DEFEROXAMINE BUT NOT DEXRAZOXANE ALLEVIATES LIVER INJURY INDUCED BY ENDOTOXEMIA IN RATS Jolana Cermanova,* Zuzana Kadova,* Eva Dolezelova, † Marie Zagorova,* Vaclav Safka, ‡ Milos Hroch,* § Tomas Laho,* Magdalena Holeckova, || Jaroslav Mokry, ¶ Petra Kovarikova,** Jan Bures,** Martin Sterba,* and Stanislav Micuda* *Department of Pharmacology, Charles University in Prague, Faculty of Medicine, † Department of Biological and Medical Sciences, Charles University Prague, Faculty of Pharmacy, ‡ Departments of Physiology and § Medical Biochemistry, || Institute of Clinical Biochemistry and Diagnostics, and ¶ Department of Histology and Embryology, Charles University in Prague, Faculty of Medicine, and **Department of Pharmaceutical Chemistry and Drug Analysis, Charles University Prague, Faculty of Pharmacy, Hradec Kralove, Czech Republic Received 10 Jan 2014; first review completed 31 Jan 2014; accepted in final form 7 May 2014 ABSTRACT—The purpose of the present study was to compare the activity of two different clinically available iron chelators on the development of acute liver injury after administration of the bacterial endotoxin (lipopolysaccharide [LPS]) in rats. Lipopolysaccharide was administered either alone or after pretreatment with dexrazoxane (DEX) or deferoxamine (DFO). Control groups received only saline or its combination with either chelator. After 8 h, untreated LPS rats developed liver injury, with signs of inflammation and oxidative stress. Lipopolysaccharide reduced plasma iron concentrations in associ- ation with increased production of hepcidin and the reduced liver expression of ferroportin. Administration of chelating agents to LPS animals showed distinct effects. Although both drugs were able to reduce liver iron content, together with corresponding changes in hepcidin and ferroportin expressions, only DFO showed a protective effect against liver injury despite relatively small liver concentrations. In sharp contrast, DEX failed to improve any hallmark of liver injury and even worsened the GSH/GSSG ratio, the indicator of oxidative stress in the tissue. High-performance liquid chromatographyYmass spectrometry analysis showed marked liver accumulation of iron-chelating metabolite of DEX (ADR- 925), whereas the parent compound was undetectable. Further downregulation of transporters involved in bile forma- tion was observed after DFO in the LPS group as well as in healthy animals. Neither chelator imposed significant liver injury in healthy animals. In conclusion, we demonstrated marked differences in the modulation of endotoxemic liver impair- ment between two iron chelators, implicating that particular qualities of chelating agents may be of crucial importance. KEYWORDS—Deferoxamine, dexrazoxane, endotoxin, iron, liver impairment INTRODUCTION The liver is one of the central organs for the onset, modulation, and termination of systemic toxicity produced by gram-negative bacteria during the sepsis (1). The molecules, which significantly contribute to the impairment imposed by these bacteria, are lipo- polysaccharide (LPS) endotoxins, the major components of their outer membrane. In the liver, LPS binds to Toll-like receptors (TLRs) at the Kupffer cells and induces the production of nitric oxide (NO) and proinflammatory cytokines such as tumor ne- crosis factor-! (TNF-!), interkeukin-1" (IL-1"), and IL-6. These molecules, together with the direct effect of cumulating leukocytes and LPS (2), subsequently induce a stress response of hepatocytes characterized by generation of reactive oxygen species and corre- sponding protein and lipid membrane impairment (3). Hepatocel- lular damage is further worsened by downregulation of transporters responsible for bile acidYdependent, as well as Yindependent, bile production with consequent intrahepatic cholestasis (4). Recent advances strongly suggest that the liver may signifi- cantly modulate the pathophysiology of sepsis/endotoxemia among others by targeting iron metabolism. Bacteria require sufficient plasma concentration of free iron for proper prolifera- tion. One of the spontaneous defense mechanisms against bacte- rial growth is, therefore, a reduction of iron plasma levels, which is regularly seen during inflammatory situations (2). This effect is mediated by increased liver production of the main iron- regulating peptideVhepcidin (5). Unsurprisingly, hepcidin was first identified as an antimicrobial peptide in plasma and urine (6) but, consequently, it was described as the main suppressor of iron absorption in the duodenum and inducer of intracellular iron se- questration in hepatocytes and macrophages. High hepcidin pro- duction, therefore, leads to a reduction of the iron in the serum. At the molecular level, hepcidin binds to ferroportin, the only ex- porter of iron from the cells, with subsequent internalization of the transporter and its degradation. Although the principal pathway upregulating hepcidin production is the iron-sensitive BMP- SMAD (bone morphogenetic proteinYson of mothers against decapentaplegic) cascade, its synthesis is also induced during the inflammation by cytokine IL-6, which in turn activates pSTAT3- controlled transcription (7). Thus, the intracellular labile iron pool consequently increases during endotoxemia, which may contribute 372 SHOCK, Vol. 42, No. 4, pp. 372Y379, 2014 Address reprint requests to Stanislav Micuda, MD, PhD, Department of Pharmacology, Charles University of Prague, Faculty of Medicine, Hradec Kralove, Simkova 870, 500 38 Hradec Kralove, Czech Republic. E-mail: micuda@lfhk.cuni.cz. This project was supported by a grant from Charles University (Prvouk P37/05 and SVV-2013-266901). Supplemental digital content is available for this article. Direct URL citation appears in the printed text and is provided in the HTML and PDF versions of this article on the journal_s Web site (www.shockjournal.com). DOI: 10.1097/SHK.0000000000000210 Copyright Ó 2014 by the Shock Society Copyright © 2014 by the Shock Society. Unauthorized reproduction of this article is prohibited.