Fig. 10.

Rac1 inhibition impairs human lung branching in vitro. A–D: Dissected 11.1-wk gestational age distal edges of 11 wk gestational age human lung explants at t = 0 (A, C) cultured on air liquid interface in absence (A, B) or presence of NSC23766 (C, D) for 48 h (B, D). E and F: TUNEL staining on sections from paraffin-embedded control explants (E) and NSC23766-treated explants (F) after 48 h in culture. G and H: immunofluorescence for CD31 on control (G) and treated sections (H). I: graph showing fold change in number of branches at 48 h compared with t = 0 h. J: graph illustrating the fold change in AXIN2, FGF10, WIF1, VEGFA, and FGFR2b expression in treated explants normalized to controls. Results in I and J are expressed as means ± SE of explants from 4 independent samples. Scale bars are 50 μm. *P ≤ 0.05.