大鼠脑创伤后海马CA3区细胞凋亡及相关基因表达研究

The study on apoptosis and the expression of related genes at CA3 zone of hippocampus after diffuse brain injury in rats

目的 研究弥漫性脑损伤后不同时间 ,大鼠海马CA3区细胞凋亡及相关基因Bcl 2、Bax和Caspase 3蛋白的表达情况 ,探讨脑创伤后神经细胞凋亡的分子生物学机制。方法 应用流式细胞仪和免疫组化法 ,分别检测脑创伤后不同时间海马CA3区细胞凋亡率及Bcl 2 ,Bax和Caspase 3基因在蛋白质水平的表达情况。结果 脑创伤后海马CA3区存在不同程度细胞凋亡 ,Bcl 2在脑损伤后表达下降 ,而Bax和Caspase 3在脑创伤后表达升高 ;Caspase 3表达的峰值时间 (72h)出现在Bax之后 (4 8h)。结论 弥漫性脑损伤后 ,大鼠海马CA3区存在细胞凋亡及Bcl 2 ,Bax和Caspase 3的表达变化。Bcl 2 /Bax表达比值下降早于Caspase 3的上升 ,Bcl 2 /Bax表达比值改变可能与Caspase 3活化有关 。

Objective To study apoptosis and the expression of the related genes protein, including Bcl-2 ,Bax and Caspase-3,at CA3 zone of hippocampus at different survival time after diffuse brain injury in rats, and to investigate the molecular mechanism of neuronal apoptosis following cerebral trauma.Methods Both brain cell apoptotic rate and the expression of Bcl-2, Bax and Caspase-3 protein at CA3 zone of hippocampus in different time following brain trauma had been detected respectively using flow cytometry (FCM) and immunohistochemistry.Results Different degrees of neuronal apoptosis at CA3 zone after brain trauma could be detected; the expression of Bcl-2 protein decreased, while the immunoreactivity of Bax and Caspase-3 protein increased after cerebral trauma; the peak time of the expression of Caspase-3 protein presented later than that of Bax protein.Conclusion There are different degrees of cell apoptosis and the alteration of immunoreactivity of Bcl-2, Bax and Caspase-3 protein at CA3 zone of hippocampus in rats after diffuse brain injury. The descending of the ratio of the expression of Bcl-2 vs Bax protein prior to the increase of expression of Caspase, it is implied that the ratio of Bcl-2 protein vs Bax may facilitate the activation of Caspase-3 and accelerate neuronal apoptosis.