1 4262 114 MICE EXPOSED TO COMBINED CHRONIC LOW-DOSE IRRADIATION AND MODELED MICROGRAVITY DEVELOP LONG-TERM NEUROLOGICAL SEQUELAE. SPACEFLIGHT POSES MANY CHALLENGES FOR HUMANS. GROUND-BASED ANALOGS TYPICALLY FOCUS ON SINGLE PARAMETERS OF SPACEFLIGHT AND THEIR ASSOCIATED ACUTE EFFECTS. THIS STUDY ASSESSES THE LONG-TERM TRANSCRIPTIONAL EFFECTS FOLLOWING SINGLE AND COMBINATION SPACEFLIGHT ANALOG CONDITIONS USING THE MOUSE MODEL: SIMULATED MICROGRAVITY VIA HINDLIMB UNLOADING (HLU) AND/OR LOW-DOSE GAMMA-RAY IRRADIATION (LDR) FOR 21 DAYS, FOLLOWED BY 4 MONTHS OF READAPTATION. CHANGES IN GENE EXPRESSION AND EPIGENETIC MODIFICATIONS IN BRAIN SAMPLES DURING READAPTATION WERE ANALYZED BY WHOLE TRANSCRIPTOME SHOTGUN SEQUENCING (RNA-SEQ) AND REDUCED REPRESENTATION BISULFITE SEQUENCING (RRBS). THE RESULTS SHOWED MINIMAL GENE EXPRESSION AND CYTOSINE METHYLATION ALTERATIONS AT 4 MONTHS READAPTATION WITHIN SINGLE TREATMENT CONDITIONS OF HLU OR LDR. IN CONTRAST, FOLLOWING COMBINED HLU+LDR, GENE EXPRESSION AND PROMOTER METHYLATION ANALYSES SHOWED MULTIPLE ALTERED PATHWAYS INVOLVED IN NEUROGENESIS AND NEUROPLASTICITY, THE REGULATION OF NEUROPEPTIDES, AND CELLULAR SIGNALING. IN BRIEF, NEUROLOGICAL READAPTATION FOLLOWING COMBINED CHRONIC LDR AND HLU IS A DYNAMIC PROCESS THAT INVOLVES PATHWAYS THAT REGULATE NEURONAL FUNCTION AND STRUCTURE AND MAY LEAD TO LATE ONSET NEUROLOGICAL SEQUELAE. 2019 2 1135 21 COMPREHENSIVE MULTI-OMICS ANALYSIS REVEALS MITOCHONDRIAL STRESS AS A CENTRAL BIOLOGICAL HUB FOR SPACEFLIGHT IMPACT. SPACEFLIGHT IS KNOWN TO IMPOSE CHANGES ON HUMAN PHYSIOLOGY WITH UNKNOWN MOLECULAR ETIOLOGIES. TO REVEAL THESE CAUSES, WE USED A MULTI-OMICS, SYSTEMS BIOLOGY ANALYTICAL APPROACH USING BIOMEDICAL PROFILES FROM FIFTY-NINE ASTRONAUTS AND DATA FROM NASA'S GENELAB DERIVED FROM HUNDREDS OF SAMPLES FLOWN IN SPACE TO DETERMINE TRANSCRIPTOMIC, PROTEOMIC, METABOLOMIC, AND EPIGENETIC RESPONSES TO SPACEFLIGHT. OVERALL PATHWAY ANALYSES ON THE MULTI-OMICS DATASETS SHOWED SIGNIFICANT ENRICHMENT FOR MITOCHONDRIAL PROCESSES, AS WELL AS INNATE IMMUNITY, CHRONIC INFLAMMATION, CELL CYCLE, CIRCADIAN RHYTHM, AND OLFACTORY FUNCTIONS. IMPORTANTLY, NASA'S TWIN STUDY PROVIDED A PLATFORM TO CONFIRM SEVERAL OF OUR PRINCIPAL FINDINGS. EVIDENCE OF ALTERED MITOCHONDRIAL FUNCTION AND DNA DAMAGE WAS ALSO FOUND IN THE URINE AND BLOOD METABOLIC DATA COMPILED FROM THE ASTRONAUT COHORT AND NASA TWIN STUDY DATA, INDICATING MITOCHONDRIAL STRESS AS A CONSISTENT PHENOTYPE OF SPACEFLIGHT. 2020 3 918 28 CHRONIC HYPERGRAVITY INDUCES A MODIFICATION OF HISTONE H3 LYSINE 27 TRIMETHYLATION AT TCRBETA LOCUS IN MURINE THYMOCYTES. GRAVITY CHANGES ARE MAJOR STRESSORS ENCOUNTERED DURING SPACEFLIGHT THAT AFFECT THE IMMUNE SYSTEM. WE PREVIOUSLY EVIDENCED THAT HYPERGRAVITY EXPOSURE DURING GESTATION AFFECTS THE TCRBETA REPERTOIRE OF NEWBORN PUPS. TO IDENTIFY THE MECHANISMS UNDERLYING THIS OBSERVATION, WE STUDIED POST-TRANSLATIONAL HISTONE MODIFICATIONS. WE FIRST SHOWED THAT AMONG THE FOUR STUDIED POST-TRANSLATIONAL HISTONE H3 MODIFICATIONS, ONLY LYSINE 27 TRIMETHYLATION (H3K27ME3) IS DOWNREGULATED IN THE THYMUS OF MICE EXPOSED TO 2X G FOR 21 DAYS. WE THEN ASKED WHETHER THE TCRBETA LOCUS CHROMATIN STRUCTURE IS ALTERED BY HYPERGRAVITY EXPOSURE. CHIP STUDIES PERFORMED ON FOUR VBETA SEGMENTS OF THE MURINE DOUBLE-NEGATIVE SCIET27 THYMIC CELL LINE, WHICH CORRESPONDS TO THE LAST MATURATION STAGE BEFORE V(D)J RECOMBINATION, REVEALED INCREASES IN H3K27ME3 AFTER 2X G EXPOSURE. FINALLY, WE EVALUATED THE IMPLICATION FOR THE EZH2 METHYLTRANSFERASE IN THE REGULATION OF THE H3K27ME3 LEVEL AT THESE VBETA SEGMENTS BY TREATING SCIET27 CELLS WITH THE GSK126-SPECIFIC INHIBITOR. THESE EXPERIMENTS SHOWED THAT THE DOWNREGULATION OF H3K27ME3 CONTRIBUTES TO THE REGULATION OF THE VBETA GERMLINE TRANSCRIPT EXPRESSION THAT PRECEDES V(D)J RECOMBINATION. THESE DATA SHOW THAT MODIFICATIONS OF H3K27ME3 AT THE TCRBETA LOCUS LIKELY CONTRIBUTE TO AN EXPLANATION OF WHY THE TCR REPERTOIRE IS AFFECTED BY GRAVITY CHANGES AND IMPLY, FOR THE FIRST TIME, EZH2 IN THE REGULATION OF THE TCRBETA LOCUS CHROMATIN STRUCTURE. 