Dexamethasone Effect on the Expression of Transforming Growth Factor-β1/Smads Signaling Pathway in Benign Biliary Stricture Fibroblasts in Rodent.

OBJECTIVE

To investigate the effects of dexamethasone on transforming growth factor (TGF)-β1/Smads signaling pathway in benign biliary stricture (BBS) fibroblasts.

STUDY DESIGN

An experimental study.

PLACE AND DURATION OF STUDY

Guizhou Medical University, Guiyang, Guizhou, China, from January to August 2016.

METHODOLOGY

Fibroblasts derived from rabbit BBS model were cultured and identified, then treated by different concentration of dexamethasone (0.02, 0.1 and 0.5 mg/ml). Dexamethasone-treated cells and non-treated control groups were incubated respectively for 48 hours. Cell proliferation was assessed using cell counting kit-8. Relative mRNA expression of TGF-β1, Smad4 and Smad7 were assessed by quantitative RT-PCR. Protein expression of TGF-β1 and Smad4 were investigated by Western blotting.

RESULTS

Treatment with dexamethasone significantly inhibited the proliferation of BBS fibroblasts, significantly attenuated both the mRNA and protein expression of TGF-β1 and Smad4, and significantly up-regulated the mRNA expression of Smad7 in BBS fibroblasts (all p<0.05, 0.1-0.5 mg/ml), and exhibited in a dose-dependent manner.

CONCLUSION

TGF-β1/Smads signaling pathway may play an important role in BBS progression; dexamethasone significantly altered the expression of TGF-β1/Smads signaling pathway and significantly inhibited cell proliferation in rabbit BBS fibroblasts. Therefore, dexamethasone may be a therapeutic option for the prevention of BBS.