NOVEL ROLE OF SPHINGOLIPIDS IN MAINTAINING VASCULAR HOMEOSTASIS

项目摘要 为K08应用程序提出的研究将使用独特的方法来检查 人体血管系统内血流诱导血管扩张(FID)中介物上的鞘磷脂代谢。 最近有研究表明神经酰胺，一种已知在血浆中升高的具有生物活性的鞘磷脂。 心血管疾病患者，是主要不良心血管事件的独立预测因素。一个 神经酰胺可能对预后产生不利影响的潜在方式是最近发现的对血管紧张素转换酶的介体的作用 FID。暴露于神经酰胺的小动脉因血流而扩张，产生过氧化氢，一种促炎和促炎因子. 动脉粥样硬化介质，而不是一氧化氮(NO)，即抗炎、抗动脉粥样硬化的介质 供健康的成年人使用，以应对增加的流量。相反，鞘氨醇-1-磷酸(S1P)也 在鞘脂家族中，神经酰胺的代谢物，促进NO依赖的FID。神经鞘脂类如何 影响血流过程中形成的血管活性介质和影响血管内环境平衡在很大程度上仍不清楚。 这项提案的目的是研究鞘脂的平衡，也被称为‘鞘脂变阻器’， 影响特定FID介体的生成，这将对FID的形成或 预防炎症和动脉粥样硬化。总的来说，该应用程序是实现以下目标的必要的第一步 明确FID过程中鞘脂代谢在人体微循环中的机制作用。 颁奖阶段的培训计划将从四个方面扩展我的科学技能。首先，我会 使用已建立的人类血管反应性模型扩展我的培训和经验，以研究如何 鞘脂代谢和S1P：神经酰胺的比例决定了FID的介体。第二，在一次 在王瑞康博士的实验室休假，我将接受组织成像方面的培训，特别是活体成像 微血管成像，目标是采用一种新技术(细胞摄像头)将我们的发现转化为 整个人类。我还将接受安德鲁·莫里斯博士的培训，教我如何从小到大测量鞘脂 采用液-质联用(LC-MS/MS)对人体样品进行分析。此工具是 可在MCW获得，但尚未改装用于鞘脂测量。将这项技术引入MCW 我将极大地加强我的研究计划，并支持其他需要在小范围内量化脂质介体的人 组织样本。第三，我将完成生物统计学、助学金撰写、高级弥撒等正式课程 光谱技术、临床试验设计和医学成像。这些课程是由 我和我的指导团队来补充我的正规培训，并将在我继续的过程中提供重要的知识 发展成为一个独立的调查者。这一培训计划的第四个组成部分涉及承担 领导角色，如担任学生的导师，管理由临床医生和 研究人员，在国家会议上组织研讨会，并在科学咨询委员会任职 美国麻醉学学会。这些组件中的前三个已经在进行中。

Project Summary The studies proposed for this K08 application will use unique approaches to examine the effects of sphingolipid metabolism on the mediator of flow-induced vasodilation (FID) within the human vasculature. Recently it has been shown that ceramide, a bioactive sphingolipid known to be elevated in the plasma of patients with cardiovascular disease, is an independent predictor of major adverse cardiovascular events. A potential way ceramide could adversely affect outcomes is by its recently discovered effect on the mediator of FID. Arterioles exposed to ceramide dilate in response to flow by generating H2O2, a pro-inflammatory and pro- atherosclerotic mediator as opposed to nitric oxide (NO), the anti-inflammatory, anti-atherosclerotic mediator utilized by healthy adults in response to increased flow. On the contrary, sphingosine-1-phosphate (S1P), also within the sphingolipid family and a metabolite of ceramide, promotes NO-dependent FID. How sphingolipids affect vasoactive mediators formed during flow and impact vascular homeostasis remains largely unknown. The aims of this proposal examine how the balance of sphingolipids, also known as the `sphingolipid rheostat,' influences the generation of a specific FID mediator which will have a profound impact on the formation or prevention of inflammation and atherosclerosis. Overall this application represents the necessary first step to define the mechanistic role of sphingolipid metabolism during FID in the human microcirculation. The training plan during the award phase will expand my scientific skill set in four ways. First, I will expand my training and experience using an established human vascular reactivity model to investigate how sphingolipid metabolism and the S1P:ceramide ratio determine the mediator of FID. Second, during a sabbatical in the laboratory of Dr. Ruikang Wang, I will receive training in tissue imaging, specifically in vivo microvascular imaging, with the goal of adapting a new technology (CytoCam) to translate our findings to the whole human. I will also receive training from Dr. Andrew Morris, in how to measure sphingolipids from small human samples using liquid chromatography tandem mass spectrometry (LC MS/MS). This instrumentation is available at MCW but has not been adapted for sphingolipid measurements. Bringing this technology to MCW will greatly strengthen my research program and support others needing to quantify lipid mediators in small tissue samples. Third, I will complete formal coursework in biostatistics, grant writing, advanced mass spectrometry techniques, clinical trial design, and medical imaging. These courses were specifically chosen by me and my mentoring team to supplement my formal training, and will provide vital knowledge as I continue to develop into an independent investigator. The fourth component of this training plan involves taking on leadership roles, such as being a mentor to students, managing an affinity group consisted of clinicians and researchers, organizing symposia at national meetings, and serving on scientific advisory committees for the American Society of Anesthesiology. The first three of these components are already in progress.