[Interaction between TGF-beta1/Smad pathway and ERK pathway in vascular smooth muscle cells].

Objective:To investigate if the interaction between TGF-β1/Smad pathway and ERK pathway in vascular smooth muscle cells exists.Methods:The rat arota was removed.The primary VSMC were isolated and cultured in vitro,then the VSMC were divided into four groups:①control group,②TGF-β1 group,③ERK blocking agent group,④TGF-β1+ ERK blocking agent group.The expression of Smad2/3,ERK1/2 proteins,the content of phosphorylated ERK1/2 and Smad2/3 proteins were detected by Western blot,and the expression of Smad2/3 mRNA was detected by reverse transcription-polymerase chain reaction(RT-PCR).Results:①In contrast to control group,the content of phosphorylated Smad2/3 and phosphorylated ERK1/2 proteins in TGF-β1 group was increased(P0.05),that in ERK blocking agent group was decreased(P0.05).There was no difference between control group and TGF-β1+ERK blocking agent group.Compared with TGF-β1 group,the contents of phosphorylated Smad2/3 and phosphorylated ERK1/2 proteins in TGF-β1+ERK blocking agent group was decreased(P0.05).There was no difference in the expression of Smad2/3 and ERK1/2 proteins among different groups.②There were no differences in expression of Smad2 and Smad3 mRNA among different groups.Conclusion:①TGF-β1 can induce Smad2/3 proteins to be phosphorylated dependent on the activated ERK pathway.②ERK pathway does not effect the expression of Smad2/3 at the level of protein and mRNA.