1 1688 133 DUAL BET/HDAC INHIBITION TO RELIEVE NEUROPATHIC PAIN: RECENT ADVANCES, PERSPECTIVES, AND FUTURE OPPORTUNITIES. DESPITE THE INTENSE RESEARCH ON DEVELOPING NEW THERAPIES FOR NEUROPATHIC PAIN STATES, AVAILABLE TREATMENTS HAVE LIMITED EFFICACY AND UNFAVORABLE SAFETY PROFILES. EPIGENETIC ALTERATIONS HAVE A GREAT INFLUENCE ON THE DEVELOPMENT OF CANCER AND NEUROLOGICAL DISEASES, AS WELL AS NEUROPATHIC PAIN. HISTONE ACETYLATION HAS PREVAILED AS ONE OF THE WELL INVESTIGATED EPIGENETIC MODIFICATIONS IN THESE DISEASES. ALTERED SPINAL ACTIVITY OF HISTONE DEACETYLASE (HDAC) AND BROMO AND EXTRA TERMINAL DOMAIN (BET) HAVE BEEN DESCRIBED IN NEUROPATHIC PAIN MODELS AND RESTORATION OF THESE ABERRANT EPIGENETIC MODIFICATIONS SHOWED PAIN-RELIEVING ACTIVITY. OVER THE LAST DECADES HDACS AND BETS HAVE BEEN THE FOCUS OF DRUG DISCOVERY STUDIES, LEADING TO THE DEVELOPMENT OF NUMEROUS SMALL-MOLECULE INHIBITORS. CLINICAL TRIALS TO EVALUATE THEIR ANTICANCER ACTIVITY SHOWED GOOD EFFICACY BUT RAISED TOXICITY CONCERNS THAT LIMITED TRANSLATION TO THE CLINIC. TO MAXIMIZE ACTIVITY AND MINIMIZE TOXICITY, THESE COMPOUNDS CAN BE APPLIED IN COMBINATION OF SUB-MAXIMAL DOSES TO PRODUCE ADDITIVE OR SYNERGISTIC INTERACTIONS (COMBINATION THERAPY). RECENTLY, OF PARTICULAR INTEREST, DUAL BET/HDAC INHIBITORS (MULTI-TARGET DRUGS) HAVE BEEN DEVELOPED TO ASSURE SIMULTANEOUS MODULATION OF BET AND HDAC ACTIVITY BY A SINGLE MOLECULE. THIS REVIEW WILL SUMMARIZE THE MOST RECENT ADVANCES WITH THESE STRATEGIES, DESCRIBING ADVANTAGES AND LIMITATIONS OF SINGLE DRUG TREATMENT VS COMBINATION REGIMENS. THIS REVIEW WILL ALSO PROVIDE A FOCUS ON DUAL BET/HDAC DRUG DISCOVERY INVESTIGATIONS AS FUTURE THERAPEUTIC OPPORTUNITY FOR HUMAN THERAPY OF NEUROPATHIC PAIN. 2021 2 789 36 CELLULAR AND MOLECULAR MECHANISMS DRIVING NEUROPATHIC PAIN: RECENT ADVANCEMENTS AND CHALLENGES. CURRENT PHARMACOTHERAPEUTICS FOR NEUROPATHIC PAIN OFFER ONLY SYMPTOMATIC RELIEF WITHOUT TREATING THE UNDERLYING PATHOPHYSIOLOGY. ADDITIONALLY, THEY ARE ASSOCIATED WITH VARIOUS DOSE-LIMITING SIDE EFFECTS. PAIN RESEARCH IN THE PAST FEW DECADES HAS REVOLVED AROUND THE ROLE OF OXIDATIVE-NITROSATIVE STRESS, PROTEIN KINASES, GLIAL CELL ACTIVATION, AND INFLAMMATORY SIGNALING CASCADES BUT HAS FAILED TO PRODUCE SPECIFIC AND EFFECTIVE THERAPIES. AREAS COVERED: THIS REVIEW FOCUSES ON RECENT ADVANCES IN CELLULAR AND MOLECULAR MECHANISMS OF NEUROPATHIC PAIN THAT MAY BE TRANSLATED INTO FUTURE THERAPIES. WE DISCUSS EMERGING TARGETS SUCH AS WNT SIGNALING MECHANISMS, THE TETRAHYDROBIOPTERIN PATHWAY, MRG RECEPTORS, ENDOGENOUS LIPID MEDIATORS, MICRO-RNAS AND THEIR ROLES IN PAIN REGULATION. RECENT EVIDENCE IS ALSO PRESENTED REGARDING