1 1320 117 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 2 2300 51 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 3 3832 37 INVOLVEMENT OF SPINAL SIRT1 IN DEVELOPMENT OF CHRONIC CONSTRICTION INJURY INDUCED NEUROPATHIC PAIN IN RATS. IT IS KNOWN THAT THE EPIGENETIC PROCESS OF HISTONE ACETYLATION IS INVOLVED IN THE NEUROPATHIC PAIN. THE AIM OF THIS STUDY WAS TO DETERMINE WHETHER SIRTUIN TYPE 1 (SIRT1), AN NAD(+) DEPENDENT DEACETYLASE, AFFECTED ALLODYNIA AND HYPERALGESIA IN NEUROPATHIC PAIN. THE NEUROPATHIC PAIN MODEL WAS ESTABLISHED BY LIGATURE OF THE RIGHT SCIATIC NERVE TO INDUCE CHRONIC CONSTRICTION INJURY (CCI) IN RATS. HISTONE ACETYLTRANSFERASE (HAT) ACTIVITY WAS INCREASED AND, AND HISTONE DEACETYLASE (HDAC) ACTIVITY WAS DECLINED IN TISSUE OF THE SPINAL DORSA HORN IN CCI RATES BY MEANS OF ENZYME-LINKED IMMUNOSORBENT ASSAY (ELISA). THE PERSISTENT HYPERALGESIA AND ALLODYNIA CAUSED BY CCI WERE ASSOCIATED WITH DOWNREGULATION OF SIRT1 AND UPREGULATION OF ACETYLATED-H3 (AC-H3) IN TISSUE OF THE SPINAL CORD BY WESTERN BLOT ASSAY, WHICH WAS REVERSED AFTER INTRATHECAL INJECTION OF SIRT1 AGONIST SRT1720. SRT1720 TREATMENT ACHIEVED ANALGESIC THROUGH INHIBITING THE ACETYLATION OF NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND BLOCKING THE RELEASES OF THE INFLAMMATORY FACTORS INCLUDING TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA) AND INTERLEUKIN (IL)-6 BY MEANS OF WESTERN BLOT AND REAL-TIME QUANTITATIVE PCR (RT-PCR), RESPECTIVELY. TAKEN TOGETHER, THESE DATA SUGGEST THAT SIRT1 IN THE SPINAL CORD PLAYS AN IMPORTANT ROLE IN THE NEUROPATHIC PAIN IN THE RAT MODEL. 2018 4 6660 49 UPREGULATION OF CXCR4 THROUGH PROMOTER DEMETHYLATION CONTRIBUTES TO INFLAMMATORY HYPERALGESIA IN RATS. AIM AND METHODS: CHRONIC PAIN ASSOCIATED WITH INFLAMMATION IS A COMMON CLINICAL PROBLEM, AND THE UNDERLYING MECHANISMS YET ARE INCOMPLETELY DEFINED. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF CHRONIC PAIN. HOWEVER, THE SPECIFIC GENES REGULATED BY DNA METHYLATION UNDER INFLAMMATORY PAIN CONDITION REMAIN LARGELY UNKNOWN. HERE, WE INVESTIGATED HOW CHEMOKINE RECEPTOR CXCR4 EXPRESSION IS REGULATED BY DNA METHYLATION AND HOW IT CONTRIBUTES TO INFLAMMATORY PAIN INDUCED BY COMPLETE FREUND'S ADJUVANT (CFA) IN RATS. RESULTS: INTRAPLANTAR INJECTION OF CFA COULD NOT ONLY INDUCE SIGNIFICANT HYPERALGESIA IN RATS, BUT ALSO SIGNIFICANTLY INCREASE THE EXPRESSION OF CXCR4 MRNA AND PROTEIN IN THE DORSAL ROOT GANGLION (DRG). INTRATHECAL INJECTION OF CXCR4 ANTAGONIST AMD3100 SIGNIFICANTLY RELIEVED HYPERALGESIA IN INFLAMMATORY RATS IN A TIME- AND DOSE-DEPENDENT MANNER. BISULFITE SEQUENCING AND METHYLATION-SPECIFIC PCR DEMONSTRATE THAT CFA INJECTION LED TO A SIGNIFICANT DEMETHYLATION OF CPG ISLAND AT CXCR4 GENE PROMOTER. CONSISTENTLY, THE EXPRESSION OF DNMT3B WAS SIGNIFICANTLY DOWNREGULATED AFTER CFA INJECTION. ONLINE SOFTWARE PREDICTION REVEALS THREE BINDING SITES OF P65 IN THE CPG ISLAND OF CXCR4 GENE PROMOTER, WHICH HAS CONFIRMED BY THE CHROMATIN IMMUNOPRECIPITATION ASSAY, CFA TREATMENT SIGNIFICANTLY INCREASES THE RECRUITMENT OF P65 TO CXCR4 GENE PROMOTER. INHIBITION OF NF-KB SIGNALING USING P65 INHIBITOR PYRROLIDINE DITHIOCARBAMATE SIGNIFICANTLY PREVENTED THE INCREASES OF THE CXCR4 EXPRESSION. CONCLUSION: UPREGULATION OF CXCR4 EXPRESSION DUE TO PROMOTER DEMETHYLATION FOLLOWED BY INCREASED RECRUITMENT OF P65 TO PROMOTER OF CXCR4 GENE CONTRIBUTES TO INFLAMMATORY HYPERALGESIA. THESE FINDINGS PROVIDE A THEORETICAL BASIS FOR THE TREATMENT OF CHRONIC PAIN FROM AN EPIGENETIC PERSPECTIVE. 