Platelet contraction cytometry as a novel assay of platelet function

血小板收缩细胞术作为血小板功能的新型检测方法

• 批准号: 9923656
• 负责人: David Richard Myers
• 金额: $ 23.4万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9923656
• 关键词: Accounting; Architecture; Area; Award; Basic Science; Behavior; Biochemical; Biological Assay; Biological Markers; Biophysics; Blood Coagulation Disorders; Blood Platelets; Blood coagulation; Categories; Cells; Clinical; Coagulation Process; Collagen; Computer Models; Contracts; Contusions; Cues; Cytometry; Data; Devices; Diagnostic; Disease; Erythrocytes; Exhibits; Experimental Hematology; Fibrin; Fibrin fragment D; Fibrinogen; Foundations; Functional disorder; Funding; Hematological Disease; Hematology; Hemorrhage; Hemostatic function; Immune; Impairment; Individual; Knowledge; Lead; Ligands; Link; Malignant Neoplasms; Measurement; Measures; Mechanics; Mediating; Modeling; Morbidity - disease rate; Muscle; National Institute of Biomedical Imaging and Bioengineering; P-Selectin; PAC1 phosphatase; Patients; Phenotype; Phosphatidylserines; Physiological; Platelet Activation; Platelet Count measurement; Platelet Function Tests; Platelet aggregation; Polymers; Protocols documentation; Research; Research Personnel; Sampling; Sepsis; Signal Pathway; Speed; Symptoms; System; Testing; Thrombocytopenia; Thrombocytopenic Purpura; Thrombosis; Translating; base; clinical practice; clinically relevant; cohort; drug discovery; healthy volunteer; high risk; in silico; individual patient; insight; mechanical properties; mortality; novel; novel therapeutics; platelet function; platelet phenotype; predictive modeling; response; shear stress; stem; tool

PROJECT SUMMARY/ABSTRACT Despite accounting for significant mortality and morbidity in many disease states1–3, including primary hematologic disorders, cancer4, and sepsis5,6, our knowledge of bleeding and thrombotic complications remains far from complete due to a lack of tools. During blood clot formation, platelets undergo muscle-like contraction with nascent fibrin polymers to dynamically contract and stabilize the clot to stem hemorrhage. However, how platelets transduce microenvironmental cues to mediate contraction and alter clot mechanics remains largely unknown yet clinically relevant, as overly softened and stiffened clots are associated with bleeding7 and thrombotic disorders8, respectively. Bulk assays are insufficient for these studies as individual platelets exhibit highly variable behavior that depends on the local clotting biochemical concentration and mechanical stiffness. Here, a newly developed high-throughput platelet contraction cytometer now enables parallel measurements of single platelet contraction forces in varied microenvironments. In addition to enabling detailed studies of individual platelet behavior, our preliminary data from patients suggests that the platelet contraction cytometer may represent an entirely new category of diagnostic that identifies a link between aberrant platelet contractile force and bleeding. As between 30-60% of patients with bleeding remain undiagnosed, this may represent a significant and impactful avenue to better understand and identify aberrant hemostasis. We found that highly contractile platelet subpopulations present in healthy controls are conspicuously absent in a small sample patients with undiagnosed bleeding disorders. Similarly, we found correlations with active bruising and platelet contractile forces in the context of patients with immune thrombocytopenia (ITP). Moreover, platelet contraction cytometery appears to be independent of the known markers of platelet activation (phosphatidylserine, P-selectin, and PAC-1). The research objective of this NIBIB Trailblazer Award for New and Early Stage Investigators (R21) is to investigate a novel hypothesis: that the contractile force of platelets independently predicts bleeding. We will first define the healthy platelet contractile response to both collagen and fibrin(ogen) over the range of physiological stiffnesses present in a clot. We hypothesize that these various ligands will elicit different force responses from platelets, and we will analyze these responses and look for microenvironmental conditions that synergize to produce a highly contractile platelet phenotype, which we have previously found to have diagnostic potential. In addition, we will analyze the platelet contractile forces from: healthy volunteers, undiagnosed patients with symptomatic bleeding, and patients with immune thrombocytopenic purpura to test the hypothesis that impaired platelet contractile force will correlate with bleeding symptoms.

项目摘要/摘要 尽管在许多疾病状态下都考虑了死亡率和发病率的显着性死亡率1-3，包括主要的死亡率和发病率 血液学疾病，癌症4和sepsis5,6，我们对出血和血栓形成并发症的了解 由于缺乏工具，因此尚未完成。在血块形成期间，血小板会经历肌肉样 与新生纤维蛋白聚合物的收缩，动态收缩并稳定凝块以茎出血。 但是，血小板如何翻译微环境提示以介导收缩和改变凝块力学 由于过度软化和僵硬的布与 分别出血7和血栓性疾病8。作为个人研究，批量测定不足 血小板暴露了高度可变的行为，取决于局部凝血的生化浓度和 机械刚度。在这里，新开发的高通量血小板收缩细胞仪现在可以启用 各种微环境中单个血小板收缩力的平行测量。 除了启用对单个血小板行为的详细研究，我们的初步数据来自患者 表明血小板收缩细胞仪可能代表一个全新的诊断类别 确定异常血小板收缩力与出血之间的联系。在30-60％的患者中 出血仍然没有诊断，这可能代表了更好地理解和 识别异常止血。我们发现健康中存在高度收缩的血小板亚群 在未诊断出出血疾病的小样本患者中，对照组明显不存在。相似地， 我们发现在免疫患者的背景下，与主动瘀伤和血小板收缩力相关 血小板减少症（ITP）。此外，血小板收缩细胞术似乎与已知的 血小板激活的标记（磷脂酰丝氨酸，P-选择素和PAC-1）。 这项尼比布开拓者的研究目标是新的和早期调查人员（R21）的研究目标是 研究一个新的假设：血小板的收缩力独立预测出血。我们将 首先在范围内定义对胶原蛋白和纤维蛋白（OGEN）的健康血小板收缩反应 凝块中存在物理刚度。我们假设这些各种配体将引起不同的力 血小板的反应，我们将分析这些反应，并寻找微环境条件 协同作用以产生高度转换器血小板表型，我们以前发现它具有 诊断潜力。此外，我们将分析来自：健康志愿者的血小板收缩力， 有症状出血的未诊断患者和免疫血小板减少紫癜的患者进行测试 损害血小板收缩力的假设将与出血符号相关。