Dietary choline modulates immune responses, and gene expressions of TOR and eIF4E-binding protein2 in immune organs of juvenile Jian carp (Cyprinus carpio var. Jian)

Assessing haematological parameters and probable toxicity analysis in two coastal fish species at harbouring areas of Digha coastal belt, West Bengal, India

Coastal ecosystems are vital for maintaining the biodiversity and human livelihoods, but they are increasingly subjected to anthropogenic pressures, including pollution from various sources. Present work intends to assess the possible threats in coastal ecosystem as well as coastal fish species, in particular, through haematological parameters caused due to exposure of environmental contaminants like polycyclic aromatic hydrocarbons (PAHs), potentially toxic metals (PTMs), etc. This study analysed the haematological parameters and probable toxicity levels in two important coastal fish species, viz., Mystus sp. and Mugil sp. widely available in Digha coastal belt. Different haematological parameters, such as WBCs (White Blood Cells), Lym (Lymphocytes), Gran (Granulocytes), Mid (Monocytes), RBCs (Red Blood Cells), HCT (Haematocrit) value, MCV (Mean Corpuscular Volume), MCH (Mean Corpuscular Haemoglobin), MCHC (Mean Corpuscular Haemoglobin Concentration), RDW- CV (Red Cells Distribution Width-Co-efficient of Variation), RDW- SD (Red Cells Distribution Width-Standard Deviation), PLT (Total Platelet Count), MPV (Mean Platelet Volume), PDW- SD (Platelet Distribution Width-Standard Deviation), PDW- CV (Platelet Distribution Width-Co-efficient of Variation), PCT (Plateletcrit), PLCR (Platelet Large Cell Ratio), PLCC (Platelet Large Cell Count) and many others were measured directly through Erba H360 Haematology Analyser, simultaneously air dried blood smear was stained by Haematoxylin-Eosin(H-E) and Giemsa stain for assessing morphometric alterations of RBCs, WBCs, platelets as well as to determine the differential counts of WBCs by observing through Leica DM2000 microscope. Evidence of several abnormalities in the erythrocyte's nucleus (ENAs) and the abundance of abnormal celled erythrocytes (ECAs), carcinoma (lymphoproliferative disorder, polycythaemia vera, Hodgkin lymphoma and non-Hodgkin lymphoma), elevation of WBCs content, Lym %(Lymphocyte percentage), Eo(Eosinophils), monocytes, HCT and gross depletion of Ne(Neutrophils), basophils, and PLCR levels indicated a sign of major impact of contamination to two intoxicated fishes which may also affect the human being through food chain and may result into leukaemia in mammalian species, finally. However, comprehensive evaluation of the long-term impacts of the contaminants like PAHs and/or PTMs, etc., on fish populations, human health risk and coastal ecosystem is required to be addressed.

Postruminal choline supply during negative nutrient balance alters components of hepatic mTOR signaling and plasma amino acids in lactating Holstein cows

Choline requirements for dairy cattle are unknown. However, enhanced postruminal supply of choline may increase flux through the methionine cycle to spare Met for other functions such as protein synthesis and phosphatidylcholine (PC) synthesis during periods of negative nutrient balance (NNB). The objective was to investigate the effects of postruminal choline supply during a feed restriction-induced NNB on hepatic abundance and phosphorylation of mTOR (mechanistic target of rapamycin)-related signaling proteins, hepatic lipidome and plasma AA. Ten primiparous rumen-cannulated Holstein cows (158 ± 24 DIM) were used in a replicated 5 × 5 Latin square design with 4 d of treatment and 10 d of recovery (14 d/period). Treatments were unrestricted intake with abomasal infusion of water, restricted intake (R; 60% of net energy for lactation requirements to induce NNB) with abomasal infusion of water (R0) or restriction plus abomasal infusion of 6.25, 12.5, or 25 g/d choline ion. Liver tissue was collected via biopsy on d 5 after infusions ended and used for Western blot analysis to measure proteins involved in mTOR signaling and untargeted lipidomics. Blood was collected on d 1 to 5 for plasma AA analysis. Statistical contrasts for protein and AA data were A0 versus R0 (CONT1), R0 versus the average of choline dose (CONT2) and tests of linear and quadratic effects of choline dose. Analysis of lipidomic data were performed with the web-based metabolomic processing tool MetaboAnalyst 5.0. Ratios of p-RPS6KB1:tRPS6KB1, p-EEF2:tEEF2, and p-EIF2:tEIF2 were greater with R (CONT1). Among those, supply of choline led to decreases in p-EEF2:tEEF2 (CONT2), p-EIF2:tEIF2 and tended to decrease p-EIF4BP1:tEIF4BP1. However, the effect was quadratic only for p-EEF2:tEEF2 and p-EIF2A:tEIF2A, reaching a nadir at 6.25 to 12.5 g/d choline ion. The ratio of p-RPS6KB1:tRPS6KB1 was not affected by supply of choline and was close to 2-fold greater at 25 g/d choline versus A0. Plasma Met concentration decreased with R (CONT1), but increased linearly with choline. Restriction also increased plasma 3-methyl-histidine (CONT1). The partial least squares discriminant analysis model of liver lipids distinguished treatments, with 13.4% of lipids being modified by treatment. One-way ANOVA identified 109 lipids with a false discovery rate ≤0.05. The largest group identified was PC species; all 35 detected decreased with R versus A0, but there were few differences among choline treatments. Overall, data suggested that dephosphorylation of EEF2 and EIF2A due to enhanced choline supply potentially helped maintain or increase protein synthesis during NNB. While activation of mTOR was not altered by choline, this idea of increased protein synthesis is partly supported by the increased circulating Met. However, enhanced postruminal choline had limited effects on the species of lipid produced during a period of NNB.

Effects of choline supplementation on growth performance, liver histology, nonspecific immunity and related genes expression of hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatu) fed with high-lipid diets

This study was conducted to evaluate the effect of dietary choline levels on growth performance, liver histology, nonspecific immunity and related gene expression of hybrid grouper (♀ Epinephelus fuscoguttatus × ♂ E. lanceolatus) fed with high-lipid diets. The fish (initial body weight 6.86 ± 0.01 g) were fed diets containing different choline levels (0, 5, 10, 15, and 20 g/kg, named D1, D2, D3, D4, and D5, respectively) for 8 weeks. The results showed that:(1) dietary choline levels had no significant effect on final body weight (FBW), feed conversion rate (FCR), visceral somatic index(VSI) and condition factor (CF) compared with the control group (P > 0.05). However, the hepato somatic index (HSI) in the D2 group was significantly lower than that in the control group and the survival rate (SR) in the D5 group was significantly lower (P < 0.05). (2) with dietary choline level increasing, alkaline phosphatase (AKP) and superoxide dismutase (SOD) of serum showed a tendency to increase and then decrease, and the maximum values were obtained in the D3 group, but the contents of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) decreased significantly (P < 0.05). (3) Immunoglobulin M (IgM), lysozyme (LYZ), catalase (CAT), total antioxidative capacity (T-AOC), and SOD in the liver all showed a trend of first increase and then decrease with the dietary choline level increased, and all of them achieved the maximum value at D4 group (P < 0.05), while reactive oxygen species (ROS) and malondialdehyde (MDA) in the liver decreased significantly (P < 0.05). (4) results from liver sections suggest that appropriate levels of choline can improve cell structure, compared with the control group, the damaged histological morphology of the liver was relieved and even returned to normal in D3 group. (5) in the D3 group, choline significantly upregulated the expression of hepatic sod and cat mRNA, whereas the expression of cat in the D5 group was significantly lower than that in the control group (P < 0.05); And the supply of choline stimulated a significant down-regulation of interleukin 6 (il6), myeloid differentiation factor 8 (myd88), toll-like receptor 22 (tlr22) mRNA expression levels in liver, while the expression of cellular tumor antigen p53 (p53) and interleukin 10 (il10) showed an upward and then downward trend (P < 0.05). In general, choline can improve the immunity of hybrid grouper by regulating non-specific immune-related enzyme activity and gene expression and reducing oxidative stress induced by high-lipid diet.

Aflatoxin B1 damaged structural barrier through Keap1a/Nrf2/ MLCK signaling pathways and immune barrier through NF-κB/ TOR signaling pathways in gill of grass carp (Ctenopharyngodon idella)

Aquafeeds are susceptible to contamination caused by aflatoxin B1 (AFB1). The gill of fish is an important respiratory organ. However, few studies have investigated the effects of dietary AFB1 exposure on gill. This study aimed to discuss the effects of AFB1 on the structural and immune barrier of grass carp gill. Dietary AFB1 increased reactive oxygen species (ROS) levels, protein carbonyl (PC) and malondialdehyde (MDA) contents, which consequently caused oxidative damage. In contrast, dietary AFB1 decreased antioxidant enzymes activities, relative genes expression (except MnSOD) and the contents of glutathione (GSH) (P < 0.05), which are partly regulated by NF-E2-related factor 2 (Nrf2/Keap1a). Moreover, dietary AFB1 caused DNA fragmentation. The relative genes of apoptosis (except Bcl-2, McL-1 and IAP) were significantly upregulated (P < 0.05), and apoptosis was likely upregulated through p38 mitogen-activated protein kinase (p38MAPK). The relative expressions of genes associated with tight junction complexes (TJs) (except ZO-1 and claudin-12) were significantly decreased (P < 0.05), and TJs were likely regulated by myosin light chain kinase (MLCK). Overall, dietary AFB1 disrupted the structural barrier of gill. Furthermore, AFB1 increased gill sensitivity to F. columnare, increased Columnaris disease and decreased the production of antimicrobial substances (P < 0.05) in grass carp gill, and upregulated the expression of genes involved with pro-inflammatory factors (except TNF-α and IL-8) and the pro-inflammatory response partly attributed to the regulation by nuclear factor κB (NF-κB). Meanwhile, the anti-inflammatory factors were downregulated (P < 0.05) in grass carp gill after challenge with F. columnare, which was partly attributed to the target of rapamycin (TOR). These results suggested that AFB1 aggravated the disruption of the immune barrier of grass carp gill after being challenge with F. columnare. Finally, the upper limit of safety of AFB1 for grass carp, based on Columnaris disease, was 31.10 μg/kg diet.

Dietary choline promotes growth, antioxidant capacity and immune response by modulating p38MAPK/p53 signaling pathways of juvenile Pacific white shrimp (Litopenaeus vannamei)

The objective of the present study was to evaluate the effects of dietary choline levels on growth performance, antioxidant capacity, innate immunity and hemocyte apoptosis of Litopenaeus vannamei. Six isonitrogenous and isolipidic diets were formulated to contain different choline levels: 2.91 (basal diet), 3.85, 4.67, 6.55, 10.70 and 18.90 g kg^-1choline, respectively. The results indicated that shrimp fed diet with 4.67 g kg^-1 choline had the highest final body weight (FBW), percent weight gain (PWG), specific growth rate (SGR), feed efficiency (FE), and activities of alkaline phosphatase (AKP) and phenoloxidase (PO) in hemolymph among all treatments. Shrimp fed diet with 18.90 g kg^-1 choline exhibited significantly lower crude lipid in hepatopancreas than those fed diets with 2.91, 3.85, 4.67 and 6.55 g kg^-1 choline (P < 0.05). The concentration of reactive oxygen species (ROS) and apoptosis rate in hemocytes significantly decreased with the increase of dietary choline levels (P < 0.05). Shrimp fed diets with 6.55, 10.70 and 18.90 g kg^-1 choline had significantly higher scavenging ability of hydroxyl radical (SAHR) and total antioxidant capacity (T-AOC) in hemolymph than those fed diet with 2.91 g kg^-1 choline (P < 0.05). Dietary choline supplementation down-regulated the expression of genes related to apoptosis such as caspase-1, caspase-3, caspase-8, p53, and p38MAPK in hemocytes (P < 0.05), while up-regulated the expression of anti-apoptosis gene bcl2 in hemocytes (P < 0.05). Overall, the results of the present study demonstrated that appropriate dietary choline could improve growth performance and feed utilization, enhance antioxidant capacity and innate immunity, and mitigate apoptosis in Litopenaeus vannamei. Moreover, the inhibition of hemocyte apoptosis by dietary choline may be regulated by the p38MAPK-p53 signaling pathway.

