1 6722 88 VITAMIN D RECEPTOR AND EPIGENETICS IN HIV INFECTION AND DRUG ABUSE. ILLICIT DRUG ABUSE IS HIGHLY PREVALENT AND SERVES AS A POWERFUL CO-FACTOR FOR HIV EXACERBATION. EPIGENETIC ALTERATIONS IN DRUG ABUSE AND HIV INFECTION DETERMINE EXPRESSION OF SEVERAL CRITICAL GENES SUCH AS VITAMIN D RECEPTOR (VDR), WHICH PARTICIPATES IN PROLIFERATION, DIFFERENTIATION, CELL DEATH UNDER BOTH PHYSIOLOGICAL AND PATHOLOGICAL CONDITIONS. ON THAT ACCOUNT, ACTIVE VITAMIN D, THE LIGAND OF VDR, IS USED AS AN ADJUVANT THERAPY TO CONTROL INFECTION, SLOW DOWN PROGRESSION OF CHRONIC KIDNEY DISEASES, AND CANCER CHEMOTHERAPY. INTERESTINGLY, VITAMIN D MAY NOT BE ABLE TO AUGMENT VDR EXPRESSION OPTIMALLY IN SEVERAL INSTANCES WHERE EPIGENETIC CONTRIBUTES TO DOWN REGULATION OF VDR; HOWEVER, REVERSAL OF EPIGENETIC CORRUPTION EITHER BY DEMETHYLATING AGENTS (DACS) OR HISTONE DEACETYLASE (HDAC) INHIBITORS WOULD BE ABLE TO MAXIMIZE EXPRESSION OF VDR IN THESE INSTANCES. 2015 2 6721 20 VITAMIN D RECEPTOR AGONISTS' ANTI-INFLAMMATORY PROPERTIES. ONE CENTURY AFTER ITS DISCOVERY, VITAMIN D HAS BEEN SHOWN TO BE, IN FACT, A PLEIOTROPIC STEROID HORMONE, WHICH, BESIDES REGULATION OF CALCIUM HOMEOSTASIS AND BONE TURNOVER, HAS ANTIPROLIFERATIVE, PRODIFFERENTIATION, ANTIBACTERIAL, IMMUNOMODULATORY, AND ANTI-INFLAMMATORY PROPERTIES IN VARIOUS CELLS AND TISSUES. D HORMONE (1ALPHA,25(OH)2 D), REGULATED IN AN ENDOCRINE, AUTOCRINE, AND PARACRINE MANNER, MUST BE BOUND TO THE SPECIFIC NUCLEAR VITAMIN D RECEPTOR (VDR) TO EXERT EPIGENETIC AND GENETIC EFFECTS, ACTING AS A CONNECTION BETWEEN EXTRACELLULAR STIMULI AND GENOMIC RESPONSES OF THE CELLS. SINCE ONLY HIGH DOSES OF HORMONE, PROVOKING HYPERCALCEMIA, CAN ACHIEVE IMMUNOMODULATORY EFFECTS, MORE THAN 3000 VDR AGONISTS HAVE BEEN SYNTHESIZED. NUMEROUS EXPERIMENTAL TRIALS HAVE BEEN PERFORMED IN ANIMAL MODELS, EVIDENCING THE PREVENTIVE AND THERAPEUTIC POTENTIAL OF VDR AGONISTS FOR CHRONIC INFLAMMATORY DISEASES AND CANCER. CONSIDERING THE SELECTIVE ANTI-INFLAMMATORY EFFECTS OF VDR AGONISTS COMPARED TO GLUCOCORTICOIDS, SPARING MICROBICIDAL FUNCTIONS, THE FEAR OF HYPERCALCEMIA AS THEIR ONLY FREQUENT SIDE EFFECT BECOMES A QUESTIONABLE REASON FOR THE LACK OF CLINICAL STUDIES. 2014 3 6723 27 VITAMIN D RECEPTOR GENE METHYLATION IN HEPATOCELLULAR CARCINOMA. WORLDWIDE, HEPATOCELLULAR CARCINOMA (HCC) IS THE MAJOR SUBTYPE OF PRIMARY LIVER CANCERS. HCC IS TYPICALLY DIAGNOSED LATE IN ITS COURSE. WITH RESPECT TO CANCER, THE GENOMIC ACTIONS OF VITAMIN D ARE MEDIATED THROUGH BINDING TO THE VITAMIN D RECEPTOR (VDR), WHICH ALLOWS IT TO MODULATE THE EXPRESSION OF GENES IN A CELL-AND TISSUE-SPECIFIC MANNER. EPIGENETICS IS A RAPIDLY EVOLVING FIELD OF GENETIC STUDY APPLICABLE TO HCC. CHANGES IN DNA METHYLATION PATTERNS ARE THOUGHT TO BE EARLY EVENTS IN HEPATOCARCINOGENESIS. CURCUMIN HAS GREAT POTENTIAL AS AN EPIGENETIC AGENT. ACCORDINGLY, THE CURRENT STUDY HAS BEEN DESIGNED TO STUDY THE METHYLATION STATUS OF VDR GENE PROMOTER FOR THE FIRST TIME IN HCC AIMING TO FIND ITS CLINICAL SIGNIFICANCE AND POTENTIAL SCREENING ROLE IN CHRONIC LIVER DISEASE (CLD). ADDITIONALLY, WE AIMED TO INVESTIGATE, THE EFFECT OF CURCUMIN ON HCC CELL LINE, AIMING TO DISCOVER NEW THERAPEUTIC TARGETS THROUGH EPIGENETICS. THIS STUDY WAS CONDUCTED ON 45 FORMALIN-FIXED, PARAFFIN-EMBEDDED LIVER TISSUE BLOCKS INCLUDING 15 HCC SAMPLES (GROUP A), 15 CLD SAMPLES (GROUP B) AND 15 APPARENTLY NORMAL TISSUE TAKEN FROM AROUND BENIGN LESIONS (GROUP C). METHYLATION SPECIFIC RESTRICTION DIGESTION AND QPCR WERE DONE ON ALL SAMPLES AFTER DNA EXTRACTION. THE PERCENTAGE OF VDR GENE PROMOTER METHYLATION WAS SIGNIFICANTLY HIGHER IN THE HCC GROUP COMPARED TO BOTH CLD AND CONTROL GROUPS (P < 0.01). VDR PROMOTER METHYLATION BY (MS-QPCR) WAS DECREASED AND THE RELATIVE EXPRESSION OF VDR BY (QRT-PCR) WAS MARKEDLY INCREASED IN A DOSE-DEPENDENT FASHION IN CELLS GROWN IN CURCUMIN-ADEQUATE MEDIUM. IN CONCLUSION, THIS STUDY MAY OPEN A NEW GATE FOR THE USE OF VDR PROMOTER METHYLATION