Iron Regulation in Airway Epithelial Cells

BEAS-2B cells were grown in 12-well plates and exposed (3 wells per plate each) to (a) media alone, (b) 200 μM FAC, (c) 1000 μg/mL NAN (the predominant sialic acid in human cells and respiratory secretions), 1000 μg/mL sodium alginate (a polymer composed of mannuronate and guluronate monosaccharides), 1000 μM sodium guluronate (a uronate), or 1000 μM sodium hyaluronate (a polymer of disaccharides composed of glucuronate and N-acetyl-d-glucosamine) and (d) both 200 μM FAC and 1000 μg/mL NAN, 1000 μg/mL sodium alginate, 1000 μM sodium guluronate, or 1000 μM sodium hyaluronate. After 24 h incubation, the cells were gently washed, scraped into 10% trichloroacetic acid dissolved in 1.0 mL of 3 N HCl, digested at 70 °C, and non-heme iron concentrations were determined using ICPOES operated at a wavelength of 238.204 nm. Exposures of the BEAS-2B cells were repeated to (a) media alone, (b) 200 μM FAC, (c) 1000 μg/mL sodium alginate, and (d) both 200 μM FAC and sodium alginate for 24 h, the media was removed, cells were scraped into 0.5 mL DPBS and disrupted, and the ferritin concentrations quantified using an immunoturbidimetric assay.