1 2198 136 EPIGENETIC MODIFICATION OF DRG NEURONAL GENE EXPRESSION SUBSEQUENT TO NERVE INJURY: ETIOLOGICAL CONTRIBUTION TO COMPLEX REGIONAL PAIN SYNDROMES (PART I). DRG IS OF IMPORTANCE IN RELAYING PAINFUL STIMULATION TO THE HIGHER PAIN CENTERS AND THEREFORE COULD BE A CRUCIAL TARGET FOR EARLY INTERVENTION AIMED AT SUPPRESSING PRIMARY AFFERENT STIMULATION. COMPLEX REGIONAL PAIN SYNDROME (CRPS) IS A COMMON PAIN CONDITION WITH AN UNKNOWN ETIOLOGY. RECENTLY ADDED NEW INFORMATION ENRICHES OUR UNDERSTANDING OF CRPS PATHOPHYSIOLOGY. RESEARCHES ON GENETICS, BIOGENIC AMINES, NEUROTRANSMITTERS, AND MECHANISMS OF PAIN MODULATION, CENTRAL SENSITIZATION, AND AUTONOMIC FUNCTIONS IN CRPS REVEALED VARIOUS ABNORMALITIES INDICATING THAT MULTIPLE FACTORS AND MECHANISMS ARE INVOLVED IN THE PATHOGENESIS OF CRPS. EPIGENETICS REFERS TO MITOTICALLY AND MEIOTICALLY HERITABLE CHANGES IN GENE EXPRESSION THAT DO NOT AFFECT THE DNA SEQUENCE. AS EPIGENETIC MODIFICATIONS POTENTIALLY PLAY AN IMPORTANT ROLE IN INFLAMMATORY CYTOKINE METABOLISM, NEUROTRANSMITTER RESPONSIVENESS, AND ANALGESIC SENSITIVITY, THEY ARE LIKELY KEY FACTORS IN THE DEVELOPMENT OF CHRONIC PAIN. IN THIS DYAD REVIEW SERIES, WE SYSTEMATICALLY EXAMINE THE NERVE INJURY-RELATED CHANGES IN THE NEUROLOGICAL SYSTEM AND THEIR CONTRIBUTION TO CRPS. IN THIS PART, WE FIRST REVIEWED AND SUMMARIZED THE ROLE OF NEURAL SENSITIZATION IN DRG NEURONS IN PERFORMING FUNCTION IN THE CONTEXT OF PAIN PROCESSING. PARTICULAR EMPHASIS IS PLACED ON THE CELLULAR AND MOLECULAR CHANGES AFTER NERVE INJURY AS WELL AS DIFFERENT MODELS OF INFLAMMATORY AND NEUROPATHIC PAIN. THESE WERE CONSIDERED AS THE POTENTIAL MOLECULAR BASES THAT UNDERLIE NERVE INJURY-ASSOCIATED PATHOGENESIS OF CRPS. 2014 2 2199 53 EPIGENETIC MODIFICATION OF DRG NEURONAL GENE EXPRESSION SUBSEQUENT TO NERVE INJURY: ETIOLOGICAL CONTRIBUTION TO COMPLEX REGIONAL PAIN SYNDROMES (PART II). CUMULATING EVIDENCE INDICATED THAT NERVE INJURY-ASSOCIATED CELLULAR AND MOLECULAR CHANGES PLAY AN ESSENTIAL ROLE IN CONTRIBUTING TO THE DEVELOPMENT OF PATHOLOGICAL PAIN, AND MORE RECENT FINDINGS IMPLICATED THE CRITICAL ROLE OF EPIGENETIC MECHANISMS IN PAIN-RELATED SENSITIZATION IN THE DRG SUBSEQUENT TO NERVE INJURY. IN THIS PART OF THE DYAD REVIEW (PART II), WE REVIEWED AND PAID SPECIAL ATTENTION ON THE ETIOLOGICAL CONTRIBUTION OF DGR GENE EXPRESSION MODULATED BY EPIGENETIC MECHANISMS OF CRPS. AS ESSENTIAL EFFECTORS TO DIFFERENT MOLECULAR ACTIVATION, WE FIRST DISCUSSED THE ACTIVATION OF VARIOUS SIGNALING PATHWAYS THAT SUBSEQUENTLY FROM NERVE INJURY, AND IN FURTHER ILLUSTRATED THE FUNDAMENTAL AND FUNCTIONAL UNDERPINNINGS OF NERVE INJURY-INDUCED PAIN, IN WHICH WE ARGUED FOR THE POTENTIAL EPIGENETIC MECHANISMS IN RESPONSE TO SENSITIZING STIMULI OR INJURY. THEREFORE, UNDERSTANDING THE SPECIFIC MEDIATING FACTORS THAT INFLUENCE INDIVIDUAL EPIGENETIC DIFFERENCES CONTRIBUTING TO PAIN SENSITIVITY AND RESPONSIVENESS TO ANALGESICS POSSESSES CRUCIAL CLINICAL IMPLICATIONS. 