1 4366 134 MIRNA-23A/CXCR4 REGULATES NEUROPATHIC PAIN VIA DIRECTLY TARGETING TXNIP/NLRP3 INFLAMMASOME AXIS. BACKGROUND: CHEMOKINE CXC RECEPTOR 4 (CXCR4) IN SPINAL GLIAL CELLS HAS BEEN IMPLICATED IN NEUROPATHIC PAIN. HOWEVER, THE REGULATORY CASCADES OF CXCR4 IN NEUROPATHIC PAIN REMAIN ELUSIVE. HERE, WE INVESTIGATED THE FUNCTIONAL REGULATORY ROLE OF MIRNAS IN THE PAIN PROCESS AND ITS INTERPLAY WITH CXCR4 AND ITS DOWNSTREAM SIGNALING. METHODS: MIRNAS AND CXCR4 AND ITS DOWNSTREAM SIGNALING MOLECULES WERE MEASURED IN THE SPINAL CORDS OF MICE WITH SCIATIC NERVE INJURY VIA PARTIAL SCIATIC NERVE LIGATION (PSNL). IMMUNOBLOTTING, IMMUNOFLUORESCENCE, IMMUNOPRECIPITATION, AND MAMMAL TWO-HYBRID AND BEHAVIORAL TESTS WERE USED TO EXPLORE THE DOWNSTREAM CXCR4-DEPENDENT SIGNALING PATHWAY. RESULTS: CXCR4 EXPRESSION INCREASED IN SPINAL GLIAL CELLS OF MICE WITH PSNL-INDUCED NEUROPATHIC PAIN. BLOCKING CXCR4 ALLEVIATED THE PAIN BEHAVIOR; CONTRARILY, OVEREXPRESSING CXCR4 INDUCED PAIN HYPERSENSITIVITY. MICRORNA-23A-3P (MIR-23A) DIRECTLY BOUNDS TO 3' UTR OF CXCR4 MRNA. PSNL-INDUCED NEUROPATHIC PAIN SIGNIFICANTLY REDUCED MRNA EXPRESSION OF MIR-23A. OVEREXPRESSION OF MIR-23A BY INTRATHECAL INJECTION OF MIR-23A MIMICS OR LENTIVIRUS REDUCED SPINAL CXCR4 AND PREVENTED PSNL-INDUCED NEUROPATHIC PAIN. IN CONTRAST, KNOCKDOWN OF MIR-23A BY INTRATHECAL INJECTION OF MIR-23A INHIBITOR OR LENTIVIRUS INDUCED PAIN-LIKE BEHAVIOR, WHICH WAS REDUCED BY CXCR4 INHIBITION. ADDITIONALLY, MIR-23A KNOCKDOWN OR CXCR4 OVEREXPRESSION IN NAIVE MICE COULD INCREASE THE THIOREDOXIN-INTERACTING PROTEIN (TXNIP), WHICH WAS ASSOCIATED WITH INDUCTION OF NOD-LIKE RECEPTOR PROTEIN 3 (NLRP3) INFLAMMASOME. INDEED, CXCR4 AND TXNIP WERE CO-EXPRESSED. THE MAMMAL TWO-HYBRID ASSAY REVEALED THE DIRECT INTERACTION BETWEEN CXCR4 AND TXNIP, WHICH WAS INCREASED IN THE SPINAL CORD OF PSNL MICE. IN PARTICULAR, INHIBITION OF TXNIP REVERSED PAIN BEHAVIOR ELICITED BY PSNL, MIR-23A KNOCKDOWN, OR CXCR4 OVEREXPRESSION. MOREOVER, MIR-23A OVEREXPRESSION OR CXCR4 KNOCKDOWN INHIBITED THE INCREASE OF TXNIP AND NLRP3 INFLAMMASOME IN PSNL MICE. CONCLUSIONS: MIR-23A, BY DIRECTLY TARGETING CXCR4, REGULATES NEUROPATHIC PAIN VIA TXNIP/NLRP3 INFLAMMASOME AXIS IN SPINAL GLIAL CELLS. EPIGENETIC INTERVENTIONS AGAINST MIR-23A, CXCR4, OR TXNIP MAY POTENTIALLY SERVE AS NOVEL THERAPEUTIC AVENUES IN TREATING PERIPHERAL NERVE INJURY-INDUCED NOCICEPTIVE HYPERSENSITIVITY. 2018 2 5479 31 RESVERATROL ATTENUATES CIGARETTE SMOKE EXTRACT INDUCED CELLULAR SENESCENCE IN HUMAN AIRWAY EPITHELIAL CELLS BY REGULATING THE MIR-34A/SIRT1/NF-KAPPAB PATHWAY. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS CHARACTERIZED BY ACCELERATED LUNG AGING. SMOKING IS THE CRITICAL RISK FACTOR FOR COPD. CELLULAR SENESCENCE OF AIRWAY EPITHELIAL CELLS IS THE CYTOLOGICAL BASIS OF ACCELERATED LUNG AGING IN COPD, AND THE REGULATION OF MICRORNAS (MIRNAS) IS THE CENTRAL EPIGENETIC MECHANISM OF CELLULAR SENESCENCE. RESVERATROL (RES) IS A POLYPHENOL WITH ANTI-AGING PROPERTIES. THIS STUDY INVESTIGATED WHETHER RES ATTENUATES CIGARETTE SMOKE EXTRACT (CSE)-INDUCED CELLULAR SENESCENCE IN HUMAN AIRWAY EPITHELIAL CELLS (BEAS-2B) THROUGH THE MIR-34A/SIRT1/NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) PATHWAY. BEAS-2B CELLS WERE TREATED WITH RES, CSE AND TRANSFECTED WITH