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Simon-Szabó L, Lizák B, Sturm G, Somogyi A, Takács I, Németh Z. Molecular Aspects in the Development of Type 2 Diabetes and Possible Preventive and Complementary Therapies. Int J Mol Sci 2024; 25:9113. [PMID: 39201799 PMCID: PMC11354764 DOI: 10.3390/ijms25169113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2024] [Revised: 08/17/2024] [Accepted: 08/18/2024] [Indexed: 09/03/2024] Open
Abstract
The incidence of diabetes, including type 2 diabetes (T2DM), is increasing sharply worldwide. To reverse this, more effective approaches in prevention and treatment are needed. In our review, we sought to summarize normal insulin action and the pathways that primarily influence the development of T2DM. Normal insulin action involves mitogenic and metabolic pathways, as both are important in normal metabolic processes, regeneration, etc. However, through excess energy, both can be hyperactive or attenuated/inactive leading to disturbances in the cellular and systemic regulation with the consequence of cellular stress and systemic inflammation. In this review, we detailed the beneficial molecular changes caused by some important components of nutrition and by exercise, which act in the same molecular targets as the developed drugs, and can revert the damaged pathways. Moreover, these induce entire networks of regulatory mechanisms and proteins to restore unbalanced homeostasis, proving their effectiveness as preventive and complementary therapies. These are the main steps for success in prevention and treatment of developed diseases to rid the body of excess energy, both from stored fats and from overnutrition, while facilitating fat burning with adequate, regular exercise in healthy people, and together with necessary drug treatment as required in patients with insulin resistance and T2DM.
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Affiliation(s)
- Laura Simon-Szabó
- Department of Molecular Biology, Semmelweis University, Tuzolto u. 37-47, 1094 Budapest, Hungary; (L.S.-S.); (B.L.)
| | - Beáta Lizák
- Department of Molecular Biology, Semmelweis University, Tuzolto u. 37-47, 1094 Budapest, Hungary; (L.S.-S.); (B.L.)
| | - Gábor Sturm
- Directorate of Information Technology Basic Infrastructure and Advanced Applications, Semmelweis University, Üllői út 78/b, 1082 Budapest, Hungary;
| | - Anikó Somogyi
- Department of Internal Medicine and Hematology, Semmelweis University, Baross u., 1085 Budapest, Hungary;
| | - István Takács
- Department of Internal Medicine and Oncology, Semmelweis University, Koranyi S. u 2/a, 1083 Budapest, Hungary;
| | - Zsuzsanna Németh
- Department of Internal Medicine and Oncology, Semmelweis University, Koranyi S. u 2/a, 1083 Budapest, Hungary;
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2
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Smith JAB, Murach KA, Dyar KA, Zierath JR. Exercise metabolism and adaptation in skeletal muscle. Nat Rev Mol Cell Biol 2023; 24:607-632. [PMID: 37225892 PMCID: PMC10527431 DOI: 10.1038/s41580-023-00606-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2023] [Indexed: 05/26/2023]
Abstract
Viewing metabolism through the lens of exercise biology has proven an accessible and practical strategy to gain new insights into local and systemic metabolic regulation. Recent methodological developments have advanced understanding of the central role of skeletal muscle in many exercise-associated health benefits and have uncovered the molecular underpinnings driving adaptive responses to training regimens. In this Review, we provide a contemporary view of the metabolic flexibility and functional plasticity of skeletal muscle in response to exercise. First, we provide background on the macrostructure and ultrastructure of skeletal muscle fibres, highlighting the current understanding of sarcomeric networks and mitochondrial subpopulations. Next, we discuss acute exercise skeletal muscle metabolism and the signalling, transcriptional and epigenetic regulation of adaptations to exercise training. We address knowledge gaps throughout and propose future directions for the field. This Review contextualizes recent research of skeletal muscle exercise metabolism, framing further advances and translation into practice.
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Affiliation(s)
- Jonathon A B Smith
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Kevin A Murach
- Molecular Mass Regulation Laboratory, Exercise Science Research Center, Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR, USA
| | - Kenneth A Dyar
- Metabolic Physiology, Institute for Diabetes and Cancer, Helmholtz Diabetes Center, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Juleen R Zierath
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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3
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Chan MP, Takenaka N, Satoh T. Impaired Insulin Signaling Mediated by the Small GTPase Rac1 in Skeletal Muscle of the Leptin-Deficient Obese Mouse. Int J Mol Sci 2023; 24:11531. [PMID: 37511290 PMCID: PMC10380855 DOI: 10.3390/ijms241411531] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 07/05/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Insulin-stimulated glucose uptake in skeletal muscle is mediated by the glucose transporter GLUT4. The small GTPase Rac1 acts as a switch of signal transduction that regulates GLUT4 translocation to the plasma membrane following insulin stimulation. However, it remains obscure whether signaling cascades upstream and downstream of Rac1 in skeletal muscle are impaired by obesity that causes insulin resistance and type 2 diabetes. In an attempt to clarify this point, we investigated Rac1 signaling in the leptin-deficient (Lepob/ob) mouse model. Here, we show that insulin-stimulated GLUT4 translocation and Rac1 activation are almost completely abolished in Lepob/ob mouse skeletal muscle. Phosphorylation of the protein kinase Akt2 and plasma membrane translocation of the guanine nucleotide exchange factor FLJ00068 following insulin stimulation were also diminished in Lepob/ob mice. On the other hand, the activation of another small GTPase RalA, which acts downstream of Rac1, by the constitutively activated form of Akt2, FLJ00068, or Rac1, was partially abrogated in Lepob/ob mice. Taken together, we conclude that insulin-stimulated glucose uptake is impaired by two mechanisms in Lepob/ob mouse skeletal muscle: one is the complete inhibition of Akt2-mediated activation of Rac1, and the other is the partial inhibition of RalA activation downstream of Rac1.
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Affiliation(s)
| | | | - Takaya Satoh
- Laboratory of Cell Biology, Department of Biological Chemistry, Graduate School of Science, Osaka Metropolitan University, Sakai 599-8531, Japan; (M.P.C.); (N.T.)
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Vainshtein A, Slavin MB, Cheng AJ, Memme JM, Oliveira AN, Perry CGR, Abdul-Sater AA, Belcastro AN, Riddell MC, Triolo M, Haas TL, Roudier E, Hood DA. Scientific meeting report: International Biochemistry of Exercise 2022. J Appl Physiol (1985) 2022; 133:1381-1393. [PMID: 36356257 DOI: 10.1152/japplphysiol.00475.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Exercise is one of the only nonpharmacological remedies known to counteract genetic and chronic diseases by enhancing health and improving life span. Although the many benefits of regular physical activity have been recognized for some time, the intricate and complex signaling systems triggered at the onset of exercise have only recently begun to be uncovered. Exercising muscles initiate a coordinated, multisystemic, metabolic rewiring, which is communicated to distant organs by various molecular mediators. The field of exercise research has been expanding beyond the musculoskeletal system, with interest from industry to provide realistic models and exercise mimetics that evoke a whole body rejuvenation response. The 18th International Biochemistry of Exercise conference took place in Toronto, Canada, from May 25 to May 28, 2022, with more than 400 attendees. Here, we provide an overview of the most cutting-edge exercise-related research presented by 66 speakers, focusing on new developments in topics ranging from molecular and cellular mechanisms of exercise adaptations to exercise therapy and management of disease and aging. We also describe how the manipulation of these signaling pathways can uncover therapeutic avenues for improving human health and quality of life.
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Affiliation(s)
| | - Mikhaela B Slavin
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Arthur J Cheng
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Jonathan M Memme
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Ashley N Oliveira
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Christopher G R Perry
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Ali A Abdul-Sater
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Angelo N Belcastro
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Michael C Riddell
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Matthew Triolo
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Tara L Haas
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - Emilie Roudier
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
| | - David A Hood
- Faculty of Health, School of Kinesiology and Health Science, Muscle Health Research Centre (MHRC), York University, Toronto, Ontario, Canada
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Liu S, Qi R, Zhang J, Zhang C, Chen L, Yao Z, Niu W. Kalirin mediates Rac1 activation downstream of calcium/calmodulin-dependent protein kinase II to stimulate glucose uptake during muscle contraction. FEBS Lett 2022; 596:3159-3175. [PMID: 35716086 DOI: 10.1002/1873-3468.14428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 04/14/2022] [Accepted: 05/16/2022] [Indexed: 01/14/2023]
Abstract
In this study, we investigated the role of calcium/calmodulin-dependent protein kinase II (CaMKII) in contraction-stimulated glucose uptake in skeletal muscle. C2C12 myotubes were contracted by electrical pulse stimulation (EPS), and treadmill running was used to exercise mice. The activities of CaMKII, the small G protein Rac1, and the Rac1 effector kinase PAK1 were elevated in muscle by running exercise or EPS, while they were lowered by the CaMKII inhibitor KN-93 and/or small interfering RNA (siRNA)-mediated knockdown. EPS induced the mRNA and protein expression of the Rac1-GEF Kalirin in a CaMKII-dependent manner. EPS-induced Rac1 activation was lowered by the Kalirin inhibitor ITX3 or siRNA-mediated Kalirin knockdown. KN-93, ITX3, and siRNA-mediated Kalirin knockdown reduced EPS-induced glucose uptake. These findings define a CaMKII-Kalirin-Rac1 signaling pathway that contributes to contraction-stimulated glucose uptake in skeletal muscle myotubes and tissue.
