JCB logo
amgmicro.com
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
An addendum to this article has been published: Eshghi et al., J. Cell Biol. 181 (2) 395
Published online
doi:10.1083/jcb.200702080
The Journal of Cell Biology, Vol. 177, No. 5, 871-880
The Rockefeller University Press, 0021-9525 $30.00
© Eshghi et al.
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 2178K)
Right arrow PPT slides of all figures
Right arrow Addendum (v181,p395)
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Eshghi, S.
Right arrow Articles by Lodish, H. F.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Eshghi, S.
Right arrow Articles by Lodish, H. F.
Right arrowPubmed/NCBI databases
*Substance via MeSH
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

Article

{alpha}4ß1 integrin and erythropoietin mediate temporally distinct steps in erythropoiesis: integrins in red cell development



Shawdee Eshghi1,2,6, Mariette G. Vogelezang3, Richard O. Hynes3,4, Linda G. Griffith1,2,5, and Harvey F. Lodish1,2,4,6

1 Division of Biological Engineering, 2 Biotechnology Process Engineering Center, 3 Center for Cancer Research, 4 Department of Biology, and 5 Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
6 Whitehead Institute for Biomedical Research, Cambridge, MA 02142

Correspondence to Harvey F. Lodish: lodish{at}wi.mit.edu

Erythropoietin (Epo) is essential for the terminal proliferation and differentiation of erythroid progenitor cells. Fibronectin is an important part of the erythroid niche, but its precise role in erythropoiesis is unknown. By culturing fetal liver erythroid progenitors, we show that fibronectin and Epo regulate erythroid proliferation in temporally distinct steps: an early Epo-dependent phase is followed by a fibronectin-dependent phase. In each phase, Epo and fibronectin promote expansion by preventing apoptosis partly through bcl-xL. We show that {alpha}4, {alpha}5, and ß1 are the principal integrins expressed on erythroid progenitors; their down-regulation during erythropoiesis parallels the loss of cell adhesion to fibronectin. Culturing erythroid progenitors on recombinant fibronectin fragments revealed that only substrates that engage {alpha}4ß1-integrin support normal proliferation. Collectively, these data suggest a two-phase model for growth factor and extracellular matrix regulation of erythropoiesis, with an early Epo-dependent, integrin-independent phase followed by an Epo-independent, {alpha}4ß1-integrin–dependent phase.

Abbreviations used in this paper: BFU-E, burst-forming unit–erythroid; CFU-E, colony-forming unit–erythroid; Epo, erythropoietin; FAK, focal adhesion kinase.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents