Purpose: Noninfectious uveitis is a sight-threatening autoimmune eye disease lacking effective targeted therapies. Dipyridamole (DIP),a phosphodiesterase (PDE) inhibitor,has demonstrated anti-inflammatory properties in inflammatory diseases. However,its application in uveitis remains unexplored. Methods: We used single-cell RNA sequencing (scRNA-seq) data from experimental autoimmune uveitis (EAU) mice and uveitis patients to assess the potential association of PDE gene expression with disease development. Subsequently,EAU mice received oral DIP (300 mg/kg/day),starting at different time points (preventative,early-therapeutic,or late-therapeutic),and treatment efficacy was assessed. To explore immune components and signaling changes,we profiled cervical draining lymph nodes (CDLNs) from control,EAU,and DIP-treated mice by scRNA-seq and validated key findings with additional experiments. Mechanistically,pharmacologic interventions (an adenylyl cyclase inhibitor and the STAT3 agonist) were used in vitro. Results: Expression of several PDE genes correlated with uveitis severity in both human and mouse. Preventative DIP treatment most effectively reduced fundus inflammation in EAU and modulated the Teff/Treg ratio in the CDLNs and spleens. In vitro,DIP suppressed CD4+ T cell proliferation,and inhibited pathogenic Teff. scRNA-seq analysis revealed that DIP partially reversed EAU-induced transcriptional alterations,with notable changes in immune cell composition and pathway activity. Mechanistically,DIP downregulated STAT3 activity and PIM1 expression in Th17 cells via cAMP,suggesting the involvement of the cAMP-STAT3-PIM1 axis in modulating immune homeostasis. Conclusions: DIP ameliorated intraocular inflammation,modulated Th17/Treg balance,and reduced Th17 pathogenicity in EAU,potentially via cAMP-STAT3-PIM1 signaling. These findings highlight DIP as a promising therapeutic candidate for autoimmune uveitis.
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