Role of P450 Eicosanoids in Brain Microvasculature after Subarachnoid Hemorrhage

P450 类二十烷酸在蛛网膜下腔出血后脑微血管中的作用

基本信息

批准号：
8263751
负责人：
Dominic Aaron Siler
金额：
$ 4.72万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
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：
2011-04-20 至 2016-04-19
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8263751
关键词：
Accounting Acids Age Angiography Angiotensin II Angiotensin II Receptor Angiotensins Animals Arachidonic Acids Bioavailable Biochemistry Biological Blood Blood capillaries Brain Cardiovascular system Cause of Death Cerebral Aneurysm Cerebrum Clinical Clinical Treatment Clinical Trials Cytochrome P450 Data Development Diagnostic Eicosanoids Endothelium Enzymes Epoxide hydrolase Evaluation Genetic Hemorrhage Histology Hypertension Individual Injury Ischemia Knock-out Knockout Mice Left Life Liquid substance Mass Spectrum Analysis Measures Mediating Modeling Molecular Mus Neuroglia Neurologic Neurons Optics Pathogenesis Pathway interactions Patients Prevention Proteins Receptor Activation Research Resistance Resolution Role Rupture Signal Transduction Spasm Stroke Study models Subarachnoid Hemorrhage Survivors Technology Testing Therapeutic Time Transgenic Mice Up-Regulation Vasodilation Vasodilator Agents Vasospasm Western Blotting Work arteriole brain cell capillary cell type cerebral artery cerebrovascular constriction disability experience imaging modality in vivo inhibitor/antagonist interest killings liquid chromatography mass spectrometry microangiography mouse model neurobehavioral neurobehavioral test new therapeutic target novel optical imaging overexpression prevent public health relevance receptor success therapeutic target tool years of life lost

项目摘要

DESCRIPTION (provided by applicant): This year in the U.S. close to 800,000 people will suffer a stroke, making it the third leading cause of death. A particularly devastating form of this illness, subarachnoid hemorrhage (SAH), represents 25% of life years lost among all forms of stroke due to the relatively young age of its victims. A SAH occurs when large vessels in the brain rupture and bleed into the fluid filled space surrounding the brain. Patients recovering from SAH often develop delayed neurological deficit due to ischemia, killing a significant number, and leaving survivors with permanent disability. The pathogenesis of this injury is not well understood, and even though several promising mechanisms of delayed neurological deficit have been studied in great detail, treatments developed from this work have had limited success in clinical trials. A recently documented phenomenon that correlates with delayed neurological deficit is delayed microvascular spasm (dMVS). Until now, the technology available to document dMVS has only been able to do so at very low resolution. Using a novel in vivo optical imaging modality called optical microangiography (OMAG), we have been able to directly visualize microvessels within the mouse cortex and definitively identify dMVS after SAH. We propose to use neurobehavioral tests, histology, and biochemistry in addition to OMAG to explore a potential therapeutic target to prevent dMVS. Flow in brain microvessels is controlled by cytochrome P450 metabolites of arachidonic acid called epoxyeicosatrienoic acids (EETs). EETs are inactivated by the enzyme soluble epoxide hydrolase (sEH). Our preliminary data show that sEH knockout mice are protected from dMVS after SAH. We will test the hypothesis that SAH induces upregulation of sEH in cerebrovascular endothelium, leading to a decrease in bioavailable EETs and the development of dMVS and neurological deficit. In Specific Aim 1, we will test whether genetic deletion and pharmacological inhibition of sEH activity prevent dMVS and neurological deficit in mice after SAH. We will further characterize dMVS and neurological deficit after SAH using OMAG, neurobehavioral examination and histology. Finally, we will use transgenic mice with endothelial overexpression of sEH and the EETs biosynthetic enzyme P450 2J2, to confirm the role of endothelial sEH in modulating dMVS after SAH. In Specific Aim 2, we will measure changes in sEH expression and EETs within brain microvessels after SAH by Western blotting, real-time quantitative PCR, and mass spectrometry (LC-MS/MS). Additionally, we will test whether the upregulation of sEH after SAH is dependent on angiotensin signaling, which is known to be increased following SAH. This research aims to identify a novel therapeutic target for prevention of dMVS and delayed neurological deficit caused by SAH. PUBLIC HEALTH RELEVANCE: Individuals recovering from subarachnoid hemorrhage, a form of stroke, often live with significant disability due to delayed neurological deficit that arises well after the initial hemorrhage. Delayed microvascular spasm, a constriction of small resistance vessels and capillaries in the brain by an unknown cause, is associated with a significant number of patients who experience delayed neurological deficit. Here the aim is to study how disruption of a microvascular vasodilator pathway could cause delayed microvascular spasm after subarachnoid hemorrhage and subsequently, delayed neurological deficit.

描述（由申请人提供）：今年在美国，将近80万人将遭受中风，这使其成为第三大死亡原因。这种疾病的一种特别破坏性的形式，蛛网膜下腔出血（SAH）代表了由于受害者相对年轻的年龄而丧生的所有形式中的25％。当大脑中的大血管破裂并流入大脑周围的流体空间时，就会发生SAH。从SAH中恢复的患者通常由于缺血，大量杀死数量而导致的神经系统缺陷延迟，并使幸存者永久性残疾。这种损伤的发病机理尚未得到充分的理解，即使已经详细研究了延迟神经缺陷的一些有希望的机制，但根据这项工作开发的治疗方法在临床试验中取得了有限的成功。与延迟神经缺陷相关的最近记录的现象是延迟的微血管痉挛（DMV）。到目前为止，可用于记录DMVS的技术只能以非常低的分辨率进行。使用一种称为光学微型摄影（OMAG）的新型体内光学成像方式，我们能够直接可视化小鼠皮层内的微型花序，并在SAH后确定识别DMV。我们建议使用神经行为测试，组织学和生物化学，除了OMAG外，还可以探索预防DMV的潜在治疗靶标。脑微血管中的流量受到蛛网膜酸的细胞色素P450代谢产物的控制，称为环氧酸性酸（EET）。 EET被酶可溶性环氧水解酶（SEH）灭活。我们的初步数据表明，SAH后SEH敲除小鼠免受DMV的保护。我们将检验以下假设：SAH在脑血管内皮中诱导SEH的上调，从而导致生物利用EET的降低以及DMVS的发展和神经系统缺陷。在特定目标1中，我们将测试SAH后SEH活性的遗传缺失和药理抑制是否可以防止DMV和神经学不足。我们将进一步表征SAH后使用OMAG，神经行为检查和组织学后的DMV和神经学不足。最后，我们将使用具有SEH内皮过表达的转基因小鼠和Eets生物合成酶P450 2J2，以确认内皮SEH在SAH后调节DMV中的作用。在特定的目标2中，我们将通过蛋白质印迹，实时定量PCR和质谱法（LC-MS/MS）来衡量SAH SAH后SEH表达和EET的变化。此外，我们将测试SAH后SEH的上调是否取决于血管紧张素信号传导，SAH后已知会增加。这项研究旨在确定预防DMV和SAH引起的神经缺陷的新型治疗靶标。公共卫生相关性：从蛛网膜下腔出血中恢复的人，这是一种中风形式，通常由于延迟的神经缺陷而生存，这是最初出血后出现的延迟。延迟的微血管痉挛是大脑中小抗性血管和大脑毛细血管的收缩，与大量延迟神经缺陷的患者有关。这里的目的是研究微血管血管舒张途径的破坏如何导致蛛网膜下腔出血后的微血管痉挛延迟，随后会导致神经系统缺陷延迟。