Sal B blocked α-SMA expression induced by TGF-β1 in HK-2 cells. HK-2 cells were cultured in complete medium containing 5% FBS for 18 h. Thereafter, the cells were kept in serum-free medium or treated with (1) 2.5 ng/ml TGF-β1, (2) 2.5 ng/ml TGF-β1 plus 1 μM of Sal B, (3) 2.5 ng/ml TGF-β1 plus 10 μM of Sal B, (4) 2.5 ng/ml TGF-β1 plus 10 μM of SB-431542 for 24 h. (A) Immunofluorescence staining (×200) shows the increased labeling intensity of α-SMA observed after TGF-β1 treatment, while its increase becomes reversed after 1 μM and 10 μM Sal B and SB-431542 treatments. The blue-colored stain is nuclear counterstaining with Hoechst 33258. (B) Western blot analysis for α-SMA. α-SMA expression was increased when the cells were exposed to TGF-β1, whereas treatment with 1 μM and 10 μM Sal B and SB-431542 significantly attenuated the up-regulation of α-SMA by TGF-β1. (C) Graphic presentation of the relative expression of α-SMA. The values are represented as 100% vs. GAPDH. **P <0.01 vs. control; # #P < 0.01 vs. TGF-β1.
Wang et al. BMC Cell Biology 2010 11:31 doi:10.1186/1471-2121-11-31