title: Analyses of copy number variation reveal putative susceptibility loci in MTX-induced mouse neural tube defects.
abstract: Copy number variations (CNVs) are thought to act as an important genetic mechanism underlying phenotypic heterogeneity. Impaired folate metabolism can result in neural tube defects (NTDs). However, the precise nature of the relationship between low folate status and NTDs remains unclear. Using an array-comparative genomic hybridization (aCGH) assay, we investigated whether CNVs could be detected in the NTD embryonic neural tissues of methotrexate (MTX)-induced folate dysmetabolism pregnant C57BL/6 mice and confirmed the findings with quantitative real-time PCR (qPCR). The CNVs were then comprehensively investigated using bioinformatics methods to prioritize candidate genes. We measured dihydrofolate reductase (DHFR) activity and concentrations of folate and relevant metabolites in maternal serum using enzymologic method and liquid chromatography/tandem mass spectrometry (LC/MS/MS). Three high confidence CNVs on XqA1.1, XqA1.1-qA2, and XqE3 were found in the NTD embryonic neural tissues. Twelve putative genes and three microRNAs were identified as potential susceptibility candidates in MTX-induced NTDs and possible roles in NTD pathogenesis. DHFR activity and 5-methyltetrahydrofolate (5-MeTHF), 5-formyltetrahydrofolate (5-FoTHF), and S-adenosylmethionine (SAM) concentrations of maternal serum decreased significantly after MTX injection. These findings suggest that CNVs caused by defects in folate metabolism lead to NTD, and further support the hypothesis that folate dysmetabolism is a direct cause for CNVs in MTX-induced NTDs.
authors: Department of Biotechnology, Beijing Municipal Key Laboratory of Child Development and Nutriomics, Capital Institute of Pediatrics, Beijing, 100020, China.
authors: Jianhua
authors: J
authors: Wang
authors: Xiuwei
authors: X
authors: Wang
authors: Tao
authors: T
authors: Guan
authors: Qian
authors: Q
authors: Xiang
authors: Mingsheng
authors: M
authors: Wang
authors: Zhi
authors: Z
authors: Zhang
authors: Zhen
authors: Z
authors: Guan
authors: Guoliang
authors: G
authors: Wang
authors: Zhiqiang
authors: Z
authors: Zhu
authors: Qiu
authors: Q
authors: Xie
authors: Guannan
authors: G
authors: Li
authors: Jin
authors: J
authors: Guo
authors: Fang
authors: F
authors: Wang
authors: Zhengguo
authors: Z
authors: Zhang
authors: Bo
authors: B
authors: Niu
authors: Ting
authors: T
authors: Zhang
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid; D055028:Comparative Genomic Hybridization; D056915:DNA Copy Number Variations; D004195:Disease Models, Animal; D005492:Folic Acid / Q000097:blood; D020869:Gene Expression Profiling; D020022:Genetic Predisposition to Disease; D002955:Leucovorin / Q000097:blood; D008727:Methotrexate; D008810:Mice, Inbred C57BL; D035683:MicroRNAs; D009436:Neural Tube Defects / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D060888:Real-Time Polymerase Chain Reaction; D012436:S-Adenosylmethionine / Q000097:blood; D053719:Tandem Mass Spectrometry; D013762:Tetrahydrofolate Dehydrogenase / Q000097:blood; D013763:Tetrahydrofolates / Q000097:blood
chemical_list: D035683:MicroRNAs; D013763:Tetrahydrofolates; D012436:S-Adenosylmethionine; D005492:Folic Acid; D013762:Tetrahydrofolate Dehydrogenase; D002955:Leucovorin; C005984:5-methyltetrahydrofolate; D008727:Methotrexate
keywords: DNA copy number variations; folate; methotrexate; mice; neural tube defects