1 1576 127 DNA METHYLATION PROFILE ASSOCIATED WITH RAPID DECLINE IN KIDNEY FUNCTION: FINDINGS FROM THE CRIC STUDY. BACKGROUND: EPIGENETIC MECHANISMS MAY BE IMPORTANT IN THE PROGRESSION OF CHRONIC KIDNEY DISEASE (CKD). METHODS: WE STUDIED THE GENOME-WIDE DNA METHYLATION PATTERN ASSOCIATED WITH RAPID LOSS OF KIDNEY FUNCTION USING THE INFINIUM HUMANMETHYLATION 450 K BEADCHIP IN 40 CHRONIC RENAL INSUFFICIENCY (CRIC) STUDY PARTICIPANTS (N = 3939) WITH THE HIGHEST AND LOWEST RATES OF DECLINE IN ESTIMATED GLOMERULAR FILTRATION RATE. RESULTS: THE MEAN EGFR SLOPE WAS 2.2 (1.4) AND -5.1 (1.2) ML/MIN/1.73 M(2) IN THE STABLE KIDNEY FUNCTION GROUP AND THE RAPID PROGRESSION GROUP, RESPECTIVELY. CPG ISLANDS IN NPHP4, IQSEC1 AND TCF3 WERE HYPERMETHYLATED TO A LARGER EXTENT IN SUBJECTS WITH STABLE KIDNEY FUNCTION (P-VALUES OF 7.8E-05 TO 9.5E-05). THESE GENES ARE INVOLVED IN PATHWAYS KNOWN TO PROMOTE THE EPITHELIAL TO MESENCHYMAL TRANSITION AND RENAL FIBROSIS. OTHER CKD-RELATED GENES THAT WERE DIFFERENTIALLY METHYLATED ARE NOS3, NFKBIL2, CLU, NFKBIB, TGFB3 AND TGFBI, WHICH ARE INVOLVED IN OXIDATIVE STRESS AND INFLAMMATORY PATHWAYS (P-VALUES OF 4.5E-03 TO 0.046). PATHWAY ANALYSIS USING INGENUITY PATHWAY ANALYSIS SHOWED THAT GENE NETWORKS RELATED TO CELL SIGNALING, CARBOHYDRATE METABOLISM AND HUMAN BEHAVIOR ARE EPIGENETICALLY REGULATED IN CKD. CONCLUSIONS: EPIGENETIC MODIFICATIONS MAY BE IMPORTANT IN DETERMINING THE RATE OF LOSS OF KIDNEY FUNCTION IN PATIENTS WITH ESTABLISHED CKD. 2014 2 6080 47 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 3 1271 41 CYTOSINE METHYLATION PREDICTS RENAL FUNCTION DECLINE IN AMERICAN INDIANS. DIABETIC NEPHROPATHY ACCOUNTS FOR MOST OF THE EXCESS MORTALITY IN INDIVIDUALS WITH DIABETES, BUT THE MOLECULAR MECHANISMS BY WHICH NEPHROPATHY DEVELOPS ARE LARGELY UNKNOWN. HERE WE TESTED CYTOSINE METHYLATION LEVELS AT 397,063 GENOMIC CPG SITES FOR ASSOCIATION WITH DECLINE IN THE ESTIMATED GLOMERULAR FILTRATION RATE (EGFR) OVER A SIX YEAR PERIOD IN 181 DIABETIC PIMA INDIANS. METHYLATION LEVELS AT 77 SITES SHOWED SIGNIFICANT ASSOCIATION WITH EGFR DECLINE AFTER CORRECTION FOR MULTIPLE COMPARISONS. A MODEL INCLUDING METHYLATION LEVEL AT TWO PROBES (CG25799291 AND CG22253401) IMPROVED PREDICTION OF EGFR DECLINE IN ADDITION TO BASELINE EGFR AND THE ALBUMIN TO CREATININE RATIO WITH THE PERCENT OF VARIANCE EXPLAINED SIGNIFICANTLY IMPROVING FROM 23.1% TO 42.2%. CG22253401 WAS ALSO SIGNIFICANTLY ASSOCIATED WITH EGFR DECLINE IN A