION AND CONCLUSIONS: CHRONIC ALCOHOL CONSUMPTION MAY RESULT IN DNA METHYLATION CHANGES, LEADING TO NEUROADAPTATIONS THAT MAY UNDERLIE SOME OF THE MECHANISMS OF AUD RISK AND PERSISTENCE. FUTURE STUDIES ARE NEEDED TO CONFIRM THE FEW EXISTING RESULTS, AND THEN TO ELUCIDATE WHETHER DNA METHYLATION CHANGES ARE THE CAUSE OR CONSEQUENCE OF AUDS. SCIENTIFIC SIGNIFICANCE: DNA METHYLATION PROFILES MAY BE USED TO ASSESS AUD STATUS OR MONITOR AUD TREATMENT RESPONSE. (AM J ADDICT 2017;26:502-515). 2017 8 2630 30 EPIGENOME-WIDE ASSOCIATION STUDY OF POSTTRAUMATIC STRESS DISORDER IDENTIFIES NOVEL LOCI IN U.S. MILITARY VETERANS. POSTTRAUMATIC STRESS DISORDER (PTSD) IS A CHRONIC AND DISABLING PSYCHIATRIC DISORDER PREVALENT IN MILITARY VETERANS. EPIGENETIC MECHANISMS HAVE BEEN IMPLICATED IN THE ETIOLOGY OF PTSD, WITH DNA METHYLATION BEING THE MOST STUDIED TO IDENTIFY NOVEL MOLECULAR BIOMARKERS ASSOCIATED WITH THIS DISORDER. WE PERFORMED ONE OF THE LARGEST SINGLE-SAMPLE EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) OF PTSD TO DATE. OUR SAMPLE INCLUDED 1135 MALE EUROPEAN-AMERICAN U.S. VETERANS WHO PARTICIPATED IN THE NATIONAL HEALTH AND RESILIENCE IN VETERANS STUDY (NHRVS). DNA WAS COLLECTED FROM SALIVA SAMPLES AND THE ILLUMINA HUMANMETHYLATION EPIC BEADCHIP WAS USED FOR THE METHYLATION ANALYSIS. PTSD WAS ASSESSED USING THE PTSD CHECKLIST. AN EWAS WAS CONDUCTED USING LINEAR REGRESSION ADJUSTED FOR AGE, CELL-TYPE PROPORTIONS, FIRST 10 PRINCIPAL COMPONENTS, AND SMOKING STATUS. AFTER BONFERRONI CORRECTION, WE IDENTIFIED SIX GENOME-WIDE SIGNIFICANT (GWS) CPG SITES ASSOCIATED WITH PAST-MONTH PTSD AND THREE CPGS WITH LIFETIME PTSD (P(RANGE) = 10(-10)-10(-8)). THESE CPG SITES MAP TO GENES INVOLVED IN IMMUNE FUNCTION, TRANSCRIPTION REGULATION, AXONAL GUIDANCE, CELL SIGNALING, AND PROTEIN BINDING. AMONG THESE, SENP7, WHICH IS INVOLVED IN TRANSCRIPTION REGULATION AND HAS BEEN LINKED TO RISK-TAKING BEHAVIOR AND ALCOHOL CONSUMPTION IN GENOME-WIDE ASSOCIATION STUDIES, REPLICATED IN AN INDEPENDENT VETERAN COHORT AND WAS DOWNREGULATED IN MEDIAL ORBITOFRONTAL CORTEX OF PTSD POSTMORTEM BRAIN TISSUE. THESE FINDINGS SUGGEST POTENTIAL EPIGENETIC BIOMARKERS OF PTSD THAT MAY HELP INFORM THE PATHOPHYSIOLOGY OF THIS DISORDER IN VETERANS AND OTHER TRAUMA-AFFECTED POPULATIONS. 2022 9 4236 32 METHYLATION OF THE TYROSINE HYDROXYLASE GENE IS DYSREGULATED BY COCAINE DEPENDENCE IN THE HUMAN STRIATUM. COCAINE DEPENDENCE IS A CHRONIC, RELAPSING DISORDER CAUSED BY LASTING CHANGES IN THE BRAIN. ANIMAL STUDIES HAVE IDENTIFIED COCAINE-RELATED ALTERATIONS IN STRIATAL DNA METHYLATION; HOWEVER, IT IS UNCLEAR HOW METHYLATION IS RELATED TO COCAINE DEPENDENCE IN HUMANS. WE GENERATED METHYLOMIC PROFILES OF THE NUCLEUS ACCUMBENS USING HUMAN POSTMORTEM BRAINS FROM A COHORT OF INDIVIDUALS WITH COCAINE DEPENDENCE AND HEALTHY CONTROLS (N = 25 PER GROUP). WE FOUND HYPERMETHYLATION IN A CLUSTER OF CPGS WITHIN THE GENE BODY OF TYROSINE HYDROXYLASE (TH), CONTAINING A PUTATIVE BINDING SITE FOR THE EARLY GROWTH RESPONSE 1 (EGR1) TRANSCRIPTION FACTOR, WHICH IS HYPERMETHYLATED IN THE CAUDATE NUCLEUS OF COCAINE-DEPENDENT INDIVIDUALS. WE REPLICATED THIS FINDING AND FOUND IT TO BE SPECIFIC TO STRIATAL NEURONAL NUCLEI. FURTHERMORE, THIS LOCUS DEMONSTRATES ENHANCER ACTIVITY WHICH IS ATTENUATED BY METHYLATION AND ENHANCED BY EGR1 OVEREXPRESSION. THESE RESULTS SUGGEST THAT COCAINE DEPENDENCE ALTERS THE EPIGENETIC REGULATION OF DOPAMINERGIC SIGNALING GENES. 