1 2347 135 EPIGENETIC REGULATION OF MIR-124 UNDER ETHANOL DEPENDENCE AND WITHDRAWAL. WITHDRAWAL FROM CHRONIC ALCOHOL CAUSE THE PERSISTENT MOLECULAR ALTERATION, SUCH AS CHANGES IN THE RELEASE OF NEUROTRANSMITTER AND GENE EXPRESSION. THE ALTERATIONS ARE THOUGHT TO INCREASE IN THE RISK OF RELAPSE. RECENT STUDIES SUGGEST THAT THE GENE EXPRESSION REGULATED BY HISTONE ACETYLATION MAY PLAY AN IMPORTANT ROLE IN THE DEPENDENCE OF ABUSED DRUGS, INCLUDING OF ETHANOL. FURTHERMORE, MIRNA, ANOTHER REGULATOR OF GENE EXPRESSION, ARE ALSO IMPORTANT MOLECULES FOR THE DEPENDENCE. HOWEVER, CHANGES IN THE MOLECULES UNDER ETHANOL WITHDRAWAL AND ITS RELATIONSHIP ARE POORLY UNDERSTOOD. IN THE PRESENT STUDY, WE INVESTIGATED THE EXPRESSION OF ACETYLATED HISTONE H3 AND MIR-124 IN MOUSE BRAIN AT 3 DAYS AFTER ETHANOL WITHDRAWAL. 6-WEEK AGES OF C57BL/6J MICE WERE TREATED WITH LIQUID DIET CONTAINING ETHANOL FOR 10 DAYS. USING THE ESCALATING ETHANOL DOSAGE SCHEDULE, THE MICE WERE FED THE ETHANOL DIET AS FOLLOWS: 1ST DAY: 1 W/V%: 2ND AND 3RD DAY: 3 W/V%; 4TH AND 5TH DAY: 4 W/V% AND FROM THE 6TH TO 10TH DAY: 5 W/V% ETHANOL DIET, RESPECTIVELY. THE PAIR-FED CONTROL MICE WERE GIVEN THE SAME VOLUME OF ETHANOL-FREE LIQUID DIET WITH GLUCOSE SUBSTITUTED IN ISOCALORIC QUANTITIES FOR ETHANOL. AFTER FEEDING ALCOHOL LIQUID DIET, THE MICE SHOWED SEVERE WITHDRAWAL SIGNS. THE EXPRESSION OF ACETYLATED HISTONE H3 WAS SIGNIFICANTLY DECREASED IN LIMBIC FOREBRAIN AT 3 DAYS AFTER WITHDRAWAL. WE FOUND THAT MIR-124 ALSO DECREASED IN THE LIMBIC FOREBRAIN. IT HAS BEEN REPORTED THAT CDC42 REGULATES NEURONAL DEVELOPMENT AS A TARGET OF MIR-124. WE FOUND THAT CDC42 PROTEIN MARKEDLY INCREASED IN BOTH BRAIN REGIONS AT 3 DAYS AFTER WITHDRAWAL. OUR FINDINGS SUGGEST THAT CHANGES IN THE EXPRESSION OF MIR-124 VIA HISTONE ACETYLATION LEADS TO CHANGE THE CDC42 EXPRESSION UNDER ETHANOL WITHDRAWAL. 2012 2 2156 44 EPIGENETIC MECHANISMS ARE INVOLVED IN THE REGULATION OF ETHANOL CONSUMPTION IN MICE. BACKGROUND: REPEATED ALCOHOL EXPOSURE IS KNOWN TO INCREASE SUBSEQUENT ETHANOL CONSUMPTION IN MICE. HOWEVER, THE UNDERLYING MECHANISMS HAVE NOT BEEN FULLY ELUCIDATED. ONE POSTULATED MECHANISM INVOLVES EPIGENETIC MODIFICATIONS, INCLUDING HISTONE MODIFICATIONS AND DNA METHYLATION OF RELEVANT GENES SUCH AS NR2B OR BDNF. METHODS: TO INVESTIGATE THE ROLE OF EPIGENETIC MECHANISMS IN THE DEVELOPMENT OF ALCOHOL DRINKING BEHAVIOR, AN ESTABLISHED CHRONIC INTERMITTENT ETHANOL EXPOSURE REINFORCED ETHANOL DRINKING MOUSE MODEL WITH VAPOR INHALATION OVER TWO 9-DAY TREATMENT REGIMENS WAS USED. THE DNA METHYLTRANSFERASE INHIBITOR, 5-AZACYTIDINE OR THE HISTONE DEACETYLASE INHIBITOR, TRICHOSTATIN A WAS ADMINISTERED (INTRAPERITONEALLY) TO C57BL/6 MICE 30 MIN BEFORE DAILY EXPOSURE TO CHRONIC INTERMITTENT ETHANOL. CHANGES IN ETHANOL CONSUMPTION WERE MEASURED USING THE 2-BOTTLE CHOICE TEST. RESULTS: THE RESULTS INDICATED THAT SYSTEMIC ADMINISTRATION OF TRICHOSTATIN A (2.5 MICROG/G) FACILITATED CHRONIC INTERMITTENT ETHANOL-INDUCED ETHANOL DRINKING, BUT SYSTEMIC ADMINISTRATION OF 5-AZACYTIDINE (2 MICROG/G) DID NOT CAUSE THE SAME EFFECT. HOWEVER, WHEN 5-AZACYTIDINE WAS ADMINISTERED BY INTRACEREBROVENTRICULAR INJECTION, IT FACILITATED CHRONIC INTERMITTENT ETHANOL-INDUCED ETHANOL DRINKING. FURTHERMORE, THE INCREASED DRINKING CAUSED BY CHRONIC INTERMITTENT ETHANOL WAS PREVENTED BY INJECTION OF A METHYL DONOR, S-ADENOSYL-L-METHIONINE. TO PROVIDE EVIDENCE THAT CHRONIC INTERMITTENT ETHANOL- OR TRICHOSTATIN A-INDUCED DNA DEMETHYLATION AND HISTONE MODIFICATIONS OF THE NR2B PROMOTER MAY UNDERLIE THE ALTERED ETHANOL CONSUMPTION, WE EXAMINED EPIGENETIC MODIFICATIONS AND NR2B EXPRESSION IN THE PREFRONTAL CORTEX OF THESE MICE. CHRONIC INTERMITTENT ETHANOL OR TRICHOSTATIN A DECREASED DNA METHYLATION AND INCREASED HISTONE ACETYLATION IN THE NR2B GENE PROMOTER, AS WELL AS MRNA LEVELS OF NR2B IN THESE MICE. CONCLUSIONS: TAKEN TOGETHER, THESE RESULTS INDICATE THAT EPIGENETIC MODIFICATIONS ARE INVOLVED IN REGULATING ETHANOL DRINKING BEHAVIOR, PARTIALLY THROUGH ALTERING NR2B EXPRESSION. 