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Affiliation(s)
- Sasa Liu
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Rui Qi
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Juan Zhang
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Chang Zhang
- Department of Pharmacy, General Hospital, Tianjin Medical University, China
| | - Liming Chen
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Zhi Yao
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
| | - Wenyan Niu
- School of Medical Laboratory, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), NHC Key Laboratory of Hormones and Development, Tianjin Medical University, China
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6
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Norman NJ, Ghali J, Radzyukevich TL, Heiny JA, Landero-Figueroa J. Glucose uptake in mammalian cells measured by ICP-MS. Microchem J 2022. [DOI: 10.1016/j.microc.2022.108222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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7
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Draicchio F, Behrends V, Tillin NA, Hurren NM, Sylow L, Mackenzie R. Involvement of the extracellular matrix and integrin signalling proteins in skeletal muscle glucose uptake. J Physiol 2022; 600:4393-4408. [PMID: 36054466 PMCID: PMC9826115 DOI: 10.1113/jp283039] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 08/03/2022] [Indexed: 01/11/2023] Open
Abstract
Whole-body euglycaemia is partly maintained by two cellular processes that encourage glucose uptake in skeletal muscle, the insulin- and contraction-stimulated pathways, with research suggesting convergence between these two processes. The normal structural integrity of the skeletal muscle requires an intact actin cytoskeleton as well as integrin-associated proteins, and thus those structures are likely fundamental for effective glucose uptake in skeletal muscle. In contrast, excessive extracellular matrix (ECM) remodelling and integrin expression in skeletal muscle may contribute to insulin resistance owing to an increased physical barrier causing reduced nutrient and hormonal flux. This review explores the role of the ECM and the actin cytoskeleton in insulin- and contraction-mediated glucose uptake in skeletal muscle. This is a clinically important area of research given that defects in the structural integrity of the ECM and integrin-associated proteins may contribute to loss of muscle function and decreased glucose uptake in type 2 diabetes.
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Affiliation(s)
- Fulvia Draicchio
- School of Life and Health SciencesWhitelands CollegeUniversity of RoehamptonLondonUK
| | - Volker Behrends
- School of Life and Health SciencesWhitelands CollegeUniversity of RoehamptonLondonUK
| | - Neale A. Tillin
- School of Life and Health SciencesWhitelands CollegeUniversity of RoehamptonLondonUK
| | - Nicholas M. Hurren
- School of Life and Health SciencesWhitelands CollegeUniversity of RoehamptonLondonUK
| | - Lykke Sylow
- Molecular Metabolism in Cancer & Ageing Research GroupDepartment of Biomedical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Richard Mackenzie
- School of Life and Health SciencesWhitelands CollegeUniversity of RoehamptonLondonUK
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Møller LLV, Raun SH, Fritzen AM, Sylow L. Measurement of skeletal muscle glucose uptake in mice in response to acute treadmill running. J Biol Methods 2022; 9:e162. [DOI: 10.14440/jbm.2022.385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 03/07/2022] [Accepted: 03/22/2022] [Indexed: 11/23/2022] Open
Abstract
Skeletal muscle contractions stimulate glucose uptake into the working muscles during exercise. Because this signaling pathway is independent of insulin, exercise constitutes an important alternative pathway to increase glucose uptake, also in insulin-resistant muscle. Therefore, much effort is being put into understanding the molecular regulation of exercise-stimulated glucose uptake by skeletal muscle. To delineate the causal molecular mechanisms whereby muscle contraction or exercise regulate glucose uptake, the investigation of genetically manipulated rodents is necessary. Presented here is a modified and optimized protocol assessing exercise-induced muscle glucose uptake in mice in response to acute treadmill running. Using this high-throughput protocol, running capacity can accurately and reproducibly be determined in mice, and basal- and exercise-stimulated skeletal muscle glucose uptake and intracellular signaling can precisely and dose-dependently be measured in awake mice in vivo without the need for catheterization and with minimal loss of blood.
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9
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Liu S, Zhang J, Qi R, Deng B, Ni Y, Zhang C, Niu W. CaMKII and Kalirin, a Rac1-GEF, regulate Akt phosphorylation involved in contraction-induced glucose uptake in skeletal muscle cells. Biochem Biophys Res Commun 2022; 610:170-175. [DOI: 10.1016/j.bbrc.2022.03.152] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 03/28/2022] [Indexed: 12/22/2022]
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10
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Wasserman DH. Insulin, Muscle Glucose Uptake, and Hexokinase: Revisiting the Road Not Taken. Physiology (Bethesda) 2022; 37:115-127. [PMID: 34779282 PMCID: PMC8977147 DOI: 10.1152/physiol.00034.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/05/2021] [Accepted: 11/07/2021] [Indexed: 12/25/2022] Open
Abstract
Research conducted over the last 50 yr has provided insight into the mechanisms by which insulin stimulates glucose transport across the skeletal muscle cell membrane Transport alone, however, does not result in net glucose uptake as free glucose equilibrates across the cell membrane and is not metabolized. Glucose uptake requires that glucose is phosphorylated by hexokinases. Phosphorylated glucose cannot leave the cell and is the substrate for metabolism. It is indisputable that glucose phosphorylation is essential for glucose uptake. Major advances have been made in defining the regulation of the insulin-stimulated glucose transporter (GLUT4) in skeletal muscle. By contrast, the insulin-regulated hexokinase (hexokinase II) parallels Robert Frost's "The Road Not Taken." Here the case is made that an understanding of glucose phosphorylation by hexokinase II is necessary to define the regulation of skeletal muscle glucose uptake in health and insulin resistance. Results of studies from different physiological disciplines that have elegantly described how hexokinase II can be regulated are summarized to provide a framework for potential application to skeletal muscle. Mechanisms by which hexokinase II is regulated in skeletal muscle await rigorous examination.
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Affiliation(s)
- David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
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11
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Raun SH, Knudsen JR, Han X, Jensen TE, Sylow L. Cancer causes dysfunctional insulin signaling and glucose transport in a muscle-type-specific manner. FASEB J 2022; 36:e22211. [PMID: 35195922 DOI: 10.1096/fj.202101759r] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/21/2022] [Accepted: 02/03/2022] [Indexed: 12/14/2022]
Abstract
Metabolic dysfunction and insulin resistance are emerging as hallmarks of cancer and cachexia, and impair cancer prognosis. Yet, the molecular mechanisms underlying impaired metabolic regulation are not fully understood. To elucidate the mechanisms behind cancer-induced insulin resistance in muscle, we isolated extensor digitorum longus (EDL) and soleus muscles from Lewis Lung Carcinoma tumor-bearing mice. Three weeks after tumor inoculation, muscles were isolated and stimulated with or without a submaximal dose of insulin (1.5 nM). Glucose transport was measured using 2-[3 H]Deoxy-Glucose and intramyocellular signaling was investigated using immunoblotting. In soleus muscles from tumor-bearing mice, insulin-stimulated glucose transport was abrogated concomitantly with abolished insulin-induced TBC1D4 and GSK3 phosphorylation. In EDL, glucose transport and TBC1D4 phosphorylation were not impaired in muscles from tumor-bearing mice, while AMPK signaling was elevated. Anabolic insulin signaling via phosphorylation of the mTORC1 targets, p70S6K thr389, and ribosomal-S6 ser235, were decreased by cancer in soleus muscle while increased or unaffected in EDL. In contrast, the mTOR substrate, pULK1 ser757, was reduced in both soleus and EDL by cancer. Hence, cancer causes considerable changes in skeletal muscle insulin signaling that is dependent on muscle-type, which could contribute to metabolic dysregulation in cancer. Thus, the skeletal muscle could be a target for managing metabolic dysfunction in cancer.
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Affiliation(s)
- Steffen H Raun
- Section of Molecular Physiology, Department of nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jonas Roland Knudsen
- Section of Molecular Physiology, Department of nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Xiuqing Han
- Section of Molecular Physiology, Department of nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Lykke Sylow
- Section of Molecular Physiology, Department of nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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Moyle LA, Davoudi S, Gilbert PM. Innovation in culture systems to study muscle complexity. Exp Cell Res 2021; 411:112966. [PMID: 34906582 DOI: 10.1016/j.yexcr.2021.112966] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 10/31/2021] [Accepted: 12/04/2021] [Indexed: 11/19/2022]
Abstract
Endogenous skeletal muscle development, regeneration, and pathology are extremely complex processes, influenced by local and systemic factors. Unpinning how these mechanisms function is crucial for fundamental biology and to develop therapeutic interventions for genetic disorders, but also conditions like sarcopenia and volumetric muscle loss. Ex vivo skeletal muscle models range from two- and three-dimensional primary cultures of satellite stem cell-derived myoblasts grown alone or in co-culture, to single muscle myofibers, myobundles, and whole tissues. Together, these systems provide the opportunity to gain mechanistic insights of stem cell behavior, cell-cell interactions, and mature muscle function in simplified systems, without confounding variables. Here, we highlight recent advances (published in the last 5 years) using in vitro primary cells and ex vivo skeletal muscle models, and summarize the new insights, tools, datasets, and screening methods they have provided. Finally, we highlight the opportunity for exponential advance of skeletal muscle knowledge, with spatiotemporal resolution, that is offered by guiding the study of muscle biology and physiology with in silico modelling and implementing high-content cell biology systems and ex vivo physiology platforms.
