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Møller LLV, Ali MS, Davey J, Raun SH, Andersen NR, Long JZ, Qian H, Jeppesen JF, Henriquez-Olguin C, Frank E, Jensen TE, Højlund K, Wojtaszewski JFP, Nielsen J, Chiu TT, Jedrychowski MP, Gregorevic P, Klip A, Richter EA, Sylow L. The Rho guanine dissociation inhibitor α inhibits skeletal muscle Rac1 activity and insulin action. Proc Natl Acad Sci U S A 2023; 120:e2211041120. [PMID: 37364105 PMCID: PMC10318982 DOI: 10.1073/pnas.2211041120] [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: 07/11/2022] [Accepted: 05/22/2023] [Indexed: 06/28/2023] Open
Abstract
The molecular events governing skeletal muscle glucose uptake have pharmacological potential for managing insulin resistance in conditions such as obesity, diabetes, and cancer. With no current pharmacological treatments to target skeletal muscle insulin sensitivity, there is an unmet need to identify the molecular mechanisms that control insulin sensitivity in skeletal muscle. Here, the Rho guanine dissociation inhibitor α (RhoGDIα) is identified as a point of control in the regulation of insulin sensitivity. In skeletal muscle cells, RhoGDIα interacted with, and thereby inhibited, the Rho GTPase Rac1. In response to insulin, RhoGDIα was phosphorylated at S101 and Rac1 dissociated from RhoGDIα to facilitate skeletal muscle GLUT4 translocation. Accordingly, siRNA-mediated RhoGDIα depletion increased Rac1 activity and elevated GLUT4 translocation. Consistent with RhoGDIα's inhibitory effect, rAAV-mediated RhoGDIα overexpression in mouse muscle decreased insulin-stimulated glucose uptake and was detrimental to whole-body glucose tolerance. Aligning with RhoGDIα's negative role in insulin sensitivity, RhoGDIα protein content was elevated in skeletal muscle from insulin-resistant patients with type 2 diabetes. These data identify RhoGDIα as a clinically relevant controller of skeletal muscle insulin sensitivity and whole-body glucose homeostasis, mechanistically by modulating Rac1 activity.
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Affiliation(s)
- Lisbeth L. V. Møller
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Mona S. Ali
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Jonathan Davey
- The Centre for Muscle Research, Department of Physiology, The University of Melbourne, Parkville, VIC3010, Australia
| | - Steffen H. Raun
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Nicoline R. Andersen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Jonathan Z. Long
- Department of Pathology, Stanford University School of Medicine and Stanford, Stanford University, Stanford, CA94305
| | - Hongwei Qian
- The Centre for Muscle Research, Department of Physiology, The University of Melbourne, Parkville, VIC3010, Australia
| | - Jacob F. Jeppesen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Carlos Henriquez-Olguin
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
- Exercise Science Laboratory, Faculty of Medicine, Universidad Finis Terrae, 7501015Santiago, Chile
| | - Emma Frank
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Thomas E. Jensen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Kurt Højlund
- Steno Diabetes Center Odense, Odense University Hospital, 5000Odense C, Denmark
- Department of Clinical Research, University of Southern Denmark, 5000Odense C, Denmark
- Department of Molecular Medicine, University of Southern Denmark, 5000Odense C, Denmark
| | - Jørgen F. P. Wojtaszewski
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Joachim Nielsen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, 5230Odense M, Denmark
| | - Tim T. Chiu
- Cell Biology Program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A1, Canada
- Department of Physiology, University of Toronto, Toronto, ONM5S 1A1, Canada
- Department of Paediatrics, University of Toronto, Toronto, ONM5S 1A1, Canada
| | - Mark P. Jedrychowski
- Department of Cell Biology, Harvard Medical School, Boston, MA02115
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA02215
| | - Paul Gregorevic
- The Centre for Muscle Research, Department of Physiology, The University of Melbourne, Parkville, VIC3010, Australia
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A1, Canada
- Department of Physiology, University of Toronto, Toronto, ONM5S 1A1, Canada
- Department of Paediatrics, University of Toronto, Toronto, ONM5S 1A1, Canada
| | - Erik A. Richter
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
| | - Lykke Sylow
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2200Copenhagen N, Denmark
- Department of Biomedical Sciences, Faculty of Medical and Health Sciences, University of Copenhagen, 2200Copenhagen N, Denmark
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Hwang J, Thurmond DC. Exocytosis Proteins: Typical and Atypical Mechanisms of Action in Skeletal Muscle. Front Endocrinol (Lausanne) 2022; 13:915509. [PMID: 35774142 PMCID: PMC9238359 DOI: 10.3389/fendo.2022.915509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 05/11/2022] [Indexed: 11/18/2022] Open
Abstract
Insulin-stimulated glucose uptake in skeletal muscle is of fundamental importance to prevent postprandial hyperglycemia, and long-term deficits in insulin-stimulated glucose uptake underlie insulin resistance and type 2 diabetes. Skeletal muscle is responsible for ~80% of the peripheral glucose uptake from circulation via the insulin-responsive glucose transporter GLUT4. GLUT4 is mainly sequestered in intracellular GLUT4 storage vesicles in the basal state. In response to insulin, the GLUT4 storage vesicles rapidly translocate to the plasma membrane, where they undergo vesicle docking, priming, and fusion via the high-affinity interactions among the soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) exocytosis proteins and their regulators. Numerous studies have elucidated that GLUT4 translocation is defective in insulin resistance and type 2 diabetes. Emerging evidence also links defects in several SNAREs and SNARE regulatory proteins to insulin resistance and type 2 diabetes in rodents and humans. Therefore, we highlight the latest research on the role of SNAREs and their regulatory proteins in insulin-stimulated GLUT4 translocation in skeletal muscle. Subsequently, we discuss the novel emerging role of SNARE proteins as interaction partners in pathways not typically thought to involve SNAREs and how these atypical functions reveal novel therapeutic targets for combating peripheral insulin resistance and diabetes.
