Stem Cells http://www.stemcellsportal.com/
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Reprints/Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Cowley, S. A.
Right arrow Articles by Avraham, H.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Cowley, S. A.
Right arrow Articles by Avraham, H.

International Journal of Cell Cloning, Vol 10, 223-231, Copyright © 1992 by AlphaMed Press

ORIGINAL ARTICLES

Effects of transforming growth factor beta on megakaryocytic cell fusion and endomitosis

SA Cowley, JE Groopman and H Avraham
Department of Medicine, New England Deaconess Hospital, Harvard Medical School, Boston, MA 02215.

Transforming growth factor beta (TGF-beta) is a cytokine secreted by megakaryocytes and platelets which inhibits the proliferation of megakaryocyte progenitors in vitro. We have studied the effects of TGF- beta on more mature megakaryocytes, using cell lines CMK, DAMI, and CHRF as well as isolated human marrow megakaryocytes as models. Proliferation of these megakaryocytic cell lines was inhibited by TGF- beta 1 at concentrations of 10-100 ng/ml. Although these cell lines secreted small amounts of TGF-beta (up to 100 pg/ml), it was predominantly in an inactive form. Upon induction with 12-phorbol 13- myristate acetate (PMA), they secreted greater amounts of TGF-beta (500- 1250 pg/ml), most of which was still inactive in a bioassay. Addition of exogenous active TGF-beta 1 had no effect on ploidy of unstimulated megakaryocytic cell lines or on [3H]thymidine incorporation of isolated human marrow megakaryocytes. Following PMA induction, exogenous TGF- beta 1 had a significant inhibitory effect on ploidy in DAMI cells but not CMK or CHRF cells, suggesting that the phenomenon is restricted to DAMI cells. Because certain cell lines may fuse in vitro, and phorbol esters can promote this phenomenon, we investigated the possibility that fusion was contributing to the increase in ploidy in megakaryocytic cells. Unstimulated megakaryocytic cells did not show spontaneous fusion; when PMA was added to the cultures, fusion was markedly increased, particularly in DAMI cells. These results demonstrate that in vitro fusion accounts for a proportion of the apparent increase in DNA content of megakaryocytic cell lines upon induction with PMA.(ABSTRACT TRUNCATED AT 250 WORDS)


This article has been cited by other articles:


Home page
 Stem CellsHome page
L. Catani, M. Amabile, S. Luatti, L. Valdre, N. Vianelli, G. Martinelli, and S. Tura
Interleukin-4 Downregulates Nuclear Factor-Erythroid 2 (NF-E2) Expression in Primary Megakaryocytes and in Megakaryoblastic Cell Lines
Stem Cells, July 1, 2001; 19(4): 339 - 347.
[Abstract] [Full Text] [PDF]

Home page
 BloodHome page
N. O. Fortunel, A. Hatzfeld, and J. A. Hatzfeld
Transforming growth factor-beta : pleiotropic role in the regulation of hematopoiesis
Blood, September 15, 2000; 96(6): 2022 - 2036.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
D. Hiregowdara, H. Avraham, Y. Fu, R. London, and S. Avraham
Tyrosine Phosphorylation of the Related Adhesion Focal Tyrosine Kinase in Megakaryocytes upon Stem Cell Factor and Phorbol Myristate Acetate Stimulation and Its Association with Paxillin
J. Biol. Chem., April 18, 1997; 272(16): 10804 - 10810.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
STEM CELLS THE ONCOLOGIST CME ALPHAMED PRESS JOURNALS
http://www.peprotech.com/
Copyright © 1992 by AlphaMed Press.