Proteomic analysis of hepatic iron overload in mice suggests dysregulation of urea cycle, impairment of fatty acid oxidation, and changes in the methylation cycle.
Liver iron overload can be found in hereditary hemochromatosis, chronic liver diseases such as alcoholic liver disease, and chronic viral hepatitis or secondary to repeated blood transfusions. The excess iron promotes liver damage, including fibrosis, cirrhosis, and hepatocellular carcinoma. Despite significant research effort, we remain largely ignorant of the cellular consequences of liver iron overload and the cellular processes that result in the observed pathological changes. In addition, the variability in outcome and the compensatory response that likely modulates the effect of increased iron levels are not understood. To provide insight into these critical questions, we undertook a study to determine the consequences of iron overload on protein levels in liver using a proteomic approach. Using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) combined with matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), we studied hepatic iron overload induced by carbonyl iron-rich diet in mice and identified 30 liver proteins whose quantity changes in condition of excess liver iron. Among the identified proteins were enzymes involved in several important metabolic pathways, namely the urea cycle, fatty acid oxidation, and the methylation cycle. This pattern of changes likely reflects compensatory and pathological changes associated with liver iron overload and provides a window into these processes.
Petrak
Jiri
J
Institute of Hematology and Blood Transfusion, U Nemocnice 1, 128 20 Prague, Czech Republic. petra@uhkt.cz
Myslivcova
Denisa
D
Man
Petr
P
Cmejla
Radek
R
Cmejlova
Jana
J
Vyoral
Daniel
D
Elleder
Milan
M
Vulpe
Christopher D
CD
D000818:Animals; D004195:Disease Models, Animal; D015180:Electrophoresis, Gel, Two-Dimensional; D004798:Enzymes / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D058085:Iron Compounds; D019190:Iron Overload / Q000139:chemically induced / Q000150:complications* / Q000378:metabolism / Q000473:pathology; D008099:Liver / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D008107:Liver Diseases / Q000201:enzymology / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008745:Methylation; D051379:Mice; D008810:Mice, Inbred C57BL; D010084:Oxidation-Reduction; D040901:Proteomics / Q000379:methods*; D012720:Severity of Illness Index; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014508:Urea / Q000378:metabolism*
D004798:Enzymes; D005227:Fatty Acids; D058085:Iron Compounds; C515100:iron pentacarbonyl; D014508:Urea