目的:探讨胞膜小凹(caveolae)在高糖(HG)诱导大鼠肾小球系膜细胞(MCs)细胞外基质(extra-cellular matrix,ECM)表达过程中的作用.方法:传代培养的大鼠MCs同步化后分为:(1)正常糖组；(2)HG组；(3)HG+甲基-β-环糊精(β-MCD)组;(4) HG+ β-MCD+胆固醇组.用Western blotting检测小凹蛋白1(Cav-1)、磷酸化小凹蛋白1 (p-Cav-1-Y14)和Ⅰ型胶原(Col Ⅰ)蛋白的表达水平,用实时定量PCR检测细胞中Cav-1 mRNA表达变化,用ELISA方法检测上清中纤维连接蛋白(FN)的蛋白含量.结果:(1)高糖状态下,系膜细胞FN和Col Ⅰ蛋白表达水平均显著增加(均P＜0.05).(2)高糖培养显著增加p-Cav-1-Y14水平(P＜0.01),而对Cav-1 mRNA及蛋白表达无明显影响(P＞0.05).(3) β-MCD预处理抑制了高糖诱导的p-Cav-1-Y14升高(P＜0.01)及FN表达(P＜0.05),但对高糖诱导的Col Ⅰ表达无影响；β-MCD的作用可被胆固醇抑制.结论:高糖可显著增加系膜细胞1型胶原及纤维连接蛋白的合成.高糖诱导的纤维连接蛋白合成与C av-1磷酸化水平增加有关.%AIM: To investigate the role of caveolae in high glucose ( HG ) -induced extracellular matrix (ECM) production in rat mesangial cells (MCs). METHODS: Synchronized rat MCs were divided into normal glucose group, HG group, HG + methyl-g-eyelodextrin (3-MCD) group and HG + β-MCD + cholesterol (Choi) group. Western blotting was used to detect the protein expression of caveolin-1 (Cav-1 ) , phosphorylated caveolin-1 (p-Cav-l-Y14) and collagen type 1 (Col I). The mRNA expression of Cav-1 was determined by real-time PCR. ELISA was used to measure the level of fibronectin (FN) in the supernatant. RESULTS; High glucose significantly increased the expression of FN and Col I. In HG 12, 24 and 48 h groups, the mRNA and protein levels of Cav-1 were not significantly different from those in HG 0 h group, whereas the level of p-Cav-l-Y14 was significantly increased. β-MCD significantly attenuated HG-induced elevation of p-Cav-l-Y14 and FN production, but had no effect on HG-induced Col I expression. All these responses to β-MCD were abolished by Choi. CONCLUSION: High glucose significantly increases the production of Col I and FN in rat MCs. FN production induced by high glucose is mediated by p-Cav-1-Y14.
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