1 3487 165 IDENTIFICATION OF DIFFERENTIALLY METHYLATED SITES WITH WEAK METHYLATION EFFECTS. DEOXYRIBONUCLEIC ACID (DNA) METHYLATION IS AN EPIGENETIC ALTERATION CRUCIAL FOR REGULATING STRESS RESPONSES. IDENTIFYING LARGE-SCALE DNA METHYLATION AT SINGLE NUCLEOTIDE RESOLUTION IS MADE POSSIBLE BY WHOLE GENOME BISULFITE SEQUENCING. AN ESSENTIAL TASK FOLLOWING THE GENERATION OF BISULFITE SEQUENCING DATA IS TO DETECT DIFFERENTIALLY METHYLATED CYTOSINES (DMCS) AMONG TREATMENTS. MOST STATISTICAL METHODS FOR DMC DETECTION DO NOT CONSIDER THE DEPENDENCY OF METHYLATION PATTERNS ACROSS THE GENOME, THUS POSSIBLY INFLATING TYPE I ERROR. FURTHERMORE, SMALL SAMPLE SIZES AND WEAK METHYLATION EFFECTS AMONG DIFFERENT PHENOTYPE CATEGORIES MAKE IT DIFFICULT FOR THESE STATISTICAL METHODS TO ACCURATELY DETECT DMCS. TO ADDRESS THESE ISSUES, THE WAVELET-BASED FUNCTIONAL MIXED MODEL (WFMM) WAS INTRODUCED TO DETECT DMCS. TO FURTHER EXAMINE THE PERFORMANCE OF WFMM IN DETECTING WEAK DIFFERENTIAL METHYLATION EVENTS, WE USED BOTH SIMULATED AND EMPIRICAL DATA AND COMPARE WFMM PERFORMANCE TO A POPULAR DMC DETECTION TOOL METHYLKIT. ANALYSES OF SIMULATED DATA THAT REPLICATED THE EFFECTS OF THE HERBICIDE GLYPHOSATE ON DNA METHYLATION IN ARABIDOPSIS THALIANA SHOW THAT WFMM RESULTS IN HIGHER SENSITIVITY AND SPECIFICITY IN DETECTING DMCS COMPARED TO METHYLKIT, ESPECIALLY WHEN THE METHYLATION DIFFERENCES AMONG PHENOTYPE GROUPS ARE SMALL. MOREOVER, THE PERFORMANCE OF WFMM IS ROBUST WITH RESPECT TO SMALL SAMPLE SIZES, MAKING IT PARTICULARLY ATTRACTIVE CONSIDERING THE CURRENT HIGH COSTS OF BISULFITE SEQUENCING. ANALYSIS OF EMPIRICAL ARABIDOPSIS THALIANA DATA UNDER VARYING GLYPHOSATE DOSAGES, AND THE ANALYSIS OF MONOZYGOTIC (MZ) TWINS WHO HAVE DIFFERENT PAIN SENSITIVITIES-BOTH DATASETS HAVE WEAK METHYLATION EFFECTS OF <1%-SHOW THAT WFMM CAN IDENTIFY MORE RELEVANT DMCS RELATED TO THE PHENOTYPE OF INTEREST THAN METHYLKIT. DIFFERENTIALLY METHYLATED REGIONS (DMRS) ARE GENOMIC REGIONS WITH DIFFERENT DNA METHYLATION STATUS ACROSS BIOLOGICAL SAMPLES. DMRS AND DMCS ARE ESSENTIALLY THE SAME CONCEPTS, WITH THE ONLY DIFFERENCE BEING HOW METHYLATION INFORMATION ACROSS THE GENOME IS SUMMARIZED. IF METHYLATION LEVELS ARE DETERMINED BY GROUPING NEIGHBORING CYTOSINE SITES, THEN THEY ARE DMRS; IF METHYLATION LEVELS ARE CALCULATED BASED ON SINGLE CYTOSINES, THEY ARE DMCS. 2018 2 3438 34 HYPERHOMOCYSTEINEMIA IN UREMIA--A RED FLAG IN A DISRUPTED CIRCUIT. HYPERHOMOCYSTEINEMIA IS AN INDEPENDENT CARDIOVASCULAR RISK FACTOR, ACCORDING TO MOST OBSERVATIONAL STUDIES AND TO STUDIES USING THE MENDELIAN RANDOMIZATION APPROACH, UTILIZING THE COMMON POLYMORPHISM C677T OF METHYLENE TETRAHYDROFOLATE REDUCTASE. IN CONTRAST, THE MOST RECENT SECONDARY PREVENTIVE INTERVENTION STUDIES, IN THE GENERAL POPULATION AND IN CHRONIC KIDNEY DISEASE (CKD) AND UREMIA, WHICH ARE ALL NEGATIVE (WITH THE POSSIBLE NOTABLE EXCEPTION OF STROKE), POINT TO OTHER DIRECTIONS. HOWEVER, ALL TRIALS USE FOLIC ACID IN VARIOUS DOSAGES AS A MEANS TO REDUCE HOMOCYSTEINE LEVELS, WITH THE ADDITION OF VITAMINS B6 AND B12. IT IS POSSIBLE THAT FOLIC ACID HAS NEGATIVE EFFECTS, WHICH OFFSET THE BENEFITS; ALTERNATIVELY, HOMOCYSTEINE COULD BE AN INNOCENT BY-STANDER, OR A SURROGATE OF THE REAL CULPRIT. THE LATTER POSSIBILITY LEADS US TO THE SEARCH FOR POTENTIAL CANDIDATES. FIRST, THE ACCUMULATION OF HOMOCYSTEINE IN BLOOD LEADS TO AN INTRACELLULAR INCREASE OF S-ADENOSYLHOMOCYSTEINE (ADOHCY), A POWERFUL COMPETITIVE METHYLTRANSFERASE INHIBITOR, WHICH BY ITSELF IS CONSIDERED A PREDICTOR OF CARDIOVASCULAR EVENTS. DNA METHYLTRANSFERASES ARE AMONG THE PRINCIPAL TARGETS OF HYPERHOMOCYSTEINEMIA, AS STUDIES IN SEVERAL CELL CULTURE AND ANIMAL MODELS, AS WELL AS IN HUMANS, SHOW. IN CKD AND IN UREMIA, HYPERHOMOCYSTEINEMIA AND HIGH INTRACELLULAR ADOHCY ARE PRESENT AND ARE ASSOCIATED WITH ABNORMAL ALLELIC EXPRESSION OF GENES REGULATED THROUGH METHYLATION, SUCH AS IMPRINTED GENES, AND PSEUDOAUTOSOMAL GENES, THUS POINTING TO EPIGENETIC DYSREGULATION. THESE ALTERATIONS ARE SUSCEPTIBLE TO REVERSAL UPON HOMOCYSTEINE-LOWERING THERAPY OBTAINED THROUGH FOLATE ADMINISTRATION. SECOND, IT HAS TO BE KEPT IN MIND THAT HOMOCYSTEINE IS MAINLY PROTEIN-BOUND, AND ITS EFFECTS COULD BE LINKED THEREFORE TO PROTEIN HOMOCYSTEINYLATION. IN THIS RESPECT, INCREASED PROTEIN HOMOCYSTEINYLATION HAS BEEN FOUND IN UREMIA, LEADING TO ALTERATIONS IN PROTEIN FUNCTION. 2009 3 1784 46 EFFECT OF ALCOHOL CONSUMPTION ON CPG METHYLATION IN THE DIFFERENTIALLY METHYLATED REGIONS OF H19 AND IG-DMR IN MALE GAMETES: IMPLICATIONS FOR FETAL ALCOHOL SPECTRUM DISORDERS. BACKGROUND: EXPOSURE TO ALCOHOL IN UTERO IS THE MAIN ATTRIBUTABLE CAUSE OF FETAL ALCOHOL SPECTRUM DISORDERS (FASD) WHICH IN ITS MOST SEVERE FORM IS CHARACTERIZED BY IRREVERSIBLE BEHAVIORAL AND COGNITIVE DISABILITY. PATERNAL PRECONCEPTION DRINKING IS NOT CONSIDERED TO BE A SIGNIFICANT RISK FACTOR, EVEN THOUGH ANIMAL STUDIES HAVE DEMONSTRATED THAT CHRONIC PATERNAL ALCOHOL CONSUMPTION HAS A DETRIMENTAL EFFECT ON THE PHYSICAL AND MENTAL DEVELOPMENT OF OFFSPRING EVEN IN THE ABSENCE OF IN UTERO ALCOHOL EXPOSURE. IT HAS BEEN DOCUMENTED THAT ALCOHOL CAN REDUCE THE LEVELS AND ACTIVITY OF DNA METHYLTRANSFERASES RESULTING IN DNA HYPOMETHYLATION AND THAT REDUCED METHYLTRANSFERASE ACTIVITY CAN CAUSE ACTIVATION OF NORMALLY SILENCED GENES. THE AIM OF THIS STUDY WAS TO ESTABLISH A LINK BETWEEN ALCOHOL USE IN MEN AND HYPOMETHYLATION OF PATERNALLY IMPRINTED LOCI IN SPERM DNA IN GENOMIC REGIONS CRITICAL FOR EMBRYONIC DEVELOPMENT, THUS PROVIDING A MECHANISM FOR PATERNAL EFFECTS IN THE AETIOLOGY OF FASD. METHODS: SPERM DNA FROM MALE VOLUNTEERS WAS BISULFITE TREATED AND THE METHYLATION PATTERNS OF 2 DIFFERENTIALLY