Fig. 3. Ferric ammonium citrate, cytokines and hydrogen peroxide affect ferritin nuclear concentrations in SW 1088 human astrocytoma cells. SW 1088 astrocytoma cells were treated with deferoxamine and then placed in standard media (control) or standard media, including varying concentrations of ferric ammonium citrate (FAC), tumor necrosis factor (TNF), interleukin 1ß (IL-1ß) or hydrogen peroxide (H₂O₂). Nuclear and cytosolic extracts were isolated and ferritin levels were determined using the HO2 monoclonal mouse anti-human rH-ferritin antibody. Ferritin levels are expressed as a percentage of control values. The concentration of the experimental factors is shown at the bottom of each graph. (A) Nuclear and cytosolic ferritin protein levels both increase in response to FAC exposure, but the increase is not concentration dependent. (B) Nuclear ferritin levels are increased in response to TNF, but cytosolic levels are decreased when compared with control at each concentration. (C) Nuclear ferritin levels increase at the lowest dose of IL 1ß, but decrease at the higher doses. The cytosolic levels of ferritin are not different from control. (D) Nuclear ferritin levels increase in response to H₂O₂ only at 100 µM H₂O₂, while cytosolic levels remain constant. The asterisks indicate a statistically significant difference from control values. ^**P<0.001, ^*P<0.05.