Figure 6.

Effect of macrophage Mmp12 deficiency on aortic composition and Ang II (angiotensin II)–induced abdominal aortic aneurysms (AAA) development and survival. A and B, Relative β-actin-normalized Mmp12 gene expression in bone marrow-derived macrophages from Mmp12^flox/flox/Apoe^-/- and Mmp12^flox/flox/Apoe^-/-/Csf1r-iCre (A), and Mmp12^flox/flox and Mmp12^flox/flox/Csf1r-iCre (B) mice at 5 to 6 weeks post-tamoxifen administration. n=4 to 5 per group; *P<0.05. C and D, Representative images of immunofluorescence staining and quantification of Neutrophils (Ly6G, red), NETs (Cit-H3, red), and complement component 3d (C3d, red) in suprarenal abdominal aorta of Mmp12^flox/flox/Apoe^-/- and Mmp12^flox/flox/Apoe^-/-/Csf1r-iCre (C) and Mmp12^flox/flox and Mmp12^flox/flox/Csf1r-iCre (D) mice at 5 to 6 weeks post-tamoxifen administration. Nuclei are stained blue with DAPI. n=4 per group. Scale bar: 500 µm. *P<0.05, 2-tailed Mann-Whitney U test (A through D). E, Kaplan-Meier survival curves of Ang II–infused Mmp12 ^flox/flox/Apoe^-/- (n=9) and Mmp12 ^flox/flox/Apoe^-/-/Csf1r-iCre (n=10) mice post-tamoxifen administration. The curves were compared using log-rank (Mantel-Cox) test. P<0.05. F, Quantification of maximal suprarenal abdominal aorta external diameter of the surviving mice. **P<0.01 by 2-tailed Mann-Whitney U test. Cit-H3 indicates citrullinated histone 3; DAPI, 4′,6-diamidino-2-phenylindole; MMP, matrix metalloprotease; NE, neutrophil elastase; and NET, neutrophil extracellular trap.