Indices of cellular iron status. (A) After the double round of transfections, the content of H-ferritin (FTH) and L-ferritin (FTL) of the cell homogenates was evaluated by ELISA assays, and the data were expressed as nanogram of ferritin per milligram of total proteins. Mean and SD of 10 and of 3 different experiments for FTL and FTH, respectively; the asterisks indicate significant difference (P < .05). (B) The ferritin content of the cell homogenates was evaluated by blotting from SDS-PAGE overlaid with anti–L-ferritin antibody. Actin was used for normalization. (C) Blotting of the cell homogenates with anti–transferrin receptor 1 (TfR1) antibodies. The level of expression relative to the control mock-transfected cells was quantified by gel densitometry in 3 different experiments and shown in the histogram. Data are shown as mean and SD of 3 experiments.