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Liu X, Gilbert RG. Normal and abnormal glycogen structure - A review. Carbohydr Polym 2024; 338:122195. [PMID: 38763710 DOI: 10.1016/j.carbpol.2024.122195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/18/2024] [Accepted: 04/20/2024] [Indexed: 05/21/2024]
Abstract
Glycogen, a complex branched glucose polymer, is found in animals and bacteria, where it serves as an energy storage molecule. It has linear (1 → 4)-α glycosidic bonds between anhydroglucose monomer units, with branch points connected by (1 → 6)-α bonds. Individual glycogen molecules are referred to as β particles. In organs like the liver and heart, these β particles can bind into larger aggregate α particles, which exhibit a rosette-like morphology. The mechanisms and bonding underlying the aggregation process are not fully understood. For example, mammalian liver glycogen has been observed to be molecularly fragile under certain conditions, such as glycogen from diabetic livers fragmenting when exposed to dimethyl sulfoxide (DMSO), while glycogen from healthy livers is much less fragile; this indicates some difference, as yet unknown, in the bonding between β particles in healthy and diabetic glycogen. This fragility may have implications for blood sugar regulation, especially in pathological conditions such as diabetes.
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Affiliation(s)
- Xin Liu
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory, and Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China; Centre for Nutrition & Food Sciences, Queensland Alliance for Agriculture & Food Innovations (QAAFI), The University of Queensland, QLD 4072, Australia
| | - Robert G Gilbert
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Zhongshan Biological Breeding Laboratory, and Jiangsu Key Laboratory of Crop Genetics and Physiology, College of Agriculture, Yangzhou University, Yangzhou 225009, China; Centre for Nutrition & Food Sciences, Queensland Alliance for Agriculture & Food Innovations (QAAFI), The University of Queensland, QLD 4072, Australia.
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2
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Zhuo S, Bai M, Wang Z, Chen L, Li Z, Zhu X, Chen J, Ye X, Guo C, Chen Y. Glycogen synthesis is required for adaptive thermogenesis in beige adipose tissue and affects diet-induced obesity. Am J Physiol Endocrinol Metab 2024; 326:E696-E708. [PMID: 38568151 DOI: 10.1152/ajpendo.00074.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/18/2024] [Accepted: 03/22/2024] [Indexed: 05/15/2024]
Abstract
Glycogen is a form of energy storage for glucose in different tissues such as liver and skeletal muscle. It remains incompletely understood how glycogen impacts on adipose tissue functionality. Cold exposure elevated the expression of Gys1 that encodes glycogen synthase 1 in brown adipose tissue (BAT) and inguinal white adipose tissue (iWAT). The in vivo function of Gys1 was analyzed using a mouse model in which Gys1 was deleted specifically in adipose tissues. Under normal chow conditions, Gys1 deletion caused little changes to body weight and glucose metabolism. Deletion of Gys1 abrogated upregulation of UCP1 and other thermogenesis-related genes in iWAT upon prolonged cold exposure or treatment with β3-adrenergic receptor agonist CL-316,243. Stimulation of UCP1 by CL-316,243 in adipose-derived stromal cells (stromal vascular fractions, SVFs) was also reduced by Gys1 deletion. Both the basal glycogen content and CL-316,243-stimulated glycogen accumulation in adipose tissues were reduced by Gys1 deletion. High-fat diet-induced obesity and insulin resistance were aggravated in Gys1-deleted mice. The loss of body weight upon CL-316,243 treatment was also abrogated by the loss of Gys1. In conclusion, our results underscore the pivotal role of glycogen synthesis in adaptive thermogenesis in beige adipose tissue and its impact on diet-induced obesity in mice.NEW & NOTEWORTHY Glycogen is one of major types of fuel reserve in the body and its classical function is to maintain blood glucose level. This study uncovers that glycogen synthesis is required for beige fat tissue to generate heat upon cold exposure. Such a function of glycogen is linked to development of high-fat diet-induced obesity, thus extending our understanding about the physiological functions of glycogen.
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Affiliation(s)
- Shixuan Zhuo
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
| | - Meijuan Bai
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
| | - Zinan Wang
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
| | - Lingling Chen
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
| | - Zixuan Li
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
| | - Xinyu Zhu
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
| | - Jinzhu Chen
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
| | - Xiaoyi Ye
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
| | - Cheng Guo
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
| | - Yan Chen
- CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and HealthUniversity of Chinese Academy of Sciences, Chinese Academy of SciencesShanghaiPeople's Republic of China
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3
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Marty-Lombardi S, Lu S, Ambroziak W, Schrenk-Siemens K, Wang J, DePaoli-Roach AA, Hagenston AM, Wende H, Tappe-Theodor A, Simonetti M, Bading H, Okun JG, Kuner R, Fleming T, Siemens J. Neuron-astrocyte metabolic coupling facilitates spinal plasticity and maintenance of inflammatory pain. Nat Metab 2024; 6:494-513. [PMID: 38443593 DOI: 10.1038/s42255-024-01001-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 01/31/2024] [Indexed: 03/07/2024]
Abstract
Long-lasting pain stimuli can trigger maladaptive changes in the spinal cord, reminiscent of plasticity associated with memory formation. Metabolic coupling between astrocytes and neurons has been implicated in neuronal plasticity and memory formation in the central nervous system, but neither its involvement in pathological pain nor in spinal plasticity has been tested. Here we report a form of neuroglia signalling involving spinal astrocytic glycogen dynamics triggered by persistent noxious stimulation via upregulation of the Protein Targeting to Glycogen (PTG) in spinal astrocytes. PTG drove glycogen build-up in astrocytes, and blunting glycogen accumulation and turnover by Ptg gene deletion reduced pain-related behaviours and promoted faster recovery by shortening pain maintenance in mice. Furthermore, mechanistic analyses revealed that glycogen dynamics is a critically required process for maintenance of pain by facilitating neuronal plasticity in spinal lamina 1 neurons. In summary, our study describes a previously unappreciated mechanism of astrocyte-neuron metabolic communication through glycogen breakdown in the spinal cord that fuels spinal neuron hyperexcitability.
