1
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Ferrarone JR, Thomas J, Unni AM, Zheng Y, Nagiec MJ, Gardner EE, Mashadova O, Li K, Koundouros N, Montalbano A, Mustafa M, Cantley LC, Blenis J, Sanjana NE, Varmus H. Genome-wide CRISPR screens in spheroid culture reveal that the tumor suppressor LKB1 inhibits growth via the PIKFYVE lipid kinase. Proc Natl Acad Sci U S A 2024; 121:e2403685121. [PMID: 38743625 PMCID: PMC11127050 DOI: 10.1073/pnas.2403685121] [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: 02/22/2024] [Accepted: 04/19/2024] [Indexed: 05/16/2024] Open
Abstract
The tumor suppressor LKB1 is a serine/threonine protein kinase that is frequently mutated in human lung adenocarcinoma (LUAD). LKB1 regulates a complex signaling network that is known to control cell polarity and metabolism; however, the pathways that mediate the tumor-suppressive activity of LKB1 are incompletely defined. To identify mechanisms of LKB1-mediated growth suppression, we developed a spheroid-based cell culture assay to study LKB1-dependent growth. We then performed genome-wide CRISPR screens in spheroidal culture and found that LKB1 suppresses growth, in part, by activating the PIKFYVE lipid kinase. Finally, we used chemical inhibitors and a pH-sensitive reporter to determine that LKB1 impairs growth by promoting the internalization of wild-type EGFR in a PIKFYVE-dependent manner.
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Affiliation(s)
- John R. Ferrarone
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medicine, New York, NY10021
| | - Jerin Thomas
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
| | - Arun M. Unni
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
| | - Yuxiang Zheng
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
| | - Michal J. Nagiec
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
- Department of Pharmacology, Weill Cornell Medicine, New York, NY10021
| | - Eric E. Gardner
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
| | | | - Kate Li
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
| | - Nikos Koundouros
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
- Department of Pharmacology, Weill Cornell Medicine, New York, NY10021
| | - Antonino Montalbano
- New York Genome Center, New York, NY10013
- Department of Biology, New York University, New York, NY10003
| | - Meer Mustafa
- New York Genome Center, New York, NY10013
- Department of Biology, New York University, New York, NY10003
| | - Lewis C. Cantley
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
- Department of Medicine, Weill Cornell Medicine, New York, NY10021
| | - John Blenis
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
- Department of Pharmacology, Weill Cornell Medicine, New York, NY10021
| | - Neville E. Sanjana
- New York Genome Center, New York, NY10013
- Department of Biology, New York University, New York, NY10003
| | - Harold Varmus
- Meyer Cancer Center, Weill Cornell Medicine, New York, NY10021
- Department of Medicine, Weill Cornell Medicine, New York, NY10021
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2
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Ferrarone JR, Thomas J, Unni AM, Zheng Y, Nagiec MJ, Gardner EE, Mashadova O, Li K, Koundouros N, Montalbano A, Mustafa M, Cantley LC, Blenis J, Sanjana NE, Varmus H. LKB1 suppresses growth and promotes the internalization of EGFR through the PIKFYVE lipid kinase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.19.563158. [PMID: 37904985 PMCID: PMC10614957 DOI: 10.1101/2023.10.19.563158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
The tumor suppressor LKB1 is a serine/threonine protein kinase that is frequently mutated in human lung adenocarcinoma (LUAD). LKB1 regulates a complex signaling network that is known to control cell polarity and metabolism; however, the pathways that mediate the tumor suppressive activity of LKB1 are incompletely defined. To identify mechanisms of LKB1- mediated growth suppression we developed a spheroid-based cell culture assay to study LKB1- dependent growth. Using this assay, along with genome-wide CRISPR screens and validation with orthogonal methods, we discovered that LKB1 suppresses growth, in part, by activating the PIKFYVE lipid kinase, which promotes the internalization of wild-type EGFR. Our findings reveal a new mechanism of regulation of EGFR, which may have implications for the treatment of LKB1 -mutant LUAD.
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3
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Campbell MD, Djukovic D, Raftery D, Marcinek DJ. Age-related changes of skeletal muscle metabolic response to contraction are also sex-dependent. J Physiol 2023:10.1113/JP285124. [PMID: 37742081 PMCID: PMC10959763 DOI: 10.1113/jp285124] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/08/2023] [Indexed: 09/25/2023] Open
Abstract
Mitochondria adapt to increased energy demands during muscle contraction by acutely altering metabolite fluxes and substrate oxidation. With age, an impaired mitochondrial metabolic response may contribute to reduced exercise tolerance and decreased skeletal muscle mass, specific force, increased overall fatty depositions in the skeletal muscle, frailty and depressed energy maintenance. We hypothesized that elevated energy stress in mitochondria with age alters the capacity of mitochondria to utilize different substrates following muscle contraction. To test this hypothesis, we used in vivo electrical stimulation to simulate high-intensity intervals (HII) or low intensity steady-state (LISS) exercise in young (5-7 months) and aged (27-29 months) male and female mice to characterize effects of age and sex on mitochondrial substrate utilization in skeletal muscle following contraction. Mitochondrial respiration using glutamate decreased in aged males following HII and glutamate oxidation was inhibited following HII in both the contracted and non-stimulated muscle of aged female muscle. Analyses of the muscle metabolome of female mice indicated that changes in metabolic pathways induced by HII and LISS contractions in young muscle are absent in aged muscle. To test improved mitochondrial function on substrate utilization following HII, we treated aged females with elamipretide (ELAM), a mitochondrially-targeted peptide shown to improve mitochondrial bioenergetics and restore redox status in aged muscle. ELAM removed inhibition of glutamate oxidation and showed increased metabolic pathway changes following HII, suggesting rescuing redox status and improving bioenergetic function in mitochondria from aged muscle increases glutamate utilization and enhances the metabolic response to muscle contraction in aged muscle. KEY POINTS: Acute local contraction of gastrocnemius can systemically alter mitochondrial respiration in non-stimulated muscle. Age-related changes in mitochondrial respiration using glutamate or palmitoyl carnitine following contraction are sex-dependent. Respiration using glutamate after high-intensity contraction is inhibited in aged female muscle. Metabolite level and pathway changes following muscle contraction decrease with age in female mice. Treatment with the mitochondrially-targeted peptide elamipretide can partially rescue metabolite response to muscle contraction.
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Affiliation(s)
| | - Danijel Djukovic
- Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
| | - Daniel Raftery
- Anesthesiology & Pain Medicine, University of Washington, Seattle, WA
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4
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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: 185] [Impact Index Per Article: 185.0] [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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5
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Wang H, Zhang J, Liu H, Wang M, Dong Y, Zhou Y, Wong SM, Xu K, Xu Q. A plant virus hijacks phosphatidylinositol-3,5-bisphosphate to escape autophagic degradation in its insect vector. Autophagy 2023; 19:1128-1143. [PMID: 36093594 PMCID: PMC10012956 DOI: 10.1080/15548627.2022.2116676] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 06/29/2022] [Accepted: 08/20/2022] [Indexed: 02/07/2023] Open
Abstract
Hosts can initiate macroautophagy/autophagy as an antiviral defense response, while viruses have developed multiple ways to evade the host autophagic degradation. However, little is known as to whether viruses can target lipids to subvert autophagic degradation. Here, we show that a low abundant signaling lipid, phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2), is required for rice black-streaked dwarf virus (RBSDV) to evade the autophagic degradation in the insect vector Laodelphax striatellus. RBSDV binds to PtdIns(3,5)P2 and elevates its level through its main capsid protein P10, leading to inhibited autophagy and promoted virus propagation. Furthermore, we show that PtdIns(3,5)P2 inhibits the autophagy pathway by preventing the fusion of autophagosomes and lysosomes through activation of Trpml (transient receptor potential cation channel, mucolipin), an effector of PtdIns(3,5)P2. These findings uncover a strategy whereby a plant virus hijacks PtdIns(3,5)P2 via its viral capsid protein to evade autophagic degradation and promote its survival in insects.
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Affiliation(s)
- Haitao Wang
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Jianhua Zhang
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Institute of Industrial Crops, Shandong Academy of Agricultural Sciences, Jinan, China
| | - Haoqiu Liu
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- National University of Singapore Research Institute, Suzhou, China
| | - Man Wang
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yan Dong
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yijun Zhou
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Sek-Man Wong
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- National University of Singapore Research Institute, Suzhou, China
| | - Kai Xu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qiufang Xu
- Institute of Plant Protection, Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- College of Life Sciences, Anhui Normal University, Wuhu, China
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6
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Stocks B, Zierath JR. Post-translational Modifications: The Signals at the Intersection of Exercise, Glucose Uptake, and Insulin Sensitivity. Endocr Rev 2022; 43:654-677. [PMID: 34730177 PMCID: PMC9277643 DOI: 10.1210/endrev/bnab038] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Indexed: 11/19/2022]
Abstract
Diabetes is a global epidemic, of which type 2 diabetes makes up the majority of cases. Nonetheless, for some individuals, type 2 diabetes is eminently preventable and treatable via lifestyle interventions. Glucose uptake into skeletal muscle increases during and in recovery from exercise, with exercise effective at controlling glucose homeostasis in individuals with type 2 diabetes. Furthermore, acute and chronic exercise sensitizes skeletal muscle to insulin. A complex network of signals converge and interact to regulate glucose metabolism and insulin sensitivity in response to exercise. Numerous forms of post-translational modifications (eg, phosphorylation, ubiquitination, acetylation, ribosylation, and more) are regulated by exercise. Here we review the current state of the art of the role of post-translational modifications in transducing exercise-induced signals to modulate glucose uptake and insulin sensitivity within skeletal muscle. Furthermore, we consider emerging evidence for noncanonical signaling in the control of glucose homeostasis and the potential for regulation by exercise. While exercise is clearly an effective intervention to reduce glycemia and improve insulin sensitivity, the insulin- and exercise-sensitive signaling networks orchestrating this biology are not fully clarified. Elucidation of the complex proteome-wide interactions between post-translational modifications and the associated functional implications will identify mechanisms by which exercise regulates glucose homeostasis and insulin sensitivity. In doing so, this knowledge should illuminate novel therapeutic targets to enhance insulin sensitivity for the clinical management of type 2 diabetes.
