1
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Tan X, Wang Z, Cheung U, Hu Z, Liu Q, Wang L, Sullivan MA, Cozzolino D, Gilbert RG. Liver glycogen fragility in the presence of hydrogen-bond breakers. Int J Biol Macromol 2024; 268:131741. [PMID: 38649083 DOI: 10.1016/j.ijbiomac.2024.131741] [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: 10/27/2023] [Accepted: 04/19/2024] [Indexed: 04/25/2024]
Abstract
Glycogen, a complex branched glucose polymer, is responsible for sugar storage in blood glucose homeostasis. It comprises small β particles bound together into composite α particles. In diabetic livers, α particles are fragile, breaking apart into smaller particles in dimethyl sulfoxide, DMSO; they are however stable in glycogen from healthy animals. We postulate that the bond between β particles in α particles involves hydrogen bonding. Liver-glycogen fragility in normal and db/db mice (an animal model for diabetes) is compared using various hydrogen-bond breakers (DMSO, guanidine and urea) at different temperatures. The results showed different degrees of α-particle disruption. Disrupted glycogen showed changes in the mid-infra-red spectrum that are related to hydrogen bonds. While glycogen α-particles are only fragile under harsh, non-physiological conditions, these results nevertheless imply that the bonding between β particles in α particles is different in diabetic livers compared to healthy, and is probably associated with hydrogen bonding.
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Affiliation(s)
- Xinle Tan
- Centre for Animal Science, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Ziyi Wang
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Ut Cheung
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Zhenxia Hu
- Department of Pharmacy, Shanghai Public Health Clinical Center, Fudan University, Shanghai, China.
| | - Qinghua Liu
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau SAR 999078, China
| | - Liang Wang
- Laboratory Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Mitchell A Sullivan
- Glycation and Diabetes Group, Mater Research Institute, The University of Queensland, Translational Research Institute, Brisbane, Queensland, 4012, Australia.
| | - Daniel Cozzolino
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Robert G Gilbert
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia; Jiangsu Key Laboratory of Crop Genetics and Physiology/State Key Laboratory of Hybrid Rice, College of Agriculture, Yangzhou University, Yangzhou 225009, China; Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China.
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2
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Besford QA. The sweetest polymer nanoparticles: opportunities ahead for glycogen in nanomedicine. SOFT MATTER 2024; 20:3577-3584. [PMID: 38629336 DOI: 10.1039/d4sm00261j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Most cells take simple sugar (α-D-glucose) and assemble it into highly dense polysaccharide nanoparticles called glycogen. This is achieved through the action of multiple coupled-enzymatic reactions, yielding the cellular store of polymerised glucose to be degraded in times of metabolic need. These nanoparticles can be readily isolated from various animal tissues and plants, and are commercially available on a large scale. Importantly, glycogen is highly water soluble, non-toxic, low-fouling, and biodegradable, making it an attractive nanoparticle for use in nanomedicine, for both diagnosing and treating disease. This concept has been pursued actively recently, with exciting results on a variety of fronts, especially for targeting specific tissues and delivering nucleic acid and peptide cargo. In this perspective, the role of glycogen in nanomedicine going forward is discussed, with opportunities highlighted of where these sugary nanoparticles fit into the problem of treating disease.
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Affiliation(s)
- Quinn A Besford
- Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Str. 6, Dresden 01069, Germany.
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3
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Liu X, Zhang P, Gilbert RG. Formation mechanism of α particles in glycogen: Testing the budding hypothesis by Monte-Carlo simulation. Int J Biol Macromol 2024; 263:130332. [PMID: 38401580 DOI: 10.1016/j.ijbiomac.2024.130332] [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: 10/30/2023] [Revised: 02/15/2024] [Accepted: 02/19/2024] [Indexed: 02/26/2024]
Abstract
Glycogen, a complex branched glucose polymer and a blood-sugar reservoir in animals, comprises small β particles joined together into composite α particles. In diabetic animals, α particles fragment more easily than those in healthy animals. Finding evidence for or against postulated mechanisms for α-particle formation is thus important for diabetes research. Insight into this is obtained here using Monte-Carlo simulations, including addition and loss of glucose monomer, branching and debranching, based on earlier simulations which were in acceptable agreement with experiment [Zhang et al., Int J Biol Macromolecules 2018, 116, 264]. One postulated mechanism for α-particle formation is "budding": occasionally a glucan chain temporarily protrudes from the particle, and if its growing end is sufficiently far from its parent particle, it propagates to a new linked particle. We tested this by simulations in which an "artificial" bud (a chain extending well outside the average particle radius) is added to a glycogen molecule in a dynamic steady state, and the system allowed to evolve. In some simulations, the particle reached a new steady state having an irregular dumbbell shape: a rudimentary α particle. Thus 'budding' is a possible mechanism for α particles to form. If no simulations had shown this behaviour, it would have refuted the postulate.
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Affiliation(s)
- Xin Liu
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, Jiangsu Province, China; Co-Innovation Centre for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, Jiangsu Province, China; Centre for Nutrition & Food Sciences, Queensland Alliance for Agriculture & Food Innovations (QAAFI), The University of Queensland, QLD 4072, Australia
| | - Peng Zhang
- School of Electronic Engineering, Tongling University, Tongling 244061, PR China
| | - Robert G Gilbert
- Jiangsu Key Laboratory of Crop Genetics and Physiology, Key Laboratory of Plant Functional Genomics of the Ministry of Education, College of Agriculture, Yangzhou University, Yangzhou 225009, Jiangsu Province, China; Co-Innovation Centre for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, Jiangsu Province, China; Centre for Nutrition & Food Sciences, Queensland Alliance for Agriculture & Food Innovations (QAAFI), The University of Queensland, QLD 4072, Australia.
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4
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Rousset Y, Ebenhöh O, Raguin A. Stochastic modelling of a three-dimensional glycogen granule synthesis and impact of the branching enzyme. PLoS Comput Biol 2023; 19:e1010694. [PMID: 37205718 DOI: 10.1371/journal.pcbi.1010694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 03/25/2023] [Indexed: 05/21/2023] Open
Abstract
In humans, glycogen storage diseases result from metabolic inborn errors, and can lead to severe phenotypes and lethal conditions. Besides these rare diseases, glycogen is also associated to widely spread societal burdens such as diabetes. Glycogen is a branched glucose polymer synthesised and degraded by a complex set of enzymes. Over the past 50 years, the structure of glycogen has been intensively investigated. Yet, the interplay between the detailed three-dimensional glycogen structure and the related enzyme activity is only partially characterised and still to be fully understood. In this article, we develop a stochastic coarse-grained and spatially resolved model of branched polymer biosynthesis following a Gillespie algorithm. Our study largely focusses on the role of the branching enzyme, and first investigates the properties of the model with generic parameter values, before comparing it to in vivo experimental data in mice. It arises that the ratio of glycogen synthase over branching enzyme reaction rates drastically impacts the structure of the granule. We deeply investigate the mechanism of branching and parametrise it using distinct lengths. Not only do we consider various possible sets of values for these lengths, but also distinct rules to apply them. We show how combining various values for these lengths finely tunes glycogen macromolecular structure. Comparing the model with experimental data confirms that we can accurately reproduce glycogen chain length distributions in wild type mice. Additional granule properties obtained for this fit are also in good agreement with typically reported values in the experimental literature. Nonetheless, we find that the mechanism of branching must be more flexible than usually reported. Overall, our model provides a theoretical basis to quantify the effect that single enzymatic parameters, in particular of the branching enzyme, have on the chain length distribution. Our generic model and methods can be applied to any glycogen data set, and could in particular contribute to characterise the mechanisms responsible for glycogen storage disorders.
