1
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Stocks B, Zierath JR. Post-translational Modifications: The Signals at the Intersection of Exercise, Glucose Uptake, and Insulin Sensitivity. Endocr Rev 2022; 43:654-677. [PMID: 34730177 PMCID: PMC9277643 DOI: 10.1210/endrev/bnab038] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Indexed: 11/19/2022]
Abstract
Diabetes is a global epidemic, of which type 2 diabetes makes up the majority of cases. Nonetheless, for some individuals, type 2 diabetes is eminently preventable and treatable via lifestyle interventions. Glucose uptake into skeletal muscle increases during and in recovery from exercise, with exercise effective at controlling glucose homeostasis in individuals with type 2 diabetes. Furthermore, acute and chronic exercise sensitizes skeletal muscle to insulin. A complex network of signals converge and interact to regulate glucose metabolism and insulin sensitivity in response to exercise. Numerous forms of post-translational modifications (eg, phosphorylation, ubiquitination, acetylation, ribosylation, and more) are regulated by exercise. Here we review the current state of the art of the role of post-translational modifications in transducing exercise-induced signals to modulate glucose uptake and insulin sensitivity within skeletal muscle. Furthermore, we consider emerging evidence for noncanonical signaling in the control of glucose homeostasis and the potential for regulation by exercise. While exercise is clearly an effective intervention to reduce glycemia and improve insulin sensitivity, the insulin- and exercise-sensitive signaling networks orchestrating this biology are not fully clarified. Elucidation of the complex proteome-wide interactions between post-translational modifications and the associated functional implications will identify mechanisms by which exercise regulates glucose homeostasis and insulin sensitivity. In doing so, this knowledge should illuminate novel therapeutic targets to enhance insulin sensitivity for the clinical management of type 2 diabetes.
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Affiliation(s)
- Ben Stocks
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Juleen R Zierath
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.,Departments of Molecular Medicine and Surgery and Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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2
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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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3
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McConell GK, Wadley GD, Le Plastrier K, Linden KC. Skeletal muscle AMPK is not activated during 2 h of moderate intensity exercise at ∼65% V ̇ O 2 peak in endurance trained men. J Physiol 2020; 598:3859-3870. [PMID: 32588910 PMCID: PMC7540472 DOI: 10.1113/jp277619] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Accepted: 06/17/2020] [Indexed: 12/22/2022] Open
Abstract
Key points AMP‐activated protein kinase (AMPK) is considered a major regulator of skeletal muscle metabolism during exercise. However, we previously showed that, although AMPK activity increases by 8–10‐fold during ∼120 min of exercise at ∼65% V˙O2peak in untrained individuals, there is no increase in these individuals after only 10 days of exercise training (longitudinal study). In a cross‐sectional study, we show that there is also a lack of activation of skeletal muscle AMPK during 120 min of cycling exercise at 65% V˙O2peak in endurance‐trained individuals. These findings indicate that AMPK is not an important regulator of exercise metabolism during 120 min of exercise at 65% V˙O2peak in endurance trained men. It is important that more energy is directed towards examining other potential regulators of exercise metabolism.
