SLC7A11 suppresses pyroptosis to alleviate rheumatoid arthritis development by modulating the IL-17 pathway

Background: Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology. This study aims to explore the potential mechanisms by which solute carrier family 7 member 11 (SLC7A11) influences RA development.

Methods: Collagen-induced arthritis (CIA) mice were constructed to observe disease onset and pathological scores. Pathological changes were examined using Hematoxylin-eosin and Safranin O-Fast Green staining. Levels of lactate dehydrogenase (LDH), inflammatory cytokines (tumor necrosis factor [TNF]-α, interleukin [IL]-18 and IL-1β), and oxidative stress (reactive oxygen species, malondialdehyde, and glutathione) were measured using ELISA. Western blotting was performed to detect the expression of pyroptosis- and pathway-related proteins. Fibroblast-like synoviocytes of RA (RA-FLS) were treated with TNF-α. Cell migration, invasion, and Caspase-1 levels were assessed through scratch assays, Transwell assays, and flow cytometry, respectively. The correlation between SLC7A11 and immune cell infiltration in RA was analyzed using bioinformatics. Additionally, downstream pathways of SLC7A11 in RA were screened, and the impacts of SLC7A11 on these pathways were validated in vitro.

Results: CIA mice were successfully established, revealing significant downregulation of SLC7A11 in RA. Staining results indicated that overexpression of SLC7A11 significantly mitigated joint damage in CIA mice. In vitro experiments demonstrated that overexpression of SLC7A11 inhibited migration, invasion, and Caspase-1 expression levels in TNF-α-induced RA-FLSs. Furthermore, SLC7A11 suppressed inflammation, LDH release, and oxidative stress, while inhibiting pyroptosis. SLC7A11 expression was significantly different in multiple immune cells. The IL-17 pathway was identified as a downstream pathway of SLC7A11, and SLC7A11 inhibited the expression of IL-17 pathway proteins. Additionally, rhIL-17A, an activator of the IL-17 pathway, attenuated the inhibitory effects of SLC7A11 on inflammation, oxidative stress, and pyroptosis.

Conclusion: SLC7A11 suppresses pyroptosis to alleviate RA development by inhibiting the IL-17 pathway.