METHYLATED REGIONS (DMRS), H19 AND IG-DMR, ANALYZED FOLLOWING SEQUENCING OF INDIVIDUAL CLONES. THE METHYLATION PATTERNS WERE CORRELATED WITH THE ALCOHOL CONSUMPTION LEVELS OF THE VOLUNTEER MALES. RESULTS: THERE WAS A PATTERN OF INCREASED DEMETHYLATION WITH ALCOHOL CONSUMPTION AT THE 2 IMPRINTED LOCI WITH A SIGNIFICANT DIFFERENCE OBSERVED AT THE IG-DMR BETWEEN THE NONDRINKING AND HEAVY ALCOHOL CONSUMING GROUPS. GREATER INTER-INDIVIDUAL VARIATION IN AVERAGE METHYLATION WAS OBSERVED AT THE H19 DMR AND INDIVIDUAL CLONES WERE MORE EXTENSIVELY DEMETHYLATED THAN THOSE OF THE IG-DMR. CPG SITE #4 IN THE IG-DMR WAS PREFERENTIALLY DEMETHYLATED AMONG ALL INDIVIDUALS AND ALONG WITH THE H19 DMR CPG SITE #7 LOCATED WITHIN THE CTCF BINDING SITE 6 SHOWED SIGNIFICANT DEMETHYLATION IN THE ALCOHOL CONSUMING GROUPS COMPARED WITH THE CONTROL GROUP. CONCLUSION: THIS STUDY DEMONSTRATES A CORRELATION BETWEEN CHRONIC ALCOHOL USE AND DEMETHYLATION OF NORMALLY HYPERMETHYLATED IMPRINTED REGIONS IN SPERM DNA. WE HYPOTHESIZE THAT, SHOULD THESE EPIGENETIC CHANGES IN IMPRINTED GENES BE TRANSMITTED THROUGH FERTILIZATION, THEY WOULD ALTER THE CRITICAL GENE EXPRESSION DOSAGES REQUIRED FOR NORMAL PRENATAL DEVELOPMENT RESULTING IN OFFSPRING WITH FEATURES OF FASD. 2009 4 2539 32 EPIGENETICS IN HYPERHOMOCYSTEINEMIC STATES. A SPECIAL FOCUS ON UREMIA. AIM OF THIS ARTICLE IS TO REVIEW THE TOPIC OF EPIGENETIC CONTROL OF GENE EXPRESSION, ESPECIALLY REGARDING DNA METHYLATION, IN CHRONIC KIDNEY DISEASE AND UREMIA. HYPERHOMOCYSTEINEMIA IS CONSIDERED AN INDEPENDENT CARDIOVASCULAR RISK FACTOR, ALTHOUGH THE MOST RECENT INTERVENTION STUDIES UTILIZING FOLIC ACID ARE NEGATIVE. THE ACCUMULATION OF HOMOCYSTEINE IN BLOOD LEADS TO AN INTRACELLULAR INCREASE OF S-ADENOSYLHOMOCYSTEINE (ADOHCY), A POWERFUL COMPETITIVE METHYLTRANSFERASE INHIBITOR, WHICH IS ITSELF CONSIDERED A PREDICTOR OF CARDIOVASCULAR EVENTS. THE EXTENT OF METHYLATION INHIBITION OF EACH INDIVIDUAL METHYLTRANSFERASE DEPENDS ON THE METHYL DONOR S-ADENOSYLMETHIONINE (ADOMET) AVAILABILITY, ON THE [ADOMET]/[ADOHCY] RATIO, AND ON THE INDIVIDUAL KM VALUE FOR ADOMET AND KI FOR ADOHCY. DNA METHYLTRANSFERASES ARE AMONG THE PRINCIPAL TARGETS OF HYPERHOMOCYSTEINEMIA, AS STUDIES IN SEVERAL CELL CULTURE AND ANIMAL MODELS, AS WELL AS IN HUMANS, ALMOST UNEQUIVOCALLY SHOW. IN VIVO, DNA METHYLATION MAY BE ALSO INFLUENCED BY VARIOUS FACTORS IN DIFFERENT TISSUES, FOR EXAMPLE BY RATE OF CELL GROWTH, FOLATE STATUS, ETC. AND IMPORTANTLY INFLAMMATION. IN CHRONIC KIDNEY DISEASE AND IN UREMIA, HYPERHOMOCYSTEINEMIA IS COMMONLY SEEN, AND CAN BE ASSOCIATED WITH GLOBAL DNA HYPOMETHYLATION, AND WITH ABNORMAL ALLELIC EXPRESSION OF GENES REGULATED THROUGH METHYLATION. THIS ALTERATION IS SUSCEPTIBLE OF REVERSAL UPON HOMOCYSTEINE-LOWERING THERAPY OBTAINED THROUGH FOLATE ADMINISTRATION. IF THIS ABNORMALITY WILL TRANSLATE ITSELF IN ALTERATIONS OF EXPRESSION OF GENES RELEVANT TO THE PATHOGENESIS OF THIS DISEASE STILL REMAINS TO BE ESTABLISHED. IN ADDITION, THESE RESULTS ESTABLISH A LINK BETWEEN THE EPIGENETIC CONTROL OF GENE EXPRESSION AND XENOBIOTIC INFLUENCES, SUCH AS FOLATE THERAPY. 2009 5 745 53 CANNABIS ALTERS EPIGENETIC INTEGRITY AND ENDOCANNABINOID SIGNALLING IN THE HUMAN FOLLICULAR NICHE. STUDY QUESTION: DO PHYTOCANNABINOIDS (PCS) AFFECT FOLLICULAR ENDOCANNABINOID SIGNALLING AND THE EPIGENOME IN THE SURROUNDING GRANULOSA CELLS (GCS)? SUMMARY ANSWER: EXPOSURE TO PCS INCREASES THE EXPRESSION OF ENDOCANNABINOID RECEPTORS AND REDUCES DNA METHYLATION ENZYME EXPRESSION AND GLOBAL DNA METHYLATION IN NAIVE GCS. WHAT IS KNOWN ALREADY: CANNABIS PLANT DERIVATIVES, KNOWN AS PCS, ARE USED FOR MEDICINAL AND RECREATIONAL PURPOSES. THE MAIN PC, TETRAHYDROCANNABINOL (THC), IS THE THIRD MOST COMMONLY USED SUBSTANCE BY WOMEN OF CHILDBEARING AGE, HENCE KNOWLEDGE OF THE EFFECT IT HAS ON REPRODUCTION IS OF UTMOST IMPORTANCE. THC EXERTS ITS EFFECTS VIA RECEPTORS OF THE ENDOCANNABINOID SYSTEM (ECS) AND CAN INTERFERE WITH FOLLICULOGENESIS, OOCYTE DEVELOPMENT AND OVULATION. ENDOCANNABINOIDS HAVE BEEN MEASURED IN FOLLICULAR FLUID (FF) OBTAINED DURING OOCYTE RETRIEVAL AND ARE IMPLICATED IN CONTROLLING FOLLICULOGENESIS. IT HAS BEEN ESTABLISHED THAT IN THE PLACENTA, PCS DISRUPT ENDOCANNABINOID HOMEOSTASIS VIA IMPAIRMENT OF THE SYNTHETIC AND DEGRADING ENZYMES, LEADING TO A NET INCREASE OF ENDOCANNABINOID LEVELS. FINALLY, PREVIOUS STUDIES HAVE SHOWN THAT THC ALTERS METHYLATION AND HISTONE MODIFICATIONS IN SPERM, BRAIN AND BLOOD CELLS. STUDY DESIGN, SIZE, DURATION: THIS STUDY INCLUDED AN IN VIVO COHORT ASSESSMENT OF CANNABIS EXPOSURE AND ITS EFFECTS ON THE FOLLICLE AND IN VITRO ASSAYS CONDUCTED TO VALIDATE THE IN VIVO FINDINGS AND TO EXPLORE POSSIBLE MECHANISMS OF ACTION. PARTICIPANTS/MATERIALS, SETTING, METHODS: A TOTAL OF 318 FF SAMPLES, FROM 261 PATIENTS UNDERGOING IVF TREATMENT AT A PRIVATE FERTILITY CLINIC WHO CONSENTED FOR BIOBANKING BIOLOGICAL WASTE MATERIAL BETWEEN JANUARY 2018 AND JULY 2019, WERE INCLUDED IN THIS STUDY. CONCENTRATIONS OF PCS AND ENDOCANNABINOIDS WERE ASSESSED IN FF BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY (LC-MS/MS). EXPOSURE TO PCS WAS DETERMINED BASED ON THESE MEASURED LEVELS. LEVELS OF BOTH ENDOCANNABINOID RECEPTORS (CB1R, CB2R) AND THE DE NOVO DNA METHYLATING ENZYME, DNMT3B, IN GCS WERE ASSESSED BY FLOW CYTOMETRY BOTH IN VITRO AND IN VIVO AND GLOBAL DNA METHYLATION WAS ASSESSED IN VITRO BY ELISA. IN VIVO EFFECTS WERE ASSESSED BY COMPARING SAMPLES POSITIVE FOR AT LEAST ONE PC, WITH SAMPLES NEGATIVE FOR ALL MEASURED PCS. IN VITRO EFFECTS WERE DETERMINED IN NAIVE GCS, OBTAINED CONCURRENTLY WITH FF SAMPLES THAT HAD TESTED NEGATIVE FOR ALL PCS. THESE GCS WERE TREATED WITH DIFFERENT COMBINATIONS