2014 3 4586 32 NAFLD AT THE INTERFACE OF THE MOTHER-INFANT DYAD. THIS REVIEW AIMS TO FOCUS THE LINKS EXISTING BETWEEN SEVERAL ASPECTS OF THE MOTHER-CHILD DYAD IN THE INTRICATE PLAYGROUND OF OBESITY AND METABOLIC SYNDROME (METS), INCLUDING ITS HEPATIC COMPONENT, THE NON- ALCOHOLIC FATTY LIVER DISEASE (NAFLD). IN RECENT YEARS HUMAN AND ANIMAL MODEL STUDIES HAVE SHOWN THAT DIETARY INTERVENTIONS IN MOTHERS AND OFFSPRING CAN BE SUCCESSFUL IN REDUCING THE RISK OF NAFLD DEVELOPMENT. EVIDENCES ALSO CONCERN THE NEW CONCEPT OF A REAL INTERGENERATIONAL TRANSMISSION OF PREDISPOSITION TO METABOLIC DISORDERS. CERTAIN GENES, SUCH AS SIRT1 AND PNPLA3, AND SOME EPIGENETIC MODIFICATIONS, INCLUDING MICRO RNAS FUNCTION, SEEM TO BE RESPONSIBLE FOR FETAL REPROGRAMMING IN THE SETTING OF MATERNAL OBESITY. THESE MODIFIERS APPEAR TO BE POTENTIAL THERAPEUTIC TARGETS TO REDUCE THE RISK OF FUTURE METABOLIC DYSFUNCTIONS. CONTROLLING ANTEPARTUM HYPERGLYCEMIA, PREVENTING GESTATIONAL DIABETES, AND AVOIDING EXCESSIVE WEIGHT GAIN DURING PREGNANCY CAN HELP REDUCE THE RELENTLESS EPIDEMIC OF CHILDHOOD OBESITY AND NAFLD. ALSO, THE COMPOSITION OF THE INTESTINAL MICROBIOTA SEEMS TO BE RELATED TO THE DEVELOPMENT OF METABOLIC DISORDERS IN THE OFFSPRING. SEVERAL STUDIES SHOW THAT BREASTFED INFANTS HAVE A MICROBIAL SIGNATURE DIFFERENT FROM FORMULA-FED INFANTS. MUCH INTERESTINGLY, PROLONGED BREASTFEEDING IS BENEFICIAL NOT ONLY FOR THE NEWBORN AND HIS HEALTH IN ADULT LIFE, BUT ALSO FOR THE MOTHERS' HEALTH. MATERNAL BENEFITS INCLUDE REDUCING THE RISK OF DEVELOPING CHRONIC DISEASES, SUCH AS DIABETES MELLITUS, MYOCARDIAL INFARCTION AND NAFLD AS WELL. IN CONCLUSION, ALL ABOVE MECHANISMS APPEAR TO INTERVENE SYNERGISTICALLY AND MAY ACT AS MODIFIABLE RISK FACTORS FOR INFANT AND MOTHER NAFLD. 2020 4 4713 37 NON-CODING RNA AND N6-METHYLADENOSINE MODIFICATION PLAY CRUCIAL ROLES IN NEUROPATHIC PAIN. AFTER PERIPHERAL NERVE INJURY, PAIN SIGNALS ARE TRANSMITTED FROM PRIMARY SENSORY NEURONS IN THE DORSAL ROOT GANGLION (DRG) TO THE CENTRAL NERVOUS SYSTEM. EPIGENETIC MODIFICATION AFFECTS NEUROPATHIC PAIN THROUGH ALTERATIONS IN THE GENE EXPRESSION IN PAIN-RELATED AREAS AND GLIAL CELL ACTIVATION. RECENT STUDIES HAVE SHOWN THAT NON-CODING RNA AND N6-METHYLADENOSINE (M6A) METHYLATION MODIFICATION PLAY PIVOTAL REGULATORY ROLES IN THE OCCURRENCE AND MAINTENANCE OF NEUROPATHIC PAIN. DYSREGULATION OF THE RNA M6A LEVEL VIA DYNAMIC CHANGES IN METHYLTRANSFERASE AND DEMETHYLASE AFTER CENTRAL OR PERIPHERAL NERVE INJURY COMMONLY REGULATES PAIN-ASSOCIATED GENES, CONTRIBUTING TO THE INDUCTION AND MAINTENANCE OF NEUROPATHIC PAIN. THE DYNAMIC PROCESS HAS SIGNIFICANT IMPLICATIONS FOR THE DEVELOPMENT AND MAINTENANCE OF NEUROPATHIC PAIN. HOWEVER, THE UNDERLYING MECHANISMS BY WHICH NON-CODING RNA AND M6A RNA MODIFICATION REGULATE NEUROPATHIC PAIN ARE NOT WELL-CHARACTERIZED. THIS ARTICLE ELUCIDATES THE MULTIPLE MECHANISMS OF NON-CODING RNA AND M6A METHYLATION IN THE CONTEXT OF NEUROPATHIC PAIN, AND SUMMARIZES ITS POTENTIAL FUNCTIONS AS WELL AS RECENT ADVANCES. 