Gpr97 is dispensable for inflammation in OVA-induced asthmatic mice

Background: Asthma is a complex inflammatory disorder involving the activation and invasion of various immune cells. GPR97 is highly expressed in some immunocytes, including mast cells and eosinophils, which play critical roles in asthma development. However, the role of Gpr97 in regulating airway inflammation in asthma has rarely been reported. In this study, we investigated the potential role of Gpr97 in the development of allergic asthma in mice. Methods: Relevant airway asthmatic mouse models were constructed with both wild-type and Gpr97^-/- mice sensitized to 250 μg ovalbumin (OVA). The levels of interleukin IL-4, IL-6 and IFN-γ, which are involved in OVA-induced asthma, in the bronchoalveolar lavage fluid (BALF) and the IgE level in the serum were examined by enzyme-linked immunosorbent assay (ELISA). The invasion of mast cells and eosinophils into lung tissues was assessed by immunohistochemical and eosinophil peroxidase activity assays, respectively. Goblet cell hyperplasia and mucus production were morphologically evaluated with periodic acid- Schiff (PAS) staining. Results: In our study, no obvious alteration in the inflammatory response or airway remodeling was found in the Gpr97-deficient mice with OVA-induced asthma. Neither the secretion of cytokines, including IL-4, IL-6 and IFN-γ, nor inflammatory cell recruitment was altered in the Gpr97-deficient mice. Moreover, Gpr97 deficiency did not affect airway remodeling or mucus production in the asthma mouse model. Conclusion: Our findings imply that Gpr97 might not be required for the development of airway inflammation in OVA-induced allergic asthma in mice.