LPS-induced ALI in mice

Eighteen mice (8–10 weeks) were anesthetized via isoflurane inhalation in a small sealed box and randomly received 8 × 10⁵ IL-35-ADSCs (in 200-μL sterile normal saline (NS)), 8 × 10⁵ GFP-ADSCs (in 200-μL NS) or isovolumetric NS via tail vein injection (6 mice per group) 7 days before LPS administration. Another 6 mice received nothing and were used as the sham group. The LPS-induced ALI model was constructed in mice in accordance with previous reports (Zhang et al. 2018b). All 18 mice received intratracheal (i.t.) instillation of a single dose of 100-μg LPS (Escherichia coli serotype 0111: B4, Sigma-Aldrich) in 50-μL NS. Mice in the sham group were administered 50-μL NS instead of LPS. The four groups were named Sham, saline + LPS (negative control), GFP-ADSCs + LPS (positive control) and IL-35-ADSCs + LPS, respectively. All mice were anesthetized through intraperitoneal injection of chloral hydrate (330 mg/kg), and bronchoalveolar lavage fluid (BALF) and abdominal aortic blood were collected 24 h post LPS exposure. Then, the mice were killed via cervical dislocation, and lung, spleen and peripheral blood samples were harvested. The weight of the mice was recorded at different time points. The wet/dry weight ratio of the right lung was also calculated.