1  6612 113 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
2  5480  49 RESVERATROL REVERSES MORPHINE-INDUCED NEUROINFLAMMATION IN MORPHINE-TOLERANT RATS BY REVERSAL HDAC1 EXPRESSION. BACKGROUND/PURPOSE: WE PREVIOUSLY SHOWED THAT SUBSEQUENT INTRATHECAL (I.T.) INJECTION OF RESVERATROL (30 MUG) SIGNIFICANTLY REVERSES MORPHINE-EVOKED NEUROINFLAMMATION IN MORPHINE-TOLERANT RATS. THE PRESENT STUDY EXAMINED THE UNDERLYING MECHANISM. METHODS: MALE WISTAR RATS WERE IMPLANTED WITH TWO I.T. CATHETERS, ONE OF WHICH WAS CONNECTED TO A MINIOSMOTIC PUMP AND USED FOR MORPHINE (15 MUG/H) OR SALINE INFUSION FOR 120 HOURS. TO EXAMINE THE EFFECTS ON SPINAL CORD EXPRESSION OF HISTONE DEACETYLASE 1 (HDAC1), THE INFLAMMATORY CYTOKINE TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA), AND TNF RECEPTOR (TNFR) 1 AND TNFR2 DURING TOLERANCE INDUCTION, A TAIL-FLICK TEST WAS PERFORMED PRIOR TO INFUSION AND AFTER 24 HOURS, 48 HOURS, 72 HOURS, 96 HOURS, AND 120 HOURS OF INFUSION. RESULTS: RESVERATROL TREATMENT PRIOR TO MORPHINE CHALLENGE RESTORED THE ANTINOCICEPTIVE EFFECT OF MORPHINE IN MORPHINE-TOLERANT RATS AND REVERSED THE MORPHINE INFUSION-INDUCED INCREASE IN HDAC1, TNF-ALPHA, AND TNFR1 EXPRESSION. MOREOVER, CHRONIC MORPHINE INFUSION INCREASED TNFR1-SPECIFIC EXPRESSION IN NEURON IN MORPHINE-TOLERANT RAT SPINAL CORDS, AND THIS EFFECT WAS ALMOST COMPLETELY INHIBITED BY RESVERATROL TREATMENT PRIOR TO MORPHINE CHALLENGE. CONCLUSION: RESVERATROL RESTORES THE ANTINOCICEPTIVE EFFECT OF MORPHINE BY REVERSING MORPHINE INFUSION-INDUCED SPINAL CORD NEUROINFLAMMATION AND INCREASE IN TNFR1 EXPRESSION. THE REVERSAL OF THE MORPHINE-INDUCED INCREASE IN TNFR1 EXPRESSION BY RESVERATROL IS PARTIALLY DUE TO REVERSAL OF THE MORPHINE INFUSION-INDUCED INCREASE IN HDAC1 EXPRESSION. RESVERATROL PRETREATMENT CAN BE USED AS AN ADJUVANT IN CLINICAL PAIN MANAGEMENT FOR PATIENTS WHO NEED LONG-TERM MORPHINE TREATMENT OR WITH NEUROPATHIC PAIN.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               
3  3868  41 JMJD6 EXERTS FUNCTION IN NEUROPATHIC PAIN BY REGULATING NF?KAPPAB FOLLOWING PERIPHERAL NERVE INJURY IN RATS. TREATMENT OF NEUROPATHIC PAIN (NPP) CONTINUES TO BE A MAJOR CHALLENGE, AND THE UNDERLYING MECHANISMS REMAIN TO BE ELUCIDATED. PREVIOUS STUDIES HAVE DEMONSTRATED THAT HISTONE METHYLATION IS IMPORTANT IN SYNAPTIC PLASTICITY OF THE NERVOUS SYSTEM AND MAY AFFECT NUCLEAR FACTOR?KAPPAB (NF?KAPPAB) SIGNALING THROUGH EPIGENETIC MECHANISMS. THE PRESENT STUDY AIMED TO INVESTIGATE THE ROLE OF JUMONJI C DOMAIN 6 (JMJD6), A HISTONE DEMETHYLASE, IN A CHRONIC CONSTRICTION INJURY (CCI) MODEL OF NPP. ON THE THIRD DAY POST?CCI SURGERY, A JMJD6 OVEREXPRESSING LENTIVIRAL VECTOR (LV?JMJD6) WAS INTRATHECALLY INJECTED IN THE RATS. MECHANICAL WITHDRAWAL THRESHOLD AND THERMAL WITHDRAWAL LATENCY WERE ASSESSED PRIOR SURGERY AND ON DAYS 3, 7, 10 AND 14 POST?CCI. THE RESULTS SHOWED THAT INTRATHECAL INJECTION WITH THE LV?JMJD6 ATTENUATED CCI?INDUCED PAIN FACILITATION. THE EXPRESSION OF JMJD6 WAS LOWER FOLLOWING CCI SURGERY, AND ITS EXPRESSION WAS SIGNIFICANTLY INCREASED FOLLOWING INTRATHECAL INJECTION WITH LV?JMJD6, COMPARED WITH LEVELS IN NORMAL SALINE (NS)? AND NEGATIVE CONTROL LENTIVIRAL VECTOR (NC)?TREATED RATS. THE EXPRESSION OF SPINAL NF?KAPPAB PHOSPHORYLATED (P?)P65 SUBUNIT AND ITS DOWNSTREAM PAIN?ASSOCIATED EFFECTORS, INCLUDING INTERLEUKIN 1BETA (IL?1BETA), TUMOR NECROSIS FACTOR?ALPHA (TNF?ALPHA) AND VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF), WERE INCREASED FOLLOWING CCI SURGERY. INTRATHECAL INJECTION WITH LV?JMJD6 SUPPRESSED ACTIVATION OF THE P?P65 SUBUNIT IN CCI RATS. IN ADDITION, EXPRESSION LEVELS OF ITS DOWNSTREAM EFFECTORS IL?1BETA, TNF?ALPHA AND VEGF WERE ATTENUATED BY INTRATHECAL TREATMENT WITH LV?JMJD6, COMPARED WITH THOSE IN THE NS? AND NC?TREATED