IWASAKI Masayuki
   Department   Research Institutes and Facilities, Research Institutes and Facilities
   Position   Assistant Professor
Article types Original article
Language English
Peer review Peer reviewed
Title Pbx1 restrains myeloid maturation while preserving lymphoid potential in hematopoietic progenitors.
Journal Formal name:Journal of cell science
Abbreviation:J Cell Sci
ISSN code:14779137/00219533
Domestic / ForeginForegin
Volume, Issue, Page 126(Pt 14),pp.3181-91
Author and coauthor Ficara Francesca, Crisafulli Laura, Lin Chenwei, Iwasaki Masayuki, Smith Kevin S, Zammataro Luca, Cleary Michael L
Publication date 2013/07
Summary The capacity of the hematopoietic system to promptly respond to peripheral demands relies on adequate pools of progenitors able to transiently proliferate and differentiate in a regulated manner. However, little is known about factors that may restrain progenitor maturation to maintain their reservoirs. Conditional knockout mice for the Pbx1 proto-oncogene have a significant reduction in lineage-restricted progenitors in addition to a profound defect in hematopoietic stem cell (HSC) self-renewal. Through analysis of purified progenitor proliferation, differentiation capacity and transcriptional profiling, we demonstrate that Pbx1 regulates the lineage-specific output of multipotent and oligopotent progenitors. In the absence of Pbx1 multipotent progenitor (MPP) and common myeloid progenitor (CMP) pools are reduced due to aberrantly rapid myeloid maturation. This is associated with premature expression of myeloid differentiation genes and decreased maintenance of proto-oncogene transcriptional pathways, including reduced expression of Meis1, a Pbx1 dimerization partner, and its subordinate transcriptional program. Conversely, Pbx1 maintains the lymphoid differentiation potential of lymphoid-primed MPPs (LMPPs) and common lymphoid progenitors (CLPs), whose reduction in the absence of Pbx1 is associated with a defect in lymphoid priming that is also present in CMPs, which persistently express lymphoid and HSC genes underlying a previously unappreciated lineage promiscuity that is maintained by Pbx1. These results demonstrate a role for Pbx1 in restraining myeloid maturation while maintaining lymphoid potential to appropriately regulate progenitor reservoirs.
DOI 10.1242/jcs.125435
PMID 23660001