A novel role for PECAM-1 in megakaryocytokinesis and recovery of platelet counts in thrombocytopenic mice
| Autor: | Majd B. Protty, Caroline Pendaries, Ewan A. Ross, Christopher D. Buckley, Mark K. Larson, Tarvinder S. Dhanjal, Steve P. Watson |
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| Rok vydání: | 2007 |
| Předmět: |
Receptors
CXCR4 medicine.medical_specialty Chemokine Stromal cell Immunology Integrin Biochemistry Mice Cell Movement Internal medicine medicine Animals Humans Platelet Thrombopoiesis Cells Cultured Cytokinesis Mice Knockout Hematology biology Platelet Count Cell adhesion molecule Cell Biology Thrombocytopenia Hematopoiesis Cell biology Mice Inbred C57BL Platelet Endothelial Cell Adhesion Molecule-1 medicine.anatomical_structure biology.protein Bone marrow Megakaryocytes |
| Zdroj: | Blood. 109:4237-4244 |
| ISSN: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood-2006-10-050740 |
| Popis: | During thrombopoiesis, maturing megakaryocytes (MKs) migrate within the complex bone marrow stromal microenvironment from the proliferative osteoblastic niche to the capillary-rich vascular niche where proplatelet formation and platelet release occurs. This physiologic process involves proliferation, differentiation, migration, and maturation of MKs before platelet production occurs. In this study, we report a role for the glycoprotein PECAM-1 in thrombopoiesis. We show that following induced thrombocytopenia, recovery of the peripheral platelet count is impaired in PECAM-1–deficient mice. Whereas MK maturation, proplatelet formation, and platelet production under in vitro conditions were unaffected, we identified a migration defect in PECAM-1–deficient MKs in response to a gradient of stromal cell–derived factor 1 (SDF1), a major chemokine regulating MK migration within the bone marrow. This defect could be explained by defective PECAM-1−/− MK polarization of the SDF1 receptor CXCR4 and an increase in adhesion to immobilized bone marrow matrix proteins that can be explained by an increase in integrin activation. The defect of migration and polarization was confirmed in vivo with demonstration of altered spatial localization of MKs within the bone marrow in PECAM-1–deficient mice, following immune-induced thrombocytopenia. This study identifies a novel role for PECAM-1 in regulating MK migration and thrombopoiesis. |
| Databáze: | OpenAIRE |
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