神经干细胞移植联合康复训练对脊髓损伤大鼠Nogo—A及NgR蛋白表达的影响

Effects of rehabilitation training combined with bone marrow mesenchymai stem cell-derived neural stem cells transplantation on the expression of Nogo-A and NgR proteins after spinal cord injury

目的观察神经干细胞移植联合康复训练对脊髓损伤大鼠Nogo-A及NgR蛋白表达的影响。方法共选取80只SD大鼠，采用改良Allen法制成大鼠T10节段脊髓损伤模型，将其随机分为联合治疗组、细胞移植组、康复训练组及模型组。联合治疗组及康复训练组于制模后次日给予滚筒训练与跑台训练，每周训练5d；联合治疗组与细胞移植组于造模后第7天时，将体外培养的骨髓源性神经干细胞移植人大鼠受损脊髓中。每周采用BBB评分法对各组大鼠后肢运动功能进行评定；于干细胞移植后第1，3，7天时每组各取5只大鼠处死，采用Western—blot法检测各组大鼠术后不同时间点脊髓中Nogo．A及NgR蛋白表达。结果从脊髓损伤后第2周开始，发现联合治疗组大鼠BBB评分在各时间点均明显优于其他各组（P〈0．05），第5周时康复训练组BBB评分明显优于模型组（P〈0．05）。随着时间推移，各组大鼠Nogo—A及NgR蛋白起始均呈现高表达、随后快速下降等特点，以干细胞移植第7天时联合治疗组的降低幅度最显著，细胞移植组次之，康复训练组与模型组间差异无统计学意义（P〉0．05）。结论康复训练联合神经干细胞移植治疗脊髓损伤大鼠具有协同效应，能进一步抑制受损脊髓中Nogo—A、NgR蛋白表达，促进脊髓损伤大鼠肢体功能恢复。

Objective To study the effects of rehabilitation training combined with the transplantation of bone marrow mesenchymal stem cells-derived neural stem cells （BMSC-D-NSCs） on the expression of Nogo-A and NgR protein in rats after spinal cord injury （SCI）. Methods The spinal cords of eighty Sprague-Dawley rats were injured using a modified Alleng impactor （H = 25 mm） at T10. The injured rats were randomly divided into a combi- nation therapy group which was given rehabilitation training and cell transplants, a cell graft group, a rehabilitation training group and a control group. At the 7th day post SCI, BMSC-D-NSCs were transplanted into the injured spinal cords of the rats in the combination therapy and cell graft groups. Hindlimb movement was assessed using the Basso- Beattie-Bresnahan （BBB） scale every week, and protein was extracted from the injured spinal cord tissue for Nogo-A and NgR determination by Western blotting at the 1st, 3rd and 7th day after cell transplantation. Results The av- erage BBB score of the rats in the combination therapy group was significantly higher than that of the other groups from 2 weeks post transplantation. The scores in the rehabilitation training group were significantly higher than in the control group from the 5th week post transplantation. Western blotting showed high expression of Nogo-A and NgR protein 24 h post surgery, but these declined with time. For Nogo-A there was a significant difference among the groups at all three time points. In the combination therapy group the expression declined to a minimum by the 7th day. For NgR protein there was no significant difference between the 1st and 3rd day in any group. Conclusions Rehabilitation training combined with BMSC-D-NSC transplantation can have a synergistic effect on functional recovery from SCI. It can down regulate the expression of Nogo-A and NgR protein.