Figure 2.

CD36 deficiency blunts platelet responses to agonists in hypercholesterolemic plasma. (a,b) Platelet aggregation in platelet-rich plasma from mice of the indicated genotypes on the indicated diets was induced by ADP and optically monitored. Representative aggregation curves are shown. Bar graph shows aggregation results expressed as maximal amplitude of aggregation (mean ± s.e.m.; n = 3 for WT, n = 4 for Apoe^−/−, n = 6 for Apoe^−/− Cd36^−/−, n = 3 for Ldlr^−/− and n = 4 for Ldlr^−/− Cd36^−/−). (c) Platelets were isolated by gel filtration of pooled blood from wild-type and Cd36^−/− mice on a chow diet and Apoe^−/− mice on a Western diet as described in Methods. Citrated, pooled, platelet-poor plasma from either wild-type or Apoe^−/− mice on a Western diet was isolated and combined with platelets of the indicated genotype at a 1:1 ratio. Aggregation was induced by ADP and optically monitored. Representative aggregation curves are shown. (d) Bar graph shows aggregation results from c expressed as maximal amplitude of aggregation (mean ± s.e.m.; n = 3 for WT, n = 3 for Apoe^−/− and n = 4 for Cd36^−/−). (e) Flow cytometric analysis of integrin α_IIbβ₃ activation on mouse platelets. Platelets and citrated, platelet-poor plasma were isolated and combined at a 1:2 ratio (vol/vol), stimulated with ADP and integrin α_IIbβ₃ activation was assessed using JON/A, a monoclonal, phycoerythrin-conjugated antibody for mouse α_IIbβ₃ in the activated conformation (mean ± s.e.m.; n = 3 for WT, n = 3 for Apoe^−/−, n = 4 for Cd36^−/−). *P < 0.05, **P < 0.01 and ***P < 0.001. See Supplementary Methods for details.