1
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Ashraf N, Van Nostrand JL. Fine-tuning AMPK in physiology and disease using point-mutant mouse models. Dis Model Mech 2024; 17:dmm050798. [PMID: 39136185 PMCID: PMC11340815 DOI: 10.1242/dmm.050798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/17/2024] Open
Abstract
AMP-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase that monitors the cellular energy status to adapt it to the fluctuating nutritional and environmental conditions in an organism. AMPK plays an integral part in a wide array of physiological processes, such as cell growth, autophagy and mitochondrial function, and is implicated in diverse diseases, including cancer, metabolic disorders, cardiovascular diseases and neurodegenerative diseases. AMPK orchestrates many different physiological outcomes by phosphorylating a broad range of downstream substrates. However, the importance of AMPK-mediated regulation of these substrates in vivo remains an ongoing area of investigation to better understand its precise role in cellular and metabolic homeostasis. Here, we provide a comprehensive overview of our understanding of the kinase function of AMPK in vivo, as uncovered from mouse models that harbor phosphorylation mutations in AMPK substrates. We discuss some of the inherent limitations of these mouse models, highlight the broader implications of these studies for understanding human health and disease, and explore the valuable insights gained that could inform future therapeutic strategies for the treatment of metabolic and non-metabolic disorders.
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Affiliation(s)
- Naghmana Ashraf
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jeanine L. Van Nostrand
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
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2
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Liu X, Li L, Zhao G, Xiong P. Optimization strategies for CO 2 biological fixation. Biotechnol Adv 2024; 73:108364. [PMID: 38642673 DOI: 10.1016/j.biotechadv.2024.108364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 04/07/2024] [Accepted: 04/14/2024] [Indexed: 04/22/2024]
Abstract
Global sustainable development faces a significant challenge in effectively utilizing CO2. Meanwhile, CO2 biological fixation offers a promising solution. CO2 has the highest oxidation state (+4 valence state), whereas typical multi‑carbon chemicals have lower valence states. The Gibbs free energy (ΔG) changes of CO2 reductive reactions are generally positive and this renders it necessary to input different forms of energy. Although biological carbon fixation processes are friendly to operate, the thermodynamic obstacles must be overcome. To make this reaction occur favorably and efficiently, diverse strategies to enhance CO2 biological fixation efficiency have been proposed by numerous researchers. This article reviews recent advances in optimizing CO2 biological fixation and intends to provide new insights into achieving efficient biological utilization of CO2. It first outlines the thermodynamic characteristics of diverse carbon fixation reactions and proposes optimization directions for CO2 biological fixation. A comprehensive overview of the catalytic mechanisms, optimization strategies, and challenges encountered by common carbon-fixing enzymes is then provided. Subsequently, potential routes for improving the efficiency of biological carbon fixation are discussed, including the ATP supply, reducing power supply, energy supply, reactor design, and carbon enrichment system modules. In addition, effective artificial carbon fixation pathways were summarized and analyzed. Finally, prospects are made for the research direction of continuously improving the efficiency of biological carbon fixation.
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Affiliation(s)
- Xiutao Liu
- School of Life Sciences and Medicine, Shandong University of Technology, 255000 Zibo, China; International Joint Laboratory on Extremophilic Bacteria and Biological Synthesis, Shandong University of Technology, 255000 Zibo, China.
| | - Linqing Li
- School of Life Sciences and Medicine, Shandong University of Technology, 255000 Zibo, China; International Joint Laboratory on Extremophilic Bacteria and Biological Synthesis, Shandong University of Technology, 255000 Zibo, China
| | - Guang Zhao
- State Key Laboratory of Microbial Technology, Shandong University, 266237 Qingdao, China.
| | - Peng Xiong
- School of Life Sciences and Medicine, Shandong University of Technology, 255000 Zibo, China; International Joint Laboratory on Extremophilic Bacteria and Biological Synthesis, Shandong University of Technology, 255000 Zibo, China.
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3
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Li M, Wang Y, Wei X, Cai WF, Wu J, Zhu M, Wang Y, Liu YH, Xiong J, Qu Q, Chen Y, Tian X, Yao L, Xie R, Li X, Chen S, Huang X, Zhang C, Xie C, Wu Y, Xu Z, Zhang B, Jiang B, Wang ZC, Li Q, Li G, Lin SY, Yu L, Piao HL, Deng X, Han J, Zhang CS, Lin SC. AMPK targets PDZD8 to trigger carbon source shift from glucose to glutamine. Cell Res 2024:10.1038/s41422-024-00985-6. [PMID: 38898113 DOI: 10.1038/s41422-024-00985-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 05/28/2024] [Indexed: 06/21/2024] Open
Abstract
The shift of carbon utilization from primarily glucose to other nutrients is a fundamental metabolic adaptation to cope with decreased blood glucose levels and the consequent decline in glucose oxidation. AMP-activated protein kinase (AMPK) plays crucial roles in this metabolic adaptation. However, the underlying mechanism is not fully understood. Here, we show that PDZ domain containing 8 (PDZD8), which we identify as a new substrate of AMPK activated in low glucose, is required for the low glucose-promoted glutaminolysis. AMPK phosphorylates PDZD8 at threonine 527 (T527) and promotes the interaction of PDZD8 with and activation of glutaminase 1 (GLS1), a rate-limiting enzyme of glutaminolysis. In vivo, the AMPK-PDZD8-GLS1 axis is required for the enhancement of glutaminolysis as tested in the skeletal muscle tissues, which occurs earlier than the increase in fatty acid utilization during fasting. The enhanced glutaminolysis is also observed in macrophages in low glucose or under acute lipopolysaccharide (LPS) treatment. Consistent with a requirement of heightened glutaminolysis, the PDZD8-T527A mutation dampens the secretion of pro-inflammatory cytokines in macrophages in mice treated with LPS. Together, we have revealed an AMPK-PDZD8-GLS1 axis that promotes glutaminolysis ahead of increased fatty acid utilization under glucose shortage.
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Affiliation(s)
- Mengqi Li
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Yu Wang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Xiaoyan Wei
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Wei-Feng Cai
- Xiamen Key Laboratory of Radiation Oncology, Xiamen Cancer Center, The First Affiliated Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Jianfeng Wu
- Laboratory Animal Research Centre, Xiamen University, Xiamen, Fujian, China
| | - Mingxia Zhu
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Yongliang Wang
- School of Basic Medical Sciences, Henan University, Kaifeng, Henan, China
| | - Yan-Hui Liu
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Jinye Xiong
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Qi Qu
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Yan Chen
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Xiao Tian
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Luming Yao
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Renxiang Xie
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Xiaomin Li
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Siwei Chen
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Xi Huang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Cixiong Zhang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Changchuan Xie
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Yaying Wu
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Zheni Xu
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Baoding Zhang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Bin Jiang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Zhi-Chao Wang
- School of Pharmacy, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Qinxi Li
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Gang Li
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Shu-Yong Lin
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Li Yu
- State Key Laboratory of Membrane Biology, Tsinghua University-Peking University Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, China
| | - Hai-Long Piao
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, China
| | - Xianming Deng
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Jiahuai Han
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Chen-Song Zhang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China.
| | - Sheng-Cai Lin
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China.
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Wang H, Zheng A, Thorley D, Arias EB, Cartee GD. Independent and combined effects of calorie restriction and AICAR on glucose uptake and insulin signaling in skeletal muscles from 24-month-old female and male rats. Appl Physiol Nutr Metab 2024; 49:614-625. [PMID: 38181403 DOI: 10.1139/apnm-2023-0522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2024]
Abstract
We assessed the effects of two levels of calorie restriction (CR; eating either 15% or 35% less than ad libitum, AL, food intake for 8 weeks) by 24-month-old female and male rats on glucose uptake (GU) and phosphorylation of key signaling proteins (Akt; AMP-activated protein kinase, AMPK; Akt substrate of 160 kDa, AS160) measured in isolated skeletal muscles that underwent four incubation conditions (without either insulin or AICAR, an AMPK activator; with AICAR alone; with insulin alone; or with insulin and AICAR). Regardless of sex: (1) neither CR group versus the AL group had greater GU by insulin-stimulated muscles; (2) phosphorylation of Akt in insulin-stimulated muscles was increased in 35% CR versus AL rats; (3) prior AICAR treatment of muscle resulted in greater GU by insulin-stimulated muscles, regardless of diet; and (4) AICAR caused elevated phosphorylation of acetyl CoA carboxylase, an indicator of AMPK activation, in all diet groups. There was a sexually dimorphic diet effect on AS160 phosphorylation, with 35% CR exceeding AL for insulin-stimulated muscles in male rats, but not in female rats. Our working hypothesis is that the lack of a CR-effect on GU by insulin-stimulated muscles was related to the extended duration of the ex vivo incubation period (290 min compared to 40-50 min that was previously reported to be effective). The observed efficacy of prior treatment of muscles with AICAR to improve glucose uptake in insulin-stimulated muscles supports the strategy of targeting AMPK with the goal of improving insulin sensitivity in older females and males.
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Affiliation(s)
- Haiyan Wang
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Amy Zheng
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Dominic Thorley
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Edward B Arias
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Gregory D Cartee
- Muscle Biology LaboratorySchool of Kinesiology, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
- Institute of Gerontology, University of Michigan, Ann Arbor, MI, USA
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5
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Sunder S, Bauman JS, Decker SJ, Lifton AR, Kumar A. The yeast AMP-activated protein kinase Snf1 phosphorylates the inositol polyphosphate kinase Kcs1. J Biol Chem 2024; 300:105657. [PMID: 38224949 PMCID: PMC10851228 DOI: 10.1016/j.jbc.2024.105657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/31/2023] [Accepted: 01/08/2024] [Indexed: 01/17/2024] Open
Abstract
The yeast Snf1/AMP-activated kinase (AMPK) maintains energy homeostasis, controlling metabolic processes and glucose derepression in response to nutrient levels and environmental cues. Under conditions of nitrogen or glucose limitation, Snf1 regulates pseudohyphal growth, a morphological transition characterized by the formation of extended multicellular filaments. During pseudohyphal growth, Snf1 is required for wild-type levels of inositol polyphosphate (InsP), soluble phosphorylated species of the six-carbon cyclitol inositol that function as conserved metabolic second messengers. InsP levels are established through the activity of a family of inositol kinases, including the yeast inositol polyphosphate kinase Kcs1, which principally generates pyrophosphorylated InsP7. Here, we report that Snf1 regulates Kcs1, affecting Kcs1 phosphorylation and inositol kinase activity. A snf1 kinase-defective mutant exhibits decreased Kcs1 phosphorylation, and Kcs1 is phosphorylated in vivo at Ser residues 537 and 646 during pseudohyphal growth. By in vitro analysis, Snf1 directly phosphorylates Kcs1, predominantly at amino acids 537 and 646. A yeast strain carrying kcs1 encoding Ser-to-Ala point mutations at these residues (kcs1-S537A,S646A) shows elevated levels of pyrophosphorylated InsP7, comparable to InsP7 levels observed upon deletion of SNF1. The kcs1-S537A,S646A mutant exhibits decreased pseudohyphal growth, invasive growth, and cell elongation. Transcriptional profiling indicates extensive perturbation of metabolic pathways in kcs1-S537A,S646A. Growth of kcs1-S537A,S646A is affected on medium containing sucrose and antimycin A, consistent with decreased Snf1p signaling. This work identifies Snf1 phosphorylation of Kcs1, collectively highlighting the interconnectedness of AMPK activity and InsP signaling in coordinating nutrient availability, energy homoeostasis, and cell growth.
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Affiliation(s)
- Sham Sunder
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Joshua S Bauman
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Stuart J Decker
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Alexandra R Lifton
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Anuj Kumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA.
