1 5129 137 POSTOPERATIVE PAIN AND ANALGESIA: IS THERE A GENETIC BASIS TO THE OPIOID CRISIS? BACKGROUND: MULTIPLE FACTORS HAVE BEEN IMPLICATED IN DETERMINING WHY CERTAIN PATIENTS HAVE INCREASED POSTOPERATIVE PAIN, WITH THE POTENTIAL TO DEVELOP CHRONIC PAIN. THE PURPOSE OF THIS STUDY WAS TO: 1) IDENTIFY AND DESCRIBE GENES THAT AFFECT POSTOPERATIVE PAIN PERCEPTION AND CONTROL; 2) ADDRESS MODIFIABLE RISK FACTORS THAT RESULT IN EPIGENETIC ALTERED RESPONSES TO PAIN; AND 3) CHARACTERIZE DIFFERENCES IN PAIN SENSITIVITY AND THRESHOLDS BETWEEN OPIOID-NAIVE AND OPIOID-DEPENDENT PATIENTS. MATERIALS AND METHODS: THREE ELECTRONIC DATABASES WERE USED TO CONDUCT THE LITERATURE SEARCH: PUBMED, EBSCO HOST, AND SCOPUS. A TOTAL OF 372 ABSTRACTS WERE REVIEWED, OF WHICH 46 STUDIES WERE DEEMED RELEVANT AND ARE INCLUDED IN THIS REVIEW. RESULTS: SPECIFIC GENE ALTERATIONS THAT WERE SHOWN TO AFFECT POSTOPERATIVE PAIN CONTROL INCLUDED SINGLE NUCLEOTIDE POLYMORPHISMS IN THE MU, KAPPA, AND DELTA OPIOID RECEPTORS, ION CHANNEL GENES, CYTOTOXIC T-CELLS, GLUTAMATE RECEPTORS AND CYTOKINE GENES, AMONG OTHERS. ALCOHOLISM, OBESITY, AND SMOKING WERE ALL LINKED WITH GENETIC POLYMORPHISMS THAT ALTERED PAIN SENSITIVITY. OPIOID ABUSE WAS FOUND TO BE ASSOCIATED WITH A POORER RESPONSE TO ANALGESICS POSTOPERATIVELY, AS WELL AS A RISK FOR PRESCRIPTION OVERDOSE. CONCLUSION: ALTHOUGH PAIN PERCEPTION HAS MULTIPLE COMPLEX INFLUENCES, THE GREATEST VARIABILITY SEEN IN RESPONSE TO OPIOIDS AMONG POSTOPERATIVE PATIENTS KNOWN TO DATE CAN BE TRACED TO GENETIC DIFFERENCES IN OPIOID METABOLISM. FURTHER STUDY IS NEEDED TO DETERMINE THE CLINICAL SIGNIFICANCE OF THESE GENETIC ASSOCIATIONS. 2018 2 4915 46 PAIN, ANALGESIA AND GENETICS. OBJECTIVES: IN THE CLINICAL SETTING, THERE IS MARKED INTERSUBJECT VARIABILITY IN THE INTENSITY OF PAIN REPORTED BY PATIENTS WITH APPARENTLY SIMILAR PAIN STATES, AS WELL AS WIDELY DIFFERING ANALGESIC DOSING REQUIREMENTS BETWEEN INDIVIDUALS TO PRODUCE SATISFACTORY PAIN RELIEF WITH TOLERABLE SIDE-EFFECTS. GENETIC AND ENVIRONMENTAL FACTORS AS WELL AS THEIR INTERACTION ARE IMPLICATED, AND THESE ARE DISCUSSED IN THIS REVIEW. KEY FINDINGS: PIONEERING WORK UNDERTAKEN IN MICE MORE THAN A DECADE AGO, SHOWED A STRONG GENETIC CONTRIBUTION TO LEVELS OF NOCICEPTION/HYPERSENSITIVITY AS WELL AS LEVELS OF ANTINOCICEPTION PRODUCED BY COMMONLY AVAILABLE ANALGESIC AGENTS. TO DATE MORE THAN 300 CANDIDATE 'PAIN' GENES HAVE BEEN IDENTIFIED AS POTENTIALLY CONTRIBUTING TO HERITABLE DIFFERENCES IN PAIN SENSITIVITY AND ANALGESIC RESPONSIVENESS IN ANIMALS AND HUMANS, WITH THIS INFORMATION AVAILABLE IN A PUBLICLY ACCESSIBLE DATABASE HTTP://WWW.JBLDESIGN.COM/JMOGIL/ENTER.HTML. SINCE THEN, MANY GENETIC ASSOCIATION STUDIES HAVE BEEN CONDUCTED IN HUMANS TO INVESTIGATE THE POSSIBILITY THAT SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) IN AN INDIVIDUAL GENE MAY EXPLAIN DRUG INEFFICACY OR EXCESSIVE TOXICITY EXPERIENCED BY A SMALL SUBSET OF THE WHOLE POPULATION WHO HAVE THE RARE ALLELE FOR A PARTICULAR SNP. SUMMARY: DESPITE THE FACT THAT SNPS IN MORE THAN 20 GENES THAT AFFECT PAIN SENSITIVITY OR CONTRIBUTE TO INTERINDIVIDUAL VARIABILITY IN RESPONSES TO ANALGESIC MEDICATIONS HAVE BEEN IDENTIFIED IN THE HUMAN GENOME, MUCH OF THE DATA IS CONFLICTING. APART FROM DEFICIENCIES IN THE DESIGN AND CONDUCT OF HUMAN GENETIC ASSOCIATION STUDIES, RECENT RESEARCH FROM OTHER FIELDS HAS IMPLICATED EPIGENETIC MECHANISMS THAT FACILITATE DYNAMIC GENE-ENVIRONMENT COMMUNICATION, AS A POSSIBLE EXPLANATION. 