脑源性神经营养因子对脑梗死大鼠神经细胞凋亡及Bcl-2、Bax蛋白表达的影响

目的 探讨侧脑室内立体定向注射脑源性神经营养因子(BDNF)对脑梗死大鼠神经细胞凋亡及Bcl-2、Bax蛋白表达的影响.方法 32只SD大鼠成功制作大脑中动脉闭塞模型,随机分为BDNF组(n=16)和对照组(n=16),在两组大鼠侧脑室内分别注射10μ1 BDNF溶液(0.5 μmol)和10μl磷酸盐缓冲液(PBS液).注射2周后,2组大鼠分别行神经功能严重性评分(mNSS)及梗死面积测定,应用免疫组化染色、Western blot分析脑组织Bcl-2、Bax蛋白的表达,Tunel检测细胞凋亡.结果 与对照组比较,BDNF组脑梗死面积缩小,神经细胞凋亡数少,Bax蛋白表达低,Bcl-2蛋白表达高,短期内神经功能恢复好,差异均具有统计学意义(P＜0.05).结论 BDNF可能通过调节Bcl-2、Bax蛋白表达,减少神经细胞凋亡,改善脑缺血大鼠的功能.

Effect of brain-derived neurotrophic factor on neural cell apoptosis and expressions of Bcl-2 and Bax in the rat with cerebral infarction

Objective To investigate the effect of stereotaxical injection of brain-derived neurotrophic factor （BDNF） into the lateral ventricle on neuron apoptosis and expressions of Bcl-2 and Bax in rats with cerebral infarction. Methods The middle cerebral artery occlusion model was successfully established in 32 SD rats, which were randomly and equally divided into BDNF group and control group. 10 p.l BDNF solution （0.5 p~mol） and 10 p,l phosphate buffered saline were injected into the lateral ventricle of rat in BDNF and control groups respectively. The modified neurological severity score （mNSS） and cerebral infarction area were calculated 2 weeks after injection. The expressions of Bcl-2 and Bax were detected by immunohistochemistry and Western blotting. The cell apoptosis was detected by Ttmel. Results Compared with the control group, the infarct area was smaller, the apoptotic neural cells was fewer and the expression of Bax decreased, while the expression of Bcl-2 was more significantly increased and neural function was more significantly improved in short term in BDNF group （P 〈 0.05）. Conclusions BDNF can improve the neural function of rats with cerebral ischemia probably by regulating the expressions of Bcl-2 and Bax, and reduce nerve cell apoptosis.