The role in inflammation in platelet activation and thrombosis

项目摘要 我的主要假设是Gas6/MERTK信号在炎症环境中上调，导致 增强的血小板激活反应，增加的血小板-白细胞的相互作用，以及随后的血栓形成。 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 表达在血小板表面的酪氨酸激酶，当被其血浆配体GAS6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，或者 通过抗MERTK小分子抑制剂(UNC2025)或一种新型的可溶性MERTK剪接变异体(Imer)减少 功能测定中的体外血小板活化和小鼠体内血栓形成。我也是最近 血栓形成患儿血浆Gas6水平较健康儿童升高 对照，提示Gas6也可能介导血栓形成(可能通过其桥接能力 膜结合的磷脂酰丝氨酸和MERTK)。 在这个拟议的项目中，我将严格研究炎症在血小板激活和 血栓形成以及抑制Gas6/MERTK信号影响的具体机制 血栓性炎症。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，这一建议提供了所需的实验技能和知识库 评估炎症系统在这一特定背景下的作用。这项额外的培训将 请允许我作为一名内科科学家继续发展，并执行向独立基础- 血栓炎症的翻译研究生涯。 在此，我提出了三个具体目标：1)表征炎症对Gas6/MERTK的影响 信号转导和随后的体外血小板激活和体内血栓形成，2)通过 哪些Gas6/MERTK信号影响血栓炎症，以及3)确定Imer在调节中的作用 血小板中的Gas6/MERTK信号转导。 我的指导团队由公认的血小板激活和小鼠功能分析方面的领导者组成 血栓形成的模型(Jorge Di Paola博士，主要导师)，以及在 炎症(肖恩·科尔根博士，共同导师)。培训计划清楚地概述了我将如何推进我的研究 职业发展以我以前的研究和经验为基础，利用拟议的研究目标， 讲授课程-工作，参加地方和全国会议，以及我的指导团队和 奖学金监督委员会。我专门设计了建议的项目和相关的职业 促进我向独立调查员过渡的发展计划，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.