title: Expression of Claudin-2 in intestinal metaplastic mucosa of Cdx2-transgenic mouse stomach.
abstract: OBJECTIVE
  Cdx2 is expressed in human intestinal metaplastic mucosa and induces intestinal metaplastic mucosa in Cdx2-transgenic mouse stomach. Claudin-2 is a structural component of tight junctions in the intestine and Cdx2 activates the Claudin-2 promoter in the human intestinal epithelial cell line Caco-2. Our aim is to evaluate the expression of Claudin-2 in intestinal metaplastic mucosa of Cdx2-transgenic mouse stomach.
  
  
  METHODS
  The Claudin-2 expression in the normal gastric mucosa and normal intestinal mucosa of wild type mice and the intestinal metaplastic mucosa of Cdx2-transgenic mice was analyzed by immunohistochemistry, Western blotting and quantitative real-time PCR (qRT-PCR).
  
  
  RESULTS
  Claudin-2 was expressed in the base of the glands in intestine and intestinal metaplasia while it was not expressed in the body of stomach. Claudin-2 expression was found in the antrum of stomach, while it was weaker than that in the intestine and the intestinal metaplasia. Claudin-2 was also detected in intestinal metaplasia, colon and ileum by both Western blotting and qRT-PCR while it was not detected in gastric body.
  
  
  CONCLUSIONS
  These results suggest that Cdx2 plays an important role in the expression of Claudin-2 in vivo.
authors.affiliation: Department of Medicine, Division of Gastroenterology, Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mutoh
authors.forename: Kentaro
authors.initials: K
authors.lastname: Sugano
mesh_terms: D000818:Animals; D015153:Blotting, Western; D000071616:CDX2 Transcription Factor; D057167:Claudins; D003106:Colon / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D005753:Gastric Mucosa / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics*; D007082:Ileum / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology; D007583:Jejunum / Q000378:metabolism / Q000473:pathology; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D008679:Metaplasia; D051379:Mice; D008822:Mice, Transgenic; D016133:Polymerase Chain Reaction; D011706:Pyloric Antrum / Q000378:metabolism* / Q000473:pathology; D012313:RNA / Q000235:genetics*; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D000071616:CDX2 Transcription Factor; C487514:Cdx2 protein, mouse; D057167:Claudins; C113371:Cldn2 protein, mouse; D018398:Homeodomain Proteins; D008565:Membrane Proteins; D014157:Transcription Factors; D012313:RNA