1 1984 103 EPIGENETIC ALTERATIONS IN PRESCRIPTION OPIOID MISUSE: NEW STRATEGIES FOR PRECISION PAIN MANAGEMENT. PRESCRIPTION OPIOIDS ARE USED FOR SOME CHRONIC PAIN CONDITIONS. HOWEVER, GENERALLY, LONG-TERM THERAPY HAS UNWANTED SIDE EFFECTS WHICH MAY TRIGGER ADDICTION, OVERDOSE, AND EVENTUALLY CAUSE DEATHS. OPIOID ADDICTION AND CHRONIC PAIN CONDITIONS HAVE BOTH BEEN ASSOCIATED WITH EVIDENCE OF GENETIC AND EPIGENETIC ALTERATIONS. DESPITE INTENSE RESEARCH INTEREST, MANY QUESTIONS ABOUT THE CONTRIBUTION OF EPIGENETIC CHANGES TO THIS TYPOLOGY OF ADDICTION VULNERABILITY AND DEVELOPMENT REMAIN UNANSWERED. THE AIM OF THIS REVIEW WAS TO SUMMARIZE THE EPIGENETIC MODIFICATIONS DETECTED IN SPECIFIC TISSUES OR BRAIN AREAS AND ASSOCIATED WITH OPIOID PRESCRIPTION AND MISUSE IN PATIENTS WHO HAVE INITIATED PRESCRIBED OPIOID MANAGEMENT FOR CHRONIC NON-CANCER PAIN. THE REVIEW CONSIDERS THE EFFECTS OF OPIOID EXPOSURE ON THE EPIGENOME IN CENTRAL AND PERIPHERAL TISSUES IN ANIMAL MODELS AND HUMAN SUBJECTS AND HIGHLIGHTS THE MECHANISMS IN WHICH OPIOID EPIGENETICS MAY BE INVOLVED. THIS WILL IMPROVE OUR CURRENT UNDERSTANDING, PROVIDE THE BASIS FOR TARGETED, PERSONALIZED PAIN MANAGEMENT, AND THUS BALANCE OPIOID RISKS AND BENEFITS IN MANAGING CHRONIC PAIN. 2021 2 5038 22 PHARMACOGENETICS OF CHRONIC PAIN AND ITS TREATMENT. THIS PAPER REVIEWS THE IMPACT OF GENETIC VARIABILITY OF DRUG METABOLIZING ENZYMES, TRANSPORTERS, RECEPTORS, AND PATHWAYS INVOLVED IN CHRONIC PAIN PERCEPTION ON THE EFFICACY AND SAFETY OF ANALGESICS AND OTHER DRUGS USED FOR CHRONIC PAIN TREATMENT. SEVERAL CANDIDATE GENES HAVE BEEN IDENTIFIED IN THE LITERATURE, WHILE THERE IS USUALLY ONLY LIMITED CLINICAL EVIDENCE SUBSTANTIATING FOR THE PENETRATION OF THE TESTING FOR THESE CANDIDATE BIOMARKERS INTO THE CLINICAL PRACTICE. FURTHER, THE PAIN-PERCEPTION REGULATION AND MODULATION ARE STILL NOT FULLY UNDERSTOOD, AND THUS MORE COMPLEX KNOWLEDGE OF GENETIC AND EPIGENETIC BACKGROUND FOR ANALGESIA WILL BE NEEDED PRIOR TO THE CLINICAL USE OF THE CANDIDATE GENETIC BIOMARKERS. 2013 3 6391 28 THE ROLE OF THE GUT MICROBIOME AND MICROBIAL METABOLISM IN MEDIATING OPIOID-INDUCED CHANGES IN THE EPIGENOME. THE CURRENT OPIOID PANDEMIC IS A MAJOR PUBLIC HEALTH CRISIS IN THE UNITED STATES, AFFECTING MILLIONS OF PEOPLE AND IMPOSING SIGNIFICANT HEALTH AND SOCIOECONOMIC BURDENS. PRECLINICAL AND CLINICAL RESEARCH OVER THE PAST FEW DECADES HAS DELINEATED CERTAIN MOLECULAR MECHANISMS AND IDENTIFIED VARIOUS GENETIC, EPIGENETIC, AND ENVIRONMENTAL FACTORS RESPONSIBLE FOR THE PATHOPHYSIOLOGY AND COMORBIDITIES ASSOCIATED WITH OPIOID USE. OPIOID USE-INDUCED EPIGENETIC MODIFICATIONS HAVE BEEN IDENTIFIED AS ONE OF THE IMPORTANT FACTORS THAT MEDIATE GENETIC CHANGES IN BRAIN REGIONS THAT CONTROL REWARD AND DRUG-SEEKING BEHAVIOR AND ARE ALSO IMPLICATED IN THE DEVELOPMENT OF TOLERANCE. RECENTLY, IT HAS BEEN SHOWN THAT OPIOID USE RESULTS IN MICROBIAL DYSBIOSIS, LEADING TO GUT BARRIER DISRUPTION, WHICH DRIVES SYSTEMIC INFLAMMATION, IMPACTING THE PERCEPTION OF PAIN, THE DEVELOPMENT OF ANALGESIC TOLERANCE, AND BEHAVIORAL OUTCOMES. IN THIS REVIEW, WE HIGHLIGHT THE POTENTIAL ROLE OF MICROBIOTA AND MICROBIAL METABOLITES IN MEDIATING THE EPIGENETIC MODIFICATIONS INDUCED BY OPIOID USE. 2023 4 2611 30 EPIGENETICS: