Iron depletion attenuates steatosis in a mouse model of non-alcoholic fatty liver disease: Role of iron-dependent pathways

Abstract

Background & aims: Iron has been proposed as influencing the progression of liver disease in subjects with non-alcoholic fatty liver disease (NAFLD). We have previously shown that, in the Hfe^-/- mouse model of hemochromatosis, feeding of a high-calorie diet (HCD) leads to increased liver injury. In this study we investigated whether the feeding of an iron deficient/HCD to Hfe^-/- mice influenced the development of NAFLD.

Methods: Liver histology was assessed in Hfe^-/- mice fed a standard iron-containing or iron-deficient diet plus or minus a HCD. Hepatic iron concentration, serum transferrin saturation and free fatty acid were measured. Expression of genes implicated in iron regulation and fatty liver disease was determined by quantitative real-time PCR (qRT-PCR).

Results: Standard iron/HCD-fed mice developed severe steatosis whereas NAS score was reduced in mice fed iron-deficient HCD. Mice fed iron-deficient HCD had lower liver weights, lower transferrin saturation and decreased ferroportin and hepcidin gene expression than HCD-fed mice. Serum non-esterified fatty acids were increased in iron-deficient HCD-fed mice compared with standard iron HCD. Expression analysis indicated that genes involved in fatty-acid binding and mTOR pathways were regulated by iron depletion.

Conclusions: Our results indicate that decreasing iron intake attenuates the development of steatosis resulting from a high calorie diet. These results also suggest that human studies of agents that modify iron balance in patients with NAFLD should be revisited.

Keywords: Hemochromatosis; High calorie diet; Iron overload; NAFLD; Steatosis.