Effects of lipoxin A(4) on lipopolysaccharide induced proliferation and reactive oxygen species production in RAW264.7 macrophages through modulation of G-CSF secretion.

OBJECTIVE: To investigate the effects of lipoxin A(4) (LXA(4)) on lipopolysaccharide (LPS) induced proliferation and reactive oxygen species production in RAW264.7 macrophages.
METHODS: RAW264.7 macrophages were treated with or without LPS in the absence or presence of LXA(4). In another experiment, the cells were incubated with rmG-CSF (recombinant mouse granulocyte-colony stimulating factor) or neutralizing anti-G-CSF Ab in the absence or presence of LPS and LXA(4). The proliferation effects were detected by Cell Counting Kit-8 assay. Reative oxygen species were quantified by flow cytometry and laser confocal scanning microscopy. G-CSF gene expression and protein secretion were measured by real time PCR and ELISA, respectively. IkappaBalpha degradation and NF-kappaB translocation were determined by Western blot, and NF-kappaB transcriptional activity was tested by transfections and luciferase activities assay.
RESULTS: (1) LXA(4) controlled LPS-induced proliferation and reactive oxygen species production. (2) LXA(4) decreased LPS-induced G-CSF gene expression and protein secretion. (3) LXA(4) restrained LPS-induced IkappaBalpha degradation, NF-kappaB translocation, and NF-kappaB transcriptional activity. (4) rmG-CSF could rescue the inhibitory effects of LXA(4), and neutralizing anti-G-CSF Ab was able to enhance the roles of LXA(4).
CONCLUSIONS: LXA(4) inhibited LPS-induced proliferation and reactive oxygen species production in RAW264.7 macrophages partially through modulation of G-CSF secretion.