Chondrocyte-matrix attachment complexes mediate survival and differentiation.

Integrin mediated cell-extracellular matrix interactions are required for survival and differentiation of many cell types. In this review, the cell-matrix attachment complex (CMAX) is described for chondrocytes. The evidence that integrin-mediated signal transduction is necessary for normal chondrocyte differentiation and survival in various culture conditions and in vivo are reviewed. The possible signal transduction pathways stimulated by the extracellular matrix components are discussed with a review of current data from chondrocyte experiments. In addition, the influence of parathyroid hormone and transforming growth factor beta on chondrocyte survival has been included as they may function in concert with integrin mediated signal transduction. Finally, specific changes in gene expression preceding apoptosis are discussed. The current understanding of how integrin-mediated signals prevent apoptosis and implications of anchorage-dependent survival for development and differentiation of the chondrocyte phenotype are discussed.