1 577 143 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 2 344 42 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 3 1537 34 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 4 524 42 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 5 381 41 AN EPIGENOME-WIDE ASSOCIATION STUDY OF EARLY-ONSET MAJOR DEPRESSION IN MONOZYGOTIC TWINS. MAJOR DEPRESSION (MD) IS A DEBILITATING MENTAL HEALTH CONDITION WITH PEAK PREVALENCE OCCURRING EARLY IN LIFE. GENOME-WIDE EXAMINATION OF DNA METHYLATION (DNAM) OFFERS AN ATTRACTIVE COMPLEMENT TO STUDIES OF ALLELIC RISK GIVEN IT CAN REFLECT THE COMBINED INFLUENCE OF GENES AND ENVIRONMENT. THE CURRENT STUDY USED MONOZYGOTIC TWINS TO IDENTIFY DIFFERENTIALLY AND VARIABLY METHYLATED REGIONS OF THE GENOME THAT DISTINGUISH TWINS WITH AND WITHOUT A LIFETIME HISTORY OF EARLY-ONSET MD. THE SAMPLE INCLUDED 150 CAUCASIAN MONOZYGOTIC TWINS BETWEEN THE AGES OF 15 AND 20 (73% FEMALE; MAGE = 17.52 SD = 1.28) WHO WERE ASSESSED DURING A DEVELOPMENTAL STAGE CHARACTERIZED BY RELATIVELY DISTINCT NEUROPHYSIOLOGICAL CHANGES. ALL TWINS WERE GENERALLY HEALTHY AND CURRENTLY FREE OF MEDICATIONS WITH PSYCHOTROPIC EFFECTS. DNAM WAS MEASURED IN PERIPHERAL BLOOD CELLS USING THE INFINIUM HUMAN BEADCHIP 450 K ARRAY. MD ASSOCIATIONS WITH EARLY-ONSET MD WERE DETECTED AT 760 DIFFERENTIALLY AND VARIABLY METHYLATED PROBES/REGIONS THAT MAPPED TO 428 GENES. GENES AND GENOMIC REGIONS INVOLVED NEURAL CIRCUITRY FORMATION, PROJECTION, FUNCTIONING, AND PLASTICITY. GENE ENRICHMENT ANALYSES IMPLICATED GENES RELATED TO NEURON STRUCTURES AND NEURODEVELOPMENTAL PROCESSES INCLUDING CELL-CELL ADHESION GENES (E.G., PCDHA GENES). GENES PREVIOUSLY IMPLICATED IN MOOD AND PSYCHIATRIC DISORDERS AS WELL AS CHRONIC STRESS (E.G., NRG3) ALSO WERE IDENTIFIED. DNAM REGIONS ASSOCIATED WITH EARLY-ONSET MD WERE FOUND TO OVERLAP GENETIC LOCI IDENTIFIED IN THE LATEST PSYCHIATRIC GENOMICS CONSORTIUM META-ANALYSIS OF DEPRESSION. UNDERSTANDING THE TIME COURSE OF EPIGENETIC INFLUENCES DURING EMERGING ADULTHOOD MAY CLARIFY DEVELOPMENTAL PHASES WHERE CHANGES IN THE DNA METHYLOME MAY MODULATE INDIVIDUAL DIFFERENCES IN MD RISK. 2020 6 67 46 A LONGITUDINAL STUDY OF THE ASSOCIATIONS OF BDNF GENOTYPE AND METHYLATION WITH POSTSTROKE ANXIETY. BACKGROUND: ALTHOUGH THE PRECISE ETIOLOGY OF POSTSTROKE ANXIETY (PSA) HAS YET TO BE FULLY ELUCIDATED, IT IS KNOWN THAT BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) IS IMPORTANT FOR NEURAL PLASTICITY AND LONG-TERM POTENTIATION, ASSOCIATED WITH THE PATHOPHYSIOLOGY OF ANXIETY. THE EXPRESSION OF BDNF IS REGULATED BY EPIGENETIC AND GENETIC PROFILES. THUS, WE INVESTIGATED THE ASSOCIATION BETWEEN BDNF METHYLATION STATUS AND PSA AT 2 WEEKS AND 1 YEAR AFTER STROKE WHILE ACCOUNTING