Actin-associated proteins in ameloblast differentiation

Focal contacts are systems of adherens junctions of the cell-extracellular matrix type, which allow the transfer of fundamental signals from the extracellular matrix to nuclear compartments, capable of regulating adhesion, proliferation, migration and differentiation of cells. Recently, many authors have concentrated their attention on epitheliomesenchymal interactions which guide organogenesis of dental germ, identifying numerous growth and differentiation factors and having the inner enamel epithelial cells of the enamel organ as a target. Given that the two cellular compartments in their tooth germ are separated by a basal membrane and by an extracellular matrix, which touches it, we wanted to evaluate the presence of focal contacts through the identification of talin and vinculin, proteins of the actin-associated protein complex. In this study we utilized the hemimandibles of young Wistar rats and we extracted the related odontogenic tooth organs present at their apical end. Specimens are processed with antibody against vinculin and talin. Results show that these junctional system proteins are present at the apical poles of both cellular compartments suggesting that putative epithelial-mesenchymal interactions, other than marker molecules, may use focal contacts as a system for transmission of signals.