MIR-34A-5P MIMICS. CELLULAR SENESCENCE WAS EVALUATED BY SENESCENCE -RELATED BETA-GALACTOSIDASE (SA-BETA-GAL) STAINING AND EXPRESSION OF SENESCENCE-RELATED GENES (P16, P21, AND P53). THE EXPRESSIONS OF MIR-34A-5P, SIRT1, AND NF-KAPPAB P65 WERE EXAMINED USING QUANTITATIVE REAL TIME POLYMERASE CHAIN REACTION AND WESTERN BLOTTING. THE SENESCENCE-ASSOCIATED SECRETORY PHENOTYPE (SASP) CYTOKINES (IL-1BETA, IL-6, IL-8, TNF-ALPHA) WERE ASSESSED BY ENZYME-LINKED IMMUNOSORBENT ASSAY. THE BINDING BETWEEN MIR-34A-5P AND SIRT1 WAS CONFIRMED BY DUAL-LUCIFERASE REPORTER ASSAY. THE RESULTS SHOWED THAT CSE DOSE-DEPENDENTLY DECREASED CELL VIABILITY AND ELEVATED CELLULAR SENESCENCE, CHARACTERIZED BY INCREASED SA-BETA-GAL STAINING AND SENESCENCE-RELATED GENE EXPRESSIONS (P16, P21, AND P53). FURTHER, CSE DOSE-DEPENDENTLY INCREASED THE EXPRESSION OF MIR-34A-5P AND SASP CYTOKINES (IL-1BETA, IL-6, IL-8, TNF-ALPHA) IN BEAS-2B CELLS. PRETREATMENT WITH RES INHIBITED CSE-INDUCED CELLULAR SENESCENCE AND SECRETION OF SASP CYTOKINES (IL-1BETA, IL-6, IL-8, TNF-ALPHA) IN A DOSE-DEPENDENT MANNER. MOREOVER, RES REVERSED THE CSE-INDUCED DOWN-REGULATION OF SIRT1 AND UP-REGULATION OF MIR-34A-5P AND NF-KAPPAB P65. SIRT1 IS A TARGET OF MIR-34A-5P. OVEREXPRESSION OF MIR-34A-5P VIA TRANSFECTION WITH MIR-34A-5P MIMIC IN BEAS-2B CELLS ATTENUATED THE INHIBITORY EFFECT OF RES ON CELLULAR SENESCENCE, ACCOMPANIED BY REVERSING THE EXPRESSION OF SIRT1 AND NF-KAPPAB P65. IN CONCLUSION, RES ATTENUATED CSE-INDUCED CELLULAR SENESCENCE IN BEAS-2B CELLS BY REGULATING THE MIR-34A/SIRT1/NF-KAPPAB PATHWAY, WHICH MAY PROVIDE A NEW APPROACH FOR COPD TREATMENT. 2022 3 4338 33 MICROVASCULAR BARRIER PROTECTION BY MICRORNA-183 VIA FOXO1 REPRESSION: A PATHWAY DISTURBED IN NEUROPATHY AND COMPLEX REGIONAL PAIN SYNDROME. BLOOD NERVE BARRIER DISRUPTION AND EDEMA ARE COMMON IN NEUROPATHIC PAIN AS WELL AS IN COMPLEX REGIONAL PAIN SYNDROME (CRPS). MICRORNAS (MIRNA) ARE EPIGENETIC MULTITARGET SWITCHES CONTROLLING NEURONAL AND NON-NEURONAL CELLS IN PAIN. THE MIR-183 COMPLEX ATTENUATES HYPEREXCITABILITY IN NOCICEPTORS, BUT ADDITIONAL NON-NEURONAL EFFECTS VIA TRANSCRIPTION FACTORS COULD CONTRIBUTE AS WELL. THIS STUDY EXPLORED EXOSOMAL MIR-183 IN CRPS AND MURINE NEUROPATHY, ITS EFFECT ON THE MICROVASCULAR BARRIER VIA TRANSCRIPTION FACTOR FOXO1 AND TIGHT JUNCTION PROTEIN CLAUDIN-5, AND ITS ANTIHYPERALGESIC POTENTIAL. SCIATIC MIR-183 DECREASED AFTER CCI. SUBSTITUTION WITH PERINEURAL MIR-183 MIMIC ATTENUATED MECHANICAL HYPERSENSITIVITY AND RESTORED BLOOD NERVE BARRIER FUNCTION. IN VITRO, SERUM FROM CCI MICE UND CRPS PATIENTS WEAKENED THE MICROVASCULAR BARRIER OF MURINE CEREBELLAR ENDOTHELIAL CELLS, INCREASED ACTIVE FOXO1 AND REDUCED CLAUDIN-5, CONCOMITANT WITH A LACK OF EXOSOMAL MIR-183 IN CRPS PATIENTS. CELLULAR STRESS ALSO COMPROMISED THE MICROVASCULAR BARRIER WHICH WAS RESCUED EITHER BY MIR-183 MIMIC VIA FOXO1 REPRESSION OR BY PRIOR SILENCING OF FOXO1. PERSPECTIVE: LOW MIR-183 LEADING TO BARRIER IMPAIRMENT VIA FOXO1 AND SUBSEQUENT CLAUDIN-5 SUPPRESSION IS A NEW ASPECT IN THE PATHOPHYSIOLOGY OF CRPS AND NEUROPATHIC PAIN. THIS PATHWAY MIGHT HELP UNTANGLE THE WIDE SYMPTOMATIC RANGE OF CRPS AND NURTURE FURTHER RESEARCH INTO MIRNA MIMICS OR FOXO1 INHIBITORS. 