Targeting cerebrovascular endothelial cells as a therapeutic approach for amyloid pathogenesis

靶向脑血管内皮细胞作为淀粉样蛋白发病机制的治疗方法 项目摘要 淀粉样蛋白（Aβ）在脑血管中的积聚可导致脑血管病的发生 淀粉样血管病（CAA）。CAA是阿尔茨海默病（Alzheimer's disease，AD）的一种病理特征 高频率，突出了血管Aβ在痴呆症如AD中的潜在重要作用。而 Aβ介导对血脑屏障（BBB）的有害作用的基础可能是多因素的， 许多研究表明Aβ介导的内皮细胞通透性增加的作用。的确切原因 对于CAA中BBB功能障碍的影响尚不清楚，然而，Aβ从大脑中穿过大脑的清除受损， BBB以及减少血管周围引流的疗效已经提出，以提高 老年人脑血管和实质淀粉样沉积物的积累。尽管我们知道 负责BBB功能障碍和Aβ清除的途径，治疗Aβ的药物的可用性 发病机制相关的疾病，CAA和AD，仍然缺乏。该项目的长期目标是开发 靶向BBB以恢复其功能并最大限度地清除脑中的Aβ的治疗方法， 重要的是预防或延迟CAA和AD的发作。该项目的总体目标是充分表征 实验内皮血脑屏障模型作为一种有效的高通量筛选（HTS）格式，以确定 血管性Aβ发病机制障碍（AD、CAA和血管性痴呆）的治疗剂。核心假设 利用高度新颖的脑血管内皮BBB模型的高通量筛选（HTS）可以 用于鉴定有益地调节A β清除和减少A β介导的增加的小分子。 血脑屏障通透性我们将通过追求以下具体目标来检验这一假设：1）细胞的利用率 线为基础的BBB模型，以筛选调节剂的A β介导的干扰内皮细胞功能。这 目的将通过研究以下子目的来实现：1A）在存在下筛选化合物， A142寡聚体，用于使用Lucifer对脑血管内皮细胞的总渗透性的影响 黄色（LY）作为总渗透性标记。将使用降低A β介导的渗透性的化合物。 推进到子目标1B; 1B）使用金纳米颗粒识别穿过BBB模型的A β清除的刺激物。 碘化A β的标准测量作为A β清除的终点。命中化合物将进一步研究， 目标2. 2)来自Aim 1的命中化合物的调节能力的验证和机制研究 紧密连接和A β清除蛋白的表达（运输和降解）。这一目标将是 通过测试以下子目标完成：2A）进行二次确认并建立 目标1中鉴定的命中，2B）用于改善A β 42寡聚体诱导的渗透性的命中动力学的比较 与子目标2A、2C相比，降低了原代脑血管内皮细胞的A β清除率） 通过选定的命中化合物改善BBB紧密性、完整性和A β清除率的机制研究 从2B。3)测试目标2中前2个命中在体内调节血管和实质A β的能力 在CAA小鼠模型中的累积和BBB完整性。方法和技术，以实现 上述目标包括体外细胞培养、高通量筛选、转运、渗透性和清除 研究、CAA动力学、从野生型小鼠脑中分离微血管以及CAA模型中的体内研究。 产生的数据将提供候选治疗分子，以在未来的临床研究中进行测试。

Targeting cerebrovascular endothelial cells as a therapeutic approach for amyloid pathogenesis Project Summary The accumulation of amyloid- (Aβ) in the brain blood vessels can result in the development of cerebral amyloid angiopathy (CAA). CAA is a pathological feature present concomitantly with Alzheimer’s disease (AD) at a high frequency, highlighting a potentially important role for vascular Aβ in dementias such as AD. While the basis by which Aβ mediates deleterious effect on the blood-brain barrier (BBB) is likely multifactorial, numerous studies indicate a role for Aβ mediated increases in endothelial cell permeability. The exact causes for BBB dysfunction in CAA are not well known, however impaired clearance of Aβ from the brain across the BBB as well as a reduction in the efficacy of the perivascular drainage of A have been proposed to enhance accumulation of cerebrovascular and parenchymal amyloid deposits in the elderly. Despite our understanding of the pathways responsible for BBB dysfunction and clearance of Aβ, the availability of drugs to treat Aβ pathogenesis related disorders, CAA and AD, remains lacking. The long-term goal of this project is to develop therapeutics that target the BBB to restore its function and maximize clearance of Aβ from the brain, which is important to prevent or delay onset of CAA and AD. The overall goal of this project is to fully characterize an experimental endothelial BBB model as an effective high-throughput screening (HTS) format to identify therapeutics for vascular Aβ pathogenesis disorders (AD, CAA and vascular dementia). The central hypothesis is that high-throughput screening (HTS) utilizing a highly novel cerebrovascular endothelial BBB model can be used to identify small molecules which beneficially regulate A clearance and reduce A mediated increases in BBB permeability. We will test this hypothesis by pursuing the following specific aims: 1) Utilization of a cell line-based BBB model to screen for modulators of A mediated disturbances of endothelial cell function. This aim will be accomplished by investigating the following sub-aims: 1A) screen for compounds, in the presence of A42 oligomers, for their effect on the gross permeability of cerebrovascular endothelial cells using Lucifer Yellow (LY) as a gross permeability marker. Compounds which reduce A-mediated permeability will be advanced to Sub-Aim 1B; 1B) identify stimulators of A clearance across the BBB model using the gold standard measure of iodinated A as the endpoint for A clearance. Hit compounds will be further examined in Aim 2. 2) Validation and mechanistic investigation of hit compounds from Aim1 for their ability to modulate expression of tight junction and A clearance proteins (transport and degradation). This aim will be accomplished by testing the following sub-aims: 2A) conduct secondary confirmation and establish profiles for hits identified in Aim 1, 2B) comparison of hits kinetics for amelioration of A42 oligomers induced permeability and reduced A clearance in primary cerebrovascular endothelial cells with those of Sub-Aim 2A, 2C) mechanistic investigation for improved BBB tightness, integrity and A clearance by hit compounds selected from 2B. 3) Test ability of the top 2 hits from Aim 2 to in vivo modulate vascular and parenchymal A accumulation, and BBB integrity in a mouse model of CAA. Methods and technique to be used to accomplish the above aims include in vitro cell culture, high-throughput screening, transport, permeability and clearance studies, A kinetics, microvessels isolation from brains of wild type mice, and in vivo studies in CAA model. The data produced will provide candidate therapeutic molecules to test in future clinical studies.