Effect of soluble TGFBIp on platelet. A platelet suspension (100 μL containing 5 × 107 platelets) was added to a noncoated chamber slide with soluble-phase TGFBIp (1 μg/mL or 5 μg/mL) or fibrinogen (5 μg/mL). Platelets were allowed to adhere (15 minutes at 37°C), and wells were washed with Tyrode buffer. (A) Fixed platelets were stained for F-actin with FITC-conjugated phalloidin and were observed under a fluorescence microscope. The white bar represents 10 μm. Representative of platelet adhesion (B) and platelet spreading (pixels/cells) (C) in the presence of soluble-phase TGFBIp (0.5, 1, 2, and 5 μg/mL) or fibrinogen (Fg; 5 μg/mL). Platelet adhesion was detected by the acid phosphatase assay, spreading was detected using the MetaMorph program. (D) Time course adhesion of human washed platelets by soluble and immobilized TGFBIp. Platelet suspensions containing the indicated protein were dispensed in triplicate wells of microplates. After unbounded platelets were removed, adherent platelets were detected by the acid phosphatase assay as described in “Platelet adhesion assay.” All results are shown as the means ± SD of 3 different experiments and ANOVA. *P < .05 compared with BSA.
