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Zhang X, Duan X, Liu X. The role of kinases in peripheral nerve regeneration: mechanisms and implications. Front Neurol 2024; 15:1340845. [PMID: 38689881 PMCID: PMC11058862 DOI: 10.3389/fneur.2024.1340845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 04/02/2024] [Indexed: 05/02/2024] Open
Abstract
Peripheral nerve injury disease is a prevalent traumatic condition in current medical practice. Despite the present treatment approaches, encompassing surgical sutures, autologous nerve or allograft nerve transplantation, tissue engineering techniques, and others, an effective clinical treatment method still needs to be discovered. Exploring novel treatment methods to improve peripheral nerve regeneration requires more effort in investigating the cellular and molecular mechanisms involved. Many factors are associated with the regeneration of injured peripheral nerves, including the cross-sectional area of the injured nerve, the length of the nerve gap defect, and various cellular and molecular factors such as Schwann cells, inflammation factors, kinases, and growth factors. As crucial mediators of cellular communication, kinases exert regulatory control over numerous signaling cascades, thereby participating in various vital biological processes, including peripheral nerve regeneration after nerve injury. In this review, we examined diverse kinase classifications, distinct nerve injury types, and the intricate mechanisms involved in peripheral nerve regeneration. Then we stressed the significance of kinases in regulating autophagy, inflammatory response, apoptosis, cell cycle, oxidative processes, and other aspects in establishing conductive microenvironments for nerve tissue regeneration. Finally, we briefly discussed the functional roles of kinases in different types of cells involved in peripheral nerve regeneration.
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Affiliation(s)
- Xu Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, School of Life Science, Nantong Laboratory of Development and Diseases, Medical College, Clinical Medical Research Center, Affiliated Wuxi Clinical College of Nantong University, Nantong University, Nantong, China
- Clinical Medical Research Center, Wuxi No. 2 People's Hospital, Jiangnan University Medical Center, Wuxi, China
| | - Xuchu Duan
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, School of Life Science, Nantong Laboratory of Development and Diseases, Medical College, Clinical Medical Research Center, Affiliated Wuxi Clinical College of Nantong University, Nantong University, Nantong, China
| | - Xiaoyu Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, School of Life Science, Nantong Laboratory of Development and Diseases, Medical College, Clinical Medical Research Center, Affiliated Wuxi Clinical College of Nantong University, Nantong University, Nantong, China
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Cai Y, Liu S, Zeng F, Rao Z, Yan C, Xing Q, Chen Y. Exploring the protective effect of Sangggua Drink against type 2 diabetes mellitus in db/db mice using a network pharmacological approach and experimental validation. Heliyon 2023; 9:e18026. [PMID: 37483759 PMCID: PMC10362244 DOI: 10.1016/j.heliyon.2023.e18026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 06/28/2023] [Accepted: 07/05/2023] [Indexed: 07/25/2023] Open
Abstract
Sanggua Drink (SGD) is an experienced formula for clinical treatment of type 2 diabetes mellitus (T2DM). Network pharmacology and experiments were combined to explore the potential mechanism of action of SGD on T2DM. The material basis and action mechanism of SGD were investigated to reveal the active components of SGD, potential target prediction was conducted from TargetNet, PharmMapper; Cytoscape was used to construct PPI network and component-target-pathway (C-T-P) network diagram to interpret biological processes and enrich action pathways. 54 compounds and 41 key target proteins were screened, and a total of 98 signaling pathways were obtained. In vivo experiments, the levels of p-AMPK (P < 0.01), p-ACC and p-AKT were significantly increased in the mice with SGD intervention compared to the db/db mice, while level of FOXO1 were decreased. The results suggested that SGD might improve insulin resistance and glucose metabolism in T2DM mice by activating the AMPK/Akt signaling pathway.
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Affiliation(s)
- Yu Cai
- Hubei Provincial Research Center for TCM Health Food Engineering, School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, China
| | - Simin Liu
- Hubei Provincial Research Center for TCM Health Food Engineering, School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, China
| | - Fei Zeng
- Hubei Provincial Research Center for TCM Health Food Engineering, School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, China
| | - Zhiwei Rao
- Central Hospital of Xianning, The First Affiliate Hospital of Hubei University of Science, China
| | - Chunchao Yan
- Hubei Provincial Research Center for TCM Health Food Engineering, School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, China
| | - Qichang Xing
- Hubei Provincial Research Center for TCM Health Food Engineering, School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, China
| | - Yunzhong Chen
- Hubei Provincial Research Center for TCM Health Food Engineering, School of Pharmacy, Hubei University of Chinese Medicine, Wuhan, 430065, China
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Learning Ability and Hippocampal Transcriptome Responses to Early and Later Life Environmental Complexities in Dual-Purpose Chicks. Animals (Basel) 2022; 12:ani12050668. [PMID: 35268235 PMCID: PMC8909157 DOI: 10.3390/ani12050668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/28/2022] [Accepted: 03/04/2022] [Indexed: 11/17/2022] Open
Abstract
In this study, we hypothesized that complex early-life environments enhance the learning ability and the hippocampal plasticity when the individual is faced with future life challenges. Chicks were divided into a barren environment group (BG), a litter materials group (LG), and a perches and litter materials group (PLG) until 31 days of age, and then their learning abilities were tested following further rearing in barren environments for 22 days. In response to the future life challenge, the learning ability showed no differences among the three groups. In the hippocampal KEGG pathways, the LG chicks showed the downregulation of neural-related genes neuronal growth regulator 1 (NEGR1) and neurexins (NRXN1) in the cell adhesion molecules pathway compared to the BG (p < 0.05). Immune-related genes TLR2 in Malaria and Legionellosis and IL-18 and IL18R1 in the TNF signaling pathway were upregulated in the LG compared to in the BG (p < 0.05). Compared to the BG, the PLG displayed upregulated TLR2A in Malaria (p < 0.05). The PLG showed upregulated neural-related gene, i.e., neuronal acetylcholine receptor subunit alpha-7-like (CHRNA8) in the nicotine addiction pathway and secretagogin (SCGN) gene expression, as compared to the LG (p < 0.05). In conclusion, early-life environmental complexities had limited effects on the learning ability in response to a future life challenge. Early-life perches and litter materials can improve neural- and immune-related gene expression and functional pathways in the hippocampus of chicks.
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Investigation of phytoconstituents of Enicostemma littorale as potential glucokinase activators through molecular docking for the treatment of type 2 diabetes mellitus. In Silico Pharmacol 2021; 10:1. [PMID: 34926125 DOI: 10.1007/s40203-021-00116-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 11/25/2021] [Indexed: 11/27/2022] Open
Abstract
Glucokinase (GK) is an enzyme involved in synthesising glucose into glucose-6 phosphate and serves a crucial function in glucose sensing. Therefore, agents that induce GK activation could be used to treat T2DM. The present work has been carried out to investigate the GK activation potential of phytoconstituents of Enicostemma littorale through molecular docking. All the phytoconstituents have been screened through the Lipinski rule of 5, Veber's rule, and ADMET properties. From these initial screening, only Apigenin, Ferulic acid, Genkwanin, p-coumaric acid, Protocatechuic acid, Syringic acid, and Vanillic acid have been selected to perform molecular docking studies. The binding free energy and binding mode of the native ligand in the allosteric site of the enzyme have been considered the reference for the other molecules' validation. The native ligand has exhibited - 7.2 kcal/mol binding free energy, whereas; it has formed four hydrogen bonds with THR-228, LYS-169, ASP-78, and GLY-81. Based on these findings, the interactions of phytoconstituents have been justified. Apigenin, genkwanin, and swertiamarin exhibited - 8.7, - 7.5, and - 8.3 kcal/mol binding free energy, respectively, which indicates better enzyme activation than the native ligand. Swertiamarin has formed 08 hydrogen bonds with allosteric amino acid residues, which confirms the excellent enzyme activation by these phytoconstituents. We concluded that if we can isolate and consume the exact active phytoconstituents (GK activators) from this plant, we can use them effectively to treat T2DM. More GK activators can be developed by considering them as a natural lead moiety.
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Perreault L, Skyler JS, Rosenstock J. Novel therapies with precision mechanisms for type 2 diabetes mellitus. Nat Rev Endocrinol 2021; 17:364-377. [PMID: 33948015 DOI: 10.1038/s41574-021-00489-y] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/23/2021] [Indexed: 02/06/2023]
Abstract
Type 2 diabetes mellitus (T2DM) is one of the greatest health crises of our time and its prevalence is projected to increase by >50% globally by 2045. Currently, 10 classes of drugs are approved by the US Food and Drug Administration for the treatment of T2DM. Drugs in development for T2DM must show meaningful reductions in glycaemic parameters as well as cardiovascular safety. Results from an increasing number of cardiovascular outcome trials using modern T2DM therapeutics have shown a reduced risk of atherosclerotic cardiovascular disease, congestive heart failure and chronic kidney disease. Hence, guidelines have become increasingly evidence based and more patient centred, focusing on reaching individualized glycaemic goals while optimizing safety, non-glycaemic benefits and the prevention of complications. The bar has been raised for novel therapies under development for T2DM as they are now expected to achieve these aims and possibly even treat concurrent comorbidities. Indeed, the pharmaceutical pipeline for T2DM is fertile. Drugs that augment insulin sensitivity, stimulate insulin secretion or the incretin axis, or suppress hepatic glucose production are active in more than 7,000 global trials using new mechanisms of action. Our collective goal of being able to truly personalize medicine for T2DM has never been closer at hand.