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Affiliation(s)
- Yvan Rousset
- Institute for Quantitative and Theoretical Biology, Heinrich-Heine University, Düsseldorf, Germany
- Institute for Computational Cell Biology, Heinrich-Heine University, Düsseldorf, Germany
| | - Oliver Ebenhöh
- Institute for Quantitative and Theoretical Biology, Heinrich-Heine University, Düsseldorf, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine University, Düsseldorf, Germany
| | - Adélaïde Raguin
- Institute for Computational Cell Biology, Heinrich-Heine University, Düsseldorf, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine University, Düsseldorf, Germany
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5
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Wang Z, Min X, Hu Z, Sullivan MA, Tang Y, Wang L, Gilbert RG, Shi C, Deng B. The fragility of liver glycogen from humans with type 2 diabetes: A pilot study. Int J Biol Macromol 2022; 221:83-90. [PMID: 36075306 DOI: 10.1016/j.ijbiomac.2022.08.212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/27/2022] [Accepted: 08/31/2022] [Indexed: 11/05/2022]
Abstract
Liver glycogen is a highly branched glucose polymer found as β particles (~20 nm in diameter), which can bind together into larger composite α particles. Hepatic α particles have been shown to be structurally fragile (breaking up into smaller particles in certain solvents) in mouse models of diabetes; if occurring in vivo, the resulting small glycogen particles could exacerbate the poor blood-sugar homeostasis characteristic of the disease. Here we tested if this α-particle fragility also occurred in liver glycogen obtained from humans with diabetes. It was found that liver glycogen from diabetic humans was indeed more fragile than from non-diabetic humans, which was also seen in the mouse experiments we ran in parallel. Proteomic analysis revealed three candidate proteins from differentially expressed glycogen proteins (Diabetes/ Non-diabetes) in both human and mouse groups. Identifying these proteins may give clues to the binding mechanism that holds together α particles together, which, being different in diabetic glycogen, is relevant to diabetes prevention and management.
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Affiliation(s)
- Ziyi Wang
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Xiaobo Min
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Zhenxia Hu
- Department of Pharmacy, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Mitchell A Sullivan
- Glycation and Diabetes, Mater Research Institute - The University of Queensland, Translational Research Institute, Brisbane, QLD 4102, Australia
| | - Yong Tang
- Department of Hepatobiliary Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Liang Wang
- Laboratory Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province 510080, China
| | - Robert G Gilbert
- Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia; Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou 225009, China; Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China
| | - Chen Shi
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
| | - Bin Deng
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
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6
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Kipper K, Mansour A, Pulk A. Neuronal RNA granules are ribosome complexes stalled at the pre-translocation state. J Mol Biol 2022; 434:167801. [PMID: 36038000 DOI: 10.1016/j.jmb.2022.167801] [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: 02/18/2022] [Revised: 06/20/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022]
Abstract
The polarized cell morphology of neurons dictates many neuronal processes, including the axodendridic transport of specific mRNAs and subsequent translation. mRNAs together with ribosomes and RNA-binding proteins form RNA granules that are targeted to axodendrites for localized translation in neurons. It has been established that localized protein synthesis in neurons is essential for long-term memory formation, synaptic plasticity, and neurodegeneration. We have used proteomics and electron microscopy to characterize neuronal RNA granules (nRNAg) isolated from rat brain tissues or human neuroblastoma. We show that ribosome containing RNA granules are morula-like structures when visualized by electron microscopy. Crosslinking-coupled mass-spectrometry identified potential G3BP2 binding site on the ribosome near the eIF3d-binding site on the 40S ribosomal subunit. We used cryo-EM to resolve the structure of the ribosome-component of nRNAg. The cryo-EM reveals that predominant particles in nRNAg are 80S ribosomes, resembling the pre-translocation state where tRNA's are in the hybrid A/P and P/E site. We also describe a new kind of principal motion of the ribosome, which we call the rocking motion.
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Affiliation(s)
- Kalle Kipper
- Structural Biology Unit, Institute of Technology, University of Tartu, Tartu 50411, Estonia
| | - Abbas Mansour
- Structural Biology Unit, Institute of Technology, University of Tartu, Tartu 50411, Estonia
| | - Arto Pulk
- Structural Biology Unit, Institute of Technology, University of Tartu, Tartu 50411, Estonia.
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7
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Wang Z, Hu Z, Deng B, Gilbert RG, Sullivan MA. The effect of high-amylose resistant starch on the glycogen structure of diabetic mice. Int J Biol Macromol 2021; 200:124-131. [PMID: 34968551 DOI: 10.1016/j.ijbiomac.2021.12.071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/24/2021] [Accepted: 12/11/2021] [Indexed: 12/13/2022]
Abstract
Glycogen is a complex branched glucose polymer found in many tissues and acts as a blood-glucose buffer. In the liver, smaller β glycogen particles can bind into larger composite α particles. In mouse models of diabetes, these liver glycogen particles are molecularly fragile, breaking up into smaller particles in the presence of solvents such as dimethyl sulfoxide (DMSO). If this occurs in vivo, such a rapid enzymatic degradation of these smaller particles into glucose could exacerbate the poor blood-glucose control that is characteristic of the disease. High-amylose resistant starch (RS) can escape digestion in the small intestine and ferment in the large intestine, which elicits positive effects on glycemic response and type 2 diabetes. Here we postulate that RS would help attenuate diabetes-related liver glycogen fragility. Normal maize starch and two types of high-amylose starch were fed to diabetic and non-diabetic mice. Molecular size distributions and chain-length distributions of liver glycogen from both groups were characterized to test glycogen fragility before and after DMSO treatment. Consistent with the hypothesis that high blood glucose is associated with glycogen fragility, a high-amylose RS diet prevented the fragility of liver-glycogen α particles. The diets had no significant effect on the glycogen chain-length distributions.
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Affiliation(s)
- Ziyi Wang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou 225009, China; Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China; School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Zhenxia Hu
- Department of Pharmacy, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Bin Deng
- Department of Pharmacy, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Robert G Gilbert
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, College of Agriculture, Yangzhou University, Yangzhou 225009, China; Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou 225009, China; School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Department of Pharmacy, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
| | - Mitchell A Sullivan
- Glycation and Diabetes, Mater Research Institute - The University of Queensland, Translational Research Institute, Brisbane, Qld 4102, Australia.