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Affiliation(s)
- Louise A Moyle
- Institute of Biomedical Engineering, Toronto, ON, M5S 3G9, Canada; Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON, M5S 3E1, Canada
| | - Sadegh Davoudi
- Institute of Biomedical Engineering, Toronto, ON, M5S 3G9, Canada; Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON, M5S 3E1, Canada
| | - Penney M Gilbert
- Institute of Biomedical Engineering, Toronto, ON, M5S 3G9, Canada; Donnelly Centre for Cellular and Biomolecular Research, Toronto, ON, M5S 3E1, Canada; Department of Cell and Systems Biology, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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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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Interactions between insulin and exercise. Biochem J 2021; 478:3827-3846. [PMID: 34751700 DOI: 10.1042/bcj20210185] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 02/06/2023]
Abstract
The interaction between insulin and exercise is an example of balancing and modifying the effects of two opposing metabolic regulatory forces under varying conditions. While insulin is secreted after food intake and is the primary hormone increasing glucose storage as glycogen and fatty acid storage as triglycerides, exercise is a condition where fuel stores need to be mobilized and oxidized. Thus, during physical activity the fuel storage effects of insulin need to be suppressed. This is done primarily by inhibiting insulin secretion during exercise as well as activating local and systemic fuel mobilizing processes. In contrast, following exercise there is a need for refilling the fuel depots mobilized during exercise, particularly the glycogen stores in muscle. This process is facilitated by an increase in insulin sensitivity of the muscles previously engaged in physical activity which directs glucose to glycogen resynthesis. In physically trained individuals, insulin sensitivity is also higher than in untrained individuals due to adaptations in the vasculature, skeletal muscle and adipose tissue. In this paper, we review the interactions between insulin and exercise during and after exercise, as well as the effects of regular exercise training on insulin action.
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A xanthene derivative, DS20060511, attenuates glucose intolerance by inducing skeletal muscle-specific GLUT4 translocation in mice. Commun Biol 2021; 4:994. [PMID: 34417555 PMCID: PMC8379256 DOI: 10.1038/s42003-021-02491-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 07/21/2021] [Indexed: 12/30/2022] Open
Abstract
Reduced glucose uptake into the skeletal muscle is an important pathophysiological abnormality in type 2 diabetes, and is caused by impaired translocation of glucose transporter 4 (GLUT4) to the skeletal muscle cell surface. Here, we show a xanthene derivative, DS20060511, induces GLUT4 translocation to the skeletal muscle cell surface, thereby stimulating glucose uptake into the tissue. DS20060511 induced GLUT4 translocation and stimulated glucose uptake into differentiated L6-myotubes and into the skeletal muscles in mice. These effects were completely abolished in GLUT4 knockout mice. Induction of GLUT4 translocation by DS20060511 was independent of the insulin signaling pathways including IRS1-Akt-AS160 phosphorylation and IRS1-Rac1-actin polymerization, eNOS pathway, and AMPK pathway. Acute and chronic DS20060511 treatment attenuated the glucose intolerance in obese diabetic mice. Taken together, DS20060511 acts as a skeletal muscle-specific GLUT4 translocation enhancer to facilitate glucose uptake. Further studies of DS20060511 may pave the way for the development of novel antidiabetic medicines.
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Bowman PRT, Smith GL, Gould GW. Run for your life: can exercise be used to effectively target GLUT4 in diabetic cardiac disease? PeerJ 2021; 9:e11485. [PMID: 34113491 PMCID: PMC8162245 DOI: 10.7717/peerj.11485] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 04/27/2021] [Indexed: 12/25/2022] Open
Abstract
The global incidence, associated mortality rates and economic burden of diabetes are now such that it is considered one of the most pressing worldwide public health challenges. Considerable research is now devoted to better understanding the mechanisms underlying the onset and progression of this disease, with an ultimate aim of improving the array of available preventive and therapeutic interventions. One area of particular unmet clinical need is the significantly elevated rate of cardiomyopathy in diabetic patients, which in part contributes to cardiovascular disease being the primary cause of premature death in this population. This review will first consider the role of metabolism and more specifically the insulin sensitive glucose transporter GLUT4 in diabetic cardiac disease, before addressing how we may use exercise to intervene in order to beneficially impact key functional clinical outcomes.
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Affiliation(s)
- Peter R T Bowman
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
| | - Godfrey L Smith
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Gwyn W Gould
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
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Li J, Knudsen JR, Henriquez-Olguin C, Li Z, Birk JB, Persson KW, Hellsten Y, Offergeld A, Jarassier W, Le Grand F, Schjerling P, Wojtaszewski JFP, Jensen TE. AXIN1 knockout does not alter AMPK/mTORC1 regulation and glucose metabolism in mouse skeletal muscle. J Physiol 2021; 599:3081-3100. [PMID: 33913171 DOI: 10.1113/jp281187] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/20/2021] [Indexed: 01/15/2023] Open
Abstract
KEY POINTS Tamoxifen-inducible skeletal muscle-specific AXIN1 knockout (AXIN1 imKO) in mouse does not affect whole-body energy substrate metabolism. AXIN1 imKO does not affect AICAR or insulin-stimulated glucose uptake in adult skeletal muscle. AXIN1 imKO does not affect adult skeletal muscle AMPK or mTORC1 signalling during AICAR/insulin/amino acid incubation, contraction and exercise. During exercise, α2/β2/γ3AMPK and AMP/ATP ratio show greater increases in AXIN1 imKO than wild-type in gastrocnemius muscle. ABSTRACT AXIN1 is a scaffold protein known to interact with >20 proteins in signal transduction pathways regulating cellular development and function. Recently, AXIN1 was proposed to assemble a protein complex essential to catabolic-anabolic transition by coordinating AMPK activation and inactivation of mTORC1 and to regulate glucose uptake-stimulation by both AMPK and insulin. To investigate whether AXIN1 is permissive for adult skeletal muscle function, a phenotypic in vivo and ex vivo characterization of tamoxifen-inducible skeletal muscle-specific AXIN1 knockout (AXIN1 imKO) mice was conducted. AXIN1 imKO did not influence AMPK/mTORC1 signalling or glucose uptake stimulation at rest or in response to different exercise/contraction protocols, pharmacological AMPK activation, insulin or amino acids stimulation. The only genotypic difference observed was in exercising gastrocnemius muscle, where AXIN1 imKO displayed elevated α2/β2/γ3 AMPK activity and AMP/ATP ratio compared to wild-type mice. Our work shows that AXIN1 imKO generally does not affect skeletal muscle AMPK/mTORC1 signalling and glucose metabolism, probably due to functional redundancy of its homologue AXIN2.
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Affiliation(s)
- Jingwen Li
- Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jonas R Knudsen
- Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.,Microsystems Laboratory 2, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Carlos Henriquez-Olguin
- Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Zhencheng Li
- Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jesper B Birk
- Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Kaspar W Persson
- Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Ylva Hellsten
- Section for Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Anika Offergeld
- School of Bioscience, Cardiff University, Cardiff, CF10 3AX, UK
| | - William Jarassier
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U1217, Lyon, 69008, France
| | - Fabien Le Grand
- Institut NeuroMyoGène, Université Claude Bernard Lyon 1, CNRS UMR 5310, INSERM U1217, Lyon, 69008, France
| | - Peter Schjerling
- Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery M, Bispebjerg Hospital, Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E Jensen
- Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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18
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Kang JH, Park JE, Dagoon J, Masson SWC, Merry TL, Bremner SN, Dent JR, Schenk S. Sirtuin 1 is not required for contraction-stimulated glucose uptake in mouse skeletal muscle. J Appl Physiol (1985) 2021; 130:1893-1902. [PMID: 33886385 DOI: 10.1152/japplphysiol.00065.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
While it has long been known that contraction robustly stimulates skeletal muscle glucose uptake, the molecular steps regulating this increase remain incompletely defined. The mammalian ortholog of Sir2, sirtuin 1 (SIRT1), is an NAD+-dependent protein deacetylase that is thought to link perturbations in energy flux associated with exercise to subsequent cellular adaptations. Nevertheless, its role in contraction-stimulated glucose uptake has not been described. The objective of this study was to determine the importance of SIRT1 to contraction-stimulated glucose uptake in mouse skeletal muscle. Using a radioactive 2-deoxyglucose uptake (2DOGU) approach, we measured ex vivo glucose uptake in unstimulated (rested) and electrically stimulated (100 Hz contraction every 15 s for 10 min; contracted) extensor digitorum longus (EDL) and soleus from ∼15-wk-old male and female mice with muscle-specific knockout of SIRT1 deacetylase activity and their wild-type littermates. Skeletal muscle force decreased over the contraction protocol, although there were no differences in the rate of fatigue between genotypes. In EDL and soleus, loss of SIRT1 deacetylase activity did not affect contraction-induced increase in glucose uptake in either sex. Interestingly, the absolute rate of contraction-stimulated 2DOGU was ∼1.4-fold higher in female compared with male mice, regardless of muscle type. Taken together, our findings demonstrate that SIRT1 is not required for contraction-stimulated glucose uptake in mouse skeletal muscle. Moreover, to our knowledge, this is the first demonstration of sex-based differences in contraction-stimulated glucose uptake in mouse skeletal muscle.NEW & NOTEWORTHY Here, we demonstrate that glucose uptake in response to ex vivo contractions is not affected by the loss of sirtuin 1 (SIRT1) deacetylase function in muscle, regardless of sex or muscle type. Interestingly, however, similar to studies on insulin-stimulated glucose uptake, we demonstrate that contraction-stimulated glucose uptake is robustly higher in female compared with the male skeletal muscle. To our knowledge, this is the first demonstration of sex-based differences in contraction-stimulated glucose uptake in skeletal muscle.
