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Deepa Maheshvare M, Raha S, König M, Pal D. A pathway model of glucose-stimulated insulin secretion in the pancreatic β-cell. Front Endocrinol (Lausanne) 2023; 14:1185656. [PMID: 37600713 PMCID: PMC10433753 DOI: 10.3389/fendo.2023.1185656] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/08/2023] [Indexed: 08/22/2023] Open
Abstract
The pancreas plays a critical role in maintaining glucose homeostasis through the secretion of hormones from the islets of Langerhans. Glucose-stimulated insulin secretion (GSIS) by the pancreatic β-cell is the main mechanism for reducing elevated plasma glucose. Here we present a systematic modeling workflow for the development of kinetic pathway models using the Systems Biology Markup Language (SBML). Steps include retrieval of information from databases, curation of experimental and clinical data for model calibration and validation, integration of heterogeneous data including absolute and relative measurements, unit normalization, data normalization, and model annotation. An important factor was the reproducibility and exchangeability of the model, which allowed the use of various existing tools. The workflow was applied to construct a novel data-driven kinetic model of GSIS in the pancreatic β-cell based on experimental and clinical data from 39 studies spanning 50 years of pancreatic, islet, and β-cell research in humans, rats, mice, and cell lines. The model consists of detailed glycolysis and phenomenological equations for insulin secretion coupled to cellular energy state, ATP dynamics and (ATP/ADP ratio). Key findings of our work are that in GSIS there is a glucose-dependent increase in almost all intermediates of glycolysis. This increase in glycolytic metabolites is accompanied by an increase in energy metabolites, especially ATP and NADH. One of the few decreasing metabolites is ADP, which, in combination with the increase in ATP, results in a large increase in ATP/ADP ratios in the β-cell with increasing glucose. Insulin secretion is dependent on ATP/ADP, resulting in glucose-stimulated insulin secretion. The observed glucose-dependent increase in glycolytic intermediates and the resulting change in ATP/ADP ratios and insulin secretion is a robust phenomenon observed across data sets, experimental systems and species. Model predictions of the glucose-dependent response of glycolytic intermediates and biphasic insulin secretion are in good agreement with experimental measurements. Our model predicts that factors affecting ATP consumption, ATP formation, hexokinase, phosphofructokinase, and ATP/ADP-dependent insulin secretion have a major effect on GSIS. In conclusion, we have developed and applied a systematic modeling workflow for pathway models that allowed us to gain insight into key mechanisms in GSIS in the pancreatic β-cell.
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Affiliation(s)
- M. Deepa Maheshvare
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore, India
| | - Soumyendu Raha
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore, India
| | - Matthias König
- Institute for Biology, Institute for Theoretical Biology, Humboldt-University Berlin, Berlin, Germany
| | - Debnath Pal
- Department of Computational and Data Sciences, Indian Institute of Science, Bangalore, India
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2
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Deepa Maheshvare M, Raha S, König M, Pal D. A Consensus Model of Glucose-Stimulated Insulin Secretion in the Pancreatic β -Cell. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.10.532028. [PMID: 36945414 PMCID: PMC10028967 DOI: 10.1101/2023.03.10.532028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/13/2023]
Abstract
The pancreas plays a critical role in maintaining glucose homeostasis through the secretion of hormones from the islets of Langerhans. Glucose-stimulated insulin secretion (GSIS) by the pancreatic β -cell is the main mechanism for reducing elevated plasma glucose. Here we present a systematic modeling workflow for the development of kinetic pathway models using the Systems Biology Markup Language (SBML). Steps include retrieval of information from databases, curation of experimental and clinical data for model calibration and validation, integration of heterogeneous data including absolute and relative measurements, unit normalization, data normalization, and model annotation. An important factor was the reproducibility and exchangeability of the model, which allowed the use of various existing tools. The workflow was applied to construct the first consensus model of GSIS in the pancreatic β -cell based on experimental and clinical data from 39 studies spanning 50 years of pancreatic, islet, and β -cell research in humans, rats, mice, and cell lines. The model consists of detailed glycolysis and equations for insulin secretion coupled to cellular energy state (ATP/ADP ratio). Key findings of our work are that in GSIS there is a glucose-dependent increase in almost all intermediates of glycolysis. This increase in glycolytic metabolites is accompanied by an increase in energy metabolites, especially ATP and NADH. One of the few decreasing metabolites is ADP, which, in combination with the increase in ATP, results in a large increase in ATP/ADP ratios in the β -cell with increasing glucose. Insulin secretion is dependent on ATP/ADP, resulting in glucose-stimulated insulin secretion. The observed glucose-dependent increase in glycolytic intermediates and the resulting change in ATP/ADP ratios and insulin secretion is a robust phenomenon observed across data sets, experimental systems and species. Model predictions of the glucose-dependent response of glycolytic intermediates and insulin secretion are in good agreement with experimental measurements. Our model predicts that factors affecting ATP consumption, ATP formation, hexokinase, phosphofructokinase, and ATP/ADP-dependent insulin secretion have a major effect on GSIS. In conclusion, we have developed and applied a systematic modeling workflow for pathway models that allowed us to gain insight into key mechanisms in GSIS in the pancreatic β -cell.
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3
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Chen B, Du YR, Zhu H, Sun ML, Wang C, Cheng Y, Pang H, Ding G, Gao J, Tan Y, Tong X, Lv P, Zhou F, Zhan Q, Xu ZM, Wang L, Luo D, Ye Y, Jin L, Zhang S, Zhu Y, Lin X, Wu Y, Jin L, Zhou Y, Yan C, Sheng J, Flatt PR, Xu GL, Huang H. Maternal inheritance of glucose intolerance via oocyte TET3 insufficiency. Nature 2022; 605:761-766. [PMID: 35585240 DOI: 10.1038/s41586-022-04756-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 04/12/2022] [Indexed: 02/05/2023]
Abstract
Diabetes mellitus is prevalent among women of reproductive age, and many women are left undiagnosed or untreated1. Gestational diabetes has profound and enduring effects on the long-term health of the offspring2,3. However, the link between pregestational diabetes and disease risk into adulthood in the next generation has not been sufficiently investigated. Here we show that pregestational hyperglycaemia renders the offspring more vulnerable to glucose intolerance. The expression of TET3 dioxygenase, responsible for 5-methylcytosine oxidation and DNA demethylation in the zygote4, is reduced in oocytes from a mouse model of hyperglycaemia (HG mice) and humans with diabetes. Insufficient demethylation by oocyte TET3 contributes to hypermethylation at the paternal alleles of several insulin secretion genes, including the glucokinase gene (Gck), that persists from zygote to adult, promoting impaired glucose homeostasis largely owing to the defect in glucose-stimulated insulin secretion. Consistent with these findings, mouse progenies derived from the oocytes of maternal heterozygous and homozygous Tet3 deletion display glucose intolerance and epigenetic abnormalities similar to those from the oocytes of HG mice. Moreover, the expression of exogenous Tet3 mRNA in oocytes from HG mice ameliorates the maternal effect in offspring. Thus, our observations suggest an environment-sensitive window in oocyte development that confers predisposition to glucose intolerance in the next generation through TET3 insufficiency rather than through a direct perturbation of the oocyte epigenome. This finding suggests a potential benefit of pre-conception interventions in mothers to protect the health of offspring.
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Affiliation(s)
- Bin Chen
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China.,State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Ya-Rui Du
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Hong Zhu
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Mei-Ling Sun
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Chao Wang
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yi Cheng
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Haiyan Pang
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Guolian Ding
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Juan Gao
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Yajing Tan
- Shanghai Key Laboratory of Embryo Original Diseases, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaomei Tong
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Pingping Lv
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Feng Zhou
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Qitao Zhan
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhi-Mei Xu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Li Wang
- Shanghai Key Laboratory of Embryo Original Diseases, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Donghao Luo
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Yinghui Ye
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Li Jin
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Songying Zhang
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Yimin Zhu
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaona Lin
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Key Laboratory of Reproductive Dysfunction Management of Zhejiang Province, Hangzhou, China
| | - Yanting Wu
- Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China.,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China
| | - Luyang Jin
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yin Zhou
- Center for Reproductive Medicine, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Caochong Yan
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jianzhong Sheng
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Peter R Flatt
- Centre for Diabetes Research, School of Biomedical Sciences, Ulster University, Coleraine, UK
| | - Guo-Liang Xu
- State Key Laboratory of Molecular Biology, Shanghai Key Laboratory of Molecular Andrology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China. .,Shanghai Key Laboratory of Medical Epigenetics, Laboratory of Cancer Epigenetics, Institutes of Biomedical Sciences, Medical College of Fudan University, Chinese Academy of Medical Sciences (RU069), Shanghai, China.
| | - Hefeng Huang
- Key Laboratory of Reproductive Genetics (Ministry of Education), Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, China. .,Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai, China. .,Research Units of Embryo Original Diseases, Chinese Academy of Medical Sciences, Shanghai, China. .,Shanghai Key Laboratory of Embryo Original Diseases, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
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A therapeutic convection-enhanced macroencapsulation device for enhancing β cell viability and insulin secretion. Proc Natl Acad Sci U S A 2021; 118:2101258118. [PMID: 34504013 PMCID: PMC8449352 DOI: 10.1073/pnas.2101258118] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/22/2021] [Indexed: 12/30/2022] Open
Abstract
Islet transplantation for type 1 diabetes treatment has been limited by the need for lifelong immunosuppression regimens. This challenge has prompted the development of macroencapsulation devices (MEDs) to immunoprotect the transplanted islets. While promising, conventional MEDs are faced with insufficient transport of oxygen, glucose, and insulin because of the reliance on passive diffusion. Hence, these devices are constrained to two-dimensional, wafer-like geometries with limited loading capacity to maintain cells within a distance of passive diffusion. We hypothesized that convective nutrient transport could extend the loading capacity while also promoting cell viability, rapid glucose equilibration, and the physiological levels of insulin secretion. Here, we showed that convective transport improves nutrient delivery throughout the device and affords a three-dimensional capsule geometry that encapsulates 9.7-fold-more cells than conventional MEDs. Transplantation of a convection-enhanced MED (ceMED) containing insulin-secreting β cells into immunocompetent, hyperglycemic rats demonstrated a rapid, vascular-independent, and glucose-stimulated insulin response, resulting in early amelioration of hyperglycemia, improved glucose tolerance, and reduced fibrosis. Finally, to address potential translational barriers, we outlined future steps necessary to optimize the ceMED design for long-term efficacy and clinical utility.
