Up-Regulation of Protease-Activated Receptor 2 in Allergic Rhinitis

Objectives: We compared the patterns of PAR-2 messenger RNA (mRNA) and protein expression in the nasal mucosa of subjects with and without allergic rhinitis. Methods: Biopsy specimens were obtained from 10 patients with allergic rhinitis and 10 normal controls. RNA was extracted from the nasal mucosa, and semiquantitative reverse transcription-polymerase chain reaction was performed for PAR-2. Tissue sections were immunostained for PAR-2 by use of specific antibody. Results: The expression levels of PAR-2 mRNA in allergic rhinitis nasal mucosa were significantly up-regulated as compared with those in normal nasal mucosa. PAR-2 immunoreactivity was observed in the epithelium and submucosal glands in both normal controls and subjects with allergic rhinitis. Stronger immunoreactivity for PAR-2 was observed in allergic rhinitis nasal mucosa as compared with normal nasal mucosa. Conclusions: These results suggest that PAR-2 may be involved in allergic nasal inflammation.