Fibroblast Growth Factor 9 Regulation by MicroRNAs Controls Lung Development and Links DICER1 Loss to the Pathogenesis of Pleuropulmonary Blastoma
Fig 5
FGF9 overexpression in Type I PPB phenocopies ectopically expressed FGF9 in mouse lung epithelium.
(A, B, K, and L) Immunostaining for FGF9 showing increased expression in Type I PPB-associated lung epithelium and in doxycycline-induced Sftpc-rtTA, Tre-Fgf9-Ires-Gfp mouse lung. Non-diseased human lung and uninduced (no Dox) mouse lung were used as controls. (C, D, M, and N) Mesenchymal and epithelial proliferation in Type I PPB and induced mouse lung identified by immunostaining for Ki67. Inserts show higher magnification of the boxed regions. (E, F, O, and P) Immunostaining showing increased phosphorylated Erk1/2 (p-ERK) in Type I PPB and in induced mouse lung mesenchyme and reduced p-ERK in epithelium. Inserts show higher magnification of the boxed regions. (G, H, Q and R) Quantification of Ki67 immunostaining in C, D, M, and N above, showing increased in proliferation in both epithelial and mesenchymal tissues of Type I PPB (G and H) and Fgf9-induced mouse lung (Q and R). (I, J, S, and T) Quantification of p-ERK immunostaining in E, F, O and P above, showing decreased epithelial p-ERK (I and S) and increased mesenchymal p-ERK (J and T), in Type I PPB and Fgf9-induced mouse lung compared to control tissue. Error bars represent SD. * p<0.05, ** p<0.01, *** p<0.001. (A and B) Five month-old male; (C and D) Three month-old female; (E) Six month-old female; (F) 34 month-old female. Scale bars: A and B, 20 μm; C-P, 50 μm. Sample numbers (n) are indicated on the data bars.