TLR3 as an emerging molecule facilitating pyroptosis in the context of rheumatoid arthritis: A study combined bioinformatics and experimental validation.

Background: Rheumatoid arthritis (RA) is an inflammatory disease of the joints mediated by immune cells. As an immune-related mode of cell death, pyroptosis has yet to be fully understood in RA. This research identified novel pyroptosis-related markers in RA and confirmed its functional significance in RA.

Methods: Initially, crucial pyroptosis-related genes of RA were identified through GEO database, and biological pathways were determined through enrichment analysis. Then, PPI network, WGCNA and CIBERSORT analysis was utilized to screen hub genes and evaluate immune cell infiltration levels. Finally, validation experiments determined hub genes expression and regulatory roles in RA pathogenesis, and screened potential therapeutic drugs.

Results: A total of 46 DEPRGs in RA were identified, which involved in NOD-like receptor and Toll-like receptor signaling pathway. Further screening revealed 3 crucial hub genes: CCL5, LY96, and TLR3 had significantly increased expression in RA synovial tissue and FLS, which might become diagnostic markers of RA. Analysis of immune infiltration revealed that hub genes exhibited associations with plasma cells, T lymphocytes, and macrophages. Further study on the crucial hub gene TLR3 revealed that knocking down TLR3 significantly inhibited the RA FLS hyperproliferation and pyroptosis, and dexamethasone and doxorubicin, as potential drugs, could treat RA by inhibiting TLR3.

Conclusions: Our study indicates that high expression of TLR3 promotes FLS pyroptosis and RA progression, suggesting its potential as both a biomarker and a therapeutic target for RA.