2018 5 3459 38 HYPOMETHYLATION OF NERVE GROWTH FACTOR (NGF) PROMOTES BINDING OF C/EBPALPHA AND CONTRIBUTES TO INFLAMMATORY HYPERALGESIA IN RATS. BACKGROUND: CHRONIC PAIN USUALLY ACCOMPANIED BY TISSUE DAMAGE AND INFLAMMATION. HOWEVER, THE PATHOGENESIS OF CHRONIC PAIN REMAINS UNCLEAR. METHODS: WE INVESTIGATED THE ROLE OF NERVE GROWTH FACTOR (NGF) IN CHRONIC INFLAMMATORY PAIN INDUCED BY COMPLETE FREUND'S ADJUVANT (CFA), EXPLORED THE METHYLATION STATUS OF CPG ISLANDS IN THE PROMOTER REGION OF THE NGF GENE, AND CLARIFIED THE FUNCTION AND MECHANISM OF C/EBPALPHA-NGF SIGNALING PATHWAY FROM EPIGENETIC PERSPECTIVE IN THE CHRONIC INFLAMMATORY PAIN MODEL. RESULTS: CFA INDUCED SIGNIFICANT HYPERALGESIA AND CONTINUOUS UPREGULATION OF NGF MRNA AND PROTEIN LEVELS IN THE L4-6 DORSAL ROOT GANGLIONS (DRGS) IN RATS. HYPOMETHYLATION OF CPG ISLANDS OCCURRED IN THE NGF GENE PROMOTER REGION AFTER CFA TREATMENT. AT THE SAME TIME, THE MIR-29B EXPRESSION LEVEL WAS SIGNIFICANTLY INCREASED, WHILE THE DNA METHYLTRANSFERASE 3B (DNMT3B) LEVEL REDUCED SIGNIFICANTLY. MOREOVER, CFA TREATMENT PROMOTED BINDING OF C/EBPALPHA TO THE NGF GENE PROMOTER REGION AND C/EBPALPHA SIRNA TREATMENT OBVIOUSLY DECREASED EXPRESSION OF NGF LEVELS AND ALSO ALLEVIATE INFLAMMATORY HYPERALGESIA SIGNIFICANTLY IN RATS. CONCLUSION: COLLECTIVELY, THE RESULTS INDICATED THAT CFA LEADS TO THE UPREGULATION OF MIR-29B LEVEL, WHICH REPRESSES THE EXPRESSION OF DNMT3B, ENHANCES THE DEMETHYLATION OF THE NGF GENE PROMOTER REGION, AND PROMOTES THE BINDING OF C/EBPALPHA WITH THE NGF GENE PROMOTER, THUS RESULTS IN THE UPREGULATION OF NGF GENE EXPRESSION AND MAINTENANCE OF CHRONIC INFLAMMATORY PAIN. 2020 6 1906 33 ENHANCER OF ZESTE HOMOLOG 2-CATALYSED H3K27 TRIMETHYLATION PLAYS A KEY ROLE IN ACUTE-ON-CHRONIC LIVER FAILURE VIA TNF-MEDIATED PATHWAY. ACUTE-ON-CHRONIC LIVER FAILURE IS MAINLY DUE TO HOST IMMUNITY SELF-DESTRUCTION. THE HISTONE H3 LYSINE 27 (H3K27) TRIMETHYLATING ENZYME, ENHANCER OF ZESTE HOMOLOG 2 (EZH2) MEDIATES EPIGENETIC SILENCING OF GENE EXPRESSION AND REGULATES IMMUNITY, ALSO INVOLVES PATHOGENESIS OF SEVERAL LIVER DISEASES. THE CURRENT STUDY WAS TO DETERMINE THE ROLE OF METHYLTRANSFERASE EZH2 AND ITS CATALYSED H3K27 TRIMETHYLATION (H3K27ME3) IN LIVER FAILURE, AND TO FURTHER INVESTIGATE THE POTENTIAL TARGET FOR LIVER FAILURE TREATMENT. EZH2 AND ITS CATALYSED H3K27ME3 WERE DETERMINED IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMC) FROM LIVER FAILURE PATIENTS AND KUPFFER CELLS FROM EXPERIMENTAL MICE. FURTHERMORE, GSK126 (AN INHIBITOR FOR EZH2 TRIMETHYLATION FUNCTION) WAS APPLIED IN LIVER FAILURE MICE IN VIVO, AND LIPOPOLYSACCHARIDE-STIMULATED MONONUCLEAR CELLS IN VITRO. EZH2 AND H3K27ME3 WERE SIGNIFICANTLY UPREGULATED IN HUMAN PBMC FROM LIVER FAILURE PATIENTS OR MURINE KUPFFER CELLS FROM THE LIVER FAILURE ANIMALS, RESPECTIVELY. GSK126 AMELIORATED DISEASE SEVERITY IN LIVER FAILURE MICE, WHICH MAYBE ATTRIBUTE TO DOWN-REGULATE CIRCULATING AND HEPATIC PROINFLAMMATORY CYTOKINES, ESPECIALLY TNF VIA REDUCING H3K27ME3. IN-DEPTH CHROMATIN IMMUNOPRECIPITATION ANALYSIS UNRAVELLED THAT DECREASED ENRICHMENT OF H3K27ME3 ON TNF PROMOTOR, RESULTING IN TNF ELEVATION IN KUPFFER CELLS FROM LIVER FAILURE MICE. NUCLEAR FACTOR KAPPA B (NF-KAPPAB) AND PROTEIN KINASE B (AKT) SIGNALLING PATHWAYS WERE ACTIVATED UPON LIPOPOLYSACCHARIDE STIMULATION, BUT ATTENUATED BY USING GSK126, ACCOMPANIED WITH DECREASED TNF IN VITRO. IN CONCLUSION, EZH2 AND H3K27ME3 CONTRIBUTED TO THE PATHOGENESIS OF LIVER FAILURE VIA TRIGGERING TNF AND OTHER INDISPENSABLE PROINFLAMMATORY CYTOKINES. EZH2 WAS TO MODIFY H3K27ME3 ENRICHMENT, AS WELL AS, ACTIVATION OF THE DOWNSTREAM NF-KAPPAB AND AKT SIGNALLING PATHWAYS. 