The Role of Torkinib in Inhibiting the Proliferation and Migration of Rheumatoid Arthritis Fibroblast-Like Synoviocytes

Abstract

This study aims to investigate the potential of an inhibitor of the mammalian target of rapamycin (Torkinib) as a therapeutic drug targeting fibroblast-like synoviocytes (FLS) presenting it as a promising alternative for the treatment of rheumatoid arthritis (RA). FLS were isolated and cultured from RA patients for cellular experiments. The collagen-induced arthritis model in mice was constructed using type II collagen emulsion for animal experiments. Cell viability was assessed using cell counting kit-8 and 5-ethynyl-2′-deoxyuridine staining assays, and flow cytometry was utilized to detect cell apoptosis. The scratch assay assessed cell migratory capacity, while the transwell assay evaluated cell invasive potential. Electron microscopy and monodansylcadaverine staining were employed for autophagy detection, and western blot analysis assisted by nanomagnetic beads examined the expression of relevant proteins. In animal experiments, arthritis development was evaluated using clinical scores and hematoxylin and eosin staining. As a result, Torkinib effectively inhibits the proliferation of RA-FLS with a 50% inhibitory concentration of 8.53 nM. Furthermore, Torkinib induces apoptosis in FLS and activates cellular autophagy while suppressing cell migration and invasion by inhibiting the mammalian target of the rapamycin (mTOR) signaling pathway. Additionally, we observed an antagonistic effect between Torkinib and 3-methyladenine. In summary, Torkinib demonstrates its potential in alleviating RA symptoms in CIA mice and enhancing disease progression.