1 3989 138 LONGITUDINAL ANALYSIS OF BLOOD DNA METHYLATION IDENTIFIES MECHANISMS OF RESPONSE TO TUMOR NECROSIS FACTOR INHIBITOR THERAPY IN RHEUMATOID ARTHRITIS. BACKGROUND: RHEUMATOID ARTHRITIS (RA) IS A CHRONIC, IMMUNE-MEDIATED INFLAMMATORY DISEASE OF THE JOINTS THAT HAS BEEN ASSOCIATED WITH VARIATION IN THE PERIPHERAL BLOOD METHYLOME. IN THIS STUDY, WE AIM TO IDENTIFY EPIGENETIC VARIATION THAT IS ASSOCIATED WITH THE RESPONSE TO TUMOR NECROSIS FACTOR INHIBITOR (TNFI) THERAPY. METHODS: PERIPHERAL BLOOD GENOME-WIDE DNA METHYLATION PROFILES WERE ANALYZED IN A DISCOVERY COHORT OF 62 RA PATIENTS AT BASELINE AND AT WEEK 12 OF TNFI THERAPY. DNA METHYLATION OF INDIVIDUAL CPG SITES AND ENRICHMENT OF BIOLOGICAL PATHWAYS WERE EVALUATED FOR THEIR ASSOCIATION WITH DRUG RESPONSE. USING A NOVEL CELL DECONVOLUTION APPROACH, ALTERED DNA METHYLATION ASSOCIATED WITH TNFI RESPONSE WAS ALSO TESTED IN THE SIX MAIN IMMUNE CELL TYPES IN BLOOD. VALIDATION OF THE RESULTS WAS PERFORMED IN AN INDEPENDENT LONGITUDINAL COHORT OF 60 RA PATIENTS. FINDINGS: TREATMENT WITH TNFI WAS ASSOCIATED WITH SIGNIFICANT LONGITUDINAL PERIPHERAL BLOOD METHYLATION CHANGES IN BIOLOGICAL PATHWAYS RELATED TO RA (FDR<0.05). 139 BIOLOGICAL FUNCTIONS WERE MODIFIED BY THERAPY, WITH METHYLATION LEVELS CHANGING SYSTEMATICALLY TOWARDS A SIGNATURE SIMILAR TO THAT OF HEALTHY CONTROLS. DIFFERENCES IN THE METHYLATION PROFILE OF T CELL ACTIVATION AND DIFFERENTIATION, GTPASE-MEDIATED SIGNALING, AND ACTIN FILAMENT ORGANIZATION PATHWAYS WERE ASSOCIATED WITH THE CLINICAL RESPONSE TO THERAPY. CELL TYPE DECONVOLUTION ANALYSIS IDENTIFIED CPG SITES IN CD4+T, NK, NEUTROPHILS AND MONOCYTES THAT WERE SIGNIFICANTLY ASSOCIATED WITH THE RESPONSE TO TNFI. INTERPRETATION: OUR RESULTS SHOW THAT TREATMENT WITH TNFI RESTORES HOMEOSTATIC BLOOD METHYLATION IN RA. THE CLINICAL RESPONSE TO TNFI IS ASSOCIATED TO METHYLATION VARIATION IN SPECIFIC BIOLOGICAL PATHWAYS, AND IT INVOLVES CELLS FROM BOTH THE INNATE AND ADAPTIVE IMMUNE SYSTEMS. FUNDING: THE INSTITUTO DE SALUD CARLOS III. 2022 2 2920 46 GENE-SET ANALYSIS IS SEVERELY BIASED WHEN APPLIED TO GENOME-WIDE METHYLATION DATA. MOTIVATION: DNA METHYLATION IS AN EPIGENETIC MARK THAT CAN STABLY REPRESS GENE EXPRESSION. BECAUSE OF ITS BIOLOGICAL AND CLINICAL SIGNIFICANCE, SEVERAL METHODS HAVE BEEN DEVELOPED TO COMPARE GENOME-WIDE PATTERNS OF METHYLATION BETWEEN GROUPS OF SAMPLES. THE APPLICATION OF GENE SET ANALYSIS TO IDENTIFY RELEVANT GROUPS OF GENES THAT ARE ENRICHED FOR DIFFERENTIALLY METHYLATED GENES IS OFTEN A MAJOR COMPONENT OF THE ANALYSIS OF THESE DATA. THIS CAN BE USED, FOR EXAMPLE, TO IDENTIFY PROCESSES OR PATHWAYS THAT ARE PERTURBED IN DISEASE DEVELOPMENT. WE SHOW THAT GENE-SET ANALYSIS, AS IT IS TYPICALLY APPLIED TO GENOME-WIDE METHYLATION ASSAYS, IS SEVERELY BIASED AS A RESULT OF DIFFERENCES IN THE NUMBERS OF CPG SITES ASSOCIATED WITH DIFFERENT CLASSES OF GENES AND GENE PROMOTERS. RESULTS: WE DEMONSTRATE THIS BIAS USING PUBLISHED DATA FROM A STUDY OF DIFFERENTIAL CPG ISLAND METHYLATION IN LUNG CANCER AND A DATASET WE GENERATED TO STUDY METHYLATION CHANGES IN PATIENTS WITH LONG-STANDING ULCERATIVE COLITIS. WE SHOW THAT SEVERAL OF THE GENE SETS THAT SEEM ENRICHED WOULD ALSO BE IDENTIFIED WITH RANDOMIZED DATA. WE SUGGEST TWO EXISTING APPROACHES THAT CAN BE ADAPTED TO CORRECT THE BIAS. ACCOUNTING FOR THE BIAS IN THE LUNG CANCER AND ULCERATIVE COLITIS DATASETS PROVIDES NOVEL BIOLOGICAL INSIGHTS INTO THE ROLE OF METHYLATION IN CANCER DEVELOPMENT AND CHRONIC INFLAMMATION, RESPECTIVELY. OUR RESULTS HAVE SIGNIFICANT IMPLICATIONS FOR MANY PREVIOUS GENOME-WIDE METHYLATION STUDIES THAT HAVE DRAWN CONCLUSIONS ON THE BASIS OF SUCH STRONGLY BIASED ANALYSIS. CONTACT: CATHAL.SEOIGHE@NUIGALWAY.IE SUPPLEMENTARY INFORMATION: SUPPLEMENTARY DATA ARE AVAILABLE AT BIOINFORMATICS ONLINE. 