Is There a Link Between Alzheimer's and Atherosclerosis

阿尔茨海默病和动脉粥样硬化之间有联系吗

• 批准号: 6728922
• 负责人: PAULA GRAMMAS
• 金额: $ 32.3万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-01-15 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6728922
• 关键词: Alzheimer' s disease; apoenzymes; apolipoprotein E; atherosclerosis; blood lipid; blood vessel disorder; cell death; enzyme linked immunosorbent assay; genetically modified animals; human tissue; hypercholesterolemia; hyperlipidemia; laboratory mouse; microcirculation; neurotoxicology; northern blottings; oxidative stress; pathologic process; polymerase chain reaction; thrombin; western blottings

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is a neurodegenerative disease that affects over 4 million Americans. We are the first to demonstrate that brain blood vessels release neurotoxic proteins in Alzheimer's disease. However, the factors that cause this vessel dysfunction are not known. It is our hypothesis that risk factors involved in the pathogenesis of atherosclerosis are also causally linked to the development of vascular-mediated neuronal cell death in Alzheimer's disease. Our studies are timely and important as increasing evidence points to a link between atherosclerosis and Alzheimer's disease. Aim 1: To determine the effects of systemic oxidant stress or hyperlipidemia on vascular thrombin release, vascular-mediated neurotoxicity and on the cognitive performance of apoE transgenic mice. Brain blood vessels isolated from apoE knockout or transgenic mice expressing human E3 or E4 are used to assess the role of apoE isoforms on vascular expression of thrombin. Diet-induced hyperhomocystinemia and hyperlipidemia, are used to assess the role of oxidant stress and lipids, respectively, on vascular thrombin release and vascular-mediated neurotoxicity. Also, these transgenic mice are utilized to evaluate possible apoE isoform-specific effects of oxidant and lipid stress on impairments in learning and memory. Aim 2: To determine if risk factors involved in the pathogenesis of atherosclerosis are also causally linked to the development of vascular-mediated neuronal cell death in Alzheimer's disease. Brain microvessels are isolated from AD patients and non-demented patients and analyzed for levels and/or activity of thrombin and other possible neurotoxic proteins, including, matrix metalloproteinases (MMPs), inflammatory cytokines and chemokines, and endothelin-l. Protein levels are determined by ELISA and Western blots and Mrna levels assessed by Northern blots and RT-PCR. The role that apoE isoforms play in regulating these proteins is determined by comparing microvessels isolated from patients with different APOE genotypes. In vitro addition of oxygen species or lipid molecules to isolated brain microvessels is used to assess the effects of oxidative stress and lipids, respectively, on release of thrombin, MMPs, inflammatory proteins, and endothelin-l. Apoptosis and necrosis are measured in cultured neuronal cells exposed to these proteins. These results would, for the first time, identify a mechanistic cascade linking cardiovascular risk factors to vascular-mediated neuronal cell death in Alzheimer's disease and identify novel targets for therapeutic intervention.

描述（由申请人提供）：阿尔茨海默氏病（AD）是一种影响超过400万美国人的神经退行性疾病。我们是第一个证明脑血管在阿尔茨海默氏病中释放神经毒性蛋白的人。但是，尚不清楚引起该血管功能障碍的因素。我们的假设是，动脉粥样硬化发病机理涉及的危险因素也与阿尔茨海默氏病血管介导的神经元细胞死亡的发展有关。我们的研究及时而重要，因为越来越多的证据表明动脉粥样硬化与阿尔茨海默氏病之间的联系。目标1：确定全身氧化剂应激或高脂血症对血管凝血酶释放，血管介导的神经毒性以及APOE转基因小鼠的认知性能的影响。从APOE敲除或表达人E3或E4的转基因小鼠中分离出来的脑血管用于评估APOE同工型在凝血酶血管表达中的作用。饮食诱导的高血囊血症和高脂血症分别用于评估氧化应激和脂质在血管凝血酶释放和血管介导的神经毒性方面的作用。同样，这些转基因小鼠被用来评估氧化剂和脂质应激对学习和记忆中障碍的APOE同工型特异性作用。目的2：确定动脉粥样硬化发病机理涉及的危险因素是否也与阿尔茨海默氏病血管介导的神经元细胞死亡的发展有关。脑微血管是从AD患者和非痴呆患者中分离出来的，并分析了凝血酶和其他可能的神经毒性蛋白的水平和/或活性，包括基质金属蛋白酶（MMP），炎性细胞因子和趋化因子和趋化因子，以及内皮素-L。蛋白质水平由ELISA和Western印迹和通过Northern印迹和RT-PCR评估的mRNA水平确定。 APOE同工型在调节这些蛋白质中起的作用是通过比较从不同APOE基因型的患者中分离出的微血管来确定的。在体外添加氧或脂质分子与分离的脑微血管中分别用于评估氧化应激和脂质对凝血酶，MMP，MMP，炎性蛋白和内皮素-L释放的影响。在暴露于这些蛋白质的培养神经元细胞中测量凋亡和坏死。 这些结果将首次确定一个机械级联，将心血管危险因素与阿尔茨海默氏病的血管介导的神经元细胞死亡联系起来，并确定治疗干预的新颖靶标。