2018 7 3082 45 GENOME-WIDE REDISTRIBUTION OF MECP2 IN DORSAL ROOT GANGLIA AFTER PERIPHERAL NERVE INJURY. BACKGROUND: METHYL-CPG-BINDING PROTEIN 2 (MECP2), A PROTEIN WITH AFFINITY FOR METHYLATED CYTOSINES, IS CRUCIAL FOR NEURONAL DEVELOPMENT AND FUNCTION. MECP2 REGULATES GENE EXPRESSION THROUGH ACTIVATION, REPRESSION AND CHROMATIN REMODELING. MUTATIONS IN MECP2 CAUSE RETT SYNDROME, AND THESE PATIENTS DISPLAY IMPAIRED NOCICEPTION. WE OBSERVED AN INCREASE IN MECP2 EXPRESSION IN MOUSE DORSAL ROOT GANGLIA (DRG) AFTER PERIPHERAL NERVE INJURY. THE FUNCTIONAL IMPLICATION OF INCREASED MECP2 IS LARGELY UNKNOWN. TO IDENTIFY REGIONS OF THE GENOME BOUND BY MECP2 IN THE DRG AND THE CHANGES INDUCED BY NERVE INJURY, A CHROMATIN IMMUNOPRECIPITATION OF MECP2 FOLLOWED BY SEQUENCING (CHIP-SEQ) WAS PERFORMED 4 WEEKS AFTER SPARED NERVE INJURY (SNI). RESULTS: WHILE THE NUMBER OF BINDING SITES ACROSS THE GENOME REMAINED SIMILAR IN THE SNI MODEL AND SHAM CONTROL, SNI INDUCED THE REDISTRIBUTION OF MECP2 TO TRANSCRIPTIONALLY RELEVANT REGIONS. TO DETERMINE HOW DIFFERENTIAL BINDING OF MECP2 CAN AFFECT GENE EXPRESSION IN THE DRG, WE INVESTIGATED MMU-MIR-126, A MICRORNA LOCUS THAT HAD ENRICHED MECP2 BINDING IN THE SNI MODEL. ENRICHED MECP2 BINDING TO MIR-126 LOCUS AFTER NERVE INJURY REPRESSED MIR-126 EXPRESSION, AND THIS WAS NOT MEDIATED BY ALTERATIONS IN METHYLATION PATTERN AT THE MIR-126 LOCUS. DOWNREGULATION OF MIR-126 RESULTED IN THE UPREGULATION OF ITS TWO TARGET GENES DNMT1 AND VEGFA IN NEURO 2A CELLS AND IN SNI MODEL COMPARED TO CONTROL. THESE TARGET GENES WERE SIGNIFICANTLY DOWNREGULATED IN MECP2-NULL MICE COMPARED TO WILD-TYPE LITTERMATES, INDICATING A REGULATORY ROLE FOR MECP2 IN ACTIVATING DNMT1 AND VEGFA EXPRESSION. INTRATHECAL DELIVERY OF MIR-126 WAS NOT SUFFICIENT TO REVERSE NERVE INJURY-INDUCED MECHANICAL AND THERMAL HYPERSENSITIVITY, BUT DECREASED DNMT1 AND VEGFA EXPRESSION IN THE DRG. CONCLUSIONS: OUR STUDY SHOWS A REGULATORY ROLE FOR MECP2 IN THAT CHANGES IN GLOBAL REDISTRIBUTION CAN RESULT IN DIRECT AND INDIRECT MODULATION OF GENE EXPRESSION IN THE DRG. ALTERATIONS IN GENOME-WIDE BINDING OF MECP2 THEREFORE PROVIDE A MOLECULAR BASIS FOR A BETTER UNDERSTANDING OF EPIGENETIC REGULATION-INDUCED MOLECULAR CHANGES UNDERLYING NERVE INJURY. 2016 8 1631 39 DNMT3A METHYLATION IN NEUROPATHIC PAIN. BACKGROUND: MU OPIOID RECEPTOR (MOR) PLAYS A CRUCIAL ROLE IN MEDIATING ANALGESIC EFFECTS OF OPIOIDS AND IS CLOSELY ASSOCIATED WITH THE PATHOLOGIES OF NEUROPATHIC PAIN. PREVIOUS STUDIES HAVE REPORTED THAT PERIPHERAL NERVE INJURY DOWNREGULATES MOR EXPRESSION, BUT THE EPIGENETIC MECHANISMS REMAIN UNKNOWN. OBJECTIVE: THEREFORE, WE INVESTIGATED DNA METHYLTRANSFERASE3A (DNMT3A) EXPRESSION OR METHYLATION CHANGES WITHIN MOR PROMOTER IN THE SPINAL CORD IN A NEUROPATHIC PAIN INDUCED BY A CHRONIC CONSTRICTION INJURY (CCI) MOUSE MODEL AND FURTHER DETERMINED WHETHER THESE INJURY-ASSOCIATED CHANGES ARE REVERSIBLE BY PHARMACOLOGICAL INTERVENTIONS. METHODS: A CCI MOUSE MODEL WAS ESTABLISHED AND TISSUE SPECIMENS OF LUMBAR SPINAL CORDS WERE COLLECTED. THE NOCICEPTION THRESHOLD WAS EVALUATED BY A MODEL HEATED 400 BASE. DNMT3A AND MOR MRNA AND PROTEIN LEVEL WERE DETECTED BY REAL-TIME-POLYMERASE CHAIN REACTION AND WESTERN BLOT, RESPECTIVELY. METHYLATION OF DNMT3A GENE WAS MEASURED BY METHYLATION-SPECIFIC PCR. RESULTS: OUR DATA SHOWED THAT CHRONIC NERVE INJURY LED TO A SIGNIFICANT UPREGULATION OF DNMT3A EXPRESSION THAT WAS ASSOCIATED WITH INCREASED METHYLATION OF MOR GENE PROMOTER AND DECREASED MOR PROTEIN EXPRESSION IN THE SPINAL CORD. INHIBITION OF DNMT3A CATALYTIC ACTIVITY WITH DNMT INHIBITOR RG108 SIGNIFICANTLY BLOCKED THE INCREASE IN METHYLATION OF THE MOR PROMOTER, AND THEN UPREGULATED MOR EXPRESSION AND ATTENUATED THERMAL HYPERALGESIA IN NEUROPATHIC PAIN MICE. CONCLUSION: THIS STUDY DEMONSTRATES THAT AN INCREASE OF DNMT3A EXPRESSION AND MOR METHYLATION EPIGENETICALLY PLAY AN IMPORTANT ROLE IN NEUROPATHIC PAIN. TARGETING DNMT3A TO THE PROMOTER OF MOR GENE BY DNMT INHIBITOR MAY BE A PROMISING APPROACH TO THE DEVELOPMENT OF NEW NEUROPATHIC PAIN THERAPY. 