Nitrosylation Mechanisms for Protection Against Neurovascular Inflammatory Injury

预防神经血管炎症损伤的亚硝基化机制

基本信息

批准号：
8259741
负责人：
Avtar K Singh
金额：
$ 32.27万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-05-01 至 2016-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8259741
关键词：
5&apos -AMP-activated protein kinase Accidents American Animal Model Arginine Athletic Injuries Biological Availability Blood - brain barrier anatomy Blood Vessels Brain Diffusion Edema Endothelial Cells Endothelium Engineered Gene Enzymes Event Extravasation Figs - dietary Genetic Glutathione Impairment Inflammation Inflammatory Injury Intervention Ischemia Knockout Mice Lead Mediating Mediator of activation protein Modeling Modification Mus Necrosis Neurons Nitric Oxide Nitric Oxide Donors Nitrogen Oxygen Pathway interactions Peroxonitrite Phosphorylation Process Production Reaction Recovery of Function Regulation Reperfusion Therapy Reporting Role S-Nitrosoglutathione STK11 gene Signal Transduction Stroke Superoxides Supportive care Testing Therapeutic Transgenic Mice Traumatic Brain Injury War Wild Type Mouse adenylate kinase base clinically relevant cofactor controlled cortical impact human NOS3 protein in vivo inhibitor/antagonist mouse model neurobehavior neurobehavioral neuron loss neurovascular unit novel public health relevance success tetrahydrobiopterin tool treatment strategy upstream kinase

项目摘要

DESCRIPTION (provided by applicant): Brain trauma induces inflammation in both the endothelium and the brain parenchyma, collectively termed the neurovascular unit. While neurons die quickly by necrosis following traumatic brain injury (TBI), a vicious cycle of inflammation in endothelial cells exacerbates the injury. In activated endothelial cells, excessive superoxide reacts with nitric oxide (NO) to form peroxynitrite. At high levels following TBI, peroxynitrite is involved in blood brain barrier (BBB) leakage, altered enzymatic functions, and neurobehavior impairment. It activates AMP Kinase (AMPK), which in turn may up regulate the superoxide-producing activity of endothelial nitric oxide synthase (eNOS), and thus maintains a vicious cycle of neuroinflammatory secondary injury. The nitrosylating agent S-nitrosoglutathione (GSNO) is capable of reducing the levels of peroxynitrite and inhibiting the activity of AMPK. It also restores the levels of glutathione and protects the integrity of the neurovascular unit. Therefore, this study will investigate whether GSNO treatment ameliorates TBI-induced neuroinflammatory damage to the neurovascular unit via nitrosylation. We hypothesize that GSNO blocks the vicious AMPK/eNOS/peroxynitrite cycle, thus reducing the neurovascular injury and aiding functional recovery in TBI. In Specific Aim 1, pharmacological agents (GSNO, a peroxynitrite scavenger, and an AMPK selective inhibitor) will be used as therapeutic tools to dissect the regulation of AMPK and amelioration of TBI in a controlled cortical impact mouse model. In Specific Aim 2, the elucidated mechanisms will be further examined and validated using AMPK alpha 1/2 knockout mice, AMPK alpha over-expressing transgenic mice, and wild type mice. In Specific Aim 3, we will determine whether GSNO-mediated nitrosylation of either AMPK or its upstream kinase LKB1 is responsible for the inhibition of aberrant eNOS activity and the reduced formation of peroxynitrite. The complementary pharmacological and genetic approach will determine the role of AMPK in TBI. GSNO, unlike conventional NO donors, is a non-toxic endogenous NO modulator and nitrosylating agent. Understanding S-nitrosylation mechanism and the unique AMPK/eNOS/peroxynitrite pathway may lead to new strategies for the treatment of neuroinflammatory brain trauma that target not only its neuronal consequences but also its vascular causes and exacerbations. PUBLIC HEALTH RELEVANCE: As a consequence of war, accidents and sport injury, an increasing number of young Americans are suffering from brain trauma. Current treatment is limited to supportive care because the neuroinflammatory mechanisms of traumatic brain injury are not well understood. The success of this proposed mechanistic intervention using S-nitrosoglutathione would provide a novel neurovascular approach to treating brain trauma.

描述（由申请人提供）：脑外伤会诱发内皮细胞和脑实质（统称为神经血管单元）的炎症。虽然神经元在创伤性脑损伤 (TBI) 后会因坏死而迅速死亡，但内皮细胞炎症的恶性循环会加剧损伤。在活化的内皮细胞中，过量的超氧化物与一氧化氮 (NO) 反应形成过氧亚硝酸盐。 TBI 后高水平的过氧亚硝酸盐会导致血脑屏障 (BBB) 渗漏、酶功能改变和神经行为损伤。它激活 AMP 激酶 (AMPK)，进而上调内皮一氧化氮合酶 (eNOS) 产生超氧化物的活性，从而维持神经炎症继发性损伤的恶性循环。亚硝基化剂 S-亚硝基谷胱甘肽 (GSNO) 能够降低过氧亚硝酸盐的水平并抑制 AMPK 的活性。它还可以恢复谷胱甘肽的水平并保护神经血管单元的完整性。因此，本研究将探讨 GSNO 治疗是否可以通过亚硝基化改善 TBI 诱导的神经血管单元神经炎症损伤。我们假设 GSNO 可以阻断 AMPK/eNOS/过氧亚硝酸盐的恶性循环，从而减少神经血管损伤并有助于 TBI 的功能恢复。在具体目标 1 中，药物制剂（GSNO、过氧亚硝酸盐清除剂和 AMPK 选择性抑制剂）将用作治疗工具，在受控皮质冲击小鼠模型中剖析 AMPK 的调节和 TBI 的改善。在特定目标 2 中，将使用 AMPK α 1/2 敲除小鼠、AMPK α 过表达转基因小鼠和野生型小鼠进一步检查和验证阐明的机制。在具体目标 3 中，我们将确定 GSNO 介导的 AMPK 或其上游激酶 LKB1 的亚硝基化是否负责抑制异常的 eNOS 活性和减少过氧亚硝酸盐的形成。互补的药理学和遗传学方法将决定 AMPK 在 TBI 中的作用。 GSNO 与传统的 NO 供体不同，是一种无毒的内源性 NO 调节剂和亚硝基化剂。了解 S-亚硝基化机制和独特的 AMPK/eNOS/过氧亚硝酸盐途径可能会带来治疗神经炎症性脑损伤的新策略，不仅针对其神经元后果，还针对其血管原因和恶化。公共卫生相关性：由于战争、事故和运动损伤，越来越多的美国年轻人遭受脑外伤。目前的治疗仅限于支持性护理，因为创伤性脑损伤的神经炎症机制尚不清楚。这种使用 S-亚硝基谷胱甘肽进行机械干预的成功将为治疗脑外伤提供一种新的神经血管方法。