1 5443 161 REPEATED METHAMPHETAMINE AND MODAFINIL INDUCE DIFFERENTIAL COGNITIVE EFFECTS AND SPECIFIC HISTONE ACETYLATION AND DNA METHYLATION PROFILES IN THE MOUSE MEDIAL PREFRONTAL CORTEX. METHAMPHETAMINE (METH) AND MODAFINIL ARE PSYCHOSTIMULANTS WITH DIFFERENT LONG-TERM COGNITIVE PROFILES: METH IS ADDICTIVE AND LEADS TO COGNITIVE DECLINE, WHEREAS MODAFINIL HAS LITTLE ABUSE LIABILITY AND IS A COGNITIVE ENHANCER. INCREASING EVIDENCE IMPLICATES EPIGENETIC MECHANISMS OF GENE REGULATION BEHIND THE LASTING CHANGES THAT DRUGS OF ABUSE AND OTHER PSYCHOTROPIC COMPOUNDS INDUCE IN THE BRAIN, LIKE THE CONTROL OF GENE EXPRESSION BY HISTONES 3 AND 4 TAILS ACETYLATION (H3AC AND H4AC) AND DNA CYTOSINE METHYLATION (5-MC). MICE WERE TREATED WITH A SEVEN-DAY REPEATED METH, MODAFINIL OR VEHICLE PROTOCOL AND EVALUATED IN THE NOVEL OBJECT RECOGNITION (NOR) TEST OR SACRIFICED 4DAYS AFTER LAST INJECTION FOR MOLECULAR ASSAYS. WE EVALUATED TOTAL H3AC, H4AC AND 5-MC LEVELS IN THE MEDIAL PREFRONTAL CORTEX (MPFC), H3AC AND H4AC PROMOTOR ENRICHMENT (CHIP) AND MRNA EXPRESSION (RT-PCR) OF NEUROTRANSMITTER SYSTEMS INVOLVED IN AROUSAL, WAKEFULNESS AND COGNITIVE CONTROL, LIKE DOPAMINERGIC (DRD1 AND DRD2), ALPHA-ADRENERGIC (ADRA1A AND ADRA1B), OREXINERGIC (HCRTR1 AND HCRTR2), HISTAMINERGIC (HRH1 AND HRH3) AND GLUTAMATERGIC (AMPA GRIA1 AND NMDA GRIN1) RECEPTORS. REPEATED METH AND MODAFINIL TREATMENT ELICITED DIFFERENT COGNITIVE OUTCOMES IN THE NOR TEST, WHERE MODAFINIL-TREATED MICE PERFORMED AS CONTROLS AND METH-TREATED MICE SHOWED IMPAIRED RECOGNITION MEMORY. METH-TREATED MICE ALSO SHOWED I) DECREASED LEVELS OF TOTAL H3AC AND H4AC, AND INCREASED LEVELS OF 5-MC, II) DECREASED H3AC ENRICHMENT AT PROMOTERS OF DRD2, HCRTR1/2, HRH1 AND GRIN1, AND INCREASED H4AC ENRICHMENT AT DRD1, HRH1 AND GRIN1, III) INCREASED MRNA OF DRD1A, GRIN1 AND GRIA1. MODAFINIL-TREATED MICE SHARED NONE OF THESE EFFECTS AND SHOWED INCREASED H3AC ENRICHMENT AND MRNA EXPRESSION AT ADRA1B. MODAFINIL AND METH SHOWED SIMILAR EFFECTS LINKED TO DECREASED H3AC IN HRH3, INCREASED H4AC IN HCRTR1, AND DECREASED MRNA EXPRESSION OF HCRTR2. THE SPECIFIC METH-INDUCED EPIGENETIC AND TRANSCRIPTIONAL CHANGES DESCRIBED HERE MAY BE RELATED TO THE LONG-TERM COGNITIVE DECLINE EFFECTS OF THE DRUG AND ITS DETRIMENTAL EFFECTS ON MPFC FUNCTION. THE LACK OF SIMILAR EPIGENETIC EFFECTS OF CHRONIC MODAFINIL ADMINISTRATION SUPPORTS THIS NOTION. 2018 2 6095 85 THE EFFECTS OF SINGLE-DOSE INJECTIONS OF MODAFINIL AND METHAMPHETAMINE ON EPIGENETIC AND FUNCTIONAL MARKERS IN THE MOUSE MEDIAL PREFRONTAL CORTEX: POTENTIAL ROLE OF DOPAMINE RECEPTORS. METH USE CAUSES NEUROADAPTATIONS THAT NEGATIVELY IMPACT THE PREFRONTAL CORTEX (PFC) LEADING TO ADDICTION AND ASSOCIATED COGNITIVE DECLINE IN ANIMALS AND HUMANS. IN CONTRAST, MODAFINIL ENHANCES COGNITION BY INCREASING PFC FUNCTION. ACCUMULATED EVIDENCE INDICATES THAT PSYCHOSTIMULANT DRUGS, INCLUDING MODAFINIL AND METH, REGULATE GENE EXPRESSION VIA EPIGENETIC MODIFICATIONS. IN THIS STUDY, WE MEASURED THE EFFECTS OF SINGLE-DOSE INJECTIONS OF MODAFINIL AND METH ON THE PROTEIN LEVELS OF ACETYLATED HISTONE H3 (H3AC) AND H4AC, DEACETYLASES HDAC1 AND HDAC2, AND OF THE NMDA SUBUNIT GLUN1 IN THE MEDIAL PFC (MPFC) OF MICE EUTHANIZED 1 H AFTER DRUG ADMINISTRATION. TO TEST IF DOPAMINE (DA) RECEPTORS (DRS) PARTICIPATE IN THE BIOCHEMICAL EFFECTS OF THE TWO DRUGS, WE INJECTED THE D1RS ANTAGONIST, SCH23390, OR THE D2RS ANTAGONIST, RACLOPRIDE, 30 MIN BEFORE ADMINISTRATION OF METH AND MODAFINIL. WE EVALUATED EACH DRUG EFFECT ON GLUTAMATE SYNAPTIC TRANSMISSION IN D1R-EXPRESSING LAYER V PYRAMIDAL NEURONS. WE ALSO MEASURED THE ENRICHMENT OF H3AC AND H4AC AT THE PROMOTERS OF SEVERAL GENES INCLUDING DA, NE, OREXIN, HISTAMINE, AND GLUTAMATE RECEPTORS, AND THEIR MRNA EXPRESSION, SINCE THEY ARE RESPONSIVE TO CHRONIC MODAFINIL AND METH TREATMENT. ACUTE MODAFINIL AND METH INJECTIONS CAUSED SIMILAR EFFECTS ON TOTAL HISTONE ACETYLATION, INCREASING H3AC AND DECREASING H4AC, AND THEY ALSO INCREASED HDAC1, HDAC2 AND GLUN1 PROTEIN LEVELS IN THE MOUSE MPFC. IN ADDITION, THE EFFECTS OF THE DRUGS WERE PREVENTED BY PRE-TREATMENT WITH D1RS AND D2RS ANTAGONISTS. SPECIFICALLY, THE CHANGES IN H4AC, HDAC2, AND GLUN1 WERE RESPONSIVE TO SCH23390, WHEREAS THOSE OF H3AC AND GLUN1 WERE RESPONSIVE TO RACLOPRIDE. WHOLE-CELL PATCH CLAMP IN TRANSGENIC BAC-DRD1A-TDTOMATO MICE SHOWED THAT METH, BUT NOT MODAFINIL, INDUCED PAIRED-PULSE FACILITATION OF EPSCS, SUGGESTING REDUCED PRESYNAPTIC PROBABILITY OF GLUTAMATE RELEASE ONTO LAYER V PYRAMIDAL NEURONS. ANALYSIS OF HISTONE 3/4 ENRICHMENT AT SPECIFIC PROMOTERS REVEALED: I) DISTINCT EFFECTS OF THE DRUGS ON HISTONE 3 ACETYLATION, WITH MODAFINIL INCREASING H3AC AT DRD1 AND ADRA1B PROMOTERS, BUT METH INCREASING H3AC AT ADRA1A; II) DISTINCT EFFECTS ON HISTONE 4 ACETYLATION ENRICHMENT, WITH MODAFINIL INCREASING H4AC AT THE DRD2 PROMOTER AND DECREASING IT AT HRH1, BUT METH INCREASING H4AC AT DRD1; III) COMPARABLE EFFECTS OF BOTH PSYCHOSTIMULANTS, INCREASING H3AC AT DRD2, HCRTR1, AND HRH1 PROMOTERS, DECREASING H3AC AT HRH3, INCREASING H4AC AT HCRTR1, AND DECREASING H4AC AT HCRTR2, HRH3, AND GRIN1 PROMOTERS. INTERESTINGLY, ONLY METH ALTERED MRNA LEVELS OF GENES WITH ALTERED HISTONE ACETYLATION STATUS, INDUCING INCREASED EXPRESSION OF DRD1A, ADRA1A, HCRTR1, AND HRH1, AND DECREASING GRIN1. OUR STUDY SUGGESTS THAT ALTHOUGH ACUTE METH AND MODAFINIL CAN BOTH INCREASE DA NEUROTRANSMISSION IN THE MPFC, THERE ARE SIMILAR AND CONTRASTING EPIGENETIC AND TRANSCRIPTIONAL CONSEQUENCES THAT MAY ACCOUNT FOR THEIR DIVERGENT CLINICAL EFFECTS. 