title: Thiamin deficiency induces impaired fish gill immune responses, tight junction protein expression and antioxidant capacity: Roles of the NF-κB, TOR, p38 MAPK and Nrf2 signaling molecules.
abstract: In this study, we investigate the effects of dietary thiamin deficiency on immune responses, tight junctions, antioxidant capacity and related signaling molecules in the gills of young grass carp (Ctenopharyngodon idella). Fish were fed diets that contained 0.12-2.04 mg thiamin kg(-1) for 8 weeks. We found that dietary thiamin deficiency resulted in reduced complement 3 content, lysozyme and acid phosphatase activities, mRNA levels of hepcidin, liver-expressed antimicrobial peptides 2, transforming growth factor (TGF)-β1, interleukin (IL)-10, inhibitor protein-κBα (IκBα), ribosomal S6 protein kinase 1 and target of rapamycin (TOR) and increased expression of interferon-γ2, tumor necrosis factor-α, TGF-β2, IL-1β, IL-8, IκB kinases (IKKβ and IKKγ) and nuclear factor-κB p65 (NF-κB p65). Our findings showed that thiamin deficiency reduced the immune status of fish gills. Furthermore, thiamin deficiency resulted in reduced mRNA transcript levels of claudin b, claudin 3, claudin 12, zonula occludens 1 (ZO-1) and occludin and increased mRNA transcript levels of claudin 15a, myosin light-chain kinase (MLCK) and p38 mitogen-activated protein kinase (p38 MAPK) in fish gill tissues. These data suggested that thiamin deficiency disrupted tight junction-mediated fish gill barrier function. Additionally, reactive oxygen species, malondialdehyde and protein carbonyl levels and both the activities and expression levels of Cu/Zn superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferases and glutathione reductase, as well as NF-E2-related factor 2 gene expression in fish gills, were lower in fish fed a thiamin-deficient diet. By contrast, thiamin deficiency increased levels of Kelch-like-ECH-associated protein 1a (Keap1a) and Keap1b mRNA transcript expression in fish gills. Taken together, our findings indicated that thiamin deficiency impaired fish gill health by effects on the expression of genes encoding cytokines, tight junction proteins, antioxidant enzymes, NF-κB p65, MLCK and Nrf2.
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; Xianning Agriculture Academy of Sciences, Xianning 437100, China.
authors.forename: Ling-Mei
authors.initials: LM
authors.lastname: Wen
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Wei-Dan
authors.initials: WD
authors.lastname: Jiang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Pei
authors.initials: P
authors.lastname: Wu
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu 610066, China.
authors.forename: Sheng-Yao
authors.initials: SY
authors.lastname: Kuang
authors.affiliation: Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu 610066, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Tang
authors.affiliation: Animal Nutrition Institute, Sichuan Academy of Animal Science, Chengdu 610066, China.
authors.forename: Wu-Neng
authors.initials: WN
authors.lastname: Tang
authors.affiliation: Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Yong-An
authors.initials: YA
authors.lastname: Zhang
authors.affiliation: Animal Nutrition Institute, Sichuan Agricultural University, Chengdu 611130, China; Fish Nutrition and Safety Production University Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China; Key Laboratory for Animal Disease-Resistance Nutrition of China Ministry of Education, Sichuan Agricultural University, Chengdu 611130, China. Electronic address: xqzhouqq@tom.com.
authors.forename: Xiao-Qiu
authors.initials: XQ
authors.lastname: Zhou
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D002347:Carps / Q000276:immunology*; D002374:Catalase / Q000235:genetics; D003176:Complement C3 / Q000378:metabolism; D016207:Cytokines / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics; D005880:Gills / Q000276:immunology* / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000235:genetics; D005980:Glutathione Reductase / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics; D000072019:Kelch-Like ECH-Associated Protein 1 / Q000235:genetics; D009113:Muramidase / Q000378:metabolism; D009219:Myosin-Light-Chain Kinase / Q000235:genetics; D051267:NF-E2-Related Factor 2 / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics; D058570:TOR Serine-Threonine Kinases / Q000235:genetics; D013832:Thiamine Deficiency / Q000276:immunology* / Q000662:veterinary*; D062725:Tight Junction Proteins / Q000235:genetics; D051996:Transcription Factor RelA / Q000235:genetics; D016212:Transforming Growth Factor beta / Q000235:genetics; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics
chemical_list: D003176:Complement C3; D016207:Cytokines; D029941:Fish Proteins; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; D012333:RNA, Messenger; D062725:Tight Junction Proteins; D051996:Transcription Factor RelA; D016212:Transforming Growth Factor beta; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D058570:TOR Serine-Threonine Kinases; D009219:Myosin-Light-Chain Kinase; D048051:p38 Mitogen-Activated Protein Kinases; D000135:Acid Phosphatase; D009113:Muramidase
keywords: Antioxidant capacity; Gill; Immune response; Thiamin deficiency; Tight junction