A chimeric brain model to study human neurological diseases

 描述(由申请人提供)：本申请的首要目标是开发一个模型系统来评估候选药物对活体人类神经元的影响。因此，我们建议将CDKL5突变的IPSC衍生的神经元移植到小鼠的大脑中，并用候选药物暴露于动物，以评估它们对完全成熟的人类神经元的影响。利用我们开发嵌合小鼠大脑的专业知识，该模型将允许我们在体内进行后续研究，以适应不同时间点的分子和细胞研究，并促进新药筛选方法。本文提出的方法也可用于研究神经元网络，主要是研究大脑微环境对人类神经元的影响。我们将策略性地使用CDKL5突变的IPSC来源的神经元作为概念证明，考虑到患者的早期发病及其体外明确的形态表型。CDKL5基因的突变与X连锁的神经发育障碍有关，包括严重的智力低下和最常在婴儿出生后几个月出现的早发性癫痫。体外研究表明，CDKL5对于树突棘的正确发生和维持以及突触的形成都是必需的。将CDKL5突变的IPSC来源的神经干细胞移植到小鼠大脑中，将使我们能够了解人类神经元的神经形成/成熟，研究它们在体内的行为，并对疾病的发展给予无与伦比的洞察。更广泛地说，使用这种嵌合的大脑策略，我们将进一步评估铅化合物对受损神经元的影响，环境更接近患者。人类嵌合小鼠的大脑最终可能成为研究疾病机制的更具预测性的临床前翻译模型。因此，我们的具体目标是：目标1-将人CDKL5突变的鼻咽癌细胞移植到小鼠脑内并在体内鉴定分化的神经元；目标2-确定候选药物对嵌合脑模型中人CDKL5突变的神经元的影响。我们的主要目标是开发一种模型，在活体环境中长期研究人类神经元的发育。该策略还允许我们评估候选药物如何影响整合在小鼠大脑中的活的人类神经元。在这里，我们提出了一种在活体内研究人类神经元的新方法。这样的策略将作为测试新的治疗药物的原则证明 在更全面、更可靠的差异化系统中。我们坚信，我们的努力将对该领域产生深远影响，并推动其更上一层楼。

 DESCRIPTION (provided by applicant): The overarching goal of this application is to develop a model system to evaluate the impact of candidate drugs on human neurons in vivo. Thus, we propose to transplant CDKL5-mutant iPSC-derived neurons into a mouse brain and expose the animal with candidate drugs to evaluate their impact on fully mature human neurons. Taking advantage of our expertise to develop chimeric mouse brains, this model will allow us to perform follow up studies in vivo, to accommodate both molecular and cellular studies at different time-points and to facilitate new drug screening methods. The approach proposed here can also be used to study neuronal networks and, mainly, the effects of brain microenvironment on human neurons. We will strategically use CDKL5-mutant iPSC-derived neurons as a proof of concept considering the patients' early disease onset and its clear morphological phenotype in vitro. Mutations in the CDKL5 gene have been connected to X-linked neurological developmental disorders, including severe mental retardation and early-onset seizures most often seen in the first few months of age. In vitro studies showed that CDKL5 is required for correct genesis/maintenance of dendritic spines and also for synapse formation. Transplanting CDKL5-mutant iPSC-derived NPCs into a mouse brain will allow us to understand the neural formation/maturation of human neurons, investigate their behavior in vivo, and give unparalleled insight into disease progression. More broadly, using this chimeric brain strategy we will further evaluate the effect of lead compounds on the compromised neurons in an environment closer to that one found in patients. Human chimeric mice brains could ultimately serve as a more predictive pre- clinical translational model for studying disease mechanisms. Thus, our specific Aims are: Aim 1 - To transplant human CDKL5-mutant NPCs into a mouse brain and characterize differentiated neurons in vivo; and Aim 2 - To determine the impact of candidate drugs on human CDKL5-mutant neurons in the chimeric brain model. Our main goal is to develop a model to study the development of human neurons for long periods of time in an in vivo setting. The strategy also allows us to evaluate how candidate drugs can affect live human neurons integrated in a mouse brain. Here we propose a new approach to study human neurons in vivo. Such strategy will serve as a proof-of-principle for testing new therapeutic drugs in a more holistic and reliable differentiation system. We truly believe that our efforts will deepy impact and push the field to the next-level.