miRNA expression in serum and PBMCs isolated from middle-aged and elderly patients during asthma exacerbation

microRNAs are short, noncoding RNA molecules involved in many inflammatory processes including bronchial asthma. Rhinoviruses are the main cause of acute asthma attack and may be involved in miRNA profile dysregulation. The aim of the study was to investigate the serum miRNA profile during asthma exacerbation in middle-aged and elderly patients. We also evaluated in this group in vitro response to rhinovirus 1b exposure. Seventeen middle-aged and elderly asthmatics were admitted to an outpatient clinic during asthma exacerbation and within a period of 6-8 weeks later. Blood samples were collected from the subjects and PBMCs were isolated. Cells were cultured in the presence of Rhinovirus 1b and with the medium only, and, after 48 h. miRNA expression (miRNA-19b, -106a, 126a, and -146a) isolated from serum and PBMCs (cultures) was evaluated with RT-PCR. Cytokines (INF-γ, TNF-α, IL6, and Il-10) in culture supernatants were evaluated with flow cytometry. On exacerbation visit patients demonstrated higher expression of serum miRNA-126a and -146a as compared to follow-up visit. There was a positive correlation between asthma control test results and miRNA-19, -126a, -146a. There was no other significant association between patient characteristics and the miRNA profile. Rhinovirus exposure did not changed miRNA expression in PBMCs as compared to medium on both visits. Cytokine production in culture supernatants significantly increased after rhinovirus infection. The group of middle-aged and elderly patients demonstrated changed levels serum miRNA during asthma exacerbation as compared to follow-up visit; however, correlations between their expression and clinical features were hardly noticeable. Rhinovirus did not affect expression of miRNA in PBMCs; yet, it induced cytokine production.