HIF-1α expression in human macrophages. Macrophages were incubated under normoxic (N) or hypoxic (H) conditions, or treated with LPS, 100 µM CoCl or 1 mM desferrioxamine (DFO), for 2 hours. HIF-1α protein expression was determined by immunoblotting total nuclear extract. Hypoxia, CoCl and DFO all induce HIF-1α, with no expression under normoxic conditions or following LPS treatment (10A). IL-8 mRNA expression was determined by northern blotting (10B). An 18s housekeeping probe was used to verify equal RNA loading (10C). Relative densitometry, corrected for RNA loading, from n = 3 experiments is shown in panel (10D). Neither CoCl nor DFO mimicked the hypoxia-induced increased in IL-8 mRNA expression.