Lipoxin A4 Inhibits NF-κB Activation and Cell Cycle Progression in RAW264.7 Cells

Lipoxins (LXs), including lipoxin A 4 (LXA 4 ), etc. , have been approved for potent anti-inflammatory and immunomodulatory properties. Based on the important roles of macrophages in inflammation and immunomodulation, we investigate the effects of LXA 4 on lipopolysaccharide (LPS)-induced proliferation and the possible signal transduction pathways in RAW264.7 macrophages. RAW264.7 cells were treated in vitro with or without LPS in the absence or presence of LXA 4 . [ 3 H]-TdR incorporation assay and flow cytometry were used for detecting cell proliferation and cycle, respectively. Moreover, Western blot was applied to evaluate the protein expression levels of Cyclin E, IκBα, nuclear factor-κB (NF-κB), and IκB kinase (IKK). Our research showed that LXA 4 suppressed LPS-induced proliferation, increased the proportion of the G 0 /G 1 phase, decreased the proportion of the S phase, and downregulated the expression of Cyclin E. Besides these, LXA 4 suppressed LPS-induced IκBα degradation, NF-κB translocation, and the expression of IKK. The data suggested that LXA 4 inhibited LPS-induced proliferation through the G 0 /G 1 phase arrest in RAW264.7 macrophages, and the inhibitory effect might depend on NF-κB signaling transduction pathway.