Matrix molecules play a role in mediating chondrocyte aggregation, attachment and spreading

grantor: University of TorontoThe extracellular matrix synthesized by chondrocytes occupies the majority of the cartilage volume. Among the most abundant macromolecules in cartilage are hyaluronan, type II collagen, aggrecan and link protein, all of which play a role in maintaining the unique three-dimensional structure of cartilage. This study was designed to investigate the roles of these matrix molecules in mediating chondrocyte-matrix interaction. Chondrocytes, harvested from sterna of chicken embryos, were treated with enzymatic (hyaluronidase and collagenase), chemical (ß-D-xyloside) or antisense techniques to suppress the function of matrix molecules. Degradation of hyaluronan and collagen or reduction in the expression of aggrecan and link protein enhanced cell attachment. Furthermore, hyaluronidase treatment also reduced the binding of aggrecan, link protein and type II collagen to cell surfaces, and induced chondrocyte aggregation, which was mediated by ß1-integrin and type II collagen. In short, the effects of hyaluronan on cell-matrix interaction were dominant over the other matrix molecules. These observations might be applied to develop a therapeutic technique in cartilage repair.M.Sc