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Thomas E, Ficarra S, Nakamura M, Drid P, Trivic T, Bianco A. The Effects of Stretching Exercise on Levels of Blood Glucose: A Systematic Review with Meta-Analysis. SPORTS MEDICINE - OPEN 2024; 10:15. [PMID: 38334888 PMCID: PMC10858005 DOI: 10.1186/s40798-023-00661-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 11/17/2023] [Indexed: 02/10/2024]
Abstract
BACKGROUND Physical activity plays an important role in the management of blood glucose levels. However, compelling evidence exists only for aerobic and resistance training. In this review, we aimed to identify the potential effects of stretching exercises on blood glucose levels. METHODS A systematic literature search was performed using the following databases: Scopus, NLM PubMed, and Web of Science. Studies regarding the effects of stretching exercise in humans on blood glucose or any related variable were included. Further inclusion criteria were: (1) original articles (published from database inception to October 2022), (2) applying stretching as a unique exercise modality, (3) having either longitudinal or acute interventions, (4) including healthy and pathological populations, and (5) having within each study a pre- and post-intervention measure. Quality assessment of the studies was conducted using the Downs and Black checklist. RESULTS A total of 13 articles were included. The quality assessment revealed an overall moderate quality of the included records. Ten articles included patients with type 2 diabetes (T2D), whereas the remaining three included at-risk populations. A total of 731 people with a mean age of 56.7 ± 6.1 years old were analysed. Fasting blood glucose, 2 h post-oral glucose uptake, post-stretching intervention blood glucose levels, and HbA1c were identified as variables related to blood glucose within the studies. After the stretching interventions, a significant reduction was observed in either blood glucose (ES = - 0.79; p = 0.0174) or HbA1c (ES = - 1.11; p = < 0.0001). Meta-analytic results highlighted greater effects in T2D patients (ES = - 1.15; p = 0.02) and for studies applying stretching as an exercise intervention (ES = - 1.27; p = 0.006) rather than considering stretching as a control exercise modality. CONCLUSION The results of this systematic review highlight the potential of stretching exercises to reduce blood glucose levels. In particular, if stretching is applied as a specific form of exercise intervention in patients with T2D greater effects are observed. However, further studies with more solid research designs are required, therefore, caution is needed before prescribing stretching as an exercise intervention for glycaemic management.
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Affiliation(s)
- Ewan Thomas
- Sport and Exercise Sciences Research Unit, Department of Psychology, Educational Science and Human Movement, University of Palermo, Via Giovanni Pascoli 6, 90144, Palermo, Italy.
| | - Salvatore Ficarra
- Sport and Exercise Sciences Research Unit, Department of Psychology, Educational Science and Human Movement, University of Palermo, Via Giovanni Pascoli 6, 90144, Palermo, Italy
| | - Masatoshi Nakamura
- Faculty of Rehabilitation Sciences, Nishi Kyushu University, 4490-9 Ozaki, Kanzaki, Saga, 842-8585, Japan
| | - Patrik Drid
- Faculty of Sport and Physical Education, University of Novi Sad, 21000, Novi Sad, Serbia
| | - Tatjana Trivic
- Faculty of Sport and Physical Education, University of Novi Sad, 21000, Novi Sad, Serbia
| | - Antonino Bianco
- Sport and Exercise Sciences Research Unit, Department of Psychology, Educational Science and Human Movement, University of Palermo, Via Giovanni Pascoli 6, 90144, Palermo, Italy
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2
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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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3
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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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4
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Adams JA, Uryash A, Lopez JR, Sackner MA. The Endothelium as a Therapeutic Target in Diabetes: A Narrative Review and Perspective. Front Physiol 2021; 12:638491. [PMID: 33708143 PMCID: PMC7940370 DOI: 10.3389/fphys.2021.638491] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 01/29/2021] [Indexed: 12/18/2022] Open
Abstract
Diabetes has reached worldwide epidemic proportions, and threatens to be a significant economic burden to both patients and healthcare systems, and an important driver of cardiovascular mortality and morbidity. Improvement in lifestyle interventions (which includes increase in physical activity via exercise) can reduce diabetes and cardiovascular disease mortality and morbidity. Encouraging a population to increase physical activity and exercise is not a simple feat particularly in individuals with co-morbidities (obesity, heart disease, stroke, peripheral vascular disease, and those with cognitive and physical limitations). Translation of the physiological benefits of exercise within that vulnerable population would be an important step for improving physical activity goals and a stopgap measure to exercise. In large part many of the beneficial effects of exercise are due to the introduction of pulsatile shear stress (PSS) to the vascular endothelium. PSS is a well-known stimulus for endothelial homeostasis, and induction of a myriad of pathways which include vasoreactivity, paracrine/endocrine function, fibrinolysis, inflammation, barrier function, and vessel growth and formation. The endothelial cell mediates the balance between vasoconstriction and relaxation via the major vasodilator endothelial derived nitric oxide (eNO). eNO is critical for vasorelaxation, increasing blood flow, and an important signaling molecule that downregulates the inflammatory cascade. A salient feature of diabetes, is endothelial dysfunction which is characterized by a reduction of the bioavailability of vasodilators, particularly nitric oxide (NO). Cellular derangements in diabetes are also related to dysregulation in Ca2+ handling with increased intracellular Ca2+overload, and oxidative stress. PSS increases eNO bioavailability, reduces inflammatory phenotype, decreases intracellular Ca2+ overload, and increases antioxidant capacity. This narrative review and perspective will outline four methods to non-invasively increase PSS; Exercise (the prototype for increasing PSS), Enhanced External Counterpulsation (EECP), Whole Body Vibration (WBV), Passive Simulated Jogging and its predicate device Whole Body Periodic Acceleration, and will discuss current knowledge on their use in diabetes.