2022 5 800 44 CELLULAR, MOLECULAR, AND EPIGENETIC MECHANISMS IN NON-ASSOCIATIVE CONDITIONING: IMPLICATIONS FOR PAIN AND MEMORY. SENSITIZATION IS A FORM OF NON-ASSOCIATIVE CONDITIONING IN WHICH AMPLIFICATION OF BEHAVIORAL RESPONSES CAN OCCUR FOLLOWING PRESENTATION OF AN AVERSIVE OR NOXIOUS STIMULUS. UNDERSTANDING THE CELLULAR AND MOLECULAR UNDERPINNINGS OF SENSITIZATION HAS BEEN AN OVERARCHING THEME SPANNING THE FIELD OF LEARNING AND MEMORY AS WELL AS THAT OF PAIN RESEARCH. IN THIS REVIEW WE EXAMINE HOW SENSITIZATION, BOTH IN THE CONTEXT OF LEARNING AS WELL AS PAIN PROCESSING, SHARES EVOLUTIONARILY CONSERVED BEHAVIORAL, CELLULAR/SYNAPTIC, AND EPIGENETIC MECHANISMS ACROSS PHYLA. FIRST, WE CHARACTERIZE THE BEHAVIORAL PHENOMENON OF SENSITIZATION BOTH IN INVERTEBRATES AND VERTEBRATES. PARTICULAR EMPHASIS IS PLACED ON LONG-TERM SENSITIZATION (LTS) OF WITHDRAWAL REFLEXES IN APLYSIA FOLLOWING AVERSIVE STIMULATION OR INJURY, ALTHOUGH ADDITIONAL INVERTEBRATE MODELS ARE ALSO COVERED. IN THE CONTEXT OF VERTEBRATES, SENSITIZATION OF MAMMALIAN HYPERAROUSAL IN A MODEL OF POST-TRAUMATIC STRESS DISORDER (PTSD), AS WELL AS MAMMALIAN MODELS OF INFLAMMATORY AND NEUROPATHIC PAIN IS CHARACTERIZED. SECOND, WE INVESTIGATE THE CELLULAR AND SYNAPTIC MECHANISMS UNDERLYING THESE BEHAVIORS. WE FOCUS OUR DISCUSSION ON SEROTONIN-MEDIATED LONG-TERM FACILITATION (LTF) AND AXOTOMY-MEDIATED LONG-TERM HYPEREXCITABILITY (LTH) IN REDUCED APLYSIA SYSTEMS, AS WELL AS MAMMALIAN SPINAL PLASTICITY MECHANISMS OF CENTRAL SENSITIZATION. THIRD, WE EXPLORE RECENT EVIDENCE IMPLICATING EPIGENETIC MECHANISMS IN LEARNING- AND PAIN-RELATED SENSITIZATION. THIS REVIEW ILLUSTRATES THE FUNDAMENTAL AND FUNCTIONAL OVERLAY OF THE LEARNING AND MEMORY FIELD WITH THE PAIN FIELD WHICH ARGUES FOR HOMOLOGOUS PERSISTENT PLASTICITY MECHANISMS IN RESPONSE TO SENSITIZING STIMULI OR INJURY ACROSS PHYLA. 2013 6 1243 26 CURRENT CONCEPTS IN CHRONIC INFLAMMATORY DISEASES: INTERACTIONS BETWEEN MICROBES, CELLULAR METABOLISM, AND INFLAMMATION. RECENT RESEARCH INDICATES THAT CHRONIC INFLAMMATORY DISEASES, INCLUDING ALLERGIES AND AUTOIMMUNE AND NEUROPSYCHIATRIC DISEASES, SHARE COMMON PATHWAYS OF CELLULAR AND MOLECULAR DYSREGULATION. IT WAS THE AIM OF THE INTERNATIONAL VON-BEHRING-RONTGEN SYMPOSIUM (OCTOBER 16-18, 2014, IN MARBURG, GERMANY) TO DISCUSS RECENT DEVELOPMENTS IN THIS FIELD. THESE INCLUDE A CONCEPT OF BIODIVERSITY; THE CONTRIBUTION OF URBANIZATION, LIFESTYLE FACTORS, AND NUTRITION (EG, VITAMIN D); AND NEW MECHANISMS OF METABOLIC AND IMMUNE DYSREGULATION, SUCH AS EXTRACELLULAR AND INTRACELLULAR RNAS AND CELLULAR AND MITOCHONDRIAL STRESS. EPIGENETIC MECHANISMS CONTRIBUTE FURTHER TO ALTERED GENE EXPRESSION AND THEREFORE TO THE DEVELOPMENT OF CHRONIC INFLAMMATION. THESE NOVEL FINDINGS PROVIDE THE FOUNDATION FOR FURTHER DEVELOPMENT OF PREVENTIVE AND THERAPEUTIC STRATEGIES. 2016 7 6254 34 THE MICROBIOME AND IRRITABLE BOWEL SYNDROME - A REVIEW ON THE PATHOPHYSIOLOGY, CURRENT RESEARCH AND FUTURE THERAPY. IRRITABLE BOWEL SYNDROME (IBS) IS A FUNCTIONAL DISORDER WHICH AFFECTS A LARGE PROPORTION OF THE POPULATION GLOBALLY. THE PRECISE ETIOLOGY OF IBS IS STILL UNKNOWN, ALTHOUGH CONSENSUS UNDERSTANDING PROPOSES IBS TO BE OF MULTIFACTORIAL ORIGIN WITH YET UNDEFINED SUBTYPES. GENETIC AND EPIGENETIC FACTORS, STRESS-RELATED NERVOUS AND ENDOCRINE SYSTEMS, IMMUNE DYSREGULATION AND THE BRAIN-GUT AXIS SEEM TO BE CONTRIBUTING FACTORS THAT PREDISPOSE INDIVIDUALS TO IBS. IN ADDITION TO FOOD HYPERSENSITIVITY, TOXINS AND ADVERSE LIFE EVENTS, CHRONIC INFECTIONS AND DYSBIOTIC GUT MICROBIOTA HAVE BEEN SUGGESTED TO TRIGGER IBS SYMPTOMS IN TANDEM WITH THE PREDISPOSING FACTORS. THIS REVIEW WILL SUMMARIZE THE PATHOPHYSIOLOGY