Caffeine and Rolipram Affect Smad Signalling and TGF-β1 Stimulated CTGF and Transgelin Expression in Lung Epithelial Cells
Figure 4
Caffeine and rolipram inhibit TGF-β1 induced transgelin expression in lung epithelial cells.
A+D: The transgelin promoter luciferase construct was transiently transfected into A549 cells. Cells were then treated with TGF-β1 (10 ng/ml) and/or different concentrations of caffeine (A) or rolipram (D). Firefly luciferase activity was normalized to the activity of Renilla luciferase under control of the thymidine kinase promoter. Relative luciferase activity compared to controls is shown. * p<0.05 compared to control cells, # p<0.05 compared to TGF-β1 treated cells. B+C/E+F: A549 cells were incubated with TGF-β1 with or without different concentrations of caffeine or rolipram. Realtime PCR of transgelin mRNA was performed after 12 h (B+E) and Western blot analysis after 72 h (C+F). Relative mRNA levels of transgelin were calculated by normalizing signals to detected GAPDH mRNA (B+E) and compared to untreated cells. Means±SD of at least n = 3 independent experiments are shown. In C+F, representative immunoblots for caffeine (C; triplicates) or rolipram (F; duplicates) against transgelin and β-actin are shown. * p<0.05 compared to control cells, # p<0.05 compared to cells treated with TGF-β1.