2019 3 4212 40 METHAMPHETAMINE DOWNREGULATES STRIATAL GLUTAMATE RECEPTORS VIA DIVERSE EPIGENETIC MECHANISMS. BACKGROUND: CHRONIC METHAMPHETAMINE (METH) EXPOSURE CAUSES NEUROADAPTATIONS AT GLUTAMATERGIC SYNAPSES. METHODS: TO IDENTIFY THE METH-INDUCED EPIGENETIC UNDERPINNINGS OF THESE NEUROADAPTATIONS, WE INJECTED INCREASING METH DOSES TO RATS FOR 2 WEEKS AND MEASURED STRIATAL GLUTAMATE RECEPTOR EXPRESSION. WE THEN QUANTIFIED THE EFFECTS OF METH EXPOSURE ON HISTONE ACETYLATION. WE ALSO MEASURED METH-INDUCED CHANGES IN DNA METHYLATION AND DNA HYDROXYMETHYLATION. RESULTS: CHRONIC METH DECREASED TRANSCRIPT AND PROTEIN EXPRESSION OF GLUA1 AND GLUA2 ALPHA-AMINO-3-HYDROXY-5-METHYL-4-ISOXAZOLE PROPIONIC ACID RECEPTOR (AMPAR) AND GLUN1 N-METHYL-D-ASPARTATE RECEPTOR SUBUNITS. THESE CHANGES WERE ASSOCIATED WITH ALTERED ELECTROPHYSIOLOGICAL GLUTAMATERGIC RESPONSES IN STRIATAL NEURONS. CHROMATIN IMMUNOPRECIPITATION-POLYMERASE CHAIN REACTION REVEALED THAT METH DECREASED ENRICHMENT OF ACETYLATED HISTONE H4 ON GLUA1, GLUA2, AND GLUN1 PROMOTERS. METHAMPHETAMINE EXPOSURE ALSO INCREASED REPRESSOR ELEMENT-1 SILENCING TRANSCRIPTION FACTOR (REST) COREPRESSOR 1, METHYLATED CPG BINDING PROTEIN 2, AND HISTONE DEACETYLASE 2 ENRICHMENT, BUT NOT OF SIRTUIN 1 OR SIRTUIN 2, ONTO GLUA1 AND GLUA2 GENE SEQUENCES. MOREOVER, METH CAUSED INTERACTIONS OF REST COREPRESSOR 1 AND METHYLATED CPG BINDING PROTEIN 2 WITH HISTONE DEACETYLASE 2 AND OF REST WITH HISTONE DEACETYLASE 1. SURPRISINGLY, METHYLATED DNA IMMUNOPRECIPITATION AND HYDROXYMETHYLATED DNA IMMUNOPRECIPITATION-POLYMERASE CHAIN REACTION REVEALED METH-INDUCED DECREASED ENRICHMENT OF 5-METHYLCYTOSINE AND 5-HYDROXYMETHYLCYTOSINE AT GLUA1 AND GLUA2 PROMOTER SEQUENCES. IMPORTANTLY, THE HISTONE DEACETYLASE INHIBITOR, VALPROIC ACID, BLOCKED METH-INDUCED DECREASED EXPRESSION OF AMPAR AND N-METHYL-D-ASPARTATE RECEPTOR SUBUNITS. FINALLY, VALPROIC ACID ALSO ATTENUATED METH-INDUCED DECREASE H4K16AC RECRUITMENT ON AMPAR GENE SEQUENCES. CONCLUSIONS: THESE OBSERVATIONS SUGGEST THAT HISTONE H4 HYPOACETYLATION MAY BE THE MAIN DETERMINANT OF METH-INDUCED DECREASED STRIATAL GLUTAMATE RECEPTOR EXPRESSION. 2014 4 949 40 CHRONIC METHAMPHETAMINE TREATMENT REDUCES THE EXPRESSION OF SYNAPTIC PLASTICITY GENES AND CHANGES THEIR DNA METHYLATION STATUS IN THE MOUSE BRAIN. METHAMPHETAMINE (METH) IS A HIGHLY ADDICTIVE PSYCHOSTIMULANT THAT MAY CAUSE LONG-LASTING SYNAPTIC DYSFUNCTION AND ABNORMAL GENE EXPRESSION. WE AIMED TO EXPLORE THE DIFFERENTIAL EXPRESSION OF SYNAPTIC PLASTICITY GENES IN CHRONIC METH-TREATED MOUSE BRAIN. WE USED THE RT(2) PROFILER PCR ARRAY AND THE REAL-TIME QUANTITATIVE PCR TO CHARACTERIZE DIFFERENTIALLY EXPRESSED SYNAPTIC PLASTICITY GENES IN THE FRONTAL CORTEX AND THE HIPPOCAMPUS OF CHRONIC METH-TREATED MICE COMPARED WITH NORMAL SALINE-TREATED MICE. WE FURTHER USED PYROSEQUENCING TO ASSESS DNA METHYLATION CHANGES IN THE CPG REGION OF THE FIVE IMMEDIATE EARLY GENES (IEGS) IN CHRONIC METH-TREATED MOUSE BRAIN. WE DETECTED SIX DOWNREGULATED GENES IN THE FRONTAL CORTEX AND THE HIPPOCAMPUS OF CHRONIC METH-TREATED MICE, INCLUDING FIVE IEGS (ARC, EGR2, FOS, KLF10, AND NR4A1) AND ONE NEURONAL RECEPTOR GENE (GRM1), COMPARED WITH NORMAL SALINE-TREATED GROUP, BUT ONLY FOUR GENES (ARC, EGR2, FOS, AND NR4A1) WERE CONFIRMED TO BE DIFFERENT. FURTHERMORE, WE FOUND SEVERAL CPG SITES OF THE ARC AND THE FOS THAT HAD SIGNIFICANT CHANGES IN DNA METHYLATION STATUS IN THE FRONTAL CORTEX OF CHRONIC METH-TREATED MICE, WHILE THE KLF10 AND THE NR4A1 THAT HAD SIGNIFICANT CHANGES IN THE HIPPOCAMPUS. OUR RESULTS SHOW THAT CHRONIC ADMINISTRATION OF METH MAY LEAD TO SIGNIFICANT DOWNREGULATION OF THE IEGS EXPRESSION IN BOTH THE FRONTAL CORTEX AND THE HIPPOCAMPUS, WHICH MAY PARTLY ACCOUNT FOR THE MOLECULAR MECHANISM OF THE ACTION OF METH. FURTHERMORE, THE CHANGES IN DNA METHYLATION STATUS OF THE IEGS IN THE BRAIN INDICATE THAT AN EPIGENETIC MECHANISM-DEPENDENT TRANSCRIPTIONAL REGULATION MAY CONTRIBUTE TO METH ADDICTION, WHICH WARRANTS ADDITIONAL STUDY. 2015 5 2118 33 EPIGENETIC HISTONE METHYLATION OF PPARGAMMA AND CPT1A SIGNALING CONTRIBUTES TO BETAHISTINE PREVENTING OLANZAPINE-INDUCED DYSLIPIDEMIA. AS A PARTIAL HISTAMINE H1 RECEPTOR AGONIST AND H3 ANTAGONIST, BETAHISTINE HAS BEEN REPORTED TO PARTIALLY PREVENT OLANZAPINE-INDUCED DYSLIPIDEMIA AND OBESITY THROUGH A COMBINATION THERAPY, ALTHOUGH THE UNDERLYING EPIGENETIC MECHANISMS ARE STILL NOT KNOWN. RECENT STUDIES HAVE REVEALED THAT HISTONE REGULATION OF KEY GENES FOR LIPOGENESIS AND ADIPOGENESIS IN THE LIVER IS ONE OF THE CRUCIAL MECHANISMS FOR OLANZAPINE-INDUCED METABOLIC DISORDERS. THIS STUDY INVESTIGATED THE ROLE OF EPIGENETIC HISTONE REGULATION IN BETAHISTINE CO-TREATMENT PREVENTING DYSLIPIDEMIA AND FATTY LIVER CAUSED BY CHRONIC OLANZAPINE TREATMENT IN A RAT MODEL. IN ADDITION TO ABNORMAL LIPID METABOLISM, THE UPREGULATION OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR GAMMA (PPARGAMMA) AND CCAAT/ENHANCER BINDING PROTEIN (C/EBPALPHA), AS WELL AS THE DOWNREGULATION OF CARNITINE PALMITOYLTRANSFERASE 1A (CPT1A) IN THE LIVER INDUCED BY OLANZAPINE, WERE SIGNIFICANTLY ATTENUATED BY BETAHISTINE CO-TREATMENT. IN ADDITION, BETAHISTINE CO-TREATMENT SIGNIFICANTLY ENHANCED THE GLOBAL EXPRESSION OF H3K4ME AND THE ENRICHMENT OF H3K4ME BINDING ON THE PROMOTER OF CPT1A GENE AS REVEALED BY CHIP-QPCR, BUT INHIBITED THE EXPRESSION OF ONE OF ITS SITE-SPECIFIC DEMETHYLASES, LYSINE (K)-SPECIFIC DEMETHYLASE 1A (KDM1A). BETAHISTINE CO-TREATMENT ALSO SIGNIFICANTLY ENHANCED THE GLOBAL EXPRESSION OF H3K9ME AND THE ENRICHMENT OF H3K9ME BINDING ON THE PROMOTER OF THE PPARG GENE, BUT INHIBITED THE EXPRESSION OF TWO OF ITS SITE-SPECIFIC DEMETHYLASES, LYSINE DEMETHYLASE 4B (KDM4B) AND PHD FINGER PROTEIN 2 (PHF2). THESE RESULTS SUGGEST THAT BETAHISTINE ATTENUATES ABNORMAL ADIPOGENESIS AND LIPOGENESIS TRIGGERED BY OLANZAPINE THROUGH MODULATING HEPATIC HISTONE METHYLATION, AND THUS INHIBITING THE PPARGAMMA PATHWAY-MEDIATED LIPID STORAGE, WHILE AT THE SAME TIME PROMOTING CP1A-MEDIATED FATTY ACID OXIDATION. 2023 6 1818 35 EFFECTS OF CHRONIC METHAMPHETAMINE EXPOSURE ON REWARDING BEHAVIOR AND NEURODEGENERATION MARKERS IN ADULT MICE. RECREATIONAL AND MEDICAL USE OF STIMULANTS AMONG YOUNG ADULTS HAVE GAINED POPULARITY IN THE UNITED STATES OVER THE LAST DECADE AND THEIR USE MAY INCREASE VULNERABILITY TO BRAIN BIOCHEMICAL CHANGES AND ADDICTIVE BEHAVIORS. THE LONG-TERM EFFECTS OF CHRONIC STIMULANT EXPOSURE IN LATER ADULTHOOD HAVE NOT BEEN FULLY ELUCIDATED.OUR STUDY INVESTIGATED WHETHER CHRONIC EXPOSURE TO METHAMPHETAMINE (METH), AT A DOSE DESIGNED TO EMULATE HUMAN THERAPEUTIC DOSING FOR ADHD, WOULD PROMOTE BIOCHEMICAL ALTERATIONS AND AFFECT SENSITIVITY TO THE REWARDING EFFECTS OF SUBSEQUENT METH DOSING.GROUPS OF 3.5-MONTH-OLD MALE AND FEMALE C57BL/6J MICE WERE ADMINISTERED NON-CONTINGENT INTRAPERITONEAL INJECTIONS OF EITHER SALINE OR METH (1.4 MG/KG) TWICE A DAY FOR 1 MONTH (5 DAYS/WEEK). METH (0.5 MG/KG)-INDUCED CONDITIONED PLACE PREFERENCE (CPP) WAS TESTED IN MICE TO DETERMINE THE EFFECTS OF PREVIOUS METH EXPOSURE ON REWARD-RELATED BEHAVIOR. MICE WERE RANDOMLY ASSIGNED TO EXPERIMENT I (MALES AND FEMALES) OR EXPERIMENT II (FEMALES ONLY) IN WHICH CPP TESTING WAS RESPECTIVELY PERFORMED EITHER 0.5 OR 5 MONTHS AFTER THE END OF METH INJECTIONS, AT ~5 OR 10 MONTHS OLD RESPECTIVELY. THE MIDBRAIN AND STRIATUM, REGIONS INVOLVED IN REWARD CIRCUIT, WERE ASSESSED FOR MARKERS ASSOCIATED WITH NEUROTOXICITY, DOPAMINERGIC FUNCTION, NEUROINFLAMMATION AND EPIGENETIC CHANGES AFTER BEHAVIORAL TESTING.PREVIOUS EXPOSURE TO CHRONIC METH DID NOT HAVE SIGNIFICANT SHORT-TERM EFFECTS ON CPP RESPONSE BUT LED TO A DECREASED CPP RESPONSE IN 10-MONTH-OLD FEMALES. PREVIOUS EXPOSURE TO METH INDUCED SOME SHORT-TERM CHANGES TO BIOCHEMICAL MARKERS MEASURED IN A BRAIN REGION AND SEX-DEPENDENT MANNER, WHILE LONG-TERM CHANGES WERE ONLY OBSERVED WITH GFAP AND KDM5C.IN CONCLUSION, OUR DATA SUGGEST SEX- AND POST-EXPOSURE DURATION-DEPENDENT OUTCOMES AND WARRANT FURTHER EXPLORATION OF THE LONG-TERM NEUROBEHAVIORAL CONSEQUENCES OF PSYCHOSTIMULANT USE IN BOTH SEXES. 2023 7 3443 29 HYPERMETHYLATION IN THE PROMOTER REGION OF THE ADRA1A GENE IS ASSOCIATED WITH OPIOID USE DISORDER IN HAN CHINESE. OPIOID USE DISORDER IS A CHRONIC BRAIN DISEASE INFLUENCED BY GENETIC AND EPIGENETIC FACTORS, ACCOUNTING FOR APPROXIMATELY 50% OF THE LIABILITY. ADRENERGIC SIGNALING IS INVOLVED IN OPIOID USE DISORDER. TO DEMONSTRATE THE ASSOCIATIONS BETWEEN METHYLATION ALTERATIONS IN THE ALPHA-1-ADRENERGIC RECEPTOR (ADRA1A) GENE AND OPIOID USE DISORDER, IN THE PRESENT STUDY, WE FIRST EXAMINED AND COMPARED THE METHYLATION LEVELS OF 97 CPG SITES IN THE PROMOTER REGION OF THE ADRA1A GENE IN THE PERIPHERAL BLOOD IN 120 PATIENTS WITH HEROIN USE DISORDER AND 111 HEALTHY CONTROLS. CORRELATIONS BETWEEN METHYLATION LEVELS AND DURATION OF HEROIN/METHADONE USE WERE THEN ANALYZED. FINALLY, THE PREDICTED BINDING TRANSCRIPTION FACTORS (TFS) AND THEIR TARGET SEQUENCES IN THE PROMOTER REGION OF THE ADRA1A GENE, WHICH INCLUDE THE SELECTED CPG SITES, WERE SCREENED IN THE JASPAR DATABASE. OUR RESULTS DEMONSTRATED THAT HYPERMETHYLATION IN THE PROMOTER REGION OF THE ADRA1A GENE IN THE BLOOD WAS ASSOCIATED WITH OPIOID USE DISORDER. CORRELATIONS BETWEEN METHYLATION LEVELS OF SEVERAL CPG SITES AND DURATION OF HEROIN/METHADONE USE WERE OBSERVED. TFS TFAP2A AND RUNX1 WERE PREDICTED TO BIND TO THE TARGET SEQUENCES, WHICH INCLUDE THE CPG SITES SELECTED IN THE CURRENT STUDY, IN THE PROMOTER REGION OF THE ADRA1A GENE. OUR FINDINGS FURTHER EXTEND THE ASSOCIATIONS BETWEEN METHYLATION ALTERATIONS IN THE ADRA1A GENE AND OPIOID USE DISORDER POTENTIALLY THROUGH MECHANISMS OF GENE EXPRESSION REGULATIONS IN THE ADRA1A GENE. 2022 8 3331 41 HISTONE DEACETYLASE INHIBITOR SUBERANILOHYDROXAMIC ACID TREATMENT REVERSES HYPOSENSITIVITY TO GAMMA-AMINOBUTYRIC ACID IN THE VENTRAL TEGMENTAL AREA DURING ETHANOL WITHDRAWAL. BACKGROUND: THE VENTRAL TEGMENTAL AREA (VTA) IS IMPORTANT FOR ALCOHOL-RELATED REWARD AND REINFORCEMENT. MOUSE VTA NEURONS ARE HYPOSENSITIVE TO