Dietary myo-inositol deficiency decreased intestinal immune function related to NF-κB and TOR signaling in the intestine of young grass carp (Ctenopharyngodon idella).

Abstract

In this study, we investigated the effects of dietary myo-inositol on the intestinal immune barrier function and related signaling pathway in young grass carp (Ctenopharyngodon idella). A total of 540 young grass carp (221.33 ± 0.84 g) were fed six diets containing graded levels of myo-inositol (27.0, 137.9, 286.8, 438.6, 587.7 and 737.3 mg/kg) for 10 weeks. After the growth trial, fish were challenged with Aeromonas hydrophila. The results indicated that compared with the optimal dietary myo-inositol level, myo-inositol deficiency (27.0 mg/kg diet): (1) decreased lysozyme (LZ) and acid phosphatase (ACP) activities, as well as complement 3 (C3), C4 and immunoglobulin M (IgM) contents in the proximal intestine (PI), middle intestine (MI) and distal intestine (DI) of young grass carp (P < 0.05). (2) down-regulated the mRNA levels of anti-microbial substance: liver expressed antimicrobial peptide (LEAP) 2A, LEAP-2B, hepcidin, β-defensin-1 and mucin2 in the PI, MI and DI of young grass carp (P < 0.05). (3) up-regulated pro-inflammatory cytokines [IL-1β (not in DI), TNF-α and IL-8], nuclear factor kappa B P65 (not NF-κB P52), c-Rel, IκB kinaseα (IKKα), IKKβ and IKKγ mRNA levels in the PI, MI and DI of young grass carp (P < 0.05); and down-regulated pro-inflammatory cytokines IL-15 (not in DI) and inhibitor of κBα (IκBα) mRNA levels (P < 0.05). (4) down-regulated the mRNA levels of anti-inflammatory cytokines [IL-10 (not in DI), IL-11, IL-4/13B (not IL-4/13A), TGF-β1 and TGF-β2], target of rapamycin (TOR), eIF4E-binding proteins 1 (4E-BP1) and ribosomal protein S6 kinase 1 (S6k1) in the PI, MI and DI of young grass carp (P < 0.05). All data indicated that myo-inositol deficiency could decrease fish intestine immunity and cause inflammation under infection of A. hydrophila. Finally, the optimal dietary myo-inositol levels for the ACP and LZ activities in the DI were estimated to be 415.1 and 296.9 mg/kg diet, respectively.

• Authors: Shuang-An Li, Wei-Dan Jiang, Lin Feng, Yang Liu, Pei Wu, Jun Jiang, Sheng-Yao Kuang, Ling Tang, Wu-Neng Tang, Yong-An Zhang, Juan Yang, Xu Tang, He-Qun Shi, Xiao-Qiu Zhou
• Journal: Fish & shellfish immunology (Fish Shellfish Immunol) Vol. 76 Pg. 333-346 (May 2018) ISSN: 1095-9947 [Electronic] England
• PMID: 29544771 (Publication Type: Journal Article)
• Copyright: Copyright © 2018 Elsevier Ltd. All rights reserved.

Chemical References

• NF-kappa B
• Vitamin B Complex
• Inositol
• TOR Serine-Threonine Kinases

Topics

• Animal Feed (analysis)
• Animals
• Carps (genetics, immunology)
• Diet (veterinary)
• Dietary Supplements (analysis)
• Inositol (deficiency)
• Intestines (immunology)
• NF-kappa B (metabolism)
• Signal Transduction (immunology)
• TOR Serine-Threonine Kinases (metabolism)
• Vitamin B Complex (analysis)