1 4518 105 MULTI-OMICS FOR BIOMARKER APPROACHES IN THE DIAGNOSTIC EVALUATION AND MANAGEMENT OF ABDOMINAL PAIN AND IRRITABLE BOWEL SYNDROME: WHAT LIES AHEAD. RELIABLE BIOMARKERS FOR COMMON DISORDERS OF GUT-BRAIN INTERACTION CHARACTERIZED BY ABDOMINAL PAIN, INCLUDING IRRITABLE BOWEL SYNDROME (IBS), ARE CRITICALLY NEEDED TO ENHANCE CARE AND DEVELOP INDIVIDUALIZED THERAPIES. THE DYNAMIC AND HETEROGENEOUS NATURE OF THE PATHOPHYSIOLOGICAL MECHANISMS THAT UNDERLIE VISCERAL HYPERSENSITIVITY HAVE CHALLENGED SUCCESSFUL BIOMARKER DEVELOPMENT. CONSEQUENTLY, EFFECTIVE THERAPIES FOR PAIN IN IBS ARE LACKING. HOWEVER, RECENT ADVANCES IN MODERN OMICS TECHNOLOGIES OFFER NEW OPPORTUNITIES TO ACQUIRE DEEP BIOLOGICAL INSIGHTS INTO MECHANISMS OF PAIN AND NOCICEPTION. NEWER METHODS FOR LARGE-SCALE DATA INTEGRATION OF COMPLEMENTARY OMICS APPROACHES HAVE FURTHER EXPANDED OUR ABILITY TO BUILD A HOLISTIC UNDERSTANDING OF COMPLEX BIOLOGICAL NETWORKS AND THEIR CO-CONTRIBUTIONS TO ABDOMINAL PAIN. HERE, WE REVIEW THE MECHANISMS OF VISCERAL HYPERSENSITIVITY, FOCUSING ON IBS. WE DISCUSS CANDIDATE BIOMARKERS FOR PAIN IN IBS IDENTIFIED THROUGH SINGLE OMICS STUDIES AND SUMMARIZE EMERGING MULTI-OMICS APPROACHES FOR DEVELOPING NOVEL BIOMARKERS THAT MAY TRANSFORM CLINICAL CARE FOR PATIENTS WITH IBS AND ABDOMINAL PAIN. 2023 2 5835 32 STRESS-INDUCED VISCERAL PAIN: TOWARD ANIMAL MODELS OF IRRITABLE-BOWEL SYNDROME AND ASSOCIATED COMORBIDITIES. VISCERAL PAIN IS A GLOBAL TERM USED TO DESCRIBE PAIN ORIGINATING FROM THE INTERNAL ORGANS, WHICH IS DISTINCT FROM SOMATIC PAIN. IT IS A HALLMARK OF FUNCTIONAL GASTROINTESTINAL DISORDERS SUCH AS IRRITABLE-BOWEL SYNDROME (IBS). CURRENTLY, THE TREATMENT STRATEGIES TARGETING VISCERAL PAIN ARE UNSATISFACTORY, WITH DEVELOPMENT OF NOVEL THERAPEUTICS HINDERED BY A LACK OF DETAILED KNOWLEDGE OF THE UNDERLYING MECHANISMS. STRESS HAS LONG BEEN IMPLICATED IN THE PATHOPHYSIOLOGY OF VISCERAL PAIN IN BOTH PRECLINICAL AND CLINICAL STUDIES. HERE, WE DISCUSS THE COMPLEX ETIOLOGY OF VISCERAL PAIN REVIEWING OUR CURRENT UNDERSTANDING IN THE CONTEXT OF THE ROLE OF STRESS, GENDER, GUT MICROBIOTA ALTERATIONS, AND IMMUNE FUNCTIONING. FURTHERMORE, WE REVIEW THE ROLE OF GLUTAMATE, GABA, AND EPIGENETIC MECHANISMS AS POSSIBLE THERAPEUTIC STRATEGIES FOR THE TREATMENT OF VISCERAL PAIN FOR WHICH THERE IS AN UNMET MEDICAL NEED. MOREOVER, WE DISCUSS THE MOST WIDELY DESCRIBED RODENT MODELS USED TO MODEL VISCERAL PAIN IN THE PRECLINICAL SETTING. THE THEORY BEHIND, AND APPLICATION OF, ANIMAL MODELS IS KEY FOR BOTH THE UNDERSTANDING OF UNDERLYING MECHANISMS AND DESIGN OF FUTURE THERAPEUTIC INTERVENTIONS. TAKEN TOGETHER, IT IS APPARENT THAT STRESS-INDUCED VISCERAL PAIN AND ITS PSYCHIATRIC COMORBIDITIES, AS TYPIFIED BY IBS, HAS A MULTIFACETED ETIOLOGY. MOREOVER, TREATMENT STRATEGIES STILL LAG FAR BEHIND WHEN COMPARED TO OTHER PAIN MODALITIES. THE DEVELOPMENT OF NOVEL, EFFECTIVE, AND SPECIFIC THERAPEUTICS FOR THE TREATMENT OF VISCERAL PAIN HAS NEVER BEEN MORE PERTINENT. 