Figure 11.

The effect of the transient overexpression of Smurf1/Smurf2 on the levels of TβRI protein in normal and scleroderma fibroblasts. Cells were transfected with 1 μg each of the Smurf1 and Smurf2 expression vectors or the corresponding empty constructs. After a 48-hour incubation, the levels of TβRI or exogenous overexpressed Smurf1/Smurf2 were determined by Western blot analysis using anti-TβRI Ab or anti-Flag Ab, respectively. In some experiments, cells were treated with TGF-β1 (2 μg/ml) for the last 24 hours. One representative of five independent experiments is shown (a). The protein levels quantitated by scanning densitometry are shown relative to those in untreated normal fibroblasts transfected with empty vector (100 AU) (b). Data are expressed as the mean ± SD of five independent experiments.