1 449 117 APOCYNIN PREVENTS ANXIETY-LIKE BEHAVIOR AND HISTONE DEACETYLASES OVEREXPRESSION INDUCED BY SUB-CHRONIC STRESS IN MICE. ANXIETY DISORDERS ARE COMMON MENTAL HEALTH DISEASES AFFECTING UP TO 7% OF PEOPLE AROUND THE WORLD. STRESS IS CONSIDERED ONE OF THE MAJOR ENVIRONMENTAL RISK FACTORS TO PROMOTE ANXIETY DISORDERS THROUGH MECHANISMS INVOLVING EPIGENETIC CHANGES. MOREOVER, ALTERATION IN REDOX BALANCE AND INCREASED REACTIVE OXYGEN SPECIES (ROS) PRODUCTION HAVE BEEN DETECTED IN ANXIETY PATIENTS AND IN STRESSED-ANIMAL MODELS OF ANXIETY. HERE WE TESTED IF THE ADMINISTRATION OF APOCYNIN, A NATURAL ORIGIN ANTIOXIDANT, MAY PREVENT THE ANXIETY-LIKE PHENOTYPE AND REDUCTION OF HISTONE ACETYLATION INDUCED BY A SUBCHRONIC FORCED SWIMMING STRESS (FSS) PARADIGM. WE FOUND THAT APOCYNIN PREVENTED THE ENHANCED LATENCY TIME IN THE NOVELTY-SUPPRESSED FEEDING TEST, AND THE PRODUCTION OF MALONDIALDEHYDE INDUCED BY FSS. MOREOVER, APOCYNIN WAS ABLE TO BLOCK THE UPREGULATION OF P47PHOX, A KEY SUBUNIT OF THE NADPH OXIDASE COMPLEX. FINALLY, APOCYNIN PREVENTED THE RISE OF HIPPOCAMPAL HDAC1, HDAC4 AND HDAC5, AND THE REDUCTION OF HISTONE-3 ACETYLATION LEVELS PROMOTED BY FSS EXPOSURE. IN CONCLUSION, OUR RESULTS PROVIDE EVIDENCE THAT APOCYNIN REDUCES THE DELETERIOUS EFFECT OF STRESS AND SUGGESTS THAT OXIDATIVE STRESS MAY REGULATE EPIGENETIC MECHANISMS. 2021 2 2745 27 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 3 2116 28 EPIGENETIC HISTONE DEACETYLATION INHIBITION PREVENTS THE DEVELOPMENT AND PERSISTENCE OF TEMPORAL LOBE EPILEPSY. EPILEPSY IS A CHRONIC BRAIN DISEASE CHARACTERIZED BY REPEATED UNPROVOKED SEIZURES. CURRENTLY, NO DRUG THERAPY EXISTS FOR CURING EPILEPSY OR DISEASE MODIFICATION IN PEOPLE AT RISK. DESPITE SEVERAL EMERGING MECHANISMS, THERE HAVE BEEN FEW STUDIES OF EPIGENETIC SIGNALING IN EPILEPTOGENESIS, THE PROCESS WHEREBY A NORMAL BRAIN BECOMES PROGRESSIVELY EPILEPTIC BECAUSE OF PRECIPITATING FACTORS. HERE, WE REPORT A NOVEL ROLE OF HISTONE DEACETYLATION AS A CRITICAL EPIGENETIC MECHANISM IN EPILEPTOGENESIS. EXPERIMENTS WERE CONDUCTED USING THE HISTONE DEACETYLASE (HDAC) INHIBITOR SODIUM BUTYRATE IN THE HIPPOCAMPUS KINDLING MODEL OF TEMPORAL LOBE EPILEPSY (TLE), A CLASSIC MODEL HEAVILY USED TO APPROVE DRUGS FOR TREATMENT OF EPILEPSY. DAILY TREATMENT WITH BUTYRATE SIGNIFICANTLY INHIBITED HDAC ACTIVITY AND RETARDED THE DEVELOPMENT OF LIMBIC EPILEPTOGENESIS WITHOUT AFFECTING AFTER-DISCHARGE SIGNAL. HDAC INHIBITION MARKEDLY IMPAIRED THE PERSISTENCE OF SEIZURE EXPRESSION MANY WEEKS AFTER EPILEPSY DEVELOPMENT. MOREOVER, SUBCHRONIC HDAC INHIBITION FOR 2 WEEKS RESULTED IN A STRIKING RETARDATION OF EPILEPTOGENESIS. HDAC INHIBITION, UNEXPECTEDLY, ALSO SHOWED ERASURE OF THE EPILEPTOGENIC STATE IN EPILEPTIC ANIMALS. FINALLY, BUTYRATE-TREATED ANIMALS EXHIBITED A POWERFUL REDUCTION IN MOSSY FIBER SPROUTING, A MORPHOLOGIC INDEX OF EPILEPTOGENESIS. TOGETHER THESE RESULTS UNDERSCORE THAT HDAC INHIBITION PREVENTS THE DEVELOPMENT OF TLE, INDICATING HDAC'S CRITICAL SIGNALING ROLE IN EPILEPTOGENESIS. THESE FINDINGS, THEREFORE, ENVISAGE A UNIQUE NOVEL THERAPY FOR PREVENTING OR CURING EPILEPSY BY TARGETING THE EPIGENETIC HDAC PATHWAY. 2018 4 1986 24 EPIGENETIC ALTERATIONS MAY REGULATE TEMPORARY REVERSAL OF CD4(+) T CELL ACTIVATION CAUSED BY TRICHLOROETHYLENE EXPOSURE. PREVIOUS STUDIES HAVE SHOWN THAT SHORT-TERM (4 WEEKS) OR CHRONIC (32 WEEKS) EXPOSURE TO TRICHLOROETHYLENE (TCE) IN DRINKING WATER OF FEMALE MRL+/+ MICE GENERATED CD4(+) T CELLS THAT SECRETED INCREASED LEVELS OF INTERFERON (IFN)-GAMMA AND EXPRESSED AN ACTIVATED (CD44(HI)CD62L(LO)) PHENOTYPE. IN CONTRAST, THE CURRENT STUDY OF SUBCHRONIC TCE EXPOSURE SHOWED THAT MIDWAY IN THE DISEASE PROCESS BOTH OF THESE PARAMETERS OF CD4(+) T CELL ACTIVATION WERE REVERSED. THIS PHASE OF THE DISEASE PROCESS MAY REPRESENT AN ATTEMPT BY THE BODY TO COUNTERACT THE INFLAMMATORY EFFECTS OF TCE. THE DECREASE IN CD4(+) T CELL PRODUCTION OF IFN-GAMMA FOLLOWING SUBCHRONIC TCE EXPOSURE COULD NOT BE ATTRIBUTED TO SKEWING TOWARD A TH2 OR TH17 PHENOTYPE OR TO AN INCREASE IN TREG CELLS. INSTEAD, THE SUPPRESSION CORRESPONDED TO ALTERATIONS IN MARKERS