Fig. 4.

SDF-1α-mediated enhancement of platelet activation by CXCR4. A, Washed platelets (2 × 10⁸/mL^− 1) were co-stimulated with a threshold concentration of collagen (0.5 μg/mL^− 1) and increasing concentrations of SDF-1α, and monitored for platelet aggregation. A representative trace (Ai) and quantified area under the curve analysis (Aii) are shown. Data are mean ± SEM, n = 10, **P < 0.01, ***P < 0.001 vs vehicle, One-way ANOVA with Dunnett's multiple comparison test. B–D). Similarly, washed platelets (2 × 10⁸/mL^− 1) were pre-treated with vehicle control or inhibitors; 100 nM AMD3100 (CXCR4) and 10 μg/mL^− 1 11G8 (CXCR7) or IgG₁ control in the presence of 10 μg/mL^− 1 IV.3 and co-stimulated with 0.5 μg/mL^− 1 collagen and 100 ng/mL^− 1 SDF-1α. Platelet aggregation with area under the curve analysis (B) and peak ATP secretion (C) were assessed by lumi-aggregometry, with the releasates from aggregated samples analysed for TxB₂ (D). Data are mean ± SEM, n = 4 (n = 6 for B), *P < 0.05, **P < 0.01, ***P < 0.001, One-way ANOVA with Dunnett's multiple comparison test.