Iron chelation inhibits NF-κB-mediated adhesion molecule expression by inhibiting p22phox protein expression and NADPH oxidase activity

Objective - Excess iron may increase oxidative stress and play a role in vascular inflammation and atherosclerosis. Here we determined whether the iron chelator, desferrioxamine (DFO), ameliorates oxidative stress and cellular adhesion molecule expression in a murine model of local inflammation. Methods and Results - Dorsal air pouches were created in C57BL/6J mice by subcutaneous injection of air. DFO (100 mg/kg body weight) was injected into the air pouch once a day for two days followed immediately on the second day by lipopolysaccharide (LPS; 2.5 mg/kg body weight). The animals were euthanized 24 hours later for analysis of oxidative stress markers and adhesion molecules in air pouch tissue. LPS treatment enhanced protein levels of p22(phox), a catalytic subunit of NADPH oxidase, and increased NADPH oxidase activity and levels of superoxide radicals and hydrogen peroxide. Furthermore, LPS activated NF-kappa B and increased expression of adhesion molecules. All of these inflammatory responses were strongly suppressed by DFO, but not iron-loaded DFO. Conclusions - Our data show that DFO inhibits LPS-induced, NADPH oxidase-mediated oxidative stress and, hence, NF-kappa B activation and adhesion molecule expression in a murine model of local inflammation. Iron chelation may be helpful in treating atherosclerotic vascular diseases by ameliorating oxidative stress and inflammation.