Fig. 3.

Megalin and cubilin receptor knockdown impair albumin uptake but not reactive oxygen species (ROS) production in response to albumin ligands. A: equal amounts of lysate from cells transfected with control, megalin, or cubilin siRNA were blotted with antibodies against megalin or cubilin. B: albumin uptake (1-h incubation, corrected for protein recovery) was quantified in cells transfected with control, megalin, or cubilin siRNA uptake. Means ± SD of triplicate samples are plotted. ****P ≤ 0.0001 vs. control siRNA by one-way ANOVA (Dunnett’s multiple-comparisons test). C: aconitase activity was measured in cells transfected with the indicated siRNA and incubated for 18 h. Means and SDs are plotted; each point represents the mean of duplicate samples from 4 independent experiments. D: protein recovery was quantified in cells transfected with the indicated siRNA and incubated for 18 h in serum-free medium without (control) or with 20 mg/mL apically added fatty acid-free (FAF-BSA) or palmitate-loaded BSA (Palm-BSA). Means and SDs are plotted; each point represents the mean of duplicate samples from 4 independent experiments. ***P ≤ 0.0005 and ****P ≤ 0.0001 by two-way ANOVA (Dunnett’s multiple-comparisons test).