Abstract AMP‐activated protein kinase (AMPK) is considered a major regulator of skeletal muscle metabolism during exercise. Indeed, AMPK is activated during exercise and activation of AMPK by 5‐aminoimidazole‐4‐carboxyamide‐ribonucleoside (AICAR) increases skeletal muscle glucose uptake and fat oxidation. However, we have previously shown that, although AMPK activity increases by 8–10‐fold during ∼120 min of exercise at ∼65% V˙O2peak in untrained individuals, there is no increase in these individuals after only 10 days of exercise training (longitudinal study). In a cross‐sectional study, we examined whether there is also a lack of activation of skeletal muscle AMPK during 120 min of cycling exercise at 65% V˙O2peak in endurance‐trained individuals. Eleven untrained (UT; V˙O2peak = 37.9 ± 5.6 ml.kg−1 min−1) and seven endurance trained (ET; V˙O2peak = 61.8 ± 2.2 ml.kg−1 min−1) males completed 120 min of cycling exercise at 66 ± 4% V˙O2peak (UT: 100 ± 21 W; ET: 190 ± 15 W). Muscle biopsies were obtained at rest and following 30 and 120 min of exercise. Muscle glycogen was significantly (P < 0.05) higher before exercise in ET and decreased similarly during exercise in the ET and UT individuals. Exercise significantly increased calculated skeletal muscle free AMP content and more so in the UT individuals. Exercise significantly (P < 0.05) increased skeletal muscle AMPK α2 activity (4‐fold), AMPK αThr172 phosphorylation (2‐fold) and ACCβ Ser222 phosphorylation (2‐fold) in the UT individuals but not in the ET individuals. These findings indicate that AMPK is not an important regulator of exercise metabolism during 120 min of exercise at 65% V˙O2peak in endurance trained men. AMP‐activated protein kinase (AMPK) is considered a major regulator of skeletal muscle metabolism during exercise. However, we previously showed that, although AMPK activity increases by 8–10‐fold during ∼120 min of exercise at ∼65% V˙O2peak in untrained individuals, there is no increase in these individuals after only 10 days of exercise training (longitudinal study). In a cross‐sectional study, we show that there is also a lack of activation of skeletal muscle AMPK during 120 min of cycling exercise at 65% V˙O2peak in endurance‐trained individuals. These findings indicate that AMPK is not an important regulator of exercise metabolism during 120 min of exercise at 65% V˙O2peak in endurance trained men. It is important that more energy is directed towards examining other potential regulators of exercise metabolism.
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Affiliation(s)
- Glenn K McConell
- Institute for Health and Sport, Victoria University, Melbourne, VIC, Australia.,Department of Physiology, University of Melbourne, Melbourne, VIC, Australia
| | - Glenn D Wadley
- Department of Physiology, University of Melbourne, Melbourne, VIC, Australia.,Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, VIC, Australia
| | | | - Kelly C Linden
- Department of Physiology, University of Melbourne, Melbourne, VIC, Australia.,Faculty of Science, Charles Sturt University, Albury, NSW, Australia
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4
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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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5
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Schnuck JK, Gould LM, Parry HA, Johnson MA, Gannon NP, Sunderland KL, Vaughan RA. Metabolic effects of physiological levels of caffeine in myotubes. J Physiol Biochem 2017; 74:35-45. [PMID: 29198059 DOI: 10.1007/s13105-017-0601-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 11/23/2017] [Indexed: 12/11/2022]
Abstract
Caffeine has been shown to stimulate multiple major regulators of cell energetics including AMP-activated protein kinase (AMPK) and Ca2+/calmodulin-dependent protein kinase II (CaMKII). Additionally, caffeine induces peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) and mitochondrial biogenesis. While caffeine enhances oxidative metabolism, experimental concentrations often exceed physiologically attainable concentrations through diet. This work measured the effects of low-level caffeine on cellular metabolism and gene expression in myotubes, as well as the dependence of caffeine's effects on the nuclear receptor peroxisome proliferator-activated receptor beta/delta (PPARβ/δ). C2C12 myotubes were treated with various doses of caffeine for up to 24 h. Gene and protein expression were measured via qRT-PCR and Western blot, respectively. Cellular metabolism was determined via oxygen consumption and extracellular acidification rate. Caffeine significantly induced regulators of mitochondrial biogenesis and oxidative metabolism. Mitochondrial staining was suppressed in PPARβ/δ-inhibited cells which was rescued by concurrent caffeine treatment. Caffeine-treated cells also displayed elevated peak oxidative metabolism which was partially abolished following PPARβ/δ inhibition. Similar to past observations, glucose uptake and GLUT4 content were elevated in caffeine-treated cells, however, glycolytic metabolism was unaltered following caffeine treatment. Physiological levels of caffeine appear to enhance cell metabolism through mechanisms partially dependent on PPARβ/δ.
