title: Niflumic Acid Reduces Histamine-Induced MUC5AC Expression in Human Conjunctival Epithelial Cells.
abstract: OBJECTIVE
  Histamine is an important inflammatory mediator in allergic conjunctivitis. The aim of the present study was to explore whether histamine induced MUC5AC production in human conjunctival epithelial cells (HCECs), and to describe the relationship between human calcium-activated chloride channel 1 (hCLCA1) activity and MUC5AC expression.
  
  
  METHODS
  HCECs were isolated from human conjunctiva and cultured at an air-liquid interface. MUC5AC and hCLCA1 mRNA expression was examined by real-time PCR after exposure of the cells to histamine. MUC5AC secretion was quantitated by ELISA. hCLCA1 protein was detected by Western blot analysis.
  
  
  RESULTS
  Histamine upregulated MUC5AC expression and MUC5AC secretion in a dose-dependent manner. Histamine also upregulated hCLCA1 mRNA expression in a dose-dependent manner. Preincubation of histamine receptor 1 antagonist reduced histamine-induced MUC5AC and hCLCA1 mRNA expression. Niflumic acid, a chloride channel inhibitor, reduced histamine-induced MUC5ACand hCLCA1 expression.
  
  
  CONCLUSIONS
  Histamine-induced MUC5AC production could be decreased by niflumic acid, a calcium-activated chloride channel inhibitor.
authors: Department of Ophthalmology, Institute of Vision Research, Yonsei University College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors: Kyoung Yul
authors: KY
authors: Seo
authors: Sohee
authors: S
authors: Jeon
authors: Seong Hyun
authors: SH
authors: Choi
authors: So-Hyang
authors: SH
authors: Chung
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D015153:Blotting, Western; D002478:Cells, Cultured; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000378:metabolism; D003228:Conjunctiva / Q000166:cytology*; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects*; D006632:Histamine / Q000494:pharmacology*; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D006801:Humans; D055271:Mucin 5AC / Q000235:genetics* / Q000378:metabolism; D009544:Niflumic Acid / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D011968:Receptors, Histamine / Q000235:genetics
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; C492109:CLCA1 protein, human; D018118:Chloride Channels; D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D012333:RNA, Messenger; D011968:Receptors, Histamine; D009544:Niflumic Acid; D006632:Histamine