2021 10 4848 33 OPIOID-INDUCED STRUCTURAL AND FUNCTIONAL PLASTICITY OF MEDIUM-SPINY NEURONS IN THE NUCLEUS ACCUMBENS. OPIOID USE DISORDER (OUD) IS A CHRONIC RELAPSING CLINICAL CONDITION WITH TREMENDOUS MORBIDITY AND MORTALITY THAT FREQUENTLY PERSISTS, DESPITE TREATMENT, DUE TO AN INDIVIDUAL'S UNDERLYING PSYCHOLOGICAL, NEUROBIOLOGICAL, AND GENETIC VULNERABILITIES. EVIDENCE SUGGESTS THAT THESE VULNERABILITIES MAY HAVE NEUROCHEMICAL, CELLULAR, AND MOLECULAR BASES. KEY NEUROPLASTIC EVENTS WITHIN THE MESOCORTICOLIMBIC SYSTEM THAT EMERGE THROUGH CHRONIC EXPOSURE TO OPIOIDS MAY HAVE A DETERMINATIVE INFLUENCE ON BEHAVIORAL SYMPTOMS ASSOCIATED WITH OUD. IN PARTICULAR, STRUCTURAL AND FUNCTIONAL ALTERATIONS IN THE DENDRITIC SPINES OF MEDIUM SPINY NEURONS (MSNS) WITHIN THE NUCLEUS ACCUMBENS (NAC) AND ITS DOPAMINERGIC PROJECTIONS FROM THE VENTRAL TEGMENTAL AREA (VTA) ARE BELIEVED TO FACILITATE THESE BEHAVIORAL SEQUELAE. ADDITIONALLY, GLUTAMATERGIC NEURONS FROM THE PREFRONTAL CORTEX, THE BASOLATERAL AMYGDALA, THE HIPPOCAMPUS, AND THE THALAMUS PROJECT TO THESE SAME MSNS, PROVIDING AN ENRICHED TARGET FOR SYNAPTIC PLASTICITY. HERE, WE REVIEW LITERATURE RELATED TO NEUROADAPTATIONS IN NAC MSNS FROM DOPAMINERGIC AND GLUTAMATERGIC PATHWAYS IN OUD. WE ALSO DESCRIBE NEW FINDINGS RELATED TO TRANSCRIPTIONAL, EPIGENETIC, AND MOLECULAR MECHANISMS IN MSN PLASTICITY IN THE DIFFERENT STAGES OF OUD. 2021 11 325 31 ALLELE-SPECIFIC DNA METHYLATION LEVEL OF FKBP5 IS ASSOCIATED WITH POST-TRAUMATIC STRESS DISORDER. BACKGROUND: FK506-BINDING PROTEIN 5 (FKBP5) BINDS TO GLUCOCORTICOID RECEPTORS AND MODULATES GLUCOCORTICOID SENSITIVITY. THE FKBP5 GENE HAS BEEN IMPLICATED IN THE DYSREGULATION OF HUMAN STRESS RESPONSES, CONTRIBUTING TO THE RISK AND TREATMENT RESPONSE OF STRESS-RELATED DISORDERS. THE PRESENT STUDY EXAMINED WHETHER EPIGENETIC CHANGES IN FKBP5 ARE ASSOCIATED WITH CHRONIC POST-TRAUMATIC STRESS DISORDER (PTSD) STATUS IN THE CONTEXT OF FKBP5 GENETIC VARIATION (RS1360780 POLYMORPHISM) AMONG MALE VETERANS EXPOSED TO COMBAT TRAUMA. METHODS: KOREAN MALE VETERANS WHO SERVED ON ACTIVE DUTY DURING THE VIETNAM WAR WERE CATEGORIZED INTO 2 GROUPS: WITH PTSD (N = 123) AND WITHOUT PTSD (N = 116). THE GENOTYPE OF FKBP5 RS1360780 AND DNA METHYLATION LEVELS OF TWO CPG SITES AT THE FKBP5 INTRON 7 REGION WERE ASSESSED IN PERIPHERAL BLOOD. ANALYSIS OF COVARIANCE WAS PERFORMED TO EXAMINE MAIN AND INTERACTION EFFECTS OF PTSD STATUS AND FKBP5 GENOTYPE ON FKBP5 DNA METHYLATION LEVEL, WITH AGE, TRAUMA LEVELS, AND ALCOHOL USE AS COVARIATES. RESULTS: A SIGNIFICANT