HIF-1α mRNA and protein accumulation in macrophages by CM. (A) RAW264.7 cells were treated with the supernatant of apoptotic Jurkat cells (CM_AC-J) for 4 to 24 hours. (B) RAW264.7 cells were treated with CM_AC-J, 1 mM DMOG, or the combination of both for 16 hours. Relative expression of HIF-1α and actin was followed by Western blot analysis. Results are representative for 3 individual experiments. (C) RAW264.7 cells were treated with CM_AC-J for 1 to 24 hours. (D) RAW264.7 cells were treated with CM_AC-J, the supernatant of necrotic (CM_NC-J) or viable (CM_VC-J) Jurkat cells as well as CM_AC-4T1 for 16 hours. HIF-1α as well as ribosomal 16S protein mRNA were determined by qRT-PCR. The ratio of HIF-1α versus ribosomal 16S protein mRNA under control conditions was set to 1. (E) RAW264.7 cells were transfected with the HIF-1α–luciferase promoter plasmid and treated with 10 μg/mL LPS, CM_AC-J, or CM_AC-MCF7 for 16 hours. Luciferase activity was measured and normalized to protein. Control conditions were set to 1. Data (C-E) are the mean ± SD (n ≥ 3). *Significant alterations compared with controls.