2011 3 5040 35 PHARMACOGENETICS OF PAIN AND ANALGESIA. PAIN SEVERITY RATINGS AND THE ANALGESIC DOSING REQUIREMENTS OF PATIENTS WITH APPARENTLY SIMILAR PAIN CONDITIONS MAY DIFFER CONSIDERABLY BETWEEN INDIVIDUALS. CONTRIBUTING FACTORS INCLUDE THOSE OF GENETIC AND ENVIRONMENTAL ORIGIN WITH EPIGENETIC MECHANISMS THAT ENABLE DYNAMIC GENE-ENVIRONMENT INTERACTION, MORE RECENTLY IMPLICATED IN PAIN MODULATION. INSIGHT INTO GENETIC FACTORS UNDERPINNING INTER-PATIENT VARIABILITY IN PAIN SENSITIVITY HAS COME FROM RODENT HERITABILITY STUDIES AS WELL AS FAMILIAL AGGREGATION AND TWIN STUDIES IN HUMANS. INDEED, MORE THAN 350 CANDIDATE PAIN GENES HAVE BEEN IDENTIFIED AS POTENTIALLY CONTRIBUTING TO HERITABLE DIFFERENCES IN PAIN SENSITIVITY. A LARGE NUMBER OF GENETIC ASSOCIATION STUDIES CONDUCTED IN PATIENTS WITH A VARIETY OF CLINICAL PAIN TYPES OR IN HUMANS EXPOSED TO EXPERIMENTALLY INDUCED PAIN STIMULI IN THE LABORATORY SETTING, HAVE EXAMINED THE IMPACT OF SINGLE-NUCLEOTIDE POLYMORPHISMS IN VARIOUS TARGET GENES ON PAIN SENSITIVITY AND/OR ANALGESIC DOSING REQUIREMENTS. HOWEVER, THE FINDINGS OF SUCH STUDIES HAVE GENERALLY FAILED TO REPLICATE OR HAVE BEEN ONLY PARTIALLY REPLICATED BY INDEPENDENT INVESTIGATORS. DEFICIENCIES IN STUDY CONDUCT INCLUDING USE OF SMALL SAMPLE SIZE, INAPPROPRIATE STATISTICAL METHODS AND INADEQUATE ATTENTION TO THE POSSIBILITY THAT BETWEEN-STUDY DIFFERENCES IN ENVIRONMENTAL FACTORS MAY ALTER PAIN PHENOTYPES THROUGH EPIGENETIC MECHANISMS, HAVE BEEN IDENTIFIED AS BEING SIGNIFICANT. 2012 4 6458 39 TIME COURSE OF DNA METHYLATION IN PAIN CONDITIONS: FROM EXPERIMENTAL MODELS TO HUMANS. BACKGROUND AND OBJECTIVE: THROUGHOUT THE LAST DECADE, RESEARCH HAS UNCOVERED ASSOCIATIONS BETWEEN PAIN AND EPIGENETIC ALTERATIONS CAUSED BY ENVIRONMENTAL FACTORS. SPECIFICALLY, STUDIES HAVE DEMONSTRATED CORRELATIONS BETWEEN PAIN CONDITIONS AND ALTERED DNA METHYLATION PATTERNS. THUS, DNA METHYLATION HAS BEEN REVEALED AS A POSSIBLE MODULATOR OR CONTRIBUTOR TO PAIN CONDITIONS, PROVIDING A POTENTIAL THERAPEUTIC TARGET FOR TREATMENT BY DNA METHYLATION MODIFICATION. TO DEVELOP SUCH TREATMENTS, IT IS NECESSARY TO CLARIFY A WIDE NUMBER OF ASPECTS ON HOW DNA METHYLATION AFFECTS PAIN PERCEPTION; FIRST AND FOREMOST, THE TEMPORAL DYNAMICS. THE OBJECTIVE OF THE PRESENT REVIEW IS TO PROVIDE AN OVERVIEW OF CURRENT KNOWLEDGE ON TEMPORAL DYNAMICS OF DNA METHYLATION IN RESPONSE TO PAIN, AND TO INVESTIGATE IF A TIMEFRAME CAN BE ESTABLISHED BASED ON THE DATA OF CURRENTLY PUBLISHED STUDIES. DATABASES AND DATA TREATMENT: PUBMED, MEDLINE, GOOGLE SCHOLAR AND EMBASE WERE SEARCHED COMPREHENSIVELY FOR STUDIES OF DNA METHYLATION IN NEUROPATHIC, INFLAMMATORY AND ALTERNATIVE ANIMAL PAIN MODELS, AND IN CHRONIC PAIN PATIENTS INCLUDING COMPLEX REGIONAL PAIN SYNDROME, CHRONIC POSTSURGICAL PAIN, CHRONIC WIDESPREAD PAIN, FIBROMYALGIA AND CROHN'S DISEASE. RESULTS: WE IDENTIFIED 34 ARTICLES HIGHLIGHTING VARIATIONS IN TEMPORAL DYNAMICS OF DNA METHYLATION ACROSS SPECIES AND BETWEEN DIFFERENT TYPES OF PAIN. THESE STUDIES REPRESENT A STARTING POINT TO UNCOVER NEW INSIGHTS IN THE DNA METHYLATION TIME COURSE IN PAIN. CONCLUSIONS: NO TIMEFRAME CAN CURRENTLY BE MADE FOR THE DNA METHYLATION RESPONSE TO PAIN IN ANY OF THE REVIEWED CONDITIONS, HIGHLIGHTING AN IMPORTANT FOCUS AREA FOR FUTURE RESEARCH. 2021 5 976 36 CHRONIC OPIOID USE IS ASSOCIATED WITH INCREASED DNA METHYLATION CORRELATING WITH INCREASED CLINICAL PAIN. ENVIRONMENTALLY CAUSED CHANGES IN CHROMOSOMES THAT DO NOT ALTER THE DNA SEQUENCE BUT CAUSE PHENOTYPIC CHANGES BY ALTERING GENE TRANSCRIPTION ARE SUMMARIZED AS EPIGENETICS. A MAJOR EPIGENETIC MECHANISM IS METHYLATION OR DEMETHYLATION AT CPG-RICH DNA ISLANDS. DNA METHYLATION TRIGGERED BY DRUGS HAS LARGELY UNEXPLORED THERAPEUTIC CONSEQUENCES. HERE WE REPORT INCREASED METHYLATION AT A CPG RICH ISLAND IN THE OPRM1 GENE CODING FOR MU-OPIOID RECEPTORS AND AT A GLOBAL METHYLATION SITE (LINE-1) IN LEUKOCYTES OF METHADONE-SUBSTITUTED FORMER OPIATE ADDICTS COMPARED WITH MATCHED HEALTHY CONTROLS. HIGHER DNA METHYLATION ASSOCIATED WITH CHRONIC OPIOID EXPOSURE WAS REPRODUCED IN AN INDEPENDENT COHORT OF OPIOID-TREATED AS COMPARED TO NON-OPIOID-TREATED PAIN PATIENTS. THIS SUGGESTS THAT OPIOIDS MAY STIMULATE DNA METHYLATION. THE OPRM1 METHYLATION HAD NO IMMEDIATE EFFECT ON MU-OPIOID RECEPTOR TRANSCRIPTION AND WAS NOT ASSOCIATED WITH OPIOID DOSING REQUIREMENTS. HOWEVER, THE GLOBAL DNA METHYLATION AT LINE-1 WAS SIGNIFICANTLY CORRELATED WITH INCREASED CHRONIC PAIN. THIS SUGGESTS INHIBITORY EFFECTS