Regulation Of PI3K/AKT Signal Pathway On Muscle Metabolic Steady State And Meat Quality During Storage Of Chilled Tan Mutton

The PI3K/AKT signaling pathway plays an important role in stimulating protein synthesis and muscle growth,and regulates important biological processes such as muscle growth,development,metabolism,and homeostasis.Due to the complexity of the PI3K/AKT pathway,the molecular mechanisms underlying the function of the PI3K/AKT signaling pathway and the dynamic regulation of metabolic homeostasis in chilled Tan mutton are still unclear.Therefore,studying the regulatory mechanism of PI3K/AKT signaling pathway in Tan mutton during cooling storage is of great significance.This study focuses on the leg meat of Tan mutton during cooling storage after being treated with PI3K inhibitor(LY294002)injection at 4℃.The expression of PI3K and AKT proteins was analyzed by Western blot to verify the effectiveness of PI3K/AKT signaling pathway blockage.At the same time,cooking loss,shear force,water distribution,texture,and apoptosis related indicators were measured during cooling storage,To study the effect of PI3K/AKT signaling pathway on the quality of Tan mutton,analyze the activation mechanism of PI3K/AKT signaling pathway on the apoptosis pathway of Tan mutton cells during cooling storage,and reveal the mechanism of PI3K/AKT signaling pathway in the metabolic regulation of Tan mutton by combining transcriptome methods.The main research findings are as follows:1.Verified the effectiveness of PI3K/AKT signaling pathway inhibition and explored its impact on meat quality during storage of chilled Tan mutton.The study was conducted on the leg meat of Tan mutton stored at 4℃ for different periods,the chilled Tan mutton was injected with 10μM PI3K inhibitor LY294002 solution and stored for 0,2,4,6 and 8 days respectively.The expression levels of PI3K and AKT proteins were analyzed by polyacrylamide gel electrophoresis(SDS-PAGE)and Western blot to verify whether the PI3K/AKT signal pathway was blocked.In addition,quality indicators such as pH value,color,and texture of meat during storage were measured to analyze how the PI3K/AKT signaling pathway affects the quality of Tan mutton.The results showed that:(1)With the extension of storage days,the expression levels of PI3K and AKT proteins showed a downward trend,indicating that inhibitor LY294002 inactivated the PI3K/AKT signaling pathway.(2)The pH,cooking loss,shear force,and texture of the LY294002 injection group were significantly lower than those of the control group(P<0.05),indicating that the inactivation of the PI3K/AKT signaling pathway accelerated the decrease in pH and shear force of meat,increased MFI,a*,and b*values,and improved water retention;During storage,there was a significant change in the texture parameters of Tan mutton,with a decreasing trend in hardness,elasticity,cohesiveness,and chewiness.These findings indicate that the obstruction of the PI3K/AKT signaling pathway during storage accelerates the tenderization process of Tan mutton,thereby affecting the quality of Tan mutton during cooling storage.2.The activation mechanism of PI3K/AKT signaling pathway on the apoptosis pathway of Tan mutton cells during cooling storage was analyzed.During storage,compared with the control group,the LY294002 treatment group showed a significant decrease in mitochondrial ATP,glycogen content,succinate dehydrogenase(SDH),and citrate synthase(CS)activities(P<0.05);The mitochondrial ROS gradually increases,and the levels of oxidative stress and MPTP opening increase;Membrane potential decreased significantly(P<0.05);The activity of apoptosis factor Caspase-3 was significantly higher than that of the control group(P<0.05),indicating that PI3K/AKT signaling pathway mediated the activation of downstream Caspase-3 by promoting the production of ROS and interacting with PI3K,damaged the structure and function of mitochondria,led to the opening of MPTP,decreased membrane potential,and then induced apoptosis.3.The role of PI3K/AKT signaling pathway in metabolic regulation during storage of chilled Tan mutton was revealed.High-throughput sequencing technology was used to study the changes of transcriptome when the storage period was 0 d,4 d and 8 d after injection treatment with PI3K inhibitor LY294002.Between the control group and the LY294002 treatment group,the number of significantly differentially expressed genes(DEGs)identified at 0 d,4 d,and 8 d was 474,96 and 13,respectively.Functional enrichment analysis showed that DEGs were mainly related to metabolic homeostasis,such as amino acid biosynthesis,glycolysis/gluconeogenesis,and glycerolipid metabolism.In addition,tissue section analysis showed that the myofiber spacing increased in the LY294002 group and the diameter of the myofibers decreased significantly,indicating muscle atrophy.These results suggest that the PI3K/AKT signaling pathway plays a vital role in maintaining metabolic balance during storage of Tan mutton,which in turn ensures normal muscle growth.This study provides direction for further elucidating the molecular mechanism of PI3K/AKT signaling metabolic homeostasis in chilled Tan mutton storage.