Regulation of the expression of key signalling molecules in mTOR pathway of skeletal muscle satellite cells in neonatal chicks: Effects of leucine and glycine-leucine peptide.

Abstract

This study was conducted to analyse the effects of leucine (Leu) and glycine (Gly)-Leu peptide on expressions of key signalling molecules in mTOR pathway of skeletal muscle satellite cells in neonatal chicks. The 4-day-old male AA broilers with similar weight were selected to obtain the broiler skeletal muscle satellite cells with the two-step method of collagenase-I and trypsin digestion. The satellite cells were subjected to primary culture in vitro, and they were cultured in DMEM medium with the Leu concentration of 0.2mM and 2mM as well as with the Gly-Leu peptide concentration of 0.2mM and 2mM. The experiment lasted for 5days. The results showed that TOR, S6K1 and 4E-BP1 mRNA expressions in the medium with Leu concentration of 2mM were significantly higher than that in 0.2mM group (p<0.05). There was no difference between the medium with Gly-Leu concentration of 2mM and 0.2mM on the TOR, S6K1 and 4E-BP1 mRNA expressions (p>0.05). In conclusion, Leu significantly increases TOR, S6K1 and 4E-BP1 mRNA expressions of skeletal muscle satellite cells, but Gly-Leu peptide has no effect on them.