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Affiliation(s)
- Ben Stocks
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Juleen R Zierath
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.,Departments of Molecular Medicine and Surgery and Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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7
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Tu-Sekine B, Kim SF. The Inositol Phosphate System-A Coordinator of Metabolic Adaptability. Int J Mol Sci 2022; 23:6747. [PMID: 35743190 PMCID: PMC9223660 DOI: 10.3390/ijms23126747] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022] Open
Abstract
All cells rely on nutrients to supply energy and carbon building blocks to support cellular processes. Over time, eukaryotes have developed increasingly complex systems to integrate information about available nutrients with the internal state of energy stores to activate the necessary processes to meet the immediate and ongoing needs of the cell. One such system is the network of soluble and membrane-associated inositol phosphates that coordinate the cellular responses to nutrient uptake and utilization from growth factor signaling to energy homeostasis. In this review, we discuss the coordinated interactions of the inositol polyphosphates, inositol pyrophosphates, and phosphoinositides in major metabolic signaling pathways to illustrate the central importance of the inositol phosphate signaling network in nutrient responses.
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Affiliation(s)
- Becky Tu-Sekine
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University, Baltimore, MD 21224, USA;
| | - Sangwon F. Kim
- Department of Medicine and Neuroscience, Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA
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8
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Gu M, Wang Z, Feng F, Yang Y, Sun X, Yang D. Inhibition of PIKfyve Ameliorates the Proliferation and Migration of Vascular Smooth Muscle Cells and Vascular Intima Hyperplasia By Reducing mTORC1 Activity. J Cardiovasc Pharmacol 2022; 79:739-748. [PMID: 35275098 PMCID: PMC9067083 DOI: 10.1097/fjc.0000000000001243] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 02/06/2022] [Indexed: 02/07/2023]
Abstract
ABSTRACT This study was designed to investigate the role and mechanism of PIKfyve in the proliferation and migration of vascular smooth muscle cells (VSMCs) and vascular intima hyperplasia. We first observed increased protein levels of PIKfyve, phospho (p)-S6 Ribosomal Protein (S6)Ser235/236, p-4EBP1Thr37/46 in VSMCs after 24 hours of platelet-derived growth factor (PDGF)-BB treatment. By using cell counting kit-8 assay, Ki-67 immunofluorescence staining and wound healing assay, we found that PIKfyve inhibition ameliorated the enhanced activity of VSMC proliferation and migration induced by PDGF-BB. Silencing PIKfyve also suppressed the phosphorylation of S6 and 4EBP1 (2 major effectors of mammalian target of rapamycin complex 1), glucose consumption, activity of hexokinase, and LDH in PDGF-BB-challenged VSMCs. After rescuing the phosphorylation of S6 and 4EBP1 by silencing Tsc1, the suppressive effects of PIKfyve inhibition on glucose utilization, proliferation, and migration in VSMCs were abolished. The animal model of vascular restenosis was established in C57BL/6J mice by wire injury. We found the expression of PIKfyve was increased in carotid artery at day 28 after injury. Reducing the activity of PIKfyve alleviated vascular neointima hyperplasia after injury. In conclusion, targeting PIKfyve might be a novel effective method to reduce the proliferation and migration of VSMCs and vascular restenosis by affecting mammalian target of rapamycin complex 1-mediated glucose utilization.
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Affiliation(s)
- Min Gu
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Zhen Wang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Feifei Feng
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Yongjian Yang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Xiongshan Sun
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
| | - Dachun Yang
- Department of Cardiology, The General Hospital of Western Theater Command, Chengdu, Sichuan, China
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9
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McCarty MF. Nutraceutical and Dietary Strategies for Up-Regulating Macroautophagy. Int J Mol Sci 2022; 23:2054. [PMID: 35216170 PMCID: PMC8875972 DOI: 10.3390/ijms23042054] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/07/2022] [Accepted: 02/08/2022] [Indexed: 12/04/2022] Open
Abstract
Macroautophagy is a "cell cleansing" process that rids cells of protein aggregates and damaged organelles that may contribute to disease pathogenesis and the dysfunctions associated with aging. Measures which boost longevity and health span in rodents typically up-regulate macroautophagy, and it has often been suggested that safe strategies which can promote this process in humans may contribute to healthful aging. The kinase ULK1 serves as a trigger for autophagy initiation, and the transcription factors TFEB, FOXO1, ATF4 and CHOP promote expression of a number of proteins which mediate macroautophagy. Nutraceutical or dietary measures which stimulate AMPK, SIRT1, eIF5A, and that diminish the activities of AKT and mTORC1, can be expected to boost the activities of these pro-autophagic factors. The activity of AMPK can be stimulated with the phytochemical berberine. SIRT1 activation may be achieved with a range of agents, including ferulic acid, melatonin, urolithin A, N1-methylnicotinamide, nicotinamide riboside, and glucosamine; correction of ubiquinone deficiency may also be useful in this regard, as may dietary strategies such as time-restricted feeding or intermittent fasting. In the context of an age-related decrease in cellular polyamine levels, provision of exogenous spermidine can boost the hypusination reaction required for the appropriate post-translational modification of eIF5A. Low-protein plant-based diets could be expected to increase ATF4 and CHOP expression, while diminishing IGF-I-mediated activation of AKT and mTORC1. Hence, practical strategies for protecting health by up-regulating macroautophagy may be feasible.
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Affiliation(s)
- Mark F McCarty
- Catalytic Longevity Foundation, San Diego, CA 92109, USA
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10
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Trefts E, Shaw RJ. AMPK: restoring metabolic homeostasis over space and time. Mol Cell 2021; 81:3677-3690. [PMID: 34547233 DOI: 10.1016/j.molcel.2021.08.015] [Citation(s) in RCA: 154] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 12/25/2022]
Abstract
The evolution of AMPK and its homologs enabled exquisite responsivity and control of cellular energetic homeostasis. Recent work has been critical in establishing the mechanisms that determine AMPK activity, novel targets of AMPK action, and the distribution of AMPK-mediated control networks across the cellular landscape. The role of AMPK as a hub of metabolic control has led to intense interest in pharmacologic activation as a therapeutic avenue for a number of disease states, including obesity, diabetes, and cancer. As such, critical work on the compartmentalization of AMPK, its downstream targets, and the systems it influences has progressed in recent years. The variegated distribution of AMPK-mediated control of metabolic homeostasis has revealed key insights into AMPK in normal biology and future directions for AMPK-based therapeutic strategies.
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Affiliation(s)
- Elijah Trefts
- Molecular and Cell Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Reuben J Shaw
- Molecular and Cell Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA.
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11
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Aguilar-Recarte D, Palomer X, Wahli W, Vázquez-Carrera M. The PPARβ/δ-AMPK Connection in the Treatment of Insulin Resistance. Int J Mol Sci 2021; 22:8555. [PMID: 34445261 PMCID: PMC8395240 DOI: 10.3390/ijms22168555] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 12/12/2022] Open
Abstract
The current treatment options for type 2 diabetes mellitus do not adequately control the disease in many patients. Consequently, there is a need for new drugs to prevent and treat type 2 diabetes mellitus. Among the new potential pharmacological strategies, activators of peroxisome proliferator-activated receptor (PPAR)β/δ show promise. Remarkably, most of the antidiabetic effects of PPARβ/δ agonists involve AMP-activated protein kinase (AMPK) activation. This review summarizes the recent mechanistic insights into the antidiabetic effects of the PPARβ/δ-AMPK pathway, including the upregulation of glucose uptake, muscle remodeling, enhanced fatty acid oxidation, and autophagy, as well as the inhibition of endoplasmic reticulum stress and inflammation. A better understanding of the mechanisms underlying the effects resulting from the PPARβ/δ-AMPK pathway may provide the basis for the development of new therapies in the prevention and treatment of insulin resistance and type 2 diabetes mellitus.
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Affiliation(s)
- David Aguilar-Recarte
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Institute of Biomedicine of the University of Barcelona (IBUB), Faculty of Pharmacy and Food Sciences, University of Barcelona, Avinguda Joan XXIII 27-31, 08028 Barcelona, Spain; (D.A.-R.); (X.P.)
- Pediatric Research Institute-Hospital Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Diseases (CIBERDEM)-Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Xavier Palomer
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Institute of Biomedicine of the University of Barcelona (IBUB), Faculty of Pharmacy and Food Sciences, University of Barcelona, Avinguda Joan XXIII 27-31, 08028 Barcelona, Spain; (D.A.-R.); (X.P.)
- Pediatric Research Institute-Hospital Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Diseases (CIBERDEM)-Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Walter Wahli
- Center for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland;
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore 308232, Singapore
- ToxAlim (Research Center in Food Toxicology), INRAE, UMR1331, CEDEX, 31300 Toulouse, France
| | - Manuel Vázquez-Carrera
- Department of Pharmacology, Toxicology and Therapeutic Chemistry, Institute of Biomedicine of the University of Barcelona (IBUB), Faculty of Pharmacy and Food Sciences, University of Barcelona, Avinguda Joan XXIII 27-31, 08028 Barcelona, Spain; (D.A.-R.); (X.P.)
- Pediatric Research Institute-Hospital Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Diseases (CIBERDEM)-Instituto de Salud Carlos III, 28029 Madrid, Spain
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12
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Karabiyik C, Vicinanza M, Son SM, Rubinsztein DC. Glucose starvation induces autophagy via ULK1-mediated activation of PIKfyve in an AMPK-dependent manner. Dev Cell 2021; 56:1961-1975.e5. [PMID: 34107300 DOI: 10.1016/j.devcel.2021.05.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/24/2021] [Accepted: 05/12/2021] [Indexed: 12/11/2022]
Abstract
Autophagy is an essential catabolic process induced to provide cellular energy sources in response to nutrient limitation through the activation of kinases, like AMP-activated protein kinase (AMPK) and ULK1. Although glucose starvation induces autophagy, the exact mechanism underlying this signaling has yet to be elucidated. Here, we reveal a role for ULK1 in non-canonical autophagy signaling using diverse cell lines. ULK1 activated by AMPK during glucose starvation phosphorylates the lipid kinase PIKfyve on S1548, thereby increasing its activity and the synthesis of the phospholipid PI(5)P without changing the levels of PI(3,5)P2. ULK1-mediated activation of PIKfyve enhances the formation of PI(5)P-containing autophagosomes upon glucose starvation, resulting in an increase in autophagy flux. Phospho-mimic PIKfyve S1548D drives autophagy upregulation and lowers autophagy substrate levels. Our study has identified how ULK1 upregulates autophagy upon glucose starvation and induces the formation of PI(5)P-containing autophagosomes by activating PIKfyve.
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Affiliation(s)
- Cansu Karabiyik
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK; UK Dementia Research Institute, Cambridge, UK
| | - Mariella Vicinanza
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK; UK Dementia Research Institute, Cambridge, UK
| | - Sung Min Son
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK; UK Dementia Research Institute, Cambridge, UK
| | - David C Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK; UK Dementia Research Institute, Cambridge, UK.
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13
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Claude-Taupin A, Morel E. Phosphoinositides: Functions in autophagy-related stress responses. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158903. [PMID: 33578048 DOI: 10.1016/j.bbalip.2021.158903] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/29/2021] [Accepted: 02/06/2021] [Indexed: 01/02/2023]
Abstract
Phosphoinositides are key lipids in eukaryotes, regulating organelles' identity and function. Their synthesis and turnover require specific phosphorylation/dephosphorylation events that are ensured by dedicated lipid kinases and phosphatases, which modulate the structure of the inositol ring by adding or removing phosphates on positions 3, 4 or 5. Beside their implication in intracellular signalization and cytoskeleton dynamics, phosphoinositides are essential for vesicular transport along intracellular trafficking routes, by providing molecular scaffolds to membrane related events such as budding, fission or fusion. Robust and detailed literature demonstrated that some members of the phosphoinositides family are crucial for the autophagy pathway, acting as fine tuners and regulators. In this review, we discuss the known functions of phosphoinositides in autophagy canonical processes, such as during autophagosome formation, as well as the importance of phosphoinositides in organelle-based processes directly connected to the autophagic machinery, such as endosomal dynamics, ciliogenesis and innate immunity.
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Affiliation(s)
- Aurore Claude-Taupin
- Institut Necker Enfants-Malades (INEM), INSERM U1151-CNRS UMR 8253, Université de Paris, Paris, France
| | - Etienne Morel
- Institut Necker Enfants-Malades (INEM), INSERM U1151-CNRS UMR 8253, Université de Paris, Paris, France.
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14
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Bhutta MS, Gallo ES, Borenstein R. Multifaceted Role of AMPK in Viral Infections. Cells 2021; 10:1118. [PMID: 34066434 PMCID: PMC8148118 DOI: 10.3390/cells10051118] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/02/2021] [Accepted: 05/03/2021] [Indexed: 02/06/2023] Open
Abstract
Viral pathogens often exploit host cell regulatory and signaling pathways to ensure an optimal environment for growth and survival. Several studies have suggested that 5'-adenosine monophosphate-activated protein kinase (AMPK), an intracellular serine/threonine kinase, plays a significant role in the modulation of infection. Traditionally, AMPK is a key energy regulator of cell growth and proliferation, host autophagy, stress responses, metabolic reprogramming, mitochondrial homeostasis, fatty acid β-oxidation and host immune function. In this review, we highlight the modulation of host AMPK by various viruses under physiological conditions. These intracellular pathogens trigger metabolic changes altering AMPK signaling activity that then facilitates or inhibits viral replication. Considering the COVID-19 pandemic, understanding the regulation of AMPK signaling following infection can shed light on the development of more effective therapeutic strategies against viral infectious diseases.
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Affiliation(s)
- Maimoona Shahid Bhutta
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, USA;
| | - Elisa S. Gallo
- Board-Certified Dermatologist and Independent Researcher, Norfolk, VA 23507, USA;
| | - Ronen Borenstein
- Department of Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, USA;
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15
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Abstract
The field of phosphoinositide signaling has expanded significantly in recent years. Phosphoinositides (also known as phosphatidylinositol phosphates or PIPs) are universal signaling molecules that directly interact with membrane proteins or with cytosolic proteins containing domains that directly bind phosphoinositides and are recruited to cell membranes. Through the activities of phosphoinositide kinases and phosphoinositide phosphatases, seven distinct phosphoinositide lipid molecules are formed from the parent molecule, phosphatidylinositol. PIP signals regulate a wide range of cellular functions, including cytoskeletal assembly, membrane budding and fusion, ciliogenesis, vesicular transport, and signal transduction. Given the many excellent reviews on phosphoinositide kinases, phosphoinositide phosphatases, and PIPs in general, in this review, we discuss recent studies and advances in PIP lipid signaling in the retina. We specifically focus on PIP lipids from vertebrate (e.g., bovine, rat, mouse, toad, and zebrafish) and invertebrate (e.g., Drosophila, horseshoe crab, and squid) retinas. We also discuss the importance of PIPs revealed from animal models and human diseases, and methods to study PIP levels both in vitro and in vivo. We propose that future studies should investigate the function and mechanism of activation of PIP-modifying enzymes/phosphatases and further unravel PIP regulation and function in the different cell types of the retina.
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Affiliation(s)
- Raju V S Rajala
- Departments of Ophthalmology, Physiology, and Cell Biology, and Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104.
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16
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Wong CY, Al-Salami H, Dass CR. C2C12 cell model: its role in understanding of insulin resistance at the molecular level and pharmaceutical development at the preclinical stage. J Pharm Pharmacol 2020; 72:1667-1693. [PMID: 32812252 DOI: 10.1111/jphp.13359] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 07/17/2020] [Accepted: 07/25/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The myoblast cell line, C2C12, has been utilised extensively in vitro as an examination model in understanding metabolic disease progression. Although it is indispensable in both preclinical and pharmaceutical research, a comprehensive review of its use in the investigation of insulin resistance progression and pharmaceutical development is not available. KEY FINDINGS C2C12 is a well-documented model, which can facilitate our understanding in glucose metabolism, insulin signalling mechanism, insulin resistance, oxidative stress, reactive oxygen species and glucose transporters at cellular and molecular levels. With the aid of the C2C12 model, recent studies revealed that insulin resistance has close relationship with various metabolic diseases in terms of disease progression, pathogenesis and therapeutic management. A holistic, safe and effective disease management is highly of interest. Therefore, significant efforts have been paid to explore novel drug compounds and natural herbs that can elicit therapeutic effects in the targeted sites at both cellular (e.g. mitochondria, glucose transporter) and molecular level (e.g. genes, signalling pathway). SUMMARY The use of C2C12 myoblast cell line is meaningful in pharmaceutical and biomedical research due to their expression of GLUT-4 and other features that are representative to human skeletal muscle cells. With the use of the C2C12 cell model, the impact of drug delivery systems (nanoparticles and quantum dots) on skeletal muscle, as well as the relationship between exercise, pancreatic β-cells and endothelial cells, was discovered.
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Affiliation(s)
- Chun Y Wong
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, WA, Australia.,Curtin Health Innovation Research Institute, Bentley, WA, Australia
| | - Hani Al-Salami
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, WA, Australia.,Curtin Health Innovation Research Institute, Bentley, WA, Australia.,Biotechnology and Drug Development Research Laboratory, Curtin University, Bentley, WA, Australia
| | - Crispin R Dass
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, WA, Australia.,Curtin Health Innovation Research Institute, Bentley, WA, Australia
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17
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Yuan J, Dong X, Yap J, Hu J. The MAPK and AMPK signalings: interplay and implication in targeted cancer therapy. J Hematol Oncol 2020; 13:113. [PMID: 32807225 PMCID: PMC7433213 DOI: 10.1186/s13045-020-00949-4] [Citation(s) in RCA: 243] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 08/04/2020] [Indexed: 02/06/2023] Open
Abstract
Cancer is characterized as a complex disease caused by coordinated alterations of multiple signaling pathways. The Ras/RAF/MEK/ERK (MAPK) signaling is one of the best-defined pathways in cancer biology, and its hyperactivation is responsible for over 40% human cancer cases. To drive carcinogenesis, this signaling promotes cellular overgrowth by turning on proliferative genes, and simultaneously enables cells to overcome metabolic stress by inhibiting AMPK signaling, a key singular node of cellular metabolism. Recent studies have shown that AMPK signaling can also reversibly regulate hyperactive MAPK signaling in cancer cells by phosphorylating its key components, RAF/KSR family kinases, which affects not only carcinogenesis but also the outcomes of targeted cancer therapies against the MAPK signaling. In this review, we will summarize the current proceedings of how MAPK-AMPK signalings interplay with each other in cancer biology, as well as its implications in clinic cancer treatment with MAPK inhibition and AMPK modulators, and discuss the exploitation of combinatory therapies targeting both MAPK and AMPK as a novel therapeutic intervention.
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Affiliation(s)
- Jimin Yuan
- Department of Urology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, Guangdong, China.
- Geriatric Department, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, 518020, Guangdong, China.
| | - Xiaoduo Dong
- Shenzhen People's Hospital, 1017 Dongmen North Road, Shenzhen, 518020, China
| | - Jiajun Yap
- Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - Jiancheng Hu
- Cancer and Stem Cell Program, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore.
- Division of Cellular and Molecular Research, National Cancer Centre Singapore, 11 Hospital Drive, Singapore, 169610, Singapore.
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18
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Steinberg GR, Carling D. AMP-activated protein kinase: the current landscape for drug development. Nat Rev Drug Discov 2020; 18:527-551. [PMID: 30867601 DOI: 10.1038/s41573-019-0019-2] [Citation(s) in RCA: 390] [Impact Index Per Article: 97.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Since the discovery of AMP-activated protein kinase (AMPK) as a central regulator of energy homeostasis, many exciting insights into its structure, regulation and physiological roles have been revealed. While exercise, caloric restriction, metformin and many natural products increase AMPK activity and exert a multitude of health benefits, developing direct activators of AMPK to elicit beneficial effects has been challenging. However, in recent years, direct AMPK activators have been identified and tested in preclinical models, and a small number have entered clinical trials. Despite these advances, which disease(s) represent the best indications for therapeutic AMPK activation and the long-term safety of such approaches remain to be established.
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Affiliation(s)
- Gregory R Steinberg
- Centre for Metabolism, Obesity and Diabetes Research, Department of Medicine and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
| | - David Carling
- Cellular Stress Group, Medical Research Council London Institute of Medical Sciences, Hammersmith Hospital, Imperial College, London, UK
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19
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Rahmani S, Defferrari MS, Wakarchuk WW, Antonescu CN. Energetic adaptations: Metabolic control of endocytic membrane traffic. Traffic 2019; 20:912-931. [DOI: 10.1111/tra.12705] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 09/11/2019] [Accepted: 10/13/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Sadia Rahmani
- Department of Chemistry and BiologyRyerson University Toronto Ontario Canada
| | | | - Warren W. Wakarchuk
- Department of Chemistry and BiologyRyerson University Toronto Ontario Canada
- Department of Biological SciencesUniversity of Alberta Edmonton Alberta Canada
| | - Costin N. Antonescu
- Department of Chemistry and BiologyRyerson University Toronto Ontario Canada
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital Toronto Ontario Canada
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20
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Yordanov TE, Hipolito VEB, Liebscher G, Vogel GF, Stasyk T, Herrmann C, Geley S, Teis D, Botelho RJ, Hess MW, Huber LA. Biogenesis of lysosome-related organelles complex-1 (BORC) regulates late endosomal/lysosomal size through PIKfyve-dependent phosphatidylinositol-3,5-bisphosphate. Traffic 2019; 20:674-696. [PMID: 31314175 PMCID: PMC6771566 DOI: 10.1111/tra.12679] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 07/15/2019] [Indexed: 01/02/2023]
Abstract
Mechanisms that control lysosomal function are essential for cellular homeostasis. Lysosomes adapt in size and number to cellular needs but little is known about the underlying molecular mechanism. We demonstrate that the late endosomal/lysosomal multimeric BLOC-1-related complex (BORC) regulates the size of these organelles via PIKfyve-dependent phosphatidylinositol-3,5-bisphosphate [PI(3,5)P2 ] production. Deletion of the core BORC component Diaskedin led to increased levels of PI(3,5)P2 , suggesting activation of PIKfyve, and resulted in enhanced lysosomal reformation and subsequent reduction in lysosomal size. This process required AMP-activated protein kinase (AMPK), a known PIKfyve activator, and was additionally dependent on the late endosomal/lysosomal adaptor, mitogen-activated protein kinases and mechanistic target of rapamycin activator (LAMTOR/Ragulator) complex. Consistently, in response to glucose limitation, AMPK activated PIKfyve, which induced lysosomal reformation with increased baseline autophagy and was coupled to a decrease in lysosomal size. These adaptations of the late endosomal/lysosomal system reversed under glucose replete growth conditions. In summary, our results demonstrate that BORC regulates lysosomal reformation and size in response to glucose availability.
