Key genes in ferroptosis and oxidative stress pathways associated with ankylosing spondylitis

OBJECTIVE: This study investigated the expression profiles and clinical significance of oxidative stress-related genes (ORGs) and ferroptosis-related genes (FRGs) in peripheral blood mononuclear cells (PBMCs) of patients with ankylosing spondylitis (AS). METHODS: The GSE73754 dataset was downloaded from GEO, and differentially expressed genes (DEGs) were identified and subsequently intersected with FRGs curated from the Driver, Suppressor, Marker, and Unclassified databases and ORGs retrieved from the MSigDB database. Functional enrichment (GO/KEGG) was performed, protein-protein interaction (PPI) networks were constructed, and hub genes were identified using cytoHubba; the overlap of hub sets yielded seven key genes (G6PD, CYBB, TXNRD1, AKR1C3, MAP3K5, PARK7, and NFE2L2). Immune infiltration was estimated by ssGSEA, and key genes were validated by RT-qPCR in PBMCs from 113 AS patients (53 active, 60 stable), 48 rheumatoid arthritis patients, 24 osteoarthritis patients, and 50 healthy controls. RESULTS: We identified 44 differentially expressed FRGs and 40 differentially expressed ORGs enriched mainly in oxidative stress, lipid metabolism, and ferroptosis-related pathways; a four-gene nomogram was developed to predict AS risk. RT-qPCR confirmed the upregulation of G6PD and CYBB expression and the downregulation of the expression of TXNRD1, AKR1C3, MAP3K5, PARK7, and NFE2L2 in AS. Notably, G6PD levels were significantly higher in HLA-B27-positive patients. RT-qPCR analysis showed that G6PD had good diagnostic performance (AUC = 0.826), while CYBB expression was positively correlated with multiple inflammatory markers. CONCLUSION: Differentially expressed FRG and ORG play important roles in the pathogenesis of AS, with G6PD and CYBB potentially serving as potential AS-associated biomarkers.