Department of Emergency Medicine, Carolinas Medical Center, Charlotte, NC, United States.
Thromb Res. 2012 Jul;130(1):122-8. doi: 10.1016/j.thromres.2011.09.016. Epub 2011 Oct 19.
Microparticles (MPs) are small fragments of apoptotic or activated cells that may contribute to pathological processes in cardiovascular diseases. In studies of MPs in clinical cohorts, it is unclear if observed changes in MP composition are a cause or a result of the cardiovascular disease being studied. The present studies employed a well-characterized rat model of experimental pulmonary embolism (PE) to determine if there were changes in MP characteristics as a result of pulmonary vascular occlusion.
PE was produced by infusing 25 μm polystyrene microspheres into the jugular vein of anesthetized rats. MPs were isolated by differential centrifugation of arterial blood 18 hr after PE. Proteins were separated by 1D gel electrophoresis and identified from tryptic digests by ultraperformance liquid chromatography (UPLC) coupled with tandem mass spectrometry. Statistical analysis was conducted using the Power Law Global Error Model (PLGEM). Changes in two proteins were confirmed by Western blot.
Experimental PE produced pulmonary hypertension, mild systemic hypotension, hypoxia, hypercapnia and lactic acidosis. MPs showed significant elevation in proteins involved in clotting (fibronectin precursor, fibrinogen alpha, beta and gamma and von Willebrand factor) and several macroglobulin proteins, such as alpha-2-macroglobulin precursor compared with vehicle-treated control rats. Consistent with recent observations of hemolysis in PE, haptoglobin precursor protein, a major protein of hemoglobin clearance, decreased significantly in the PE animals. Plasma d-Dimer concentrations were significantly elevated, indicating that experimental PE produced a pro-coagulant state.
These findings suggest that experimental PE produced significant, changes in MP characteristics to a prothrombotic phenotype.
微粒（MPs）是凋亡或激活细胞的小碎片，可能导致心血管疾病的病理过程。在对临床队列中 MPs 的研究中，尚不清楚 MP 组成的观察到的变化是心血管疾病研究的原因还是结果。本研究采用了一种经过充分表征的大鼠实验性肺栓塞（PE）模型，以确定肺血管阻塞是否会导致 MPs 特征发生变化。
通过将 25μm 聚苯乙烯微球注入麻醉大鼠的颈静脉来产生 PE。在 PE 后 18 小时通过差速离心从动脉血中分离 MPs。通过 1D 凝胶电泳分离蛋白质，并通过超高效液相色谱（UPLC）与串联质谱联用从胰蛋白酶消化物中鉴定蛋白质。使用幂律全局误差模型（PLGEM）进行统计分析。通过 Western blot 验证了两种蛋白质的变化。
实验性 PE 导致肺动脉高压、轻度全身低血压、缺氧、高碳酸血症和乳酸酸中毒。与接受载体治疗的对照大鼠相比， MPs 中涉及凝血的蛋白质（纤维连接蛋白前体、纤维蛋白原α、β和γ以及血管性血友病因子）和几种巨球蛋白蛋白（如α-2-巨球蛋白前体）显著升高。与最近在 PE 中观察到的溶血一致，血红蛋白清除的主要蛋白质血红蛋白前体蛋白显着减少。血浆 d-二聚体浓度显着升高，表明实验性 PE 产生了促凝状态。
这些发现表明，实验性 PE 导致 MPs 特征发生了显著变化，表现出促血栓形成表型。
