Methods : BALB/c mice were sensitized and challenged with ovalbumin (OVA). Anti-miR-21 antagomir and control scrambled RNA was daily injected by intranasal inhalation from the day of sensitization 5 times a week. Changes of cell counts, Th2 cytokines in bronchoalveolar (BAL) fluid and airway hyperresponsiveness (AHR) were evaluated. Histopathologic changes and expression of miR-21 were compared in lung tissues between antagomir treatment group and control groups.
Results : Treatment of anti-miR-21 antagomir suppressed AHR compared with OVA challenged group and scrambled RNA treatment group. Antagomir treatment reduced total cell counts and eosinophil counts in BAL fluid. Th2 cytokines such as IL-4, IL-5 and IL-13 were significantly decreased in BAL fluid of anti-miR-21 antagomir treatment group.
Conclusions : Antagonism of miR-21 by antagomir inhalation had suppressive effects on development of allergic airway inflammation in acute bronchial asthma model. These results suggest that miR-21 antagomir could be a potential target agent for the treatment of bronchial asthma.
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2) Lu TX, Hartner J, Lim EJ, Fabry V, Mingler MK, Cole ET, et al. MicroRNA-21 limits in vivo immune response-mediated activation of the IL-12/IFN-gamma pathway, Th1 polarization, and the severity of delayed-type hypersensitivity. Journal of immunology 2011;187:3362-73.