title: Glutamate ameliorates copper-induced oxidative injury by regulating antioxidant defences in fish intestine.
abstract: The objective of this study was to determine the protective effect of glutamate (Glu) in Cu-induced oxidative injury in fish intestine in vivo and enterocytes in vitro. The results indicated that exposure to 6 mg/l Cu for 72 h induced the production of reactive oxygen species, thereby increasing protein oxidation and lipid peroxidation in enterocytes of grass carp in vitro. Cells exposed to Cu alone resulted in a significant increase in lactate dehydrogenase release, which is accompanied by depletions of antioxidants, including total superoxide dismutase (T-SOD), glutathione S-transferase (GST), glutathione reductase (GR), anti-superoxide anion (ASA), anti-hydroxy radical (AHR) activities and GSH content. Pre-treatment with Glu remarkably prevented the toxic effects of Cu on the T-SOD, GST, GR, AHR, and ASA activities and GSH content in enterocytes. However, Cu induced an adaptive increase in the activities of catalase and glutathione peroxidase (GPx). Glu supplementation further increased GPx activity in enterocytes. Interestingly, the experiment in vivo showed that Glu pre-supplementation significantly elevated SOD, GPx, GST, GR, ASA and AHR activities, as well as GSH content. Further results showed that pre-treatment with Glu could alleviate Cu-induced oxidative injury by elevating antioxidant enzyme activities through regulating the expression of NF-E2-related nuclear factor 2 (Nrf2) mRNA. Together, these results indicated that Glu could attenuate Cu-induced cellular oxidative damage in fish intestine, likely mediated through Nrf2 signalling pathways regulating mRNA expressions of antioxidant enzyme genes and synthesis of GSH.
authors.affiliation: 1College of Animal Science and Technology,Sichuan Agricultural University,Chengdu 611130,People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.affiliation: 1College of Animal Science and Technology,Sichuan Agricultural University,Chengdu 611130,People's Republic of China.
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Wu
authors.affiliation: 2Animal Nutrition Institute,Sichuan Agricultural University,Chengdu 611130,People's Republic of China.
authors.forename: Xiao-Qiu
authors.initials: XQ
authors.lastname: Zhou
authors.affiliation: 2Animal Nutrition Institute,Sichuan Agricultural University,Chengdu 611130,People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
authors.affiliation: 2Animal Nutrition Institute,Sichuan Agricultural University,Chengdu 611130,People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: 2Animal Nutrition Institute,Sichuan Agricultural University,Chengdu 611130,People's Republic of China.
authors.forename: Wei-Dan
authors.initials: WD
authors.lastname: Jiang
authors.affiliation: 2Animal Nutrition Institute,Sichuan Agricultural University,Chengdu 611130,People's Republic of China.
authors.forename: Pei
authors.initials: P
authors.lastname: Wu
authors.affiliation: 1College of Animal Science and Technology,Sichuan Agricultural University,Chengdu 611130,People's Republic of China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002347:Carps; D003300:Copper / Q000633:toxicity*; D004032:Diet / Q000662:veterinary; D005393:Fish Diseases / Q000139:chemically induced*; D005786:Gene Expression Regulation / Q000187:drug effects; D018698:Glutamic Acid / Q000494:pharmacology*; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D000975:Antioxidants; D051267:NF-E2-Related Factor 2; D012333:RNA, Messenger; D018698:Glutamic Acid; D003300:Copper
keywords: 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium; AHR anti-hydroxy radical; AKP alkaline phosphatase; ASA anti-superoxide anion; Antioxidants; CAT catalase; Copper; DMEM Dulbecco’s Modified Eagle’s Medium; GPx glutathione peroxidase; GR glutathione reductase; GST glutathione S-transferase; Glu glutamate; Glutamate; Intestine; LDH lactate dehydrogenase; MDA malondialdehyde; MTS 3-(4; NF-E2-related nuclear factor 2; Nrf2 NF-E2-related nuclear factor 2; OD optical density; Oxidative injury; PC protein carbonyl; ROS reactive oxygen species; SOD superoxide dismutase