HIF-1α expression, HIF-1α target gene expression and AP activity of MLO cells subjected to chemical hypoxia. (A) Western blot analysis of HIF-1α expression in MLO-A5 and MLO-Y4 cells treated with 130 m desferrioxamine (DFX) at 20% O2 for 24 h. DFX induced HIF-1α protein expression in both cell types. (B) RT-PCR analysis of Bnip3 and GLUT1 in MLO-A5 and MLO-Y4 cells at 2% and 20% O2, and 20% O2 with DFX. In both cell types, the HIF-1α targets were upregulated by DFX treatment for 8 h at 20% O2. (C) AP activity of MLO-A5 and MLO-Y4 cells treated for 24 h at 2% and 20% O2 with or without DFX. For both cell types at 20% O2, DFX significantly reduced AP activity. Values plotted are mean and SEM. * significantly different from untreated controls, p<0.05; ns denotes non-significant.