AS A POTENTIAL BIOMARKER IN HCC. 2018 4 6719 33 VITAMIN D AND SUSCEPTIBILITY OF CHRONIC LUNG DISEASES: ROLE OF EPIGENETICS. VITAMIN D DEFICIENCY IS LINKED TO ACCELERATED DECLINE IN LUNG FUNCTION, INCREASED INFLAMMATION, AND REDUCED IMMUNITY IN CHRONIC LUNG DISEASES. EPIDEMIOLOGICAL STUDIES HAVE SUGGESTED THAT VITAMIN D INSUFFICIENCY IS ASSOCIATED WITH LOW LUNG FUNCTION IN SUSCEPTIBLE SUBJECTS WHO ARE EXPOSED TO HIGHER LEVELS OF ENVIRONMENTAL AGENTS (AIRBORNE PARTICULATES). RECENT STUDIES HAVE HIGHLIGHTED THE ROLE OF VITAMIN D AND VITAMIN D RECEPTOR (VDR) IN REGULATION OF SEVERAL GENES THAT ARE INVOLVED IN INFLAMMATION, IMMUNITY, CELLULAR PROLIFERATION, DIFFERENTIATION, AND APOPTOSIS. VITAMIN D HAS ALSO BEEN IMPLICATED IN REVERSAL OF STEROID RESISTANCE AND AIRWAY REMODELING, WHICH ARE THE HALLMARKS OF CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) AND SEVERE ASTHMA. VDR PROTEIN LEVEL IS DECREASED IN LUNGS OF PATIENTS WITH COPD. VDR DEFICIENT MICE DEVELOP AN ABNORMAL LUNG PHENOTYPE WITH CHARACTERISTICS OF COPD, SUCH AS AIRSPACE ENLARGEMENT AND DECLINE IN LUNG FUNCTION ASSOCIATED WITH INCREASED LUNG INFLAMMATORY CELLULAR INFLUX, AND IMMUNE-LYMPHOID AGGREGATES FORMATION. DIETARY VITAMIN D MAY REGULATE EPIGENETIC EVENTS, IN PARTICULAR ON GENES WHICH ARE RESPONSIBLE FOR COPD SUSCEPTIBILITY. ACTIVE METABOLITE OF VITAMIN D, 1,25-DIHYDROXYVITAMIN D(3) PLAYS AN ESSENTIAL ROLE IN CELLULAR METABOLISM AND DIFFERENTIATION VIA ITS NUCLEAR RECEPTOR (VDR) THAT COOPERATES WITH SEVERAL OTHER CHROMATIN MODIFICATION ENZYMES (HISTONE ACETYLTRANSFERASES AND HISTONE DEACETYLASES), THEREBY MEDIATING COMPLEX EPIGENETIC EVENTS IN VITAMIN D SIGNALING AND METABOLISM. THIS REVIEW PROVIDES AN UPDATE ON THE CURRENT KNOWLEDGE AND UNDERSTANDING ON VITAMIN D, AND SUSCEPTIBILITY OF CHRONIC LUNG DISEASES IN RELATION TO THE POSSIBLE ROLE OF EPIGENETICS IN ITS MOLECULAR ACTION. UNDERSTANDING THE MOLECULAR EPIGENETIC MECHANISM OF VITAMIN D/VDR WOULD PROVIDE RATIONALE FOR DIETARY VITAMIN D-MEDIATED INTERVENTION IN PREVENTION AND MANAGEMENT OF CHRONIC LUNG DISEASES LINKED WITH VITAMIN D DEFICIENCY. 2011 5 2110 22 EPIGENETIC FINDINGS IN PERIODONTITIS IN UK TWINS: A CROSS-SECTIONAL STUDY. BACKGROUND: GENETIC AND ENVIRONMENTAL RISK FACTORS CONTRIBUTE TO PERIODONTAL DISEASE, BUT THE UNDERLYING SUSCEPTIBILITY PATHWAYS ARE NOT FULLY UNDERSTOOD. EPIGENETIC MECHANISMS ARE MALLEABLE REGULATORS OF GENE FUNCTION THAT CAN CHANGE IN RESPONSE TO GENETIC AND ENVIRONMENTAL STIMULI, THEREBY PROVIDING A POTENTIAL MECHANISM FOR MEDIATING RISK EFFECTS IN PERIODONTITIS. THE AIM OF THIS STUDY IS TO IDENTIFY EPIGENETIC CHANGES ACROSS TISSUES THAT ARE ASSOCIATED WITH PERIODONTAL DISEASE. METHODS: SELF-REPORTED GINGIVAL BLEEDING AND HISTORY OF GUM DISEASE, OR TOOTH MOBILITY, WERE USED AS INDICATORS OF PERIODONTAL DISEASE. DNA METHYLATION PROFILES WERE GENERATED USING THE INFINIUM HUMANMETHYLATION450 BEADCHIP IN WHOLE BLOOD, BUCCAL, AND ADIPOSE TISSUE SAMPLES FROM PREDOMINANTLY OLDER FEMALE TWINS (MEAN AGE 58) FROM THE TWINSUK COHORT. EPIGENOME-WIDE ASSOCIATION SCANS (EWAS) OF GINGIVAL BLEEDING AND TOOTH MOBILITY WERE CONDUCTED IN WHOLE BLOOD IN 528 AND 492 TWINS, RESPECTIVELY. SUBSEQUENTLY, TARGETED CANDIDATE GENE ANALYSIS AT 28 GENOMIC REGIONS WAS CARRIED OUT TESTING FOR PHENOTYPE-METHYLATION ASSOCIATIONS IN 41 (TOOTH MOBILITY) AND 43 (GINGIVAL BLEEDING) BUCCAL, AND 501 (TOOTH MOBILITY) AND 556 (GINGIVAL BLEEDING) ADIPOSE DNA SAMPLES. RESULTS: EPIGENOME-WIDE ANALYSES IN BLOOD IDENTIFIED ONE CPG-SITE (CG21245277 IN ZNF804A) ASSOCIATED WITH GINGIVAL BLEEDING (FDR = 0.03, NOMINAL P VALUE = 7.17E-8) AND 58 SITES ASSOCIATED WITH TOOTH MOBILITY (FDR < 0.05) WITH THE TOP SIGNALS IN IQCE AND XKR6. EPIGENETIC VARIATION AT 28 CANDIDATE REGIONS (247 CPG-SITES) FOR CHRONIC PERIODONTITIS SHOWED AN ENRICHMENT FOR ASSOCIATION WITH PERIODONTAL TRAITS, AND SIGNALS IN EIGHT GENES (VDR, IL6ST, TMCO6, IL1RN, CD44, IL1B, WHAMM, AND CXCL1) WERE SIGNIFICANT IN BOTH TRAITS. THE METHYLATION-PHENOTYPE ASSOCIATION SIGNALS VALIDATED IN BUCCAL SAMPLES, AND A SUBSET (25%) ALSO VALIDATED IN ADIPOSE TISSUE. CONCLUSIONS: EPIGENOME-WIDE ANALYSES IN ADULT FEMALE TWINS IDENTIFIED SPECIFIC DNA METHYLATION CHANGES LINKED TO SELF-REPORTED PERIODONTAL DISEASE. FUTURE WORK WILL EXPLORE THE ENVIRONMENTAL BASIS AND FUNCTIONAL IMPACT OF THESE RESULTS TO INFER POTENTIAL FOR STRATEGIC PERSONALIZED TREATMENTS AND PREVENTION OF CHRONIC PERIODONTITIS. 