title: Transcriptome analysis of medaka following epinecidin-1 and TH1-5 treatment of NNV infection.
abstract: Nervous necrosis virus (NNV) infects a wide range of larval and juvenile fish species, thereby causing enormous economic losses in the aquaculture industry. Possible solutions to this problem include the use of antimicrobial peptides (AMPs), which directly inhibit bacterial growth, and also modulate host signaling mechanisms. The AMPs epinecidin (Epi)-1 and Tilapia hepcidin (TH) 1-5 have been demonstrated to be effective against Nervous necrosis virus infection in medaka (Oryzias latipes). However, the underlying molecular mechanisms are yet to be explored. Here, microarray analyses were performed to examine how NNV infection and/or epinecidin-1 or TH1-5 treatment affects gene expression in medaka; such analyses enabled the prediction of host signaling pathways affected by virus infection and/or regulated by epinecidin-1 and TH1-5. Transcriptome analysis revealed altered expression of genes involved in B cell activation, T cell activation, adipocytokine signaling, and mast cell activation. We subsequently used real-time PCR to analyze expression of key genes involved in these signaling mechanisms. Medaka infected with NNV exhibited up-regulation of PVALB, CEBPA, IFIM, IFN, IL-6ST, NF-kB2, SOC3, SP1, and TGFB1, and such increases were prevented by pre-treatment with epinecidin-1 or TH1-5. Immunohistochemistry using the anti-NNV antibody to stain brain and eye sections revealed that epinecidin-1 treatment during or after infection clears viral load, while TH1-5 treatment only reduces viral numbers if applied during infection. These observations demonstrate that epinecidin-1 and TH1-5 modulate NNV-induced host signaling mechanisms, thereby preventing viral multiplication in host organisms.
authors.affiliation: Institute of Fisheries Science, National Taiwan University, 1 Roosevelt Road, Sec. 4, Taipei 106, Taiwan.
authors.forename: Yi-Da
authors.initials: YD
authors.lastname: Wang
authors.affiliation: Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, 23-10 Dahuen Rd., Jiaushi, Ilan 262, Taiwan.
authors.forename: Venugopal
authors.initials: V
authors.lastname: Rajanbabu
authors.affiliation: Marine Research Station, Institute of Cellular and Organismic Biology, Academia Sinica, 23-10 Dahuen Rd., Jiaushi, Ilan 262, Taiwan. Electronic address: zoocjy@gate.sinica.edu.tw.
authors.forename: Jyh-Yih
authors.initials: JY
authors.lastname: Chen
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000627:therapeutic use; D005393:Fish Diseases / Q000188:drug therapy* / Q000378:metabolism* / Q000821:virology*; D029941:Fish Proteins / Q000627:therapeutic use; D020869:Gene Expression Profiling / Q000662:veterinary; D064451:Hepcidins / Q000627:therapeutic use; D007150:Immunohistochemistry; D046228:Microarray Analysis; D030381:Nodaviridae / Q000187:drug effects*; D009990:Oryzias; D012327:RNA Virus Infections / Q000188:drug therapy / Q000378:metabolism / Q000662:veterinary*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics; D059467:Transcriptome / Q000235:genetics*
chemical_list: D023181:Antimicrobial Cationic Peptides; D029941:Fish Proteins; D064451:Hepcidins; C521392:epinecidin-1, Epinephelus coioides
keywords: Antimicrobial peptide; Epinecidin-1; Medaka; Nervous necrosis virus; Tilapia hepcidin 1-5