GENETIC AND EPIGENETIC MECHANISMS OF PAIN MODULATION. EXPERT OPINION: DURING CHRONIC NEUROPATHIC PAIN, MALADAPTATION OCCURS IN THE PERIPHERAL AND CENTRAL NERVOUS SYSTEMS, INCLUDING A SHIFT IN MICROGLIAL PHENOTYPE FROM A SURVEILLANCE STATE TO AN ACTIVATED STATE. MICROGLIAL ACTIVATION LEADS TO AN ALTERED EXPRESSION OF CELL SURFACE PROTEINS, GROWTH FACTORS, AND INTRACELLULAR SIGNALING MOLECULES THAT CONTRIBUTE TO DEVELOPMENT OF A NEUROINFLAMMATORY CASCADE AND CHRONIC PAIN SENSITIZATION. SPECIFIC TARGETING OF THESE CELLULAR AND MOLECULAR MECHANISMS MAY PROVIDE THE KEY TO DEVELOPMENT OF EFFECTIVE NEUROPATHIC PAIN THERAPIES THAT HAVE MINIMAL SIDE EFFECTS. 2018 3 2254 35 EPIGENETIC MODULATION: RESEARCH PROGRESS ON HISTONE ACETYLATION LEVELS IN MAJOR DEPRESSIVE DISORDERS. DEPRESSION IS A SERIOUS MENTAL ILLNESS AND A PREVALENT CONDITION WITH MULTIPLE AETIOLOGIES. THE IMPACT OF THE CURRENT THERAPEUTIC STRATEGIES IS LIMITED AND THE PATHOGENESIS OF THE ILLNESS IS NOT WELL UNDERSTOOD. ACCORDING TO PREVIOUS STUDIES, DEPRESSION ONSET IS INFLUENCED BY A VARIETY OF ENVIRONMENTAL AND GENETIC FACTORS, INCLUDING CHRONIC STRESS, ABERRANT CHANGES IN GENE EXPRESSION, AND HEREDITARY PREDISPOSITION. TRANSCRIPTIONAL REGULATION IN EUKARYOTES IS CLOSELY RELATED TO CHROMOSOME PACKING AND IS CONTROLLED BY HISTONE POST-TRANSLATIONAL MODIFICATIONS. THE DEVELOPMENT OF NEW ANTIDEPRESSANTS MAY PROCEED ALONG A NEW PATH WITH MEDICATIONS THAT TARGET EPIGENETICS. HISTONE DEACETYLASE INHIBITORS (HDACIS) ARE A CLASS OF COMPOUNDS THAT INTERFERE WITH THE FUNCTION OF HISTONE DEACETYLASES (HDACS). THIS REVIEW EXPLORES THE RELATIONSHIP BETWEEN HDACS AND DEPRESSION AND FOCUSES ON THE CURRENT KNOWLEDGE ON THEIR REGULATORY MECHANISM IN DEPRESSION AND THE POTENTIAL THERAPEUTIC USE OF HDACIS WITH ANTIDEPRESSANT EFFICACY IN PRECLINICAL RESEARCH. FUTURE RESEARCH ON INHIBITORS IS ALSO PROPOSED AND DISCUSSED. 2023 4 1686 43 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 5 5447 38 REPOSITIONING LIDOCAINE AS AN ANTICANCER DRUG: THE ROLE BEYOND ANESTHESIA. WHILE CANCER TREATMENT HAS IMPROVED DRAMATICALLY, IT HAS ALSO ENCOUNTERED MANY CRITICAL CHALLENGES, SUCH AS DISEASE RECURRENCE, METASTASIS, AND DRUG RESISTANCE, MAKING NEW DRUGS WITH NOVEL MECHANISMS AN URGENT CLINICAL NEED. THE TERM "DRUG REPOSITIONING," ALSO KNOWN AS OLD DRUGS FOR NEW USES, HAS EMERGED AS ONE PRACTICAL STRATEGY TO DEVELOP NEW ANTICANCER DRUGS. ANESTHETICS HAVE BEEN WIDELY USED IN SURGICAL PROCEDURES TO REDUCE THE EXCRUCIATING PAIN. LIDOCAINE, ONE OF THE MOST-USED LOCAL ANESTHETICS IN CLINICAL SETTINGS, HAS BEEN FOUND TO SHOW MULTI-ACTIVITIES, INCLUDING POTENTIAL IN CANCER TREATMENT. GROWING EVIDENCE SHOWS