ON THE TRANSCRIPTION OF STILL UNSPECIFIED NOCIFENSIVE GENE PRODUCTS. IT FURTHER IMPLIES THAT OPIOIDS MAY BE CAUSALLY ASSOCIATED WITH INCREASED GENOME-WIDE DNA METHYLATION, ALTHOUGH CURRENTLY THERE IS NO DIRECT EVIDENCE OF THIS. THIS HAS PHENOTYPIC CONSEQUENCES FOR PAIN AND MAY PROVIDE A NEW, EPIGENETICS-ASSOCIATED MECHANISM OF OPIOID-INDUCED HYPERALGESIA. THE RESULTS INDICATE A POTENTIAL INFLUENCE OF OPIOID ANALGESICS ON THE PATIENTS' EPIGENOME. THEY EMPHASIZE THE NEED FOR RELIABLE AND COST-EFFECTIVE SCREENING TOOLS AND MAY IMPLY THAT HIGH-THROUGHPUT SCREENING FOR LEAD COMPOUNDS IN ARTIFICIAL EXPRESSION SYSTEMS MAY NOT PROVIDE THE BEST TOOLS FOR IDENTIFYING NEW PAIN MEDICATIONS. 2013 6 1998 40 EPIGENETIC AND MIRNA EXPRESSION CHANGES IN PEOPLE WITH PAIN: A SYSTEMATIC REVIEW. ACCUMULATING EVIDENCE SUGGESTS THAT EPIGENETIC MECHANISMS MAY HOLD GREAT POTENTIAL IN THE FIELD OF PAIN. WE SYSTEMATICALLY REVIEWED THE LITERATURE EXPLORING EPIGENETIC MECHANISMS IN PEOPLE WITH PAIN. FOUR DATABASES HAVE BEEN INTERROGATED: MEDLINE, THE COCHRANE CENTRAL REGISTER OF CONTROLLED TRIAL, SCOPUS, AND WEB OF SCIENCE, FOLLOWING PRISMA GUIDELINES IN CONDUCTING STUDY SELECTION AND ASSESSMENT. THIRTY-SEVEN STUDIES WERE INCLUDED. STUDIES EXPLORED EPIGENETICS IN CONDITIONS SUCH AS FIBROMYALGIA, CRPS, NEUROPATHIES, OR OSTEOARTHRITIS. RESEARCH FOCUSSED ON GENOME-WIDE AND GENE-SPECIFIC DNA METHYLATION, AND MIRNA EXPRESSION. BIOINFORMATICS ANALYSES EXPLORING MIRNA-ASSOCIATED MOLECULAR PATHWAYS WERE ALSO PERFORMED. SEVERAL GENES ALREADY KNOWN FOR THEIR ROLE IN PAIN (BDNF, HDAC4, PRKG1, IL-17, TNFRSF13B, ETC.), AND SEVERAL MIRNAS LINKED TO INFLAMMATORY REGULATION, NOCICEPTIVE SIGNALLING AND PROTEIN KINASES FUNCTIONS HAVE BEEN FOUND TO DIFFER SIGNIFICANTLY BETWEEN PEOPLE WITH CHRONIC PAIN AND HEALTHY CONTROLS. ALTHOUGH THE STUDIES INCLUDED WERE CROSS-SECTIONAL IN NATURE, AND NO CONCLUSION ON CAUSAL LINKS BETWEEN EPIGENETIC CHANGES AND PAIN COULD BE DRAWN, WE SUMMARISED THE LARGE AMOUNT OF DATA AVAILABLE IN LITERATURE ON THE TOPIC, HIGHLIGHTING RESULTS THAT HAVE BEEN REPLICATED BY INDEPENDENT INVESTIGATIONS. THE FIELD OF PAIN EPIGENETICS APPEARS VERY EXCITING AND HAS ALL THE POTENTIAL TO LEAD TO REMARKABLE SCIENTIFIC ADVANCES. HOWEVER, HIGH-QUALITY, WELL-POWERED, LONGITUDINAL STUDIES ARE WARRANTED. PERSPECTIVE: THOUGH MORE HIGH-QUALITY RESEARCH IS NEEDED, AVAILABLE RESEARCH EXPLORING EPIGENETIC MECHANISMS OR MIRNAS IN PEOPLE WITH PAIN SHOWS THAT GENES REGULATING SYNAPTIC PLASTICITY AND EXCITABILITY, PROTEIN KINASES, AND ELEMENTS OF THE IMMUNE SYSTEM MIGHT HOLD GREAT POTENTIAL IN UNDERSTANDING THE PATHOPHYSIOLOGY OF DIFFERENT CONDITIONS. 2020 7 6159 42 THE GENETICS AND EPIGENETICS OF FATIGUE. FATIGUE IS A COMMON SYMPTOM AND INCLUDES BOTH PHYSICAL AND MENTAL COMPONENTS. IT CAN BE ASSOCIATED WITH A VARIETY OF DIFFERENT SYNDROMES AND DISEASES, BUT IN MANY CASES IS NOT ASSOCIATED WITH OTHER COMORBID CONDITIONS. MOST HUMANS HAVE EXPERIENCED ACUTE FATIGUE IN RELATION TO DIFFERENT STRESSORS. ACUTE FATIGUE TYPICALLY DECREASES AS THE EFFECT OF THE TRIGGERING FACTOR IS REDUCED AND A NORMAL HOMEOSTATIC BALANCE IS RESTORED. FATIGUE THAT PERSISTS FOR 6 MONTHS OR MORE IS TERMED CHRONIC FATIGUE. CHRONIC FATIGUE (CF) IN COMBINATION WITH A MINIMUM OF 4 OF 8 SYMPTOMS AND THE ABSENCE OF DISEASES THAT COULD EXPLAIN THESE SYMPTOMS, CONSTITUTE THE CASE DEFINITION FOR CHRONIC FATIGUE SYNDROME. IN SPITE OF ITS PREVALENCE, THE BIOLOGY OF FATIGUE IS RELATIVELY POORLY UNDERSTOOD AND BIOLOGICAL MARKERS HAVE NOT YET BEEN IDENTIFIED. THIS LITERATURE SEARCH WAS PERFORMED IN PUBMED TO IDENTIFY RESEARCH ON THE GENETICS AND EPIGENETICS OF FATIGUE. PUBLICATIONS WERE INCLUDED IF FATIGUE WAS A MAJOR TOPIC AND THE TOPIC WAS COMBINED WITH GENETIC AND/OR EPIGENETIC MEASUREMENTS IN ADULT HUMANS. A TOTAL OF 40 PUBLICATIONS WERE IDENTIFIED. ALTHOUGH ALTERED FUNCTIONING IN THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS, THE SEROTONERGIC SYSTEM, AND ASSOCIATIONS WITH INFECTIOUS AGENTS HAVE BEEN