Sufentanil attenuates LPS-induced acute lung injury by suppressing ferroptosis and maintaining GPX4 protein abundance.

INTRODUCTION: Acute lung injury (ALI) is a severe inflammatory syndrome characterized by disruption of the alveolar-capillary barrier, pulmonary edema, and impaired gas exchange. Ferroptosis has emerged as an important contributor to ALI pathogenesis, but the mechanisms associated with reduced glutathione peroxidase 4 (GPX4) protein abundance during lung injury remain incompletely understood. METHODS: This study investigated the protective effects of sufentanil pretreatment against lipopolysaccharide (LPS)-induced ALI and examined whether these effects were associated with ferroptosis suppression and maintenance of GPX4 protein abundance. A mouse model of LPS-induced ALI and LPS-stimulated A549 cells were used to evaluate the effects of sufentanil in vivo and in vitro. The contribution of GPX4 was assessed using siRNA-mediated knockdown and pharmacological modulation of ferroptosis. Potential CMArelated lysosomal involvement was explored using pathway inhibition, coimmunoprecipitation, colocalization analysis, and LAMP2A knockdown. RESULTS: Sufentanil pretreatment alleviated LPS-induced lung injury, reduced inflammatory responses, and attenuated ferroptosis-associated alterations in vivo. In A549 cells, sufentanil reduced mitochondrial and lipid reactive oxygen species, intracellular Fe2+ accumulation, mitochondrial damage, and ACSL4 upregulation, while restoring GPX4 and SLC7A11 protein abundance. GPX4 knockdown markedly attenuated the protective effects of sufentanil. The maintenance of GPX4 protein abundance observed after sufentanil pretreatment was accompanied by reduced GPX4-LAMP2A colocalization and reduced association between GPX4 and HSC70. Furthermore, erastin partially reversed the protective effects of sufentanil in vivo. DISCUSSIONS: These findings support a preconditioning effect of sufentanil against LPS-induced ALI, associated with ferroptosis suppression, maintenance of GPX4 protein abundance, and possible CMA-related lysosomal involvement.