The Role of Layilin as a Novel Regulator of Platelet Activation and Thromboinflammation

炎症性肠病(IBD)是一种无法治愈的疾病，每年在美国影响约300万名患者 这个数字还在不断增加。IBD由两种密切相关的疾病组成，克罗恩病(CD)和溃疡性 结肠炎(UC)，通常表现在生命的前三十年，导致无情的炎症破坏 易感人群的胃肠道疾病。IBD患者血液处于高凝状态 血栓栓塞症(TE)，即危及生命的血液凝块破裂并在血流中流动 阻断其他血管，是导致IBD死亡的最重要原因。增加的风险在3%到15%之间- 分别在非活动期和活动期折叠。尸检研究报告血栓形成影响高达40%的 IBD患者和25%的发生血栓事件的患者会有致命的后果。目前的治疗方案 不考虑血栓形成的风险，广泛使用类固醇会增加风险。除了他们在 止血，血小板已经成为免疫反应的新调节器，起着重要的驱动作用 炎症和组织损伤。临床报告提示，血小板异常与IBD有关 活动性、严重性和血栓形成风险，然而，导致血小板增加的分子途径 IBD的反应性和血栓形成还没有得到很好的研究。这一建议检验了具有重大意义和创新性的 炎症性肠病患者血小板转录改变为过度激活的假说 C型凝集素赖氨林作为一种新的血小板活化和血栓形成调节剂。我们将聘用 互补的临床、体外和体内方法，一个独特的患者组织资源和专业知识 人类血小板和微血管内皮细胞，以及最先进的测序技术， CRISPR/Cas9技术和活体显微镜来严格检验这一假说。具体目标1将 确定在活动性和非活动性疾病期间，包括莱布林在内的血小板激活调节因子是如何改变的 炎症性肠病，并对疾病结果作出贡献。特定目标2将确定雷公藤红素如何调节血小板激活， 定义下游激活途径，并确定介导血小板与新的， 炎性透明质酸-电缆基质。具体目标3将确定如何确定目标路径 血小板中的雷公藤红素可改善结肠炎期间的炎症和血栓形成。这些目标的成功实现将 1)确定血小板转录变化如何促进炎性肠病的炎症和血栓形成，2) 确定莱布林介导的血小板激活的下游调节因子，3)确定靶向 调节失调的血小板激活通路改善小鼠结肠炎的炎症和血栓形成。数据 将极大地增加我们对高反应性血小板如何 对IBD的病理生理学有贡献。

A condition with no cure, inflammatory Bowel Disease (IBD) affects ~3 million patients in the US each year with the number ever increasing. IBD consists of two closely related disorders, Crohn’s disease (CD) and ulcerative colitis (UC), and usually manifest in the first three decades of life leading to relentless inflammatory destruction of the gastrointestinal tract in susceptible individuals. The blood of IBD patients exists in a hypercoagulable state and thromboembolism (TE), in which life-threatening blood clots break off and travel through the blood stream to block other vessels, is the most significant cause of mortality in IBD. This increased risk is between 3- and 15- fold during inactive and active disease respectively. Necropsy studies report thrombosis affects up to 40% of IBD patients, and 25% of patients suffering a thrombotic event have a fatal outcome. Current treatment regimens do not address thrombosis risk, and widespread steroid use increases risk. In addition to their classical role in hemostasis, platelets have emerged as novel regulators of the immune response that act as significant drivers of inflammation and tissue damage. Clinical reports suggest that platelet abnormalities associate with IBD activity, severity, and thrombosis risk, however molecular pathways responsible for increased platelet reactivity and thrombosis in IBD are not well studied. This proposal tests the significant and innovative hypothesis that platelets become transcriptionally altered toward hyperactivation in IBD and identified the C-type lectin layilin as a novel regulator of platelet activation and thrombosis. We will employ complementary clinical, in vitro, and in vivo approaches, a unique resource of patient tissues and expertise with human platelets and microvascular endothelial cells, along with state-of-the-art sequencing techniques, CRISPR/Cas9 technology, and intravital microscopy to rigorously test this hypothesis. Specific Aim 1 will determine how regulators of platelet activation, including layilin, are altered during active and inactive disease in IBD and contribute to disease outcomes. Specific Aim 2 will determine how layilin regulates platelet activation, define downstream activation pathways, and identify receptors and ligands mediating platelet adhesion to novel, inflammatory hyaluronan-cable matrices. Specific Aim 3 will establish how targeting pathways downstream of layilin in platelets improves inflammation and thrombosis during colitis. Successful completion of these aims will 1) determine how transcriptional changes in platelets contribute to inflammation and thrombosis in IBD, 2) determine downstream regulators of platelet activation mediated by layilin, 3) establish whether targeting dysregulated platelet activation pathways in improves inflammation and thrombosis in murine colitis. Data generated in this proposal will significantly increase our understanding of how the hyperreactive platelets contribute to the pathophysiology of IBD.