Endothelial and platelet P-selectin both affect the size of atherosclerotic lesions formed in apoE^−/− animals.

Lesions at the aortic sinus were stained with oil red-O and measured. Dots represent the mean lesion size per animal. The bar indicates the mean lesion area ± SEM of the corresponding group. (A) Animals that received bone marrow transplants. Wt-wt and ko-wt animals had significantly larger lesions than wt-ko and ko-ko animals, establishing that endothelial P-selectin is crucial in atherosclerosis. Wt-wt animals had larger lesions than ko-wt animals, showing that also platelet P-selectin is important in atherosclerotic lesion growth. (B) Mice that did not receive transplants. The lesions in apoE^−/−P-sel^+/+ (wt) and apoE^−/−P-sel^−/− (ko) mice were not significantly different from those of wt-wt and ko-ko mice, respectively (shown in panel A).