Altered expression of iron regulatory proteins with aging is associated with transient hepatic iron accumulation after environmental heat stress

Steven A Bloomer; Okhee Han; Kevin C Kregel; Kyle E Brown

doi:10.1016/j.bcmd.2013.07.002

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Altered expression of iron regulatory proteins with aging is associated with transient hepatic iron accumulation after environmental heat stress

Journal article

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Altered expression of iron regulatory proteins with aging is associated with transient hepatic iron accumulation after environmental heat stress

Steven A Bloomer, Okhee Han, Kevin C Kregel and Kyle E Brown

Blood cells, molecules, & diseases, Vol.52(1), pp.19-26

01/2014

DOI: 10.1016/j.bcmd.2013.07.002

PMCID: PMC3851592

PMID: 23900040

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Abstract

An increasing body of evidence suggests that dysregulation of iron metabolism contributes to age-related pathologies. We have previously observed increased hepatic iron with aging, and that environmental heat stress stimulates a further increase in iron and oxidative liver injury in old rats. The purpose of this study was to determine a mechanism for the increase in hepatic iron in old rats after heat stress. Young (6mo) and old (24mo) Fischer 344 rats were exposed to two heating bouts separated by 24h. Livers were harvested after the second heat stress, and protein levels of the iron import protein, transferrin receptor-1 (TFR1), and the iron export protein, ferroportin (Fpn) were determined by immunoblot. In the nonheated condition, old rats had lower TFR1 expression, and higher Fpn expression. After heat stress, TFR1 declined in the old rats, and iron chelation studies demonstrated that this decline was dependent on a hyperthermia-induced increase in iron. TFR1 did not change in the young rats after heat stress. Since TFR1 is inversely regulated by iron, our results suggest that the increase in intracellular iron with aging and heat stress lower TFR1 expression. Fpn expression increased in both age groups after heat stress, but this response was delayed in old rats. This delay in the induction of an iron exporter suggests a mechanism for the increase in hepatic iron and oxidative injury after heat stress in aged organisms.

Aging

Hyperthermia

Ferroportin

TFR1

DMT1

Deferoxamine

Details

Title: Subtitle: Altered expression of iron regulatory proteins with aging is associated with transient hepatic iron accumulation after environmental heat stress
Creators: Steven A Bloomer - Division of Science and Engineering, Penn State Abington College, Abington, PA 19001, USA
Okhee Han - Department of Nutritional Sciences, Pennsylvania State University, University Park, PA 16802, USA
Kevin C Kregel - Department of Health and Human Physiology, The University of Iowa, Iowa City, IA 52242, USA
Kyle E Brown - Iowa City Veterans Administration Medical Center, Iowa City, IA 52242, USA
Resource Type: Journal article
Publication Details: Blood cells, molecules, & diseases, Vol.52(1), pp.19-26
DOI: 10.1016/j.bcmd.2013.07.002
PMID: 23900040
PMCID: PMC3851592
NLM abbreviation: Blood Cells Mol Dis
ISSN: 1079-9796
eISSN: 1096-0961
Publisher: Elsevier Inc
Language: English
Date published: 01/2014
Academic Unit: Gastroenterology and Hepatology; Radiation Oncology; Provost Office Administration; Health, Sport, and Human Physiology ; Internal Medicine
Record Identifier: 9984046923502771

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