Non-canonical mechanisms of excitotoxicity

兴奋性毒性的非典型机制

• 批准号: 10679904
• 负责人: Michael Bennett
• 金额: $ 3.96万
• 依托单位: UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10679904
• 关键词: Acute Brain Injuries; Address; Animal Model; Area; Blood Vessels; Brain; Brain Injuries; Cations; Cells; Cerebrovascular Circulation; Cessation of life; Clinical; Clinical Trials; Complex; Distal; Electrophysiology (science); Event; Failure; Future; Glutamates; Goals; Homeostasis; Hour; Imaging Techniques; Infarction; Injury; Intervention; Intervention Studies; Ischemia; Ischemic Stroke; Knock-out; Link; Literature; Measures; Mediating; Metabolic; Methods; Modeling; Mus; N-Methylaspartate; Neuronal Injury; Neurons; Outcome; Pathway interactions; Patients; Prevention; Proteins; Recovery; Research; Role; Slice; Source; Stroke; System; Testing; Therapeutic Intervention; Tissues; Toxic effect; Translating; Work; brain tissue; cell injury; chelation; clinically relevant; excitotoxicity; experimental study; extracellular; fluorescence imaging; hypoperfusion; imaging approach; improved; in vivo; in vivo Model; knock-down; neuroprotection; neurotoxic; novel; novel strategies; pharmacologic; postsynaptic; pre-clinical; presynaptic; prevent; receptor; stroke model; therapeutic target; uptake; voltage

PROJECT SUMMARY This project addresses the underlying mechanisms that progress ischemic damage of vulnerable tissue that surround acute brain injuries such as stroke. Our long-term goal is to identify the specific mechanisms that transition metabolically compromised tissue to damaged, pro-death penumbra and to develop clinically relevant therapeutic targets to improve patient survival after brain injury. While understanding of ischemic methods of neuronal injury has been the primary focus, exploring specific mechanisms of consequence and potential therapeutic targets has lagged far behind. This project looks specifically at Spreading Depolarizations (SDs) which have recently been identified as contributing significantly to the progression of injury in vulnerable penumbra. The main focus of these events has been on their contribution to prolonged NMDA-mediated Ca2+ influx and subsequent damage. However, SDs present a much more complex and underexplored surge of pre- synaptic cation release and post-synaptic uptake through alternate pathways. Specifically both post-synaptic activation of voltage-gated Ca2+ channels and increase in extracellular Zn2+ release and uptake have been linked to the initiation and subsequent propagation of SD. Our central hypothesis is that SD-induced injury progression in metabolically depleted tissue is mediated by dysregulation of non-NMDA-centric cation homeostasis. Furthermore, agents that are selective to reduce alternative Ca2+ channel activation and/or decrease post- synaptic Zn2+ uptake will reduce the downstream mediated damage that occurs following SD. We will use brain slice and animal models to explore Zn2+ and Ca2+ specific mechanisms of injury as well as pharmacological intervention to support compromised tissue during and after onset of SD. Specific Aim 1 focuses on the hypothesis that neuronal voltage-gated Ca2+ channels contribute to post-synaptic uptake of intracellular Ca2+ and lead to downstream cell execution. Neuronal Ca2+ loading will be assessed using a specific genetically modified model and pharmacological intervention will be used to assess recovery in a metabolically compromised tissue setting. Specific Aim 2 tests the hypothesis that disruption of Zn2+ homeostasis contributes to mechanisms of SD-induced injury in vulnerable setting. Zn2+ wave in vulnerable tissue and specific stores of Zn2+ will be assessed to explore where damaging levels are released. Specific Aim 3 then assess these mechanisms in an in vivo setting. In all aims, both electrophysiological and imaging techniques will be used to assess specific mechanisms in brain slice (Aim 1 and 2) and then translate into in vivo model (Aim 3). Pharmacological intervention and specific knockdown models will explore where these cations contributions to damage and identify where damaging levels of these cations originate. Completion of these aims should ascertain specific mechanisms of Ca2+ and Zn2+-mediated injury following SD in vulnerable tissue and propose potential targets for clinical prevention paradigms.

项目概要 该项目探讨了导致脆弱组织缺血性损伤的潜在机制， 围绕中风等急性脑损伤。我们的长期目标是确定具体机制 将代谢受损的组织转变为受损的促死亡半暗带并发展出临床相关性 提高脑损伤后患者生存率的治疗目标。在了解缺血方法的同时 神经元损伤一直是主要关注点，探索后果和潜在的具体机制 治疗目标远远落后。该项目专门研究传播去极化（SD） 最近被确定对易受伤害的人的伤害进展有重大影响 半影。这些事件的主要焦点在于它们对延长 NMDA 介导的 Ca2+ 的贡献 涌入和随后的损害。然而，SD 呈现出更为复杂且尚未充分探索的预 突触阳离子通过替代途径释放和突触后摄取。特别是突触后 电压门控 Ca2+ 通道的激活与细胞外 Zn2+ 释放和摄取的增加有关 SD 的启动和随后的传播。我们的中心假设是 SD 诱导的损伤进展 代谢耗尽的组织中的 NMDA 是由非 NMDA 中心的阳离子稳态失调介导的。 此外，选择性减少Ca2+通道激活和/或减少后钙通道的药物 突触 Zn2+ 摄取将减少 SD 后发生的下游介导的损伤。我们会用大脑 切片和动物模型探索 Zn2+ 和 Ca2+ 的具体损伤机制以及药理作用 SD 发作期间和之后对受损组织进行干预以支持受损组织。具体目标 1 重点关注 假设神经元电压门控 Ca2+ 通道有助于突触后细胞内 Ca2+ 的摄取， 导致下游细胞执行。神经元 Ca2+ 负荷将使用特定的转基因进行评估 模型和药物干预将用于评估代谢受损组织的恢复情况 环境。具体目标 2 检验了以下假设：Zn2+ 稳态的破坏有助于机制 SD 在脆弱环境中引起的伤害。脆弱组织中的 Zn2+ 波和 Zn2+ 的特定储存将 评估以探索破坏性水平的释放情况。具体目标 3 然后评估这些机制 体内设置。在所有目标中，电生理学和成像技术将用于评估特定的 大脑切片中的机制（目标 1 和 2），然后转化为体内模型（目标 3）。药理作用 干预和特定的击倒模型将探索这些阳离子对损害和影响的贡献 确定这些阳离子的破坏水平源自何处。完成这些目标应确定具体的 脆弱组织 SD 后 Ca2+ 和 Zn2+ 介导的损伤机制，并提出潜在的靶点 临床预防范例。