SPHK1 drives pyroptosis via ROS-dependent activation of the NLRP3 inflammasome in non-infectious uveitis.

INTRODUCTION

Non-infectious uveitis associated with systemic diseases is a sight-threatening inflammatory disorder often associated with dysregulated immune responses and oxidative stress. Although redox imbalance is thought to contribute to its pathogenesis, the precise molecular mechanisms remain poorly defined.

METHODS

We performed transcriptomic analysis of human non-infectious uveitis datasets (GSE17114 and GSE18781) encompassing Behçet's uveitis (BU), sarcoidosis-associated uveitis, and spondyloarthropathy (SpA)-associated uveitis, combined with experimental validation to elucidate oxidative stress-associated mechanisms.

RESULTS

We identified 1,821 differentially expressed genes (DEGs) enriched in immune cell migration, T and B cell signaling, and T cell activation pathways. Among the oxidative stress-associated DEGs, six genes were validated in patients with BU: SPHK1, MMP8, and ARG1 were upregulated, while CCR7, PDGFD, and DDIT4 were downregulated. Knockdown of SPHK1 reduced ROS production, lipid peroxidation, and NLRP3 inflammasome-mediated pyroptosis, decreasing IL-1β and IL-18 secretion; SPHK1 overexpression promoted pyroptosis, reversed by the ROS inhibitor N-acetylcysteine. Molecular docking revealed strong binding affinity between SPHK1 and dexamethasone. All six oxidative stress-related DEGs demonstrated strong diagnostic potential. Immune cell abundance profiling revealed a significant decrease in activated CD4+ T cells, memory B cells, and NK cells in peripheral blood.

DISCUSSION: Collectively, our findings highlight SPHK1 as a key mediator of oxidative stress-induced pyroptosis in non-infectious uveitis and propose the SPHK1-ROS-pyroptosis axis as a potential therapeutic target.