Nuevas perspectivasIntegrinas y enfermedad periodontal

Resumo

The cell-substratum attachment is an esential requirement for a number of cellular functions such as proliferation, differentiation, migration and tissue regeneration. Detachment of the epithelium from the tooth surface and an apical proliferation of the junctional epithelium are observed during the development of the periodontitis. The changes in the surface of epithelial cells lead to a modification of the basement membrane -and cementum-epithelial junction interactions. All of this requires the interaction of cell membrane receptors with distinct extracellular matrix proteins. Integrins are a family of cell adhesion receptors that mediate cell-extracellular matrix interactions as well as cell-cell adhesion. They are able to link the extracellular matrix and the cellular cytoskeleton, regulating the cellular behaviour. Among the different extracellular molecules, fibronectin, laminin, and various types of collagens are ligands for the integrins. It has been described the presence of several integrins in gingival tissues. Some of them are expresed in the vascular endothelium and in inflamatory cells in the gingival connective tissue. The a2ẞ1, a3ß1, a6ß1 integrins are all expressed in human gingival epithelium in an overall cell surface distribution in basal cells and in cells of the junctional epithelium. They are also related with cell to cell interactions. The a6ß4, integrin is mainly expressed in gingival tissues at the basal membrane of basal cells in gingival and junctional epithelium. This integrin is a component of hemidesmosomes. The knowledgement of these cell adhesion receptors as well as the mechanims of regulation of integrins could contribute to the development of new therapeutic drugs for the periodontal disease.