Limiting brain reperfusion injury by controlling mitochondrial function

通过控制线粒体功能限制脑再灌注损伤

• 批准号: 9149032
• 负责人: MAIK HUETTEMANN
• 金额: $ 33.67万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-30 至 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9149032
• 关键词: Affect; Algorithms; Apoptosis; Area; Astrocytes; Attenuated; Blood flow; Brain; Brain Injuries; Brain Ischemia; Calcium; Cardiopulmonary Resuscitation; Cause of Death; Cell Death; Cellular Stress; Cerebrovascular Disorders; Cerebrum; Cessation of life; Data; Electron Transport; Enzymes; Event; Free Radical Formation; Free Radicals; Gel; Generations; Goals; Heart Arrest; Human; Hyperactive behavior; Image; In Vitro; Inflammation; Interruption; Ischemia; Lead; Light; Mammals; Mass Spectrum Analysis; Mediating; Membrane Potentials; Metabolic; Microglia; Mitochondria; Mitochondrial Proteins; Modeling; Morbidity - disease rate; Neurologic; Neurons; Oligodendroglia; Oxidases; Oxygen; Patient-Focused Outcomes; Pharmaceutical Preparations; Phase; Phosphorylation; Phototherapy; Process; Production; Property; Protein Dephosphorylation; Proton Pump; Rattus; Reactive Oxygen Species; Reperfusion Injury; Reperfusion Therapy; Research; Respiration; Resuscitation; Site; Stress; Testing; Therapeutic; Time; Tissues; cytochrome c oxidase; disability; in vivo; indexing; irradiation; mitochondrial membrane; mortality; natural hypothermia; neuroprotection; phosphoproteomics; prevent; public health relevance; restoration

 DESCRIPTION (provided by applicant): Cerebrovascular disease, most notably brain ischemia, is a leading cause of death and long-term disability in the US. The current and only treatment is prompt restoration of blood flow to the ischemic tissue. However, a substantial portion of the damage caused by ischemia/reperfusion occurs during the reperfusion phase: as ischemic tissue is reoxygenated reactive oxygen species (ROS) are quickly generated, starting early during reflow. Reperfusion injury has proved difficult to treat pharmacologically, likely because effective drug concentrations have not built up sufficiently during the early phase of reperfusion. The mitochondrial electron transport chain (ETC) is a major site of ROS production during cellular stress due to ETC hyper-activation, which causes high mitochondrial membrane potentials (ΔΨm), which in turn trigger excessive ROS production. We thus propose that the ideal therapy should target the ETC non-invasively to prevent the generation of ROS from the onset of reflow. Accordingly, our overall goal in this application is to develop a new, non-invasive therapy to normalize mitochondrial hyperactivity during reflow. We will capitalize on the photoreceptive properties of cytochrome c oxidase (COX) for infrared light (IRL) to modulate mitochondrial activity, thereby attenuating the production of ROS and, as a result, limit ischemia/reperfusion injury in the brain. Cytochrome c oxidase is the primary cellular photo-acceptor of IRL and the terminal enzyme of the ETC. We have discovered four specific IRL wavelengths that partially inhibit COX (instead of activating COX, i.e., the current paradigm). We show that inhibitory IRL, applied at the time of reperfusion, provides profound neuroprotection. In this proposal, we will build on these compelling preliminary data and capitalize on the unique, multi-disciplinary expertise of our research team to: Identify the combinations and energies of our four IRL wavelengths that yield optimal inhibition of COX and mitochondria in vitro using isolated rat brain COX and mitochondria (Aim 1). Investigate the mechanism of IRL-mediated protection in support of our central hypothesis of IRL action during reperfusion: IRL → COX activity↓ → ΔΨm↓ → ROS↓ → viability↑, using real-time imaging of mitochondrial funtion in rat primary neural cells exposed to simulated ischemia-reperfusion (Aim 2). Develop IRL-mediated protection and identify the optimal temporal treatment paradigm using a rat model for global brain ischemia to maximize post-ischemic neuroprotection (Aim 3).

 描述（由申请人提供）：脑血管疾病，尤其是脑缺血，是美国死亡和长期残疾的主要原因。当前唯一的治疗方法是立即恢复缺血组织的血流。然而，由缺血/再灌注造成的大部分损伤发生在再灌注阶段：当缺血组织重新充氧时，活性氧 (ROS) 会迅速产生，并在回流期间早期开始。再灌注损伤已被证明很难用药物治疗，可能是因为在再灌注的早期阶段有效的药物浓度尚未充分建立。线粒体电子传递链 (ETC) 是细胞应激期间 ROS 产生的主要部位，由于 ETC 过度激活，导致线粒体膜电位 (ΔΨm) 高，进而引发过量 ROS 产生。因此，我们建议理想的治疗方法应该是非侵入性地靶向 ETC，以防止回流开始时产生 ROS。因此，我们在此应用中的总体目标是开发一种新的非侵入性疗法，以使回流期间线粒体过度活跃正常化。我们将利用细胞色素 C 氧化酶 (COX) 的红外光 (IRL) 感光特性来调节线粒体活性，从而减少 ROS 的产生，从而限制大脑缺血/再灌注损伤。细胞色素c氧化酶是IRL的主要细胞光受体和ETC的末端酶。我们发现了四种特定的 IRL 波长，可以部分抑制 COX（而不是激活 COX，即当前的范例）。我们证明，在再灌注时应用抑制性 IRL 可提供深远的神经保护。在本提案中，我们将基于这些令人信服的初步数据，并利用我们研究团队独特的多学科专业知识来：确定我们的四个 IRL 波长的组合和能量，使用分离的大鼠脑 COX 和线粒体在体外产生对 COX 和线粒体的最佳抑制（目标 1）。使用暴露于模拟缺血再灌注的大鼠原代神经细胞中线粒体功能的实时成像（目标 2），研究 IRL 介导的保护机制，以支持我们在再灌注期间 IRL 作用的中心假设：IRL → COX 活性↓ → ΔΨm↓ → ROS↓ → 活力↑。使用全脑缺血大鼠模型开发 IRL 介导的保护并确定最佳时间治疗范例，以最大限度地提高缺血后神经保护（目标 3）。