Plasma Metabolic Profiles of Chronic and Recurrent Uveitis Treated by Artesunate in Lewis Rats

Background/Objectives: Identifying effective and safe treatment options for non-infectious uveitis remains challenging due to chronic and relapsing ocular inflammation. Previous studies have shown that artesunate (ART) plays an immunosuppressive role in several classic autoimmune diseases, including uveitis. However, its impact on the plasma metabolic profile of recurrent autoimmune uveitis remains unclear. This study aims to explore the effect of ART on the plasma metabolic features of recurrent experimental autoimmune uveitis (EAU) in a Lewis rat. Methods: Rats were clinically and pathologically evaluated for the development of recurrent EAU induced by inter-photoreceptor retinoid-binding protein (IRBP) R16 peptide-specific T-cells (tEAU). The disruptive effects of ART on tEAU were investigated to evaluate the potential role of rat recurrent EAU. Differentially expressed metabolites were identified in the plasma of rats by untargeted metabolomics analysis after ART treatment. The differential metabolites were applied to subsequent pathway analysis and biomarker analysis by MetaboAnalyst. Results: ART can significantly alleviate the severity of clinical signs and pathological injuries of eyeballs with tEAU. Both non-supervised principal component analysis and orthogonal partial least-squares discriminant analysis showed 84 differential metabolites enriched in 16 metabolic pathways in the tEAU group compared with heathy controls and 51 differential metabolites enriched in 17 metabolic pathways, including arginine and proline metabolism, alanine metabolism, and aminoacyl-tRNA biosynthesis, in the ART-treated group compared with the tEAU group. Particularly, upregulated L-alanine levels in both alanine metabolism and aminoacyl-tRNA biosynthesis were associated with T-cell activation, while elevated spermidine and N-acetyl putrescine levels in arginine and proline metabolism related to T-cell differentiation proved to be valuable biomarkers for ART treatment. Conclusions: Our study demonstrates that ART treatment can alleviate recurrent uveitis by altering the plasma metabolic characteristics associated with T-cell activation and differentiation, which might provide novel insights for potential therapeutic treatments.