USED TO ASSESS DNA METHYLATION, NAMELY INCREASED EXPRESSION OF RETROTRANSPOSONS IAP (INTRACISTERNAL A PARTICLE) AND MUERV (MURINE ENDOGENOUS RETROVIRUS). ALSO OBSERVED WAS AN INCREASE IN THE EXPRESSION OF DNMT1 (DNA METHYLTRANSFERASE-1) AND DECREASED EXPRESSION OF SEVERAL GENES KNOWN TO BE DOWNREGULATED BY DNA METHYLATION, NAMELY IFNG, IL2, AND CDKN1A. CD4(+) T CELLS FROM A SECOND STUDY IN WHICH MRL+/+ MICE WERE TREATED FOR 17 WEEKS WITH TCE SHOWED A SIMILAR INCREASE IN IAP AND DECREASE IN CDKN1A. IN ADDITION, DNA COLLECTED FROM THE CD4(+) T CELLS IN THE SECOND STUDY SHOWED TCE-DECREASED GLOBAL DNA METHYLATION. THUS, THESE RESULTS DESCRIBED THE BIPHASIC NATURE OF TCE-INDUCED ALTERATIONS IN CD4(+) T CELL FUNCTION AND SUGGESTED THAT THESE CHANGES REPRESENTED POTENTIALLY REVERSIBLE ALTERATIONS IN EPIGENETIC PROCESSES. 2012 5 2482 28 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 6 3623 28 IN VIVO COMET ASSAY ON ISOLATED KIDNEY CELLS TO DISTINGUISH GENOTOXIC CARCINOGENS FROM EPIGENETIC CARCINOGENS OR CYTOTOXIC COMPOUNDS. THE OBJECTIVE OF THIS STUDY WAS TO DETERMINE THE ABILITY OF THE ALKALINE IN VIVO COMET ASSAY (PH>13) TO DISTINGUISH GENOTOXIC CARCINOGENS FROM EPIGENETIC CARCINOGENS WHEN PERFORMED ON FRESHLY ISOLATED KIDNEY CELLS AND TO DETERMINE THE POSSIBLE INTERFERENCE OF CYTOTOXICITY BY ASSESSING DNA DAMAGE INDUCED BY RENAL GENOTOXIC, EPIGENETIC OR TOXIC COMPOUNDS AFTER ENZYMATIC ISOLATION OF KIDNEY CELLS FROM OFA SPRAGUE-DAWLEY MALE RATS. THE ABILITY OF THE COMET ASSAY TO DISTINGUISH (1) GENOTOXICITY VERSUS CYTOTOXICITY AND (2) GENOTOXIC VERSUS NON-GENOTOXIC (EPIGENETIC) CARCINOGENS, WAS THUS INVESTIGATED BY STUDYING FIVE KNOWN GENOTOXIC RENAL CARCINOGENS ACTING THROUGH DIVERSE MECHANISMS OF ACTION, I.E. STREPTOZOTOCIN, ARISTOLOCHIC ACIDS, 2-NITROANISOLE, POTASSIUM BROMATE AND CISPLATIN, TWO RODENT RENAL EPIGENETIC CARCINOGENS: D-LIMONENE AND CICLOSPORINE AND TWO NEPHROTOXIC COMPOUNDS: STREPTOMYCIN AND INDOMETHACIN. ANIMALS WERE TREATED ONCE WITH THE TEST COMPOUND BY THE APPROPRIATE ROUTE OF ADMINISTRATION AND GENOTOXIC EFFECTS WERE MEASURED AT THE TWO SAMPLING TIMES OF 3-6 AND 22-26H AFTER TREATMENT. REGARDING THE TISSUE PROCESSING, THE LIMITED BACKGROUND LEVEL OF DNA MIGRATION OBSERVED IN THE NEGATIVE CONTROL GROUPS THROUGHOUT ALL EXPERIMENTS DEMONSTRATED THAT THE ENZYMATIC ISOLATION METHOD IMPLEMENTED IN THE CURRENT STUDY IS APPROPRIATE. ON THE OTHER HAND, STREPTOZOTOCIN, 20MG/KG, USED AS POSITIVE REFERENCE CONTROL CONCURRENTLY TO EACH ASSAY, CAUSED A CLEAR INCREASE IN THE MEAN OLIVE TAIL MOMENT MEDIAN VALUE, WHICH ALLOWS VALIDATING THE CURRENT METHODOLOGY. UNDER THESE EXPERIMENTAL CONDITIONS, THE IN VIVO RODENT COMET ASSAY DEMONSTRATED GOOD SENSITIVITY AND GOOD SPECIFICITY: ALL THE FIVE RENAL GENOTOXIC CARCINOGENS WERE CLEARLY DETECTED IN AT LEAST ONE EXPRESSION PERIOD EITHER DIRECTLY OR INDIRECTLY, AS IN THE CASE OF CISPLATIN: FOR THIS CROSS-LINKING AGENT, THE SIGNIFICANT DECREASE IN DNA MIGRATION OBSERVED UNDER STANDARD ELECTROPHORESIS CONDITIONS WAS CLEARLY AMPLIFIED WHEN THE DURATION OF ELECTROPHORESIS WAS INCREASED UP TO 40MIN. IN CONTRAST, EPIGENETIC AND NEPHROTOXIC COMPOUNDS FAILED TO INDUCE ANY SIGNIFCANT INCREASE IN DNA MIGRATION. IN CONCLUSION, THE IN VIVO RODENT COMET ASSAY PERFORMED ON ISOLATED KIDNEY CELLS COULD BE USED AS A TOOL TO INVESTIGATE THE GENOTOXIC POTENTIAL OF A TEST COMPOUND IF NEOPLASIC/PRENEOPLASIC CHANGES OCCUR AFTER SUBCHRONIC OR CHRONIC TREATMENTS, IN ORDER TO DETERMINE THE ROLE OF GENOTOXICITY IN TUMOR INDUCTION. MOREOVER, THE EPIGENETIC CARCINOGENS AND CYTOTOXIC COMPOUNDS DISPLAYED CLEARLY NEGATIVE RESPONSES IN THIS STUDY. THESE RESULTS ALLOW EXCLUDING A DNA DIRECT-ACTING MECHANISM OF ACTION AND CAN THUS SUGGEST THAT A THRESHOLD EXISTS. THEREFORE, THE CURRENT IN VIVO RODENT COMET ASSAY COULD CONTRIBUTE TO ELUCIDATE AN EPIGENETIC MECHANISM AND THUS, TO UNDERTAKE A RISK ASSESSMENT ASSOCIATED WITH HUMAN USE, DEPENDING ON THE EXPOSURE LEVEL. 