Ferrostatin-1 attenuates sepsis-induced lung injury by inhibiting ferroptosis via activation of the SLC7A11/GSH/GPX4 signaling pathway

Ferroptosis is increasingly recognized as a pathological mechanism implicated in sepsis-induced lung injury. The study investigated the mechanism by which the ferroptosis inhibitor Ferrostatin-1 (Fer-1) attenuates lung injury through modulation of the solute carrier family 7 member 11 (SLC7A11)/glutathione (GSH)/glutathione peroxidase 4 (GPX4) signaling pathway. In vivo and in vitro models were established by performing cecal ligation and puncture (CLP) in rats and stimulating MLE-12 cells with lipopolysaccharide (LPS), respectively. These models were subsequently intervened with Fer-1 and Erastin. The 7-day survival rate of septic rats was monitored, and serum levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured. Histopathological examination of lung tissue was performed using hematoxylin and eosin (H&E) staining, while the lung wet/dry weight (W/D) ratio and protein concentration in bronchoalveolar lavage fluid (BALF) were assessed to evaluate pulmonary edema. Levels of ferrous ions (Fe 2+ ), prostaglandin-endoperoxide synthase 2 (PTGS2), and malondialdehyde (MDA)—were quantified. Lipid peroxidation was evaluated using the BODIPY™ 581/591 C11 fluorescent probe, and mitochondrial ultrastructural changes were examined via transmission electron microscopy. Additionally, the expression levels and activities of GPX4, SLC7A11 and GSH were determined. (1) Fer-1 administration effectively mitigates systemic inflammation in septic rats by reducing serum levels of IL-6 and TNF-α, while significantly improving the 7-day survival rate. Furthermore, Fer-1 attenuates pathological lung injury, decreases the lung W/D ratio, and reduces protein concentration in BALF. In vitro, Fer-1 treatment enhanced the viability of LPS-stimulated MLE-12 cells. (2) Ferroptosis was activated in septic rats and LPS-stimulated MLE-12 cells. Fer-1 treatment reduced ferroptosis markers such as PTGS2, malondialdehyde, and lipid peroxidation, alleviated mitochondrial damage—marked by decreased volume, lower membrane density, fewer cristae, and outer membrane rupture—and restored mitochondrial function. Additionally, Fer-1 enhanced expression of key components in the SLC7A11/GSH/GPX4 signaling pathway. In sepsis-induced lung injury, the ferroptosis-related SLC7A11/GSH/GPX4 signaling pathway is downregulated. Ferrostatin-1 activates this pathway and protects the lungs. • Fer-1 improved survival and attenuated lung injury and systemic inflammation in septic rats. • Fer-1 enhanced the expression of key components in the SLC7A11/GSH/GPX4 signaling pathway and suppressed ferroptosis in sepsis by reducing intracellular ferrous ion and lipid peroxidation levels. • Fer-1 protected LPS-stimulated MLE-12 cells by improving cell viability and preserving mitochondrial function. • Targeting ferroptosis with Fer-1 represents a promising therapeutic strategy for mitigating sepsis-induced lung injury.