OF THE MAIN THREE PCS. MAIN RESULTS AND THE ROLE OF CHANCE: OVERALL, 17 PATIENTS (6.4%) WERE POSITIVE FOR CANNABIS CONSUMPTION. FURTHERMORE, THE PREVALENCE OF CANNABIS POSITIVITY IN THE FF INCREASED FROM 4% OF THE TESTED SAMPLES THAT WERE COLLECTED PRIOR TO NATIONAL LEGALISATION IN OCTOBER 2018 TO 12% OF THOSE COLLECTED FOLLOWING LEGALISATION. OF NOTE, 59% OF PATIENTS WHO TESTED POSITIVE FOR PCS (10 OF 17) REPORTED PREVIOUS OR ONGOING EXPOSURE TO CANNABIS UPON THEIR INITIAL INTAKE. ENDOCANNABINOID LEVELS WERE NOT AFFECTED BY THE PRESENCE OF PCS. CB2R WAS MORE PREVALENT THAN CB1R IN GCS AND ITS EXPRESSION INCREASED FOLLOWING ACUTE AND CHRONIC IN VITRO EXPOSURE TO PCS. THE EXPRESSION OF DNMT3B AND GLOBAL METHYLATION DECREASED FOLLOWING EXPOSURE, SUGGESTING THAT CANNABIS MAY AFFECT THE EPIGENOME IN THE FOLLICULAR NICHE. THE ACUTE CHANGES WERE SUSTAINED THROUGHOUT CHRONIC TREATMENT. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: OUR STUDY IS LIMITED BY LACK OF DETAILS REGARDING MODE, FREQUENCY AND TIMING OF PC CONSUMPTION. MOREOVER, WE WERE NOT ABLE TO ADEQUATELY ASSESS THE EFFECT OF PCS ON IMMEDIATE OR LONG-TERM CLINICAL OUTCOMES, DUE TO THE SMALL SAMPLE SIZE AND THE LACK OF FOLLOW UP. FUTURE, LARGE-SCALE STUDIES SHOULD FOCUS ON ASSESS THE CLINICAL IMPLICATIONS OF CANNABIS EXPOSURE, VALIDATE OUR FINDINGS, AND DETERMINE TO WHAT EXTENT CANNABIS AFFECTS THE EPIGENOME OVARIAN FOLLICLE AND THE DEVELOPING OOCYTE. WIDER IMPLICATIONS OF THE FINDINGS: TO OUR KNOWLEDGE, THIS IS THE FIRST STUDY MEASURING PCS IN FF BY LC-MS/MS. WE SHOW THAT CONSUMING CANNABIS ALTERS THE ECS IN THE DEVELOPING FOLLICLE, AND DIRECTLY AFFECTS DNMT EXPRESSION AND GLOBAL DNA METHYLATION LEVELS. CANNABIS LEGALISATION AND USE IS INCREASING WORLDWIDE, THEREFORE FURTHER UNDERSTANDING ITS ROLE IN FEMALE FERTILITY AND FOLLICULOGENESIS IS CRITICAL. STUDY FUNDING/COMPETING INTEREST(S): ALL FUNDING WAS PROVIDED BY CREATE FERTILITY CENTRE THROUGH THE REINVESTMENT OF CLINICAL EARNINGS. THE AUTHORS DECLARE NO COMPETING INTERESTS. 2021 6 1140 29 CONCENTRATION OF FOLIC ACID (FA) IN SERUM OF JAPANESE PREGNANT WOMEN. OBJECTIVES EXPOSURE TO INORGANIC ARSENIC (IAS) IS A WORLD-WIDE HEALTH CONCERN. WE REPORTED THAT JAPANESE CHILDREN AND PREGNANT WOMEN ARE EXPOSED TO MODERATE LEVELS OF IAS THROUGH FOOD. REDUCING IAS CONTAMINATION FROM FOODS OF HIGH IAS IS AN IMPORTANT ISSUE UNIQUE IN JAPAN. INTEGRATED IAS IS METHYLATED TO LESS TOXIC ORGANIC FORMS, AND S-ADENOSYL-L-METHYONINE (SAM), A COMMON METHYL-DONOR OF DNA AND HISTONES, IS UTILIZED IN THIS PROCESS. CHRONIC CONSUMPTION OF SAM BY IAS METABOLISM DUE TO EXPOSURE TO IAS MIGHT ALTER THE EPIGENETIC MODIFICATION OF GENOME. THE SAM BIOSYNTHESIS PATHWAY IS DEPENDENT ON FOLATE CYCLE, AND IT IS POSSIBLE THAT INGESTION OF SUFFICIENT FOLIC ACID (FA) IS PROTECTIVE TO IAS INDUCED TOXICITY. METHODS IN THE COURSE OF OUR CROSS-SECTIONAL BODY BURDEN ANALYSES OF PB AND IAS IN JAPANESE CHILDREN AND PREGNANT WOMEN, TERMED "PBAS STUDY", FA CONCENTRATION IN SERUM OF 104 PREGNANT WOMEN WAS MEASURED. RESULTS MEAN (+/-SEM) OF SERUM FA CONCENTRATION WAS 15.8 +/- 1.3 (NG/ML). THERE ARE SIGNIFICANT NUMBER OF PEOPLE SHOWING VERY HIGH FA (>30 NG/ ML), AND LARGE FRACTION OF THEM WERE TAKING SUPPLEMENTS DAILY. CONCLUSIONS THESE RESULTS SUGGESTED THAT LEVEL OF FA INGESTION OF JAPANESE PREGNANT WOMEN IS HIGH FOR SUPPORTING NORMAL FETAL DEVELOPMENT. 2020 7 521 42 ASSOCIATIONS BETWEEN MATERNAL PSYCHOSOCIAL STRESS, DNA METHYLATION, AND NEWBORN BIRTH WEIGHT IDENTIFIED BY INVESTIGATING METHYLATION AT INDIVIDUAL, REGIONAL, AND GENOME LEVELS. STRESS IS KNOWN TO AFFECT HEALTH THROUGHOUT LIFE AND INTO FUTURE GENERATIONS, BUT THE UNDERLYING MOLECULAR MECHANISMS ARE UNKNOWN. WE TESTED THE HYPOTHESIS THAT MATERNAL PSYCHOSOCIAL STRESS INFLUENCES DNA METHYLATION (DNAM), WHICH IN TURN IMPACTS NEWBORN HEALTH OUTCOMES. SPECIFICALLY, WE ANALYZED DNAM AT INDIVIDUAL, REGIONAL, AND GENOME-WIDE LEVELS TO TEST FOR ASSOCIATIONS WITH MATERNAL STRESS AND NEWBORN BIRTH WEIGHT. MATERNAL VENOUS BLOOD AND NEWBORN CORD BLOOD (N = 24 AND 22, RESPECTIVELY) WERE ASSAYED FOR METHYLATION AT APPROXIMATELY 450,000 CPG SITES. METHYLATION WAS ANALYZED BY EXAMINING CPG SITES INDIVIDUALLY IN AN EPIGENOME-WIDE ASSOCIATION STUDY (EWAS), AS REGIONAL GROUPS USING VARIABLY METHYLATED REGION (VMR) ANALYSIS IN MATERNAL BLOOD ONLY, AND THROUGH THE EPIGENOME-WIDE MEASURES USING GENOME-WIDE MEAN METHYLATION (GMM), HORVATH'S EPIGENETIC CLOCK, AND MITOTIC AGE. THESE METHYLATION MEASURES WERE TESTED FOR ASSOCIATION WITH THREE MEASURES OF MATERNAL STRESS (MATERNAL WAR TRAUMA, CHRONIC STRESS, AND EXPERIENCE OF SEXUAL VIOLENCE) AND ONE HEALTH OUTCOME (NEWBORN BIRTH WEIGHT). WE OBSERVED THAT MATERNAL EXPERIENCES OF WAR TRAUMA, CHRONIC STRESS, AND SEXUAL ASSAULT WERE EACH ASSOCIATED WITH DECREASED NEWBORN BIRTH WEIGHT (P < 1.95 X 10(-7) IN ALL CASES). TESTING INDIVIDUAL CPG SITES USING EWAS, WE OBSERVED NO ASSOCIATIONS BETWEEN DNAM AND ANY MEASURE OF MATERNAL STRESS OR NEWBORN BIRTH WEIGHT IN EITHER MATERNAL OR CORD BLOOD, AFTER BONFERRONI MULTIPLE TESTING CORRECTION. HOWEVER, THE TOP-RANKED CPG SITE IN MATERNAL BLOOD THAT ASSOCIATED WITH MATERNAL CHRONIC STRESS AND SEXUAL VIOLENCE BEFORE MULTIPLE TESTING CORRECTION IS LOCATED NEAR THE SPON1 GENE. TESTING AT A REGIONAL LEVEL, WE FOUND INCREASED METHYLATION OF A VMR IN MATERNAL BLOOD NEAR SPON1 THAT WAS ASSOCIATED WITH CHRONIC STRESS AND SEXUAL VIOLENCE AFTER BONFERRONI MULTIPLE TESTING CORRECTION (P = 1.95 X 10(-7) AND 8.3 X 10(-6), RESPECTIVELY). AT THE EPIGENOMIC LEVEL, CORD BLOOD GMM WAS ASSOCIATED WITH SIGNIFICANTLY HIGHER LEVELS OF WAR TRAUMA (P = 0.025) AND WAS SUGGESTIVELY ASSOCIATED WITH SEXUAL VIOLENCE (P = 0.053). THE OTHER TWO EPIGENOME-WIDE MEASURES WERE NOT ASSOCIATED WITH MATERNAL STRESS OR NEWBORN BIRTH WEIGHT IN EITHER TISSUE TYPE. DESPITE OUR SMALL SAMPLE SIZE, WE IDENTIFIED ASSOCIATIONS EVEN AFTER CONSERVATIVE MULTIPLE TESTING CORRECTION. SPECIFICALLY, WE FOUND ASSOCIATIONS BETWEEN DNAM AND THE THREE MEASURES OF MATERNAL STRESS ACROSS BOTH TISSUES; SPECIFICALLY, A VMR IN MATERNAL BLOOD AND GMM IN CORD BLOOD WERE BOTH ASSOCIATED WITH DIFFERENT MEASURES OF MATERNAL STRESS. THE ASSOCIATION OF CORD BLOOD GMM, BUT NOT MATERNAL BLOOD GMM, WITH MATERNAL STRESS MAY SUGGEST DIFFERENT RESPONSES TO STRESS IN MOTHER AND NEWBORN. IT IS NOTEWORTHY THAT WE FOUND ASSOCIATIONS ONLY WHEN CPG SITES WERE ANALYZED IN AGGREGATE, EITHER AS VMRS OR AS A BROAD SUMMARY MEASURE OF GMM. 2019 8 502 35 ASSOCIATION OF ARSENIC EXPOSURE WITH WHOLE BLOOD DNA METHYLATION: AN EPIGENOME-WIDE STUDY OF BANGLADESHI ADULTS. BACKGROUND: ARSENIC EXPOSURE AFFECTS [FORMULA: SEE TEXT] PEOPLE WORLDWIDE, INCLUDING [FORMULA: SEE TEXT] IN BANGLADESH. ARSENIC EXPOSURE INCREASES THE RISK OF CANCER AND OTHER CHRONIC DISEASES, AND ONE POTENTIAL MECHANISM OF ARSENIC TOXICITY IS EPIGENETIC DYSREGULATION. OBJECTIVE: WE ASSESSED ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND GENOME-WIDE DNA METHYLATION MEASURED AT BASELINE AMONG 396 BANGLADESHI ADULTS PARTICIPATING IN THE HEALTH EFFECTS OF ARSENIC LONGITUDINAL STUDY (HEALS) WHO WERE EXPOSED BY DRINKING NATURALLY CONTAMINATED WELL WATER. METHODS: METHYLATION IN WHOLE BLOOD DNA WAS MEASURED AT [FORMULA: SEE TEXT] USING THE ILLUMINA INFINIUMMETHYLATIONEPIC (EPIC) ARRAY. TO ASSESS ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND CPG METHYLATION, WE USED LINEAR REGRESSION MODELS ADJUSTED FOR COVARIATES AND SURROGATE VARIABLES (SVS) (CAPTURING UNKNOWN TECHNICAL AND BIOLOGIC FACTORS). WE ATTEMPTED REPLICATION AND CONDUCTED A META-ANALYSIS USING AN INDEPENDENT DATASET OF [FORMULA: SEE TEXT] FROM 400 BANGLADESHI INDIVIDUALS WITH ARSENICAL SKIN LESIONS. RESULTS: WE IDENTIFIED 34 CPGS ASSOCIATED WITH [FORMULA: SEE TEXT] CREATININE-ADJUSTED URINARY ARSENIC [[FORMULA: SEE TEXT]]. SIXTEEN OF THESE CPGS ANNOTATED TO THE [FORMULA: SEE TEXT] ARRAY, AND 10 ASSOCIATIONS WERE REPLICATED ([FORMULA: SEE TEXT]). THE TOP TWO CPGS ANNOTATED UPSTREAM OF THE ABR GENE (CG01912040, CG10003262 ). ALL URINARY ARSENIC-ASSOCIATED CPGS WERE ALSO ASSOCIATED WITH ARSENIC CONCENTRATION MEASURED IN DRINKING WATER ([FORMULA: SEE TEXT]). META-ANALYSIS ([FORMULA: SEE TEXT] SAMPLES) IDENTIFIED 221 URINARY ARSENIC-ASSOCIATED CPGS ([FORMULA: SEE TEXT]). THE ARSENIC-ASSOCIATED CPGS FROM THE META-ANALYSIS WERE ENRICHED IN NON-CPG ISLANDS AND SHORES ([FORMULA: SEE TEXT]) AND DEPLETED IN PROMOTER REGIONS ([FORMULA: SEE TEXT]). AMONG THE ARSENIC-ASSOCIATED CPGS ([FORMULA: SEE TEXT]), WE OBSERVED SIGNIFICANT ENRICHMENT OF GENES ANNOTATING TO THE REACTIVE OXYGEN SPECIES PATHWAY, INFLAMMATORY RESPONSE, AND TUMOR NECROSIS FACTOR [FORMULA: SEE TEXT] ([FORMULA: SEE TEXT]) SIGNALING VIA NUCLEAR FACTOR KAPPA-B ([FORMULA: SEE TEXT]) HALLMARKS ([FORMULA: SEE TEXT]). CONCLUSIONS: THE NOVEL AND REPLICABLE ASSOCIATIONS BETWEEN ARSENIC EXPOSURE AND DNA METHYLATION AT SPECIFIC CPGS OBSERVED IN THIS WORK SUGGEST THAT EPIGENETIC ALTERATIONS SHOULD BE FURTHER INVESTIGATED AS POTENTIAL MEDIATORS IN ARSENIC TOXICITY AND AS BIOMARKERS OF EXPOSURE AND EFFECT IN EXPOSED POPULATIONS. HTTPS://DOI.ORG/10.1289/EHP3849. 2019 9 3304 45 HIGH-GLUCOSE CONCENTRATIONS CHANGE DNA METHYLATION LEVELS IN HUMAN IVM OOCYTES. STUDY QUESTION: WHAT ARE THE EFFECTS OF HIGH-GLUCOSE CONCENTRATIONS ON DNA METHYLATION OF HUMAN OOCYTES? SUMMARY ANSWER: HIGH-GLUCOSE CONCENTRATIONS ALTERED DNA METHYLATION LEVELS OF PEG3 AND ADIPONECTIN IN HUMAN IN VITRO MATURATION OOCYTES. WHAT IS KNOWN ALREADY: MATERNAL DIABETES HAS A DETRIMENTAL INFLUENCE ON OOCYTE QUALITY INCLUDING EPIGENETIC MODIFICATIONS, AS SHOWN IN NON-HUMAN MAMMALIAN SPECIES. STUDY DESIGN, SIZE, DURATION: IMMATURE METAPHASE I (MI) STAGE OOCYTES OF GOOD QUALITY WERE RETRIEVED FROM PATIENTS WHO HAD NORMAL OVARIAN POTENTIAL AND WHO UNDERWENT ICSI IN THE REPRODUCTIVE MEDICINE CENTER OF PEOPLE'S HOSPITAL OF ZHENGZHOU UNIVERSITY. MI OOCYTES WERE CULTURED IN MEDIUM WITH DIFFERENT GLUCOSE CONCENTRATIONS (CONTROL, 10 MM AND 15 MM) IN VITRO AND 48 H LATER, OOCYTES WITH FIRST POLAR BODY EXTRUSION WERE COLLECTED TO CHECK THE DNA METHYLATION LEVELS. PARTICIPANTS/MATERIALS, SETTING, METHODS: MI OOCYTES UNDERWENT IN VITRO MATURATION (IVM) AT 37 DEGREES C WITH 5% MIXED GAS FOR 48 H. THEN THE MATURE OOCYTES WERE TREATED WITH BISULFITE BUFFER. TARGET SEQUENCES WERE AMPLIFIED USING NESTED OR HALF-NESTED PCR AND THE DNA METHYLATION STATUS WAS TESTED USING COMBINED BISULFITE RESTRICTION ANALYSIS (COBRA) AND BISULFITE SEQUENCING (BS). MAIN RESULTS AND THE ROLE OF CHANCE: HIGH-GLUCOSE CONCENTRATIONS SIGNIFICANTLY DECREASED THE FIRST POLAR BODY EXTRUSION RATE. COMPARED TO CONTROLS, THE DNA METHYLATION LEVELS OF PEG3 IN HUMAN IVM OOCYTES WERE SIGNIFICANTLY HIGHER IN 10 MM (P < 0.001) AND 15 MM (P < 0.001) CONCENTRATIONS OF GLUCOSE. BUT THE DNA METHYLATION LEVEL OF H19 WAS NOT AFFECTED BY HIGH-GLUCOSE CONCENTRATIONS IN HUMAN IVM OOCYTES. WE ALSO FOUND THAT THERE WAS A DECREASE IN DNA METHYLATION LEVELS IN THE PROMOTER OF ADIPONECTIN IN HUMAN IVM OOCYTES BETWEEN CONTROLS AND OOCYTES EXPOSED TO 10 MM GLUCOSE (P = 0.028). LARGE SCALE DATA: N/A. LIMITATIONS REASONS FOR CAUTION: IT IS NOT CLEAR WHETHER THE ALTERATIONS ARE BENEFICIAL OR NOT FOR THE EMBRYO DEVELOPMENT AND OFFSPRING HEALTH. THE EFFECTS OF HIGH-GLUCOSE CONCENTRATIONS ON THE WHOLE PROCESS OF OOCYTE MATURATION ARE STILL NOT ELUCIDATED. ANOTHER ISSUE IS THAT THE NUMBER OF OOCYTES USED IN THIS STUDY WAS LIMITED. WIDER IMPLICATIONS OF THE FINDINGS: THIS IS THE FIRST TIME THAT THE EFFECTS OF HIGH-GLUCOSE CONCENTRATION ON DNA METHYLATION OF HUMAN OOCYTES HAVE BEEN ELUCIDATED. OUR RESULT INDICATES THAT IN HUMANS, THE HIGH RISK OF CHRONIC DISEASES IN OFFSPRING FROM DIABETIC MOTHERS MAY ORIGINATE FROM ABNORMAL DNA MODIFICATIONS IN OOCYTES. STUDY FUNDING/COMPETING INTEREST(S): THIS WORK WAS SUPPORTED BY THE FUND OF NATIONAL NATURAL SCIENCE FOUNDATION OF CHINA (81401198) AND DOCTOR FOUNDATION OF QINGDAO AGRICULTURAL UNIVERSITY (1116008).THE AUTHORS DECLARE THAT THERE ARE NO POTENTIAL CONFLICTS OF INTEREST RELEVANT TO THIS ARTICLE. 