A PROMISING PARADIGM FOR BETTER UNDERSTANDING AND MANAGING PAIN. EPIGENETIC REGULATION OF GENE EXPRESSION IS A RAPIDLY GROWING AREA OF RESEARCH. CONSIDERING THE LONGEVITY AND PLASTICITY OF NEURONS, THE STUDIES ON EPIGENETIC PATHWAYS IN THE NERVOUS SYSTEM SHOULD BE OF SPECIAL INTEREST FOR BOTH EPIGENETICISTS AND NEUROSCIENTISTS. ACTIVATION OR INACTIVATION OF DIFFERENT EPIGENETIC PATHWAYS BECOMES MORE PRONOUNCED WHEN THE CELLS EXPERIENCE RAPID CHANGES IN THEIR ENVIRONMENT, AND SUCH CHANGES CAN BE EASILY CAUSED BY INJURY AND INFLAMMATION, RESULTING IN PAIN PERCEPTION OR DISTORTION OF PAIN PERCEPTION (EG, HYPERALGESIA). THEREFORE, IN THIS REGARD, THE FIELD OF PAIN IS AT AN ADVANTAGE TO STUDY THE EPIGENETIC PATHWAYS. MORE IMPORTANTLY, UNDERSTANDING PAIN FROM AN EPIGENETICS POINT OF VIEW WOULD PROVIDE A NEW PARADIGM FOR DEVELOPING DRUGS OR STRATEGIES FOR PAIN MANAGEMENT. IN THIS REVIEW, WE INTRODUCE BASIC CONCEPTS OF EPIGENETICS, INCLUDING CHROMATIN DYNAMICS, HISTONE MODIFICATIONS, DNA METHYLATION, AND RNA-INDUCED GENE SILENCING. IN ADDITION, WE PROVIDE EVIDENCE FROM PUBLISHED STUDIES SUGGESTING WIDE IMPLICATION OF DIFFERENT EPIGENETIC PATHWAYS WITHIN PAIN PATHWAYS. PERSPECTIVE: THIS ARTICLE PROVIDES A BRIEF OVERVIEW OF EPIGENETIC PATHWAYS FOR GENE REGULATION AND HIGHLIGHTS THEIR INVOLVEMENT IN PAIN. OUR GOAL IS TO EXPOSE THE READERS TO THESE CONCEPTS SO THAT PAIN-RELATED PHENOTYPES CAN BE INVESTIGATED FROM THE EPIGENETIC POINT OF VIEW. 2013 5 5926 37 TARGETING EPIGENETIC MECHANISMS FOR CHRONIC PAIN: A VALID APPROACH FOR THE DEVELOPMENT OF NOVEL THERAPEUTICS. CHRONIC PAIN IS A MULTIFACETED AND COMPLEX CONDITION. BROADLY CLASSIFIED INTO SOMATIC, VISCERAL, OR NEUROPATHIC PAIN, IT IS POORLY MANAGED DESPITE ITS PREVALENCE. CURRENT DRUGS USED FOR THE TREATMENT OF CHRONIC PAIN ARE LIMITED BY TOLERANCE WITH LONG-TERM USE, ABUSE POTENTIAL, AND MULTIPLE ADVERSE SIDE EFFECTS. THE PERSISTENT NATURE OF PAIN SUGGESTS THAT EPIGENETIC MACHINERY MAY BE A CRITICAL FACTOR DRIVING CHRONIC PAIN. IN THIS REVIEW, WE DISCUSS THE LATEST INSIGHTS INTO EPIGENETIC PROCESSES, INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS, AND MICRORNAS, AND WE DESCRIBE THEIR INVOLVEMENT IN THE PATHOPHYSIOLOGY OF CHRONIC PAIN AND WHETHER EPIGENETIC MODIFICATIONS COULD BE APPLIED AS FUTURE THERAPEUTIC TARGETS FOR CHRONIC PAIN. WE PROVIDE EVIDENCE FROM EXPERIMENTAL MODELS AND TRANSLATIONAL RESEARCH IN HUMAN TISSUE THAT HAVE ENHANCED OUR UNDERSTANDING OF EPIGENETIC PROCESSES MEDIATING NOCICEPTION, AND WE THEN SPECULATE ON THE POTENTIAL FUTURE USE OF MORE SPECIFIC AND SELECTIVE AGENTS THAT TARGET EPIGENETIC MECHANISMS TO ATTENUATE PAIN. 2016 6 1686 34 DRUGGING THE PAIN EPIGENOME. MORE THAN 20% OF ADULTS WORLDWIDE EXPERIENCE DIFFERENT TYPES OF CHRONIC PAIN, WHICH ARE FREQUENTLY ASSOCIATED WITH SEVERAL COMORBIDITIES AND A DECREASE IN QUALITY OF LIFE. SEVERAL APPROVED PAINKILLERS ARE AVAILABLE, BUT CURRENT ANALGESICS ARE OFTEN HAMPERED BY INSUFFICIENT EFFICACY AND/OR SEVERE ADVERSE EFFECTS. CONSEQUENTLY, NOVEL STRATEGIES FOR SAFE, HIGHLY EFFICACIOUS TREATMENTS ARE HIGHLY DESIRABLE, PARTICULARLY FOR CHRONIC PAIN. EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION, HISTONE MODIFICATIONS AND MICRORNAS (MIRNAS) STRONGLY AFFECT THE REGULATION