Animal model of sepsis-induced acute lung injury

All animal procedures were conformed to the Guide for the Care and Use of Laboratory Animals. The present study was approved by the Animal Use Committees of Renmin Hospital of Wuhan University. Male wild-type C57BL/6 mice (6–8 weeks old) were obtained from Hubei Province Experimental Animal Center (Wuhan, China). Nrf2‐KO (Stock no.017009) mice were obtained from the Jackson Laboratory. Animals were maintained under specific pathogen-free conditions. All mice were randomized to each group. Unless otherwise specified, the number of mice in each group is 6. The sepsis-induced acute lung injury (ALI) model was established by intraperitoneal LPS instillation at a dose of 10 mg/kg. For the treatment group, mice were pretreated with 4-OI (25 mg/kg) in 40% cyclodextrin for 2 h before stimulation with LPS intraperitoneally for 2 h as described [19]. If improper intraperitoneal injection operation causes the death of the mouse, exclude and supplement the same amount. After stimulation with LPS for 12 h, the left lung of mice was eviscerated. Formalin was instilled in the trachea to expand the alveoli as described [28].