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Affiliation(s)
| | - Shiying Lu
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- Oliver Wyman GmbH, Munich, Germany
| | - Wojciech Ambroziak
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- Department of Translational Disease Understanding, Grünenthal GmbH, Aachen, Germany
| | | | - Jialin Wang
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Anna A DePaoli-Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Anna M Hagenston
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany
| | - Hagen Wende
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- Taconic Biosciences, Leverkusen, Germany
| | | | - Manuela Simonetti
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Hilmar Bading
- Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany
| | - Jürgen G Okun
- Dietmar-Hopp-Metabolic Center, Division of Neuropaediatrics and Metabolic Medicine, Heidelberg University, Heidelberg, Germany
| | - Rohini Kuner
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- Molecular Medicine Partnership Unit (MMPU), European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Thomas Fleming
- Department of Endocrinology, Diabetology, Metabolism and Clinical Chemistry (Internal Medicine 1), Heidelberg University Hospital, Heidelberg, Germany
- German Center of Diabetes Research (DZD), Neuherberg, Germany
| | - Jan Siemens
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany.
- Molecular Medicine Partnership Unit (MMPU), European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
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Fushuku S, Ushikai M, Arimura E, Komaki Y, Horiuchi M. Acute repeated cage exchange stress modifies urinary stress and plasma metabolic profiles in male mice. PLoS One 2023; 18:e0292649. [PMID: 37815996 PMCID: PMC10564260 DOI: 10.1371/journal.pone.0292649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 09/25/2023] [Indexed: 10/12/2023] Open
Abstract
Exposure to a novel environment is psychologically and physically stressful for humans and animals. The response has been reported to involve enhanced sympathetic nervous system activity, but changes in nutrient levels under stress are not fully understood. As a form of exposure to a novel environment, repeated cage exchange (CE, four times at 2-h intervals for 8 h from 08:00 h) during the light phase with no restraint on movement was applied to A/J mice, a strain particularly prone to stress. Body temperature was measured with a temperature-sensing microchip implanted in the interscapular region. The stress conditions and anxiety level were evaluated by measuring urinary catecholamines and corticosterone and by performing an anxiety-like behavior test, respectively. Major nutrients such as glucose, fatty acids, and amino acids in the plasma were also examined. CE mice showed a significant increase in body temperature with each CE. They also showed a significantly greater reduction of body weight change, more water intake, and higher levels of urinary catecholamines and corticosterone and anxiety-like behavior score than control mice. The model revealed a significantly lower plasma glucose level and higher levels of several essential amino acids, such as branched-chain amino acids and phenylalanine, than those of control mice. Meanwhile, free fatty acids and several amino acids such as arginine, aspartic acid, proline, threonine, and tryptophan in both sets of mice were significantly decreased from the corresponding levels at 08:00 h, while similar plasma levels were exhibited between mice with and without CE. In conclusion, repeated CE stress was associated with changes in glucose and amino acids in plasma. Although further study is needed to clarify how these changes are specifically linked to anxiety-like behavior, this study suggests the potential for nutritional intervention to counter stress in humans exposed to novel environments.
