The L-Ascorbic Acid Increases Proliferation and Differentiation of Yanbian Cattle Skeletal Muscle Satellite Cells by Activating the Akt/mTOR/P70S6K Signaling Pathway

Cell-cultured meat, as a new type of meat food, can effectively mitigate the negative effects of conventional animal husbandry on the environment, health, and animal welfare. Muscle stem cells are the main seed cells for the production of cell- cultured meat, but their weak proliferative capacity in vitro severely limits the large-scale and low-cost production of cell-cultured meat. There is growing evidence that L-ascorbic acid (AA) has the ability to increase the efficiency of muscle stem cell proliferation and differentiation in vitro. However, the role of AA in Yanbian bovine skeletal muscle satellite cells (BSCs) and its molecular mechanisms are unknown. Therefore, in the present study, the promotional effect of AA on the proliferation and differentiation of BSCs was confirmed by the Cell Counting Kit 8 (CCK-8) assay, 5-ethyl-2 '-deoxyuridine (EdU) proliferation assay, real-time quantitative PCR (RT-qPCR), immunoprotein blotting (Western blotting) and immunofluorescence assay. RT-qPCR and Western blotting results showed that AA up-regulated the expression of p-Akt, p-mTOR, and pP70S6K genes and proteins, whereas when the mTOR pathway inhibitor rapamycin was co-treated with AA in BSCs, the expression of p-Akt, p-mTOR, and p-P70S6K genes and proteins was significantly down-regulated. In summary, data suggest that AA regulates the proliferation and differentiation of BSCs by activating the AKT/mTOR/P70S6K signaling pathway. These data provide a practical approach and theoretical basis for the efficient and low-cost manufacture of cell culture meat.