Lemon-Derived Exosomes Mitigate Sepsis-associated acute kidney injury in Mice by Inhibiting Ferroptosis in Proximal Tubule Epithelial Cells

Abstract Background Sepsis-associated acute kidney injury (SAKI) is a common and life-threatening complication of sepsis. The cellular heterogeneity of SAKI and the molecular mechanisms driving injury to proximal tubular epithelial cells (PTCs) remain incompletely understood, and targeted therapies are currently lacking. Methods Here, using single-cell RNA sequencing (scRNA-seq), network pharmacology, molecular docking, and experimental validation, we investigated the cellular heterogeneity and injury mechanisms of SAKI and explored targets of lemon-derived extracellular vesicles (EVs) for SAKI treatment. Results Single-cell RNA sequencing analysis of 6,353 renal cells revealed pronounced cellular heterogeneity in SAKI, mainly characterized by a marked reduction in proximal tubular epithelial cells (PTCs) and disruption of intercellular communication networks. By cross-analyzing 2,472 lemon-related potential targets with 3,406 PTC injury–related pathogenic targets, 365 common targets were identified; functional enrichment analysis indicated that lipid peroxidation and ferroptosis pathways may be involved. Molecular docking showed strong binding between lemon bioactive compounds and ferroptosis regulators (binding energies up to − 10.7 kcal·mol − 1). Based on these results, we isolated lemon-derived EVs and confirmed their physicochemical properties and biocompatibility. Administration of the EVs inhibited PTCs ferroptosis with ACSL4 acting as an effector, reduced renal edema, proteinuria, and tissue damage in septic mice, ameliorated CLP-induced hypothermia, and improved short-term survival. Conclusion This work delineates ACSL4-mediated ferroptosis in tubular cells as a key pathological driver of SAKI. By leveraging integrative omics and experimental validation, we further demonstrate that lemon extracellular vesicles serve as a natural, multi-targeted nanoplatform capable of suppressing this pathway, attenuating renal injury and enhancing survival in sepsis. These findings support EV-mediated inhibition of ferroptosis as a therapeutic rationale for SAKI and warrant further preclinical development.