1  404 184 ANALYSIS OF EPIGENETIC AGE PREDICTORS IN PAIN-RELATED CONDITIONS. CHRONIC PAIN PREVALENCE IS HIGH WORLDWIDE AND INCREASES AT OLDER AGES. SIGNS OF PREMATURE AGING HAVE BEEN ASSOCIATED WITH CHRONIC PAIN, BUT FEW STUDIES HAVE INVESTIGATED AGING BIOMARKERS IN PAIN-RELATED CONDITIONS. A SET OF DNA METHYLATION (DNAM)-BASED ESTIMATES OF AGE, CALLED "EPIGENETIC CLOCKS," HAS BEEN PROPOSED AS BIOLOGICAL MEASURES OF AGE-RELATED ADVERSE PROCESSES, MORBIDITY, AND MORTALITY. THE AIM OF THIS STUDY IS TO ASSESS IF DIFFERENT PAIN-RELATED PHENOTYPES SHOW ALTERATIONS IN DNAM AGE. IN OUR ANALYSIS, WE CONSIDERED THREE COHORTS FOR WHICH WHOLE-BLOOD DNAM DATA WERE AVAILABLE: HEAT PAIN SENSITIVITY (HPS), INCLUDING 20 MONOZYGOTIC TWIN PAIRS DISCORDANT FOR HEAT PAIN TEMPERATURE THRESHOLD; FIBROMYALGIA (FM), INCLUDING 24 CASES AND 20 CONTROLS; AND HEADACHE, INCLUDING 22 CHRONIC MIGRAINE AND MEDICATION OVERUSE HEADACHE PATIENTS (MOH), 18 EPISODIC MIGRAINEURS (EM), AND 13 HEALTHY SUBJECTS. WE USED THE HORVATH'S EPIGENETIC AGE CALCULATOR TO OBTAIN DNAM-BASED ESTIMATES OF EPIGENETIC AGE, TELOMERE LENGTH, LEVELS OF 7 PROTEINS IN PLASMA, NUMBER OF SMOKED PACKS OF CIGARETTES PER YEAR, AND BLOOD CELL COUNTS. WE DID NOT FIND DIFFERENCES IN EPIGENETIC AGE ACCELERATION, CALCULATED USING FIVE DIFFERENT EPIGENETIC CLOCKS, BETWEEN SUBJECTS DISCORDANT FOR PAIN-RELATED PHENOTYPES. TWINS WITH HIGH HPS HAD INCREASED CD8+ T CELL COUNTS (NOMINAL P = 0.028). HPS THRESHOLDS WERE NEGATIVELY ASSOCIATED WITH ESTIMATED LEVELS OF GDF15 (NOMINAL P = 0.008). FM PATIENTS SHOWED DECREASED NAIVE CD4+ T CELL COUNTS COMPARED WITH CONTROLS (NOMINAL P = 0.015). THE SEVERITY OF FM MANIFESTATIONS EXPRESSED THROUGH VARIOUS EVALUATION TESTS WAS ASSOCIATED WITH DECREASED LEVELS OF LEPTIN, SHORTER LENGTH OF TELOMERES, AND REDUCED CD8+ T AND NATURAL KILLER CELL COUNTS (NOMINAL P < 0.05), WHILE THE DURATION OF PAINFUL SYMPTOMS WAS POSITIVELY ASSOCIATED WITH TELOMERE LENGTH (NOMINAL P = 0.034). NO DIFFERENCES IN DNAM-BASED ESTIMATES WERE DETECTED FOR MOH OR EM COMPARED WITH CONTROLS. IN SUMMARY, OUR STUDY SUGGESTS THAT HPS, FM, AND MOH/EM DO NOT SHOW SIGNS OF EPIGENETIC AGE ACCELERATION IN WHOLE BLOOD, WHILE HPS AND FM ARE ASSOCIATED WITH DNAM-BASED ESTIMATES OF IMMUNOLOGICAL PARAMETERS, PLASMA PROTEINS, AND TELOMERE LENGTH. FUTURE STUDIES SHOULD EXTEND THESE OBSERVATIONS IN LARGER COHORTS.	2020	
                                       
2 5395  47 REDUCED EPIGENETIC AGE IN OLDER ADULTS WITH HIGH SENSE OF PURPOSE IN LIFE. PSYCHOSOCIAL RISK FACTORS HAVE BEEN LINKED WITH ACCELERATED EPIGENETIC AGING, BUT LITTLE IS KNOWN ABOUT WHETHER PSYCHOSOCIAL RESILIENCE FACTORS (EG, SENSE OF PURPOSE IN LIFE) MIGHT REDUCE EPIGENETIC AGE ACCELERATION. IN THIS STUDY, WE TESTED IF OLDER ADULTS WHO EXPERIENCE HIGH LEVELS OF PURPOSE MIGHT SHOW REDUCED EPIGENETIC AGE ACCELERATION. WE EVALUATED THE RELATIONSHIP BETWEEN PURPOSE AND EPIGENETIC AGE ACCELERATION AS MEASURED BY 13 DNA METHYLATION (DNAM) "EPIGENETIC CLOCKS" ASSESSED IN 1 572 OLDER ADULTS FROM THE HEALTH AND RETIREMENT STUDY (MEAN AGE 70 YEARS). WE QUANTIFIED THE TOTAL ASSOCIATION BETWEEN PURPOSE AND DNAM AGE ACCELERATION AS WELL AS THE EXTENT TO WHICH THAT TOTAL ASSOCIATION MIGHT BE ATTRIBUTABLE TO DEMOGRAPHIC FACTORS, CHRONIC DISEASE, OTHER PSYCHOSOCIAL VARIABLES (EG, POSITIVE AFFECT), AND HEALTH-RELATED BEHAVIORS (HEAVY DRINKING, SMOKING, PHYSICAL ACTIVITY, AND BODY MASS INDEX [BMI]). PURPOSE IN LIFE WAS ASSOCIATED WITH REDUCED EPIGENETIC AGE ACCELERATION ACROSS 4 "SECOND-GENERATION" DNAM CLOCKS OPTIMIZED FOR PREDICTING HEALTH AND LONGEVITY (FALSE DISCOVERY RATE [FDR] Q < 0.0001: PHENOAGE, GRIMAGE, ZHANG EPIGENETIC MORTALITY INDEX; FDR Q < 0.05: DUNEDINPOAM). THESE ASSOCIATIONS WERE INDEPENDENT OF DEMOGRAPHIC AND PSYCHOSOCIAL FACTORS, BUT SUBSTANTIALLY ATTENUATED AFTER ADJUSTING FOR HEALTH-RELATED BEHAVIORS (DRINKING, SMOKING, PHYSICAL ACTIVITY, AND BMI). PURPOSE SHOWED NO SIGNIFICANT ASSOCIATION WITH 9 "FIRST-GENERATION" DNAM EPIGENETIC CLOCKS TRAINED ON CHRONOLOGICAL AGE. OLDER ADULTS WITH GREATER PURPOSE IN LIFE SHOW "YOUNGER" DNAM EPIGENETIC AGE ACCELERATION. THESE RESULTS MAY BE DUE IN PART TO ASSOCIATED DIFFERENCES IN HEALTH-RELATED BEHAVIORS. RESULTS SUGGEST NEW OPPORTUNITIES TO REDUCE BIOLOGICAL AGE ACCELERATION BY ENHANCING PURPOSE AND ITS BEHAVIORAL SEQUELAE IN LATE ADULTHOOD.	2023	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
