NT-3基因修饰的嗅鞘细胞移植对自身免疫性脑脊髓炎大鼠神经修复及功能恢复的影响

Treatment of transplantation of NT-3 gene modified olfactory ensheathing cells on experimental autoimmune encephalomyelitis in rats

目的探讨神经营养因子-3（NT-3）基因修饰的嗅鞘细胞（OECs）对自身免疫性脑脊髓炎（EAE）大鼠神经修复及运动功能恢复的促进作用。方法构建Lewis大鼠EAE模型，采用完全随机化法分为对照组、OECs组及OECs-NT-3组，每组20只，分别将生理盐水、OECs、OECs-NT-3移植入大鼠侧脑室内，每日进行神经功能缺损评分（NDS）评估大鼠肢体功能恢复情况，应用免疫组织化学检测及辣根过氧化物酶（HRP）逆行示踪技术对EAE神经纤维修复进行形态学观察。结果细胞移植后，OECs-NT-3组大鼠神经功能评分明显低于OECs组，差异有统计学意义（P〈0．05）；第28天，大鼠体内OECs-NT-3存活数量较多，可向病灶远端扩散、迁徙；OECs-NT-3组单位面积内的神经纤维数目[第28天，（38．8±3．4）个]明显高于OECs组[第28天，（32．5±2．8）个]（P〈0．05）；OECs-NT-3组HRP标记的神经元数目多于OECs组，差异有统计学意义（P〈0．01）。结论NT-3基因修饰的OECs可在EAE大鼠体内存活、迁移，并可促进神经纤维再生，减轻皮质神经元的逆行性损伤，改善EAE大鼠的运动功能。

Objective To explore the effects of transplantation of NT-3 gene modified olfactory ensheathing cells （OECs） on nerve function of rats with experimental autoimmune encephalomyelitis （EAE）. Methods The experimental autoimmune encephalomyelitis model was established in Lewis rats. The animals were randomly divided into 3 group：blank control group（ transplantation of saline）, OECs transplanted group （ transplantation of OECs） , and OECs-NT-3 transplanted group（ transplantation of NT-3 modified OECs）. The neurological function was assessed and recorded every day. The migration and distribution of transplanted cells were observed. The nerve regeneration was valued in the aspect of morphological structure by means of immunohistochemistry and retrograde tracing technique of horseradish peroxidase （HRP）. Results The neurological functional score of OECs-NT-3 transplanted group was obviously inferior to OECs transplanted group after transplantation （ P 〈 0. 05 ）. A large number of OECs-NT-3 survived and migrated with axon in OECs-NT-3 transplanted group at Day 28. The number of nerve fibers in one microscopic field was much more in OECs-NT-3 transplanted group （ 38.8 ± 3.4, Day 28 ） than those in OECs transplanted group （32.5±2.8, Day 28） （P 〈 0.05）.The number of cortex neurons labeled by HRP in OECs-NT-3 transplanted group were significantly higher than those in OECs transplanted group, （P 〈 0. 01 ）. Conclusion NT-3 gene modified OECs have better capacities of survival and migration in EAE rats. The transplanted OECs-NT-3 can promote the regeneration of axon, reduce the injury of cortical neurons and improve the motor functions of EAE rats.