Methotrexate-induced neural tube defects mouse model under folate deficient condition

Abstract

Objective To establish neural tube defect mouse model induced by folate antagonist methotrexate (MTX) under low folate diet, and to demonstrate folate deficiency acting as a sensitizing agent leading to neural tube defects. Methods C57BL/6J female mice were divided into 3 groups. Normal feeding group was fed with normal SPF diet. Low folate diet group was given special low folate food. Low folate and MTX group was injected intraperitoneally with MTX (1.00 mg/kg, 1.25 mg/kg, 1.50 mg/kg, 2.50 mg/kg, 3.50 mg/kg, 4.50 mg/kg, respectively) at E7.5 and dissected at E10.5 to E13.5. The other 2 groups were injected with equal volume of normal saline. The embryo phenotype was observed and the number of normal and deformed fetuses were counted. Fetal brain to hip lengths were measured. Embryos and placentae were weighted. Results In low folate diet group, developmental retardation was observed without mouse embryonic abnormality of neural tube defects (NTDs). The MTX dose of 1.50 mg/kg might led to the highest deformity rate of 36.5% in low folate diet plus MTX group and the phenotype of NTDs was mainly spina bifida. Conclusion Methotrexate with low folate diet could be used to establish the mouse model of NTDs. Key words: Neural tube defects; Methotrexate; Models, animal; Folate antagonist