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Gerber KM, Whitticar NB, Rochester DR, Corbin KL, Koch WJ, Nunemaker CS. The Capacity to Secrete Insulin Is Dose-Dependent to Extremely High Glucose Concentrations: A Key Role for Adenylyl Cyclase. Metabolites 2021; 11:metabo11060401. [PMID: 34205432 PMCID: PMC8235240 DOI: 10.3390/metabo11060401] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/16/2021] [Accepted: 06/18/2021] [Indexed: 12/12/2022] Open
Abstract
Insulin secretion is widely thought to be maximally stimulated in glucose concentrations of 16.7-to-30 mM (300-to-540 mg/dL). However, insulin secretion is seldom tested in hyperglycemia exceeding these levels despite the Guinness World Record being 147.6 mM (2656 mg/dL). We investigated how islets respond to 1-h exposure to glucose approaching this record. Insulin secretion from human islets at 12 mM glucose intervals dose-dependently increased until at least 72 mM glucose. Murine islets in 84 mM glucose secreted nearly double the insulin as in 24 mM (p < 0.001). Intracellular calcium was maximally stimulated in 24 mM glucose despite a further doubling of insulin secretion in higher glucose, implying that insulin secretion above 24 mM occurs through amplifying pathway(s). Increased osmolarity of 425-mOsm had no effect on insulin secretion (1-h exposure) or viability (48-h exposure) in murine islets. Murine islets in 24 mM glucose treated with a glucokinase activator secreted as much insulin as islets in 84 mM glucose, indicating that glycolytic capacity exists above 24 mM. Using an incretin mimetic and an adenylyl cyclase activator in 24 mM glucose enhanced insulin secretion above that observed in 84 mM glucose while adenylyl cyclase inhibitor reduced stimulatory effects. These results highlight the underestimated ability of islets to secrete insulin proportionally to extreme hyperglycemia through adenylyl cyclase activity.
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Affiliation(s)
- Katherine M. Gerber
- Translational Health, Honors Tutorial College, Ohio University, Athens, OH 45701, USA;
| | - Nicholas B. Whitticar
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
- Translational Biomedical Sciences Program, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Daniel R. Rochester
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
| | - Kathryn L. Corbin
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
| | - William J. Koch
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
- Translational Biomedical Sciences Program, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
| | - Craig S. Nunemaker
- Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA; (N.B.W.); (D.R.R.); (K.L.C.); (W.J.K.)
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH 45701, USA
- Correspondence: ; Tel.: +740-593-2387
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Excessive Iron Induces Oxidative Stress Promoting Cellular Perturbations and Insulin Secretory Dysfunction in MIN6 Beta Cells. Cells 2021; 10:cells10051141. [PMID: 34065122 PMCID: PMC8151797 DOI: 10.3390/cells10051141] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 12/25/2022] Open
Abstract
Exposure to high levels of glucose and iron are co-related to reactive oxygen species (ROS) generation and dysregulation of insulin synthesis and secretion, although the precise mechanisms are not well clarified. The focus of this study was to examine the consequences of exposure to high iron levels on MIN6 β-cells. MIN6 pseudoislets were exposed to 20 µM (control) or 100 µM (high) iron at predefined glucose levels (5.5 mM and 11 mM) at various time points (3, 24, 48, and 72 h). Total iron content was estimated by a colourimetric FerroZine™ assay in presence or absence of transferrin-bound iron. Cell viability was assessed by a resazurin dye-based assay, and ROS-mediated cellular oxidative stress was assessed by estimating malondialdehyde levels. β-cell iron absorption was determined by a ferritin immunoassay. Cellular insulin release and content was measured by an insulin immunoassay. Expression of SNAP-25, a key protein in the core SNARE complex that modulates vesicle exocytosis, was measured by immunoblotting. Our results demonstrate that exposure to high iron levels resulted in a 15-fold (48 h) and 4-fold (72 h) increase in cellular iron accumulation. These observations were consistent with data from oxidative stress analysis which demonstrated 2.7-fold higher levels of lipid peroxidation. Furthermore, exposure to supraphysiological (11 mM) levels of glucose and high iron (100 µM) at 72 h exerted the most detrimental effect on the MIN6 β-cell viability. The effect of high iron exposure on total cellular iron content was identical in the presence or absence of transferrin. High iron exposure (100 µM) resulted in a decrease of MIN6 insulin secretion (64% reduction) as well as cellular insulin content (10% reduction). Finally, a significant reduction in MIN6 β-cell SNAP-25 protein expression was evident at 48 h upon exposure to 100 µM iron. Our data suggest that exposure to high iron and glucose concentrations results in cellular oxidative damage and may initiate insulin secretory dysfunction in pancreatic β-cells by modulation of the exocytotic machinery.
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Gil-Rivera M, Medina-Gali RM, Martínez-Pinna J, Soriano S. Physiology of pancreatic β-cells: Ion channels and molecular mechanisms implicated in stimulus-secretion coupling. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 359:287-323. [PMID: 33832651 DOI: 10.1016/bs.ircmb.2021.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The human and mouse islet of Langerhans is an endocrine organ composed of five different cells types; insulin-secreting β-cells, glucagon-producing α-cells, somatostatin-producing δ-cells, pancreatic polypeptide-secreting PP cells and ɛ-cells that secretes ghrelin. The most important cells are the pancreatic β-cells that comprise around 45-50% of human islets and 75-80% in the mouse. Pancreatic β-cells secrete insulin at high glucose concentration, thereby finely regulating glycaemia by the hypoglycaemic effects of this hormone. Different ion channels are implicated in the stimulus-secretion coupling of insulin. An increase in the intracellular ATP concentration leads to closure KATP channels, depolarizing the cell and opening voltage-gated calcium channels. The increase of intracellular calcium concentration induced by calcium entry through voltage-gated calcium channels promotes insulin secretion. Here, we briefly describe the diversity of ion channels present in pancreatic β-cells and the different mechanisms that are responsible to induce insulin secretion in human and mouse cells. Moreover, we described the pathophysiology due to alterations in the physiology of the main ion channels present in pancreatic β-cell and its implication to predispose metabolic disorders as type 2 diabetes mellitus.
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Affiliation(s)
- Minerva Gil-Rivera
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain.
| | - Regla M Medina-Gali
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain; Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, Elche, Spain
| | - Juan Martínez-Pinna
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain; Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, Elche, Spain
| | - Sergi Soriano
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain; Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, Elche, Spain.
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8
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Grewal AS, Lather V, Charaya N, Sharma N, Singh S, Kairys V. Recent Developments in Medicinal Chemistry of Allosteric Activators of Human Glucokinase for Type 2 Diabetes Mellitus Therapeutics. Curr Pharm Des 2020; 26:2510-2552. [PMID: 32286938 DOI: 10.2174/1381612826666200414163148] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 04/07/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Glucokinase (GK), a cytoplasmic enzyme catalyzes the metabolism of glucose to glucose- 6-phosphate with the help of ATP and aids in the controlling of blood glucose levels within the normal range in humans. In pancreatic β-cells, it plays a chief role by controlling the glucose-stimulated secretion of insulin and in liver hepatocyte cells, it controls the metabolism of carbohydrates. GK acts as a promising drug target for the pharmacological treatment of patients with type 2 diabetes mellitus (T2DM) as it plays an important role in the control of carbohydrate metabolism. METHODS Data used for this review was based on the search from several science databases as well as various patent databases. The main data search terms used were allosteric GK activators, diabetes mellitus, type 2 diabetes, glucokinase, glucokinase activators and human glucokinase. RESULTS This article discusses an overview of T2DM, the biology of GK, the role of GK in T2DM, recent updates in the development of small molecule GK activators reported in recent literature, mechanism of action of GK activators and their clinical status. CONCLUSION GK activators are the novel class of pharmacological agents that enhance the catalytic activity of GK enzyme and display their antihyperglycemic effects. Broad diversity of chemical entities including benzamide analogues, carboxamides, acrylamides, benzimidazoles, quinazolines, thiazoles, pyrimidines, pyridines, orotic acid amides, amino acid derivatives, amino phosphates and urea derivatives have been synthesized in past two decades as potent allosteric activators of GK. Presently, the pharmaceutical companies and researchers are focusing on the design and development of liver-selective GK activators for preventing the possible adverse effects associated with GK activators for the long-term treatment of T2DM.
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Affiliation(s)
- Ajmer S Grewal
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Viney Lather
- Amity Institute of Pharmacy, Amity University, Noida, Uttar Pradesh, India
| | - Neha Charaya
- Jan Nayak Ch. Devi Lal Memorial College of Pharmacy, Haryana, India
| | - Neelam Sharma
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Sukhbir Singh
- Chitkara College of Pharmacy, Chitkara University, Punjab, India
| | - Visvaldas Kairys
- Department of Bioinformatics, Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
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9
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Nagy L, Béke F, Juhász L, Kovács T, Juhász-Tóth É, Docsa T, Tóth A, Gergely P, Somsák L, Bai P. Glycogen phosphorylase inhibitor, 2,3-bis[(2E)-3-(4-hydroxyphenyl)prop-2-enamido] butanedioic acid (BF142), improves baseline insulin secretion of MIN6 insulinoma cells. PLoS One 2020; 15:e0236081. [PMID: 32960890 PMCID: PMC7508380 DOI: 10.1371/journal.pone.0236081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 06/30/2020] [Indexed: 12/17/2022] Open
Abstract
Type 2 diabetes mellitus (T2DM), one of the most common metabolic diseases, is characterized by insulin resistance and inadequate insulin secretion of β cells. Glycogen phosphorylase (GP) is the key enzyme in glycogen breakdown, and contributes to hepatic glucose production during fasting or during insulin resistance. Pharmacological GP inhibitors are potential glucose lowering agents, which may be used in T2DM therapy. A natural product isolated from the cultured broth of the fungal strain No. 138354, called 2,3-bis(4-hydroxycinnamoyloxy)glutaric acid (FR258900), was discovered a decade ago. In vivo studies showed that FR258900 significantly reduced blood glucose levels in diabetic mice. We previously showed that GP inhibitors can potently enhance the function of β cells. The purpose of this study was to assess whether an analogue of FR258900 can influence β cell function. BF142 (Meso-Dimethyl 2,3-bis[(E)-3-(4-acetoxyphenyl)prop-2-enamido]butanedioate) treatment activated the glucose-stimulated insulin secretion pathway, as indicated by enhanced glycolysis, increased mitochondrial oxidation, significantly increased ATP production, and elevated calcium influx in MIN6 cells. Furthermore, BF142 induced mTORC1-specific phosphorylation of S6K, increased levels of PDX1 and insulin protein, and increased insulin secretion. Our data suggest that BF142 can influence β cell function and can support the insulin producing ability of β cells.
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Affiliation(s)
- Lilla Nagy
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Ferenc Béke
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - László Juhász
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Tünde Kovács
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Éva Juhász-Tóth
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Tibor Docsa
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Attila Tóth
- Department of Cardiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Pál Gergely
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Somsák
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Péter Bai
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- MTA-DE Lendület Laboratory of Cellular Metabolism, Debrecen, Hungary
- Research Center for Molecular Medicine, University of Debrecen, Debrecen, Hungary
- * E-mail:
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10
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Hinklin RJ, Baer BR, Boyd SA, Chicarelli MD, Condroski KR, DeWolf WE, Fischer J, Frank M, Hingorani GP, Lee PA, Neitzel NA, Pratt SA, Singh A, Sullivan FX, Turner T, Voegtli WC, Wallace EM, Williams L, Aicher TD. Discovery and preclinical development of AR453588 as an anti-diabetic glucokinase activator. Bioorg Med Chem 2020; 28:115232. [PMID: 31818630 DOI: 10.1016/j.bmc.2019.115232] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 11/14/2019] [Accepted: 11/20/2019] [Indexed: 11/29/2022]
Abstract
Glucose flux through glucokinase (GK) controls insulin release from the pancreas in response to high levels of glucose. Flux through GK is also responsible for reducing hepatic glucose output. Since many individuals with type 2 diabetes appear to have an inadequacy or defect in one or both of these processes, identifying compounds that can activate GK could provide a therapeutic benefit. Herein we report the further structure activity studies of a novel series of glucokinase activators (GKA). These studies led to the identification of pyridine 72 as a potent GKA that lowered post-prandial glucose in normal C57BL/6J mice, and after 14d dosing in ob/ob mice.
