Role of glycosaminoglycans in inflammation

Abstract

Glycosaminoglycans (GAGs) are large, polyanionic molecules expressed throughout the body, either in association with cell surfaces and extracellular matrices, or stored within intracellular compartments. The GAG heparin is synthesised by and stored exclusively in mast cells, which are strongly associated with allergy and inflammation and is co-released with histamine upon cellular degranulation. The closely related GAG heparan sulphate is expressed, as part of a proteoglycan, on cell surfaces. Most notably, heparan sulphate is associated with the surfaces of vascular endothelial cells, known to be pivotally involved in the control of inflammatory cell adhesion and extravasation. The physiological role of these molecules is not well understood but evidence suggests that they may be involved in limitation of the inflammatory response and, in particular, regulation of cell adhesion and trafficking.