GAMMA-AMINOBUTYRIC ACID (GABA) DURING ETHANOL (ETOH) WITHDRAWAL, AND GABA RESPONSIVENESS IS NORMALIZED BY IN VITRO TREATMENT WITH HISTONE DEACETYLASE INHIBITORS (HDACI). THE PRESENT STUDY EXAMINED THE EFFECT OF A SYSTEMICALLY ADMINISTERED HDACI, SUBERANILOHYDROXAMIC ACID (SAHA) ON GABA SENSITIVITY, AND RELATED MOLECULAR CHANGES IN VTA NEURONS DURING WITHDRAWAL AFTER CHRONIC ETOH INTAKE IN RATS. METHODS: SPRAGUE DAWLEY MALE ADULT RATS WERE FED WITH LIEBER-DECARLI DIET (9% ETOH OR CONTROL DIET) FOR 16 DAYS. EXPERIMENTAL GROUPS INCLUDED CONTROL DIET-FED AND ETOH DIET-FED (0- OR 24-HOUR WITHDRAWAL) RATS TREATED WITH EITHER SAHA OR VEHICLE INJECTION. SINGLE-UNIT RECORDINGS WERE USED TO MEASURE THE RESPONSE OF VTA NEURONS TO GABA. IMMUNOHISTOCHEMISTRY WAS PERFORMED TO EXAMINE LEVELS OF HDAC2, ACETYLATED HISTONE H3 LYSINE 9 (ACH3K9), AND GABA(A) RECEPTOR ALPHA1 AND ALPHA5 SUBUNITS IN THE VTA; QUANTITATIVE POLYMERASE CHAIN REACTION WAS PERFORMED TO EXAMINE THE MRNA LEVELS OF HDAC2 AND GABA(A) RECEPTOR SUBUNITS. RESULTS: VTA NEURONS FROM THE WITHDRAWAL GROUP EXHIBITED GABA HYPOSENSITIVITY. IN VIVO SAHA TREATMENT 2 HOURS BEFORE SACRIFICE NORMALIZED THE SENSITIVITY OF VTA NEURONS TO GABA. ETOH WITHDRAWAL WAS ASSOCIATED WITH INCREASED HDAC2 AND DECREASED ACH3K9 PROTEIN LEVELS; SAHA TREATMENT NORMALIZED ACH3K9 LEVELS. INTERESTINGLY, NO SIGNIFICANT CHANGE WAS OBSERVED IN THE MRNA LEVELS OF HDAC2. THE MRNA LEVELS, BUT NOT PROTEIN LEVELS, OF GABA(A) RECEPTOR ALPHA1 AND ALPHA5 SUBUNITS WERE INCREASED DURING WITHDRAWAL. CONCLUSIONS: WITHDRAWAL FROM CHRONIC ETOH EXPOSURE RESULTS IN A DECREASE IN GABA-MEDIATED INHIBITION, AND THIS GABA HYPOSENSITIVITY IS NORMALIZED BY IN VIVO SAHA TREATMENT. DISRUPTION OF SIGNALING IN THE VTA PRODUCED BY ALTERATION OF GABA NEUROTRANSMISSION COULD BE 1 NEUROADAPTIVE PHYSIOLOGICAL PROCESS LEADING TO CRAVING AND RELAPSE. THESE RESULTS SUGGEST THAT HDACI PHARMACOTHERAPY WITH AGENTS LIKE SAHA MIGHT BE AN EFFECTIVE TREATMENT FOR ALCOHOLISM. 2018 9 3201 38 HDAC2 IN PRIMARY SENSORY NEURONS CONSTITUTIVELY RESTRAINS CHRONIC PAIN BY REPRESSING ALPHA2DELTA-1 EXPRESSION AND ASSOCIATED NMDA RECEPTOR ACTIVITY. ALPHA2DELTA-1 (ENCODED BY THE CACNA2D1 GENE) IS A NEWLY DISCOVERED NMDA RECEPTOR-INTERACTING PROTEIN AND IS THE THERAPEUTIC TARGET OF GABAPENTINOIDS (E.G., GABAPENTIN AND PREGABALIN) FREQUENTLY USED FOR TREATING PATIENTS WITH NEUROPATHIC PAIN. NERVE INJURY CAUSES SUSTAINED ALPHA2DELTA-1 UPREGULATION IN THE DORSAL ROOT GANGLION (DRG), WHICH PROMOTES NMDA RECEPTOR SYNAPTIC TRAFFICKING AND ACTIVATION IN THE SPINAL DORSAL HORN, A HALLMARK OF CHRONIC NEUROPATHIC PAIN. HOWEVER, LITTLE IS KNOWN ABOUT HOW NERVE INJURY INITIATES AND MAINTAINS THE HIGH EXPRESSION LEVEL OF ALPHA2DELTA-1 TO SUSTAIN CHRONIC PAIN. HERE, WE SHOW THAT NERVE INJURY CAUSED HISTONE HYPERACETYLATION AND DIMINISHED ENRICHMENT OF HISTONE DEACETYLASE-2 (HDAC2), BUT NOT HDAC3, AT THE CACNA2D1 PROMOTER IN THE DRG. STRIKINGLY, HDAC2 KNOCKDOWN OR CONDITIONAL KNOCKOUT IN DRG NEURONS IN MALE AND FEMALE MICE CONSISTENTLY INDUCED LONG-LASTING MECHANICAL PAIN HYPERSENSITIVITY, WHICH WAS READILY REVERSED BY BLOCKING NMDA RECEPTORS, INHIBITING ALPHA2DELTA-1 WITH GABAPENTIN OR DISRUPTING THE ALPHA2DELTA-1-NMDA RECEPTOR INTERACTION AT THE SPINAL CORD LEVEL. HDAC2 DELETION IN DRG NEURONS INCREASED HISTONE ACETYLATION LEVELS AT THE CACNA2D1 PROMOTER, UPREGULATED ALPHA2DELTA-1 IN THE DRG, AND POTENTIATED ALPHA2DELTA-1-DEPENDENT NMDA RECEPTOR ACTIVITY AT PRIMARY AFFERENT CENTRAL TERMINALS IN THE SPINAL DORSAL HORN. CORRESPONDINGLY, HDAC2 KNOCKDOWN-INDUCED PAIN HYPERSENSITIVITY WAS BLUNTED IN CACNA2D1 KNOCKOUT MICE. THUS, OUR FINDINGS REVEAL THAT HDAC2 FUNCTIONS AS A PIVOTAL TRANSCRIPTIONAL REPRESSOR OF NEUROPATHIC PAIN VIA CONSTITUTIVELY SUPPRESSING ALPHA2DELTA-1 EXPRESSION AND ENSUING PRESYNAPTIC NMDA RECEPTOR ACTIVITY IN THE SPINAL CORD. HDAC2 ENRICHMENT LEVELS AT THE CACNA2D1 PROMOTER IN DRG NEURONS CONSTITUTE A UNIQUE EPIGENETIC MECHANISM THAT GOVERNS ACUTE-TO-CHRONIC PAIN TRANSITION.SIGNIFICANCE STATEMENT EXCESS ALPHA2DELTA-1 PROTEINS PRODUCED AFTER NERVE INJURY DIRECTLY INTERACT WITH GLUTAMATE NMDA RECEPTORS TO POTENTIATE SYNAPTIC NMDA RECEPTOR ACTIVITY IN THE SPINAL CORD, A PROMINENT MECHANISM OF NERVE PAIN. BECAUSE ALPHA2DELTA-1 UPREGULATION AFTER NERVE INJURY IS LONG LASTING, GABAPENTINOIDS RELIEVE PAIN SYMPTOMS ONLY TEMPORARILY. OUR STUDY DEMONSTRATES FOR THE FIRST TIME THE UNEXPECTED ROLE OF INTRINSIC HDAC2 ACTIVITY AT THE ALPHA2DELTA-1 GENE PROMOTER IN LIMITING ALPHA2DELTA-1 GENE TRANSCRIPTION, NMDA RECEPTOR-DEPENDENT SYNAPTIC PLASTICITY, AND CHRONIC PAIN DEVELOPMENT AFTER NERVE INJURY. THESE FINDINGS CHALLENGE THE PREVAILING VIEW ABOUT THE ROLE OF GENERAL HDAC ACTIVITY IN PROMOTING CHRONIC PAIN. RESTORING THE REPRESSIVE HDAC2 FUNCTION AND/OR REDUCING HISTONE ACETYLATION AT THE ALPHA2DELTA-1 GENE PROMOTER IN PRIMARY SENSORY NEURONS COULD LEAD TO LONG-LASTING RELIEF OF NERVE PAIN. 2022 10 2482 32 EPIGENETIC UPREGULATION OF METABOTROPIC GLUTAMATE RECEPTOR 2 IN THE SPINAL CORD ATTENUATES OESTROGEN-INDUCED VISCERAL HYPERSENSITIVITY. OBJECTIVE: EPIGENETIC MECHANISMS ARE POTENTIAL TARGETS TO RELIEVE SOMATIC PAIN. HOWEVER, LITTLE IS KNOWN WHETHER EPIGENETIC