Abstract
The redistribution of platelet constituents during activation is essential for their physiological function of maintaining hemostasis. We report here about real time investigations of the activation of native human platelets under physiological conditions from the initial formation of filopodia to the fully spread form by atomic force microscopy. We followed the trafficking of granules and their interaction with the plasma membrane within single cells. Our results show movement of certain granula towards the lamellipodia. Analysis of this rearrangement and the subsequent enlargement of the platelet surface reveals details of the membrane spreading process. Images of living cells are presented that show the distribution of cytoskeletal components and membrane-bound filaments at a resolution of better than 50 nm. The local minimum forces between the tip and the platelets were estimated to be smaller than 60 pN. A model for the elastic contributions of the glycocalix to the tip/membrane interaction was developed using the theory of grafted polymers.
Full text
PDF






Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Allen R. D., Zacharski L. R., Widirstky S. T., Rosenstein R., Zaitlin L. M., Burgess D. R. Transformation and motility of human platelets: details of the shape change and release reaction observed by optical and electron microscopy. J Cell Biol. 1979 Oct;83(1):126–142. doi: 10.1083/jcb.83.1.126. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Behnke O., Bray D. Surface movements during the spreading of blood platelets. Eur J Cell Biol. 1988 Jun;46(2):207–216. [PubMed] [Google Scholar]
- Evans E. New physical concepts for cell amoeboid motion. Biophys J. 1993 Apr;64(4):1306–1322. doi: 10.1016/S0006-3495(93)81497-8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fritz M., Radmacher M., Gaub H. E. In vitro activation of human platelets triggered and probed by atomic force microscopy. Exp Cell Res. 1993 Mar;205(1):187–190. doi: 10.1006/excr.1993.1074. [DOI] [PubMed] [Google Scholar]
- Hartwig J. H., DeSisto M. The cytoskeleton of the resting human blood platelet: structure of the membrane skeleton and its attachment to actin filaments. J Cell Biol. 1991 Feb;112(3):407–425. doi: 10.1083/jcb.112.3.407. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hartwig J. H. Mechanisms of actin rearrangements mediating platelet activation. J Cell Biol. 1992 Sep;118(6):1421–1442. doi: 10.1083/jcb.118.6.1421. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Henderson E., Haydon P. G., Sakaguchi D. S. Actin filament dynamics in living glial cells imaged by atomic force microscopy. Science. 1992 Sep 25;257(5078):1944–1946. doi: 10.1126/science.1411511. [DOI] [PubMed] [Google Scholar]
- Häberle W., Hörber J. K., Ohnesorge F., Smith D. P., Binnig G. In situ investigations of single living cells infected by viruses. Ultramicroscopy. 1992 Jul;42-44(Pt B):1161–1167. doi: 10.1016/0304-3991(92)90418-j. [DOI] [PubMed] [Google Scholar]
- Loftus J. C., Choate J., Albrecht R. M. Platelet activation and cytoskeletal reorganization: high voltage electron microscopic examination of intact and Triton-extracted whole mounts. J Cell Biol. 1984 Jun;98(6):2019–2025. doi: 10.1083/jcb.98.6.2019. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Morgenstern E., Korell U., Richter J. Platelets and fibrin strands during clot retraction. Thromb Res. 1984 Mar 15;33(6):617–623. doi: 10.1016/0049-3848(84)90116-6. [DOI] [PubMed] [Google Scholar]
- Morgenstern E., Neumann K., Patscheke H. The exocytosis of human blood platelets. A fast freezing and freeze-substitution analysis. Eur J Cell Biol. 1987 Apr;43(2):273–282. [PubMed] [Google Scholar]
- Nachmias V. T. Cytoskeleton of human platelets at rest and after spreading. J Cell Biol. 1980 Sep;86(3):795–802. doi: 10.1083/jcb.86.3.795. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Radmacher M., Tillamnn R. W., Fritz M., Gaub H. E. From molecules to cells: imaging soft samples with the atomic force microscope. Science. 1992 Sep 25;257(5078):1900–1905. doi: 10.1126/science.1411505. [DOI] [PubMed] [Google Scholar]
- Sixma J. J., van den Berg A., Jockusch B. M., Hartwig J. Immunoelectron microscopic localization of actin, alpha-actinin, actin-binding protein and myosin in resting and activated human blood platelets. Eur J Cell Biol. 1989 Apr;48(2):271–281. [PubMed] [Google Scholar]
- Stenberg P. E., Shuman M. A., Levine S. P., Bainton D. F. Redistribution of alpha-granules and their contents in thrombin-stimulated platelets. J Cell Biol. 1984 Feb;98(2):748–760. doi: 10.1083/jcb.98.2.748. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tao N. J., Lindsay S. M., Lees S. Measuring the microelastic properties of biological material. Biophys J. 1992 Oct;63(4):1165–1169. doi: 10.1016/S0006-3495(92)81692-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- White J. G., Krumwiede M. Further studies of the secretory pathway in thrombin-stimulated human platelets. Blood. 1987 Apr;69(4):1196–1203. [PubMed] [Google Scholar]
- White J. G. The secretory pathway of bovine platelets. Blood. 1987 Mar;69(3):878–885. [PubMed] [Google Scholar]





