title: Requirement of cellular prion protein for intestinal barrier function and mislocalization in patients with inflammatory bowel disease.
abstract: OBJECTIVE
  Cell adhesion is one function regulated by cellular prion protein (PrP(c)), a ubiquitous, glycosylphosphatidylinositol-anchored glycoprotein. PrP(c) is located in cell-cell junctions and interacts with desmosome proteins in the intestinal epithelium. We investigated its role in intestinal barrier function.
  
  
  METHODS
  We analyzed permeability and structure of cell-cell junctions in intestine tissues from PrP(c) knockout (PrP(c-/-)) and wild-type mice. PrP(c) expression was knocked down in cultured human Caco-2/TC7 enterocytes using small hairpin RNAs. We analyzed colon samples from 24 patients with inflammatory bowel disease (IBD).
  
  
  RESULTS
  Intestine tissues from PrP(c-/-) mice had greater paracellular permeability than from wild-type mice (105.9 ± 13.4 vs 59.6 ± 10.1 mg/mL fluorescein isothiocyanate-dextran flux; P < .05) and impaired intercellular junctions. PrP(c-/-) mice did not develop spontaneous disease but were more sensitive than wild-type mice to induction of colitis with dextran sulfate (32% mortality vs 4%, respectively; P = .0033). Such barrier defects were observed also in Caco-2/TC7 enterocytes following PrP(c) knockdown; the cells had increased paracellular permeability (1.5-fold over 48 hours; P < .001) and reduced transepithelial electrical resistance (281.1 ± 4.9 vs 370.6 ± 5.7 Ω.cm(2); P < .001). Monolayer shape and cell-cell junctions were altered in cultures of PrP(c) knockdown cells; levels of E-cadherin, desmoplakin, plakoglobin, claudin-4, occludin, zonula occludens 1, and tricellulin were decreased at cell contacts. Cell shape and junctions were restored on PrP(c) re-expression. Levels of PrP(c) were decreased at cell-cell junctions in colonic epithelia from patients with Crohn's disease or ulcerative colitis.
  
  
  CONCLUSIONS
  PrP(c) regulates intestinal epithelial cell-cell junctions and barrier function. Its localization is altered in colonic epithelia from patients with IBD, supporting the concept that disrupted barrier function contributes to this disorder.
authors.affiliation: Centre de Recherche des Cordeliers, Université Pierre et Marie Curie-Paris 6, Paris, France.
authors.forename: Constance S V
authors.initials: CS
authors.lastname: Petit
authors.forename: Frédérick
authors.initials: F
authors.lastname: Barreau
authors.forename: Laura
authors.initials: L
authors.lastname: Besnier
authors.forename: Pierre
authors.initials: P
authors.lastname: Gandille
authors.forename: Béatrice
authors.initials: B
authors.lastname: Riveau
authors.forename: Danielle
authors.initials: D
authors.lastname: Chateau
authors.forename: Maryline
authors.initials: M
authors.lastname: Roy
authors.forename: Dominique
authors.initials: D
authors.lastname: Berrebi
authors.forename: Magali
authors.initials: M
authors.lastname: Svrcek
authors.forename: Philippe
authors.initials: P
authors.lastname: Cardot
authors.forename: Monique
authors.initials: M
authors.lastname: Rousset
authors.forename: Caroline
authors.initials: C
authors.lastname: Clair
authors.forename: Sophie
authors.initials: S
authors.lastname: Thenet
mesh_terms: D000818:Animals; D002463:Cell Membrane Permeability / Q000502:physiology; D002478:Cells, Cultured; D003106:Colon / Q000378:metabolism; D020895:Enterocytes / Q000378:metabolism; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000378:metabolism*; D007365:Intercellular Junctions / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D018621:PrPC Proteins / Q000378:metabolism*
chemical_list: D018621:PrPC Proteins