RÉSUMÉ
To investigate the differentiation of bone mesenchymal stem cells(BMSCs) into chon-drocytes by miRNA-206 and its mechanism in osteoarthritis(OA). Methods From January, 2017 to July, 2018, rat BMSCs were isolated, and their CD90 and CD45 were detected by flow cytometry. Transfection of miRNA-206 or miRNA-206 inhibitors into BMSCs using lentiviral vectors, dexamethasone induction for 14 d, then use alician blue staining and type II collagen immunostaining to detect chondrogenic differentiation. MTT assay was used to detect the proliferation of mesenchymal stem cells. Western blot analysis was used to detect the Aggrecan, Col II, Sox9 and Runx2 markers in chondroblast cells. The expression level of the marker gene of Sox9 mRNA in chondroblasts were detected by RT-PCR.OA rat models were treated with lentiviral vectors transfected with miRNA-206 or miRNA-206 inhibitors, and Aggrecan, Col II, Sox9, Runx2 which were the markers of chondrogenesis were detected by Western blot. Results The purity of isolated BMSCs was (80.7±3.9)%. BMSCs transfected with miRNA-206 could promote cell proliferation and increase chondrogenic differentiation. Western blot results showed that the expression of Aggre-can, Col II and Sox9 was increased in the miRNA-206 transfection group, and the expression of Runx2 was down-regulate. Meanwhile, RT-PCR results showed that miRNA-206 can up-regulate the expression of the chondroblast marker gene Sox9 mRNA in BMSCs.Compared with the OA group, miRNA-206 could increase the expression of Aggre-can, Col II and Sox9 signaling proteins in cartilage tissue (P＜0.05), and down-regulate the expression level of Runx2 (P＜0.05). Conclusion The miRNA-206 can positively regulate the differentiation of BMSCs into chondrocytes, increase the ability of cell proliferation, up-regulate the expression of Aggrecan, Col II and Sox9, and down-regulate Runx2.The miRNA-206 increase chondrogenic capacity in rat models of osteoarthritis.