Choline Chloride Induces Growth Performance of Indian Major Carps and Air-Breathing Fish Species with an Outcome of Quality Food-Fish under a Semi-Intensive Culture System: A Biochemical Investigation

The present study was intended to determine the possible influences of direct field application of choline chloride into pond water in addition to farm-made-aqua-feed under a semi-intensive culture system on the growth and biochemical parameters of two Indian major carps (IMCs), Catla catla (Catla) and Labeo rohita (Rahu), and two air-breathing species, Clarias batrachus (Magur) and Anabas testudineus (Koi), cultured in a ratio of 2:5:1:1 (Catla/Rahu/Magur/Koi) in three experimental ponds for a period of 90 days during the breeding season (June to August). Results were compared with control (C: fed only with farm-made-aqua-feed) and treatment (T: P1 and P2: farm-made-aqua-feed plus choline chloride into pond water directly at the rate of 350 g bigha^-1 fortnightly or 350 g per 1600 square meter fortnightly). A significant increasing trend was observed in the growth parameters including total length-final (TLF), standard length-final (SLF), mean weight-final (MWF), % gain of mean total length (MTL), % gain of mean standard length (MSL), % weight gain (WG), specific growth rate (SGR) % per day, and survivability %. However, a reverse pattern was noticed in the food conversion ratio (FCR) both in IMCs and air-breathing fish species under choline supplementation. Serum biochemical responses, e.g., total protein (PRO), lactate dehydrogenase (LDH), glucose (GLU), and calcium (Ca) showed significant enhancement, and alkaline phosphatase (ALP), alanine amino transaminase (ALT), aspartate amino transaminase (AST), cholesterol (CHOLES), and triglycerides (Trig) showed gradual significant reduction during the breeding season under choline exposure. Treated fishes showed prevention from liver dysfunction and fatty liver formation, and increased body crude protein content. Results indicated favorable growth and yield, which may benefit fish farmers during their culture practices, and the output fish species under choline supplementation resulted in quality food-fish for human consumption.

Short-term exposure to polymethylmethacrylate nanoplastics alters muscle antioxidant response, development and growth in Sparus aurata

Polymethylmethacrylate (PMMA) plastic fragments have been found abundant in the environment, but the knowledge regarding its effects on the physiology of aquatic animals is still poorly studied. Here the short-term (96 h) effects of waterborne exposure to PMMA nanoplastics (PMMA-NPs) on the muscle of gilthead sea bream (Sparus aurata) fingerlings was evaluated at a concentration range that includes 0.001 up to 10 mg/L. The expression of key transcripts related to cell stress, tissue repair, immune response, antioxidant status and muscle development, together with several biochemical endpoints and metabolic parameters. Results indicate that exposure to PMMA-NPs elicit mildly antioxidant responses, enhanced the acetylcholinesterase (AChE) activity, and inhibited key regulators of muscle development (growth hormone receptors ghr-1/ghr-2 and myostatin, mstn-1 transcripts). However, no effects on pro-inflammatory cytokines (interleukin 1β, il1β and tumor necrosis factor α, tnfα) expression nor on the levels of energetic substrates (glucose, triglycerides and cholesterol) were found.

Multifaceted role of one-carbon metabolism on immunometabolic control and growth during pregnancy, lactation and the neonatal period in dairy cattle

Dairy cattle undergo dramatic metabolic, endocrine, physiologic and immune changes during the peripartal period largely due to combined increases in energy requirements for fetal growth and development, milk production, and decreased dry matter intake. The negative nutrient balance that develops results in body fat mobilization, subsequently leading to triacylglycerol (TAG) accumulation in the liver along with reductions in liver function, immune dysfunction and a state of inflammation and oxidative stress. Mobilization of muscle and gluconeogenesis are also enhanced, while intake of vitamins and minerals is decreased, contributing to metabolic and immune dysfunction and oxidative stress. Enhancing post-ruminal supply of methyl donors is one approach that may improve immunometabolism and production synergistically in peripartal cows. At the cellular level, methyl donors (e.g. methionine, choline, betaine and folic acid) interact through one-carbon metabolism to modulate metabolism, immune responses and epigenetic events. By modulating those pathways, methyl donors may help increase the export of very low-density lipoproteins to reduce liver TAG and contribute to antioxidant synthesis to alleviate oxidative stress. Thus, altering one-carbon metabolism through methyl donor supplementation is a viable option to modulate immunometabolism during the peripartal period. This review explores available data on the regulation of one-carbon metabolism pathways in dairy cows in the context of enzyme regulation, cellular sensors and signaling mechanisms that might respond to increased dietary supply of specific methyl donors. Effects of methyl donors beyond the one-carbon metabolism pathways, including production performance, immune cell function, mechanistic target or rapamycin signaling, and fatty acid oxidation will also be highlighted. Furthermore, the effects of body condition and feeding system (total mixed ration vs. pasture) on one-carbon metabolism pathways are explored. Potential effects of methyl donor supply during the pepartum period on dairy calf growth and development also are discussed. Lastly, practical nutritional recommendations related to methyl donor metabolism during the peripartal period are presented. Nutritional management during the peripartal period is a fertile area of research, hence, underscoring the importance for developing a systems understanding of the potential immunometabolic role that dietary methyl donors play during this period to promote health and performance.

Dietary biotin deficiency decreased growth performance and impaired the immune function of the head kidney, spleen and skin in on-growing grass carp (Ctenopharyngodon idella)

The aim of this study was to investigate the effects of dietary biotin deficiency on the growth performance and immune function of the head kidney, spleen and skin in on-growing grass carp (Ctenopharyngodon idella). A total of 540 on-growing grass carp (117.11 ± 0.48 g) were fed six diets containing increasing levels of biotin (0.012, 0.110, 0.214, 0.311, 0.427 and 0.518 mg/kg diet) for 70 days. Subsequently, a challenge experiment was performed by infecting them with Aeromonas hydrophila for six days. Our results showed that compared with the appropriate biotin level, (1) biotin deficiency (0.012 mg/kg diet) reduced the activities of lysozyme (LZ) and acid phosphatase (ACP), decreased the contents of complement 3 (C3), C4 and immunoglobulin M (IgM), as well as reduced the mRNA levels of antimicrobial peptides in the head kidney, spleen and skin of on-growing grass carp; (2) biotin deficiency reduced the mRNA levels of anti-microbial substances: liver-expressed antimicrobial peptide (LEAP) -2A, LEAP-2B, hepcidin, β-defensin-1 and mucin 2 in the head kidney, spleen and skin of on-growing grass carp; (3) biotin deficiency increased the mRNA levels of pro-inflammatory cytokines interleukin 1β (IL-1β), IL-6, IL-8, IL-12p40, IL-15, IL-17D, tumour necrosis factor α (TNF-α) and interferon γ2 (IFN-γ2) partially in association with nuclear factor-kappa B (NF-κB) signalling and reduced anti-inflammatory IL-4/13A, IL-10, IL-11 and transforming growth factor β1 (TGF-β1) mRNA levels partially in association with target of rapamycin (TOR) signalling in the head kidney, spleen and skin of on-growing grass carp. Interestingly, biotin deficiency had no effect on the expression of IL-12p35, IL-4/13B, TGF-β2, 4E-BP1 (skin only) or IKKα in the head kidney, spleen and skin of on-growing grass carp. In conclusion, the results indicated that biotin deficiency impaired the immune function of the head kidney, spleen and skin in fish. Finally, based on the percent weight gain (PWG), the ability to prevent skin haemorrhages and lesions, the LZ activity in the head kidney and the C4 content in the spleen, the optimal dietary biotin levels for on-growing grass carp (117-534 g) were estimated as 0.210, 0.230, 0.245 and 0.238 mg/kg diet, respectively.

The effect of dietary supplementation with Clostridium butyricum on the growth performance, immunity, intestinal microbiota and disease resistance of tilapia (Oreochromis niloticus)

This study was conducted to assess the effects of dietary Clostridium butyricum on the growth, immunity, intestinal microbiota and disease resistance of tilapia (Oreochromis niloticus). Three hundreds of tilapia (56.21 ± 0.81 g) were divided into 5 groups and fed a diet supplemented with C. butyricum at 0, 1 x 10⁴, 1 x 10⁵, 1 x 10⁶ or 1 x 10⁷ CFU g^-1 diet (denoted as CG, CB1, CB2, CB3 and CB4, respectively) for 56 days. Then 45 fish from each group were intraperitoneally injected with Streptococcus agalactiae, and the mortality was recorded for 14 days. The results showed that dietary C. butyricum significantly improved the specific growth rate (SGR) and feed intake in the CB2 group and decreased the cumulative mortality post-challenge with S. agalactiae in the CB2, CB3 and CB4 groups. The serum total antioxidant capacity and intestinal interleukin receptor-associated kinase-4 gene expression were significantly increased, and serum malondialdehyde content and diamine oxidase activity were significantly decreased in the CB1, CB2, CB3 and CB4 groups. Serum complement 3 and complement 4 concentrations and intestinal gene expression of tumour necrosis factor α, interleukin 8, and myeloid differentiation factor 88 were significantly higher in the CB2, CB3 and CB4 groups. Intestinal toll-like receptor 2 gene expression was significantly upregulated in the CB3 and CB4 groups. Dietary C. butyricum increased the diversity of the intestinal microbiota and the relative abundance of beneficial bacteria (such as Bacillus), and decreased the relative abundance of opportunistic pathogenic bacteria (such as Aeromonas) in the CB2 group. These results revealed that dietary C. butyricum at a suitable dose enhanced growth performance, elevated humoral and intestinal immunity, regulated the intestinal microbial components, and improved disease resistance in tilapia. The optimal dose was 1 x 10⁵ CFU g^-1 diet.

Dietary iron deficiency impaired intestinal immune function of on-growing grass carp under the infection of Aeromonas hydrophila: Regulation of NF-κB and TOR signaling

Iron is an important mineral element for fish. In this study, we investigated the influences of dietary iron deficiency on intestinal immune function as well as underlying signaling of on-growing grass carp (Ctenopharyngodon idella). Fish were fed with six graded level of dietary iron for sixty days, and a fourteen days' challenge test under infection of Aeromonas hydrophila thereafter. Results showed that compared with optimal iron level, iron deficiency increased enteritis morbidity, decreased lysozyme (LZ) and acid phosphatase (ACP) activities, complement 3 (C3), C4 and immunoglobulin M (IgM) concentrations and down-regulated mRNA levels of hepcidin, liver expressed antimicrobial peptide 2A (LEAP-2A), LEAP-2B, Mucin2, β-defensin-1, anti-inflammatory cytokines transforming growth factor β1 (TGF-β1), TGF-β2, interleukin 4/13A (IL-4/13A), IL-4/13B, IL-10, IL-11 and IL-15, inhibitor of κBα (IκBα), target of rapamycin (TOR) and ribosomal protein S6 kinase 1 (S6K1), whereas up-regulated mRNA levels of pro-inflammatory cytokines IL-1β, interferon γ2 (IFN-γ2), IL-8, IL-12p35, IL-12p40 and IL-17D, nuclear factor kappa B (NF-κB) p65, IκB kinases α (IKKα), IKKβ and eIF4E-binding protein (4E-BP) in intestine of on-growing grass carp, indicating that iron deficiency impaired intestinal immune function of fish under infection of A. hydrophila. Besides, iron excess also increased enteritis morbidity and impaired immune function of fish under infection of A. hydrophila. In addition, the effect of ferrous fumarate on intestinal immune function of on-growing grass carp is more efficient than ferrous sulfate. Finally, based on ability against enteritis, LZ activities in mid intestine and distal intestine, we recommended adding 83.37, 86.71 and 85.39 mg iron/kg into diet, respectively.

