1
|
de Souza LC, Moris JM, Lee KM, Fant KH, Gallucci A, Funderburk LK. Dietary Intake and Menstrual Health among Acrobatics and Tumbling NCAA Division I Student-Athletes. JOURNAL OF THE AMERICAN NUTRITION ASSOCIATION 2024; 43:101-109. [PMID: 37307023 DOI: 10.1080/27697061.2023.2218458] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 05/22/2023] [Indexed: 06/13/2023]
Abstract
OBJECTIVE Acrobatics & Tumbling (A&T) is an emerging sport in the National Collegiate Athletic Association that lacks research regarding the dietary intake and health of A&T student-athletes (A&Tsa). This study assessed the dietary intake adequacy, estimated energy availability (EA), self-reported menstrual health, and body composition of A&Tsa. METHODS Twenty-four female A&Tsa participated during week 8 of the preseason (11 top: Age= 20.1 ± 0.9 years; BMI= 22.1 ± 1.7 kg/m2; 13 base: Age= 19.5 ± 1.3 years; BMI= 26.2 ± 2.7 kg/m2). Total energy intake (TEI) and macronutrient intakes were assessed via a paper-based 3-day dietary recall. Resting Metabolic Rate [RMR = 500 + 22 * fat-free mass (FFM)] and energy availability [EA = (TEI - exercise energy expenditure)/FFM)] were estimated; and LEAF-Q assessed menstrual health. Body composition was measured using Dual-Energy X-Ray Absorptiometry. Macronutrient intakes and EA were compared to sports nutrition recommendations (carbohydrate: 6-10 g/kg; protein: 1.2-2.0 g/kg) and the Acceptable Macronutrient Distribution Range (carbohydrate: 45-65%; protein: 10-35%; fat: 20-35%). RESULTS TEI was 1753 ± 467 kcal (top) and 1980 ± 473.8 kcal (base). A total of 20.8% of A&Tsa failed to meet RMR with TEI, with a higher prevalence in the top (-266 ± 219.2 kcal, n = 3) vs. base (-414.3 ± 534.4 kcal, n = 2) A&Tsa. Top and base A&Tsa had both low EA (28.8 ± 13.4 kcals·FFM-1; 23.8 ± 9.5 kcals·FFM-1) and inadequate carbohydrate intake averages (4.2 ± 1.3 g/kg; 3.5 ± 1.1 g/kg, p < 0.001), respectively. A total of 17% of A&Tsa reported secondary amenorrhea, with a higher prevalence in the top (27.3%, n = 3) vs. the base (7.7%, n = 1). CONCLUSION TEI and carbohydrate intake of the majority of A&Tsa were below recommendations. Sports dietitians should encourage and educate A&Tsa about following an adequate diet that meets energy and sports-specific macronutrient needs.
Collapse
Affiliation(s)
- Leticia C de Souza
- Department of Health, Human Performance, and Recreation, Baylor University, Waco, Texas, USA
| | - Jose M Moris
- Department of Health, Human Performance, and Recreation, Baylor University, Waco, Texas, USA
| | - Katherine M Lee
- Department of Health, Human Performance, and Recreation, Baylor University, Waco, Texas, USA
| | - Kristin H Fant
- Performance Nutrition (Baylor Athletics), Baylor University, Waco, Texas, USA
| | - Andrew Gallucci
- Department of Health, Human Performance, and Recreation, Baylor University, Waco, Texas, USA
| | - LesLee K Funderburk
- Department of Health, Human Performance, and Recreation, Baylor University, Waco, Texas, USA
- Department of Human Sciences and Design, Baylor University, Waco, Texas, USA
| |
Collapse
|
2
|
Grapentine S, Singh RK, Bakovic M. Skeletal Muscle Consequences of Phosphatidylethanolamine Synthesis Deficiency. FUNCTION 2023; 4:zqad020. [PMID: 37342414 PMCID: PMC10278983 DOI: 10.1093/function/zqad020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 06/22/2023] Open
Abstract
The maintenance of phospholipid homeostasis is increasingly being implicated in metabolic health. Phosphatidylethanolamine (PE) is the most abundant phospholipid on the inner leaflet of cellular membranes, and we have previously shown that mice with a heterozygous ablation of the PE synthesizing enzyme, Pcyt2 (Pcyt2+/-), develop obesity, insulin resistance, and NASH. Skeletal muscle is a major determinant of systemic energy metabolism, making it a key player in metabolic disease development. Both the total PE levels and the ratio of PE to other membrane lipids in skeletal muscle are implicated in insulin resistance; however, the underlying mechanisms and the role of Pcyt2 regulation in this association remain unclear. Here, we show how reduced phospholipid synthesis due to Pcyt2 deficiency causes Pcyt2+/- skeletal muscle dysfunction and metabolic abnormalities. Pcyt2+/- skeletal muscle exhibits damage and degeneration, with skeletal muscle cell vacuolization, disordered sarcomeres, mitochondria ultrastructure irregularities and paucity, inflammation, and fibrosis. There is intramuscular adipose tissue accumulation, and major disturbances in lipid metabolism with impaired FA mobilization and oxidation, elevated lipogenesis, and long-chain fatty acyl-CoA, diacylglycerol, and triacylglycerol accumulation. Pcyt2+/- skeletal muscle exhibits perturbed glucose metabolism with elevated glycogen content, impaired insulin signaling, and reduced glucose uptake. Together, this study lends insight into the critical role of PE homeostasis in skeletal muscle metabolism and health with broad implications on metabolic disease development.
Collapse
Affiliation(s)
- Sophie Grapentine
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph N1G 2W1, Canada
| | - Rathnesh K Singh
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph N1G 2W1, Canada
| | - Marica Bakovic
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph N1G 2W1, Canada
| |
Collapse
|
3
|
Hingst JR, Onslev JD, Holm S, Kjøbsted R, Frøsig C, Kido K, Steenberg DE, Larsen MR, Kristensen JM, Carl CS, Sjøberg K, Thong FSL, Derave W, Pehmøller C, Brandt N, McConell G, Jensen J, Kiens B, Richter EA, Wojtaszewski JFP. Insulin Sensitization Following a Single Exercise Bout Is Uncoupled to Glycogen in Human Skeletal Muscle: A Meta-analysis of 13 Single-Center Human Studies. Diabetes 2022; 71:2237-2250. [PMID: 36265014 DOI: 10.2337/db22-0015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 08/18/2022] [Indexed: 11/13/2022]
Abstract
Exercise profoundly influences glycemic control by enhancing muscle insulin sensitivity, thus promoting glucometabolic health. While prior glycogen breakdown so far has been deemed integral for muscle insulin sensitivity to be potentiated by exercise, the mechanisms underlying this phenomenon remain enigmatic. We have combined original data from 13 of our studies that investigated insulin action in skeletal muscle either under rested conditions or following a bout of one-legged knee extensor exercise in healthy young male individuals (n = 106). Insulin-stimulated glucose uptake was potentiated and occurred substantially faster in the prior contracted muscles. In this otherwise homogenous group of individuals, a remarkable biological diversity in the glucometabolic responses to insulin is apparent both in skeletal muscle and at the whole-body level. In contrast to the prevailing concept, our analyses reveal that insulin-stimulated muscle glucose uptake and the potentiation thereof by exercise are not associated with muscle glycogen synthase activity, muscle glycogen content, or degree of glycogen utilization during the preceding exercise bout. Our data further suggest that the phenomenon of improved insulin sensitivity in prior contracted muscle is not regulated in a homeostatic feedback manner from glycogen. Instead, we put forward the idea that this phenomenon is regulated by cellular allostatic mechanisms that elevate the muscle glycogen storage set point and enhance insulin sensitivity to promote the uptake of glucose toward faster glycogen resynthesis without development of glucose overload/toxicity or feedback inhibition.
Collapse
Affiliation(s)
- Janne R Hingst
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Johan D Onslev
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Stephanie Holm
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Rasmus Kjøbsted
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Christian Frøsig
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Kohei Kido
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Dorte E Steenberg
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Magnus R Larsen
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jonas M Kristensen
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Christian Strini Carl
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Kim Sjøberg
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Farah S L Thong
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Wim Derave
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Department of Movement and Sports Sciences, Ghent University, Ghent, Belgium
| | - Christian Pehmøller
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Nina Brandt
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Glenn McConell
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Institute for Health and Sport, Victoria University, Melbourne, Australia
| | - Jørgen Jensen
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
- Department of Physical Performance, Norwegian School of Sports Sciences, Oslo, Norway
| | - Bente Kiens
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Erik A Richter
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen F P Wojtaszewski
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
4
|
Wang ZJ, Bai Z, Yan JH, Liu TT, Li YM, Xu JH, Meng XQ, Bi YF. Anti-diabetic effects of linarin from Chrysanthemi Indici Flos via AMPK activation. CHINESE HERBAL MEDICINES 2021; 14:97-103. [PMID: 36120128 PMCID: PMC9476778 DOI: 10.1016/j.chmed.2021.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 04/08/2021] [Accepted: 08/05/2021] [Indexed: 11/08/2022] Open
Abstract
Objective The purpose of this study is to investigate the anti-diabetic effects of linarin, a flavonoid extracted from Chrysanthemi Indici Flos (CIF), and its potential mechanisms. Methods The effects of linarin on cell viability and glucose consumption in HepG2 cells were measured. Meanwhile, monosodium glutamate (MSG) mouse model was constructed to monitor the changes of insulin tolerance, glucose tolerance, triglyceride and cholesterol. The protein expression levels of p-AMPK, p-ACC, PEPCK and p-GS were detected by Western blot. Results Linarin could increase the relative glucose consumption of HepG2 cells, improve insulin tolerance and glucose tolerance, and decrease the levels of triglyceride and cholesterol of MSG mice. Simultaneously, the expression levels of p-AMPK and p-ACC in HepG2 cells and the liver tissue of MSG mice were increased, while the expression levels of PEPCK and p-GS were decreased after treatment with linarin. Conclusion Insulin resistance could be ameliorated by linarin in type 2 diabetes, and its mechanism may be related to AMPK signaling pathway.
