Figure 4.

Take‐up of hemoglobin‐coated or transferrin‐coated NT50 by rat peritoneal mesothelial cells increases the intracellular catalytic Fe(II). After incubating rat peritoneal mesothelial cells with hemoglobin‐coated or transferrin‐coated NT50 (i–iv) or NTtngl with the same coatings (v–viii), the cells were stained with a fluorescent probe (Rhonox‐1) that is highly specific to catalytic Fe(II) (a). Intracellular catalytic Fe(II) was significantly increased only in the case of hemoglobin‐coated or transferrin‐coated NT50, but not NTtngl. The levels of lipid peroxidation were evaluated with an antibody against 4‐hydroxy‐2‐nonenal (HNE)‐modified proteins (b), and lipid peroxidation sensor probe BODIPY (581/591) C₁₁ (c), which were consistent with the amounts of catalytic Fe(II) (N = 3, means ± SEM; *P < 0.05, **P < 0.01, ***P < 0.005, ****P < 0.001 vs control otherwise specified).