Fig. 5

Effects of treatment of Caco-2 cell monolayers with a basolateral supply of holo-Tf or an apical supply of ferric NTA on whole-cell and cell surface levels of proteins responsible for transport of iron across the basolateral membrane of enterocytes. Relative protein levels for whole-cell TfR-1 (a), cell surface TfR-1 (b), whole-cell FPN (c) and cell surface FPN (d) in Caco-2 cells determined at day 21 post-seeding following incubation from day 14 to 21 of confluent Caco-2 cell monolayers established in bicameral chamber with medium containing metal-depleted FBS in the absence of any added iron (Control), the presence of 10 μM ferric NTA added to the apical side of the cells only (10 μM FeNTA) or 30 μM holo-Tf added to the basolateral side of the cells only (30 μM holo-Tf). Insets above each graph depict and an example of the one of the western blots from which the data for the graph were generated. Bars and error bars in the graphs indicate mean + SD (n = 6 comprised of samples generated from 2 wells for each treatment from each of 3 separate plates set up in parallel). Data were compared by one-way ANOVA with Tukey’s post hoc test. Asterisks indicate statistically significant differences between treatments (*p < 0.05 and **p < 0.01)