OF GENE EXPRESSION, POTENTIALLY FOR LONG PERIODS OVER YEARS OR EVEN GENERATIONS, AND HAVE BEEN ASSOCIATED WITH PATHOPHYSIOLOGICAL PAIN. SEVERAL STUDIES, MOSTLY IN ANIMALS, REVEALED THAT INHIBITORS OF DNA METHYLATION, ACTIVATORS AND INHIBITORS OF HISTONE MODIFICATION AND MODULATORS OF MIRNAS REVERSE A NUMBER OF PATHOLOGICAL CHANGES IN THE PAIN EPIGENOME, WHICH ARE ASSOCIATED WITH ALTERED EXPRESSION OF PAIN-RELEVANT GENES. THIS EPIGENETIC MODULATION MIGHT THEN REDUCE THE NOCICEPTIVE RESPONSE AND PROVIDE NOVEL THERAPEUTIC OPTIONS FOR ANALGESIC THERAPY OF CHRONIC PAIN STATES. HOWEVER, A NUMBER OF CHALLENGES, SUCH AS NONSPECIFIC EFFECTS AND POOR DELIVERY TO TARGET CELLS AND TISSUES, HINDER THE RAPID DEVELOPMENT OF SUCH ANALGESICS. IN THIS REVIEW, WE CRITICALLY SUMMARIZE DATA ON EPIGENETICS AND PAIN, FOCUSING ON CHALLENGES IN CLINICAL DEVELOPMENT AS WELL AS POSSIBLE NEW APPROACHES TO THE DRUG MODULATION OF THE PAIN EPIGENOME. 2017 7 5928 24 TARGETING EPIGENETIC MECHANISMS FOR PAIN RELIEF. EPIGENETIC CHANGES ARE CHEMICAL MODIFICATIONS TO CHROMATIN THAT MODULATE GENE ACTIVITY WITHOUT ALTERING THE DNA SEQUENCE. WHILE RESEARCH ON EPIGENETICS HAS GROWN EXPONENTIALLY OVER THE PAST FEW YEARS, VERY FEW STUDIES HAVE INVESTIGATED EPIGENETIC MECHANISMS IN RELATION TO PAIN STATES. HOWEVER, EPIGENETIC MECHANISMS ARE CRUCIAL TO MEMORY FORMATION THAT REQUIRES SIMILAR SYNAPTIC PLASTICITY TO PAIN PROCESSING, INDICATING THAT THEY MAY PLAY A KEY ROLE IN THE CONTROL OF PAIN STATES. THIS ARTICLE REVIEWS THE EARLY EVIDENCE SUGGESTING THAT EPIGENETIC MECHANISMS ARE ENGAGED AFTER INJURY AND IN CHRONIC PAIN STATES, AND THAT DRUGS USED CLINICALLY TO TARGET THE EPIGENETIC MACHINERY FOR THE TREATMENT OF CANCER MIGHT BE USEFUL FOR THE MANAGEMENT OF CHRONIC PAIN. 2012 8 3472 29 IDENTIFICATION AND MANAGEMENT OF PAIN MEDICATION ABUSE AND MISUSE: CURRENT STATE AND FUTURE DIRECTIONS. LONG-TERM OPIOID THERAPY POSES A RISK FOR ABUSE AND MISUSE IN SOME PATIENTS. IDENTIFYING WHICH PATIENTS MAY POTENTIALLY BE AT RISK PRIOR TO INITIATION OF THERAPY, AND IDENTIFYING PATIENTS IN WHOM THESE PROBLEMS DEVELOP DURING THERAPY, ARE SIGNIFICANT CHALLENGES. OUTCOME PREDICTION IS IMPEDED BY THE COMPLEXITY OF THE PROBLEM, WHERE CONSIDERABLE HETEROGENEITY RESULTS FROM PSYCHOLOGICAL AND SOCIOECONOMIC FACTORS, AS WELL AS INTERINDIVIDUAL VARIATION IN BIOLOGICAL PATHWAYS DUE TO GENETIC AND EPIGENETIC FACTORS. SCREENING TOOLS DESIGNED TO DETECT OPIOID MISUSE AND URINE DRUG TESTING ARE BOTH USED CLINICALLY; SCANT EVIDENCE CURRENTLY EXISTS TO ALLOW THE FORMULATION OF AN ALGORITHM FOR JUDICIOUS USE OF THESE TOOLS. MOREOVER, THESE TOOLS MAY NOT BE ADDRESSING THE UNDERLYING ALTERATIONS IN BIOLOGICAL PATHWAYS THAT OCCUR OWING TO THE DEVELOPMENT OF CHRONIC PAIN OR IN RESPONSE TO CHRONIC OPIOID ADMINISTRATION. AN EVIDENCE-BASED ALGORITHMIC APPROACH TO RISK MITIGATION THAT CAN BE APPLIED IN A COST-EFFECTIVE MANNER TO GUIDE THERAPY IS URGENTLY NEEDED. 