title: E- and N-cadherin distribution in developing and functional human teeth under normal and pathological conditions.
abstract: Cadherins are calcium-dependent cell adhesion molecules involved in the regulation of various biological processes such as cell recognition, intercellular communication, cell fate, cell polarity, boundary formation, and morphogenesis. Although previous studies have shown E-cadherin expression during rodent or human odontogenesis, there is no equivalent study available on N-cadherin expression in dental tissues. Here we examined and compared the expression patterns of E- and N-cadherins in both embryonic and adult (healthy, injured, carious) human teeth. Both proteins were expressed in the developing teeth during the cap and bell stages. E-cadherin expression in dental epithelium followed an apical-coronal gradient that was opposite to that observed for N-cadherin. E-cadherin was distributed in proliferating cells of the inner and outer enamel epithelia but not in differentiated cells such as ameloblasts, whereas N-cadherin expression was up-regulated in differentiated epithelial cells. By contrast to E-cadherin, N-cadherin was also expressed in mesenchymal cells that differentiate into odontoblasts and produce the hard tissue matrix of dentin. Although N-cadherin was not detected in permanent intact teeth, it was re-expressed during dentin repair processes in odontoblasts surrounding carious or traumatic sites. Similarly, N-cadherin re-expression was seen in vitro, in cultured primary pulp cells that differentiate into odontoblast-like cells. Taken together these results suggest that E- and N-cadherins may play a role during human tooth development and, moreover, indicate that N-cadherin is important for odontoblast function in normal development and under pathological conditions.
authors.affiliation: Faculté d'Odontologie de Marseille, Université de la Méditerranée, Marseille, France.
authors.forename: Robert
authors.initials: R
authors.lastname: Heymann
authors.forename: Imad
authors.initials: I
authors.lastname: About
authors.forename: Urban
authors.initials: U
authors.lastname: Lendahl
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Franquin
authors.forename: Björn
authors.initials: B
authors.lastname: Obrink
authors.forename: Thimios A
authors.initials: TA
authors.lastname: Mitsiadis
mesh_terms: D000293:Adolescent; D000328:Adult; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D015820:Cadherins / Q000096:biosynthesis / Q000502:physiology*; D002478:Cells, Cultured; D003731:Dental Caries / Q000378:metabolism; D003782:Dental Pulp / Q000166:cytology / Q000378:metabolism; D005260:Female; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D006801:Humans; D009805:Odontogenesis / Q000187:drug effects; D011247:Pregnancy; D018677:Tooth Injuries / Q000378:metabolism
chemical_list: C525809:BMP4 protein, human; D055415:Bone Morphogenetic Protein 4; D019485:Bone Morphogenetic Proteins; D015820:Cadherins; C112971:fibroblast growth factor 14; D005346:Fibroblast Growth Factors