Structural characterization of platelets and platelet microvesicles
- 103 Downloads
Platelets are blood cells without nuclei, which, in conjunction with fibrin, cause bleeding to stop (hemostasis). Cellular microvesicles are microscopic particles released into extracellular space under activation and/or apoptosis of cells of different types. Platelet microvesicles form the main population of blood circulating through microvesicles and play an important role in the reactions of hemostasis, thrombosis, and many other (patho)physiological processes. Despite the large number of studies that have been devoted to the function of platelet microvesicles, the mechanisms of their formation and structural details remain poorly understood. The ultrastructure of the initial platelets and microvesicles formed in vitro from resting cells and platelets activated by arachidonic acid, ADP, thrombin, and calcium ionophore A23187 is investigated in this study. The intracellular origin, stages of formation, structural diversity, and size of microvesicles were analyzed according to the results of transmission electron microscopy of human platelets and isolated microvesicles. It was shown that thrombin, unlike other activators, not only stimulates microvesiculation of the plasma membrane, but also causes decomposition of cells with the formation of subcellular particles that have sizes comparable with the size of the microvesicles from the outer membrane of the cells. Some of these microparticles are cellular organelles surrounded by a thin membrane. The size of isolated microvesicles ranges from 30 to 500 nm, but their size distribution depends on the nature of the activating stimulus. The obtained results contain new data on the formation of platelet microvesicles and their structural diversity, which are important for understanding of their multiple functions in health and disease.
Keywordsplatelets microvesicles platelet activation cell ultrastructure electron microscopy
open canalicular system
programmed cell death
Unable to display preview. Download preview PDF.
- Boudreau, L.H., Duchez, A.-C., Cloutier, N., Soulet, D., Martin, N., Bollinger, J., Paré, A., Rousseau, M., Naika, G.S., Lévesque, T., Laflamme, C., Marcoux, G., Lambeau, G., Farndale, R.W., Pouliot, M., HamzehCognasse, H., Cognasse, F., Garraud, O., Nigrovic, P.A., Guderley, H., Lacroix, S., Thibault, L., Semple, J.W., Gelb, M.H., and Boilard, E., Platelets release mitochondria serving as substrate for bactericidal group IIA-secreted phospholipase A2 to promote inflammation, Blood, 2014, vol. 124, pp. 2173–2183.CrossRefPubMedPubMedCentralGoogle Scholar
- Heijnen, H.F.G., Schiel, A.E., Fijnheer, R., Geuze, H.J., and Sixma, J.J., Exocytosis of multivesicular bodies and Αgranules microvesicles by surface shedding and exosomes derived from activated platelets release two types of membrane vesicles, Blood, 1999, vol. 94, pp. 3791–3799.PubMedGoogle Scholar
- James, G. and White, M.D., Exocytosis of secretory organelles from blood platelets incubated with cationic polypeptides, Am J. Pathol., 1972, vol. 69, pp. 41–54.Google Scholar
- Lacroix, R., Robert, S., Poncelet, P., Kasthuri, R.S., Key, N.S., and Dignat-George, F., Standardization of platelet-derived microparticle enumeration by flow cytometry with calibrated beads: results of the International Society on Thrombosis and Haemostasis SSC Collaborative Workshop, J. Thromb. Haemos., 2010, vol. 8, pp. 2571–2574.CrossRefGoogle Scholar
- Neumüller, J., Meisslitzer-Ruppitscha, C., Ellinger, A., Pavelkaa, M., Jungbauer, C., Renzb, R., Leitner, G., and Wagner, T., Monitoring of platelet activation in platelet concentrates using transmission electron microscopy, Transfus. Med. Hemother., 2013, vol. 40, pp. 101–107.CrossRefPubMedPubMedCentralGoogle Scholar
- Nieuwland, R., van, der, Pol, E., Gardiner, C., and Sturk, A., Platelet-derived microparticles, in Platelets, 3rd ed., Amsterdam: Academic Press Elsevier, 2013, vol. 453–467.Google Scholar
- Van der Pol, E., Hoekstra, A.G., Sturk, A., Otto, C., Van Leeuwen, T.G., and Nleuwland, R., Optical and nonoptical methods for detection and characterization of microparticles and exosomes, J. Thrombos. Haemos., 2012, vol. 8, pp. 2596–2607.Google Scholar
- Zubairov, D.M. and Zubairova, L.D., Mikrovezikuly v krovi. Funktsii i ikh rol' v tromboobrazovanii (Microvesicles in the Blood. The Functions and Their Role in Thrombus Formation), Moscow: GEOTAR-Media, 2009.Google Scholar