VEGF对小鼠足细胞黏附性的影响及PI3K/Akt信号通路在其中的作用

Role of VEGF and associated PI3K/Akt signaling pathway on the adhension of mouse podocyte

目的探讨血管内皮生长因子(VEGF)对小鼠足细胞黏附性的影响及整合素连接激酶(ILK)、PI3K/Akt信号通路在其中的作用。方法培养小鼠足细胞MPC5,予不同含量VEGF(0、4、8、16、32μg/L)分别作用24 h,采用细胞计数法和己糖胺酶分析法观察足细胞黏附性的变化,实时荧光定量PCR和免疫印迹检测ILK表达的变化,并观察PI3K/Akt信号通路的改变。其次随后予以PI3K抑制剂Wortmanin预处理足细胞后,观察VEGF对足细胞黏附性及ILK表达的影响。结果与对照组相比,经32μg/L VEGF处理的足细胞黏附性明显下降(P<0.05),ILK mRNA和蛋白表达水平升高(P<0.05),同时PI3K/Akt通路激活(P<0.05);予PI3K抑制剂渥曼青霉素预处理足细胞后,可减轻VEGF引起的ILK表达升高,逆转VEGF引起的足细胞黏附性下降。结论 VEGF可通过引起PI3K/Akt通路激活,上调ILK表达,导致足细胞黏附性的下降和脱落增加。

Objective To investigate the influence of vascular endothelial growth factor （VEGF） on the adhesive capacity of podocytes and the role of PI3K/Akt pathway and integrin linked kinase （ILK）. Meth- ods Firstly, podocytes were incubated with VEGF （0 μg/L, 4 μg/L, 8 μg/L, 16 μg/L and 32 μg/L） for 24 h followed by adhesive capacity of podocytes assessed by cell counting and hexosaminidase assay. Real-time PCR and western blotting were used to detect the mRNA and protein levels of ILK. Western blotting was per- formed to analyze the activation of PI3K/Akt signaling pathway. Secondly, Podocytes were treated with VEGF with or without PI3K inhibitor, wortmannin for 24h and analyzed the adhesive capacity of podocytes and ILK expression was analyzed. Results （1）Compared to control group, VEGF （32μg/L） down-regulated adhens- ive capacity of podocytes （P 〈 0. 05）, up-regulated levels of ILK mRNA and protein （P 〈 0.05 ） accompanied with the activation of PI3 K/Akt signaling pathway （P 〈 0. 05 ） ; （2） Blockade of PI3K/Akt pathway by wort- mannin alleviated the effect of VEGF on the expression of ILK and adhesion of podocytes. Conclusion VEGF can inhibit adhesive capacity and up-regulate ILK synthesis in podocytes through PI3K/Akt signaling pathway.