CHOROID PLEXUS AND A BETA/APOLIPOPROTEIN CNS HOMEOSTASIS

脉络丛和 β/载脂蛋白中枢神经系统稳态

• 批准号: 6318256
• 负责人: Berislav V Zlokovic
• 金额: $ 33.2万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-15 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6318256
• 关键词: Alzheimer's disease; amyloid proteins; apical membrane; apolipoproteins; basolateral membrane; blood lipoprotein transport; brain circulation; brain metabolism; cerebrospinal fluid; choroid plexus; endocytosis; guinea pigs; homeostasis; human tissue; postmortem; tissue /cell culture; transcytosis; vascular endothelium

Deposition of amyloid beta peptide (Abeta) in vascular CNS tissues and the choroid plexus (CP) occurs during normal aging and is accelerated by Alzheimer's disease (AD). Recent studies suggest major roles for the blood-brain barrier (BBB) and the cerebrospinal fluid (CSF) clearance in regulating the concentrations of Abeta in the CNS. The CP has important functions in regulating the levels of several proteins in the CSF and brain, and in cleansing the CSF of waste and potentially cytotoxic substances for brain. The role of CP in Abeta CNS homeostasis is largely unknown. Our preliminary in vivo data in guinea pigs indicate that glycoprotein 330 and possibly some other members of the low density lipoprotein receptor family participate in CP epithelial internalization of lipid-free Abeta/1-40 complexed to apolipoproteins (apo) J and E4, respectively. The CP uptake of blood-borne lipidated apoE3 and apoE4 was up to 4.5-fold greater compared to their respective dilapidated monomers. Circulating unbound free Abeta/1-40 is prevented from crossing the blood-CSF barrier, in contrast to its rapid transport out of the CSF, remarkable accumulation of CNS-derived Abeta by the CP epithelium and significant uptake by leptomeningeal vessels. Preliminary attempts to develop an in vitro transport model of the blood-CSF barrier constructed from cultured human CP epithelial cells confirmed asymmetrical Abeta transcytosis across human CP epithelium consistent with in vivo data. We propose to use in vivo vascular brain/CP and ventriculo-cisternal perfusions in guinea-pigs and an in vitro transport model of human blood-CSF barrier from control and AD subjects to test the hypothesis that the CP regulates Abeta CNS homeostasis by controlling transport in and out of the CSF and brain of lipid-free and lipid-bound apoJ and different apoE isoforms free and complexed to Abeta. We will determine in vivo basolateral CP uptake, metabolism and transport across the blood-CSF barrier of circulating apoJ, E2, E3 and E4, delipidated, lipidated, free and complexed to Abeta (aim 1), and their clearance from the CSF, uptake at the apical side of the CP and sequestration by leptomeningeal and parenchymal microvessels (aim 2). In aims 3 and 4 we will study the CP epithelial basolateral-to-apical and apical-to-basolateral Abeta/apolipoprotein binding, endocytosis and transcytosis using human in vitro model. The role of different lipoprotein and Abeta receptors will be defined. The studies will provide the molecular basis to understand the CP functions involved in the regulation of the CSF and CNS levels of Abeta to minimize its CNS accumulation and pathogenic effects.

淀粉样β肽（Abeta）在血管CNS组织中的沉积， 脉络丛（CP）在正常衰老期间发生， 阿尔茨海默病（AD）。最近的研究表明， 血脑屏障（BBB）和脑脊液（CSF）的清除率 调节中枢神经系统中Abeta的浓度。CP具有重要的 调节CSF中几种蛋白质的水平， 脑，并在清洗废物和潜在的细胞毒性CSF 大脑的物质。CP在Abeta中枢神经系统稳态中的作用很大程度上 未知我们在豚鼠体内的初步数据表明， 糖蛋白330以及可能的一些其他低密度成员 脂蛋白受体家族参与CP上皮内化 与载脂蛋白（apo）J和E4复合的无脂质Abeta/1-40， 分别脂化apoE 3和apoE 4的CP摄取是 与其各自的破旧房屋相比， 单体。阻止循环中未结合的游离Abeta/1-40穿过 血-CSF屏障，与其快速运输出 CSF，CP上皮细胞中CNS衍生的Abeta显著蓄积 并被软脑膜血管显著摄取。初步尝试 开发血-CSF屏障的体外转运模型 由培养的人CP上皮细胞构建， 在人CP上皮中的不对称Abeta转胞吞作用与 体内数据。我们建议使用体内血管脑/CP， 豚鼠脑室-脑池灌注和体外转运 来自对照和AD受试者的人血-CSF屏障模型进行测试 CP通过以下方式调节Abeta CNS稳态的假设 控制无脂质和无脂质药物在CSF和脑中的进出运输， 脂质结合的apoJ和不同的apoE同种型游离并复合到 Abeta我们将确定体内基底外侧CP的吸收、代谢和 循环apoJ、E2、E3和E4穿过血液-CSF屏障的转运 E4，脱脂、脂化、游离并与Abeta复合（目标1），和 它们从CSF中的清除率，CP顶侧的摄取， 软脑膜和实质微血管隔离（目的2）。在 目的3和4，我们将研究CP上皮基底外侧到顶端， 顶侧至基底侧A β/载脂蛋白结合、内吞和 使用人体外模型的胞吞转。不同的角色 将定义脂蛋白和Abeta受体。这些研究将 提供分子基础，以了解CP功能参与 调节CSF和CNS的Abeta水平，以最大限度地减少其CNS 积累和致病作用。