2017 9 5266 50 PROMOTED INTERACTION OF C/EBPALPHA WITH DEMETHYLATED CXCR3 GENE PROMOTER CONTRIBUTES TO NEUROPATHIC PAIN IN MICE. DNA METHYLATION HAS BEEN IMPLICATED IN THE PATHOGENESIS OF CHRONIC PAIN. HOWEVER, THE SPECIFIC GENES REGULATED BY DNA METHYLATION UNDER NEUROPATHIC PAIN CONDITION REMAIN LARGELY UNKNOWN. HERE WE INVESTIGATED HOW CHEMOKINE RECEPTOR CXCR3 IS REGULATED BY DNA METHYLATION AND HOW IT CONTRIBUTES TO NEUROPATHIC PAIN INDUCED BY SPINAL NERVE LIGATION (SNL) IN MICE. SNL INCREASED CXCR3 MRNA AND PROTEIN EXPRESSION IN THE NEURONS OF THE SPINAL CORD. MEANWHILE, THE CPG (5'-CYTOSINE-PHOSPHATE-GUANINE-3') ISLAND IN THE CXCR3 GENE PROMOTER REGION WAS DEMETHYLATED, AND THE EXPRESSION OF DNA METHYLTRANSFERASE 3B (DNMT3B) WAS DECREASED. SNL ALSO INCREASED THE BINDING OF CCAAT (CYTIDINE-CYTIDINE-ADENOSINE-ADENOSINE-THYMIDINE)/ENHANCER BINDING PROTEIN ALPHA (C/EBPALPHA) WITH CXCR3 PROMOTER AND DECREASED THE BINDING OF DNMT3B WITH CXCR3 PROMOTER IN THE SPINAL CORD. C/EBPALPHA EXPRESSION WAS INCREASED IN SPINAL NEURONS AFTER SNL, AND INHIBITION OF C/EBPALPHA BY INTRATHECAL SMALL INTERFERING RNA ATTENUATED SNL-INDUCED PAIN HYPERSENSITIVITY AND REDUCED CXCR3 EXPRESSION. FURTHERMORE, SNL-INDUCED MECHANICAL ALLODYNIA AND HEAT HYPERALGESIA WERE MARKEDLY REDUCED IN CXCR3(-/-) MICE. SPINAL INHIBITION OF CXCR3 BY SHRNA OR CXCR3 ANTAGONIST ALSO ATTENUATED ESTABLISHED NEUROPATHIC PAIN. MOREOVER, CXCL10, THE LIGAND OF CXCR3, WAS INCREASED IN SPINAL NEURONS AND ASTROCYTES AFTER SNL. SUPERFUSING SPINAL CORD SLICES WITH CXCL10 ENHANCED SPONTANEOUS EPSCS AND POTENTIATED NMDA-INDUCED AND AMPA-INDUCED CURRENTS OF LAMINA II NEURONS. FINALLY, INTRATHECAL INJECTION OF CXCL10 INDUCED CXCR3-DEPENDENT PAIN HYPERSENSITIVITY IN NAIVE MICE. COLLECTIVELY, OUR RESULTS DEMONSTRATED THAT CXCR3, INCREASED BY DNA DEMETHYLATION AND THE ENHANCED INTERACTION WITH C/EBPALPHA, CAN BE ACTIVATED BY CXCL10 TO FACILITATE EXCITATORY SYNAPTIC TRANSMISSION AND CONTRIBUTE TO THE MAINTENANCE OF NEUROPATHIC PAIN. SIGNIFICANCE STATEMENT: PERIPHERAL NERVE INJURY INDUCES CHANGES OF GENE EXPRESSION IN THE SPINAL CORD THAT MAY CONTRIBUTE TO THE PATHOGENESIS OF NEUROPATHIC PAIN. CXCR3 IS A CHEMOKINE RECEPTOR. WHETHER IT IS INVOLVED IN NEUROPATHIC PAIN AND HOW IT IS REGULATED AFTER NERVE INJURY REMAIN LARGELY UNKNOWN. OUR STUDY DEMONSTRATES THAT SPINAL NERVE LIGATION DOWNREGULATES THE EXPRESSION OF DNMT3B, WHICH MAY CAUSE DEMETHYLATION OF CXCR3 GENE PROMOTER AND FACILITATE THE BINDING OF CCAAT/ENHANCER BINDING PROTEIN ALPHA WITH CXCR3 PROMOTER AND FURTHER INCREASE CXCR3 EXPRESSION IN SPINAL NEURONS. THE UPREGULATED CXCR3 MAY CONTRIBUTE TO NEUROPATHIC PAIN BY FACILITATING CENTRAL SENSITIZATION. OUR STUDY REVEALS AN EPIGENETIC MECHANISM UNDERLYING CXCR3 EXPRESSION AND ALSO SUGGESTS THAT TARGETING THE EXPRESSION OR ACTIVATION OF CXCR3 SIGNALING MAY OFFER NEW THERAPEUTICS FOR NEUROPATHIC PAIN. 2017 10 4906 45 P300 EXERTS AN EPIGENETIC ROLE IN CHRONIC NEUROPATHIC PAIN THROUGH ITS ACETYLTRANSFERASE ACTIVITY IN RATS FOLLOWING CHRONIC CONSTRICTION INJURY (CCI). BACKGROUND: NEUROPATHIC PAIN IS DETRIMENTAL TO HUMAN HEALTH; HOWEVER, ITS PATHOGENESIS STILL REMAINS LARGELY UNKNOWN. OVEREXPRESSION OF PAIN-ASSOCIATED GENES AND INCREASED NOCICEPTIVE SOMATO-SENSITIVITY ARE WELL OBSERVED IN NEUROPATHIC PAIN. THE IMPORTANCE OF EPIGENETIC MECHANISMS IN REGULATING THE EXPRESSION OF PRO- OR ANTI-NOCICEPTIVE GENES HAS BEEN REVEALED BY STUDIES RECENTLY, AND WE HYPOTHESIZE THAT THE TRANSCRIPTIONAL COACTIVATOR AND THE HISTONE ACETYLTRANSFERASE E1A BINDING PROTEIN P300 (P300), AS A PART OF THE EPIGENETIC MECHANISMS OF GENE REGULATION, MAY BE INVOLVED IN THE PATHOGENESIS OF NEUROPATHIC PAIN INDUCED BY CHRONIC CONSTRICTION INJURY (CCI). TO TEST THIS HYPOTHESIS, TWO DIFFERENT APPROACHES WERE USED IN THIS STUDY: (I) DOWN-REGULATING P300 WITH SPECIFIC SMALL HAIRPIN RNA (SHRNA) AND (II) CHEMICAL INHIBITION OF P300 ACETYLTRANSFERASE ACTIVITY BY A SMALL MOLECULE INHIBITOR, C646. RESULTS: USING THE CCI RAT MODEL, WE FOUND THAT THE P300 EXPRESSION WAS INCREASED IN