Human hematopoietic stem/progenitor cells overexpressing Smad4 exhibit impaired reconstitution potential in vivo.
Författare
Summary, in English
Hematopoietic stem cells (HSCs) constitute a rare population of tissue-specific cells that can self-renew and differentiate into all lineages of the blood cell system. These properties are critical for tissue regeneration and clinical applications of HSCs. Cord blood is an easily accessible source of HSCs. However, the number of HSCs from one unit is too low to effectively transplant most adult patients, and expansion of HSCs in vitro has met with limited success due to incomplete knowledge regarding mechanisms regulating self-renewal. Members of the transforming growth factor-β (TGF-β) superfamily have been shown to regulate HSCs through the Smad signaling pathway, however, its role in human HSCs has remained relatively uncharted in vivo. Therefore, we asked whether enforced expression of the common-Smad, Smad4, could reveal a role for TGF-β in human hematopoietic stem/progenitor cells (HSPCs) from cord blood. Using a lentiviral overexpression approach, we demonstrate that Smad4 overexpression sensitizes HSPCs to TGF-β, resulting in growth arrest and apoptosis in vitro. This phenotype translates in vivo into reduced HSPC reconstitution capacity yet intact lineage distribution. This suggests that the Smad pathway regulates self-renewal independently of differentiation. These findings demonstrate that the Smad signaling circuitry negatively regulates the regeneration capacity of human HSPCs in vivo.
Avdelning/ar
Publiceringsår
2012-09-27
Språk
Engelska
Sidor
4343-4351
Publikation/Tidskrift/Serie
Blood
Volym
120
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
American Society of Hematology
Ämne
- Hematology
Status
Published
Forskningsgrupp
- Hematopoiesis and Gene Therapy
ISBN/ISSN/Övrigt
- ISSN: 1528-0020