IDENTIFIED, THE SEARCH FOR GENETIC OR EPIGENETIC MARKERS OF FATIGUE, EITHER IN THE CONTEXT OF CF OR CHRONIC FATIGUE SYNDROME (CFS) HAS BEEN RELATIVELY UNPRODUCTIVE OR, IN THE CASE OF EPIGENETICS, NONEXISTENT. ALTHOUGH SEVERAL STUDIES, BOTH HYPOTHESIS-TESTING AND HYPOTHESIS-GENERATING, HAVE BEEN PERFORMED TO SEARCH FOR BIOMARKERS, THEY HAVE MOSTLY BEEN UNDERPOWERED, RESTRICTED BY THE HETEROGENEITY OF THE PHENOTYPE, OR LIMITED BY AN UNSYSTEMATIC STUDY DESIGN. TO BE ABLE TO CONFIRM THE HYPOTHESIS THAT RISK FOR, OR LEVELS OF, FATIGUE ARE INFLUENCED BY THE GENETIC OR EPIGENETIC BACKGROUND OF AN INDIVIDUAL, STUDIES NEED TO BE BASED ON LARGER SAMPLE SIZES WITH A MORE CLEARLY DEFINED PHENOTYPE. STUDIES NEED TO FOCUS NOT ONLY ON THE INFLUENCE OF A SINGLE ASPECT SUCH AS SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) OR DIFFERENTIAL GENE EXPRESSION ON DISEASE RISK OR STATE, BUT ALSO ON THE SYSTEMS BIOLOGY BEHIND THE DISEASE IN COMBINATION WITH INFORMATION ON ENVIRONMENTAL INFLUENCES AND VALIDATION OF FINDINGS IN FUNCTIONAL STUDIES. 2010 8 3994 36 LONGITUDINAL PROFILING IN PATIENTS UNDERGOING CARDIAC SURGERY REVEALS POSTOPERATIVE CHANGES IN DNA METHYLATION. BACKGROUND: CARDIAC SURGERY AND CARDIOPULMONARY BYPASS INDUCE A SUBSTANTIAL IMMUNE AND INFLAMMATORY RESPONSE, THE OVERACTIVATION OF WHICH IS ASSOCIATED WITH SIGNIFICANT PULMONARY, CARDIOVASCULAR, AND NEUROLOGIC COMPLICATIONS. COMMENSURATE WITH THE IMMUNE AND INFLAMMATORY RESPONSE ARE CHANGES IN THE HEART AND VASCULATURE ITSELF, WHICH TOGETHER DRIVE POSTOPERATIVE COMPLICATIONS THROUGH MECHANISMS THAT ARE POORLY UNDERSTOOD. LONGITUDINAL DNA METHYLATION PROFILING HAS THE POTENTIAL TO IDENTIFY CHANGES IN GENE REGULATORY MECHANISMS THAT ARE SECONDARY TO SURGERY AND TO IDENTIFY MOLECULAR PROCESSES THAT PREDICT AND/OR CAUSE POSTOPERATIVE COMPLICATIONS. IN THIS STUDY, WE MEASURE DNA METHYLATION IN PREOPERATIVE AND POSTOPERATIVE WHOLE BLOOD SAMPLES FROM 96 PATIENTS UNDERGOING CARDIAC SURGERY ON CARDIOPULMONARY BYPASS. RESULTS: WHILE THE VAST MAJORITY OF DNA METHYLATION IS UNCHANGED BY SURGERY AFTER ACCOUNTING FOR CHANGES IN CELL-TYPE COMPOSITION, WE IDENTIFY SEVERAL LOCI WITH STATISTICALLY SIGNIFICANT POSTOPERATIVE CHANGES IN METHYLATION. ADDITIONALLY, TWO OF THESE LOCI ARE ASSOCIATED WITH NEW-ONSET POSTOPERATIVE ATRIAL FIBRILLATION, A SIGNIFICANT COMPLICATION AFTER CARDIAC SURGERY. PAIRED STATISTICAL ANALYSIS, USE OF FACS DATA TO SUPPORT SUFFICIENT CONTROL OF CELL-TYPE HETEROGENEITY, AND MEASUREMENT OF IL6 LEVELS IN A SUBSET OF PATIENTS ADD RIGOR TO THIS ANALYSIS, ALLOWING US TO DISTINGUISH CELL-TYPE VARIABILITY FROM ACTUAL CHANGES IN METHYLATION. CONCLUSIONS: THIS STUDY IDENTIFIES SIGNIFICANT CHANGES IN DNA METHYLATION THAT OCCUR IMMEDIATELY AFTER CARDIAC SURGERY AND DEMONSTRATES THAT THESE ACUTE ALTERATIONS IN DNA METHYLATION HAVE THE GRANULARITY TO IDENTIFY PROCESSES ASSOCIATED WITH MAJOR POSTOPERATIVE COMPLICATIONS. THIS RESEARCH ALSO ESTABLISHES METHODS FOR CONTROLLING FOR CELL-TYPE VARIABILITY IN A LARGE HUMAN COHORT THAT MAY BE USEFUL TO DEPLOY IN OTHER LONGITUDINAL STUDIES OF EPIGENETIC MARKS IN THE SETTING OF ACUTE AND CHRONIC DISEASE. 2022 9 5039 36 PHARMACOGENETICS OF CHRONIC PAIN MANAGEMENT. OBJECTIVE: THE EXPERIENCE OF CHRONIC PAIN IS ONE OF THE COMMONEST REASONS INDIVIDUALS SEEK MEDICAL ATTENTION, MAKING THE MANAGEMENT OF CHRONIC PAIN A MAJOR ISSUE IN CLINICAL PRACTICE. DRUG METABOLISM AND RESPONSES ARE AFFECTED BY MANY FACTORS, WITH GENETIC VARIATIONS OFFERING ONLY A PARTIAL EXPLANATION OF AN INDIVIDUAL'S RESPONSE. THERE IS A PAUCITY OF EVIDENCE FOR THE BENEFITS OF PHARMACOGENETIC TESTING IN THE CONTEXT OF PAIN MANAGEMENT. DESIGN AND METHODS: WE REVIEWED THE LITERATURE BETWEEN 2000 AND 2013, AND REFERENCES CITED THEREIN, USING VARIOUS KEYWORDS RELATED TO PAIN MANAGEMENT, PHARMACOLOGY AND PHARMACOGENETICS. RESULTS: OPIOIDS CONTINUE TO BE THE MAINSTAY OF CHRONIC PAIN MANAGEMENT. SEVERAL NON-OPIOID BASED THERAPIES, SUCH AS TREATMENT WITH CANNABINOIDS, GENE THERAPY AND