Role of ApoE4 Domain Interaction in Neurodegeneration

描述(申请人提供)：载脂蛋白(Apo)E4是一种 公认的神经退行性疾病的危险因素，包括阿尔茨海默氏症 疾病(AD)，以及头部创伤和中风的不良结局。然而， 这种风险增加背后的机制仍然难以捉摸。因为蛋白质 功能直接关系到蛋白质的结构，一直是我们关注的重点 确定区分载脂蛋白E亚型的结构特征以获得 洞察这些差异如何与不同的 亚型在神经退行性变中的作用。我们的结构和突变 研究证实，apoE含有两个结构域。在apoE4中，但是 这两个结构域相互作用，而不是apoE3和APOE2。我们的工作假设是 ApoE4的这种独特的结构特性对其 功能特性，包括脂类的运输、代谢和作用机制 哪种载脂蛋白E4与神经退行性变和心脏病有关。中国的目标 此应用程序旨在测试以下上下文中的假设 利用体外模型系统和一种新的apoE小鼠建立神经退行性变和AD 通过基因工程将结构域相互作用引入小鼠载脂蛋白E的模型 靶向(Arg-61小鼠载脂蛋白E)。在具体目标1中，我们将检验假设 结构域相互作用决定了Arg-6 1的脂质结合特性 小鼠载脂蛋白E和人载脂蛋白E4。在具体目标2中，我们将检验假设 Arg-61小鼠apoE中结构域相互作用影响ApoE的类型和组成 培养的原代星形胶质细胞分泌的脂蛋白颗粒。以特定的目标 3，我们将检验Arg-6 1小鼠apoE中结构域相互作用的假设 减少细胞和器官培养系统中的神经元突起。以特定的目标 4，我们将检验Arg-6 1小鼠apoE4中结构域相互作用的假设 会导致神经退化。这些研究的结果具有 有可能为载脂蛋白E4参与的机制提供线索 神经退行性变和基于异构体特异性的治疗靶点的确定 效果。

DESCRIPTION (provided by the applicant): Apolipoprotein (apo) E4 is an established risk factor for neurodegenerative disease, including Alzheimer's disease (AD), and for poor outcome from head trauma and stroke. However, the mechanism underlying this increased risk remains elusive. Since protein function is directly related to protein structure, we have focused on determining the structural features that distinguish the apoE isoforms to gain insight into how these differences relate to the mechanism for the different effects of the isoforms in neurodegeneration. Our structural and mutagenesis studies established that apoE contains two structural domains. In apoE4, but not apoE3 and apoE2, the two domains interact. Our working hypothesis is that this unique structural property of apoE4 has a major influence on its functional properties, including lipid transport, metabolism, and mechanisms by which apoE4 contributes to neurodegeneration and heart disease. The aims in this application are designed to test this hypothesis in the context of neurodegeneration and AD using in vitro model systems and a novel apoE mouse model, in which domain interaction was engineered into mouse apoE in by gene targeting (Arg-6 1 mouse apoE). In Specific Aim 1, we will test the hypothesis that domain interaction determines the lipid-binding properties of Arg-6 1 mouse apoE and human apoE4. In Specific Aim 2, we will test the hypothesis that domain interaction in Arg-61 mouse apoE influences the type and composition of lipoprotein particles secreted by cultured primary astrocytes. In Specific Aim 3, we will test the hypothesis that domain interaction in Arg-6 1 mouse apoE decreases neuronal outgrowth in cell and organ culture systems. In Specific Aim 4, we will test the hypothesis that domain interaction in Arg-6 1 mouse apoE4 contributes to neurodegeneration. The results from these studies have the potential to provide clues into the mechanism by which apoE4 contributes to neurodegeneration and to identify therapeutic targets based on isoform-specific effects.