MAIN EFFECT OF FKBP5 RS1360780 AND PTSD AND AN INTERACTION EFFECT BETWEEN GENOTYPE AND PTSD STATUS WERE FOUND ON MEAN FKBP5 DNA METHYLATION LEVEL. THE T ALLELE OF RS1360780 WAS ASSOCIATED WITH LOWER FKBP5 METHYLATION LEVEL. IN ADDITION, THE PTSD GROUP SHOWED SIGNIFICANTLY HIGHER METHYLATION THAN DID THE NON-PTSD GROUP AMONG VETERANS CARRYING THE RISK T ALLELE (N = 96), WHILE NO GROUP DIFFERENCE WAS OBSERVED ON METHYLATION LEVELS AMONG VETERANS WITH THE CC GENOTYPE (N = 143). AMONG VETERANS CARRYING THE T ALLELE, FKBP5 METHYLATION LEVELS WERE POSITIVELY CORRELATED WITH THE SEVERITY OF PTSD SYMPTOMS. CONCLUSIONS: THE PRESENT STUDY DEMONSTRATED DIFFERENT FKBP5 METHYLATION LEVELS IN PTSD DEPENDING ON FKBP5 GENETIC VARIATION AMONG VETERANS EXPOSED TO COMBAT TRAUMA. THE PRESENT FINDING SUGGESTS THAT THE GENETIC AND EPIGENETIC MODULATION OF FKBP5 IS INVOLVED IN THE PATHOPHYSIOLOGY OF PTSD. FURTHER LONGITUDINAL RESEARCH INVOLVING PEOPLE EXPOSED TO TRAUMA IS REQUIRED TO UNDERSTAND CAUSAL RELATIONSHIPS OF FKBP5 IN THE DEVELOPMENT AND RECOVERY OF PTSD. 2019 12 3080 39 GENOME-WIDE METHYLATION IN ALCOHOL USE DISORDER SUBJECTS: IMPLICATIONS FOR AN EPIGENETIC REGULATION OF THE CORTICO-LIMBIC GLUCOCORTICOID RECEPTORS (NR3C1). ENVIRONMENTAL FACTORS, INCLUDING SUBSTANCE ABUSE AND STRESS, CAUSE LONG-LASTING CHANGES IN THE REGULATION OF GENE EXPRESSION IN THE BRAIN VIA EPIGENETIC MECHANISMS, SUCH AS DNA METHYLATION. WE EXAMINED GENOME-WIDE DNA METHYLATION PATTERNS IN THE PREFRONTAL CORTEX (PFC, BA10) OF 25 PAIRS OF CONTROL AND INDIVIDUALS WITH ALCOHOL USE DISORDER (AUD), USING THE INFINIUM((R)) METHYLATIONEPIC BEADCHIP. WE IDENTIFIED 5254 DIFFERENTIALLY METHYLATED CPGS (P(NOMINAL) < 0.005). BIOINFORMATIC ANALYSES HIGHLIGHTED BIOLOGICAL PROCESSES CONTAINING GENES RELATED TO STRESS ADAPTATION, INCLUDING THE GLUCOCORTICOID RECEPTOR (ENCODED BY NR3C1). CONSIDERING THAT ALCOHOL IS A STRESSOR, WE FOCUSED OUR ATTENTION ON DIFFERENTIALLY METHYLATED REGIONS OF THE NR3C1 GENE AND VALIDATED THE DIFFERENTIAL METHYLATION OF SEVERAL GENES IN THE NR3C1 NETWORK. CHRONIC ALCOHOL DRINKING RESULTS IN A SIGNIFICANT INCREASED METHYLATION OF THE NR3C1 EXON VARIANT 1(H), WITH A PARTICULAR INCREASE IN THE LEVELS OF 5-HYDROXYMETHYLCYTOSINE OVER 5-METHYLCYTOSINE. THESE CHANGES IN DNA METHYLATION WERE ASSOCIATED WITH REDUCED NR3C1 MRNA AND PROTEIN EXPRESSION LEVELS IN PFC, AS WELL AS OTHER CORTICO-LIMBIC REGIONS OF AUD SUBJECTS WHEN COMPARED WITH CONTROLS. FURTHERMORE, WE SHOW THAT THE EXPRESSION OF SEVERAL STRESS-RESPONSIVE GENES (E.G., CRF, POMC, AND FKBP5) IS ALTERED IN THE PFC OF AUD SUBJECTS. THESE STRESS-RESPONSE GENES WERE ALSO CHANGED IN THE HIPPOCAMPUS, A REGION THAT IS HIGHLY SUSCEPTIBLE TO STRESS. THESE DATA SUGGEST THAT ALCOHOL-DEPENDENT ABERRANT DNA METHYLATION OF NR3C1 AND CONSEQUENT CHANGES IN OTHER STRESS-RELATED GENES MIGHT BE FUNDAMENTAL IN THE PATHOPHYSIOLOGY OF AUD AND LAY THE GROUNDWORK FOR TREATMENTS TARGETING THE EPIGENETIC MECHANISMS REGULATING NR3C1 IN AUD. 2021 13 