1 232 94 ADAPTIVE PLASTICITY IN THE RETINA: PROTECTION AGAINST ACUTE INJURY AND NEURODEGENERATIVE DISEASE BY CONDITIONING STIMULI. ALTHOUGH BOTH PRECLINICAL AND CLINICAL CONDITIONING STUDIES IN HEART AND BRAIN LEAD THE FIELD OF CONDITIONING MEDICINE, INVESTIGATIONS OF RETINAL CONDITIONING STILL NUMBER MORE THAN 100. IN THIS BRIEF REVIEW, WE HIGHLIGHT FINDINGS TO DATE FROM ANIMAL AND CELL CULTURE MODELS OF CONDITIONING THAT PROVIDE DEMONSTRATED PROTECTION IN ACUTE AND CHRONIC RETINAL INJURY AND DISEASE MODELS. THE MULTITUDE OF STIMULI USED TO CONDITION THE RETINA, THE SIGNALING MEDIATORS AND PATHWAYS IDENTIFIED, AND THE INJURY- AND DISEASE-RESILIENT PHENOTYPES DOCUMENTED ARE DISCUSSED HEREIN, ALONG WITH OUR RECOMMENDATIONS FOR THE KINDS OF STUDIES NEEDED TO CONTINUE TO ADVANCE THIS PROMISING FIELD. IN OUR VIEW, THE ROBUST PROTECTION AFFORDED BY THESE ADAPTIVE EPIGENETIC RESPONSES TO CONDITIONING STRESS PROVIDES SIGNIFICANT INCENTIVES FOR BOTH FURTHERING OUR INVESTMENT IN BENCH RESEARCH AND UNDERWRITING CLINICAL TRIALS, SO THAT THE FULL POTENTIAL OF THIS THERAPY CAN BE REALIZED. 2018 2 2611 34 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 3 3404 27 HOW EPIGENETICS IMPACTS ON HUMAN DISEASES. EPIGENETICS IS A RAPIDLY GROWING FIELD OF BIOLOGY THAT STUDIES THE CHANGES IN GENE EXPRESSION THAT ARE NOT DUE TO ALTERATIONS IN THE DNA SEQUENCE BUT RATHER THE CHEMICAL MODIFICATIONS OF DNA AND ITS ASSOCIATED PROTEINS. EPIGENETIC MECHANISMS CAN PROFOUNDLY INFLUENCE GENE EXPRESSION, CELL DIFFERENTIATION, TISSUE DEVELOPMENT, AND DISEASE SUSCEPTIBILITY. UNDERSTANDING EPIGENETIC CHANGES IS ESSENTIAL TO ELUCIDATE THE MECHANISMS UNDERLYING THE INCREASINGLY RECOGNIZED ROLE OF ENVIRONMENTAL AND LIFESTYLE FACTORS IN HEALTH AND DISEASE AND THE INTERGENERATIONAL TRANSMISSION OF PHENOTYPES. RECENT STUDIES SUGGEST EPIGENETICS MAY BE CRITICAL IN VARIOUS DISEASES, FROM CARDIOVASCULAR DISEASE AND CANCER TO NEURODEVELOPMENTAL AND NEURODEGENERATIVE DISORDERS. EPIGENETIC MODIFICATIONS ARE POTENTIALLY REVERSIBLE AND COULD PROVIDE NEW THERAPEUTIC AVENUES FOR TREATING THESE DISEASES USING EPIGENETIC MODULATORS. MOREOVER, EPIGENETICS PROVIDE INSIGHT INTO DISEASE PATHOGENESIS AND BIOMARKERS FOR DISEASE DIAGNOSIS AND RISK STRATIFICATION. NEVERTHELESS, EPIGENETIC INTERVENTIONS HAVE THE POTENTIAL FOR UNINTENDED CONSEQUENCES AND MAY POTENTIALLY LEAD TO INCREASED RISKS OF UNEXPECTED OUTCOMES, SUCH AS ADVERSE DRUG REACTIONS, DEVELOPMENTAL ABNORMALITIES, AND CANCER. THEREFORE, RIGOROUS STUDIES ARE ESSENTIAL TO MINIMIZE THE RISKS ASSOCIATED WITH EPIGENETIC THERAPIES AND TO DEVELOP SAFE AND EFFECTIVE INTERVENTIONS FOR IMPROVING HUMAN HEALTH. THIS ARTICLE PROVIDES A SYNTHETIC AND HISTORICAL VIEW OF THE ORIGIN OF EPIGENETICS AND SOME OF THE MOST RELEVANT ACHIEVEMENTS. 2023 4 806 22 CHALLENGES FOR MODELING AND INTERPRETING THE COMPLEX BIOLOGY OF SEVERE INJURY AND INFLAMMATION. HUMAN INJURY IS ASSOCIATED WITH INFLAMMATORY RESPONSES THAT ARE MODULATED BY THE ACUTE AND CHRONIC ACTIVITY OF ENDOGENOUS FACTORS AND EXOGENOUS INTERVENTIONS. A CHARACTERISTIC FEATURE OF CHRONIC, SEVERE INFLAMMATORY STATES IS THE DIMINISHED SIGNAL OUTPUT VARIABILITY OF MANY ORGAN SYSTEMS, INCLUDING INNATE IMMUNE RESPONSIVENESS AND ENDOGENOUS NEURAL AND ENDOCRINE-MEDIATED FUNCTIONS. THE ATTENUATION OF SIGNAL/RESPONSE VARIABILITY AND INTEGRATION OF FEEDBACK CAPACITY MAY CONTRIBUTE TO SYSTEMIC AND TISSUE-SPECIFIC DETERIORATION OF FUNCTION. SOME WELL-INTENTIONED THERAPIES DIRECTED TOWARD SUPPORT OF SYSTEMIC AND TISSUE FUNCTIONS MAY ACTUALLY PROMOTE THE LOSS OF SYSTEM(S) ADAPTABILITY AND CONTRIBUTE TO ADVERSE OUTCOMES IN SEVERELY STRESSED PATIENTS. IN VIVO AND IN SILICO MODELS OF STRESS, INJURY, AND INFECTION HAVE YET TO FULLY DEFINE THE INFLUENCES OF ONGOING STRESSFUL STIMULAE AS WELL AS GENETIC VARIATION AND EPIGENETIC FACTORS IN THE CONTEXT OF AN EVOLVING INFLAMMATORY STATE. EXPERIMENTAL AND HUMAN MODELS INCORPORATING VARIABLE, ANTECEDENT STRESS(ES) AND ALTERED NEUROENDOCRINE RHYTHMS MIGHT APPROXIMATE THE ALTERED ADAPTABILITY IN IMMUNE AND ORGAN FUNCTION RESPONSES. SUCH MODELS MAY ALSO PROVIDE INSIGHTS INTO THE SALIENT MECHANISMS OF RISK AND OUTCOME MORE PRECISELY THAN DO THE CONSTRAINED STUDY CONDITIONS OF CURRENT ANIMAL OR HUMAN MODELS OF SYSTEMIC INFLAMMATION. 2008 5 2567 38 EPIGENETICS MODIFIERS: POTENTIAL HUB FOR UNDERSTANDING AND TREATING NEURODEVELOPMENTAL DISORDERS FROM HYPOXIC INJURY. BACKGROUND: THE FETAL BRAIN IS ADAPTED TO THE HYPOXIC CONDITIONS PRESENT DURING NORMAL IN UTERO DEVELOPMENT. RELATIVELY MORE HYPOXIC STATES, EITHER CHRONIC OR ACUTE, ARE PATHOLOGIC AND CAN LEAD TO SIGNIFICANT LONG-TERM NEURODEVELOPMENTAL SEQUELAE. IN UTERO HYPOXIC INJURY IS ASSOCIATED WITH NEONATAL MORTALITY AND MILLIONS OF LIVES LIVED WITH VARYING DEGREES OF DISABILITY. MAIN BODY: GENETIC STUDIES OF CHILDREN WITH NEURODEVELOPMENTAL DISEASE INDICATE THAT EPIGENETIC MODIFIERS REGULATING DNA METHYLATION AND HISTONE REMODELING ARE CRITICAL FOR NORMAL BRAIN DEVELOPMENT. EPIGENETIC MODIFIERS ARE ALSO REGULATED BY ENVIRONMENTAL STIMULI, SUCH AS HYPOXIA. INDEED, EPIGENETIC MODIFIERS THAT ARE MUTATED IN CHILDREN WITH GENETIC NEURODEVELOPMENTAL DISEASES ARE REGULATED BY HYPOXIA IN A NUMBER OF PRECLINICAL MODELS AND MAY BE PART OF THE MECHANISM FOR THE LONG-TERM NEURODEVELOPMENTAL SEQUELAE SEEM IN CHILDREN WITH HYPOXIC BRAIN INJURY. THUS, A COMPREHENSIVE UNDERSTANDING THE ROLE OF DNA METHYLATION AND HISTONE MODIFICATIONS IN HYPOXIC INJURY IS CRITICAL FOR DEVELOPING NOVEL