Spatio-temporal expression of E-cadherin during human odontogenesis. An immunohistochemical study.

AIMS

In craniofacial development, both morphogenesis and cell differentiation are governed by inductive tissue reactions, which mostly take place between epithelial and mesenchymal tissue. Studies in molecular biology have shown that cell interactions with cell adhesion molecules contribute to cell migration and differentiation. The aim of this study was to investigate E-cadherin expression during normal craniofacial development in human fetuses.

METHODS

The study was performed on 7 human fetuses aged between the 9th and the 16th week. Histological sections were subjected to immunohistochemical treatment with anti E-cadherin monoclonal antibodies (diluted 1:100 in PBS).

RESULTS

Immunohistochemical methods evidenced E-cadherin expression in the cells of the developing tooth at all stages investigated. Expression was particularly evident in the dental lamina, at the junction between cells of the oral epithelium and those of the enamel organ, in cells of the stellate reticulum and in those of the dental follicle. Reactivity to E-cadherin was also observed in the oral, nasal and lingual epithelium and in the myoblast and osteoprogenitor cells. E-cadherin did not always stain to the same intensity, indicating greater expression in the epithelium and dental lamina.

CONCLUSIONS

E-cadherin plays a role in craniofacial development in man, and is present in different morphogenetic processes such as odontogenesis, ossification, mandibular skeletogenesis and myogenesis of the tongue muscles.