黄芪甲苷抑制粘着斑激酶磷酸化改善高糖环境下的足细胞黏附能力的研究

Astragaloside IV improves podocyte adhesion by inhibition of FAK phosphorylation

目的观察黄芪甲苷(AS-Ⅳ)对高糖环境下足细胞黏附能力的影响,并探讨其作用机制。方法将条件永生化小鼠足细胞分为正常对照组、高糖组、高糖+低剂量AS-Ⅳ组、高糖+高剂量AS-Ⅳ组,采用细胞黏附荧光定量试剂盒检测足细胞黏附能力,白蛋白流量率检测法测定足细胞单层屏障功能,Western blot法检测粘着斑激酶(FAK)与磷酸化FAK(p-FAK)表达。观察并比较4组足细胞黏附能力、单层屏障功能、FAK与p-FAK表达情况。结果 4组足细胞黏附能力、单层屏障功能比较差异均有统计学意义(均P<0.05),高糖环境会降低足细胞的黏附能力、单层屏障功能,而AS-Ⅳ可明显增强高糖环境下足细胞的黏附能力、单层屏障功能,且对黏附能力的影响具有时间和剂量依赖性。4组足细胞FAK表达情况比较无统计学差异(均P>0.05),而p-FAK表达情况比较有统计学差异(均P<0.05);高糖环境对足细胞FAK表达无明显影响,但会明显增加FAK磷酸化;AS-Ⅳ可明显抑制高糖环境下足细胞FAK蛋白磷酸化,且该作用具有时间和剂量依赖性。结论 AS-Ⅳ或通过抑制FAK磷酸化改善高糖环境下足细胞的黏附能力。

Objective To investigate the effect of astragaloside IV (AS-IV) on podocyte adhesion function under high glucose circumstances and explore its mechanisms. Methods Conditionally immortalized mouse podocytes were divided into normal control group, high glucose group, high glucose with low dose AS-IV group and high glucose with high dose AS-IV group. Podocyte adhesion was measured by fluorescence. The filtration barrier function of podocyte monolayer was measured by albumin influx. The expression of focal adhesion kinase (FAK) and phosphorylated FAK (p-FAK) were measured by Western blot. The results of 4 groups were compared. Results The adhesion ability and monolayer barrier function of podocytes among 4 groups were significantly different (all P<0.05). Compared with normal control group podocyte adhesion with basement membrane complex and monolayer filtration barrier function reduced significantly under high glucose circumstances and were improved by AS-IV. AS-IV attenuated podocyte adhesion reduction induced by high glucose in a time and dose dependent manner. The protein expression of FAK had no significant difference among 4 groups (all P>0.05), but there were significant differences in p-FAK expression among 4 groups(all P<0.05). The p-FAK expression in podocytes was increased significantly under high glucose circumstances, and was inhibited by AS-IV time- and dose-dependently. Conclusion The study indicates that AS-IV may improve podocyte adhesion function in diabetic nephropathy, which may be associated with the inhibition of FAK phosphorylation.