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Affiliation(s)
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, Arthur Riggs Diabetes and Metabolism Research Institute, Beckman Research Institute at City of Hope, Duarte, CA, United States
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de Wendt C, Espelage L, Eickelschulte S, Springer C, Toska L, Scheel A, Bedou AD, Benninghoff T, Cames S, Stermann T, Chadt A, Al-Hasani H. Contraction-Mediated Glucose Transport in Skeletal Muscle Is Regulated by a Framework of AMPK, TBC1D1/4, and Rac1. Diabetes 2021; 70:2796-2809. [PMID: 34561225 DOI: 10.2337/db21-0587] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/17/2021] [Indexed: 11/13/2022]
Abstract
The two closely related RabGTPase-activating proteins (RabGAPs) TBC1D1 and TBC1D4, both substrates for AMPK, play important roles in exercise metabolism and contraction-dependent translocation of GLUT4 in skeletal muscle. However, the specific contribution of each RabGAP in contraction signaling is mostly unknown. In this study, we investigated the cooperative AMPK-RabGAP signaling axis in the metabolic response to exercise/contraction using a novel mouse model deficient in active skeletal muscle AMPK combined with knockout of either Tbc1d1, Tbc1d4, or both RabGAPs. AMPK deficiency in muscle reduced treadmill exercise performance. Additional deletion of Tbc1d1 but not Tbc1d4 resulted in a further decrease in exercise capacity. In oxidative soleus muscle, AMPK deficiency reduced contraction-mediated glucose uptake, and deletion of each or both RabGAPs had no further effect. In contrast, in glycolytic extensor digitorum longus muscle, AMPK deficiency reduced contraction-stimulated glucose uptake, and deletion of Tbc1d1, but not Tbc1d4, led to a further decrease. Importantly, skeletal muscle deficient in AMPK and both RabGAPs still exhibited residual contraction-mediated glucose uptake, which was completely abolished by inhibition of the GTPase Rac1. Our results demonstrate a novel mechanistic link between glucose transport and the GTPase signaling framework in skeletal muscle in response to contraction.
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Affiliation(s)
- Christian de Wendt
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Partner Düsseldorf, München-Neuherberg, Germany
| | - Lena Espelage
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Partner Düsseldorf, München-Neuherberg, Germany
| | - Samaneh Eickelschulte
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Partner Düsseldorf, München-Neuherberg, Germany
| | - Christian Springer
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Partner Düsseldorf, München-Neuherberg, Germany
| | - Laura Toska
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Anna Scheel
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Partner Düsseldorf, München-Neuherberg, Germany
| | - Awovi Didi Bedou
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Partner Düsseldorf, München-Neuherberg, Germany
| | - Tim Benninghoff
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sandra Cames
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Torben Stermann
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Alexandra Chadt
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Partner Düsseldorf, München-Neuherberg, Germany
| | - Hadi Al-Hasani
- Institute for Clinical Biochemistry and Pathobiochemistry, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- German Center for Diabetes Research (DZD), Partner Düsseldorf, München-Neuherberg, Germany
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Gu J, Geng M, Qi M, Wang L, Zhang Y, Gao J. The role of lysosomal membrane proteins in glucose and lipid metabolism. FASEB J 2021; 35:e21848. [PMID: 34582051 DOI: 10.1096/fj.202002602r] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 07/11/2021] [Accepted: 07/26/2021] [Indexed: 11/11/2022]
Abstract
Lysosomes have long been regarded as the "garbage dump" of the cell. More recently, however, researchers have revealed novel roles for lysosomal membranes in autophagy, ion transport, nutrition sensing, and membrane fusion and repair. With active research into lysosomal membrane proteins (LMP), increasing evidence has become available showing that LMPs are inextricably linked to glucose and lipid metabolism, and this relationship represents mutual influence and regulation. In this review, we summarize the roles of LMPs in relation to glucose and lipid metabolism, and describe their roles in glucose transport, glycolysis, cholesterol transport, and lipophagy. The role of transport proteins can be traced back to the original discoveries of GLUT8, NPC1, and NPC2, which were all found to have significant roles in the pathways involved in glucose and lipid metabolism. CLC-5 and SIDT2-knockout animals show serious phenotypic disorders of metabolism, and V-ATPase and LAMP-2 have been found to interact with proteins related to glucose and lipid metabolism. These findings all emphasize the critical role of LMPs in glycolipid metabolism and help to strengthen our understanding of the independent and close relationship between LMPs and glycolipid metabolism.
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Affiliation(s)
- Jing Gu
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
| | - Mengya Geng
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- School of Clinical Medicine, Wannan Medical College, Wuhu, China
| | - Mengxiang Qi
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- School of Clinical Medicine, Wannan Medical College, Wuhu, China
| | - Lizhuo Wang
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- Department of Biochemistry and Molecular Biology, Wannan Medical College, Wuhu, China
| | - Yao Zhang
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
- Department of Biochemistry and Molecular Biology, Wannan Medical College, Wuhu, China
| | - Jialin Gao
- Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Institute of Endocrine and Metabolic Diseases, Department of Endocrinology and Genetic Metabolism, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, China
- Anhui Province Key Laboratory of Biological Macro-Molecules Research (Wannan Medical College), Wannan Medical College, Wuhu, China
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5
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Rahimi R, Malek I, Lerrer-Goldshtein T, Elkis Y, Shoval I, Jacob A, Shpungin S, Nir U. TMF1 is upregulated by insulin and is required for a sustained glucose homeostasis. FASEB J 2021; 35:e21295. [PMID: 33475194 DOI: 10.1096/fj.202001995r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 11/20/2020] [Accepted: 12/07/2020] [Indexed: 01/14/2023]
Abstract
Insulin-regulated glucose homeostasis is a critical and intricate physiological process, of which not all regulatory components have been deciphered. One of the key players in modulating glucose uptake by cells is the glucose transporter-GLUT4. In this study, we aimed to explore the regulatory role of the trans-Golgi-associated protein-TATA Element Modulatory Factor (TMF1) in the GLUT4 mediated, insulin-directed glucose uptake. By establishing and using TMF1-/- myoblasts and mice, we examined the effect of TMF1 absence on the insulin driven functioning of GLUT4. We show that TMF1 is upregulated by insulin in myoblasts, and is essential for the formation of insulin responsive, glucose transporter GLUT4-containing vesicles. Absence of TMF1 leads to the retention of GLUT4 in perinuclear compartments, and to severe impairment of insulin-stimulated GLUT4 trafficking throughout the cytoplasm and to the cell plasma membrane. Accordingly, glucose uptake is impaired in TMF1-/- cells, and TMF1-/- mice are hyperglycemic. This is reflected by the mice impaired blood glucose clearance and increased blood glucose level. Correspondingly, TMF1-/- animals are leaner than their normal littermates. Thus, TMF1 is a novel effector of insulin-regulated glucose homeostasis, and dys-functioning of this protein may contribute to the onset of a diabetes-like disorder.
