1 212 132 ACUPUNCTURE ALLEVIATES CHRONIC PAIN AND COMORBID CONDITIONS IN A MOUSE MODEL OF NEUROPATHIC PAIN: THE INVOLVEMENT OF DNA METHYLATION IN THE PREFRONTAL CORTEX. CHRONIC PAIN REDUCES LIFE QUALITY AND IS AN IMPORTANT CLINICAL PROBLEM ASSOCIATED WITH EMOTIONAL AND COGNITIVE DYSFUNCTION. EPIGENETIC REGULATION OF DNA METHYLATION IS INVOLVED IN THE INDUCTION OF ABNORMAL BEHAVIORS AND PATHOLOGICAL GENE EXPRESSION. WE EXAMINED WHETHER ACUPUNCTURE CAN RESTORE EPIGENETIC CHANGES CAUSED BY CHRONIC PAIN, AND IDENTIFIED THE UNDERLYING MECHANISMS IN NEUROPATHIC PAIN MICE. ACUPUNCTURE TREATMENT FOR 6 MONTHS (3 DAYS/WEEK) IMPROVED MECHANICAL/COLD ALLODYNIA AND THE EMOTIONAL/COGNITIVE DYSFUNCTION CAUSED BY LEFT PARTIAL SCIATIC NERVE LIGATION (PSNL)-INDUCED NEUROPATHIC PAIN. THE EFFECTS OF ACUPUNCTURE WERE ASSOCIATED WITH GLOBAL DNA METHYLATION RECOVERY IN THE PREFRONTAL CORTEX (PFC). ANALYSIS OF DNA METHYLATION PATTERNS IN PFC INDICATED THAT 1364 OVERLAPPING GENES AMONG 4442 AND 4416 METHYLATED GENES IN THE PSNL VS SHAM AND PSNL VS ACUPUNCTURE POINTS GROUPS, RESPECTIVELY, WERE HIGHLY ASSOCIATED WITH THE DNA METHYLATION PROCESS. ACUPUNCTURE RESTORED THE REDUCED EXPRESSION OF 5-METHYLCYTOSINE, METHYL-CYTOSINE-PHOSPHO-GUANINE BINDING PROTEIN 2, AND DNA METHYLTRANSFERASE FAMILY ENZYMES INDUCED BY PSNL IN PFC. METHYLATION LEVELS OF NR4A1 AND CHKB ASSOCIATED WITH MITOCHONDRIAL DYSFUNCTION WERE DECREASED IN PFC OF THE PSNL MICE, AND INCREASED BY ACUPUNCTURE. BY CONTRAST, HIGH EXPRESSION OF NR4A1 AND CHKB MRNA IN PSNL MICE DECREASED AFTER ACUPUNCTURE. WE ALSO FOUND THAT ACUPUNCTURE INHIBITED THE EXPRESSION OF RAS PATHWAY-RELATED GENES SUCH AS RASGRP1 AND RASSF1. FINALLY, THE EXPRESSION OF NR4A1, RASGRP1, RASSF1, AND CHKB MRNA INCREASED IN THE NEURONAL CELLS TREATED WITH MECP2 SMALL INTERFERING RNA. THESE RESULTS SUGGEST THAT ACUPUNCTURE CAN RELIEVE CHRONIC PAIN-INDUCED COMORBID CONDITIONS BY ALTERING DNA METHYLATION OF NR4A1, RASGRP1, RASSF1, AND CHKB IN THE PFC. 2021 2 6875 21 [PROGRESS OF RESEARCHES ON ANTI-INFLAMMATORY MECHANISM OF ACUPUNCTURE UNDERLYING AMELIORATION OF CHRONIC RESPIRATORY DISEASES]. IN RECENT YEARS, ACUPUNCTURE HAS GAINED GREAT PROGRESS IN THE TREATMENT OF CHRONIC RESPIRATORY DISEASES (CRD), AND THE CLINICAL EFFECT IS REMARKABLE, BUT ITS UNDERLYING MECHANISMS ARE RELATIVELY COMPLEX, WITH THE ANTI-INFLAMMATORY EFFECT BEING THE PRIMARY ASPECT. BASED ON THE LITERATURE BOTH AT HOME AND ABROAD, WE FOUND THAT THE ANTI-INFLAMMATORY MECHANISM OF ACUPUNCTURE MAINLY INVOLVES CHEMOKINES, KINASE-RELATED PATHWAYS, HELPER T CELLS, EPIGENETIC MODIFICATION, AUTOPHAGY, VAGAL-MEDIATED CHOLINERGIC ANTI-INFLAMMATORY PATHWAY, ETC. THE RESEARCHES ON SOME ANTI-INFLAMMATORY MECHANISMS ARE STILL IN THE INITIAL STAGE, THE RELATIONSHIP AMONG VARIOUS PATHWAYS, AND THE KEY FACTORS AFFECTING THE EFFECT OF ACUPUNCTURE, SUCH AS ACUPOINT SELECTION, STIMULATION INTENSITY AND NEEDLING DEPTH, ETC. WARRANT FURTHER EXPLORATION IN THE FUTURE. 2023 3 2175 26 EPIGENETIC MECHANISMS OF ANGIOGENESIS IN THE ISCHEMIC HEART DISEASES WITH ACUPUNCTURE TREATMENT. OBJECTIVE: EPIGENETICS, INCLUDING DNA METHYLATION, HISTONE MODIFICATION, AND POSTTRANSCRIPTIONAL REGULATION OF MICRORNAS, IS THE STUDY OF HERITABLE CHANGES IN GENE EXPRESSION THAT DO NOT INCLUDE DNA-SEQUENCE ALTERATIONS. EPIGENETICS HAS BECOME A NEW STRATEGY FOR BASIC AND CLINICAL RESEARCH ON ACUPUNCTURE IN THE LAST DECADE. THE AIM OF THIS RESEARCH UPDATE WAS TO SUMMARIZE THE EPIGENETIC MECHANISMS OF ANGIOGENESIS INDUCED BY ACUPUNCTURE TREATMENT IN ISCHEMIC HEART DISEASES. MATERIALS AND METHODS: THE CURRENT AUTHORS' GROUP HAS BEEN WORKING TO ILLUSTRATE THE MECHANISM OF ACUPUNCTURE FROM AN EPIGENETICS PERSPECTIVE, WHICH HAS SHED NEW LIGHTS ON THE MECHANISMS AND APPLICATIONS OF ACUPUNCTURE IN CARDIOVASCULAR DISEASES. THIS ARTICLE SUMMARIZES THE GROUP'S NEW FINDINGS IN ANIMAL MODELS AS WELL AS IN PATIENTS WITH CHRONIC STABLE ANGINA. PROGRESS SINCE 2011 IN OTHER TEAMS' RESEARCH IN THIS FIELD IS ALSO DISCUSSED IN THIS ARTICLE. CONCLUSIONS: ACUPUNCTURE COULD REGULATE HISTONE MODIFICATIONS AND COULD RESCUE PATIENTS WHO SUSTAIN ISCHEMIC INJURIES. THIS TREATMENT COULD POSSIBLY WORK THROUGH PROMOTING ANGIOGENESIS. 