THAT LIDOCAINE MAY NOT ONLY WORK AS A CHEMOSENSITIZER THAT SENSITIZES OTHER CONVENTIONAL CHEMOTHERAPEUTICS TO CERTAIN RESISTANT CANCER CELLS, BUT ALSO COULD SUPPRESS CANCER CELLS GROWTH BY SINGLE USE AT DIFFERENT DOSES OR CONCENTRATIONS. LIDOCAINE COULD SUPPRESS CANCER CELL GROWTH IN VITRO AND IN VIVO VIA MULTIPLE MECHANISMS, SUCH AS REGULATING EPIGENETIC CHANGES AND PROMOTING PRO-APOPTOSIS PATHWAYS, AS WELL AS REGULATING ABC TRANSPORTERS, METASTASIS, AND ANGIOGENESIS, ETC., PROVIDING VALUABLE INFORMATION FOR ITS FURTHER APPLICATION IN CANCER TREATMENT AND FOR NEW DRUG DISCOVERY. IN ADDITION, LIDOCAINE IS NOW UNDER CLINICAL TRIALS TO TREAT CERTAIN TYPES OF CANCER. IN THE CURRENT REVIEW, WE SUMMARIZE THE RESEARCH AND ANALYZE THE UNDERLYING MECHANISMS, AND ADDRESS KEY ISSUES IN THIS AREA. 2020 6 5038 23 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 7 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 8 3855 28 IS THERE ANY THERAPEUTIC VALUE FOR THE USE OF HISTONE DEACETYLASE INHIBITORS FOR CHRONIC PAIN? CHRONIC PAIN IS A COMPLEX CLINICAL CONDITION THAT REDUCES THE QUALITY OF LIFE FOR BILLIONS OF PEOPLE. IN RECENT YEARS, THE ROLE OF EPIGENETIC MODULATION IN THE CONTROL OF LONG-TERM NEURONAL PLASTICITY HAS ATTRACTED THE ATTENTION OF PAIN RESEARCHERS. THE EPIGENETIC MECHANISMS INCLUDE COVALENT MODIFICATIONS OF DNA AND/OR HISTONE PROTEINS. MOUNTING EVIDENCE SUGGESTS THAT THE ACTIVITY OF HISTONE DEACETYLASES (HDACS) AND LEVELS OF HISTONE ACETYLATION ARE DYNAMIC AND THAT THESE ENZYMES MODULATE PAIN-RELATED SYNAPTIC PLASTICITY. THEREFORE, HDACS PLAY ESSENTIAL ROLES IN CHRONIC PAIN DEVELOPMENT AND MAINTENANCE. IN THIS MINI REVIEW, WE WILL DISCUSS THE ROLE OF HDACS IN THE PATHOGENESIS OF CHRONIC PAIN AND WILL CONSIDER THE THERAPEUTIC VALUE OF HDAC INHIBITORS IN TREATING CHRONIC PAIN. 2016 9 2551 40 EPIGENETICS IN PAIN AND ANALGESIA: AN IMMINENT RESEARCH FIELD. HERITABLE PHENOTYPES RESULTING FROM ENVIRONMENT-CAUSED CHANGES IN A CHROMOSOME WITHOUT ALTERATIONS IN THE DNA SEQUENCE ARE INCREASINGLY RECOGNIZED AS A BASIS OF PERSONALIZED THERAPY. EPIGENETIC MECHANISMS INCLUDE COVALENT MODIFICATIONS OF THE DNA (METHYLATION) OR OF THE DNA-PACKAGING HISTONES (E.G., DEACETYLATION OR PHOSPHORYLATION). IN ADDITION, REGULATORY NON-CODING RNA MOLECULES (MICRO-RNAS) EXERT EPIGENETIC ACTIONS. THIS LEADS TO DISRUPTION OR OTHERWISE MODIFIED EXPRESSION OF GENES. ENVIRONMENTAL INFLUENCES SUCH AS NUTRITIONAL FACTORS, EXPOSURE TO CHEMICALS OR DRUGS, BUT ALSO SOCIAL FACTORS APPEAR TO EXERT EPIGENETIC ACTIONS. HISTONE MODIFICATIONS AND DNA METHYLATION ARE ASSOCIATED WITH THE SUBJECT'S AGE. EPIGENETIC MECHANISMS CAN SILENCE THE EXPRESSION OF PRO- OR