Fig. 1

Amphiregulin (AREG) is involved in transforming growth factor (TGF)-β-induced cellular communication network factor 2 (CCN2) and fibronectin expression in A549 human lung epithelial cells. A Lung tissue sections from ovalbumin (OVA)- or phosphate-buffered saline (PBS)-treated C57B/L6 mice were observed by immunofluorescence staining. Representative images of AREG (red) and fibronectin (green) from PBS- (n = 6) and OVA-treated (n = 5) mice. Nuclei were detected by 4′,6-diamidino-2-phenylindole (DAPI) staining (blue) (original magnification, 20 ×). Quantification of (B) fibronectin and (C) AREG from Fig. 1A. Data are presented as the mean ± SEM (PBS, n = 6 and OVA, n = 5). *p < 0.05, relative to PBS-treated mice. D A549 cells were stimulated with transforming growth factor (TGF)-β (10 ng/ml) for 0 ~ 24 h. Amounts of AREG in supernatants were investigated by an AREG-ELISA. Results are presented as the mean ± SEM, *p < 0.05, n = 3, compared to the control group. Furthermore, cells were transfected with 50 nM of control siRNA (con siRNA), Smad3 siRNA, or AREG siRNA for 24 h, and then stimulated with TGF-β (10 ng/ml) for the indicated time. Levels of (E and  F) AREG, α-tubulin, (G) CCN2, α-tubulin, (H) fibronectin, and α-tubulin in cell lysates were detected by immunoblots. The results are expressed as the mean ± SEM, *p < 0.05, n = 3, relative to the TGF-β-stimulated with the control siRNA group