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Affiliation(s)
- Roni Rahimi
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Israel Malek
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Tali Lerrer-Goldshtein
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Yoav Elkis
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Irit Shoval
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Avi Jacob
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Sally Shpungin
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Uri Nir
- The Mina and Everard Goodman Faculty of Life-Sciences, Bar-Ilan University, Ramat-Gan, Israel
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Shu H, Peng Y, Hang W, Nie J, Zhou N, Wang DW. The role of CD36 in cardiovascular disease. Cardiovasc Res 2020; 118:115-129. [PMID: 33210138 PMCID: PMC8752351 DOI: 10.1093/cvr/cvaa319] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/29/2020] [Indexed: 12/13/2022] Open
Abstract
CD36, also known as the scavenger receptor B2, is a multifunctional receptor widely expressed in various organs. CD36 plays a crucial role in the uptake of long-chain fatty acids, the main metabolic substrate in myocardial tissue. The maturation and transportation of CD36 is regulated by post-translational modifications, including phosphorylation, ubiquitination, glycosylation, and palmitoylation. CD36 is decreased in pathological cardiac hypertrophy caused by ischaemia-reperfusion and pressure overload, and increased in diabetic cardiomyopathy and atherosclerosis. Deficiency of CD36 alleviates diabetic cardiomyopathy and atherosclerosis, while overexpression of CD36 eliminates ischaemia-reperfusion damage, together suggesting that CD36 is closely associated with the progression of cardiovascular diseases and may be a new therapeutic target. This review summarizes the regulation and post-translational modifications of CD36 and evaluates its role in cardiovascular diseases and its potential as a therapeutic target.
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Affiliation(s)
- Hongyang Shu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan 430000, China
| | - Yizhong Peng
- Department of Orthopedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China
| | - Weijian Hang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan 430000, China
| | - Jiali Nie
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan 430000, China
| | - Ning Zhou
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan 430000, China
| | - Dao Wen Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan 430000, China
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7
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Abstract
The skeletal muscle is the largest organ in the body, by mass. It is also the regulator of glucose homeostasis, responsible for 80% of postprandial glucose uptake from the circulation. Skeletal muscle is essential for metabolism, both for its role in glucose uptake and its importance in exercise and metabolic disease. In this article, we give an overview of the importance of skeletal muscle in metabolism, describing its role in glucose uptake and the diseases that are associated with skeletal muscle metabolic dysregulation. We focus on the role of skeletal muscle in peripheral insulin resistance and the potential for skeletal muscle-targeted therapeutics to combat insulin resistance and diabetes, as well as other metabolic diseases like aging and obesity. In particular, we outline the possibilities and pitfalls of the quest for exercise mimetics, which are intended to target the molecular mechanisms underlying the beneficial effects of exercise on metabolic disease. We also provide a description of the molecular mechanisms that regulate skeletal muscle glucose uptake, including a focus on the SNARE proteins, which are essential regulators of glucose transport into the skeletal muscle. © 2020 American Physiological Society. Compr Physiol 10:785-809, 2020.
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Affiliation(s)
- Karla E. Merz
- Department of Molecular and Cellular Endocrinology, City of Hope Beckman Research Institute, Duarte, California, USA
- The Irell and Manella Graduate School of Biological Sciences, City of Hope, Duarte, California, USA
| | - Debbie C. Thurmond
- Department of Molecular and Cellular Endocrinology, City of Hope Beckman Research Institute, Duarte, California, USA
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8
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Luiken JJFP, Nabben M, Neumann D, Glatz JFC. Understanding the distinct subcellular trafficking of CD36 and GLUT4 during the development of myocardial insulin resistance. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165775. [PMID: 32209364 DOI: 10.1016/j.bbadis.2020.165775] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/12/2020] [Accepted: 03/17/2020] [Indexed: 01/06/2023]
Abstract
CD36 and GLUT4 are the main cardiac trans-sarcolemmal transporters for long-chain fatty acids and glucose, respectively. Together they secure the majority of cardiac energy demands. Moreover, these transporters each represent key governing kinetic steps in cardiac fatty acid and glucose fluxes, thereby offering major sites of regulation. The underlying mechanism of this regulation involves a perpetual vesicle-mediated trafficking (recycling) of both transporters between intracellular stores (endosomes) and the cell surface. In the healthy heart, CD36 and GLUT4 translocation to the cell surface is under short-term control of the same physiological stimuli, most notably increased contraction and insulin secretion. However, under chronic lipid overload, a condition that accompanies a Western lifestyle, CD36 and GLUT4 recycling are affected distinctly, with CD36 being expelled to the sarcolemma while GLUT4 is imprisoned within the endosomes. Moreover, the increased CD36 translocation towards the cell surface is a key early step, setting the heart on a route towards insulin resistance and subsequent contractile dysfunction. Therefore, the proteins making up the trafficking machinery of CD36 need to be identified with special focus to the differences with the protein composition of the GLUT4 trafficking machinery. These proteins that are uniquely dedicated to either CD36 or GLUT4 traffic may offer targets to rectify aberrant substrate uptake seen in the lipid-overloaded heart. Specifically, CD36-dedicated trafficking regulators should be inhibited, whereas such GLUT4-dedicated proteins would need to be activated. Recent advances in the identification of CD36-dedicated trafficking proteins have disclosed the involvement of vacuolar-type H+-ATPase and of specific vesicle-associated membrane proteins (VAMPs). In this review, we summarize these recent findings and sketch a roadmap of CD36 and GLUT4 trafficking compatible with experimental findings.
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Affiliation(s)
- Joost J F P Luiken
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands.
| | - Miranda Nabben
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; Department of Clinical Genetics, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre, 6211 LK Maastricht, the Netherlands
| | - Dietbert Neumann
- Department of Pathology, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Centre, 6211 LK Maastricht, the Netherlands
| | - Jan F C Glatz
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands; Department of Clinical Genetics, Faculty of Health, Medicine and Life Sciences, Maastricht University Medical Centre, 6211 LK Maastricht, the Netherlands
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9
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Knudsen JR, Henriquez-Olguin C, Li Z, Jensen TE. Electroporated GLUT4-7myc-GFP detects in vivo glucose transporter 4 translocation in skeletal muscle without discernible changes in GFP patterns. Exp Physiol 2019; 104:704-714. [PMID: 30710396 DOI: 10.1113/ep087545] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/01/2019] [Indexed: 12/22/2022]
Abstract
NEW FINDINGS What is the central question of this study? Resolving the mechanism(s) leading to glucose transporter 4 (GLUT4) translocation to the muscle surface membrane has great therapeutic potential. However, the measurement of GLUT4 translocation is technically challenging. Here, we asked whether electroporation of GLUT4-7myc-GFP into skeletal muscle could be used as a tool to study GLUT4 translocation in vivo. What is the main finding and its importance? By acutely inducing GLUT4-7myc-GFP expression in skeletal muscle, we verified that in vivo exercise and AICAR stimulation increased the GLUT4 presence in the sarcolemma measured as myc signal. Importantly, the increased myc signal in the sarcolemma was not accompanied by major visual changes in the distribution of the GFP signal. ABSTRACT Insulin and exercise lead to translocation of the glucose transporter 4 (GLUT4) to the surface membrane of skeletal muscle fibres. This process is pivotal for facilitating glucose uptake into skeletal muscle. To study this, a robust assay is needed to measure the translocation of GLUT4 in adult skeletal muscle directly. Here, we aimed to validate a simple GLUT4 translocation assay using a genetically encoded biosensor in mouse skeletal muscle. We transfected GLUT4-7myc-GFP into mouse muscle to study live GLUT4 movement and to evaluate GLUT4 insertion in the muscle surface membrane after in vivo running exercise and pharmacological activation of AMP-activated protein kinase (AMPK). Transfection led to expression of GLUT4-7myc-GFP that was dynamic in live flexor digitorum brevis fibres and which, upon insulin stimulation, exposed the myc epitope extracellularly. Running exercise, in addition to AMPK activation by 5-aminoimidazole-4-carboxamide ribonucleotide, induced ∼125 and ∼100% increase, respectively, in extracellularly exposure of GLUT4 in the surface membrane of tibialis anterior muscle. Interestingly, the clear increase in surface-exposed GLUT4 content induced by insulin, exercise or AMPK activation was not accompanied by any discernible reorganization of the GLUT4-GFP signal. In conclusion, we provide a detailed description of an easy-to-use translocation assay to study GLUT4 accumulation at the surface membrane induced by exercise and exercise-mimicking stimuli. Notably, our analyses revealed that increased GLUT4 surface membrane accumulation was not accompanied by a discernible change in the GLUT4 localization pattern.
