Is There a Link Between Alzheimer's and Atherosclerosis

描述（由申请人提供）：阿尔茨海默病（AD）是一种神经退行性疾病，影响超过400万美国人。我们是第一个证明脑血管在阿尔茨海默病中释放神经毒性蛋白的人。然而，导致这种血管功能障碍的因素尚不清楚。我们的假设是，动脉粥样硬化发病机制中的危险因素也与阿尔茨海默病中血管介导的神经元细胞死亡的发展有因果关系。我们的研究是及时和重要的，因为越来越多的证据表明动脉粥样硬化和阿尔茨海默病之间的联系。目标1：确定全身氧化应激或高脂血症对血管凝血酶释放、血管介导的神经毒性和apoE转基因小鼠认知能力的影响。从表达人E3或E4的apoE敲除或转基因小鼠分离的脑血管用于评估apoE同种型对凝血酶血管表达的作用。饮食诱导的高同型半胱氨酸血症和高脂血症分别用于评估氧化应激和脂质对血管凝血酶释放和血管介导的神经毒性的作用。此外，这些转基因小鼠用于评估氧化剂和脂质应激对学习和记忆障碍的可能apoE亚型特异性影响。目标二：确定参与动脉粥样硬化发病机制的危险因素是否也与阿尔茨海默病中血管介导的神经元细胞死亡的发生有因果关系。从AD患者和非痴呆患者中分离脑微血管，并分析凝血酶和其他可能的神经毒性蛋白质（包括基质金属蛋白酶（MMP）、炎性细胞因子和趋化因子以及内皮素-1）的水平和/或活性。通过ELISA和Western印迹测定蛋白质水平，通过北方印迹和RT-PCR评估mRNA水平。通过比较从不同APOE基因型患者中分离的微血管来确定apoE亚型在调节这些蛋白质中的作用。在体外添加氧或脂质分子到分离的脑微血管中用于评估氧化应激和脂质分别对凝血酶、MMP、炎性蛋白和内皮素-1释放的影响。在暴露于这些蛋白质的培养的神经元细胞中测量细胞凋亡和坏死。 这些结果将首次确定将心血管风险因素与阿尔茨海默病中血管介导的神经元细胞死亡联系起来的机制级联，并确定治疗干预的新靶点。

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.