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Affiliation(s)
- Leigh Perreault
- University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| | - Jay S Skyler
- Diabetes Research Institute, University of Miami, Miami, FL, USA
| | - Julio Rosenstock
- Dallas Diabetes Research Center at Medical City, Dallas, TX, USA
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Galcheva S, Demirbilek H, Al-Khawaga S, Hussain K. The Genetic and Molecular Mechanisms of Congenital Hyperinsulinism. Front Endocrinol (Lausanne) 2019; 10:111. [PMID: 30873120 PMCID: PMC6401612 DOI: 10.3389/fendo.2019.00111] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 02/06/2019] [Indexed: 12/13/2022] Open
Abstract
Congenital hyperinsulinism (CHI) is a heterogenous and complex disorder in which the unregulated insulin secretion from pancreatic beta-cells leads to hyperinsulinaemic hypoglycaemia. The severity of hypoglycaemia varies depending on the underlying molecular mechanism and genetic defects. The genetic and molecular causes of CHI include defects in pivotal pathways regulating the secretion of insulin from the beta-cell. Broadly these genetic defects leading to unregulated insulin secretion can be grouped into four main categories. The first group consists of defects in the pancreatic KATP channel genes (ABCC8 and KCNJ11). The second and third categories of conditions are enzymatic defects (such as GDH, GCK, HADH) and defects in transcription factors (for example HNF1α, HNF4α) leading to changes in nutrient flux into metabolic pathways which converge on insulin secretion. Lastly, a large number of genetic syndromes are now linked to hyperinsulinaemic hypoglycaemia. As the molecular and genetic basis of CHI has expanded over the last few years, this review aims to provide an up-to-date knowledge on the genetic causes of CHI.
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Affiliation(s)
- Sonya Galcheva
- Department of Paediatrics, University Hospital St. Marina, Varna Medical University, Varna, Bulgaria
| | - Hüseyin Demirbilek
- Department of Paediatric Endocrinology, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Sara Al-Khawaga
- Division of Endocrinology, Department of Paediatric Medicine, Sidra Medicine, Doha, Qatar
| | - Khalid Hussain
- Division of Endocrinology, Department of Paediatric Medicine, Sidra Medicine, Doha, Qatar
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Zhu XX, Zhu DL, Li XY, Li YL, Jin XW, Hu TX, Zhao Y, Li YG, Zhao GY, Ren S, Zhang Y, Ding YH, Chen L. Dorzagliatin (HMS5552), a novel dual-acting glucokinase activator, improves glycaemic control and pancreatic β-cell function in patients with type 2 diabetes: A 28-day treatment study using biomarker-guided patient selection. Diabetes Obes Metab 2018; 20:2113-2120. [PMID: 29707866 DOI: 10.1111/dom.13338] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/19/2018] [Accepted: 04/24/2018] [Indexed: 01/04/2023]
Abstract
AIMS To investigate the pharmacokinetics and pharmacodynamics of a dual-acting glucokinase activator, dorzagliatin, and its safety, tolerability and effect on pancreatic β-cell function in Chinese patients with type 2 diabetes (T2D). MATERIALS AND METHODS A total of 24 T2D patients were selected, utilizing a set of predefined clinical biomarkers, and were randomized to receive dorzagliatin 75 mg twice or once daily (BID, QD respectively) for 28 days. Changes in HbA1c and glycaemic parameters from baseline to Day 28 were assessed. In addition, changes in β-cell function from baseline to Day 32 were evaluated. RESULTS Significant reductions in HbA1c were observed in both regimens on Day 28 (-0.79%, 75 mg BID; -1.22%, 75 mg QD). Similar trends were found in the following parameters, including reductions from baseline in fasting plasma glucose by 1.20 mmol/L and 1.51 mmol/L, in 2-hour postprandial glucose by 2.48 mmol/L and 5.03 mmol/L, and in glucose AUC0-24 by 18.59% and 20.98%, for the BID and QD groups, respectively. Both regimens resulted in improvement in β-cell function as measured by steady state HOMA 2 parameter, %B, which increased by 36.31% and 40.59%, and by dynamic state parameter, ΔC30 /ΔG30 , which increased by 24.66% and 167.67%, for the BID and QD groups, respectively. Dorzagliatin was well tolerated in both regimens, with good pharmacokinetic profiles. CONCLUSIONS Dorzagliatin treatment for 28 days in Chinese T2D patients, selected according to predefined biomarkers, resulted in significant improvement in β-cell function and glycaemic control. The safety and pharmacokinetic profile of dorzagliatin supports a subsequent Phase II trial design and continued clinical development.
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Affiliation(s)
- Xiao-Xue Zhu
- Phase I Clinical Trial Unit, The First Hospital of Jilin University, Changchun, China
| | - Da-Long Zhu
- Department of Endocrinology and Metabolism, Nanjing Drum Hospital, Nanjing University Medical School, Nanjing, China
| | - Xiao-Ying Li
- Department of Endocrinology and Metabolism, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Ya-Lin Li
- Hua Medicine (Shanghai) Limited, Shanghai, China
| | - Xiao-Wei Jin
- Hua Medicine (Shanghai) Limited, Shanghai, China
| | - Tian-Xin Hu
- Hua Medicine (Shanghai) Limited, Shanghai, China
| | - Yu Zhao
- Hua Medicine (Shanghai) Limited, Shanghai, China
| | - Yong-Guo Li
- Hua Medicine (Shanghai) Limited, Shanghai, China
| | - Gui-Yu Zhao
- Hua Medicine (Shanghai) Limited, Shanghai, China
| | - Shuang Ren
- Hua Medicine (Shanghai) Limited, Shanghai, China
| | - Yi Zhang
- Hua Medicine (Shanghai) Limited, Shanghai, China
| | - Yan-Hua Ding
- Phase I Clinical Trial Unit, The First Hospital of Jilin University, Changchun, China
| | - Li Chen
- Hua Medicine (Shanghai) Limited, Shanghai, China
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Seckinger KM, Rao VP, Snell NE, Mancini AE, Markwardt ML, Rizzo MA. Nitric Oxide Activates β-Cell Glucokinase by Promoting Formation of the "Glucose-Activated" State. Biochemistry 2018; 57:5136-5144. [PMID: 30053375 PMCID: PMC6338087 DOI: 10.1021/acs.biochem.8b00333] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The release of insulin from the pancreas is tightly controlled by glucokinase (GCK) activity that couples β-cell metabolism to changes in blood sugar. Despite having only a single glucose-binding site, GCK displays positive glucose cooperativity. Ex vivo structural studies have identified several potential protein conformations with varying levels of enzymatic activity, yet it is unclear how living cells regulate GCK cooperativity. To better understand the cellular regulation of GCK activation, we developed a homotransfer Förster resonance energy transfer (FRET) GCK biosensor and used polarization microscopy to eliminate fluorescence crosstalk from FRET quantification and improve the signal-to-noise ratio. This approach enhanced sensor contrast compared to that seen with the heterotransfer FRET GCK reporter and allowed observation of individual GCK states using an automated method to analyze FRET data at the pixel level. Mutations known to activate and inhibit GCK activity produced distinct anisotropy distributions, suggesting that at least two conformational states exist in living cells. A high glucose level activated the biosensor in a manner consistent with GCK's enzymology. Interestingly, glucose-free conditions did not affect GCK biosensor FRET, indicating that there is a single low-activity state, which is counter to proposed structural models of GCK cooperativity. Under low-glucose conditions, application of chemical NO donors efficiently shifted GCK to the more active conformation. Notably, GCK activation by mutation, a high glucose level, a pharmacological GCK activator, or S-nitrosylation all shared the same FRET distribution. These data suggest a simplified model for GCK activation in living cells, where post-translational modification of GCK by S-nitrosylation facilitates a single conformational transition that enhances GCK enzymatic activity.