Collapse
|
5
|
Loureiro LMR, dos Santos Neto E, Molina GE, Amato AA, Arruda SF, Reis CEG, da Costa THM. Coffee Increases Post-Exercise Muscle Glycogen Recovery in Endurance Athletes: A Randomized Clinical Trial. Nutrients 2021; 13:nu13103335. [PMID: 34684336 PMCID: PMC8537367 DOI: 10.3390/nu13103335] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/14/2021] [Accepted: 09/16/2021] [Indexed: 11/16/2022] Open
Abstract
Coffee is one of the most widely consumed beverages worldwide and caffeine is known to improve performance in physical exercise. Some substances in coffee have a positive effect on glucose metabolism and are promising for post-exercise muscle glycogen recovery. We investigated the effect of a coffee beverage after exhaustive exercise on muscle glycogen resynthesis, glycogen synthase activity and glycemic and insulinemic response in a double-blind, crossover, randomized clinical trial. Fourteen endurance-trained men performed an exhaustive cycle ergometer exercise to deplete muscle glycogen. The following morning, participants completed a second cycling protocol followed by a 4-h recovery, during which they received either test beverage (coffee + milk) or control (milk) and a breakfast meal, with a simple randomization. Blood samples and muscle biopsies were collected at the beginning and by the end of recovery. Eleven participants were included in data analysis (age: 39.0 ± 6.0 years; BMI: 24.0 ± 2.3 kg/m2; VO2max: 59.9 ± 8.3 mL·kg−1·min−1; PPO: 346 ± 39 W). The consumption of coffee + milk resulted in greater muscle glycogen recovery (102.56 ± 18.75 vs. 40.54 ± 18.74 mmol·kg dw−1; p = 0.01; d = 0.94) and greater glucose (p = 0.02; d = 0.83) and insulin (p = 0.03; d = 0.76) total area under the curve compared with control. The addition of coffee to a beverage with adequate amounts of carbohydrates increased muscle glycogen resynthesis and the glycemic and insulinemic response during the 4-h recovery after exhaustive cycling exercise.
Collapse
Affiliation(s)
| | - Eugênio dos Santos Neto
- Health Sciences Graduate Program, Faculty of Health Sciences and Faculty of Medicine, Universidade de Brasilia, Brasilia 70910-900, Brazil;
| | - Guilherme Eckhardt Molina
- Exercise Physiology Laboratory, Faculty of Physical Education, Universidade de Brasilia, Brasilia 70910-900, Brazil;
| | - Angélica Amorim Amato
- Molecular Pharmacology Laboratory, Department of Pharmaceutical Sciences, Faculty of Health Sciences, Universidade de Brasília, Brasilia 70910-900, Brazil;
| | - Sandra Fernandes Arruda
- Nutritional Biochemistry Laboratory, Department of Nutrition, Universidade de Brasília, Brasilia 70910-900, Brazil; (S.F.A.); (C.E.G.R.)
| | - Caio Eduardo Gonçalves Reis
- Nutritional Biochemistry Laboratory, Department of Nutrition, Universidade de Brasília, Brasilia 70910-900, Brazil; (S.F.A.); (C.E.G.R.)
| | - Teresa Helena Macedo da Costa
- Nutritional Biochemistry Laboratory, Department of Nutrition, Universidade de Brasília, Brasilia 70910-900, Brazil; (S.F.A.); (C.E.G.R.)
- Correspondence: ; Tel.: +55-(61)-3107-0092
| |
Collapse
|
6
|
Abstract
As the principal tissue for insulin-stimulated glucose disposal, skeletal muscle is a primary driver of whole-body glycemic control. Skeletal muscle also uniquely responds to muscle contraction or exercise with increased sensitivity to subsequent insulin stimulation. Insulin's dominating control of glucose metabolism is orchestrated by complex and highly regulated signaling cascades that elicit diverse and unique effects on skeletal muscle. We discuss the discoveries that have led to our current understanding of how insulin promotes glucose uptake in muscle. We also touch upon insulin access to muscle, and insulin signaling toward glycogen, lipid, and protein metabolism. We draw from human and rodent studies in vivo, isolated muscle preparations, and muscle cell cultures to home in on the molecular, biophysical, and structural elements mediating these responses. Finally, we offer some perspective on molecular defects that potentially underlie the failure of muscle to take up glucose efficiently during obesity and type 2 diabetes.
Collapse
|
7
|
Murphy RM, Watt MJ, Febbraio MA. Metabolic communication during exercise. Nat Metab 2020; 2:805-816. [PMID: 32747791 DOI: 10.1038/s42255-020-0258-x] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/02/2020] [Indexed: 12/22/2022]
Abstract
The coordination of nutrient sensing, delivery, uptake and utilization is essential for maintaining cellular, tissue and whole-body homeostasis. Such synchronization can be achieved only if metabolic information is communicated between the cells and tissues of the entire organism. During intense exercise, the metabolic demand of the body can increase approximately 100-fold. Thus, exercise is a physiological state in which intertissue communication is of paramount importance. In this Review, we discuss the physiological processes governing intertissue communication during exercise and the molecules mediating such cross-talk.
Collapse
Affiliation(s)
- Robyn M Murphy
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - Matthew J Watt
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Mark A Febbraio
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia.
| |
Collapse
|
8
|
Akmali A, Saghebjoo M. High-intensity interval training with long duration intervals is more effective than short duration intervals for improving glycolytic capacity in the rats' gastrocnemius muscle. Horm Mol Biol Clin Investig 2019; 41:hmbci-2019-0035. [PMID: 31628826 DOI: 10.1515/hmbci-2019-0035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/09/2019] [Indexed: 11/15/2022]
Abstract
Background There is little data regarding the ability of high-intensity interval training (HIIT) to increase of glycolytic capacity and intramuscular metabolic adaptations. The goal of this study was to evaluate the effects of HIIT (8 weeks, 5 times/week) with short (HIIT1 min: 16 × 1 min work and active recovery at 80-95% and 50-60% VO2max, respectively) and long (HIIT4 min: 4 × 4 min work and active recovery at 80-95% and 50-60% VO2max, respectively) duration intervals and 4 weeks detraining on the levels of phosphofructokinase (PFK), glycogen synthase 1 (GYS1), monocarboxylate transporter 4 (MCT4) and lactate dehydrogenase (LDH) activity in the rats' gastrocnemius muscle. Materials and methods Fifty-four male Wistar rats were assigned into three groups, including HIIT1 min, HIIT4 min and control (Ctrl). After 48 h of the last training session and after 4 weeks of detraining, the rats were sacrificed, and the gastrocnemius muscles were isolated. Results The PFK levels in the HIIT4 min group was significantly higher than in the HIIT1 min and Ctrl groups, and after the detraining period in the HIIT4 minDT group significantly decreased compared to the HIIT4 min group. The LDH activity in the HIIT4 min and HIIT1 min groups were significantly higher than the Ctrl group and the increasing trend in the HIIT4 min group was more than the HIIT1 min group. There was no significant change in LDH activity after detraining compared to training. No significant changes were observed in the level of GYS1 and MCT4 after HIIT. Conclusions Eight weeks of HIIT with long duration intervals induced more improvements in intramuscular glycolytic capacity than a short duration. After short-term detraining, some of these adaptations have remained.
Collapse
Affiliation(s)
- Azadeh Akmali
- Department of Exercise Physiology, Faculty of Sport Sciences, University of Birjand, Birjand, Iran
| | - Marziyeh Saghebjoo
- Department of Exercise Physiology, Faculty of Sport Sciences, University of Birjand, Birjand, Iran
| |
Collapse
|
9
|
Pederson BA. Structure and Regulation of Glycogen Synthase in the Brain. ADVANCES IN NEUROBIOLOGY 2019; 23:83-123. [PMID: 31667806 DOI: 10.1007/978-3-030-27480-1_3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Brain glycogen synthesis is a regulated, multi-step process that begins with glucose transport across the blood brain barrier and culminates with the actions of glycogen synthase and the glycogen branching enzyme to elongate glucose chains and introduce branch points in a growing glycogen molecule. This review focuses on the synthesis of glycogen in the brain, with an emphasis on glycogen synthase, but draws on salient studies in mammalian muscle and liver as well as baker's yeast, with the goal of providing a more comprehensive view of glycogen synthesis and highlighting potential areas for further study in the brain. In addition, deficiencies in the glycogen biosynthetic enzymes which lead to glycogen storage diseases in humans are discussed, highlighting effects on the brain and discussing findings in genetically modified animal models that recapitulate these diseases. Finally, implications of glycogen synthesis in neurodegenerative and other diseases that impact the brain are presented.
Collapse
|
10
|
Brewer MK, Gentry MS. Brain Glycogen Structure and Its Associated Proteins: Past, Present and Future. ADVANCES IN NEUROBIOLOGY 2019; 23:17-81. [PMID: 31667805 PMCID: PMC7239500 DOI: 10.1007/978-3-030-27480-1_2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This chapter reviews the history of glycogen-related research and discusses in detail the structure, regulation, chemical properties and subcellular distribution of glycogen and its associated proteins, with particular focus on these aspects in brain tissue.
Collapse
Affiliation(s)
- M Kathryn Brewer
- Department of Molecular and Cellular Biochemistry, Epilepsy and Brain Metabolism Center, Lafora Epilepsy Cure Initiative, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, Epilepsy and Brain Metabolism Center, Lafora Epilepsy Cure Initiative, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, USA.
| |
Collapse
|
11
|
Effects of Coffee Components on Muscle Glycogen Recovery: A Systematic Review. Int J Sport Nutr Exerc Metab 2018; 28:284-293. [PMID: 29345166 DOI: 10.1123/ijsnem.2017-0342] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Coffee is one of the most consumed beverages in the world, and it can improve insulin sensitivity, stimulating glucose uptake in skeletal muscle when adequate carbohydrate intake is observed. The aim of this review is to analyze the effects of coffee and coffee components on muscle glycogen metabolism. A literature search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis, and seven studies were included, that explored the effects of coffee components on various substances and signaling proteins. In one of the studies with humans, caffeine was shown to increase glucose levels, Ca2+/calmodulin-dependent protein kinase phosphorylation, glycogen resynthesis rates, and glycogen accumulation after exercise. After intravenous injection of caffeine in rats, caffeine increased adenosine monophosphate-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) phosphorylation, and glucose transport. In in vitro studies, caffeine raised AMPK and ACC phosphorylation, increasing glucose transport activity and reducing energy status in rat muscle cells. Cafestol and caffeic acid increased insulin secretion in rat beta cells and glucose uptake into human muscle cells. Caffeic acid also increased AMPK and ACC phosphorylation, reducing the energy status and increasing glucose uptake in rat muscle cells. Chlorogenic acid did not show any positive or negative effect. The findings from this review must be taken with caution due to the limited number of studies on the subject. In conclusion, various coffee components had a neutral or positive role in the metabolism of glucose and muscle glycogen, whereas no detrimental effect was described. Coffee beverages should be tested as an option for athletes' glycogen recovery.
