不同时间点静脉移植嗅鞘细胞修复脊髓损伤

背景:嗅鞘细胞具有促进轴突再生、为受伤的宿主细胞提供营养支持以及调节炎症反应的能力,是修复脊髓损伤具有潜力的细胞。目的:探讨通过静脉移植嗅鞘细胞治疗脊髓损伤的最佳移植时间窗。方法:SPF雄性SD大鼠30只,采用脊髓半横断建立大鼠脊髓损伤模型,并随机分为5组:脊髓损伤后注射嗅鞘细胞1 d移植组、3 d移植组、7 d移植组、10 d移植组及PBS对照组。应用荧光量子点标记嗅鞘细胞;分别于1,3,7,10 d时间点通过尾静脉移植应用量子点标记的嗅鞘细胞;PBS对照组脊髓损伤后注射PBS。注射后1 d取损伤处的脊髓;应用小动物成像仪测定不同时间点转移到损伤处荧光的数值,通过荧光的强度衡量转移到损伤处细胞的量;应用嗅鞘细胞Anti-p75 NGF Receptor抗体做损伤处脊髓的免疫组织化学。实验方案经宁夏医科大学动物实验伦理委员会批准(编号:2017-073)。结果与结论:①荧光量子点可以标记嗅鞘细胞;②荧光测定结果与免疫组织化学染色结果:1,3,7,10 d时间点通过尾静脉移植的嗅鞘细胞均有细胞转移到损伤处,7 d移植的嗅鞘细胞转移到损伤处的最多;③结果说明,脊髓损伤不同时间点注射的嗅鞘细胞均可以转移到脊髓损伤处,损伤后7 d移植的嗅鞘细胞转移到损伤处的细胞数量最多,可以作为移植的最佳时间窗。

Intravenous transplantation of olfactory ensheathing cells at different time points for repairing spinal cord injury

BACKGROUND:Olfactory ensheathing cells promote axonal regeneration,provide nutritional support for the injured host cells and regulate inflammation reaction,which possess potential for spinal cord injury repair.OBJECTIVE:To explore the optimal time window for intravenous transplantation of olfactory ensheathing cells in the treatment of spinal cord injury.METHODS:Thirty male SPF level rats were used to establish the rat models of spinal cord injury by spinal cord hemisection.Rat models were then randomly divided into five groups:1-,3-,7-and 10-day olfactory ensheathing cell transplantation and PBS groups.Olfactory ensheathing cells were labeled with fluorescent quantum dots.PBS was injected into the rats in the PBS group after spinal cord injury.The injured spinal cord was removed at 1 day after injection.A small animal imager was used to measure the fluorescence transferred to the lesion at different time points.The number of cells transferred to the lesion was measured based on the intensity of fluorescence.The Anti-p75 NGF Receptor antibody was used for immunohistochemistry detection of the injured spinal cord.The study was approved by the Ethics Committee of Animal Laboratory of Ningxia Medical University,No.2017-073.RESULTS AND CONCLUSION:Fluorescent quantum dots could label olfactory ensheathing cells.Results of fluorescence assay and immunohistochemistry indicated that transplanted olfactory ensheathing cells were transferred to the lesion at 1,3,7 and 10 days.Most cells were transferred to the lesion at 7 days.Therefore,these results indicate that olfactory ensheathing cells transplanted at different time points after spinal cord injury can be transferred to the lesion,with a number peak at 7 days that is the best time window for cell transplantation.