2014 3 6175 42 THE HISTONE DEACETYLASE INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) ALLEVIATES DEPRESSION-LIKE BEHAVIOR AND NORMALIZES EPIGENETIC CHANGES IN THE HIPPOCAMPUS DURING ETHANOL WITHDRAWAL. WITHDRAWAL FROM CHRONIC ALCOHOL DRINKING CAN CAUSE DEPRESSION, LEADING TO AN INABILITY TO FUNCTION IN DAILY LIFE AND AN INCREASED RISK FOR RELAPSE TO HARMFUL DRINKING. UNDERSTANDING THE CAUSES OF ALCOHOL WITHDRAWAL-RELATED DEPRESSION MAY LEAD TO NEW THERAPEUTIC TARGETS FOR TREATMENT. EPIGENETIC FACTORS HAVE RECENTLY EMERGED AS IMPORTANT CONTRIBUTORS TO BOTH DEPRESSION AND ALCOHOL USE DISORDER (AUD). SPECIFICALLY, ACETYLATION OF THE N-TERMINAL TAILS OF HISTONE PROTEINS THAT PACKAGE DNA INTO NUCLEOSOMES IS ALTERED IN STRESS-INDUCED MODELS OF DEPRESSION AND DURING ALCOHOL WITHDRAWAL. THE GOAL OF THIS STUDY WAS TO EXAMINE DEPRESSION-LIKE BEHAVIOR DURING ALCOHOL WITHDRAWAL AND ASSOCIATED CHANGES IN HISTONE ACETYLATION AND EXPRESSION OF HISTONE DEACETYLASE 2 (HDAC2) IN THE HIPPOCAMPUS, A BRAIN REGION CRITICAL FOR MOOD REGULATION AND DEPRESSION. MALE SPRAGUE-DAWLEY RATS WERE TREATED WITH THE LIEBER-DECARLI ETHANOL LIQUID DIET FOR 15 DAYS AND THEN UNDERWENT WITHDRAWAL. RATS WERE TREATED WITH THE HDAC INHIBITOR, SUBEROYLANILIDE HYDROXAMIC ACID (SAHA), DURING WITHDRAWAL AND WERE TESTED FOR DEPRESSION-LIKE BEHAVIOR. IN A SEPARATE GROUP OF RATS, THE HIPPOCAMPUS WAS ANALYZED FOR MRNA AND PROTEIN EXPRESSION OF HDAC2 AND LEVELS OF HISTONE H3 LYSINE 9 ACETYLATION (H3K9AC) DURING CHRONIC ETHANOL EXPOSURE AND WITHDRAWAL. RATS UNDERGOING ETHANOL WITHDRAWAL EXHIBITED DEPRESSION-LIKE BEHAVIOR AND HAD INCREASED HDAC2 AND DECREASED H3K9AC LEVELS IN SPECIFIC STRUCTURES OF THE HIPPOCAMPUS. TREATMENT WITH SAHA DURING WITHDRAWAL AMELIORATED DEPRESSION-LIKE BEHAVIOR AND NORMALIZED CHANGES IN HIPPOCAMPAL HDAC2 AND H3K9AC LEVELS. THESE RESULTS DEMONSTRATE THAT ETHANOL WITHDRAWAL CAUSES AN ALTERED EPIGENETIC STATE IN THE HIPPOCAMPUS. TREATMENT WITH AN HDAC INHIBITOR CAN CORRECT THIS STATE AND ALLEVIATE DEPRESSION-LIKE SYMPTOMS DEVELOPED DURING WITHDRAWAL. TARGETING HISTONE ACETYLATION MAY BE A NOVEL STRATEGY TO REDUCE ETHANOL WITHDRAWAL-INDUCED DEPRESSION. 2019 4 5177 46 PREFRONTAL CORTEX EXPRESSION OF CHROMATIN MODIFIER GENES IN MALE WSP AND WSR MICE CHANGES ACROSS ETHANOL DEPENDENCE, WITHDRAWAL, AND ABSTINENCE. ALCOHOL-USE DISORDER (AUD) IS A RELAPSING DISORDER ASSOCIATED WITH EXCESSIVE ETHANOL CONSUMPTION. RECENT STUDIES SUPPORT THE INVOLVEMENT OF EPIGENETIC MECHANISMS IN THE DEVELOPMENT OF AUD. STUDIES CARRIED OUT SO FAR HAVE FOCUSED ON A FEW SPECIFIC EPIGENETIC MODIFICATIONS. THE GOAL OF THIS PROJECT WAS TO INVESTIGATE GENE EXPRESSION CHANGES OF EPIGENETIC REGULATORS THAT MEDIATE A BROAD ARRAY OF CHROMATIN MODIFICATIONS AFTER CHRONIC ALCOHOL EXPOSURE, CHRONIC ALCOHOL EXPOSURE FOLLOWED BY 8 H WITHDRAWAL, AND CHRONIC ALCOHOL EXPOSURE FOLLOWED BY 21 DAYS OF ABSTINENCE IN WITHDRAWAL-RESISTANT (WSR) AND WITHDRAWAL SEIZURE-PRONE (WSP) SELECTED MOUSE LINES. WE FOUND THAT CHRONIC VAPOR EXPOSURE TO HIGHLY INTOXICATING LEVELS OF ETHANOL ALTERS THE EXPRESSION OF SEVERAL CHROMATIN REMODELING GENES MEASURED BY QUANTITATIVE PCR ARRAY ANALYSES. THE IDENTIFIED EFFECTS WERE INDEPENDENT OF SELECTED LINES, WHICH, HOWEVER, DISPLAYED BASELINE DIFFERENCES IN EPIGENETIC GENE EXPRESSION. WE REPORTED DYSREGULATION IN THE EXPRESSION OF GENES INVOLVED IN HISTONE ACETYLATION, DEACETYLATION, LYSINE AND ARGININE METHYLATION AND UBIQUITINATIONHYLATION DURING CHRONIC ETHANOL EXPOSURE AND WITHDRAWAL, BUT NOT AFTER 21 DAYS OF ABSTINENCE. ETHANOL-INDUCED CHANGES ARE CONSISTENT WITH DECREASED HISTONE ACETYLATION AND WITH DECREASED DEPOSITION OF THE PERMISSIVE UBIQUITINATION MARK H2BK120UB, ASSOCIATED WITH REDUCED TRANSCRIPTION. ON THE OTHER HAND, ETHANOL-INDUCED CHANGES IN THE EXPRESSION OF GENES INVOLVED IN HISTONE LYSINE METHYLATION ARE CONSISTENT WITH INCREASED TRANSCRIPTION. THE NET RESULT OF THESE MODIFICATIONS ON GENE EXPRESSION IS LIKELY TO DEPEND ON THE COMBINATION OF THE SPECIFIC HISTONE TAIL MODIFICATIONS PRESENT AT A GIVEN TIME ON A GIVEN PROMOTER. SINCE ALCOHOL DOES NOT MODULATE GENE EXPRESSION UNIDIRECTIONALLY, IT IS NOT SURPRISING THAT ALCOHOL DOES NOT UNIDIRECTIONALLY ALTER CHROMATIN STRUCTURE TOWARD A CLOSED OR OPEN STATE, AS SUGGESTED BY THE RESULTS OF THIS STUDY. 2017 5 894 34 CHRONIC ETHANOL FEEDING ALTERS HEPATOCYTE MEMORY WHICH IS NOT ALTERED BY ACUTE FEEDING. BACKGROUND: GENE EXPRESSION CHANGES IN THE LIVER AFTER ACUTE BINGE DRINKING MAY DIFFER FROM THE CHANGES SEEN IN CHRONIC ETHANOL FEEDING IN THE RAT. THE CHANGES IN GENE EXPRESSION AFTER CHRONIC ETHANOL FEEDING MAY SENSITIZE THE LIVER TO ALCOHOL-INDUCED LIVER DAMAGE, WHICH IS NOT SEEN AFTER ACUTE BINGE DRINKING. METHODS: TO TEST THIS HYPOTHESIS, GENE MICROARRAY ANALYSIS WAS PERFORMED ON THE LIVERS OF RATS (N = 3) FED AN ACUTE BINGE DOSE OF ETHANOL (6 G/KG BODY WT) AND KILLED AT 3 AND 12 HOURS AFTER ETHANOL BY GAVAGE. THE GENE MICROARRAYS WERE COMPARED WITH THOSE MADE ON THE LIVER OF RATS FROM A PREVIOUS STUDY, IN WHICH THE RATS WERE FED ETHANOL BY INTRAGASTRIC TUBE FOR 1 MONTH (36% OF CALORIES DERIVED FROM ETHANOL). RESULTS: MICROARRAY ANALYSIS DATA VARIED BETWEEN THE ACUTE AND CHRONIC MODELS IN SEVERAL IMPORTANT RESPECTS. GROWTH FACTORS INCREASED MAINLY IN THE CHRONIC ALCOHOL FED RAT. CHANGES IN ENZYMES INVOLVED IN OXIDATIVE STRESS WERE NOTED ONLY WITH CHRONIC ETHANOL FEEDING. GENE EXPRESSION OF FAT METABOLISM WAS INCREASED ONLY WITH CHRONIC ETHANOL FEEDING. MOST IMPORTANTLY, EPIGENETIC RELATED ENZYMES AND ACETYLATION AND METHYLATION OF HISTONES CHANGED ONLY AFTER CHRONIC ETHANOL FEEDING. CONCLUSIONS: THE RESULTS SUPPORT THE CONCEPT THAT CHRONIC ETHANOL INGESTION INDUCES ALTERED GENE EXPRESSION AS A RESULT OF CHANGES IN EPIGENETIC MECHANISMS, WHERE ACETYLATION AND METHYLATION OF HISTONES WERE ALTERED. 