Hematopoietic stem cells from mice treated with G-CSF or saline alone for 36 hours

ABSTRACT: Recent studies demonstrate that inflammatory signals regulate hematopoietic stem cells (HSCs). Granulocyte-colony stimulating factor (G-CSF) is often induced with infection and plays a key role in the stress granulopoiesis response. However, its effects on HSCs are less clear. Herein, we show that treatment with G-CSF induces expansion and increased quiescence of phenotypic HSCs, but causes a marked, cell-autonomous HSC repopulating defect associated with induction of toll-like receptor (TLR) expression and signaling. The G-CSF-mediated expansion of HSCs is reduced in mice lacking TLR2, TLR4 or the TLR signaling adaptor MyD88. Induction of HSC quiescence is abrogated in mice lacking MyD88 or in mice treated with antibiotics to suppress intestinal flora. Finally, loss of TLR4 or germ free conditions mitigates the G-CSF-mediated HSC repopulating defect. These data suggest that low level TLR agonist production by commensal flora contributes to the regulation of HSC function and that G-CSF negatively regulates HSCs, in part, by enhancing TLR signaling. RNA from KSL SLAM cells (Lineage- c-Kit+ Sca-1+ CD150+ CD48- CD41-) from bone marrow of 5-10 mice per group treated with G-CSF or saline alone was prepared using the RNA XS column kit (Machery-Nagel), amplified using the NuGen Ovation system (NuGen) and hybridized to the MoGene 1.0 ST array. This array includes 4 independent PBS control and 4 G-CSF treated groups.

ORGANISM(S): Mus musculus

SUBMITTER: laura schuettpelz 

PROVIDER: E-GEOD-55093 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress