1 475 170 ARSENIC EXPOSURE AND HUMAN BLOOD DNA METHYLATION AND HYDROXYMETHYLATION PROFILES IN TWO DIVERSE POPULATIONS FROM BANGLADESH AND SPAIN. BACKGROUND: ASSOCIATIONS OF ARSENIC (AS) WITH THE SUM OF 5-MC AND 5-HMC LEVELS HAVE BEEN REPORTED; HOWEVER, AS EXPOSURE-RELATED DIFFERENCES OF THE SEPARATED 5-MC AND 5-HMC MARKERS HAVE RARELY BEEN STUDIED. METHODS: IN THIS STUDY, WE EVALUATED THE ASSOCIATION OF ARSENIC EXPOSURE BIOMARKERS AND 5-MC AND 5-HMC IN 30 HEALTHY MEN (43-55 YEARS) FROM THE ARAGON WORKERS HEALTH STUDY (AWHS) (SPAIN) AND 31 HEALTHY MEN (31-50 YEARS) FROM THE FOLIC ACID AND CREATININE TRIAL (FACT) (BANGLADESH). WE CONDUCTED 5-MC AND 5-HMC PROFILING USING INFINIUM METHYLATIONEPIC ARRAYS, ON PAIRED STANDARD AND MODIFIED (OX-BS IN AWHS AND TAB IN FACT) BISULFITE CONVERTED BLOOD DNA SAMPLES. RESULTS: THE MEDIAN FOR THE SUM OF URINE INORGANIC AND METHYLATED AS SPECIES (SIGMAAS) (MUG/L) WAS 12.5 FOR AWHS AND 89.6 FOR FACT. THE MEDIAN OF BLOOD AS (MUG/L) WAS 8.8 FOR AWHS AND 10.2 FOR FACT. AT A STATISTICAL SIGNIFICANCE P-VALUE CUT-OFF OF 0.01, THE DIFFERENTIALLY METHYLATED (DMP) AND HYDROXYMETHYLATED (DHP) POSITIONS WERE MOSTLY LOCATED IN DIFFERENT GENOMIC SITES. SEVERAL DMPS AND DHPS WERE CONSISTENTLY FOUND IN AWHS AND FACT BOTH FOR URINE SIGMAAS AND BLOOD MODELS, BEING OF SPECIAL INTEREST THOSE ATTRIBUTED TO THE DIP2C GENE. THREE DMPS (ANNOTATED TO CLEC12A) FOR AWHS AND ONE DHP (ANNOTATED TO NPLOC4) FOR FACT REMAINED STATISTICALLY SIGNIFICANT AFTER FALSE DISCOVERY RATE (FDR) CORRECTION. PATHWAYS RELATED TO CHRONIC DISEASES INCLUDING CARDIOVASCULAR, CANCER AND NEUROLOGICAL WERE ENRICHED. CONCLUSIONS: WHILE WE IDENTIFIED COMMON 5-HMC AND 5-MC SIGNATURES IN TWO POPULATIONS EXPOSED TO VARYING LEVELS OF INORGANIC AS, DIFFERENCES IN AS-RELATED EPIGENETIC SITES ACROSS THE STUDY POPULATIONS MAY ADDITIONALLY REFLECT LOW AND HIGH AS-SPECIFIC ASSOCIATIONS. THIS WORK CONTRIBUTES A DEEPER UNDERSTANDING OF POTENTIAL EPIGENETIC DYSREGULATIONS OF AS. HOWEVER, FURTHER RESEARCH IS NEEDED TO CONFIRM BIOLOGICAL CONSEQUENCES ASSOCIATED WITH DIP2C EPIGENETIC REGULATION AND TO INVESTIGATE THE ROLE OF 5-HMC AND 5-MC SEPARATELY IN AS-INDUCED HEALTH DISORDERS AT DIFFERENT EXPOSURE LEVELS. 2022 2 2921 49 GENE-SPECIFIC DIFFERENTIAL DNA METHYLATION AND CHRONIC ARSENIC EXPOSURE IN AN EPIGENOME-WIDE ASSOCIATION STUDY OF ADULTS IN BANGLADESH. BACKGROUND: INORGANIC ARSENIC IS ONE OF THE MOST COMMON NATURALLY OCCURRING CONTAMINANTS FOUND IN THE ENVIRONMENT. ARSENIC IS ASSOCIATED WITH A NUMBER OF HEALTH OUTCOMES, WITH EPIGENETIC MODIFICATION SUGGESTED AS A POTENTIAL MECHANISM OF TOXICITY. OBJECTIVE: AMONG A SAMPLE OF 400 ADULT PARTICIPANTS, WE EVALUATED THE ASSOCIATION BETWEEN ARSENIC EXPOSURE, AS MEASURED BY BLOOD AND URINARY TOTAL ARSENIC CONCENTRATIONS, AND EPIGENOME-WIDE WHITE BLOOD CELL DNA METHYLATION. METHODS: WE USED LINEAR REGRESSION MODELS TO EXAMINE THE ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND METHYLATION AT EACH CPG SITE, ADJUSTED FOR SEX, AGE, AND BATCH. DIFFERENTIALLY METHYLATED LOCI WERE SUBSEQUENTLY EXAMINED IN RELATION TO CORRESPONDING GENE EXPRESSION FOR FUNCTIONAL EVIDENCE OF GENE REGULATION. RESULTS: IN ADJUSTED ANALYSES, WE OBSERVED FOUR DIFFERENTIALLY METHYLATED CPG SITES WITH URINARY TOTAL ARSENIC CONCENTRATION AND THREE DIFFERENTIALLY METHYLATED CPG SITES WITH BLOOD ARSENIC CONCENTRATION, BASED ON THE BONFERRONI-CORRECTED SIGNIFICANCE THRESHOLD OF P < 1 X 10(-7). METHYLATION OF PLA2G2C (PROBE CG04605617) WAS THE MOST SIGNIFICANTLY ASSOCIATED LOCUS IN RELATION TO BOTH URINARY (P = 3.40 X 10(-11)) AND BLOOD ARSENIC CONCENTRATIONS (P = 1.48 X 10(-11)). THREE ADDITIONAL NOVEL METHYLATION LOCI-SQSTM1 (CG01225779), SLC4A4 (CG06121226), AND IGH (CG13651690)--WERE ALSO SIGNIFICANTLY ASSOCIATED WITH ARSENIC EXPOSURE. FURTHER, THERE WAS EVIDENCE OF METHYLATION-RELATED GENE REGULATION BASED ON GENE EXPRESSION FOR A SUBSET OF DIFFERENTIALLY METHYLATED LOCI. CONCLUSIONS: WE OBSERVED SIGNIFICANT ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND GENE-SPECIFIC DIFFERENTIAL WHITE BLOOD CELL DNA METHYLATION, SUGGESTING THAT EPIGENETIC MODIFICATIONS MAY BE AN IMPORTANT PATHWAY UNDERLYING ARSENIC TOXICITY. THE SPECIFIC DIFFERENTIALLY METHYLATED LOCI IDENTIFIED MAY INFORM POTENTIAL PATHWAYS FOR FUTURE INTERVENTIONS. 