CCI RATS. FURTHERMORE, THE JMJD6? AND P65?IMMUNOREACTIVE CELLS OVERLAPPED IN THE SPINAL DORSAL HORN, HOWEVER, CO?IMMUNOPRECIPITATION SHOWED THAT JMJD6 AND THE NF?KAPPAB P65 SUBUNIT DID NOT DIRECTLY INTERACT, INDICATING OTHER FUNCTIONAL CONNECTIONS MAY EXIST BETWEEN THESE FACTORS FOLLOWING CCI SURGERY. COLLECTIVELY, THESE FINDINGS INDICATED AN IMPORTANT MECHANISM UNDERLYING THE PATHOGENESIS OF NPP. JMJD6 MAY EXERT ITS THERAPEUTIC FUNCTION IN NPP BY REGULATING NF?KAPPAB FOLLOWING CCI.	2018	
                                                                                                                                                                                                                                                                                         
4  4579  30 N(6)-METHYLADENOSINE METHYLASE METTL3 CONTRIBUTES TO NEUROPATHIC PAIN BY EPIGENETIC SILENCING OF MU OPIOID RECEPTOR. WE AIMED AT EXPLORING THE ROLE AND MECHANISM OF METTL3-MEDIATED M(6)A MODIFICATION IN NEUROPATHIC PAIN. MALE SPRAGUE-DAWLEY RATS WERE RANDOMLY DIVIDED INTO FOUR GROUPS: SHAM OPERATION GROUP (SHAM GROUP), CHRONIC CONSTRICTION INJURY (CCI) OF THE SCIATIC NERVE MODEL GROUP (NPP GROUP), INTRATHECAL INJECTION OF VIRUS DOWN-REGULATED METTL3 + CCI MODEL GROUP (M3 + NPP GROUP) AND INTRATHECAL INJECTION OF NEGATIVE CONTROL VIRUS + CCI MODEL GROUP (SCR + NPP GROUP). THE M3 + NPP GROUP AND THE SCR + NPP GROUP WERE INTRATHECALLY INJECTED WITH VIRUS NINETEEN DAYS BEFORE OPERATION. THE PAW WITHDRAWAL MECHANICAL THRESHOLDS AND PAW WITHDRAWAL LATENCY WERE RESPECTIVELY RECORDED ONE DAY BEFORE OPERATION, THREE DAYS, FIVE DAYS AND SEVEN DAYS AFTER OPERATION. THE RATS WERE SACRIFICED ON THE SEVENTH DAY AFTER OPERATION, AND THEIR SPINAL CORD TISSUES WERE TAKEN. THE FROZEN SECTIONS OF RATS WERE PERFORMED TO OBSERVE THE EXPRESSION OF GREEN FLUORESCENT PROTEIN OF THE VIRUS. THE METHYLATION LEVEL OF RNA, THE PROTEIN EXPRESSION OF M(6)A-RELATED ENZYME (METTL3) AND MU OPIOID RECEPTOR (MOR) IN SPINAL CORD TISSUES OF THE FOUR GROUPS WERE MEASURED. DOWNREGULATION OF METTL3 HAD NO EFFECT ON THE OVERALL METHYLATION LEVEL OF THE SPINAL CORD, BUT IT COULD REGULATE THE METHYLATION LEVEL OF THE OPRM1 GENE RNA ENCODING MOR, PARTIALLY RESTORE THE EXPRESSION OF MOR, AND RELIEVE PAIN IN RATS. IN THE PROCESS OF NPP, METTL3 MAY INHIBIT THE EXPRESSION OF MOR BY REGULATING THE METHYLATION LEVEL OF OPRM1 GENE RNA ENCODING MOR, AND ULTIMATELY PROMOTE THE OCCURRENCE AND DEVELOPMENT OF NPP.	2023	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
5  2452  41 EPIGENETIC SUPPRESSION OF POTASSIUM-CHLORIDE CO-TRANSPORTER 2 EXPRESSION IN INFLAMMATORY PAIN INDUCED BY COMPLETE FREUND'S ADJUVANT (CFA). BACKGROUND: MULTIPLE MECHANISMS CONTRIBUTE TO THE STIMULUS-EVOKED PAIN HYPERSENSITIVITY THAT MAY BE EXPERIENCED AFTER PERIPHERAL INFLAMMATION. PERSISTENT PATHOLOGICAL STIMULI IN MANY PAIN CONDITIONS AFFECT THE EXPRESSION OF CERTAIN GENES THROUGH EPIGENETIC ALTERNATIONS. THE MAIN PURPOSE OF OUR STUDY WAS TO INVESTIGATE THE ROLE OF EPIGENETIC MODIFICATION ON POTASSIUM-CHLORIDE CO-TRANSPORTER 2 (KCC2) GENE EXPRESSION IN THE PERSISTENCE OF INFLAMMATORY PAIN. METHODS: PERSISTENT INFLAMMATORY PAIN WAS INDUCED THROUGH THE INJECTION OF COMPLETE FREUND'S ADJUVANT (CFA) IN THE LEFT HIND PAW OF RATS. ACETYL-HISTONE H3 AND H4 LEVEL WAS DETERMINED BY CHROMATIN IMMUNOPRECIPITATION IN THE SPINAL DORSAL HORN. PAIN BEHAVIOUR AND INHIBITORY SYNAPTIC FUNCTION OF SPINAL CORD WERE DETERMINED BEFORE AND AFTER CFA INJECTION. KCC2 EXPRESSION WAS DETERMINED BY REAL TIME RT-PCR AND WESTERN BLOT. INTRATHECAL KCC2 SIRNA (2 MUG PER 10 MUL PER RAT) OR HDAC INHIBITOR (10 MUG PER 10 MUL PER RAT) WAS INJECTED ONCE DAILY FOR 3 DAYS BEFORE CFA INJECTION. RESULTS: PERSISTENT INFLAMMATORY PAIN EPIGENETICALLY SUPPRESSED KCC2 EXPRESSION