Effects of dietary leucine and valine levels on growth performance, glycolipid metabolism and immune response in Tilapia GIFT Oreochromis niloticus.

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 IL1ß 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, IL1ß, 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, IL1ß 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.

Interactions between dietary carbohydrate and thiamine: implications on the growth performance and intestinal mitochondrial biogenesis and function of Megalobrama amblycephala.

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-1ß protein expression as well as the transcriptions of AMPKα1, AMPKα2, PGC-1ß, 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-1ß protein expression as well as the transcriptions of AMPKα1, AMPKα2, PGC-1ß, 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-1ß protein expression as well as the transcriptions of AMPKα1, AMPKα2, PGC-1ß, 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.

Molecular characterization of thioredoxin-interacting protein (TXNIP) from Megalobrama amblycephala and its potential roles in high glucose-induced inflammatory response.

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-1ß and il-6 expression in hepatocytes, and its knockdown led to remarkably reduced il-1ß 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-1ß.