STRATEGIES TO TREAT CHILDREN WITH HYPOXIC INJURY. CONCLUSIONS: THIS REVIEW FOCUSES ON OUR CURRENT UNDERSTANDING OF THE INTERSECTION BETWEEN EPIGENETICS, BRAIN DEVELOPMENT, AND HYPOXIA. OPPORTUNITIES FOR THE USE OF EPIGENETICS AS BIOMARKERS OF NEURODEVELOPMENTAL DISEASE AFTER HYPOXIC INJURY AND POTENTIAL CLINICAL EPIGENETICS TARGETS TO IMPROVE OUTCOMES AFTER INJURY ARE ALSO DISCUSSED. WHILE THERE HAVE BEEN MANY PUBLISHED STUDIES ON THE EPIGENETICS OF HYPOXIA, MORE ARE NEEDED IN THE DEVELOPING BRAIN IN ORDER TO DETERMINE WHICH EPIGENETIC PATHWAYS MAY BE MOST IMPORTANT FOR MITIGATING THE LONG-TERM CONSEQUENCES OF HYPOXIC BRAIN INJURY. 2020 6 5926 25 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 7 1204 29 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 8 2526 27 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 9 2703 26 EXERCISE ADAPTATIONS: MOLECULAR MECHANISMS AND POTENTIAL TARGETS FOR THERAPEUTIC BENEFIT. EXERCISE IS FUNDAMENTAL FOR GOOD HEALTH, WHEREAS PHYSICAL INACTIVITY UNDERPINS MANY CHRONIC DISEASES OF MODERN SOCIETY. IT IS WELL APPRECIATED THAT REGULAR EXERCISE IMPROVES METABOLISM AND THE METABOLIC PHENOTYPE IN A NUMBER OF TISSUES. THE PHENOTYPIC ALTERATIONS OBSERVED IN SKELETAL MUSCLE ARE PARTLY MEDIATED BY TRANSCRIPTIONAL RESPONSES THAT OCCUR FOLLOWING EACH INDIVIDUAL BOUT OF EXERCISE. THIS ADAPTIVE RESPONSE INCREASES OXIDATIVE CAPACITY AND INFLUENCES THE FUNCTION OF MYOKINES AND EXTRACELLULAR VESICLES THAT SIGNAL TO OTHER TISSUES. OUR UNDERSTANDING OF THE EPIGENETIC AND TRANSCRIPTIONAL MECHANISMS THAT MEDIATE THE SKELETAL MUSCLE GENE EXPRESSION RESPONSE TO EXERCISE AS WELL AS OF THEIR UPSTREAM SIGNALLING PATHWAYS HAS ADVANCED SUBSTANTIALLY IN THE PAST 10 YEARS. WITH THIS KNOWLEDGE ALSO COMES THE OPPORTUNITY TO DESIGN NEW THERAPEUTIC STRATEGIES BASED ON THE BIOLOGY OF EXERCISE FOR A VARIETY OF CHRONIC CONDITIONS WHERE REGULAR EXERCISE MIGHT BE A CHALLENGE. THIS REVIEW PROVIDES AN OVERVIEW OF THE BENEFICIAL ADAPTIVE RESPONSES TO EXERCISE AND DETAILS THE MOLECULAR MECHANISMS INVOLVED. THE POSSIBILITY OF DESIGNING THERAPEUTIC INTERVENTIONS BASED ON THESE MOLECULAR MECHANISMS IS ADDRESSED, USING RELEVANT EXAMPLES THAT HAVE EXPLOITED THIS APPROACH. 2020 10 6447 26 THERAPEUTIC PROSPECTS FOR EPIGENETIC MODULATION. INTRODUCTION: EPIGENETICS DESCRIBES THE PHENOMENON OF HERITABLE CHANGES IN GENE REGULATION GOVERNED BY NON-MENDELIAN PROCESSES, PRIMARILY THROUGH BIOCHEMICAL MODIFICATIONS TO CHROMATIN THAT OCCUR DURING CELL DIFFERENTIATION AND DEVELOPMENT. ABNORMAL LEVELS OF DNA AND/OR HISTONE MODIFICATIONS ARE OBSERVED IN PATIENTS WITH A WIDE VARIETY OF CHRONIC DISEASES. DRUGS THAT TARGET THE PROTEINS CONTROLLING THESE CHROMATIN MODIFICATIONS CAN MODULATE THE EXPRESSION OF CLUSTERS