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6
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Ross FA, Hawley SA, Russell FM, Goodman N, Hardie DG. Frequent loss-of-function mutations in the AMPK-α2 catalytic subunit suggest a tumour suppressor role in human skin cancers. Biochem J 2023; 480:1951-1968. [PMID: 37962491 PMCID: PMC10754287 DOI: 10.1042/bcj20230380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 11/07/2023] [Accepted: 11/13/2023] [Indexed: 11/15/2023]
Abstract
The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status activated by increases in AMP or ADP relative to ATP. Once activated, it phosphorylates targets that promote ATP-generating catabolic pathways or inhibit ATP-consuming anabolic pathways, helping to restore cellular energy balance. Analysis of human cancer genome studies reveals that the PRKAA2 gene (encoding the α2 isoform of the catalytic subunit) is often subject to mis-sense mutations in cancer, particularly in melanoma and non-melanoma skin cancers, where up to 70 mis-sense mutations have been documented, often accompanied by loss of the tumour suppressor NF1. Recently it has been reported that knockout of PRKAA2 in NF1-deficient melanoma cells promoted anchorage-independent growth in vitro, as well as growth as xenografts in immunodeficient mice in vivo, suggesting that AMPK-α2 can act as a tumour suppressor in that context. However, very few of the mis-sense mutations in PRKAA2 that occur in human skin cancer and melanoma have been tested to see whether they cause loss-of-function. We have addressed this by making most of the reported mutations and testing their activity when expressed in AMPK knockout cells. Of 55 different mis-sense mutations (representing 75 cases), 9 (12%) appeared to cause a total loss of activity, 18 (24%) a partial loss, 11 (15%) an increase in phenformin-stimulated kinase activity, while just 37 (49%) had no clear effect on kinase activity. This supports the idea that AMPK-α2 acts as a tumour suppressor in the context of human skin cancer.
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Affiliation(s)
- Fiona A. Ross
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
| | - Simon A. Hawley
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
| | - Fiona M. Russell
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
| | - Nicola Goodman
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
| | - D. Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Scotland, U.K
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7
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Steinberg GR, Hardie DG. New insights into activation and function of the AMPK. Nat Rev Mol Cell Biol 2023; 24:255-272. [PMID: 36316383 DOI: 10.1038/s41580-022-00547-x] [Citation(s) in RCA: 201] [Impact Index Per Article: 201.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/23/2022] [Indexed: 11/06/2022]
Abstract
The classical role of AMP-activated protein kinase (AMPK) is as a cellular energy sensor activated by falling energy status, signalled by increases in AMP to ATP and ADP to ATP ratios. Once activated, AMPK acts to restore energy homeostasis by promoting ATP-producing catabolic pathways while inhibiting energy-consuming processes. In this Review, we provide an update on this canonical (AMP/ADP-dependent) activation mechanism, but focus mainly on recently described non-canonical pathways, including those by which AMPK senses the availability of glucose, glycogen or fatty acids and by which it senses damage to lysosomes and nuclear DNA. We also discuss new findings on the regulation of carbohydrate and lipid metabolism, mitochondrial and lysosomal homeostasis, and DNA repair. Finally, we discuss the role of AMPK in cancer, obesity, diabetes, nonalcoholic steatohepatitis (NASH) and other disorders where therapeutic targeting may exert beneficial effects.
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Affiliation(s)
- Gregory R Steinberg
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada.
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
| | - D Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK.
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8
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Morrison KR, Wang T, Chan KY, Trotter EW, Gillespie A, Michael MZ, Oakhill JS, Hagan IM, Petersen J. Elevated basal AMP-activated protein kinase activity sensitizes colorectal cancer cells to growth inhibition by metformin. Open Biol 2023; 13:230021. [PMID: 37042113 PMCID: PMC10090877 DOI: 10.1098/rsob.230021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 03/09/2023] [Indexed: 04/13/2023] Open
Abstract
Expression and activity of the AMP-activated protein kinase (AMPK) α1 catalytic subunit of the heterotrimeric kinase significantly correlates with poor outcome for colorectal cancer patients. Hence there is considerable interest in uncovering signalling vulnerabilities arising from this oncogenic elevation of AMPKα1 signalling. We have therefore attenuated mammalian target of rapamycin (mTOR) control of AMPKα1 to generate a mutant colorectal cancer in which AMPKα1 signalling is elevated because AMPKα1 serine 347 cannot be phosphorylated by mTORC1. The elevated AMPKα1 signalling in this HCT116 α1.S347A cell line confers hypersensitivity to growth inhibition by metformin. Complementary chemical approaches confirmed this relationship in both HCT116 and the genetically distinct HT29 colorectal cells, as AMPK activators imposed vulnerability to growth inhibition by metformin in both lines. Growth inhibition by metformin was abolished when AMPKα1 kinase was deleted. We conclude that elevated AMPKα1 activity modifies the signalling architecture in such a way that metformin treatment compromises cell proliferation. Not only does this mutant HCT116 AMPKα1-S347A line offer an invaluable resource for future studies, but our findings suggest that a robust biomarker for chronic AMPKα1 activation for patient stratification could herald a place for the well-tolerated drug metformin in colorectal cancer therapy.
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Affiliation(s)
- Kaitlin R. Morrison
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, SA 5042, Australia
| | - Tingting Wang
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, SA 5042, Australia
| | - Kuan Yoow Chan
- Cancer Research UK Manchester Institute, Alderley Park, Macclesfield SK10 4TG, UK
| | - Eleanor W. Trotter
- Cancer Research UK Manchester Institute, Alderley Park, Macclesfield SK10 4TG, UK
| | - Ari Gillespie
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, SA 5042, Australia
| | - Michael Z. Michael
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, SA 5042, Australia
- Flinders Centre for Innovation in Cancer, Dept. Gastroenterology and Hepatology, Flinders Medical Centre, Bedford Park, SA 5042, Australia
| | - Jonathan S. Oakhill
- Metabolic Signalling Laboratory, St Vincent's Institute of Medical Research, School of Medicine, University of Melbourne, Victoria 3065, Australia
- Mary MacKillop Institute for Health Research, Australian Catholic University, Victoria 3000, Australia
| | - Iain M. Hagan
- Cancer Research UK Manchester Institute, Alderley Park, Macclesfield SK10 4TG, UK
| | - Janni Petersen
- Flinders Health and Medical Research Institute, Flinders Centre for Innovation in Cancer, Flinders University, Adelaide, SA 5042, Australia
- Nutrition and Metabolism, SouthAustralia Health and Medical Research Institute, Adelaide, SA 5000, Australia
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9
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Caligaris M, Nicastro R, Hu Z, Tripodi F, Hummel JE, Pillet B, Deprez MA, Winderickx J, Rospert S, Coccetti P, Dengjel J, De Virgilio C. Snf1/AMPK fine-tunes TORC1 signaling in response to glucose starvation. eLife 2023; 12:84319. [PMID: 36749016 PMCID: PMC9937656 DOI: 10.7554/elife.84319] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/06/2023] [Indexed: 02/08/2023] Open
Abstract
The AMP-activated protein kinase (AMPK) and the target of rapamycin complex 1 (TORC1) are central kinase modules of two opposing signaling pathways that control eukaryotic cell growth and metabolism in response to the availability of energy and nutrients. Accordingly, energy depletion activates AMPK to inhibit growth, while nutrients and high energy levels activate TORC1 to promote growth. Both in mammals and lower eukaryotes such as yeast, the AMPK and TORC1 pathways are wired to each other at different levels, which ensures homeostatic control of growth and metabolism. In this context, a previous study (Hughes Hallett et al., 2015) reported that AMPK in yeast, that is Snf1, prevents the transient TORC1 reactivation during the early phase following acute glucose starvation, but the underlying mechanism has remained elusive. Using a combination of unbiased mass spectrometry (MS)-based phosphoproteomics, genetic, biochemical, and physiological experiments, we show here that Snf1 temporally maintains TORC1 inactive in glucose-starved cells primarily through the TORC1-regulatory protein Pib2. Our data, therefore, extend the function of Pib2 to a hub that integrates both glucose and, as reported earlier, glutamine signals to control TORC1. We further demonstrate that Snf1 phosphorylates the TORC1 effector kinase Sch9 within its N-terminal region and thereby antagonizes the phosphorylation of a C-terminal TORC1-target residue within Sch9 itself that is critical for its activity. The consequences of Snf1-mediated phosphorylation of Pib2 and Sch9 are physiologically additive and sufficient to explain the role of Snf1 in short-term inhibition of TORC1 in acutely glucose-starved cells.
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Affiliation(s)
- Marco Caligaris
- Department of Biology, University of FribourgFribourgSwitzerland
| | | | - Zehan Hu
- Department of Biology, University of FribourgFribourgSwitzerland
| | - Farida Tripodi
- Department of Biotechnology and Biosciences, University of Milano-BicoccaMilanoItaly
| | - Johannes Erwin Hummel
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of FreiburgFreiburgGermany
| | - Benjamin Pillet
- Department of Biology, University of FribourgFribourgSwitzerland
| | | | | | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of FreiburgFreiburgGermany,Signalling Research Centres BIOSS and CIBSS, University of FreiburgFreiburgGermany
| | - Paola Coccetti
- Department of Biotechnology and Biosciences, University of Milano-BicoccaMilanoItaly
| | - Jörn Dengjel
- Department of Biology, University of FribourgFribourgSwitzerland
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10
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Petsouki E, Cabrera SNS, Heiss EH. AMPK and NRF2: Interactive players in the same team for cellular homeostasis? Free Radic Biol Med 2022; 190:75-93. [PMID: 35918013 DOI: 10.1016/j.freeradbiomed.2022.07.014] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/11/2022] [Accepted: 07/19/2022] [Indexed: 11/27/2022]
Abstract
NRF2 (Nuclear factor E2 p45-related factor 2) is a stress responsive transcription factor lending cells resilience against oxidative, xenobiotic, and also nutrient or proteotoxic insults. AMPK (AMP-activated kinase), considered as prime regulator of cellular energy homeostasis, not only tunes metabolism to provide the cell at any time with sufficient ATP or building blocks, but also controls redox balance and inflammation. Due to observed overlapping cellular responses upon AMPK or NRF2 activation and common stressors impinging on both AMPK and NRF2 signaling, it is plausible to assume that AMPK and NRF2 signaling may interdepend and cooperate to readjust cellular homeostasis. After a short introduction of the two players this narrative review paints the current picture on how AMPK and NRF2 signaling might interact on the molecular level, and highlights their possible crosstalk in selected examples of pathophysiology or bioactivity of drugs and phytochemicals.
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Affiliation(s)
- Eleni Petsouki
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Shara Natalia Sosa Cabrera
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria; Vienna Doctoral School of Pharmaceutical, Nutritional and Sport Sciences (VDS PhaNuSpo), University of Vienna, Austria
| | - Elke H Heiss
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria.
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11
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Liu X, Zhao G, Sun S, Fan C, Feng X, Xiong P. Biosynthetic Pathway and Metabolic Engineering of Succinic Acid. Front Bioeng Biotechnol 2022; 10:843887. [PMID: 35350186 PMCID: PMC8957974 DOI: 10.3389/fbioe.2022.843887] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 02/16/2022] [Indexed: 11/25/2022] Open
Abstract
Succinic acid, a dicarboxylic acid produced as an intermediate of the tricarboxylic acid (TCA) cycle, is one of the most important platform chemicals for the production of various high value-added derivatives. As traditional chemical synthesis processes suffer from nonrenewable resources and environment pollution, succinic acid biosynthesis has drawn increasing attention as a viable, more environmentally friendly alternative. To date, several metabolic engineering approaches have been utilized for constructing and optimizing succinic acid cell factories. In this review, different succinic acid biosynthesis pathways are summarized, with a focus on the key enzymes and metabolic engineering approaches, which mainly include redirecting carbon flux, balancing NADH/NAD+ ratios, and optimizing CO2 supplementation. Finally, future perspectives on the microbial production of succinic acid are discussed.
