Figure 3

Hmga2 is required for proper differentiation of the distal epithelium. (A) Sections of embryonic lung (E18.5) of WT and Hmga2-KO mice were analyzed as in Figure 2C using clCASP3- and KRT- (left) or ACTA2- (right) specific antibodies. Nuclear staining with DAPI (blue). Scale bars, 40 μm. (B) Quantification of clCASP3 positive epithelial (KRT) and mesenchymal (ACTA2) cells showed increased apoptosis in epithelial cells of Hmga2-KO mice embryonic lung. Sections of embryonic lung (E18.5) of WT and Hmga2-KO mice were treated as in A and used for quantification. Error bars show the SEM (n = 3). (C) Sections of embryonic lung (E18.5) of WT and Hmga2-KO mice were analyzed as in Figure 2C using (left) SFTPC- and PCNA-specific antibodies or (right) SOX9- and PCNA-specific antibodies. Nuclear staining with DAPI (blue). Scale bars, 40 μm. (D) Quantification of proliferating SFTPC- and SOX9-positive cells showed reduced differentiation and increased proliferation of progenitor cells in the distal epithelium of Hmga2-KO mice embryonic lung. Sections of embryonic lung (E18.5) of WT and Hmga2-KO mice were treated as in C and used for quantification. Error bars show the SEM (n = 3).