The Central Role of Gasdermin D in Asthmatic Airway Inflammation and Remodeling

Emerging evidence demonstrates that pyroptosis has been implicated in the pathogenesis of asthma. GSDMD is the pyroptosis executioner. The mechanism of GSDMD in asthma remains unclear. The aim of this study was to elucidate the potential role of GSDMD in asthmatic airway inflammation and remodeling. First, we performed immunofluorescent staining and ELISA to detect the protein levels of N-GSDMD in the airway epithelium and IL-18, IL-1β in serum of both asthma patients and the healthy individuals. We demonstrated that N-GSDMD, IL-18, and IL-1β were significantly increased in mild asthma compared with that from the controls. Then, wild type and Gsdmd-knock out (Gsdmd-/-) mice were used to establish asthma model. We isolated primary macrophages and performed histopathological staining, ELISA, flow cytometry to define the roles of GSDMD in allergic airway inflammation and tissue remodeling in vivo. We observed that the production of N-GSDMD, IL-18, and IL-1β were enhanced in OVA-induced asthma mice model. The knockout of Gsdmd resulted in attenuated N-GSDMD, IL-18, and IL-1β production in both bronchoalveolar lavage fluid (BALF) and lung tissue in asthmatic mice. In addition, Gsdmd-deficiency mice exhibit a significantly reduction in airway inflammation and remodeling, which might be associated with reduced Th17 type inflammation response and M2 polarization. Third, we explored the underlying mechanism of GSDMD in asthma by bulk RNA-sequencing. We found GSDMD may improve asthmatic airway inflammation and remodeling through regulating macrophage adhesion and migration, and then lead to M2 polarization by targeting Notch signaling pathway. These findings demonstrated that GSDMD plays a critical role in the pathogenesis of allergic inflammation and tissue remodeling.