1 2363 157 EPIGENETIC REGULATION OF SPINAL CORD GENE EXPRESSION CONTRIBUTES TO ENHANCED POSTOPERATIVE PAIN AND ANALGESIC TOLERANCE SUBSEQUENT TO CONTINUOUS OPIOID EXPOSURE. BACKGROUND: OPIOIDS HAVE BECOME THE MAINSTAY FOR TREATMENT OF MODERATE TO SEVERE PAIN AND ARE COMMONLY USED TO TREAT SURGICAL PAIN. WHILE OPIOID ADMINISTRATION HAS BEEN SHOWN TO CAUSE OPIOID-INDUCED HYPERALGESIA AND TOLERANCE, INTERACTIONS BETWEEN OPIOID ADMINISTRATION AND SURGERY WITH RESPECT TO THESE PROBLEMATIC ADAPTATIONS HAVE SCARCELY BEEN ADDRESSED. ACCUMULATING EVIDENCE SUGGESTS OPIOIDS AND NOCICEPTIVE SIGNALING MAY CONVERGE ON EPIGENETIC MECHANISMS IN SPINAL CORD TO ENHANCE OR PROLONG NEUROPLASTIC CHANGES. EPIGENETIC REGULATION OF BDNF (BRAIN-DERIVED NEUROTROPHIC FACTOR) AND PDYN (PRODYNORPHIN) GENES MAY BE INVOLVED. RESULTS: FOUR DAYS OF ASCENDING DOSES OF MORPHINE TREATMENT CAUSED OPIOID-INDUCED HYPERALGESIA AND REDUCED OPIOID ANALGESIC EFFICACY IN MICE. BOTH OPIOID-INDUCED HYPERALGESIA AND THE REDUCED OPIOID ANALGESIC EFFICACY WERE ENHANCED IN MICE THAT RECEIVED HINDPAW INCISIONS. THE EXPRESSION OF BDNF AND PDYN (QPCR) WAS INCREASED AFTER MORPHINE TREATMENT AND INCISION. CHROMATIN IMMUNOPRECIPITATION ASSAYS DEMONSTRATED THAT THE PDYN AND BDNF PROMOTERS WERE MORE STRONGLY ASSOCIATED WITH ACETYLATED H3K9 AFTER MORPHINE PLUS INCISION THAN IN THE MORPHINE OR INCISION ALONE GROUPS. SELECTIVE TROPOMYOSIN-RELATED KINASE B (ANA-12) AND KAPPA-OPIOID RECEPTOR (NOR-BINALTORPHIMINE) ANTAGONISTS WERE ADMINISTERED INTRATHECALLY, BOTH REDUCED HYPERALGESIA ONE OR THREE DAYS AFTER SURGERY. ADMINISTRATION OF ANA-12 OR NOR-BINALTORPHIMINE ATTENUATED THE DECREASED MORPHINE ANALGESIC EFFICACY ON DAY 1, BUT ONLY NOR-BINALTORPHIMINE WAS EFFECTIVE ON DAY 3 AFTER INCISION IN OPIOID-EXPOSED GROUP. COADMINISTRATION OF HISTONE ACETYLTRANSFERASE INHIBITOR ANACARDIC ACID DAILY WITH MORPHINE BLOCKED THE DEVELOPMENT OF OPIOID-INDUCED HYPERALGESIA AND ATTENUATED INCISION-ENHANCED HYPERALGESIA IN MORPHINE-TREATED MICE. ANACARDIC ACID HAD SIMILAR EFFECTS ON ANALGESIC TOLERANCE, SHOWING THE INVOLVEMENT OF HISTONE ACETYLATION IN THE INTERACTIONS DETECTED. CONCLUSIONS: SPINAL EPIGENETIC CHANGES INVOLVING BDNF AND PDYN MAY CONTRIBUTE TO THE ENHANCED POSTOPERATIVE NOCICEPTIVE SENSITIZATION AND ANALGESIC TOLERANCE OBSERVED AFTER CONTINUOUS OPIOID EXPOSURE. TREATMENTS BLOCKING THE EPIGENETICALLY MEDIATED UP-REGULATION OF THESE GENES OR ADMINISTRATION OF TRKB OR KAPPA-OPIOID RECEPTOR ANTAGONISTS MAY IMPROVE THE CLINICAL UTILITY OF OPIOIDS, PARTICULARLY AFTER SURGERY. 2016 2 5129 39 POSTOPERATIVE PAIN AND ANALGESIA: IS THERE A GENETIC BASIS TO THE OPIOID CRISIS? BACKGROUND: MULTIPLE FACTORS HAVE BEEN IMPLICATED IN DETERMINING WHY CERTAIN PATIENTS HAVE INCREASED POSTOPERATIVE PAIN, WITH THE POTENTIAL TO DEVELOP CHRONIC PAIN. THE PURPOSE OF THIS STUDY WAS TO: 1) IDENTIFY AND DESCRIBE GENES THAT AFFECT POSTOPERATIVE PAIN PERCEPTION AND CONTROL; 2) ADDRESS MODIFIABLE RISK FACTORS THAT RESULT IN EPIGENETIC ALTERED RESPONSES TO PAIN; AND 3) CHARACTERIZE DIFFERENCES IN PAIN SENSITIVITY AND THRESHOLDS BETWEEN OPIOID-NAIVE AND OPIOID-DEPENDENT PATIENTS. MATERIALS AND METHODS: THREE ELECTRONIC DATABASES WERE USED TO CONDUCT THE LITERATURE SEARCH: PUBMED, EBSCO HOST, AND SCOPUS. A TOTAL OF 372 ABSTRACTS WERE REVIEWED, OF WHICH 46 STUDIES WERE DEEMED RELEVANT AND ARE INCLUDED IN THIS REVIEW. RESULTS: SPECIFIC GENE ALTERATIONS THAT WERE SHOWN TO AFFECT POSTOPERATIVE PAIN CONTROL INCLUDED SINGLE NUCLEOTIDE POLYMORPHISMS IN THE MU, KAPPA, AND DELTA OPIOID RECEPTORS, ION CHANNEL GENES, CYTOTOXIC T-CELLS, GLUTAMATE RECEPTORS AND CYTOKINE GENES, AMONG OTHERS. ALCOHOLISM, OBESITY, AND SMOKING WERE ALL LINKED WITH GENETIC POLYMORPHISMS THAT ALTERED PAIN SENSITIVITY. OPIOID ABUSE WAS FOUND TO BE ASSOCIATED WITH A POORER RESPONSE TO ANALGESICS POSTOPERATIVELY, AS WELL AS A RISK FOR PRESCRIPTION OVERDOSE. CONCLUSION: ALTHOUGH PAIN PERCEPTION HAS MULTIPLE COMPLEX INFLUENCES, THE GREATEST VARIABILITY SEEN IN RESPONSE TO OPIOIDS AMONG POSTOPERATIVE PATIENTS KNOWN TO DATE CAN BE TRACED TO GENETIC DIFFERENCES IN OPIOID METABOLISM. FURTHER STUDY IS NEEDED TO DETERMINE THE CLINICAL SIGNIFICANCE OF THESE GENETIC ASSOCIATIONS. 