2018 10 5093 50 PLACENTAS FROM PREGNANCIES CONCEIVED BY IVF/ICSI HAVE A REDUCED DNA METHYLATION LEVEL AT THE H19 AND MEST DIFFERENTIALLY METHYLATED REGIONS. STUDY QUESTION: DOES IVF/ICSI HAVE AN EFFECT ON THE EPIGENETIC REGULATION OF THE HUMAN PLACENTA? SUMMARY ANSWER: WE FOUND A REDUCED DNA METHYLATION LEVEL AT THE H19 AND MEST DIFFERENTIALLY METHYLATED REGIONS (DMRS), AND AN INCREASED RNA EXPRESSION OF H19 IN PLACENTAS FROM PREGNANCIES CONCEIVED BY IVF/ICSI WHEN COMPARED WITH PLACENTAS FROM SPONTANEOUS CONCEPTION. WHAT IS KNOWN ALREADY: CHANGES IN FETAL ENVIRONMENT ARE ASSOCIATED WITH ADVERSE HEALTH OUTCOMES. THE PLACENTA IS PIVOTAL FOR INTRAUTERINE ENVIRONMENT. ANIMAL STUDIES SHOW THAT EPIGENETIC REGULATION PLAYS AN IMPORTANT ROLE IN THESE ENVIRONMENT-INDUCED PHENOTYPIC EFFECTS. ALSO, THE PREIMPLANTATION EMBRYO ENVIRONMENT AFFECTS BIRTHWEIGHT AS WELL AS THE RISK OF CHRONIC ADULT DISEASES. EPIGENETIC PROCESSES ARE SENSITIVE TO THE ENVIRONMENT, ESPECIALLY DURING THE PERIOD AROUND CONCEPTION. STUDY DESIGN AND PARTICIPANTS: PLACENTAL TISSUE WAS COLLECTED FROM 35 SPONTANEOUSLY CONCEIVED PREGNANCIES AND 35 IVF/ICSI (5 IVF, 30 ICSI) DERIVED PREGNANCIES. WE QUANTITATIVELY ANALYSED THE DNA METHYLATION PATTERNS OF A NUMBER OF CONSECUTIVE CPGS IN THE CORE REGIONS OF DMRS AND OTHER REGULATORY REGIONS OF IMPRINTED GENES, SINCE THESE ARE INVOLVED IN PLACENTAL AND FETAL GROWTH AND DEVELOPMENT. METHODS: BY USING PYROSEQUENCING, THE DNA METHYLATION AT SEVEN GERMLINE-DERIVED PRIMARY DMRS WAS ANALYSED QUANTITATIVELY. FIVE OF THESE ARE MATERNALLY METHYLATED (MEST ISOFORM ALPHA AND BETA, PEG3, KCNQ1OT1 AND SNRPN) AND TWO ARE PATERNALLY METHYLATED [H19 DMR AND THE INTERGENIC REGION BETWEEN DLK1 AND MEG3 (IG-DMR)]. THE POST-FERTILIZATION-DERIVED SECONDARY DMRS, IGF2 (DMR0 AND 2) AND IG-DMR (CG7, ALSO CALLED MEG3 DMR), AND THE MEG3 PROMOTER REGION WERE EXAMINED AS WELL. IN CASE OF DIFFERENTIAL METHYLATION BETWEEN THE TWO GROUPS, THE EFFECT ON GENE EXPRESSION WAS ASSESSED BY QUANTITATIVE REAL-TIME PCR. MAIN RESULTS AND THE ROLE OF CHANCE: BOTH THE PROMOTER REGION OF MEST ISOFORM ALPHA AND BETA AND THE 6TH CTCF BINDING SITE WITHIN THE H19 DMR WERE SIGNIFICANTLY HYPOMETHYLATED IN THE IVF/ICSI GROUP. THE PHENOMENON WAS CONSISTENTLY OBSERVED OVER ALL CPG SITES ANALYSED AND NOT RESTRICTED TO SINGLE CPG SITES. THE OTHER PRIMARY AND SECONDARY DMRS WERE NOT AFFECTED. EXPRESSION OF H19 WAS INCREASED IN THE IVF/ICSI GROUP, WHILE THAT OF IGF2 AND MEST REMAINED SIMILAR. LIMITATIONS, REASONS FOR CAUTION: IN THE IVF/ICSI GROUP, MOSTLY ICSI PREGNANCIES WERE INVESTIGATED. THE ICSI TECHNIQUE OR MALE SUBFERTILITY COULD BE A CONFOUNDING FACTOR. THEREFORE, OUR RESULTS ARE LESS GENERALIZABLE TO IVF PREGNANCIES. WIDER IMPLICATIONS OF THE FINDINGS: THE CLINICAL EFFECTS OF THE OBSERVED PLACENTAL HYPOMETHYLATIONS ON THE DEVELOPMENTAL PROGRAMMING OF THE IVF/ICSI PROGENY, IF ANY, ARE AS YET UNKNOWN. WHETHER THE HYPOMETHYLATION IS AN ADAPTATION OF THE PLACENTA TO MAINTAIN FETAL SUPPLY AND AMELIORATE THE EFFECTS OF ENVIRONMENTAL CUES, OR WHETHER IT IS A DEREGULATION LEADING TO DERANGED DEVELOPMENTAL PROGRAMMING WITH OR WITHOUT INCREASED VULNERABILITY FOR DISEASE, CONSISTENT WITH THE DEVELOPMENTAL ORIGINS OF HEALTH AND DISEASE HYPOTHESIS, NEEDS FURTHER INVESTIGATION. STUDY FUNDING/COMPETING INTEREST(S): PARTLY FUNDED BY AN UNRESTRICTED RESEARCH GRANT BY ORGANON BV (NOW MSD BV) WITHOUT ANY ROLE IN STUDY DESIGN, DATA COLLECTION AND ANALYSIS, OR PREPARATION OF THE MANUSCRIPT. NO CONFLICT OF INTERESTS TO DECLARE. TRIAL REGISTRATION NUMBER: DUTCH TRIAL REGISTRY (NTR) NUMBER 1298. 2013 11 4010 25 LOW MATERNAL ADHERENCE TO A MEDITERRANEAN DIET IS ASSOCIATED WITH INCREASE IN METHYLATION AT THE MEG3-IG DIFFERENTIALLY METHYLATED REGION IN FEMALE INFANTS. DIET IS DICTATED BY THE SURROUNDING ENVIRONMENT, AS FOOD ACCESS AND AVAILABILITY MAY CHANGE DEPENDING ON WHERE ONE LIVES. MATERNAL DIET DURING PREGNANCY IS AN IMPORTANT PART OF THE IN UTERO ENVIRONMENT, AND MAY AFFECT THE EPIGENOME. STUDIES LOOKING AT OVERALL DIET PATTERN IN RELATION TO DNA METHYLATION HAVE BEEN LACKING. THE MEDITERRANEAN DIET IS KNOWN FOR ITS HEALTH BENEFITS, INCLUDING DECREASED INFLAMMATION, WEIGHT LOSS, AND MANAGEMENT OF CHRONIC DISEASES. THIS STUDY ASSESSES THE ASSOCIATION BETWEEN MATERNAL ADHERENCE TO A MEDITERRANEAN DIET PATTERN DURING PREGNANCY AND INFANT DNA METHYLATION AT BIRTH. MEDITERRANEAN DIET ADHERENCE IN EARLY PREGNANCY WAS MEASURED IN 390 WOMEN ENROLLED IN THE NEWBORN EPIGENETIC STUDY, AND DNA METHYLATION WAS ASSESSED IN THEIR INFANTS AT BIRTH. MULTINOMIAL LOGISTIC REGRESSION WAS USED TO ASSESS THE ASSOCIATION BETWEEN ADHERENCE TO A MEDITERRANEAN DIET AND INFANT METHYLATION AT THE MEG3, MEG3-IG, PLEIOMORPHIC ADENOMA GENE-LIKE 1, INSULIN-LIKE GROWTH FACTOR 2 GENE, H19, MESODERM-SPECIFIC TRANSCRIPT, NEURONATIN, PATERNALLY EXPRESSED GENE 3, SARCOGLYCAN AND PATERNALLY EXPRESSED GENE 10 REGIONS, MEASURED BY PYROSEQUENCING. INFANTS OF MOTHERS WITH A LOW ADHERENCE TO A MEDITERRANEAN DIET HAD A GREATER