The platelet surface glycosylation caused by glycosidase has a strong impact on platelet function

Abstract

 

Platelet surface glycosylation defects has been reported to be significantly associated with many diseases. Our previous study found that platelet surface glycosylation is altered in coronary heart disease. In this study, we further investigated whether altered glycosylation affects platelet function. Platelets were obtained from ten healthy volunteers. The platelet surface terminal sialic acid was removed by neuraminidase A, and N-linked oligosaccharides was removed by PNGase F. The function of the enzyme-treated platelet was measured. The activation and platelet adhesion to von Willebrand factor (vWF) was measured by flow cytometry. Platelet aggregation induced by ADP, arachidonic acid and collagen was detected through light transmission aggregometry, and platelet-leukocyte aggregates (PLAs) was detected by flow cytometry. Neuraminidase A treatment caused sialic acid level decrease and β-galactose level increase significantly on platelet surface. Activation marker CD62P did not change. Platelet adhesion to vWF was increased significantly (P < 0.05). ADP-induced platelet aggregation was significantly reduced (P < 0.05). Platelet-granulocytes aggregates and platelet-monocytes aggregates increased (P < 0.05). Platelet surface sialic acid was increased after PNGase F treatment. Platelet aggregation by all agonists were significantly reduced (P < 0.05). There is no difference in the binding of vWF and PLAs for PNGase F treated platelet. We demonstrated that asialoglycosylation enhances platelet binding to vWF and forming PLAs, suggest that it may be associated with high platelet reactivity and the increased risk of thrombosis.