Effect of AQP9 deletion on LPS-induced ALI and pulmonary inflammation. (A, B, H) AQP9 KO and WT mice were intratracheally instilled with LPS (5 mg/kg), then sacrificed at days 1, 3, and 6 after surgery for functional analysis. (A) Representative images and (B) lung injury score analysis of H&E staining of lung tissues (n = 5). Scale bars, 50 μm. (C-G) Male WT and AQP9 KO mice were sacrificed at day 3 after LPS (5 mg/kg) administration for functional analysis. (C) Pulmonary Wet/Dry weight ratio (n = 3). (D) Quantity of inflammatory cells in BALF (n = 5). (E) Total protein content in BALF (n = 3). (F) Concentration of IL-6 and IL-10 in BALF (n = 3). (G) mRNA levels of IL-1β and TNF-α in lung tissues (n = 3). (H) Representative CD68+ staining and quantitative analysis in cross-sections of lung tissues (n = 3). Scale bars, 20 μm. Data are expressed as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001, two-way ANOVA for comparisons with multiple variables.