论文部分内容阅读
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 investigate the mechanism of apoptosis induced by retinoic acid in neural tube defects. Methods: Rat embryonic NTDs model was established by retinoic acid. The apoptosis of neuronal epithelial cells and peripheral mesenchymal cells was observed by nuclear red-crystal violet staining and immunohistochemical staining. Caspase-3, The expression of P53 in neuroepithelial epithelial cells was detected by semiquantitative analysis of the expression of Caspase-3 and P53 protein in neuroepithelial and mesenchymal cells of embryos of different gestational age by image analysis technique. Results: ① The neural tube in the control group developed well and the neural tube closed at E9d with less apoptosis. Most of the experimental group of neural tube is not closed, more apoptotic cells, accompanied by apoptotic bodies. ② The apoptotic rate of neuroepithelial cells in the experimental group was significantly higher than that in the control group (P <0.05), and the apoptotic rate was the highest at E9d and E10d. The apoptotic rates of mesenchymal cells around the neural tube in the experimental group were significantly higher at E9d, E10d and E11d The highest, significantly higher than the control group (P <0.05). ③ Caspase-3 protein localized in the membrane and cytoplasm of neuroepithelial and mesenchymal cells. The expression of Caspase-3 protein reached the peak at E9d and E10d, significantly higher than that of the control group (P <0.05), and then gradually decreased to Control group level. P53 protein located in the cytoplasm and membrane, the experimental group P53 protein expression in the neural epithelium and mesenchymal cells was significantly higher (P <0.05), and the expression of the protein is always at high levels, no significant peak. Conclusion: Overexpression of Caspase-3 and P53 proteins may promote apoptosis and induce NTDs.