OF IBS AND THE ROLE OF GUT MICROBIOTA IN RELATION TO IBS. CURRENT METHODOLOGIES FOR MICROBIOME STUDIES IN IBS SUCH AS GENOME SEQUENCING, METAGENOMICS, CULTUROMICS AND ANIMAL MODELS WILL BE DISCUSSED. THE MYRIAD OF THERAPY OPTIONS SUCH AS IMMUNOGLOBULINS (IMMUNE-BASED THERAPY), PROBIOTICS AND PREBIOTICS, DIETARY MODIFICATIONS INCLUDING FODMAP RESTRICTION DIET AND GLUTEN-FREE DIET, AS WELL AS FECAL TRANSPLANTATION WILL BE REVIEWED. FINALLY THIS REVIEW WILL HIGHLIGHT FUTURE DIRECTIONS IN IBS THERAPY RESEARCH, INCLUDING IDENTIFICATION OF NEW MOLECULAR TARGETS, APPLICATION OF 3-D GUT MODEL, GUT-ON-A-CHIP AND PERSONALIZED THERAPY. 2019 8 2053 41 EPIGENETIC CONNECTIONS OF THE TRPA1 ION CHANNEL IN PAIN TRANSMISSION AND NEUROGENIC INFLAMMATION - A THERAPEUTIC PERSPECTIVE IN MIGRAINE? PERSISTENT REPROGRAMMING OF EPIGENETIC PATTERN LEADS TO CHANGES IN GENE EXPRESSION OBSERVED IN MANY NEUROLOGICAL DISORDERS. TRANSIENT RECEPTOR POTENTIAL CATION CHANNEL SUBFAMILY A MEMBER 1 (TRPA1), A MEMBER OF THE TRP CHANNELS SUPERFAMILY, IS ACTIVATED BY MANY MIGRAINE TRIGGERS AND EXPRESSED IN TRIGEMINAL NEURONS AND BRAIN REGIONS THAT ARE IMPORTANT IN MIGRAINE PATHOGENESIS. TRP CHANNELS CHANGE NOXIOUS STIMULI INTO PAIN SIGNALS WITH THE INVOLVEMENT OF EPIGENETIC REGULATION. THE EXPRESSION OF THE TRPA1 ENCODING GENE, TRPA1, IS MODULATED IN PAIN-RELATED SYNDROMES BY EPIGENETIC ALTERATIONS, INCLUDING DNA METHYLATION, HISTONE MODIFICATIONS, AND EFFECTS OF NON-CODING RNAS: MICRO RNAS (MIRNAS), LONG NON-CODING RNAS, AND CIRCULAR RNAS. TRPA1 MAY CHANGE EPIGENETIC PROFILE OF MANY PAIN-RELATED GENES AS IT MAY MODIFY ENZYMES RESPONSIBLE FOR EPIGENETIC MODIFICATIONS AND EXPRESSION OF NON-CODING RNAS. TRPA1 MAY INDUCE THE RELEASE OF CALCITONIN GENE RELATED PEPTIDE (CGRP), FROM TRIGEMINAL NEURONS AND DURAL TISSUE. THEREFORE, EPIGENETIC REGULATION OF TRPA1 MAY PLAY A ROLE IN EFFICACY AND SAFETY OF ANTI-MIGRAINE THERAPIES TARGETING TRP CHANNELS AND CGRP. TRPA1 IS ALSO INVOLVED IN NEUROGENIC INFLAMMATION, IMPORTANT IN MIGRAINE PATHOGENESIS. THE FUNDAMENTAL ROLE OF TRPA1 IN INFLAMMATORY PAIN TRANSMISSION MAY BE EPIGENETICALLY REGULATED. IN CONCLUSION, EPIGENETIC CONNECTIONS OF TRPA1 MAY PLAY A ROLE IN EFFICACY AND SAFETY OF ANTI-MIGRAINE THERAPY TARGETING TRP CHANNELS OR CGRP AND THEY SHOULD BE FURTHER EXPLORED FOR EFFICIENT AND SAFE ANTIMIGRAINE TREATMENT. THIS NARRATIVE/PERSPECTIVE REVIEW PRESENTS INFORMATION ON THE STRUCTURE AND FUNCTIONS OF TRPA1 AS WELL AS ROLE OF ITS EPIGENETIC CONNECTIONS IN PAIN TRANSMISSION AND POTENTIAL IN MIGRAINE THERAPY. 2023 9 4619 40 NERVE TRAUMA-CAUSED DOWNREGULATION OF OPIOID RECEPTORS IN PRIMARY AFFERENT NEURONS: MOLECULAR MECHANISMS AND POTENTIAL MANAGEMENTS. NEUROPATHIC PAIN IS THE MOST COMMON CLINICAL DISORDER DESTROYING THE QUALITY OF PATIENT LIFE AND LEADING TO A MARKED ECONOMIC AND SOCIAL BURDEN. OPIOIDS ARE STILL LAST OPTION FOR PHARMACOLOGICAL TREATMENT OF THIS DISORDER, BUT THEIR ANTINOCICEPTIVE EFFECTS ARE LIMITED IN PART DUE TO THE DOWNREGULATION OF OPIOID RECEPTORS IN THE PRIMARY AFFERENT NEURONS AFTER PERIPHERAL NERVE TRAUMA. HOW THIS DOWNREGULATION OCCURS IS NOT COMPLETELY UNDERSTOOD, BUT RECENT STUDIES HAVE DEMONSTRATED THAT PERIPHERAL NERVE TRAUMA DRIVES THE