Inhibition of platelet adhesion to fibronectin, fibrinogen, and von
Willebrand factor substrates by complex gangliosides
SA Santoro
Department of Pathology and Medicine, Washington University School of
Medicine, St Louis, MO 63110.
Gangliosides, which are complex glycosphingolipids containing sialic acid,
are found in cell membranes and have been implicated in a variety of cell
surface events including cellular adhesion. Complex gangliosides were
observed to inhibit the adhesion of thrombin- activated platelets to
substrates of fibronectin, von Willebrand factor, and fibrinogen. This
adhesion, which is mediated by the glycoprotein IIb-IIIa complex, was
differentially inhibited by gangliosides depending on the number of sialic
acid residues present within the ganglioside. The observed order of
effectiveness was GT1b greater than GD1a greater than GM1 greater than
asialo-GM1. Another structurally related glycosphingolipid, globoside,
exhibited little inhibitory activity. In contrast to the inhibition of
platelet adhesion to von Willebrand factor mediated by the glycoprotein
IIb-IIIa complex, gangliosides had no detectable effect on the
ristocetin-dependent adhesion of platelets to von Willebrand factor
mediated by glycoprotein Ib. These results suggest that the function of the
glycoprotein IIb- IIIa complex may be modulated by gangliosides in a manner
similar to that previously described for the closely related vitronectin
receptor.
Volume 73,
Issue 2,
pp. 484-489,
02/01/1989
Copyright © 1989 by The American Society of Hematology
