Exosomal miRNA19a from primary human nasal epithelial cells induce pro-inflammatory responses of macrophages via RORA

Macrophages are phagocytes that play a critical role in the immune system. They are involved in both innate and adaptive immunity by either removing pathogens or antigen presentation. It has been shown that macrophages are polarized to subgroups with distinct functions, M1 and M2. M1 polarization is characterized by pro-inflammatory and anti-cancer functions, whereas M2 macrophages promote immune suppression and tumor growth. In this study, we investigate that exosomal miRNAs from primary human nasal epithelial cells play roles in airway mucosal microenvironment. Specifically, we demonstrated that the human nasal epithelial cells treated with urban dust modulate airway mucosal microenvironment through upregulation and release of miRNAs. The result shows that the human nasal epithelial cells treated with urban dust altered miRNA expression profile and released miRNAs promotes M1 macrophage polarization. The study will further investigate exosomal miRNA mediated-communications between epithelium and macrophages in airway mucosal microenvironment.