2013 3 6311 39 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 4 1307 48 DEFINING A METHYLATION SIGNATURE ASSOCIATED WITH OPERATIONAL TOLERANCE IN KIDNEY TRANSPLANT RECIPIENTS. OPERATIONAL TOLERANCE AFTER KIDNEY TRANSPLANTATION IS DEFINED AS STABLE GRAFT ACCEPTANCE WITHOUT THE NEED FOR IMMUNOSUPPRESSION THERAPY. HOWEVER, IT IS NOT CLEAR WHICH CELLULAR AND MOLECULAR PATHWAYS ARE DRIVING TOLERANCE IN THESE PATIENTS. WE PERFORMED GENOME-WIDE ANALYSIS OF DNA METHYLATION IN PERIPHERAL BLOOD MONONUCLEAR CELLS FROM KIDNEY TRANSPLANT RECIPIENTS WITH CHRONIC REJECTION AND OPERATIONAL TOLERANCE FROM THE GENETIC ANALYSIS OF MOLECULAR BIOMARKERS OF IMMUNOLOGICAL TOLERANCE (GAMBIT) STUDY. OUR RESULTS SHOWED THAT BOTH CLINICAL STAGES DIVERGE IN 2737 GENES, INDICATING THAT EACH ONE HAS A SPECIFIC METHYLATION SIGNATURE ASSOCIATED WITH TRANSPLANT OUTCOME. WE ALSO OBSERVED THAT TOLERANCE IS ASSOCIATED WITH DEMETHYLATION IN GENES INVOLVED IN IMMUNE FUNCTION, INCLUDING B AND T CELL ACTIVATION AND TH17 DIFFERENTIATION, WHILE IN CHRONIC REJECTION IT IS ASSOCIATED WITH INTRACELLULAR SIGNALING AND UBIQUITINATION PATHWAYS. USING CO-EXPRESSION NETWORK ANALYSIS, WE SELECTED 12 GENOMIC REGIONS THAT ARE SPECIFICALLY HYPOMETHYLATED OR HYPERMETHYLATED IN TOLERANT PATIENTS. ANALYSIS OF THESE GENES IN TRANSPLANTED PATIENTS WITH LOW DOSE OF STEROIDS SHOWED THAT THESE HAVE A SIMILAR METHYLATION SIGNATURE TO THAT OF TOLERANT RECIPIENTS. OVERALL, THESE RESULTS DEMONSTRATE THAT METHYLATION ANALYSIS CAN MIRROR THE IMMUNE STATUS ASSOCIATED WITH TRANSPLANT OUTCOME AND PROVIDES A STARTING POINT FOR UNDERSTANDING THE EPIGENETIC MECHANISMS ASSOCIATED WITH TOLERANCE. 2021 5 70 36 A METHOD TO DETECT DIFFERENTIALLY METHYLATED LOCI WITH NEXT-GENERATION SEQUENCING. EPIGENETIC CHANGES, ESPECIALLY DNA METHYLATION AT CPG LOCI HAVE IMPORTANT IMPLICATIONS IN CANCER AND OTHER COMPLEX DISEASES. WITH THE DEVELOPMENT OF NEXT-GENERATION SEQUENCING (NGS), IT IS FEASIBLE TO GENERATE DATA TO INTERROGATE THE DIFFERENCE IN METHYLATION STATUS FOR GENOME-WIDE LOCI USING CASE-CONTROL DESIGN. HOWEVER, A PROPER AND EFFICIENT STATISTICAL TEST IS LACKING. THERE ARE SEVERAL CHALLENGES. FIRST, UNLIKE METHYLATION EXPERIMENTS USING MICROARRAYS, WHERE THERE IS ONE MEASURE OF METHYLATION FOR ONE INDIVIDUAL AT A PARTICULAR CPG SITE, HERE WE HAVE THE COUNTS OF METHYLATION ALLELE AND UNMETHYLATION ALLELE FOR EACH INDIVIDUAL. SECOND, DUE TO THE NATURE OF SAMPLE PREPARATION, THE MEASURED METHYLATION REFLECTS THE METHYLATION STATUS OF A MIXTURE OF CELLS INVOLVED IN SAMPLE PREPARATION. THEREFORE, THE UNDERLYING DISTRIBUTION OF THE MEASURED METHYLATION LEVEL IS UNKNOWN, AND A ROBUST TEST IS MORE DESIRABLE THAN PARAMETRIC APPROACH. THIRD, CURRENTLY NGS MEASURES METHYLATION AT OVER 2 MILLION CPG SITES. ANY STATISTICAL TESTS HAVE TO BE COMPUTATIONALLY EFFICIENT IN ORDER TO BE APPLIED TO THE NGS DATA. TAKING THESE CHALLENGES INTO ACCOUNT, WE PROPOSE A TEST FOR DIFFERENTIAL METHYLATION BASED ON CLUSTERED DATA ANALYSIS BY MODELING THE METHYLATION COUNTS. WE PERFORMED SIMULATIONS TO SHOW THAT IT IS ROBUST UNDER SEVERAL DISTRIBUTIONS FOR THE MEASURED METHYLATION LEVELS. IT HAS GOOD POWER AND IS COMPUTATIONALLY EFFICIENT. FINALLY, WE APPLY THE TEST TO OUR NGS DATA ON CHRONIC LYMPHOCYTIC LEUKEMIA. THE RESULTS INDICATE THAT IT IS A PROMISING AND PRACTICAL TEST. 2013 6 2400 50 EPIGENETIC REPROGRAMMING OF IMMUNE CELLS IN WOMEN WITH PCOS IMPACT GENES CONTROLLING REPRODUCTIVE FUNCTION. CONTEXT: POLYCYSTIC OVARY SYNDROME (PCOS) IS A CHRONIC DISEASE AFFECTING REPRODUCTIVE FUNCTION AND WHOLE-BODY METABOLISM. ALTHOUGH THE ETIOLOGY IS UNCLEAR, EMERGING EVIDENCE INDICATES THAT THE EPIGENETICS MAY BE A CONTRIBUTING FACTOR. OBJECTIVE: TO DETERMINE THE ROLE OF GLOBAL AND GENOME-WIDE EPIGENETIC MODIFICATIONS IN SPECIFIC IMMUNE CELLS IN PCOS COMPARED WITH CONTROLS AND WHETHER THESE COULD BE RELATED TO CLINICAL FEATURES OF PCOS. DESIGN: CROSS-SECTIONAL