3  173  50 ACCELERATED AGING IN BIPOLAR DISORDERS: AN EXPLORATORY STUDY OF SIX EPIGENETIC CLOCKS. BIPOLAR DISORDER (BD) IS A CHRONIC AND SEVERE PSYCHIATRIC DISORDER ASSOCIATED WITH SIGNIFICANT MEDICAL MORBIDITY AND REDUCED LIFE EXPECTANCY. IN THIS STUDY, WE ASSESSED ACCELERATED EPIGENETIC AGING IN INDIVIDUALS WITH BD USING VARIOUS DNA METHYLATION (DNAM)-BASED MARKERS. FOR THIS PURPOSE, WE USED FIVE EPIGENETIC CLOCKS (HORVATH, HANNUM, EN, PHENOAGE, AND GRIMAGE) AND A DNAM-BASED TELOMERE LENGTH CLOCK (DNAMTL). DNAM PROFILES WERE OBTAINED USING INFINIUM METHYLATIONEPIC ARRAYS FROM WHOLE-BLOOD SAMPLES OF 184 INDIVIDUALS WITH BD. WE ALSO ESTIMATED BLOOD CELL COUNTS BASED ON DNAM LEVELS FOR ADJUSTMENT. SIGNIFICANT CORRELATIONS BETWEEN CHRONOLOGICAL AGE AND EACH EPIGENETIC AGE ESTIMATED USING THE SIX DIFFERENT CLOCKS WERE OBSERVED. FOLLOWING ADJUSTMENT FOR BLOOD CELL COUNTS, WE FOUND THAT THE SIX EPIGENETIC AGEACCELS (AGE ACCELERATIONS) WERE SIGNIFICANTLY ASSOCIATED WITH THE BODY MASS INDEX. GRIMAGE AGEACCEL WAS SIGNIFICANTLY ASSOCIATED WITH MALE SEX, SMOKING STATUS AND CHILDHOOD MALTREATMENT. DNAMTL AGEACCEL WAS SIGNIFICANTLY ASSOCIATED WITH SMOKING STATUS. OVERALL, THIS STUDY SHOWED THAT DISTINCT EPIGENETIC CLOCKS ARE SENSITIVE TO DIFFERENT ASPECTS OF AGING PROCESS IN BD. FURTHER INVESTIGATIONS WITH COMPREHENSIVE EPIGENETIC CLOCK ANALYSES AND LARGE SAMPLES ARE REQUIRED TO CONFIRM OUR FINDINGS OF POTENTIAL DETERMINANTS OF AN ACCELERATED EPIGENETIC AGING IN BD.	2023	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
4 1497  41 DNA METHYLATION AGE IS ACCELERATED IN ALCOHOL DEPENDENCE. ALCOHOL DEPENDENCE (ALC) IS A CHRONIC, RELAPSING DISORDER THAT INCREASES THE BURDEN OF CHRONIC DISEASE AND SIGNIFICANTLY CONTRIBUTES TO NUMEROUS PREMATURE DEATHS EACH YEAR. PREVIOUS RESEARCH SUGGESTS THAT CHRONIC, HEAVY ALCOHOL CONSUMPTION IS ASSOCIATED WITH DIFFERENTIAL DNA METHYLATION PATTERNS. IN ADDITION, DNA METHYLATION LEVELS AT CERTAIN CPG SITES HAVE BEEN CORRELATED WITH AGE. WE USED AN EPIGENETIC CLOCK TO INVESTIGATE THE POTENTIAL ROLE OF EXCESSIVE ALCOHOL CONSUMPTION IN EPIGENETIC AGING. WE EXPLORED THIS QUESTION IN FIVE INDEPENDENT COHORTS, INCLUDING DNA METHYLATION DATA DERIVED FROM DATASETS FROM BLOOD (N = 129, N = 329), LIVER (N = 92, N = 49), AND POSTMORTEM PREFRONTAL CORTEX (N = 46). ONE BLOOD DATASET AND ONE LIVER TISSUE DATASET OF INDIVIDUALS WITH ALC EXHIBITED POSITIVE AGE ACCELERATION (P < 0.0001 AND P = 0.0069, RESPECTIVELY), WHEREAS THE OTHER BLOOD AND LIVER TISSUE DATASETS BOTH EXHIBITED TRENDS OF POSITIVE AGE ACCELERATION THAT WERE NOT SIGNIFICANT (P = 0.83 AND P = 0.57, RESPECTIVELY). PREFRONTAL CORTEX TISSUE EXHIBITED A TREND OF NEGATIVE AGE ACCELERATION (P = 0.19). THESE RESULTS SUGGEST THAT EXCESSIVE ALCOHOL CONSUMPTION MAY BE ASSOCIATED WITH EPIGENETIC AGING IN A TISSUE-SPECIFIC MANNER AND WARRANTS FURTHER INVESTIGATION USING MULTIPLE TISSUE SAMPLES FROM THE SAME INDIVIDUALS.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
5 2734  49 EXPLORING THE RELATIONSHIP BETWEEN DNA METHYLATION AGE MEASURES AND PSYCHONEUROLOGICAL SYMPTOMS IN WOMEN WITH EARLY-STAGE BREAST CANCER. PURPOSE: THE EPIGENETIC CLOCK HAS BEEN ACKNOWLEDGED AS AN INDICATOR FOR MOLECULAR AGING, BUT FEW STUDIES HAVE EXAMINED POSSIBLE ASSOCIATIONS OF DNA METHYLATION (DNAM) AGE OR AGE ACCELERATION (AA) WITH SYMPTOM BURDEN IN INDIVIDUALS WHO ARE TREATED FOR CANCER. THIS STUDY EXPLORED THE ASSOCIATION OF DNAM AGE OR AA WITH PSYCHONEUROLOGICAL (PN) SYMPTOMS, INCLUDING COGNITIVE IMPAIRMENT, FATIGUE, SLEEP DISTURBANCES, PAIN, AND DEPRESSIVE SYMPTOMS, IN BREAST CANCER SURVIVORS OVER A 2-YEAR PERIOD. METHODS: WE