2022 4 4303 36 MICRORNA-223 INHIBITS TISSUE FACTOR EXPRESSION IN VASCULAR ENDOTHELIAL CELLS. OBJECTIVE: ATHEROSCLEROSIS IS A CHRONIC INFLAMMATORY PROCESS, IN WHICH VASCULAR ENDOTHELIAL CELLS (ECS) BECOME DYSFUNCTIONAL OWING TO THE EFFECTS OF CHEMICAL SUBSTANCES, SUCH AS INFLAMMATORY FACTOR AND GROWTH FACTORS. TISSUE FACTOR (TF) EXPRESSION IS INDUCED BY THE ABOVE CHEMICAL SUBSTANCES IN ACTIVATED ECS. TF INITIATES THROMBOSIS ON DISRUPTED ATHEROSCLEROTIC PLAQUES WHICH PLAYS AN ESSENTIAL ROLE DURING THE ONSET OF ACUTE CORONARY SYNDROMES (ACS). INCREASING EVIDENCES SUGGEST THE IMPORTANT ROLE OF MICRORNAS AS EPIGENETIC REGULATORS OF ATHEROSCLEROTIC DISEASE. THE AIM OF OUR STUDY IS TO IDENTIFY IF MICRORNA-223 (MIR-223) TARGETS TF IN ECS. METHODS AND RESULTS: BIOINFORMATIC ANALYSIS SHOWED THAT TF IS A TARGET CANDIDATE OF MIR-223. WESTERN BLOTTING ANALYSIS REVEALED THAT TUMOR NECROSIS FACTOR ALPHA (TNF-ALPHA) INCREASED TF EXPRESSION IN AORTA OF C57BL/6J MICE AND CULTURED ECS (EA.HY926 CELLS AND HUVEC) AFTER 4 H TREATMENT. IN TNF-ALPHA TREATED ECS, TF MRNA WAS ALSO INCREASED MEASURED BY REAL-TIME PCR. REAL-TIME PCR RESULTS SHOWED THAT MIR-223 LEVELS WERE DOWNREGULATED IN TNF-ALPHA-TREATED AORTA OF C57BL/6J MICE AND CULTURED ECS. TRANSFECTION OF ECS WITH MIR-223 MIMIC OR MIR-223 INHIBITOR MODIFIED TF EXPRESSION BOTH IN MRNA AND PROTEIN LEVELS. LUCIFERASE ASSAYS CONFIRMED THAT MIR-223 SUPPRESSED TF EXPRESSION BY BINDING TO THE SEQUENCE OF TF 3'-UNTRANSLATED REGIONS (3'UTR). TF PROCOAGULANT ACTIVITY WAS INHIBITED BY OVEREXPRESSING MIR-223 WITH OR WITHOUT TNF-ALPHA STIMULATION. CONCLUSIONS: MIR-223-MEDIATED SUPPRESSION OF TF EXPRESSION PROVIDES A NOVEL MOLECULAR MECHANISM FOR THE REGULATION OF COAGULATION CASCADE, AND SUGGESTS A CLUE AGAINST THROMBOGENESIS DURING THE PROCESS OF ATHEROSCLEROTIC PLAQUE RUPTURE. 2014 5 3832 32 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 6 4906 41 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 7 2826 31 FLUOXETINE EPIGENETICALLY ALTERS THE CAMKIIALPHA PROMOTER IN NUCLEUS ACCUMBENS TO REGULATE DELTAFOSB BINDING AND ANTIDEPRESSANT EFFECTS. CHRONIC SOCIAL DEFEAT STRESS IN MICE PRODUCES A SUSCEPTIBLE PHENOTYPE CHARACTERIZED BY SEVERAL BEHAVIORAL ABNORMALITIES CONSISTENT WITH HUMAN DEPRESSION THAT ARE REVERSED BY CHRONIC BUT NOT ACUTE EXPOSURE TO ANTIDEPRESSANT MEDICATIONS. RECENT WORK IN ADDICTION MODELS DEMONSTRATES THAT THE TRANSCRIPTION FACTOR DELTAFOSB AND PROTEIN KINASE CALMODULIN-DEPENDENT PROTEIN KINASE II (CAMKII) ARE CO-REGULATED IN NUCLEUS ACCUMBENS (NAC), A BRAIN REWARD REGION IMPLICATED IN BOTH ADDICTION AND DEPRESSION MODELS INCLUDING SOCIAL DEFEAT. PREVIOUS WORK HAS ALSO DEMONSTRATED THAT DELTAFOSB IS INDUCED IN NAC AFTER CHRONIC SOCIAL DEFEAT STRESS OR AFTER CHRONIC ANTIDEPRESSANT TREATMENT, WHEREIN IT MEDIATES A PRO-RESILIENCE OR ANTIDEPRESSANT-LIKE PHENOTYPE. HERE, USING CHROMATIN IMMUNOPRECIPITATION ASSAYS, WE FOUND THAT DELTAFOSB BINDS THE CAMKIIALPHA GENE PROMOTER IN NAC AND THAT THIS BINDING INCREASES AFTER MICE ARE EXPOSED TO CHRONIC SOCIAL DEFEAT STRESS. PARADOXICALLY, CHRONIC EXPOSURE TO THE ANTIDEPRESSANT FLUOXETINE REDUCES BINDING OF DELTAFOSB TO THE CAMKIIALPHA PROMOTER AND REDUCES CAMKII EXPRESSION IN NAC, DESPITE THE FACT THAT DELTAFOSB IS INDUCED UNDER THESE CONDITIONS. THESE DATA SUGGEST A NOVEL EPIGENETIC MECHANISM OF ANTIDEPRESSANT ACTION, WHEREBY