A, Representative Western blots of SIRT1, membrane type 1-matrix metalloproteinase (MT1-MMP), monocyte chemoattractant protein-1 (MCP-1/CCL2), and MMP2 in human AAA samples and adjacent control aortas. B, Densitometric analysis of the protein levels of SIRT1, MT1-MMP, MCP-1/CCL2, and MMP2 in human AAA samples and adjacent control aortas (n=6). C, Quantitative analysis of SIRT1 activity in homogenates of human AAA samples and adjacent nonaneurysmal aortic sections (n=6). D, Fluorescence intensity indicating SIRT1 activity in homogenates of young mouse compared with that of the aged mouse (n=6). E, Representative Western blots of SIRT1 and p21 in abdominal aortas (AA) from aged and young mice. Adventitial tissue was removed from the aorta as much as possible, and each sample was pooled from 3 abdominal aortas together for immunoblot analysis. F, Representative immunofluorescent staining of SIRT1, α-smooth muscle actin (SMA), and 4′,6-diamidino-2-phenylindole (DAPI) in suprarenal aortas of young and aged mice (scale bars, 50 μm). G, Densitometric analysis of the protein level of SIRT1, which is normalized to α-SMA, in suprarenal aortas of young and aged mice (n=9). Three different visual fields were captured in each slide.