NMR-based Metabolomic Analysis Of The Effects Of Alanyl-glutamine Supplementation On C2C12 Myoblasts Injured By Energy Deprivation

Skeletal muscle is one of the most dynamic and plastic tissues of the human body,and its function and metabolism alternations play a critical role in the occurrence and of many common pathological conditions and diseases.Muscle dysfunction and injury often occur in sports and many common diseases,and repair and regeneration of injured muscle is a complex physiological process involving multiple factors and signaling pathways.Therefore,understanding the mechanism of development of muscle dysfunction and muscle injury,and looking for effective interventions or remedial measures to promote muscle regeneration,is of great significance for the treatment of muscular diseases and injuries.Cell metabolomics can combine multiple data analysis methods with high-throughput detection techniques to examine changes in endogenous metabolites produced by cells after drug intervention,thereby revealing the mechanism of drug action in cells.Here,based on the importance of skeletal muscle satellite cells in muscle growth,repair and regeneration,we performed nuclear magnetic resonance(NMR)-based metabonomic profiling to analyze the therapeutic effects and molecular mechanisms of the dipeptide alanylglutamine(Ala-Gln),the free alanine(Ala)and glutamine(Gin)supplementations on the mouse myoblast cell line C2C12 injured by glucose and glutamine deprivation(energy deprivation).In the present work,we have found that both Ala,Gin and Ala-Gln supplementations can promote the differentiation ability of the injured C2C12 myoblasts,while only the Ala-Gln supplementation can facilitate the proliferation ability of the injured cells.Ala-Gln supplementation can partially restore the metabolic profile of injured C2C12 myoblasts disturbed by glucose and glutamine deprivation,and exhibit more significant effects than Ala and Gin supplementations.Our results suggest that Ala-Gln supplementation mainly changes the metabolism of injured C2C12 myoblasts in following aspects:(1)Ala-Gln facilitates proliferation and promote MyoD1 protein synthesis;(2)Ala-Gln upregulates the intracellular phosphocreatine(PCr,muscle ATP storage form);(3)Ala-Gin maintains TCA cycle anaplerosis;(4)Ala-Gln enhances the antioxidant capacity through promoting GSH biosynthesis;(5)Ala-Gln stabilizes lipid membranes by suppressing glycerophospholipids metabolism.This work provides new insight into mechanical understanding of the polyphenic effects of Ala-Gln supplementation on muscle myoblasts injured by energy deprivation,suggesting that Ala-Gln is not only a well-known clinical parenteral nutrition supplement,but also a potential supplement for treating disease and exercise-related muscle injuries.Our work may be of benefit to the promotion of Ala-Gln applications for treatments of muscular diseases and injuries.