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Affiliation(s)
- Teodor E. Yordanov
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Victoria E. B. Hipolito
- Department of Chemistry and Biology and the Graduate Program in Molecular ScienceRyerson UniversityTorontoOntarioCanada
| | - Gudrun Liebscher
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Georg F. Vogel
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
- Department of Pediatrics IMedical University of InnsbruckInnsbruckAustria
| | - Taras Stasyk
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Caroline Herrmann
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Stephan Geley
- Division of Molecular Pathophysiology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - David Teis
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
| | - Roberto J. Botelho
- Department of Chemistry and Biology and the Graduate Program in Molecular ScienceRyerson UniversityTorontoOntarioCanada
| | - Michael W. Hess
- Division of Histology and EmbryologyMedical University of InnsbruckInnsbruckAustria
| | - Lukas A. Huber
- Division of Cell Biology, BiocenterMedical University of InnsbruckInnsbruckAustria
- Austrian Drug Screening Institute, ADSIInnsbruckAustria
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21
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Kjøbsted R, Roll JLW, Jørgensen NO, Birk JB, Foretz M, Viollet B, Chadt A, Al-Hasani H, Wojtaszewski JFP. AMPK and TBC1D1 Regulate Muscle Glucose Uptake After, but Not During, Exercise and Contraction. Diabetes 2019; 68:1427-1440. [PMID: 31010958 DOI: 10.2337/db19-0050] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 04/12/2019] [Indexed: 11/13/2022]
Abstract
Exercise increases glucose uptake in skeletal muscle independently of insulin signaling. This makes exercise an effective stimulus to increase glucose uptake in insulin-resistant skeletal muscle. AMPK has been suggested to regulate muscle glucose uptake during exercise/contraction, but findings from studies of various AMPK transgenic animals have not reached consensus on this matter. Comparing methods used in these studies reveals a hitherto unappreciated difference between those studies reporting a role of AMPK and those that do not. This led us to test the hypothesis that AMPK and downstream target TBC1D1 are involved in regulating muscle glucose uptake in the immediate period after exercise/contraction but not during exercise/contraction. Here we demonstrate that glucose uptake during exercise/contraction was not compromised in AMPK-deficient skeletal muscle, whereas reversal of glucose uptake toward resting levels after exercise/contraction was markedly faster in AMPK-deficient muscle compared with wild-type muscle. Moreover, muscle glucose uptake after contraction was positively associated with phosphorylation of TBC1D1, and skeletal muscle from TBC1D1-deficient mice displayed impaired glucose uptake after contraction. These findings reconcile previous observed discrepancies and redefine the role of AMPK activation during exercise/contraction as being important for maintaining glucose permeability in skeletal muscle in the period after, but not during, exercise/contraction.
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Affiliation(s)
- Rasmus Kjøbsted
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Julie L W Roll
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Nicolas O Jørgensen
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jesper B Birk
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Marc Foretz
- INSERM, U1016, Institut Cochin, Paris, France
- Centre National de la Recherche Scientifique (CNRS), UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Benoit Viollet
- INSERM, U1016, Institut Cochin, Paris, France
- Centre National de la Recherche Scientifique (CNRS), UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Alexandra Chadt
- German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Hadi Al-Hasani
- German Diabetes Center, Leibniz Center for Diabetes Research, Heinrich Heine University Düsseldorf, Medical Faculty, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise, and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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22
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Fernandez-Mosquera L, Yambire KF, Couto R, Pereyra L, Pabis K, Ponsford AH, Diogo CV, Stagi M, Milosevic I, Raimundo N. Mitochondrial respiratory chain deficiency inhibits lysosomal hydrolysis. Autophagy 2019; 15:1572-1591. [PMID: 30917721 PMCID: PMC6693470 DOI: 10.1080/15548627.2019.1586256] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Mitochondria are key organelles for cellular metabolism, and regulate several processes including cell death and macroautophagy/autophagy. Here, we show that mitochondrial respiratory chain (RC) deficiency deactivates AMP-activated protein kinase (AMPK, a key regulator of energy homeostasis) signaling in tissue and in cultured cells. The deactivation of AMPK in RC-deficiency is due to increased expression of the AMPK-inhibiting protein FLCN (folliculin). AMPK is found to be necessary for basal lysosomal function, and AMPK deactivation in RC-deficiency inhibits lysosomal function by decreasing the activity of the lysosomal Ca2+ channel MCOLN1 (mucolipin 1). MCOLN1 is regulated by phosphoinositide kinase PIKFYVE and its product PtdIns(3,5)P2, which is also decreased in RC-deficiency. Notably, reactivation of AMPK, in a PIKFYVE-dependent manner, or of MCOLN1 in RC-deficient cells, restores lysosomal hydrolytic capacity. Building on these data and the literature, we propose that downregulation of the AMPK-PIKFYVE-PtdIns(3,5)P2-MCOLN1 pathway causes lysosomal Ca2+ accumulation and impaired lysosomal catabolism. Besides unveiling a novel role of AMPK in lysosomal function, this study points to the mechanism that links mitochondrial malfunction to impaired lysosomal catabolism, underscoring the importance of AMPK and the complexity of organelle cross-talk in the regulation of cellular homeostasis. Abbreviation: ΔΨm: mitochondrial transmembrane potential; AMP: adenosine monophosphate; AMPK: AMP-activated protein kinase; ATG5: autophagy related 5; ATP: adenosine triphosphate; ATP6V0A1: ATPase, H+ transporting, lysosomal, V0 subbunit A1; ATP6V1A: ATPase, H+ transporting, lysosomal, V0 subbunit A; BSA: bovine serum albumin; CCCP: carbonyl cyanide-m-chlorophenylhydrazone; CREB1: cAMP response element binding protein 1; CTSD: cathepsin D; CTSF: cathepsin F; DMEM: Dulbecco’s modified Eagle’s medium; DMSO: dimethyl sulfoxide; EBSS: Earl’s balanced salt solution; ER: endoplasmic reticulum; FBS: fetal bovine serum; FCCP: carbonyl cyanide-p-trifluoromethoxyphenolhydrazone; GFP: green fluorescent protein; GPN: glycyl-L-phenylalanine 2-naphthylamide; LAMP1: lysosomal associated membrane protein 1; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MCOLN1/TRPML1: mucolipin 1; MEF: mouse embryonic fibroblast; MITF: melanocyte inducing transcription factor; ML1N*2-GFP: probe used to detect PtdIns(3,5)P2 based on the transmembrane domain of MCOLN1; MTORC1: mechanistic target of rapamycin kinase complex 1; NDUFS4: NADH:ubiquinone oxidoreductase subunit S4; OCR: oxygen consumption rate; PBS: phosphate-buffered saline; pcDNA: plasmid cytomegalovirus promoter DNA; PCR: polymerase chain reaction; PtdIns3P: phosphatidylinositol-3-phosphate; PtdIns(3,5)P2: phosphatidylinositol-3,5-bisphosphate; PIKFYVE: phosphoinositide kinase, FYVE-type zinc finger containing; P/S: penicillin-streptomycin; PVDF: polyvinylidene fluoride; qPCR: quantitative real time polymerase chain reaction; RFP: red fluorescent protein; RNA: ribonucleic acid; SDS-PAGE: sodium dodecyl sulfate polyacrylamide gel electrophoresis; shRNA: short hairpin RNA; siRNA: small interfering RNA; TFEB: transcription factor EB; TFE3: transcription factor binding to IGHM enhancer 3; TMRM: tetramethylrhodamine, methyl ester, perchlorate; ULK1: unc-51 like autophagy activating kinase 1; ULK2: unc-51 like autophagy activating kinase 2; UQCRC1: ubiquinol-cytochrome c reductase core protein 1; v-ATPase: vacuolar-type H+-translocating ATPase; WT: wild-type
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Affiliation(s)
- Lorena Fernandez-Mosquera
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany.,b Doctoral Program in Molecular Medicine, Georg August University Goettingen , Goettingen , Germany
| | - King Faisal Yambire
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany.,c International Max-Planck Research School in Neuroscience , Goettingen , Germany.,d European Neuroscience Institute Goettingen, University Medical Center Goettingen and Max-Planck Society , Goettingen , Germany
| | - Renata Couto
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany.,e Doctoral Program in Molecular Biology of Cells, Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Goettingen , Goettingen , Germany
| | - Leonardo Pereyra
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany.,e Doctoral Program in Molecular Biology of Cells, Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Goettingen , Goettingen , Germany
| | - Kamil Pabis
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany
| | - Amy H Ponsford
- f Institute of Translational Medicine, University of Liverpool , Liverpool , UK
| | - Cátia V Diogo
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany
| | - Massimiliano Stagi
- f Institute of Translational Medicine, University of Liverpool , Liverpool , UK
| | - Ira Milosevic
- d European Neuroscience Institute Goettingen, University Medical Center Goettingen and Max-Planck Society , Goettingen , Germany
| | - Nuno Raimundo
- a Institute of Cellular Biochemistry, University Medical Center Goettingen , Goettingen , Germany
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23
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Muise ES, Guan HP, Liu J, Nawrocki AR, Yang X, Wang C, Rodríguez CG, Zhou D, Gorski JN, Kurtz MM, Feng D, Leavitt KJ, Wei L, Wilkening RR, Apgar JM, Xu S, Lu K, Feng W, Li Y, He H, Previs SF, Shen X, van Heek M, Souza SC, Rosenbach MJ, Biftu T, Erion MD, Kelley DE, Kemp DM, Myers RW, Sebhat IK. Pharmacological AMPK activation induces transcriptional responses congruent to exercise in skeletal and cardiac muscle, adipose tissues and liver. PLoS One 2019; 14:e0211568. [PMID: 30811418 PMCID: PMC6392219 DOI: 10.1371/journal.pone.0211568] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 01/16/2019] [Indexed: 12/25/2022] Open
Abstract
Physical activity promotes metabolic and cardiovascular health benefits that derive in part from the transcriptional responses to exercise that occur within skeletal muscle and other organs. There is interest in discovering a pharmacologic exercise mimetic that could imbue wellness and alleviate disease burden. However, the molecular physiology by which exercise signals the transcriptional response is highly complex, making it challenging to identify a single target for pharmacological mimicry. The current studies evaluated the transcriptome responses in skeletal muscle, heart, liver, and white and brown adipose to novel small molecule activators of AMPK (pan-activators for all AMPK isoforms) compared to that of exercise. A striking level of congruence between exercise and pharmacological AMPK activation was observed across the induced transcriptome of these five tissues. However, differences in acute metabolic response between exercise and pharmacologic AMPK activation were observed, notably for acute glycogen balances and related to the energy expenditure induced by exercise but not pharmacologic AMPK activation. Nevertheless, intervention with repeated daily administration of short-acting activation of AMPK was found to mitigate hyperglycemia and hyperinsulinemia in four rodent models of metabolic disease and without the cardiac glycogen accretion noted with sustained pharmacologic AMPK activation. These findings affirm that activation of AMPK is a key node governing exercise mediated transcription and is an attractive target as an exercise mimetic.