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Affiliation(s)
- Sayuri Fushuku
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Miharu Ushikai
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Emi Arimura
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
- Major in Food and Nutrition, Department of Life and Environmental Science, Kagoshima Prefectural College, Kagoshima, Japan
| | - Yuga Komaki
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Masahisa Horiuchi
- Department of Hygiene and Health Promotion Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
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5
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Liebscher G, Vujic N, Schreiber R, Heine M, Krebiehl C, Duta-Mare M, Lamberti G, de Smet CH, Hess MW, Eichmann TO, Hölzl S, Scheja L, Heeren J, Kratky D, Huber LA. The lysosomal LAMTOR / Ragulator complex is essential for nutrient homeostasis in brown adipose tissue. Mol Metab 2023; 71:101705. [PMID: 36907508 PMCID: PMC10074977 DOI: 10.1016/j.molmet.2023.101705] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 02/28/2023] [Accepted: 03/06/2023] [Indexed: 03/13/2023] Open
Abstract
OBJECTIVE In brown adipose tissue (iBAT), the balance between lipid/glucose uptake and lipolysis is tightly regulated by insulin signaling. Downstream of the insulin receptor, PDK1 and mTORC2 phosphorylate AKT, which activates glucose uptake and lysosomal mTORC1 signaling. The latter requires the late endosomal/lysosomal adaptor and MAPK and mTOR activator (LAMTOR/Ragulator) complex, which serves to translate the nutrient status of the cell to the respective kinase. However, the role of LAMTOR in metabolically active iBAT has been elusive. METHODS Using an AdipoqCRE-transgenic mouse line, we deleted LAMTOR2 (and thereby the entire LAMTOR complex) in adipose tissue (LT2 AKO). To examine the metabolic consequences, we performed metabolic and biochemical studies in iBAT isolated from mice housed at different temperatures (30 °C, room temperature and 5 °C), after insulin treatment, or in fasted and refed condition. For mechanistic studies, mouse embryonic fibroblasts (MEFs) lacking LAMTOR 2 were analyzed. RESULTS Deletion of the LAMTOR complex in mouse adipocytes resulted in insulin-independent AKT hyperphosphorylation in iBAT, causing increased glucose and fatty acid uptake, which led to massively enlarged lipid droplets. As LAMTOR2 was essential for the upregulation of de novo lipogenesis, LAMTOR2 deficiency triggered exogenous glucose storage as glycogen in iBAT. These effects are cell autonomous, since AKT hyperphosphorylation was abrogated by PI3K inhibition or by deletion of the mTORC2 component Rictor in LAMTOR2-deficient MEFs. CONCLUSIONS We identified a homeostatic circuit for the maintenance of iBAT metabolism that links the LAMTOR-mTORC1 pathway to PI3K-mTORC2-AKT signaling downstream of the insulin receptor.
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Affiliation(s)
- Gudrun Liebscher
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Nemanja Vujic
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6, 8010 Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Caroline Krebiehl
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Madalina Duta-Mare
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6, 8010 Graz, Austria
| | - Giorgia Lamberti
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Cedric H de Smet
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Michael W Hess
- Institute of Histology and Embryology, Medical University of Innsbruck, Müllerstrasse 59, 6020 Innsbruck, Austria
| | - Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31, 8010 Graz, Austria
| | - Sarah Hölzl
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | - Ludger Scheja
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Dagmar Kratky
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstr. 6, 8010 Graz, Austria; BioTechMed-Graz, Mozartgasse 12, 8010 Graz, Austria
| | - Lukas A Huber
- Division of Cell Biology, Biocenter, Medical University Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria.
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Impaired mitophagy in Sanfilippo a mice causes hypertriglyceridemia and brown adipose tissue activation. J Biol Chem 2022; 298:102159. [PMID: 35750212 PMCID: PMC9364035 DOI: 10.1016/j.jbc.2022.102159] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 06/08/2022] [Accepted: 06/09/2022] [Indexed: 11/25/2022] Open
Abstract
Lysosomal storage diseases result in various developmental and physiological complications, including cachexia. To study the causes for the negative energy balance associated with cachexia, we assessed the impact of sulfamidase deficiency and heparan sulfate storage on energy homeostasis and metabolism in a mouse model of type IIIa mucopolysaccharidosis (MPS IIIa, Sanfilippo A syndrome). At 12-weeks of age, MPS IIIa mice exhibited fasting and postprandial hypertriglyceridemia compared with wildtype mice, with a reduction of white and brown adipose tissues. Partitioning of dietary [3H]triolein showed a marked increase in intestinal uptake and secretion, whereas hepatic production and clearance of triglyceride-rich lipoproteins did not differ from wildtype controls. Uptake of dietary triolein was also elevated in brown adipose tissue (BAT), and notable increases in beige adipose tissue occurred, resulting in hyperthermia, hyperphagia, hyperdipsia, and increased energy expenditure. Furthermore, fasted MPS IIIa mice remained hyperthermic when subjected to low temperature but became cachexic and profoundly hypothermic when treated with a lipolytic inhibitor. We demonstrated that the reliance on increased lipid fueling of BAT was driven by a reduced ability to generate energy from stored lipids within the depot. These alterations arose from impaired autophagosome-lysosome fusion, resulting in increased mitochondria content in beige and BAT. Finally, we show that increased mitochondria content in BAT and postprandial dyslipidemia was partially reversed upon 5-week treatment with recombinant sulfamidase. We hypothesize that increased BAT activity and persistent increases in energy demand in MPS IIIa mice contribute to the negative energy balance observed in patients with MPS IIIa.
