Valine enhances intramuscular fat deposition through activating autophagy and fatty acid metabolism pathways in C2C12 myoblasts

The branched-chain amino acids (BCAA) are essential to animal growth and intramuscular fat deposition, and also metabolic health (circulating level elevated in obesity and diabetes). However, the molecular role and effect of valine on muscle growth and fat deposition were less explored. Valine supplementation significantly affected mouse muscle growth, increasing the abdominal fat but decreasing the back fat. In the leg muscle, the expression levels of genes related to autophagy and fat deposition were significantly disturbed. Furthermore, valine promotes lipid deposition in myoblasts in a dose-dependent manner, and co-treatment of valine and palmitic acid can act in concert to enhance lipid deposition in myoblast. Moreover, transcriptome sequencing on myoblasts revealed that the signaling pathways such as mTOR, PI3K-AKT and fatty acid metabolism were activated after valine treatment, and palmitic acid additionally stimulated signaling pathways related to lipid metabolism in myoblasts. Therefore, valine could independently activate the autophagy pathway, and the fatty acid metabolism pathway to enhance intramuscular fat deposition C2C12 cells of mice were taken as samples and sequenced and divided into control group (Control group), labeled C1-C6; 0.45 mM valine treatment group (Valine group), labeled as V1-V6; 0.45 mM+75 μ M Palmitic acid treatment group (Val+PA group), marked as VP1-VP6, randomly selected 3 samples from each group of six samples and sent them to the company for sequencing.