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Affiliation(s)
- Jose A Adams
- Division of Neonatology, Mount Sinai Medical Center, Miami Beach, FL, United States
| | - Arkady Uryash
- Division of Neonatology, Mount Sinai Medical Center, Miami Beach, FL, United States
| | - Jose R Lopez
- Department of Research, Mount Sinai Medical Center, Miami Beach, FL, United States
| | - Marvin A Sackner
- Department of Medicine, Mount Sinai Medical Center, Miami Beach, FL, United States
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5
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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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6
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Guo C, Zhao L, Li Y, Deng X, Yuan G. Relationship between FGF21 and drug or nondrug therapy of type 2 diabetes mellitus. J Cell Physiol 2020; 236:55-67. [PMID: 32583417 DOI: 10.1002/jcp.29879] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 06/02/2020] [Accepted: 06/03/2020] [Indexed: 01/06/2023]
Abstract
Sedentary and high-calorie diets are associated with increased risk of obesity and type 2 diabetes mellitus, while exercise and diet control are also important nondrug treatments for diabetes. Fibroblast growth factor 21 (FGF21) is an important cytokine, which is mainly expressed in liver, fat and muscle tissue responding to nutrition and exercise, and plays an important role in the improvement of glucose and lipid metabolism. Due to the increasing serum FGF21 level in obesity and diabetes, FGF21 can be used as a predictor or biomarker of diabetes. A variety of clinical antidiabetic drugs can reduce the content of FGF21, possibly for the improvement of FGF21 sensitivity. In this paper, we reviewed the interactions between FGF21 and nondrug therapy (diet and exercise) for diabetes and explored the potential value of the combined application of clinical antidiabetic drugs and FGF21.
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Affiliation(s)
- Chang Guo
- Department of Endocrinology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Li Zhao
- Department of Endocrinology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Yanyan Li
- Department of Endocrinology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Xia Deng
- Department of Endocrinology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
| | - Guoyue Yuan
- Department of Endocrinology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu, China
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7
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Guigni BA, Fix DK, Bivona JJ, Palmer BM, Carson JA, Toth MJ. Electrical stimulation prevents doxorubicin-induced atrophy and mitochondrial loss in cultured myotubes. Am J Physiol Cell Physiol 2019; 317:C1213-C1228. [PMID: 31532714 DOI: 10.1152/ajpcell.00148.2019] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Muscle contraction may protect against the effects of chemotherapy to cause skeletal muscle atrophy, but the mechanisms underlying these benefits are unclear. To address this question, we utilized in vitro modeling of contraction and mechanotransduction in C2C12 myotubes treated with doxorubicin (DOX; 0.2 μM for 3 days). Myotubes expressed contractile proteins and organized these into functional myofilaments, as electrical field stimulation (STIM) induced intracellular calcium (Ca2+) transients and contractions, both of which were prevented by inhibition of membrane depolarization. DOX treatment reduced myotube myosin content, protein synthesis, and Akt (S308) and forkhead box O3a (FoxO3a; S253) phosphorylation and increased muscle RING finger 1 (MuRF1) expression. STIM (1 h/day) prevented DOX-induced reductions in myotube myosin content and Akt and FoxO3a phosphorylation, as well as increases in MuRF1 expression, but did not prevent DOX-induced reductions in protein synthesis. Inhibition of myosin-actin interaction during STIM prevented contraction and the antiatrophic effects of STIM without affecting Ca2+ cycling, suggesting that the beneficial effect of STIM derives from mechanotransductive pathways. Further supporting this conclusion, mechanical stretch of myotubes recapitulated the effects of STIM to prevent DOX suppression of FoxO3a phosphorylation and upregulation of MuRF1. DOX also increased reactive oxygen species (ROS) production, which led to a decrease in mitochondrial content. Although STIM did not alter DOX-induced ROS production, peroxisome proliferator-activated receptor-γ coactivator-1α and antioxidant enzyme expression were upregulated, and mitochondrial loss was prevented. Our results suggest that the activation of mechanotransductive pathways that downregulate proteolysis and preserve mitochondrial content protects against the atrophic effects of chemotherapeutics.
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Affiliation(s)
- Blas A Guigni
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont.,Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont
| | - Dennis K Fix
- Department of Exercise Science, University of South Carolina, Columbia, South Carolina
| | - Joseph J Bivona
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont
| | - Bradley M Palmer
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont
| | - James A Carson
- Department of Exercise Science, University of South Carolina, Columbia, South Carolina.,Division of Rehabilitation Sciences, College of Health Professions, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Michael J Toth
- Department of Medicine, College of Medicine, University of Vermont, Burlington, Vermont.,Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont, Burlington, Vermont.,Department of Orthopedics and Rehabilitation, College of Medicine, University of Vermont, Burlington, Vermont
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8
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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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9
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Jaldin-Fincati JR, Pavarotti M, Frendo-Cumbo S, Bilan PJ, Klip A. Update on GLUT4 Vesicle Traffic: A Cornerstone of Insulin Action. Trends Endocrinol Metab 2017; 28:597-611. [PMID: 28602209 DOI: 10.1016/j.tem.2017.05.002] [Citation(s) in RCA: 180] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 05/08/2017] [Accepted: 05/09/2017] [Indexed: 12/20/2022]
Abstract
Glucose transport is rate limiting for dietary glucose utilization by muscle and fat. The glucose transporter GLUT4 is dynamically sorted and retained intracellularly and redistributes to the plasma membrane (PM) by insulin-regulated vesicular traffic, or 'GLUT4 translocation'. Here we emphasize recent findings in GLUT4 translocation research. The application of total internal reflection fluorescence microscopy (TIRFM) has increased our understanding of insulin-regulated events beneath the PM, such as vesicle tethering and membrane fusion. We describe recent findings on Akt-targeted Rab GTPase-activating proteins (GAPs) (TBC1D1, TBC1D4, TBC1D13) and downstream Rab GTPases (Rab8a, Rab10, Rab13, Rab14, and their effectors) along with the input of Rac1 and actin filaments, molecular motors [myosinVa (MyoVa), myosin1c (Myo1c), myosinIIA (MyoIIA)], and membrane fusion regulators (syntaxin4, munc18c, Doc2b). Collectively these findings reveal novel events in insulin-regulated GLUT4 traffic.
