Figure 6.

Pyridoxamine treatment inhibits the activation state of platelets and neutrophils isolated from sickle cell disease (SCD) mice and patients. Platelets isolated from SCD mice (A-G) and patients (H-J) were pretreated with 1 mM pyridoxamine, followed by stimulation with 0.05 U/mL thrombin or 3.5 µg/mL collagen related peptide. (A and C) Representative traces of platelet aggregation and quantitative graphs. (B and D) Adenosine triphosphate secretion was monitored with a luciferin/luciferase reagent and are shown as % of control at the end of the time point. (E-J) Flow cytometry was performed to assess P-selectin exposure, αIIbβ3 activation and reactive oxygen species (ROS) generation. Neutrophils isolated from SCD mice (K-M) and patients (N-P) were pretreated with 1 mM pyridoxamine, followed by incubation with fMLP. Flow cytometry was carried out to determine the surface amounts of αMβ2 and L-selectin and ROS production. Data represent the mean±standard deviation (n=3-5). ^*P<0.05 and ^**P<0.01 versus vehicle control, Student’s t-test.