ALTERATIONS IN EPIGENETIC MODIFICATIONS (INCLUDING DNA METHYLATION, HISTONE METHYLATION AND MCIRORNAS), EXPRESSION OF TRANSCRIPTION FACTORS, POST-TRANSCRIPTIONAL MODIFICATIONS (E.G., RNA METHYLATION) AND PROTEIN TRANSLATION INITIATION IN THE NEURONS OF NERVE TRAUMA-RELATED DORSAL ROOT GANGLION (DRG) AND THAT THESE ALTERNATIONS MAY BE ASSOCIATED WITH NERVE TRAUMA-CAUSED DOWNREGULATION OF DRG OPIOID RECEPTORS. THIS REVIEW PRESENTS HOW OPIOID RECEPTORS ARE DOWNREGULATED IN THE DRG AFTER PERIPHERAL NERVE TRAUMA, SPECIFICALLY FOCUSING ON DISTINCT MOLECULAR MECHANISMS UNDERLYING TRANSCRIPTIONAL AND TRANSLATIONAL PROCESSES. THIS REVIEW ALSO DISCUSSES HOW THIS DOWNREGULATION CONTRIBUTES TO THE INDUCTION AND MAINTENANCE OF NEUROPATHIC PAIN. A DEEPER UNDERSTANDING OF THESE MOLECULAR MECHANISMS LIKELY PROVIDES A NOVEL AVENUE FOR PREVENTION AND/OR TREATMENT OF NEUROPATHIC PAIN. 2021 10 2310 37 EPIGENETIC REGULATION OF CHRONIC PAIN. CHRONIC PAIN ARISING FROM PERIPHERAL INFLAMMATION AND TISSUE OR NERVE INJURY IS A COMMON CLINICAL SYMPTOM. ALTHOUGH INTENSIVE RESEARCH ON THE NEUROBIOLOGICAL MECHANISMS OF CHRONIC PAIN HAS BEEN CARRIED OUT DURING PREVIOUS DECADES, THIS DISORDER IS STILL POORLY MANAGED BY CURRENT DRUGS SUCH AS OPIOIDS AND NONSTEROIDAL ANTI-INFLAMMATORY DRUGS. INFLAMMATION, TISSUE INJURY AND/OR NERVE INJURY-INDUCED CHANGES IN GENE EXPRESSION IN SENSORY NEURONS OF THE DORSAL ROOT GANGLION, SPINAL CORD DORSAL HORN AND PAIN-ASSOCIATED BRAIN REGIONS ARE THOUGHT TO PARTICIPATE IN CHRONIC PAIN GENESIS; HOWEVER, HOW THESE CHANGES OCCUR IS STILL ELUSIVE. EPIGENETIC MODIFICATIONS INCLUDING DNA METHYLATION AND COVALENT HISTONE MODIFICATIONS CONTROL GENE EXPRESSION. RECENT STUDIES HAVE SHOWN THAT PERIPHERAL NOXIOUS STIMULATION CHANGES DNA METHYLATION AND HISTONE MODIFICATIONS AND THAT THESE CHANGES MAY BE RELATED TO THE INDUCTION OF PAIN HYPERSENSITIVITY UNDER CHRONIC PAIN CONDITIONS. THIS REVIEW SUMMARIZES THE CURRENT KNOWLEDGE AND PROGRESS IN EPIGENETIC RESEARCH IN CHRONIC PAIN AND DISCUSSES THE POTENTIAL ROLE OF EPIGENETIC MODIFICATIONS AS THERAPEUTIC ANTINOCICEPTIVE TARGETS IN THIS DISORDER. 2015 11 2179 39 EPIGENETIC MECHANISMS OF NEURAL PLASTICITY IN CHRONIC NEUROPATHIC PAIN. NEUROPATHIC PAIN IS A CHALLENGING CLINICAL PROBLEM AND REMAINS DIFFICULT TO TREAT. ALTERED GENE EXPRESSION IN PERIPHERAL SENSORY NERVES AND NEURONS DUE TO NERVE INJURY IS WELL DOCUMENTED AND CONTRIBUTES CRITICALLY TO THE SYNAPTIC PLASTICITY IN THE SPINAL CORD AND THE INITIATION AND MAINTENANCE OF CHRONIC PAIN. HOWEVER, OUR UNDERSTANDING OF THE EPIGENETIC MECHANISMS REGULATING THE TRANSCRIPTION OF PRO-NOCICEPTIVE (E.G., NMDA RECEPTORS AND ALPHA2DELTA-1) AND ANTINOCICEPTIVE (E.G., POTASSIUM CHANNELS AND OPIOID AND CANNABINOID RECEPTORS) GENES ARE STILL LIMITED. IN THIS REVIEW, WE SUMMARIZE RECENT STUDIES DETERMINING THE ROLES OF HISTONE MODIFICATIONS (INCLUDING METHYLATION, ACETYLATION, AND UBIQUITINATION), DNA METHYLATION, AND NONCODING RNAS IN NEUROPATHIC PAIN DEVELOPMENT. WE REVIEW THE EPIGENETIC WRITER, READER, AND ERASER PROTEINS THAT PARTICIPATE IN THE TRANSCRIPTIONAL CONTROL OF THE EXPRESSION OF KEY ION CHANNELS AND NEUROTRANSMITTER RECEPTORS IN THE DORSAL ROOT GANGLION AFTER TRAUMATIC NERVE INJURY, WHICH