Annexin I is stored within gelatinase granules of human neutrophil and mobilized on the cell surface upon adhesion but not phagocytosis
Autor: | Ivana Aiello, Helen C. Christian, K.G. Mugridge, Mauro Perretti, Samantha K. Wheller, John F. Morris, Roderick J. Flower, N. J. Goulding |
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Rok vydání: | 2000 |
Předmět: |
Neutrophils
Phagocytosis Cell Membrane Degranulation Cell Biology General Medicine Biology Cytoplasmic Granules Intercellular Adhesion Molecule-1 Cell biology Cell membrane Platelet Endothelial Cell Adhesion Molecule-1 medicine.anatomical_structure Annexin Gelatinases medicine Cell Adhesion Gelatinase Humans Secretion Endothelium Vascular Annexin A2 Annexin A1 |
Zdroj: | Cell biology international. 24(3) |
ISSN: | 1065-6995 |
Popis: | Annexin I, a member of the calcium- and phospholipid-binding annexin superfamily of proteins, is largely present in human neutrophils. To determine its exact intracellular distribution a combination of flow cytometry, confocal microscopy and electron microscopy analyses were performed on resting human neutrophils as well as on cells which had been activated. In resting neutrophils, annexin I was found to be present in small amounts in the nucleus, in the cytoplasm and partially also associated with the plasma membrane. The cytoplasmic pool of annexin I was predominant, and the protein was co-localized with gelatinase (marker of gelatinase granules), but not with human serum albumin or CD35 (markers of secretory vesicles), or with lysosomes. Electron microscopy showed the presence of annexin I inside the gelatinase granules. Neutrophil adhesion to monolayers of endothelial cells, but not phagocytosis of particles of opsonized zymosan, provoked an intense mobilization of annexin I, with a marked externalization on the outer leaflet of the plasma membrane. Remaining intracellular annexin I was also found in proximity of the plasma membrane. These results provide a novel mechanism for annexin I secretion from human neutrophils, which is via a degranulation event involving gelatinase granules. |
Databáze: | OpenAIRE |
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