Background
Mucociliary transport function in the airway mucosa is essential for maintaining a clean mucosal surface. This function is impaired in upper and lower airway diseases. Nasal polyps are a typical pathological feature of prolonged rhinosinusitis. Like the ordinary nasal mucosa, nasal polyps have a ciliated pseudostratified epithelium with vigorous ciliary beating. We herein measured ex vivo mucociliary transport velocity (MCTV) and ciliary beat frequency (CBF) and explored the expressions of planar cell polarity (PCP) proteins in nasal polyps in comparison with turbinate mucosae.
Methods
Inferior turbinates and nasal polyps were collected from patients with chronic rhinosinusitis during endoscopic sinonasal surgery. Ex vivo MCTV and CBF were measured using a high-speed digital imaging system. Expressions of PCP proteins were explored by fluorescence immunohistochemistry and quantitative RT-PCR.
Results
The MCTV of nasal polyps was significantly lower than that of the turbinates (7.43±2.01 vs. 14.56±2.09μm/s; P=0.0361), whereas CBF did not differ between the two tissues. The MCTV vector was pointed to the posteroinferior direction in all turbinates with an average inclination angle of 41.0 degrees. Immunohistochemical expressions of Dishevelled-1, Dishevelled-3, Frizzled3, Frizzled6, Prickle2 and Vangl2 were lower in the nasal polyps than in the turbinates. The expression levels of mRNAs for Dishevelled-1, Dishevelled-3 and Frizzled3 in the nasal polyps were also decreased in comparison with the turbinates.
Conclusions
These results indicate that ciliary transport in nasal polyps is impaired although vigorous ciliary beating is maintained, and that the impairment may be caused by a decrease in Dishevelled/Frizzled proteins and resultant PCP disarrangement.