2015 3 1529 38 DNA METHYLATION CHANGES IN WHOLE BLOOD AND CD16+ NEUTROPHILS IN RESPONSE TO CHRONIC FOLIC ACID SUPPLEMENTATION IN WOMEN OF CHILDBEARING AGE. FOLATE, A WATER-SOLUBLE VITAMIN, IS A KEY SOURCE OF ONE-CARBON GROUPS FOR DNA METHYLATION, BUT STUDIES OF THE DNA METHYLATION RESPONSE TO SUPPLEMENTAL FOLIC ACID YIELD INCONSISTENT RESULTS. THESE STUDIES ARE COMMONLY CONDUCTED USING WHOLE BLOOD, WHICH CONTAINS A MIXED POPULATION OF WHITE BLOOD CELLS THAT HAVE BEEN SHOWN TO CONFOUND RESULTS. THE OBJECTIVE OF THIS STUDY WAS TO DETERMINE IF CD16+ NEUTROPHILS MAY PROVIDE MORE SPECIFIC DATA THAN WHOLE BLOOD FOR IDENTIFYING DNA METHYLATION RESPONSE TO CHRONIC FOLIC ACID SUPPLEMENTATION. THE STUDY WAS PERFORMED IN NORMAL WEIGHT (BMI 18.5 - 24.9 KG/M2) WOMEN (18 - 35 Y; N = 12), WITH BLOOD SAMPLES TAKEN BEFORE AND AFTER 8 WEEKS OF FOLIC ACID SUPPLEMENTATION AT 800 MUG/DAY. DNA METHYLATION PATTERNS FROM WHOLE BLOOD AND ISOLATED CD16+ NEUTROPHILS WERE MEASURED ACROSS >485,000 CPG SITES THROUGHOUT THE GENOME USING THE INFINIUM HUMANMETHYLATION450 BEADCHIP. OVER THE COURSE OF THE 8-WEEK SUPPLEMENTATION, 6746 AND 7513 CPG SITES CHANGED (P < 0.05) IN WHOLE BLOOD AND CD16+ NEUTROPHILS, RESPECTIVELY. DNA METHYLATION DECREASED IN 68.4% (WHOLE BLOOD) AND 71.8% (CD16+ NEUTROPHILS) OF THESE SITES. THERE WERE ONLY 182 CPG SITES THAT CHANGED IN BOTH THE WHOLE BLOOD AND CD16+ NEUTROPHILS, 139 OF WHICH CHANGED IN THE SAME DIRECTION. THESE RESULTS SUGGEST THAT THE GENOME-WIDE DNA METHYLATION RESPONSE TO CHRONIC FOLIC ACID SUPPLEMENTATION IS DIFFERENT BETWEEN WHOLE BLOOD AND CD16+ NEUTROPHILS AND THAT A SINGLE WHITE BLOOD CELL TYPE MAY FUNCTION AS A MORE SPECIFIC EPIGENETIC REPORTER OF FOLATE STATUS THAN WHOLE BLOOD. 2017 4 6190 52 THE IMPACT OF METHYLATION QUANTITATIVE TRAIT LOCI (MQTLS) ON ACTIVE SMOKING-RELATED DNA METHYLATION CHANGES. BACKGROUND: METHYLATION QUANTITATIVE TRAIT LOCI (MQTLS) ARE THE GENETIC VARIANTS THAT MAY AFFECT THE DNA METHYLATION PATTERNS OF CPG SITES. HOWEVER, THEIR ROLES IN INFLUENCING THE DISTURBANCES OF SMOKING-RELATED EPIGENETIC CHANGES HAVE NOT BEEN WELL ESTABLISHED. THIS STUDY WAS CONDUCTED TO ADDRESS WHETHER MQTLS EXIST IN THE VICINITY OF SMOKING-RELATED CPG SITES (+/- 50 KB) AND TO EXAMINE THEIR ASSOCIATIONS WITH SMOKING EXPOSURE AND ALL-CAUSE MORTALITY IN OLDER ADULTS. RESULTS: WE OBTAINED DNA METHYLATION PROFILES IN WHOLE BLOOD SAMPLES BY ILLUMINA INFINIUM HUMAN METHYLATION 450 BEADCHIP ARRAY OF TWO INDEPENDENT SUBSAMPLES OF THE ESTHER STUDY (DISCOVERY SET, N = 581; VALIDATION SET, N = 368) AND THEIR CORRESPONDING GENOTYPING DATA USING THE ILLUMINA INFINIUM ONCOARRAY BEADCHIP. AFTER CORRECTION FOR MULTIPLE TESTING (FDR), WE SUCCESSFULLY IDENTIFIED THAT 70 OUT OF 151 PREVIOUSLY REPORTED SMOKING-RELATED CPG SITES WERE SIGNIFICANTLY ASSOCIATED WITH 192 SNPS WITHIN THE 50 KB SEARCH WINDOW OF EACH LOCUS. THE 192 MQTLS SIGNIFICANTLY INFLUENCED THE ACTIVE SMOKING-RELATED DNA METHYLATION CHANGES, WITH PERCENTAGE CHANGES RANGING FROM 0.01 TO 18.96%, ESPECIALLY FOR THE WEAKLY/MODERATELY SMOKING-RELATED CPG SITES. HOWEVER, THESE IDENTIFIED MQTLS WERE NOT DIRECTLY ASSOCIATED WITH ACTIVE SMOKING EXPOSURE OR ALL-CAUSE MORTALITY. CONCLUSIONS: OUR FINDINGS CLEARLY DEMONSTRATED THAT IF NOT DEALT WITH PROPERLY, THE MQTLS MIGHT IMPAIR THE POWER OF EPIGENETIC-BASED MODELS OF SMOKING EXPOSURE TO A CERTAIN EXTENT. IN ADDITION, SUCH GENETIC VARIANTS COULD BE THE KEY FACTOR TO DISTINGUISH BETWEEN THE HERITABLE AND SMOKING-INDUCED IMPACT ON EPIGENOME DISPARITIES. THESE MQTLS ARE OF SPECIAL IMPORTANCE WHEN DNA METHYLATION MARKERS MEASURED BY ILLUMINA INFINIUM ASSAY ARE USED FOR ANY COMPARATIVE POPULATION STUDIES RELATED TO SMOKING-RELATED CANCERS AND CHRONIC DISEASES. 