缺氧复氧致神经细胞凋亡中Bcl-2、Bax基因蛋白的表达

THE EXPRESSION OF Bcl-2 AND Bax PROTEIN IN THE APOPTOSIS OF NEURONS FOLLOWING HYPOXIA/REOXYGENATION

目的 探讨缺氧复氧致原代培养的大鼠大脑皮层神经细胞凋亡中Bcl 2、Bax基因蛋白的表达及其与凋亡的关系。 方法 用胎龄 17～ 18dWistar大鼠的大脑皮层神经细胞进行原代分离培养。采用TUNEL染色方法、流式细胞术确立缺氧复氧神经细胞凋亡病理模型 ,并用免疫组织化学方法显示缺氧复氧不同时间Bcl 2、Bax基因的动态表达。 结果 1.缺氧复氧可以使大鼠大脑皮层神经细胞发生凋亡 ,在分别缺氧 2、4、6、8h ,复氧 0h和18h组中 ,缺氧 4h开始出现凋亡细胞 ,随缺氧时间的延长 ,凋亡细胞数渐多 ,至缺氧 8h ,复氧 18h达高峰 ;2 .在单纯缺氧组中随缺氧时间延长 ,Bcl 2基因表达逐渐下降 ,Bax基因表达逐渐升高 ,两者呈显著负相关 ,而凋亡的发生也与Bax基因、Bcl 2基因表达呈显著正、负相关性。在缺氧复氧组中 ,未发现相关性。 结论 缺氧复氧可致胎鼠大脑皮层神经细胞发生凋亡 ;缺氧复氧所引起Bcl 2基因表达增高 ,Bax基因表达降低 。

Objective The study is to investigate the dynamic expression of Bcl 2 and Bax protein in the apoptosis of primary cultured rat cortical neurons following hypoxia/reoxygenation(H/R)and its relation with apoptosis. Methods The cortical neurons of E16 17 days fetal rat was primarily cultured.The apoptosis model of primary cultured cortical neurons following H/R was established by using TUNEL staining and flow cytometry.The dynamic expression of Bcl 2 and Bax protein at different H/R time was investigated with immunohistochemical method. Results 1.H/R can cause apoptosis of primary cultured rat cortical neurons.In the experiment of H 2R 0,H 4R 0,H 6R 0,H\-8R\-0 and H 2R 18 ,H 4R 18 ,H 6R 18 ,H 8R 18 ,the apoptosis cells occurred after 4 hour hypoxia.The apoptosis cell increased with the time,and reaching peak value at H 8H 18 .2.In the experiment of solo hypoxia group,the expression of Bcl 2 protein decreased with hypoxia time,but Bax increased.They showed obviously negative correlationship.Furthermore,the rate of apoptotic cell also showed obviously negative correlation with Bcl 2 and positive correlation with Bax.However,in hypoxia/reoxygenation group,no correlation was found. Conclusion The apoptosis of primary cultured rat cortical neurons could be induced by H/R.That hypoxia causes the increase of the expression of Bcl 2 protein and the decrease of the expression of Bax protein could be one of the mechanisms of apoptosis.