title: Gene expression and localization of the epinecidin-1 antimicrobial peptide in the grouper (Epinephelus coioides), and its role in protecting fish against pathogenic infection.
abstract: Epinecidin-1 is an antimicrobial peptide and plays a vital role in protecting fish against pathogenic infection. As a mimic of a grouper epinecidin-1 peptide, it has tertiary structures that closely resemble those of pleurocidin found in the winter flounder (Pleuronectes americanus). The tissue-specific, lipopolysaccharide (LPS)-stimulation-specific, and poly(I):poly(C)-stimulation-specific expressions of the grouper (Epinephelus coioides) epinecidin-1 antimicrobial peptide were determined using a comparative reverse-transcription polymerase chain reaction. Results of the tissue distribution analysis revealed high levels of epinecidin-1 messenger RNA (mRNA) in the head kidneys, intestines, and skin. Expression of epinecidin-1 mRNA was dose-dependently stimulated by both LPS and poly(I):poly(C). Immunohistochemical analysis with the polyclonal antiserum of a grouper epinecidin-1 peptide (rabbit polyclonal antibody) showed that the peptide was localized with the epinecidin-1 antibody in the gills and intestines. Two synthetic peptides of the grouper epinecidin-1 peptide (g-ple 22-51 and g-ple 22-42) and one winter flounder pleurocidin as a control exhibited high antimicrobial activities against gram-negative or gram-positive bacteria. In addition, peptide treatment was effective in promoting a significant increase in fish survival after the injection of Vibrio vulnificus in tilapia (Oreochromis mossambicus) and grouper. These results are relevant to the design of prophylactic and therapeutic strategies to counter bacterial infections, especially for preventing or ameliorating immune defects in fish during bacterial infections.
authors.affiliation: Department of Environmental Biology and Fisheries Science, National Taiwan Ocean University, Keelung, Taiwan.
authors.forename: Chia-Yu
authors.initials: CY
authors.lastname: Pan
authors.forename: Jyh-Yih
authors.initials: JY
authors.lastname: Chen
authors.forename: Yih-Shyun E
authors.initials: YS
authors.lastname: Cheng
authors.forename: Chun-Yao
authors.initials: CY
authors.lastname: Chen
authors.forename: I-Hsun
authors.initials: IH
authors.lastname: Ni
authors.forename: Jenn-Feng
authors.initials: JF
authors.lastname: Sheen
authors.forename: Yu-Liang
authors.initials: YL
authors.lastname: Pan
authors.forename: Ching-Ming
authors.initials: CM
authors.lastname: Kuo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism* / Q000494:pharmacology; D001424:Bacterial Infections / Q000235:genetics / Q000378:metabolism / Q000517:prevention & control / Q000662:veterinary; D001483:Base Sequence; D001492:Bass / Q000235:genetics* / Q000378:metabolism* / Q000382:microbiology; D017931:DNA Primers / Q000235:genetics; D005393:Fish Diseases / Q000235:genetics* / Q000378:metabolism* / Q000382:microbiology / Q000517:prevention & control; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism* / Q000494:pharmacology; D015870:Gene Expression; D005880:Gills / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D023181:Antimicrobial Cationic Peptides; D017931:DNA Primers; D029941:Fish Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C521392:epinecidin-1, Epinephelus coioides