中文摘要：

目的 探讨PPAR-γ在LDL诱导的系膜细胞增殖和基质硬化中的作用。方法 以体外培养的大鼠系膜细胞为研究对象，应用不同浓度的LDL刺激系膜细胞。应用MTT法检测细胞增殖；应用RT-PCR的方法检测LDL对MMP-2、TIMP-2、PPAR-γmRNA表达的影响；应用Western Blot的方法检测LDL对MMP-2、TIMP-2、PPAR-γ蛋白表达的影响。结果 以浓度为3．125～100μg／ml的LDL刺激系膜细胞。可促进系膜细胞的增殖，在LDL3．125～50μg／ml的浓度范围内，系膜细胞的增殖和LDL的浓度呈正相关（r=0．865。P〈0．05）；以浓度为12．5～100μg／ml的LDL刺激系膜细胞。可下调MMP-2／TIMP-2mRNA和蛋白的表达（P〈0．01）；以浓度为6．25～100μg／ml的LDL刺激系膜细胞。可下调PPAR-γmRNA和蛋白的表达（P〈0．01）。结论 在LDL诱导下。PPAR-γ的下调促进了系膜细胞的增殖和系膜基质的增生。

英文摘要：

Objective To study the effects of PPAR-γ in the progress of the rat mesangial cell proliferation and matrix fibrosis induced by low-density lipoprotein. Methods Cultured rat mesangial cells were performed with LDL of different concentration in vitro. Cell viability was measured by MTT assay; the expression of MMP-2, TIMP-2, PPAR-γ mRNA was measured by RT-PCR; the expression of MMP-2, TIMP-2, PPAR-γ protein was measured by Western Blot. Results The proliferation of mesangial cells were promoted by LDL of the concentration from 3. 125 to 100μg/ml, when the LDL concentration was from 0 to 50μg/ml, the proliferation of mesangial cell was correlated with LDL concentration（r = 0.865, P 〈 0.05）. The expression of MMP-2/ TIMP-2 mRNA and protein were downregulated by LDL of the concentration from 12.5 to 100μg/ml（P 〈 0.01）. The expression of PPAR-γmRNA and protein were downregulated by LDL of the concentration from 6.25 to 100μg/ml（P 〈0.01）. Conclusion The down-regulation of PPAR-γ expression elevated the proliferation of mesangial cells and extracellular matrix induced by LDL.