嗅鞘细胞移植对脊髓损伤大鼠的作用

THE EFFECT OF OLFACTORY ENSHEATHING CELL TRANSPLANTATION ON RATS WITH SPINAL CORD INJURY

目的探讨嗅鞘细胞（OECs）移植治疗脊髓损伤的作用及其机制。方法 Wistar大鼠30只,随机分为3组,每组10只。A组仅行脊髓损伤,B组脊髓损伤1d后移植OECs,C组脊髓损伤7d后移植OECs,移植后8周进行组织学观察、电生理检查,并行脑源性神经营养因子（BDNF）、神经营养因子3（NT-3）、神经生长因子（NGF）蛋白、血管内皮生长因子（VEGF）水平测定以及BBB评分。结果伊红-苏木精染色可见B组和C组脊髓大量细胞增生,瘢痕组织及空洞明显少于A组;A组结构恢复不明显。A组大鼠的运动诱发电位波幅明显降低,B组和C组大鼠运动诱发电位较A组明显改善,差异有统计学意义（F=8.049,P〈0.05,）。B组、C组BDNF、NGF、NT-3、VEGF蛋白表达量较A组明显增高,C组较B组各蛋白表达量增高,差异有统计学意义（F=46.317~78.000,P〈0.05）。大鼠脊髓损伤后BBB评分明显下降,OECs移植后时间的长短、组别的不同以及两者之间的相互作用对OECs移植后脊髓损伤大鼠的BBB评分均有显著影响（F_（时间）=188.494,F_（组别）=183.919,F_（交互）=50.332,P〈0.05）。结论 OECs移植治疗能够通过分泌神经营养因子和加速微血管再生改善微环境,促使大鼠损伤的轴突再生和部分神经功能恢复。

Objective To study the efficacy of olfactory ensheathing cell（OEC）transplantation for spinal cord injury（SCI）and its mechanism. Methods Thirty Wistar rats were evenly randomized to groups A,B and C.The rats in group A received SCI only;those in group B received OEC transplantation one day after SCI;and those in group C received OEC transplantation seven days after SCI.Eight weeks after OEC transplantation,histology was observed,and electrophysiologic study conducted.The levels of brain-derived neurotrophic factor（BDNF）,neurotrophic factors 3（NTF-3）,nerve growth factor（NGF）and vascular endothelial growth factor（VEGF）were detected and BBB scoring done. Results With hematoxylin-eosin staining,a large number of cell proliferation in spinal cord could be seen in groups B and C,and scar tissue and cavity were less as compared with group A.The amplitude of motion evoked potential in group A obviously declined,and that in groups B and C improved,the difference being statistically significant（F=8.049,P〈0.05）.The expressions of BDNF,NGF,NT-3,and VEGF in groups B and C were higher than that in group A,and that in group C were higher than that in group B（F=46.317-78.000,P〈0.05）.After SCI,BBB score in rats significantly lowered.The length of time after OEC transplantation,different groups and the interaction between the two markedly impacted the BBB score（F_（time）=188.494,F_（group）=183.919,F_（interaction）=50.332,P〈0.05）. Conclusion Olfactory ensheathing cell transplantation can precipitate regeneration of injured neurites and restore part of the nerve function in rats through secreting neurotrophic factors,accelerating microvascular regeneration and improving microenvironment.