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

Abstract: Objective:  To investigate the effects of lipoxin A4 (LXA4) 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 LXA4. 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 LXA4. 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. IκBα degradation and NF-κB translocation were determined by Western blot, and NF-κB transcriptional activity was tested by transfections and luciferase activities assay. Results:  (1) LXA4 controlled LPS-induced proliferation and reactive oxygen species production. (2) LXA4 decreased LPS-induced G-CSF gene expression and protein secretion. (3) LXA4 restrained LPS-induced IκBα degradation, NF-κB translocation, and NF-κB transcriptional activity. (4) rmG-CSF could rescue the inhibitory effects of LXA4, and neutralizing anti-G-CSF Ab was able to enhance the roles of LXA4. Conclusions:  LXA4 inhibited LPS-induced proliferation and reactive oxygen species production in RAW264.7 macrophages partially through modulation of G-CSF secretion. [ABSTRACT FROM AUTHOR]