Neural Stem Cell Survival and Function in Aging Mice an*

描述（由申请人提供）：脑室下区（SVZ） 哺乳动物大脑的侧脑室和海马体含有 多能神经干细胞（NSC）的群体。 这些细胞不断地 不同步分裂，产生替代干细胞和 增殖祖细胞 在进一步的分裂和迁移之后， 增殖祖细胞向多个神经谱系分化。 它 已经假设NSC在整个神经发育过程中参与神经发生。 生命的有机体和有助于维持健康的大脑 和/或其功能，包括存储器。 有可能神经干细胞经历年龄- 可能导致功能障碍或导致病理的相关变化 包括帕金森氏症或阿尔茨海默氏症。 这一目标 建议是定义存在的变化，细胞周期参数和 神经干细胞和增殖祖细胞群在衰老过程中的功能 用老鼠做模型来研究大脑。 在可能的情况下，这些变化也将 在人体样本中进行评估。 目的1：双核苷酸类似物标记 DNA复制许可因子的免疫学检测方法 MCM 2将用于定义具有复制能力的长期标签 保留细胞（假定的干细胞）和增殖祖细胞内， 不同年龄小鼠的SVZ。 每个细胞群的细胞周期参数 将根据这些数据定义单元格。 这组实验将定义 干细胞和增殖祖细胞浓度和细胞增殖的变化 骑自行车的时间作为年龄的函数，并作为基线， 问题研究 此外，我们将测试DNA表达的效用， 聚合酶亚单位增殖细胞核抗原（PCNA）作为替代物 对于核苷酸类似物掺入， 人口 最后，在SVZ中的MCM 2和PCNA表达的变化， 人脑切片的海马区将进行分析，免疫学分析， as a function函数of age年龄. 目标2：利用上述方法监测国家安全理事会， 增殖祖细胞参数，我们将确定是否改变， 这些细胞在衰老过程中的特性是细胞自主的或依赖于细胞的生长。 使用NSC移植技术的老化大脑的环境。 目标3： 将构建其中标记MCM 2基因的转基因小鼠模型 通过掺入增强型绿色荧光蛋白（EGFP）或 他莫昔芬诱导的Cre-雌激素受体融合。 这些模型将允许： 1)确定是否所有静止的神经干细胞都表达MCM 2， 或者，如果存在亚群MCM 2阴性细胞，并且2） 的NSC人群进行跟踪。 监控数据 体内神经干细胞后代的命运将使我们能够确定年龄- 这些细胞的分化潜能发生相关变化。

DESCRIPTION (provided by applicant): The subventricular zone (SVZ) of the lateral ventricles and the hippocampus of the mammalian brain contain populations of multipotent neural stem cells (NSCs). These cells continually divide, asynchronously, resulting in a replacement stem cell and a proliferative progenitor. Following additional division and migration, proliferative progenitors differentiate towards multiple neural lineages. It has been hypothesized that NSCs participate in neurogenesis throughout the life of the organism and contribute to maintaining the health of the brain and/or its functions, including memory. It is possible that NSCs undergo age- related changes that may lead to dysfunction or contribute to pathologies including Parkinson's or Alzheimer's diseases. The objectives of this proposal are to define changes in the presence, cell cycle parameters and function of the NSC and proliferative progenitor populations during aging in the brain using the mouse as a model. Where possible, such changes will also be assessed in human samples. Aim 1: A double nucleotide analog labeling method, and immunological detection of the DNA replication licensing factor MCM2 will be utilized to define replication competent long-term label retaining cells (putative stem cells) and proliferative progenitors within the SVZ of mice of different ages. Cell cycle parameters for each population of cells will be defined from these data. This set of experiments will define changes in the stem cell and proliferative progenitor concentrations and cell cycling times as a function of age and serve as a baseline for additional studies. Additionally, we will test the utility of expression of the DNA polymerase subunit proliferating cell nuclear antigen (PCNA) as a surrogate for nucleotide analog incorporation in defining the proliferative progenitor population. Finally, changes in MCM2 and PCNA expression in the SVZ and hippocampal regions of human brain sections will be assayed, immunologically, as a function of age. Aim 2: Using methods described above to monitor NSC and proliferative progenitor parameters, we will determine if changes in the properties of these cells during aging are cell autonomous or dependent on the environment of the aging brain using NSC transplantation techniques. Aim 3: Transgenic mouse models will be constructed in which the MCM2 gene is marked by incorporation of either enhanced green fluorescent protein (EGFP) or a tamoxifin inducible Cre-estrogen receptor fusion. These models will allow: 1) determination of whether all quiescent neural stem cells express MCM2 or, alternatively, if a sub-population MCM2 negative cells exists and 2) the fate of NSC populations to be followed, respectively. The ability to monitor the fates of neural stem cell progeny in vivo will allow us to determine if age- related changes in the differentiation potentials of these cells occur.