2017 5 1485 31 DMRFUSION: A DIFFERENTIALLY METHYLATED REGION DETECTION TOOL BASED ON THE RANKED FUSION METHOD. DNA METHYLATION IS AN IMPORTANT EPIGENETIC MODIFICATION INVOLVED IN MANY BIOLOGICAL PROCESSES AND DISEASES. COMPUTATIONAL ANALYSIS OF DIFFERENTIALLY METHYLATED REGIONS (DMRS) COULD EXPLORE THE UNDERLYING REASONS OF METHYLATION. DMRFUSION IS PRESENTED AS A USEFUL TOOL FOR COMPREHENSIVE DNA METHYLATION ANALYSIS OF DMRS ON METHYLATION SEQUENCING DATA. THIS TOOL IS DESIGNED BASE ON THE INTEGRATION OF SEVERAL RANKING METHODS; INFORMATION GAIN, BETWEEN VERSUS WITHIN CLASS SCATTER RATIO, FISHER RATIO, Z-SCORE AND WELCH'S T-TEST. IN THIS STUDY, DMRFUSION ON REDUCED REPRESENTATION BISULFITE SEQUENCING (RRBS) DATA IN CHRONIC LYMPHOCYTIC LEUKEMIA CANCER DISPLAYED 30 NOMINATED REGIONS AND CPG SITES WITH A MAXIMUM METHYLATION DIFFERENCE DETECTED IN THE HYPERMETHYLATION DMRS. WE REALIZED THAT DMRFUSION IS ABLE TO PROCESS METHYLATION SEQUENCING DATA IN AN EFFICIENT AND ACCURATE MANNER AND TO PROVIDE ANNOTATION AND VISUALIZATION FOR DMRS WITH HIGH FOLD DIFFERENCE SCORE (P-VALUE AND FDR<0.05 AND TYPE I ERROR: 0.04). 2018 6 1138 34 COMPUTATIONAL METHODS FOR DETECTION OF DIFFERENTIALLY METHYLATED REGIONS USING KERNEL DISTANCE AND SCAN STATISTICS. MOTIVATION: 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 SEQUENCE OF DNA. ABNORMAL DNA METHYLATION IS ASSOCIATED WITH MANY HUMAN DISEASES. RESULTS: WE PROPOSE TWO DIFFERENT APPROACHES TO TEST FOR DIFFERENTIALLY METHYLATED REGIONS (DMRS) ASSOCIATED WITH COMPLEX TRAITS, WHILE ACCOUNTING FOR CORRELATIONS AMONG CPG SITES IN THE DMRS. THE FIRST APPROACH IS A NONPARAMETRIC METHOD USING A KERNEL DISTANCE STATISTIC AND THE SECOND ONE IS A LIKELIHOOD-BASED METHOD USING A BINOMIAL SPATIAL SCAN STATISTIC. THE KERNEL DISTANCE METHOD USES THE KERNEL FUNCTION, WHILE THE BINOMIAL SCAN STATISTIC APPROACH USES A MIXED-EFFECTS MODEL TO INCORPORATE CORRELATIONS AMONG CPG SITES. EXTENSIVE SIMULATIONS SHOW THAT BOTH APPROACHES HAVE EXCELLENT CONTROL OF TYPE I ERROR, AND BOTH HAVE REASONABLE STATISTICAL POWER. THE BINOMIAL SCAN STATISTIC APPROACH APPEARS TO HAVE HIGHER POWER, WHILE THE KERNEL DISTANCE METHOD IS COMPUTATIONALLY FASTER. THE PROPOSED METHODS ARE DEMONSTRATED USING DATA FROM A CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) STUDY. 2019 7 3073 56 GENOME-WIDE DNA METHYLATION STATUS OF MONGOLIANS EXHIBITS SIGNS OF CELLULAR STRESS RESPONSE RELATED TO THEIR NOMADIC LIFESTYLE. BACKGROUND: EPIGENETICS IS CRUCIAL FOR CONNECTING ENVIRONMENTAL STRESSES WITH PHYSIOLOGICAL RESPONSES IN HUMANS. MONGOLIA, WHERE NOMADIC LIVESTOCK PASTORALISM HAS BEEN THE PRIMAL LIVELIHOOD, HAS A HIGHER PREVALENCE OF VARIOUS CHRONIC DISEASES THAN THE SURROUNDING EAST ASIAN REGIONS, WHICH ARE MORE SUITABLE FOR CROP FARMING. THE GENES RELATED TO DIETARY STRESS AND PATHOGENESIS OF RELATED DISORDERS MAY HAVE VARYING EPIGENETIC STATUSES AMONG THE HUMAN POPULATIONS WITH DIVERSE DIETARY CULTURES. HENCE, TO UNDERSTAND SUCH EPIGENETIC DIFFERENCES, WE CONDUCTED A COMPARATIVE ANALYSIS OF GENOME-WIDE DNA METHYLATION OF MONGOLIANS AND CROP-FARMING EAST ASIANS. METHODS: GENOME-WIDE DNA METHYLATION STATUS OF PERIPHERAL BLOOD CELLS (PBCS) FROM 23 MONGOLIAN ADULTS AND 24 THAI ADULTS WAS DETERMINED USING THE INFINIUM HUMAN METHYLATION 450K ARRAYS AND ANALYZED IN COMBINATION WITH PREVIOUSLY PUBLISHED 450K DATA OF 20 JAPANESE AND 8 CHINESE ADULTS. CPG SITES/REGIONS DIFFERENTIALLY METHYLATED BETWEEN MONGOLIANS AND CROP-FARMING EAST ASIANS WERE DETECTED USING A LINEAR MODEL ADJUSTED FOR SEX, AGE, ETHNICITY, AND IMMUNE CELL HETEROGENEITY ON RNBEADS SOFTWARE. RESULTS: OF THE QUALITY-CONTROLLED 389,454 AUTOSOMAL CPG SITES, 223 CPG SITES WERE SIGNIFICANTLY DIFFERENTIALLY METHYLATED AMONG MONGOLIANS AND THE FOUR CROP FARMING EAST ASIAN POPULATIONS (FALSE DISCOVERY RATE < 0.05). ANALYSES FOCUSED ON GENE PROMOTER REGIONS REVEALED THAT PM20D1 (PEPTIDASE M20 DOMAIN CONTAINING 1), WHICH IS INVOLVED IN MITOCHONDRIAL UNCOUPLING AND VARIOUS PROCESSES, INCLUDING CELLULAR PROTECTION FROM REACTIVE OXYGEN SPECIES (ROS) AND THERMOGENESIS, WAS THE TOP DIFFERENTIALLY METHYLATED GENE. MOREOVER, GENE ONTOLOGY ENRICHMENT ANALYSIS REVEALED THAT BIOLOGICAL PROCESSES RELATED TO ROS METABOLISM WERE OVERREPRESENTED AMONG THE TOP 1% DIFFERENTIALLY METHYLATED GENES. THE PROMOTER REGIONS OF THESE GENES WERE GENERALLY HYPERMETHYLATED IN MONGOLIANS, SUGGESTING THAT THE METABOLIC PATHWAY DETOXIFYING ROS MIGHT BE GLOBALLY SUPPRESSED IN MONGOLIANS, RESULTING IN THE HIGH SUSCEPTIBILITY OF THIS POPULATION TO VARIOUS CHRONIC DISEASES. CONCLUSIONS: THIS STUDY SHOWED A SIGNIFICANTLY DIVERSE DNA METHYLATION STATUS AMONG MONGOLIANS AND CROP-FARMING EAST ASIANS. FURTHER, WE FOUND AN ASSOCIATION BETWEEN THE DIFFERENTIALLY METHYLATED GENES AND VARIOUS METABOLIC AND NEURODEGENERATIVE DISEASES. KNOWLEDGE OF THE EPIGENETIC REGULATORS MIGHT HELP IN PROPER UNDERSTANDING, TREATMENT, AND CONTROL OF SUCH DISORDERS, AND PHYSIOLOGICAL ADAPTATION IN THE FUTURE. 