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7
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Choi S. Glycogen as a Regulator of White Fat Browning. Mol Cells 2022; 45:177-179. [PMID: 35387897 PMCID: PMC9001150 DOI: 10.14348/molcells.2022.2050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 01/12/2022] [Indexed: 11/27/2022] Open
Affiliation(s)
- Seri Choi
- Division of Life Sciences, BK21 FOUR R&E Center for Life Sciences, Korea University, Seoul 02841, Korea
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8
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Glycogen metabolism links glucose homeostasis to thermogenesis in adipocytes. Nature 2021; 599:296-301. [PMID: 34707293 PMCID: PMC9186421 DOI: 10.1038/s41586-021-04019-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 09/13/2021] [Indexed: 12/13/2022]
Abstract
Adipocytes increase energy expenditure in response to prolonged sympathetic activation via persistent expression of uncoupling protein 1 (UCP1)1,2. Here we report that the regulation of glycogen metabolism by catecholamines is critical for UCP1 expression. Chronic β-adrenergic activation leads to increased glycogen accumulation in adipocytes expressing UCP1. Adipocyte-specific deletion of a scaffolding protein, protein targeting to glycogen (PTG), reduces glycogen levels in beige adipocytes, attenuating UCP1 expression and responsiveness to cold or β-adrenergic receptor-stimulated weight loss in obese mice. Unexpectedly, we observed that glycogen synthesis and degradation are increased in response to catecholamines, and that glycogen turnover is required to produce reactive oxygen species leading to the activation of p38 MAPK, which drives UCP1 expression. Thus, glycogen has a key regulatory role in adipocytes, linking glucose metabolism to thermogenesis.
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9
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Uncovering the Role of Glycogen in Brown Adipose Tissue. Pharm Res 2021; 38:9-14. [PMID: 33433776 DOI: 10.1007/s11095-020-02979-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 12/21/2020] [Indexed: 10/22/2022]
Abstract
The presence of glycogen in the brown adipose tissue (BAT) has been described 60 years ago. However, the role of this energetic storage in brown adipocytes has been long time underestimated. We have recently shown that during brown adipocyte differentiation in the embryo, glycogen accumulates and is degraded by glycophagy, a dynamic essential for lipid droplets biogenesis. Recent studies have shown that the storage and degradation of triglycerides in BAT are not essential for the activation of BAT in response to cold exposure in adults, and that glycogen can compensate for their absence. In this review, we report the recent advances related to the importance of glycogen in brown adipocytes.
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10
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Qian S, Tang Y, Tang QQ. Adipose tissue plasticity and the pleiotropic roles of BMP signaling. J Biol Chem 2021; 296:100678. [PMID: 33872596 PMCID: PMC8131923 DOI: 10.1016/j.jbc.2021.100678] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 04/11/2021] [Accepted: 04/15/2021] [Indexed: 12/15/2022] Open
Abstract
Adipose tissues, including white, beige, and brown adipose tissue, have evolved to be highly dynamic organs. Adipose tissues undergo profound changes during development and regeneration and readily undergo remodeling to meet the demands of an everchanging metabolic landscape. The dynamics are determined by the high plasticity of adipose tissues, which contain various cell types: adipocytes, immune cells, endothelial cells, nerves, and fibroblasts. There are numerous proteins that participate in regulating the plasticity of adipose tissues. Among these, bone morphogenetic proteins (BMPs) were initially found to regulate the differentiation of adipocytes, and they are being reported to have pleiotropic functions by emerging studies. Here, in the first half of the article, we summarize the plasticity of adipocytes and macrophages, which are two groups of cells targeted by BMP signaling in adipose tissues. We then review how BMPs regulate the differentiation, death, and lipid metabolism of adipocytes. In addition, the potential role of BMPs in regulating adipose tissue macrophages is considered. Finally, the expression of BMPs in adipose tissues and their metabolic relevance are discussed.
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Affiliation(s)
- Shuwen Qian
- The Key Laboratory of Metabolism and Molecular Medicine of the Ministry of Education, Department of Biochemistry and Molecular Biology of School of Basic Medical Sciences, and Department of Endocrinology and Metabolism of Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yan Tang
- The Key Laboratory of Metabolism and Molecular Medicine of the Ministry of Education, Department of Biochemistry and Molecular Biology of School of Basic Medical Sciences, and Department of Endocrinology and Metabolism of Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qi-Qun Tang
- The Key Laboratory of Metabolism and Molecular Medicine of the Ministry of Education, Department of Biochemistry and Molecular Biology of School of Basic Medical Sciences, and Department of Endocrinology and Metabolism of Zhongshan Hospital, Fudan University, Shanghai, China.