MEASURED PN SYMPTOMS USING RELIABLE INSTRUMENTS AND DNAM LEVELS BY INFINIUM HUMANMETHYLATION450K BEADCHIP (N = 72). DNAM AGE WAS CALCULATED BY THE HORVATH, GRIM, AND HANNUM-BASED INTRINSIC AND EXTRINSIC AGE ESTIMATIONS. AA WAS DEFINED BY THE RESIDUAL REGRESSING ESTIMATED EPIGENETIC AGE ON CHRONOLOGICAL AGE. MIXED REGRESSION MODELS WERE FITTED FOR AA AND CHANGES IN AA TO STUDY THE ASSOCIATION OVER TIME. SEPARATE LINEAR REGRESSION MODELS AND A MIXED-EFFECTS MODEL WERE FITTED FOR AA AT EACH TIME POINT. RESULTS: HORVATH-AA, GRIM-AA, AND EXTRINSIC EPIGENETIC AA WERE SIGNIFICANTLY CHANGED OVER TIME, WHILE INTRINSIC EPIGENETIC AA DID NOT EXHIBIT ANY TEMPORAL CHANGES. INCREASED AA WAS ASSOCIATED WITH GREATER ANXIETY AND FATIGUE, AS WELL AS WORSE COGNITIVE MEMORY, ADJUSTING FOR RACE, BMI, INCOME, CHEMOTHERAPY, RADIATION THERAPY, AND CHRONOLOGICAL AGE. INCREASED DNAM AGE WAS ASSOCIATED WITH GREATER ANXIETY OVER 2 YEARS. CONCLUSION: OUR FINDINGS SUGGEST DNAM AGE AND AA MAY BE ASSOCIATED WITH PN SYMPTOMS OVER THE COURSE OF CANCER TREATMENT AND SURVIVORSHIP. SOME PN SYMPTOMS MAY BE AMENABLE TO PREVENTIVE INTERVENTIONS TARGETED TO EPIGENETIC CLOCKS THAT INFLUENCE AGING-ASSOCIATED PROCESSES.	2022	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   
6 5957  41 TELOMERE LENGTH AND EPIGENETIC AGE ACCELERATION IN ADOLESCENTS WITH ANXIETY DISORDERS. EVIDENCE ON THE RELATIONSHIP BETWEEN GENETICS AND MENTAL HEALTH ARE FLOURISHING. HOWEVER, FEW STUDIES ARE EVALUATING EARLY BIOMARKERS THAT MIGHT LINK GENES, ENVIRONMENT, AND PSYCHOPATHOLOGY. WE AIMED TO STUDY TELOMERE LENGTH (TL) AND EPIGENETIC AGE ACCELERATION (AA) IN A COHORT OF ADOLESCENTS WITH AND WITHOUT ANXIETY DISORDERS (N = 234). WE EVALUATED A REPRESENTATIVE SUBSAMPLE OF PARTICIPANTS AT BASELINE AND AFTER 5 YEARS (N = 76) AND CATEGORIZED THEM ACCORDING TO THEIR ANXIETY DISORDER DIAGNOSIS AT BOTH TIME POINTS: (1) CONTROL GROUP (NO ANXIETY DISORDER, N = 18), (2) VARIABLE GROUP (ANXIETY DISORDER IN ONE EVALUATION, N = 38), AND (3) PERSISTENT GROUP (ANXIETY DISORDER AT BOTH TIME POINTS, N = 20). WE ASSESSED RELATIVE MEAN TL BY REAL-TIME QUANTITATIVE PCR AND DNA METHYLATION BY INFINIUM HUMANMETHYLATION450 BEADCHIP. WE CALCULATED AA USING THE HORVATH AGE ESTIMATION ALGORITHM AND ANALYZED DIFFERENCES AMONG GROUPS USING GENERALIZED LINEAR MIXED MODELS. THE PERSISTENT GROUP OF ANXIETY DISORDER DID NOT CHANGE TL OVER TIME (P = 0.495). THE VARIABLE GROUP HAD HIGHER BASELINE TL (P = 0.003) BUT NO ACCELERATED TL EROSION IN COMPARISON TO THE NON-ANXIETY CONTROL GROUP (P = 0.053). FURTHERMORE, THERE WERE NO DIFFERENCES IN AA AMONG GROUPS OVER TIME. OUR FINDINGS SUGGEST THAT ADOLESCENTS WITH CHRONIC ANXIETY DID NOT CHANGE TELOMERE LENGTH OVER TIME, WHICH COULD BE RELATED TO A DELAY IN NEURONAL DEVELOPMENT IN THIS PERIOD OF LIFE.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
7 2079  35 EPIGENETIC DNA METHYLATION CHANGES ASSOCIATED WITH HEADACHE CHRONIFICATION: A RETROSPECTIVE CASE-CONTROL STUDY. BACKGROUND THE BIOLOGICAL MECHANISMS OF HEADACHE CHRONIFICATION ARE POORLY UNDERSTOOD. WE AIMED TO IDENTIFY CHANGES IN DNA METHYLATION ASSOCIATED WITH THE TRANSFORMATION FROM EPISODIC TO CHRONIC HEADACHE. METHODS PARTICIPANTS WERE RECRUITED FROM THE POPULATION-BASED NORWEGIAN HUNT STUDY. THIRTY-SIX FEMALE HEADACHE PATIENTS WHO TRANSFORMED FROM EPISODIC TO CHRONIC HEADACHE BETWEEN BASELINE AND FOLLOW-UP 11 YEARS LATER WERE MATCHED AGAINST 35 CONTROLS WITH EPISODIC HEADACHE. DNA METHYLATION WAS QUANTIFIED AT 485,000 CPG SITES, AND CHANGES IN METHYLATION LEVEL AT THESE SITES WERE COMPARED BETWEEN CASES AND CONTROLS BY LINEAR REGRESSION ANALYSIS. DATA WERE ANALYZED IN TWO STAGES (STAGES 1 AND 2) AND IN A COMBINED META-ANALYSIS. RESULTS NONE OF THE TOP 20 CPG SITES IDENTIFIED IN STAGE 1 REPLICATED IN STAGE 2 AFTER MULTIPLE TESTING CORRECTION. IN THE COMBINED META-ANALYSIS THE STRONGEST ASSOCIATED CPG SITES WERE RELATED TO SH2D5 AND NPTX2, TWO BRAIN-EXPRESSED GENES INVOLVED IN THE REGULATION OF SYNAPTIC PLASTICITY. FUNCTIONAL ENRICHMENT ANALYSIS POINTED TO PROCESSES INCLUDING CALCIUM ION BINDING AND ESTROGEN RECEPTOR PATHWAYS. CONCLUSION IN THIS FIRST GENOME-WIDE STUDY OF DNA METHYLATION IN HEADACHE CHRONIFICATION SEVERAL POTENTIALLY IMPLICATED LOCI AND PROCESSES WERE IDENTIFIED. THE STUDY EXEMPLIFIES THE USE OF PROSPECTIVELY COLLECTED POPULATION COHORTS TO SEARCH FOR EPIGENETIC MECHANISMS OF DISEASE.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
