胰岛素样生长因子-1对大鼠局灶性脑缺血再灌注后神经细胞凋亡及bcl-2、Bax蛋白表达的影响

Effects of insulin-like growth factor-1 on apoptosis and the expression of bcl-2 and Bax in rats following cerebral ischemia and reperfusion

目的 :研究胰岛素样生长因子 - 1 ( IGF- 1 )对大鼠局灶性脑缺血再灌注后神经细胞凋亡及 bcl- 2、Bax蛋白表达的影响 ,探讨 IGF- 1对脑缺血再灌注损伤的保护作用机制。方法 :制作大鼠大脑中动脉缺血再灌注模型。将 30只 Wistar雄性大鼠随机分为假手术组、缺血组及 IGF- 1治疗组。于缺血 1 0 min后经尾静脉给予 IGF- 1 1 0 μg,应用 TTC染色观察梗死灶体积 ,应用免疫组化染色和 TUNEL法检测 bcl- 2、Bax蛋白表达及神经凋亡细胞。结果 :与缺血组比较 ,IGF- 1治疗组梗死体积明显减少 ( P<0 .0 1 ) ,凋亡细胞数明显减少 ( P<0 .0 1 ) ,bcl- 2蛋白表达明显升高 ( P<0 .0 1 ) ,Bax蛋白表达明显降低 ( P<0 .0 1 )。结论 :IGF- 1通过增加 bcl- 2蛋白表达 ,减少 Bax蛋白表达 ,减少神经细胞凋亡 ,对脑缺血再灌注损伤起保护作用。

Objective:To study the effects of IGF-1 on apoptosis and the expression of bcl-2 and Bax following cerebral ischemia and reperfusion and evaluate the protecting mechanism of IGF-1.Methods:The model of middle cerebral artery occlusion(MCAO)and reperfusion was set up. Thirty Wistar male rats were randomly divided into sham-operated group, ischemic group and IGF-1 treated group. IGF-1 of 10μg was injected via caudal vein 10 minutes after the artery occlusion. The Brain sections were used for TTC staining and TUNEL staining as well as bcl-2 and Bax immunohistochemical staining. Results: Compared with ischemic group, the infarct volumes, the number of apoptotic cells and the expression of Bax positive cells in IGF-1 treated group were decreased significantly(P<0.01).The expression of bcl-2 positive cells was increased significantly(P<0.01). Conclusion: IGF-1 can decrease apoptosis by up-regulating bcl-2 and down-regulating Bax.