1 1554 162 DNA METHYLATION LEVELS OF RELN PROMOTER REGION IN ULTRA-HIGH RISK, FIRST EPISODE AND CHRONIC SCHIZOPHRENIA COHORTS OF SCHIZOPHRENIA. THE ESSENTIAL ROLE OF THE REELIN GENE (RELN) DURING BRAIN DEVELOPMENT MAKES IT A PROMINENT CANDIDATE IN HUMAN EPIGENETIC STUDIES OF SCHIZOPHRENIA. PREVIOUS LITERATURE HAS REPORTED DIFFERING LEVELS OF DNA METHYLATION (DNAM) IN PATIENTS WITH PSYCHOSIS. THEREFORE, THIS STUDY AIMED TO (1) EXAMINE AND COMPARE RELN DNAM LEVELS IN SUBJECTS AT DIFFERENT STAGES OF PSYCHOSIS CROSS-SECTIONALLY, (2) ANALYSE THE EFFECT OF ANTIPSYCHOTICS (AP) ON DNAM, AND (3) EVALUATE THE EFFECTIVENESS AND APPLICABILITY OF RELN PROMOTER DNAM AS A POSSIBLE BIOLOGICAL-BASED MARKER FOR SYMPTOM SEVERITY IN PSYCHOSIS.. THE STUDY COHORT CONSISTED OF 56 HEALTHY CONTROLS, 87 ULTRA-HIGH RISK (UHR) INDIVIDUALS, 26 FIRST-EPISODE (FE) PSYCHOSIS INDIVIDUALS AND 30 CHRONIC SCHIZOPHRENIA (CS) INDIVIDUALS. THE POSITIVE AND NEGATIVE SYNDROME SCALE (PANSS) WAS USED TO ASSESS SCHIZOPHRENIA SEVERITY. AFTER PYROSEQUENCING SELECTED CPG SITES OF PERIPHERAL BLOOD, THE AVERAGE MEAN DNAM LEVELS WERE COMPARED AMONGST THE 4 SUBGROUPS. OUR RESULTS SHOWED DIFFERING LEVELS OF DNAM, WITH UHR HAVING THE LOWEST (7.72 +/- 0.19) WHILE THE CS HAD THE HIGHEST LEVELS (HC: 8.78 +/- 0.35; FE: 7.75 +/- 0.37; CS: 8.82 +/- 0.48). SIGNIFICANTLY HIGHER AVERAGE MEAN DNAM LEVELS WERE FOUND IN CS SUBJECTS ON AP (9.12 +/- 0.61) COMPARED TO UHR WITHOUT MEDICATION (UHR(-)) (7.39 +/- 0.18). A SIGNIFICANT ASSOCIATION WAS ALSO OBSERVED BETWEEN THE AVERAGE MEAN DNAM OF FE AND PANSS NEGATIVE SYMPTOM FACTOR (R(2) = 0.237, SS = -0.401, *P = 0.033). IN CONCLUSION, OUR FINDINGS SUGGESTED DIFFERENT LEVELS OF DNAM FOR SUBJECTS AT DIFFERENT STAGES OF PSYCHOSIS. THOSE SUBJECTS THAT TOOK AP HAVE DIFFERENT DNAM LEVELS. THERE WERE SIGNIFICANT ASSOCIATIONS BETWEEN FE DNAM AND NEGATIVE PANSS SCORES. WITH MORE FUTURE EXPERIMENTS AND ON LARGER COHORTS, THERE MAY BE POTENTIAL USE OF DNAM OF THE RELN GENE AS ONE OF THE GENES FOR THE BIOLOGICAL-BASED MARKER FOR SYMPTOM SEVERITY IN PSYCHOSIS. 2022 2 2921 43 GENE-SPECIFIC DIFFERENTIAL DNA METHYLATION AND CHRONIC ARSENIC EXPOSURE IN AN EPIGENOME-WIDE ASSOCIATION STUDY OF ADULTS IN BANGLADESH. BACKGROUND: INORGANIC ARSENIC IS ONE OF THE MOST COMMON NATURALLY OCCURRING CONTAMINANTS FOUND IN THE ENVIRONMENT. ARSENIC IS ASSOCIATED WITH A NUMBER OF HEALTH OUTCOMES, WITH EPIGENETIC MODIFICATION SUGGESTED AS A POTENTIAL MECHANISM OF TOXICITY. OBJECTIVE: AMONG A SAMPLE OF 400 ADULT PARTICIPANTS, WE EVALUATED THE ASSOCIATION BETWEEN ARSENIC EXPOSURE, AS MEASURED BY BLOOD AND URINARY TOTAL ARSENIC CONCENTRATIONS, AND EPIGENOME-WIDE WHITE BLOOD CELL DNA METHYLATION. METHODS: WE USED LINEAR REGRESSION MODELS TO EXAMINE THE ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND METHYLATION AT EACH CPG SITE, ADJUSTED FOR SEX, AGE, AND BATCH. DIFFERENTIALLY METHYLATED LOCI WERE SUBSEQUENTLY EXAMINED IN RELATION TO CORRESPONDING GENE EXPRESSION FOR FUNCTIONAL EVIDENCE OF GENE REGULATION. RESULTS: IN ADJUSTED ANALYSES, WE OBSERVED FOUR DIFFERENTIALLY METHYLATED CPG SITES WITH URINARY TOTAL ARSENIC CONCENTRATION AND THREE DIFFERENTIALLY METHYLATED CPG SITES WITH BLOOD ARSENIC CONCENTRATION, BASED ON THE BONFERRONI-CORRECTED SIGNIFICANCE THRESHOLD OF P < 1 X 10(-7). METHYLATION OF PLA2G2C (PROBE CG04605617) WAS THE MOST SIGNIFICANTLY ASSOCIATED LOCUS IN RELATION TO BOTH URINARY (P = 3.40 X 10(-11)) AND BLOOD ARSENIC CONCENTRATIONS (P = 1.48 X 