骨髓间充质干细胞移植对脊髓损伤大鼠脑源性神经营养因子表达的影响

背景:近年来关于骨髓间充质干细胞移植对脊髓损伤修复方面的研究较多,但目前相关机制尚不清楚.目的:观察间充质干细胞移植对大鼠脊髓损伤后脑源性神经营养因子表达的影响.设计、时间及地点:随机对照动物实验,于2003-04/07在中国医科大学神经解剖学实验室完成.材料:选取鼠龄3个月的SD大鼠64只,雌雄不拘,体质量250～300 g,随机抽取4只大鼠用于骨髓间充质干细胞的分离与培养,其余60只用于制备脊髓横断损伤模型.方法:60只大鼠随机抽签法分为3组,细胞移植组(n=24):脊髓损伤后第7天,无菌条件下以微量注射缓慢注入含骨髓间充质干细胞(1×109L-1)的培养液5μL至脊髓损伤区;PBS组(n=24):注入等量(5μL)磷酸盐缓冲液体;空白对照组(n=12):注入生理盐水5μL.主要观察指标:分别于造模后7,14,28 d取材,观察骨髓间充质干细胞的形态变化;免疫组织化学法检测间充质干细胞移植后大鼠脊髓损伤区脑源性神经营养因子的表达.结果:60只SD大鼠均进入结果分析.10代以后细胞增殖能力有所减弱,胞体变得扁平,若加入碱性成纤维细胞生长因子,则可维持其增殖能力和形态.大鼠脑源性神经营养因子在正常大鼠脊髓组织中有一定表达,细胞移植后第7,14,28天,细胞移植组脑源性神经营养因子表达均高于PBS组和空白对照组(P＜0.05);空白对照组与PBS组脑源性神经营养因子表达无明显差异(P＞0.05).结论:骨髓间充质干细胞在移植后通过上调脑源性神经营养因子的表达从而促进轴突的再生,可能是治疗脊髓损伤的重要机制.

Influence of bone marrow mesenchymal stem cell transplantation on brain-derived neurotrophic factor expression in rats with spinal cord injury

BACKGROUND: Transplantation of bone marrow mesenchymal stem cells (MSCs) improves functional recovery after spinal cord injury (SCl), but the mechanisms involved remain unclear.OBJECTIVE: To observe the effects of MSCs transplantation on the expression of brain-derived neurotrophic factors (BDNF) in rats after SCl.DESIGN, TIME AND SETTING: Randomized, controlled, animal experiment. The study was performed at the Laboratory of Neuroanatomy, China Medical University from April to July 2003.MATERIALS: A total of 64 SD rats, aged 3 months, of either gender, weighing 250-300 g, were used. Of them, 4 were randomly selected to isolate and culture MSCs, and the remaining were used to establish SCl models.METHODS: The 60 rats were randomly divided into 3 groups. Seven days after SCl, MSCs group (n=24) was transplanted with 5 μL culture solution containing 1×109/L MSCs to the injury site using micro-injection; PBS group (n=24) was transplanted with 5μ L PBS, and the blank control group (n=12) with 5μ L normal saline.MAIN OUTCOME MEASURES: The rats were sacrificed at 7, 14, and 28 days post-surgery. MSCs morphology was observed and the expression of BDNF at the lesion areas was examined by immunohistochemistry,RESULTS: All 60 rats were included in the final analysis. After ten subcultures, the cell proliferative capacity was reduced, and cell body turned to flat; the MSCs protiferation and morphous could be maintained by adding basic fibroblast growth factor.Transplantation of MSCs enhanced the expression of BDNF compared with PBS and blank control groups at 7, 14, and 28 days post-surgery (P ＜ 0.05); white no significant difference was found between PBS and blank control groups (P ＞ 0.05).