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Affiliation(s)
- Ronald J Hinklin
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States.
| | - Brian R Baer
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Steven A Boyd
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Mark D Chicarelli
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Kevin R Condroski
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Walter E DeWolf
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - John Fischer
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Michele Frank
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Gary P Hingorani
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Patrice A Lee
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | | | - Scott A Pratt
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Ajay Singh
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | | | - Timothy Turner
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Walter C Voegtli
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Eli M Wallace
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Lance Williams
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
| | - Thomas D Aicher
- Array BioPharma Inc., 3200 Walnut St., Boulder, CO 80301, United States
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11
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Association of common gene variants in glucokinase regulatory protein with cardiorenal disease: A systematic review and meta-analysis. PLoS One 2018; 13:e0206174. [PMID: 30352097 PMCID: PMC6198948 DOI: 10.1371/journal.pone.0206174] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/08/2018] [Indexed: 12/22/2022] Open
Abstract
Background Small-molecules that disrupt the binding between glucokinase and glucokinase regulatory protein (GKRP) in the liver represent a potential new class of glucose-lowering drugs. It will, however, take years before their effects on clinically relevant cardiovascular endpoints are known. The purpose of this study was to estimate the effects of these drugs on cardiorenal outcomes by studying variants in the GKRP gene (GCKR) that mimic glucokinase-GKRP disruptors. Methods The MEDLINE and EMBASE databases were searched for studies reporting on the association between GCKR variants (rs1260326, rs780094, and rs780093) and coronary artery disease (CAD), estimated glomerular filtration rate (eGFR), and chronic kidney disease (CKD). Results In total 5 CAD studies (n = 274,625 individuals), 7 eGFR studies (n = 195,195 individuals), and 4 CKD studies (n = 31,642 cases and n = 408,432 controls) were included. Meta-analysis revealed a significant association between GCKR variants and CAD (OR:1.02 per risk allele, 95%CI:1.00–1.04, p = 0.01). Sensitivity analyses showed that replacement of one large, influential CAD study by two other, partly overlapping studies resulted in similar point estimates, albeit less precise (OR:1.02; 95%CI:0.98–1.06 and OR: 1.02; 95%CI: 0.99–1.04). GCKR was associated with an improved eGFR (+0.49 ml/min, 95%CI:0.10–0.89, p = 0.01) and a trend towards protection from CKD (OR:0.98, 95%CI:0.95–1.01, p = 0.13). Conclusion This study suggests that increased glucokinase-GKRP disruption has beneficial effects on eGFR, but these may be offset by a disadvantageous effect on coronary artery disease risk. Further studies are warranted to elucidate the mechanistic link between hepatic glucose metabolism and eGFR.
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12
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Namekawa J, Yasui M, Katayanagi A, Shirai M, Asai F. Increased hepatic triglyceride level induced by a glucokinase activator in mice. ACTA ACUST UNITED AC 2018. [DOI: 10.2131/fts.5.13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Junichi Namekawa
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Azabu University
- Teijin Pharma Limited
| | | | | | - Mitsuyuki Shirai
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Azabu University
| | - Fumitoshi Asai
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Azabu University
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13
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Rorsman P, Ashcroft FM. Pancreatic β-Cell Electrical Activity and Insulin Secretion: Of Mice and Men. Physiol Rev 2018; 98:117-214. [PMID: 29212789 PMCID: PMC5866358 DOI: 10.1152/physrev.00008.2017] [Citation(s) in RCA: 424] [Impact Index Per Article: 70.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/30/2017] [Accepted: 06/18/2017] [Indexed: 12/14/2022] Open
Abstract
The pancreatic β-cell plays a key role in glucose homeostasis by secreting insulin, the only hormone capable of lowering the blood glucose concentration. Impaired insulin secretion results in the chronic hyperglycemia that characterizes type 2 diabetes (T2DM), which currently afflicts >450 million people worldwide. The healthy β-cell acts as a glucose sensor matching its output to the circulating glucose concentration. It does so via metabolically induced changes in electrical activity, which culminate in an increase in the cytoplasmic Ca2+ concentration and initiation of Ca2+-dependent exocytosis of insulin-containing secretory granules. Here, we review recent advances in our understanding of the β-cell transcriptome, electrical activity, and insulin exocytosis. We highlight salient differences between mouse and human β-cells, provide models of how the different ion channels contribute to their electrical activity and insulin secretion, and conclude by discussing how these processes become perturbed in T2DM.
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Affiliation(s)
- Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom; Department of Neuroscience and Physiology, Metabolic Research Unit, Göteborg, Sweden; and Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Frances M Ashcroft
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom; Department of Neuroscience and Physiology, Metabolic Research Unit, Göteborg, Sweden; and Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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14
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Jeffery N, Richardson S, Beall C, Harries LW. The species origin of the cellular microenvironment influences markers of beta cell fate and function in EndoC-βH1 cells. Exp Cell Res 2017; 361:284-291. [PMID: 29107069 DOI: 10.1016/j.yexcr.2017.10.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 10/24/2017] [Accepted: 10/25/2017] [Indexed: 12/30/2022]
Abstract
Interaction between islet cell subtypes and the extracellular matrix influences beta-cell function in mammals. The tissue architecture of rodent islets is very different to that of human islets; cell-to-cell communication and interaction with the extracellular matrix may vary between species. In this work, we have compared the responses of the human EndoC-βH1 cell line to non-human and human-derived growth matrices in terms of growth morphology, gene expression and glucose-stimulated insulin secretion (GSIS). EndoC-βH1 cells demonstrated a greater tendency to form cell clusters when cultured in a human microenvironment and exhibited reduced alpha cell markers at the mRNA level; mean expression difference - 0.23 and - 0.51; p = 0.009 and 0.002 for the Aristaless-related homeobox (ARX) and Glucagon (GCG) genes respectively. No differences were noted in the protein expression of mature beta cell markers such as Pdx1 and NeuroD1 were noted in EndoC-βH1 cells grown in a human microenvironment but cells were however more sensitive to glucose (4.3-fold increase in insulin secretion following glucose challenge compared with a 1.9-fold increase in cells grown in a non-human microenvironment; p = 0.0003). Our data suggests that the tissue origin of the cellular microenvironment has effects on the function of EndoC-βH1 cells in vitro, and the use of a more human-like culture microenvironment may bring benefits in terms of increased physiological relevance.
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Affiliation(s)
- N Jeffery
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Devon EX2 5DW, UK
| | - S Richardson
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Devon EX2 5DW, UK
| | - C Beall
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Devon EX2 5DW, UK
| | - L W Harries
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Devon EX2 5DW, UK.
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15
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Shao X, Tang Y, Long H, Gu H, Zhang J, Deng P, Zhao Y, Cen X. HMG-CoA synthase 2 drives brain metabolic reprogramming in cocaine exposure. Neuropharmacology 2017; 148:377-393. [PMID: 28987936 DOI: 10.1016/j.neuropharm.2017.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 09/25/2017] [Accepted: 10/01/2017] [Indexed: 02/05/2023]
Abstract
The brain is a high energy-consuming organ that typically utilizes glucose as the main energy source for cerebral activity. When glucose becomes scarce under conditions of stress, ketone bodies, such as β-hydroxybutyrate, acetoacetate and acetone, become extremely important. Alterations in brain energy metabolism have been observed in psychostimulant abusers; however, the mode of brain metabolic programming in cocaine dependence remains largely unknown. Here, we profiled the metabolites and metabolic enzymes from brain nucleus accumbens (NAc) of mice exposed to cocaine. We found that cocaine modified energy metabolism and markedly activated ketogenesis pathway in the NAc. The expression of HMG-CoA synthase 2 (HMGCS2), a critical rate-limiting ketogenesis enzyme, was markedly up-regulated. After switching metabolic pathways from ketogenesis to glycolysis through activation of glucokinase, cocaine-evoked metabolic reprogramming regained homeostasis, and the cocaine effect was attenuated. Importantly, both the pharmacological and genetic inhibition of HMGCS2 significantly suppressed cocaine-induced ketogenesis and behavior. In conclusion, cocaine induces a remarkable energy reprogramming in the NAc, which is characterized by HMGCS2-driven ketogenesis. Such effect may facilitate adaptations to cocaine-induced energy stress in the brain. Our findings establish an important link between drug-induced energy reprogramming and cocaine effect, and may have implication in the treatment of cocaine addiction.
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Affiliation(s)
- Xue Shao
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China
| | - Yunxuan Tang
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China
| | - Hailei Long
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China
| | - Hui Gu
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China
| | - Jie Zhang
- Key Laboratory of Transplant Engineering and Immunology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Pengchi Deng
- Analytical &Testing Center, Sichuan University, Chengdu 610041, China
| | - Yinglan Zhao
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China
| | - Xiaobo Cen
- National Chengdu Center for Safety Evaluation of Drugs, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Collaborative Innovation Center for Biotherapy, Chengdu 610041, PR China.
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16
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Seino S, Sugawara K, Yokoi N, Takahashi H. β-Cell signalling and insulin secretagogues: A path for improved diabetes therapy. Diabetes Obes Metab 2017; 19 Suppl 1:22-29. [PMID: 28880474 DOI: 10.1111/dom.12995] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 04/24/2017] [Accepted: 04/27/2017] [Indexed: 12/26/2022]
Abstract
Insulin secretagogues including sulfonylureas, glinides and incretin-related drugs such as dipeptidyl peptidase 4 (DPP-4) inhibitors and glucagon-like peptide-1 receptor agonists are widely used for treatment of type 2 diabetes. In addition, glucokinase activators and G-protein-coupled receptor 40 (GPR40) agonists also have been developed, although the drugs are not clinically usable. These different drugs exert their effects on insulin secretion by different mechanisms. Recent advances in β-cell signalling studies have not only deepened our understanding of insulin secretion but also revealed novel mechanisms of insulin secretagogues. Clarification of the signalling mechanisms of the insulin secretagogues will contribute to improved drug therapy for diabetes.
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Affiliation(s)
- Susumu Seino
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kenji Sugawara
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
- Division of Diabetes and Endocrinology, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Norihide Yokoi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Harumi Takahashi
- Division of Molecular and Metabolic Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
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17
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Zhang Y, Deng R, Yang X, Xu W, Liu Y, Li F, Zhang J, Tang H, Ji X, Bi Y, Wang X, Zhou L, Ning G. Glucose potentiates β-cell function by inducing Tph1 expression in rat islets. FASEB J 2017; 31:5342-5355. [PMID: 28794173 DOI: 10.1096/fj.201700351r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 07/25/2017] [Indexed: 12/19/2022]
Abstract
Impaired pancreatic β-cell function is the primary defect in type 2 diabetes. Glucose is an important regulator of β-cell growth and function; however, the mechanisms that are involved in the chronic adaptation of β cells to hyperglycemia remain largely unknown. In the present study, global gene expression patterns revealed that tryptophan hydroxylase 1 (Tph1) was the most profound of genes that are up-regulated in rat islets exposed to high glucose. Calcium and cAMP signals synergistically mediated glucose-stimulated Tph1 transcription in β cells by activating cAMP-responsive element-binding protein and promoting its binding with a Tph1 promoter. Similar to in vitro results, in vivo infusion of high glucose also strongly induced Tph1 expression and serotonin production in rat islets, along with enhanced islet function. Inhibition or knockdown of Tph1 markedly decreased glucose-potentiated insulin secretion. In contrast, overexpression of Tph1 augmented glucose-stimulated insulin secretion in rat islets by up-regulating the expression of genes that are related to islet function. In addition, the long-acting glucagon-like peptide 1 receptor agonist, exendin-4, stimulated Tph1 expression in a glucose-dependent manner. Knockdown of Tph1 inhibited exendin-4-potentiated insulin secretion in rat islets. These findings suggest that Tph1 mediates the compensation of islet function induced by glucose, and that promoting Tph1 expression in pancreatic β cells will provide a new strategy for the treatment of type 2 diabetes mellitus.-Zhang, Y., Deng, R., Yang, X., Xu, W., Liu, Y., Li, F., Zhang, J., Tang, H., Ji, X., Bi, Y., Wang, X., Zhou, L., Ning, G. Glucose potentiates β-cell function by inducing Tph1 expression in rat islets.
