Prenatal Exposure to Cadmium and Cotinine and CpG island DNA methylation in Mother-Infant Pairs.
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ABSTRACT:
SUBMITTER: Gona S
PROVIDER: S-EPMC4538703 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Cadmium (Cd) is prevalent in the environment yet understudied as a developmental toxicant. Cd partially crosses the placental barrier from mother to fetus and is linked to detrimental effects in newborns. Here we examine the relationship between levels of Cd during pregnancy and 5-methylcytosine (5mC) levels in leukocyte DNA collected from 17 mother-newborn pairs. The methylation of cytosines is an epigenetic mechanism known to impact transcriptional signaling and influence health endpoints. A methylated cytosine-guanine (CpG) island recovery assay was used to assess over 4.6 million sites spanning 16,421 CpG islands. Exposure to Cd was classified for each mother-newborn pair according to maternal blood levels and compared with levels of cotinine. Subsets of genes were identified that showed altered DNA methylation levels in their promoter regions in fetal DNA associated with levels of Cd (n = 61), cotinine (n = 366), or both (n = 30). Likewise, in maternal DNA, differentially methylated genes were identified that were associated with Cd (n = 92) or cotinine (n = 134) levels. While the gene sets were largely distinct between maternal and fetal DNA, functional similarities at the biological pathway level were identified including an enrichment of genes that encode for proteins that control transcriptional regulation and apoptosis. Furthermore, conserved DNA motifs with sequence similarity to specific transcription factor binding sites were identified within the CpG islands of the gene sets. This study provides evidence for distinct patterns of DNA methylation or "footprints" in fetal and maternal DNA associated with exposure to Cd.
| S-EPMC3962531 | biostudies-other
Project description:BackgroundPer- and polyfluoroalkyl substances (PFAS) are chemicals that are resistant to degradation and ubiquitous in our environments. PFAS may impact the developing epigenome, but current human evidence is limited to assessments of total DNA methylation. We assessed associations between first trimester PFAS exposures with newborn DNA methylation, including 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC). DNA methylation mediation of associations between PFAS and birth outcomes were explored in the Michigan Mother Infant Pairs cohort. Nine PFAS were measured in maternal first trimester blood. Seven were highly detected and included for analysis: PFHxS, PFOA, PFOS, PFNA, PFDA, PFUnDA, and MeFOSAA. Bisulfite-converted cord blood DNA (n = 141) and oxidative-bisulfite-converted cord blood (n = 70) were assayed on Illumina MethylationEPIC BeadChips to measure total DNA methylation (5-mC + 5-hmC) and 5-mC/5-hmC. Correcting for multiple comparisons, beta regressions were used to assess associations between levels of PFAS and total methylation, 5-mC, or 5-hmC. Nonlinear mediation analyses were used to assess the epigenetic meditation effect between PFAS and birth outcomes.ResultsPFAS was significantly associated with total methylation (q < 0.05: PFHxS-12 sites; PFOS-19 sites; PFOA-2 sites; PFNA-3 sites; PFDA-4 sites). In 72 female infants and 69 male infants, there were sex-specific associations between five PFAS and DNA methylation. 5-mC and 5-hmC were each significantly associated with thousands of sites for PFHxS, PFOS, PFNA, PFDA, PFUnDA, and MeFOSAA (q < 0.05). Clusters of 5-mC and 5-hmC sites were significant mediators between PFNA and PFUnDA and decreased gestational age (q < 0.05).ConclusionsThis study demonstrates the mediation role of specific types of DNA methylation on the relationship between PFAS exposure and birth outcomes. These results suggest that 5-mC and 5-hmC may be more sensitive to the developmental impacts of PFAS than total DNA methylation.