ANTINOCICEPTIVE GENES. TO THE EPIGENETIC CONTROL OF NOCICEPTION ADDS ITS CONTROL OF THE PHARMACODYNAMICS OR PHARMACOKINETICS OF ANALGESICS BY EPIGENETIC CONTROL OF DRUG TARGETS AND ANALGESICS METABOLIZING ENZYMES. ALTHOUGH EPIGENETICS-BASED STRATEGIES FOR PAIN THERAPY ARE NOT YET AVAILABLE, EXPERIMENTS IN RODENTS SUGGEST THAT RNA INTERFERENCE MAY BECOME A NEW THERAPY APPROACH FOR NEUROPATHIC AND OTHER PAIN. ANOTHER EPIGENETIC APPROACH TO ANALGESIC TREATMENT EMPLOYS INHIBITORS OF HISTONE DEACETYLASE THAT ACT ON THE EPIGENOME BY INDIRECTLY REMODELING THE SPATIAL CONFORMATION OF THE CHROMATIN. FINALLY, EPIGENETIC TECHNIQUES SUCH AS RNA INTERFERENCE HAVE BEEN EMPLOYED IN PAIN RESEARCH TO PROOF THE CONTRIBUTION OF CERTAIN PROTEINS TO NOCICEPTION. THUS, THE NEW FIELD OF EPIGENETICS BECOMES INCREASINGLY USED IN RESEARCH AND MANAGEMENT OF PAIN AND WILL COMPLEMENT GENETICS. THIS ARTICLE INTRODUCES EPIGENETICS TO PAIN AND SUMMARIZES THE CURRENT AND FUTURE UTILITY. 2011 10 6226 16 THE LINK BETWEEN EPIGENETICS, PAIN SENSITIVITY AND CHRONIC PAIN. INCREASING EVIDENCE SUGGESTS AN ASSOCIATION BETWEEN GENE EXPRESSION AND CLINICAL PAIN. EPIGENETIC MODIFICATIONS ARE THE MAIN MODULATORS OF GENE EXPRESSION OR PROTEIN TRANSLATION IN RESPONSE TO ENVIRONMENTAL STIMULI AND PATHOPHYSIOLOGICAL CONDITIONS. PRECLINICAL AND CLINICAL STUDIES INDICATE THAT EPIGENETIC MODIFICATIONS COULD ALSO IMPACT THE DEVELOPMENT OF PAIN, THE TRANSITION FROM ACUTE TO CHRONIC PAIN, AND THE MAINTENANCE HEREOF. 2022 11 6130 26 THE EPIGENETIC REGULATION OF THE OPIOID SYSTEM: NEW INDIVIDUALIZED PROMPT PREVENTION AND TREATMENT STRATEGIES. THE MOST WELL-KNOWN PHYSIOLOGICAL EFFECT ASSOCIATED WITH OPIOD SYSTEM IS THEIR EFFICACY IN PAIN REDUCTION OR ANALGESIA, ALTHOUGH THEIR EFFECT ON A VARIETY OF OTHER PHYSIOLOGICAL AND PHYSIOPHOLOGICAL FUNCTIONS HAS BECOME APPARENT IN RECENT YEARS. THIS REVIEW IS AN ATTEMPT TO CLARIFY IN MORE DETAIL THE EPIGENETIC REGULATION OF OPIOID SYSTEM TO UNDERSTAND WITH MORE PRECISION THEIR TRANSCRIPTIONAL AND POSTTRANSCRIPTIONAL REGULATION IN MULTIPLE PYISIOLOGICAL AND PHARMACOLOGICAL CONTEXTS. THE OPIOID RECEPTORS SHOW AN EPIGENETIC REGULATION AND OPIOID PEPTIDE PRECURSORS BY METHYLATION, CHROMATIN REMODELING AND MICRORNA. ALTHOUGH THE OPIOID RECEPTOR PROMOTERS HAVE SIMILARITY BETWEEN THEM, THEY USE DIFFERENT EPIGENETIC REGULATION FORMS AND THEY EXHIBIT DIFFERENT PATTERN OF EXPRESSION DURING THE CELL DIFFERENTIATION. DNA METHYLATION IS ALSO CONFIRMED IN OPIOID PEPTIDE PRECURSORS, BEING IMPORTANT FOR GENE EXPRESSION AND TISSUE SPECIFICITY. UNDERSTANDING THE EPIGENETIC BASIS OF THOSE PHYSIOLOGICAL AND PHYSIOPATHOLOGICAL PROCESESS IS ESSENTIAL FOR THE DEVELOPMENT OF INDIVIDUALIZED PROMPT PREVENTION AND TREATMENT STRATEGIES. 