Figure 5.
Regulation of bone marrow stromal cell activity during G-CSF–induced HPC mobilization. (A) Bone marrow cells were recovered from the femurs and tibiae of mice by flushing and treating with collagenase and then sorted into the indicated cell populations based on CD45 and lineage expression. Shown is a representative histogram. (B) To examine cells firmly adherent to the bone matrix, the flushed femurs were injected with TRIzol to obtain the “bone fraction.” Total CXCL12 mRNA in each cell population was estimated by multiplying the measured CXCL12 mRNA by the cell number in each cell fraction; the number of cells in the bone fraction was estimated based on β-actin mRNA levels. *P < .05. (C) Cells harvested from the bone fraction were sorted into the indicated cell populations (see “Materials and methods”) and CXCL12 mRNA expression relative to β-actin expression was measured. Data represent the mean ± SEM.