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Affiliation(s)
- Jamie K Schnuck
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
- School of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Lacey M Gould
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Hailey A Parry
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
- School of Kinesiology, Auburn University, Auburn, AL, 36849, USA
| | - Michele A Johnson
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Nicholas P Gannon
- School of Medicine, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Kyle L Sunderland
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA
| | - Roger A Vaughan
- Department of Exercise Science, High Point University, One University Parkway, High Point, NC, 27268, USA.
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6
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Sylow L, Kleinert M, Richter EA, Jensen TE. Exercise-stimulated glucose uptake - regulation and implications for glycaemic control. Nat Rev Endocrinol 2017; 13:133-148. [PMID: 27739515 DOI: 10.1038/nrendo.2016.162] [Citation(s) in RCA: 257] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Skeletal muscle extracts glucose from the blood to maintain demand for carbohydrates as an energy source during exercise. Such uptake involves complex molecular signalling processes that are distinct from those activated by insulin. Exercise-stimulated glucose uptake is preserved in insulin-resistant muscle, emphasizing exercise as a therapeutic cornerstone among patients with metabolic diseases such as diabetes mellitus. Exercise increases uptake of glucose by up to 50-fold through the simultaneous stimulation of three key steps: delivery, transport across the muscle membrane and intracellular flux through metabolic processes (glycolysis and glucose oxidation). The available data suggest that no single signal transduction pathway can fully account for the regulation of any of these key steps, owing to redundancy in the signalling pathways that mediate glucose uptake to ensure maintenance of muscle energy supply during physical activity. Here, we review the molecular mechanisms that regulate the movement of glucose from the capillary bed into the muscle cell and discuss what is known about their integrated regulation during exercise. Novel developments within the field of mass spectrometry-based proteomics indicate that the known regulators of glucose uptake are only the tip of the iceberg. Consequently, many exciting discoveries clearly lie ahead.
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Affiliation(s)
- Lykke Sylow
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Maximilian Kleinert
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Erik A Richter
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Thomas E Jensen
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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7
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Cheng J, Zhang T, Ji H, Tao K, Guo J, Wei W. Functional characterization of AMP-activated protein kinase signaling in tumorigenesis. Biochim Biophys Acta Rev Cancer 2016; 1866:232-251. [PMID: 27681874 DOI: 10.1016/j.bbcan.2016.09.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 09/22/2016] [Accepted: 09/23/2016] [Indexed: 12/13/2022]
Abstract
AMP-activated protein kinase (AMPK) is a ubiquitously expressed metabolic sensor among various species. Specifically, cellular AMPK is phosphorylated and activated under certain stressful conditions, such as energy deprivation, in turn to activate diversified downstream substrates to modulate the adaptive changes and maintain metabolic homeostasis. Recently, emerging evidences have implicated the potential roles of AMPK signaling in tumor initiation and progression. Nevertheless, a comprehensive description on such topic is still in scarcity, especially in combination of its biochemical features with mouse modeling results to elucidate the physiological role of AMPK signaling in tumorigenesis. Hence, we performed this thorough review by summarizing the tumorigenic role of each component along the AMPK signaling, comprising of both its upstream and downstream effectors. Moreover, their functional interplay with the AMPK heterotrimer and exclusive efficacies in carcinogenesis were chiefly explained among genetically altered mice models. Importantly, the pharmaceutical investigations of AMPK relevant medications have also been highlighted. In summary, in this review, we not only elucidate the potential functions of AMPK signaling pathway in governing tumorigenesis, but also potentiate the future targeted strategy aiming for better treatment of aberrant metabolism-associated diseases, including cancer.
