Understanding Down Syndrome Brain Development Using Human iPSC-Based Mouse Chimeras

使用基于人类 iPSC 的小鼠嵌合体了解唐氏综合症大脑发育

• 批准号: 10179682
• 负责人: Peng Jiang
• 金额: $ 41.76万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10179682
• 关键词: Affect; Animal Behavior; Animals; Behavior; Behavioral; Biological; Brain; CRISPR/Cas technology; Candidate Disease Gene; Cells; Chimera organism; Chromosome 21; Cognitive deficits; Development; Disease; Down Syndrome; Environment; Exhibits; Gene Expression; Gene Expression Profile; Generations; Genes; Genetic; Genetic Transcription; Hippocampus (Brain); Homeostasis; Human; Human Chromosomes; IFNAR1 gene; Immune; Impairment; In Vitro; Individual; Intellectual functioning disability; Interferons; Learning; Link; Maintenance; Memory; Microglia; Mind; Modeling; Molecular; Mus; Neurons; Organoids; Orthologous Gene; Pathogenesis; Pathogenicity; Pathologic; Pathology; Patients; Performance; Phenotype; Plant Roots; Play; Property; Regulation; Research; Rodent; Role; Specific qualifier value; Synapses; Synaptic plasticity; System; Technology; Testing; Tissues; Transgenic Mice; Trisomy; base; brain abnormalities; brain cell; brain tissue; cell type; developmental disease; disease phenotype; dosage; improved; in vitro Model; in vivo; induced pluripotent stem cell; induced pluripotent stem cell technology; insight; macrophage; memory process; mouse model; nerve stem cell; neural circuit; neural network; new therapeutic target; novel; novel therapeutics; response; single-cell RNA sequencing; stem cells; synaptic function; synaptic pruning; tool; transcriptome

Down syndrome (DS), caused by triplication of human chromosome 21 (HSA21), is the most common genetic origin of intellectual disability. Studying DS disease mechanism is challenging because functional human DS brain tissues are scarcely available and transgenic mouse models of DS demonstrate incomplete/inaccurate expression of HSA21 genes. The advent of human induced pluripotent stem cell (hiPSC) technology has led to the generation of DS patient-derived hiPSCs, which presents an unprecedented opportunity for studying the pathogenesis of DS with unlimited human brain cells in vitro. While using the hiPSC-based in vitro models, basic aspects of the disease phenotypes can be examined, the disruption of neural circuits in the developing brain under disease conditions remains to be studied with hiPSCs. Ultimately, specific developmental and disease mechanisms can only be modeled in live animals to identify links between cellular phenotypes and behavioral performance. Therefore, we propose to employ hiPSC-based chimeric mouse brain models to study the neuropathophysiology of DS in vivo. Microglia play critical roles in brain development and are also an active player in learning and memory processes. Surprisingly, very little information is available on how trisomy of HSA21 alters the development and functions of microglia and what roles microglia play in the abnormal brain development and cognitive deficits in DS. In addition, mounting evidence indicates that rodent microglia are not able to fully mirror the properties of human microglia in normal and disease conditions. In this study, we will use our recently created hiPSC microglial chimeric mouse model to unravel the role of microglia in DS pathogenesis in an in vivo system with intact neural networks. We hypothesize that unlike engrafted normal human microglia, engrafted diseased DS human microglia will show abnormal biological properties and functions, such as synaptic pruning function in vivo. These abnormal properties of DS microglia will result in their negative regulation of the synaptic activity and plasticity of the hippocampal neural network, critically contributing to the cognitive deficits seen in DS. This hypothesis will be tested in three specific aims. Aim 1: we will determine the differences between DS and control hiPSC-derived microglia in vivo in human microglial chimeric mouse brains. Aim 2: Using the microglial chimeric mouse model, we will further examine the impact of integration of DS microglia on synaptic plasticity of the hippocampus and learning and memory behavior of the animals. Aim 3: We will normalize the expression of the HSA21 genes by CRISPR/Cas9 to examine how this will alter the properties of DS microglia. Moreover, single-cell RNA-sequencing analysis of hiPSC microglial chimeric mouse brains will be performed to compare gene expression profiles of control and DS microglia. Findings from our study using a powerful, new hiPSC microglial chimeric mouse model will provide novel insights into the pathological roles of human microglia in DS. Identifying the potential molecules that can be targeted to improve microglial function may provide a new therapeutic avenue for the treatment of DS.

唐氏综合症（DS）是由人类染色体21（HSA21）的一式三次引起的，是最常见的遗传 智力残疾的起源。研究DS疾病机制是具有挑战性的，因为功能性人类DS 脑组织几乎无法使用，DS的转基因小鼠模型表现出不完整/不准确 HSA21基因的表达。人类诱导的多能干细胞（HIPSC）技术的出现导致 DS患者衍生的HIPSC的产生为研究提供了前所未有的机会 在体外，具有无限的人脑细胞的DS发病机理。在使用基于HIPSC的体外模型时，基本 可以检查疾病表型的各个方面，在发育中的大脑中神经回路的破坏 在疾病状态下，hipscs仍有待研究。最终，特定的发育和疾病 机制只能在活动物中建模，以识别细胞表型与行为之间的联系 表现。因此，我们建议采用基于HIPSC的嵌合小鼠脑模型来研究 DS体内DS的神经病理生理学。小胶质细胞在大脑发育中起关键作用，也是一种活跃的 学习和记忆过程中的玩家。令人惊讶的是，几乎没有关于如何三体的信息 HSA21改变小胶质细胞的发育和功能以及小胶质细胞在异常大脑中起什么作用 DS中的发展和认知缺陷。此外，安装证据表明啮齿动物小胶质细胞不是 能够完全反映正常和疾病条件下人类小胶质细胞的特性。在这项研究中，我们将使用 我们最近创建的HIPSC小胶质细胞嵌合小鼠模型，以揭示小胶质细胞在DS发病机理中的作用 在具有完整神经网络的体内系统中。我们假设与植入正常的人类小胶质细胞不同， 植入患病的DS人类小胶质细胞将显示出异常的生物学特性和功能，例如突触 在体内修剪功能。 DS小胶质细胞的这些异常特性将导致其对 海马神经网络的突触活动和可塑性，严重导致认知缺陷 在DS中看到。该假设将以三个特定目的进行检验。目标1：我们将确定 DS和对照hipsc衍生的小胶质细胞体内人体小胶质细胞小鼠大脑中的体内。目标2：使用 小胶质嵌合小鼠模型，我们将进一步研究DS小胶质细胞整合对突触的影响 海马的可塑性以及动物的学习和记忆行为。目标3：我们将标准化 CRISPR/CAS9表达HSA21基因，以检查如何改变DS小胶质细胞的特性。 此外，将对HIPSC小胶质嵌合小鼠大脑进行单细胞RNA测序分析 比较对照和DS小胶质细胞的基因表达谱。我们研究的发现使用了一个强大的新型 HIPSC小胶质细胞嵌合小鼠模型将为人类小胶质细胞的病理作用提供新的见解 在DS中。确定可以针对改善小胶质功能的潜在分子可能会提供新的 治疗DS的治疗大道。