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Affiliation(s)
| | - Martin Pavarotti
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5J 2L4, Canada; IHEM, Universidad Nacional de Cuyo, CONICET, Mendoza 5500, Argentina
| | - Scott Frendo-Cumbo
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5J 2L4, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Philip J Bilan
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5J 2L4, Canada
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON M5J 2L4, Canada; Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8, Canada.
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10
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Sylow L, Møller LLV, Kleinert M, D'Hulst G, De Groote E, Schjerling P, Steinberg GR, Jensen TE, Richter EA. Rac1 and AMPK Account for the Majority of Muscle Glucose Uptake Stimulated by Ex Vivo Contraction but Not In Vivo Exercise. Diabetes 2017; 66:1548-1559. [PMID: 28389470 DOI: 10.2337/db16-1138] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 03/15/2017] [Indexed: 11/13/2022]
Abstract
Exercise bypasses insulin resistance to increase glucose uptake in skeletal muscle and therefore represents an important alternative to stimulate glucose uptake in insulin-resistant muscle. Both Rac1 and AMPK have been shown to partly regulate contraction-stimulated muscle glucose uptake, but whether those two signaling pathways jointly account for the entire signal to glucose transport is unknown. We therefore studied the ability of contraction and exercise to stimulate glucose transport in isolated muscles with AMPK loss of function combined with either pharmacological inhibition or genetic deletion of Rac1.Muscle-specific knockout (mKO) of Rac1, a kinase-dead α2 AMPK (α2KD), and double knockout (KO) of β1 and β2 AMPK subunits (β1β2 KO) each partially decreased contraction-stimulated glucose transport in mouse soleus and extensor digitorum longus (EDL) muscle. Interestingly, when pharmacological Rac1 inhibition was combined with either AMPK β1β2 KO or α2KD, contraction-stimulated glucose transport was almost completely inhibited. Importantly, α2KD+Rac1 mKO double-transgenic mice also displayed severely impaired contraction-stimulated glucose transport, whereas exercise-stimulated glucose uptake in vivo was only partially reduced by Rac1 mKO with no additive effect of α2KD. It is concluded that Rac1 and AMPK together account for almost the entire ex vivo contraction response in muscle glucose transport, whereas only Rac1, but not α2 AMPK, regulates muscle glucose uptake during submaximal exercise in vivo.
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Affiliation(s)
- Lykke Sylow
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Lisbeth L V Møller
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Maximilian Kleinert
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Gommaar D'Hulst
- Department of Kinesiology, Exercise Physiology Research Group, Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Leuven, Belgium
| | | | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopedic Surgery, Bispebjerg Hospital, Copenhagen, Denmark
- Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Thomas E Jensen
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Erik A Richter
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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11
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Tanimura Y, Aoi W, Takanami Y, Kawai Y, Mizushima K, Naito Y, Yoshikawa T. Acute exercise increases fibroblast growth factor 21 in metabolic organs and circulation. Physiol Rep 2016; 4:4/12/e12828. [PMID: 27335433 PMCID: PMC4923231 DOI: 10.14814/phy2.12828] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 05/20/2016] [Indexed: 12/22/2022] Open
Abstract
Fibroblast growth factor 21, a metabolic regulator, plays roles in lipolysis and glucose uptake in adipose tissues and skeletal muscles. Its expression in skeletal muscle is upregulated upon activation of the phosphatidylinositol 3‐kinase/Akt signaling pathway, which is induced by exercise and muscle contraction. We examined the increase of fibroblast growth factor 21 after acute exercise in metabolic organs, especially skeletal muscles and circulation. Participants exercised on bicycle ergometers for 60 min at 75% of their V˙O2max. Venous blood samples were taken before exercise and immediately after exercise. In an animal study, male ICR mice were divided into sedentary and exercise groups. Mice in the exercise group performed treadmill exercises at 30 m min−1 for 60 min. Shortly thereafter, blood, liver, and skeletal muscle samples were taken from mice. Acute exercise induced the increase of serum fibroblast growth factor 21 in both humans and mice, and increased fibroblast growth factor 21 expression in the skeletal muscles and the liver of mice. Acute exercise activated Akt in mice skeletal muscle. Acute exercise increases fibroblast growth factor 21 concentrations in both serum and metabolic organs. Moreover, results show that acute exercise increased the expression of fibroblast growth factor 21 in skeletal muscle, accompanied by the phosphorylation of Akt in mice.