THROUGH HISTONE DEACETYLASE (HDAC)-MEDIATED HISTONE HYPOACETYLATION, RESULTING IN DECREASED INHIBITORY SIGNALLING EFFICACY. KCC2 KNOCK-DOWN CAUSED BY INTRATHECAL ADMINISTRATION OF KCC2 SIRNA IN NAIVE RATS REDUCED KCC2 EXPRESSION IN THE SPINAL CORD, LEADING TO SENSITIZED PAIN BEHAVIOURS AND IMPAIRED INHIBITORY SYNAPTIC TRANSMISSION IN THEIR SPINAL CORDS. MOREOVER, INTRATHECAL HDAC INHIBITOR INJECTION IN CFA RATS INCREASED KCC2 EXPRESSION, PARTIALLY RESTORING THE SPINAL INHIBITORY SYNAPTIC TRANSMISSION AND RELIEVING THE SENSITIZED PAIN BEHAVIOUR. CONCLUSION: THESE FINDINGS SUGGEST THAT THE TRANSCRIPTION OF SPINAL KCC2 IS REGULATED BY HISTONE ACETYLATION EPIGENETICALLY FOLLOWING CFA. SIGNIFICANCE: PERSISTENT PAIN SUPPRESSES KCC2 EXPRESSION THROUGH HDAC-MEDIATED HISTONE HYPOACETYLATION AND CONSEQUENTLY IMPAIRS THE INHIBITORY FUNCTION OF INHIBITORY INTERNEURONS. DRUGS SUCH AS HDAC INHIBITORS THAT SUPPRESS THE INFLUENCES OF PERSISTENT PAIN ON THE EXPRESSION OF KCC2 MAY SERVE AS A NOVEL ANALGESIC.	2017	
                                                                                                                                                                                                                                                                                        
6  3810  39 INTRATHECAL 5-AZACYTIDINE INHIBITS GLOBAL DNA METHYLATION AND METHYL- CPG-BINDING PROTEIN 2 EXPRESSION AND ALLEVIATES NEUROPATHIC PAIN IN RATS FOLLOWING CHRONIC CONSTRICTION INJURY. THE PATHOGENESIS OF NEUROPATHIC PAIN REMAINS LARGELY UNKNOWN. EPIGENETIC MECHANISMS MAY PLAY A MAJOR ROLE IN REGULATING EXPRESSION OF PRO- OR ANTINOCICEPTIVE GENES. DNA METHYLATION IS A MAJOR EPIGENETIC MECHANISM IN VERTEBRATES, AND METHYL- CPG-BINDING PROTEIN 2 (MECP2) IS DIRECTLY INVOLVED IN METHYLATION-MEDIATED GENE SILENCING. TO DETERMINE HOW CHANGES IN GLOBAL DNA METHYLATION AND MECP2 EXPRESSION OCCUR FOLLOWING CHRONIC CONSTRICTION INJURY (CCI) AND HOW REPRESSION OF DNA METHYLATION AFFECTS THESE CHANGES AND ATTENUATES NEUROPATHIC PAIN, WE USED INTRATHECAL 5-AZACYTIDINE, A DNA METHYLTRANSFERASE INHIBITOR, IN CCI RATS. RATS RECEIVED 0.9% SALINE OR 5-AZACYTIDINE (10MUMOL.D(-1)) VIA SPINAL INJECTION ONCE DAILY FROM DAY 3 TO DAY 14 AFTER CCI SURGERY. GLOBAL DNA METHYLATION AND MECP2 EXPRESSION INCREASED IN THE SPINAL CORD IN CCI RATS ON DAY 14 AFTER CCI SURGERY. MECHANICAL ALLODYNIA AND THERMAL HYPERALGESIA INDUCED BY CCI WERE ATTENUATED BY INTRATHECAL 5-AZACYTIDINE FROM DAY 5 TO DAY 14 AFTER CCI SURGERY. THE INCREASES IN GLOBAL DNA METHYLATION AND MECP2 EXPRESSION IN THE SPINAL CORD IN CCI RATS WERE ALSO SIGNIFICANTLY INHIBITED BY INTRATHECAL 5-AZACYTIDINE. THESE RESULTS DEMONSTRATE THAT INCREASED GLOBAL DNA METHYLATION AND MECP2 EXPRESSION IN THE SPINAL CORD AFTER NERVE DAMAGE MAY PLAY AN IMPORTANT ROLE IN NEUROPATHIC PAIN. 5-AZACYTIDINE SHOWS POTENTIAL FOR TREATING NEUROPATHIC PAIN.	2011	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
7  1800  32 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
8  1320  31 DEMETHYLATION REGULATION OF BDNF GENE EXPRESSION IN DORSAL ROOT GANGLION NEURONS IS IMPLICATED IN OPIOID-INDUCED PAIN HYPERSENSITIVITY IN RATS. REPEATED ADMINISTRATION OF MORPHINE MAY RESULT IN OPIOID-INDUCED HYPERSENSITIVITY (OIH), WHICH INVOLVES ALTERED EXPRESSION OF NUMEROUS GENES, INCLUDING BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IN DORSAL ROOT GANGLION (DRG) NEURONS. YET, IT REMAINS UNCLEAR HOW BDNF EXPRESSION IS INCREASED IN DRG NEURONS AFTER REPEATED MORPHINE TREATMENT. DNA METHYLATION IS AN IMPORTANT MECHANISM OF EPIGENETIC CONTROL OF GENE EXPRESSION. IN THE CURRENT STUDY, WE HYPOTHESIZED THAT THE DEMETHYLATION REGULATION OF CERTAIN BDNF GENE PROMOTERS IN DRG NEURONS MAY CONTRIBUTE TO THE DEVELOPMENT OF OIH. REAL-TIME RT-PCR WAS