2012 9 1291 27 DECODING THE ROLE OF EPIGENETICS AND GENOMICS IN PAIN MANAGEMENT. PERSISTENT PAIN IS A COSTLY EPIDEMIC, AFFECTING >50 MILLION AMERICANS WITH ESTIMATED EXPENDITURES OF >$200 BILLION ANNUALLY FOR DIRECT CARE AND LOST PRODUCTIVITY. RECENT ADVANCES IN EPIGENETIC/GENOMIC UNDERSTANDING OF PAIN AND ANALGESIC RESPONSE MAY LEAD TO IMPROVEMENTS IN PAIN MANAGEMENT AND HELP CURTAIL COSTS BY PROVIDING MORE PRECISE DETECTION OF THE PAIN MECHANISMS INVOLVED AND THEREBY MORE PERSONALIZED AND EFFECTIVE TREATMENTS. HOWEVER, THE TRANSLATION OF EPIGENETIC AND GENOMIC STRATEGIES FOR PAIN MANAGEMENT INTO CLINICAL PRACTICE WILL DEPEND ON UNDERSTANDING THEIR POTENTIAL APPLICATIONS. THE PURPOSE OF THIS ARTICLE IS TO EXAMINE CURRENT KNOWLEDGE ABOUT EPIGENETIC AND GENOMIC MECHANISMS OF PERSISTENT PAIN AND POTENTIAL OPPORTUNITIES FOR IMPROVING PAIN MANAGEMENT. THE INITIAL DISCUSSION FOCUSES ON PRESENT UNDERSTANDING OF NOCICEPTIVE PATHWAYS AND ALTERATIONS THAT LEAD TO PATHOLOGIC PAIN. THE DISCUSSION THEN MOVES TO A REVIEW OF EPIGENETIC MECHANISMS THAT HAVE BEEN IDENTIFIED IN THE TRANSITION TO AND MAINTENANCE OF PERSISTENT PAIN AS WELL AS IN THE INDIVIDUAL'S RESPONSE TO ANALGESICS. POTENTIAL APPLICATIONS OF EPIGENETICS/GENOMICS TO IDENTIFY PEOPLE AT RISK AND POSSIBLY PREVENT PERSISTENT PAIN AND GUIDE DIAGNOSIS AND THE SELECTION OF THERAPEUTIC MODALITIES ARE PRESENTED. 2013 10 2586 27 EPIGENETICS OF PAIN MEDIATORS. PURPOSE OF REVIEW: THE FIELD OF EPIGENETICS CONTINUES ITS INFLUENTIAL RISE AS A MEANS TO BETTER UNDERSTAND AN ORGANISM'S UNIQUE DEVELOPMENTAL IDENTITY OVER A LIFESPAN. WHEREAS A GENOME IS CONSTANT AND UNCHANGING, AN EPIGENOME IS DYNAMIC AND ALTERABLE. EPIGENETIC CHANGES ARE IN RESPONSE TO INNUMERABLE INTERNAL AND EXTERNAL INFLUENCES INCLUDING ENVIRONMENTAL CHANGES SUCH AS DIET, EXERCISE, DISEASE, TOXINS, AND STRESS. EPIGENETICS IS OF PARTICULAR INTEREST IN THE MEDICAL RESEARCH COMMUNITY BOTH FOR THE POTENTIAL TO CAUSE DISEASE AND AS A TARGET FOR THERAPEUTIC INTERVENTIONS. THIS ARTICLE PROVIDES A SUCCINCT EXPLANATION OF THE POTENTIAL FOR EPIGENETICS TO INFLUENCE THE UNDERSTANDING OF PAIN AS WELL AS A REVIEW OF RELEVANT RESEARCH ON THE TOPIC. RECENT FINDINGS: STUDIES ON EPIGENETICS AND PAIN REMAIN LARGELY PRECLINICAL AND INVESTIGATE THE THEORETICAL ABILITY OF EPIGENETICS TO ALTER THE NOCICEPTIVE PATHWAYS BOTH IN THE PERIPHERY AND CENTRALLY. SIGNIFICANT EVIDENCE NOW EXISTS FOR THE ABILITY OF EPIGENETICS TO MODIFY BROADLY CATEGORIZED PAIN TYPES, INCLUDING INFLAMMATORY, NEUROPATHIC, VISCERAL, AND CANCER RELATED. SUMMARY: BOTH PATIENTS AND PROVIDERS RECOGNIZE THAT NOVEL MEDICATIONS FOR THE TREATMENT OF BOTH ACUTE AND CHRONIC PAIN CONDITIONS ARE SORELY NEEDED. THE UNDERSTANDING OF EPIGENETICS AND ITS INFLUENCE ON NOCICEPTION REMAINS IN RELATIVE INFANCY BUT EARLY EVIDENCE IS STRONG FOR POTENTIAL THERAPEUTIC BENEFITS TO TREAT THESE CONDITIONS. 2018 11 1796 35 EFFECT OF GERM-FREE STATUS ON TRANSCRIPTIONAL PROFILES IN THE NUCLEUS ACCUMBENS AND TRANSCRIPTOMIC RESPONSE TO CHRONIC MORPHINE. OPIOID USE DISORDER IS A PUBLIC HEALTH CRISIS THAT CAUSES TREMENDOUS SUFFERING FOR PATIENTS AS WELL AS SUBSTANTIAL SOCIAL AND ECONOMIC COSTS FOR SOCIETY. THERE ARE CURRENTLY AVAILABLE TREATMENTS FOR PATIENTS WITH OPIOID USE DISORDER, BUT THEY REMAIN INTOLERABLE OR INEFFECTIVE FOR MANY. THUS THE NEED TO DEVELOP NEW AVENUES FOR THERAPEUTICS DEVELOPMENT IN THIS SPACE IS GREAT. SUBSTANTIAL WORK IN MODELS OF SUBSTANCE USE DISORDERS, INCLUDING OPIOID USE DISORDER, DEMONSTRATES THAT PROLONGED EXPOSURE TO DRUGS OF ABUSE LEADS TO MARKED TRANSCRIPTIONAL AND