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Affiliation(s)
- Yuko Tanimura
- Department of Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kyoto, Japan Faculty of human, Aichi-toho University, Nagoya, Japan
| | - Wataru Aoi
- Laboratory of Health Science, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Kyoto, Japan
| | | | - Yukari Kawai
- Louis Pasteur Center for Medical Research, Kyoto, Japan
| | - Katsura Mizushima
- Department of Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Yuji Naito
- Department of Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Toshikazu Yoshikawa
- Department of Molecular Gastroenterology and Hepatology, Kyoto Prefectural University of Medicine, Kyoto, Japan
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Manabe Y, Fujii NL. Experimental research models for skeletal muscle contraction. ACTA ACUST UNITED AC 2016. [DOI: 10.7600/jpfsm.5.373] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Yasuko Manabe
- Department of Health Promotion Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University
| | - Nobuharu L. Fujii
- Department of Health Promotion Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University
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Ko SC, Kim JI, Park SJ, Jung WK, Jeon YJ. Antihypertensive peptide purified from Styela clava flesh tissue stimulates glucose uptake through AMP-activated protein kinase (AMPK) activation in skeletal muscle cells. Eur Food Res Technol 2015. [DOI: 10.1007/s00217-015-2526-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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14
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Sylow L, Møller LLV, Kleinert M, Richter EA, Jensen TE. Stretch-stimulated glucose transport in skeletal muscle is regulated by Rac1. J Physiol 2015; 593:645-56. [PMID: 25416624 DOI: 10.1113/jphysiol.2014.284281] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 11/13/2014] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Rac1 regulates stretch-stimulated (i.e. mechanical stress) glucose transport in muscle. Actin depolymerization decreases stretch-induced glucose transport in skeletal muscle. Rac1 is a required part of the mechanical stress-component of the contraction-stimulus to glucose transport in skeletal muscle. ABSTRACT An alternative to the canonical insulin signalling pathway for glucose transport is muscle contraction/exercise. Mechanical stress is an integrated part of the muscle contraction/relaxation cycle, and passive stretch stimulates muscle glucose transport. However, the signalling mechanism regulating stretch-stimulated glucose transport is not well understood. We recently reported that the actin cytoskeleton regulating GTPase, Rac1, was activated in mouse muscle in response to stretching. Rac1 is a regulator of contraction- and insulin-stimulated glucose transport, however, its role in stretch-stimulated glucose transport and signalling is unknown. We therefore investigated whether stretch-induced glucose transport in skeletal muscle required Rac1 and the actin cytoskeleton. We used muscle-specific inducible Rac1 knockout mice as well as pharmacological inhibitors of Rac1 and the actin cytoskeleton in isolated soleus and extensor digitorum longus muscles. In addition, the role of Rac1 in contraction-stimulated glucose transport during conditions without mechanical load on the muscles was evaluated in loosely hanging muscles and muscles in which cross-bridge formation was blocked by the myosin ATPase inhibitors BTS and Blebbistatin. Knockout as well as pharmacological inhibition of Rac1 reduced stretch-stimulated glucose transport by 30-50% in soleus and extensor digitorum longus muscle. The actin depolymerizing agent latrunculin B similarly decreased glucose transport in response to stretching by 40-50%. Rac1 inhibition reduced contraction-stimulated glucose transport by 30-40% in tension developing muscle but did not affect contraction-stimulated glucose transport in muscles in which force development was prevented. Our findings suggest that Rac1 and the actin cytoskeleton regulate stretch-stimulated glucose transport and that Rac1 is a required part of the mechanical stress-component of the contraction-stimulus to glucose transport in skeletal muscle.
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Affiliation(s)
- Lykke Sylow
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
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15
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Evertsson K, Fjällström AK, Norrby M, Tågerud S. p38 mitogen-activated protein kinase and mitogen-activated protein kinase-activated protein kinase 2 (MK2) signaling in atrophic and hypertrophic denervated mouse skeletal muscle. J Mol Signal 2014; 9:2. [PMID: 24629011 PMCID: PMC3995524 DOI: 10.1186/1750-2187-9-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 03/10/2014] [Indexed: 11/10/2022] Open
Abstract
Background p38 mitogen-activated protein kinase has been implicated in both skeletal muscle atrophy and hypertrophy. T317 phosphorylation of the p38 substrate mitogen-activated protein kinase-activated protein kinase 2 (MK2) correlates with muscle weight in atrophic and hypertrophic denervated muscle and may influence the nuclear and cytoplasmic distribution of p38 and/or MK2. The present study investigates expression and phosphorylation of p38, MK2 and related proteins in cytosolic and nuclear fractions from atrophic and hypertrophic 6-days denervated skeletal muscles compared to innervated controls. Methods Expression and phosphorylation of p38, MK2, Hsp25 (heat shock protein25rodent/27human, Hsp25/27) and Hsp70 protein expression were studied semi-quantitatively using Western blots with separated nuclear and cytosolic fractions from innervated and denervated hypertrophic hemidiaphragm and atrophic anterior tibial muscles. Unfractionated innervated and denervated atrophic pooled gastrocnemius and soleus muscles were also studied. Results No support was obtained for a differential nuclear/cytosolic localization of p38 or MK2 in denervated hypertrophic and atrophic muscle. The differential effect of denervation on T317 phosphorylation of MK2 in denervated hypertrophic and atrophic muscle was not reflected in p38 phosphorylation nor in the phosphorylation of the MK2 substrate Hsp25. Hsp25 phosphorylation increased 3-30-fold in all denervated muscles studied. The expression of Hsp70 increased 3-5-fold only in denervated hypertrophic muscles. Conclusions The study confirms a differential response of MK2 T317 phosphorylation in denervated hypertrophic and atrophic muscles and suggests that Hsp70 may be important for this. Increased Hsp25 phosphorylation in all denervated muscles studied indicates a role for factors other than MK2 in the regulation of this phosphorylation.
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Affiliation(s)
- Kim Evertsson
- Department of Chemistry and Biomedical Sciences, Linnaeus University, SE-391 82 Kalmar, Sweden.
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16
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Characterization of an acute muscle contraction model using cultured C2C12 myotubes. PLoS One 2012; 7:e52592. [PMID: 23300713 PMCID: PMC3534077 DOI: 10.1371/journal.pone.0052592] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 11/16/2012] [Indexed: 11/19/2022] Open
Abstract
A cultured C2C12 myotube contraction system was examined for application as a model for acute contraction-induced phenotypes of skeletal muscle. C2C12 myotubes seeded into 4-well rectangular plates were placed in a contraction system equipped with a carbon electrode at each end. The myotubes were stimulated with electric pulses of 50 V at 1 Hz for 3 ms at 997-ms intervals. Approximately 80% of the myotubes were observed to contract microscopically, and the contractions lasted for at least 3 h with electrical stimulation. Calcium ion (Ca2+) transient evoked by the electric pulses was detected fluorescently with Fluo-8. Phosphorylation of protein kinase B/Akt (Akt), 5′ AMP-activated protein kinase (AMPK), p38 mitogen-activated protein kinase (p38), and c-Jun NH2-terminal kinase (JNK)1/2, which are intracellular signaling proteins typically activated in exercised/contracted skeletal muscle, was observed in the electrically stimulated C2C12 myotubes. The contractions induced by the electric pulses increased glucose uptake and depleted glycogen in the C2C12 myotubes. C2C12 myotubes that differentiated after exogenous gene transfection by a lipofection or an electroporation method retained their normal contractile ability by electrical stimulation. These findings show that our C2C12 cell contraction system reproduces the muscle phenotypes that arise invivo (exercise), in situ (hindlimb muscles in an anesthetized animal), and invitro (dissected muscle tissues in incubation buffer) by acute muscle contraction, demonstrating that the system is applicable for the analysis of intracellular events evoked by acute muscle contraction.