FLUOXETINE INDUCES SOME CHROMATIN CHANGE AT THE CAMKIIALPHA PROMOTER, WHICH BLOCKS THE DELTAFOSB BINDING. INDEED, CHRONIC FLUOXETINE REDUCES ACETYLATION AND INCREASES LYSINE-9 DIMETHYLATION OF HISTONE H3 AT THE CAMKIIALPHA PROMOTER IN NAC, EFFECTS ALSO SEEN IN DEPRESSED HUMANS EXPOSED TO ANTIDEPRESSANTS. OVEREXPRESSION OF CAMKII IN NAC BLOCKS FLUOXETINE'S ANTIDEPRESSANT EFFECTS IN THE CHRONIC SOCIAL DEFEAT PARADIGM, WHEREAS INHIBITION OF CAMKII ACTIVITY IN NAC MIMICS FLUOXETINE EXPOSURE. THESE FINDINGS SUGGEST THAT EPIGENETIC SUPPRESSION OF CAMKIIALPHA EXPRESSION IN NAC IS BEHAVIORALLY RELEVANT AND OFFER A NOVEL PATHWAY FOR POSSIBLE THERAPEUTIC INTERVENTION IN DEPRESSION AND RELATED SYNDROMES. 2014 8 6660 43 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 9 5227 32 PRMT6 MEDIATES INFLAMMATION VIA ACTIVATION OF THE NF-KAPPAB/P65 PATHWAY ON A CIGARETTE SMOKE EXTRACT-INDUCED MURINE EMPHYSEMA MODEL. INTRODUCTION: SMOKE-DRIVEN LUNG INFLAMMATION IS CONSIDERED TO BE THE MAJOR PATHOPHYSIOLOGY MECHANISM OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)/EMPHYSEMA. PROTEIN ARGININE METHYLTRANSFERASE 6 (PRMT6) IS A KEY EPIGENETIC ENZYME, WHICH IS RELATED TO PROTECTING THE TRI-METHYLATION OF H3K4 (H3K4ME3). WE HYPOTHESIZED THAT PTMT6 PROTECTS LUNG INFLAMMATION THROUGH THE NUCLEAR FACTOR KAPPA B (NF-KAPPAB) PATHWAY. METHODS: MICE WERE INJECTED WITH CIGARETTE SMOKE EXTRACT (CSE) OR PBS TO ESTABLISH A MICE MODEL, INTRATRACHEALLY INSTILLED WITH OVEREXPRESSED PRMT6 OR NEGATIVE CONTROL VECTOR. MORPHOMETRY OF LUNG SLIDES AND LUNG FUNCTION WERE MEASURED. WE DETERMINED THE PROTEIN EXPRESSION OF PRMT6 AND ITS RELATED HISTONE TARGETS, THE ACTIVATION OF NF-KAPPAB PATHWAY, THE LEVEL OF TUMOR NECROSIS FACTOR ALPHA (TNFALPHA) AND INTERLEUKIN-1BETA (IL-1BETA). RESULTS: AFTER PRMT6 OVEREXPRESSION, THE MORPHOMETRY INDEXES AND LUNG FUNCTION WERE IMPROVED. ALSO, THE EXPRESSION OF H3K4ME3 WAS DECREASED. OVEREXPRESSED PRMT6 COULD SUPPRESS CSE-INDUCED NF-KAPPAB ACTIVATION AND PRO-INFLAMMATION GENES EXPRESSION. CONCLUSIONS: THE OVEREXPRESSED PRMT6 COULD SERVE AS AN INFLAMMATION INHIBITOR, POTENTIALLY THROUGH BLOCKING THE NF-KAPPAB/P65 PATHWAY IN THE MURINE EMPHYSEMA MODEL. 2020 10 1667 28 DOWNREGULATION OF PCAF BY MIR-181A/B PROVIDES FEEDBACK REGULATION TO TNF-ALPHA-INDUCED TRANSCRIPTION OF PROINFLAMMATORY GENES IN LIVER EPITHELIAL CELLS. ABERRANT CELLULAR RESPONSES TO PROINFLAMMATORY CYTOKINES, SUCH AS TNF-ALPHA, ARE PATHOGENIC FEATURES IN MOST CHRONIC INFLAMMATORY DISEASES. A VARIETY OF EXTRACELLULAR AND INTRACELLULAR FEEDBACK PATHWAYS HAS EVOLVED TO PREVENT AN INAPPROPRIATE CELLULAR REACTION TO THESE PROINFLAMMATORY CYTOKINES. IN THIS STUDY, WE REPORT THAT TNF-ALPHA TREATMENT OF HUMAN AND MOUSE CHOLANGIOCYTES AND HEPATOCYTES DOWNREGULATED EXPRESSION OF P300/CBP-ASSOCIATED FACTOR (PCAF), A COACTIVATOR AND AN ACETYLTRANSFERASE THAT PROMOTES HISTONE ACETYLATION AND GENE TRANSCRIPTION. OF THESE UPREGULATED MICRORNAS IN TNF-ALPHA-TREATED CELLS, MIR-181A/B (MIR-181A AND MIR-181B) SUPPRESSED TRANSLATION OF PCAF MRNA. FUNCTIONAL MANIPULATION OF MIR-181A/B CAUSED RECIPROCAL ALTERATIONS IN PCAF PROTEIN EXPRESSION IN CULTURED CHOLANGIOCYTES AND HEPATOCYTES. INHIBITION OF MIR-181A/B FUNCTION WITH ANTI-MIRS BLOCKED TNF-ALPHA-INDUCED SUPPRESSION OF PCAF EXPRESSION. PROMOTER