CASE-CONTROL STUDY DERIVED FROM THE CHRONIC RENAL INSUFFICIENCY COHORT. PROBES AT WHICH METHYLATION SIGNIFICANTLY ASSOCIATED WITH EGFR DECLINE WERE LOCALIZED TO GENE REGULATORY REGIONS AND ENRICHED FOR GENES WITH METABOLIC FUNCTIONS AND APOPTOSIS. THREE OF THE 77 PROBES THAT WERE ASSOCIATED WITH EGFR DECLINE IN BLOOD SAMPLES SHOWED DIRECTIONALLY CONSISTENT AND SIGNIFICANT ASSOCIATION WITH FIBROSIS IN MICRODISSECTED HUMAN KIDNEY TISSUE, AFTER CORRECTION FOR MULTIPLE COMPARISONS. THUS, CYTOSINE METHYLATION LEVELS MAY PROVIDE BIOMARKERS OF DISEASE PROGRESSION IN DIABETIC NEPHROPATHY AND EPIGENETIC VARIATIONS CONTRIBUTE TO THE DEVELOPMENT OF DIABETIC KIDNEY DISEASE. 2018 4 2629 36 EPIGENOME-WIDE ASSOCIATION STUDY OF DIABETIC CHRONIC KIDNEY DISEASE PROGRESSION IN THE KOREAN POPULATION: THE KNOW-CKD STUDY. SINCE THE ETIOLOGY OF DIABETIC CHRONIC KIDNEY DISEASE (CKD) IS MULTIFACTORIAL, STUDIES ON DNA METHYLATION FOR KIDNEY FUNCTION DETERIORATION HAVE RARELY BEEN PERFORMED DESPITE THE NEED FOR AN EPIGENETIC APPROACH. THEREFORE, THIS STUDY AIMED TO IDENTIFY EPIGENETIC MARKERS ASSOCIATED WITH CKD PROGRESSION BASED ON THE DECLINE IN THE ESTIMATED GLOMERULAR FILTRATION RATE IN DIABETIC CKD IN KOREA. AN EPIGENOME-WIDE ASSOCIATION STUDY WAS PERFORMED USING WHOLE BLOOD SAMPLES FROM 180 CKD RECRUITED FROM THE KNOW-CKD COHORT. PYROSEQUENCING WAS ALSO PERFORMED ON 133 CKD PARTICIPANTS AS AN EXTERNAL REPLICATION ANALYSIS. FUNCTIONAL ANALYSES, INCLUDING THE ANALYSIS OF DISEASE-GENE NETWORKS, REACTOME PATHWAYS, AND PROTEIN-PROTEIN INTERACTION NETWORKS, WERE CONDUCTED TO IDENTIFY THE BIOLOGICAL MECHANISMS OF CPG SITES. A PHENOME-WIDE ASSOCIATION STUDY WAS PERFORMED TO DETERMINE THE ASSOCIATIONS BETWEEN CPG SITES AND OTHER PHENOTYPES. TWO EPIGENETIC MARKERS, CG10297223 ON AGTR1 AND CG02990553 ON KRT28 INDICATED A POTENTIAL ASSOCIATION WITH DIABETIC CKD PROGRESSION. BASED ON THE FUNCTIONAL ANALYSES, OTHER PHENOTYPES (BLOOD PRESSURE AND CARDIAC ARRHYTHMIA FOR AGTR1) AND BIOLOGICAL PATHWAYS (KERATINIZATION AND CORNIFIED ENVELOPE FOR KRT28) RELATED TO CKD WERE ALSO IDENTIFIED. THIS STUDY SUGGESTS A POTENTIAL ASSOCIATION BETWEEN THE CG10297223 AND CG02990553 AND THE PROGRESSION OF DIABETIC CKD IN KOREANS. NEVERTHELESS, FURTHER VALIDATION IS NEEDED THROUGH ADDITIONAL STUDIES. 