The role of cellular senescence in the pathogenesis of Rheumatoid Arthritis: Focus on IL-6 as a target gene

Abstract

Background: Rheumatoid arthritis is a chronic autoimmune disease. However, the specific role of senescence in rheumatoid arthritis (RA) is unknown. This study aimed to identify potential aging-related genes that have diagnostic and therapeutic value for RA.

Methods: The GSE89408 dataset was downloaded from the Gene Expression Omnibus (GEO). Aging-related genes were downloaded from the HAGR database. Differentially expressed genes (DEGs) were subsequently identified with the "edgeR" tool. Next, hub genes were identified with a PPI network and CytoHubba analysis. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic value of these hub genes. Immune infiltration analysis was performed with the CIBERSORT algorithm. Additionally, molecular docking was performed with CB-Dock2. Finally, correlation experiments were performed to validate the bioinformatics and molecular docking results.

Results: A total of 22 ADEGs were identified. Combined PPI network and CytoHubba analyses identified a total of 7 hub genes, including IL-6, IL7R, IL2RG, CDK1, PTGS2, and LEP, which are associated mainly with inflammation and immune responses. ROC analysis revealed that the hub genes were highly predictive of RA. Analysis of immune infiltration revealed that the 6 hub genes were positively associated with M1 macrophages. Validation experiments revealed that the inhibition of IL-6 significantly decreased the degree of synovial fibroblast (FLS) senescence. Furthermore, molecular docking and validation experiments revealed that IL-6 is a potential target for drug therapy.

Conclusion: This study demonstrated that RA-FLS senescence may promote the development of RA via inflammatory and immune mechanisms. Seven hub genes were identified, of which IL-6 is a reliable biomarker for the diagnosis and treatment of RA.

Keywords: Cellular senescence; IL-6; Immune infiltration; Rheumatoid arthritis; Synovial fibroblasts.