The cell adhesion molecule nectin-1 is critical for normal enamel formation in mice.
Nectin-1 is a member of a sub-family of immunoglobulin-like adhesion molecules and a component of adherens junctions. In the current study, we have shown that mice lacking nectin-1 exhibit defective enamel formation in their incisor teeth. Although the incisors of nectin-1-null mice were hypomineralized, the protein composition of the enamel matrix was unaltered. While strong immunostaining for nectin-1 was observed at the interface between the maturation-stage ameloblasts and the underlying cells of the stratum intermedium (SI), its absence in nectin-1-null mice correlated with separation of the cell layers at this interface. Numerous, large desmosomes were present at this interface in wild-type mice; however, where adhesion persisted in the mutant mice, the desmosomes were smaller and less numerous. Nectins have been shown to regulate tight junction formation; however, this is the first report showing that they may also participate in the regulation of desmosome assembly. Importantly, our results show that integrity of the SI-ameloblast interface is essential for normal enamel mineralization.
Barron
Martin J
MJ
Faculty of Life Sciences, University of Manchester, Manchester, UK.
Brookes
Steven J
SJ
Draper
Clare E
CE
Garrod
David
D
Kirkham
Jennifer
J
Shore
Roger C
RC
Dixon
Michael J
MJ
D022005:Adherens Junctions / Q000378:metabolism; D000565:Ameloblasts / Q000166:cytology / Q000502:physiology; D000566:Amelogenesis; D000818:Animals; D017209:Apoptosis; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation; D003743:Dental Enamel / Q000737:chemistry / Q000378:metabolism*; D003746:Dental Enamel Proteins / Q000032:analysis; D051180:Desmoplakins / Q000032:analysis; D003896:Desmosomes / Q000378:metabolism* / Q000648:ultrastructure; D004658:Enamel Organ / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D005290:Ferric Compounds / Q000378:metabolism; D007150:Immunohistochemistry; D007180:Incisor / Q000002:abnormalities / Q000000981:diagnostic imaging; D051379:Mice; D008822:Mice, Transgenic; D008850:Microphthalmos; D046529:Microscopy, Electron, Transmission; D000075983:Nectins; D011859:Radiography; D019108:Tight Junctions / Q000378:metabolism / Q000648:ultrastructure
D015815:Cell Adhesion Molecules; D003746:Dental Enamel Proteins; D051180:Desmoplakins; D005290:Ferric Compounds; C000619015:Nectin1 protein, mouse; D000075983:Nectins; C109069:enamel matrix proteins