1 5648 137 SEX DIFFERENCES IN OPIOID RESPONSE LINKED TO OPRM1 AND COMT GENES DNA METHYLATION/GENOTYPES CHANGES IN PATIENTS WITH CHRONIC PAIN. ANALGESIC-RESPONSE VARIABILITY IN CHRONIC NONCANCER PAIN (CNCP) HAS BEEN REPORTED DUE TO SEVERAL BIOLOGICAL AND ENVIRONMENTAL FACTORS. THIS STUDY WAS UNDERTAKEN TO EXPLORE SEX DIFFERENCES LINKED TO OPRM1 AND COMT DNA METHYLATION CHANGES AND GENETIC VARIANTS IN ANALGESIC RESPONSE. A RETROSPECTIVE STUDY WITH 250 REAL-WORLD CNCP OUTPATIENTS WAS PERFORMED IN WHICH DATA FROM DEMOGRAPHIC, CLINICAL, AND PHARMACOLOGICAL VARIABLES WERE COLLECTED. DNA METHYLATION LEVELS (CPG ISLAND) WERE EVALUATED BY PYROSEQUENCING, AND THEIR INTERACTION WITH THE OPRM1 (A118G) AND COMT (G472A) GENE POLYMORPHISMS WAS STUDIED. A PRIORI-PLANNED STATISTICAL ANALYSES WERE CONDUCTED TO COMPARE RESPONSES BETWEEN FEMALES AND MALES. SEX-DIFFERENTIAL OPRM1 DNA METHYLATION WAS OBSERVED TO BE LINKED TO LOWER OPIOID USE DISORDER (OUD) CASES FOR FEMALES (P = 0.006). PATIENTS WITH LOWER OPRM1 DNA METHYLATION AND THE PRESENCE OF THE MUTANT G-ALLELE REDUCED OPIOID DOSE REQUIREMENTS (P = 0.001), EQUAL FOR BOTH SEXES. MOREOVER, COMT DNA METHYLATION LEVELS WERE NEGATIVELY RELATED TO PAIN RELIEF (P = 0.020), QUALITY OF LIFE (P = 0.046), AND SOME ADVERSE EVENTS (PROBABILITY > 90%) SUCH AS CONSTIPATION, INSOMNIA, OR NERVOUSNESS. FEMALES WERE, SIGNIFICANTLY, 5 YEARS OLDER WITH HIGH ANXIETY LEVELS AND A DIFFERENT SIDE-EFFECTS DISTRIBUTION THAN MALES. THE ANALYSES DEMONSTRATED SIGNIFICANT DIFFERENCES BETWEEN FEMALES AND MALES RELATED TO OPRM1 SIGNALLING EFFICIENCY AND OUD, WITH A GENETIC-EPIGENETIC INTERACTION IN OPIOID REQUIREMENTS. THESE FINDINGS SUPPORT THE IMPORTANCE OF SEX AS A BIOLOGICAL VARIABLE TO BE FACTORED INTO CHRONIC PAIN-MANAGEMENT STUDIES. 2023 2 1537 33 DNA METHYLATION IN ADOLESCENTS WITH ANXIETY DISORDER: A LONGITUDINAL STUDY. ANXIETY DISORDERS (AD) TYPICALLY MANIFEST IN CHILDREN AND ADOLESCENTS AND MIGHT PERSIST INTO ADULTHOOD. HOWEVER, THERE ARE STILL FEW DATA CONCERNING EPIGENETIC MECHANISMS ASSOCIATED WITH ONSET, PERSISTENCE OR REMISSION OF AD OVER TIME. WE INVESTIGATED A COHORT OF ADOLESCENTS AND YOUNG ADULTS AT BASELINE (AGE; 13.19 +/- 2.38) AND AFTER 5 YEARS AND CLASSIFIED THEM ACCORDING TO THE AD DIAGNOSIS AND THEIR LONGITUDINAL TRAJECTORIES INTO 4 GROUPS: (1) TYPICALLY DEVELOPING COMPARISONS (TDC; CONTROL GROUP, N = 14); (2) INCIDENT (AD IN THE SECOND EVALUATION ONLY, N = 11); (3) PERSISTENT (AD IN BOTH EVALUATIONS, N = 14) AND (4) REMITTENT (AD IN THE FIRST EVALUATION ONLY, N = 8). DNA METHYLATION WAS EVALUATED WITH THE INFINIUM HUMANMETHYLATION450 BEADCHIP FROM SALIVA SAMPLES COLLECTED AT BOTH EVALUATIONS. GENE SET ENRICHMENT ANALYSIS WAS APPLIED TO CONSIDER BIOLOGICAL PATHWAYS. WE FOUND DECREASED DNA METHYLATION IN TDC GROUP WHILE THE CHRONIC CASES OF AD PRESENTED HYPERMETHYLATION IN CENTRAL NERVOUS SYSTEM DEVELOPMENT PATHWAYS. MOREOVER, WE SHOWED THAT THIS PERSISTENT GROUP ALSO PRESENTED HYPERMETHYLATION WHILE THE OTHER THREE GROUPS WERE ASSOCIATED WITH HYPOMETHYLATION IN NERVOUS SYSTEM DEVELOPMENT PATHWAY. INCIDENCE AND REMISSION GROUPS WERE ASSOCIATED WITH INCREASED AND DECREASED METHYLATION IN NEURON DEVELOPMENT PATHWAYS, RESPECTIVELY. LARGER STUDIES ARE LIKELY TO DETECT SPECIFIC GENES RELEVANT TO AD. 2018 3 344 41 ALTERED BDNF METHYLATION IN PATIENTS WITH CHRONIC MUSCULOSKELETAL PAIN AND HIGH BIOPSYCHOSOCIAL COMPLEXITY. PURPOSE: THE INTERMED INSTRUMENT, WHICH WAS DEVELOPED TO MEASURE PATIENT'S BIOPSYCHOSOCIAL (BPS) COMPLEXITY, REPRESENTS