Effects of dietary tryptophan levels on antioxidant status and immunity for juvenile blunt snout bream (Megalobrama amblycephala) involved in Nrf2 and TOR signaling pathway

Dietary administration of tryptophan has been proved improving growth performance of fish. An 8-week feeding trial was conducted to investigate the effects of dietary tryptophan level on antioxidant capacity and immune response through Nrf2 and TOR signaling pathway. The results showed that, 0.08% tryptophan level significantly increased plasma aspartate aminotransferase (AST), while immunoglobulin M (IgM) and alkaline phosphatase (ALP) were strikingly increased by 0.40% level. The level of plasma complement component 3 (C3), alanine aminotransferase (ALT) and albumin (ALB) were independent of tryptophan supplementation. Total superoxide dismutase (T-SOD), catalase (CAT), total antioxidant capacity (T-AOC) and glutathione (GSH) activity were increased with increasing dietary tryptophan level until 0.40% and then decreased, while the level of malondialdehyde (MDA) showed a reverse trend. 0.19% and 0.28% tryptophan level significantly improved the glutathione peroxidase 1 (GPx-1) activity. Compared with 0.08% dietary tryptophan level, 0.40% level significantly improved nuclear factor erythroid 2-related factor 2 (Nrf2), GPx, manganese superoxide dismutase (Mn-SOD), CAT and transforming growth factor-β (TGF-β) mRNA level, while Kelch-like ECH-associated protein 1 (Keap1) and interleukin 1β (IL-1β) mRNA level were significantly decreased. The relative expression of copper zinc superoxide dismutase (Cu/Zn-SOD), heme oxygenase-1 (HO-1), target of rapamycin (TOR), phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K), protein kinase B (Akt) and interleukin 10 (IL-10) were significantly improved by 0.28% diet, while the mRNA level of tumor necrosis factor-α (TNF-α) and nuclear factor-kappa B (NF-κB) were increased by 0.08% diet. Interleukin 8 (IL-8) mRNA level was not significantly affected by dietary tryptophan. Based on MDA and T-SOD value, the optimal dietary tryptophan level of juvenile blunt snout bream was determined to be 0.33% (1.03% of dietary protein) and 0.36% (1.13% of dietary protein), respectively, using quadratic regression analysis.

Dietary conjugated linoleic acid modulates morphology, selective immune parameters, and gene expressions in the intestine of grass carp

Conjugated linoleic acid (CLA) has been shown to exhibit anti-inflammatory properties in the intestine in mammals. However, the effect of CLA on intestinal immune response in fish is still unknown. Therefore, a 65-day growth trial was conducted to investigate the effects of dietary conjugated linoleic acid (CLA) on morphology, selective immune parameters, and gene expressions in the intestine of grass carp. Seven isonitrogenous and isolipidic diets were formulated as follows: 0 (control), 0.5 (CLA0.5), 1 (CLA1), 1.5 (CLA1.5), 2 (CLA2), 2.5 (CLA2.5), and 3 (CLA3) g CLA per 100g of feed. RESULTS: showed that dietary supplementation of 1.5-3% CLA significantly (P < 0.05) increased the fold and enterocyte heights in the PI and MI of grass carp. Complement 3 (C3) and immunoglobulin M (IgM) contents in three intestinal segments were significantly (P < 0.05) higher in fish fed with CLA1.5 to CLA2.5 diets compared to fish fed the control diet. CLA1.5 to CLA2.5 diets significantly (P < 0.05) increased the mRNA expression levels of anti-inflammatory cytokines (IL-10 and TGFβ1) and significantly (P < 0.05) reduced the mRNA expression levels of pro-inflammatory cytokines (IL-1β, IL-8, and TNF-α) in the PI, MI, and DI. This improved expression of anti-inflammatory cytokines and the inhibited expression of pro-inflammatory cytokines in the intestine of grass carp, might be mediated via TLR4/NF-κB-signaling pathway. Our results suggested that CLA1.5 to CLA2 diets improved intestinal morphology, increased the expression of anti-inflammatory cytokines, and inhibited the expression of pro-inflammatory cytokines in the intestine of grass carp. In conclusion, dietary supplementation of 1.5%-2% CLA show the anti-inflammatory therapeutic potential in the intestine of grass carp. The anti-inflammatory therapeutic potential of CLA might be mediated via TLR4/NF-κB-signaling pathway.

Effects of dietary soybean lecithin on growth performance, blood chemistry and immunity in juvenile stellate sturgeon (Acipenser stellatus)

An eleven weeks feeding trial was conducted to determine the effects of different levels of dietary soybean lecithin (SBL) on growth performance, blood chemistry and immunity in juvenile stellate sturgeon (Acipenser stellatus). Fish were fed seven isoproteic (44% crude protein) and isolipidic (17% crude fat) diets containing graded levels of SBL: 0 (control), 1, 2, 4, 6, 8 and 10%. Results showed that dietary SBL supplementation significantly improved the final body weight (BW) and weight gain (WG). Fish fed 6% SBL showed the highest BW and WG values in comparison to fish fed the control diet (P < 0.05), whereas increasing SBL levels above 6% had little practical benefit in terms of somatic growth performance. The inclusion of SBL in diets significantly improved the immune response as data from lysozyme, total Ig levels, alternative complement, phagocytic and bactericidal activities indicated (P < 0.05). The broken-line regression analysis of immunological variable revealed that depending on the parameter considered, the optimal SBL levels in diets for stellate sturgeon juveniles varied. In particular, dietary SBL levels requirements in stellate sturgeon when considering the phagocytic activity rate were determined at 3.3%, whereas 4.1-4.2% were recommended when considering data from lysozyme, alternative complement and bactericidal activities. In contrast, the highest minimum dietary SBL content was estimated at 6.9% when data from total Ig levels were considered. These results indicated that dietary PLs are required for boosting innate immunity in stellate sturgeon, although their minimal level changed depending on the immunological parameter considered. Therefore, we assume that SBL levels comprised between 3.3 and 6.9% may be used as a prophylactic measure to improve the health status in stellate sturgeon. Red blood cell count, hemoglobin and hematocrit levels increased with increasing dietary SBL levels, especially in those sturgeons fed the diet with 6% SBL (P < 0.05). In addition, white blood cell counts significantly increased as dietary SBL levels increased from 4 to 8% in comparison to the control group. Blood biochemistry was also affected by different dietary SBL levels. In particular, significantly higher levels of glucose, cholesterol, HDL and triglycerides were detected in fish fed >6%, >4%, >2% and 2% SBL, respectively (P < 0.05). Based on somatic growth parameters, blood chemistry and systemic immunity parameters, diets containing ca. 6% SBL are recommended for juvenile stellate sturgeon.

Optimal α-lipoic acid strengthen immunity of young grass carp (Ctenopharyngodon idella) by enhancing immune function of head kidney, spleen and skin

This study was for the first time to investigate the effects of α-lipoic acid (LA) on growth and immune function of head kidney, spleen and skin in young grass carp (Ctenopharyngodon idella). A total of 540 healthy grass carp (with initial body weight at 216.59 ± 0.33 g) were randomly divided into six groups and fed six separate diets with graded dietary levels of LA for 70 days. Un-supplemented group did not find LA and its concentrations in the other five diets were 203.25, 403.82, 591.42, 781.25 and 953.18 mg kg^-1, respectively. After the growth trial, fish were challenged with A. hydrophila for 14 days. The results showed that, compared with the un-supplemented group, optimal LA improved lysozyme (LZ) and acid phosphatase (ACP) activities, enhanced complement 3 (C3), C4 and immunoglobulin (Ig) M contents and up-regulated hepcidin, liver expressed antimicrobial peptide (LEAP)-2A, LEAP-2B and β-defensin-1 mRNA levels in the head kidney, spleen and skin of young grass carp; meanwhile, optimal LA up-regulated anti-inflammatory cytokines transforming growth factor (TGF)-β1, TGF-β2, interleukin (IL)-4/13A (not IL-4/13B), IL-10 and IL-11 mRNA levels partly related to target of rapamycin (TOR) signaling and down-regulated pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interferon (IFN)-γ2, IL-1β, IL-6, IL-8, IL-12p40 (not IL-12p35), IL-15 (not in the skin) and IL-17D mRNA levels partially associated with nuclear factor-kappa B (NF-κB) signaling in the head kidney, spleen and skin of young grass carp. Above results indicated that optimal LA enhanced the immune function of head kidney, spleen and skin in fish. Interestingly, excessive LA decreased the growth and impaired the immune function of head kidney, spleen and skin in fish. Finally, on the basis of the percent weight gain (PWG), the ability against skin hemorrhage and lesion, the IgM content in the head kidney and the LZ activity in the spleen, the optimal dietary LA levels were estimated to be 315.37, 382.33, 353.19 and 318.26 mg kg^-1 diet, respectively.

Low or excess levels of dietary cholesterol impaired immunity and aggravated inflammation response in young grass carp (Ctenopharyngodon idella)

The present study explored the effect of cholesterol on the immunity and inflammation response in the immune organs (head kidney, spleen and skin) of young grass carp (Ctenopharyngodon idella) fed graded levels of dietary cholesterol (0.041-1.526%) for 60 days and then infected with Aeromonas hydrophila for 14 days. The results showed that low levels of cholesterol (1) depressed the innate immune components [lysozyme (LZ), acid phosphatase (ACP), complements and antimicrobial peptides] and adaptive immune component [immunoglobulin M (IgM)], (2) up-regulated the mRNA levels of pro-inflammatory cytokines [interleukin 1β (IL-1β), IL-6, IL-8, IL-12p35, IL-12p40, IL-15, IL-17D, tumor necrosis factor α (TNF-α) and interferon γ2 (IFN-γ2)], partly due to the activated nuclear factor kappa B (NF-κB) signalling, and (3) down-regulated the mRNA levels of anti-inflammatory cytokines [IL-4/13B, IL-10, IL-11, transforming growth factor (TGF)-β1 and TGF-β2], partly due to the suppression of target of rapamycin (TOR) signalling in the immune organs of young grass carp. Interestingly, dietary cholesterol had no influences on the IκB kinase α (IKKα) and IL-4/13A mRNA levels in the head kidney, spleen and skin, the IL-1β and IL-12p40 mRNA levels in the spleen and skin, or the β-defensin-1 mRNA level in the skin of young grass carp. Additionally, low levels of cholesterol increased the skin haemorrhage and lesion morbidity. In summary, low levels of cholesterol impaired immunity by depressing the innate and adaptive immune components, and low levels of cholesterol aggravated the inflammation response via up-regulating the expression of pro-inflammatory cytokines as well as down-regulating the expression of anti-inflammatory cytokines partly through the modulation of NF-κB and TOR signalling in the immune organs of fish. Similar to the low level of cholesterol, the excess level of dietary cholesterol impaired immunity and aggravated inflammation response in the immune organs of fish. Finally, based on the percent weight gain (PWG), the ability against skin haemorrhage and lesions as well as the LZ activity in the head kidney and the ACP activity in the spleen, the optimal dietary cholesterol levels for young grass carp were estimated as 0.721, 0.826, 0.802 and 0.772% diet, respectively.