2015 3 4673 41 NEW INSIGHTS INTO THE PATHOGENESIS AND TREATMENT OF IRRITABLE BOWEL SYNDROME. IRRITABLE BOWEL SYNDROME (IBS) IS ONE OF THE MOST COMMON FUNCTIONAL GASTROINTESTINAL DISORDERS (FGID), CHARACTERIZED BY ABDOMINAL PAIN AND A CHANGE IN STOOL FORM THAT CANNOT BE EXPLAINED BY STRUCTURAL ABNORMALITIES. ITS PREVALENCE RANGES FROM 9 TO 23% OF THE WORLDWIDE POPULATION. THE PATHOPHYSIOLOGY OF IBS IS DIVERSE AND NOT WELL UNDERSTOOD. BIOPSYCHOSOCIAL CONCEPT ASSUMES THAT THE DISEASE IS A PRODUCT OF PSYCHOSOCIAL FACTORS AND ALTERED AT MULTIPLE LEVELS OF GUT PHYSIOLOGY INTERACTIONS. SOME AETIOLOGICAL FACTORS HAVE BEEN IDENTIFIED, YET. ONE OF THE MOST IMPORTANT IS THE DISRUPTION OF BRAIN-GUT MUTUAL COMMUNICATION THAT LEADS TO VISCERAL HYPERSENSITIVITY. ALSO GENETIC AND EPIGENETIC FACTORS ARE INVOLVED. CHRONIC STRESS MAY PREDISPOSE TO IBS AS WELL AS EXACERBATE ITS SYMPTOMS. BOTH QUANTITATIVE AND QUALITATIVE DISORDERS OF THE GUT MICROBIOTA ARE OBSERVED. THERE IS ALSO A RELATIONSHIP BETWEEN THE IBS SYMPTOMS AND THE INTAKE OF A SPECIFIC TYPE OF FOOD PRODUCTS. IN THE DIARRHOEA TYPE OF IBS THE ROLE OF PREVIOUS GASTROINTESTINAL INFECTION IS DEMONSTRATED. RECENT STUDIES HAVE SUGGESTED THAT VISCERAL HYPERSENSITIVITY IN PATIENTS WITH IBS MAY BE SECONDARY TO THE ACTIVATION OF THE IMMUNE CELLS AND LOW-GRADE INFLAMMATION. CLINICAL SYMPTOMS OF IBS INCLUDE ABDOMINAL PAIN AND CHANGE IN BOWEL HABITS AS WELL AS SOMATIC AND PSYCHIATRIC COMORBIDITIES. IBS IS DIAGNOSED ON THE BASIS OF ROME DIAGNOSTIC CRITERIA. RECENTLY, THEIR NEWEST VERSION (ROME IV) HAS BEEN PRESENTED. THE AIM OF THIS REVIEW IS TO SUMMARIZE THE PAST DECADE PROGRESS IN IBS DIAGNOSIS, MAIN PATHOPHYSIOLOGICAL ASPECTS AND THERAPEUTIC MANAGEMENT STRATEGY. 2017 4 2167 34 EPIGENETIC MECHANISMS IN IRRITABLE BOWEL SYNDROME. IRRITABLE BOWEL SYNDROME (IBS) IS A BRAIN-GUT AXIS DISORDER CHARACTERIZED BY ABDOMINAL PAIN AND ALTERED BOWEL HABITS. IBS IS A MULTIFACTORIAL, STRESS-SENSITIVE DISORDER WITH EVIDENCE FOR FAMILIAL CLUSTERING ATTRIBUTED TO GENETIC OR SHARED ENVIRONMENTAL FACTORS. HOWEVER, THERE ARE WEAK GENETIC ASSOCIATIONS REPORTED WITH IBS AND A LACK OF EVIDENCE TO SUGGEST THAT MAJOR GENETIC FACTOR(S) CONTRIBUTE TO IBS PATHOPHYSIOLOGY. STUDIES ON ANIMAL MODELS OF STRESS, INCLUDING EARLY LIFE STRESS, SUGGEST A ROLE FOR ENVIRONMENTAL FACTORS, SPECIFICALLY, STRESS ASSOCIATED WITH DYSREGULATION OF CORTICOTROPIN RELEASING FACTOR AND HYPOTHALAMUS-PITUITARY-ADRENAL (HPA) AXIS PATHWAYS IN THE PATHOPHYSIOLOGY OF IBS. RECENT EVIDENCE SUGGESTS THAT EPIGENETIC MECHANISMS, WHICH CONSTITUTE MOLECULAR CHANGES NOT DRIVEN BY A CHANGE IN GENE SEQUENCE, CAN MEDIATE ENVIRONMENTAL EFFECTS ON CENTRAL AND PERIPHERAL