RECRUITMENT OF PCAF WAS SHOWN TO BE ASSOCIATED WITH TNF-ALPHA-INDUCED TRANSCRIPTION OF INFLAMMATORY GENES. INTRIGUINGLY, PRETREATMENT OF CELLS WITH TNF-ALPHA INHIBITED TRANSCRIPTION OF INFLAMMATORY GENES IN RESPONSE TO SUBSEQUENT TNF-ALPHA STIMULATION. OVEREXPRESSION OF PCAF OR INHIBITION OF MIR-181A/B FUNCTION WITH ANTI-MIRS ATTENUATED THE INHIBITORY EFFECTS OF TNF-ALPHA PRETREATMENT ON EPITHELIAL INFLAMMATORY RESPONSE TO SUBSEQUENT TNF-ALPHA STIMULATION. DOWNREGULATION OF PCAF AND THE INHIBITORY EFFECTS OF TNF-ALPHA PRETREATMENT ON LIVER EPITHELIAL INFLAMMATORY RESPONSE WERE FURTHER CONFIRMED IN A MOUSE MODEL OF TNF-ALPHA I.P. INJECTION. THESE DATA SUGGEST THAT PCAF IS A TARGET FOR MIR-181A/B, AND DOWNREGULATION OF PCAF BY TNF-ALPHA PROVIDES NEGATIVE FEEDBACK REGULATION TO INFLAMMATORY REACTIONS IN LIVER EPITHELIAL CELLS, A PROCESS THAT MAY BE RELEVANT TO THE EPIGENETIC FINE-TUNING OF EPITHELIAL INFLAMMATORY PROCESSES IN GENERAL. 2012 11 5574 39 ROLE OF MICRORNA-143 IN NERVE INJURY-INDUCED UPREGULATION OF DNMT3A EXPRESSION IN PRIMARY SENSORY NEURONS. PERIPHERAL NERVE INJURY INCREASED THE EXPRESSION OF THE DNA METHYLTRANSFERASE 3A (DNMT3A) MRNA AND ITS ENCODING DNMT3A PROTEIN IN INJURED DORSAL ROOT GANGLIA (DRG). THIS INCREASE IS CONSIDERED AS AN ENDOGENOUS INSTIGATOR IN NEUROPATHIC PAIN GENESIS THROUGH EPIGENETIC SILENCING OF PAIN-ASSOCIATED GENES (SUCH AS OPRM1) IN INJURED DRG. HOWEVER, HOW DRG DNMT3A IS INCREASED FOLLOWING PERIPHERAL NERVE INJURY IS STILL ELUSIVE. WE REPORTED HERE THAT PERIPHERAL NERVE INJURY CAUSED BY THE FIFTH SPINAL NERVE LIGATION (SNL) DOWNREGULATED MICRORNA (MIR)-143 EXPRESSION IN INJURED DRG. THIS DOWNREGULATION WAS REQUIRED FOR SNL-INDUCED DRG DNMT3A INCREASE AS RESCUING MIR-143 DOWNREGULATION THROUGH MICROINJECTION OF MIR-143 MIMICS INTO INJURED DRG BLOCKED THE SNL-INDUCED INCREASE IN DNMT3A AND RESTORED THE SNL-INDUCED DECREASES IN OPRM1 MRNA AND ITS ENCODING MU OPIOID RECEPTOR (MOR) IN INJURED DRG, IMPAIRED SPINAL CORD CENTRAL SENSITIZATION AND NEUROPATHIC PAIN, AND IMPROVED MORPHINE ANALGESIC EFFECTS FOLLOWING SNL. MIMICKING SNL-INDUCED DRG MIR-143 DOWNREGULATION THROUGH DRG MICROINJECTION OF MIR143 INHIBITORS IN NAIVE RATS INCREASED THE EXPRESSION OF DNMT3A AND REDUCED THE EXPRESSION OF OPRM1 MRNA AND MOR IN INJECTED DRG AND PRODUCED NEUROPATHIC PAIN-LIKE SYMPTOMS. THESE FINDINGS SUGGEST THAT MIR-143 IS A NEGATIVE REGULATOR IN DNMT3A EXPRESSION IN THE DRG UNDER NEUROPATHIC PAIN CONDITIONS AND MAY BE A POTENTIAL TARGET FOR THERAPEUTIC MANAGEMENT OF NEUROPATHIC PAIN. 2017 12 2300 35 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 13 5402 39 REDUCTION OF SIRT1-MEDIATED EPIGENETIC UPREGULATION OF NAV1.7 CONTRIBUTES TO OXALIPLATIN-INDUCED NEUROPATHIC PAIN. BACKGROUND: CLINICALLY, NEUROPATHIC PAIN IS A SEVERE SIDE EFFECT OF OXALIPLATIN CHEMOTHERAPY, WHICH USUALLY LEADS TO DOSE REDUCTION OR CESSATION OF TREATMENT. DUE TO THE UNAWARENESS OF DETAILED MECHANISMS OF OXALIPLATIN-INDUCED NEUROPATHIC PAIN, IT IS DIFFICULT TO DEVELOP AN EFFECTIVE THERAPY AND LIMITS ITS CLINICAL USE. OBJECTIVES: THE AIM OF THE PRESENT STUDY WAS TO IDENTIFY THE ROLE OF SIRTUIN 1 (SIRT1) REDUCTION IN EPIGENETIC REGULATION OF THE EXPRESSION OF VOLTAGE-GATED SODIUM CHANNELS 1.7 (NAV1.7) IN THE DORSAL ROOT GANGLION (DRG) DURING