International Journal of Oral Biology

The Korean Academy of Oral Biology (대한구강생물학회)
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Expression of Bitter Taste Receptors in Human Nasal Respiratory Epithelium

  • An, Jeong-Mi (Department of Oral biology, Yonsei University, College of Dentistry) ;
  • Wu, Hee-Won (Department of Otolaryngology, School of Medicine, Ajou University) ;
  • Kim, Hyun-Jun (Department of Otolaryngology, School of Medicine, Ajou University) ;
  • Kim, Chang-Hoon (Department of Otorhinolaryngology, Yonsei University College of Medicine) ;
  • Moon, Seok-Jun (Department of Oral biology, Yonsei University, College of Dentistry)
  • Received : 2012.05.15
  • Accepted : 2012.06.19
  • Published : 2012.06.30
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Abstract

The nasal cavity encounters various irritants during inhalation such as dust and pathogens. To detect and remove these irritants, it has been postulated that the nasal mucosa epithelium has a specialized sensing system. The oral cavity, on the other hand, is known to have bitter taste receptors (T2Rs) that can detect harmful substances to prevent ingestion. Recently, solitary chemosensory cells expressing T2R subtypes have been found in the respiratory epithelium of rodents. In addition, T2Rs have been identified in the human airway epithelia. However, it is not clear which T2Rs are expressed in the human nasal mucosa epithelium and whether they mediate the removal of foreign materials through increased cilia movement. In our current study, we show that human T2R receptors indeed function also in the nasal mucosa epithelium. Our RT-PCR data indicate that the T2R subtypes (T2R3, T2R4, T2R5, T2R10, T2R13, T2R14, T2R39, T2R43, T2R44, T2R 45, T2R46, T2R47, T2R48, T2R49, and T2R50) are expressed in human nasal mucosa. Furthermore, we have found that T2R receptor activators such as bitter chemicals augments the ciliary beating frequency. Our results thus demonstrate that T2Rs are likely to function in the cleanup of inhaled dust and pathogens by increasing ciliary movement. This would suggest that T2Rs are feasible molecular targets for the development of novel treatment strategies for nasal infection and inflammation.

Keywords

References

  1. Chandrashekar J, Hoon MA, Ryba NJ, Zuker CS. The receptors and cells for mammalian taste. Nature. 2006;444:288-94.
  2. Wu SV, Chen MC, Rozengurt E. Genomic organization, expression, and function of bitter taste receptors (T2R) in mouse and rat. Physiol Genomics. 2005;22:139-49.
  3. Wu SV, Rozengurt N, Yang M, Young SH. Sinnett-Smith J, Rozengurt E. Expression of bitter taste receptors of the T2R family in the gastrointestinal tract and enteroendocrine STC-1 cells. Proc Natl Acad Sci USA. 2002;99:2392-97.
  4. Finger TE, Bottger B, Hansen A, Anderson KT, Alimohammadi H, Silver WL. Solitary chemoreceptor cells in the nasal cavity serve as sentinels of respiration. Proc Natl Acad Sci USA. 2003;100:8981-6.
  5. Singh N, Vrontakis M, Parkinson F, Chelikani P. Functional bitter taste receptors are expressed in brain cells. Biochem Biophys Res Commun. 2011;406:146-51.
  6. Jun Y, Kim S, Lee C, Cho Y, Chung K, Roper SD, Kim K. Distribution of taste receptors in submandibular and von Ebner salivary glands. Int J Oral Biol. 2008;33(1):13-22.
  7. Shah AS, Ben-Shahar Y, Moninger TO, Kline JN, Welsh MJ. Motile cilia of human airway epithelia are chemosensory. Science. 2009;325:1131-34.
  8. Deshpande DA, Wang WC, McIlmoyle EL, Robinett KS, Schillinger RM, An SS, Sham JS, Liggett SB. Bitter taste receptors on airway smooth muscle bronchodilate by localized calcium signaling and reverse obstruction. Nat Med. 2010;16:1299-304.
  9. Kim WJ, Han TH, Kim HJ, Park RW. Optical flow techniques with peak detection method for ciliary beat frequency measurement. AMIA Annu Symp Proc. 2007;1069.
  10. Merigo F, Benati D, Di Chio M, Osculati F, Sbarbati A. Secretory cells of the airway express molecules of the chemoreceptive cascade. Cell Tissue Res. 2007;327:231-47.
  11. Braun T, Mack B, Kramer MF. Solitary chemosensory cells in the respiratory and vomeronasal epithelium of the human nose: a pilot study. Rhinology. 2011;49:507-12.
  12. Gulbransen BD, Clapp TR, Finger TE, Kinnamon SC. Nasal solitary chemoreceptor cell responses to bitter and trigerminal stimulants in vitro. J Neurophysiol. 2008;99:2929-37.
  13. Tizzano M, Gulbransen BD, Vandenbeuch A, Clapp TR, Herman JP, Sibhatu HM, Churchill ME, Silver WL, Kinnamon SC, Finger TE. Nasal chemosensory cells use bitter taste signaling to detect irritants and bacterial signals. Proc Natl Acad Sci USA. 2010;107:3210-5.
  14. Braiman A, Prielb Z. Efficient mucociliary transport relies on efficient regulation of ciliary beating. Respir Physiol Neurobiol. 2008;163:202-7.