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.

项目总结 该项目解决了促进脆弱组织缺血性损伤的潜在机制， 周围急性脑损伤，如中风。我们的长期目标是确定具体的机制， 将代谢受损的组织转变为受损的、易死亡的半影区并发展为临床相关 提高脑损伤后患者存活率的治疗目标。在了解脑缺血方法的同时 神经元损伤一直是主要的焦点，探索具体的后果和潜在的机制 治疗目标已经远远落后。本项目特别关注扩散去极化(SD) 最近被确定为对脆弱的伤害的进展有显著贡献的疾病 半影区。这些事件的主要焦点一直是它们对延长NMDA介导的钙离子的贡献 涌入和随后的破坏。然而，SD呈现了一个复杂得多、未被充分开发的Pre-Pre 突触阳离子释放和突触后摄取通过交替途径。具体地说，突触后 电压门控钙通道的激活与细胞外锌离子释放和摄取的增加有关 与SD的启动和随后的传播有关。我们的中心假设是SD导致的损伤进展 在代谢耗竭的组织中，由非NMDA为中心的阳离子动态平衡失调所介导。 此外，选择性地减少替代钙通道激活和/或减少后钙通道激活的药物。 突触摄取锌离子将减少SD后下游介导的损伤。我们将使用Brain 用切片和动物模型探讨锌、钙离子损伤的具体机制及药理作用 在SD发病期间和发病后对受损组织进行干预。具体目标1侧重于 神经元电压门控性钙通道参与突触后细胞内钙摄取的假说 导致下游单元执行。将使用一种特定的转基因药物来评估神经元的钙负荷 模型和药物干预将用于评估新陈代谢受损组织的恢复 布景。特异性目标2验证了锌离子稳态被破坏的假说有助于 易受伤害环境中SD诱导的损伤。脆弱组织中的锌波和特定的锌离子储存库将被 评估以探索破坏性水平在哪里释放。具体目标3然后评估这些机制在 活体环境中。在所有AIMS中，将使用电生理和成像技术来评估特定的 脑切片的机制(目标1和2)，然后转化为活体模型(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在哪里对损害和 确定这些阳离子的破坏性水平来自哪里。完成这些目标应确定具体的目标 钙、锌离子介导SD后易损组织损伤的机制及可能的靶点 临床预防范例。