Granulocyte colony-stimulating factor mobilizes dormant hematopoietic stem cells without proliferation in mice

• Published in: Blood 2017-04, Vol.129 (14), p.1901-1912
• Main Authors: Bernitz, Jeffrey M., Daniel, Michael G., Fstkchyan, Yesai S., Moore, Kateri
• Format: Article
• Language: English
• Subjects: Animals; Cell Proliferation - drug effects; Cell Proliferation - genetics; Gene Expression Regulation - drug effects; Gene Expression Regulation - genetics; Granulocyte Colony-Stimulating Factor - pharmacology; Hematopoietic Stem Cell Mobilization; Hematopoietic Stem Cells - cytology; Hematopoietic Stem Cells - metabolism; Mice; Mice, Transgenic; Platelet Membrane Glycoprotein IIb - biosynthesis; Platelet Membrane Glycoprotein IIb - genetics; Plenary Paper
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2016-11-752923

Granulocyte colony-stimulating factor (G-CSF) is used clinically to treat leukopenia and to enforce hematopoietic stem cell (HSC) mobilization to the peripheral blood (PB). However, G-CSF is also produced in response to infection, and excessive exposure reduces HSC repopulation capacity. Previous work has shown that dormant HSCs contain all the long-term repopulation potential in the bone marrow (BM), and that as HSCs accumulate a divisional history, they progressively lose regenerative potential. As G-CSF treatment also induces HSC proliferation, we sought to examine whether G-CSF-mediated repopulation defects are a result of increased proliferative history. To do so, we used an established H2BGFP label retaining system to track HSC divisions in response to G-CSF. Our results show that dormant HSCs are preferentially mobilized to the PB on G-CSF treatment. We find that this mobilization does not result in H2BGFP label dilution of dormant HSCs, suggesting that G-CSF does not stimulate dormant HSC proliferation. Instead, we find that proliferation within the HSC compartment is restricted to CD41-expressing cells that function with short-term, and primarily myeloid, regenerative potential. Finally, we show CD41 expression is up-regulated within the BM HSC compartment in response to G-CSF treatment. This emergent CD41Hi HSC fraction demonstrates no observable engraftment potential, but directly matures into megakaryocytes when placed in culture. Together, our results demonstrate that dormant HSCs mobilize in response to G-CSF treatment without dividing, and that G-CSF-mediated proliferation is restricted to cells with limited regenerative potential found within the HSC compartment. •G-CSF mobilizes dormant HSCs without proliferation.•Transplantation defects of mobilized peripheral blood-derived hematopoietic stem and progenitor cells are divisional history independent.