UTSUGISAWA Taiju
   Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine
   Position   Assistant Professor
Article types Original article
Language English
Peer review Peer reviewed
Title A road map toward defining the role of Smad signaling in hematopoietic stem cells.
Journal Formal name:Stem cells (Dayton, Ohio)
Abbreviation:Stem Cells
ISSN code:10665099/10665099
Domestic / ForeginForegin
Volume, Issue, Page 24(4),pp.1128-36
Author and coauthor Utsugisawa Taiju, Moody Jennifer L, Aspling Marie, Nilsson Eva, Carlsson Leif, Karlsson Stefan
Authorship Lead author
Publication date 2006/04
Summary The transforming growth factor-beta (TGF-beta) superfamily encompasses the ligands and receptors for TGF-beta, bone morphogenic proteins (BMPs), and Activins. Cellular response to ligand is context-dependent and may be controlled by specificity and/or redundancy of expression of these superfamily members. Several pathways within this family have been implicated in the proliferation, differentiation, and renewal of hematopoietic stem cells (HSCs); however, their roles and redundancies at the molecular level are poorly understood in the rare HSC. Here we have characterized the expression of TGF-beta superfamily ligands, receptors, and Smads in murine HSCs and in the Lhx2-hematopoietic progenitor cell (Lhx2-HPC) line. We demonstrate a remarkable likeness between these two cell types with regard to expression of the majority of receptors and Smads necessary for the transduction of signals from TGF-beta, BMP, and Activin. We have also evaluated the response of these two cell types to various ligands in proliferation assays. In this regard, primary cells and the Lhx2-HPC line behave similarly, revealing a suppressive effect of Activin-A that is similar to that of TGF-beta in bulk cultures and no effect of BMP-4 on proliferation. Signaling studies that verify the phosphorylation of Smad2 (Activin and TGF-beta) and Smad1/5 (BMP) confirm cytosolic responses to these ligands. In addition to providing a thorough characterization of TGF-beta superfamily expression in HSCs, our results define the Lhx2-HPC line as an appropriate model for molecular characterization of Smad signaling.
DOI 10.1634/stemcells.2005-0263
PMID 16357343