2020 4 6240 31 THE MANUAL STIMULATION OF ACUPUNCTURE POINTS IN THE TREATMENT OF POST-TRAUMATIC STRESS DISORDER: A REVIEW OF CLINICAL EMOTIONAL FREEDOM TECHNIQUES. BACKGROUND: THE MANUAL STIMULATION OF ACUPUNCTURE POINTS HAS BEEN COMBINED WITH COMPONENTS OF COGNITIVE AND EXPOSURE THERAPIES INTO A CLINICAL AND SELF-HELP APPROACH KNOWN AS EMOTIONAL FREEDOM TECHNIQUES (EFT). MORE THAN 40 CLINICAL TRIALS AND FOUR META-ANALYTIC REVIEWS OF EFT TREATMENTS HAVE DEMONSTRATED LARGE EFFECT SIZES WITH A RANGE OF CONDITIONS, INCLUDING PAIN, PTSD (IN BOTH CIVILIAN AND MILITARY VETERAN POPULATIONS), PHOBIAS, ANXIETY, AND DEPRESSION. OBJECTIVE: THIS REVIEW DESCRIBES THE APPROACH, WITH A FOCUS ON PTSD IN VETERANS AND SERVICE MEMBERS, PROVIDES AN OVERVIEW OF HOW EFT IS MOST COMMONLY APPLIED, AND OUTLINES OBSTACLES AND CAUTIONS RELATED TO ITS IMPLEMENTATION. METHODS: PEER-REVIEWED CLINICAL TRIALS AND META-ANALYSES OF EFT IN THE TREATMENT OF PTSD ARE ASSESSED TO IDENTIFY THE CHARACTERISTICS OF THE APPROACH THAT RENDER IT SUITABLE FOR THE TREATMENT OF PTSD. RESULTS: THE LITERATURE DEMONSTRATES THAT REMEDIATION OF PTSD AND COMORBID CONDITIONS IS TYPICALLY ACCOMPLISHED WITHIN BRIEF TIME FRAMES, RANGING FROM ONE SESSION FOR PHOBIAS TO BETWEEN FOUR AND TEN SESSIONS FOR PTSD. CLINICAL EFT HAS BEEN SHOWN TO REGULATE STRESS HORMONES AND LIMBIC FUNCTION AND TO IMPROVE VARIOUS NEUROLOGIC MARKERS OF GENERAL HEALTH. THE EPIGENETIC EFFECTS OF EFT INCLUDE UPREGULATION OF IMMUNITY GENES AND DOWNREGULATION OF INFLAMMATION GENES. SIX DISMANTLING STUDIES HAVE INDICATED THAT THE ACUPRESSURE COMPONENT OF EFT IS AN ACTIVE INGREDIENT AND NOT PLACEBO. CONCLUSIONS: SEVEN EMPIRICALLY SUPPORTED STRENGTHS OF THE APPROACH WERE IDENTIFIED THAT MAKE IT ESPECIALLY SUITABLE FOR USE WITH VETERANS AND ACTIVE MILITARY: (1) THE DEPTH AND BREADTH OF TREATMENT EFFECTS; (2) THE RELATIVELY BRIEF TIMEFRAMES REQUIRED FOR SUCCESSFUL TREATMENT; (3) THE LOW RISK OF ADVERSE EVENTS; (4) THE MINIMAL TRAINING TIME REQUIRED FOR THE APPROACH TO BE APPLIED EFFECTIVELY; (5) THE SIMULTANEOUS REDUCTION OF PHYSICAL AND PSYCHOLOGIC SYMPTOMS; (6) THE UTILITY AND COST-EFFECTIVENESS OF CLINICAL EFT IN A LARGE GROUP FORMAT; AND (7) THE METHOD'S ADAPTABILITY TO ONLINE AND TELEMEDICINE APPLICATIONS. 2017 5 1851 41 ELECTROACUPUNCTURE INDUCES BILATERAL S1 AND ACC EPIGENETIC REGULATION OF GENES IN A MOUSE MODEL OF NEUROPATHIC PAIN. CLINICAL AND ANIMAL STUDIES HAVE SHOWN THAT ACUPUNCTURE MAY BENEFIT CONTROLLING NEUROPATHIC PAIN. HOWEVER, THE UNDERLYING MOLECULAR MECHANISMS ARE POORLY UNDERSTOOD. IN A WELL-ESTABLISHED MOUSE UNILATERAL TIBIAL NERVE INJURY (TNI) MODEL, WE CONFIRMED THE EFFICACY OF ELECTROACUPUNCTURE (EA) IN REDUCING MECHANICAL ALLODYNIA AND MEASURED METHYLATION AND HYDROXY-METHYLATION LEVELS IN THE PRIMARY SOMATOSENSORY CORTEX (S1) AND ANTERIOR CINGULATE CORTEX (ACC), TWO CORTICAL REGIONS CRITICALLY INVOLVED IN PAIN PROCESSING. TNI RESULTED IN INCREASED DNA METHYLATION OF BOTH THE CONTRA- AND IPSILATERAL S1, WHILE EA ONLY REDUCED CONTRALATERAL S1 METHYLATION. RNA SEQUENCING OF THE S1 AND ACC IDENTIFIED DIFFERENTIALLY EXPRESSED GENES RELATED TO ENERGY METABOLISM, INFLAMMATION, SYNAPSE FUNCTION, AND NEURAL PLASTICITY AND REPAIR. ONE WEEK OF DAILY EA DECREASED OR INCREASED THE MAJORITY OF UP- OR DOWNREGULATED GENES, RESPECTIVELY, IN BOTH CORTICAL REGIONS. VALIDATIONS OF TWO GREATLY REGULATED GENES WITH IMMUNOFLUORESCENT STAINING REVEALED AN INCREASED EXPRESSION OF GEPHYRIN IN THE IPSILATERAL S1 AFTER TNI WAS DECREASED BY EA; WHILE TNI-INDUCED INCREASES IN TOMM20, A BIOMARKER OF MITOCHONDRIA, IN THE CONTRALATERAL ACC WERE FURTHER ENHANCED AFTER EA. WE CONCLUDED THAT NEUROPATHIC PAIN IS ASSOCIATED WITH DIFFERENTIAL EPIGENETIC REGULATIONS OF GENE EXPRESSION IN THE ACC AND S1 AND THAT THE ANALGESIC EFFECT OF EA MAY INVOLVE REGULATING CORTICAL GENE EXPRESSION. 