2018 3 1559 42 DNA METHYLATION MODULATES NOCICEPTIVE SENSITIZATION AFTER INCISION. DNA METHYLATION IS A KEY EPIGENETIC MECHANISM CONTROLLING DNA ACCESSIBILITY AND GENE EXPRESSION. BLOCKADE OF DNA METHYLATION CAN SIGNIFICANTLY AFFECT PAIN BEHAVIORS IMPLICATED IN NEUROPATHIC AND INFLAMMATORY PAIN. HOWEVER, THE ROLE OF DNA METHYLATION WITH REGARD TO POSTOPERATIVE PAIN HAS NOT YET BEEN EXPLORED. IN THIS STUDY WE SOUGHT TO INVESTIGATE THE ROLE OF DNA METHYLATION IN MODULATING INCISIONAL PAIN AND IDENTIFY POSSIBLE TARGETS UNDER DNA METHYLATION AND CONTRIBUTING TO INCISIONAL PAIN. DNA METHYLTRANFERASE (DNMT) INHIBITOR 5-AZA-2'-DEOXYCYTIDINE SIGNIFICANTLY REDUCED INCISION-INDUCED MECHANICAL ALLODYNIA AND THERMAL SENSITIVITY. AZA-2'-DEOXYCYTIDINE ALSO REDUCED HINDPAW SWELLING AFTER INCISION, SUGGESTING AN ANTI-INFLAMMATORY EFFECT. GLOBAL DNA METHYLATION AND DNMT3B EXPRESSION WERE INCREASED IN SKIN AFTER INCISION, BUT NONE OF DNMT1, DNMT3A OR DNMT3B WAS ALTERED IN SPINAL CORD OR DRG. THE EXPRESSION OF PROOPIOMELANOCORTIN POMC ENCODING BETA-ENDORPHIN AND OPRM1 ENCODING THE MU-OPIOID RECEPTOR WERE UPREGULATED PERIPHERALLY AFTER INCISION; MOREOVER, OPRM1 EXPRESSION WAS FURTHER INCREASED UNDER DNMT INHIBITOR TREATMENT. FINALLY, LOCAL PERIPHERAL INJECTION OF THE OPIOID RECEPTOR ANTAGONIST NALOXONE SIGNIFICANTLY EXACERBATED INCISION-INDUCED MECHANICAL HYPERSENSITIVITY. THESE RESULTS SUGGEST THAT DNA METHYLATION IS FUNCTIONALLY RELEVANT TO INCISIONAL NOCICEPTIVE SENSITIZATION, AND THAT MU-OPIOID RECEPTOR SIGNALING MIGHT BE ONE METHYLATION REGULATED PATHWAY CONTROLLING SENSITIZATION AFTER INCISION. 2015 4 4851 44 OPIOIDS ENHANCE CXCL1 EXPRESSION AND FUNCTION AFTER INCISION IN MICE. CHRONIC OPIOID CONSUMPTION INCREASES POSTOPERATIVE PAIN. EPIGENETIC CHANGES RELATED TO CHRONIC OPIOID USE AND SURGICAL INCISION MAY BE PARTIALLY RESPONSIBLE FOR THIS ENHANCEMENT. THE CXCL1/CXCR2 SIGNALING PATHWAY, IMPLICATED IN SEVERAL PAIN MODELS, IS KNOWN TO BE EPIGENETICALLY REGULATED VIA HISTONE ACETYLATION. THE CURRENT STUDY WAS DESIGNED TO INVESTIGATE THE ROLE OF CXCL1/CXCR2 SIGNALING IN OPIOID-ENHANCED INCISIONAL SENSITIZATION AND TO ELUCIDATE THE POSSIBLE EPIGENETIC MECHANISM UNDERLYING CXCL1/CXCR2 PATHWAY-MEDIATED REGULATION OF NOCICEPTIVE SENSITIZATION IN MICE. CHRONIC MORPHINE TREATMENT GENERATED MECHANICAL AND THERMAL NOCICEPTIVE SENSITIZATION AND ALSO SIGNIFICANTLY EXACERBATED INCISION-INDUCED MECHANICAL ALLODYNIA. PERIPHERAL BUT NOT CENTRAL MESSENGER RNA LEVELS OF CXCL1 AND CXCR2 WERE INCREASED AFTER INCISION. THE SOURCE OF PERIPHERAL CXCL1 APPEARED TO BE WOUND AREA NEUTROPHILS. HISTONE H3 SUBUNIT ACETYLATED AT THE LYSINE 9 POSITION (ACH3K9) WAS INCREASED IN INFILTRATING DERMAL NEUTROPHILS AFTER INCISION AND WAS FURTHER INCREASED IN MICE WITH CHRONIC MORPHINE TREATMENT. THE ASSOCIATION OF ACH3K9 WITH THE PROMOTER REGION OF CXCL1 WAS ENHANCED IN MICE AFTER CHRONIC MORPHINE TREATMENT. THE INCREASE IN CXCL1 NEAR WOUNDS CAUSED BY CHRONIC MORPHINE PRETREATMENT WAS MIMICKED BY PHARMACOLOGIC INHIBITION OF HISTONE DEACETYLATION. FINALLY, LOCAL INJECTION OF CXCL1 INDUCED MECHANICAL SENSITIVITY IN NAIVE MICE, WHEREAS BLOCKING CXCR2 REVERSED MECHANICAL HYPERSENSITIVITY AFTER HIND PAW INCISION. PERSPECTIVE: PERIPHERAL CXCL1/CXCR2 SIGNALING HELPS TO CONTROL NOCICEPTIVE SENSITIZATION AFTER INCISION, AND EPIGENETIC REGULATION OF CXCL1 EXPRESSION EXPLAINS IN PART OPIOID-ENHANCED INCISIONAL ALLODYNIA IN MICE. THESE RESULTS SUGGEST THAT TARGETING CXCL1/CXCR2 SIGNALING MAY BE USEFUL IN TREATING NOCICEPTIVE SENSITIZATION, PARTICULARLY FOR POSTOPERATIVE PAIN IN CHRONIC OPIOID-CONSUMING PATIENTS. 2014 5 2365 53 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 6 3994 30 LONGITUDINAL PROFILING IN PATIENTS UNDERGOING CARDIAC SURGERY REVEALS POSTOPERATIVE CHANGES IN DNA METHYLATION. BACKGROUND: CARDIAC SURGERY AND CARDIOPULMONARY BYPASS INDUCE A SUBSTANTIAL IMMUNE AND INFLAMMATORY RESPONSE, THE OVERACTIVATION OF WHICH IS ASSOCIATED WITH SIGNIFICANT PULMONARY, CARDIOVASCULAR, AND NEUROLOGIC COMPLICATIONS. COMMENSURATE WITH THE IMMUNE AND INFLAMMATORY RESPONSE ARE CHANGES IN THE HEART AND VASCULATURE ITSELF, WHICH TOGETHER DRIVE POSTOPERATIVE COMPLICATIONS THROUGH MECHANISMS THAT ARE POORLY UNDERSTOOD. LONGITUDINAL DNA METHYLATION PROFILING HAS THE POTENTIAL TO IDENTIFY CHANGES IN GENE REGULATORY MECHANISMS THAT ARE SECONDARY