EXCITATORY AMINO ACID RECEPTOR GENES AND PROTEINS IN AD

AD 中的兴奋性氨基酸受体基因和蛋白质

• 批准号: 6234435
• 负责人: ANNE B YOUNG
• 金额: $ 14.55万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-15 至 1998-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6234435
• 关键词: Alzheimer's disease; NMDA receptors; RNase protection assay; aging; amine oxidoreductase; amyloid proteins; autoradiography; calmodulin dependent protein kinase; cell cycle proteins; cytochrome oxidase; excitatory aminoacid; gene expression; glutamate receptor; glycine; human tissue; immunocytochemistry; in situ hybridization; laboratory rat; neuroanatomy; phosphoprotein phosphatase; postmortem; receptor binding; receptor expression; receptor sensitivity

Excitatory amino acids (EAA) are the neurotransmitters of the majority of cortical and hippocampal excitatory pathways in mammalian brain and are the likely neurotransmitters of cortical and hippocampal pyramidal neurons. The pyramidal neurons of association cortex and hippocampus develop neurofibrillary tangles early in AD. Biochemical and anatomical studies of Ad brain show decreases in glutamate levels and EAA receptors. EAA have been hypothesized to play a role in AD because EAA agonists are excitotoxic and because the area most affected in AD have high concentrations of EAA and EAA receptors. Among the three EAA receptors linked to ion channels (the N-methyl-D-aspartate (NMDA), alpha-amino-3- hydroxy-5-methyl-4-isoxazole-4-propionic acid receptor (AMPA) and kainate receptors), the NMDA receptors are decreased to a greater extent than others. Two types of metabotropic EAA receptor exist, one linked to phosphoinositol metabolism which is variably decreased in AD brain and one linked to adenylate cyclase which is markedly decreased in AD. Not all cortical areas with high densities of these markers are affected in AD, however, and thus any role of EAA in the pathogenesis of AD must be secondary to their additional features of neuronal vulnerability. The regional hierarchy of cellular vulnerability to neurofibrillary degeneration has been defined in aging and AD. Furthermore, the genes for the various EAA receptor subtypes have been cloned and specific antibodies to most of them have been produced. It is thus possible to define the relationship of particular EAA receptor subtype genes and proteins to other potential markers of neurodegeneration in AD. In this project, receptor autoradiography, in situ hybridization and immunocytochemistry will be used to address two hypotheses concerning the role of EAA in aging and AD. The first hypothesis is that high densities of NMDA receptors, high densities of MGluR5 receptors and low densities of mGluR1 receptors are expressed in those neurons preferentially lost in aging and AD. The second hypothesis is that high densities of NMDA receptors are expressed in cells with high densities of MPA kinases and APP and APLP and low densities of NMDA receptors are expressed in nitric oxide synthase containing neurons. These studies will be carried out in close collaboration with projects 2,3, and 4 which will independently be examining related aspects of the potential metabolic and excitotoxic cascades involved in the cellular vulnerability of aging and AD. The project will also use the reagent core for tissue acquisition and analysis of EAA receptor proteins and genes by Western and Northern blot analysis.

兴奋性氨基酸（EAA）是多数的神经递质 哺乳动物大脑中的皮质和海马兴奋性途径 是皮质和海马锥体的可能的神经递质 神经元。 缔合皮质和海马的锥体神经元 在AD早期开发神经原纤维缠结。 生化和解剖学 AD脑的研究表明，谷氨酸水平和EAA受体的降低。 EAA已被认为在广告中发挥作用，因为EAA激动剂是 兴奋性毒性，因为广告中受影响最大的区域具有很高 EAA和EAA受体的浓度。 在三个EAA受体中 与离子通道（N-甲基-D-天冬氨酸（NMDA），alpha-Amino-3-相关联 羟基-5-甲基-4-异恶唑-4-丙酸受体（AMPA）和海藻酸盐 受体），NMDA受体的降低程度大于 其他的。 存在两种类型的代谢EAA受体，一种链接到 磷酸肌醇代谢，在AD脑中有多降低，并且 一种与腺苷酸环化酶相关的，AD在AD中显着降低。 不是 所有具有高密度标记的皮质区域都受到影响 但是，AD，因此EAA在AD发病机理中的任何作用都必须是 其次是其神经元脆弱性的其他特征。 这 细胞脆弱性神经纤维的区域层次结构 变性已在衰老和AD中定义。 此外，基因 对于各种EAA受体亚型已被克隆并具有特异性 它们的大多数抗体已经生产。 因此有可能 定义特定EAA受体亚型基因与 AD中神经变性的其他潜在标记的蛋白质。 在这个 项目，受体放射自显影，原位杂交和 免疫细胞化学将用于解决有关该化学的两个假设 EAA在衰老和广告中的作用。 第一个假设是高密度 NMDA受体，高密度的MGLUR5受体和低密度 MGLUR1受体的表达在那些神经元中优先丢失 在衰老和广告中。 第二个假设是NMDA的高密度 受体在高密度MPa激酶和 NMDA受体的APP和APLP和低密度以氮表示 含有神经元的氧化物合酶。 这些研究将在 与项目2,3和4的密切合作将独立合作 检查潜在的代谢和兴奋性毒性的相关方面 参与衰老和AD的细胞脆弱性的级联反应。 这 项目还将使用试剂核心进行组织采集和 通过西方和北印迹对EAA受体蛋白和基因分析 分析。