USED TO ASSESS CHANGES IN THE MRNA TRANSCRIPTION LEVELS OF MAJOR BDNF EXONS INCLUDING EXON I, II, IV, VI, AS WELL AS TOTAL BDNF MRNA IN DRGS FROM RATS AFTER REPEATED MORPHINE ADMINISTRATION. THE LEVELS OF EXON IV AND TOTAL BDNF MRNA WERE SIGNIFICANTLY UPREGULATED BY REPEATED MORPHINE ADMINISTRATION, AS COMPARED TO THAT IN SALINE CONTROL GROUP. FURTHER, ELISA ARRAY AND IMMUNOCYTOCHEMISTRY STUDY REVEALED A ROBUST UPREGULATION OF BDNF PROTEIN EXPRESSION IN DRG NEURONS AFTER REPEATED MORPHINE EXPOSURE. CORRESPONDINGLY, THE METHYLATION LEVELS OF BDNF EXON IV PROMOTER SHOWED A SIGNIFICANT DOWNREGULATION BY MORPHINE TREATMENT. IMPORTANTLY, INTRATHECAL ADMINISTRATION OF A BDNF ANTIBODY, BUT NOT CONTROL IGG, SIGNIFICANTLY INHIBITED MECHANICAL HYPERSENSITIVITY THAT DEVELOPED IN RATS AFTER REPEATED MORPHINE TREATMENT. CONVERSELY, INTRATHECAL ADMINISTRATION OF AN INHIBITOR OF DNA METHYLATION, 5-AZA-2'-DEOXYCYTIDINE (5-AZA-DC) MARKEDLY UPREGULATED THE BDNF PROTEIN EXPRESSION IN DRG NEURONS AND ENHANCED THE MECHANICAL ALLODYNIA AFTER REPEATED MORPHINE EXPOSURE. TOGETHER, OUR FINDINGS SUGGEST THAT DEMETHYLATION REGULATION OF BDNF GENE PROMOTER MAY BE IMPLICATED IN THE DEVELOPMENT OF OIH THROUGH EPIGENETIC CONTROL OF BDNF EXPRESSION IN DRG NEURONS.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
9  2300  40 EPIGENETIC REGULATION OF BDNF EXPRESSION IN THE PRIMARY SENSORY NEURONS AFTER PERIPHERAL NERVE INJURY: IMPLICATIONS IN THE DEVELOPMENT OF NEUROPATHIC PAIN. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IS KNOWN TO BE UP-REGULATED IN THE DORSAL ROOT GANGLION (DRG) AFTER PERIPHERAL NERVE INJURY, AND TO CONTRIBUTE TO NEUROPATHIC PAIN. HERE, WE FOUND THAT THERMAL HYPERALGESIA AND MECHANICAL ALLODYNIA AT DAY 7 POST-INJURY WERE INHIBITED ONLY WHEN ANTI-BDNF ANTIBODY WAS INTRATHECALLY ADMINISTRATED AT DAY 2 POST-INJURY. CONSISTENT WITH BEHAVIORAL RESULTS, WESTERN BLOT ANALYSIS SHOWED THAT THE EXPRESSION LEVELS OF BDNF PROTEIN IN THE SPINAL DORSAL HORN WERE MARKEDLY INDUCED DURING EARLY STAGE POST-INJURY. MOREOVER, THE MAXIMAL INCREASE IN BDNF MRNA EXPRESSION IN THE DRG WAS OBSERVED AT DAY 1 POST-INJURY, AND SIGNIFICANTLY ELEVATED LEVELS WERE SUSTAINED FOR AT LEAST 14 DAYS. FOUR OF FIVE BDNF MRNA TRANSCRIPTS WERE UP-REGULATED AFTER NERVE INJURY, AND THE MOST INDUCIBLE TRANSCRIPT WAS EXON I. USING A CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY, WE FOUND THAT NERVE INJURY PROMOTES HISTONE H3 AND H4 ACETYLATION, TRANSCRIPTIONALLY ACTIVE MODIFICATIONS, AT BDNF PROMOTER I AT DAY 1 POST-INJURY, AND THE LEVELS OF HISTONE ACETYLATION REMAIN ELEVATED FOR AT LEAST 7 DAYS. TAKEN TOGETHER, OUR FINDINGS SUGGEST THAT AN INITIAL INCREASE IN BDNF EXON I EXPRESSION CONTROLLED BY EPIGENETIC MECHANISMS MIGHT HAVE A CRUCIAL ROLE IN THE DEVELOPMENT OF NEUROPATHIC PAIN.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
10  3331  39 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	
                                                                                                                                                                                                                                               
11  4397  36 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	
                                                                                                                                                                                                                                                                                      