EPIGENETIC-BASED APPROACHES ARE NOW AVAILABLE FOR THESE PATIENTS. ADJUVANT THERAPIES WITH ANTIDEPRESSANTS, BENZODIAZEPINES OR ANTICONVULSANTS CAN ALSO BE USEFUL IN MANAGING PAIN. CURRENTLY, LABORATORY MONITORING OF PAIN MANAGEMENT PATIENTS, IF PERFORMED, IS LARGELY THROUGH URINE DRUG MEASUREMENTS. CONCLUSIONS: DRUG HALF-LIFE CALCULATIONS CAN BE USED AS FUNCTIONAL MARKERS OF THE CUMULATIVE EFFECT OF PHARMACOGENETICS AND DRUG-DRUG INTERACTIONS. ASSESSMENT OF HALF-LIFE AND THERAPEUTIC EFFECTS MAY BE MORE USEFUL THAN GENETIC TESTING IN PREVENTING ADVERSE DRUG REACTIONS TO PAIN MEDICATIONS, WHILE ENSURING EFFECTIVE ANALGESIA. DEFINITIVE, MASS SPECTROMETRY-BASED METHODS, CAPABLE OF MEASURING PARENT DRUG AND METABOLITE LEVELS, ARE THE MOST USEFUL ASSAYS FOR THIS PURPOSE. URINE DRUG MEASUREMENTS DO NOT NECESSARILY CORRELATE WITH SERUM DRUG CONCENTRATIONS OR THERAPEUTIC EFFECTS. THEREFORE, THEY ARE LIMITED IN THEIR USE IN MONITORING EFFICACY AND TOXICITY. 2014 10 1599 35 DNA METHYLATION SIGNATURE OF CHILDHOOD CHRONIC PHYSICAL AGGRESSION IN T CELLS OF BOTH MEN AND WOMEN. BACKGROUND: HIGH FREQUENCY OF PHYSICAL AGGRESSION IS THE CENTRAL FEATURE OF SEVERE CONDUCT DISORDER AND IS ASSOCIATED WITH A WIDE RANGE OF SOCIAL, MENTAL AND PHYSICAL HEALTH PROBLEMS. WE HAVE PREVIOUSLY TESTED THE HYPOTHESIS THAT DIFFERENTIAL DNA METHYLATION SIGNATURES IN PERIPHERAL T CELLS ARE ASSOCIATED WITH A CHRONIC AGGRESSION TRAJECTORY IN MALES. DESPITE THE FACT THAT SEX DIFFERENCES APPEAR TO PLAY A PIVOTAL ROLE IN DETERMINING THE DEVELOPMENT, MAGNITUDE AND FREQUENCY OF AGGRESSION, MOST OF PREVIOUS STUDIES FOCUSED ON MALES, SO LITTLE IS KNOWN ABOUT FEMALE CHRONIC PHYSICAL AGGRESSION. WE THEREFORE TESTED HERE WHETHER OR NOT THERE IS A SIGNATURE OF PHYSICAL AGGRESSION IN FEMALE DNA METHYLATION AND, IF THERE IS, HOW IT RELATES TO THE SIGNATURE OBSERVED IN MALES. METHODOLOGY/PRINCIPAL FINDINGS: METHYLATION PROFILES WERE CREATED USING THE METHOD OF METHYLATED DNA IMMUNOPRECIPITATION (MEDIP) FOLLOWED BY MICROARRAY HYBRIDIZATION AND STATISTICAL AND BIOINFORMATIC ANALYSES ON T CELL DNA OBTAINED FROM ADULT WOMEN WHO WERE FOUND TO BE ON A CHRONIC PHYSICAL AGGRESSION TRAJECTORY (CPA) BETWEEN 6 AND 12 YEARS OF AGE COMPARED TO WOMEN WHO FOLLOWED A NORMAL PHYSICAL AGGRESSION TRAJECTORY. WE CONFIRMED THE EXISTENCE OF A WELL-DEFINED, GENOME-WIDE SIGNATURE OF DNA METHYLATION ASSOCIATED WITH CHRONIC PHYSICAL AGGRESSION IN THE PERIPHERAL T CELLS OF ADULT FEMALES THAT INCLUDES MANY OF THE GENES SIMILARLY ASSOCIATED WITH PHYSICAL AGGRESSION IN THE SAME CELL TYPES OF ADULT MALES. CONCLUSIONS: THIS STUDY IN A SMALL NUMBER OF WOMEN PRESENTS PRELIMINARY EVIDENCE FOR A GENOME-WIDE VARIATION IN PROMOTER DNA METHYLATION THAT ASSOCIATES WITH CPA IN WOMEN THAT WARRANT LARGER STUDIES FOR FURTHER VERIFICATION. A SIGNIFICANT PROPORTION OF THESE ASSOCIATIONS WERE PREVIOUSLY OBSERVED IN MEN WITH CPA SUPPORTING THE HYPOTHESIS THAT THE EPIGENETIC SIGNATURE OF EARLY LIFE AGGRESSION IN FEMALES IS COMPOSED OF A COMPONENT SPECIFIC TO FEMALES AND ANOTHER COMMON TO BOTH MALES AND FEMALES. 2014 11 4035 36 MACHINE-LEARNED ANALYSIS OF GLOBAL AND GLIAL/OPIOID INTERSECTION-RELATED DNA METHYLATION IN PATIENTS WITH PERSISTENT PAIN AFTER BREAST CANCER SURGERY. BACKGROUND: GLIAL CELLS IN THE CENTRAL NERVOUS SYSTEM PLAY A KEY ROLE IN NEUROINFLAMMATION AND SUBSEQUENT CENTRAL SENSITIZATION TO PAIN. THEY ARE THEREFORE INVOLVED IN THE DEVELOPMENT OF PERSISTENT PAIN. ONE OF THE MAIN SITES OF INTERACTION OF THE IMMUNE SYSTEM WITH PERSISTENT PAIN HAS BEEN IDENTIFIED AS NEURO-IMMUNE CROSSTALK AT THE GLIAL-OPIOID INTERFACE. THE PRESENT STUDY EXAMINED A POTENTIAL ASSOCIATION BETWEEN THE DNA METHYLATION OF TWO KEY PLAYERS OF GLIAL/OPIOID INTERSECTION AND PERSISTENT POSTOPERATIVE PAIN. METHODS: IN A COHORT OF 140 WOMEN WHO HAD UNDERGONE BREAST CANCER SURGERY, AND WERE ASSIGNED BASED ON A 3-YEAR FOLLOW-UP TO EITHER A PERSISTENT OR NON-PERSISTENT PAIN PHENOTYPE, THE ROLE OF EPIGENETIC REGULATION OF KEY PLAYERS IN THE GLIAL-OPIOID