TO SURGERY AND TO IDENTIFY MOLECULAR PROCESSES THAT PREDICT AND/OR CAUSE POSTOPERATIVE COMPLICATIONS. IN THIS STUDY, WE MEASURE DNA METHYLATION IN PREOPERATIVE AND POSTOPERATIVE WHOLE BLOOD SAMPLES FROM 96 PATIENTS UNDERGOING CARDIAC SURGERY ON CARDIOPULMONARY BYPASS. RESULTS: WHILE THE VAST MAJORITY OF DNA METHYLATION IS UNCHANGED BY SURGERY AFTER ACCOUNTING FOR CHANGES IN CELL-TYPE COMPOSITION, WE IDENTIFY SEVERAL LOCI WITH STATISTICALLY SIGNIFICANT POSTOPERATIVE CHANGES IN METHYLATION. ADDITIONALLY, TWO OF THESE LOCI ARE ASSOCIATED WITH NEW-ONSET POSTOPERATIVE ATRIAL FIBRILLATION, A SIGNIFICANT COMPLICATION AFTER CARDIAC SURGERY. PAIRED STATISTICAL ANALYSIS, USE OF FACS DATA TO SUPPORT SUFFICIENT CONTROL OF CELL-TYPE HETEROGENEITY, AND MEASUREMENT OF IL6 LEVELS IN A SUBSET OF PATIENTS ADD RIGOR TO THIS ANALYSIS, ALLOWING US TO DISTINGUISH CELL-TYPE VARIABILITY FROM ACTUAL CHANGES IN METHYLATION. CONCLUSIONS: THIS STUDY IDENTIFIES SIGNIFICANT CHANGES IN DNA METHYLATION THAT OCCUR IMMEDIATELY AFTER CARDIAC SURGERY AND DEMONSTRATES THAT THESE ACUTE ALTERATIONS IN DNA METHYLATION HAVE THE GRANULARITY TO IDENTIFY PROCESSES ASSOCIATED WITH MAJOR POSTOPERATIVE COMPLICATIONS. THIS RESEARCH ALSO ESTABLISHES METHODS FOR CONTROLLING FOR CELL-TYPE VARIABILITY IN A LARGE HUMAN COHORT THAT MAY BE USEFUL TO DEPLOY IN OTHER LONGITUDINAL STUDIES OF EPIGENETIC MARKS IN THE SETTING OF ACUTE AND CHRONIC DISEASE. 2022 7 4035 41 MACHINE-LEARNED ANALYSIS OF GLOBAL AND GLIAL/OPIOID INTERSECTION-RELATED DNA METHYLATION IN PATIENTS WITH PERSISTENT PAIN AFTER BREAST CANCER SURGERY. BACKGROUND: GLIAL CELLS IN THE CENTRAL NERVOUS SYSTEM PLAY A KEY ROLE IN NEUROINFLAMMATION AND SUBSEQUENT CENTRAL SENSITIZATION TO PAIN. THEY ARE THEREFORE INVOLVED IN THE DEVELOPMENT OF PERSISTENT PAIN. ONE OF THE MAIN SITES OF INTERACTION OF THE IMMUNE SYSTEM WITH PERSISTENT PAIN HAS BEEN IDENTIFIED AS NEURO-IMMUNE CROSSTALK AT THE GLIAL-OPIOID INTERFACE. THE PRESENT STUDY EXAMINED A POTENTIAL ASSOCIATION BETWEEN THE DNA METHYLATION OF TWO KEY PLAYERS OF GLIAL/OPIOID INTERSECTION AND PERSISTENT POSTOPERATIVE PAIN. METHODS: IN A COHORT OF 140 WOMEN WHO HAD UNDERGONE BREAST CANCER SURGERY, AND WERE ASSIGNED BASED ON A 3-YEAR FOLLOW-UP TO EITHER A PERSISTENT OR NON-PERSISTENT PAIN PHENOTYPE, THE ROLE OF EPIGENETIC REGULATION OF KEY PLAYERS IN THE GLIAL-OPIOID INTERFACE WAS ASSESSED. THE METHYLATION OF GENES CODING FOR THE TOLL-LIKE RECEPTOR 4 (TLR4) AS A MAJOR MEDIATOR OF GLIAL CONTRIBUTIONS TO PERSISTENT PAIN OR FOR THE MU-OPIOID RECEPTOR (OPRM1) WAS ANALYZED AND ITS ASSOCIATION WITH THE PAIN PHENOTYPE WAS COMPARED WITH THAT CONFERRED BY GLOBAL GENOME-WIDE DNA METHYLATION ASSESSED VIA QUANTIFICATION OF THE METHYLATION IN THE RETROTRANSPOSON LINE1. RESULTS: TRAINING OF MACHINE LEARNING ALGORITHMS INDICATED THAT THE GLOBAL DNA METHYLATION PROVIDED A SIMILAR DIAGNOSTIC ACCURACY FOR PERSISTENT PAIN AS PREVIOUSLY ESTABLISHED NON-GENETIC PREDICTORS. HOWEVER, THE DIAGNOSIS CAN BE BASED ON A SINGLE DNA BASED MARKER. BY CONTRAST, THE METHYLATION OF TLR4 OR OPRM1 GENES COULD NOT CONTRIBUTE FURTHER TO THE ALLOCATION OF THE PATIENTS TO THE PAIN-RELATED PHENOTYPE GROUPS. CONCLUSIONS: WHILE CLEARLY SUPPORTING A PREDICTIVE UTILITY OF EPIGENETIC TESTING, THE PRESENT ANALYSIS CANNOT PROVIDE SUPPORT FOR SPECIFIC EPIGENETIC MODULATION OF PERSISTENT POSTOPERATIVE PAIN VIA METHYLATION OF TWO KEY GENES OF THE GLIAL-OPIOID INTERFACE. 2019 8 4522 32 MULTIDIMENSIONAL EVALUATION OF THE PAIN PROFILE AS PROGNOSTIC FACTOR IN INDIVIDUALS WITH HIP OR KNEE OSTEOARTHRITIS RECEIVING TOTAL JOINT REPLACEMENT: PROTOCOL OF A 2-YEAR LONGITUDINAL PROGNOSTIC COHORT STUDY. INTRODUCTION: KNEE AND HIP OSTEOARTHRITIS ARE TWO HIGHLY PREVALENT MUSCULOSKELETAL PAIN CONDITIONS. UNSUCCESSFUL RATES AFTER HIP/KNEE REPLACEMENT RANGE FROM 10% TO 20%. SUBJECTS WITH SENSITISATION MANIFESTATIONS ARE VULNERABLE TO WORSE CLINICAL OUTCOMES. MOST STUDIES HAVE ANALYSED OUTCOMES UP TO 1 YEAR AFTER SURGERY. THE AIM OF THIS 2-YEAR LONGITUDINAL STUDY WILL BE TO EVALUATE SENSORY-RELATED, PSYCHOLOGICAL AND PSYCHOPHYSICAL PAIN SENSITISATION MANIFESTATIONS AND A POTENTIAL EPIGENETIC BIOMARKER AS PROGNOSTIC CLINICAL OUTCOMES FOR THE DEVELOPMENT OF CHRONIC POSTOPERATIVE PAIN AFTER KNEE OR HIP REPLACEMENT. METHODS AND