Figure 4

TWEAK had no additional effect on TGF-β1-induced Smad2 phosphorylation. Confluent monolayers of BEAS-2B cells were cultured for the indicated time points in the absence (conrol or DMSO as vehicle) or presence of SB43125 (10 μM) and treated with TGF-β1 (10 ng/ml), TNF-α (10 ng/ml), TWEAK (100 ng/ml), or TGF-β1 in combination with TNF-α or TWEAK, as indicated. Whole cell lysates were prepared at the indicated time points (A) and 1 h (B) after treatment. Phosphorylation of Smad2 was examined by western blotting. Densitometry of pSmad2 signals was normalized against total Smad2 signals. Data represent the means ± SD of three independent experiments. ^* p < 0.05 compared with the untreated culture. ^† p < 0.05 compared with TGF-β1 alone. ^§ p < 0.05 compared with vehicle.