Effect of A1AT against executioner caspases in vivo. (A) Representative immunoblots of human MM-A1AT and ZZ-A1AT expression in the lungs of mice instilled with either control Lac-Z-AAV or MM-A1AT or ZZ-A1AT AAV (1 × 1010; 50 µL), followed, 4 wks later, by active caspase-6 intratracheal instillation (5 U; 50 µL; 48 h). The upper band represents A1AT immunoblots (human recombinant A1AT used as a control in the last lane), and the lower band represents vinculin immunoblots used as a loading control. (B) Endogenous lung caspase-3/7 activity and (C) lung morphometry measurement of surface/volume ratios following active caspase-6 intratracheal instillation in mice (48 h) in the presence of Lac-Z-AAV (vector) empty or overexpressing MM-A1AT, or ZZ-A1AT for 4 wks. Mean + SEM; n = 10.