2015 12 1204 39 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 13 5288 30 PROSPECTS FOR EPIGENETIC COMPOUNDS IN THE TREATMENT OF AUTOIMMUNE DISEASE. THERE IS GROWING EVIDENCE FOR A ROLE FOR EPIGENETIC MECHANISMS IN THE DEVELOPMENT OF AUTOIMMUNE DISEASES. IN MOST CASES OFAUTOIMMUNE DISEASE THE PRECISE EPIGENETIC MECHANISM INVOLVED REMAINS TO BE RESOLVED, HOWEVER DNA HYPOMETHYLATION ACCOMPANIED BY HYPOACETYLATION OFHISTONE H3/H4 IS COMMONLY OBSERVED. DUE TO THE REVERSIBLE NATURE OF EPIGENETIC MARKS THEIR MAINTENANCE ENZYMES SUCH AS DNA METHYLTRANSFERASES (DNMTS), HISTONE DEACETYLASES (HDACS) AND HISTONE LYSINE METHYLTRANSFERASES (HKMT) ARE ATTRACTIVE DRUG TARGETS. SMALL MOLECULE INHIBITORS OF HISTONE MODIFICATION AND DNA METHYLATION MAINTENANCE ARE INCREASINGLY BECOMING AVAILABLE AND WILL BE USEFUL CHEMICAL BIOLOGICAL TOOLS TO DISSECT EPIGENETIC MECHANISMS IN THESE DISEASES. HOWEVER, ALTHOUGH EPIGENETIC THERAPIES USED IN CANCER TREATMENT ARE A PROMISING STARTING POINT FOR THE EXPLORATION OF AUTOIMMUNE DISEASE TREATMENT, THERE IS A REQUIREMENT FOR MORE SPECIFIC AND LESS TOXIC AGENTS FOR THESE CHRONIC DISEASES OR FOR USE AS CHEMOPREVENTATIVE AGENTS. 2011 14 2611 33 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 15 2586 30 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 16 5562 34 ROLE OF HISTONE DEACETYLASES IN PANCREAS: IMPLICATIONS FOR PATHOGENESIS AND THERAPY. IN THE LAST YEARS, OUR KNOWLEDGE OF THE PATHOGENESIS IN ACUTE AND CHRONIC PANCREATITIS (AP/CP) AS WELL AS IN PANCREATIC CANCEROGENESIS HAS SIGNIFICANTLY DIVERSIFIED. NEVERTHELESS, THE MEDICINAL THERAPEUTIC OPTIONS ARE STILL LIMITED AND THERAPEUTIC SUCCESS AND PATIENT OUTCOME ARE POOR. EPIGENETIC DEREGULATION OF GENE EXPRESSION IS KNOWN TO CONTRIBUTE TO DEVELOPMENT AND PROGRESSION OF AP AND CP AS WELL AS OF PANCREATIC CANCER. THEREFORE, THE SELECTIVE INHIBITION OF ABERRANTLY ACTIVE EPIGENETIC REGULATORS CAN BE AN EFFECTIVE OPTION FOR FUTURE THERAPIES. HISTONE DEACETYLASES (HDACS) ARE ENZYMES THAT REMOVE AN ACETYL GROUP FROM HISTONE TAILS, THEREBY CAUSING CHROMATIN COMPACTION AND REPRESSION OF TRANSCRIPTION. IN THIS REVIEW WE PRESENT AN OVERVIEW OF THE CURRENTLY AVAILABLE LITERATURE ADDRESSING THE ROLE OF HDACS IN THE PANCREAS AND IN PANCREATIC DISEASES. IN PANCREATIC CANCEROGENESIS, HDACS PLAY A ROLE IN THE IMPORTANT PROCESS OF EPITHELIAL-MESENCHYMAL-TRANSITION, UBIQUITIN-PROTEASOME PATHWAY AND, HYPOXIA-INDUCIBLE-FACTOR-1-ANGIOGENESIS. FINALLY, WE FOCUS ON HDACS AS POTENTIAL THERAPEUTIC TARGETS BY SUMMARIZING CURRENTLY AVAILABLE HISTONE DEACETYLASE INHIBITORS. 