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Affiliation(s)
- Ji H Kang
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Ji E Park
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Jason Dagoon
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Stewart W C Masson
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Troy L Merry
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Shannon N Bremner
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California
| | - Jessica R Dent
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California.,Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Simon Schenk
- Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, California.,Biomedical Sciences Graduate Program, University of California, San Diego, La Jolla, California
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19
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Machin PA, Tsonou E, Hornigold DC, Welch HCE. Rho Family GTPases and Rho GEFs in Glucose Homeostasis. Cells 2021; 10:cells10040915. [PMID: 33923452 PMCID: PMC8074089 DOI: 10.3390/cells10040915] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/11/2021] [Accepted: 04/13/2021] [Indexed: 12/17/2022] Open
Abstract
Dysregulation of glucose homeostasis leading to metabolic syndrome and type 2 diabetes is the cause of an increasing world health crisis. New intriguing roles have emerged for Rho family GTPases and their Rho guanine nucleotide exchange factor (GEF) activators in the regulation of glucose homeostasis. This review summates the current knowledge, focusing in particular on the roles of Rho GEFs in the processes of glucose-stimulated insulin secretion by pancreatic β cells and insulin-stimulated glucose uptake into skeletal muscle and adipose tissues. We discuss the ten Rho GEFs that are known so far to regulate glucose homeostasis, nine of which are in mammals, and one is in yeast. Among the mammalian Rho GEFs, P-Rex1, Vav2, Vav3, Tiam1, Kalirin and Plekhg4 were shown to mediate the insulin-stimulated translocation of the glucose transporter GLUT4 to the plasma membrane and/or insulin-stimulated glucose uptake in skeletal muscle or adipose tissue. The Rho GEFs P-Rex1, Vav2, Tiam1 and β-PIX were found to control the glucose-stimulated release of insulin by pancreatic β cells. In vivo studies demonstrated the involvement of the Rho GEFs P-Rex2, Vav2, Vav3 and PDZ-RhoGEF in glucose tolerance and/or insulin sensitivity, with deletion of these GEFs either contributing to the development of metabolic syndrome or protecting from it. This research is in its infancy. Considering that over 80 Rho GEFs exist, it is likely that future research will identify more roles for Rho GEFs in glucose homeostasis.
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Affiliation(s)
- Polly A. Machin
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; (P.A.M.); (E.T.)
| | - Elpida Tsonou
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; (P.A.M.); (E.T.)
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Cambridge CB22 3AT, UK;
| | - David C. Hornigold
- Bioscience Metabolism, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Cambridge CB22 3AT, UK;
| | - Heidi C. E. Welch
- Signalling Programme, The Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK; (P.A.M.); (E.T.)
- Correspondence: ; Tel.: +44-(0)1223-496-596
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20
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Exercise-A Panacea of Metabolic Dysregulation in Cancer: Physiological and Molecular Insights. Int J Mol Sci 2021; 22:ijms22073469. [PMID: 33801684 PMCID: PMC8037630 DOI: 10.3390/ijms22073469] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/21/2021] [Accepted: 03/24/2021] [Indexed: 12/14/2022] Open
Abstract
Metabolic dysfunction is a comorbidity of many types of cancers. Disruption of glucose metabolism is of concern, as it is associated with higher cancer recurrence rates and reduced survival. Current evidence suggests many health benefits from exercise during and after cancer treatment, yet only a limited number of studies have addressed the effect of exercise on cancer-associated disruption of metabolism. In this review, we draw on studies in cells, rodents, and humans to describe the metabolic dysfunctions observed in cancer and the tissues involved. We discuss how the known effects of acute exercise and exercise training observed in healthy subjects could have a positive outcome on mechanisms in people with cancer, namely: insulin resistance, hyperlipidemia, mitochondrial dysfunction, inflammation, and cachexia. Finally, we compile the current limited knowledge of how exercise corrects metabolic control in cancer and identify unanswered questions for future research.
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21
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Abstract
Exercise in humans increases muscle glucose uptake up to 100-fold compared with rest. The magnitude of increase depends on exercise intensity and duration. Although knockout of glucose transporter type 4 (GLUT4) convincingly has shown that GLUT4 is necessary for exercise to increase muscle glucose uptake, studies only show an approximate twofold increase in GLUT4 translocation to the muscle cell membrane when transitioning from rest to exercise. Therefore, there is a big discrepancy between the increase in glucose uptake and GLUT4 translocation. It is suggested that either the methods for measurements of GLUT4 translocation in muscle grossly underestimate the real translocation of GLUT4 or, alternatively, GLUT4 intrinsic activity increases in muscle during exercise, perhaps due to increased muscle temperature and/or mechanical effects during contraction/relaxation cycles.
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Affiliation(s)
- Erik A Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
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22
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De Groote E, Britto FA, Balan E, Warnier G, Thissen JP, Nielens H, Sylow L, Deldicque L. Effect of hypoxic exercise on glucose tolerance in healthy and prediabetic adults. Am J Physiol Endocrinol Metab 2021; 320:E43-E54. [PMID: 33103453 DOI: 10.1152/ajpendo.00263.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This study aimed to investigate the mechanisms known to regulate glucose homeostasis in human skeletal muscle of healthy and prediabetic subjects exercising in normobaric hypoxia. Seventeen healthy (H; 28.8 ± 2.4 yr; maximal oxygen consumption (V̇O2max): 45.1 ± 1.8 mL·kg-1·min-1) and 15 prediabetic (P; 44.6 ± 3.9 yr; V̇O2max: 30.8 ± 2.5 mL·kg-1·min-1) men were randomly assigned to two groups performing an acute exercise bout (heart rate corresponding to 55% V̇O2max) either in normoxic (NE) or in hypoxic (HE; fraction of inspired oxygen [Formula: see text] 14.0%) conditions. An oral glucose tolerance test (OGTT) was performed in a basal state and after an acute exercise bout. Muscle biopsies from m. vastus lateralis were taken before and after exercise. Venous blood samples were taken at regular intervals before, during, and after exercise. The two groups exercising in hypoxia had a larger area under the curve of blood glucose levels during the OGTT after exercise compared with baseline (H: +11%; P: +4%). Compared with pre-exercise, an increase in p-TBC1D1 Ser237 and in p-AMPK Thr172 was observed postexercise in P NE (+95%; +55%, respectively) and H HE (+91%; +43%, respectively). An increase in p-ACC Ser212 was measured after exercise in all groups (H NE: +228%; P NE: +252%; H HE: +252%; P HE: +208%). Our results show that an acute bout of exercise in hypoxia reduces glucose tolerance in healthy and prediabetic subjects. At a molecular level, some adaptations regulating glucose transport in muscle were found in all groups without associations with glucose tolerance after exercise. The results suggest that hypoxia negatively affects glucose tolerance postexercise through unidentified mechanisms.NEW & NOTEWORTHY The molecular mechanisms involved in glucose tolerance after acute exercise in hypoxia have not yet been elucidated in human. Due to the reversible character of their status, prediabetic individuals are of particular interest for preventing the development of type 2 diabetes. The present study is the first to investigate muscle molecular mechanisms during exercise and glucose metabolism after exercise in prediabetic and healthy subjects exercising in normoxia and normobaric hypoxia.
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Affiliation(s)
- Estelle De Groote
- Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Florian A Britto
- Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Estelle Balan
- Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Geoffrey Warnier
- Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Jean-Paul Thissen
- Departement of Diabetology and Nutrition, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Henri Nielens
- Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Lykke Sylow
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Louise Deldicque
- Institute of Neuroscience, Université catholique de Louvain, Louvain-la-Neuve, Belgium
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23
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Shrestha MM, Lim CY, Bi X, Robinson RC, Han W. Tmod3 Phosphorylation Mediates AMPK-Dependent GLUT4 Plasma Membrane Insertion in Myoblasts. Front Endocrinol (Lausanne) 2021; 12:653557. [PMID: 33959097 PMCID: PMC8095187 DOI: 10.3389/fendo.2021.653557] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/22/2021] [Indexed: 12/28/2022] Open
Abstract
Insulin and muscle contractions mediate glucose transporter 4 (GLUT4) translocation and insertion into the plasma membrane (PM) for glucose uptake in skeletal muscles. Muscle contraction results in AMPK activation, which promotes GLUT4 translocation and PM insertion. However, little is known regarding AMPK effectors that directly regulate GLUT4 translocation. We aim to identify novel AMPK effectors in the regulation of GLUT4 translocation. We performed biochemical, molecular biology and fluorescent microscopy imaging experiments using gain- and loss-of-function mutants of tropomodulin 3 (Tmod3). Here we report Tmod3, an actin filament capping protein, as a novel AMPK substrate and an essential mediator of AMPK-dependent GLUT4 translocation and glucose uptake in myoblasts. Furthermore, Tmod3 plays a key role in AMPK-induced F-actin remodeling and GLUT4 insertion into the PM. Our study defines Tmod3 as a key AMPK effector in the regulation of GLUT4 insertion into the PM and glucose uptake in muscle cells, and offers new mechanistic insights into the regulation of glucose homeostasis.
