Caspase-3、P53在神经上皮及间充质细胞的表达和意义

目的:探讨维甲酸致神经管畸形中细胞凋亡的发生机制。方法:应用维甲酸建立小鼠胚胎NTDs模型,采用核固红-结晶紫和免疫组化染色方法,观察鼠胚神经上皮和周围间充质细胞的凋亡情况及凋亡相关蛋白Caspase-3、P53在神经上皮表达的变化,用图像分析技术对不同胎龄鼠胚的神经上皮及其间充质细胞Caspase-3、P53蛋白的表达进行半定量分析。结果:①对照组鼠胚神经管发育良好,神经管在E9d闭合,细胞凋亡较少。实验组神经管大多未闭合,凋亡细胞较多,伴有凋亡小体。②实验组神经上皮细胞的凋亡率明显高于对照组(P<0.05),细胞凋亡率在E9d、E10d最高;实验组神经管周围间充质细胞的凋亡率在E9d、E10d、E11d最高,明显高于对照组(P<0.05)。③Caspase-3蛋白定位于神经上皮及其间充质细胞的胞膜和胞质,实验组该蛋白的表达在E9d、E10d达最高峰,显著高于对照组(P<0.05),以后又逐渐降低至对照组水平。④P53蛋白定位于胞质和胞膜,实验组P53蛋白在神经上皮及其间充质细胞的表达明显高于对照组(P<0.05),而且该蛋白的表达始终处于高水平,没有明显的峰值。结论:Caspase-3、P53蛋白的过度表达可能促进细胞凋亡,从而诱导NTDs的发生。

Expression and significance of Caspase-3,P53 in neural epithelium and mesenchymal cell of neural tube defects(NTDs) caused by retinoic acid

Objective:To explore the molecular mechanism of cell apoptosis on neural tube defects(NTDs) caused by retinoic acid(RA).Methods:Reveal the pathogenesis of NTDs.To set up NTDs model in mouse embryo by overdose RA.To observe the apoptosis situation and expression changes of apoptosis related proteins Caspase-3,P53 in neural epithelial and mesenchymal cells of mouse embryo by using nuclear solid red-crystallization purple stain and immunohistochemical methods.With image analysis technique to analyze the expression of Caspase-3,P53 on above-mentioned cells in different gestational age.Results: ①The neural tube developed well and closed after E9d with less cell apoptosis in control group.In experimental group,most neural tubes were not closed.There were more apoptotic cells with apoptotic body in sections of mouse embryo.② The apoptotic percentage of neuroepithelial cells in experimental group was significantly higher than that in the control group(P<0.05),it reached peak at E9d and E10d.The apoptotic percentage of mesenchymal cells was also significantly higher than that in the control group,it reached peak at E9d,E10d and E11d(P<0.05).③ The Caspase-3 protein located not only on the membranes but also in the cytoplasm of neural epithelial and mesenchymal cells.Its expression was significantly higher than that in the control group(P<0.05).The expression peak appeared in E9d and E10d,then reduced gradually to the level of in control group.④The P53 protein located also on the membranes and the cytoplasm,its expression on neural epithelial and mesenchymal cells was significantly higher than that in the control group(P<0.05).Its expression was always in high level,there was no obvious peak.Conclusion:The over-expression of Caspase-3,P53 protein may promote excessive cell apoptosis,thus inducing NTDs occurs.