Iron Overload Is Associated With Oxidative Stress and Nutritional Immunity During Viral Infection in Fish.

Estefanía Tarifeño-Saldivia,Luis Mercado,David Contreras,Byron Morales-Lange,Andrea Aguilar,Camila Riquelme-Vidal,Sebastian Boltana,Katherine Márquez,Adolfo Henríquez

doi:10.3389/fimmu.2018.01296

Abstract

Iron is a trace element, essential to support life due to its inherent ability to exchange electrons with a variety of molecules. The use of iron as a cofactor in basic metabolic pathways is essential to both pathogenic microorganisms and their hosts. During evolution, the shared requirement of micro- and macro-organisms for this important nutrient has shaped the pathogen–host relationship. Infectious pancreatic necrosis virus (IPNv) affects salmonids constituting a sanitary problem for this industry as it has an important impact on post-smolt survival. While immune modulation induced by IPNv infection has been widely characterized on Salmo salar, viral impact on iron host metabolism has not yet been elucidated. In the present work, we evaluate short-term effect of IPNv on several infected tissues from Salmo salar. We observed that IPNv displayed high tropism to headkidney, which directly correlates with a rise in oxidative stress and antiviral responses. Transcriptional profiling on headkidney showed a massive modulation of gene expression, from which biological pathways involved with iron metabolism were remarkable. Our findings suggest that IPNv infection increase oxidative stress on headkidney as a consequence of iron overload induced by a massive upregulation of genes involved in iron metabolism.

Highlights

Iron is a functional constituent of proteins involved in a wide range of biological process including oxygen transport, energy production, and DNA synthesis, becoming essential for most organisms [1, 2]
We have evaluated the effect of Infectious pancreatic necrosis virus (IPNv) infection on post-smolt Salmon salar after 24 h post-challenge
High tropism of IPNv for headkidney, spleen, and pancreas was already described by Munang’andu and colleagues [37], the viral load on this study was evaluated only from 7 days post-challenge leading uncovered the early stages of infection in Salmo salar

Summary

Introduction

Iron is a functional constituent of proteins involved in a wide range of biological process including oxygen transport, energy production, and DNA synthesis, becoming essential for most organisms [1, 2]. Iron Overload and Virus Infection in Fish of reactive oxygen species (ROS) responsible for tissue damage [2, 4]. To avoid these negative effects, iron is available coupled with proteins such as transferrin (tf), lactoferrin (lf), ferritin, and hemoproteins as haemo- or haptoglobin [2, 5, 6]. Iron absorption must be highly regulated to avoid toxic overloads [3]. Hepcidin gene transcription is regulated by iron levels, a rise on the iron level in plasma induce upregulation hepcidin mRNAs [10], in contrast, when iron level are restricted expression of hepcidin is inhibited and, iron is released from tissues [11]

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Results

Conclusion