MicroRNA-629-3p Promotes Interleukin-13-Induced Bronchial Epithelial Cell Injury and Inflammation by Targeting FOXA2

Abstract

Objective: Asthma is a chronic pulmonary inflammatory disease. MicroRNA (miR)-629-3p expression is reported to be up-regulated in the sputum of asthma patients. Nonetheless, miR-629-3p's role and mechanism in asthma remain largely unknown. This study is aimed at exploring miR-629-3p's role in regulating the injury and inflammation of bronchial epithelial cells.

Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to detect the expression levels of miR-629-3p and forkhead box a2 (FOXA2) mRNA in 16HBE cells treated with interleukin-13 (IL-13). 16HBE cell viability was evaluated using the cell counting kit-8 (CCK-8) assay, and cell apoptosis was analyzed by a flow cytometer. The levels of C-C motif chemokine ligand 11 (CCL11), C-C motif chemokine ligand 26 (CCL26), C-C motif ligand 2 (CCL-2)/mono-cyte chemotactic protein-1 (MCP-1), interleukin-1 beta (IL-1b), and interleukin 6 (IL-6) in 16HBE cell supernatant were detected through enzyme-linked immunosorbent assay (ELISA). The downstream target genes of miR-629-3p were predicted through bioinformatics. Besides, the targeted relationship between miR-629-3p and FOXA2 mRNA 3'-UTR was verified by dual-luciferase reporter gene assay. Western blot was utilized to determine the regulatory effects of miR-629-3p on the expression of FOXA2 protein in 16HBE cells.

Results: MiR-629-3p expression was significantly enhanced in IL-13-stimulated 16HBE cells while the FOXA2 mRNA and protein levels were significantly down-regulated. The transfection of miR-629-3p mimics inhibited 16HBE cells' viability, and promoted the apoptosis and the secretion of chemokines CCL11, CCL26, CCL-2/MCP-1, IL-1b, and IL-6 of 16HBE cells, whereas inhibiting miR-629-3p had the opposite effects. Moreover, FOXA2 was identified as a downstream miR-629-3p target, and its overexpression reversed the effects of the miR-629-3p on 16HBE cells.

Conclusion: MiR-629-3p promotes IL-13-induced 16HBE cells' injury and inflammation by targeting FOXA2.

Keywords: Asthma; Cell damage; FOXA2; Inflammation; MiR-629-3p.