2019 6 6398 33 THE ROLE OF VITAMIN D AND VDR IN CARCINOGENESIS: THROUGH EPIDEMIOLOGY AND BASIC SCIENCES. IN THE LAST TWO DECADES VITAMIN D (VD) RESEARCH HAS DEMONSTRATED NEW EXTRASKELETAL ACTIONS OF THIS PRE-HORMONE, SUGGESTING A PROTECTIVE ROLE OF THIS SECOSTEROID IN THE ONSET, PROGRESSION AND PROGNOSIS OF SEVERAL CHRONIC NONCOMMUNICABLE DISEASES, SUCH AS CARDIOVASCULAR DISEASE, DIABETES MELLITUS OR CANCER. REGARDING CARCINOGENESIS, BOTH PRECLINICAL AND EPIDEMIOLOGICAL EVIDENCE AVAILABLE SHOW ONCOPROTECTIVE ACTIONS OF VD AND ITS RECEPTOR, THE VDR. HOWEVER, IN LATE NEOPLASTIC STAGES THE VD SYSTEM (VDS) SEEMS TO BE LESS FUNCTIONAL, WHICH APPEARS TO BE DUE TO AN EPIGENETIC SILENCING OF THE SYSTEM. IN PRECLINICAL EXPERIMENTAL STUDIES, VD PRESENTS ONCOPROTECTIVE ACTIONS THROUGH MODULATION OF INFLAMMATION, CELL PROLIFERATION, CELL DIFFERENTIATION, ANGIOGENESIS, INVASIVE AND METASTATIC POTENTIAL, APOPTOSIS, MIRNA EXPRESSION REGULATION AND MODULATION OF THE HEDGEHOG SIGNALLING PATHWAY. MOREOVER, EPIDEMIOLOGICAL EVIDENCE POINTS TOWARDS AN ONCOPROTECTIVE ROLE OF VITAMIN D AND VDR IN COLORECTAL CANCER. THIS ASSOCIATION IS MORE CONTROVERSIAL WITH BREAST, OVARIAN AND PROSTATE CANCERS, ALTHOUGH WITH A FEW ADVERSE EFFECTS. NONETHELESS, WE SHOULD CONSIDER OTHER FACTORS TO DETERMINE THE BENEFIT OF INCREASED SERUM CONCENTRATION OF VD. MUCH OF THE EPIDEMIOLOGICAL EVIDENCE IS STILL INCONCLUSIVE, AND WE WILL HAVE TO WAIT FOR NEW, BETTER-DESIGNED ONGOING RCTS AND THEIR RESULTS TO DISCERN THE REAL EFFECT OF VITAMIN D IN CANCER RISK REDUCTION AND THERAPY. THE OBJECTIVE OF THIS LITERATURE REVIEW IS TO OFFER AN UP-TO-DATE ANALYSIS OF THE ROLE OF THE VD AND VDR, IN THE ONSET, PROGRESSION AND PROGNOSIS OF ALL TYPES OF CANCER. WE FURTHER DISCUSS THE AVAILABLE LITERATURE AND SUGGEST NEW HYPOTHESES AND FUTURE CHALLENGES IN THE FIELD OF VD RESEARCH. 2017 7 6720 27 VITAMIN D METABOLISM GENES ARE DIFFERENTIALLY METHYLATED IN INDIVIDUALS WITH CHRONIC KNEE PAIN. CONTEXT: RECENT EVIDENCE SUGGESTS THAT VITAMIN D MAY INTERACT WITH THE EPIGENOME AND PLAY A ROLE IN THE PAIN EXPERIENCE. IN ORDER FOR PROPER FUNCTIONING TO OCCUR, THERE MUST BE AN ADEQUATE LEVEL OF VITAMIN D PRESENT, MADE POSSIBLE BY ENZYMATIC REACTIONS THAT ALLOW VITAMIN D TO BE BIOLOGICALLY ACTIVE. THE PURPOSE OF THIS STUDY WAS TO EXPLORE THE EPIGENETIC LANDSCAPE OF GENES INVOLVED IN VITAMIN D METABOLISM IN INDIVIDUALS WITH AND WITHOUT CHRONIC KNEE PAIN. PROCEDURES: COMMUNITY-DWELLING INDIVIDUALS RECRUITED AS PART OF A LARGER STUDY FOCUSED ON KNEE PAIN PROVIDED DEMOGRAPHIC, CLINICAL AND PAIN-RELATED INFORMATION, AS WELL AS AN INTRAVENOUS BLOOD SAMPLE TO DETERMINE DNA METHYLATION LEVELS AT CPG SITES. MAIN FINDINGS: THERE WERE DIFFERENCES IN DNA METHYLATION BETWEEN THOSE WITH AND WITHOUT PAIN IN GENES THAT CODE FOR ENZYMES RELATED TO VITAMIN D METABOLISM: CYP24A1 (24-HYDROXYLASE) AND CYP27B1 (1-?-HYDROXYLASE). THERE WAS ALSO HYPERMETHYLATION ON THE GENE THAT CODES FOR THE VITAMIN D RECEPTOR (VDR). PRINCIPAL CONCLUSIONS: THE PRESENCE OF CHRONIC PAIN IS ASSOCIATED WITH EPIGENETIC MODIFICATIONS IN GENES RESPONSIBLE FOR THE EXPRESSION OF ENZYMES INVOLVED IN VITAMIN D METABOLISM AND CELLULAR FUNCTION. THESE RESULTS LAY GROUNDWORK IN UNDERSTANDING THE MECHANISM UNDERLYING THE ASSOCIATION BETWEEN VITAMIN D AND CHRONIC PAIN. 2023 8 4855 20 OPTIMIZE DIETARY INTAKE OF VITAMIN D: AN EPIGENETIC PERSPECTIVE. PURPOSE OF REVIEW: VITAMIN D HAS RECEIVED GLOBAL ATTENTION BECAUSE OF ITS MANY HEALTH BENEFITS. ALTHOUGH THERE IS GENERAL