A POWERFUL DIAGNOSTIC AND THERAPEUTIC TOOL. EPIGENETIC CHANGES ARE THE INTERFACE BETWEEN SIGNALS FROM THE ENVIRONMENT AND GENETIC MODIFICATIONS, AFFECTING GENE EXPRESSION, IN PARTICULAR, BY DNA METHYLATION OF CPG DINUCLEOTIDES IN PROMOTOR REGIONS OF THE CORRESPONDING GENES. THE BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) GENE PLAYS A CRUCIAL ROLE IN THE CENTRAL SENSITIZATION (CS) OF PAIN. IN THIS STUDY, WE HYPOTHESIZED THAT CHRONIC PAIN MODIFIES THE METHYLATION LEVELS OF THE BDNF GENE IN A MANNER THAT IS INTERCONNECTED WITH THE BPS STATUS. PATIENTS AND METHODS: FIFTY-EIGHT CHRONIC MUSCULOSKELETAL PAIN PATIENTS (CMSP) WERE ENROLLED IN THE STUDY. DNA WAS EXTRACTED FROM BLOOD SAMPLES, THE METHYLATION LEVELS OF 13 CPG SITES IN THE BDNF PROMOTER WERE MEASURED BY PYROSEQUENCING, AND ASSOCIATION STUDIES WITH VARIOUS PATIENT PARAMETERS AND THE INTERMED SCORES WERE PERFORMED. RESULTS: INTERESTINGLY, A NEGATIVE CORRELATION (-0.40) WAS FOUND BETWEEN THE TOTAL INTERMED SCORES AND THE AVERAGE CPG METHYLATION VALUES OF THE BDNF GENE, BUT NO CORRELATION WAS OBSERVED WITH THE SEVERITY OF PAIN, DEGREE OF ANXIETY, DEPRESSION, OR KINESIOPHOBIA AND CATASTROPHISM. MOREOVER, THE ASSOCIATION WAS INDEPENDENT OF AGE, SEX AND LEVEL OF COMORBIDITIES. CONCLUSION: THIS RESULT SHOWS THAT CMSP, IN ASSOCIATION WITH ITS BIOPSYCHOSOCIAL CONTEXT, EPIGENETICALLY DECREASES THE DEGREE OF METHYLATION OF THE BDNF PROMOTER AND SHOULD THEREFORE INCREASE THE LEVEL OF BDNF TRANSCRIPTION. IT ALSO SUGGESTS A ROLE OF THE INTERMED TOOL TO DETECT A RELATIONSHIP BETWEEN THE BPS COMPLEXITY AND THE EPIGENETIC CONTROL OF A TARGET GENE. THE POSSIBLE UPREGULATION OF BDNF EXPRESSION MIGHT BE, AT LEAST IN PART, THE SIGNAL FOR CHRONIC PAIN-INDUCED CENTRAL SENSITIZATION (CS). THIS COULD PARTLY EXPLAIN WHY PATIENTS WITH A HIGHER LEVEL OF COMPLEXITY FEEL MORE PAIN THAN THOSE WITH LOWER COMPLEXITY. 2020 4 2079 33 EPIGENETIC DNA METHYLATION CHANGES ASSOCIATED WITH HEADACHE CHRONIFICATION: A RETROSPECTIVE CASE-CONTROL STUDY. BACKGROUND THE BIOLOGICAL MECHANISMS OF HEADACHE CHRONIFICATION ARE POORLY UNDERSTOOD. WE AIMED TO IDENTIFY CHANGES IN DNA METHYLATION ASSOCIATED WITH THE TRANSFORMATION FROM EPISODIC TO CHRONIC HEADACHE. METHODS PARTICIPANTS WERE RECRUITED FROM THE POPULATION-BASED NORWEGIAN HUNT STUDY. THIRTY-SIX FEMALE HEADACHE PATIENTS WHO TRANSFORMED FROM EPISODIC TO CHRONIC HEADACHE BETWEEN BASELINE AND FOLLOW-UP 11 YEARS LATER WERE MATCHED AGAINST 35 CONTROLS WITH EPISODIC HEADACHE. DNA METHYLATION WAS QUANTIFIED AT 485,000 CPG SITES, AND CHANGES IN METHYLATION LEVEL AT THESE SITES WERE COMPARED BETWEEN CASES AND CONTROLS BY LINEAR REGRESSION ANALYSIS. DATA WERE ANALYZED IN TWO STAGES (STAGES 1 AND 2) AND IN A COMBINED META-ANALYSIS. RESULTS NONE OF THE TOP 20 CPG SITES IDENTIFIED IN STAGE 1 REPLICATED IN STAGE 2 AFTER MULTIPLE TESTING CORRECTION. IN THE COMBINED META-ANALYSIS THE STRONGEST ASSOCIATED CPG SITES WERE RELATED TO SH2D5 AND NPTX2, TWO BRAIN-EXPRESSED GENES INVOLVED IN THE REGULATION OF SYNAPTIC PLASTICITY. FUNCTIONAL ENRICHMENT ANALYSIS POINTED TO PROCESSES INCLUDING CALCIUM ION BINDING AND ESTROGEN RECEPTOR PATHWAYS. CONCLUSION IN THIS FIRST GENOME-WIDE STUDY OF DNA METHYLATION IN HEADACHE CHRONIFICATION SEVERAL POTENTIALLY IMPLICATED LOCI AND PROCESSES WERE IDENTIFIED. THE STUDY EXEMPLIFIES THE USE OF PROSPECTIVELY COLLECTED POPULATION COHORTS TO SEARCH FOR EPIGENETIC MECHANISMS OF DISEASE. 