Fig. 5

Involvement of mitogen-activated protein kinase kinase kinase 1 (MEKK1) in CXCL12-caused connective tissue growth factor (CTGF) expression in WI-38 cells. a After transfected with control siRNA (Con siRNA 100 nM) or MEKK1 siRNA (100 nM) for 24 h, the WI-38 cells were exposed to CXCL12 (10 ng/ml) for additional 2 h. Protein levels of CTGF or α-tubulin in cell lysates were determined by western blot. Statistics are showed as the mean ± S.E.M. of four separate experiments. * p < 0.05, compared with CXCL12 treatment without MEKK1 siRNA. b WI-38 cells were exposed to CXCL12 (10 ng/ml) for 0~ 20 min. Protein levels of phospho-MEKK1 Thr261 or MEKK1 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