Quantitative Proteomics And Phosphoproteomics Study On The Effect Of Myostatin Gene On Skeletal Muscle Metabolism

Skeletal muscle is the key part of the body's energy regulation.Myostatin?MSTN?,an important negative regulator of muscle growth,plays a key role in the growth and development of skeletal muscle.A large number of studies have shown that inhibiting the expression of MSTN can not only improve the lean meat production of livestock and poultry in production,but also can be used for the treatment of muscular dystrophy in medicine.The current research on the function of MSTN relies mainly on the MSTN^-/-mouse model.This study shows a deep study on the regulated mechanism of muscle development using high-throughput proteomics and phosphoproteomics techniques on MSTN^-/-bovine model.1.In this study,we detected the protein abundance changes of the leg gluteal muscles in MSTN^-/-Inner Mongolia black cattle and wild type cattle using TMT-6 plex-labeled proteomic techniques.The mass spectrometry results identified a total of 1,678 quantified proteins,72 of which were defined as differentially expressed proteins under the criteria of Fold change=1.55,P?0.05.The functional analysis of these 72 differential proteins revealed that the proteins associated with muscle development were significantly up-regulated in the MSTN^-/-group.And proteins involved in lipid-metabolism,mitochondrial metabolism and activity-related biological processes of the respiratory chain were also up-regulated.Bioinformatics analysis also showed that 72 differential proteins are involved in metabolic pathways such as fatty acid metabolism,oxidative phosphorylation,PPAR signaling pathways and muscle growth and development.2.At the same time as proteomics identification,we used TiO₂ technology to enrich the peptides and performed muscle proteomic analysis of MSTN^-/-Inner Mongolia black cattle and wild type cattle.Finally,1,777 phosphorylated peptides were identified.These peptides were assigned to 433 phosphorylated proteins.Similarly,under the conditions of Fold change=1.55,P?0.05,we obtained 50 differentially expressed phosphopeptides.The peptide corresponds to 36 proteins.Bioinformatics analysis of these 36 differentially phosphorylated proteins revealed that differentially phosphorylated proteins are involved in muscle growth and glycolysis and other biological processes.3.Based on the results of comprehensive proteomics and phosphohistochemistry,we found that the up-regulated differentially expressed proteins in MSTN^-/-bovine muscle tissue are mainly concentrated in the glycolytic pathway and the fatty acid degradation pathway.Based on the results of determination of the original content and intermuscular fat content,we concluded that MSTN^-/-can not only enhance glycogenolysis by enhancing the glycolytic pathway,but also promote the beta oxidation of fatty acids by increasing the activity of mitochondria thereby reducing intermuscular Fat content.The two pathways also provide more energy for muscle growth.At the same time,we also found that MSTN^-/-regulates the growth and development of muscles by increasing the ratio of AMP/ATP and activating the AMPK signaling pathway to exert regulatory functions on glucose metabolism and lipid metabolism.In this study,we performed comparative proteomics and phosphoproteomics analysis on the muscle tissue of MSTN^-/-bovine and wild cattle to study the regulatory mechanisms of MSTN affecting muscle growth and development.On the one hand,we found a series of regulatory proteins related to MSTN function.On the other hand,we found that MSTN can activate the AMPK signaling pathway and regulate the two major metabolic pathways of glucose metabolism and lipid metabolism.The results of this study not only provide a theoretical basis for the study of MSTN on the regulation of muscle growth and development,but also provide a new target for medical research on diabetes and obesity.