title: Aberrant 5'-CpG Methylation of Cord Blood TNFα Associated with Maternal Exposure to Polybrominated Diphenyl Ethers.
abstract: Growing evidence suggests that maternal exposures to endocrine disrupting chemicals during pregnancy may lead to poor pregnancy outcomes and increased fetal susceptibility to adult diseases. Polybrominated diphenyl ethers (PBDEs), which are ubiquitously used flame-retardants, could leach into the environment; and become persistent organic pollutants via bioaccumulation. In the United States, blood PBDE levels in adults range from 30-100 ng/g- lipid but the alarming health concern revolves around children who have reported blood PBDE levels 3 to 9-fold higher than adults. PBDEs disrupt endocrine, immune, reproductive and nervous systems. However, the mechanism underlying its adverse health effect is not fully understood. Epigenetics is a possible biological mechanism underlying maternal exposure-child health outcomes by regulating gene expression without changes in the DNA sequence. We sought to examine the relationship between maternal exposure to environmental PBDEs and promoter methylation of a proinflammatory gene, tumor necrosis factor alpha (TNFα). We measured the maternal blood PBDE levels and cord blood TNFα promoter methylation levels on 46 paired samples of maternal and cord blood from the Boston Birth Cohort (BBC). We showed that decreased cord blood TNFα methylation associated with high maternal PBDE47 exposure. CpG site-specific methylation showed significantly hypomethylation in the girl whose mother has a high blood PBDE47 level. Consistently, decreased TNFα methylation associated with an increase in TNFα protein level in cord blood. In conclusion, our finding provided evidence that in utero exposure to PBDEs may epigenetically reprogram the offspring's immunological response through promoter methylation of a proinflammatory gene.
authors.affiliation: Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Tyna
authors.initials: T
authors.lastname: Dao
authors.affiliation: Department of Human Population and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Xiumei
authors.initials: X
authors.lastname: Hong
authors.affiliation: Department of Human Population and Reproductive Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America.
authors.forename: Wan-Yee
authors.initials: WY
authors.lastname: Tang
mesh_terms: D000328:Adult; D015988:Cohort Effect; D018899:CpG Islands / Q000187:drug effects*; D019175:DNA Methylation / Q000187:drug effects*; D044127:Epigenesis, Genetic / Q000187:drug effects; D005260:Female; D005312:Fetal Blood / Q000737:chemistry / Q000187:drug effects*; D055768:Halogenated Diphenyl Ethers / Q000009:adverse effects* / Q000097:blood; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D011247:Pregnancy; D011256:Pregnancy Outcome; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000235:genetics*
chemical_list: D055768:Halogenated Diphenyl Ethers; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha