Abstract |
Transfusion of allogeneic platelets is the mainstay of therapy for patients with thrombocytopenic hemorrhage. However, donated platelets can only be stored for 5 days and are maintained at room temperature, increasing the risk of bacterial growth. Developing a method to produce functional platelets in vitro would greatly advance transfusion therapy. During our studies to understand megakaryocyte development, we discovered that a Src kinase inhibitor, SU6656, induces cellular enlargement, polyploidization, and cytoplasmic fragmentation of several hematopoietic cell lines. Therefore, we tested the hypothesis that these fragments possess platelet-like activity. We studied a megakaryocytic cell-line, UT-7/TPO, and immature human primary megakaryocytes. After 6 days in the presence of thrombopoietin and SU6656, the majority of cells became polyploid and started shedding platelet-like fragments. These fragments were tested for aggregation and analyzed by electron microscopy. The platelet-like fragments did not undergo spontaneous activation but did show rapid and sustained aggregation in response to each of the standard agonists collagen, arachidonic acid, adenosine diphosphate, and epinephrine. Platelet-like fragments generated in SU6656 had higher amplitude and more prolonged aggregation in each of three experiments. Primary progenitors developed demarcation membranes within 72 h and evidence of dense granules and platelet-like fragments after 6 days. These cell fragments demonstrated properties consistent with platelet aggregation in response to multiple agonists without spontaneous aggregation. These studies provide evidence that SU6656 promotes megakaryocytic differentiation and thrombopoiesis in vitro.
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Authors | Manish J Gandhi, Jonathan G Drachman, Jo-Anna Reems, David Thorning, Brian J Lannutti |
Journal | Blood cells, molecules & diseases
(Blood Cells Mol Dis)
2005 Jul-Aug
Vol. 35
Issue 1
Pg. 70-3
ISSN: 1079-9796 [Print] United States |
PMID | 15923131
(Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Indoles
- SU 6656
- Sulfonamides
- Thrombopoietin
- src-Family Kinases
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Topics |
- Blood Platelets
(cytology, physiology)
- Cell Differentiation
(drug effects)
- Cell Line
- Hematopoietic Stem Cells
(cytology)
- Humans
- Indoles
(pharmacology)
- Megakaryocytes
(cytology)
- Methods
- Microscopy, Electron
- Platelet Adhesiveness
- Sulfonamides
(pharmacology)
- Thrombopoiesis
(drug effects)
- Thrombopoietin
(pharmacology)
- src-Family Kinases
(antagonists & inhibitors)
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