hUC-MSCs对大鼠膝骨软骨缺损的修复作用

The effect of hUC-MSCs to repair rat knee cartilage defects

目的研究关节腔注射人脐带来源间充质干细胞(hUC-MSCs)对大鼠膝关节软骨缺损的修复作用及部分机制。方法舒泰50麻醉大鼠后,在大鼠股骨滑车沟采用电钻造成2 mm×2 mm的骨软骨缺损。术后一周将动物分为模型组和hUC-MSCs移植组,另设假手术组作为对照。hUC-MSCs移植组关节腔注射hUC-MSCs(2×10^(6)个细胞,50μl),假手术组和模型组关节腔注射等量生理盐水作为对照。大鼠在细胞移植后第10周麻醉处死。通过体视显微镜、组织病理学和免疫荧光分析评估hUC-MSCs对受损软骨的修复作用。体外培养大鼠原代软骨细胞,Transwell法检测hUC-MSCs对软骨细胞的增殖与迁移作用。结果关节腔注射hUC-MSCs可提高ICRS评分,缺损部位修复相对完整,有大量软骨细胞和基质填充,具有明显的修复作用。HE、番红固绿及Masson染色结果显示,hUC-MSCs组损伤部位与周围正常关节软骨组织差异无显著性。与模型组相比,hUC-MSCs组Ⅰ型胶原(ColⅠ)水平下降,Ⅱ型胶原(ColⅡ)水平上升,增殖细胞核抗原(PCNA)阳性细胞数增加,性别决定区域Y相关的高迁移率族框9(SOX9)表达水平及入核增加。体外共培养结果显示,hUC-MSCs可促进软骨细胞增殖和迁移。结论关节腔移植hUC-MSCs可促进关节软骨缺损修复,其机制可能与保护软骨基质和促进软骨细胞增殖迁移有关。

Objective To investigate the partial mechanism and effect of transplanting with human umbilical cordderived mesenchymal stem cells(hUC-MSCs)to repair articular cartilage defects in a rat model.Methods Critical-sized osteochondral defects were created in the trochlear grooves of rat femurs.The hUC-MSCs were transplanted into the defect of experimental knees.Sham group and model group knees were transplanted with saline.The effects of articular cartilage repair were evaluated at 10 weeks after surgery with International Cartilage Repair Society(ICRS)repair score,histological examination and immunohistochemical analysis.The effects of hUC-MSCs on the proliferation and migration of chondrocytes were detected by Transwell in vitro.Results After transplanting with hUC-MSCs,the articular surfaces of the defect sites were changed smoother thanthose of the model group,and the cellular morphology and arrangement were also improved in Safranin O staining or Masson staining results.Similar to surrounding normal articular cartilage tissue after treatment for 10 weeks,and the ICRS repair score was significantly elevated.In addition,hUC-MSCs treatment could promote chondrocytes proliferation,increase the expression of type Ⅱ(Col Ⅱ)collagen and decrease the level of type Ⅰ collagen(Col Ⅰ)in the articular defect site.Meanwhile,the increased protein expression of SOx9 and protein transportation to the nucleus were observed after treatment with hUC-MSCs for 10 weeks.In vitro,chondrocytes could be proliferated and migrated after co-cultured with hUC-MSCs.Conclusion Transplanting with hUC-MSCs can promote cartilage repair,and its role maybe related to the protection of the cartilage matrix and the promotion of chondrocyte proliferation and migration.