IS COMMONLY USED AS A PRECLINICAL MODEL OF NEUROPATHIC PAIN. A BETTER UNDERSTANDING OF EPIGENETIC REPROGRAMMING INVOLVED IN THE TRANSITION FROM ACUTE TO CHRONIC PAIN COULD LEAD TO THE DEVELOPMENT OF NEW TREATMENTS FOR NEUROPATHIC PAIN. 2022 12 6802 27 [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 13 3374 28 HISTONE POST-TRANSLATIONAL MODIFICATIONS AS POTENTIAL THERAPEUTIC TARGETS FOR PAIN MANAGEMENT. EFFECTIVE PHARMACOLOGICAL MANAGEMENT OF PAIN ASSOCIATED WITH TISSUE PATHOLOGY IS AN UNMET MEDICAL NEED. TRANSCRIPTIONAL MODIFICATIONS IN NOCICEPTIVE PATHWAYS ARE PIVOTAL FOR THE DEVELOPMENT AND THE MAINTENANCE OF PAIN ASSOCIATED WITH TISSUE DAMAGE. ACCUMULATING EVIDENCE HAS SHOWN THE IMPORTANCE OF THE EPIGENETIC CONTROL OF TRANSCRIPTION IN NOCICEPTIVE PATHWAYS VIA HISTONE POST-TRANSLATIONAL MODIFICATIONS (PTMS). HENCE, HISTONE PTMS COULD BE TARGETS FOR NOVEL EFFECTIVE ANALGESICS. HERE, WE DISCUSS THE CURRENT UNDERSTANDING OF HISTONE PTMS IN THE MODULATION OF GENE EXPRESSION AFFECTING NOCICEPTION AND PAIN PHENOTYPES FOLLOWING TISSUE INJURY. WE ALSO PROVIDE A CRITICAL VIEW OF THE TRANSLATIONAL IMPLICATIONS OF PRECLINICAL MODELS AND DISCUSS OPPORTUNITIES AND CHALLENGES OF TARGETING HISTONE PTMS TO RELIEVE PAIN IN CLINICALLY RELEVANT TISSUE INJURIES. 2021 14 4765 44 NRSF AND ITS EPIGENETIC EFFECTORS: NEW TREATMENTS FOR NEUROLOGICAL DISEASE. THE NEURON RESTRICTIVE SILENCER FACTOR (NRSF) IS THE WELL-KNOWN MASTER TRANSCRIPTIONAL REPRESSOR OF THE NEURONAL PHENOTYPE. RESEARCH TO DATE HAS SHOWN THAT IT IS AN IMPORTANT PLAYER IN THE GROWTH AND DEVELOPMENT OF THE NERVOUS SYSTEM. ITS ROLE IN THE MATURATION OF NEURAL PRECURSOR CELLS TO ADULT NEURONS HAS BEEN WELL CHARACTERIZED IN STEM CELL MODELS. WHILE MUCH HAS BEEN CHARACTERIZED FROM A DEVELOPMENTAL PERSPECTIVE, RESEARCH IS REVEALING THAT NRSF PLAYS A ROLE IN VARIOUS NEUROLOGICAL DISEASES, RANGING FROM NEURODEGENERATIVE, NEUROPSYCHIATRIC, TO CANCER. DYSREGULATION OF NRSF ACTIVITY DISRUPTS DOWNSTREAM GENE EXPRESSION THAT IS RESPONSIBLE FOR NEURONAL CELL HOMEOSTASIS IN SEVERAL MODELS THAT CONTRIBUTE TO PATHOLOGIC STATES. INTERESTINGLY, IT IS NOW BECOMING APPARENT THAT THE DYSREGULATION OF NRSF CONTRIBUTES TO NEUROLOGICAL DISEASE THROUGH EPIGENETIC MECHANISMS. ALTHOUGH NRSF ITSELF IS A TRANSCRIPTION FACTOR, ITS MAJOR EFFECTORS ARE CHROMATIN MODIFIERS. AT THE LEVEL OF EPIGENETICS, CHANGES IN NRSF ACTIVITY HAVE BEEN WELL CHARACTERIZED IN MODELS OF NEUROPATHIC PAIN AND EPILEPSY. BETTER UNDERSTANDING OF THE EPIGENETIC BASIS OF BRAIN DISEASES HAS LED TO DESIGN AND USE OF SMALL MOLECULES THAT CAN PREVENT NRSF FROM REPRESSING GENE EXPRESSION BY NEUTRALIZING ITS INTERACTIONS WITH ITS CHROMATIN REMODELERS. THIS REVIEW WILL ADDRESS THE BASIC FUNCTION OF NRSF AND ITS COFACTORS, INVESTIGATE THEIR MECHANISMS, THEN EXPLORE HOW THEIR DYSFUNCTION CAN CAUSE DISEASE STATES. THIS REVIEW WILL ALSO ADDRESS RESEARCH ON NRSF AS A THERAPEUTIC TARGET AND DELVE INTO NEW THERAPEUTIC STRATEGIES THAT FOCUS ON DISRUPTING NRSF'S ABILITY TO RECRUIT CHROMATIN REMODELERS. 