10(-11)). THREE ADDITIONAL NOVEL METHYLATION LOCI-SQSTM1 (CG01225779), SLC4A4 (CG06121226), AND IGH (CG13651690)--WERE ALSO SIGNIFICANTLY ASSOCIATED WITH ARSENIC EXPOSURE. FURTHER, THERE WAS EVIDENCE OF METHYLATION-RELATED GENE REGULATION BASED ON GENE EXPRESSION FOR A SUBSET OF DIFFERENTIALLY METHYLATED LOCI. CONCLUSIONS: WE OBSERVED SIGNIFICANT ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND GENE-SPECIFIC DIFFERENTIAL WHITE BLOOD CELL DNA METHYLATION, SUGGESTING THAT EPIGENETIC MODIFICATIONS MAY BE AN IMPORTANT PATHWAY UNDERLYING ARSENIC TOXICITY. THE SPECIFIC DIFFERENTIALLY METHYLATED LOCI IDENTIFIED MAY INFORM POTENTIAL PATHWAYS FOR FUTURE INTERVENTIONS. 2015 3 1529 33 DNA METHYLATION CHANGES IN WHOLE BLOOD AND CD16+ NEUTROPHILS IN RESPONSE TO CHRONIC FOLIC ACID SUPPLEMENTATION IN WOMEN OF CHILDBEARING AGE. FOLATE, A WATER-SOLUBLE VITAMIN, IS A KEY SOURCE OF ONE-CARBON GROUPS FOR DNA METHYLATION, BUT STUDIES OF THE DNA METHYLATION RESPONSE TO SUPPLEMENTAL FOLIC ACID YIELD INCONSISTENT RESULTS. THESE STUDIES ARE COMMONLY CONDUCTED USING WHOLE BLOOD, WHICH CONTAINS A MIXED POPULATION OF WHITE BLOOD CELLS THAT HAVE BEEN SHOWN TO CONFOUND RESULTS. THE OBJECTIVE OF THIS STUDY WAS TO DETERMINE IF CD16+ NEUTROPHILS MAY PROVIDE MORE SPECIFIC DATA THAN WHOLE BLOOD FOR IDENTIFYING DNA METHYLATION RESPONSE TO CHRONIC FOLIC ACID SUPPLEMENTATION. THE STUDY WAS PERFORMED IN NORMAL WEIGHT (BMI 18.5 - 24.9 KG/M2) WOMEN (18 - 35 Y; N = 12), WITH BLOOD SAMPLES TAKEN BEFORE AND AFTER 8 WEEKS OF FOLIC ACID SUPPLEMENTATION AT 800 MUG/DAY. DNA METHYLATION PATTERNS FROM WHOLE BLOOD AND ISOLATED CD16+ NEUTROPHILS WERE MEASURED ACROSS >485,000 CPG SITES THROUGHOUT THE GENOME USING THE INFINIUM HUMANMETHYLATION450 BEADCHIP. OVER THE COURSE OF THE 8-WEEK SUPPLEMENTATION, 6746 AND 7513 CPG SITES CHANGED (P < 0.05) IN WHOLE BLOOD AND CD16+ NEUTROPHILS, RESPECTIVELY. DNA METHYLATION DECREASED IN 68.4% (WHOLE BLOOD) AND 71.8% (CD16+ NEUTROPHILS) OF THESE SITES. THERE WERE ONLY 182 CPG SITES THAT CHANGED IN BOTH THE WHOLE BLOOD AND CD16+ NEUTROPHILS, 139 OF WHICH CHANGED IN THE SAME DIRECTION. THESE RESULTS SUGGEST THAT THE GENOME-WIDE DNA METHYLATION RESPONSE TO CHRONIC FOLIC ACID SUPPLEMENTATION IS DIFFERENT BETWEEN WHOLE BLOOD AND CD16+ NEUTROPHILS AND THAT A SINGLE WHITE BLOOD CELL TYPE MAY FUNCTION AS A MORE SPECIFIC EPIGENETIC REPORTER OF FOLATE STATUS THAN WHOLE BLOOD. 2017 4 1849 32 EIGHT WEEKS OF PHYSICAL TRAINING DECREASES 2 YEARS OF DNA METHYLATION AGE OF SEDENTARY WOMEN. PURPOSE: THE ACCELERATION OF EPIGENETIC AGE IS A PREDICTOR OF MORTALITY AND CONTRIBUTES TO THE INCREASE IN CHRONIC DISEASES. ADHERENCE TO A HEALTHY LIFESTYLE IS A STRATEGY TO REDUCE EPIGENETIC AGE. THE PRESENT STUDY AIMED TO DETERMINE WHETHER EIGHT WEEKS OF COMBINED (AEROBIC AND STRENGTH) TRAINING (CT) CAN INFLUENCE THE EPIGENETIC AGE OF WOMEN BETWEEN 50 AND 70 YEARS OLD AND THE DIFFERENCES IN SITES AND METHYLATED REGIONS. METHODS: EIGHTEEN WOMEN (AAR(LOW): LOWER AGE ACCELERATION RESIDUAL, N = 10; AAR(HIGH): HIGHER AGE ACCELERATION RESIDUAL, N = 8) PARTICIPATED IN A COMBINED EXERCISE TRAINING PROGRAM (60 MINUTES, 3X A WEEK) FOR EIGHT WEEKS. DNA WAS EXTRACTED FROM WHOLE BLOOD USING THE SALTING OUT TECHNIQUE. DNA METHYLATION WAS PERFORMED USING THE ARRAY TECHNIQUE (ILLUMINA'S INFINIUM METHYLATION BEADCHIP 850K). WE USED THE DNA METHYLATION AGE CALCULATOR PLATFORM TO CALCULATE THE BIOLOGICAL EPIGENETIC AGE. TWO-WAY ANOVA FOLLOWED BY FISHER LSD POSTHOC WAS