8 1957  50 EPIGENETIC AGE PREDICTORS IN COMMUNITY-DWELLING ADULTS WITH HIGH IMPACT KNEE PAIN. GERONTOLOGICAL RESEARCH REVEALS CONSIDERABLE INTERINDIVIDUAL VARIABILITY IN AGING PHENOTYPES, AND EMERGING EVIDENCE SUGGESTS THAT HIGH IMPACT CHRONIC PAIN MAY BE ASSOCIATED WITH VARIOUS ACCELERATED BIOLOGICAL AGING PROCESSES. IN PARTICULAR, EPIGENETIC AGING IS A ROBUST PREDICTOR OF HEALTH-SPAN AND DISABILITY COMPARED TO CHRONOLOGICAL AGE ALONE. THE CURRENT STUDY AIMED TO DETERMINE WHETHER SEVERAL EPIGENETIC AGING BIOMARKERS WERE ASSOCIATED WITH HIGH IMPACT CHRONIC PAIN IN MIDDLE TO OLDER AGE ADULTS (44-78 YEARS OLD). PARTICIPANTS (N = 213) UNDERWENT A BLOOD DRAW, DEMOGRAPHIC, PSYCHOSOCIAL, PAIN AND FUNCTIONAL ASSESSMENTS. WE ESTIMATED FIVE EPIGENETIC CLOCKS AND CALCULATED THE DIFFERENCE BETWEEN EPIGENETIC AGE AND CHRONOLOGICAL AGE, WHICH HAS BEEN PREVIOUSLY REPORTED TO PREDICT OVERALL MORTALITY RISK, AS WELL AS INCLUDED ADDITIONAL DERIVED VARIABLES OF EPIGENETIC AGE PREVIOUSLY ASSOCIATED WITH PAIN. THERE WERE SIGNIFICANT DIFFERENCES ACROSS PAIN IMPACT GROUPS IN THREE OUT OF THE FIVE EPIGENETIC CLOCKS EXAMINED (DNAMAGE, DNAMPHENOAGE AND DNAMGRIMAGE), INDICATING THAT PAIN-RELATED DISABILITY DURING THE PAST 6 MONTHS WAS ASSOCIATED WITH MARKERS OF EPIGENETIC AGING. ONLY DNAMPHENOAGE AND DNAMGRIMAGE WERE ASSOCIATED WITH HIGHER KNEE PAIN INTENSITY DURING THE PAST 48 H. FINALLY, PAIN CATASTROPHIZING, DEPRESSIVE SYMPTOMATOLOGY AND MORE NEUROPATHIC PAIN SYMPTOMS WERE SIGNIFICANTLY ASSOCIATED WITH AN OLDER EPIGENOME IN ONLY ONE OF THE FIVE EPIGENETIC CLOCKS (I.E. DNAMGRIMAGE) AFTER CORRECTING FOR MULTIPLE COMPARISONS (CORRECTED P'S < 0.05). GIVEN THE SCANT LITERATURE IN RELATION TO EPIGENETIC AGING AND THE COMPLEX EXPERIENCE OF PAIN, ADDITIONAL RESEARCH IS NEEDED TO UNDERSTAND WHETHER EPIGENETIC AGING MAY HELP IDENTIFY PEOPLE WITH CHRONIC PAIN AT GREATER RISK OF FUNCTIONAL DECLINE AND POORER HEALTH OUTCOMES.	2022	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
9 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	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
10 2485  44 EPIGENETIC-BASED AGE ACCELERATION IN A REPRESENTATIVE SAMPLE OF OLDER AMERICANS: ASSOCIATIONS WITH AGING-RELATED MORBIDITY AND MORTALITY. BIOMARKERS DEVELOPED FROM DNA METHYLATION (DNAM) DATA ARE OF GROWING INTEREST AS PREDICTORS OF HEALTH OUTCOMES AND MORTALITY IN OLDER POPULATIONS. HOWEVER, IT IS UNKNOWN HOW EPIGENETIC AGING FITS WITHIN THE CONTEXT OF KNOWN SOCIOECONOMIC AND BEHAVIORAL ASSOCIATIONS WITH AGING-RELATED HEALTH OUTCOMES IN A LARGE, POPULATION-BASED, AND DIVERSE SAMPLE. THIS STUDY USES DATA FROM A REPRESENTATIVE, PANEL STUDY OF US OLDER ADULTS TO EXAMINE THE RELATIONSHIP BETWEEN DNAM-BASED AGE ACCELERATION MEASURES IN THE PREDICTION OF CROSS-SECTIONAL AND LONGITUDINAL HEALTH OUTCOMES AND MORTALITY. WE EXAMINE WHETHER RECENT IMPROVEMENTS TO THESE SCORES, USING PRINCIPAL COMPONENT (PC)-BASED MEASURES DESIGNED TO REMOVE SOME OF THE TECHNICAL NOISE AND UNRELIABILITY IN MEASUREMENT, IMPROVE THE PREDICTIVE CAPABILITY OF THESE MEASURES. WE ALSO EXAMINE HOW WELL DNAM-BASED MEASURES PERFORM AGAINST WELL-KNOWN PREDICTORS OF HEALTH OUTCOMES SUCH AS DEMOGRAPHICS, SES, AND HEALTH BEHAVIORS. IN OUR SAMPLE, AGE ACCELERATION CALCULATED USING "SECOND AND THIRD GENERATION CLOCKS," PHENOAGE, GRIMAGE, AND DUNEDINPACE, IS CONSISTENTLY A SIGNIFICANT PREDICTOR OF HEALTH OUTCOMES INCLUDING CROSS-SECTIONAL COGNITIVE DYSFUNCTION, FUNCTIONAL LIMITATIONS AND CHRONIC CONDITIONS ASSESSED 2 Y AFTER DNAM MEASUREMENT, AND 4-Y MORTALITY. PC-BASED EPIGENETIC AGE ACCELERATION MEASURES DO NOT SIGNIFICANTLY CHANGE THE RELATIONSHIP OF DNAM-BASED AGE ACCELERATION MEASURES TO HEALTH OUTCOMES OR MORTALITY COMPARED TO EARLIER VERSIONS OF THESE MEASURES. WHILE THE USEFULNESS OF DNAM-BASED AGE ACCELERATION AS A PREDICTOR OF LATER LIFE HEALTH OUTCOMES IS QUITE CLEAR, OTHER FACTORS SUCH AS DEMOGRAPHICS, SES, MENTAL HEALTH, AND HEALTH BEHAVIORS REMAIN EQUALLY, IF NOT MORE ROBUST, PREDICTORS OF LATER LIFE OUTCOMES.	2023	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      
