Caspase-3、P53在神经上皮及间充质细胞的表达和意义

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

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。

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 apopto- sis situation and expression changes of apoptosis related proteins Caspase - 3, P53 in neural epithelial and mesenehymal cells of mouse em- bryo 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 apoptot- ic cells with apoptotie body in sections of mouse embryo. ② The apoptotie percentage of neuroepithelial cells in experimental group was sig- nificantly 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 , ElOd and Elld （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 signifi- cantly 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 mesen- chymal cells was significantly higher than that in the control group （ P 〈 0. 05 ） . Its expression was always in high level, there was no obvi- ous peak. Conclusion ： The over - expression of Caspase - 3, P53 protein may promote excessive cell apoptosis, thus inducing NTDs occurs.