title: Aquaporin expression profiles in normal sinonasal mucosa and chronic rhinosinusitis.
abstract: BACKGROUND
  Thickened secretions, mucosal edema, and polyp formation are pathological features in chronic rhinosinusitis (CRS) that could theoretically be caused by aberrant water flow through sinonasal mucosa. Aquaporins (AQPs) are a family of proteins with roles in water transport, with tissue-specific expression profiles. This study aims to determine if AQP expression in sinonasal mucosa is different between normal controls and patients with CRS, either with (CRSwNP) or without (CRSsNP) nasal polyps.
  
  
  METHODS
  During endoscopic sinus surgery or transsphenoidal surgery, sinonasal tissue was collected and classified as CRSwNP (n = 13), CRSsNP (n = 10), or normal (n = 10). Messenger RNA (mRNA) expression of human AQP0 to AQP12b was determined using quantitative real-time polymerase chain reaction (qRT-PCR). Cellular localization of AQP1, AQP3, AQP4, AQP5, AQP7, and AQP11 was determined by immunohistochemistry.
  
  
  RESULTS
  mRNA of AQP0 to AQP11 was identified in all samples. AQP12b mRNA was not detected. Significant differences in the mRNA expression levels of AQP4 and AQP11 were identified between normal and CRSwNP patients (p < 0.05). Differences in the cellular localization of AQPs were observed in both CRSsNP and CRSwNP patients vs normal controls. More intense localization to the cell cytoplasm was observed for AQP5 in glandular epithelium (CRSwNP; p < 0.05) and surface epithelium (CRSsNP; p < 0.05), and AQP4 in glandular epithelium (CRSsNP; p < 0.05).
  
  
  CONCLUSIONS
  This study characterized AQP mRNA expression and protein localization in normal human sinonasal tissue. Significant differences in mRNA expression were found for AQP4 and AQP11 in CRSwNP and differences in protein localization patterns of AQP4 and AQP5 were identified in both types of CRS.
authors.affiliation: Department of Surgery, Flinders Medical Centre and Flinders University, Adelaide, South Australia, Australia.
authors.forename: Claire
authors.initials: C
authors.lastname: Frauenfelder
authors.forename: Charmaine
authors.initials: C
authors.lastname: Woods
authors.forename: Damian
authors.initials: D
authors.lastname: Hussey
authors.forename: Eng
authors.initials: E
authors.lastname: Ooi
authors.forename: Sonja
authors.initials: S
authors.lastname: Klebe
authors.forename: A Simon
authors.initials: AS
authors.lastname: Carney
mesh_terms: D020346:Aquaporins / Q000378:metabolism*; D016022:Case-Control Studies; D002908:Chronic Disease; D006801:Humans; D007150:Immunohistochemistry; D009297:Nasal Mucosa / Q000378:metabolism; D009298:Nasal Polyps / Q000150:complications; D010256:Paranasal Sinuses / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D012220:Rhinitis / Q000150:complications / Q000175:diagnosis*; D012852:Sinusitis / Q000150:complications / Q000175:diagnosis*
chemical_list: D020346:Aquaporins; D012333:RNA, Messenger
keywords: PCR; aquaporin; immunohistochemistry; nasal mucosa; nasal polyps; paranasal sinuses; rhinitis; sinusitis