Figure 6.

Deletion of Foxf1 from endothelial cells (ECs) causes alveolar simplification. (A–D) Hematoxylin and eosin staining of lung paraffin sections shows alveolar simplification in tamoxifen-treated PDGFb-Cre/Foxf1^−/− mice (A and B) and Kit^w-sh mice (C and D). Mice were exposed to hyperoxia (HO) or room air (RA) from Postnatal Day 1 (P1) and harvested at P7. Percentages of airspace were calculated using 10 random lung fields (n = 5 mice per group). Scale bars, 50 μm. (E and F) FACS analysis shows the lack of c-KIT staining in ECs of Kit^w-sh lungs (n = 3). *P < 0.05 and **P < 0.01. WT = wild type.