Figure 4

TGF-β-dependent activation of c-JNK was independent of Smad3 activation. A. Serum-deprived RMF-EG cells were incubated with 5 ng/ml of TGF-β from 10 to 90 min. The levels of phosphorylated and total JNK were evaluated by western blot. B. RMF-EG cells were pre-treated with 3 μM SIS3, specific inhibitor of Smad3, and stimulated with 5 ng/ml TGF-β as in B. c-JNK and Smad3 activation were evaluated by western blot.