大鼠系膜细胞增殖时S期激酶相关蛋白2表达的变化及机制

目的：探讨系膜细胞增殖时细胞周期蛋白依赖性蛋白激酶抑制物p27^kip1的降解限速蛋白——S期激酶相关蛋白2（Skp2）表达的变化及其机制。方法：原代培养的大鼠系膜细胞同步后分为无血清组、20%胎牛血清（FCS）刺激组。MTT法检测细胞增殖;实时定量PCR和Western Blot检测p27^kip1和Skp2的mRNA、蛋白表达。结果：p27^kip1在静止期系膜细胞高丰度表达,20%FCS刺激诱导细胞增殖后p27^kip1蛋白表达显著下调;实时定量PCR研究结果显示p27^kip1的mRNA表达水平差异无统计学差异,p27^kip1蛋白和mRNA表达不一致。蛋白酶体抑制剂MG-132可显著改善系膜细胞增殖时p27^kip1蛋白水平的下降。Skp2表达在静止期系膜细胞几乎检测不出,20%FCS刺激诱导细胞增殖后Skp2表达量显著上调。结论：系膜细胞Skp2表达显著上调导致p27^kip1降解增加,可能是p27^kip1蛋白水平下降、系膜细胞增殖的重要原因,为进一步阐明疾病状态下系膜细胞增殖的机制提供了新的研究靶点。

Changes of Kinase-Associated Protein 2 During S Phase of Rat Mesangial Cells Proliferation

Objective:To explore the changes of the rate-limiting enzyme in p27Akip1 degradation-S phase kinase-associated protein 2 during rat mesangial cells proliferation.Methods:Primary cultured rat mesangial cells were growth-arrested by withdrawal FCS for 24 hours and then stimulated by 20% FCS.Expression of p27kip1 and Skp2 which played a crucial role in p27kip1 degradation through ubiqutin-proteasome proteolytic pathway were detected by western blot and real-time quantified PCR.Results:The p27kip1 protein was h...