Alpha-granule pool of glycoprotein IIb-IIIa in normal and pathologic platelets and megakaryocytes
| Autor: | Em, Cramer, Gf, Savidge, Vainchenker W, Mc, Berndt, Dominique Pidard, Jp, Caen, Jm, Massé, Breton-Gorius J |
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| Rok vydání: | 1990 |
| Předmět: |
Blood Platelets
Immunology Thrombin Fibrinogen Platelet Membrane Glycoproteins Syndrome Cell Biology Hematology Cytoplasmic Granules Immunohistochemistry Biochemistry Cell Degranulation Microscopy Electron Antibody Specificity Humans Blood Platelet Disorders Megakaryocytes Cells Cultured Thrombasthenia |
| Zdroj: | Europe PubMed Central |
| ISSN: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood.v75.6.1220.bloodjournal7561220 |
| Popis: | Using an immunogold staining technique and electron microscopy, we investigated the localization of the alpha-granule pool of glycoprotein (GP) IIb-IIIa in normal platelets and maturing megakaryocytes (MK), in pathologic platelets from a patient with type I Glanzmann's thrombasthenia (GT), and from three patients with the gray platelet syndrome (GPS). In normal resting platelets, GPIIb-IIIa was observed on the plasmatic side of the plasma membrane, the open canicular system (OCS) membranes, and along the internal face of the alpha-granule membrane. This location was found with three monospecific polyclonal antibodies: one anti-GPIIb-IIIa antibody, the second specific for GPIIb, and the third specific for GPIIIa. After thrombin stimulation, the alpha-granule labeling disappeared whereas membrane labeling increased. Platelets from GT did not display labeling on plasma membranes, OCS membranes, or alpha-granule membranes. Platelets from the three patients with GPS displayed intense labeling of the plasma membrane and the OCS membrane, as well as the abnormal small alpha- granules and along the inside of large vacuoles (which contain the granule membrane protein [GMP]-140). In cultured immature MK from normal progenitors, both peptide components of GPIIb-IIIa appeared in the Golgi saccules and vesicles, and in the small precursors of alpha- granules, labeling both their membranes and their matrix. It was then observed only on the membrane of the mature MK alpha-granules, although labeling was less consistent than on the platelet granules. The MK plasma membrane and demarcation membrane system also displayed GPIIb- IIIa labeling. In conclusion, this study demonstrates that GPIIb-IIIa is present on the internal face of the alpha-granule membranes of platelets (where it appears early during MK maturation) as well as in the abnormal alpha-granules of gray platelets; it is absent from GT type I platelets. |
| Databáze: | OpenAIRE |
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