Profiling of miRNAs in pediatric asthma: upregulation of miRNA-221 and miRNA-485-3p.

The aim of this study was to investigate the expression profiles of microRNAs (miRNAs) in pediatric asthma and to determine candidate miRNAs responsible for the pathogenesis of this disease. Microarrays were used to detect the differences in the miRNA expression levels between asthmatic children and controls. Airway inflammation was evaluated by cell counting and tissue biopsy in an ovalbumin (OVA)-induced murine asthma model. Real-time polymerase chain reaction (PCR) was used to verify the differentially expressed miRNAs. The targets of the identified miRNAs were analyzed by bioinformatic analysis. The sprouty-related protein with an EVH1 domain-2 (Spred-2) protein content was assessed by western blotting. Differences were observed in the expression of miRNAs between the asthmatic children and controls. Upregulation of miRNA-221 and miRNA-485-3p in pediatric asthmatics and murine asthma models were verified by real-time PCR. Spred-2, a predicted target of miRNA-221 and miRNA-485-3p, was downregulated in murine asthma models. Upregulation of miRNA-221 and miRNA-485-3p may regulate the pathogenesis of asthma.