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Affiliation(s)
- Kendra M. Seckinger
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Vishnu P. Rao
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Nicole E. Snell
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Allison E. Mancini
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Michele L. Markwardt
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - M. A. Rizzo
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
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Adam J, Ramracheya R, Chibalina MV, Ternette N, Hamilton A, Tarasov AI, Zhang Q, Rebelato E, Rorsman NJG, Martín-Del-Río R, Lewis A, Özkan G, Do HW, Spégel P, Saitoh K, Kato K, Igarashi K, Kessler BM, Pugh CW, Tamarit-Rodriguez J, Mulder H, Clark A, Frizzell N, Soga T, Ashcroft FM, Silver A, Pollard PJ, Rorsman P. Fumarate Hydratase Deletion in Pancreatic β Cells Leads to Progressive Diabetes. Cell Rep 2018; 20:3135-3148. [PMID: 28954230 PMCID: PMC5637167 DOI: 10.1016/j.celrep.2017.08.093] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 07/27/2017] [Accepted: 08/29/2017] [Indexed: 12/31/2022] Open
Abstract
We explored the role of the Krebs cycle enzyme fumarate hydratase (FH) in glucose-stimulated insulin secretion (GSIS). Mice lacking Fh1 in pancreatic β cells (Fh1βKO mice) appear normal for 6–8 weeks but then develop progressive glucose intolerance and diabetes. Glucose tolerance is rescued by expression of mitochondrial or cytosolic FH but not by deletion of Hif1α or Nrf2. Progressive hyperglycemia in Fh1βKO mice led to dysregulated metabolism in β cells, a decrease in glucose-induced ATP production, electrical activity, cytoplasmic [Ca2+]i elevation, and GSIS. Fh1 loss resulted in elevated intracellular fumarate, promoting succination of critical cysteines in GAPDH, GMPR, and PARK 7/DJ-1 and cytoplasmic acidification. Intracellular fumarate levels were increased in islets exposed to high glucose and in islets from human donors with type 2 diabetes (T2D). The impaired GSIS in islets from diabetic Fh1βKO mice was ameliorated after culture under normoglycemic conditions. These studies highlight the role of FH and dysregulated mitochondrial metabolism in T2D. Fh1 loss in β cells causes progressive Hif1α-independent diabetes Fh1 loss in β cells impairs ATP generation, electrical activity, and GSIS Elevated fumarate is a feature of diabetic murine and human islets “Normoglycemia” restores GSIS in Fh1βKO islets
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Affiliation(s)
- Julie Adam
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK; Nuffield Department of Medicine, Henry Wellcome Building for Molecular Physiology, University of Oxford, Oxford OX3 7BN, UK; Nuffield Department of Medicine, NDMRB, University of Oxford, Oxford OX3 7FZ, UK.
| | - Reshma Ramracheya
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK
| | - Margarita V Chibalina
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK
| | - Nicola Ternette
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK
| | - Alexander Hamilton
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK
| | - Andrei I Tarasov
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK
| | - Quan Zhang
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK
| | - Eduardo Rebelato
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK; Department of Biophysics, Federal University of Sao Paulo, Sao Paulo 04023-062, Brazil
| | - Nils J G Rorsman
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK
| | - Rafael Martín-Del-Río
- Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Ramón y Cajal Hospital, Madrid, Spain
| | - Amy Lewis
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - Gizem Özkan
- Nuffield Department of Medicine, Henry Wellcome Building for Molecular Physiology, University of Oxford, Oxford OX3 7BN, UK
| | - Hyun Woong Do
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK
| | - Peter Spégel
- Centre for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, 221 00 Lund, Sweden
| | - Kaori Saitoh
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Tsuruoka, Yamagata 997-0052, Japan
| | - Keiko Kato
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Tsuruoka, Yamagata 997-0052, Japan
| | - Kaori Igarashi
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Tsuruoka, Yamagata 997-0052, Japan
| | - Benedikt M Kessler
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7FZ, UK
| | - Christopher W Pugh
- Nuffield Department of Medicine, Henry Wellcome Building for Molecular Physiology, University of Oxford, Oxford OX3 7BN, UK; Nuffield Department of Medicine, NDMRB, University of Oxford, Oxford OX3 7FZ, UK
| | - Jorge Tamarit-Rodriguez
- Biochemistry Department, School of Medicine, Complutense University of Madrid, 28040 Madrid, Spain
| | - Hindrik Mulder
- Lund University Diabetes Centre, Unit of Molecular Metabolism, Clinical Research Centre, Malmo University Hospital, 20502 Malmo, Sweden
| | - Anne Clark
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK
| | - Norma Frizzell
- Department of Pharmacology, Physiology & Neuroscience, School of Medicine, University of South Carolina, Columbia, SC 29208, USA
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, 246-2 Mizukami, Tsuruoka, Yamagata 997-0052, Japan
| | - Frances M Ashcroft
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Andrew Silver
- Centre for Genomics and Child Health, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - Patrick J Pollard
- Nuffield Department of Medicine, Henry Wellcome Building for Molecular Physiology, University of Oxford, Oxford OX3 7BN, UK; Department of Physiology, Institute of Neuroscience and Physiology, University of Göteborg, 405 30 Göteborg, Sweden
| | - Patrik Rorsman
- Radcliffe Department of Medicine, OCDEM, Churchill Hospital, University of Oxford, Oxford OX3 7LE, UK; Department of Physiology, Institute of Neuroscience and Physiology, University of Göteborg, 405 30 Göteborg, Sweden.
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10
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Doliba NM, Liu Q, Li C, Chen P, Liu C, Naji A, Matschinsky FM. Inhibition of cholinergic potentiation of insulin secretion from pancreatic islets by chronic elevation of glucose and fatty acids: Protection by casein kinase 2 inhibitor. Mol Metab 2017; 6:1240-1253. [PMID: 29031723 PMCID: PMC5641685 DOI: 10.1016/j.molmet.2017.07.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/24/2017] [Accepted: 07/31/2017] [Indexed: 01/24/2023] Open
Abstract
Objectives Chronic hyperlipidemia and hyperglycemia are characteristic features of type 2 diabetes (T2DM) that are thought to cause or contribute to β-cell dysfunction by “glucolipotoxicity.” Previously we have shown that acute treatment of pancreatic islets with fatty acids (FA) decreases acetylcholine-potentiated insulin secretion. This acetylcholine response is mediated by M3 muscarinic receptors, which play a key role in regulating β-cell function. Here we examine whether chronic FA exposure also inhibits acetylcholine-potentiated insulin secretion using mouse and human islets. Methods Islets were cultured for 3 or 4 days at different glucose concentration with 0.5 mM palmitic acid (PA) or a 2:1 mixture of PA and oleic acid (OA) at 1% albumin (PA/BSA molar ratio 3.3). Afterwards, the response to glucose and acetylcholine were studied in perifusion experiments. Results FA-induced impairment of insulin secretion and Ca2+ signaling depended strongly on the glucose concentrations of the culture medium. PA and OA in combination reduced acetylcholine potentiation of insulin secretion more than PA alone, both in mouse and human islets, with no evidence of a protective role of OA. In contrast, lipotoxicity was not observed with islets cultured for 3 days in medium containing less than 1 mM glucose and a mixture of glutamine and leucine (7 mM each). High glucose and FAs reduced endoplasmic reticulum (ER) Ca2+ storage capacity; however, preserving ER Ca2+ by blocking the IP3 receptor with xestospongin C did not protect islets from glucolipotoxic effects on insulin secretion. In contrast, an inhibitor of casein kinase 2 (CK2) protected the glucose dependent acetylcholine potentiation of insulin secretion in mouse and human islets against glucolipotoxicity. Conclusions These results show that chronic FA treatment decreases acetylcholine potentiation of insulin secretion and that this effect is strictly glucose dependent and might involve CK2 phosphorylation of β-cell M3 muscarinic receptors. Glucolipotoxicity impairs acetylcholine-potentiation of insulin secretion. Glucose amplification of insulin secretion rather than triggering is damaged by FA. Inhibitor of casein kinase 2 preserved islet function against glucolipotoxicity.
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Affiliation(s)
- Nicolai M Doliba
- Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA.
| | - Qin Liu
- Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Changhong Li
- Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Pan Chen
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Chengyang Liu
- Department of Surgery, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Ali Naji
- Department of Surgery, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
| | - Franz M Matschinsky
- Department of Biochemistry and Biophysics, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA; Institute for Diabetes, Obesity and Metabolism, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104, USA
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11
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Discovery of potent and orally active 1,4-disubstituted indazoles as novel allosteric glucokinase activators. Bioorg Med Chem Lett 2017; 27:2678-2682. [DOI: 10.1016/j.bmcl.2017.04.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/10/2017] [Accepted: 04/12/2017] [Indexed: 01/23/2023]
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12
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Xu J, Lin S, Myers RW, Trujillo ME, Pachanski MJ, Malkani S, Chen HS, Chen Z, Campbell B, Eiermann GJ, Elowe N, Farrer BT, Feng W, Fu Q, Kats-Kagan R, Kavana M, McMasters DR, Mitra K, Tong X, Xu L, Zhang F, Zhang R, Addona GH, Berger JP, Zhang B, Parmee ER. Discovery of orally active hepatoselective glucokinase activators for treatment of Type II Diabetes Mellitus. Bioorg Med Chem Lett 2017; 27:2063-2068. [DOI: 10.1016/j.bmcl.2016.10.088] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/26/2016] [Accepted: 10/28/2016] [Indexed: 01/10/2023]
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13
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Chen Y, Wang X, Wang J, Yang Y. Synthesis of D- manno-heptulose via a cascade aldol/hemiketalization reaction. Beilstein J Org Chem 2017; 13:795-799. [PMID: 28546836 PMCID: PMC5433184 DOI: 10.3762/bjoc.13.79] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 04/12/2017] [Indexed: 11/25/2022] Open
Abstract
A [4 + 3] synthesis of D-manno-heptulose is described. The cascade aldol/hemiketalization reaction of a C4 aldehyde with a C3 ketone provides the differentially protected ketoheptose building block, which can be further reacted to furnish target D-manno-heptulose.
