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

BACKGROUND

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.

METHODS

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 (Fe2+), 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.

RESULTS

(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.

CONCLUSION

In sepsis-induced lung injury, the ferroptosis-related SLC7A11/GSH/GPX4 signaling pathway is downregulated. Ferrostatin-1 activates this pathway and protects the lungs.