1  502 166 ASSOCIATION OF ARSENIC EXPOSURE WITH WHOLE BLOOD DNA METHYLATION: AN EPIGENOME-WIDE STUDY OF BANGLADESHI ADULTS. BACKGROUND: ARSENIC EXPOSURE AFFECTS [FORMULA: SEE TEXT] PEOPLE WORLDWIDE, INCLUDING [FORMULA: SEE TEXT] IN BANGLADESH. ARSENIC EXPOSURE INCREASES THE RISK OF CANCER AND OTHER CHRONIC DISEASES, AND ONE POTENTIAL MECHANISM OF ARSENIC TOXICITY IS EPIGENETIC DYSREGULATION. OBJECTIVE: WE ASSESSED ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND GENOME-WIDE DNA METHYLATION MEASURED AT BASELINE AMONG 396 BANGLADESHI ADULTS PARTICIPATING IN THE HEALTH EFFECTS OF ARSENIC LONGITUDINAL STUDY (HEALS) WHO WERE EXPOSED BY DRINKING NATURALLY CONTAMINATED WELL WATER. METHODS: METHYLATION IN WHOLE BLOOD DNA WAS MEASURED AT [FORMULA: SEE TEXT] USING THE ILLUMINA INFINIUMMETHYLATIONEPIC (EPIC) ARRAY. TO ASSESS ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND CPG METHYLATION, WE USED LINEAR REGRESSION MODELS ADJUSTED FOR COVARIATES AND SURROGATE VARIABLES (SVS) (CAPTURING UNKNOWN TECHNICAL AND BIOLOGIC FACTORS). WE ATTEMPTED REPLICATION AND CONDUCTED A META-ANALYSIS USING AN INDEPENDENT DATASET OF [FORMULA: SEE TEXT] FROM 400 BANGLADESHI INDIVIDUALS WITH ARSENICAL SKIN LESIONS. RESULTS: WE IDENTIFIED 34 CPGS ASSOCIATED WITH [FORMULA: SEE TEXT] CREATININE-ADJUSTED URINARY ARSENIC [[FORMULA: SEE TEXT]]. SIXTEEN OF THESE CPGS ANNOTATED TO THE [FORMULA: SEE TEXT] ARRAY, AND 10 ASSOCIATIONS WERE REPLICATED ([FORMULA: SEE TEXT]). THE TOP TWO CPGS ANNOTATED UPSTREAM OF THE ABR GENE (CG01912040, CG10003262 ). ALL URINARY ARSENIC-ASSOCIATED CPGS WERE ALSO ASSOCIATED WITH ARSENIC CONCENTRATION MEASURED IN DRINKING WATER ([FORMULA: SEE TEXT]). META-ANALYSIS ([FORMULA: SEE TEXT] SAMPLES) IDENTIFIED 221 URINARY ARSENIC-ASSOCIATED CPGS ([FORMULA: SEE TEXT]). THE ARSENIC-ASSOCIATED CPGS FROM THE META-ANALYSIS WERE ENRICHED IN NON-CPG ISLANDS AND SHORES ([FORMULA: SEE TEXT]) AND DEPLETED IN PROMOTER REGIONS ([FORMULA: SEE TEXT]). AMONG THE ARSENIC-ASSOCIATED CPGS ([FORMULA: SEE TEXT]), WE OBSERVED SIGNIFICANT ENRICHMENT OF GENES ANNOTATING TO THE REACTIVE OXYGEN SPECIES PATHWAY, INFLAMMATORY RESPONSE, AND TUMOR NECROSIS FACTOR [FORMULA: SEE TEXT] ([FORMULA: SEE TEXT]) SIGNALING VIA NUCLEAR FACTOR KAPPA-B ([FORMULA: SEE TEXT]) HALLMARKS ([FORMULA: SEE TEXT]). CONCLUSIONS: THE NOVEL AND REPLICABLE ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND DNA METHYLATION AT SPECIFIC CPGS OBSERVED IN THIS WORK SUGGEST THAT EPIGENETIC ALTERATIONS SHOULD BE FURTHER INVESTIGATED AS POTENTIAL MEDIATORS IN ARSENIC TOXICITY AND AS BIOMARKERS OF EXPOSURE AND EFFECT IN EXPOSED POPULATIONS. HTTPS://DOI.ORG/10.1289/EHP3849.	2019	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
2  490  61 ASSESSING THE IMPACT OF ARSENIC METABOLISM EFFICIENCY ON DNA METHYLATION USING MENDELIAN RANDOMIZATION. BACKGROUND: ARSENIC EXPOSURE AFFECTS >100 MILLION PEOPLE GLOBALLY AND INCREASES RISK FOR CHRONIC DISEASES. ONE POSSIBLE TOXICITY MECHANISM IS EPIGENETIC MODIFICATION. PREVIOUS EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) HAVE IDENTIFIED ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND CPG-SPECIFIC DNA METHYLATION. TO PROVIDE ADDITIONAL EVIDENCE THAT OBSERVED ASSOCIATIONS REPRESENT CAUSAL RELATIONSHIPS, WE EXAMINE THE ASSOCIATION BETWEEN GENETIC DETERMINANTS OF ARSENIC METABOLISM EFFICIENCY (PERCENT DIMETHYLARSINIC ACID, DMA%, IN URINE) AND DNA METHYLATION AMONG INDIVIDUALS FROM THE HEALTH EFFECTS OF ARSENIC LONGITUDINAL STUDY (N = 379) AND BANGLADESH VITAMIN E AND SELENIUM TRIAL (N = 393). METHODS: WE USED MULTIVARIATE LINEAR MODELS TO ASSESS THE ASSOCIATION OF METHYLATION AT 221 ARSENIC-ASSOCIATED CPGS WITH DMA% AND MEASURES OF GENETICALLY PREDICTED DMA% DERIVED FROM THREE SNPS (RS9527, RS11191527, AND RS61735836). WE ALSO CONDUCTED TWO-SAMPLE MENDELIAN RANDOMIZATION ANALYSES TO ESTIMATE THE ASSOCIATION BETWEEN ARSENIC METABOLISM EFFICIENCY AND CPG METHYLATION. RESULTS: AMONG THE ASSOCIATIONS BETWEEN DMA% AND METHYLATION AT EACH OF 221 CPGS, 64% WERE DIRECTIONALLY CONSISTENT WITH ASSOCIATIONS OBSERVED BETWEEN ARSENIC EXPOSURE AND THE 221 CPGS FROM A PRIOR EWAS. SIMILARLY, AMONG THE ASSOCIATIONS BETWEEN GENETICALLY PREDICTED DMA% AND EACH CPG, 62% WERE DIRECTIONALLY CONSISTENT WITH THE PRIOR EWAS RESULTS. TWO-SAMPLE MENDELIAN RANDOMIZATION ANALYSES PRODUCED SIMILAR CONCLUSIONS. CONCLUSION: OUR FINDINGS SUPPORT THE HYPOTHESIS THAT ARSENIC EXPOSURE EFFECTS DNA METHYLATION AT SPECIFIC CPGS IN WHOLE BLOOD. OUR NOVEL APPROACH FOR ASSESSING THE IMPACT OF ARSENIC EXPOSURE ON DNA METHYLATION REQUIRES LARGER SAMPLES IN ORDER TO DRAW MORE ROBUST CONCLUSIONS FOR SPECIFIC CPG SITES.	2020	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
