Figure 5.

Programmed death of BNIP3-transfected cardiac myocytes. Cardiac myocytes were transfected with expression plasmids containing β-Gal plus empty vector, β-Gal with BNIP3, or β-Gal with BNIP3 Δ-TM, as indicated. After 48 h, transfected cultures were exposed to continued normoxic culture or to hypoxia, acidosis, or hypoxia + acidosis as described in Materials and Methods. At the indicated times, plates were rinsed, costained with 5-bromo-4-chloro-3-indolyl β-D-galactoside and Hoechst 33342, and visualized by microscopy. Bars indicate SEM from at least 200 5-bromo-4-chloro-3-indolyl β-D-galactoside-positive cells per condition. *, P < 0.02, and **, P < 0.01, refer to the respective condition compared with aerobic controls. BNIP3 Δ-TM transfection with 8-h hypoxia + acid was significantly different from either β-Gal (P < 0.05) or BNIP3 8-h hypoxia + acid (P < 0.01).