Feeding Faba Beans (Vicia faba L.) Reduces Myocyte Metabolic Activity in Grass Carp (Ctenopharyngodon idellus)

Abstract

In this study, we aimed to explore the effects of faba bean (Vicia faba L.) on the energy metabolism of grass carp (Ctenopharyngodon idellus). A total of 180 fish (∼2900 g) were randomly assigned to six tanks (2.5 × 2.5 × 1.2 m; 30 individuals per tank) and fed either faba bean (Vicia faba L.) or a commercial diet for 120 days (3% body weight, twice per day). The results showed that faba bean-fed grass carp (FBFG) had significantly lower growth and higher fat accumulation in the mesenteric adipose tissue and hepatopancreas than commercial diet-fed grass carp (CDFG). Compared with CDFG, FBFG exhibited no significant difference in proximate composition of the muscle; however, an obvious decrease in muscle fiber size and significantly higher hardness, chewiness, and gumminess were observed. Transcriptome results showed that a total of 197 genes were differentially regulated in the dorsal muscle. Down-regulated genes included four genes annotated with myocyte development and 12 transcripts annotated with components of myofibrils. In addition, the FBFG group exhibited significantly lower expression of genes associated with oxygen transport, the mitochondrial respiratory chain, and creatine metabolism, suggesting reduced energy availability in the muscle of the FBFG. Moreover, using western-blotting and enzyme assays, we found decreased protein levels in the mitochondrial electron transport respiratory chain and creatine metabolism activities, as well as increased expression of autophagy marker protein levels, in the muscle of FBFG. Overall, our results suggest that an abnormal energy distribution may exist in grass carps after feeding with faba bean, which is reflected by a mass of fat deposition in the adipose tissue and hepatopancreas and subdued metabolic activity in the muscle.

Dietary Creatine Reduces Lipid Accumulation by Improving Lipid Catabolism in the Herbivorous Grass Carp, Ctenopharyngodon idella

“…Reducing lipid accumulation using creatine in GC is consistent with the response in mammals [6,28]. A previous study showed that fat accumulation increased when tissue creatine decreased in GC upon faba bean consumption [29], suggesting a negative correlation between fat accumulation and creatine. However, our results are not consistent with the red drum carnivorous fish [12,13].…”

“…Third, it is known that the end product of β-oxidation, acetyl-CoA forms NADPH and FADH 2 , as part of the tricarboxylic acid cycle. Moreover, NADPH and FADH 2 then enter the mitochondrial respiratory chain, whereby with the help of five enzymatic complexes ATP is produced [29]. Our in vivo study showed that the protein concentrations of complexes I-V were all increased after the fish were fed creatine, and the in vitro study showed that appropriate concentrations of creatine increased the relative transcript levels of several genes in complexes I-III.…”

Prostaglandin 2α Promotes Autophagy and Mitochondrial Energy Production in Fish Hepatocytes

“…Free fatty acids released through lipolysis or autophagy/lipophagy are transported to the mitochondria for β-oxidation by a series of enzymes to produce acetyl-CoA as the end product [ 18 ]. Acetyl-CoA then enters the tricarboxylic acid cycle to form NADPH and FADH2, which are absorbed by the mitochondrial respiratory chain, through which five enzymatic complexes produce ATP [ 19 , 20 ].…”

VasH Contributes to Virulence of Aeromonas hydrophila and Is Necessary to the T6SS-mediated Bactericidal Effect

“…In recent years, MAS caused by A. hydrophila has hindered the rapid development of carp industry in China and catfish industry in the United States ( 4 , 5 ). Grass carp ( Ctenopharyngodon idellus ) is the fish species with the most significant reported production in aquaculture globally, with a proportion of up to 5.5 million tons per year ( 6 ). Increased incidence of infection and the broad spectrum of antibiotic resistance has made A. hydrophila a severe threat to the aquaculture industry.…”