PROTEOGLYCANS AS THERAPEUTIC AGENTS (I)

Proteoglycans are macromolecules which consist of a protein backbone ( the core protein) to which polysaccharidic chains called glycosaminogl ycans are covalently linked. Proteoglycans are mainly found in the ext racellular matrix, but also occur intracellularly and on cell surface membranes. The structure diversity of proteoglycans permits the consti tution of proteic and/or saccharidic sites capable of interacting with other matricial components, cellular molecules and soluble mediators. This great ability to interact with other molecules allows proteoglyc ans to play a key role in matrix assembly. The strongly anionic nature of glycosaminoglycans provides hydration and swelling pressure to som e tissues enabling them ro withstand compressional forces (cartilage), to filtrate (renal glomerulus), or to he transparent (cornea), Proteo glycans also regulate a Inr of cellular activities (adhesion, motility : proliferation, differentiation) and show some affinity for cytokines , controlling their availability, activity and stability by << crinope xy >>. Proteoglycans could also be exploited as therapeutic agents. Th is is the case of heparin, which has been used for, a long rime,Is an anticoagulant molecule. Moreover, the ability of proteoglycans to cont rol cytokines by crinopexy suggests that they could function as reserv oirs of soluble mediators, thus neutralizing toxic effects: or potenti ating desired activities in the treatment of different diseases.