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Affiliation(s)
- Man Mohan Shrestha
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Chun-Yan Lim
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Xuezhi Bi
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Robert C. Robinson
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Weiping Han
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
- *Correspondence: Weiping Han,
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Margaritelis NV, Paschalis V, Theodorou AA, Kyparos A, Nikolaidis MG. Redox basis of exercise physiology. Redox Biol 2020; 35:101499. [PMID: 32192916 PMCID: PMC7284946 DOI: 10.1016/j.redox.2020.101499] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/20/2020] [Accepted: 03/05/2020] [Indexed: 12/15/2022] Open
Abstract
Redox reactions control fundamental processes of human biology. Therefore, it is safe to assume that the responses and adaptations to exercise are, at least in part, mediated by redox reactions. In this review, we are trying to show that redox reactions are the basis of exercise physiology by outlining the redox signaling pathways that regulate four characteristic acute exercise-induced responses (muscle contractile function, glucose uptake, blood flow and bioenergetics) and four chronic exercise-induced adaptations (mitochondrial biogenesis, muscle hypertrophy, angiogenesis and redox homeostasis). Based on our analysis, we argue that redox regulation should be acknowledged as central to exercise physiology.
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Affiliation(s)
- N V Margaritelis
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece; Dialysis Unit, 424 General Military Hospital of Thessaloniki, Thessaloniki, Greece.
| | - V Paschalis
- School of Physical Education and Sport Science, National and Kapodistrian University of Athens, Athens, Greece
| | - A A Theodorou
- Department of Life Sciences, School of Sciences, European University Cyprus, Nicosia, Cyprus
| | - A Kyparos
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - M G Nikolaidis
- Department of Physical Education and Sport Science at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece.
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25
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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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26
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Møller LLV, Nielsen IL, Knudsen JR, Andersen NR, Jensen TE, Sylow L, Richter EA. The p21-activated kinase 2 (PAK2), but not PAK1, regulates contraction-stimulated skeletal muscle glucose transport. Physiol Rep 2020; 8:e14460. [PMID: 32597567 PMCID: PMC7322983 DOI: 10.14814/phy2.14460] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/01/2020] [Accepted: 05/03/2020] [Indexed: 12/18/2022] Open
Abstract
AIM Muscle contraction stimulates skeletal muscle glucose transport. Since it occurs independently of insulin, it is an important alternative pathway to increase glucose transport in insulin-resistant states, but the intracellular signaling mechanisms are not fully understood. Muscle contraction activates group I p21-activated kinases (PAKs) in mouse and human skeletal muscle. PAK1 and PAK2 are downstream targets of Rac1, which is a key regulator of contraction-stimulated glucose transport. Thus, PAK1 and PAK2 could be downstream effectors of Rac1 in contraction-stimulated glucose transport. The current study aimed to test the hypothesis that PAK1 and/or PAK2 regulate contraction-induced glucose transport. METHODS Glucose transport was measured in isolated soleus and extensor digitorum longus (EDL) mouse skeletal muscle incubated either in the presence or absence of a pharmacological inhibitor (IPA-3) of group I PAKs or originating from whole-body PAK1 knockout, muscle-specific PAK2 knockout or double whole-body PAK1 and muscle-specific PAK2 knockout mice. RESULTS IPA-3 attenuated (-22%) the increase in glucose transport in response to electrically stimulated contractions in soleus and EDL muscle. PAK1 was dispensable for contraction-stimulated glucose transport in both soleus and EDL muscle. Lack of PAK2, either alone (-13%) or in combination with PAK1 (-14%), partly reduced contraction-stimulated glucose transport compared to control littermates in EDL, but not soleus muscle. CONCLUSION Contraction-stimulated glucose transport in isolated glycolytic mouse EDL muscle is partly dependent on PAK2, but not PAK1.
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Affiliation(s)
- Lisbeth L. V. Møller
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Ida L. Nielsen
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Jonas R. Knudsen
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Nicoline R. Andersen
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Thomas E. Jensen
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Lykke Sylow
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
| | - Erik A. Richter
- Section of Molecular PhysiologyDepartment of Nutrition, Exercise and SportsFaculty of ScienceUniversity of CopenhagenCopenhagenDenmark
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Ferrari F, Bock PM, Motta MT, Helal L. Biochemical and Molecular Mechanisms of Glucose Uptake Stimulated by Physical Exercise in Insulin Resistance State: Role of Inflammation. Arq Bras Cardiol 2020; 113:1139-1148. [PMID: 31644699 PMCID: PMC7021273 DOI: 10.5935/abc.20190224] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 03/15/2019] [Indexed: 12/12/2022] Open
Abstract
Obesity associated with systemic inflammation induces insulin resistance (IR), with consequent chronic hyperglycemia. A series of reactions are involved in this process, including increased release of proinflammatory cytokines, and activation of c-Jun N-terminal kinase (JNK), nuclear factor-kappa B (NF-κB) and toll-like receptor 4 (TLR4) receptors. Among the therapeutic tools available nowadays, physical exercise (PE) has a known hypoglycemic effect explained by complex molecular mechanisms, including an increase in insulin receptor phosphorylation, in AMP-activated protein kinase (AMPK) activity, in the Ca2+/calmodulin-dependent protein kinase kinase (CaMKK) pathway, with subsequent activation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), Rac1, TBC1 domain family member 1 and 4 (TBC1D1 and TBC1D4), in addition to a variety of signaling molecules, such as GTPases, Rab and soluble N-ethylmaleimide-sensitive factor attached protein receptor (SNARE) proteins. These pathways promote greater translocation of GLUT4 and consequent glucose uptake by the skeletal muscle. Phosphoinositide-dependent kinase (PDK), atypical protein kinase C (aPKC) and some of its isoforms, such as PKC-iota/lambda also seem to play a fundamental role in the transport of glucose. In this sense, the association between autophagy and exercise has also demonstrated a relevant role in the uptake of muscle glucose. Insulin, in turn, uses a phosphoinositide 3-kinase (PI3K)-dependent mechanism, while exercise signal may be triggered by the release of calcium from the sarcoplasmic reticulum. The objective of this review is to describe the main molecular mechanisms of IR and the relationship between PE and glucose uptake.
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Affiliation(s)
- Filipe Ferrari
- Programa de Pós-graduação em Cardiologia e Ciências Cardiovasculares - Faculdade de Medicina - Hospital de Clínicas de Porto Alegre (HCPA) - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS - Brazil.,Grupo de Pesquisa em Cardiologia do Exercício - CardioEx (HCPA/UFRGS), Porto Alegre, RS - Brazil
| | - Patrícia Martins Bock
- Laboratório de Fisiopatologia do Exercício (LaFiEx), (HCPA/UFRGS), Porto Alegre, RS - Brazil.,Instituto de Avaliação de Tecnologias em Saúde (IATS), Hospital de Clínicas de Porto Alegre, Porto Alegre, RS - Brazil.,Faculdades Integradas de Taquara, Taquara, RS - Brazil
| | - Marcelo Trotte Motta
- Departamento de Ciências Biológicas, Universidade Estadual de Feira de Santana (UEFS), Feira de Santana, BA - Brazil
| | - Lucas Helal
- Programa de Pós-graduação em Cardiologia e Ciências Cardiovasculares - Faculdade de Medicina - Hospital de Clínicas de Porto Alegre (HCPA) - Universidade Federal do Rio Grande do Sul, Porto Alegre, RS - Brazil.,Laboratório de Fisiopatologia do Exercício (LaFiEx), (HCPA/UFRGS), Porto Alegre, RS - Brazil
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28
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Yue Y, Zhang C, Zhang X, Zhang S, Liu Q, Hu F, Lv X, Li H, Yang J, Wang X, Chen L, Yao Z, Duan H, Niu W. An AMPK/Axin1-Rac1 signaling pathway mediates contraction-regulated glucose uptake in skeletal muscle cells. Am J Physiol Endocrinol Metab 2020; 318:E330-E342. [PMID: 31846370 DOI: 10.1152/ajpendo.00272.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Contraction stimulates skeletal muscle glucose uptake predominantly through activation of AMP-activated protein kinase (AMPK) and Rac1. However, the molecular details of how contraction activates these signaling proteins are not clear. Recently, Axin1 has been shown to form a complex with AMPK and liver kinase B1 during glucose starvation-dependent activation of AMPK. Here, we demonstrate that electrical pulse-stimulated (EPS) contraction of C2C12 myotubes or treadmill exercise of C57BL/6 mice enhanced reciprocal coimmunoprecipitation of Axin1 and AMPK from myotube lysates or gastrocnemius muscle tissue. Interestingly, EPS or exercise upregulated total cellular Axin1 levels in an AMPK-dependent manner in C2C12 myotubes and gastrocnemius mouse muscle, respectively. Also, direct activation of AMPK with 5-aminoimidazole-4-carboxamide ribonucleotide treatment of C2C12 myotubes or gastrocnemius muscle elevated Axin1 protein levels. On the other hand, siRNA-mediated Axin1 knockdown lessened activation of AMPK in contracted myotubes. Further, AMPK inhibition with compound C or siRNA-mediated knockdown of AMPK or Axin1 blocked contraction-induced GTP loading of Rac1, p21-activated kinase phosphorylation, and contraction-stimulated glucose uptake. In summary, our results suggest that an AMPK/Axin1-Rac1 signaling pathway mediates contraction-stimulated skeletal muscle glucose uptake.
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Affiliation(s)
- Yingying Yue
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Chang Zhang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
- School of Pharmacy, Research Center of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Xuejiao Zhang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Shitian Zhang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Qian Liu
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Fang Hu
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Xiaoting Lv
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Hanqi Li
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Jianming Yang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Xinli Wang
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Liming Chen
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Zhi Yao
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Hongquan Duan
- School of Pharmacy, Research Center of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Wenyan Niu
- Department of Immunology, Key Laboratory of Immune Microenvironment and Disease, Ministry of Education, Tianjin Medical University, Tianjin, China
- NHC Key Laboratory of Hormones and Development, Tianjin Medical University, Tianjin, China
- Tianjin Key Laboratory of Metabolic Diseases, Tianjin Medical University Chu Hsien-I Memorial Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
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29
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Henríquez-Olguín C, Boronat S, Cabello-Verrugio C, Jaimovich E, Hidalgo E, Jensen TE. The Emerging Roles of Nicotinamide Adenine Dinucleotide Phosphate Oxidase 2 in Skeletal Muscle Redox Signaling and Metabolism. Antioxid Redox Signal 2019; 31:1371-1410. [PMID: 31588777 PMCID: PMC6859696 DOI: 10.1089/ars.2018.7678] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Significance: Skeletal muscle is a crucial tissue to whole-body locomotion and metabolic health. Reactive oxygen species (ROS) have emerged as intracellular messengers participating in both physiological and pathological adaptations in skeletal muscle. A complex interplay between ROS-producing enzymes and antioxidant networks exists in different subcellular compartments of mature skeletal muscle. Recent evidence suggests that nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) are a major source of contraction- and insulin-stimulated oxidants production, but they may paradoxically also contribute to muscle insulin resistance and atrophy. Recent Advances: Pharmacological and molecular biological tools, including redox-sensitive probes and transgenic mouse models, have generated novel insights into compartmentalized redox signaling and suggested that NOX2 contributes to redox control of skeletal muscle metabolism. Critical Issues: Major outstanding questions in skeletal muscle include where NOX2 activation occurs under different conditions in health and disease, how NOX2 activation is regulated, how superoxide/hydrogen peroxide generated by NOX2 reaches the cytosol, what the signaling mediators are downstream of NOX2, and the role of NOX2 for different physiological and pathophysiological processes. Future Directions: Future research should utilize and expand the current redox-signaling toolbox to clarify the NOX2-dependent mechanisms in skeletal muscle and determine whether the proposed functions of NOX2 in cells and animal models are conserved into humans.
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Affiliation(s)
- Carlos Henríquez-Olguín
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports (NEXS), Faculty of Science, University of Copenhagen, Copenhagen, Denmark.,Muscle Cell Physiology Laboratory, Center for Exercise, Metabolism, and Cancer, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Susanna Boronat
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Claudio Cabello-Verrugio
- Laboratory of Muscle Pathology, Fragility and Aging, Department of Biological Sciences, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy, Santiago, Chile.,Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago, Chile
| | - Enrique Jaimovich
- Muscle Cell Physiology Laboratory, Center for Exercise, Metabolism, and Cancer, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports (NEXS), Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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30
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Nelson ME, Parker BL, Burchfield JG, Hoffman NJ, Needham EJ, Cooke KC, Naim T, Sylow L, Ling NXY, Francis D, Norris DM, Chaudhuri R, Oakhill JS, Richter EA, Lynch GS, Stöckli J, James DE. Phosphoproteomics reveals conserved exercise-stimulated signaling and AMPK regulation of store-operated calcium entry. EMBO J 2019; 38:e102578. [PMID: 31381180 PMCID: PMC6912027 DOI: 10.15252/embj.2019102578] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/27/2019] [Accepted: 07/01/2019] [Indexed: 12/20/2022] Open
Abstract
Exercise stimulates cellular and physiological adaptations that are associated with widespread health benefits. To uncover conserved protein phosphorylation events underlying this adaptive response, we performed mass spectrometry-based phosphoproteomic analyses of skeletal muscle from two widely used rodent models: treadmill running in mice and in situ muscle contraction in rats. We overlaid these phosphoproteomic signatures with cycling in humans to identify common cross-species phosphosite responses, as well as unique model-specific regulation. We identified > 22,000 phosphosites, revealing orthologous protein phosphorylation and overlapping signaling pathways regulated by exercise. This included two conserved phosphosites on stromal interaction molecule 1 (STIM1), which we validate as AMPK substrates. Furthermore, we demonstrate that AMPK-mediated phosphorylation of STIM1 negatively regulates store-operated calcium entry, and this is beneficial for exercise in Drosophila. This integrated cross-species resource of exercise-regulated signaling in human, mouse, and rat skeletal muscle has uncovered conserved networks and unraveled crosstalk between AMPK and intracellular calcium flux.
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Affiliation(s)
- Marin E Nelson
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Benjamin L Parker
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
- Present address:
Department of PhysiologyThe University of MelbourneMelbourneVic.Australia
| | - James G Burchfield
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Nolan J Hoffman
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
- Present address:
Exercise and Nutrition Research ProgramMary MacKillop Institute for Health ResearchAustralian Catholic UniversityMelbourneVic.Australia
| | - Elise J Needham
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Kristen C Cooke
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Timur Naim
- Centre for Muscle ResearchDepartment of PhysiologySchool of Biomedical SciencesThe University of MelbourneMelbourneVicAustralia
| | - Lykke Sylow
- Department of Nutrition, Exercise and SportsFaculty of ScienceThe University of CopenhagenCopenhagenDenmark
| | - Naomi XY Ling
- Metabolic Signalling LaboratorySt. Vincent's Institute of Medical ResearchMelbourneVic.Australia
| | - Deanne Francis
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Dougall M Norris
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Rima Chaudhuri
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - Jonathan S Oakhill
- Metabolic Signalling LaboratorySt. Vincent's Institute of Medical ResearchMelbourneVic.Australia
- Exercise and Nutrition Research ProgramMary MacKillop Institute for Health ResearchAustralian Catholic UniversityMelbourneVic.Australia
| | - Erik A Richter
- Department of Nutrition, Exercise and SportsFaculty of ScienceThe University of CopenhagenCopenhagenDenmark
| | - Gordon S Lynch
- Centre for Muscle ResearchDepartment of PhysiologySchool of Biomedical SciencesThe University of MelbourneMelbourneVicAustralia
| | - Jacqueline Stöckli
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
| | - David E James
- Charles Perkins CentreSchool of Life and Environmental SciencesSydney Medical SchoolThe University of SydneySydneyNSWAustralia
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31
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Weighted Gene Coexpression Network Analysis Identified MicroRNA Coexpression Modules and Related Pathways in Type 2 Diabetes Mellitus. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:9567641. [PMID: 31915515 PMCID: PMC6935443 DOI: 10.1155/2019/9567641] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 11/04/2019] [Accepted: 11/11/2019] [Indexed: 12/31/2022]
Abstract
Objective Type 2 diabetes mellitus (T2DM) is a metabolic disease with high incidence, which has seriously affected human life and health. MicroRNA, a short-chain noncoding RNA, plays an important role in T2DM. Identification of meaningful microRNA modules and the role of microRNAs provide a basis for searching potential biomarkers of T2DM. Materials and Methods In this study, three newly diagnosed patients with T2DM and three controls were selected for Whole Peripheral Blood RNA Sequencing to establish a microRNA library. Weighted gene coexpression network analysis (WGCNA) was applied to construct coexpression modules and to detect the trait-related microRNA modules; then, KEGG enrichment analysis was performed to predict the biological function of the interest modules, and candidate hub microRNAs were screened out by the value of module membership (MM) and protein-protein interaction (PPI) network. Result Four microRNA modules (blue, brown, magenta, and turquoise) were highly associated with the T2DM; the number of miRNAs in these modules ranged from 41 to 469. The Fc gamma R-mediated phagocytosis pathway, Rap1 signaling pathway, MAPK signaling pathway, and Lysosome pathway were common pathways in three of the four modules. RPS27A, UBC, and RAC1 were the top three proteins in our study; their corresponding RNAs were miR-1271-5p, miR-130a-3p, miR-130b-3p, and miR-574-3p. Conclusion In summary, this study identified blood miRNAs in human T2DM using RNA sequencing. The findings may be the foundation for understanding the potential role of miRNAs in T2DM.
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32
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Sylow L, Richter EA. Current advances in our understanding of exercise as medicine in metabolic disease. CURRENT OPINION IN PHYSIOLOGY 2019. [DOI: 10.1016/j.cophys.2019.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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33
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Henríquez-Olguin C, Knudsen JR, Raun SH, Li Z, Dalbram E, Treebak JT, Sylow L, Holmdahl R, Richter EA, Jaimovich E, Jensen TE. Cytosolic ROS production by NADPH oxidase 2 regulates muscle glucose uptake during exercise. Nat Commun 2019; 10:4623. [PMID: 31604916 PMCID: PMC6789013 DOI: 10.1038/s41467-019-12523-9] [Citation(s) in RCA: 115] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 09/11/2019] [Indexed: 12/11/2022] Open
Abstract
Reactive oxygen species (ROS) act as intracellular compartmentalized second messengers, mediating metabolic stress-adaptation. In skeletal muscle fibers, ROS have been suggested to stimulate glucose transporter 4 (GLUT4)-dependent glucose transport during artificially evoked contraction ex vivo, but whether myocellular ROS production is stimulated by in vivo exercise to control metabolism is unclear. Here, we combined exercise in humans and mice with fluorescent dyes, genetically-encoded biosensors, and NADPH oxidase 2 (NOX2) loss-of-function models to demonstrate that NOX2 is the main source of cytosolic ROS during moderate-intensity exercise in skeletal muscle. Furthermore, two NOX2 loss-of-function mouse models lacking either p47phox or Rac1 presented striking phenotypic similarities, including greatly reduced exercise-stimulated glucose uptake and GLUT4 translocation. These findings indicate that NOX2 is a major myocellular ROS source, regulating glucose transport capacity during moderate-intensity exercise.