APPLIED, ADOPTING P < .05. RESULTS: AFTER EIGHT WEEKS OF CT, THERE WERE NO CHANGES TO THE EPIGENETIC AGE ACCELERATION FOR THE AAR(LOW) GROUP (PRE: -2.3 +/- 3.2 TO POST: -2.3 +/- 3.6). HOWEVER, THE AAR(HIGH) GROUP SIGNIFICANTLY DECREASED THE AGE ACCELERATION (PRE: 3.6 +/- 2.6 TO POST: 2.2 +/- 2.7) (GROUP EFFECT, P = .01; TIME EFFECT, P = .31; GROUP VS. TIME EFFECT, P = .005). CONCLUSION: CT FOR EIGHT WEEKS BENEFITS THE EPIGENETIC CLOCK OF WOMEN WITH THE MOST ACCELERATED AGE. 2023 5 3133 39 GLOBAL DNA HYPOMETHYLATION AND ITS CORRELATION TO THE BETAINE LEVEL IN PERIPHERAL BLOOD OF PATIENTS WITH SCHIZOPHRENIA. ACCUMULATING EVIDENCE SUGGESTS THAT ABERRANT EPIGENETIC REGULATION IS INVOLVED IN THE PATHOPHYSIOLOGY OF MAJOR PSYCHIATRIC DISORDERS SUCH AS SCHIZOPHRENIA (SZ) AND BIPOLAR DISORDER (BD). WE PREVIOUSLY SHOWED THAT THE PLASMA LEVEL OF BETAINE (N,N,N-TRIMETHYLGLYCINE), A METHYL-GROUP DONOR, WAS SIGNIFICANTLY DECREASED IN PATIENTS WITH FIRST EPISODE SCHIZOPHRENIA (FESZ). IN THIS STUDY, WE IDENTIFIED DECREASE OF GLOBAL DNA METHYLATION LEVEL IN FESZ (N = 24 PATIENTS VS N = 42 CONTROLS), AND FOUND THAT GLOBAL DNA METHYLATION LEVEL WAS INVERSELY CORRELATED WITH SCORES ON THE GLOBAL ASSESSMENT OF FUNCTIONING (GAF) SCALE, AND POSITIVELY CORRELATED WITH PLASMA BETAINE LEVEL. NOTABLY, CORRELATIONS BETWEEN LEVELS OF BETAINE AND ITS METABOLITES (N,N-DIMETHYLGLYCINE AND SARCOSINE, N-METHYLGLYCINE) WERE LOWER OR LOST IN FESZ PLASMA, BUT REMAINED HIGH IN CONTROLS. WE FURTHER EXAMINED GLOBAL DNA METHYLATION LEVELS IN PATIENTS WITH CHRONIC SZ (N = 388) AND BD (N = 414) AS WELL AS CONTROLS (N = 430), AND CONFIRMED SIGNIFICANT HYPOMETHYLATION AND DECREASED BETAINE LEVEL IN SZ. WE ALSO FOUND THAT PATIENTS WITH BD TYPE I, BUT NOT THOSE WITH BD TYPE II, SHOWED SIGNIFICANT GLOBAL HYPOMETHYLATION. THESE RESULTS SUGGEST THAT GLOBAL HYPOMETHYLATION ASSOCIATED WITH DECREASED BETAINE LEVEL IN BLOOD CELLS IS COMMON TO SZ AND BD, AND MAY REFLECT COMMON PATHOPHYSIOLOGY SUCH AS PSYCHOTIC SYMPTOMS. 2020 6 6190 40 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 7 5273 42 PROMOTER METHYLATION AND BDNF AND DAT1 GENE EXPRESSION PROFILES IN PATIENTS WITH DRUG ADDICTION. BACKGROUND: DRUG ADDICTION IS A BRAIN DISORDER THAT HAS NEGATIVE CONSEQUENCES FOR INDIVIDUALS AND SOCIETY. ADDICTIONS ARE CHRONIC RELAPSING DISEASES OF THE BRAIN THAT ARE CAUSED BY DIRECT DRUG-INDUCED EFFECTS AND PERSEVERING NEUROADAPTATIONS AT THE EPIGENETIC, NEUROPEPTIDE AND NEUROTRANSMITTER LEVELS. BECAUSE THE DOPAMINERGIC SYSTEM HAS A SIGNIFICANT ROLE IN DRUG ABUSE, THE PURPOSE OF THIS STUDY WAS TO ANALYZE THE METHYLATION AND EXPRESSION PROFILE OF BRAIN-DERIVED NEUROTROPHIC FACTOR (BDNF) AND DOPAMINE TRANSPORTER (DAT1) GENES IN INDIVIDUALS WITH DRUG ADDICTION. MATERIALS AND METHODS: BDNF AND DAT1 PROMOTER METHYLATION WERE INVESTIGATED WITH A METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) TECHNIQUE IN BLOOD SAMPLES FROM 75 INDIVIDUALS WITH DRUG ADDICTION AND 65 HEALTHY CONTROLS. THE EXPRESSION LEVELS OF BDNF AND DAT1 WERE ASSESSED IN 12 MRNA SAMPLES FROM THE BLOOD OF PATIENTS AND COMPARED TO THE SAMPLES OF HEALTHY CONTROLS (N = 12) WITH REAL-TIME QUANTITATIVE REVERSE TRANSCRIPTION PCR. RESULTS: NO SIGNIFICANT DIFFERENCES WERE FOUND IN THE METHYLATION OF BDNF AND DAT1 BETWEEN PATIENTS AND CONTROLS, BUT THE RELATIVE LEVELS OF EXPRESSION OF BDNF AND DAT1 MRNA DIFFERED SIGNIFICANTLY IN THE PATIENTS COMPARED TO CONTROLS (P < 0.0001). CONCLUSION: THESE RESULTS SHOWED THAT THE METHYLATION STATUS OF THE BDNF AND DAT1 GENES HAD NO SIGNIFICANT FUNCTION IN THE PROCESSES OF DRUG ADDICTION. 