2007 7 6175 27 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 8 4123 24 MECHANISMS OF DIMETHYLBENZANTHRACENE-INDUCED IMMUNOTOXICITY. TRADITIONAL METHODS FOR TOXICOLOGICAL ASSESSMENT HAVE IMPLICATED THE IMMUNE SYSTEM AS A FREQUENT TARGET ORGAN OF TOXIC INSULT FOLLOWING CHRONIC EXPOSURE TO CERTAIN ENVIRONMENTAL CHEMICALS, RADIATION OR THERAPEUTIC DRUGS (XENOBIOTICS). IMMUNOTOXICITY IS EXPRESSED AS AUTOIMMUNITY, CHEMICAL HYPERSENSITIVITY OR IMMUNOSUPPRESSION. A TIERED APPROACH FOR CHARACTERIZING CHEMICAL AND DRUG-INDUCED IMMUNOMODULATION HAS BEEN DEVELOPED AND VALIDATED IN LABORATORY ANIMALS. POLYCYCLIC AROMATIC HYDROCARBONS (PAH) HAVE BEEN STUDIED BECAUSE OF THEIR UBIQUITOUS PRESENCE IN THE ENVIRONMENT AND CARCINOGENIC POTENTIAL. SINCE IMMUNOSUPPRESSION INDUCED BY PAH CARCINOGENS HAS BEEN IMPLICATED AS AN EPIGENETIC MECHANISM IN THE OUTGROWTH OF INITIATED CELLS, THIS TIERED APPROACH WAS USED TO CHARACTERIZE THE MECHANISM OF PAH IMMUNOSUPPRESSIVE CAPACITY. PREVIOUSLY, STUDIES IN THIS LABORATORY HAVE DEMONSTRATED THAT SUBCHRONIC EXPOSURE OF B6C3F1 MICE TO PAH CARCINOGENS SUPPRESSES BOTH HUMORAL IMMUNITY (HI) AND CELL-MEDIATED IMMUNITY (CMI), CONCURRENTLY WITH DECREASED RESISTANCE TO TUMOR CHALLENGE. THE POTENT CARCINOGENIC PAH, 7,12-DIMETHYLBENZ[A]ANTHRACENE (DMBA) WAS SUBCHRONICALLY ADMINISTERED SUBCUTANEOUSLY AT 5, 50, OR 100 MICROGRAMS/G OF BODY WEIGHT. NATURAL KILLER (NK) CELL TUMOR CYTOLYSIS, GENERATION OF CYTOTOXIC T-CELLS (CTL), AND LYMPHOPROLIFERATION TO MITOGENS AND ALLOGENEIC SPLENOCYTES IN MIXED LEUKOCYTE CULTURES (MLC) WERE QUANTITATED 3-5 DAYS AFTER EXPOSURE TO ASSESS CMI. MITOGEN AND ALLOANTIGEN-INDUCED PROLIFERATION (MLC) OF SPLENOCYTES WAS SUPPRESSED UP TO 90%. CTL AND NK TUMOR CYTOLYSIS OF RADIOLABELLED TARGET CELLS WERE SIMILARLY DEPRESSED UP TO 88 AND 82%, RESPECTIVELY. IMPAIRMENT OF MLC OR CTL RESPONSES CORRELATED WITH INCREASED SUSCEPTIBILITY TO CHALLENGE WITH PYB6 SARCOMA CELLS. HI WAS MEASURED BY QUANTITATING THE NUMBER OF ANTIBODY (IGM) PLAQUE-FORMING CELLS (PFC) PRODUCED IN RESPONSE TO T-CELL DEPENDENT ANTIGEN CHALLENGE (SHEEP ERYTHROCYTES) AND WAS SIMILARLY SUPPRESSED UP TO 95%. TO UNDERSTAND THE MECHANISM OF PAH-INDUCED IMMUNOTOXICITY, SPLENOCYTES FROM DMBA-EXPOSED MICE WERE SENSITIZED TO ALLOANTIGENS IN THE PRESENCE OF INTERLEUKIN-2 (IL-2) BECAUSE THERE WERE INDICATIONS THAT T-HELPER CELL FUNCTION WAS SUPPRESSED. IN THESE PRELIMINARY STUDIES, CTL SUPPRESSION COULD BE COMPLETELY RESTORED BY THE ADDITION OF THE T-CELL GROWTH SUPPORTING LYMPHOKINE (IL-2) DURING THE INDUCTIVE PHASE OF CTL GENERATION, SUGGESTING THAT DMBA EXPOSURE DIRECTLY OR INDIRECTLY INDUCED DEFICITS IN T-HELPER CELL FUNCTION. 1985 9 2353 28 EPIGENETIC REGULATION OF OPIOID-INDUCED HYPERALGESIA, DEPENDENCE, AND TOLERANCE IN MICE. REPEATED ADMINISTRATION OF OPIOIDS SUCH AS MORPHINE INDUCES PERSISTENT BEHAVIORAL CHANGES INCLUDING OPIOID-INDUCED HYPERALGESIA (OIH), TOLERANCE, AND PHYSICAL DEPENDENCE. IN THE CURRENT WORK WE EXPLORED HOW THE BALANCE OF HISTONE ACETYLTRANSFERASE (HAT) VERSUS HISTONE DEACETYLASE (HDAC) MIGHT REGULATE THESE MORPHINE-INDUCED CHANGES. NOCICEPTIVE THRESHOLDS, ANALGESIA, AND PHYSICAL DEPENDENCE WERE ASSESSED DURING AND FOR A PERIOD OF SEVERAL WEEKS AFTER MORPHINE EXPOSURE. TO PROBE THE ROLES OF HISTONE ACETYLATION, THE HAT INHIBITOR CURCUMIN OR A SELECTIVE HDAC INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) WAS ADMINISTERED DAILY TO GROUPS OF ANIMALS. HISTONE ACETYLATION IN SPINAL CORD WAS ASSESSED BY WESTERN BLOT AND IMMUNOHISTOCHEMISTRY. CONCURRENT ADMINISTRATION OF CURCUMIN WITH MORPHINE FOR 4 DAYS SIGNIFICANTLY REDUCED DEVELOPMENT OF OPIOID-INDUCED MECHANICAL ALLODYNIA, THERMAL HYPERALGESIA, TOLERANCE, AND PHYSICAL DEPENDENCE. CONVERSELY, THE HDAC INHIBITOR SAHA ENHANCED THESE RESPONSES. INTERESTINGLY, SAHA TREATMENT AFTER THE TERMINATION OF OPIOID ADMINISTRATION SUSTAINED THESE BEHAVIORAL CHANGES FOR AT LEAST 4 WEEKS. HISTONE H3 ACETYLATION IN THE DORSAL HORN OF THE SPINAL CORD WAS INCREASED AFTER CHRONIC MORPHINE TREATMENT, BUT H4 ACETYLATION WAS UNCHANGED. MOREOVER, WE OBSERVED A DECREASE IN HDAC ACTIVITY IN THE SPINAL CORDS OF MORPHINE-TREATED MICE WHILE OVERALL HAT ACTIVITY WAS UNCHANGED, SUGGESTING A SHIFT TOWARD A STATE OF ENHANCED HISTONE ACETYLATION. PERSPECTIVE: THE CURRENT STUDY INDICATES THAT EPIGENETIC MECHANISMS PLAY A CRUCIAL ROLE IN OPIOID-INDUCED LONG-LASTING NEUROPLASTICITY. THESE RESULTS PROVIDE NEW SIGHT INTO UNDERSTANDING THE MECHANISMS OF OPIOID-INDUCED NEUROPLASTICITY AND SUGGEST NEW STRATEGIES TO LIMIT OPIOID ABUSE POTENTIAL AND INCREASE THE VALUE OF THESE DRUGS AS ANALGESICS. 