自体移植的大鼠骨髓间充质干细胞在脊髓损伤处的存活及分化

目的观察自体移植的骨髓间充质干细胞(BMSC)在脊髓损伤(SCI)处的存活及向神经细胞分化情况。方法将36只雄性SD大鼠随机分为PBS注射组(PBS组)和BMSC自体移植组(BMSC组)。BMSC组大鼠在术前均进行自体BMSC分离培养。2组大鼠均采用改良Allen撞击装置制备T9水平的SCI模型,PBS组于损伤处注射PBS,BMSC组注射第4代自体BMSC。于移植后2、3、5周采用Basso-Beattie-Bresnahan(BBB)评分法进行运动功能评分;移植后2、3、5周取损伤部位脊髓,采用Hoechst33342染色法观察移植细胞存活情况,同时行免疫荧光化学染色检测自体移植的BMSC中微管相关蛋白2(MAP-2)及胶质纤维酸性蛋白(GFAP)的表达情况。结果移植后2、3、5周,BMSC组大鼠BBB评分均高于PBS组,差异有统计学意义(P<0.05)。移植后2、3、5周,BMSC组大鼠损伤处脊髓有不同数量Hoechst33342标记细胞存活,其中2周时细胞存活较多,5周时细胞存活较少;移植后2、3周,未检测到移植细胞表达MAP-2及GFAP,5周时检测到部分移植细胞表达MAP-2和GFAP。结论SCI后立即进行移植的自体BMSC可在损伤处存活,部分存活细胞可向神经元和星形胶质细胞方向分化,促进大鼠后肢运动功能的恢复。

Survival and differentiation of autologous bone marrow mesenchymal stem cells in spinal cord injury site in rats

Objective To observe the survival and differentiation of autologous bone marrow mesenchymal stem cells (BMSCs) in spinal cord injury(SCI) site in rats. Methods Thirty-six male SD rats were randomly divided into BMSCs autologous transplantation group(BMSC group) and PBS injection group(PBS group). BMSCs were isolated from the rats of BMSC group and cultured. After the SCI models were established with Allen''s impact device in the 2 groups,PBS and BMSC groups received injection of PBS fluid and the 4th generation autologous BMSCs at the injury site,respectively. Basso-Beattie-Bresnahan(BBB) score was used to detect the motor function at 2,3,and 5 weeks after transplantation. At 2,3 and 5 weeks after transplantation,the SCI site was taken and the survival of the transplanted cells was observed by Hoechst33342 staining. Meanwhile,the expression of microtubule associated protein 2(MAP-2) and glial fibrillary acidic protein(GFAP) were detected by immunofluorescence staining. Results The BBB score of BMSC group was significantly higher than that of PBS group at 2,3 and 5 weeks,with a statistical significance(P<0.05). At 2,3 and 5 weeks after transplantation,BMSCs labeled with Hoechst33342 were observed around the injection spot more cells survive at 2 weeks after transplantation and less cells at 5 weeks;At 2 and 3 weeks after transplantation,those surviving BMSCs did not express MAP-2 and GFAP,but the MAP-2 and the GFAP could be detected in some of surviving BMSCs at 5 weeks after transplantation. Conclusion At the moment of SCI,autologous BMSCs can survive in the SCI site and a few of them can differentiate into neuron-like cells and astrocyte-like cells,and play an important role in promotion of recovering the motor function of the hind limb.