αvβ3 Integrin Expression in Human Odontoblasts and Co-localization with Osteoadherin

Integrins are heterodimeric transmembrane receptors which promote cell adhesion, thus contributing to the maintenance of tissue organization in both normal and pathological conditions. To characterize the way odontoblasts may interact with other cells and the extracellular matrix in human teeth, we studied expression of αvβ3 integrin, a putative receptor for osteoadherin. We showed that αvβ3 integrin expression was restricted to odontoblasts, blood vessels, and small rounded cells in sound and carious pulp. Odontoblast staining intensity increased from the apical to the cusp region. Osteoadherin staining was strong in the whole odontoblast layer (with a slight decrease in the cusp region) and in predentin. Odontoblasts differentiating in vitro were stained with the anti-αvβ3 integrin antibody, first at the level of intercellular contacts, then throughout the cell membrane. These results suggest that the αvβ3 integrin could play a role in interodontoblast adhesion and odontoblast binding to the surrounding predentin/dentin/pulp matrix, possibly through osteoadherin.