11 6027  35 THE BLOOD DNA METHYLATION CLOCK GRIMAGE IS A ROBUST SURROGATE FOR AIRWAY EPITHELIA AGING. ONE KEY FEATURE OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS THAT ITS PREVALENCE INCREASES EXPONENTIALLY WITH AGE. DNA METHYLATION CLOCKS HAVE BECOME POWERFUL BIOMARKERS TO DETECT ACCELERATED AGING IN A VARIETY OF DISEASES AND CAN HELP PROGNOSE OUTCOMES IN SEVERE COPD. THIS STUDY INVESTIGATED WHICH DNA METHYLATION CLOCK COULD BEST REFLECT AIRWAY EPIGENETIC AGE WHEN USED IN MORE ACCESSIBLE BLOOD SAMPLES. OUR ANALYSES SHOWED THAT OUT OF SIX DNA METHYLATION CLOCKS INVESTIGATED, DNAMGRIMAGE DEMONSTRATED THE STRONGEST CORRELATION AND THE SMALLEST DIFFERENCE BETWEEN THE AIRWAY EPITHELIUM AND BLOOD. OUR FINDINGS SUGGESTS THAT BLOOD DNAMGRIMAGE ACCURATELY REFLECTS AIRWAY EPIGENETIC AGE OF INDIVIDUALS AND THAT ITS ELEVATION IS HIGHLY ASSOCIATED WITH COPD.	2022	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
12 3929  33 LIVER EPIGENOME CHANGES IN PATIENTS WITH HEPATOPULMONARY SYNDROME: A PILOT STUDY. THE HEPATOPULMONARY SYNDROME (HPS) IS DEFINED BY THE PRESENCE OF PULMONARY GAS EXCHANGE ABNORMALITIES DUE TO INTRAPULMONARY VASCULAR DILATATIONS IN PATIENTS WITH CHRONIC LIVER DISEASE. CHANGES IN DNA METHYLATION REFLECT THE GENOMIC VARIATION. SINCE LIVER TRANSPLANT (LT) REVERTS HPS WE HYPOTHESIZED THAT IT MAY BE ASSOCIATED WITH SPECIFIC LIVER EPIGENETIC CHANGES. THUS, THE AIM OF THIS STUDY WAS TO INVESTIGATE THE ROLE OF THE LIVER EPIGENOME IN PATIENTS WITH HPS. WE EXTRACTED DNA FROM PARAFFIN EMBEDDED LIVER TISSUE SAMPLES FROM 10 PATIENTS WITH HPS AND 10 AGE-, SEX- AND MELD (MODEL FOR END-STAGE LIVER DISEASE)-MATCHED CONTROLS. DNA METHYLATION WAS DETERMINED USING THE 850K ARRAY (ILLUMINA). WEIGHTED GENE CO-EXPRESSION NETWORK ANALYSIS (WGCNA) WAS USED TO IDENTIFY MODULES RELATED TO DEFINING PHYSIOLOGIC CHARACTERISTICS OF HPS. ONLY 12 OUT OF THE 20 LIVER BIOPSIES (7 HPS AND 5 CONTROLS) HAD SUFFICIENT QUALITY TO BE ANALYZED. NONE OF THE 802,688 DNA PROBES ANALYZED IN THE CASE CONTROL COMPARISON ACHIEVED A SIGNIFICANT FALSE DISCOVERY RATE (FDR). WGCNA IDENTIFIED 5 CO-METHYLATED GENE-MODULES ASSOCIATED TO HPS MARKERS, MAINLY RELATED TO NERVOUS AND NEUROENDOCRINE SYSTEM, APOPTOTIC PROCESSES, GUT BACTERIAL TRANSLOCATION, ANGIOGENESIS AND VASCULAR REMODELING ONTOLOGIES. TO CONCLUDE, HPS IS ASSOCIATED WITH NERVOUS/NEUROENDOCRINE SYSTEM AND VASCULAR REMODELING RELATED LIVER EPIGENETIC CHANGES.	2021	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
13 2643  34 EPIGENOMIC ASSOCIATION ANALYSIS IDENTIFIES SMOKING-RELATED DNA METHYLATION SITES IN AFRICAN AMERICANS. CIGARETTE SMOKING IS AN ENVIRONMENTAL RISK FACTOR FOR MANY CHRONIC DISEASES, AND DISEASE RISK CAN OFTEN BE MANAGED BY SMOKING CONTROL. SMOKING CAN INDUCE CELLULAR AND MOLECULAR CHANGES, INCLUDING EPIGENETIC MODIFICATION, BUT THE SHORT- AND LONG-TERM EPIGENETIC MODIFICATIONS CAUSED BY CIGARETTE SMOKING AT THE GENE LEVEL HAVE NOT BEEN WELL UNDERSTOOD. RECENT STUDIES HAVE IDENTIFIED SMOKING-RELATED DNA METHYLATION (DNAM) SITES IN CAUCASIANS. TO DETERMINE WHETHER THE SAME DNAM SITES ASSOCIATE WITH SMOKING IN AFRICAN AMERICANS, AND TO IDENTIFY NOVEL SMOKING-RELATED DNAM SITES, WE CONDUCTED A METHYLOME-WIDE ASSOCIATION STUDY OF CIGARETTE SMOKING USING A DISCOVERY SAMPLE OF 972 AFRICAN AMERICANS, AND A REPLICATION SAMPLE OF 239 AFRICAN AMERICANS WITH TWO ARRAY-BASED METHODS. AMONG 15 DNAM SITES SIGNIFICANTLY ASSOCIATED WITH SMOKING AFTER CORRECTION FOR MULTIPLE TESTING IN OUR DISCOVERY SAMPLE, 5 DNAM SITES ARE REPLICATED