Extracellular matrix formation by chondrocytes in monolayer culture (original) (raw)

1981, Journal of Cell Biology

The matrix of hyaline cartilage is composed mainly of chondroitin sulfate proteoglycan (CSPG) (9, 11), type II collagen (18 ; for review see reference 17), and minor portions of other collagens (3). The synthesis and secretion of these macromolecules by cartilage cells has been the subject of numerous studies (7, 10, 14, 21, 31). Several laboratories have made use of the ability of matrix-free chondrocytes to reconstitute cartilage matrix in vitro (1, 5, 20, 25, 28, 29). Oakes et al. (20) have shown that cartilage matrix accumulated by chondrocytes grown in culture at high densities is ultrastructurally reminiscent of cartilage from embryonic tissues. In a previous study we described the development of a pericellular matrix on the surface of chondrocytes after release from embryonic chick cartilage with proteases (5). This "glycocalyx" contained type II collagen and fibronectin (13, 27, 34), a fibroblast surface glycoprotein normally not present in embryonic chick cartilage (5, 15), but present in the cartilage blastema (6). Transfer of suspended chondrocytes to monolayer culture resulted in cell spreading and loss of pericellular type II collagen, whereas