2018 5 3652 32 INDIVIDUAL DNA METHYLATION PATTERN SHIFTS IN NANOPARTICLES-EXPOSED WORKERS ANALYZED IN FOUR CONSECUTIVE YEARS. A DNA METHYLATION PATTERN REPRESENTS AN ORIGINAL PLAN OF THE FUNCTION SETTINGS OF INDIVIDUAL CELLS AND TISSUES. THE BASIC STRATEGIES OF ITS DEVELOPMENT AND CHANGES DURING THE HUMAN LIFETIME ARE KNOWN, BUT THE DETAILS RELATED TO ITS MODIFICATION OVER THE YEARS ON AN INDIVIDUAL BASIS HAVE NOT YET BEEN STUDIED. MOREOVER, CURRENT EVIDENCE SHOWS THAT ENVIRONMENTAL EXPOSURE COULD GENERATE CHANGES IN DNA METHYLATION SETTINGS AND, SUBSEQUENTLY, THE FUNCTION OF GENES. IN THIS STUDY, WE ANALYZED THE EFFECT OF CHRONIC EXPOSURE TO NANOPARTICLES (NP) IN OCCUPATIONALLY EXPOSED WORKERS REPEATEDLY SAMPLED IN FOUR CONSECUTIVE YEARS (2016-2019). A DETAILED METHYLATION PATTERN ANALYSIS OF 14 PERSONS (10 EXPOSED AND 4 CONTROLS) WAS PERFORMED ON AN INDIVIDUAL BASIS. A MICROARRAY-BASED APPROACH USING CHIPS, ALLOWING THE ASSESSMENT OF MORE THAN 850 K CPG LOCI, WAS USED. INDIVIDUAL DNA METHYLATION PATTERNS WERE COMPARED BY PRINCIPAL COMPONENT ANALYSIS (PCA). THE RESULTS SHOW THE SHIFT IN DNA METHYLATION PATTERNS IN INDIVIDUAL YEARS IN ALL THE EXPOSED AND CONTROL SUBJECTS. THE OVERALL RANGE OF DIFFERENCES VARIED BETWEEN THE YEARS IN INDIVIDUAL PERSONS. THE DIFFERENCES BETWEEN THE FIRST AND LAST YEAR OF EXAMINATION (A THREE-YEAR TIME PERIOD) SEEM TO BE CONSISTENTLY GREATER IN THE NP-EXPOSED SUBJECTS IN COMPARISON WITH THE CONTROLS. THE SELECTED 14 MOST DIFFERENTLY METHYLATED CG LOCI WERE RELATIVELY STABLE IN THE CHRONICALLY EXPOSED SUBJECTS. IN SUMMARY, THE SPECIFIC TYPE OF LONG-TERM EXPOSURE CAN CONTRIBUTE TO THE FIXING OF RELEVANT EPIGENETIC CHANGES RELATED TO A SPECIFIC ENVIRONMENT AS, E.G., NP INHALATION. 2021 6 1345 36 DETECTION OF DIFFERENTIALLY METHYLATED REGIONS USING BAYES FACTOR FOR ORDINAL GROUP RESPONSES. RESEARCHERS IN GENOMICS ARE INCREASINGLY INTERESTED IN EPIGENETIC FACTORS SUCH AS DNA METHYLATION, BECAUSE THEY PLAY AN IMPORTANT ROLE IN REGULATING GENE EXPRESSION WITHOUT CHANGES IN THE DNA SEQUENCE. THERE HAVE BEEN SIGNIFICANT ADVANCES IN DEVELOPING STATISTICAL METHODS TO DETECT DIFFERENTIALLY METHYLATED REGIONS (DMRS) ASSOCIATED WITH BINARY DISEASE STATUS. MOST OF THESE METHODS ARE BEING DEVELOPED FOR DETECTING DIFFERENTIAL METHYLATION RATES BETWEEN CASES AND CONTROLS. WE CONSIDER MULTIPLE SEVERITY LEVELS OF DISEASE, AND DEVELOP A BAYESIAN STATISTICAL METHOD TO DETECT THE REGION WITH INCREASING (OR DECREASING) METHYLATION RATES AS THE DISEASE SEVERITY INCREASES. PATIENTS ARE CLASSIFIED INTO MORE THAN TWO GROUPS, BASED ON THE DISEASE SEVERITY (E.G., STAGES OF CANCER), AND DMRS ARE DETECTED BY USING MOVING WINDOWS ALONG THE GENOME. WITHIN EACH WINDOW, THE BAYES FACTOR IS CALCULATED TO TEST THE HYPOTHESIS OF MONOTONIC INCREASE IN METHYLATION RATES CORRESPONDING TO SEVERITY OF THE DISEASE VERSUS NO DIFFERENCE. A MIXED-EFFECT MODEL IS USED TO INCORPORATE THE CORRELATION OF METHYLATION RATES OF NEARBY CPG SITES IN THE REGION. RESULTS FROM EXTENSIVE SIMULATION INDICATE THAT OUR PROPOSED METHOD IS STATISTICALLY VALID AND REASONABLY POWERFUL. WE DEMONSTRATE OUR APPROACH ON A BISULFITE SEQUENCING DATASET FROM A CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) STUDY. 