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8
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Liu QH, Tang JW, Wen PB, Wang MM, Zhang X, Wang L. From Prokaryotes to Eukaryotes: Insights Into the Molecular Structure of Glycogen Particles. Front Mol Biosci 2021; 8:673315. [PMID: 33996916 PMCID: PMC8116748 DOI: 10.3389/fmolb.2021.673315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/07/2021] [Indexed: 12/25/2022] Open
Abstract
Glycogen is a highly-branched polysaccharide that is widely distributed across the three life domains. It has versatile functions in physiological activities such as energy reserve, osmotic regulation, blood glucose homeostasis, and pH maintenance. Recent research also confirms that glycogen plays important roles in longevity and cognition. Intrinsically, glycogen function is determined by its structure that has been intensively studied for many years. The recent association of glycogen α-particle fragility with diabetic conditions further strengthens the importance of glycogen structure in its function. By using improved glycogen extraction procedures and a series of advanced analytical techniques, the fine molecular structure of glycogen particles in human beings and several model organisms such as Escherichia coli, Caenorhabditis elegans, Mus musculus, and Rat rattus have been characterized. However, there are still many unknowns about the assembly mechanisms of glycogen particles, the dynamic changes of glycogen structures, and the composition of glycogen associated proteins (glycogen proteome). In this review, we explored the recent progresses in glycogen studies with a focus on the structure of glycogen particles, which may not only provide insights into glycogen functions, but also facilitate the discovery of novel drug targets for the treatment of diabetes mellitus.
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Affiliation(s)
- Qing-Hua Liu
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau, China.,Faculty of Chinese Medicine, Macau University of Science and Technology, Macau, China
| | - Jia-Wei Tang
- Department of Bioinformatics, School of Medical Informatics and Engineering, Xuzhou Medical University, Xuzhou, China
| | - Peng-Bo Wen
- Department of Bioinformatics, School of Medical Informatics and Engineering, Xuzhou Medical University, Xuzhou, China
| | - Meng-Meng Wang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, China
| | - Xiao Zhang
- Department of Bioinformatics, School of Medical Informatics and Engineering, Xuzhou Medical University, Xuzhou, China
| | - Liang Wang
- Department of Bioinformatics, School of Medical Informatics and Engineering, Xuzhou Medical University, Xuzhou, China.,Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, China
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9
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Optimization of liver glycogen extraction when considering the fine molecular structure. Carbohydr Polym 2021; 261:117887. [PMID: 33766374 DOI: 10.1016/j.carbpol.2021.117887] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/17/2021] [Accepted: 02/28/2021] [Indexed: 12/16/2022]
Abstract
Liver glycogen is a branched glucose polymer that functions as a blood-sugar buffer in animals. Previous studies have shown that glycogen's molecular structure affects its properties. This makes it important to develop a technique that extracts and purifies a representative sample of glycogen. Here we aim to optimize the sucrose density gradient centrifugation method for preserving glycogen's molecular structure by varying the density of the sucrose solution. The preservation of glycogen's structure involves: 1) minimizing molecular damage and 2) obtaining a structurally representative sample of glycogen. The addition of a 10-minute boiling step was also tested as a means for denaturing any glycogen degrading enzymes. Lower sucrose concentrations and the introduction of the boiling step were shown to be beneficial in obtaining a more structurally representative sample, with the preservation of smaller glycogen particles and decreased glycogen chain degradation.
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10
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Wu X, Yin J, Liu J, Gu Y, Wang S, Wang J. Colorimetric detection of glucose based on the binding specificity of a synthetic cyclic peptide. Analyst 2020; 145:7234-7241. [PMID: 32893268 DOI: 10.1039/d0an00211a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel colorimetric sensing method for glucose was developed based on the catalytic activity of Au nanoparticles (NPs) and a synthetic cyclic peptide that specifically binds with glucose. It is the first time that a cyclic peptide was used as a recognition element for glucose sensing. In the absence of glucose, the monolayers of cyclic peptide on the Au NP surfaces interfered little with the adsorption of 4-nitrophenol, and the Au NPs catalyze the reduction of bright yellow 4-nitrophenol to colorless 4-aminophenol in the presence of NaBH4. Added glucose was preferentially bound by the cyclic peptides and impeded the adsorption of 4-nitrophenol. Therefore, the color of the solution presented varying shades of yellow depending on the concentration of glucose. The method had a short response time of 10 min and demonstrated a linear response over a range of glucose concentrations from 0.1 mM to 20 mM, with a lower limit of detection of 0.04 mM. Meanwhile, it also provided results readily observable by the naked eye. The method was successfully applied for the detection of glucose in spiked food samples (Chinese cabbage, pear, and wheat flour) and spiked rabbit blood, and a good recovery rate of 88.04-103.28% and 94.27-101.53% was obtained, respectively.
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Affiliation(s)
- Xuemei Wu
- State Key Laboratory of Food Nutrition and Safety, Tianjin Engineering Research Center of Safety Control Technology in Food Processing, Tianjin University of Science and Technology, Tianjin, 300457, China.
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11
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Dean M. Glycogen in the uterus and fallopian tubes is an important source of glucose during early pregnancy†. Biol Reprod 2020; 101:297-305. [PMID: 31201425 DOI: 10.1093/biolre/ioz102] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 05/16/2019] [Accepted: 06/06/2019] [Indexed: 01/02/2023] Open
Abstract
Pregnancy loss is common during the peri-implantation period in mammals when glucose is required for both embryonic development and decidualization of the endometrium. As the uterus cannot synthesize glucose, all glucose must come directly from maternal circulation as needed or transiently stored as the macromolecule glycogen. Glycogen acts as a glucose reservoir, storing up to 55 000 glucose moieties per molecule. Endometrial glycogen concentrations are correlated with fertility in humans, indicating that glycogen is an essential source of glucose during early pregnancy. In humans and primates, endometrial glycogen concentrations peak during the luteal phase due to progesterone. In contrast, in rats and mink, estradiol triggers an accumulation of uterine glycogen during proestrus and estrus. In mated rats, the glycogen content of the endometrium increases again after implantation due to high levels of glycogen stored in the decidua. In mink, endometrial glycogen reserves are localized in the uterine epithelia at estrus. These reserves are mobilized before implantation, suggesting they are used to support embryonic growth. Uterine glycogen concentrations continue to decrease after implantation in mink, probably due to a lack of decidualization. How ovarian steroids stimulate glycogenesis in the endometrium is unclear, but current evidence suggests that estradiol/progesterone interacts with insulin or insulin-like growth factor signaling. In summary, endometrial glycogen is an essential source of glucose during the peri-implantation period. More work is needed to characterize differences among species, elucidate the fate of the glucose liberated from glycogen, and understand how ovarian steroids regulate glycogen metabolism in the uterus.