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11
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Okamatsu-Ogura Y, Kuroda M, Tsutsumi R, Tsubota A, Saito M, Kimura K, Sakaue H. UCP1-dependent and UCP1-independent metabolic changes induced by acute cold exposure in brown adipose tissue of mice. Metabolism 2020; 113:154396. [PMID: 33065161 DOI: 10.1016/j.metabol.2020.154396] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/15/2020] [Accepted: 09/28/2020] [Indexed: 11/18/2022]
Abstract
BACKGROUND Brown adipose tissue (BAT) is a site of metabolic thermogenesis mediated by mitochondrial uncoupling protein 1 (UCP1) and represents a target for a therapeutic intervention in obesity. Cold exposure activates UCP1-mediated thermogenesis in BAT and causes drastic changes in glucose, lipid, and amino acid metabolism; however, the relationship between these metabolic changes and UCP1-mediated thermogenesis is not fully understood. METHODS We conducted metabolomic and GeneChip array analyses of BAT after 4-h exposure to cold temperature (10 °C) in wild-type (WT) and UCP1-KO mice. RESULTS Cold exposure largely increased metabolites of the glycolysis pathway and lactic acid levels in WT, but not in UCP1-KO, mice, indicating that aerobic glycolysis is enhanced as a consequence of UCP1-mediated thermogenesis. GeneChip array analysis of BAT revealed that there were 2865 genes upregulated by cold exposure in WT mice, and 838 of these were upregulated and 74 were downregulated in UCP1-KO mice. Pathway analysis revealed the enrichment of genes involved in fatty acid (FA) β oxidation and triglyceride (TG) synthesis in both WT and UCP1-KO mice, suggesting that these metabolic pathways were enhanced by cold exposure independently of UCP1-mediated thermogenesis. FA and cholesterol biosynthesis pathways were enhanced only in UCP1-KO mice. Cold exposure also significantly increased the BAT content of proline, tryptophan, and phenylalanine amino acids in both WT and UCP1-KO mice. In WT mice, cold exposure significantly increased glutamine content and enhanced the expression of genes related to glutamine metabolism. Surprisingly, aspartate was almost completely depleted after cold exposure in UCP1-KO mice. Gene expression analysis suggested that aspartate was actively utilized after cold exposure both in WT and UCP1-KO mice, but it was replenished from intracellular N-acetyl-aspartate in WT mice. CONCLUSIONS These results revealed that cold exposure induces UCP1-mediated thermogenesis-dependent glucose utilization and UCP1-independent active lipid metabolism in BAT. In addition, cold exposure largely affects amino acid metabolism in BAT, especially UCP1-dependently enhances glutamine utilization. These results contribute a comprehensive understanding of UCP1-mediated thermogenesis-dependent and thermogenesis-independent metabolism in BAT.
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Affiliation(s)
- Yuko Okamatsu-Ogura
- Laboratory of Biochemistry, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan.
| | - Masashi Kuroda
- Department of Nutrition and Metabolism, Institute of Health Biosciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Rie Tsutsumi
- Department of Nutrition and Metabolism, Institute of Health Biosciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
| | - Ayumi Tsubota
- Laboratory of Biochemistry, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Masayuki Saito
- Laboratory of Biochemistry, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Kazuhiro Kimura
- Laboratory of Biochemistry, Faculty of Veterinary Medicine, Hokkaido University, Sapporo 060-0818, Japan
| | - Hiroshi Sakaue
- Department of Nutrition and Metabolism, Institute of Health Biosciences, Tokushima University Graduate School, Tokushima 770-8503, Japan
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12
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Mayeuf-Louchart A, Lancel S, Sebti Y, Pourcet B, Loyens A, Delhaye S, Duhem C, Beauchamp J, Ferri L, Thorel Q, Boulinguiez A, Zecchin M, Dubois-Chevalier J, Eeckhoute J, Vaughn LT, Roach PJ, Dani C, Pederson BA, Vincent SD, Staels B, Duez H. Glycogen Dynamics Drives Lipid Droplet Biogenesis during Brown Adipocyte Differentiation. Cell Rep 2020; 29:1410-1418.e6. [PMID: 31693883 PMCID: PMC7057258 DOI: 10.1016/j.celrep.2019.09.073] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 08/02/2019] [Accepted: 09/25/2019] [Indexed: 12/20/2022] Open
Abstract
Browning induction or transplantation of brown adipose tissue (BAT) or brown/beige adipocytes derived from progenitor or induced pluripotent stem cells (iPSCs) can represent a powerful strategy to treat metabolic diseases. However, our poor understanding of the mechanisms that govern the differentiation and activation of brown adipocytes limits the development of such therapy. Various genetic factors controlling the differentiation of brown adipocytes have been identified, although most studies have been performed using in vitro cultured pre-adipocytes. We investigate here the differentiation of brown adipocytes from adipose progenitors in the mouse embryo. We demonstrate that the formation of multiple lipid droplets (LDs) is initiated within clusters of glycogen, which is degraded through glycophagy to provide the metabolic substrates essential for de novo lipogenesis and LD formation. Therefore, this study uncovers the role of glycogen in the generation of LDs. Brown adipocytes are functionally differentiated at E17.5 in the mouse embryo Lipid droplets are formed within glycogen clusters Glycogen production is crucial for lipid droplet biogenesis during BAT differentiation Glycophagy-mediated glycogen degradation drives lipid droplet formation
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Affiliation(s)
- Alicia Mayeuf-Louchart
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France.
