Figure 1.

A) Hif-1 α protein expression in whole cell lysates of H9c2 cells transfected with either pEGFP or pcDNA3-HA-HIF-1α and subjected to normoxia or hypoxia for 12 h. Immunoblotting with antibodies against HIF-1β, the nuclear dimerization partner of HIF-1α was used to monitor equal protein loading. B) HIF-1α mediates hypoxia-induced apoptosis in H9c2 cells transfected with pEGFP or pcDNA3-HA-HIF-1α expressing the wild type HIF-1α or pcDNA3-Flag-DN-HIF-1α expressing the dominant negative version as described in methods. Cells were exposed to normoxia or hypoxia for 12 h in glucose-deficient medium. The number of cells displaying condensed and fragmented nuclei was counted only in cells positive for each respective epitope tag or EGFP. The results are representative of five independent experiments. *P < 0.01 vs. hypoxia in pEGFP and pcDNA3-HA-Hif-1α.