STUDY. PARTICIPANTS: WOMEN WITH (N = 17) OR WITHOUT PCOS (N = 17). SETTING: RECRUITED FROM THE GENERAL COMMUNITY. MAIN OUTCOME MEASURES: ISOLATED PERIPHERAL BLOOD MONONUCLEAR CELLS WERE ANALYZED USING MULTICOLOR FLOW CYTOMETRY METHODS TO DETERMINE GLOBAL DNA METHYLATION LEVELS IN A CELL-SPECIFIC FASHION. TRANSCRIPTOMIC AND GENOME-WIDE DNA METHYLATION ANALYSES WERE PERFORMED ON T HELPER CELLS USING RNA SEQUENCING AND REDUCED REPRESENTATION BISULFITE SEQUENCING. RESULTS: WOMEN WITH PCOS HAD LOWER GLOBAL DNA METHYLATION IN MONOCYTES (P = 0.006) AND IN T HELPER (P = 0.004), T CYTOTOXIC (P = 0.004), AND B CELLS (P = 0.03). SPECIFIC GENOME-WIDE DNA METHYLATION ANALYSIS OF T HELPER CELLS FROM WOMEN WITH PCOS IDENTIFIED 5581 DIFFERENTIALLY METHYLATED CPG SITES. FUNCTIONAL GENE ONTOLOGY ENRICHMENT ANALYSIS SHOWED THAT GENES LOCATED AT THE PROXIMITY OF DIFFERENTIALLY METHYLATED CPG SITES BELONG TO PATHWAYS RELATED TO REPRODUCTIVE FUNCTION AND IMMUNE CELL FUNCTION. HOWEVER, THESE GENES WERE NOT ALTERED AT THE TRANSCRIPTOMIC LEVEL. CONCLUSIONS: IT WAS SHOWN THAT PCOS IS ASSOCIATED WITH GLOBAL AND GENE-SPECIFIC DNA METHYLATION REMODELING IN A CELL TYPE-SPECIFIC MANNER. FURTHER INVESTIGATION IS WARRANTED TO DETERMINE WHETHER EPIGENETIC REPROGRAMMING OF IMMUNE CELLS IS IMPORTANT IN DETERMINING THE DIFFERENT PHENOTYPES OF PCOS. 2019 7 1500 42 DNA METHYLATION ANALYSIS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS. PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE THAT IS CHARACTERIZED BY ABERRANT CROSS-TALK BETWEEN KERATINOCYTES AND IMMUNE CELLS SUCH AS CD4+ T CELLS, RESULTING IN KERATINOCYTE HYPERPROLIFERATION IN THE EPIDERMIS. DNA METHYLATION, ONE OF SEVERAL EPIGENETIC MECHANISMS, PLAYS AN IMPORTANT ROLE IN GENE EXPRESSION WITHOUT CHANGING THE DNA SEQUENCE. SEVERAL STUDIES HAVE SUGGESTED THE INVOLVEMENT OF EPIGENETIC REGULATION IN SKIN LESIONS FROM PATIENTS WITH PSORIASIS. IN THIS STUDY, WE INVESTIGATED THE GENOME-WIDE DNA METHYLATION STATUS OF CD4+ T CELLS IN PATIENTS WITH PSORIASIS COMPARED WITH HEALTHY SUBJECTS USING METHYLATED DNA IMMUNOPRECIPITATION SEQUENCING (MEDIP-SEQ). THE RESULTS OF MEDIP-SEQ SHOWED THAT THE GLOBAL METHYLATION VALUES OF CD4+ T CELLS ARE HIGHER IN PATIENTS WITH PSORIASIS THAN IN HEALTHY CONTROLS, PARTICULARLY IN THE PROMOTER REGIONS. AMONG THE MOST HYPERMETHYLATED GENES IN THE PROMOTER REGIONS, WE SELECTED THE GENES WHOSE EXPRESSION IS SIGNIFICANTLY REDUCED IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. STUDIES USING THE METHYLATION INHIBITOR 5-AZACYTIDINE IN VITRO METHYLATION ASSAYS HAVE SHOWN THAT THE DIFFERENTIAL EXPRESSION LEVELS WERE ASSOCIATED WITH THE METHYLATION STATUS OF EACH GENE. BISULFITE SEQUENCING OF THE TRANSCRIPTION START REGION OF PHOSPHATIDIC ACID PHOSPHATASE TYPE 2 DOMAIN CONTAINING 3 (PPAPDC3), ONE OF THE SELECTED GENES, SHOWED HYPERMETHYLATION IN THE CD4+ T CELLS OF PSORIASIS PATIENTS. THESE RESULTS SUGGESTED THAT THE METHYLATION STATUS, WHICH IS IDENTIFIED BY MEDIP-SEQ OF THE GENES, WAS CORRELATED WITH THE MRNA EXPRESSION LEVEL OF THE GENES. COLLECTIVELY, THE DNA METHYLATION STATUS IN CD4+ T CELLS MIGHT BE ASSOCIATED WITH THE PATHOGENESIS OF PSORIASIS. 2014 8 287 35 AGING AND CHRONIC SUN EXPOSURE CAUSE DISTINCT EPIGENETIC CHANGES IN HUMAN SKIN. EPIGENETIC CHANGES ARE WIDELY CONSIDERED TO PLAY AN IMPORTANT ROLE IN AGING, BUT EXPERIMENTAL EVIDENCE TO SUPPORT THIS HYPOTHESIS HAS BEEN SCARCE. WE HAVE USED ARRAY-BASED ANALYSIS TO DETERMINE GENOME-SCALE DNA METHYLATION PATTERNS FROM HUMAN SKIN SAMPLES AND TO INVESTIGATE THE EFFECTS OF AGING, CHRONIC SUN EXPOSURE, AND TISSUE VARIATION. OUR RESULTS REVEAL A HIGH DEGREE OF TISSUE SPECIFICITY IN THE METHYLATION PATTERNS AND ALSO SHOWED VERY LITTLE INTERINDIVIDUAL VARIATION WITHIN TISSUES. DATA STRATIFICATION BY AGE REVEALED THAT DNA FROM OLDER INDIVIDUALS WAS CHARACTERIZED BY A SPECIFIC HYPERMETHYLATION PATTERN AFFECTING LESS THAN 1% OF THE MARKERS ANALYZED. INTERESTINGLY, STRATIFICATION BY SUN EXPOSURE PRODUCED A FUNDAMENTALLY DIFFERENT PATTERN WITH A SIGNIFICANT TREND TOWARDS HYPOMETHYLATION. OUR RESULTS THUS IDENTIFY DEFINED AGE-RELATED DNA METHYLATION CHANGES AND SUGGEST THAT THESE ALTERATIONS MIGHT CONTRIBUTE TO THE PHENOTYPIC CHANGES ASSOCIATED WITH SKIN AGING. 