Platelet adhesion to neutrophil extracellular DNA traps: role in thrombosis

血小板与中性粒细胞胞外 DNA 陷阱的粘附：在血栓形成中的作用

• 批准号: 8105682
• 负责人: DENISA D WAGNER
• 金额: $ 52.88万
• 依托单位: IMMUNE DISEASE INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-15 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8105682
• 关键词: Address; Adhesions; Aging; Bacteria; Binding; Biological; Biological Assay; Biological Markers; Blood; Blood Platelets; Cell Adhesion Molecules; Cell Death; Cells; Chromatin; Coagulants; Coagulation Process; DNA; Deep Vein Thrombosis; Deposition; Disease; Disseminated Intravascular Coagulation; Enzymes; Event; Fibrin; Fibrinogen; Fibronectins; Generations; Genetically Engineered Mouse; Growth; Histology; Human; Imaging technology; In Vitro; Inferior vena cava structure; Integrins; Internet; Laboratories; Leukocytes; Ligation; Measures; Mediating; Microbe; Modeling; Molecular; Molecular Target; Mus; Mutant Strains Mice; Operative Surgical Procedures; Pathway interactions; Patients; Plasma; Platelet aggregation; Process; Production; Proteins; Pulmonary Embolism; Recruitment Activity; Role; Sampling; Sepsis; Severities; Specimen; Spiders; Staging; Stenosis; Structure; Thrombocytopenia; Thrombosis; Thrombus; Transfusion; United States; antimicrobial; deep vein; extracellular; genetically modified cells; in vivo; in vivo Model; intravital microscopy; killings; mouse model; neutrophil; receptor; scaffold; thrombolysis

DESCRIPTION (provided by applicant): Neutrophils undergo a cell death pathway that results in release of chromatin coated with antimicrobial proteins forming a web called neutrophil extracellular traps (NETs). NETs trap and kill microbes. Our preliminary results show that NETs recruit and activate platelets. We have evidence of extracellular DNA/chromatin presence in pathological specimens from deep vein thrombosis and in plasma of patients with thrombotic disease. The central hypothesis of this application is that NETs provide a scaffold that, together with fibrin, increases thrombus stability and promotes thrombus growth and microparticle recruitment. We propose that the formation of NETs in pathological circumstances could initiate thrombotic events and contribute to conditions such as sepsis, thrombotic microangiopathies and deep vein thrombosis. In addition, we propose that DNase1, which digests NETs, may modulate thrombosis. We will analyze NETs in the context of in vitro and in vivo models of thrombosis. We will employ a flow chamber with video capability using cells from genetically engineered mice. We propose to study several mouse models of thrombosis, all of which are well established in our laboratory, to visualize NETs formation in vivo with sophisticated imaging technology and study the relevance of NETs to thrombus growth and stability. We are particularly keen to investigate the role of NETs in a new inferior vena cava stenosis model of deep vein thrombosis (DVT) and in a mouse model of sepsis. The proposal has 2 specific aims: 1. To study the molecular mechanisms mediating platelet and microparticle interactions with NETs. To evaluate whether NETs promote fibrin generation. In this Aim, we propose to investigate in vitro the molecular mechanisms involved in platelet adhesion to NETs and address whether NETs promote recruitment of pro-coagulant microparticles (MPs) and fibrin deposition. 2. To study NETs formation in vivo and examine the biological relevance of NETs to sepsis-induced thrombocytopenia and to deep vein thrombosis. To measure NETs biomarkers in samples from patients with thrombosis. In this aim, we propose to visualize NETs by intravital microscopy and by histology. We propose to modulate NETs production and circulating DNA levels and see the effects on murine models of sepsis and DVT. We will study NETs as biomarkers in thrombosis. Thrombosis, including deep vein thrombosis/pulmonary embolism is now the biggest killer in the United States. We hope that our studies will broaden understanding of the thrombotic process in general and that we may uncover new molecular targets to treat pathological thrombosis. PUBLIC HEALTH RELEVANCE: Thrombosis is now the biggest killer in the United States. Thrombi are formed by platelets sticking together. White blood cells influence thrombi formation and their stability. Dying white cells actively release DNA producing large spider web-like structures that trap bacteria. We found that platelets bind to these webs and that such webs are present in thrombi. We propose to investigate the role of this DNA scaffold in thrombosis and the possibility of using enzymes to digest the DNA as a new anti- thrombotic approach.

描述（由申请人提供）：中性粒细胞经历细胞死亡途径，导致涂有抗菌蛋白的染色质释放，形成称为中性粒细胞胞外陷阱（NET）的网。 NET 捕获并杀死微生物。我们的初步结果表明 NET 招募并激活血小板。我们有证据表明，深静脉血栓形成的病理标本和血栓性疾病患者的血浆中存在细胞外 DNA/染色质。该应用的中心假设是，NET 提供了一个支架，与纤维蛋白一起增加血栓稳定性并促进血栓生长和微粒募集。我们认为，病理情况下 NET 的形成可能引发血栓事件，并导致脓毒症、血栓性微血管病和深静脉血栓形成等疾病。此外，我们认为消化 NET 的 DNase1 可能会调节血栓形成。我们将在体外和体内血栓形成模型的背景下分析 NET。我们将采用具有视频功能的流动室，使用来自基因工程小鼠的细胞。我们建议研究几种小鼠血栓形成模型，所有这些模型均在我们的实验室中建立，以利用先进的成像技术可视化体内 NET 的形成，并研究 NET 与血栓生长和稳定性的相关性。我们特别热衷于研究 NET 在新的深静脉血栓 (DVT) 下腔静脉狭窄模型和脓毒症小鼠模型中的作用。该提案有 2 个具体目标： 1. 研究介导血小板和微粒与 NET 相互作用的分子机制。 评估 NET 是否促进纤维蛋白生成。在这个目标中，我们建议在体外研究血小板粘附到 NET 上的分子机制，并探讨 NET 是否促进促凝微粒 (MP) 的募集和纤维蛋白沉积。 2. 研究体内 NET 的形成，并检查 NET 与脓毒症引起的血小板减少症和深静脉血栓形成的生物学相关性。 测量血栓患者样本中的 NETs 生物标志物。为此，我们建议通过活体显微镜和组织学来可视化 NET。我们建议调节 NET 的产生和循环 DNA 水平，并观察对败血症和 DVT 小鼠模型的影响。我们将研究 NET 作为血栓形成的生物标志物。血栓形成，包括深静脉血栓/肺栓塞，现在是美国最大的杀手。我们希望我们的研究能够拓宽对血栓形成过程的总体理解，并可能发现治疗病理性血栓形成的新分子靶点。 公共卫生相关性：血栓形成现在是美国最大的杀手。血栓是由血小板粘在一起形成的。白细胞影响血栓的形成及其稳定性。垂死的白细胞会主动释放DNA，产生巨大的蜘蛛网状结构来捕获细菌。我们发现血小板与这些网结合，并且这种网存在于血栓中。我们建议研究这种 DNA 支架在血栓形成中的作用以及使用酶消化 DNA 作为新的抗血栓方法的可能性。