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Affiliation(s)
- Xiutao Liu
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Guang Zhao
- State Key Lab of Microbial Technology, Shandong University, Qingdao, China
| | - Shengjie Sun
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
| | - Chuanle Fan
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China.,School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Xinjun Feng
- CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Peng Xiong
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, China
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12
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Luo X, Tian T, Feng L, Yang X, Li L, Tan X, Wu W, Li Z, Treves H, Serneels F, Ng IS, Tanaka K, Ren M. Pathogenesis-related protein 1 suppresses oomycete pathogen by targeting against AMPK kinase complex. J Adv Res 2022; 43:13-26. [PMID: 36585103 PMCID: PMC9811325 DOI: 10.1016/j.jare.2022.02.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 01/14/2022] [Accepted: 02/02/2022] [Indexed: 01/07/2023] Open
Abstract
INTRODUCTION During the arms race between plants and pathogens, pathogenesis-related proteins (PR) in host plants play a crucial role in disease resistance, especially PR1. PR1 constitute a secretory peptide family, and their role in plant defense has been widely demonstrated in both hosts and in vitro. However, the mechanisms by which they control host-pathogen interactions and the nature of their targets within the pathogen remain poorly understood. OBJECTIVES The present study was aimed to investigate the anti-oomycete activity of secretory PR1 proteins and elaborate their underlying mechanisms. METHODS This study was conducted in the potato-Phytophthora infestans pathosystem. After being induced by the pathogen infection, the cross-kingdom translocation of secretory PR1 was demonstrated by histochemical assays and western blot, and their targets in P. infestans were identified by yeast-two-hybrid assays, bimolecular fluorescence complementation assays, and co-immunoprecipitation assay. RESULTS The results showed that the expression of secretory PR1-encoding genes was induced during pathogen infection, and the host could deliver PR1 into P. infestans to inhibit its vegetative growth and pathogenicity. The translocated secretory PR1 targeted the subunits of the AMPK kinase complex in P. infestans, thus affecting the AMPK-driven phosphorylation of downstream target proteins, preventing ROS homeostasis, and down-regulating the expression of RxLR effectors. CONCLUSION The results provide novel insights into the molecular function of PR1 in protecting plants against pathogen infection, and uncover a potential target for preventing pre- and post-harvest late blight.
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Affiliation(s)
- Xiumei Luo
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology Zhengzhou Research Base, State Key Laboratory of Cotton Biology; School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China; Hainan Yazhou Bay Seed Laboratory, Hainan 572025, China; Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Tingting Tian
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Li Feng
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology Zhengzhou Research Base, State Key Laboratory of Cotton Biology; School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China; Hainan Yazhou Bay Seed Laboratory, Hainan 572025, China
| | - Xingyong Yang
- School of Life Sciences, Chongqing Normal University, Chongqing 401331, China
| | - Linxuan Li
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology Zhengzhou Research Base, State Key Laboratory of Cotton Biology; School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China; Hainan Yazhou Bay Seed Laboratory, Hainan 572025, China
| | - Xue Tan
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Wenxian Wu
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology Zhengzhou Research Base, State Key Laboratory of Cotton Biology; School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China; Hainan Yazhou Bay Seed Laboratory, Hainan 572025, China
| | - Zhengguo Li
- Key Laboratory of Plant Hormones and Development Regulation of Chongqing, School of Life Sciences, Chongqing University, Chongqing 401331, China
| | - Haim Treves
- School of Plant Sciences and Food Security, Tel-Aviv University, Tel-Aviv 69978, Israel
| | - Francois Serneels
- Centre for agriculture and agro-industry of Hainaut Province, Ath 7800, Belgium
| | - I-Son Ng
- Department of Chemical Engineering, National Cheng Kung University, Taiwan 701, China
| | - Kan Tanaka
- Institute of Innovative Research, Tokyo Institute of Technology, Yokohama 226-8503, Japan
| | - Maozhi Ren
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu 610213, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology Zhengzhou Research Base, State Key Laboratory of Cotton Biology; School of Agricultural Science of Zhengzhou University, Zhengzhou 450000, China; Hainan Yazhou Bay Seed Laboratory, Hainan 572025, China.
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13
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Wang H, Zheng A, Arias EB, Cartee GD. Prior AICAR induces elevated glucose uptake concomitant with greater γ3-AMPK activation and reduced membrane cholesterol in skeletal muscle from 26-month-old rats. Facets (Ott) 2022; 7:774-791. [PMID: 36381195 PMCID: PMC9648397 DOI: 10.1139/facets-2021-0166] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024] Open
Abstract
Attenuated skeletal muscle glucose uptake (GU) has been observed with advancing age. It is important to elucidate the mechanisms linked to interventions that oppose this detrimental outcome. Earlier research using young rodents and (or) cultured myocytes reported that treatment with 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR; an AMP-activated protein kinase (AMPK) activator) can increase γ3-AMPK activity and reduce membrane cholesterol content, each of which has been proposed to elevate GU. However, the effect of AICAR treatment on γ3-AMPK activity and membrane cholesterol in skeletal muscle of aged animals has not been reported. Our purpose was to evaluate the effects of AICAR treatment on these potential mechanisms for enhanced glucose uptake in the skeletal muscle of aged animals. Epitrochlearis muscles from 26-27-month-old male rats were isolated and incubated ± AICAR, followed by 3 h incubation without AICAR, and then incubation with 3-O-methyl-[3 H] glucose (to assess GU ± insulin). Muscles were also analyzed for γ3-AMPK activity and membrane cholesterol content. Prior AICAR treatment led to increased γ3-AMPK activity, reduced membrane cholesterol content, and enhanced glucose uptake in skeletal muscle from aged rats. These observations revealed that two potential mechanisms for greater GU previously observed in younger animals and (or) cell models are also potentially relevant for enhanced GU by muscles from older animals.
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Affiliation(s)
- Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Amy Zheng
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Edward B. Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Gregory D. Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
- Institute of Gerontology, University of Michigan, Ann Arbor, MI, USA
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14
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Zhao Q, Song P, Zou MH. AMPK and Pulmonary Hypertension: Crossroads Between Vasoconstriction and Vascular Remodeling. Front Cell Dev Biol 2021; 9:691585. [PMID: 34169079 PMCID: PMC8217619 DOI: 10.3389/fcell.2021.691585] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022] Open
Abstract
Pulmonary hypertension (PH) is a debilitating and life-threatening disease characterized by increased blood pressure within the pulmonary arteries. Adenosine monophosphate-activated protein kinase (AMPK) is a heterotrimeric serine-threonine kinase that contributes to the regulation of metabolic and redox signaling pathways. It has key roles in the regulation of cell survival and proliferation. The role of AMPK in PH is controversial because both inhibition and activation of AMPK are preventive against PH development. Some clinical studies found that metformin, the first-line antidiabetic drug and the canonical AMPK activator, has therapeutic efficacy during treatment of early-stage PH. Other study findings suggest the use of metformin is preferentially beneficial for treatment of PH associated with heart failure with preserved ejection fraction (PH-HFpEF). In this review, we discuss the "AMPK paradox" and highlight the differential effects of AMPK on pulmonary vasoconstriction and pulmonary vascular remodeling. We also review the effects of AMPK activators and inhibitors on rescue of preexisting PH in animals and include a discussion of gender differences in the response to metformin in PH.
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Affiliation(s)
| | | | - Ming-Hui Zou
- Center for Molecular and Translational Medicine, Georgia State University, Atlanta, GA, United States
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15
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Paquette M, El-Houjeiri L, C Zirden L, Puustinen P, Blanchette P, Jeong H, Dejgaard K, Siegel PM, Pause A. AMPK-dependent phosphorylation is required for transcriptional activation of TFEB and TFE3. Autophagy 2021; 17:3957-3975. [PMID: 33734022 DOI: 10.1080/15548627.2021.1898748] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Increased macroautophagy/autophagy and lysosomal activity promote tumor growth, survival and chemo-resistance. During acute starvation, autophagy is rapidly engaged by AMPK (AMP-activated protein kinase) activation and MTOR (mechanistic target of rapamycin kinase) complex 1 (MTORC1) inhibition to maintain energy homeostasis and cell survival. TFEB (transcription factor E3) and TFE3 (transcription factor binding to IGHM enhancer 3) are master transcriptional regulators of autophagy and lysosomal activity and their cytoplasm/nuclear shuttling is controlled by MTORC1-dependent multisite phosphorylation. However, it is not known whether and how the transcriptional activity of TFEB or TFE3 is regulated. We show that AMPK mediates phosphorylation of TFEB and TFE3 on three serine residues, leading to TFEB and TFE3 transcriptional activity upon nutrient starvation, FLCN (folliculin) depletion and pharmacological manipulation of MTORC1 or AMPK. Collectively, we show that MTORC1 specifically controls TFEB and TFE3 cytosolic retention, whereas AMPK is essential for TFEB and TFE3 transcriptional activity. This dual and opposing regulation of TFEB and TFE3 by MTORC1 and AMPK is reminiscent of the regulation of another critical regulator of autophagy, ULK1 (unc-51 like autophagy activating kinase 1). Surprisingly, we show that chemoresistance is mediated by AMPK-dependent activation of TFEB, which is abolished by pharmacological inhibition of AMPK or mutation of serine 466, 467 and 469 to alanine residues within TFEB. Altogether, we show that AMPK is a key regulator of TFEB and TFE3 transcriptional activity, and we validate AMPK as a promising target in cancer therapy to evade chemotherapeutic resistance.AbbreviationsACACA: acetyl-CoA carboxylase alpha; ACTB: actin beta; AICAR: 5-aminoimidazole-4-carboxamide ribonucleotide; AMPK: AMP-activated protein kinase; AMPKi: AMPK inhibitor, SBI-0206965; CA: constitutively active; CARM1: coactivator-associated arginine methyltransferase 1; CFP: cyan fluorescent protein; CLEAR: coordinated lysosomal expression and regulation; DKO: double knock-out; DMEM: Dulbecco's modified Eagle's medium; DMSO: dimethyl sulfoxide; DQ-BSA: self-quenched BODIPY® dye conjugates of bovine serum albumin; EBSS: Earle's balanced salt solution; FLCN: folliculin; GFP: green fluorescent protein; GST: glutathione S-transferases; HD: Huntington disease; HTT: huntingtin; KO: knock-out; LAMP1: lysosomal associated membrane protein 1; MEF: mouse embryonic fibroblasts; MITF: melanocyte inducing transcription factor; MTORC1: MTOR complex 1; PolyQ: polyglutamine; RPS6: ribosomal protein S6; RT-qPCR: reverse transcription quantitative polymerase chain reaction; TCL: total cell lysates; TFE3: transcription factor binding to IGHM enhancer 3; TFEB: transcription factor EB; TKO: triple knock-out; ULK1: unc-51 like autophagy activating kinase 1.
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Affiliation(s)
- Mathieu Paquette
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada.,Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Leeanna El-Houjeiri
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada.,Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Linda C Zirden
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada.,Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Pietri Puustinen
- Cell Death and Metabolism, Danish Cancer Society Research Center (DCRC), Copenhagen, Denmark
| | - Paola Blanchette
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada.,Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Hyeonju Jeong
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada.,Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Kurt Dejgaard
- Department of Biochemistry, McGill University, Montréal, Québec, Canada
| | - Peter M Siegel
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada.,Department of Biochemistry, McGill University, Montréal, Québec, Canada.,Department of Medicine, McGill University, Montréal, Québec, Canada
| | - Arnim Pause
- Goodman Cancer Research Center, McGill University, Montréal, Québec, Canada.,Department of Biochemistry, McGill University, Montréal, Québec, Canada
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16
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Deng J, Wen C, Ding X, Zhang X, Hou G, Liu A, Xu H, Cao X, Bai Y. LKB1-MARK2 signalling mediates lipopolysaccharide-induced production of cytokines in mouse macrophages. J Cell Mol Med 2020; 24:11307-11317. [PMID: 32841502 PMCID: PMC7576310 DOI: 10.1111/jcmm.15710] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 06/17/2020] [Accepted: 07/10/2020] [Indexed: 01/25/2023] Open
Abstract
Lipopolysaccharide (LPS) is an endotoxin involved in a number of acute and chronic inflammatory syndromes. Although LPS-induced signalling has been extensively studied, there are still mysteries remaining to be revealed. In the current study, we used high-throughput phosphoproteomics to profile LPS-initiated signalling and aimed to find novel mediators. A total of 448 phosphoproteins with 765 phosphorylation sites were identified, and we further validated that the phosphorylation of MARK2 on T208 was important for the regulation on LPS-induced CXCL15 (human IL-8 homolog), IL-1β, IL-6 and TNF-α release, in which LKB1 had a significant contribution. In summary, induction of cytokines by LPS in mouse macrophage is regulated by LKB1-MARK2 signals. Our study provides new clues for further exploring the underlying mechanisms of LPS-induced diseases, and new therapeutic approaches concerning bacterial infection may be derived from these findings.