2015 8 4024 41 LUNG ALLOGRAFT EPITHELIUM DNA METHYLATION AGE IS ASSOCIATED WITH GRAFT CHRONOLOGIC AGE AND PRIMARY GRAFT DYSFUNCTION. ADVANCED DONOR AGE IS A RISK FACTOR FOR POOR SURVIVAL FOLLOWING LUNG TRANSPLANTATION. HOWEVER, RECENT WORK IDENTIFYING EPIGENETIC DETERMINANTS OF AGING HAS SHOWN THAT BIOLOGIC AGE MAY NOT ALWAYS REFLECT CHRONOLOGIC AGE AND THAT STRESSORS CAN ACCELERATE BIOLOGIC AGING. WE HYPOTHESIZED THAT LUNG ALLOGRAFTS THAT EXPERIENCED PRIMARY GRAFT DYSFUNCTION (PGD), CHARACTERIZED BY POOR OXYGENATION IN THE FIRST THREE POST-TRANSPLANT DAYS, WOULD HAVE INCREASED BIOLOGIC AGE. WE CULTURED AIRWAY EPITHELIAL CELLS ISOLATED BY TRANSBRONCHIAL BRUSH AT 1-YEAR BRONCHOSCOPIES FROM 13 SUBJECTS WITH SEVERE PGD AND 15 CONTROLS MATCHED ON AGE AND TRANSPLANT INDICATION. WE MEASURED EPIGENETIC AGE USING THE HORVATH EPIGENETIC CLOCK. LINEAR MODELS WERE USED TO DETERMINE THE ASSOCIATION OF AIRWAY EPIGENETIC AGE WITH CHRONOLOGIC AGES AND PGD STATUS, ADJUSTED FOR RECIPIENT PGD RISK FACTORS. SURVIVAL MODELS ASSESSED THE ASSOCIATION WITH CHRONIC LUNG ALLOGRAFT DYSFUNCTION (CLAD) OR DEATH. DISTRIBUTIONS OF PROMOTER METHYLATION WITHIN PATHWAYS WERE COMPARED BETWEEN GROUPS. DNA METHYLTRANSFERASE (DNMT) ACTIVITY WAS QUANTIFIED IN AIRWAY EPITHELIAL CELLS UNDER HYPOXIC OR NORMOXIC CONDITIONS. AIRWAY EPIGENETIC AGE APPEARED YOUNGER BUT WAS STRONGLY ASSOCIATED WITH THE AGE OF THE ALLOGRAFT (SLOPE 0.38 PER YEAR, 95% CI 0.27-0.48). THERE WAS NO CORRELATION BETWEEN EPIGENETIC AGE AND RECIPIENT AGE (P = 0.96). EPIGENETIC AGE WAS 6.5 YEARS GREATER (95% CI 1.7-11.2) IN SUBJECTS WHO HAD EXPERIENCED PGD, AND THIS EFFECT REMAINED SIGNIFICANT AFTER ADJUSTING FOR DONOR AND RECIPIENT CHARACTERISTICS (P = 0.03). EPIGENETIC AGE WAS NOT ASSOCIATED WITH CLAD-FREE SURVIVAL RISK (P = 0.11). ANALYSIS OF DIFFERENTIAL METHYLATION OF PROMOTERS OF KEY BIOLOGIC PATHWAYS REVEALED HYPOMETHYLATION IN REGIONS RELATED TO HYPOXIA, INFLAMMATION, AND METABOLISM-ASSOCIATED PATHWAYS. ACCORDINGLY, AIRWAY EPITHELIAL CELLS CULTURED IN HYPOXIC CONDITIONS SHOWED SUPPRESSED DNMT ACTIVITY. WHILE AIRWAY METHYLATION AGE WAS PRIMARILY DETERMINED BY DONOR CHRONOLOGIC AGE, EARLY INJURY IN THE FORM OF PGD WAS ASSOCIATED WITH INCREASED ALLOGRAFT EPIGENETIC AGE. THESE DATA SHOW HOW PGD MIGHT SUPPRESS KEY PROMOTER METHYLATION RESULTING IN LONG-TERM IMPACTS ON THE ALLOGRAFT. 2021 9 1607 36 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 10 4242 33 METHYLATION STATUS OF ALU AND LINE-1 INTERSPERSED REPETITIVE SEQUENCES IN BEHCET'S DISEASE PATIENTS. BEHCET'S DISEASE (BD) IS A MULTISYSTEM CHRONIC INFLAMMATORY DISEASE. THE PATHOLOGY IS BELIEVED TO INVOLVE BOTH GENETIC SUSCEPTIBILITY AND ENVIRONMENTAL FACTORS. HYPOMETHYLATION LEADING TO ACTIVATION OF INTERSPERSED REPETITIVE SEQUENCES (IRSS) SUCH AS LINE-1 AND ALU CONTRIBUTES TO THE PATHOLOGIES OF AUTOIMMUNE DISEASES AND CANCER. HEREIN, THE EPIGENETIC CHANGES OF IRSS IN BD WERE EVALUATED USING COMBINED BISULFITE RESTRICTION ANALYSIS-INTERSPERSED REPETITIVE SEQUENCES (COBRA-IRS). DNA FROM NEUTROPHILS AND PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS) OF BD PATIENTS WITH OCULAR INVOLVEMENT THAT WERE IN ACTIVE OR INACTIVE STATES AND HEALTHY CONTROLS WERE USED TO ANALYZE LINE-1 AND ALU METHYLATION LEVELS. FOR ALU SEQUENCES, SIGNIFICANT DIFFERENCES WERE OBSERVED IN THE FREQUENCY OF (U)C(U)C ALLELES BETWEEN PBMCS