AGREEMENT ABOUT THE IMPORTANCE OF VITAMIN D FOR BONE HEALTH, THERE REMAINS SKEPTICISM ABOUT THE NONSKELETAL HEALTH BENEFITS OF VITAMIN D. THIS REVIEW WILL NOT ONLY FOCUS ON THE VITAMIN D DEFICIENCY PANDEMIC AND WAYS TO TREAT AND PREVENT VITAMIN D DEFICIENCY BUT WILL ALSO EXPLORE THE EPIGENETIC MECHANISMS OF VITAMIN D THAT COULD HELP EXPLAIN MANY OF THE NONSKELETAL BENEFITS OF ENHANCING VITAMIN D STATUS. RECENT FINDINGS: THE INSTITUTE OF MEDICINE AND THE ENDOCRINE SOCIETY HAVE MADE NEW RECOMMENDATIONS FOR VITAMIN D INTAKE TO PREVENT VITAMIN D DEFICIENCY. VITAMIN D DEFICIENCY IS DEFINED AS A 25-HYDROXYVITAMIN D LEVEL BELOW 20 NG/ML AND VITAMIN D INSUFFICIENCY IS DEFINED AS 21-29 NG/ML. RECENT OBSERVATIONS HAVE SUGGESTED THAT VITAMIN D CAN INFLUENCE EPIGENETICS WHICH MAY HELP EXPLAIN THE NONSKELETAL HEALTH BENEFITS THAT HAVE BEEN REPORTED FOR VITAMIN D. SUMMARY: THERE IS GENERAL AGREEMENT THAT VITAMIN D DEFICIENCY IS A WORLDWIDE HEALTH PROBLEM. THIS IS DUE IN PART TO THE LACK OF APPRECIATION THAT SUNLIGHT IS AN IMPORTANT SOURCE OF VITAMIN D. THERE IS NO DOWNSIDE TO INCREASING VITAMIN D INTAKE AND RECENT OBSERVATIONS SUGGESTING THAT VITAMIN D INFLUENCES EPIGENETICS PROVIDE A NEW INSIGHT FOR THE IMPORTANCE OF VITAMIN D IN UTERO IN REDUCING RISK OF CHRONIC DISEASES LATER IN LIFE. 2012 9 3709 22 INFLUENCE OF VITAMIN D AND COTININE ON T-REGULATORY CELLS AND ASTHMA SEVERITY IN CHILDREN. ASTHMA IS A COMMON CHRONIC RESPIRATORY DISEASES IN CHILDREN. UNDERSTANDING THE IMMUNE MECHANISMS OF EPIGENETIC FACTORS MAY CONTRIBUTE TO A BETTER CONTROL OF ASTHMA. THIS STUDY SEEKS TO DETERMINE THE EFFECTS OF SERUM VITAMIN D AND URINE COTININE ON ASTHMA SEVERITY AND ON T REGULATORY CELLS (TREGS) AND OTHER IMMUNE-RELATED FACTORS SUCH AS CD3, CD4, CD8, CD19, CD16/56, AND ANTI-CD3 HLA-DR3. THE STUDY INVOLVED 34 CHILDREN WITH ASTHMA. DISEASE SEVERITY WAS ASSESSED WITH THE ASTHMA CONTROL TEST, SPIROMETRY, AND THE FRACTIONAL EXHALED NITRIC OXIDE (FENO). THE CONTROL GROUP CONSISTED OF 18 HEALTHY CHILDREN. WE FOUND A SIGNIFICANTLY LOWER PROPORTION OF TREGS IN THE SERUM OF ASTHMATIC CHILDREN COMPARED WITH THE CONTROL GROUP (P < 0.002). THERE WERE NO SIGNIFICANT DIFFERENCES IN THE OTHER IMMUNOLOGICAL FACTORS INVESTIGATED. NOR WAS THERE ANY APPRECIABLE ASSOCIATION BETWEEN VITAMIN D OR COTININE AND THE COURSE OF ASTHMA, FENO, TREGS, AND THE OTHER IMMUNE FACTORS. HOWEVER, THE PERCENTAGE OF TREGS WAS POSITIVELY ASSOCIATED WITH THE LEVEL OF FENO (P < 0.02). IN CONCLUSION, THE STUDY SHOWS A ROLE OF T REGULATORY CELLS IN THE PATHOGENESIS OF ASTHMA IN CHILDREN, BUT FAILS TO SHOW ANY INFLUENCE OF SERUM VITAMIN D OR URINE COTININE ON DISEASE COURSE. 2017 10 6725 29 VITAMIN D: NOT JUST BONE METABOLISM BUT A KEY PLAYER IN CARDIOVASCULAR DISEASES. VITAMIN D IS THE FIRST ITEM OF DRUG EXPENDITURE FOR THE TREATMENT OF OSTEOPOROSIS. ITS DEFICIENCY IS A CONDITION THAT AFFECTS NOT ONLY OLDER INDIVIDUALS BUT ALSO YOUNG PEOPLE. RECENTLY, THE SCIENTIFIC COMMUNITY HAS FOCUSED ITS ATTENTION ON THE POSSIBLE ROLE OF VITAMIN D IN THE DEVELOPMENT OF SEVERAL CHRONIC DISEASES SUCH AS CARDIOVASCULAR AND METABOLIC DISEASES. THIS REVIEW AIMS TO HIGHLIGHT THE POSSIBLE ROLE OF VITAMIN D IN CARDIOVASCULAR AND METABOLIC DISEASES. IN PARTICULAR, HERE WE EXAMINE (1) THE ROLE OF VITAMIN D IN DIABETES MELLITUS, METABOLIC SYNDROME, AND OBESITY, AND ITS INFLUENCE ON INSULIN SECRETION; (2) ITS ROLE IN ATHEROSCLEROSIS, IN WHICH CHRONIC VITAMIN D DEFICIENCY, LOWER THAN 20 NG/ML (50 NMOL/L), HAS EMERGED AMONG THE NEW RISK FACTORS; (3) THE ROLE OF VITAMIN D IN ESSENTIAL HYPERTENSION, IN WHICH LOW PLASMA LEVELS OF VITAMIN D HAVE BEEN ASSOCIATED WITH BOTH AN INCREASE IN THE PREVALENCE OF HYPERTENSION AND DIASTOLIC HYPERTENSION; (4) THE ROLE OF VITAMIN D IN PERIPHERAL ARTERIOPATHIES AND ANEURYSMAL PATHOLOGY, REPORTING THAT PATIENTS WITH PERIPHERAL ARTERY DISEASES HAD LOWER VITAMIN D VALUES THAN NON-SUFFERING PAD CONTROLS; (5) THE GENETIC AND EPIGENETIC ROLE OF VITAMIN D, HIGHLIGHTING ITS TRANSCRIPTIONAL REGULATION CAPACITY; AND (6) THE ROLE OF VITAMIN D IN CARDIAC REMODELING AND DISEASE. DESPITE THE MANY OBSERVATIONAL STUDIES AND META-ANALYSES SUPPORTING THE CRITICAL ROLE OF VITAMIN D IN CARDIOVASCULAR PHYSIOPATHOLOGY, CLINICAL TRIALS DESIGNED TO EVALUATE THE SPECIFIC ROLE OF VITAMIN D IN CARDIOVASCULAR DISEASE ARE SCARCE. THE CHARACTERIZATION OF THE IMPORTANCE OF VITAMIN D AS A MARKER OF PATHOLOGY SHOULD REPRESENT A FUTURE RESEARCH CHALLENGE. 