INTERFACE WAS ASSESSED. THE METHYLATION OF GENES CODING FOR THE TOLL-LIKE RECEPTOR 4 (TLR4) AS A MAJOR MEDIATOR OF GLIAL CONTRIBUTIONS TO PERSISTENT PAIN OR FOR THE MU-OPIOID RECEPTOR (OPRM1) WAS ANALYZED AND ITS ASSOCIATION WITH THE PAIN PHENOTYPE WAS COMPARED WITH THAT CONFERRED BY GLOBAL GENOME-WIDE DNA METHYLATION ASSESSED VIA QUANTIFICATION OF THE METHYLATION IN THE RETROTRANSPOSON LINE1. RESULTS: TRAINING OF MACHINE LEARNING ALGORITHMS INDICATED THAT THE GLOBAL DNA METHYLATION PROVIDED A SIMILAR DIAGNOSTIC ACCURACY FOR PERSISTENT PAIN AS PREVIOUSLY ESTABLISHED NON-GENETIC PREDICTORS. HOWEVER, THE DIAGNOSIS CAN BE BASED ON A SINGLE DNA BASED MARKER. BY CONTRAST, THE METHYLATION OF TLR4 OR OPRM1 GENES COULD NOT CONTRIBUTE FURTHER TO THE ALLOCATION OF THE PATIENTS TO THE PAIN-RELATED PHENOTYPE GROUPS. CONCLUSIONS: WHILE CLEARLY SUPPORTING A PREDICTIVE UTILITY OF EPIGENETIC TESTING, THE PRESENT ANALYSIS CANNOT PROVIDE SUPPORT FOR SPECIFIC EPIGENETIC MODULATION OF PERSISTENT POSTOPERATIVE PAIN VIA METHYLATION OF TWO KEY GENES OF THE GLIAL-OPIOID INTERFACE. 2019 12 1314 22 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 13 1810 34 EFFECTS OF ANTIPSYCHOTICS ON THE BDNF IN SCHIZOPHRENIA. BRAIN-DERIVED NEUROTROPIC FACTOR (BDNF) IS INVOLVED IN THE DEVELOPMENT OF THE BRAIN, AND LIKELY INFLUENCES THE NEUROPLASTICITY IN SCHIZOPHRENIA. BDNF IS ALSO BELIEVED TO INTERACT WITH OTHER NEUROTRANSMITTER SYSTEMS IMPLICATED IN SCHIZOPHRENIA, SUCH AS DOPAMINE, GLUTAMATE, SEROTONIN AND GABA. THEREFORE, BDNF IS A CANDIDATE GENE FOR SCHIZOPHRENIA. IN PAST DECADES, THE BLOOD (SERUM OR PLASMA) BDNF PROTEIN LEVELS AND BDNF GENE ALLELES AND GENOTYPES TO THE CLINICAL FEATURES OF SCHIZOPHRENIA, SUCH AS AGE OF ONSET, CLINICAL SUBTYPES, SYMPTOM SEVERITY, AND DRUG RESPONSE, HAVE BEEN EVALUATED AMONG DIFFERENT POPULATIONS. HOWEVER, THE RESULTS ARE STILL INCONSISTENT. FURTHER, DIFFERENT DRUGS HAVE BEEN REPORTED TO HAVE DIFFERENT EFFECTS ON BDNF PROTEIN LEVELS. A CROSS-SECTIONAL SURVEY REVEALED THAT SERUM BDNF LEVELS IN CHRONIC SCHIZOPHRENIC PATIENTS TREATED WITH CLOZAPINE EXCEEDED THOSE OF PATIENTS TREATED WITH RISPERIDONE OR WITH TYPICAL ANTIPSYCHOTICS. IN RECENT TIMES, BDNF EPIGENETIC STUDIES HAVE ALSO BEEN CONDUCTED IN CLINICAL STUDIES OF SCHIZOPHRENIA TO ADDRESS THE QUESTION OF WHY PATIENTS WITH THE SAME GENE GENOTYPE AND ALLELES HAVE DIFFERENT CLINICAL PRESENTATIONS. IN ADDITION, THE EFFECTS OF DIFFERENT ANTIPSYCHOTIC DRUGS ON GENE METHYLATION AND PROTEIN ACETYLATION HAVE ALSO BEEN REPORTED. IN CONCLUSION, MORE DATA ARE NEEDED REGARDING BDNF IN THE BRAIN AND IN PERIPHERAL BLOOD, INCLUDING PROTEIN LEVELS, SINGLE NUCLEOTIDE POLYMORPHISMS, EPIGENETIC REGULATION, AND CLINICAL DATA IN ORDER TO UNDERSTAND THE ROLE OF BDNF IN SCHIZOPHRENIA. 2013 14 6838 24 [INTRODUCTION OF TRANSLATIONAL RESEARCH IN OMICS SCIENCE TO CLINICAL ANESTHESIA]. MUCH PROGRESS HAS BEEN MADE IN OMICS RESEARCH FOLLOWING COMPLETION OF THE HUMAN GENOME PROJECT. THIS COMPREHENSIVE ANALYSIS PRODUCED A NEW DISCIPLINE (I.E., BIOINFORMATICS), AND ITS FINDINGS CONTRIBUTED TO THE CLINICAL PRACTICE OF ANESTHESIOLOGY. GENOMES OF PATIENTS SHOW GENETIC VARIATIONS AND MAY PREDICT THE SENSITIVITY TO ANESTHETICS AND ANALGESICS, INCIDENCE OF ADVERSE EFFECTS, AND INTENSITY OF POSTSURGICAL PAIN. CHANGES IN THE TRANSCRIPTOMES OF PATIENTS MAY ALSO REFLECT ANESTHESIA-RELATED EXPRESSION PROFILES OF VARIOUS TYPES OF NEURONS IN THE BRAIN, AND INFORMATION ON SUCH CHANGES MAY CONTRIBUTE TO MOLECULAR TARGETED THERAPY IN ANESTHETIZED PATIENTS. IN ADDITION, NOVEL EPIGENOME RESEARCH MAY EXPLAIN WHY ENVIRONMENTS CHANGE THE PHENOTYPES OF CLINICAL ANESTHESIA. WE CURRENTLY HYPOTHESIZE THAT FEMALE GENDER IS ASSOCIATED WITH DNA METHYLATION IN PAIN-RELATED AND VOMITING-RELATED GENE PROMOTER REGIONS AT THE GENOME-WIDE LEVEL AND THAT EPIGENETIC MECHANISMS ARE INVOLVED IN GENDER DIFFERENCES IN ANESTHESIA PRACTICE. 