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Inhibition of thrombopoietin/Mpl signaling in adult hematopoiesis identifies new candidates for hematopoietic stem cell maintenance
- Source :
- PLoS ONE, Vol 10, Iss 7, p e0131866 (2015), PLoS ONE
- Publication Year :
- 2015
-
Abstract
- Thrombopoietin (Thpo) signals via its receptor Mpl and regulates megakaryopoiesis, hematopoietic stem cell (HSC) maintenance and post-transplant expansion. Mpl expression is tightly controlled and deregulation of Thpo/Mpl-signaling is linked to hematological disorders. Here, we constructed an intracellular-truncated, signaling-deficient Mpl protein which is presented on the cell surface (dnMpl). The transplantation of bone marrow cells retrovirally transduced to express dnMpl into wildtype mice induced thrombocytopenia, and a progressive loss of HSC. The aplastic BM allowed the engraftment of a second BM transplant without further conditioning. Functional analysis of the truncated Mpl in vitro and in vivo demonstrated no internalization after Thpo binding and the inhibition of Thpo/Mpl-signaling in wildtype cells due to dominant-negative (dn) effects by receptor competition with wildtype Mpl for Thpo binding. Intracellular inhibition of Mpl could be excluded as the major mechanism by the use of a constitutive-dimerized dnMpl. To further elucidate the molecular changes induced by Thpo/Mpl-inhibition on the HSC-enriched cell population in the BM, we performed gene expression analysis of Lin-Sca1+cKit+ (LSK) cells isolated from mice transplanted with dnMpl transduced BM cells. The gene expression profile supported the exhaustion of HSC due to increased cell cycle progression and identified new and known downstream effectors of Thpo/Mpl-signaling in HSC (namely TIE2, ESAM1 and EPCR detected on the HSC-enriched LSK cell population). We further compared gene expression profiles in LSK cells of dnMpl mice with human CD34+ cells of aplastic anemia patients and identified similar deregulations of important stemness genes in both cell populations. In summary, we established a novel way of Thpo/Mpl inhibition in the adult mouse and performed in depth analysis of the phenotype including gene expression profiling.
- Subjects :
- Cell
Population
CD34
lcsh:Medicine
Bone Marrow Cells
Mice, Transgenic
Biology
Mice
medicine
Animals
ddc:610
education
lcsh:Science
Thrombopoietin
education.field_of_study
Multidisciplinary
Cell Membrane
lcsh:R
Hematopoietic stem cell
Hematopoietic Stem Cells
Thrombocytopenia
Molecular biology
Hematopoiesis
Cell biology
Transplantation
Haematopoiesis
medicine.anatomical_structure
lcsh:Q
Bone marrow
Receptors, Thrombopoietin
Research Article
Signal Transduction
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- PLoS ONE, Vol 10, Iss 7, p e0131866 (2015), PLoS ONE
- Accession number :
- edsair.doi.dedup.....3d7d52cb5290fc197940596cae62f724