Mechanisms of cerebrovascular barrier dysfunction caused by APP and PSEN1 mutations and amyloid beta exposure

项目摘要 阿尔茨海默病(AD)的病因被认为包括与年龄相关的多种变化 大脑、遗传因素(风险和决定基因)以及环境和生活方式因素(如饮食、锻炼、 睡眠)。大脑中与年龄相关的变化包括萎缩、炎症、产生活性氧物种、 和血管功能障碍。AD研究中的一个中心问题是血管功能障碍(特别是在 大脑中的小血管)是AD病因的主要原因(血管假说)或次要原因 其他过程的结果(例如，淀粉样级联假说)。对人类和转基因小鼠的研究 已经确定血脑屏障(BBB)功能障碍可能在淀粉样β蛋白沉积之前发生， 大脑淀粉样血管病(CAA)和认知障碍的发病。人们认为阿尔茨海默病的发病 在出现记忆力丧失和认知缺陷等症状之前20年或更长时间。虽然此窗口提供了 在为干预提供机会的同时，它也给揭示疾病的根本原因带来了挑战。 确定血脑屏障功能障碍的机制对于了解疾病的进展和确定 干预的目标。 这项补充计划的目的是确定在一年内发生血脑屏障功能障碍的机制 APP和PSEN1突变及淀粉样β蛋白(Aβ)诱导的组织工程化脑小动脉模型 曝光。这一目标将通过两个目标来实现。在AIM 1中脑微血管内皮细胞 (IBMECs)和平滑肌细胞(ISMC)从含有 PSEN1(M146V)或APP(SWE)突变，以及野生型对照，将被整合到大脑特定的 本实验室建立的小动脉模型。从差异基因表达谱的分析 IBMEC和iSMC，AD突变改变的生物通路和可能的β暴露 脑血管功能障碍将被确认。在目标2中，将使用选定的功能分析文库来 确定脑血管功能障碍的突变依赖和淀粉样β依赖机制。 功能测量将包括与屏障功能相关的核心分析以及分析 根据目标1中确定的路径开发。这种混合方法将使我们能够专注于 最有可能因突变状态和Aβ暴露而改变的脑血管功能。

Project Summary The causes of Alzheimer’s disease (AD) are thought to include a combination of age-related changes in the brain, genetic factors (risk and deterministic genes), and environmental and lifestyle factors (e.g. diet, exercise, sleep). Age-related changes in the brain include atrophy, inflammation, generation of reactive oxygen species, and vascular dysfunction. A central question in AD research is whether vascular dysfunction (specifically in small vessels in the brain) is a primary cause of AD etiologies (vascular hypothesis) or a secondary consequence of other processes (e.g. amyloid cascade hypothesis). Studies in humans and transgenic mice have established that blood-brain barrier (BBB) dysfunction can occur prior to amyloid beta deposition, cerebral amyloid angiopathy (CAA), and the onset of cognitive impairment. The onset of AD is thought to occur 20 years or more before symptoms such as memory loss and cognitive deficits. While this window provides opportunities for intervention, it also poses challenges in uncovering the underlying causes of the disease. Identifying the mechanisms of BBB dysfunction is crucial to understanding disease progression and identifying targets for intervention. The objective of this supplement project is to identify the mechanisms of BBB dysfunction occurring within a tissue-engineered brain arteriole model caused by APP and PSEN1 mutations, and by amyloid beta (Aβ) exposure. The objective will be addressed in two aims. In Aim 1 brain microvascular endothelial cells (iBMECs) and smooth muscle cells (iSMCs) differentiated from an isogenic panel of iPSCs harboring PSEN1(M146V) or APP(Swe) mutations, along with wild type controls, will be incorporated into a brain-specific arteriole model developed in our laboratory. From analysis of the differential gene expression profiles of iBMECs and iSMCs, biological pathways altered by AD mutations and Aβ exposure that may underlie cerebrovascular dysfunction will be identified. In Aim 2 a selected library of functional assays will be used to determine mutation-dependent and amyloid beta-dependent mechanisms of cerebrovascular dysfunction. Functional measurements will include a core assays associated with barrier function, as well as assays developed based on pathways identified in Aim 1. This hybrid approach will enable us to focus on cerebrovascular functions that are most likely to be altered by mutational status and Aβ exposure.