MiRNA expression profile is altered upon cystic fibrosis pulmonary exacerbation

Previous studies in respiratory diseases showed that differentially expressed miRNAs in sputum and plasma predominantly regulate inflammatory signalling pathways. We assumed that miRNAs are crucial regulators of aberrant immune response during pulmonary exacerbations in cystic fibrosis and that expression profile in the airways and peripheral blood may underlie pulmonary exacerbation (PE) and, in combination with clinical data, will identify biomarkers for PE in pediatric patients. In the study we included 40 pediatric CF patients analyzed during pulmonary exacerbation and in stable condition. In all subjects we assessed blood morphology, microbiology, lung function and chest imaging. Severity of symptoms was assessed using Schwachman–Kulczycki score. We analyzed the miRNA expression profile from sputum and blood of 6 patients using next generation sequencing method. For replication of NGS result for selected miRNA genes by qPCR, we used sputum from 34 CF patients. Analysis form NGS were done in Base Space software, other statistical analyses were done in Statistica package. The miRNA profiling from sputum showed 1 downregulated (miR-27b-3p) and 3 upregulated miRNA genes (miR-486-5p, miR-451a, miR-223) during exacerbation as compared to remission (p adj MiRNA gene expression changes in the airways, but not peripheral blood, may underlie CF pulmonary exacerbation in pediatric patients. The study was supported by the Polish National Science Centre, grant no. 2016/22/E/NZ5/00383 (A. Szczepankiewicz).