2022 4 4919 27 PANNEXIN-1 UP-REGULATION IN THE DORSAL ROOT GANGLION CONTRIBUTES TO NEUROPATHIC PAIN DEVELOPMENT. PANNEXIN-1 (PANX1) IS A LARGE-PORE MEMBRANE CHANNEL INVOLVED IN THE RELEASE OF ATP AND OTHER SIGNALING MEDIATORS. LITTLE IS KNOWN ABOUT THE EXPRESSION AND FUNCTIONAL ROLE OF PANX1 IN THE DORSAL ROOT GANGLION (DRG) IN THE DEVELOPMENT OF CHRONIC NEUROPATHIC PAIN. IN THIS STUDY, WE DETERMINED THE EPIGENETIC MECHANISM INVOLVED IN INCREASED PANX1 EXPRESSION IN THE DRG AFTER NERVE INJURY. SPINAL NERVE LIGATION IN RATS SIGNIFICANTLY INCREASED THE MRNA AND PROTEIN LEVELS OF PANX1 IN THE DRG BUT NOT IN THE SPINAL CORD. IMMUNOCYTOCHEMICAL LABELING SHOWED THAT PANX1 WAS PRIMARILY EXPRESSED IN A SUBSET OF MEDIUM AND LARGE DRG NEURONS IN CONTROL RATS AND THAT NERVE INJURY MARKEDLY INCREASED THE NUMBER OF PANX1-IMMUNOREACTIVE DRG NEURONS. NERVE INJURY SIGNIFICANTLY INCREASED THE ENRICHMENT OF TWO ACTIVATING HISTONE MARKS (H3K4ME2 AND H3K9AC) AND DECREASED THE OCCUPANCY OF TWO REPRESSIVE HISTONE MARKS (H3K9ME2 AND H3K27ME3) AROUND THE PROMOTER REGION OF PANX1 IN THE DRG. HOWEVER, NERVE INJURY HAD NO EFFECT ON THE DNA METHYLATION LEVEL AROUND THE PANX1 PROMOTER IN THE DRG. FURTHERMORE, INTRATHECAL INJECTION OF THE PANX1 BLOCKERS OR PANX1-SPECIFIC SIRNA SIGNIFICANTLY REDUCED PAIN HYPERSENSITIVITY INDUCED BY NERVE INJURY. IN ADDITION, SIRNA KNOCKDOWN OF PANX1 EXPRESSION IN A DRG CELL LINE SIGNIFICANTLY REDUCED CASPASE-1 RELEASE INDUCED BY NEURONAL DEPOLARIZATION. OUR FINDINGS SUGGEST THAT NERVE INJURY INCREASES PANX1 EXPRESSION LEVELS IN THE DRG THROUGH ALTERED HISTONE MODIFICATIONS. PANX1 UP-REGULATION CONTRIBUTES TO THE DEVELOPMENT OF NEUROPATHIC PAIN AND STIMULATION OF INFLAMMASOME SIGNALING. 2015 5 6256 24 THE MITOGEN AND STRESS-ACTIVATED PROTEIN KINASE 1 REGULATES THE RAPID EPIGENETIC TAGGING OF DORSAL HORN NEURONS AND NOCIFENSIVE BEHAVIOUR. PHOSPHORYLATION OF HISTONE H3 AT SERINE 10 (P-H3S10) IS A MARKER OF ACTIVE GENE TRANSCRIPTION. USING COGNITIVE MODELS OF NEURAL PLASTICITY, P-H3S10 WAS SHOWN TO BE DOWNSTREAM OF EXTRACELLULAR SIGNAL-REGULATED KINASE (ERK) SIGNALLING IN THE HIPPOCAMPUS. IN THIS STUDY, WE SHOW THAT NOCICEPTIVE SIGNALLING AFTER PERIPHERAL FORMALIN INJECTION INCREASED P-H3S10 EXPRESSION IN THE IPSILATERAL DORSAL HORN. THIS INCREASE WAS MAXIMAL 30 MINUTES AFTER FORMALIN INJECTION AND OCCURRED MAINLY WITHIN P-ERK-POSITIVE NEURONS. SPINAL P-H3S10-ENHANCED EXPRESSION WAS ALSO OBSERVED IN NEUROKININ 1 RECEPTOR (NK1R), C-FOS, AND ZIF268 POSITIVE NEURONS AND WAS INHIBITED BY ABLATION OF SEROTONERGIC DESCENDING CONTROLS. THE MITOGEN AND STRESS-ACTIVATED PROTEIN KINASE 1 (MSK1) IS DOWNSTREAM OF ERK AND CAN INDUCE P-H3S10. WE FOUND THAT, AFTER FORMALIN INJECTION, MOST PHOSPHO-MSK1 (P-MSK1)-POSITIVE CELLS (87% +/- 3%) EXPRESSED P-ERK AND THE MAJORITY OF P-H3S10-POSITIVE CELLS (85% +/- 5%) EXPRESSED P-MSK1. INHIBITION OF ERK ACTIVITY WITH THE MEK INHIBITOR SL327 REDUCED FORMALIN-INDUCED P-ERK, P-MSK1, AND P-H3S10, DEMONSTRATING THAT SPINAL P-MSK1 AND P-H3S10 WERE AT LEAST PARTLY DOWNSTREAM OF ERK SIGNALLING. CRUCIALLY, PHARMACOLOGICAL BLOCKADE OF SPINAL MSK1 ACTIVITY WITH THE NOVEL MSK1 INHIBITOR SB727651A INHIBITED FORMALIN-INDUCED SPINAL P-H3S10 AND NOCIFENSIVE BEHAVIOUR. THESE FINDINGS ARE THE FIRST TO ESTABLISH THE INVOLVEMENT OF P-H3S10 AND ITS MAIN KINASE, MSK1, IN ERK REGULATION OF NOCICEPTION. GIVEN THE GENERAL IMPORTANCE OF ERK SIGNALLING IN PAIN PROCESSING, OUR RESULTS SUGGEST THAT P-H3S10 COULD PLAY A ROLE IN THE RESPONSE TO INJURY. 2016 6 1706 31 DYNORPHIN/KOP AND NOCICEPTIN/NOP GENE EXPRESSION AND EPIGENETIC CHANGES BY COCAINE IN RAT STRIATUM AND NUCLEUS ACCUMBENS. COCAINE INDUCES NEUROCHEMICAL CHANGES OF ENDOGENOUS PRODYNORPHIN-KAPPA OPIOID RECEPTOR (PDYN-KOP) AND PRONOCICEPTIN/ORPHANINFQ-NOCICEPTIN RECEPTOR (PN/OFQ-NOP) SYSTEMS. BOTH SYSTEMS PLAY AN IMPORTANT ROLE IN REWARDING MECHANISMS AND ADDICTIVE STIMULUS PROCESSING BY MODULATING DRUG-INDUCED DOPAMINERGIC ACTIVATION IN THE MESOCORTICO-LIMBIC BRAIN AREAS. THEY ARE ALSO INVOLVED IN REGULATING STRESS MECHANISMS RELATED TO ADDICTION. THE AIM OF THIS STUDY WAS TO INVESTIGATE POSSIBLE CHANGES OF GENE EXPRESSION OF THE DYNORPHINERGIC AND NOCICEPTINERGIC SYSTEM COMPONENTS IN THE NUCLEUS ACCUMBENS (NA) AND IN MEDIAL AND LATERAL CAUDATE PUTAMEN (MCPU AND LCPU, RESPECTIVELY) OF RATS, FOLLOWING CHRONIC SUBCUTANEOUS INFUSION OF COCAINE. IN ADDITION, THE EPIGENETIC HISTONE MODIFICATIONS H3K4ME3 AND H3K27ME3 (AN ACTIVATING AND A REPRESSIVE MARKER, RESPECTIVELY) AT THE PROMOTER LEVEL OF THE PDYN, KOP, PN/OFQ AND NOP GENES WERE INVESTIGATED. RESULTS SHOWED THAT COCAINE INDUCED PDYN GENE EXPRESSION UP-REGULATION IN THE NA AND LCPU, AND ITS DOWN-REGULATION IN THE MCPU, WHEREAS KOP MRNA LEVELS WERE UNCHANGED. MOREOVER, COCAINE EXPOSURE DECREASED PN/OFQ GENE EXPRESSION IN THE NA AND LCPU, WHILE NOP MRNA LEVELS APPEARED SIGNIFICANTLY INCREASED IN THE NA AND DECREASED IN THE LCPU. SPECIFIC CHANGES OF THE H3K4ME3 AND H3K27ME3 LEVELS WERE FOUND AT PDYN, PN/OFQ, AND NOP GENE PROMOTER, CONSISTENT WITH THE OBSERVED GENE EXPRESSION ALTERATIONS. THE PRESENT FINDINGS CONTRIBUTE TO BETTER DEFINE THE ROLE OF ENDOGENOUS PDYN-KOP AND PN/OFQ-NOP SYSTEMS IN NEUROPLASTICITY MECHANISMS FOLLOWING CHRONIC COCAINE TREATMENT. THE EPIGENETIC HISTONE MODIFICATIONS UNDERLYING THE GENE EXPRESSION CHANGES LIKELY MEDIATE THE EFFECTS OF COCAINE ON TRANSCRIPTIONAL REGULATION OF SPECIFIC GENE PROMOTERS THAT RESULT IN LONG-LASTING DRUG-INDUCED PLASTICITY. 2014 7 6673 25 USE OF COMPUTER TV MORPHODENSITOMETRY TO STUDY EPIGENETIC CHANGES IN BLOOD LYMPHOCYTES FROM CHILDREN AFFECTED BY LOW-DOSE IRRADIATION. A NOVEL METHOD, COMPUTER TV MORPHODENSITOMETRY, WAS USED TO EVALUATE THE EFFECTS OF LOW-DOSE IRRADIATION ON PERIPHERAL BLOOD LYMPHOCYTES FROM CHILDREN AFFECTED BY THE CHERNOBYL DISASTER. THIS METHOD USES DIGITIZED IMAGES TO DETECT AND MEASURE CHANGES IN CHROMATIN SHAPE AND DENSITY AND TO PRODUCE TWO-DIMENSIONAL AND THREE-DIMENSIONAL PICTURES. IMAGES CAN THEN BE STORED TO CREATE A VIDEO ARCHIVE. THIS METHOD IS SENSITIVE ENOUGH TO OBSERVE SUBTLE CHANGES IN CHROMATIN STRUCTURE THAT PREVIOUSLY COULD BE DETECTED ONLY BY MORE DETAILED MOLECULAR ANALYSES. IN THIS STUDY, LYMPHOCYTE INTERPHASE NUCLEI IN DNA-STAINED BLOOD SMEARS FROM CHILDREN SUBJECTED TO CHRONIC LOW-DOSE IRRADIATION WERE EXAMINED BY COMPUTER TV MORPHODENSITOMETRY. PRELIMINARY DATA INDICATE THAT CIRCULATING LYMPHOCYTES FROM CHILDREN EXPOSED TO RADIATION MAY CONTAIN SIGNIFICANT ALTERATIONS IN THE STRUCTURE AND/OR DENSITY OF NUCLEAR CHROMATIN. 1997 8 5556 23 ROLE OF FLUORIDE INDUCED HISTONE TRIMETHYLATION IN DEVELOPMENT OF SKELETAL FLUOROSIS. CHRONIC EXPOSURE TO FLUORIDE HAS BEEN ASSOCIATED WITH THE DEVELOPMENT OF SKELETAL FLUOROSIS. LIMITED REPORTS ARE AVAILABLE ON FLUORIDE INDUCED HISTONE MODIFICATION. HOWEVER, THE ROLE OF HISTONE MODIFICATION IN THE PATHOGENESIS OF SKELETAL FLUOROSIS IS NOT INVESTIGATED. IN THE PRESENT STUDY, WE HAVE INVESTIGATED THE ROLE OF FLUORIDE INDUCED HISTONE MODIFICATION ON FLUOROSIS DEVELOPMENT USING HUMAN OSTEOSARCOMA (HOS) CELL LINE. THE EXPRESSION OF HISTONE METHYLTRANSFERASES (EHMT1 AND EHZ2) AND LEVEL OF GLOBAL HISTONE TRIMETHYLATION (H3K9 AND H3K27) HAVE BEEN ASSESSED AND OBSERVED TO BE INCREASED SIGNIFICANTLY AFTER FLUORIDE EXPOSURE (8 MG/L). EPITECT CHROMATIN IMMUNOPRECIPITATION (CHIP) QPCR ARRAY (HUMAN TGFBETA/BMP SIGNALING PATHWAY) WAS PERFORMED TO ASSESS THE H3K9 TRIMETHYLATION AT PROMOTER REGIONS OF PATHWAY-SPECIFIC GENES. H3K9 CHIP PCR ARRAY ANALYSIS IDENTIFIED HYPER H3K9 TRIMETHYLATION IN PROMOTER REGIONS OF TGFBR2 AND SMAD3. QPCR AND STRING ANALYSIS WAS CARRIED OUT TO DETERMINE THE REPRESSIVE EPIGENETIC EFFECT OF H3K9 TRIMETHYLATION ON EXPRESSION PATTERN AND FUNCTIONAL ASSOCIATION OF IDENTIFIED GENES. IDENTIFIED GENES (TGFBR2 AND SMAD3) SHOWED DOWN-REGULATION WHICH CONFIRMS THE REPRESSIVE EPIGENETIC EFFECT OF PROMOTER H3K9 HYPER TRIMETHYLATION. EXPRESSION OF TWO OTHER VITAL GENES COL1A1 AND MMP13 INVOLVED IN TGFBR2-SMAD SIGNALING PATHWAY WAS ALSO FOUND TO BE DOWN-REGULATED WITH A DECREASE IN EXPRESSION OF TGFBR2 AND SMAD3. STRING ANALYSIS REVEALED FUNCTIONAL ASSOCIATION AND INVOLVEMENT OF IDENTIFIED GENES TGFBR2, SMAD3, COL1A1 AND MMP13 IN THE COLLAGEN AND CARTILAGE DEVELOPMENT/MORPHOGENESIS, CONNECTIVE TISSUE FORMATION, BIO-MINERAL TISSUE DEVELOPMENT, ENDOCHONDRAL BONE FORMATION, BONE AND SKELETAL MORPHOGENESIS. IN CONCLUSION, PRESENT INVESTIGATION IS A FIRST ATTEMPT TO LINK FLUORIDE INDUCED HYPER H3K9 TRI-METHYLATION MEDIATED REPRESSION OF TGFBR2 AND SMAD3 WITH THE DEVELOPMENT OF SKELETAL FLUOROSIS. 