Background: Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily results in warm, swollen, and painful joints. In this study, we investigate the potentially therapeutic role of artesunate (Art) on chondrocyte proliferation, apoptosis and autophagy in rheumatoid arthritis (RA) via the PI3K/AKT/mTOR signaling pathway.
Methods: Rat model of RA was successfully established through subcutaneous injection of emulsion. Positive protein expression rates of PI3K, AKT and mTOR were determined by immunohistochemistry. RA chondrocytes were initially randomized into five different groups. The mRNA expressions of PI3K, AKT, mTOR, Bcl-2, Bcl-xl, LC3-I, LC3-II and Becline-1 were measured by RT-qPCR. Protein expressions of p-PI3K, p-AKT, p-mTOR, Bcl-2, Bcl-xl, Bax, LC3-I, LC3-II and Becline-1 were determined using western blotting. The chondrocytes of rats with RA and normal rats were isolated and cultured in vitro. Chondrocyte proliferation, apoptosis, cell cycle and autophagy were all determined by CCK-8 assay, flow cytometry and transmission electron microscope (TEM).
Results: Artesunate alleviated the inflammation and did not produce any form of hepatotoxicity in rats with RA. In addition, Artesunate decreased expressions of PI3K, AKT, mTOR, p-PI3K, p-AKT, p-mTOR Bcl-2 and Bcl-xl and increased Bax, LC3II/LC3I and Becline-1 protein expression. Artesunate also inhibited chondrocyte proliferation and accelerates cell apoptosis and autophagy via suppression of the PI3K/AKT/mTOR signaling pathway.
Conclusion: Our study demonstrates that Art inhibits chondrocyte proliferation and accelerates apoptosis and autophagy in RA rats through the PI3K/AKT/mTOR signaling pathway.
Keywords: Apoptosis; Artesunate; Autophagy; Chondrocyte; PI3K/AKT/mTOR signaling pathway; Proliferation; Rheumatoid arthritis.
Copyright © 2018. Published by Elsevier Masson SAS.