3 3951  65 LOCUS-SPECIFIC DIFFERENTIAL DNA METHYLATION AND URINARY ARSENIC: AN EPIGENOME-WIDE ASSOCIATION STUDY IN BLOOD AMONG ADULTS WITH LOW-TO-MODERATE ARSENIC EXPOSURE. BACKGROUND: CHRONIC EXPOSURE TO ARSENIC (AS), A HUMAN TOXICANT AND CARCINOGEN, REMAINS A GLOBAL PUBLIC HEALTH PROBLEM. HEALTH RISKS PERSIST AFTER AS EXPOSURE HAS ENDED, SUGGESTING EPIGENETIC DYSREGULATION AS A MECHANISTIC LINK BETWEEN EXPOSURE AND HEALTH OUTCOMES. OBJECTIVES: WE INVESTIGATED THE ASSOCIATION BETWEEN TOTAL URINARY AS AND LOCUS-SPECIFIC DNA METHYLATION IN THE STRONG HEART STUDY, A COHORT OF AMERICAN INDIAN ADULTS WITH LOW-TO-MODERATE AS EXPOSURE [TOTAL URINARY AS, MEAN (+/-SD) MUG/G CREATININE: 11.7 (10.6)]. METHODS: DNA METHYLATION WAS MEASURED IN 2,325 PARTICIPANTS USING THE ILLUMINA METHYLATIONEPIC ARRAY. WE IMPLEMENTED LINEAR MODELS TO TEST DIFFERENTIALLY METHYLATED POSITIONS (DMPS) AND THE DMRCATE METHOD TO IDENTIFY REGIONS (DMRS) AND CONDUCTED GENE ONTOLOGY ENRICHMENT ANALYSIS. MODELS WERE ADJUSTED FOR ESTIMATED CELL TYPE PROPORTIONS, AGE, SEX, BODY MASS INDEX, SMOKING, EDUCATION, ESTIMATED GLOMERULAR FILTRATION RATE, AND STUDY CENTER. ARSENIC WAS MEASURED IN URINE AS THE SUM OF INORGANIC AND METHYLATED SPECIES. RESULTS: IN ADJUSTED MODELS, METHYLATION AT 20 CPGS WAS ASSOCIATED WITH URINARY AS AFTER FALSE DISCOVERY RATE (FDR) CORRECTION (FDR < 0.05). AFTER BONFERRONI CORRECTION, 5 CPGS REMAINED ASSOCIATED WITH TOTAL URINARY AS (PBONFERRONI < 0.05), LOCATED IN SLC7A11, ANKS3, LINGO3, CSNK1D, ADAMTSL4. WE IDENTIFIED ONE DMR ON CHROMOSOME 11 (CHR11:2,322,050-2,323,247), ANNOTATED TO C11ORF2; TSPAN32 GENES. DISCUSSION: THIS IS ONE OF THE FIRST EPIGENOME-WIDE ASSOCIATION STUDIES TO INVESTIGATE AS EXPOSURE AND LOCUS-SPECIFIC DNA METHYLATION USING THE ILLUMINA METHYLATIONEPIC ARRAY AND THE LARGEST EPIGENOME-WIDE STUDY OF AS EXPOSURE. THE TOP DMP WAS LOCATED IN SLC7A11A, A GENE INVOLVED IN CYSTINE/GLUTAMATE TRANSPORT AND THE BIOSYNTHESIS OF GLUTATHIONE, AN ANTIOXIDANT THAT MAY PROTECT AGAINST AS-INDUCED OXIDATIVE STRESS. ADDITIONAL DMPS WERE LOCATED IN GENES ASSOCIATED WITH TUMOR DEVELOPMENT AND GLUCOSE METABOLISM. FURTHER RESEARCH IS NEEDED, INCLUDING RESEARCH IN MORE DIVERSE POPULATIONS, TO INVESTIGATE WHETHER AS-RELATED DNA METHYLATION SIGNATURES ARE ASSOCIATED WITH GENE EXPRESSION OR MAY SERVE AS BIOMARKERS OF DISEASE DEVELOPMENT. HTTPS://DOI.ORG/10.1289/EHP6263.	2020	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              
4 2079  46 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 6311  41 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
6 2643  46 EPIGENOMIC ASSOCIATION ANALYSIS IDENTIFIES SMOKING-RELATED DNA METHYLATION SITES IN AFRICAN AMERICANS. CIGARETTE SMOKING IS AN ENVIRONMENTAL RISK FACTOR FOR MANY CHRONIC DISEASES, AND DISEASE RISK CAN OFTEN BE MANAGED BY SMOKING CONTROL. SMOKING CAN INDUCE CELLULAR AND MOLECULAR CHANGES, INCLUDING EPIGENETIC MODIFICATION, BUT THE SHORT- AND LONG-TERM EPIGENETIC MODIFICATIONS CAUSED BY CIGARETTE SMOKING AT THE GENE LEVEL HAVE NOT BEEN WELL UNDERSTOOD. RECENT STUDIES HAVE IDENTIFIED SMOKING-RELATED DNA METHYLATION (DNAM) SITES IN CAUCASIANS. TO DETERMINE WHETHER THE SAME DNAM SITES ASSOCIATE WITH SMOKING IN AFRICAN AMERICANS, AND TO IDENTIFY NOVEL SMOKING-RELATED DNAM SITES, WE CONDUCTED A METHYLOME-WIDE ASSOCIATION STUDY OF CIGARETTE SMOKING USING A DISCOVERY SAMPLE OF 972 AFRICAN AMERICANS, AND A REPLICATION SAMPLE OF 239 AFRICAN AMERICANS WITH TWO ARRAY-BASED METHODS. AMONG 15 DNAM SITES SIGNIFICANTLY ASSOCIATED WITH SMOKING AFTER CORRECTION FOR MULTIPLE TESTING IN OUR DISCOVERY SAMPLE, 5 DNAM SITES ARE REPLICATED IN AN INDEPENDENT COHORT, AND 14 SITES IN THE REPLICATION SAMPLE HAVE EFFECTS IN THE SAME DIRECTION AS IN THE DISCOVERY SAMPLE. THE TOP TWO SMOKING-RELATED DNAM SITES IN F2RL3 (FACTOR II RECEPTOR-LIKE 3) AND GPR15 (G-PROTEIN-COUPLED RECEPTOR 15) OBSERVED IN AFRICAN AMERICANS ARE CONSISTENT WITH PREVIOUS FINDINGS IN CAUCASIANS. THE ASSOCIATIONS BETWEEN THE REPLICATED DNAM SITES AND SMOKING REMAIN SIGNIFICANT AFTER ADJUSTING FOR GENETIC BACKGROUND. DESPITE THE DISTINCT GENETIC BACKGROUND BETWEEN AFRICAN AMERICANS AND CAUCASIANS, THE DNAM FROM THE TWO ETHNIC GROUPS SHARES COMMON ASSOCIATIONS WITH CIGARETTE SMOKING, WHICH SUGGESTS A COMMON MOLECULAR MECHANISM OF EPIGENETIC MODIFICATION INFLUENCED BY ENVIRONMENTAL EXPOSURE.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
