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

OBJECTIVE

To investigate if the interaction between TGF-beta1/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: (1) control group, (2) (TGF-beta1 group, (3) ERK blocking agent group, (4) TGF-beta1 + 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

(1) In contrast to control group, the content of phosphorylated Smad2/3 and phosphorylated ERK1/2 proteins in TGF-beta1 group was increased (P < 0.05), that in ERK blocking agent group was decreased (P < 0.05). There was no difference between control group and TGF-beta1 + ERK blocking agent group. Compared with TGF-beta1 group, the contents of phosphorylated Smad2/3 and phosphorylated ERK1/2 proteins in TGF-beta1 + ERK blocking agent group was decreased (P < 0.05). There was no difference in the expression of Smad2/3 and ERK1/2 proteins among different groups. (2) There were no differences in expression of Smad2 and Smad3 mRNA among different groups.

CONCLUSION

(1) TGF-beta1 can induce Smad2/3 proteins to be phosphorylated dependent on the activated ERK pathway. (2) ERK pathway does not effect the expression of Smad2/3 at the level of protein and mRNA.