EPIGENETIC DYSREGULATION IN LIMBIC SUBSTRUCTURES. IT IS WIDELY BELIEVED THAT THESE CHANGES IN GENE REGULATION IN RESPONSE TO DRUGS ARE A KEY DRIVING FACTOR IN THE PERPETUATION OF DRUG TAKING AND SEEKING BEHAVIORS. THUS, DEVELOPMENT OF INTERVENTIONS THAT COULD SHAPE TRANSCRIPTIONAL REGULATION IN RESPONSE TO DRUGS OF ABUSE WOULD BE OF HIGH VALUE. OVER THE PAST DECADE THERE HAS BEEN A SURGE IN RESEARCH DEMONSTRATING THAT THE RESIDENT BACTERIA OF THE GASTROINTESTINAL TRACT, COLLECTIVELY THE GUT MICROBIOME, CAN HAVE TREMENDOUS INFLUENCE ON NEUROBIOLOGICAL AND BEHAVIORAL PLASTICITY. PREVIOUS WORK FROM OUR GROUP AND OTHERS HAS DEMONSTRATED THAT ALTERATIONS IN THE GUT MICROBIOME CAN ALTER BEHAVIORAL RESPONSES TO OPIOIDS IN MULTIPLE PARADIGMS. ADDITIONALLY, WE HAVE PREVIOUSLY REPORTED THAT DEPLETION OF THE GUT MICROBIOME WITH ANTIBIOTICS MARKEDLY SHIFTS THE TRANSCRIPTOME OF THE NUCLEUS ACCUMBENS FOLLOWING PROLONGED MORPHINE EXPOSURE. IN THIS MANUSCRIPT WE PRESENT A COMPREHENSIVE ANALYSIS OF THE EFFECTS OF THE GUT MICROBIOME ON TRANSCRIPTIONAL REGULATION OF THE NUCLEUS ACCUMBENS FOLLOWING MORPHINE BY UTILIZING GERM-FREE, ANTIBIOTIC TREATED, AND CONTROL MICE. THIS ALLOWS FOR DETAILED UNDERSTANDING OF THE ROLE OF THE MICROBIOME IN REGULATING BASELINE TRANSCRIPTOMIC CONTROL, AS WELL AS RESPONSE TO MORPHINE. WE FIND THAT GERM-FREE STATUS LEADS TO A MARKED GENE DYSREGULATION IN A MANNER DISTINCT TO ADULT MICE TREATED WITH ANTIBIOTICS, AND THAT ALTERED GENE PATHWAYS ARE HIGHLY RELATED TO CELLULAR METABOLIC PROCESSES. THESE DATA PROVIDE ADDITIONAL INSIGHT INTO THE ROLE OF THE GUT MICROBIOME IN MODULATING BRAIN FUNCTION AND LAY A FOUNDATION FOR FURTHER STUDY IN THIS AREA. 2023 12 6755 36 WILL WIDESPREAD SYNTHETIC OPIOID CONSUMPTION INDUCE EPIGENETIC CONSEQUENCES IN FUTURE GENERATIONS? A GROWING NUMBER OF EVIDENCE DEMONSTRATES THAT ANCESTRAL EXPOSURE TO XENOBIOTICS (POLLUTANTS, DRUGS OF ABUSE, ETC.) CAN PERTURB THE PHYSIOLOGY AND BEHAVIOR OF DESCENDANTS. BOTH MATERNAL AND PATERNAL TRANSMISSION OF PHENOTYPE ACROSS GENERATIONS HAS BEEN PROVED, DEMONSTRATING THAT PARENTAL DRUG HISTORY MAY HAVE SIGNIFICANT IMPLICATIONS FOR SUBSEQUENT GENERATIONS. IN THE LAST YEARS, THE BURDEN OF NOVEL SYNTHETIC OPIOID (NSO) CONSUMPTION, DUE TO INCREASED MEDICAL PRESCRIPTION OF PAIN MEDICATIONS AND TO EASIER ACCESSIBILITY OF THESE SUBSTANCES ON ILLEGAL MARKET, IS RAISING NEW QUESTIONS FIRST IN TERM OF PUBLIC HEALTH, BUT ALSO ABOUT THE CONSEQUENCES OF THE PARENTAL USE OF THESE DRUGS ON FUTURE GENERATIONS. BESIDES BEING ASSOCIATED TO THE NEONATAL ABSTINENCE SYNDROME, IN UTERO EXPOSURE TO OPIOIDS HAS AN IMPACT ON NEURONAL DEVELOPMENT WITH LONG-TERM REPERCUSSIONS THAT ARE POTENTIALLY TRANSMITTED TO SUBSEQUENT GENERATIONS. IN ADDITION, RECENT REPORTS SUGGEST THAT OPIOID USE EVEN BEFORE CONCEPTION INFLUENCES THE REACTIVITY TO OPIOIDS OF THE PROGENY AND THE FOLLOWING GENERATIONS, LIKELY THROUGH EPIGENETIC MECHANISMS. THIS REVIEW DESCRIBES THE CURRENT KNOWLEDGE ABOUT THE TRANSGENERATIONAL EFFECTS OF OPIOID CONSUMPTION. WE SUMMARIZE THE PRECLINICAL AND CLINICAL FINDINGS SHOWING THE IMPLICATIONS FOR THE SUBSEQUENT GENERATIONS OF PARENTAL EXPOSURE TO OPIOIDS EARLIER IN LIFE. LIMITATIONS OF THE EXISTING DATA ON NSOS AND NEW PERSPECTIVES OF THE RESEARCH ARE ALSO DISCUSSED, AS WELL AS CLINICAL AND FORENSIC CONSEQUENCES. 