7 5882  44 SYSTEMATIC REVIEW OF LUNG FUNCTION AND COPD WITH PERIPHERAL BLOOD DNA METHYLATION IN POPULATION BASED STUDIES. BACKGROUND: EPIGENETIC VARIATIONS IN PERIPHERAL BLOOD HAVE POTENTIAL AS BIOMARKERS FOR DISEASE. THIS SYSTEMATIC REVIEW ASSESSES THE ASSOCIATION OF LUNG FUNCTION AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) WITH DNA METHYLATION PROFILES IN PERIPHERAL BLOOD FROM POPULATION-BASED STUDIES. METHODS: ONLINE DATABASES MEDLINE, EMBASE, AND WEB OF SCIENCE WERE SEARCHED. GOOGLE SCHOLAR WAS SEARCHED TO IDENTIFY GREY LITERATURE. AFTER REMOVING DUPLICATE ARTICLES, 1155 ARTICLES WERE INDEPENDENTLY SCREENED BY TWO INVESTIGATORS. PEER REVIEWED REPORTS ON POPULATION-BASED STUDIES THAT EXAMINED PERIPHERAL BLOOD DNA METHYLATION IN PARTICIPANTS WITH MEASURED LUNG FUNCTION (FEV1, FEV1/FVC RATIO) OR KNOWN COPD STATUS WERE SELECTED FOR FULL-TEXT REVIEW. SIX ARTICLES WERE SUITABLE FOR INCLUSION. INFORMATION REGARDING STUDY CHARACTERISTICS, DESIGNS, METHODOLOGIES AND CONCLUSIONS WAS EXTRACTED. A NARRATIVE SYNTHESIS WAS PERFORMED BASED ON PUBLISHED RESULTS. RESULTS: THREE OF THE SIX ARTICLES ASSESSED THE ASSOCIATION OF COPD WITH DNA METHYLATION, AND TWO OF THESE ALSO INCLUDED ASSOCIATIONS WITH LUNG FUNCTION. OVERALL, FIVE REPORTS EXAMINED THE ASSOCIATION OF LUNG FUNCTION WITH DNA METHYLATION PROFILES. FIVE OF THE SIX ARTICLES REPORTED 'SIGNIFICANT' RESULTS. HOWEVER, NO CONSISTENT CPG SITES WERE IDENTIFIED ACROSS STUDIES FOR COPD STATUS OR LUNG FUNCTION VALUES. CONCLUSIONS: DNA METHYLATION PATTERNS IN PERIPHERAL BLOOD FROM INDIVIDUALS WITH REDUCED LUNG FUNCTION OR COPD MAY BE DIFFERENT TO THOSE IN PEOPLE WITH NORMAL LUNG FUNCTION. HOWEVER, THIS SYSTEMATIC REVIEW DID NOT FIND ANY CONSISTENT ASSOCIATIONS OF LUNG FUNCTION OR COPD WITH DIFFERENTIALLY METHYLATED CPG SITES. LARGE STUDIES WITH A LONGITUDINAL DESIGN TO ADDRESS REVERSE CAUSALITY MAY PROVE A MORE FRUITFUL AREA OF RESEARCH. TRIAL REGISTRATION: PROSPERO 2016: CRD42016037352 .	2017	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
8 3063  58 GENOME-WIDE DNA METHYLATION AND LONG-TERM AMBIENT AIR POLLUTION EXPOSURE IN KOREAN ADULTS. BACKGROUND: AMBIENT AIR POLLUTION IS ASSOCIATED WITH NUMEROUS ADVERSE HEALTH OUTCOMES, BUT THE UNDERLYING MECHANISMS ARE NOT WELL UNDERSTOOD; EPIGENETIC EFFECTS INCLUDING ALTERED DNA METHYLATION COULD PLAY A ROLE. TO EVALUATE ASSOCIATIONS OF LONG-TERM AIR POLLUTION EXPOSURE WITH DNA METHYLATION IN BLOOD, WE CONDUCTED AN EPIGENOME-WIDE ASSOCIATION STUDY IN A KOREAN CHRONIC OBSTRUCTIVE PULMONARY DISEASE COHORT (N = 100 INCLUDING 60 CASES) USING ILLUMINA'S INFINIUM HUMANMETHYLATION450K BEADCHIP. ANNUAL AVERAGE CONCENTRATIONS OF PARTICULATE MATTER </= 10 MUM IN DIAMETER (PM(10)) AND NITROGEN DIOXIDE (NO(2)) WERE ESTIMATED AT PARTICIPANTS' RESIDENTIAL ADDRESSES USING EXPOSURE PREDICTION MODELS. WE USED ROBUST LINEAR REGRESSION TO IDENTIFY DIFFERENTIALLY METHYLATED PROBES (DMPS) AND TWO DIFFERENT APPROACHES, DMRCATE AND COMB-P, TO IDENTIFY DIFFERENTIALLY METHYLATED REGIONS (DMRS). RESULTS: AFTER MULTIPLE TESTING CORRECTION (FALSE DISCOVERY RATE < 0.05), THERE WERE 12 DMPS AND 27 DMRS ASSOCIATED WITH PM(10) AND 45 DMPS AND 57 DMRS RELATED TO NO(2). DMP CG06992688 (OTUB2) AND SEVERAL DMRS WERE ASSOCIATED WITH BOTH EXPOSURES. ELEVEN DMPS IN RELATION TO NO(2) CONFIRMED PREVIOUS FINDINGS IN EUROPEANS; THE REMAINDER WERE NOVEL. METHYLATION LEVELS OF 39 DMPS WERE ASSOCIATED WITH EXPRESSION LEVELS OF NEARBY GENES IN A SEPARATE DATASET OF 3075 INDIVIDUALS. ENRICHED NETWORKS WERE RELATED TO OUTCOMES ASSOCIATED WITH AIR POLLUTION INCLUDING CARDIOVASCULAR AND RESPIRATORY DISEASES AS WELL AS INFLAMMATORY AND IMMUNE RESPONSES. CONCLUSIONS: THIS STUDY PROVIDES EVIDENCE THAT LONG-TERM AMBIENT AIR POLLUTION EXPOSURE IMPACTS DNA METHYLATION. THE DIFFERENTIAL METHYLATION SIGNALS CAN SERVE AS POTENTIAL AIR POLLUTION BIOMARKERS. THESE RESULTS MAY HELP BETTER UNDERSTAND THE INFLUENCES OF AMBIENT AIR POLLUTION ON HUMAN HEALTH.	2019	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         
