胰岛素对大鼠肾系膜细胞增殖及损伤和PAI-1合成的影响

Effect of Insulin on Proliferation,Injury and the Expression of PAI-1 in Rat Glomerular Mesangial Cells

目的:观察不同浓度胰岛素对体外培养的大鼠肾系膜细胞(GMC)损伤、增殖和纤溶酶原激活物抑制剂1(PAI-1)的影响。方法:用不同浓度胰岛素刺激GMC,用四甲基偶氮唑盐比色法(MTT)测定细胞增殖程度,采用全自动生化分析仪测定培养液中乳酸脱氢酶(LDH)水平显示细胞损伤,并以无胰岛素刺激组为对照;采用RT-PCR检测PAI-1mRNA表达。结果:GMC在胰岛素刺激后,细胞增殖和LDH水平在一定浓度范围内呈剂量和时间依赖性增加,高水平胰岛素可从基因水平上调系膜细胞PAI-1的表达。结论:高胰岛素水平能促进GMC增殖,造成细胞损伤,同时上调PAI-1mRNA表达,提示高胰岛素可能通过抑制细胞外基质降解,参与肾小球纤维化的过程。

Objective：To observe the effect of insulin on proliferation,injury and the expression of plasminogen activator inhibitor- 1 in rat glomerular mesangial cells （GMC） cultured in vitro, Methods：Different concentrations of insulin were added to cultured GMC cells. The capacity of proliferation of GMC was assessed by tetrazoliurn salt colorimetry assay （MTT assay） . The level of LDH was detected in culture medium in every group to prove the injury of GMC. The expression of PAl - 1 mRNA of mesangial cells was assayed by semi - quantitative RT- PCR when the cultured mesangial cells were stimulated after 12 hours. Results： When GMC was stimulated by insulin, the proliferation and LDH levels of supernatants increased according to the concentration of insulin in a time - dependent manner. The concentration of 250μU/ml and 500μU/ml insulin significantly increased the expresion of PAl - 1 mRNA. Conclusion：High concentration of insulin can enhance the proliferation of GMC and induce its injury. It also can upregulate the expression of PAl- 1 mRNA. High concentration of insulin might contribute to glomerular sclerosis by inhibiting the degrading of extracellular matrix.