Figure 2. PGE₂ increases hematopoietic migration and homing.

A.) Mouse SKL cells or human CD34⁺ cells were treated on ice with 1 μM 16,16-dimethyl PGE₂ (dmPGE₂) or vehicle control for 2 hours, washed, and then re-suspended in media with 10% heat inactivated fetal bovine serum and cultured at 37 °C for 16 hours. After incubation, cells were washed, re-suspended in RPMI/0.5% BSA, and allowed to migrate to 100 ng/ml recombinant mouse or human SDF-1α through a two-chamber, 6.5 mm diameter, 5 μm pore transwell. Cells migrating to the bottom chamber were enumerated by flow cytometry, and the % increase in migration over vehicle control determined.

B.) SKL cells from CD45.1 and CD45.2 mice were isolated by FACS sorting and treated with either dmPGE₂ or vehicle. Treated SKL cells were then transplanted competitively, head-to-head into lethally irradiated (1100 cGys) CD45.1/CD45.2 hybrid mice, allowing for distinction of vehicle treated, dmPGE₂ treated and recipient SKL cells within the same animal. Sixteen hours post-transplant, hind limb bones were isolated and homed SKL cells determined by flow cytometry. Mean ± SEM, N=10 mice, each assayed individually, are shown.