2022 8 5092 38 PLACENTAL EPIGENETIC MARKS RELATED TO GESTATIONAL WEIGHT GAIN REVEAL POTENTIAL GENES ASSOCIATED WITH OFFSPRING OBESITY PARAMETERS. OBJECTIVE: OFFSPRING EXPOSED TO GESTATIONAL OBESITY HAVE AN INCREASED RISK FOR CHRONIC DISEASES. INCREASING EVIDENCE SUGGESTS THAT EPIGENETICS MAY PLAY A MECHANISTIC ROLE IN METABOLIC PROGRAMMING. THIS STUDY AIMED TO IDENTIFY PLACENTAL DNA METHYLATION MARKS ASSOCIATED WITH GESTATIONAL WEIGHT GAIN (GWG) AND TO STUDY THEIR ASSOCIATION WITH OFFSPRING OBESITY PARAMETERS AT SCHOOL AGE. METHODS: A GLOBAL METHYLATION ARRAY WAS PERFORMED IN 24 PLACENTAS FROM MOTHERS WITH DIFFERENT DEGREES OF GWG (SCREENING SAMPLE). THE METHYLATION PERCENTAGE OF FOUR CYTOSINE-GUANINE (CPG) SITES AND THE RELATIVE EXPRESSION OF THE RESPECTIVE ANNOTATED GENES WERE STUDIED IN 90 ADDITIONAL PLACENTAS (VALIDATION SAMPLE). ASSOCIATIONS OF THESE EPIGENETIC MARKS WITH CLINICAL PARAMETERS IN THE OFFSPRING AT 6 YEARS OF AGE WERE EXAMINED. RESULTS: THE SCREENING ANALYSIS IDENTIFIED 104 CPG SITES (97 GENES) ASSOCIATED WITH GWG. THE VALIDATION ANALYSIS OF FOUR SELECTED CPG SITES (ANNOTATING FOR FRAT1, SNX5, AND KCNK3 GENES) SHOWED THAT THE UPREGULATION OF SNX5 METHYLATION, THE DOWNREGULATION OF FRAT1 METHYLATION, AND KCNK3 UNDEREXPRESSION ASSOCIATED WITH AN ADVERSE METABOLIC PHENOTYPE IN CHILDREN OF WOMEN WITH INCREASED GWG. CONCLUSIONS: THESE RESULTS SUGGEST THAT PLACENTAL REGULATION OF FRAT1, SNX5, AND KCNK3 RELATES TO OBESITY PARAMETERS IN OFFSPRING EXPOSED TO EXCESSIVE GWG AND THEREBY COULD CONDITION THE RISK FOR FUTURE METABOLIC DISORDERS. 2023 9 1990 38 EPIGENETIC ANALYSIS OF PAGET'S DISEASE OF BONE IDENTIFIES DIFFERENTIALLY METHYLATED LOCI THAT PREDICT DISEASE STATUS. PAGET'S DISEASE OF BONE (PDB) IS CHARACTERIZED BY FOCAL INCREASES IN DISORGANIZED BONE REMODELING. THIS STUDY AIMS TO CHARACTERIZE PDB-ASSOCIATED CHANGES IN DNA METHYLATION PROFILES IN PATIENTS' BLOOD. META-ANALYSIS OF DATA FROM THE DISCOVERY AND CROSS-VALIDATION SET, EACH COMPRISING 116 PDB CASES AND 130 CONTROLS, REVEALED SIGNIFICANT DIFFERENCES IN DNA METHYLATION AT 14 CPG SITES, 4 CPG ISLANDS, AND 6 GENE-BODY REGIONS. THESE LOCI, INCLUDING TWO CHARACTERIZED AS FUNCTIONAL THROUGH EXPRESSION QUANTITATIVE TRAIT-METHYLATION ANALYSIS, WERE ASSOCIATED WITH FUNCTIONS RELATED TO OSTEOCLAST DIFFERENTIATION, MECHANICAL LOADING, IMMUNE FUNCTION, AND VIRAL INFECTION. A MULTIVARIATE CLASSIFIER BASED ON DISCOVERY SAMPLES WAS FOUND TO DISCRIMINATE PDB CASES AND CONTROLS FROM THE CROSS-VALIDATION WITH A SENSITIVITY OF 0.84, SPECIFICITY OF 0.81, AND AN AREA UNDER CURVE OF 92.8%. IN CONCLUSION, THIS STUDY HAS SHOWN FOR THE FIRST TIME THAT EPIGENETIC FACTORS CONTRIBUTE TO THE PATHOGENESIS OF PDB AND MAY OFFER DIAGNOSTIC MARKERS FOR PREDICTION OF THE DISEASE. 2021 10 1590 32 DNA METHYLATION PROFILING IN HUMAN LUNG TISSUE IDENTIFIES GENES ASSOCIATED WITH COPD. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A SMOKING-RELATED DISEASE CHARACTERIZED BY GENETIC AND PHENOTYPIC HETEROGENEITY. ALTHOUGH ASSOCIATION STUDIES HAVE IDENTIFIED MULTIPLE GENOMIC REGIONS WITH REPLICATED ASSOCIATIONS TO COPD, GENETIC VARIATION ONLY PARTIALLY EXPLAINS THE SUSCEPTIBILITY TO LUNG DISEASE, AND SUGGESTS THE RELEVANCE OF EPIGENETIC INVESTIGATIONS. WE PERFORMED GENOME-WIDE DNA METHYLATION PROFILING IN HOMOGENIZED LUNG TISSUE SAMPLES FROM 46 CONTROL SUBJECTS WITH NORMAL LUNG FUNCTION AND 114 SUBJECTS WITH COPD, ALL FORMER SMOKERS. THE DIFFERENTIALLY METHYLATED LOCI WERE INTEGRATED WITH PREVIOUS GENOME-WIDE ASSOCIATION STUDY RESULTS. THE TOP 535 DIFFERENTIALLY METHYLATED SITES, FILTERED FOR A MINIMUM MEAN METHYLATION DIFFERENCE OF 5% BETWEEN CASES AND CONTROLS, WERE ENRICHED FOR CPG SHELVES AND SHORES. PATHWAY ANALYSIS REVEALED ENRICHMENT FOR TRANSCRIPTION FACTORS. THE TOP DIFFERENTIALLY METHYLATED SITES FROM THE INTERSECTION WITH PREVIOUS GWAS WERE IN CHRM1, GLT1D1, AND C10ORF11; SORTED BY GWAS P-VALUE, THE TOP SITES INCLUDED FRMD4A, THSD4, AND C10ORF11. EPIGENETIC ASSOCIATION STUDIES COMPLEMENT GENETIC ASSOCIATION STUDIES TO IDENTIFY GENES POTENTIALLY INVOLVED IN COPD PATHOGENESIS. ENRICHMENT FOR GENES IMPLICATED IN ASTHMA AND LUNG FUNCTION AND FOR TRANSCRIPTION FACTORS SUGGESTS THE POTENTIAL PATHOGENIC RELEVANCE OF GENES IDENTIFIED THROUGH DIFFERENTIAL METHYLATION AND THE INTERSECTION WITH A BROADER RANGE OF GWAS ASSOCIATIONS. 