Figure 5.

α₁AT expression in response to cigarette smoke: evidence for MMP-12-mediated α₁AT degradation. Serum and saline perfused (through right ventricle) lung tissue extracts were obtained following 6 months of cigarette smoke exposure (Sm). Age-matched sham or non-smoke-exposed (NS) mice were used as controls. Again, each lane represents equally pooled samples from three lungs. Equal amounts of protein were then subjected to Western analysis using an antibody specific for α₁AT. Top: Blood serum α₁AT levels were at least as prominent in cigarette smoke-exposed (Sm) lungs compared to non-smoke-exposed (NS) in both wild-type and MMP-12^−/− mice. Bottom: Lung α₁AT levels are decreased (by 50%) in response to cigarette smoke in wild-type as compared to MMP12^−/− mice.