IN AN INDEPENDENT COHORT, AND 14 SITES IN THE REPLICATION SAMPLE HAVE EFFECTS IN THE SAME DIRECTION AS IN THE DISCOVERY SAMPLE. THE TOP TWO SMOKING-RELATED DNAM SITES IN F2RL3 (FACTOR II RECEPTOR-LIKE 3) AND GPR15 (G-PROTEIN-COUPLED RECEPTOR 15) OBSERVED IN AFRICAN AMERICANS ARE CONSISTENT WITH PREVIOUS FINDINGS IN CAUCASIANS. THE ASSOCIATIONS BETWEEN THE REPLICATED DNAM SITES AND SMOKING REMAIN SIGNIFICANT AFTER ADJUSTING FOR GENETIC BACKGROUND. DESPITE THE DISTINCT GENETIC BACKGROUND BETWEEN AFRICAN AMERICANS AND CAUCASIANS, THE DNAM FROM THE TWO ETHNIC GROUPS SHARES COMMON ASSOCIATIONS WITH CIGARETTE SMOKING, WHICH SUGGESTS A COMMON MOLECULAR MECHANISM OF EPIGENETIC MODIFICATION INFLUENCED BY ENVIRONMENTAL EXPOSURE.	2013	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
14  816  36 CHARACTERISATION OF AN INFLAMMATION-RELATED EPIGENETIC SCORE AND ITS ASSOCIATION WITH COGNITIVE ABILITY. BACKGROUND: CHRONIC SYSTEMIC INFLAMMATION HAS BEEN ASSOCIATED WITH INCIDENT DEMENTIA, BUT ITS ASSOCIATION WITH AGE-RELATED COGNITIVE DECLINE IS LESS CLEAR. THE ACUTE RESPONSES OF MANY INFLAMMATORY BIOMARKERS MEAN THEY MAY PROVIDE AN UNRELIABLE PICTURE OF THE CHRONICITY OF INFLAMMATION. RECENTLY, A LARGE-SCALE EPIGENOME-WIDE ASSOCIATION STUDY IDENTIFIED DNA METHYLATION CORRELATES OF C-REACTIVE PROTEIN (CRP)-A WIDELY USED ACUTE-PHASE INFLAMMATORY BIOMARKER. DNA METHYLATION IS THOUGHT TO BE RELATIVELY STABLE IN THE SHORT TERM, MARKING IT AS A POTENTIALLY USEFUL SIGNATURE OF EXPOSURE. METHODS: WE UTILISE A DNA METHYLATION-BASED SCORE FOR CRP AND INVESTIGATE ITS TRAJECTORIES WITH AGE, AND ASSOCIATIONS WITH COGNITIVE ABILITY IN COMPARISON WITH SERUM CRP AND A GENETIC CRP SCORE IN A LONGITUDINAL STUDY OF OLDER ADULTS (N = 889) AND A LARGE, CROSS-SECTIONAL COHORT (N = 7028). RESULTS: WE IDENTIFIED NO HOMOGENEOUS TRAJECTORIES OF SERUM CRP WITH AGE ACROSS THE COHORTS, WHEREAS THE EPIGENETIC CRP SCORE WAS CONSISTENTLY FOUND TO INCREASE WITH AGE (STANDARDISED BETA = 0.07 AND 0.01) AND TO DO SO MORE RAPIDLY IN MALES COMPARED TO FEMALES. ADDITIONALLY, THE EPIGENETIC CRP SCORE HAD HIGHER TEST-RETEST RELIABILITY COMPARED TO SERUM CRP, INDICATING ITS ENHANCED TEMPORAL STABILITY. HIGHER SERUM CRP WAS NOT FOUND TO BE ASSOCIATED WITH POORER COGNITIVE ABILITY (STANDARDISED BETA = - 0.08 AND - 0.05); HOWEVER, A CONSISTENT NEGATIVE ASSOCIATION WAS IDENTIFIED BETWEEN COGNITIVE ABILITY AND THE EPIGENETIC CRP SCORE IN BOTH COHORTS (STANDARDISED BETA = - 0.15 AND - 0.08). CONCLUSIONS: AN EPIGENETIC PROXY OF CRP MAY PROVIDE A MORE RELIABLE SIGNATURE OF CHRONIC INFLAMMATION, ALLOWING FOR MORE ACCURATE STRATIFICATION OF INDIVIDUALS, AND THUS CLEARER INFERENCE OF ASSOCIATIONS WITH INCIDENT HEALTH OUTCOMES.	2020	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
15 2411  34 EPIGENETIC SCORES FOR THE CIRCULATING PROTEOME AS TOOLS FOR DISEASE PREDICTION. PROTEIN BIOMARKERS HAVE BEEN IDENTIFIED ACROSS MANY AGE-RELATED MORBIDITIES. HOWEVER, CHARACTERISING EPIGENETIC INFLUENCES COULD FURTHER INFORM DISEASE PREDICTIONS. HERE, WE LEVERAGE EPIGENOME-WIDE DATA TO STUDY LINKS BETWEEN THE DNA METHYLATION (DNAM) SIGNATURES OF THE CIRCULATING PROTEOME AND INCIDENT DISEASES. USING DATA FROM FOUR COHORTS, WE TRAINED AND TESTED EPIGENETIC SCORES (EPISCORES) FOR 953 PLASMA PROTEINS, IDENTIFYING 109 SCORES THAT EXPLAINED BETWEEN 1% AND 58% OF THE VARIANCE IN PROTEIN LEVELS AFTER ADJUSTING FOR KNOWN PROTEIN QUANTITATIVE TRAIT LOCI (PQTL) GENETIC EFFECTS. BY PROJECTING THESE EPISCORES INTO AN INDEPENDENT SAMPLE (GENERATION SCOTLAND; N = 9537) AND RELATING THEM TO INCIDENT MORBIDITIES OVER A FOLLOW-UP OF 14 YEARS, WE UNCOVERED 137 EPISCORE-DISEASE ASSOCIATIONS. THESE ASSOCIATIONS WERE LARGELY INDEPENDENT OF IMMUNE CELL PROPORTIONS, COMMON LIFESTYLE AND HEALTH FACTORS, AND BIOLOGICAL AGING. NOTABLY, WE FOUND THAT OUR DIABETES-ASSOCIATED EPISCORES HIGHLIGHTED PREVIOUS TOP BIOMARKER ASSOCIATIONS FROM PROTEOME-WIDE ASSESSMENTS OF DIABETES. THESE EPISCORES FOR PROTEIN LEVELS CAN THEREFORE BE A VALUABLE RESOURCE FOR DISEASE PREDICTION AND RISK STRATIFICATION.	2022	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