OF GENES, POTENTIALLY OFFERING HIGHER THERAPEUTIC EFFICACY THAN CLASSICAL AGENTS WITH SINGLE TARGET PHARMACOLOGIES THAT ARE SUSCEPTIBLE TO BIOCHEMICAL PATHWAY DEGENERACY. AREAS COVERED: THIS ARTICLE REVIEWS RESEARCH CHARACTERIZING DYSREGULATION OF EPIGENETIC PROCESSES IN CANCER, IMMUNO-INFLAMMATORY, PSYCHIATRIC, NEUROLOGICAL, METABOLIC AND VIROLOGY DISEASE AREAS, AND SUMMARIZES RECENT DEVELOPMENTS IN IDENTIFYING SMALL MOLECULE MODULATORS THAT ARE BEING USED TO INFORM TARGET DISCOVERY AND INITIATE DRUG DISCOVERY PROJECTS. EXPERT OPINION: THERE ARE NUMEROUS POTENTIAL OPPORTUNITIES FOR EPIGENETIC MODULATORS IN TREATING A WIDE RANGE OF CHRONIC DISEASES; HOWEVER, THE FIELD IS COMPLEX, INVOLVING > 300 PROTEINS, AND MUCH WORK IS STILL REQUIRED TO PROVIDE TOOLS TO UNRAVEL THE FUNCTIONS OF INDIVIDUAL PROTEINS, PARTICULARLY IN VIVO. THIS GROUNDWORK IS ESSENTIAL TO ALLOW THE DRUG DISCOVERY COMMUNITY TO FOCUS ON THOSE EPIGENETIC PROTEINS MOST LIKELY TO BE SUITABLE TARGETS FOR SAFE, EFFICACIOUS NEW THERAPIES. 2011 11 2523 33 EPIGENETICS AND THE TRANSITION FROM ACUTE TO CHRONIC PAIN. OBJECTIVE: THE OBJECTIVE OF THIS STUDY WAS TO REVIEW THE EPIGENETIC MODIFICATIONS INVOLVED IN THE TRANSITION FROM ACUTE TO CHRONIC PAIN AND TO IDENTIFY POTENTIAL TARGETS FOR THE DEVELOPMENT OF NOVEL, INDIVIDUALIZED PAIN THERAPEUTICS. BACKGROUND: EPIGENETICS IS THE STUDY OF HERITABLE MODIFICATIONS IN GENE EXPRESSION AND PHENOTYPE THAT DO NOT REQUIRE A CHANGE IN GENETIC SEQUENCE TO MANIFEST THEIR EFFECTS. ENVIRONMENTAL TOXINS, MEDICATIONS, DIET, AND PSYCHOLOGICAL STRESSES CAN ALTER EPIGENETIC PROCESSES SUCH AS DNA METHYLATION, HISTONE ACETYLATION, AND RNA INTERFERENCE. AS EPIGENETIC MODIFICATIONS POTENTIALLY PLAY AN IMPORTANT ROLE IN INFLAMMATORY CYTOKINE METABOLISM, STEROID RESPONSIVENESS, AND OPIOID SENSITIVITY, THEY ARE LIKELY KEY FACTORS IN THE DEVELOPMENT OF CHRONIC PAIN. ALTHOUGH OUR KNOWLEDGE OF THE HUMAN GENETIC CODE AND DISEASE-ASSOCIATED POLYMORPHISMS HAS GROWN SIGNIFICANTLY IN THE PAST DECADE, WE HAVE NOT YET BEEN ABLE TO ELUCIDATE THE MECHANISMS THAT LEAD TO THE DEVELOPMENT OF PERSISTENT PAIN AFTER NERVE INJURY OR SURGERY. DESIGN: THIS IS A FOCUSED LITERATURE REVIEW OF EPIGENETIC SCIENCE AND ITS RELATIONSHIP TO CHRONIC PAIN. RESULTS: SIGNIFICANT LABORATORY AND CLINICAL DATA SUPPORT THE NOTION THAT EPIGENETIC MODIFICATIONS ARE AFFECTED BY THE ENVIRONMENT AND LEAD TO DIFFERENTIAL GENE EXPRESSION. SIMILAR TO MECHANISMS INVOLVED IN THE DEVELOPMENT OF CANCER, NEURODEGENERATIVE DISEASE, AND INFLAMMATORY DISORDERS, THE LITERATURE ENDORSES AN IMPORTANT POTENTIAL ROLE FOR EPIGENETICS IN CHRONIC PAIN. CONCLUSIONS: EPIGENETIC ANALYSIS MAY IDENTIFY MECHANISMS CRITICAL TO THE DEVELOPMENT OF CHRONIC PAIN AFTER INJURY, AND MAY PROVIDE NEW PATHWAYS AND TARGET MECHANISMS FOR FUTURE DRUG DEVELOPMENT AND INDIVIDUALIZED MEDICINE. 