title: Neuronal NOS localises to human airway cilia.
abstract: BACKGROUND
  Airway NO synthase (NOS) isoenzymes are responsible for rapid and localised nitric oxide (NO) production and are expressed in airway epithelium. We sought to determine the localisation of neuronal NOS (nNOS) in airway epithelium due to the paucity of evidence.
  
  
  RESULTS
  Sections of healthy human bronchial tissue in glycol methacrylate resin and human nasal polyps in paraffin wax were immunohistochemically labelled and reproducibly demonstrated nNOS immunoreactivity, particularly at the proximal portion of cilia; this immunoreactivity was blocked by a specific nNOS peptide fragment. Healthy human epithelial cells differentiated at an air-liquid interface (ALI) confirmed the presence of all three NOS isoenzymes by immunofluorescence labelling. Only nNOS immunoreactivity was specific to the ciliary axonemeand co-localised with the cilia marker β-tubulin in the proximal part of the ciliary axoneme.
  
  
  CONCLUSIONS
  We report a novel localisation of nNOS at the proximal portion of cilia in airway epithelium and conclude that its independent and local regulation of NO levels is crucial for normal cilia function.
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK; Primary Ciliary Dyskinesia Centre, NIHR Southampton Respiratory Biomedical Research Unit, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK. Electronic address: clj@soton.ac.uk.
authors.forename: Claire L
authors.initials: CL
authors.lastname: Jackson
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK; Primary Ciliary Dyskinesia Centre, NIHR Southampton Respiratory Biomedical Research Unit, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Jane S
authors.initials: JS
authors.lastname: Lucas
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK; Primary Ciliary Dyskinesia Centre, NIHR Southampton Respiratory Biomedical Research Unit, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Woolf T
authors.initials: WT
authors.lastname: Walker
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Holly
authors.initials: H
authors.lastname: Owen
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
authors.forename: Irnthu
authors.initials: I
authors.lastname: Premadeva
authors.affiliation: Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK; Primary Ciliary Dyskinesia Centre, NIHR Southampton Respiratory Biomedical Research Unit, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Lackie
mesh_terms: D001980:Bronchi / Q000737:chemistry / Q000201:enzymology; D002478:Cells, Cultured; D002923:Cilia / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D009298:Nasal Polyps / Q000737:chemistry / Q000201:enzymology; D052248:Nitric Oxide Synthase Type I / Q000737:chemistry / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000737:chemistry / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism
chemical_list: C496320:NOS1 protein, human; D052248:Nitric Oxide Synthase Type I
keywords: Airway; Cilia; EC 1.14.13.39; Epithelium; NOS; nNOS