Mechanisms of platelet exosome-mediated acute chest syndrome in sickle cell disease

血小板外泌体介导的镰状细胞病急性胸部综合征的机制

• 批准号: 9918971
• 负责人: Matthew D Neal
• 金额: $ 77.39万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-22 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9918971
• 关键词: Acute; Acute Lung Injury; Affect; American; Attenuated; Binding; Biochemical; Biocompatible Materials; Blood; Blood Platelets; Blood flow; CASP1 gene; Drug Delivery Systems; Drug Targeting; Dyes; Encapsulated; Functional disorder; Hemorrhage; Image; In Vitro; Inflammasome; Injury; Interleukin-1 Receptors; Interleukin-1 beta; Lipopolysaccharides; Lung; Mediating; Microcirculation; Microfluidics; Microscopy; Modeling; Mus; Pathogenesis; Patients; Physiological; Platelet Count measurement; Platelet aggregation; Role; Secondary to; Sickle Cell Anemia; Signal Transduction; Site; TLR4 gene; Testing; Thrombocytopenia; Thrombosis; Time; Transgenic Organisms; acute chest syndrome; arteriole; exosome; extracellular vesicles; high risk; human disease; in vivo; innovation; interleukin-1beta-converting enzyme inhibitor; live cell imaging; lung imaging; lung injury; mortality; multi-photon; nanomedicine; nanoparticle; neutrophil; novel; novel therapeutics; peripheral blood; prevent; recruit; vaso-occlusive crisis

PROJECT SUMMARY Acute chest syndrome (ACS), a type of acute lung injury, is one of the leading causes of mortality in Sickle Cell Disease (SCD). Current treatments for ACS are primarily supportive, and there is a critical need for rescue therapies that can halt the progression of ACS. ACS is often a sequela of acute systemic vaso-occlusive crisis and preceded by thrombocytopenia. However, the role of platelets in the pathogenesis of ACS remains largely unknown. We hypothesize that ACS involves NLRP3-inflammasome mediated release of IL-1β-carrying platelet exosomes in SCD, which promote platelet-neutrophil aggregation leading to arrest of blood flow in lung. We also propose that targeted inhibition of TLR4/NLRP3-caspase-1 signaling in platelets is a potential therapy for ACS. To test this hypothesis, we will use an integrative physiologic approach that utilizes our recently validated model of lipopolysaccharide (LPS) induced vaso-occlusive crisis in transgenic SCD mice, in vivo multi-photon excitation (MPE) imaging of the lung vasculature in live SCD mice, live cell imaging of SCD human blood flowing in microfluidic channels in vitro, SCD mice lacking caspase-1 in platelets and nanoparticle tracking analyses of exosomes. In Aim 1, we will determine whether release of IL-1β-carrying platelet exosomes in SCD promote platelet-neutrophil aggregates in pulmonary arterioles that result in loss of blood flow in the lung. In Aim 2, we will determine whether TLR4/NLRP3-inflammasome mediated activation of caspase-1 in platelets is responsible for release of IL-1β-carrying exosomes from platelets in SCD. We have developed platelet-targeted nanomedicine (PTN) that specifically recruits to sites of platelet aggregation and thrombosis in vivo for targeted drug delivery. In Aim 3, we will determine whether PTNs carrying TLR4 or caspase-1 inhibitors, or IL-1 receptor antagonist (IL-1RA) can selectively recruit to sites of platelet aggregation to block platelet exosome release and signaling, and stop platelet-neutrophil aggregation in the lung vasculature of SCD mice. This study will identify a novel, platelet-derived exosome-mediated mechanism contributing to ACS. The findings will also establish that delivery of TLR4 or caspase-1 inhibitor, or IL-1RA encapsulated in PTNs can be a potential rescue therapy for ACS in high risk SCD patients presenting with vaso-occlusive crisis and thrombocytopenia.

项目概要 急性胸部综合征 (ACS) 是一种急性肺损伤，是镰状细胞死亡的主要原因之一 疾病（SCD）。目前 ACS 的治疗主要是支持性的，迫切需要抢救 可以阻止 ACS 进展的疗法。 ACS 通常是急性全身性血管闭塞危象的后遗症 并先于血小板减少症。然而，血小板在 ACS 发病机制中的作用仍然很大程度上 未知。我们假设 ACS 涉及 NLRP3 炎性体介导的携带 IL-1β 的血小板的释放 SCD 中的外泌体可促进血小板-中性粒细胞聚集，导致肺部血流停滞。我们也 提出靶向抑制血小板中的 TLR4/NLRP3-caspase-1 信号传导是 ACS 的潜在治疗方法。 为了检验这一假设，我们将使用综合生理学方法，该方法利用我们最近验证的模型 脂多糖 (LPS) 诱导转基因 SCD 小鼠血管闭塞危机，体内多光子激发 (MPE) 活体 SCD 小鼠肺血管系统成像、SCD 人体血液流动的活细胞成像 体外微流体通道、血小板中缺乏 caspase-1 的 SCD 小鼠以及纳米颗粒跟踪分析 外泌体。在目标 1 中，我们将确定 SCD 中携带 IL-1β 的血小板外泌体的释放是否促进 血小板-中性粒细胞在肺小动脉中聚集，导致肺部血流减少。在目标 2 中，我们 将确定 TLR4/NLRP3 炎症小体介导的血小板中 caspase-1 的激活是否负责 用于从 SCD 血小板中释放携带 IL-1β 的外泌体。我们开发了针对血小板的 纳米药物（PTN），专门招募体内血小板聚集和血栓形成部位，以实现靶向治疗 药物输送。在目标 3 中，我们将确定 PTN 是否携带 TLR4 或 caspase-1 抑制剂，或 IL-1 受体 拮抗剂（IL-1RA）可以选择性地募集到血小板聚集位点，从而阻止血小板外泌体的释放和 信号传导，并阻止 SCD 小鼠肺血管系统中的血小板-中性粒细胞聚集。这项研究将确定一个 血小板衍生的外泌体介导的 ACS 的新机制。研究结果还将确定 递送封装在 PTN 中的 TLR4 或 caspase-1 抑制剂或 IL-1RA 可能是一种潜在的救援疗法 高危 SCD 患者的 ACS 表现为血管闭塞危象和血小板减少症。