OF PATIENTS AND CONTROLS (P = 0.03), AND BETWEEN INACTIVE PATIENTS AND CONTROLS (P = 0.03). FOR NEUTROPHILS, THE FREQUENCY OF (U)C(U)C WAS SIGNIFICANTLY HIGHER BETWEEN PATIENTS AND CONTROLS (P = 0.006) AND BETWEEN INACTIVE PATIENTS AND CONTROLS (P = 0.002). THE PARTIAL METHYLATION ((U)C(M)C + (M)C(U)C) FREQUENCIES OF ALU BETWEEN INACTIVE PATIENTS AND CONTROL SAMPLES ALSO DIFFERED (P = 0.02). NO STATISTICALLY SIGNIFICANT DIFFERENCES FOR LINE-1 WERE DETECTED. THUS, CHANGES IN THE METHYLATION LEVEL OF IRS ELEMENTS MIGHT CONTRIBUTE TO THE PATHOGENESIS OF BD. THE ROLE OF ALU TRANSCRIPTS IN BD SHOULD BE INVESTIGATED FURTHER. 2016 11 1962 45 EPIGENETIC AGING IS ASSOCIATED WITH CLINICAL AND EXPERIMENTAL PAIN IN COMMUNITY-DWELLING OLDER ADULTS. GERONTOLOGICAL RESEARCH REVEALS CONSIDERABLE INTERINDIVIDUAL VARIABILITY IN AGING PHENOTYPES, WHICH HAS MOTIVATED RESEARCH EFFORTS TO IDENTIFY "AGING BIOMARKERS." AGING BIOMARKERS ARE USED TO CALCULATE BIOLOGICAL AGE, WHICH ARE BETTER PREDICTORS OF DISEASE RISK AND RESIDUAL LIFESPAN WHEN COMPARED TO CHRONOLOGICAL AGE ALONE. EMERGING EVIDENCE USING THE EPIGENETIC CLOCK AS AN AGING BIOMARKER SUPPORTS HIGHLY RELIABLE INDIVIDUALIZED PREDICTIONS ABOUT FUTURE HEALTH. THIS STUDY AIMED TO DETERMINE WHETHER AN EPIGENETIC AGING BIOMARKER WAS ASSOCIATED WITH CHRONIC PAIN IN OLDER ADULTS (60-83 YEARS OLD). A SUBSET OF PARTICIPANTS (N = 29) IN THE NEUROMODULATORY EXAMINATION OF PAIN AND MOBILITY ACROSS THE LIFESPAN STUDY UNDERWENT A BLOOD DRAW, DEMOGRAPHIC, PSYCHOLOGICAL, COGNITIVE, AND PAIN ASSESSMENTS. WE ESTIMATED HORVATH'S EPIGENETIC CLOCK AND CALCULATED THE DIFFERENCE BETWEEN EPIGENETIC AGE AND CHRONOLOGICAL AGE THAT HAS BEEN PREVIOUSLY REPORTED TO PREDICT OVERALL MORTALITY RISK. OLDER INDIVIDUALS WITHOUT CHRONIC PAIN (N = 9) HAD SIGNIFICANTLY "YOUNGER" EPIGENETIC AGE COMPARED TO THOSE WITH CHRONIC PAIN (N = 20, P < 0.05). OLDER EPIGENETIC AGE WAS ASSOCIATED WITH GREATER PAIN DURING DAILY ACTIVITIES (R = 0.494, P = 0.010) AND ANATOMICAL PAIN SITES (R = 0.741, P < 0.001) BUT NOT PAIN FREQUENCY/DURATION. AN OLDER EPIGENETIC AGE WAS ALSO ASSOCIATED WITH HIGHER VIBRATORY DETECTION THRESHOLDS (R = 0.490, P = 0.021), HEAT PAIN THRESHOLDS (R = -0.478, P = 0.028), AND PRESSURE PAIN THRESHOLDS AT THE TRAPEZIUS (R = -0.571, P = 0.006) BUT NOT THERMAL DETECTION, PRESSURE PAIN AT THE QUADRICEPS OR PAIN INHIBITION (P'S > 0.05). EPIGENETIC AGING WAS ASSOCIATED WITH GREATER EMOTIONAL STABILITY (R = -0.461, P = 0.027), CONSCIENTIOUSNESS (R = -0.549, P = 0.007), AND LOWER EXTRAVERSION (R = 0.414, P = 0.049) BUT NOT DEPRESSION OR AFFECT (P'S > 0.05). EPIGENETIC AGING WAS ALSO ASSOCIATED WITH LOWER EPISODIC (R = -0.698, P = 0.001) AND WORKING MEMORY (R = -0.760, P < 0.001). OUR FINDINGS SUGGEST THAT CHRONIC PAIN IS ASSOCIATED WITH ACCELERATED EPIGENETIC AGING IN HEALTHY, COMMUNITY-DWELLING OLDER INDIVIDUALS, AND FUTURE STUDIES WITH LARGER SAMPLES ARE NEEDED TO CONFIRM OUR FINDINGS. AN AGING BIOMARKER SUCH AS THE EPIGENETIC CLOCK MAY HELP IDENTIFY PEOPLE WITH CHRONIC PAIN AT GREATER RISK OF FUNCTIONAL DECLINE AND POORER HEALTH OUTCOMES. 