title: Differential expression of the integrins alpha6Abeta4 and alpha6Bbeta4 along the crypt-villus axis in the human small intestine.
abstract: The integrin alpha6 subunit exists as two different variants, termed alpha6A and alpha6B. These two variants have been shown to harbor potentially distinct biochemical properties but little is known about their cellular function. The aim of this work was to characterize the expression of the integrin alpha6A and B variants in relation to cell proliferation and differentiation in the human small intestinal epithelium. The results showed distinct expression patterns for the two variants along the crypt-villus axis. Indeed, proliferative cells of the crypt were found to predominantly express alpha6A, while differentiated enterocytes and Paneth cells expressed the alpha6B variant. A similar relationship was observed in intestinal cell models by competitive RT-PCR. Further studies in the Caco-2 cell model showed that manipulating the cellular balance of the two alpha6 variants can influence transcriptional activities related to cell proliferation but not differentiation. This suggests that differential expression of the alpha6 subunits is involved in the intestinal epithelial cell renewal process. Further studies will be needed to substantiate this hypothesis.
authors.affiliation: CIHR Team on the Digestive Epithelium, Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, QC J1H5N4, Canada.
authors.forename: Anders Bondo
authors.initials: AB
authors.lastname: Dydensborg
authors.forename: Inga C
authors.initials: IC
authors.lastname: Teller
authors.forename: Nuria
authors.initials: N
authors.lastname: Basora
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Groulx
authors.forename: Joëlle
authors.initials: J
authors.lastname: Auclair
authors.forename: Caroline
authors.initials: C
authors.lastname: Francoeur
authors.forename: Fabrice
authors.initials: F
authors.lastname: Escaffit
authors.forename: Fréderic
authors.initials: F
authors.lastname: Paré
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Herring
authors.forename: Daniel
authors.initials: D
authors.lastname: Ménard
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Beaulieu
mesh_terms: D018938:Caco-2 Cells; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D006801:Humans; D039503:Integrin alpha6 / Q000378:metabolism*; D039663:Integrin beta4 / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D007421:Intestine, Small / Q000166:cytology / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism
chemical_list: D039503:Integrin alpha6; D039663:Integrin beta4; D020033:Protein Isoforms