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Affiliation(s)
- Carlos Henríquez-Olguin
- Department of Nutrition, Exercise and Sports, Section of Molecular Physiology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark.,Center for Exercise, Metabolism and Cancer, ICBM, Universidad de Chile, 8380453, Santiago, Chile
| | - Jonas R Knudsen
- Department of Nutrition, Exercise and Sports, Section of Molecular Physiology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark
| | - Steffen H Raun
- Department of Nutrition, Exercise and Sports, Section of Molecular Physiology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark
| | - Zhencheng Li
- Department of Nutrition, Exercise and Sports, Section of Molecular Physiology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark
| | - Emilie Dalbram
- Novo Nordisk Foundation Center for Basic Metabolic Research, Integrative Metabolism and Environmental Influence, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3A, 2200, Copenhagen, Denmark
| | - Jonas T Treebak
- Novo Nordisk Foundation Center for Basic Metabolic Research, Integrative Metabolism and Environmental Influence, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3A, 2200, Copenhagen, Denmark
| | - Lykke Sylow
- Department of Nutrition, Exercise and Sports, Section of Molecular Physiology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark
| | - Rikard Holmdahl
- Section for Medical Inflammation Research, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Solnavägen 9, 171 65, Solna, Sweden
| | - Erik A Richter
- Department of Nutrition, Exercise and Sports, Section of Molecular Physiology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark
| | - Enrique Jaimovich
- Center for Exercise, Metabolism and Cancer, ICBM, Universidad de Chile, 8380453, Santiago, Chile
| | - Thomas E Jensen
- Department of Nutrition, Exercise and Sports, Section of Molecular Physiology, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark.
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34
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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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35
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Abstract
A pivotal metabolic function of insulin is the stimulation of glucose uptake into muscle and adipose tissues. The discovery of the insulin-responsive glucose transporter type 4 (GLUT4) protein in 1988 inspired its molecular cloning in the following year. It also spurred numerous cellular mechanistic studies laying the foundations for how insulin regulates glucose uptake by muscle and fat cells. Here, we reflect on the importance of the GLUT4 discovery and chronicle additional key findings made in the past 30 years. That exocytosis of a multispanning membrane protein regulates cellular glucose transport illuminated a novel adaptation of the secretory pathway, which is to transiently modulate the protein composition of the cellular plasma membrane. GLUT4 controls glucose transport into fat and muscle tissues in response to insulin and also into muscle during exercise. Thus, investigation of regulated GLUT4 trafficking provides a major means by which to map the essential signaling components that transmit the effects of insulin and exercise. Manipulation of the expression of GLUT4 or GLUT4-regulating molecules in mice has revealed the impact of glucose uptake on whole-body metabolism. Remaining gaps in our understanding of GLUT4 function and regulation are highlighted here, along with opportunities for future discoveries and for the development of therapeutic approaches to manage metabolic disease.
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Affiliation(s)
- Amira Klip
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Timothy E McGraw
- Department of Biochemistry, Weill Medical College of Cornell University, New York, New York 10065
| | - David E James
- Charles Perkins Centre, School of Life and Environmental Sciences, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2050, Australia
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36
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Henríquez-Olguín C, Renani LB, Arab-Ceschia L, Raun SH, Bhatia A, Li Z, Knudsen JR, Holmdahl R, Jensen TE. Adaptations to high-intensity interval training in skeletal muscle require NADPH oxidase 2. Redox Biol 2019; 24:101188. [PMID: 30959461 PMCID: PMC6454063 DOI: 10.1016/j.redox.2019.101188] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 03/11/2019] [Accepted: 03/30/2019] [Indexed: 01/12/2023] Open
Abstract
OBJECTIVE Reactive oxygen species (ROS) have been proposed as signaling molecules mediating exercise training adaptation, but the ROS source has remained unclear. This study aimed to investigate if increased NADPH oxidase (NOX)2-dependent activity during exercise is required for long-term high-intensity interval training (HIIT) in skeletal muscle using a mouse model lacking functional NOX2 complex due to absent p47phox (Ncf1) subunit expression (ncf1* mutation). METHODS HIIT was investigated after an acute bout of exercise and after a chronic intervention (3x/week for 6 weeks) in wild-type (WT) vs. NOX2 activity-deficient (ncf1*) mice. NOX2 activation during HIIT was measured using an electroporated genetically-encoded biosensor. Immunoblotting and single-fiber microscopy was performed to measure classical exercise-training responsive endpoints in skeletal muscle. RESULTS A single bout of HIIT increased NOX2 activity measured as p47-roGFP oxidation immediately after exercise but not 1 h or 4 h after exercise. After a 6-week HIIT regimen, improvements in maximal running capacity and some muscle training-markers responded less to HIIT in the ncf1* mice compared to WT, including superoxide dismutase 2, catalase, hexokinase II, pyruvate dehydrogenase and protein markers of mitochondrial oxidative phosphorylation complexes. Strikingly, HIIT-training increased mitochondrial network area and decreased fragmentation in WT mice only. CONCLUSION This study suggests that HIIT exercise increases NOX2 activity in skeletal muscle and shows that NOX2 activity is required for specific skeletal muscle adaptations to HIIT relating to antioxidant defense, glucose metabolism, and mitochondria.
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Affiliation(s)
- Carlos Henríquez-Olguín
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Leila Baghersad Renani
- Faculty of Physical Education and Sports Sciences, University of Tehran, Tehran, Islamic Republic of Iran
| | - Lyne Arab-Ceschia
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Steffen H Raun
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Aakash Bhatia
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Zhencheng Li
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Jonas R Knudsen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Rikard Holmdahl
- Section for Medical Inflammation Research, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark.
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Møller LLV, Klip A, Sylow L. Rho GTPases-Emerging Regulators of Glucose Homeostasis and Metabolic Health. Cells 2019; 8:E434. [PMID: 31075957 PMCID: PMC6562660 DOI: 10.3390/cells8050434] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 05/02/2019] [Accepted: 05/06/2019] [Indexed: 12/11/2022] Open
Abstract
Rho guanosine triphosphatases (GTPases) are key regulators in a number of cellular functions, including actin cytoskeleton remodeling and vesicle traffic. Traditionally, Rho GTPases are studied because of their function in cell migration and cancer, while their roles in metabolism are less documented. However, emerging evidence implicates Rho GTPases as regulators of processes of crucial importance for maintaining metabolic homeostasis. Thus, the time is now ripe for reviewing Rho GTPases in the context of metabolic health. Rho GTPase-mediated key processes include the release of insulin from pancreatic β cells, glucose uptake into skeletal muscle and adipose tissue, and muscle mass regulation. Through the current review, we cast light on the important roles of Rho GTPases in skeletal muscle, adipose tissue, and the pancreas and discuss the proposed mechanisms by which Rho GTPases act to regulate glucose metabolism in health and disease. We also describe challenges and goals for future research.
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Affiliation(s)
- Lisbeth Liliendal Valbjørn Møller
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100 Copenhagen Oe, Denmark.
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 0A4, Canada.
| | - Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100 Copenhagen Oe, Denmark.
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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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Muo IM, MacDonald SD, Madan R, Park SJ, Gharib AM, Martinez PE, Walter MF, Yang SB, Rodante JA, Courville AB, Walter PJ, Cai H, Glicksman M, Guerrieri GM, Ben-Dor RR, Ouwerkerk R, Mao S, Chung JH. Early effects of roflumilast on insulin sensitivity in adults with prediabetes and overweight/obesity involve age-associated fat mass loss - results of an exploratory study. Diabetes Metab Syndr Obes 2019; 12:743-759. [PMID: 31213865 PMCID: PMC6542328 DOI: 10.2147/dmso.s182953] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Roflumilast (Daliresp, Daxas) is a FDA-approved phosphodiesterase 4 (PDE4) inhibitor for the treatment of moderate-to-severe chronic obstructive pulmonary disease. In mice and in limited human studies, this oral medication can cause weight loss and improve insulin sensitivity. We set out to determine the mechanism of its effect on insulin sensitivity. PATIENTS AND METHODS Eight adults with overweight/obesity and prediabetes received roflumilast for 6 weeks. Before and after roflumilast, subjects underwent tests of insulin sensitivity, mixed meal test, body composition, markers of inflammation, and mitochondria function. Dietary intake and physical activity were also assessed. Our primary outcome was the change in peripheral insulin sensitivity, as assessed by the hyper-insulinemic euglycemic clamp. RESULTS This study was underpowered for the primary outcome. Pre- and post-roflumilast mean peripheral insulin sensitivity were 48.7 and 70.0 mg/g fat free mass/minute, respectively, (P-value=0.18), respectively. Among the mixed meal variables, roflumilast altered glucagon-like peptide 1 (GLP-1) hormone the most, although the average effect was not statistically significant (P=0.18). Roflumilast induced a trend toward significance in 1) decreased energy intake (from 11,095 KJ to 8,4555 KJ, P=0.07), 2) decreased fat mass (from 34.53 to 32.97 kg, P=0.06), 3) decreased total and LDL cholesterol (P=0.06 for both variables), and 4) increased plasma free fatty acids (from 0.40 to 0.50 mEq/L, P=0.09) The interval changes in adiposity and free fatty acid were significantly associated with the subject's age (P-value range= <0.001 to 0.02 for the correlations). Inflammatory and adhesion markers, though unchanged, significantly correlated with one another and with incretin hormones only after roflumilast. CONCLUSION We demonstrate, for the first time in humans, increasing percentage of fat mass loss from roflumilast with increasing age in adults with prediabetes and overweight/obesity. We also demonstrate novel associations among roflumilast-induced changes in incretin hormones, inflammatory markers, peripheral insulin sensitivity, and adiposity. We conclude that roflumilast's early effects on insulin sensitivity is indirect and likely mediated through roflumilast's prioritization of lipid over glucose handling. CLINICAL TRIALS REGISTRATION NCT01862029.
