Rho deficiency alters in vivo neutrophil emigration and augments LPS-induced ALI. (A) Influx of neutrophils in RhoA KO, RhoB KO², or RhoA/B dKO mice 5 hours after ip thioglycollate injection (n = 5). (B-C) Peritoneal neutrophil infiltrate in RhoB KO² or RhoA/B dKO mice 5 hours after ip injection with (B) zymosan (n = 3) and (C) E coli (n = 8). (A) Data are presented as percentage change in peritoneal neutrophils (% migration) of RhoA KO, RhoB KO¹, and RhoA/B dKO mice compared with their controls WT¹, WT², and RhoB KO², respectively. (D-G) Quantification of neutrophils in lung BAL fluid 5 hours after in challenge with (D) CXCL1 (n = 4), (E) fMLF (n = 4), or (F) E coli (n = 3), or 24 hours after (G) LPS (n = 7). (H-K) Protein (H) (n = 4), chemokine and cytokine (I) (n = 4) content, MPO activity (J) (n = 4), and NET formation (K) (n = 3) within BAL collected from RhoB KO² or RhoA/B dKO mice 24 hours after in challenge with LPS. AU, arbitrary units. (L) Hematoxylin and eosin staining of lung tissue 24 hours after LPS instillation; the scale bar represents 200 μm (images 1-6) and 20 μm (images 7-9). Images are representative of 20 fields per section, 3 sections per lung, 4 lungs per genotype per experiment. (M) Modified Carstairs staining performed on lung tissue as in (L); the scale bar represents 1 μm (upper 2 panels) and 200 μm (lower panel). Images are representative of 30 fields per section, 2 sections per lung, 3 lungs per genotype per experiment. (A-K) Data are pooled from 3 experiments. Means ± SEM (n indicated): (A-J) *P < .05, **P < .01, ***P < .005 by unpaired 2-tailed Student t test.