APOLIPOPROTEIN E IN NEUROBIOLOGY: CELLULAR MECHANISMS

神经生物学中的载脂蛋白 E：细胞机制

基本信息

批准号：
7431632
负责人：
ROBERT W. MAHLEY
金额：
$ 31.52万
依托单位：
J. DAVID GLADSTONE INSTITUTES
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-06-01 至 2008-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7431632
关键词：
3-hydroxy-3-methylglutaryl-coenzyme A 6-carboxyfluorescein Abbreviations Abeta clearance Affect Age of Onset Alleles Alzheimer&apos s Disease Amyloid Amyloid beta-Protein Amyloid beta-Protein Precursor Apolipoprotein E Apolipoproteins Arginine Binding Biology Brain California Cell Death Cell membrane Cell physiology Cells Cellular Membrane Cellular Neurobiology Cerebrospinal Fluid Characteristics Chemosensitization Cholesterol Coenzyme A Complex Condition Cyclin-Dependent Kinase 5 Cysteine Cytoskeleton Data Deposition Development Dimyristoylphosphatidylcholine Disease Disruption Eagles Edetic Acid Enzyme-Linked Immunosorbent Assay Extracellular Signal Regulated Kinases Extravasation Figs - dietary Fluorescein Fluorescein-5-isothiocyanate Fluoresceins Generations Glutamic Acid Glycogen Synthase Kinase 3 Goals Heparan Sulfate Proteoglycan High Density Lipoproteins Human In Vitro Inclusion Bodies Inorganic Sulfates Institutes Intracellular Membranes Isothiocyanates LDL-Receptor Related Protein 1 Lead Light Link Low-Density Lipoproteins Lysosomes Mediating Membrane Membrane Lipids Microtubules Mitogen-Activated Protein Kinases Molecular Molecular Weight Mus Nervous system structure Neuraxis Neurobiology Neurodegenerative Disorders Neurofibrillary Tangles Neuron-Specific Enolase Neurons Pathogenesis Pathway interactions Phosphate Buffer Physiological Pilot Projects Play Polyacrylamide Gel Electrophoresis Predisposition Process Production Property Protease Inhibitor Protein Isoforms Protein Overexpression Proteins RNA Interference Recycling Research Personnel Risk Factors Role Saline San Francisco Secondary to Sodium Structure Susceptibility Gene Transgenic Mice Transgenic Organisms Universities Unspecified or Sulfate Ion Sulfates Very low density lipoprotein age related apolipoprotein E-3 apolipoprotein E-4 base in vivo insight mutant neurofibrillary tangle formation neurofilament neuropathology novel therapeutics peptide A prevent programs receptor repaired tau Proteins tau aggregation tau phosphorylation tau-1 therapeutic target

项目摘要

Apolipoprotein (apo) E4 has been identified as a major risk factor or susceptibility gene for the development of Alzheimer's disease and other neurodegenerative disorders. Several hypotheses have been advanced to explain this association, including its role in altering amyloid beta (Abeta) peptide clearance and/or deposition (plaque formation), altering tau phosphorylation and microtubule biology (tangle formation), and altering cytoskeletal structure and function (remodeling and repair). Thus, apoE3 and apoE4 may impact neurobiology and neuropathology through multiple processes or pathways. In fact, it is reasonable to speculate that under various physiological or pathological conditions apoE may play different roles, some of which undoubtedly remain to be elucidated. Recent preliminary studies have extended our understanding of isoform-specific effects of apoE on neurons and may shed light on additional unique roles for apoE in neurobiology. First, apoE4 stimulates Abeta production in neuronal cells to a greater extent than apoE3 and the enhanced Abeta production is associated with increased amyloid precursor protein recycling. Sccond, apoE4 potentiates Abeta-induced lysosomal leakage and cell death whereas apoE3 does not. Third, apoE4 undergoes proteolytic cleavage to form intracellular carboxyl-terminal-truncated forms of apoE that induce neurofibrillary tangle-like inclusion formation in neurons (apoE4 > apoE3). Transgenic apoE4 mice expressing apoE in neurons have increased levels of tangle-like structures and phosphorylated tau inclusion bodies in neurons. The goal of this project is to investigate the mechanisms whereby apoE3 versus apoE4 alters these cellular pathways, including the apoE isoform-specific effects on Abeta production (Aim 1), Abeta-induced lysosomal leakage (Aim 2), and the formation of neurofibrillary tangle-like inclusions in neurons associated with the generation of bioactive intracellular proteolytic fragments of apoE (Aim 3). We will determine how these cellular pathways are modulated by the unique structural (conformational) characteristics of apoE, including domain interaction, in which the amino- and carboxyl-terminal domains interact only in apoE4 (arginine-61 reacting with glutamic acid-255) and molecular instability, in which apoE4 more readily forms reactive folding intermediates than apoE3. These studies, involving both in vitro and in vivo approaches, will provide additional insights into the role of apoE4 and may identify new therapeutic targets for apoE4-associated neuropathological disorders.

载脂蛋白 (apo) E4 已被确定为阿尔茨海默病和其他神经退行性疾病发展的主要危险因素或易感基因。已经提出了几种假设来解释这种关联，包括其在改变淀粉样蛋白 β (Abeta) 肽清除和/或沉积（斑块形成）、改变 tau 磷酸化和微管生物学（缠结形成）以及改变细胞骨架结构和功能（重塑）中的作用和修复）。因此，apoE3和apoE4可能通过多个过程或途径影响神经生物学和神经病理学。事实上，有理由推测，在不同的生理或病理条件下，apoE可能发挥不同的作用，其中一些无疑还有待阐明。最近的初步研究扩展了我们对 apoE 对神经元异构体特异性影响的理解，并可能揭示 apoE 在神经生物学中的其他独特作用。首先，apoE4 比 apoE3 更大程度地刺激神经元细胞中 Abeta 的产生，并且 Abeta 产生的增强与淀粉样前体蛋白回收的增加有关。其次，apoE4 增强 Abeta 诱导的溶酶体渗漏和细胞死亡，而 apoE3 则不然。第三，apoE4 经历蛋白水解裂解，形成细胞内羧基末端截短形式的 apoE，从而诱导神经元中神经原纤维缠结样包涵体的形成 (apoE4 > apoE3)。在神经元中表达 apoE 的转基因 apoE4 小鼠的神经元中缠结状结构和磷酸化 tau 包涵体的水平增加。该项目的目标是研究 apoE3 与 apoE4 改变这些细胞通路的机制，包括 apoE 异构体对 Abeta 产生的特异性影响（目标 1）、Abeta 诱导的溶酶体渗漏（目标 2）以及神经原纤维缠结的形成神经元中的类内含物与 apoE 的生物活性细胞内蛋白水解片段的生成相关（目标 3）。我们将确定这些细胞途径是如何的受 apoE 独特的结构（构象）特征调节，包括结构域相互作用，其中氨基和羧基端结构域仅在 apoE4 中相互作用（精氨酸 61 与谷氨酸 255 反应）和分子不稳定性，其中 apoE4 更容易形成比 apoE3 更活泼的折叠中间体。这些涉及体外和体内方法的研究将为apoE4的作用提供更多见解，并可能确定apoE4相关神经病理性疾病的新治疗靶点。