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Affiliation(s)
- Eric S. Muise
- Genetics and Pharmacogenomics Department, MRL, Kenilworth, NJ, United States of America
- * E-mail: (ESM); (IKS)
| | - Hong-Ping Guan
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Jinqi Liu
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Andrea R. Nawrocki
- In Vivo Pharmacology Department, MRL, Kenilworth, NJ, United States of America
| | - Xiaodong Yang
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Chuanlin Wang
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Carlos G. Rodríguez
- In Vivo Pharmacology Department, MRL, Kenilworth, NJ, United States of America
| | - Dan Zhou
- In Vivo Pharmacology Department, MRL, Kenilworth, NJ, United States of America
| | - Judith N. Gorski
- In Vivo Pharmacology Department, MRL, Kenilworth, NJ, United States of America
| | - Marc M. Kurtz
- In Vitro PharmacologyDepartment, MRL, NJ, United States of America
| | - Danqing Feng
- Medicinal ChemistryDepartment, MRL, Kenilworth, NJ, United States of America
| | - Kenneth J. Leavitt
- Medicinal ChemistryDepartment, MRL, Kenilworth, NJ, United States of America
| | - Lan Wei
- Medicinal ChemistryDepartment, MRL, Kenilworth, NJ, United States of America
| | - Robert R. Wilkening
- Medicinal ChemistryDepartment, MRL, Kenilworth, NJ, United States of America
| | - James M. Apgar
- Medicinal ChemistryDepartment, MRL, Kenilworth, NJ, United States of America
| | - Shiyao Xu
- PPDM Preclinical ADME Department, MRL, Kenilworth, NJ, United States of America
| | - Ku Lu
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Wen Feng
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Ying Li
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Huaibing He
- PPDM Preclinical ADME Department, MRL, Kenilworth, NJ, United States of America
| | - Stephen F. Previs
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Xiaolan Shen
- SALAR Department, MRL, Kenilworth, NJ, United States of America
| | - Margaret van Heek
- In Vivo Pharmacology Department, MRL, Kenilworth, NJ, United States of America
| | - Sandra C. Souza
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Mark J. Rosenbach
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Tesfaye Biftu
- Medicinal ChemistryDepartment, MRL, Kenilworth, NJ, United States of America
| | - Mark D. Erion
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - David E. Kelley
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Daniel M. Kemp
- Biology-Discovery Department, MRL, Kenilworth, NJ, United States of America
| | - Robert W. Myers
- In Vitro PharmacologyDepartment, MRL, NJ, United States of America
| | - Iyassu K. Sebhat
- Medicinal ChemistryDepartment, MRL, Kenilworth, NJ, United States of America
- * E-mail: (ESM); (IKS)
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Intracellular signaling of the AMP-activated protein kinase. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 116:171-207. [DOI: 10.1016/bs.apcsb.2018.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Phosphoinositol metabolism affects AMP kinase-dependent K-ATP currents in rat substantia nigra dopamine neurons. Brain Res 2018; 1706:32-40. [PMID: 30722976 DOI: 10.1016/j.brainres.2018.10.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 10/23/2018] [Accepted: 10/25/2018] [Indexed: 11/21/2022]
Abstract
We reported recently that ligand-gated ATP-sensitive K+ (K-ATP) current is potentiated by AMP-activated protein kinase (AMPK) in rat substantia nigra compacta (SNC) dopamine neurons. Because phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) regulates K-ATP current, we explored the hypothesis that changes in PI(4,5)P2 modify the ability of AMPK to augment K-ATP current. To influence PI(4,5)P2 levels, we superfused brain slices with phospholipase C (PLC) activators and inhibitors while recording whole-cell currents in SNC dopamine neurons. Diazoxide, superfused for 5 min every 20 min, evoked K-ATP currents that, on average, increased from 38 pA at first application to 122 pA at the fourth application, a 220% increase. This enhancement of diazoxide-induced current was AMPK dependent because K-ATP current remained at baseline when slices were superfused with either the AMPK inhibitor dorsomorphin or the upstream kinase inhibitor STO-609. The PLC inhibitor U73122 significantly increased diazoxide current over control values, and this increase was blocked by dorsomorphin. Enhancement of diazoxide-induced current was also completely prevented by the PLC activator m-3M3FBS. Agonists at 5-HT2C and group I metabotropic glutamate receptors, both of which activate PLC, also prevented augmentation of diazoxide-induced current. Finally, inhibition of spike discharges by diazoxide was significantly antagonized by m-3M3FBS. These results suggest that PLC activity significantly influences the inhibitory effect of K-ATP channels by altering PI(4,5)P2 content. Results also suggest that modification of K-ATP current by PLC requires AMPK activity.
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Madsen AB, Knudsen JR, Henriquez-Olguin C, Angin Y, Zaal KJ, Sylow L, Schjerling P, Ralston E, Jensen TE. β-Actin shows limited mobility and is required only for supraphysiological insulin-stimulated glucose transport in young adult soleus muscle. Am J Physiol Endocrinol Metab 2018; 315. [PMID: 29533739 PMCID: PMC6087721 DOI: 10.1152/ajpendo.00392.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Studies in skeletal muscle cell cultures suggest that the cortical actin cytoskeleton is a major requirement for insulin-stimulated glucose transport, implicating the β-actin isoform, which in many cell types is the main actin isoform. However, it is not clear that β-actin plays such a role in mature skeletal muscle. Neither dependency of glucose transport on β-actin nor actin reorganization upon glucose transport have been tested in mature muscle. To investigate the role of β-actin in fully differentiated muscle, we performed a detailed characterization of wild type and muscle-specific β-actin knockout (KO) mice. The effects of the β-actin KO were subtle; however, we confirmed the previously reported decline in running performance of β-actin KO mice compared with wild type during repeated maximal running tests. We also found insulin-stimulated glucose transport into incubated muscles reduced in soleus but not in extensor digitorum longus muscle of young adult mice. Contraction-stimulated glucose transport trended toward the same pattern, but the glucose transport phenotype disappeared in soleus muscles from mature adult mice. No genotype-related differences were found in body composition or glucose tolerance or by indirect calorimetry measurements. To evaluate β-actin mobility in mature muscle, we electroporated green fluorescent protein (GFP)-β-actin into flexor digitorum brevis muscle fibers and measured fluorescence recovery after photobleaching. GFP-β-actin showed limited unstimulated mobility and no changes after insulin stimulation. In conclusion, β-actin is not required for glucose transport regulation in mature mouse muscle under the majority of the tested conditions. Thus, our work reveals fundamental differences in the role of the cortical β-actin cytoskeleton in mature muscle compared with cell culture.
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Affiliation(s)
- Agnete B Madsen
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Jonas R Knudsen
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Carlos Henriquez-Olguin
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
- Centro de Estudios Moleculares de la Célula, Instituto de Ciencias Biomédicas, Universidad de Chile ; Laboratory of Exercise Sciences, Clínica MEDS, Santiago , Chile
| | - Yeliz Angin
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Kristien J Zaal
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health , Bethesda, Maryland
| | - Lykke Sylow
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
| | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopedic Surgery, Bispebjerg Hospital , Copenhagen , Denmark
- Center of Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
| | - Evelyn Ralston
- Light Imaging Section, Office of Science and Technology, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health , Bethesda, Maryland
| | - Thomas E Jensen
- Department of Nutrition, Exercise and Sports, University of Copenhagen , Copenhagen , Denmark
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Distinct plasma lipids profiles of recurrent ovarian cancer by liquid chromatography-mass spectrometry. Oncotarget 2018; 8:46834-46845. [PMID: 27564116 PMCID: PMC5564526 DOI: 10.18632/oncotarget.11603] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 07/29/2016] [Indexed: 12/24/2022] Open
Abstract
Epithelial ovarian cancer (EOC) is the most deadly gynecologic malignancy worldwide due to its high recurrence rate after surgery and chemotherapy. There is a critical need for discovery of novel biomarkers for EOC recurrence providing higher prediction power than that of the present ones. Lipids have been reported to associate with development and progression of cancer. In the current study, we aim to identify and validate the lipids which were relevant to the ovarian cancer recurrence based on plasma lipidomics performed by ultra-performance liquid chromatography coupled with mass spectrometry. In order to fulfill this objective, plasma from 70 EOC patients with follow up information was obtained. The results revealed that patients with and without recurrence could be clearly distinguished based on their lipid profiles. Thirty-one lipid metabolites were identified as potential biomarkers for EOC recurrence. The AUC value of these metabolite combinations for predicting EOC recurrence was 0.897. In terms of clinical applicability, LysoPG(20:5) arose as a potential EOC recurrence predictive biomarker to increase the predictive power of clinical predictors from AUC value 0.739 to 0.875. Additionally, we still found that individuals with early relapses (< 6 months) had a distinctive metabolomic pattern compared with late EOC and non-EOC recurrence subjects. Interestingly, decreased levels of triglycerides (TGs) were found to be a specific metabolic feature foreshadowing an early relapse. In conclusion, plasma lipidomics study could be used for predicting EOC recurrences, as well as early and late recurrent cases. The lipid biomarker research improves the predictive power of clinical predictors and the identified biomarkers are of great prognostic and therapeutic potential.
