脑源性神经生长因子促进脑梗死后小鼠内源性神经干细胞的增殖及向神经元分化  

Brain-derived neurotrophic factor promotes the proliferation of endogenous neural stem cell and its differentiation into neurons in mice with cerebral infarction

作　　者：臧大维[1] 刘娟[2] 左宪华[1] Surindar Cheema 

机构地区：[1]天津市第一中心医院神经内科,天津市300192 [2]天津市第一中心医院检验科微生物室,天津市300192 [3]墨尔本大学医学院Howard Florey研究所

出　　处：《中国临床康复》2006年第33期4-6,共3页Chinese Journal of Clinical Rehabilitation

摘　　要：目的:探讨脑源性神经生长因子是否能促进脑梗死后小鼠内源性神经干细胞的活跃,能否刺激其分化成神经元。方法:实验于2004-07/2005-02在墨尔本大学完成。选取10周龄纯种C57BL/6J小鼠24只,分为盐水对照组、脑源性神经生长因子治疗组,每组雌雄各6只。①两组均采用结扎左侧大脑中动脉远心端法建立脑梗死模型,同时采用Matsushita描述的方法监测大脑中动脉供血区的血流量,血流量降低至少75%为有效。②脑源性神经生长因子治疗组于梗死后24h给予脑起源神经营养因子治疗,用药方式采用ALZET锇药物泵缓慢释放。将500μg/kg脑起源神经营养因子溶解于生理盐水中,加入到ALZET泵中,可在28d内持续缓慢释放药物。盐水对照组于梗死后24h给予等量生理盐水。③造模前后对两组小鼠运动功能进行Rotarod测试,记录小鼠在Rotarod上的停留时间。采用双重免疫荧光组化及共焦计数系统检测方法,对两组小鼠内源性神经干细胞的数量、密度及其分化方向进行评估。结果:①运动功能测试结果:与梗死前比较,两组小鼠在梗死后第1周均表现出明显的运动功能下降。但梗死后第2,3,4周,脑起源神经营养因子治疗组小鼠在Rotarod上的停留时间延长,运动功能的恢复明显优于盐水对照组,差异有显著性意义(P<0.01)。②组织切片双重免疫荧光染色结果:两组小鼠脑内均出现免疫荧光阳性表达的内源性神经干细胞,主要分布在病灶周围,在损伤侧的对侧也出现表达。脑起源神经营养因子治疗组的表达数量明显高于盐水对照组。③内源性神经干细胞的激活情况:梗死4周后,两组小鼠脑内都出现内源性神经干细胞的再表达,脑起源神经营养因子治疗组内源性神经干细胞数较盐水对照组明显增加,约4.2倍。同时脑起源神经营养因子治疗组分化为神经元的比例明显高于盐水对照组(36%,15%),分化为星形胶质细胞AIM： To evaluate whether brain-derived neurotrophic factor （BDNF） can up-regulate the re-expression of endogenous neural stem cells and the differentiation into the neurons in the mouse model of cerebral infarction. METHODS： The experiment was performed at University of Melbourne from July 2004 to February 2005. Totally twenty-four C57BL/6J mice at aged 10-week post natal were used and divided into two groups： saline control group （Female： 6; Male： 6） and BDNF treated group （Female： 6; Male： 6）. ①The left middle cerebral artery （MCA） was blocked caudally in both groups to establish cerebral infarction models and the Matsushita measuring method was used to monitor the blood flow of the lesioned region supplied by MCA.. 75%.reduction of blood flow should be reached in the lesioned region. ②At 24-hour post lesion, the BDNF treated group accepted BDNF administration, which was delivered into cerebral spinal fluid （CSF） using an ALZET osmium pump design. BDNF was dissolved in saline at the dosage of 500 μg/kg and injected into this pump, which could release the solution consistently in the following 28 days. Those in the saline control group accepted the same volume of saline at hour 24 after cerebral infarction. ③All mice were tested in motor function using Rotarod before and after the lesion. The time that the mice-stay on the running bar was collected. Double labeling of immunohistochemistry and the confocal counting system were used in this study to estimate the number and density of endogenous neural stem cells in the mouse model before and after BDNF administration. The differentiation fate of these cells was also revealed. RESULTS： ①Result of motor functional test： At 1-week post lesion, the significant decrease in motor function was detected in both groups, at 2, 3, 4-week post lesion, the running time on Rotarod in BDNF treated group showed significant increase compared with saline control group, representing the better recovery in motor function, and the dif

关 键 词：干细胞 脑源性神经生长因子 神经元 小鼠 

分 类 号：R394.2[医药卫生—医学遗传学]