title: Threonine modulates immune response, antioxidant status and gene expressions of antioxidant enzymes and antioxidant-immune-cytokine-related signaling molecules in juvenile blunt snout bream (Megalobrama amblycephala).
abstract: A 9-week feeding trial was conducted to investigate the effects of graded dietary threonine (Thr) levels (0.58-2.58%) on the hematological parameters, immune response, antioxidant status and hepatopancreatic gene expression of antioxidant enzymes and antioxidant-immune-cytokine-related signaling molecules in juvenile blunt snout bream. For this purpose, 3 tanks were randomly arranged and assigned to each experimental diet. Fish were fed with their respective diet to apparent satiation 4 times daily. The results indicated that white blood cell, red blood cell and haemoglobin significantly responded to graded dietary Thr levels, while hematocrit didn't. Complement components (C3 and C4), total iron-binding capacity (TIBC), immunoglobulin M (IgM), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) increased with increasing dietary Thr levels up to 1.58-2.08% and thereafter tended to decrease. Dietary Thr regulated the gene expressions of Cu/Zn-SOD, Mn-SOD and CAT, GPx1, glutathione S-transferase mu (GST), nuclear factor erythroid 2-related factor 2 (Nrf2), heat shock protein-70 (Hsp70), tumor necrosis factor-alpha (TNF-α), apolipoprotein A-I (ApoA1), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and fructose-bisphosphate aldolase B (ALDOB); while the gene expression of peroxiredoxin II (PrxII) was not significantly modified by graded Thr levels. These genes are involved in different functions including antioxidant, immune, and defense responses, energy metabolism and protein synthesis. Therefore, this study could provide a new molecular tool for studies in fish immunonutrition and shed light on the regulatory mechanisms that dietary Thr improved the antioxidant and immune capacities of fish.
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China; Ministry of Marine Resources the State of Eritrea, P.O.Box: 27, Massawa, Eritrea. Electronic address: mike2692011@gmail.com.
authors.forename: Habte-Michael
authors.initials: HM
authors.lastname: Habte-Tsion
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China; Key Laboratory for Genetic Breeding of Aquatic Animals and Aquaculture Biology, Freshwater Fisheries Research Center (FFRC), Chinese Academy of Fishery Sciences (CAFS), Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China.
authors.forename: Mingchun
authors.initials: M
authors.lastname: Ren
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China; Key Laboratory for Genetic Breeding of Aquatic Animals and Aquaculture Biology, Freshwater Fisheries Research Center (FFRC), Chinese Academy of Fishery Sciences (CAFS), Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China.
authors.forename: Bo
authors.initials: B
authors.lastname: Liu
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China; Key Laboratory for Genetic Breeding of Aquatic Animals and Aquaculture Biology, Freshwater Fisheries Research Center (FFRC), Chinese Academy of Fishery Sciences (CAFS), Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China. Electronic address: gexp@ffrc.cn.
authors.forename: Xianping
authors.initials: X
authors.lastname: Ge
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China; Key Laboratory for Genetic Breeding of Aquatic Animals and Aquaculture Biology, Freshwater Fisheries Research Center (FFRC), Chinese Academy of Fishery Sciences (CAFS), Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xie
authors.affiliation: Key Laboratory for Genetic Breeding of Aquatic Animals and Aquaculture Biology, Freshwater Fisheries Research Center (FFRC), Chinese Academy of Fishery Sciences (CAFS), Shanshui East Road No. 9, Wuxi, Jiangsu, 214081, PR China.
authors.forename: Ruli
authors.initials: R
authors.lastname: Chen
mesh_terms: D000818:Animals; D016632:Apolipoprotein A-I / Q000235:genetics; D002374:Catalase / Q000235:genetics; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D003530:Cyprinidae / Q000097:blood / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D016207:Cytokines; D004032:Diet; D004906:Erythrocyte Count; D029941:Fish Proteins / Q000097:blood / Q000235:genetics; D005634:Fructose-Bisphosphate Aldolase / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000235:genetics; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D043143:Hepatopancreas / Q000187:drug effects / Q000378:metabolism; D007075:Immunoglobulin M / Q000097:blood; D007958:Leukocyte Count; D051267:NF-E2-Related Factor 2 / Q000235:genetics; D054464:Peroxiredoxins / Q000235:genetics; D015398:Signal Transduction; D013482:Superoxide Dismutase / Q000235:genetics; D013912:Threonine / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
chemical_list: D016632:Apolipoprotein A-I; D003176:Complement C3; D003181:Complement C4; D016207:Cytokines; D029941:Fish Proteins; D018840:HSP70 Heat-Shock Proteins; D007075:Immunoglobulin M; D051267:NF-E2-Related Factor 2; D014409:Tumor Necrosis Factor-alpha; D013912:Threonine; D054464:Peroxiredoxins; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005634:Fructose-Bisphosphate Aldolase
keywords: Antioxidant capacity; Antioxidant-immune-cytokine-related signaling molecule; Blunt snout bream (Megalobrama amblycephala); Immune response; Threonine