Immunohistochemical staining for α-actin shows positive SMCs in atherosclerotic lesions.

(A) wt-wt; (B) ko-wt; (C) ko-ko animals; bar = 0.2 mm; (D) α-actin–positive SMCs within lesions were counted on 5 aortic sinus sections 80 μm apart. Dots represent the mean number of SMCs per section for each animal. Black dots (●) correspond to animals that lack endothelial P-selectin (ie, wt-ko, ko-ko). Bars show the mean ± SEM for each group. The atherosclerotic lesions of the chimeric animals appear to have an intermediate content of SMCs.