ANALYSIS: A PROSPECTIVE LONGITUDINAL STUDY WITH A 2-YEAR FOLLOW-UP PERIOD WILL BE CONDUCTED. THE PROGNOSTIC VARIABLES WILL INCLUDE PAIN, FUNCTION, RELATED-DISABILITY, ANXIETY, DEPRESSION, QUALITY OF LIFE, SENSITISATION-ASSOCIATED SYMPTOMS, KINESIOPHOBIA, NEUROPATHIC PAIN AND CATASTROPHISING, AND EXPECTATIVE OF THE INTERVENTION WILL BE ASSESSED BEFORE SURGERY. WE WILL ALSO EVALUATE THE PRESENCE OF THE VAL158MET POLYMORPHISM AS A POSSIBLE EPIGENETIC MARKER. CLINICAL OUTCOMES INCLUDING PAIN, RELATED-DISABILITY AND SELF-PERCEIVED SATISFACTION, SENSITISATION-ASSOCIATED SYMPTOMS AND NEUROPATHIC PAIN WILL BE ASSESSED 3, 6, 12, 18 AND 24 MONTHS AFTER SURGERY. THESE VARIABLES WILL BE USED TO CONSTRUCT THREE PREDICTION MODELS: (1) PAIN AND FUNCTION, (2) SENSITISATION-ASSOCIATED SYMPTOMATOLOGY AND (3) NEUROPATHIC PAIN FEATURES CLASSIFYING THOSE PATIENTS IN RESPONDERS AND NON-RESPONDERS. DATA FROM KNEE OR HIP OSTEOARTHRITIS WILL BE ANALYSED SEPARATELY. STATISTICAL ANALYSES WILL BE CONDUCTED WITH LOGISTIC REGRESSIONS. ETHICS AND DISSEMINATION: THE STUDY HAS BEEN APPROVED BY THE ETHICS COMMITTEE OF BOTH INSTITUTIONS INVOLVED (HOSPITAL UNIVERSITARIO FUNDACION ALCORCON (HUFA) 19-141 AND UNIVERSIDAD REY JUAN CARLOS (URJC) 0312201917319). PARTICIPANTS WILL SIGN THE WRITTEN INFORMED CONSENT BEFORE THEIR INCLUSION. STUDY RESULTS WILL BE DISSEMINATED THROUGH PEER-REVIEWED PUBLICATIONS AND PRESENTATIONS AT SCIENTIFIC MEETINGS. 2023 9 5172 33 PREDICTING PAIN AFTER STANDARD PAIN THERAPY FOR KNEE OSTEOARTHRITIS - THE FIRST STEPS TOWARDS PERSONALIZED MECHANISTIC-BASED PAIN MEDICINE IN OSTEOARTHRITIS. OBJECTIVES: THE PREVALENCE OF OSTEOARTHRITIS (OA) IS RISING, AND PAIN IS THE HALLMARK SYMPTOM OF OA. PAIN IN OA IS COMPLICATED AND CAN BE INFLUENCED BY MULTIPLE JOINT-RELATED FACTORS AND FACTORS RELATED TO, E.G., PHYSIOLOGICAL, EPIGENETIC, AND PAIN SENSORY PROFILES. INCREASING EVIDENCE SUGGESTS THAT A SUBSET OF PATIENTS WITH OA ARE PAIN SENSITIVE. THIS CAN BE ASSESSED USING QUANTITATIVE SENSORY TESTING (QST). COMMON TREATMENTS OF OA ARE TOTAL KNEE ARTHROPLASTY (TKA) AND ADMINISTRATION OF 3-WEEKS OF NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), WHICH PROVIDE PAIN RELIEF TO MANY PATIENTS WITH OA. HOWEVER, APPROX. 20% OF PATIENTS EXPERIENCE CHRONIC POSTOPERATIVE PAIN AFTER TKA, WHEREAS NSAIDS PROVIDE AN AVERAGE PAIN RELIEF OF APPROX. 25%. THE CURRENT TOPICAL REVIEW FOCUSES ON THE EMERGING EVIDENCE LINKING PRETREATMENT QST TO THE TREATMENT RESPONSE OF TKA AND NSAID TREATMENTS. CONTENT: MEDLINE WAS SYSTEMATICALLY SEARCHED FOR ALL STUDIES FROM 2000 TO 2022 ON PRETREATMENT QST, TKA, AND NSAIDS. PRE-CLINICAL STUDIES, REVIEWS, AND META-ANALYSES WERE EXCLUDED. SUMMARY: CURRENTLY, 14 STUDIES ON TKA AND FOUR STUDIES ON NSAIDS HAVE BEEN PUBLISHED WITH THE AIM TO ATTEMPT PREDICTION OF THE TREATMENT RESPONSE. THE QST METHODOLOGIES IN THE STUDIES ARE INCONSISTENT, BUT 11/14 (79%) STUDIES ON TKA AND 4/4 (100%) STUDIES ON NSAIDS REPORT STATISTICALLY SIGNIFICANT ASSOCIATIONS BETWEEN PRETREATMENT QST AND CHRONIC POSTOPERATIVE PAIN AFTER TKA OR ANALGESIC EFFECT AFTER NSAID TREATMENT. THE STRENGTH OF THE ASSOCIATIONS REMAINS LOW-TO-MODERATE. THE MOST CONSISTENT PRETREATMENT QST PREDICTORS ARE PRESSURE PAIN THRESHOLDS, TEMPORAL SUMMATION OF PAIN, AND CONDITIONED PAIN MODULATION. OUTLOOK: THE USE OF QST AS PREDICTORS OF STANDARD OA TREATMENT IS INTERESTING, BUT THE PREDICTIVE STRENGTH REMAINS LOW-TO-MODERATE. A TRANSITION OF QST FROM A RESEARCH-BASED SETTING AND INTO THE CLINIC IS NOT ADVISED UNTIL THE PREDICTIVE STRENGTH HAS BEEN IMPROVED AND THE METHODOLOGY HAS BEEN STANDARDIZED. 2023 10 2364 76 EPIGENETIC REGULATION OF SPINAL CORD GENE EXPRESSION CONTROLS OPIOID-INDUCED HYPERALGESIA. BACKGROUND: THE LONG TERM USE OF OPIOIDS FOR THE TREATMENT OF PAIN LEADS TO A GROUP OF MALADAPTATIONS WHICH INCLUDES OPIOID-INDUCED HYPERALGESIA (OIH). OIH TYPICALLY RESOLVES WITHIN FEW DAYS AFTER CESSATION OF MORPHINE TREATMENT IN MICE BUT IS PROLONGED FOR WEEKS IF HISTONE DEACETYLASE (HDAC) ACTIVITY IS INHIBITED DURING OPIOID TREATMENT. THE PRESENT WORK SEEKS TO IDENTIFY GENE TARGETS SUPPORTING THE EPIGENETIC EFFECTS RESPONSIBLE FOR OIH PROLONGATION. RESULTS: MICE WERE TREATED WITH MORPHINE ACCORDING TO AN ASCENDING DOSE PROTOCOL. SOME MICE ALSO RECEIVED THE SELECTIVE