Cryogenic Transmission Electron Microscopy Nanostructural Study of Shed Microparticles
Cryogenic Transmission Electron Microscopy Nanostructural Study of Shed Microparticles
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DOI：
10.1371/journal.pone.0083680
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发表时间：
2013-12-26
期刊：
影响因子：
3.7
通讯作者：
Aharon, Anat
中科院分区：
文献类型：
--
作者：
Issman, Liron;Brenner, Benjamin;Aharon, Anat
微颗粒（MPs）是正常和病理细胞由于刺激或凋亡而脱落的亚微米级膜泡（100- 1000nm）。MPs可以在健康人的外周血循环中发现，而在怀孕和多种疾病中发现浓度升高。此外，MPs还参与生理过程，如凝血、炎症和血管生成。由于它们的临床特性很重要，我们开发了一种基于纳米成像的新方法，为MPs的纳米结构、组成和功能提供了重要的新数据。我们是第一个通过直接成像低温透射电子显微镜（cro - tem）表征从不同细胞类型和刺激程序分离的MP系统的接近天然纳米结构的人之一。我们发现我们所研究的MP系统之间没有主要差异，因为大多数颗粒是球形的，直径从200到400纳米。然而，每个MP群体是非常异质的，表现出不同的形态。我们通过低温透射电镜研究了用于分离和储存MPs的标准技术的影响，发现无论是用于分离目的的MPs的高g离心，还是用于储存的慢速冷冻到-80℃都会引入形态学伪影，这些伪影会影响MP的纳米结构，从而影响这些颗粒作为未来诊断工具的效率。
Microparticles (MPs) are sub-micron membrane vesicles (100-1000 nm) shed from normal and pathologic cells due to stimulation or apoptosis. MPs can be found in the peripheral blood circulation of healthy individuals, whereas elevated concentrations are found in pregnancy and in a variety of diseases. Also, MPs participate in physiological processes, e. g., coagulation, inflammation, and angiogenesis. Since their clinical properties are important, we have developed a new methodology based on nano-imaging that provides significant new data on MPs nanostructure, their composition and function. We are among the first to characterize by direct-imaging cryogenic transmitting electron microscopy (cryo-TEM) the near-to-native nanostructure of MP systems isolated from different cell types and stimulation procedures. We found that there are no major differences between the MP systems we have studied, as most particles were spherical, with diameters from 200 to 400 nm. However, each MP population is very heterogeneous, showing diverse morphologies. We investigated by cryo-TEM the effects of standard techniques used to isolate and store MPs, and found that either high-g centrifugation of MPs for isolation purposes, or slow freezing to -80 degrees C for storage introduce morphological artifacts, which can influence MP nanostructure, and thus affect the efficiency of these particles as future diagnostic tools.