Fig. 1.

Effect of inhibitors on divalent metal transporter-1 (DMT1)-mediated iron uptake. Four compounds previously identified to inhibit NTBI uptake were studied. A: structures of the 4 compounds. B: Western blot detecting DMT1 immunoreactivity in HEK293T(DMT1) cells stably transfected with pMT2 containing DMT1 cDNA in the sense and antisense (noncoding) orientation. C: effects of inhibitors on DMT1-mediated ⁵⁵Fe uptake. Briefly, HEK293T(DMT1) cells were incubated either with 50 μM of the indicated compounds or DMSO (vehicle control) in uptake buffer (pH 6.75) containing 1 μM ⁵⁵Fe and 50 μM ascorbic acid for 20 min. Cells were chilled on ice, collected on nitrocellulose filters, and washed with PBS. Cell-associated radioactivity was determined by dissolving the filters in scintillation fluid and counting. All cpm were normalized to vehicle control (112.7 ± 4.4 pmol ⁵⁵Fe/million cells). Shown are mean values ± SE for inhibition (n = 5 or 6). *P = 6.98 × 10⁻⁰⁸; **P = 0.00476.