2021 11 6598 19 TWINSUK: THE UK ADULT TWIN REGISTRY UPDATE. TWINSUK IS THE LARGEST COHORT OF COMMUNITY-DWELLING ADULT TWINS IN THE UK. THE REGISTRY COMPRISES OVER 14,000 VOLUNTEER TWINS (14,838 INCLUDING MIXED, SINGLE AND TRIPLETS); IT IS PREDOMINANTLY FEMALE (82%) AND MIDDLE-AGED (MEAN AGE 59). IN ADDITION, OVER 1800 PARENTS AND SIBLINGS OF TWINS ARE REGISTERED VOLUNTEERS. DURING THE LAST 27 YEARS, TWINSUK HAS COLLECTED NUMEROUS QUESTIONNAIRE RESPONSES, PHYSICAL/COGNITIVE MEASURES AND BIOLOGICAL MEASURES ON OVER 8500 SUBJECTS. DATA WERE COLLECTED ALONGSIDE FOUR COMPREHENSIVE PHENOTYPING CLINICAL VISITS TO THE DEPARTMENT OF TWIN RESEARCH AND GENETIC EPIDEMIOLOGY, KING'S COLLEGE LONDON. SUCH COLLECTION METHODS HAVE RESULTED IN VERY DETAILED LONGITUDINAL CLINICAL, BIOCHEMICAL, BEHAVIORAL, DIETARY AND SOCIOECONOMIC COHORT CHARACTERIZATION; IT PROVIDES A MULTIDISCIPLINARY PLATFORM FOR THE STUDY OF COMPLEX DISEASE DURING THE ADULT LIFE COURSE, INCLUDING THE PROCESS OF HEALTHY AGING. THE MAJOR STRENGTH OF TWINSUK IS THE AVAILABILITY OF SEVERAL 'OMIC' TECHNOLOGIES FOR A RANGE OF SAMPLE TYPES FROM PARTICIPANTS, WHICH INCLUDES GENOMEWIDE SCANS OF SINGLE-NUCLEOTIDE VARIANTS, NEXT-GENERATION SEQUENCING, METABOLOMIC PROFILES, MICROBIOMICS, EXOME SEQUENCING, EPIGENETIC MARKERS, GENE EXPRESSION ARRAYS, RNA SEQUENCING AND TELOMERE LENGTH MEASURES. TWINSUK FACILITATES AND ACTIVELY ENCOURAGES SHARING THE 'TWINSUK' RESOURCE WITH THE SCIENTIFIC COMMUNITY - INTERESTED RESEARCHERS MAY REQUEST DATA VIA THE TWINSUK WEBSITE (HTTP://TWINSUK.AC.UK/RESOURCES-FOR-RESEARCHERS/ACCESS-OUR-DATA/) FOR THEIR OWN USE OR FUTURE COLLABORATION WITH THE STUDY TEAM. IN ADDITION, FURTHER COHORT DATA COLLECTION IS PLANNED VIA THE WELLCOME OPEN RESEARCH GATEWAY (HTTPS://WELLCOMEOPENRESEARCH.ORG/GATEWAYS). THE CURRENT ARTICLE PRESENTS AN UP-TO-DATE REPORT ON THE APPLICATION OF TECHNOLOGICAL ADVANCES, NEW STUDY PROCEDURES IN THE COHORT AND FUTURE DIRECTION OF TWINSUK. 2019 12 6718 23 VITAMIN D AND CARDIOVASCULAR DISEASES: CAUSALITY. VITAMIN D REGULATES BLOOD PRESSURE, CARDIAC FUNCTIONS, AND ENDOTHELIAL AND SMOOTH MUSCLE CELL FUNCTIONS, THUS, PLAYING AN IMPORTANT ROLE IN CARDIOVASCULAR HEALTH. OBSERVATIONAL STUDIES REPORT ASSOCIATIONS BETWEEN VITAMIN D DEFICIENCY WITH HYPERTENSION AND CARDIOVASCULAR-RELATED DEATHS. PEER-REVIEWED PAPERS WERE EXAMINED IN SEVERAL RESEARCH DATABASES AS PER THE GUIDELINES OF THE PREFERRED REPORTING ITEMS FOR SYSTEMATIC REVIEWS, USING KEY WORDS THAT ADDRESS THE RELATIONSHIP BETWEEN VITAMIN D AND CARDIOVASCULAR DISEASE. CORRELATIONS AND INTERPRETATIONS WERE MADE CONSIDERING THE RISKS-BENEFITS, BROADER EVIDENCE, AND IMPLICATIONS. THIS REVIEW ANALYZED CURRENT KNOWLEDGE REGARDING THE EFFECTS OF VITAMIN D ON THE CARDIOVASCULAR SYSTEM. 1,25(OH)(2)D AND RELATED EPIGENETIC MODIFICATIONS SUBDUE CELLULAR INFLAMMATION, IMPROVE OVERALL ENDOTHELIAL FUNCTIONS, REDUCE AGE-RELATED SYSTOLIC HYPERTENSION AND VASCULAR RIGIDITY, AND ATTENUATE THE ACTIONS OF THE RENIN-ANGIOTENSIN-ALDOSTERONE SYSTEM. MOST OBSERVATIONAL AND ECOLOGICAL STUDIES SUPPORT 25(OH)VITAMIN D HAVING PROTECTIVE EFFECTS ON THE CARDIOVASCULAR SYSTEM. HOWEVER, THE ASSOCIATION OF VITAMIN D DEFICIENCY WITH CARDIOVASCULAR DISEASES IS BASED PRIMARILY ON OBSERVATIONAL AND ECOLOGICAL STUDIES AND THUS, IS A MATTER OF CONTROVERSY. ADEQUATELY POWERED, RANDOMIZED CONTROLLED CLINICAL TRIAL DATA ARE NOT AVAILABLE TO CONFIRM THESE ASSOCIATIONS. THUS, TO TEST THE HYPOTHESIS THAT CORRECTION OF VITAMIN D DEFICIENCY PROTECTS THE CARDIOVASCULAR SYSTEM, WELL-DESIGNED, STATISTICALLY POWERED, LONGER-TERM CLINICAL TRIALS ARE NEEDED IN PERSONS WITH VITAMIN D DEFICIENCY. NEVERTHELESS, THE AVAILABLE DATA SUPPORT THAT ADEQUATE VITAMIN D SUPPLEMENTATION AND/OR SENSIBLE SUNLIGHT EXPOSURE TO ACHIEVE OPTIMAL VITAMIN D STATUS ARE IMPORTANT IN THE PREVENTION OF CARDIOVASCULAR DISEASE AND OTHER CHRONIC DISEASES. 