MiR-140 suppresses airway inflammation and inhibits bronchial epithelial cell apoptosis in asthma by targeting GSK3ß.

ABSTRACT

AIM OF THE STUDY Asthma is a common and complex chronic inflammatory disease induced by genetic and environmental factors that affects the airways of the lungs. MicroRNAs (miRNAs) are key regulators of various cellular processes and have been shown to be critically involved in asthma progression. The objective of our study was to clarify the function and molecular mechanism of miR-140 in the progression of asthma. MATERIALS AND METHODS: MiR-140 expression was evaluated using RT-qPCR. Pathological changes in the lung tissue were confirmed using HE and PAS staining. The levels of IL-5, TGF-ß1, and IL-13 in the serum or bronchioalveolar lavage fluid were detected with an ELISA. Cellular apoptosis was measured using a TUNEL assay. The levels of Bax, Bcl-2, Cleaved caspase-3, and glycogen synthase kinase-3ß (GSK-3ß) were verified with a western blot. GSK3ß expression was also confirmed by immunohistochemistry. The binding ability between miR-140 and GSK3ß was confirmed using a luciferase reporter assay, RNA immunoprecipitation (RIP) assay and Pull-down assay. RESULTS: MiR-140 was markedly downregulated in asthmatic mice. Additionally, miR-140 weakened airway inflammation and bronchial epithelial cell apoptosis in asthmatic mice. Further experiments revealed that miR-140 negatively regulated GSK3ß expression and could bind to GSK3ß in asthma. Finally, rescue assays demonstrated that GSK3ß overexpression rescued the effects of miR-140 on asthma progression. CONCLUSION: MiR-140 targeted GSK3ß to suppress airway inflammation and inhibit bronchial epithelial cell apoptosis in asthma.