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Hunter SD, Tarumi T, Dhindsa MS, Nualnim N, Tanaka H. Hatha yoga and vascular function: results from cross-sectional and interventional studies. J Bodyw Mov Ther 2012; 17:322-7. [PMID: 23768276 DOI: 10.1016/j.jbmt.2012.10.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 09/21/2012] [Accepted: 10/09/2012] [Indexed: 11/25/2022]
Abstract
The aim of this study was to determine the effect of hatha yoga on arterial elasticity and endothelial function. First, a cross-sectional study was performed to determine whether yoga practitioners would demonstrate greater arterial compliance and endothelium-dependent vasodilation than their sedentary peers. Second, an intervention study involving 13 sedentary middle-aged and older adults (51 ± 7 years) was performed to determine whether 12 weeks of hatha yoga would elicit increases in arterial compliance and endothelial function. In the cross-sectional study involving a total of 34 subjects, there were no group differences in body fatness, blood lipid and lipoprotein concentrations, carotid artery compliance or brachial artery flow-mediated dilation (FMD). Hemoglobin A1c was lower in yoga practitioners than in sedentary adults (P < 0.05). Total cholesterol and hemoglobin A1c decreased after the intervention (P < 0.05) while carotid artery compliance and brachial artery FMD did not change. The results of both cross-sectional and interventional studies indicate that regular practice of hatha yoga is not associated with improvements in vascular functions.
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Affiliation(s)
- Stacy D Hunter
- Cardiovascular Aging Research Laboratory, Department of Kinesiology and Health Education, The University of Texas at Austin, TX 78712, USA.
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18
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Jo K, Lee SE, Lee SW, Hwang JK. Prunus yedoensis Matsum. stimulates glucose uptake in L6 rat skeletal muscle cells by activating AMP-activated protein kinase and phosphatidylinositol 3-kinase/Akt pathways. Nat Prod Res 2011; 26:1610-5. [PMID: 21809954 DOI: 10.1080/14786419.2011.574133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Prunus yedoensis Matsum. is used as a medicinal plant to alleviate symptoms of diabetes; however, the molecular mechanism underlying its antihyperglycaemic activity is unknown. In this study, we investigated the antihyperglycaemic effects of P. yedoensis and its molecular mechanism. Prunus yedoensis leaf extract (PLE) increased the glucose uptake of phosphorylatinginsulin receptor substrate (IRS)-1, 3'-phosphoinositide-dependent kinase (PDK)-1 and Akt PLE, and also increased the phosphorylation of AMP-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase (p38 MAPK). PLE-stimulated glucose uptake was blocked by an AMPK inhibitor (Compound C) and a p38 MAPK inhibitor (SB203580). Inhibition of AMPK activity reduced p38 MAPK phosphorylation, whereas the inhibition of p38 MAPK activity did not affect AMPK phosphorylation. Pretreatment with the phosphatidylinositol 3-kinase inhibitor LY294002 and Compound C reduced PLE-stimulated glucose uptake. Our results demonstrate that PLE stimulated glucose uptake by activating both insulin signalling and AMPK-p38 MAPK pathways. PLE shows potential as a natural antihyperglycaemic agent.
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Affiliation(s)
- Keanae Jo
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, 262 Seongsanno, Seodaemun-gu, Seoul 120-749, Korea
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19
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Yano S, Morino-Koga S, Kondo T, Suico MA, Koga T, Shimauchi Y, Matsuyama S, Shuto T, Sato T, Araki E, Kai H. Glucose Uptake in Rat Skeletal Muscle L6 Cells Is Increased by Low-Intensity Electrical Current Through the Activation of the Phosphatidylinositol-3-OH Kinase (PI-3K) / Akt Pathway. J Pharmacol Sci 2011; 115:94-8. [DOI: 10.1254/jphs.10185sc] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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20
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Norrby M, Tågerud S. Mitogen-activated protein kinase-activated protein kinase 2 (MK2) in skeletal muscle atrophy and hypertrophy. J Cell Physiol 2010; 223:194-201. [PMID: 20049871 DOI: 10.1002/jcp.22023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Skeletal muscle is a highly plastic tissue. Overall muscle growth (hypertrophy) or muscle wasting (atrophy) results from alterations in intracellular signaling pathways with important regulatory steps occurring in the nucleus as well as in the cytoplasm. Previous studies have identified components of the Akt/mTor pathway as well as the p38 MAPK pathway as important for skeletal muscle hypertrophy and/or atrophy. The present study tests the hypothesis that MK2, a substrate of p38 which following phosphorylation, can be exported from the nucleus in a complex with p38, may be important for skeletal muscle growth. The expression of MK2 was examined in denervated mouse hind-limb (atrophic) and hemidiaphragm (transiently hypertrophic) muscles. MK2 mRNA expression decreased after denervation in both atrophic (48% of innervated controls, P < 0.001) and hypertrophic muscle (34% of innervated controls, P < 0.01) but MK2 protein expression decreased only in atrophic muscle (32% of innervated controls, P < 0.01). The level of T205 phosphorylated MK2 increased after denervation in both atrophic (fourfold increase, P < 0.01) and hypertrophic muscles (almost sevenfold increase, P < 0.001) whereas the level of T317 phosphorylated MK2 (necessary for nuclear export) increased after denervation in hypertrophic muscle (nearly threefold increase, P < 0.001) but not in atrophic muscle. Logarithmically transformed relative changes in MK2 phosphorylated at T317 correlated well (r(2) = 0.7737) with relative changes in muscle weight. The results suggest a role for MK2 in the regulation of muscle mass, a role which, at least in part, may be related to determining the subcellular localization of p38 in muscle fibers.
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Affiliation(s)
- Marlene Norrby
- School of Pure and Applied Natural Sciences, University of Kalmar, Kalmar, Sweden.
