ABSTRACT
Accumulating evidence has shown that microRNA (miR) derived from M1 macrophage-derived exosomes can regulate the progression of hepatocellular carcinoma (HCC). However, the effect of miR-326 derived from M1 macrophage-derived exosomes on HCC has not been reported. Therefore, the objective of the present study was to explore the mechanism of exosomal miR-326 from M1 macrophages in regulating HCC cell progression. RT-qPCR detected miR-326 expression in HCC cell lines. miR-326 expression in HCC was altered by transfection, and the effect of miR-326 on CD206 and NF-κB expression, cell proliferation, colony formation, migration, apoptosis and invasion was detected. Subsequently, exosomes were isolated from M1 macrophages. RT-qPCR identified miR-326 expression in M1 macrophage-derived exosomes. miR-326 expression in M1 macrophage-derived exosomes was changed by transfection. M1 macrophage-derived exosomes were co-cultured with HCC cells to figure out their effects on the biological progress of HCC cells. Finally, in vivo experiments were performed to verify the in vitro results. MiR-326 was decreased in HCC cells and enriched in M1 macrophage-derived exosomes. Up-regulating miR-326 would inhibit HCC cell proliferation, colony formation, migration, invasion, and CD206 and NF-κB expression and promoted apoptosis, and inhibited the growth of HCC tumors in vivo, while down-regulating miR-326 showed opposite effects. M1 macrophage-derived exosomes inhibited HCC cell proliferation, colony formation, migration, invasion, and CD206 and NF-κB expression and enhanced apoptosis, while overexpression of miR-326 enhanced the effect of M1 macrophage-derived exosomes on HCC cells. It is revealed that M1 macrophages-derived exosomal miR-326 suppresses proliferation, migration and invasion as well as advances apoptosis of HCC through down-regulating NF-κB expression.
ABSTRACT
BACKGROUND: The macrophage is one of the most important types of immune cells that protect against harmful stimuli. Macrophage activation plays a pivotal role in the progression and development of various inflammatory diseases. The neurokinin 1 receptor (NK-1R) is a G protein-coupled receptor that plays an important role in inflammatory diseases. Aprepitant is a kind of NK-1R antagonist. The purpose of this study is to determine the protective effect of aprepitant in lipopolysaccharide (LPS)-induced inflammatory responses in macrophages. METHODS: We examined the anti-inflammatory and anti-oxidant effects of aprepitant in LPS-treated RAW264.7 macrophages by using real-time PCR, ELISA, and Western blot analysis. We also assessed cellular oxidative stress signaling by measuring the levels of cellular MDA, total ROS, and NADPH oxidase expression. Cellular NO production was measured by DAF-FM DA staining. The inhibitory effect of aprepitant against NF-κB signaling was evaluated by luciferase assay and Western blot analysis. RESULTS: The expression of NK-1R is increased in LPS-induced macrophages, suggesting a potential role of the receptor in the inflammatory response. We show that aprepitant protects macrophages against oxidative stress by reducing the generation of ROS and the expression of NOX-4. Furthermore, aprepitant inhibits the secretion of pro-inflammatory cytokines and chemotactic factors by mediating the NF-κB signaling pathway. CONCLUSION: The NK-1R receptor antagonist aprepitant acts as an anti-inflammatory agent, indicating that the blockage of the NK-1R pathway in macrophages has the potential to suppress inflammation.
