FIGURE 8. Mechanical ventilation with a high tidal volume activates NLRP3 inflammasome in mouse lungs.

Wild type and gp91^phox−/− mice were ventilated with a normal (L) or high (H) tidal volume for the indicated times. At the end of experiments, lung tissue and BAL fluid were recovered. A. Effects of mechanical ventilation and SS-31 on NLRP3 inflammasome activation and subsequent release of IL-1β and IL-18. Top: The assembly of NLRP3 inflammasome was detected using immunoprecipitation with anti-ASC Ab followed by immunoblotting for NLRP3, ASC, and caspase-1 cleavage product p10 fragments (Casp-1). Bottom: The levels of mature IL-1β, mature IL-18, Pro-IL-1β, Pro-IL-18, Pro-Casp-1 and Casp-1 in lung homogenates were determined by Western blot analysis. B. The levels of IL-1β in BAL fluid were measured by ELISA. The graph shows the mean and SEM from six mice. C. Effects of depletion of AMs with liposome on mechanical ventilation-induced release of IL-1β and IL-18, and caspase-1 activation. The levels of mature IL-1β, mature IL-18, Pro-IL-1β, Pro-IL-18, Pro-Casp-1 and Casp-1 in lung homogenates were determined by Western blot analysis. D. The levels of IL-1β in BAL fluid were measured by ELISA (n=6). *p < 0.05 vs. the control group (L). † p <0.05 vs. WT+H group (B, 2h alone) or PBS+H group (D).