2013 10 1800 20 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 1003 27 CHRONIC TREATMENT WITH FLUOXETINE INDUCES SEX-DEPENDENT ANALGESIC EFFECTS AND MODULATES HDAC2 AND MGLU2 EXPRESSION IN FEMALE MICE. GENDER AND SEX DIFFERENCES IN PAIN RECOGNITION AND DRUG RESPONSES HAVE BEEN REPORTED IN CLINICAL TRIALS AND EXPERIMENTAL MODELS OF PAIN. AMONG ANTIDEPRESSANTS, CONTRADICTORY RESULTS HAVE BEEN OBSERVED IN PATIENTS TREATED WITH SELECTIVE SEROTONIN REUPTAKE INHIBITORS (SSRIS). THIS STUDY EVALUATED SEX DIFFERENCES IN RESPONSE TO THE SSRI FLUOXETINE AFTER CHRONIC ADMINISTRATION IN THE MOUSE FORMALIN TEST. ADULT MALE AND FEMALE CD1 MICE WERE INTRAPERITONEALLY INJECTED WITH FLUOXETINE (10 MG/KG) FOR 21 DAYS AND SUBJECTED TO PAIN ASSESSMENT. FLUOXETINE TREATMENT REDUCED THE SECOND PHASE OF THE FORMALIN TEST ONLY IN FEMALE MICE WITHOUT PRODUCING BEHAVIORAL CHANGES IN MALES. WE ALSO OBSERVED THAT FLUOXETINE WAS ABLE TO SPECIFICALLY INCREASE THE EXPRESSION OF METABOTROPIC GLUTAMATE RECEPTOR TYPE-2 (MGLU2) IN FEMALES. ALSO A REDUCED EXPRESSION OF THE EPIGENETIC MODIFYING ENZYME, HISTONE DEACETYLASE 2 (HDAC2), IN DORSAL ROOT GANGLIA (DRG) AND DORSAL HORN (DH) TOGETHER WITH AN INCREASE HISTONE 3 ACETYLATION (H3) LEVEL WAS OBSERVED IN FEMALES BUT NOT IN MALES. WITH THIS STUDY WE PROVIDE EVIDENCE THAT FLUOXETINE INDUCES SEX SPECIFIC CHANGES IN HDAC2 AND MGLU2 EXPRESSION IN THE DH OF THE SPINAL CORD AND IN DRGS AND SUGGESTS A MOLECULAR EXPLANATION FOR THE ANALGESIC EFFECTS IN FEMALE MICE. 2017 12 3892 35 L-ACETYLCARNITINE CAUSES RAPID ANTIDEPRESSANT EFFECTS THROUGH THE EPIGENETIC INDUCTION OF MGLU2 RECEPTORS. EPIGENETIC MECHANISMS ARE INVOLVED IN THE PATHOPHYSIOLOGY OF DEPRESSIVE DISORDERS AND ARE UNIQUE POTENTIAL TARGETS FOR THERAPEUTIC INTERVENTION. THE ACETYLATING AGENT L-ACETYLCARNITINE (LAC), A WELL-TOLERATED DRUG, BEHAVES AS AN ANTIDEPRESSANT BY THE EPIGENETIC REGULATION OF TYPE 2 METABOTROPIC GLUTAMATE (MGLU2) RECEPTORS. IT CAUSED A RAPID AND LONG-LASTING ANTIDEPRESSANT EFFECT IN FLINDERS SENSITIVE LINE RATS AND IN MICE EXPOSED TO CHRONIC UNPREDICTABLE STRESS, WHICH, RESPECTIVELY, MODEL GENETIC AND ENVIRONMENTALLY INDUCED DEPRESSION. IN BOTH MODELS, LAC INCREASED LEVELS OF ACETYLATED H3K27 BOUND TO THE GRM2 PROMOTER AND ALSO INCREASED ACETYLATION OF NF-KB-P65 SUBUNIT, THEREBY ENHANCING THE TRANSCRIPTION OF GRM2 GENE ENCODING FOR THE MGLU2 RECEPTOR IN HIPPOCAMPUS AND PREFRONTAL CORTEX. IMPORTANTLY, LAC REDUCED THE IMMOBILITY TIME IN THE FORCED SWIM TEST AND INCREASED SUCROSE PREFERENCE AS EARLY AS 3 D OF TREATMENT, WHEREAS 14 D OF TREATMENT WERE NEEDED FOR THE ANTIDEPRESSANT EFFECT OF CHLORIMIPRAMINE. MOREOVER, THERE WAS NO TOLERANCE TO THE ACTION OF LAC, AND THE ANTIDEPRESSANT EFFECT WAS STILL SEEN 2 WK AFTER DRUG WITHDRAWAL. CONVERSELY, NF-KB INHIBITION PREVENTED THE INCREASE IN MGLU2 EXPRESSION INDUCED BY LAC, WHEREAS THE USE OF A HISTONE DEACETYLASE INHIBITOR SUPPORTED THE EPIGENETIC CONTROL OF MGLU2 EXPRESSION. FINALLY, LAC HAD NO EFFECT ON MGLU2 KNOCKOUT MICE EXPOSED TO CHRONIC UNPREDICTABLE STRESS, AND A SINGLE INJECTION OF THE MGLU2/3 RECEPTOR ANTAGONIST LY341495 PARTIALLY BLOCKED LAC ACTION. THE RAPID AND LONG-LASTING ANTIDEPRESSANT ACTION OF LAC STRONGLY SUGGESTS A UNIQUE APPROACH TO EXAMINE THE EPIGENETIC HYPOTHESIS OF DEPRESSIVE DISORDERS IN HUMANS, PAVING THE WAY FOR MORE EFFICIENT ANTIDEPRESSANTS WITH FASTER ONSET OF ACTION. 