REGULATION INTERFERES WITH VISCERAL PAIN. PREVIOUS STUDIES SHOW THAT OESTROGEN FACILITATES VISCERAL PAIN. THIS STUDY AIMED TO DETERMINE WHETHER HISTONE HYPERACETYLATION IN THE SPINAL CORD COULD ATTENUATE OESTROGEN-FACILITATED VISCERAL PAIN. DESIGN: THE EFFECT OF THE HISTONE DEACETYLASE INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) ON THE MAGNITUDE OF THE VISCEROMOTOR RESPONSE (VMR) TO COLORECTAL DISTENTION WAS EXAMINED IN OVARIECTOMISED RATS WITH/WITHOUT OESTROGEN REPLACEMENT. AN ADDITIONAL INTERACTION WITH THE METABOTROPIC GLUTAMATE RECEPTOR 2/3 (MGLUR2/3) ANTAGONIST LY341495 WAS TESTED. THE LEVELS OF ACETYLATED HISTONE AND MGLUR2 MRNA AND PROTEIN WERE ANALYSED. THE BINDING OF ACETYLATED H3 AND OESTROGEN RECEPTOR ALPHA (ERALPHA) TO THE GRM2 PROMOTER WAS MEASURED BY CHROMATIN IMMUNOPRECIPITATION COUPLED WITH QPCR. RESULTS: IN OVARIECTOMISED RATS, 17BETA-ESTRADIOL (E2), BUT NOT SAFFLOWER OIL, INCREASED THE MAGNITUDE OF THE VMR TO COLORECTAL DISTENTION. SAHA ATTENUATED THE E2-FACILITATED VMR, BUT HAD NO EFFECT IN SAFFLOWER OIL-TREATED RATS. SUBSEQUENT SPINAL ADMINISTRATION OF LY341495 REVERSED THE ANTINOCICEPTIVE EFFECT OF SAHA IN E2 RATS. IN ADDITION, SAHA INCREASED MGLUR2 MRNA AND PROTEIN IN THE SPINAL DORSAL HORN FOLLOWING E2, BUT NOT VEHICLE, TREATMENT. IN CONTRAST, NEITHER E2 NOR SAHA ALONE ALTERED MGLUR2 MRNA. SAHA INCREASED BINDING OF H3K9AC AND ERALPHA TO THE SAME REGIONS OF THE GRM2 PROMOTER IN E2-SAHA-TREATED ANIMALS. CONCLUSIONS: HISTONE HYPERACETYLATION IN THE SPINAL CORD ATTENUATES THE PRONOCICEPTIVE EFFECTS OF OESTROGEN ON VISCERAL SENSITIVITY, SUGGESTING THAT EPIGENETIC REGULATION MAY BE A POTENTIAL APPROACH TO RELIEVE VISCERAL PAIN. 2015 11 400 36 ANALGESIA INDUCED BY THE EPIGENETIC DRUG, L-ACETYLCARNITINE, OUTLASTS THE END OF TREATMENT IN MOUSE MODELS OF CHRONIC INFLAMMATORY AND NEUROPATHIC PAIN. BACKGROUND L-ACETYLCARNITINE, A DRUG MARKETED FOR THE TREATMENT OF CHRONIC PAIN, CAUSES ANALGESIA BY EPIGENETICALLY UP-REGULATING TYPE-2 METABOTROPIC GLUTAMATE (MGLU2) RECEPTORS IN THE SPINAL CORD. BECAUSE THE EPIGENETIC MECHANISMS ARE TYPICALLY LONG-LASTING, WE HYPOTHESIZED THAT ANALGESIA COULD OUTLAST THE DURATION OF L-ACETYLCARNITINE TREATMENT IN MODELS OF INFLAMMATORY AND NEUROPATHIC PAIN. RESULTS A SEVEN-DAY TREATMENT WITH L-ACETYLCARNITINE (100 MG/KG, ONCE A DAY, I.P.) PRODUCED AN ANTIALLODYNIC EFFECT IN THE COMPLETE FREUND ADJUVANT MOUSE MODEL OF CHRONIC INFLAMMATORY PAIN. L-ACETYLCARNITINE-INDUCED ANALGESIA PERSISTED FOR AT LEAST 14 DAYS AFTER DRUG WITHDRAWAL. IN CONTRAST, THE ANALGESIC EFFECT OF PREGABALIN, AMITRYPTILINE, CEFTRIAXONE, AND N-ACETYLCYSTEINE DISAPPEARED SEVEN DAYS AFTER DRUG WITHDRAWAL. L-ACETYLCARNITINE TREATMENT ENHANCED MGLU2/3 RECEPTOR PROTEIN LEVELS IN THE DORSAL REGION OF THE SPINAL CORD. THIS EFFECT ALSO PERSISTED FOR TWO WEEKS AFTER DRUG WITHDRAWAL AND WAS ASSOCIATED WITH INCREASED LEVELS OF ACETYLATED HISTONE H3 BOUND TO THE GRM2 GENE PROMOTER IN THE DORSAL ROOT GANGLIA. A LONG-LASTING ANALGESIC EFFECT OF L-ACETYLCARNITINE WAS ALSO OBSERVED IN MICE SUBJECTED TO CHRONIC CONSTRICTION INJURY OF THE SCIATIC NERVE. IN THESE ANIMALS, A 14-DAY TREATMENT WITH PREGABALIN, AMITRYPTILINE, TRAMADOL, OR L-ACETYLCARNITINE PRODUCED A SIGNIFICANT ANTIALLODYNIC EFFECT, WITH PREGABALIN DISPLAYING THE GREATEST EFFICACY. IN MICE TREATED WITH PREGABALIN, TRAMADOL OR L-ACETYLCARNITINE THE ANALGESIC EFFECT WAS STILL VISIBLE 15 DAYS AFTER THE END OF DRUG TREATMENT. HOWEVER, ONLY IN MICE TREATED WITH L-ACETYLCARNITINE ANALGESIA PERSISTED 37 DAYS AFTER DRUG WITHDRAWAL. THIS EFFECT WAS ASSOCIATED WITH AN INCREASE IN MGLU2/3 RECEPTOR PROTEIN LEVELS IN THE DORSAL HORNS OF THE SPINAL CORD. CONCLUSIONS OUR FINDINGS SUGGEST THAT L-ACETYLCARNITINE HAS THE UNIQUE PROPERTY TO CAUSE A LONG-LASTING ANALGESIC EFFECT THAT MIGHT REDUCE RELAPSES IN PATIENTS SUFFERING FROM CHRONIC PAIN. 2017 12 2745 32 EXPRESS: HISTONE HYPERACETYLATION MODULATES SPINAL TYPE II METABOTROPIC GLUTAMATE RECEPTOR ALLEVIATING STRESS-INDUCED VISCERAL HYPERSENSITIVITY IN FEMALE RATS. STRESS IS OFTEN A TRIGGER TO EXACERBATE CHRONIC PAIN INCLUDING VISCERAL HYPERSENSITIVITY ASSOCIATED WITH IRRITABLE BOWEL SYNDROME, A FEMALE PREDOMINANT FUNCTIONAL BOWEL DISORDER. EPIGENETIC MECHANISMS THAT MEDIATE STRESS RESPONSES ARE A POTENTIAL TARGET TO INTERFERE WITH VISCERAL PAIN. THE PURPOSE OF THIS STUDY WAS TO EXAMINE THE EFFECT OF A HISTONE DEACETYLASE INHIBITOR, SUBEROYLANILIDE HYDROXAMIC ACID, ON VISCERAL HYPERSENSITIVITY INDUCED BY A SUBCHRONIC STRESSOR IN FEMALE RATS AND TO INVESTIGATE THE INVOLVEMENT OF SPINAL GLUTAMATE RECEPTORS. THREE DAILY SESSIONS OF FORCED SWIM INDUCED VISCERAL HYPERSENSITIVITY. INTRATHECAL SUBEROYLANILIDE HYDROXAMIC ACID PREVENTED OR REVERSED THE STRESS-INDUCED VISCERAL HYPERSENSITIVITY, INCREASED SPINAL HISTONE 3 ACETYLATION AND INCREASED MGLUR2 AND MGLUR3 EXPRESSION. CHROMATIN IMMUNOPRECIPITATION (CHIP) ANALYSIS REVEALED ENRICHMENT OF H3K9AC AND H3K18AC AT SEVERAL PROMOTER GRM2 AND GRM3 REGIONS. THE MGLUR2/3 ANTAGONIST LY341495 REVERSED THE INHIBITORY EFFECT OF SUBEROYLANILIDE HYDROXAMIC ACID ON THE STRESS-INDUCED VISCERAL HYPERSENSITIVITY. IN SURPRISING CONTRAST, STRESS AND/OR SUBEROYLANILIDE HYDROXAMIC ACID HAD NO EFFECT ON SPINAL NMDA RECEPTOR EXPRESSION OR FUNCTION. THESE DATA REVEAL HISTONE MODIFICATION MODULATES MGLUR2/3 EXPRESSION IN THE SPINAL CORD TO ATTENUATE STRESSINDUCED VISCERAL HYPERSENSITIVITY. HDAC INHIBITORS MAY PROVIDE A POTENTIAL APPROACH TO RELIEVE VISCERAL HYPERSENSITIVITY ASSOCIATED WITH IRRITABLE BOWEL SYNDROME. 