FOR INTERACTIONS WITH THE BDNF VAL66MET POLYMORPHISM. METHODS: THE BASELINE SAMPLE COMPRISED 286 PATIENTS WHO WERE ASSESSED AT 2 WEEKS AFTER STROKE; OF THESE PATIENTS, 222 (78%) WERE FOLLOWED UP WITH AT 1 YEAR AFTER STROKE. THE PRESENCE OF PSA WAS DETERMINED USING THE ANXIETY SUBSCALE OF THE HOSPITAL ANXIETY AND DEPRESSION SCALE (HADS), AND THE EFFECTS OF BDNF METHYLATION STATUS AND POLYMORPHISMS ON PSA STATUS WERE ASSESSED WITH MULTIVARIATE LOGISTIC REGRESSION MODELS. RESULTS: THE PREVALENCE OF PSA WAS SLIGHTLY LOWER (27 [9.4%]) AT BASELINE, AND 35 (15.8%) PATIENTS WERE IDENTIFIED AS HAVING PSA AT THE 1-YEAR FOLLOW-UP. STROKE PATIENTS WITH A HIGHER AVERAGE METHYLATION STATUS WERE MORE LIKELY TO HAVE PSA AT 1 YEAR. THE BDNF VAL66MET POLYMORPHISM WAS NOT INDEPENDENTLY ASSOCIATED WITH PSA DURING EITHER THE ACUTE OR CHRONIC PHASE AFTER STROKE, BUT THERE WAS A SIGNIFICANT INTERACTIVE EFFECT BETWEEN BDNF METHYLATION AND GENOTYPE ON PSA AT 2 WEEKS. CONCLUSIONS: IN THIS STUDY, BDNF METHYLATION IN COMBINATION WITH THE MET/MET BDNF POLYMORPHISM (VAL66MET POLYMORPHISM) WAS ASSOCIATED WITH PSA. THESE FINDINGS MAY HELP IDENTIFY PATIENTS AT HIGHER RISK FOR PSA. 2019 7 2079 36 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 8 990 36 CHRONIC SOCIAL STRESS INDUCES DNA METHYLATION CHANGES AT AN EVOLUTIONARY CONSERVED INTERGENIC REGION IN CHROMOSOME X. CHRONIC STRESS RESULTING FROM PROLONGED EXPOSURE TO NEGATIVE LIFE EVENTS INCREASES THE RISK OF MOOD AND ANXIETY DISORDERS. ALTHOUGH CHRONIC STRESS CAN CHANGE GENE EXPRESSION RELEVANT FOR BEHAVIOR, MOLECULAR REGULATORS OF THIS CHANGE HAVE NOT BEEN FULLY DETERMINED. ONE PROCESS THAT COULD PLAY A ROLE IS DNA METHYLATION, AN EPIGENETIC PROCESS WHEREBY A METHYL GROUP IS ADDED ONTO NUCLEOTIDES, PREDOMINANTLY CYTOSINE IN THE CPG CONTEXT, AND WHICH CAN BE INDUCED BY CHRONIC STRESS. IT IS UNKNOWN TO WHAT EXTENT CHRONIC SOCIAL DEFEAT, A MODEL OF HUMAN SOCIAL STRESS, INFLUENCES DNA METHYLATION PATTERNS ACROSS THE GENOME. OUR STUDY ADDRESSED THIS QUESTION BY USING A TARGETED-CAPTURE APPROACH CALLED METHYL-SEQ TO INVESTIGATE DNA METHYLATION PATTERNS OF THE DENTATE GYRUS AT PUTATIVE REGULATORY REGIONS ACROSS THE MOUSE GENOME FROM MICE EXPOSED TO 14 DAYS OF SOCIAL DEFEAT. FINDINGS WERE REPLICATED IN INDEPENDENT COHORTS BY BISULFITE-PYROSEQUENCING. TWO DIFFERENTIALLY METHYLATED REGIONS (DMRS) WERE IDENTIFIED. ONE DMR WAS LOCATED AT INTRON 9 OF DROSHA, AND IT SHOWED REDUCED METHYLATION IN STRESSED MICE. THIS OBSERVATION REPLICATED IN ONE OF TWO INDEPENDENT COHORTS. A SECOND DMR WAS IDENTIFIED AT AN INTERGENIC REGION OF CHROMOSOME X, AND METHYLATION IN THIS REGION WAS INCREASED IN STRESSED MICE. THIS METHYLATION DIFFERENCE REPLICATED IN TWO INDEPENDENT COHORTS