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21
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Lee MS, Hwang JT, Kim SH, Yoon S, Kim MS, Yang HJ, Kwon DY. Ginsenoside Rc, an active component of Panax ginseng, stimulates glucose uptake in C2C12 myotubes through an AMPK-dependent mechanism. JOURNAL OF ETHNOPHARMACOLOGY 2010; 127:771-6. [PMID: 19961916 DOI: 10.1016/j.jep.2009.11.022] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 11/20/2009] [Accepted: 11/24/2009] [Indexed: 05/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Panax ginseng and its major component, ginsenosides, are widely used for the prevention of various disorders in oriental medicine. AIM OF THE STUDY To evaluate the effect of ginsenoside Rc (Rc), one of the active constituents in Panax ginseng, on glucose uptake in C2C12 myotubes. RESULTS Treatment of the C2C12 myotubes with Rc significantly increased glucose uptake. To determine the mechanism of Rc-induced glucose uptake, either insulin-dependent signaling or insulin-independent signaling pathway activities were measured using western blot analysis. We showed that Rc significantly activated an insulin-independent AMPK signaling pathway. However, Rc had no effect on the components of the insulin-dependent signaling pathway, such as receptor substrates (IRS)-1 and protein kinase B or Akt (PKB/Akt). Moreover, we found that treatment with an AMPK inhibitor abolished both glucose uptake and p38 MAPK phosphorylation. This result implies that AMPK activity is critical for the Rc-induced glucose uptake and that AMPK is situated upstream of p38 MAPK. In addition, we also showed that the activation of AMPK and p38 induced by ginsenoside Rc is mediated by reactive oxygen species (ROS) production, suggesting that upstream regulators of AMPK- and p38 MAPK-mediated glucose uptake. CONCLUSION Ginsenoside Rc significantly enhances glucose uptake by inducing ROS generation, which leads to AMPK and p38 MAPK activation. Consequently, ginsenoside Rc can be used as a potent natural anti-diabetic agent.
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Affiliation(s)
- Myoung-Su Lee
- Biogeron Research Center, Korea Food Research Institute, Bundang-ku, Songnam, Republic of Korea
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22
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Ikemoto T, Hosoya T, Takata K, Aoyama H, Hiramatsu T, Onoe H, Suzuki M, Endo M. Functional role of neuroendocrine-specific protein-like 1 in membrane translocation of GLUT4. Diabetes 2009; 58:2802-12. [PMID: 19720795 PMCID: PMC2780876 DOI: 10.2337/db09-0756] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE In skeletal muscles, dantrolene inhibits the exercise-induced membrane translocation of GLUT4. It has been postulated that the inhibitory action of dantrolene on Ca(2+) release from the sarcoplasmic reticulum (SR) causes inhibition of exercise-induced glucose uptake; however, the precise mechanism has not been adequately studied. RESEARCH DESIGN AND METHODS We discovered that dantrolene can bind to skeletal-type neuroendocrine-specific protein-like 1 (sk-NSPl1) with photoreactive dantrolene derivatives. In sk-NSPl1-deficient muscles, we examined the change in glucose uptake and the membrane translocation of GLUT4. In addition, we examined the change in blood glucose and also measured the glycogen level in both isolated and in situ skeletal muscles after electrical stimulation using our mutant mouse. RESULTS In sk-NSPl1-deficient muscles, exercise-induced glucose uptake was totally abolished with no change in insulin-induced glucose uptake. The Ca(2+) release mechanism and its inhibition by dantrolene were completely preserved in these muscles. The expression of GLUT4 in the mutant muscles also appeared unchanged. Confocal imaging and results using the membrane isolation method showed that exercise/contraction did not enhance GLUT4 translocation in these sk-NSPl1-deficient muscles under conditions of adequate muscle glycogen consumption. The blood glucose level in normal mice was reduced by electrical stimulation of the hind limbs, but that in mutant mice was unchanged. CONCLUSIONS sk-NSPl1 is a novel dantrolene receptor that plays an important role in membrane translocation of GLUT4 induced by contraction/exercise. The 23-kDa sk-NSPl1 may also be involved in the regulation of glucose levels in the whole body.
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Affiliation(s)
- Takaaki Ikemoto
- Functional Probe Research Laboratory, RIKEN Center for Molecular Imaging Science, Kobe, Japan.
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Babraj JA, Mustard K, Sutherland C, Towler MC, Chen S, Smith K, Green K, Leese G, Hardie DG, Rennie MJ, Cuthbertson DJ. Blunting of AICAR-induced human skeletal muscle glucose uptake in type 2 diabetes is dependent on age rather than diabetic status. Am J Physiol Endocrinol Metab 2009; 296:E1042-8. [PMID: 19190259 PMCID: PMC2681307 DOI: 10.1152/ajpendo.90811.2008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
We demonstrated previously that, in healthy young men, 5-aminoimidazole-4-carboxamide 1-beta-d-ribofuranoside (AICAR) stimulates human muscle 2-deoxyglucose (2DG) uptake without detectable activation of muscle AMP-activated protein kinase (AMPK) but with extracellular-regulated kinase 1/2 (ERK1/2) activation. We tested whether AICAR stimulates muscle 2DG uptake in healthy older patients with or without type 2 diabetes (T2D). Six healthy young subjects (23 +/- 3 yr, BMI 25 +/- 2 kg/m(-2); means +/- SE), eight older subjects (59 +/- 4 yr, BMI 28 +/- 2 kg/m(-2)), and eight subjects with T2D (62 +/- 4 yr, BMI 27 +/- 2 kg/m(-2)) received a 6-h 2DG infusion (prime 10 mg/kg, 6 mg.kg(-1).h(-1)) and AICAR (10 or 20 mg.kg(-1).h(-1)) from 3 to 6 h. Quadriceps biopsies were taken at 0, 3, and 6 h. We determined 1) 2DG uptake, 2) total AMPKalpha activity, AMPK, acetyl-CoA carboxylase (ACC), and AS160 phosphorylation, and 3) ERK1/2 phosphorylation. Ten milligrams per kilogram per hour AICAR increased 2DG uptake by 2.9 +/- 0.7-fold in young men (P < 0.001), 1.8 +/- 0.2-fold in older men (P < 0.01), and 1.6 +/- 0.1-fold in men with T2D; 20 mg.kg(-1).h(-1) AICAR increases were 2.5 +/- 0.1-fold (older men, P < 0.001) and 2.2 +/- 0.2-fold (men with T2D, P < 0.001). At 3-h AMPK activity and AMPK, ACC and AS160 phosphorylation were unchanged, but ERK1/2 phosphorylation increased at both AICAR doses. The fold changes of ERK1/2 phosphorylation and 2DG uptake closely correlated (R(2) = 0.55, P = 0.003). AICAR stimulates muscle 2DG uptake in T2D to the same extent as in healthy age-matched controls, but there is an age-related reduction.