ODDS OF HYPO-METHYLATION AT THE MEG3-IG DIFFERENTIALLY METHYLATED REGION (DMR). SEX-STRATIFIED MODELS SHOWED THAT THIS ASSOCIATION WAS PRESENT IN GIRLS ONLY. THIS STUDY PROVIDES EARLY EVIDENCE ON THE ASSOCIATION BETWEEN OVERALL DIET PATTERN AND METHYLATION AT THE 9 DMRS INCLUDED IN THIS STUDY, AND SUGGESTS THAT MATERNAL DIET CAN HAVE A SEX-SPECIFIC IMPACT ON INFANT DNA METHYLATION AT SPECIFIC IMPRINTED DMRS. 2017 12 518 37 ASSOCIATIONS BETWEEN ANTIBIOTIC EXPOSURE DURING PREGNANCY, BIRTH WEIGHT AND ABERRANT METHYLATION AT IMPRINTED GENES AMONG OFFSPRING. OBJECTIVES: LOW BIRTH WEIGHT (LBW) HAS BEEN ASSOCIATED WITH COMMON ADULT-ONSET CHRONIC DISEASES, INCLUDING OBESITY, CARDIOVASCULAR DISEASE, TYPE II DIABETES AND SOME CANCERS. THE ETIOLOGY OF LBW IS MULTI-FACTORIAL. HOWEVER, RECENT EVIDENCE SUGGESTS EXPOSURE TO ANTIBIOTICS MAY ALSO INCREASE THE RISK OF LBW. THE MECHANISMS UNDERLYING THIS ASSOCIATION ARE UNKNOWN, ALTHOUGH EPIGENETIC MECHANISMS ARE HYPOTHESIZED. IN THIS STUDY, WE EVALUATED THE ASSOCIATION BETWEEN MATERNAL ANTIBIOTIC USE AND LBW AND EXAMINED THE POTENTIAL ROLE OF ALTERED DNA METHYLATION THAT CONTROLS GROWTH REGULATORY IMPRINTED GENES IN THESE ASSOCIATIONS. METHODS: BETWEEN 2009-2011, 397 PREGNANT WOMEN WERE ENROLLED AND FOLLOWED UNTIL DELIVERY. PRENATAL ANTIBIOTIC USE WAS ASCERTAINED THROUGH MATERNAL SELF-REPORT. IMPRINTED GENES METHYLATION LEVELS WERE MEASURED AT DIFFERENTIALLY METHYLATED REGIONS (DMRS) USING BISULFITE PYROSEQUENCING. GENERALIZED LINEAR MODELS WERE USED TO EXAMINE ASSOCIATIONS AMONG ANTIBIOTIC USE, BIRTH WEIGHT AND DMR METHYLATION FRACTIONS. RESULTS: AFTER ADJUSTING FOR INFANT GENDER, RACE/ETHNICITY, MATERNAL BODY MASS INDEX, DELIVERY ROUTE, GESTATIONAL WEIGHT GAIN, GESTATIONAL AGE AT DELIVERY, FOLIC ACID INTAKE, PHYSICAL ACTIVITY, MATERNAL SMOKING AND PARITY, ANTIBIOTIC USE DURING PREGNANCY WAS ASSOCIATED WITH 138 G LOWER BIRTH WEIGHT COMPARED WITH NON-ANTIBIOTIC USE (BETA-COEFFICIENT=-132.99, S.E.=50.70, P=0.008). THESE ASSOCIATIONS WERE STRONGEST IN NEWBORNS OF WOMEN WHO REPORTED ANTIBIOTIC USE OTHER THAN PENICILLINS (BETA-COEFFICIENT=-135.57, S.E.=57.38, P=0.02). METHYLATION AT FIVE DMRS, IGF2 (P=0.05), H19 (P=0.15), PLAGL1 (P=0.01), MEG3 (P=0.006) AND PEG3 (P=0.08), WAS ASSOCIATED WITH MATERNAL ANTIBIOTIC USE; AMONG THESE, ONLY METHYLATION AT THE PLAGL1 DMR WAS ALSO ASSOCIATED WITH BIRTH WEIGHT. CONCLUSION: WE REPORT AN INVERSE ASSOCIATION BETWEEN IN UTERO EXPOSURE TO ANTIBIOTICS AND LOWER INFANT BIRTH WEIGHT AND PROVIDE THE FIRST EMPIRICAL EVIDENCE SUPPORTING IMPRINTED GENE PLASTICITY IN THESE ASSOCIATIONS. 2013 13 3557 36 IMPACT OF BMI AND WAIST CIRCUMFERENCE ON EPIGENOME-WIDE DNA METHYLATION AND IDENTIFICATION OF EPIGENETIC BIOMARKERS IN BLOOD: AN EWAS IN MULTI-ETHNIC ASIAN INDIVIDUALS. BACKGROUND: THE PREVALENCE OF OBESITY AND ITS RELATED CHRONIC DISEASES HAVE BEEN INCREASING ESPECIALLY IN ASIAN COUNTRIES. OBESITY-RELATED GENETIC VARIANTS HAVE BEEN IDENTIFIED, BUT THESE EXPLAIN LITTLE OF THE VARIATION IN BMI. RECENT STUDIES REPORTED ASSOCIATIONS BETWEEN DNA METHYLATION AND OBESITY, MOSTLY IN NON-ASIAN POPULATIONS. METHODS: WE PERFORMED AN EPIGENOME-WIDE ASSOCIATION STUDY (EWAS) ON GENERAL ADIPOSITY (BODY MASS INDEX, BMI) AND ABDOMINAL ADIPOSITY (WAIST CIRCUMFERENCE, WC) IN 409 MULTI-ETHNIC ASIAN INDIVIDUALS AND REPLICATED BMI AND WAIST-ASSOCIATED DNA METHYLATION CPGS IDENTIFIED IN OTHER POPULATIONS. THE CROSS-LAGGED PANEL MODEL AND MENDELIAN RANDOMIZATION WERE USED TO ASSESS THE TEMPORAL RELATIONSHIP BETWEEN METHYLATION AND BMI. THE TEMPORAL RELATIONSHIP BETWEEN THE IDENTIFIED CPGS AND INFLAMMATION AND METABOLIC MARKERS WAS ALSO EXAMINED. RESULTS: EWAS IDENTIFIED 116 DNA METHYLATION CPGS INDEPENDENTLY ASSOCIATED WITH BMI AND EIGHT INDEPENDENTLY ASSOCIATED WITH WC AT FALSE DISCOVERY RATE P(FDR) < 0.05 IN 409 ASIAN SAMPLES. WE REPLICATED 110 BMI-ASSOCIATED CPGS PREVIOUSLY REPORTED IN EUROPEANS AND IDENTIFIED SIX NOVEL BMI-ASSOCIATED CPGS AND TWO NOVEL WC-ASSOCIATED CPGS. WE OBSERVED HIGH CONSISTENCY IN ASSOCIATION DIRECTION OF EFFECT COMPARED TO STUDIES IN OTHER POPULATIONS. CAUSAL RELATIONSHIP ANALYSES INDICATED THAT BMI WAS MORE LIKELY TO BE THE CAUSE OF DNA METHYLATION ALTERATION, RATHER THAN THE CONSEQUENCE. THE CAUSAL ANALYSES USING BMI-ASSOCIATED METHYLATION RISK SCORE ALSO SUGGESTED THAT HIGHER LEVELS OF THE INFLAMMATION MARKER IL-6 WERE LIKELY THE CONSEQUENCE OF METHYLATION CHANGE. CONCLUSION: OUR STUDY PROVIDES EVIDENCE OF AN ASSOCIATION BETWEEN OBESITY AND DNA METHYLATION IN MULTI-ETHNIC ASIANS AND SUGGESTS THAT OBESITY CAN DRIVE METHYLATION CHANGE. THE RESULTS ALSO SUGGESTED POSSIBLE CAUSAL INFLUENCE THAT OBESITY-RELATED METHYLATION CHANGES MIGHT HAVE ON INFLAMMATION AND LIPOPROTEIN LEVELS. 2021 14 339 36 ALTERATIONS IN HOMOCYSTEINE METABOLISM AMONG ALCOHOL DEPENDENT PATIENTS--CLINICAL, PATHOBIOCHEMICAL AND GENETIC ASPECTS. ADDICTION RESEARCH FOCUSING ON HOMOCYSTEINE METABOLISM AND ITS ASSOCIATION WITH ASPECTS OF ALCOHOL DEPENDENCE HAS REVEALED IMPORTANT FINDINGS. RECENT LITERATURE ON THIS TOPIC HAS BEEN TAKEN INTO ACCOUNT FOR THE REVIEW PROVIDED. METHYLENETETRAHYDROFOLATE REDUCTASE (MTHFR) IS A KEY ENZYME IN THE HOMOCYSTEINE METABOLISM. PLASMA HOMOCYSTEINE LEVELS ARE INFLUENCED BY THE SINGLE-NUCLEOTIDE POLYMORPHISM (SNP) MTHFR C677T. BESIDES GENETIC FACTORS, ENVIRONMENTAL FACTORS HAVE AN IMPACT ON HOMOCYSTEINE PLASMA LEVELS TOO. THUS, CHRONIC ALCOHOL INTAKE IS ASSOCIATED WITH ELEVATED HOMOCYSTEINE PLASMA CONCENTRATIONS. ELEVATION OF PLASMA HOMOCYSTEINE CONCENTRATION IS CONSIDERED AS A PREDICTOR FOR THE OCCURRENCE OF ALCOHOL WITHDRAWAL SEIZURES AND--AS HOMOCYSTEINE IS A CARDIOVASCULAR RISK FACTOR--MIGHT CONTRIBUTE TO THE HIGHER