A12-week experiment was conducted to evaluate the influences of thiamine ongrowth performance, and intestinal mitochondrial biogenesis and function of Megalobramaamblycephala fed a high-carbohydrate ...(HC) diet. Fish (24·73 (sem 0·45) g) were randomly assigned to one of four diets: two carbohydrate (CHO) levels (30 and 45 %) and two thiamine levels (0 and 1·5 mg/kg). HC diets significantly decreased DGC, GRMBW, FIMBW, intestinal activities of amylase, lipase, Na+, K+-ATPase, CK, complexes I, III and IV, intestinal ML, number of mitochondrial per field, ΔΨm, the P-AMPK: T-AMPK ratio, PGC-1β protein expression as well as the transcriptions of AMPKα1, AMPKα2, PGC-1β, mitochondrial transcription factor A, Opa-1, ND-1 and COX-1 and 2, while the opposite was true for ATP, AMP and reactive oxygen species, and the transcriptions of dynamin-related protein-1, fission-1 and mitochondrial fission factor. Dietarythiamine concentrations significantly increased DGC, GRMBW, intestinal activities of amylase, Na+, K+-ATPase, CK, complexes I and IV, intestinal ML, number of mitochondrial per field, ΔΨm, the P-AMPK:T-AMPK ratio, PGC-1β protein expression as well as the transcriptions of AMPKα1, AMPKα2, PGC-1β, Opa-1, ND-1, COX-1 and 2, SGLT-1 and GLUT-2. Furthermore, a significant interaction between dietary CHO and thiamine was observed in DGC, GRMBW, intestinal activities of amylase, CK, complexes I and IV, ΔΨm, the AMP:ATP ratio, the P-AMPK:T-AMPK ratio, PGC-1β protein expression as well as the transcriptions of AMPKα1, AMPKα2, PGC-1β, Opa-1, COX-1 and 2, SGLT-1 and GLUT-2. Overall, thiamine supplementation improved growth performance, and intestinal mitochondrial biogenesis and function of M. amblycephala fed HC diets.
In order to investigate the dietary requirement of Trachinotus ovatus for vitamin E (VE) and its effects on tissue polyunsaturated fatty acids (PUFA) reservation, a 56‐day feeding trial was performed ...with five diets (D1–D5) supplemented with different levels of VE at 34.56, 47.35, 61.16, 91.06 and 144.88 mg VE/kg diet. A total of 375 fish (initial weight 13.40 ± 0.08 g) were randomly distributed equally into 15 sea cages and each diet in triplicate cages. After 8 weeks of feeding, fish fed diet D3 exhibited significantly higher weight gain (WG), serum superoxide dismutase and glutathione peroxidase activities and also had higher docosahexaenoic acid (DHA) and n‐3 PUFA contents in the raw muscle than those of fish fed diets D1 and D5 (p < .05). Moreover, n‐6 PUFA and n‐3 PUFA contents in cooked muscle of D3 and D4 groups were significantly higher than those of other groups (p < .05). Besides, the contents of hepatic arachidonic acids, eicosapentaenoic acid, DHA, n‐6 PUFA and n‐3 PUFA in fish of D3 and D4 groups were also significantly higher than those of D1 group (p < .05). Correspondingly, the transcript levels of genes related to PUFA β‐oxidation (cpt1 and pparα) and synthesis (fas and elovl5) were lower in D3 and D4 groups. Based on regression analysis for WG, the optimum dietary VE level was 90.75 mg/kg, which was consistent with the above results that fish fed diets D3 and D4 displayed better growth performance, antioxidant capacity and muscle PUFA stability, where the last suggesting an effect of dietary VE against PUFA β‐oxidation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The study was performed to evaluate the effects of the reduced lactate production by sodium oxamate (SO) on growth performance, lactate and glucose and lipid metabolism, and glucose tolerance of