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Affiliation(s)
- Jie Deng
- Key Laboratory of Diagnosis and Treatment of Severe Hepato-Pancreatic Diseases of Zhejiang Province, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Chunmei Wen
- Key Laboratory of Diagnosis and Treatment of Severe Hepato-Pancreatic Diseases of Zhejiang Province, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xiangyu Ding
- School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xi Zhang
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Guoqing Hou
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Andong Liu
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hui Xu
- Ultrastructural Pathology Laboratory, Department of Pathology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xuan Cao
- Department of Medical Genetics, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yongheng Bai
- Key Laboratory of Diagnosis and Treatment of Severe Hepato-Pancreatic Diseases of Zhejiang Province, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China.,Institute of Chronic Kidney Disease, Wenzhou Medical University, Wenzhou, China
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17
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Zheng X, Arias EB, Qi NR, Saunders TL, Cartee GD. In vivo glucoregulation and tissue-specific glucose uptake in female Akt substrate 160 kDa knockout rats. PLoS One 2020; 15:e0223340. [PMID: 32053588 PMCID: PMC7018090 DOI: 10.1371/journal.pone.0223340] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/26/2020] [Indexed: 01/31/2023] Open
Abstract
The Rab GTPase activating protein known as Akt substrate of 160 kDa (AS160 or TBC1D4) regulates insulin-stimulated glucose uptake in skeletal muscle, the heart, and white adipose tissue (WAT). A novel rat AS160-knockout (AS160-KO) was created with CRISPR/Cas9 technology. Because female AS160-KO versus wild type (WT) rats had not been previously evaluated, the primary objective of this study was to compare female AS160-KO rats with WT controls for multiple, important metabolism-related endpoints. Body mass and composition, physical activity, and energy expenditure were not different between genotypes. AS160-KO versus WT rats were glucose intolerant based on an oral glucose tolerance test (P<0.001) and insulin resistant based on a hyperinsulinemic-euglycemic clamp (HEC; P<0.001). Tissue glucose uptake during the HEC of female AS160-KO versus WT rats was: 1) significantly lower in epitrochlearis (P<0.05) and extensor digitorum longus (EDL; P<0.01) muscles of AS160-KO compared to WT rats; 2) not different in soleus, gastrocnemius or WAT; and 3) ~3-fold greater in the heart (P<0.05). GLUT4 protein content was reduced in AS160-KO versus WT rats in the epitrochlearis (P<0.05), EDL (P<0.05), gastrocnemius (P<0.05), soleus (P<0.05), WAT (P<0.05), and the heart (P<0.005). Insulin-stimulated glucose uptake by isolated epitrochlearis and soleus muscles was lower (P<0.001) in AS160-KO versus WT rats. Akt phosphorylation of insulin-stimulated tissues was not different between the genotypes. A secondary objective was to probe processes that might account for the genotype-related increase in myocardial glucose uptake, including glucose transporter protein abundance (GLUT1, GLUT4, GLUT8, SGLT1), hexokinase II protein abundance, and stimulation of the AMP-activated protein kinase (AMPK) pathway. None of these parameters differed between genotypes. Metabolic phenotyping in the current study revealed AS160 deficiency produced a profound glucoregulatory phenotype in female AS160-KO rats that was strikingly similar to the results previously reported in male AS160-KO rats.
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Affiliation(s)
- Xiaohua Zheng
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Edward B. Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Nathan R. Qi
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, United States of America
| | - Thomas L. Saunders
- Transgenic Animal Model Core, University of Michigan Medical School, Ann Arbor, MI, United States of America
| | - Gregory D. Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, United States of America
- Division of Genetic Medicine Genetics, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States of America
- Institute of Gerontology, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
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18
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Hawley SA, Ross FA, Russell FM, Atrih A, Lamont DJ, Hardie DG. Mechanism of Activation of AMPK by Cordycepin. Cell Chem Biol 2020; 27:214-222.e4. [PMID: 31991096 PMCID: PMC7031697 DOI: 10.1016/j.chembiol.2020.01.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/27/2019] [Accepted: 01/06/2020] [Indexed: 12/22/2022]
Abstract
Cordycepin (3′-deoxyadenosine) is a major bioactive agent in Cordyceps militaris, a fungus used in traditional Chinese medicine. It has been proposed to have many beneficial metabolic effects by activating AMP-activated protein kinase (AMPK), but the mechanism of activation remained uncertain. We report that cordycepin enters cells via adenosine transporters and is converted by cellular metabolism into mono-, di-, and triphosphates, which at high cordycepin concentrations can almost replace cellular adenine nucleotides. AMPK activation by cordycepin in intact cells correlates with the content of cordycepin monophosphate and not other cordycepin or adenine nucleotides. Genetic knockout of AMPK sensitizes cells to the cytotoxic effects of cordycepin. In cell-free assays, cordycepin monophosphate mimics all three effects of AMP on AMPK, while activation in cells is blocked by a γ-subunit mutation that prevents activation by AMP. Thus, cordycepin is a pro-drug that activates AMPK by being converted by cellular metabolism into the AMP analog cordycepin monophosphate. Cordycepin (100 μM) activates AMPK in human cells; higher concentrations are toxic Cordycepin is taken up into cells and converted into mono-, di-, and triphosphates AMPK activation correlates with the cellular content of cordycepin monophosphate Cordycepin monophosphate mimics all three effects of AMP on AMPK in cell-free assays
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Affiliation(s)
- Simon A Hawley
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Fiona A Ross
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Fiona M Russell
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Abdelmadjid Atrih
- Fingerprints Proteomics Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - Douglas J Lamont
- Fingerprints Proteomics Facility, School of Life Sciences, University of Dundee, Dundee, UK
| | - D Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
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19
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Matzinger M, Fischhuber K, Pölöske D, Mechtler K, Heiss EH. AMPK leads to phosphorylation of the transcription factor Nrf2, tuning transactivation of selected target genes. Redox Biol 2020; 29:101393. [PMID: 31805502 PMCID: PMC6909106 DOI: 10.1016/j.redox.2019.101393] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 11/14/2019] [Accepted: 11/23/2019] [Indexed: 12/22/2022] Open
Abstract
The transcription factor Nrf2 (nuclear factor (erythroid-derived 2)-like 2) and the kinase AMPK (AMP-activated protein kinase) participate in the cellular adaptive response to redox or energy stress. Despite accumulating evidence for positive cooperativity between both proteins, information about direct post-translational modification of Nrf2 by AMPK in living cells is scarce. Here, MS-based analysis of immunoprecipitated Nrf2 revealed serine 374, 408 and 433 in human Nrf2 to be hyperphosphorylated as a function of activated AMPK. A direct phosphate-transfer by AMPK to those sites was indicated by in vitro kinase assays with recombinant proteins as well as interaction of AMPK and Nrf2 in cells, evident by co-immunoprecipitation. Mutation of serine 374, 408 and 433 to alanine did not markedly affect half-life, nuclear accumulation or induction of reporter gene expression upon Nrf2 activation with sulforaphane. However, some selected endogenous Nrf2 target genes responded with decreased induction when the identified phosphosites were mutated, whereas others remained unaffected. Notably, the genes susceptible to the mutation of the phosphorylation sites in Nrf2 consistently showed reduced induction in AMPKα1 -/-cells. Overall, our data reveal AMPK-triggered phosphorylation of Nrf2 at three serine residues, apparently determining the extent of transactivation of selected target genes.
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Affiliation(s)
- Manuel Matzinger
- Department of Pharmacognosy, University of Vienna, Vienna, Austria; Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | | | - Daniel Pölöske
- Department of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Karl Mechtler
- Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria; Institute of Molecular Biotechnology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Elke H Heiss
- Department of Pharmacognosy, University of Vienna, Vienna, Austria.
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20
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Matzinger M, Fischhuber K, Pölöske D, Mechtler K, Heiss EH. AMPK leads to phosphorylation of the transcription factor Nrf2, tuning transactivation of selected target genes. Redox Biol 2019. [PMID: 31805502 DOI: 10.1016/j.redox.2019.101393.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2022] Open
Abstract
The transcription factor Nrf2 (nuclear factor (erythroid-derived 2)-like 2) and the kinase AMPK (AMP-activated protein kinase) participate in the cellular adaptive response to redox or energy stress. Despite accumulating evidence for positive cooperativity between both proteins, information about direct post-translational modification of Nrf2 by AMPK in living cells is scarce. Here, MS-based analysis of immunoprecipitated Nrf2 revealed serine 374, 408 and 433 in human Nrf2 to be hyperphosphorylated as a function of activated AMPK. A direct phosphate-transfer by AMPK to those sites was indicated by in vitro kinase assays with recombinant proteins as well as interaction of AMPK and Nrf2 in cells, evident by co-immunoprecipitation. Mutation of serine 374, 408 and 433 to alanine did not markedly affect half-life, nuclear accumulation or induction of reporter gene expression upon Nrf2 activation with sulforaphane. However, some selected endogenous Nrf2 target genes responded with decreased induction when the identified phosphosites were mutated, whereas others remained unaffected. Notably, the genes susceptible to the mutation of the phosphorylation sites in Nrf2 consistently showed reduced induction in AMPKα1 -/-cells. Overall, our data reveal AMPK-triggered phosphorylation of Nrf2 at three serine residues, apparently determining the extent of transactivation of selected target genes.
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Affiliation(s)
- Manuel Matzinger
- Department of Pharmacognosy, University of Vienna, Vienna, Austria; Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria
| | | | - Daniel Pölöske
- Department of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Karl Mechtler
- Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Vienna, Austria; Institute of Molecular Biotechnology, Austrian Academy of Sciences, Vienna BioCenter (VBC), Vienna, Austria
| | - Elke H Heiss
- Department of Pharmacognosy, University of Vienna, Vienna, Austria.
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21
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Al-Bayati A, Brown A, Walker M. Impaired enhancement of insulin action in cultured skeletal muscle cells from insulin resistant type 2 diabetic patients in response to contraction using electrical pulse stimulation. J Diabetes Complications 2019; 33:107412. [PMID: 31575461 DOI: 10.1016/j.jdiacomp.2019.107412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 11/21/2022]
Abstract
AIMS Skeletal muscle insulin resistance is a characteristic feature of type 2 diabetes. The aim of this study was to examine the effect of contraction on insulin action using electrical pulse stimulation (EPS) in cultured skeletal muscle cells from insulin resistant type 2 diabetic patients. METHODS Skeletal muscle cell cultures were established from 6 insulin resistant type 2 diabetic subjects and age and BMI matched non-diabetic control subjects. Day 7 differentiated myotubes were treated with or without EPS for 16 h, after which glucose uptake and AS160 phosphorylation were measured in the presence or absence of insulin. RESULTS In control myotubes, EPS resulted in increased phosphorylation of AMPKThr172 (vs no EPS; p < 0.01), and this was associated with increased glucose uptake (p < 0.05). Insulin in the absence of EPS increased glucose uptake and AS160Thr642 phosphorylation, and both effects were significantly enhanced by prior EPS. In the absence of EPS, AMPK activation was significantly increased (p < 0.01) in the diabetic vs control myotubes. Despite a comparable degree of AMPK activation following EPS, the action of insulin on glucose uptake (p < 0.05) and AS160Thr642 phosphorylation (p < 0.001) was decreased in the diabetic vs control myotubes. CONCLUSION EPS mediated AMPK activation enhances the effect of insulin on glucose uptake and AS160Thr642 phosphorylation in control myotubes replicating key metabolic benefits of exercise on insulin action in man. Conversely, insulin mediated glucose uptake and AS160Thr642 phosphorylation remain significantly decreased in diabetic vs control myotubes despite a comparable degree of AMPK activation following EPS.