| | - Steve Lancel
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Yasmine Sebti
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Benoit Pourcet
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Anne Loyens
- Univ. Lille, UMR-S 1172-JPArc Centre de Recherche Jean-Pierre Aubert Neurosciences et Cancer, Lille, France
| | - Stéphane Delhaye
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Christian Duhem
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Justine Beauchamp
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Lise Ferri
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Quentin Thorel
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Alexis Boulinguiez
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Mathilde Zecchin
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Julie Dubois-Chevalier
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Jérôme Eeckhoute
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Logan T Vaughn
- Indiana University School of Medicine-Muncie and Ball State University, Muncie, IN 47306, USA
| | - Peter J Roach
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Christian Dani
- Université Côte d'Azur, CNRS, INSERM, iBV Faculté de Médecine, Nice, France
| | - Bartholomew A Pederson
- Indiana University School of Medicine-Muncie and Ball State University, Muncie, IN 47306, USA
| | - Stéphane D Vincent
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France; Centre National de la Recherche Scientifique, UMR7104, Illkirch, France; Institut National de la Santé et de la Recherche Médicale, U1258 Illkirch, France; Université de Strasbourg, Illkirch, France
| | - Bart Staels
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
| | - Hélène Duez
- Univ. Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U1011-EGID, 59000 Lille, France
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Huska B, Niccoli S, Phenix CP, Lees SJ. Leucine Potentiates Glucose-mediated 18F-FDG Uptake in Brown Adipose Tissue via β-Adrenergic Activation. Biomedicines 2020; 8:biomedicines8060159. [PMID: 32545834 PMCID: PMC7345234 DOI: 10.3390/biomedicines8060159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 05/27/2020] [Accepted: 06/10/2020] [Indexed: 01/07/2023] Open
Abstract
Significant depots of brown adipose tissue (BAT) have been identified in many adult humans through positron emission tomography (PET), with the amount of BAT being inversely correlated with obesity. As dietary activation of BAT has implications for whole body glucose metabolism, leucine was used in the present study to determine its ability to promote BAT activation resulting in increased glucose uptake. In order to assess this, 2-deoxy-2-(fluorine-18)fluoro-d-glucose (18F-FDG) uptake was measured in C57BL/6 mice using microPET after treatment with leucine, glucose, or both in interscapular BAT (IBAT). Pretreatment with propranolol (PRP) was used to determine the role of β-adrenergic activation in glucose and leucine-mediated 18F-FDG uptake. Analysis of maximum standardized uptake values (SUVMAX) determined that glucose administration increased 18F-FDG uptake in IBAT by 25.3%. While leucine did not promote 18F-FDG uptake alone, it did potentiate glucose-mediated 18F-FDG uptake, increasing 18F-FDG uptake in IBAT by 22.5%, compared to glucose alone. Pretreatment with PRP prevented the increase in IBAT 18F-FDG uptake following the combination of glucose and leucine administration. These data suggest that leucine is effective in promoting BAT 18F-FDG uptake through β-adrenergic activation in combination with glucose.
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Affiliation(s)
- Brenda Huska
- Biology, Lakehead University, Thunder Bay, ON P7B 5E1, Canada;
| | - Sarah Niccoli
- Medical Sciences, Lakehead University Faculty of Medicine, Thunder Bay, ON P7B 5E1, Canada;
- Northern Ontario School of Medicine, Medical Sciences Division, Thunder Bay, ON P7B 5E1, Canada
| | - Christopher P. Phenix
- Northern Ontario School of Medicine, Medical Sciences Division, Thunder Bay, ON P7B 5E1, Canada
- Chemistry, University of Saskatchewan, Saskatoon, SK S7N 5C9, Canada
- Thunder Bay Regional Health Research Institute, Thunder Bay, ON P7A 7T1, Canada
- Correspondence: (C.P.P.); (S.J.L.); Tel.: +1-(306)-966-4193 (C.P.P.); +1-(807)-766-7435 (S.J.L.); Fax: +1-(306)-966-4730 (C.P.P.); +1-(807)-766-7362 (S.J.L.)
| | - Simon J. Lees
- Biology, Lakehead University, Thunder Bay, ON P7B 5E1, Canada;
- Medical Sciences, Lakehead University Faculty of Medicine, Thunder Bay, ON P7B 5E1, Canada;
- Northern Ontario School of Medicine, Medical Sciences Division, Thunder Bay, ON P7B 5E1, Canada
- Correspondence: (C.P.P.); (S.J.L.); Tel.: +1-(306)-966-4193 (C.P.P.); +1-(807)-766-7435 (S.J.L.); Fax: +1-(306)-966-4730 (C.P.P.); +1-(807)-766-7362 (S.J.L.)
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Jia J, Qin J, Yuan X, Liao Z, Huang J, Wang B, Sun C, Li W. Microarray and metabolome analysis of hepatic response to fasting and subsequent refeeding in zebrafish (Danio rerio). BMC Genomics 2019; 20:919. [PMID: 31791229 PMCID: PMC6889435 DOI: 10.1186/s12864-019-6309-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 11/19/2019] [Indexed: 02/08/2023] Open
Abstract
Background Compensatory growth refers to the phenomenon in which organisms grow faster after the improvement of an adverse environment and is thought to be an adaptive evolution to cope with the alleviation of the hostile environment. Many fish have the capacity for compensatory growth, but the underlying cellular mechanisms remain unclear. In the present study, microarray and nontargeted metabolomics were performed to characterize the transcriptome and metabolome of zebrafish liver during compensatory growth. Results Zebrafish could regain the weight they lost during 3 weeks of fasting and reach a final weight similar to that of fish fed ad libitum when refed for 15 days. When refeeding for 3 days, the liver displayed hyperplasia accompanied with decreased triglyceride contents and increased glycogen contents. The microarray results showed that when food was resupplied for 3 days, the liver TCA cycle (Tricarboxylic acid cycle) and oxidative phosphorylation processes were upregulated, while DNA replication and repair, as well as proteasome assembly were also activated. Integration of transcriptome and metabolome data highlighted transcriptionally driven alterations in metabolism during compensatory growth, such as altered glycolysis and lipid metabolism activities. The metabolome data also implied the participation of amino acid metabolism during compensatory growth in zebrafish liver. Conclusion Our study provides a global resource for metabolic adaptations and their transcriptional regulation during refeeding in zebrafish liver. This study represents a first step towards understanding of the impact of metabolism on compensatory growth and will potentially aid in understanding the molecular mechanism associated with compensatory growth.