2023 5 177 32 ACCELERATED EPIGENETIC AGING AND INFLAMMATORY/IMMUNOLOGICAL PROFILE (IPAGE) IN PATIENTS WITH CHRONIC KIDNEY DISEASE. CHRONIC KIDNEY DISEASE (CKD) IS DEFINED BY A REDUCED ESTIMATED GLOMERULAR FILTRATION RATE (EGFR). THIS FAILURE CAN BE RELATED TO A PHENOTYPE OF ACCELERATED AGING. IN THIS WORK, WE CONSIDERED 76 PATIENTS WITH END-STAGE RENAL DISEASE (ESRD) AND 83 HEALTHY CONTROLS. WE CONCOMITANTLY EVALUATED FOR THE FIRST TIME TWO MEASURES THAT CAN BE INFORMATIVE OF THE RATE OF AGING, I.E., WHOLE BLOOD DNA METHYLATION USING THE ILLUMINA INFINIUM EPIC ARRAY AND PLASMA LEVELS OF A SELECTION OF INFLAMMATORY/IMMUNOLOGICAL PROTEINS USING MULTIPLEX IMMUNOASSAYS. FIRST OF ALL, WE DEMONSTRATED ACCELERATED AGING IN TERMS OF THE MOST COMMON EPIGENETIC AGE ESTIMATORS IN CKD PATIENTS. MOREOVER, WE DEVELOPED A NEW CLOCK/PREDICTOR OF AGE BASED ON THE INFLAMMATORY/IMMUNOLOGICAL PROFILE (IPAGE) AND IDENTIFIED THE INFLAMMATORY/IMMUNOLOGICAL BIOMARKERS DIFFERENTIALLY EXPRESSED BETWEEN CASES AND CONTROLS. IPAGE APPEARED TO BE MORE SENSITIVE THAN EPIGENETIC CLOCKS IN QUANTIFYING THE ACCELERATED AGING PHENOTYPE OF ESRD PATIENTS. INTERESTINGLY, WE DID NOT FIND ANY CORRELATION BETWEEN THE AGE ACCELERATION EVALUATED ACCORDING TO THE EPIGENETIC CLOCKS AND IPAGE IN EITHER THE ESRD GROUP OR THE CONTROL GROUP. ON THE WHOLE, OUR DATA SHOW A CONSISTENT ACCELERATED AGING PHENOTYPE IN ESRD PATIENTS, WHICH IS BETTER APPRECIATED BY QUANTIFYING THE UNDERLYING INFLAMMATORY PROCESSES (INFLAMMAGING) BY IPAGE THAN BY USING EPIGENETIC CLOCKS. 2022 6 658 34 BLOOD DNA METHYLATION PREDICTS DIABETIC KIDNEY DISEASE PROGRESSION IN HIGH FAT DIET-FED MICE. DIABETIC KIDNEY DISEASE (DKD) PROGRESSES AT DIFFERENT RATES AMONG PATIENTS WITH TYPE 2 DIABETES MELLITUS (T2D). EARLY IDENTIFICATION OF PATIENTS WITH A HIGHER RISK OF DKD PROGRESSION IS ESSENTIAL TO IMPROVE PROGNOSIS. EPIGENETIC MODIFICATIONS, PARTICULARLY DNA METHYLATION, HAVE BEEN INDEPENDENTLY IMPLICATED IN T2D AND CHRONIC KIDNEY DISEASE. THE CURRENT STUDY AIMED TO DETERMINE CHANGES IN BLOOD DNA METHYLATION THAT REFLECTS AND PREDICTS DKD PROGRESSION. C57BL/6 MICE WERE FED A HIGH-FAT DIET (HFD) FROM WEANING AND SUBCLASSIFIED INTO TWO GROUPS, HFD-1 AND HFD-2, ACCORDING TO URINARY KIDNEY INJURY MARKER KIM-1/CREATININE RATIOS (LOW VS. HIGH) AND HISTOLOGICAL ABNORMALITIES (MILD-MODERATE VS. ADVANCED). DNA METHYLATION PROFILES WERE DETERMINED BY REDUCED REPRESENTATIVE BISULFIDE SEQUENCING (RRBS). OUR RESULTS CONFIRMED EARLY AND ESTABLISHED DKD AT WEEK 9 AND WEEK 32, RESPECTIVELY. AT WEEK 32, ADVANCED KIDNEY INJURY WAS ASSOCIATED WITH DYSREGULATION OF METHYLATION AND DEMETHYLATION ENZYMES IN THE