HDAC INHIBITOR SUBEROYLANILIDE HYDROXAMIC ACID (SAHA) ADDITIONALLY. CHRONIC MORPHINE TREATMENT WITH SIMULTANEOUS HDAC INHIBITION ENHANCED OIH, AND SEVERAL SPINAL CORD GENES WERE UP-REGULATED. THE EXPRESSION OF BDNF (BRAIN-DERIVED NEUROTROPHIC FACTOR) AND PDYN (PRODYNORPHIN) WERE MOST CLOSELY RELATED TO THE OBSERVED BEHAVIORAL CHANGES. CHIP (CHROMATIN IMMUOPRECIPATION) ASSAYS DEMONSTRATED THAT PROMOTER REGIONS OF PDYN AND BDNF WERE STRONGLY ASSOCIATED WITH ACEH3K9 (ACETYLATED HISTONE H3 LYSINE9) AFTER MORPHINE AND SAHA TREATMENT. FURTHERMORE, MORPHINE TREATMENT CAUSED AN INCREASE IN SPINAL BDNF AND DYNORPHIN LEVELS, AND THESE LEVELS WERE FURTHER INCREASED IN SAHA TREATED MICE. THE SELECTIVE TRKB (TROPOMYOSIN-RECEPTOR-KINASE) ANTAGONIST ANA-12 REDUCED OIH WHEN GIVEN ONE OR SEVEN DAYS AFTER CESSATION OF MORPHINE. TREATMENT WITH THE SELECTIVE KAPPA OPIOID RECEPTOR ANTAGONIST NOR-BNI ALSO REDUCED ESTABLISHED OIH. THE CO-ADMINISTRATION OF EITHER RECEPTOR ANTAGONIST AGENT DAILY WITH MORPHINE RESULTED IN ATTENUATION OF HYPERALGESIA PRESENT ONE DAY AFTER CESSATION OF TREATMENT. ADDITIONALLY, REPEATED MORPHINE EXPOSURE INDUCED A RISE IN BDNF EXPRESSION THAT WAS ASSOCIATED WITH AN INCREASED NUMBER OF BDNF+ CELLS IN THE SPINAL CORD DORSAL HORN, SHOWING STRONG CO-LOCALIZATION WITH ACEH3K9 IN NEURONAL CELLS. LASTLY, SPINAL APPLICATION OF LOW DOSE BDNF OR DYNORPHIN A AFTER RESOLUTION OF OIH PRODUCED MECHANICAL HYPERSENSITIVITY, WITH NO EFFECT IN CONTROLS. CONCLUSIONS: THE PRESENT STUDY IDENTIFIED TWO GENES WHOSE EXPRESSION IS REGULATED BY EPIGENETIC MECHANISMS DURING MORPHINE EXPOSURE. TREATMENTS AIMED AT PREVENTING THE ACETYLATION OF HISTONES OR BLOCKING BDNF AND DYNORPHIN SIGNALING MAY REDUCE OIH AND IMPROVE LONG-TERM PAIN USING OPIOIDS. 2014 11 67 37 A LONGITUDINAL STUDY OF THE ASSOCIATIONS OF BDNF GENOTYPE AND METHYLATION WITH POSTSTROKE ANXIETY. BACKGROUND: ALTHOUGH THE PRECISE ETIOLOGY OF POSTSTROKE ANXIETY (PSA) HAS YET TO BE FULLY ELUCIDATED, IT IS KNOWN THAT BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IS IMPORTANT FOR NEURAL PLASTICITY AND LONG-TERM POTENTIATION, ASSOCIATED WITH THE PATHOPHYSIOLOGY OF ANXIETY. THE EXPRESSION OF BDNF IS REGULATED BY EPIGENETIC AND GENETIC PROFILES. THUS, WE INVESTIGATED THE ASSOCIATION BETWEEN BDNF METHYLATION STATUS AND PSA AT 2 WEEKS AND 1 YEAR AFTER STROKE WHILE ACCOUNTING FOR INTERACTIONS WITH THE BDNF VAL66MET POLYMORPHISM. METHODS: THE BASELINE SAMPLE COMPRISED 286 PATIENTS WHO WERE ASSESSED AT 2 WEEKS AFTER STROKE; OF THESE PATIENTS, 222 (78%) WERE FOLLOWED UP WITH AT 1 YEAR AFTER STROKE. THE PRESENCE OF PSA WAS DETERMINED USING THE ANXIETY SUBSCALE OF THE HOSPITAL ANXIETY AND DEPRESSION SCALE (HADS), AND THE EFFECTS OF BDNF METHYLATION STATUS AND POLYMORPHISMS ON PSA STATUS WERE ASSESSED WITH MULTIVARIATE LOGISTIC REGRESSION MODELS. RESULTS: THE PREVALENCE OF PSA WAS SLIGHTLY LOWER (27 [9.4%]) AT BASELINE, AND 35 (15.8%) PATIENTS WERE IDENTIFIED AS HAVING PSA AT THE 1-YEAR FOLLOW-UP. STROKE PATIENTS WITH A HIGHER AVERAGE METHYLATION STATUS WERE MORE LIKELY TO HAVE PSA AT 1 YEAR. THE BDNF VAL66MET POLYMORPHISM WAS NOT INDEPENDENTLY ASSOCIATED WITH PSA DURING EITHER THE ACUTE OR CHRONIC PHASE AFTER STROKE, BUT THERE WAS A SIGNIFICANT INTERACTIVE EFFECT BETWEEN BDNF METHYLATION AND GENOTYPE ON PSA AT 2 WEEKS. CONCLUSIONS: IN THIS STUDY, BDNF METHYLATION IN COMBINATION WITH THE MET/MET BDNF POLYMORPHISM (VAL66MET POLYMORPHISM) WAS ASSOCIATED WITH PSA. THESE FINDINGS MAY HELP IDENTIFY PATIENTS AT HIGHER RISK FOR PSA. 2019 12 2353 51 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 13 6612 38 ULTRA-LOW-DOSE NALOXONE ENHANCES THE ANTINOCICEPTIVE EFFECT OF MORPHINE IN PTX-TREATED RATS: REGULATION ON GLOBAL HISTONE METHYLATION. OBJECTIVE: EPIGENETIC REPROGRAMMING MAY HAVE A POSSIBLE ROLE IN NEUROPATHIC PAIN DEVELOPMENT; THE PRESENT STUDY EXAMINED THE GLOBAL PATTERNS OF LYSINE HISTONE MODIFICATION. IN THIS SERIAL STUDY WE ANALYZED THE LEVELS OF HISTONE 3 LYSINE 4 MONOMETHYLATION, HISTONE 3 LYSINE 4 DIMETHYLATION, AND HISTONE 3 LYSINE 9 TRIMETHYLATION IN PERTUSSIS TOXIN (PTX)-INDUCED THERMAL HYPERALGESIC RAT SPINAL CORDS. METHODS: MALE WISTAR RATS IMPLANTED WITH AN INTRATHECAL CATHETER RECEIVED A SINGLE INTRATHECAL PTX (1 MUG IN 5 MUL SALINE) INJECTION. FOUR DAYS