LncRNA MALAT1 regulates cigarette smoke induced airway inflammation by modulating miR-30a-5p/JNK signaling pathway

Chronic airway inflammation induced by cigarette smoke (CS) plays an essential role in the pathogenesis of chronic obstructive pulmonary disease (COPD). MALAT1 is involved in a variety of inflammatory disorders. However, studies focusing on the interaction between MALAT1 and CS-induced airway inflammation remain unknown. The present study investigated the effects and mechanisms of MALAT1 in CS-induced airway inflammation in the pathogenesis of COPD. RT-qPCR was employed to determine the mRNA levels of MALAT1, miR-30a-5p and inflammatory cytokines. Protein concentrations of IL-1β and IL-6 in cell culture supernatant and mouse bronchoalveolar lavage fluid (BALF) were assessed by ELISA assay kits. Dual-luciferase reporter assay was conducted to verify the interaction between MALAT1 and miR-30a-5p. The protein expression of JNK and p-JNK was determined by western blot (WB). MALAT1 was highly expressed in cigarette smoke extract (CSE)-treated human bronchial epithelial cells (HBECs) and COPD mice lung tissues. Knockdown of MALAT1 significantly alleviate CS-induced inflammatory response. MALAT1 directly interacted with miR-30a-5p and knockdown of miR-30a-5p significantly inhibit the protective effects of MALAT1 silencing after CS exposure. Additionally, our results showed that miR-30a-5p could regulate inflammation via modulating the activation of JNK signaling pathway. Moreover, our results demonstrated MALAT1 could activate JNK signaling pathway by sponging miR-30a-5p. Our results demonstrated MALAT1 promotes CS-induced airway inflammation by inhibiting the activation of JNK signaling pathway via sponging miR-30a-5p.