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.