title: Localization and expression of TRPV1 and TRPA1 in the human oropharynx and larynx.
abstract: BACKGROUND
  Previous studies have found that TRPV1 and TRPA1 receptor agonists improve swallow response in patients with oropharyngeal dysphagia (OD), but little is known about the expression of these receptors in the human oropharynx. The aim of this study was to assess the expression and localization of TRPV1 and TRPA1 in human samples from the oropharynx of healthy patients, to provide the basis for new pharmacological treatments for OD.
  
  
  METHODS
  Samples from oropharyngeal regions innervated by cranial nerves V, IX, and X (tongue, pharynx, and epiglottis) were obtained during ENT surgery and processed either for mRNA (21 patients) or for immunohistochemical assays (seven patients). The expression analysis was performed with RT-qPCR using ACTBh as reference gene. Hemotoxylin and eosin staining was used to study the histology; the immunohistochemical assay used (i) neuron-specific enolase to detect nerve fibers or (ii) fluorescent probes to locate TRPV1 and TRPA1.
  
  
  RESULTS
  TRPV1 was expressed in the three studied regions, with higher levels in CN V region (tongue) than in CN X region (epiglottis; p < 0.05), and was localized at epithelial cells and nociceptive fibers in all studied regions. TRPA1 was also expressed in all studied regions, but was always localized below the basal lamina. No immunoreactivity for TRPA1 was found on epithelial cells.
  
  
  CONCLUSIONS
  TRPV1 and TRPA1 are widely expressed in the human oropharynx with two distinct patterns. Our study further confirms that TRPV1/A1 receptors are promising therapeutic targets to develop active treatments for OD patients.
authors.affiliation: Gastrointestinal Motility Laboratory, Hospital de Mataró, Consorci Sanitari del Maresme, Mataró, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Alvarez-Berdugo
authors.affiliation: Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, Barcelona, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Rofes
authors.affiliation: Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, Barcelona, Spain.|Translational Research Center for Gastrointestinal Disorders, KU Leuven - University of Leuven, Leuven, Belgium.
authors.forename: R
authors.initials: R
authors.lastname: Farré
authors.affiliation: ENT Department, Hospital de Mataró, Consorci Sanitari del Maresme, Mataró, Spain.
authors.forename: J F
authors.initials: JF
authors.lastname: Casamitjana
authors.affiliation: ENT Department, Hospital de Mataró, Consorci Sanitari del Maresme, Mataró, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Enrique
authors.affiliation: ENT Department, Hospital de Mataró, Consorci Sanitari del Maresme, Mataró, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Chamizo
authors.affiliation: Department of Pathology, Hospital de Mataró, Consorci Sanitari del Maresme, Mataró, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Padrón
authors.affiliation: Department of Cell Biology, Physiology and Immunology, Institute of Neurosciences, Universitat Autònoma de Barcelona, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas, Bellaterra, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Navarro
authors.affiliation: Gastrointestinal Motility Laboratory, Hospital de Mataró, Consorci Sanitari del Maresme, Mataró, Spain.|Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas, Instituto de Salud Carlos III, Barcelona, Spain.|Fundació Institut de Investigació Germans Trias i Pujol, Badalona, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Clavé
mesh_terms: D000328:Adult; D000368:Aged; D001485:Basement Membrane; D015220:Calcium Channels / Q000235:genetics* / Q000378:metabolism; D003680:Deglutition Disorders / Q000235:genetics / Q000378:metabolism; D004825:Epiglottis / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007830:Larynx / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism; D009619:Nociceptors / Q000378:metabolism; D009960:Oropharynx / Q000378:metabolism*; D010614:Pharynx / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D000074025:TRPA1 Cation Channel; D050916:TRPV Cation Channels / Q000235:genetics* / Q000378:metabolism; D014059:Tongue / Q000378:metabolism*; D050051:Transient Receptor Potential Channels / Q000235:genetics* / Q000378:metabolism
chemical_list: D015220:Calcium Channels; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D000074025:TRPA1 Cation Channel; C473350:TRPA1 protein, human; D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; D050051:Transient Receptor Potential Channels
keywords: Ankyrin-like with transmembrane domains protein 1; oropharyngeal dysphagia; sensory input; vanilloid receptor 1