Gene expression and localization of the epinecidin-1 antimicrobial peptide in the grouper (Epinephelus coioides), and its role in protecting fish against pathogenic infection.
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.
Pan
Chia-Yu
CY
Department of Environmental Biology and Fisheries Science, National Taiwan Ocean University, Keelung, Taiwan.
Chen
Jyh-Yih
JY
Cheng
Yih-Shyun E
YS
Chen
Chun-Yao
CY
Ni
I-Hsun
IH
Sheen
Jenn-Feng
JF
Pan
Yu-Liang
YL
Kuo
Ching-Ming
CM
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
D023181:Antimicrobial Cationic Peptides; D017931:DNA Primers; D029941:Fish Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C521392:epinecidin-1, Epinephelus coioides