2018 13 348 27 ALTERED DNA METHYLATION IS ASSOCIATED WITH ABERRANT GENE EXPRESSION IN PARENCHYMAL BUT NOT AIRWAY FIBROBLASTS ISOLATED FROM INDIVIDUALS WITH COPD. BACKGROUND: CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD) IS A HETEROGENEOUS DISEASE OF THE LUNGS THAT IS CURRENTLY THE FOURTH LEADING CAUSE OF DEATH WORLDWIDE. GENETIC FACTORS ACCOUNT FOR ONLY A SMALL AMOUNT OF COPD RISK, BUT EPIGENETIC MECHANISMS, INCLUDING DNA METHYLATION, HAVE THE POTENTIAL TO MEDIATE THE INTERACTIONS BETWEEN AN INDIVIDUAL'S GENETICS AND ENVIRONMENTAL EXPOSURE. DNA METHYLATION IS HIGHLY CELL TYPE-SPECIFIC, AND INDIVIDUAL CELL TYPE STUDIES OF DNA METHYLATION IN COPD ARE SPARSE. FIBROBLASTS ARE PRESENT WITHIN THE AIRWAY AND PARENCHYMA OF THE LUNG AND CONTRIBUTE TO THE ABERRANT DEPOSITION OF EXTRACELLULAR MATRIX IN COPD. NO ASSESSMENT OR COMPARISON OF GENOME-WIDE DNA METHYLATION PROFILES IN THE AIRWAY AND PARENCHYMAL FIBROBLASTS FROM INDIVIDUALS WITH AND WITHOUT COPD HAS BEEN UNDERTAKEN. THESE DATA PROVIDE VALUABLE INSIGHT INTO THE MOLECULAR MECHANISMS CONTRIBUTING TO COPD AND THE DIFFERING PATHOLOGIES OF SMALL AIRWAYS DISEASE AND EMPHYSEMA IN COPD. METHODS: GENOME-WIDE DNA METHYLATION WAS EVALUATED AT OVER 485,000 CPG SITES USING THE ILLUMINA INFINIUM HUMANMETHYLATION450 BEADCHIP ARRAY IN THE AIRWAY (NON-COPD N = 8, COPD N = 7) AND PARENCHYMAL FIBROBLASTS (NON-COPD N = 17, COPD N = 29) ISOLATED FROM INDIVIDUALS WITH AND WITHOUT COPD. TARGETED GENE EXPRESSION WAS ASSESSED BY QPCR IN MATCHED RNA SAMPLES. RESULTS: DIFFERENTIALLY METHYLATED DNA REGIONS WERE IDENTIFIED BETWEEN CELLS ISOLATED FROM INDIVIDUALS WITH AND WITHOUT COPD IN BOTH AIRWAY AND PARENCHYMAL FIBROBLASTS. ONLY IN PARENCHYMAL FIBROBLASTS WAS DIFFERENTIAL DNA METHYLATION ASSOCIATED WITH DIFFERENTIAL GENE EXPRESSION. A SECOND ANALYSIS OF DIFFERENTIAL DNA METHYLATION VARIABILITY IDENTIFIED 359 INDIVIDUAL DIFFERENTIALLY VARIABLE CPG SITES IN PARENCHYMAL FIBROBLASTS. NO DIFFERENTIALLY VARIABLE CPG SITES WERE IDENTIFIED IN THE AIRWAY FIBROBLASTS. FIVE DIFFERENTIALLY VARIABLE-METHYLATED CPG SITES, ASSOCIATED WITH THREE GENES, WERE SUBSEQUENTLY ASSESSED FOR GENE EXPRESSION DIFFERENCES. TWO GENES (OAT AND GRIK2) DISPLAYED SIGNIFICANTLY INCREASED GENE EXPRESSION IN CELLS ISOLATED FROM INDIVIDUALS WITH COPD. CONCLUSIONS: DIFFERENTIAL AND VARIABLE DNA METHYLATION WAS ASSOCIATED WITH COPD STATUS IN THE PARENCHYMAL FIBROBLASTS BUT NOT AIRWAY FIBROBLASTS. ABERRANT DNA METHYLATION WAS ASSOCIATED WITH ALTERED GENE EXPRESSION IMPARTING BIOLOGICAL FUNCTION TO DNA METHYLATION CHANGES. CHANGES IN DNA METHYLATION ARE THEREFORE IMPLICATED IN THE MOLECULAR MECHANISMS UNDERLYING COPD PATHOGENESIS AND MAY REPRESENT NOVEL THERAPEUTIC TARGETS. 2018 14 6716 22 VITAMIN A: TOO GOOD TO BE BAD? VITAMIN A IS A MICRONUTRIENT IMPORTANT FOR VISION, CELL GROWTH, REPRODUCTION AND IMMUNITY. BOTH DEFICIENCY AND EXCESS CONSUMING OF VITAMIN A CAUSE SEVERE HEALTH CONSEQUENCES. ALTHOUGH DISCOVERED AS THE FIRST LIPOPHILIC VITAMIN ALREADY MORE THAN A CENTURY AGO AND THE DEFINITION OF PRECISE BIOLOGICAL ROLES OF VITAMIN A IN THE SETTING OF HEALTH AND DISEASE, THERE ARE STILL MANY UNRESOLVED ISSUES RELATED TO THAT VITAMIN. PROTOTYPICALLY, THE LIVER THAT PLAYS A KEY ROLE IN THE STORAGE, METABOLISM AND HOMEOSTASIS OF VITAMIN A CRITICALLY RESPONDS TO THE VITAMIN A STATUS. ACUTE AND CHRONIC EXCESS VITAMIN A IS ASSOCIATED WITH LIVER DAMAGE AND FIBROSIS, WHILE ALSO HYPOVITAMINOSIS A IS ASSOCIATED WITH ALTERATIONS IN LIVER MORPHOLOGY AND FUNCTION. HEPATIC STELLATE CELLS ARE THE MAIN STORAGE SITE OF VITAMIN A. THESE CELLS HAVE MULTIPLE PHYSIOLOGICAL ROLES FROM BALANCING RETINOL CONTENT OF THE BODY TO MEDIATING INFLAMMATORY RESPONSES IN THE LIVER. STRIKINGLY, DIFFERENT ANIMAL DISEASE MODELS ALSO RESPOND TO VITAMIN A STATUSES DIFFERENTLY OR EVEN OPPOSING. IN THIS REVIEW, WE DISCUSS SOME OF THESE CONTROVERSIAL ISSUES IN UNDERSTANDING VITAMIN A BIOLOGY. MORE STUDIES OF THE INTERACTIONS OF VITAMIN A WITH ANIMAL GENOMES AND EPIGENETIC SETTINGS ARE ANTICIPATED IN THE FUTURE. 