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Affiliation(s)
- Ali Al-Bayati
- Institute of Cellular Medicine, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom; Mustansiriyah University, College of Medicine, Department of Chemistry and Biochemistry, Baghdad, Iraq.
| | - Audrey Brown
- Institute of Cellular Medicine, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Mark Walker
- Institute of Cellular Medicine, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
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22
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Pataky MW, Van Acker SL, Dhingra R, Freeburg MM, Arias EB, Oki K, Wang H, Treebak JT, Cartee GD. Fiber type-specific effects of acute exercise on insulin-stimulated AS160 phosphorylation in insulin-resistant rat skeletal muscle. Am J Physiol Endocrinol Metab 2019; 317:E984-E998. [PMID: 31573845 PMCID: PMC6957376 DOI: 10.1152/ajpendo.00304.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Muscle is a heterogeneous tissue composed of multiple fiber types. Earlier research revealed fiber type-selective postexercise effects on insulin-stimulated glucose uptake (ISGU) from insulin-resistant rats (increased for type IIA, IIB, IIBX, and IIX, but not type I). In whole muscle from insulin-resistant rats, the exercise increase in ISGU is accompanied by an exercise increase in insulin-stimulated AS160 phosphorylation (pAS160), an ISGU-regulating protein. We hypothesized that, in insulin-resistant muscle, the fiber type-selective exercise effects on ISGU would correspond to the fiber type-selective exercise effects on pAS160. Rats were fed a 2-wk high-fat diet (HFD) and remained sedentary (SED) or exercised before epitrochlearis muscles were dissected either immediately postexercise (IPEX) or at 3 h postexercise (3hPEX) using an exercise protocol that previously revealed fiber type-selective effects on ISGU. 3hPEX muscles and SED controls were incubated ± 100µU/mL insulin. Individual myofibers were isolated and pooled on the basis of myosin heavy chain (MHC) expression, and key phosphoproteins were measured. Myofiber glycogen and MHC expression were evaluated in muscles from other SED, IPEX, and 3hPEX rats. Insulin-stimulated pAktSer473 and pAktThr308 were unaltered by exercise in all fiber types. Insulin-stimulated pAS160 was greater for 3hPEX vs. SED on at least one phosphosite (Ser588, Thr642, and/or Ser704) in type IIA, IIBX, and IIB fibers, but not in type I or IIX fibers. Both IPEX and 3hPEX glycogen were decreased versus SED in all fiber types. These results provided evidence that fiber type-specific pAS160 in insulin-resistant muscle may play a role in the previously reported fiber type-specific elevation in ISGU in some, but not all, fiber types.
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Affiliation(s)
- Mark W Pataky
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Sydney L Van Acker
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Rhea Dhingra
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Marina M Freeburg
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Edward B Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Kentaro Oki
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Jonas T Treebak
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan
- Institute of Gerontology, University of Michigan, Ann Arbor, Michigan
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23
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Hu Y, Xu W, Hu S, Lian L, Zhu J, Shi L, Ren A, Zhao M. InGanoderma lucidum, Glsnf1 regulates cellulose degradation by inhibiting GlCreA during the utilization of cellulose. Environ Microbiol 2019; 22:107-121. [DOI: 10.1111/1462-2920.14826] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 10/05/2019] [Indexed: 01/16/2023]
Affiliation(s)
- Yanru Hu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life SciencesNanjing Agricultural University Jiangsu 210095 Nanjing People's Republic of China
| | - Wenzhao Xu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life SciencesNanjing Agricultural University Jiangsu 210095 Nanjing People's Republic of China
| | - Shishan Hu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life SciencesNanjing Agricultural University Jiangsu 210095 Nanjing People's Republic of China
| | - Lingdan Lian
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life SciencesNanjing Agricultural University Jiangsu 210095 Nanjing People's Republic of China
| | - Jing Zhu
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life SciencesNanjing Agricultural University Jiangsu 210095 Nanjing People's Republic of China
| | - Liang Shi
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life SciencesNanjing Agricultural University Jiangsu 210095 Nanjing People's Republic of China
| | - Ang Ren
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life SciencesNanjing Agricultural University Jiangsu 210095 Nanjing People's Republic of China
| | - MingWen Zhao
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, Microbiology Department, College of Life SciencesNanjing Agricultural University Jiangsu 210095 Nanjing People's Republic of China
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24
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Vara-Ciruelos D, Russell FM, Hardie DG. The strange case of AMPK and cancer: Dr Jekyll or Mr Hyde? †. Open Biol 2019; 9:190099. [PMID: 31288625 PMCID: PMC6685927 DOI: 10.1098/rsob.190099] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 06/11/2019] [Indexed: 02/06/2023] Open
Abstract
The AMP-activated protein kinase (AMPK) acts as a cellular energy sensor. Once switched on by increases in cellular AMP : ATP ratios, it acts to restore energy homeostasis by switching on catabolic pathways while switching off cell growth and proliferation. The canonical AMP-dependent mechanism of activation requires the upstream kinase LKB1, which was identified genetically to be a tumour suppressor. AMPK can also be switched on by increases in intracellular Ca2+, by glucose starvation and by DNA damage via non-canonical, AMP-independent pathways. Genetic studies of the role of AMPK in mouse cancer suggest that, before disease arises, AMPK acts as a tumour suppressor that protects against cancer, with this protection being further enhanced by AMPK activators such as the biguanide phenformin. However, once cancer has occurred, AMPK switches to being a tumour promoter instead, enhancing cancer cell survival by protecting against metabolic, oxidative and genotoxic stresses. Studies of genetic changes in human cancer also suggest diverging roles for genes encoding subunit isoforms, with some being frequently amplified, while others are mutated.
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Affiliation(s)
| | | | - D. Grahame Hardie
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
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25
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Wang H, Arias EB, Oki K, Pataky MW, Almallouhi JA, Cartee GD. Fiber type-selective exercise effects on AS160 phosphorylation. Am J Physiol Endocrinol Metab 2019; 316:E837-E851. [PMID: 30835507 PMCID: PMC6580176 DOI: 10.1152/ajpendo.00528.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Earlier research using muscle tissue demonstrated that postexercise elevation in insulin-stimulated glucose uptake (ISGU) occurs concomitant with greater insulin-stimulated Akt substrate of 160 kDa (AS160) phosphorylation (pAS160) on sites that regulate ISGU. Because skeletal muscle is a heterogeneous tissue, we previously isolated myofibers from rat epitrochlearis to assess fiber type-selective ISGU. Exercise induced greater ISGU in type I, IIA, IIB, and IIBX but not IIX fibers. This study tested if exercise effects on pAS160 correspond with previously published fiber type-selective exercise effects on ISGU. Rats were studied immediately postexercise (IPEX) or 3.5 h postexercise (3.5hPEX) with time-matched sedentary controls. Myofibers dissected from the IPEX experiment were analyzed for fiber type (myosin heavy chain isoform expression) and key phosphoproteins. Isolated muscles from the 3.5hPEX experiment were incubated with or without insulin. Myofibers (3.5hPEX) were analyzed for fiber type, key phosphoproteins, and GLUT4 protein abundance. We hypothesized that insulin-stimulated pAS160 at 3.5hPEX would exceed sedentary controls only in fiber types characterized by greater ISGU postexercise. Values for phosphorylation of AMP-activated kinase substrates (acetyl CoA carboxylaseSer79 and AS160Ser704) from IPEX muscles exceeded sedentary values in each fiber type, suggesting exercise recruitment of all fiber types. Values for pAS160Thr642 and pAS160Ser704 from insulin-stimulated muscles 3.5hPEX exceeded sedentary values for type I, IIA, IIB, and IIBX but not IIX fibers. GLUT4 abundance was unaltered 3.5hPEX in any fiber type. These results advanced understanding of exercise-induced insulin sensitization by providing compelling support for the hypothesis that enhanced insulin-stimulated phosphorylation of AS160 is linked to elevated ISGU postexercise at a fiber type-specific level independent of altered GLUT4 expression.
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Affiliation(s)
- Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
| | - Edward B Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
| | - Kentaro Oki
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
| | - Mark W Pataky
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
| | - Jalal A Almallouhi
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
| | - Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan , Ann Arbor, Michigan
- Department of Molecular and Integrative Physiology, University of Michigan , Ann Arbor, Michigan
- Institute of Gerontology, University of Michigan , Ann Arbor, Michigan
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26
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Lian J, Watts R, Quiroga AD, Beggs MR, Alexander RT, Lehner R. Ces1d deficiency protects against high-sucrose diet-induced hepatic triacylglycerol accumulation. J Lipid Res 2019; 60:880-891. [PMID: 30737251 PMCID: PMC6446703 DOI: 10.1194/jlr.m092544] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Indexed: 12/20/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Triacylglycerol accumulation in the liver is a hallmark of NAFLD. Metabolic studies have confirmed that increased hepatic de novo lipogenesis (DNL) in humans contributes to fat accumulation in the liver and to NAFLD progression. Mice deficient in carboxylesterase (Ces)1d expression are protected from high-fat diet-induced hepatic steatosis. To investigate whether loss of Ces1d can also mitigate steatosis induced by over-activated DNL, WT and Ces1d-deficient mice were fed a lipogenic high-sucrose diet (HSD). We found that Ces1d-deficient mice were protected from HSD-induced hepatic lipid accumulation. Mechanistically, Ces1d deficiency leads to activation of AMP-activated protein kinase and inhibitory phosphorylation of acetyl-CoA carboxylase. Together with our previous demonstration that Ces1d deficiency attenuated high-fat diet-induced steatosis, this study suggests that inhibition of CES1 (the human ortholog of Ces1d) might represent a novel pharmacological target for prevention and treatment of NAFLD.
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Affiliation(s)
- Jihong Lian
- Group on Molecular and Cell Biology of Lipids University of Alberta, Alberta, Canada; Departments of Pediatrics, University of Alberta, Alberta, Canada
| | - Russell Watts
- Group on Molecular and Cell Biology of Lipids University of Alberta, Alberta, Canada; Departments of Pediatrics, University of Alberta, Alberta, Canada
| | - Ariel D Quiroga
- Instituto de Fisiología Experimental (IFISE), Área Morfología, Facultad de Ciencias Bioquímicas y Farmacéuticas, CONICET, UNR, Rosario, Argentina
| | | | - R Todd Alexander
- Departments of Pediatrics, University of Alberta, Alberta, Canada; Physiology, University of Alberta, Alberta, Canada
| | - Richard Lehner
- Group on Molecular and Cell Biology of Lipids University of Alberta, Alberta, Canada; Departments of Pediatrics, University of Alberta, Alberta, Canada; Cell Biology, University of Alberta, Alberta, Canada.
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27
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Waise TMZ, Rasti M, Duca FA, Zhang SY, Bauer PV, Rhodes CJ, Lam TKT. Inhibition of upper small intestinal mTOR lowers plasma glucose levels by inhibiting glucose production. Nat Commun 2019; 10:714. [PMID: 30755615 PMCID: PMC6372624 DOI: 10.1038/s41467-019-08582-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 01/16/2019] [Indexed: 12/11/2022] Open
Abstract
Glucose homeostasis is partly controlled by the energy sensor mechanistic target of rapamycin (mTOR) in the muscle and liver. However, whether mTOR in the small intestine affects glucose homeostasis in vivo remains unknown. Here, we first report that delivery of rapamycin or an adenovirus encoding the dominant negative acting mTOR-mutated protein into the upper small intestine is sufficient to inhibit small intestinal mTOR signaling and lower glucose production in rodents with high fat diet-induced insulin resistance. Second, we found that molecular activation of small intestinal mTOR blunts the glucose-lowering effect of the oral anti-diabetic agent metformin, while inhibiting small intestinal mTOR alone lowers plasma glucose levels by inhibiting glucose production in rodents with diabetes as well. Thus, these findings illustrate that inhibiting upper small intestinal mTOR is sufficient and necessary to lower glucose production and enhance glucose homeostasis, and thereby unveil a previously unappreciated glucose-lowering effect of small intestinal mTOR. The mechanistic target of rapamycin (TOR) functions as an energy sensor and contributes to the control of glucose homeostasis. Here, the authors show that mTOR in the upper small intestine regulates hepatic glucose production and is required for the glucose lowering effect of metformin.
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Affiliation(s)
- T M Zaved Waise
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada
| | - Mozhgan Rasti
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada
| | - Frank A Duca
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada.,School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, 85721, USA
| | - Song-Yang Zhang
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada
| | - Paige V Bauer
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada.,Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Christopher J Rhodes
- Kovler Diabetes Center, Department of Medicine, Section of Endocrinology, Diabetes and Metabolism, University of Chicago, Chicago, IL, 60637, USA.,MedImmune LLC, Gaithersburg, MD, 20878, USA
| | - Tony K T Lam
- Toronto General Hospital Research Institute, UHN, Toronto, ON, M5G 1L7, Canada. .,Department of Physiology, University of Toronto, Toronto, ON, M5S 1A8, Canada. .,Department of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada. .,Banting and Best Diabetes Centre, University of Toronto, Toronto, ON, M5G 2C4, Canada.
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28
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Abstract
The role of the energy sensor AMPK-activated protein kinase (AMPK) in the insulin-secreting β-cell remains unclear and a subject of intense research. With this chapter, we aim to provide a detailed description of the methods that our group routinely applies to the study of AMPK function in mouse and human pancreatic islets. Thus, we provide detailed protocols to isolate and/or culture mouse and human islets, to modulate and measure AMPK activity in isolated islets, and to evaluate its impact on islet function.