2023 6 6730 27 WALK MORE, EAT LESS, DON'T STRESS. UNHEALTHY DIET, OBESITY, LACK OF PHYSICAL ACTIVITY, AND PSYCHOLOGIC STRESS ARE ASSOCIATED WITH INCREASED INFLAMMATION, OXIDATIVE STRESS, INSULIN RESISTANCE, AND DNA METHYLATION, WHICH ARE THE MAIN MECHANISMS OF CHRONIC DISEASES SUCH AS CANCER, HYPERTENSION, DIABETES, CARDIOVASCULAR DISEASE, AND ALZHEIMER'S DISEASE. IT HAS RECENTLY BEEN FOUND THAT HEALTHY DIET AND PHYSICAL ACTIVITY CAN REDUCE INFLAMMATORY MARKERS AND IMPROVE INSULIN SENSITIVITY RESULTING IN BETTER SURVIVORSHIP OUTCOMES IN PATIENTS WITH PROSTATE CANCER. AN "ANTI-INFLAMMATORY" LIFESTYLE, INCLUDING PHYSICAL ACTIVITY, HEALTHY BODY WEIGHT, HEALTHY DIET, AND STRESS REDUCTION, HAS BEEN ASSOCIATED WITH DECREASED CANCER RISK AND PROGRESSION. EPIGENETIC CHANGES DUE TO DNA METHYLATION AND ALTERED GENE EXPRESSION ASSOCIATED WITH UNHEALTHY LIFESTYLE CAN BE MODULATED BY HEALTHY BEHAVIORS. NATIONAL CENTER FOR COMPLEMENTARY AND INTEGRATIVE HEALTH (NCCIH) FOCUSES ON HEALTHY LIFESTYLE, AND IT SUPPORTS RESEARCH ON PSYCHOLOGIC AND PHYSICAL APPROACHES INCLUDING DIETARY SUPPLEMENTS AND PLANT-BASED PRODUCTS, AS WELL AS MIND AND BODY APPROACHES, SUCH AS YOGA, MASSAGE, MEDITATION, MINDFULNESS-BASED STRESS REDUCTION, AND ACUPUNCTURE. SEE RELATED ARTICLE BY LANGLAIS ET AL., P. 1760. 2022 7 5354 36 RE1-SILENCING TRANSCRIPTION FACTOR CONTROLS THE ACUTE-TO-CHRONIC NEUROPATHIC PAIN TRANSITION AND CHRM2 RECEPTOR GENE EXPRESSION IN PRIMARY SENSORY NEURONS. NEUROPATHIC PAIN IS ASSOCIATED WITH PERSISTENT CHANGES IN GENE EXPRESSION IN PRIMARY SENSORY NEURONS, BUT THE UNDERLYING EPIGENETIC MECHANISMS THAT CAUSE THESE CHANGES REMAIN UNCLEAR. THE MUSCARINIC CHOLINERGIC RECEPTORS (MACHRS), PARTICULARLY THE M2 SUBTYPE (ENCODED BY THE CHOLINERGIC RECEPTOR MUSCARINIC 2 (CHRM2) GENE), ARE CRITICALLY INVOLVED IN THE REGULATION OF SPINAL NOCICEPTIVE TRANSMISSION. HOWEVER, LITTLE IS KNOWN ABOUT HOW CHRM2 EXPRESSION IS TRANSCRIPTIONALLY REGULATED. HERE WE SHOW THAT NERVE INJURY PERSISTENTLY INCREASED THE EXPRESSION OF RE1-SILENCING TRANSCRIPTION FACTOR (REST, ALSO KNOWN AS NEURON-RESTRICTIVE SILENCING FACTOR [NRSF]), A GENE-SILENCING TRANSCRIPTION FACTOR, IN THE DORSAL ROOT GANGLION (DRG). REMARKABLY, NERVE INJURY-INDUCED CHRONIC BUT NOT ACUTE PAIN HYPERSENSITIVITY WAS ATTENUATED IN MICE WITH REST KNOCKOUT IN DRG NEURONS. ALSO, SIRNA-MEDIATED REST KNOCKDOWN REVERSED NERVE INJURY-INDUCED CHRONIC PAIN HYPERSENSITIVITY IN RATS. NERVE INJURY PERSISTENTLY REDUCED CHRM2 EXPRESSION IN THE DRG AND DIMINISHED THE ANALGESIC EFFECT OF MUSCARINE. THE RE1 BINDING SITE ON THE CHRM2 PROMOTER IS REQUIRED FOR REST-MEDIATED CHRM2 REPRESSION, AND NERVE INJURY INCREASED THE ENRICHMENT OF REST IN THE CHRM2 PROMOTER IN THE DRG. FURTHERMORE, REST KNOCKDOWN OR GENETIC ABLATION IN DRG NEURONS NORMALIZED CHRM2 EXPRESSION AND AUGMENTED MUSCARINE'S ANALGESIC EFFECT ON NEUROPATHIC PAIN AND FULLY REVERSED THE NERVE INJURY-INDUCED REDUCTION IN THE INHIBITORY EFFECT OF MUSCARINE ON GLUTAMATERGIC INPUT TO SPINAL DORSAL HORN NEURONS. OUR FINDINGS INDICATE THAT NERVE INJURY-INDUCED REST UP-REGULATION IN DRG NEURONS PLAYS AN IMPORTANT ROLE IN THE ACUTE-TO-CHRONIC PAIN TRANSITION AND IS ESSENTIAL FOR THE TRANSCRIPTIONAL REPRESSION OF CHRM2 IN NEUROPATHIC PAIN. 2018 8 1167 31 CONTRIBUTION OF DORSAL ROOT GANGLION OCTAMER TRANSCRIPTION FACTOR 1 TO NEUROPATHIC PAIN AFTER PERIPHERAL NERVE INJURY. NEUROPATHIC PAIN GENESIS IS RELATED TO GENE ALTERATIONS IN THE DORSAL ROOT GANGLION (DRG) AFTER PERIPHERAL NERVE INJURY. TRANSCRIPTION FACTORS CONTROL GENE EXPRESSION. IN THIS STUDY, WE INVESTIGATED WHETHER OCTAMER TRANSCRIPTION FACTOR 1 (OCT1), A TRANSCRIPTION FACTOR, CONTRIBUTED TO NEUROPATHIC PAIN CAUSED BY CHRONIC CONSTRICTION INJURY (CCI) OF THE SCIATIC NERVE. CHRONIC CONSTRICTION INJURY PRODUCED A TIME-DEPENDENT INCREASE IN THE LEVEL OF OCT1 PROTEIN IN THE IPSILATERAL L4/5 DRG, BUT NOT IN THE SPINAL CORD. BLOCKING THIS INCREASE THROUGH MICROINJECTION OF OCT1 SIRNA INTO THE IPSILATERAL L4/5 DRG ATTENUATED THE INITIATION AND MAINTENANCE OF CCI-INDUCED MECHANICAL ALLODYNIA, HEAT HYPERALGESIA, AND COLD ALLODYNIA AND IMPROVED