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Affiliation(s)
- Ji Cheng
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China; Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Tao Zhang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Hongbin Ji
- Key Laboratory of Systems Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, Shanghai 200031, People's Republic of China
| | - Kaixiong Tao
- Department of Gastrointestinal Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
| | - Jianping Guo
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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8
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IL-15 Mediates Mitochondrial Activity through a PPAR δ-Dependent-PPAR α-Independent Mechanism in Skeletal Muscle Cells. PPAR Res 2016; 2016:5465804. [PMID: 27738421 PMCID: PMC5050360 DOI: 10.1155/2016/5465804] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 08/01/2016] [Accepted: 08/21/2016] [Indexed: 11/17/2022] Open
Abstract
Molecular mediators of metabolic processes, to increase energy expenditure, have become a focus for therapies of obesity. The discovery of cytokines secreted from the skeletal muscle (SKM), termed "myokines," has garnered attention due to their positive effects on metabolic processes. Interleukin-15 (IL-15) is a myokine that has numerous positive metabolic effects and is linked to the PPAR family of mitochondrial regulators. Here, we aimed to determine the importance of PPARα and/or PPARδ as targets of IL-15 signaling. C2C12 SKM cells were differentiated for 6 days and treated every other day with IL-15 (100 ng/mL), a PPARα inhibitor (GW-6471), a PPARδ inhibitor (GSK-3787), or both IL-15 and the inhibitors. IL-15 increased mitochondrial activity and induced PPARα, PPARδ, PGC1α, PGC1β, UCP2, and Nrf1 expression. There was no effect of inhibiting PPARα, in combination with IL-15, on the aforementioned mRNA levels except for PGC1β and Nrf1. However, with PPARδ inhibition, IL-15 failed to induce the expression levels of PGC1α, PGC1β, UCP2, and Nrf1. Further, inhibition of PPARδ abolished IL-15 induced increases in citrate synthase activity, ATP production, and overall mitochondrial activity. IL-15 had no effects on mitochondrial biogenesis. Our data indicates that PPARδ activity is required for the beneficial metabolic effects of IL-15 signaling in SKM.
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9
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Egawa T, Ohno Y, Goto A, Sugiura T, Ohira Y, Yoshioka T, Hayashi T, Goto K. Caffeine Affects Myotube Size As Well As Regulates Protein Degradation and Protein Synthesis Pathways in C2C12 Skeletal Muscle Cells. JOURNAL OF CAFFEINE RESEARCH 2016. [DOI: 10.1089/jcr.2015.0034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Tatsuro Egawa
- Department of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Toyohashi, Japan
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Yoshitaka Ohno
- Laboratory of Physiology, School of Health Sciences, Toyohashi SOZO University, Toyohashi, Japan
| | - Ayumi Goto
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Takao Sugiura
- Department of Exercise and Sports Physiology, Faculty of Education, Yamaguchi University, Yamaguchi, Japan
| | - Yoshinobu Ohira
- Graduate School of Health and Sports Science, Doshisha University, Kyoto, Japan
| | | | - Tatsuya Hayashi
- Laboratory of Sports and Exercise Medicine, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Katsumasa Goto
- Department of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Toyohashi, Japan
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10
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Mul JD, Stanford KI, Hirshman MF, Goodyear LJ. Exercise and Regulation of Carbohydrate Metabolism. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 135:17-37. [PMID: 26477909 DOI: 10.1016/bs.pmbts.2015.07.020] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Carbohydrates are the preferred substrate for contracting skeletal muscles during high-intensity exercise and are also readily utilized during moderate intensity exercise. This use of carbohydrates during physical activity likely played an important role during the survival of early Homo sapiens, and genes and traits regulating physical activity, carbohydrate metabolism, and energy storage have undoubtedly been selected throughout evolution. In contrast to the life of early H. sapiens, modern lifestyles are predominantly sedentary. As a result, intake of excessive amounts of carbohydrates due to the easy and continuous accessibility to modern high-energy food and drinks has not only become unnecessary but also led to metabolic diseases in the face of physical inactivity. A resulting metabolic disease is type 2 diabetes, a complex endocrine disorder characterized by abnormally high concentrations of circulating glucose. This disease now affects millions of people worldwide. Exercise has beneficial effects to help control impaired glucose homeostasis with metabolic disease, and is a well-established tool to prevent and combat type 2 diabetes. This chapter focuses on the effects of exercise on carbohydrate metabolism in skeletal muscle and systemic glucose homeostasis. We will also focus on the molecular mechanisms that mediate the effects of exercise to increase glucose uptake in skeletal muscle. It is now well established that there are different proximal signaling pathways that mediate the effects of exercise and insulin on glucose uptake, and these distinct mechanisms are consistent with the ability of exercise to increase glucose uptake in the face of insulin resistance in people with type 2 diabetes. Ongoing research in this area is aimed at defining the precise mechanism by which exercise increases glucose uptake and insulin sensitivity and the types of exercise necessary for these important health benefits.