AND IN MAJOR DEPRESSIVE DISORDER (MDD) POSTMORTEM BRAINS. THESE RESULTS HIGHLIGHT A REGION NOT PREVIOUSLY KNOWN TO BE DIFFERENTIALLY METHYLATED BY CHRONIC SOCIAL DEFEAT STRESS AND WHICH MAY BE INVOLVED IN MDD. 2018 9 3077 31 GENOME-WIDE METHYL-SEQ ANALYSIS OF BLOOD-BRAIN TARGETS OF GLUCOCORTICOID EXPOSURE. CHRONIC EXPOSURE TO GLUCOCORTICOIDS (GCS) CAN LEAD TO PSYCHIATRIC COMPLICATIONS THROUGH EPIGENETIC MECHANISMS SUCH AS DNA METHYLATION (DNAM). WE SOUGHT TO DETERMINE WHETHER EPIGENETIC CHANGES IN A PERIPHERAL TISSUE CAN SERVE AS A SURROGATE FOR THOSE IN A RELATIVELY INACCESSIBLE TISSUE SUCH AS THE BRAIN. DNA EXTRACTED FROM THE HIPPOCAMPUS AND BLOOD OF MICE TREATED WITH GCS OR VEHICLE SOLUTION WAS ASSAYED USING A GENOME-WIDE DNAM PLATFORM (METHYL-SEQ) TO IDENTIFY DIFFERENTIALLY METHYLATED REGIONS (DMRS) INDUCED BY GC TREATMENT. WE OBSERVED THAT APPROXIMATELY 70% OF THE DMRS IN BOTH TISSUES LOST METHYLATION FOLLOWING GC TREATMENT. OF THE 3,095 DMRS THAT MAPPED TO THE SAME GENES IN BOTH TISSUES, 1,853 DMRS UNDERWENT DNAM CHANGES IN THE SAME DIRECTION. INTERESTINGLY, ONLY 209 DMRS (<7%) OVERLAPPED IN GENOMIC COORDINATES BETWEEN THE 2 TISSUES, SUGGESTING TISSUE-SPECIFIC DIFFERENCES IN GC-TARGETED LOCI. PATHWAY ANALYSIS SHOWED THAT THE DMR-ASSOCIATED GENES WERE MEMBERS OF PATHWAYS INVOLVED IN METABOLISM, IMMUNE FUNCTION, AND NEURODEVELOPMENT. ALSO, CHANGES IN CELL TYPE COMPOSITION OF BLOOD AND BRAIN WERE EXAMINED BY FLUORESCENCE-ACTIVATED CELL SORTING. SEPARATION OF THE CORTEX INTO NEURONAL AND NON-NEURONAL FRACTIONS AND THE LEUKOCYTES INTO T-CELLS, B-CELLS, AND NEUTROPHILS SHOWED THAT GC-INDUCED METHYLATION CHANGES PRIMARILY OCCURRED IN NEURONS AND T-CELLS, WITH THE BLOOD TISSUE ALSO UNDERGOING A SHIFT IN THE PROPORTION OF CONSTITUENT CELL TYPES WHILE THE PROPORTION OF NEURONS AND GLIA IN THE BRAIN REMAINED STABLE. FROM THE CURRENT PILOT STUDY, WE FOUND THAT DESPITE TISSUE-SPECIFIC EPIGENETIC CHANGES AND CELLULAR HETEROGENEITY, BLOOD CAN SERVE AS A SURROGATE FOR GC-INDUCED CHANGES IN THE BRAIN. 2017 10 3652 30 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 11 1345 33 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 12 6311 34 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 13 3914 32 LIFETIME STRESS ACCELERATES EPIGENETIC AGING IN AN URBAN, AFRICAN AMERICAN COHORT: RELEVANCE OF GLUCOCORTICOID SIGNALING. BACKGROUND: CHRONIC PSYCHOLOGICAL STRESS IS ASSOCIATED WITH ACCELERATED AGING AND INCREASED RISK FOR AGING-RELATED DISEASES, BUT THE UNDERLYING MOLECULAR MECHANISMS ARE UNCLEAR. RESULTS: WE EXAMINED THE EFFECT OF LIFETIME STRESSORS ON A DNA METHYLATION-BASED AGE PREDICTOR, EPIGENETIC CLOCK. AFTER CONTROLLING FOR BLOOD CELL-TYPE COMPOSITION AND LIFESTYLE PARAMETERS, CUMULATIVE