Collapse
|
12
|
Montori-Grau M, Pedreira-Casahuga R, Boyer-Díaz Z, Lassot I, García-Martínez C, Orozco A, Cebrià J, Osorio-Conles O, Chacón MR, Vendrell J, Vázquez-Carrera M, Desagher S, Jiménez-Chillarón JC, Gómez-Foix AM. GNIP1 E3 ubiquitin ligase is a novel player in regulating glycogen metabolism in skeletal muscle. Metabolism 2018; 83:177-187. [PMID: 29466708 DOI: 10.1016/j.metabol.2018.02.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/09/2018] [Accepted: 02/15/2018] [Indexed: 12/23/2022]
Abstract
BACKGROUND Glycogenin-interacting protein 1 (GNIP1) is a tripartite motif (TRIM) protein with E3 ubiquitin ligase activity that interacts with glycogenin. These data suggest that GNIP1 could play a major role in the control of glycogen metabolism. However, direct evidence based on functional analysis remains to be obtained. OBJECTIVES The aim of this study was 1) to define the expression pattern of glycogenin-interacting protein/Tripartite motif containing protein 7 (GNIP/TRIM7) isoforms in humans, 2) to test their ubiquitin E3 ligase activity, and 3) to analyze the functional effects of GNIP1 on muscle glucose/glycogen metabolism both in human cultured cells and in vivo in mice. RESULTS We show that GNIP1 was the most abundant GNIP/TRIM7 isoform in human skeletal muscle, whereas in cardiac muscle only TRIM7 was expressed. GNIP1 and TRIM7 had autoubiquitination activity in vitro and were localized in the Golgi apparatus and cytosol respectively in LHCN-M2 myoblasts. GNIP1 overexpression increased glucose uptake in LHCN-M2 myotubes. Overexpression of GNIP1 in mouse muscle in vivo increased glycogen content, glycogen synthase (GS) activity and phospho-GSK-3α/β (Ser21/9) and phospho-Akt (Ser473) content, whereas decreased GS phosphorylation in Ser640. These modifications led to decreased blood glucose levels, lactate levels and body weight, without changing whole-body insulin or glucose tolerance in mouse. CONCLUSION GNIP1 is an ubiquitin ligase with a markedly glycogenic effect in skeletal muscle.
Collapse
Affiliation(s)
- Marta Montori-Grau
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Institut de Recerca Sant Joan de Déu (IRSJD), Esplugues de Llobregat, Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)-Instituto de Salud Carlos III, Spain; Departament de Farmacologia, Toxicologia i Química Terapéutica, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Spain.
| | - Robert Pedreira-Casahuga
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Spain
| | - Zoé Boyer-Díaz
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Spain
| | - Iréna Lassot
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Celia García-Martínez
- Departament de Patologia i Terapèutica Experimental, UB, Hospitalet de Llobregat, Barcelona, Spain
| | - Anna Orozco
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Spain
| | - Judith Cebrià
- Institut de Recerca Sant Joan de Déu (IRSJD), Esplugues de Llobregat, Barcelona, Spain; Endocrine Division, Esplugues de Llobregat, Barcelona, Spain
| | - Oscar Osorio-Conles
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Spain
| | - Matilde R Chacón
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)-Instituto de Salud Carlos III, Spain; Hospital Universitari de Tarragona Joan XXIII, Universitat Rovira i Virgili, IISPV, Tarragona, Spain
| | - Joan Vendrell
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)-Instituto de Salud Carlos III, Spain; Hospital Universitari de Tarragona Joan XXIII, Universitat Rovira i Virgili, IISPV, Tarragona, Spain
| | - Manuel Vázquez-Carrera
- Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; Institut de Recerca Sant Joan de Déu (IRSJD), Esplugues de Llobregat, Barcelona, Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)-Instituto de Salud Carlos III, Spain; Departament de Farmacologia, Toxicologia i Química Terapéutica, Facultat de Farmàcia i Ciències de l'Alimentació, Universitat de Barcelona, Spain
| | - Solange Desagher
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Josep Carles Jiménez-Chillarón
- Institut de Recerca Sant Joan de Déu (IRSJD), Esplugues de Llobregat, Barcelona, Spain; Endocrine Division, Esplugues de Llobregat, Barcelona, Spain
| | - Anna Ma Gómez-Foix
- Departament de Bioquímica i Biomedicina Molecular, Facultat de Biologia, Universitat de Barcelona, Spain; Institut de Biomedicina de la Universitat de Barcelona (IBUB), Spain; CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM)-Instituto de Salud Carlos III, Spain
| |
Collapse
|
13
|
Metabolic and molecular changes associated with the increased skeletal muscle insulin action 24-48 h after exercise in young and old humans. Biochem Soc Trans 2018; 46:111-118. [PMID: 29330356 DOI: 10.1042/bst20170198] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 11/23/2017] [Accepted: 11/24/2017] [Indexed: 12/25/2022]
Abstract
The molecular and metabolic mechanisms underlying the increase in insulin sensitivity (i.e. increased insulin-stimulated skeletal muscle glucose uptake, phosphorylation and storage as glycogen) observed from 12 to 48 h following a single bout of exercise in humans remain unresolved. Moreover, whether these mechanisms differ with age is unclear. It is well established that a single bout of exercise increases the translocation of the glucose transporter, GLUT4, to the plasma membrane. Previous research using unilateral limb muscle contraction models in combination with hyperinsulinaemia has demonstrated that the increase in insulin sensitivity and glycogen synthesis 24 h after exercise is also associated with an increase in hexokinase II (HKII) mRNA and protein content, suggesting an increase in the capacity of the muscle to phosphorylate glucose and divert it towards glycogen synthesis. Interestingly, this response is altered in older individuals for up to 48 h post exercise and is associated with molecular changes in skeletal muscle tissue that are indicative of reduced lipid oxidation, increased lipogenesis, increased inflammation and a relative inflexibility of changes in intramyocellular lipid (IMCL) content. Reduced insulin sensitivity (insulin resistance) is generally related to IMCL content, particularly in the subsarcolemmal (SSL) region, and both are associated with increasing age. Recent research has demonstrated that ageing per se appears to cause an exacerbated lipolytic response to exercise that may result in SSL IMCL accumulation. Further research is required to determine if increased IMCL content affects HKII expression in the days after exercise in older individuals, and the effect of this on skeletal muscle insulin action.
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
The interaction between AMPKβ2 and the PP1-targeting subunit R6 is dynamically regulated by intracellular glycogen content. Biochem J 2016; 473:937-47. [DOI: 10.1042/bj20151035] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 02/01/2016] [Indexed: 11/17/2022]
Abstract
Breakdown of intracellular glycogen enhances interaction of the AMPKβ2 subunit and the R6 glycogen-targeting subunit of protein phosphatase type 1 (PP1), which occurs in conjunction with increased β2-Thr-148 phosphorylation.
Collapse
|
16
|
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.
Collapse
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
| |
Collapse
|
17
|
Parallel Evolution of the Glycogen Synthase 1 (Muscle) Gene Gys1 Between Old World and New World Fruit Bats (Order: Chiroptera). Biochem Genet 2014; 52:443-58. [DOI: 10.1007/s10528-014-9659-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 06/06/2014] [Indexed: 01/09/2023]
|
18
|
Campbell MD, Walker M, Trenell MI, Jakovljevic DG, Stevenson EJ, Bracken RM, Bain SC, West DJ. Large pre- and postexercise rapid-acting insulin reductions preserve glycemia and prevent early- but not late-onset hypoglycemia in patients with type 1 diabetes. Diabetes Care 2013; 36:2217-24. [PMID: 23514728 PMCID: PMC3714511 DOI: 10.2337/dc12-2467] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To examine the acute and 24-h glycemic responses to reductions in postexercise rapid-acting insulin dose in type 1 diabetic patients. RESEARCH DESIGN AND METHODS After preliminary testing, 11 male patients (24 ± 2 years, HbA1c 7.7 ± 0.3%; 61 ± 3.4 mmol/mol) attended the laboratory on three mornings. Patients consumed a standardized breakfast (1 g carbohydrate · kg(-1) BM; 380 ± 10 kcal) and self-administered a 25% rapid-acting insulin dose 60 min prior to performing 45 min of treadmill running at 72.5 ± 0.9% VO2peak. At 60 min postexercise, patients ingested a meal (1 g carbohydrate · kg(-1) BM; 660 ± 21 kcal) and administered a Full, 75%, or 50% rapid-acting insulin dose. Blood glucose concentrations were measured for 3 h postmeal. Interstitial glucose was recorded for 20 h after leaving the laboratory using a continuous glucose monitoring system. RESULTS All glycemic responses were similar across conditions up to 60 min postexercise. After the postexercise meal, blood glucose was preserved under 50%, but declined under Full and 75%. Thence at 3 h, blood glucose was highest under 50% (50% [10.4 ± 1.2] vs. Full [6.2 ± 0.7] and 75% [7.6 ± 1.2 mmol · L(-1)], P = 0.029); throughout this period, all patients were protected against hypoglycemia under 50% (blood glucose ≤ 3.9; Full, n = 5; 75%, n = 2; 50%, n = 0). Fifty percent continued to protect patients against hypoglycemia for a further 4 h under free-living conditions. However, late-evening and nocturnal glycemia were similar; as a consequence, late-onset hypoglycemia was experienced under all conditions. CONCLUSIONS A 25% pre-exercise and 50% postexercise rapid-acting insulin dose preserves glycemia and protects patients against early-onset hypoglycemia (≤ 8 h). However, this strategy does not protect against late-onset postexercise hypoglycemia.
Collapse
|
19
|
Farlinger CM, Lui AJ, Harrison RC, LeBlanc PJ, Peters SJ, Roy BD. Extracellular hyperosmotic stress stimulates glucose uptake in incubated fast-twitch rat skeletal muscle. Appl Physiol Nutr Metab 2013; 38:605-12. [DOI: 10.1139/apnm-2012-0236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The influence of hyperosmotic stress on glucose uptake, handling, and signaling processes remains unclear in mammalian skeletal muscle. Thus, the purpose of this study was to investigate alterations in glucose uptake and handling during extracellular hyperosmotic stress in isolated fast-twitch mammalian skeletal muscle. Using an established in vitro isolated whole-muscle model, extensor digitorum longus (EDL) muscles were dissected from male rats (4–6 weeks of age) and incubated (30–60 min) in an organ bath, containing Sigma Medium-199 with 8 mmol·L−1D-glucose, and mannitol was added to the targeted osmolalities (ISO, iso-osmotic, 290 mmol·kg−1; HYPER, hyperosmotic, 400 mmol·kg−1). Results demonstrate that relative water content decreased in HYPER. HYPER resulted in significant alterations in muscle metabolite concentrations (lower glycogen, elevated lactate, and glucose-6-phosphate), suggesting a decrease in energy charge. Glucose uptake was also found to be higher in HYPER, and AS160 (implicated in insulin- and contraction-mediated glucose uptake) was found to be significantly more phosphorylated in HYPER than in ISO after 30 min. In conclusion, glucose uptake and handling is altered with hyperosmotic extracellular stress in the fast-twitch EDL. The increases in glucose uptake might be facilitated through alterations in AS160 signaling after 30 to 60 min of osmotic stress.
