NLRP3 and acute respiratory distress syndrome: Administration of metformin and NLRP3 inhibitor MCC950 remarkably decreased inflammasome activation and the level of pyroptosis-related indicators in LPS-treated pulmonary ECs and LPS-induced ALI mice, indicating that the potential therapeutic role of metformin in targeting the endothelial pyroptosis in ALI may be attributed to the activation of NLRP3 inflammasome.