中文摘要：

背景：相关研究认为,骨髓间充质干细胞具有良好的增殖及分化能力,Sox9转录因子在软骨形成及维持软骨细胞表型方面起关键作用。目的：明确Sox9转染骨髓间充质干细胞对骨关节炎病变软骨的修复作用。方法：体外以慢病毒为载体介导Sox9基因转染骨髓间充质干细胞。通过切断前交叉韧带建立小鼠膝关节骨关节炎模型,将小鼠随机分为生理盐水组、单纯骨髓间充质干细胞组及Sox9转染骨髓间充质干细胞组,分别将0.1 mL生理盐水、0.1 mL无转染骨髓间充质细胞生理盐水溶液、0.1 mL的Sox9转染骨髓间充质细胞生理盐水溶液注射入小鼠膝关节腔内。注射后4,8,12周后通过甲苯胺蓝及免疫组织化学染色检测病变关节软骨的修复情况。结果与结论：（1）关节软骨病变：甲苯胺蓝染色显示,生理盐水组关节软骨病变较间充质干细胞组严重,且时间越长差别越明显,单纯骨髓间充质干细胞组软骨损伤有改善,但改善情况差于Sox9转染骨髓间充质干细胞组;（2）免疫组织化学染色显示,Sox9转染骨髓间充质干细胞组Ⅱ型胶原表达均强于其他2组,各组随时间阳性轻度减弱;（3）结果提示,Sox9转染小鼠骨髓间充质干细胞对小鼠膝关节炎病变软骨修复有促进作用。

英文摘要：

BACKGROUND： Bone marrow mesenchymal stem cells are considered to have good proliferation anddifferentiation potentials. Sox9 is a transcription factor that is essential for chondrogenesis and has been termed as a ＂master regulator＂ of the chondrocyte phenotype. OBJECTIVE： To study the therapeutic effects of Sox9-transfected bone marrow mesenchymal stem cells on knee osteoarthritis. METHODS： The bone marrow mesenchymal stem cells were transfected with Lenti-Sox9-EGFP in vitro. The model of murine knee osteoarthritis was established by cutting off the anterior cruciate ligament. Thirty model mice were randomly divided into three groups, as normal saline group, bone mesenchymal stem cell group and Sox9-transfected bone mesenchymal stem cell group. 0.1 m L of normal saline, 0.1 m L of normal saline containing non-transfected bone marrow mesenchymal cells（non-transfected group）, or 0.1 m L of normal saline containing Sox9-transfected bone marrow mesenchymal cells（Sox9-transfected group） was injected into the knee joint cavity of mice in the corresponding group, respectively. After 4, 8, 12 weeks, the repair of articular cartilage lesions was evaluated by toluidine blue and immunohistochemical staining. RESULTS AND CONCLUSION： The lesions of articular cartilage were more serious in the normal saline group, compared with the other two groups, and the difference became more obvious over time. Damaged articular cartilage was improved in the non-transfected group, but the improvement was less than that in the Sox9-transfected group. Immunohistochemistry staining revealed that in the Sox9-transfected group, the positive type II collagen expression was stronger than that in the other two groups, but this positive expression was decreased over time in all the three groups. These results suggest that Sox9-transfected bone marrow mesenchymal stem cells promote the repair of damaged cartilage in mice with knee osteoarthritis.