2016 11 4818 40 OCCURRENCE OF ACCELERATED EPIGENETIC AGING AND METHYLATION DISRUPTIONS IN HUMAN IMMUNODEFICIENCY VIRUS INFECTION BEFORE ANTIRETROVIRAL THERAPY. BACKGROUND: WHETHER ACCELERATED AGING DEVELOPS OVER THE COURSE OF CHRONIC HUMAN IMMUNODEFICIENCY VIRUS (HIV) INFECTION OR CAN BE OBSERVED BEFORE SIGNIFICANT IMMUNOSUPPRESSION ON IS UNKNOWN. WE STUDIED DNA METHYLATION IN BLOOD TO ESTIMATE CELLULAR AGING IN PERSONS LIVING WITH HIV (PLWH) BEFORE THE INITIATION OF ANTIRETROVIRAL THERAPY (ART). METHODS: A TOTAL OF 378 ART-NAIVE PLWH WHO HAD CD4 T-CELL COUNTS >500/MICROL AND WERE ENROLLED IN THE STRATEGIC TIMING OF ANTIRETROVIRAL THERAPY TRIAL (PULMONARY SUBSTUDY) WERE COMPARED WITH 34 HIV-NEGATIVE CONTROLS. DNA METHYLATION WAS PERFORMED USING THE ILLUMINA METHYLATIONEPIC BEADCHIP. DIFFERENTIALLY METHYLATED POSITIONS (DMPS) AND DIFFERENTIALLY METHYLATED REGIONS (DMRS) IN PLWH COMPARED WITH CONTROLS WERE IDENTIFIED USING A ROBUST LINEAR MODEL. METHYLATION AGE WAS CALCULATED USING A PREVIOUSLY DESCRIBED EPIGENETIC CLOCK. RESULTS: THERE WERE A TOTAL OF 56 639 DMPS AND 6103 DMRS AT A FALSE DISCOVERY RATE OF <0.1. THE TOP 5 DMPS CORRESPONDED TO GENES NLRC5, VRK2, B2M, AND GPR6 AND WERE HIGHLY ENRICHED FOR CANCER-RELATED PATHWAYS. PLWH HAD SIGNIFICANTLY HIGHER METHYLATION AGE THAN HIV-NEGATIVE CONTROLS (P = .001), WITH BLACK RACE, LOW CD4 AND HIGH CD8 T-CELL COUNTS, AND DURATION OF HIV BEING RISK FACTORS FOR AGE ACCELERATION. CONCLUSIONS: PLWH BEFORE THE INITIATION OF ART AND WITH PRESERVED IMMUNE STATUS SHOW EVIDENCE OF ADVANCED METHYLATION AGING. 2021 12 1607 40 DNA METHYLATION, COLON CANCER AND MEDITERRANEAN DIET: RESULTS FROM THE EPIC-ITALY COHORT. THE BIOLOGICAL MECHANISMS THROUGH WHICH ADHERENCE TO MEDITERRANEAN DIET (MD) PROTECTS AGAINST COLON CANCER (CC) ARE POORLY UNDERSTOOD. EVIDENCE SUGGESTS THAT CHRONIC INFLAMMATION MAY BE IMPLICATED IN THE PATHWAY. BOTH DIET AND CC ARE RELATED TO EPIGENETIC REGULATION. WE PERFORMED A NESTED CASE-CONTROL STUDY ON 161 PAIRS FROM THE ITALIAN COMPONENT OF THE EUROPEAN PROSPECTIVE INVESTIGATION INTO CANCER AND NUTRITION (EPIC) COHORT, IN WHICH WE LOOKED FOR THE METHYLATION SIGNALS IN DNA EXTRACTED FROM LEUCOCYTES ASSOCIATED WITH BOTH CC AND MD IN 995 CPGS LOCATED IN 48 INFLAMMATION GENES. THE DNA METHYLATION SIGNALS DETECTED IN THIS ANALYSIS WERE VALIDATED IN A SUBGROUP OF 47 CASE-CONTROL PAIRS AND FURTHER REPLICATED (WHERE VALIDATED) IN 95 NEW PAIRS BY MEANS OF PYROSEQUENCING. AMONG THE CPG SITES SELECTED A-PRIORI IN INFLAMMATION-RELATED GENES, SEVEN CPG SITES WERE FOUND TO BE ASSOCIATED WITH CC STATUS AND WITH MD, IN LINE WITH ITS PROTECTIVE EFFECT. ONLY TWO CPG SITES (CG17968347-SERPINE1 AND CG20674490-RUNX3) WERE VALIDATED USING BISULPHITE PYROSEQUENCING AND, AFTER REPLICATION, WE FOUND THAT DNA METHYLATION OF CG20674490-RUNX3 MAY BE A POTENTIAL MOLECULAR MEDIATOR EXPLAINING THE PROTECTIVE EFFECT OF MD ON CC ONSET. THE USE OF A 'MEET-IN-THE-MIDDLE' APPROACH TO IDENTIFY THE OVERLAP BETWEEN EXPOSURE AND PREDICTIVE MARKERS OF DISEASE IS INNOVATIVE IN STUDIES ON THE RELATIONSHIP BETWEEN DIET AND CANCER, IN WHICH EXPOSURE ASSESSMENT IS DIFFICULT AND THE MECHANISMS THROUGH WHICH THE NUTRIENTS EXERT THEIR PROTECTIVE EFFECT IS LARGELY UNKNOWN. 2019 13 5883 37 SYSTEMIC AND AIRWAY EPIGENETIC DISRUPTIONS ARE ASSOCIATED WITH HEALTH STATUS IN COPD. EPIGENETIC MODIFICATIONS ARE COMMON IN CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD); HOWEVER, THEIR CLINICAL RELEVANCE IS LARGELY UNKNOWN. WE HYPOTHESIZED THAT EPIGENETIC DISRUPTIONS ARE ASSOCIATED WITH SYMPTOMS AND HEALTH STATUS IN COPD. WE PROFILED THE BLOOD (N = 57) AND AIRWAYS (N = 62) OF COPD PATIENTS FOR DNA METHYLATION (N = 55 PAIRED). THE PATIENTS' HEALTH STATUS WAS ASSESSED USING THE ST. GEORGE'S RESPIRATORY QUESTIONNAIRE (SGRQ). WE CONDUCTED DIFFERENTIAL METHYLATION ANALYSES AND IDENTIFIED PATHWAYS CHARACTERIZED BY EPIGENETIC DISRUPTIONS ASSOCIATED WITH SGRQ SCORES AND ITS INDIVIDUAL DOMAINS. 