fed ...high-carbohydrate (CHO) diets. In in vitro study, primary hepatocytes were incubated for 48 h in a control medium (5.5 mM glucose), a high-glucose medium (25 mM glucose, HG), or a SO-containing high-glucose medium (25 mM glucose + 50 mM SO, HG-SO). Results indicated lactate and triglyceride (TG) levels, and lactate dehydrogenase a (LDH-a) expression in the HG-SO group were remarkably lower than those of the HG group. In in vivo study,
(5.23 ± 0.03 g) were fed four diets containing a control diet (10% CHO, C) and three SO contents 0 (HC), 100 (HC-SO1), and 200 (HC-SO2) mg·kg
, respectively of high-CHO diets (20% CHO) for 11 wk. High-CHO diets significantly reduced weight gain rate (WGR), specific growth rate (SGR), p-AMPK-to-t-AMPK ratio, and expression of insulin receptor substrate 1 (IRS1), insulin-like growth factor I (IGF-I), insulin-like growth factor I receptor (IGF-IR), fructose-1,6-biphosphatase (FBPase), peroxisome proliferator-activated receptor α (PPARα), and carnitine palmitoyl transferase 1α (CPT1α) compared with the C group, whereas the opposite was true for plasma levels of glucose, TG, lactate, tissue glycogen, and lipid contents, and expression of LDH-a, monocarboxylate transporter 1 and 4 (MCT1 and MCT4), insulin, glucokinase (GK), pyruvate dehydrogenase E1 subunit (PDH), sterol-regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS). The HC-SO2 diets remarkably increased WGR, SGR, p-AMPK-to-t-AMPK ratio, and expression of IRS1, IGF-I, IGF-IR, GK, PDHα, PDHβ, FAS, acetyl-CoA carboxylase 1 (ACC1), PPARα, and CPT1α compared with the HC group. Besides, HC-SO2 diets also enhanced glucose tolerance of fish after a glucose loading. Overall, the reduced lactate production by SO benefits growth performance and glucose homeostasis of high-CHO-fed
through the enhancement of glycolysis, lipogenesis, and fatty acid β-oxidation coupled with the suppression of glycogenesis and gluconeogenesis.
This study aimed to characterize the full-length cDNA of thioredoxin-interacting protein (TXNIP) from Megalobrama amblycephala, and investigate its roles in high glucose (HC)-induced inflammatory ...response. The cDNA obtained covered 2706-bp with an open reading frame of 1203-bp encoding 400 amino acids, compared to Cyprinus carpio, it showed 89.96% homology. The highest expression of txnip was observed in head kidney followed by spleen and liver. After a 12-week feeding trial, high-carbohydrate diet remarkably increased txnip expression in liver and white muscle. Glucose administration resulted in a remarkably increased liver txnip expression, which peaked at 1 h. Thereafter, the expression decreased remarkably to the basal value at 12 h. However, insulin injection resulted in a significant decrease in txnip expression with minimum values attained at 2 h. Subsequently, it gradually increased to the normal values. Moreover, in the in-vitro study, over-expression of txnip along with remarkably increased il-1β and il-6 expression in hepatocytes, and its knockdown led to remarkably reduced il-1β expression. Furthermore, metformin treatment remarkably increased the cell viability and trx expression of hepatocytes under high glucose, while the opposite was true for ROS levels, LDH activity, the ALT/AST ratio, Txnip protein content and the transcriptions of txnip, tnfα and il-1β.
•The txnip gene was characterized in an herbivorous fish M. amblycephala.•It shares a high degree of conservation among most fish and higher vertebrates.•Long-term feeding of high-carbohydrate diets increased txnip expression in liver and white muscle.•Glucose load led to a prompt increase of liver txnip expression, whereas the opposite was true after the insulin load.•Metformin alleviated high-glucose induced inflammation in the hepatocytes by TXNIP inhibition.