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Affiliation(s)
- John Andree Babraj
- Department of Diabetes, Clinical Sciences Centre, University Hospital Aintree, Liverpool, L9 7AL, UK
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Blair DR, Funai K, Schweitzer GG, Cartee GD. A myosin II ATPase inhibitor reduces force production, glucose transport, and phosphorylation of AMPK and TBC1D1 in electrically stimulated rat skeletal muscle. Am J Physiol Endocrinol Metab 2009; 296:E993-E1002. [PMID: 19190254 PMCID: PMC2681314 DOI: 10.1152/ajpendo.91003.2008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Contraction-stimulated glucose transport by skeletal muscle appears to be caused by the cumulative effects of multiple inputs [potentially including AMP-activated protein kinase (AMPK), Ca(2+) flux, and force production], making it challenging to isolate the roles of these putative regulatory factors. To distinguish the effects of force production from the direct consequences of Ca(2+) flux, the predominantly type II rat epitrochlearis muscle was incubated without (vehicle) or with N-benzyl-p-toluenesulfonamide (BTS), a highly specific myosin II ATPase inhibitor that prevents force production by electrically stimulated (ES) type II fibers without altering cytosolic Ca(2+). In ES muscles, BTS vs. vehicle had an 84% reduction in force production and a 57% decrement in contraction-stimulated 3-O-methylglucose transport (3MGT). BTS did not alter the ES increase in phosphorylation of CaMKII (indicative of cytosolic Ca(2+)) or the amount of glycogen depletion. ES caused significant reductions in ATP (48%) and phosphocreatine (67%) concentrations for vehicle-treated muscles. For BTS-treated muscles, ES did not reduce ATP and caused only a 42% decrease in phosphocreatine. There was an ES increase in phosphorylation of AMPK, acetyl-CoA carboxylase (an AMPK substrate), and TBC1D1 for vehicle-treated muscles but not for BTS-treated muscles. These results point toward an essential role for tension-related events, including AMPK activation, in the 57% contraction-stimulated increase in 3MGT that was inhibited by BTS and further suggest a possible role for TBC1D1 phosphorylation. Non-tension-related events (e.g., increased cytosolic Ca(2+) rather than increased AMPK and TBC1D1 phosphorylation) are implicated in the contraction-stimulated increase in 3MGT that persisted in the presence of BTS.
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Affiliation(s)
- David R Blair
- University of Michigan, Division of Kinesiology, Ann Arbor, MI 48109-2214, USA
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Wu PI, Minisini S, Edelman ER. Intramuscular drug transport under mechanical loading: resonance between tissue function and uptake. J Control Release 2009; 136:99-109. [PMID: 19331855 DOI: 10.1016/j.jconrel.2009.01.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 01/09/2009] [Accepted: 01/25/2009] [Indexed: 11/29/2022]
Abstract
Dynamic architecture and motion in mechanically active target tissues can influence the pharmacokinetics of locally delivered agents. Drug transport in skeletal muscle under controlled mechanical loads was investigated. Static (0-20%) and cyclic (+/-2.5% amplitude, 0-20% mean, 1-3 Hz) strains and electrically paced isometric contractions (0.1-3 Hz, 0% strain) were applied to rat soleus incubated in 1 mM 20 kDa FITC-dextran. Dextran penetration, tissue porosity, and active force-length relationship over 0-20% strain correlated (r=0.9-1.0), and all increased 1.5-fold from baseline at 0% to a maximum at 10% (Lo), demonstrating biologic significance of Lo and impact of fiber size and distribution on function and pharmacokinetics. Overall penetration decreased but relative enhancement of penetration at Lo increased with dextran size (4-150 kDa). Penetration increased linearly (0.084 mm/Hz) with cyclic stretch, demonstrating dispersion. Penetration increased with contraction rate by 1.5-fold from baseline to a maximum at 0.5 Hz, revealing architectural modulation of dispersion. Impact of architecture and dispersion on intramuscular transport was computationally modeled. Mechanical architecture and function underlie intramuscular pharmacokinetics and act in concert to effect resonance between optimal physiologic performance and drug uptake. Therapeutic management of characteristic function in tissue targets may enable a physiologic mechanism for controlled drug transport.
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Affiliation(s)
- Peter I Wu
- Biomedical Engineering Center, Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, E25-438, Cambridge, Massachusetts 02139, USA
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Nedachi T, Fujita H, Kanzaki M. Contractile C2C12 myotube model for studying exercise-inducible responses in skeletal muscle. Am J Physiol Endocrinol Metab 2008; 295:E1191-204. [PMID: 18780777 DOI: 10.1152/ajpendo.90280.2008] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Adequate exercise leads to a vast variety of physiological changes in skeletal muscle as well as other tissues/organs and is also responsible for maintaining healthy muscle displaying enhanced insulin-responsive glucose uptake via GLUT4 translocation. We generated highly developed contractile C(2)C(12) myotubes by manipulating intracellular Ca(2+) transients with electric pulse stimulation (EPS) that is endowed with properties similar to those of in vivo skeletal muscle in terms of 1) excitation-induced contractile activity as a result of de novo sarcomere formation, 2) activation of both the AMP kinase and stress-activated MAP kinase cascades, and 3) improved insulin responsiveness as assessed by GLUT4 recycling. Tbc1d1, a Rab-GAP implicated in exercise-induced GLUT4 translocation in skeletal muscle, also appeared to be phosphorylated on Ser(231) after EPS-induced contraction. In addition, a switch in myosin heavy-chain (MHC) expression from "fast type" to "slow type" was observed in the C(2)C(12) myotubes endowed with EPS-induced repetitive contractility. Taking advantage of these highly developed contractile C(2)C(12) myotubes, we identified myotube-derived factors responsive to EPS-evoked contraction, including the CXC chemokines CXCL1/KC and CXCL5/LIX, as well as IL-6, previously reported to be upregulated in contracting muscles in vivo. Importantly, animal treadmill experiments revealed that exercise significantly increased systemic levels of CXCL1/KC, perhaps derived from contracting muscle. Taken together, these results confirm that we have established a specialized muscle cell culture model allowing contraction-inducible cellular responses to be explored. Utilizing this model, we identified contraction-inducible myokines potentially linked to the metabolic alterations, immune responses, and angiogenesis induced by exercise.