12  3785  27 INTERGENERATIONAL EFFECTS OF PRE-PREGNANCY CHRONIC LIPOPOLYSACCHARIDE FROM PORPHYROMONAS GINGIVALIS ON THE LEARNING, MEMORY AND SEIZURE SUSCEPTIBILITY OF OFFSPRING. OBJECTIVE: THE AIM OF THIS STUDY WAS TO INVESTIGATE THE EFFECTS OF PRE-PREGNANCY CHRONIC EXPOSURE TO PORPHYROMONAS GINGIVALIS LPS (PG LPS) ON THE LEARNING, MEMORY, AND SEIZURE SUSCEPTIBILITY OF THE OFFSPRING. DESIGN: TO ACHIEVE PERIODONTITIS, PG LPS (5 MUG/KG) WAS INJECTED INTO THE GINGIVAL OF FIVE FEMALE RATS EVERY 48 H FOR THREE WEEKS. FIVE CONTROL FEMALE RATS RECEIVED SALINE (0.9 %) AND FIVE FEMALE WERE KEPT INTACT. THE CONCENTRATIONS OF TNF-ALPHA AND IL-6 WERE MEASURED IN THE BLOOD SAMPLES. ONE WEEK AFTER THE FINAL INJECTION, FEMALES WERE MATED WITH INTACT MALES. FOLLOWING BIRTH AND WEANING, TWO MALE AND TWO FEMALE OFFSPRING WERE RANDOMLY SELECTED FROM EACH MOTHER, AND NEW GROUPS OF MALE AND FEMALE OFFSPRING WERE DEFINED FOR BEHAVIORAL ASSESSMENTS. MORRIS WATER MAZE WAS USED TO EVALUATE SPATIAL MEMORY, SHUTTLE BOX WAS USED TO INVESTIGATE AVOIDANCE MEMORY AND A PENTYLENETETRAZOLE-INDUCED SEIZURE WAS USED TO EVALUATE SEIZURE SUSCEPTIBILITY IN THE OFFSPRING. RESULTS: SPATIAL LEARNING AND AVOIDANCE MEMORY SIGNIFICANTLY DECREASED IN BOTH MALE AND FEMALE OFFSPRING OF PG LPS-EXPOSED FEMALE RATS, COMPARED TO THE CONTROL OFFSPRING. LATENCY TO REACH SEIZURE STAGES 1 AND 2 SIGNIFICANTLY INCREASED IN THE MALE OFFSPRING, BUT NOT THE FEMALE OFFSPRING OF PG LPS-EXPOSED FEMALE, COMPARED TO THE CONTROL OFFSPRING. HOWEVER, NO SIGNIFICANT DIFFERENCE WAS FOUND IN LATENCY TO REACH STAGES 3-5. CONCLUSION: PRE-PREGNANCY EXPOSURE TO PG LPS COULD AFFECT SOME BEHAVIORAL FUNCTIONS IN BOTH MALE AND FEMALE OFFSPRING INTERGENERATIONALLY.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
13  4913  34 PAIN MODULATION IN WAG/RIJ EPILEPTIC RATS (A GENETIC MODEL OF ABSENCE EPILEPSY): EFFECTS OF BIOLOGICAL AND PHARMACOLOGICAL HISTONE DEACETYLASE INHIBITORS. EPIGENETIC MECHANISMS ARE INVOLVED IN EPILEPSY AND CHRONIC PAIN DEVELOPMENT. ABOUT THAT, WE STUDIED THE EFFECTS OF THE NATURAL HISTONE DEACETYLASE (HDAC) INHIBITOR SODIUM BUTYRATE (BUT) IN COMPARISON WITH VALPROIC ACID (VPA) IN A VALIDATED GENETIC MODEL OF GENERALIZED ABSENCE EPILEPSY AND EPILEPTOGENESIS. WAG/RIJ RATS WERE TREATED WITH BUT (30 MG/KG), VPA (300 MG/KG), AND THEIR COMBINATION (BUT + VPA) DAILY PER OS FOR 6 MONTHS. RATS WERE SUBJECTED AT RANDALL-SELITTO, VON FREY, HOT PLATE, AND TAIL FLICK TESTS AFTER 1, 3, AND 6 MONTHS OF TREATMENT TO EVALUATE HYPERSENSITIVITY TO NOXIOUS AND NON-NOXIUOUS STIMULI. MOREOVER, PPAR-GAMMA (G3335 1 MG/KG), GABA-B (CGP35348 80 MG/KG), AND OPIOID (NALOXONE 1 MG/KG) RECEPTOR ANTAGONISTS WERE ADMINISTRATED TO INVESTIGATE THE POSSIBLE MECHANISMS INVOLVED IN ANALGESIC ACTIVITY. THE EXPRESSION OF NFKB, GLUTATHIONE REDUCTASE, AND PROTEIN OXIDATION (CARBONYLATION) WAS ALSO EVALUATED BY WESTERN BLOT ANALYSIS. WAG/RIJ RATS SHOWED AN ALTERED PAIN THRESHOLD THROUGHOUT THE STUDY (P < 0.001). BUT AND BUT + VPA TREATMENT REDUCED HYPERSENSITIVITY (P < 0.01). VPA WAS SIGNIFICANTLY EFFECTIVE ONLY AFTER 1 MONTH (P < 0.01). ALL THE THREE RECEPTORS ARE INVOLVED IN BUT + VPA EFFECTS (P < 0.001). BUT AND BUT + VPA DECREASED THE EXPRESSION OF NFKB AND ENHANCED GLUTATHIONE REDUCTASE (P < 0.01); PROTEIN OXIDATION (CARBONYLATION) WAS REDUCED (P < 0.01). NO EFFECT WAS REPORTED WITH VPA. IN CONCLUSION BUT, ALONE OR IN COADMINISTRATION WITH VPA, IS A VALUABLE CANDIDATE FOR MANAGING THE EPILEPSY-RELATED PERSISTENT PAIN.	2020	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