Collapse
Affiliation(s)
- Chris M. Farlinger
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Adrian J. Lui
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Rose C. Harrison
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Paul J. LeBlanc
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada; Department of Community Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Sandra J. Peters
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada; Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Brian D. Roy
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada; Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada; Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| |
Collapse
|
20
|
Stapleton D, Nelson C, Parsawar K, Flores-Opazo M, McClain D, Parker G. The 3T3-L1 adipocyte glycogen proteome. Proteome Sci 2013; 11:11. [PMID: 23521774 PMCID: PMC3622581 DOI: 10.1186/1477-5956-11-11] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 03/04/2013] [Indexed: 01/10/2023] Open
Abstract
Background Glycogen is a branched polysaccharide of glucose residues, consisting of α-1-4 glycosidic linkages with α-1-6 branches that together form multi-layered particles ranging in size from 30 nm to 300 nm. Glycogen spatial conformation and intracellular organization are highly regulated processes. Glycogen particles interact with their metabolizing enzymes and are associated with a variety of proteins that intervene in its biology, controlling its structure, particle size and sub-cellular distribution. The function of glycogen in adipose tissue is not well understood but appears to have a pivotal role as a regulatory mechanism informing the cells on substrate availability for triacylglycerol synthesis. To provide new molecular insights into the role of adipocyte glycogen we analyzed the glycogen-associated proteome from differentiated 3T3-L1-adipocytes. Results Glycogen particles from 3T3-L1-adipocytes were purified using a series of centrifugation steps followed by specific elution of glycogen bound proteins using α-1,4 glucose oligosaccharides, or maltodextrins, and tandem mass spectrometry. We identified regulatory proteins, 14-3-3 proteins, RACK1 and protein phosphatase 1 glycogen targeting subunit 3D. Evidence was also obtained for a regulated subcellular distribution of the glycogen particle: metabolic and mitochondrial proteins were abundant. Unlike the recently analyzed hepatic glycogen proteome, no endoplasmic proteins were detected, along with the recently described starch-binding domain protein 1. Other regulatory proteins which have previously been described as glycogen-associated proteins were not detected, including laforin, the AMPK beta-subunit and protein targeting to glycogen (PTG). Conclusions These data provide new molecular insights into the regulation of glycogen-bound proteins that are associated with the maintenance, organization and localization of the adipocyte glycogen particle.
Collapse
Affiliation(s)
- David Stapleton
- University of Utah School of Medicine, Rm 4C464B SOM, 30 N 1900 E, Salt Lake City, Utah 84132, USA.
| | | | | | | | | | | |
Collapse
|
21
|
Nielsen J, Ørtenblad N. Physiological aspects of the subcellular localization of glycogen in skeletal muscle. Appl Physiol Nutr Metab 2013; 38:91-9. [DOI: 10.1139/apnm-2012-0184] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Glucose is stored in skeletal muscle fibers as glycogen, a branched-chain polymer observed in electron microscopy images as roughly spherical particles (known as β-particles of 10–45 nm in diameter), which are distributed in distinct localizations within the myofibers and are physically associated with metabolic and scaffolding proteins. Although the subcellular localization of glycogen has been recognized for more than 40 years, the physiological role of the distinct localizations has received sparse attention. Recently, however, studies involving stereological, unbiased, quantitative methods have investigated the role and regulation of these distinct deposits of glycogen. In this report, we review the available literature regarding the subcellular localization of glycogen in skeletal muscle as investigated by electron microscopy studies and put this into perspective in terms of the architectural, topological, and dynamic organization of skeletal muscle fibers. In summary, the distribution of glycogen within skeletal muscle fibers has been shown to depend on the fiber phenotype, individual training status, short-term immobilization, and exercise and to influence both muscle contractility and fatigability. Based on all these data, the available literature strongly indicates that the subcellular localization of glycogen has to be taken into consideration to fully understand and appreciate the role and regulation of glycogen metabolism and signaling in skeletal muscle. A full understanding of these phenomena may prove vital in elucidating the mechanisms that integrate basic cellular events with changing glycogen content.
Collapse
Affiliation(s)
- Joachim Nielsen
- SDU Muscle Research Cluster (SMRC), Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark; Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 83125 Östersund, Sweden
| | - Niels Ørtenblad
- SDU Muscle Research Cluster (SMRC), Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark; Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, 83125 Östersund, Sweden
| |
Collapse
|
22
|
Chowdhury KK, Legare DJ, Lautt WW. Lifestyle impact on meal-induced insulin sensitization in health and prediabetes: A focus on diet, antioxidants, and exercise interventions. Can J Physiol Pharmacol 2013; 91:91-100. [DOI: 10.1139/cjpp-2012-0228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The augmented whole-body glucose uptake response to insulin during the postprandial state is described as meal-induced insulin sensitization (MIS). MIS occurs when the presence of food in the upper gastrointestinal tract activates 2 feeding signals (activation of hepatic parasympathetic nerves and elevation of hepatic glutathione level), and causes insulin to release hepatic insulin sensitizing substance (HISS), which stimulates glucose uptake in skeletal muscle, heart, and kidneys. HISS action results in nutrient storage, primarily as glycogen. Impairment of HISS release results in the absence of meal-induced insulin sensitization (AMIS), which causes postprandial hyperglycemia and hyperinsulinemia, and chronically leads to the progression to a cluster of metabolic, vascular, and cardiac dysfunctions, which we refer to as components of the AMIS syndrome. Manipulation of the MIS process in health and in disease, by pharmacological and nonpharmacological interventions, is outlined in this review. High fat or sugar supplemented diet reduces MIS; exercise elevates MIS; and antioxidants protect MIS against reductions associated with diet and age.
Collapse
Affiliation(s)
- Kawshik K. Chowdhury
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Manitoba, A210 – 753 McDermot Avenue, Winnipeg, MB R3E 0T6, Canada
| | - Dallas J. Legare
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Manitoba, A210 – 753 McDermot Avenue, Winnipeg, MB R3E 0T6, Canada
| | - W. Wayne Lautt
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Manitoba, A210 – 753 McDermot Avenue, Winnipeg, MB R3E 0T6, Canada
| |
Collapse
|
23
|
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]
|
24
|
Irimia JM, Rovira J, Nielsen JN, Guerrero M, Wojtaszewski JFP, Cussó R. Hexokinase 2, glycogen synthase and phosphorylase play a key role in muscle glycogen supercompensation. PLoS One 2012; 7:e42453. [PMID: 22860128 PMCID: PMC3409157 DOI: 10.1371/journal.pone.0042453] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 07/05/2012] [Indexed: 11/23/2022] Open
Abstract
Background Glycogen-depleting exercise can lead to supercompensation of muscle glycogen stores, but the biochemical mechanisms of this phenomenon are still not completely understood. Methods Using chronic low-frequency stimulation (CLFS) as an exercise model, the tibialis anterior muscle of rabbits was stimulated for either 1 or 24 hours, inducing a reduction in glycogen of 90% and 50% respectively. Glycogen recovery was subsequently monitored during 24 hours of rest. Results In muscles stimulated for 1 hour, glycogen recovered basal levels during the rest period. However, in those stimulated for 24 hours, glycogen was supercompensated and its levels remained 50% higher than basal levels after 6 hours of rest, although the newly synthesized glycogen had fewer branches. This increase in glycogen correlated with an increase in hexokinase-2 expression and activity, a reduction in the glycogen phosphorylase activity ratio and an increase in the glycogen synthase activity ratio, due to dephosphorylation of site 3a, even in the presence of elevated glycogen stores. During supercompensation there was also an increase in 5′-AMP-activated protein kinase phosphorylation, correlating with a stable reduction in ATP and total purine nucleotide levels. Conclusions Glycogen supercompensation requires a coordinated chain of events at two levels in the context of decreased cell energy balance: First, an increase in the glucose phosphorylation capacity of the muscle and secondly, control of the enzymes directly involved in the synthesis and degradation of the glycogen molecule. However, supercompensated glycogen has fewer branches.
Collapse
Affiliation(s)
- José M. Irimia
- Department of Physiological Sciences I, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | - Jordi Rovira
- Department of Physiological Sciences I, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | - Jakob N. Nielsen
- Molecular Physiology Group, Copenhagen Muscle Research Centre, Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mario Guerrero
- Department of Physiological Sciences I, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
| | - Jørgen F. P. Wojtaszewski
- Molecular Physiology Group, Copenhagen Muscle Research Centre, Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Roser Cussó
- Department of Physiological Sciences I, Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain
- * E-mail:
| |
Collapse
|
25
|
Beelen M, Kranenburg JV, Senden JM, Kuipers H, Loon LJCV. Impact of caffeine and protein on postexercise muscle glycogen synthesis. Med Sci Sports Exerc 2012; 44:692-700. [PMID: 21986807 DOI: 10.1249/mss.0b013e31823a40ef] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND Both protein and caffeine coingestion with CHO have been suggested to represent effective dietary strategies to further accelerate postexercise muscle glycogen synthesis in athletes. PURPOSE This study aimed to assess the effect of protein or caffeine coingestion on postexercise muscle glycogen synthesis rates when optimal amounts of CHO are ingested. METHODS Fourteen male cyclists were studied on three different test days. Each test day started with a glycogen-depleting exercise session. This was followed by a 6-h recovery period, during which subjects received 1.2 g·kg⁻¹·h⁻¹ CHO, the same amount of CHO with 0.3 g·kg⁻¹·h⁻¹ of a protein plus leucine mixture (CHO + PRO), or 1.7 mg·kg⁻¹·h⁻¹ caffeine (CHO + CAF). All drinks were enriched with [U-¹³C₆]-labeled glucose to assess potential differences in the appearance rate of ingested glucose from the gut. Muscle biopsies were collected immediately after cessation of exercise and after 6 h of postexercise recovery. RESULTS The plasma insulin response was higher in CHO + PRO compared with CHO and CHO + CAF (P < 0.01). Plasma glucose responses and glucose appearance rates did not differ between experiments. Muscle glycogen synthesis rates averaged 31 ± 4, 34 ± 4, and 31 ± 4 mmol·kg⁻¹ dry weight·h⁻¹ in CHO, CHO + PRO, and CHO + CAF, respectively (P = NS). In accordance, histochemical analyses did not show any differences between net changes in Type I and Type II muscle fiber glycogen content between experiments. CONCLUSIONS Coingestion of protein or caffeine does not further accelerate postexercise muscle glycogen synthesis when ample amounts of CHO (1.2 g·kg⁻¹·h⁻¹) are ingested.
