Dietary leucine supplementation alters energy metabolism and induces slow-to-fast transitions inlongissimus dorsimuscle of weanling piglets

Abstract

Leucine plays an important role in promoting muscle protein synthesis and muscle remodelling. However, what percentage of leucine is appropriate in creep feed and what proteome profile alterations are caused by dietary leucine in the skeletal muscle of piglets remain elusive. In this case, we applied isobaric tags for relative and absolute quantitation to analyse the proteome profile of the longissimus dorsi muscles of weanling piglets fed a normal leucine diet (NL; 1·66 % leucine) and a high-leucine diet (HL; 2·1 % leucine). We identified 157 differentially expressed proteins between these two groups. Bioinformatics analysis of these proteins exhibited the suppression of oxidative phosphorylation and fatty acid β-oxidation, as well as the activation of glycolysis, in the HL group. For further confirmation, we identified that SDHB, ATP5F1, ACADM and HADHB were significantly down-regulated (P<0·01, except ATP5F1, P<0·05), whereas the glycolytic enzyme pyruvate kinase was significantly up-regulated (P<0·05) in the HL group. We also show that enhanced muscle protein synthesis and the transition from slow-to-fast fibres are altered by leucine. Together, these results indicate that leucine may alter energy metabolism and promote slow-to-fast transitions in the skeletal muscle of weanling piglets.

Fermented Feed Modulates Meat Quality and Promotes the Growth of Longissimus Thoracis of Late-Finishing Pigs

“…A study by Ahmed et al showed that fermented herb diet increased lean production [20], but the mechanisms underlying this observation remain unknown. Increased amino acid profile of the feed after fermentation may play an important role in skeletal muscle accretion through increased protein synthesis signaling and suppressed degradation signaling in skeletal muscle of LT in finishing pigs [34,35]. Insulin and its receptor play important roles in protein synthesis signaling pathways [36].…”

Leucine Supplementation: A Novel Strategy for Modulating Lipid Metabolism and Energy Homeostasis

“…In growing pigs, Duan et al showed that a low-protein diet with the appropriate ratios of BCAAs was able to increase growth, and as a result regulate lipid metabolism in the skeletal muscle [34]. Similarly, excess dietary Leu, KIC, and HMB may regulate energy homoeostasis, growth performance, and immune responses in weanling or growing pigs [145,146]. Therefore, clarification of the regulatory mechanisms of Leu on lipid metabolism in the adipose tissue may provide a new strategy for the nutritional regulation of amino acids, leading to the application of Leu supplementation as a means to improve livestock carcass.…”

Proteomic Analysis of Beef Tenderloin and Flank Assessed Using an Isobaric Tag for Relative and Absolute Quantitation (iTRAQ)

“…Closely related to life activities, amino acids are the basic components of proteins and are indispensable nutrients in all organisms. Branched chain amino acids (BCAA), including leucine, isoleucine, and valine, are essential amino acids that are mainly oxidised in muscle [14]. These BCAAs take part in the TCA cycle through ketogenic and glycaemic effects, ensuring the conversion of the three major nutrients (proteins, carbohydrates, and lipids) in the body.…”