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Affiliation(s)
- Yan Chen
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Xiaoman Wang
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Junchang Wang
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - You Yang
- Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
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14
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Ou Y, Ren Z, Wang J, Yang X. Phycocyanin ameliorates alloxan-induced diabetes mellitus in mice: Involved in insulin signaling pathway and GK expression. Chem Biol Interact 2016; 247:49-54. [DOI: 10.1016/j.cbi.2016.01.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 01/14/2016] [Accepted: 01/22/2016] [Indexed: 11/16/2022]
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15
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Kaufman BA, Li C, Soleimanpour SA. Mitochondrial regulation of β-cell function: maintaining the momentum for insulin release. Mol Aspects Med 2015; 42:91-104. [PMID: 25659350 PMCID: PMC4404204 DOI: 10.1016/j.mam.2015.01.004] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 01/29/2015] [Accepted: 01/29/2015] [Indexed: 01/15/2023]
Abstract
All forms of diabetes share the common etiology of insufficient pancreatic β-cell function to meet peripheral insulin demand. In pancreatic β-cells, mitochondria serve to integrate the metabolism of exogenous nutrients into energy output, which ultimately leads to insulin release. As such, mitochondrial dysfunction underlies β-cell failure and the development of diabetes. Mitochondrial regulation of β-cell function occurs through many diverse pathways, including metabolic coupling, generation of reactive oxygen species, maintenance of mitochondrial mass, and through interaction with other cellular organelles. In this chapter, we will focus on the importance of enzymatic regulators of mitochondrial fuel metabolism and control of mitochondrial mass to pancreatic β-cell function, describing how defects in these pathways ultimately lead to diabetes. Furthermore, we will examine the factors responsible for mitochondrial biogenesis and degradation and their roles in the balance of mitochondrial mass in β-cells. Clarifying the causes of β-cell mitochondrial dysfunction may inform new approaches to treat the underlying etiologies of diabetes.
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Affiliation(s)
- Brett A Kaufman
- Division of Cardiology, Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Changhong Li
- Division of Endocrinology and Diabetes, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Scott A Soleimanpour
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA
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16
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Abstract
The failure of pancreatic β‐cells to supply insulin in quantities sufficient to maintain euglycemia is a hallmark of type 2 diabetes. Perturbation of β‐cell cholesterol homeostasis, culminating in elevated intracellular cholesterol levels, impairs insulin secretion and has therefore been proposed as a mechanism contributing to β‐cell dysfunction. The manner in which this occurs, however, is unclear. Cholesterol is an essential lipid, as well as a major component of membrane rafts, and numerous proteins critical for the regulation of insulin secretion have been reported to associate with these domains. Although this suggests that alterations in membrane rafts could partially account for the reduction in insulin secretion observed when β‐cell cholesterol accumulates, this has not yet been demonstrated. In this review, we provide a brief overview of recent work implicating membrane rafts in some of the basic molecular mechanisms of insulin secretion, and discuss the insight it provides into the β‐cell dysfunction characteristic of type 2 diabetes. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2012.00200.x, 2012)
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Affiliation(s)
- Ronald Dirkx
- Molecular Diabetology, Paul Langerhans Institute Dresden, School of Medicine and University Clinic "Carl Gustav Carus", Dresden University of Technology
| | - Michele Solimena
- Molecular Diabetology, Paul Langerhans Institute Dresden, School of Medicine and University Clinic "Carl Gustav Carus", Dresden University of Technology ; Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
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17
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Lindbloom-Hawley S, LeCluyse M, Vandersande V, Lushington GH, Schermerhorn T. Cloning and characterization of feline islet glucokinase. BMC Vet Res 2014; 10:130. [PMID: 24917242 PMCID: PMC4066705 DOI: 10.1186/1746-6148-10-130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 05/21/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Glucokinase (GK) is a metabolic enzyme encoded by the GCK gene and expressed in glucose-sensitive tissues, principally pancreatic islets cell and hepatocytes. The GK protein acts in pancreatic islets as a "glucose sensor" that couples fluctuations in the blood glucose concentration to changes in cellular function and insulin secretion. GCK and GK have proposed importance in the development and progression of diabetes mellitus and are potential therapeutic targets for diabetes treatment. The study was undertaken to determine the nucleotide sequence of feline pancreatic GK cDNA, predict the amino acid sequence and structure of the feline GK protein, and perform comparative bioinformatic analysis of feline cDNA and protein. Routine PCR techniques were used with cDNA from feline pancreas. Clones were assembled to obtain the full length cDNA. Protein prediction and modeling were performed using bioinformatic tools. RESULTS Full-length feline pancreatic GK cDNA contains a 1398 nucleotide coding sequence with high identity to other pancreatic GK cDNAs. The deduced 465 amino acid feline protein has 15 amino acid substitutions not found in other mammalian GK proteins but maintains high structural homology with human GK. Feline pancreatic GK is highly conserved at nucleotide and protein levels. Residues crucial for substrate binding and catalysis are completely conserved in the feline protein. CONCLUSION Molecular analysis predicts that feline pancreatic GK functions similarly to other mammalian GK proteins.
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Affiliation(s)
| | | | | | | | - Thomas Schermerhorn
- College of Veterinary Medicine, Department of Clinical Sciences, Kansas State University, 1800 Denison Ave, Manhattan, KS 66506-5606, USA.
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18
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Negahdar M, Aukrust I, Molnes J, Solheim MH, Johansson BB, Sagen JV, Dahl-Jørgensen K, Kulkarni RN, Søvik O, Flatmark T, Njølstad PR, Bjørkhaug L. GCK-MODY diabetes as a protein misfolding disease: the mutation R275C promotes protein misfolding, self-association and cellular degradation. Mol Cell Endocrinol 2014; 382:55-65. [PMID: 24001579 DOI: 10.1016/j.mce.2013.08.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 08/22/2013] [Accepted: 08/23/2013] [Indexed: 11/28/2022]
Abstract
GCK-MODY, dominantly inherited mild hyperglycemia, is associated with more than 600 mutations in the glucokinase gene. Different molecular mechanisms have been shown to explain GCK-MODY. Here, we report a Pakistani family harboring the glucokinase mutation c.823C>T (p.R275C). The recombinant and in cellulo expressed mutant pancreatic enzyme revealed slightly increased enzyme activity (kcat) and normal affinity for α-D-glucose, and resistance to limited proteolysis by trypsin comparable with wild-type. When stably expressed in HEK293 cells and MIN6 β-cells (at different levels), the mutant protein appeared misfolded and unstable with a propensity to form dimers and aggregates. Its degradation rate was increased, involving the lysosomal and proteasomal quality control systems. On mutation, a hydrogen bond between the R275 side-chain and the carbonyl oxygen of D267 is broken, destabilizing the F260-L271 loop structure and the protein. This promotes the formation of dimers/aggregates and suggests that an increased cellular degradation is the molecular mechanism by which R275C causes GCK-MODY.
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Affiliation(s)
- Maria Negahdar
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Ingvild Aukrust
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway; Department of Biomedicine, University of Bergen, Bergen, Norway; Section of Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Janne Molnes
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Biomedicine, University of Bergen, Bergen, Norway; Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - Marie H Solheim
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway; Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Bente B Johansson
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway; Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - Jørn V Sagen
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Institute of Medicine, University of Bergen, Bergen, Norway; Hormone Laboratory, Haukeland University Hospital, Bergen, Norway
| | - Knut Dahl-Jørgensen
- Pediatric Department Ullevaal, Oslo University Hospital, Oslo, Norway; Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Rohit N Kulkarni
- Section of Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Oddmund Søvik
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | - Pål R Njølstad
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Department of Pediatrics, Haukeland University Hospital, Bergen, Norway.
| | - Lise Bjørkhaug
- KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway; Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway; Department of Biomedicine, University of Bergen, Bergen, Norway
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19
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Shammas C, Neocleous V, Phelan MM, Lian LY, Skordis N, Phylactou LA. A report of 2 new cases of MODY2 and review of the literature: implications in the search for type 2 diabetes drugs. Metabolism 2013; 62:1535-42. [PMID: 23890519 DOI: 10.1016/j.metabol.2013.06.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 06/11/2013] [Accepted: 06/11/2013] [Indexed: 10/26/2022]
Abstract
Glucokinase (GCK) acts as a glucose sensor and stimulates the release of insulin from pancreatic β-cells and any GCK gene mutations can lead to different forms of diabetes, such as GCK-monogenic diabetes of the young type 2 (MODY2), permanent neonatal diabetes and congenital hyperinsulinism. Many MODY2 causing mutations display a variation in the degree of severity, ranging from mild dietary-restricted forms to more detrimental presentation requiring insulin replacement. The present study reviews known and two novel GCK mutations in terms of molecular perturbation of the GCK atomic structure but also emphasizes the inactivating and activating properties of the GCK as treatment for T2DM. In silico analysis demonstrated that the newly discovered mutation p.Arg447Pro causes structural conformational changes that lead to the destabilization of the functional properties of the protein resulting in the reduction of glucose and MgATP2- affinity. The novel p.Glu440Stop nonsense mutation on the other hand inactivates the cytoplasmic enzymatic activity of the protein as it is responsible for the loss of the C-terminal end of the polypeptide that includes vital glucose-releasing residues. Based on the in silico models of existing structural data we identified several classes of GCK mutations and discuss their relation to disease outcome. GCK has a central role in controlling body glucose homeostasis and therefore is considered an outstanding drug target for developing new antidiabetic therapies using small molecular activators (GKAs). This study emphasizes the importance in understanding how inactivating and activating GCK mutations affect the mechanistic properties of this glucose sensor. Such information can become the basis for drug discovery of therapeutic compounds and the treatment of T2DM by targeting the GCK allosteric activator site.
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Affiliation(s)
- Christos Shammas
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, P.O. Box 23462, 1683 Nicosia, Cyprus
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20
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Pathogenesis of the metabolic syndrome: insights from monogenic disorders. Mediators Inflamm 2013; 2013:920214. [PMID: 23766565 PMCID: PMC3673346 DOI: 10.1155/2013/920214] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/18/2013] [Indexed: 12/16/2022] Open
Abstract
Identifying rare human metabolic disorders that result from a single-gene defect has not only enabled improved diagnostic and clinical management of such patients, but also has resulted in key biological insights into the pathophysiology of the increasingly prevalent metabolic syndrome. Insulin resistance and type 2 diabetes are linked to obesity and driven by excess caloric intake and reduced physical activity. However, key events in the causation of the metabolic syndrome are difficult to disentangle from compensatory effects and epiphenomena. This review provides an overview of three types of human monogenic disorders that result in (1) severe, non-syndromic obesity, (2) pancreatic beta cell forms of early-onset diabetes, and (3) severe insulin resistance. In these patients with single-gene defects causing their exaggerated metabolic disorder, the primary defect is known. The lessons they provide for current understanding of the molecular pathogenesis of the common metabolic syndrome are highlighted.
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21
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Pautsch A, Stadler N, Löhle A, Rist W, Berg A, Glocker L, Nar H, Reinert D, Lenter M, Heckel A, Schnapp G, Kauschke SG. Crystal Structure of Glucokinase Regulatory Protein. Biochemistry 2013; 52:3523-31. [DOI: 10.1021/bi4000782] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexander Pautsch
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Nadja Stadler
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Adelheid Löhle
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Wolfgang Rist
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Adina Berg
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Lucia Glocker
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Herbert Nar
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Dirk Reinert
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Martin Lenter
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Armin Heckel
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Gisela Schnapp
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
| | - Stefan G. Kauschke
- Departments of Lead Identification and Optimization Support, ‡CardioMetabolic Diseases Research, §CNS Diseases Research, ∥Drug Discovery Support, ⊥BP Process Science, and @Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Company KG, Biberach an der Riss, Germany
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22
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Cheruvallath ZS, Gwaltney SL, Sabat M, Tang M, Feng J, Wang H, Miura J, Guntupalli P, Jennings A, Hosfield D, Lee B, Wu Y. Design, synthesis and SAR of novel glucokinase activators. Bioorg Med Chem Lett 2013; 23:2166-71. [DOI: 10.1016/j.bmcl.2013.01.093] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 01/17/2013] [Accepted: 01/22/2013] [Indexed: 10/27/2022]
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23
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Bonn P, Brink DM, Fägerhag J, Jurva U, Robb GR, Schnecke V, Svensson Henriksson A, Waring MJ, Westerlund C. The discovery of a novel series of glucokinase activators based on a pyrazolopyrimidine scaffold. Bioorg Med Chem Lett 2012; 22:7302-5. [DOI: 10.1016/j.bmcl.2012.10.090] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 10/16/2012] [Accepted: 10/19/2012] [Indexed: 10/27/2022]
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Doliba NM, Fenner D, Zelent B, Bass J, Sarabu R, Matschinsky FM. Repair of diverse diabetic defects of β-cells in man and mouse by pharmacological glucokinase activation. Diabetes Obes Metab 2012; 14 Suppl 3:109-19. [PMID: 22928571 PMCID: PMC4433321 DOI: 10.1111/j.1463-1326.2012.01652.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Glucokinase activators (GKAs) are being developed and clinically tested for potential antidiabetic therapy. The potential benefits and limitations of this approach continue to be intensively debated. To contribute to the understanding of experimental pharmacology and therapeutics of GKAs, we have tested the efficacy of one of these agents (Piragliatin) in isolated islets from humans with type 2 diabetes mellitus (T2DM), from mice with glucokinase (GK) mutations induced by ethyl-nitroso-urea (ENU) as models of Maturity Onset Diabetes of the Young linked to GK and Permanent Neonatal Diabetes Mellitus linked to GK (PNDM-GK) and finally of islets rendered glucose insensitive by treatment with the sulphonyl urea compound glyburide in organ culture. We found that the GKA repaired the defect in all three instances as manifest in increased glucose-induced insulin release and elevated intracellular calcium responses. The results show the remarkable fact that acute pharmacological activation of GK reverses secretion defects of β-cells caused by molecular mechanism that differ vastly in nature, including the little understood multifactorial lesion of β-cells in T2DM of man, the complex GK mutations in mice resembling GK disease and acute sulphonylurea failure of mouse β-cells in tissue culture. The implications of these results are to be discussed on the theoretical basis underpinning the strategy of developing these drugs and in light of recent results of clinical trials with GKAs that failed for little understood reasons.
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25
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Baltrusch S, Schmitt H, Brix A, Langer S, Lenzen S. Additive activation of glucokinase by the bifunctional enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase and the chemical activator LY2121260. Biochem Pharmacol 2012; 83:1300-6. [DOI: 10.1016/j.bcp.2012.01.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 01/16/2012] [Accepted: 01/17/2012] [Indexed: 10/14/2022]
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26
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Larion M, Miller BG. Homotropic allosteric regulation in monomeric mammalian glucokinase. Arch Biochem Biophys 2012; 519:103-11. [PMID: 22107947 PMCID: PMC3294010 DOI: 10.1016/j.abb.2011.11.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 11/03/2011] [Accepted: 11/04/2011] [Indexed: 11/30/2022]
Abstract
Glucokinase catalyzes the ATP-dependent phosphorylation of glucose, a chemical transformation that represents the rate-limiting step of glycolytic metabolism in the liver and pancreas. Glucokinase is a central regulator of glucose homeostasis as evidenced by its association with two disease states, maturity onset diabetes of the young (MODY) and persistent hyperinsulinemia of infancy (PHHI). Mammalian glucokinase is subject to homotropic allosteric regulation by glucose-the steady-state velocity of glucose-6-phosphate production is not hyperbolic, but instead displays a sigmoidal response to increasing glucose concentrations. The positive cooperativity displayed by glucokinase is intriguing since the enzyme functions as a monomer under physiological conditions and contains only a single binding site for glucose. Despite the existence of several models of kinetic cooperativity in monomeric enzymes, a consensus has yet to be reached regarding the mechanism of allosteric regulation in glucokinase. Experimental evidence collected over the last 45 years by a number of investigators supports a link between cooperativity and slow conformational reorganizations of the glucokinase scaffold. In this review, we summarize advances in our understanding of glucokinase allosteric regulation resulting from recent X-ray crystallographic, pre-equilibrium kinetic and high-resolution nuclear magnetic resonance investigations. We conclude with a brief discussion of unanswered questions regarding the mechanistic basis of kinetic cooperativity in mammalian glucokinase.
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Affiliation(s)
- Mioara Larion
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306-4390, USA
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27
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García-Herrero CM, Rubio-Cabezas O, Azriel S, Gutierrez-Nogués A, Aragonés A, Vincent O, Campos-Barros A, Argente J, Navas MA. Functional characterization of MODY2 mutations highlights the importance of the fine-tuning of glucokinase and its role in glucose sensing. PLoS One 2012; 7:e30518. [PMID: 22291974 PMCID: PMC3265476 DOI: 10.1371/journal.pone.0030518] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 12/17/2011] [Indexed: 11/19/2022] Open
Abstract
Glucokinase (GK) acts as a glucose sensor in the pancreatic beta-cell and regulates insulin secretion. Heterozygous mutations in the human GK-encoding GCK gene that reduce the activity index increase the glucose-stimulated insulin secretion threshold and cause familial, mild fasting hyperglycaemia, also known as Maturity Onset Diabetes of the Young type 2 (MODY2). Here we describe the biochemical characterization of five missense GK mutations: p.Ile130Thr, p.Asp205His, p.Gly223Ser, p.His416Arg and p.Ala449Thr. The enzymatic analysis of the corresponding bacterially expressed GST-GK mutant proteins show that all of them impair the kinetic characteristics of the enzyme. In keeping with their position within the protein, mutations p.Ile130Thr, p.Asp205His, p.Gly223Ser, and p.His416Arg strongly decrease the activity index of GK, affecting to one or more kinetic parameters. In contrast, the p.Ala449Thr mutation, which is located in the allosteric activator site, does not affect significantly the activity index of GK, but dramatically modifies the main kinetic parameters responsible for the function of this enzyme as a glucose sensor. The reduced Kcat of the mutant (3.21±0.28 s(-1) vs 47.86±2.78 s(-1)) is balanced by an increased glucose affinity (S(0.5) = 1.33±0.08 mM vs 7.86±0.09 mM) and loss of cooperativity for this substrate. We further studied the mechanism by which this mutation impaired GK kinetics by measuring the differential effects of several competitive inhibitors and one allosteric activator on the mutant protein. Our results suggest that this mutation alters the equilibrium between the conformational states of glucokinase and highlights the importance of the fine-tuning of GK and its role in glucose sensing.
