RRC ID 59685
Author Kawano A, Ariyoshi W, Yoshioka Y, Hikiji H, Nishihara T, Okinaga T.
Title Docosahexaenoic acid enhances M2 macrophage polarization via the p38 signaling pathway and autophagy.
Journal J Cell Biochem
Abstract Macrophages, critical modulators of the immune response, polarize into various phenotypes, including M1 and M2. M1 macrophages are typically activated by lipopolysaccharide and produce proinflammatory cytokines. Conversely, M2 macrophages are activated by stimulation with interleukin 4 (IL)-4 and promote tissue remodeling and anti-inflammatory reactions. Recently, polyunsaturated fatty acids (PUFAs) have been shown to play important roles in the regulation of inflammation. Docosahexaenoic acid (DHA), a PUFA, has anti-inflammatory effects on chronic inflammatory disease, but its role in macrophage polarization remains unclear. In this study, we clarified the effects of DHA on macrophage polarization using U937 cells. Treatment with DHA resulted in upregulation of M2 macrophage markers and increased secretion of anti-inflammatory cytokines by U937 cells. IL-4, but not DHA, triggered phosphorylation of signal transducer and activator of transcription 6 (STAT6). DHA enhanced the expression of krüppel-like factor-4 (KLF4), a transcription factor involved in the regulation of macrophage polarization and increased the phosphorylation of p38 mitogen-activated protein kinase (MAPK). A selective inhibitor of p38 MAPK downregulated the expression of CD206 in DHA-treated U937 cells. Moreover, inhibitors of autophagy suppressed the phosphorylation of p38 MAPK and the expression of CD206 in DHA-treated U937 cells. Expression of microtubule-associated protein light chain 3-II, which is involved in autophagosome formation, was enhanced in DHA-treated U937 cells. Taken together, these results indicated that DHA enhanced the expression of M2 macrophage markers through the p38 MAPK signaling pathway and autophagy, suggesting that DHA regulates M2 macrophage polarization and plays an important role in innate immunity.
Volume 120(8)
Pages 12604-12617
Published 2019-8-1
DOI 10.1002/jcb.28527
PMID 30825233
MeSH Anti-Inflammatory Agents / pharmacology Autophagy* Docosahexaenoic Acids / metabolism Docosahexaenoic Acids / pharmacology* Humans Inflammation* Interleukin-4 / metabolism MAP Kinase Signaling System* Macrophages / drug effects* Macrophages / metabolism Macrophages / physiology THP-1 Cells U937 Cells
IF 3.448
Times Cited 6
Human and Animal Cells U-937 DE-4(RCB0435)