Artesunate ameliorates experimental autoimmune uveitis by inhibiting the LCN2-STAT3 axis and suppressing microglial activation.

OBJECTIVE: To evaluate the efficacy and underlying molecular mechanisms of artesunate (ART) in experimental autoimmune uveitis (EAU). METHODS: An EAU mouse model was established and treated with ART via oral gavage. Disease severity was assessed by clinical scoring and retinal histology. SPR analysis examined ART binding to LCN2 and STAT3. Immunofluorescence co-staining was conducted to evaluate the expression and co-localization of LCN2 with microglia in retinal tissues. Western blot analysis was performed to measure protein levels of STAT3, LCN2, SLC7A11, FTH1, GPX4, IL-6, IL-1β, IL17A and TNF-α. In vitro, BV2 microglial cells were used, and LCN2 was knocked down with siRNA. Inflammatory cytokine concentrations in retina and BV2 cell culture supernatants were assessed through ELISA. RESULTS: ART treatment significantly improved clinical and histopathological scores in EAU mice and exhibited moderate binding affinity for LCN2 and STAT3. It suppressed microglial activation and downregulated the expression of LCN2 and STAT3, along with the release of IL-6, IL-1β, IL17A and TNF-α. In BV2 microglial cells, ART decreased LCN2 expression and attenuated proinflammatory cytokine secretion. CONCLUSIONS: Artesunate attenuates EAU by inhibiting the LCN2-STAT3 axis and suppressing the activation of microglial and Th17 cells.