Prior Treatment with AICAR Causes the Selective Phosphorylation of mTOR Substrates in C2C12 Cells
Metabolic stress in skeletal muscle cells causes sustained metabolic changes, but the mechanisms of the prolonged effects are not fully known. In this study, we tested C2C12 cells with the AMP-activated protein kinase (AMPK) stimulator AICAR and measured the changes in the metabolic pathways and sig...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Current Issues in Molecular Biology |
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| Online Access: | https://www.mdpi.com/1467-3045/45/10/508 |
| _version_ | 1797574294355574784 |
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| author | Cass J. Dedert Kazimir R. Bagdady Jonathan S. Fisher |
| author_facet | Cass J. Dedert Kazimir R. Bagdady Jonathan S. Fisher |
| author_sort | Cass J. Dedert |
| collection | DOAJ |
| description | Metabolic stress in skeletal muscle cells causes sustained metabolic changes, but the mechanisms of the prolonged effects are not fully known. In this study, we tested C2C12 cells with the AMP-activated protein kinase (AMPK) stimulator AICAR and measured the changes in the metabolic pathways and signaling kinases. AICAR caused an acute increase in the phosphorylation of the AMPK target ULK1, the mTORC1 substrate S6K, and the mTORC2 target Akt. Intriguingly, prior exposure to AICAR only decreased glucose-6 phosphate dehydrogenase activity when it underwent three-hour recovery after exposure to AICAR in a bicarbonate buffer containing glucose (KHB) instead of Dulbecco’s Minimum Essential Medium (DMEM). The phosphorylation of the mTORC1 target S6K was increased after recovery in DMEM but not KHB, although this appeared to be specific to S6K, as the phosphorylation of the mTORC1 target site on ULK1 was not altered when the cells recovered in DMEM. The phosphorylation of mTORC2 target sites was also heterogenous under these conditions, with Akt increasing at serine 473 while other targets (SGK1 and PKCα) were unaffected. The exposure of cells to rapamycin (an mTORC1 inhibitor) and PP242 (an inhibitor of both mTOR complexes) revealed the differential phosphorylation of mTORC2 substrates. Taken together, the data suggest that prior exposure to AICAR causes the selective phosphorylation of mTOR substrates, even after prolonged recovery in a nutrient-replete medium. |
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| format | Article |
| id | doaj.art-c0435aae3aa94c1bb9710df18b7d3ffe |
| institution | Directory Open Access Journal |
| issn | 1467-3037 1467-3045 |
| language | English |
| last_indexed | 2024-03-10T21:21:00Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
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| series | Current Issues in Molecular Biology |
| spelling | doaj.art-c0435aae3aa94c1bb9710df18b7d3ffe2023-11-19T16:06:29ZengMDPI AGCurrent Issues in Molecular Biology1467-30371467-30452023-09-0145108040805210.3390/cimb45100508Prior Treatment with AICAR Causes the Selective Phosphorylation of mTOR Substrates in C2C12 CellsCass J. Dedert0Kazimir R. Bagdady1Jonathan S. Fisher2Department of Biology, Saint Louis University, St. Louis, MO 63103, USADepartment of Biology, Saint Louis University, St. Louis, MO 63103, USADepartment of Biology, Saint Louis University, St. Louis, MO 63103, USAMetabolic stress in skeletal muscle cells causes sustained metabolic changes, but the mechanisms of the prolonged effects are not fully known. In this study, we tested C2C12 cells with the AMP-activated protein kinase (AMPK) stimulator AICAR and measured the changes in the metabolic pathways and signaling kinases. AICAR caused an acute increase in the phosphorylation of the AMPK target ULK1, the mTORC1 substrate S6K, and the mTORC2 target Akt. Intriguingly, prior exposure to AICAR only decreased glucose-6 phosphate dehydrogenase activity when it underwent three-hour recovery after exposure to AICAR in a bicarbonate buffer containing glucose (KHB) instead of Dulbecco’s Minimum Essential Medium (DMEM). The phosphorylation of the mTORC1 target S6K was increased after recovery in DMEM but not KHB, although this appeared to be specific to S6K, as the phosphorylation of the mTORC1 target site on ULK1 was not altered when the cells recovered in DMEM. The phosphorylation of mTORC2 target sites was also heterogenous under these conditions, with Akt increasing at serine 473 while other targets (SGK1 and PKCα) were unaffected. The exposure of cells to rapamycin (an mTORC1 inhibitor) and PP242 (an inhibitor of both mTOR complexes) revealed the differential phosphorylation of mTORC2 substrates. Taken together, the data suggest that prior exposure to AICAR causes the selective phosphorylation of mTOR substrates, even after prolonged recovery in a nutrient-replete medium.https://www.mdpi.com/1467-3045/45/10/508unc-like kinase 1mammalian target of rapamycinmechanistic target of rapamycin5-aminoimidazole-4-carboxamide ribonucleosideC2C12 cells |
| spellingShingle | Cass J. Dedert Kazimir R. Bagdady Jonathan S. Fisher Prior Treatment with AICAR Causes the Selective Phosphorylation of mTOR Substrates in C2C12 Cells Current Issues in Molecular Biology unc-like kinase 1 mammalian target of rapamycin mechanistic target of rapamycin 5-aminoimidazole-4-carboxamide ribonucleoside C2C12 cells |
| title | Prior Treatment with AICAR Causes the Selective Phosphorylation of mTOR Substrates in C2C12 Cells |
| title_full | Prior Treatment with AICAR Causes the Selective Phosphorylation of mTOR Substrates in C2C12 Cells |
| title_fullStr | Prior Treatment with AICAR Causes the Selective Phosphorylation of mTOR Substrates in C2C12 Cells |
| title_full_unstemmed | Prior Treatment with AICAR Causes the Selective Phosphorylation of mTOR Substrates in C2C12 Cells |
| title_short | Prior Treatment with AICAR Causes the Selective Phosphorylation of mTOR Substrates in C2C12 Cells |
| title_sort | prior treatment with aicar causes the selective phosphorylation of mtor substrates in c2c12 cells |
| topic | unc-like kinase 1 mammalian target of rapamycin mechanistic target of rapamycin 5-aminoimidazole-4-carboxamide ribonucleoside C2C12 cells |
| url | https://www.mdpi.com/1467-3045/45/10/508 |
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