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Kwak SE, Zheng A, Arias EB, Wang H, Pan X, Yue Y, Duan D, Cartee GD. A novel genetic model provides a unique perspective on the relationship between postexercise glycogen concentration and increases in the abundance of key metabolic proteins after acute exercise. PLoS One 2024; 19:e0295964. [PMID: 38289946 PMCID: PMC10826964 DOI: 10.1371/journal.pone.0295964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 12/04/2023] [Indexed: 02/01/2024] Open
Abstract
Some acute exercise effects are influenced by postexercise (PEX) diet, and these diet-effects are attributed to differential glycogen resynthesis. However, this idea is challenging to test rigorously. Therefore, we devised a novel genetic model to modify muscle glycogen synthase 1 (GS1) expression in rat skeletal muscle with an adeno-associated virus (AAV) short hairpin RNA knockdown vector targeting GS1 (shRNA-GS1). Contralateral muscles were injected with scrambled shRNA (shRNA-Scr). Muscles from exercised (2-hour-swim) and time-matched sedentary (Sed) rats were collected immediately postexercise (IPEX), 5-hours-PEX (5hPEX), or 9-hours-PEX (9hPEX). Rats in 5hPEX and 9hPEX experiments were refed (RF) or not-refed (NRF) chow. Muscles were analyzed for glycogen, abundance of metabolic proteins (pyruvate dehydrogenase kinase 4, PDK4; peroxisome proliferator-activated receptor γ coactivator-1α, PGC1α; hexokinase II, HKII; glucose transporter 4, GLUT4), AMP-activated protein kinase phosphorylation (pAMPK), and glycogen metabolism-related enzymes (glycogen phosphorylase, PYGM; glycogen debranching enzyme, AGL; glycogen branching enzyme, GBE1). shRNA-GS1 versus paired shRNA-Scr muscles had markedly lower GS1 abundance. IPEX versus Sed rats had lower glycogen and greater pAMPK, and neither of these IPEX-values differed for shRNA-GS1 versus paired shRNA-Scr muscles. IPEX versus Sed groups did not differ for abundance of metabolic proteins, regardless of GS1 knockdown. Glycogen in RF-rats was lower for shRNA-GS1 versus paired shRNA-Scr muscles at both 5hPEX and 9hPEX. HKII protein abundance was greater for 5hPEX versus Sed groups, regardless of GS1 knockdown or diet, and despite differing glycogen levels. At 9hPEX, shRNA-GS1 versus paired shRNA-Scr muscles had greater PDK4 and PGC1α abundance within each diet group. However, the magnitude of PDK4 or PGC1α changes was similar in each diet group regardless of GS1 knockdown although glycogen differed between paired muscles only in RF-rats. In summary, we established a novel genetic approach to investigate the relationship between muscle glycogen and other exercise effects. Our results suggest that exercise-effects on abundance of several metabolic proteins did not uniformly correspond to differences in postexercise glycogen.
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Affiliation(s)
- Seong Eun Kwak
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Amy Zheng
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Edward B. Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Xiufang Pan
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, United States of America
| | - Yongping Yue
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, United States of America
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, United States of America
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, Missouri, United States of America
- Department of Neurology, School of Medicine, University of Missouri, Columbia, Missouri, United States of America
- Department of Biomedical, Biological & Chemical Engineering, College of Engineering, University of Missouri, Columbia, Missouri, United States of America
| | - Gregory D. Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States of America
- Institute of Gerontology, University of Michigan, Ann Arbor, Michigan, United States of America
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2
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Podlogar T, Shad BJ, Seabright AP, Odell OJ, Lord SO, Civil R, Salgueiro RB, Shepherd EL, Lalor PF, Elhassan YS, Lai YC, Rowlands DS, Wallis GA. Postexercise muscle glycogen synthesis with glucose, galactose, and combined galactose-glucose ingestion. Am J Physiol Endocrinol Metab 2023; 325:E672-E681. [PMID: 37850935 PMCID: PMC10864004 DOI: 10.1152/ajpendo.00127.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/13/2023] [Accepted: 10/13/2023] [Indexed: 10/19/2023]
Abstract
Ingested galactose can enhance postexercise liver glycogen repletion when combined with glucose but effects on muscle glycogen synthesis are unknown. In this double-blind randomized study participants [7 men and 2 women; V̇o2max: 51.1 (8.7) mL·kg-1·min-1] completed three trials of exhaustive cycling exercise followed by a 4-h recovery period, during which carbohydrates were ingested at the rate of 1.2 g·kg-1·h-1 comprising glucose (GLU), galactose (GAL) or galactose + glucose (GAL + GLU; 1:2 ratio). The increase in vastus lateralis skeletal-muscle glycogen concentration during recovery was higher with GLU relative to GAL + GLU [contrast: +50 mmol·(kg DM)-1; 95%CL 10, 89; P = 0.021] and GAL [+46 mmol·(kg DM)-1; 95%CL 8, 84; P = 0.024] with no difference between GAL + GLU and GAL [-3 mmol·(kg DM)-1; 95%CL -44, 37; P = 0.843]. Plasma glucose concentration in GLU was not significantly different vs. GAL + GLU (+ 0.41 mmol·L-1; 95%CL 0.13, 0.94) but was significantly lower than GAL (-0.75 mmol·L-1; 95%CL -1.34, -0.17) and also lower in GAL vs. GAL + GLU (-1.16 mmol·-1; 95%CL -1.80, -0.53). Plasma insulin was higher in GLU + GAL and GLU compared with GAL but not different between GLU + GAL and GLU. Plasma galactose concentration was higher in GAL compared with GLU (3.35 mmol·L-1; 95%CL 3.07, 3.63) and GAL + GLU (3.22 mmol·L-1; 95%CL 3.54, 2.90) with no difference between GLU + GAL (0.13 mmol·L-1; 95%CL -0.11, 0.37) and GLU. Compared with galactose or a galactose + glucose blend, glucose feeding was more effective in postexercise muscle glycogen synthesis. Comparable muscle glycogen synthesis was observed with galactose-glucose coingestion and exclusive galactose-only ingestion.NEW & NOTEWORTHY Postexercise galactose-glucose coingestion or exclusive galactose-only ingestion resulted in a lower rate of skeletal-muscle glycogen replenishment compared with exclusive glucose-only ingestion. Comparable muscle glycogen synthesis was observed with galactose-glucose coingestion and exclusive galactose-only ingestion.
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Affiliation(s)
- Tim Podlogar
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Brandon J Shad
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Alex P Seabright
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Oliver J Odell
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Samuel O Lord
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Rita Civil
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Rafael B Salgueiro
- Department of Physiology and Biophysics, University of Sao Paulo, Sao Paulo, Brazil
| | - Emma L Shepherd
- Centre for Liver and Gastroenterology Research and National Institute for Health Research Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Patricia F Lalor
- Centre for Liver and Gastroenterology Research and National Institute for Health Research Birmingham Biomedical Research Centre, Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Yasir S Elhassan
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, United Kingdom
| | - Yu-Chiang Lai
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - David S Rowlands
- School of Sport, Exercise and Nutrition, Massey University, Auckland, New Zealand
| | - Gareth A Wallis
- School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
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3
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Gutowska I, Maruszewska A, Skórka-Majewicz M, Kempińska-Podhorodecka A, Kolasa A, Wszołek A, Baranowska-Bosiacka I, Żwierełło W. Fluoride as a Potential Repressor of Glycogen Metabolism in Skeletal Muscle Cell Line CCL136. Molecules 2023; 28:6065. [PMID: 37630316 PMCID: PMC10459804 DOI: 10.3390/molecules28166065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 07/30/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
The exposure of humans to fluorine is connected with its presence in the air, food and water. It is well known that fluorides even at a low concentration but with long time exposure accumulate in the body and lead to numerous metabolic disorders. Fluoride is recognised as a factor modulating the energy metabolism of cells. This interaction is of particular importance in muscle cells, which are cells with high metabolic activity related to the metabolism of glucose and glycogen. In someone suffering from chronic fluoride poisoning, frequent symptoms are chronic fatigue not relieved by extra sleep or rest, muscular weakness, muscle spasms, involuntary twitching. The aim of this study was to examine the effect of fluorine at concentrations determined in blood of people environmentally exposed to fluorides on activity and expression of enzymes taking part in metabolism of muscle glycogen. CCL136 cells were cultured under standard conditions with the addition of NaF. The amount of ATP produced by the cells was determined using the HPLC method, the amount and expression of genes responsible for glycogen metabolism using WB and RT PCR methods and the amount of glycogen in cells using the fluorimetric and PAS methods. It has been shown that in CCL136 cells exposed to 1, 3 and 10 μM NaF there is a change in the energy state and expression pattern of enzymes involved in the synthesis and breakdown of glycogen. It was observed that NaF caused a decrease in ATP content in CCL136 cells. Fluoride exposure also increased glycogen deposition. These changes were accompanied by a decrease in gene expression and the level of enzymatic proteins related to glycogen metabolism: glycogen synthase, glycogen synthase kinase and glycogen phosphorylase. The results obtained shed new light on the molecular mechanisms by which fluoride acts as an environmental toxin.
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Affiliation(s)
- Izabela Gutowska
- Department of Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland; (M.S.-M.); (W.Ż.)
| | - Agnieszka Maruszewska
- Department of Physiology and Biochemistry, Institute of Biology, University of Szczecin, 70-453 Szczecin, Poland; (A.M.); (A.W.)
| | - Marta Skórka-Majewicz
- Department of Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland; (M.S.-M.); (W.Ż.)
| | | | - Agnieszka Kolasa
- Department of Histology and Embriology, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland;
| | - Agata Wszołek
- Department of Physiology and Biochemistry, Institute of Biology, University of Szczecin, 70-453 Szczecin, Poland; (A.M.); (A.W.)
| | | | - Wojciech Żwierełło
- Department of Medical Chemistry, Pomeranian Medical University in Szczecin, 70-111 Szczecin, Poland; (M.S.-M.); (W.Ż.)
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Guo H, Wu H, Li Z. The Pathogenesis of Diabetes. Int J Mol Sci 2023; 24:ijms24086978. [PMID: 37108143 PMCID: PMC10139109 DOI: 10.3390/ijms24086978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/30/2023] [Accepted: 04/05/2023] [Indexed: 04/29/2023] Open
Abstract
Diabetes is the most common metabolic disorder, with an extremely serious effect on health systems worldwide. It has become a severe, chronic, non-communicable disease after cardio-cerebrovascular diseases. Currently, 90% of diabetic patients suffer from type 2 diabetes. Hyperglycemia is the main hallmark of diabetes. The function of pancreatic cells gradually declines before the onset of clinical hyperglycemia. Understanding the molecular processes involved in the development of diabetes can provide clinical care with much-needed updates. This review provides the current global state of diabetes, the mechanisms involved in glucose homeostasis and diabetic insulin resistance, and the long-chain non-coding RNA (lncRNA) associated with diabetes.
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Affiliation(s)
- Huiqin Guo
- Institute of Biotechnology, The Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China
| | - Haili Wu
- College of Life Science, Shanxi University, Taiyuan 030006, China
| | - Zhuoyu Li
- Institute of Biotechnology, The Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan 030006, China
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5
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Schmid S, Heim-Kupr B, Pérez-Schindler J, Mansingh S, Beer M, Mittal N, Ehrenfeuchter N, Handschin C. PGC-1β modulates catabolism and fiber atrophy in the fasting-response of specific skeletal muscle beds. Mol Metab 2022; 66:101643. [PMID: 36400401 PMCID: PMC9723918 DOI: 10.1016/j.molmet.2022.101643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 11/14/2022] [Accepted: 11/14/2022] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE Skeletal muscle is a pivotal organ for the coordination of systemic metabolism, constituting one of the largest storage site for glucose, lipids and amino acids. Tight temporal orchestration of protein breakdown in times of fasting has to be balanced with preservation of muscle mass and function. However, the molecular mechanisms that control the fasting response in muscle are poorly understood. METHODS We now have identified a role for the peroxisome proliferator-activated receptor γ coactivator 1β (PGC-1β) in the regulation of catabolic pathways in this context in muscle-specific loss-of-function mouse models. RESULTS Muscle-specific knockouts for PGC-1β experience mitigated muscle atrophy in fasting, linked to reduced expression of myostatin, atrogenes, activation of AMP-dependent protein kinase (AMPK) and other energy deprivation signaling pathways. At least in part, the muscle fasting response is modulated by a negative effect of PGC-1β on the nuclear factor of activated T-cells 1 (NFATC1). CONCLUSIONS Collectively, these data highlight the complex regulation of muscle metabolism and reveal a new role for muscle PGC-1β in the control of proteostasis in fasting.
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Affiliation(s)
- Svenia Schmid
- Biozentrum, University of Basel, Spitalstrasse 41, CH-4056 Basel, Switzerland
| | - Barbara Heim-Kupr
- Biozentrum, University of Basel, Spitalstrasse 41, CH-4056 Basel, Switzerland
| | | | - Shivani Mansingh
- Biozentrum, University of Basel, Spitalstrasse 41, CH-4056 Basel, Switzerland
| | - Markus Beer
- Biozentrum, University of Basel, Spitalstrasse 41, CH-4056 Basel, Switzerland
| | - Nitish Mittal
- Biozentrum, University of Basel, Spitalstrasse 41, CH-4056 Basel, Switzerland
| | | | - Christoph Handschin
- Biozentrum, University of Basel, Spitalstrasse 41, CH-4056 Basel, Switzerland.