OXALIPLATIN-INDUCED NEUROPATHIC PAIN. STUDY DESIGN: CONTROLLED ANIMAL STUDY. SETTING: UNIVERSITY LABORATORY. METHODS: THE VON FREY TEST WAS PERFORMED TO EVALUATE PAIN BEHAVIOR IN RATS. REAL-TIME QUANTITATIVE POLYMERASE CHAIN REACTION, WESTERN BLOTTING, ELECTROPHYSIOLOGICAL RECORDING, CHROMATIN IMMUNOPRECIPITATION, AND SMALL INTERFERING RNA (SIRNA) WERE USED TO ILLUSTRATE THE MECHANISMS. RESULTS: IN THE PRESENT STUDY, WE FOUND THAT BOTH THE ACTIVITY AND EXPRESSION OF SIRT1 WERE SIGNIFICANTLY DECREASED IN RAT DRG FOLLOWING OXALIPLATIN TREATMENT. THE ACTIVATOR OF SIRT1, RESVERATROL, NOT ONLY INCREASED THE ACTIVITY AND EXPRESSION OF SIRT1, BUT ALSO ATTENUATED THE MECHANICAL ALLODYNIA FOLLOWING OXALIPLATIN TREATMENT. IN ADDITION, LOCAL KNOCKDOWN OF SIRT1 BY INTRATHECAL INJECTION OF SIRT1 SIRNA CAUSED MECHANICAL ALLODYNIA IN NAIVE RATS. BESIDES, OXALIPLATIN TREATMENT ENHANCED THE ACTION POTENTIAL FIRING FREQUENCY OF DRG NEURONS AND THE EXPRESSION OF NAV1.7 IN DRG AND ACTIVATION OF SIRT1 BY RESVERATROL REVERSED THIS EFFECT. FURTHERMORE, BLOCKING NAV1.7 BY PROTX II (A SELECTIVE NAV1.7 CHANNEL BLOCKER) REVERSED OXALIPLATIN-INDUCED MECHANICAL ALLODYNIA. IN ADDITION, HISTONE H3 HYPERACETYLATION AT THE NAV1.7 PROMOTER IN DRG OF RATS FOLLOWING OXALIPLATIN TREATMENT WAS SIGNIFICANTLY SUPPRESSED BY ACTIVATION OF SIRT1 WITH RESVERATROL. MOREOVER, BOTH THE EXPRESSION OF NAV1.7 AND HISTONE H3 ACETYLATION AT THE NAV1.7 PROMOTER WERE UPREGULATED IN THE DRG BY LOCAL KNOCKDOWN OF SIRT1 WITH SIRT1 SIRNA IN NAIVE RATS. LIMITATIONS: MORE UNDERLYING MECHANISM(S) OF SIRT1 REDUCTION AFTER OXALIPLATIN TREATMENT NEEDS TO BE EXPLORED IN FUTURE RESEARCH. CONCLUSIONS: THESE FINDINGS SUGGEST THAT REDUCTION OF SIRT1-MEDIATED EPIGENETIC UPREGULATION OF NAV1.7 IN THE DRG CONTRIBUTES TO THE DEVELOPMENT OF OXALIPLATIN-INDUCED NEUROPATHIC PAIN IN RATS. THE INTRATHECAL DRUG DELIVERY TREATMENT OF ACTIVATING SIRT1 MIGHT BE A NOVEL THERAPEUTIC OPTION FOR OXALIPLATIN-INDUCED NEUROPATHIC PAIN. 2023 14 1826 33 EFFECTS OF HISTONE DEACETYLASE INHIBITOR ON EXTRACELLULAR MATRIX PRODUCTION IN HUMAN NASAL POLYP ORGAN CULTURES. BACKGROUND: NASAL POLYPOSIS IS ASSOCIATED WITH A CHRONIC INFLAMMATORY CONDITION OF THE SINONASAL MUCOSA AND INVOLVES MYOFIBROBLAST DIFFERENTIATION AND EXTRACELLULAR MATRIX (ECM) ACCUMULATION. EPIGENETIC MODULATION BY HISTONE DEACETYLASE (HDAC) INHIBITORS INCLUDING TRICHOSTATIN A (TSA) HAS BEEN REPORTED TO HAVE INHIBITORY EFFECTS ON MYOFIBROBLAST DIFFERENTIATION IN LUNG AND RENAL FIBROBLASTS. THE PURPOSE OF THIS STUDY WAS TO INVESTIGATE THE INHIBITORY EFFECT OF TSA ON MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION IN NASAL POLYP ORGAN CULTURES. METHODS: NASAL POLYP TISSUES FROM 18 PATIENTS WERE ACQUIRED DURING ENDOSCOPIC SINUS SURGERY. AFTER ORGAN CULTURE, NASAL POLYPS WERE STIMULATED WITH TGF-BETA1 AND THEN TREATED WITH TSA. ALPHA-SMOOTH MUSCLE ACTIN (ALPHA-SMA), FIBRONECTIN, AND COLLAGEN TYPE I EXPRESSION LEVELS WERE EXAMINED BY REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION (PCR), REAL-TIME PCR, WESTERN BLOT, AND IMMUNOFLUORESCENT STAINING. HDAC2, HDAC4, AND ACETYLATED H4 EXPRESSION LEVELS WERE ASSAYED BY WESTERN BLOT. CYTOTOXICITY WAS ANALYZED BY THE TERMINAL DEOXYNUCLEOTIDYL TRANSFERASE BIOTIN-DUTP NICK END LABELING ASSAY. RESULTS: THE EXPRESSION