MORPHINE ANALGESIA AFTER CCI, WITHOUT AFFECTING BASAL RESPONSES TO ACUTE MECHANICAL, HEAT, AND COLD STIMULI AS WELL AS LOCOMOTOR FUNCTIONS. MIMICKING THIS INCREASE THROUGH MICROINJECTION OF RECOMBINANT ADENO-ASSOCIATED VIRUS 5 HARBORING FULL-LENGTH OCT1 INTO THE UNILATERAL L4/5 DRG LED TO MARKED MECHANICAL ALLODYNIA, HEAT HYPERALGESIA, AND COLD ALLODYNIA IN NAIVE RATS. MECHANISTICALLY, OCT1 PARTICIPATED IN CCI-INDUCED INCREASES IN DNMT3A MRNA AND ITS PROTEIN AND DNMT3A-MEDIATED DECREASES IN OPRM1 AND KCNA2 MRNAS AND THEIR PROTEINS IN THE INJURED DRG. THESE FINDINGS INDICATE THAT OCT1 MAY PARTICIPATE IN NEUROPATHIC PAIN AT LEAST IN PART BY TRANSCRIPTIONALLY ACTIVATING DNMT3A AND SUBSEQUENTLY EPIGENETIC SILENCING OF OPRM1 AND KCAN2 IN THE DRG. OCT1 MAY SERVE AS A POTENTIAL TARGET FOR THERAPEUTIC TREATMENTS AGAINST NEUROPATHIC PAIN. 2019 9 2475 35 EPIGENETIC UP-REGULATION OF ADAMTS4 IN SYMPATHETIC GANGLIA IS INVOLVED IN THE MAINTENANCE OF NEUROPATHIC PAIN FOLLOWING NERVE INJURY. SYMPATHETIC AXONAL SPROUTING INTO DORSAL ROOT GANGLIA IS A MAJOR PHENOMENON IMPLICATED IN NEUROPATHIC PAIN, AND SYMPATHETIC GANGLIA BLOCKAGE MAY RELIEVE SOME INTRACTABLE CHRONIC PAIN IN ANIMAL PAIN MODELS AND CLINICAL CONDITIONS. THESE SUGGEST THAT SYMPATHETIC GANGLIA PARTICIPATED IN THE MAINTENANCE OF CHRONIC PAIN. HOWEVER, THE MOLECULAR MECHANISM UNDERLYING SYMPATHETIC GANGLIA-MEDIATED CHRONIC PAIN IS NOT CLEAR. HERE, WE FOUND THAT SPARED NERVE INJURY TREATMENT UPREGULATED THE EXPRESSION OF ADAMTS4 AND AP-2ALPHA PROTEIN AND MRNA IN THE NORADRENERGIC NEURONS OF SYMPATHETIC GANGLIA DURING NEUROPATHIC PAIN MAINTENANCE. KNOCKDOWN THE ADAMTS4 OR AP-2ALPHA BY INJECTING SPECIFIC RETRO SCAAV-TH (TYROSINE HYDROXYLASE)-SHRNA AMELIORATED THE MECHANICAL ALLODYNIA INDUCED BY SPARED NERVE INJURY ON DAY 21 AND 28. FURTHERMORE, CHROMATIN IMMUNOPRECIPITATION AND COIMMUNOPRECIPITATION ASSAYS FOUND THAT SPARED NERVE INJURY INCREASED THE RECRUITMENT OF AP-2ALPHA TO THE ADAMTS4 GENE PROMOTER, THE INTERACTION BETWEEN AP-2ALPHA AND HISTONE ACETYLTRANSFERASE P300 AND THE HISTONE H4 ACETYLATION ON DAY 28. FINALLY, KNOCKDOWN THE AP-2ALPHA REDUCED THE ACETYLATION OF H4 ON THE PROMOTER REGION OF ADAMTS4 GENE AND SUPPRESSED THE INCREASE OF ADAMTS4 EXPRESSION INDUCED BY SPARED NERVE INJURY. TOGETHER, THESE RESULTS SUGGESTED THAT THE ENHANCED INTERACTION BETWEEN AP-2ALPHA AND P300 MEDIATED THE EPIGENETIC UPREGULATION OF ADAMTS4 IN SYMPATHETIC GANGLIA NORADRENERGIC NEURONS, WHICH CONTRIBUTED TO THE MAINTENANCE OF SPARED NERVE INJURY INDUCED NEUROPATHIC PAIN. 2023 10 3368 35 HISTONE METHYLTRANSFERASE G9A DIMINISHES EXPRESSION OF CANNABINOID CB(1) RECEPTORS IN PRIMARY SENSORY NEURONS IN NEUROPATHIC PAIN. TYPE 1 CANNABINOID RECEPTORS (CB(1)RS) ARE EXPRESSED IN THE DORSAL ROOT GANGLION (DRG) AND CONTRIBUTE TO THE ANALGESIC EFFECT OF CANNABINOIDS. HOWEVER, THE EPIGENETIC MECHANISM REGULATING THE EXPRESSION OF CB(1)RS IN NEUROPATHIC PAIN IS UNKNOWN. G9A (ENCODED BY THE EHMT2 GENE), A HISTONE 3 AT LYSINE 9 METHYLTRANSFERASE, IS A KEY CHROMATIN REGULATOR RESPONSIBLE FOR GENE SILENCING. IN THIS STUDY, WE DETERMINED G9A'S ROLE IN REGULATING CB(1)R EXPRESSION IN THE DRG AND IN CB(1)R-MEDIATED ANALGESIC EFFECTS IN AN ANIMAL MODEL OF NEUROPATHIC PAIN. WE SHOW THAT NERVE INJURY PROFOUNDLY REDUCED MRNA LEVELS OF CB(1)RS BUT INCREASED THE EXPRESSION OF CB(2) RECEPTORS IN THE RAT DRG. CHIP RESULTS INDICATED INCREASED ENRICHMENT OF HISTONE 3 AT LYSINE 9 DIMETHYLATION, A G9A-CATALYZED REPRESSIVE HISTONE MARK, AT THE PROMOTER REGIONS OF THE CB(1)R GENES. G9A INHIBITION IN NERVE-INJURED RATS NOT ONLY UP-REGULATED THE CB(1)R EXPRESSION LEVEL IN THE DRG BUT ALSO POTENTIATED THE ANALGESIC EFFECT OF A CB(1)R AGONIST ON NERVE INJURY-INDUCED PAIN HYPERSENSITIVITY. FURTHERMORE, IN MICE LACKING EHMT2 IN DRG NEURONS, NERVE INJURY FAILED TO REDUCE CB(1)R EXPRESSION IN THE DRG AND TO DECREASE THE ANALGESIC EFFECT OF THE CB(1)R AGONIST. MOREOVER, NERVE INJURY DIMINISHED THE INHIBITORY EFFECT OF THE CB(1)R AGONIST ON SYNAPTIC GLUTAMATE RELEASE FROM PRIMARY AFFERENT NERVES TO SPINAL CORD DORSAL HORN NEURONS IN WT MICE BUT NOT IN MICE LACKING EHMT2 IN DRG NEURONS. OUR FINDINGS REVEAL THAT NERVE INJURY DIMINISHES THE ANALGESIC EFFECT OF CB(1)R AGONISTS THROUGH G9A-MEDIATED CB(1)R DOWN-REGULATION IN PRIMARY SENSORY NEURONS. 