2019 7 6311 28 THE RELATION BETWEEN DNA METHYLATION PATTERNS AND SERUM CYTOKINE LEVELS IN COMMUNITY-DWELLING ADULTS: A PRELIMINARY STUDY. BACKGROUND: THE LEVELS OF CIRCULATING CYTOKINES FLUCTUATE WITH AGE, ACUTE ILLNESS, AND CHRONIC DISEASE, AND ARE PREDICTIVE OF MORTALITY; THIS IS ALSO TRUE FOR PATTERNS OF DNA (CPG) METHYLATION. GIVEN THAT IMMUNE CELLS ARE PARTICULARLY SENSITIVE TO CHANGES IN THE CONCENTRATION OF CYTOKINES IN THEIR MICROENVIRONMENT, WE HYPOTHESIZED THAT SERUM LEVELS OF TNF, IL-6, IL-8 AND IL-10 WOULD CORRELATE WITH GENOME-WIDE ALTERATIONS IN THE DNA METHYLATION LEVELS OF BLOOD LEUKOCYTES. TO TEST THIS, WE EVALUATED COMMUNITY-DWELLING ADULTS (N = 14; 48-78 YEARS OLD) RECRUITED TO A PILOT STUDY FOR THE CANADIAN LONGITUDINAL STUDY ON AGING (CLSA), EXAMINING DNA METHYLATION PATTERNS IN PERIPHERAL BLOOD MONONUCLEAR CELLS USING THE ILLUMINA HUMANMETHYLATION 450 K BEADCHIP. RESULTS: WE SHOW THAT, APART FROM AGE, SERUM IL-10 LEVELS EXHIBITED THE MOST SUBSTANTIAL ASSOCIATION TO DNA METHYLATION PATTERNS, FOLLOWED BY TNF, IL-6 AND IL-8. FURTHERMORE, WHILE THE LEVELS OF THESE CYTOKINES WERE HIGHER IN ELDERLY ADULTS, NO ASSOCIATIONS WITH EPIGENETIC ACCELERATED AGING, DERIVED USING THE EPIGENETIC CLOCK, WERE OBSERVED. CONCLUSIONS: AS A PRELIMINARY STUDY WITH A SMALL SAMPLE SIZE, THE CONCLUSIONS DRAWN FROM THIS WORK MUST BE VIEWED WITH CAUTION; HOWEVER, OUR OBSERVATIONS ARE ENCOURAGING AND CERTAINLY WARRANT MORE SUITABLY POWERED STUDIES OF THIS RELATIONSHIP. 2017 8 1436 25 DIFFERENTIAL METHYLATION OF THE TRPA1 PROMOTER IN PAIN SENSITIVITY. CHRONIC PAIN IS A GLOBAL PUBLIC HEALTH PROBLEM, BUT THE UNDERLYING MOLECULAR MECHANISMS ARE NOT FULLY UNDERSTOOD. HERE WE EXAMINE GENOME-WIDE DNA METHYLATION, FIRST IN 50 IDENTICAL TWINS DISCORDANT FOR HEAT PAIN SENSITIVITY AND THEN IN 50 FURTHER UNRELATED INDIVIDUALS. WHOLE-BLOOD DNA METHYLATION WAS CHARACTERIZED AT 5.2 MILLION LOCI BY MEDIP SEQUENCING AND ASSESSED LONGITUDINALLY TO IDENTIFY DIFFERENTIALLY METHYLATED REGIONS ASSOCIATED WITH HIGH OR LOW PAIN SENSITIVITY (PAIN DMRS). NINE META-ANALYSIS PAIN DMRS SHOW ROBUST EVIDENCE FOR ASSOCIATION (FALSE DISCOVERY RATE 5%) WITH THE STRONGEST SIGNAL IN THE PAIN GENE TRPA1 (P=1.2 X 10(-13)). SEVERAL PAIN DMRS SHOW LONGITUDINAL STABILITY CONSISTENT WITH SUSCEPTIBILITY EFFECTS, HAVE SIMILAR METHYLATION LEVELS IN THE BRAIN AND ALTERED EXPRESSION IN THE SKIN. OUR APPROACH IDENTIFIES EPIGENETIC CHANGES IN BOTH NOVEL AND ESTABLISHED CANDIDATE GENES THAT PROVIDE MOLECULAR INSIGHTS INTO PAIN AND MAY GENERALIZE TO OTHER COMPLEX TRAITS. 2014 9 5034 27 PHARMACOEPIGENETICS OF THE ROLE OF DNA METHYLATION IN MU-OPIOID RECEPTOR EXPRESSION IN DIFFERENT HUMAN BRAIN REGIONS. AIM: EXPOSURE TO OPIOIDS HAS BEEN ASSOCIATED WITH EPIGENETIC EFFECTS. STUDIES IN RODENTS SUGGESTED A ROLE OF VARYING DEGREES OF DNA METHYLATION IN THE DIFFERENTIAL REGULATION OF MU-OPIOID RECEPTOR EXPRESSION ACROSS THE BRAIN. METHODS: IN A TRANSLATIONAL INVESTIGATION, USING TISSUE ACQUIRED POSTMORTEM FROM 21 BRAIN REGIONS OF FORMER OPIATE ADDICTS, REPRESENTING A HUMAN COHORT WITH CHRONIC OPIOID EXPOSURE, MU-OPIOID RECEPTOR EXPRESSION WAS ANALYZED AT THE LEVEL OF DNA METHYLATION, MRNA AND PROTEIN. RESULTS & CONCLUSION: WHILE HIGH OR LOW MU-OPIOID RECEPTOR EXPRESSION SIGNIFICANTLY CORRELATED WITH LOCAL OPRM1 MRNA LEVELS, THERE WAS NO CORRESPONDING ASSOCIATION WITH OPRM1 METHYLATION STATUS. ADDITIONAL EXPERIMENTS IN HUMAN CELL LINES SHOWED THAT CHANGES IN DNA METHYLATION ASSOCIATED WITH CHANGES IN MU-OPIOID EXPRESSION WERE AN ORDER OF MAGNITUDE GREATER THAN DIFFERENCES IN BRAIN. HENCE, DIFFERENT DEGREES OF DNA METHYLATION ASSOCIATED WITH CHRONIC OPIOID EXPOSURE ARE UNLIKELY TO EXERT A MAJOR ROLE IN THE REGION-SPECIFICITY OF MU-OPIOID RECEPTOR EXPRESSION IN THE HUMAN BRAIN. 