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Affiliation(s)
- Ijeoma M Muo
- Laboratory of Obesity and Aging Research NHLBI, National Institutes of Health, Bethesda, MD 20892, USA, ,
| | - Sandra D MacDonald
- NHLBI Pulmonary Branch, Laboratory of Chronic Airway Infections, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ritu Madan
- Diabetes Endocrinology and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sung-Jun Park
- Laboratory of Obesity and Aging Research NHLBI, National Institutes of Health, Bethesda, MD 20892, USA, ,
| | - Ahmed M Gharib
- Biomedical and Metabolic Imaging Branch NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Pedro E Martinez
- Section on Behavioral Endocrinology, NIMH, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mary F Walter
- Diabetes Endocrinology and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shanna B Yang
- Clinical Center Nutrition Department, National Institutes of Health, Bethesda, MD 20892, USA
| | - Justin A Rodante
- Laboratory of Inflammation and Cardiometabolic Diseases, NHLBI, National Institutes of Health, Bethesda, MD 20892, USA
| | - Amber B Courville
- Clinical Center Nutrition Department, National Institutes of Health, Bethesda, MD 20892, USA
| | - Peter J Walter
- Mass Spectrometry Clinical Core, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hongyi Cai
- Mass Spectrometry Clinical Core, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael Glicksman
- Diabetes Endocrinology and Obesity Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gioia M Guerrieri
- Section on Behavioral Endocrinology, NIMH, National Institutes of Health, Bethesda, MD 20892, USA
| | - Rivka R Ben-Dor
- NIMH, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ronald Ouwerkerk
- Biomedical and Metabolic Imaging Branch NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Stephanie Mao
- Laboratory of Obesity and Aging Research NHLBI, National Institutes of Health, Bethesda, MD 20892, USA, ,
| | - Jay H Chung
- Laboratory of Obesity and Aging Research NHLBI, National Institutes of Health, Bethesda, MD 20892, USA, ,
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Kerris JP, Betik AC, Li J, McConell GK. Passive stretch regulates skeletal muscle glucose uptake independent of nitric oxide synthase. J Appl Physiol (1985) 2018; 126:239-245. [PMID: 30236052 DOI: 10.1152/japplphysiol.00368.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Skeletal muscle contraction increases glucose uptake via an insulin-independent mechanism. Signaling pathways arising from mechanical strain are activated during muscle contractions, and mechanical strain in the form of passive stretching stimulates glucose uptake. However, the exact mechanisms regulating stretch-stimulated glucose uptake are not known. Since nitric oxide synthase (NOS) has been implicated in the regulation of glucose uptake during ex vivo and in situ muscle contractions and during exercise, and NO is increased with stretch, we examined whether the increase in muscle glucose uptake during stretching involves NOS. We passively stretched isolated extensor digitorum longus muscles (15 min at ~100-130 mN) from control mice and mice lacking either neuronal NOSµ (nNOSµ) or endothelial NOS (eNOS) isoforms, as well as used pharmacological inhibitors of NOS. Stretch significantly increased muscle glucose uptake appoximately twofold ( P < 0.05), and this was unaffected by the presence of the NOS inhibitors NG-monomethyl-l-arginine (100 µM) or NG-nitro-l-arginine methyl ester (100 µM). Similarly, stretch-stimulated glucose uptake was not attenuated by deletion of either eNOS or nNOSµ isoforms. Furthermore, stretching failed to increase skeletal muscle NOS enzymatic activity above resting levels. These data clearly demonstrate that stretch-stimulated skeletal muscle glucose uptake is not dependent on NOS. NEW & NOTEWORTHY Passive stretching is known to activate muscle glucose uptake through mechanisms that partially overlap with contraction. We report that genetic knockout of endothelial nitric oxide synthase (NOS) or neuronal NOS or pharmacological NOS inhibition does not affect stretch-stimulated glucose uptake. Passive stretch failed to increase NOS activity above resting levels. This information is important for the study of signaling pathways that regulate stretch-stimulated glucose uptake and indicate that NOS should be excluded as a potential signaling factor in this regard.
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Affiliation(s)
- Jarrod P Kerris
- Institute for Health and Sport, Victoria University , Melbourne , Australia.,College of Sport and Exercise Science, Victoria University , Melbourne , Australia
| | - Andrew C Betik
- Institute for Health and Sport, Victoria University , Melbourne , Australia.,College of Health and Biomedicine, Victoria University , Melbourne , Australia
| | - Jinhua Li
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University , Clayton , Australia
| | - Glenn K McConell
- Institute for Health and Sport, Victoria University , Melbourne , Australia.,College of Sport and Exercise Science, Victoria University , Melbourne , Australia
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The Small Yeast GTPase Rho5 and Its Dimeric GEF Dck1/Lmo1 Respond to Glucose Starvation. Int J Mol Sci 2018; 19:ijms19082186. [PMID: 30049968 PMCID: PMC6121567 DOI: 10.3390/ijms19082186] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 07/21/2018] [Accepted: 07/23/2018] [Indexed: 12/25/2022] Open
Abstract
Rho5 is a small GTPase of Saccharomyces cerevisiae and a homolog of mammalian Rac1. The latter regulates glucose metabolism and actin cytoskeleton dynamics, and its misregulation causes cancer and a variety of other diseases. In yeast, Rho5 has been implicated in different signal transduction pathways, governing cell wall integrity and the responses to high medium osmolarity and oxidative stress. It has also been proposed to affect mitophagy and apoptosis. Here, we demonstrate that Rho5 rapidly relocates from the plasma membrane to mitochondria upon glucose starvation, mediated by its dimeric GDP/GTP exchange factor (GEF) Dck1/Lmo1. A function in response to glucose availability is also suggested by synthetic genetic phenotypes of a rho5 deletion with gpr1, gpa2, and sch9 null mutants. On the other hand, the role of mammalian Rac1 in regulating the action cytoskeleton does not seem to be strongly conserved in S. cerevisiae Rho5. We propose that Rho5 serves as a central hub in integrating various stress conditions, including a crosstalk with the cAMP/PKA (cyclic AMP activating protein kinase A) and Sch9 branches of glucose signaling pathways.
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42
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Kleinert M, Parker BL, Jensen TE, Raun SH, Pham P, Han X, James DE, Richter EA, Sylow L. Quantitative proteomic characterization of cellular pathways associated with altered insulin sensitivity in skeletal muscle following high-fat diet feeding and exercise training. Sci Rep 2018; 8:10723. [PMID: 30013070 PMCID: PMC6048112 DOI: 10.1038/s41598-018-28540-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/21/2018] [Indexed: 01/26/2023] Open
Abstract
Regular exercise elicits advantageous metabolic adaptations in skeletal muscle, such as improved insulin sensitivity. However, the underpinning molecular mechanisms and the effect of diet on muscle exercise training benefits are unclear. We therefore characterized the skeletal muscle proteome following exercise training (ET) in mice fed chow or high-fat diet (HFD). ET increased exercise performance, lowered body-weight, decreased fat mass and improved muscle insulin action in chow- and HFD-fed mice. At the molecular level, ET regulated 170 muscle proteins in chow-fed mice, but only 29 proteins in HFD-fed mice. HFD per se altered 56 proteins, most of which were regulated in a similar direction by ET. To identify proteins that might have particular health-related bearing on skeletal muscle metabolism, we filtered for differentially regulated proteins in response to ET and HFD. This yielded 15 proteins, including the major urinary protein 1 (MUP1), which was the protein most decreased after HFD, but increased with ET. The ET-induced Mup1 expression was absent in mouse muscle lacking functional AMPK. MUP1 also potentiated insulin-stimulated GLUT4 translocation in cultured muscle cells. Collectively, we provide a resource of ET-regulated proteins in insulin-sensitive and insulin-resistant skeletal muscle. The identification of MUP1 as a diet-, ET- and AMPK-regulated skeletal muscle protein that improves insulin sensitivity in muscle cells demonstrates the usefulness of these data.
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Affiliation(s)
- Maximilian Kleinert
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.,Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764, Neuherberg, Germany.,Division of Metabolic Diseases, Department of Medicine, Technische Universität München, 80333, Munich, Germany.,German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Benjamin L Parker
- The University of Sydney, Charles Perkins Centre, School of Life and Environmental Sciences, Sydney, Australia
| | - Thomas E Jensen
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Steffen H Raun
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Phung Pham
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), 85764, Neuherberg, Germany
| | - Xiuqing Han
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - David E James
- The University of Sydney, Charles Perkins Centre, School of Life and Environmental Sciences, Sydney, Australia
| | - Erik A Richter
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
| | - Lykke Sylow
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
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43
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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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