Objective To explore the effect of leucine,the important nutrient for neonatal skeletal muscle growth on myotubes formation and myosin heavy chain (MyHC) expression of primary neonatal rat skeletal muscle satellite cells. Methods The primary neonatal rat skeletal muscle satellite cells were disassociated and purified.In the stage of cell differentiation,they were treated with different concentration of leucine and rapamycin ( 0mM leucine,0.1 mM leucine,0.5 mM leucine,2.0 mM leucine,2.0 mM leucine+50 nM rapamycin).Myotubes were observed and Western blot was performed to detect the expression of MyHC,mammalian target of rapamycin (mTOR),p-mTOR and MyoD. Results Leucine promoted the formation of myotubes.The expression of MyHC gradually increased with the differentiation of primary neonatal rat skeletal muscle satellite cells (P<0.05,P<0.01 or P<0.001).The expression of p-mTOR were higher in the 0.5 mM leucine group and 2.0 mM leucine group than that in the 0mM leucine group (P<0.05 or P<0.01).The expressions of p-mTOR were decreased by rapamycin (P<0.05).The expression of MyoD was higher in the 0.5 mM leucine group and 2.0 mM leucine group than that in the 0 mM leucine group (P<0.05).The expression of MyoD was decreased by rapamycin (P<0.05).The expression of MyHC were higher in the 0.5 mM leucine group and 2.0 mM leucine group than that in the 0 mM leucine group (P<0.05 or P<0.01).The expression of MyHC was decreased by rapamycin (P<0.05). Conclusion Leucine promotes the myotubes formation and MyHC expression of primary neonatal rat skeletal muscle satellite cells in part via mTORC1/MyoD signaling pathway.
Key words
leucine /
neonate /
skeletal muscle satellite cell /
myosin heavy chain /
mammalian target of rapamycin
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