Matrix metalloproteinases and aggrecanases involved in cartilage matrix degradation

Enzymes involved in cartilage breakdown are a group of proteolytic enzymes that degrade the extracellular matrix (ECM) components of cartilage, such as type II collagen and aggrecan. The major families include matrix metalloproteinases (especially MMP-13, called collagenase-3), aggrecanases (notably ADAMTS-4 and ADAMTS-5), various cathepsins (particularly cathepsin K, B, D, and S), and serine proteases like HTRA1. Overactivity or upregulation of these enzymes is a hallmark of cartilage-destructive diseases such as osteoarthritis and rheumatoid arthritis. These enzymes break down structural proteins and proteoglycans, leading to loss of cartilage integrity, joint dysfunction, and pain. They are principal targets for drug development aimed at slowing or preventing joint degeneration[1][2][3][4]. Key points: - The most important proteins mediating cartilage breakdown are MMP-13 (type II collagenase/collagenase-3), ADAMTS-5 ("aggrecanase-2"), cathepsin K, and HTRA1[1][2][5]. - These groups represent families of enzymes; thus, "enzymes involved in cartilage breakdown" is not a canonical name, but a collective category. - Regulation and inhibition of these enzymes is a major therapeutic strategy for osteoarthritis and related conditions[3][4][5]. - If a specific therapeutic target is required, it is recommended to use "Matrix metalloproteinase 13," "ADAMTS-5," or "Cathepsin K" as canonical singular targets. Note: This "target" is not a single molecule but a functionally defined group. For structured data applications, it is best to specify a particular enzyme such as "Matrix metalloproteinase 13 (MMP-13)" or "ADAMTS-5" for maximal precision[1][2].

Other names

Cartilage-degrading enzymesCartilage matrix proteasesChondrolytic enzymes

Enzyme inhibitors that block proteolytic activity (e.g., competitive inhibition, chelation of active-site zinc); Antibody or small-molecule blockade of substrate binding; Gene silencing (siRNA for enzyme isoforms); Indirect inhibition via anti-inflammatory pathways