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Affiliation(s)
- Joram D Mul
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Kristin I Stanford
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Michael F Hirshman
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Laurie J Goodyear
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts, USA; Department of Medicine, Brigham, and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
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11
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Stanford KI, Goodyear LJ. Exercise and type 2 diabetes: molecular mechanisms regulating glucose uptake in skeletal muscle. ADVANCES IN PHYSIOLOGY EDUCATION 2014; 38:308-14. [PMID: 25434013 PMCID: PMC4315445 DOI: 10.1152/advan.00080.2014] [Citation(s) in RCA: 170] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Exercise is a well-established tool to prevent and combat type 2 diabetes. Exercise improves whole body metabolic health in people with type 2 diabetes, and adaptations to skeletal muscle are essential for this improvement. An acute bout of exercise increases skeletal muscle glucose uptake, while chronic exercise training improves mitochondrial function, increases mitochondrial biogenesis, and increases the expression of glucose transporter proteins and numerous metabolic genes. This review focuses on the molecular mechanisms that mediate the effects of exercise to increase glucose uptake in skeletal muscle.
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Affiliation(s)
- Kristin I Stanford
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Laurie J Goodyear
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
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12
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Abbott MJ, Turcotte LP. AMPK-α2 is involved in exercise training-induced adaptations in insulin-stimulated metabolism in skeletal muscle following high-fat diet. J Appl Physiol (1985) 2014; 117:869-79. [DOI: 10.1152/japplphysiol.01380.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
AMP-activated protein kinase (AMPK) has been studied extensively and postulated to be a target for the treatment and/or prevention of metabolic disorders such as insulin resistance. Exercise training has been deemed a beneficial treatment for obesity and insulin resistance. Furthermore, exercise is a feasible method to combat high-fat diet (HFD)-induced alterations in insulin sensitivity. The purpose of this study was to determine whether AMPK-α2 activity is required to gain beneficial effects of exercise training with high-fat feeding. Wild-type (WT) and AMPK-α2 dominant-negative (DN) male mice were fed standard diet (SD), underwent voluntary wheel running (TR), fed HFD, or trained with HFD (TR + HFD). By week 6, TR, irrespective of genotype, decreased blood glucose and increased citrate synthase activity in both diet groups and decreased insulin levels in HFD groups. Hindlimb perfusions were performed, and, in WT mice with SD, TR increased insulin-mediated palmitate uptake (76.7%) and oxidation (>2-fold). These training-induced changes were not observed in the DN mice. With HFD, TR decreased palmitate oxidation (61–64%) in both WT and DN and increased palmitate uptake (112%) in the WT with no effects on palmitate uptake in the DN. With SD, TR increased ERK1/2 and JNK1/2 phosphorylation, regardless of genotype. With HFD, TR reduced JNK1/2 phosphorylation, regardless of genotype, carnitine palmitoyltransferase 1 expression in WT, and CD36 expression in both DN and WT. These data suggest that low AMPK-α2 signaling disrupts, in part, the exercise training-induced adaptations in insulin-stimulated metabolism in skeletal muscle following HFD.