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Affiliation(s)
- Jonas Roland Knudsen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Carlos Henriquez-Olguin
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Zhencheng Li
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Elbenhardt Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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10
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In vitro experimental models for examining the skeletal muscle cell biology of exercise: the possibilities, challenges and future developments. Pflugers Arch 2018; 471:413-429. [PMID: 30291430 DOI: 10.1007/s00424-018-2210-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/18/2018] [Accepted: 09/25/2018] [Indexed: 12/11/2022]
Abstract
Exercise provides a cornerstone in the prevention and treatment of several chronic diseases. The use of in vivo exercise models alone cannot fully establish the skeletal muscle-specific mechanisms involved in such health-promoting effects. As such, models that replicate exercise-like effects in vitro provide useful tools to allow investigations that are not otherwise possible in vivo. In this review, we provide an overview of experimental models currently used to induce exercise-like effects in skeletal muscle in vitro. In particular, the appropriateness of electrical pulse stimulation and several pharmacological compounds to resemble exercise, as well as important technical considerations, are addressed. Each model covered herein provides a useful tool to investigate different aspects of exercise with a level of abstraction not possible in vivo. That said, none of these models are perfect under all circumstances, and the choice of model (and terminology) used should be informed by the specific research question whilst accounting for the several inherent limitations of each model. Further work is required to develop and optimise the current experimental models used, such as combination with complementary techniques during treatment, and thereby improve their overall utility and impact within muscle biology research.
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11
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Perrin L, Loizides-Mangold U, Chanon S, Gobet C, Hulo N, Isenegger L, Weger BD, Migliavacca E, Charpagne A, Betts JA, Walhin JP, Templeman I, Stokes K, Thompson D, Tsintzas K, Robert M, Howald C, Riezman H, Feige JN, Karagounis LG, Johnston JD, Dermitzakis ET, Gachon F, Lefai E, Dibner C. Transcriptomic analyses reveal rhythmic and CLOCK-driven pathways in human skeletal muscle. eLife 2018; 7:34114. [PMID: 29658882 PMCID: PMC5902165 DOI: 10.7554/elife.34114] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/04/2018] [Indexed: 02/06/2023] Open
Abstract
Circadian regulation of transcriptional processes has a broad impact on cell metabolism. Here, we compared the diurnal transcriptome of human skeletal muscle conducted on serial muscle biopsies in vivo with profiles of human skeletal myotubes synchronized in vitro. More extensive rhythmic transcription was observed in human skeletal muscle compared to in vitro cell culture as a large part of the in vivo mRNA rhythmicity was lost in vitro. siRNA-mediated clock disruption in primary myotubes significantly affected the expression of ~8% of all genes, with impact on glucose homeostasis and lipid metabolism. Genes involved in GLUT4 expression, translocation and recycling were negatively affected, whereas lipid metabolic genes were altered to promote activation of lipid utilization. Moreover, basal and insulin-stimulated glucose uptake were significantly reduced upon CLOCK depletion. Our findings suggest an essential role for the circadian coordination of skeletal muscle glucose homeostasis and lipid metabolism in humans.
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Affiliation(s)
- Laurent Perrin
- Division of Endocrinology, Diabetes, Hypertension and Nutrition, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland.,Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Diabetes Center, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, Geneva, Switzerland
| | - Ursula Loizides-Mangold
- Division of Endocrinology, Diabetes, Hypertension and Nutrition, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland.,Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Diabetes Center, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, Geneva, Switzerland
| | | | - Cédric Gobet
- Nestlé Institute of Health Sciences, Lausanne, Switzerland.,School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Nicolas Hulo
- Institute of Genetics and Genomics of Geneva, Geneva, Switzerland.,Service for Biomathematical and Biostatistical Analyses, Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland
| | - Laura Isenegger
- Service for Biomathematical and Biostatistical Analyses, Institute of Genetics and Genomics in Geneva, University of Geneva, Geneva, Switzerland
| | | | | | | | - James A Betts
- Department for Health, University of Bath, Bath, United Kingdom
| | | | - Iain Templeman
- Department for Health, University of Bath, Bath, United Kingdom
| | - Keith Stokes
- Department for Health, University of Bath, Bath, United Kingdom
| | - Dylan Thompson
- Department for Health, University of Bath, Bath, United Kingdom
| | - Kostas Tsintzas
- MRC/ARUK Centre for Musculoskeletal Ageing, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Maud Robert
- Department of Digestive and Bariatric Surgery, Edouard Herriot University Hospital, Lyon, France
| | - Cedric Howald
- Institute of Genetics and Genomics of Geneva, Geneva, Switzerland.,Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Howard Riezman
- Department of Biochemistry, NCCR Chemical Biology, University of Geneva, Geneva, Switzerland
| | - Jerome N Feige
- Nestlé Institute of Health Sciences, Lausanne, Switzerland.,School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Leonidas G Karagounis
- Experimental Myology and Integrative Biology Research Cluster, Faculty of Sport and Health Sciences, University of St Mark and St John, Plymouth, United Kingdom.,Institute of Nutritional Science, Nestlé Research Centre, Lausanne, Switzerland
| | - Jonathan D Johnston
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Emmanouil T Dermitzakis
- Institute of Genetics and Genomics of Geneva, Geneva, Switzerland.,Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Frédéric Gachon
- Nestlé Institute of Health Sciences, Lausanne, Switzerland.,School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | | | - Charna Dibner
- Division of Endocrinology, Diabetes, Hypertension and Nutrition, Department of Internal Medicine Specialties, University Hospital of Geneva, Geneva, Switzerland.,Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Diabetes Center, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, Geneva, Switzerland
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12
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Nikolić N, Görgens SW, Thoresen GH, Aas V, Eckel J, Eckardt K. Electrical pulse stimulation of cultured skeletal muscle cells as a model for in vitro exercise - possibilities and limitations. Acta Physiol (Oxf) 2017; 220:310-331. [PMID: 27863008 DOI: 10.1111/apha.12830] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 06/28/2016] [Accepted: 11/06/2016] [Indexed: 12/19/2022]
Abstract
The beneficial health-related effects of exercise are well recognized, and numerous studies have investigated underlying mechanism using various in vivo and in vitro models. Although electrical pulse stimulation (EPS) for the induction of muscle contraction has been used for quite some time, its application on cultured skeletal muscle cells of animal or human origin as a model of in vitro exercise is a more recent development. In this review, we compare in vivo exercise and in vitro EPS with regard to effects on signalling, expression level and metabolism. We provide a comprehensive overview of different EPS protocols and their applications, discuss technical aspects of this model including critical controls and the importance of a proper maintenance procedure and finally discuss the limitations of the EPS model.