LATER, THEY WERE RANDOMLY ASSIGNED TO RECEIVE EITHER A SINGLE INJECTION OF SALINE, OR ULTRA-LOW-DOSE NALOXONE (15 NG IN 5 MUL SALINE), FOLLOWED BY MORPHINE (10 MUG IN 5 MUL SALINE) INJECTION 30 MINUTES LATER. RESULTS: THE RESULTS SHOWED THAT PTX INJECTION INDUCED THERMAL HYPERALGESIA AND SIGNIFICANT INCREASE OF GLOBAL HISTONE METHYLATION IN THE SPINAL CORDS. INTRATHECAL MORPHINE ALONE DID NOT AFFECT THE THERMAL HYPERALGESIA AND GLOBAL HISTONE METHYLATION. IN CONTRAST, INTRATHECAL ADMINISTRATION OF ULTRA-LOW-DOSE NALOXONE PLUS MORPHINE SIGNIFICANTLY ATTENUATED THE PTX-INDUCED THERMAL HYPERALGESIA AND DOWN-REGULATED THE GLOBAL HISTONE METHYLATION. CONCLUSION: THE RESULTS SUGGEST THAT ULTRA-LOW-DOSE NALOXONE MIGHT BE CLINICAL VALUABLE FOR NEUROPATHIC PAIN MANAGEMENT VIA REGULATING GLOBAL HISTONE MODIFICATION. 2012 14 1238 34 CURCUMIN BLOCKS CHRONIC MORPHINE ANALGESIC TOLERANCE AND BRAIN-DERIVED NEUROTROPHIC FACTOR UPREGULATION. THIS STUDY WAS CARRIED OUT BASED ON THE ASSUMPTION THAT BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) MAY COUNTERBALANCE THE ACTION OF MORPHINE IN THE BRAIN. MORPHINE ANALGESIC TOLERANCE AFTER DAILY ADMINISTRATIONS FOR SIX DAYS WAS BLOCKED BY INTRACEREBROVENTRICULAR INJECTION OF ANTI-BDNF IGG ON DAY 5, BUT NOT BY ADMINISTRATIONS ON DAYS 1-4. CHRONIC MORPHINE TREATMENT SIGNIFICANTLY INCREASED THE EXPRESSION OF EXON I AND IV BDNF TRANSCRIPTS, INDICATING DIFFERENTIAL REGULATION OF BDNF GENE EXPRESSION. DAILY ADMINISTRATION OF THE CREB-BINDING PROTEIN INHIBITOR CURCUMIN ABOLISHED THE UPREGULATION OF BDNF TRANSCRIPTION AND MORPHINE ANALGESIC TOLERANCE. THESE RESULTS SUGGEST THAT CURCUMIN MIGHT BE A PROMISING ADJUVANT TO REDUCE MORPHINE ANALGESIC TOLERANCE, AND THAT EPIGENETIC CONTROL COULD BE A NEW STRATEGY USEFUL FOR THE CONTROL OF THIS PROBLEM. 2009 15 6039 54 THE CHEMOKINE RECEPTOR CXCR2 SUPPORTS NOCICEPTIVE SENSITIZATION AFTER TRAUMATIC BRAIN INJURY. CHRONIC PAIN AFTER TRAUMATIC BRAIN INJURY (TBI) IS VERY COMMON, BUT THE MECHANISMS LINKING TBI TO PAIN AND THE PAIN-RELATED INTERACTIONS OF TBI WITH PERIPHERAL INJURIES ARE POORLY UNDERSTOOD. CHEMOKINE RECEPTORS PLAY AN IMPORTANT ROLE IN BOTH PAIN AND BRAIN INJURY. IN THE CURRENT WORK, WE PURSUED THE HYPOTHESIS THAT THE EPIGENETICALLY REGULATED CXC CHEMOKINE RECEPTOR 2 (CXCR2) IS A CRUCIAL MODULATOR OF NOCICEPTIVE SENSITIZATION INDUCED BY TBI. FOR THESE STUDIES, WE USED THE RAT LATERAL FLUID PERCUSSION MODEL OF TBI. HISTONE ACTYLTRANSFERASE ACTIVITY WAS BLOCKED USING ANACARDIC ACID BEGINNING IMMEDIATELY FOLLOWING INJURY, OR DELAYED FOR SEVEN DAYS PRIOR TO ADMINISTRATION. THE SELECTIVE CXCR2 ANTAGONIST SCH527123 ADMINISTERED SYSTEMICALLY OR INTRATHECALLY WAS USED TO PROBE THE ROLE OF CHEMOKINE SIGNALING ON MECHANICAL HINDPAW SENSITIZATION AFTER TBI. THE EXPRESSION OF THE CXCR2 RECEPTOR WAS ACCOMPLISHED USING REAL-TIME PCR, IMMUNOHISTOCHEMISTRY, AND WESTERN BLOTTING, WHILE EPIGENETIC REGULATION WAS ASSESSED USING CHROMATIN IMMUNOPRECIPITATION ASSAY. THE SPINAL LEVELS OF SEVERAL PAIN-RELATED MEDIATORS INCLUDING CXCL1, AN ENDOGENOUS LIGAND FOR CXCR2, AS WELL AS BRAIN-DERIVED NEUROTROPHIC FACTOR AND PRODYNORPHIN WERE MEASURED BY ENZYME-LINKED IMMUNOSORBENT ASSAY. WE OBSERVED THAT ANACARDIC ACID POTENTLY BLOCKED AND REVERSED MECHANICAL HINDPAW SENSITIZATION AFTER TBI. THE SAME DRUG WAS ABLE TO PREVENT THE UPREGULATION OF CXCR2 AFTER TBI, BUT DID NOT AFFECT THE SPINAL EXPRESSION OF OTHER PAIN MEDIATORS. ON THE OTHER HAND, BOTH SYSTEMICALLY AND INTRATHECALLY ADMINISTERED SCH527123 REVERSED HINDPAW ALLODYNIA AFTER TBI. MOST OF THE SPINAL CXCR2 APPEARED TO BE EXPRESSED BY SPINAL CORD NEURONS. CHROMATIN IMMUNOPRECIPITATION EXPERIMENTS DEMONSTRATED TBI-ENHANCED ASSOCIATION OF THE CXCR2 PROMOTER WITH ACETYLATED-H3K9 HISTONE PROTEIN THAT WAS ALSO REVERSIBLE USING ANACARDIC ACID. TAKEN TOGETHER, OUR FINDINGS SUGGESTED THAT TBI CAUSES THE UPREGULATION OF SPINAL CXCR2 THROUGH AN EPIGENETIC MECHANISM ULTIMATELY SUPPORTING NOCICEPTIVE SENSITIZATION. THE USE OF CXCR2 ANTAGONISTS MAY, THEREFORE, BE USEFUL IN PAIN RESULTING FROM TBI. 2017 16 1833 34 EFFECTS OF METHYL DONOR DIETS ON INCISIONAL PAIN IN MICE. BACKGROUND: DIETARY SUPPLEMENTATION WITH METHYL DONORS CAN INFLUENCE THE PROGRAMMING OF EPIGENETIC PATTERNS RESULTING IN PERSISTENT ALTERATIONS IN