2015 17 6061 35 THE DEVELOPMENT PROSPECTION OF HDAC INHIBITORS AS A POTENTIAL THERAPEUTIC DIRECTION IN ALZHEIMER'S DISEASE. ALZHEIMER'S DISEASE (AD) IS A CHRONIC NEURODEGENERATIVE DISEASE, WHICH IS ASSOCIATED WITH LEARNING AND MEMORY IMPAIRMENT IN THE ELDERLY. RECENT STUDIES HAVE FOUND THAT TREATING AD IN THE WAY OF CHROMATIN REMODELING VIA HISTONE ACETYLATION IS A PROMISING THERAPEUTIC REGIMEN. IN A NUMBER OF RECENT STUDIES, INHIBITORS OF HISTONE DEACETYLASE (HDACS) HAVE BEEN FOUND TO BE A NOVEL PROMISING THERAPEUTIC AGENTS FOR NEUROLOGICAL DISORDERS, PARTICULARLY FOR AD AND OTHER NEURODEGENERATIVE DISEASES. ALTHOUGH HDAC INHIBITORS HAVE THE ABILITY TO AMELIORATE COGNITIVE IMPAIRMENT, SUCCESSFUL TREATMENTS IN THE CLASSIC AD ANIMAL MODEL ARE RARELY TRANSLATED INTO CLINICAL TRIALS. AS FOR THE REDUCTION OF UNWANTED SIDE EFFECTS, THE DEVELOPMENT OF HDAC INHIBITORS WITH INCREASED ISOFORM SELECTIVITY OR SEEKING OTHER DIRECTIONS IS A KEY ISSUE THAT NEEDS TO BE ADDRESSED. THE REVIEW FOCUSED ON LITERATURES ON EPIGENETIC MECHANISMS IN RECENT YEARS, ESPECIALLY ON HISTONE ACETYLATION IN TERMS OF THE ENHANCEMENT OF SPECIFICITY, EFFICACY AND AVOIDING SIDE EFFECTS FOR TREATING AD. 2017 18 6802 20 [EPIGENETIC MECHANISMS IN MODELS OF CHRONIC PAIN - A TARGET FOR NOVEL THERAPY?]. EVIDENCE OF EPIGENETICS' ROLE IN PAIN RESPONSE IS ACCUMULATING IN RECENT YEARS. TIGHTLY REGULATED EPIGENETIC ALTERATIONS ON DNA AND HISTONES IN THE SENSORY CIRCUIT SHAPE THE PHYSIOLOGICAL RESPONSE TO INJURY. ALTERING THOSE EPIGENETIC PROCESSES HINDERS THERAPEUTIC POTENTIAL IN PAIN. THIS REVIEW PROVIDES AN OVERVIEW OF EPIGENOMIC MODIFICATION IN THE DEVELOPMENT OF CHRONIC PAIN, AND SUMMARIZES THE THERAPEUTIC POTENTIAL TO ALTER EPIGENETIC PROCESSES. 2018 19 5928 26 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 20 2176 21 EPIGENETIC MECHANISMS OF CHRONIC PAIN. NEUROPATHIC AND INFLAMMATORY PAIN PROMOTE A LARGE NUMBER OF PERSISTING ADAPTATIONS AT THE CELLULAR AND MOLECULAR LEVEL, ALLOWING EVEN TRANSIENT TISSUE OR NERVE DAMAGE TO ELICIT CHANGES IN CELLS THAT CONTRIBUTE TO THE DEVELOPMENT OF CHRONIC PAIN AND ASSOCIATED SYMPTOMS. THERE IS EVIDENCE THAT INJURY-INDUCED CHANGES IN CHROMATIN STRUCTURE DRIVE STABLE CHANGES IN GENE EXPRESSION AND NEURAL FUNCTION, WHICH MAY CAUSE SEVERAL SYMPTOMS, INCLUDING ALLODYNIA, HYPERALGESIA, ANXIETY, AND DEPRESSION. RECENT FINDINGS ON EPIGENETIC CHANGES IN THE SPINAL CORD AND BRAIN DURING CHRONIC PAIN MAY GUIDE FUNDAMENTAL ADVANCES IN NEW TREATMENTS. HERE, WE PROVIDE A BRIEF OVERVIEW OF EPIGENETIC REGULATION IN THE NERVOUS SYSTEM AND THEN DISCUSS THE STILL-LIMITED LITERATURE THAT DIRECTLY IMPLICATES EPIGENETIC MODIFICATIONS IN CHRONIC PAIN SYNDROMES. 2015