2018 13 6807 21 [EPIGENETICS AND PAIN]. CHRONIC PAIN AFFECTS APPROXIMATELY 20 % OF ADULTS WORLDWIDE AND IS OFTEN ASSOCIATED WITH A DECREASE IN THE QUALITY OF LIFE AND VARIOUS COMORBIDITIES. CONVENTIONAL ANALGESIC THERAPIES ARE FREQUENTLY INSUFFICIENT AND SOMETIMES LEAD TO SEVERE SIDE EFFECTS. THEREFORE, GREAT EFFORTS ARE STILL BEING MADE TO ELUCIDATE THE SIGNALLING PATHWAYS IN PAIN AND TO DEVELOP NEW, SAFE AND EFFECTIVE THERAPIES. EPIGENETIC MECHANISMS WHICH INTERFERE WITH THE REGULATION OF GENE EXPRESSION ARE INVOLVED IN THE PATHOGENESIS OF SEVERAL DISEASES AND ARE GAINING INCREASING IMPETUS IN MEDICAL RESEARCH. AS THEY ARE ALSO INVOLVED IN PAIN PROCESSING, A MODULATION OF THESE MECHANISMS MIGHT REPRESENT A NOVEL OPTION FOR THE THERAPY OF PAIN PATIENTS. 2014 14 2573 22 EPIGENETICS OF DRUG ABUSE: PREDISPOSITION OR RESPONSE. DRUG ADDICTION CONTINUES TO BE A SERIOUS MEDICAL AND SOCIAL PROBLEM. VULNERABILITY TO DEVELOP AN ADDICTION TO DRUGS IS DEPENDENT ON GENETIC, ENVIRONMENTAL, SOCIAL AND BIOLOGICAL FACTORS. IN PARTICULAR, THE INTERACTIONS OF ENVIRONMENTAL AND GENETIC FACTORS INDICATE THE SIGNIFICANCE OF EPIGENETIC MECHANISMS, WHICH HAVE BEEN FOUND TO OCCUR IN RESPONSE TO ILLICIT DRUG USE OR AS UNDERLYING FACTORS IN CHRONIC SUBSTANCE ABUSE AND RELAPSE. EPIGENETICS IS DEFINED AS THE HERITABLE AND POSSIBLY REVERSIBLE MODIFICATIONS IN GENE EXPRESSION THAT DO NOT INVOLVE ALTERATIONS IN THE DNA SEQUENCE. THIS REVIEW DISCUSSES THE VARIOUS TYPES OF EPIGENETIC MODIFICATIONS AND THEIR RELEVANCE TO DRUG ADDICTION TO ELUCIDATE WHETHER EPIGENETICS IS A PREDISPOSING FACTOR, OR A RESPONSE TO, DEVELOPING AN ADDICTION TO DRUGS OF ABUSE. 2012 15 4631 30 NEUROGENETICS OF ACUTE AND CHRONIC OPIATE/OPIOID ABSTINENCE: TREATING SYMPTOMS AND THE CAUSE. THIS REVIEW BEGINS WITH A COMPREHENSIVE HISTORY OF OPIOID DEPENDENCE AND TREATMENT IN THE UNITED STATES. THE FOCUS IS AN EVIDENCE-BASED TREATMENT MODEL FOR OPIOID/OPIATE DEPENDENT INDIVIDUALS. THE ROLE OF REWARD GENETIC POLYMORPHISMS AND THE EPIGENETIC MODIFICATIONS THAT LEAD TO VULNERABILITY TO USE AND MISUSE OF OPIATES/OPIOID TO TREAT PAIN ARE REVIEWED. THE NEUROCHEMICAL MECHANISMS OF ACUTE OPIATE WITHDRAWAL AND OPIATE/OPIOID REWARD MECHANISMS ARE EXPLORED WITH A GOAL OF IDENTIFYING SPECIFIC TREATMENT TARGETS. ALTERATIONS IN FUNCTIONAL BRAIN CONNECTIVITY BASED ON NEUROBIOLOGICAL MECHANISMS IN HEROIN DEPENDENCE AND ABSTINENCE ARE ALSO REVIEWED. A NEW CLINICAL MODEL AN ALTERNATIVE TO MERELY BLOCKING ACUTE WITHDRAWAL SYMPTOMS AS IDENTIFIED IN THE DSM -5 IS PROPOSED. GENETIC DIAGNOSIS AT THE ONSET OF DETOXIFICATION, TO DETERMINE RISK STRATIFICATION, AND IDENTIFY POLYMORPHIC GENE TARGETS FOR PHARMACEUTICAL AND NUTRACEUTICAL INTERVENTIONS, FOLLOWED BY THE SIMULTANEOUS INITIATION OF MEDICATION ASSISTED THERAPY (MAT), TO ENABLE PSYCHOLOGICAL EXTINCTION, AND STEADY PRO-DOPAMINERGIC THERAPY WITH THE GOAL OF DEVELOPING "DOPAMINE HOMEOSTASIS" IS RECOMMENDED. THE OBJECTIVE OF THESE INTERVENTIONS IS TO PREVENT FUTURE RELAPSE BY TREATING ALL "REWARD DEFICIENCY SYNDROME" (RDS) BEHAVIORS AND EVENTUALLY MAKE AN ADDICTION-FREE LIFE POSSIBLE. 