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Affiliation(s)
- Yuqing Zhang
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Ruyuan Deng
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xue Yang
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Wan Xu
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yun Liu
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Fengying Li
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Juan Zhang
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hongju Tang
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xueying Ji
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yufang Bi
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Xiao Wang
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Libin Zhou
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Guang Ning
- Department of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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18
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Henquin JC, Dufrane D, Gmyr V, Kerr-Conte J, Nenquin M. Pharmacological approach to understanding the control of insulin secretion in human islets. Diabetes Obes Metab 2017; 19:1061-1070. [PMID: 28116849 DOI: 10.1111/dom.12887] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 01/12/2017] [Accepted: 01/19/2017] [Indexed: 11/29/2022]
Abstract
AIMS To understand better the control of insulin secretion by human β cells and to identify similarities to and differences from rodent models. METHODS Dynamic insulin secretion was measured in perifused human islets treated with pharmacological agents of known modes of action. RESULTS Glucokinase activation (Ro28-1675) lowered the glucose threshold for stimulation of insulin secretion to 1 mmol/L (G1), augmented the response to G3-G5 but not to G8-G15, whereas tolbutamide remained active in G20, which indicates that not all KATP channels were closed by high glucose concentrations. An almost 2-fold greater response to G15 than to supramaximal tolbutamide in G3 or to KCl+diazoxide in G15 vs G3 quantified the contribution of metabolic amplification to insulin secretion. Both disruption (latrunculin-B) and stabilization (jasplakinolide) of microfilaments augmented insulin secretion without affecting metabolic amplification. Tolbutamide-induced insulin secretion was consistently greater in G10 than G3, with a threshold at 1 and maximum at 10 µmol/L tolbutamide in G10, vs 10 and 25 µmol/L in G3. Sulphonylurea effects were thus clearly glucose-dependent. Insulin secretion was also increased by inhibiting K channels other than KATP channels: Kv or BK channels (tetraethylammonium), TASK-1 channels (ML-365) and SK4 channels (TRAM-34). Opening KATP channels with diazoxide inhibited glucose-induced insulin secretion with half maximum inhibitory concentrations of 9.6 and 24 µmol/L at G7 and G15. Blockade of L-type Ca channels (nimodipine) abolished insulin secretion, whereas a blocker of T-type Ca channels (NNC-55-0396) was ineffective at specific concentrations. Blockade of Na channels (tetrodotoxin) did not affect glucose-induced insulin secretion. CONCLUSIONS In addition to sharing a KATP channel-dependent triggering pathway and a metabolic amplifying pathway, human and rodent β cells were found to display more similarities than differences in the control of insulin secretion.
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Affiliation(s)
- Jean-Claude Henquin
- Unit of Endocrinology and Metabolism, Faculty of Medicine, University of Louvain, Brussels, Belgium
| | - Denis Dufrane
- Endocrine Cell Therapy Unit, University Clinics Saint-Luc, University of Louvain, Brussels, Belgium
| | - Valery Gmyr
- Institut National de la Santé et de la Recherche Médicale U1190, Translational Research for Diabetes, and European Genomic Institute for Diabetes, University of Lille, Lille, France
| | - Julie Kerr-Conte
- Institut National de la Santé et de la Recherche Médicale U1190, Translational Research for Diabetes, and European Genomic Institute for Diabetes, University of Lille, Lille, France
| | - Myriam Nenquin
- Unit of Endocrinology and Metabolism, Faculty of Medicine, University of Louvain, Brussels, Belgium
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19
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Nagy L, Márton J, Vida A, Kis G, Bokor É, Kun S, Gönczi M, Docsa T, Tóth A, Antal M, Gergely P, Csóka B, Pacher P, Somsák L, Bai P. Glycogen phosphorylase inhibition improves beta cell function. Br J Pharmacol 2017; 175:301-319. [PMID: 28409826 DOI: 10.1111/bph.13819] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 04/03/2017] [Accepted: 04/05/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Glycogen phosphorylase (GP) is the key enzyme for glycogen degradation. GP inhibitors (GPi-s) are glucose lowering agents that cause the accumulation of glucose in the liver as glycogen. Glycogen metabolism has implications in beta cell function. Glycogen degradation can maintain cellular glucose levels, which feeds into catabolism to maintain insulin secretion, and elevated glycogen degradation levels contribute to glucotoxicity. The purpose of this study was to assess whether influencing glycogen metabolism in beta cells by GPi-s affects the function of these cells. EXPERIMENTAL APPROACH The effects of structurally different GPi-s were investigated on MIN6 insulinoma cells and in a mouse model of diabetes. KEY RESULTS GPi treatment increased glycogen content and, consequently, the surface area of glycogen in MIN6 cells. Furthermore, GPi treatment induced insulin receptor β (InsRβ), Akt and p70S6K phosphorylation, as well as pancreatic and duodenal homeobox 1(PDX1) and insulin expression. In line with these findings, GPi-s enhanced non-stimulated and glucose-stimulated insulin secretion in MIN6 cells. The InsRβ was shown to co-localize with glycogen particles as confirmed by in silico screening, where components of InsR signalling were identified as glycogen-bound proteins. GPi-s also activated the pathway of insulin secretion, indicated by enhanced glycolysis, mitochondrial oxidation and calcium signalling. Finally, GPi-s increased the size of islets of Langerhans and improved glucose-induced insulin release in mice. CONCLUSION AND IMPLICATIONS These data suggest that GPi-s also target beta cells and can be repurposed as agents to preserve beta cell function or even ameliorate beta cell dysfunction in different forms of diabetes. LINKED ARTICLES This article is part of a themed section on Inventing New Therapies Without Reinventing the Wheel: The Power of Drug Repurposing. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.2/issuetoc.
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Affiliation(s)
- Lilla Nagy
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,MTA-DE Cell Biology and Signaling Research Group, Debrecen, Hungary
| | - Judit Márton
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - András Vida
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,MTA-DE Lendület Laboratory of Cellular Metabolism, Debrecen, Hungary
| | - Gréta Kis
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Éva Bokor
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Sándor Kun
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tibor Docsa
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Attila Tóth
- Department of Cardiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Miklós Antal
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,MTA-DE Neuroscience Research Group, Debrecen, Hungary
| | - Pál Gergely
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balázs Csóka
- Department of Surgery, Rutgers - New Jersey Medical School, Newark, NJ, USA.,Center for Immunity and Inflammation, Rutgers - New Jersey Medical School, Newark, NJ, USA
| | - Pal Pacher
- NIAAA, National Institutes of Health, Laboratory of Physiologic Studies, Rockville, MD, USA
| | - László Somsák
- Department of Organic Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Péter Bai
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,MTA-DE Lendület Laboratory of Cellular Metabolism, Debrecen, Hungary.,Research Center for Molecular Medicine, University of Debrecen, Debrecen, Hungary
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20
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Yang X, Zhang Y, Xu W, Deng R, Liu Y, Li F, Wang Y, Ji X, Bai M, Zhou F, Zhou L, Wang X. Potential role of Hsp90 in rat islet function under the condition of high glucose. Acta Diabetol 2016; 53:621-8. [PMID: 26997509 DOI: 10.1007/s00592-016-0852-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 02/20/2016] [Indexed: 01/02/2023]
Abstract
AIMS The preservation of pancreatic β-cell function is a key point in the treatment of type 2 diabetes mellitus. There is substantial evidence demonstrating that heat-shock protein 90 (Hsp90) is needed for the stabilization and correct folding of client proteins and plays important roles in various biological processes. Here, we revealed the important role of Hsp90 in β-cell function. METHODS Islets from male Sprague-Dawley rats were isolated to be used for further RT-PCR, Western blot, and insulin secretion test ex vivo in response to different stimuli. RESULTS Our results revealed that Hsp90 expression was significantly decreased in isolated rat islets exposed to high glucose, which was involved in glucokinase activation and glucose metabolism, not calcium signaling. Two kinds of Hsp90 inhibitors 17-DMAG and CCT018159 markedly enhanced glucose-stimulated insulin secretion from rat islets, along with increased expressions of genes closely related to β-cell function. CONCLUSIONS These data indicate that Hsp90 may be involved in high glucose-induced islet function adaptation.
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Affiliation(s)
- Xue Yang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Yuqing Zhang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Wan Xu
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Ruyuan Deng
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Yun Liu
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Fengying Li
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Yao Wang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Xueying Ji
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Mengyao Bai
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Feiye Zhou
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China
| | - Libin Zhou
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China.
| | - Xiao Wang
- Shanghai Clinical Center for Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Department of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, 197 Ruijin Road II, Shanghai, 200025, China.
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21
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Gerencser AA, Mookerjee SA, Jastroch M, Brand MD. Measurement of the Absolute Magnitude and Time Courses of Mitochondrial Membrane Potential in Primary and Clonal Pancreatic Beta-Cells. PLoS One 2016; 11:e0159199. [PMID: 27404273 PMCID: PMC4942067 DOI: 10.1371/journal.pone.0159199] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/28/2016] [Indexed: 12/22/2022] Open
Abstract
The aim of this study was to simplify, improve and validate quantitative measurement of the mitochondrial membrane potential (ΔψM) in pancreatic β-cells. This built on our previously introduced calculation of the absolute magnitude of ΔψM in intact cells, using time-lapse imaging of the non-quench mode fluorescence of tetramethylrhodamine methyl ester and a bis-oxonol plasma membrane potential (ΔψP) indicator. ΔψM is a central mediator of glucose-stimulated insulin secretion in pancreatic β-cells. ΔψM is at the crossroads of cellular energy production and demand, therefore precise assay of its magnitude is a valuable tool to study how these processes interplay in insulin secretion. Dispersed islet cell cultures allowed cell type-specific, single-cell observations of cell-to-cell heterogeneity of ΔψM and ΔψP. Glucose addition caused hyperpolarization of ΔψM and depolarization of ΔψP. The hyperpolarization was a monophasic step increase, even in cells where the ΔψP depolarization was biphasic. The biphasic response of ΔψP was associated with a larger hyperpolarization of ΔψM than the monophasic response. Analysis of the relationships between ΔψP and ΔψM revealed that primary dispersed β-cells responded to glucose heterogeneously, driven by variable activation of energy metabolism. Sensitivity analysis of the calibration was consistent with β-cells having substantial cell-to-cell variations in amounts of mitochondria, and this was predicted not to impair the accuracy of determinations of relative changes in ΔψM and ΔψP. Finally, we demonstrate a significant problem with using an alternative ΔψM probe, rhodamine 123. In glucose-stimulated and oligomycin-inhibited β-cells the principles of the rhodamine 123 assay were breached, resulting in misleading conclusions.