2009 6 6801 62 [EPIGENETIC MECHANISMS AND ALCOHOL USE DISORDERS: A POTENTIAL THERAPEUTIC TARGET]. ALCOHOL USE DISORDER IS A DEVASTATING ILLNESS WITH A PROFOUND HEALTH IMPACT, AND ITS DEVELOPMENT IS DEPENDENT ON BOTH GENETIC AND ENVIRONMENTAL FACTORS. THIS DISEASE OCCURS OVER TIME AND REQUIRES CHANGES IN BRAIN GENE EXPRESSION. THERE IS CONVERGING EVIDENCE SUGGESTING THAT THE EPIGENETIC PROCESSES MAY PLAY A ROLE IN THE ALCOHOL-INDUCED GENE REGULATIONS AND BEHAVIOR SUCH AS THE INTERVENTION OF DNA METHYLATION AND HISTONE ACETYLATION. HISTONE ACETYLATION, LIKE HISTONE METHYLATION, IS A HIGHLY DYNAMIC PROCESS REGULATED BY TWO CLASSES OF ENZYMES: HISTONE ACETYLTRANSFERASES AND HISTONE DEACETYLASES (HDACS). TO DATE, 18 HUMAN HDAC ISOFORMS HAVE BEEN CHARACTERIZED, AND BASED ON THEIR SEQUENCE HOMOLOGIES AND COFACTOR DEPENDENCIES, THEY HAVE BEEN PHYLOGENETICALLY CATEGORIZED INTO 4 MAIN CLASSES: CLASSES I, II (A AND B), III, AND IV. IN THE BRAIN, EXPRESSION OF THE DIFFERENT CLASSES OF HDACS VARIES BETWEEN CELL TYPES AND ALSO IN THEIR SUBCELLULAR LOCALIZATION (NUCLEUS AND/OR CYTOSOL). FURTHERMORE, WE RECENTLY SHOWED THAT A SINGLE ETHANOL EXPOSURE INHIBITS HDAC ACTIVITY AND INCREASES BOTH H3 AND H4 HISTONE ACETYLATION WITHIN THE AMYGDALA OF RATS. IN THE BRAIN OF ALCOHOLIC PATIENTS, ETHANOL HAS BEEN SHOWN TO INDUCE HISTONE-RELATED AND DNA METHYLATION EPIGENETIC CHANGES IN SEVERAL REWARD REGIONS INVOLVED IN REWARD PROCESSES SUCH AS HIPPOCAMPUS, PREFRONTAL CORTEX, AND AMYGDALA. WE RECENTLY DEMONSTRATED ALTERATION OF HISTONE H3 ACETYLATION LEVELS IN SEVERAL BRAIN REGIONS FROM THE REWARD CIRCUIT OF RATS MADE DEPENDENT TO ALCOHOL AFTER CHRONIC AND INTERMITTENT EXPOSURE TO ETHANOL VAPOR. IN NEURONAL CELL LINE CULTURE, ETHANOL WAS SHOWN TO INDUCE HDAC EXPRESSION. IN MOUSE AND RAT BRAIN, NUMEROUS STUDIES REPORTED EPIGENETIC ALTERATIONS FOLLOWING ETHANOL EXPOSURE. WE ALSO DEMONSTRATED THAT BOTH THE EXPRESSION OF GENES AND THE ACTIVITY OF ENZYMES INVOLVED IN EPIGENETIC MECHANISMS ARE CHANGED AFTER REPEATED ADMINISTRATIONS OF ETHANOL IN MICE SENSITIZED TO THE MOTOR STIMULANT EFFECT OF ETHANOL (A MODEL OF DRUG-INDUCED NEUROPLASTICITY). NUMEROUS STUDIES HAVE SHOWN THAT HDAC INHIBITORS ARE ABLE TO COUNTER ETHANOL-INDUCED BEHAVIORS AND THE ETHANOL-INDUCED CHANGES IN THE LEVELS OF HDAC AND/OR LEVELS OF ACETYLATED HDAC. FOR EXAMPLE, TRICHOSTATIN A (TSA) TREATMENT CAUSED THE REVERSAL OF ETHANOL-INDUCED TOLERANCE, ANXIETY, AND ETHANOL DRINKING BY INHIBITING HDAC ACTIVITY, THEREBY INCREASING HISTONE ACETYLATION IN THE AMYGDALA OF RATS. ANOTHER STUDY DEMONSTRATED THAT TSA PREVENTED THE DEVELOPMENT OF ETHANOL WITHDRAWAL INDUCED ANXIETY IN RATS BY RESCUING DEFICITS IN HISTONE ACETYLATION INDUCED BY INCREASED HDAC ACTIVITY IN THE AMYGDALA. WE HAVE DEMONSTRATED THAT TREATMENT WITH THE HDAC INHIBITOR SODIUM BUTYRATE BLOCKS BOTH THE DEVELOPMENT AND THE EXPRESSION OF ETHANOL-INDUCED BEHAVIORAL SENSITIZATION IN MICE. IN THIS CONTEXT, CONVERGING EVIDENCE INDICATES THAT HDAC INHIBITORS COULD BE USEFUL IN COUNTERACTING ETHANOL-INDUCED GENE REGULATIONS VIA EPIGENETIC MECHANISMS, THAT IS, HDAC INHIBITORS COULD AFFECT DIFFERENT ACETYLATION SITES AND MAY ALSO ALTER THE EXPRESSION OF DIFFERENT GENES THAT COULD IN TURN COUNTERACT THE EFFECT OF ETHANOL. RECENT WORK IN RODENTS HAS SHOWN THAT SYSTEMIC ADMINISTRATION OF PAN HDAC CLASS I AND II INHIBITORS, TSA AND N-HYDROXY-N-PHENYL-OCTANEDIAMIDE [SUBEROYLANILIDE HYDROXAMIC ACID] (SAHA), AND OF THE MORE SELECTIVE INHIBITOR (MAINLY HDAC1 AND HDAC9) MS-275, DECREASE BINGE-LIKE ALCOHOL DRINKING IN MICE. SAHA SELECTIVELY REDUCED ETHANOL OPERANT SELF-ADMINISTRATION AND SEEKING IN RATS. OUR PREVIOUS STUDY REVEALED THAT MS-275 STRONGLY DECREASED OPERANT ETHANOL SELF-ADMINISTRATION IN ALCOHOL-DEPENDENT RATS WHEN ADMINISTERED 30 MINUTES BEFORE THE SESSION AT THE SECOND DAY OF INJECTION. WE ALSO DEMONSTRATED THAT INTRA-CEREBRO-VENTRICULAR INFUSION OF MS-275 INCREASES ACETYLATION OF HISTONE 4 WITHIN THE NUCLEUS ACCUMBENS AND THE DORSOLATERAL STRIATUM, ASSOCIATED TO A DECREASE IN ETHANOL SELF-ADMINISTRATION BY ABOUT 75%. MS-275 ALSO DIMINISHED BOTH THE MOTIVATION TO CONSUME ETHANOL (25% DECREASE), RELAPSE (BY ABOUT 50%) AND POSTPONED REACQUISITION AFTER ABSTINENCE. BOTH LITERATURE AND SEVERAL OF OUR STUDIES STRONGLY SUPPORT THE POTENTIAL THERAPEUTIC INTEREST OF TARGETING EPIGENETIC MECHANISMS IN EXCESSIVE ALCOHOL DRINKING AND STRENGTHEN THEINTEREST OF FOCUSING ON SPECIFIC ISOFORMS OF HISTONE DEACETYLASES. 