LIFETIME STRESS, BUT NOT CHILDHOOD MALTREATMENT OR CURRENT STRESS ALONE, PREDICTED ACCELERATED EPIGENETIC AGING IN AN URBAN, AFRICAN AMERICAN COHORT (N = 392). THIS EFFECT WAS PRIMARILY DRIVEN BY PERSONAL LIFE STRESSORS, WAS MORE PRONOUNCED WITH ADVANCING AGE, AND WAS BLUNTED IN INDIVIDUALS WITH HIGHER CHILDHOOD ABUSE EXPOSURE. HYPOTHESIZING THAT THESE EPIGENETIC EFFECTS COULD BE MEDIATED BY GLUCOCORTICOID SIGNALING, WE FOUND THAT A HIGH NUMBER (N = 85) OF EPIGENETIC CLOCK CPG SITES WERE LOCATED WITHIN GLUCOCORTICOID RESPONSE ELEMENTS. WE FURTHER EXAMINED THE FUNCTIONAL EFFECTS OF GLUCOCORTICOIDS ON EPIGENETIC CLOCK CPGS IN AN INDEPENDENT SAMPLE WITH GENOME-WIDE DNA METHYLATION (N = 124) AND GENE EXPRESSION DATA (N = 297) BEFORE AND AFTER EXPOSURE TO THE GLUCOCORTICOID RECEPTOR AGONIST DEXAMETHASONE. DEXAMETHASONE INDUCED DYNAMIC CHANGES IN METHYLATION IN 31.2 % (110/353) OF THESE CPGS AND TRANSCRIPTION IN 81.7 % (139/170) OF GENES NEIGHBORING EPIGENETIC CLOCK CPGS. DISEASE ENRICHMENT ANALYSIS OF THESE DEXAMETHASONE-REGULATED GENES SHOWED ENRICHED ASSOCIATION FOR AGING-RELATED DISEASES, INCLUDING CORONARY ARTERY DISEASE, ARTERIOSCLEROSIS, AND LEUKEMIAS. CONCLUSIONS: CUMULATIVE LIFETIME STRESS MAY ACCELERATE EPIGENETIC AGING, AN EFFECT THAT COULD BE DRIVEN BY GLUCOCORTICOID-INDUCED EPIGENETIC CHANGES. THESE FINDINGS CONTRIBUTE TO OUR UNDERSTANDING OF MECHANISMS LINKING CHRONIC STRESS WITH ACCELERATED AGING AND HEIGHTENED DISEASE RISK. 2015 14 6547 33 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 15 1436 28 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 16 1503 36 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 17 3080 36 GENOME-WIDE METHYLATION IN ALCOHOL USE DISORDER SUBJECTS: IMPLICATIONS FOR AN EPIGENETIC REGULATION OF THE CORTICO-LIMBIC GLUCOCORTICOID RECEPTORS (NR3C1). ENVIRONMENTAL FACTORS, INCLUDING SUBSTANCE ABUSE AND STRESS, CAUSE LONG-LASTING CHANGES IN THE REGULATION OF GENE EXPRESSION IN THE BRAIN VIA EPIGENETIC MECHANISMS, SUCH AS DNA METHYLATION. WE EXAMINED GENOME-WIDE DNA METHYLATION PATTERNS IN THE PREFRONTAL CORTEX (PFC, BA10) OF 25 PAIRS OF CONTROL AND INDIVIDUALS WITH ALCOHOL USE DISORDER (AUD), USING THE INFINIUM((R)) METHYLATIONEPIC BEADCHIP. WE IDENTIFIED 5254 DIFFERENTIALLY METHYLATED CPGS (P(NOMINAL) < 0.005). BIOINFORMATIC ANALYSES HIGHLIGHTED BIOLOGICAL PROCESSES CONTAINING GENES RELATED TO STRESS ADAPTATION, INCLUDING THE GLUCOCORTICOID RECEPTOR (ENCODED BY NR3C1). CONSIDERING THAT ALCOHOL IS A STRESSOR, WE FOCUSED OUR ATTENTION ON DIFFERENTIALLY METHYLATED REGIONS OF THE NR3C1 GENE AND VALIDATED THE DIFFERENTIAL METHYLATION OF SEVERAL GENES IN THE NR3C1 NETWORK. CHRONIC ALCOHOL DRINKING RESULTS IN A SIGNIFICANT INCREASED