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Affiliation(s)
- Akos A. Gerencser
- Buck Institute for Research on Aging, Novato, California, United States of America
- Image Analyst Software, Novato, California, United States of America
| | - Shona A. Mookerjee
- Buck Institute for Research on Aging, Novato, California, United States of America
- Touro University California College of Pharmacy, Vallejo, California, United States of America
| | - Martin Jastroch
- Buck Institute for Research on Aging, Novato, California, United States of America
| | - Martin D. Brand
- Buck Institute for Research on Aging, Novato, California, United States of America
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22
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Swartling U, Lynch K, Smith L, Johnson SB. Parental Estimation of Their Child's Increased Type 1 Diabetes Risk During the First 2 Years of Participation in an International Observational Study: Results From the TEDDY study. J Empir Res Hum Res Ethics 2016; 11:106-14. [PMID: 27241873 PMCID: PMC4917467 DOI: 10.1177/1556264616648589] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study assessed mothers' and fathers' perception of their child's risk of getting type 1 diabetes (T1D) during the first 2 years of their participation in The Environmental Determinants of Diabetes in the Young (TEDDY) study. TEDDY parents were informed of their child's increased genetic risk for T1D at study inception. Parent perception of the child's risk was assessed at 3, 6, 15, and 27 months of age. In families with no history of T1D, underestimation of the child's T1D risk was common in mothers (>38%) and more so in fathers (>50%). The analyses indicated that parental education, country of residence, family history of T1D, household crowding, ethnic minority status, and beliefs that the child's T1D risk can be reduced were factors associated with parental risk perception accuracy. Even when given extensive information about their child's T1D risk, parents often fail to accurately grasp the information provided. This is particularly true for fathers, families from low socioeconomic backgrounds, and those with no family history of T1D. It is important to develop improved tools for risk communication tailored to individual family needs.
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23
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Bronsart LL, Stokes C, Contag CH. Chemiluminescence Imaging of Superoxide Anion Detects Beta-Cell Function and Mass. PLoS One 2016; 11:e0146601. [PMID: 26752052 PMCID: PMC4709142 DOI: 10.1371/journal.pone.0146601] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 12/18/2015] [Indexed: 12/21/2022] Open
Abstract
Superoxide anion is produced during normal cellular respiration and plays key roles in cellular physiology with its dysregulation being associated with a variety of diseases. Superoxide anion is a short-lived molecule and, therefore, its homeostatic regulation and role in biology and disease requires dynamic quantification with fine temporal resolution. Here we validated coelenterazine as a reporter of intracellular superoxide anion concentration and used it as a dynamic measure both in vitro and in vivo. Chemiluminescence was dependent upon superoxide anion levels, including those produced during cellular respiration, and concentrations varied both kinetically and temporally in response to physiologically relevant fluctuations in glucose levels. In vivo imaging with coelenterazine revealed that beta cells of the pancreas have increased levels of superoxide anion, which acted as a measure of beta-cell function and mass and could predict the susceptibility of mice to diabetes mellitus. Glucose response and regulation are key elements of cellular physiology and organismal biology, and superoxide anion appears to play a fundamental and dynamic role in both of these processes.
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Affiliation(s)
- Laura L. Bronsart
- Department of Biology, Stanford University, 318 Campus Drive, Stanford, California 94305, United States of America
- Department of Pediatrics, Stanford University, 318 Campus Drive, Stanford, California 94305, United States of America
| | - Christian Stokes
- Department of Pediatrics, Stanford University, 318 Campus Drive, Stanford, California 94305, United States of America
| | - Christopher H. Contag
- Department of Pediatrics, Stanford University, 318 Campus Drive, Stanford, California 94305, United States of America
- Departments of Radiology, Microbiology & Immunology, Stanford University, 318 Campus Drive, Stanford, California 94305, United States of America
- * E-mail:
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24
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Fjellström O, Larsson N, Yasuda SI, Tsuchida T, Oguma T, Marley A, Wennberg-Huldt C, Hovdal D, Fukuda H, Yoneyama Y, Sasaki K, Johansson A, Lundqvist S, Brengdahl J, Isaacs RJ, Brown D, Geschwindner S, Benthem L, Priest C, Turnbull A. Novel Zn2+ Modulated GPR39 Receptor Agonists Do Not Drive Acute Insulin Secretion in Rodents. PLoS One 2015; 10:e0145849. [PMID: 26720709 PMCID: PMC4697807 DOI: 10.1371/journal.pone.0145849] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 12/09/2015] [Indexed: 12/24/2022] Open
Abstract
Type 2 diabetes (T2D) occurs when there is insufficient insulin release to control blood glucose, due to insulin resistance and impaired β-cell function. The GPR39 receptor is expressed in metabolic tissues including pancreatic β-cells and has been proposed as a T2D target. Specifically, GPR39 agonists might improve β-cell function leading to more adequate and sustained insulin release and glucose control. The present study aimed to test the hypothesis that GPR39 agonism would improve glucose stimulated insulin secretion in vivo. A high throughput screen, followed by a medicinal chemistry program, identified three novel potent Zn2+ modulated GPR39 agonists. These agonists were evaluated in acute rodent glucose tolerance tests. The results showed a lack of glucose lowering and insulinotropic effects not only in lean mice, but also in diet-induced obese (DIO) mice and Zucker fatty rats. It is concluded that Zn2+ modulated GPR39 agonists do not acutely stimulate insulin release in rodents.
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Affiliation(s)
- Ola Fjellström
- Medicinal Chemistry CVMD iMed, AstraZeneca R&D Gothenburg, Mölndal, Sweden
- * E-mail:
| | - Niklas Larsson
- Discovery Sciences, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Shin-ichiro Yasuda
- Pharmacology Research Laboratories II, Mitsubishi Tanabe Pharma Corporation, Kawagishi, Toda-shi, Saitama, Japan
| | - Takuma Tsuchida
- Pharmacology Research Laboratories II, Mitsubishi Tanabe Pharma Corporation, Kawagishi, Toda-shi, Saitama, Japan
| | - Takahiro Oguma
- Pharmacology Research Laboratories II, Mitsubishi Tanabe Pharma Corporation, Kawagishi, Toda-shi, Saitama, Japan
| | - Anna Marley
- Discovery Sciences, AstraZeneca R&D, Mereside, United Kingdom
| | | | - Daniel Hovdal
- DMPK CVMD iMed, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Hajime Fukuda
- DMPK Research Laboratories, Mitsubishi Tanabe Pharma Corporation, Kawagishi, Toda-shi, Saitama, Japan
| | - Yukimi Yoneyama
- DMPK Research Laboratories, Mitsubishi Tanabe Pharma Corporation, Kawagishi, Toda-shi, Saitama, Japan
| | - Kazuyo Sasaki
- Pharmacology Research Laboratories II, Mitsubishi Tanabe Pharma Corporation, Kawagishi, Toda-shi, Saitama, Japan
| | - Anders Johansson
- Medicinal Chemistry CVMD iMed, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Sara Lundqvist
- Discovery Sciences, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Johan Brengdahl
- Discovery Sciences, AstraZeneca R&D Gothenburg, Mölndal, Sweden
| | - Richard J. Isaacs
- Molecular Sensing, Inc., Nashville, Tennessee, United States of America
| | - Daniel Brown
- Molecular Sensing, Inc., Nashville, Tennessee, United States of America
| | | | | | - Claire Priest
- Discovery Sciences, AstraZeneca R&D, Mereside, United Kingdom
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25
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Lei L, Liu Q, Liu S, Huan Y, Sun S, Chen Z, Li L, Feng Z, Li Y, Shen Z. Antidiabetic potential of a novel dual-target activator of glucokinase and peroxisome proliferator activated receptor-γ. Metabolism 2015; 64:1250-61. [PMID: 26189598 DOI: 10.1016/j.metabol.2015.06.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 06/17/2015] [Accepted: 06/18/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND AND PURPOSE Glucokinase (GK) balances blood glucose levels via regulation of glucose metabolism and insulin secretion. Peroxisome proliferator activated receptor-γ (PPARγ) regulates gene expression in glucose and lipid metabolism. In this study, we investigated the therapeutic effect of a novel compound, SHP289-03, which activates both GK and PPARγ. METHODS Glucose metabolism was tested in primary hepatocytes of normal ICR mice, and insulin secretion was measured in NIT-1 insulinoma cells as well as in primary islets of normal ICR mice. The in vivo pharmacodynamics of SHP289-03 was assessed using the spontaneous type 2 diabetic mouse model, KKA(y). KEY RESULTS In hepatocytes, SHP289-03 promoted glucose consumption. In NIT-1 cells, it increased the concentration of intracellular ATP and calcium, and subsequently enhanced glucose-stimulated insulin secretion in both NIT-1 cells and primary islets. Moreover, SHP289-03 decreased the blood glucose level, improved glucose tolerance and reduced blood lipid levels in KKA(y) mice. It restored islet morphology and increased the beta cell/alpha cell mass ratio, in addition to up-regulating GK gene expression in the liver of KKA(y) mice. DISCUSSION AND CONCLUSIONS SHP289-03 has significant therapeutic potential for the treatment of diabetes mellitus.
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Affiliation(s)
- Lei Lei
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China
| | - Quan Liu
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China
| | - Shuainan Liu
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China
| | - Yi Huan
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China
| | - Sujuan Sun
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China
| | - Zhiyu Chen
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China
| | - Linyi Li
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China
| | - Zhiqiang Feng
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China
| | - Yan Li
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China
| | - Zhufang Shen
- The State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R. China.
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26
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Zhong L, Yeh TYJ, Hao J, Pourtabatabaei N, Mahata SK, Shao J, Chessler SD, Chi NW. Nutritional energy stimulates NAD+ production to promote tankyrase-mediated PARsylation in insulinoma cells. PLoS One 2015; 10:e0122948. [PMID: 25876076 PMCID: PMC4395342 DOI: 10.1371/journal.pone.0122948] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 02/16/2015] [Indexed: 02/06/2023] Open
Abstract
The poly-ADP-ribosylation (PARsylation) activity of tankyrase (TNKS) regulates diverse physiological processes including energy metabolism and wnt/β-catenin signaling. This TNKS activity uses NAD+ as a co-substrate to post-translationally modify various acceptor proteins including TNKS itself. PARsylation by TNKS often tags the acceptors for ubiquitination and proteasomal degradation. Whether this TNKS activity is regulated by physiological changes in NAD+ levels or, more broadly, in cellular energy charge has not been investigated. Because the NAD+ biosynthetic enzyme nicotinamide phosphoribosyltransferase (NAMPT) in vitro is robustly potentiated by ATP, we hypothesized that nutritional energy might stimulate cellular NAMPT to produce NAD+ and thereby augment TNKS catalysis. Using insulin-secreting cells as a model, we showed that glucose indeed stimulates the autoPARsylation of TNKS and consequently its turnover by the ubiquitin-proteasomal system. This glucose effect on TNKS is mediated primarily by NAD+ since it is mirrored by the NAD+ precursor nicotinamide mononucleotide (NMN), and is blunted by the NAMPT inhibitor FK866. The TNKS-destabilizing effect of glucose is shared by other metabolic fuels including pyruvate and amino acids. NAD+ flux analysis showed that glucose and nutrients, by increasing ATP, stimulate NAMPT-mediated NAD+ production to expand NAD+ stores. Collectively our data uncover a metabolic pathway whereby nutritional energy augments NAD+ production to drive the PARsylating activity of TNKS, leading to autoPARsylation-dependent degradation of the TNKS protein. The modulation of TNKS catalytic activity and protein abundance by cellular energy charge could potentially impose a nutritional control on the many processes that TNKS regulates through PARsylation. More broadly, the stimulation of NAD+ production by ATP suggests that nutritional energy may enhance the functions of other NAD+-driven enzymes including sirtuins.