2020 11 5692 25 SILENCING OF LNCRNA PKIA-AS1 ATTENUATES SPINAL NERVE LIGATION-INDUCED NEUROPATHIC PAIN THROUGH EPIGENETIC DOWNREGULATION OF CDK6 EXPRESSION. NEUROPATHIC PAIN (NP) IS AMONG THE MOST INTRACTABLE COMORBIDITIES OF SPINAL CORD INJURY. DYSREGULATION OF NON-CODING RNAS HAS ALSO BEEN IMPLICATED IN THE DEVELOPMENT OF NEUROPATHIC PAIN. HERE, WE IDENTIFIED A NOVEL LNCRNA, PKIA-AS1, BY USING LNCRNA ARRAY ANALYSIS IN SPINAL CORD TISSUE OF SPINAL NERVE LIGATION (SNL) MODEL RATS, AND INVESTIGATED THE ROLE OF PKIA-AS1 IN SNL-MEDIATED NEUROPATHIC PAIN. WE OBSERVED THAT PKIA-AS1 WAS SIGNIFICANTLY UPREGULATED IN SNL MODEL RATS AND THAT PKIA-AS1 KNOCKDOWN ATTENUATED NEUROPATHIC PAIN PROGRESSION. ALTERNATIVELY, OVEREXPRESSION OF PKIA-AS1 WAS SUFFICIENT TO INDUCE NEUROPATHIC PAIN-LIKE SYMPTOMS IN UNINJURED RATS. WE ALSO FOUND THAT PKIA-AS1 MEDIATED SNL-INDUCED NEUROPATHIC PAIN BY DIRECTLY REGULATING THE EXPRESSION AND FUNCTION OF CDK6, WHICH IS ESSENTIAL FOR THE INITIATION AND MAINTENANCE OF NEUROINFLAMMATION AND NEUROPATHIC PAIN. THEREFORE, OUR STUDY IDENTIFIES PKIA-AS1 AS A NOVEL THERAPEUTIC TARGET FOR NEUROINFLAMMATION RELATED NEUROPATHIC PAIN. 2019 12 4919 30 PANNEXIN-1 UP-REGULATION IN THE DORSAL ROOT GANGLION CONTRIBUTES TO NEUROPATHIC PAIN DEVELOPMENT. PANNEXIN-1 (PANX1) IS A LARGE-PORE MEMBRANE CHANNEL INVOLVED IN THE RELEASE OF ATP AND OTHER SIGNALING MEDIATORS. LITTLE IS KNOWN ABOUT THE EXPRESSION AND FUNCTIONAL ROLE OF PANX1 IN THE DORSAL ROOT GANGLION (DRG) IN THE DEVELOPMENT OF CHRONIC NEUROPATHIC PAIN. IN THIS STUDY, WE DETERMINED THE EPIGENETIC MECHANISM INVOLVED IN INCREASED PANX1 EXPRESSION IN THE DRG AFTER NERVE INJURY. SPINAL NERVE LIGATION IN RATS SIGNIFICANTLY INCREASED THE MRNA AND PROTEIN LEVELS OF PANX1 IN THE DRG BUT NOT IN THE SPINAL CORD. IMMUNOCYTOCHEMICAL LABELING SHOWED THAT PANX1 WAS PRIMARILY EXPRESSED IN A SUBSET OF MEDIUM AND LARGE DRG NEURONS IN CONTROL RATS AND THAT NERVE INJURY MARKEDLY INCREASED THE NUMBER OF PANX1-IMMUNOREACTIVE DRG NEURONS. NERVE INJURY SIGNIFICANTLY INCREASED THE ENRICHMENT OF TWO ACTIVATING HISTONE MARKS (H3K4ME2 AND H3K9AC) AND DECREASED THE OCCUPANCY OF TWO REPRESSIVE HISTONE MARKS (H3K9ME2 AND H3K27ME3) AROUND THE PROMOTER REGION OF PANX1 IN THE DRG. HOWEVER, NERVE INJURY HAD NO EFFECT ON THE DNA METHYLATION LEVEL AROUND THE PANX1 PROMOTER IN THE DRG. FURTHERMORE, INTRATHECAL INJECTION OF THE PANX1 BLOCKERS OR PANX1-SPECIFIC SIRNA SIGNIFICANTLY REDUCED PAIN HYPERSENSITIVITY INDUCED BY NERVE INJURY. IN ADDITION, SIRNA KNOCKDOWN OF PANX1 EXPRESSION IN A DRG CELL LINE SIGNIFICANTLY REDUCED CASPASE-1 RELEASE INDUCED BY NEURONAL DEPOLARIZATION. OUR FINDINGS SUGGEST THAT NERVE INJURY INCREASES PANX1 EXPRESSION LEVELS IN THE DRG THROUGH ALTERED HISTONE MODIFICATIONS. PANX1 UP-REGULATION CONTRIBUTES TO THE DEVELOPMENT OF NEUROPATHIC PAIN AND STIMULATION OF INFLAMMASOME SIGNALING. 2015 13 4637 27 NEURON-RESTRICTIVE SILENCER FACTOR CAUSES EPIGENETIC SILENCING OF KV4.3 GENE AFTER PERIPHERAL NERVE INJURY. PERIPHERAL NERVE INJURY CAUSES A VARIETY OF ALTERATIONS IN PAIN-RELATED GENE EXPRESSION IN PRIMARY AFFERENT, WHICH UNDERLIE THE NEURONAL PLASTICITY IN NEUROPATHIC PAIN. ONE OF THE CHARACTERISTIC ALTERATIONS IS A LONG-LASTING DOWNREGULATION OF VOLTAGE-GATED POTASSIUM (K(V)) CHANNEL, INCLUDING K(V)4.3, IN THE DORSAL ROOT GANGLION (DRG). THE PRESENT STUDY SHOWED THAT NERVE INJURY REDUCES THE MESSENGER RNA (MRNA) EXPRESSION LEVEL OF K(V)4.3 GENE, WHICH CONTAINS A CONSERVED NEURON-RESTRICTIVE SILENCER ELEMENT (NRSE), A BINDING SITE FOR NEURON-RESTRICTIVE SILENCER FACTOR (NRSF). MOREOVER, WE FOUND THAT INJURY CAUSES AN INCREASE IN DIRECT NRSF BINDING TO K(V)4.3-NRSE IN THE DRG, USING CHROMATIN IMMUNOPRECIPITATION (CHIP) ASSAY. CHIP ASSAY FURTHER REVEALED THAT ACETYLATION OF HISTONE H4, BUT