Pathological flow-induced endothelial damage and plaque erosion

项目总结/摘要 动脉粥样硬化和高危斑块（包括破裂和糜烂）主要局限于血管 具有非层流扰动血流（D流）和层流高流量（H流）的壁区域。但 这种病理性血流诱导的高危斑块的分子机制在很大程度上仍不清楚， 由于缺乏此类高危斑块的动物模型，因此迫切需要弥补这一空白。 我们的长期目标是确定高风险斑块是如何通过病理性流动形成的。我们发现 在他莫昔芬诱导的细胞中诱导LATS（大肿瘤抑制基因同源物）1/2缺失后14天内， 内皮细胞（EC）特异性LATS 1 homo/LATS 2 homo敲除小鼠（LATS 1 homo/LATS 2 homo-EKO），所有小鼠 (28/28）死于严重的全身水肿，并伴有大量的EC凋亡。接下来我们生成了EC- 特异性LATS 1 het/LATS 2 homo-EKO高脂血症（H-chol）小鼠;我们检测到斑块糜烂样病变 在主动脉弓和颈动脉中的h-和d-流动区域，显示强纤维蛋白/纤维蛋白原阳性组织 没有大的坏死核心的血栓形成。我们观察到1）EC增殖，2） 具有衰老表型的EC凋亡，3）组织因子（TF）表达，和4）炎症，其是 统称为“促血栓形成表型”。我们假设病理性血流诱发 LATS 1/2降解促进内皮细胞损伤介导的血栓形成和管腔再内皮化 演唱会EC损伤-血栓-再内皮化的循环导致大血栓形成， 牙菌斑侵蚀病理性血流诱导的MAGI 1 S741通过PKC β磷酸化，以及随后的 LATS 1/2-TERF 2 IP-MKRN 1复合物的形成对LATS 1/2降解至关重要。为了验证这个假设， 我们提出以下三个目标。在目标1中，我们将描述过度EC增殖的作用， 衰老/凋亡、组织因子（TF）表达、炎症形成斑块糜烂样 EC特异性Lats 1het/Lats 2 homo基因敲除（Lats 1het/Lats 2 homo-EKO）小鼠的病变和斑块内出血 在H-chol手下在目标2中，我们将确定磷酸化依赖性TERF 2 IP和MKRN 1的关键作用， Ub E3连接酶在病理性血流诱导的LATS 1/2不稳定和随后的促血栓形成中的结合 在目的3中，我们将研究PKC β诱导的MAGI 1 S741磷酸化在 LATS 1/2介导的TERF 2 IP S205磷酸化和LATS 1/2降解。拟议的工作预计 建立病理性血流和血栓形成前表型之间的联系，通过这种联系， 形成了拟议的研究是创新的，因为它将提出一个新的概念， 内皮细胞，并诱导形成脆弱的斑块侵蚀，并将提供新的见解 信号级联和分子负责这种病理。这项研究还可能提供 预测和预防高危斑块形成的方法。

Project Summary/Abstract Atherosclerotic and high-risk plaques including both rupture and erosion are predominantly localized to vessel wall regions with non-laminar disturbed blood flow (d-flow) and laminar high flow (h-flow). However, the molecular mechanisms of this pathological flow-induced high-risk plaque remain largely unknown mainly because of the lack of such high-risk plaque animal models, hence there is an urgent need to correct this gap. Our long-term goal is to determine how the high-risk plaque is formed by pathological flow. We found that within 14 days after inducing LATS (large tumor suppressor homolog) 1/2 deletion in tamoxifen-inducible endothelial cell (EC) specific LATS1homo/LATS2homoknock-out mice (LATS1homo/LATS2homo-EKO), all mice (28/28) died of severe systemic edema, accompanied by massive EC apoptosis. Next we generated EC- specific LATS1het/LATS2homo-EKO hypercholesteremic (H-chol) mice; we detected a plaque erosion-like lesions at h- and d-flow areas in the aortic arch and carotids, which revealed strong fibrin/fibrinogen positive organized thrombus formation without a large necrotic core. We observed significant increases in 1) EC proliferation, 2) EC apoptosis with senescent phenotype, 3) tissue factor (TF) expression, and 4) inflammation, which are collectively referred to as the “pro-thrombotic phenotype”. We hypothesize that pathological flow-induced LATS1/2 degradation promotes EC damage-mediated thrombus formation and luminal re-endothelialization in concert. This cycle of EC damage-thrombus-re-endothelialization results in largethrombus formation and plaque erosion. Pathological flow-induced MAGI1 S741 phosphorylation by PKC, and the subsequent LATS1/2-TERF2IP-MKRN1 complex formation are essential for LATS1/2 degradation. To test ths hypothesis, we propose the following 3 aims. In aim 1, we will characterize the role of excess EC proliferation, senescence/apoptosis, tissue factor (TF) expression, and inflammation in the formation of plaque erosion-like lesions and intraplaque hemorrhage in EC specific Lats1het/Lats2homo knock-out (Lats1het/Lats2homo-EKO) mice under H-chol. In aim 2, we will determine the crucial role of phosphorylation dependent TERF2IP and MKRN1 Ub E3 ligase binding in pathological flow-induced LATS1/2 destabilization and the consequent pro-thrombotic phenotype, and in aim 3 we will Investigate the role of PKC-induced MAGI1 S741 phosphorylation in LATS1/2-mediated TERF2IP S205 phosphorylation and LATS1/2 degradation. The proposed work is expected to establish the link between pathological flow and pro-thrombotic phenotype, by which high-risk plaques are formed. The proposed study is innovative because it will propose a new concept how pathological flow affects the endothelium and induce the formation of vulnerable plaques of erosion and will provide insights into new signaling cascades and molecules responsible for this pathology. The proposed research may also provide means to predict and prevent high-risk plaque formation.