Macrophage Pyroptosis in Abdominal Aortic Aneurysm

申请K99/R00的目的是(1)为我提供必要的研究和培训 职业发展为我过渡到一名成功的独立研究员；(2)研究角色 下垂，一种新的程序性细胞死亡形式，发生在腹主动脉破裂(AAA)。 AAA是一种进行性的主动脉病理性扩张和变弱。AAA与极端 主动脉破裂的死亡率(高达80%)。没有可以预防或治疗的药物。 主动脉破裂，这在很大程度上是由于AAA破裂的机制尚未得到 已定义。AAA的特点是炎症和血栓的频繁存在。炎症性病变 通常含有死亡细胞。直到最近，程序性细胞死亡被认为只以一种形式发生， 称为“细胞凋亡”。2015年和2016年，来自三个组织的四份《自然》出版物披露了Gasdermin D (GSDMD)依赖的上睑下垂机制。GSDMD在细胞表面形成毛孔，使细胞破裂 薄膜。在破裂的细胞膜中，磷脂酰丝氨酸，它专门位于细胞的内部 活细胞中的单层，自由翻转成外部单层，形成组织的促凝剂表面 通过促进凝血级联蛋白的组装而发挥作用。我们最近发现， 巨噬细胞脓毒症通过释放组织因子导致败血症死亡，从而引发播散 小鼠的血管内凝血。我的初步数据显示，GSDMD的遗传缺陷可以保护 抗血管紧张素II注射小鼠的AAA破裂。在这项提议中，我将检验假设 巨噬细胞下垂通过组织因子依赖的血栓传播促进AAA破裂。 两个目标将被用来检验这一假说。在目标1中，我将分析巨噬细胞松下症 血管紧张素II诱导Caspase-1和Caspase-11缺陷小鼠AAA断裂(K99期)。在……里面 目的2，我将确定巨噬细胞如何通过组织因子介导的机制， 导致AAA破裂(R00期)。我将一起研究两者之间的因果关系 血栓和AAA破裂，并测试巨噬细胞下垂之间前馈循环的概念 和组织因子/血栓直到腹主动脉破裂。这个项目很重要，因为GSDMD和下垂 可能代表了一个治疗靶点。这个项目具有创新性，因为它定义了一种新的促凝剂 AAA的作用机制。我还将检查人类主动脉瘤的巨噬细胞生物学和下垂。 贝勒医学院勒迈尔博士的主动脉疾病生物库中提供的组织可以增强 我提议的研究的翻译方面。

The purpose of this K99/R00 application is to (1) provide me with necessary training in research and career development for my transition to a successful independent researcher; (2) study the role of pyroptosis, a novel form of programmed cell death, in the rupture of Abdominal Aortic Aneurysm (AAA). AAA is a progressive pathological dilation and weakening of the aorta. AAA is associated with extreme rates of death (up to 80%) in the event of aortic rupture. There has no medical therapy to prevent or treat aortic rupture, which is largely attributed to that mechanisms underlying AAA rupture have not been defined. AAA is characterized by inflammation and frequent presence of thrombus. Inflammatory lesions often contain dead cells. Until recently, programmed cell death was thought to occur only in one form, called “apoptosis”. In 2015 and 2016, four Nature publications from three groups revealed gasdermin D (GSDMD)-dependent mechanisms of pyroptosis. GSDMD forms pores on cell surface and ruptures cell membrane. In ruptured cell membrane, phosphatidylserine, which is exclusively located in the inner monolayer in living cells, freely flip into outer monolayer and forms a procoagulant surface for tissue factor by facilitating the assembly of proteins of clotting cascade. We recently discovered that macrophage pyroptosis caused septic death through tissue factor release, which triggered disseminated intravascular coagulation in mice. My preliminary data show that genetic deficiency of GSDMD protects against AAA rupture in angiotensin II-infused mice. In this proposal, I will test the hypothesis that macrophage pyroptosis promotes AAA rupture through tissue factor-dependent thrombus propagation. Two aims will be addressed to test this hypothesis. In Aim 1, I will profile macrophage pyroptosis in angiotensin II-induced AAA rupture using caspase-1 and Caspase-11 deficient mice (K99 PHASE). In Aim 2, I will determine how macrophage pyroptosis, through tissue factor-mediated mechanisms, contributes to AAA rupture (R00 PHASE). Together I will examine the causal relationship between thrombus and AAA rupture and test the concept of a feedforward loop between macrophage pyroptosis and tissue factor/thrombus until AAA rupture. This project is important because GSDMD and pyroptosis may represent a therapeutic target. This project is innovative because it defines a novel procoagulant mechanism in AAA. I will also examine macrophage biology and pyroptosis in human aortic aneurysm tissues available in Dr. LeMaire’s Aortic Disease Biobank at Baylor College of Medicine to enhance the translational aspects of my proposed research.