跑台训练对成年小鼠脊髓损伤后髓鞘结构修复的影响  

Effects of treadmill training on myelin structure repair after spinal cord injury in adult mice

作　　者：苏虹 潘璐 朱莹 王昀杭 刘媛 杨策 李森 王海燕 龙在云 殷樱[1] 谭波涛[1] SU Hong;PAN Lu;ZHU Ying;WANG Yunhang;LIU Yuan;YANG Ce;LI Sen;WANG Haiyan;LONG Zaiyun;YIN Ying;TAN Botao(Department of Rehabilitation Medicine,the Second Affiliated Hospital of Chongqing Medical University,Chongqing,400042,China;State Key Laboratory of Trauma,Burns and Combined Injuries,Department of Special Environment War Wound Prevention and Treatment,Institute of Surgery Research,Army Medical Center of PLA,Chongqing,400042,China)

机构地区：[1]重庆医科大学附属第二医院康复医学科,重庆400010 [2]陆军特色医学中心野战外科研究部特殊环境战伤防治研究室创伤,烧伤与复合伤国家重点实验室,重庆400042

出　　处：《陆军军医大学学报》2023年第2期111-120,共10页Journal of Army Medical University

基　　金：国家自然科学基金青年科学基金(82002377);重庆市自然科学基金面上项目(cstc2019jcyj-msxmX0195);创伤烧伤与复合伤国家重点实验室开放基金资助项目(SKLKF202111)。

摘　　要：目的 研究跑台训练对小鼠T10脊髓轻度挫伤后背侧皮质脊髓束(dorsal corticospinal tract,dCST)髓鞘结构修复的影响。方法 实验采用成年C57/BL雌性小鼠。12只用于模型验证;另30只按随机数字表法分为(n=10):假手术组(只接受椎板切除)、脊髓损伤(spinal cord injury,SCI)组和跑台训练组[进行单侧(左侧)脊髓打击伤]。跑台训练组于术后1周开始进行为期4周的跑台训练(参数:12 m/min,30 min/次,1次/d,5 d/周)。取材前2周,对各组小鼠进行初级运动皮质(primary motor cortex,M1)注射生物素化葡聚糖胺(biotinylated dextran amine,BDA)以示踪dCST。4周训练结束后进行组织取材。采用免疫荧光染色检测血小板源性生长因子受体α(platelet-derived growth factor receptor α,PDGFRα)、Ki67蛋白、少突胶质细胞转录因子2(oligodendrocyte transcription factor 2,Olig2)、腺瘤性结肠息肉病蛋白(adenomatous polyposis coli protein,APC/CC1)、髓鞘碱性蛋白(myelin basic protein,MBP)表达情况;透射电镜(transmission electron microscope,TEM)观察左侧dCST区髓鞘化情况;在伤前、损伤后1周及训练后1、2、4周对各组小鼠进行左后肢运动功能评估(basso mouse scale,BMS)。结果 免疫荧光染色显示,SCI组左侧dCST区内PDGFRα/Ki67双阳性细胞数量与PDGFRα阳性细胞数量的比值、Olig2/APC/CC1双阳性细胞数量与Olig2阳性细胞数量的比值以及MBP的平均荧光强度较假手术组显著减少(P<0.01),而跑台训练组较SCI组有所增加(P<0.01)。TEM结果显示,SCI组左侧dCST区G-ratio较假手术组显著增加(P<0.01),而跑台训练组较SCI组有所降低(P<0.01)。在损伤后各个时间点中,跑台训练组的BMS评分有所改善,但与SCI组相比差异无统计学意义。结论 跑台训练能够促进SCI小鼠左侧dCST区中OPCs增殖、分化和OLs的成熟,增加髓鞘相关蛋白的表达并促进髓鞘结构的修复。Objective To investigate the effects of treadmill training on the repair of myelin structure of dorsal corticospinal tract(dCST) in mice with T10 spinal cord mild contusion.Methods Twelve adult C57/BL female mice were used to construct and verify the model of spinal cord mild contusion,and another 30 mice were randomly divided into 3 groups(n=10):sham group,spinal cord injury(SCI) group,and treadmill training group.The mice of SCI and treadmill training groups were given unilateral(left) spinal cord contusion,while the sham group was given laminectomy only.A 4-week training scheme was conducted for the treadmill training group 1 week after SCI surgery(parameters:12 m/min,30 min/session,1 time/day,5 d/week).The primary motor cortex(M1) of mice in each group was injected with biotinylated dextran amine(BDA) to trace dCST 2 weeks before sampling,followed by the collection of tissue samples when the 4-week training finished.Then the expression levels of platelet-derived growth factor receptor α(PDGFRα),Ki67 protein,oligodendrocyte transcription factor 2(Olig2),adenomatous polyposis coli protein(APC/CC1) and myelin basic protein(MBP) were detected by immunofluorescence assay.Transmission electron microscopy(TEM) was also used to observe the myelination in the left dCST area.Moreover,Basso Mouse Scale(BMS) was performed in each group to evaluate the motor function of left hindlimb before injury,1 week after injury and 1,2,and 4 weeks after training.Results Immunofluorescent labeling showed that the ratio of PDGFRα/Ki67 double positive cells to the total number of PDGFRα positive cells,the ratio of Olig2/APC/CC1 double positive cells to the total number of Olig2 positive cells,as well as the mean fluorescence intensity of MBP in the left dCST area of the SCI group were significantly lower than those of the sham group(P0.05).Conclusion Treadmill training can facilitate the proliferation and differentiation of oligodendrocytes precursor cells(OPCs),improve the maturation of oligodendrocytes(OLs) in the left dCST regio

关 键 词：脊髓损伤 跑台训练 髓鞘修复 运动功能 

分 类 号：R-332[医药卫生] R455R651.2