Dentin Matrix Protein 1 Immobilized on Type I Collagen Fibrils Facilitates Apatite Depositionin Vitro

Dentinogenesis imperfecta determines structural alterations of the collagen structure still not completely elucidated. Immunohistochemical analysis was used to assay Type I and VI collagen, various non-collagenous proteins distribution in human primary teeth from healthy patients or from patients affected by type I dentinogenesis imperfecta (DGI-I) associated with osteogenesis imperfecta (OI). In sound primary teeth, an organized well-known ordered pattern of the type I collagen fibrils was found, whereas atypical and disorganized fibrillar structures were observed in dentin of DGI-I affected patients. Expression of type I collagen was observed in both normal and affected primary teeth, although normal dentin stained more uniformly than DGI-I affected dentin. Reactivity of type VI collagen was significantly lower in normal teeth than in dentin from DGI-I affected patients (P<0.05). Expressions of dentin matrix protein (DMP)-1 and osteopontin (OPN) were observed in both normal dentin and dentin from DGI-I affected patients, without significant differences, being DMP1 generally more abundantly expressed. Immunolabeling for chondroitin sulfate (CS) and biglycan (BGN) was weaker in dentin from DGI-I-affected patients compared to normal dentin, this decrease being significant only for CS. This study shows ultrastructural alterations in dentin obtained from patients affected by DGI-I, supported by immunocytochemical assays of different collagenous and non-collagenous proteins.

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Hyper-expression of Osteocalcin mRNA in Odontoblasts of Hyp Mice

Journal of Dental Research ◽

10.1177/154405910508400115 ◽

2005 ◽

Vol 84 (1) ◽

pp. 84-88 ◽

Cited By ~ 12

Author(s):

T. Onishi ◽

T. Ogawa ◽

T. Hayashibara ◽

T. Hoshino ◽

R. Okawa ◽

...

Keyword(s):

Matrix Protein ◽

Type I Collagen ◽

Tooth Germ ◽

Type I ◽

Wild Type ◽

Gene Expressions ◽

Dentin Matrix Protein ◽

Osteocalcin Gene ◽

Dentin Matrix

The Hyp mouse is a murine homologue of human X-linked hypophosphatemia that displays hypo-mineralization in bone and dentin. In this study, we tested the hypothesis that the defect in Hyp mice leads to alterations in the expression of dentin matrix proteins that may be associated with the hypo-mineralization changes in the tissues. Quantitative RT-PCR analyses showed that expression of the osteocalcin gene in Hyp mice tooth germ samples was significantly higher than in wild-type mice, whereas the gene expressions of osteonectin, osteopontn, dentin matrix protein 1, and type I collagen in both types of mice were similar. Further, cultured Hyp mice tooth germ samples exhibited a higher expression of the osteocalcin gene than did those from wild-type mice, which was in accord with the results of our in vivo analysis. These findings suggest that osteocalcin mRNA is highly expressed in Hyp mice odontoblasts and may be associated with dentin hypo-mineralization.

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Dentin matrix protein 1 (DMP1) expression in developing human teeth

Brazilian Dental Journal ◽

10.1590/s0103-64402009000500002 ◽

2009 ◽

Vol 20 (5) ◽

pp. 365-369 ◽

Cited By ~ 12

Author(s):

Elizabeth Ferreira Martinez ◽

Luciana Alves Herdy da Silva ◽

Cristiane Furuse ◽

Ney Soares de Araújo ◽

Vera Cavalcanti de Araújo

Keyword(s):

Dental Pulp ◽

Matrix Protein ◽

Enamel Organ ◽

Dentin Matrix Protein 1 ◽

Tooth Formation ◽

Dentinal Tubules ◽

Dental Lamina ◽

Dentin Matrix Protein ◽

Dental Papilla ◽

Dentin Matrix

Dentin matrix protein 1 (DMP1) is an acidic phosphoprotein that plays an important role in mineralized tissue formation by initiation of nucleation and modulation of mineral phase morphology. The purpose of the present study was to examine the immunoexpression of DMP1 in tooth germs of 7 human fetuses at different gestational ages (14, 16, 19, 20, 21, 23 and 24 weeks) comparing with completed tooth formation erupted teeth. The results showed the presence of DMP1 in the dental lamina, as well as in the cells of the external epithelium, stellate reticulum and stratum intermedium of the enamel organ. However, in the internal dental epithelium, cervical loop region and dental papilla some cells have not labeled for DMP1. In the crown stage, DMP1 was expressed in the ameloblast and odontoblast layer, as well as in the dentinal tubules of coronal dentin near the odontoblast area. Erupted teeth with complete tooth formation exhibited immunolabeling for DMP1 only in the dentinal tubules mainly close to the dental pulp. No staining was observed in the enamel, predentin or dental pulp matrix. DMP1 is present in all developing dental structures (dental lamina, enamel organ, dental papilla) presenting few immunoexpression variations, with no staining in mineralized enamel and dentin.

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