2017 16 1248 30 CURRENT EVIDENCE FOR BIOLOGICAL BIOMARKERS AND MECHANISMS UNDERLYING ACUTE TO CHRONIC PAIN TRANSITION ACROSS THE PEDIATRIC AGE SPECTRUM. CHRONIC PAIN IS HIGHLY PREVALENT IN THE PEDIATRIC POPULATION. MANY FACTORS ARE INVOLVED IN THE TRANSITION FROM ACUTE TO CHRONIC PAIN. CURRENTLY, THERE ARE CONCEPTUAL MODELS PROPOSED, BUT THEY LACK A MECHANISTICALLY SOUND INTEGRATED THEORY CONSIDERING THE STAGES OF CHILD DEVELOPMENT. OBJECTIVE BIOMARKERS ARE CRITICALLY NEEDED FOR THE DIAGNOSIS, RISK STRATIFICATION, AND PROGNOSIS OF THE PATHOLOGICAL STAGES OF PAIN CHRONIFICATION. IN THIS ARTICLE, WE SUMMARIZE THE CURRENT EVIDENCE ON MECHANISMS AND BIOMARKERS OF ACUTE TO CHRONIC PAIN TRANSITIONS IN INFANTS AND CHILDREN THROUGH THE DEVELOPMENTAL LENS. THE GOAL IS TO IDENTIFY GAPS AND OUTLINE FUTURE DIRECTIONS FOR BASIC AND CLINICAL RESEARCH TOWARD A DEVELOPMENTALLY INFORMED THEORY OF PAIN CHRONIFICATION IN THE PEDIATRIC POPULATION. AT THE OUTSET, THE IMPORTANCE OF OBJECTIVE BIOMARKERS FOR CHRONIFICATION OF PAIN IN CHILDREN IS OUTLINED, FOLLOWED BY A SUMMARY OF THE CURRENT EVIDENCE ON THE MECHANISMS OF ACUTE TO CHRONIC PAIN TRANSITION IN ADULTS, IN ORDER TO CONTRAST WITH THE DEVELOPMENTAL MECHANISMS OF PAIN CHRONIFICATION IN THE PEDIATRIC POPULATION. EVIDENCE IS PRESENTED TO SHOW THAT CHRONIC PAIN MAY HAVE ITS ORIGIN FROM INSULTS EARLY IN LIFE, WHICH PRIME THE CHILD FOR THE DEVELOPMENT OF CHRONIC PAIN IN LATER LIFE. FURTHERMORE, AVAILABLE GENETIC, EPIGENETIC, PSYCHOPHYSICAL, ELECTROPHYSIOLOGICAL, NEUROIMAGING, NEUROIMMUNE, AND SEX MECHANISMS ARE DESCRIBED IN INFANTS AND OLDER CHILDREN. IN CONCLUSION, FUTURE DIRECTIONS ARE DISCUSSED WITH A FOCUS ON RESEARCH GAPS, TRANSLATIONAL AND CLINICAL IMPLICATIONS. UTILIZATION OF DEVELOPMENTAL MECHANISMS FRAMEWORK TO INFORM CLINICAL DECISION-MAKING AND STRATEGIES FOR PREVENTION AND MANAGEMENT OF ACUTE TO CHRONIC PAIN TRANSITIONS IN CHILDREN, IS HIGHLIGHTED. 2023 17 1204 35 COULD TARGETING EPIGENETIC PROCESSES RELIEVE CHRONIC PAIN STATES? PURPOSE OF REVIEW: ABERRATIONS IN THE EPIGENETIC LANDSCAPE HAVE PREVIOUSLY BEEN ASSOCIATED WITH HUMAN DISEASES SUCH AS CANCER AND SCHIZOPHRENIA, AND DRUGS THAT TARGET EPIGENETIC PROCESSES ARE CURRENTLY USED AS THERAPEUTIC AGENTS. THIS ARTICLE WILL REVIEW THE EVIDENCE OBTAINED FROM ANIMAL STUDIES INDICATING THAT EPIGENETIC PROCESSES MIGHT REGULATE LONG-TERM PAIN STATES AND THEN DISCUSS THE POSSIBILITY THAT TARGETING EPIGENETIC MECHANISMS MIGHT BE USEFUL FOR THE MANAGEMENT OF CHRONIC PAIN. RECENT FINDINGS: RECENT ANIMAL STUDIES HAVE REPORTED INJURY-INDUCED CHANGES IN EPIGENETIC PROCESSES IN THE CENTRAL NERVOUS SYSTEM. THE PICTURE THAT HAS EMERGED IS THAT OF VERY COMPLEX EPIGENETIC PROGRAMS THAT DEPEND ON THE INJURY. HOWEVER, SOME STUDIES HAVE REPORTED THE SUCCESSFUL USE OF NONSPECIFIC EPIGENETIC TOOLS TO IMPROVE THE HYPERSENSITIVITY THAT DEVELOPS IN ANIMAL MODELS OF LONG-TERM PAIN STATES. SUMMARY: THE FIELD OF EPIGENETICS AND PAIN IS RAPIDLY EMERGING BUT FURTHER INVESTIGATION IS NEEDED TO FULLY COMPREHEND THE CONTRIBUTION OF EPIGENETIC PROCESSES TO CHRONIC PAIN STATES. ALTHOUGH THERAPEUTIC APPROACHES TARGETING THESE MECHANISMS MIGHT SEEM WORTHWHILE, WE CANNOT ASSERT THAT CURRENTLY AVAILABLE GLOBAL TOOLS SUCH AS HISTONE DEACETYLASE INHIBITORS CAN BE USED SUCCESSFULLY FOR THE LONG-TERM TREATMENT OF CHRONIC PAIN STATES. 