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Affiliation(s)
- Matthew Dean
- Department of Animal Science, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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12
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Besford QA, Weiss ACG, Schubert J, Ryan TM, Maitz MF, Tomanin PP, Savioli M, Werner C, Fery A, Caruso F, Cavalieri F. Protein Component of Oyster Glycogen Nanoparticles: An Anchor Point for Functionalization. ACS APPLIED MATERIALS & INTERFACES 2020; 12:38976-38988. [PMID: 32805918 DOI: 10.1021/acsami.0c10699] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Biosourced nanoparticles have a range of desirable properties for therapeutic applications, including biodegradability and low immunogenicity. Glycogen, a natural polysaccharide nanoparticle, has garnered much interest as a component of advanced therapeutic materials. However, functionalizing glycogen for use as a therapeutic material typically involves synthetic approaches that can negatively affect the intrinsic physiological properties of glycogen. Herein, the protein component of glycogen is examined as an anchor point for the photopolymerization of functional poly(N-isopropylacrylamide) (PNIPAM) polymers. Oyster glycogen (OG) nanoparticles partially degrade to smaller spherical particles in the presence of protease enzymes, reflecting a population of surface-bound proteins on the polysaccharide. The grafting of PNIPAM to the native protein component of OG produces OG-PNIPAM nanoparticles of ∼45 nm in diameter and 6.2 MDa in molecular weight. PNIPAM endows the nanoparticles with temperature-responsive aggregation properties that are controllable and reversible and that can be removed by the biodegradation of the protein. The OG-PNIPAM nanoparticles retain the native biodegradability of glycogen. Whole blood incubation assays revealed that the OG-PNIPAM nanoparticles have a low cell association and inflammatory response similar to that of OG. The reported strategy provides functionalized glycogen nanomaterials that retain their inherent biodegradability and low immune cell association.
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Affiliation(s)
- Quinn A Besford
- Leibniz Institute for Polymer Research, Hohe Straße 6, 01069 Dresden, Germany
| | - Alessia C G Weiss
- Leibniz Institute for Polymer Research, Hohe Straße 6, 01069 Dresden, Germany
| | - Jonas Schubert
- Leibniz Institute for Polymer Research, Hohe Straße 6, 01069 Dresden, Germany
| | - Timothy M Ryan
- The Australian Synchrotron, Clayton, Victoria 3168, Australia
| | - Manfred F Maitz
- Leibniz Institute for Polymer Research, Hohe Straße 6, 01069 Dresden, Germany
| | - Pietro Pacchin Tomanin
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Marco Savioli
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Carsten Werner
- Leibniz Institute for Polymer Research, Hohe Straße 6, 01069 Dresden, Germany
| | - Andreas Fery
- Leibniz Institute for Polymer Research, Hohe Straße 6, 01069 Dresden, Germany
| | - Frank Caruso
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Francesca Cavalieri
- School of Science, RMIT University, Melbourne, Victoria 3000, Australia
- Dipartimento di Scienze e Tecnologie Chimiche, Università di Roma "Tor Vergata", Via Della Ricerca Scientifica 1, 00133 Rome, Italy
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13
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Besford QA, Cavalieri F, Caruso F. Glycogen as a Building Block for Advanced Biological Materials. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1904625. [PMID: 31617264 DOI: 10.1002/adma.201904625] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/15/2019] [Indexed: 06/10/2023]
Abstract
Biological nanoparticles found in living systems possess distinct molecular architectures and diverse functions. Glycogen is a unique biological polysaccharide nanoparticle fabricated by nature through a bottom-up approach. The biocatalytic synthesis of glycogen has evolved over time to form a nanometer-sized dendrimer-like structure (20-150 nm) with a highly branched surface and a dense core. This makes glycogen markedly different from other natural linear or branched polysaccharides and particularly attractive as a platform for biomedical applications. Glycogen is inherently biodegradable, nontoxic, and can be functionalized with diverse surface and internal motifs for enhanced biofunctional properties. Recently, there has been growing interest in glycogen as a natural alternative to synthetic polymers and nanoparticles in a range of applications. Herein, the recent literature on glycogen in the material-based sciences, including its use as a constituent in biodegradable hydrogels and fibers, drug delivery vectors, tumor targeting and penetrating nanoparticles, immunomodulators, vaccine adjuvants, and contrast agents, is reviewed. The various methods of chemical functionalization and physical assembly of glycogen nanoparticles into multicomponent nanodevices, which advance glycogen toward a functional therapeutic nanoparticle from nature and back again, are discussed in detail.
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Affiliation(s)
- Quinn A Besford
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Francesca Cavalieri
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
- Dipartimento di Scienze e Tecnologie Chimiche, Università degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - Frank Caruso
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering, The University of Melbourne, Parkville, Victoria, 3010, Australia
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14
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Li C, Hu Z. Is liver glycogen fragility a possible drug target for diabetes? FASEB J 2019; 34:3-15. [PMID: 31914592 DOI: 10.1096/fj.201901463rr] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 10/08/2019] [Accepted: 10/09/2019] [Indexed: 12/14/2022]
Abstract
Liver glycogen α particles are molecularly fragile in diabetic mice, and readily form smaller β particles, which degrade more rapidly to glucose. This effect is well associated with the loss of blood-glucose homeostasis in diabetes. The biological mechanism of such fragility is still unknown; therefore, there are perceived opportunities that could eventually lead to new means to manage type 2 diabetes. The hierarchical structures of glycogen particles are controlled by the underlying biosynthesis/degradation process that involves various enzymes, including, for example, glycogen synthase (GS) and glycogen-branching enzyme (GBE). Recent studies have shown that fragile glycogen α particles in diabetic mice have longer chains and a higher molecular density compared to wild-type mice, indicating an enhanced enzymatic activity ratio of GS to GBE in diabetes. Furthermore, it has been shown that with an improved blood glucose homeostasis, the glycogen fragility in diabetic mice can be restored by treatment with active ingredients from traditional Chinese medicine, yet the underlying mechanism is unknown. In this review, we summarize recent advances in understandings glycogen fragility from the perspectives of glycogen biosynthesis/degradation, glycogen hierarchical structures, and its relation to diabetes. Importantly, we for the first time set GS/GBE activity ratio as the therapeutic target for diabetes.
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Affiliation(s)
- Cheng Li
- Department of Pharmacy, Renmin Hospital of Wuhan University, Wuhan, China.,School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China.,Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Zhenxia Hu
- Department of Pharmacy, Renmin Hospital of Wuhan University, Wuhan, China
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15
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Some molecular structural features of glycogen in the kidneys of diabetic rats. Carbohydr Polym 2019; 229:115526. [PMID: 31826402 DOI: 10.1016/j.carbpol.2019.115526] [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: 08/01/2019] [Revised: 10/09/2019] [Accepted: 10/22/2019] [Indexed: 12/27/2022]
Abstract
Glycogen, a highly-branched glucose polymer, functions as a sugar reservoir in many organs and tissues. Liver glycogen comprises small β particles which can bind to form into large agglomerates (α particles) which readily degrade to β particles in diabetic livers. Muscle glycogen has only β particles, optimal for quick energy release. Healthy kidney contains negligible glycogen, but there is an abnormally high accumulation in diabetic kidneys. We here compare the molecular structure of glycogen in diabetic kidneys with that in liver and muscle, using a diabetic rat model. This involved exploring extraction techniques to minimize glycogen degradation. Using size exclusion chromatography and transmission electron microscopy, it was found that there were only β particles in diabetic kidneys. These are postulated to form during periods of abnormally high blood sugar, the driving force being the need to reduce blood sugar under such circumstances.
