RNA and protein changes of core antioxidant and iron metabolism genes responsive to the interactive effects of dexamethasone and Hb. Monocytes were primed with dexamethasone for 36 hours (■) or left untreated () and then incubated with medium containing 50% autologous serum (c), 400 μg/mL HbA₀ (Hb), or 400 μg/mL tetramer-stabilized α-α crosslinked Hb (αα). Cells were treated with Hb for 12 hours before mRNA analysis or incubated for 24 hours for determination of intracellular reduced GSH and ferritin or Western blot analysis. (A) Changes in mRNA expression of GCLM (left) and level of Hb-induced intracellular GSH (right) in dexamethasone-primed monocytes. (B) mRNA and protein expression levels of heme oxygenase (HO-1) (left and lower) and intracellular ferritin levels (right). (C) mRNA and protein levels of the transferrin receptor (TfR1) and the iron exporter ferroportin (Fpn1). All quantitative results represent mean ± SEM of at least 3 independent experiments.