FUNCTION. EPIGENETIC ALTERATIONS INCLUDING DNA METHYLATION CHANGES, HISTONE MODIFICATIONS, AND DIFFERENTIAL EXPRESSION OF NON-CODING RNAS (MICRORNA [MIRNA] AND LONG NON-CODING RNA) HAVE BEEN ASSOCIATED WITH SEVERAL DISEASES. THE OBJECTIVE OF THIS REVIEW IS TO ELUCIDATE THE MOLECULAR FACTORS IN THE PATHOPHYSIOLOGY OF IBS WITH AN EMPHASIS ON EPIGENETIC MECHANISMS. EMERGING EVIDENCE FOR EPIGENETIC CHANGES IN IBS INCLUDES CHANGES IN DNA METHYLATION IN ANIMAL MODELS OF IBS AND PATIENTS WITH IBS, AND VARIOUS MIRNAS THAT HAVE BEEN ASSOCIATED WITH IBS AND ENDOPHENOTYPES, SUCH AS INCREASED VISCERAL SENSITIVITY AND INTESTINAL PERMEABILITY. DNA METHYLATION, IN PARTICULAR, IS AN EMERGING FIELD IN THE REALM OF COMPLEX DISEASES AND A PROMISING MECHANISM WHICH CAN PROVIDE IMPORTANT INSIGHTS INTO IBS PATHOGENESIS AND IDENTIFY POTENTIAL TARGETS FOR TREATMENT. 2020 5 4428 23 MOLECULAR BASIS OF THE IRRITABLE BOWEL SYNDROME. IRRITABLE BOWEL SYNDROME (IBS) IS A FUNCTIONAL DISORDER CHARACTERIZED BY ABDOMINAL PAIN, DISCOMFORT AND BLOATING. THE PATHOPHYSIOLOGY OF IBS IS POORLY UNDERSTOOD, BUT THE PRESENCE OF PSYCHOSOCIAL BASIS IS NOW KNOWN. THERE IS AN INCREASING NUMBER OF PUBLICATIONS SUPPORTING THE ROLE OF GENETICS IN IBS. MOST OF THE VARIATIONS ARE FOUND IN GENES ASSOCIATED WITH THE BRAIN-GUT AXIS, REVEALING THE STRONG CORRELATION OF BRAIN-GUT AXIS AND IBS. MIRNAS, WHICH PLAY CRITICAL ROLES IN PHYSIOLOGICAL PROCESSES, ARE NOT WELL STUDIED IN IBS. HOWEVER, SO FAR THERE IS FOUND AN INVOLVEMENT OF ALTERATIONS IN MIRNA EXPRESSION OR SEQUENCE, IN IBS SYMPTOMS. IBS PHENOTYPE IS AFFECTED BY EPIGENETIC ALTERATION AND ENVIRONMENT. CHANGES IN DNA AND HISTONE METHYLATION ARE OBSERVED IN PATIENTS WHO SUFFERED CHILDHOOD TRAUMA OR ABUSE, RESULTING IN ALTERED GENE EXPRESSION, SUCH AS THE GLUCOCORTICOID RECEPTOR GENE. FINALLY, DIET IS ANOTHER FACTOR ASSOCIATED WITH IBS, WHICH MAY CONTRIBUTE TO SYMPTOM ONSET. CERTAIN FOODS MAY AFFECT ON BACTERIAL METABOLISM AND EPIGENETIC MODIFICATIONS, PREDISPOSING TO IBS. 2014 6 6254 25 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 7 105 30 A REVIEW OF MICROBIOTA AND IRRITABLE BOWEL SYNDROME: FUTURE IN THERAPIES. IRRITABLE BOWEL SYNDROME (IBS), ONE OF THE MOST FREQUENT DIGESTIVE DISORDERS, IS CHARACTERIZED BY CHRONIC AND RECURRENT ABDOMINAL PAIN AND ALTERED BOWEL HABIT. THE ORIGIN SEEMS TO BE MULTIFACTORIAL AND IS STILL NOT WELL DEFINED FOR THE DIFFERENT SUBTYPES. GENETIC, EPIGENETIC AND SEX-RELATED MODIFICATIONS OF THE FUNCTIONING OF THE NERVOUS AND IMMUNE-ENDOCRINE SUPERSYSTEMS AND REGULATION OF BRAIN-GUT PHYSIOLOGY AND BILE ACID PRODUCTION AND ABSORPTION ARE CERTAINLY INVOLVED. ACQUIRED PREDISPOSITION MAY ACT IN CONJUNCTION WITH INFECTIOUS, TOXIC, DIETARY AND LIFE EVENT-RELATED FACTORS TO ENHANCE EPITHELIAL PERMEABILITY AND ELICIT MUCOSAL MICROINFLAMMATION, IMMUNE ACTIVATION