9 2622  45 EPIGENOME-WIDE ASSOCIATION STUDIES IN ASTHMA: A SYSTEMATIC REVIEW. OBJECTIVE: ASTHMA IS A COMMON CHRONIC RESPIRATORY AIRWAY DISEASE INFLUENCED BY ENVIRONMENTAL FACTORS AND POSSIBLY THEIR INTERACTION WITH THE HUMAN GENOME CAUSING EPIGENETIC CHANGES. EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) HAVE MAINLY INVESTIGATED DNA METHYLATION AND ITS ASSOCIATION WITH DISEASE OR TRAITS, EXPOSURE FACTORS OR GENE EXPRESSION. THIS SYSTEMATIC REVIEW AIMED TO IDENTIFY ALL EWAS ASSESSING DIFFERENTIALLY METHYLATED SITES ASSOCIATED WITH ASTHMA IN HUMANS. DESIGN: STRUCTURED SYSTEMATIC LITERATURE SEARCH FOLLOWING PRISMA GUIDELINES, NEWCASTLE-OTTAWA SCALE (NOS) FOR COHORT STUDIES WAS USED FOR BIAS ASSESSMENT. DATA SOURCES: WE SEARCHED PUBMED AND EMBASE DATABASES FROM 2005 TO 2019. ELIGIBILITY CRITERIA: EPIGENOME-WIDE ASSOCIATION STUDIES TESTING ASSOCIATION BETWEEN DIFFERENTIAL METHYLATION AND ASTHMA IN HUMANS. RESULTS: OVERALL, WE IDENTIFIED 16 EWAS STUDIES COMPLYING WITH OUR SEARCH CRITERIA. TWELVE STUDIES WERE CONDUCTED ON CHILDREN, AND 10 WERE CONDUCTED ON SAMPLE SIZES <150 SUBJECTS. FOUR HUNDRED AND NINETEEN CPGS WERE REPORTED IN CHILDREN STUDIES AFTER CORRECTION FOR MULTIPLE TESTING. IN THE ADULT STUDIES, THOUSANDS OF DIFFERENTIALLY METHYLATED SITES WERE IDENTIFIED. DIFFERENTIAL METHYLATION IN INFLAMMATORY-RELATED GENES CORRELATED WITH HIGHER LEVELS OF GENE EXPRESSIONS OF INFLAMMATORY MODULATORS IN ASTHMA. DIFFERENTIALLY METHYLATED GENES ASSOCIATED WITH ASTHMA INCLUDED SMAD3, SERPINC1, PROK1, IL13, RUNX3 AND TIGIT. FORTY-ONE CPGS WERE REPLICATED AT LEAST ONCE IN BLOOD SAMPLES, AND 28 CPGS WERE REPLICATED IN NASAL SAMPLES. CONCLUSION: ALTHOUGH MANY DIFFERENTIALLY METHYLATED CPGS IN GENES KNOWN TO BE INVOLVED IN ASTHMA HAVE BEEN IDENTIFIED IN EWAS TO DATE, WE CONCLUDE THAT FURTHER STUDIES OF LARGER SAMPLE SIZES AND ANALYSES OF DIFFERENTIAL METHYLATION BETWEEN DIFFERENT PHENOTYPES ARE NEEDED IN ORDER TO COMPREHENSIVELY EVALUATE THE ROLE OF EPIGENETIC FACTORS IN THE PATHOPHYSIOLOGY AND HETEROGENEITY OF ASTHMA, AND THE POTENTIAL CLINICAL UTILITY TO PREDICT OR CLASSIFY PATIENTS WITH ASTHMA.	2019	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
10  497  34 ASSOCIATION BETWEEN BMI AND DNA METHYLATION IN BLOOD OR NORMAL ADULT BREAST TISSUE: A SYSTEMATIC REVIEW. BACKGROUND/AIM: SEVERAL STUDIES HAVE INVESTIGATED THE INFLUENCE OF OBESITY ON DNA METHYLATION (DNAM) TO FIND BIOMARKERS ASSOCIATED WITH THE DETECTION OF CHRONIC DISEASES, INCLUDING BREAST CANCER. THE AIM OF THE STUDY WAS TO SYSTEMATICALLY REVIEW STUDIES EXAMINING THE ASSOCIATION OF BODY MASS INDEX (BMI) AND DNAM IN BLOOD OR NORMAL BREAST TISSUE. MATERIALS AND METHODS: THREE SCIENTIFIC LITERATURE DATABASES (PUBMED, EMBASE AND WEB OF SCIENCE) WERE SCREENED UNTIL MAY 2018. RESULTS: TWENTY-FOUR STUDIES WERE INCLUDED ALONG WITH OURS IN WHICH WE INVESTIGATED THIS RELATION IN THE NORMAL BREAST TISSUE OF 40 BREAST CANCER PATIENTS. CONCLUSION: BMI-ASSOCIATED CPG SITES WERE HIGHLY VARIABLE WITH FEW IDENTIFIED IN LESS THAN HALF OF THE STUDIES. NEVERTHELESS, A FEW GENES POTENTIALLY ASSOCIATED WITH BMI WERE HIGHLIGHTED IN BLOOD (CPT1A, ABCG1, SREBF1 AND LGALS3BP) AND IN NORMAL BREAST TISSUE (PTPRN2 AND ABLIM2). THE VARIABILITY OF THE RESULTS COULD BE EXPLAINED BY THE TISSUE AND CELL-SPECIFICITY OF METHYLATION AND DIFFERENCES IN METHODOLOGY.	2020	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
11 6761  43 X CHROMOSOME-WIDE ANALYSIS IDENTIFIES DNA METHYLATION SITES INFLUENCED BY CIGARETTE SMOKING. BACKGROUND: TOBACCO SMOKING IS A MAJOR CAUSE OF CHRONIC DISEASE WORLDWIDE. SMOKING MAY INDUCE CELLULAR AND MOLECULAR CHANGES INCLUDING EPIGENETIC MODIFICATION, WITH BOTH SHORT-TERM AND LONG-TERM MODIFICATION PATTERNS THAT MAY CONTRIBUTE TO PHENOTYPIC EXPRESSION OF DISEASES. RECENT EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) HAVE IDENTIFIED DOZENS OF SMOKING-RELATED DNA METHYLATION (DNAM) SITES. HOWEVER, THE X CHROMOSOMAL DNAM SITES HAVE BEEN LARGELY OVERLOOKED DUE TO A LACK OF AN ANALYTICAL FRAMEWORK FOR DEALING WITH THE SEX-DIMORPHIC DISTRIBUTION. TO IDENTIFY NOVEL SMOKING-RELATED DNAM SITES ON THE X CHROMOSOME, WE EXAMINED THE MODALITY OF EACH X CHROMOSOMAL DNAM SITE AND CONDUCTED A SEX-SPECIFIC ASSOCIATION STUDY OF CIGARETTE SMOKING. RESULTS: WE USED A DISCOVERY SAMPLE OF 139 MIDDLE-AGE TWINS, AND THREE REPLICATION SAMPLES OF 78 TWINS, 464 AND 333 UNRELATED INDIVIDUALS INCLUDING 47, 17, 22, AND 89 CURRENT SMOKERS, RESPECTIVELY. AFTER CORRECTION FOR MULTIPLE TESTING, THE TOP SMOKING-RELATED DNAM SITES IN BCOR AND TSC22D3 WERE SIGNIFICANTLY HYPERMETHYLATED AND HYPOMETHYLATED, RESPECTIVELY, AMONG CURRENT SMOKERS. THESE SMOKING-ASSOCIATED SITES WERE REPLICATED WITH META-ANALYSIS P-VALUES OF 9.17 X 10(-12) AND 1.61 X 10(-9). FOR BOTH SITES, THE SMOKING EFFECTS ON METHYLATION LEVELS WERE LARGER IN MALES THAN THAT IN FEMALES. CONCLUSIONS: OUR FINDINGS HIGHLIGHT THE IMPORTANCE OF INVESTIGATING X CHROMOSOME METHYLATION PATTERNS AND THEIR ASSOCIATIONS WITH ENVIRONMENTAL EXPOSURES AND DISEASE PHENOTYPES AND DEMONSTRATE A ROBUST STATISTICAL METHODOLOGY FOR SUCH STUDY. EXISTING EWAS OF HUMAN DISEASES SHOULD INCORPORATE THE X CHROMOSOMAL SITES TO COMPLETE A COMPREHENSIVE EPIGENOME-WIDE SCAN.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