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29
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Moral-Sanz J, Lewis SA, MacMillan S, Ross FA, Thomson A, Viollet B, Foretz M, Moran C, Hardie DG, Evans AM. The LKB1-AMPK-α1 signaling pathway triggers hypoxic pulmonary vasoconstriction downstream of mitochondria. Sci Signal 2018; 11:11/550/eaau0296. [PMID: 30279167 DOI: 10.1126/scisignal.aau0296] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Hypoxic pulmonary vasoconstriction (HPV), which aids ventilation-perfusion matching in the lungs, is triggered by mechanisms intrinsic to pulmonary arterial smooth muscles. The unique sensitivity of these muscles to hypoxia is conferred by mitochondrial cytochrome c oxidase subunit 4 isoform 2, the inhibition of which has been proposed to trigger HPV through increased generation of mitochondrial reactive oxygen species. Contrary to this model, we have shown that the LKB1-AMPK-α1 signaling pathway is critical to HPV. Spectral Doppler ultrasound revealed that deletion of the AMPK-α1 catalytic subunit blocked HPV in mice during mild (8% O2) and severe (5% O2) hypoxia, whereas AMPK-α2 deletion attenuated HPV only during severe hypoxia. By contrast, neither of these genetic manipulations affected serotonin-induced reductions in pulmonary vascular flow. HPV was also attenuated by reduced expression of LKB1, a kinase that activates AMPK during energy stress, but not after deletion of CaMKK2, a kinase that activates AMPK in response to increases in cytoplasmic Ca2+ Fluorescence imaging of acutely isolated pulmonary arterial myocytes revealed that AMPK-α1 or AMPK-α2 deletion did not affect mitochondrial membrane potential during normoxia or hypoxia. However, deletion of AMPK-α1, but not of AMPK-α2, blocked hypoxia from inhibiting KV1.5, the classical "oxygen-sensing" K+ channel in pulmonary arterial myocytes. We conclude that LKB1-AMPK-α1 signaling pathways downstream of mitochondria are critical for the induction of HPV, in a manner also supported by AMPK-α2 during severe hypoxia.
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Affiliation(s)
- Javier Moral-Sanz
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Sophronia A Lewis
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Sandy MacMillan
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Fiona A Ross
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Adrian Thomson
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Benoit Viollet
- Institut Cochin, INSERM U1016, Sorbonne Paris cité, 75014 Paris, France.,CNRS UMR 8104, Sorbonne Paris cité, 75014 Paris, France.,Université Paris Descartes, Sorbonne Paris cité, 75014 Paris, France
| | - Marc Foretz
- Institut Cochin, INSERM U1016, Sorbonne Paris cité, 75014 Paris, France.,CNRS UMR 8104, Sorbonne Paris cité, 75014 Paris, France.,Université Paris Descartes, Sorbonne Paris cité, 75014 Paris, France
| | - Carmel Moran
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - D Grahame Hardie
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - A Mark Evans
- Centre for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, Hugh Robson Building, University of Edinburgh, Edinburgh EH8 9XD, UK.
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30
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The Role of Free Radicals in Autophagy Regulation: Implications for Ageing. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:2450748. [PMID: 29682156 PMCID: PMC5846360 DOI: 10.1155/2018/2450748] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 01/05/2018] [Accepted: 01/16/2018] [Indexed: 12/19/2022]
Abstract
Reactive oxygen and nitrogen species (ROS and RNS, resp.) have been traditionally perceived solely as detrimental, leading to oxidative damage of biological macromolecules and organelles, cellular demise, and ageing. However, recent data suggest that ROS/RNS also plays an integral role in intracellular signalling and redox homeostasis (redoxtasis), which are necessary for the maintenance of cellular functions. There is a complex relationship between cellular ROS/RNS content and autophagy, which represents one of the major quality control systems in the cell. In this review, we focus on redox signalling and autophagy regulation with a special interest on ageing-associated changes. In the last section, we describe the role of autophagy and redox signalling in the context of Alzheimer's disease as an example of a prevalent age-related disorder.
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31
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Shen Y, Sherman JW, Chen X, Wang R. Phosphorylation of CDC25C by AMP-activated protein kinase mediates a metabolic checkpoint during cell-cycle G 2/M-phase transition. J Biol Chem 2018; 293:5185-5199. [PMID: 29467227 PMCID: PMC5892595 DOI: 10.1074/jbc.ra117.001379] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 02/01/2018] [Indexed: 12/30/2022] Open
Abstract
From unicellular to multicellular organisms, cell-cycle progression is tightly coupled to biosynthetic and bioenergetic demands. Accumulating evidence has demonstrated the G1/S-phase transition as a key checkpoint where cells respond to their metabolic status and commit to replicating the genome. However, the mechanism underlying the coordination of metabolism and the G2/M-phase transition in mammalian cells remains unclear. Here, we show that the activation of AMP-activated protein kinase (AMPK), a highly conserved cellular energy sensor, significantly delays mitosis entry. The cell-cycle G2/M-phase transition is controlled by mitotic cyclin-dependent kinase complex (CDC2-cyclin B), which is inactivated by WEE1 family protein kinases and activated by the opposing phosphatase CDC25C. AMPK directly phosphorylates CDC25C on serine 216, a well-conserved inhibitory phosphorylation event, which has been shown to mediate DNA damage–induced G2-phase arrest. The acute induction of CDC25C or suppression of WEE1 partially restores mitosis entry in the context of AMPK activation. These findings suggest that AMPK-dependent phosphorylation of CDC25C orchestrates a metabolic checkpoint for the cell-cycle G2/M-phase transition.
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Affiliation(s)
- Yuqing Shen
- From the Center for Childhood Cancer and Blood Diseases, Hematology/Oncology and BMT, Research Institute at Nationwide Children's Hospital, Ohio State University, Columbus, Ohio 43205 and.,the Department of Microbiology and Immunology, Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, Medical School, Southeast University, Nanjing 210009, China
| | - John William Sherman
- From the Center for Childhood Cancer and Blood Diseases, Hematology/Oncology and BMT, Research Institute at Nationwide Children's Hospital, Ohio State University, Columbus, Ohio 43205 and
| | - Xuyong Chen
- From the Center for Childhood Cancer and Blood Diseases, Hematology/Oncology and BMT, Research Institute at Nationwide Children's Hospital, Ohio State University, Columbus, Ohio 43205 and
| | - Ruoning Wang
- From the Center for Childhood Cancer and Blood Diseases, Hematology/Oncology and BMT, Research Institute at Nationwide Children's Hospital, Ohio State University, Columbus, Ohio 43205 and
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32
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Hardie DG. Keeping the home fires burning: AMP-activated protein kinase. J R Soc Interface 2018; 15:20170774. [PMID: 29343628 PMCID: PMC5805978 DOI: 10.1098/rsif.2017.0774] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 12/11/2017] [Indexed: 12/20/2022] Open
Abstract
Living cells obtain energy either by oxidizing reduced compounds of organic or mineral origin or by absorbing light. Whichever energy source is used, some of the energy released is conserved by converting adenosine diphosphate (ADP) to adenosine triphosphate (ATP), which are analogous to the chemicals in a rechargeable battery. The energy released by the conversion of ATP back to ADP is used to drive most energy-requiring processes, including cell growth, cell division, communication and movement. It is clearly essential to life that the production and consumption of ATP are always maintained in balance, and the AMP-activated protein kinase (AMPK) is one of the key cellular regulatory systems that ensures this. In eukaryotic cells (cells with nuclei and other internal membrane-bound structures, including human cells), most ATP is produced in mitochondria, which are thought to have been derived by the engulfment of oxidative bacteria by a host cell not previously able to use molecular oxygen. AMPK is activated by increasing AMP or ADP (AMP being generated from ADP whenever ADP rises) coupled with falling ATP. Relatives of AMPK are found in essentially all eukaryotes, and it may have evolved to allow the host cell to monitor the output of the newly acquired mitochondria and step their ATP production up or down according to the demand. Structural studies have illuminated how AMPK achieves the task of detecting small changes in AMP and ADP, despite the presence of much higher concentrations of ATP. Recently, it has been shown that AMPK can also sense the availability of glucose, the primary carbon source for most eukaryotic cells, via a mechanism independent of changes in AMP or ADP. Once activated by energy imbalance or glucose lack, AMPK modifies many target proteins by transferring phosphate groups to them from ATP. By this means, numerous ATP-producing processes are switched on (including the production of new mitochondria) and ATP-consuming processes are switched off, thus restoring energy homeostasis. Drugs that modulate AMPK have great potential in the treatment of metabolic disorders such as obesity and Type 2 diabetes, and even cancer. Indeed, some existing drugs such as metformin and aspirin, which were derived from traditional herbal remedies, appear to work, in part, by activating AMPK.
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Affiliation(s)
- D Grahame Hardie
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
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33
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Abstract
Orthologues of AMP-activated protein kinase (AMPK) occur in essentially all eukaryotes as heterotrimeric complexes comprising catalytic α subunits and regulatory β and γ subunits. The canonical role of AMPK is as an energy sensor, monitoring levels of the nucleotides AMP, ADP, and ATP that bind competitively to the γ subunit. Once activated, AMPK acts to restore energy homeostasis by switching on alternate ATP-generating catabolic pathways while switching off ATP-consuming anabolic pathways. However, its ancestral role in unicellular eukaryotes may have been in sensing of glucose rather than energy. In this article, we discuss a few interesting recent developments in the AMPK field. Firstly, we review recent findings on the canonical pathway by which AMPK is regulated by adenine nucleotides. Secondly, AMPK is now known to be activated in mammalian cells by glucose starvation by a mechanism that occurs in the absence of changes in adenine nucleotides, involving the formation of complexes with Axin and LKB1 on the surface of the lysosome. Thirdly, in addition to containing the nucleotide-binding sites on the γ subunits, AMPK heterotrimers contain a site for binding of allosteric activators termed the allosteric drug and metabolite (ADaM) site. A large number of synthetic activators, some of which show promise as hypoglycaemic agents in pre-clinical studies, have now been shown to bind there. Fourthly, some kinase inhibitors paradoxically activate AMPK, including one (SU6656) that binds in the catalytic site. Finally, although downstream targets originally identified for AMPK were mainly concerned with metabolism, recently identified targets have roles in such diverse areas as mitochondrial fission, integrity of epithelial cell layers, and angiogenesis.
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Affiliation(s)
- David Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Sheng-Cai Lin
- State Key Laboratory of Cellular Stress Biology, Xiamen University, Xiang’an Campus, Xiamen, China
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Ross FA, Hawley SA, Auciello FR, Gowans GJ, Atrih A, Lamont DJ, Hardie DG. Mechanisms of Paradoxical Activation of AMPK by the Kinase Inhibitors SU6656 and Sorafenib. Cell Chem Biol 2017; 24:813-824.e4. [PMID: 28625738 PMCID: PMC5522529 DOI: 10.1016/j.chembiol.2017.05.021] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 02/28/2017] [Accepted: 05/17/2017] [Indexed: 02/07/2023]
Abstract
SU6656, a Src kinase inhibitor, was reported to increase fat oxidation and reduce body weight in mice, with proposed mechanisms involving AMP-activated protein kinase (AMPK) activation via inhibition of phosphorylation of either LKB1 or AMPK by the Src kinase, Fyn. However, we report that AMPK activation by SU6656 is independent of Src kinases or tyrosine phosphorylation of LKB1 or AMPK and is not due to decreased cellular energy status or binding at the ADaM site on AMPK. SU6656 is a potent AMPK inhibitor, yet binding at the catalytic site paradoxically promotes phosphorylation of Thr172 by LKB1. This would enhance phosphorylation of downstream targets provided the lifetime of Thr172 phosphorylation was sufficient to allow dissociation of the inhibitor and subsequent catalysis prior to its dephosphorylation. By contrast, sorafenib, a kinase inhibitor in clinical use, activates AMPK indirectly by inhibiting mitochondrial metabolism and increasing cellular AMP:ADP and/or ADP:ATP ratios.
