Neuron-Dervied S1P and Endothelial Function in Stroke

神经元衍生的 S1P 和中风中的内皮功能

• 批准号: 7098434
• 负责人: CHRISTIAN WAEBER
• 金额: $ 41.06万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-15 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7098434
• 关键词: RNA interference; angiogenesis; apoptosis; cell surface receptors; cerebral ischemia /hypoxia; genetically modified animals; glia; ischemia; laboratory mouse; laboratory rat; neurons; nitric oxide synthase; sphingosine; stroke; vascular endothelium

DESCRIPTION (provided by applicant): Stroke is a major cause of death and disability and brain blood vessels have been implicated. Stroke outcome is worsened by endothelial cell (EC) apoptosis, failure of angiogenesis and insufficient growth of collateral vessels. In brain EC, sphingosine-1-phosphate (S1P) induces Akt/endothelial nitric oxide synthase (eNOS) activation, suppresses apoptosis and induces proliferation. Neurons, and possibly glial cells, are a source of S1P in ischemia because a S1P synthesizing enzymes (sphingosine kinase 2, SPK2) is upregulated in neurons following oxygen glucose deprivation (OGD) and middle cerebral artery occlusion in mice. We hypothesize that following cerebral ischemia, S1P exerts antiapoptotic and pro-angiogenic effects on EC. Three specific aims will test the hypothesis that S1P activates EC S1P1 receptors and the Akt/eNOS cascade, protecting EC from apoptosis and inducing neovascularization. Aim 1 will confirm and characterize the protective effect of S1P on EC after OGD, as well as the induction of proliferation in these cells. We propose that S1P1 receptors, Akt and eNOS play a key role in these effects. Aim 2 will extend preliminary findings showing that neurons can be a relevant source of S1P during stroke and that neuron-derived S1P could mediate the survival and proliferation of brain EC observed in Aim 1. With the use of specific inhibitors, and RNA interference technology, we will determine the role of the SPK2 subtype, and whether neuronal S1P acts mediates the above effects via S1P1 receptors. Aim 3 will examine the in vivo significance of SPK2 up-regulation and the activation of the S1P1/Akt/eNOS system following ischemia in mice. We hypothesize that administration of FTY720 (a pro-drug converted to a S1P receptor agonist by SPK2, but not SPK1) will protect EC function, enhance EC proliferation and induce neovascularization following stroke via SPK2, S1P1 and Akt/eNOS. This project will study a novel system that can provide long-lasting improvement in EC function following stroke and serve as a target for stroke therapy.

描述（由申请人提供）：中风是死亡和残疾和脑血管的主要原因。内皮细胞（EC）细胞凋亡，血管生成失败和副血管生长不足，中风结果恶化。在脑EC中，鞘氨醇1-磷酸（S1P）诱导Akt/内​​皮一氧化氮合酶（ENOS）激活，抑制凋亡并诱导增殖。神经元以及可能的神经胶质细胞是缺血中S1P的来源，因为在氧气葡萄糖剥夺（OGD）和中大脑中动脉的神经元中，神经元中S1P合成酶（鞘氨醇激酶2，SPK2）在小鼠中的神经元中上调。我们假设脑缺血后，S1P对EC产生抗凋亡和促血管生成作用。三个具体目的将检验以下假设：S1P激活EC S1P1受体和AKT/ENOS级联反应，从而保护EC免受凋亡和诱导新生血管的影响。 AIM 1将确认并表征OGD后S1P对EC的保护作用，以及这些细胞中增殖的诱导。我们建议S1P1受体（AKT和ENOS）在这些效果中起关键作用。 AIM 2将扩展初步发现，表明神经元可以是中风过程中S1P的相关来源，而神经元衍生的S1P可以介导目标1中观察到的脑EC的存活和增殖。使用特定抑制剂和RNA干扰技术，我们将确定SPK2亚型和神经元的作用。 AIM 3将检查SPK2上调的体内意义以及小鼠缺血后S1P1/AKT/ENOS系统的激活。我们假设施用FTY720（通过SPK2转化为S1P受体激动剂的fty720，但不是SPK1）将保护EC功能，增强EC的增殖并通过SPK2，S1P1和AKT/AKT/ENOS进行中风后的新血管化。该项目将研究一个新型系统，该系统可以在中风后提供持久的EC功能，并作为中风治疗的目标。