珍龙醒脑对血管性痴呆大鼠海马CA1区自噬相关蛋白表达的影响

Effect of Zhenlongxingnao on the Expression of Autophagy-related Protein in Hippocampal CA1 region of Rats with Vascular Dementia

目的:探讨珍龙醒脑对血管性痴呆大鼠海马CAI区自噬相关蛋白mTOR、Beclin1表达和自噬活性微管相关蛋白1轻链3 (LC3)Ⅱ与Ⅰ的比值的影响。方法:72只SD大鼠随机分为假手术组、模型组、珍龙醒脑组,每组又分为造模术后1周、2周、4周和8周4个亚组,每组6只。采用双侧颈总动脉夹闭法制备血管性痴呆模型,术后珍龙醒脑200 mg/kg灌胃,1次/d,各亚组分别给药1周、2周、4周和8周。免疫组化法检测各组大鼠海马CAI区mTOR与Beclin1表达变化,Westernblot法检测自噬活性微管相关蛋白1轻链3 (LC3)Ⅱ与Ⅰ的比值。结果:与假手术组比较,模型组和珍龙醒脑组各时间段海马CA1区mTOR与Beclin1表达均上调(P均<0.01),LC3Ⅱ/LC3Ⅰ比值明显升高(P均<0.01),且在术后第4周达到高峰值。与模型组比较,珍龙醒脑组各时间段大鼠海马组织mTOR蛋白表达均上调(P均<0.01),Beclin1蛋白表达减少(P均<0.01),LC3Ⅱ/LC3Ⅰ比值下降(P<0.05或P<0.01)。结论:珍龙醒脑通过激活mTOR信号通路,抑制自噬相关蛋白LC3、Beclin1表达,减轻自噬性损伤,发挥对血管性痴呆治疗作用。

Objective:To investigate the effects of Zhenlong Xingnao on the expression of autophagy-related proteins mTOR,Beclinl and LC3 II/LC3 I in hippocampal CA1 region of rats with vascular dementia.Methods:72 SD rats were randomly divided into sham operation group,model group and Zhenlong Xingnao group.Each group was divided into 4 subgroups of 1,2,4 and 8 weeks after operation,6 in each group.The VD model was prepared by four-vessel occlusion method.After the operation,Zhenlong Xingnao 200 mg/kg was intragastrically administered once a day,and each subgroup was administered for 1 week,2 weeks,4 weeks and 8 weeks respectively.The expressions of mTOR and Beclinl in hippocampal CA1 region of each group were detected by immunohistochemistry.The ratio of LC3 II/I was detected by Western-blot method.Results:Compared with the sham operation group,the expressions of mTOR and Beclinl in the hippocampal CA1 area of the model group and the Zhenlong Xingnao group were up-regulated(P<0.01),and the LC3 II/LC3 I ratio was significantly increased(P<0.01).Which all reached maximum level at 4 week after operation.Compared with the model group,the expression of mTOR protein in hippocampus of rats in Zhenlong Xingnao group was up-regulated(P<0.01),Beclinl protein expression was decreased(P<0.01),and LC3 II/LC3 I ratio decreased(P<0.05 or P<0.01).Conclusion:Zhenlong Xingnao has a therapeutic effect on vascular dementia.It can activate the mTOR signaling pathway,inhibit the expression of autophagy-related proteins LC3 and Beclinl,and reduce autophagic damage.