A 12-week feeding trial was performed to evaluate the effects of high-carbohydrate diet on oxidative stress, inflammation and apoptosis induced by silver nanoparticles (Ag-NPs) in M. amblycephala. ...Fish (20.12 ± 0.85 g) were randomly fed four diets (one control diet (C, 30% carbohydrate), one control diet supplemented with 100 mg kg−1 Ag-NPs (CS), one high-carbohydrate diet (HC, 45% carbohydrate) and one HC diet supplemented with 100 mg kg−1 Ag-NPs (HCS)). The results indicated that weight gain rate (WGR), specific growth rate (SGR), antioxidant enzyme (SOD and CAT) activities and expression of Trx, Cu/Zn-SOD, Mn-SOD, CAT and GPx1 of fish fed CS diet were all remarkably lower than those of other groups, whereas the opposite was true for plasma IL 1β and IL 6 levels, liver ROS contents, hepatocytes apoptotic rate, AMP/ATP ratio, AMPKα, P 53 and caspase 3 protein contents and mRNA levels of AMPKα 1, AMPKα 2, TXNIP, NF-κB, TNFα, IL 1β, IL 6, P 53, Bax and caspase 3. However, high-carbohydrate diet remarkably increased WGR, SGR, liver SOD and CAT activities, AMPKα protein content and mRNA levels of antioxidant genes (Cu/Zn-SOD, Mn-SOD, CAT and GPx1), anti-inflammatory cytokines (IL 10) and anti-apoptotic genes (Bcl 2) of fish facing Ag-NPs compared with the CS group, while the opposite was true for liver ROS contents, hepatocytes apoptotic rate, P 53 and caspase 3 protein contents, as well as mRNA levels of TXNIP, NF-κB, TNFα, IL 1β, IL 6, P 53, Bax and caspase 3. Overall, high-carbohydrate diet could attenuate Ag-NPs-induced hepatic oxidative stress, inflammation and apoptosis of M. amblycephala through AMPK activation.
To explore the mechanism of fatty liver formation induced by high non‐protein energy diets in grass carp (Ctenopharyngodon idella), basal diet and high‐energy diets were fed to juvenile grass carp ...for 9 weeks. The experimental groups fed on high‐energy diets which included a high‐lipid diet (H‐LIP), a high‐carbohydrate diet (H‐CHO) and a high‐lipid and carbohydrate diet (H‐CL). The control group fed on basal diet. Growth performance, liver fat accumulation, serum biochemical indexes and the expression levels of lipid metabolism‐related genes (SREBP‐1, PPARγ, FAS, ACC1, and LPL) and miRNAs (miR‐33, miR‐122, and miR‐370) were examined at the end of the feeding trial. There were no significant differences in growth rate and feed efficiency among the four groups. However, significant increase in mesenteric and liver fat contents, and lipid droplets in the liver was induced by high‐lipid and high‐carbohydrate diets. There were significant differences in serum biochemical indicators such as AST/ALT, GLB, TG and TP, and liver fatty acid composition between the control and experimental groups. The expression levels of SREBP‐1, PPARγ, FAS, ACC1 and LPL were upregulated, while CPT‐1 was downregulated with the high‐energy treatments. Additionally, the expression levels of miR‐33, miR‐122 and miR‐370 in the liver were higher in the three high‐energy treatments than those in the control (P < 0.05). The results suggest that modifications of lipid metabolism‐related genes and miRNAs may be involved in fatty liver formation induced by high non‐protein energy diets in grass carp.
An 8-week feeding trial was performed to evaluate the effects of dietary leucine (Leu) and valine (Val) levels on growth performance, glycolipid metabolism and immune response in Oreochromis ...niloticus. Fish (15.23 ± 0.05 g) were randomly fed four diets containing two Leu levels (1.2% and 2.3%) and two Val levels (0.7% and 1.4%) as a 2 × 2 experimental design (LL-LV, LL-HV, HL-LV and HL-HV). Compared with LL-LV group, the growth parameters (final weight, daily growth coefficient (DGC) and growth rate per metabolic body weight (GRMBW)), feed conversion rate (FCR), the activities of intestinal amylase, lipase, creatine kinase (CK) and Na+, K+-ATPase, liver NAD+/NADH ratio, as well as the expression of SIRT1, GK, PK, FBPase, PPARα, CPT IA, ACO and IL10 all increased significantly in the HL-LV group; however, in the high Val group, final weight, DGC, GRMBW, intestinal enzyme activities, as well as the expression of PEPCK, SREBP1, FAS, IL8 and IL10 of the HL-HV group were significantly lower than those of the LL-HV group, while the opposite was true for the remaining indicators. Significant interactions between dietary Leu and Val were observed in final weight, DGC, GRMBW, plasma IL1β and IL6 levels, intestinal amylase and CK activities, liver NAD+/NADH ratio, as well as the expression of SIRT1, PK, PEPCK, FBPase, SREBP1, FAS, PPARα, CPT IA, ACO, NF-κB1, IL1β, IL6 and IL10. The highest values of growth parameters, intestinal enzyme activities and expression of SIRT1, FBPase, PPARα, CPT IA and ACO were observed in the HL-LV group, while the opposite was true for the expression of SREBP1, FAS, PPARα, NF-κB1, IL1β and IL6. Overall, our findings indicated that dietary Leu and Val can effect interactively, and fish fed with diets containing 2.3% Leu with 0.7% Val had the best growth performance and hepatic health status of O. niloticus.