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6
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Margolis LM, Carrigan CT, Murphy NE, DiBella MN, Wilson MA, Whitney CC, Howard EE, Pasiakos SM, Rivas DA. Carbohydrate intake in recovery from aerobic exercise differentiates skeletal muscle microRNA expression. Am J Physiol Endocrinol Metab 2022; 323:E435-E447. [PMID: 36044708 PMCID: PMC9639755 DOI: 10.1152/ajpendo.00110.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/26/2022] [Accepted: 08/30/2022] [Indexed: 11/22/2022]
Abstract
Posttranscriptional regulation by microRNA (miRNA) facilitates exercise and diet-induced skeletal muscle adaptations. However, the impact of diet on miRNA expression during postexercise recovery remains unclear. The objective of this study was to examine the effects of consuming carbohydrate or a nutrient-free control on skeletal muscle miRNA expression during 3 h of recovery from aerobic exercise. Using a randomized, crossover design, seven men (means ± SD, age: 21 ± 3 yr; body mass: 83 ± 13 kg; V̇o2peak: 43 ± 2 mL/kg/min) completed two-cycle ergometry glycogen depletion trials followed by 3 h of recovery while consuming either carbohydrate (CHO: 1 g/kg/h) or control (CON: nutrient free). Muscle biopsy samples were obtained under resting fasted conditions at baseline and at the end of the 3-h recovery (REC) period. miRNA expression was determined using unbiased RT-qPCR microarray analysis. Trials were separated by 7 days. Twenty-five miRNAs were different (P < 0.05) between CHO and CON at REC, with Let7i-5p and miR-195-5p being the most predictive of treatment. In vitro overexpression of Let7i-5p and miR-195-p5 in C2C12 skeletal muscle cells decreased (P < 0.05) the expression of protein breakdown (Foxo1, Trim63, Casp3, and Atf4) genes, ubiquitylation, and protease enzyme activity compared with control. Energy sensing (Prkaa1 and Prkab1) and glycolysis (Gsy1 and Gsk3b) genes were lower (P < 0.05) with Let7i-5p overexpression compared with miR-195-5p and control. Fat metabolism (Cpt1a, Scd1, and Hadha) genes were lower (P < 0.05) in miR-195-5p than in control. These data indicate that consuming CHO after aerobic exercise alters miRNA profiles compared with CON, and these differences may govern mechanisms facilitating muscle recovery.NEW & NOTEWORTHY Results provide novel insight into effects of carbohydrate intake on the expression of skeletal muscle microRNA during early recovery from aerobic exercise and reveal that Let7i-5p and miR-195-5p are important regulators of skeletal muscle protein breakdown to aid in facilitating muscle recovery.
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Affiliation(s)
- Lee M Margolis
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Christopher T Carrigan
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Nancy E Murphy
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Marissa N DiBella
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
- Oak Ridge Institute of Science and Education, Belcamp, Maryland
| | - Marques A Wilson
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Claire C Whitney
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Emily E Howard
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Stefan M Pasiakos
- Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Donato A Rivas
- Nutrition, Exercise Physiology and Sarcopenia Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts
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7
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McCorvie TJ, Loria PM, Tu M, Han S, Shrestha L, Froese DS, Ferreira IM, Berg AP, Yue WW. Molecular basis for the regulation of human glycogen synthase by phosphorylation and glucose-6-phosphate. Nat Struct Mol Biol 2022; 29:628-638. [PMID: 35835870 PMCID: PMC9287172 DOI: 10.1038/s41594-022-00799-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 05/02/2022] [Indexed: 11/17/2022]
Abstract
Glycogen synthase (GYS1) is the central enzyme in muscle glycogen biosynthesis. GYS1 activity is inhibited by phosphorylation of its amino (N) and carboxyl (C) termini, which is relieved by allosteric activation of glucose-6-phosphate (Glc6P). We present cryo-EM structures at 3.0-4.0 Å resolution of phosphorylated human GYS1, in complex with a minimal interacting region of glycogenin, in the inhibited, activated and catalytically competent states. Phosphorylations of specific terminal residues are sensed by different arginine clusters, locking the GYS1 tetramer in an inhibited state via intersubunit interactions. The Glc6P activator promotes conformational change by disrupting these interactions and increases the flexibility of GYS1, such that it is poised to adopt a catalytically competent state when the sugar donor UDP-glucose (UDP-glc) binds. We also identify an inhibited-like conformation that has not transitioned into the activated state, in which the locking interaction of phosphorylation with the arginine cluster impedes subsequent conformational changes due to Glc6P binding. Our results address longstanding questions regarding the mechanism of human GYS1 regulation.
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Affiliation(s)
- Thomas J McCorvie
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Biosciences Institute, The Medical School, Newcastle University, Newcastle upon Tyne, UK
| | - Paula M Loria
- Discovery Sciences, Worldwide Research and Development, Pfizer Inc., Groton, CT, USA
| | - Meihua Tu
- Medicine Design, Worldwide Research and Development, Pfizer Inc., Cambridge, MA, USA
| | - Seungil Han
- Discovery Sciences, Worldwide Research and Development, Pfizer Inc., Groton, CT, USA
| | - Leela Shrestha
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - D Sean Froese
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, University of Zürich, Zürich, Switzerland
| | - Igor M Ferreira
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Allison P Berg
- Rare Disease Research Unit, Worldwide Research and Development, Pfizer Inc., Cambridge, MA, USA.
| | - Wyatt W Yue
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
- Biosciences Institute, The Medical School, Newcastle University, Newcastle upon Tyne, UK.
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8
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Alam MB, Ra JS, Lim JY, Song BR, Javed A, Lee SH. Lariciresinol Displays Anti-Diabetic Activity through Inhibition of α-Glucosidase and Activation and Enhancement of Insulin Signaling. Mol Nutr Food Res 2022; 66:e2100751. [PMID: 35490401 DOI: 10.1002/mnfr.202100751] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 03/09/2022] [Indexed: 12/14/2022]
Abstract
SCOPE The aim of this study is to investigate the antidiabetic effect of lariciresinol (LSR) in C2C12 myotubes and streptozotocin (STZ)-induced diabetic mice. METHODS AND RESULTS To investigate antidiabetic potential of LSR, α-glucosidase inhibitory assay, molecular docking, glucose uptake assay, western blot assay on antidiabetic biomarkers are performed. STZ-induced diabetic model is used for in vivo study by calculating oral glucose tolerance test, histochemical examination, and glycogen assay. LSR inhibits α-glucosidase activity with an IC50 value of 6.97 ± 0.37 µM and acts as a competitive inhibitor with an inhibitory constant (Ki) value of 0.046 µM. In C2C12 cells, LSR activates insulin signaling leading to glucose transporter 4 (GLUT4) translocation and augmented glucose uptake. Furthermore, in Streptozotocin (STZ)-treated diabetic mice, 3 weeks of oral LSR administration (10 mg kg-1 ) considerably decrease blood glucose levels, while increasing insulin levels in an oral glucose tolerance test, improve pancreatic islet size, increase GLUT4 expression, and significantly enhance insulin signaling in skeletal muscle. LSR treatment also activates glycogen synthase kinase 3β (GSK-3β) resulting in improved glycogen content. CONCLUSION The findings indicate a potential usefulness for oral LSR in the management and prevention of diabetes by enhancing glucose homeostasis.
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Affiliation(s)
- Md Badrul Alam
- Department of Food Science and Biotechnology, Graduate School, Kyungpook National University, Daegu, 41566, Republic of Korea.,Food and Bio-Industry Research Institute, Inner Beauty/Anti-Aging Center, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Jeong-Sic Ra
- Department of Food Science and Biotechnology, Graduate School, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Ji-Young Lim
- Department of Food Science and Biotechnology, Graduate School, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Bo-Rim Song
- Department of Food Science and Biotechnology, Graduate School, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Ahsan Javed
- Department of Food Science and Biotechnology, Graduate School, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - Sang-Han Lee
- Department of Food Science and Biotechnology, Graduate School, Kyungpook National University, Daegu, 41566, Republic of Korea.,Food and Bio-Industry Research Institute, Inner Beauty/Anti-Aging Center, Kyungpook National University, Daegu, 41566, Republic of Korea
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9
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de Melo Madureira ÁN, de Oliveira JRS, de Menezes Lima VL. The Role of IL-6 Released During Exercise to Insulin Sensitivity and Muscle Hypertrophy. Mini Rev Med Chem 2022; 22:2419-2428. [PMID: 35264090 DOI: 10.2174/1389557522666220309161245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/25/2021] [Accepted: 01/27/2022] [Indexed: 11/22/2022]
Abstract
Interleukin-6 (IL-6) influences both inflammatory response and anti-inflammatory processes. This cytokine can be released by the exercising skeletal muscle, which characterizes it as a myokine. Unlike what is observed in inflammation, IL-6 produced by skeletal muscle is not preceded by the release of other pro-inflammatory cytokines, but is seems to be dependent on the lactate produced during exercise, thus causing different effects from those of seen in inflammatory state. After binding to its receptor, myokine IL-6 activates the PI3K-Akt pathway. One consequence of this upregulation is the potentiation of insulin signaling, which enhances insulin sensitivity. IL-6 increases GLUT-4 vesicle mobilization to muscle cell periphery, increasing the glucose transport into the cell, and also glycogen synthesis. Muscle glycogen provides energy for the ATP resynthesis, and regulates Ca2+ release by the sarcoplasmic reticulum, influencing muscle contraction, and, hence, muscle function by multiple pathways. Another implication for the upregulation of PI3K-Akt pathway is the activation of mTORC1, which regulates mRNA translational efficiency by regulating translation machinery, and translational capacity by inducing ribosomal biogenesis. Thus, IL-6 may contribute for skeletal muscle hypertrophy and function by increasing contractile protein synthesis.
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Affiliation(s)
- Álvaro Nóbrega de Melo Madureira
- Laboratory of Lipids and Application of Biomolecules to Prevalent and Neglected Diseases (LAB-DPN), Department of Biochemistry, Federal University of Pernambuco (UFPE)
| | - João Ricardhis Saturnino de Oliveira
- Laboratory of Lipids and Application of Biomolecules to Prevalent and Neglected Diseases (LAB-DPN), Department of Biochemistry, Federal University of Pernambuco (UFPE)
| | - Vera Lúcia de Menezes Lima
- Laboratory of Lipids and Application of Biomolecules to Prevalent and Neglected Diseases (LAB-DPN), Department of Biochemistry, Federal University of Pernambuco (UFPE)
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10
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Edwards SJ, Shad BJ, Marshall RN, Morgan PT, Wallis GA, Breen L. Short-term step reduction reduces CS activity without altering skeletal muscle markers of oxidative metabolism or insulin-mediated signalling in young males. J Appl Physiol (1985) 2021; 131:1653-1662. [PMID: 34734783 PMCID: PMC8714983 DOI: 10.1152/japplphysiol.00650.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mitochondria are critical to skeletal muscle contractile function and metabolic health. Short-term periods of step reduction (SR) are associated with alterations in muscle protein turnover and mass. However, the effects of SR on mitochondrial metabolism/muscle oxidative metabolism and insulin-mediated signaling are unclear. We tested the hypothesis that the total and/or phosphorylated protein content of key skeletal muscle markers of mitochondrial/oxidative metabolism, and insulin-mediated signaling would be altered over 7 days of SR in young healthy males. Eleven, healthy, recreationally active males (means ± SE, age: 22 ± 1 yr, BMI: 23.4 ± 0.7 kg·m2) underwent a 7-day period of SR. Immediately before and following SR, fasted-state muscle biopsy samples were acquired and analyzed for the assessment of total and phosphorylated protein content of key markers of mitochondrial/oxidative metabolism and insulin-mediated signaling. Daily step count was significantly reduced during the SR intervention (13,054 ± 833 to 1,192 ± 99 steps·day−1, P < 0.001). Following SR, there was a significant decline in maximal citrate synthase activity (fold change: 0.94 ± 0.08, P < 0.05) and a significant increase in the protein content of p-glycogen synthase (P-GSS641; fold change: 1.47 ± 0.14, P < 0.05). No significant differences were observed in the total or phosphorylated protein content of other key markers of insulin-mediated signaling, oxidative metabolism, mitochondrial function, or mitochondrial dynamics (all P > 0.05). These results suggest that short-term SR reduces the maximal activity of citrate synthase, a marker of mitochondrial content, without altering the total or phosphorylated protein content of key markers of skeletal muscle mitochondrial metabolism and insulin signaling in young healthy males. NEW & NOTEWORTHY Short-term (7 day) step reduction reduces the activity of citrate synthase without altering the total or phosphorylated protein content of key markers of skeletal muscle mitochondrial metabolism and insulin signaling in young healthy males.
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Affiliation(s)
- Sophie J Edwards
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Brandon J Shad
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Ryan N Marshall
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom.,MRC-ARUK Centre for Musculoskeletal Ageing Research, University of Birmingham, United Kingdom
| | - Paul T Morgan
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Gareth Anthony Wallis
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Leigh Breen
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom.,MRC-ARUK Centre for Musculoskeletal Ageing Research, University of Birmingham, United Kingdom
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11
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Akberdin IR, Kiselev IN, Pintus SS, Sharipov RN, Vertyshev AY, Vinogradova OL, Popov DV, Kolpakov FA. A Modular Mathematical Model of Exercise-Induced Changes in Metabolism, Signaling, and Gene Expression in Human Skeletal Muscle. Int J Mol Sci 2021; 22:10353. [PMID: 34638694 PMCID: PMC8508736 DOI: 10.3390/ijms221910353] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/04/2021] [Accepted: 09/22/2021] [Indexed: 11/29/2022] Open
Abstract
Skeletal muscle is the principal contributor to exercise-induced changes in human metabolism. Strikingly, although it has been demonstrated that a lot of metabolites accumulating in blood and human skeletal muscle during an exercise activate different signaling pathways and induce the expression of many genes in working muscle fibres, the systematic understanding of signaling-metabolic pathway interrelations with downstream genetic regulation in the skeletal muscle is still elusive. Herein, a physiologically based computational model of skeletal muscle comprising energy metabolism, Ca2+, and AMPK (AMP-dependent protein kinase) signaling pathways and the expression regulation of genes with early and delayed responses was developed based on a modular modeling approach and included 171 differential equations and more than 640 parameters. The integrated modular model validated on diverse including original experimental data and different exercise modes provides a comprehensive in silico platform in order to decipher and track cause-effect relationships between metabolic, signaling, and gene expression levels in skeletal muscle.
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Affiliation(s)
- Ilya R. Akberdin
- Department of Computational Biology, Scientific Center for Information Technologies and Artificial Intelligence, Sirius University of Science and Technology, 354340 Sochi, Russia; (I.N.K.); (S.S.P.); (R.N.S.); (F.A.K.)
- BIOSOFT.RU, LLC, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
- Federal Research Center Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia
| | - Ilya N. Kiselev
- Department of Computational Biology, Scientific Center for Information Technologies and Artificial Intelligence, Sirius University of Science and Technology, 354340 Sochi, Russia; (I.N.K.); (S.S.P.); (R.N.S.); (F.A.K.)
- BIOSOFT.RU, LLC, 630090 Novosibirsk, Russia
- Laboratory of Bioinformatics, Federal Research Center for Information and Computational Technologies, 633010 Novosibirsk, Russia
| | - Sergey S. Pintus
- Department of Computational Biology, Scientific Center for Information Technologies and Artificial Intelligence, Sirius University of Science and Technology, 354340 Sochi, Russia; (I.N.K.); (S.S.P.); (R.N.S.); (F.A.K.)
