miR-181a regulates CSE-induced autophagy dysfunction and releases of pro-inflammatory factors in NR8383 alveolar macrophages

AIM:To investigate the effect of microRNA-181a (miR-181a) on cigarette smoke extract (CSE)-induced autophagy disorder and releases of pro-inflammatory factors in NR8383 rat alveolar macrophages. METHODS:The NR8383 cells were treatment with 5%,10% and 20% CSE. The release levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-8 were measured by ELISA. The level of miR-181a was detected by RT-qPCR. The numbers of autophagosomes were observed by Cyto-ID staining. The expression levels of LC3-Ⅱ, beclin-1 and p62 were determined by Western blot. NR8383 cells were pretreated with autophagy inhibitor 3-methyladenine (3-MA) or autophagy agonist rapamycin (Rapa) before treatment with 20% CSE, and the release levels of TNF-α, IL-6 and IL-8 were measured by ELISA. Furthermore, NR8383 cells were transfected with miR-181a mimic or miR-181a inhibitor before treatment with 20% CSE, and the release levels of TNF-α, IL-6 and IL-8, and the expression of LC3-Ⅱ, beclin-1 and p62 were detected by ELISA and Western blot, respectively. RESULTS:CSE increased release levels of pro-inflammatory factors and autophagy disorder in a concentration-dependent manner in the NR8383 cells (P<0.05). 3-MA increased CSE-induced releases of pro-inflammatory factors. However, Rapa partially reversed CSE-induced releases of pro-inflammatory factors. Additionally, miR-181a mimic inhibited CSE-induced releases of pro-inflammatory factors and promoted autophagy. However, miR-181a inhibitor increased CSE-induced releases of pro-inflammatory factors and autophagy disorder. CONCLUSION:miR-181a regulates CSE-induced releases of pro-inflammatory factor in the NR8383 cells, which may be related to the regulatory role of miR-181a in autophagy disorder.