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16
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Sullivan MA, Forbes JM. Glucose and glycogen in the diabetic kidney: Heroes or villains? EBioMedicine 2019; 47:590-597. [PMID: 31405756 PMCID: PMC6796499 DOI: 10.1016/j.ebiom.2019.07.067] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/17/2019] [Accepted: 07/29/2019] [Indexed: 12/19/2022] Open
Abstract
Glucose metabolism in the kidney is currently foremost in the minds of nephrologists, diabetologists and researchers globally, as a result of the outstanding success of SGLT2 inhibitors in reducing renal and cardiovascular disease in individuals with diabetes. However, these exciting data have come with the puzzling but fascinating paradigm that many of the beneficial effects on the kidney and cardiovascular system seem to be independent of the systemic glucose lowering actions of these agents. This manuscript places into context an area of research highly relevant to renal glucose metabolism, that of glycogen accumulation and metabolism in the diabetic kidney. Whether the glycogen that abnormally accumulates is pathological (the villain), is somehow protective (the hero) or is inconsequential (the bystander) is a research question that may provide insight into the link between diabetes and diabetic kidney disease.
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Affiliation(s)
- Mitchell A Sullivan
- Glycation and Diabetes Group, Mater Research Institute-The University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia.
| | - Josephine M Forbes
- Glycation and Diabetes Group, Mater Research Institute-The University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia; Mater Clinical School, School of Medicine, The University of Queensland, St Lucia, Queensland, Australia.
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17
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Daniels LJ, Varma U, Annandale M, Chan E, Mellor KM, Delbridge LMD. Myocardial Energy Stress, Autophagy Induction, and Cardiomyocyte Functional Responses. Antioxid Redox Signal 2019; 31:472-486. [PMID: 30417655 DOI: 10.1089/ars.2018.7650] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Significance: Energy stress in the myocardium occurs in a variety of acute and chronic pathophysiological contexts, including ischemia, nutrient deprivation, and diabetic disease settings of substrate disturbance. Although the heart is highly adaptive and flexible in relation to fuel utilization and routes of adenosine-5'-triphosphate (ATP) generation, maladaptations in energy stress situations confer functional deficit. An understanding of the mechanisms that link energy stress to impaired myocardial performance is crucial. Recent Advances: Emerging evidence suggests that, in parallel with regulated enzymatic pathways that control intracellular substrate supply, other processes of "bulk" autophagic macromolecular breakdown may be important in energy stress conditions. Recent findings indicate that cargo-specific autophagic activity may be important in different stress states. In particular, induction of glycophagy, a glycogen-specific autophagy, has been described in acute and chronic energy stress situations. The impact of elevated cardiomyocyte glucose flux relating to glycophagy dysregulation on contractile function is unknown. Critical Issues: Ischemia- and diabetes-related cardiac adverse events comprise the majority of cardiovascular disease morbidity and mortality. Current therapies involve management of systemic comorbidities. Cardiac-specific adjunct treatments targeted to manage myocardial energy stress responses are lacking. Future Directions: New knowledge is required to understand the mechanisms involved in selective recruitment of autophagic responses in the cardiomyocyte energy stress response. In particular, exploration of the links between cell substrate flux, calcium ion (Ca2+) flux, and phagosomal cargo flux is required. Strategies to target specific fuel "bulk" management defects in cardiac energy stress states may be of therapeutic value.
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Affiliation(s)
- Lorna J Daniels
- 1 Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Upasna Varma
- 2 Department of Physiology, University of Melbourne, Melbourne, Australia
| | - Marco Annandale
- 1 Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Eleia Chan
- 2 Department of Physiology, University of Melbourne, Melbourne, Australia
| | - Kimberley M Mellor
- 1 Department of Physiology, University of Auckland, Auckland, New Zealand.,2 Department of Physiology, University of Melbourne, Melbourne, Australia.,3 Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Lea M D Delbridge
- 2 Department of Physiology, University of Melbourne, Melbourne, Australia
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18
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Hu Z, Li E, Sullivan MA, Tan X, Deng B, Gilbert RG, Li C. Glycogen structure in type 1 diabetic mice: Towards understanding the origin of diabetic glycogen molecular fragility. Int J Biol Macromol 2019; 128:665-672. [PMID: 30708007 DOI: 10.1016/j.ijbiomac.2019.01.186] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 12/31/2018] [Accepted: 01/28/2019] [Indexed: 12/28/2022]
Abstract
Glycogen is a complex branched glucose polymer. Liver glycogen in db/db mouse, a type-2 diabetic mouse model, has been found to be more molecularly fragile than in healthy mice. Size-exclusion chromatography was employed in this study to investigate the molecular structure of liver glycogen in two types of type 1 diabetic mouse models (NOD and C57BL/6J mice), sacrificed at various times throughout the diurnal cycle, and the fragility of liver glycogen after exposure to a hydrogen-bond disruptor were tested. Type 1 diabetic mice exhibit a similar glycogen fragility with that observed for db/db mice. This eliminates many of the potential causes for glycogen molecular fragility; the most likely explanation is that it is caused by high blood-glucose level and/or insulin deficiency, both phenotypes being common to both type 1 and type 2 diabetic mice. This result suggests ways towards new drug targets for the management of diabetes.
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Affiliation(s)
- Zhenxia Hu
- Department of Pharmacy, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Enpeng Li
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu Province, China
| | - Mitchell A Sullivan
- Glycation and Diabetes, Translational Research Institute, Mater Research Institute-The University of Queensland, Brisbane, QLD 4102, Australia
| | - Xinle Tan
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Bin Deng
- Department of Pharmacy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Robert G Gilbert
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu Province, China; The University of Queensland, Centre for Nutrition and Food Science, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Cheng Li
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225009, Jiangsu Province, China.
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19
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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.
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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.
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20
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Bezborodkina NN, Chestnova AY, Vorobev ML, Kudryavtsev BN. Spatial Structure of Glycogen Molecules in Cells. BIOCHEMISTRY (MOSCOW) 2018; 83:467-482. [PMID: 29738682 DOI: 10.1134/s0006297918050012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Glycogen is a strongly branched polymer of α-D-glucose, with glucose residues in the linear chains linked by 1→4-bonds (~93% of the total number of bonds) and with branching after every 4-8 residues formed by 1→6-glycosidic bonds (~7% of the total number of bonds). It is thought currently that a fully formed glycogen molecule (β-particle) with the self-glycosylating protein glycogenin in the center has a spherical shape with diameter of ~42 nm and contains ~ 55,000 glucose residues. The glycogen molecule also includes numerous proteins involved in its synthesis and degradation, as well as proteins performing a carcass function. However, the type and force of bonds connecting these proteins to the polysaccharide moiety of glycogen are significantly different. This review presents the available data on the spatial structure of the glycogen molecule and its changes under various physiological and pathological conditions.
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Affiliation(s)
- N N Bezborodkina
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia.
| | - A Yu Chestnova
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia
| | - M L Vorobev
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia
| | - B N Kudryavtsev
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia
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21
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Tan X, Sullivan MA, Nada SS, Deng B, Schulz BL, Gilbert RG. Proteomic Investigation of the Binding Agent between Liver Glycogen β Particles. ACS OMEGA 2018; 3:3640-3645. [PMID: 30023874 PMCID: PMC6045358 DOI: 10.1021/acsomega.8b00119] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 03/22/2018] [Indexed: 06/08/2023]
Abstract
Glycogen is a highly branched glucose polymer which plays an important role in glucose storage and the maintenance of blood sugar homeostasis. The dimeric protein glycogenin can self-glucosylate to act as a primer for glycogen synthesis, eventually resulting in small (∼20 nm diameter) glycogen β particles with a dimer of glycogenin at their core. In the liver, glycogen is also found in the form of α particles: large bound composites of many β particles. Here, we provide evidence using qualitative and quantitative proteomics and size-exclusion chromatography from healthy rat, mouse, and human liver glycogen that glycogenin is the binding agent linking β particles together into α particles.
