The role in inflammation in platelet activation and thrombosis

项目摘要 我的主要假设是，GAS 6/MERTK信号在炎症环境中上调，导致 增强的血小板活化反应、增加的血小板-白细胞相互作用和随后的血栓形成。 因此，我们认为抑制这一途径将减少血栓炎症。MERTK是一种受体 在血小板表面表达的酪氨酸激酶，当被其基于血浆的配体GAS 6刺激时， 导致血小板活化反应增强。我已经证明，抑制这个信号轴， 通过抗MERTK小分子抑制剂（UNC 2025）或新型可溶性MERTK剪接变体（iMer）降低 功能测定中的体外血小板活化和鼠模型中的体内血栓形成。我最近也 研究表明，与健康儿童相比，血栓形成儿童的血浆GAS 6水平升高， 这表明GAS 6也可能介导血栓形成（可能通过其桥接 膜结合磷脂酰丝氨酸和MERTK）。 在这个提议的项目中，我将严格调查炎症在血小板活化中的作用， 血栓形成，以及抑制GAS 6/MERTK信号传导影响的具体机制 血栓炎虽然我在血小板活化反应分析方面已经有了很强的研究基础 和小鼠血栓形成模型，该建议提供了所需的实验技能和知识基础 来评估炎症系统在这一特定背景下的作用。这一额外培训将 让我继续发展作为一个医生，科学家和执行过渡到一个独立的基本- 血栓炎症的转化研究生涯。 在此，我提出了三个具体目标：1）表征炎症对GAS 6/MERTK的影响， 信号传导和随后的体外血小板活化和体内血栓形成，2）通过以下方式定义机制： 其中GAS 6/MERTK信号传导影响血栓炎症，以及3）确定iMer在调节血栓炎症中的作用。 血小板中的GAS 6/MERTK信号传导。 我的导师团队由血小板活化和小鼠功能测定领域公认的领导者组成。 血栓形成模型（Jorge Di保拉博士，主要导师），以及 炎症（Sean Colgan博士，共同导师）。培训计划清楚地概述了我将如何推进研究 通过利用拟议的研究目标，在我以前的研究和经验的基础上进行职业发展， 教学课程工作，参加地方和国家会议，并从我的导师团队的指导， 奖学金监督委员会我专门设计了拟议的项目和相关的职业生涯 发展计划，以促进我过渡到独立调查员的长期目标是发展 减少炎症相关血栓形成的新策略。

Project Summary My primary hypothesis is that GAS6/MERTK signaling is upregulated in the setting of inflammation, leading to enhanced platelet activation responses, increased platelet-leukocyte interactions, and subsequent thrombosis. Therefore, we believe inhibition of this pathway will decrease thromboinflammation. MERTK is a receptor tyrosine kinase expressed on the platelet surface that, when stimulated by its plasma-based ligand GAS6, leads to augmentation of platelet activation responses. I have shown that inhibition of this signaling axis, either by anti-MERTK small molecule inhibitor (UNC2025) or a novel soluble MERTK splice variant (iMer) decreases in vitro platelet activation in functional assays and in vivo thrombosis in murine models. I also recently demonstrated that plasma GAS6 levels were elevated in children with thrombosis compared to healthy controls, suggesting that GAS6 may also mediate thrombosis (potentially through its ability to bridge membrane-bound phosphatidylserine and MERTK). In this proposed project, I will rigorously investigate the role of inflammation in platelet activation and thrombosis, as well as the specific mechanisms by which inhibition of GAS6/MERTK signaling impacts thromboinflammation. Though I already have a strong research base in platelet activation response assays and murine models of thrombosis, this proposal provides the experimental skills and knowledge base needed to evaluate the contributions of the inflammatory system in this particular context. This additional training will allow me to continue developing as a physician-scientist and execute the transition to an independent basic- translational research career in thromboinflammation. Herein, I propose three specific aims to 1) characterize the effect of inflammation upon GAS6/MERTK signaling and subsequent platelet activation in vitro and thrombosis in vivo, 2) define the mechanism through which GAS6/MERTK signaling impacts thromboinflammation, and 3) determine the role of iMer in regulating GAS6/MERTK signaling in platelets. My mentorship team consists of recognized leaders in functional assays of platelet activation and murine models of thrombosis (Dr. Jorge Di Paola, primary mentor), and cell-cell interactions in the setting of inflammation (Dr. Sean Colgan, co-mentor). The training plan clearly outlines how I will advance my research career development by building upon my previous studies and experience using the proposed research aims, didactic course-work, attendance at local and national meeting, and guidance from my mentorship team and scholarship oversight committee. I specifically designed the proposed project and associated career development plan to facilitate my transition to independent investigator with the long-term goal of developing novel strategies to decrease inflammation-related thrombosis.