LEVELS OF ALPHA-SMA, FIBRONECTIN, AND COLLAGEN TYPE 1 WERE INCREASED IN NASAL POLYP AFTER TRANSFORMING GROWTH FACTOR (TGF) BETA1 TREATMENT. TSA-INHIBITED TGF-BETA1 INDUCED THESE GENE AND PROTEIN EXPRESSION LEVELS. FURTHERMORE, TSA SUPPRESSED PROTEIN EXPRESSION LEVELS OF HDAC2 AND HDAC4. HOWEVER, TSA INDUCED HYPERACETYLATION OF HISTONES H4. TREATMENT WITH TGF-BETA1 WITH OR WITHOUT TSA DID NOT HAVE CYTOTOXIC EFFECT. CONCLUSION: THESE FINDINGS PROVIDE NOVEL INSIGHTS INTO THE EPIGENETIC REGULATION IN MYOFIBROBLAST DIFFERENTIATION AND ECM PRODUCTION OF NASAL POLYP. TSA COULD BE A CANDIDATE OF A THERAPEUTIC AGENT FOR REVERSING THE TGF-BETA1-INDUCED ECM SYNTHESIS THAT LEADS TO NASAL POLYP DEVELOPMENT. 2013 15 1105 33 COMBINED INHIBITION OF HISTONE DEACETYLASES AND BET FAMILY PROTEINS AS EPIGENETIC THERAPY FOR NERVE INJURY-INDUCED NEUROPATHIC PAIN. CURRENT TREATMENTS FOR NEUROPATHIC PAIN HAVE OFTEN MODERATE EFFICACY AND PRESENT UNWANTED EFFECTS SHOWING THE NEED TO DEVELOP EFFECTIVE THERAPIES. ACCUMULATING EVIDENCE SUGGESTS THAT HISTONE ACETYLATION PLAYS ESSENTIAL ROLES IN CHRONIC PAIN AND THE ANALGESIC ACTIVITY OF HISTONE DEACETYLASES (HDACS) INHIBITORS IS DOCUMENTED. BROMODOMAIN AND EXTRA-TERMINAL DOMAIN (BET) PROTEINS ARE EPIGENETIC READERS THAT INTERACT WITH ACETYLATED LYSINE RESIDUES ON HISTONES, BUT LITTLE IS KNOWN ABOUT THEIR IMPLICATION IN NEUROPATHIC PAIN. THUS, THE CURRENT STUDY WAS AIMED TO INVESTIGATE THE EFFECT OF THE COMBINATION OF HDAC AND BET INHIBITORS IN THE SPARED NERVE INJURY (SNI) MODEL IN MICE. INTRANASAL ADMINISTRATION OF I-BET762 (BET INHIBITOR) OR SAHA (HDAC INHIBITOR) ATTENUATED THERMAL AND MECHANICAL HYPERSENSITIVITY AND THIS ANTIALLODYNIC ACTIVITY WAS IMPROVED BY CO-ADMINISTRATION OF BOTH DRUGS. SPINAL CORD SECTIONS OF SNI MICE SHOWED AN INCREASED EXPRESSION OF HDAC1 AND BRD4 PROTEINS AND COMBINATION PRODUCED A STRONGER REDUCTION COMPARED TO EACH EPIGENETIC AGENT ALONE. SAHA AND I-BET762, ADMINISTERED ALONE OR IN COMBINATION, COUNTERACTED THE SNI-INDUCED MICROGLIA ACTIVATION BY INHIBITING THE EXPRESSION OF IBA1, CD11B, INDUCIBLE NITRIC OXIDE SYNTHASE (INOS), THE ACTIVATION OF NUCLEAR FACTOR-KAPPAB (NF-KAPPAB) AND SIGNAL TRANSDUCER AND ACTIVATOR OF TRANSCRIPTION-1 (STAT1) WITH COMPARABLE EFFICACY. CONVERSELY, THE EPIGENETIC INHIBITORS SHOWED A MODEST EFFECT ON SPINAL PROINFLAMMATORY CYTOKINES CONTENT THAT WAS SIGNIFICANTLY POTENTIATED BY THEIR COMBINATION. PRESENT RESULTS INDICATE A KEY ROLE OF ACETYLATED HISTONES AND THEIR RECRUITMENT BY BET PROTEINS ON MICROGLIA-MEDIATED SPINAL NEUROINFLAMMATION. TARGETING NEUROPATHIC PAIN WITH THE COMBINATION OF HDAC AND BET INHIBITORS MAY REPRESENT A PROMISING NEW THERAPEUTIC OPTION. 2021 16 2353 31 EPIGENETIC REGULATION OF OPIOID-INDUCED HYPERALGESIA, DEPENDENCE, AND TOLERANCE IN MICE. REPEATED ADMINISTRATION OF OPIOIDS SUCH AS MORPHINE INDUCES PERSISTENT BEHAVIORAL CHANGES INCLUDING OPIOID-INDUCED HYPERALGESIA (OIH), TOLERANCE, AND PHYSICAL DEPENDENCE. IN THE CURRENT WORK WE EXPLORED HOW THE BALANCE OF HISTONE ACETYLTRANSFERASE (HAT) VERSUS HISTONE DEACETYLASE (HDAC) MIGHT REGULATE THESE MORPHINE-INDUCED CHANGES. NOCICEPTIVE THRESHOLDS, ANALGESIA, AND PHYSICAL DEPENDENCE WERE ASSESSED DURING AND FOR A PERIOD OF SEVERAL WEEKS AFTER MORPHINE EXPOSURE. TO PROBE THE ROLES OF HISTONE