KIDNEY. BLOOD RRBS REVEALED 579 AND 203 DIFFERENTIALLY METHYLATED SITES (DMS) BETWEEN HFD-1 AND HFD-2 ANIMALS AT WEEK 32 AND WEEK 9, RESPECTIVELY, AMONG WHICH 11 WERE COMMON. THE DMS IN BLOOD AND KIDNEY AT WEEK 32 WERE BOTH RELATED TO ORGAN DEVELOPMENT, NEUROGENESIS, CELL JUNCTION, AND WNT SIGNALLING, WHILE THE DMS IN BLOOD AT WEEK 9 SUGGESTED A SPECIFIC ENRICHMENT OF KIDNEY DEVELOPMENT PROCESSES. IN CONCLUSION, OUR DATA STRONGLY SUPPORT THE IMPLICATION OF EARLY BLOOD DNA METHYLATION MODIFICATIONS AND DKD PROGRESSION IN T2D THAT COULD BE USED TO IMPROVE THE DISEASE'S PROGNOSTICATION. 2022 7 4238 37 METHYLATION PATTERN OF URINARY DNA AS A MARKER OF KIDNEY FUNCTION DECLINE IN DIABETES. INTRODUCTION: RENAL TUBULAR INJURY CONTRIBUTES TO THE DECLINE IN KIDNEY FUNCTION IN PATIENTS WITH DIABETES. CELL TYPE-SPECIFIC DNA METHYLATION PATTERNS HAVE BEEN USED TO CALCULATE PROPORTIONS OF PARTICULAR CELL TYPES. IN THIS STUDY, WE DEVELOPED A METHOD TO DETECT RENAL TUBULAR INJURY IN PATIENTS WITH DIABETES BY DETECTING EXFOLIATED TUBULAR CELLS SHED INTO THE URINE BASED ON TUBULAR CELL-SPECIFIC DNA METHYLATION PATTERNS. RESEARCH DESIGN AND METHODS: WE IDENTIFIED DNA METHYLATION PATTERNS SPECIFIC FOR HUMAN RENAL PROXIMAL TUBULAR CELLS THROUGH COMPARTMENT-SPECIFIC METHYLOME ANALYSIS. WE NEXT DETERMINED THE METHYLATION LEVELS OF PROXIMAL TUBULE-SPECIFIC LOCI IN URINE SEDIMENT OF PATIENTS WITH DIABETES AND ANALYZED CORRELATION WITH CLINICAL VARIABLES. RESULTS: WE IDENTIFIED GENOMIC LOCI IN SMTNL2 AND G6PC TO BE SELECTIVELY UNMETHYLATED IN HUMAN PROXIMAL TUBULAR CELLS. THE METHYLATION LEVELS OF SMTNL2 AND G6PC IN URINE SEDIMENT, DEEMED TO REFLECT THE PROPORTION OF EXFOLIATED PROXIMAL TUBULAR CELLS DUE TO INJURY, CORRELATED WELL WITH EACH OTHER. METHYLATION LEVELS OF SMTNL2 IN URINE SEDIMENT SIGNIFICANTLY CORRELATED WITH THE ANNUAL DECLINE IN ESTIMATED GLOMERULAR FILTRATION RATE. MOREOVER, ADDITION OF URINARY SMTNL2 METHYLATION TO A MODEL CONTAINING KNOWN RISK FACTORS SIGNIFICANTLY IMPROVED DISCRIMINATION OF PATIENTS WITH DIABETES WITH FASTER ESTIMATED GLOMERULAR FILTRATION RATE DECLINE. CONCLUSIONS: THIS STUDY DEMONSTRATES THAT PATIENTS WITH DIABETES WITH CONTINUAL LOSS IN KIDNEY FUNCTION MAY BE STRATIFIED BY A SPECIFIC DNA METHYLATION SIGNATURE THROUGH EPIGENETIC URINALYSIS AND PROVIDES FURTHER EVIDENCE AT THE LEVEL OF EXFOLIATED CELLS IN THE URINE THAT INJURY OF PROXIMAL TUBULAR CELLS MAY CONTRIBUTE TO PATHOGENESIS OF DIABETIC KIDNEY DISEASE. 