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Affiliation(s)
- Jirong Jia
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, No.135 Xingang West Road, Guangzhou, 510275, China
| | - Jingkai Qin
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, No.135 Xingang West Road, Guangzhou, 510275, China
| | - Xi Yuan
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, No.135 Xingang West Road, Guangzhou, 510275, China
| | - Zongzhen Liao
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, No.135 Xingang West Road, Guangzhou, 510275, China
| | - Jinfeng Huang
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, No.135 Xingang West Road, Guangzhou, 510275, China
| | - Bin Wang
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, No.135 Xingang West Road, Guangzhou, 510275, China.,Present address: Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
| | - Caiyun Sun
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, No.135 Xingang West Road, Guangzhou, 510275, China
| | - Wensheng Li
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory for Aquatic Economic Animals, Guangdong Provincial Engineering Technology Research Center for Healthy Breeding of Important Economic Fish, School of Life Sciences, Sun Yat-Sen University, No.135 Xingang West Road, Guangzhou, 510275, China.
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Silva DCPD, Carneiro FD, Almeida KCD, Fernandes-Santos C. Role of miRNAs on the Pathophysiology of Cardiovascular Diseases. Arq Bras Cardiol 2019; 111:738-746. [PMID: 30484515 PMCID: PMC6248252 DOI: 10.5935/abc.20180215] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
MiRNA (or microRNA) is a subclass of non-coding RNAs that is responsible for
post-transcriptional gene regulation. It has approximately 22 nucleotides and
regulates gene expression in plants and animals at the post-transcriptional
level, by the cleavage of a target mRNA or by suppression of its translation.
Although many of the processes and mechanisms have not yet been fully
elucidated, there is a strong association between miRNA expression and several
diseases. It is known that miRNAs are expressed in the cardiovascular system,
but their role in cardiovascular diseases (CVDs) has not been clearly
established. In this non-systematic review of the literature, we first present
the definition of miRNAs and their action at the cellular level. Afterward, we
discuss the role of miRNAs as circulating biomarkers of CVDs, and then their
role in cardiac remodeling and atherosclerosis. Despite the complexity and
challenges, it is crucial to identify deregulated miRNAs in CVDs, as it allows a
better understanding of underlying cellular and molecular mechanisms and helps
in the development of more accurate diagnostic and prognostic circulating
biomarkers, and new therapeutic strategies for different stages of CVDs.
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Affiliation(s)
| | - Felipe Demani Carneiro
- Programa de Pós-graduação em Ciências Cardiovasculares da Universidade Federal Fluminense (UFF), Niterói, RJ - Brazil
| | | | - Caroline Fernandes-Santos
- Programa de Pós-graduação em Ciências Cardiovasculares da Universidade Federal Fluminense (UFF), Niterói, RJ - Brazil
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16
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Schweizer S, Oeckl J, Klingenspor M, Fromme T. Substrate fluxes in brown adipocytes upon adrenergic stimulation and uncoupling protein 1 ablation. Life Sci Alliance 2018; 1:e201800136. [PMID: 30456392 PMCID: PMC6238590 DOI: 10.26508/lsa.201800136] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 11/05/2018] [Accepted: 11/05/2018] [Indexed: 12/22/2022] Open
Abstract
Brown adipocytes are highly specialized cells with the unique metabolic ability to dissipate chemical energy in the form of heat. We determined and inferred the flux of a number of key catabolic metabolites, their changes in response to adrenergic stimulation, and the dependency on the presence of the thermogenic uncoupling protein 1 and/or oxidative phosphorylation. This study provides reference values to approximate flux rates from a limited set of measured parameters in the future and thereby allows to evaluate the plausibility of claims about the capacity of metabolic adaptations or manipulations. From the resulting model, we delineate that in brown adipocytes (1) free fatty acids are a significant contributor to extracellular acidification, (2) glycogen is the dominant glycolytic substrate source in the acute response to an adrenergic stimulus, and (3) the futile cycling of free fatty acids between lipolysis and re-esterification into triglyceride provides a mechanism for uncoupling protein 1-independent, non-shivering thermogenesis in brown adipocytes.