2012 12 2333 21 EPIGENETIC REGULATION OF INFLAMMATION: THE METABOLOMICS CONNECTION. EPIGENETIC FACTORS ARE CONSIDERED THE REGULATOR OF COMPLEX MACHINERY BEHIND INFLAMMATORY DISORDERS AND SIGNIFICANTLY CONTRIBUTED TO THE EXPRESSION OF INFLAMMATION-ASSOCIATED GENES. EPIGENETIC MODIFICATIONS MODULATE VARIATION IN THE EXPRESSION PATTERN OF TARGET GENES WITHOUT AFFECTING THE DNA SEQUENCE. THE CURRENT KNOWLEDGE OF EPIGENETIC RESEARCH FOCUSED ON THEIR ROLE IN THE PATHOGENESIS OF VARIOUS INFLAMMATORY DISEASES THAT CAUSES MORBIDITY AND MORTALITY WORLDWIDE. INFLAMMATORY DISEASES ARE CATEGORIZED AS ACUTE AND CHRONIC BASED ON THE DISEASE SEVERITY AND ARE REGULATED BY THE EXPRESSION PATTERN OF VARIOUS GENES. HENCE, UNDERSTANDING THE ROLE OF EPIGENETIC MODIFICATIONS DURING INFLAMMATION PROGRESSION WILL CONTRIBUTE TO THE DISEASE OUTCOMES AND THERAPEUTIC APPROACHES. THIS REVIEW ALSO FOCUSES ON THE METABOLOMICS APPROACH ASSOCIATED WITH THE STUDY OF INFLAMMATORY DISORDERS. INFLAMMATORY RESPONSES AND METABOLIC REGULATION ARE HIGHLY INTEGRATED AND VARIOUS ADVANCED TECHNIQUES ARE ADOPTED TO STUDY THE METABOLIC SIGNATURE MOLECULES. HERE WE DISCUSS SEVERAL METABOLOMICS APPROACHES USED TO LINK INFLAMMATORY DISORDERS AND EPIGENETIC CHANGES. WE PROPOSED THAT DECIPHERING THE MECHANISM BEHIND THE INFLAMMATION-METABOLISM LOOP MAY HAVE IMMENSE IMPORTANCE IN BIOMARKERS RESEARCH AND MAY ACT AS A PRINCIPAL COMPONENT IN DRUG DISCOVERY AS WELL AS THERAPEUTIC APPLICATIONS. 2022 13 6807 17 [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 6866 26 [PAIN AND EMOTIONAL DYSREGULATION: CELLULAR MEMORY DUE TO PAIN]. GENETIC FACTORS ARE INVOLVED IN DETERMINANTS FOR THE RISK OF PSYCHIATRIC DISORDERS, AND NEUROLOGICAL AND NEURODEGENERATIVE DISEASES. CHRONIC PAIN STIMULI AND INTENSE PAIN HAVE EFFECTS AT A CELLULAR AND/OR GENE EXPRESSION LEVEL, AND WILL EVENTUALLY INDUCE "CELLULAR MEMORY DUE TO PAIN", WHICH MEANS THAT TISSUE DAMAGE, EVEN IF ONLY TRANSIENT, CAN ELICIT EPIGENETICALLY ABNORMAL TRANSCRIPTION/TRANSLATION AND POST-TRANSLATIONAL MODIFICATION IN RELATED CELLS DEPENDING ON THE DEGREE OR KIND OF INJURY OR ASSOCIATED CONDITIONS. SUCH CELL MEMORY/TRANSFORMATION DUE TO PAIN CAN CAUSE AN ABNORMALITY IN A FUNDAMENTAL INTRACELLULAR RESPONSE, SUCH AS A CHANGE IN THE THREE-DIMENSIONAL STRUCTURE OF DNA, TRANSCRIPTION, OR TRANSLATION. ON THE OTHER HAND, PAIN IS A MULTIDIMENSIONAL EXPERIENCE WITH SENSORY-DISCRIMINATIVE AND MOTIVATIONAL-AFFECTIVE COMPONENTS. RECENT HUMAN BRAIN IMAGING STUDIES HAVE EXAMINED DIFFERENCES IN ACTIVITY IN THE NUCLEUS ACCUMBENS BETWEEN CONTROLS AND PATIENTS WITH CHRONIC PAIN, AND HAVE REVEALED THAT THE NUCLEUS ACCUMBENS PLAYS A ROLE IN PREDICTING THE VALUE OF A NOXIOUS STIMULUS AND ITS OFFSET, AND IN THE CONSEQUENT CHANGES IN THE MOTIVATIONAL STATE. IN THIS REVIEW, WE PROVIDE A VERY BRIEF OVERVIEW OF A COMPREHENSIVE UNDERSTANDING OF CHRONIC PAIN ASSOCIATED WITH EMOTIONAL DYSREGULATION DUE TO TRANSCRIPTIONAL REGULATION, EPIGENETIC MODIFICATION AND MIRNA REGULATION. 