Estrogen suppresses cardiac IL-6 after trauma-hemorrhage via a hypoxia-inducible factor 1α-mediated pathway

Eike A. Nickel, Chi Hsun Hsieh, Jianguo G. Chen, Martin G. Schwacha, Irshad H. Chaudry

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

Cardiac dysfunction is a major concern after trauma-hemorrhage, and increased IL-6 is one of the underlying causes for producing the dysfunction. Studies have shown that administration of 17β-estradiol (estrogen) after traumahemorrhage normalized cardiac IL-6 levels and restored cardiac functions under those conditions. Because hypoxia-inducible factor (HIF) 1α is expressed during hypoxia and cellular stress and up-regulates the expression of IL-6, we hypothesized that HIF-1 α induces the increased cardiac IL-6 after trauma-hemorrhage and that estrogen suppresses this induction. To examine this, C3H/HeN mice were subjected to trauma-hemorrhage or sham operation. Vehicle, the HIF-α inhibitor YC-1 [3-(5'- hydroxymethyl-2'-furyl)-1- benzylindazole, a novel activator of platelet guanylate cyclase], or estrogen was administered to trauma-hemorrhage and sham groups during resuscitation. Mice were killed at 2 h after resuscitation, and cardiac IL-6, HIF-1α, and nuclear factor (NF) κB activities were measured. IL-6, NF-κB, and HIF-1α levels were markedly elevated after trauma-hemorrhage; all of these parameters were normalized by estrogen as well as YC-1 administration after traumahemorrhage. Because elevated IL-6 levels after trauma-hemorrhage were decreased with YC-1 treatment, it indicates that IL-6 expression in cardiomyocytes is induced via HIF-1α. In addition, estrogen decreased the elevated HIF-1 α, NF-κB, and IL-6 levels after trauma-hemorrhage. These results indicate that the beneficial effects of estrogen on cardiac function after trauma-hemorrhage seem to be mediated by the inhibition of HIF-1α expression and activity.

Original languageEnglish (US)
Pages (from-to)354-358
Number of pages5
JournalShock
Volume31
Issue number4
DOIs
StatePublished - Apr 2009
Externally publishedYes

Keywords

  • Cardiac function
  • Cytokine
  • HIF-1 α inhibitor
  • NF-κB

ASJC Scopus subject areas

  • Emergency Medicine
  • Critical Care and Intensive Care Medicine

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