人脐血干细胞移植促进大鼠脊髓损伤神经恢复

Transplantation of Human Umbilical Cord Stem Cells Improves Neurological Function Recovery after Spinal Cord Injury in Rats

目的观察移植人脐血CD３４＋干细胞是否可以存活、分化、促进脊髓损伤的行为和功能恢复。方法２６只Wister大鼠随机分成移植组和对照组。移植组行脊髓半切术并移植５-溴脱氧尿核苷（Brdu）标记的脐血CD３４＋细胞，对照组行脊髓半切术后注射PBS液。采用改良Tarlov评分标准对移植组和对照组所有大鼠在术前和术后２４h、１、２、３、４周进行运动功能评价。组织学和免疫组化分析移植细胞的定位和分化情况。结果移植后在脊髓病理切片中出现Brdu标记人脐血细胞，激光扫描共聚焦显微镜通过免疫荧光双标检测到７％Brdu阳性细胞表达神经胶质元纤维酸性蛋白（GFAP），２％Brdu阳性细胞表达神经元核抗原（NeuN）。神经功能检测发现１周后移植组功能恢复较对照组具有显著性差异（P＜０．０５）。结论移植人脐血干细胞可以促进脊髓损伤的行为和功能恢复，为神经损伤治疗提供了有用的细胞源。

Objective To study whether intraspinally transplanted human cord blood CD34 + cells can survive,differentiate,and improve neurological functional recovery after spinal cord injury in rats.Methods Rats were randomly divided into two groups.One group of rats was subjected to spinal cord left-hemisec tion and transplanted with human cord blood CD34 + cells labeled by bromodeoxyuridine(BrdU);The other group was carried by left-hemisection with injection of PBS (control group).The neurological function was determined before and24h,1,2,3and4weeks after spinal cord injury and cell transplantation using the modified Tarlov score.The distribution and differentiation of transplanted human cord blood cells in vivo in rat spinal cord were evaluated by histological and immnuhistochemical analysis.Results Functional recovery determined by modified Tarlov score was significantly improved in the group receiving human cord blood CD34 + cells compared with the control group(P<0.05).Moreover,human cord blood CD34 + cells were found to survive in rat spinal cord microenvironment,with the expression of the neural nuclear specific protein (NeuN)in2%BrdU-reactive human cells and of the astrocytic specific protein glial fibrillary acidic protein (GFAP)in7%BrdU-reactive human cells.Conclusions Intraspinally administered human cord blood CD34 + cells can survive,differentiate,and improve functional recovery after spinal cord injury in rats.Transplantation of human cord blood cells may provide a novel strategyfor the treatment of neural injury.