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Affiliation(s)
- Linlin Zhong
- Research Service, VA San Diego Healthcare System, San Diego, CA 92161, United States of America
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, United States of America
| | - Tsung-Yin J. Yeh
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, United States of America
| | - Jun Hao
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, United States of America
- Department of Pathology, Hebei Medical University, Shijiazhuang, China
| | - Nasim Pourtabatabaei
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, United States of America
| | - Sushil K. Mahata
- Research Service, VA San Diego Healthcare System, San Diego, CA 92161, United States of America
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, United States of America
| | - Jianhua Shao
- Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, United States of America
| | - Steven D. Chessler
- Department of Medicine, University of California Irvine, Irvine, CA 92697, United States of America
| | - Nai-Wen Chi
- Research Service, VA San Diego Healthcare System, San Diego, CA 92161, United States of America
- Department of Medicine, University of California San Diego, La Jolla, CA 92093, United States of America
- * E-mail:
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Raimondo A, Rees MG, Gloyn AL. Glucokinase regulatory protein: complexity at the crossroads of triglyceride and glucose metabolism. Curr Opin Lipidol 2015; 26:88-95. [PMID: 25692341 PMCID: PMC4422901 DOI: 10.1097/mol.0000000000000155] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
PURPOSE OF REVIEW Glucokinase regulator (GCKR) encodes glucokinase regulatory protein (GKRP), a hepatocyte-specific inhibitor of the glucose-metabolizing enzyme glucokinase (GCK). Genome-wide association studies have identified a common coding variant within GCKR associated with multiple metabolic traits. This review focuses on recent insights into the critical role of GKRP in hepatic glucose metabolism that have stemmed from the study of human genetics. This knowledge has improved our understanding of glucose and lipid physiology and informed the development of targeted molecular therapeutics for diabetes. RECENT FINDINGS Rare GCKR variants have effects on GKRP expression, localization, and activity. These variants are collectively associated with hypertriglyceridaemia but are not causal. Crystal structures of GKRP and the GCK-GKRP complex have been solved, providing greater insight into the molecular interactions between these proteins. Finally, small molecules have been identified that directly bind GKRP and reduce blood glucose levels in rodent models of diabetes. SUMMARY GCKR variants across the allelic spectrum have effects on glucose and lipid homeostasis. Functional analysis has highlighted numerous molecular mechanisms for GKRP dysfunction. Hepatocyte-specific GCK activation via small molecule GKRP inhibition may be a new avenue for type 2 diabetes treatment, particularly considering evidence indicating GKRP loss-of-function alone does not cause hypertriglyceridaemia.
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Affiliation(s)
- Anne Raimondo
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - Matthew G. Rees
- Center for the Science of Therapeutics, Broad Institute, Cambridge, Massachusetts, USA
- Howard Hughes Medical Institute, Broad Institute, Cambridge, Massachusetts, USA
| | - Anna L. Gloyn
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, ORH Trust, OCDEM, Churchill Hospital, Oxford, UK
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28
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Park K, Lee BM, Hyun KH, Han T, Lee DH, Choi HH. Design and Synthesis of Acetylenyl Benzamide Derivatives as Novel Glucokinase Activators for the Treatment of T2DM. ACS Med Chem Lett 2015; 6:296-301. [PMID: 25815149 DOI: 10.1021/ml5004712] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/14/2015] [Indexed: 01/08/2023] Open
Abstract
Novel acetylenyl-containing benzamide derivatives were synthesized and screened using an in vitro assay measuring increases in glucokinase activity stimulated by 10 mM glucose concentration and glucose uptake in rat hepatocytes. Lead optimization of an acetylenyl benzamide series led to the discovery of several active compounds via in vitro enzyme assays (EC50 < 40 nM) and in vivo OGTT assays (AUC reduction > 40% at 50 mg/kg). Of the active compounds tested, 3-(3-amino-phenylethynyl)-5-(2-methoxy-1-methyl-ethoxy)-N-(1-methyl-1H-pyrazol-3-yl)-benzamide (19) was identified as a potent glucokinase activator exhibiting an EC50 of 27 nM and eliciting a 2.16-fold increase in glucose uptake. Compound 19 caused a glucose AUC reduction of 47.4% (30 mg/kg) in an OGTT study in C57BL/6J mice compared to 22.6% for sitagliptin (30 mg/kg). Single treatment of the compound 19 in C57BL/6J mice elicited basal glucose lowering activity without any significant evidence for hypoglycemia risk. Compound 19 was therefore selected as a candidate for further preclinical development for the treatment of type 2 diabetes.
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Affiliation(s)
- Kaapjoo Park
- Yuhan Research Institute, 25, Tapsil-ro 35beon-gil, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Byoung Moon Lee
- Yuhan Research Institute, 25, Tapsil-ro 35beon-gil, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Kwan Hoon Hyun
- Yuhan Research Institute, 25, Tapsil-ro 35beon-gil, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Taedong Han
- Yuhan Research Institute, 25, Tapsil-ro 35beon-gil, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Dong Hoon Lee
- Yuhan Research Institute, 25, Tapsil-ro 35beon-gil, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea
| | - Hyun Ho Choi
- Yuhan Research Institute, 25, Tapsil-ro 35beon-gil, Giheung-gu, Yongin-si, Gyeonggi-do, Republic of Korea
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29
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Nakamura A, Terauchi Y. Present status of clinical deployment of glucokinase activators. J Diabetes Investig 2014; 6:124-32. [PMID: 25802718 PMCID: PMC4364845 DOI: 10.1111/jdi.12294] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 12/14/2022] Open
Abstract
Glucokinase is one of four members of the hexokinase family of enzymes. Its expression is limited to the major organs (such as the pancreas, liver, brain and the gastrointestinal tract) that are thought to have an integrated role in glucose sensing. In the liver, phosphorylation of glucose by glucokinase promotes glycogen synthesis, whereas in the β-cells, it results in insulin release. Studies of glucokinase-linked genetically-modified mice and mutations in humans have illustrated the important roles played by glucokinase in whole-body glucose homeostasis, and suggest that the use of pharmacological agents that augment glucokinase activity could represent a viable treatment strategy in patients with type 2 diabetes. Since 2003, many glucokinase activators (GKAs) have been developed, and their ability to lower the blood glucose has been shown in several animal models of type 2 diabetes. Also, we and others have shown in mouse models that GKAs also have the effect of stimulating the proliferation of β-cells. However, the results of recent phase II trials have shown that GKAs lose their efficacy within several months of use, and that their use is associated with a high incidence of hypoglycemia; furthermore, patients treated with GKAs frequently developed dyslipidemia. A better understanding of the role of glucokinase in metabolic effects is required to resolve several issues identified in clinical trials.
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Affiliation(s)
- Akinobu Nakamura
- Division of Immunology and Metabolism, Hokkaido University Graduate School of Medicine Sapporo, Japan
| | - Yasuo Terauchi
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University Yokohama, Japan
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In silico-based combinatorial pharmacophore modelling and docking studies of GSK-3β and GK inhibitors of Hippophae. J Biosci 2014; 38:805-14. [PMID: 24287660 DOI: 10.1007/s12038-013-9367-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Type 2 diabetes is an inevitably progressive disease, with irreversible beta cell failure. Glycogen synthase kinase and Glukokinase, two important enzymes with diverse biological actions in carbohydrate metabolism, are promising targets for developing novel antidiabetic drugs. A combinatorial structure-based molecular docking and pharmacophore modelling study was performed with the compounds of Hippophae salicifolia and H. rhamnoides as inhibitors. Docking with Discovery Studio 3.5 revealed that two compounds from H. salicifolia, viz Lutein D and an analogue of Zeaxanthin, and two compounds from H. rhamnoides, viz Isorhamnetin-3-rhamnoside and Isorhamnetin-7-glucoside, bind significantly to the GSK-3 beta receptor and play a role in its inhibition; whereas in the case of Glucokinase, only one compound from both the plants, i.e. vitamin C, had good binding characteristics capable of activation. The results help to understand the type of interactions that occur between the ligands and the receptors. Toxicity predictions revealed that none of the compounds had hepatotoxic effects and had good absorption as well as solubility characteristics. The compounds did not possess plasma protein-binding, crossing blood-brain barrier ability. Further, in vivo and in vitro studies need to be performed to prove that these compounds can be used effectively as antidiabetic drugs.
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Abstract
Hypoglycemia in the pediatric population is a common finding important to recognize and manage to prevent brain injury. Recent advances in molecular genetics have provided new insight into its biochemical and physiologic basis and have led to more appropriate and specific treatment. Although a major cause of brain injury in pediatrics, the ability to predict the long-term outcome in these patients remains difficult. Identification of these at-risk individuals is important. The physiologic adaptations associated with transition from fetal to neonatal life are now better understood thus allowing for improved surveillance and management. Despite these advances, analytical limitations of point-of-care testing instruments at low glucose concentration continue to persist, This review aims to address these questions and provide an overview of pediatric hypoglycemia and the molecular pathways involved.
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Park K, Lee BM, Hyun KH, Lee DH, Choi HH, Kim H, Chong W, Kim KB, Nam SY. Discovery of 3-(4-methanesulfonylphenoxy)-N-[1-(2-methoxy-ethoxymethyl)-1H-pyrazol-3-yl]-5-(3-methylpyridin-2-yl)-benzamide as a novel glucokinase activator (GKA) for the treatment of type 2 diabetes mellitus. Bioorg Med Chem 2014; 22:2280-93. [DOI: 10.1016/j.bmc.2014.02.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 02/05/2014] [Accepted: 02/09/2014] [Indexed: 02/05/2023]
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Mullooly N, Vernon W, Smith DM, Newsholme P. Elevated levels of branched-chain amino acids have little effect on pancreatic islet cells, but L-arginine impairs function through activation of the endoplasmic reticulum stress response. Exp Physiol 2013; 99:538-51. [PMID: 24334335 DOI: 10.1113/expphysiol.2013.077495] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent metabolic profiling studies have identified a correlation between branched-chain amino acid levels, insulin resistance associated with prediabetes and susceptibility to type 2 diabetes. Glucose and lipids in chronic excess have been reported to induce toxic effects in pancreatic β-cells, but the effect of elevated amino acid concentrations on primary islet cell function has not been investigated to date. The aim of this study was to investigate the effect of chronic exposure to various amino acids on islet cell function in vitro. Isolated rat islets were incubated over periods of 48 h with a range of concentrations of individual amino acids (0.1 μm to 10 mm). After 48 h, islets were assessed for glucose-dependent insulin secretion capacity, proliferation or islet cell apoptosis. We report that elevated levels of branched-chain amino acids have little effect on pancreatic islet cell function or viability; however, increased levels of the amino acid l-arginine were found to be β-cell toxic, causing a dose-dependent decrease in insulin secretion accompanied by a decrease in islet cell proliferation and an increase in islet cell apoptosis. These effects were not due to l-arginine-dependent increases in production of nitric oxide but arose through elicitation of the islet cell endoplasmic reticulum stress response. This novel finding indicates, for the first time, that the l-arginine concentration in vitro may impact negatively on islet cell function, thus indicating further complexity in relationship to in vivo susceptibility of β-cells to nutrient-induced dysfunction.