2018 15 5876 31 SYNAPTIC PLASTICITY AND PAIN AVERSION. NEGATIVE AFFECTIVE EMOTIONS ARE DEFINED AS THE CONCEPTUAL FEATURE OF PAIN. A NUMBER OF CLINICAL AND ANIMAL STUDIES HAVE INDICATED THAT THE LIMBIC SYSTEM INCLUDING THE ANTERIOR CINGULATE CORTEX (ACC) AND AMYGDALA PLAYS A CRITICAL ROLE IN THE PROCESSING OF AFFECTIVE COMPONENTS OF PAIN. GLUTAMATERGIC TRANSMISSION PLAYS AN IMPORTANT ROLE IN THE PROCESSING OF AFFECTIVE ASPECTS OF PAIN. LONG-TERM CHANGES ON GLUTAMATERGIC SYNAPSES CONTRIBUTE TO THE EXPRESSION OF AVERSION BEHAVIOR INDUCED BY PAIN. IN THIS ARTICLE, THE NEUROCIRCUITS INVOLVED IN THE PROCESSING OF AFFECTIVE ASPECTS OF PAIN, THE GLUTAMATERGIC SYNAPTIC PLASTICITY IN THESE BRAIN REGIONS, AND THE EPIGENETIC MECHANISMS UNDERLYING PAIN-RELATED SYNAPTIC PLASTICITY WILL BE REVIEWED AND DISCUSSED. NEW DISCOVERIES REGARDING THE INTERACTION BETWEEN THE SYNAPTIC PLASTICITY AND AFFECTIVE COMPONENTS OF PAIN MAY ADVANCE OUR UNDERSTANDING ON THE PAIN MECHANISM, AND LEAD TO NEW STRATEGIES FOR PAIN TREATMENT. 2011 16 4338 35 MICROVASCULAR BARRIER PROTECTION BY MICRORNA-183 VIA FOXO1 REPRESSION: A PATHWAY DISTURBED IN NEUROPATHY AND COMPLEX REGIONAL PAIN SYNDROME. BLOOD NERVE BARRIER DISRUPTION AND EDEMA ARE COMMON IN NEUROPATHIC PAIN AS WELL AS IN COMPLEX REGIONAL PAIN SYNDROME (CRPS). MICRORNAS (MIRNA) ARE EPIGENETIC MULTITARGET SWITCHES CONTROLLING NEURONAL AND NON-NEURONAL CELLS IN PAIN. THE MIR-183 COMPLEX ATTENUATES HYPEREXCITABILITY IN NOCICEPTORS, BUT ADDITIONAL NON-NEURONAL EFFECTS VIA TRANSCRIPTION FACTORS COULD CONTRIBUTE AS WELL. THIS STUDY EXPLORED EXOSOMAL MIR-183 IN CRPS AND MURINE NEUROPATHY, ITS EFFECT ON THE MICROVASCULAR BARRIER VIA TRANSCRIPTION FACTOR FOXO1 AND TIGHT JUNCTION PROTEIN CLAUDIN-5, AND ITS ANTIHYPERALGESIC POTENTIAL. SCIATIC MIR-183 DECREASED AFTER CCI. SUBSTITUTION WITH PERINEURAL MIR-183 MIMIC ATTENUATED MECHANICAL HYPERSENSITIVITY AND RESTORED BLOOD NERVE BARRIER FUNCTION. IN VITRO, SERUM FROM CCI MICE UND CRPS PATIENTS WEAKENED THE MICROVASCULAR BARRIER OF MURINE CEREBELLAR ENDOTHELIAL CELLS, INCREASED ACTIVE FOXO1 AND REDUCED CLAUDIN-5, CONCOMITANT WITH A LACK OF EXOSOMAL MIR-183 IN CRPS PATIENTS. CELLULAR STRESS ALSO COMPROMISED THE MICROVASCULAR BARRIER WHICH WAS RESCUED EITHER BY MIR-183 MIMIC VIA FOXO1 REPRESSION OR BY PRIOR SILENCING OF FOXO1. PERSPECTIVE: LOW MIR-183 LEADING TO BARRIER IMPAIRMENT VIA FOXO1 AND SUBSEQUENT CLAUDIN-5 SUPPRESSION IS A NEW ASPECT IN THE PATHOPHYSIOLOGY OF CRPS AND NEUROPATHIC PAIN. THIS PATHWAY MIGHT HELP UNTANGLE THE WIDE SYMPTOMATIC RANGE OF CRPS AND NURTURE FURTHER RESEARCH INTO MIRNA MIMICS OR FOXO1 INHIBITORS. 2022 17 5369 32 RECENT ADVANCES IN UNDERSTANDING NEUROPATHIC PAIN: GLIA, SEX DIFFERENCES, AND EPIGENETICS. NEUROPATHIC PAIN RESULTS FROM DISEASES OR TRAUMA AFFECTING THE NERVOUS SYSTEM. THIS PAIN CAN BE DEVASTATING AND IS POORLY CONTROLLED. THE PATHOPHYSIOLOGY IS COMPLEX, AND IT IS ESSENTIAL TO UNDERSTAND THE UNDERLYING MECHANISMS IN ORDER TO IDENTIFY THE RELEVANT TARGETS FOR THERAPEUTIC INTERVENTION. IN THIS ARTICLE, WE FOCUS ON THE RECENT RESEARCH INVESTIGATING NEURO-IMMUNE COMMUNICATION AND EPIGENETIC PROCESSES, WHICH GAIN PARTICULAR ATTENTION IN THE CONTEXT OF NEUROPATHIC PAIN. SPECIFICALLY, WE ANALYZE THE ROLE OF GLIAL CELLS, INCLUDING MICROGLIA, ASTROCYTES, AND OLIGODENDROCYTES, IN THE MODULATION OF THE CENTRAL NERVOUS SYSTEM INFLAMMATION TRIGGERED BY NEUROPATHY. CONSIDERING EPIGENETICS, WE ADDRESS DNA METHYLATION, HISTONE MODIFICATIONS, AND THE NON-CODING RNAS IN THE REGULATION OF ION CHANNELS, G-PROTEIN-COUPLED RECEPTORS, AND TRANSMITTERS FOLLOWING NEURONAL DAMAGE. THE GOAL WAS NOT ONLY TO HIGHLIGHT THE EMERGING CONCEPTS BUT ALSO TO DISCUSS CONTROVERSIES, METHODOLOGICAL COMPLICATIONS, AND INTRIGUING OPINIONS. 