2016 13 4397 45 MODULATION OF DNA METHYLATION AND GENE EXPRESSION IN RODENT CORTICAL NEUROPLASTICITY PATHWAYS EXERTS RAPID ANTIDEPRESSANT-LIKE EFFECTS. BACKGROUND: STRESS INCREASES DNA METHYLATION, PRIMARILY A SUPPRESSIVE EPIGENETIC MECHANISM CATALYZED BY DNA METHYLTRANSFERASES (DNMT), AND DECREASES THE EXPRESSION OF GENES INVOLVED IN NEURONAL PLASTICITY AND MOOD REGULATION. DESPITE CHRONIC ANTIDEPRESSANT TREATMENT DECREASES STRESS-INDUCED DNA METHYLATION, IT IS NOT KNOWN WHETHER INHIBITION OF DNMT WOULD CONVEY RAPID ANTIDEPRESSANT-LIKE EFFECTS. AIM: THIS WORK TESTED SUCH A HYPOTHESIS AND EVALUATED WHETHER A BEHAVIORAL EFFECT INDUCED BY DNMT INHIBITORS (DNMTI) CORRESPONDS WITH CHANGES IN DNA METHYLATION AND TRANSCRIPT LEVELS IN GENES CONSISTENTLY ASSOCIATED WITH THE NEUROBIOLOGY OF DEPRESSION AND SYNAPTIC PLASTICITY (BDNF, TRKB, 5-HT(1A), NMDA, AND AMPA). METHODS: MALE WISTAR RATS RECEIVED INTRAPERITONEAL (I.P.) INJECTION OF TWO PHARMACOLOGICALLY DIFFERENT DNMTI (5-AZAD 0.2 AND 0.6 MG/KG OR RG108 0.6 MG/KG) OR VEHICLE (1 ML/KG), 1 H OR 7 DAYS BEFORE THE LEARNED HELPLESSNESS TEST (LH). DNA METHYLATION IN TARGET GENES AND THE CORRESPONDENT TRANSCRIPT LEVELS WERE MEASURED IN THE HIPPOCAMPUS (HPC) AND PREFRONTAL CORTEX (PFC) USING MEDIP-QPCR. IN PARALLEL SEPARATE GROUPS, THE ANTIDEPRESSANT-LIKE EFFECT OF 5-AZAD AND RG108 WAS INVESTIGATED IN THE FORCED SWIMMING TEST (FST). THE INVOLVEMENT OF CORTICAL BDNF-TRKB-MTOR PATHWAYS WAS ASSESSED BY INTRA-VENTRAL MEDIAL PFC (VMPFC) INJECTIONS OF RAPAMYCIN (MTOR INHIBITOR), K252A (TRKB RECEPTOR ANTAGONIST), OR VEHICLE (0.2 MUL/SIDE). RESULTS: WE FOUND THAT BOTH 5-AZAD AND RG108 ACUTELY AND 7 DAYS BEFORE THE TEST DECREASED ESCAPE FAILURES IN THE LH. LH STRESS INCREASED DNA METHYLATION AND DECREASED TRANSCRIPT LEVELS OF BDNF IV AND TRKB IN THE PFC, EFFECTS THAT WERE NOT SIGNIFICANTLY ATTENUATED BY RG108 TREATMENT. THE SYSTEMIC ADMINISTRATION OF 5-AZAD (0.2 MG/KG) AND RG108 (0.2 MG/KG) INDUCED AN ANTIDEPRESSANT-LIKE EFFECT IN FST, WHICH WAS, HOWEVER, ATTENUATED BY TRKB AND MTOR INHIBITION INTO THE VMPFC. CONCLUSION: THESE FINDINGS SUGGEST THAT ACUTE INHIBITION OF STRESS-INDUCED DNA METHYLATION PROMOTES RAPID AND SUSTAINED ANTIDEPRESSANT EFFECTS ASSOCIATED WITH INCREASED BDNF-TRKB-MTOR SIGNALING IN THE PFC. 2021 14 742 34 CANNABINOID CB2 RECEPTORS ARE UPREGULATED VIA BIVALENT HISTONE MODIFICATIONS AND CONTROL PRIMARY AFFERENT INPUT TO THE SPINAL CORD IN NEUROPATHIC PAIN. TYPE-2 CANNABINOID RECEPTORS (CB2, ENCODED BY THE CNR2 GENE) ARE MAINLY EXPRESSED IN IMMUNE CELLS, AND CB2 AGONISTS NORMALLY HAVE NO ANALGESIC EFFECT. HOWEVER, NERVE INJURY UPREGULATES CB2 IN THE DORSAL ROOT GANGLION (DRG), FOLLOWING WHICH CB2 STIMULATION REDUCES NEUROPATHIC PAIN. IT IS UNCLEAR HOW NERVE INJURY INCREASES CB2 EXPRESSION OR HOW CB2 ACTIVITY IS TRANSFORMED IN NEUROPATHIC PAIN. IN THIS STUDY, IMMUNOBLOTTING SHOWED THAT SPINAL NERVE LIGATION (SNL) INDUCED A DELAYED AND SUSTAINED INCREASE IN CB2 EXPRESSION IN THE DRG AND DORSAL SPINAL CORD SYNAPTOSOMES. RNASCOPE IN SITU HYBRIDIZATION ALSO SHOWED THAT SNL SUBSTANTIALLY INCREASED CB2 MRNA LEVELS, MOSTLY IN MEDIUM AND LARGE DRG NEURONS. FURTHERMORE, WE FOUND THAT THE SPECIFIC CB2 AGONIST JWH-133 SIGNIFICANTLY INHIBITS THE AMPLITUDE OF DORSAL ROOT-EVOKED GLUTAMATERGIC EXCITATORY POSTSYNAPTIC CURRENTS IN SPINAL DORSAL HORN NEURONS IN SNL RATS, BUT NOT IN SHAM CONTROL RATS; INTRATHECAL INJECTION OF JWH-133 REVERSED PAIN HYPERSENSITIVITY IN SNL RATS, BUT HAD NO EFFECT IN SHAM CONTROL RATS. IN ADDITION, CHROMATIN IMMUNOPRECIPITATION-QPCR ANALYSIS SHOWED THAT SNL INCREASED ENRICHMENT OF TWO ACTIVATING HISTONE MARKS (H3K4ME3 AND H3K9AC) AND DIMINISHED OCCUPANCY OF TWO REPRESSIVE HISTONE MARKS (H3K9ME2 AND H3K27ME3) AT THE CNR2 PROMOTER IN THE DRG. IN CONTRAST, SNL HAD NO EFFECT ON DNA METHYLATION LEVELS AROUND THE CNR2 PROMOTER. OUR FINDINGS SUGGEST THAT PERIPHERAL NERVE INJURY PROMOTES CB2 EXPRESSION IN PRIMARY SENSORY NEURONS VIA EPIGENETIC BIVALENT HISTONE MODIFICATIONS AND THAT CB2 ACTIVATION REDUCES NEUROPATHIC PAIN BY ATTENUATING NOCICEPTIVE TRANSMISSION FROM PRIMARY AFFERENT NERVES TO THE SPINAL CORD. 2022 15 1401 22 DIETARY AND PHARMACOLOGICAL TREATMENT OF ABDOMINAL PAIN IN IBS. THIS REVIEW INTRODUCES THE PRINCIPLES OF VISCERAL SENSATION AND APPRAISES THE CURRENT APPROACHES TO MANAGEMENT OF VISCERAL PAIN IN FUNCTIONAL GI DISEASES, PRINCIPALLY IBS. THESE APPROACHES INCLUDE DIETARY MEASURES INCLUDING FIBRE SUPPLEMENTATION, LOW FERMENTABLE OLIGOSACCHARIDES, DISACCHARIDES, MONOSACCHARIDES AND POLYOLS DIET, AND PHARMACOLOGICAL APPROACHES SUCH AS ANTISPASMODICS, PEPPERMINT OIL, ANTIDEPRESSANTS (TRICYCLIC AGENTS, SELECTIVE SEROTONIN REUPTAKE INHIBITORS), 5-HT(3) RECEPTOR ANTAGONISTS (ALOSETRON, ONDANSETRON, RAMOSETRON), NON-ABSORBED ANTIBIOTIC (RIFAXIMIN), SECRETAGOGUES (LUBIPROSTONE, LINACLOTIDE), MU-OPIOID