Participation of C/EBPβ in TGF-β-induced CTGF expression in human lung epithelial A549 cells. (A) A549 cells were transfected with 50 nM control siRNA (con siRNA) and C/EBPβ siRNA (50 nM) for 48 h before they were stimulated with TGF-β (10 ng/mL) for an additional 6 h. CTGF and α-tubulin levels were detected in cell lysates through Western blotting. Results are presented as mean ± SEM of four independent experiments. * p < 0.05, compared with TGF-β plus the control siRNA group. (B) Cells were stimulated with TGF-β (10 ng/mL) for 0–60 min, after which the levels of C/EBPβ phosphorylation and C/EBPβ in cell lysates were immunodetected with specific antibodies. Results are presented as mean ± SEM of five independent experiments. * p < 0.05, compared with the control group without TGF-β treatment. (C) Incubated cells were stimulated with TGF-β (10 ng/mL) for 20 min and detected using the ChIP assay, as mentioned in the “Materials and Methods” section. The typical traces indicated the three independent experiments that yielded similar results. Results are presented as mean ± SEM of three independent experiments. * p < 0.05, compared with the control group without TGF-β treatment.