Title: Self-reported prenatal tobacco smoke exposure, AXL gene-body methylation, and childhood asthma phenotypes.
Authors: Gao, Lu; Liu, Xiaochen; Millstein, Joshua; Siegmund, Kimberly D; Dubeau, Louis; Maguire, Rachel L; Jim Zhang, Junfeng; Fuemmeler, Bernard F; Kollins, Scott H; Hoyo, Cathrine; Murphy, Susan K; Breton, Carrie V
Published In Clin Epigenetics, (2018 07 20)
Abstract: Epigenetic modifications, including DNA methylation, act as one potential mechanism underlying the detrimental effects associated with prenatal tobacco smoke (PTS) exposure. Methylation in a gene called AXL was previously reported to differ in response to PTS.We investigated the association between PTS and epigenetic changes in AXL and how this was related to childhood asthma phenotypes. We tested the association between PTS and DNA methylation at multiple CpG loci of AXL at birth using Pyrosequencing in two separate study populations, the Children's Health Study (CHS, n = 799) and the Newborn Epigenetic Study (NEST, n = 592). Plasma cotinine concentration was used to validate findings with self-reported smoking status. The inter-relationships among AXL mRNA and miR-199a1 expression, PTS, and AXL methylation were examined. Lastly, we evaluated the joint effects of AXL methylation and PTS on the risk of asthma and related symptoms at age 10 years old.PTS was associated with higher methylation level in the AXL gene body in both CHS and NEST subjects. In the pooled analysis, exposed subjects had a 0.51% higher methylation level in this region compared to unexposed subjects (95% CI 0.29, 0.74; p < 0.0001). PTS was also associated with 21.2% lower expression of miR-199a1 (95% CI - 37.9, - 0.1; p = 0.05), a microRNA known to regulate AXL expression. Furthermore, the combination of higher AXL methylation and PTS exposure at birth increased the risk of recent episodes of bronchitic symptoms in childhood.PTS was associated with methylation level of AXL and the combination altered the risk of childhood bronchitic symptoms.
PubMed ID: 30029617
MeSH Terms: Asthma/blood; Asthma/chemically induced; Asthma/genetics*; Child; Cotinine/blood; DNA Methylation*; Epigenesis, Genetic; Female; Genetic Association Studies; Humans; Infant, Newborn; Male; MicroRNAs/genetics; Pregnancy; Prenatal Exposure Delayed Effects/blood; Prenatal Exposure Delayed Effects/chemically induced; Prenatal Exposure Delayed Effects/genetics*; Proto-Oncogene Proteins/genetics*; Receptor Protein-Tyrosine Kinases/genetics*; Self Report; Sequence Analysis, DNA; Smoking/adverse effects*; Smoking/genetics