2018 9 6556 18 TRANSGENERATIONAL EFFECTS OF POLYETHYLENE MICROPLASTIC FRAGMENTS CONTAINING BENZOPHENONE-3 ADDITIVE IN DAPHNIA MAGNA. MATERNAL EXPOSURE TO MICROPLASTICS (MPS) PLAYS AN IMPORTANT ROLE IN THE FITNESS OF UNEXPOSED PROGENY. IN THIS STUDY, THE TRANSGENERATIONAL EFFECTS OF POLYETHYLENE MP FRAGMENTS (17.35 +/- 5.50 MICROM) CONTAINING BENZOPHENONE-3 (BP-3; 2.85 +/- 0.16% W/W) ON CHRONIC TOXICITY (21 D) IN DAPHNIA MAGNA WERE INVESTIGATED ACROSS FOUR GENERATIONS. ONLY D. MAGNA IN THE F0 GENERATION WAS EXPOSED TO MP FRAGMENTS, MP/BP-3 FRAGMENTS, AND BP-3 LEACHATE TO IDENTIFY THE TRANSGENERATIONAL EFFECT IN THE F3 GENERATION. THE MORTALITY OF D. MAGNA INDUCED BY MP AND MP/BP-3 FRAGMENTS WAS RECOVERED IN THE F3 GENERATION, BUT SOMATIC GROWTH AND REPRODUCTION SIGNIFICANTLY DECREASED COMPARED TO THE CONTROL. ADDITIONALLY, REPRODUCTION OF D. MAGNA EXPOSED TO BP-3 LEACHATE SIGNIFICANTLY DECREASED IN THE F3 GENERATION. THESE FINDINGS CONFIRMED THE TRANSGENERATIONAL EFFECTS OF MP FRAGMENT AND BP-3 ADDITIVE ON D. MAGNA. PARTICULARLY, THE ADVERSE EFFECT ON D. MAGNA REPRODUCTION SEEMED TO BE CUMULATIVE ACROSS FOUR GENERATIONS FOR MP/BP-3 FRAGMENTS, WHILE IT WAS AN ACCLIMATION TREND FOR BP-3 LEACHATE. HOWEVER, THERE WAS NO SIGNIFICANT DIFFERENCE IN GLOBAL DNA METHYLATION IN D. MAGNA ACROSS FOUR GENERATIONS, THUS REQUIRING A GENE-SPECIFIC DNA METHYLATION STUDY TO IDENTIFY DIFFERENT EPIGENETIC TRANSGENERATIONAL INHERITANCE. 2022 10 2863 26 FUNCTION OF DNA METHYLTRANSFERASE 3A IN LEAD (PB(2+) )-INDUCED CYCLOOXYGENASE-2 GENE. LEAD IONS (PB(2+) ) ARE TOXIC INDUSTRIAL POLLUTANTS ASSOCIATED WITH CHRONIC INFLAMMATORY DISEASES IN HUMANS AND ANIMALS. PREVIOUSLY, WE FOUND THAT PB(2+) IONS INDUCE COX-2 GENE EXPRESSION VIA THE EGF RECEPTOR/NUCLEAR FACTOR-KAPPAB SIGNAL TRANSDUCTION PATHWAY IN EPIDERMOID CARCINOMA CELL LINE A431. IN THIS STUDY, TO SEE WHETHER PB(2+) IONS AFFECT COX-2 EXPRESSION BY EPIGENETIC MECHANISMS, WE LOOKED AT THE MRNAS OF DNA METHYLTRANSFERASES (DNMTS) USING REAL-TIME PCR OF TOTAL RNA FROM THESE CELLS. CELLS EXPOSED TO PB(2+) HAD LOW LEVELS OF DNMT3A MRNA, WHEREAS THE LEVELS OF DNMT1 AND DNMT3B MRNAS REMAINED UNCHANGED. PRETREATMENT OF CELLS WITH DNMT INHIBITOR 5-AZA-2'-DEOXYCYTIDINE (5 MUM) FOLLOWED BY PB(2+) (1 MUM) SIGNIFICANTLY INCREASED LEVELS OF COX-2 MRNA COMPARED WITH CELLS TREATED WITH PB(2+) ALONE. OVEREXPRESSION OF TUMOR SUPPRESSOR GENE RB CORRELATED WITH AN INCREASE IN COX-2 MRNA AND A DECREASE IN DNMT3A MRNA. CONVERSELY, OVEREXPRESSION OF TRANSCRIPTION FACTOR E2F1 CORRELATED WITH A DECREASE IN COX-2 MRNA AND AN INCREASE IN DMNT3A MRNA. PRETREATMENT WITH EGFR INHIBITORS AG1478 AND PD153035 SIGNIFICANTLY LIMITED PB(2+) -INDUCED REDUCTION IN DNMT3A MRNA. IN ADDITION, GENE KNOCKDOWN OF DNMT3A WITH SHORT HAIRPIN RNA CORRELATED WITH INCREASED COX-2 MRNA INDUCED BY PB(2+) . OUR FINDINGS SUGGEST PB(2+) IONS INDUCE COX-2 EXPRESSION INDIRECTLY BY REDUCING DNMT3A METHYLATION OF THE COX-2 PROMOTER VIA TRANSCRIPTION FACTORS RB AND E2F1. 2015 11 1000 28 CHRONIC T CELL RECEPTOR STIMULATION UNMASKS NK RECEPTOR SIGNALING IN PERIPHERAL T CELL LYMPHOMAS VIA EPIGENETIC REPROGRAMMING. PERIPHERAL T CELL LYMPHOMAS (PTCLS) REPRESENT A SIGNIFICANT UNMET MEDICAL NEED WITH DISMAL CLINICAL OUTCOMES. THE T CELL RECEPTOR (TCR) IS EMERGING AS A KEY DRIVER OF T LYMPHOCYTE TRANSFORMATION. HOWEVER, THE ROLE OF CHRONIC TCR ACTIVATION IN LYMPHOMAGENESIS AND IN LYMPHOMA CELL SURVIVAL IS STILL POORLY UNDERSTOOD. USING A MOUSE MODEL, WE REPORT THAT CHRONIC TCR STIMULATION DROVE T CELL LYMPHOMAGENESIS, WHEREAS TCR SIGNALING DID NOT CONTRIBUTE TO PTCL SURVIVAL. THE COMBINATION OF KINOME, TRANSCRIPTOME, AND EPIGENOME ANALYSES OF MOUSE PTCLS REVEALED A NK CELL-LIKE REPROGRAMMING OF PTCL CELLS WITH EXPRESSION OF NK RECEPTORS (NKRS) AND DOWNSTREAM SIGNALING MOLECULES SUCH AS TYROBP AND SYK. ACTIVATING NKRS WERE FUNCTIONAL IN PTCLS AND DEPENDENT ON SYK ACTIVITY. IN VIVO BLOCKADE OF NKR SIGNALING PROLONGED MOUSE SURVIVAL, DEMONSTRATING THE ADDICTION OF PTCLS TO NKRS AND DOWNSTREAM SYK/MTOR ACTIVITY FOR THEIR SURVIVAL. WE STUDIED A LARGE COLLECTION OF HUMAN PRIMARY SAMPLES AND IDENTIFIED SEVERAL PTCLS RECAPITULATING THE PHENOTYPE DESCRIBED IN THIS MODEL BY THEIR EXPRESSION OF SYK AND THE NKR, SUGGESTING A SIMILAR MECHANISM OF LYMPHOMAGENESIS AND ESTABLISHING A RATIONALE FOR CLINICAL STUDIES TARGETING SUCH MOLECULES. 2021 12 1274 25 DACH1 PROTECTS PODOCYTES FROM EXPERIMENTAL DIABETIC INJURY AND MODULATES PTIP-H3K4ME3 ACTIVITY. DACHSHUND HOMOLOG 1 (DACH1), A KEY CELL-FATE DETERMINANT, REGULATES TRANSCRIPTION BY DNA SEQUENCE-SPECIFIC BINDING. WE IDENTIFIED DIMINISHED DACH1 EXPRESSION IN A LARGE-SCALE SCREEN FOR MUTATIONS THAT CONVERT INJURY-RESISTANT PODOCYTES INTO INJURY-SUSCEPTIBLE PODOCYTES. IN DIABETIC KIDNEY DISEASE (DKD) PATIENTS, PODOCYTE DACH1 EXPRESSION LEVELS ARE DIMINISHED, A CONDITION THAT STRONGLY CORRELATES WITH POOR CLINICAL OUTCOMES. GLOBAL DACH1 KO MICE MANIFEST RENAL HYPOPLASIA AND DIE PERINATALLY. PODOCYTE-SPECIFIC DACH1 KO MICE, HOWEVER, MAINTAIN NORMAL GLOMERULAR ARCHITECTURE AT BASELINE, BUT RAPIDLY EXHIBIT PODOCYTE INJURY AFTER DIABETES ONSET. FURTHERMORE, PODOCYTE-SPECIFIC AUGMENTATION OF DACH1 EXPRESSION IN MICE PROTECTS FROM DKD. COMBINED RNA SEQUENCING AND IN SILICO PROMOTER ANALYSIS REVEAL CONVERSELY OVERLAPPING GLOMERULAR TRANSCRIPTOMIC SIGNATURES BETWEEN PODOCYTE-SPECIFIC DACH1 AND PAX TRANSACTIVATION-DOMAIN INTERACTING PROTEIN (PTIP) KO MICE, WITH UPREGULATED GENES POSSESSING HIGHER-THAN-EXPECTED NUMBERS OF PROMOTER DACH1-BINDING SITES. PTIP, AN ESSENTIAL COMPONENT OF THE ACTIVATING HISTONE H3 LYSINE 4 TRIMETHYLATION (H3K4ME3) COMPLEX, INTERACTS WITH DACH1 AND IS RECRUITED BY DACH1 TO ITS PROMOTER-BINDING SITES. DACH1-PTIP RECRUITMENT REPRESSES TRANSCRIPTION AND REDUCES PROMOTER H3K4ME3 LEVELS. DACH1 KNOCKDOWN IN PODOCYTES COMBINED WITH HYPERGLYCEMIA TRIGGERS TARGET GENE UPREGULATION AND INCREASES PROMOTER H3K4ME3. THESE FINDINGS REVEAL THAT IN DKD, DIMINISHED DACH1 EXPRESSION ENHANCES PODOCYTE INJURY VULNERABILITY VIA EPIGENETIC DEREPRESSION OF ITS TARGET GENES. 2021 13 786 27 CELL-TYPE-SPECIFIC EPIGENETIC EDITING AT THE FOSB GENE CONTROLS SUSCEPTIBILITY TO SOCIAL DEFEAT STRESS. CHRONIC SOCIAL DEFEAT STRESS REGULATES THE EXPRESSION OF FOSB IN THE NUCLEUS ACCUMBENS (NAC) TO PROMOTE THE CELL-TYPE-SPECIFIC ACCUMULATION OF DELTAFOSB IN THE TWO MEDIUM SPINY NEURON (MSN) SUBTYPES IN THIS REGION. DELTAFOSB IS SELECTIVELY INDUCED IN D1-MSNS IN THE NAC OF RESILIENT MICE, AND IN D2-MSNS OF SUSCEPTIBLE MICE. HOWEVER, LITTLE IS KNOWN ABOUT THE CONSEQUENCES OF SUCH SELECTIVE INDUCTION, PARTICULARLY IN D2-MSNS. THIS STUDY EXAMINED HOW CELL-TYPE-SPECIFIC CONTROL OF THE ENDOGENOUS FOSB GENE IN NAC REGULATES SUSCEPTIBILITY TO SOCIAL DEFEAT STRESS. HISTONE POST-TRANSLATIONAL MODIFICATIONS (HPTMS) WERE TARGETED SPECIFICALLY TO FOSB USING ENGINEERED ZINC-FINGER PROTEINS (ZFPS). FOSB-ZFPS WERE FUSED TO EITHER THE TRANSCRIPTIONAL REPRESSOR, G9A, WHICH PROMOTES HISTONE METHYLATION OR THE TRANSCRIPTIONAL ACTIVATOR, P65, WHICH PROMOTES HISTONE ACETYLATION. THESE ZFPS WERE EXPRESSED IN D1- VS D2-MSNS USING CRE-DEPENDENT VIRAL EXPRESSION IN THE NAC OF MICE TRANSGENIC FOR CRE RECOMBINASE IN THESE MSN SUBTYPES. WE FOUND THAT STRESS SUSCEPTIBILITY IS OPPOSITELY REGULATED BY THE SPECIFIC CELL TYPE AND HPTM TARGETED. WE REPORT THAT FOSB-TARGETED HISTONE ACETYLATION IN D2-MSNS OR HISTONE METHYLATION IN D1-MSNS PROMOTES A STRESS-SUSCEPTIBLE, DEPRESSIVE-LIKE PHENOTYPE, WHILE HISTONE METHYLATION IN D2-MSNS OR HISTONE ACETYLATION IN D1-MSNS INCREASES RESILIENCE TO SOCIAL STRESS AS QUANTIFIED BY SOCIAL INTERACTION BEHAVIOR AND SUCROSE PREFERENCE. THIS WORK PRESENTS THE FIRST DEMONSTRATION OF CELL- AND GENE-SPECIFIC TARGETING OF HISTONE MODIFICATIONS, WHICH MODEL NATURALLY OCCURRING TRANSCRIPTIONAL PHENOMENA THAT CONTROL SOCIAL DEFEAT STRESS BEHAVIOR. THIS EPIGENETIC-EDITING APPROACH, WHICH RECAPITULATES PHYSIOLOGICAL CHANGES IN GENE EXPRESSION, REVEALS CLEAR DIFFERENCES IN THE SOCIAL DEFEAT PHENOTYPE INDUCED BY FOSB GENE MANIPULATION IN MSN SUBTYPES. 