THE LUMBAR SPINAL CORD ON DAY 14 AFTER CCI. THE TREATMENT WITH INTRATHECAL P300 SHRNA REVERSED CCI-INDUCED MECHANICAL ALLODYNIA AND THERMAL HYPERALGESIA, AND SUPPRESSED THE EXPRESSION OF CYCLOOXYGENASE-2 (COX-2), A NEUROPATHIC PAIN-ASSOCIATED FACTOR. FURTHERMORE, C646, AN INHIBITOR OF P300 ACETYLTRANSFERASE, ALSO ATTENUATED MECHANICAL ALLODYNIA AND THERMAL HYPERALGESIA, ACCOMPANIED BY A SUPPRESSED COX-2 EXPRESSION, IN THE SPINAL CORD. CONCLUSIONS: THE RESULTS SUGGEST THAT, THROUGH ITS ACETYLTRANSFERASE ACTIVITY IN THE SPINAL CORD AFTER CCI, P300 EPIGENETICALLY PLAYS AN IMPORTANT ROLE IN NEUROPATHIC PAIN. INHIBITING P300, USING INTERFERING RNA OR C646, MAY BE A PROMISING APPROACH TO THE DEVELOPMENT OF NEW NEUROPATHIC PAIN THERAPIES. 2012 11 1831 42 EFFECTS OF MATERNAL SEPARATION AND ANTIDEPRESSANT DRUG ON EPIGENETIC REGULATION OF THE BRAIN-DERIVED NEUROTROPHIC FACTOR EXON I PROMOTER IN THE ADULT RAT HIPPOCAMPUS. AIM: EARLY LIFE STRESS CAN INDUCE EPIGENETIC CHANGES THROUGH GENETIC AND ENVIRONMENTAL INTERACTIONS AND IS A RISK FACTOR FOR DEPRESSION. BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) HAS BEEN IMPLICATED IN THE PATHOPHYSIOLOGY OF DEPRESSION AND ANTIDEPRESSANT DRUG ACTION. WE INVESTIGATED EPIGENETIC CHANGES AT THE BDNF EXON I PROMOTER IN THE HIPPOCAMPUS OF ADULT RATS SUBJECTED TO MATERNAL SEPARATION (MS) DURING EARLY LIFE AND TREATED WITH AN ANTIDEPRESSANT DRUG AS ADULTS. METHODS: RAT PUPS WERE SUBJECTED TO MS FROM POSTNATAL DAY 1 TO 21 AND RECEIVED CHRONIC ESCITALOPRAM (ESC) AS ADULTS. WE ASSESSED THE EFFECTS OF MS AND ESC ON BDNF EXON I AND DNA METHYLTRANSFERASES (DNMT) MRNA LEVELS (QUANTITATIVE REVERSE-TRANSCRIPTION POLYMERASE CHAIN REACTION), ACETYLATED HISTONE H3, AND MECP2 BINDING TO THE BDNF PROMOTER I (CHROMATIN IMMUNOPRECIPITATION FOLLOWED BY REAL-TIME POLYMERASE CHAIN REACTION), AND BDNF PROTEIN LEVELS (ENZYME-LINKED IMMUNOSORBENT ASSAY). RESULTS: THE LEVELS OF BDNF PROTEIN, EXON I MRNA, HISTONE H3 ACETYLATION, AND DNMT1 AND DNMT3A MRNA WERE ALTERED IN THE MS GROUP COMPARED WITH THE CONTROL GROUP. SIGNIFICANT DECREASES WERE OBSERVED IN THE BDNF PROTEIN, EXON I MRNA, AND HISTONE H3 ACETYLATION LEVELS AND THERE WERE SIGNIFICANT INCREASES IN DNMT1 AND DNMT3A MRNA LEVELS. THE COMPARISON BETWEEN THE MS + ESC AND MS GROUPS REVEALED SIGNIFICANT INCREASES IN BDNF PROTEIN, EXON I MRNA, AND HISTONE H3 ACETYLATION LEVELS AND SIGNIFICANT DECREASES IN MECP2 AND DNMT1 AND DNMT3A MRNA LEVELS. CONCLUSION: THESE FINDINGS INDICATE THAT MS INDUCED EPIGENETIC CHANGES AT THE BDNF EXON I PROMOTER AND THESE CHANGES WERE PREVENTED BY ANTIDEPRESSANT DRUG TREATMENT DURING ADULTHOOD. 2018 12 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 13 766 32 CCL5 SUPPRESSES KLOTHO EXPRESSION VIA P-STAT3/DNA METHYLTRANSFERASE1-MEDIATED PROMOTER HYPERMETHYLATION. BACKGROUND: ENHANCED INFLAMMATION AND REDUCED KLOTHO ARE COMMON FEATURES IN CHRONIC KIDNEY DISEASE (CKD). INFLAMMATION INDUCES DNA HYPERMETHYLATION. THIS STUDY ASSESSED THE PERFORMANCE OF INFLAMMATORY MARKER C-C MOTIF CHEMOKINE 5 (CCL5) IN EPIGENETIC REGULATION OF KLOTHO EXPRESSION. METHODS: FIFTY CKD PATIENTS AND 25 MATCHED CONTROLS WERE ENROLLED, AND SERUM CCL5 LEVEL, SKLOTHO LEVEL, AND DNA METHYLATION WERE EVALUATED IN THESE SUBJECTS. A RENAL INTERSTITIAL FIBROSIS (RIF) MODEL WITH CKD WAS INDUCED IN MICE VIA UNILATERAL URETERAL OBSTRUCTION (UUO) IN VIVO AND HUMAN PROXIMAL TUBULAR EPITHELIAL (HK-2) CELLS TREATED WITH CCL5 IN VITRO. 