Expression levels of plasma exosomal miR-124, miR-125b, miR-133b, miR-130a and miR-125b-1-3p in severe asthma patients and normal individuals with emphasis on inflammatory factors

Abstract BackgroundIdentification of molecular markers, such as miRNAs is promising for the diagnosis of asthma and its clinical phenotypes. The aim of this study was to examine the changes in the expression of selected microRNAs in plasma exosomal fractions severe asthma patients. The expression of the miRNAs was determined in relation to the changes in serum immuno-inflammatory markers.MethodSevere asthma patients (n = 30) and healthy subjects (n = 30) were selected among the individuals referred to the asthma and allergy clinic. Blood was collected from each participant for the estimation of high sensitive C-reactive protein (hs-CRP) and total IgE in serum. The exosomal fraction of plasma was also isolated by ultra-centrifugation and processed for quantitation of miR-124, miR-125b, miR-133b, miR-130a and miR-125b-1-3p expression using quantitative real time-PCR (qRT-PCR).ResultsSerum hs-CRP and total IgE were significantly higher in asthma patients as compared to controls. Expression of miR-124, miR-133b, and miR-130a were down-regulated in asthma patients as compared to controls (p < 0.0001). However, the expression of miR-125b was significantly higher in the patients compared to controls (p < 0.0001). No major changes in miR-125b-1-3p expression was found in the study groups. Data analysis indicated that among the miRNAs, changes in miR-125b in severe asthma patients was highly correlated with the serum levels of hs-CRP and IgE.ConclusionOverexpression of miR-125b that was significantly associated with serum IgE and hs-CRP may suggest that miR-125b is linked to inflammatory reactions in asthma. However, the involvement of miR-124, miR-133b, and miR-130a in asthma complication is ruled out, because they were a poor relationship between these miRNAs and the inflammatory markers.