Platelet receptor expression on three human megakaryoblast-like cell lines
Vittet, D.; Mathieu, M.N.; Launay, J.M.; Chevillard, C.
Experimental Hematology 20(9): 1129-1134
1992
ISSN/ISBN: 0301-472X PMID: 1334843 Document Number: 392721
Platelets, the progeny of bone marrow megakaryocytes, are nonnucleated cells; many platelet proteins, including platelet membrane receptors, are believed to be derived from megakaryocytes. Several hematopoietic cell lines that exhibit megakaryocytic characteristics have been established as models for the study of megakaryocyte biology. We report here the screening of platelet receptor expression, in terms of functional coupling with the formation of two second messengers calcium and cAMP, in three cell lines exhibiting megakaryoblastic properties: HEL, MEG-01, and DAMI. We show that all these cell lines reported to thrombin, ADP, epinephrine, and prostaglandin E-1 (PGE-1). However, transmembrane signaling pathways appear partly different from those present in mature platelets, because the action of thrombin was found to be positively coupled with the cAMP pathway, in addition to that of calcium, and because PGE-1, which interacts with the cAMP pathway, also raises intracellular calcium levels in the three cell lines studied. Furthermore, an endothelin-1-induced increase in intracellular calcium level was observed in MEG-01 cells, strongly suggesting that expression of endothelin receptors on platelet precursors cells, whereas the presence of such receptors is controversial on platelets. These cell lines should prove useful in further studies of the expression and molecular pharmacology of platelet receptors on platelet precursor cells, as well as for the investigation of functional roles for platelet receptors on megakaryoblastic cells.