Thromb Haemost 1998; 80(06): 968-975
DOI: 10.1055/s-0037-1615397
Letters to the Editor
Schattauer GmbH

The Effects of MPL-Ligand, Interleukin-6 and Interleukin-11 on Megakaryocyte and Platelet Alpha-granule Proteins

Authors

  • Claire S. Philipp

    1   UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey
  • Jill Remmler

    1   UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey
  • Dorothea Zucker-Franklin

    2   New York University Medical School, New York, New York, USA
Further Information

Publication History

Received 13 February 1998

Accepted after resubmission 02 September 1998

Publication Date:
07 December 2017 (online)

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Summary

Thrombopoietin (Mpl ligand), interleukin-6 (IL-6), and interleukin-11 (IL-11) differ in their effects on megakaryocyte maturation and development. In the present study, the impact of these thrombocytopoietic cytokines on biochemical and structural granule and membrane components was examined. Western blotting was performed on equivalent amounts of isolated megakaryocyte or platelet protein and the relative intensities of the enhanced chemiluminescent-visualized bands were quantitated by densitometry. Megakaryocyte growth and development factor (MGDF), a recombinant thrombopoietin-related molecule, significantly increased megakaryocyte fibronectin (72%), thrombospondin (55%), von Willebrand factor (28%) and p-selectin (CD62p) (37%) when compared to equivalent amounts of protein from saline-treated controls (p < 0.01). Megakaryocyte fibrinogen was not increased. Ultrastructurally, there was a marked increase in ribosomes and rough endoplasmic reticulum even in mature-appearing megakaryocytes. Platelets from MGDF-treated mice showed small increases in fibronectin (8%), and CD62p (18%), but did not show increases in other measured α-granule proteins. Neither IL-6 nor IL-11 increased megakaryocyte or platelet α-granule proteins over levels observed in saline controls. IL-11 treated megakaryocytes, while also exhibiting an increase in ribosomes, were characterized by prominent cytoplasmic fragmentation. The study demonstrates the impact of Mpl ligand in increasing synthesized megakaryocyte α-granule proteins and of IL-11 in promoting megakaryocyte fragmentation.