2017 7 4173 38 MELATONIN INDUCES HISTONE HYPERACETYLATION IN THE RAT BRAIN. WE HAVE REPORTED THAT MELATONIN INDUCES HISTONE HYPERACETYLATION IN MOUSE NEURAL STEM CELLS, SUGGESTING AN EPIGENETIC ROLE FOR THIS PLEIOTROPIC HORMONE. TO SUPPORT SUCH A ROLE, IT IS NECESSARY TO DEMONSTRATE THAT MELATONIN PRODUCES SIMILAR EFFECTS IN VIVO. HISTONE ACETYLATION, FOLLOWING CHRONIC TREATMENT WITH MELATONIN (4MUG/ML IN DRINKING WATER FOR 17 DAYS), WAS EXAMINED BY WESTERN BLOTTING IN SELECTED RAT BRAIN REGIONS. MELATONIN INDUCED SIGNIFICANT INCREASES IN HISTONE H3 AND HISTONE H4 ACETYLATION IN THE HIPPOCAMPUS. HISTONE H4 WAS ALSO HYPERACETYLATED IN THE STRIATUM, BUT THERE WERE NO SIGNIFICANT CHANGES IN HISTONE H3 ACETYLATION IN THIS BRAIN REGION. NO SIGNIFICANT CHANGES IN THE ACETYLATION OF EITHER HISTONE H3 OR H4 WERE OBSERVED IN THE MIDBRAIN AND CEREBELLUM. AN EXAMINATION OF KINASE ACTIVATION, WHICH MAY BE RELATED TO THESE CHANGES, REVEALED THAT MELATONIN TREATMENT INCREASED THE LEVELS OF PHOSPHO-ERK (EXTRACELLULAR SIGNAL-REGULATED KINASE) IN THE HIPPOCAMPUS AND STRIATUM, BUT PHOSPHO-AKT (PROTEIN KINASE B) LEVELS WERE UNCHANGED. THESE FINDINGS SUGGEST THAT CHROMATIN REMODELING AND ASSOCIATED CHANGES IN THE EPIGENETIC REGULATION OF GENE EXPRESSION UNDERLIE THE MULTIPLE PHYSIOLOGICAL EFFECTS OF MELATONIN. 2013 8 4150 46 MECHANISTIC INSIGHTS INTO EPIGENETIC MODULATION OF ETHANOL CONSUMPTION. THERE IS GROWING EVIDENCE THAT SMALL-MOLECULE INHIBITORS OF EPIGENETIC MODULATORS, SUCH AS HISTONE DEACETYLASES (HDAC) AND DNA METHYLTRANSFERASES (DNMT), CAN REDUCE VOLUNTARY ETHANOL CONSUMPTION IN ANIMAL MODELS, BUT MOLECULAR AND CELLULAR PROCESSES UNDERLYING THIS BEHAVIORAL EFFECT ARE POORLY UNDERSTOOD. WE USED C57BL/6J MALE MICE TO INVESTIGATE THE EFFECTS OF TWO FDA-APPROVED DRUGS, DECITABINE (A DNMT INHIBITOR) AND SAHA (AN HDAC INHIBITOR), ON ETHANOL CONSUMPTION USING TWO TESTS: BINGE-LIKE DRINKING IN THE DARK (DID) AND CHRONIC INTERMITTENT EVERY OTHER DAY (EOD) DRINKING. DECITABINE BUT NOT SAHA REDUCED ETHANOL CONSUMPTION IN BOTH TESTS. WE FURTHER INVESTIGATED DECITABINE'S EFFECTS ON THE BRAIN'S REWARD PATHWAY BY GENE EXPRESSION PROFILING IN THE VENTRAL TEGMENTAL AREA (VTA), USING RNA SEQUENCING AND ELECTROPHYSIOLOGICAL RECORDINGS FROM VTA DOPAMINERGIC NEURONS. DECITABINE-INDUCED DECREASES IN EOD DRINKING WERE ASSOCIATED WITH GLOBAL CHANGES IN GENE EXPRESSION, IMPLICATING REGULATION OF CEREBRAL BLOOD FLOW, EXTRACELLULAR MATRIX ORGANIZATION, AND NEUROIMMUNE FUNCTIONS IN DECITABINE ACTIONS. IN ADDITION, AN IN VIVO ADMINISTRATION OF DECITABINE SHORTENED ETHANOL-INDUCED EXCITATION OF VTA DOPAMINERGIC NEURONS IN VITRO, SUGGESTING THAT DECITABINE REDUCES ETHANOL DRINKING VIA CHANGES IN THE REWARD PATHWAY. TAKEN TOGETHER, OUR DATA SUGGEST A CONTRIBUTION OF BOTH NEURONAL AND NON-NEURONAL MECHANISMS IN THE VTA IN THE REGULATION OF ETHANOL CONSUMPTION. DECITABINE AND OTHER EPIGENETIC COMPOUNDS HAVE BEEN APPROVED FOR CANCER TREATMENT, AND UNDERSTANDING THEIR MECHANISMS OF ACTIONS IN THE BRAIN MAY ASSIST IN REPURPOSING THESE DRUGS AND DEVELOPING NOVEL THERAPIES FOR CENTRAL DISORDERS, INCLUDING DRUG ADDICTION. 2017 9 1086 44 COCAINE ADMINISTRATION AND ITS WITHDRAWAL ENHANCE THE EXPRESSION OF GENES ENCODING HISTONE-MODIFYING ENZYMES AND HISTONE ACETYLATION IN THE RAT PREFRONTAL CORTEX. CHRONIC EXPOSURE TO COCAINE, CRAVING, AND RELAPSE ARE ATTRIBUTED TO LONG-LASTING CHANGES IN GENE EXPRESSION ARISING THROUGH EPIGENETIC AND TRANSCRIPTIONAL MECHANISMS. ALTHOUGH SEVERAL BRAIN REGIONS ARE INVOLVED IN THESE PROCESSES, THE PREFRONTAL CORTEX SEEMS TO PLAY A CRUCIAL ROLE NOT ONLY IN MOTIVATION AND DECISION-MAKING BUT ALSO IN EXTINCTION AND SEEKING BEHAVIOR. IN THIS STUDY, WE APPLIED COCAINE SELF-ADMINISTRATION AND EXTINCTION TRAINING PROCEDURES IN RATS WITH A YOKED TRIAD TO DETERMINE DIFFERENTIALLY EXPRESSED GENES IN PREFRONTAL CORTEX. MICROARRAY ANALYSIS SHOWED SIGNIFICANT UPREGULATION OF SEVERAL GENES ENCODING HISTONE MODIFICATION ENZYMES DURING EARLY EXTINCTION TRAINING. SUBSEQUENT REAL-TIME PCR TESTING OF THESE GENES FOLLOWING COCAINE SELF-ADMINISTRATION OR EARLY (THIRD DAY) AND LATE (TENTH DAY) EXTINCTION