14  2364  35 EPIGENETIC REGULATION OF SPINAL CORD GENE EXPRESSION CONTROLS OPIOID-INDUCED HYPERALGESIA. BACKGROUND: THE LONG TERM USE OF OPIOIDS FOR THE TREATMENT OF PAIN LEADS TO A GROUP OF MALADAPTATIONS WHICH INCLUDES OPIOID-INDUCED HYPERALGESIA (OIH). OIH TYPICALLY RESOLVES WITHIN FEW DAYS AFTER CESSATION OF MORPHINE TREATMENT IN MICE BUT IS PROLONGED FOR WEEKS IF HISTONE DEACETYLASE (HDAC) ACTIVITY IS INHIBITED DURING OPIOID TREATMENT. THE PRESENT WORK SEEKS TO IDENTIFY GENE TARGETS SUPPORTING THE EPIGENETIC EFFECTS RESPONSIBLE FOR OIH PROLONGATION. RESULTS: MICE WERE TREATED WITH MORPHINE ACCORDING TO AN ASCENDING DOSE PROTOCOL. SOME MICE ALSO RECEIVED THE SELECTIVE HDAC INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) ADDITIONALLY. CHRONIC MORPHINE TREATMENT WITH SIMULTANEOUS HDAC INHIBITION ENHANCED OIH, AND SEVERAL SPINAL CORD GENES WERE UP-REGULATED. THE EXPRESSION OF BDNF (BRAIN-DERIVED NEUROTROPHIC FACTOR) AND PDYN (PRODYNORPHIN) WERE MOST CLOSELY RELATED TO THE OBSERVED BEHAVIORAL CHANGES. CHIP (CHROMATIN IMMUOPRECIPATION) ASSAYS DEMONSTRATED THAT PROMOTER REGIONS OF PDYN AND BDNF WERE STRONGLY ASSOCIATED WITH ACEH3K9 (ACETYLATED HISTONE H3 LYSINE9) AFTER MORPHINE AND SAHA TREATMENT. FURTHERMORE, MORPHINE TREATMENT CAUSED AN INCREASE IN SPINAL BDNF AND DYNORPHIN LEVELS, AND THESE LEVELS WERE FURTHER INCREASED IN SAHA TREATED MICE. THE SELECTIVE TRKB (TROPOMYOSIN-RECEPTOR-KINASE) ANTAGONIST ANA-12 REDUCED OIH WHEN GIVEN ONE OR SEVEN DAYS AFTER CESSATION OF MORPHINE. TREATMENT WITH THE SELECTIVE KAPPA OPIOID RECEPTOR ANTAGONIST NOR-BNI ALSO REDUCED ESTABLISHED OIH. THE CO-ADMINISTRATION OF EITHER RECEPTOR ANTAGONIST AGENT DAILY WITH MORPHINE RESULTED IN ATTENUATION OF HYPERALGESIA PRESENT ONE DAY AFTER CESSATION OF TREATMENT. ADDITIONALLY, REPEATED MORPHINE EXPOSURE INDUCED A RISE IN BDNF EXPRESSION THAT WAS ASSOCIATED WITH AN INCREASED NUMBER OF BDNF+ CELLS IN THE SPINAL CORD DORSAL HORN, SHOWING STRONG CO-LOCALIZATION WITH ACEH3K9 IN NEURONAL CELLS. LASTLY, SPINAL APPLICATION OF LOW DOSE BDNF OR DYNORPHIN A AFTER RESOLUTION OF OIH PRODUCED MECHANICAL HYPERSENSITIVITY, WITH NO EFFECT IN CONTROLS. CONCLUSIONS: THE PRESENT STUDY IDENTIFIED TWO GENES WHOSE EXPRESSION IS REGULATED BY EPIGENETIC MECHANISMS DURING MORPHINE EXPOSURE. TREATMENTS AIMED AT PREVENTING THE ACETYLATION OF HISTONES OR BLOCKING BDNF AND DYNORPHIN SIGNALING MAY REDUCE OIH AND IMPROVE LONG-TERM PAIN USING OPIOIDS.	2014	
                                                                                                                     
15  2363  38 EPIGENETIC REGULATION OF SPINAL CORD GENE EXPRESSION CONTRIBUTES TO ENHANCED POSTOPERATIVE PAIN AND ANALGESIC TOLERANCE SUBSEQUENT TO CONTINUOUS OPIOID EXPOSURE. BACKGROUND: OPIOIDS HAVE BECOME THE MAINSTAY FOR TREATMENT OF MODERATE TO SEVERE PAIN AND ARE COMMONLY USED TO TREAT SURGICAL PAIN. WHILE OPIOID ADMINISTRATION HAS BEEN SHOWN TO CAUSE OPIOID-INDUCED HYPERALGESIA AND TOLERANCE, INTERACTIONS BETWEEN OPIOID ADMINISTRATION AND SURGERY WITH RESPECT TO THESE PROBLEMATIC ADAPTATIONS HAVE SCARCELY BEEN ADDRESSED. ACCUMULATING EVIDENCE SUGGESTS OPIOIDS AND NOCICEPTIVE SIGNALING MAY CONVERGE ON EPIGENETIC MECHANISMS IN SPINAL CORD TO ENHANCE OR PROLONG NEUROPLASTIC CHANGES. EPIGENETIC REGULATION OF BDNF (BRAIN-DERIVED NEUROTROPHIC FACTOR) AND PDYN (PRODYNORPHIN) GENES MAY BE INVOLVED. RESULTS: FOUR DAYS OF ASCENDING DOSES OF MORPHINE TREATMENT CAUSED OPIOID-INDUCED HYPERALGESIA AND REDUCED OPIOID ANALGESIC EFFICACY IN MICE. BOTH OPIOID-INDUCED HYPERALGESIA AND THE REDUCED OPIOID ANALGESIC EFFICACY WERE ENHANCED IN MICE THAT RECEIVED HINDPAW INCISIONS. THE EXPRESSION OF BDNF AND PDYN (QPCR) WAS INCREASED AFTER MORPHINE TREATMENT AND INCISION. CHROMATIN IMMUNOPRECIPITATION ASSAYS DEMONSTRATED THAT THE PDYN AND BDNF PROMOTERS WERE MORE STRONGLY ASSOCIATED WITH ACETYLATED H3K9 AFTER MORPHINE PLUS INCISION THAN IN THE MORPHINE OR INCISION ALONE GROUPS. SELECTIVE TROPOMYOSIN-RELATED KINASE B (ANA-12) AND KAPPA-OPIOID RECEPTOR (NOR-BINALTORPHIMINE) ANTAGONISTS WERE ADMINISTERED INTRATHECALLY, BOTH REDUCED HYPERALGESIA ONE OR THREE DAYS AFTER SURGERY. ADMINISTRATION OF ANA-12 OR NOR-BINALTORPHIMINE ATTENUATED THE DECREASED MORPHINE ANALGESIC EFFICACY ON DAY 1, BUT ONLY NOR-BINALTORPHIMINE WAS EFFECTIVE ON DAY 3 AFTER INCISION IN