title: Inflammatory immune response by lipopolysaccharide-responsive nucleotide binding oligomerization domain (NOD)-like receptors in the Japanese pufferfish (Takifugu rubripes).
abstract: Some of NOD-like receptors (NLRs), the cytosolic pattern recognition receptors form a multi-protein complex, inflammasome consisting of one or more NLRs, the adaptor protein ASC and inflammatory caspase to generate mature inflammatory cytokines, interleukin (IL)-1β and IL-18. However, inflammasome-mediated inflammatory cascade involving any NLR member is unknown in a lower vertebrate like fish. Also, inflammatory cytokine induction pathway in response to a specific ligand, namely bacterial lipopolysaccharide (LPS) has not yet been clarified. Therefore, 13 predicted NLR sequences of the Japanese pufferfish, Fugu (Takifugu rubripes) were retrieved in silico and categorized as NLR-C1∼13. Expression analysis of these genes in Fugu head kidney (HK) cells stimulated with a heat-killed Lactobacillus paracasei spp. paracasei (Lpp), LPS, nigericin and a combination of nigericin + LPS showed consistent up-regulations of NLR-C1, 5, 7, 10 and 12 genes in both Lpp and LPS stimulations and NLR-C9 gene in LPS stimulation only. However, nigericin and nigericin + LPS caused an increased expression of NLR-C10 and 12 in HK cells and leukocytes. Fugu treated with Lpp and LPS (in vivo), and infected with Vibrio harveyi had an elevated expression of NLR-C10 and 12. Increased transcription of caspase-1, ASC, IL-1β and IL-18 was recorded in nigericin-stimulated HK cells and leukocytes. Results suggested activation of probable inflammasome-mediated inflammatory cytokine response in Fugu. Moreover, LPS may be a key ligand that induces some of the Fugu NLR-Cs (NLR-C9, 10 and 12). Further characterization and functional analysis of Fugu NLR-C10 and 12 for ligand sensing, and processing of pro-inflammatory cytokine, IL-1β would elucidate the inflammasome evolution in fish.
authors.affiliation: Interdisciplinary Graduate School of Agriculture and Engineering, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan.
authors.forename: Gouranga
authors.initials: G
authors.lastname: Biswas
authors.affiliation: Department of Basic Sciences, Faculty of Fisheries, Kastamonu University, Kastamonu 37200, Turkey.
authors.forename: Soner
authors.initials: S
authors.lastname: Bilen
authors.affiliation: Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan.
authors.forename: Tomoya
authors.initials: T
authors.lastname: Kono
authors.affiliation: Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sakai
authors.affiliation: Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadai-nishi, Miyazaki 889-2192, Japan. Electronic address: jhikima@cc.miyazaki-u.ac.jp.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Hikima
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D002478:Cells, Cultured; D019295:Computational Biology; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D060226:Head Kidney / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000276:immunology*; D007778:Lactobacillus / Q000276:immunology*; D007962:Leukocytes / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D008969:Molecular Sequence Data; D009550:Nigericin / Q000276:immunology; D053472:Nod Signaling Adaptor Proteins / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D023721:Tetraodontiformes / Q000276:immunology*; D014733:Vibrio / Q000276:immunology*; D014735:Vibrio Infections / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D029941:Fish Proteins; D008070:Lipopolysaccharides; D053472:Nod Signaling Adaptor Proteins; D009550:Nigericin
keywords: Inflammasome; Inflammatory cytokines; Intracellular PRRs; Japanese pufferfish; LPS recognition; NLR