Comparative Immunology, Microbiology & Infectious Diseases 30 (2007) 55–69 Channel catfish hepcidin expression in infection and anemia Xueyou Hu a , Alvin C. Camus b,1 , Shelly Aono a , Edward E. Morrison a , John Dennis a , Kenneth E. Nusbaum c , Robert L. Judd a , Jishu Shi a,à a Department of Anatomy, Physiology and Pharmacology, 212 Greene Hall, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA b Aquatic Diagnostic Laboratory, College of Veterinary Medicine, Mississippi State University, Stoneville, MS, USA c Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA Accepted 13 October 2006 Abstract Hepcidin, originally identified as a 25 amino acid antimicrobial peptide made in the liver, is a key regulator of iron balance and recycling in humans and mice. Closely related hepcidin genes and peptides have also been identified in a number of fish species and in teleosts are thought to function as endogenous antibiotics involved in host defense against infection. Here we report the transcriptional regulation of hepcidin expression by infection and anemia in the channel catfish. Changes in hepcidin expression in catfish challenged with Edwardsiella ictaluri and in fish affected by channel catfish anemia (CCA) were measured by real time quantitative PCR. Hepcidin transcript levels in the livers were increased 4, 19, and 22-fold at 4, 24, and 48 h following bacterial challenge, respectively. However, augmented hepcidin expression in the intestine and olfactory sac was detected only at 48 h post-infection. Hepcidin transcript levels in the livers of catfish affected by CCA were less than 14% of that present in healthy ARTICLE IN PRESS www.elsevier.com/locate/cimid 0147-9571/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.cimid.2006.10.004 Abbreviations: CCA, channel catfish anemia; HH, hereditary hemochromatosis; LPS, lipopolysaccharide; DMT-1, divalent metal transporter à Corresponding author. Tel.: +1 334 844 0726; fax: +1 334 844 5388. E-mail address: shijish@vetmed.auburn.edu (J. Shi). 1 Current address: Department of Veterinary Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia.