microRNA-183 down-regulates the expression of BKCaβ1 protein that is related to the severity of chronic obstructive pulmonary disease

Objectives: The aim of this study was to investigate the relationship between the expression of microRNA (miRNA)183 and Ca2+-activated K+ channels beta 1 subunit (BKCa beta 1) in the lung tissues of patients with chronic obstructive pulmonary disease (COPD). Methods: Quantitative real-time polymerase chain reaction and Western blotting were used for detecting the expression of miRNA-183 and BKCa beta 1 in the lung tissues from 45 COPD patients and 30 lung cancer patients without COPD. Possible miRNAs that target BKCa beta 1 were forecasted by bioinformatics. The expression of these miRNAs in the peripheral blood of COPD patients was also examined. After transfecting vascular smooth muscle cells with pGCMV/EGFP/miR-183 plasmid, the expression of miRNA-183 and BKCa beta 1 were detected by quantitative real-time polymerase chain reaction and Western blotting. Results: The expression of BKCa beta 1 in the lung tissues of COPD patients was significantly lower than control. Western blotting data showed that the expression of BKCa beta 1 protein in COPD group was significantly lower than control. After transfecting the vascular smooth muscle cells with pGCMV/EGFP/miR-183 plasmid, we found that the level of BKCa beta 1 mRNA was not significantly reduced by the increase of miRNA-183 level, but the expression of BKCa beta 1 protein was down-regulated. Conclusions: The present study indicated that miRNA-183 might play a role in the expression of BKCa beta 1, and the expression of miRNA-183 and BKCa beta 1 were possibly related with the pathogenetic pathways of COPD.