title: Upper airway mucin gene expression: a review.
abstract: BACKGROUND
  The gel-like properties of mucus depend primarily on its content of mucins. The protein backbones of mucins are encoded by mucin genes. Of the currently known 20 mucin genes that encode protein backbone of mucins, 16 have been identified in the airways.
  
  
  METHODS
  We explored the current knowledge about upper airway mucin expression in health and disease conditions using a Medline search. We have also studied upper airway mucin gene expression and compared our results with the results from other studies.
  
  
  RESULTS
  MUC5AC, MUC5B, and MUC2 are the principal gel-forming mucins secreted in the airway. However, the spectrum of mucin expression in chronic upper airway diseases such as nasal polyps, chronic sinusitis, middle ear effusion, and cystic fibrosis is generally wide and variable.
  
  
  CONCLUSIONS
  The wide spectrum of upper airway mucin expression is possibly caused by various anatomic and histologic features as well as physiologic and pathologic variables. These variables have not been fully explored yet, and the majority of airway mucin expression studies used small numbers of samples.
  
  
  CONCLUSIONS
  Studies including adequate numbers of samples (patients) are more likely to reveal a clearer profile and more precise expression patterns. Generating a clear profile of mucin expression patterns in health and disease requires the analysis of different variables, which can alter that expression. It is also essential to understand the various molecular mechanisms controlling mucin gene and protein expression. This could lead to the invention of novel therapeutic modalities to treat upper airway diseases.
authors.affiliation: Epithelial Group, Institute for Cell and Molecular Biosciences, The Medical School, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne, United Kingdom. msamomar@yahoo.co.uk
authors.forename: Mahmoud S
authors.initials: MS
authors.lastname: Ali
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Pearson
mesh_terms: D004848:Epithelium; D015870:Gene Expression; D006801:Humans; D009077:Mucins / Q000235:genetics*; D009297:Nasal Mucosa / Q000378:metabolism*; D010256:Paranasal Sinuses / Q000378:metabolism*
chemical_list: D009077:Mucins