Collapse
Affiliation(s)
- Milou Beelen
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | | | | | | | | |
Collapse
|
26
|
Milutinović A, Zorc-Pleskovič R. Glycogen accumulation in cardiomyocytes and cardiotoxic effects after 3NPA treatment. Bosn J Basic Med Sci 2012; 12:15-9. [PMID: 22364298 DOI: 10.17305/bjbms.2012.2525] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mitochondrial toxin 3-nitropropionic acid (3NPA) is a neurotoxin that inhibits the activity of succinate dehydrogenase, a key enzyme of oxidative energy production, and characteristically provokes neurodegeneration in the striatum, resembling Huntington's disease. 3NPA also affects the activity of glycogen-sinthase-kinase-3b (GSK-3b), an enzyme implicated in glycogen synthesis and in signal transduction. The aim of this study was to evaluate cardiac glycogen content and histopathological changes in the hearts of rats after subchronic treatment with 3NPA.Female adult Wistar rats were treated daily with 30mg/kg of 3NPA subcutaneously 8 days. The control group was treated with normal saline for 8 days. For the comparison of measured parameters between groups we used the Student's t-test (p<0.05). The stereological evaluation of glycogen content in histological sections of the heart was processed with periodic acid-Schiff (PAS). Histochemical procedure showed a significant accumulation of glycogen granules in the 3NPA group (0.028mm(3)/mm(3)±0.022), whereas the hearts of control animals were nearly devoid of glycogen granules (0.002mm(3)/mm(3)±0.001). Haematoxylin-eosin histological staining showed diffuse swelling of cardiomyocytes (3NPA=15.989μm ±1.649; saline=13.456μm ± 0.786), loss of cell cross-striations, lower myofibril volume fraction (3NPA=0.3922mm(3)/mm3 ± 0.0230, saline=0.4550mm(3)/mm3 ± 0.0083), and mononuclear infiltration in the interstitial tissue, mostly along the blood vessels. Sirius red staining showed fibrosis of the heart (3NPA=0.0531mm93)/mm(3)±0.0090, saline=0.0135mm(3)/mm3 ± 0.0051). TUNEL staining showed TUNEL-positive cells in the 3NPA group (2.04cells/mm2 ± 0.92) and almost no TUNEL-positive cells in the saline group (0.27cells/mm2 ± 0.14). This experiment shows that 3NPA-induced histopathological changes in the heart are accompanied by a significant accumulation of glycogen granules in cardiomyocytes.
Collapse
Affiliation(s)
- Aleksandra Milutinović
- University of Ljubljana, Medical Faculty, Institute of Histology and Embryology, Ljubljana, Slovenia.
| | | |
Collapse
|
27
|
Tiberia E, Turnbull J, Wang T, Ruggieri A, Zhao XC, Pencea N, Israelian J, Wang Y, Ackerley CA, Wang P, Liu Y, Minassian BA. Increased laforin and laforin binding to glycogen underlie Lafora body formation in malin-deficient Lafora disease. J Biol Chem 2012; 287:25650-9. [PMID: 22669944 DOI: 10.1074/jbc.m111.331611] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The solubility of glycogen, essential to its metabolism, is a property of its shape, a sphere generated through extensive branching during synthesis. Lafora disease (LD) is a severe teenage-onset neurodegenerative epilepsy and results from multiorgan accumulations, termed Lafora bodies (LB), of abnormally structured aggregation-prone and digestion-resistant glycogen. LD is caused by loss-of-function mutations in the EPM2A or EPM2B gene, encoding the interacting laforin phosphatase and malin E3 ubiquitin ligase enzymes, respectively. The substrate and function of malin are unknown; an early counterintuitive observation in cell culture experiments that it targets laforin to proteasomal degradation was not pursued until now. The substrate and function of laforin have recently been elucidated. Laforin dephosphorylates glycogen during synthesis, without which phosphate ions interfere with and distort glycogen construction, leading to LB. We hypothesized that laforin in excess or not removed following its action on glycogen also interferes with glycogen formation. We show in malin-deficient mice that the absence of malin results in massively increased laforin preceding the appearance of LB and that laforin gradually accumulates in glycogen, which corresponds to progressive LB generation. We show that increasing the amounts of laforin in cell culture causes LB formation and that this occurs only with glycogen binding-competent laforin. In summary, malin deficiency causes increased laforin, increased laforin binding to glycogen, and LB formation. Furthermore, increased levels of laforin, when it can bind glycogen, causes LB. We conclude that malin functions to regulate laforin and that malin deficiency at least in part causes LB and LD through increased laforin binding to glycogen.
Collapse
Affiliation(s)
- Erica Tiberia
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Biensø RS, Ringholm S, Kiilerich K, Aachmann-Andersen NJ, Krogh-Madsen R, Guerra B, Plomgaard P, van Hall G, Treebak JT, Saltin B, Lundby C, Calbet JAL, Pilegaard H, Wojtaszewski JFP. GLUT4 and glycogen synthase are key players in bed rest-induced insulin resistance. Diabetes 2012; 61:1090-9. [PMID: 22403297 PMCID: PMC3331744 DOI: 10.2337/db11-0884] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To elucidate the molecular mechanisms behind physical inactivity-induced insulin resistance in skeletal muscle, 12 young, healthy male subjects completed 7 days of bed rest with vastus lateralis muscle biopsies obtained before and after. In six of the subjects, muscle biopsies were taken from both legs before and after a 3-h hyperinsulinemic euglycemic clamp performed 3 h after a 45-min, one-legged exercise. Blood samples were obtained from one femoral artery and both femoral veins before and during the clamp. Glucose infusion rate and leg glucose extraction during the clamp were lower after than before bed rest. This bed rest-induced insulin resistance occurred together with reduced muscle GLUT4, hexokinase II, protein kinase B/Akt1, and Akt2 protein level, and a tendency for reduced 3-hydroxyacyl-CoA dehydrogenase activity. The ability of insulin to phosphorylate Akt and activate glycogen synthase (GS) was reduced with normal GS site 3 but abnormal GS site 2+2a phosphorylation after bed rest. Exercise enhanced insulin-stimulated leg glucose extraction both before and after bed rest, which was accompanied by higher GS activity in the prior-exercised leg than the rested leg. The present findings demonstrate that physical inactivity-induced insulin resistance in muscle is associated with lower content/activity of key proteins in glucose transport/phosphorylation and storage.
Collapse
Affiliation(s)
- Rasmus S Biensø
- Copenhagen Muscle Research Centre, University of Copenhagen, Copenhagen, Denmark.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Kuznetsova LA, Chistyakova OV. Experimental models of diabetes mellitus types 1 and 2 in rats: Regulation of activity of glycogen synthase by peptides of the insulin superfamily and by epidermal growth factor in skeletal muscles. J EVOL BIOCHEM PHYS+ 2012. [DOI: 10.1134/s0022093012010045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
30
|
Lin FC, Bolling A, Stuenæs JT, Cumming KT, Ingvaldsen A, Lai YC, Ivy JL, Jensen J. Effect of insulin and contraction on glycogen synthase phosphorylation and kinetic properties in epitrochlearis muscles from lean and obese Zucker rats. Am J Physiol Cell Physiol 2012; 302:C1539-47. [PMID: 22403789 DOI: 10.1152/ajpcell.00430.2011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In the present study, the effects of insulin and contraction on glycogen synthase (GS) kinetic properties and phosphorylation were investigated in epitrochlearis muscles from lean and obese Zucker rats. Total GS activity and protein expression were ~15% lower in epitrochlearis from obese rats compared with lean rats. Insulin-stimulated GS fractional activity and affinity for UDP-glucose were lower (higher K(m)) in muscles from obese rats. GS Ser(641) and Ser(645,649,653,657) phosphorylation was higher in insulin-stimulated muscles from obese rats, which agreed with lower GS activation. Contraction-mediated GS dephosphorylation of Ser(641), Ser(641+645), Ser(645,649,653,657), and Ser(7+10) was normal in muscles from obese Zucker rats, and GS fractional activity increased to similar levels in epitrochlearis muscles from lean and obese rats. GS affinity for UDP glucose was ~0.8, ~0.4, and ~0.1 mM with assay buffers containing 0, 0.17, and 12 mM glucose 6-phosphate, respectively. Contraction increased affinity for UDP-glucose (reduced K(m)) at a physiological concentration of glucose 6-phosphate (0.17 mM) to ~0.2 mM in muscles from both lean and obese rats. Interestingly, in the absence of glucose 6-phosphate in the assay buffer, contraction (and insulin) did not influence GS affinity for UDP-glucose, indicating that affinity is regulated by sensitivity for glucose 6-phosphate. In conclusion, contraction-mediated activation and dephosphorylation of GS were normal in muscles from obese Zucker rats, whereas insulin-mediated GS activation and dephosphorylation were impaired.
Collapse
Affiliation(s)
- Fang Chin Lin
- Department of Physical Performance, Norwegian School of Sport Sciences, P. O. Box 4014 Ullevål Stadion, N-0806 Oslo, Norway
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Obel LF, Müller MS, Walls AB, Sickmann HM, Bak LK, Waagepetersen HS, Schousboe A. Brain glycogen-new perspectives on its metabolic function and regulation at the subcellular level. FRONTIERS IN NEUROENERGETICS 2012; 4:3. [PMID: 22403540 PMCID: PMC3291878 DOI: 10.3389/fnene.2012.00003] [Citation(s) in RCA: 141] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 02/13/2012] [Indexed: 11/14/2022]
Abstract
Glycogen is a complex glucose polymer found in a variety of tissues, including brain, where it is localized primarily in astrocytes. The small quantity found in brain compared to e.g., liver has led to the understanding that brain glycogen is merely used during hypoglycemia or ischemia. In this review evidence is brought forward highlighting what has been an emerging understanding in brain energy metabolism: that glycogen is more than just a convenient way to store energy for use in emergencies—it is a highly dynamic molecule with versatile implications in brain function, i.e., synaptic activity and memory formation. In line with the great spatiotemporal complexity of the brain and thereof derived focus on the basis for ensuring the availability of the right amount of energy at the right time and place, we here encourage a closer look into the molecular and subcellular mechanisms underlying glycogen metabolism. Based on (1) the compartmentation of the interconnected second messenger pathways controlling glycogen metabolism (calcium and cAMP), (2) alterations in the subcellular location of glycogen-associated enzymes and proteins induced by the metabolic status and (3) a sequential component in the intermolecular mechanisms of glycogen metabolism, we suggest that glycogen metabolism in astrocytes is compartmentalized at the subcellular level. As a consequence, the meaning and importance of conventional terms used to describe glycogen metabolism (e.g., turnover) is challenged. Overall, this review represents an overview of contemporary knowledge about brain glycogen and its metabolism and function. However, it also has a sharp focus on what we do not know, which is perhaps even more important for the future quest of uncovering the roles of glycogen in brain physiology and pathology.
