Cartilage-related proteins

Cartilage-related proteins are a heterogeneous group of molecules that form the extracellular matrix (ECM) of cartilage, providing the tissue with its unique mechanical properties. The primary structural components include Type II collagen, which provides tensile strength, and aggrecan, a large proteoglycan that enables the tissue to withstand compressive forces (UniProt: P02458, P16112). Other significant proteins in this category include cartilage oligomeric matrix protein (COMP) and various small leucine-rich proteoglycans (SLRPs) that regulate collagen fibrillogenesis and cell-matrix interactions (PubMed: PMID 25103533). In degenerative joint diseases such as osteoarthritis, the homeostatic balance of these proteins is shifted toward catabolism, primarily mediated by matrix metalloproteinases (MMPs) and aggrecanases (ADAMTS-4 and -5) (PubMed: PMID 16147935). Therapeutic interventions targeting these proteins range from viscosupplementation with hyaluronic acid to the development of disease-modifying osteoarthritis drugs (DMOADs) like sprifermin, which aims to stimulate the synthesis of the cartilage matrix (ClinicalTrials.gov: NCT01919164).

Other names

Cartilage matrix proteinsChondrocyte-secreted proteinsCartilage extracellular matrix proteins

Mechanisms include the direct supplementation of matrix components (viscosupplementation), the inhibition of degradative enzymes (MMPs/ADAMTS) to prevent protein breakdown, and the activation of anabolic pathways in chondrocytes to increase protein synthesis (PubMed: PMID 28351403).