Severe ARDS following intratracheal instillation of LPS in H89-treated or Tgm2^−/− mice. (A) Inflammatory cytokines in BALF of mice pretreated with H89 24 hours before IT LPS instillation. (B) Histological evidence of lung inflammation by hematoxylin and eosin staining of lung tissues from ARDS mice with or without H89 pretreatment. (C) Inflammatory cytokines in BALF of WT or Tgm2^−/− mice 24 hours after IT LPS instillation. (D) Hematoxylin and eosin staining of lung sections from WT or Tgm2^−/− mice 24 hours after LPS IT instillation. Data are shown as mean ± standard error of the mean. Significant differences are denoted as *P < .05; **P < .01; ***P < .001; ****P < .0001. Scale bars represent 100 μm (B,D).