Five different piscidins from Nile tilapia, Oreochromis niloticus: analysis of their expressions and biological functions

• Published in: PloS one 2012-11, Vol.7 (11), p.e50263-e50263
• Main Authors: Peng, Kuan-Chieh, Lee, Shu-Hua, Hour, Ai-Ling, Pan, Chieh-Yu, Lee, Lin-Han, Chen, Jyh-Yih
• Format: Article
• Language: English
• Subjects: Agriculture; Amino Acid Sequence; Amino acids; Analysis; Animals; Antiinfectives and antibacterials; Antimicrobial agents; Antimicrobial Cationic Peptides - genetics; Antimicrobial Cationic Peptides - isolation & purification; Antimicrobial Cationic Peptides - pharmacology; Antimicrobial peptides; Aquaculture; Bacteria; Bacterial infections; Bass; Biology; Candida albicans; Cationic peptides; Cell proliferation; Cell Proliferation - drug effects; Cells, Cultured; Cichlids - genetics; Cichlids - immunology; Cichlids - microbiology; Cloning; Cod; Coding; Drug development; Expressed Sequence Tags; Female; Fish; Fish Diseases - genetics; Fish Diseases - immunology; Fish Diseases - microbiology; Fish Proteins - genetics; Fish Proteins - isolation & purification; Fish Proteins - pharmacology; Fishes; Gene expression; Gene Expression Regulation; Genomics; Gills; Gills - immunology; Gills - microbiology; Health aspects; Injection; Kidneys; Liver; Molecular Sequence Data; Morone chrysops; Morone saxatilis; Open Reading Frames; Oreochromis niloticus; Ovary - cytology; Ovary - drug effects; Peptides; Polymerase chain reaction; R&D; Research & development; RNA; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; Skin; Spleen; Spleen - immunology; Spleen - microbiology; Staphylococcus infections; Stimulation; Streptococcal Infections - immunology; Streptococcal Infections - microbiology; Streptococcal Infections - veterinary; Streptococcus agalactiae; Streptococcus agalactiae - growth & development; Streptococcus infections; Synthesis; Tilapia; Tissue analysis; Transcription; Veterinary Science; Vibrio Infections - immunology; Vibrio Infections - microbiology; Vibrio Infections - veterinary; Vibrio vulnificus - growth & development; Waterborne diseases
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0050263

Piscidins are antimicrobial peptides (AMPs) that play important roles in helping fish resist pathogenic infections. Through comparisons of tilapia EST clones, the coding sequences of five piscidin-like AMPs (named TP1∼5) of Nile tilapia, Oreochromis niloticus, were determined. The complete piscidin coding sequences of TP1, -2, -3, -4, and -5 were respectively composed of 207, 234, 231, 270, and 195 bases, and each contained a translated region of 68, 77, 76, 89, and 64 amino acids. The tissue-specific, Vibrio vulnificus stimulation-specific, and Streptococcus agalactiae stimulation-specific expressions of TP2, -3, and -4 mRNA were determined by a comparative RT-PCR. Results of the tissue distribution analysis revealed high expression levels of TP2 mRNA in the skin, head kidneys, liver, and spleen. To study bacterial stimulation, S. agalactiae (SA47) was injected, and the TP4 transcript was upregulated by >13-fold (compared to the wild-type (WT) control, without injection) and was 60-fold upregulated (compared to the WT control, without injection) 24 h after the S. agalactiae (SA47) injection in the spleen and gills. Synthesized TP3 and TP4 peptides showed antimicrobial activities against several bacteria in this study, while the synthesized TP1, -2, and -5 peptides did not. The synthesized TP2, -3, and -4 peptides showed hemolytic activities and synthesized TP3 and TP4 peptides inhibited tilapia ovary cell proliferation with a dose-dependent effect. In summary, the amphiphilic α-helical cationic peptides of TP3 and TP4 may represent novel and potential antimicrobial agents for further peptide drug development.