miRNA expression profiling and identification of a miRNA regulator for macrophage polarization in the murine alveolar macrophage cell line MH-S.

Using the highly sensitive miRNA array, we screened differentially regulated miRNAs in IL-4-induced M2 macrophages and explored the functions of miR-378a-3p by Gene Ontology and Kyoto Encyclopedia of Genes annotation. Furthermore, the quantitative real-time polymerase chain reaction, western blot and dual luciferase reporter assay results showed that Grb2 is a specific target of miR-378a-3p, which will give new insights in disclosing the mechanism of macrophage polarization. In this study, IL-4 induced miRNAs expression in murine alveolar macrophage cell line was measured at 48 hours after exposure to 20 ng/mL IL-4. Three independent experiments were performed.