2016 10 1967 43 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 11 1503 33 DNA METHYLATION AND GENE EXPRESSION DIFFERENCES IN CHILDREN CONCEIVED IN VITRO OR IN VIVO. EPIDEMIOLOGICAL DATA INDICATE THAT CHILDREN CONCEIVED IN VITRO HAVE A GREATER RELATIVE RISK OF LOW BIRTH-WEIGHT, MAJOR AND MINOR BIRTH DEFECTS, AND RARE DISORDERS INVOLVING IMPRINTED GENES, SUGGESTING THAT EPIGENETIC CHANGES MAY BE ASSOCIATED WITH ASSISTED REPRODUCTION. WE EXAMINED DNA METHYLATION AT MORE THAN 700 GENES (1536 CPG SITES) IN PLACENTA AND CORD BLOOD AND MEASURED GENE EXPRESSION LEVELS OF A SUBSET OF GENES THAT DIFFERED IN METHYLATION LEVELS BETWEEN CHILDREN CONCEIVED IN VITRO VERSUS IN VIVO. OUR RESULTS SUGGEST THAT IN VITRO CONCEPTION IS ASSOCIATED WITH LOWER MEAN METHYLATION AT CPG SITES IN PLACENTA AND HIGHER MEAN METHYLATION AT CPG SITES IN CORD BLOOD. WE ALSO FIND THAT IN VITRO CONCEPTION-ASSOCIATED DNA METHYLATION DIFFERENCES ARE ASSOCIATED WITH GENE EXPRESSION DIFFERENCES AT BOTH IMPRINTED AND NON-IMPRINTED GENES. THE RANGE OF INTER-INDIVIDUAL VARIATION IN GENE EXPRESSION OF THE IN VITRO AND IN VIVO GROUPS OVERLAPS SUBSTANTIALLY BUT SOME INDIVIDUALS FROM THE IN VITRO GROUP DIFFER FROM THE IN VIVO GROUP MEAN BY MORE THAN TWO STANDARD DEVIATIONS. SEVERAL OF THE GENES WHOSE EXPRESSION DIFFERS BETWEEN THE TWO GROUPS HAVE BEEN IMPLICATED IN CHRONIC METABOLIC DISORDERS, SUCH AS OBESITY AND TYPE II DIABETES. THESE FINDINGS SUGGEST THAT THERE MAY BE EPIGENETIC DIFFERENCES IN THE GAMETES OR EARLY EMBRYOS DERIVED FROM COUPLES UNDERGOING TREATMENT FOR INFERTILITY. ALTERNATIVELY, ASSISTED REPRODUCTION TECHNOLOGY MAY HAVE AN EFFECT ON GLOBAL PATTERNS OF DNA METHYLATION AND GENE EXPRESSION. IN EITHER CASE, THESE DIFFERENCES OR CHANGES MAY AFFECT LONG-TERM PATTERNS OF GENE EXPRESSION. 2009 12 577 34 BDNF PROMOTER METHYLATION AND GENETIC VARIATION IN LATE-LIFE DEPRESSION. THE REGULATION OF THE BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IS IMPORTANT FOR DEPRESSION PATHOPHYSIOLOGY AND EPIGENETIC REGULATION OF THE BDNF GENE MAY BE INVOLVED. THIS STUDY INVESTIGATED WHETHER BDNF METHYLATION IS A MARKER OF DEPRESSION. ONE THOUSAND AND TWENTY-FOUR PARTICIPANTS WERE RECRUITED AS PART OF A LONGITUDINAL STUDY OF PSYCHIATRIC DISORDERS IN GENERAL POPULATION ELDERLY (AGE ? 65). CLINICAL LEVELS OF DEPRESSION WERE ASSESSED USING THE MINI INTERNATIONAL NEUROPSYCHIATRIC INTERVIEW FOR THE DIAGNOSIS OF MAJOR DEPRESSIVE DISORDER ACCORDING TO THE DIAGNOSTIC AND STATISTICAL MANUAL OF MENTAL DISORDER IV CRITERIA, AND THE CENTRE FOR EPIDEMIOLOGIC STUDIES DEPRESSION SCALE (CES-D) FOR ASSESSMENT OF MODERATE TO SEVERE DEPRESSIVE SYMPTOMS. BUCCAL DNA METHYLATION AT THE TWO MOST WIDELY STUDIED BDNF PROMOTERS, I AND IV, WAS INVESTIGATED USING THE SEQUENOM MASSARRAY PLATFORM THAT ALLOWS HIGH-THROUGHPUT INVESTIGATION OF METHYLATION AT INDIVIDUAL CPG SITES WITHIN DEFINED GENOMIC REGIONS. IN MULTIVARIATE LINEAR REGRESSION ANALYSES ADJUSTED FOR A RANGE OF PARTICIPANT CHARACTERISTICS INCLUDING ANTIDEPRESSANT USE, DEPRESSION AT BASELINE, AS WELL AS CHRONIC LATE-LIFE DEPRESSION OVER THE 12-YEAR FOLLOW-UP, WERE ASSOCIATED WITH OVERALL HIGHER BDNF METHYLATION LEVELS, WITH TWO SITES SHOWING SIGNIFICANT ASSOCIATIONS (PROMOTER I, DELTA MEAN = 0.4%, P = 0.0002; PROMOTER IV, DELTA MEAN = 5.4%, P = 0.021). THREE SINGLE-NUCLEOTIDE POLYMORPHISMS (RS6265, RS7103411 AND RS908867) WERE ALSO FOUND TO MODIFY THE ASSOCIATION BETWEEN DEPRESSION AND PROMOTER I METHYLATION. AS ONE OF THE LARGEST EPIGENETIC STUDIES OF DEPRESSION, AND THE FIRST INVESTIGATING BDNF METHYLATION IN BUCCAL TISSUE, OUR FINDINGS HIGHLIGHT THE POTENTIAL FOR BUCCAL BDNF METHYLATION TO BE A BIOMARKER OF DEPRESSION. 