Dexamethasone effect on the expression of transforming growth factor-[beta]1/smads signaling pathway in benign biliary stricture fibroblasts in rodent

Objective: To investigate the effects of dexamethasone on transforming growth factor (TGF)-[beta]1/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-[beta]1, Smad4 and Smad7 were assessed by quantitative RT-PCR. Protein expression of TGF-[beta]1 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-[beta]1 and Smad4, and significantly up-regulated the mRNA expression of Smad7 in BBS fibroblasts (all p