•The interactive effects of valine and leucine were estimated on Oreochromis niloticus.•Growth performance of O. niloticus was significantly depressed by an excess of dietary leucine and valine.•Excess dietary leucine and valine induced liver inflammation of O. niloticus.•Dietary 2.3% Leu + 0.7% Val level improved growth performance and inhibited liver inflammation by SIRT1 activation.
Epithelial brush-border membrane vesicles (BBMVs) were isolated from the intestine of common carp and studied systematically by enzyme activity, transmission electron microscopy and immunoblotting. ...The uptake time course and the substrate concentration effect were assessed, and then, the ability of phlorizin and cytochalasin B to inhibit uptake was analyzed. The results show that sucrase, alkaline phosphatase and Na+-K+-ATPase activities in these vesicles were enriched 7.94-, 6.74- and 0.42-fold, respectively, indicating a relatively pure preparation of apical membrane with little basolateral contamination. The vesicular structure was in complete closure, as confirmed by electron microscopy. The presence of SGLT1 on the BBMVs was confirmed by Western blot analysis. In the time course experiment, the glucose uptake by BBMVs in Na+ medium displayed an initial accumulation (overshoot) at 5 min followed by a rapid return to equilibrium values at 60 min. Over the 2-NBDG concentration range selected, the external 2-NBDG concentration in NaSCN medium graphed as a curved line. Phlorizin and cytochalasin B had an obvious inhibitory effect on 2-NBDG transport in carp BBMVs, and the detected fluorescence intensity decreased. The inhibition rate in the 1000 μM group was the strongest at 64.18% and 63.61% of phlorizin and cytochalasin B, respectively, indicating the presence of carriers other than SGLT1. This study is the first to demonstrate that 2-NBDG can be used as a convenient and sensitive probe to detect glucose uptake in fish BBMVs. This technology will provide a convenient method to discover new effects and factors in glucose metabolism.
This study was conducted to investigate the effects of magnesium (Mg) supplementation on the growth performance, muscle fiber development and flesh quality of Megalobrama amblycephala fed a ...high-carbohydrate (CHO) diet. In vivo, six experimental diets, a control diet (30% CHO, C), and five Mg supplementation levels (0 (HC1), 200 (HC2), 400 (HC3), 800 (HC4) and 1200 (HC5) mg kg−1, respectively) of high-CHO diet (45% CHO), were formulated and then fed to M. amblycephala (initial weight 43.15 ± 0.43 g) for 13 weeks. Results showed that the HC1 diets remarkably decreased weight gain rate (WGR), specific growth rate (SGR), water holding capacity (WHC), pH 24 h postmortem, collagen content, textural properties (hardness, tenderness, chewiness and resilience), muscle fiber density, succinate dehydrogenase (SDH) and malate dehydrogenase (MDH) activities, as well as transcriptions of ampkα2, pgc-1α, mrf-4, myf-5 and myf-6 compared with the C group, but muscle AMP/ATP ratio, ATPase activities and mstna and mstnb transcription showed an opposite trend. The HC3 group of fish obtained relatively high values of WGR, SGR, muscle lipid and protein content, collagen content, textural properties (hardness, tenderness, chewiness and resilience), fiber density, SDH and MDH activities, AMP/ATP ratio as well as transcriptions of ampkα1, pgc-1α, myod, myog and myf-5 compared with other HC groups. In vitro, the isolated primary hepatocytes from M. amblycephala were assigned into four experimental groups: a control group (5.5 mM glucose, Control), a high glucose group (30 mM glucose, HG), an AICAR group (30 mM glucose + 250 μM AICAR, HGA) and an MgSO4 group (30 mM glucose + 2 mM MgSO4, HGM). Results showed that MgSO4 treatment remarkably increased p-Ampk/t-Ampk ratio, Pgc-1α protein content and transcriptions of ampkα1, ampkα2 and pgc-1α compared with the HG group. Overall, based on regression analysis for SGR, the optimal Mg level of M. amblycephala fed high-CHO diets was 366.67 mg kg-1, which was consistent with the above results that fish fed HC3 diets displayed higher the growth performance, muscle fiber density and flesh quality of M. amblycephala.