ACETYLATION, THE HAT INHIBITOR CURCUMIN OR A SELECTIVE HDAC INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) WAS ADMINISTERED DAILY TO GROUPS OF ANIMALS. HISTONE ACETYLATION IN SPINAL CORD WAS ASSESSED BY WESTERN BLOT AND IMMUNOHISTOCHEMISTRY. CONCURRENT ADMINISTRATION OF CURCUMIN WITH MORPHINE FOR 4 DAYS SIGNIFICANTLY REDUCED DEVELOPMENT OF OPIOID-INDUCED MECHANICAL ALLODYNIA, THERMAL HYPERALGESIA, TOLERANCE, AND PHYSICAL DEPENDENCE. CONVERSELY, THE HDAC INHIBITOR SAHA ENHANCED THESE RESPONSES. INTERESTINGLY, SAHA TREATMENT AFTER THE TERMINATION OF OPIOID ADMINISTRATION SUSTAINED THESE BEHAVIORAL CHANGES FOR AT LEAST 4 WEEKS. HISTONE H3 ACETYLATION IN THE DORSAL HORN OF THE SPINAL CORD WAS INCREASED AFTER CHRONIC MORPHINE TREATMENT, BUT H4 ACETYLATION WAS UNCHANGED. MOREOVER, WE OBSERVED A DECREASE IN HDAC ACTIVITY IN THE SPINAL CORDS OF MORPHINE-TREATED MICE WHILE OVERALL HAT ACTIVITY WAS UNCHANGED, SUGGESTING A SHIFT TOWARD A STATE OF ENHANCED HISTONE ACETYLATION. PERSPECTIVE: THE CURRENT STUDY INDICATES THAT EPIGENETIC MECHANISMS PLAY A CRUCIAL ROLE IN OPIOID-INDUCED LONG-LASTING NEUROPLASTICITY. THESE RESULTS PROVIDE NEW SIGHT INTO UNDERSTANDING THE MECHANISMS OF OPIOID-INDUCED NEUROPLASTICITY AND SUGGEST NEW STRATEGIES TO LIMIT OPIOID ABUSE POTENTIAL AND INCREASE THE VALUE OF THESE DRUGS AS ANALGESICS. 2013 17 3324 40 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 18 4160 34 MECP2 EPIGENETIC SILENCING OF OPRM1 GENE IN PRIMARY SENSORY NEURONS UNDER NEUROPATHIC PAIN CONDITIONS. OPIOIDS ARE THE LAST OPTION FOR THE PHARMACOLOGICAL TREATMENT OF NEUROPATHIC PAIN, BUT THEIR ANTINOCICEPTIVE EFFECTS ARE LIMITED. DECREASED MU OPIOID RECEPTOR (MOR) EXPRESSION IN THE PERIPHERAL NERVOUS SYSTEM MAY CONTRIBUTE TO THIS. HERE, WE SHOWED THAT NERVE INJURY INDUCED HYPERMETHYLATION OF THE OPRM1 GENE PROMOTER AND AN INCREASED EXPRESSION OF METHYL-CPG BINDING PROTEIN 2 (MECP2) IN INJURED DORSAL ROOT GANGLION (DRG). THE DOWNREGULATION OF MOR IN THE DRG IS CLOSELY RELATED TO THE AUGMENTATION OF MECP2, AN EPIGENETIC REPRESSOR, WHICH COULD RECRUIT HDAC1 AND BIND TO THE METHYLATED REGIONS OF THE OPRM1 GENE PROMOTER. MECP2 KNOCKDOWN RESTORED THE EXPRESSION OF MOR IN INJURED DRG AND ENHANCED THE ANALGESIC EFFECT OF MORPHINE, WHILE THE MIMICKING OF THIS INCREASE VIA THE INTRATHECAL INFUSION OF VIRAL VECTOR-MEDIATED MECP2 WAS SUFFICIENT TO REDUCE MOR IN THE DRG. MOREOVER, HDAC1 INHIBITION WITH SUBEROYLANILIDE HYDROXAMIC ACID, AN HDAC INHIBITOR, ALSO PREVENTED MOR REDUCTION IN THE DRG OF NEUROPATHIC PAIN MICE, CONTRIBUTING TO THE AUGMENTATION OF MORPHINE ANALGESIA EFFECTS. MECHANISTICALLY, UPREGULATED MECP2 PROMOTES THE BINDING OF A HIGH LEVEL OF HDCA1 TO HYPERMETHYLATED REGIONS OF THE OPRM1 GENE PROMOTER, REDUCES THE ACETYLATION OF HISTONE H3 (ACH3) LEVELS OF THE OPRM1 GENE PROMOTER, AND ATTENUATES OPRM1 TRANSCRIPTION IN INJURED DRG. THUS, UPREGULATED MECP2 AND HDAC1 IN OPRM1 GENE PROMOTER SITES, NEGATIVELY REGULATES MOR EXPRESSION IN INJURED DRG, MITIGATING THE ANALGESIC EFFECT OF THE OPIOIDS. TARGETING MECP2/HDAC1 MAY THUS PROVIDE A NEW SOLUTION FOR IMPROVING THE THERAPEUTIC EFFECT OF OPIOIDS IN A CLINICAL SETTING. 2021 19 1631 45 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 20 1800 22 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