Figure 5
Role of TGF-β1-dependent pathway in the RA-SF-induced α-SMA expression. (A) Serum-starved hASCs were treated with 1 % RA-SF or 0.2 ng/ml TGF-β1 for 4 days in the absence or in the presence of 10 µM SB-431542. (B) Serum-starved hASCs were infected with control or lentiviral TGF-β type I receptor-specific shRNA. The mRNA levels of TGF-β type I receptor (TGFβR1) were determined by semi-quantitative RT-PCR. (C) Lentiviral infected cells were then exposed to vehicle, 1% RA-SF or 0.2 ng/ml TGF-β1. (D) SF of normal donors or RA patients was subjected to ELISA for determination of the concenturations of TGF-β1. In the statistical analysis of TGF-β1 concentrations, box and whisker plots represent median values, 25-75% range, and 10-90% range. *, P < 0.05 vs. normal. (E) 1% RA-SF or 0.2 ng/ml TGF-β1 were incubated with 0.2 µg/ml anti-TGF-β1 or control antibodies for 1 h, and supernatants were collected after precipitation of the immune complexes for depletion of TGF-β1. hASCs were treat with the TGF-β1-depleted supernatants for 4 days. The expression levels of α-SMA and GAPDH were determined by Western blot. Representatives of three independent experiments are shown.
