A bittersweet finding
Reviewed by Joanna Stephens

This is an elegant study, documenting the role of, and activation of, nitrous oxide in chronic sinusitis. Bitter taste receptors (TR2) have recently been identified as novel ‘players’ in sinonasal innate immunity and in chronic rhinosinusitis. The receptors are triggered by a pathogen, in this case Pseudomonas aeruginosa, which triggers the production of nitrous oxide, a potent antimicrobial defence molecule. This is turn increases the ciliary beat frequency and therefore sinonasal mucociliary clearance. The study demonstrates the expression of a number of TR2 receptors in the sinonasal epithelium, and therefore supports an innate defensive role for these receptors. There may be a potential role for therapeutic interventions based on these findings.

Nitric oxide production is stimulated by bitter taste receptors ubiquitously expressed in the sinonasal cavity.
Yan CH, Hahn S, McMahon D et al.
AMERICAN JOURNAL OF ALLERGY AND RHINOLOGY
2017;31(2):85-92.