AND DYSBIOSIS. NOTABLY, STRONG EVIDENCE SUPPORTS THE ROLE OF BACTERIAL, VIRAL AND PARASITIC INFECTIONS IN TRIGGERING IBS, AND TARGETING MICROBIOTA SEEMS PROMISING IN VIEW OF THE POSITIVE RESPONSE TO MICROBIOTA-RELATED THERAPIES IN SOME PATIENTS. HOWEVER, THE LACK OF HIGHLY PREDICTIVE DIAGNOSTIC BIOMARKERS AND THE COMPLEXITY AND HETEROGENEITY OF IBS PATIENTS MAKE MANAGEMENT DIFFICULT AND UNSATISFACTORY IN MANY CASES, REDUCING PATIENT HEALTH-RELATED QUALITY OF LIFE AND INCREASING THE SANITARY BURDEN. THIS ARTICLE REVIEWS SPECIFIC ALTERATIONS AND INTERVENTIONS TARGETING THE GUT MICROBIOTA IN IBS, INCLUDING PREBIOTICS, PROBIOTICS, SYNBIOTICS, NON-ABSORBABLE ANTIBIOTICS, DIETS, FECAL TRANSPLANTATION AND OTHER POTENTIAL FUTURE APPROACHES USEFUL FOR THE DIAGNOSIS, PREVENTION AND TREATMENT OF IBS. 2018 8 1291 33 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 9 2932 23 GENES AND EPIGENETIC PROCESSES AS PROSPECTIVE PAIN TARGETS. CHRONIC PAIN AFFECTS APPROXIMATELY ONE IN FIVE ADULTS, RESULTING IN A GREATLY REDUCED QUALITY OF LIFE AND A HIGHER RISK OF DEVELOPING CO-MORBIDITIES SUCH AS DEPRESSION. AVAILABLE TREATMENTS OFTEN PROVIDE INADEQUATE PAIN RELIEF, BUT IT IS HOPED THAT THROUGH DEEPER UNDERSTANDING OF THE MOLECULAR MECHANISMS UNDERLYING CHRONIC PAIN STATES WE CAN DISCOVER NEW AND IMPROVED THERAPIES. ALTHOUGH GENETIC RESEARCH HAS FLOURISHED OVER THE PAST DECADE AND HAS IDENTIFIED MANY KEY GENES IN PAIN PROCESSING, THE BUDDING FIELD OF EPIGENETICS PROMISES TO PROVIDE NEW INSIGHTS AND A MORE DYNAMIC VIEW OF PAIN REGULATION. THIS REVIEW GIVES AN OVERVIEW OF BASIC MECHANISMS AND CURRENT THERAPIES TO TREAT PAIN, AND DISCUSSES THE CLINICAL AND PRECLINICAL EVIDENCE FOR THE CONTRIBUTION OF GENETIC AND EPIGENETIC FACTORS, WITH A FOCUS ON HOW THIS KNOWLEDGE CAN AFFECT DRUG DEVELOPMENT. 2013 10 5028 19 PERSONALIZING PEDIATRIC PAIN MEDICINE: USING POPULATION-SPECIFIC PHARMACOGENETICS, GENOMICS, AND OTHER -OMICS APPROACHES TO PREDICT RESPONSE. PERSONALIZED MEDICINE IS THE SCIENCE OF INDIVIDUALIZED PREVENTION AND THERAPY. THE NOTION THAT "ONE SIZE FITS ALL" HAS BEEN REPLACED BY THE IDEA OF PATIENT-TAILORED HEALTH CARE. WITHIN THIS PARADIGM, THE RESEARCH COMMUNITY HAS TURNED TO EXAMINE GENETIC PREDICTORS OF DISEASE AND TREATMENT RESPONSES. PAIN RESEARCHERS HAVE PRODUCED GENETIC STUDIES OVER THE LAST DECADE THAT EVALUATE THE ASSOCIATION OF GENETIC VARIABILITY WITH PAIN SENSITIVITY AND ANALGESIC RESPONSE. WHILE MOST OF THESE STUDIES HAVE BEEN CONDUCTED AMONG COHORTS OF SUBJECTS OF EUROPEAN DESCENT, SOME HAVE INCLUDED OTHER RACIAL AND ETHNIC GROUPS, PROVIDING EVIDENCE OF VARIABLE RESPONSES TO ANALGESICS. SIMULTANEOUSLY, THERE IS AN INCREASED RECOGNITION REGARDING THE COMPLEXITY OF PAIN RESEARCH, ACKNOWLEDGING THE ADDITIONAL ROLE OF EPIGENETIC, TRANSCRIPTOMIC, PROTEOMIC, AND METABOLOMIC FACTORS IN THE DEVELOPMENT, EXPERIENCE, AND TREATMENT OF PAIN. THIS ARTICLE PROVIDES AN INTRODUCTION TO POPULATION-SPECIFIC PHARMACOGENETICS, PROTEOMICS AND OTHER "-OMICS" TECHNOLOGIES TO PREDICT DRUG RESPONSE TO PAIN MEDICATIONS IN CHILDREN. IT AIMS TO PROVIDE ANESTHESIOLOGISTS WITH THE BASIC KNOWLEDGE TO UNDERSTAND THE POTENTIAL IMPLICATIONS OF GENETIC AND EPIGENETIC FACTORS MANAGING THE PAIN OF PEDIATRIC PATIENTS. 