Selenium deficiency impaired immune function of the immune organs in young grass carp (Ctenopharyngodon idella)

This study aimed to investigate the effects of dietary selenium on resistance to skin haemorrhages and lesions and on immune function as well as the underlying mechanisms of those effects in the head kidney, spleen and skin of young grass carp (Ctenopharyngodon idella). A total of 540 healthy grass carp with initial body weight (226.48 ± 0.68 g) were randomly divided into six groups and fed six separate diets with graded dietary levels of selenium (0.025, 0.216, 0.387, 0.579, 0.795 and 1.049 mg/kg diet) for 80 days. After the feeding period, an immunization trial was performed by infection with Aeromonas hydrophila for 14 days. The results showed that, compared with the optimal selenium level, (1) selenium deficiency impaired the production of antibacterial compounds and immunoglobulins and down-regulated the transcript abundances of antimicrobial peptides and selenoproteins; (2) selenium deficiency aggravated inflammatory responses in part by up-regulating pro-inflammatory cytokines and down-regulating anti-inflammatory cytokines mRNA levels, which were partially related to [IKKα, β, γ/IκBα/NF-κB] signalling and [TOR/(S6K1, 4E-BP1)] signalling, respectively. Interestingly, selenium deficiency had no effect on the expression of TGF-β2, IL-4/13B, IL-10, IL-12p35, IL-15 (skin only) or 4E-BP2 in the head kidney, spleen and skin of young grass carp. Finally, based on the percent weight gain (PWG), the morbidity of skin haemorrhages and lesions, the ACP activity in the head kidney and the lysozyme activity in spleen, the optimal dietary selenium requirements for young grass carp were estimated to be 0.546-0.604 mg/kg diet. In summary, selenium deficiency decreased the growth performance and impaired the immune function in the head kidney, spleen and skin of young grass carp.

The integrative metabolomic-transcriptomic landscape of glioblastome multiforme

The purpose of this study was to map the landscape of metabolic-transcriptional alterations in glioblastoma multiforme. Omic-datasets were acquired by metabolic profiling (1D-NMR spectroscopy n=33 Patient) and transcriptomic profiling (n=48 Patients). Both datasets were analyzed by integrative network modeling. The computed model concluded in four different metabolic-transcriptomic signatures containing: oligodendrocytic differentiation, cell-cycle functions, immune response and hypoxia. These clusters were found being distinguished by individual metabolism and distinct transcriptional programs. The study highlighted the association between metabolism and hallmarks of oncogenic signaling such as cell-cycle alterations, immune escape mechanism and other cancer pathway alterations. In conclusion, this study showed the strong influence of metabolic alterations in the wide scope of oncogenic transcriptional alterations.

The impaired immune function and structural integrity by dietary iron deficiency or excess in gill of fish after infection with Flavobacterium columnare: Regulation of NF-κB, TOR, JNK, p38MAPK, Nrf2 and MLCK signalling

The aim of this study was to investigate the effects and potential mechanisms of dietary iron on immune function and structural integrity in gill of young grass carp (Ctenopharyngodon idella). A total of 630 grass carp (242.32 ± 0.58 g) were fed diets containing graded levels of iron at 12.15 (basal diet), 35.38, 63.47, 86.43, 111.09, 136.37 and 73.50 mg/kg for 60 days. Subsequently, a challenge test was conducted by infection with Flavobacterium columnare to investigate the effects of dietary iron on gill immune function and structural integrity in young grass carp. First, the results indicated that compared with the optimal iron level, iron deficiency decreased lysozyme (LZ) and acid phosphatase (ACP) activities, complement 3 (C3), C4 and immunoglobulin M (IgM) contents, and down-regulated the mRNA levels of antibacterial peptides, anti-inflammatory cytokines (except IL-4/13B), inhibitor of κBα (IκBα), target of rapamycin (TOR) and ribosomal protein S6 kinase 1 (S6K1). In contrast, iron deficiency up-regulated the mRNA levels of pro-inflammatory cytokines (except IL-6 and IFN-γ2), nuclear factor κB p65 (NF-κBp65), IκB kinases α (IKK), IKKβ, IKKγ, eIF4E-binding protein 1 (4E-BP1) and 4E-BP2 in gill of young grass carp, indicating that iron deficiency could impair immune function in fish gill. Second, iron deficiency down-regulated the mRNA levels of inhibitor of apoptosis protein (IAP) and myeloid cell leukemia 1 (Mcl-1), decreased activities and mRNA levels of antioxidant enzymes, down-regulated the mRNA levels of NF-E2-related factor 2 (Nrf2) and tight junction proteins (except claudin-12 and -15), and simultaneously increased malondialdehyde (MDA), protein carbonyl (PC) and reactive oxygen species (ROS) contents. Iron deficiency also up-regulated mRNA levels of cysteinyl aspartic acid-protease (caspase) -2, -7, -8, -9, Fas ligand (FasL), apoptotic protease activating factor-1 (Apaf-1), B-cell-lymphoma-2 associated X protein (Bax), p38 mitogen-activated protein kinase (p38MAPK), Kelch-like ECH-associating protein (Keap) 1a, Keap1b, claudin-12, -15 and MLCK, indicating that iron deficiency could disturb the structural integrity of gill in fish. Third, iron excess impaired immune function and structural integrity in gill of young grass carp. Forth, there was a better effect of ferrous fumarate than ferrous sulfate in young grass carp. Finally, the iron requirements based on ability against gill rot, ACP activity and MDA content in gill of young grass carp were estimated to be 76.52, 80.43 and 83.17 mg/kg, respectively.

Considering choline as methionine precursor, lipoproteins transporter, hepatic promoter and antioxidant agent in dairy cows

During the transition period, fatty liver syndrome may be caused in cows undergo negative energy balance, ketosis or hypocalcemia, retained placenta or mastitis problems. During the transition stage, movement of non-esterified fatty acids (NEFA) increases into blood which declines the hepatic metabolism or reproduction and consequently, lactation performance of dairy cows deteriorates. Most of studies documented that, choline is an essential nutrient which plays a key role to decrease fatty liver, NEFA proportion, improve synthesis of phosphatidylcholine, maintain lactation or physiological function and work as anti-oxidant in the transition period of dairy cows. Also, it has a role in the regulation of homocysteine absorption through betaine metabolite which significantly improves plasma α-tocopherol and interaction among choline, methionine and vitamin E. Many studies reported that, supplementation of rumen protected form of choline during transition time is a sustainable method as rumen protected choline (RPC) perform diverse functions like, increase glucose level or energy balance, fertility or milk production, methyl group metabolism, or signaling of cell methionine expansion or methylation reactions, neurotransmitter synthesis or betaine methylation, increase transport of lipids or lipoproteins efficiency and reduce NEFA or triacylglycerol, clinical or sub clinical mastitis and general morbidity in the transition dairy cows. The purpose of this review is that to elucidate the choline importance and functions in the transition period of dairy cows and deal all morbidity during transition or lactation period. Furthermore, further work is needed to conduct more studies on RPC requirements in dairy cows ration under different feeding conditions and also to elucidate the genetic and molecular mechanisms of choline in ruminants industry.

Intestinal immune responses of Jian carp against Aeromonas hydrophila depressed by choline deficiency: Varied change patterns of mRNA levels of cytokines, tight junction proteins and related signaling molecules among three intestinal segments

This study aimed to investigate the effects of choline deficiency on intestinal inflammation of fish after Aeromonas hydrophila infection and the potential molecular mechanisms. Juvenile Jian carp (Cyprinus carpio var. Jian) were fed two diets containing choline at 165 (deficient group) and 607 mg/kg diet respectively for 65 days. Choline deficiency decreased intestinal lysozyme activity, C3 and IgM contents, increased acid phosphatase activity, downregulated mRNA levels of antimicrobial peptides [liver-expressed antimicrobial peptide (LEAP) 2A, LEAP-2B, hepcidin and defensin], cytokines [interleukin (IL) 6a, tumor necrosis factor α (TNF-α), interferon γ2b (IFN-γ2b), IL-6b and transforming growth factor β2 (TGF-β2) only in proximal intestine, IL-10 in mid and distal intestine], immune-related signaling molecules [Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), nuclear factor kappa B (NF-κB), inhibitor of NF-κB (IκB), Janus kinase 3 (JAK3), and signal transducers and activators of transcription 5 (STAT5)], tight junction proteins (claudin 3b, claudin 3c, claudin 11 and occludin), and mitogen-activated protein kinases p38 (p38^MAPK) in proximal and distal intestine of juvenile Jian carp after A. hydrophila challenge. In contrast, choline deficiency upregulated mRNA levels of antimicrobial peptides (LEAP-2A, LEAP-2B, hepcidin and defensin), cytokines (IL-6b, IFN-γ2b and TGF-β2), immune-related signaling molecules (TLR4, MyD88, NF-κB, IκB, JAK3, STAT4 in three intestinal segments, and STAT6), claudin 11, and p38^MAPK in mid intestine of fish. This study provides new finding that choline deficiency-induced immune responses against A. hydrophila infection were varied among three intestinal segments in fish.

The decreased growth performance and impaired immune function and structural integrity by dietary iron deficiency or excess are associated with TOR, NF-κB, p38MAPK, Nrf2 and MLCK signaling in head kidney, spleen and skin of grass carp (Ctenopharyngodon idella)

This study was conducted to investigate the effects of dietary iron on the growth, and immune function and structural integrity in head kidney, spleen and skin as well as the underlying signaling of young grass carp (Ctenopharyngodon idella). Total 630 grass carp (242.32 ± 0.58 g) were fed diets containing graded levels of iron at 12.15 (basal diet), 35.38, 63.47, 86.43, 111.09, 136.37 mg/kg (diets 2-6 were added with ferrous fumarate) and 73.50 mg/kg (diet 7 was added with ferrous sulfate) diet for 60 days. Then, a challenge test was conducted by infection of Aeromonas hydrophila for 14 days. The results firstly showed that compared with optimal iron level, iron deficiency decreased lysozyme (LZ) and acid phosphatase (ACP) activities, complement 3 (C3), C4 and immunoglobulin M (IgM) contents and down-regulated the mRNA levels of antibacterial peptides, anti-inflammatory cytokines, inhibitor of κBα (IκBα), target of rapamycin (TOR) and ribosomal protein S6 kinase 1 (S6K1), whereas up-regulated the mRNA levels of pro-inflammatory cytokines, nuclear factor kappa B (NF-κB) p65, IκB kinases β (IKKβ) and eIF4E-binding protein (4E-BP) in head kidney and spleen of young grass carp (P < 0.05), indicating that iron deficiency impaired immune function in head kidney and spleen of fish. Secondly, iron deficiency down-regulated the mRNA levels of B-cell lymphoma-2 (Bcl-2), myeloid cell leukemia 1 (Mcl-1), and inhibitor of apoptosis protein (IAP), and decreased activities and mRNA levels of antioxidant enzymes, down-regulated the mRNA levels of NF-E2-related factor 2 (Nrf2) and tight junction complexes, and up-regulated mRNA levels of cysteinyl aspartic acid-protease (caspase) -2, -3, -7, -8, -9, apoptotic protease activating factor-1 (Apaf-1), Bcl-2 associated X protein (Bax), Fas ligand (FasL), p38 mitogen-activated protein kinase (p38MAPK), Kelch-like ECH-associating protein (Keap) 1a, Keap1b, claudin-12 and myosin light chain kinase (MLCK), and increased malondialdehyde (MDA), protein carbonyl (PC) and reactive oxygen species (ROS) contents in head kidney and spleen of young grass carp (P < 0.05), indicating that iron deficiency impaired structural integrity in head kidney and spleen of fish. Thirdly, iron deficiency increased skin hemorrhage and lesion morbidity, and impaired immune function and structural integrity in skin of fish. Fourthly, iron excess decreased growth and impaired the immune function and structural integrity in head kidney, spleen and skin of fish. Besides, in young grass carp, based on PWG and ability against skin hemorrhage and lesion, the efficacy of ferrous fumarate relative to ferrous sulfate was 140.32% and 126.48%, respectively, and the iron requirements based on PWG, ability against skin hemorrhage and lesion, ACP activities and MDA contents in head kidney and spleen were estimated to be 75.65, 87.03, 79.74, 78.93, 83.17 and 82.14 mg/kg diet (based on ferrous fumarate), respectively.