2015 15 4325 33 MICRORNAS IN THE EVALUATION AND POTENTIAL TREATMENT OF LIVER DISEASES. ACUTE AND CHRONIC LIVER DISEASE CONTINUE TO RESULT IN SIGNIFICANT MORBIDITY AND MORTALITY OF PATIENTS, ALONG WITH INCREASING BURDEN ON THEIR FAMILIES, SOCIETY AND THE HEALTH CARE SYSTEM. THIS IN PART IS DUE TO INCREASED INCIDENCE OF LIVER DISEASE ASSOCIATED FACTORS SUCH AS METABOLIC SYNDROME; IMPROVED SURVIVAL OF PATIENTS WITH CHRONIC PREDISPOSING CONDITIONS SUCH AS HIV; AS WELL AS ADVANCES IN THE FIELD OF TRANSPLANTATION AND ASSOCIATED CARE LEADING TO IMPROVED SURVIVAL. THE FACT THAT ONE DISEASE CAN RESULT IN DIFFERENT MANIFESTATIONS AND OUTCOMES HIGHLIGHTS THE NEED FOR IMPROVED UNDERSTANDING OF NOT JUST GENETIC PHENOMENON PREDISPOSING TO A CONDITION, BUT ADDITIONALLY THE ROLE OF EPIGENETIC AND ENVIRONMENTAL FACTORS LEADING TO THE PHENOTYPE OF THE DISEASE. IT IS NOT SURPRISING THAT PROVIDERS CONTINUE TO FACE DAILY CHALLENGES PERTAINING TO DIAGNOSTIC ACCURACY, PROGNOSTICATION OF DISEASE SEVERITY, PROGRESSION, AND RESPONSE TO THERAPIES. A NUMBER OF THESE CHALLENGES CAN BE ADDRESSED BY INCORPORATING A PERSONALIZED APPROACH OF MANAGEMENT TO THE CURRENT PARADIGM OF CARE. RECENT ADVANCES IN THE FIELDS OF MOLECULAR BIOLOGY AND GENETICS HAVE PAVED THE WAY TO MORE ACCURATE, INDIVIDUALIZED AND PRECISE APPROACH TO CARING FOR LIVER DISEASE. THE STUDY OF MICRORNAS AND THEIR ROLE IN BOTH HEALTHY AND DISEASED LIVERS IS ONE EXAMPLE OF SUCH ADVANCES. AS THESE SMALL, NON-CODING RNAS WORK ON FINE-TUNING OF CELLULAR ACTIVITIES AND ORGAN FUNCTION IN A DYNAMIC AND PRECISE FASHION, THEY PROVIDE US A GOLDEN OPPORTUNITY TO ADVANCE THE FIELD OF HEPATOLOGY. THE STUDY OF MICRORNAS IN LIVER DISEASE PROMISES TREMENDOUS IMPROVEMENT IN HEPATOLOGY AND IS LIKELY TO LAY THE FOUNDATION TOWARDS A PERSONALIZED APPROACH IN LIVER DISEASE. 2016 16 6414 26 THE STRESSED SYNAPSE 2.0: PATHOPHYSIOLOGICAL MECHANISMS IN STRESS-RELATED NEUROPSYCHIATRIC DISORDERS. STRESS IS A PRIMARY RISK FACTOR FOR SEVERAL NEUROPSYCHIATRIC DISORDERS. EVIDENCE FROM PRECLINICAL MODELS AND CLINICAL STUDIES OF DEPRESSION HAVE REVEALED AN ARRAY OF STRUCTURAL AND FUNCTIONAL MALADAPTIVE CHANGES, WHEREBY ADVERSE ENVIRONMENTAL FACTORS SHAPE THE BRAIN. THESE CHANGES, OBSERVED FROM THE MOLECULAR AND TRANSCRIPTIONAL LEVELS THROUGH TO LARGE-SCALE BRAIN NETWORKS, TO THE BEHAVIOURS REVEAL A COMPLEX MATRIX OF INTERRELATED PATHOPHYSIOLOGICAL