2015 11 1248 29 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 12 6260 23 THE MOLECULAR NEUROBIOLOGY OF CHRONIC PAIN-INDUCED DEPRESSION. THE INCREASING NUMBER OF INDIVIDUALS WITH COMORBIDITIES POSES AN URGENT NEED TO IMPROVE THE MANAGEMENT OF PATIENTS WITH MULTIPLE CO-EXISTING DISEASES. AMONG THESE COMORBIDITIES, CHRONIC PAIN AND MOOD DISORDERS, TWO LONG-LASTING DISABLING CONDITIONS THAT SIGNIFICANTLY REDUCE THE QUALITY OF LIFE, COULD BE CITED FIRST. THE RECENT DEVELOPMENT OF ANIMAL MODELS ACCELERATED THE STUDIES FOCUSING ON THE UNDERLYING MECHANISMS OF THE CHRONIC PAIN AND DEPRESSION/ANXIETY COMORBIDITY. THIS REVIEW PROVIDES AN OVERVIEW OF CLINICAL AND PRE-CLINICAL STUDIES PERFORMED OVER THE PAST TWO DECADES ADDRESSING THE MOLECULAR ASPECTS OF THE COMORBID RELATIONSHIP OF CHRONIC PAIN AND DEPRESSION. WE THUS FOCUSED ON THE STUDIES THAT INVESTIGATED THE MOLECULAR CHARACTERISTICS OF THE COMORBID RELATIONSHIP BETWEEN CHRONIC PAIN AND MOOD DISORDERS, ESPECIALLY MAJOR DEPRESSIVE DISORDERS, FROM THE GENETIC AND EPIGENETIC POINT OF VIEW TO KEY NEUROMODULATORS WHICH HAVE BEEN SHOWN TO PLAY AN IMPORTANT ROLE IN THIS COMORBIDITY. 2019 13 5926 35 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 14 1314 33 DELINEATING CONDITIONS AND SUBTYPES IN CHRONIC PAIN USING NEUROIMAGING. DIFFERENTIATING SUBTYPES OF CHRONIC PAIN STILL REMAINS A CHALLENGE-BOTH FROM A SUBJECTIVE AND OBJECTIVE POINT OF VIEW. PERSONALIZED MEDICINE IS THE CURRENT GOAL OF MODERN MEDICAL CARE AND IS LIMITED BY THE SUBJECTIVE NATURE OF PATIENT SELF-REPORTING OF SYMPTOMS AND BEHAVIORAL EVALUATION. PHYSIOLOGY-FOCUSED TECHNIQUES SUCH AS GENOME AND EPIGENETIC ANALYSES INFORM THE DELINEATION OF PAIN GROUPS; HOWEVER, EXCEPT UNDER RARE CIRCUMSTANCES, THEY HAVE DILUTED EFFECTS THAT AGAIN, SHARE A COMMON RELIANCE ON BEHAVIORAL EVALUATION. THE APPLICATION OF STRUCTURAL NEUROIMAGING TOWARDS DISTINGUISHING PAIN SUBTYPES IS A GROWING FIELD AND MAY INFORM PAIN-GROUP CLASSIFICATION THROUGH THE ANALYSIS OF BRAIN REGIONS SHOWING HYPERTROPHIC AND ATROPHIC CHANGES IN THE PRESENCE OF PAIN. ANALYTICAL TECHNIQUES SUCH AS MACHINE-LEARNING CLASSIFIERS HAVE THE CAPACITY TO PROCESS LARGE VOLUMES OF DATA AND DELINEATE DIAGNOSTICALLY RELEVANT INFORMATION FROM NEUROIMAGING ANALYSIS. THE ISSUE OF DEFINING A "BRAIN TYPE" IS AN EMERGING FIELD AIMED AT INTERPRETING OBSERVED BRAIN CHANGES AND DELINEATING THEIR CLINICAL IDENTITY/SIGNIFICANCE. IN THIS