2010 9 5393 48 REDUCED CHROMATIN ACCESSIBILITY TO CD4 T CELL SUPER-ENHANCERS ENCOMPASSING SUSCEPTIBILITY LOCI OF RHEUMATOID ARTHRITIS. BACKGROUND: RHEUMATOID ARTHRITIS (RA) IS AN INFLAMMATORY DISEASE THAT MANIFESTS AS A PRECLINICAL STAGE OF SYSTEMIC AUTOIMMUNITY FOLLOWED BY CHRONIC PROGRESSIVE SYNOVITIS. DISEASE-ASSOCIATED GENETIC SNP VARIANTS PREDOMINANTLY MAP TO NON-CODING, REGULATORY REGIONS OF FUNCTIONAL IMPORTANCE IN CD4 T CELLS, IMPLICATING THESE CELLS AS KEY REGULATORS. A BETTER UNDERSTANDING OF THE EPIGENOME OF CD4 T CELLS HOLDS THE PROMISE OF PROVIDING INFORMATION ON THE INTERACTION BETWEEN GENETIC SUSCEPTIBILITY AND EXOGENOUS FACTORS. METHODS: WE MAPPED REGIONS OF CHROMATIN ACCESSIBILITY USING ATAC-SEQ IN PERIPHERAL CD4 T CELL SUBSETS OF PATIENTS WITH RA (N=18) AND COMPARED THEM TO T CELLS FROM PATIENTS WITH PSORIATIC ARTHRITIS (N=11) AND AGE-MATCHED HEALTHY CONTROLS (N=10). TRANSCRIPTS OF SELECTED GENES WERE QUANTIFIED USING QPCR. FINDINGS: RA-ASSOCIATED EPIGENETIC SIGNATURES WERE IDENTIFIED THAT IN PART OVERLAPPED BETWEEN CENTRAL AND EFFECTOR MEMORY CD4 T CELLS AND THAT WERE TO A LESSER EXTENT ALREADY PRESENT IN NAIVE CELLS. SITES MORE ACCESSIBLE IN RA WERE HIGHLY ENRICHED FOR THE MOTIF OF THE TRANSCRIPTION FACTOR (TF) CTCF SUGGESTING DIFFERENCES IN THE THREE-DIMENSIONAL CHROMATIN STRUCTURE. UNEXPECTEDLY, SITES WITH REDUCED CHROMATIN ACCESSIBILITY WERE ENRICHED FOR MOTIFS OF TFS PERTINENT FOR T CELL FUNCTION. MOST STRIKINGLY, SUPER-ENHANCERS ENCOMPASSING RA-ASSOCIATED SNPS WERE LESS ACCESSIBLE. ANALYSIS OF SELECTED TRANSCRIPTS AND PUBLISHED DNA METHYLATION PATTERNS WERE CONSISTENT WITH THIS FINDING. THE PREFERENTIAL LOSS IN ACCESSIBILITY AT THESE SUPER-ENHANCERS WAS SEEN IN PATIENTS WITH HIGH AND LOW DISEASE ACTIVITY AND ON A VARIETY OF IMMUNOSUPPRESSIVE TREATMENT MODALITIES. INTERPRETATION: DISEASE-ASSOCIATED GENES ARE EPIGENETICALLY LESS POISED TO RESPOND IN CD4 T CELLS FROM PATIENTS WITH ESTABLISHED RA. FUNDING: THIS WORK WAS SUPPORTED BY I01 BX001669 FROM THE VETERANS ADMINISTRATION. 2022 10 3503 32 IDENTIFICATION OF POTENTIAL DIFFERENTIALLY METHYLATED GENE-RELATED BIOMARKERS IN ENDOMETRIOSIS. AIM: TO IDENTIFY EPIGENETIC ALTERATIONS OF DIFFERENTIALLY EXPRESSED GENES AND SCREEN OUT TARGETED THERAPEUTIC DRUGS IN ENDOMETRIOSIS. METHODS: BASED ON THE GENE EXPRESSION OMNIBUS DATABASE AND A SERIES OF BIOLOGICAL INFORMATION ANALYSIS TOOLS, SUPPLEMENTED BY VALIDATION OF CLINICAL SAMPLES, ABERRANT DNA METHYLATION-DRIVEN GENES AND THEIR FUNCTIONS WERE EXPLORED, AS WELL AS POSSIBLE TARGETED DRUGS. RESULTS: THIS STUDY SCREENED OUT A RANGE OF DNA METHYLATION-DRIVEN GENES THAT WERE ASSOCIATED WITH POWERFUL PROPERTIES AND CORRESPONDING PATHWAYS. AMONG THEM, BDNF AND CCL2 WERE KEY GENES IN THE DEVELOPMENT OF ENDOMETRIOSIS. FOUR CHEMICAL AGENTS HAVE BEEN FLAGGED AS POTENTIAL TREATMENTS FOR ENDOMETRIOSIS. CONCLUSION: THESE CANDIDATE GENES AND SMALL-MOLECULE AGENTS MAY BE FURTHER EXPLORED AS POTENTIAL TARGETS AND DRUGS FOR ENDOMETRIOSIS DIAGNOSIS AND THERAPY, RESPECTIVELY. 