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Affiliation(s)
- Fiona A Ross
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Simon A Hawley
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - F Romana Auciello
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Graeme J Gowans
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Abdelmadjid Atrih
- Fingerprints Proteomics Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Douglas J Lamont
- Fingerprints Proteomics Facility, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - D Grahame Hardie
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
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Ward J, Reyes AR, Kurumbail RG. Allosteric Modulation of AMPK Enzymatic Activity: In Vitro Characterization. Methods Enzymol 2016; 587:481-509. [PMID: 28253974 DOI: 10.1016/bs.mie.2016.10.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
AMP-activated protein kinase (AMPK) is a heterotrimeric serine/threonine protein kinase found in nearly all eukaryotes that functions as a master energy sensor in cells. During times of cell stress and changes in the AMP/ATP ratio, AMPK becomes activated and phosphorylates a multitude of protein substrates involved in various cellular processes such as metabolism, cell growth and autophagy. The endogenous ligand AMP is known to bind to the γ-subunit and activates the enzyme via three distinct mechanisms (1) enhancing phosphorylation by upstream kinases of Thr172 in the activation loop (a site critical for AMPK activity), (2) protecting Thr172 from dephosphorylation by phosphatases, and (3) allosteric activation of the kinase activity. Given the important regulatory role for AMPK in various cellular processes and the multiple known modes of activation, there is great interest in identifying small-molecule activators of this kinase and a need for assays to identify and characterize compounds. Here we describe several assay formats that have been used for identifying and characterizing small-molecule AMPK activators.
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Affiliation(s)
- J Ward
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, United States.
| | - A R Reyes
- Cardiovascular and Metabolic Diseases Research Unit, Pfizer Worldwide Research and Development, Cambridge, MA, United States
| | - R G Kurumbail
- Worldwide Medicinal Chemistry, Pfizer Worldwide Research and Development, Groton, CT, United States
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Rutherford C, Speirs C, Williams JJL, Ewart MA, Mancini SJ, Hawley SA, Delles C, Viollet B, Costa-Pereira AP, Baillie GS, Salt IP, Palmer TM. Phosphorylation of Janus kinase 1 (JAK1) by AMP-activated protein kinase (AMPK) links energy sensing to anti-inflammatory signaling. Sci Signal 2016; 9:ra109. [DOI: 10.1126/scisignal.aaf8566] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Lee TK, Park C, Jeong SJ, Jeong MJ, Kim GY, Kim WJ, Choi YH. Sanguinarine Induces Apoptosis of Human Oral Squamous Cell Carcinoma KB Cells via Inactivation of the PI3K/Akt Signaling Pathway. Drug Dev Res 2016; 77:227-40. [PMID: 27363951 DOI: 10.1002/ddr.21315] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 05/25/2016] [Indexed: 01/16/2023]
Abstract
Preclinical Research Sanguinarine, an alkaloid isolated from the root of Sanguinaria canadensis and other plants of the Papaveraceae family, selectively induces apoptotic cell death in a variety of human cancer cells, but its mechanism of action requires further elaboration. The present study investigated the pro-apoptotic effects of sanguinarine in human oral squamous cell carcinoma KB cells. Sanguinarine treatment increased DR5/TRAILR2 (death receptor 5/TRAIL receptor 2) expression and enhanced the activation of caspase-8 and cleavage of its substrate, Bid. Sanguinarine also induced the mitochondrial translocation of pro-apoptotic Bax, mitochondrial dysfunction, cytochrome c release to the cytosol, and activation of caspase-9 and -3. However, a pan-caspase inhibitor, z-VAD-fmk, reversed the growth inhibition and apoptosis induced by sanguinarine. Sanguinarine also suppressed the phosphorylation of phosphoinositide 3-kinase (PI3K) and Akt in KB cells, while co-treatment of cells with sanguinarine and a PI3K inhibitor revealed synergistic apoptotic effects. However, pharmacological inhibition of AMP-activated protein kinase and mitogen-activated protein kinases did not reduce or enhance sanguinarine-induced growth inhibition and apoptosis. Collectively, these findings indicate that the pro-apoptotic effects of sanguinarine in KB cells may be regulated by a caspase-dependent cascade via activation of both intrinsic and extrinsic signaling pathways and inactivation of PI3K/Akt signaling. Drug Dev Res 77 : 227-240, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Tae Kyung Lee
- Department of Biology, New York University, New York, NY, 10012, USA
| | - Cheol Park
- Department of Molecular Biology, College of Natural Sciences and Human Ecology, Dongeui University, Busan, 614-714, South Korea
| | - Soon-Jeong Jeong
- Department of Dental Hygiene, College of Health Sciences, Youngsan University, Yangsan, 626-790, South Korea
| | - Moon-Jin Jeong
- Department of Oral Histology and Developmental Biology, School of Dentistry, Chosun University, Gwangju, 501-759, South Korea
| | - Gi-Young Kim
- Laboratory of Immunobiology, Department of Marine Life Sciences, Jeju National University, Jeju, 690-756, South Korea
| | - Wun-Jae Kim
- Department of Urology, Chungbuk National University, College of Medicine and Institute for Tumor Research, Cheongju, 28644, South Korea
| | - Yung Hyun Choi
- Anti-Aging Research Center, Dongeui University, Busan, 614-714, South Korea.,Department of Biochemistry, Dongeui University College of Korean Medicine, Busan, 614-714, South Korea
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Richards L, Li M, van Esch B, Garssen J, Folkerts G. The effects of short-chain fatty acids on the cardiovascular system. PHARMANUTRITION 2016. [DOI: 10.1016/j.phanu.2016.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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39
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Hardie DG, Schaffer BE, Brunet A. AMPK: An Energy-Sensing Pathway with Multiple Inputs and Outputs. Trends Cell Biol 2016; 26:190-201. [PMID: 26616193 PMCID: PMC5881568 DOI: 10.1016/j.tcb.2015.10.013] [Citation(s) in RCA: 624] [Impact Index Per Article: 78.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/15/2015] [Accepted: 10/22/2015] [Indexed: 12/20/2022]
Abstract
AMP-activated protein kinase (AMPK) is a key regulator of energy balance expressed ubiquitously in eukaryotic cells. Here we review the canonical adenine nucleotide-dependent mechanism that activates AMPK when cellular energy status is compromised, as well as other, noncanonical activation mechanisms. Once activated, AMPK acts to restore energy homeostasis by promoting catabolic pathways, resulting in ATP generation, and inhibiting anabolic pathways that consume ATP. We also review the various hypothesis-driven and unbiased approaches that have been used to identify AMPK substrates and have revealed substrates involved in both metabolic and non-metabolic processes. We particularly focus on methods for identifying the AMPK target recognition motif and how it can be used to predict new substrates.
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Affiliation(s)
- D Grahame Hardie
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
| | - Bethany E Schaffer
- Department of Genetics and the Cancer Biology Program, Stanford University, 300 Pasteur Drive, Stanford, CA, USA
| | - Anne Brunet
- Department of Genetics and the Cancer Biology Program, Stanford University, 300 Pasteur Drive, Stanford, CA, USA
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Toyama EQ, Herzig S, Courchet J, Lewis TL, Losón OC, Hellberg K, Young NP, Chen H, Polleux F, Chan DC, Shaw RJ. Metabolism. AMP-activated protein kinase mediates mitochondrial fission in response to energy stress. Science 2016; 351:275-281. [PMID: 26816379 DOI: 10.1126/science.aab4138] [Citation(s) in RCA: 777] [Impact Index Per Article: 97.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mitochondria undergo fragmentation in response to electron transport chain (ETC) poisons and mitochondrial DNA-linked disease mutations, yet how these stimuli mechanistically connect to the mitochondrial fission and fusion machinery is poorly understood. We found that the energy-sensing adenosine monophosphate (AMP)-activated protein kinase (AMPK) is genetically required for cells to undergo rapid mitochondrial fragmentation after treatment with ETC inhibitors. Moreover, direct pharmacological activation of AMPK was sufficient to rapidly promote mitochondrial fragmentation even in the absence of mitochondrial stress. A screen for substrates of AMPK identified mitochondrial fission factor (MFF), a mitochondrial outer-membrane receptor for DRP1, the cytoplasmic guanosine triphosphatase that catalyzes mitochondrial fission. Nonphosphorylatable and phosphomimetic alleles of the AMPK sites in MFF revealed that it is a key effector of AMPK-mediated mitochondrial fission.
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Affiliation(s)
- Erin Quan Toyama
- Molecular and Cell Biology Laboratory and Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sébastien Herzig
- Molecular and Cell Biology Laboratory and Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Julien Courchet
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute and Kavli Institute for Brain Science, Columbia University, New York, NY 10032, USA
| | - Tommy L Lewis
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute and Kavli Institute for Brain Science, Columbia University, New York, NY 10032, USA
| | - Oliver C Losón
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Kristina Hellberg
- Molecular and Cell Biology Laboratory and Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Nathan P Young
- Molecular and Cell Biology Laboratory and Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Hsiuchen Chen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Franck Polleux
- Department of Neuroscience, Zuckerman Mind Brain Behavior Institute and Kavli Institute for Brain Science, Columbia University, New York, NY 10032, USA
| | - David C Chan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Reuben J Shaw
- Molecular and Cell Biology Laboratory and Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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PARK CHEOL, JEONG JISUK, JEONG JINWOO, KIM YONGJOO, JUNG YEONKWON, GO GEUNBAE, KIM SUNGOK, KIM GIYOUNG, HONG SUHYUN, YOO YOUNGHYUN, CHOI YUNGHYUN. Ethanol extract of Kalopanax septemlobus leaf induces caspase-dependent apoptosis associated with activation of AMPK in human hepatocellular carcinoma cells. Int J Oncol 2015; 48:261-70. [DOI: 10.3892/ijo.2015.3233] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 10/21/2015] [Indexed: 11/06/2022] Open
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Schaffer BE, Levin RS, Hertz NT, Maures TJ, Schoof ML, Hollstein PE, Benayoun BA, Banko MR, Shaw RJ, Shokat KM, Brunet A. Identification of AMPK Phosphorylation Sites Reveals a Network of Proteins Involved in Cell Invasion and Facilitates Large-Scale Substrate Prediction. Cell Metab 2015; 22:907-21. [PMID: 26456332 PMCID: PMC4635044 DOI: 10.1016/j.cmet.2015.09.009] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Revised: 07/28/2015] [Accepted: 09/08/2015] [Indexed: 12/22/2022]
Abstract
AMP-activated protein kinase (AMPK) is a central energy gauge that regulates metabolism and has been increasingly involved in non-metabolic processes and diseases. However, AMPK's direct substrates in non-metabolic contexts are largely unknown. To better understand the AMPK network, we use a chemical genetics screen coupled to a peptide capture approach in whole cells, resulting in identification of direct AMPK phosphorylation sites. Interestingly, the high-confidence AMPK substrates contain many proteins involved in cell motility, adhesion, and invasion. AMPK phosphorylation of the RHOA guanine nucleotide exchange factor NET1A inhibits extracellular matrix degradation, an early step in cell invasion. The identification of direct AMPK phosphorylation sites also facilitates large-scale prediction of AMPK substrates. We provide an AMPK motif matrix and a pipeline to predict additional AMPK substrates from quantitative phosphoproteomics datasets. As AMPK is emerging as a critical node in aging and pathological processes, our study identifies potential targets for therapeutic strategies.
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Affiliation(s)
- Bethany E Schaffer
- Cancer Biology Program, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Rebecca S Levin
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA
| | - Nicholas T Hertz
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA
| | - Travis J Maures
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Michael L Schoof
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Pablo E Hollstein
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | | | - Max R Banko
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Reuben J Shaw
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Kevan M Shokat
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, CA 94158, USA
| | - Anne Brunet
- Cancer Biology Program, Stanford University, Stanford, CA 94305, USA; Department of Genetics, Stanford University, Stanford, CA 94305, USA; Glenn Laboratories for the Biology of Aging, Stanford, CA 94305, USA.