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Affiliation(s)
- Sabine Schweizer
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Josef Oeckl
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany.,EKFZ-Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany.,ZIEL-Institute for Food and Health, Technical University of Munich, Freising, Germany
| | - Martin Klingenspor
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany.,EKFZ-Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany.,ZIEL-Institute for Food and Health, Technical University of Munich, Freising, Germany
| | - Tobias Fromme
- Chair of Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany.,EKFZ-Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Freising, Germany
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The effect of starvation and re-feeding on vasotocinergic and isotocinergic pathways in immature gilthead sea bream (Sparus aurata). J Comp Physiol B 2017; 187:945-958. [DOI: 10.1007/s00360-017-1064-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 02/07/2017] [Accepted: 02/09/2017] [Indexed: 12/25/2022]
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Al-Kuraishy HM, Al-Gareeb AI. Erectile Dysfunction and Low Sex Drive in Men with Type 2 DM: The Potential Role of Diabetic Pharmacotherapy. J Clin Diagn Res 2016; 10:FC21-FC26. [PMID: 28208875 DOI: 10.7860/jcdr/2016/19971.8996] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 09/17/2016] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Diabetic men with erectile dysfunction have not been widely studied. They have low testosterone levels, causing low sex drive and erectile dysfunction. AIM To assess the erectile dysfunction and sex drive in relation to testosterone serum levels in type 2 Diabetes Mellitus (DM) patients. MATERIALS AND METHODS A total of 64 patients with type 2 DM were enrolled in this cross-sectional study, according to the treatment types they were divided into three groups, group (A): 34 patients treated with metformin, group (B): 30 patients treated with sulfonylurea and group (C): 27 healthy normal non-diabetic men are taken as control. Total testosterone (TT), Free Testosterone (FT), Free Androgenic Index (FAI), Sex Hormone Binding Globulin (SHBG), lipid profile and anthropometric parameters in metformin and sulfonylurea treated patients were compared to normal healthy men along with Sexual Health Inventory for Men (SHIM). RESULTS Total testosterone serum levels were high in sulfonylurea treated patients as compared to metformin treated patients' p < 0.0001. Similarly, SHBG levels were significantly higher in sulfonylurea treated patients compared to metformin treated patients p < 0.0001. FT was also significantly higher in sulfonylurea treated patients compared to metformin treated patients p =0.014 and significantly low compared to the control p =0.0002. FAI was also significantly higher in sulfonylurea treated patients compared to metformin treated patients p < 0.0001. On other hand Bioavailable testosterone (BT) was low in metformin treated patients (2.75±1.12 nmol/L) compared to the control p< 0.0001. SHIM was low in metformin treated patients 10.61±3.22 which significantly differed from control and sulfonylurea treated patients p< 0.0001, intergroup differences was significant p=0.001. CONCLUSION Metformin leads to significant reduction in testosterone levels, sex drive and induction of low testosterone-induced erectile dysfunction, whereas; sulfonylurea leads to significant elevation in testosterone levels, sex drive and erectile function.
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Affiliation(s)
- Hayder M Al-Kuraishy
- Assistant Professor, Department of Pharmacology, College of Medicine, Al-Mustansiriya University , P.O. Box 14132, Baghdad, Iraq
| | - Ali I Al-Gareeb
- Assistant Professor, Department of Pharmacology, College of Medicine, Al-Mustansiriya University , P.O. Box 14132, Baghdad, Iraq
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Glycogen Repletion in Brown Adipose Tissue upon Refeeding Is Primarily Driven by Phosphorylation-Independent Mechanisms. PLoS One 2016; 11:e0156148. [PMID: 27213961 PMCID: PMC4877058 DOI: 10.1371/journal.pone.0156148] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 05/10/2016] [Indexed: 12/30/2022] Open
Abstract
Glycogen storage in brown adipose tissue (BAT) is generally thought to take place through passive, substrate-driven activation of glycogenesis rather than programmatic shifts favoring or opposing the storage and/or retention of glycogen. This perception exists despite a growing body of evidence suggesting that BAT glycogen storage is actively regulated by covalent modification of key glycogen-metabolic enzymes, protein turnover, and endocrine hormone signaling. Members of one such class of covalent-modification regulators, glycogen-binding Phosphoprotein Phosphatase-1 (PP1)-regulatory subunits (PPP1Rs), targeting PP1 to glycogen-metabolic enzymes, were dynamically regulated in response to 24 hr of starvation and/or 24 hr of starvation followed by ad libitum refeeding. Over-expression of the PPP1R Protein Targeting to Glycogen (PTG), under the control of the aP2 promoter in mice, inactivated glycogen phosphorylase (GP) and enhanced basal- and starvation-state glycogen storage. Total interscapular BAT glycogen synthase and the constitutive activity of GS were conditionally affected. During starvation, glucose-6-phosphate (G-6-P) levels and the relative phosphorylation of Akt (p-Ser-473-Akt) were both increased in PTG-overexpressing (Tg) mice, suggesting that elevated glycogen storage during starvation modifies broader cellular metabolic pathways. During refeeding, Tg and WT mice reaccumulated glycogen similarly despite altered GS and GP activities. All observations during refeeding suggest that the phosphorylation states of GS and GP are not physiologically rate-controlling, despite there being a clear balance of endogenous kinase- and phosphatase activities. The studies presented here reveal IBAT glycogen storage to be a tightly-regulated process at all levels, with potential effects on nutrient sensing in vivo.
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