12 1497  40 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
13  667  57 BLOOD-BASED EPIGENOME-WIDE ANALYSES OF 19 COMMON DISEASE STATES: A LONGITUDINAL, POPULATION-BASED LINKED COHORT STUDY OF 18,413 SCOTTISH INDIVIDUALS. BACKGROUND: DNA METHYLATION IS A DYNAMIC EPIGENETIC MECHANISM THAT OCCURS AT CYTOSINE-PHOSPHATE-GUANINE DINUCLEOTIDE (CPG) SITES. EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) INVESTIGATE THE STRENGTH OF ASSOCIATION BETWEEN METHYLATION AT INDIVIDUAL CPG SITES AND HEALTH OUTCOMES. ALTHOUGH BLOOD METHYLATION MAY ACT AS A PERIPHERAL MARKER OF COMMON DISEASE STATES, PREVIOUS EWAS HAVE TYPICALLY FOCUSED ONLY ON INDIVIDUAL CONDITIONS AND HAVE HAD LIMITED POWER TO DISCOVER DISEASE-ASSOCIATED LOCI. THIS STUDY EXAMINED THE ASSOCIATION OF BLOOD DNA METHYLATION WITH THE PREVALENCE OF 14 DISEASE STATES AND THE INCIDENCE OF 19 DISEASE STATES IN A SINGLE POPULATION OF OVER 18,000 SCOTTISH INDIVIDUALS. METHODS AND FINDINGS: DNA METHYLATION WAS ASSAYED AT 752,722 CPG SITES IN WHOLE-BLOOD SAMPLES FROM 18,413 VOLUNTEERS IN THE FAMILY-STRUCTURED, POPULATION-BASED COHORT STUDY GENERATION SCOTLAND (AGE RANGE 18 TO 99 YEARS). EWAS TESTED FOR CROSS-SECTIONAL ASSOCIATIONS BETWEEN BASELINE CPG METHYLATION AND 14 PREVALENT DISEASE STATES, AND FOR LONGITUDINAL ASSOCIATIONS BETWEEN BASELINE CPG METHYLATION AND 19 INCIDENT DISEASE STATES. PREVALENT CASES WERE SELF-REPORTED ON HEALTH QUESTIONNAIRES AT THE BASELINE. INCIDENT CASES WERE IDENTIFIED USING LINKAGE TO SCOTTISH PRIMARY (READ 2) AND SECONDARY (ICD-10) CARE RECORDS, AND THE CENSORING DATE WAS SET TO OCTOBER 2020. THE MEAN TIME-TO-DIAGNOSIS RANGED FROM 5.0 YEARS (FOR CHRONIC PAIN) TO 11.7 YEARS (FOR CORONAVIRUS DISEASE 2019 (COVID-19) HOSPITALISATION). THE 19 DISEASE STATES CONSIDERED IN THIS STUDY WERE SELECTED IF THEY WERE PRESENT ON THE WORLD HEALTH ORGANISATION'S 10 LEADING CAUSES OF DEATH AND DISEASE BURDEN OR INCLUDED IN BASELINE SELF-REPORT QUESTIONNAIRES. EWAS MODELS WERE ADJUSTED FOR AGE AT METHYLATION TYPING, SEX, ESTIMATED WHITE BLOOD CELL COMPOSITION, POPULATION STRUCTURE, AND 5 COMMON LIFESTYLE RISK FACTORS. A STRUCTURED LITERATURE REVIEW WAS ALSO CONDUCTED TO IDENTIFY EXISTING EWAS FOR ALL 19 DISEASE STATES TESTED. THE MEDLINE, EMBASE, WEB OF SCIENCE, AND PREPRINT SERVERS WERE SEARCHED TO RETRIEVE RELEVANT ARTICLES INDEXED AS OF MARCH 27, 2023. FIFTY-FOUR OF APPROXIMATELY 2,000 INDEXED ARTICLES MET OUR INCLUSION CRITERIA: ASSAYED BLOOD-BASED DNA METHYLATION, HAD >20 INDIVIDUALS IN EACH COMPARISON GROUP, AND EXAMINED ONE OF THE 19 CONDITIONS CONSIDERED. FIRST, WE ASSESSED WHETHER THE ASSOCIATIONS IDENTIFIED IN OUR STUDY WERE REPORTED IN PREVIOUS STUDIES. WE IDENTIFIED 69 ASSOCIATIONS BETWEEN CPGS AND THE PREVALENCE OF 4 CONDITIONS, OF WHICH 58 WERE NEWLY DESCRIBED. THE CONDITIONS WERE BREAST CANCER, CHRONIC KIDNEY DISEASE, ISCHEMIC HEART DISEASE, AND TYPE 2 DIABETES MELLITUS. WE ALSO UNCOVERED 64 CPGS THAT ASSOCIATED WITH THE INCIDENCE OF 2 DISEASE STATES (COPD AND TYPE 2 DIABETES), OF WHICH 56 WERE NOT REPORTED IN THE SURVEYED LITERATURE. SECOND, WE ASSESSED REPLICATION ACROSS EXISTING STUDIES, WHICH WAS DEFINED AS THE REPORTING OF AT LEAST 1 COMMON SITE IN >2 STUDIES THAT EXAMINED THE SAME CONDITION. ONLY 6/19 DISEASE STATES HAD EVIDENCE OF SUCH REPLICATION. THE LIMITATIONS OF THIS STUDY INCLUDE THE NONCONSIDERATION OF MEDICATION DATA AND A POTENTIAL LACK OF GENERALIZABILITY TO INDIVIDUALS THAT ARE NOT OF SCOTTISH AND EUROPEAN ANCESTRY. CONCLUSIONS: WE DISCOVERED OVER 100 ASSOCIATIONS BETWEEN BLOOD METHYLATION SITES AND COMMON DISEASE STATES, INDEPENDENTLY OF MAJOR CONFOUNDING RISK FACTORS, AND A NEED FOR GREATER STANDARDISATION AMONG EWAS ON HUMAN DISEASE.	2023	

14  382  55 AN EPIGENOME-WIDE STUDY OF BODY MASS INDEX AND DNA METHYLATION IN BLOOD USING PARTICIPANTS FROM THE SISTER STUDY COHORT. BACKGROUND/OBJECTIVES: THE RELATIONSHIP BETWEEN OBESITY AND CHRONIC DISEASE RISK IS WELL-ESTABLISHED; THE UNDERLYING BIOLOGICAL MECHANISMS DRIVING THIS RISK INCREASE MAY INCLUDE OBESITY-RELATED EPIGENETIC MODIFICATIONS. TO EXPLORE THIS HYPOTHESIS, WE CONDUCTED A GENOME-WIDE ANALYSIS OF DNA METHYLATION AND BODY MASS INDEX (BMI) USING DATA FROM A SUBSET OF WOMEN IN THE SISTER STUDY. SUBJECTS/METHODS: THE SISTER STUDY IS A COHORT OF 50 884 US WOMEN WHO HAD A SISTER WITH BREAST CANCER BUT WERE FREE OF BREAST CANCER THEMSELVES AT ENROLLMENT. STUDY PARTICIPANTS COMPLETED EXAMINATIONS WHICH INCLUDED MEASUREMENTS OF HEIGHT AND WEIGHT, AND PROVIDED BLOOD SAMPLES. BLOOD DNA METHYLATION DATA GENERATED WITH THE ILLUMINA INFINIUM HUMANMETHYLATION27 BEADCHIP ARRAY COVERING 27,589 CPG