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Wallroth A, Haucke V. Phosphoinositide conversion in endocytosis and the endolysosomal system. J Biol Chem 2017; 293:1526-1535. [PMID: 29282290 DOI: 10.1074/jbc.r117.000629] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Phosphoinositides (PIs) are phospholipids that perform crucial cell functions, ranging from cell migration and signaling to membrane trafficking, by serving as signposts of compartmental membrane identity. Although phosphatidylinositol 4,5-bisphosphate, 3-phosphate, and 3,5-bisphosphate are commonly considered as hallmarks of the plasma membrane, endosomes, and lysosomes, these compartments contain other functionally important PIs. Here, we review the roles of PIs in different compartments of the endolysosomal system in mammalian cells and discuss the mechanisms that spatiotemporally control PI conversion in endocytosis and endolysosomal membrane dynamics during endosome maturation and sorting. As defective PI conversion underlies human genetic diseases, including inherited myopathies, neurological disorders, and cancer, PI-converting enzymes represent potential targets for drug-based therapies.
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Affiliation(s)
- Alexander Wallroth
- From the Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin and
| | - Volker Haucke
- From the Leibniz-Institut für Molekulare Pharmakologie (FMP), Robert-Rössle-Strasse 10, 13125 Berlin and .,the Faculty of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, 14195 Berlin, Germany
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29
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Qiu S, Leung A, Bo Y, Kozak RA, Anand SP, Warkentin C, Salambanga FDR, Cui J, Kobinger G, Kobasa D, Côté M. Ebola virus requires phosphatidylinositol (3,5) bisphosphate production for efficient viral entry. Virology 2017; 513:17-28. [PMID: 29031163 DOI: 10.1016/j.virol.2017.09.028] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 09/28/2017] [Accepted: 09/30/2017] [Indexed: 12/11/2022]
Abstract
For entry, Ebola virus (EBOV) requires the interaction of its viral glycoprotein with the cellular protein Niemann-Pick C1 (NPC1) which resides in late endosomes and lysosomes. How EBOV is trafficked and delivered to NPC1 and whether this is positively regulated during entry remain unclear. Here, we show that the PIKfyve-ArPIKfyve-Sac3 cellular complex, which is involved in the metabolism of phosphatidylinositol (3,5) bisphosphate (PtdIns(3,5)P2), is critical for EBOV infection. Although the expression of all subunits of the complex was required for efficient entry, PIKfyve kinase activity was specifically critical for entry by all pathogenic filoviruses. Inhibition of PIKfyve prevented colocalization of EBOV with NPC1 and led to virus accumulation in intracellular vesicles with characteristics of early endosomes. Importantly, genetically-encoded phosphoinositide probes revealed an increase in PtdIns(3,5)P2-positive vesicles in cells during EBOV entry. Taken together, our studies suggest that EBOV requires PtdIns(3,5)P2 production in cells to promote efficient delivery to NPC1.
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Affiliation(s)
- Shirley Qiu
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Anders Leung
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Yuxia Bo
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Robert A Kozak
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Sai Priya Anand
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Corina Warkentin
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Fabiola D R Salambanga
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Jennifer Cui
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada
| | - Gary Kobinger
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada
| | - Darwyn Kobasa
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Canada; Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada
| | - Marceline Côté
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada; Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Canada.
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Kviklyte S, Vertommen D, Yerna X, Andersén H, Xu X, Gailly P, Bohlooly-Y M, Oscarsson J, Rider MH. Effects of genetic deletion of soluble 5'-nucleotidases NT5C1A and NT5C2 on AMPK activation and nucleotide levels in contracting mouse skeletal muscles. Am J Physiol Endocrinol Metab 2017; 313:E48-E62. [PMID: 28325731 DOI: 10.1152/ajpendo.00304.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 02/24/2017] [Accepted: 03/13/2017] [Indexed: 11/22/2022]
Abstract
AMP-activated protein kinase (AMPK) plays a key role in energy homeostasis and is activated in response to contraction-induced ATP depletion in skeletal muscle via a rise in intracellular AMP/ADP concentrations. AMP can be deaminated by AMP-deaminase (AMPD) to IMP, which is hydrolyzed to inosine by cytosolic 5'-nucleotidase II (NT5C2). AMP can also be hydrolyzed to adenosine by cytosolic 5'-nucleotidase 1A (NT5C1A). Previous gene silencing and overexpression studies indicated control of AMPK activation by NT5C enzymes. In the present study using gene knockout mouse models, we investigated the effects of NT5C1A and NT5C2 deletion on intracellular adenine nucleotide levels and AMPK activation in electrically stimulated skeletal muscles. Surprisingly, NT5C enzyme knockout did not lead to enhanced AMP or ADP concentrations in response to contraction, with no potentiation of increases in AMPK activity in extensor digitorum longus (EDL) and soleus mouse muscles. Moreover, dual blockade of AMP metabolism in EDL using an AMPD inhibitor combined with NT5C1A deletion did not enhance rises in AMP and ADP or increased AMPK activation by electrical stimulation. The results on muscles from the NT5C knockout mice contradict previous findings where AMP levels and AMPK activity were shown to be modulated by NT5C enzymes.
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Affiliation(s)
- Samanta Kviklyte
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Didier Vertommen
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Xavier Yerna
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium; and
| | | | - Xiufeng Xu
- AstraZeneca Research and Development, Mölndal, Sweden
| | - Philippe Gailly
- Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium; and
| | | | - Jan Oscarsson
- AstraZeneca Research and Development, Mölndal, Sweden
| | - Mark H Rider
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium;
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Smith BK, Steinberg GR. AMP-activated protein kinase, fatty acid metabolism, and insulin sensitivity. Curr Opin Clin Nutr Metab Care 2017; 20:248-253. [PMID: 28375880 DOI: 10.1097/mco.0000000000000380] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
PURPOSE OF REVIEW Insulin resistance is an important risk factor for metabolic diseases such as type 2 diabetes, cardiovascular disease and certain cancers. A common characteristic of strategies that improve insulin sensitivity involves the activation of the energy sensing enzyme of the cell, AMP-activated protein kinase (AMPK). The purpose of this review is to explore the mechanisms associated with AMPK activation to improve insulin sensitivity with a focus on fatty acid metabolism. We will also discuss the literature surrounding direct AMPK activators to improve insulin resistance and important considerations for the design of direct AMPK activators. RECENT FINDINGS AMPK activation can decrease de novo lipogenesis, increase fatty acid oxidation and promote mitochondrial integrity to improve insulin sensitivity. Drugs targeted to directly activate AMPK show therapeutic promise, yet in vivo data is lacking. SUMMARY Designing a drug to directly activate AMPK may improve insulin resistance by reducing liver de novo lipogenesis and increasing brown and white adipose tissue mitochondrial function. However, in vivo experimental procedures to support this notion are not extensive and more research is required.
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Affiliation(s)
- Brennan K Smith
- aDivision of Endocrinology and Metabolism, Department of Medicine bDepartment of Biochemistry, McMaster University, Hamilton, Ontario, Canada
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Sylow L, Kleinert M, Richter EA, Jensen TE. Exercise-stimulated glucose uptake - regulation and implications for glycaemic control. Nat Rev Endocrinol 2017; 13:133-148. [PMID: 27739515 DOI: 10.1038/nrendo.2016.162] [Citation(s) in RCA: 265] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Skeletal muscle extracts glucose from the blood to maintain demand for carbohydrates as an energy source during exercise. Such uptake involves complex molecular signalling processes that are distinct from those activated by insulin. Exercise-stimulated glucose uptake is preserved in insulin-resistant muscle, emphasizing exercise as a therapeutic cornerstone among patients with metabolic diseases such as diabetes mellitus. Exercise increases uptake of glucose by up to 50-fold through the simultaneous stimulation of three key steps: delivery, transport across the muscle membrane and intracellular flux through metabolic processes (glycolysis and glucose oxidation). The available data suggest that no single signal transduction pathway can fully account for the regulation of any of these key steps, owing to redundancy in the signalling pathways that mediate glucose uptake to ensure maintenance of muscle energy supply during physical activity. Here, we review the molecular mechanisms that regulate the movement of glucose from the capillary bed into the muscle cell and discuss what is known about their integrated regulation during exercise. Novel developments within the field of mass spectrometry-based proteomics indicate that the known regulators of glucose uptake are only the tip of the iceberg. Consequently, many exciting discoveries clearly lie ahead.
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Affiliation(s)
- Lykke Sylow
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Maximilian Kleinert
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Erik A Richter
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E Jensen
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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33
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Bultot L, Jensen TE, Lai YC, Madsen ALB, Collodet C, Kviklyte S, Deak M, Yavari A, Foretz M, Ghaffari S, Bellahcene M, Ashrafian H, Rider MH, Richter EA, Sakamoto K. Benzimidazole derivative small-molecule 991 enhances AMPK activity and glucose uptake induced by AICAR or contraction in skeletal muscle. Am J Physiol Endocrinol Metab 2016; 311:E706-E719. [PMID: 27577855 PMCID: PMC5241553 DOI: 10.1152/ajpendo.00237.2016] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/19/2016] [Indexed: 11/22/2022]
Abstract
AMP-activated protein kinase (AMPK) plays diverse roles and coordinates complex metabolic pathways for maintenance of energy homeostasis. This could be explained by the fact that AMPK exists as multiple heterotrimer complexes comprising a catalytic α-subunit (α1 and α2) and regulatory β (β1 and β2)- and γ (γ1, γ2, γ3)-subunits, which are uniquely distributed across different cell types. There has been keen interest in developing specific and isoform-selective AMPK-activating drugs for therapeutic use and also as research tools. Moreover, establishing ways of enhancing cellular AMPK activity would be beneficial for both purposes. Here, we investigated if a recently described potent AMPK activator called 991, in combination with the commonly used activator 5-aminoimidazole-4-carboxamide riboside or contraction, further enhances AMPK activity and glucose transport in mouse skeletal muscle ex vivo. Given that the γ3-subunit is exclusively expressed in skeletal muscle and has been implicated in contraction-induced glucose transport, we measured the activity of AMPKγ3 as well as ubiquitously expressed γ1-containing complexes. We initially validated the specificity of the antibodies for the assessment of isoform-specific AMPK activity using AMPK-deficient mouse models. We observed that a low dose of 991 (5 μM) stimulated a modest or negligible activity of both γ1- and γ3-containing AMPK complexes. Strikingly, dual treatment with 991 and 5-aminoimidazole-4-carboxamide riboside or 991 and contraction profoundly enhanced AMPKγ1/γ3 complex activation and glucose transport compared with any of the single treatments. The study demonstrates the utility of a dual activator approach to achieve a greater activation of AMPK and downstream physiological responses in various cell types, including skeletal muscle.