29,211 AND 5044 DIFFERENTIALLY METHYLATED POSITIONS (DMPS) WERE ASSOCIATED WITH TOTAL SGRQ SCORES IN BLOOD AND AIRWAY SAMPLES, RESPECTIVELY. THE ACTIVITY, IMPACT, AND SYMPTOM DOMAINS WERE ASSOCIATED WITH 9161, 25,689 AND 17,293 DMPS IN BLOOD, RESPECTIVELY; AND 4674, 3730 AND 5063 DMPS IN AIRWAYS, RESPECTIVELY. THERE WAS A SUBSTANTIAL OVERLAP OF DMPS BETWEEN AIRWAY AND BLOOD. DMPS WERE ENRICHED FOR PATHWAYS RELATED TO COMMON CO-MORBIDITIES OF COPD (E.G., AGEING, CANCER AND NEUROLOGICAL) IN BOTH TISSUES. HEALTH STATUS IN COPD IS ASSOCIATED WITH AIRWAY AND SYSTEMIC EPIGENETIC CHANGES ESPECIALLY IN PATHWAYS RELATED TO CO-MORBIDITIES OF COPD. THERE ARE MORE BLOOD DMPS THAN IN THE AIRWAYS SUGGESTING THAT BLOOD EPIGENOME IS A PROMISING SOURCE TO DISCOVER BIOMARKERS FOR CLINICAL OUTCOMES IN COPD. 2023 14 3125 28 GHSR DNA HYPERMETHYLATION IS A COMMON EPIGENETIC ALTERATION OF HIGH DIAGNOSTIC VALUE IN A BROAD SPECTRUM OF CANCERS. IDENTIFICATION OF A SINGLE MOLECULAR TRAIT THAT IS DETERMINANT OF COMMON MALIGNANCIES MAY SERVE AS A POWERFUL DIAGNOSTIC SUPPLEMENT TO CANCER TYPE-SPECIFIC MARKERS. HERE, WE REPORT A DNA METHYLATION MARK THAT IS CHARACTERISTIC OF SEVEN STUDIED MALIGNANCIES, NAMELY CANCERS OF LUNG, BREAST, PROSTATE, PANCREAS, COLORECTUM, GLIOBLASTOMA AND B CELL CHRONIC LYMPHOCYTIC LEUKAEMIA (CLL) (N = 137). THIS MARK WAS DEFINED BY SUBSTANTIAL HYPERMETHYLATION AT THE PROMOTER AND FIRST EXON OF GROWTH HORMONE SECRETAGOUGE RECEPTOR (GHSR) THROUGH BISULFITE PYROSEQUENCING. THE DEGREE OF ABERRANT METHYLATION WAS CAPABLE OF ACCURATE DISCRIMINATION BETWEEN CANCER AND CONTROL SAMPLES. THE HIGHEST SENSITIVITY AND SPECIFICITY OF CANCER DETECTION WAS ACHIEVED FOR CANCERS OF PANCREAS, LUNG, BREAST AND CLL YIELDING THE AREA UNDER THE CURVE (AUC) VALUES OF 1.0000, 0.9952, 0.9800 AND 0.9400, RESPECTIVELY. NARROWING TO A SINGLE CPG SITE WITHIN THE GENE'S PROMOTER OR FOUR CONSECUTIVE CPG UNITS OF THE HIGHEST METHYLATION LEVELS WITHIN THE FIRST EXON IMPROVED THE DETECTION POWER. GHSR HYPERMETHYLATION WAS DETECTED ALREADY AT THE EARLY STAGE TUMORS. THE ACCURATE PERFORMANCE OF THIS MARKER WAS FURTHER REPLICATED IN AN INDEPENDENT SET OF PANCREATIC CANCER AND CONTROL SAMPLES (N = 78). THESE FINDINGS SUPPORT THE CANDIDATURE OF GHSR METHYLATION AS A HIGHLY ACCURATE PAN-CANCER MARKER. 2015 15 3951 68 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 16 4750 33 NOVEL REGIONAL AGE-ASSOCIATED DNA METHYLATION CHANGES WITHIN HUMAN COMMON DISEASE-ASSOCIATED LOCI. BACKGROUND: ADVANCING AGE PROGRESSIVELY IMPACTS ON RISK AND SEVERITY OF CHRONIC DISEASE. IT ALSO MODIFIES THE EPIGENOME, WITH CHANGES IN DNA METHYLATION, DUE TO BOTH RANDOM DRIFT AND VARIATION WITHIN SPECIFIC FUNCTIONAL LOCI. RESULTS: IN A DISCOVERY SET OF 2238 PERIPHERAL-BLOOD GENOME-WIDE DNA METHYLOMES AGED 19-82 YEARS, WE IDENTIFY 71 AGE-ASSOCIATED DIFFERENTIALLY METHYLATED REGIONS WITHIN THE LINKAGE DISEQUILIBRIUM BLOCKS OF THE SINGLE NUCLEOTIDE POLYMORPHISMS FROM THE NIH GENOME-WIDE ASSOCIATION STUDY CATALOGUE. THIS INCLUDED 52 NOVEL REGIONS, 29 WITHIN LOCI NOT COVERED BY 450 K OR 27 K ILLUMINA ARRAY, AND WITH ENRICHMENT FOR DNASE-I HYPERSENSITIVITY SITES ACROSS THE FULL RANGE OF TISSUES. THESE AGE-ASSOCIATED DIFFERENTIALLY METHYLATED REGIONS ALSO SHOW MARKED ENRICHMENT FOR ENHANCERS AND POISED PROMOTERS ACROSS MULTIPLE CELL TYPES. IN A REPLICATION SET OF 2084 DNA METHYLOMES, 95.7 % OF THE AGE-ASSOCIATED DIFFERENTIALLY METHYLATED REGIONS SHOWED THE SAME DIRECTION OF AGEING EFFECT, WITH 80.3 % AND 53.5 % REPLICATED TO P < 0.05 AND P < 1.85 X 10(-8), RESPECTIVELY. CONCLUSION: BY ANALYSING THE FUNCTIONALLY ENRICHED DISEASE AND TRAIT-ASSOCIATED REGIONS OF THE HUMAN GENOME, WE IDENTIFY NOVEL EPIGENETIC AGEING CHANGES, WHICH COULD BE USEFUL BIOMARKERS OR PROVIDE MECHANISTIC INSIGHTS INTO AGE-RELATED COMMON DISEASES. 