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Affiliation(s)
- N. Nikolić
- Department of Pharmaceutical Biosciences; School of Pharmacy; University of Oslo; Oslo Norway
| | - S. W. Görgens
- Paul-Langerhans-Group for Integrative Physiology; German Diabetes Center; Düsseldorf Germany
| | - G. H. Thoresen
- Department of Pharmaceutical Biosciences; School of Pharmacy; University of Oslo; Oslo Norway
- Department of Pharmacology; Institute of Clinical Medicine; Faculty of Medicine; University of Oslo; Oslo Norway
| | - V. Aas
- Department of Life Sciences and Health; Oslo and Akershus University College of Applied Sciences; Oslo Norway
| | - J. Eckel
- Paul-Langerhans-Group for Integrative Physiology; German Diabetes Center; Düsseldorf Germany
- German Center for Diabetes Research (DZD e.V.); Düsseldorf Germany
| | - K. Eckardt
- Department of Nutrition; Institute for Basic Medical Sciences; Faculty of Medicine; University of Oslo; Oslo Norway
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13
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VAMP2 is implicated in the secretion of antibodies by human plasma cells and can be replaced by other synaptobrevins. Cell Mol Immunol 2016; 15:353-366. [PMID: 27616736 DOI: 10.1038/cmi.2016.46] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 07/06/2016] [Accepted: 07/06/2016] [Indexed: 11/08/2022] Open
Abstract
The production and secretion of antibodies by human plasma cells (PCs) are two essential processes of humoral immunity. The secretion process relies on a group of proteins known as soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs), which are located in the plasma membrane (t-SNAREs) and in the antibody-carrying vesicle membrane (v-SNARE), and mediate the fusion of both membranes. We have previously shown that SNAP23 and STX4 are the t-SNAREs responsible for antibody secretion. Here, using human PCs and antibody-secreting cell lines, we studied and characterized the expression and subcellular distribution of vesicle associated membrane protein (VAMP) isoforms, demonstrating that all isoforms (with the exception of VAMP1) are expressed by the referenced cells. Furthermore, the functional role in antibody secretion of each expressed VAMP isoform was tested using siRNA. Our results show that VAMP2 may be the v-SNARE involved in vesicular antibody release. To further support this conclusion, we used tetanus toxin light chain to cleave VAMP2, conducted experiments to verify co-localization of VAMP2 in antibody-carrying vesicles, and demonstrated the coimmunoprecipitation of VAMP2 with STX4 and SNAP23 and the in situ interaction of VAMP2 with STX4. Taken together, these findings implicate VAMP2 as the main VAMP isoform functionally involved in antibody secretion.
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14
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Regulation of Carbohydrate Metabolism, Lipid Metabolism, and Protein Metabolism by AMPK. EXPERIENTIA SUPPLEMENTUM (2012) 2016; 107:23-43. [PMID: 27812975 DOI: 10.1007/978-3-319-43589-3_2] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This chapter summarizes AMPK function in the regulation of substrate and energy metabolism with the main emphasis on carbohydrate and lipid metabolism, protein turnover, mitochondrial biogenesis, and whole-body energy homeostasis. AMPK acts as whole-body energy sensor and integrates different signaling pathway to meet both cellular and body energy requirements while inhibiting energy-consuming processes but also activating energy-producing ones. AMPK mainly promotes glucose and fatty acid catabolism, whereas it prevents protein, glycogen, and fatty acid synthesis.
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15
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Organization of organelles and VAMP-associated vesicular transport systems in differentiating skeletal muscle cells. Anat Sci Int 2014; 90:33-9. [DOI: 10.1007/s12565-014-0266-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2014] [Accepted: 11/19/2014] [Indexed: 10/24/2022]
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16
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Kioumourtzoglou D, Sadler JBA, Black HL, Berends R, Wellburn C, Bryant NJ, Gould GW. Studies of the regulated assembly of SNARE complexes in adipocytes. Biochem Soc Trans 2014; 42:1396-400. [PMID: 25233421 DOI: 10.1042/bst20140114] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/01/2024]
Abstract
Insulin plays a fundamental role in whole-body glucose homeostasis. Central to this is the hormone's ability to rapidly stimulate the rate of glucose transport into adipocytes and muscle cells [1]. Upon binding its receptor, insulin stimulates an intracellular signalling cascade that culminates in redistribution of glucose transporter proteins, specifically the GLUT4 isoform, from intracellular stores to the plasma membrane, a process termed 'translocation' [1,2]. This is an example of regulated membrane trafficking [3], a process that also underpins other aspects of physiology in a number of specialized cell types, for example neurotransmission in brain/neurons and release of hormone-containing vesicles from specialized secretory cells such as those found in pancreatic islets. These processes invoke a number of intriguing biological questions as follows. How is the machinery involved in these membrane trafficking events mobilized in response to a stimulus? How do the signalling pathways that detect the external stimulus interface with the trafficking machinery? Recent studies of insulin-stimulated GLUT4 translocation offer insight into such questions. In the present paper, we have reviewed these studies and draw parallels with other regulated trafficking systems.
