Endogenous barcoding to determine complex dynamics of adult neurogenesis in aging and Alzheimer's disease

摘要 成年人类和动物海马区的新神经元与几种认知有关 功能。这些功能因新神经元的丢失或产生不足而受到严重损害。神经元 是在经历了一系列漫长的转变后产生的，包括激活、增殖、消除和 神经干细胞及其后代的分化。已经提出了相互竞争的假说来描述 这些步骤是如何执行的。这些假设暗示着不同的，有时相互矛盾的，蓝图 从干细胞到神经元的转变，以及当这些蓝图被干扰时的不同结果 衰老或疾病。阿尔茨海默病(AD)对大鼠海马神经发生有显著的不良影响 在人类和动物模型中，这种下降被认为与认知功能障碍直接相关 在公元后观察到。阿尔茨海默病神经发生的变化及其与AD的区别 衰老引起的变化可能揭示缓解甚至逆转AD相关认知的新方法 传送室。这一目标具有挑战性，不仅是因为系统的复杂性，还因为 目前可用于追踪干细胞及其后代的方法固有的局限性。 我们最近开发了一种新的内源条形码方法来确定谱系轨迹 以及成年小鼠大脑中神经干细胞的分化轨迹。此外，我们还开发了一种 分裂干细胞及其后代亚群的组合多标记标记新技术。现在 我们建议应用这些新方法来确定AD和衰老在基础上引起的变化 研究神经干细胞的分裂和分化方案，并研究如何减轻这些变化。 在我们的第一个具体目标中，我们将把Polylox条形码盒和相关基因引入基因组 对于AD小鼠模型，应用重组诱导的内源性条形码，并进行条形码分析 结合单细胞转录组分析作为一种新的方法来确定分裂，分化， 以及单个神经干细胞的谱系，以及阿尔茨海默病和衰老造成的变化。在我们的第二个 目的：我们将应用我们的新的细胞分裂多标记标记技术来进一步确定 阿尔茨海默病和衰老引起的成人神经发生和扰动。这些方法结合在一起，将提供 解剖衰老和阿尔茨海默病引起的神经发生扰动的新方法。最后，在第三个目标中， 我们将确定这些变化如何被不同治疗方式中使用的药物改变，使用它们 作为进一步揭示AD和衰老诱导变化的实验手段。

ABSTRACT New neurons in the adult human and animal hippocampus have been implicated in several cognitive functions. These functions are profoundly impaired by the loss or insufficient production of new neurons. Neurons are produced after a prolonged series of transitions including the activation, proliferation, elimination, and differentiation of neural stem cells and their progeny. Competing hypotheses have been proposed to describe how these steps are executed. These hypotheses imply divergent, sometimes contradicting, blueprints of the transitions from stem cells to neurons, as well as different outcomes when these blueprints are perturbed by aging or disease. Alzheimer's disease (AD) has a dramatic adverse effect on hippocampal neurogenesis in humans and in animal models, and this decrease is thought to be directly linked to the cognitive dysfunction observed in AD. Identifying the changes in neurogenesis induced by AD and differentiating them from the changes induced by aging may reveal new means of mitigating or even reversing AD-associated cognitive impartment. This goal is challenging not only because of the complexity of the system, but also because of the limitations inherent in currently available approaches for tracing stem cells and their progeny. We have recently developed a novel approach of endogenous barcoding to determine the lineage trajectory and differentiation trajectories of neural stem cells in the adult mouse brain. In addition, we have developed a new technique for combinatorial multitag labeling of subpopulations of dividing stem cells and their progeny. Now we propose applying these new approaches to identify the changes that AD and aging induce in the basic scheme of neural stem cell division and differentiation and to examine how those changes can be mitigated. In our first specific aim, we will introduce the Polylox barcode cassette and related genes into the genome of mouse models of AD, apply recombination-induced endogenous barcoding, and perform barcode analysis integrated with single-cell transcriptome analysis as a novel approach for determining the division, differentiation, and lineages of individual neural stem cells, as well as the changes inflicted by AD and aging. In our second aim, we will apply our new technique of multitag labeling of dividing cells to further determine the dynamics of adult neurogenesis and perturbations introduced by AD and aging. Together, these approaches will provide a new means of dissecting the perturbations in neurogenesis provoked by aging and AD. Finally, in our third aim, we will determine how these changes are modified by drugs used in different therapy modalities, using them here as experimental instruments for further revealing the AD- and aging-induced changes.