Chondrocyte-matrix interactions. Attachment to proteins isolated from cartilage.

Interactions between bovine chondrocytes and cartilage extracellular matrix proteins and proteoglycans were demonstrated by cell attachment to plastic surfaces coated with the macromolecules. Chondrocytes, which had been maintained in suspension culture, attached to fibronectin, bone sialoprotein, collagen II, and two novel 36- and 58-kDa proteins isolated from cartilage. Attachment to fibronectin and bone sialoprotein was inhibited by competition with an Arg-Gly-Asp containing peptide, whereas attachment to the 36- and the 58-kDa proteins was not affected. The chondrocytes attached but did not spread on 36- and 58-kDa proteins. Other matrix proteins tested gave little or no binding of the chondrocytes. These include a 59-kDa protein, a 100-kDa subunit protein, and a 148-kDa protein. Freshly isolated chondrocytes also attached to proteoglycans, while attachment to the other matrix constituents was the same as for cells maintained in spinner culture prior to assay.