Recent advances in connective tissue research

This comprehensive review explores various aspects of cartilage and its degradation processes. It begins with an examination of changes in cartilage proteoglycan structure during aging, discussing their origins and effects. The mechanisms underlying cartilage catabolism are analyzed, alongside the potential role of synovial factors in cartilage destruction. The review highlights how mononuclear cell factors influence the release of proteoglycan latent proteinase in human articular cartilage during organ culture. Additionally, it investigates the responses of human synovial fibroblasts to mononuclear cell factors and retinoic acid, as well as the impact of certain polysulphated polysaccharides on hyaluronate synthesis. The degradation of the cartilage matrix by purified elastase is addressed, including the role of an endogenous specific cartilage elastase inhibitor. The review further discusses the variations in serine and cysteine proteinase inhibitors in human articular cartilage with aging and degeneration. It also covers the interactions between neutrophil enzymes, antiproteases, and oxygen radicals in cartilage proteoglycan degradation, and the amplification of oxyradicals through eicosanoid synthesis. Moreover, it presents an assay for proteoglycanase applicable to cultured articular chondrocytes, the specificity of murine monoclonal antibodies to rabbit cartilage proteoglycan, and the identification of glycoprotein