REVEALED ELEVATED LEVELS OF THEIR TRANSCRIPTS. INTERESTINGLY, WE FOUND THE ENRICHMENT OF BRD1 MESSENGER RNA IN RATS SELF-ADMINISTERING COCAINE THAT LASTED UNTIL EXTINCTION TRAINING DURING COCAINE WITHDRAWAL WITH CONCOMITANT INCREASED ACETYLATION OF H3K9 AND H4K8. HOWEVER, DESPITE ELEVATED LEVELS OF METHYL- AND DEMETHYLTRANSFERASE-ENCODED TRANSCRIPTS, NO CHANGES IN GLOBAL DI- AND TRI-METHYLATION OF HISTONE H3 AT LYSINE 4, 9, 27, AND 79 WERE OBSERVED. SURPRISINGLY, AT THE END OF EXTINCTION TRAINING (10 DAYS OF COCAINE WITHDRAWAL), MOST OF THE ANALYZED GENES IN THE RATS ACTIVELY AND PASSIVELY ADMINISTERING COCAINE RETURNED TO THE CONTROL LEVEL. TOGETHER, THE ALTERATIONS IDENTIFIED IN THE RAT PREFRONTAL CORTEX MAY SUGGEST ENHANCED CHROMATIN REMODELING AND TRANSCRIPTIONAL ACTIVITY INDUCED BY EARLY COCAINE ABSTINENCE; HOWEVER, TO KNOW WHETHER THEY ARE BENEFICIAL OR NOT FOR THE EXTINCTION OF DRUG-SEEKING BEHAVIOR, FURTHER IN VIVO EVALUATION IS REQUIRED. 2017 10 1800 27 EFFECT OF HISTONE DEACETYLASE INHIBITOR ON ETHANOL WITHDRAWAL-INDUCED HYPERALGESIA IN RATS. BACKGROUND: INCREASED PAIN SENSITIVITY IS OBSERVED FOLLOWING ALCOHOL WITHDRAWAL, AND ATTEMPTS TO ALLEVIATE THIS HYPERALGESIA CAN CONTRIBUTE TO THE CYCLE OF ADDICTION. THE AIM OF THIS STUDY WAS TO DETERMINE IF ALCOHOL WITHDRAWAL-INDUCED HYPERALGESIA WAS OBSERVED IN A CHRONIC ETHANOL EXPOSURE MODEL AND IF THIS PAIN WAS AFFECTED BY HISTONE DEACETYLASE INHIBITORS, THUS REVEALING AN EPIGENETIC MECHANISM. METHODS: ADULT MALE SPRAGUE DAWLEY RATS RECEIVED LIEBER-DECARLI LIQUID CONTROL OR ETHANOL (9% V/V) DIET FOR 15 DAYS. MECHANICAL SENSITIVITY WAS MEASURED WITH VON FREY HAIR STIMULATION OF THE HINDPAW DURING ETHANOL ADMINISTRATION AND 24- AND 72-HOUR WITHDRAWAL. RESULTS: ETHANOL WITHDRAWAL PRODUCED SEVERE AND SUSTAINED MECHANICAL HYPERALGESIA, AN EFFECT NOT OBSERVED IN THE CONTROL OR ETHANOL-MAINTAINED GROUPS. FURTHERMORE, THIS HYPERALGESIA WAS ATTENUATED BY THE HISTONE DEACETYLASE INHIBITOR, SUBEROYLANILIDE HYDROXAMIC ACID TREATMENT. CONCLUSIONS: HEIGHTENED PAIN SENSITIVITY WAS OBSERVED FOLLOWING WITHDRAWAL FROM CHRONIC ETHANOL EXPOSURE, AND HISTONE DEACETYLASE INHIBITORS COULD BE NOVEL TREATMENTS FOR THIS ALCOHOL WITHDRAWAL-INDUCED HYPERALGESIA. 2019 11 5791 43 STABLE HISTONE METHYLATION CHANGES AT PROTEOGLYCAN NETWORK GENES FOLLOWING ETHANOL EXPOSURE. ALCOHOL USE DISORDER (AUD) IS A CHRONIC MENTAL ILLNESS IN WHICH PATIENTS OFTEN ACHIEVE PROTRACTED PERIODS OF ABSTINENCE PRIOR TO RELAPSE. EPIGENETIC MECHANISMS MAY PROVIDE AN EXPLANATION FOR THE PERSISTING GENE EXPRESSION CHANGES THAT CAN BE OBSERVED EVEN AFTER LONG PERIODS OF ABSTINENCE AND MAY CONTRIBUTE TO RELAPSE. IN THIS STUDY, WE EXAMINED TWO HISTONE MODIFICATIONS, HISTONE 3 LYSINE 4 TRI-METHYLATION (H3K4ME3) AND HISTONE 3 LYSINE 27 TRI-METHYLATION (H3K27ME3), IN THE PREFRONTAL CORTEX OF WITHDRAWAL SEIZURE RESISTANT (WSR) MICE 21 DAYS AFTER 72 H OF ETHANOL VAPOR EXPOSURE. THESE HISTONE MODIFICATIONS WERE SELECTED BECAUSE THEY ARE ASSOCIATED WITH ACTIVE PROMOTERS (H3K4ME3) AND REPRESSED GENE EXPRESSION IN A EUCHROMATIC ENVIRONMENT (H3K27ME3). WE PERFORMED A GENOME-WIDE ANALYSIS TO IDENTIFY DIFFERENCES IN H3K4ME3 AND H3K27ME3 LEVELS IN POST-ETHANOL EXPOSURE VS. CONTROL MICE BY CHIP-SEQ. WE DETECTED A GLOBAL REDUCTION IN H3K4ME3 PEAKS AND INCREASE IN H3K27ME3 PEAKS IN POST-ETHANOL EXPOSURE MICE COMPARED TO CONTROLS, THESE CHANGES ARE CONSISTENT WITH PERSISTENT REDUCTIONS IN GENE EXPRESSION. PATHWAY ANALYSIS OF GENES DISPLAYING CHANGES IN H3K4ME3 AND H3K27ME3 REVEALED ENRICHMENT FOR GENES INVOLVED IN PROTEOGLYCAN AND CALCIUM SIGNALING PATHWAYS, RESPECTIVELY. MICROARRAY ANALYSIS OF 7,683 GENES AND QPCR ANALYSIS IDENTIFIED EIGHT GENES DISPLAYING CONCORDANT REGULATION OF GENE EXPRESSION AND H3K4ME3/H3K27ME3. WE ALSO COMPARED CHANGES IN H3K4ME3 AND/OR H3K27ME3 FROM OUR STUDY WITH CHANGES IN GENE EXPRESSION IN RESPONSE TO ETHANOL FROM PUBLISHED LITERATURE AND WE FOUND THAT THE EXPRESSION OF 52% OF THE GENES WITH ALTERED H3K4ME3 BINDING AND 40% OF GENES WITH H3K27ME3 DIFFERENCES ARE ALTERED BY ETHANOL EXPOSURE. THE CHROMATIN CHANGES ASSOCIATED WITH THE 21-DAY POST-EXPOSURE PERIOD SUGGEST THAT THIS PERIOD IS A UNIQUE STATE IN THE ADDICTION CYCLE THAT DIFFERS FROM ETHANOL INTOXICATION AND ACUTE WITHDRAWAL. THESE RESULTS PROVIDE INSIGHTS INTO THE ENDURING EFFECTS OF ETHANOL ON PROTEOGLYCAN AND CALCIUM SIGNALING GENES IN THE BRAIN. 