2022 11 822 35 CHARACTERIZATION OF BLOOD SURROGATE IMMUNE-METHYLATION BIOMARKERS FOR IMMUNE CELL INFILTRATION IN CHRONIC INFLAMMAGING DISORDERS. ALZHEIMER'S DISEASE (AD) AND ATHEROSCLEROSIS ARE BOTH CHRONIC AGE- AND INFLAMMATION-DEPENDENT DISEASES. IN ADDITION, ATHEROSCLEROSIS IS FREQUENTLY OBSERVED IN AD PATIENTS INDICATING COMMON INVOLVEMENT OF VASCULAR COMPONENTS IN BOTH DISEASE ETIOLOGIES. RECENTLY, EPIGENOME-WIDE ASSOCIATION STUDIES HAVE IDENTIFIED EPIGENETIC ALTERATIONS, AND IN PARTICULARLY DNA METHYLATION CHANGES FOR BOTH DISORDERS. WE HYPOTHESIZED THE EXISTENCE OF A COMMON DNA METHYLATION PROFILE IN ATHEROSCLEROSIS AND AD WHICH MAY BE VALUABLE AS A BLOOD-BASED DNA METHYLATION INFLAMMAGING BIOMARKER. USING PUBLICLY AVAILABLE 450K ILLUMINA METHYLATION DATASETS, WE IDENTIFIED A CO-METHYLATION NETWORK ASSOCIATED WITH BOTH ATHEROSCLEROSIS AND AD IN WHOLE BLOOD SAMPLES. THIS METHYLATION PROFILE APPEARED TO INDICATE SHIFTS IN BLOOD IMMUNE CELL TYPE DISTRIBUTION. REMARKABLY, SIMILAR METHYLATION CHANGES WERE ALSO DETECTED IN DISEASE TISSUES, INCLUDING AD BRAIN TISSUES, ATHEROSCLEROTIC PLAQUES, AND TUMORS AND WERE FOUND TO CORRELATE WITH IMMUNE CELL INFILTRATION. IN ADDITION, THIS IMMUNE-RELATED METHYLATION PROFILE COULD ALSO BE DETECTED IN OTHER INFLAMMAGING DISEASES, INCLUDING PARKINSON'S DISEASE AND OBESITY, BUT NOT IN MULTIPLE SCLEROSIS, SCHIZOPHRENIA, AND OSTEOPOROSIS. IN CONCLUSION, WE IDENTIFIED A BLOOD-BASED IMMUNE-RELATED DNA METHYLATION SIGNATURE IN MULTIPLE INFLAMMAGING DISEASES ASSOCIATED WITH CHANGES IN BLOOD IMMUNE CELL COUNTS AND PREDICTIVE FOR IMMUNE CELL INFILTRATION IN DISEASED TISSUES. IN ADDITION TO EPIGENETIC CLOCK MEASUREMENTS, THIS IMMUNE-METHYLATION SIGNATURE MAY BECOME A VALUABLE BLOOD-BASED BIOMARKER TO PREVENT CHRONIC INFLAMMATORY DISEASE DEVELOPMENT OR MONITOR LIFESTYLE INTERVENTION STRATEGIES WHICH PROMOTE HEALTHY AGING. 2019 12 2797 31 FCER1G GENE HYPOMETHYLATION IN PATIENTS WITH RHEUMATOID ARTHRITIS. RHEUMATOID ARTHRITIS (RA) IS A CHRONIC AUTOIMMUNE DISEASE THAT, WHEN IMPROPERLY TREATED, LEADS TO DISABILITY IN PATIENTS. VARIOUS FACTORS THAT MAY CAUSE THE DEVELOPMENT AND ACTIVITY OF RA ARE BEING CONSIDERED. EPIGENETIC FACTORS ARE ALSO RECEIVING INCREASING ATTENTION. IN OUR STUDY, WE ANALYZED THE ASSOCIATION BETWEEN FCER1G GENE METHYLATION AND RA ACTIVITY. WE CONDUCTED OUR STUDY IN 50 RA PATIENTS AND 24 CONTROLS. THE PATIENTS WERE DIVIDED INTO TWO GROUPS IN TERMS OF HIGH DISEASE ACTIVITY AND REMISSION. QUANTITATIVE REAL-TIME METHYLATION-SPECIFIC PCR WAS USED TO ANALYZE THE METHYLATION STATUS OF THE INVESTIGATED GENES. WE OBSERVED THAT RA PATIENTS HAVE LOWER LEVELS OF METHYLATION OF THE FCER1G GENE COMPARED TO CONTROLS, BUT WE DID NOT FIND ANY DIFFERENCE IN THE METHYLATION STATUS OF THIS GENE BETWEEN PATIENTS WITH HIGH DISEASE ACTIVITY AND REMISSION. THE RESULTS OF THIS STUDY SUGGEST THAT FCER1G GENE METHYLATION MAY BE A NEW POTENTIAL EPIGENETIC MARKER OF RA THAT IS INDEPENDENT OF DISEASE ACTIVITY. 2022 13 3994 39 LONGITUDINAL PROFILING IN PATIENTS UNDERGOING CARDIAC SURGERY REVEALS POSTOPERATIVE CHANGES IN DNA METHYLATION. BACKGROUND: CARDIAC SURGERY AND CARDIOPULMONARY BYPASS INDUCE A SUBSTANTIAL IMMUNE AND INFLAMMATORY RESPONSE, THE OVERACTIVATION OF WHICH IS ASSOCIATED WITH SIGNIFICANT PULMONARY, CARDIOVASCULAR, AND NEUROLOGIC COMPLICATIONS. COMMENSURATE WITH THE IMMUNE AND INFLAMMATORY RESPONSE ARE CHANGES IN THE HEART AND VASCULATURE ITSELF, WHICH TOGETHER DRIVE POSTOPERATIVE COMPLICATIONS THROUGH MECHANISMS THAT ARE POORLY UNDERSTOOD. LONGITUDINAL DNA METHYLATION PROFILING HAS THE POTENTIAL TO IDENTIFY CHANGES IN GENE REGULATORY MECHANISMS THAT ARE SECONDARY TO SURGERY AND TO IDENTIFY MOLECULAR PROCESSES THAT PREDICT AND/OR CAUSE POSTOPERATIVE COMPLICATIONS. IN THIS STUDY, WE MEASURE DNA METHYLATION IN PREOPERATIVE AND POSTOPERATIVE WHOLE BLOOD SAMPLES FROM 96 PATIENTS UNDERGOING CARDIAC SURGERY ON CARDIOPULMONARY BYPASS. RESULTS: WHILE THE VAST MAJORITY OF DNA METHYLATION IS UNCHANGED BY SURGERY AFTER ACCOUNTING FOR CHANGES IN CELL-TYPE COMPOSITION, WE IDENTIFY SEVERAL LOCI WITH STATISTICALLY SIGNIFICANT POSTOPERATIVE CHANGES IN METHYLATION. ADDITIONALLY, TWO OF THESE LOCI ARE ASSOCIATED WITH NEW-ONSET POSTOPERATIVE ATRIAL FIBRILLATION, A SIGNIFICANT COMPLICATION AFTER CARDIAC SURGERY. PAIRED STATISTICAL ANALYSIS, USE OF FACS