|
|
Blood, 15 October 2007, Vol. 110, No. 8, pp. 3049-3055.
Prepublished online as a Blood First Edition Paper on July 16, 2007; DOI 10.1182/blood-2007-02-074393.
Previous Article | Next Article 
Submitted February 20, 2007
Accepted July 3, 2007
Normal erythropoiesis but severe polyposis and bleeding anemia in Smad4 deficient mice
Dejing Pan, Tibor Schomber, Christian P Kalberer, Luigi M Terracciano, Katrin Hafen, Werner Krenger, Hui Hao-Shen, Chuxia Deng, and Radek C Skoda*
Department of Research, Experimental Hematology, University Hospital Basel, Basel, Switzerland
Department of Pathology, University Hospital Basel and Department of Health Sciences, University of Molise, Campobasso, Italy
Department of Clinical-Biological Sciences, Laboratory of Pediatric Immunology, University of Basel, and Basel University Children's Hospital, Basel, Switzerland
Mammalian Genetics Section, Genetics of Development & Disease Branch, NIDDK, NIH, Bethesda, MD, United States
* Corresponding author; email: radek.skoda{at}unibas.ch.
The tumor suppressor Smad4 mediates signaling by transforming growth factor-beta (TGF- ) superfamily of ligands. Previous studies showed that several TGF- family members exert important functions in hematopoiesis. Here, we studied the role of Smad4 in adult murine hematopoiesis using the inducible Mx-Cre/loxP system. Mice with homozygous Smad4 deletion (Smad4 / ) developed severe anemia 6-8 weeks after induction (mean hemoglobin 70g/L). The anemia was not transplantable, as wild type mice reconstituted with Smad4 / bone marrow cells had normal peripheral blood counts. These mice did not develop an inflammatory disease typical for mice deficient in TGF- receptors I and II suggesting that the suppression of inflammation by TGF- is Smad4 independent. The same results were obtained when Smad4 alleles were deleted seletively in hematopoietic cells using the VavCre transgenic mice. In contrast, lethally irradiated Smad4 / mice transplanted with wild type bone marrow cells developed anemia similar to non-transplanted Smad4 / mice. Liver iron stores were decreased and blood was present in stool, indicating that the anemia was due to blood loss. Multiple polyps in stomach and colon represent a likely source of the bleeding. We conclude that Smad4 is not required for adult erythropoiesis and that anemia is solely the consequence of blood loss.

CiteULike Connotea Del.icio.us Digg Reddit Technorati What's this?
This article has been cited by other articles:

|
 |

|
 |
 
R. Tiedt, J. Coers, S. Ziegler, A. Wiestner, H. Hao-Shen, C. Bornmann, J. Schenkel, S. Karakhanova, F. J. de Sauvage, C. W. Jackson, et al.
Pronounced thrombocytosis in transgenic mice expressing reduced levels of Mpl in platelets and terminally differentiated megakaryocytes
Blood,
February 19, 2009;
113(8):
1768 - 1777.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|
|