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Affiliation(s)
- Dimitrios Kioumourtzoglou
- *Henry Wellcome Laboratory of Cell Biology, Institute for Molecular, Cell and Systems Biology, Davidson Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, U.K
| | - Jessica B A Sadler
- *Henry Wellcome Laboratory of Cell Biology, Institute for Molecular, Cell and Systems Biology, Davidson Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, U.K
| | - Hannah L Black
- †Department of Biology, University of York, Heslington, York YO10 5DD, U.K
| | - Rebecca Berends
- *Henry Wellcome Laboratory of Cell Biology, Institute for Molecular, Cell and Systems Biology, Davidson Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, U.K
| | - Cassie Wellburn
- *Henry Wellcome Laboratory of Cell Biology, Institute for Molecular, Cell and Systems Biology, Davidson Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, U.K
| | - Nia J Bryant
- †Department of Biology, University of York, Heslington, York YO10 5DD, U.K
| | - Gwyn W Gould
- *Henry Wellcome Laboratory of Cell Biology, Institute for Molecular, Cell and Systems Biology, Davidson Building, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, U.K
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17
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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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18
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Abstract
Glucose is an important fuel for contracting muscle, and normal glucose metabolism is vital for health. Glucose enters the muscle cell via facilitated diffusion through the GLUT4 glucose transporter which translocates from intracellular storage depots to the plasma membrane and T-tubules upon muscle contraction. Here we discuss the current understanding of how exercise-induced muscle glucose uptake is regulated. We briefly discuss the role of glucose supply and metabolism and concentrate on GLUT4 translocation and the molecular signaling that sets this in motion during muscle contractions. Contraction-induced molecular signaling is complex and involves a variety of signaling molecules including AMPK, Ca(2+), and NOS in the proximal part of the signaling cascade as well as GTPases, Rab, and SNARE proteins and cytoskeletal components in the distal part. While acute regulation of muscle glucose uptake relies on GLUT4 translocation, glucose uptake also depends on muscle GLUT4 expression which is increased following exercise. AMPK and CaMKII are key signaling kinases that appear to regulate GLUT4 expression via the HDAC4/5-MEF2 axis and MEF2-GEF interactions resulting in nuclear export of HDAC4/5 in turn leading to histone hyperacetylation on the GLUT4 promoter and increased GLUT4 transcription. Exercise training is the most potent stimulus to increase skeletal muscle GLUT4 expression, an effect that may partly contribute to improved insulin action and glucose disposal and enhanced muscle glycogen storage following exercise training in health and disease.
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Affiliation(s)
- Erik A Richter
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
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19
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Lauritzen HP, Brandauer J, Schjerling P, Koh HJ, Treebak JT, Hirshman MF, Galbo H, Goodyear LJ. Contraction and AICAR stimulate IL-6 vesicle depletion from skeletal muscle fibers in vivo. Diabetes 2013; 62:3081-92. [PMID: 23761105 PMCID: PMC3749330 DOI: 10.2337/db12-1261] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recent studies suggest that interleukin 6 (IL-6) is released from contracting skeletal muscles; however, the cellular origin, secretion kinetics, and signaling mechanisms regulating IL-6 secretion are unknown. To address these questions, we developed imaging methodology to study IL-6 in fixed mouse muscle fibers and in live animals in vivo. Using confocal imaging to visualize endogenous IL-6 protein in fixed muscle fibers, we found IL-6 in small vesicle structures distributed throughout the fibers under basal (resting) conditions. To determine the kinetics of IL-6 secretion, intact quadriceps muscles were transfected with enhanced green fluorescent protein (EGFP)-tagged IL-6 (IL-6-EGFP), and 5 days later anesthetized mice were imaged before and after muscle contractions in situ. Contractions decreased IL-6-EGFP-containing vesicles and protein by 62% (P < 0.05), occurring rapidly and progressively over 25 min of contraction. However, contraction-mediated IL-6-EGFP reduction was normal in muscle-specific AMP-activated protein kinase (AMPK) α2-inactive transgenic mice. In contrast, the AMPK activator AICAR decreased IL-6-EGFP vesicles, an effect that was inhibited in the transgenic mice. In conclusion, resting skeletal muscles contain IL-6-positive vesicles that are expressed throughout myofibers. Contractions stimulate the rapid reduction of IL-6 in myofibers, occurring through an AMPKα2-independent mechanism. This novel imaging methodology clearly establishes IL-6 as a contraction-stimulated myokine and can be used to characterize the secretion kinetics of other putative myokines.
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Affiliation(s)
- Hans P.M.M. Lauritzen
- Research Division, Joslin Diabetes Center and Harvard Medical School, Boston, Massachusetts
| | - Josef Brandauer
- Department of Health Sciences, Gettysburg College, Gettysburg, Pennsylvania
| | - Peter Schjerling
- Department of Orthopedic Surgery M, Institute of Sports Medicine, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ho-Jin Koh
- Research Division, Joslin Diabetes Center and Harvard Medical School, Boston, Massachusetts
| | - Jonas T. Treebak
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael F. Hirshman
- Research Division, Joslin Diabetes Center and Harvard Medical School, Boston, Massachusetts
| | - Henrik Galbo
- Department of Rheumatology and Institute of Inflammation Research, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Laurie J. Goodyear
- Research Division, Joslin Diabetes Center and Harvard Medical School, Boston, Massachusetts
- Corresponding author: Laurie J. Goodyear,
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20
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Aas V, Bakke SS, Feng YZ, Kase ET, Jensen J, Bajpeyi S, Thoresen GH, Rustan AC. Are cultured human myotubes far from home? Cell Tissue Res 2013; 354:671-82. [PMID: 23749200 DOI: 10.1007/s00441-013-1655-1] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 05/03/2013] [Indexed: 12/25/2022]
Abstract
Satellite cells can be isolated from skeletal muscle biopsies, activated to proliferating myoblasts and differentiated into multinuclear myotubes in culture. These cell cultures represent a model system for intact human skeletal muscle and can be modulated ex vivo. The advantages of this system are that the most relevant genetic background is available for the investigation of human disease (as opposed to rodent cell cultures), the extracellular environment can be precisely controlled and the cells are not immortalized, thereby offering the possibility of studying innate characteristics of the donor. Limitations in differentiation status (fiber type) of the cells and energy metabolism can be improved by proper treatment, such as electrical pulse stimulation to mimic exercise. This review focuses on the way that human myotubes can be employed as a tool for studying metabolism in skeletal muscles, with special attention to changes in muscle energy metabolism in obesity and type 2 diabetes.
