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Blood, 15 July 2007, Vol. 110, No. 2, pp. 509-518. Prepublished online as a Blood First Edition Paper on April 2, 2007; DOI 10.1182/blood-2006-11-056465. This Article Full Text Full Text (PDF) Supplemental Appendix and Figures All Versions of this Article: blood-2006-11-056465v1 110/2/509    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Rights and Permissions Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Sathyanarayana, P. Articles by Wojchowski, D. M. Search for Related Content PubMed PubMed Citation Articles by Sathyanarayana, P. Articles by Wojchowski, D. M. Related Collections Hematopoiesis and Stem Cells Gene Expression Social Bookmarking                   What's this?  Previous Article  |  Table of Contents  |  Next Article  HEMATOPOIESIS Erythropoietin modulation of podocalyxin and a proposed erythroblast niche Pradeep Sathyanarayana1, Madhu P. Menon1, Olga Bogacheva1, Oleg Bogachev1, Knut Niss2, William S. Kapelle1, Estelle Houde1, Jing Fang1, and Don M. Wojchowski1 1 Stem and Progenitor Cell Biology Program and Center for Molecular Medicine, Maine Medical Center Research Institute, Scarborough, ME; 2 Pfizer Global Research and Development, Groton, CT Epo's erythropoietic capacity is ascribed largely to its antiapoptotic actions. In part via gene profiling of bone marrow erythroblasts, Epo is now shown to selectively down-modulate the adhesion/migration factors chemokine receptor-4 (Cxcr4) and integrin alpha-4 (Itga4) and to up-modulate growth differentiation factor-3 (Gdf3), oncostatin-M (OncoM), and podocalyxin like-1 (PODXL). For PODXL, Epo dose–dependent expression of this CD34-related sialomucin was discovered in Kit+CD71high proerythroblasts and was sustained at subsequent Kit–CD71high and Ter119+ stages. In vivo, Epo markedly induced PODXL expression in these progenitors and in marrow-resident reticulocytes. This was further associated with a rapid release of PODXL+ reticulocytes to blood. As studied in erythroblasts expressing minimal Epo receptor (EpoR) alleles, efficient PODXL induction proved dependence on an EpoR-PY343 Stat5 binding site. Moreover, in mice expressing an EpoR-HM F343 allele, compromised Epo-induced PODXL expression correlated with abnormal anucleated red cell representation in marrow. By modulating this select set of cell-surface adhesion molecules and chemokines, Epo is proposed to mobilize erythroblasts from a hypothesized stromal niche and possibly promote reticulocyte egress to blood. CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this? This article has been cited by other articles: P. Sathyanarayana, A. Dev, J. Fang, E. Houde, O. Bogacheva, O. Bogachev, M. Menon, S. Browne, A. Pradeep, C. Emerson, et al. EPO receptor circuits for primary erythroblast survival Blood, June 1, 2008; 111(11): 5390 - 5399. [Abstract] [Full Text] [PDF] F. Grebien, M. A. Kerenyi, B. Kovacic, T. Kolbe, V. Becker, H. Dolznig, K. Pfeffer, U. Klingmuller, M. Muller, H. Beug, et al. Stat5 activation enables erythropoiesis in the absence of EpoR and Jak2 Blood, May 1, 2008; 111(9): 4511 - 4522. [Abstract] [Full Text] [PDF]

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