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Affiliation(s)
- Carmen-María García-Herrero
- Departamento de Bioquímica y Biología Molecular III, Facultad de Medicina, Universidad Complutense de Madrid and Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), www.ciberdem.net, Instituto de Salud Carlos III, Madrid, Spain
| | - Oscar Rubio-Cabezas
- Servicio de Endocrinología, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Departamento de Pediatría, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y Nutrición (CIBEROBN), www.ciberobn.es, Instituto de Salud Carlos III, Madrid, Spain
| | - Sharona Azriel
- Servicio de Endocrinología, Hospital Universitario Infanta Sofía, San Sebastián de los Reyes, Madrid, Spain
| | - Angel Gutierrez-Nogués
- Departamento de Bioquímica y Biología Molecular III, Facultad de Medicina, Universidad Complutense de Madrid and Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - Angel Aragonés
- Servicio de Pediatría, Hospital Virgen de la Salud, Toledo, Spain
| | - Olivier Vincent
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, Madrid, Spain
| | - Angel Campos-Barros
- Servicio de Endocrinología, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Departamento de Pediatría, Universidad Autónoma de Madrid, Madrid, Spain
| | - Jesús Argente
- Servicio de Endocrinología, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Departamento de Pediatría, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red de la Fisiopatología de la Obesidad y Nutrición (CIBEROBN), www.ciberobn.es, Instituto de Salud Carlos III, Madrid, Spain
| | - María-Angeles Navas
- Departamento de Bioquímica y Biología Molecular III, Facultad de Medicina, Universidad Complutense de Madrid and Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas (CIBERDEM), www.ciberdem.net, Instituto de Salud Carlos III, Madrid, Spain
- * E-mail:
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Waring MJ, Clarke DS, Fenwick MD, Godfrey L, Groombridge SD, Johnstone C, McKerrecher D, Pike KG, Rayner JW, Robb GR, Wilson I. Property based optimisation of glucokinase activators – discovery of the phase IIb clinical candidate AZD1656. MEDCHEMCOMM 2012. [DOI: 10.1039/c2md20077e] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Waschke D, Leshch Y, Thimm J, Himmelreich U, Thiem J. Synthesis of Fluorinated Ketoheptoses as Specific Diagnostic Agents. European J Org Chem 2011. [DOI: 10.1002/ejoc.201101238] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Curcumin-supplemented yoghurt improves physiological and biochemical markers of experimental diabetes. Br J Nutr 2011; 108:440-8. [PMID: 22067670 DOI: 10.1017/s0007114511005769] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We investigated the effects of prolonged treatment of diabetic rats with curcumin-supplemented yoghurt on the physiological and biochemical changes associated with diabetes mellitus. An established metabolic cage model was used to assess these changes in three groups of streptozotocin-diabetic rats which had been administered, by gavage, curcumin blended into yoghurt in the doses of 30, 60 and 90 mg/kg body weight (BW) per d (groups DC30, DC60, DC90) for 31 d. One group of non-diabetic rats was also treated with 90 mg/kg BW per d curcumin (NDC90). Three control groups of diabetic animals received water (DW), yoghurt (DY) and insulin at 27·78 μmol/d by subcutaneous injection (DI). Also, two groups of non-diabetic animals received water (NDW) and yoghurt (NDY). Groups DI and DC90 exhibited significant falls, relative to DW and DY, in food and water intake, urine volume, glycaemia, urinary urea and glucose, proteinuria, serum TAG and activities of aspartate and alanine aminotransferases, and higher hepatic glycogen and BW. These improvements were greater in DI than in DC90. No difference was observed in the serum levels of total cholesterol or HDL-cholesterol, or in the masses of adipose and muscular tissues, between DC90 and DW or DY. Moreover, the improvements in curcumin-treated rats, relative to DW and DY, were significant and dose-dependent. The NDC90 group also showed no difference from the NDW or NDY groups, in any of the markers for diabetes. In conclusion, curcumin mixed into yoghurt at the highest dose tested exhibited anti-diabetic activity, improving significantly most of the markers assessed in this study.
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Polakof S, Míguez JM, Soengas JL. Ghrelin effects on central glucosensing and energy homeostasis-related peptides in rainbow trout. Domest Anim Endocrinol 2011; 41:126-36. [PMID: 21798689 DOI: 10.1016/j.domaniend.2011.05.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 05/22/2011] [Accepted: 05/24/2011] [Indexed: 12/23/2022]
Abstract
Although the role of ghrelin (GHRL) on fish appetite regulation had been widely studied in past years, its involvement in the regulation of glucose metabolism had been little explored. In the present study we hypothesize that GHRL may have a role in the regulation of glucose homeostasis in fish. Therefore, we carried out different experimental approaches in rainbow trout to assess brain glucosensing potential and glucose metabolism in response to GHRL treatment. We found that after either systemic or central GHRL administration to trout deprived of food, glycemia remained unaffected, whereas (in clear contrast with the mammalian model) a consistent activation of the main glucosensing markers (glucose transporter 2, glucokinase, and ATP-sensitive inward rectified K+ channel) was noticed in both hypothalamus and hindbrain. Some of these results were further confirmed by in vitro incubations of hypothalamus and hindbrain in the presence of GHRL. Despite the lack of changes in glycemia, we suggest that the changes elicited by GHRL on the glucosensing system are direct and could be related to a helper action of this hormone when glucose arrived in the postprandial phase. Moreover, we also studied the effect of GHRL treatment on the expression of several food intake-related neuropeptides, such as neuropeptide Y, cocaine- and amphetamine-regulated transcript, pro-opiomelanocortin, and corticotropin-releasing factor. We observed an important variability in the effects of GHRL attributable either to the route of GHRL administration or to the brain regions assessed, which could help explain the contradictory results described in fish literature about GHRL role in food intake control.
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Affiliation(s)
- S Polakof
- Laboratorio de Fisioloxía Animal, Departamento de Bioloxía Funcional e Ciencias da Saúde, Facultade de Bioloxía, Universidade de Vigo, 36310 Vigo, Spain.
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Lang M, Seifert MHJ, Wolf KK, Aschenbrenner A, Baumgartner R, Wieber T, Trentinaglia V, Blisse M, Tajima N, Yamashita T, Vitt D, Noda H. Discovery and hit-to-lead optimization of novel allosteric glucokinase activators. Bioorg Med Chem Lett 2011; 21:5417-22. [DOI: 10.1016/j.bmcl.2011.06.128] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 06/30/2011] [Accepted: 06/30/2011] [Indexed: 12/01/2022]
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Rationalization of physicochemical characters and docking of 3-alkoxy-5-phenoxy-N-thiazolyl benzamide analogs toward glucokinase activator activity. Med Chem Res 2011. [DOI: 10.1007/s00044-011-9740-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Schmitt H, Lenzen S, Baltrusch S. Glucokinase mediates coupling of glycolysis to mitochondrial metabolism but not to beta cell damage at high glucose exposure levels. Diabetologia 2011; 54:1744-55. [PMID: 21484215 DOI: 10.1007/s00125-011-2133-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Accepted: 02/02/2011] [Indexed: 01/08/2023]
Abstract
AIMS/HYPOTHESIS Glucose is the main stimulus of insulin secretion in pancreatic beta cells. However, high glucose has also been considered to damage beta cells. In this study we examined, with special emphasis on the role of the glucose sensor enzyme glucokinase, whether elevated glucose metabolism evokes toxicity to beta cells. METHODS RINm5F-R-EYFP-GK cells, producing glucokinase in response to a synthetic inducer, and rat beta cells were incubated at different glucose concentrations. Glucokinase enzyme activity, insulin secretion, cell viability and mitochondrial metabolism were analysed. RESULTS Glucokinase production evoked a concentration-dependent increase in glucose-induced insulin secretion from RINm5F-R-EYFP-GK cells without reducing cell viability. Pre-culture at high glucose (30 mmol/l) in the absence of high concentrations of NEFA neither reduced viability nor significantly increased apoptosis in RINm5F-R-EYFP-GK cells and rat beta cells. The integrity of the mitochondrial respiratory chain and mitochondrial dynamics, namely fusion and fission, were not impaired by high glucose pre-culture. As previously demonstrated in mouse beta cells, pre-culture at high glucose significantly decreased the mitochondrial membrane potential heterogeneity in RINm5F-R-EYFP-GK cells. Indeed, after starvation, in response to glucose, rat beta cells and RINm5F-R-EYFP-GK cells with glucokinase production pre-cultured for 48 h at high glucose showed the fastest increase in the mitochondrial membrane potential. CONCLUSIONS/INTERPRETATION Our experiments do not support the hypothesis that glucokinase and the glucose metabolism on its own act as a mediator of beta cell toxicity. By contrast, rather a beneficial effect on glucose-induced insulin secretion after glucokinase production was observed, based on an improved coupling of the glucose stimulus to the mitochondrial metabolism.