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Affiliation(s)
- Vigdis Aas
- Institute of Pharmacy and Biomedical Laboratory Science, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, Oslo, Norway,
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21
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Sylow L, Jensen TE, Kleinert M, Mouatt JR, Maarbjerg SJ, Jeppesen J, Prats C, Chiu TT, Boguslavsky S, Klip A, Schjerling P, Richter EA. Rac1 is a novel regulator of contraction-stimulated glucose uptake in skeletal muscle. Diabetes 2013; 62:1139-51. [PMID: 23274900 PMCID: PMC3609592 DOI: 10.2337/db12-0491] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In skeletal muscle, the actin cytoskeleton-regulating GTPase, Rac1, is necessary for insulin-dependent GLUT4 translocation. Muscle contraction increases glucose transport and represents an alternative signaling pathway to insulin. Whether Rac1 is activated by muscle contraction and regulates contraction-induced glucose uptake is unknown. Therefore, we studied the effects of in vivo exercise and ex vivo muscle contractions on Rac1 signaling and its regulatory role in glucose uptake in mice and humans. Muscle Rac1-GTP binding was increased after exercise in mice (~60-100%) and humans (~40%), and this activation was AMP-activated protein kinase independent. Rac1 inhibition reduced contraction-stimulated glucose uptake in mouse muscle by 55% in soleus and by 20-58% in extensor digitorum longus (EDL; P < 0.01). In agreement, the contraction-stimulated increment in glucose uptake was decreased by 27% (P = 0.1) and 40% (P < 0.05) in soleus and EDL muscles, respectively, of muscle-specific inducible Rac1 knockout mice. Furthermore, depolymerization of the actin cytoskeleton decreased contraction-stimulated glucose uptake by 100% and 62% (P < 0.01) in soleus and EDL muscles, respectively. These are the first data to show that Rac1 is activated during muscle contraction in murine and human skeletal muscle and suggest that Rac1 and possibly the actin cytoskeleton are novel regulators of contraction-stimulated glucose uptake.
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Affiliation(s)
- Lykke Sylow
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E. Jensen
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Maximilian Kleinert
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Joshua R. Mouatt
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | | | - Jacob Jeppesen
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Clara Prats
- Department of Biomedical Sciences, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Tim T. Chiu
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Shlomit Boguslavsky
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Amira Klip
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopedic Surgery, Bispebjerg Hospital and Center for Healthy Aging, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Erik A. Richter
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
- Corresponding author: Erik A. Richter,
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23
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Schwenk RW, Angin Y, Steinbusch LKM, Dirkx E, Hoebers N, Coumans WA, Bonen A, Broers JLV, van Eys GJJM, Glatz JFC, Luiken JJFP. Overexpression of vesicle-associated membrane protein (VAMP) 3, but not VAMP2, protects glucose transporter (GLUT) 4 protein translocation in an in vitro model of cardiac insulin resistance. J Biol Chem 2012; 287:37530-9. [PMID: 22936810 DOI: 10.1074/jbc.m112.363630] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cardiac glucose utilization is regulated by reversible translocation of the glucose transporter GLUT4 from intracellular stores to the plasma membrane. During the onset of diet-induced insulin resistance, elevated lipid levels in the circulation interfere with insulin-stimulated GLUT4 translocation, leading to impaired glucose utilization. Recently, we identified vesicle-associated membrane protein (VAMP) 2 and 3 to be required for insulin- and contraction-stimulated GLUT4 translocation, respectively, in cardiomyocytes. Here, we investigated whether overexpression of VAMP2 and/or VAMP3 could protect insulin-stimulated GLUT4 translocation under conditions of insulin resistance. HL-1 atrial cardiomyocytes transiently overexpressing either VAMP2 or VAMP3 were cultured for 16 h with elevated concentrations of palmitate and insulin. Upon subsequent acute stimulation with insulin, we measured GLUT4 translocation, plasmalemmal presence of the fatty acid transporter CD36, and myocellular lipid accumulation. Overexpression of VAMP3, but not VAMP2, completely prevented lipid-induced inhibition of insulin-stimulated GLUT4 translocation. Furthermore, the plasmalemmal presence of CD36 and intracellular lipid levels remained normal in cells overexpressing VAMP3. However, insulin signaling was not retained, indicating an effect of VAMP3 overexpression downstream of PKB/Akt. Furthermore, we revealed that endogenous VAMP3 is bound by the contraction-activated protein kinase D (PKD), and contraction and VAMP3 overexpression protect insulin-stimulated GLUT4 translocation via a common mechanism. These observations indicate that PKD activates GLUT4 translocation via a VAMP3-dependent trafficking step, which pathway might be valuable to rescue constrained glucose utilization in the insulin-resistant heart.
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Affiliation(s)
- Robert W Schwenk
- Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, P. O. Box 616, 6200 MD Maastricht, The Netherlands.
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24
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Synaptic Vesicle Proteins: Targets and Routes for Botulinum Neurotoxins. Curr Top Microbiol Immunol 2012. [DOI: 10.1007/978-3-662-45790-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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25
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Abstract
Delivery of the glucose transporter type 4 (GLUT4) from an intracellular location to the cell surface in response to insulin represents a specialized form of membrane traffic, known to be impaired in the disease states of insulin resistance and type 2 diabetes. Like all membrane trafficking events, this translocation of GLUT4 requires members of the SNARE family of proteins. Here, we discuss two SNARE complexes that have been implicated in insulin-regulated GLUT4 traffic: one regulating the final delivery of GLUT4 to the cell surface in response to insulin and the other controlling GLUT4's intracellular trafficking.
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Affiliation(s)
- Nia J Bryant
- Henry Wellcome Laboratory of Cell Biology, Institute of Molecular, Cell and Systems Biology, Davidson Building, College of Medicine, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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26
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Subcellular trafficking of the substrate transporters GLUT4 and CD36 in cardiomyocytes. Cell Mol Life Sci 2011; 68:2525-38. [PMID: 21547502 PMCID: PMC3134709 DOI: 10.1007/s00018-011-0690-x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Revised: 04/01/2011] [Accepted: 04/12/2011] [Indexed: 12/16/2022]
Abstract
Cardiomyocytes use glucose as well as fatty acids for ATP production. These substrates are transported into the cell by glucose transporter 4 (GLUT4) and the fatty acid transporter CD36. Besides being located at the sarcolemma, GLUT4 and CD36 are stored in intracellular compartments. Raised plasma insulin concentrations and increased cardiac work will stimulate GLUT4 as well as CD36 to translocate to the sarcolemma. As so far studied, signaling pathways that regulate GLUT4 translocation similarly affect CD36 translocation. During the development of insulin resistance and type 2 diabetes, CD36 becomes permanently localized at the sarcolemma, whereas GLUT4 internalizes. This juxtaposed positioning of GLUT4 and CD36 is important for aberrant substrate uptake in the diabetic heart: chronically increased fatty acid uptake at the expense of glucose. To explain the differences in subcellular localization of GLUT4 and CD36 in type 2 diabetes, recent research has focused on the role of proteins involved in trafficking of cargo between subcellular compartments. Several of these proteins appear to be similarly involved in both GLUT4 and CD36 translocation. Others, however, have different roles in either GLUT4 or CD36 translocation. These trafficking components, which are differently involved in GLUT4 or CD36 translocation, may be considered novel targets for the development of therapies to restore the imbalanced substrate utilization that occurs in obesity, insulin resistance and diabetic cardiomyopathy.
