1. Blockage of glutamine-dependent anaplerosis affects mTORC1/2 activity and ultimately leads to cellular senescence-like response
- Author
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Geng-You Liao, Ming-Ting Lee, Jhen-Jia Fan, Pei-Wen Hsiao, Chun-Sheng Lee, Shou-Yi Su, Jiuan-Jiuan Hwang, and Ferng-Chun Ke
- Subjects
Amino-oxyacetate ,Cellular senescence ,Glutamine-dependent anaplerosis ,Metabolism ,mTORC ,p16INK4A ,Science ,Biology (General) ,QH301-705.5 - Abstract
The purpose of study was to explore the role of glutamine-dependent anaplerosis in cell fate determination (proliferation and senescence) and the potential associated mechanism by employing a pharmacological inhibitor of glutamine-dependent anaplerosis, amino-oxyacetate (AOA). Using the WI38 normal human embryonic fibroblast cell line, we found that exposure to AOA induced mTORC1 inactivation−mTORC2 activation (within day 1), cell cycle arrest (day 2–6) and cellular senescence (day 4–6). These AOA effects were blocked by concomitantly providing anaplerotic factors [α-ketoglutarate (αKG), pyruvate or oxaloacetate], and not affected by ROS scavenger N-acetyl-cysteine (NAC). Moreover, AOA-induced cellular senescence in WI38 cells is associated with elevated protein levels of p53, p21CIP1 and p16INK4A and decreased Rb protein level, which was blocked by αKG supplementation. In p16INK4A-deficient U2OS human osteosarcoma cells and p16INK4A-knockdown WI38 cells, AOA exposure also induced similar effects on cell proliferation, and protein level of P-Rb-S807/811 and Rb. Interestingly, no AOA induction of cellular senescence was observed in U2OS cells, yet was still seen in p16INK4A-knockdown WI38 cells accompanied by the presence of p16 antibody-reactive p12. In summary, we disclose that glutamine-dependent anaplerosis is essential to cell growth and closely associated with mTORC1 activation and mTORC2 inactivation, and impedes cellular senescence particularly associated with p16INK4A.
- Published
- 2019
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