Fibrin clot retraction mediated by the cells stably expressing mutant α_IIbβ₃.

293 cells (control), 293 cells stably expressing wild-type β₃ alone, wild-type α_IIbβ₃, Tyr143Hisα_IIbβ₃, or KO mutant α_IIbβ₃ suspended in Tyrode/HEPES buffer (2 × 10⁶ cells/mL) were incubated with 10 mM tranexamic acid, 250 μg/mL fibrinogen, and 2 mM CaCl₂ at 37°C in a siliconized glass tube in the presence of 50 μM cyclo(RGDfV) (α_vβ₃-specific antagonist). Then 1 U thrombin was added to 1 mL cell suspension. Clot retraction was monitored by digital photography every 30 minutes. Data were expressed as % clot retraction = [(area t₀ − areat)/area t₀] × 100. Results are representative of 3 separate experiments.