4828 38 OLANZAPINE INDUCED DNA METHYLATION CHANGES SUPPORT THE DOPAMINE HYPOTHESIS OF PSYCHOSIS. BACKGROUND: THE DOPAMINE (DA) HYPOTHESIS OF SCHIZOPHRENIA PROPOSES THE MENTAL ILLNESS IS CAUSED BY EXCESSIVE TRANSMISSION OF DOPAMINE IN SELECTED BRAIN REGIONS. MULTIPLE LINES OF EVIDENCE, INCLUDING BLOCKAGE OF DOPAMINE RECEPTORS BY ANTIPSYCHOTIC DRUGS THAT ARE USED TO TREAT SCHIZOPHRENIA, SUPPORT THE HYPOTHESIS. HOWEVER, THE DOPAMINE D2 RECEPTOR (DRD2) BLOCKADE CANNOT EXPLAIN SOME IMPORTANT ASPECTS OF THE THERAPEUTIC EFFECT OF ANTIPSYCHOTIC DRUGS. IN THIS STUDY, WE HYPOTHESIZED THAT ANTIPSYCHOTIC DRUGS COULD AFFECT THE TRANSCRIPTION OF GENES IN THE DA PATHWAY BY ALTERING THEIR EPIGENETIC PROFILE. METHODS: TO TEST THIS HYPOTHESIS, WE EXAMINED THE EFFECT OF OLANZAPINE, A COMMONLY USED ATYPICAL ANTIPSYCHOTIC DRUG, ON THE DNA METHYLATION STATUS OF GENES FROM DA NEUROTRANSMISSION IN THE BRAIN AND LIVER OF RATS. GENOMIC DNA ISOLATED FROM HIPPOCAMPUS, CEREBELLUM, AND LIVER OF OLANZAPINE TREATED (N = 2) AND CONTROL (N = 2) RATS WERE ANALYZED USING RAT SPECIFIC METHYLATION ARRAYS. RESULTS: OUR RESULTS SHOW THAT OLANZAPINE CAUSES METHYLATION CHANGES IN GENES ENCODING FOR DA RECEPTORS (DOPAMINE D1 RECEPTOR, DOPAMINE D2 RECEPTOR AND DOPAMINE D5 RECEPTOR), A DA TRANSPORTER (SOLUTE CARRIER FAMILY 18 MEMBER 2), A DA SYNTHESIS (DIFFERENTIAL DISPLAY CLONE 8), AND A DA METABOLISM (CATECHOL-O-METHYLTRANSFERASE). WE ASSESSED A TOTAL OF 40 GENES IN THE DA PATHWAY AND FOUND 19 TO BE DIFFERENTIALLY METHYLATED BETWEEN OLANZAPINE TREATED AND CONTROL RATS. MOST (17/19) GENES SHOWED AN INCREASE IN METHYLATION, IN THEIR PROMOTER REGIONS WITH IN SILICO ANALYSIS STRONGLY INDICATING A FUNCTIONAL POTENTIAL TO SUPPRESS TRANSCRIPTION IN THE BRAIN. CONCLUSION: OUR RESULTS SUGGEST THAT CHRONIC OLANZAPINE MAY REDUCE DA ACTIVITY BY ALTERING GENE METHYLATION. IT MAY ALSO EXPLAIN THE DELAYED THERAPEUTIC EFFECT OF ANTIPSYCHOTICS, WHICH OCCURS DESPITE RAPID DOPAMINE BLOCKADE. FURTHERMORE, GIVEN THE COMMON NATURE OF EPIGENETIC VARIATION, THIS LENDS INSIGHT INTO THE DIFFERENTIAL THERAPEUTIC RESPONSE OF PSYCHOTIC PATIENTS WHO DISPLAY ADEQUATE BLOCKAGE OF DOPAMINE RECEPTORS. 2013 14 2319 43 EPIGENETIC REGULATION OF GABAERGIC NEUROTRANSMISSION AND NEUROSTEROID BIOSYNTHESIS IN ALCOHOL USE DISORDER. BACKGROUND: ALCOHOL USE DISORDER (AUD) IS A CHRONIC RELAPSING BRAIN DISORDER. GABAA RECEPTOR (GABAAR) SUBUNITS ARE A TARGET FOR THE PHARMACOLOGICAL EFFECTS OF ALCOHOL. NEUROSTEROIDS PLAY AN IMPORTANT ROLE IN THE FINE-TUNING OF GABAAR FUNCTION IN THE BRAIN. RECENTLY, WE HAVE SHOWN THAT AUD IS ASSOCIATED WITH CHANGES IN DNA METHYLATION MECHANISMS. HOWEVER, THE ROLE OF DNA METHYLATION IN THE REGULATION OF NEUROSTEROID BIOSYNTHESIS AND GABAERGIC NEUROTRANSMISSION IN AUD PATIENTS REMAINS UNDER-INVESTIGATED. METHODS: IN A COHORT OF POSTMORTEM BRAINS FROM 20 MALE CONTROLS AND AUD PATIENTS, WE INVESTIGATED THE EXPRESSION OF GABAAR SUBUNITS AND NEUROSTEROID BIOSYNTHETIC ENZYMES AND THEIR REGULATION BY DNA METHYLATION