2013 13 881 24 CHRONIC CLOZAPINE TREATMENT RESTRAINS VIA HDAC2 THE PERFORMANCE OF MGLU2 RECEPTOR AGONISM IN A RODENT MODEL OF ANTIPSYCHOTIC ACTIVITY. PRECLINICAL FINDINGS IN RODENT MODELS POINTED TOWARD ACTIVATION OF METABOTROPIC GLUTAMATE 2/3 (MGLU2/3) RECEPTORS AS A NEW PHARMACOLOGICAL APPROACH TO TREAT PSYCHOSIS. HOWEVER, MORE RECENT STUDIES FAILED TO SHOW CLINICAL EFFICACY OF MGLU2/3 RECEPTOR AGONISM IN SCHIZOPHRENIA PATIENTS. WE PREVIOUSLY PROPOSED THAT LONG-TERM ANTIPSYCHOTIC MEDICATION RESTRICTED THE THERAPEUTIC EFFECTS OF THESE GLUTAMATERGIC AGENTS. HOWEVER, LITTLE IS KNOWN ABOUT THE MOLECULAR MECHANISM UNDERLYING THE POTENTIAL REPERCUSSION OF PREVIOUS ANTIPSYCHOTIC EXPOSURE ON THE THERAPEUTIC PERFORMANCE OF MGLU2/3 RECEPTOR AGONISTS. HERE WE SHOW THAT THIS MALADAPTIVE EFFECT OF ANTIPSYCHOTIC TREATMENT IS MEDIATED MOSTLY VIA HISTONE DEACETYLASE 2 (HDAC2). CHRONIC TREATMENT WITH THE ANTIPSYCHOTIC CLOZAPINE LED TO A DECREASE IN MOUSE FRONTAL CORTEX MGLU2 MRNA, AN EFFECT THAT REQUIRED EXPRESSION OF BOTH HDAC2 AND THE SEROTONIN 5-HT(2A) RECEPTOR. THIS TRANSCRIPTIONAL ALTERATION OCCURRED IN ASSOCIATION WITH HDAC2-DEPENDENT REPRESSIVE HISTONE MODIFICATIONS AT THE MGLU2 PROMOTER. WE FOUND THAT CHRONIC CLOZAPINE TREATMENT DECREASED VIA HDAC2 THE CAPABILITIES OF THE MGLU2/3 RECEPTOR AGONIST LY379268 TO ACTIVATE G-PROTEINS IN THE FRONTAL CORTEX OF MICE. CHRONIC CLOZAPINE TREATMENT BLUNTED THE ANTIPSYCHOTIC-RELATED BEHAVIORAL EFFECTS OF LY379268, AN EFFECT THAT WAS NOT OBSERVED IN HDAC2 KNOCKOUT MICE. MORE IMPORTANTLY, CO-ADMINISTRATION OF THE CLASS I AND II HDAC INHIBITOR SAHA (VORINOSTAT) PRESERVED THE ANTIPSYCHOTIC PROFILE OF LY379268 AND FRONTAL CORTEX MGLU2/3 RECEPTOR DENSITY IN WILD-TYPE MICE. THESE FINDINGS RAISE CONCERNS ON THE DESIGN OF PREVIOUS CLINICAL STUDIES WITH MGLU2/3 AGONISTS, PROVIDING THE RATIONALE FOR THE DEVELOPMENT OF HDAC2 INHIBITORS AS A NEW EPIGENETIC-BASED APPROACH TO IMPROVE THE CURRENTLY LIMITED RESPONSE TO TREATMENT WITH GLUTAMATERGIC ANTIPSYCHOTICS. 2019 14 2910 26 GENE EXPRESSION PROFILING OF EPIGENETIC CHROMATIN MODIFICATION ENZYMES AND HISTONE MARKS BY CIGARETTE SMOKE: IMPLICATIONS FOR COPD AND LUNG CANCER. CHROMATIN-MODIFYING ENZYMES MEDIATE DNA METHYLATION AND HISTONE MODIFICATIONS ON RECRUITMENT TO SPECIFIC TARGET GENE LOCI IN RESPONSE TO VARIOUS STIMULI. THE KEY ENZYMES THAT REGULATE CHROMATIN ACCESSIBILITY FOR MAINTENANCE OF MODIFICATIONS IN DNA AND HISTONES, AND FOR MODULATION OF GENE EXPRESSION PATTERNS IN RESPONSE TO CIGARETTE SMOKE (CS), ARE NOT KNOWN. WE HYPOTHESIZE THAT CS EXPOSURE ALTERS THE GENE EXPRESSION PATTERNS OF CHROMATIN-MODIFYING ENZYMES, WHICH THEN AFFECTS MULTIPLE DOWNSTREAM PATHWAYS INVOLVED IN THE RESPONSE TO CS. WE HAVE, THEREFORE, ANALYZED CHROMATIN-MODIFYING ENZYME PROFILES AND VALIDATED BY QUANTITATIVE REAL-TIME PCR (QPCR). WE ALSO PERFORMED IMMUNOBLOT ANALYSIS OF TARGETED HISTONE MARKS IN C57BL/6J MICE EXPOSED TO ACUTE AND SUBCHRONIC CS, AND OF LUNGS FROM NONSMOKERS, SMOKERS, AND PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD). WE FOUND A SIGNIFICANT INCREASE IN EXPRESSION OF SEVERAL CHROMATIN MODIFICATION ENZYMES, INCLUDING DNA METHYLTRANSFERASES, HISTONE ACETYLTRANSFERASES, HISTONE METHYLTRANSFERASES, AND SET DOMAIN PROTEINS, HISTONE KINASES, AND UBIQUITINASES. OUR QPCR VALIDATION DATA REVEALED A SIGNIFICANT DOWNREGULATION OF DNMT1, DNMT3A, DNMT3B, HDAC2, HDAC4, HAT1, PRMT1, AND AURKB WE IDENTIFIED TARGETED CHROMATIN HISTONE MARKS (H3K56AC AND H4K12AC), WHICH ARE INDUCED BY CS. THUS CS-INDUCED GENOTOXIC STRESS DIFFERENTIALLY AFFECTS THE EXPRESSION OF EPIGENETIC MODULATORS THAT REGULATE TRANSCRIPTION OF TARGET GENES VIA DNA METHYLATION AND SITE-SPECIFIC HISTONE MODIFICATIONS. THIS MAY HAVE IMPLICATIONS IN DEVISING EPIGENETIC-BASED THERAPIES FOR COPD AND LUNG CANCER. 2016 15 3600 28 IMPORTANCE OF EPIGENETIC MECHANISMS IN VISCERAL PAIN INDUCED BY CHRONIC WATER AVOIDANCE STRESS. EPIGENETIC MOLECULAR MECHANISMS, WHICH INCLUDE DNA METHYLATION AND HISTONE DEACETYLATION, ARE IMPLICATED IN THE DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS. PREVIOUSLY, WE DEMONSTRATED THAT REPEATED WATER AVOIDANCE STRESS (WAS), A VALIDATED MODEL OF CHRONIC PSYCHOLOGICAL STRESS, INDUCES HEIGHTENED VISCERAL PAIN BEHAVIORS IN RODENTS THAT RESEMBLE IRRITABLE BOWEL SYNDROME (IBS) SEQUELAE. HOWEVER, THE INVOLVEMENT OF EPIGENETIC MOLECULAR MECHANISMS IN THE PATHOPHYSIOLOGY OF STRESS-INDUCED VISCERAL PAIN HAS NOT BEEN EXPLORED. OUR HYPOTHESIS IS THAT EPIGENETIC MECHANISMS WITHIN THE CENTRAL NERVOUS SYSTEM (CNS) ARE IMPORTANT TO