RISK FOR MYOCARDIAL INFARCTION AMONG ALCOHOL DEPENDENT PATIENTS. HOMOCYSTEINE ACTS AS AN N-METHYL-D-ASPARTATE (NMDA) RECEPTOR AGONIST AND HAS EXCITOTOXIC EFFECTS. FURTHERMORE, IT HAS BEEN DEMONSTRATED THAT HOMOCYSTEINE HAS NEUROTOXIC EFFECTS ESPECIALLY ON DOPAMINERGIC NEURONS. AS THE REWARDING EFFECTS OF ALCOHOL ARE MEDIATED BY THE DOPAMINERGIC SYSTEM, A HOMOCYSTEINE-DEPENDENT IMPAIRMENT OF THE REWARD SYSTEM POSSIBLY LEADS TO AN ALTERED DRINKING BEHAVIOUR ACCORDING TO THE DEFICIT HYPOTHESIS OF ADDICTION. HOMOCYSTEINE IS INVOLVED IN THE METABOLISM OF METHYL GROUPS AND DNA-METHYLATION PLAYS A ROLE IN REGULATION OF GENE EXPRESSION. THEREFORE IT HAS BEEN SUGGESTED THAT HOMOCYSTEINE IS AN IMPORTANT EPIGENETIC FACTOR. IT REMAINS TO BE DETERMINED WHETHER ALCOHOL DEPENDENT PATIENTS BENEFIT FROM HOMOCYSTEINE LOWERING STRATEGIES, E.G., VIA SUPPLEMENTATION OF FOLATE, VITAMIN B6 AND B12. IN THIS RESPECT IT IS NOT CLEAR YET, IF A SUPPLEMENTATION THERAPY CAN REDUCE THE RISK FOR THE OCCURRENCE OF ALCOHOL WITHDRAWAL SEIZURES. 2008 15 4214 44 METHIONINE METABOLISM IN YUCATAN MINIATURE SWINE. METHIONINE IS AN ESSENTIAL AMINO ACID WHICH WHEN NOT INCORPORATED INTO PROTEIN, CAN BE CONVERTED TO S-ADENOSYLMETHIONINE, THE UNIVERSAL METHYL DONOR IN OVER 200 TRANSMETHYLATION REACTIONS, WHICH INCLUDE CREATINE AND PHOSPHATIDYLCHOLINE (PC) SYNTHESIS, AS WELL AS DEOXYRIBONUCLEIC ACID (DNA) METHYLATION. FOLLOWING TRANSMETHYLATION, HOMOCYSTEINE IS FORMED, WHICH CAN BE CONVERTED TO CYSTEINE VIA TRANSSULFURATION OR REMETHYLATED TO METHIONINE BY RECEIVING A METHYL GROUP FROM FOLATE OR BETAINE. CHANGES TO METHYL GROUP AVAILABILITY IN UTERO CAN LEAD TO PERMANENT CHANGES IN EPIGENETIC PATTERNS OF DNA METHYLATION, WHICH HAS BEEN IMPLICATED IN "FETAL PROGRAMMING", A PHENOMENON ASSOCIATED WITH POOR NUTRITION DURING FETAL DEVELOPMENT THAT RESULTS IN LOW BIRTH WEIGHT AND DISEASE IN LATER LIFE. IT HAS BEEN SHOWN THAT PROGRAMMING CAN ALSO OCCUR IN THE NEONATE. OUR GLOBAL OBJECTIVE WAS TO UNDERSTAND HOW THE VARIABILITY OF NUTRIENTS INVOLVED IN METHIONINE METABOLISM CAN AFFECT METHIONINE AND METHYL GROUP AVAILABILITY. WE HYPOTHESIZE THAT NUTRIENTS THAT CONVERGE ON METHIONINE METABOLISM CAN AFFECT METHIONINE AVAILABILITY FOR ITS VARIOUS FUNCTIONS. IN THIS THESIS, WE USED INTRAUTERINE GROWTH RESTRICTED (IUGR) PIGLETS TO INVESTIGATE WHETHER A GLOBAL NUTRITIONAL INSULT IN UTERO CAN LEAD TO A PERTURBED METHIONINE METABOLISM. OUR RESULTS DEMONSTRATE THAT IUGR PIGLETS HAVE A LOWER CAPACITY TO DISPOSE OF HOMOCYSTEINE VIA BOTH TRANSSULFURATION AND REMETHYLATION PATHWAYS, AS WELL AS A LOWER INCORPORATION OF METHYL GROUPS INTO PC. THE SECOND OBJECTIVE OF THIS THESIS WAS TO DETERMINE WHETHER VARIATION IN METHIONINE SUPPLY AND DEMAND CAN AFFECT METHIONINE AVAILABILITY. WE DEMONSTRATED THAT STIMULATING EITHER ACUTE OR CHRONIC CREATINE SYNTHESIS LEADS TO LOWER METHYL INCORPORATION INTO PROTEIN AND PC IN PIGS. FURTHERMORE, WHEN METHIONINE IS LIMITING, SUPPLEMENTATION WITH EITHER FOLATE OR BETAINE LEADS TO HIGHER METHIONINE AVAILABILITY FOR PROTEIN SYNTHESIS. FINALLY, BECAUSE CREATINE IS INCREASINGLY BEING UTILIZED AS AN ERGOGENIC AND NEUROPROTECTIVE SUPPLEMENT, WE WANTED TO DETERMINE WHETHER PROVISION OF THE CREATINE PRECURSOR, GUANIDINOACETATE (GAA), COULD EFFECTIVELY INCREASE TISSUE CREATINE STORES. WE SHOWED THAT 2.5 WEEKS OF SUPPLEMENTATION WITH GAA IS MORE EFFECTIVE THAN CREATINE AT INCREASING HEPATIC AND MUSCLE CREATINE STORES. THE RESULTS OF THIS THESIS DEMONSTRATE THAT THE PRESENCE OF IUGR, AN INCREASED DEMAND FOR CREATINE SYNTHESIS, OR THE SUPPLEMENTATION WITH REMETHYLATION NUTRIENTS CAN EACH AFFECT METHIONINE AVAILABILITY; ALL ARE IMPORTANT WHEN CONSIDERING NEONATAL NUTRIENT REQUIREMENTS. FURTHERMORE, ALTHOUGH GAA IS EFFECTIVE AT INCREASING LEVELS OF TISSUE CREATINE, HIGHER GAA METHYLATION CAN LIMIT METHIONINE AVAILABILITY FOR GROWTH AND SYNTHESIS OF PC. 2016 16 520 31 ASSOCIATIONS BETWEEN MATERNAL PRENATAL STRESS, METHYLATION CHANGES IN IGF1 AND IGF2, AND BIRTH WEIGHT. MATERNAL STRESS HAS BEEN LINKED TO LOW BIRTH WEIGHT IN NEWBORNS. ONE POTENTIAL PATHWAY INVOLVES EPIGENETIC CHANGES AT CANDIDATE GENES THAT MAY MEDIATE THE EFFECTS OF PRENATAL MATERNAL STRESS ON BIRTH WEIGHT. THIS RELATIONSHIP HAS BEEN DOCUMENTED IN STRESS-RELATED GENES, SUCH AS NR3C1. THERE IS LESS LITERATURE EXPLORING THE EFFECT OF STRESS ON GROWTH-RELATED GENES. IGF1 AND IGF2 HAVE BEEN IMPLICATED IN FETAL GROWTH AND DEVELOPMENT, THOUGH VIA DIFFERENT MECHANISMS AS IGF2 IS UNDER IMPRINTING CONTROL. IN THIS STUDY, WE TESTED FOR ASSOCIATIONS BETWEEN PRENATAL STRESS, METHYLATION OF IGF1 AND IGF2, AND BIRTH WEIGHT. A TOTAL OF 24 MOTHER-NEWBORN DYADS IN THE DEMOCRATIC REPUBLIC OF CONGO WERE ENROLLED. ETHNOGRAPHIC INTERVIEWS WERE CONDUCTED WITH MOTHERS AT DELIVERY TO GATHER CULTURALLY RELEVANT WAR-RELATED AND CHRONIC STRESSORS. DNA METHYLATION DATA WERE GENERATED FROM MATERNAL VENOUS, CORD BLOOD AND PLACENTAL TISSUE SAMPLES. MULTIVARIATE REGRESSIONS WERE USED TO TEST FOR ASSOCIATIONS BETWEEN STRESS MEASURES, DNA METHYLATION AND BIRTH WEIGHT IN EACH OF THE THREE TISSUE TYPES. WE FOUND AN ASSOCIATION BETWEEN IGF2 METHYLATION IN MATERNAL BLOOD AND BIRTH WEIGHT. PREVIOUS LITERATURE ON THE RELATIONSHIP BETWEEN IGF2 METHYLATION AND BIRTH WEIGHT HAS FOCUSED ON METHYLATION AT KNOWN DIFFERENTIALLY METHYLATED REGIONS IN CORD BLOOD OR PLACENTAL SAMPLES. OUR FINDINGS INDICATE THERE MAY BE LINKS BETWEEN THE MATERNAL EPIGENOME AND LOW BIRTH WEIGHT THAT RELY ON MECHANISMS OUTSIDE KNOWN IMPRINTING PATHWAYS. IT THUS MAY BE IMPORTANT TO CONSIDER THE EFFECT OF MATERNAL EXPOSURES AND EPIGENETIC PROFILES ON BIRTH WEIGHT EVEN IN THE SETTING OF MATERNALLY IMPRINTED GENES SUCH AS IGF2. 