Role of ApoE4 Domain Interaction in Neurodegeneration

描述（申请人提供）：载脂蛋白（apo）E4是一种 神经退行性疾病（包括阿尔茨海默氏症）的既定风险因素 疾病（AD），以及头部创伤和中风的不良结局。但 这种风险增加的潜在机制仍然难以捉摸。由于蛋白质 功能与蛋白质结构直接相关，我们重点关注 确定区分apoE同种型的结构特征，以获得 深入了解这些差异如何与不同的机制 同种型在神经变性中的作用。我们的结构和突变 研究证实apoE含有两个结构域。在apoE 4中，但是 而不是apoE 3和apoE 2，这两个结构域相互作用。我们的假设是 apoE 4的这种独特的结构特性对其 功能特性，包括脂质转运，代谢和机制， apoE 4会导致神经退化和心脏病目标在 本应用程序旨在测试这一假设的背景下， 使用体外模型系统和新型apoE小鼠的神经变性和AD 模型，其中结构域相互作用被基因工程化到小鼠apoE中 靶向（Arg-6 1小鼠apoE）。在具体目标1中，我们将检验假设 该结构域相互作用决定了Arg-6 1的脂质结合特性， 小鼠apoE和人apoE 4。在具体目标2中，我们将检验以下假设： Arg-61小鼠apoE中的结构域相互作用影响 由培养的原代星形胶质细胞分泌的脂蛋白颗粒。具体目标 3、我们将检验Arg-61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生长。具体目标 4、我们将检验Arg-6 1小鼠apoE 4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表明， 可能为apoE 4的作用机制提供线索， 神经退行性变，并根据亚型特异性 方面的影响.

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.