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Affiliation(s)
- Xinle Tan
- Joint
International Research Laboratory of Agriculture and Agri-Product
Safety, College of Agriculture, Yangzhou
University, Yangzhou 225009, Jiangsu Province, China
- School of Chemistry and Molecular
Biosciences and Centre for Nutrition and Food Sciences,
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
- Tongji
School of Pharmacy and Department of Pharmacy, Union Hospital, Tongji Medical
College, Huazhong University of Science
and Technology, Wuhan, Hubei 430030, China
| | - Mitchell A. Sullivan
- Glycation
and Diabetes, Mater Research Institute, Translational Research Institute, The University of Queensland, Brisbane, Queensland 4102, Australia
| | - Sharif S. Nada
- School of Chemistry and Molecular
Biosciences and Centre for Nutrition and Food Sciences,
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Bin Deng
- Tongji
School of Pharmacy and Department of Pharmacy, Union Hospital, Tongji Medical
College, Huazhong University of Science
and Technology, Wuhan, Hubei 430030, China
| | - Benjamin L. Schulz
- School of Chemistry and Molecular
Biosciences and Centre for Nutrition and Food Sciences,
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Robert G. Gilbert
- Joint
International Research Laboratory of Agriculture and Agri-Product
Safety, College of Agriculture, Yangzhou
University, Yangzhou 225009, Jiangsu Province, China
- School of Chemistry and Molecular
Biosciences and Centre for Nutrition and Food Sciences,
Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Queensland 4072, Australia
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Pathogenesis of Lafora Disease: Transition of Soluble Glycogen to Insoluble Polyglucosan. Int J Mol Sci 2017; 18:ijms18081743. [PMID: 28800070 PMCID: PMC5578133 DOI: 10.3390/ijms18081743] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 08/04/2017] [Accepted: 08/06/2017] [Indexed: 02/07/2023] Open
Abstract
Lafora disease (LD, OMIM #254780) is a rare, recessively inherited neurodegenerative disease with adolescent onset, resulting in progressive myoclonus epilepsy which is fatal usually within ten years of symptom onset. The disease is caused by loss-of-function mutations in either of the two genes EPM2A (laforin) or EPM2B (malin). It characteristically involves the accumulation of insoluble glycogen-derived particles, named Lafora bodies (LBs), which are considered neurotoxic and causative of the disease. The pathogenesis of LD is therefore centred on the question of how insoluble LBs emerge from soluble glycogen. Recent data clearly show that an abnormal glycogen chain length distribution, but neither hyperphosphorylation nor impairment of general autophagy, strictly correlates with glycogen accumulation and the presence of LBs. This review summarizes results obtained with patients, mouse models, and cell lines and consolidates apparent paradoxes in the LD literature. Based on the growing body of evidence, it proposes that LD is predominantly caused by an impairment in chain-length regulation affecting only a small proportion of the cellular glycogen. A better grasp of LD pathogenesis will further develop our understanding of glycogen metabolism and structure. It will also facilitate the development of clinical interventions that appropriately target the underlying cause of LD.
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23
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Technical and experimental features of Magnetic Resonance Spectroscopy of brain glycogen metabolism. Anal Biochem 2017; 529:117-126. [DOI: 10.1016/j.ab.2016.12.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 08/31/2016] [Accepted: 12/23/2016] [Indexed: 01/20/2023]
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24
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Besford QA, Wojnilowicz M, Suma T, Bertleff-Zieschang N, Caruso F, Cavalieri F. Lactosylated Glycogen Nanoparticles for Targeting Prostate Cancer Cells. ACS APPLIED MATERIALS & INTERFACES 2017; 9:16869-16879. [PMID: 28362077 DOI: 10.1021/acsami.7b02676] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Glyconanoparticles that exhibit multivalent binding to lectins are desirable for molecular recognition and therapeutic applications. Herein we explore the use of glycogen nanoparticles as a biosourced glycoscaffold for engineering multivalent glyconanoparticles. Glycogen nanoparticles, a naturally occurring highly branched polymer of glucose, was functionalized with lactose, achieved through copper(I)-catalyzed alkyne-azide cycloaddition chemistry, for targeted interaction with lectins ex situ and on prostate cancer cells. The lactosylated glycogen, which contains terminal β-galactoside moieties, is termed galacto-glycogen (GG), and is found to interact strongly with peanut agglutinin (PNA), a β-galactoside-specific lectin, as observed by optical waveguide lightmode spectroscopy, dynamic light scattering, and quartz crystal microbalance measurements. The GG nanoparticles exhibit multivalent binding to PNA with an affinity constant of 3.4 × 105 M-1, and the GG-PNA complex cannot be displaced by lactose, demonstrating the competitive binding of GG to the lectin. These GG nanoparticles were tested for association with prostate cancer cell membranes in vitro, where the particles exhibited a high affinity for the membrane, as observed from flow cytometry and confocal microscopy. This is inferred to result from specific extracellular galectin-1 targeting. Furthermore, the GG nanoparticles induce aggregation between prostate cancer cells. Our results highlight a strategy for engineering a biosourced polysaccharide with surface moieties that exhibit strong multivalent interactions with lectins, and targeted interaction with prostate cancer cells.
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Affiliation(s)
- Quinn A Besford
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia
| | - Marcin Wojnilowicz
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia
| | - Tomoya Suma
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia
| | - Nadja Bertleff-Zieschang
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia
| | - Frank Caruso
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia
| | - Francesca Cavalieri
- ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical and Biomolecular Engineering, The University of Melbourne , Parkville, Victoria 3010, Australia
- Dipartimento di Scienze e Tecnologie Chimiche, Universita' degli Studi di Roma "Tor Vergata", via della ricerca scientifica 1 , 00173 Rome, Italy
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26
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Liver glycogen in type 2 diabetic mice is randomly branched as enlarged aggregates with blunted glucose release. Glycoconj J 2015; 33:41-51. [PMID: 26521055 DOI: 10.1007/s10719-015-9631-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 12/28/2022]
Abstract
Glycogen is a vital highly branched polymer of glucose that is essential for blood glucose homeostasis. In this article, the structure of liver glycogen from mice is investigated with respect to size distributions, degradation kinetics, and branching structure, complemented by a comparison of normal and diabetic liver glycogen. This is done to screen for differences that may result from disease. Glycogen α-particle (diameter ∼ 150 nm) and β-particle (diameter ∼ 25 nm) size distributions are reported, along with in vitro γ-amylase degradation experiments, and a small angle X-ray scattering analysis of mouse β-particles. Type 2 diabetic liver glycogen upon extraction was found to be present as large loosely bound, aggregates, not present in normal livers. Liver glycogen was found to aggregate in vitro over a period of 20 h, and particle size is shown to be related to rate of glucose release, allowing a structure-function relationship to be inferred for the tissue specific distribution of particle types. Application of branching theories to small angle X-ray scattering data for mouse β-particles revealed these particles to be randomly branched polymers, not fractal polymers. Together, this article shows that type 2 diabetic liver glycogen is present as large aggregates in mice, which may contribute to the inflexibility of interconversion between glucose and glycogen in type 2 diabetes, and further that glycogen particles are randomly branched with a size that is related to the rate of glucose release.