Collapse
Affiliation(s)
- Linea F Obel
- Faculty of Health and Medical Sciences, Department of Drug Design and Pharmacology, University of Copenhagen Copenhagen, Denmark
| | | | | | | | | | | | | |
Collapse
|
32
|
Nielsen J, Krustrup P, Nybo L, Gunnarsson TP, Madsen K, Schrøder HD, Bangsbo J, Ortenblad N. Skeletal muscle glycogen content and particle size of distinct subcellular localizations in the recovery period after a high-level soccer match. Eur J Appl Physiol 2012; 112:3559-67. [PMID: 22323299 DOI: 10.1007/s00421-012-2341-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2011] [Accepted: 01/27/2012] [Indexed: 10/14/2022]
Abstract
Whole muscle glycogen levels remain low for a prolonged period following a soccer match. The present study was conducted to investigate how this relates to glycogen content and particle size in distinct subcellular localizations. Seven high-level male soccer players had a vastus lateralis muscle biopsy collected immediately after and 24, 48, 72 and 120 h after a competitive soccer match. Transmission electron microscopy was used to estimate the subcellular distribution of glycogen and individual particle size. During the first day of recovery, glycogen content increased by ~60% in all subcellular localizations, but during the subsequent second day of recovery glycogen content located within the myofibrils (Intramyofibrillar glycogen, a minor deposition constituting 10-15% of total glycogen) did not increase further compared with an increase in subsarcolemmal glycogen (-7 vs. +25%, respectively, P = 0.047). Conversely, from the second to the fifth day of recovery, glycogen content increased (53%) within the myofibrils compared to no change in subsarcolemmal or intermyofibrillar glycogen (P < 0.005). Independent of location, increment in particle size preceded increment in number of particles. Intriguingly, average particle size decreased; however, in the period from 3 to 5 days after the match. These findings suggest that glycogen storage in skeletal muscle is influenced by subcellular localization-specific mechanisms, which account for an increase in number of glycogen particles located within the myofibrils in the period from 2 to 5 days after the soccer match.
Collapse
Affiliation(s)
- Joachim Nielsen
- Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, 5230 Odense M, Denmark.
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Jensen TE, Richter EA. Regulation of glucose and glycogen metabolism during and after exercise. J Physiol 2011; 590:1069-76. [PMID: 22199166 DOI: 10.1113/jphysiol.2011.224972] [Citation(s) in RCA: 159] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Utilization of carbohydrate in the form of intramuscular glycogen stores and glucose delivered from plasma becomes an increasingly important energy substrate to the working muscle with increasing exercise intensity. This review gives an update on the molecular signals by which glucose transport is increased in the contracting muscle followed by a discussion of glycogen mobilization and synthesis by the action of glycogen phosphorylase and glycogen synthase, respectively. Finally, this review deals with the signalling relaying the well-described increased sensitivity of glucose transport to insulin in the post-exercise period which can result in an overshoot of intramuscular glycogen resynthesis post exercise (glycogen supercompensation).
Collapse
Affiliation(s)
- Thomas E Jensen
- Molecular Physiology Group, Department of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark.
| | | |
Collapse
|
34
|
Montori-Grau M, Guitart M, García-Martínez C, Orozco A, Gómez-Foix AM. Differential pattern of glycogen accumulation after protein phosphatase 1 glycogen-targeting subunit PPP1R6 overexpression, compared to PPP1R3C and PPP1R3A, in skeletal muscle cells. BMC BIOCHEMISTRY 2011; 12:57. [PMID: 22054094 PMCID: PMC3240831 DOI: 10.1186/1471-2091-12-57] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 11/04/2011] [Indexed: 01/17/2023]
Abstract
BACKGROUND PPP1R6 is a protein phosphatase 1 glycogen-targeting subunit (PP1-GTS) abundant in skeletal muscle with an undefined metabolic control role. Here PPP1R6 effects on myotube glycogen metabolism, particle size and subcellular distribution are examined and compared with PPP1R3C/PTG and PPP1R3A/G(M). RESULTS PPP1R6 overexpression activates glycogen synthase (GS), reduces its phosphorylation at Ser-641/0 and increases the extracted and cytochemically-stained glycogen content, less than PTG but more than G(M). PPP1R6 does not change glycogen phosphorylase activity. All tested PP1-GTS-cells have more glycogen particles than controls as found by electron microscopy of myotube sections. Glycogen particle size is distributed for all cell-types in a continuous range, but PPP1R6 forms smaller particles (mean diameter 14.4 nm) than PTG (36.9 nm) and G(M) (28.3 nm) or those in control cells (29.2 nm). Both PPP1R6- and G(M)-derived glycogen particles are in cytosol associated with cellular structures; PTG-derived glycogen is found in membrane- and organelle-devoid cytosolic glycogen-rich areas; and glycogen particles are dispersed in the cytosol in control cells. A tagged PPP1R6 protein at the C-terminus with EGFP shows a diffuse cytosol pattern in glucose-replete and -depleted cells and a punctuate pattern surrounding the nucleus in glucose-depleted cells, which colocates with RFP tagged with the Golgi targeting domain of β-1,4-galactosyltransferase, according to a computational prediction for PPP1R6 Golgi location. CONCLUSIONS PPP1R6 exerts a powerful glycogenic effect in cultured muscle cells, more than G(M) and less than PTG. PPP1R6 protein translocates from a Golgi to cytosolic location in response to glucose. The molecular size and subcellular location of myotube glycogen particles is determined by the PPP1R6, PTG and G(M) scaffolding.
Collapse
Affiliation(s)
- Marta Montori-Grau
- CIBER de Diabetes y Enfermedades Metabólicas Asociadas, Barcelona, Spain.
| | | | | | | | | |
Collapse
|
35
|
Hara D, Morrison PJ, Ding Z, Ivy JL. Effect of carbohydrate-protein supplementation postexercise on rat muscle glycogen synthesis and phosphorylation of proteins controlling glucose storage. Metabolism 2011; 60:1406-15. [PMID: 21489581 DOI: 10.1016/j.metabol.2011.02.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 02/08/2011] [Accepted: 02/10/2011] [Indexed: 11/16/2022]
Abstract
To examine whether addition of protein to a carbohydrate supplement enhances muscle glycogen synthesis, we compared the muscle glycogen concentrations of rats that had been depleted of their muscle glycogen stores with a 3-hour swim and immediately supplemented with a placebo (Con), carbohydrate (CHO), or carbohydrate plus protein supplement (C+P). Rats were given either 0.9 g carbohydrate per kilogram body mass for the CHO group or 0.9 g carbohydrate + 0.3 g protein per kilogram body mass for the C+P groups. Muscle samples of the red and white quadriceps were excised immediately, 30 minutes, or 90 minutes postexercise. Glycogen concentration of the C+P group was greater than that of the CHO group at 90 minutes postexercise in both red (C+P, 28.3 ± 2.6 µmol/g vs CHO, 22.4 ± 2.0 µmol/g; P < .05) and white (C+P, 24.9 ± 2.4 µmol/g vs CHO, 17.64 ± 1.5 µmol/g; P < .01) quadriceps. Protein kinase B phosphorylation was greater in the C+P-30 group (the number following treatment group abbreviation refers to time [in minutes] of euthanasia following exercise) than the sedentary control and exercised control groups in red quadriceps at 30 minutes and in white quadriceps at 90 minutes postexercise. This difference was not observed in the CHO group. Phosphorylation of glycogen synthase was significantly reduced 30 minutes postexercise and returned to baseline levels by 90 minutes postexercise in both CHO- and C+P-supplemented groups, with no difference between supplements. These results demonstrated that the addition of protein to a carbohydrate supplement will enhance the rate of muscle glycogen restoration postexercise and may involve facilitation of the glucose transport process.
Collapse
Affiliation(s)
- Daisuke Hara
- Exercise Physiology and Metabolism Laboratory, Department of Kinesiology and Health Education, University of Texas, Austin, TX 78712, USA
| | | | | | | |
Collapse
|
36
|
Alonso-Chamorro M, Nieto-Vazquez I, Montori-Grau M, Gomez-Foix AM, Fernandez-Veledo S, Lorenzo M. New emerging role of protein-tyrosine phosphatase 1B in the regulation of glycogen metabolism in basal and TNF-α-induced insulin-resistant conditions in an immortalised muscle cell line isolated from mice. Diabetologia 2011; 54:1157-68. [PMID: 21311858 DOI: 10.1007/s00125-011-2057-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 12/22/2010] [Indexed: 10/18/2022]
Abstract
AIMS/HYPOTHESIS Protein-tyrosine phosphatase 1B (PTP1B) negatively regulates insulin action, promoting attenuation of the insulin signalling pathway. The production of this phosphatase is enhanced in insulin-resistant states, such as obesity and type 2 diabetes, where high levels of proinflammatory cytokines (TNF-α, IL-6) are found. In these metabolic conditions, insulin action on glycogen metabolism in skeletal muscle is greatly impaired. We addressed the role of PTP1B on glycogen metabolism in basal and insulin-resistant conditions promoted by TNF-α. METHODS We studied the effect of TNF-α in the presence and absence of insulin on glycogen content and synthesis, glycogen synthase (GS) and glycogen phosphorylase (GP) activities and on glycogen synthesis and degradation signalling pathways. For this purpose we used immortalised cell lines isolated from skeletal muscle from mice lacking PTP1B. RESULTS Absence of PTP1B caused activation of GS and GP with a net glycogenolytic effect, reflected in lower amounts of glycogen and activation of the glycogenolytic signalling pathway, with higher rates of phosphorylation of cyclic adenosine monophosphate-dependent kinase (PKA), phosphorylase kinase (PhK) and GP phosphorylation. Nevertheless, insulin action was strongly enhanced in Ptp1b (also known as Ptpn1)(-/-) cells in terms of glycogen content, synthesis, GS activation rates and GS Ser641 dephosphorylation. Treatment with TNF-α augmented the activity ratios of both GS and GP, and impaired insulin stimulation of glycogen synthesis in wild-type myocytes, whereas Ptp1b (-/-) myocytes restored this inhibitory effect. We report a glycogenolytic effect of TNF-α, as demonstrated by greater activation of the degradation signalling cascade PKA/PhK/GP. In our model, this effect is mediated by the activation of PKA. CONCLUSIONS/INTERPRETATION We provide new data about the role of PTP1B in glycogen metabolism and confirm the beneficial effect that absence of the phosphatase confers against an insulin-resistant condition.