2018 12 1789 30 EFFECT OF CHRONIC HEROIN AND COCAINE ADMINISTRATION ON GLOBAL DNA METHYLATION IN BRAIN AND LIVER. DRUG ABUSE IS ASSOCIATED WITH EPIGENETIC CHANGES, SUCH AS HISTONE MODIFICATIONS AND DNA METHYLATION. THE PURPOSE OF THE PRESENT STUDY WAS TO EXAMINE THE EFFECT OF CHRONIC COCAINE AND HEROIN ADMINISTRATION ON GLOBAL DNA METHYLATION IN BRAIN AND LIVER. MALE, 8 WEEK OLD, C57BL/6J MICE RECEIVED HEROIN IN A CHRONIC 'INTERMITTENT' ESCALATING DOSE PARADIGM, OR COCAINE IN A CHRONIC ESCALATING DOSE 'BINGE' PARADIGM, WHICH MIMIC THE HUMAN PATTERN OF OPIOID OR COCAINE ABUSE RESPECTIVELY. FOLLOWING SACRIFICE, LIVERS AND BRAINS WERE REMOVED AND DNA WAS EXTRACTED FROM THEM. THE EXTRACTED DNA WAS HYDROLYZED AND 2'-DEOXYCYTIDINE AND 5-METHYL-2'-DEOXYCYTIDINE WERE DETERMINED BY HPLC-UV. THE % 5-METHYL-2'-DEOXYCYTIDINE CONTENT OF DNA WAS SIGNIFICANTLY HIGHER IN THE BRAIN COMPARED TO THE LIVER. THERE WERE NO DIFFERENCES BETWEEN THE CONTROL ANIMALS AND THE COCAINE OR HEROIN TREATED ANIMALS IN NEITHER OF THE TISSUES EXAMINED, WHICH IS SURPRISING SINCE COCAINE ADMINISTRATION INDUCED GROSS MORPHOLOGICAL CHANGES IN THE LIVER. MOREOVER, THERE WAS NO DIFFERENCE IN THE % 5-METHYL-2'-DEOXYCYTIDINE CONTENT OF DNA BETWEEN THE COCAINE AND THE HEROIN TREATED ANIMALS. THE GLOBAL DNA METHYLATION STATUS IN THE BRAIN AND LIVER OF MICE CHRONICALLY TREATED WITH COCAINE OR HEROIN REMAINS UNAFFECTED, BUT THIS FINDING CANNOT EXCLUDE THE EXISTENCE OF ANATOMICAL REGION OR GENE-SPECIFIC METHYLATION DIFFERENCES. THIS IS THE FIRST TIME THAT GLOBAL DNA METHYLATION IN THE LIVER AND WHOLE BRAIN HAS BEEN STUDIED FOLLOWING CHRONIC COCAINE OR HEROIN TREATMENT. 2013 13 2750 42 EXPRESSION LEVELS OF THE TYROSINE HYDROXYLASE GENE AND HISTONE MODIFICATIONS AROUND ITS PROMOTER IN THE LOCUS COERULEUS AND VENTRAL TEGMENTAL AREA OF RATS DURING FORCED ABSTINENCE FROM MORPHINE. BACKGROUND: EPIGENETIC MECHANISMS SUCH AS HISTONE MODIFICATIONS MAY BE INVOLVED IN THE STRUCTURAL AND BEHAVIORAL CHANGES ASSOCIATED WITH ADDICTION. WE STUDIED WHETHER MORPHINE-INDUCED CHANGES IN MRNA LEVELS OF THE CATECHOLAMINE BIOSYNTHESIS ENZYME, TYROSINE HYDROXYLASE (TH), ARE ASSOCIATED WITH HISTONE MODIFICATIONS AROUND THE PROMOTER OF THIS GENE IN THE LOCUS COERULEUS (LC) AND VENTRAL TEGMENTAL AREA (VTA) OF RATS. METHODS: DEPENDENCE WAS INDUCED IN RATS BY INTRAPERITONEAL INJECTIONS OF MORPHINE FOR 11 DAYS. THE ANIMALS WERE KILLED 2 H (CHRONIC MORPHINE), 24 H AND 7 DAYS (SPONTANEOUS WITHDRAWAL) AFTER THE LAST INJECTION OF MORPHINE. RESULTS: ANALYSIS OF OUR REAL-TIME QUANTITATIVE REVERSE TRANSCRIPTION PCR RESULTS BY 1-WAY ANOVA SHOWED SIGNIFICANT UPREGULATION (5.13 +/- 0.39 FOLDS) OF LC LEVELS OF THE TH TRANSCRIPT 24 H AFTER THE LAST INJECTION OF MORPHINE TO RATS, WHEN COMPARED WITH 2 H AND 7 DAYS TIME POINTS. CHRONIC MORPHINE AND MORPHINE ABSTINENCE FAILED TO CAUSE ANY SIGNIFICANT CHANGES IN THE LEVELS OF TH MRNA IN THE VTA AFTER CESSATION OF MORPHINE. CONSISTENTLY, CHROMATIN IMMUNOPRECIPITATION REAL-TIME QUANTITATIVE PCR ASSAYS REVEALED THAT 24 H AFTER THE LAST INJECTION OF MORPHINE, LEVELS OF H3 ACETYLATION WERE SIGNIFICANTLY INCREASED (4.12 +/- 0.38 FOLDS) AT THE PROMOTER OF THE TH GENE IN THE LC BUT NOT IN THE VTA. OUR DATA ALSO SHOWED THAT HISTONE H3 TRIMETHYLATION FAILED TO CHANGE AROUND THE TH GENE PROMOTER EITHER IN THE VTA OR IN THE LC AFTER MORPHINE ABSTINENCE. CONCLUSIONS: RESULTS OF THE PRESENT STUDY, FOR THE FIRST TIME, DEMONSTRATE THE INVOLVEMENT OF HISTONE H3 ACETYLATION IN THE REGULATION OF TH GENE EXPRESSION IN THE LC OF RATS DURING FORCED ABSTINENCE FROM MORPHINE. 2018 14 5485 36 REVERSAL OF COCAINE-CONDITIONED PLACE PREFERENCE THROUGH METHYL SUPPLEMENTATION IN MICE: ALTERING GLOBAL DNA METHYLATION IN THE PREFRONTAL CORTEX. ANALYSIS OF GLOBAL METHYLATION IN CELLS HAS REVEALED CORRELATIONS BETWEEN OVERALL DNA METHYLATION STATUS AND SOME BIOLOGICAL STATES. RECENT STUDIES SUGGEST THAT EPIGENETIC REGULATION THROUGH DNA METHYLATION COULD BE RESPONSIBLE FOR NEUROADAPTATIONS INDUCED BY ADDICTIVE DRUGS. HOWEVER, THERE IS NO INVESTIGATION TO DETERMINE GLOBAL DNA METHYLATION STATUS FOLLOWING REPEATED EXPOSURE TO ADDICTIVE DRUGS. USING MICE CONDITIONED PLACE PREFERENCE (CPP) PROCEDURE, WE MEASURED GLOBAL DNA METHYLATION LEVEL IN THE NUCLEUS ACCUMBENS (NAC) AND THE PREFRONTAL CORTEX (PFC) ASSOCIATED WITH DRUG REWARDING EFFECTS. WE FOUND THAT COCAINE-, BUT NOT MORPHINE- OR FOOD-CPP TRAINING DECREASED GLOBAL DNA METHYLATION IN THE PFC. CHRONIC TREATMENT WITH METHIONINE, A METHYL DONOR, FOR 25 CONSECUTIVE DAYS PRIOR TO AND DURING CPP TRAINING INHIBITED THE ESTABLISHMENT OF COCAINE, BUT NOT MORPHINE OR FOOD CPP. WE ALSO FOUND THAT BOTH MRNA AND PROTEIN LEVEL OF DNMT (DNA METHYTRANSFERASE) 3B IN THE PFC WERE DOWNREGULATED FOLLOWING THE ESTABLISHMENT OF COCAINE CPP, AND THE DOWNREGULATION COULD BE REVERSED BY REPEATED ADMINISTRATION OF METHIONINE. OUR STUDY INDICATES A CRUCIAL ROLE OF GLOBAL PFC DNA HYPOMETHYLATION IN THE REWARDING EFFECTS OF COCAINE. REVERSAL OF GLOBAL DNA HYPOMETHYLATION COULD SIGNIFICANTLY ATTENUATE THE REWARDING EFFECTS INDUCED BY COCAINE. OUR RESULTS SUGGEST THAT METHIONINE MAY HAVE BECOME A POTENTIAL THERAPEUTIC TARGET TO TREAT COCAINE ADDICTION. 