HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints/Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Akel, S. Articles by Ruscetti, F. W. Search for Related Content PubMed PubMed Citation Articles by Akel, S. Articles by Ruscetti, F. W.

Neutralization of Autocrine Transforming Growth Factor-ß in Human Cord Blood CD34⁺CD38^-Lin^- Cells Promotes Stem-Cell-Factor-Mediated Erythropoietin-Independent Early Erythroid Progenitor Development and Reduces Terminal Differentiation

^a Leukocyte Biology Section, Basic Research Laboratory, Center for Cancer Research, NCI-Frederick, Frederick, Maryland, USA;
^b Intramural Research Support Program, SAIC-Frederick, Frederick, Maryland, USA;
^c Allogeneic Transplant Program, Ireland Cancer Center, Case Western Reserve University, Cleveland, Ohio, USA

Key Words. Transforming growth factor-ß1 • Serum free • Autocrine regulation • Erythropoiesis • Anti-TGF-ß

Francis W. Ruscetti, Ph.D., Leukocyte Biology Section, Building 567, Room 254, NCI-Frederick, Frederick, Maryland 21702-1201, USA. Telephone: 301-846-1504; Fax: 301-846-7034; e-mail: Ruscettif{at}ncifcrf.gov

Transforming growth factor (TGF)-ß1 exerts autocrine and paracrine effects on hematopoiesis. Here, we have attempted to evaluate the effect of endogenous TGF-ß1 on early erythroid development from primitive human hematopoietic stem cells (HSCs) and to assess the effects of TGF-ß1 on different phases of erythropoiesis. Cord blood CD34⁺CD38^- lineage-marker-negative (Lin^-) cells were cultured in serum-free conditions using various combinations of stem cell factor (SCF), erythropoietin (Epo), and TGF-ß-neutralizing antibody. Generation of erythroid progenitors was assessed using colony assay and flow cytometry. Terminal erythroid differentiation was examined when SCF/Epo-stimulated cells were recultured in the presence of Epo with and without TGF-ß1. Anti-TGF-ß augmented the proliferation of CD34⁺CD38^-Lin^- cells (day 21) in SCF-stimulated (6.4-fold ± 1.5-fold) and SCF/Epo-stimulated (2.9-fold ± 1.2-fold) cultures. Cells stimulated by SCF/Epo underwent similar levels of erythroid differentiation with and without anti-TGF-ß. While SCF alone stimulated the production of tryptase-positive mast cells, cells stimulated by SCF/anti-TGF-ß were predominantly erythroid (CD36⁺CD14^- and glycophorin A positive). A distinct expansion of erythroid progenitors (CD34⁺CD36⁺CD14^-) with the potential to form erythroid colonies was seen, revealing early Epo-independent erythroid development. In contrast, the kinetics of erythroid progenitor generation from primitive HSCs indicate that TGF-ß1 is not inhibitory in late erythropoiesis, but it accelerated the conversion of large BFU-E into colony-forming units-erythroid. Finally, TGF-ß1 accelerated Epo-induced terminal erythroid differentiation and resulted in a greater level of enucleation (22% ± 6% versus 7% ± 3%) in serum-free conditions. Serum addition stimulated enucleation (54% ± 18%), which was lower (26% ± 14%) with anti-TGF-ß, suggesting that optimal erythroid enucleation is Epo dependent, requiring serum factors including TGF-ß1.

This article has been cited by other articles:

				S. Saha, L. Ji, J. J. de Pablo, and S. P. Palecek TGF{beta}/Activin/Nodal Pathway in Inhibition of Human Embryonic Stem Cell Differentiation by Mechanical Strain Biophys. J., May 15, 2008; 94(10): 4123 - 4133. [Abstract] [Full Text] [PDF]

				C. Leberbauer, F. Boulme, G. Unfried, J. Huber, H. Beug, and E. W. Mullner Different steroids co-regulate long-term expansion versus terminal differentiation in primary human erythroid progenitors Blood, January 1, 2005; 105(1): 85 - 94. [Abstract] [Full Text] [PDF]

				S. Uddin, J. Ah-Kang, J. Ulaszek, D. Mahmud, and A. Wickrema Differentiation stage-specific activation of p38 mitogen-activated protein kinase isoforms in primary human erythroid cells PNAS, January 6, 2004; 101(1): 147 - 152. [Abstract] [Full Text] [PDF]