NOT H3, AT K(V)4.3-NRSE IS MARKEDLY REDUCED AT DAY 7 POST-INJURY. FINALLY, THE INJURY-INDUCED K(V)4.3 DOWNREGULATION WAS SIGNIFICANTLY BLOCKED BY ANTISENSE-KNOCKDOWN OF NRSF. TAKEN TOGETHER, THESE DATA SUGGEST THAT NERVE INJURY CAUSES AN EPIGENETIC SILENCING OF K(V)4.3 GENE MEDIATED THROUGH TRANSCRIPTIONAL SUPPRESSOR NRSF IN THE DRG. 2010 14 2450 34 EPIGENETIC SUPPRESSION OF LIVER X RECEPTOR BETA IN ANTERIOR CINGULATE CORTEX BY HDAC5 DRIVES CFA-INDUCED CHRONIC INFLAMMATORY PAIN. BACKGROUND: LIVER X RECEPTORS (LXRS), INCLUDING LXRALPHA AND LXRBETA, ARE KEY REGULATORS OF TRANSCRIPTIONAL PROGRAMS FOR BOTH CHOLESTEROL HOMEOSTASIS AND INFLAMMATION IN THE BRAIN. HERE, THE MODES OF ACTION OF LXRS AND THE EPIGENETIC MECHANISMS REGULATING LXRBETA EXPRESSION IN ANTERIOR CINGULATE CORTEX (ACC) OF CHRONIC INFLAMMATORY PAIN (CIP) ARE INVESTIGATED. METHODS: THE DEFICIT OF LXR ISOFORM AND ANALGESIC EFFECT OF LXR ACTIVATION BY GW3965 WERE EVALUATED USING THE MOUSE MODEL OF CIP INDUCED BY HINDPAW INJECTION OF COMPLETE FREUND'S ADJUVANT (CFA). THE MECHANISMS INVOLVED IN GW-MEDIATED ANALGESIC EFFECTS WERE ANALYZED WITH IMMUNOHISTOCHEMICAL METHODS, ELISA, CO-IMMUNOPRECIPITATION (CO-IP), WESTERN BLOT, AND ELECTROPHYSIOLOGICAL RECORDING. THE EPIGENETIC REGULATION OF LXRBETA EXPRESSION WAS INVESTIGATED BY CHROMATIN IMMUNOPRECIPITATION, QUANTITATIVE REAL-TIME PCR, AND SEQUENCING. RESULTS: WE REVEALED THAT CFA INSULT LED TO LXRBETA REDUCTION IN ACC, WHICH WAS ASSOCIATED WITH UPREGULATED EXPRESSION OF HISTONE DEACETYLASE 5 (HDAC5), AND KNOCKDOWN OF LXRBETA BY SHRNA LED TO THERMAL HYPERALGESIA. CO-IP SHOWED THAT LXRBETA INTERACTED WITH NF-KAPPAB P65 PHYSICALLY. LXRBETA ACTIVATION BY GW3965 EXERTED ANALGESIC EFFECTS BY INHIBITING THE NUCLEAR TRANSLOCATION OF NF-KAPPAB, REDUCING THE PHOSPHORYLATION OF MITOGEN-ACTIVATED PROTEIN KINASES (MAPKS) IN ACC, AND DECREASING THE PROMOTED INPUT-OUTPUT AND ENHANCED MEPSC FREQUENCY IN ACC NEURONS AFTER CFA EXPOSURE. IN VITRO EXPERIMENTS CONFIRMED THAT HDAC5 TRIGGERED HISTONE DEACETYLATION ON THE PROMOTER REGION OF LXRBETA, RESULTING IN DOWNREGULATION OF LXRBETA TRANSCRIPTION. CONCLUSION: THESE FINDINGS HIGHLIGHT AN EPIGENETIC MECHANISM UNDERLYING LXRBETA DEFICITS LINKED TO CIP, AND LXRBETA ACTIVATION MAY REPRESENT A POTENTIAL NOVEL TARGET FOR THE TREATMENT OF CIP WITH AN ALTERATION IN INFLAMMATION RESPONSES AND SYNAPTIC TRANSMISSION IN ACC. 2019 15 2112 26 EPIGENETIC GENE SILENCING UNDERLIES C-FIBER DYSFUNCTIONS IN NEUROPATHIC PAIN. PERIPHERAL NERVE INJURY CAUSES NEUROPATHIC PAIN, WHICH IS CHARACTERIZED BY THE PARADOXICAL SENSATIONS OF POSITIVE AND NEGATIVE SYMPTOMS. CLINICALLY, NEGATIVE SIGNS ARE FREQUENTLY OBSERVED; HOWEVER, THEIR UNDERLYING MOLECULAR MECHANISMS ARE LARGELY UNKNOWN. DYSFUNCTION OF C-FIBERS IS ASSUMED TO UNDERLIE NEGATIVE SYMPTOMS AND IS ACCOMPANIED BY LONG-LASTING DOWNREGULATION OF NA(V)1.8 SODIUM CHANNEL AND MU-OPIOID RECEPTOR (MOP) IN THE DORSAL ROOT GANGLION (DRG). IN THE PRESENT STUDY, WE FOUND THAT NERVE INJURY UPREGULATES NEURON-RESTRICTIVE SILENCER FACTOR (NRSF) EXPRESSION IN THE DRG NEURONS MEDIATED THROUGH EPIGENETIC MECHANISMS. IN ADDITION, CHROMATIN IMMUNOPRECIPITATION ANALYSIS REVEALED THAT NERVE INJURY PROMOTES NRSF BINDING TO THE NEURON-RESTRICTIVE SILENCER ELEMENT WITHIN MOP AND NA(V)1.8 GENES, THEREBY CAUSING EPIGENETIC SILENCING. FURTHERMORE, NRSF KNOCKDOWN SIGNIFICANTLY BLOCKED NERVE INJURY-INDUCED DOWNREGULATIONS OF MOP AND NA(V)1.8 GENE EXPRESSIONS, C-FIBER HYPOESTHESIA, AND THE LOSSES OF PERIPHERAL MORPHINE ANALGESIA AND NA(V)1.8-SELECTIVE BLOCKER-INDUCED HYPOESTHESIA. TOGETHER, THESE DATA SUGGEST THAT NRSF CAUSES PATHOLOGICAL AND PHARMACOLOGICAL DYSFUNCTION OF C-FIBERS, WHICH UNDERLIES THE NEGATIVE SYMPTOMS IN NEUROPATHIC PAIN. 2010 16 815 28 CHANGES IN THE EXPRESSION OF INFLAMMATORY AND EPIGENETIC-MODULATORY GENES AFTER AN INTENSIVE MEDITATION RETREAT. BACKGROUND: MEDITATION RETREATS ARE CHARACTERIZED BY INTENSIVE OR CONCENTRATED PERIODS OF MEDITATION PRACTICE, COMMONLY UNDERTAKEN IN A RESIDENTIAL SETTING. ALTHOUGH RESEARCH