2023 15 1193 26 CORRELATION OF CYP2R1 GENE PROMOTER METHYLATION WITH CIRCULATING VITAMIN D LEVELS AMONG HEALTHY ADULTS. BACKGROUND & OBJECTIVES: DESPITE BEING A TROPICAL COUNTRY, VITAMIN D DEFICIENCY IS HIGHLY PREVALENT IN INDIA WITH STUDIES INDICATING 40-99 PER CENT PREVALENCE. APART FROM CALCIUM AND PHOSPHATE METABOLISM, VITAMIN D IS INVOLVED IN CELL CYCLE REGULATION, CARDIOVASCULAR, HEPATOPROTECTION. THE METABOLISM OF VITAMIN D IS REGULATED BY VITAMIN D TOOL GENES (CYP2R1/CYP27B1/CYP24A1/VDR). THE PROMOTER REGIONS OF SOME OF THESE GENES HAVE CPG ISLANDS, MAKING THEM PRONE TO METHYLATION INDUCED GENE SILENCING, WHICH MAY CAUSE A REDUCTION IN CIRCULATING VITAMIN D LEVELS. EPIGENETIC BASIS OF VITAMIN D DEFICIENCY IS YET TO BE STUDIED IN INDIA, AND HENCE, THIS PILOT STUDY WAS AIMED TO ANALYZE WHETHER METHYLATION LEVELS OF CYP2R1 GENE WERE CORRELATED WITH THE LEVELS OF 25(OH)D IN HEALTHY, ADULT INDIVIDUALS IN INDIAN POPULATION. METHODS: IN THIS CROSS-SECTIONAL STUDY, HEALTHY ADULTS OF 18-45 YR OF AGE WITH NO HISTORY OF MALABSORPTION, THYROIDECTOMY, CHRONIC ILLNESS OR THERAPEUTIC VITAMIN D SUPPLEMENTATION WERE RECRUITED. DNA METHYLATION ANALYSIS WAS CARRIED OUT BY METHYLATION SPECIFIC QUANTITATIVE PCR. SERUM CALCIUM, PHOSPHATE AND VITAMIN D LEVELS WERE ALSO QUANTIFIED. STATISTICAL ANALYSIS WAS DONE BY R 4.0.5 SOFTWARE. RESULTS: A TOTAL OF 61 APPARENTLY HEALTHY ADULTS WERE ANALYZED. THE SERUM VITAMIN D LEVELS DID NOT CORRELATE WITH CYP2R1 METHYLATION LEVELS IN OUR STUDY POPULATION. SIGNIFICANT POSITIVE CORRELATION WAS OBSERVED BETWEEN AGE AND SERUM VITAMIN D LEVELS. SIGNIFICANT ASSOCIATION OF GENDER WAS FOUND WITH CYP2R1 METHYLATION LEVELS. INTERPRETATION & CONCLUSIONS: THIS STUDY FOUND NO SIGNIFICANT CORRELATION BETWEEN LEVELS OF CYP2R1 METHYLATION AND CIRCULATING 25(OH)D DEFICIENCY. FURTHER STUDIES ON THE INDIAN POPULATION HAVING A LARGER SAMPLE SIZE INCLUDING ENTIRE VITAMIN D TOOL GENES, AMONG DIFFERENT ETHNIC GROUPS MAY BE CONDUCTED TO ELUCIDATE MOLECULAR ETIOLOGY OF CIRCULATING 25(OH)D DEFICIENCY. THE HIGH PREVALENCE OF NORMAL SERUM CALCIUM AND PHOSPHATE LEVELS AMONG VITAMIN D DEFICIENT SUBJECTS IN THIS STUDY COUPLED WITH THE STRIKINGLY HIGH PREVALENCE OF THE DEFICIENCY AT THE NATIONAL LEVEL, MAY SUGGEST THE NEED TO REVISE THE CUT-OFF CRITERIA FOR VITAMIN D DEFICIENCY IN THE INDIAN POPULATION. 2023 16 6027 17 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 17 2406 21 EPIGENETIC RESPONSES TO RHINOVIRUS EXPOSURE IN AIRWAY EPITHELIAL CELLS ARE CORRELATED WITH KEY TRANSCRIPTIONAL PATHWAYS IN CHRONIC RHINOSINUSITIS. BACKGROUND: VIRUSES MAY DRIVE IMMUNE MECHANISMS RESPONSIBLE FOR CHRONIC RHINOSINUSITIS WITH NASAL POLYPOSIS (CRSWNP), BUT LITTLE IS KNOWN ABOUT THE UNDERLYING MOLECULAR MECHANISMS. OBJECTIVES: TO IDENTIFY EPIGENETIC AND TRANSCRIPTIONAL RESPONSES TO A COMMON UPPER RESPIRATORY PATHOGEN, RHINOVIRUS (RV), THAT ARE SPECIFIC TO PATIENTS WITH CRSWNP USING A PRIMARY SINONASAL EPITHELIAL CELL CULTURE MODEL. METHODS: AIRWAY EPITHELIAL CELLS WERE COLLECTED AT SURGERY FROM PATIENTS WITH CRSWNP (CASES) AND FROM CONTROLS WITHOUT SINUS DISEASE, CULTURED, AND THEN EXPOSED TO RV OR VEHICLE FOR 48 H. DIFFERENTIAL GENE EXPRESSION AND DNA METHYLATION (DNAM) BETWEEN CASES AND CONTROLS IN RESPONSE TO RV WERE DETERMINED USING LINEAR MIXED MODELS. WEIGHTED GENE CO-EXPRESSION ANALYSIS (WGCNA) WAS USED TO IDENTIFY (A) CO-REGULATED GENE EXPRESSION AND DNAM SIGNATURES, AND (B) GENES, PATHWAYS, AND REGULATORY MECHANISMS SPECIFIC TO CRSWNP. RESULTS: WE