DISEASE SUSCEPTIBILITY AND BEHAVIOR. HOWEVER, THE DIETARY EFFECTS OF METHYL DONORS ON PAIN HAVE NOT BEEN EXPLORED. IN THIS STUDY, WE EVALUATED THE EFFECTS OF DIETARY METHYL DONOR CONTENT ON PAIN RESPONSES IN MICE. METHODS: MALE AND FEMALE C57BL/6J MICE WERE TREATED WITH HIGH OR LOW METHYL DONOR DIETS EITHER IN THE PERINATAL PERIOD OR AFTER WEANING. MECHANICAL AND THERMAL NOCICEPTIVE SENSITIVITY WERE MEASURED BEFORE AND AFTER INCISION. RESULTS: MICE FED HIGH OR LOW METHYL DONOR DIETS DISPLAYED EQUAL WEIGHT GAIN OVER THE COURSE OF THE EXPERIMENTS. WHEN EXPOSED TO THESE DIETARY MANIPULATIONS IN THE PERINATAL PERIOD, ONLY MALE OFFSPRING OF DAMS FED A HIGH METHYL DONOR DIET DISPLAYED INCREASED MECHANICAL ALLODYNIA. HINDPAW INCISION IN THESE ANIMALS CAUSED ENHANCED NOCICEPTIVE SENSITIZATION, BUT DIETARY HISTORY DID NOT AFFECT THE DURATION OF SENSITIZATION. FOR MICE EXPOSED TO HIGH OR LOW METHYL DONOR DIETS AFTER WEANING, NO SIGNIFICANT DIFFERENCES WERE OBSERVED IN MECHANICAL OR THERMAL NOCICEPTIVE SENSITIVITY EITHER AT BASELINE OR IN RESPONSE TO HINDPAW INCISION. CONCLUSIONS: PERINATAL DIETARY FACTORS SUCH AS METHYL DONOR CONTENT MAY IMPACT PAIN EXPERIENCES IN LATER LIFE. THESE EFFECTS, HOWEVER, MAY BE SPECIFIC TO SEX AND PAIN MODALITY. 2013 17 524 31 ASSOCIATIONS OF BDNF GENOTYPE AND PROMOTER METHYLATION WITH ACUTE AND LONG-TERM STROKE OUTCOMES IN AN EAST ASIAN COHORT. BACKGROUND: BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) HAS BEEN SHOWN TO PLAY AN IMPORTANT ROLE IN POSTSTROKE RECOVERY. BDNF SECRETION IS INFLUENCED BY GENETIC AND EPIGENETIC PROFILES. THIS STUDY AIMED TO INVESTIGATE WHETHER BDNF VAL66MET POLYMORPHISM AND PROMOTER METHYLATION STATUS WERE ASSOCIATED WITH OUTCOMES AT TWO WEEKS AND ONE YEAR AFTER STROKE. METHODS AND FINDINGS: A TOTAL OF 286 PATIENTS WERE EVALUATED AT THE TIME OF ADMISSION AND TWO WEEKS AFTER STROKE, AND 222 (78%) WERE FOLLOWED ONE YEAR LATER IN ORDER TO EVALUATE CONSEQUENCES OF STROKE AT BOTH ACUTE AND CHRONIC STAGES. STROKE OUTCOMES WERE DICHOTOMISED INTO GOOD AND POOR BY THE MODIFIED RANKIN SCALE. STROKE SEVERITY (NATIONAL INSTITUTES OF HEALTH STROKE SCALE), PHYSICAL DISABILITY (BARTHEL INDEX), AND COGNITIVE FUNCTION (MINI-MENTAL STATE EXAMINATION) WERE MEASURED. ASSOCIATIONS OF BDNF GENOTYPE AND METHYLATION STATUS ON STROKE OUTCOMES AND ASSESSMENT SCALE SCORES WERE INVESTIGATED USING LOGISTIC REGRESSION, REPEATED MEASURES ANOVA AND PARTIAL CORRELATION TESTS. BDNF VAL66MET POLYMORPHISM WAS INDEPENDENTLY ASSOCIATED WITH POOR OUTCOME AT 2 WEEKS AND AT 1 YEAR, AND WITH WORSENING PHYSICAL DISABILITY AND COGNITIVE FUNCTION OVER THAT PERIOD. HIGHER BDNF PROMOTER METHYLATION STATUS WAS INDEPENDENTLY ASSOCIATED WITH WORSE OUTCOMES AT 1 YEAR, AND WITH THE WORSENING OF PHYSICAL DISABILITY AND COGNITIVE FUNCTION. NO SIGNIFICANT GENOTYPE-METHYLATION INTERACTIONS WERE FOUND. CONCLUSIONS: A ROLE FOR BDNF IN POSTSTROKE RECOVERY WAS SUPPORTED, AND CLINICAL UTILITY OF BDNF GENETIC AND EPIGENETIC PROFILE AS PROGNOSTIC BIOMARKERS AND A TARGET FOR DRUG DEVELOPMENT WAS SUGGESTED. 2012 18 5480 37 RESVERATROL REVERSES MORPHINE-INDUCED NEUROINFLAMMATION IN MORPHINE-TOLERANT RATS BY REVERSAL HDAC1 EXPRESSION. BACKGROUND/PURPOSE: WE PREVIOUSLY SHOWED THAT SUBSEQUENT INTRATHECAL (I.T.) INJECTION OF RESVERATROL (30 MUG) SIGNIFICANTLY REVERSES MORPHINE-EVOKED NEUROINFLAMMATION IN MORPHINE-TOLERANT RATS. THE PRESENT STUDY EXAMINED THE UNDERLYING MECHANISM. METHODS: MALE WISTAR RATS WERE IMPLANTED WITH TWO I.T. CATHETERS, ONE OF WHICH WAS CONNECTED TO A MINIOSMOTIC PUMP AND USED FOR MORPHINE (15 MUG/H) OR SALINE INFUSION FOR 120 HOURS. TO EXAMINE THE EFFECTS ON SPINAL CORD EXPRESSION OF HISTONE DEACETYLASE 1 (HDAC1), THE INFLAMMATORY CYTOKINE TUMOR NECROSIS FACTOR-ALPHA (TNF-ALPHA), AND TNF RECEPTOR (TNFR) 1 AND TNFR2 DURING TOLERANCE INDUCTION, A TAIL-FLICK TEST WAS PERFORMED PRIOR TO INFUSION AND AFTER 24 HOURS, 48 HOURS, 72 HOURS, 96 HOURS, AND 120 HOURS OF INFUSION. RESULTS: RESVERATROL TREATMENT PRIOR TO MORPHINE CHALLENGE RESTORED THE ANTINOCICEPTIVE EFFECT OF MORPHINE IN MORPHINE-TOLERANT RATS AND REVERSED THE MORPHINE INFUSION-INDUCED INCREASE IN HDAC1, TNF-ALPHA, AND TNFR1 EXPRESSION. MOREOVER, CHRONIC MORPHINE INFUSION INCREASED TNFR1-SPECIFIC EXPRESSION IN NEURON IN MORPHINE-TOLERANT RAT