SITES WAS AVAILABLE FOR 871 WOMEN FROM A PRIOR STUDY OF BREAST CANCER AND DNA METHYLATION. TO IDENTIFY DIFFERENTIALLY METHYLATED CPG SITES ASSOCIATED WITH BMI, WE ANALYZED THIS METHYLATION DATA USING ROBUST LINEAR REGRESSION WITH ADJUSTMENT FOR AGE AND CASE STATUS. FOR THOSE CPGS PASSING THE FALSE DISCOVERY RATE SIGNIFICANCE LEVEL, WE EXAMINED THE ASSOCIATION IN A REPLICATION SET COMPRISED OF A NON-OVERLAPPING GROUP OF 187 WOMEN FROM THE SISTER STUDY WHO HAD DNA METHYLATION DATA GENERATED USING THE INFINIUM HUMANMETHYLATION450 BEADCHIP ARRAY. ANALYSIS OF THIS EXPANDED 450 K ARRAY IDENTIFIED ADDITIONAL BMI-ASSOCIATED SITES WHICH WERE INVESTIGATED WITH TARGETED PYROSEQUENCING. RESULTS: FOUR CPG SITES REACHED GENOME-WIDE SIGNIFICANCE (FALSE DISCOVERY RATE (FDR) Q<0.05) IN THE DISCOVERY SET AND ASSOCIATIONS FOR ALL FOUR WERE SIGNIFICANT AT STRICT BONFERRONI CORRECTION IN THE REPLICATION SET. AN ADDITIONAL 23 SITES PASSED FDR IN THE REPLICATION SET AND FIVE WERE REPLICATED BY PYROSEQUENCING IN THE DISCOVERY SET. SEVERAL OF THE GENES IDENTIFIED INCLUDING ANGPT4, RORC, SOCS3, FSD2, XYLT1, ABCG1, STK39, ASB2 AND CRHR2 HAVE BEEN LINKED TO OBESITY AND OBESITY-RELATED CHRONIC DISEASES. CONCLUSIONS: OUR FINDINGS SUPPORT THE HYPOTHESIS THAT OBESITY-RELATED EPIGENETIC DIFFERENCES ARE DETECTABLE IN BLOOD AND MAY BE RELATED TO RISK OF CHRONIC DISEASE.	2017	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
15 2633  50 EPIGENOME-WIDE DNA METHYLATION PATTERNS ASSOCIATED WITH FATIGUE IN PRIMARY SJOGREN'S SYNDROME. OBJECTIVE: CHRONIC FATIGUE IS A COMMON, DISABLING AND POORLY UNDERSTOOD PHENOMENON. RECENT STUDIES INDICATE THAT EPIGENETIC MECHANISMS MAY BE INVOLVED IN THE EXPRESSION OF FATIGUE, A PROMINENT FEATURE OF PRIMARY SS (PSS). THE AIM OF THIS STUDY WAS TO INVESTIGATE WHETHER DNA METHYLATION PROFILES OF WHOLE BLOOD ARE ASSOCIATED WITH FATIGUE IN PATIENTS WITH PSS. METHODS: FORTY-EIGHT PSS PATIENTS WITH HIGH (N = 24) OR LOW (N = 24) FATIGUE AS MEASURED BY A VISUAL ANALOGUE SCALE WERE INCLUDED. GENOME-WIDE DNA METHYLATION WAS INVESTIGATED USING THE ILLUMINA HUMANMETHYLATION450 BEADCHIP ARRAY. AFTER QUALITY CONTROL, A TOTAL OF 383 358 CYTOSINE-PHOSPHATE-GUANINE (CPG) SITES REMAINED FOR FURTHER ANALYSIS. AGE, SEX AND DIFFERENTIAL CELL COUNT ESTIMATES WERE INCLUDED AS COVARIATES IN THE ASSOCIATION MODEL. A FALSE DISCOVERY RATE-CORRECTED P < 0.05 WAS CONSIDERED SIGNIFICANT, AND A CUT-OFF OF 3% AVERAGE DIFFERENCE IN METHYLATION LEVELS BETWEEN HIGH- AND LOW-FATIGUE PATIENTS WAS APPLIED. RESULTS: A TOTAL OF 251 DIFFERENTIALLY METHYLATED CPG SITES WERE ASSOCIATED WITH FATIGUE. THE CPG SITE WITH THE MOST PRONOUNCED HYPOMETHYLATION IN PSS HIGH FATIGUE ANNOTATED TO THE SBF2-ANTISENSE RNA1 GENE. THE MOST DISTINCT HYPERMETHYLATION WAS OBSERVED AT A CPG SITE ANNOTATED TO THE LYMPHOTOXIN ALPHA GENE. FUNCTIONAL PATHWAY ANALYSIS OF GENES WITH DIFFERENTLY METHYLATED CPG SITES IN SUBJECTS WITH HIGH VS LOW FATIGUE REVEALED ENRICHMENT IN SEVERAL PATHWAYS ASSOCIATED WITH INNATE AND ADAPTIVE IMMUNITY. CONCLUSION: SOME GENES INVOLVED IN REGULATION OF THE IMMUNE SYSTEM AND IN INFLAMMATION ARE DIFFERENTLY METHYLATED IN PSS PATIENTS WITH HIGH VS LOW FATIGUE. THESE FINDINGS POINT TO FUNCTIONAL NETWORKS THAT MAY UNDERLIE FATIGUE. EPIGENETIC CHANGES COULD CONSTITUTE A FATIGUE-REGULATING MECHANISM IN PSS.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
16 2418  44 EPIGENETIC SIGNATURE OF CHRONIC LOW BACK PAIN IN HUMAN T CELLS. OBJECTIVE: DETERMINE IF CHRONIC LOW BACK PAIN (LBP) IS ASSOCIATED WITH DNA METHYLATION SIGNATURES IN HUMAN T CELLS THAT WILL REVEAL NOVEL MECHANISMS AND POTENTIAL THERAPEUTIC TARGETS AND EXPLORE THE FEASIBILITY OF EPIGENETIC DIAGNOSTIC MARKERS FOR PAIN-RELATED PATHOPHYSIOLOGY. METHODS: GENOME-WIDE DNA METHYLATION ANALYSIS OF 850,000 CPG SITES IN WOMEN AND MEN WITH CHRONIC LBP AND PAIN-FREE CONTROLS WAS PERFORMED. T CELLS WERE ISOLATED (DISCOVERY COHORT, N = 32) AND USED TO IDENTIFY DIFFERENTIALLY METHYLATED CPG SITES, AND GENE ONTOLOGIES AND MOLECULAR PATHWAYS WERE IDENTIFIED. A POLYGENIC DNA METHYLATION SCORE FOR LBP WAS GENERATED IN BOTH WOMEN AND MEN. VALIDATION WAS PERFORMED IN AN INDEPENDENT COHORT (VALIDATION COHORT, N = 63) OF CHRONIC LBP AND HEALTHY CONTROLS. RESULTS: ANALYSIS WITH THE DISCOVERY COHORT REVEALED A TOTAL OF 2,496 AND 419 DIFFERENTIALLY METHYLATED CPGS IN WOMEN AND MEN, RESPECTIVELY. IN WOMEN, MOST OF THESE SITES WERE HYPOMETHYLATED AND ENRICHED IN GENES WITH FUNCTIONS IN THE EXTRACELLULAR MATRIX, IN THE IMMUNE SYSTEM (IE, CYTOKINES), OR IN EPIGENETIC PROCESSES. IN MEN, A UNIQUE CHRONIC LBP DNA METHYLATION SIGNATURE WAS IDENTIFIED CHARACTERIZED BY SIGNIFICANT ENRICHMENT FOR GENES FROM THE MAJOR HISTOCOMPATIBILITY COMPLEX. SEX-SPECIFIC POLYGENIC DNA METHYLATION SCORES WERE GENERATED TO ESTIMATE THE PAIN STATUS OF EACH INDIVIDUAL AND CONFIRMED IN THE VALIDATION COHORT USING PYROSEQUENCING. CONCLUSION: THIS STUDY REVEALS SEX-SPECIFIC DNA METHYLATION SIGNATURES IN HUMAN T CELLS THAT DISCRIMINATES CHRONIC LBP PARTICIPANTS FROM HEALTHY CONTROLS.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
