Effect of Mmp12 deletion on Ang II–induced AAA development and progression in hyperlipidemic WT mice. A. Kaplan-Meier survival curves of Ang II–induced AAA in hyperlipidemic WT (n=17) and Mmp12-/- (n=20) mice. The curves were compared using log-rank (Mantel-Cox) test; P<0.05. B, Quantification of maximal suprarenal abdominal aorta external diameter at baseline (no Ang II) and in animals surviving 4 weeks of Ang II infusion; n=4 to 9. C and D, Representative immunofluorescence staining images and quantification of neutrophils (Ly6G, red), neutrophil extracellular traps (Cit-H3, red), and NE (red) in surviving hyperlipidemic WT and Mmp12-/- mice after 28 days of Ang II infusion (C) and saline-infused control animals (D). Nuclei are stained blue with DAPI. n=4 per group. Scale bar: 500 µm. *P<0.05, **P<0.01, by Kruskal-Wallis test with Dunn multiple comparisons post hoc test (B), or *P<0.05, by 2-tailed Mann-Whitney U test (C and D). Ang II indicates angiotensin II; Cit-H3, citrullinated histone 3; DAPI, 4′,6-diamidino-2-phenylindole; HFD, high-fat diet; MMP, matrix metalloprotease; NE, neutrophil elastase; SAA, suprarenal abdominal aorta; and WT, hyperlipidemic wild type.