Regulation of microglia by tissue stiffness and Piezo1 in Alzheimer's disease

项目摘要/摘要 阿尔茨海默病(AD)的标志性病理指标之一是 淀粉样斑块或淀粉样β蛋白致密灶部位的小胶质细胞。小胶质细胞是主要的 脑内固有免疫细胞，通过以下途径在脑内稳态中发挥重要作用 突触修剪，健康的淀粉样β转换，以及推进和消退炎症 回应。这些细胞与几乎所有的神经退行性疾病有关，而且 因此，了解他们的微环境如何影响健康和病理功能 非常重要。这个探索性项目的目标是研究组织的潜在作用。 在AD的调节中，僵硬通过淀粉样斑块的沉积而改变 小胶质细胞功能。研究人员之前的工作表明，僵硬调节了 单核细胞来源的巨噬细胞的功能，这是一种密切相关的先天免疫细胞。更僵硬 底物促进细胞因子的产生，以响应炎性刺激，如内毒素 通过机械敏感的钙离子通道Piezo1。在此，我们建议 利用人干细胞研究刚性和Piezo1在小胶质细胞功能中的作用 Piezo1基因缺失的小胶质细胞和嵌合动物模型。在目标1中，我们将使用 工程培养基板，以研究刚性对Piezo1活性的影响，以及 下游对小胶质细胞炎症、迁移和吞噬行为的影响。在目标2中，我们 将细胞移植到人源化AD小鼠中研究小胶质细胞植入，与 斑块，以及体内的炎症。总之，这些研究将调查一个新的角色 僵硬和Piezo1在AD进展过程中的小胶质细胞功能。

PROJECT SUMMARY / ABSTRACT One of the hallmark pathological indicators of Alzheimer’s disease (AD) is the accumulation of microglia at sites of amyloid plaques or dense foci of amyloid beta. Microglia are the primary resident innate immune cells of the brain and play a major role in brain homeostasis through synaptic pruning, healthy amyloid beta turnover, and advancing and resolving inflammatory responses. These cells have been implicated in almost all neurodegenerative diseases, and thus understanding how their microenvironment influences healthy and pathological function is critically important. The goal of this exploratory project is to examine the potential role of tissue stiffness, which is altered by the deposition of amyloid plaques during AD, in regulation of microglia function. Previous work from the investigator has shown that stiffness modulates the function of monocyte-derived macrophages, a closely related innate immune cell. Stiffer substrates enhance the production of cytokines in response to inflammatory stimuli such as LPS through the mechanosensitive calcium permeable ion channel Piezo1. Here, we propose to study the role of stiffness and Piezo1 in microglia function using human stem cell-derived microglia with Piezo1 genetically depleted and a chimeric animal model. In Aim 1, we will use engineered culture substrates to investigate the effects of stiffness on Piezo1 activity, and downstream effects on microglia inflammatory, migratory, and phagocytic behavior. In Aim 2, we will transplant cells into humanized AD mouse to study microglia engraftment, association with plaques, and inflammation in vivo. Together, these studies will investigate a novel role for stiffness and Piezo1 in microglia function during AD progression.