Increased iron stores associated with elevated levels of the iron hormone hepcidin are a frequent feature of the metabolic syndrome. The aim of this study was to assess the effect of dietary iron supplementation on insulin resistance and the role of hepcidin in C57Bl/6 male mice fed a standard or iron-enriched diet for 16 weeks. Iron supplementation increased hepatic iron and serum hepcidin fivefold and led to a 40% increase in fasting glucose due to insulin resistance, as confirmed by the insulin tolerance test, and to threefold higher levels of triglycerides. Iron supplemented mice had Lower visceral adipose tissue mass estimated by epididymal fat pad, associated with iron accumulation in adipocytes. Decreased insulin signaling, evaluated by the phospho-Akt/Akt ratio, was detected in the visceral adipose tissue of iron overloaded mice, and gene expression analysis of visceral adipose tissue showed that an iron-enriched diet up-regulated iron-responsive genes and adipokines, favoring insulin resistance, whereas Lipoprotein Lipase was down-regulated. This resulted in hyperresistinemia and increased visceral adipose tissue expression of suppressor of cytokine signaling-3 (Socs3), a target of resistin and hepcidin implicated in insulin resistance. Acute hepcidin administration down-regulated lipoprotein Lipase and up-regulated Socs3 in visceral adipose tissue. In conclusion, we characterized a model of dysmetabolic iron overload syndrome in which an iron-enriched diet induces insulin resistance and hypertriglyceridemia and affects visceral adipose tissue metabolism by a mechanism involving hepcidin up-regulation.
Dietary iron overload induces visceral adipose tissue insulin resistance / P. Dongiovanni, M. Ruscica, R. Rametta, S. Recalcati, L. Steffani, S. Gatti, D. Girelli, G. Cairo, P. Magni, S. Fargion, L. Valenti. - In: THE AMERICAN JOURNAL OF PATHOLOGY. - ISSN 0002-9440. - 182:6(2013 Jun), pp. 2254-2263.
|Titolo:||Dietary iron overload induces visceral adipose tissue insulin resistance|
|Parole Chiave:||fatty liver-disease; metabolic syndrome; oxidative stress; mouse; model; hemochromatosis; steatohepatitis; restriction; ferroportin; sensitivity|
|Settore Scientifico Disciplinare:||Settore MED/04 - Patologia Generale|
Settore MED/09 - Medicina Interna
Settore MED/05 - Patologia Clinica
Settore MED/13 - Endocrinologia
Settore MED/46 - Scienze Tecniche di Medicina di Laboratorio
|Data di pubblicazione:||giu-2013|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1016/j.ajpath.2013.02.019|
|Appare nelle tipologie:||01 - Articolo su periodico|