2016 18 4795 33 NUTRITIONAL GENOMICS IN NONALCOHOLIC FATTY LIVER DISEASE. NONALCOHOLIC FATTY LIVER DISEASE (NAFLD) IS A COMMON CHRONIC CONDITION ASSOCIATED WITH GENETIC AND ENVIRONMENTAL FACTORS IN WHICH FAT ABNORMALLY ACCUMULATES IN THE LIVER. NAFLD IS EPIDEMIOLOGICALLY ASSOCIATED WITH OBESITY, TYPE 2 DIABETES, AND DYSLIPIDEMIA. ENVIRONMENTAL FACTORS, SUCH AS PHYSICAL INACTIVITY AND AN UNBALANCED DIET, INTERACT WITH GENETIC FACTORS, SUCH AS EPIGENETIC MECHANISMS AND POLYMORPHISMS FOR THE GENESIS AND DEVELOPMENT OF THE CONDITION. DIFFERENT GENETIC POLYMORPHISMS SEEM TO BE INVOLVED IN THIS CONTEXT, INCLUDING VARIANTS IN PNPLA3, TM6SF2, PEMT, AND CHDH GENES, PLAYING A ROLE IN THE DISEASE'S SUSCEPTIBILITY, DEVELOPMENT, AND SEVERITY. FROM CARBOHYDRATE INTAKE AND WEIGHT LOSS TO OMEGA-3 SUPPLEMENTATION AND CALORIC RESTRICTION, DIFFERENT DIETARY AND NUTRITIONAL FACTORS APPEAR TO BE INVOLVED IN CONTROLLING THE ONSET AND PROGRESSION OF NAFLD CONDITIONS INFLUENCING METABOLISM, GENE, AND PROTEIN EXPRESSION. THE POLYGENIC RISK SCORE REPRESENTS A SUM OF TRAIT-ASSOCIATED ALLELES CARRIED BY AN INDIVIDUAL AND SEEMS TO BE ASSOCIATED WITH NAFLD OUTCOMES DEPENDING ON THE DIETARY CONTEXT. UNDERSTANDING THE EXACT EXTENT TO WHICH LIFESTYLE INTERVENTIONS AND GENETIC PREDISPOSITIONS CAN PLAY A ROLE IN THE PREVENTION AND MANAGEMENT OF NAFLD CAN BE CRUCIAL FOR THE ESTABLISHMENT OF A PERSONALIZED AND INTEGRATIVE APPROACH TO PATIENTS. 2023 19 5545 38 ROLE OF EPIGENETIC MECHANISMS IN CHRONIC PAIN. PAIN IS AN UNPLEASANT BUT ESSENTIAL-TO-LIFE SENSATION, USUALLY RESULTING FROM TISSUE DAMAGE. WHEN PAIN PERSISTS LONG AFTER THE INJURY HAS RESOLVED, IT BECOMES PATHOLOGICAL. THE PRECISE MOLECULAR AND CELLULAR MECHANISMS CAUSING THE TRANSITION FROM ACUTE TO CHRONIC PAIN ARE NOT FULLY UNDERSTOOD. A KEY ASPECT OF PAIN CHRONICITY IS THAT SEVERAL PLASTICITY EVENTS HAPPEN ALONG THE NEURAL PATHWAYS INVOLVED IN PAIN. THESE LONG-LASTING ADAPTIVE CHANGES ARE ENABLED BY ALTERATION IN THE EXPRESSION OF RELEVANT GENES. AMONG THE DIFFERENT MODULATORS OF GENE TRANSCRIPTION IN ADAPTIVE PROCESSES IN THE NERVOUS SYSTEM, EPIGENETIC MECHANISMS PLAY A PIVOTAL ROLE. IN THIS REVIEW, I WILL FIRST OUTLINE THE MAIN CLASSES OF EPIGENETIC MEDIATORS AND THEN DISCUSS THEIR IMPLICATIONS IN CHRONIC PAIN. 2022 20 980 28 CHRONIC PAIN: EMERGING EVIDENCE FOR THE INVOLVEMENT OF EPIGENETICS. EPIGENETIC PROCESSES, SUCH AS HISTONE MODIFICATIONS AND DNA METHYLATION, HAVE BEEN ASSOCIATED WITH MANY NEURAL FUNCTIONS INCLUDING SYNAPTIC PLASTICITY, LEARNING, AND MEMORY. HERE, WE CRITICALLY EXAMINE EMERGING EVIDENCE LINKING EPIGENETIC MECHANISMS TO THE DEVELOPMENT OR MAINTENANCE OF CHRONIC PAIN STATES. ALTHOUGH IN ITS INFANCY, RESEARCH IN THIS AREA POTENTIALLY UNIFIES SEVERAL PATHOPHYSIOLOGICAL PROCESSES UNDERPINNING ABNORMAL PAIN PROCESSING AND OPENS UP A DIFFERENT AVENUE FOR THE DEVELOPMENT OF NOVEL ANALGESICS. 2012