Altered polarization of PAR-2 signaling during airway epithelial remodeling

Abstract

Background: Protease-activated receptor 2 (PAR-2) is activated by proteases involved in allergy and triggers airway epithelial secretion and inflammation. PAR-2 is normally expressed basolaterally in differentiated nasal ciliated cells.Objective: We tested if epithelial remodeling during diseases characterized by loss of cilia and squamous metaplasia may alter PAR-2 polarization.Methods: Endogenous PAR-2 responses were measured by live cell calcium and cilia imaging, measurement of fluid secretion, and quantification of cytokines. We utilized airway squamous cell lines, primary differentiated air-liquid interface cultures, and tissue explants. Cells were exposed to disease-related modifiers that alter epithelial morphology, including IL-13, cigarette smoke condensate, and retinoic acid deficiency. We used concentrations and exposure times that altered epithelial morphology without causing breakdown of the epithelial barrier, likely reflecting early disease states.