MECHANISMS. NEUROSTEROID LEVELS WERE QUANTIFIED BY GAS CHROMATOGRAPHY-MASS SPECTROMETRY. RESULTS: THE ALPHA 2 SUBUNIT EXPRESSION WAS REDUCED DUE TO INCREASED DNA METHYLATION AT THE GENE PROMOTER REGION IN THE CEREBELLUM OF AUD PATIENTS, A BRAIN AREA PARTICULARLY SENSITIVE TO THE EFFECTS OF ALCOHOL. ALCOHOL-INDUCED ALTERATION IN GABAAR SUBUNITS WAS ALSO OBSERVED IN THE PREFRONTAL CORTEX. NEUROSTEROID BIOSYNTHESIS WAS ALSO AFFECTED WITH REDUCED CEREBELLAR EXPRESSION OF THE 18KDA TRANSLOCATOR PROTEIN AND 3ALPHA-HYDROXYSTEROID DEHYDROGENASE MRNAS. NOTABLY, INCREASED DNA METHYLATION LEVELS WERE OBSERVED AT THE PROMOTER REGION OF 3ALPHA-HYDROXYSTEROID DEHYDROGENASE. THESE CHANGES WERE ASSOCIATED WITH MARKEDLY REDUCED LEVELS OF ALLOPREGNANOLONE AND PREGNANOLONE IN THE CEREBELLUM. CONCLUSION: GIVEN THE KEY ROLE OF NEUROSTEROIDS IN MODULATING THE STRENGTH OF GABAAR-MEDIATED INHIBITION, OUR DATA SUGGEST THAT ALCOHOL-INDUCED IMPAIRMENTS IN GABAERGIC NEUROTRANSMISSION MIGHT BE PROFOUNDLY IMPACTED BY REDUCED NEUROSTEROID BIOSYNTHESIS MOST LIKELY VIA DNA HYPERMETHYLATION. 2021 15 886 38 CHRONIC CORTICOSTERONE EXPOSURE INCREASES EXPRESSION AND DECREASES DEOXYRIBONUCLEIC ACID METHYLATION OF FKBP5 IN MICE. THERE IS EVIDENCE FOR HYPERCORTISOLEMIA PLAYING A ROLE IN THE GENERATION OF PSYCHIATRIC SYMPTOMS AND FOR EPIGENETIC VARIATION WITHIN HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS GENES MEDIATING BEHAVIORAL CHANGES. WE TESTED THE HYPOTHESIS THAT EXPRESSION CHANGES WOULD BE INDUCED IN FKBP5 AND OTHER HPA AXIS GENES BY CHRONIC EXPOSURE TO CORTICOSTERONE AND THAT THESE CHANGES WOULD OCCUR THROUGH THE EPIGENETIC MECHANISM OF LOSS OR GAIN OF DNA METHYLATION (DNAM). WE ADMINISTERED CORTICOSTERONE (CORT) TO C57BL/6J MICE VIA THEIR DRINKING WATER FOR 4 WK AND TESTED FOR BEHAVIORAL AND PHYSIOLOGICAL CHANGES AND CHANGES IN GENE EXPRESSION LEVELS USING RNA EXTRACTED FROM HIPPOCAMPUS, HYPOTHALAMUS, AND BLOOD FOR THE FOLLOWING HPA GENES: FKBP5, NR3C1, HSP90, CRH, AND CRHR1. THE CORT MICE EXHIBITED ANXIETY-LIKE BEHAVIOR IN THE ELEVATED PLUS MAZE TEST. CHRONIC EXPOSURE TO CORT ALSO CAUSED A SIGNIFICANT DECREASE IN THE HIPPOCAMPAL AND BLOOD MRNA LEVELS OF NR3C1 AND A DECREASE IN HSP90 IN BLOOD AND CAUSED AN INCREASE IN FKBP5 FOR ALL TISSUES. DIFFERENCES WERE SEEN IN FKBP5 METHYLATION IN HIPPOCAMPUS AND HYPOTHALAMUS. TO ISOLATE A SINGLE-CELL TYPE, WE FOLLOWED UP WITH AN HT-22 MOUSE HIPPOCAMPAL NEURONAL CELL LINE EXPOSED TO CORT. AFTER 7 D, WE OBSERVED A 2.4-FOLD INCREASE IN FKBP5 EXPRESSION AND A DECREASE IN DNAM. IN THE CORT-TREATED MICE, WE ALSO OBSERVED CHANGES IN BLOOD DNAM IN FKBP5. OUR RESULTS SUGGEST DNAM PLAYS A ROLE IN MEDIATING EFFECTS OF GLUCOCORTICOID EXPOSURE ON FKBP5 FUNCTION, WITH POTENTIAL CONSEQUENCES FOR BEHAVIOR. 