IDENTIFIED 5585 DIFFERENTIAL TRANSCRIPTIONAL AND 261 DNAM RESPONSES (FDR <0.10) TO RV BETWEEN CRSWNP CASES AND CONTROLS. THESE DIFFERENTIAL RESPONSES FORMED THREE CO-EXPRESSION/CO-METHYLATION MODULES THAT WERE RELATED TO CRSWNP AND THREE THAT WERE RELATED TO RV (BONFERRONI CORRECTED P < .01). MOST (95%) OF THE DIFFERENTIALLY METHYLATED CPGS (DMCS) WERE IN MODULES RELATED TO CRSWNP, WHEREAS THE DIFFERENTIALLY EXPRESSED GENES (DEGS) WERE MORE EQUALLY DISTRIBUTED BETWEEN THE CRSWNP- AND RV-RELATED MODULES. GENES IN THE CRSWNP-RELATED MODULES WERE ENRICHED IN KNOWN CRS AND/OR VIRAL RESPONSE IMMUNE PATHWAYS. CONCLUSION: RV ACTIVATES SPECIFIC EPIGENETIC PROGRAMS AND CORRELATED TRANSCRIPTIONAL NETWORKS IN THE SINONASAL EPITHELIUM OF INDIVIDUALS WITH CRSWNP. THESE NOVEL OBSERVATIONS SUGGEST EPIGENETIC SIGNATURES SPECIFIC TO PATIENTS WITH CRSWNP MODULATE RESPONSE TO VIRAL PATHOGENS AT THE MUCOSAL ENVIRONMENTAL INTERFACE. DETERMINING HOW VIRAL RESPONSE PATHWAYS ARE INVOLVED IN EPITHELIAL INFLAMMATION IN CRSWNP COULD LEAD TO THERAPEUTIC TARGETS FOR THIS BURDENSOME AIRWAY DISORDER. 2023 18 1439 25 DIFFERENTIAL PLACENTAL CPG METHYLATION IS ASSOCIATED WITH CHRONIC LUNG DISEASE OF PREMATURITY. BACKGROUND: CHRONIC LUNG DISEASE (CLD) IS THE MOST COMMON PULMONARY MORBIDITY IN EXTREMELY PRETERM INFANTS. IT IS UNCLEAR TO WHAT EXTENT PRENATAL EXPOSURES INFLUENCE THE RISK OF CLD. EPIGENETIC VARIATION IN PLACENTA DNA METHYLATION MAY BE ASSOCIATED WITH DIFFERENTIAL RISK OF CLD, AND THESE ASSOCIATIONS MAY BE DEPENDENT UPON SEX. METHODS: DATA WERE OBTAINED FROM A MULTI-CENTER COHORT OF INFANTS BORN EXTREMELY PRETERM (<28 WEEKS' GESTATION) AND AN EPIGENOME-WIDE APPROACH WAS USED TO IDENTIFY ASSOCIATIONS BETWEEN PLACENTAL DNA METHYLATION AND CLD (N = 423). ASSOCIATIONS WERE EVALUATED USING ROBUST LINEAR REGRESSION ADJUSTING FOR COVARIATES, WITH A FALSE DISCOVERY RATE OF 0.05. ANALYSES STRATIFIED BY SEX WERE USED TO ASSESS DIFFERENCES IN METHYLATION-CLD ASSOCIATIONS. RESULTS: CLD WAS ASSOCIATED WITH DIFFERENTIAL METHYLATION AT 49 CPG SITES REPRESENTING 46 GENES IN THE PLACENTA. CLD WAS ASSOCIATED WITH DIFFERENTIAL METHYLATION OF PROBES WITHIN GENES RELATED TO PATHWAYS INVOLVED IN FETAL LUNG DEVELOPMENT, SUCH AS P53 SIGNALING AND MYO-INOSITOL BIOSYNTHESIS. ASSOCIATIONS BETWEEN CPG METHYLATION AND CLD DIFFERED BY SEX. CONCLUSIONS: DIFFERENTIAL PLACENTAL METHYLATION WITHIN GENES WITH KEY ROLES IN FETAL LUNG DEVELOPMENT MAY REFLECT COMPLEX CELL SIGNALING BETWEEN THE PLACENTA AND FETUS WHICH MEDIATE CLD RISK. THESE PATHWAYS APPEAR TO BE DISTINCT BASED ON FETAL SEX. IMPACT: IN EXTREMELY PRETERM INFANTS, DIFFERENTIAL METHYLATION OF CPG SITES WITHIN PLACENTAL GENES INVOLVED IN PATHWAYS RELATED TO CELL SIGNALING, OXIDATIVE STRESS, AND TROPHOBLAST INVASION IS ASSOCIATED WITH CHRONIC LUNG DISEASE OF PREMATURITY. DNA METHYLATION PATTERNS ASSOCIATED WITH CHRONIC LUNG DISEASE WERE DISTINCTLY BASED ON FETAL SEX, SUGGESTING A POTENTIAL MECHANISM UNDERLYING DIMORPHIC PHENOTYPES. MECHANISMS RELATED TO FETAL HYPOXIA AND PLACENTAL MYO-INOSITOL SIGNALING MAY PLAY A ROLE IN FETAL LUNG PROGRAMMING AND THE DEVELOPMENTAL ORIGINS OF CHRONIC LUNG DISEASE. CONTINUED RESEARCH OF THE RELATIONSHIP BETWEEN THE PLACENTAL EPIGENOME AND CHRONIC LUNG DISEASE COULD INFORM EFFORTS TO AMELIORATE OR PREVENT THIS CONDITION. 2022 19 3063 24 GENOME-WIDE DNA METHYLATION AND LONG-TERM AMBIENT AIR POLLUTION EXPOSURE IN KOREAN ADULTS. BACKGROUND: AMBIENT AIR POLLUTION IS ASSOCIATED WITH NUMEROUS ADVERSE HEALTH OUTCOMES, BUT THE UNDERLYING MECHANISMS ARE NOT WELL UNDERSTOOD; EPIGENETIC EFFECTS INCLUDING ALTERED DNA METHYLATION COULD PLAY A ROLE. TO EVALUATE ASSOCIATIONS OF LONG-TERM AIR POLLUTION EXPOSURE WITH DNA METHYLATION IN BLOOD, WE CONDUCTED AN EPIGENOME-WIDE ASSOCIATION STUDY IN A KOREAN CHRONIC OBSTRUCTIVE PULMONARY DISEASE COHORT (N = 100 INCLUDING 60 CASES) USING ILLUMINA'S INFINIUM HUMANMETHYLATION450K BEADCHIP. ANNUAL AVERAGE CONCENTRATIONS OF PARTICULATE MATTER