ENDOTHELIAL GLYCOCALYX STRUCTURE AND ROLE IN MECHANOTRANSDUCTION

The endothelial cell (EC) surface is coated with a glycocalyx (GCX) layer that is composed of a wide variety of membrane-bound macromolecules: sulfated proteoglycans, hyaluronic acid, sialic acids, glycoproteins, and plasma proteins. The GCX surface layer has been estimated to be from 20 nm to several microns thick in a static fluid environment, depending on cell/tissue preservation and microscopic visualization techniques that are reviewed in detail. Recently, there has been growing recognition that the GCX is a mechanotransducer and plays an important role in transmitting force to the cell's actin cytoskeleton and in initiating intracellular signaling. GCX thinning and shedding have been demonstrated to occur in diseases associated with mechanotransduction dysfunction. Recognizing the association of GCX degradation with disease, this chapter will provide an overview and synthesis of current knowledge concerning GCX molecular and physical structure and its function in endothelial mechanotransduction.