2018 14 1421 25 DIFFERENTIAL BRAIN ADRA2A AND ADRA2C GENE EXPRESSION AND EPIGENETIC REGULATION IN SCHIZOPHRENIA. EFFECT OF ANTIPSYCHOTIC DRUG TREATMENT. POSTSYNAPTIC ALPHA(2A)-ADRENOCEPTOR DENSITY IS ENHANCED IN THE DORSOLATERAL PREFRONTAL CORTEX (DLPFC) OF ANTIPSYCHOTIC-TREATED SCHIZOPHRENIA SUBJECTS. THIS ALTERATION MIGHT BE DUE TO TRANSCRIPTIONAL ACTIVATION, AND COULD BE REGULATED BY EPIGENETIC MECHANISMS SUCH AS HISTONE POSTTRANSLATIONAL MODIFICATIONS (PTMS). THE AIM OF THIS STUDY WAS TO EVALUATE ADRA2A AND ADRA2C GENE EXPRESSION (CODIFYING FOR ALPHA(2)-ADRENOCEPTOR SUBTYPES), AND PERMISSIVE AND REPRESSIVE HISTONE PTMS AT GENE PROMOTER REGIONS IN THE DLPFC OF SUBJECTS WITH SCHIZOPHRENIA AND MATCHED CONTROLS (N = 24 PAIRS). WE STUDIED THE EFFECT OF ANTIPSYCHOTIC (AP) TREATMENT IN AP-FREE (N = 12) AND AP-TREATED (N = 12) SUBGROUPS OF SCHIZOPHRENIA SUBJECTS AND IN RATS ACUTELY AND CHRONICALLY TREATED WITH TYPICAL AND ATYPICAL ANTIPSYCHOTICS. ADRA2A MRNA EXPRESSION WAS SELECTIVELY UPREGULATED IN AP-TREATED SCHIZOPHRENIA SUBJECTS (+93%) WHEREAS ADRA2C MRNA EXPRESSION WAS UPREGULATED IN ALL SCHIZOPHRENIA SUBJECTS (+53%) REGARDLESS OF ANTIPSYCHOTIC TREATMENT. ACUTE AND CHRONIC CLOZAPINE TREATMENT IN RATS DID NOT ALTER BRAIN CORTEX ADRA2A MRNA EXPRESSION BUT INCREASED ADRA2C MRNA EXPRESSION. BOTH ADRA2A AND ADRA2C PROMOTER REGIONS SHOWED EPIGENETIC MODIFICATION BY HISTONE METHYLATION AND ACETYLATION IN HUMAN DLPFC. THE UPREGULATION OF ADRA2A EXPRESSION IN AP-TREATED SCHIZOPHRENIA SUBJECTS MIGHT BE RELATED TO OBSERVED BIVALENT CHROMATIN AT ADRA2A PROMOTER REGION IN SCHIZOPHRENIA (DEPICTED BY INCREASED PERMISSIVE H3K4ME3 AND REPRESSIVE H3K27ME3) AND COULD BE TRIGGERED BY THE ENHANCED H4K16AC AT ADRA2A PROMOTER. IN CONCLUSION, EPIGENETIC PREDISPOSITION DIFFERENTIALLY MODULATED ADRA2A AND ADRA2C MRNA EXPRESSION IN DLPFC OF SCHIZOPHRENIA SUBJECTS. 2021 15 5201 24 PRENATAL MORPHINE EXPOSURE INCREASES GAMMA OSCILLATION AND THETA COHERENCE IN THE RAT REWARD SYSTEM. PREVIOUS STUDIES HAVE FOUND THAT PRENATAL MORPHINE (PNM) EXPOSURE LEADS TO BOTH INCREASED AND DECREASED RISK OF SUBSTANCE ABUSE IN OFFSPRING. UNDERSTANDING MORE ABOUT THE NEUROBIOLOGICAL CHANGES AFTER THE PNM EXPOSURE WOULD HELP TO UNDERSTAND MORE ABOUT THIS ISSUE. SIGNALING FROM DOPAMINE NEURONS OF THE VENTRAL TEGMENTAL AREA (VTA) IN THE MESOACCUMBAL AND MESOCORTICAL PATHWAYS PLAYS A VITAL ROLE IN DRUG DEPENDENCY. TO PROVIDE FURTHER KNOWLEDGE ABOUT THE EFFECTS OF PNM ON DRUG SEEKING BEHAVIOR AND THE DOPAMINE SYSTEM. WE RECORDED LOCAL FIELD POTENTIALS (LFP) SIMULTANEOUSLY IN THE VTA, NAC (NUCLEUS ACCUMBENS), BLA (BASOLATERAL AMYGDALA) AND MPFC (MEDIAL PREFRONTAL CORTEX) IN MALE ADULT RATS PRENATALLY TREATED WITH SALINE OR MORPHINE. MORPHINE (10 MG/KG) INDUCED CONDITIONED PLACE PREFERENCE (CPP) ESTABLISHMENT, EXTINCTION AND PRIMING WERE TESTED TO INVESTIGATE THE EFFECTS OF PNM ON ADDICTIVE-LIKE BEHAVIOR. IN ADDITION, THE EXPRESSION OF NUCLEAR HISTONE DEACETYLASES (HDAC4, HDAC5), WHICH PLAYS ESSENTIAL EPIGENETIC ROLES IN NEUROPLASTICITY AFTER DRUG USE WERE ALSO TESTED IN VTA AND NAC. THE RESULTS SHOWED THAT PNM DID NOT CHANGE THE ACQUISITION OF MORPHINE CPP IN MALE RATS, BUT IMPAIRED CPP EXTINCTION AND MORPHINE (5 MG/KG) - PRIMED REINSTATEMENT OF CPP AFTER EXTINCTION. PNM INCREASED THE LOW GAMMA (30-60 HZ) AND HIGH (60-90 HZ) GAMMA LFP POWERS IN NAC AND BLA. PNM ALSO LEADS TO INCREASED THETA (4-9 HZ) COHERENCE BETWEEN VTA AND NAC, AND INCREASED HDAC5 EXPRESSION IN VTA. AFTER CHRONIC MORPHINE ADMINISTRATION, COHERENCE BETWEEN VTA-NAC, MPFC-NAC AND MPFC-BLA INCREASED SIGNIFICANTLY IN PNS RATS, BUT NO CHANGES WERE FIND IN PNM RATS, INDICATING IMPAIRED PLASTICITY IN BRAIN CIRCUITS. ALL THESE RESULTS SUGGEST THAT PNM EXPOSURE INCREASED REWARD PROCESSING IN ADULT MALE RATS, BUT IMPAIRED MORPHINE CPP EXTINCTION AND REINSTATEMENT, WHICH RELATE TO DECREASES NETWORK PLASTICITY AND INCREASED HDAC5 EXPRESSION IN THE REWARD SYSTEM. 