Metabolism of Cartilage Proteoglycans in Health and Disease

Abstract

Cartilage proteoglycans are extracellular macromolecules with complex structure, composed of a core protein onto which a variable number of glycosaminoglycan chains are attached. Their biosynthesis at the glycosaminoglycan level involves a great number of sugar transferases well-orchestrated in Golgi apparatus. Similarly, their degradation, either extracellular or intracellular in lysosomes, involves a large number of hydrolases. A deficiency or malfunction of any of the enzymes participating in cartilage proteoglycan metabolism may lead to severe disease state. This review summarizes the findings regarding this topic.

Protective effects of aucubin on osteoarthritic chondrocyte model induced by hydrogen peroxide and mechanical stimulus

“…In the degenerated cartilage, a decrease in the content of chondroitin sulfate results in a decrease of water content that affects the capability of cartilage to absorb the external stress [ 39 ]. In this study, H 2 O 2 and compression stimulation significantly reduced the sGAG production activity and decreased sGAG content.…”

Micro- and nano-mechanics of osteoarthritic cartilage: The effects of tonicity and disease severity

“…3.b,c). One explanation might be that there are two transport time-scales that are involved, one is the movement of the water into the tissue, and the other one is the diffusion of the macromolecular osmolytes such as PGs degradation products or intact molecules freed from the swollen collagen matrix out of the tissue (Houard et al, 2013;Vynios, 2014). Transient response to osmotic loading has been also reported in computational studies of swelling and volumetric changes of multi-phasic materials under osmotic loading (Albro et al, 2007).…”

A detailed quantitative outcome measure of glycosaminoglycans in human articular cartilage for cell therapy and tissue engineering strategies

“…Proteoglycans and glycosaminoglycans (GAGs) are critical to the function of articular cartilage 7,8 . With the exception of hyaluronan (HA), GAGs are synthesised covalently bound to core proteins to form proteoglycans such as aggrecan 8,9 . The highly anionic GAGs endow cartilage with its resistance to compressive loading by binding and organising water molecules 4 .…”