2016 17 5070 38 PHYSICAL ACTIVITY, TELEVISION VIEWING TIME, AND DNA METHYLATION IN PERIPHERAL BLOOD. INTRODUCTION: PHYSICAL ACTIVITY MAY AFFECT HEALTH VIA DNA METHYLATION. THE EPIGENETIC INFLUENCES OF SEDENTARY BEHAVIORS SUCH AS TELEVISION VIEWING ARE UNKNOWN. WE PERFORMED A GENOMEWIDE STUDY OF DNA METHYLATION IN PERIPHERAL BLOOD IN RELATION TO PHYSICAL ACTIVITY AND TELEVISION VIEWING TIME. METHODS: DNA METHYLATION WAS MEASURED USING THE ILLUMINA INFINIUM HUMANMETHYLATION450K BEADCHIP ARRAY IN BLOOD SAMPLES COLLECTED AT BASELINE (N = 5513) AND FOLLOW-UP (N = 1249) FROM PARTICIPANTS IN THE MELBOURNE COLLABORATIVE COHORT STUDY. AT BASELINE, TIMES PER WEEK OF LEISURE-TIME PHYSICAL ACTIVITY WERE SELF-REPORTED. AT FOLLOW-UP, THE INTERNATIONAL PHYSICAL ACTIVITY QUESTIONNAIRE WAS USED TO ASSESS MET-HOURS PER WEEK OF TOTAL AND LEISURE-TIME PHYSICAL ACTIVITY AND HOURS PER DAY OF TELEVISION VIEWING TIME. LINEAR MIXED MODELS WERE USED TO ASSESS ASSOCIATIONS BETWEEN PHYSICAL ACTIVITY AND TELEVISION VIEWING MEASURES AND DNA METHYLATION AT INDIVIDUAL CPG SITES, ADJUSTED FOR POTENTIAL CONFOUNDERS AND BATCH EFFECTS. RESULTS: AT FOLLOW-UP, TOTAL PHYSICAL ACTIVITY WAS ASSOCIATED WITH DNA METHYLATION AT CG10266336 (P = 6.0 X 10), ANNOTATED TO THE SAA2 GENE. WEAKER EVIDENCE OF ASSOCIATIONS (P < 1.0 X 10) WERE OBSERVED FOR AN ADDITIONAL 14 CPG SITES WITH TOTAL PHYSICAL ACTIVITY, FOR 7 CPG SITES WITH LEISURE-TIME PHYSICAL ACTIVITY, AND FOR 9 CPG SITES WITH TELEVISION VIEWING TIME. CHANGES IN LEISURE-TIME PHYSICAL ACTIVITY BETWEEN BASELINE AND FOLLOW-UP WERE ASSOCIATED WITH METHYLATION CHANGES (P < 0.05) AT FOUR OF THE SEVEN CPG SITES WITH WEAKER EVIDENCE OF CROSS-SECTIONAL ASSOCIATIONS WITH LEISURE-TIME PHYSICAL ACTIVITY. CONCLUSION: PHYSICAL ACTIVITY AND TELEVISION VIEWING MAY BE ASSOCIATED WITH BLOOD DNA METHYLATION, A POTENTIAL PATHWAY TO CHRONIC DISEASE DEVELOPMENT. FURTHER RESEARCH USING ACCELEROMETER DATA AND LARGER SAMPLE SIZES IS WARRANTED. 2019 18 1846 35 EFFECTS OF TWO TYPES OF ENERGY RESTRICTION ON METHYLATION LEVELS OF ADIPONECTIN RECEPTOR 1 AND LEPTIN RECEPTOR OVERLAPPING TRANSCRIPT IN A MOUSE MAMMARY TUMOUR VIRUS-TRANSFORMING GROWTH FACTOR-ALPHA BREAST CANCER MOUSE MODEL. THE ROLE OF ADIPONECTIN AND LEPTIN SIGNALLING PATHWAYS HAS BEEN SUGGESTED TO PLAY IMPORTANT ROLES IN THE PROTECTIVE EFFECTS OF ENERGY RESTRICTION (ER) ON MAMMARY TUMOUR (MT) DEVELOPMENT. TO STUDY THE EFFECTS OF ER ON THE METHYLATION LEVELS IN ADIPONECTIN RECEPTOR 1 (ADIPOR1) AND LEPTIN RECEPTOR OVERLAPPING TRANSCRIPT (LEPROT) GENES USING THE PYROSEQUENCING METHOD IN MAMMARY FAT PAD TISSUE, MOUSE MAMMARY TUMOUR VIRUS-TRANSFORMING GROWTH FACTOR-ALPHA (MMTV-TGF-ALPHA) FEMALE MICE WERE RANDOMLY ASSIGNED TO AD LIBITUM (AL), CHRONIC ER (CER, 15 % ER) OR INTERMITTENT ER (3 WEEKS AL AND 1 WEEK 60 % ER IN CYCLIC PERIODS) GROUPS AT 10 WEEKS OF AGE UNTIL 82 WEEKS OF AGE. THE METHYLATION LEVELS OF ADIPOR1 IN THE CER GROUP WERE HIGHER THAN THOSE IN THE AL GROUP AT WEEK 49/50 (P < 0.05), WHILE THE LEVELS OF METHYLATION FOR ADIPOR1 AND LEPROT GENES WERE SIMILAR AMONG THE OTHER GROUPS. ALSO, THE METHYLATION LEVELS AT CPG2 AND CPG3 REGIONS OF THE PROMOTER REGION OF THE ADIPOR1 GENE IN THE CER GROUP WERE THREE TIMES HIGHER (P < 0.05), WHILE CPG1 ISLAND OF LEPROT METHYLATION WAS SIGNIFICANTLY LOWER COMPARED WITH THE OTHER GROUPS (P < 0.05). ADIPONECTIN AND LEPTIN GENE EXPRESSION LEVELS WERE CONSISTENT WITH THE METHYLATION LEVELS. WE ALSO OBSERVED A CHANGE WITH AGEING IN METHYLATION LEVELS OF THESE GENES. THESE RESULTS INDICATE THAT DIFFERENT TYPES OF ER MODIFY METHYLATION LEVELS OF ADIPOR1 AND LEPROT IN DIFFERENT WAYS AND CER HAD A MORE SIGNIFICANT EFFECT ON METHYLATION LEVELS OF BOTH GENES. EPIGENETIC REGULATION OF THESE GENES MAY PLAY IMPORTANT ROLES IN THE PREVENTIVE EFFECTS OF ER AGAINST MT DEVELOPMENT AND AGEING PROCESSES. 