Protective Effect of Circular RNA (CircRNA) Ddx17 in Ovalbumin (OVA)-Induced Allergic Rhinitis (AR) Mice.

BACKGROUND CircRNAs are involved in multiple biological processes, especially when they act as sponges of miRNA. Thus, the present study investigated the effect of circDdx17 on allergic rhinitis (AR) in an animal model, and determined the miRNA that was involved in this effect. MATERIAL AND METHODS The AR model was created by repetitive stimulation of ovalbumin (OVA). The levels of mRNAs in plasma were determined by qPCR. CircDdx17 stability was assessed using RNase R. The interaction between circDdx17 and miR-17-5p was predicted by bioinformatics and confirmed by dual luciferase assay. Moreover, the frequencies of rubbing and sneezing and pathological changes were recorded, and OVA-specific IgE, tumor necrosis factor (TNF)-alpha, interleukin (IL)-4, and IL-5 levels were detected by ELISA. RESULTS Levels of circDdx17 were decreased in OVA-induced AR mice, and miR-17-5p interacted with circDdx17 in spleen cells derived from mice. Moreover, circDdx17 overexpression reduced the expression of miR-17-5p, OVA-specific IgE, TNF-alpha, IL-4, and IL-5, as well as the frequencies of rubbing and sneezing, and alleviated pathological changes in OVA-induced AR mice. CONCLUSIONS CircDdx17 appears to have a protective effect on mice in the progression of AR. Specifically, overexpression of circDdx17 inhibited the expression of miR-17-5p and alleviated the condition of AR. Therefore, circDdx17 appears to be a good candidate for use in prevention of AR. However, the detailed mechanism underlying the circDdx17/miR-17-5p regulatory pathway requires further study.