INDICATES THAT MEDITATION TRAINING CAN POSITIVELY INFLUENCE PHYSICAL AND MENTAL HEALTH OUTCOMES, THE BIOLOGICAL CONSEQUENCES OF MEDITATION RETREAT INTERVENTIONS ARE RELATIVELY UNDERSTUDIED. IN THIS STUDY, WE EXAMINED THE INFLUENCE OF A MONTH-LONG, SILENT MEDITATION RETREAT ON THE EXPRESSION OF GENES INVOLVED IN EPIGENETIC MODULATION AND IMMUNE PROCESSES. METHOD: WE ASSESSED GENE EXPRESSION CHANGES IN EXPERIENCED MEDITATORS ATTENDING A MONTH-LONG INSIGHT MEDITATION RETREAT (N = 28), AS COMPARED TO A COMMUNITY CONTROL GROUP (N = 34) OF EXPERIENCED PRACTITIONERS LIVING THEIR EVERYDAY LIVES. BLOOD SAMPLES WERE COLLECTED ON DAY TWO OF THE RETREAT (TIME 1) AND AGAIN 3 WEEKS LATER (TIME 2). CONTROL PARTICIPANTS WERE ALSO ASSESSED ACROSS A 3-WEEK INTERVAL, DURING WHICH THEY MAINTAINED THEIR REGULAR DAILY ROUTINES. RESULTS: AS COMPARED TO CONTROLS, RETREAT PARTICIPANTS SHOWED DIFFERENTIAL CHANGES IN THE EXPRESSION OF SEVERAL GENES INVOLVED IN CHROMATIN MODULATION AND INFLAMMATION. THE MOST SUBSTANTIVE FINDING WAS DOWNREGULATION OF THE TNF PATHWAY IN RETREAT PARTICIPANTS, WHICH WAS NOT OBSERVED IN CONTROLS. CONCLUSIONS: THESE FINDINGS INDICATE THAT MEDITATION RETREAT PARTICIPATION MAY INFLUENCE SOME OF THE INFLAMMATORY MECHANISMS INVOLVED IN THE DEVELOPMENT OF CHRONIC DISEASES, AND THAT THIS STYLE OF PSYCHOSOCIAL INTERVENTION MAY HAVE THERAPEUTIC POTENTIAL, PARTICULARLY IN EXPERIENCED PRACTITIONERS. 2022 17 6156 17 THE GENETIC INFLUENCE ON THE CORTICAL PROCESSING OF EXPERIMENTAL PAIN AND THE MODERATING EFFECT OF PAIN STATUS. BACKGROUND: RESEARCH SUGGESTS THAT THE COMT VAL(158)MET, BDNF VAL(66)MET AND OPRM1 A(118)G POLYMORPHISMS MODERATE THE EXPERIENCE OF PAIN. IN ORDER TO OBTAIN EXPERIMENTAL CONFIRMATION AND EXTENSION OF FINDINGS, CORTICAL PROCESSING OF EXPERIMENTALLY-INDUCED PAIN WAS USED. METHOD: A SAMPLE OF 78 INDIVIDUALS WITH CHRONIC LOW BACK PAIN COMPLAINTS AND 37 HEALTHY CONTROLS UNDERWENT EEG REGISTRATION. EVENT-RELATED POTENTIALS WERE MEASURED IN RESPONSE TO ELECTRICAL NOCICEPTIVE STIMULI AND MODERATION BY COMT VAL(158)MET, BDNF VAL(66)MET AND OPRM1 A(118)G POLYMORPHISMS WAS ASSESSED. RESULTS: GENETIC VARIATION DID NOT HAVE A DIRECT EFFECT ON CORTICAL PROCESSING OF EXPERIMENTAL PAIN. HOWEVER, GENETIC EFFECTS (COMT VAL(158)MET AND BDNF VAL(66)MET) ON EXPERIMENTAL PAIN WERE MODERATED BY THE PRESENCE OF CHRONIC PAIN. IN THE PRESENCE OF CHRONIC PAIN, THE COMT MET ALLELE AND THE BDNF MET ALLELE AUGMENTED CORTICAL PAIN PROCESSING, WHILST REDUCING PAIN PROCESSING IN PAIN-FREE CONTROLS. NO SIGNIFICANT EFFECTS WERE FOUND CONCERNING THE OPRM1 A(118)G POLYMORPHISM. CONCLUSIONS: THE CURRENT STUDY SUGGESTS THAT CHRONIC EXPERIENCE OF PAIN ENHANCES GENETIC SENSITIVITY TO EXPERIMENTALLY INDUCED MILDLY PAINFUL STIMULI, POSSIBLY THROUGH A PROCESS OF EPIGENETIC MODIFICATION. 2010 18 2006 31 EPIGENETIC AUGMENTATION OF THE MACROPHAGE INFLAMMATORY PROTEIN 2/C-X-C CHEMOKINE RECEPTOR TYPE 2 AXIS THROUGH HISTONE H3 ACETYLATION IN INJURED PERIPHERAL NERVES ELICITS NEUROPATHIC PAIN. ALTHOUGH THERE IS GROWING EVIDENCE SHOWING THAT THE INVOLVEMENT OF CHEMOKINES IN THE PATHOGENESIS OF NEUROPATHIC PAIN IS ASSOCIATED WITH NEUROINFLAMMATION, THE DETAILS ARE UNCLEAR. WE INVESTIGATED THE C-X-C CHEMOKINE LIGAND TYPE 2 [MACROPHAGE INFLAMMATORY PROTEIN 2 (MIP-2)]/C-X-C CHEMOKINE RECEPTOR TYPE 2 (CXCR2) AXIS AND EPIGENETIC REGULATION OF THESE MOLECULES IN NEUROPATHIC PAIN AFTER PERIPHERAL NERVE INJURY. EXPRESSION OF MIP-2 AND CXCR2 WERE UP-REGULATED AND LOCALIZED ON ACCUMULATED NEUTROPHILS AND MACROPHAGES IN THE INJURED SCIATIC NERVE (SCN) AFTER PARTIAL SCIATIC NERVE LIGATION (PSL). PERINEURAL INJECTION OF MIP-2-NEUTRALIZING ANTIBODY (ANTI-MIP-2) OR THE CXCR2 ANTAGONIST N-(2-BROMOPHENYL)-N'-(2-HYDROXY-4-NITROPHENYL)UREA (SB225002) PREVENTED PSL-INDUCED TACTILE ALLODYNIA AND THERMAL HYPERALGESIA. PERINEURAL INJECTION OF RECOMBINANT MIP-2 ELICITED NEUROPATHIC PAIN-LIKE BEHAVIORS. ANTI-MIP-2 SUPPRESSED NEUTROPHIL ACCUMULATION IN THE SCN AFTER PSL. NEUTROPHIL DEPLETION BY INTRAPERITONEAL INJECTION OF LY6G ANTIBODY ATTENUATED