The Targeting Function of CIRC-0005519 to miR-625-5p as Well as Its Effects on Bronchial Epithelial Cell Injury in Children with Severe Asthma

Abstract

This work was intended to explore the effect of circ-0005519 on the apoptosis of bronchial epithelial cells in children with severe asthma and its molecular mechanism. To this end, asthma’s inflammatory environment was simulated by using 1 mg/L lipopolysaccharide (LPS) to induce human bronchial epithelial 16HBE cells, which were considered the 16HBE model cells. After transfection, these 16HBE model cells were divided into following groups: control group, model+si-NC group, model+si-circ-0005519 group, model+miR-NC group, model+miR-625-5p group, model+si-circ-0005519+anti-miR-NC group, and model+si-circ-0005519+anti-miR-625-5p group. A series of experiments were then carried out, including RT-qPCR assay for testing circ-0005519 and miR-625-5p expressions, flow cytometry assay for analyzing cell apoptosis, western blot for testing protein expression, ELISA assay for detecting IL-6. TNF-α, IL-13, IL-8 expression, and dual-luciferase reporter confirm the targeted functions of circ-0005519 to miR-625-5p. The results displayed highly expressed circ-0005519 and lowly expressed miR-625-5p in 16HBE model cells induced by lipopolysaccharide. Furthermore, we also found increases in apoptosis, Bax expression, and levels of IL-6, TNF-α, IL-13, and IL-8, as well as a decrease in Bcl-2 expression. Additionally, our data revealed that silencing circ-0005519 or overexpressing miR-625-5p would affect these 16HBE model cells, including decreases in apoptosis, Bax expression, and levels of IL-6, TNF-α, IL-13, and IL-8, as well as an increase in Bcl-2 expression. The targeted binding function of circ-0005519 to miR-625-5p was also confirmed, in which interference miR-625-5p would weaken the influences of silencing circ-0005519 on 16HBE cells. These results suggested that silencing circ-0005519 could inhibit apoptosis of lipopolysaccharide-induced bronchial epithelial cells via targeted binding functions to miR-625-5p.