title: Enterocytic differentiation is modulated by lipid rafts-dependent assembly of adherens junctions.
abstract: Integrity of the epithelial barrier is determined by apical junctional complexes which also participate in the signalling pathways inducing intestinal cell differentiation. Lipid rafts (LR) have been proposed to play a role in the organization and the function of these intercellular complexes. This study investigated potential mechanisms by which LR could participate in the establishment of adherens junctions (AJ) and the initiation of enterocytic differentiation. We showed that the differentiation of epithelial cells in rat colons correlates with the emergence of LR. Using HT-29 cells we demonstrated that during the differentiation process, LR are required for the recruitment and the association of p120ctn to E-cadherin. Silencing of flotillin-1, a LR component, alters the recruitment of AJ proteins in LR and delays the expression of differentiation markers. Furthermore, the ability of p120ctn/E-cadherin complexes to support cell differentiation is altered in HT-29 Rac1N17 cells. These results show a contributory role of LR in the enterocytic differentiation process, which serve as signalling platforms for Rac1-mediated organization of AJ. A better understanding of the mechanism involved in the establishment of junctional complex and their role in enterocytic differentiation provides new insights into the regulation of intestinal homeostasis.
authors.affiliation: Centre de Recherche Inserm U823, Institut Albert Bonniot, Equipe de Dynamique des Systèmes d'Adhérence et de Différenciation, Site Santé BP 170 La Tronche F-38042 Grenoble Cedex 9, France.
authors.forename: Nicolas T
authors.initials: NT
authors.lastname: Chartier
authors.forename: Michèle G
authors.initials: MG
authors.lastname: Lainé
authors.forename: Benjamin
authors.initials: B
authors.lastname: Ducarouge
authors.forename: Christiane
authors.initials: C
authors.lastname: Oddou
authors.forename: Bruno
authors.initials: B
authors.lastname: Bonaz
authors.forename: Corinne
authors.initials: C
authors.lastname: Albiges-Rizo
authors.forename: Muriel R
authors.initials: MR
authors.lastname: Jacquier-Sarlin
mesh_terms: D022005:Adherens Junctions / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism*; D002454:Cell Differentiation; D049109:Cell Proliferation; D020895:Enterocytes / Q000166:cytology*; D005455:Fluorescent Antibody Technique; D019073:HT29 Cells; D006801:Humans; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D021962:Membrane Microdomains / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051381:Rats; D020729:p120 GTPase Activating Protein / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
chemical_list: D015820:Cadherins; D008565:Membrane Proteins; C106354:flotillins; D020729:p120 GTPase Activating Protein; D020830:rac1 GTP-Binding Protein