Collapse
Affiliation(s)
- M Alonso-Chamorro
- Department of Biochemistry and Molecular Biology II, Faculty of Pharmacy, Universidad Complutense de Madrid, 28040 Madrid, Spain.
| | | | | | | | | | | |
Collapse
|
37
|
Berman Y, North KN. A gene for speed: the emerging role of alpha-actinin-3 in muscle metabolism. Physiology (Bethesda) 2010; 25:250-9. [PMID: 20699471 DOI: 10.1152/physiol.00008.2010] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A common polymorphism (R577X) in the ACTN3 gene results in complete deficiency of alpha-actinin-3 protein in approximately 16% of humans worldwide. The presence of alpha-actinin-3 protein is associated with improved sprint/power performance in athletes and the general population. Despite this, there is evidence that the null genotype XX has been acted on by recent positive selection, likely due to its emerging role in the regulation of muscle metabolism. alpha-Actinin-3 deficiency reduces the activity of glycogen phosphorylase and results in a fundamental shift toward more oxidative pathways of energy utilization.
Collapse
Affiliation(s)
- Yemima Berman
- Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, Westmead, Australia
| | | |
Collapse
|
38
|
Nielsen J, Suetta C, Hvid LG, Schrøder HD, Aagaard P, Ortenblad N. Subcellular localization-dependent decrements in skeletal muscle glycogen and mitochondria content following short-term disuse in young and old men. Am J Physiol Endocrinol Metab 2010; 299:E1053-60. [PMID: 20858747 DOI: 10.1152/ajpendo.00324.2010] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Previous studies have shown that skeletal muscle glycogen and mitochondria are distributed in distinct subcellular localizations, but the role and regulation of these subcellular localizations are unclear. In the present study, we used transmission electron microscopy to investigate the effect of disuse and aging on human skeletal muscle glycogen and mitochondria content in subsarcolemmal (SS), intermyofibrillar (IMF), and intramyofibrillar (intra) localizations. Five young (∼23 yr) and five old (∼66 yr) recreationally active men had their quadriceps muscle immobilized for 2 wk by whole leg casting. Biopsies were obtained from m. vastus lateralis before and after the immobilization period. Immobilization induced a decrement of intra glycogen content by 54% (P < 0.001) in both age groups and in two ultrastructurally distinct fiber types, whereas the content of IMF and SS glycogen remained unchanged. A localization-dependent decrease (P = 0.03) in mitochondria content following immobilization was found in both age groups, where SS mitochondria decreased by 33% (P = 0.02), superficial IMF mitochondria decreased by 20% (P = 0.05), and central IMF mitochondria remained unchanged. In conclusion, our findings demonstrate a localization-dependent adaptation to immobilization in glycogen and mitochondria content of skeletal muscles of both young and old individuals. Specifically, this suggests that short-term disuse preferentially affects glycogen particles located inside the myofibrils and that mitochondria volume plasticity can be dependent on the distance to the fiber border.
Collapse
|
39
|
Abstract
Glycogen metabolism serves as a critical regulator of energy storage and maintenance of blood glucose levels in a physiological range. In this issue of Cell Metabolism, Bouskila et al. (2010) unexpectedly find that skeletal muscle glycogen accumulation is principally controlled by the allosteric activation of glycogen synthase, opening new avenues for investigation.
Collapse
Affiliation(s)
- Matthew J Brady
- Department of Medicine, Kovler Diabetes Center, University of Chicago, IL 60637, USA.
| |
Collapse
|
40
|
Graham TE, Yuan Z, Hill AK, Wilson RJ. The regulation of muscle glycogen: the granule and its proteins. Acta Physiol (Oxf) 2010; 199:489-98. [PMID: 20353490 DOI: 10.1111/j.1748-1716.2010.02131.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Despite decades of studying muscle glycogen in many metabolic situations, surprisingly little is known regarding its regulation. Glycogen is a dynamic and vital metabolic fuel that has very limited energetic capacity. Thus its regulation is highly complex and multifaceted. The stores in muscle are not homogeneous and there appear to be various metabolic pools. Each granule is capable of independent regulation and fundamental aspects of the regulation appear to be associated with a complex set of proteins (some are enzymes and others serve scaffolding roles) that associate both with the granule and with each other in a dynamic fashion. The regulation includes altered phosphorylation status and often translocation as well. The understanding of the roles and the regulation of glycogenin, protein phosphatase 1, glycogen targeting proteins, laforin and malin are in their infancy. These various processes appear to be the mechanisms that give the glycogen granule precise, yet dynamic regulation.
Collapse
Affiliation(s)
- T E Graham
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada.
| | | | | | | |
Collapse
|
41
|
Lai YC, Stuenaes JT, Kuo CH, Jensen J. Insulin-stimulated glycogen synthesis and glycogen synthase activation after electrical stimulation of epitrochlearis muscles with different initial glycogen contents. Arch Physiol Biochem 2010; 116:116-27. [PMID: 20597590 DOI: 10.3109/13813455.2010.494670] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Glycogen synthesis increases after muscle contraction and during insulin stimulation, and insulin-stimulated glycogen synthesis is enhanced after contraction. We hypothesized that the initial glycogen content influences the magnitude of additive effect of contraction on insulin-stimulated glycogen synthesis. Contraction and insulin had full additive effect on rate of glycogen synthesis measured after contraction in muscles with normal and high glycogen content. In muscles with low glycogen, contraction increased insulin-stimulated glycogen synthesis nearly as much as in muscles with normal glycogen, but not to the sum of the two stimuli studied separately; still glycogen synthesis was generally highest in muscles with low glycogen. Glycogen synthase fractional activity inversely correlated with glycogen content and contraction increased glycogen synthase fractional activity. Contraction and insulin additively increased glycogen synthase fractional activity at all glycogen contents. In conclusion, after contraction insulin-stimulated glycogen synthesis was increased by rather similar magnitude at all glycogen contents in concert with increased glycogen synthase activation.
Collapse
Affiliation(s)
- Yu-Chiang Lai
- Department of Physical Performance, Norwegian School of Sport Sciences, PO Box 4014 Ullevål Stadion, N-0806 Oslo, Norway
| | | | | | | |
Collapse
|
42
|
Waller AP, Lindinger MI. Nutritional aspects of post exercise skeletal muscle glycogen synthesis in horses: a comparative review. Equine Vet J 2010; 42:274-81. [PMID: 20486986 DOI: 10.2746/042516409x479603] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Carbohydrate (CHO) stored in the form of skeletal muscle glycogen is the main energy source for glycolytic and oxidative ATP production during vigorous exercise in mammals. In man, horse and dog both short-term high intensity and prolonged submaximal exercise deplete muscle glycogen. In horses, however, muscle glycogen synthesis is 2-3-fold slower than in man and rat, even when a diet high in soluble CHO is fed. There appear to be significant differences in CHO and glycogen metabolism between horses and other mammals, and it is becoming increasingly clear that many conclusions drawn from human exercise physiology do not apply to horses. This review aims to provide a comprehensive, comparative summary of the research on muscle glycogen synthesis in horse, man and rodent. Species differences in CHO uptake and utilisation are examined and the issues with feeding high soluble CHO diets to horses are discussed. Alternative feeding strategies, including protein and long and short chain fatty acid supplementation and the importance of rehydration, are explored.
Collapse
Affiliation(s)
- A P Waller
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
| | | |
Collapse
|
43
|
Stephens FB, Norton L, Jewell K, Chokkalingam K, Parr T, Tsintzas K. Basal and insulin-stimulated pyruvate dehydrogenase complex activation, glycogen synthesis and metabolic gene expression in human skeletal muscle the day after a single bout of exercise. Exp Physiol 2010; 95:808-18. [DOI: 10.1113/expphysiol.2009.051367] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
44
|
Lai YC, Zarrinpashneh E, Jensen J. Additive effect of contraction and insulin on glucose uptake and glycogen synthase in muscle with different glycogen contents. J Appl Physiol (1985) 2010; 108:1106-15. [PMID: 20185632 DOI: 10.1152/japplphysiol.00401.2009] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Insulin and contraction regulate glucose uptake and glycogen synthase (GS) via distinct mechanisms in skeletal muscles, and an additive effect has been reported. Glycogen content is known to influence both contraction- and insulin-stimulated glucose uptake and GS activity. Our study reports that contraction and insulin additively stimulate glucose uptake in rat epitrochlearis muscles with normal (NG) and high (HG) glycogen contents, but the additive effect was only partial. In muscles with low glycogen (LG) content no additive effect was seen, but glucose uptake was higher in LG than in NG and HG during contraction, insulin stimulation, and when the two stimuli were combined. In LG, contraction-stimulated AMP-activated protein kinase (AMPK) activity and insulin-stimulated PKB phosphorylation were higher than in NG and HG, but phosphorylation of Akt substrate of 160 kDa was not elevated correspondingly. GLUT4 content was 50% increased in LG (rats fasted 24 h), which may explain the increased glucose uptake. Contraction and insulin also additively increased GS fractional activity in NG and HG but not in LG. GS fractional activity correlated most strongly with GS Ser641 phosphorylation (R -0.94, P<0.001). GS fractional activity also correlated with GS Ser7,10 phosphorylation, but insulin did not reduce GS Ser7,10 phosphorylation. In conclusion, an additive effect of contraction and insulin on glucose uptake and GS activity occurs in muscles with normal and high glycogen content but not in muscles with low glycogen content. Furthermore, contraction, insulin, and glycogen content all regulate GS Ser641 phosphorylation and GS fractional activity in concert.