CHRONIC STRESS-INDUCED VISCERAL HYPERSENSITIVITY. ADULT MALE F-344 RATS WITH INTRACEREBROVENTRICULAR (I.C.V.) CANNULAE WERE EXPOSED TO 7 DAYS OF REPEATED WAS. CONTROLS RECEIVED A SHAM STRESS. FOLLOWING THE DAILY 1H STRESSOR, TRICHOSTATIN A (TSA; 100 NG/ML), A POTENT HISTONE DEACETYLASE INHIBITOR, OR VEHICLE (VEH; 0.1% DMSO/SALINE,) AS CONTROL WAS ADMINISTERED VIA THE I.C.V. CANNULA. VISCERAL SENSITIVITY WAS ASSESSED 24H AFTER THE FINAL WAS AND QUANTIFIED THE VISCEROMOTOR RESPONSE (VMR) BY RECORDING THE NUMBER OF ABDOMINAL CONTRACTIONS IN RESPONSE TO GRADED PRESSURES (20-60 MMHG) OF COLORECTAL DISTENSIONS (CRD). FROM A SEPARATE GROUP OF RATS THAT WERE EXPOSED TO REPEATED WAS OR SHAM STRESS, THE AMYGDALA WAS ISOLATED TO ASSESS THE METHYLATION STATUS OF GLUCOCORTICOID RECEPTOR (GR) AND CORTICOTROPIN RELEASING-FACTOR (CRF) GENES VIA BISULFITE SEQUENCING AND VERIFIED BY PYROSEQUENCING. GR AND CRF GENE EXPRESSION WAS QUANTIFIED VIA QRT-PCR. STRESSED RATS EXHIBITED VISCERAL HYPERSENSITIVITY THAT WAS SIGNIFICANTLY ATTENUATED BY TSA. COMPARED TO SHAM CONTROLS, METHYLATION OF THE GR GENE WAS INCREASED FOLLOWING WAS WHILE EXPRESSION OF THE GR GENE WAS DECREASED. METHYLATION OF THE CRF PROMOTER WAS DECREASED WITH WAS WITH A CONCOMITANT INCREASE IN CRF EXPRESSION. THIS STUDY DEMONSTRATES THE INVOLVEMENT OF CENTRAL EPIGENETIC MECHANISMS IN REGULATING STRESS-INDUCED VISCERAL HYPERSENSITIVITY AND PROVIDES A FOUNDATION FOR EXPLORING THE EPIGENETIC MECHANISMS THAT MAY CONTRIBUTE TO IBS-LIKE SYMPTOMATOLOGY. 2013 16 2187 32 EPIGENETIC MECHANISMS UNDERLYING STRESS-INDUCED VISCERAL PAIN: RESILIENCE VERSUS VULNERABILITY IN A TWO-HIT MODEL OF EARLY LIFE STRESS AND CHRONIC ADULT STRESS. BACKGROUND: WOMEN WITH A HISTORY OF EARLY LIFE STRESS (ELS) HAVE A HIGHER RISK OF DEVELOPING IRRITABLE BOWEL SYNDROME (IBS). IN ADDITION, CHRONIC STRESS IN ADULTHOOD CAN EXACERBATE IBS SYMPTOMS SUCH AS ABDOMINAL PAIN DUE TO VISCERAL HYPERSENSITIVITY. WE PREVIOUSLY SHOWED THAT SEX AND THE PREDICTABILITY OF ELS DETERMINE WHETHER RATS DEVELOP VISCERAL HYPERSENSITIVITY IN ADULTHOOD. IN FEMALE RATS, UNPREDICTABLE ELS CONFERS VULNERABILITY AND RESULTS IN VISCERAL HYPERSENSITIVITY, WHEREAS PREDICTABLE ELS INDUCES RESILIENCE AND DOES NOT INDUCE VISCERAL HYPERSENSITIVITY IN ADULTHOOD. HOWEVER, THIS RESILIENCE IS LOST AFTER EXPOSURE TO CHRONIC STRESS IN ADULTHOOD LEADING TO AN EXACERBATION OF VISCERAL HYPERSENSITIVITY. EVIDENCE SUGGESTS THAT CHANGES IN HISTONE ACETYLATION AT THE PROMOTER REGIONS OF GLUCOCORTICOID RECEPTOR (GR) AND CORTICOTROPHIN-RELEASING FACTOR (CRF) IN THE CENTRAL NUCLEUS OF THE AMYGDALA (CEA) UNDERLIE STRESS-INDUCED VISCERAL HYPERSENSITIVITY. HERE, WE AIMED TO INVESTIGATE THE ROLE OF HISTONE ACETYLATION IN THE CEA ON VISCERAL HYPERSENSITIVITY IN A TWO-HIT MODEL OF ELS FOLLOWED BY CHRONIC STRESS IN ADULTHOOD. METHODS: MALE AND FEMALE NEONATAL RATS WERE EXPOSED TO UNPREDICTABLE, PREDICTABLE ELS, OR ODOR ONLY (NO STRESS CONTROL) FROM POSTNATAL DAYS 8 TO 12. IN ADULTHOOD, RATS UNDERWENT STEREOTAXIC IMPLANTATION OF INDWELLING CANNULAS. RATS WERE EXPOSED TO CHRONIC WATER AVOIDANCE STRESS (WAS, 1 H/DAY FOR 7 DAYS) OR SHAM STRESS AND RECEIVED INFUSIONS OF VEHICLE, THE HISTONE DEACETYLASE INHIBITOR TRICHOSTATIN A (TSA) OR THE HISTONE ACETYLTRANSFERASE INHIBITOR GARCINOL (GAR) AFTER EACH WAS SESSION. 24 H AFTER THE FINAL INFUSION, VISCERAL SENSITIVITY WAS ASSESSED AND THE CEA WAS REMOVED FOR MOLECULAR EXPERIMENTS. RESULTS: IN THE TWO-HIT MODEL (ELS + WAS), FEMALE RATS PREVIOUSLY EXPOSED TO PREDICTABLE ELS, SHOWED A SIGNIFICANT REDUCTION IN HISTONE 3 LYSINE 9 (H3K9) ACETYLATION AT THE GR PROMOTER AND A SIGNIFICANT INCREASE IN H3K9 ACETYLATION AT THE CRF PROMOTER. THESE EPIGENETIC CHANGES WERE ASSOCIATED WITH CHANGES IN GR AND CRF MRNA EXPRESSION IN THE CEA AND AN EXACERBATION OF STRESS-INDUCED VISCERAL HYPERSENSITIVITY IN FEMALE ANIMALS. TSA INFUSIONS IN THE CEA ATTENUATED THE EXACERBATED STRESS-INDUCED VISCERAL HYPERSENSITIVITY, WHEREAS GAR INFUSIONS ONLY PARTIALLY AMELIORATED ELS+WAS INDUCED VISCERAL HYPERSENSITIVITY. CONCLUSION: THE TWO-HIT MODEL OF ELS FOLLOWED BY WAS IN ADULTHOOD REVEALED THAT EPIGENETIC DYSREGULATION OCCURS AFTER EXPOSURE TO STRESS IN TWO IMPORTANT PERIODS OF LIFE AND CONTRIBUTES TO THE DEVELOPMENT OF VISCERAL HYPERSENSITIVITY. THESE ABERRANT UNDERLYING EPIGENETIC CHANGES MAY EXPLAIN THE EXACERBATION OF STRESS-INDUCED ABDOMINAL PAIN IN IBS PATIENTS. 