REVIEW, 2 CHRONIC PAIN CONDITIONS (MIGRAINE AND IRRITABLE BOWEL SYNDROME) WITH SIMILAR CLINICAL PHENOTYPES ARE COMPARED IN TERMS OF THEIR STRUCTURAL NEUROIMAGING FINDINGS. INDEPENDENT INVESTIGATIONS ARE COMPARED WITH FINDINGS FROM APPLICATION OF MACHINE-LEARNING ALGORITHMS. FINDINGS ARE DISCUSSED IN TERMS OF DIFFERENTIATING PATIENT SUBGROUPS USING NEUROIMAGING DATA IN PATIENTS WITH CHRONIC PAIN AND HOW THEY MAY BE APPLIED TOWARDS DEFINING A PERSONALIZED PAIN SIGNATURE THAT HELPS SEGREGATE PATIENT SUBGROUPS (EG, MIGRAINE WITH AND WITHOUT AURA, WITH OR WITHOUT NAUSEA; IRRITABLE BOWEL SYNDROME VS OTHER FUNCTIONAL GASTROINTESTINAL DISORDERS). 2019 15 4911 22 PAIN IMAGING: FUTURE APPLICATIONS TO INTEGRATIVE CLINICAL AND BASIC NEUROBIOLOGY. WE HAVE ENTERED A NEW ERA IN UNDERSTANDING CNS CIRCUITRY INVOLVED IN ACUTE AND CHRONIC PAIN. THE ABILITY TO OBJECTIVELY MEASURE A PAIN OR ANALGESIC STATE OF THE BRAIN USING NON-INVASIVE METHODS THAT DEFINE NEURAL ACTIVATION PROVIDES THE POSSIBILITY FOR TOP-DOWN APPROACHES TO DRUG DISCOVERY. THESE BRAIN MAPS REPRESENT THE SPECIFIC BRAIN STATE. IN THE FUTURE, CORRELATIONS WITH SUCH STATES AND BEHAVIORAL, GENETIC, EPIGENETIC OR OTHER CHEMICAL MARKERS MAY HELP DEFINE SPECIFIC DIAGNOSTIC TOOLS AND NOVEL APPROACHES TO DRUG DISCOVERY. 2003 16 5038 19 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 17 6375 29 THE ROLE OF NEURO-IMMUNE INTERACTION IN CHRONIC PAIN CONDITIONS; FUNCTIONAL SOMATIC SYNDROME, NEUROGENIC INFLAMMATION, AND PERIPHERAL NEUROPATHY. FUNCTIONAL SOMATIC SYNDROMES ARE INCREASINGLY DIAGNOSED IN CHRONICALLY ILL PATIENTS PRESENTING WITH AN ARRAY OF SYMPTOMS NOT ATTRIBUTED TO PHYSICAL AILMENTS. CONDITIONS SUCH AS CHRONIC FATIGUE SYNDROME, FIBROMYALGIA SYNDROME, OR IRRITABLE BOWEL SYNDROME ARE COMMON DISORDERS THAT BELONG IN THIS BROAD CATEGORY. SUCH SYNDROMES ARE CHARACTERISED BY THE PRESENCE OF ONE OR MULTIPLE CHRONIC SYMPTOMS INCLUDING WIDESPREAD MUSCULOSKELETAL PAIN, FATIGUE, SLEEP DISORDERS, AND ABDOMINAL PAIN, AMONGST OTHER ISSUES. SYMPTOMS ARE BELIEVED TO RELATE TO A COMPLEX INTERACTION OF BIOLOGICAL AND PSYCHOSOCIAL FACTORS, WHERE A DEFINITE AETIOLOGY HAS NOT BEEN ESTABLISHED. THEORIES SUGGEST CAUSATIVE PATHWAYS BETWEEN THE IMMUNE AND NERVOUS SYSTEMS OF AFFECTED INDIVIDUALS WITH SEVERAL RISK FACTORS IDENTIFIED IN PATIENTS PRESENTING WITH ONE OR MORE FUNCTIONAL SYNDROMES. RISK FACTORS INCLUDING STRESS AND CHILDHOOD TRAUMA ARE NOW RECOGNISED AS IMPORTANT CONTRIBUTORS TO CHRONIC PAIN CONDITIONS. EMOTIONAL, PHYSICAL, AND SEXUAL ABUSE DURING CHILDHOOD IS CONSIDERED A SEVERE STRESSOR HAVING A HIGH PREVALENCE IN FUNCTIONAL SOMATIC SYNDROME SUFFERS. SUCH TRAUMA PERMANENTLY ALTERS THE BIOLOGICAL STRESS RESPONSE OF THE SUFFERS LEADING TO NEUROEXCITATORY AND OTHER NERVE ISSUES ASSOCIATED WITH CHRONIC PAIN IN ADULTS. TRAUMATIC AND CHRONIC STRESS