•High-carbohydrate (CHO) reduced muscle water holding capacity, pH, hardness and promoted muscle fiber hypertrophy.•Magnesium improved the nutritional value and flesh quality of fish fed high-CHO diets.•Magnesium improved the myofibers characteristics (density and type) of fish fed high-CHO diets.•Magnesium activated the AMPK/PGC-1α pathway in muscle of fish fed high-CHO diets.•Optimal Mg supplementation level for juvenile M. amblycephala fed high-CHO diets was 366.67 mg kg-1.
The nucleotide-binding domain, leucine-rich repeat and pyrin domain containing protein 3 (NLRP3) has emerged as a key regulator of glucose homeostasis in mammals, while relevant information are still ...poorly interpreted in aquatic animals. Herein, we cloned and characterized NLRP3 gene from Megalobrama amblycephala, and analyzed its function in high glucose (HG)-induced inflammation. Full-length cDNA of NLRP3 measured 4380 bp with 3570 bp open reading frame encoding 1189 amino acids, compared with Pimephales promelas, it displayed 90.3% homology. Structural analysis revealed that M. amblycephala NLRP3 processed characteristic domains of pyrin, FISNA, NACHT, CARD and LRRs. Spatial expression analysis displayed NLRP3 was ubiquitously expressed in eight organs/tissues (gill, liver, spleen, intestine, head kidney, white muscle, heart and brain) with largest magnitude in head kidney. After a 13-week nutritional experiment, carbohydrate-enriched (45%) diets significantly upregulated NLRP3 mRNA levels in the liver and white muscle than that of the control (30%) diets. Glucose loading caused a significantly increased NLRP3 mRNA levels in the white muscle and liver, with maximum values got at 1 and 2 h, respectively. Subsequently, the mRNA levels rapidly returned to the basal level at 12 h. As for the in-vitro experiments, both ATP and high-glucose treatments remarkably increased the expression of NLRP3 and pro-inflammatory cytokines (IL1β and IL6) in hepatocytes. Additionally, high-leucine (30 mM) levels remarkably increased NLRP3 protein content and transcriptions of NLRP3, NF-κB, IL1β and IL6 than those of the HG and HG + low leucine (10 mM) treatment groups, while the opposite was true for IL8 and IL10. Overall, our findings indicated that M. amblycephala NLRP3 is highly conserved compared with other vertebrates. NLRP3 participated in the control of HG-induced inflammation, and high-leucine levels could aggravate HG-induced inflammation in hepatocytes of M. amblycephala via NLRP3 activation.
•The NLRP3 gene was characterized in an herbivorous fish Megalobrama amblycephala.•It shares a high degree of conservation among most fish.•Long-term feeding of carbohydrate-enriched diets increased NLRP3 expression in the liver and muscle.•Glucose load led to a prompt increase of NLRP3 expression in the liver and white muscle during the first 2 h.•Leucine has a dose-dependent effect on the regulation of high glucose-induced inflammation in hepatocytes.
PDF