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Affiliation(s)
- Marcia J. Abbott
- Department of Biological Sciences, Human and Evolutionary Biology Section, Dana and David Dornsife College of Arts, Letters, and Sciences, University of Southern California, Los Angeles, California; and
- Crean College of Health and Behavioral Sciences, Chapman University, Orange, California
| | - Lorraine P. Turcotte
- Department of Biological Sciences, Human and Evolutionary Biology Section, Dana and David Dornsife College of Arts, Letters, and Sciences, University of Southern California, Los Angeles, California; and
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Jensen TE, Angin Y, Sylow L, Richter EA. Is contraction-stimulated glucose transport feedforward regulated by Ca2+? Exp Physiol 2014; 99:1562-8. [DOI: 10.1113/expphysiol.2014.081679] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Thomas E. Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports; University of Copenhagen; Denmark
| | - Yeliz Angin
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports; University of Copenhagen; Denmark
| | - Lykke Sylow
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports; University of Copenhagen; Denmark
| | - Erik A. Richter
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports; University of Copenhagen; Denmark
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14
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Contraction-stimulated glucose transport in muscle is controlled by AMPK and mechanical stress but not sarcoplasmatic reticulum Ca(2+) release. Mol Metab 2014; 3:742-53. [PMID: 25353002 PMCID: PMC4209358 DOI: 10.1016/j.molmet.2014.07.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/11/2014] [Accepted: 07/16/2014] [Indexed: 12/25/2022] Open
Abstract
Understanding how muscle contraction orchestrates insulin-independent muscle glucose transport may enable development of hyperglycemia-treating drugs. The prevailing concept implicates Ca2+ as a key feed forward regulator of glucose transport with secondary fine-tuning by metabolic feedback signals through proteins such as AMPK. Here, we demonstrate in incubated mouse muscle that Ca2+ release is neither sufficient nor strictly necessary to increase glucose transport. Rather, the glucose transport response is associated with metabolic feedback signals through AMPK, and mechanical stress-activated signals. Furthermore, artificial stimulation of AMPK combined with passive stretch of muscle is additive and sufficient to elicit the full contraction glucose transport response. These results suggest that ATP-turnover and mechanical stress feedback are sufficient to fully increase glucose transport during muscle contraction, and call for a major reconsideration of the established Ca2+ centric paradigm.
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Angin Y, Schwenk RW, Nergiz-Unal R, Hoebers N, Heemskerk JWM, Kuijpers MJ, Coumans WA, van Zandvoort MAMJ, Bonen A, Neumann D, Glatz JFC, Luiken JJFP. Calcium signaling recruits substrate transporters GLUT4 and CD36 to the sarcolemma without increasing cardiac substrate uptake. Am J Physiol Endocrinol Metab 2014; 307:E225-36. [PMID: 24895286 DOI: 10.1152/ajpendo.00655.2013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Activation of AMP-activated protein kinase (AMPK) in cardiomyocytes induces translocation of glucose transporter GLUT4 and long-chain fatty acid (LCFA) transporter CD36 from endosomal stores to the sarcolemma to enhance glucose and LCFA uptake, respectively. Ca(2+)/calmodulin-activated kinase kinase-β (CaMKKβ) has been positioned directly upstream of AMPK. However, it is unknown whether acute increases in [Ca(2+)]i stimulate translocation of GLUT4 and CD36 and uptake of glucose and LCFA or whether Ca(2+) signaling converges with AMPK signaling to exert these actions. Therefore, we studied the interplay between Ca(2+) and AMPK signaling in regulation of cardiomyocyte substrate uptake. Exposure of primary cardiomyocytes to inhibitors or activators of Ca(2+) signaling affected neither AMPK-Thr(172) phosphorylation nor basal and AMPK-mediated glucose and LCFA uptake. Despite their lack of an effect on substrate uptake, Ca(2+) signaling activators induced GLUT4 and CD36 translocation. In contrast, AMPK activators stimulated GLUT4/CD36 translocation as well as glucose/LCFA uptake. When cardiomyocytes were cotreated with Ca(2+) signaling and AMPK activators, Ca(2+) signaling activators further enhanced AMPK-induced glucose/LCFA uptake. In conclusion, Ca(2+) signaling shows no involvement in AMPK-induced GLUT4/CD36 translocation and substrate uptake but elicits transporter translocation via a separate pathway requiring CaMKKβ/CaMKs. Ca(2+)-induced transporter translocation by itself appears to be ineffective to increase substrate uptake but requires additional AMPK activation to effectuate transporter translocation into increased substrate uptake. Ca(2+)-induced transporter translocation might be crucial under excessive cardiac stress conditions that require supraphysiological energy demands. Alternatively, Ca(2+) signaling might prepare the heart for substrate uptake during physiological contraction by inducing transporter translocation.