Plasma immune protein analysis in the orange-spotted grouper Epinephelus coioides: Evidence for altered expressions of immune factors associated with a choline-supplemented diet

This study aimed to unravel the regulatory roles of choline in activating immune responses and disease resistance of the orange-spotted grouper Epinephelus coioides. Fish were fed a choline-supplemented diet at 1 g kg^-1 of feed for 30 days. Fish fed a fish meal basal diet without choline-supplement served as controls. At the end of the feeding trial, fish were challenged with Vibrio alginolyticus. Meanwhile, plasma proteomics of fish in each group were also evaluated by two-dimensional gel electrophoresis (2-DE), and differentially expressed proteins were identified by tandem mass spectrophotometry (MS/MS), then a Western blot analysis or real-time polymerase chain reaction was used to confirm differential expressions of immune-enhancing proteins. Results showed that choline significantly increased survival of E. coioides 48 days after being injected with V. alginolyticus. From maps of plasma proteins, a comparative analysis between the control and choline groups revealed that 111 spots matched, with 26 altered expression spots in the choline group. Of these 26 spots, 16 were upregulated and 10 downregulated. After protein identification by reverse-phase nano-high-performance liquid chromatography-electrospray ionization MS/MS analysis, eight of 26 proteins were found to be immune-related proteins, all of which were upregulated, including complement 3 (C3), alpha-2-macroglobulin-P-like isoform (A2M), fibrinogen beta chain precursor (FBG), and immunoglobulin heavy constant mu (Ighm) proteins. Expression of the A2M protein and A2M enzyme activity in plasma of fish fed choline significantly increased compared to the control group. Additionally, A2M messenger (m)RNA transcripts were also upregulated in the liver and kidneys. Significantly higher C3 expressions at both the mRNA and protein levels were detected in the liver of fish in the choline group. Moreover, FBG gene expressions in the liver and kidneys significantly increased, while Ighm increased in the kidneys and spleen of fish in the choline group. Our results suggest that dietary administration of choline can protect grouper against bacterial infections through activating the complement system, thereby inducing antiprotease activity and natural antibodies that play important roles in the innate immune system of fish.

A Comparative Study on Antioxidant System in Fish Hepatopancreas and Intestine Affected by Choline Deficiency: Different Change Patterns of Varied Antioxidant Enzyme Genes and Nrf2 Signaling Factors

The liver and intestine are susceptible to the oxidative damage which could result in several diseases. Choline deficiency induced oxidative damage in rat liver cells. Thus, this study aimed to investigate the potential molecular mechanisms responsible for choline deficiency-induced oxidative damage. Juvenile Jian carp were fed diets differing in choline content [165 (deficient group), 310, 607, 896, 1167 and 1820 mg/kg diet] respectively for 65 days. Oxidative damage, antioxidant enzyme activities and related gene expressions in the hepatopancreas and intestine were measured. Choline deficiency decreased choline and phosphatidylcholine contents, and induced oxidative damage in both organs, as evidenced by increased levels of oxidative-stress markers (malondialdehyde, protein carbonyl and 8-hydroxydeoxyguanosine), coupled with decreased activities of antioxidant enzymes [Copper-zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST)]. However, choline deficiency increased glutathione contents in the hepatopancreas and intestine. Furthermore, dietary choline deficiency downregulated mRNA levels of MnSOD, GPx1b, GST-rho, mGST3 and Kelch-like ECH associating protein 1 (Keap1b) in the hepatopancreas, MnSOD, GPx1b, GPx4a, GPx4b, GST-rho, GST-theta, GST-mu, GST-alpha, GST-pi and GST-kappa in the intestine, as well as intestinal Nrf2 protein levels. In contrast, choline deficiency upregulated the mRNA levels of GPx4a, GPx4b, mGST1, mGST2, GST-theta, GST-mu, Keap1a and PKC in the hepatopancreas, mGST3, nuclear factor erythoid 2-related factor 2 (Nrf2) and Keap1a in the intestine, as well as hepatopancreatic Nrf2 protein levels. This study provides new evidence that choline deficiency-induced oxidative damage is associated with changes in the transcription of antioxidant enzyme and Nrf2/Keap1 signaling molecules in the hepatopancreas and intestine. Additionally, this study firstly indicated that choline deficiency induced varied change patterns of different GPx and GST isoforms. Meanwhile, the changes of some GPx and GST isoforms caused by choline deficiency in the intestine were contrary to those in the hepatopancreas.

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

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.

Dietary vitamin C deficiency depressed the gill physical barriers and immune barriers referring to Nrf2, apoptosis, MLCK, NF-κB and TOR signaling in grass carp (Ctenopharyngodon idella) under infection of Flavobacterium columnare

This study explored the effects of vitamin C on the physical barriers and immune barriers, and relative mRNA levels of signaling molecules in the gill of grass carp (Ctenopharyngodon idella) under infection of Flavobacterium columnare. The results indicated that compared with optimal vitamin C supplementation, vitamin C deficiency (2.9 mg/kg diet) (1) increased reactive oxygen species, malondialdehyde and protein carbonyl (PC) contents (P < 0.05), decreased the copper/zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase activities and mRNA levels (P < 0.05), and glutathione and vitamin C contents (P < 0.05), down-regulated NF-E2-related factor 2 mRNA level (P < 0.05), and up-regulated Kelch-like ECH-associating protein (Keap) 1a (rather than Keap1b) mRNA level (P < 0.05) in the gill of grass carp under infection of F. columnare, suggesting that vitamin C deficiency induced oxidative injury in fish gill; (2) up-regulated caspase-3, -7, -8, -9, Fas ligand, B-cell lymphoma protein 2 associated X protein, apoptotic protease activating factor-1 mRNA levels (P < 0.05), and down-regulated inhibitor of apoptosis protein and B-cell lymphoma-2 (rather than myeloid cell leukemia-1) mRNA level (P < 0.05) in the gill of grass carp under infection of F. columnare, suggesting that vitamin C deficiency aggravated cell apoptosis in fish gill; (3) up-regulated pore-forming TJs Claudin-12, 15a, -15b, and related signaling molecules myosin light chain kinase, p38 mitogen-activated protein kinase (rather than c-Jun N-terminal kinases) mRNA levels (P < 0.05), and down-regulated barrier-forming TJs Occludin, zonula occludens (ZO) 1, ZO-2, Claudin-c, -3c, -7a, -7b mRNA levels (P < 0.05) in the gill of grass carp under infection of F. columnare, suggesting that vitamin C deficiency disrupted tight junctional complexes in fish gill; (4) decreased lysozyme and acid phosphatase (ACP) activities, and complement 3 (C3), C4 and IgM contents (P < 0.05), down-regulated the mRNA levels of antimicrobial peptides liver expressed antimicrobial peptide (LEAP) 2A, LEAP-2B, Hepcidin, β-defensin mRNA levels (P < 0.05) in the gill of grass carp under infection of F. columnare, suggesting that vitamin C deficiency decrease fish gill immune function; (5) down-regulated the mRNA levels of anti-inflammatory cytokines-related factors interleukin 10 (IL-10), IL-11, transforming growth factor (TGF) β1, TGF-β2, inhibitor of κBa and eIF4E-binding protein 1 (4E-BP1) (rather than 4E-BP2) (P < 0.05), and up-regulated pro-inflammatory cytokines-related factors interferon γ2, IL-1β, IL-6, IL-8, IL-12 P35, IL-12 P40, nuclear factor κB (NF-κB) p65 (rather than NF-κB p52), IκB kinases (IKK) (only IKKα and IKKγ), target of rapamycin and ribosomal protein S6 kinase 1 mRNA levels (P < 0.05) in the gill of grass carp under infection of F. columnare, suggesting that vitamin C deficiency aggravated fish gill inflammation. In conclusion, vitamin C deficiency disrupted physical barriers and immune barriers, and regulated relative mRNA levels of signaling molecules in fish gill. The vitamin C requirement for against gill rot morbidity of grass carp (264-1031 g) was estimated to be 156.0 mg/kg diet. In addition, based on the gill biochemical indices (antioxidant indices MDA, PC and vitamin C contents, and immune indices LA and ACP activity) the vitamin C requirements for grass carp (264-1031 g) were estimated to be 116.8, 156.6, 110.8, 57.8 and 134.9 mg/kg diet, respectively.

Dietary choline deficiency and excess induced intestinal inflammation and alteration of intestinal tight junction protein transcription potentially by modulating NF-κB, STAT and p38 MAPK signaling molecules in juvenile Jian carp

This study investigated the effects of choline on intestinal mucosal immune and the possible mechanisms in fish by feeding juvenile Jian carp (Cyprinus carpio var. Jian) with graded levels of dietary choline (165-1820 mg/kg diet) for 65 days. The results firstly showed that choline deficiency induced inflammatory infiltration in the proximal intestine (PI), mid intestine (MI) and distal intestine (DI) of fish. Meanwhile, compared with the optimal choline group, choline deficiency decreased the activities of lysozyme and acid phosphatase, contents of complement 3 and IgM in the intestine, downregulated the mRNA levels of antimicrobial peptides (liver-expressed antimicrobial peptide (LEAP) 2A and defensin-3 in the PI and MI, LEAP-2B and hepcidin in the PI, MI and DI), anti-inflammatory cytokines (interleukin (IL) 10 and transforming growth factor β2 in the PI, MI and DI), and signaling molecule IκB in the PI, MI and DI; while upregulated the mRNA levels of pro-inflammatory cytokines (IL-6a and tumor necrosis factor α in the MI and DI, interferon γ2b in the PI and MI, IL-1β and IL-6b in the PI, MI and DI), and signaling molecules (Toll-like receptor 4 in the MI, myeloid differentiation primary response 88 in the PI and MI, Janus kinase 3 and tyrosine kinase 2 in the MI and DI, nuclear factor kappa B (NF-κB), signal transducers and activators of transcription (STAT) 4 and STAT5 in the PI, MI and DI) of juvenile Jian carp, further indicating that choline deficiency caused inflammation and immunity depression in the intestine of fish. But choline deficiency decreased the PI IL-6a mRNA level, and increased the DI LEAP-2A and defensin-3 mRNA levels with unknown reasons. Furthermore, dietary choline deficiency downregulated mRNA levels of tight junction (TJ) proteins (claudin 3c in the PI and MI, claudin 7, claudin 11 and occludin in the PI, MI and DI) and signaling molecule mitogen-activated protein kinases p38 in the PI, MI and DI of juvenile Jian carp, whereas upregulated the mRNA levels of claudin 3b in the MI and DI, and claudin 3c in the DI. Moreover, the excessive choline exhibited negative effects on intestinal immunity and TJ proteins that were similar to the choline deficiency. In summary, dietary choline deficiency or excess caused the depression of intestinal mucosal immune by inducing inflammation and dysfunction of the intestinal physical barrier, and regulating related signaling molecules of fish.