2021 19 2627 49 EPIGENOME-WIDE ASSOCIATION STUDY OF ADIPOSITY AND FUTURE RISK OF OBESITY-RELATED DISEASES. BACKGROUND: OBESITY IS AN ESTABLISHED RISK FACTOR FOR SEVERAL COMMON CHRONIC DISEASES SUCH AS BREAST AND COLORECTAL CANCER, METABOLIC AND CARDIOVASCULAR DISEASES; HOWEVER, THE BIOLOGICAL BASIS FOR THESE RELATIONSHIPS IS NOT FULLY UNDERSTOOD. TO EXPLORE THE ASSOCIATION OF OBESITY WITH THESE CONDITIONS, WE INVESTIGATED PERIPHERAL BLOOD LEUCOCYTE (PBL) DNA METHYLATION MARKERS FOR ADIPOSITY AND THEIR CONTRIBUTION TO RISK OF INCIDENT BREAST AND COLORECTAL CANCER AND MYOCARDIAL INFARCTION. METHODS: DNA METHYLATION PROFILES (ILLUMINA INFINIUM((R)) HUMANMETHYLATION450 BEADCHIP) FROM 1941 INDIVIDUALS FROM FOUR POPULATION-BASED EUROPEAN COHORTS WERE ANALYSED IN RELATION TO BODY MASS INDEX, WAIST CIRCUMFERENCE, WAIST-HIP AND WAIST-HEIGHT RATIO WITHIN A META-ANALYTICAL FRAMEWORK. IN A SUBSET OF THESE INDIVIDUALS, DATA ON GENOME-WIDE GENE EXPRESSION LEVEL, BIOMARKERS OF GLUCOSE AND LIPID METABOLISM WERE ALSO AVAILABLE. VALIDATION OF METHYLATION MARKERS ASSOCIATED WITH ALL ADIPOSITY MEASURES WAS PERFORMED IN 358 INDIVIDUALS. FINALLY, WE INVESTIGATED THE ASSOCIATION OF OBESITY-RELATED METHYLATION MARKS WITH BREAST, COLORECTAL CANCER AND MYOCARDIAL INFARCTION WITHIN RELEVANT SUBSETS OF THE DISCOVERY POPULATION. RESULTS: WE IDENTIFIED 40 CPG LOCI WITH METHYLATION LEVELS ASSOCIATED WITH AT LEAST ONE ADIPOSITY MEASURE. OF THESE, ONE CPG LOCUS (CG06500161) IN ABCG1 WAS ASSOCIATED WITH ALL FOUR ADIPOSITY MEASURES (P = 9.07X10(-)(8) TO 3.27X10(-18)) AND LOWER TRANSCRIPTIONAL ACTIVITY OF THE FULL-LENGTH ISOFORM OF ABCG1 (P = 6.00X10(-7)), HIGHER TRIGLYCERIDE LEVELS (P = 5.37X10(-)(9)) AND HIGHER TRIGLYCERIDES-TO-HDL CHOLESTEROL RATIO (P = 1.03X10(-10)). OF THE 40 INFORMATIVE AND OBESITY-RELATED CPG LOCI, TWO (IN IL2RB AND FGF18) WERE SIGNIFICANTLY ASSOCIATED WITH COLORECTAL CANCER (INVERSELY, P < 1.6X10(-3)) AND ONE INTERGENIC LOCUS ON CHROMOSOME 1 WAS INVERSELY ASSOCIATED WITH MYOCARDIAL INFARCTION (P < 1.25X10(-3)), INDEPENDENTLY OF OBESITY AND ESTABLISHED RISK FACTORS. CONCLUSION: OUR RESULTS SUGGEST THAT EPIGENETIC CHANGES, IN PARTICULAR ALTERED DNA METHYLATION PATTERNS, MAY BE AN INTERMEDIATE BIOMARKER AT THE INTERSECTION OF OBESITY AND OBESITY-RELATED DISEASES, AND COULD OFFER CLUES AS TO UNDERLYING BIOLOGICAL MECHANISMS. 2018 20 6080 42 THE EFFECT OF DNA METHYLATION IN THE DEVELOPMENT AND PROGRESSION OF CHRONIC KIDNEY DISEASE IN THE GENERAL POPULATION: AN EPIGENOME-WIDE ASSOCIATION STUDY USING THE KOREAN GENOME AND EPIDEMIOLOGY STUDY DATABASE. BACKGROUND: ALTHOUGH KNOWLEDGE OF THE GENETIC FACTORS INFLUENCING KIDNEY DISEASE IS INCREASING, EPIGENETIC PROFILES, WHICH ARE ASSOCIATED WITH CHRONIC KIDNEY DISEASE (CKD), HAVE NOT BEEN FULLY ELUCIDATED. WE SOUGHT TO IDENTIFY THE DNA METHYLATION STATUS OF CPG SITES ASSOCIATED WITH REDUCED KIDNEY FUNCTION AND EXAMINE WHETHER THE IDENTIFIED CPG SITES ARE ASSOCIATED WITH CKD DEVELOPMENT. METHOD: WE ANALYZED DNA METHYLATION PATTERNS OF 440 PARTICIPANTS IN THE KOREAN GENOME AND EPIDEMIOLOGY STUDY (KOGES) WITH ESTIMATED GLOMERULAR FILTRATION RATES (EGFRS) >/= 60 ML/MIN/1.73 M(2) AT BASELINE. CKD DEVELOPMENT WAS DEFINED AS A DECREASE IN THE EGFR OF <60 AT ANY TIME DURING AN 8-YEAR FOLLOW-UP PERIOD ("CKD PREDICTION" ANALYSIS). IN ADDITION, AMONG THE 440 PARTICIPANTS, 49 PARTICIPANTS WHO UNDERWENT A SECOND METHYLATION PROFILING WERE ASSESSED FOR AN ASSOCIATION BETWEEN A DECLINE IN KIDNEY FUNCTION AND CHANGES IN THE DEGREE OF METHYLATION OF CPG SITES DURING THE 8 YEARS ("KIDNEY FUNCTION SLOPE" ANALYSIS). RESULTS: IN THE CKD PREDICTION ANALYSIS, METHYLATION PROFILES OF A TOTAL OF 403,129 CPG SITES WERE EVALUATED AT BASELINE IN 440 PARTICIPANTS, AND INCREASED AND DECREASED METHYLATION OF 268 AND 189 CPG SITES, RESPECTIVELY, WERE SIGNIFICANTLY CORRELATED WITH THE DEVELOPMENT OF CKD IN MULTIVARIABLE LOGISTIC REGRESSION. DURING KIDNEY FUNCTION SLOPE ANALYSIS USING FOLLOW-UP METHYLATION PROFILES OF 49 PARTICIPANTS, THE PERCENT METHYLATION CHANGES IN 913 CPG SITES SHOWED A LINEAR RELATIONSHIP WITH THE PERCENT CHANGE IN EGFR DURING 8 YEARS. DURING FUNCTIONAL ENRICHMENT ANALYSES FOR SIGNIFICANT CPG SITES FOUND IN THE CKD PREDICTION AND KIDNEY FUNCTION SLOPE ANALYSES, WE FOUND THAT THOSE CPG SITES REPRESENTED MAPK, PI3K/AKT, AND RAP1 PATHWAYS. IN ADDITION, THREE CPG SITES FROM THREE GENES, NPHS2, CHCHD4, AND AHR, WERE FOUND TO BE SIGNIFICANT IN THE CKD PREDICTION ANALYSIS AND RELATED TO A DECLINE IN KIDNEY FUNCTION. CONCLUSION: IT IS SUGGESTED THAT DNA METHYLATION ON SPECIFIC GENES IS ASSOCIATED WITH THE DEVELOPMENT OF CKD AND THE DETERIORATION OF KIDNEY FUNCTION. 2023