17 3557  49 IMPACT OF BMI AND WAIST CIRCUMFERENCE ON EPIGENOME-WIDE DNA METHYLATION AND IDENTIFICATION OF EPIGENETIC BIOMARKERS IN BLOOD: AN EWAS IN MULTI-ETHNIC ASIAN INDIVIDUALS. BACKGROUND: THE PREVALENCE OF OBESITY AND ITS RELATED CHRONIC DISEASES HAVE BEEN INCREASING ESPECIALLY IN ASIAN COUNTRIES. OBESITY-RELATED GENETIC VARIANTS HAVE BEEN IDENTIFIED, BUT THESE EXPLAIN LITTLE OF THE VARIATION IN BMI. RECENT STUDIES REPORTED ASSOCIATIONS BETWEEN DNA METHYLATION AND OBESITY, MOSTLY IN NON-ASIAN POPULATIONS. METHODS: WE PERFORMED AN EPIGENOME-WIDE ASSOCIATION STUDY (EWAS) ON GENERAL ADIPOSITY (BODY MASS INDEX, BMI) AND ABDOMINAL ADIPOSITY (WAIST CIRCUMFERENCE, WC) IN 409 MULTI-ETHNIC ASIAN INDIVIDUALS AND REPLICATED BMI AND WAIST-ASSOCIATED DNA METHYLATION CPGS IDENTIFIED IN OTHER POPULATIONS. THE CROSS-LAGGED PANEL MODEL AND MENDELIAN RANDOMIZATION WERE USED TO ASSESS THE TEMPORAL RELATIONSHIP BETWEEN METHYLATION AND BMI. THE TEMPORAL RELATIONSHIP BETWEEN THE IDENTIFIED CPGS AND INFLAMMATION AND METABOLIC MARKERS WAS ALSO EXAMINED. RESULTS: EWAS IDENTIFIED 116 DNA METHYLATION CPGS INDEPENDENTLY ASSOCIATED WITH BMI AND EIGHT INDEPENDENTLY ASSOCIATED WITH WC AT FALSE DISCOVERY RATE P(FDR) < 0.05 IN 409 ASIAN SAMPLES. WE REPLICATED 110 BMI-ASSOCIATED CPGS PREVIOUSLY REPORTED IN EUROPEANS AND IDENTIFIED SIX NOVEL BMI-ASSOCIATED CPGS AND TWO NOVEL WC-ASSOCIATED CPGS. WE OBSERVED HIGH CONSISTENCY IN ASSOCIATION DIRECTION OF EFFECT COMPARED TO STUDIES IN OTHER POPULATIONS. CAUSAL RELATIONSHIP ANALYSES INDICATED THAT BMI WAS MORE LIKELY TO BE THE CAUSE OF DNA METHYLATION ALTERATION, RATHER THAN THE CONSEQUENCE. THE CAUSAL ANALYSES USING BMI-ASSOCIATED METHYLATION RISK SCORE ALSO SUGGESTED THAT HIGHER LEVELS OF THE INFLAMMATION MARKER IL-6 WERE LIKELY THE CONSEQUENCE OF METHYLATION CHANGE. CONCLUSION: OUR STUDY PROVIDES EVIDENCE OF AN ASSOCIATION BETWEEN OBESITY AND DNA METHYLATION IN MULTI-ETHNIC ASIANS AND SUGGESTS THAT OBESITY CAN DRIVE METHYLATION CHANGE. THE RESULTS ALSO SUGGESTED POSSIBLE CAUSAL INFLUENCE THAT OBESITY-RELATED METHYLATION CHANGES MIGHT HAVE ON INFLAMMATION AND LIPOPROTEIN LEVELS.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
18 5395  41 REDUCED EPIGENETIC AGE IN OLDER ADULTS WITH HIGH SENSE OF PURPOSE IN LIFE. PSYCHOSOCIAL RISK FACTORS HAVE BEEN LINKED WITH ACCELERATED EPIGENETIC AGING, BUT LITTLE IS KNOWN ABOUT WHETHER PSYCHOSOCIAL RESILIENCE FACTORS (EG, SENSE OF PURPOSE IN LIFE) MIGHT REDUCE EPIGENETIC AGE ACCELERATION. IN THIS STUDY, WE TESTED IF OLDER ADULTS WHO EXPERIENCE HIGH LEVELS OF PURPOSE MIGHT SHOW REDUCED EPIGENETIC AGE ACCELERATION. WE EVALUATED THE RELATIONSHIP BETWEEN PURPOSE AND EPIGENETIC AGE ACCELERATION AS MEASURED BY 13 DNA METHYLATION (DNAM) "EPIGENETIC CLOCKS" ASSESSED IN 1 572 OLDER ADULTS FROM THE HEALTH AND RETIREMENT STUDY (MEAN AGE 70 YEARS). WE QUANTIFIED THE TOTAL ASSOCIATION BETWEEN PURPOSE AND DNAM AGE ACCELERATION AS WELL AS THE EXTENT TO WHICH THAT TOTAL ASSOCIATION MIGHT BE ATTRIBUTABLE TO DEMOGRAPHIC FACTORS, CHRONIC DISEASE, OTHER PSYCHOSOCIAL VARIABLES (EG, POSITIVE AFFECT), AND HEALTH-RELATED BEHAVIORS (HEAVY DRINKING, SMOKING, PHYSICAL ACTIVITY, AND BODY MASS INDEX [BMI]). PURPOSE IN LIFE WAS ASSOCIATED WITH REDUCED EPIGENETIC AGE ACCELERATION ACROSS 4 "SECOND-GENERATION" DNAM CLOCKS OPTIMIZED FOR PREDICTING HEALTH AND LONGEVITY (FALSE DISCOVERY RATE [FDR] Q < 0.0001: PHENOAGE, GRIMAGE, ZHANG EPIGENETIC MORTALITY INDEX; FDR Q < 0.05: DUNEDINPOAM). THESE ASSOCIATIONS WERE INDEPENDENT OF DEMOGRAPHIC AND PSYCHOSOCIAL FACTORS, BUT SUBSTANTIALLY ATTENUATED AFTER ADJUSTING FOR HEALTH-RELATED BEHAVIORS (DRINKING, SMOKING, PHYSICAL ACTIVITY, AND BMI). PURPOSE SHOWED NO SIGNIFICANT ASSOCIATION WITH 9 "FIRST-GENERATION" DNAM EPIGENETIC CLOCKS TRAINED ON CHRONOLOGICAL AGE. OLDER ADULTS WITH GREATER PURPOSE IN LIFE SHOW "YOUNGER" DNAM EPIGENETIC AGE ACCELERATION. THESE RESULTS MAY BE DUE IN PART TO ASSOCIATED DIFFERENCES IN HEALTH-RELATED BEHAVIORS. RESULTS SUGGEST NEW OPPORTUNITIES TO REDUCE BIOLOGICAL AGE ACCELERATION BY ENHANCING PURPOSE AND ITS BEHAVIORAL SEQUELAE IN LATE ADULTHOOD.	2023	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             
