iPSC-derived Neurovascular Organoids

简要说明 稳健的模型系统对于理解人类疾病至关重要。虽然可以使用近年来变得更具代表性的体内模型（例如通过将天然遗传多样性和人源化APOE变体引入现有的阿尔茨海默病小鼠模型）来研究阿尔茨海默病，但研究血管对认知障碍和痴呆（VCID）和脑小血管病（SVD）的贡献的能力仍然很困难。事实上，VCID和SVD的分子机制仍然是未知的，缺乏这些疾病的体内模型。因此，一个代表性的人类体外模型将有利于补充体内系统，并提高对血管对神经退行性变的贡献的理解。人类诱导多能干细胞（iPSC）技术的发展增加了体外中枢神经系统（CNS）模型的实用性，其已逐渐从分离的二维细胞培养物发展到更好地概括特定脑区域的组织和架构的多细胞三维组装体。然而，这些人类“大脑类器官”仍然存在严重缺陷。值得注意的是，皮质类器官表现出组织不当的层状结构，缺乏具有血脑屏障（BBB）功能的可灌注微血管系统。这些缺陷限制了使用脑类器官来理解VCID和SVD机制的代表性。在这个项目中，我们将开发一个具有强大神经血管功能的仿生脑类器官平台。本提案的目标1将描述皮质的组织和成熟。在一种新型生物材料中生长的类器官，模仿放射状神经胶质提供的线索，以帮助引导层状图案。目标2将专注于将脑内皮细胞和周细胞与皮质类器官整合，以在整个组织构建中开发可灌注的微血管系统，从而生成“神经血管类器官”平台。然后，目标3将通过使神经血管类器官经受已知会损害BBB的急性和慢性损伤来验证它们的代表性;特别是，具有定义的APOE基因型的iPSC将用于评估神经血管功能障碍的发作和进展，以响应这种公认的遗传风险因素。总的来说，本项目将建立一个人血管化皮质的体外模型，该模型有望用于阐明VCID和SVD的机制。

Summary statement Robust model systems are essential for understanding human disease. While Alzheimer’s disease can be studied using in vivo models that have become more representative in recent years (e.g. by introducing natural genetic diversity and humanized APOE variants into existing Alzheimer’s mouse models), the ability to study vascular contributions to cognitive impairment and dementia (VCID) and cerebral small vessel disease (SVD) remains difficult. Indeed, the molecular mechanisms underlying VCID and SVD remain mostly unknown, and in vivo models for these diseases are lacking. A representative human in vitro model would therefore be beneficial to complement in vivo systems and improve understanding of vascular contributions to neurodegeneration. The development of human induced pluripotent stem cell (iPSC) technology has increased the utility of in vitro central nervous system (CNS) models, which have gradually progressed from isolated two-dimensional cell cultures to multi-cellular three-dimensional assemblies that better recapitulate the organization and architecture of specific brain regions. However, these human ‘brain organoids’ still have significant deficits. Notably, cortical organoids exhibit improperly organized laminar architectures and lack perfusable microvasculature with blood-brain barrier (BBB) function. These deficits limit the representativeness of using brain organoids to understand the mechanisms of VCID and SVD. In this proposed project, we will develop a biomimetic brain organoid platform with robust neurovascular function. Aim 1 of this proposal will characterize the organization and maturation of cortica. organoids grown in a novel biomaterial that mimics cues provided by radial glia to help guide laminar patterning. Aim 2 will focus on integrating brain endothelial cells and pericytes with the cortical organoids to develop perfusable microvasculature throughout the tissue construct, thereby generating the ‘neurovascular organoid’ platform. Aim 3 will then validate the representativeness of the neurovascular organoids by subjecting them to acute and chronic injuries known to damage the BBB; in particular, iPSCs with defined APOE genotype will be used to assess onset and progression of neurovascular dysfunction in response to this well-established genetic risk factor. Overall, this project will establish a human in vitro model of the vascularized cortex that is expected to have utility for unraveling the mechanisms of VCID and SVD.