- BIOSOFT.RU, LLC, 630090 Novosibirsk, Russia
- Laboratory of Bioinformatics, Federal Research Center for Information and Computational Technologies, 633010 Novosibirsk, Russia
| | - Ruslan N. Sharipov
- Department of Computational Biology, Scientific Center for Information Technologies and Artificial Intelligence, Sirius University of Science and Technology, 354340 Sochi, Russia; (I.N.K.); (S.S.P.); (R.N.S.); (F.A.K.)
- BIOSOFT.RU, LLC, 630090 Novosibirsk, Russia
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
- Laboratory of Bioinformatics, Federal Research Center for Information and Computational Technologies, 633010 Novosibirsk, Russia
| | | | - Olga L. Vinogradova
- Institute of Biomedical Problems of the Russian Academy of Sciences, 123007 Moscow, Russia;
| | - Daniil V. Popov
- Institute of Biomedical Problems of the Russian Academy of Sciences, 123007 Moscow, Russia;
| | - Fedor A. Kolpakov
- Department of Computational Biology, Scientific Center for Information Technologies and Artificial Intelligence, Sirius University of Science and Technology, 354340 Sochi, Russia; (I.N.K.); (S.S.P.); (R.N.S.); (F.A.K.)
- BIOSOFT.RU, LLC, 630090 Novosibirsk, Russia
- Laboratory of Bioinformatics, Federal Research Center for Information and Computational Technologies, 633010 Novosibirsk, Russia
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12
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Ramalingam S, Karuppiah M, Thiruppathi M, Palanivelu S, Panchanatham S. Antioxidant potential of biflavonoid attenuates hyperglycemia by modulating the carbohydrate metabolic enzymes in high fat diet/streptozotocin induced diabetic rats. Redox Rep 2021; 25:1-10. [PMID: 32013797 PMCID: PMC7034448 DOI: 10.1080/13510002.2020.1722914] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Objectives: The present study was to isolate the biflavonoid (a bimolecular kaemferol structured molecule) and test its efficacy on oxidative stress and carbohydrate metabolic key enzymes in control and high fat diet and streptozotocin -induced diabetic rats. Methods: Type 2 diabetes was induced in male albino wistar rats by feeding them with high fat diet comprising of 84.3% standard laboratory chow, 5% lard, 10% yolk powder, cholesterol 0.2%, and 0.5% bile salt for 2 weeks. After 2 weeks, the animals were kept in an overnight fast and injected with low dose of streptozotocin (35 mg/kg, dissolved in 0.1 M sodium citrate buffer, pH 4.5). Results: At the end of the experimental period, diabetic control rats showed significant increase in plasma glucose, homeostatic model assessment of insulin resistance (HOMA-IR), glycosylated hemoglobin (HbA1c) with concomitant decrease in plasma insulin, total hemoglobin and body weight. The activities of key enzymes of carbohydrate metabolism, lipid peroxidation markers, antioxidant enzymes, glycogen content and glycogen synthase and glycogen phosphorylase were also altered in diabetic rats. Discussion: Oral administration of biflavonoid to diabetic rats significantly ameliorated all the biochemical alterations to near normal levels. The effect produced by the biflavonoid on various parameters was comparable to that of metformin.
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Affiliation(s)
- Sundaram Ramalingam
- Department of Medical Biochemistry, University of Madras, Chennai, India.,Department of Biochemistry, Saveetha Dental College & Hospital, Saveetha Institute of Medical &Technical Sciences, Saveetha University, Chennai, India
| | - Muthu Karuppiah
- Department of Chemistry, Manonmaniam Sundaranar University, Tirunelveli, India
| | - Muthusamy Thiruppathi
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
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13
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Goff M, Chen G. Long-term treatment with insulin and retinoic acid increased glucose utilization in L6 muscle cells via glycogenesis. Biochem Cell Biol 2020; 98:683-697. [PMID: 33215509 DOI: 10.1139/bcb-2020-0131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The skeletal muscle regulates glucose homeostasis. Here, the effects of vitamin A metabolites including retinoic acid (RA) alone, and in combination with insulin, on glucose utilization were investigated in rat L6 muscle cells during the differentiation process. L6 cells were treated with differentiation medium containing retinol, retinal, RA, and (or) insulin. The glucose levels and pH values in the medium were measured every 2 days. The expression levels of insulin signaling and glycogen synthesis proteins, as well as glycogen content were determined. Retinal and RA reduced the glucose content and pH levels in the medium of the L6 cells. RA acted synergistically with insulin to reduce glucose and pH levels in the medium. The RA- and insulin-mediated reduction of glucose in the medium only occurred when glucose levels were at or above 15 mmol/L. Insulin-induced phosphorylation of Akt Thr308 was further enhanced by RA treatment through the activation of retinoic acid receptor. RA acted synergistically with insulin to phosphorylate glycogen synthase kinase 3β, and dephosphorylate glycogen synthase (GS), which was associated with increases in the protein and mRNA levels of GS. Increases in glycogen content were induced by insulin, and was further enhanced in the presence of RA. We conclude that activation of the RA signaling pathway enhanced insulin-induced glucose utilization in differentiating L6 cells through increases in glycogenesis.
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Affiliation(s)
- Matthew Goff
- Department of Nutrition, University of Tennessee at Knoxville, Knoxville, Tennessee, USA
- Department of Nutrition, University of Tennessee at Knoxville, Knoxville, Tennessee, USA
| | - Guoxun Chen
- Department of Nutrition, University of Tennessee at Knoxville, Knoxville, Tennessee, USA
- Department of Nutrition, University of Tennessee at Knoxville, Knoxville, Tennessee, USA
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14
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Takahashi K, Kitaoka Y, Matsunaga Y, Hatta H. Effect of post-exercise lactate administration on glycogen repletion and signaling activation in different types of mouse skeletal muscle. Curr Res Physiol 2020; 3:34-43. [PMID: 34746818 PMCID: PMC8562145 DOI: 10.1016/j.crphys.2020.07.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 01/10/2023] Open
Abstract
Lactate is not merely a metabolic intermediate that serves as an oxidizable and glyconeogenic substrate, but it is also a potential signaling molecule. The objectives of this study were to investigate whether lactate administration enhances post-exercise glycogen repletion in association with cellular signaling activation in different types of skeletal muscle. Eight-week-old male ICR mice performed treadmill running (20 m/min for 60 min) following overnight fasting (16 h). Immediately after the exercise, animals received an intraperitoneal injection of phosphate-buffered saline or sodium lactate (equivalent to 1 g/kg body weight), followed by oral ingestion of water or glucose (2 g/kg body weight). At 60 min of recovery, glucose ingestion enhanced glycogen content in the soleus, plantaris, and gastrocnemius muscles. In addition, lactate injection additively increased glycogen content in the plantaris and gastrocnemius muscles, but not in the soleus muscle. Nevertheless, lactate administration did not significantly alter protein levels related to glucose uptake and oxidation in the plantaris muscle, but enhanced phosphorylation of TBC1D1, a distal protein regulating GLUT4 translocation, was observed in the soleus muscle. Muscle FBP2 protein content was significantly higher in the plantaris and gastrocnemius muscles than in the soleus muscle, whereas MCT1 protein content was significantly higher in the soleus muscle than in the plantaris and gastrocnemius muscles. The current findings suggest that an elevated blood lactate concentration and post-exercise glucose ingestion additively enhance glycogen recovery in glycolytic phenotype muscles. This appears to be associated with glyconeogenic protein content, but not with enhanced glucose uptake, attenuated glucose oxidation, or lactate transport protein.
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Affiliation(s)
- Kenya Takahashi
- Department of Sports Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro-ku, Tokyo, 153-8902, Japan
| | - Yu Kitaoka
- Department of Human Sciences, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama, Kanagawa, 221-8686, Japan
| | - Yutaka Matsunaga
- Department of Sports Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro-ku, Tokyo, 153-8902, Japan
| | - Hideo Hatta
- Department of Sports Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro-ku, Tokyo, 153-8902, Japan
- Corresponding author. Department of Sports Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1, Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
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15
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DAS K, Khan M S, Sounder J, Mohan U, Prasad S V. Phytochemical Screening and Establishment of the Antidiabetic Potential of Aqueous Leaf Extract of the Endangered Plant Decalepis nervosa in Rats with Alloxan-induced Diabetes. Turk J Pharm Sci 2020; 17:319-328. [PMID: 32636710 DOI: 10.4274/tjps.galenos.2019.47135] [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: 04/12/2019] [Accepted: 07/20/2019] [Indexed: 12/01/2022]
Abstract
OBJECTIVES To evaluate the presence of phytochemicals in and the antidiabetic activity of aqueous extract of Decalepis nervosa (AEDN) leaf. MATERIALS AND METHODS Either sex rats were grouped into 5 classes. Alloxan monohydrate and glibenclamide were used as diabetes induction drug and standard drug, respectively. Aqueous extract of the endangered medicinal plant DN was used in two different doses. Diabetes was induced with alloxan monohydrate at 150 mg/kg b.w. The AEDN was standardized with pharmacognostic and phytochemical screening and a chemical test confirmed the presence of phytoconstituents like glycoside, alkaloid, phenols, and flavonoids. Acute toxicity was evaluated for dose selection in an antidiabetic study. RESULTS Glibenclamide (5 mg/kg b.w.) and AEDN (200 and 400 mg) were given to all rats with induced diabetes. The reduced blood glucose level may be correlated with the presence of plant secondary metabolites (phenolic compounds), which was identified by thin layer chromatography and confirmed by high performance liquid chromatography studies. The decreased levels of serum total cholesterol, triglyceride, and liver enzyme activity showed the dose dependency of AEDN extract. An oral glucose tolerance test was performed after administration of 200 and 400 mg of AEDN and 5 mg of glibenclamide to different groups, which showed significantly lower oral glucose load during blood sample collection. Animal body weight and dose of AEDN extract had a significant effect on the glucose level in blood (p<0.01). CONCLUSION The first report on the phytochemicals and therapeutic activity of AEDN leaf showed potential antidiabetic activity by increased insulin secretion via enhanced peripheral glucose utilization mechanism.
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Affiliation(s)
- Kuntal DAS
- Krupanidhi College of Pharmacy Department of Pharmacognosy and Phytochemistry, Bangalore, India
| | - Saifulla Khan M
- Krupanidhi College of Pharmacy Department of Pharmacognosy and Phytochemistry, Bangalore, India
| | - James Sounder
- Krupanidhi College of Pharmacy Department of Pharmacognosy and Phytochemistry, Bangalore, India
| | - Usha Mohan
- Krupanidhi College of Pharmacy Department of Pharmacognosy and Phytochemistry, Bangalore, India
| | - Venkatesh Prasad S
- Krupanidhi College of Pharmacy Department of Pharmacognosy and Phytochemistry, Bangalore, India
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16
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Zhang F, Icyuz M, Liu Z, Fitch M, Sun LY. Insulin sensitivity in long-lived growth hormone-releasing hormone knockout mice. Aging (Albany NY) 2020; 12:18033-18051. [PMID: 32640420 PMCID: PMC7585079 DOI: 10.18632/aging.103588] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/05/2020] [Indexed: 01/24/2023]
Abstract
Our previous studies showed that loss-of-function mutation of growth hormone releasing hormone (GHRH) results in increased longevity and enhanced insulin sensitivity in mice. However, the details of improved insulin action and tissue-specific insulin signaling are largely unknown in this healthy-aging mouse model. We conducted hyperinsulinemic-euglycemic clamp to investigate mechanisms underlying enhanced insulin sensitivity in growth hormone (GH) deficient mice. Further, we assessed in vivo tissue-specific insulin activity via activation of PI3K-AKT and MAPK-ERK1/2 cascades using western blot. Clamp results showed that the glucose infusion rate required for maintaining euglycemia was much higher in GHRH-/- mice compared to WT controls. Insulin-mediated glucose production was largely suppressed, whereas glucose uptake in skeletal muscle and brown adipose tissue were significant enhanced in GHRH-/- mice compared to WT controls. Enhanced capacity of insulin-induced activation of the PI3K-AKT and MAPK-ERK1/2 signaling were observed in a tissue-specific manner in GHRH-/- mice. Enhanced systemic insulin sensitivity in long-lived GHRH-/- mice is associated with differential activation of insulin signaling cascades among various organs. Improved action of insulin in the insulin sensitive tissues is likely to mediate the prolonged longevity and healthy-aging effects of GH deficiency in mice.
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Affiliation(s)
- Fang Zhang
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35254, USA
| | - Mert Icyuz
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35254, USA
| | - Zhenghui Liu
- Department of Obstetrics and Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Michael Fitch
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35254, USA
| | - Liou Y. Sun
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL 35254, USA
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17
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Huang P, Chen K, Ma T, Cao N, Weng D, Xu C, Xu L. The effects of short-term treatment of microcystin-LR on the insulin pathway in both the HL7702 cell line and livers of mice. ENVIRONMENTAL TOXICOLOGY 2020; 35:727-737. [PMID: 32073747 DOI: 10.1002/tox.22907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/07/2019] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Our previous work indicated exposure of Human liver cell 7702 (HL7702) cells to Microcystin-leucine-arginine (MC-LR) for 24 hours can disrupt insulin (INS) signaling by the hyperphosphorylation of specific proteins. For further exploring the time-dependent effect posed by MC-LR on this pathway, in the current study, HL7702 cells together with mice were exposed to the MC-LR with different concentrations under short-term treatment, and then, protein phosphatase 2A (PP2A) activity and expression of proteins related to INS signaling, as well as the characteristics of their action in the liver, were investigated. The results indicated, in HL7702 cells with 0.5, 1, and 6 hours of treatment by MC-LR, PP2A activity showed an obvious decrease in a time and concentration-dependent manner. While the total protein level of Akt, glycogen synthase kinase 3 (GSK-3), and glycogen synthase remained unchanged, GSK-3 and Akt phosphorylation increased significantly. In livers of mice with 1 hour of intraperitoneal injection with MC-LR, a similar change in these proteins was observed. In addition, the levels of total IRS1 and p-IRS1 at serine sites showed decreasing and increasing trends,respectively, and the hematoxylin and eosin staining showed that liver tissues of mice in the maximum-dose group exhibited obvious hepatocyte degeneration and hemorrhage. Our results further proved that short-term treatment with MC-LR can inhibit PP2A activity and disrupt INS signaling proteins' phosphorylation level, thereby interfering with the INS pathway. Our findings provide a helpful understanding of the toxic effects posed by MC-LR on the glucose metabolism of liver via interference with the INS signaling pathway.