2015 13 524 29 ASSOCIATIONS OF BDNF GENOTYPE AND PROMOTER METHYLATION WITH ACUTE AND LONG-TERM STROKE OUTCOMES IN AN EAST ASIAN COHORT. BACKGROUND: BRAIN DERIVED NEUROTROPHIC FACTOR (BDNF) HAS BEEN SHOWN TO PLAY AN IMPORTANT ROLE IN POSTSTROKE RECOVERY. BDNF SECRETION IS INFLUENCED BY GENETIC AND EPIGENETIC PROFILES. THIS STUDY AIMED TO INVESTIGATE WHETHER BDNF VAL66MET POLYMORPHISM AND PROMOTER METHYLATION STATUS WERE ASSOCIATED WITH OUTCOMES AT TWO WEEKS AND ONE YEAR AFTER STROKE. METHODS AND FINDINGS: A TOTAL OF 286 PATIENTS WERE EVALUATED AT THE TIME OF ADMISSION AND TWO WEEKS AFTER STROKE, AND 222 (78%) WERE FOLLOWED ONE YEAR LATER IN ORDER TO EVALUATE CONSEQUENCES OF STROKE AT BOTH ACUTE AND CHRONIC STAGES. STROKE OUTCOMES WERE DICHOTOMISED INTO GOOD AND POOR BY THE MODIFIED RANKIN SCALE. STROKE SEVERITY (NATIONAL INSTITUTES OF HEALTH STROKE SCALE), PHYSICAL DISABILITY (BARTHEL INDEX), AND COGNITIVE FUNCTION (MINI-MENTAL STATE EXAMINATION) WERE MEASURED. ASSOCIATIONS OF BDNF GENOTYPE AND METHYLATION STATUS ON STROKE OUTCOMES AND ASSESSMENT SCALE SCORES WERE INVESTIGATED USING LOGISTIC REGRESSION, REPEATED MEASURES ANOVA AND PARTIAL CORRELATION TESTS. BDNF VAL66MET POLYMORPHISM WAS INDEPENDENTLY ASSOCIATED WITH POOR OUTCOME AT 2 WEEKS AND AT 1 YEAR, AND WITH WORSENING PHYSICAL DISABILITY AND COGNITIVE FUNCTION OVER THAT PERIOD. HIGHER BDNF PROMOTER METHYLATION STATUS WAS INDEPENDENTLY ASSOCIATED WITH WORSE OUTCOMES AT 1 YEAR, AND WITH THE WORSENING OF PHYSICAL DISABILITY AND COGNITIVE FUNCTION. NO SIGNIFICANT GENOTYPE-METHYLATION INTERACTIONS WERE FOUND. CONCLUSIONS: A ROLE FOR BDNF IN POSTSTROKE RECOVERY WAS SUPPORTED, AND CLINICAL UTILITY OF BDNF GENETIC AND EPIGENETIC PROFILE AS PROGNOSTIC BIOMARKERS AND A TARGET FOR DRUG DEVELOPMENT WAS SUGGESTED. 2012 14 2078 27 EPIGENETIC DIVERGENCE IN THE TRPA1 PROMOTER CORRELATES WITH PRESSURE PAIN THRESHOLDS IN HEALTHY INDIVIDUALS. THE EXPRESSION PATTERN OF IMPORTANT TRANSDUCTION MOLECULES IN NOCICEPTIVE SENSORY NEURONS IS LIKELY TO DICTATE PAIN SENSITIVITY. WHILE THIS NOTION IS WELL ESTABLISHED FOR INCREASED PAIN SENSITIVITIES UNDER CONDITIONS LIKE INFLAMMATION AND NEUROPATHY, LESS IS KNOWN AS TO WHICH MOLECULES ARE DEFINING INTERINDIVIDUAL DIFFERENCES IN PAIN SENSITIVITY IN HEALTHY SUBJECTS. A GENOME-WIDE METHYLATION ANALYSIS ON MONOZYGOTIC TWINS FOUND THAT METHYLATION OF A CPG DINUCLEOTIDE IN THE PROMOTER OF TRANSIENT RECEPTOR POTENTIAL ANKYRIN 1 (TRPA1) IS INVERSELY ASSOCIATED WITH THE THRESHOLD FOR HEAT-INDUCED PAIN. SEVERAL IN VITRO STUDIES ALSO SUGGEST THAT TRPA1 MEDIATES MECHANICAL SENSITIVITY OF SENSORY AFFERENTS, THUS POTENTIALLY MEDIATING PRESSURE-EVOKED PAIN. IN THE PRESENT STUDY, WE THEREFORE INVESTIGATED THE EPIGENETIC PREDISPOSITION FOR PRESSURE PAIN BY ANALYZING THE METHYLATION STATUS OF 47 CPG SITES IN THE PROMOTER REGION OF TRPA1. USING DNA FROM WHOLE-BLOOD SAMPLES OF 75 HEALTHY VOLUNTEERS, WE FOUND THAT THE SAME CPG SITE PREVIOUSLY FOUND TO AFFECT THE THRESHOLD FOR HEAT-EVOKED PAIN IS HYPERMETHYLATED IN SUBJECTS WITH A LOW THRESHOLD FOR PRESSURE PAIN. WE ALSO FOUND GENDER DIFFERENCES, WITH FEMALES DISPLAYING HIGHER METHYLATION RATES COMBINED WITH HIGHER PRESSURE PAIN SENSITIVITIES AS COMPARED WITH MALES. IN CONCLUSION, OUR FINDINGS SUPPORT THE NOTION THAT EPIGENETIC REGULATION OF TRPA1 SEEMS TO REGULATE THERMAL AND MECHANICAL PAIN SENSITIVITIES. 