2023 17 5617 28 SARCOSINE SUPPRESSES EPILEPTOGENESIS IN RATS WITH EFFECTS ON HIPPOCAMPAL DNA METHYLATION. EPILEPTOGENESIS IS A COMMON CONSEQUENCE OF BRAIN INSULTS, HOWEVER, THE PREVENTION OR DELAY OF THE EPILEPTOGENIC PROCESS REMAINS AN IMPORTANT UNMET MEDICAL CHALLENGE. OVEREXPRESSION OF GLYCINE TRANSPORTER 1 (GLYT1) IS PROPOSED AS A PATHOLOGICAL HALLMARK IN THE HIPPOCAMPUS OF PATIENTS WITH TEMPORAL LOBE EPILEPSY (TLE), AND WE PREVIOUSLY DEMONSTRATED IN RODENT EPILEPSY MODELS THAT AUGMENTATION OF GLYCINE SUPPRESSED CHRONIC SEIZURES AND ALTERED ACUTE SEIZURE THRESHOLDS. IN THE PRESENT STUDY WE EVALUATED THE EFFECT OF THE GLYT1 INHIBITOR, SARCOSINE (AKA N-METHYLGLYCINE), ON EPILEPTOGENESIS AND ALSO INVESTIGATED POSSIBLE MECHANISMS. WE DEVELOPED A MODIFIED RAPID KINDLING MODEL OF EPILEPTOGENESIS IN RATS COMBINED WITH SEIZURE SCORE MONITORING TO EVALUATE THE ANTIEPILEPTOGENIC EFFECT OF SARCOSINE. WE USED IMMUNOHISTOCHEMISTRY AND WESTERN BLOT ANALYSIS FOR THE EVALUATION OF GLYT1 EXPRESSION AND EPIGENETIC CHANGES OF 5-METHYLCYTOSINE (5MC) AND 5-HYDROXYMETHYLCYTOSINE (5HMC) IN THE EPILEPTOGENIC HIPPOCAMPI OF RATS, AND FURTHER EVALUATED EXPRESSION CHANGES IN ENZYMES INVOLVED IN THE REGULATION OF DNA METHYLATION, TEN-ELEVEN TRANSLOCATION METHYLCYTOSINE DIOXYGENASE 1 (TET1), DNA-METHYLTRANSFERASE 1 (DNMT1), AND DNMT3A. OUR RESULTS DEMONSTRATED: (I) EXPERIMENTAL EVIDENCE THAT SARCOSINE (3 G/KG, I.P. DAILY) SUPPRESSED KINDLING EPILEPTOGENESIS IN RATS; (II) THE SARCOSINE-INDUCED ANTIEPILEPTOGENIC EFFECT WAS ACCOMPANIED BY A SUPPRESSED HIPPOCAMPAL GLYT1 EXPRESSION AS WELL AS A REDUCTION OF HIPPOCAMPAL 5MC LEVELS AND A CORRESPONDING INCREASE IN 5HMC; AND (III) SARCOSINE TREATMENT CAUSED DIFFERENTIAL EXPRESSION CHANGES OF TET1 AND DNMTS. TOGETHER, THESE FINDINGS SUGGEST THAT SARCOSINE HAS UNPRECEDENTED DISEASE-MODIFYING PROPERTIES IN A KINDLING MODEL OF EPILEPTOGENESIS IN RATS, WHICH WAS ASSOCIATED WITH ALTERED HIPPOCAMPAL DNA METHYLATION. THUS, MANIPULATION OF THE GLYCINE SYSTEM IS A POTENTIAL THERAPEUTIC APPROACH TO ATTENUATE THE DEVELOPMENT OF EPILEPSY. 2020 18 2755 27 EXPRESSION OF CLASS II HISTONE DEACETYLASES IN TWO MOUSE MODELS OF TEMPORAL LOBE EPILEPSY. EPIGENETIC MECHANISMS LIKE ALTERED HISTONE ACETYLATION MAY HAVE A CRUCIAL ROLE IN EPILEPTOGENESIS. IN TWO MOUSE MODELS OF TEMPORAL LOBE EPILEPSY, WE INVESTIGATED CHANGES IN THE EXPRESSION OF CLASS II HISTONE DEACETYLASES (HDAC), A GROUP OF SIGNAL TRANSDUCERS THAT SHUTTLE BETWEEN NUCLEUS AND CYTOPLASM. INTRAHIPPOCAMPAL INJECTION OF KAINIC ACID (KA) INDUCED A STATUS EPILEPTICUS, DEVELOPMENT OF SPONTANEOUS SEIZURES (AFTER 3 DAYS), AND FINALLY CHRONIC EPILEPSY AND GRANULE CELL DISPERSION. EXPRESSION OF CLASS II HDAC MRNAS WAS INVESTIGATED AT DIFFERENT TIME INTERVALS AFTER KA INJECTION IN THE GRANULE CELL LAYERS AND IN SECTORS CA1 AND CA3 CONTRALATERAL TO THE SITE OF KA INJECTION LACKING NEURODEGENERATION. INCREASED EXPRESSION OF HDAC5 AND 9 MRNAS COINCIDED WITH PRONOUNCED GRANULE CELL DISPERSION IN THE KA-INJECTED HIPPOCAMPUS AT LATE INTERVALS (14-28 DAYS AFTER KA) AND EQUALLY AFFECTED BOTH HDAC9 SPLICE VARIANTS. IN CONTRAST, IN THE PILOCARPINE MODEL (SHOWING NO GRANULE CELL DISPERSION), WE OBSERVED DECREASES IN THE EXPRESSION OF HDAC5 AND 9 AT THE SAME TIME INTERVALS. BEYOND THIS, STRIKING SIMILARITIES BETWEEN BOTH TEMPORAL LOBE EPILEPSY MODELS SUCH AS FAST DECREASES IN HDAC7 AND 10 MRNAS DURING THE ACUTE STATUS EPILEPTICUS WERE OBSERVED, NOTABLY ALSO IN THE CONTRALATERAL HIPPOCAMPUS NOT AFFECTED BY NEURODEGENERATION. THE PARTICULAR PATTERNS OF HDAC MRNA EXPRESSION SUGGEST A ROLE IN EPILEPTOGENESIS AND GRANULE CELL DISPERSION. REDUCED EXPRESSION OF HDACS MAY RESULT IN INCREASED EXPRESSION OF PRO- AND ANTICONVULSIVE PROTEINS. ON THE OTHER HAND, EXPORT OF HDACS FROM THE NUCLEUS INTO THE CYTOPLASM COULD ALLOW FOR DEACETYLATION OF CYTOPLASMATIC PROTEINS INVOLVED IN AXONAL AND DENDRITIC REMODELING, LIKE GRANULE CELL DISPERSION. HDAC 5 AND HDAC 9 EXPRESSION IS HIGHLY INCREASED IN GRANULE CELLS OF THE KA-INJECTED HIPPOCAMPUS AND PARALLELS GRANULE CELL DISPERSION. BOTH HDACS ARE THOUGHT TO BE TARGETED TO THE CYTOPLASM AND TO ACT THERE BY DEACETYLATING CYTOPLASMATIC (E.G. CYTOSCELETON-RELATED) PROTEINS. 