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Affiliation(s)
- Pu Huang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Kele Chen
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Tianfeng Ma
- Department I of Clinical Medicine, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Naifang Cao
- Department I of Clinical Medicine, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Dengpo Weng
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
| | - Chun Xu
- Department of Endocrinology, The Third Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Lihong Xu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, China
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18
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Bolotta A, Filardo G, Abruzzo PM, Astolfi A, De Sanctis P, Di Martino A, Hofer C, Indio V, Kern H, Löfler S, Marcacci M, Zampieri S, Marini M, Zucchini C. Skeletal Muscle Gene Expression in Long-Term Endurance and Resistance Trained Elderly. Int J Mol Sci 2020; 21:ijms21113988. [PMID: 32498275 PMCID: PMC7312229 DOI: 10.3390/ijms21113988] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 05/23/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023] Open
Abstract
Physical exercise is deemed the most efficient way of counteracting the age-related decline of skeletal muscle. Here we report a transcriptional study by next-generation sequencing of vastus lateralis biopsies from elderly with a life-long high-level training practice (n = 9) and from age-matched sedentary subjects (n = 5). Unsupervised mixture distribution analysis was able to correctly categorize trained and untrained subjects, whereas it failed to discriminate between individuals who underwent a prevalent endurance (n = 5) or a prevalent resistance (n = 4) training, thus showing that the training mode was not relevant for sarcopenia prevention. KEGG analysis of transcripts showed that physical exercise affected a high number of metabolic and signaling pathways, in particular those related to energy handling and mitochondrial biogenesis, where AMPK and AKT-mTOR signaling pathways are both active and balance each other, concurring to the establishment of an insulin-sensitive phenotype and to the maintenance of a functional muscle mass. Other pathways affected by exercise training increased the efficiency of the proteostatic mechanisms, consolidated the cytoskeletal organization, lowered the inflammation level, and contrasted cellular senescence. This study on extraordinary individuals who trained at high level for at least thirty years suggests that aging processes and exercise training travel the same paths in the opposite direction.
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Affiliation(s)
- Alessandra Bolotta
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna School of Medicine, 40138 Bologna, Italy; (A.B.); (P.D.S.); (M.M.); (C.Z.)
- IRCCS Fondazione Don Carlo Gnocchi, 20148 Milan, Italy
| | - Giuseppe Filardo
- Applied and Translational Research Center, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy;
| | - Provvidenza Maria Abruzzo
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna School of Medicine, 40138 Bologna, Italy; (A.B.); (P.D.S.); (M.M.); (C.Z.)
- IRCCS Fondazione Don Carlo Gnocchi, 20148 Milan, Italy
- Correspondence: ; Tel.: +39-051-2094122
| | - Annalisa Astolfi
- Giorgio Prodi Interdepartimental Center for Cancer Research, S.Orsola-Malpighi Hospital, 40138 Bologna, Italy; (A.A.); (V.I.)
- Department of Morphology, Surgery and Experimental Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Paola De Sanctis
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna School of Medicine, 40138 Bologna, Italy; (A.B.); (P.D.S.); (M.M.); (C.Z.)
| | - Alessandro Di Martino
- Second Orthopaedic and Traumatologic Clinic, IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy;
| | - Christian Hofer
- Ludwig Boltzmann Institute for Rehabilitation Research, 1160 Wien, Austria; (C.H.); (H.K.); (S.L.)
| | - Valentina Indio
- Giorgio Prodi Interdepartimental Center for Cancer Research, S.Orsola-Malpighi Hospital, 40138 Bologna, Italy; (A.A.); (V.I.)
| | - Helmut Kern
- Ludwig Boltzmann Institute for Rehabilitation Research, 1160 Wien, Austria; (C.H.); (H.K.); (S.L.)
| | - Stefan Löfler
- Ludwig Boltzmann Institute for Rehabilitation Research, 1160 Wien, Austria; (C.H.); (H.K.); (S.L.)
| | - Maurilio Marcacci
- Department of Biomedical Sciences, Knee Joint Reconstruction Center, 3rd Orthopaedic Division, Humanitas Clinical Institute, Humanitas University, 20089 Milan, Italy;
| | - Sandra Zampieri
- Department of Surgery, Oncology and Gastroenterology, University of Padua, 35122 Padua, Italy;
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
| | - Marina Marini
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna School of Medicine, 40138 Bologna, Italy; (A.B.); (P.D.S.); (M.M.); (C.Z.)
- IRCCS Fondazione Don Carlo Gnocchi, 20148 Milan, Italy
| | - Cinzia Zucchini
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna School of Medicine, 40138 Bologna, Italy; (A.B.); (P.D.S.); (M.M.); (C.Z.)
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19
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Takahashi Y, Matsunaga Y, Banjo M, Takahashi K, Sato Y, Seike K, Nakano S, Hatta H. Effects of Nutrient Intake Timing on Post-Exercise Glycogen Accumulation and its Related Signaling Pathways in Mouse Skeletal Muscle. Nutrients 2019; 11:nu11112555. [PMID: 31652791 PMCID: PMC6893707 DOI: 10.3390/nu11112555] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/17/2019] [Accepted: 10/21/2019] [Indexed: 01/19/2023] Open
Abstract
We investigated the effects of nutrient intake timing on glycogen accumulation and its related signals in skeletal muscle after an exercise that did not induce large glycogen depletion. Male ICR mice ran on a treadmill at 25 m/min for 60 min under a fed condition. Mice were orally administered a solution containing 1.2 mg/g carbohydrate and 0.4 mg/g protein or water either immediately (early nutrient, EN) or 180 min (late nutrient, LN) after the exercise. Tissues were harvested at 30 min after the oral administration. No significant difference in blood glucose or plasma insulin concentrations was found between the EN and LN groups. The plantaris muscle glycogen concentration was significantly (p < 0.05) higher in the EN group—but not in the LN group—compared to the respective time-matched control group. Akt Ser473 phosphorylation was significantly higher in the EN group than in the time-matched control group (p < 0.01), while LN had no effect. Positive main effects of time were found for the phosphorylations in Akt substrate of 160 kDa (AS160) Thr642 (p < 0.05), 5′-AMP-activated protein kinase (AMPK) Thr172 (p < 0.01), and acetyl-CoA carboxylase Ser79 (p < 0.01); however, no effect of nutrient intake was found for these. We showed that delayed nutrient intake could not increase muscle glycogen after endurance exercise which did not induce large glycogen depletion. The results also suggest that post-exercise muscle glycogen accumulation after nutrient intake might be partly influenced by Akt activation. Meanwhile, increased AS160 and AMPK activation by post-exercise fasting might not lead to glycogen accumulation.
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Affiliation(s)
- Yumiko Takahashi
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Yutaka Matsunaga
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Mai Banjo
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Kenya Takahashi
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Yosuke Sato
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Kohei Seike
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Suguru Nakano
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
| | - Hideo Hatta
- Department of Sports Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo 153-8902, Japan.
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20
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Sergi D, Naumovski N, Heilbronn LK, Abeywardena M, O'Callaghan N, Lionetti L, Luscombe-Marsh N. Mitochondrial (Dys)function and Insulin Resistance: From Pathophysiological Molecular Mechanisms to the Impact of Diet. Front Physiol 2019; 10:532. [PMID: 31130874 PMCID: PMC6510277 DOI: 10.3389/fphys.2019.00532] [Citation(s) in RCA: 185] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 04/15/2019] [Indexed: 12/17/2022] Open
Abstract
Mitochondrial dysfunction has been implicated in the pathogenesis of insulin resistance, the hallmark of type 2 diabetes mellitus (T2DM). However, the cause-effect relationship remains to be fully elucidated. Compelling evidence suggests that boosting mitochondrial function may represent a valuable therapeutic tool to improve insulin sensitivity. Mitochondria are highly dynamic organelles, which adapt to short- and long-term metabolic perturbations by undergoing fusion and fission cycles, spatial rearrangement of the electron transport chain complexes into supercomplexes and biogenesis governed by peroxisome proliferator-activated receptor γ co-activator 1α (PGC 1α). However, these processes appear to be dysregulated in type 2 diabetic individuals. Herein, we describe the mechanistic link between mitochondrial dysfunction and insulin resistance in skeletal muscle alongside the intracellular pathways orchestrating mitochondrial bioenergetics. We then review current evidence on nutritional tools, including fatty acids, amino acids, caloric restriction and food bioactive derivatives, which may enhance insulin sensitivity by therapeutically targeting mitochondrial function and biogenesis.
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Affiliation(s)
- Domenico Sergi
- Nutrition and Health Substantiation Group, Nutrition and Health Program, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Adelaide, SA, Australia.,Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
| | - Nenad Naumovski
- Faculty of Health, University of Canberra, Canberra, ACT, Australia.,Collaborative Research in Bioactives and Biomarkers (CRIBB) Group, Canberra, ACT, Australia
| | | | - Mahinda Abeywardena
- Nutrition and Health Substantiation Group, Nutrition and Health Program, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Adelaide, SA, Australia
| | - Nathan O'Callaghan
- Nutrition and Health Substantiation Group, Nutrition and Health Program, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Adelaide, SA, Australia
| | - Lillà Lionetti
- Department of Chemistry and Biology "A. Zambelli", University of Salerno, Fisciano, Italy
| | - Natalie Luscombe-Marsh
- Nutrition and Health Substantiation Group, Nutrition and Health Program, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Adelaide, SA, Australia.,Adelaide Medical School, The University of Adelaide, Adelaide, SA, Australia
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21
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Possik E, Pause A. Biochemical Measurement of Glycogen: Method to Investigate the AMPK-Glycogen Relationship. Methods Mol Biol 2018; 1732:57-67. [PMID: 29480468 DOI: 10.1007/978-1-4939-7598-3_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Glycogen is a main carbohydrate energy storage primarily found in fungi and animals. It is a glucose polymer that comprises α(1-4) glycosidic linkages attaching UDP-glucose molecules linearly and α(1-6) linkages branching glucose chains every 8-10 molecules to the main backbone chain. Glycogen synthase, branching enzyme, and glycogen phosphorylase are key enzymes involved in glycogen synthesis and degradation. These enzymes are tightly regulated by upstream kinases and phosphatases that respond to hormonal cues in order to coordinate storage and degradation and meet the cellular and organismal metabolic needs. The 5'AMP-activated protein kinase (AMPK) is one of the main regulators of glycogen metabolism. Despite extensive research, the role of AMPK in glycogen synthesis and degradation remains controversial. Specifically, the level and duration of AMPK activity highly influence the outcome on glycogen reserves. Here, we describe a rapid and robust protocol to efficiently measure the levels of glycogen in vitro. We use the commercially available glycogen determination kit to hydrolyze glycogen into glucose, which is oxidized to form D-gluconic acid and hydrogen peroxide that react with the OxiRed/Amplex Red probe generating a product that could be detected either in a colorimetric or fluorimetric plate format. This method is quantitative and could be used to address the role of AMPK in glycogen metabolism in cells and tissues. Summary This chapter provides a quick and reliable biochemical quantitative method to measure glycogen in cells and tissues. Briefly, this method is based on the degradation of glycogen to glucose, which is then specifically oxidized to generate a product that reacts with the OxiRed probe with maximum absorbance at 570 nm. This method is very accurate and highly sensitive. In the notes of this chapter, we shed the light on important actions that should be followed to get reliable results. We also state advantages and disadvantages of this method in comparison to other glycogen measurement techniques.
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Affiliation(s)
- Elite Possik
- Goodman Cancer Research Centre, Biochemistry Department, McGill University, Montreal, Canada
| | - Arnim Pause
- Goodman Cancer Research Centre, Biochemistry Department, McGill University, Montreal, Canada.
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22
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Liu J, Xu C, Zhang S, Li H, Chen K, Huang P, Guo Z, Xu L. Microcystin-LR disrupts insulin signaling by hyperphosphorylating insulin receptor substrate 1 and glycogen synthase. ENVIRONMENTAL TOXICOLOGY 2018; 33:16-22. [PMID: 28984034 DOI: 10.1002/tox.22456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 07/21/2017] [Accepted: 07/27/2017] [Indexed: 06/07/2023]
Abstract
Microcystin-LR (MC-LR) is a cyanobacteria-derived heptapeptide that has been commonly characterized as a hepatotoxin. Although the liver is a primary organ in glucose homeostasis, the effect of MC-LR on glucose metabolism remains unclear. In this study, the human liver cell line HL7702 and ICR mice were exposed to various concentrations of MC-LR for 24 h, and the proteins involved in insulin signaling were investigated. The results showed that MC-LR treatment induced the hyperphosphorylation of insulin receptor substrate 1 (IRS1) at several serine sites, S307, S323, S636/639, and S1101 in HL7702 cells, and S302, S318, S632/635, and S1097 in mice livers. In addition, the activation of S6K1 was demonstrated to play an important role in MC-LR-induced IRS1 hyperphosphorylation at several serine sites. Decreased levels of total IRS1 were observed in the mice livers, but there was no significant change in HL7702 cells. MC-LR also induced glycogen synthase (GS) hyperphosphorylation at S641 (inactivating GS) both in vitro and in vivo, even glycogen synthase kinase 3, a well-known GS kinase, was inactivated after MC-LR treatment. Moreover, MC-LR could block insulin-induced GS activation. In addition, glucose transport in liver cells was not impacted by MC-LR either with or without insulin stimulation. Our study implies that MC-LR can interfere with the actions of IRS1 and GS in insulin signaling and may have a toxic effect on glucose metabolism in the liver.
