Altered expression of iron regulatory proteins with aging is associated with transient hepatic iron accumulation after environmental heat stress.
Blood Cells Mol Dis
; 52(1): 19-26, 2014 Jan.
Article
em En
| MEDLINE
| ID: mdl-23900040
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 (6 mo) and old (24 mo) Fischer 344 rats were exposed to two heating bouts separated by 24 h. 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.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores da Transferrina
/
Envelhecimento
/
Proteínas de Transporte de Cátions
/
Ferro
/
Fígado
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
Idioma:
En
Revista:
Blood Cells Mol Dis
Assunto da revista:
HEMATOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de publicação:
Estados Unidos