2012 15 917 44 CHRONIC HIGH-FAT DIET DRIVES POSTNATAL EPIGENETIC REGULATION OF MU-OPIOID RECEPTOR IN THE BRAIN. OPIOID SYSTEM DYSREGULATION HAS BEEN OBSERVED IN BOTH GENETIC AND HIGH-FAT DIET (HFD)-INDUCED MODELS OF OBESITY. AN UNDERSTANDING OF THE MOLECULAR MECHANISMS OF MOR TRANSCRIPTIONAL REGULATION, PARTICULARLY WITHIN AN IN VIVO CONTEXT, IS LACKING. USING A DIET-INDUCED MODEL OF OBESITY (DIO), MICE WERE FED A HIGH-FAT DIET (60% CALORIES FROM FAT) FROM WEANING TO >18 WEEKS OF AGE. COMPARED WITH MICE FED THE CONTROL DIET, DIO MICE HAD A DECREASED PREFERENCE FOR SUCROSE. MOR MRNA EXPRESSION WAS DECREASED IN REWARD-RELATED CIRCUITRY (VENTRAL TEGMENTAL AREA (VTA), NUCLEUS ACCUMBENS (NAC), AND PREFRONTAL CORTEX (PFC)) BUT NOT THE HYPOTHALAMUS, IMPORTANT IN THE HOMEOSTATIC REGULATION OF FEEDING. DNA METHYLATION IS AN EPIGENETIC MODIFICATION THAT LINKS ENVIRONMENTAL EXPOSURES TO ALTERED GENE EXPRESSION. WE FOUND A SIGNIFICANT INCREASE IN DNA METHYLATION IN THE MOR PROMOTER REGION WITHIN THE REWARD-RELATED BRAIN REGIONS. METHYL CPG-BINDING PROTEIN 2 (MECP2) CAN BIND METHYLATED DNA AND REPRESS TRANSCRIPTION, AND DIO MICE SHOWED INCREASED BINDING OF MECP2 TO THE MOR PROMOTER IN REWARD-RELATED REGIONS OF THE BRAIN. FINALLY, USING CHIP ASSAYS WE EXAMINED H3K9 METHYLATION (INACTIVE CHROMATIN) AND H3 ACETYLATION (ACTIVE CHROMATIN) WITHIN THE MOR PROMOTER REGION AND FOUND INCREASED H3K9 METHYLATION AND DECREASED H3 ACETYLATION. THESE DATA ARE THE FIRST TO IDENTIFY DNA METHYLATION, MECP2 RECRUITMENT, AND CHROMATIN REMODELING AS MECHANISMS LEADING TO TRANSCRIPTIONAL REPRESSION OF MOR IN THE BRAINS OF MICE FED A HIGH-FAT DIET. 2011 16 5624 32 SELECTIVE BOOSTING OF TRANSCRIPTIONAL AND BEHAVIORAL RESPONSES TO DRUGS OF ABUSE BY HISTONE DEACETYLASE INHIBITION. HISTONE ACETYLATION AND OTHER MODIFICATIONS OF THE CHROMATIN ARE IMPORTANT REGULATORS OF GENE EXPRESSION AND, CONSEQUENTLY, MAY CONTRIBUTE TO DRUG-INDUCED BEHAVIORS AND NEUROPLASTICITY. EARLIER STUDIES HAVE SHOWN THAT A REDUCTION IN HISTONE DEACETYLASE (HDAC) ACTIVITY RESULTS IN THE ENHANCEMENT OF SOME PSYCHOSTIMULANT-INDUCED BEHAVIORS. IN THIS STUDY, WE EXTEND THOSE SEMINAL FINDINGS BY SHOWING THAT THE ADMINISTRATION OF THE HDAC INHIBITOR SODIUM BUTYRATE ENHANCES MORPHINE-INDUCED LOCOMOTOR SENSITIZATION AND CONDITIONED PLACE PREFERENCE. IN CONTRAST, THIS COMPOUND HAS NO EFFECTS ON THE DEVELOPMENT OF MORPHINE TOLERANCE AND DEPENDENCE. SIMILAR EFFECTS WERE OBSERVED FOR COCAINE AND ETHANOL-INDUCED BEHAVIORS. THESE BEHAVIORAL CHANGES WERE ACCOMPANIED BY A SELECTIVE BOOSTING OF A COMPONENT OF THE TRANSCRIPTIONAL PROGRAM ACTIVATED BY CHRONIC MORPHINE ADMINISTRATION THAT INCLUDED CIRCADIAN CLOCK GENES AND OTHER GENES RELEVANT TO ADDICTIVE BEHAVIOR. OUR RESULTS SUPPORT A SPECIFIC FUNCTION FOR HISTONE ACETYLATION AND THE EPIGENETIC MODULATION OF TRANSCRIPTION AT A REDUCED NUMBER OF BIOLOGICALLY RELEVANT LOCI ON NON-HOMEOSTATIC, LONG-LASTING, DRUG-INDUCED BEHAVIORAL PLASTICITY. 2009 17 531 44 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 18 2705 36 EXERCISE AND LOW-LEVEL GABA(A) RECEPTOR INHIBITION MODULATE LOCOMOTOR ACTIVITY AND THE EXPRESSION OF BDNF ACCOMPANIED BY CHANGES IN EPIGENETIC REGULATION IN THE HIPPOCAMPUS. AEROBIC EXERCISE IS KNOWN TO INCREASE EXPRESSION OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IN THE HIPPOCAMPUS AND TO IMPROVE COGNITIVE FUNCTION. THE INHIBITION OF GABAERGIC SYNAPSES ENHANCES HIPPOCAMPAL PLASTICITY AS WELL AS LEARNING AND MEMORY. THE OBJECTIVE OF THE PRESENT STUDY WAS TO EXAMINE THE INTERACTIVE EFFECT OF LOW-LEVEL GABA(A) RECEPTOR INHIBITION AND EXERCISE ON BEHAVIOR TESTS (COGNITIVE FUNCTION AND LOCOMOTOR ACTIVITY), EXPRESSION OF BDNF AND EPIGENETIC REGULATIONS INCLUDING THE ACTIVITY LEVELS OF HISTONE ACETYLTRANSFERASES (HATS) AND HISTONE DEACETYLASES (HDACS) IN THE HIPPOCAMPUS. ICR MICE WERE DIVIDED INTO TWO GROUPS: THOSE WHO DID NOT PARTICIPATE IN EXERCISE AND THOSE WHO PARTICIPATED IN EXERCISE. EACH GROUP WAS SUBDIVIDED INTO TWO OTHER GROUPS: THE ONE WHO RECEIVED VEHICLE AND THE ONE WHO RECEIVED GABA(A) RECEPTOR ANTAGONIST, BICUCULLIN. WE ADMINISTERED SALINE OR BICUCULLINE INTRAPERITONEALLY TO THE MICE AT A NON-EPILEPTIC DOSE OF 0.25 MG/KG, WHEREAS THE MICE WERE EXERCISED ON A TREADMILL FOR APPROXIMATELY 1 H A DAY, 5 DAYS A WEEK FOR 4 WEEKS. NOVEL-OBJECT RECOGNITION TEST AND LOCOMOTOR ACTIVITY WERE ASSESSED AT A REST DAY APPROXIMATELY 4 DAYS BEFORE THE EUTHANASIA. THE MICE WERE EUTHANIZED 4 H AFTER THE LAST EXERCISE SESSION. AEROBIC EXERCISE FOR 4 WEEKS INCREASED MRNA AND PROTEIN EXPRESSION OF BDNF IN THE HIPPOCAMPUS, ACCOMPANIED BY ENHANCED HAT ACTIVITY. ALTERNATIVELY, BICUCULLINE ADMINISTRATION INCREASED HDAC ACTIVITY IN THE HIPPOCAMPUS. FURTHERMORE, EXERCISE IN THE PRESENCE OF BICUCULLINE ADMINISTRATION INCREASED LOCOMOTOR ACTIVITY, INDICATING THAT EXERCISE COMBINED WITH LOW-LEVEL GABA(A) RECEPTOR INHIBITION POTENTIATED THE ACTIVITY OF THE MICE. ALTOGETHER, THE PRESENT STUDY SUGGESTED THAT EXERCISE BENEFICIALLY CONTRIBUTES TO NEUROPROTECTION IN THE HIPPOCAMPUS ACCOMPANIED BY THE UP-REGULATION OF BDNF EXPRESSION AND EPIGENETIC REGULATION, WHEREAS THE CHRONIC INHIBITION OF GABA(A) RECEPTOR POTENTIATES EXERCISE-INDUCED BEHAVIORAL ACTIVITY. 2018 19 2740 34 EXPOSURE TO EARLY LIFE STRESS RESULTS IN EPIGENETIC CHANGES IN NEUROTROPHIC FACTOR GENE EXPRESSION IN A PARKINSONIAN RAT MODEL. EARLY LIFE ADVERSITY INCREASES THE RISK OF MENTAL DISORDERS LATER IN LIFE. CHRONIC EARLY LIFE STRESS MAY ALTER NEUROTROPHIC FACTOR GENE EXPRESSION INCLUDING THOSE FOR BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) AND GLIAL CELL DERIVED NEUROTROPHIC FACTOR (GDNF) THAT ARE IMPORTANT IN NEURONAL GROWTH, SURVIVAL, AND MAINTENANCE. MATERNAL SEPARATION WAS USED IN THIS STUDY TO MODEL EARLY LIFE STRESS. FOLLOWING UNILATERAL INJECTION OF A MILD DOSE OF 6-HYDROXYDOPAMINE (6-OHDA), WE MEASURED CORTICOSTERONE (CORT) IN THE BLOOD AND STRIATUM OF STRESSED AND NONSTRESSED RATS; WE ALSO MEASURED DNA METHYLATION AND BDNF AND GDNF GENE EXPRESSION IN THE STRIATUM USING REAL TIME PCR. IN THE PRESENCE OF STRESS, WE FOUND THAT THERE WAS INCREASED CORTICOSTERONE CONCENTRATION IN BOTH BLOOD AND STRIATAL TISSUE. FURTHER TO THIS, WE FOUND HIGHER DNA METHYLATION AND DECREASED NEUROTROPHIC FACTOR GENE EXPRESSION. 6-OHDA LESION INCREASED NEUROTROPHIC FACTOR GENE EXPRESSION IN BOTH STRESSED AND NONSTRESSED RATS BUT THIS INCREASE WAS HIGHER IN THE NONSTRESSED RATS. OUR RESULTS SUGGEST THAT EXPOSURE TO EARLY POSTNATAL STRESS INCREASES CORTICOSTERONE CONCENTRATION WHICH LEADS TO INCREASED DNA METHYLATION. THIS EFFECT RESULTS IN DECREASED BDNF AND GDNF GENE EXPRESSION IN THE STRIATUM LEADING TO DECREASED PROTECTION AGAINST SUBSEQUENT INSULTS LATER IN LIFE. 2016 20 213 28 ACUTE AND CHRONIC ELECTROCONVULSIVE SEIZURES (ECS) DIFFERENTIALLY REGULATE THE EXPRESSION OF EPIGENETIC MACHINERY IN THE ADULT RAT HIPPOCAMPUS. BACKGROUND: ELECTROCONVULSIVE SEIZURE TREATMENT IS A FAST-ACTING ANTIDEPRESSANT THERAPY THAT EVOKES RAPID TRANSCRIPTIONAL, NEUROGENIC, AND BEHAVIORAL CHANGES. EPIGENETIC MECHANISMS CONTRIBUTE TO ALTERED GENE REGULATION, WHICH UNDERLIES THE NEUROGENIC AND BEHAVIORAL EFFECTS OF ELECTROCONVULSIVE SEIZURE. WE HYPOTHESIZED THAT ELECTROCONVULSIVE SEIZURE MAY MODULATE THE EXPRESSION OF EPIGENETIC MACHINERY, THUS ESTABLISHING POTENTIAL ALTERATIONS IN THE EPIGENETIC LANDSCAPE. METHODS: WE EXAMINED THE INFLUENCE OF ACUTE AND CHRONIC ELECTROCONVULSIVE SEIZURE ON THE GENE EXPRESSION OF HISTONE MODIFIERS, NAMELY HISTONE ACETYLTRANSFERASES, HISTONE DEACETYLASES, HISTONE METHYLTRANSFERASES, AND HISTONE (LYSINE) DEMETHYLASES AS WELL AS DNA MODIFYING ENZYMES, INCLUDING DNA METHYLTRANSFERASES, DNA DEMETHYLASES, AND METHYL-CPG-BINDING PROTEINS IN THE HIPPOCAMPI OF ADULT MALE WISTAR RATS USING QUANTITATIVE REAL TIME-PCR ANALYSIS. FURTHER, WE EXAMINED THE INFLUENCE OF ACUTE AND CHRONIC ELECTROCONVULSIVE SEIZURE ON GLOBAL AND RESIDUE-SPECIFIC HISTONE ACETYLATION AND METHYLATION LEVELS WITHIN THE HIPPOCAMPUS, A BRAIN REGION IMPLICATED IN THE CELLULAR AND BEHAVIORAL EFFECTS OF ELECTROCONVULSIVE SEIZURE. RESULTS: ACUTE AND CHRONIC ELECTROCONVULSIVE SEIZURE INDUCED A PRIMARILY UNIQUE, AND IN CERTAIN CASES BIDIRECTIONAL, REGULATION OF HISTONE AND DNA MODIFIERS, AND METHYL-CPG-BINDING PROTEINS, WITH AN OVERLAPPING PATTERN OF GENE REGULATION RESTRICTED TO SIRT4, MLL3, JMJD3, GADD45B, TET2, AND TET3. GLOBAL HISTONE ACETYLATION AND METHYLATION LEVELS WERE PREDOMINANTLY UNCHANGED, WITH THE EXCEPTION OF A SIGNIFICANT DECLINE IN H3K9 ACETYLATION IN THE HIPPOCAMPUS FOLLOWING CHRONIC ELECTROCONVULSIVE SEIZURE. CONCLUSIONS: ELECTROCONVULSIVE SEIZURE TREATMENT EVOKES THE TRANSCRIPTIONAL REGULATION OF SEVERAL HISTONE AND DNA MODIFIERS, AND METHYL-CPG-BINDING PROTEINS WITHIN THE HIPPOCAMPUS, WITH A PREDOMINANTLY DISTINCT PATTERN OF REGULATION INDUCED BY ACUTE AND CHRONIC ELECTROCONVULSIVE SEIZURE. 2016