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Affiliation(s)
- Niamh Mullooly
- * Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
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ER stress in rodent islets of Langerhans is concomitant with obesity and β-cell compensation but not with β-cell dysfunction and diabetes. Nutr Diabetes 2013; 3:e93. [PMID: 24145577 PMCID: PMC3817349 DOI: 10.1038/nutd.2013.35] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 08/15/2013] [Accepted: 09/06/2013] [Indexed: 12/20/2022] Open
Abstract
Objective: The objective of this study was to determine whether ER stress correlates with β-cell dysfunction in obesity-associated diabetes. Methods: Quantitative RT-PCR and western blot analysis were used to investigate changes in the expression of markers of ER stress, the unfolded protein response (UPR) and β-cell function in islets isolated from (1) non-diabetic Zucker obese (ZO) and obese female Zucker diabetic fatty (fZDF) rats compared with their lean littermates and from (2) high-fat-diet-fed fZDF rats (HF-fZDF), to induce diabetes, compared with age-matched non-diabetic obese fZDF rats. Results: Markers of an adaptive ER stress/UPR and β-cell function are elevated in islets isolated from ZO and fZDF rats compared with their lean littermates. In islets isolated from HF-fZDF rats, there was no significant change in the expression of markers of ER stress compared with age matched, obese, non-diabetic fZDF rats. Conclusions: These results provide evidence that obesity-induced activation of the UPR is an adaptive response for increasing the ER folding capacity to meet the increased demand for insulin. As ER stress is not exacerbated in high-fat-diet-induced diabetes, we suggest that failure of the islet to mount an effective adaptive UPR in response to an additional increase in insulin demand, rather than chronic ER stress, may ultimately lead to β-cell failure and hence diabetes.
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Hinklin RJ, Boyd SA, Chicarelli MJ, Condroski KR, DeWolf WE, Lee PA, Lee W, Singh A, Thomas L, Voegtli WC, Williams L, Aicher TD. Identification of a New Class of Glucokinase Activators through Structure-Based Design. J Med Chem 2013; 56:7669-78. [DOI: 10.1021/jm401116k] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Ronald J. Hinklin
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Steven A. Boyd
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Mark J. Chicarelli
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Kevin R. Condroski
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Walter E. DeWolf
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Patrice A. Lee
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Waiman Lee
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Ajay Singh
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Laurie Thomas
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Walter C. Voegtli
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Lance Williams
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
| | - Thomas D. Aicher
- Array BioPharma, 3200 Walnut Street, Boulder, Colorado 80301, United States
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Kim MH, Hong SH, Lee MK. Insulin receptor-overexpressing β-cells ameliorate hyperglycemia in diabetic rats through Wnt signaling activation. PLoS One 2013; 8:e67802. [PMID: 23874448 PMCID: PMC3706479 DOI: 10.1371/journal.pone.0067802] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Accepted: 05/27/2013] [Indexed: 12/31/2022] Open
Abstract
To investigate the therapeutic efficacy and mechanism of β-cells with insulin receptor (IR) overexpression on diabetes mellitus (DM), rat insulinoma (INS-1) cells were engineered to stably express human insulin receptor (INS-IR cells), and subsequently transplanted into streptozotocin- induced diabetic rats. Compared with INS-1 cells, INS-IR cells showed improved β-cell function, including the increase in glucose utilization, calcium mobilization, and insulin secretion, and exhibited a higher rate of cell proliferation, and maintained lower levels of blood glucose in diabetic rats. These results were attributed to the increase of β-catenin/PPARγ complex bindings to peroxisome proliferator response elements in rat glucokinase (GK) promoter and the prolongation of S-phase of cell cycle by cyclin D1. These events resulted from more rapid and higher phosphorylation levels of insulin-signaling intermediates, including insulin receptor substrate (IRS)-1/IRS-2/phosphotylinositol 3 kinase/v-akt murine thymoma viral oncogene homolog (AKT) 1, and the consequent enhancement of β-catenin nuclear translocation and Wnt responsive genes including GK and cyclin D1. Indeed, the higher functionality and proliferation shown in INS-IR cells were offset by β-catenin, cyclin D1, GK, AKT1, and IRS-2 gene depletion. In addition, the promotion of cell proliferation and insulin secretion by Wnt signaling activation was shown by 100 nM insulin treatment, and to a similar degree, was shown in INS-IR cells. In this regard, this study suggests that transferring INS-IR cells into diabetic animals is an effective and feasible DM treatment. Accordingly, the method might be a promising alternative strategy for treatment of DM given the adverse effects of insulin among patients, including the increased risk of modest weight gain and hypoglycemia. Additionally, this study demonstrates that the novel mechanism of cross-talk between insulin and Wnt signaling plays a primary role in the higher therapeutic efficacy of IR-overexpressing β-cells.
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Affiliation(s)
- Mi-Hyun Kim
- Division of Endocrinology and Metabolism, Samsung Biomedical Research Institute, Seoul, Korea
| | - Seung-Hyun Hong
- Bionano Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon, Korea
| | - Moon-Kyu Lee
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
- * E-mail:
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Morrow LA, Leonsson-Zachrisson M, Ericsson H, Wollbratt M, Knutsson M, Hompesch M, Norjavaara E. Safety, pharmacokinetics and pharmacodynamics of multiple-ascending doses of the novel glucokinase activator AZD1656 in patients with type 2 diabetes mellitus. Diabetes Obes Metab 2012; 14:1114-22. [PMID: 22775976 DOI: 10.1111/j.1463-1326.2012.01661.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 05/11/2012] [Accepted: 07/02/2012] [Indexed: 11/27/2022]
Abstract
AIMS To assess the safety, pharmacokinetics and pharmacodynamics of multiple-ascending doses of the novel glucokinase activator AZD1656 in patients with type 2 diabetes mellitus (T2DM). METHODS This randomized, single-blind, placebo-controlled, monotherapy study was carried out in two parts. In part A, 32 patients received AZD1656 (7, 20, 40 or 80 mg) twice daily or placebo for 8 days in hospital. In part B, another 20 patients received, as outpatients, individually titrated AZD1656 15-45 mg twice daily or placebo for 28 days. Safety, pharmacokinetics and pharmacodynamic variables were evaluated. RESULTS AZD1656 was generally well tolerated. Pharmacokinetics of AZD1656 were virtually dose- and time-independent. AZD1656 was rapidly absorbed and eliminated. An active metabolite was formed which had a longer half-life than AZD1656, but showed ∼15% of the area under the plasma concentration versus time curve from 0 to 24 h compared with that of AZD1656. Renal excretion of AZD1656 and the metabolite was low. In part A, fasting plasma glucose (FPG) was reduced by up to 21% and mean 24-h plasma glucose was reduced by up to 24% with AZD1656 versus placebo, depending on dose. No dose-related changes in serum insulin or C-peptide were observed with AZD1656 at the end of treatment. Results in part B confirmed the glucose-lowering effect of AZD1656 versus placebo. CONCLUSIONS AZD1656 was well tolerated with predictable pharmacokinetics in patients with T2DM. Dose-dependent reductions in plasma glucose were observed.
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Affiliation(s)
- L A Morrow
- Profil Institute for Clinical Research, Chula Vista, CA, USA
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Bensellam M, Laybutt DR, Jonas JC. The molecular mechanisms of pancreatic β-cell glucotoxicity: recent findings and future research directions. Mol Cell Endocrinol 2012; 364:1-27. [PMID: 22885162 DOI: 10.1016/j.mce.2012.08.003] [Citation(s) in RCA: 207] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 07/11/2012] [Accepted: 08/01/2012] [Indexed: 02/06/2023]
Abstract
It is well established that regular physiological stimulation by glucose plays a crucial role in the maintenance of the β-cell differentiated phenotype. In contrast, prolonged or repeated exposure to elevated glucose concentrations both in vitro and in vivo exerts deleterious or toxic effects on the β-cell phenotype, a concept termed as glucotoxicity. Evidence indicates that the latter may greatly contribute to the pathogenesis of type 2 diabetes. Through the activation of several mechanisms and signaling pathways, high glucose levels exert deleterious effects on β-cell function and survival and thereby, lead to the worsening of the disease over time. While the role of high glucose-induced β-cell overstimulation, oxidative stress, excessive Unfolded Protein Response (UPR) activation, and loss of differentiation in the alteration of the β-cell phenotype is well ascertained, at least in vitro and in animal models of type 2 diabetes, the role of other mechanisms such as inflammation, O-GlcNacylation, PKC activation, and amyloidogenesis requires further confirmation. On the other hand, protein glycation is an emerging mechanism that may play an important role in the glucotoxic deterioration of the β-cell phenotype. Finally, our recent evidence suggests that hypoxia may also be a new mechanism of β-cell glucotoxicity. Deciphering these molecular mechanisms of β-cell glucotoxicity is a mandatory first step toward the development of therapeutic strategies to protect β-cells and improve the functional β-cell mass in type 2 diabetes.
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Affiliation(s)
- Mohammed Bensellam
- Université catholique de Louvain, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Brussels, Belgium
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Aicher TD, Boyd SA, McVean M, Celeste A. Novel therapeutics and targets for the treatment of diabetes. Expert Rev Clin Pharmacol 2012; 3:209-29. [PMID: 22111568 DOI: 10.1586/ecp.10.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The microvascular complications of insufficiently controlled diabetes (neuropathy, retinopathy and nephropathy) and the marked increased risk of macrovascular events (e.g., stroke and myocardial infarction) have a dire impact on society in both human and economic terms. In Type 1 diabetes total β-cell loss occurs. In Type 2 diabetes, partial β-cell loss occurs before diagnosis, and the progressive β-cell loss during the life of the patient increases the severity of the disease. In patients with diabetes, increased insulin resistance in the muscle and liver are key pathophysiologic defects. In addition, defects in metabolic processes in the fat, GI tract, brain, pancreatic α-cells and kidney are detrimental to the overall health of the patient. This review addresses novel therapies for these deficiencies in clinical and preclinical evaluation, emphasizing their potential to address glucose homeostasis, β-cell mass and function, and the comorbidities of cardiovascular disease and obesity.
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Affiliation(s)
- Thomas D Aicher
- Principal Research Investigator, Array BioPharma Inc., 3200 Walnut Street, Boulder, CO 80301, USA.