2022 16 5063 22 PHOSPHORYLATED HISTONE 3 AT SERINE 10 IDENTIFIES ACTIVATED SPINAL NEURONS AND CONTRIBUTES TO THE DEVELOPMENT OF TISSUE INJURY-ASSOCIATED PAIN. TRANSCRIPTIONAL CHANGES IN SUPERFICIAL SPINAL DORSAL HORN NEURONS (SSDHN) ARE ESSENTIAL IN THE DEVELOPMENT AND MAINTENANCE OF PROLONGED PAIN. EPIGENETIC MECHANISMS INCLUDING POST-TRANSLATIONAL MODIFICATIONS IN HISTONES ARE PIVOTAL IN REGULATING TRANSCRIPTION. HERE, WE REPORT THAT PHOSPHORYLATION OF SERINE 10 (S10) IN HISTONE 3 (H3) SPECIFICALLY OCCURS IN A GROUP OF RAT SSDHN FOLLOWING THE ACTIVATION OF NOCICEPTIVE PRIMARY SENSORY NEURONS BY BURN INJURY, CAPSAICIN APPLICATION OR SUSTAINED ELECTRICAL ACTIVATION OF NOCICEPTIVE PRIMARY SENSORY NERVE FIBRES. IN CONTRAST, BRIEF THERMAL OR MECHANICAL NOCICEPTIVE STIMULI, WHICH FAIL TO INDUCE TISSUE INJURY OR INFLAMMATION, DO NOT PRODUCE THE SAME EFFECT. BLOCKING N-METHYL-D-ASPARTATE RECEPTORS OR ACTIVATION OF EXTRACELLULAR SIGNAL-REGULATED KINASES 1 AND 2, OR BLOCKING OR DELETING THE MITOGEN- AND STRESS-ACTIVATED KINASES 1 AND 2 (MSK1/2), WHICH PHOSPHORYLATE S10 IN H3, INHIBIT UP-REGULATION IN PHOSPHORYLATED S10 IN H3 (P-S10H3) AS WELL AS FOS TRANSCRIPTION, A DOWN-STREAM EFFECT OF P-S10H3. DELETING MSK1/2 ALSO INHIBITS THE DEVELOPMENT OF CARRAGEENAN-INDUCED INFLAMMATORY HEAT HYPERALGESIA IN MICE. WE PROPOSE THAT P-S10H3 IS A NOVEL MARKER FOR NOCICEPTIVE PROCESSING IN SSDHN WITH HIGH RELEVANCE TO TRANSCRIPTIONAL CHANGES AND THE DEVELOPMENT OF PROLONGED PAIN. 2017 17 5780 21 SPINAL RNF20-MEDIATED HISTONE H2B MONOUBIQUITYLATION REGULATES MGLUR5 TRANSCRIPTION FOR NEUROPATHIC ALLODYNIA. TO DATE, HISTONE H2B MONOUBIQUITINATION (H2BUB), A MARK ASSOCIATED WITH TRANSCRIPTIONAL ELONGATION AND ONGOING TRANSCRIPTION, HAS NOT BEEN LINKED TO THE DEVELOPMENT OR MAINTENANCE OF NEUROPATHIC PAIN STATES. HERE, USING MALE SPRAGUE DAWLEY RATS, WE DEMONSTRATED SPINAL NERVE LIGATION (SNL) INDUCED BEHAVIORAL ALLODYNIA AND PROVOKED RING FINGER PROTEIN 20 (RNF20)-DEPENDENT H2BUB IN DORSAL HORN. MOREOVER, SNL PROVOKED RNF20-MEDIATED H2BUB PHOSPHORYLATED RNA POLYMERASE II (RNAPII) IN THE PROMOTER FRAGMENTS OF MGLUR5, THEREBY ENHANCING MGLUR5 TRANSCRIPTION/EXPRESSION IN THE DORSAL HORN. CONVERSELY, FOCAL KNOCKDOWN OF SPINAL RNF20 EXPRESSION REVERSED NOT ONLY SNL-INDUCED ALLODYNIA BUT ALSO RNF20/H2BUB/RNAPII PHOSPHORYLATION-ASSOCIATED SPINAL MGLUR5 TRANSCRIPTION/EXPRESSION. NOTABLY, TNF-ALPHA INJECTION INTO NAIVE RATS AND SPECIFIC NEUTRALIZING ANTIBODY INJECTION INTO SNL-INDUCED ALLODYNIA RATS REVEALED THAT TNF-ALPHA-ASSOCIATED ALLODYNIA INVOLVES THE RNF20/H2BUB/RNAPII TRANSCRIPTIONAL AXIS TO UPREGULATE MGLUR5 EXPRESSION IN THE DORSAL HORN. COLLECTIVELY, OUR FINDINGS INDICATED TNF-ALPHA INDUCES RNF20-DRIVED H2B MONOUBIQUITINATION, WHICH FACILITATES PHOSPHORYLATED RNAPII-DEPENDENT MGLUR5 TRANSCRIPTION IN THE DORSAL HORN FOR THE DEVELOPMENT OF NEUROPATHIC ALLODYNIA.SIGNIFICANCE STATEMENT HISTONE H2B MONOUBIQUITINATION (H2BUB), AN EPIGENETIC POST-TRANSLATIONAL MODIFICATION, POSITIVELY CORRELATED WITH GENE EXPRESSION. HERE, TNF-ALPHA PARTICIPATED IN NEUROPATHIC PAIN DEVELOPMENT BY ENHANCING RNF20-MEDIATED H2BUB, WHICH FACILITATES PHOSPHORYLATED RNAPII-DEPENDENT MGLUR5 TRANSCRIPTION IN DORSAL HORN. OUR FINDING POTENTIALLY IDENTIFIED NEUROPATHIC ALLODYNIA PATHOPHYSIOLOGICAL PROCESSES UNDERPINNING ABNORMAL NOCICEPTION PROCESSING AND OPENS A NEW AVENUE FOR THE DEVELOPMENT OF NOVEL ANALGESICS. 2018 18 441 26 ANTISENSE-INDUCED DOWNREGULATION OF MAJOR CIRCADIAN GENES MODULATES THE EXPRESSION OF HISTONE DEACETYLASE-2 (HDAC-2) AND CREB-BINDING PROTEIN (CBP) IN THE MEDIAL SHELL REGION OF NUCLEUS ACCUMBENS OF MICE EXPOSED TO CHRONIC EXCESSIVE ALCOHOL CONSUMPTION. CIRCADIAN GENES IN THE MEDIAL ACCUMBAL SHELL (MNACSH) REGION REGULATE BINGE ALCOHOL CONSUMPTION. HERE, WE INVESTIGATED IF ANTISENSE-INDUCED KNOCKDOWN OF MAJOR CIRCADIAN GENES (PER1, PER2, AND NPAS2) IN THE MNACSH OF MICE EXPOSED TO INTERMITTENT ACCESS TWO-BOTTLE CHOICE (IA2BC) PARADIGM MODULATES THE EXPRESSION OF HISTONE DEACETYLASE-2 (HDAC-2) AND CREB-BINDING PROTEIN (CBP), KEY EPIGENETIC MODIFIERS ASSOCIATED WITH WITHDRAWAL-ASSOCIATED BEHAVIORS SUCH AS ANXIETY. ADULT MALE C57BL/6J MICE (N = 28), SURGICALLY IMPLANTED WITH BILATERAL GUIDE CANNULAS ABOVE THE MNACSH, WERE CHRONICALLY (4 WEEKS) EXPOSED TO ALCOHOL (20% V/V) OR SACCHARIN (0.03%) VIA IA2BC PARADIGM. IN THE FOURTH WEEK, A MIXTURE OF ANTISENSE (AS-ODNS; N = 14/GROUP) OR NONSENSE (NS-ODNS; N = 14/GROUP) OLIGODEOXYNUCLEOTIDES AGAINST CIRCADIAN GENES WERE BILATERALLY INFUSED INTO THE MNACSH. SUBSEQUENTLY, ALCOHOL/SACCHARIN CONSUMPTION AND PREFERENCE WERE MEASURED FOLLOWED BY