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Affiliation(s)
| | | | | | | | | | | | | | - Marc A M J van Zandvoort
- Molecular Cell Biology, School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
| | - Arend Bonen
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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16
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Lantier L, Fentz J, Mounier R, Leclerc J, Treebak JT, Pehmøller C, Sanz N, Sakakibara I, Saint‐Amand E, Rimbaud S, Maire P, Marette A, Ventura‐Clapier R, Ferry A, Wojtaszewski JFP, Foretz M, Viollet B. AMPK controls exercise endurance, mitochondrial oxidative capacity, and skeletal muscle integrity. FASEB J 2014; 28:3211-24. [DOI: 10.1096/fj.14-250449] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Louise Lantier
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité (U)1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris Descartes, Sorbonne Paris CitéParisFrance
| | - Joachim Fentz
- Section of Molecular PhysiologyThe August Krogh CentreDepartment of Nutrition, Exercise, and SportsUniversity of CopenhagenCopenhagenDenmark
| | - Rémi Mounier
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité (U)1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris Descartes, Sorbonne Paris CitéParisFrance
| | - Jocelyne Leclerc
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité (U)1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris Descartes, Sorbonne Paris CitéParisFrance
| | - Jonas T. Treebak
- Section of Molecular PhysiologyThe August Krogh CentreDepartment of Nutrition, Exercise, and SportsUniversity of CopenhagenCopenhagenDenmark
| | - Christian Pehmøller
- Section of Molecular PhysiologyThe August Krogh CentreDepartment of Nutrition, Exercise, and SportsUniversity of CopenhagenCopenhagenDenmark
| | - Nieves Sanz
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité (U)1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris Descartes, Sorbonne Paris CitéParisFrance
| | - Iori Sakakibara
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité (U)1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris Descartes, Sorbonne Paris CitéParisFrance
| | | | | | - Pascal Maire
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité (U)1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris Descartes, Sorbonne Paris CitéParisFrance
| | | | | | - Arnaud Ferry
- Université Paris Descartes, Sorbonne Paris CitéParisFrance
- Institut de Myologie, INSERM, U974, CNRS UMR 7215Université Pierre et Marie CurieParisFrance
| | - Jørgen F. P. Wojtaszewski
- Section of Molecular PhysiologyThe August Krogh CentreDepartment of Nutrition, Exercise, and SportsUniversity of CopenhagenCopenhagenDenmark
| | - Marc Foretz
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité (U)1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris Descartes, Sorbonne Paris CitéParisFrance
| | - Benoit Viollet
- Institut National de la Santé et de la Recherche Médicale (INSERM), Unité (U)1016Institut CochinParisFrance
- Centre National de la Recherche Scientifique (CNRS)Unité Mixte de Recherche (UMR)8104ParisFrance
- Université Paris Descartes, Sorbonne Paris CitéParisFrance
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Egawa T, Tsuda S, Oshima R, Goto K, Hayashi T. Activation of 5′AMP-activated protein kinase in skeletal muscle by exercise and phytochemicals. JOURNAL OF PHYSICAL FITNESS AND SPORTS MEDICINE 2014. [DOI: 10.7600/jpfsm.3.55] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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Abstract
Glucose is an important fuel for contracting muscle, and normal glucose metabolism is vital for health. Glucose enters the muscle cell via facilitated diffusion through the GLUT4 glucose transporter which translocates from intracellular storage depots to the plasma membrane and T-tubules upon muscle contraction. Here we discuss the current understanding of how exercise-induced muscle glucose uptake is regulated. We briefly discuss the role of glucose supply and metabolism and concentrate on GLUT4 translocation and the molecular signaling that sets this in motion during muscle contractions. Contraction-induced molecular signaling is complex and involves a variety of signaling molecules including AMPK, Ca(2+), and NOS in the proximal part of the signaling cascade as well as GTPases, Rab, and SNARE proteins and cytoskeletal components in the distal part. While acute regulation of muscle glucose uptake relies on GLUT4 translocation, glucose uptake also depends on muscle GLUT4 expression which is increased following exercise. AMPK and CaMKII are key signaling kinases that appear to regulate GLUT4 expression via the HDAC4/5-MEF2 axis and MEF2-GEF interactions resulting in nuclear export of HDAC4/5 in turn leading to histone hyperacetylation on the GLUT4 promoter and increased GLUT4 transcription. Exercise training is the most potent stimulus to increase skeletal muscle GLUT4 expression, an effect that may partly contribute to improved insulin action and glucose disposal and enhanced muscle glycogen storage following exercise training in health and disease.
