Abstract
Background: Tendinopathy is currently the common clinical condition related to sports injury. The main pathological change in tendinopathy is ectopic ossification in tendon tissue, but the mechanisms have remained elusive. Studies have found that interleukin-6 (IL-6) is a major inflammatory mediator in chronic tendinopathy, and osteogenic differentiation of tendon stem cells (TSCs) is believed to be closely related to ectopic ossification of tendons. Methods: Rat tendon-derived stem cell (rTDSC) culture model, Lentivirus transfection, Alkaline phosphatase staining, Real-time PCR and Western blotting were performed in this study.Results: We showed that after IL-6 induction, the mRNA expression of Runx2, Alpl, Dlx5, and Wnt5a and the protein expression of phosphorylated STAT3, Runx2, and Wnt5a were increased in rTDSCs. Wnt5a shRNA and cDNA induced silencing and overexpression of Wnt5a inhibited and promoted osteogenic differentiation of rTDSCs, respectively. The addition of a STAT3 inhibitor inhibited osteogenic differentiation and Wnt5a mRNA and protein expression in rTDSCs, and this inhibition was reversed by cDNA induced Wnt5a overexpression. Conclusion: We concluded that IL-6 promotes osteogenic differentiation of rTDSCs through the STAT3/Wnt5a signalling pathway.