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Jeppesen J, Albers PH, Rose AJ, Birk JB, Schjerling P, Dzamko N, Steinberg GR, Kiens B. Contraction-induced skeletal muscle FAT/CD36 trafficking and FA uptake is AMPK independent. J Lipid Res 2011; 52:699-711. [PMID: 21297178 DOI: 10.1194/jlr.m007138] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aim of this study was to investigate the molecular mechanisms regulating FA translocase CD36 (FAT/CD36) translocation and FA uptake in skeletal muscle during contractions. In one model, wild-type (WT) and AMP-dependent protein kinase kinase dead (AMPK KD) mice were exercised or extensor digitorum longus (EDL) and soleus (SOL) muscles were contracted, ex vivo. In separate studies, FAT/CD36 translocation and FA uptake in response to muscle contractions were investigated in the perfused rat hindlimb. Exercise induced a similar increase in skeletal muscle cell surface membrane FAT/CD36 content in WT (+34%) and AMPK KD (+37%) mice. In contrast, 5-aminoimidazole-4-carboxamide ribonucleoside only induced an increase in cell surface FAT/CD36 content in WT (+29%) mice. Furthermore, in the perfused rat hindlimb, muscle contraction induced a rapid (1 min, +15%) and sustained (10 min, +24%) FAT/CD36 relocation to cell surface membranes. The increase in cell surface FAT/CD36 protein content with muscle contractions was associated with increased FA uptake, both in EDL and SOL muscle from WT and AMPK KD mice and in the perfused rat hindlimb. This suggests that AMPK is not essential in regulation of FAT/CD36 translocation and FA uptake in skeletal muscle during contractions. However, AMPK could be important in regulation of FAT/CD36 distribution in other physiological situations.
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Affiliation(s)
- J Jeppesen
- Copenhagen Muscle Research Center, Molecular Physiology Group, Section of Human Physiology, University of Copenhagen, Copenhagen, Denmark
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Schwenk RW, Dirkx E, Coumans WA, Bonen A, Klip A, Glatz JFC, Luiken JJFP. Requirement for distinct vesicle-associated membrane proteins in insulin- and AMP-activated protein kinase (AMPK)-induced translocation of GLUT4 and CD36 in cultured cardiomyocytes. Diabetologia 2010; 53:2209-19. [PMID: 20582536 PMCID: PMC2931635 DOI: 10.1007/s00125-010-1832-7] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 05/04/2010] [Indexed: 01/14/2023]
Abstract
AIMS/HYPOTHESIS Upon stimulation of insulin signalling or contraction-induced AMP-activated protein kinase (AMPK) activation, the glucose transporter GLUT4 and the long-chain fatty acid (LCFA) transporter CD36 similarly translocate from intracellular compartments to the plasma membrane of cardiomyocytes to increase uptake of glucose and LCFA, respectively. This similarity in regulation of GLUT4 traffic and CD36 traffic suggests that the same families of trafficking proteins, including vesicle-associated membrane proteins (VAMPs), are involved in both processes. While several VAMPs have been implicated in GLUT4 traffic, nothing is known about the putative function of VAMPs in CD36 traffic. Therefore, we compared the involvement of the myocardially produced VAMP isoforms in insulin- or contraction-induced GLUT4 and CD36 translocation. METHODS Five VAMP isoforms were silenced in HL-1 cardiomyocytes. The cells were treated with insulin or the contraction-like AMPK activator oligomycin or were electrically stimulated to contract. Subsequently, GLUT4 and CD36 translocation as well as substrate uptake were measured. RESULTS Three VAMPs were demonstrated to be necessary for both GLUT4 and CD36 translocation, either specifically in insulin-treated cells (VAMP2, VAMP5) or in oligomycin/contraction-treated cells (VAMP3). In addition, there are VAMPs specifically involved in either GLUT4 traffic (VAMP7 mediates basal GLUT4 retention) or CD36 traffic (VAMP4 mediates insulin- and oligomycin/contraction-induced CD36 translocation). CONCLUSIONS/INTERPRETATION The involvement of distinct VAMP isoforms in both GLUT4 and CD36 translocation indicates that CD36 translocation, just like GLUT4 translocation, is a vesicle-mediated process dependent on soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex formation. The ability of other VAMPs to discriminate between GLUT4 and CD36 translocation allows the notion that myocardial substrate preference can be modulated by these VAMPs.
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Affiliation(s)
- R W Schwenk
- Department of Molecular Genetics, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, P.O. Box 616, 6200 MD Maastricht, the Netherlands.
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Jewell JL, Oh E, Thurmond DC. Exocytosis mechanisms underlying insulin release and glucose uptake: conserved roles for Munc18c and syntaxin 4. Am J Physiol Regul Integr Comp Physiol 2010; 298:R517-31. [PMID: 20053958 DOI: 10.1152/ajpregu.00597.2009] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Type 2 diabetes has been coined "a two-hit disease," as it involves specific defects of glucose-stimulated insulin secretion from the pancreatic beta cells in addition to defects in peripheral tissue insulin action required for glucose uptake. Both of these processes, insulin secretion and glucose uptake, are mediated by SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein core complexes composed of syntaxin, SNAP-23/25, and VAMP proteins. The SNARE core complex is regulated by the Sec1/Munc18 (SM) family of proteins, which selectively bind to their cognate syntaxin isoforms with high affinity. The process of insulin secretion uses multiple Munc18-syntaxin isoform pairs, whereas insulin action in the peripheral tissues appears to use only the Munc18c-syntaxin 4 pair. Importantly, recent reports have linked obesity and Type 2 diabetes in humans with changes in protein levels and single nucleotide polymorphisms (SNPs) of Munc18 and syntaxin isoforms relevant to these exocytotic processes, although the molecular mechanisms underlying the observed phenotypes remain incomplete (5, 104, 144). Given the conservation of these proteins in two seemingly disparate processes and the need to design and implement novel and more effective clinical interventions, it will be vitally important to delineate the mechanisms governing these conserved SNARE-mediated exocytosis events. Thus, we provide here an up-to-date historical review of advancements in defining the roles and molecular mechanisms of Munc18-syntaxin complexes in the pathophysiology of Type 2 diabetes.
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Affiliation(s)
- Jenna L Jewell
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
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