16 1537  37 DNA METHYLATION IN ADOLESCENTS WITH ANXIETY DISORDER: A LONGITUDINAL STUDY. ANXIETY DISORDERS (AD) TYPICALLY MANIFEST IN CHILDREN AND ADOLESCENTS AND MIGHT PERSIST INTO ADULTHOOD. HOWEVER, THERE ARE STILL FEW DATA CONCERNING EPIGENETIC MECHANISMS ASSOCIATED WITH ONSET, PERSISTENCE OR REMISSION OF AD OVER TIME. WE INVESTIGATED A COHORT OF ADOLESCENTS AND YOUNG ADULTS AT BASELINE (AGE; 13.19 +/- 2.38) AND AFTER 5 YEARS AND CLASSIFIED THEM ACCORDING TO THE AD DIAGNOSIS AND THEIR LONGITUDINAL TRAJECTORIES INTO 4 GROUPS: (1) TYPICALLY DEVELOPING COMPARISONS (TDC; CONTROL GROUP, N = 14); (2) INCIDENT (AD IN THE SECOND EVALUATION ONLY, N = 11); (3) PERSISTENT (AD IN BOTH EVALUATIONS, N = 14) AND (4) REMITTENT (AD IN THE FIRST EVALUATION ONLY, N = 8). DNA METHYLATION WAS EVALUATED WITH THE INFINIUM HUMANMETHYLATION450 BEADCHIP FROM SALIVA SAMPLES COLLECTED AT BOTH EVALUATIONS. GENE SET ENRICHMENT ANALYSIS WAS APPLIED TO CONSIDER BIOLOGICAL PATHWAYS. WE FOUND DECREASED DNA METHYLATION IN TDC GROUP WHILE THE CHRONIC CASES OF AD PRESENTED HYPERMETHYLATION IN CENTRAL NERVOUS SYSTEM DEVELOPMENT PATHWAYS. MOREOVER, WE SHOWED THAT THIS PERSISTENT GROUP ALSO PRESENTED HYPERMETHYLATION WHILE THE OTHER THREE GROUPS WERE ASSOCIATED WITH HYPOMETHYLATION IN NERVOUS SYSTEM DEVELOPMENT PATHWAY. INCIDENCE AND REMISSION GROUPS WERE ASSOCIATED WITH INCREASED AND DECREASED METHYLATION IN NEURON DEVELOPMENT PATHWAYS, RESPECTIVELY. LARGER STUDIES ARE LIKELY TO DETECT SPECIFIC GENES RELEVANT TO AD.	2018	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
17 2418  33 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 2633  48 EPIGENOME-WIDE DNA METHYLATION PATTERNS ASSOCIATED WITH FATIGUE IN PRIMARY SJOGREN'S SYNDROME. OBJECTIVE: CHRONIC FATIGUE IS A COMMON, DISABLING AND POORLY UNDERSTOOD PHENOMENON. RECENT STUDIES INDICATE THAT EPIGENETIC MECHANISMS MAY BE INVOLVED IN THE EXPRESSION OF FATIGUE, A PROMINENT FEATURE OF PRIMARY SS (PSS). THE AIM OF THIS STUDY WAS TO INVESTIGATE WHETHER DNA METHYLATION PROFILES OF WHOLE BLOOD ARE ASSOCIATED WITH FATIGUE IN PATIENTS WITH PSS. METHODS: FORTY-EIGHT PSS PATIENTS WITH HIGH (N = 24) OR LOW (N = 24) FATIGUE AS MEASURED BY A VISUAL ANALOGUE SCALE WERE INCLUDED. GENOME-WIDE DNA METHYLATION WAS INVESTIGATED USING THE ILLUMINA HUMANMETHYLATION450 BEADCHIP ARRAY. AFTER QUALITY CONTROL, A TOTAL OF 383 358 CYTOSINE-PHOSPHATE-GUANINE (CPG) SITES REMAINED FOR FURTHER ANALYSIS. AGE, SEX AND DIFFERENTIAL CELL COUNT ESTIMATES WERE INCLUDED AS COVARIATES IN THE ASSOCIATION MODEL. A FALSE DISCOVERY RATE-CORRECTED P < 0.05 WAS CONSIDERED SIGNIFICANT, AND A CUT-OFF OF 3% AVERAGE DIFFERENCE IN METHYLATION LEVELS BETWEEN HIGH- AND LOW-FATIGUE PATIENTS WAS APPLIED. RESULTS: A TOTAL OF 251 DIFFERENTIALLY METHYLATED CPG SITES WERE ASSOCIATED WITH FATIGUE. THE CPG SITE WITH THE MOST PRONOUNCED HYPOMETHYLATION IN PSS HIGH FATIGUE ANNOTATED TO THE SBF2-ANTISENSE RNA1 GENE. THE MOST DISTINCT HYPERMETHYLATION WAS OBSERVED AT A CPG SITE ANNOTATED TO THE LYMPHOTOXIN ALPHA GENE. FUNCTIONAL PATHWAY ANALYSIS OF GENES WITH DIFFERENTLY METHYLATED CPG SITES IN SUBJECTS WITH HIGH VS LOW FATIGUE REVEALED ENRICHMENT IN SEVERAL PATHWAYS ASSOCIATED WITH INNATE AND ADAPTIVE IMMUNITY. CONCLUSION: SOME GENES INVOLVED IN REGULATION OF THE IMMUNE SYSTEM AND IN INFLAMMATION ARE DIFFERENTLY METHYLATED IN PSS PATIENTS WITH HIGH VS LOW FATIGUE. THESE FINDINGS POINT TO FUNCTIONAL NETWORKS THAT MAY UNDERLIE FATIGUE. EPIGENETIC CHANGES COULD CONSTITUTE A FATIGUE-REGULATING MECHANISM IN PSS.	2016	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
