LAUSR

Exposure to atmospheric particulate matter (PM) has been related to the increasing incidence and mortality of pulmonary diseases, where microRNAs (miRNAs) play significant roles in these biological and pathological processes. In the present study, we found that miR-382-5p played an anti-inflammatory role in pulmonary inflammation induced by fine particulate matter (PM2.5) or diesel exhaust particles (DEPs) in vitro and in vivo. The expression level of miR-382-5p was downregulated, while its target gene, namely CXCL12, was elevated in HBE cells after exposure to PM2.5 or DEPs. Mechanistically, PM2.5 or DEPs exposure increased CXCL12/MMP9 expression via miR-382-5p inhibition, subsequently triggered pulmonary inflammation. Furthermore, antagonizing the function of CXCL12 significantly reduced the expression of MMP9 and local inflammation induced by PM2.5 or DEPs. PM2.5 or DEPs caused apoptosis and G1 phase arrest could be partially restored by overexpression of miR-382-5p and antagonism of CXCL12. In a murine model, enhanced miR-382-5p expression effectively reduced expression levels of CXCL12, MMP9 and inflammatory cytokines, hereby protected lung tissues against PM2.5 or DEPs-induced lesions. Collectively, the miR-382-5p/CXCL12/MMP9 pathway may provide a mechanism, which mediates inflammatory response to PM2.5 or DEPs exposure.