摘要
背景:成年哺乳类动物中枢神经系统存有神经前体细胞,其基本生物学特性主要包括多向细胞分化和维持自身数量稳定。目的:观察中枢神经系统损伤后神经前体细胞增殖和迁移的反应过程,探讨神经前体细胞在中枢神经系统损伤修复中的作用,设计:随机对照实验。单位:北京市神经外科研究所病理生理研究室。材料:实验在北京市神经外科研究所病理生理研究室完成。选择成年Wistar大鼠67只,随机分为正常对照组7只,损伤后1,3,7,14,30d组,每个损伤组12只。以上每个损伤组再随机分为人工脑脊液组2只,碱性成纤维细胞生长因子组5只和神经营养因子-3组5只。方法:各损伤组制作液压冲击性脑损伤模型,正常对照组仅开颅,不致伤。各损伤组每次腹腔内注射BrdU50mg/kg,处死前2h注入最后一次,其中损伤后1d和3d组每天注入3次,损伤后7d和14d组每天注入1次。碱性成纤维细胞生长因子组每日灌注碱性成纤维细胞生长因子总量360ng,神经营养因子-3组每日灌注神经营养因子-3总量240ng,人工脑脊液组每日灌注液中不含碱性成纤维细胞生长因子和神经营养因子-3,灌注4μL。免疫组织化学方法动态检测各组大鼠脑组织中Nestin和BrdU的表达。BrdU标记方法确定增殖的神经前体细胞;Nestin的表达用于确定神经前体细胞。主要观察指标:Brdu,GFAP+/Brdu+和GFAP-/Brdu+在各组大鼠脑损伤不同时相中的表达。结果:67只大鼠均进入结果分析。①与正常对照组相比较,伤侧皮质、海马及室下区的Nestin阳性细胞数于伤后1d明显增多[(3.1±1.1),0个/视野;(5.5±0.9),(1.3±0.8)个/视野;(8.1±0.9),(2.3±0.8)个/视野,P<0.05],7d达高峰[(7.5±1.2),(10.2±1.5),(13.6±1.2)个/视野],30d消失[0,(1.2±0.9),(2.1±0.8)个/视野]。②伤侧皮质、海马及室下区的BrdU阳性细胞数于伤后3d达高峰[(12.6±1.5),(9.9±1.1),(13.4±1.0)个/视野],而7d以后逐渐减少。③室下区BrdU阳性细胞及Nestin阳性细胞经胼胝体向对侧迁移。结论:液压冲击性脑损伤可激发成年大鼠脑皮质、海马及室下区神经前体细胞增殖及迁移,其中Nestin阳性细胞数于伤后7d最多,BrdU阳性细胞数于伤后3d最多。
BACKGROUND： Neural precursor cells exist in the central nervous system （CNS） of adult mammals, characterized fundamentally by such biological properties of muhipotential differentiation and capability of maintaining their stable quantity. OBJECTIVE： To investigate the proliferation and migration of the neural precursor cells in adult rat brain following fluid percussion injury （FPI）, and explore their role in the repair of CNS damage. DESIGN： Randomized controlled experiment. SETITNG： Laboratory of Pathophysiology, Beijing Institute of Neurosurgery. MATERIALS： This experiment was carried out at the Laboratory of Pathophysiology, Beijing Institute of Neurosurgery. Totally 67 adult Wistar rats were randomized into a control group （n=7） and 5 FPI groups （n=12） sampled 1, 3, 7, 14, and 30 days after FPI, respectively. Each FPI group was further divided into artificial cerebral spinal fluid （CSF） group （n=2）, basic fibroblast growth factor （bFGF） group （n=5） and neurotrophin-3 （NT-3） group （n=5）. METHODS： Lateral fluid percussion brain injury was induced in rats in the FPI group and the rats in the control group were only subjected to craniotomy without percussion. The rats in FPI groups were given intraperitoneal injection of bromodexyuridine （BrdU） at the dosage of 50 mg/kg for three times a day in 1-and 3-day FPI groups, but only once a day in 7-and 14-day groups, with the final dose given 2 hours before sacrifice. The rats in bFGF subgroup and NT-3 subgroup were given bFGF at the total daily dose of 360 ng and NT-3 of 240 ng, respectively, while those in artificial CSF subgroup received perfusion fluid of 4 μL without bFGF or NT-3 every day. The dynamic expressions of nestin and BrdU in the rat brain were determined with immunocytochemistry. BrdU labeling method was used to identify the differentiated neural progenitor cells, and nestin expression was used to identify the neural progenitor cells. MAIN OUTCOME MEASURES： Expressions of Brdu, glial fibrillary acidic protein （GFAP）^＋/Brdu^＋ and GFAP^-/Brdu^＋ cells in the rat brain of each group at various time points. RESULTS： Totally 67 rats entered the result analysis. ① In comparison with the control group, nestin-positive cells in the cortex, hippocampus and subventricular zone on the injured side was obviously increased at lday after FPI （3.1±1.1 vs 0, 5.5±0.9 vs 1.3±0.8 and 8.1±0.9 vs 2.3±0.8 in each visual field, respectively, P 〈 0.05）, reaching the peak on day 7 （7.5±1.2, 10.2±1.5, and 13.6±1.2 in each visual field, respectively） and disappeared till day 30 （0, 1.2±0.9, and 2.1±0.8 in each visual field, respectively）. ② BrdU-positive cells in the cortex, hippocampus and subventricular zone on the injured side increased to the highest level 3 days after FPI （12.6±1.5, 9.9±1.1, and 13.4±1.0 in each visual field, respectively）, but gradually decreased since day 7. ② Nestin-and BrdU-positive cells in the subventricular zone gradually migrated to the opposite side across the corpus callosum. CONCLUSION： FPI can stimulate the proliferation and migration of neural progenitor cells in adult rat brain, such as in the cortex, hippocampus and subventricular zone, where the nestin-positive cells is the most 7 days after the injury, but BrdU-positive cells is the most 3 days after the injury.
出处
《中国临床康复》
CSCD
北大核心
2005年第38期182-184,F0003,共4页
Chinese Journal of Clinical Rehabilitation
基金
中国博士后科学基金资助(2001-12325)~~