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27
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Chandramouli C, Varma U, Stevens EM, Xiao RP, Stapleton DI, Mellor KM, Delbridge LMD. Myocardial glycogen dynamics: New perspectives on disease mechanisms. Clin Exp Pharmacol Physiol 2015; 42:415-25. [DOI: 10.1111/1440-1681.12370] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 12/29/2014] [Accepted: 01/06/2015] [Indexed: 11/26/2022]
Affiliation(s)
| | - Upasna Varma
- Department of Physiology; University of Melbourne; Melbourne Vic. Australia
| | - Ellie M Stevens
- Department of Physiology; University of Auckland; Auckland New Zealand
| | - Rui-Ping Xiao
- Institute of Molecular Medicine; Peking University; Beijing China
| | - David I Stapleton
- Department of Physiology; University of Melbourne; Melbourne Vic. Australia
- The Florey Institute of Neuroscience; Melbourne Vic. Australia
| | - Kimberley M Mellor
- Department of Physiology; University of Melbourne; Melbourne Vic. Australia
- Department of Physiology; University of Auckland; Auckland New Zealand
| | - Lea MD Delbridge
- Department of Physiology; University of Melbourne; Melbourne Vic. Australia
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28
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Sullivan MA, Li S, Aroney STN, Deng B, Li C, Roura E, Schulz BL, Harcourt BE, Forbes JM, Gilbert RG. A rapid extraction method for glycogen from formalin-fixed liver. Carbohydr Polym 2014; 118:9-15. [PMID: 25542100 DOI: 10.1016/j.carbpol.2014.11.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/17/2014] [Accepted: 11/09/2014] [Indexed: 10/24/2022]
Abstract
Liver glycogen, a highly branched polymer, acts as our blood-glucose buffer. While past structural studies have extracted glycogen from fresh or frozen tissue using a cold-water, sucrose-gradient centrifugation technique, a method for the extraction of glycogen from formalin-fixed liver would allow the analysis of glycogen from human tissues that are routinely collected in pathology laboratories. In this study, both sucrose-gradient and formalin-fixed extraction techniques were carried out on piglet livers, with the yields, purities and size distributions (using size exclusion chromatography) compared. The formalin extraction technique, when combined with a protease treatment, resulted in higher yields (but lower purities) of glycogen with size distributions similar to the sucrose-gradient centrifugation technique. This formalin extraction procedure was also significantly faster, allowing glycogen extraction throughput to increase by an order of magnitude. Both extraction techniques were compatible with mass spectrometry proteomics, with analysis showing the two techniques were highly complementary.
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Affiliation(s)
- Mitchell A Sullivan
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Shihan Li
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Samuel T N Aroney
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Bin Deng
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
| | - Cheng Li
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Eugeni Roura
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Benjamin L Schulz
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Brooke E Harcourt
- Glycation and Diabetes Complications, Mater Research-UQ, Translational Research Institute, Woolloongabba, QLD 4102, Australia.
| | - Josephine M Forbes
- Glycation and Diabetes Complications, Mater Research-UQ, Translational Research Institute, Woolloongabba, QLD 4102, Australia; Mater Clinical School, University of Queensland, Brisbane, QLD 4072, Australia.
| | - Robert G Gilbert
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
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Bolinger MT, Rodnick KJ. Differential effects of temperature and glucose on glycogenolytic enzymes in tissues of rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol B Biochem Mol Biol 2014; 171:26-33. [PMID: 24704523 DOI: 10.1016/j.cbpb.2014.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 03/10/2014] [Accepted: 03/27/2014] [Indexed: 11/26/2022]
Abstract
The pathways and regulatory mechanisms of glycogenolysis remain relatively unexplored in non-mammalian vertebrates, especially poikilotherms. We studied the temperature sensitivity and inhibition of glycogenolytic enzymes in liver, ventricle, and white muscle of rainbow trout acclimated to 14 °C. Glycogen phosphorylase (GP) and acid α-glucosidase (GAA) activities were measured in homogenates of tissues at physiological temperatures (4, 14, and 24 °C), and in the presence of allosteric inhibitor, glucose. Higher GP versus GAA activity in all three tissues suggested a predominance of phosphorolytic glycogenolysis over the lysosomal glucosidic pathway. GP activities at 14 °C were ~2-fold higher in the ventricle and white muscle versus the liver and selectively increased by AMP in striated muscle. Conversely, the activities of GAA and lysosomal marker acid phosphatase were 8- to 10-fold higher in the liver compared with the ventricle and white muscle. Thermal sensitivity (Q10) was increased for GP in all tissues below 14 °C and decreased in striated muscle in the absence of AMP above 14 °C. GAA had lower Q10 values than GP below 14 °C, and, unlike GP, Q10s for GAA were not different between tissues or affected by temperature. Both GP (in the absence of AMP) and GAA were inhibited by glucose in a dose-dependent manner, with the lowest IC50 values observed in the white muscle (1.4 and 6.3 mM, respectively). In conclusion, despite comparatively low kinetic potential, lysosomal GAA might facilitate glycogenolysis at colder body temperatures in striated muscle and intracellular glucose could limit phosphorolytic and glucosidic glycogenolysis in multiple tissues of the rainbow trout.
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Affiliation(s)
- Mark T Bolinger
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209-8007, USA
| | - Kenneth J Rodnick
- Department of Biological Sciences, Idaho State University, Pocatello, ID 83209-8007, USA.
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Sullivan MA, Powell PO, Witt T, Vilaplana F, Roura E, Gilbert RG. Improving size-exclusion chromatography separation for glycogen. J Chromatogr A 2014; 1332:21-9. [PMID: 24508396 DOI: 10.1016/j.chroma.2014.01.053] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 12/23/2013] [Accepted: 01/20/2014] [Indexed: 10/25/2022]
Abstract
Glycogen is a hyperbranched glucose polymer comprised of glycogen β particles, which can also form much larger composite α particles. The recent discovery using size-exclusion chromatography (SEC) that fewer, smaller, α particles are found in diabetic-mouse liver compared to healthy mice highlights the need to achieve greater accuracy in the size separation methods used to analyze α and β particles. While past studies have used dimethyl sulfoxide as the SEC eluent to analyze the molecular size and structure of native glycogen, an aqueous eluent has not been rigorously tested and compared with dimethyl sulfoxide. The conditions for SEC of pig-liver glycogen, phytoglycogen and oyster glycogen were optimized by comparing two different eluents, aqueous 50 mM NH₄NO₃/0.02% NaN₃ and dimethyl sulfoxide/0.5% LiBr, run through different column materials and pore sizes at various flow rates. The aqueous system gave distinct size separation of α- and β-particle peaks, allowing for a more detailed and quantitative analysis and comparison between liver glycogen samples. This greater resolution has also revealed key differences between the structure of liver glycogen and phytoglycogen.
