Chondroitin sulfate and joint disease.

Chondroitin sulfate is an important and major component of articular cartilage, where it occurs as part of the large proteoglycan, aggrecan. In the early stages of joint disease, both in animal models and in man, there are changes in chondroitin sulfate that affect the chain length and the pattern of sulfation. These changes can be detected by monoclonal antibodies and appear to reflect part of the cellular response by the chondrocytes to damage to the articular cartilage matrix. The specificity of the changes show that the biosynthesis of chondroitin sulfate is under tight cellular control in chondrocytes and suggests that selected patterns of sulphation within chains are expressed to suit different biological functions.