PSL-INDUCED NEUROPATHIC PAIN. BOTH ANTI-MIP-2 AND SB225002 SUPPRESSED UP-REGULATION OF INFLAMMATORY CYTOKINES AND CHEMOKINES IN THE INJURED SCN. IN ADDITION, ACETYLATION OF HISTONE H3 [LYSINE (LYS9)-ACETYLATED HISTONE H3 (ACK9-H3)] ON THE PROMOTER REGION OF MIP-2 AND CXCR2 WAS INCREASED IN THE INJURED SCN AFTER PSL. EXPRESSION OF ACK9-H3 WAS OBSERVED IN THE NUCLEI OF NEUTROPHILS AND MACROPHAGES SURROUNDING THE EPINEURIUM. ADMINISTRATION OF THE HISTONE ACETYLTRANSFERASE INHIBITOR ANACARDIC ACID SUPPRESSED THE UP-REGULATION OF MIP-2 AND CXCR2 IN THE SCN AFTER PSL AND RESULTED IN THE PREVENTION OF PSL-INDUCED NEUROPATHIC PAIN. TAKEN TOGETHER, THESE RESULTS SHOW THAT AUGMENTATION OF THE MIP-2/CXCR2 AXIS BY HYPERACETYLATION OF HISTONE H3 ON THE PROMOTER REGION OF MIP-2 AND CXCR2 LOCATED IN THE INJURED PERIPHERAL NERVE ELICITS CHRONIC NEUROINFLAMMATION THROUGH NEUTROPHIL ACCUMULATION, LEADING TO NEUROPATHIC PAIN. 2012 19 78 24 A NEW MECHANISTIC APPROACH FOR THE TREATMENT OF CHRONIC NEUROPATHIC PAIN WITH NITROUS OXIDE INTEGRATED FROM A SYSTEMS BIOLOGY NARRATIVE REVIEW. THE LIMITATIONS OF THE CURRENTLY AVAILABLE TREATMENTS FOR CHRONIC NEUROPATHIC PAIN HIGHLIGHT THE NEED FOR SAFER AND MORE EFFECTIVE ALTERNATIVES. THE AUTHORS CARRIED OUT A FOCUSED REVIEW USING A SYSTEMS BIOLOGY APPROACH TO INTEGRATE THE COMPLEX MECHANISMS OF NOCICEPTION AND NEUROPATHIC PAIN, AND TO DECIPHER THE EFFECTS OF NITROUS OXIDE (N(2)O) ON THOSE PATHWAYS, BEYOND THE KNOWN EFFECT OF N(2)O ON N-METHYL-D-ASPARTATE RECEPTORS. THIS REVIEW IDENTIFIED A NUMBER OF POTENTIAL MECHANISMS BY WHICH N(2)O COULD IMPACT THE PROCESSES INVOLVED IN PERIPHERAL AND CENTRAL SENSITIZATION. IN THE ASCENDING PATHWAY, THE EFFECTS OF N(2)O INCLUDE ACTIVATING TWIK-RELATED K(+) CHANNEL 1 POTASSIUM CHANNELS ON FIRST-ORDER NEURONS, BLOCKING VOLTAGE-DEPENDENT CALCIUM CHANNELS TO ATTENUATE NEURONAL EXCITABILITY, ATTENUATING POSTSYNAPTIC GLUTAMATERGIC RECEPTOR ACTIVATION, AND POSSIBLY BLOCKING VOLTAGE-DEPENDENT SODIUM CHANNELS. IN THE DESCENDING PATHWAY, N(2)O INDUCES THE RELEASE OF ENDOGENOUS OPIOID LIGANDS AND STIMULATES NOREPINEPHRINE RELEASE. IN ADDITION, N(2)O MAY MEDIATE EPIGENETIC CHANGES BY INHIBITING METHIONINE SYNTHASE, A KEY ENZYME INVOLVED IN DNA AND RNA METHYLATION. THIS COULD EXPLAIN WHY THIS SHORT-ACTING ANALGESIC HAS SHOWN LONG-LASTING ANTI-PAIN SENSITIZATION EFFECTS IN ANIMAL MODELS OF CHRONIC PAIN. THESE NEW HYPOTHESES SUPPORT THE RATIONALE FOR INVESTIGATING N(2)O, EITHER ALONE OR IN COMBINATION WITH OTHER ANALGESICS, FOR THE MANAGEMENT OF CHRONIC NEUROPATHIC PAIN. 2021 20 2203 28 EPIGENETIC MODIFICATION OF SPINAL MIR-219 EXPRESSION REGULATES CHRONIC INFLAMMATION PAIN BY TARGETING CAMKIIGAMMA. EMERGING EVIDENCE HAS SHOWN THAT MIRNA-MEDIATED GENE EXPRESSION MODULATION CONTRIBUTES TO CHRONIC PAIN, BUT ITS FUNCTIONAL REGULATORY MECHANISM REMAINS UNKNOWN. HERE, WE FOUND THAT COMPLETE FREUND'S ADJUVANT (CFA)-INDUCED CHRONIC INFLAMMATION PAIN SIGNIFICANTLY REDUCED MIRNA-219 (MIR-219) EXPRESSION IN MICE SPINAL NEURONS. FURTHERMORE, THE EXPRESSION OF SPINAL CAMKIIGAMMA, AN EXPERIMENTALLY VALIDATED TARGET OF MIR-219, WAS INCREASED IN CFA MICE. OVEREXPRESSION OF SPINAL MIR-219 PREVENTED AND REVERSED THERMAL HYPERALGESIA AND MECHANICAL ALLODYNIA AND SPINAL NEURONAL SENSITIZATION INDUCED BY CFA. CONCURRENTLY, INCREASED EXPRESSION OF SPINAL CAMKIIGAMMA WAS REVERSED BY MIR-219 OVEREXPRESSION. DOWNREGULATION OF SPINAL MIR-219 IN NAIVE MICE INDUCED PAIN-RESPONSIVE BEHAVIORS AND INCREASED P-NMDAR1 EXPRESSION, WHICH COULD BE INHIBITED BY KNOCKDOWN OF CAMKIIGAMMA. BISULFITE SEQUENCING SHOWED THAT CFA INDUCED THE HYPERMETHYLATION OF CPG ISLANDS IN THE MIR-219 PROMOTER. TREATMENT WITH DEMETHYLATION AGENT 5'-AZA-2'-DEOXYCYTIDINE MARKEDLY ATTENUATED PAIN BEHAVIOR AND SPINAL NEURONAL SENSITIZATION, WHICH WAS ACCOMPANIED WITH THE INCREASE OF SPINAL MIR-219 AND DECREASE OF CAMKIIGAMMA EXPRESSION. TOGETHER, WE CONCLUDE THAT METHYLATION-MEDIATED EPIGENETIC MODIFICATION OF SPINAL MIR-219 EXPRESSION REGULATES CHRONIC INFLAMMATORY PAIN BY TARGETING CAMKIIGAMMA. 2014