NEP1-40基因修饰的神经干细胞移植对脊髓损伤大鼠行为学恢复的影响

Effect of NEP1-40 Gene Modified Neural Stem Cell Transplantation on the Behavior Recovery of Rats after Spinal Cord Injury

目的通过与单纯的神经干细胞移植进行比较,探讨NEP1-40基因修饰的神经干细胞移植对脊髓损伤大鼠行为学恢复的影响。方法从孕18 d的Sprague-Dawley（SD）大鼠胚胎大脑皮质中分离获得原代神经干细胞,体外培养及传代后采用巢蛋白免疫荧光染色进行鉴定。采用已成功构建的慢病毒载体将NEP1-40基因导入第3代神经干细胞内建立NEP1-40基因修饰的神经干细胞。将30只SD大鼠在第9胸椎水平进行脊髓右侧半切后随机分为3组,每组各10只,伤后第7天在损伤局部分别植入细胞培养液（损伤组）、神经干细胞（NSC组）及NEP1-40基因修饰的神经干细胞（NEP1-40-NSC组）。另取10只仅行第8~10胸椎椎板切除,设置为假手术组。细胞移植前和移植后8周通过Basso-Beattle-Bresnahan（BBB）运动功能评分及网格测试评价神经功能恢复情况。结果细胞移植后8周,BBB测试及网格测试结果显示：损伤组大鼠BBB评分最低且网格摔倒次数最多,单纯神经干细胞移植组BBB评分较之增高且网格摔倒次数减少（P〈0.01）,而NEP1-40基因修饰的神经干细胞移植组BBB评分最高且网格摔倒次数最少,和前两组相比差异均有统计学意义（P〈0.01）。结论 NEP1-40基因修饰能进一步提高单纯神经干细胞移植对于大鼠脊髓损伤后行为功能恢复的治疗效果,为研究神经干细胞移植治疗脊髓损伤提供了新的思路和实验依据。

Objective To investigate the behavioral recovery of spinal cord injury（SCI） rats that received transplantation of NEP1-40 gene-modified neural stem cells. Methods Neural stem cells（NSCs） were derived from the cortex tissue of rat embryo at the age of 18 days and identified by Nestin immunofluorescence. The lentiviruses were transduced to NSCs to construct NEP1-40 gene modified NSCs. Spinal cords of 30 Sprague-Dawley rats were hemisected at the nineth thoracic vertebrae level. The rats were randomly assigned to three groups. Cell culture medium, NSCs and NEP1-40 gene-modified NSCs were transplanted into the lesion site of rats of SCI group, NSCs group and NEP1-40-NSCs group respectively 7 days after injury. Additional 10 rats served as blank control group（sham group）, which only received laminectomy. Following transplantation, behavior tests including Basso, Beattie, Bresnahan（BBB） Locomotor Rating Scale and grid test were utilized to evaluate spinal cord functional recovery. Results Behavior tests 8 weeks after cells transplantation showed that the rats in SCI group got worst results, the BBB scores improved and the grid drop times reduced significantly in NSCs transplantation group（P 〈 0.01） and behavioral test outcomes were best in the NEP1-40 gene-modified NSCs group（P 〈 0.01）. Conclusions NEP1-40 gene modification can significantly improve the behavioral recovery of SCI rats that received transplantation of pure neural stem cells. It can provide a new idea and reliable experimental base for the study of NSCs transplantation for spinal cord injury.