| S-EPMC10037903 | biostudies-literature
Project description:The main source of mercury (Hg) exposure in the general population is fish. Another possible source is dental amalgam. Here, we compare the levels of Hg and selenium (Se) in samples of maternal and fetal origin collected shortly after childbirth of healthy postpartum women in the coastal (n = 96) and continental (n = 185) areas of Croatia related to maternal seafood/fish consumption. We also evaluated Hg concentrations and maternal serum metallothionein (MT2) concentrations in relation to the number of dental amalgam fillings, and MT2A-5A/G (rs28366003) polymorphism. The levels of Hg and Se in maternal hair and blood/serum, placenta and cord blood/serum increased in relation to increasing fish consumption with the highest values in subjects from the coast. The concentrations of each element and between elements correlated across the matrices. Increasing amalgam number correlated linearly with increased Hg levels in maternal and cord serum and was not associated with serum MT2. No association of MT2A-5A/G polymorphism and Hg or Se levels were found. The results confirmed higher fish consumption in coastal vs. continental Croatia and increases of both Hg and Se related to fish consumption in all analyzed samples. Increased blood Hg reflected the predominant MeHg share from seafood, while increased serum Hg matched exposure from dental amalgams.
| S-EPMC7355586 | biostudies-literature
Project description:BackgroundSmoking while pregnant is associated with a myriad of negative health outcomes in the child. Some of the detrimental effects may be due to epigenetic modifications, although few studies have investigated this hypothesis in detail.ObjectivesTo characterize site-specific epigenetic modifications conferred by prenatal smoking exposure within asthmatic children.MethodsUsing Illumina HumanMethylation27 microarrays, we estimated the degree of methylation at 27,578 distinct DNA sequences located primarily in gene promoters using whole blood DNA samples from the Childhood Asthma Management Program (CAMP) subset of Asthma BRIDGE childhood asthmatics (n?=?527) ages 5-12 with prenatal smoking exposure data available. Using beta-regression, we screened loci for differential methylation related to prenatal smoke exposure, adjusting for gender, age and clinical site, and accounting for multiple comparisons by FDR.ResultsOf 27,578 loci evaluated, 22,131 (80%) passed quality control assessment and were analyzed. Sixty-five children (12%) had a history of prenatal smoke exposure. At an FDR of 0.05, we identified 19 CpG loci significantly associated with prenatal smoke, of which two replicated in two independent populations. Exposure was associated with a 2% increase in mean CpG methylation in FRMD4A (p?=?0.01) and Cllorf52 (p?=?0.001) compared to no exposure. Four additional genes, XPNPEP1, PPEF2, SMPD3 and CRYGN, were nominally associated in at least one replication group.ConclusionsThese data suggest that prenatal exposure to tobacco smoke is associated with reproducible epigenetic changes that persist well into childhood. However, the biological significance of these altered loci remains unknown.
| S-EPMC4070909 | biostudies-literature
Project description:Maternal prenatal psychosocial stress is associated with adverse hypothalamic-pituitary-adrenal axis (HPAA) function among infants. Although the biological mechanisms influencing this process remain unknown, altered DNA methylation is considered to be one potential mechanism. We investigated associations between maternal prenatal psychological distress, infant salivary DNA methylation, and stress physiology at 12 months. Mother's distress was measured via depression and anxiety in early and late pregnancy in a cohort of 80 pregnant adolescents. Maternal hair cortisol was collected during pregnancy. Saliva samples were collected from infants at 12 months to quantify DNA methylation of three stress-related genes (FKBP5, NR3C1, OXTR) (n = 62) and diurnal cortisol (n = 29). Multivariable linear regression was used to test for associations between prenatal psychological distress, and infant DNA methylation and cortisol. Hair cortisol concentrations in late pregnancy were negatively associated with two sites of FKBP5 (site 1: B = -22.33, p = .003; site 2: B = -15.60, p = .012). Infants of mothers with elevated anxiety symptoms in late pregnancy had lower levels of OXTR2 CpG2 methylation (B = -2.17, p = .03) and higher evening salivary cortisol (B = 0.41, p = .03). Furthermore, OXTR2 methylation was inversely associated with evening cortisol (B = -0.14, p-value ≤ .001). Our results are, to our knowledge, the first evidence that the methylation of the oxytocin receptor may contribute to the regulation of HPAA during infancy.