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Affiliation(s)
- Erik A Richter
- Molecular Physiology Group, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
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Sarvas JL, Khaper N, Lees SJ. The IL-6 Paradox: Context Dependent Interplay of SOCS3 and AMPK. ACTA ACUST UNITED AC 2013; Suppl 13. [PMID: 24244888 DOI: 10.4172/2155-6156.s13-003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Insulin resistance is the principle step towards the progression of type 2 diabetes, and has been linked to increased circulating levels of cytokines, leading to chronic low-grade inflammation. Specifically, in chronic disease states increased IL-6 is thought to play a critical role in the regulation of insulin resistance in the peripheral tissues, and has been used as a marker of insulin resistance. There is also an endogenous up-regulation of IL-6 in response to exercise, which has been linked to improved insulin sensitivity. This leads to the question "how can elevated IL-6 lead to the development of insulin resistance, and yet also lead to increased insulin sensitivity?" Resolving the dual role of IL-6 in regulating insulin resistance/sensitivity is critical to the development of potential therapeutic interventions. This review summarizes the literature on the seemingly paradoxical role of elevated IL-6 on insulin signalling, including the activation of AMPK and the involvement of leptin and SOCS3.
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Turcotte LP, Abbott MJ. Contraction-induced signaling: evidence of convergent cascades in the regulation of muscle fatty acid metabolism. Can J Physiol Pharmacol 2012. [PMID: 23181271 DOI: 10.1139/y2012-124] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The regulation of fatty acid utilization during muscle contraction and exercise remains to be fully elucidated. Evidence suggests that the metabolic responses of skeletal muscle induced by the contraction-induced changes in energy demand are mediated by the activation of a multitude of intracellular signaling cascades. This review addresses the roles played by 3 intracellular signaling cascades of interest in the regulation of fatty acid uptake and oxidation in contracting skeletal muscle; namely, the AMP-activated protein kinase (AMPK), calcium/calmodulin-dependent protein kinases (CaMKs), and the extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling cascades. Data delineating the potential role of AMPK in cross-talk with CaMKII, CaMK kinase (CaMKK), and ERK1/2 are presented. Collectively, data show that in perfused rodent muscle, regulation of fatty acid uptake and oxidation occurs via (i) CaMKII signaling via both AMPK-dependent and -independent cascades, (ii) CaMKK signaling via both AMPK-dependent and -independent cascades, (iii) AMPK signaling in a time- and intensity-dependent manner, and (iv) ERK1/2 signaling in an intensity-dependent manner.
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Affiliation(s)
- Lorraine P Turcotte
- Department of Biological Sciences, Dana and David Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089-0652, USA.
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Abbott MJ, Constantinescu S, Turcotte LP. AMP-activated protein kinase α2 is an essential signal in the regulation of insulin-stimulated fatty acid uptake in control-fed and high-fat-fed mice. Exp Physiol 2012; 97:603-17. [DOI: 10.1113/expphysiol.2012.064402] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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