Protein Susceptibility to Peroxidation by 4-Hydroxynonenal in Hereditary Hemochromatosis

Iron overload caused by hereditary hemochromatosis (HH) increases free reactive oxygen species that, in turn, induce lipid peroxidation. Its 4-hydroxynonenal (HNE) by-product is a well-established marker of lipid peroxidation since it reacts with accessible proteins with deleterious consequences. Indeed, elevated levels of HNE are often detected in a wide variety of human diseases related to oxidative stress. Here, we evaluated HNE-modified proteins in the membrane of erythrocytes from HH patients and in organs of Hfe(-/-) male and female mice, a mouse model of HH. For this purpose, we used one- and two-dimensional gel electrophoresis, immunoblotting and MALDI-TOF/TOF analysis. We identified cytoskeletal membrane proteins and membrane receptors of erythrocytes bound to HNE exclusively in HH patients. Furthermore, kidney and brain of Hfe(-/-) mice contained more HNE-adducted protein than healthy controls. Our results identified main HNE-modified proteins suggesting that HH favours preferred protein targets for oxidation by HNE.

Automated summary

Iron overload in hereditary hemochromatosis (HH) leads to increased reactive oxygen species and lipid peroxidation. The by-product of lipid peroxidation, 4-hydroxynonenal (HNE), is widely used as a marker and is elevated in various human diseases associated with oxidative stress. In this study, we investigated HNE-modified proteins in erythrocyte membranes from HH patients and in organs of Hfe(-/-) mice, a mouse model of HH. We identified specific proteins bound to HNE in erythrocyte membranes of HH patients and found increased levels of HNE-adducted proteins in the kidneys and brains of Hfe(-/-) mice. These findings suggest that HH preferentially targets certain proteins for oxidation by HNE.