[Effects of shear stress on expression of plasminogen activator (tPA and uPA) in cultured kidney proximal tubular epithelial cells and its significance].

In this study, we assessed the effects of shear stress on the expression of plasminogen activator(tPA and uPA) mRNA in cultured NRK-52E cells (a kidney proximal tubular epithelial cell line of normal rat origin) and investigated the mechanism of tubulointerstitial extracellular matrix (ECM) remodeling in the early stage of diabetic nephropathy (DN). The cultured NRK-52E cells were exposed to shear stress of 5 and 10 dyn/cm2 for 1, 3 and 6 hours respectively. Semi-quantity RT-PCR was used to detect the expression of tPA and uPA mRNA. Shear stress down-regulated the expression of tPA and uPA mRNA in cultured NRK-52E cells in a magnitude and time-dependent way. The results suggested that the increased tubular shear stress in the early-stage of DN could decrease the expression of tPA and uPA in renal proximal tubular cells, lead to the reduction of tubulointerstitial fibrinolytic activity and involve in the remodeling of ECM.