低叶酸联合甲氨蝶呤诱导神经管畸形小鼠模型的建立

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

目的 通过低叶酸饲喂联合二氢叶酸还原酶竞争性抑制剂甲氨蝶呤对小鼠胚胎神经管发育产生影响,建立小鼠神经管畸形的动物模型。 方法 实验采用C57BL/6J小鼠,通过随机数字表法,分为正常饲喂组(以正常鼠粮饲喂)、低叶酸组以及低叶酸+甲氨蝶呤组。低叶酸+甲氨蝶呤组在孕7.5 d给予不同剂量的甲氨蝶呤(分别为1.00 mg/kg、1.25 mg/kg、1.50 mg/kg、2.50 mg/kg、3.50 mg/kg、4.50 mg/kg)腹腔注射,低叶酸组则给予等体积的生理盐水。于孕13.5 d收集3组小鼠胚胎,观察胚胎的表型,记录正常胎与畸形胎的数量、胎鼠顶臀长、胎鼠体质量以及胎盘的重量。 结果 低叶酸组小鼠可见发育迟缓,未见小鼠胚胎神经管畸形的发生;低叶酸+甲氨蝶呤组小鼠的神经管畸形比率最高为36.5%,且甲氨蝶呤应用剂量为1.50 mg/kg时,小鼠的畸形率最高,神经管畸形表型多为脊柱裂。 结论 低叶酸饲喂联合甲氨蝶呤可诱导小鼠胚胎神经管畸形的发生。

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.