OPIOID-EXPOSED GROUP. COADMINISTRATION OF HISTONE ACETYLTRANSFERASE INHIBITOR ANACARDIC ACID DAILY WITH MORPHINE BLOCKED THE DEVELOPMENT OF OPIOID-INDUCED HYPERALGESIA AND ATTENUATED INCISION-ENHANCED HYPERALGESIA IN MORPHINE-TREATED MICE. ANACARDIC ACID HAD SIMILAR EFFECTS ON ANALGESIC TOLERANCE, SHOWING THE INVOLVEMENT OF HISTONE ACETYLATION IN THE INTERACTIONS DETECTED. CONCLUSIONS: SPINAL EPIGENETIC CHANGES INVOLVING BDNF AND PDYN MAY CONTRIBUTE TO THE ENHANCED POSTOPERATIVE NOCICEPTIVE SENSITIZATION AND ANALGESIC TOLERANCE OBSERVED AFTER CONTINUOUS OPIOID EXPOSURE. TREATMENTS BLOCKING THE EPIGENETICALLY MEDIATED UP-REGULATION OF THESE GENES OR ADMINISTRATION OF TRKB OR KAPPA-OPIOID RECEPTOR ANTAGONISTS MAY IMPROVE THE CLINICAL UTILITY OF OPIOIDS, PARTICULARLY AFTER SURGERY.	2016	

16  5657  37 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  2365  34 EPIGENETIC REGULATION OF SPINAL CXCR2 SIGNALING IN INCISIONAL HYPERSENSITIVITY IN MICE. BACKGROUND: THE REGULATION OF GENE EXPRESSION IN NOCICEPTIVE PATHWAYS CONTRIBUTES TO THE INDUCTION AND MAINTENANCE OF PAIN SENSITIZATION. HISTONE ACETYLATION IS A KEY EPIGENETIC MECHANISM CONTROLLING CHROMATIN STRUCTURE AND GENE EXPRESSION. CHEMOKINE CC MOTIF RECEPTOR 2 (CXCR2) IS A PROINFLAMMATORY RECEPTOR IMPLICATED IN NEUROPATHIC AND INFLAMMATORY PAIN AND IS KNOWN TO BE REGULATED BY HISTONE ACETYLATION IN SOME SETTINGS. THE AUTHORS SOUGHT TO INVESTIGATE THE ROLE OF HISTONE ACETYLATION ON SPINAL CXCR2 SIGNALING AFTER INCISION. METHODS: GROUPS OF 5-8 MICE UNDERWENT HIND PAW INCISION. SUBEROYLANILIDE HYDROXAMIC ACID AND ANACARDIC ACID WERE USED TO INHIBIT HISTONE DEACETYLASE AND HISTONE ACETYLTRANSFERASE, RESPECTIVELY. BEHAVIORAL MEASURES OF THERMAL AND MECHANICAL SENSITIZATION AS WELL AS HYPERALGESIC PRIMING WERE USED. BOTH MESSAGE RNA QUANTIFICATION AND CHROMATIN IMMUNOPRECIPITATION ANALYSIS WERE USED TO STUDY THE REGULATION OF CXCR2 AND LIGAND EXPRESSION. FINALLY, THE SELECTIVE CXCR2 ANTAGONIST SB225002 WAS ADMINISTERED INTRATHECALLY TO REVEAL THE FUNCTION OF SPINAL CXCR2 RECEPTORS AFTER HIND PAW INCISION. RESULTS: SUBEROYLANILIDE HYDROXAMIC ACID SIGNIFICANTLY EXACERBATED MECHANICAL SENSITIZATION AFTER INCISION. CONVERSELY, ANACARDIC ACID REDUCED INCISIONAL SENSITIZATION AND ALSO ATTENUATED INCISION-INDUCED HYPERALGESIC PRIMING. OVERALL, ACETYLATED HISTONE H3 AT LYSINE 9 WAS INCREASED IN SPINAL CORD TISSUES AFTER INCISION, AND ENHANCED ASSOCIATION OF ACETYLATED HISTONE H3 AT LYSINE 9 WITH THE PROMOTER REGIONS OF CXCR2 AND KERATINOCYTE-DERIVED CHEMOKINE (CXCL1) WAS OBSERVED AS WELL. BLOCKING CXCR2 REVERSED MECHANICAL HYPERSENSITIVITY AFTER HIND PAW INCISION. CONCLUSIONS: HISTONE MODIFICATION IS AN IMPORTANT EPIGENETIC MECHANISM REGULATING INCISION-INDUCED NOCICEPTIVE SENSITIZATION. THE SPINAL CXCR2 SIGNALING PATHWAY IS ONE EPIGENETICALLY REGULATED PATHWAY CONTROLLING EARLY AND LATENT SENSITIZATION AFTER INCISION.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       
18  5328  35 PULSED RADIOFREQUENCY ATTENUATES COMPLETE FREUND'S ADJUVANT-INDUCED EPIGENETIC SUPPRESSION OF POTASSIUM CHLORIDE COTRANSPORTER 2 EXPRESSION. BACKGROUND: PULSED RADIOFREQUENCY (PRF) TREATMENT OFFERS PAIN RELIEF FOR PATIENTS SUFFERING FROM CHRONIC PAIN WHO DO NOT RESPOND WELL TO CONVENTIONAL TREATMENTS. WE TESTED WHETHER PRF TREATMENT ATTENUATED COMPLETE FREUND'S ADJUVANT (CFA)-INDUCED INFLAMMATORY PAIN. EPIGENETIC MODIFICATION OF POTASSIUM-CHLORIDE COTRANSPORTER 2 (KCC2) GENE EXPRESSION WAS EXAMINED TO ELUCIDATE THE POTENTIAL CONTRIBUTING MECHANISM. METHODS: MALE SPRAGUE-DAWLEY RATS WERE INJECTED WITH CFA INTO THE PLANTAR SURFACE OF THE LEFT HIND PAW TO INDUCE INFLAMMATION. PRF (20 MINUTES OF 500-KHZ RF PULSES, DELIVERED AT A RATE OF 2 HZ, MAXIMUM TEMPERATURE 42 MASCULINEC) WAS DELIVERED TO THE L5 AND L6 