Foxc2基因修饰骨髓间充质干细胞修复实验性兔股骨头坏死

Transplantation of Foxc2-transfected bone marrow mesenchymal stem cells for experimental femoral head necrosis in rabbits

背景:通过髓芯减压能有效延缓早期骨坏死的自然进程,但是并没有彻底解决股骨头坏死的修复问题,最终仍可能导致股骨头塌陷,发生骨坏死。目的:探讨Foxc2基因修饰骨髓间充质干细胞复合明胶海绵移植对兔实验性股骨头缺血性坏死的治疗效果。方法:取40只新西兰大白兔制备股骨头坏死模型,MRI筛选制备成功模型24只,随机分为4组,空白对照组4只不作任何处理,髓芯减压组4只单纯减压,GFP治疗组8只在减压同时植入GFP基因转染骨髓间充质干细胞与明胶海绵复合材料,Foxc2治疗组8只在减压同时植入Foxc2基因转染骨髓间充质干细胞与明胶海绵复合材料。植入后第1,2,4周用ELISA方法测定植入局部组织中Foxc2蛋白表达水平。植入后4,8,12周进行髋部MRI扫描,然后取股骨头标本组织切片行苏木精-伊红染色,观察骨长入情况,并对12周标本行骨形态计量学测定及透射电镜观察。结果与结论:1植入后1,2,4周Foxc2治疗组股骨头局部有Foxc2蛋白的高表达,明显高于GFP治疗组。2植入后4,8,12周髓芯减压组、GFP治疗组只有较少新骨形成,12周时减压孔道有纤维性骨痂形成;Foxc2治疗组均有明显成骨,12周时坏死区被完全修复。3植入后12周Foxc2治疗组MRI表现为股骨头形态及信号均正常,髓芯减压组、GFP治疗组股骨头可见信号减低。4通过体外转染使骨髓间充质干细胞过表达Foxc2目的基因,利用髓芯减压移植到激素性股骨头坏死动物体内具有较好疗效。

BACKGROUND： Core decompression can delay early osteonecrosis of the femoral head, but cannot completely repair the necrotic femoral head. Eventually, femoral head collapse, even bone necrosis, will occur. OBJECTIVE： To explore the curative effect of implantation of gelatin sponge carrying Foxc2-transfected bone marrow mesenchymal stem cells on the repair of experimental femoral head necrosis in rabbits. METHODS： Forty New Zealand white rabbits were selected, and femoral head necrosis models were prepared successfully in 24 of 40 rabbits. Then, model rabbits were randomized into four groups： blank control group（n=4） with no treatment, core decompression group（n=4）, GFP group（n=8） subjected to core decompression and implantation of gelatin sponge carrying GFP-transfected bone marrow mesenchymal stem cells, and Foxc2 group（n=8） subjected to core decompression and implantation of gelatin sponge carrying Foxc2-transfected bone marrow mesenchymal stem cells. At 1, 2, 4 weeks after implantation, ELISA was used to detect Foxc2 protein levels in the transplanted region. At 4, 8, 12 weeks after implantation, MRI scan of the hip was performed, and femoral head tissues were taken and sliced into sections for hematoxylin-eosin staining to observe bone growth. At 12 weeks after implantation, histomorphometry measurement and transmission electron microscope observation were carried out. RESULTS AND CONCLUSION： At 1, 2, 4 weeks after implantation, Foxc2 was highly expressed in the femoral head in the Foxc2 group, which was significantly higher than that in the GFP group. At 4, 8, 12 weeks, only a few of new bone formed in the core decompression group and GFP group; at 12 weeks, fibrous tissues formed in the decompression channel. New bone formation was evident in the Foxc2 group, and at 12 weeks, the necrotic region was repaired completely. MRI findings showed normal femoral head morphology and signals in the Foxc2 group at 12 weeks, but there were decreased signals of the femoral head in the core decompression group and GFP group. These findings indicate that Foxc2-transfected bone marrow mesenchymal stem cell transplantation via core decompression has good curative effects on experimental femoral head necrosis in animals.