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Affiliation(s)
- H Schmitt
- Institute of Clinical Biochemistry, Hannover Medical School, 30623 Hannover, Germany
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Pike KG, Allen JV, Caulkett PW, Clarke DS, Donald CS, Fenwick ML, Johnson KM, Johnstone C, McKerrecher D, Rayner JW, Walker RP, Wilson I. Design of a potent, soluble glucokinase activator with increased pharmacokinetic half-life. Bioorg Med Chem Lett 2011; 21:3467-70. [DOI: 10.1016/j.bmcl.2011.03.093] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 03/21/2011] [Accepted: 03/22/2011] [Indexed: 01/23/2023]
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Mirasierra M, Fernández-Pérez A, Díaz-Prieto N, Vallejo M. Alx3-deficient mice exhibit decreased insulin in beta cells, altered glucose homeostasis and increased apoptosis in pancreatic islets. Diabetologia 2011; 54:403-14. [PMID: 21104068 DOI: 10.1007/s00125-010-1975-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 10/20/2010] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS Homeodomain transcription factors play an important role in the regulation of pancreatic islet function. In previous studies we determined that aristaless-like homeobox 3 (ALX3) is produced in islet cells, binds to the promoter of the insulin gene and regulates its expression. The purpose of the present study was to investigate the functional role of ALX3 in pancreatic islets and its possible involvement in the regulation of glucose homeostasis in vivo. METHODS Alx3-knockout mice were used. Glucose and insulin tolerance tests were carried out, and serum insulin concentrations were determined. Isolated islets were used to test insulin secretion and gene expression. The pancreatic islets were also studied using both confocal and conventional microscopy. RESULTS ALX3 deficiency resulted in increased blood glucose levels and impaired glucose tolerance in the presence of normal serum insulin concentrations. Insulin, glucagon and glucokinase expression were reduced in Alx3-null pancreatic islets. Reduced insulin content was reflected by decreased insulin secretion from isolated islets. Alx3-deficient islets also showed increased apoptosis, and morphometric analyses indicated that they were, on average, of smaller size than islets from control mice. ALX3 deficiency resulted in reduced beta cell mass. Finally, mature Alx3-null mice developed age-dependent insulin resistance due to impaired peripheral insulin receptor signalling. CONCLUSIONS/INTERPRETATION ALX3 participates in the regulation of the expression of essential genes for the function of pancreatic islets, and its deficiency alters the regulation of glucose homeostasis in vivo. We suggest that ALX3 constitutes a potential candidate to consider in the aetiopathogenesis of diabetes mellitus.
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Affiliation(s)
- M Mirasierra
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas /Universidad Autónoma de Madrid, Calle Arturo Duperier 4, 28029 Madrid, Spain
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Waring MJ, Johnstone C, McKerrecher D, Pike KG, Robb G. Matrix-based multiparameter optimisation of glucokinase activators: the discovery of AZD1092. MEDCHEMCOMM 2011. [DOI: 10.1039/c1md00092f] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Waring MJ, Brogan IJ, Coghlan M, Johnstone C, Jones HB, Leighton B, McKerrecher D, Pike KG, Robb GR. Overcoming retinoic acid receptor-α based testicular toxicity in the optimisation of glucokinase activators. MEDCHEMCOMM 2011. [DOI: 10.1039/c1md00090j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Matschinsky FM, Zelent B, Doliba NM, Kaestner KH, Vanderkooi JM, Grimsby J, Berthel SJ, Sarabu R. Research and development of glucokinase activators for diabetes therapy: theoretical and practical aspects. Handb Exp Pharmacol 2011:357-401. [PMID: 21484579 DOI: 10.1007/978-3-642-17214-4_15] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Glucokinase Glucokinase (GK GK ; EC 2.7.1.1.) phosphorylates and regulates glucose metabolism in insulin-producing pancreatic beta-cells, hepatocytes, and certain cells of the endocrine and nervous systems allowing it to play a central role in glucose homeostasis glucose homeostasis . Most importantly, it serves as glucose sensor glucose sensor in pancreatic beta-cells mediating glucose-stimulated insulin biosynthesis and release and it governs the capacity of the liver to convert glucose to glycogen. Activating and inactivating mutations of the glucokinase gene cause autosomal dominant hyperinsulinemic hypoglycemia and hypoinsulinemic hyperglycemia in humans, respectively, illustrating the preeminent role of glucokinase in the regulation of blood glucose and also identifying the enzyme as a potential target for developing antidiabetic drugs antidiabetic drugs . Small molecules called glucokinase activators (GKAs) glucokinase activators (GKAs) which bind to an allosteric activator allosteric activator site of the enzyme have indeed been discovered and hold great promise as new antidiabetic agents. GKAs increase the enzyme's affinity for glucose and also its maximal catalytic rate. Consequently, they stimulate insulin biosynthesis and secretion, enhance hepatic glucose uptake, and augment glucose metabolism and related processes in other glucokinase-expressing cells. Manifestations of these effects, most prominently a lowering of blood glucose, are observed in normal laboratory animals and man but also in animal models of diabetes and patients with type 2 diabetes mellitus (T2DM T2DM ) type 2 diabetes mellitus (T2DM) . These compelling concepts and results sustain a strong R&D effort by many pharmaceutical companies to generate GKAs with characteristics allowing for a novel drug treatment of T2DM.
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Affiliation(s)
- Franz M Matschinsky
- Department of Biochemistry and Biophysics, University of Pennsylvania, Institute for Diabetes, Obesity and Metabolism, 415 Curie Blvd, 605 CRB, Philadelphia, PA 19104, USA.
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Yang J, Chi Y, Burkhardt BR, Guan Y, Wolf BA. Leucine metabolism in regulation of insulin secretion from pancreatic beta cells. Nutr Rev 2010; 68:270-9. [PMID: 20500788 DOI: 10.1111/j.1753-4887.2010.00282.x] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Leucine, a branched-chain amino acid that must be supplied in the daily diet, plays an important role in controlling protein synthesis and regulating cell metabolism in various cell types. In pancreatic beta cells, leucine acutely stimulates insulin secretion by serving as both metabolic fuel and allosteric activator of glutamate dehydrogenase to enhance glutaminolysis. Leucine has also been shown to regulate gene transcription and protein synthesis in pancreatic islet beta cells via both mTOR-dependent and -independent pathways at physiological concentrations. Long-term treatment with leucine has been shown to improve insulin secretory dysfunction of human diabetic islets via upregulation of certain key metabolic genes. In vivo, leucine administration improves glycemic control in humans and rodents with type 2 diabetes. This review summarizes and discusses the recent findings regarding the effects of leucine metabolism on pancreatic beta-cell function.
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Affiliation(s)
- Jichun Yang
- Department of Physiology and Pathophysiology, Peking University Diabetes Center, Peking University Health Science Center, Beijing, China.
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Shankaraia P, Narsimha R Y, Venkatesha A, Venkata Ra N, Krishna D. Differential Expression of Glucokinase activity in Indian Type-2 Diabetes Patients. INT J PHARMACOL 2010. [DOI: 10.3923/ijp.2010.500.504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Martens GA, Pipeleers D. Glucose, regulator of survival and phenotype of pancreatic beta cells. VITAMINS AND HORMONES 2009; 80:507-39. [PMID: 19251048 DOI: 10.1016/s0083-6729(08)00617-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The key role of glucose in regulating insulin release by the pancreatic beta cell population is not only dependent on acute stimulus-secretion coupling mechanisms but also on more long-term influences on beta cell survival and phenotype. Glucose serves as a major survival factor for beta cells via at least three actions: it prevents an oxidative redox state, it suppresses a mitochondrial apoptotic program that is triggered at reduced mitochondrial metabolic activity and it induces genes needed for the cellular responsiveness to glucose and to growth factors. Glucose-regulated pathways may link protein synthetic and proliferative activities, making glucose a permissive factor for beta cell proliferation, in check with metabolic needs. Conditions of inadequate glucose metabolism in beta cells are not only leading to deregulation of acute secretory responses but should also be considered as causes for increased apoptosis and reduced formation of beta cells, and loss of their normal differentiated state.
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Abstract
Glucokinase, a unique isoform of the hexokinase enzymes, which are known to phosphorylate D-glucose and other hexoses, was identified during the past three to four decades as a new, promising drug target for type 2 diabetes. Glucokinase serves as a glucose sensor of the insulin-producing pancreatic islet beta-cells, controls the conversion of glucose to glycogen in the liver and regulates hepatic glucose production. Guided by this fundamental knowledge, several glucokinase activators are now being developed, and have so far been shown to lower blood glucose in several animal models of type 2 diabetes and in initial trials in humans with the disease. Here, the scientific basis and current status of this new approach to diabetes therapy are discussed.