Regulation of Nutritional Metabolism in Transition Dairy Cows: Energy Homeostasis and Health in Response to Post-Ruminal Choline and Methionine

This study investigated the effects of rumen-protected methionine (RPM) and rumen-protected choline (RPC) on energy balance, postpartum lactation performance, antioxidant capacity and immune response in transition dairy cows. Forty-eight multiparous transition cows were matched and divided into four groups: control, 15 g/d RPC, 15 g/d RPM or 15 g/d RPC + 15 g/d RPM. Diet samples were collected daily before feeding, and blood samples were collected weekly from the jugular vein before morning feeding from 21 days prepartum to 21 days postpartum. Postpartum dry matter intake (DMI) was increased by both additives (P < 0.05), and energy balance values in supplemented cows were improved after parturition (P < 0.05). Both RPC and RPM decreased the plasma concentrations of non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) (P < 0.05), but increased the plasma levels of glucose, very-low-density lipoprotein (VLDL) and apolipoprotein B100 (ApoB 100, P < 0.05). The supplements improved milk production (P < 0.05), and increased (P < 0.05) or tended to increase (0.05 < P < 0.10) the contents of milk fat and protein. The post-ruminal choline and methionine elevated the blood antioxidant status, as indicated by total antioxidant capacity (T-AOC), glutathione peroxidase (GSH-Px) activity and the vitamin E concentration (P < 0.05), and reduced the plasma malondialdehyde (MDA) level (P < 0.05). Furthermore, RPM and RPC elevated the plasma interleukin 2 (IL-2) concentration and the CD4⁺/CD8⁺ T lymphocyte ratio in peripheral blood (P < 0.05). Alternatively, the levels of tumor necrosis factor-α (TNF-α) and IL-6 were decreased by RPM and RPC (P < 0.05). Overall, the regulatory responses of RPC and RPM were highly correlated with time and were more effective in the postpartum cows. The results demonstrated that dietary supplementation with RPC and RPM promoted energy balance by increasing postpartal DMI and regulating hepatic lipid metabolism, improved postpartum lactation performance and enhanced antioxidant capacity and immune function of transition dairy cows.

Dietary low or excess levels of lipids reduced growth performance, and impaired immune function and structure of head kidney, spleen and skin in young grass carp (Ctenopharyngodon idella) under the infection of Aeromonas hydrophila

Our study explored the effect of dietary lipids on growth and immunity and structure (head kidney, spleen and skin) of young grass carp (Ctenopharyngodon idella). A total of 540 young grass carp with an average initial weight of 261.41 ± 0.53 g were fed diets containing six graded levels of lipids at 5.9-80.1 g/kg diet for 8 weeks. After that, a challenge trial was conducted by injection of Aeromonas hydrophila over 2 weeks. The results indicated that compared with optimal lipids supplementation, low and excess levels of lipids down-regulated the mRNA levels of antimicrobial peptides, anti-inflammatory cytokines, inhibitor of κBα (IκBα) and ribosomal p70S6 kinase (S6K1), and up-regulated pro-inflammatory cytokines, nuclear factor κB p65 (NF-κB p65), NF-κB c-Rel (not p52), IκB kinase α (IKKα), IKKβ, IKKγ, and eIF4E-binding protein (4EBP) mRNA levels in the head kidney and spleen of young grass carp (P < 0.05). Low or excess levels of lipids also increased reactive oxygen species (ROS) production and malondialdehyde (MDA) and protein carbonyl (PC) contents, reduced the activities of antioxidant enzymes (P < 0.05), down-regulate the relative mRNA levels of antioxidant enzymes and NF-E2-related factor 2 (Nrf2), and up-regulated the expression levels of Kelch-like ECH-associating protein 1a (Keap1a) and Keap1b in the head kidney and spleen. In addition, low or excess levels of lipids down-regulated the mRNA levels of B-cell lymphoma-2 (Bcl-2) and inhibitor of apoptosis protein (IAP) in the head kidney and spleen, whereas up-regulated the mRNA levels of apoptotic protease activating factor-1 (Apaf-1), caspase 3, 7, 8 and 9 mRNA levels in the head kidney and spleen and Fas ligand (FasL) mRNA levels in the spleen of young grass carp, suggesting that low or excess levels of lipids could decrease the head kidney and spleen immune function, induce oxidative damage and apoptosis and impair antioxidant system of young grass carp. At last, low or excess levels of lipids also impaired the immune function and structure in the skin of young grass carp. Based on the quadratic regression analysis for PWG, skin haemorrhage and lesions morbidity and IgM content, the dietary lipids requirements for young grass carp were estimated to be 43.7, 60.2, 55.0 and 52.1 g/kg diet, respectively.

Dietary choline regulates antibacterial activity, inflammatory response and barrier function in the gills of grass carp (Ctenopharyngodon idella)

An 8-week feeding trial was conducted to determine the effects of graded levels of choline (197-1795 mg/kg) on antibacterial properties, inflammatory status and barrier function in the gills of grass carp. The results showed that optimal dietary choline supplementation significantly improved lysozyme and acid phosphatase activities, complement component 3 (C3) content, and the liver expressed antimicrobial peptide 2 and Hepcidin mRNA levels in the gills of fish (P < 0.05). In addition, appropriate dietary choline significantly decreased the oxidative damage, which might be partly due to increase copper, zinc superoxide dismutase (Cu/Zn-SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) activities and increased glutathione content in the gills of fish (P < 0.05). Moreover, appropriate dietary choline significantly up-regulated the mRNA levels of interleukin 10 and transforming growth factor β1, Zonula occludens 1, Occludin, Claudin-b, c, 3 and 12, inhibitor of κBα, target of rapamycin, Cu/Zn-SOD, CAT, GR, GPx, GST and NF-E2-related factor 2 in the gills of fish (P < 0.05). Conversely, appropriate dietary choline significantly down-regulated the mRNA levels of pro-inflammatory cytokines, tumor necrosis factor α, interleukin 8, interferon γ, interleukin 1β, and related signaling factors, nuclear factor kappa B p65, IκB kinase β, IκB kinase γ, myosin light chain kinase and Kelch-like-ECH-associated protein 1a (Keap1a) in the gills of fish (P < 0.05). However, choline did not have a significant effect on the mRNA levels of IκB kinase α, Claudin-15 and Keap1b in the gills of fish. Collectively, appropriate dietary choline levels improved gill antibacterial properties and relative gene expression levels of tight junction proteins, and decreased inflammatory status, as well as up-regulated the mRNA levels of related signaling molecules in the gills of fish. Based on gill C3 content and AHR activity, the dietary choline requirements for young grass carp (266.5-787.1 g) were estimated to be 1191.0 and 1555.0 mg/kg diet, respectively.

Dietary vitamin C deficiency depresses the growth, head kidney and spleen immunity and structural integrity by regulating NF-κB, TOR, Nrf2, apoptosis and MLCK signaling in young grass carp (Ctenopharyngodon idella)

This study investigated the effects of dietary vitamin C on the growth, and head kidney, spleen and skin immunity, structural integrity and related signaling molecules mRNA expression levels of young grass carp (Ctenopharyngodon idella). A total of 540 grass carp (264.37 ± 0.66 g) were fed six diets with graded levels of vitamin C (2.9, 44.2, 89.1, 133.8, 179.4 and 224.5 mg/kg diet) for 10 weeks. Subsequently, a challenge test was conducted by injection of Aeromonas hydrophila and the survival rate recorded for 14 days. The results indicated that compared with optimal vitamin C supplementation, vitamin C deficiency (2.9 mg/kg diet) decreased lysozyme (LA) and acid phosphatase (ACP) activities, and complement 3 and complement 4 (C4) contents (P < 0.05), down-regulated the mRNA levels of antimicrobial peptides [liver expressed antimicrobial peptide (LEAP) 2A, LEAP-2B, hepcidin, β-defensin] and anti-inflammatory cytokines-related factors, interleukin (IL) 4/13A, IL-4/13B (only in head kidney), IL-10, IL-11, transforming growth factor (TGF) β1, TGF-β2, inhibitor of κBα and eIF4E-binding protein 1 (P < 0.05), and up-regulated pro-inflammatory cytokines-related factors, tumor necrosis factor α, interferon γ2, IL-1β, IL-6, IL-8, IL-12 P35 (only in spleen), IL-12 P40, IL-15, IL-17D, nuclear factor κB p65, IκB kinases (IKKα, IKKβ, IKKγ), target of rapamycin and ribosomal protein S6 kinase 1 mRNA levels (P < 0.05) in the head kidney and spleen under injection fish of A. hydrophila, suggesting that vitamin C deficiency could decrease fish head kidney and spleen immunity and cause inflammation. Meanwhile, compared with optimal vitamin C supplementation, vitamin C deficiency decreased the activities and mRNA levels of copper/zinc superoxide dismutase, manganese superoxide dismutase (MnSOD), catalase, glutathione peroxidase, glutathione S-transferases and glutathione reductase (P < 0.05), and down-regulated zonula occludens (ZO) 1, ZO-2, Claudin-b, -c, -3c, -7a, -7b, B-cell lymphoma-2, inhibitor of apoptosis protein, NF-E2-related factor 2 mRNA levels (P < 0.05), increased reactive oxygen species (ROS), malondialdehyde (MDA) and protein carbonyl contents (P < 0.05), and up-regulated Claudin-12, 15a, -15b, Fas ligand, mitogen-activated protein kinase kinase 6, p38 mitogen-activated protein kinase, B-cell lymphoma protein 2 associated X protein, apoptotic protease activating factor-1, caspase-3, -7, -8, -9, Kelch-like ECH-associating protein (Keap) 1a and Keap 1b mRNA levels (P < 0.05) in the head kidney and spleen under injection fish of A. hydrophila, suggesting that vitamin C deficiency could decrease fish head kidney and spleen structural integrity through depression of antioxidative ability, induction of apoptosis and disruption of tight junctional complexes. In addition, except the activities of ACP and MnSOD, and mRNA expression levels of TGF-β1, Occludin and MnSOD, the effect of vitamin C on fish head kidney, spleen and skin immunity and structural integrity other indicators model are similar under infection of A. hydrophila. Finally, the vitamin C requirement for the growth performance (PWG) of young grass carp was estimated to be 92.8 mg/kg diet. Meanwhile, the vitamin C requirement for against skin lesion morbidity of young grass carp was estimated to be 122.9 mg/kg diet. In addition, based on the biochemical indices [immune indices (LA activity in the head kidney and C4 content in the spleen) and antioxidant indices (MDA content in the head kidney and ROS content in the spleen)] the vitamin C requirements for young grass carp were estimated to be 131.2, 137.5, 135.8 and 129.8 mg/kg diet, respectively.

Dietary alpha-linolenic acid/linoleic acid ratios modulate intestinal immunity, tight junctions, anti-oxidant status and mRNA levels of NF-κB p65, MLCK and Nrf2 in juvenile grass carp (Ctenopharyngodon idella)

This study was conducted to investigate the effects of dietary alpha-linolenic acid/linoleic acid (ALA/LNA) ratios on the immune response, tight junctions, antioxidant status and immune-related signaling molecules mRNA levels in the intestine of juvenile grass carp (Ctenopharyngodon idella). A total of 1260 juvenile grass carp with an average initial weight of 8.78 ± 0.03 g were fed diets with different ALA/LNA ratios (0.01, 0.34, 0.68, 1.03, 1.41, 1.76 and 2.15) for 60 days. Results indicated that ALA/LNA ratio of 1.03 significantly increased acid phosphatase, lysozyme activities and complement C3 contents, promoted interleukin 10, transforming growth factor β1 and κB inhibitor α mRNA abundance, whereas suppressed pro-inflammatory cytokines (interleukin 1β, interleukin 8, tumor necrosis factor α and interferon γ2) and signal molecules (IκB kinase β, IκB kinase γ and nuclear factor κB p65) mRNA levels in the intestine (P < 0.05), suggesting that optimal dietary ALA/LNA ratio improved intestinal immune response of juvenile fish. Additionally, ALA/LNA ratio of 1.03 significantly promoted Claudin-3, Claudin-b, Claudin-c, Occludin and ZO-1 gene transcription, whereas reduced Claudin-15a and myosin light-chain kinase mRNA levels in the intestine, suggesting that appropriate dietary ALA/LNA ratio strengthened tight junctions in the intestine of juvenile fish. Meanwhile, ALA/LNA ratio of 1.03 noticeably elevated glutathione contents, copper/zinc superoxide dismutase, glutathione peroxidase, glutathione S-transferase and glutathione reductase activities and mRNA levels, as well as signaling molecule nuclear factor erythoid 2-related factor 2 gene transcriptional abundance in the intestine, suggesting that proper ratio of dietary ALA/LNA ameliorate the intestinal antioxidant status of juvenile fish. Based on the quadratic regression analysis of the complement C3 content in the distal intestine and malondialdehyde content in the whole intestine, optimal ALA/LNA ratio for maximum growth of juvenile grass carp (8.78-72.00 g) were estimated to be 1.13 and 1.12, respectively.

