Oxidative Stress and Pathological Glutamate Release in Stroke

中风中的氧化应激和病理性谷氨酸释放

• 批准号: 9765947
• 负责人: Alexander A Mongin
• 金额: $ 46.16万
• 依托单位: ALBANY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9765947
• 关键词: 7-nitroindazole; Acute; Address; Adult; Affect; Alteplase; American; Animals; Anions; Antioxidants; Astrocytes; Basic Science; Behavioral; Biological Assay; Blood - brain barrier anatomy; Blood Preservation; Blood Vessels; Blood flow; Brain; Brain Diseases; Brain Edema; Brain Injuries; Breeding; Cause of Death; Cell Membrane Permeability; Cells; Cerebrovascular Circulation; Chemicals; Clinical; Clinical Trials; Coagulation Process; Complex; Data; Developed Countries; Development; Dextrans; Disabled Persons; Extravasation; FDA approved; Family; Free Radical Scavengers; Genetic; Glutamate Receptor; Glutamates; Goals; Histologic; Human; Injury; Ischemia; Ischemic Brain Injury; Ischemic Penumbra; Japan; Knock-out; Knockout Mice; Lasers; Lead; Leucine-Rich Repeat; Link; LoxP-flanked allele; Measures; Mediating; Medicine; Microdialysis; Microfilaments; Middle Cerebral Artery Occlusion; Mission; Mitochondria; Modeling; Molecular; Mus; National Institute of Neurological Disorders and Stroke; Nature; Neuroglia; Neurons; Neurotransmitters; Nitrogen; Oxidants; Oxidation-Reduction; Oxidative Stress; Oxygen; Pathologic; Pathway interactions; Permeability; Pharmaceutical Preparations; Pharmacology; Process; Production; Property; Publishing; Rattus; Reactive Oxygen Species; Research; Research Personnel; Role; Signal Transduction; Site; Specificity; Stroke; Superoxide Dismutase; Superoxides; Swelling; Tamoxifen; Testing; Therapeutic; Therapeutic Agents; Tissues; Treatment Efficacy; United States National Institutes of Health; Viral; Work; acute stroke; base; behavioral outcome; brain size; channel blockers; clinically relevant; disability; improved; inhibitor/antagonist; innovation; ion channel blocker; knock-down; leucine-rich repeat protein; mimetics; neuroprotection; neurovascular; novel therapeutics; overexpression; oxidative damage; phenylmethylpyrazolone; sex; side effect; stroke model; stroke patient; stroke therapy; tempol; tool

SUMMARY Stroke is the fifth leading cause of death and the leading cause of adult long-term disability in the U.S. and other industrialized nations. Yet only one therapeutic agent (the clot-dissolving drug tPA) is approved for acute treatment. Among the critical injurious factors in stroke, oxidative stress is thought to contribute to the terminal steps of tissue damage. Antioxidants and free radical scavengers are highly protective in animal stroke models. Yet, for poorly understood reasons, they have shown limited or no benefits in clinical trials. In the prior NIH- sponsored project, we collected strong data which may help to revise our understanding of the mechanisms contributing to oxidative injury in ischemia: (1) In a rat model of stroke, we found that the superoxide dismutase (SOD) mimetic tempol was more protective than clinically used antioxidants. (2) Potent protection by tempol correlated with reduction of redox-sensitive glutamate release in the ischemic penumbra. (3) Glutamate release was mediated by at least two redox-sensitive mechanisms: volume-regulated anion channels (VRAC) and Ca2+- dependent changes in membrane permeability. (4) The glutamate-permeable VRAC was composed of proteins from the leucine-rich repeat-containing family 8 (LRRC8). We have assembled a synergistic team of investi- gators and propose to use highly innovative molecular and animal tools to test the HYPOTHESIS that reactive oxygen species (ROS, particularly superoxide anions) propagate and amplify stroke injury via stimulation of redox-sensitive glutamate release in the clinically relevant penumbra. In the planned studies we will address the following critical questions: (1) Is the LRRC8A-containing VRAC a viable target for neuroprotection in stroke? (2) Is glutamate release via the heteromeric LRRC8 channels responsible for tissue injury? (3) What is the chemical nature of the tempol-targeted ROS and the cellular site of their production? (4) Does glutamate release via VRAC drive disruption at the neurovascular interface (changes in blood flow and BBB integrity)? The immediate goal of the proposed work is to identify new molecular mechanisms that govern oxidative brain injury and determine the protective actions of antioxidants. Our long-term objective is to provide a blueprint for the development of new effective stroke therapies based on SOD mimetics and/or VRAC blockers.

概括 中风是美国和其他国家第五大死亡原因，也是成人长期残疾的主要原因 工业化国家。然而，只有一种治疗药物（溶栓药物 tPA）被批准用于治疗急性 治疗。在中风的关键损伤因素中，氧化应激被认为是导致中风终末期的原因之一。 组织损伤的步骤。抗氧化剂和自由基清除剂对动物中风模型具有高度保护作用。 然而，由于人们知之甚少的原因，它们在临床试验中显示出有限的益处或没有益处。在之前的 NIH- 赞助项目，我们收集了强有力的数据，这可能有助于修正我们对机制的理解 导致缺血中的氧化损伤：（1）在大鼠中风模型中，我们发现超氧化物歧化酶 (SOD) 模拟 tempol 比临床使用的抗氧化剂更具保护性。 (2) tempol的强效保护 与缺血半暗带中氧化还原敏感的谷氨酸释放的减少相关。 (3)谷氨酸释放 至少由两种氧化还原敏感机制介导：容量调节阴离子通道 (VRAC) 和 Ca2+- 膜渗透性的依赖性变化。 (4) 谷氨酸可渗透的VRAC由蛋白质组成 来自富含亮氨酸重复序列的家族 8 (LRRC8)。我们组建了一支具有协同作用的调查团队 鳄鱼并建议使用高度创新的分子和动物工具来测试反应性假设 氧物质（ROS，特别是超氧阴离子）通过刺激传播和放大中风损伤 临床相关半影中氧化还原敏感的谷氨酸释放。在计划的研究中，我们将 解决以下关键问题：(1) 含有 LRRC8A 的 VRAC 是否是神经保护的可行靶点 中风？ (2) 通过异聚 LRRC8 通道释放谷氨酸是否导致组织损伤？ (3) 什么 tempol 靶向 ROS 的化学性质及其产生的细胞位点是什么？ (4)是否含有谷氨酸 通过 VRAC 释放，驱动神经血管界面的破坏（血流和 BBB 完整性的变化）？这 拟议工作的直接目标是确定控制氧化脑的新分子机制 损伤并确定抗氧化剂的保护作用。我们的长期目标是提供蓝图 开发基于 SOD 模拟物和/或 VRAC 阻滞剂的新型有效中风疗法。