2019 12 659 35 BLOOD GLOBAL DNA METHYLATION IS DECREASED IN NON-SEVERE CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) PATIENTS. BACKGROUND: ALTERATIONS IN GLOBAL DNA METHYLATION HAVE BEEN ASSOCIATED WITH OXIDATIVE STRESS (OS). SINCE CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS CHARACTERIZED BY INCREASED OXIDATIVE STRESS WE AIMED TO EVALUATE THE LEVELS OF GLOBAL DNA METHYLATION IN THIS PATIENT GROUP. METHODS: WE ASSESSED METHYLCYTOSINE (MCYT) LEVELS IN DNA FROM BLOOD COLLECTED IN 43 COPD PATIENTS (29 WITH MILD AND 14 WITH MODERATE DISEASE) AND 43 AGE- AND SEX-MATCHED HEALTHY CONTROLS. RESULTS: DNA METHYLATION WAS SIGNIFICANTLY LOWER IN COPD PATIENTS VS. CONTROLS (4.20 +/- 0.18% MCYT VS. 4.29 +/- 0.18% MCYT, P = 0.02). FURTHERMORE, DNA METHYLATION IN COPD PATIENTS WITH MODERATE DISEASE WAS SIGNIFICANTLY LOWER THAN THAT IN PATIENTS WITH MILD DISEASE (4.14 +/- 0.15% MCYT VS. 4.23 +/- 0.19% MCYT, P < 0.05). UNIVARIATE LOGISTIC REGRESSION ANALYSIS SHOWED THAT LOWER DNA METHYLATION LEVELS WERE ASSOCIATED WITH PRESENCE OF COPD (CRUDE OR = 0.06, 95% CI 0.00 TO 0.67, P = 0.023). THIS RELATIONSHIP REMAINED SIGNIFICANT AFTER ADJUSTING FOR SEVERAL CONFOUNDERS (OR 0.03, 95% CI 0.00 TO 0.67; P = 0.028). RECEIVER OPERATING CHARACTERISTICS (ROC) CURVE ANALYSIS DEMONSTRATED THE AREA UNDER THE CURVE OF MCYT WAS 0.646, WITH 46.6% SENSITIVITY AND 79.1% SPECIFICITY FOR PRESENCE OF COPD. CONCLUSIONS: THERE WERE NO SIGNIFICANT CORRELATIONS BETWEEN METHYLATION AND OS INDICES. THE PRESENCE AND SEVERITY OF COPD IS ASSOCIATED WITH PROGRESSIVELY LOWER DNA METHYLATION IN BLOOD. HOWEVER, THIS EPIGENETIC ALTERATION SEEMS INDEPENDENT OF OXIDATIVE STRESS. 2017 13 3450 37 HYPERMETHYLATION OF THE TSPOAP1-AS1 PROMOTER MAY BE ASSOCIATED WITH OBESITY IN OVERWEIGHT/OBESE KOREAN SUBJECTS. OBESITY IS A MAJOR CHRONIC DISEASE ASSOCIATED WITH THE RISK OF SERIOUS CARDIOVASCULAR OR ENDOCRINAL DISEASES, SUCH AS HYPERTENSION, DIABETES, ATHEROSCLEROSIS AND STROKE. CONSIDERABLE INTEREST HAS BEEN DIRECTED TOWARDS THE POTENTIAL EFFECTS OF EPIGENETIC VARIATIONS IN OBESITY. IN THIS STUDY, WE EVALUATED DNA METHYLATION LEVEL AT THE PROMOTER REGION OF THE GENE ENCODING TSPO-ASSOCIATED PROTEIN 1 ANTISENSE RNA 1 (TSPOAP1-AS1) IN 80 OVERWEIGHT/OBESE SUBJECTS (BODY MASS INDEX (BMI) > 25) AND 104 NON-OBESE SUBJECTS WHO PARTICIPATED IN THE SOPI-STROKE STUDY IN KOREA. DNA METHYLATION WAS MEASURED USING BISULFITE AMPLICON SEQUENCING (BSAS). A GENERAL LINEAR MODEL OR RELATIVE CORRELATION WAS USED TO DETERMINE THE EFFECTS OF DNA METHYLATION ON OBESITY AND OBESE PHENOTYPES. NOTABLY, THE MEAN LEVEL OF DNA METHYLATION WAS SIGNIFICANTLY HIGHER IN THE OVERWEIGHT/OBESE GROUP THAN IN THE NON-OBESE GROUP (18.62% VS. 17.18%). FURTHER ANALYSES REVEALED SIGNIFICANT POSITIVE CORRELATIONS OF THE BMI, THE SERUM TOTAL CHOLESTEROL AND LOW-DENSITY LIPOPROTEIN CHOLESTEROL LEVELS WITH THE DNA METHYLATION LEVEL (P = 0.0493, P = 0.003, AND P = 0.0094, RESPECTIVELY). THE STUDY FINDINGS SUGGEST AN ASSOCIATION BETWEEN DNA METHYLATION AT THE TSPOAP1-AS1 PROMOTER AND OVERWEIGHT/OBESITY. ACCORDINGLY, METHYLATION IN THIS PROMOTER REGION MIGHT BE A POTENTIAL PREDICTOR OF OBESITY. 2020 14 2627 42 EPIGENOME-WIDE ASSOCIATION STUDY OF ADIPOSITY AND FUTURE RISK OF OBESITY-RELATED DISEASES. BACKGROUND: OBESITY IS AN ESTABLISHED RISK FACTOR FOR SEVERAL COMMON CHRONIC DISEASES SUCH AS BREAST AND COLORECTAL CANCER, METABOLIC AND CARDIOVASCULAR DISEASES; HOWEVER, THE BIOLOGICAL BASIS FOR THESE RELATIONSHIPS IS NOT FULLY UNDERSTOOD. TO EXPLORE THE ASSOCIATION OF OBESITY WITH THESE CONDITIONS, WE INVESTIGATED PERIPHERAL BLOOD LEUCOCYTE (PBL) DNA METHYLATION MARKERS FOR ADIPOSITY AND THEIR CONTRIBUTION TO RISK OF INCIDENT BREAST AND COLORECTAL CANCER AND MYOCARDIAL INFARCTION. METHODS: DNA METHYLATION PROFILES (ILLUMINA INFINIUM((R)) HUMANMETHYLATION450 BEADCHIP) FROM 