FIGURE 4.
PI3K inhibition delays the translocation of integrin αIIbβ3 to the platelet cytoskeleton. A and B, washed platelets were pretreated with either vehicle (DMSO) or LY294002 (LY; 25 μm), prior to stimulating with 1 unit/ml thrombin in the presence of purified fibrinogen (0.5 mg/ml). Platelets were lysed at the indicated times, and the cytoskeletal fraction was isolated and analyzed for integrin αIIbβ3 translocation, as described under “Experimental Procedures.” The anti-αIIb immunoblot (top) and corresponding actin loading control (bottom) in A are representative of three independent experiments, quantified in B by performing densitometry on anti-αIIb (SZ22) immunoblots, followed by correction for total protein loading based on actin levels. These results represent the mean ± S.E., n = 3 (**, p < 0.005; not significant (ns), p > 0.05).