AICAR (5-aminoimidazole-4-carboxamide-1-β-D-ribonucleoside) Decreases Protein Synthesis in C2C12 Myotubes Cultured in High Glucose Media
2012
Park, C.S., National Institute of Animal Science, RDA, Suwon, Republic of Korea | Kim, J.H., National Institute of Animal Science, RDA, Suwon, Republic of Korea | Oh, Y.K., National Institute of Animal Science, RDA, Suwon, Republic of Korea | Kim, K.H., National Institute of Animal Science, RDA, Suwon, Republic of Korea | Choi, C.W., Daegu University, Gyeongsan, Republic of Korea | Cho, E.S., National Institute of Animal Science, RDA, Suwon, Republic of Korea | Jeong, Y.D., National Institute of Animal Science, RDA, Suwon, Republic of Korea | Park, S.K., National Institute of Animal Science, RDA, Suwon, Republic of Korea
AMP-activated protein kinase (AMPK) maintains energy homeostasis in skeletal muscle. Nonetheless, its functional role on protein synthesis with different nutrient availability has not been elucidated. Therefore, the purpose of this study is to examine the effect of AMPK activity on protein content in C2C12 myotubes incubated with low (5 mM; LG) or high (25 mM; HG) glucose media. LG stimulated (p less than 0.05) AMPK and acetyl CoA carboxylase (ACC) activity compare to those in HG group. Total protein content was higher in myotubes cultured with HG than in those cultured with LG and further increased by AICAR (5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide). Myotubes cultured with HG showed 7.5% lower UbFL (Ubiquitin Firefly Luciferase)-to-SV40 (Simian virus40) ratio compared to those in LG. Glucose level did not change the phosphorylation level of mammalian target of rapamycin (mTOR). Interestingly, administration of AICAR significantly increased phosphorylation level of mTOR in myotubes cultured with LG but not in those with HG. Overall, this data indicate that AMPK activity and protein turnover are finely regulated in response to different glucose concentration.
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