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Affiliation(s)
- Taku Nedachi
- Center for Research Strategy and Support, Tohoku University Biomedical Engineering Research Organization, Sendai, Japan
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Iwata M, Hayakawa K, Murakami T, Naruse K, Kawakami K, Inoue-Miyazu M, Yuge L, Suzuki S. Uniaxial cyclic stretch-stimulated glucose transport is mediated by a ca-dependent mechanism in cultured skeletal muscle cells. Pathobiology 2007; 74:159-68. [PMID: 17643061 DOI: 10.1159/000103375] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Accepted: 12/29/2006] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Mechanical stimuli such as stretch increase glucose transport and glycogen metabolism in skeletal muscle. However, the molecular mechanisms involved in the mechanotransduction events are poorly understood. The present study was conducted in order to determine whether the signaling mechanism leading to mechanical stretch-stimulated glucose transport is similar to, or distinct from, the signaling mechanisms leading to insulin- and contraction-stimulated glucose transport in cultured muscle cells. METHODS Cultured C2C12 myotubes were stretched, after which the 2-deoxy-D-glucose (2-DG) uptake was measured. RESULTS Following cyclic stretch, C2C12 myotubes showed a significant increase in 2-DG uptake, and this effect was not prevented by inhibiting phosphatidylinositol 3-kinase or 5'-AMP-activated protein kinase and by extracellular Ca(2+) chelation. Conversely, the stretch-stimulated 2-DG uptake was completely prevented by dantrolene (an inhibitor of Ca(2+) release from sarcoplasmic reticulum). Furthermore, the stretch-stimulated 2-DG uptake was prevented by the Ca(2+)/calmodulin-dependent kinase inhibitor KN93 which did not prevent the insulin-stimulated 2-DG uptake. CONCLUSIONS These results suggest that the effects of stretch-stimulated glucose transport are independent of the insulin-signaling pathway. By contrast, following mechanical stretch in skeletal muscle, the signal transduction pathway leading to glucose transport may require the participation of cytosolic Ca(2+) and Ca(2+)/calmodulin kinase, but not 5'-AMP-activated protein kinase.
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Affiliation(s)
- Masahiro Iwata
- Program in Physical and Occupational Therapy, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Fujii N, Jessen N, Goodyear LJ. AMP-activated protein kinase and the regulation of glucose transport. Am J Physiol Endocrinol Metab 2006; 291:E867-77. [PMID: 16822958 DOI: 10.1152/ajpendo.00207.2006] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The AMP-activated protein kinase (AMPK) is an energy-sensing enzyme that is activated by acute increases in the cellular [AMP]/[ATP] ratio. In skeletal and/or cardiac muscle, AMPK activity is increased by stimuli such as exercise, hypoxia, ischemia, and osmotic stress. There are many lines of evidence that increasing AMPK activity in skeletal muscle results in increased rates of glucose transport. Although similar to the effects of insulin to increase glucose transport in muscle, it is clear that the underlying mechanisms for AMPK-mediated glucose transport involve proximal signals that are distinct from that of insulin. Here, we discuss the evidence for AMPK regulation of glucose transport in skeletal and cardiac muscle and describe research investigating putative signaling mechanisms mediating this effect. We also discuss evidence that AMPK may play a role in enhancing muscle and whole body insulin sensitivity for glucose transport under conditions such as exercise, as well as the use of the AMPK activator AICAR to reverse insulin-resistant conditions. The identification of AMPK as a novel glucose transport mediator in skeletal muscle is providing important insights for the treatment and prevention of type 2 diabetes.
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Affiliation(s)
- Nobuharu Fujii
- Research Division, Joslin Diabetes Center and Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02215, USA
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Nakayama K. [Mechanotransduction and cellular response--a challenge toward development of mechano-pharmacology]. YAKUGAKU ZASSHI 2006; 126:565-77. [PMID: 16880716 DOI: 10.1248/yakushi.126.565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mechanoreception and subsequent cellular/molecular mechanisms of signal transduction pathways in response to mechanical stresses, including hemodynamic factors, passive stretching, and exercise, are ubiquitous in living organisms. Of these, the cardiovascular system involving the heart and blood vessels is known to be particularly sensitive to mechanical stimuli, for example, stretching and intraluminal pressurization, which might mimic an acute and/or chronic change in blood pressure and flow, induce a variety of responses including contraction, activation of various kinases and ionic channels, production of vasoactive substances, gene expression, and phenotype changes. We have started to clarify the mechanisms underlying this basic principle in the cardiovascular system as it is now generally considered that obesity and a lack of exercise are serious risk factors for cardiovascular diseases such as hypertension, atherosclerosis, and type 2 diabetes. We further extended our research field of mechanotransduction into adipocytes, skeletal muscle cells, and pancreatic beta cells, all of which are related to the core concerns in cardiovascular disease, including the so-called metabolic syndrome. In the present article, we discuss briefly the prologue to our study of mechanotransduction and several topics in the recent progress in this interesting area. We also emphasize that it is important to recognize biomechanical factors and control them not only for improvement in our knowledge of health and disease but also for the development of new drugs.
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Affiliation(s)
- Koichi Nakayama
- Department of Cellular and Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, University of Shizuoka, Japan.
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