Ferroptosis, orchestrated by GPX4 downregulation, serves as a critical mediator of neutrophil extracellular trap-driven pathology in hypoxic pulmonary edema.

Abstract

This study explores the contribution of ferroptosis, a tightly regulated form of cell death, to the development of high-altitude pulmonary edema (HAPE) under hypoxic conditions. We focused on the central ferroptosis regulator glutathione peroxidase 4 (GPX4) and its interaction with neutrophil extracellular trap (NET) formation. Utilizing a murine model of high-altitude hypoxia and in vitro hypoxia/reoxygenation models, we employed a multi-omics approach to map the molecular landscape of HAPE. Transcriptomic and metabolomic analyses of lung tissues confirmed a significant downregulation of GPX4 and a marked activation of ferroptosis-related pathways. Single-cell RNA sequencing identified pulmonary endothelial cells as a key site for this dysregulation, showing decreased GPX4 alongside upregulation of pro-ferroptotic factors. Functional validation demonstrated that GPX4 deficiency in human pulmonary microvascular endothelial cells exacerbated reactive oxygen species accumulation, ferroptosis, and subsequent NET formation. Conversely, GPX4 overexpression effectively mitigated these cytotoxic effects. Furthermore, we elucidated that GPX4 modulates NET formation through key signaling pathways, including Nrf2 nuclear translocation, ERK1/2 and NF-κB phosphorylation, and the HMGB1-TLR4/MyD88 axis. In vivo, therapeutic augmentation of GPX4 levels attenuated pulmonary edema, improved lung function, and suppressed markers of both ferroptosis and NETosis. Our findings establish a novel pathogenic cascade in HAPE where hypoxia-induced GPX4 suppression promotes ferroptotic cell death, which in turn drives NET-associated inflammation, identifying GPX4 as a critical therapeutic target for preventing this condition.