Fig. 4

Involvement of c-Jun N-terminal kinase (JNK) in CXCL12-induced SMAD3 activation in human lung fibroblasts (WI-38). a Cells were exposed to 10 ng/ml of CXCL12 for 0~ 60 min. Protein levels of phospho-JNK T183/Y185 or JNK in cell lysates were determined by western blot. Statistics are showed as the mean ± S.E.M. of three separate experiments. * p < 0.05, compared with control without CXCL12 treatment. b WI-38 cells were treated with 3~ 30 μM of SP600125 for 20 min before cells were exposed to CXCL12 (10 ng/ml) for additional 20 min. Protein levels of phospho-SMAD3 Ser208 and SMAD3 in cell lysates were determined by western blot. Statistics are showed as the mean ± S.E.M. of three separate experiments. * p < 0.05, compared with CXCL12 treatment without SP600125. c After transfected with 0.5 μg of SMAD3-Luc and 0.2 μg of pBK-CMV-Lac Z for 24 h, the WI-38 cells treated with 10 μM of SP600125 for 20 min before cells were exposed to CXCL12 (10 ng/ml) for additional 16 h. Luciferase activity assay were described in Fig. 2b. Statistics are showed as the mean ± S.E.M. of three separate experiments. * p < 0.05, compared with CXCL12 treatment