2015 18 4914 32 PAIN VULNERABILITY: A NEUROBIOLOGICAL PERSPECTIVE. THERE ARE MANY KNOWN RISK FACTORS FOR CHRONIC PAIN CONDITIONS, YET THE BIOLOGICAL UNDERPINNINGS THAT LINK THESE FACTORS TO ABNORMAL PROCESSING OF PAINFUL SIGNALS ARE ONLY JUST BEGINNING TO BE EXPLORED. THIS REVIEW WILL DISCUSS THE POTENTIAL MECHANISMS THAT HAVE BEEN PROPOSED TO UNDERLIE VULNERABILITY AND RESILIENCE TOWARD DEVELOPING CHRONIC PAIN. PARTICULAR FOCUS WILL BE GIVEN TO GENETIC AND EPIGENETIC PROCESSES, PRIMING EFFECTS ON A CELLULAR LEVEL, AND ALTERATIONS IN BRAIN NETWORKS CONCERNED WITH REWARD, MOTIVATION/LEARNING AND DESCENDING MODULATORY CONTROL. ALTHOUGH RESEARCH IN THIS AREA IS STILL IN ITS INFANCY, A BETTER UNDERSTANDING OF HOW PAIN VULNERABILITY EMERGES HAS THE POTENTIAL TO HELP IDENTIFY INDIVIDUALS AT RISK AND MAY OPEN UP NEW THERAPEUTIC AVENUES. 2014 19 6124 27 THE EPIGENETIC MECHANISMS INVOLVED IN CHRONIC PAIN IN RODENTS: A MINI- REVIEW. CHRONIC PAIN IS A COMMON DISTRESSING NEUROLOGICAL DISORDER AND ABOUT 30% OF THE GLOBAL POPULATION SUFFERS FROM IT. IN ADDITION TO BEING HIGHLY PREVALENT, CHRONIC PAIN CAUSES A HEAVY ECONOMIC AND SOCIAL BURDEN. ALTHOUGH SUBSTANTIAL PROGRESS HAS BEEN ACHIEVED TO DISSECT THE UNDERLYING MECHANISM OF CHRONIC PAIN IN THE PAST FEW DECADES, THE INCIDENCE AND TREATMENT OF THIS NEUROLOGICAL ILLNESS IS YET NOT PROPERLY MANAGED IN CLINICAL PRACTICE. WHILE NERVE INJURY-, CHEMOTHERAPY- OR INFLAMMATION-INDUCED FUNCTIONAL REGULATION OF GENE EXPRESSION IN THE DORSAL ROOT GANGLION AND SPINAL CORD ARE EXTENSIVELY REPORTED TO BE INVOLVED IN THE PATHOGENIC PROCESS OF CHRONIC PAIN, THE SPECIFIC MECHANISM OF THESE ALTERED TRANSCRIPTIONAL PROFILE STILL REMAINS UNCLEAR. RECENT STUDIES HAVE SHOWN THAT EPIGENETIC MECHANISMS, INCLUDING DNA/RNA METHYLATION, HISTONE MODIFICATION AND CIRCULAR RNAS REGULATION, ARE INVOLVED IN THE OCCURRENCE AND DEVELOPMENT OF CHRONIC PAIN. IN THIS REVIEW, WE PROVIDE A DESCRIPTION OF RESEARCH ON THE ROLE OF EPIGENETIC MECHANISM IN CHRONIC PAIN, SUMMARIZE THE LATEST CLINICAL AND PRECLINICAL ADVANCE IN THIS FIELD, AND PROPOSE THE POTENTIAL DIRECTIONS FOR FURTHER RESEARCH TO ELUCIDATE THE MOLECULAR MECHANISM UNDERLYING THE PATHOGENESIS OF CHRONIC PAIN. 2022 20 2963 23 GENETIC AND EPIGENETIC MECHANISMS LINKING PAIN AND PSYCHIATRIC DISORDERS. THE NEUROPHYSIOLOGICAL LINK BETWEEN NEUROPATHIC PAIN AND DEPRESSION REMAINS UNKNOWN DESPITE EVIDENT HIGH COMORBIDITY OF THESE TWO DISORDERS. HOWEVER, THERE IS CONVINCING EVIDENCE THAT GENOTYPE PLAYS A ROLE IN BOTH PAIN AND DEPRESSION. USING VARIOUS TYPES OF GENETIC ANALYSIS - POPULATION GENETICS, CYTOGENETICS AND MOLECULAR TECHNOLOGIES - SPECIFIC GENES HAVE BEEN IMPLICATED IN MEDIATING ALMOST ALL ASPECTS OF NOCICEPTION AND MOOD DISORDERS. THE CURRENT REVIEW ATTEMPTS TO IDENTIFY SPECIFIC GENES AND EPIGENETIC MECHANISMS COMMON TO BOTH DISORDERS. IT IS CONCLUDED THAT EXTERNAL AND INTERNAL FACTORS (INFLAMMATION, STRESS, GENDER, ETC.) THAT CONTRIBUTE TO THE PATHOLOGIES MAY DO SO THROUGH EPIGENETIC MECHANISMS THAT MAY AFFECT EXPRESSION OF THESE PARTICULAR GENES. THE POSSIBLE INVOLVEMENT OF EPIGENETIC REGULATION IN PAIN AND PSYCHIATRIC DISORDERS SUGGESTS THAT TREATMENTS TARGETING EPIGENETIC MECHANISMS THAT MEDIATE ADVERSE LIFE EVENTS SHOULD BE CONSIDERED. 2015