2010 16 2123 50 EPIGENETIC IMPACTS OF STRESS PRIMING OF THE NEUROINFLAMMATORY RESPONSE TO SARIN SURROGATE IN MICE: A MODEL OF GULF WAR ILLNESS. BACKGROUND: GULF WAR ILLNESS (GWI) IS AN ARCHETYPAL, MEDICALLY UNEXPLAINED, CHRONIC CONDITION CHARACTERISED BY PERSISTENT SICKNESS BEHAVIOUR AND NEUROIMMUNE AND NEUROINFLAMMATORY COMPONENTS. AN ESTIMATED 25-32% OF THE OVER 900,000 VETERANS OF THE 1991 GULF WAR FULFIL THE REQUIREMENTS OF A GWI DIAGNOSIS. IT HAS BEEN HYPOTHESISED THAT THE HIGH PHYSICAL AND PSYCHOLOGICAL STRESS OF COMBAT MAY HAVE INCREASED VULNERABILITY TO IRREVERSIBLE ACETYLCHOLINESTERASE (ACHE) INHIBITORS LEADING TO A PRIMING OF THE NEUROIMMUNE SYSTEM. A NUMBER OF STUDIES HAVE LINKED HIGH LEVELS OF PSYCHOPHYSIOLOGICAL STRESS AND TOXICANT EXPOSURES TO EPIGENETIC MODIFICATIONS THAT REGULATE GENE EXPRESSION. RECENT RESEARCH IN A MOUSE MODEL OF GWI HAS SHOWN THAT PRE-EXPOSURE WITH THE STRESS HORMONE CORTICOSTERONE (CORT) CAUSES AN INCREASE IN EXPRESSION OF SPECIFIC CHEMOKINES AND CYTOKINES IN RESPONSE TO DIISOPROPYL FLUOROPHOSPHATE (DFP), A SARIN SURROGATE AND IRREVERSIBLE ACHE INHIBITOR. METHODS: C57BL/6J MICE WERE EXPOSED TO CORT FOR 4 DAYS, AND EXPOSED TO DFP ON DAY 5, BEFORE SACRIFICE 6 H LATER. THE TRANSCRIPTOME WAS EXAMINED USING RNA-SEQ, AND THE EPIGENOME WAS EXAMINED USING REDUCED REPRESENTATION BISULFITE SEQUENCING AND H3K27AC CHIP-SEQ. RESULTS: WE SHOW TRANSCRIPTIONAL, HISTONE MODIFICATION (H3K27AC) AND DNA METHYLATION CHANGES IN GENES RELATED TO THE IMMUNE AND NEURONAL SYSTEM, POTENTIALLY RELEVANT TO NEUROINFLAMMATORY AND COGNITIVE SYMPTOMS OF GWI. FURTHER EVIDENCE SUGGESTS ALTERED PROPORTIONS OF MYELINATING OLIGODENDROCYTES IN THE FRONTAL CORTEX, PERHAPS CONNECTED TO WHITE MATTER DEFICITS SEEN IN GWI SUFFERERS. CONCLUSIONS: OUR FINDINGS MAY REFLECT THE EARLY CHANGES WHICH OCCURRED IN GWI VETERANS, AND WE OBSERVE ALTERATIONS IN SEVERAL PATHWAYS ALTERED IN GWI SUFFERERS. THESE CLOSE LINKS TO CHANGES SEEN IN VETERANS WITH GWI INDICATES THAT THIS MODEL REFLECTS THE ENVIRONMENTAL EXPOSURES RELATED TO GWI AND MAY PROVIDE A MODEL FOR BIOMARKER DEVELOPMENT AND TESTING FUTURE TREATMENTS. 2018 17 5974 36 TET1 IN NUCLEUS ACCUMBENS OPPOSES DEPRESSION- AND ANXIETY-LIKE BEHAVIORS. DEPRESSION IS A LEADING CAUSE OF DISEASE BURDEN, YET CURRENT THERAPIES FULLY TREAT <50% OF AFFECTED INDIVIDUALS. INCREASING EVIDENCE IMPLICATES EPIGENETIC MECHANISMS IN DEPRESSION AND ANTIDEPRESSANT ACTION. HERE WE EXAMINED A POSSIBLE ROLE FOR THE DNA DIOXYGENASE, TEN-ELEVEN TRANSLOCATION PROTEIN 1 (TET1), IN DEPRESSION-RELATED BEHAVIORAL ABNORMALITIES. WE APPLIED CHRONIC SOCIAL DEFEAT STRESS, AN ETHOLOGICALLY VALIDATED MOUSE MODEL OF DEPRESSION-LIKE BEHAVIORS, AND EXAMINED TET1 EXPRESSION CHANGES IN NUCLEUS ACCUMBENS (NAC), A KEY BRAIN REWARD REGION. WE SHOW DECREASED TET1 EXPRESSION IN NAC IN STRESS-SUSCEPTIBLE MICE ONLY. SURPRISINGLY, SELECTIVE KNOCKOUT OF TET1 IN NAC NEURONS OF ADULT MICE PRODUCED ANTIDEPRESSANT-LIKE EFFECTS IN SEVERAL BEHAVIORAL ASSAYS. TO IDENTIFY TET1 TARGETS THAT MEDIATE THESE ACTIONS, WE PERFORMED RNASEQ ON NAC AFTER CONDITIONAL DELETION OF TET1 AND FOUND THAT IMMUNE-RELATED GENES ARE THE MOST HIGHLY DYSREGULATED. MOREOVER, MANY OF THESE GENES ARE ALSO UPREGULATED IN THE NAC OF RESILIENT MICE AFTER CHRONIC SOCIAL DEFEAT STRESS. THESE FINDINGS REVEAL A NOVEL ROLE FOR TET1, AN ENZYME IMPORTANT FOR DNA HYDROXYMETHYLATION, IN THE BRAIN'S REWARD CIRCUITRY IN MODULATING STRESS RESPONSES IN MICE. WE ALSO IDENTIFY A SUBSET OF GENES THAT ARE REGULATED BY TET1 IN THIS CIRCUITRY. THESE FINDINGS PROVIDE NEW INSIGHT INTO THE PATHOPHYSIOLOGY OF DEPRESSION, WHICH CAN AID IN FUTURE ANTIDEPRESSANT DRUG DISCOVERY EFFORTS. 