Figure 4.

GPVI KO platelets have reduced PS exposure and reduced thrombus stability. (A) WT or GPVI-deficient platelets were allowed to spread on fibrinogen or fibrin-coated coverslips, followed by incubation with FITC-Annexin V. Actin was counterstained with Alexa-568 phalloidin to count total number of adherent platelets (data not shown). Scale bar, 20 μm. The results are shown as mean ± SEM of 3 experiments. (B) Representative fluorescent images before and after injury. Asterisk indicates vessel occlusion. Embolization rate was determined by counting embolized thrombus fragments (size > 10 µm) after an initial thrombus had formed (thrombus size ≥ 10 µm). Observation period: 40 minutes or until vessel occlusion. The results are shown as mean ± standard deviation of ≥6 mice. ***P < .001.