1941 INDIVIDUALS FROM FOUR POPULATION-BASED EUROPEAN COHORTS WERE ANALYSED IN RELATION TO BODY MASS INDEX, WAIST CIRCUMFERENCE, WAIST-HIP AND WAIST-HEIGHT RATIO WITHIN A META-ANALYTICAL FRAMEWORK. IN A SUBSET OF THESE INDIVIDUALS, DATA ON GENOME-WIDE GENE EXPRESSION LEVEL, BIOMARKERS OF GLUCOSE AND LIPID METABOLISM WERE ALSO AVAILABLE. VALIDATION OF METHYLATION MARKERS ASSOCIATED WITH ALL ADIPOSITY MEASURES WAS PERFORMED IN 358 INDIVIDUALS. FINALLY, WE INVESTIGATED THE ASSOCIATION OF OBESITY-RELATED METHYLATION MARKS WITH BREAST, COLORECTAL CANCER AND MYOCARDIAL INFARCTION WITHIN RELEVANT SUBSETS OF THE DISCOVERY POPULATION. RESULTS: WE IDENTIFIED 40 CPG LOCI WITH METHYLATION LEVELS ASSOCIATED WITH AT LEAST ONE ADIPOSITY MEASURE. OF THESE, ONE CPG LOCUS (CG06500161) IN ABCG1 WAS ASSOCIATED WITH ALL FOUR ADIPOSITY MEASURES (P = 9.07X10(-)(8) TO 3.27X10(-18)) AND LOWER TRANSCRIPTIONAL ACTIVITY OF THE FULL-LENGTH ISOFORM OF ABCG1 (P = 6.00X10(-7)), HIGHER TRIGLYCERIDE LEVELS (P = 5.37X10(-)(9)) AND HIGHER TRIGLYCERIDES-TO-HDL CHOLESTEROL RATIO (P = 1.03X10(-10)). OF THE 40 INFORMATIVE AND OBESITY-RELATED CPG LOCI, TWO (IN IL2RB AND FGF18) WERE SIGNIFICANTLY ASSOCIATED WITH COLORECTAL CANCER (INVERSELY, P < 1.6X10(-3)) AND ONE INTERGENIC LOCUS ON CHROMOSOME 1 WAS INVERSELY ASSOCIATED WITH MYOCARDIAL INFARCTION (P < 1.25X10(-3)), INDEPENDENTLY OF OBESITY AND ESTABLISHED RISK FACTORS. CONCLUSION: OUR RESULTS SUGGEST THAT EPIGENETIC CHANGES, IN PARTICULAR ALTERED DNA METHYLATION PATTERNS, MAY BE AN INTERMEDIATE BIOMARKER AT THE INTERSECTION OF OBESITY AND OBESITY-RELATED DISEASES, AND COULD OFFER CLUES AS TO UNDERLYING BIOLOGICAL MECHANISMS. 2018 15 2046 38 EPIGENETIC CLOCK INDICATES ACCELERATED AGING IN GLIAL CELLS OF PROGRESSIVE MULTIPLE SCLEROSIS PATIENTS. BACKGROUND: MULTIPLE SCLEROSIS (MS) IS A CHRONIC INFLAMMATORY NEURODEGENERATIVE DISEASE OF THE CENTRAL NERVOUS SYSTEM (CNS) CHARACTERIZED BY IRREVERSIBLE DISABILITY AT LATER PROGRESSIVE STAGES. A GROWING BODY OF EVIDENCE SUGGESTS THAT DISEASE PROGRESSION DEPENDS ON AGE AND INFLAMMATION WITHIN THE CNS. WE AIMED TO INVESTIGATE EPIGENETIC AGING IN BULK BRAIN TISSUE AND SORTED NUCLEI FROM MS PATIENTS USING DNA METHYLATION-BASED EPIGENETIC CLOCKS. METHODS: WE APPLIED HORVATH'S MULTI-TISSUE AND SHIREBY'S BRAIN-SPECIFIC CORTICAL CLOCK ON BULK BRAIN TISSUE (N = 46), SORTED NEURONAL (N = 54), AND GLIAL NUCLEI (N = 66) FROM POST-MORTEM BRAIN TISSUE OF PROGRESSIVE MS PATIENTS AND CONTROLS. RESULTS: WE FOUND A SIGNIFICANT INCREASE IN AGE ACCELERATION RESIDUALS, CORRESPONDING TO 3.6 YEARS, IN GLIAL CELLS OF MS PATIENTS COMPARED TO CONTROLS (P = 0.0024) USING THE CORTICAL CLOCK, WHICH HELD AFTER ADJUSTMENT FOR COVARIATES (P (ADJ) = 0.0263). THE 4.8-YEAR AGE ACCELERATION FOUND IN MS NEURONS (P = 0.0054) DID NOT WITHSTAND ADJUSTMENT FOR COVARIATES AND NO SIGNIFICANT DIFFERENCE IN AGE ACCELERATION RESIDUALS WAS OBSERVED IN BULK BRAIN TISSUE BETWEEN MS PATIENTS AND CONTROLS. CONCLUSION: WHILE THE FINDINGS WARRANT REPLICATION IN LARGER COHORTS, OUR STUDY SUGGESTS THAT GLIAL CELLS OF PROGRESSIVE MS PATIENTS EXHIBIT ACCELERATED BIOLOGICAL AGING. 