Fig. 2.

Polymorphonuclear neutrophil (PMN) OSM expression is dependent on granulocyte (G) macrophage (M)-colony-stimulating factor (GM-CSF) but not G-CSF. A: effects of blocking endogenous G-CSF and GM-CSF on OSM expression in neutrophils. Isolated neutrophils were incubated on monolayers of IL-1-stimulated HUVEC for 1 h with and without blocking antibody against GM-CSF or G-CSF. The neutrophils were collected and mRNA levels for OSM were determined by quantitative real-time PCR. Data are presented as fold change in transmigrated over nontransmigrated neutrophils ± SE. *P < 0.01 compared with absence of blocking antibody or presence of anti-G-CSF antibody; n = 6. B: OSM release by PMNs is dependent on GM-CSF but not G-CSF or IL-8. Isolated neutrophils were incubated in the presence of recombinant G-CSF, IL-8, or GM-CSF for either 1 or 4 h. Culture supernatant was collected and analyzed for OSM by ELISA. *P < 0.01 compared with all other groups.