PROCESSES THAT DIFFER BETWEEN SEXES, PROVIDING INSIGHT INTO THE POTENTIAL UNDERPINNINGS OF THE SEX BIAS OF NEUROPSYCHIATRIC DISORDERS. ALTHOUGH MANY PRECLINICAL STUDIES USE CHRONIC STRESS PROTOCOLS, LONG-TERM CHANGES ARE ALSO INDUCED BY ACUTE EXPOSURE TO TRAUMATIC STRESS, OPENING A PATH TO IDENTIFY DETERMINANTS OF RESILIENT VERSUS SUSCEPTIBLE RESPONSES TO BOTH ACUTE AND CHRONIC STRESS. EPIGENETIC REGULATION OF GENE EXPRESSION HAS EMERGED AS A KEY PLAYER UNDERLYING THE PERSISTENT IMPACT OF STRESS ON THE BRAIN. INDEED, HISTONE MODIFICATION, DNA METHYLATION AND MICRORNAS ARE CLOSELY INVOLVED IN MANY ASPECTS OF THE STRESS RESPONSE AND REVEAL THE GLUTAMATE SYSTEM AS A KEY PLAYER. THE SUCCESS OF KETAMINE HAS STIMULATED A WHOLE LINE OF RESEARCH AND DEVELOPMENT ON DRUGS DIRECTLY OR INDIRECTLY TARGETING GLUTAMATE FUNCTION. HOWEVER, THE CHALLENGE OF TRANSLATING THE EMERGING UNDERSTANDING OF STRESS PATHOPHYSIOLOGY INTO EFFECTIVE CLINICAL TREATMENTS REMAINS A MAJOR CHALLENGE. 2022 17 2562 22 EPIGENETICS IN THE PRIMARY AND SECONDARY PREVENTION OF CARDIOVASCULAR DISEASE: INFLUENCE OF EXERCISE AND NUTRITION. INCREASING EVIDENCE LINKS CHANGES IN EPIGENETIC SYSTEMS, SUCH AS DNA METHYLATION, HISTONE MODIFICATION, AND NON-CODING RNA EXPRESSION, TO THE OCCURRENCE OF CARDIOVASCULAR DISEASE (CVD). THESE EPIGENETIC MODIFICATIONS CAN CHANGE GENETIC FUNCTION UNDER INFLUENCE OF EXOGENOUS STIMULI AND CAN BE TRANSFERRED TO NEXT GENERATIONS, PROVIDING A POTENTIAL MECHANISM FOR INHERITANCE OF BEHAVIOURAL INTERVENTION EFFECTS. THE BENEFITS OF EXERCISE AND NUTRITIONAL INTERVENTIONS IN THE PRIMARY AND SECONDARY PREVENTION OF CVD ARE WELL ESTABLISHED, BUT THE MECHANISMS ARE NOT COMPLETELY UNDERSTOOD. IN THIS REVIEW, WE DESCRIBE THE ACUTE AND CHRONIC EPIGENETIC EFFECTS OF PHYSICAL ACTIVITY AND DIETARY CHANGES. WE PROPOSE EXERCISE AND NUTRITION AS POTENTIAL TRIGGERS OF EPIGENETIC SIGNALS, PROMOTING THE RESHAPING OF TRANSCRIPTIONAL PROGRAMMES WITH EFFECTS ON CVD PHENOTYPES. FINALLY, WE HIGHLIGHT RECENT DEVELOPMENTS IN EPIGENETIC THERAPEUTICS WITH IMPLICATIONS FOR PRIMARY AND SECONDARY CVD PREVENTION. 2022 18 2154 27 EPIGENETIC MECHANISMS AND KIDNEY DISEASES. IN RECENT YEARS, MOLECULAR RESEARCH HAS BROUGHT TO LIGHT A SERIES OF MECHANISMS INVOLVED IN THE REGULATION OF GENE FUNCTION WITHOUT ALTERING THE DNA SEQUENCE. THESE MECHANISMS ARE DESCRIBED WITH THE TERM "EPIGENETICS" AND INCLUDE MODIFICATIONS IN THE STRUCTURE OF THE HUMAN GENOME, LEADING TO HERITABLE AND POTENTIALLY REVERSIBLE CHANGES IN GENE EXPRESSION. THERE IS NOW INCREASING EVIDENCE SUGGESTING THAT SEVERAL CHARACTERISTIC FEATURES OF CHRONIC KIDNEY DISEASE SUCH AS HYPERHOMOCYSTEINEMIA, SUBCLINICAL INFLAMMATION, INCREASED OXIDATIVE STRESS AND OTHERS MAY AFFECT THE