ANTERIOR PRIMARY RAMUS JUST DISTAL TO THE INTERVERTEBRAL FORAMEN OF ADULT CFA OR SALINE RATS. THE HIND PAW WITHDRAWAL THRESHOLD TO VON FREY FILAMENT STIMULI AND WITHDRAWAL LATENCY TO RADIANT HEAT WERE DETERMINED BEFORE AND AFTER CFA. ACETYL-HISTONE H3 AND H4 WAS DETERMINED BY CHROMATIN IMMUNOPRECIPITATION IN SPINAL DORSAL HORN. KCC2 EXPRESSION WAS DETERMINED BY WESTERN BLOT. INHIBITORY SYNAPTIC FUNCTION WAS EVALUATED BY PATCH CLAMP IN LAMINA II NEURONS. RESULTS: KCC2 GENE EXPRESSION WAS SUPPRESSED THROUGH HISTONE HYPOACETYLATION, RESULTING IN DECREASED EFFICACY OF GABAERGIC SIGNALING IN CFA RATS. PRF INCREASED HISTONE ACETYLATION AND KCC2 EXPRESSION, PARTIALLY RESTORED THE GABA SYNAPTIC FUNCTION, AND RELIEVED SENSITIZED PAIN BEHAVIOR. CONCLUSION: THESE FINDINGS SUGGEST THAT PRF MIGHT BE AN ALTERNATIVE THERAPY FOR INFLAMMATORY PAIN. ONE OF THE UNDERLYING MECHANISMS IS THROUGH MODIFICATION OF KCC2, WHICH IS AN IMPORTANT DETERMINANT FOR THE EFFICACY OF INHIBITORY NEUROTRANSMISSION IN THE SPINAL CORD, AND ITS EXPRESSION LEVELS ARE REGULATED BY HISTONE ACETYLATION EPIGENETICALLY FOLLOWING INFLAMMATION.	2017	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
19  3809  38 INTRAPERITONEAL 5-AZACYTIDINE ALLEVIATES NERVE INJURY-INDUCED PAIN IN RATS BY MODULATING DNA METHYLATION. TO INVESTIGATE THE ROLE OF DNA METHYLATION IN MODULATING CHRONIC NEUROPATHIC PAIN (NPP), IDENTIFY POSSIBLE TARGET GENES OF DNA METHYLATION INVOLVED IN THIS PROCESS, AND PRELIMINARILY CONFIRM THE MEDICINAL VALUE OF THE DNA METHYLTRANSFERASES (DNMTS) INHIBITOR 5-AZACYTIDINE (5-AZA) IN NPP BY TARGETING GENE METHYLATION. TWO RAT NPP MODELS, CHRONIC CONSTRICTION INJURY (CCI) AND SPINAL NERVE LIGATION (SNL), WERE USED. THE DNA METHYLATION PROFILES IN THE LUMBAR SPINAL CORD WERE ASSAYED USING AN ARRAYSTAR RAT REFSEQ PROMOTER ARRAY. THE UNDERLYING GENES WITH DIFFERENTIAL METHYLATION WERE THEN IDENTIFIED AND SUBMITTED TO GENE ONTOLOGY AND PATHWAY ANALYSIS. METHYL-DNA IMMUNOPRECIPITATION QUANTITATIVE PCR (MEDIP-QPCR) AND QUANTITATIVE REVERSE TRANSCRIPTION-PCR (RT-QPCR) WERE USED TO CONFIRM GENE METHYLATION AND EXPRESSION. THE PROTECTIVE FUNCTION OF 5-AZA IN NPP AND GENE EXPRESSION WERE EVALUATED VIA BEHAVIORAL ASSAYS AND RT-QPCR, RESPECTIVELY. ANALYSIS OF THE DNA METHYLATION PATTERNS IN THE LUMBAR SPINAL CORD INDICATED THAT 1205 DIFFERENTIALLY METHYLATED FRAGMENTS IN CCI RATS WERE LOCATED WITHIN DNA PROMOTER REGIONS, INCLUDING 638 HYPERMETHYLATED FRAGMENTS AND 567 HYPOMETHYLATED FRAGMENTS. THE METHYLATION LEVELS OF GRM4, HTR4, ADRB2, KCNF1, GAD2, AND PPARG, WHICH ARE ASSOCIATED WITH LONG-TERM POTENTIATION (LTP) AND GLUTAMATERGIC SYNAPSE PATHWAYS, WERE INCREASED WITH A CORRESPONDING DECREASE IN THEIR MRNA EXPRESSION, IN THE SPINAL CORDS OF CCI RATS. MOREOVER, WE FOUND THAT THE INTRAPERITONEAL INJECTION OF 5-AZA (4 MG/KG) ATTENUATED CCI- OR SNL-INDUCED MECHANICAL ALLODYNIA AND THERMAL HYPERALGESIA. FINALLY, THE MRNA EXPRESSION OF HYPERMETHYLATED GENES SUCH AS GRM4, HTR4, ADRB2, KCNF1, AND GAD2 WAS REVERSED AFTER 5-AZA TREATMENT. CCI INDUCED WIDESPREAD METHYLATION CHANGES IN THE DNA PROMOTER REGIONS IN THE LUMBAR SPINAL CORD. INTRAPERITONEAL 5-AZA ALLEVIATED HYPERALGESIA IN CCI AND SNL RATS, AN EFFECT ACCOMPANIED BY THE REVERSED EXPRESSION OF HYPERMETHYLATED GENES. THUS, DNA METHYLATION INHIBITION REPRESENTS A PROMISING EPIGENETIC STRATEGY FOR PROTECTION AGAINST CHRONIC NPP FOLLOWING NERVE INJURY. OUR STUDY LAYS A THEORETICAL FOUNDATION FOR 5-AZA TO BECOME A CLINICAL TARGETED DRUG.	2023	
                                                                                                                                                                                                                                  
20  1818  34 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