Evaluation of Selected IL6/STAT3 Pathway Molecules and miRNA Expression in Chronic Obstructive Pulmonary Disease - the Search for New Diagnostic Markers

Background: COPD has been regarded as a global epidemic due to an increase in pollution and tobacco exposure. Therefore, the study of molecular mechanism as the basis for modern therapy is important. Objective: The aim of the study was the assessment of gene expression levels, IL-6, IL-6ST, PIAS3, STAT3, and miRNAs, miR-1, miR-106b, miR-155, in patients with COPD. Methods: Induced sputum as well as PBMC were collected from 40 patients clinically verified according to the GOLD 2017 (A-D) classification and from the control group (n = 20). The levels of gene and miRNA expression were analysed by qPCR. Results: Statistically significant differences between the study group vs. control group were observed for IL-6 (P = 0.008, Mann-Whitney U test), and miR-155 (P = 0.03, Mann-Whitney U test). There were statistically significant differences between patients: current smokers vs. ex- smokers for STAT3 , (P = 0.04, Mann-Whitney U test) and miR-155 (P = 0.03, Mann-Whitney U test) with a higher expression in current smokers. Conclusions: Differences in gene expression levels of the IL-6 / gp130 / STAT3 pathway and miRNA depending on the smoking status and classification of patients according to GOLD suggest the importance of these genes in the pathogenesis of COPD and may indicate their potential utility in monitoring the course of the disease.