RECEPTOR (OR) AND KAPPA-OR AGONIST, DELTA-OR ANTAGONIST (ELUXADOLINE), HISTAMINE H1 RECEPTOR ANTAGONIST (EBASTINE), NEUROKININ-2 RECEPTOR ANTAGONIST (IBODUTANT) AND GABAERGIC AGENTS (GABAPENTIN AND PREGABALIN). EFFICACY AND SAFETY ARE DISCUSSED BASED ON PIVOTAL TRIALS OR PUBLISHED SYSTEMATIC REVIEWS AND META-ANALYSIS, EXPRESSING ORS OR RELATIVE RISKS AND THEIR 95% CIS. POTENTIAL NEW APPROACHES MAY BE BASED ON RECENT INSIGHTS ON MUCOSAL EXPRESSION OF GENES, AND MICRORNA AND EPIGENETIC MARKERS IN HUMAN BIOPSIES AND IN ANIMAL MODELS OF VISCERAL HYPERSENSITIVITY.THE OBJECTIVES OF THIS REVIEW ARE TO APPRAISE THE PHYSIOLOGY AND ANATOMY OF GUT SENSATION AND THE EFFICACY IN THE RELIEF OF VISCERAL PAIN (TYPICALLY IN IBS) OF SEVERAL CLASSES OF THERAPIES. THESE INCLUDE FERMENTABLE OLIGOSACCHARIDES, DISACCHARIDES, MONOSACCHARIDES AND POLYOLS (FODMAPS) AND DIFFERENT CLASSES OF MEDICATIONS (BOX 1). BOX 1CLASSES OF PHARMACOLOGICAL AGENTS FOR VISCERAL PAINANTIDEPRESSANTS (TRICYCLIC AGENTS, SELECTIVE SEROTONIN REUPTAKE INHIBITORS)PEPPERMINT OIL5-HT(3) RECEPTOR ANTAGONISTS (ALOSETRON, ONDANSETRON, RAMOSETRON)NON-ABSORBED ANTIBIOTIC (RIFAXIMIN)SECRETAGOGUES (LUBIPROSTONE, LINACLOTIDE)MU-OPIOID RECEPTOR (OR) AND KAPPA-OR AGONIST AND DELTA-OR ANTAGONIST (ELUXADOLINE)HISTAMINE H1 RECEPTOR ANTAGONIST (EBASTINE)NEUROKININ-2 RECEPTOR ANTAGONIST (IBODUTANT)GABAERGIC AGENTS (GABAPENTIN AND PREGABALIN). 2017 16 5657 34 SEX-DEPENDENT PRONOCICEPTIVE ROLE OF SPINAL ALPHA(5) -GABA(A) RECEPTOR AND ITS EPIGENETIC REGULATION IN NEUROPATHIC RODENTS. EXTRASYNAPTIC ALPHA(5) -SUBUNIT CONTAINING GABA(A) (ALPHA(5) -GABA(A) ) RECEPTORS PARTICIPATE IN CHRONIC PAIN. PREVIOUSLY, WE REPORTED A SEX DIFFERENCE IN THE ACTION OF ALPHA(5) -GABA(A) RECEPTORS IN DYSFUNCTIONAL PAIN. HOWEVER, THE UNDERLYING MECHANISMS REMAIN UNKNOWN. THE AIM OF THIS STUDY WAS TO EXAMINE THIS SEXUAL DIMORPHISM IN NEUROPATHIC RODENTS AND THE MECHANISMS INVOLVED. FEMALE AND MALE WISTAR RATS OR ICR MICE WERE SUBJECTED TO NERVE INJURY FOLLOWED BY ALPHA(5) -GABA(A) RECEPTOR INVERSE AGONIST INTRATHECAL ADMINISTRATION, L-655,708. THE DRUG PRODUCED AN ANTIALLODYNIC EFFECT IN NERVE-INJURED FEMALE RATS AND MICE, AND A LOWER EFFECT IN MALES. WE HYPOTHESIZED THAT CHANGES IN ALPHA(5) -GABA(A) RECEPTOR, PROBABLY INFLUENCED BY HORMONAL AND EPIGENETIC STATUS, MIGHT UNDERLIE THIS SEX DIFFERENCE. THUS, WE PERFORMED QPCR AND WESTERN BLOT. NERVE INJURY INCREASED ALPHA(5) -GABA(A) MRNA AND PROTEIN IN FEMALE DORSAL ROOT GANGLIA (DRG) AND DECREASED THEM IN DRG AND SPINAL CORD OF MALES. TO INVESTIGATE THE HORMONAL INFLUENCE OVER ALPHA(5) -GABA(A) RECEPTOR ACTIONS, WE PERFORMED NERVE INJURY TO OVARIECTOMIZED RATS AND RECONSTITUTED THEM WITH 17BETA-ESTRADIOL (E2). OVARIECTOMY ABROGATED L-655,708 ANTIALLODYNIC EFFECT AND E2 RESTORED IT. OVARIECTOMY DECREASED ALPHA(5) -GABA(A) RECEPTOR AND ESTROGEN RECEPTOR ALPHA PROTEIN IN DRG OF NEUROPATHIC FEMALE RATS, WHILE E2 ENHANCED THEM. SINCE DNA METHYLATION MIGHT CONTRIBUTE TO ALPHA(5) -GABA(A) RECEPTOR DOWN-REGULATION IN MALES, WE EXAMINED CPG ISLAND DNA METHYLATION OF ALPHA(5) -GABA(A) RECEPTOR CODING GENE THROUGH PYROSEQUENCING. NERVE INJURY INCREASED METHYLATION IN MALE, BUT NOT FEMALE RATS. PHARMACOLOGICAL INHIBITION OF DNA METHYLTRANSFERASES INCREASED ALPHA(5) -GABA(A) RECEPTOR AND ENABLED L-655,708 ANTINOCICEPTIVE EFFECT IN MALE RATS. THESE RESULTS SUGGEST THAT ALPHA(5) -GABA(A) RECEPTOR IS A SUITABLE TARGET TO TREAT CHRONIC PAIN IN FEMALES. 2021 17 69 34 A MEDIAL PREFRONTAL CORTEX-NUCLEUS ACUMENS CORTICOTROPIN-RELEASING FACTOR CIRCUITRY FOR NEUROPATHIC PAIN-INCREASED SUSCEPTIBILITY TO OPIOID REWARD. RECENT STUDIES HAVE SHOWN THAT PERSISTENT PAIN FACILITATES THE RESPONSE TO MORPHINE REWARD. HOWEVER, THE CIRCUIT MECHANISM UNDERLYING THIS PROCESS REMAINS AMBIGUOUS. IN THIS STUDY, USING CHRONIC CONSTRICTION INJURY (CCI) OF THE SCIATIC NERVE IN MICE, WE FOUND THAT PERSISTENT NEUROPATHIC PAIN REDUCED THE MINIMUM NUMBER OF MORPHINE CONDITIONING SESSIONS REQUIRED TO INDUCE CONDITIONED PLACE PREFERENCE (CPP) BEHAVIOR. THIS DOSE OF MORPHINE HAD NO EFFECT ON THE PAIN THRESHOLD. IN THE MEDIAL PREFRONTAL CORTEX (MPFC), WHICH IS INVOLVED IN BOTH PAIN AND EMOTION PROCESSING, CORTICOTROPIN-RELEASING FACTOR (CRF) EXPRESSING NEURONAL ACTIVITY WAS INCREASED IN CCI MICE. CHEMOGENETIC INHIBITION OF MPFC CRF NEURONS REVERSED CCI-INDUCED MORPHINE CPP FACILITATION. FURTHERMORE, THE NUCLEUS ACUMENS (NAC) RECEIVED MPFC CRF FUNCTIONAL PROJECTIONS THAT EXERTED EXCITATORY EFFECTS ON NAC NEURONS. OPTOGENETIC INHIBITION OF MPCF NEURONAL TERMINALS OR LOCAL INFUSION OF THE CRF RECEPTOR 1 (CRFR1) ANTAGONIST IN THE NAC RESTORED THE EFFECTS OF NEUROPATHIC PAIN ON MORPHINE-INDUCED CPP BEHAVIOR, BUT NOT IN NORMAL MICE. ON A MOLECULAR LEVEL, IN CCI MICE, CRFR1 PROTEIN EXPRESSION WAS INCREASED IN THE NAC BY A HISTONE DIMETHYLTRANSFERASE G9A-MEDIATED EPIGENETIC MECHANISM. LOCAL G9A KNOCKDOWN INCREASED THE EXPRESSION OF CRFR1 AND MIMICKED CCI-INDUCED HYPERSENSITIVITY TO ACQUIRING MORPHINE CPP. TAKEN TOGETHER, THESE FINDINGS DEMONSTRATE A PREVIOUSLY UNKNOWN AND SPECIFIC MPFC CRF ENGAGEMENT OF NAC NEURONAL CIRCUITS, THE SENSITIZATION OF WHICH FACILITATES BEHAVIORAL RESPONSES TO MORPHINE REWARD