2013 15 2108 35 EPIGENETIC FACTORS RELATED TO LOW BACK PAIN: A SYSTEMATIC REVIEW OF THE CURRENT LITERATURE. LOW BACK PAIN (LBP) IS ONE OF THE MOST COMMON CAUSES OF PAIN AND DISABILITY. AT PRESENT, TREATMENT AND INTERVENTIONS FOR ACUTE AND CHRONIC LOW BACK PAIN OFTEN FAIL TO PROVIDE SUFFICIENT LEVELS OF PAIN RELIEF, AND FULL FUNCTIONAL RESTORATION CAN BE CHALLENGING. CONSIDERING THE SIGNIFICANT SOCIO-ECONOMIC BURDEN AND RISK-TO-BENEFIT RATIO OF MEDICAL AND SURGICAL INTERVENTION IN LOW BACK PAIN PATIENTS, THE IDENTIFICATION OF RELIABLE BIOMARKERS SUCH AS EPIGENETIC FACTORS ASSOCIATED WITH LOW BACK PAIN COULD BE USEFUL IN CLINICAL PRACTICE. THE AIM OF THIS STUDY WAS TO REVIEW THE AVAILABLE LITERATURE REGARDING THE EPIGENETIC FACTORS ASSOCIATED WITH LOW BACK PAIN. THIS REVIEW WAS CARRIED OUT IN ACCORDANCE WITH PREFERENTIAL REPORTING ITEMS FOR SYSTEMATIC REVIEWS AND META-ANALYSES (PRISMA) GUIDELINES. THE SEARCH WAS CARRIED OUT IN OCTOBER 2022. ONLY PEER-REVIEWED ARTICLES WERE CONSIDERED FOR INCLUSION. FOURTEEN STUDIES WERE INCLUDED AND SHOWED PROMISING RESULTS IN TERMS OF RELIABLE MARKERS. EPIGENETIC MARKERS FOR LBP HAVE THE POTENTIAL TO SIGNIFICANTLY MODIFY DISEASE MANAGEMENT. MOST RECENT EVIDENCE SUGGESTS THAT EPIGENETICS IS A MORE PROMISING FIELD FOR THE IDENTIFICATION OF FACTORS ASSOCIATED WITH LBP, OFFERING A RATIONALE FOR FURTHER INVESTIGATION IN THIS FIELD WITH THE LONG-TERM GOAL OF FINDING EPIGENETIC BIOMARKERS THAT COULD CONSTITUTE BIOLOGICAL TARGETS FOR DISEASE MANAGEMENT AND TREATMENT. 2023 16 5645 25 SEX DEPENDENT ALTERATION OF EPIGENETIC MARKS AFTER CHRONIC MORPHINE TREATMENT IN MICE ORGANS. EPIGENETIC MARKS MAY BE ALSO AFFECTED BY SEVERAL FACTORS, SUCH AS AGE, LIFESTYLE, EARLY LIFE EXPERIENCES AND EXPOSURE TO CHEMICALS OR DRUGS, SUCH AS OPIOIDS. PREVIOUS STUDIES HAVE FOCUSED ON HOW MORPHINE EPIGENETICALLY REGULATES DIFFERENT REGIONS OF THE BRAIN THAT ARE IMPLICATED IN TOLERANCE, DEPENDENCE AND OTHER PSYCHIATRIC DISORDERS MORE RELATED TO THE PHYSIO-PATHOLOGICAL EFFECTS OF OPIOIDS. NEVERTHELESS, A SIGNIFICANT KNOWLEDGE GAP REMAINS REGARDING THE EFFECT OF CHRONIC TREATMENT ON OTHER ORGANS AND BIOLOGICAL SYSTEMS. THEREFORE, THE AIM OF THIS WORK IS TO INCREASE OUR KNOWLEDGE ABOUT THE IMPACT OF CHRONIC MORPHINE EXPOSURE ON DNA METHYLATION AND HISTONE MODIFICATION LEVELS IN EACH OF THE ORGANS OF MALE AND FEMALE MODEL MICE IN VIVO. OUR RESULTS REVEAL, FOR THE FIRST TIME, THAT CHRONIC MORPHINE TREATMENT INDUCED CHANGES IN DNA METHYLATION/HYDROXYMETHYLATION AND HISTONE MODIFICATION IN-VIVO AT THE SYSTEMIC LEVEL, REVEALING A POTENTIAL PHYSIOLOGICAL EFFECT ON THE REGULATION OF GENE EXPRESSION. NOTABLY, MORPHINE-INDUCED EPIGENETIC MODIFICATION OCCURS IN A SEX-DEPENDENT MANNER, REVEALING THE EXISTENCE OF DIFFERENT UNDERLYING MECHANISMS OF EPIGENETIC MODIFICATION IN MALE AND FEMALE MICE. 2021 17 2523 40 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 18 1967 39 EPIGENETIC ALTERATION OF THE DOPAMINE TRANSPORTER GENE IN ALCOHOL-DEPENDENT PATIENTS IS ASSOCIATED WITH AGE. CHRONIC ALCOHOL ABUSE AND DEPENDENCE ARE ASSOCIATED WITH DYSFUNCTIONAL DOPAMINERGIC NEUROTRANSMISSION IN MESOCORTICOLIMBIC CIRCUITS. GENETIC AND ENVIRONMENTAL FACTORS HAVE BEEN SHOWN TO MODULATE SUSCEPTIBILITY TO ALCOHOL DEPENDENCE, AND BOTH MAY ACT THROUGH EPIGENETIC MECHANISMS THAT CAN MODULATE GENE EXPRESSION, E.G. DNA METHYLATION AT CPG SITES. RECENT STUDIES HAVE SUGGESTED THAT DNA METHYLATION PATTERNS MAY CHANGE OVER TIME. HOWEVER, FEW DATA ARE AVAILABLE CONCERNING THE RATE OF THESE CHANGES IN SPECIFIC GENES. A RECENT STUDY FOUND THAT HYPERMETHYLATION OF THE PROMOTER OF THE DOPAMINE TRANSPORTER (DAT) GENE WAS POSITIVELY CORRELATED WITH ALCOHOL DEPENDENCE AND NEGATIVELY CORRELATED WITH ALCOHOL CRAVING. THE AIM OF THE PRESENT STUDY WAS TO REPLICATE THESE FINDINGS IN A LARGER SAMPLE OF ALCOHOL-DEPENDENT PATIENTS AND POPULATION-BASED CONTROLS MATCHED FOR AGE AND SEX. NO DIFFERENCE IN METHYLATION LEVEL WAS OBSERVED BETWEEN PATIENTS AND CONTROLS, AND NO DIFFERENCE IN METHYLATION LEVEL WAS OBSERVED BEFORE AND AFTER ALCOHOL WITHDRAWAL IN PATIENTS. HOWEVER, PATIENTS