Figure 5.

Reduced neointima formation in miR-143/145 mutant mice following carotid artery ligation. (A) Mice of the indicated genotypes were subjected to carotid artery ligation for 28 d, after which histological sections were obtained from the ligated artery and the unligated artery as a control 1900 μm proximal to the ligature and stained with H&E (left side) or for elastin (right side). The intimal (i) and medial (m) layers are designated with arrows in the ligated wild-type (WT) artery stained for elastin. Bar, 100 μm. (B) The intimal thickness in mice of each genotype 28 d after carotid artery ligation was determined by measuring the distance between the inner elastin layer and the lumen in at least five mice of each genotype. Medial thickness was measured as the distance between the inner and outer elastin layers. (C) Electron microscopy of carotid arteries of wild-type and dKO mice 14 d after ligation. SMCs from the wild-type artery adopt a migratory phenotype in response to ligation, giving rise to a neointima. In contrast, SMCs from the dKO artery retain a more organized arrangement and fail to form a neointima. The boundaries of representative SMCs are outlined in green. The dashed line in the bottom left panel indicates the internal boundary of the neointima.