大鼠骨髓间充质干细胞静脉移植对脊髓损伤的修复作用

目的初步探讨骨髓间充质干细胞（BMSCs）静脉移植对脊髓损伤后神经功能恢复和神经修复的影响。方法体外培养BMSCs，改良Allen法制备大鼠脊髓损伤模型，经尾静脉移植Brdu标记的BMSCs，损伤后24h、移植后1、3、5周评价实验动物的神经功能状况，并检测BMSCs在体内迁移、存活以及分化情况，电子显微镜观察组织形态学变化。结果移植的BMSCs在宿主损伤脊髓中聚集并存活，3～5周后有部分移植细胞表达神经元特异性烯醇化酶（NSE）、神经丝蛋白（NF）、微管相关蛋白（MAP2）；BMSCs静脉移植组大鼠运动功能改善，BBB评分高于对照组（P〈0．05）；5周后组织学观察，与对照组相比移植组损伤区脊髓结构较完整。结论BMSCs经静脉移植后可向脊髓损伤处聚集并存活分化，促进神经修复及神经功能的恢复。

Role of bone marrow stem cells by vein transplantation in repair of spinal cord injury in rats

Objective To investigate whether the bone marrow stem cells(BMSCs)by intravenous infusion can enter the spinal cord,promote the regeneration of injured spinal cord and reduce its neurological functional deficits.Methods BMSCs from adult rats were cultured in vitro.Rats were induced by improved Allen's method to establish the spinal cord models.BMSCs labeled with Brdu or phosphate buffered saline(as controls)were infused into tail vein.Neurological functions were evaluated by using the Basso-Beattie-Bresnahan(BBB)Scale 24 h after injury and 1,3 and 5 weeks after transplantation.Sections of tissue were analyzed with immunohistochemistry and electron microscope to observe the migration,survival,differentiation and histomorphological changes of BMSCs.Results The transplanted BMSCs survived and aggregated at the injured spinal cord,and a few cells expressed neuron specific enolase(NSE),neurofilament protein(NF),and microtubule-associated protein(MAP2)3~5 weeks after transplantation.There was a significant improvement in neurological functions of rats treated with BMSCs transplantation and the scores of BBB in the BMSCs transplanted group were higher than those in the control group(P<0.05).Five weeks after transplantation,the injured spinal cord was restored better in the BMSCs transplanted group than that in the control group.Conclusion Transplanted BMSCs are able to survive and assemble at the injured area of spinal cord,and a few transplanted cells express the phenotypes of nerve cells.Intravenous administration of BMSCs promotes the restoration of injured spinal cord and improves neurological functions.