ABSTRACT
G enes for 18 a and 8 ß integrin subunits have been identified in vertebrates, their protein products associating into 24 different heterodimeric membrane receptors. Skeletal cells-osteoclasts, osteoblasts and chondrocytes-exhibit characteristic integrin profiles and for some there is good evidence for a functional role. This is best exemplified by the osteoclast, the ‘bone’ resorbing cell o f the skeleton which expresses high levels of an RGD peptide-sensitive integrin, the (Xvß3 vitronectin receptor, that is intimately involved in recognition and adhesion to mineralised matrix and its degradation; this property has been utilised in the development o f novel drugs that inhibit 0Cvß3 function for use in osteoporosis and arthritis. This article will review the expression profiles o f integrins in the major cell types o f bone and cartilage, evidence for in tegrin function therein, and their role in skeletal developm ent where known.