IN NEUROPATHIC PAIN STATES VIA CRFR1S. 2018 18 6612 29 ULTRA-LOW-DOSE NALOXONE ENHANCES THE ANTINOCICEPTIVE EFFECT OF MORPHINE IN PTX-TREATED RATS: REGULATION ON GLOBAL HISTONE METHYLATION. OBJECTIVE: EPIGENETIC REPROGRAMMING MAY HAVE A POSSIBLE ROLE IN NEUROPATHIC PAIN DEVELOPMENT; THE PRESENT STUDY EXAMINED THE GLOBAL PATTERNS OF LYSINE HISTONE MODIFICATION. IN THIS SERIAL STUDY WE ANALYZED THE LEVELS OF HISTONE 3 LYSINE 4 MONOMETHYLATION, HISTONE 3 LYSINE 4 DIMETHYLATION, AND HISTONE 3 LYSINE 9 TRIMETHYLATION IN PERTUSSIS TOXIN (PTX)-INDUCED THERMAL HYPERALGESIC RAT SPINAL CORDS. METHODS: MALE WISTAR RATS IMPLANTED WITH AN INTRATHECAL CATHETER RECEIVED A SINGLE INTRATHECAL PTX (1 MUG IN 5 MUL SALINE) INJECTION. FOUR DAYS LATER, THEY WERE RANDOMLY ASSIGNED TO RECEIVE EITHER A SINGLE INJECTION OF SALINE, OR ULTRA-LOW-DOSE NALOXONE (15 NG IN 5 MUL SALINE), FOLLOWED BY MORPHINE (10 MUG IN 5 MUL SALINE) INJECTION 30 MINUTES LATER. RESULTS: THE RESULTS SHOWED THAT PTX INJECTION INDUCED THERMAL HYPERALGESIA AND SIGNIFICANT INCREASE OF GLOBAL HISTONE METHYLATION IN THE SPINAL CORDS. INTRATHECAL MORPHINE ALONE DID NOT AFFECT THE THERMAL HYPERALGESIA AND GLOBAL HISTONE METHYLATION. IN CONTRAST, INTRATHECAL ADMINISTRATION OF ULTRA-LOW-DOSE NALOXONE PLUS MORPHINE SIGNIFICANTLY ATTENUATED THE PTX-INDUCED THERMAL HYPERALGESIA AND DOWN-REGULATED THE GLOBAL HISTONE METHYLATION. CONCLUSION: THE RESULTS SUGGEST THAT ULTRA-LOW-DOSE NALOXONE MIGHT BE CLINICAL VALUABLE FOR NEUROPATHIC PAIN MANAGEMENT VIA REGULATING GLOBAL HISTONE MODIFICATION. 2012 19 6525 39 TRANSCRIPTIONAL AND EPIGENETIC SUBSTRATES OF METHAMPHETAMINE ADDICTION AND WITHDRAWAL: EVIDENCE FROM A LONG-ACCESS SELF-ADMINISTRATION MODEL IN THE RAT. METHAMPHETAMINE USE DISORDER IS A CHRONIC NEUROPSYCHIATRIC DISORDER CHARACTERIZED BY RECURRENT BINGE EPISODES, INTERVALS OF ABSTINENCE, AND RELAPSES TO DRUG USE. HUMANS ADDICTED TO METHAMPHETAMINE EXPERIENCE VARIOUS DEGREES OF COGNITIVE DEFICITS AND OTHER NEUROLOGICAL ABNORMALITIES THAT COMPLICATE THEIR ACTIVITIES OF DAILY LIVING AND THEIR PARTICIPATION IN TREATMENT PROGRAMS. IMPORTANTLY, MODELS OF METHAMPHETAMINE ADDICTION IN RODENTS HAVE SHOWN THAT ANIMALS WILL READILY LEARN TO GIVE THEMSELVES METHAMPHETAMINE. RATS ALSO ACCELERATE THEIR INTAKE OVER TIME. MICROARRAY STUDIES HAVE ALSO SHOWN THAT METHAMPHETAMINE TAKING IS ASSOCIATED WITH MAJOR TRANSCRIPTIONAL CHANGES IN THE STRIATUM MEASURED WITHIN A SHORT OR LONGER TIME AFTER CESSATION OF DRUG TAKING. AFTER A 2-H WITHDRAWAL TIME, THERE WAS INCREASED EXPRESSION OF GENES THAT PARTICIPATE IN TRANSCRIPTION REGULATION. THESE INCLUDED CYCLIC AMP RESPONSE ELEMENT BINDING (CREB), ETS DOMAIN-CONTAINING PROTEIN (ELK1), AND MEMBERS OF THE FOS FAMILY OF TRANSCRIPTION FACTORS. OTHER GENES OF INTEREST INCLUDE BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF), TYROSINE KINASE RECEPTOR, TYPE 2 (TRKB), AND SYNAPTOPHYSIN. METHAMPHETAMINE-INDUCED TRANSCRIPTION WAS FOUND TO BE REGULATED VIA PHOSPHORYLATED CREB-DEPENDENT EVENTS. AFTER A 30-DAY WITHDRAWAL FROM METHAMPHETAMINE SELF-ADMINISTRATION, HOWEVER, THERE WAS MOSTLY DECREASED EXPRESSION OF TRANSCRIPTION FACTORS INCLUDING JUND. THERE WAS ALSO DOWNREGULATION OF GENES WHOSE PROTEIN PRODUCTS ARE CONSTITUENTS OF CHROMATIN-REMODELING COMPLEXES. ALTOGETHER, THESE GENOME-WIDE RESULTS SHOW THAT METHAMPHETAMINE ABUSE MIGHT BE ASSOCIATED WITH ALTERED REGULATION OF A DIVERSITY OF GENE NETWORKS THAT IMPACT CELLULAR AND SYNAPTIC FUNCTIONS. THESE TRANSCRIPTIONAL CHANGES MIGHT SERVE AS TRIGGERS FOR THE NEUROPSYCHIATRIC PRESENTATIONS OF HUMANS WHO ABUSE THIS DRUG. BETTER UNDERSTANDING OF THE WAY THAT GENE PRODUCTS INTERACT TO CAUSE METHAMPHETAMINE ADDICTION WILL HELP TO DEVELOP BETTER PHARMACOLOGICAL TREATMENT OF METHAMPHETAMINE ADDICTS. 2015 20 4860 28 OREXIN SIGNALING MEDIATES THE ANTIDEPRESSANT-LIKE EFFECT OF CALORIE RESTRICTION. DURING PERIODS OF REDUCED FOOD AVAILABILITY, ANIMALS MUST RESPOND WITH BEHAVIORAL ADAPTATIONS THAT PROMOTE SURVIVAL. DESPITE THE FACT THAT MANY PSYCHIATRIC SYNDROMES INCLUDE DISORDERED EATING PATTERNS AS A COMPONENT OF THE ILLNESS, LITTLE IS KNOWN ABOUT THE NEUROBIOLOGY UNDERLYING BEHAVIORAL CHANGES INDUCED BY SHORT-TERM CALORIE RESTRICTION. PRESENTLY, WE DEMONSTRATE THAT 10 D OF CALORIE RESTRICTION, CORRESPONDING TO A 20-25% WEIGHT LOSS, CAUSES A MARKED ANTIDEPRESSANT-LIKE RESPONSE IN TWO RODENT MODELS OF DEPRESSION AND THAT THIS RESPONSE IS DEPENDENT ON THE HYPOTHALAMIC NEUROPEPTIDE OREXIN (HYPOCRETIN). WILD-TYPE MICE, BUT NOT MICE LACKING OREXIN, SHOW LONGER LATENCY TO IMMOBILITY AND LESS TOTAL IMMOBILITY IN THE FORCED SWIM TEST AFTER CALORIE RESTRICTION. IN THE SOCIAL DEFEAT MODEL OF CHRONIC STRESS, CALORIE RESTRICTION REVERSES THE BEHAVIORAL DEFICITS SEEN IN WILD-TYPE MICE BUT NOT IN OREXIN KNOCK-OUT MICE. ADDITIONALLY, CHRONIC SOCIAL DEFEAT STRESS INDUCES A PROLONGED REDUCTION IN THE EXPRESSION OF PREPRO-OREXIN MRNA VIA EPIGENETIC MODIFICATION OF THE OREXIN GENE PROMOTER, WHEREAS CALORIE RESTRICTION ENHANCES THE ACTIVATION OF OREXIN CELLS AFTER SOCIAL DEFEAT. TOGETHER, THESE DATA INDICATE THAT OREXIN PLAYS AN ESSENTIAL ROLE IN MEDIATING REDUCED DEPRESSION-LIKE SYMPTOMS INDUCED BY CALORIE RESTRICTION. 2008