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Affiliation(s)
- Mitchell A Sullivan
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia
| | - Prudence O Powell
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia
| | - Torsten Witt
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia
| | - Francisco Vilaplana
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia; Division of Glycoscience, School of Biotechnology and Wallenberg Wood Science Centre (WWSC), KTH Royal Institute of Technology, AlbaNova University Centre, SE-106 91 Stockholm, Sweden
| | - Eugeni Roura
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia
| | - Robert G Gilbert
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, Queensland 4072, Australia.
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Sullivan MA, Aroney STN, Li S, Warren FJ, Joo JS, Mak KS, Stapleton DI, Bell-Anderson KS, Gilbert RG. Changes in glycogen structure over feeding cycle sheds new light on blood-glucose control. Biomacromolecules 2014; 15:660-5. [PMID: 24372590 DOI: 10.1021/bm401714v] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Liver glycogen, a highly branched polymer of glucose, is important for maintaining blood-glucose homeostasis. It was recently shown that db/db mice, a model for Type 2 diabetes, are unable to form the large composite glycogen α particles present in normal, healthy mice. In this study, the structure of healthy mouse-liver glycogen over the diurnal cycle was characterized using size exclusion chromatography and transmission electron microscopy. Glycogen was found to be formed as smaller β particles, and then only assembled into large α particles, with a broad size distribution, significantly after the time when glycogen content had reached a maximum. This pathway, missing in diabetic animals, is likely to give optimal blood-glucose control during the daily feeding cycle. Lack of this control may contribute to, or result from, diabetes. This discovery suggests novel approaches to diabetes management.
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Affiliation(s)
- Mitchell A Sullivan
- Tongji School of Pharmacy, Huazhong University of Science and Technology , Wuhan, Hubei 430030, China
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Gilbert RG, Sullivan MA. The Molecular Size Distribution of Glycogen and its Relevance to Diabetes. Aust J Chem 2014. [DOI: 10.1071/ch13573] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Glycogen is a highly branched polymer of glucose, functioning as a blood-glucose buffer. It comprises relatively small β-particles, which may be joined as larger aggregate α-particles. The size distributions from size-exclusion chromatography (SEC, also known as GPC) of liver glycogen from non-diabetic and diabetic mice show that diabetic mice have impaired α-particle formation, shedding new light on diabetes. SEC data also suggest the type of bonding holding β-particles together in α-particles. SEC characterisation of liver glycogen at various time points in a day/night cycle indicates that liver glycogen is initially synthesised as β-particles, and then joined by an unknown process to form α-particles. These α-particles are more resistant to degradation, presumably because of their lower surface area-to-volume ratio. These findings have important implications for new drug targets for diabetes management.
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Powell PO, Sullivan MA, Sweedman MC, Stapleton DI, Hasjim J, Gilbert RG. Extraction, isolation and characterisation of phytoglycogen from su-1 maize leaves and grain. Carbohydr Polym 2014; 101:423-31. [DOI: 10.1016/j.carbpol.2013.09.061] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 08/13/2013] [Accepted: 09/18/2013] [Indexed: 10/26/2022]
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Myocardial glycophagy - a specific glycogen handling response to metabolic stress is accentuated in the female heart. J Mol Cell Cardiol 2013; 65:67-75. [PMID: 24080183 DOI: 10.1016/j.yjmcc.2013.09.014] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Revised: 09/19/2013] [Accepted: 09/21/2013] [Indexed: 01/03/2023]
Abstract
Cardiac metabolic stress is a hallmark of many cardiac pathologies, including diabetes. Cardiac glycogen mis-handling is a frequent manifestation of various cardiopathologies. Diabetic females have a higher risk of heart disease than males, yet sex disparities in cardiac metabolic stress settings are not well understood. Oestrogen acts on key glycogen regulatory proteins. The goal of this study was to evaluate sex-specific metabolic stress-triggered cardiac glycogen handling responses. Male and female adult C57Bl/6J mice were fasted for 48h. Cardiac glycogen content, particle size, regulatory enzymes, signalling intermediates and autophagic processes were evaluated. Female hearts exhibited 51% lower basal glycogen content than males associated with lower AMP-activated-kinase (AMPK) activity (35% decrease in pAMPK:AMPK). With fasting, glycogen accumulated in female hearts linked with decreased particle size and upregulation of Akt and AMPK signalling, activation of glycogen synthase and inactivation of glycogen phosphorylase. Fasting did not alter glycogen content or regulatory proteins in male hearts. Expression of glycogen autophagy marker, starch-binding-protein-domain-1 (STBD1), was 63% lower in female hearts than males and increased by 69% with fasting in females only. Macro-autophagy markers, p62 and LC3BII:I ratio, increased with fasting in male and female hearts. This study identifies glycogen autophagy ('glycophagy') as a potentially important component of the response to cardiac metabolic stress. Glycogen autophagy occurs in association with a marked and selective accumulation of glycogen in the female myocardium. Our findings suggest that sex-specific differences in glycogen handling may have cardiopathologic consequences in various settings, including diabetic cardiomyopathy.
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Gilbert RG, Wu AC, Sullivan MA, Sumarriva GE, Ersch N, Hasjim J. Improving human health through understanding the complex structure of glucose polymers. Anal Bioanal Chem 2013; 405:8969-80. [DOI: 10.1007/s00216-013-7129-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Revised: 06/01/2013] [Accepted: 06/06/2013] [Indexed: 10/26/2022]
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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.
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Affiliation(s)
- David Stapleton
- University of Utah School of Medicine, Rm 4C464B SOM, 30 N 1900 E, Salt Lake City, Utah 84132, USA.
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Sullivan MA, O'Connor MJ, Umana F, Roura E, Jack K, Stapleton DI, Gilbert RG. Molecular insights into glycogen α-particle formation. Biomacromolecules 2012; 13:3805-13. [PMID: 23004915 DOI: 10.1021/bm3012727] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glycogen, a hyperbranched complex glucose polymer, is an intracellular glucose store that provides energy for cellular functions, with liver glycogen involved in blood-glucose regulation. Liver glycogen comprises complex α particles made up of smaller β particles. The recent discovery that these α particles are smaller and fewer in diabetic, compared with healthy, mice highlights the need to elucidate the nature of α-particle formation; this paper tests various possibilities for binding within α particles. Acid hydrolysis effects, examined using dynamic light scattering and size exclusion chromatography, showed that the binding is not simple α-(1→4) or α-(1→6) glycosidic linkages. There was no significant change in α particle size after the addition of various reagents, which disrupt disulfide, protein, and hydrogen bonds and hydrophobic interactions. The results are consistent with proteinaceous binding between β particles in α particles, with the inability of protease to break apart particles being attributed to steric hindrance.
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Affiliation(s)
- Mitchell A Sullivan
- Centre for Nutrition & Food Sciences (Building 83/S434), Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, Qld 4072, Australia
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