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Affiliation(s)
- Laurent Bultot
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland
| | - Thomas E Jensen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Yu-Chiang Lai
- Université catholique de Louvain and de Duve Institute, Brussels, Belgium
| | - Agnete L B Madsen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Caterina Collodet
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland; School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Samanta Kviklyte
- Université catholique de Louvain and de Duve Institute, Brussels, Belgium
| | - Maria Deak
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland
| | - Arash Yavari
- Experimental Therapeutics and Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Marc Foretz
- U1016, Institut National de la Santé et de la Recherche Médicale, Institut Cochin, Paris, France; UMR8104, Centre National de la Recherche Scientifique, Paris, France; and Université Paris Descartes, Paris, France
| | - Sahar Ghaffari
- Experimental Therapeutics and Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Mohamed Bellahcene
- Experimental Therapeutics and Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Houman Ashrafian
- Experimental Therapeutics and Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Mark H Rider
- Université catholique de Louvain and de Duve Institute, Brussels, Belgium
| | - Erik A Richter
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Kei Sakamoto
- Nestlé Institute of Health Sciences SA, EPFL Innovation Park, Lausanne, Switzerland; School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland;
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Subetta Enhances Sensitivity of Human Muscle Cells to Insulin. Bull Exp Biol Med 2015; 159:463-5. [DOI: 10.1007/s10517-015-2992-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Indexed: 11/25/2022]
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Messenger SW, Thomas DD, Cooley MM, Jones EK, Falkowski MA, August BK, Fernandez LA, Gorelick FS, Groblewski GE. Early to Late Endosome Trafficking Controls Secretion and Zymogen Activation in Rodent and Human Pancreatic Acinar Cells. Cell Mol Gastroenterol Hepatol 2015; 1:695-709. [PMID: 26618189 PMCID: PMC4657148 DOI: 10.1016/j.jcmgh.2015.08.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND & AIMS Pancreatic acinar cells have an expanded apical endosomal system, the physiological and pathophysiological significance of which is still emerging. Phosphatidylinositol-3,5-bisphosphate (PI(3,5)P2) is an essential phospholipid generated by PIKfyve, which phosphorylates phosphatidylinositol-3-phosphate (PI(3)P). PI(3,5)P2 is necessary for maturation of early endosomes (EE) to late endosomes (LE). Inhibition of EE to LE trafficking enhances anterograde endosomal trafficking and secretion at the plasma membrane by default through a recycling endosome (RE) intermediate. We assessed the effects of modulating PIKfyve activity on apical trafficking and pancreatitis responses in pancreatic acinar cells. METHODS Inhibition of EE to LE trafficking was achieved using pharmacological inhibitors of PIKfyve, expression of dominant negative PIKfyve K1877E, or constitutively active Rab5-GTP Q79L. Anterograde endosomal trafficking was manipulated by expression of constitutively active and dominant negative Rab11a mutants. The effects of these agents on secretion, endolysosomal exocytosis of lysosome associated membrane protein (LAMP1), and trypsinogen activation in response to high-dose CCK-8, bile acids and cigarette toxin was determined. RESULTS PIKfyve inhibition increased basal and stimulated secretion. Adenoviral overexpression of PIKfyve decreased secretion leading to cellular death. Expression of Rab5-GTP Q79L or Rab11a-GTP Q70L enhanced secretion. Conversely, dominant-negative Rab11a-GDP S25N reduced secretion. High-dose CCK inhibited endolysosomal exocytosis that was reversed by PIKfyve inhibition. PIKfyve inhibition blocked intracellular trypsin accumulation and cellular damage responses to high CCK-8, tobacco toxin, and bile salts in both rodent and human acini. CONCLUSIONS These data demonstrate that EE-LE trafficking acutely controls acinar secretion and the intracellular activation of zymogens leading to the pathogenicity of acute pancreatitis.
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Affiliation(s)
- Scott W. Messenger
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin
| | - Diana D.H. Thomas
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin
| | - Michelle M. Cooley
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin
| | - Elaina K. Jones
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin
| | | | - Benjamin K. August
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin
| | | | - Fred S. Gorelick
- Department of Internal Medicine, School of Medicine, Yale University, New Haven, Connecticut,Department of Cell Biology, School of Medicine, Yale University, New Haven, Connecticut,Veterans Administration Connecticut Healthcare, West Haven, Connecticut
| | - Guy E. Groblewski
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin,Correspondence Address correspondence to: Guy E. Groblewski, PhD, University of Wisconsin–Madison, Department of Nutritional Sciences, 1415 Linden Drive, Madison, Wisconsin 53706. fax: (608) 262-5860.University of Wisconsin–MadisonDepartment of Nutritional Sciences1415 Linden DriveMadisonWisconsin 53706
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Plaideau C, Lai YC, Kviklyte S, Zanou N, Löfgren L, Andersén H, Vertommen D, Gailly P, Hue L, Bohlooly-Y M, Hallén S, Rider MH. Effects of pharmacological AMP deaminase inhibition and Ampd1 deletion on nucleotide levels and AMPK activation in contracting skeletal muscle. ACTA ACUST UNITED AC 2015; 21:1497-1510. [PMID: 25459662 DOI: 10.1016/j.chembiol.2014.09.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 08/08/2014] [Accepted: 09/03/2014] [Indexed: 11/28/2022]
Abstract
AMP-activated protein kinase (AMPK) plays a central role in regulating metabolism and energy homeostasis. It achieves its function by sensing fluctuations in the AMP:ATP ratio. AMP deaminase (AMPD) converts AMP into IMP, and the AMPD1 isoenzyme is expressed in skeletal muscles. Here, effects of pharmacological inhibition and genetic deletion of AMPD were examined in contracting skeletal muscles. Pharmacological AMPD inhibition potentiated rises in AMP, AMP:ATP ratio, AMPK Thr172, and acetyl-CoA carboxylase (ACC) Ser218 phosphorylation induced by electrical stimulation, without affecting glucose transport. In incubated extensor digitorum longus and soleus muscles from Ampd1 knockout mice, increases in AMP levels and AMP:ATP ratio by electrical stimulation were potentiated considerably compared with muscles from wild-type mice, whereas enhanced AMPK activation was moderate and only observed in soleus, suggesting control by factors other than changes in adenine nucleotides. AMPD inhibitors could be useful tools for enhancing AMPK activation in cells and tissues during ATP-depletion.
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Glade MJ, Smith K. A glance at … exercise and glucose uptake. Nutrition 2015; 31:893-7. [PMID: 25933500 DOI: 10.1016/j.nut.2014.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 12/03/2014] [Indexed: 10/24/2022]
Affiliation(s)
| | - Kyl Smith
- Progressive Laboratories Inc., Irving, Texas
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Hong YH, Frugier T, Zhang X, Murphy RM, Lynch GS, Betik AC, Rattigan S, McConell GK. Glucose uptake during contraction in isolated skeletal muscles from neuronal nitric oxide synthase μ knockout mice. J Appl Physiol (1985) 2015; 118:1113-21. [PMID: 25749441 DOI: 10.1152/japplphysiol.00056.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 02/28/2015] [Indexed: 01/25/2023] Open
Abstract
Inhibition of nitric oxide synthase (NOS) significantly attenuates the increase in skeletal muscle glucose uptake during contraction/exercise, and a greater attenuation is observed in individuals with Type 2 diabetes compared with healthy individuals. Therefore, NO appears to play an important role in mediating muscle glucose uptake during contraction. In this study, we investigated the involvement of neuronal NOSμ (nNOSμ), the main NOS isoform activated during contraction, on skeletal muscle glucose uptake during ex vivo contraction. Extensor digitorum longus muscles were isolated from nNOSμ(-/-) and nNOSμ(+/+) mice. Muscles were contracted ex vivo in a temperature-controlled (30°C) organ bath with or without the presence of the NOS inhibitor N(G)-monomethyl-l-arginine (L-NMMA) and the NOS substrate L-arginine. Glucose uptake was determined by radioactive tracers. Skeletal muscle glucose uptake increased approximately fourfold during contraction in muscles from both nNOSμ(-/-) and nNOSμ(+/+) mice. L-NMMA significantly attenuated the increase in muscle glucose uptake during contraction in both genotypes. This attenuation was reversed by L-arginine, suggesting that L-NMMA attenuated the increase in muscle glucose uptake during contraction by inhibiting NOS and not via a nonspecific effect of the inhibitor. Low levels of NOS activity (~4%) were detected in muscles from nNOSμ(-/-) mice, and there was no evidence of compensation from other NOS isoform or AMP-activated protein kinase which is also involved in mediating muscle glucose uptake during contraction. These results indicate that NO regulates skeletal muscle glucose uptake during ex vivo contraction independently of nNOSμ.
