Figure 1.

Nonheme ⁵⁷Fe concentrations in nuclear and mitochondrial fractions, cell iron, and ferritin concentrations after exposure to WSP. Cells were incubated with ⁵⁷Fe FAC and exposed to 100 or 200 μg/mL WSP (WPS 100 and WPS 200, respectively) for 15 min. Collected fractions were hydrolyzed, and ICPMS was employed to measure ⁵⁷Fe. After WSP exposure, ⁵⁷Fe concentrations were increased in the nuclear fraction and decreased in the mitochondrial fraction (A). Cells were incubated with FAC followed by ⁵⁷Fe FAC, and the exposures were repeated. Relative to PBS exposure, there were no differences in ⁵⁷Fe in either the nuclear or the mitochondrial fraction after WSP (B). With exposure to 200 μM FAC, cells imported iron with increased nonheme iron concentrations at 4 h by ICPOES (C). Inclusion of 100 or 200 μg/mL WSP also elevated cell iron concentrations. However, coexposure to both FAC and WSP further increased cell metal levels to their highest levels. Exposures were repeated for 24 h, and ferritin was measured in cell lysate using an immunoturbidimetric assay. Exposures to FAC, 100 μg/mL, or 200 μg/mL WSP, or both increased cell ferritin concentration, but coexposure was associated with the greatest elevation in levels of the storage protein (D). In (A) and (B), * indicates a significant increase relative to the same fraction collected from BEAS-2B cells exposed to PBS, and ** indicates a significant decrease relative to the same fraction collected from BEAS-2B cells exposed to PBS. In (C) and (D), * indicates a significant increase relative to BEAS-2B cells exposed to PBS, and ** indicates a significant increase relative to BEAS-2B cells exposed to either FAC alone or WSP alone.