DATA TO SUPPORT SUFFICIENT CONTROL OF CELL-TYPE HETEROGENEITY, AND MEASUREMENT OF IL6 LEVELS IN A SUBSET OF PATIENTS ADD RIGOR TO THIS ANALYSIS, ALLOWING US TO DISTINGUISH CELL-TYPE VARIABILITY FROM ACTUAL CHANGES IN METHYLATION. CONCLUSIONS: THIS STUDY IDENTIFIES SIGNIFICANT CHANGES IN DNA METHYLATION THAT OCCUR IMMEDIATELY AFTER CARDIAC SURGERY AND DEMONSTRATES THAT THESE ACUTE ALTERATIONS IN DNA METHYLATION HAVE THE GRANULARITY TO IDENTIFY PROCESSES ASSOCIATED WITH MAJOR POSTOPERATIVE COMPLICATIONS. THIS RESEARCH ALSO ESTABLISHES METHODS FOR CONTROLLING FOR CELL-TYPE VARIABILITY IN A LARGE HUMAN COHORT THAT MAY BE USEFUL TO DEPLOY IN OTHER LONGITUDINAL STUDIES OF EPIGENETIC MARKS IN THE SETTING OF ACUTE AND CHRONIC DISEASE. 2022 14 1583 42 DNA METHYLATION PROFILES OF BLOOD CELLS ARE DISTINCT BETWEEN EARLY-ONSET OBESE AND CONTROL INDIVIDUALS. OBESITY IS A HIGHLY PREVALENT, CHRONIC DISORDER THAT HAS BEEN INCREASING IN INCIDENCE IN YOUNG PATIENTS. BOTH EPIGENETIC AND GENETIC ABERRATIONS MAY PLAY A ROLE IN THE PATHOGENESIS OF OBESITY. THEREFORE, IN-DEPTH EPIGENOMIC AND GENOMIC ANALYSES WILL ADVANCE OUR UNDERSTANDING OF THE DETAILED MOLECULAR MECHANISMS UNDERLYING OBESITY AND AID IN THE SELECTION OF POTENTIAL BIOMARKERS FOR OBESITY IN YOUTH. HERE, WE PERFORMED MICROARRAY-BASED DNA METHYLATION AND GENE EXPRESSION PROFILING OF PERIPHERAL WHITE BLOOD CELLS OBTAINED FROM SIX YOUNG, OBESE INDIVIDUALS AND SIX HEALTHY CONTROLS. WE OBSERVED THAT THE HIERARCHICAL CLUSTERING OF DNA METHYLATION, BUT NOT GENE EXPRESSION, CLEARLY SEGREGATES THE OBESE INDIVIDUALS FROM THE CONTROLS, SUGGESTING THAT THE METABOLIC DISTURBANCE THAT OCCURS AS A RESULT OF OBESITY AT A YOUNG AGE MAY AFFECT THE DNA METHYLATION OF PERIPHERAL BLOOD CELLS WITHOUT ACCOMPANYING TRANSCRIPTIONAL CHANGES. TO EXAMINE THE GENOME-WIDE DIFFERENCES IN THE DNA METHYLATION PROFILES OF YOUNG OBESE AND CONTROL INDIVIDUALS, WE IDENTIFIED DIFFERENTIALLY METHYLATED CPG SITES AND INVESTIGATED THEIR GENOMIC AND EPIGENOMIC CONTEXTS. THE ABERRANT DNA METHYLATION PATTERNS IN OBESE INDIVIDUALS CAN BE SUMMARIZED AS RELATIVE GAINS AND LOSSES OF DNA METHYLATION IN GENE PROMOTERS AND GENE BODIES, RESPECTIVELY. WE ALSO OBSERVED THAT THE CPG ISLANDS OF OBESE INDIVIDUALS ARE MORE SUSCEPTIBLE TO DNA METHYLATION COMPARED TO CONTROLS. OUR PILOT STUDY SUGGESTS THAT THE GENOME-WIDE ABERRANT DNA METHYLATION PATTERNS OF OBESE INDIVIDUALS MAY ADVANCE NOT ONLY OUR UNDERSTANDING OF THE EPIGENOMIC PATHOGENESIS BUT ALSO EARLY SCREENING OF OBESITY IN YOUTH. 2017 15 3 38 "EPIGENOME-WIDE METHYLATION PROFILE OF CHRONIC KIDNEY DISEASE-DERIVED ARTERIAL DNA UNCOVERS NOVEL PATHWAYS IN DISEASE-ASSOCIATED CARDIOVASCULAR PATHOLOGY.". CHRONIC KIDNEY DISEASE (CKD) RELATED CARDIOVASCULAR DISEASE (CVD) IS CHARACTERIZED BY VASCULAR REMODELLING WITH WELL-ESTABLISHED STRUCTURAL AND FUNCTIONAL CHANGES IN THE VASCULAR WALL SUCH AS ARTERIAL STIFFNESS, MATRIX DEPOSITION, AND CALCIFICATION. THESE PHENOTYPIC CHANGES RESEMBLE PATHOLOGY SEEN IN AGEING, AND ARE LIKELY TO BE MEDIATED BY SUSTAINED ALTERATIONS IN GENE EXPRESSION, WHICH MAY BE CAUSED BY EPIGENETIC CHANGES SUCH AS TISSUE-SPECIFIC DNA METHYLATION. WE AIMED TO INVESTIGATE TISSUE SPECIFIC CHANGES IN DNA METHYLATION THAT OCCUR IN CKD-RELATED CVD. GENOME-WIDE DNA METHYLATION CHANGES WERE EXAMINED IN BISULPHITE CONVERTED GENOMIC DNA ISOLATED FROM THE VASCULAR MEDIA OF CKD AND HEALTHY ARTERIES. METHYLATION-SPECIFIC PCR WAS USED TO VALIDATE THE ARRAY DATA, AND THE ASSOCIATION BETWEEN DNA METHYLATION AND GENE AND PROTEIN EXPRESSION WAS EXAMINED. THE DNA METHYLATION AGE WAS COMPARED TO THE CHRONOLOGICAL AGE IN BOTH CASES AND CONTROLS. THREE HUNDRED AND NINETEEN DIFFERENTIALLY METHYLATED REGIONS (DMR) WERE IDENTIFIED SPREAD ACROSS THE GENOME. PATHWAY ANALYSIS REVEALED THAT DMRS ASSOCIATED WITH GENES WERE INVOLVED IN EMBRYONIC AND VASCULAR DEVELOPMENT, AND SIGNALLING PATHWAYS SUCH AS TGFBETA AND FGF. EXPRESSION OF TOP DIFFERENTIALLY METHYLATED GENE HOXA5 SHOWED A SIGNIFICANT NEGATIVE CORRELATION WITH DNA METHYLATION. INTERESTINGLY, DNA METHYLATION AGE AND CHRONOLOGICAL AGE WERE HIGHLY CORRELATED, BUT THERE WAS NO EVIDENCE OF ACCELERATED AGE-RELATED DNA METHYLATION IN THE ARTERIES OF CKD PATIENTS. IN CONCLUSION, WE DEMONSTRATED THAT DIFFERENTIAL DNA METHYLATION IN THE ARTERIAL TISSUE OF CKD PATIENTS REPRESENTS A POTENTIAL MEDIATOR OF ARTERIAL PATHOLOGY AND MAY BE USED TO UNCOVER NOVEL PATHWAYS IN THE GENESIS OF CKD-ASSOCIATED COMPLICATIONS. 2021 16 1556 46 DNA METHYLATION MODIFICATIONS ASSOCIATED WITH CHRONIC FATIGUE SYNDROME. CHRONIC FATIGUE SYNDROME (CFS), ALSO KNOWN AS MYALGIC ENCEPHALOMYELITIS, IS A COMPLEX MULTIFACTORIAL DISEASE THAT IS CHARACTERIZED BY THE PERSISTENT PRESENCE OF FATIGUE AND OTHER PARTICULAR SYMPTOMS FOR A MINIMUM OF 6 MONTHS. SYMPTOMS FAIL TO DISSIPATE AFTER SUFFICIENT REST AND HAVE MAJOR EFFECTS ON THE DAILY FUNCTIONING OF CFS SUFFERERS. CFS IS A MULTI-SYSTEM DISEASE WITH A HETEROGENEOUS PATIENT POPULATION SHOWING A WIDE VARIETY OF FUNCTIONAL DISABILITIES AND ITS BIOLOGICAL BASIS REMAINS POORLY UNDERSTOOD. STABLE ALTERATIONS IN GENE FUNCTION IN THE IMMUNE SYSTEM HAVE BEEN REPORTED IN SEVERAL STUDIES OF CFS. EPIGENETIC MODIFICATIONS HAVE BEEN IMPLICATED IN LONG-TERM EFFECTS ON GENE FUNCTION, HOWEVER, TO OUR KNOWLEDGE, GENOME-WIDE EPIGENETIC MODIFICATIONS ASSOCIATED WITH CFS HAVE NOT BEEN EXPLORED. WE EXAMINED THE DNA METHYLOME IN PERIPHERAL BLOOD MONONUCLEAR CELLS ISOLATED FROM CFS PATIENTS AND HEALTHY CONTROLS USING THE ILLUMINA HUMANMETHYLATION450 BEADCHIP ARRAY, CONTROLLING FOR INVARIANT PROBES AND PROBES OVERLAPPING POLYMORPHIC SEQUENCES. GENE ONTOLOGY (GO) AND NETWORK ANALYSIS OF DIFFERENTIALLY METHYLATED GENES WAS PERFORMED TO DETERMINE POTENTIAL BIOLOGICAL PATHWAYS SHOWING CHANGES IN DNA METHYLATION IN CFS. WE FOUND AN INCREASED ABUNDANCE OF DIFFERENTIALLY METHYLATED GENES RELATED TO THE IMMUNE RESPONSE, CELLULAR METABOLISM, AND KINASE ACTIVITY. GENES ASSOCIATED WITH IMMUNE CELL REGULATION, THE LARGEST COORDINATED ENRICHMENT OF DIFFERENTIALLY METHYLATED PATHWAYS, SHOWED HYPOMETHYLATION WITHIN PROMOTERS AND OTHER GENE REGULATORY ELEMENTS IN CFS. THESE DATA ARE CONSISTENT WITH EVIDENCE OF MULTISYSTEM DYSREGULATION IN CFS AND IMPLICATE THE INVOLVEMENT OF DNA MODIFICATIONS IN CFS PATHOLOGY. 2014 17 2418 50 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 18 1577 36 DNA METHYLATION PROFILE IN CHRONIC MYELOMONOCYTIC LEUKEMIA ASSOCIATES WITH DISTINCT CLINICAL, BIOLOGICAL AND GENETIC FEATURES. CHROMOSOMAL ABNORMALITIES ARE DETECTED IN 20-30% OF PATIENTS WITH CHRONIC MYELOMONOCYTIC LEUKEMIA (CMML) AND CORRELATE WITH PROGNOSIS. ON THE MUTATION LEVEL, DISRUPTIVE ALTERATIONS ARE PARTICULARLY FREQUENT IN CHROMATIN REGULATORY GENES. HOWEVER, LITTLE IS KNOWN ABOUT THE CONSEQUENTIAL ALTERATIONS IN THE EPIGENETIC MARKING OF THE GENOME. HERE, WE REPORT THE ANALYSIS OF GENOMIC DNA METHYLATION PATTERNS OF 64 CMML PATIENTS AND 10 HEALTHY CONTROLS, USING A DNA METHYLATION MICROARRAY FOCUSED ON PROMOTER REGIONS. DIFFERENTIAL METHYLATION ANALYSIS BETWEEN PATIENTS AND CONTROLS ALLOWED US TO IDENTIFY ABNORMALITIES IN DNA METHYLATION, INCLUDING HYPERMETHYLATION OF SPECIFIC GENES AND LARGE GENOME REGIONS WITH ABERRANT DNA METHYLATION. UNSUPERVISED HIERARCHICAL CLUSTER ANALYSIS IDENTIFIED TWO MAIN CLUSTERS THAT ASSOCIATED WITH THE CLINICAL, BIOLOGICAL, AND GENETIC FEATURES OF PATIENTS. GROUP 1 WAS ENRICHED IN PATIENTS WITH ADVERSE CLINICAL AND BIOLOGICAL CHARACTERISTICS AND POORER OVERALL AND PROGRESSION-FREE SURVIVAL. IN ADDITION, SIGNIFICANT DIFFERENCES IN DNA METHYLATION WERE OBSERVED BETWEEN PATIENTS WITH LOW RISK AND INTERMEDIATE/HIGH RISK KARYOTYPES AND BETWEEN TET2 MUTANT AND WILD TYPE PATIENTS. TAKEN TOGETHER, OUR RESULTS DEMONSTRATE THAT ALTERED DNA METHYLATION PATTERNS REFLECT THE CMML DISEASE STATE AND ALLOW TO IDENTIFY PATIENT GROUPS WITH DISTINCT CLINICAL FEATURES. 