METHYLATION OF THE NR3C1 EXON VARIANT 1(H), WITH A PARTICULAR INCREASE IN THE LEVELS OF 5-HYDROXYMETHYLCYTOSINE OVER 5-METHYLCYTOSINE. THESE CHANGES IN DNA METHYLATION WERE ASSOCIATED WITH REDUCED NR3C1 MRNA AND PROTEIN EXPRESSION LEVELS IN PFC, AS WELL AS OTHER CORTICO-LIMBIC REGIONS OF AUD SUBJECTS WHEN COMPARED WITH CONTROLS. FURTHERMORE, WE SHOW THAT THE EXPRESSION OF SEVERAL STRESS-RESPONSIVE GENES (E.G., CRF, POMC, AND FKBP5) IS ALTERED IN THE PFC OF AUD SUBJECTS. THESE STRESS-RESPONSE GENES WERE ALSO CHANGED IN THE HIPPOCAMPUS, A REGION THAT IS HIGHLY SUSCEPTIBLE TO STRESS. THESE DATA SUGGEST THAT ALCOHOL-DEPENDENT ABERRANT DNA METHYLATION OF NR3C1 AND CONSEQUENT CHANGES IN OTHER STRESS-RELATED GENES MIGHT BE FUNDAMENTAL IN THE PATHOPHYSIOLOGY OF AUD AND LAY THE GROUNDWORK FOR TREATMENTS TARGETING THE EPIGENETIC MECHANISMS REGULATING NR3C1 IN AUD. 2021 18 1967 41 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 2625 34 EPIGENOME-WIDE ASSOCIATION STUDY AND MULTI-TISSUE REPLICATION OF INDIVIDUALS WITH ALCOHOL USE DISORDER: EVIDENCE FOR ABNORMAL GLUCOCORTICOID SIGNALING PATHWAY GENE REGULATION. ALCOHOL USE DISORDER (AUD) IS A CHRONIC DEBILITATING DISORDER WITH LIMITED TREATMENT OPTIONS AND POORLY DEFINED PATHOPHYSIOLOGY. THERE ARE SUBSTANTIAL GENETIC AND EPIGENETIC COMPONENTS; HOWEVER, THE UNDERLYING MECHANISMS CONTRIBUTING TO AUD REMAIN LARGELY UNKNOWN. WE CONDUCTED THE LARGEST DNA METHYLATION EPIGENOME-WIDE ASSOCIATION STUDY (EWAS) ANALYSES CURRENTLY AVAILABLE FOR AUD (TOTAL N = 625) AND EMPLOYED A TOP HIT REPLICATION (N = 4798) USING A CROSS-TISSUE/CROSS-PHENOTYPIC APPROACH WITH THE GOAL OF IDENTIFYING NOVEL EPIGENETIC TARGETS RELEVANT TO AUD. RESULTS SHOW THAT A NETWORK OF DIFFERENTIALLY METHYLATED REGIONS IN GLUCOCORTICOID SIGNALING AND INFLAMMATION-RELATED GENES WERE ASSOCIATED WITH ALCOHOL USE BEHAVIORS. A TOP PROBE CONSISTENTLY ASSOCIATED ACROSS ALL COHORTS WAS LOCATED IN THE LONG NON-CODING RNA GROWTH ARREST SPECIFIC FIVE GENE (GAS5) (P < 10(-24)). GAS5 HAS BEEN IMPLICATED IN REGULATING TRANSCRIPTIONAL ACTIVITY OF THE GLUCOCORTICOID RECEPTOR AND HAS MULTIPLE FUNCTIONS RELATED TO APOPTOSIS, IMMUNE FUNCTION AND VARIOUS CANCERS. ENDOPHENOTYPIC ANALYSES USING PERIPHERAL CORTISOL LEVELS AND NEUROIMAGING PARADIGMS SHOWED THAT METHYLOMIC VARIATION IN GAS5 NETWORK-RELATED PROBES WERE ASSOCIATED WITH STRESS PHENOTYPES. POSTMORTEM BRAIN ANALYSES DOCUMENTED INCREASED GAS5 EXPRESSION IN THE AMYGDALA OF INDIVIDUALS WITH AUD. OUR DATA SUGGEST THAT ALCOHOL USE IS ASSOCIATED WITH DIFFERENTIAL METHYLATION IN THE GLUCOCORTICOID SYSTEM THAT MIGHT INFLUENCE STRESS AND INFLAMMATORY REACTIVITY AND SUBSEQUENTLY RISK FOR AUD. 2021 20 1497 33 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