神经干细胞对缺血性脑损伤的反应能力(英文)

Reactive ability of nerve stem cell to ischemic brain injury

背景:当中枢神经系统受损伤时,Nestin蛋白的重新表达可能增加细胞抗损伤的能力,有利于损伤灶的修复。目的:通过永久性脑缺血神经干细胞迁移及Nestin蛋白表达的变化,探讨永久性脑缺血情况下神经干细胞的反应性。设计:以实验动物为研究对象,随机对照的验证性研究。单位:一所专科学校的解剖学教研室和一所大学的解剖学教研室。材料:实验于1999-10/2001-01在西安交通大学医学院人体解剖学教研室进行,选择健康SD大鼠75只。随机分为正常对照组、实验组和假手术组,每组25只。各组动物均在术后1,3,7,14和28d,断头取脑,每个时间点5只大鼠。方法:以永久性大鼠脑缺血为模型,采用免疫组化染色方法,观察脑缺血1,3,7,14和28d时,神经干细胞的迁移及其神经干细胞标记物Nestin蛋白的变化。主要观察指标:①免疫组化染色结果。②SZa区Nestin阳性细胞在正常和缺血后不同时间点脑组织中的迁移距离。③缺血后不同时间点缺血区附近Nestin阳性细胞数的变化。结果:通过Nestin免疫组化染色,发现正常脑组织中神经干细胞主要位于室管膜下区。室管膜下区的神经干细胞在缺血后沿胼胝体腹侧向缺血区方向发生了迁移。其中,缺血7d时达到最远。缺血灶附近在缺血1d时就出现较多的Nestin阳性细胞,缺血3d以后逐渐减少。结论:神经干细胞对缺血性脑损伤有一定的反应能力,Nestin蛋白表达于缺血附近可能是一种对损伤的保护机制。

BACKGROUND： When central nervous system is injured, re-expression of nestin protein may enhance the anti-injury ability of cells and be advantageous to the repair of focus of injury. OBJECTIVE： To explore the reaction of nerve stem cell （NSC） in permanent brain ischemia through NSC migration and the change of nestin protein expression. DESIGN： A randomized and controlled verification research with experimental animals as subjects. SETTING： Anatomy teaching and research offices in a training school and a university. MATERIALS： The experiment was done in the Teaching and Research Office of Humane Anatomy in Medical College of Xi ＇an Jiaotong University from October 1999 to January 2001. Totally 75 healthy SD rats were selected and randomly divided into normal control group, experiment group and sham-operation group. Twenty-five animals were in each group. Heads of animals were cut and brain was got out at the 1^st, 3^rd, 7^th, 14^th and 28^th days after operation, 5 animals at each time. METHODS： The model was rats with permanent cerebral ischemia, hnmunohistochemical dyeing methods were used to observe NSC migration, change of marker of NSC and nestin protein at the 1^st, 3^rd, 7^th, 14^th and 28^th day after cerebral ischemia. MAIN OUTCOME MEASURES： ①Results of immunohostochemical dyeing. ②Migration length of nestin^＋ cells in anterior subentricular zone （SZa） region of brain tissue at normal status and at different time points after cerebral ischemia. ③Number variation of nestin^＋ cells at different time poits after ischemia near the ischemic region. RESULTS： Through nestin immunohistochemical dyeing, it was found that NSC in normal brain tissue mainly existed in subependymal zone （SEZ） region. NSC of SEZ migrated in the direction of ischemic region along ventri-corpus callosum after ischemia. Among them, it reached the farthest at the 7^th day after ischemia. More nestin^＋ cells appeared near ischemic region at the 1^st day, and then reduced little by little 3 days later. CONCLUSION： NSC has certain reactive ability to ischemic brain injury. Expression of nestin protein near ischemic region may be a kind of protection to injury.