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Affiliation(s)
- Jinghui Liu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Chun Xu
- Department of Endocrinology, General Hospital of the Chinese People's Armed Police Forces, Beijing, 100039, China
| | - Shaofeng Zhang
- Department of Endocrinology, General Hospital of the Chinese People's Armed Police Forces, Beijing, 100039, China
| | - Haoyan Li
- Department of Endocrinology, General Hospital of the Chinese People's Armed Police Forces, Beijing, 100039, China
| | - Kele Chen
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Pu Huang
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Zonglou Guo
- Department of Biosystem Engineering, College of Biosystem Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Lihong Xu
- Department of Biochemistry, School of Medicine, Zhejiang University, Hangzhou, 310058, China
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23
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24
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Resistance training regulates gene expression of molecules associated with intramyocellular lipids, glucose signaling and fiber size in old rats. Sci Rep 2017; 7:8593. [PMID: 28819168 PMCID: PMC5561018 DOI: 10.1038/s41598-017-09343-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 07/17/2017] [Indexed: 11/08/2022] Open
Abstract
Sarcopenia is a complex multifactorial process, some of which involves fat infiltration. Intramyocellular lipid (IMCL) accumulation is postulated to play a role on sarcopenia during aging, which is believed to be due alterations in glucose homeostasis in the skeletal muscle. Sarcopenia, along with intramuscular lipids, is associated with physical inactivity. Resistance training (RT) has been indicated to minimize the age-induced muscle skeletal adaptations. Thus, we aimed to investigate the effects of RT on mRNA levels of regulatory components related to intramyocellular lipid, glucose metabolism and fiber size in soleus and gastrocnemius muscles of aged rats. Old male rats were submitted to RT (ladder climbing, progressive load, 3 times a week for 12 weeks). Age-induced accumulation of IMCL was attenuated by RT, which was linked to a PPARy-mediated mechanism, concomitant to enhanced regulatory components of glucose homeostasis (GLUT-4, G6PDH, Hk-2 and Gly-Syn-1). These responses were also linked to decreased catabolic (TNF-α, TWEAK/Fn14 axis; FOXO-1, Atrogin-1 and MuRF1; Myostatin) and increased anabolic intracellular pathways (IGF-1-mTOR-p70S6sk-1 axis; MyoD) in muscles of trained aged rats. Our results point out the importance of RT on modulation of gene expression of intracellular regulators related to age-induced morphological and metabolic adaptations in skeletal muscle.
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25
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Kjøbsted R, Wojtaszewski JFP, Treebak JT. Role of AMP-Activated Protein Kinase for Regulating Post-exercise Insulin Sensitivity. ACTA ACUST UNITED AC 2017; 107:81-126. [PMID: 27812978 DOI: 10.1007/978-3-319-43589-3_5] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Skeletal muscle insulin resistance precedes development of type 2 diabetes (T2D). As skeletal muscle is a major sink for glucose disposal, understanding the molecular mechanisms involved in maintaining insulin sensitivity of this tissue could potentially benefit millions of people that are diagnosed with insulin resistance. Regular physical activity in both healthy and insulin-resistant individuals is recognized as the single most effective intervention to increase whole-body insulin sensitivity and thereby positively affect glucose homeostasis. A single bout of exercise has long been known to increase glucose disposal in skeletal muscle in response to physiological insulin concentrations. While this effect is identified to be restricted to the previously exercised muscle, the molecular basis for an apparent convergence between exercise- and insulin-induced signaling pathways is incompletely known. In recent years, we and others have identified the Rab GTPase-activating protein, TBC1 domain family member 4 (TBC1D4) as a target of key protein kinases in the insulin- and exercise-activated signaling pathways. Our working hypothesis is that the AMP-activated protein kinase (AMPK) is important for the ability of exercise to insulin sensitize skeletal muscle through TBC1D4. Here, we aim to provide an overview of the current available evidence linking AMPK to post-exercise insulin sensitivity.
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Affiliation(s)
- Rasmus Kjøbsted
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Integrative Physiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen, Denmark
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Jonas T Treebak
- Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Integrative Physiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, 2200, Copenhagen, Denmark.
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26
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Blesson CS, Chinnathambi V, Kumar S, Yallampalli C. Gestational Protein Restriction Impairs Glucose Disposal in the Gastrocnemius Muscles of Female Rats. Endocrinology 2017; 158:756-767. [PMID: 28324067 PMCID: PMC5460798 DOI: 10.1210/en.2016-1675] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 01/23/2017] [Indexed: 01/18/2023]
Abstract
Gestational low-protein (LP) diet causes hyperglycemia and insulin resistance in adult offspring, but the mechanism is not clearly understood. In this study, we explored the role of insulin signaling in gastrocnemius muscles of gestational LP-exposed female offspring. Pregnant rats were fed a control (20% protein) or an isocaloric LP (6%) diet from gestational day 4 until delivery. Normal diet was given to mothers after delivery and to pups after weaning until necropsy. Offspring were euthanized at 4 months, and gastrocnemius muscles were treated with insulin ex vivo for 30 minutes. Messenger RNA and protein levels of molecules involved in insulin signaling were assessed at 4 months. LP females were smaller at birth but showed rapid catchup growth by 4 weeks. Glucose tolerance test in LP offspring at 3 months showed elevated serum glucose levels (P < 0.01; glycemia Δ area under the curve 342 ± 28 in LP vs 155 ± 23 in controls, mmol/L * 120 minutes) without any change in insulin levels. In gastrocnemius muscles, LP rats showed reduced tyrosine phosphorylation of insulin receptor substrate 1 upon insulin stimulation due to the overexpression of tyrosine phosphatase SHP-2, but serine phosphorylation was unaffected. Furthermore, insulin-induced phosphorylation of Akt, glycogen synthase kinase (GSK)-3α, and GSK-3β was diminished in LP rats, and they displayed an increased basal phosphorylation (inactive form) of glycogen synthase. Our study shows that gestational protein restriction causes peripheral insulin resistance by a series of phosphorylation defects in skeletal muscle in a mechanism involving insulin receptor substrate 1, SHP-2, Akt, GSK-3, and glycogen synthase causing dysfunctional GSK-3 signaling and increased stored glycogen, leading to distorted glucose homeostasis.
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Affiliation(s)
| | - Vijayakumar Chinnathambi
- Department of Obstetrics & Gynecology, University of Texas Medical Branch, Galveston, Texas 77555
| | - Sathish Kumar
- Department of Obstetrics & Gynecology, University of Texas Medical Branch, Galveston, Texas 77555
| | - Chandrasekhar Yallampalli
- Basic Sciences Perinatology Research Laboratories, Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas 77030
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27
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Analysis of Differentially Expressed Genes in Gastrocnemius Muscle between DGAT1 Transgenic Mice and Wild-Type Mice. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5404682. [PMID: 28386555 PMCID: PMC5366756 DOI: 10.1155/2017/5404682] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 01/22/2017] [Indexed: 11/17/2022]
Abstract
Adipose tissue was the major energy deposition site of the mammals and provided the energy for the body and released the external pressure to the internal organs. In animal production, fat deposition in muscle can affect the meat quality, especially the intramuscular fat (IMF) content. Diacylglycerol acyltransferase-1 (DGAT1) was the key enzyme to control the synthesis of the triacylglycerol in adipose tissue. In order to better understand the regulation mechanism of the DGAT1 in the intramuscular fat deposition, the global gene expression profiling was performed in gastrocnemius muscle between DGAT1 transgenic mice and wild-type mice by microarray. 281 differentially expressed transcripts were identified with at least 1.5-fold change and the p value < 0.05. 169 transcripts were upregulated and 112 transcripts were downregulated. Ten genes (SREBF1, DUSP1, PLAGL1, FKBP5, ZBTB16, PPP1R3C, CDC14A, GLUL, PDK4, and UCP3) were selected to validate the reliability of the chip's results by the real-time PCR. The finding of RT-PCR was consistent with the gene chip. Seventeen signal pathways were analyzed using KEGG pathway database and the pathways concentrated mainly on the G-protein coupled receptor protein signaling pathway, signal transduction, oxidation-reduction reaction, olfactory receptor activity, protein binding, and zinc ion binding. This study implied a function role of DGAT1 in the synthesis of TAG, insulin resistance, and IMF deposition.
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28
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Mansueto G, Armani A, Viscomi C, D'Orsi L, De Cegli R, Polishchuk EV, Lamperti C, Di Meo I, Romanello V, Marchet S, Saha PK, Zong H, Blaauw B, Solagna F, Tezze C, Grumati P, Bonaldo P, Pessin JE, Zeviani M, Sandri M, Ballabio A. Transcription Factor EB Controls Metabolic Flexibility during Exercise. Cell Metab 2017; 25:182-196. [PMID: 28011087 PMCID: PMC5241227 DOI: 10.1016/j.cmet.2016.11.003] [Citation(s) in RCA: 220] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 06/24/2016] [Accepted: 11/05/2016] [Indexed: 11/28/2022]
Abstract
The transcription factor EB (TFEB) is an essential component of lysosomal biogenesis and autophagy for the adaptive response to food deprivation. To address the physiological function of TFEB in skeletal muscle, we have used muscle-specific gain- and loss-of-function approaches. Here, we show that TFEB controls metabolic flexibility in muscle during exercise and that this action is independent of peroxisome proliferator-activated receptor-γ coactivator1α (PGC1α). Indeed, TFEB translocates into the myonuclei during physical activity and regulates glucose uptake and glycogen content by controlling expression of glucose transporters, glycolytic enzymes, and pathways related to glucose homeostasis. In addition, TFEB induces the expression of genes involved in mitochondrial biogenesis, fatty acid oxidation, and oxidative phosphorylation. This coordinated action optimizes mitochondrial substrate utilization, thus enhancing ATP production and exercise capacity. These findings identify TFEB as a critical mediator of the beneficial effects of exercise on metabolism.
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Affiliation(s)
- Gelsomina Mansueto
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Andrea Armani
- Department of Biomedical Science, University of Padova, Padova 35121, Italy
| | - Carlo Viscomi
- MRC Mitochondrial Biology Unit, Cambridge CB2 0XY, UK; Fondazione IRCCS Istituto Neurologico "C. Besta," 20133 Milan, Italy
| | - Luca D'Orsi
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Rossella De Cegli
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Elena V Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Costanza Lamperti
- Fondazione IRCCS Istituto Neurologico "C. Besta," 20133 Milan, Italy
| | - Ivano Di Meo
- Fondazione IRCCS Istituto Neurologico "C. Besta," 20133 Milan, Italy
| | - Vanina Romanello
- Department of Biomedical Science, University of Padova, Padova 35121, Italy; Venetian Institute of Molecular Medicine, Padova 35129, Italy
| | - Silvia Marchet
- Fondazione IRCCS Istituto Neurologico "C. Besta," 20133 Milan, Italy
| | - Pradip K Saha
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Haihong Zong
- Hepatobiliary, Pancreatic, and Intestinal Research Institute, North Sichuan Medical College, Nanchong, Sichuan 637000, China; Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Bert Blaauw
- Department of Biomedical Science, University of Padova, Padova 35121, Italy
| | - Francesca Solagna
- Department of Biomedical Science, University of Padova, Padova 35121, Italy
| | - Caterina Tezze
- Department of Biomedical Science, University of Padova, Padova 35121, Italy
| | - Paolo Grumati
- Department of Molecular Medicine, University of Padova, Padova 35121, Italy
| | - Paolo Bonaldo
- Department of Molecular Medicine, University of Padova, Padova 35121, Italy
| | - Jeffrey E Pessin
- Departments of Medicine and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Massimo Zeviani
- MRC Mitochondrial Biology Unit, Cambridge CB2 0XY, UK; Fondazione IRCCS Istituto Neurologico "C. Besta," 20133 Milan, Italy
| | - Marco Sandri
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy; Department of Biomedical Science, University of Padova, Padova 35121, Italy; Venetian Institute of Molecular Medicine, Padova 35129, Italy.
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy; Medical Genetics, Department of Pediatrics, Federico II University, Via Pansini 5, 80131 Naples, Italy; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030, USA.
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29
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Andersson LE, Nicholas LM, Filipsson K, Sun J, Medina A, Al-Majdoub M, Fex M, Mulder H, Spégel P. Glycogen metabolism in the glucose-sensing and supply-driven β-cell. FEBS Lett 2016; 590:4242-4251. [PMID: 27943300 DOI: 10.1002/1873-3468.12460] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 07/25/2016] [Accepted: 09/29/2016] [Indexed: 12/24/2022]
Abstract
Glycogen metabolism in β-cells may affect downstream metabolic pathways controlling insulin release. We examined glycogen metabolism in human islets and in the rodent-derived INS-1 832/13 β-cells and found them to express the same isoforms of key enzymes required for glycogen metabolism. Our findings indicate that glycogenesis is insulin-independent but influenced by extracellular glucose concentrations. Levels of glycogen synthase decrease with increasing glucose concentrations, paralleling accumulation of glycogen. We did not find cAMP-elicited glycogenolysis and insulin secretion to be causally related. In conclusion, our results reveal regulated glycogen metabolism in human islets and insulin-secreting cells. Whether glycogen metabolism affects insulin secretion under physiological conditions remains to be determined.
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Affiliation(s)
- Lotta E Andersson
- Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Malmö, Sweden
| | - Lisa M Nicholas
- Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Malmö, Sweden
| | - Karin Filipsson
- Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Malmö, Sweden
| | - Jiangming Sun
- Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Malmö, Sweden
| | - Anya Medina
- Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Malmö, Sweden
| | - Mahmoud Al-Majdoub
- Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Malmö, Sweden
| | - Malin Fex
- Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Malmö, Sweden
| | - Hindrik Mulder
- Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Malmö, Sweden
| | - Peter Spégel
- Department of Clinical Sciences, Unit of Molecular Metabolism, Lund University Diabetes Centre, CRC, Malmö, Sweden.,Department of Chemistry, Centre for Analysis and Synthesis, Lund University, Sweden
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30
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Maile CA, Hingst JR, Mahalingan KK, O'Reilly AO, Cleasby ME, Mickelson JR, McCue ME, Anderson SM, Hurley TD, Wojtaszewski JFP, Piercy RJ. A highly prevalent equine glycogen storage disease is explained by constitutive activation of a mutant glycogen synthase. Biochim Biophys Acta Gen Subj 2016; 1861:3388-3398. [PMID: 27592162 DOI: 10.1016/j.bbagen.2016.08.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 08/15/2016] [Accepted: 08/30/2016] [Indexed: 01/16/2023]
Abstract
BACKGROUND Equine type 1 polysaccharide storage myopathy (PSSM1) is associated with a missense mutation (R309H) in the glycogen synthase (GYS1) gene, enhanced glycogen synthase (GS) activity and excessive glycogen and amylopectate inclusions in muscle. METHODS Equine muscle biochemical and recombinant enzyme kinetic assays in vitro and homology modelling in silico, were used to investigate the hypothesis that higher GS activity in affected horse muscle is caused by higher GS expression, dysregulation, or constitutive activation via a conformational change. RESULTS PSSM1-affected horse muscle had significantly higher glycogen content than control horse muscle despite no difference in GS expression. GS activity was significantly higher in muscle from homozygous mutants than from heterozygote and control horses, in the absence and presence of the allosteric regulator, glucose 6 phosphate (G6P). Muscle from homozygous mutant horses also had significantly increased GS phosphorylation at sites 2+2a and significantly higher AMPKα1 (an upstream kinase) expression than controls, likely reflecting a physiological attempt to reduce GS enzyme activity. Recombinant mutant GS was highly active with a considerably lower Km for UDP-glucose, in the presence and absence of G6P, when compared to wild type GS, and despite its phosphorylation. CONCLUSIONS Elevated activity of the mutant enzyme is associated with ineffective regulation via phosphorylation rendering it constitutively active. Modelling suggested that the mutation disrupts a salt bridge that normally stabilises the basal state, shifting the equilibrium to the enzyme's active state. GENERAL SIGNIFICANCE This study explains the gain of function pathogenesis in this highly prevalent polyglucosan myopathy.