5-AZA-2'-DEOXYCYTIDINE (5-AZA), A DNA METHYLTRANSFERASE INHIBITOR WAS GIVEN TO UUO MICE. HEMATOXYLIN AND EOSIN (HE) AND MASSON TRICHROME STAINING WERE ADOPTED TO EVALUATE RENAL PATHOLOGICAL CHANGES. METHYLATION-SPECIFIC PCR WAS PERFORMED TO ASSESS DNA METHYLATION OF KLOTHO PROMOTER IN THE PERIPHERAL BLOOD LEUCOCYTES (PBLS) FROM CKD PATIENTS AND OBSTRUCTIVE KIDNEY FROM UUO MICE. CCL5, KLOTHO, AND DNA METHYLTRANSFERASES (DNMTS) WERE DETERMINED BY ELISAS, IMMUNOFLUORESCENCE, OR WESTERN BLOTTING. HK-2 CELLS WERE EXPOSED TO CCL5 WITH OR WITHOUT 5-AZA AND STATTIC, A P-SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION 3 (STAT3) INHIBITOR, AND EXPRESSIONS OF P-STAT3, DNMT1, AND KLOTHO WERE DETERMINED BY WESTERN BLOTTING. RESULTS: CCL5 UPREGULATION CONCOMITANT WITH KLOTHO DOWNREGULATION IN SERUM AND GLOBAL DNA METHYLATION IN PBLS WERE OBSERVED IN CKD SAMPLES. UUO CONTRIBUTED TO SEVERE RENAL INTERSTITIAL FIBROSIS AND ENHANCED EXPRESSIONS OF FIBROTIC MARKERS. MOREOVER, UUO INCREASED THE CCL5 LEVEL, INDUCED KLOTHO PROMOTER METHYLATION, SUPPRESSED KLOTHO LEVEL, ACTIVATED P-STAT3 SIGNALING, AND UPREGULATED DNMT1 LEVEL. A SIMILAR OBSERVATION WAS MADE IN HK-2 CELLS TREATED WITH CCL5. MORE IMPORTANTLY, 5-AZA INHIBITED UUO-INDUCED KLOTHO HYPERMETHYLATION, REVERSED KLOTHO, DOWNREGULATED P-STAT3 EXPRESSIONS, AND AMELIORATED RIF IN VIVO. THE CONSISTENT FINDINGS IN VITRO WERE ALSO OBTAINED IN HK-2 CELLS EXPOSED TO 5-AZA AND STATTIC. CONCLUSION: THE CCL5/P-STAT3/DNMT1 AXIS IS IMPLICATED IN EPIGENETIC REGULATION OF KLOTHO EXPRESSION IN CKD. THIS STUDY PROVIDES NOVEL THERAPEUTIC POSSIBILITIES FOR REVERSAL OF KLOTHO SUPPRESSION BY CKD. 2022 14 2326 38 EPIGENETIC REGULATION OF HOTAIR IN ADVANCED CHRONIC MYELOID LEUKEMIA. PURPOSE: CHRONIC MYELOID LEUKEMIA (CML) ACCOUNTS FOR ~10% OF LEUKEMIA CASES, AND ITS PROGRESSION INVOLVES EPIGENETIC GENE REGULATION. THIS STUDY INVESTIGATED EPIGENETIC REGULATION OF HOTAIR AND ITS TARGET MICRORNA, MIR-143, IN ADVANCED CML. PATIENTS AND METHODS: WE FIRST ISOLATED BONE MARROW MONONUCLEAR CELLS FROM 70 PATIENTS WITH DIFFERENT PHASES OF CML AND FROM HEALTHY DONORS AS NORMAL CONTROL; WE ALSO CULTURED K562 AND KCL22 CELLS, TREATED WITH DEMETHYLATION DRUG; MTT ASSAY, FLOW CYTOMETRY, QUANTITATIVE REAL-TIME POLYMERASE CHAIN REACTION (QPCR), METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MSP), WESTERN BLOT, LUCIFERASE ASSAY, RNA PULL-DOWN ASSAY AND RNA-BINDING PROTEIN IMMUNOPRECIPITATION (RIP) ASSAY WERE PERFORMED. RESULT: AS MEASURED BY QPCR, HOTAIR EXPRESSION IN K562 CELLS, KCL22 CELLS, AND SAMPLES FROM CASES OF ADVANCED-STAGE CML INCREASED WITH LEVELS OF SEVERAL DNA METHYLTRANSFERASES AND HISTONE DEACETYLATES, INCLUDING DNMT1, DNMT3A, HDAC1, EZH2, AND LSD1, AND MIR-143 LEVELS WERE DECREASED AND HOTAIR LEVELS WERE INCREASED. TREATMENT WITH 5-AZACYTIDINE, A DNA METHYLATION INHIBITOR, DECREASED DNMT1, DNMT3A, HDAC1, EZH2, LSD1 MRNA, PROTEIN LEVELS, AND HOTAIR MRNA LEVELS BUT INCREASED MIR-143 LEVELS. HOTAIR KNOCKDOWN AND MIR-143 OVEREXPRESSION BOTH INHIBITED PROLIFERATION AND PROMOTED APOPTOSIS IN KCL22 AND K562 CELLS THROUGH THE PI3K/AKT PATHWAY. RNA PULL-DOWN, MASS SPECTROMETRY, AND RIP ASSAYS SHOWED THAT HOTAIR INTERACTED WITH EZH2 AND LSD1. A DUAL-LUCIFERASE ASSAY DEMONSTRATED THAT HOTAIR INTERACTED WITH MIR-143. CONCLUSION: OUR FINDINGS DEMONSTRATE THE KEY EPIGENETIC INTERACTIONS OF HOTAIR RELATED TO CML PROGRESSION AND SUGGEST HOTAIR AS A POTENTIAL THERAPEUTIC TARGET FOR ADVANCED CML. FURTHERMORE, OUR RESULTS SUPPORT THE USE OF DEMETHYLATION DRUGS AS A CML TREATMENT STRATEGY. 2018 15 1236 35 CURCUMIN AMELIORATES NEPHROSCLEROSIS VIA SUPPRESSION OF HISTONE ACETYLATION INDEPENDENT OF HYPERTENSION. BACKGROUND: ALTHOUGH HISTONE ACETYLATION, AN EPIGENETIC MODIFICATION, HAS BEEN REPORTED TO BE RELATED TO THE PROGRESSION OF VARIOUS DISEASES, ITS INVOLVEMENT IN NEPHROSCLEROSIS IS UNCLEAR. METHODS: DAHL SALT-SENSITIVE RATS WERE USED AS A MODEL OF NEPHROSCLEROSIS IN THIS STUDY. THE RATS WERE DIVIDED INTO THREE GROUPS: (I) NORMAL-SALT DIET GROUP, (II) HIGH-SALT DIET GROUP (HS), AND (III) HS ADMINISTERED DAILY WITH CURCUMIN, A HISTONE ACETYLTRANSFERASE INHIBITOR (HS+C). AT 6 WEEKS AFTER THE TREATMENT, THE KIDNEYS WERE DISSECTED. MORPHOLOGIC