All mice were infused with saline or Ang II for 4 wk. A, Representative photographs showing macroscopic features of aneurysms induced by Ang II. The arrow shows a typical AAA (scale bars, 5 mm). B and C, The incidence (B) and survival curve (C) of Ang Il–induced AAA in SIRT1-VSMC–specific transgenic (SV-Tg) Apoe−/− mice (n=29) compared with those in Apoe−/− mice (n=33). There was no AAA formation in saline-infused mice (n=10), and the number of mice that developed AAA included the deaths caused by abdominal aortic rupture. D, The maximal abdominal aortic diameter in saline- and Ang II–infused mice. E, Representative staining with elastin and elastin degradation score in suprarenal aortas from saline- and Ang II–infused mice. The magnified photographs were taken at the location where the most severe elastin degradation occurred (scale bars, 150 and 50 μm; magnified photographs). F, Aorta homogenates were obtained from Apoe−/− and SV-Tg Apoe−/− mice infused with saline or Ang II for 4 wk. Western blot and densitometric analysis of the protein levels of monocyte chemoattractant protein-1 (MCP-1/CCL2) and matrix metalloproteinase 2 (MMP2) in aorta homogenates (n=4–6).