2017 18 3177 37 H3K9ME2 REGULATION OF BDNF EXPRESSION IN THE HIPPOCAMPUS AND MEDIAL PREFRONTAL CORTEX IS INVOLVED IN THE DEPRESSIVE-LIKE PHENOTYPE INDUCED BY MATERNAL SEPARATION IN MALE RATS. BACKGROUND: EARLY LIFE STRESS (ELS) INDUCES A DEPRESSIVE-LIKE PHENOTYPE AND INCREASES THE RISK OF DEPRESSION. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) HAS BEEN CONFIRMED TO BE INVOLVED IN THE PATHOPHYSIOLOGY OF DEPRESSION. HOWEVER, THE MECHANISM BY WHICH ELS ALTERS THE EPIGENETIC REGULATION OF BDNF AND CHANGES SUSCEPTIBILITY TO DEPRESSION HAS NOT BEEN FULLY CLARIFIED. METHODS: THE PRESENT STUDY USED MATERNAL SEPARATION (MS) AND CHRONIC UNPREDICTED MILD STRESS (CUMS) TO ESTABLISH AN MS ANIMAL MODEL AND A DEPRESSIVE ANIMAL MODEL. WE ASSESSED DEPRESSIVE-LIKE BEHAVIOURS, INCLUDING ANHEDONIA, LOCOMOTOR ACTIVITY, ANXIETY-LIKE BEHAVIOUR, AND SPATIAL MEMORY, USING THE SUCROSE PREFERENCE TEST, THE OPEN FIELD TEST, THE ELEVATED PLUS MAZE TEST, AND THE MORRIS WATER MAZE TEST. WE ALSO INVESTIGATED BDNF AND H3K9ME2 EXPRESSION IN THE HIPPOCAMPUS AND MEDIAL PREFRONTAL CORTEX (MPFC) BY IMMUNOHISTOCHEMISTRY, WESTERN BLOTTING, AND QPCR ANALYSIS. ADDITIONALLY, WE USED UNC0642, A SMALL MOLECULE INHIBITOR OF HISTONE METHYLTRANSFERASE (G9A), AS AN INTERVENTION. RESULTS: THE RESULTS SHOWED THAT CUMS INDUCED DEPRESSIVE-LIKE BEHAVIOURS IN RATS AND RESULTED IN INCREASED H3K9ME2 EXPRESSION AND DECREASED BDNF EXPRESSION IN THE HIPPOCAMPUS AND MPFC. MORE IMPORTANTLY, ADULT MS RATS EXPERIENCING CUMS HAD MORE SEVERE DEPRESSIVE BEHAVIOURS, HAD HIGHER EXPRESSION OF H3K9ME2 IN THE HIPPOCAMPUS AND MPFC, AND HAD LOWER EXPRESSION OF BDNF IN THE HIPPOCAMPUS AND MPFC. IN ADDITION, ADMINISTRATION OF THE G9A INHIBITOR REVERSED MOST OF THE CHANGES. CONCLUSIONS: OUR STUDY SUGGESTS THAT ELS CHANGED BDNF AND H3K9ME2 EXPRESSION IN THE RAT BRAIN, RESULTING IN A DEPRESSIVE-LIKE PHENOTYPE. 2021 19 1761 35 EARLY STRESS EVOKES AGE-DEPENDENT BIPHASIC CHANGES IN HIPPOCAMPAL NEUROGENESIS, BDNF EXPRESSION, AND COGNITION. BACKGROUND: ADULT-ONSET STRESSORS EXERT OPPOSING EFFECTS ON HIPPOCAMPAL NEUROGENESIS AND COGNITION, WITH ENHANCEMENT OBSERVED FOLLOWING MILD STRESS AND DYSFUNCTION FOLLOWING SEVERE CHRONIC STRESS. WHILE EARLY LIFE STRESS EVOKES PERSISTENT CHANGES IN ANXIETY, IT IS UNKNOWN WHETHER EARLY STRESS DIFFERENTIALLY REGULATES HIPPOCAMPAL NEUROGENESIS, TROPHIC FACTOR EXPRESSION, AND COGNITION ACROSS THE LIFE SPAN. METHODS: HIPPOCAMPAL-DEPENDENT COGNITIVE BEHAVIOR, NEUROGENESIS, AND EPIGENETIC REGULATION OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) EXPRESSION