2018 19 1599 42 DNA METHYLATION SIGNATURE OF CHILDHOOD CHRONIC PHYSICAL AGGRESSION IN T CELLS OF BOTH MEN AND WOMEN. BACKGROUND: HIGH FREQUENCY OF PHYSICAL AGGRESSION IS THE CENTRAL FEATURE OF SEVERE CONDUCT DISORDER AND IS ASSOCIATED WITH A WIDE RANGE OF SOCIAL, MENTAL AND PHYSICAL HEALTH PROBLEMS. WE HAVE PREVIOUSLY TESTED THE HYPOTHESIS THAT DIFFERENTIAL DNA METHYLATION SIGNATURES IN PERIPHERAL T CELLS ARE ASSOCIATED WITH A CHRONIC AGGRESSION TRAJECTORY IN MALES. DESPITE THE FACT THAT SEX DIFFERENCES APPEAR TO PLAY A PIVOTAL ROLE IN DETERMINING THE DEVELOPMENT, MAGNITUDE AND FREQUENCY OF AGGRESSION, MOST OF PREVIOUS STUDIES FOCUSED ON MALES, SO LITTLE IS KNOWN ABOUT FEMALE CHRONIC PHYSICAL AGGRESSION. WE THEREFORE TESTED HERE WHETHER OR NOT THERE IS A SIGNATURE OF PHYSICAL AGGRESSION IN FEMALE DNA METHYLATION AND, IF THERE IS, HOW IT RELATES TO THE SIGNATURE OBSERVED IN MALES. METHODOLOGY/PRINCIPAL FINDINGS: METHYLATION PROFILES WERE CREATED USING THE METHOD OF METHYLATED DNA IMMUNOPRECIPITATION (MEDIP) FOLLOWED BY MICROARRAY HYBRIDIZATION AND STATISTICAL AND BIOINFORMATIC ANALYSES ON T CELL DNA OBTAINED FROM ADULT WOMEN WHO WERE FOUND TO BE ON A CHRONIC PHYSICAL AGGRESSION TRAJECTORY (CPA) BETWEEN 6 AND 12 YEARS OF AGE COMPARED TO WOMEN WHO FOLLOWED A NORMAL PHYSICAL AGGRESSION TRAJECTORY. WE CONFIRMED THE EXISTENCE OF A WELL-DEFINED, GENOME-WIDE SIGNATURE OF DNA METHYLATION ASSOCIATED WITH CHRONIC PHYSICAL AGGRESSION IN THE PERIPHERAL T CELLS OF ADULT FEMALES THAT INCLUDES MANY OF THE GENES SIMILARLY ASSOCIATED WITH PHYSICAL AGGRESSION IN THE SAME CELL TYPES OF ADULT MALES. CONCLUSIONS: THIS STUDY IN A SMALL NUMBER OF WOMEN PRESENTS PRELIMINARY EVIDENCE FOR A GENOME-WIDE VARIATION IN PROMOTER DNA METHYLATION THAT ASSOCIATES WITH CPA IN WOMEN THAT WARRANT LARGER STUDIES FOR FURTHER VERIFICATION. A SIGNIFICANT PROPORTION OF THESE ASSOCIATIONS WERE PREVIOUSLY OBSERVED IN MEN WITH CPA SUPPORTING THE HYPOTHESIS THAT THE EPIGENETIC SIGNATURE OF EARLY LIFE AGGRESSION IN FEMALES IS COMPOSED OF A COMPONENT SPECIFIC TO FEMALES AND ANOTHER COMMON TO BOTH MALES AND FEMALES. 2014 20 3068 41 GENOME-WIDE DNA METHYLATION PROFILING IDENTIFIES DIFFERENTIAL METHYLATION IN UNINVOLVED PSORIATIC EPIDERMIS. PSORIASIS IS A CHRONIC INFLAMMATORY SKIN DISEASE WITH BOTH LOCAL AND SYSTEMIC COMPONENTS. GENOME-WIDE APPROACHES HAVE IDENTIFIED MORE THAN 60 PSORIASIS-SUSCEPTIBILITY LOCI, BUT GENES ARE ESTIMATED TO EXPLAIN ONLY ONE-THIRD OF THE HERITABILITY IN PSORIASIS, SUGGESTING ADDITIONAL, YET UNIDENTIFIED, SOURCES OF HERITABILITY. EPIGENETIC MODIFICATIONS HAVE BEEN LINKED TO PSORIASIS AND ALTERED DNA METHYLATION PATTERNS IN PSORIATIC VERSUS HEALTHY SKIN HAVE BEEN REPORTED IN WHOLE-SKIN BIOPSIES. IN THIS STUDY, FOCUSING ON EPIGENETIC MODIFICATIONS IN THE PSORIATIC UNINVOLVED SKIN, WE COMPARED THE LESIONAL AND NON-LESIONAL EPIDERMIS FROM PSORIASIS PATIENTS WITH EPIDERMIS FROM HEALTHY CONTROLS. WE PERFORMED AN EXHAUSTIVE GENOME-WIDE DNA METHYLATION PROFILING USING REDUCED REPRESENTATION BISULFITE SEQUENCING, WHICH INTERROGATES THE METHYLATION STATUS OF APPROXIMATELY 3-4 MILLION CPG SITES. MORE THAN 2,000 STRONGLY DIFFERENTIALLY METHYLATED SITES WERE IDENTIFIED AND A STRIKING OVERREPRESENTATION OF THE WNT AND CADHERIN PATHWAYS AMONG THE DIFFERENTIALLY METHYLATED SITES WAS FOUND. IN PARTICULAR, WE OBSERVE A STRONG DIFFERENTIAL METHYLATION IN SEVERAL PSORIASIS CANDIDATE GENES. A SUBSTANTIAL NUMBER OF DIFFERENTIALLY METHYLATED SITES PRESENT IN THE UNINVOLVED VERSUS HEALTHY EPIDERMIS SUGGESTS THE PRESENCE OF A PRE-PSORIATIC STATE IN THE CLINICALLY HEALTHY SKIN TYPE. OUR EXPLORATORY STUDY REPRESENTS A STARTING POINT FOR IDENTIFYING BIOMARKERS FOR PSORIASIS-PRONE SKIN BEFORE DISEASE ONSET. 2018