The Adaptive Remodeling of Endothelial Glycocalyx in Response to Fluid Shear Stress
Figure 12
Adaptive remodeling of glycocalyx with membrane rafts and actin cytoskeleton.
Under static conditions, glypican-1carrying only HS is localized on the dispersed lipid rafts and caveolae on the membrane. The actin cytoskeleton interacts with the transmembrane protein syndecan-1 and the caveolar structural protein caveolin-1 for stabilization. After 30 min of shear exposure, lipid rafts have carried glypican-1 with anchored HS to the cell boundary (clustering), while syndecan-1 carrying HS and CS, and caveolae with localized glypican-1 and anchored HS, do not move. Actin microfilaments increase in both apical and basal aspects of the cell. After 24 h of exposure, new caveolae are assembled on the apical surface, which may associate with newly synthesized glypican-1. Syndecan-1 (HS/CS), and glypican-1(HS) that is bound to anchored caveolae, and mobile lipid rafts are synthesized and result in nearly uniform distributions of HS and CS. Numerous long stress fibers form and most distribute in the apical part of the cell, where they stabilize new caveolae and syndecan-1. In the basal part of the cell, actin microfilaments increase, scatter and arrange in a disorderly fashion. Our findings portray a dynamic reorganization of the EC glycocalyx.