| S-EPMC9792831 | biostudies-literature
Project description:Epigenetic silencing associated with aberrant methylation of promoter region CpG islands is one mechanism leading to loss of tumor suppressor function in human cancer. Profiling of CpG island methylation indicates that some genes are more frequently methylated than others, and that each tumor type is associated with a unique set of methylated genes. However, little is known about why certain genes succumb to this aberrant event. To address this question, we used Restriction Landmark Genome Scanning to analyze the susceptibility of 1,749 unselected CpG islands to de novo methylation driven by overexpression of DNA cytosine-5-methyltransferase 1 (DNMT1). We found that although the overall incidence of CpG island methylation was increased in cells overexpressing DNMT1, not all loci were equally affected. The majority of CpG islands (69.9%) were resistant to de novo methylation, regardless of DNMT1 overexpression. In contrast, we identified a subset of methylation-prone CpG islands (3.8%) that were consistently hypermethylated in multiple DNMT1 overexpressing clones. Methylation-prone and methylation-resistant CpG islands were not significantly different with respect to size, C+G content, CpG frequency, chromosomal location, or promoter association. We used DNA pattern recognition and supervised learning techniques to derive a classification function based on the frequency of seven novel sequence patterns that was capable of discriminating methylation-prone from methylation-resistant CpG islands with 82% accuracy. The data indicate that CpG islands differ in their intrinsic susceptibility to de novo methylation, and suggest that the propensity for a CpG island to become aberrantly methylated can be predicted based on its sequence context.
| S-EPMC218745 | biostudies-literature
Project description:Paracetamol exposure has been positively associated with asthma development. The relative importance of prenatal vs infant exposure and confounding by indication remains elusive. We examined the association of prenatal and infant (first 6 months) paracetamol exposure with asthma development while addressing confounding by indication.We used information from the Norwegian Mother and Child Cohort Study, including 53169 children for evaluation of current asthma at 3 years, 25394 for current asthma at 7 years and 45607 for dispensed asthma medications at 7 years in the Norwegian Prescription Database. We calculated adjusted relative risks (adj. RR) and 95% confidence intervals (CI) using log-binomial regression.There were independent modest associations between asthma at 3 years with prenatal paracetamol exposure (adj. RR 1.13; 95% CI: 1.02-1.25) and use of paracetamol during infancy (adj. RR 1.29; 95% CI: 1.16-1.45). The results were consistent for asthma at 7 years. The associations with prenatal paracetamol exposure were seen for different indications (pain, respiratory tract infections/influenza and fever). Maternal pain during pregnancy was the only indication that showed an association both with and without paracetamol use. Maternal paracetamol use outside pregnancy and paternal paracetamol use were not associated with asthma development. In a secondary analysis, prenatal ibuprofen exposure was positively associated with asthma at 3 years but not asthma at 7 years.This study provides evidence that prenatal and infant paracetamol exposure have independent associations with asthma development. Our findings suggest that the associations could not be fully explained by confounding by indication.
| S-EPMC5841883 | biostudies-other
Project description:The biological mechanism of cadmium's effects is poorly characterized. This data was generated in order to help better understand the epigenetic role that Cadmium plays. We used the MIRA assay and the Affymetrix Human Promoter 1.0R Array in order to measure methylation levels in promoter regions.
2015-04-17 | GSE67976 | GEO
Project description:We compare the methylation status of CpG island clones by MeDIP in SW48 colon cancer cells relative to normal colon mucosa and WI38 primary fibroblasts. Keywords: ordered
2005-07-03 | GSE2653 | GEO
Project description:The biological mechanism of cadmium's effects is poorly characterized. This data was generated in order to help better understand the epigenetic role that Cadmium plays. We used the MIRA assay and the Affymetrix Human Promoter 1.0R Array in order to measure methylation levels in promoter regions. 34 samples corresponding to 17 mother-infant pairs were selected based upon measured levels of cadmium in the blood. Methylated DNA fragments were then isolated, amplified, and run on the Affymetrix Human Promoter 1.0R Array. Results were then summarized to CpG islands for each sample.
2015-04-17 | E-GEOD-67976 | biostudies-arrayexpress