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Affiliation(s)
- C A Maile
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, UK
| | - J R Hingst
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - K K Mahalingan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, USA
| | - A O O'Reilly
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK
| | - M E Cleasby
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, UK
| | - J R Mickelson
- Veterinary Biomedical Sciences Department, University of Minnesota, St. Paul, MN, USA
| | - M E McCue
- Veterinary Population Medicine Department, University of Minnesota, St. Paul, MN, USA
| | - S M Anderson
- Veterinary Population Medicine Department, University of Minnesota, St. Paul, MN, USA
| | - T D Hurley
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, USA
| | - J F P Wojtaszewski
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Denmark
| | - R J Piercy
- Comparative Neuromuscular Diseases Laboratory, Department of Clinical Sciences and Services, Royal Veterinary College, London, UK.
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31
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Zois CE, Harris AL. Glycogen metabolism has a key role in the cancer microenvironment and provides new targets for cancer therapy. J Mol Med (Berl) 2016; 94:137-54. [PMID: 26882899 PMCID: PMC4762924 DOI: 10.1007/s00109-015-1377-9] [Citation(s) in RCA: 160] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 12/21/2015] [Accepted: 12/28/2015] [Indexed: 12/13/2022]
Abstract
Metabolic reprogramming is a hallmark of cancer cells and contributes to their adaption within the tumour microenvironment and resistance to anticancer therapies. Recently, glycogen metabolism has become a recognised feature of cancer cells since it is upregulated in many tumour types, suggesting that it is an important aspect of cancer cell pathophysiology. Here, we provide an overview of glycogen metabolism and its regulation, with a focus on its role in metabolic reprogramming of cancer cells under stress conditions such as hypoxia, glucose deprivation and anticancer treatment. The various methods to detect glycogen in tumours in vivo as well as pharmacological modulators of glycogen metabolism are also reviewed. Finally, we discuss the therapeutic value of targeting glycogen metabolism as a strategy for combinational approaches in cancer treatment.
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Affiliation(s)
- Christos E Zois
- Molecular Oncology Laboratories, Department of Oncology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford University, Oxford, OX3 9DS, UK.
| | - Adrian L Harris
- Molecular Oncology Laboratories, Department of Oncology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford University, Oxford, OX3 9DS, UK.
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Ceperuelo-Mallafré V, Ejarque M, Serena C, Duran X, Montori-Grau M, Rodríguez MA, Yanes O, Núñez-Roa C, Roche K, Puthanveetil P, Garrido-Sánchez L, Saez E, Tinahones FJ, Garcia-Roves PM, Gómez-Foix AM, Saltiel AR, Vendrell J, Fernández-Veledo S. Adipose tissue glycogen accumulation is associated with obesity-linked inflammation in humans. Mol Metab 2015; 5:5-18. [PMID: 26844203 PMCID: PMC4703799 DOI: 10.1016/j.molmet.2015.10.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 10/02/2015] [Accepted: 10/09/2015] [Indexed: 01/14/2023] Open
Abstract
Objective Glycogen metabolism has emerged as a mediator in the control of energy homeostasis and studies in murine models reveal that adipose tissue might contain glycogen stores. Here we investigated the physio(patho)logical role of glycogen in human adipose tissue in the context of obesity and insulin resistance. Methods We studied glucose metabolic flux of hypoxic human adipoctyes by nuclear magnetic resonance and mass spectrometry-based metabolic approaches. Glycogen synthesis and glycogen content in response to hypoxia was analyzed in human adipocytes and macrophages. To explore the metabolic effects of enforced glycogen deposition in adipocytes and macrophages, we overexpressed PTG, the only glycogen-associated regulatory subunit (PP1-GTS) reported in murine adipocytes. Adipose tissue gene expression analysis was performed on wild type and homozygous PTG KO male mice. Finally, glycogen metabolism gene expression and glycogen accumulation was analyzed in adipose tissue, mature adipocytes and resident macrophages from lean and obese subjects with different degrees of insulin resistance in 2 independent cohorts. Results We show that hypoxia modulates glucose metabolic flux in human adipocytes and macrophages and promotes glycogenesis. Enforced glycogen deposition by overexpression of PTG re-orients adipocyte secretion to a pro-inflammatory response linked to insulin resistance and monocyte/lymphocyte migration. Furthermore, glycogen accumulation is associated with inhibition of mTORC1 signaling and increased basal autophagy flux, correlating with greater leptin release in glycogen-loaded adipocytes. PTG-KO mice have reduced expression of key inflammatory genes in adipose tissue and PTG overexpression in M0 macrophages induces a pro-inflammatory and glycolytic M1 phenotype. Increased glycogen synthase expression correlates with glycogen deposition in subcutaneous adipose tissue of obese patients. Glycogen content in subcutaneous mature adipocytes is associated with BMI and leptin expression. Conclusion Our data establish glycogen mishandling in adipose tissue as a potential key feature of inflammatory-related metabolic stress in human obesity. Hypoxia redirects extracellular glucose to glycogen synthesis in human adipocytes. Glycogen modifies the endocrine function of adipocytes and induces insulin resistance. Glycogen stimulates leptin secretion through an autophagy-dependent mechanism. Enforced glycogen accumulation in macrophages promotes M1 polarization. Obesity is associated with higher GS expression and glycogen stores in adipose tissue.
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Affiliation(s)
- Victòria Ceperuelo-Mallafré
- Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Miriam Ejarque
- Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Carolina Serena
- Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Xavier Duran
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Montori-Grau
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
- Departament de Bioquímica i Biologia Molecular, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Miguel Angel Rodríguez
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
- Centre for Omic Sciences (COS), Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
| | - Oscar Yanes
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
- Department of Electronic Engineering, Universitat Rovira i Virgili, Tarragona, Spain
| | - Catalina Núñez-Roa
- Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Kelly Roche
- Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | | | - Lourdes Garrido-Sánchez
- Hospital Universitario Virgen de la Victoria, Instituto de Investigaciones Biomédicas de Málaga (IBIMA), Universidad de Málaga, IBIMA, Spain
- CIBER de Fisiopatología de Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Enrique Saez
- Department of Chemical Physiology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Francisco J. Tinahones
- Hospital Universitario Virgen de la Victoria, Instituto de Investigaciones Biomédicas de Málaga (IBIMA), Universidad de Málaga, IBIMA, Spain
- CIBER de Fisiopatología de Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Madrid, Spain
| | - Pablo M. Garcia-Roves
- Departamento de Ciencias Fisiológicas II, Facultad de Medicina, Universitat de Barcelona, Barcelona, Spain
| | - Anna Ma Gómez-Foix
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
- Departament de Bioquímica i Biologia Molecular, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Alan R. Saltiel
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Joan Vendrell
- Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
- Corresponding authors. Research Unit, University Hospital of Tarragona Joan XXIII, c/o Dr. Mallafré Guasch, 4, 43007 Tarragona. Spain. Tel.: +34 977 29 58 00; fax: +34 977 29 58 23.
| | - Sonia Fernández-Veledo
- Hospital Universitari de Tarragona Joan XXIII, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Tarragona, Spain
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
- Corresponding authors. Research Unit, University Hospital of Tarragona Joan XXIII, c/o Dr. Mallafré Guasch, 4, 43007 Tarragona. Spain. Tel.: +34 977 29 58 00; fax: +34 977 29 58 23.
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Urschler M, Meidl K, Browning S, Khan B, Milanick M. A kinesthetic activity using LEGO bricks and buckets for illustrating the regulation of blood sugar. ADVANCES IN PHYSIOLOGY EDUCATION 2015; 39:250-252. [PMID: 26330048 DOI: 10.1152/advan.00056.2015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Margaret Urschler
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Katherine Meidl
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Samantha Browning
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Basima Khan
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Mark Milanick
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
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Pedersen AJT, Hingst JR, Friedrichsen M, Kristensen JM, Højlund K, Wojtaszewski JFP. Dysregulation of muscle glycogen synthase in recovery from exercise in type 2 diabetes. Diabetologia 2015; 58:1569-78. [PMID: 25870023 DOI: 10.1007/s00125-015-3582-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 03/13/2015] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS Insulin and exercise stimulate skeletal muscle glycogen synthase (GS) activity by dephosphorylation and changes in kinetic properties. The aim of this study was to investigate the effects of insulin, exercise and post-exercise insulin stimulation on GS phosphorylation, activity and substrate affinity in obesity and type 2 diabetes. METHODS Obese men with type 2 diabetes (n = 13) and weight-matched controls (n = 14) underwent euglycaemic-hyperinsulinaemic clamps in the rested state and 3 h after 60 min of cycling (70% maximal pulmonary oxygen uptake [VO2max]). Biopsies from vastus lateralis muscle were obtained before and after clamps, and before and immediately after exercise. RESULTS Insulin-stimulated glucose uptake was lower in diabetic patients vs obese controls with or without prior exercise. Post exercise, glucose partitioning shifted away from oxidation and towards storage in both groups. Insulin and, more potently, exercise increased GS activity (fractional velocity [FV]) and substrate affinity in both groups. Both stimuli caused dephosphorylation of GS at sites 3a + 3b, with exercise additionally decreasing phosphorylation at sites 2 + 2a. In both groups, changes in GS activity, substrate affinity and dephosphorylation at sites 3a + 3b by exercise were sustained 3 h post exercise and further enhanced by insulin. Post exercise, reduced GS activity and substrate affinity as well as increased phosphorylation at sites 2 + 2a were found in diabetic patients vs obese controls. CONCLUSIONS/INTERPRETATION Exercise-induced activation of muscle GS in obesity and type 2 diabetes involves dephosphorylation of GS at sites 3a + 3b and 2 + 2a and enhanced substrate affinity, which is likely to facilitate glucose partitioning towards storage. Lower GS activity and increased phosphorylation at sites 2 + 2a in type 2 diabetes in the recovery period imply an impaired response to exercise.
