International Journal of COPD (May 2023)
Effect of the Lipoxin Receptor Agonist BML-111 on Cigarette Smoke Extract-Induced Macrophage Polarization and Inflammation in RAW264.7 Cells
Abstract
En Cao,1,* Jun Xu,1,* Yuanqi Gong,2,* Jingjing Yuan,3 Anbang Chen,1 Jiayi Liu,4 Yunfei Fan,4 Xiangyang Fan,4 Xiaodong Kuang1 1Department of Pathology, Basic Medical College of Nanchang University, Nanchang, Jiangxi, People’s Republic of China; 2Department of Critical Care Medicine/ICU (Intensive Care Unit), Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China; 3Department of Physiology, School of Basic Medicine, Nanchang University, Nanchang, Jiangxi, People’s Republic of China; 4The Basic Medical School of Nanchang University, Nanchang, Jiangxi, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xiaodong Kuang, Department of Pathology, Basic Medical College of Nanchang University, Nanchang, Jiangxi, People’s Republic of China, Email [email protected]: Macrophages are known to play a crucial role in the chronic inflammation associated with Chronic Obstructive Pulmonary Disease (COPD). BML-111, acting as a lipoxin A4 (LXA4) receptor agonist, has shown to be effective in protecting against COPD. However, the precise mechanism by which BML-111 exerts its protective effect remains unclear.Methods: In order to establish a cell model of inflammation, cigarette smoke extract (CSE) was used on the RAW264.7 cell line. Afterwards, an Enzyme-linked immunosorbent assay (ELISA) kit was employed to measure concentrations of tumor necrosis factor-α (TNF-α), interleukin-1beta (IL-1β), interleukin-18 (IL-18), and interleukin-10 (IL-10) in the cell supernatants of the RAW264.7 cells.In this study, we examined the markers of macrophage polarization using two methods: quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Additionally, we detected the expression of Notch-1 and Hes-1 through Western blotting.Results: BML-111 effectively suppressed the expression of pro-inflammatory cytokines TNF-α, IL-1β, and IL-18, as well as inflammasome factors NLRP3 and Caspase-1, while simultaneously up-regulating the expression of the anti-inflammatory cytokine IL-10 induced by CSE. Moreover, BML-111 reduced the expression of iNOS, which is associated with M1 macrophage polarization, and increased the expression of Arg-1, which is associated with M2 phenotype. Additionally, BML-111 downregulated the expression of Hes-1 and the ratio of activated Notch-1 to Notch-1 induced by CSE. The effect of BML-111 on inflammation and macrophage polarization was reversed upon administration of the Notch-1 signaling pathway agonist Jagged1.Conclusion: BML-111 has the potential to suppress inflammation and modulate M1/M2 macrophage polarization in RAW264.7 cells. The underlying mechanism may involve the Notch-1 signaling pathway.Keywords: BML-111, macrophage polarization, Notch-1 signaling pathway, COPD
