title: Down-regulation of carbonic anhydrase isoenzymes in nasal polyps.
abstract: OBJECTIVE
  Carbonic anhydrase (CA) is a zinc metalloenzyme that participate in the biological processes of various fluid transporting epithelia, including ion and water transport. CA may thus play a role in the pathophysiology of normal nasal mucosa and nasal polyp. We evaluated the expression and pattern of distribution of mRNAs and proteins for CA isoenzymes in normal nasal mucosa and polyps.
  
  
  METHODS
  This was a controlled, prospective study.
  
  
  METHODS
  The expression levels of 11 isoenzyme genes (I, II, III, IV, VA, VB, VI, VII, IX, XII, XIV) were evaluated in normal mucosa and polyps using semiquantitative reverse-transcriptase polymerase chain reaction. The expression and pattern of distribution of CA I, II, and IX were also investigated using immunohistochemistry and Western blot.
  
  
  RESULTS
  mRNAs for the 11 CA isoenzymes were detected in all normal nasal mucosa and polyps tested. Their expression levels were decreased in nasal polyp in comparison with normal nasal mucosa. CA I was detected in the epithelial cells, endothelial cells, and submucosal gland of normal nasal mucosa, but only in the endothelial cells in nasal polyp. CA II in normal mucosa was intensely expressed in the submucosal gland cells and CA IX was noted in the cytoplasm and plasma membrane of epithelial cells and submucosal glands. However, these findings were not found in nasal polyp. Western blot also showed differences in their expression levels.
  
  
  CONCLUSIONS
  These results indicate that CA may participate in the physiology of normal nasal mucosa, but also suggest that altered their expression in nasal polyps may cause impaired electrolyte and water transport across the epithelial cells.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, College of Medicine, Korea University, Seoul, South Korea.
authors.forename: Tae Hoon
authors.initials: TH
authors.lastname: Kim
authors.forename: Heung Man
authors.initials: HM
authors.lastname: Lee
authors.forename: Seung Hoon
authors.initials: SH
authors.lastname: Lee
authors.forename: Ha Kyun
authors.initials: HK
authors.lastname: Kim
authors.forename: Jung Hoon
authors.initials: JH
authors.lastname: Lee
authors.forename: Kyoung Ho
authors.initials: KH
authors.lastname: Oh
authors.forename: Sang Hag
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000328:Adult; D002256:Carbonic Anhydrases / Q000378:metabolism*; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000201:enzymology; D009298:Nasal Polyps / Q000201:enzymology*
chemical_list: D007527:Isoenzymes; D002256:Carbonic Anhydrases