title: Histamine downregulates aquaporin 5 in human nasal epithelial cells.
abstract: BACKGROUND
  Aquaporin 5 (AQP5) is a water-specific channel protein. It is thought to be a key participant in fluid secretion and a rate-limiting barrier to the secretion seen during allergic inflammation. We sought to determine the effect of histamine on AQP5 expression in human nasal epithelial cells (HNEpC).
  
  
  METHODS
  HNEpC cells were cultured with four concentrations of histamine in vitro. The phosphorylation of cyclic adenosine monophosphate-responsive element binding protein (CREB) at serine 133 and the AQP5 protein were measured by using immunocytochemistry and Western blotting. Real-time polymerase chain reaction was used to detect AQP5 messenger ribonucleic acid (mRNA).
  
  
  RESULTS
  Concentration-dependent histamine induced-inhibition of CREB phosphorylation at serine 133 in HNEpC cells was observed, and AQP5 mRNA and protein were also downregulated in a concentration-dependent fashion.
  
  
  CONCLUSIONS
  Histamine downregulates AQP5 production in HNEpC cells by inhibiting CREB phosphorylation at serine 133.
authors.affiliation: Department of Anatomy, Schools of Medicine and Nursing Sciences, Huzhou University, China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Wang
authors.forename: Xiaolian
authors.initials: X
authors.lastname: Wang
authors.forename: Lan
authors.initials: L
authors.lastname: Ma
authors.forename: Ruitao
authors.initials: R
authors.lastname: Zhang
mesh_terms: D051402:Aquaporin 5; D050882:CREB-Binding Protein / Q000502:physiology; D015536:Down-Regulation / Q000502:physiology*; D006632:Histamine / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D012333:RNA, Messenger / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction
chemical_list: C496036:AQP5 protein, human; D051402:Aquaporin 5; D012333:RNA, Messenger; D006632:Histamine; D050882:CREB-Binding Protein