Figure 1.

Expression of PAR-2 in airway epithelial cells. A) PAR-2 expression in primary airway epithelial cell lines and primary cells from 3 patients was assayed by reverse transcription-PCR. Oral squamous epithelium cDNA was used as a control for PAR-4. b.p., base pair; Pt, patient; rt, reverse transcription. B) PAR-2 expression was confirmed by Western blot in primary sinonasal ALI culture samples (6 separate patients, unrelated to patients in A. C) Immunofluorescence using a PAR-2 antibody in submerged BEAS-2B cells revealed plasma membrane–localized staining. GLUT1 was a control for membrane localization. D, E) Immunofluorescence of PAR-2 in primary dissociated sinonasal ciliated cells showing colocalization with NKCC1 (D) and Na⁺K⁺ ATPase (E). A distinct gap was noted (arrows) between the base of the cilia (labeled with β-tubulin IV), corresponding to the apical cell body membrane and the start of basolateral NKCC1/Na⁺K⁺ ATPase immunofluorescence. PAR-2 rabbit pAb was used with mouse mAb anti-NKCC1 (top). PAR-2 mouse mAb was used with rabbit mAb anti-Na⁺K⁺ATPase (bottom). Scale bars, 10 µm. F) Representative scatter plots of PAR-2 intensity and either NKCC or Na⁺K⁺ ATPase. For all dissociated cells imaged (n = 15 with NKCC1 and n = 17 with Na⁺K⁺ ATPase), Pearson’s correlation coefficient (Pearson’s R) and Mander’s overlap coefficient (Mander’s R) for basolateral marker and PAR-2 were both ≥0.95.