RESULTS IN EPIGENETIC CHANGES IN STRESS RESPONSE GENES, WHICH ULTIMATELY LEADS TO DYSREGULATION OF THE HYPOTHALAMIC-PITUITARY AXIS, THE AUTONOMIC NERVOUS SYSTEM, AND THE IMMUNE SYSTEM MANIFESTING IN A BROAD ARRAY OF SYMPTOMS. IMPORTANTLY, THESE SYSTEMS ARE KNOWN TO BE DYSREGULATED IN PATIENTS SUFFERING FROM FUNCTIONAL SOMATIC SYNDROME. FUNCTIONAL SOMATIC SYNDROMES ARE ALSO HIGHLY PREVALENT CO-MORBIDITIES OF PSYCHIATRIC CONDITIONS, MOOD DISORDERS, AND ANXIETY. CONSEQUENTLY, THIS REVIEW AIMS TO PROVIDE INSIGHT INTO THE ROLE OF THE NERVOUS SYSTEM AND IMMUNE SYSTEM IN CHRONIC PAIN DISORDERS ASSOCIATED WITH THE MUSCULOSKELETAL SYSTEM, AND CENTRAL AND PERIPHERAL NERVOUS SYSTEMS. 2022 18 4144 29 MECHANISMS OF STRESS-INDUCED VISCERAL PAIN. EVIDENCE SUGGESTS THAT LONG-TERM STRESS FACILITATES VISCERAL PAIN THROUGH SENSITIZATION OF PAIN PATHWAYS AND PROMOTES CHRONIC VISCERAL PAIN DISORDERS SUCH AS THE IRRITABLE BOWEL SYNDROME (IBS). THIS REVIEW WILL DESCRIBE THE IMPORTANCE OF STRESS IN EXACERBATING IBS-INDUCED ABDOMINAL PAIN. ADDITIONALLY, WE WILL BRIEFLY REVIEW OUR UNDERSTANDING OF THE ACTIVATION OF THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS BY BOTH CHRONIC ADULT STRESS AND FOLLOWING EARLY LIFE STRESS IN THE PATHOGENESIS OF IBS. THE REVIEW WILL FOCUS ON THE GLUCOCORTICOID RECEPTOR AND CORTICOTROPIN-RELEASING HORMONE-MEDIATED MECHANISMS IN THE AMYGDALA INVOLVED IN STRESS-INDUCED VISCERAL HYPERSENSITIVITY. ONE POTENTIAL MECHANISM UNDERLYING PERSISTENT EFFECTS OF STRESS ON VISCERAL SENSITIVITY COULD BE EPIGENETIC MODULATION OF GENE EXPRESSION. WHILE THERE ARE RELATIVELY FEW STUDIES EXAMINING EPIGENETICALLY MEDIATED MECHANISMS INVOLVED IN STRESS-INDUCED VISCERAL NOCICEPTION, ALTERATIONS IN DNA METHYLATION AND HISTONE ACETYLATION PATTERNS WITHIN THE BRAIN, HAVE BEEN LINKED TO ALTERATIONS IN NOCICEPTIVE SIGNALING VIA INCREASED EXPRESSION OF PRO-NOCICEPTIVE NEUROTRANSMITTERS. THIS REVIEW WILL DISCUSS THE LATEST STUDIES INVESTIGATING THE LONG-TERM EFFECTS OF STRESS ON VISCERAL SENSITIVITY. ADDITIONALLY, WE WILL CRITICALLY REVIEW THE IMPORTANCE OF EXPERIMENTAL MODELS OF ADULT STRESS AND EARLY LIFE STRESS IN ENHANCING OUR UNDERSTANDING OF THE BASIC MOLECULAR MECHANISMS OF NOCICEPTIVE PROCESSING. 2018 19 4591 29 NARRATIVE REVIEW OF THE COMPLEX INTERACTION BETWEEN PAIN AND TRAUMA IN CHILDREN: A FOCUS ON BIOLOGICAL MEMORY, PRECLINICAL DATA, AND EPIGENETIC PROCESSES. THE INCIDENCE AND COLLECTIVE IMPACT OF EARLY ADVERSE EXPERIENCES, TRAUMA, AND PAIN CONTINUE TO INCREASE. THIS UNDERSCORES THE URGENT NEED FOR TRANSLATIONAL EFFORTS BETWEEN CLINICAL AND PRECLINICAL RESEARCH TO BETTER UNDERSTAND THE UNDERLYING MECHANISMS AND DEVELOP EFFECTIVE THERAPEUTIC APPROACHES. AS OUR UNDERSTANDING OF THESE ISSUES IMPROVES FROM STUDIES IN CHILDREN AND ADOLESCENTS, WE CAN CREATE MORE PRECISE PRECLINICAL MODELS