title: Molecular characterization of hepcidin AS-hepc2 and AS-hepc6 in black porgy (Acanthopagrus schlegelii): expression pattern responded to bacterial challenge and in vitro antimicrobial activity.
abstract: There are more diversified isoforms of the hepcidin gene that exist in fishes than in mammals, and elucidating the differences between these isoforms should provide insight into the functioning of hepcidin in fishes. In our study, AS-hepc2 and AS-hepc6 hepcidin isoforms from black porgy were characterized for their in vivo expression patterns following bacterial challenge, and their in vitro antimicrobial activities against Gram-positive and Gram-negative bacteria as well as fungi. As a result, two isoforms were observed to be widely distributed in all the tissues tested. AS-hepc2 was a liver-expressed hepcidin peptide which was always highly more expressed in the liver than in the other tissues tested no matter whether this was before or after bacterial challenge. AS-hepc6 was detected mainly in the head kidney and trunk kidney of normal fish, but, in the challenged fish, its expression involved more tissues than just the kidneys. The mature peptides of AS-hepc2 and AS-hepc6 were modeled for 3D structure and then synthesized for antimicrobial assay. AS-hepc6 had a wider antimicrobial spectrum than AS-hepc2 and, in particular, had more potent antifungal activity. Our study indicated that the two hepcidin isoforms had different characteristics in terms of their expression patterns and antimicrobial activity, and they were assumed to play an overlapping role in the innate immune system of black porgy against invading pathogens.
authors.affiliation: State Key Laboratory of Marine Environmental Science, College of Oceanography and Environmental Science, Xiamen University, Xiamen, Fujian 361005, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Yang
authors.forename: Bei
authors.initials: B
authors.lastname: Chen
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Cai
authors.forename: Hui
authors.initials: H
authors.lastname: Peng
authors.lastname: Ling-Cai
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Yuan
authors.forename: Ke-Jian
authors.initials: KJ
authors.lastname: Wang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000935:Antifungal Agents / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000096:biosynthesis* / Q000494:pharmacology; D029941:Fish Proteins / Q000096:biosynthesis / Q000378:metabolism* / Q000494:pharmacology; D064451:Hepcidins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009928:Organ Specificity; D020033:Protein Isoforms / Q000096:biosynthesis / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D021541:Sea Bream / Q000378:metabolism* / Q000382:microbiology; D040681:Structural Homology, Protein
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D029941:Fish Proteins; D064451:Hepcidins; D020033:Protein Isoforms