Adhesion of Activated Platelets to Venous Endothelial Cells Is Mediated via GPIIb/IIIa

J Surg Res. 1996 Mar;61(2):543-8. doi: 10.1006/jsre.1996.0161.

Abstract

Normal circulating platelets do not adhere to intact, undisturbed endothelium. Studies have shown, however, that platelets will adhere to virally infected or thrombin-stimulated human umbilical vein endothelial cells. Using a novel platelet/endothelial cell adhesion assay we studied the interaction of thrombin-activated platelets to human saphenous vein endothelial cells (HSVEC), and its mechanism(s). Biotinylated platelets were exposed to Hepes-Tyrode buffer, 10E5 or PAC-1 [monoclonal antibodies (Mabs) blocking GPIIb-IIIa], AK4 (Mab blocking P-selectin, 6D1 (Mab blocking vWf binding to GPIb), RGDS (small peptide blocking the fibrinogen binding site), or EDTA (dissociates GPIIb-IIIa complex) and then activated with thrombin. The platelets were subsequently exposed to thrombin-stimulated monolayer HSVEC. Phycoerythrin-streptavidin was added to the wells to fluorescently label the platelets, followed by formaldehyde fixation and washing to remove nonadherent platelets. Adhesion of platelets to HSVEC was assessed using a fluorescent multiwell plate reader. Antibodies which blocked the GPIIb-IIIa receptor and agents which competitively bound the receptor all significantly inhibited activated platelet adhesion to the activated HSVEC. We have found that thrombin significantly increases platelet/HSVEC adhesion, and this event is mediated via the integrin GPIIb-IIIa (fibrinogen receptor). These GPIIb-IIIa receptor blocking Mabs and RGDS may be useful adjuncts for improving patency following angiographic intervention and/or vein grafting in patients with high risk of thrombosis. The assay we have developed is a valuable and relatively simple method for assessing platelet/endothelial cell adhesion and activation.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cells, Cultured
  • Edetic Acid / pharmacology
  • Endothelium, Vascular / cytology*
  • Humans
  • Mice
  • Molecular Sequence Data
  • Oligopeptides / pharmacology
  • Platelet Activation
  • Platelet Adhesiveness*
  • Platelet Glycoprotein GPIIb-IIIa Complex / physiology*
  • Saphenous Vein

Substances

  • Oligopeptides
  • Platelet Glycoprotein GPIIb-IIIa Complex
  • Edetic Acid
  • arginyl-glycyl-aspartyl-serine