Fig. 4

Blockage of integrin outside-in signaling attenuates Dab2-Ser24 phosphorylation stimulated by platelet agonists. a, b Human washed platelets were pre-incubated with the indicated concentrations of RGDS peptide at RT for 30 min and then stimulated with the indicated concentrations of the agonists. Platelet aggregation was recorded by a platelet aggregometer (Chrono-Log). After 10 min, human washed platelets were lysed and the platelet lysates were collected for Western blotting using the indicated antibodies. The proteolytic cleavage products of Dab2 were marked as *. Representative data of 2 independent experiments are shown. c, d Human washed platelets were pre-incubated with the indicated concentrations of LY333531 (LY) for 5 min and then stimulated with thrombin (Th, 0.1 U/ml). Platelet aggregation was recorded by a platelet aggregometer (Chrono-Log). After 10 min, human washed platelets were lysed and the platelet lysates were collected for Western blotting using the indicated antibodies. The proteolytic cleavage products of Dab2 were marked as *. e The level of Dab2-Ser24 phosphorylation and Dab2-Ser723 phosphorylation was quantified by ImageJ software and normalized by the expression of β-actin. The level of Dab2 phosphorylation in the resting platelet lysate was arbitrarily set as 1. The data are presented as the mean ± SEM of 5 independent experiments. **p < 0.01; ***p < 0.001