2020 8 6190 37 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 9 3568 33 IMPACT OF INFLAMMATION ON EPIGENETIC DNA METHYLATION - A NOVEL RISK FACTOR FOR CARDIOVASCULAR DISEASE? OBJECTIVE: THE LIFESPAN OF DIALYSIS PATIENTS IS AS SHORT AS IN PATIENTS WITH METASTATIC CANCER DISEASE, MAINLY DUE TO CARDIOVASCULAR DISEASE (CVD). DNA METHYLATION IS AN IMPORTANT CELLULAR MECHANISM MODULATING GENE EXPRESSION ASSOCIATED WITH AGEING, INFLAMMATION AND ATHEROSCLEROTIC PROCESSES. DESIGN: DNA METHYLATION WAS ANALYSED IN PERIPHERAL BLOOD LEUCOCYTES FROM THREE DIFFERENT GROUPS OF CHRONIC KIDNEY DISEASE (CKD) POPULATIONS (37 CKD STAGES 3 AND 4 PATIENTS, 98 CKD STAGE 5 PATIENTS AND 20 PREVALENT HAEMODIALYSIS PATIENTS). THIRTY-SIX HEALTHY SUBJECTS SERVED AS CONTROLS. CLINICAL CHARACTERISTICS (DIABETES MELLITUS, NUTRITIONAL STATUS AND PRESENCE OF CLINICAL CVD), INFLAMMATION AND OXIDATIVE STRESS BIOMARKERS, HOMOCYSTEINE AND GLOBAL DNA METHYLATION IN PERIPHERAL BLOOD LEUCOCYTES (DEFINED AS HPAII/MSPI RATIO BY THE LUMINOMETRIC METHYLATION ASSAY METHOD) WERE EVALUATED. CKD STAGE 5 PATIENTS (N=98) STARTING DIALYSIS TREATMENT WERE FOLLOWED FOR A PERIOD OF 36 +/- 2 MONTHS. RESULTS: INFLAMED PATIENTS HAD LOWER RATIOS OF HPAII/MSPI, INDICATING GLOBAL DNA HYPERMETHYLATION. ANALYSIS BY THE COX REGRESSION MODEL DEMONSTRATED THAT DNA HYPERMETHYLATION (HPAII/MSPI RATIO 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 13 3073 47 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 14 1990 28 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 15 3050 25 GENOME-WIDE ASSOCIATION ANALYSES FOR LUNG FUNCTION AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE IDENTIFY NEW LOCI AND POTENTIAL DRUGGABLE TARGETS. CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS CHARACTERIZED BY REDUCED LUNG FUNCTION AND IS THE THIRD LEADING CAUSE OF DEATH GLOBALLY. THROUGH GENOME-WIDE ASSOCIATION DISCOVERY IN 48,943 INDIVIDUALS, SELECTED FROM EXTREMES OF THE LUNG FUNCTION DISTRIBUTION IN UK BIOBANK, AND FOLLOW-UP IN 95,375 INDIVIDUALS, WE INCREASED THE YIELD OF INDEPENDENT SIGNALS FOR LUNG FUNCTION FROM 54 TO 97. A GENETIC RISK SCORE WAS ASSOCIATED WITH COPD SUSCEPTIBILITY (ODDS RATIO PER 1 S.D. OF THE RISK SCORE ( APPROXIMATELY 6 ALLELES) (95% CONFIDENCE INTERVAL) = 1.24 (1.20-1.27), P = 5.05 X 10(-49)), AND WE OBSERVED A 3.7-FOLD DIFFERENCE IN COPD RISK BETWEEN INDIVIDUALS IN THE HIGHEST AND LOWEST GENETIC RISK SCORE DECILES IN UK BIOBANK. THE 97 SIGNALS SHOW ENRICHMENT IN GENES FOR DEVELOPMENT, ELASTIC FIBERS AND EPIGENETIC REGULATION PATHWAYS. WE HIGHLIGHT TARGETS FOR DRUGS AND COMPOUNDS IN DEVELOPMENT FOR COPD AND ASTHMA (GENES IN THE INOSITOL PHOSPHATE METABOLISM PATHWAY AND CHRM3) AND DESCRIBE TARGETS FOR POTENTIAL DRUG REPOSITIONING FROM OTHER CLINICAL INDICATIONS. 