静脉移植骨髓间充质干细胞对大鼠脊髓损伤后轴突再生的作用

Effect of intravenous administration of bone marrow stromal cells on the regeneration of axons after spinal cord injury

目的:研究静脉移植骨髓间充质干细胞(bonemarrowstromalcells,BMSC)对脊髓损伤后轴突再生的影响。方法:体外分离、培养、扩增、纯化、BrdU标记10只同种异体SD大鼠的BMSC,WD法制成完全性截瘫的同种大鼠脊髓损伤动物模型。制模后7d随机分为A、B、C三组,A组22只,作为BMSC移植组,经鼠尾静脉移植2×106/ml的BMSC悬液1ml;B组22只,作为对照组,移植1mlL-DMEM液;C组22只,作为空白手术对照组。移植后1、2、3、4、5、6周用BBB评分评估各组后肢运动功能;移植后2、3、6周组织学及免疫组织化学观察并检测损伤段脊髓内生长相关蛋白-43(growth-associatedprotein-43,GAP-43)、神经丝蛋白200(neurofilament-200,NF200)的表达。结果:移植后3周开始,A组的BBB评分在各观察时间点明显高于B组、C组,移植后6周维持在较稳定水平,而B、C组在伤后3周开始维持在较稳定水平;在移植后2、3、6周,A组GAP-43、NF200的表达明显高于高于B组、C组,6周时开始下降,而B组与C组在移植后2、3、6周的表达均维持在相对恒定的水平。结论:大鼠脊髓损伤后静脉移植BMSC能使损伤段脊髓GAP-43、NF200表达上调,促进脊髓损伤后轴突再生和神经功能改善。

Objective：To study the effects of intravenous administration of bone marrow stromal celIs（BMSC） on the regeneration of axons after spinal cord injury.Method：BMSC were harvested and isolated from 10 adult Sprague-Dawley （SD） rats,all these cells were cultured,purified,expanded and labeled with bromodeoxyuridine （BrdU）.66 adult SD rats were subjected to weight-drop impact causing complete paraplegia and then randomly assigned into 3 groups 7 days after injury.22 rats in group A were treated with 2×10^6 BMSC cultured in lml phosphate-buffered saline by tail vein,22 rats in group B were treated with lml L-DMEM by tail vein and 22 in group C were regarded to sham group.The expression of growth-associated protein-43 （GAP-43）,neurofilament （NF200） around the contused spinal cord was measured respectively at 2,3 and 6 week after transplantation.The motor function of three groups was evaluated respectively by the Basso-Beattie- Bresnahan （BBB） scors at 7,14 21,28,35,42 days after injury.Result：The BBB score in group A was significantly higher than that in group B or group C from 3 to 6 weeks after transplatation.The expression of GAP-43 and NF200 was significantly higher than that in group B or group C at 2,3 and 6 week after intravenous administration,and its level in group A lowed down after 6 weeks.Conclusion：Intravenous administration of BMSC can upregulate the expression of GAP-43 and NF200 ,and facilitate regeneration of axons which may be useful in the treatment of spinal cord injury.