CHANGES WERE ASSESSED BY MASSON'S TRICHROME STAINING. THE NUMBER OF MACROPHAGES, FIBROBLASTS AND THE CELLS EXPRESSING ACETYLATED HISTONE H3 AT LYS 9 (H3K9) WERE ASSESSED BY IMMUNOHISTOCHEMISTRY. RESULTS: ALTHOUGH BOTH HS AND HS+C RATS REVEALED A MARKED INCREASE IN SYSTOLIC BLOOD PRESSURE, SERUM CREATININE WAS INCREASED ONLY IN HS RATS AT 6 WEEKS. IN THE HS RATS, NEPHROSCLEROSIS WAS INDUCED, ACCOMPANYING A SIGNIFICANT ACCUMULATION OF MACROPHAGES AND FIBROBLASTS. THE INFLAMMATION AND FIBROSIS WAS MARKEDLY SUPPRESSED IN THE HS+C GROUP. THE LEVEL OF HISTONE ACETYLATION AT LYS 9 WAS ENHANCED IN THE HS RATS, WHEREAS CURCUMIN ADMINISTRATION SUPPRESSED THE HISTONE ACETYLATION. MOREOVER, IN THE HS RATS, INTERLEUKIN-6 GENE EXPRESSION WAS ASSOCIATED WITH ACETYLATED H3K9, AS REVEALED BY CHROMATIN IMMUNOPRECIPITATION ASSAY. CONCLUSIONS: OUR RESULTS SUGGESTED THAT CURCUMIN AMELIORATES NEPHROSCLEROSIS VIA SUPPRESSION OF HISTONE ACETYLATION, INDEPENDENTLY OF HYPERTENSION. 2016 16 3324 42 HISTONE DEACETYLASE 2 IS INVOLVED IN MICRO?OPIOID RECEPTOR SUPPRESSION IN THE SPINAL DORSAL HORN IN A RAT MODEL OF CHRONIC PANCREATITIS PAIN. CHRONIC PAIN OCCURS IN ~85-90% OF CHRONIC PANCREATITIS (CP) PATIENTS. HOWEVER, AS THE PATHOGENESIS OF CP PAIN REMAINS TO BE FULLY UNDERSTOOD, THE CURRENT THERAPIES FOR CP PAIN REMAIN INADEQUATE. EMERGING EVIDENCE HAS SUGGESTED THAT THE EPIGENETIC MODULATIONS OF GENES ARE INVOLVED IN CHRONIC PAIN. IN THE PRESENT STUDY, INTRAPANCREATIC TRINITROBENZENE SULFONIC ACID INFUSIONS WERE USED TO ESTABLISH A CP MODEL IN RATS. MECHANICAL ALLODYNIA WAS MEASURED WITH VON FREY FILAMENTS. IMMUNOFLUORESCENT STAINING ANALYSIS WAS USED TO OBSERVE THE EXPRESSION CHANGES OF HISTONE DEACETYLASE 2 (HDAC2) AND MICRO?OPIOID RECEPTOR (MOR), AND INTRATHECAL ADMINISTRATION OF THE SELECTIVE HDAC2 INHIBITOR AR?42 WAS USED TO ASSESS THE UNDERLYING MECHANISMS. THE EXPRESSION LEVELS OF C?JUN N?TERMINAL KINASE (JNK) IN THE THORACIC SPINAL CORD WERE DETECTED BY WESTERN BLOTTING, AND THE MRNA EXPRESSION LEVELS OF INTERLEUKIN (IL)1?BETA, IL?6 AND TUMOR NECROSIS FACTOR (TNF)?ALPHA WERE DETECTED BY REVERSE TRANSCRIPTION?QUANTITATIVE POLYMERASE CHAIN REACTION. THE RESULTS DEMONSTRATED THAT HDAC2 EXPRESSION WAS UPREGULATED DURING THE COURSE OF CP INDUCTION, WHILE MOR ACTIVITY IN THE THORACIC SPINAL DORSAL HORN WAS SIGNIFICANTLY SUPPRESSED. INTRATHECAL INFUSION OF AR?42 SIGNIFICANTLY ATTENUATED CP?INDUCED MECHANICAL ALLODYNIA, WITH RESCUED MOR ACTIVITY. ADDITIONALLY, HDAC2 FACILITATED THE RELEASE OF INFLAMMATORY CYTOKINES, INCLUDING IL?1BETA, IL?6 AND TNF?ALPHA. THESE RESULTS SUGGESTED THAT THE UNDERLYING MECHANISMS OF HDAC2 REGULATING MOR ACTIVITY UNDER CP INDUCTION MAY OCCUR VIA PROMOTING THE RELEASE OF INFLAMMATORY CYTOKINES, THUS ACTIVATING THE JNK SIGNALING PATHWAY. THE PRESENT STUDY SUGGESTED THAT THE EPIGENETIC?REGULATED DISTURBANCE OF MOR IS DEPENDENT ON THE ENDOGENOUS ANALGESIA SYSTEM IN CP, WHICH MAY A PROVIDE NOVEL THERAPEUTIC STRATEGY FOR TREATING PAIN IN CP. 2018 17 2197 30 EPIGENETIC MODIFICATION OF BDNF MEDIATES NEUROPATHIC PAIN VIA MIR-30A-3P/EP300 AXIS IN CCI RATS. RECENT INVESTIGATION OF MICRORNAS ON CHRONIC PAIN HAS DEVELOPED A BREAKTHROUGH IN NEUROPATHIC PAIN MANAGEMENT. IN THE PRESENT STUDY, DECREASED EXPRESSION OF MIR-30A-3P WAS REPORTED USING QRT-PCR ANALYSIS AND LOSS OF MIR-30A-3P PROMOTED NEUROPATHIC PAIN PROGRESSION IN SCIATIC NERVE CHRONIC CONSTRICTIVE INJURY RATS THROUGH DETERMINING THE PAIN THRESHOLD. WE PREDICTED MIR-30A-3P COULD TARGET E-CADHERIN TRANSCRIPTIONAL ACTIVATOR (EP300) VIA BIOINFORMATICS ANALYSIS. MEANWHILE, WE FOUND THAT BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IS INVOLVED IN NEUROPATHIC PAIN. HERE, WE EXHIBITED THAT EP300 EPIGENETICALLY UP-REGULATED BDNF VIA ENHANCING ACETYLATED HISTONE H3 AND H4 ON THE PROMOTER. FOR ANOTHER, MIR-30A-3P WAS