EUTHANIZATION OF ANIMALS AND VERIFICATION OF MICROINJECTION SITES BY VISUAL INSPECTION AND THE EXPRESSION OF HDAC-2 AND CBP BY USING RT-PCR ALONG WITH THE VERIFICATION OF ANTISENSE-INDUCED DOWNREGULATION OF CIRCADIAN GENES IN THE MNACSH. AS COMPARED WITH NS-ODNS, AS-ODNS INFUSION SIGNIFICANTLY ATTENUATED THE ALCOHOL-INDUCED INCREASE IN HDAC-2 AND REDUCTION IN CBP EXPRESSION IN THE MNACSH ALONG WITH A SIGNIFICANT REDUCTION IN ALCOHOL CONSUMPTION AND PREFERENCE. NO SIGNIFICANT EFFECT WAS OBSERVED ON EITHER SACCHARIN CONSUMPTION OR PREFERENCE. OUR RESULTS SUGGEST THAT CIRCADIAN GENES IN THE MNACSH MAY HAVE A CAUSAL TO PLAY IN MEDIATING EPIGENETIC CHANGES OBSERVED AFTER CHRONIC ALCOHOL CONSUMPTION. 2022 19 3368 26 HISTONE METHYLTRANSFERASE G9A DIMINISHES EXPRESSION OF CANNABINOID CB(1) RECEPTORS IN PRIMARY SENSORY NEURONS IN NEUROPATHIC PAIN. TYPE 1 CANNABINOID RECEPTORS (CB(1)RS) ARE EXPRESSED IN THE DORSAL ROOT GANGLION (DRG) AND CONTRIBUTE TO THE ANALGESIC EFFECT OF CANNABINOIDS. HOWEVER, THE EPIGENETIC MECHANISM REGULATING THE EXPRESSION OF CB(1)RS IN NEUROPATHIC PAIN IS UNKNOWN. G9A (ENCODED BY THE EHMT2 GENE), A HISTONE 3 AT LYSINE 9 METHYLTRANSFERASE, IS A KEY CHROMATIN REGULATOR RESPONSIBLE FOR GENE SILENCING. IN THIS STUDY, WE DETERMINED G9A'S ROLE IN REGULATING CB(1)R EXPRESSION IN THE DRG AND IN CB(1)R-MEDIATED ANALGESIC EFFECTS IN AN ANIMAL MODEL OF NEUROPATHIC PAIN. WE SHOW THAT NERVE INJURY PROFOUNDLY REDUCED MRNA LEVELS OF CB(1)RS BUT INCREASED THE EXPRESSION OF CB(2) RECEPTORS IN THE RAT DRG. CHIP RESULTS INDICATED INCREASED ENRICHMENT OF HISTONE 3 AT LYSINE 9 DIMETHYLATION, A G9A-CATALYZED REPRESSIVE HISTONE MARK, AT THE PROMOTER REGIONS OF THE CB(1)R GENES. G9A INHIBITION IN NERVE-INJURED RATS NOT ONLY UP-REGULATED THE CB(1)R EXPRESSION LEVEL IN THE DRG BUT ALSO POTENTIATED THE ANALGESIC EFFECT OF A CB(1)R AGONIST ON NERVE INJURY-INDUCED PAIN HYPERSENSITIVITY. FURTHERMORE, IN MICE LACKING EHMT2 IN DRG NEURONS, NERVE INJURY FAILED TO REDUCE CB(1)R EXPRESSION IN THE DRG AND TO DECREASE THE ANALGESIC EFFECT OF THE CB(1)R AGONIST. MOREOVER, NERVE INJURY DIMINISHED THE INHIBITORY EFFECT OF THE CB(1)R AGONIST ON SYNAPTIC GLUTAMATE RELEASE FROM PRIMARY AFFERENT NERVES TO SPINAL CORD DORSAL HORN NEURONS IN WT MICE BUT NOT IN MICE LACKING EHMT2 IN DRG NEURONS. OUR FINDINGS REVEAL THAT NERVE INJURY DIMINISHES THE ANALGESIC EFFECT OF CB(1)R AGONISTS THROUGH G9A-MEDIATED CB(1)R DOWN-REGULATION IN PRIMARY SENSORY NEURONS. 2020 20 4499 27 MORPHINE WITHDRAWAL PRODUCES ERK-DEPENDENT AND ERK-INDEPENDENT EPIGENETIC MARKS IN NEURONS OF THE NUCLEUS ACCUMBENS AND LATERAL SEPTUM. EPIGENETIC CHANGES SUCH AS COVALENT MODIFICATIONS OF HISTONE PROTEINS REPRESENT COMPLEX MOLECULAR SIGNATURES THAT PROVIDE A CELLULAR MEMORY OF PREVIOUSLY EXPERIENCED STIMULI WITHOUT IRREVERSIBLE CHANGES OF THE GENETIC CODE. IN THIS STUDY WE SHOW THAT NEW GENE EXPRESSION INDUCED IN VIVO BY MORPHINE WITHDRAWAL OCCURS WITH CONCOMITANT EPIGENETIC MODIFICATIONS IN BRAIN REGIONS CRITICALLY INVOLVED IN DRUG-DEPENDENT BEHAVIORS. WE FOUND THAT NALOXONE-PRECIPITATED WITHDRAWAL, BUT NOT CHRONIC MORPHINE ADMINISTRATION, CAUSED A STRONG INDUCTION OF PHOSPHO-HISTONE H3 IMMUNOREACTIVITY IN THE NUCLEUS ACCUMBENS (NAC) SHELL/CORE AND IN THE LATERAL SEPTUM (LS), A CHANGE THAT WAS ACCOMPANIED BY AUGMENTED H3 ACETYLATION (LYS14) IN NEURONS OF THE NAC SHELL. MORPHINE WITHDRAWAL INDUCED THE PHOSPHORYLATION OF THE EPIGENETIC FACTOR METHYL-CPG-BINDING PROTEIN 2 (MECP2) IN SER421 BOTH IN THE LS AND THE NAC SHELL. THESE EPIGENETIC CHANGES WERE ACCOMPANIED BY THE ACTIVATION OF MEMBERS OF THE ERK PATHWAY AS WELL AS INCREASED EXPRESSION OF THE IMMEDIATE EARLY GENES (IEG) C-FOS AND ACTIVITY-REGULATED CYTOSKELETON-ASSOCIATED PROTEIN (ARC/ARG3.1). USING A PHARMACOLOGICAL APPROACH, WE FOUND THAT H3 PHOSPHORYLATION AND IEG EXPRESSION WERE PARTIALLY DEPENDENT ON ERK ACTIVATION, WHILE MECP2 PHOSPHORYLATION WAS FULLY ERK-INDEPENDENT. THESE FINDINGS PROVIDE NEW IMPORTANT INFORMATION ON THE ROLE OF THE ERK PATHWAY IN THE REGULATION OF EPIGENETIC MARKS AND GENE EXPRESSION THAT MAY CONCUR TO REGULATE IN VIVO THE CELLULAR CHANGES UNDERLYING THE ONSET OF THE OPIOID WITHDRAWAL SYNDROME. 2013