2017 15 1599 37 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 16 1497 25 DNA METHYLATION AGE IS ACCELERATED IN ALCOHOL DEPENDENCE. ALCOHOL DEPENDENCE (ALC) IS A CHRONIC, RELAPSING DISORDER THAT INCREASES THE BURDEN OF CHRONIC DISEASE AND SIGNIFICANTLY CONTRIBUTES TO NUMEROUS PREMATURE DEATHS EACH YEAR. PREVIOUS RESEARCH SUGGESTS THAT CHRONIC, HEAVY ALCOHOL CONSUMPTION IS ASSOCIATED WITH DIFFERENTIAL DNA METHYLATION PATTERNS. IN ADDITION, DNA METHYLATION LEVELS AT CERTAIN CPG SITES HAVE BEEN CORRELATED WITH AGE. WE USED AN EPIGENETIC CLOCK TO INVESTIGATE THE POTENTIAL ROLE OF EXCESSIVE ALCOHOL CONSUMPTION IN EPIGENETIC AGING. WE EXPLORED THIS QUESTION IN FIVE INDEPENDENT COHORTS, INCLUDING DNA METHYLATION DATA DERIVED FROM DATASETS FROM BLOOD (N = 129, N = 329), LIVER (N = 92, N = 49), AND POSTMORTEM PREFRONTAL CORTEX (N = 46). ONE BLOOD DATASET AND ONE LIVER TISSUE DATASET OF INDIVIDUALS WITH ALC EXHIBITED POSITIVE AGE ACCELERATION (P < 0.0001 AND P = 0.0069, RESPECTIVELY), WHEREAS THE OTHER BLOOD AND LIVER TISSUE DATASETS BOTH EXHIBITED TRENDS OF POSITIVE AGE ACCELERATION THAT WERE NOT SIGNIFICANT (P = 0.83 AND P = 0.57, RESPECTIVELY). PREFRONTAL CORTEX TISSUE EXHIBITED A TREND OF NEGATIVE AGE ACCELERATION (P = 0.19). THESE RESULTS SUGGEST THAT EXCESSIVE ALCOHOL CONSUMPTION MAY BE ASSOCIATED WITH EPIGENETIC AGING IN A TISSUE-SPECIFIC MANNER AND WARRANTS FURTHER INVESTIGATION USING MULTIPLE TISSUE SAMPLES FROM THE SAME INDIVIDUALS. 2018 17 6547 32 TRANSCRIPTOMICS OF LONG-TERM MEDITATION PRACTICE: EVIDENCE FOR PREVENTION OR REVERSAL OF STRESS EFFECTS HARMFUL TO HEALTH. BACKGROUND AND OBJECTIVES: STRESS CAN OVERLOAD ADAPTIVE MECHANISMS, LEADING TO EPIGENETIC EFFECTS HARMFUL TO HEALTH. RESEARCH ON THE REVERSAL OF THESE EFFECTS IS IN ITS INFANCY. EARLY RESULTS SUGGEST SOME MEDITATION TECHNIQUES HAVE HEALTH BENEFITS THAT GROW WITH REPEATED PRACTICE. THIS STUDY FOCUSED ON POSSIBLE TRANSCRIPTOMIC EFFECTS OF 38 YEARS OF TWICE-DAILY TRANSCENDENTAL MEDITATION((R)) (TM((R))) PRACTICE. MATERIALS AND METHODS: FIRST, USING ILLUMINA((R)) BEADCHIP MICROARRAY TECHNOLOGY, DIFFERENCES IN GLOBAL GENE EXPRESSION IN PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) WERE SOUGHT BETWEEN HEALTHY PRACTITIONERS AND TIGHTLY MATCHED CONTROLS (N = 12, AGE 65). SECOND, THESE MICROARRAY RESULTS WERE VERIFIED ON A SUBSET OF GENES USING QUANTITATIVE POLYMERASE CHAIN REACTION (QPCR) AND WERE VALIDATED USING QPCR IN LARGER TM AND CONTROL GROUPS (N = 45, AGE 63). BIOINFORMATICS INVESTIGATION EMPLOYED INGENUITY((R)) PATHWAY ANALYSIS (IPA((R))), DAVID, GENOMATIX, AND R PACKAGES. RESULTS: THE 200 GENES AND LOCI FOUND TO MEET STRICT CRITERIA FOR DIFFERENTIAL EXPRESSION IN THE MICROARRAY EXPERIMENT SHOWED CONTRASTING PATTERNS OF EXPRESSION THAT DISTINGUISHED THE TWO GROUPS. DIFFERENTIAL EXPRESSION RELATING TO IMMUNE FUNCTION AND ENERGY EFFICIENCY WERE MOST APPARENT. IN THE TM GROUP, RELATIVE TO THE CONTROL, ALL 49 GENES ASSOCIATED WITH INFLAMMATION WERE DOWNREGULATED, WHILE GENES ASSOCIATED WITH ANTIVIRAL AND ANTIBODY COMPONENTS OF THE DEFENSE RESPONSE WERE UPREGULATED. THE LARGEST EXPRESSION DIFFERENCES WERE SHOWN BY SIX GENES RELATED TO ERYTHROCYTE FUNCTION THAT APPEARED TO REFLECT A CONDITION OF LOWER ENERGY EFFICIENCY IN THE CONTROL GROUP. RESULTS SUPPORTING THESE GENE EXPRESSION DIFFERENCES WERE OBTAINED WITH QPCR-MEASURED EXPRESSION BOTH IN THE WELL-MATCHED MICROARRAY GROUPS AND IN THE LARGER, LESS WELL-MATCHED GROUPS. CONCLUSIONS: THESE FINDINGS ARE CONSISTENT WITH PREDICTIONS BASED ON RESULTS FROM EARLIER RANDOMIZED TRIALS OF MEDITATION AND MAY PROVIDE EVIDENCE FOR STRESS-RELATED MOLECULAR MECHANISMS UNDERLYING REDUCTIONS IN ANXIETY, POST-TRAUMATIC STRESS DISORDER (PTSD), CARDIOVASCULAR DISEASE (CVD), AND OTHER CHRONIC DISORDERS AND DISEASES. 