TRPV4 is dispensable for the development of airway allergic asthma

Allergic asthma is one of the most common immune-mediated disorders affecting the lungs. It is characterized clinically by airway hyperresponsiveness, eosinophilia, enhanced IL-4 and IL-13, peribronchial inflammation with mononuclear cell infiltration, and goblet cell hyperplasia associated with increased mucus production. However, chronic asthma with repeated exposures to inhaled allergens can result in subepithelial pulmonary fibrosis. The transient receptor potential cation channel subfamily V member 4 (TRPV4) protein can promote the generation of myofibroblasts and pulmonary fibrosis. Here, we investigated the possibility that TPRV4 facilitates the development of allergic asthma and subsequent pulmonary fibrosis in the lung. To test this, wild-type (WT) and TPRV4 gene knockout (KO) mice were repeatedly sensitized with chicken ovalbumin (OVA) and repeatedly subjected to aerosol challenge with 1% OVA. We found that there were no significant differences in the development of allergic asthma between the WT and TPRV4 KO mice. Both groups of mice exhibited similar levels of airway hyperresponsiveness, IL-13, IL-5, OVA-specific IgE, eosinophilia, mucus-secreting goblet cell hyperplasia, and deposition of collagen fiber, which is a hallmark of the pulmonary fibrosis. Thus, these data suggest that TPRV4 protein is dispensable in the initiation and development of airway asthma and subsequent fibrosis.