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Dinkova-Kostova AT, Abramov AY. The emerging role of Nrf2 in mitochondrial function. Free Radic Biol Med 2015; 88:179-188. [PMID: 25975984 PMCID: PMC4726722 DOI: 10.1016/j.freeradbiomed.2015.04.036] [Citation(s) in RCA: 669] [Impact Index Per Article: 74.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/28/2015] [Accepted: 04/30/2015] [Indexed: 12/30/2022]
Abstract
The transcription factor NF-E2 p45-related factor 2 (Nrf2; gene name NFE2L2) allows adaptation and survival under conditions of stress by regulating the gene expression of diverse networks of cytoprotective proteins, including antioxidant, anti-inflammatory, and detoxification enzymes as well as proteins that assist in the repair or removal of damaged macromolecules. Nrf2 has a crucial role in the maintenance of cellular redox homeostasis by regulating the biosynthesis, utilization, and regeneration of glutathione, thioredoxin, and NADPH and by controlling the production of reactive oxygen species by mitochondria and NADPH oxidase. Under homeostatic conditions, Nrf2 affects the mitochondrial membrane potential, fatty acid oxidation, availability of substrates (NADH and FADH2/succinate) for respiration, and ATP synthesis. Under conditions of stress or growth factor stimulation, activation of Nrf2 counteracts the increased reactive oxygen species production in mitochondria via transcriptional upregulation of uncoupling protein 3 and influences mitochondrial biogenesis by maintaining the levels of nuclear respiratory factor 1 and peroxisome proliferator-activated receptor γ coactivator 1α, as well as by promoting purine nucleotide biosynthesis. Pharmacological Nrf2 activators, such as the naturally occurring isothiocyanate sulforaphane, inhibit oxidant-mediated opening of the mitochondrial permeability transition pore and mitochondrial swelling. Curiously, a synthetic 1,4-diphenyl-1,2,3-triazole compound, originally designed as an Nrf2 activator, was found to promote mitophagy, thereby contributing to the overall mitochondrial homeostasis. Thus, Nrf2 is a prominent player in supporting the structural and functional integrity of the mitochondria, and this role is particularly crucial under conditions of stress.
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Affiliation(s)
- Albena T Dinkova-Kostova
- Jacqui Wood Cancer Centre, Division of Cancer Research, Medical Research Institute, University of Dundee, Dundee DD1 9SY, Scotland, UK; Departments of Medicine and Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Andrey Y Abramov
- Department of Molecular Neuroscience, University College London Institute of Neurology, London WC1N 3BG, UK.
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44
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Iurlaro R, León-Annicchiarico CL, Muñoz-Pinedo C. Regulation of cancer metabolism by oncogenes and tumor suppressors. Methods Enzymol 2015; 542:59-80. [PMID: 24862260 DOI: 10.1016/b978-0-12-416618-9.00003-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell proliferation requires the coordination of multiple signaling pathways as well as the provision of metabolic substrates. Nutrients are required to generate such building blocks and their form of utilization differs to significant extents between malignant tissues and their nontransformed counterparts. Thus, oncogenes and tumor suppressor genes regulate the proliferation of cancer cells also by controlling their metabolism. Here, we discuss the central anabolic functions of the signaling pathways emanating from mammalian target of rapamycin, MYC, and hypoxia-inducible factor-1. Moreover, we analyze how oncogenic proteins like phosphoinositide-3-kinase, AKT, and RAS, tumor suppressors such as phosphatase and tensin homolog, retinoblastoma, and p53, as well as other factors associated with the proliferation or survival of cancer cells, such as NF-κB, regulate cellular metabolism.
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Affiliation(s)
- Raffaella Iurlaro
- Cell Death Regulation Group, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | | | - Cristina Muñoz-Pinedo
- Cell Death Regulation Group, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain.
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45
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Ducommun S, Deak M, Sumpton D, Ford RJ, Núñez Galindo A, Kussmann M, Viollet B, Steinberg GR, Foretz M, Dayon L, Morrice NA, Sakamoto K. Motif affinity and mass spectrometry proteomic approach for the discovery of cellular AMPK targets: Identification of mitochondrial fission factor as a new AMPK substrate. Cell Signal 2015; 27:978-88. [DOI: 10.1016/j.cellsig.2015.02.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 02/08/2015] [Indexed: 11/15/2022]
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46
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Alenazi FSH, Ibrahim BA, Briski KP. Estradiol Regulates Dorsal Vagal Complex Signal Transduction Pathway Transcriptional Reactivity to the AMPK Activator 5-Aminoimidazole-4-Carboxamide-Riboside (AICAR). J Mol Neurosci 2015; 56:907-916. [PMID: 25796381 DOI: 10.1007/s12031-015-0541-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 03/06/2015] [Indexed: 02/04/2023]
Abstract
The ovarian hormone estradiol (E) regulates effects of hindbrain adenosine 5'-monophosphate-activated protein kinase (AMPK) on caudal dorsal vagal complex (cDVC) neuron genomic activation and systemic glucostasis. The present study examined the hypothesis that cDVC signal transduction pathways exhibit distinctive E-dependent reactivity to activation of this sensor. RT-PCR microarray analysis was performed on RNA extracted from the cDVC of E- or oil (O)-implanted ovariectomized (OVX) adult female rats injected into the caudal fourth ventricle with the AMP mimetic 5-aminoimidazole-4-carboxamide-riboside (AICAR) (A) or saline (S). Microarray results show that the majority of marker genes differentially expressed in the E/S versus O/S cDVC were upregulated, as only myc (TGFβ; WNT pathways), bcl2 (Hedgehog pathway), and serpine (hypoxia pathway) mRNA profiles were downregulated by E. Several JAK/STAT and NFκB signaling pathway marker gene profiles were upregulated in O/A but unchanged in E/A; additional NFκB genes were inhibited by A in E but not O. Hypoxia and p53 pathways contain genes that were inhibited or stimulated in O/A, but unaltered in E/A. Conversely, TGFβ, p53, and NOTCH pathways each contained marker genes that were correspondingly modified or maintained in E/A versus O/A. Moreover, several oxidative stress pathway genes were suppressed in O/A while elevated or unchanged in E/A. Hedgehog, PPAR, and WNT signaling pathways were characterized by numerous examples of A-induced reversal of E augmentation of marker gene expression coinciding with opposite or no drug effects in O. Data presented here demonstrate that E exerts distinctive effects on cDVC signal transduction pathway marker gene reactivity to activated AMPK. Further research is needed to determine if observed changes in signal pathway marker gene transcription correlate with adjustments in gene product protein expression, and to characterize the role of aforementioned signaling pathways in E-sensitive cellular and systemic responses to hindbrain AMPK activation.
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Affiliation(s)
- Fahaad S H Alenazi
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA, 71201, USA
| | - Baher A Ibrahim
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA, 71201, USA
| | - Karen P Briski
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, 356 Bienville Building, 1800 Bienville Drive, Monroe, LA, 71201, USA.
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Abstract
The AMP-activated protein kinase (AMPK) is a sensor of cellular energy and nutrient status, expressed almost universally in eukaryotes as heterotrimeric complexes comprising catalytic (α) and regulatory (β and γ) subunits. Along with the mechanistic target of rapamycin complex-1 (mTORC1), AMPK may have been one of the earliest signaling pathways to have arisen during eukaryotic evolution. Recent crystal structures have provided insights into the mechanisms by which AMPK is regulated by phosphorylation and allosteric activators. Another recent development has been the realization that activation of AMPK by the upstream kinase LKB1 may primarily occur not in the cytoplasm, but at the surface of the lysosome, where AMPK and mTORC1 are regulated in a reciprocal manner by the availability of nutrients. It is also becoming clear that there is a substantial amount of crosstalk between the AMPK pathway and other signaling pathways that promote cell growth and proliferation, and this will be discussed.
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Affiliation(s)
- D Grahame Hardie
- Division of Cell Signalling & Immunology, College of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH Scotland, UK.
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48
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Grahame Hardie D. AMP-activated protein kinase: a key regulator of energy balance with many roles in human disease. J Intern Med 2014; 276:543-59. [PMID: 24824502 PMCID: PMC5705060 DOI: 10.1111/joim.12268] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status that regulates cellular and whole-body energy balance. A recently reported crystal structure has illuminated the complex regulatory mechanisms by which AMP and ADP cause activation of AMPK, involving phosphorylation by the upstream kinase LKB1. Once activated by falling cellular energy status, AMPK activates catabolic pathways that generate ATP whilst inhibiting anabolic pathways and other cellular processes that consume ATP. A role of AMPK is implicated in many human diseases. Mutations in the γ2 subunit cause heart disease due to excessive glycogen storage in cardiac myocytes, leading to ventricular pre-excitation. AMPK-activating drugs reverse many of the metabolic defects associated with insulin resistance, and recent findings suggest that the insulin-sensitizing effects of the widely used antidiabetic drug metformin are mediated by AMPK. The upstream kinase LKB1 is a tumour suppressor, and AMPK may exert many of its antitumour effects. AMPK activation promotes the oxidative metabolism typical of quiescent cells, rather than the aerobic glycolysis observed in tumour cells and cells involved in inflammation, explaining in part why AMPK activators have both antitumour and anti-inflammatory effects. Salicylate (the major in vivo metabolite of aspirin) activates AMPK, and this could be responsible for at least some of the anticancer and anti-inflammatory effects of aspirin. In addition to metformin and salicylates, novel drugs that modulate AMPK are likely to enter clinical trials soon. Finally, AMPK may be involved in viral infection: downregulation of AMPK during hepatitis C virus infection appears to be essential for efficient viral replication.
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Affiliation(s)
- D Grahame Hardie
- Division of Cell Signalling and Immunology, College of Life Sciences, University of Dundee, Scotland, UK
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DeRan M, Yang J, Shen CH, Peters EC, Fitamant J, Chan P, Hsieh M, Zhu S, Asara JM, Zheng B, Bardeesy N, Liu J, Wu X. Energy stress regulates hippo-YAP signaling involving AMPK-mediated regulation of angiomotin-like 1 protein. Cell Rep 2014; 9:495-503. [PMID: 25373897 DOI: 10.1016/j.celrep.2014.09.036] [Citation(s) in RCA: 234] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Revised: 08/18/2014] [Accepted: 09/18/2014] [Indexed: 12/25/2022] Open
Abstract
Hippo signaling is a tumor-suppressor pathway involved in organ size control and tumorigenesis through the inhibition of YAP and TAZ. Here, we show that energy stress induces YAP cytoplasmic retention and S127 phosphorylation and inhibits YAP transcriptional activity and YAP-dependent transformation. These effects require the central metabolic sensor AMP-activated protein kinase (AMPK) and the upstream Hippo pathway components Lats1/Lats2 and angiomotin-like 1 (AMOTL1). Furthermore, we show that AMPK directly phosphorylates S793 of AMOTL1. AMPK activation stabilizes and increases AMOTL1 steady-state protein levels, contributing to YAP inhibition. The phosphorylation-deficient S793Ala mutant of AMOTL1 showed a shorter half-life and conferred resistance to energy-stress-induced YAP inhibition. Our findings link energy sensing to the Hippo-YAP pathway and suggest that YAP may integrate spatial (contact inhibition), mechanical, and metabolic signals to control cellular proliferation and survival.
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Affiliation(s)
- Michael DeRan
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Jiayi Yang
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Che-Hung Shen
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Eric C Peters
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Julien Fitamant
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA 02114, USA
| | - Puiyee Chan
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Mindy Hsieh
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Shunying Zhu
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - John M Asara
- Division of Signal Transduction, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Bin Zheng
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Nabeel Bardeesy
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA 02114, USA
| | - Jun Liu
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121, USA
| | - Xu Wu
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
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Rana S, Blowers EC, Natarajan A. Small molecule adenosine 5'-monophosphate activated protein kinase (AMPK) modulators and human diseases. J Med Chem 2014; 58:2-29. [PMID: 25122135 DOI: 10.1021/jm401994c] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Adenosine 5'-monophosphate activated protein kinase (AMPK) is a master sensor of cellular energy status that plays a key role in the regulation of whole-body energy homeostasis. AMPK is a serine/threonine kinase that is activated by upstream kinases LKB1, CaMKKβ, and Tak1, among others. AMPK exists as αβγ trimeric complexes that are allosterically regulated by AMP, ADP, and ATP. Dysregulation of AMPK has been implicated in a number of metabolic diseases including type 2 diabetes mellitus and obesity. Recent studies have associated roles of AMPK with the development of cancer and neurological disorders, making it a potential therapeutic target to treat human diseases. This review focuses on the structure and function of AMPK, its role in human diseases, and its direct substrates and provides a brief synopsis of key AMPK modulators and their relevance in human diseases.
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Affiliation(s)
- Sandeep Rana
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center , Omaha, Nebraska 68198-6805, United States
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