Dietary myo-inositol modulates immunity through antioxidant activity and the Nrf2 and E2F4/cyclin signalling factors in the head kidney and spleen following infection of juvenile fish with Aeromonas hydrophila

This study was conducted to investigate the effects of the dietary vitamin myo-inositol (MI), on the immunity and structural integrity of the head kidney and spleen following infection of fish with the major freshwater pathogen bacterial Aeromonas hydrophila. The results demonstrated for the first time that MI deficiency depressed the lysozyme and acid phosphatase (ACP) activities and the complement 3 (C3) and C4 contents in the head kidney and spleen compared with the optimal MI levels, indicating that MI deficiency decreased the immunity of these important fish immune organs. The depression in immunity due to MI deficiency was partially related to oxidative damage [indicated by increases in the malondialdehyde (MDA) and protein carbonyl (PC) contents] that was in turn partially due to the decreased glutathione (GSH) content and the disturbances in antioxidant enzyme activities [total superoxide dismutase (T-SOD), CuZnSOD, MnSOD, catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR)]. MI deficiency inhibited the antioxidant-related gene transcription [CuZnSOD, MnSOD, CAT, GPx1a, GR and NF-E2-related factor 2 (Nrf2)] in the head kidney and spleen following infection of the fish with A. hydrophila. The oxidative damage due to MI deficiency also resulted in the inhibition of proliferation-associated signalling (cyclin D1, cyclin A, cyclin E and E2F4). Thus, MI deficiency partially inhibited damage repair. Excessive MI exhibited negative effects that were similar to MI deficiency, whereas the optimal MI content reversed those indicators. These observations indicated that an MI deficiency or excess could cause depression of the immune system that might be partially related to oxidative damage, antioxidant disturbances, and the inhibition of the proliferation-associated signalling in the head kidney and spleen following infection of fish with A. hydrophila. Finally, the optimal MI levels were 660.7 (based on ACP) and 736.8 mg kg(-1) diet (based on MDA) in the head kidney and 770.5 (based on ACP) and 766.9 mg kg(-1) diet (based on MDA) in the spleen of juvenile Jian carp.

Deficiency of dietary niacin impaired intestinal mucosal immune function via regulating intestinal NF-κB, Nrf2 and MLCK signaling pathways in young grass carp (Ctenopharyngodon idella)

This study investigated the effects of dietary niacin on intestinal mucosal immune and physical barrier, and relative mRNA levels of signaling molecules in the intestine of young grass carp (Ctenopharyngodon idella). A total of 540 young grass carp (255.63 ± 0.41 g) were fed six diets containing graded levels of niacin (3.95, 14.92, 24.98, 35.03, 44.97 and 55.01 mg/kg diet) for 8 weeks. Results observed that niacin deficiency decreased lysozyme (LA) and acid phosphatase (ACP) activities, and complement 3 (C3) content in the intestine (P < 0.05), down-regulated mRNA levels of liver expressed antimicrobial peptide 2 (LEAP-2), hepcidin, interleukin 10, transforming growth factor β1 and inhibitor of κBα (IκBα) (P < 0.05), up-regulated tumor necrosis factor α, interleukin 1β, interferon γ2, interleukin 8, nuclear factor kappa B P65 (NF-κB P65), IκB kinase α (IKKα), IκB kinase β (IKKβ) and IκB kinase γ (IKKγ) in all intestinal segments of young grass carp (P < 0.05). In addition, niacin deficiency increased reactive oxygen species (ROS), malondialdehyde (MDA) and protein carbonyl (PC) contents, decreased glutathione content, and copper/zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferases (GST) and glutathione reductase (GR) activities in the intestine of young grass carp (P < 0.05). Additionally, niacin deficiency decreased mRNA levels of CuZnSOD, MnSOD, GPx, CAT, GST, GR, Claudin b, Claudin 3, Claudin c, Occludin, ZO-1, Claudin 15 and NF-E2-related factor 2 (Nrf2) (P < 0.05), and increased Claudin 12, Kelch-like ECH-associating protein 1a (Keap1a), myosin light-chain kinase (MLCK) and p38 mitogen-activated protein kinase (p38 MAPK) mRNA expression levels in the intestine of young grass carp (P < 0.05), while the mRNA level of Kelch-like ECH-associating protein 1b (Keap1b) did not change (P > 0.05). In conclusion, niacin deficiency decreased intestinal mucosal immune and intestinal physical function, as well as regulated mRNA levels of NF-κB P65, IκBα, IKKα, IKKβ, IKKγ, Nrf2, Keap1a, p38 MAPK and MLCK in the intestine of young grass carp. Based on the broken-line model analysis of intestinal lysozyme activity, the requirement of niacin for young grass carp (255.63 ± 0.41 g) were estimated to be 39.80 mg/kg diet.

Modulation of immune response, physical barrier and related signaling factors in the gills of juvenile grass carp (Ctenopharyngodon idella) fed supplemented diet with phospholipids

This study was conducted to investigate the effects of dietary phospholipids (PL) on the gill immune response and physical barrier of juvenile grass carp (Ctenopharyngodon idella). A total of 1080 juvenile grass carp with an average initial weight of 9.34 ± 0.03 g were fed six semi-purified diets containing 0.40% (unsupplemented control group), 1.43%, 2.38%, 3.29%, 4.37% and 5.42% PL for 2 months. Compared with the control group, optimal PL supplementation increased (P < 0.05): (1) the lysozyme activity, acid phosphatase activity, complement component 3 (C3) content, liver expressed antimicrobial peptide 1 (LEAP-1) and LEAP-2 mRNA expression; (2) the relative mRNA expression of interleukin 10, transforming growth factor β1, inhibitor factor κBα (IκBα) and target of rapamycin (TOR); (3) the activities of anti-superoxide anion (ASA), anti-hydroxyl radical (AHR), copper/zinc superoxide dismutase (SOD1), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR), glutathione content and mRNA levels of SOD1, CAT, GPx, GR and NF-E2-related factor 2 (Nrf2) genes; (4) the transcription abundance of occludin, claudin b, claudin c, claudin 12 and zonula occludens 1 genes. At the same time, appropriate PL supplementation decreased (P < 0.05): (1) tumor necrosis factor α, interleukin 1β, nuclear factor κB p65 (NF-κB p65), IκB kinase β (IKKβ) and IκB kinase γ (IKKγ) mRNA expression; (2) malondialdehyde (MDA), protein carbonyl (PC) and reactive oxygen species (ROS) content and the relative mRNA expression of Kelch-like-ECH-associated protein 1a (Keap1a) and Keap1b; (3) the transcription abundance of myosin light chain kinase (MLCK) and p38 mitogen-activated protein kinase (p38 MAPK) genes. In conclusion, the positive effect of PL on gill health is associated with the improvement of the immunity, antioxidant status and tight junction barrier of fish gills. Finally, based on ACP activity, C3 content, PC content and ASA activity in the gills, the optimal dietary PL level for juvenile grass carp (9.34-87.50 g) was estimated to be 3.62%, 4.30%, 3.91% and 3.86%, respectively.

Exogenous phospholipids supplementation improves growth and modulates immune response and physical barrier referring to NF-κB, TOR, MLCK and Nrf2 signaling factors in the intestine of juvenile grass carp (Ctenopharyngodon idella)

This study was conducted to investigate the effects of dietary phospholipids (PL) on the growth performance, intestinal enzyme activity and immune response and intestinal physical barrier of juvenile grass carp (Ctenopharyngodon idella). A total of 1080 juvenile grass carp with an average initial weight of 9.34 ± 0.03 g were fed six semi-purified diets containing 0.40% (unsupplemented control group), 1.43%, 2.38%, 3.29%, 4.37% and 5.42% PL for 2 months. Results indicated that 3.29% PL increased lysozyme (LZ) and acid phosphatase (ACP) activities and complement component 3 (C3) content (P < 0.05), up-regulated the mRNA relative expression levels of interleukin 10, transforming growth factor β1 (TGF-β1), inhibitor protein κBα (IκBα), target of rapamycin (TOR) and casein kinase 2 (CK2) (P < 0.05), and down-regulated tumor necrosis factor α (TNF-α), interleukin 1β, nuclear factor κB p65 (NF-κB p65), IκB kinase β (IKKβ) and IκB kinase γ (IKKγ) mRNA relative expression levels (P < 0.05) in the intestine, suggesting that optimum PL could improve fish intestinal immunity. In addition, 3.29% PL increased the activities of anti-superoxide anion (ASA), anti-hydroxyl radical, copper/zinc superoxide dismutase (SOD1), glutathione peroxidase (GPx) and glutathione reductase (GR), the content of glutathione (P < 0.05), and the mRNA relative expression levels of occludin, zonula occludens 1 (ZO-1), claudin 3, claudin 12, claudin b, claudin c, SOD1, GPx, GR and NF-E2-related factor 2 (Nrf2) and decreased malondialdehyde (MDA), protein carbonyl (PC) and ROS content (P < 0.05), the mRNA relative expression levels of Kelch-like-ECH-associated protein 1a (Keap1a), myosin light chain kinase (MLCK) and p38 mitogen-activated protein kinase (p38 MAPK) in the intestine, indicating that the optimum PL could improve fish intestinal physical barrier. Finally, based on the PWG, C3 content in the DI, ACP activity in the DI, intestinal PC content and intestinal ASA activity, the optimal dietary PL levels for juvenile grass carp (9.34-87.50 g) were estimated to be 3.46%, 3.79%, 3.93%, 3.72%, and 4.12%, respectively.

Evaluation the effect of thiamin deficiency on intestinal immunity of young grass carp (Ctenopharyngodon idella)

Our study explored the effect of dietary thiamin on growth and immunity (intestine, head kidney, spleen and liver) of young grass carp (Ctenopharyngodon idella). Fish were fed diets containing six graded levels of thiamin at 0.12-2.04 mg/kg diet for 8 weeks. The percentage weight gain (PWG), feed intake and feed efficiency were lower in fish fed the 0.12 mg/kg diet. Thiamin deficiency decreased complement 3 content, lysozyme (LA) and acid phosphatase activities, mRNA levels of hepcidin and interleukin (IL) 10, elevated mRNA levels of interferon γ2, tumor necrosis factor α, IL-1β and IL-8 in intestine, head kidney, spleen and liver. The mRNA levels of inhibitor protein-κBα, target of rapamycin (TOR) and NF-E2-related factor 2 (Nrf2), the activities and mRNA levels of copper/zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase were down-regulated, mRNA levels of myosin light-chain kinase (MLCK), IκB kinases (IKKβ and IKKγ), nuclear factor κB P65 (NF-κB P65) and Kelch-like-ECH-associated protein 1a (Keap1a) were up-regulated in the intestine of fish fed the thiamin-deficient diet. Additionally, thiamin deficiency decreased claudin b, c and 3, ZO-1 and occludin mRNA levels in each intestinal segment, increased claudin 12 and claudin 15a mRNA levels in distal intestine. In conclusion, thiamin deficiency decreased fish growth and immunity of intestine, head kidney, spleen and liver. The dietary thiamin requirement of young grass carp (242-742 g) based on intestinal LA activity or PWG were determined to be 1.15 or 0.90 mg/kg diet, respectively.