WITH MORE SEVERE CRAVING SHOWED A TREND TOWARDS LOWER DAT METHYLATION LEVELS (P = 0.07), WHICH IS CONSISTENT WITH PREVIOUS FINDINGS. FURTHERMORE, IN OUR OVERALL SAMPLE, DAT METHYLATION LEVELS INCREASED WITH AGE. INTERESTINGLY, A SEPARATE ANALYSIS OF PATIENTS SUGGESTED THAT THIS FINDING WAS MAINLY DRIVEN BY THE PATIENT GROUP. ALTHOUGH THE PRESENT DATA DO NOT CLARIFY WHETHER CHRONIC ALCOHOL ABUSE IS RESPONSIBLE FOR THIS PHENOMENON OR MERELY ENHANCES AN AGEING-SPECIFIC PROCESS, OUR FINDINGS SUGGEST THAT HYPERMETHYLATION IN ALCOHOL-DEPENDENT PATIENTS IS A CONSEQUENCE, RATHER THAN A CAUSE, OF THE DISORDER. 2014 19 311 38 ALCOHOL AND THE METHYLOME: DESIGN AND ANALYSIS CONSIDERATIONS FOR RESEARCH USING HUMAN SAMPLES. BACKGROUND: A GROWING NUMBER OF STUDIES IN HUMAN SAMPLES HAVE SOUGHT TO DETERMINE WHETHER CHRONIC ALCOHOL USE AND ALCOHOL USE DISORDERS (AUDS) MAY BE ASSOCIATED WITH EPIGENETIC FACTORS, SUCH AS DNA METHYLATION. WE REVIEW THE EXTANT LITERATURE IN LIGHT OF SOME OF THE CHALLENGES THAT CURRENTLY AFFECT THE DESIGN AND INTERPRETATION OF EPIGENETIC RESEARCH IN HUMAN SAMPLES. METHOD: A LITERATURE SEARCH WAS USED TO IDENTIFY STUDIES THAT HAVE EXAMINED DNA METHYLATION IN RELATION TO ALCOHOL USE OR AUDS IN HUMAN SAMPLES (THROUGH JULY 2013). A TOTAL OF 22 STUDIES WERE IDENTIFIED. RESULTS: ASSOCIATIONS WITH QUANTITATIVE OR DIAGNOSTIC PHENOTYPES OF ALCOHOL USE OR AUDS HAVE BEEN REPORTED FOR SEVERAL GENES. HOWEVER, ALL STUDIES TO DATE HAVE RELIED ON RELATIVELY SMALL SAMPLES AND CROSS-SECTIONAL STUDY DESIGNS. ADDITIONALLY, ATTEMPTS TO REPLICATE RESULTS HAVE BEEN RARE. MORE GENERALLY, RESEARCH PROGRESS IS HAMPERED BY SEVERAL ISSUES, INCLUDING LIMITATIONS OF THE TECHNOLOGIES USED TO ASSESS DNA METHYLATION, TISSUE- AND CELL-SPECIFICITY OF METHYLATION PATTERNS, THE DIFFICULTIES OF RELATING OBSERVED METHYLATION DIFFERENCES AT A GIVEN LOCUS TO A FUNCTIONAL EFFECT, AND LIMITED KNOWLEDGE ABOUT THE MOLECULAR MECHANISMS UNDERLYING THE EFFECTS OF ALCOHOL ON DNA METHYLATION. CONCLUSIONS: ALTHOUGH WE SHARE THE OPTIMISM THAT EPIGENETICS MAY LEAD TO NEW INSIGHTS INTO THE ETIOLOGY AND PATHOPHYSIOLOGY OF AUDS, THE METHODOLOGICAL AND SCIENTIFIC CHALLENGES ASSOCIATED WITH CONDUCTING METHYLOMIC RESEARCH IN HUMAN SAMPLES NEED TO BE CAREFULLY CONSIDERED WHEN DESIGNING AND EVALUATING SUCH STUDIES. 2013 20 2093 39 EPIGENETIC EFFECTS FOLLOWING ACUTE AND CHRONIC EXERCISE IN CARDIOVASCULAR DISEASE: A SYSTEMATIC REVIEW. INTRODUCTION: ACUTE EXERCISE AND EXERCISE TRAINING MAY CONFER EPIGENETIC MODIFICATIONS IN HEALTHY SUBJECTS. EPIGENETIC EFFECTS AFTER EXERCISE HAVE BEEN SHOWED IN PATIENTS WITH CARDIOVASCULAR DISEASE. THE AIM OF THIS SYSTEMATIC REVIEW WAS TO SUMMARIZE THE EVIDENCE FROM AVAILABLE CLINICAL TRIALS THAT STUDY EPIGENETIC ADAPTATIONS AFTER EXERCISE IN PATIENTS WITH CARDIOVASCULAR DISEASE. METHODS: THE SEARCH STRATEGY WAS PERFORMED IN PUBMED AND CENTRAL DATABASES ON ARTICLES PUBLISHED UNTIL SEPTEMBER 2020. STUDIES WITH TITLES AND ABSTRACTS RELEVANT TO EXERCISE EPIGENETIC MODIFICATION APPLIED TO CARDIOVASCULAR PATIENTS WERE FULLY EXAMINED. INCLUSION AND EXCLUSION CRITERIA WERE UTILIZED FOR STUDIES SCREENING. QUALITY ASSESSMENT WITH PEDRO SCALE AND EVALUATION BY TWO INDEPENDENT REVIEWERS WAS PERFORMED. RESULTS: OF THE 1714 ARTICLES RETRIEVED, 88 ARTICLES WERE ASSESSED FOR ELIGIBILITY CRITERIA AND 8 ARTICLES MATCHED OUR SEARCH CRITERIA AND FINALLY INCLUDED IN THE SYSTEMATIC ANALYSIS. THE ACUTE EXERCISE EPIGENETIC (MIRNAS) EFFECTS WERE ASSESSED IN THREE STUDIES AND THE CHRONIC EXERCISE TRAINING EFFECTS (MIRNAS AND DNA METHYLATION) IN SIX STUDIES. THE RESULTS HAVE SHOWN THAT THERE IS POSSIBLY AN ACUTE SIGNIFICANT EXERCISE EFFECT ON EPIGENETIC TARGETS WHICH IS MORE EVIDENT AFTER CHRONIC EXERCISE TRAINING. CONCLUSIONS: BY THE PRESENT SYSTEMATIC REVIEW, WE PROVIDE PRELIMINARY EVIDENCE OF BENEFICIAL EPIGENETIC ADAPTATIONS FOLLOWING ACUTE AND CHRONIC EXERCISE IN PATIENTS WITH CARDIOVASCULAR DISEASE. MORE CONTROLLED STUDIES ARE NEEDED TO CONFIRM SUCH EVIDENCE. 2021