Fig. 9

Lung epithelial branching morphogenesis was severely impaired in Apc CKO embryos. a Lung epithelial branches at E13.5 were visualized by whole mount E-cadherin immunofluorescence staining. b Altered expression of Fgf10 and Bmp4 in Apc CKO lung at E11.5 was detected by real-time PCR. *P < 0.05, n = 5. c Whole mount in situ hybridization showed that Fgf10 transcript was downregulated in the mesenchymal tips of Apc CKO lung at E11.5. In contrast, Bmp4 expression was dramatically increased in the sub-mesothelial mesenchyme of Apc CKO lung. Insert: distal tip in the vibratome section. Scale bar: 100 μm. d Alterations of Fgf10 and Bmp4 expression in E13.5 Apc CKO lung were verified at the protein level by western blot. e-f Treatment of cultured human fetal lung fibroblasts HLF1 with BMP4 (50–100 ng/ml) inhibited Fgf10 expression at the mRNA level (e, measured by real-time PCR) and the protein level (f, detected by western blot). *P < 0.05, n = 5