Oral Rosiglitazone Supplementation Mitigates Pulmonary Cellular Stress Response During Lipopolysaccharide‐Evoked Acute Lung Injury in Mice

Abstract

Cellular stress is implicated in the progression of lipopolysaccharide (LPS)‐evoked acute lung injury (ALI). The goal of this study was to evaluate the effect of oral supplementation with rosiglitazone (RSG), which is an agonist of peroxisome proliferator‐activated receptor (PPAR)‐γ, on pulmonary inflammatory response, oxidative stress, and endoplasmic reticulum (ER) stress during LPS‐evoked ALI in mice. The mice were randomly divided into four groups and orally supplemented with or without RSG (10 mg/kg) once daily for 5 consecutive days before LPS (1 mg/kg) intraperitoneal injection. The mice were sacrificed at 12 h after LPS injection. As expected, LPS‐evoked ALI and death were attenuated in mice that were pretreated with RSG. LPS‐evoked increase in chemokines (KC, MIP‐2, and MCP‐1) and proinflammatory cytokines (TNF‐α and IL‐1β) was inhibited in the mouse lungs by RSG. RSG pretreatment significantly mitigated LPS‐evoked nuclear translocation of NF‐κB p65 and p50, which regulate inflammatory gene transcription in the lungs. Additionally, LPS‐evoked glutathione depletion and lipid peroxidation were alleviated by RSG. The abnormal expression of NADPH oxidases and antioxidant enzymes was restored in the lung tissues by RSG. Further experiments revealed that LPS‐evoked upregulation of GRP78, p‐IRE1α, and p‐EIF2α was blocked by RSG pretreatment. Mechanistically, RSG pretreatment enhanced PPARγ activity in the mouse lungs and bronchial epithelial cells. RSG promoted the interaction between NF‐κB p65 and PPARγ in the mouse lungs. Overall, RSG pretreatment protects against LPS‐evoked ALI partially through enhancing PPARγ activity and inhibiting the cellular stress response in the mouse lungs.