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Hodge BA, Wen Y, Riley LA, Zhang X, England JH, Harfmann BD, Schroder EA, Esser KA. The endogenous molecular clock orchestrates the temporal separation of substrate metabolism in skeletal muscle. Skelet Muscle 2015; 5:17. [PMID: 26000164 PMCID: PMC4440511 DOI: 10.1186/s13395-015-0039-5] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 04/13/2015] [Indexed: 01/04/2023] Open
Abstract
Background Skeletal muscle is a major contributor to whole-body metabolism as it serves as a depot for both glucose and amino acids, and is a highly metabolically active tissue. Within skeletal muscle exists an intrinsic molecular clock mechanism that regulates the timing of physiological processes. A key function of the clock is to regulate the timing of metabolic processes to anticipate time of day changes in environmental conditions. The purpose of this study was to identify metabolic genes that are expressed in a circadian manner and determine if these genes are regulated downstream of the intrinsic molecular clock by assaying gene expression in an inducible skeletal muscle-specific Bmal1 knockout mouse model (iMS-Bmal1−/−). Methods We used circadian statistics to analyze a publicly available, high-resolution time-course skeletal muscle expression dataset. Gene ontology analysis was utilized to identify enriched biological processes in the skeletal muscle circadian transcriptome. We generated a tamoxifen-inducible skeletal muscle-specific Bmal1 knockout mouse model and performed a time-course microarray experiment to identify gene expression changes downstream of the molecular clock. Wheel activity monitoring was used to assess circadian behavioral rhythms in iMS-Bmal1−/− and control iMS-Bmal1+/+ mice. Results The skeletal muscle circadian transcriptome was highly enriched for metabolic processes. Acrophase analysis of circadian metabolic genes revealed a temporal separation of genes involved in substrate utilization and storage over a 24-h period. A number of circadian metabolic genes were differentially expressed in the skeletal muscle of the iMS-Bmal1−/− mice. The iMS-Bmal1−/− mice displayed circadian behavioral rhythms indistinguishable from iMS-Bmal1+/+ mice. We also observed a gene signature indicative of a fast to slow fiber-type shift and a more oxidative skeletal muscle in the iMS-Bmal1−/− model. Conclusions These data provide evidence that the intrinsic molecular clock in skeletal muscle temporally regulates genes involved in the utilization and storage of substrates independent of circadian activity. Disruption of this mechanism caused by phase shifts (that is, social jetlag) or night eating may ultimately diminish skeletal muscle’s ability to efficiently maintain metabolic homeostasis over a 24-h period. Electronic supplementary material The online version of this article (doi:10.1186/s13395-015-0039-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Brian A Hodge
- Department of Physiology, College of Medicine, University of Kentucky, MS 508, 800 Rose Street, Lexington, KY 40536 USA ; Center for Muscle Biology, University of Kentucky, 800 Rose Street, Lexington, KY 40536 USA
| | - Yuan Wen
- Department of Physiology, College of Medicine, University of Kentucky, MS 508, 800 Rose Street, Lexington, KY 40536 USA ; Center for Muscle Biology, University of Kentucky, 800 Rose Street, Lexington, KY 40536 USA
| | - Lance A Riley
- Department of Physiology, College of Medicine, University of Kentucky, MS 508, 800 Rose Street, Lexington, KY 40536 USA ; Center for Muscle Biology, University of Kentucky, 800 Rose Street, Lexington, KY 40536 USA
| | - Xiping Zhang
- Department of Physiology, College of Medicine, University of Kentucky, MS 508, 800 Rose Street, Lexington, KY 40536 USA ; Center for Muscle Biology, University of Kentucky, 800 Rose Street, Lexington, KY 40536 USA
| | - Jonathan H England
- Department of Physiology, College of Medicine, University of Kentucky, MS 508, 800 Rose Street, Lexington, KY 40536 USA ; Center for Muscle Biology, University of Kentucky, 800 Rose Street, Lexington, KY 40536 USA
| | - Brianna D Harfmann
- Department of Physiology, College of Medicine, University of Kentucky, MS 508, 800 Rose Street, Lexington, KY 40536 USA ; Center for Muscle Biology, University of Kentucky, 800 Rose Street, Lexington, KY 40536 USA
| | - Elizabeth A Schroder
- Department of Physiology, College of Medicine, University of Kentucky, MS 508, 800 Rose Street, Lexington, KY 40536 USA ; Center for Muscle Biology, University of Kentucky, 800 Rose Street, Lexington, KY 40536 USA
| | - Karyn A Esser
- Department of Physiology, College of Medicine, University of Kentucky, MS 508, 800 Rose Street, Lexington, KY 40536 USA ; Center for Muscle Biology, University of Kentucky, 800 Rose Street, Lexington, KY 40536 USA
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Elberry AA, Harraz FM, Ghareib SA, Gabr SA, Nagy AA, Abdel-Sattar E. Methanolic extract of Marrubium vulgare ameliorates hyperglycemia and dyslipidemia in streptozotocin-induced diabetic rats. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.ijdm.2011.01.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Kolnes AJ, Birk JB, Eilertsen E, Stuenæs JT, Wojtaszewski JFP, Jensen J. Epinephrine-stimulated glycogen breakdown activates glycogen synthase and increases insulin-stimulated glucose uptake in epitrochlearis muscles. Am J Physiol Endocrinol Metab 2015; 308:E231-40. [PMID: 25465888 DOI: 10.1152/ajpendo.00282.2014] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epinephrine increases glycogen synthase (GS) phosphorylation and decreases GS activity but also stimulates glycogen breakdown, and low glycogen content normally activates GS. To test the hypothesis that glycogen content directly regulates GS phosphorylation, glycogen breakdown was stimulated in condition with decreased GS activation. Saline or epinephrine (0.02 mg/100 g rat) was injected subcutaneously in Wistar rats (∼130 g) with low (24-h-fasted), normal (normal diet), and high glycogen content (fasted-refed), and epitrochlearis muscles were removed after 3 h and incubated ex vivo, eliminating epinephrine action. Epinephrine injection reduced glycogen content in epitrochlearis muscles with high (120.7 ± 17.8 vs. 204.6 ± 14.5 mmol/kg, P < 0.01) and normal glycogen (89.5 ± 7.6 vs. 152 ± 8.1 mmol/kg, P < 0.01), but not significantly in muscles with low glycogen (90.0 ± 5.0 vs. 102.8 ± 7.8 mmol/kg, P = 0.17). In saline-injected rats, GS phosphorylation at sites 2+2a, 3a+3b, and 1b was higher and GS activity lower in muscles with high compared with low glycogen. GS sites 2+2a and 3a+3b phosphorylation decreased and GS activity increased in muscles where epinephrine decreased glycogen content; these parameters were unchanged in epitrochlearis from fasted rats where epinephrine injection did not decrease glycogen content. Incubation with insulin decreased GS site 3a+3b phosphorylation independently of glycogen content. Insulin-stimulated glucose uptake was increased in muscles where epinephrine injection decreased glycogen content. In conclusion, epinephrine stimulates glycogenolysis in epitrochlearis muscles with normal and high, but not low, glycogen content. Epinephrine-stimulated glycogenolysis decreased GS phosphorylation and increased GS activity. These data for the first time document direct regulation of GS phosphorylation by glycogen content.
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Affiliation(s)
- Anders J Kolnes
- Charles University Third Faculty of Medicine, Prague, Czech Republic
| | - Jesper B Birk
- Molecular Physiology Group, The August Krogh Centre, Department of Nutrition, Exercise and Sports, Copenhagen University, Copenhagen, Denmark
| | - Einar Eilertsen
- National Institute of Occupational Health, Oslo, Norway; and
| | - Jorid T Stuenæs
- National Institute of Occupational Health, Oslo, Norway; and
| | - Jørgen F P Wojtaszewski
- Molecular Physiology Group, The August Krogh Centre, Department of Nutrition, Exercise and Sports, Copenhagen University, Copenhagen, Denmark
| | - Jørgen Jensen
- Molecular Physiology Group, The August Krogh Centre, Department of Nutrition, Exercise and Sports, Copenhagen University, Copenhagen, Denmark; Department of Physical Performance, Norwegian School of Sports Sciences, Oslo, Norway
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Chandramohan R, Pari L, Rathinam A, Sheikh BA. Tyrosol, a phenolic compound, ameliorates hyperglycemia by regulating key enzymes of carbohydrate metabolism in streptozotocin induced diabetic rats. Chem Biol Interact 2015; 229:44-54. [PMID: 25641191 DOI: 10.1016/j.cbi.2015.01.026] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 01/02/2015] [Accepted: 01/21/2015] [Indexed: 12/23/2022]
Abstract
The present study was designed to evaluate the effects of tyrosol, a phenolic compound, on the activities of key enzymes of carbohydrate metabolism in the control and streptozotocin-induced diabetic rats. Diabetes mellitus was induced in rats by a single intraperitoneal injection of streptozotocin (40 mg/kg body weight). Experimental rats were administered tyrosol 1 ml intra gastrically at the doses of 5, 10 and 20mg/kg body weight and glibenclamide 1 ml at a dose of 600 μg/kg body weight once a day for 45 days. At the end of the experimental period, diabetic control rats exhibited significant (p<0.05) increase in plasma glucose, glycosylated hemoglobin with significant (p<0.05) decrease in plasma insulin, total hemoglobin and body weight. The activities of key enzymes of carbohydrate metabolism such as phosphoenolpyruvate carboxykinase, fructose-1,6-bisphosphatase and glucose-6-phosphatase were significantly (p<0.05) increased and the activities of hexokinase and glucose-6-phosphate dehydrogenase were significantly (p<0.05) decreased in the liver and kidney of diabetic control rats. Further, antioxidants were lowered in diabetic control rats. A significant (p<0.05) decline in glycogen level in the liver and muscle and glycogen synthase activity in the liver and a significant (p<0.05) increase in the activity of liver glycogen phosphorylase were observed in diabetic control rats compared to normal control rats. Oral administration of tyrosol to diabetic rats reversed all the above mentioned biochemical parameters to near normal in a dose dependent manner. Tyrosol at a dose of 20mg/kg body weight showed the highest significant effect than the other two doses. Immunohistochemical staining of pancreas revealed that tyrosol treated diabetic rats showed increased insulin immunoreactive β-cells, which confirmed the biochemical findings. The observed results were compared with glibenclamide, a standard oral hypoglycemic drug. The results of the present study suggest that tyrosol decreases hyperglycemia, by its antioxidant effect.
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Affiliation(s)
- Ramasamy Chandramohan
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| | - Leelavinothan Pari
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar 608002, Tamilnadu, India.
| | - Ayyasamy Rathinam
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| | - Bashir Ahmad Sheikh
- Department of Biochemistry and Biotechnology, Faculty of Science, Annamalai University, Annamalainagar 608002, Tamilnadu, India
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Sato S, Ogura Y, Tajrishi MM, Kumar A. Elevated levels of TWEAK in skeletal muscle promote visceral obesity, insulin resistance, and metabolic dysfunction. FASEB J 2014; 29:988-1002. [PMID: 25466899 DOI: 10.1096/fj.14-260703] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Skeletal muscle is responsible for the majority of glucose disposal in body. Impairment in skeletal muscle glucose handling capacity leads to the state of insulin resistance. The TNF-like weak inducer of apoptosis (TWEAK) cytokine has now emerged as a major regulator of skeletal muscle mass and function. However, the role of TWEAK in skeletal muscle metabolic function remains less understood. Here, we demonstrate that with progressive age, skeletal muscle-specific TWEAK-transgenic (TWEAK-Tg) mice gain increased body weight (∼16%) and fat mass (∼64%) and show glucose intolerance and insulin insensitivity. TWEAK-Tg mice also exhibit adipocyte hypertrophy in the epididymal fat. Oxygen uptake, voluntary physical activity, and exercise capacity were significantly reduced in TWEAK-Tg mice compared with controls. Overexpression of TWEAK inhibited (∼31%) 5' AMP-activated protein kinase (AMPK) and reduced (∼31%) the levels of glucose transporter type 4 (GLUT4) without affecting the Akt pathway. TWEAK also inhibited insulin-stimulated glucose uptake (∼32%) and repressed the levels of GLUT4 (∼50%) in cultured myotubes from C57BL6 mice. TWEAK represses the levels of Krüppel-like factor 15; myocyte enhancer factor 2, and peroxisome proliferator-activated receptor-γ coactivator-1α, which are required for the activation of the GLUT4 locus. Collectively our study demonstrates that elevated levels of TWEAK in skeletal muscle cause metabolic abnormalities. Inhibition of TWEAK could be a potential approach to prevent weight gain and type 2 diabetes.
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Affiliation(s)
- Shuichi Sato
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Yuji Ogura
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Marjan M Tajrishi
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Ashok Kumar
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
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Insulin induces an increase in cytosolic glucose levels in 3T3-L1 cells with inhibited glycogen synthase activation. Int J Mol Sci 2014; 15:17827-37. [PMID: 25279585 PMCID: PMC4227192 DOI: 10.3390/ijms151017827] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/18/2014] [Accepted: 09/19/2014] [Indexed: 12/18/2022] Open
Abstract
Glucose is an important source of energy for mammalian cells and enters the cytosol via glucose transporters. It has been thought for a long time that glucose entering the cytosol is swiftly phosphorylated in most cell types; hence the levels of free glucose are very low, beyond the detection level. However, the introduction of new fluorescence resonance energy transfer-based glucose nanosensors has made it possible to measure intracellular glucose more accurately. Here, we used the fluorescent indicator protein (FLIPglu-600µ) to monitor cytosolic glucose dynamics in mouse 3T3-L1 cells in which glucose utilization for glycogen synthesis was inhibited. The results show that cells exhibit a low resting cytosolic glucose concentration. However, in cells with inhibited glycogen synthase activation, insulin induced a robust increase in cytosolic free glucose. The insulin-induced increase in cytosolic glucose in these cells is due to an imbalance between the glucose transported into the cytosol and the use of glucose in the cytosol. In untreated cells with sensitive glycogen synthase activation, insulin stimulation did not result in a change in the cytosolic glucose level. This is the first report of dynamic measurements of cytosolic glucose levels in cells devoid of the glycogen synthesis pathway.
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Uddin N, Hasan MR, Hossain MM, Sarker A, Hasan AHMN, Islam AFMM, Chowdhury MMH, Rana MS. In vitro α-amylase inhibitory activity and in vivo hypoglycemic effect of methanol extract of Citrus macroptera Montr. fruit. Asian Pac J Trop Biomed 2014; 4:473-9. [PMID: 25182949 DOI: 10.12980/apjtb.4.2014c1173] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 04/12/2014] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE To investigate the therapeutic effects of methanol extract of Citrus macroptera Montr.fruit in α-amylase inhibitory activity (in vitro) and hypoglycemic activity in normal and glucose induced hyperglycemic rats (in vivo). METHODS Fruits of Citrus macroptera without rind was extracted with pure methanol following cold extraction and tested for presence of phytochemical constituents, α-amylase inhibitory activity, and hypoglycemic effect in normal rats and glucose induced hyperglycemic rats. RESULTS Presence of saponin, steroid and terpenoid were identified in the extract. The results showed that fruit extract had moderate α-amylase inhibitory activity [IC50 value=(3.638±0.190) mg/mL] as compared to acarbose. Moreover at 500 mg/kg and 1 000 mg/kg doses fruit extract significantly (P<0.05 and P<0.01 respectively) reduced fasting blood glucose level in normal rats as compared to glibenclamide (5 mg/kg). In oral glucose tolerance test, 500 mg/kg dose significantly reduced blood glucose level (P<0.05) at 2 h but 1 000 mg/kg dose significantly reduced blood glucose level at 2 h and 3 h (P<0.05 and P<0.01 respectively) whereas glibenclamide (5 mg/kg) significantly reduced glucose level at every hour after administration. Overall time effect is also considered extremely significant with F value=23.83 and P value=0.0001 in oral glucose tolerance test. CONCLUSION These findings suggest that the plant may be a potential source for the development of new oral hypoglycemic agent.
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Affiliation(s)
- Nizam Uddin
- Laboratory of Natural Products Research, Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh
| | - Md Rakib Hasan
- Laboratory of Natural Products Research, Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh
| | - Md Monir Hossain
- Laboratory of Natural Products Research, Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh
| | - Arjyabrata Sarker
- Laboratory of Natural Products Research, Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh
| | - A H M Nazmul Hasan
- Laboratory of Natural Products Research, Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh
| | - A F M Mahmudul Islam
- Laboratory of Natural Products Research, Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh
| | - Mohd Motaher H Chowdhury
- Laboratory of Natural Products Research, Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh
| | - Md Sohel Rana
- Laboratory of Natural Products Research, Department of Pharmacy, Jahangirnagar University, Savar, Dhaka-1342, Bangladesh
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42
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von Wilamowitz-Moellendorff A, Hunter RW, García-Rocha M, Kang L, López-Soldado I, Lantier L, Patel K, Peggie MW, Martínez-Pons C, Voss M, Calbó J, Cohen PT, Wasserman DH, Guinovart JJ, Sakamoto K. Glucose-6-phosphate-mediated activation of liver glycogen synthase plays a key role in hepatic glycogen synthesis. Diabetes 2013; 62:4070-82. [PMID: 23990365 PMCID: PMC3837029 DOI: 10.2337/db13-0880] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The liver responds to an increase in blood glucose levels in the postprandial state by uptake of glucose and conversion to glycogen. Liver glycogen synthase (GYS2), a key enzyme in glycogen synthesis, is controlled by a complex interplay between the allosteric activator glucose-6-phosphate (G6P) and reversible phosphorylation through glycogen synthase kinase-3 and the glycogen-associated form of protein phosphatase 1. Here, we initially performed mutagenesis analysis and identified a key residue (Arg(582)) required for activation of GYS2 by G6P. We then used GYS2 Arg(582)Ala knockin (+/R582A) mice in which G6P-mediated GYS2 activation had been profoundly impaired (60-70%), while sparing regulation through reversible phosphorylation. R582A mutant-expressing hepatocytes showed significantly reduced glycogen synthesis with glucose and insulin or glucokinase activator, which resulted in channeling glucose/G6P toward glycolysis and lipid synthesis. GYS2(+/R582A) mice were modestly glucose intolerant and displayed significantly reduced glycogen accumulation with feeding or glucose load in vivo. These data show that G6P-mediated activation of GYS2 plays a key role in controlling glycogen synthesis and hepatic glucose-G6P flux control and thus whole-body glucose homeostasis.
