Novel Stem Cell and Mouse Models to Study Frontotemporal Dementia

描述（申请人提供）：几种脑部疾病是由蛋白质聚集引起的；仅额颞叶痴呆 (FTD) 和阿尔茨海默病就影响了近 500 万美国人。尽管小鼠模拟了疾病的各个方面，但它们可能几个月甚至几年都不会生病。相反，源自这些小鼠的细胞培养系统可以在几天或几周内提供有关疾病机制的信息，从而加速疾病治疗的发现。总体假设是，产生携带导致疾病的突变或基因组合的干细胞系将为研究发病机制提供有价值的研究工具。具体来说，将研究含有神经球的中枢神经系统干细胞在体外重现亲本小鼠品系表型的功效。微管相关蛋白 tau 基因突变的小鼠可以准确模拟人类 FTD 的生化、组织学和行为方面。疾病的显着细胞表型、tau 蛋白的过度磷酸化和聚集可以通过传统的蛋白质检测方法进行追踪，并将用作标记物来评估神经球及其分化后代作为模型的效用。目标 1 的重点是确定神经球是否表现出与亲代品系中观察到的相同的 tau 病理突变特异性时间序列，并研究转基因表达如何影响增殖、存活和分化。结果将与表达人类编码的野生型 tau 基因的神经球和小鼠进行比较。由 tau 磷酸化事件引起的小鼠模型疾病的一个陷阱是内源性小鼠 tau 可能会抑制人类编码的 tau 磷酸化。因此，目标 2 的重点是检验内源性小鼠 tau 的表达在体内和体外改变人类转基因编码的 tau 磷酸化和聚集的假设。突变型和野生型人类 tau 转基因都将转移到小鼠 tau 缺失背景中。小鼠和神经球将被表征并与相应的小鼠 tau 野生型系进行比较。如果神经球重现其亲本小鼠品系的体内表型，它们可以作为高通量测定系统来研究参与疾病发病机制的其他基因和小分子。

DESCRIPTION (provided by applicant): Several brain diseases arise from protein aggregation; fronto-temporal dementia (FTD) and Alzheimer's disease alone affect nearly 5 million Americans. Though mice model aspects of disease, they may not become ill for months or even years. Instead, cell culture systems derived from these mice may provide information about disease mechanisms in days or weeks thereby speeding discovery of disease treatment. The overall hypothesis is that generating stem cell lines carrying mutations or combinations of genes leading to diseases will provide valuable research tools to study pathogenesis. Specifically, central nervous system stem cell containing neurospheres will be investigated for their efficacy in recapitulating parent mouse strain phenotypes in vitro. Mice with mutations in the microtubule associated protein tau gene accurately model biochemical, histological, and behavioral aspects of human FTD. Prominent cellular phenotypes of disease, hyperphosphorylation and aggregation of the tau protein, can be tracked with conventional protein detection methods and will be used as markers to assess the utility of neurospheres and their differentiated progeny as models. The focus of Aim 1 is to determine if neurospheres exhibit the same mutation-specific temporal sequence of tau pathology observed in their parental strains, and investigate how proliferation, survival, and differentiation are affected by transgene expression. Results will be compared to neurospheres and mice expressing the human encoded wild type tau gene. One pitfall to mouse modeled diseases arising from tau phosphorylation events is that endogenous mouse tau may inhibit human encoded tau phosphorylation. Therefore the focus of Aim 2 is to test the hypothesis that expression of endogenous mouse tau alters human transgene-encoded tau phosphorylation and aggregation in vivo and in vitro. Both mutant and wild type human tau transgenes will be transferred to a mouse tau null background. Mice and neurospheres will be characterized and compared to corresponding mouse tau wild type lines. If neurospheres recapitulate in vivo phenotypes of their parent mouse strains, they may serve as high through-put assay systems to investigate other genes and small molecules involved in disease pathogenesis.