2018 17 3179 37 HAIR CORTISOL AS A HYPOTHALAMIC-PITUITARY-ADRENAL AXIS BIOMARKER IN PREGNANT WOMEN WITH ASTHMA: A RETROSPECTIVE OBSERVATIONAL STUDY. BACKGROUND: CORTISOL IS A HORMONE INVOLVED IN MANY PHYSIOLOGICAL FUNCTIONS INCLUDING FETAL MATURATION AND EPIGENETIC PROGRAMMING DURING PREGNANCY. THIS STUDY AIMED TO USE HAIR CORTISOL AS A BIOMARKER OF CHRONIC INHALED CORTICOSTEROID (ICS) EXPOSURE AND ASSESS THE POTENTIAL EFFECTS OF ASTHMA ON THE HYPOTHALAMIC-PITUITARY-ADRENAL (HPA) AXIS IN PREGNANT WOMEN. WE HYPOTHESIZED THAT PREGNANT WOMEN WITH ASTHMA TREATED WITH ICS WOULD EXHIBIT LOWER HAIR CORTISOL CONCENTRATIONS, INDICATIVE OF ADRENAL SUPPRESSION, COMPARED TO WOMEN WITH ASTHMA NOT USING ICS AND WOMEN WHO DO NOT HAVE ASTHMA. METHODS: WE PERFORMED AN OBSERVATIONAL RETROSPECTIVE COHORT STUDY. HAIR SAMPLES WERE ANALYZED FROM PREGNANT WOMEN WITH ASTHMA, WITH (N = 56) AND WITHOUT (N = 31) ICS TREATMENT, AND PREGNANT WOMEN WITHOUT ASTHMA (N = 31). HAIR SAMPLES WERE SEGMENTED BASED ON THE GROWTH RATE OF 1 CM/MONTH AND ANALYZED BY ENZYME IMMUNOASSAY TO PROVIDE CORTISOL CONCENTRATIONS CORRESPONDING TO PRECONCEPTION, TRIMESTERS 1-3, AND POSTPARTUM. HAIR CORTISOL CONCENTRATIONS WERE COMPARED WITHIN AND AMONG THE GROUPS USING NON-PARAMETRIC STATISTICAL TESTS. RESULTS: HAIR CORTISOL CONCENTRATIONS INCREASED ACROSS TRIMESTERS FOR ALL THREE GROUPS, BUT THIS INCREASE WAS DAMPENED IN WOMEN WITH ASTHMA (P = 0.03 FOR CONTROLS VS. ICS TREATED AND CONTROLS VS. NO ICS). ICS TREATED WOMEN TAKING MORE THAN FIVE DOSES PER WEEK HAD HAIR CORTISOL CONCENTRATIONS 47 % LOWER IN THIRD TRIMESTER THAN CONTROLS. LINEAR REGRESSION OF THE THIRD TRIMESTER HAIR CORTISOL RESULTS IDENTIFIED ASTHMA AS A SIGNIFICANT FACTOR WHEN COMPARING CONSISTENT ICS USE OR ASTHMA AS THE PREDICTOR (F(1, 25) = 9.7, P = 0.005, R(2) ADJ = 0.257). CONCLUSIONS: HAIR CORTISOL SUCCESSFULLY SHOWED THE EXPECTED CHANGE IN CORTISOL OVER THE COURSE OF PREGNANCY AND MAY BE A USEFUL BIOMARKER OF HPA AXIS FUNCTION IN PREGNANT WOMEN WITH ASTHMA. THE POTENTIAL IMPACT OF DECREASED MATERNAL CORTISOL IN WOMEN WITH ASTHMA ON PERINATAL OUTCOMES REMAINS TO BE DETERMINED. 2016 18 537 21 ASYMPTOMATIC HYPERURICEMIA: IS IT REALLY ASYMPTOMATIC? PURPOSE OF REVIEW: HYPERURICEMIA IS HIGHLY PREVALENT, AFFECTING APPROXIMATELY 38 MILLION INDIVIDUALS IN THE UNITED STATES. HOWEVER, THE SIGNIFICANCE OF ASYMPTOMATIC HYPERURICEMIA - HYPERURICEMIA IN THE ABSENCE OF GOUT - CONTINUES TO BE DEBATED. RECENT FINDINGS: ASYMPTOMATIC HYPERURICEMIA RESULTS IN MONOSODIUM URATE CRYSTAL DEPOSITION IN TISSUES, WHICH MAY PROMOTE CHRONIC INFLAMMATION. INTRACELLULARLY, HYPERURICEMIA INHIBITS THE MASTER REGULATOR ADENOSINE MONOPHOSPHATE (AMP)-ASSOCIATED PROTEIN KINASE AND MAY CONDITION INNATE IMMUNE RESPONSES THROUGH DURABLE EPIGENETIC MODIFICATIONS. AT THE POPULATION LEVEL, ASYMPTOMATIC HYPERURICEMIA IS ASSOCIATED WITH MULTIPLE COMORBIDITIES, INCLUDING HYPERTENSION, CHRONIC KIDNEY DISEASE, CORONARY ARTERY DISEASE, AND DIABETES; LIMITATIONS OF THESE STUDIES INCLUDE THAT MOST ARE RETROSPECTIVE AND SOME DO NOT RIGOROUSLY DISTINGUISH BETWEEN ASYMPTOMATIC HYPERURICEMIA AND GOUT. TREATMENT STUDIES SUGGEST THAT URATE LOWERING MAY REDUCE THE RISK OF INCIDENCE OR PROGRESSION OF SOME OF THESE COMORBIDITIES; UNFORTUNATELY, MANY OF THESE TREATMENT STUDIES ARE SMALL OR FLAWED, AND NOT ALL STUDY RESULTS ARE CONSISTENT. SUMMARY: ACCUMULATING EVIDENCE SUGGESTS THAT ASYMPTOMATIC HYPERURICEMIA CONTRIBUTES TO THE COMORBIDITIES WITH WHICH IT ASSOCIATES AND THAT PROPER ASYMPTOMATIC HYPERURICEMIA TREATMENT MAY REDUCE FUTURE RISK. ADDITIONAL PROSPECTIVE TRIALS ARE NEEDED TO DEFINITELY ESTABLISH CAUSALITY AND SUPPORT DECISION-MAKING AS TO WHETHER, AND WHICH PATIENTS WITH ASYMPTOMATIC HYPERURICEMIA WOULD WARRANT URATE-LOWERING TREATMENT. 2020 19 649 33 BIRTHWEIGHT, MATERNAL WEIGHT TRAJECTORIES AND GLOBAL DNA METHYLATION OF LINE-1 REPETITIVE ELEMENTS. LOW BIRTHWEIGHT, PREMATURE BIRTH, INTRAUTERINE GROWTH RETARDATION, AND MATERNAL MALNUTRITION HAVE BEEN RELATED TO AN INCREASED RISK OF CARDIOVASCULAR DISEASE, TYPE 2 DIABETES MELLITUS, OBESITY, AND NEUROPSYCHIATRIC DISORDERS LATER IN LIFE. CONVERSELY, HIGH BIRTHWEIGHT HAS BEEN LINKED TO FUTURE RISK OF CANCER. GLOBAL DNA METHYLATION ESTIMATED BY THE METHYLATION OF REPETITIVE SEQUENCES IN THE GENOME IS AN INDICATOR OF SUSCEPTIBILITY TO CHRONIC DISEASES. WE USED DATA AND BIOSPECIMENS FROM AN EPIGENETIC BIRTH COHORT TO EXPLORE THE ASSOCIATION BETWEEN TRAJECTORIES OF FETAL AND MATERNAL WEIGHT AND LINE-1 METHYLATION IN 319 MOTHER-CHILD DYADS. NEWBORNS WITH LOW OR HIGH BIRTHWEIGHT HAD SIGNIFICANTLY LOWER LINE-1 METHYLATION LEVELS IN THEIR CORD BLOOD COMPARED TO NORMAL WEIGHT INFANTS AFTER ADJUSTING FOR GESTATIONAL AGE, SEX OF THE CHILD, MATERNAL AGE AT DELIVERY, AND MATERNAL SMOKING DURING PREGNANCY (P = 0.007 AND P = 0.036, RESPECTIVELY), BUT THE MAGNITUDE OF THE DIFFERENCE WAS SMALL. INFANTS BORN PREMATURELY ALSO HAD LOWER LINE-1 METHYLATION LEVELS IN CORD BLOOD COMPARED TO TERM INFANTS, AND THIS DIFFERENCE, THOUGH SMALL, WAS STATISTICALLY SIGNIFICANT (P = 0.004). WE DID NOT FIND IMPORTANT ASSOCIATIONS BETWEEN MATERNAL PREPREGNANCY BMI OR GESTATIONAL WEIGHT GAIN AND GLOBAL METHYLATION OF THE CORD BLOOD OR FETAL PLACENTAL TISSUE. IN CONCLUSION, WE FOUND SIGNIFICANT DIFFERENCES IN CORD BLOOD LINE-1 METHYLATION AMONG NEWBORNS WITH LOW AND HIGH BIRTHWEIGHT AS WELL AS AMONG PREMATURELY BORN INFANTS. FUTURE STUDIES MAY ELUCIDATE WHETHER CHROMOSOMAL INSTABILITIES OR OTHER FUNCTIONAL CONSEQUENCES OF THESE CHANGES CONTRIBUTE TO THE INCREASED RISK OF CHRONIC DISEASES AMONG INDIVIDUALS WITH THESE CHARACTERISTICS. 2011 20 404 41 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