Changes of uPA and PAI-1 expressions on cultured rat mesangial cells transfected with Smad3 cDNA

Objective: To elucidate the mechanism of the role of TGF-β in the development of glomerulosclerosis by observing urokinase-type plasminogen activator(uPA)and plasminogen activator inhibitor-1(PAI-1)expressions on cultured rat mesangial cells(MsC)transfected with Smad3 cDNA.Methods: Lipofectin method was used to transfect Smad3 cDNA into rat MsC,RT-PCR and Western blot analysis for detecting Smad3 mRNA and protein expression level.The expressions of uPA and PAI-1 were also determined by RT-PCR and Western blot. Results: Overexpression of Smad3 on two transfected MsC clones(Th-8,Th-15)were successfully established.Two MsC clones showed decreased expressions of uPA mRNA and its protein accompanied with increased synthesis of PAI-1 mRNA and its protein. Conclusion: It is possible that TGF-β mediates the development of glomerulosclerosis by upregulating Smad3 expression,which decreasing the expression of uPA and increasing the synthesis of PAI-1.