(A and B) Western blotting (A) and q-PCR (B) analysis of ITGA6 in aorta samples from aortic aneurysm patients and normal aorta samples from donors (n = 6 per group). Six-week-old male Apoe^–/–/Tagln-cre mice were injected with lentivirus vector encoding negative shRNA control (Lenti-shNC) or lentivirus vector encoding shRNA targeting Itga6 (Lenti-shItga6) with reverse loxP sites, which can be recognized by Cre recombinase. After injection for 14 days, mice were infused with saline or Ang II (1,000 ng/kg/min) for 28 days. (C) Representative photograph of aortas from saline or Ang II–infused Apoe^–/–/Tagln-cre mice infected with Lenti-shNC or Lenti-shItga6. Scale bar: 2 mm. (D) Incidence of Ang II–induced aortic aneurysm. (E) Maximal abdominal lumen diameter in mice infused with saline (n = 6) or Ang II (n = 8–10), as measured by ultrasound. (F) Histopathological images of suprarenal abdominal aortas of saline- or Ang II–infused Apoe^–/–/Tagln-cre mice infected with Lenti-shNC or Lenti-shItga6. Scale bars: 50 μm and 400 μm (insets). EVG, elastic van Gieson staining. (G) Representative in situ zymography photomicrographs showing MMP activity of suprarenal abdominal aortas. Scale bars: 20 μm. L, lumen. (H) Representative immunofluorescence staining of α-SMA expression in suprarenal abdominal aortas. Scale bars: 20 μm. L, lumen. (I) Western blotting analysis of the VSMC contractile markers (α-SMA and SM22) and synthetic marker (Vimentin) in suprarenal abdominal aortas from saline- or Ang II–infused Apoe^–/–/Tagln-cre mice infected with Lenti-shNC or Lenti-shItga6 (n = 6 per group). Statistical analysis was performed by Student’s t test (A and B), Fisher’s exact test (D), or 1-way ANOVA (E and I). For all statistical plots, the data are presented as mean ± SEM.