WIF-1、SFRP-1在环磷酰胺致大鼠神经管畸形中神经上皮细胞表达的变化

目的:通过检测WIF-1和SFRP-1在环磷酰胺(CP)致大鼠神经管畸形(NTDs)中神经上皮细胞的表达及表达的变化,研究CP对胎鼠神经上皮细胞Wnt信号通路的影响,探讨NTDs发生的分子机制,为NTDs的预防、基因治疗提供理论依据。方法:将SD孕鼠随机分为实验组和对照组,分别于妊娠13天8～9时一次性腹腔注射CP(15 mg/kg)和等量的生理盐水。分别于给药后8、12、24 h处死孕鼠,剖腹取出胎鼠,用10%中性福尔马林固定,常规石蜡包埋、连续切片。应用免疫组织化学方法检测WIF-1与SFRP-1在神经管神经上皮细胞的表达及其变化。结果:①WIF-1免疫组化显示,给药后8 h,实验组WIF-1阳性细胞分布与对照组相似(P>0.05);给药后12 h,实验组WIF-1阳性表达增强(P<0.05);给药后24 h,实验组与对照组相比,神经管背侧、顶板区WIF-1阳性表达明显增强(P<0.01)。②SFRP-1免疫组化显示,SFRP-1在实验组和对照组各个时间段均有阳性表达,但差异无统计学意义(P>0.05)。结论:①WIF-1在神经上皮细胞表达增强与CP致NTDs密切相关。②SFRP-1在神经上皮细胞表达的改变未发现与CP致NTDs有相关性。③Wnt信号通路异常与CP致NTDs密切相关。

Changes of WIF-1 and SFRP-1 expressions in neuroepithelial cells of rats with neural tube defects induced by cyclophosphamide

Objective:To study the effect of cyclophosphamide on Wnt signaling pathway in neuroepithelial cells of fetal rats,explore the molecular mechanism of occurrence of neural tube defects,and provide a theoretical basis for prevention and gene therapy of neural tube defects by detecting the expressions and changes of expressions of Wnt inhibitory factor-1(WIF-1) and secreted frizzled related protein-1(SFRP-1) in neuroepithelial cells of rats with neural tube defects induced by cyclophosphamide.Methods:SD pregnant rats were randomly divided into experimental group and control group,the rats in the two groups were treated with one-time intraperitoneal injection of cyclophosphamide(15 mg/kg) and normal saline(15 mg/kg) at eight to nine on the thirteenth day of pregnancy.The pregnant rats were killed at 8,12,and 24 hours after drug administration,and then the fetal rats were obtained by laparotomy;10% formalin-fixed paraffin-embedded tissues were cut into slices serially.Immunohistochemical method was used to detect the expressions and changes of expressions of WIF-1 and SFRP-1 in neuroepithelial cells of rats with neural tube defects.Results:The results of immunohistochemistry showed that the distribution of neuroepithelial cells with positive WIF-1 in experimental group was similar to that in control group at 8 hours after drug administration(P>0.05);at 12 hours after drug administration,the positive expression rate of WIF-1 in experimental group increased significantly(P<0.05);at 24 hours after drug administration,the positive expression rates of WIF-1 in dorsal part and roof area of neural tubes in experimental group increased significantly(P<0.01).The results of immunohistochemistry showed that SFRP-1 positively expressed in experimental group and control group at all the time points,but there was no statistically significant difference(P>0.05).Conclusion:The high expression of WIF-1 in neuroepithelial cells is closely related to neural tube defects induced by cyclophosphamide.The change of SFRP-1 expression in neuroepithelial cells is not correlated with neural tube defects induced by cyclophosphamide.Abnormality of Wnt signaling pathway is closely correlated with neural tube defects induced by cyclophosphamide.