抑郁症大鼠海马神经元凋亡率和自噬相关蛋白的改变

目的 观察抑郁症模型大鼠海马神经元形态结构改变及凋亡、自噬的变化,探讨抑郁症海马体积异常的机制.方法 选用雄性成年SD大鼠,随机分为正常对照组和模型组,通过给予不可预见慢性温和应激建立抑郁症模型;采用尼氏染色、透射电镜技术观察海马神经元形态变化,流式细胞术检测海马神经元凋亡,采用透射电镜观察海马神经元自噬体,Western blott检测自噬相关蛋白LC-3和Beclin 1.结果 与对照组比较,模型组海马神经元体积萎缩,数量减少,细胞凋亡率增高（P〈0.05）.模型组海马神经元胞质内可见自噬体;与对照组相比,模型组LC-3Ⅱ蛋白和LC-3Ⅱ/LC-3Ⅰ比值增高,Beclin-1相对表达增高（P〈0.05）.结论 抑郁症大鼠海马神经元存在体积萎缩现象,可能与神经元凋亡和自噬增强有关.

Change of apoptosis rate and autophage-related protein in hippocampal neurons of depression model rats

Objective To observe the changes of neuron structure, apoptosis and autophage in the hippocampus of depression model rats. Methods Male SD rats were randomly divided into control group and model group. The depression animal model was produced by giving the rats chronic unpredicted mild stress. The stractural changes of hippocampal neurons were observed by Nissl and transmission electron microscopy. Double-labeled flow cytometry （FCM） was employed for the detection and quantification of the apoptotic cells in the hippcampus. The autophage in neurons was observed by transmission electron microscopy, and the expression of LC-3 and Beclin 1 were detected by Western blotting. Results Compared to those of the control group, the neuronal body was smaller, and the number of neurons decreased. The apoptotic cell rate of the model group was higher than that of the control group （P〈0.05）. Many autophagsome vacuoles were seen obviously in hippocampal neurons of the model rats under electron microscopy. The expression ratio of LC3-II to LC3-II and the expression level of Beclin-1 in the model group were higher than those in the control group （P~0.05）. Conclusion Apoptosis and atuophagy were increased in the hippocampus of depression model rats, which indicates that autophagy may induce the abnormal hippocampal volume of depressed rats.