SPINAL CORDS, AND THIS EFFECT WAS ALMOST COMPLETELY INHIBITED BY RESVERATROL TREATMENT PRIOR TO MORPHINE CHALLENGE. CONCLUSION: RESVERATROL RESTORES THE ANTINOCICEPTIVE EFFECT OF MORPHINE BY REVERSING MORPHINE INFUSION-INDUCED SPINAL CORD NEUROINFLAMMATION AND INCREASE IN TNFR1 EXPRESSION. THE REVERSAL OF THE MORPHINE-INDUCED INCREASE IN TNFR1 EXPRESSION BY RESVERATROL IS PARTIALLY DUE TO REVERSAL OF THE MORPHINE INFUSION-INDUCED INCREASE IN HDAC1 EXPRESSION. RESVERATROL PRETREATMENT CAN BE USED AS AN ADJUVANT IN CLINICAL PAIN MANAGEMENT FOR PATIENTS WHO NEED LONG-TERM MORPHINE TREATMENT OR WITH NEUROPATHIC PAIN. 2016 19 4708 33 NO ASSOCIATION OF POLYMORPHISMS IN NAV1.7 OR NERVE GROWTH FACTOR RECEPTOR GENES WITH TRIGEMINAL NEURALGIA. OBJECTIVE: TRIGEMINAL NEURALGIA IS DEFINED AS A SUDDEN SEVERE SHOCK-LIKE PAIN WITHIN THE DISTRIBUTION OF THE TRIGEMINAL NERVE. PAIN IS A SUBJECTIVE EXPERIENCE THAT IS INFLUENCED BY GENDER, CULTURE, ENVIRONMENT, PSYCHOLOGICAL TRAITS, AND GENES. SODIUM CHANNELS AND NERVE GROWTH FACTOR PLAY IMPORTANT ROLES IN THE TRANSMISSION OF NOCICEPTIVE SIGNALS AND PAIN. THE AIM OF THIS STUDY WAS TO INVESTIGATE THE OCCURRENCE OF NAV1.7 SODIUM CHANNEL AND NERVE GROWTH FACTOR RECEPTOR TRKA GENE POLYMORPHISMS (SCN9A/RS6746030 AND NTRK1/RS633, RESPECTIVELY) IN TRIGEMINAL NEURALGIA PATIENTS. METHODS: NINETY-SIX SUBJECTS FROM PAIN SPECIALTY CENTERS IN THE SOUTHEASTERN REGION OF BRAZIL WERE DIVIDED INTO 2 GROUPS: 48 WITH CLASSICAL TRIGEMINAL NEURALGIA DIAGNOSIS AND 48 CONTROLS. PAIN WAS EVALUATED USING THE VISUAL ANALOG SCALE AND MULTIDIMENSIONAL MCGILL PAIN QUESTIONNAIRE. GENOMIC DNA WAS OBTAINED FROM ORAL SWABS IN ALL INDIVIDUALS AND WAS ANALYZED BY REAL-TIME POLYMERASE CHAIN REACTION. RESULTS: NO ASSOCIATION WAS OBSERVED BETWEEN EVALUATED POLYMORPHISMS AND TRIGEMINAL NEURALGIA. FOR ALLELE ANALYSES, PATIENTS AND CONTROLS HAD SIMILAR FREQUENCIES FOR BOTH GENES. GENOTYPE DISTRIBUTION OR ALLELE FREQUENCIES OF POLYMORPHISMS ANALYZED HERE DID NOT CORRELATE TO PAIN SCORES. CONCLUSIONS: ALTHOUGH NO ASSOCIATION OF EVALUATED POLYMORPHISMS AND TRIGEMINAL NEURALGIA DIAGNOSIS OR PAIN SEVERITY WAS OBSERVED, OUR DATA DO NOT EXCLUDE THE POSSIBILITY THAT OTHER GENOTYPES AFFECTING THE EXPRESSION OF NAV1.7 OR TRKA ARE ASSOCIATED WITH THE DISEASE. FURTHER STUDIES SHOULD INVESTIGATE DISTINCT GENETIC POLYMORPHISMS AND EPIGENETIC FACTORS THAT MAY BE IMPORTANT IN EXPRESSION OF THESE MOLECULES. 2019 20 5021 32 PERSISTENT PAIN MAINTAINS MORPHINE-SEEKING BEHAVIOR AFTER MORPHINE WITHDRAWAL THROUGH REDUCED MECP2 REPRESSION OF GLUA1 IN RAT CENTRAL AMYGDALA. AS LONG-TERM OPIOIDS ARE INCREASINGLY USED FOR CONTROL OF CHRONIC PAIN, HOW PAIN AFFECTS THE REWARDING EFFECT OF OPIOIDS AND HENCE RISK OF PRESCRIPTION OPIOID MISUSE AND ABUSE REMAINS A HEALTHCARE CONCERN AND A CHALLENGING ISSUE IN CURRENT PAIN MANAGEMENT. IN THIS STUDY, USING A RAT MODEL OF MORPHINE SELF-ADMINISTRATION, WE INVESTIGATED THE MOLECULAR MECHANISMS UNDERLYING THE IMPACT OF PAIN ON OPERANT BEHAVIOR OF MORPHINE INTAKE AND MORPHINE SEEKING BEFORE AND AFTER MORPHINE WITHDRAWAL. WE FOUND THAT RATS WITH PERSISTENT PAIN CONSUMED A SIMILAR AMOUNT OF DAILY MORPHINE TO THAT IN CONTROL RATS WITHOUT PAIN, BUT MAINTAINED THEIR LEVEL-PRESSING BEHAVIOR OF MORPHINE SEEKING AFTER ABSTINENCE OF MORPHINE AT 0.2 MG/KG, WHEREAS THIS BEHAVIOR WAS GRADUALLY DIMINISHED IN CONTROL RATS. IN THE CENTRAL NUCLEUS OF AMYGDALA (CEA), A LIMBIC STRUCTURE CRITICALLY INVOLVED IN THE AFFECTIVE DIMENSION OF PAIN, PROTEINS OF GLUA1 SUBUNITS OF GLUTAMATE AMPA RECEPTORS WERE UPREGULATED DURING MORPHINE WITHDRAWAL, AND VIRAL KNOCKDOWN OF CEA GLUA1 ELIMINATED THE MORPHINE-SEEKING BEHAVIOR IN WITHDRAWN RATS OF THE PAIN GROUP. CHROMATIN IMMUNOPRECIPITATION ANALYSIS REVEALED THAT THE METHYL CPG-BINDING PROTEIN 2 (MECP2) WAS ENRICHED IN THE PROMOTER REGION OF GRIA1 ENCODING GLUA1 AND THIS ENRICHMENT WAS SIGNIFICANTLY ATTENUATED IN WITHDRAWN RATS OF THE PAIN GROUP. FURTHERMORE, VIRAL OVEREXPRESSION OF CEA MECP2 REPRESSED THE GLUA1 LEVEL AND ELIMINATED THE MAINTENANCE OF MORPHINE-SEEKING BEHAVIOR AFTER MORPHINE WITHDRAWAL. THESE RESULTS SUGGEST DIRECT MECP2 REPRESSION OF GLUA1 FUNCTION AS A LIKELY MECHANISM FOR MORPHINE-SEEKING BEHAVIOR MAINTAINED BY LONG-LASTING AFFECTIVE PAIN AFTER MORPHINE WITHDRAWAL. 2015