Figure 4

TGF-β1-induced MMP-9 expression is mediated through JNK1/2, but not p38 MAPK. Cells were treated with TGF-β1 (15 ng/ml) for 16 h in the absence or presence of (A) SB202190 or (B) SP600125. (C) Cells were pretreated with SB202190 (SB, 10 μM) or SP600125 (SP, 10 μM) before exposure to TGF-β1 for 6 h. Total RNA was collected and analyzed by RT-PCR. (D) Time dependence of TGF-β1-stimulated JNK1/2 phosphorylation, cells were incubated with TGF-β1 (15 ng/ml) for the indicated times. Moreover, cells were treated with TGF-β1 for 4 h in the presence of SP600125 (SP/4, 10 μM). (E) Cells were transfected with an empty vector (pcDNA3, as a control) or dominant negative mutant of p38 MAPK (Δp38) or JNK (ΔJNK) for 24 h, and then exposed to TGF-β1 for 16 h. (F) For cell migration, cells were pretreated with U0126 (10 μM) or SP600125 (10 μM) for 1 h and then incubated with TGF-β1 (15 ng/ml) for 48 h. The image is representative of three similar experiments (n = 3). The conditioned media (A, B, E) were analyzed gelatin zymorgraphy, and the whole cell lysates (D) were analyzed using an anti-phospho-JNK1/2 or anti-GAPDH (as an internal control) antibody. Data are expressed as mean ± SEM (D) or mean (A, B, C, E) of at least three independent experiments (n = 3). *P < 0.05; ^#P < 0.01, as compared with the cells exposed to vehicle (D) or TGF-β1 (A, B, D, E) alone. The figure represents one of three individual experiments.