Mechanisms of Platelet Activity in Vascular Disease

项目总结/摘要 据估计，美国有1500万至2000万人患有外周动脉疾病（PAD）。尽管 随着医学治疗的进步，PAD仍然与相当大的心脏和肢体发病率相关， mortality.目前，在下肢进行的侵入性手术比在心脏进行的侵入性手术更多， 表明先进PAD系统的成本增加。虽然冠状动脉的发病机制 疾病（CAD）的特征很好，PAD的病理生理学了解较少，其机制 调节这种复杂紊乱的机制仍然不确定。虽然抗血小板治疗（作为类效应）减少 PAD的发生率和并发症，我们注意到抗血小板治疗的有效性不同， PAD和其他血管表型之间的关系。与CAD相比，阿司匹林对PAD不是特别有效 更有效的P2 Y12抑制也没有临床益处。显然，需要新的方向来更好地 了解血小板在PAD发病机制中的作用，并确定新的治疗靶点。我们集团 证明了编码和非编码RNA在调节血小板活性中的重要性。利用我们 建立了血小板活性表型良好的PAD患者队列，我们证明了 血小板-白细胞相互作用（与血小板-血小板聚集相反）在PAD发病机制中的作用。 此外，我们发现PAD中血小板的转录后调节异常，并证明 血小板在活化单核细胞和促进PAD中的炎症中起中心效应子作用。这里我们 建议全面研究（1）血小板活性，（2）血小板 转录组和（3）PAD患者的效应细胞特性。我们将分析储存的血小板样本 从> 1，000名纵向随访的患者中，其中许多人提供了连续收集。利用这些 有价值的血小板样本，我们将专注于识别与血管相关的新型血小板转录本， 表型和偶发心血管事件。例如，我们将比较（1）PAD与其他 血管表型（例如，CAD、颈动脉狭窄、腹主动脉瘤），（2）稳定的PAD与CLI， 和（3）突发心脏（心肌梗死）与肢体（大截肢）事件。机制研究使用 培养的巨核细胞和具有血小板特异性敲入和敲除候选物的动物模型 基因将描述这些过程是如何被调节的。我们也有能力验证我们的发现 在完善的地方，国家和国际队列中。我们的数据表明，这些类型的研究可以 为我们理解影响发病机制的机制提供了概念上的进展， PAD的严重性。这些见解可以用来设计临床生物标志物和治疗策略， 治疗和预防血管疾病及其危及生命的并发症。

PROJECT SUMMARY/ABSTRACT An estimated 15–20 million people in the United States have peripheral artery disease (PAD). Despite advances in medical therapy, PAD remains associated with considerable cardiac and limb morbidity and mortality. Currently, more invasive procedures are performed in the lower extremities than in the heart, demonstrating increasing costs to the system of advanced PAD. Although the pathogenesis of coronary artery disease (CAD) is well characterized, the pathophysiology of PAD is less understood and the mechanism(s) that regulate this complex disorder remain uncertain. While antiplatelet therapy (as a class effect) decreases the incidence and complications from PAD, we noted that the effectiveness of antiplatelet therapy differs between PAD and other vascular phenotypes. In contrast to CAD, aspirin was not particularly effective in PAD nor was there clinical benefit with more potent P2Y12 inhibition. Clearly, new directions are needed to better understand the role of platelets in PAD pathogenesis and identify new therapeutic targets. Our group demonstrated the importance in coding and noncoding RNAs in regulating platelet activity. Leveraging our established cohort of PAD patients with well-phenotyped platelet activities, we demonstrated the importance of platelet–leukocyte interactions (in contrast to platelet–platelet aggregation) in the pathogenesis of PAD. Moreover, we identified an aberrant post-transcriptional regulation of platelets in PAD and demonstrated that platelets play a central effector role in activating monocytes and fostering inflammation in PAD. Here, we propose to comprehensively investigate the relationship between (1) platelet activity, (2) the platelet transcriptome, and (3) effector cell properties in patients with PAD. We will analyze stored platelet samples from >1,000 patients with longitudinal follow-up, many of whom provided serial collections. Leveraging these valuable platelet samples, we will focus on identifying novel platelet transcripts associated with vascular phenotypes and incident cardiovascular events. For example, we will compare patients with (1) PAD vs. other vascular phenotypes (e.g., CAD, carotid artery stenosis, abdominal aortic aneurysm), (2) stable PAD vs. CLI, and (3) incident cardiac (myocardial infarction) vs. limb (major amputation) events. Mechanistic studies using both cultured megakaryocytes and animal models with platelet-specific knock-in and knock-out of candidate genes will characterize how these processes are regulated. We are also well positioned to validate our findings in well-established local, national, and international cohorts. Our data suggest these types of studies can provide conceptual advances in our understanding of the mechanisms influencing the pathogenesis and severity of PAD. These insights could be leveraged to design clinical biomarkers and therapeutic strategies to treat and prevent vascular disease and its life-threatening complications.