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Affiliation(s)
- Yet Hoi Hong
- College of Health and Biomedicine and Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia; Department of Physiology, Faculty of Medicine, University of Malaya, Malaysia
| | - Tony Frugier
- Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Australia
| | - Xinmei Zhang
- Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia
| | - Robyn M Murphy
- Department of Zoology, La Trobe University, Melbourne, Australia
| | - Gordon S Lynch
- Department of Physiology, University of Melbourne, Melbourne, Australia; and
| | - Andrew C Betik
- College of Health and Biomedicine and Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia
| | - Stephen Rattigan
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Australia
| | - Glenn K McConell
- College of Health and Biomedicine and Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia;
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PI(5)P regulates autophagosome biogenesis. Mol Cell 2015; 57:219-34. [PMID: 25578879 PMCID: PMC4306530 DOI: 10.1016/j.molcel.2014.12.007] [Citation(s) in RCA: 183] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 10/22/2014] [Accepted: 11/25/2014] [Indexed: 01/12/2023]
Abstract
Phosphatidylinositol 3-phosphate (PI(3)P), the product of class III PI3K VPS34, recruits specific autophagic effectors, like WIPI2, during the initial steps of autophagosome biogenesis and thereby regulates canonical autophagy. However, mammalian cells can produce autophagosomes through enigmatic noncanonical VPS34-independent pathways. Here we show that PI(5)P can regulate autophagy via PI(3)P effectors and thereby identify a mechanistic explanation for forms of noncanonical autophagy. PI(5)P synthesis by the phosphatidylinositol 5-kinase PIKfyve was required for autophagosome biogenesis, and it increased levels of PI(5)P, stimulated autophagy, and reduced the levels of autophagic substrates. Inactivation of VPS34 impaired recruitment of WIPI2 and DFCP1 to autophagic precursors, reduced ATG5-ATG12 conjugation, and compromised autophagosome formation. However, these phenotypes were rescued by PI(5)P in VPS34-inactivated cells. These findings provide a mechanistic framework for alternative VPS34-independent autophagy-initiating pathways, like glucose starvation, and unravel a cytoplasmic function for PI(5)P, which previously has been linked predominantly to nuclear roles. PI(5)P positively regulates autophagy PI(5)P is associated with autophagy effectors that bind PI(3)P PI(5)P sustains noncanonical autophagy in PI(3)P-depleted cells PI(5)P is essential for VPS34-independent, glucose-starvation-induced autophagy
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Jensen TE, Angin Y, Sylow L, Richter EA. Is contraction-stimulated glucose transport feedforward regulated by Ca2+? Exp Physiol 2014; 99:1562-8. [DOI: 10.1113/expphysiol.2014.081679] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Thomas E. Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports; University of Copenhagen; Denmark
| | - Yeliz Angin
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports; University of Copenhagen; Denmark
| | - Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports; University of Copenhagen; Denmark
| | - Erik A. Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports; University of Copenhagen; Denmark
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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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Kim GH, Dayam RM, Prashar A, Terebiznik M, Botelho RJ. PIKfyve Inhibition Interferes with Phagosome and Endosome Maturation in Macrophages. Traffic 2014; 15:1143-63. [DOI: 10.1111/tra.12199] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 07/11/2014] [Accepted: 07/14/2014] [Indexed: 01/17/2023]
Affiliation(s)
- Grace H.E. Kim
- Deparment of Chemistry and Biology and the Molecular Science Program; Ryerson University; Toronto Ontario M5B2K3 Canada
| | - Roya M. Dayam
- Deparment of Chemistry and Biology and the Molecular Science Program; Ryerson University; Toronto Ontario M5B2K3 Canada
| | - Akriti Prashar
- Department of Cell and Systems Biology; University of Toronto at Scarborough; Toronto Ontario M1C 1A4 Canada
| | - Mauricio Terebiznik
- Department of Cell and Systems Biology; University of Toronto at Scarborough; Toronto Ontario M1C 1A4 Canada
| | - Roberto J. Botelho
- Deparment of Chemistry and Biology and the Molecular Science Program; Ryerson University; Toronto Ontario M5B2K3 Canada
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A small-molecule benzimidazole derivative that potently activates AMPK to increase glucose transport in skeletal muscle: comparison with effects of contraction and other AMPK activators. Biochem J 2014; 460:363-75. [PMID: 24665903 DOI: 10.1042/bj20131673] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
AMPK (AMP-activated protein kinase) is an attractive therapeutic drug target for treating metabolic disorders. We studied the effects of an AMPK activator developed by Merck (ex229 from patent application WO2010036613), comparing chemical activation with contraction in intact incubated skeletal muscles. We also compared effects of ex229 with those of the Abbott A769662 compound and AICAR (5-amino-4-imidazolecarboxamide riboside). In rat epitrochlearis muscle, ex229 dose-dependently increased AMPK activity of α1-, α2-, β1- and β2-containing complexes with significant increases in AMPK activity seen at a concentration of 50 μM. At a concentration of 100 μM, AMPK activation was similar to that observed after contraction and importantly led to an ~2-fold increase in glucose uptake. In AMPK α1-/α2-catalytic subunit double-knockout myotubes incubated with ex229, the increases in glucose uptake and ACC (acetyl-CoA carboxylase) phosphorylation seen in control cells were completely abolished, suggesting that the effects of the compound were AMPK-dependent. When muscle glycogen levels were reduced by ~50% after starvation, ex229-induced AMPK activation and glucose uptake were amplified in a wortmannin-independent manner. In L6 myotubes incubated with ex229, fatty acid oxidation was increased. Furthermore, in mouse EDL (extensor digitorum longus) and soleus muscles, ex229 increased both AMPK activity and glucose uptake at least 2-fold. In summary, ex229 efficiently activated skeletal muscle AMPK and elicited metabolic effects in muscle appropriate for treating Type 2 diabetes by stimulating glucose uptake and increasing fatty acid oxidation.
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Contraction-stimulated glucose transport in muscle is controlled by AMPK and mechanical stress but not sarcoplasmatic reticulum Ca(2+) release. Mol Metab 2014; 3:742-53. [PMID: 25353002 PMCID: PMC4209358 DOI: 10.1016/j.molmet.2014.07.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/11/2014] [Accepted: 07/16/2014] [Indexed: 12/25/2022] Open
Abstract
Understanding how muscle contraction orchestrates insulin-independent muscle glucose transport may enable development of hyperglycemia-treating drugs. The prevailing concept implicates Ca2+ as a key feed forward regulator of glucose transport with secondary fine-tuning by metabolic feedback signals through proteins such as AMPK. Here, we demonstrate in incubated mouse muscle that Ca2+ release is neither sufficient nor strictly necessary to increase glucose transport. Rather, the glucose transport response is associated with metabolic feedback signals through AMPK, and mechanical stress-activated signals. Furthermore, artificial stimulation of AMPK combined with passive stretch of muscle is additive and sufficient to elicit the full contraction glucose transport response. These results suggest that ATP-turnover and mechanical stress feedback are sufficient to fully increase glucose transport during muscle contraction, and call for a major reconsideration of the established Ca2+ centric paradigm.
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Involvement of the AMPK–PTEN pathway in insulin resistance induced by high glucose in cultured rat podocytes. Int J Biochem Cell Biol 2014; 51:120-30. [DOI: 10.1016/j.biocel.2014.04.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 03/28/2014] [Accepted: 04/09/2014] [Indexed: 11/17/2022]
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46
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Dërmaku-Sopjani M, Abazi S, Faggio C, Kolgeci J, Sopjani M. AMPK-sensitive cellular transport. J Biochem 2014; 155:147-58. [PMID: 24440827 DOI: 10.1093/jb/mvu002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The energy sensing AMP-activated protein kinase (AMPK) regulates cellular and whole-body energy balance through stimulating catabolic ATP-generating and suppressing anabolic ATP-consuming pathways thereby helping cells survive during energy depletion. The kinase has previously been reported to be either directly or indirectly involved in the regulation of several carriers, channels and pumps of high significance in cellular physiology. Thus AMPK provides a necessary link between cellular energy metabolism and cellular transport activity. Better understanding of the AMPK role in cellular transport offers a potential for improved therapies in various human diseases and disorders. In this review, we discuss recent advances in understanding the role and function of AMPK in transport regulation under physiological and pathological states.
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Affiliation(s)
- Miribane Dërmaku-Sopjani
- Faculty of Medicine, University of Prishtina, Str. Bulevardi i Dëshmorëve, p.n. 10 000 Prishtina, Kosova; Department of Chemistry, University of Prishtina, Str. 'Nëna Terezë' p.n. 10 000 Prishtina, Kosova; Department of Chemistry, University of Tirana, Tirana, Albania; and Department of Biological and Environmental Sciences, University of Messina, Viale Ferdinando Stagno d'Alcontres, 31, 98166 S.Agata-Messina, Italy
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Abstract
GLUT4 is regulated by its intracellular localization. In the absence of insulin, GLUT4 is efficiently retained intracellularly within storage compartments in muscle and fat cells. Upon insulin stimulation (and contraction in muscle), GLUT4 translocates from these compartments to the cell surface where it transports glucose from the extracellular milieu into the cell. Its implication in insulin-regulated glucose uptake makes GLUT4 not only a key player in normal glucose homeostasis but also an important element in insulin resistance and type 2 diabetes. Nevertheless, how GLUT4 is retained intracellularly and how insulin acts on this retention mechanism is largely unclear. In this review, the current knowledge regarding the various molecular processes that govern GLUT4 physiology is discussed as well as the questions that remain.
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Lang F, Föller M. Regulation of ion channels and transporters by AMP-activated kinase (AMPK). Channels (Austin) 2013; 8:20-8. [PMID: 24366036 DOI: 10.4161/chan.27423] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The energy-sensing AMP-activated kinase AMPK ensures survival of energy-depleted cells by stimulating ATP production and limiting ATP utilization. Both energy production and energy consumption are profoundly influenced by transport processes across the cell membane including channels, carriers and pumps. Accordingly, AMPK is a powerful regulator of transport across the cell membrane. AMPK regulates diverse K(+) channels, Na(+) channels, Ca(2+) release activated Ca(2+) channels, Cl(-) channels, gap junctional channels, glucose carriers, Na(+)/H(+)-exchanger, monocarboxylate-, phosphate-, creatine-, amino acid-, peptide- and osmolyte-transporters, Na(+)/Ca(2+)-exchanger, H(+)-ATPase and Na(+)/K(+)-ATPase. AMPK activates ubiquitin ligase Nedd4-2, which labels several plasma membrane proteins for degradation. AMPK further regulates transport proteins by inhibition of Rab GTPase activating protein (GAP) TBC1D1. It stimulates phosphatidylinositol 3-phosphate 5-kinase PIKfyve and inhibits phosphatase and tensin homolog (PTEN) via glycogen synthase kinase 3β (GSK3β). Moreover, it stabilizes F-actin as well as downregulates transcription factor NF-κB. All those cellular effects serve to regulate transport proteins.
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Affiliation(s)
- Florian Lang
- Department of Physiology; University of Tübingen; Tübingen, Germany
| | - Michael Föller
- Department of Physiology; University of Tübingen; Tübingen, Germany
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Abstract
Skeletal muscle is critical for whole-body glucose homoeostasis. Insulin and muscle contractions induced by exercise can increase glucose uptake through distinct intracellular signalling pathways involving PKB (protein kinase B)/Akt and AMPK (AMP-activated protein kinase) respectively. Whereas the proximal events governing these processes are becoming well understood, less is known about the regulation of the complex events necessary for the control of glucose uptake at the plasma membrane. In recent years, a number of common targets of AMPK and PKB/Akt have emerged as important components controlling glucose uptake, but the necessary phosphorylation events required for the control of glucose uptake have remained more elusive. In the current issue of the Biochemical Journal, Liu et al. identify that PIKfyve, a phosphoinositide phosphate kinase, is required for contraction-stimulated glucose uptake. They demonstrate that AMPK directly phosphorylates PIKfyve at Ser307, the same site as PKB/Akt, and that phosphorylation is increased in response to muscle contractions. These data provide compelling evidence for a new AMPK substrate that converges with PKB/Akt signalling and may be critical for the control of glucose uptake in skeletal muscle.
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