Prostaglandin E Receptor 2 (EP2) Dysregulation in Allergic Fungal Rhinosinusitis Nasal Polyp Epithelium.

OBJECTIVES: Allergic fungal rhinosinusitis (AFRS) is an eosinophilic subtype of chronic rhinosinusitis with nasal polyposis (CRSwNP). This study aimed to investigate the transcriptome of AFRS nasal polyp epithelium. METHODS: Sinonasal epithelial cells were harvested from healthy nasal mucosa and polyp tissue collected from participants undergoing elective sinonasal surgery. Primary epithelial cells were subsequently grown in air/liquid interface and subjected to RNA-seq analysis, RT-qPCR, immunoblotting, and immunostaining. RESULTS: A total of 19 genes were differentially expressed between healthy and AFRS sample epithelium. The second top candidate gene, ranked by adjusted p-value, was prostaglandin E receptor 2 (PTGER2). The upregulation of PTGER2 was confirmed by RT-qPCR and immunoblot. The presence of the EP2 receptor, encoded by the PTGER2 gene, was confirmed by immunocytochemistry. CONCLUSION: PTGER2 is a potential novel therapeutic target for AFRS. EP2 dysregulation is associated with aspirin-exacerbated respiratory disease, potentially giving insight into common mechanisms of disease in severe CRSwNP. LEVEL OF EVIDENCE: NA Laryngoscope, 135:S1-S8, 2025.