HUMAN EPIGENOME. IN ADDITION, ANIMAL STUDIES HAVE SUGGESTED A POSSIBLE LINK BETWEEN NUTRITION AND ENVIRONMENTAL EXPOSURE DURING THE PERICONCEPTIONAL PERIOD AND EPIGENETIC CHANGES IN THE EXPRESSION OF MAJOR GENES IMPLICATED IN KIDNEY ORGANOGENESIS; THESE CHANGES RESULT IN A DIMINISHED NUMBER OF NEPHRONS IN THE DEVELOPING KIDNEY, WHICH PREDISPOSES TO AN INCREASED RISK FOR HYPERTENSION AND CHRONIC KIDNEY DISEASE IN FUTURE LIFE. THE UNDERSTANDING OF THE ROLE OF EPIGENETIC PHENOMENA IN THE PATHOGENESIS OF CHRONIC KIDNEY DISEASE OPENS NEW AVENUES FOR FUTURE THERAPEUTIC STRATEGIES, THROUGH THE DEVELOPMENT OF PHARMACEUTICAL AGENTS THAT TARGET DIRECTLY WITH THE CHANGES IN THE HUMAN EPIGENOME. SUCH EPIGENETIC DRUGS ARE ALREADY IN CLINICAL USE FOR THE TREATMENT OF CANCER AS WELL AS UNDER INVESTIGATION FOR THE USE IN OTHER DISEASES. THIS REVIEW WILL SUMMARIZE THE EXISTING DATA ON THE LINK BETWEEN EPIGENETIC MECHANISMS AND CHRONIC UREMIC MILIEU, AS WELL AS THE PROMISING RESULTS OF ONGOING RESEARCH IN THE FIELD OF EPIGENETIC DRUGS THAT COULD REPRESENT ADDITIONAL OPTIONS IN OUR THERAPEUTIC ARMAMENTARIUM FOR PATIENTS WITH CHRONIC KIDNEY DISEASE. 2011 19 4382 26 MITOCHONDRIAL EPIGENETICS AND ENVIRONMENTAL EXPOSURE. THE RISING TOLL OF CHRONIC AND DEBILITATING DISEASES BROUGHT ABOUT BY THE EXPOSURE TO AN EVER EXPANDING NUMBER OF ENVIRONMENTAL POLLUTANTS AND SOCIO-ECONOMIC FACTORS IS CALLING FOR ACTION. THE UNDERSTANDING OF THE MOLECULAR MECHANISMS BEHIND THE EFFECTS OF ENVIRONMENTAL EXPOSURES CAN LEAD TO THE DEVELOPMENT OF BIOMARKERS THAT CAN SUPPORT THE PUBLIC HEALTH FIELDS OF BOTH EARLY DIAGNOSIS AND INTERVENTION TO LIMIT THE BURDEN OF ENVIRONMENTAL DISEASES. THE STUDY OF MITOCHONDRIAL EPIGENETICS CARRIES HIGH HOPES TO PROVIDE IMPORTANT BIOMARKERS OF EXPOSURE AND DISEASE. MITOCHONDRIA ARE IN FACT ON THE FRONTLINE OF THE CELLULAR RESPONSE TO THE ENVIRONMENT. MODIFICATIONS OF THE EPIGENETIC FACTORS REGULATING THE MITOCHONDRIAL ACTIVITY ARE EMERGING AS INFORMATIVE TOOLS THAT CAN EFFECTIVELY REPORT ON THE EFFECTS OF THE ENVIRONMENT ON THE PHENOTYPE. HERE, WE WILL DISCUSS THE EMERGING FIELD OF MITOCHONDRIAL EPIGENETICS. THIS REVIEW DESCRIBES THE MAIN EPIGENETIC PHENOMENA THAT MODIFY THE ACTIVITY OF THE MITOCHONDRIAL DNA INCLUDING DNA METHYLATION, LONG AND SHORT NON-CODING RNAS. WE WILL DISCUSS THE UNIQUE PATTERN OF MITOCHONDRIAL DNA METHYLATION, DESCRIBE THE CHALLENGES OF CORRECTLY MEASURING IT, AND REPORT ON THE EXISTING STUDIES THAT HAVE ANALYSED THE CORRELATION BETWEEN ENVIRONMENTAL EXPOSURES AND MITOCHONDRIAL DNA METHYLATION. FINALLY, WE PROVIDE A BRIEF ACCOUNT OF THE THERAPEUTIC APPROACHES TARGETING MITOCHONDRIA CURRENTLY UNDER CONSIDERATION. 2016 20 2586 32 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