ABLE TO MODIFY THE LEVEL OF BDNF AND ACETYLATED HISTONE H3 AND H4. LOSS OF MIR-30A-3P ENHANCED EP300 AND BDNF COLOCALIZATION IN CCI RATS. SUBSEQUENTLY, IT WAS SHOWN THAT INCREASED EP300 INDUCED NEUROPATHIC PAIN BY AN ENHANCEMENT OF NEURONAL BDNF LEVEL IN VIVO. TO SUM UP, IT WAS REVEALED THAT EPIGENETIC MODIFICATION OF BDNF PROMOTED NEUROPATHIC PAIN VIA EP300 INDUCED BY MIR-30A-3P IN CCI RATS. 2020 18 5823 35 STRESS INCREASES DNA METHYLATION OF THE NEURONAL PAS DOMAIN 4 (NPAS4) GENE. NEURONAL PER ARNT SIM DOMAIN 4 (NPAS4), A BRAIN-SPECIFIC HELIX-LOOP-HELIX TRANSCRIPTION FACTOR, WAS RECENTLY SHOWN TO REGULATE THE DEVELOPMENT OF GABAERGIC INHIBITORY NEURONS. NPAS4 MRNA EXPRESSION LEVELS WERE DECREASED IN THE HIPPOCAMPUS OF MICE EXPOSED TO STRESS, WHICH WAS ACCOMPANIED BY BRAIN DYSFUNCTION. WE HAVE SUGGESTED THAT TRANSIENT STRESS REDUCED NPAS4 TRANSCRIPTION THROUGH THE GLUCOCORTICOID RECEPTOR. IN THE PRESENT REPORT, WE INVESTIGATED THE POTENTIAL CONTRIBUTION OF EPIGENETIC MODIFICATIONS INDUCED BY STRESS ON NPAS4 GENE EXPRESSION. THE NPAS4 PROMOTER REGION CONTAINS TWO CPG ISLANDS; IN THE HIPPOCAMPUS, CHRONIC RESTRAINT STRESS INCREASES THE DNA METHYLATION LEVELS OF BOTH OF THESE CPG ISLANDS. IN THE NEURO2A CELL LINE, TREATMENT WITH A DNA METHYLTRANSFERASE INHIBITOR, 5-AZA-2'-DEOXYCYTIDINE, INCREASED NPAS4 MRNA LEVELS AND MARKEDLY REDUCED THE DNA METHYLATION LEVELS OF CPG ISLAND 2 IN THE NPAS4 PROMOTER. THE DNA METHYLATION SITES IN CPG ISLAND 2 OVERLAP WITH TWO CYCLIC ADENOSINE MONOPHOSPHATE RESPONSE ELEMENT (CRE) SEQUENCES. MUTATION OF THESE CRE SEQUENCES REDUCED NPAS4 PROMOTER ACTIVITY. THESE RESULTS SUGGEST THAT TRANSCRIPTION OF THE NPAS4 GENE IS DOWNREGULATED BY STRESS THROUGH DNA METHYLATION OF ITS PROMOTER. 2015 19 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 20 2272 38 EPIGENETIC REDUCTION OF MIR-214-3P UPREGULATES ASTROCYTIC COLONY-STIMULATING FACTOR-1 AND CONTRIBUTES TO NEUROPATHIC PAIN INDUCED BY NERVE INJURY. EMERGING EVIDENCE HAS INDICATED THAT COLONY-STIMULATING FACTOR-1 (CSF1) MODULATES NEUROINFLAMMATION IN THE CENTRAL NERVOUS SYSTEM AND THE DEVELOPMENT OF NEUROPATHIC PAIN, WHILE THE UNDERLYING MECHANISM REMAINS UNKNOWN. HERE, WE IDENTIFIED THE INCREASED EXPRESSION OF CSF1 DERIVED FROM ACTIVATED ASTROCYTES IN THE IPSILATERAL DORSAL HORN IN RATS WITH SPINAL NERVE LIGATION (SNL). SUPPRESSION OF CSF1 EXPRESSION ALLEVIATED NEUROINFLAMMATION, NEURONAL HYPEREXCITABILITY, AND GLUTAMATERGIC RECEPTOR SUBUNIT UPREGULATION IN THE DORSAL HORN AND IMPROVED SNL-INDUCED PAIN BEHAVIOR. WE ALSO FOUND REDUCED MIR-214-3P EXPRESSION IN THE IPSILATERAL DORSAL HORN FOLLOWING AN SNL PROCEDURE; MIR-214-3P DIRECTLY BOUND TO THE 3'-UTR OF CSF1 MRNA AND NEGATIVELY REGULATED CSF1 EXPRESSION. INTRATHECAL DELIVERY OF MIR-214-3P MIMIC REVERSED THE ENHANCED EXPRESSION OF CSF1 AND ASTROCYTE OVERACTIVITY AND ALLEVIATED THE IL-6 UPREGULATION AND PAIN BEHAVIOR INDUCED BY SNL. MOREOVER, SUPPRESSION OF SPINAL MIR-214-3P INCREASED ASTROCYTE REACTIVITY, PROMOTED CSF1 AND IL-6 PRODUCTION, AND INDUCED PAIN HYPERSENSITIVITY IN NAIVE ANIMALS. FURTHERMORE, SNL INDUCED THE EXPRESSION OF DNA METHYLTRANSFERASE 3A (DNMT3A) THAT WAS ASSOCIATED WITH THE HYPERMETHYLATION OF THE MIR-214-3P PROMOTER, LEADING TO REDUCED MIR-214-3P EXPRESSION IN THE MODEL RODENTS. TREATMENT WITH THE DNMT INHIBITOR ZEBULARINE SIGNIFICANTLY REDUCED CYTOSINE METHYLATION IN THE MIR-214-3P PROMOTER; THIS REDUCED METHYLATION CONSEQUENTLY INCREASED THE EXPRESSION OF MIR-214-3P AND DECREASED THE CONTENT OF CSF1 IN THE IPSILATERAL DORSAL HORN AND, FURTHER, ATTENUATED IL-6 PRODUCTION AND PAIN BEHAVIOR IN RATS WITH SNL. TOGETHER, OUR DATA INDICATE THAT THE DNMT3A-MEDIATED EPIGENETIC SUPPRESSION OF MIR-214-3P ENHANCED CSF1 PRODUCTION IN ASTROCYTES, WHICH SUBSEQUENTLY INDUCED NEUROINFLAMMATION AND PAIN BEHAVIOR IN SNL MODEL RATS. 2020