2017 16 546 36 ATTENUATED EXPRESSION OF SLCO2A1 CAUSED BY DNA METHYLATION IN PEDIATRIC INFLAMMATORY BOWEL DISEASE. BACKGROUND: SLCO2A1 ENCODES A PROSTAGLANDIN (PG) TRANSPORTER, AND AUTOSOMAL RECESSIVE PATHOGENIC VARIANTS OF THIS GENE CAUSE CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1. IT IS UNCLEAR WHETHER A HETEROZYGOUS PATHOGENIC VARIANT OF SLCO2A1 HAS A ROLE IN THE PATHOGENESIS OF OTHER TYPES OF INFLAMMATORY BOWEL DISEASE (IBD). IN THIS STUDY, WE INVESTIGATED THE POSSIBLE INVOLVEMENT OF A LOCAL EPIGENETIC ALTERATION IN SLCO2A1 IN PATIENTS WITH A HETEROZYGOUS PATHOGENIC VARIANT. METHODS: WE CONDUCTED WHOLE-EXOME SEQUENCING OF SAMPLES FROM 2 SISTERS WITH SUSPECTED MONOGENIC IBD. IN ADDITION, WE PERFORMED BISULFITE SEQUENCING USING DNA EXTRACTED FROM THEIR SMALL AND LARGE INTESTINE SAMPLES TO EXPLORE EPIGENETIC ALTERATIONS. RESULTS: A HETEROZYGOUS SPLICING SITE VARIANT, SLCO2A1:C.940 + 1G > A, WAS DETECTED IN BOTH PATIENTS. TO EXPLORE THE POSSIBLE INVOLVEMENT OF EPIGENETIC ALTERATIONS, WE ANALYZED PROTEIN AND MESSENGER RNA EXPRESSION OF SLCO2A1, AND OBSERVED ATTENUATED SLCO2A1 EXPRESSION IN THE INFLAMED LESIONS OF THESE PATIENTS COMPARED WITH THAT IN THE CONTROL INDIVIDUALS. FURTHERMORE, BISULFITE SEQUENCING INDICATED DENSE METHYLATION IN THE PROMOTER REGION OF SLCO2A1 ONLY IN THE INFLAMED LESIONS OF BOTH PATIENTS. THE URINARY PG METABOLITE LEVELS IN THESE PATIENTS WERE COMPARABLE TO THOSE IN PATIENTS WITH CHRONIC ENTEROPATHY ASSOCIATED WITH SLCO2A1 AND HIGHER THAN THOSE IN THE CONTROL INDIVIDUALS. WE FOUND CONSIDERABLY HIGHER LEVELS OF THE METABOLITES IN PATIENT 1, WHO SHOWED MORE SEVERE SYMPTOMS THAN PATIENT 2. CONCLUSIONS: LOCAL DNA METHYLATION ATTENUATED SLCO2A1 EXPRESSION, WHICH MAY EVOKE LOCAL INFLAMMATION OF THE MUCOSA BY THE UNINCORPORATED PG. THESE FINDINGS MAY IMPROVE OUR UNDERSTANDING OF THE EPIGENETIC MECHANISMS UNDERLYING IBD DEVELOPMENT. 2023 17 3125 24 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 18 1607 32 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 19 2921 36 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 20 5092 33 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