单核细胞和血小板衍生微粒对凝血酶生成、纤维蛋白形成和稳定性的差异贡献。
Differential contributions of monocyte- and platelet-derived microparticles towards thrombin generation and fibrin formation and stability.
机构信息
Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599-7525, USA.
出版信息
J Thromb Haemost. 2011 Nov;9(11):2251-61. doi: 10.1111/j.1538-7836.2011.04488.x.
BACKGROUND
Microparticles (MPs) are sub-micron vesicles shed by activated or apoptotic cells, including platelets and monocytes. Increased circulating MPs are associated with thrombosis; however, their role in thrombogenesis is poorly understood.
OBJECTIVE
To determine how MPs promote thrombin generation and modulate fibrin density and stability.
METHODS
Platelets and monocytes were isolated from healthy donors. Platelets were stimulated with calcium ionophore, thrombin receptor agonist peptide (TRAP) or TRAP/convulxin. Monocytes and human monocytic THP-1 cells were stimulated with lipopolysaccharide (LPS). MPs were isolated, washed by high-speed centrifugation and assessed using the following: transmission electron microscopy (TEM), Nanoparticle Tracking Analysis (NTA), flow cytometry, tissue factor (TF) activity, prothrombinase activity, thrombin generation, and clot formation, density and stability.
RESULTS
MPs from monocytes (M-MPs) and platelets (PMPs) had similar shapes and diameters (100-300 nm). M-MPs had TF activity (16.7 ± 2.4 pm TF per 10(6) MP), supported prothrombinase activity and triggered shorter thrombin generation lag times than buffer controls (5.4 ± 0.5 vs. 84.2 ± 4.8 min, respectively). Compared with controls, M-MPs supported faster fibrin formation (0.24 ± 0.24 vs. 76.7 ± 15.1 mOD min(-1) , respectively), 38% higher fibrin network density and higher clot stability (3.8-fold higher turbidity in the presence of tissue plasminogen activator). In contrast, PMPs did not have TF activity and supported 2.8-fold lower prothrombinase activity than M-MPs. PMPs supported contact-dependent thrombin generation, but did not independently increase fibrin network density or stability. Interestingly, PMPs increased rates of thrombin generation and fibrin formation (1.7- and 1.3-fold, respectively) when mixed with THP-1-derived MPs.
CONCLUSION
MPs from platelets and monocytes differentially modulate clot formation, structure and stability, suggesting unique contributions to thrombosis.
背景
微粒（MPs）是由激活或凋亡细胞（包括血小板和单核细胞）释放的亚微米囊泡。循环中 MPs 的增加与血栓形成有关；然而，它们在血栓形成中的作用知之甚少。
目的
确定 MPs 如何促进凝血酶生成并调节纤维蛋白密度和稳定性。
方法
从健康供体中分离血小板和单核细胞。用钙离子载体、凝血酶受体激动肽（TRAP）或 TRAP/康普辛刺激血小板。用脂多糖（LPS）刺激单核细胞和人单核细胞 THP-1 细胞。分离 MPs，通过高速离心洗涤，并使用以下方法进行评估：透射电子显微镜（TEM）、纳米颗粒跟踪分析（NTA）、流式细胞术、组织因子（TF）活性、凝血酶原酶活性、凝血酶生成和凝块形成、密度和稳定性。
结果
单核细胞（M-MPs）和血小板（PMPs）来源的 MPs 具有相似的形状和直径（100-300nm）。M-MPs 具有 TF 活性（每 10^6 MPs 中有 16.7±2.4pm TF），支持凝血酶原酶活性，并比缓冲对照物触发更短的凝血酶生成滞后时间（分别为 5.4±0.5 和 84.2±4.8min）。与对照组相比，M-MPs 支持更快的纤维蛋白形成（分别为 0.24±0.24 和 76.7±15.1mOD min^-1），纤维蛋白网络密度高 38%，凝块稳定性高（存在组织纤溶酶原激活物时浊度增加 3.8 倍）。相比之下，PMPs 没有 TF 活性，支持的凝血酶原酶活性比 M-MPs 低 2.8 倍。PMPs 支持接触依赖性凝血酶生成，但不能独立增加纤维蛋白网络密度或稳定性。有趣的是，当与 THP-1 衍生的 MPs 混合时，PMPs 会增加凝血酶生成和纤维蛋白形成的速度（分别为 1.7-和 1.3 倍）。
结论
血小板和单核细胞来源的 MPs 可差异调节血栓形成、结构和稳定性，提示其对血栓形成有独特的贡献。
Zotero 插件