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Affiliation(s)
| | - Roger W. Hunter
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - Mar García-Rocha
- Institute for Research in Biomedicine and Department of Biochemistry and Molecular Biology, University of Barcelona, and CIBERDEM, Barcelona, Spain
| | - Li Kang
- Department of Molecular Physiology and Biophysics and Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Iliana López-Soldado
- Institute for Research in Biomedicine and Department of Biochemistry and Molecular Biology, University of Barcelona, and CIBERDEM, Barcelona, Spain
| | - Louise Lantier
- Department of Molecular Physiology and Biophysics and Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Kashyap Patel
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - Mark W. Peggie
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - Carlos Martínez-Pons
- Institute for Research in Biomedicine and Department of Biochemistry and Molecular Biology, University of Barcelona, and CIBERDEM, Barcelona, Spain
| | - Martin Voss
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - Joaquim Calbó
- Institute for Research in Biomedicine and Department of Biochemistry and Molecular Biology, University of Barcelona, and CIBERDEM, Barcelona, Spain
| | - Patricia T.W. Cohen
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
| | - David H. Wasserman
- Department of Molecular Physiology and Biophysics and Mouse Metabolic Phenotyping Center, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Joan J. Guinovart
- Institute for Research in Biomedicine and Department of Biochemistry and Molecular Biology, University of Barcelona, and CIBERDEM, Barcelona, Spain
| | - Kei Sakamoto
- Medical Research Council Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee, Scotland, U.K
- Corresponding author: Kei Sakamoto,
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43
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Turnbull J, Tiberia E, Pereira S, Zhao X, Pencea N, Wheeler AL, Yu WQ, Ivovic A, Naranian T, Israelian N, Draginov A, Piliguian M, Frankland PW, Wang P, Ackerley CA, Giacca A, Minassian BA. Deficiency of a glycogen synthase-associated protein, Epm2aip1, causes decreased glycogen synthesis and hepatic insulin resistance. J Biol Chem 2013; 288:34627-37. [PMID: 24142699 DOI: 10.1074/jbc.m113.483198] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glycogen synthesis is a major component of the insulin response, and defective glycogen synthesis is a major portion of insulin resistance. Insulin regulates glycogen synthase (GS) through incompletely defined pathways that activate the enzyme through dephosphorylation and, more potently, allosteric activation. We identify Epm2aip1 as a GS-associated protein. We show that the absence of Epm2aip1 in mice impairs allosteric activation of GS by glucose 6-phosphate, decreases hepatic glycogen synthesis, increases liver fat, causes hepatic insulin resistance, and protects against age-related obesity. Our work identifies a novel GS-associated GS activity-modulating component of insulin resistance.
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44
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Maciel RM, Costa MM, Martins DB, França RT, Schmatz R, Graça DL, Duarte MMMF, Danesi CC, Mazzanti CM, Schetinger MRC, Paim FC, Palma HE, Abdala FH, Stefanello N, Zimpel CK, Felin DV, Lopes STA. Antioxidant and anti-inflammatory effects of quercetin in functional and morphological alterations in streptozotocin-induced diabetic rats. Res Vet Sci 2013; 95:389-97. [PMID: 23706762 DOI: 10.1016/j.rvsc.2013.04.028] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Revised: 03/19/2013] [Accepted: 04/25/2013] [Indexed: 11/16/2022]
Abstract
The aim of this study was to investigate functional and morphological alterations caused by oxidative stress in streptozotocin (STZ)-induced diabetic rats and to evaluate the antioxidant effect of quercetin (QUE) in this disease. One hundred and thirty male Wistar rats, it were randomly distributed in 10 different experimental groups, with ten animals per group: Control Saline (CS), Control Ethanol (CE), Control QUE 5mg/kg (CQ5), Control QUE 25mg/kg (CQ25), Control QUE 50mg/kg (CQ50), Diabetic Saline (DS), Diabetic Ethanol (DE), Diabetic QUE 5mg/kg (DQ5), Diabetic QUE25 mg/kg (DQ25), Diabetic QUE 50mg/kg (DQ50). Therefore, hyperglycemia is directly involved in oxidative stress production, as well as in functional and morphological alterations caused by the excess of free radicals. QUE, specially at the dosage of 50mg/kg, can act as an antioxidant and anti-inflammatory agent, becoming a promising adjuvant in the treatment of diabetes mellitus.
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Affiliation(s)
- R M Maciel
- Laboratório de Análises Clínicas Veterinária - LACVet, Universidade Federal de Santa Maria, Av. Roraima no 1000, Cidade Universitária, Bairro Camobi, 97105-900 Santa Maria, RS, Brazil.
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45
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Montori-Grau M, Tarrats N, Osorio-Conles O, Orozco A, Serrano-Marco L, Vázquez-Carrera M, Gómez-Foix AM. Glucose dependence of glycogen synthase activity regulation by GSK3 and MEK/ERK inhibitors and angiotensin-(1-7) action on these pathways in cultured human myotubes. Cell Signal 2013; 25:1318-27. [PMID: 23453973 DOI: 10.1016/j.cellsig.2013.02.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 01/31/2013] [Accepted: 02/13/2013] [Indexed: 11/18/2022]
Abstract
Glycogen synthase (GS) is activated by glucose/glycogen depletion in skeletal muscle cells, but the contributing signaling pathways, including the chief GS regulator GSK3, have not been fully defined. The MEK/ERK pathway is known to regulate GSK3 and respond to glucose. The aim of this study was to elucidate the GSK3 and MEK/ERK pathway contribution to GS activation by glucose deprivation in cultured human myotubes. Moreover, we tested the glucose-dependence of GSK3 and MEK/ERK effects on GS and angiotensin (1-7) actions on these pathways. We show that glucose deprivation activated GS, but did not change phospho-GS (Ser640/1), GSK3β activity or activity-activating phosphorylation of ERK1/2. We then treated glucose-replete and -depleted cells with SB415286, U0126, LY294 and rapamycin to inhibit GSK3, MEK1/2, PI3K and mTOR, respectively. SB415286 activated GS and decreased the relative phospho-GS (Ser640/1) level, more in glucose-depleted than -replete cells. U0126 activated GS and reduced the phospho-GS (Ser640/1) content significantly in glucose-depleted cells, while GSK3β activity tended to increase. LY294 inactivated GS in glucose-depleted cells only, without affecting relative phospho-GS (Ser640/1) level. Rapamycin had no effect on GS activation. Angiotensin-(1-7) raised phospho-ERK1/2 but not phospho-GSK3β (Ser9) content, while it inactivated GS and increased GS phosphorylation on Ser640/1, in glucose-replete cells. In glucose-depleted cells, angiotensin-(1-7) effects on ERK1/2 and GS were reverted, while relative phospho-GSK3β (Ser9) content decreased. In conclusion, activation of GS by glucose deprivation is not due to GS Ser640/1 dephosphorylation, GSK3β or ERK1/2 regulation in cultured myotubes. However, glucose depletion enhances GS activation/Ser640/1 dephosphorylation due to both GSK3 and MEK/ERK inhibition. Angiotensin-(1-7) inactivates GS in glucose-replete cells in association with ERK1/2 activation, not with GSK3 regulation, and glucose deprivation reverts both hormone effects. Thus, the ERK1/2 pathway negatively regulates GS activity in myotubes, without involving GSK3 regulation, and as a function of the presence of glucose.
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Affiliation(s)
- Marta Montori-Grau
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)-Instituto de Salud Carlos III, Spain.
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46
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Abstract
AMPK is an evolutionary conserved sensor of cellular energy status that is activated during exercise. Pharmacological activation of AMPK promotes glucose uptake, fatty acid oxidation, mitochondrial biogenesis, and insulin sensitivity; processes that are reduced in obesity and contribute to the development of insulin resistance. AMPK deficient mouse models have been used to provide direct genetic evidence either supporting or refuting a role for AMPK in regulating these processes. Exercise promotes glucose uptake by an insulin dependent mechanism involving AMPK. Exercise is important for improving insulin sensitivity; however, it is not known if AMPK is required for these improvements. Understanding how these metabolic processes are regulated is important for the development of new strategies that target obesity-induced insulin resistance. This review will discuss the involvement of AMPK in regulating skeletal muscle metabolism (glucose uptake, glycogen synthesis, and insulin sensitivity).
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Affiliation(s)
- Hayley M. O'Neill
- Protein Chemistry and Metabolism Unit, St. Vincent's Institute of Medical Research, Fitzroy, Australia
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47
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Kleinert M, Sylow L, Richter EA. Regulation of glycogen synthase in muscle and its role in Type 2 diabetes. ACTA ACUST UNITED AC 2013. [DOI: 10.2217/dmt.12.54] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Palm DC, Rohwer JM, Hofmeyr JHS. Regulation of glycogen synthase from mammalian skeletal muscle--a unifying view of allosteric and covalent regulation. FEBS J 2012; 280:2-27. [PMID: 23134486 DOI: 10.1111/febs.12059] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 10/29/2012] [Accepted: 11/05/2012] [Indexed: 12/27/2022]
Abstract
It is widely accepted that insufficient insulin-stimulated activation of muscle glycogen synthesis is one of the major components of non-insulin-dependent (type 2) diabetes mellitus. Glycogen synthase, a key enzyme in muscle glycogen synthesis, is extensively regulated, both allosterically (by glucose-6-phosphate, ATP, and others) and covalently (by phosphorylation). Although glycogen synthase has been a topic of intense study for more than 50 years, its kinetic characterization has been confounded by its large number of phosphorylation states. Questions remain regarding the function of glycogen synthase regulation and the relative importance of allosteric and covalent modification in fulfilling this function. In this review, we consider both earlier kinetic studies and more recent site-directed mutagenesis and crystal structure studies in a detailed qualitative discussion of the effects of regulation on the kinetics of glycogen synthase. We propose that both allosteric and covalent modification of glycogen synthase may be described by a Monod-Wyman-Changeux model in terms of apparent changes to L, the equilibrium constant for transition between the T and R conformers. As, with the exception of L, all parameters of this model are independent of the glycogen synthase phosphorylation state, the need to determine kinetic parameters for all possible states is eliminated; only the relationship between a particular state and L must be established. We conclude by suggesting that renewed efforts to characterize the relationship between phosphorylation and the kinetics of glycogen synthase are essential in order to obtain a better quantitative understanding of the function of glycogen synthesis regulation. The model we propose may prove useful in this regard.
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Affiliation(s)
- Daniel C Palm
- Triple J Group for Molecular Cell Physiology, Department of Biochemistry, Stellenbosch University, Stellenbosch, South Africa
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49
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Persistence of inflammatory response to intense exercise in diabetic rats. EXPERIMENTAL DIABETES RESEARCH 2012; 2012:213986. [PMID: 22927832 PMCID: PMC3424703 DOI: 10.1155/2012/213986] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 06/25/2012] [Indexed: 12/26/2022]
Abstract
In this study we evaluated the onset and resolution of inflammation in control and streptozotocin-induced diabetic rats subjected to a single session of intense exercise. The following measurements were carried out prior to, immediately after, and 2 and 24 hours after exercise: plasma levels of proinflammatory cytokines (TNF-α, IL-1β, IL-6, CINC-2α/β, MIP-3α, and IL-6), immunoglobulins (IgA and IgM), acute phase proteins (CRP and C3), and creatine kinase (CK) activity. We also examined the occurrence of macrophage death by measurements of macrophages necrosis (loss of membrane integrity) and DNA fragmentation. An increase was observed in the concentration of IL-1β (3.3-fold) and TNF-α (2.0-fold) and in the proportion of necrotic macrophages (4.5-fold) in diabetic rats 24 hours after exercise, while the control group showed basal measurements. Twenty-four hours after the exercise, serum CK activity was elevated in diabetic rats but not in control animals. We concluded that lesion and inflammations resulting from intense exercise were greater and lasted longer in diabetic animals than in nondiabetic control rats.
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50
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Jensen J, Tantiwong P, Stuenæs JT, Molina-Carrion M, DeFronzo RA, Sakamoto K, Musi N. Effect of acute exercise on glycogen synthase in muscle from obese and diabetic subjects. Am J Physiol Endocrinol Metab 2012; 303:E82-9. [PMID: 22510711 PMCID: PMC3404561 DOI: 10.1152/ajpendo.00658.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulin stimulates glycogen synthase (GS) through dephosphorylation of serine residues, and this effect is impaired in skeletal muscle from insulin-resistant [obese and type 2 diabetic (T2DM)] subjects. Exercise also increases GS activity, yet it is not known whether the ability of exercise to affect GS is impaired in insulin-resistant subjects. The objective of this study was to examine the effect of acute exercise on GS phosphorylation and enzyme kinetic properties in muscle from insulin-resistant individuals. Lean normal glucose-tolerant (NGT), obese NGT, and obese T2DM subjects performed 40 min of moderate-intensity cycle exercise (70% of Vo(2max)). GS kinetic properties and phosphorylation were measured in vastus lateralis muscle before exercise, immediately after exercise, and 3.5 h postexercise. In lean subjects, GS fractional activity increased twofold after 40 min of exercise, and it remained elevated after the 3.5-h rest period. Importantly, exercise also decreased GS K(m) for UDP-glucose from ≈0.5 to ≈0.2 mM. In lean subjects, exercise caused significant dephosphorylation of GS by 50-70% (Ser(641), Ser(645), and Ser(645,649,653,657)), and phosphorylation of these sites remained decreased after 3.5 h; Ser⁷ phosphorylation was not regulated by exercise. In obese NGT and T2DM subjects, exercise increased GS fractional activity, decreased K(m) for UDP-glucose, and decreased GS phosphorylation as effectively as in lean NGT subjects. We conclude that the molecular regulatory process by which exercise promotes glycogen synthesis in muscle is preserved in insulin-resistant subjects.
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Affiliation(s)
- Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sport Sciences, Oslo, Norway
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