骨髓间质干细胞与胚胎嗅鞘细胞联合移植治疗大鼠脊髓损伤的实验研究

目的：观察人骨髓间质干细胞（MSCs）与胚胎嗅鞘细胞（OECs）联合移植治疗大鼠脊髓损伤的效果，探讨共移植的OECs对MSCs分化的影响。方法：采用Allen’s法制作大鼠脊髓损伤模型．随机分为MSCs移植组（A组）、OECs移植组（B组）、MSCs与OECs联合移植组（C组）及PBS注射组（D组），术后1-5周采用BBB评分、经颅磁刺激运动诱发电位及组织学方法检查脊髓损伤修复情况。结果：术后2周起，A、B、C组BBB评分和诱发电位潜伏期与D组比较恢复明显，C组与A、B组相比亦有显著性差异（P〈0．05），术后5周时C组损伤区有较密的神经轴突分布，近端可见大量成束再生轴突；A、B组损伤区及近端再生轴突分布稀疏；D组损伤区及近端少见轴突。C组移植的MSCs中Nestin及NF表达阳性的比率较A组高（P〈0.05）。结论：联合移植OECs可促进MSCs向神经元方向转化，提高MSCs分化为神经元的比例；MSCs与OECs可以在脊髓损伤修复中发挥协同作用，联合细胞移植是提高脊髓损伤修复效果的可行方法。

Co-graft of mesenchymal stem cells and embryo olfactory ensheathing cells promoting the neurological function recovery in rat with spinal cord injury

Objective:To test the efficacy of co-graft of embryo olfactory ensheathing cells(OECs)and bone marrow stromal cells(MSCs)in rat with thoracic spinal cord injury,and investigate the neuron differentiation of MSCs after transfusion in vivo.Method:Rat model with spinal cord injury(SCI)were established following Allen's methods and all rats were randomly divided into 4 groups.Groups protocol were defined as MSCs transplantation alone(group A),OECs alone(group B),MSCs together with OECs(group C)and phosphate buffered solution(PBS)alone(group D).Basso-Beattie-Bresnahan(BBB)scale,transcranial magnetic motor-evoked potentials(tcMMEP)responses and histological analyses were taken to evaluate the repairing effect until 5 weeks after operation.Result:From 2 weeks after SCI,the improvement of lower limbs' function and injured spinal cord's conduction in group A?B?C was greater than those in group D,and among cell graft groups,group C owned the greatest improvement(P<0.05).There were bundles of regenerated axons at transitional zone and injured zone in group C,however,less axons were observed in group A and B,and even no axons could be found in group D 5 weeks after injury.Also at 5th week,there were more MSCs-derived Nestin positive cells and MSCs-derived NF positive cells in co-grafted group than in MSCs grafted alone group(P<0.05).Conclusion:Co-graft of OECs and MSCs can contribute to the survival and neuron differentiation of implanted MSCs,it also can promote the neurological function recovery synergistically,all these suggest an effective way to improve the cell-based treatment.