WAS EXAMINED AT DISTINCT TIME POINTS ACROSS THE LIFE SPAN IN RATS SUBJECTED TO THE EARLY STRESS OF MATERNAL SEPARATION (ES) AND CONTROL GROUPS. WE ALSO EXAMINED THE INFLUENCE OF CHRONIC ANTIDEPRESSANT TREATMENT ON THE NEUROGENIC, NEUROTROPHIC, AND COGNITIVE CHANGES IN MIDDLE-AGED ES ANIMALS. RESULTS: ANIMALS SUBJECTED TO EARLY STRESS OF MATERNAL SEPARATION EXAMINED DURING POSTNATAL LIFE AND YOUNG ADULTHOOD EXHIBITED ENHANCED HIPPOCAMPAL NEUROGENESIS, DECREASED REPRESSIVE HISTONE METHYLATION AT THE BDNF IV PROMOTER ALONG WITH ENHANCED BDNF LEVELS, AND IMPROVED PERFORMANCE ON THE STRESS-ASSOCIATED MORRIS WATER MAZE. STRIKINGLY, OPPOSING CHANGES IN HIPPOCAMPAL NEUROGENESIS AND EPIGENETIC REGULATION OF BDNF IV EXPRESSION, CONCOMITANT WITH IMPAIRMENTS ON HIPPOCAMPAL-DEPENDENT COGNITIVE TASKS, WERE OBSERVED IN MIDDLE-AGED ES ANIMALS. CHRONIC ANTIDEPRESSANT TREATMENT WITH AMITRIPTYLINE ATTENUATED THE MALADAPTIVE NEUROGENIC, EPIGENETIC, TRANSCRIPTIONAL, AND COGNITIVE EFFECTS IN MIDDLE-AGED ES ANIMALS. CONCLUSIONS: OUR STUDY PROVIDES NOVEL INSIGHTS INTO THE SHORT- AND LONG-TERM CONSEQUENCES OF ES, DEMONSTRATING BOTH BIPHASIC AND UNIQUE, AGE-DEPENDENT CHANGES AT THE MOLECULAR, EPIGENETIC, NEUROGENIC, AND BEHAVIORAL LEVELS. THESE RESULTS INDICATE THAT EARLY STRESS MAY TRANSIENTLY ENDOW ANIMALS WITH A POTENTIAL ADAPTIVE ADVANTAGE IN STRESSFUL ENVIRONMENTS BUT ACROSS A LIFE SPAN IS ASSOCIATED WITH LONG-TERM DELETERIOUS EFFECTS. 2013 20 4989 31 PCSK9 IS INCREASED IN CEREBROSPINAL FLUID OF INDIVIDUALS WITH ALCOHOL USE DISORDER. BACKGROUND: RECENT STUDIES HAVE SHOWN THAT ALCOHOL USE AFFECTS THE REGULATION AND EXPRESSION OF PROPROTEIN CONVERTASE SUBTILISIN/KEXIN 9 (PCSK9). WHILE A MAJOR ROLE OF PCSK9 IN HEPATIC FUNCTION AND LIPID REGULATION HAS BEEN CLEARLY ESTABLISHED, OTHER PLEIOTROPIC EFFECTS REMAIN POORLY UNDERSTOOD. EXISTING RESEARCH SUGGESTS A POSITIVE ASSOCIATION BETWEEN PCSK9 EXPRESSION IN THE BRAIN AND PSYCHOPATHOLOGY, WITH INCREASED LEVELS OF PCSK9 IN THE CEREBROSPINAL FLUID (CSF) OF INDIVIDUALS WITH DEMENTIA AND EPIGENETIC MODIFICATIONS OF PCSK9 ASSOCIATED WITH ALCOHOL USE DISORDER (AUD). IN THIS STUDY, WE HYPOTHESIZED THAT CHRONIC ALCOHOL USE WOULD INCREASE PCSK9 EXPRESSION IN CSF. METHODS: PCSK9 LEVELS IN CSF WERE MEASURED IN INDIVIDUALS WITH AUD (N = 42) ADMITTED TO AN INPATIENT REHABILITATION PROGRAM AND CONTROLS (N = 25). CSF SAMPLES IN AUD WERE ASSESSED AT 2 TIME POINTS, AT DAY 5 AND DAY 21 AFTER ADMISSION. FURTHERMORE, PLASMA SAMPLES WERE COLLECTED AND MEASURED FROM THE INDIVIDUALS WITH AUD. RESULTS: PCSK9 IN CSF WAS SIGNIFICANTLY INCREASED IN THE AUD GROUP AT DAY 5 AND DAY 21 COMPARED TO THE CONTROLS (P < 0.0001). PLASMA PCSK9 LEVELS WERE CORRELATED POSITIVELY WITH CSF PCSK9 LEVELS IN AUD (P = 0.0493). CONCLUSIONS: OUR DATA SUGGEST THAT PCSK9 IS ELEVATED IN THE CSF OF INDIVIDUALS WITH AUD, WHICH MAY INDICATE A POTENTIAL ROLE OF PCSK9 IN AUD. ADDITIONAL STUDIES ARE NECESSARY TO FURTHER ELUCIDATE THE FUNCTIONS OF PCSK9 IN THE BRAIN. 2019