Ferrostatin-1 attenuates inflammatory response to hypoxic lung injury at plateau by inhibiting ferroptosis in lung epithelial cells

To investigate the protective effects of ferroptosis inhibitor ferrostatin-1 (Fer-1) on high-altitude hypoxic lung injury and explore novel preventive strategies for high-altitude hypoxia-induced lung injury.

①Eighteen SPF male Wistar rats (5~6 weeks old, 210~230 g) were randomly divided into 3 groups (n=6): normoxic control, hypoxic lung injury, and Fer-1 pretreatment groups. A hypobaric chamber was used to establish a rat model of high-altitude hypoxic lung injury. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed to compare pulmonary protein profiles between normoxic and hypoxic groups, followed by bioinformatics analysis of pathways enriched with differentially expressed proteins (DEPs). Histopathological changes and lung injury scores were assessed with HE staining. ELISA was used to quantify the inflammatory cytokines, flow cytometry and immunofluorescence assay were employed to measure the production of reactive oxygen species (ROS), and spectrophotometry was utilized to determine the contents of Fe²⁺, glutathione (GSH), malondialdehyde (MDA), and superoxide dismutase (SOD) to evaluate oxidative stress and detect ferroptosis-related markers. ② Human bronchial epithelial cells (bronchial epithelium transformed with Ad12-SV40, BEAS-2B) and macrophages induced by tumor human peripheral blood monocytes-1 (THP-1) cells were placed in a low oxygen conditions for 48 h to establish a cellular model of hypoxic lung injury, on which Fer-1 was administered as a preventive group. Ferroptosis markers in BEAS-2B cells and inflammatory cytokine secretion in macrophages were analyzed.

① Proteomics identified 2962 proteins, with 357 DEPs (199 up-regulated, 158 down-regulated). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed ferroptosis as the most enriched pathway. Hypoxic lung injury resulted in elevated ROS, MDA, Fe²⁺, and inflammatory cytokines (P<0.05), reduced SOD, GSH, solute carrier family 7 member 11 (SLC7A11), glutathione peroxidase 4 (GPX4), and ferritin heavy chain 1 (FTH1), and increased acyl-coa synthetase long chain family member 4 (ACSL4) (P<0.05). Fer-1 pretreatment significantly mitigated oxidative stress (ROS, MDA, SOD, GSH; P<0.05), up-regulated SLC7A11 and FTH1, down-regulated ACSL4 (P<0.05), and reduced inflammation (P<0.05). ② In cellular models, Fer-1 increased SLC7A11, GPX4, FTH1, GSH, and SOD (P<0.05), declined ROS (P<0.05), and suppressed macrophage inflammatory cytokines (P<0.05).

Fer-1 alleviates high-altitude hypoxic lung injury by inhibiting ferroptosis in pulmonary epithelial cells and attenuating macrophage-driven inflammation, providing experimental evidence for novel therapeutic strategies.