Dietary pantothenic acid deficiency and excess depress the growth, intestinal mucosal immune and physical functions by regulating NF-κB, TOR, Nrf2 and MLCK signaling pathways in grass carp (Ctenopharyngodon idella)

This study investigated the effects of dietary pantothenic acid (PA) on the growth, intestinal mucosal immune and physical barrier, and relative mRNA levels of signaling molecules in the intestine of grass carp (Ctenopharyngodon idella). A total of 540 grass carp (253.44 ± 0.69 g) were fed six diets with graded levels of PA (PA1, PA15, PA30, PA45, PA60 and PA75 diets) for 8 weeks. The results indicated that compared with PA deficiency (PA1 diet) and excess (PA75 diet) groups, optimal PA supplementation increased (P < 0.05): (1) percent weight gain (PWG), feed intake and feed efficiency; (2) lysozyme activity, complement 3 content, liver-expressed antimicrobial peptide 2 and hepcidin, interleukin 10, transforming growth factor β1 and inhibitor of κBα mRNA levels in some intestinal segments; (3) activities and mRNA levels of copper/zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferases and glutathione reductase, and NF-E2-related factor 2 (Nrf2) mRNA level in the whole intestine; (4) Claudin b, Claudin 3, Claudin c, Occludin and ZO-1 mRNA levels in some intestinal segments of grass carp. Conversely, optimal PA supplementation decreased (P < 0.05): (1) tumor necrosis factor α, interleukin 1β, interferon γ2, interleukin 8, nuclear factor κB P65 (NF-κB P65), IκB kinase α, IκB kinase β, IκB kinase γ and target of rapamycin (TOR) mRNA expression levels in some intestinal segments; (2) reactive oxygen species, malondialdehyde and protein carbonyl contents, and Kelch-like ECH-associating protein 1a, Kelch-like ECH-associating protein 1b in the intestine; (3) Claudin 12, Claudin 15a and myosin light-chain kinase (MLCK) mRNA levels in some intestinal segments of grass carp. In conclusion, optimum PA promoted growth, intestinal mucosal immune and physical function, as well as regulated mRNA levels of signaling molecules NF-κB P65, TOR, Nrf2 and MLCK in grass carp intestine. Based on the quadratic regression analysis of PWG and intestinal lysozyme activity, the optimal PA levels in grass carp (253.44-745.25 g) were estimated to be 37.73 mg/kg and 41.38 mg/kg diet, respectively.

Effects of Choline on Meat Quality and Intramuscular Fat in Intrauterine Growth Retardation Pigs

The aim of this study was to investigate the effects of choline supplementation on intramuscular fat (IMF) and lipid oxidation in IUGR pigs. Twelve normal body weight (NBW) and twelve intrauterine growth retardation (IUGR) newborn piglets were collected and distributed into 4 treatments (Normal: N, Normal+Choline: N+C, IUGR: I, and IUGR+Choline: I+C) with 6 piglets in each treatment. At 23 d of age, NBW and IUGR pigs were fed basal or choline supplemented diets. The results showed that the IUGR pigs had significantly lower (P<0.05) BW as compared with the NBW pigs at 23 d, 73 d, and 120 d of age, however, there was a slight decreased (P>0.05) in BW of IUGR pigs than the NBW pigs at 200 d. Compared with the NBW pigs, pH of meat longissimus dorsi muscle was significantly lower (P<0.05), and the meat color was improved in IUGR pigs. The malondialdehyde (MDA) levels were significantly decreased (P<0.05), while triglyceride (TG) and IMF contents were significantly higher (P<0.05) in the IUGR pigs than the NBW pigs. IUGR up-regulated the mRNA gene expression of fatty acid synthetase (FAS) and acetyl-CoA carboxylase (ACC). Dietary choline significantly increased (P<0.05) the BW at 120d of age, however, significantly decreased (P<0.05) the TG and IMF contents in both IUGR and NBW pigs. FAS and sterol regulatory element-binding proteins 1 (SREBP1) mRNA gene expressions were increased (P<0.05) while the muscle-carnitine palmityl transferase (M-CPT) and peroxisome proliferators-activated receptorγ (PPARγ) mRNA (P<0.05) gene expressions were decreased in the muscles of the IUGR pigs by choline supplementation. Furthermore, choline supplementation significantly increased (P<0.05) the MDA content as well as the O2•¯ scavenging activity in meat of IUGR pigs. The results suggested that IUGR pigs showed a permanent stunting effect on the growth performance, increased fat deposition and oxidative stress in muscles. However, dietary supplementation of choline improved the fat deposition via enhancing the lipogenesis and reducing the lipolysis.

Effect of dietary glutamine on growth performance, non-specific immunity, expression of cytokine genes, phosphorylation of target of rapamycin (TOR), and anti-oxidative system in spleen and head kidney of Jian carp (Cyprinus carpio var. Jian)

This study was designed to investigate the effects of dietary glutamine on the growth performance, cytokines, target of rapamycin (TOR), and antioxidant-related parameters in the spleen and head kidney of juvenile Jian carp (Cyprinus carpio var. Jian). Fish were fed the basal (control) and glutamine-supplemented (12.0 g glutamine kg(-1) diet) diets for 6 weeks. Results indicated that the dietary glutamine supplementation improved the growth performance, spleen protein content, serum complement 3 content, and lysozyme activity in fish. In the spleen, glutamine down-regulated the expression of the interleukin 1 and interleukin 10 genes, and increased the level of phosphorylation of TOR protein. In the head kidney, glutamine down-regulated the tumor necrosis factor α and interleukin 10 gene expressions, phosphorylated and total TOR protein levels, while up-regulated the transforming growth factor β2 gene expression. Furthermore, the protein carbonyl content was decreased in the spleen of fish fed glutamine-supplemented diet; conversely, the anti-hydroxyl radical capacity and glutathione content in the spleen were increased by glutamine. However, diet supplemented with glutamine did not affect the lipid peroxidation, anti-superoxide anion capacity, and antioxidant enzyme activities in the spleen. Moreover, all of these antioxidant parameters in the head kidney were not affected by glutamine. Results from the present experiment showed the importance of dietary supplementation of glutamine in benefaction of the growth performance and several components of the innate immune system, and the deferential role in cytokine gene expression, TOR kinase activity, and antioxidant status between the spleen and head kidney of juvenile Jian carp.

Dietary tryptophan modulates intestinal immune response, barrier function, antioxidant status and gene expression of TOR and Nrf2 in young grass carp (Ctenopharyngodon idella)

The present research evaluated the effects of dietary tryptophan (Trp) on growth performance, intestinal mucosal immune, barrier function and antioxidant capacity and gene expression of young grass carp (Ctenopharyngodon idella). Fish were fed six different experimental diets containing graded levels of Trp at 0.7(control), 1.7, 3.1, 4.0, 5.2 and 6.1 g kg(-1) diet for 8 weeks. The results showed that Trp supplementation significantly enhanced the percent weight gain (PWG), feed intake and feed efficiency (P < 0.05), and decreased the plasma ammonia content (PAC) (P < 0.05). After the 8-week feeding trail, an environmental copper exposure trail was conducted for 4 days. Results from the copper exposure trail showed that dietary Trp enhanced the lysozyme, acid phosphatase activities and complement 3 contents in the intestine of young grass carp (P < 0.05). In addition, Trp supplementation increased the copper/zinc superoxide dismutase (SOD1), glutathione peroxidase (GPx) activities and glutathione contents (P < 0.05), and decreased the protein carbonyl and malondialdehyde contents (P < 0.05). Furthermore, the relative gene expression levels of interleukin 10, transforming growth factor-β1, occludin, zonula occludens 1, claudin-b, -c, and -3, SOD1, GPx and NF-E2-related factor 2 in the intestine were significantly up-regulated with increasing of dietary Trp up to a certain level (P < 0.05). Conversely, the mRNA levels of tumor necrosis factor α, interleukin 8, target of rapamycin, Kelch-like-ECH-associated protein 1, claudin-12 and -15a in the intestine were significantly down-regulated by Trp (P < 0.05). Collectively, appropriate dietary Trp level improves fish growth, intestinal immune response, barrier function and antioxidant status, and regulated the mRNA levels of related signal molecules of young grass carp. Based on the quadratic regression analysis of the PWG and PAC, the dietary Trp requirement of young grass carp (287-699 g) was estimated to be 3.81 g kg(-1) diet (12.7 g kg(-1) protein) and 3.89 g kg(-1) diet (13.0 g kg(-1) protein), respectively.

The impaired intestinal mucosal immune system by valine deficiency for young grass carp (Ctenopharyngodon idella) is associated with decreasing immune status and regulating tight junction proteins transcript abundance in the intestine

This study investigated the effects of dietary valine on the growth, intestinal immune response, tight junction proteins transcript abundance and gene expression of immune-related signaling molecules in the intestine of young grass carp (Ctenopharyngodon idella). Six iso-nitrogenous diets containing graded levels of valine (4.3-19.1 g kg(-)(1) diet) were fed to the fish for 8 weeks. The results showed that percentage weight gain (PWG), feed intake and feed efficiency of fish were the lowest in fish fed the valine-deficient diet (P < 0.05). In addition, valine deficiency decreased lysozyme, acid phosphatase activities and complement 3 content in the intestine (P < 0.05), down-regulated mRNA levels of interleukin 10, transforming growth factor β1, IκBα and target of rapamycin (TOR) (P < 0.05), and up-regulated tumor necrosis factor α, interleukin 8 and nuclear factor κB P65 (NF-κB P65) gene expression (P < 0.05). Additionally, valine deficiency significantly decreased transcript of Occludin, Claudin b, Claudin c, Claudin 3, and ZO-1 (P < 0.05), and improved Claudin 15 expression in the fish intestine (P < 0.05). However, valine did not have a significant effect on expression of Claudin 12 in the intestine of grass carp (P > 0.05). In conclusion, valine deficiency decreased fish growth and intestinal immune status, as well as regulated gene expression of tight junction proteins, NF-κB P65, IκBα and TOR in the fish intestine. Based on the quadratic regression analysis of lysozyme activity or PWG, the dietary valine requirement of young grass carp (268-679 g) were established to be 14.47 g kg(-1) diet (4.82 g 100 g(-1) CP) or 14.00 g kg(-1) diet (4.77 g 100 g(-1) CP), respectively.

Effect of choline on antioxidant defenses and gene expressions of Nrf2 signaling molecule in the spleen and head kidney of juvenile Jian carp (Cyprinus carpio var. Jian)

The present work evaluates the effects of various levels of dietary choline on antioxidant defenses and gene expressions of Nrf2 signaling molecule in spleen and head kidney of juvenile Jian carp (Cyprinus carpio var. Jian). Fish were fed with six different experimental diets containing graded levels of choline at 165 (choline-deficient control), 310, 607, 896, 1167 and 1820 mg kg(-1) diet for 65 days. At the end of the feeding trail, fish were challenged with Aeromonas hydrophila and mortalities were recorded over 17 days. Dietary choline significantly decreased malondialdehyde and protein carbonyl contents in spleen and head kidney. However, anti-superoxide anion and anti-hydroxyl radical activities in spleen and head kidney also decreased. Interestingly, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR) in spleen, GPx activity in head kidney, and glutathione contents in spleen and head kidney were decreased with increase of dietary choline levels up to a certain point, whereas, activities of SOD, GST and GR in head kidney showed no significantly differences among groups. Similarly, expression levels of CuZnSOD, MnSOD, CAT, GPx1a, GPx1b and GR gene in spleen and head kidney were significantly lower in group with choline level of 607 mg kg(-1) diet than those in the choline-deficient group. The relative gene expressions of Nrf2 in head kidney and Keap1a in spleen and head kidney were decreased with increasing of dietary choline up to a certain point. However, the relative gene expression of Nrf2 in spleen were not significantly affected by dietary choline. In conclusion, dietary choline decreased the oxidant damage and regulated the antioxidant system in immune organs of juvenile Jian carp.