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）：脑外伤诱导内皮和脑薄壁组织的炎症，共同称为神经血管单元。虽然神经元因创伤性脑损伤（TBI）而迅速死亡，但内皮细胞中炎症的恶性循环加剧了损伤。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。在TBI之后，在高水平下，过氧亚硝酸盐参与血液脑屏障（BBB）泄漏，酶促功能的改变和神经行为障碍。它激活了AMP激酶（AMPK），进而可以调节内皮一氧化氮合酶（ENOS）的超氧化物产生活性，从而维持神经炎症性继发性损伤的恶性循环。亚硝基化剂S-硝基谷硫硫代（GSNO）能够降低过氧亚硝酸盐的水平并抑制AMPK的活性。它还恢复谷胱甘肽的水平并保护神经血管单元的完整性。因此，这项研究将研究GSNO治疗是否通过亚硝基化来缓解TBI诱导的神经血管单位的神经炎症性损害。我们假设GSNO阻止了恶性AMPK/eNOS/过氧氮气周期，从而减少了TBI的神经血管损伤和有助于功能恢复。在特定的目标1中，将使用药理学剂（GSNO，过氧硝酸盐清除剂和AMPK选择性抑制剂）用作在受控的皮质撞击小鼠模型中剖析AMPK和TBI的调节的治疗工具。在特定的目标2中，将使用AMPK Alpha 1/2敲除小鼠，AMPKα过表达的转基因小鼠和野生型小鼠进一步检查和验证阐明机制。在特定的目标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活性和过氧亚硝酸盐的形成减少。补充药理学和遗传方法将决定AMPK在TBI中的作用。 GSNO与常规无捐助者不同，是无毒的内源性无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新的策略，以治疗神经炎性脑创伤，不仅针对其神经元后果，而且针对其血管原因和病情。公共卫生相关性：由于战争，事故和运动损伤，越来越多的年轻美国人遭受了脑部创伤。目前的治疗仅限于支持性护理，因为脑外伤性脑损伤的神经炎症机制尚不清楚。这种提出的机械干预的成功使用S-硝基谷胱甘肽将为治疗脑创伤提供一种新型的神经血管方法。