2021 18 519 28 ASSOCIATIONS BETWEEN GENETIC AND EPIGENETIC VARIATIONS IN CYTOKINE GENES AND MILD PERSISTENT BREAST PAIN IN WOMEN FOLLOWING BREAST CANCER SURGERY. PERSISTENT PAIN FOLLOWING BREAST CANCER SURGERY IS A SIGNIFICANT PROBLEM. BOTH INHERITED AND ACQUIRED MECHANISMS OF INFLAMMATION APPEAR TO PLAY A ROLE IN THE DEVELOPMENT AND MAINTENANCE OF PERSISTENT PAIN. IN THIS LONGITUDINAL STUDY, GROWTH MIXTURE MODELING WAS USED TO IDENTIFY PERSISTENT BREAST PAIN PHENOTYPES BASED ON PAIN ASSESSMENTS OBTAINED PRIOR TO AND MONTHLY FOR 6MONTHS FOLLOWING BREAST CANCER SURGERY. ASSOCIATIONS BETWEEN THE "NO PAIN" AND "MILD PAIN" PHENOTYPES AND SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS) SPANNING 15 CYTOKINE GENES WERE EVALUATED. THE METHYLATION STATUS OF THE CPG SITES FOUND IN THE PROMOTERS OF GENES ASSOCIATED WITH PAIN GROUP MEMBERSHIP WAS DETERMINED USING BISULFITE SEQUENCING. IN THE MULTIVARIATE ANALYSIS, THREE SNPS (I.E., INTERLEUKIN 6 (IL6) RS2069840, C-X-C MOTIF CHEMOKINE LIGAND 8 (CXCL8) RS4073, TUMOR NECROSIS FACTOR (TNF) RS1800610) AND TWO TNF CPG SITES (I.E., C.-350C, C.-344C) WERE ASSOCIATED WITH PAIN GROUP MEMBERSHIP. THESE FINDINGS SUGGEST THAT VARIATIONS IN IL6, CXCL8, AND TNF ARE ASSOCIATED WITH THE DEVELOPMENT AND MAINTENANCE OF MILD PERSISTENT BREAST PAIN. CPG METHYLATION WITHIN THE TNF PROMOTER MAY PROVIDE AN ADDITIONAL MECHANISM THROUGH WHICH TNF ALTERS THE RISK FOR MILD PERSISTENT BREAST PAIN AFTER BREAST CANCER SURGERY. THESE GENETIC AND EPIGENETIC VARIATIONS MAY HELP TO IDENTIFY INDIVIDUALS WHO ARE PREDISPOSED TO THE DEVELOPMENT OF MILD LEVELS OF PERSISTENT BREAST PAIN FOLLOWING BREAST CANCER SURGERY. 2017 19 5957 34 TELOMERE LENGTH AND EPIGENETIC AGE ACCELERATION IN ADOLESCENTS WITH ANXIETY DISORDERS. EVIDENCE ON THE RELATIONSHIP BETWEEN GENETICS AND MENTAL HEALTH ARE FLOURISHING. HOWEVER, FEW STUDIES ARE EVALUATING EARLY BIOMARKERS THAT MIGHT LINK GENES, ENVIRONMENT, AND PSYCHOPATHOLOGY. WE AIMED TO STUDY TELOMERE LENGTH (TL) AND EPIGENETIC AGE ACCELERATION (AA) IN A COHORT OF ADOLESCENTS WITH AND WITHOUT ANXIETY DISORDERS (N = 234). WE EVALUATED A REPRESENTATIVE SUBSAMPLE OF PARTICIPANTS AT BASELINE AND AFTER 5 YEARS (N = 76) AND CATEGORIZED THEM ACCORDING TO THEIR ANXIETY DISORDER DIAGNOSIS AT BOTH TIME POINTS: (1) CONTROL GROUP (NO ANXIETY DISORDER, N = 18), (2) VARIABLE GROUP (ANXIETY DISORDER IN ONE EVALUATION, N = 38), AND (3) PERSISTENT GROUP (ANXIETY DISORDER AT BOTH TIME POINTS, N = 20). WE ASSESSED RELATIVE MEAN TL BY REAL-TIME QUANTITATIVE PCR AND DNA METHYLATION BY INFINIUM HUMANMETHYLATION450 BEADCHIP. WE CALCULATED AA USING THE HORVATH AGE ESTIMATION ALGORITHM AND ANALYZED DIFFERENCES AMONG GROUPS USING GENERALIZED LINEAR MIXED MODELS. THE PERSISTENT GROUP OF ANXIETY DISORDER DID NOT CHANGE TL OVER TIME (P = 0.495). THE VARIABLE GROUP HAD HIGHER BASELINE TL (P = 0.003) BUT NO ACCELERATED TL EROSION IN COMPARISON TO THE NON-ANXIETY CONTROL GROUP (P = 0.053). FURTHERMORE, THERE WERE NO DIFFERENCES IN AA AMONG GROUPS OVER TIME. OUR FINDINGS SUGGEST THAT ADOLESCENTS WITH CHRONIC ANXIETY DID NOT CHANGE TELOMERE LENGTH OVER TIME, WHICH COULD BE RELATED TO A DELAY IN NEURONAL DEVELOPMENT IN THIS PERIOD OF LIFE. 2021 20 976 32 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