Collapse
Affiliation(s)
- Yu-Chiang Lai
- Department of Physiology, National Institute of Occupational Health, Oslo, Norway
| | | | | |
Collapse
|
45
|
Cochran AJR, Little JP, Tarnopolsky MA, Gibala MJ. Carbohydrate feeding during recovery alters the skeletal muscle metabolic response to repeated sessions of high-intensity interval exercise in humans. J Appl Physiol (1985) 2010; 108:628-36. [PMID: 20056852 DOI: 10.1152/japplphysiol.00659.2009] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Exercise training under conditions of reduced carbohydrate (CHO) availability has been reported to augment gains in skeletal muscle oxidative capacity; however, the underlying mechanisms are unclear. We examined the effect of manipulating CHO intake on the acute metabolic response to high-intensity interval exercise, including signaling cascades linked to mitochondrial biogenesis. Ten men performed two trials in random order separated by >or=1 wk. Each trial consisted of a morning (AM) and afternoon (PM) training session (5 x 4 min cycling at approximately 90-95% of heart rate reserve) separated by 3 h of recovery during which subjects ingested a high-CHO drink (HI-HI) or nonenergetic placebo (HI-LO) before PM exercise. Biopsies (vastus lateralis) revealed that muscle phosphocreatine and ATP content were similar after AM exercise but decreased to a greater extent during PM exercise in HI-LO vs. HI-HI. Phosphorylation of p38 mitogen-activated protein kinase (MAPK) and AMP-activated protein kinase (AMPK) increased approximately 4-fold and 2-fold, respectively, during AM exercise with no difference between conditions. After PM exercise, p38 MAPK phosphorylation was higher in HI-LO vs. HI-HI, whereas AMPK was not different between conditions. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1 alpha) gene expression increased approximately 8-fold during recovery from AM exercise and remained elevated during PM exercise with no differences between conditions. Cytochrome oxidase subunit 4 (COXIV) mRNA was also elevated 3 h after AM exercise, with no difference between conditions. These data provide evidence that p38 MAPK is a nutrient-sensitive signaling molecule that could be involved in the altered skeletal muscle adaptive response reported after exercise training under conditions of restricted CHO intake, but further research is required to confirm this hypothesis.
Collapse
Affiliation(s)
- Andrew J R Cochran
- Exercise Metabolism Research Group, Department of Kinesiology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | | | | | | |
Collapse
|
46
|
Lai YC, Lin FC, Jensen J. Glycogen content regulates insulin- but not contraction-mediated glycogen synthase activation in the rat slow-twitch soleus muscles. Acta Physiol (Oxf) 2009; 197:139-50. [PMID: 19432592 DOI: 10.1111/j.1748-1716.2009.01998.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM The aim of this study was to investigate the effect of glycogen content on glycogen synthase (GS) activation and phosphorylation in the slow-twitch soleus muscles after contraction, during insulin stimulation and when these two stimuli were combined. METHODS Glycogen content was manipulated in vivo with 24 h fasting and fasting followed by 24 h refeeding. Soleus strips were electrically stimulated for 30 min in vitro, and GS activation and phosphorylation were investigated after an additional 30 min incubation with or without insulin. RESULTS Fasting reduced glycogen content in soleus muscle by 40% and refeeding enhanced by 40%, compared to rats with free access to chow. Insulin-stimulated GS fractional activity was inversely correlated with glycogen content (R = -0.95, P < 0.001, n = 24) and rate of glycogen synthesis was also inversely correlated with glycogen content (R = -0.70, P < 0.001, n = 36). After contraction, GS fractional activity was increased to similar levels in muscles with low, normal and high glycogen content; rate of glycogen synthesis after contraction was also similar. After contraction, insulin additively increased GS activation at all glycogen contents. Group means of GS fractional activity was inversely correlated with GS Ser(641) (R = -0.93, P < 0.001) and Ser(645,649,653,657) (R = -0.85, P < 0.001) phosphorylation, but not with Ser(7) phosphorylation. CONCLUSION Glycogen content regulates insulin- but not contraction-stimulated GS activation and glycogen synthesis in soleus muscles. Furthermore, phosphorylation of GS Ser(641) and Ser(645,649,653,657) seems to regulate GS activity in soleus.
Collapse
Affiliation(s)
- Y-C Lai
- Department of Physiology, National Institute of Occupational Health, Oslo, Norway
| | | | | |
Collapse
|
47
|
Graham TE. Glycogen: an overview of possible regulatory roles of the proteins associated with the granule. Appl Physiol Nutr Metab 2009; 34:488-92. [PMID: 19448719 DOI: 10.1139/h09-048] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
While scientists have routinely measured muscle glycogen in many metabolic situations for over 4 decades, there is surprisingly little known regarding its regulation. In the past decade, considerable evidence has illustrated that the carbohydrate stores in muscle are not homogeneous, and it is very likely that metabolic pools exist or that each granule has independent regulation. The fundamental aspects appear to be associated with a complex set of proteins that associate with both the granule and each other in a dynamic fashion. Some of the proteins are enzymes and others play scaffolding roles. A number of the proteins can translocate, depending on the metabolic stimulus. These various processes appear to be the mechanisms that give the glycogen granule precise yet dynamic regulation. This may also allow the stores to serve as an important metabolic regulator of other metabolic events.
Collapse
Affiliation(s)
- Terry E Graham
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
| |
Collapse
|
48
|
Prats C, Helge JW, Nordby P, Qvortrup K, Ploug T, Dela F, Wojtaszewski JFP. Dual regulation of muscle glycogen synthase during exercise by activation and compartmentalization. J Biol Chem 2009; 284:15692-700. [PMID: 19339242 DOI: 10.1074/jbc.m900845200] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glycogen synthase (GS) is considered the rate-limiting enzyme in glycogenesis but still today there is a lack of understanding on its regulation. We have previously shown phosphorylation-dependent GS intracellular redistribution at the start of glycogen re-synthesis in rabbit skeletal muscle (Prats, C., Cadefau, J. A., Cussó, R., Qvortrup, K., Nielsen, J. N., Wojtaszewki, J. F., Wojtaszewki, J. F., Hardie, D. G., Stewart, G., Hansen, B. F., and Ploug, T. (2005) J. Biol. Chem. 280, 23165-23172). In the present study we investigate the regulation of human muscle GS activity by glycogen, exercise, and insulin. Using immunocytochemistry we investigate the existence and relevance of GS intracellular compartmentalization during exercise and during glycogen re-synthesis. The results show that GS intrinsic activity is strongly dependent on glycogen levels and that such regulation involves associated dephosphorylation at sites 2+2a, 3a, and 3a + 3b. Furthermore, we report the existence of several glycogen metabolism regulatory mechanisms based on GS intracellular compartmentalization. After exhausting exercise, epinephrine-induced protein kinase A activation leads to GS site 1b phosphorylation targeting the enzyme to intramyofibrillar glycogen particles, which are preferentially used during muscle contraction. On the other hand, when phosphorylated at sites 2+2a, GS is preferentially associated with subsarcolemmal and intermyofibrillar glycogen particles. Finally, we verify the existence in human vastus lateralis muscle of the previously reported mechanism of glycogen metabolism regulation in rabbit tibialis anterior muscle. After overnight low muscle glycogen level and/or in response to exhausting exercise-induced glycogenolysis, GS is associated with spherical structures at the I-band of sarcomeres.
Collapse
Affiliation(s)
- Clara Prats
- Copenhagen Muscle Research Center, Center for Healthy Ageing, Department of Biomedical Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark.
| | | | | | | | | | | | | |
Collapse
|
49
|
Jensen J, Lai YC. Regulation of muscle glycogen synthase phosphorylation and kinetic properties by insulin, exercise, adrenaline and role in insulin resistance. Arch Physiol Biochem 2009; 115:13-21. [PMID: 19267278 DOI: 10.1080/13813450902778171] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
In mammals, excess carbohydrate is stored as glycogen and glycogen synthase is the enzyme that incorporates glucose units into the glycogen particle. Glycogen synthase activity is regulated by phosphorylation and allosterically activated by glucose 6-phosphate. Phosphorylation of nine serines by different kinases regulates glycogen synthase affinity for glucose 6-phosphate and its substrate UDP-glucose. Glucose 6-phosphate increases both enzyme activity and substrate affinity. Insulin and exercise increase glycogen synthase affinity for glucose 6-phosphate and activity whereas high glycogen content and adrenaline decrease affinity for glucose 6-phosphate and activity. However, insulin, exercise and adrenaline also regulate intracellular concentration of glucose 6-phosphate which will influence in vivo glycogen synthase activity. Importantly, type 2 diabetes is associated with reduced insulin-stimulated glycogen synthase activation. The nine phosphorylation sites theoretically allow 512 combinations of phosphorylation configurations of glycogen synthase with different kinetic properties. However, due to hierarchal phosphorylation, the number of configurations in vivo is most likely much lower. Unfortunately, many studies only report data on glycogen synthase activity measured with high concentration of UDP-glucose which holds back information about changes in substrate affinity. In this paper we discuss the physiological regulation of glycogen synthase phosphorylation and how the phosphorylation pattern regulates glycogen synthase kinetic properties.
Collapse
Affiliation(s)
- Jørgen Jensen
- Department of Physiology, National Institute of Occupational Health, Thiruvallur, Oslo, Norway.
| | | |
Collapse
|
50
|
McBride A, Ghilagaber S, Nikolaev A, Hardie DG. The glycogen-binding domain on the AMPK beta subunit allows the kinase to act as a glycogen sensor. Cell Metab 2009; 9:23-34. [PMID: 19117544 PMCID: PMC2642990 DOI: 10.1016/j.cmet.2008.11.008] [Citation(s) in RCA: 325] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Revised: 10/22/2008] [Accepted: 11/14/2008] [Indexed: 11/02/2022]
Abstract
AMPK beta subunits contain a conserved domain that causes association with glycogen. Although glycogen availability is known to affect AMPK regulation in vivo, the molecular mechanism for this has not been clear. We now show that AMPK is inhibited by glycogen, particularly preparations with high branching content. We synthesized a series of branched oligosaccharides and show that those with a single alpha1-->6 branch are allosteric inhibitors that also inhibit phosphorylation by upstream kinases. Removal of the outer chains of glycogen using phosphorylase, thus exposing the outer branches, renders inhibition of AMPK more potent. Inhibition by all carbohydrates tested was dependent on the glycogen-binding domain being abolished by mutation of residues required for carbohydrate binding. Our results suggest the hypothesis that AMPK, as well as monitoring immediate energy availability by sensing AMP/ATP, may also be able to sense the status of cellular energy reserves in the form of glycogen.
Collapse
Affiliation(s)
- Andrew McBride
- Division of Molecular Physiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | | | | | | |
Collapse
|