Stress Granules Cause Translation Arrest In Ischemic Vulunerable Neurons

应激颗粒导致缺血性易损神经元的翻译停滞

• 批准号: 7560410
• 负责人: DONALD J DEGRACIA
• 金额: $ 32.92万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7560410
• 关键词: Acute; Address; Antibiotics; Behavior; Biochemical; Blood; Blood flow; Brain; Brain Injuries; Brain Ischemia; Cause of Death; Cell Death; Cells; Cellular Stress; Cessation of life; Clinical; Cycloheximide; Cytoplasmic Granules; Data; Development; Employee Strikes; Exposure to; Foundations; Functional disorder; Goals; Heart Arrest; Hippocampus (Brain); Immunofluorescence Immunologic; Ischemia; Ischemic Brain Injury; Ischemic Preconditioning; Laboratories; Light; Mediating; Microscopic; Modality; Morbidity - disease rate; Neurons; Phase; Physicians; Protein Biosynthesis; Protein Synthesis Inhibition; Protein Synthesis Inhibitors; Proteins; Puromycin; Recovery; Reperfusion Injury; Reperfusion Therapy; Resistance; Resuscitation; Scientist; Stress; Stroke; Techniques; Translations; Work; base; cell injury; effective therapy; hippocampal pyramidal neuron; in vivo; injured; mortality; neuronal survival; novel therapeutics; particle; prevent

DESCRIPTION (provided by applicant): Ischemia and reperfusion (I/R) injury of the brain occurs following resuscitation from cardiac arrest and stroke, and results in high morbidity and mortality. There is no clinically effective treatment because of an incomplete understanding of the cellular injury cascades leading to cell death. The long- term goal of my laboratory is to investigate the mechanisms of neuronal death caused by brain I/R to allow for the development of effective treatments. There is a striking correlation between protein synthesis inhibition and the selective death of hippocampal CA1 pyramidal neurons following transient global brain I/R. The mechanism of this irreversible translation arrest and its relationship to cell death is unknown. Stress granules are cytoplasmic particles that sequester inactive translational machinery during cellular stress. We present compelling evidence that stress granule alterations are central to persistent translation arrest in ischemic-vulnerable hippocampal CA1 neurons. Our Specific Aims are: 1. To investigate the mechanism of irreversible translation arrest. We will analyze the functional composition of stress granules utilizing complementary microscopic and biochemical approaches. We will compare stress granules in ischemic resistant CA3 and ischemic vulnerable CA1 from early reperfusion to the point of cell death of vulnerable neurons. 2. To identify the effect of ischemic preconditioning (IPC) on stress granule composition and behavior in reperfused neurons. IPC prevents both cell death and persistent translation arrest in vulnerable CA1 neurons. We will assess the effect of IPC on stress granule behavior and composition, protein synthesis rates, and cell death in CA1 neurons. 3. To show that persistent translation arrest is causally related to neuronal death following brain I/R. Antibiotic protein synthesis inhibitors will be used to predictably alter stress granules in reperfused hippocampal neurons, and we will examine the effect on protein synthesis rates, stress granule composition and behavior and cell death in reperfused hippocampal neurons. By providing an integrated examination of the relationship between persistent translation arrest and I/R-induced cell death, our Specific Aims address a problem that has been a barrier to progress in the field: how irreversible inhibition of protein synthesis in reperfused neurons causes cell death. PUBLIC HEATH RELEVANCE: Every year, millions of people are injured or die from brain damage caused by cardiac arrest or stroke. There are no treatments to prevent this brain damage because physicians and scientists do not understand how the cells die following a period when blood has stopped flowing in the brain and subsequently resumed. The work in this proposal seeks to further our understanding of the way in which neurons in the brain die following a period of low or no blood flow (ischemia) followed by resumption of normal blood flow (reperfusion).

描述（由申请人提供）：脑缺血和再灌注（I/R）损伤发生在心脏骤停和中风复苏后，并导致高发病率和死亡率。由于对导致细胞死亡的细胞损伤级联的不完全理解，因此没有临床有效的治疗方法。我实验室的长期目标是研究脑I/R引起的神经元死亡的机制，以开发有效的治疗方法。短暂性全脑缺血再灌注后海马CA 1区锥体神经元的选择性死亡与蛋白质合成抑制有显著相关性。这种不可逆的翻译停滞的机制及其与细胞死亡的关系尚不清楚。应激颗粒是细胞质颗粒，在细胞应激期间隔离不活跃的翻译机器。我们提出了令人信服的证据表明，应力颗粒的改变是中央持续翻译逮捕缺血脆弱的海马CA 1区神经元。我们的具体目标是：1。探讨不可逆翻译停滞的机制。我们将利用互补的显微镜和生物化学方法分析应激颗粒的功能组成。我们将比较从早期再灌注到脆弱神经元细胞死亡的缺血抵抗性CA 3和缺血脆弱性CA 1中的应激颗粒。2.探讨缺血预处理（IPC）对再灌注神经元应激颗粒组成和行为的影响。IPC防止脆弱的CA 1神经元中的细胞死亡和持续的翻译停滞。我们将评估IPC对CA 1神经元中应激颗粒行为和组成、蛋白质合成速率和细胞死亡的影响。3.表明持续性翻译停滞与脑I/R后神经元死亡存在因果关系。抗生素蛋白合成抑制剂将用于可预测地改变再灌注海马神经元中的应激颗粒，并且我们将检查对再灌注海马神经元中的蛋白合成速率、应激颗粒组成和行为以及细胞死亡的影响。通过对持续性翻译停滞和I/R诱导的细胞死亡之间的关系进行综合研究，我们的特定目标解决了一个阻碍该领域进展的问题：再灌注神经元中蛋白质合成的不可逆抑制如何导致细胞死亡。公共卫生相关性：每年有数百万人因心脏骤停或中风引起的脑损伤而受伤或死亡。目前还没有治疗方法来防止这种脑损伤，因为医生和科学家不知道细胞是如何在血液停止流入大脑并随后恢复的一段时间后死亡的。这项提案中的工作旨在进一步了解大脑中的神经元在低血流量或无血流量（缺血）后恢复正常血流量（再灌注）的方式。