AND ULTIMATELY TRANSLATE OUR FINDINGS BACK TO CLINICAL PRACTICE. A MULTIDISCIPLINARY APPROACH IS ESSENTIAL FOR ADDRESSING THE COMPLEX AND WIDE-RANGING EFFECTS OF THESE EXPERIENCES ON INDIVIDUALS AND SOCIETY. THIS NARRATIVE REVIEW AIMS TO (1) DEFINE PAIN AND TRAUMA EXPERIENCES IN CHILDHOOD AND ADOLESCENTS, (2) DISCUSS THE RELATIONSHIP BETWEEN PAIN AND TRAUMA, (3) CONSIDER THE ROLE OF BIOLOGICAL MEMORY, (4) DECIPHER THE RELATIONSHIP BETWEEN PAIN AND TRAUMA USING PRECLINICAL DATA, AND (5) EXAMINE THE ROLE OF THE ENVIRONMENT BY INTRODUCING THE IMPORTANCE OF EPIGENETIC PROCESSES. THE ULTIMATE SCOPE IS TO BETTER UNDERSTAND THE WIDE-RANGING EFFECTS OF TRAUMA, ABUSE, AND CHRONIC PAIN ON CHILDREN AND ADOLESCENTS, HOW THEY OCCUR, AND HOW TO PREVENT OR MITIGATE THEIR EFFECTS AND DEVELOP EFFECTIVE TREATMENT STRATEGIES THAT ADDRESS BOTH THE UNDERLYING CAUSES AND THE ASSOCIATED PHYSIOLOGICAL AND PSYCHOLOGICAL EFFECTS. 2023 20 2526 31 EPIGENETICS APPLIED TO PSYCHIATRY: CLINICAL OPPORTUNITIES AND FUTURE CHALLENGES. PSYCHIATRIC DISORDERS ARE CLINICALLY HETEROGENEOUS AND DEBILITATING CHRONIC DISEASES RESULTING FROM A COMPLEX INTERPLAY BETWEEN GENE VARIANTS AND ENVIRONMENTAL FACTORS. EPIGENETIC PROCESSES, SUCH AS DNA METHYLATION AND HISTONE POSTTRANSLATIONAL MODIFICATIONS, INSTRUCT THE CELL/TISSUE TO CORRECTLY INTERPRET EXTERNAL SIGNALS AND ADJUST ITS FUNCTIONS ACCORDINGLY. GIVEN THAT EPIGENETIC MODIFICATIONS ARE SENSITIVE TO ENVIRONMENT, STABLE, AND REVERSIBLE, EPIGENETIC STUDIES IN PSYCHIATRY COULD REPRESENT A PROMISING APPROACH TO BETTER UNDERSTANDING AND TREATING DISEASE. IN THE PRESENT REVIEW, WE AIM TO DISCUSS THE CLINICAL OPPORTUNITIES AND CHALLENGES ARISING FROM THE EPIGENETIC RESEARCH IN PSYCHIATRY. USING SELECTED EXAMPLES, WE FIRST RECAPITULATE KEY FINDINGS SUPPORTING THE ROLE OF ADVERSE LIFE EVENTS, ALONE OR IN COMBINATION WITH GENETIC RISK, IN EPIGENETIC PROGRAMMING OF NEUROPSYCHIATRIC SYSTEMS. EPIGENETIC STUDIES FURTHER REPORT ENCOURAGING FINDINGS ABOUT THE USE OF METHYLATION CHANGES AS DIAGNOSTIC MARKERS OF DISEASE PHENOTYPE AND PREDICTIVE TOOLS OF PROGRESSION AND RESPONSE TO TREATMENT. THEN WE DISCUSS THE POTENTIAL OF USING TARGETED EPIGENETIC PHARMACOTHERAPY, COMBINED WITH PSYCHOSOCIAL INTERVENTIONS, FOR FUTURE PERSONALIZED MEDICINE FOR PATIENTS. FINALLY, WE REVIEW THE METHODOLOGICAL LIMITATIONS THAT COULD HINDER INTERPRETATION OF EPIGENETIC DATA IN PSYCHIATRY. THEY MAINLY ARISE FROM HETEROGENEITY AT THE INDIVIDUAL AND TISSUE LEVEL AND REQUIRE FUTURE STRATEGIES IN ORDER TO REINFORCE THE BIOLOGICAL RELEVANCE OF EPIGENETIC DATA AND ITS TRANSLATIONAL USE IN PSYCHIATRY. OVERALL, WE SUGGEST THAT EPIGENETICS COULD PROVIDE NEW INSIGHTS INTO A MORE COMPREHENSIVE INTERPRETATION OF MENTAL ILLNESS AND MIGHT EVENTUALLY IMPROVE THE NOSOLOGY, TREATMENT, AND PREVENTION OF PSYCHIATRIC DISORDERS. 2018