Role of microRNA-21 in airway remodeling in asthmatic mice / 国际儿科学杂志

ABSTRACT

Objeetive Airway remodeling is an important pathological feature of asthma.This study is to investigate the role of microRNA-21 (miR-21) in airway remodeling in asthmatic mice.Methods A total of 16 female BALB/c mice were randomly divided into control group and asthma model group.Mice were sensitized and challenged by ovalbumin to establish a murine model of asthma.The mice in the normal control group were intraperitoneally injected with phosphate buffered saline for sensitization and given a phosphate buffered saline inhalation for the challenge.Twenty-four hours after the last aerosol inhalation,lung tissues of mice were sampled and subjectd to Western blot for testing expression of TGFβ type Ⅱ receptor,Smad7,and Collagen Type Ⅰ (COL Ⅰ) in lung tissue of mice of each group.Quantitative real-time PCR was used to test miR-21 expression in lung tissue of mice of each group.Target gene prediction software (TargetScan) was used to predict target gene of miR-21.293T cell was used to conduct dual-luciferase reporter gene assay for verification of miR-21 target gene.Results Compared with control group,asthma group had increased expression of COL Ⅰ protein and miR-21 in lung tissue (t =11.94,P ＜ 0.05;t =23.05,P ＜ 0.05).Smad7 and TGF-βR Ⅱ were target genes of miR-21.Conclusion miR-21 down-regulates Smad7,a target gene of miR-21,activates the TGFβ/Smad signaling pathway,and promotes airway remodeling,indicating that miR-21 may be a therapeutic target for the treatment of airway remodeling in asthma.