title: Effects of microRNA-21 on the interleukin 12/signal transducer and activator of transcription 4 signaling pathway in asthmatic mice.
abstract: OBJECTIVE
  To study the effect of microRNA-21 (miRNA-21) on the regulation of the interleukin 12 (IL-12)/signal transducer and activator of transcription 4 (STAT4) pathway in the lung tissue of asthmatic mice.
  
  
  METHODS
  Forty five male C57BL/6 mice were randomly divided into three groups of 15 mice each: normal control, asthmatic model, and dexamethasone. Our mouse model of allergic asathma was established using OVA sensitization and challenge. Hematoxylin and eosin staining was performed to observe the pathological changes in lung tissue morphology. Both the total cell number and the amount of eosinophils (EOS) in the bronchoalveolar lavage fluid (BALF) were manually counted. The expression of miRNA-21 was detected by real time quantitative PCR. The expression levels of IL-12 and STAT4 in lung tissue were assayed via western blot, and immunohistochemistry was used to observe the distribution of their expression.
  
  
  RESULTS
  The expression levels of miRNA-21 as well as the total number of BALF cells and EOS were significantly higher in the asthmatic model group than in the control or dexamethasone groups, with significantly higher amounts found in the dexamethasone group than in the control group. The expression levels of IL-12 and STAT4 proteins were lower in the asthmatic model group than in the control and dexamethasone groups, with a significantly lower expression of IL-12 and STAT4 in the dexamethasone group than in the control group.
  
  
  CONCLUSIONS
  The expression level of miRNA-21 was significantly increased and the expression level of IL-12 and STAT4 proteins was significantly decreased in allergic asthmatic mice compared with normal control mice. These findings suggest a role for miRNA-21 and the IL-12/STAT4 pathway in the development of allergic asthma.
authors.affiliation: Medical College of Lishui University, Lishui, PR China.
authors.forename: Song-Quan
authors.initials: SQ
authors.lastname: Wu
authors.affiliation: Medical College of Lishui University, Lishui, PR China.
authors.forename: Guang-Li
authors.initials: GL
authors.lastname: Wang
authors.affiliation: The People's Hospital of Lishui City, PR China.
authors.forename: Ling-Yun
authors.initials: LY
authors.lastname: Li
authors.affiliation: Zhejiang University School of Medicine, Hangzhou, RP China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ji
keywords: IL-12; allergic asthma; miRNA-21; signal transducer and activator of transcription 4 (STAT4)