Fig. 2. p90RSK regulated TGF-β1-induced myofibroblast differentiation. A: Human lung fibroblasts were treated with increasing concentrations of FMK for 1 hour and then incubated with TGF-β1 (2 ng/ml) for 24 hours. α-SMA, calponin, SM22α, p-p90RSK, p90RSK, and tubulin protein levels were assessed by immunoblotting. Bar graphs present the densitometric results of Western blot bands. ANOVA: *, p<0.05; **, p<0.01 versus CON. ^†, p<0.05, ^††, p<0.01 versus TGF-β1 treated. B: Human lung fibroblasts were transduced with Ad-DN-RSK or Ad-LacZ for 1 day and treated with TGF-β1 (2 ng/ml) for 24 hours. Protein levels were assessed by immunoblotting with specific antibodies against α-SMA, calponin, SM22α, p-p90RSK, p90RSK, and tubulin. Bar graphs represent the densitometric results of western blot bands. Results are presented as the means±SDs of three independent experiments. (*, p<0.05 versus CON. ^†, p<0.05, ^††, p<0.01 versus TGF-β1 treated. (n=3).