2016 19 6388 34 THE ROLE OF SIRT1 IN THE BASOLATERAL AMYGDALA IN DEPRESSION-LIKE BEHAVIORS IN MICE. PREVIOUS INVESTIGATIONS HAVE IMPLICATED THE BASOLATERAL AMYGDALA (BLA) EPIGENETIC MECHANISMS IN THE PATHOPHYSIOLOGY OF DEPRESSION. SIRT1 IS A NAD+-DEPENDENT CLASS III HISTONE DEACETYLASE, WIDELY EXPRESSES IN BLA. HOWEVER, EPIGENETIC MECHANISMS IN THE BLA UNDER THE REGULATION OF SIRT1 IN THE DEPRESSION ARE LARGELY UNCHARACTERIZED. UNDER THE CHRONIC UNPREDICTABLE CHRONIC MILD STRESS (CUMS) MOUSE MODEL, WE USED ADENO-ASSOCIATED VIRAL VECTORS (AAV) THAT ENCODED SIRT1-SHRNA OR SIRT1 TO SPECIFICALLY KNOCKDOWN OR OVEREXPRESS SIRT1 IN BLA NEURONS, RESPECTIVELY. CUMS PROCEDURE INDUCED SIGNIFICANT DEPRESSION SYMPTOMS INCLUDING THE DECREASED SUCROSE PREFERENCE, THE LESS BODYWEIGHT GAINED, THE DECREASED IMMOBILE LATENCY AND THE INCREASED IMMOBILE TIME BOTH IN FORCED SWIM TEST (FST) AND TAIL SUSPENSION TEST (TST). KNOCKDOWN OF SIRT1 IN BLA GLUTAMATERGIC NEURONS REVERSED THESE DEPRESSION-LIKE BEHAVIORS AND RESTORED THE SYNAPTIC ABNORMALITIES. OVEREXPRESSION OF SIRT1 IN BLA GLUTAMATERGIC NEURONS INDUCED DEPRESSION-LIKE BEHAVIORS IN NON-STRESSED CONTROL MICE. THE RESULT OF PROTEIN EXPRESSIONS AND ULTRASTRUCTURAL CHANGES WERE CONSISTENT WITH THE BEHAVIORAL RESULTS. OUR STUDY SUGGESTED THAT DOWNREGULATION OF SIRT1 IN BLA HAS CERTAIN BENEFICIAL EFFECT ON CUMS-INDUCED DEPRESSION-LIKE BEHAVIORS SUCH AS ANOREXIA, ANHEDONIA, HOPELESSNESS AND DESPAIR. IN ADDITION, THE INCREASED EXPRESSION OF SIRT1 MAY BE THE IMMEDIATE CAUSE OF DEPRESSIVE-LIKE SYMPTOMS. THE ABNORMAL EXPRESSION OF SIRT1 MAY AFFECT THE TRANSCRIPTIONAL REGULATION MECHANISM AND SIGNALING PROTEIN ACETYLATION, AFFECTING NEUROPLASTICITY AND ULTIMATELY CONTRIBUTE TO MDD. IN THE STRESS-SUSCEPTIBLE MICE, THESE TWO MECHANISMS MAY CO-EXIST, BUT THE SPECIFIC MECHANISM NEEDS FURTHER RESEARCH. 2021 20 5749 26 SOCIAL DEFEAT INDUCES CHANGES IN HISTONE ACETYLATION AND EXPRESSION OF HISTONE MODIFYING ENZYMES IN THE VENTRAL HIPPOCAMPUS, PREFRONTAL CORTEX, AND DORSAL RAPHE NUCLEUS. CHRONIC EXPOSURE TO STRESS IS ASSOCIATED WITH A NUMBER OF PSYCHIATRIC DISORDERS, BUT LITTLE IS KNOWN ABOUT THE EPIGENETIC MECHANISMS THAT UNDERLIE THE STRESS RESPONSE OR RESILIENCE TO CHRONIC STRESS. WE INVESTIGATED HISTONE ACETYLATION IN SEVEN DIFFERENT BRAIN REGIONS OF RATS EXPOSED TO CHRONIC SOCIAL DEFEAT STRESS: THE DORSAL HIPPOCAMPUS (DHPC), VENTRAL HIPPOCAMPUS (VHPC), MEDIAL PREFRONTAL CORTEX (MPFC), BASOLATERAL AMYGDALA (BLA), LOCUS COERULEUS (LC), PARAVENTRICULAR THALAMUS (PVT), AND DORSAL RAPHE (DR) NUCLEUS. THIS STRESS PARADIGM WAS UNIQUE IN THAT IT ALLOWED RATS TO DISPLAY RESILIENCE IN THE FORM OF AN ACTIVE COPING MECHANISM. WE FOUND THAT THERE WAS AN INCREASE IN ACETYLATION OF H3K9/14 (H3K9/14AC) AND BULK ACETYLATION OF H4K5,8,12,16 (H4K5,8,12,16AC) IN THE DR NUCLEUS OF RATS THAT WERE LESS RESILIENT. LESS RESILIENT RATS ALSO DISPLAYED INCREASED LEVELS OF H3K18 ACETYLATION (H3K18AC) IN THE MPFC WHEN COMPARED TO NON-STRESSED CONTROLS. IN THE VHPC, THERE WAS AN INCREASE IN H3K18AC AND H4K12 (H4K12AC) IN RATS THAT WERE LESS RESILIENT WHEN COMPARED TO NON-STRESSED CONTROL RATS. IN ADDITION, THERE WAS A DECREASE IN LEVELS OF H4K8 ACETYLATION (H4K8AC) IN BOTH RESILIENT AND NON-RESILIENT RATS AS COMPARED TO CONTROLS. WE ASSESSED EXPRESSION OF HISTONE MODIFYING ENZYMES IN THE VHPC AND THE MPFC USING QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (PCR) AND FOUND CHANGES IN EXPRESSION OF A NUMBER OF TARGETS. THESE INCLUDED CHANGES IN SIRT1 AND SIRT2 IN THE VHPC AND CHANGES IN KAT5 IN THE MPFC. OVERALL, THESE RESULTS SUGGEST THAT CHANGES IN HISTONE ACETYLATION AND EXPRESSION OF HISTONE MODIFYING ENZYMES IN THESE REGIONS CORRELATE WITH THE BEHAVIORAL RESPONSE TO STRESS IN SOCIALLY DEFEATED RATS. 2014