Vitamin E deficiency depressed fish growth, disease resistance, and the immunity and structural integrity of immune organs in grass carp (Ctenopharyngodon idella): Referring to NF-κB, TOR and Nrf2 signaling.

Abstract

This study investigated the effects of dietary vitamin E on growth, disease resistance and the immunity and structural integrity of head kidney, spleen and skin in grass carp (Ctenopharyngodon idella). The fish were fed six diets containing graded levels of vitamin E (0, 45, 90, 135, 180 and 225 mg/kg diet) for 10 weeks. Subsequently, a challenge test was conducted by injection of Aeromonas hydrophila. The results showed that compared with optimal vitamin E supplementation, vitamin E deficiency caused depressed growth, poor survival rates and increased skin lesion morbidity in grass carp. Meanwhile, vitamin E deficiency decreased lysozyme and acid phosphatase activities, complement component 3 and complement component 4 contents in the head kidney, spleen and skin of grass carp (P < 0.05). Moreover, vitamin E deficiency down-regulated antimicrobial peptides (Hepcidin, liver-expressed antimicrobial peptide-2A, -2B, β-defensin), IL-10, TGFβ1, IκBα, TOR and S6K1 mRNA levels (P < 0.05) and up-regulated IL-1β, IL-6, IL-8, IFN-γ2 and TNFα, NF-κB p65, IKKα, IKKβ and 4EBP1 (not in the head kidney) mRNA levels (P < 0.05). In addition, vitamin E deficiency caused oxidative damage, decreased superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and glutathione reductase (GR) activities, and down-regulated the mRNA levels of antioxidant enzymes and signaling molecules Nrf2 (P < 0.05). Vitamin E deficiency also induced apoptosis by up-regulating capase-2, -3, -7, and -8 mRNA levels in the head kidney, spleen and skin of grass carp. In conclusion, this study indicated that dietary vitamin E deficiency depressed fish growth, impaired the immune function and disturbed the structural integrity of the head kidney, spleen and skin in grass carp, but optimal vitamin E supplementation can reverse those negative effects in fish. The optimal vitamin E requirements for young grass carp (266.39-1026.63 g) to achieve optimal growth performance and disease resistance based on the percent weight gain (PWG) and skin lesion morbidity were estimated to be 116.2 and 130.9 mg/kg diet, respectively. Meanwhile, based on immune indicator (LA activity in the head kidney) and antioxidant indicator (protection of spleen against MDA), the optimal vitamin E requirements for young grass carp were estimated to be 123.8 and 136.4 mg/kg diet, respectively.

• Authors: Jia-Hong Pan, Lin Feng, Wei-Dan Jiang, Pei Wu, Sheng-Yao Kuang, Ling Tang, Yong-An Zhang, Xiao-Qiu Zhou, Yang Liu
• Journal: Fish & shellfish immunology (Fish Shellfish Immunol) Vol. 60 Pg. 219-236 (Jan 2017) ISSN: 1095-9947 [Electronic] England
• PMID: 27888132 (Publication Type: Journal Article)
• Copyright: Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical References

• Fish Proteins
• Vitamin E

Topics

• Aeromonas hydrophila (physiology)
• Animal Feed (analysis)
• Animals
• Carps (growth & development, immunology)
• Diet (veterinary)
• Dietary Supplements
• Disease Resistance (immunology)
• Fish Diseases (immunology, microbiology)
• Fish Proteins (genetics, metabolism)
• Gram-Negative Bacterial Infections (immunology, microbiology, veterinary)
• Head Kidney (immunology)
• Immunity, Innate (immunology)
• Signal Transduction (immunology)
• Skin (immunology)
• Spleen (immunology)
• Vitamin E (immunology)
• Vitamin E Deficiency (physiopathology, veterinary)