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Adewole SO, Ojewole JAO. Protective effects of Annona muricata Linn. (Annonaceae) leaf aqueous extract on serum lipid profiles and oxidative stress in hepatocytes of streptozotocin-treated diabetic rats. AFRICAN JOURNAL OF TRADITIONAL, COMPLEMENTARY, AND ALTERNATIVE MEDICINES 2008; 6:30-41. [PMID: 20162039 DOI: 10.4314/ajtcam.v6i1.57071] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Extracts from various morphological parts of Annona muricata Linn. (Annonaceae) are widely used medicinally in many parts of the world for the management, control and/or treatment of a plethora of human ailments, including diabetes mellitus (DM). The present study was undertaken to investigate the possible protective effects of A. muricata leaf aqueous extract (AME) in rat experimental paradigms of DM. The animals used were broadly divided into four (A, B, C and D) experimental groups. Group A rats served as 'control' animals and received distilled water in quantities equivalent to the administered volumes of AME and reference drugs' solutions intraperitoneally. Diabetes mellitus was induced in Groups B and C rats by intraperitoneal injections of streptozotocin (STZ, 70 mg kg(-1)). Group C rats were additionally treated with AME (100 mg kg(-1) day(-1), p.o.) as from day 3 post STZ injection, for four consecutive weeks. Group D rats received AME (100 mg kg(-1) day(-1) p.o.) only for four weeks. Post-euthanization, hepatic tissues were excised and processed biochemically for antioxidant enzymes and lipid profiles, such as catalase (CAT), reactive oxygen species (ROS), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), thiobarbituric acid reactive substances (TBARS), triglycerides (TG), total cholesterol (TC), high density lipoprotein (HDL) and low density lipoprotein (LDL), respectively. Treatment of Groups B and C rats with STZ (70 mg kg(-1) i. p.) resulted in hyperglycaemia, hypoinsulinaemia, and increased TBARS, ROS, TC, TG and LDL levels. STZ treatment also significantly decreased (p<0.05) CAT, GSH, SOD, GSH-Px activities, and HDL levels. AME-treated Groups C and D rats showed significant decrease (p<0.05) in elevated blood glucose, ROS, TBARS, TC, TG and LDL. Furthermore, AME treatment significantly increased (p<0.05) antioxidant enzymes' activities, as well as serum insulin levels. The findings of this laboratory animal study suggest that A. muricata extract has a protective, beneficial effect on hepatic tissues subjected to STZ-induced oxidative stress, possibly by decreasing lipid peroxidation and indirectly enhancing production of insulin and endogenous antioxidants.
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Affiliation(s)
- Stephen O Adewole
- Department of Pharmacology, School of Pharmacy & Pharmacology, Faculty of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
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Wolff M, Kauschke SG, Schmidt S, Heilker R. Activation and Translocation of Glucokinase in Rat Primary Hepatocytes Monitored by High Content Image Analysis. ACTA ACUST UNITED AC 2008; 13:837-46. [DOI: 10.1177/1087057108323910] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In the liver, glucokinase (GK) regulatory protein (GKRP) negatively modulates the metabolic enzyme GK by locking it in an inactive state in the nucleus. Here, the authors established a high content screening assay in the 384-well microplate format to measure the nucleus-to-cytoplasm translocation of GK by reagents that destabilize the interaction between GK and GKRP. As a cellular model system, primary rat hepatocytes endogenously expressing both GK and GKRP at physiological levels were used. The GK translocation assay was robust, displayed limited day-to-day variability, and delivered good Z′ statistics. The increase of the glucose concentration in the extracellular medium from a low glucose situation (2.8 mM) to beyond its physiological set point value of 5 mM was found to drive GK from the nucleus into the cytoplasm. Likewise, both fructose (converted intracellularly into fructose-1-phosphate) and a known allosteric GK activator were found to induce the export of GK from the nucleus and to synergistically enhance the effects of medium or high glucose concentrations with respect to GK translocation. Transfer of the high content screening format to a semiautomated medium throughput screening platform enabled the profiling of large compound numbers with respect to allosteric activation of GK. ( Journal of Biomolecular Screening 2008:837-846)
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Affiliation(s)
- Michael Wolff
- Department of Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Stefan G. Kauschke
- Department of Metabolic Diseases Research, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Susanne Schmidt
- Department of Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Ralf Heilker
- Department of Lead Discovery, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany, -ingelheim.com
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Abstract
An explosion of work over the last decade has produced insight into the multiple hereditary causes of a nonimmunological form of diabetes diagnosed most frequently within the first 6 months of life. These studies are providing increased understanding of genes involved in the entire chain of steps that control glucose homeostasis. Neonatal diabetes is now understood to arise from mutations in genes that play critical roles in the development of the pancreas, of beta-cell apoptosis and insulin processing, as well as the regulation of insulin release. For the basic researcher, this work is providing novel tools to explore fundamental molecular and cellular processes. For the clinician, these studies underscore the need to identify the genetic cause underlying each case. It is increasingly clear that the prognosis, therapeutic approach, and genetic counseling a physician provides must be tailored to a specific gene in order to provide the best medical care.
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Affiliation(s)
- Lydia Aguilar-Bryan
- Pacific Northwest Diabetes Research Institute, 720 Broadway, Seattle, Washington 98122, USA.
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Estalella I, Garcia-Gimeno MA, Marina A, Castaño L, Sanz P. Biochemical characterization of novel glucokinase mutations isolated from Spanish maturity-onset diabetes of the young (MODY2) patients. J Hum Genet 2008; 53:460-466. [DOI: 10.1007/s10038-008-0271-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2008] [Accepted: 02/14/2008] [Indexed: 10/22/2022]
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MacDonald MJ, Longacre MJ, Stoker SW, Brown LJ, Hasan NM, Kendrick MA. Acetoacetate and β-hydroxybutyrate in combination with other metabolites release insulin from INS-1 cells and provide clues about pathways in insulin secretion. Am J Physiol Cell Physiol 2008; 294:C442-50. [DOI: 10.1152/ajpcell.00368.2007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondrial anaplerosis is important for insulin secretion, but only some of the products of anaplerosis are known. We discovered novel effects of mitochondrial metabolites on insulin release in INS-1 832/13 cells that suggested pathways to some of these products. Acetoacetate, β-hydroxybutyrate, α-ketoisocaproate (KIC), and monomethyl succinate (MMS) alone did not stimulate insulin release. Lactate released very little insulin. When acetoacetate, β-hydroxybutyrate, or KIC were combined with MMS, or either ketone body was combined with lactate, insulin release was stimulated 10-fold to 20-fold the controls (almost as much as with glucose). Pyruvate was a potent stimulus of insulin release. In rat pancreatic islets, β-hydroxybutyrate potentiated MMS- and glucose-induced insulin release. The pathways of their metabolism suggest that, in addition to producing ATP, the ketone bodies and KIC supply the acetate component and MMS supplies the oxaloacetate component of citrate. In line with this, citrate was increased by β-hydroxybutyrate plus MMS in INS-1 cells and by β-hydroxybutyrate plus succinate in mitochondria. The two ketone bodies and KIC can also be metabolized to acetoacetyl-CoA and acetyl-CoA, which are precursors of other short-chain acyl-CoAs (SC-CoAs). Measurements of SC-CoAs by LC-MS/MS in INS-1 cells confirmed that KIC, β-hydroxybutyrate, glucose, and pyruvate increased the levels of acetyl-CoA, acetoacetyl-CoA, succinyl-CoA, hydroxymethylglutaryl-CoA, and malonyl-CoA. MMS increased incorporation of14C from β-hydroxybutyrate into citrate, acid-precipitable material, and lipids, suggesting that the two molecules complement one another to increase anaplerosis. The results suggest that, besides citrate, some of the products of anaplerosis are SC-CoAs, which may be precursors of molecules involved in insulin secretion.
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Abstract
Type-2 diabetes is associated with impaired glucose clearance by the liver in the postprandial state, and with elevated glucose production in the post-absorptive state. New targets within the liver are currently being investigated for development of antihyperglycaemic drugs for type-2 diabetes. They include glucokinase, which catalyses the first step in glucose metabolism, the glucagon receptor, and enzymes of gluconeogenesis and/or glycogenolysis such as glucose 6-phosphatase, fructose 1,6-bisphosphatase and glycogen phosphorylase. Preclinical studies with candidate drugs on animal models or cell-based assays suggest that these targets have the potential for pharmacological glycaemic control. Data from clinical studies is awaited. Further work is required for better understanding of the implications of targeting these sites in terms of possible side-effects or tachyphylaxis. The advantage of combined targeting of two or more sites within the liver for minimizing side-effects and tachyphylaxis caused by single-site targeting is discussed.
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Affiliation(s)
- Loranne Agius
- Institute of Cellular Medicine, School of Clinical Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
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