Effects of lipoxin A4 on lipopolysaccharide induced proliferation and reactive oxygen species production in RAW264.7 macrophages through modulation of G-CSF secretion

Abstract

To investigate the effects of lipoxin A(4) (LXA(4)) on lipopolysaccharide (LPS) induced proliferation and reactive oxygen species production in RAW264.7 macrophages. 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. (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). LXA(4) inhibited LPS-induced proliferation and reactive oxygen species production in RAW264.7 macrophages partially through modulation of G-CSF secretion.