PDGF对大鼠肾小球系膜细胞表达纤维连接蛋白和PAI-1的影响

目的：探讨血小板源性生长因子fPDGF）对体外培养的大鼠肾小球系膜细胞表达纤维连接蛋白（VN）和纤溶酶原激活物抑制剂-1（PAI-1）的影响。方法：分别以0、5、10ng／rnl的PDGF—BB刺激体外培养的大鼠肾小球系膜细胞12、24、48h．以ELISA法检测培养上清中FN水平，发色底物显色法检测PAI-1的活性；以0、5、10ng／ml的PDGF—BB刺激大鼠系膜细胞24h和10ng／ml PDGF-BB分别作用0、12、24、48h。RT-PCR方法检测系膜细胞PAI-1 mRNA的表达。结果：PDGF-BB在10ng／ml以内随浓度增加可促进大鼠肾小球系膜细胞PAI-1 mRNA和FN表达．在48h内其表达呈时间依赖性。而PAI-1活性在24h时表达最高，以后逐渐下降、结论：PDGF-BB可上调FN和PAI-1及其mRNA表达．提示PDGF可能通过促进细胞外基质合成并抑制其降解而导致肾小球细胞外基质的积聚。

Effects of PDGF-BB on the expression of fibronection and plasminogen activator inhibitor-1 in glomerular mesangial cells cultured in vitro in rats

Objective: To investigate the effects of PDGF-BB on the expression of fibronection (FN) and plasminogen activator inhibitor-1(PAI-1) in glomerular mesangial cells cultured in vitro in rats. Methods: The cultured mesangial cells were stimulated by PDGF-BB with a concentration of 0, 5 and 10 ng/ml for 0,12,24,48 hours,respectively. The quantity of FN and the activity of PAI-1 in cultured supernatants were determined by ELISA and spectrophotoetric methods. The expression of PAI-1 mRNA of mesangial cells was assayed by semi-quantitative RT-PCR when the cultured mesangial cells were stimulated by 0,5 and 10ng/ml PDGF-BB for 24 hours, and 10 ng/ml PDGF-BB for 0,12,24,48 hours. Results: PDGF-BB with a concentration of 0,5 and 10ng/ml for 0,12,24,48 hours significantly increased the expression of PAI-1mRNA and the level of FN in the supernatants in rats mesangial cells in a dose-and time-dependent manner. The activity of PAI-1 was increased significantly and reached the maximum at 24 hours,then subsequently decreased gradually. Conclusion: PDGF-BB can up-regulate the expression of FN and PAI-1 in mRNA and protein level.PDGF-BB might contribute to glomerular sclerosis by promoting the synthesis of extracellular matrix and inhibiting the degradation of it.