2022 16 1909 42 ENRICHMENT OF GENOMIC PATHWAYS BASED ON DIFFERENTIAL DNA METHYLATION PROFILES ASSOCIATED WITH CHRONIC MUSCULOSKELETAL PAIN IN OLDER ADULTS: AN EXPLORATORY STUDY. OUR STUDY AIMED TO IDENTIFY DIFFERENTIALLY METHYLATED CPGS/REGIONS AND THEIR ENRICHED GENOMIC PATHWAYS ASSOCIATED WITH UNDERLYING CHRONIC MUSCULOSKELETAL PAIN IN OLDER INDIVIDUALS. WE RECRUITED COGNITIVELY HEALTHY OLDER ADULTS WITH (N = 20) AND WITHOUT (N = 9) SELF-REPORTED MUSCULOSKELETAL PAIN AND COLLECTED DNA FROM PERIPHERAL BLOOD THAT WAS ANALYZED USING METHYLATIONEPIC ARRAYS. WE IDENTIFIED 31,739 HYPERMETHYLATED CPG AND 10,811 HYPOMETHYLATED CPG PROBES (PS 500/MICROL AND WERE ENROLLED IN THE STRATEGIC TIMING OF ANTIRETROVIRAL THERAPY TRIAL (PULMONARY SUBSTUDY) WERE COMPARED WITH 34 HIV-NEGATIVE CONTROLS. DNA METHYLATION WAS PERFORMED USING THE ILLUMINA METHYLATIONEPIC BEADCHIP. DIFFERENTIALLY METHYLATED POSITIONS (DMPS) AND DIFFERENTIALLY METHYLATED REGIONS (DMRS) IN PLWH COMPARED WITH CONTROLS WERE IDENTIFIED USING A ROBUST LINEAR MODEL. METHYLATION AGE WAS CALCULATED USING A PREVIOUSLY DESCRIBED EPIGENETIC CLOCK. RESULTS: THERE WERE A TOTAL OF 56 639 DMPS AND 6103 DMRS AT A FALSE DISCOVERY RATE OF <0.1. THE TOP 5 DMPS CORRESPONDED TO GENES NLRC5, VRK2, B2M, AND GPR6 AND WERE HIGHLY ENRICHED FOR CANCER-RELATED PATHWAYS. PLWH HAD SIGNIFICANTLY HIGHER METHYLATION AGE THAN HIV-NEGATIVE CONTROLS (P = .001), WITH BLACK RACE, LOW CD4 AND HIGH CD8 T-CELL COUNTS, AND DURATION OF HIV BEING RISK FACTORS FOR AGE ACCELERATION. CONCLUSIONS: PLWH BEFORE THE INITIATION OF ART AND WITH PRESERVED IMMUNE STATUS SHOW EVIDENCE OF ADVANCED METHYLATION AGING. 2021 18 1847 45 EFFECTS OF VARIOUS ENVIRONMENTS ON EPIGENETIC SETTINGS AND CHROMOSOMAL DAMAGE. AIR POLLUTION IS A DOMINANT ENVIRONMENTAL EXPOSURE FACTOR WITH SIGNIFICANT HEALTH CONSEQUENCES. UNEXPECTEDLY, RESEARCH IN A HEAVILY POLLUTED REGION OF THE CZECH REPUBLIC, WITH TRADITIONAL HEAVY INDUSTRY, REVEALED REPEATEDLY THE LOWEST FREQUENCY OF MICRONUCLEI IN THE SEASON WITH THE HIGHEST CONCENTRATIONS OF AIR POLLUTANTS INCLUDING CARCINOGENIC BENZO[A]PYRENE (B[A]P). MOLECULAR FINDINGS HAVE BEEN COLLECTED FOR MORE THAN 10 YEARS FROM VARIOUS LOCATIONS OF THE CZECH REPUBLIC, WITH DIFFERING QUALITY OF AMBIENT AIR. PRELIMINARY CONCLUSIONS HAVE SUGGESTED ADAPTATION OF THE POPULATION FROM THE POLLUTED LOCALITY (OSTRAVA, MORAVIAN-SILESIAN REGION (MSR)) TO CHRONIC AIR POLLUTION EXPOSURE. IN THIS STUDY WE UTILIZE THE PREVIOUS FINDINGS AND, FOR THE FIRST TIME, INVESTIGATE MICRONUCLEI (MN) FREQUENCY BY TYPE: (I) CENTROMERE POSITIVE (CEN+) MN, REPRESENTING CHROMOSOMAL LOSSES, AND (II) CENTROMERE NEGATIVE (CEN-) MN REPRESENTING CHROMOSOMAL BREAKS. AS PREVIOUS RESULTS INDICATED DIFFERENCES BETWEEN POPULATIONS IN THE EXPRESSION OF XRCC5, A GENE INVOLVED IN THE NON-HOMOLOGOUS END-JOINING (NHEJ) REPAIR PATHWAY, POSSIBLE VARIATIONS IN EPIGENETIC SETTINGS IN THIS GENE WERE ALSO INVESTIGATED. THIS NEW RESEARCH WAS CONDUCTED IN TWO SEASONS IN THE GROUPS FROM TWO LOCALITIES WITH DIFFERENT AIR QUALITY LEVELS (OSTRAVA (OS) AND PRAGUE (PG)). THE OBTAINED NEW RESULTS SHOW SIGNIFICANTLY LOWER FREQUENCIES OF CHROMOSOMAL BREAKS IN THE OS SUBJECTS, RELATED TO THE HIGHEST AIR POLLUTION LEVELS (P < 0.001). IN CONTRAST, CHROMOSOMAL LOSSES WERE COMPARABLE BETWEEN BOTH GROUPS. IN ADDITION, SIGNIFICANTLY LOWER DNA METHYLATION WAS FOUND IN 14.3% OF THE ANALYZED CPG LOCI OF XRCC5 IN THE POPULATION FROM OS. IN CONCLUSION, THE EPIGENETIC ADAPTATION (HYPOMETHYLATION) IN XRCC5 INVOLVED IN THE NHEJ REPAIR PATHWAY IN THE POPULATION FROM THE POLLUTED REGION, WAS SUGGESTED AS A REASON FOR THE REDUCED LEVEL OF CHROMOSOMAL BREAKS. FURTHER RESEARCH IS NEEDED TO EXPLORE THE ADDITIONAL MECHANISMS, INCLUDING GENETIC ADAPTATION. 2023 19 3568 37 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