β淀粉样蛋白25-35对大鼠星形胶质细胞自噬的影响

Effects of Aβ on autophagy of astrocytes in rat

目的:探究β淀粉样蛋白25-35(Aβ25-35)对大鼠星形胶质细胞自噬的影响及机制。方法:培养新生SD大鼠星形胶质细胞,免疫荧光鉴定纯度达95%后分为空白对照组、Aβ25-35处理组。采用Cell Counting Kit-8方法检测大鼠星形胶质细胞的活力,采用Western Blot法检测大鼠星形胶质细胞LC3、Beclin1、Cathepsin B以及PI3K/AKT/mTOR信号通路相关蛋白的表达水平。结果:与正常对照组相比,Aβ25-35组细胞活性增强(P <0.01);LC3-Ⅱ/LC3-Ⅰ比值增加(P <0.05);Beclin1表达增加(P <0.01);Cathepsin B表达下降(P <0.05);PI3K表达下降(P <0.05),p-AKT/AKT比值减少(P <0.05),p-mTOR/mTOR比值减少(P <0.05)。结论:Aβ25-35激活大鼠星形胶质细胞自噬同时减弱自噬溶酶体降解,可能通过PI3K/AKT/mTOR信号通路途径发挥作用。

Objective: To explore the effects and mechanism of β-amyloid 25-35 (Aβ25-35) on autophagy of rat astrocytes. Methods: Astrocytes obtained from neonatal SD rats cerebral cortex,and after immunofluorescence identification reached 95% purity,astrocytes were divided into blank control group and Aβ25-35 treatment group. The viability of rat astrocytes was assessed by using the Cell Counting Kit-8 method (CCK-8). Western Blot analysis was used to detect the expression of LC3,Beclin1,Cathepsin B and PI3K/Akt/mTOR signaling pathway related proteins. Results: Compared with the blank control group,the cell activity of Aβ25-35 treatment group increased (P < 0. 01). The LC3-Ⅱ/LC3-Ⅰratio was increased (P < 0. 05). The expression of Beclin1 was increased (P < 0. 01) and the expression of Cathepsin B was decreased (P < 0. 05). The expression of PI3K was decreased (P < 0. 05). The p-AKT/AKT ratio,p-mTOR/mTOR ratio was obviously decreased (P < 0. 05). Conclusion: Aβ25-35 activate autophagy in rat astrocytes and attenuates autolysosom degradation,possibly through the PI3K/AKT/mTOR signaling pathway.