Expression of collagen XVIII and MMP-20 in developing teeth and odontogenic tumors.
Collagen XVIII is a basement membrane (BM) component, whereas MMP-20 (enamelysin) is a matrix metalloproteinase predominantly expressed in teeth. Since MMP-20 was found to degrade collagen XVIII, we studied the co-expression of these proteins in dental tissues. Collagen XVIII surrounded the developing tooth during early and late bell stages and was also present in developing enamel. Western blotting indicated that developing enamel contains collagen XVIII N-terminal fragments of the frizzled variant. Enamelysin was co-localized with collagen XVIII in the developing enamel matrix and stratum intermedium. Electron microscope analysis showed that total mineral, calcium and phosphorus contents of enamel were slightly increased in collagen XVIII null mice but the analysis revealed no visible defects in the enamel or dentin structures. In odontogenic tumors MMP-20 and collagen XVIII were co-localized in the enamel-like tumor matrix. Our results show that collagen XVIII is present in developing teeth, but its absence seems not to be critical for the development of the teeth.
Department of Diagnostics and Oral Medicine, Institute of Dentistry, University of Oulu, P.O. Box 5281, 90014 Oulu, Finland.
Anu
A
Väänänen
Leo
L
Tjäderhane
Lauri
L
Eklund
Ritva
R
Heljasvaara
Taina
T
Pihlajaniemi
Riitta
R
Herva
Yanli
Y
Ding
John D
JD
Bartlett
Tuula
T
Salo
D000818:Animals; D002118:Calcium / Q000032:analysis; D043170:Collagen Type XVIII / Q000235:genetics / Q000378:metabolism*; D003743:Dental Enamel / Q000737:chemistry; D003804:Dentin / Q000737:chemistry; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007568:Jaw / Q000378:metabolism; D053519:Matrix Metalloproteinase 20; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D009808:Odontogenic Tumors / Q000235:genetics / Q000378:metabolism*; D010758:Phosphorus / Q000032:analysis; D012333:RNA, Messenger / Q000378:metabolism; D014070:Tooth / Q000254:growth & development* / Q000378:metabolism* / Q000648:ultrastructure
D043170:Collagen Type XVIII; D012333:RNA, Messenger; D010758:Phosphorus; C507111:MMP20 protein, human; D053519:Matrix Metalloproteinase 20; D020782:Matrix Metalloproteinases; C507113:Mmp20 protein, mouse; D002118:Calcium