19 1672  42 DRD4 METHYLATION AS A POTENTIAL BIOMARKER FOR PHYSICAL AGGRESSION: AN EPIGENOME-WIDE, CROSS-TISSUE INVESTIGATION. EPIGENETIC PROCESSES THAT REGULATE GENE EXPRESSION, SUCH AS DNA METHYLATION (DNAM), HAVE BEEN LINKED TO INDIVIDUAL DIFFERENCES IN PHYSICAL AGGRESSION. YET, IT IS CURRENTLY UNCLEAR WHETHER: (A) DNAM PATTERNS IN HUMANS ASSOCIATE WITH PHYSICAL AGGRESSION INDEPENDENTLY OF OTHER CO-OCCURRING PSYCHIATRIC AND BEHAVIORAL SYMPTOMS; (B) WHETHER THESE PATTERNS ARE OBSERVABLE ACROSS MULTIPLE TISSUES; AND (C) WHETHER THEY MAY FUNCTION AS A CAUSAL VERSUS NONCAUSAL BIOMARKER OF PHYSICAL AGGRESSION. HERE, WE USED A MULTISAMPLE, CROSS-TISSUE DESIGN TO ADDRESS THESE QUESTIONS. FIRST, WE EXAMINED GENOME-WIDE DNAM PATTERNS (BUCCAL SWABS; ILLUMINA 450K) ASSOCIATED WITH ENGAGEMENT IN PHYSICAL FIGHTS IN A SAMPLE OF HIGH-RISK YOUTH (N = 119; AGE = 16-24 YEARS; 53% FEMALE). WE IDENTIFIED ONE DIFFERENTIALLY METHYLATED REGION IN DRD4, WHICH SURVIVED GENOME-WIDE CORRECTION, ASSOCIATED WITH PHYSICAL AGGRESSION ABOVE AND BEYOND CO-OCCURRING SYMPTOMATOLOGY (E.G., ADHD, SUBSTANCE USE), AND SHOWED STRONG CROSS-TISSUE CONCORDANCE WITH BOTH BLOOD AND BRAIN. SECOND, WE FOUND THAT DNAM SITES WITHIN THIS REGION WERE ALSO DIFFERENTIALLY METHYLATED IN AN INDEPENDENT SAMPLE OF YOUNG ADULTS, BETWEEN INDIVIDUALS WITH A HISTORY OF CHRONIC-HIGH VERSUS LOW PHYSICAL AGGRESSION (PERIPHERAL T CELLS; AGES 26-28). FINALLY, WE RAN A MENDELIAN RANDOMIZATION ANALYSIS USING GWAS DATA FROM THE EAGLE CONSORTIUM TO TEST FOR A CAUSAL ASSOCIATION OF DRD4 METHYLATION WITH PHYSICAL AGGRESSION. ONLY ONE GENETIC INSTRUMENT WAS ELIGIBLE FOR THE ANALYSIS, AND RESULTS PROVIDED NO EVIDENCE FOR A CAUSAL ASSOCIATION. OVERALL, OUR FINDINGS LEND SUPPORT FOR PERIPHERAL DRD4 METHYLATION AS A POTENTIAL BIOMARKER OF PHYSICALLY AGGRESSIVE BEHAVIOR, WITH NO EVIDENCE YET OF A CAUSAL RELATIONSHIP.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
20  561  53 BARIATRIC SURGERY-INDUCED WEIGHT LOSS AND ASSOCIATED GENOME-WIDE DNA-METHYLATION ALTERATIONS IN OBESE INDIVIDUALS. BACKGROUND: OBESITY IS A MULTIFACTORIAL AND CHRONIC CONDITION OF GROWING UNIVERSAL CONCERN. IT HAS RECENTLY BEEN REPORTED THAT BARIATRIC SURGERY IS A MORE SUCCESSFUL TREATMENT FOR SEVERE OBESITY THAN OTHER NONINVASIVE INTERVENTIONS, RESULTING IN RAPID SIGNIFICANT WEIGHT LOSS AND ASSOCIATED CHRONIC DISEASE REMISSION. THE IDENTIFICATION OF DISTINCT EPIGENETIC PATTERNS IN PATIENTS WHO ARE OBESE OR HAVE METABOLIC IMBALANCES HAS SUGGESTED A POTENTIAL ROLE FOR EPIGENETIC ALTERATIONS IN CAUSAL OR MEDIATING PATHWAYS IN THE DEVELOPMENT OF OBESITY-RELATED PATHOLOGIES. SPECIFIC CHANGES IN THE EPIGENOME (DNA METHYLOME), ASSOCIATED WITH METABOLIC DISORDERS, CAN BE DETECTED IN THE BLOOD. WE INVESTIGATED WHETHER SUCH EPIGENETIC CHANGES ARE REVERSIBLE AFTER WEIGHT LOSS USING GENOME-WIDE DNA METHYLOME ANALYSIS OF BLOOD SAMPLES FROM INDIVIDUALS WITH SEVERE OBESITY (MEAN BMI ~ 45) UNDERGOING BARIATRIC SURGERY. RESULTS: OUR ANALYSIS REVEALED 41 SIGNIFICANT (BONFERRONI P < 0.05) AND 1169 (FALSE DISCOVERY RATE P < 0.05) SUGGESTIVE DIFFERENTIALLY METHYLATED POSITIONS (DMPS) ASSOCIATED WITH WEIGHT LOSS DUE TO BARIATRIC SURGERY. AMONG THE 41 SIGNIFICANT DMPS, 5 CPGS WERE REPLICATED IN AN INDEPENDENT COHORT OF BMI-DISCORDANT MONOZYGOTIC TWINS (THE HEAVIER TWIN UNDERWENT DIET-INDUCED WEIGHT LOSS). THE EFFECT SIZES OF THESE 5 CPGS WERE CONSISTENT ACROSS DISCOVERY AND REPLICATION SETS (P < 0.05). WE ALSO IDENTIFIED 192 DIFFERENTIALLY METHYLATED REGIONS (DMRS) AMONG WHICH SMAD6 AND PFKFB3 GENES WERE THE TOP HYPERMETHYLATED AND HYPOMETHYLATED REGIONS, RESPECTIVELY. PATHWAY ENRICHMENT ANALYSIS OF THE DMR-ASSOCIATED GENES SHOWED THAT FUNCTIONAL PATHWAYS RELATED TO IMMUNE FUNCTION AND TYPE 1 DIABETES WERE SIGNIFICANT. WEIGHT LOSS DUE TO BARIATRIC SURGERY ALSO SIGNIFICANTLY DECELERATED EPIGENETIC AGE 12 MONTHS AFTER THE INTERVENTION (MEAN = - 4.29; P = 0.02). CONCLUSIONS: WE IDENTIFIED WEIGHT LOSS-ASSOCIATED DNA-METHYLATION ALTERATIONS TARGETING IMMUNE AND INFLAMMATORY GENE PATHWAYS IN BLOOD SAMPLES FROM BARIATRIC-SURGERY PATIENTS. THE TOP HITS WERE REPLICATED IN SAMPLES FROM AN INDEPENDENT COHORT OF BMI-DISCORDANT MONOZYGOTIC TWINS FOLLOWING A HYPOCALORIC DIET. ENERGY RESTRICTION AND BARIATRIC SURGERY THUS SHARE CPGS THAT MAY REPRESENT EARLY INDICATORS OF RESPONSE TO THE METABOLIC EFFECTS OF WEIGHT LOSS. THE ANALYSIS OF BARIATRIC SURGERY-ASSOCIATED DMRS SUGGESTS THAT EPIGENETIC REGULATION OF GENES INVOLVED IN ENDOTHELIAL AND ADIPOSE TISSUE FUNCTION IS KEY IN THE PATHOPHYSIOLOGY OF OBESITY.	2022