19 4256  43 METHYLOMIC MARKERS OF PERSISTENT CHILDHOOD ASTHMA: A LONGITUDINAL STUDY OF ASTHMA-DISCORDANT MONOZYGOTIC TWINS. BACKGROUND: ASTHMA IS THE MOST COMMON CHRONIC INFLAMMATORY DISORDER IN CHILDREN. THE AETIOLOGY OF ASTHMA PATHOLOGY IS COMPLEX AND HIGHLY HETEROGENEOUS, INVOLVING THE INTERPLAY BETWEEN GENETIC AND ENVIRONMENTAL RISK FACTORS THAT IS HYPOTHESIZED TO INVOLVE EPIGENETIC PROCESSES. OUR AIM WAS TO EXPLORE WHETHER METHYLOMIC VARIATION IN EARLY CHILDHOOD IS ASSOCIATED WITH DISCORDANCE FOR ASTHMA SYMPTOMS WITHIN MONOZYGOTIC (MZ) TWIN PAIRS RECRUITED FROM THE ENVIRONMENTAL RISK (E-RISK) LONGITUDINAL TWIN STUDY. WE ALSO AIMED TO IDENTIFY DIFFERENCES IN DNA METHYLATION THAT ARE ASSOCIATED WITH ASTHMA THAT DEVELOPS IN CHILDHOOD AND PERSISTS INTO EARLY ADULTHOOD AS THESE MAY REPRESENT USEFUL PROGNOSTIC BIOMARKERS. RESULTS: WE EXAMINED GENOME-WIDE PATTERNS OF DNA METHYLATION IN BUCCAL CELL SAMPLES COLLECTED FROM 37 MZ TWIN PAIRS DISCORDANT FOR ASTHMA AT AGE 10. DNA METHYLATION AT INDIVIDUAL CPG SITES DEMONSTRATED SIGNIFICANT VARIABILITY WITHIN DISCORDANT MZ TWIN PAIRS WITH THE TOP-RANKED NOMINALLY SIGNIFICANT DIFFERENTIALLY METHYLATED POSITION (DMP) LOCATED IN THE HGSNAT GENE. WE STRATIFIED OUR ANALYSIS BY ASSESSING DNA METHYLATION DIFFERENCES IN A SUB-GROUP OF MZ TWIN PAIRS WHO REMAINED PERSISTENTLY DISCORDANT FOR ASTHMA AT AGE 18. THE TOP-RANKED NOMINALLY SIGNIFICANT DMP ASSOCIATED WITH PERSISTING ASTHMA IS LOCATED IN THE VICINITY OF THE HLX GENE, WHICH HAS BEEN PREVIOUSLY IMPLICATED IN CHILDHOOD ASTHMA. CONCLUSIONS: WE IDENTIFIED DNA METHYLATION DIFFERENCES ASSOCIATED WITH CHILDHOOD ASTHMA IN PERIPHERAL DNA SAMPLES FROM DISCORDANT MZ TWIN PAIRS. OUR DATA SUGGEST THAT DIFFERENCES IN DNA METHYLATION ASSOCIATED WITH CHILDHOOD ASTHMA WHICH PERSISTS INTO EARLY ADULTHOOD ARE DISTINCT FROM THOSE ASSOCIATED WITH ASTHMA WHICH REMITS.	2015	
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
20 1343  46 DETECTING CORD BLOOD CELL TYPE-SPECIFIC EPIGENETIC ASSOCIATIONS WITH GESTATIONAL DIABETES MELLITUS AND EARLY CHILDHOOD GROWTH. BACKGROUND: EPIGENOME-WIDE ASSOCIATION STUDIES (EWAS) HAVE PROVIDED OPPORTUNITIES TO UNDERSTAND THE ROLE OF EPIGENETIC MECHANISMS IN DEVELOPMENT AND PATHOPHYSIOLOGY OF MANY CHRONIC DISEASES. HOWEVER, AN IMPORTANT LIMITATION OF CONVENTIONAL EWAS IS THAT PROFILES OF EPIGENETIC VARIABILITY ARE OFTEN OBTAINED IN SAMPLES OF MIXED CELL TYPES. HERE, WE AIM TO ASSESS WHETHER CHANGES IN CORD BLOOD DNA METHYLATION (DNAM) ASSOCIATED WITH GESTATIONAL DIABETES MELLITUS (GDM) EXPOSURE AND EARLY CHILDHOOD GROWTH MARKERS OCCUR IN A CELL TYPE-SPECIFIC MANNER. RESULTS: WE ANALYZED 275 CORD BLOOD SAMPLES COLLECTED AT DELIVERY FROM A PROSPECTIVE PRE-BIRTH COHORT WITH GENOME-WIDE DNAM PROFILED BY THE ILLUMINA METHYLATIONEPIC ARRAY. WE ESTIMATED PROPORTIONS OF SEVEN COMMON CELL TYPES IN EACH SAMPLE USING A CORD BLOOD-SPECIFIC DNAM REFERENCE PANEL. LEVERAGING A RECENTLY DEVELOPED APPROACH NAMED CELLDMC, WE PERFORMED CELL TYPE-SPECIFIC EWAS TO IDENTIFY CPG LOCI SIGNIFICANTLY ASSOCIATED WITH GDM, OR 3-YEAR-OLD BODY MASS INDEX (BMI) Z-SCORE. A TOTAL OF 1410 CPG LOCI DISPLAYED SIGNIFICANT CELL TYPE-SPECIFIC DIFFERENCES IN METHYLATION LEVEL BETWEEN 23 GDM CASES AND 252 CONTROLS WITH A FALSE DISCOVERY RATE < 0.05. GENE ONTOLOGY ENRICHMENT ANALYSIS INDICATED THAT LDL TRANSPORTATION EMERGED FROM CPG SPECIFICALLY IDENTIFIED FROM B-CELLS DNAM ANALYSES AND THE MITOGEN-ACTIVATED PROTEIN KINASE PATHWAY EMERGED FROM CPG SPECIFICALLY IDENTIFIED FROM NATURAL KILLER CELLS DNAM ANALYSES. IN ADDITION, WE IDENTIFIED FOUR AND SIX LOCI ASSOCIATED WITH 3-YEAR-OLD BMI Z-SCORE THAT WERE SPECIFIC TO CD8+ T-CELLS AND MONOCYTES, RESPECTIVELY. BY PERFORMING GENOME-WIDE PERMUTATION TESTS, WE VALIDATED THAT MOST OF OUR DETECTED SIGNALS HAD LOW FALSE POSITIVE RATES. CONCLUSION: COMPARED TO CONVENTIONAL EWAS ADJUSTING FOR THE EFFECTS OF CELL TYPE HETEROGENEITY, THE PROPOSED APPROACH BASED ON CELL TYPE-SPECIFIC EWAS COULD PROVIDE ADDITIONAL BIOLOGICALLY MEANINGFUL ASSOCIATIONS BETWEEN CPG METHYLATION, PRENATAL MATERNAL GDM OR 3-YEAR-OLD BMI. WITH CAREFUL VALIDATION, THESE FINDINGS MAY PROVIDE NEW INSIGHTS INTO THE PATHOGENESIS, PROGRAMMING, AND CONSEQUENCES OF RELATED CHILDHOOD METABOLIC DYSREGULATION. THEREFORE, WE PROPOSE THAT CELL TYPE-SPECIFIC ANALYSES ARE WORTH CAUTIOUS EXPLORATIONS.	2021