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Beall C, Hamilton DL, Gallagher J, Logie L, Wright K, Soutar MP, Dadak S, Ashford FB, Haythorne E, Du Q, Jovanović A, McCrimmon RJ, Ashford MLJ. Mouse hypothalamic GT1-7 cells demonstrate AMPK-dependent intrinsic glucose-sensing behaviour. Diabetologia 2012; 55:2432-44. [PMID: 22760787 PMCID: PMC3411292 DOI: 10.1007/s00125-012-2617-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Accepted: 05/21/2012] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Hypothalamic glucose-excited (GE) neurons contribute to whole-body glucose homeostasis and participate in the detection of hypoglycaemia. This system appears defective in type 1 diabetes, in which hypoglycaemia commonly occurs. Unfortunately, it is at present unclear which molecular components required for glucose sensing are produced in individual neurons and how these are functionally linked. We used the GT1-7 mouse hypothalamic cell line to address these issues. METHODS Electrophysiological recordings, coupled with measurements of gene expression and protein levels and activity, were made from unmodified GT1-7 cells and cells in which AMP-activated protein kinase (AMPK) catalytic subunit gene expression and activity were reduced. RESULTS Hypothalamic GT1-7 neurons express the genes encoding glucokinase and ATP-sensitive K(+) channel (K(ATP)) subunits K ( ir ) 6.2 and Sur1 and exhibit GE-type glucose-sensing behaviour. Lowered extracellular glucose concentration hyperpolarised the cells in a concentration-dependent manner, an outcome that was reversed by tolbutamide. Inhibition of glucose uptake or metabolism hyperpolarised cells, showing that energy metabolism is required to maintain their resting membrane potential. Short hairpin (sh)RNA directed to Ampkα2 (also known as Prkaa2) reduced GT1-7 cell AMPKα2, but not AMPKα1, activity and lowered the threshold for hypoglycaemia-induced hyperpolarisation. shAmpkα1 (also known as Prkaa1) had no effect on glucose-sensing or AMPKα2 activity. Decreased uncoupling protein 2 (Ucp2) mRNA was detected in AMPKα2-reduced cells, suggesting that AMPKα2 regulates UCP2 levels. CONCLUSIONS/INTERPRETATION We have demonstrated that GT1-7 cells closely mimic GE neuron glucose-sensing behaviour, and reducing AMPKα2 blunts their responsiveness to hypoglycaemic challenge, possibly by altering UCP2 activity. These results show that suppression of AMPKα2 activity inhibits normal glucose-sensing behaviour and may contribute to defective detection of hypoglycaemia.
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Affiliation(s)
- C. Beall
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - D. L. Hamilton
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - J. Gallagher
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - L. Logie
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - K. Wright
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - M. P. Soutar
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - S. Dadak
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - F. B. Ashford
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - E. Haythorne
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - Q. Du
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - A. Jovanović
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - R. J. McCrimmon
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
| | - M. L. J. Ashford
- Medical Research Institute, Division of Cardiovascular & Diabetes Medicine, Ninewells Hospital & Medical School, University of Dundee, Dundee, DD1 9SY UK
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Nakamura A, Togashi Y, Orime K, Sato K, Shirakawa J, Ohsugi M, Kubota N, Kadowaki T, Terauchi Y. Control of beta cell function and proliferation in mice stimulated by small-molecule glucokinase activator under various conditions. Diabetologia 2012; 55:1745-54. [PMID: 22456697 DOI: 10.1007/s00125-012-2521-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 02/20/2012] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS We investigated changes in the expression of genes involved in beta cell function and proliferation in mouse islets stimulated with glucokinase activator (GKA) in order to elucidate the mechanisms by which GKA stimulates beta cell function and proliferation. METHODS Islets isolated from mice were used to investigate changes in the expression of genes related to beta cell function and proliferation stimulated by GKA. In addition, Irs2 knockout (Irs2 (-/-)) mice on a high-fat diet or a high-fat diet containing GKA were used to investigate the effects of GKA on beta cell proliferation in vivo. RESULTS In wild-type mice, Irs2 and Pdx1 expression was increased by GKA. In Irs2 (-/-) mice, GKA administration increased the glucose-stimulated secretion of insulin and Pdx1 expression, but not beta cell proliferation. It was particularly noteworthy that oxidative stress inhibited the upregulation of the Irs2 and Pdx1 genes induced by GKA. Moreover, whereas neither GKA alone nor exendin-4 alone upregulated the expression of Irs2 and Pdx1 in the islets of db/db mice, prior administration of exendin-4 to the mice caused GKA to increase the expression of these genes. CONCLUSIONS/INTERPRETATION GKA-stimulated IRS2 production affected beta cell proliferation but not beta cell function. Oxidative stress diminished the effects of GKA on the changes in expression of genes involved in beta cell function and proliferation. A combination of GKA and an incretin-related agent might therefore be effective in therapy.
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Affiliation(s)
- A Nakamura
- Department of Endocrinology and Metabolism, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
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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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Verspohl EJ. Novel Pharmacological Approaches to the Treatment of Type 2 Diabetes. Pharmacol Rev 2012; 64:188-237. [DOI: 10.1124/pr.110.003319] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Mao W, Ning M, Liu Z, Zhu Q, Leng Y, Zhang A. Design, synthesis, and pharmacological evaluation of benzamide derivatives as glucokinase activators. Bioorg Med Chem 2012; 20:2982-91. [PMID: 22459213 DOI: 10.1016/j.bmc.2012.03.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/01/2012] [Accepted: 03/01/2012] [Indexed: 01/28/2023]
Abstract
A series of benzamide derivatives were assembled by using the privileged-fragment-merging (PFM) strategy and their SAR studies as glucokinase activators were described. Compounds 5 and 16b were identified having a suitable balance of potency and activation profile. They showed EC(50) values of 28.3 and 44.8 nM, and activation folds of 2.4 and 2.2, respectively. However, both compounds displayed a minor reduction in plasma glucose levels on imprinting control region (ICR) mice. Unfavorable pharmacokinetic profiles (PK) were also observed on these two compounds.
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Affiliation(s)
- Weiwei Mao
- Synthetic Organic and Medicinal Chemistry Laboratory, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China
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Guertin KR. Allosteric Activators of Glucokinase (GK) for the Treatment of Type 2 Diabetes. KINASE DRUG DISCOVERY 2011. [DOI: 10.1039/9781849733557-00244] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Seino S, Tanaka Y, Honma T, Yanaka M, Sato K, Shinohara N, Ito J, Tsuduki T, Nakagawa K, Miyazawa T, Ikeda I. Atopic dermatitis causes lipid accumulation in the liver of NC/Nga mouse. J Clin Biochem Nutr 2011; 50:152-7. [PMID: 22448097 PMCID: PMC3303478 DOI: 10.3164/jcbn.11-29] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 05/27/2011] [Indexed: 11/22/2022] Open
Abstract
Various factors have been reported to influence lipid metabolism and cause metabolic syndrome. However, the influence of allergy on the liver that plays important role of lipid metabolism has not been clarified. The aim of this study was to examine the influence of allergy on lipid metabolism of liver. A model of atopic dermatitis was developed in the NC/Nga mouse using picryl chloride to induce allergy. Lipid metabolism parameters were measured and the mechanism of changes in these parameters was examined using DNA microarray analysis and quantitative reverse transcriptase PCR. Triacylglycerol accumulation was promoted in the liver in the mouse atopic dermatitis model despite reductions in food intake, body weight gain, and serum glucose. As this mechanism, it was thought that atopic dermatitis caused the suppression of fatty acid β-oxidation. These results suggest that atopic dermatitis causes lipid accumulation in the liver.
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Affiliation(s)
- Satoshi Seino
- Laboratory of Food and Biomolecular Science, Graduate School of Agriculture, Tohoku University, Sendai 981-8555, Japan
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Jung H, Joo J, Jeon Y, Lee J, In J, Kim D, Kang E, Kim Y, Lim Y, Kang J, Choi J. Advanced glycation end products downregulate glucokinase in mice. Diabetes Metab Res Rev 2011; 27:557-63. [PMID: 21538775 DOI: 10.1002/dmrr.1208] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Glucokinase, the enzyme that catalyses the conversion of glucose to G-6-P, plays a key role in glucose metabolism. AGEs are implicated in diabetic complications. A previous study reported that AGEs decreased β-cell function through inhibition of cytochrome c oxidase and adenosine triphosphate synthesis. This study investigated the effects of AGEs on glucokinase and islet function. METHODS Six-month-old male C57BL6 mice were divided into bovine serum albumin (BSA) and AGE-BSA groups. BSA (200 µg/g) and AGE-BSA (60 U/g) were administered intraperitoneally twice daily. After 2 weeks, serum AGE levels were measured, oral glucose tolerance test was performed, and insulin levels during the oral glucose tolerance test were determined. Glucokinase protein expression level and activity were measured in pancreatic islets. RESULTS We observed that the normal mice (C57/BL6) treated for 2 weeks with AGE-BSA showed impaired glucose tolerance and decrease in acute insulin release. Glucokinase activity in islets from the AGE-BSA-treated mice was significantly inhibited and accompanied by blunted response of islets to high glucose stimulation. Moreover, in vitro experiments showed that glucokinase protein expression was decreased, its activity was inhibited, and islet function was decreased. GKA partially restored glucokinase activity and islet function caused by AGEs. CONCLUSIONS We concluded that AGEs inhibited glucokinase activity, leading to islet dysfunction in mouse pancreatic islets.
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Affiliation(s)
- Hongsoo Jung
- Department of Anesthesiolgy and Pain Medicine, Catholic Unversity of Saint Vincent Hospital, Suwon, Republic of Korea
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McGlasson L, Best L, Brown PD. The glucokinase activator GKA50 causes an increase in cell volume and activation of volume-regulated anion channels in rat pancreatic β-cells. Mol Cell Endocrinol 2011; 342:48-53. [PMID: 21664426 DOI: 10.1016/j.mce.2011.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 05/06/2011] [Accepted: 05/22/2011] [Indexed: 10/18/2022]
Abstract
Glucokinase plays a key role in the metabolism of glucose by pancreatic β-cells. In this study the effects of the glucokinase activator GKA50 on cell volume and electrical activity in rat β-cells were examined. One micro molar GKA50 caused an increase in β-cell volume in the presence of 4mM glucose. GKA50 also caused a depolarisation of β-cell membrane potential and increased electrical activity. These changes were associated with the activation of inward whole-cell currents, and were attenuated by the anion channel inhibitor 5-nitro-2-(3-phenylpropylamino) benzoic acid. In single channel experiments, the open probability of volume-regulated anion channels (VRAC) was increased from 0.03±0.01 to 0.19±0.04 (n=3) by the GKA50. The data suggest that a GKA50-evoked increase in glucose metabolism causes an increase in β-cell volume. This in turn activates VRAC leading to a depolarisation of the cell membrane potential.
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Affiliation(s)
- Lisa McGlasson
- Faculty of Life Sciences and Medicine, University of Manchester, Manchester M13 9NT, UK
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50
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Gill D, Brocklehurst KJ, Brown HWG, Smith DM. Upregulation of β-cell genes and improved function in rodent islets following chronic glucokinase activation. J Mol Endocrinol 2011; 47:59-67. [PMID: 21571864 DOI: 10.1530/jme-10-0157] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Glucokinase (GK) plays a critical role in controlling blood glucose; GK activators have been shown to stimulate insulin secretion acutely both in vitro and in vivo. Sustained stimulation of insulin secretion could potentially lead to β-cell exhaustion; this study examines the effect of chronic GK activation on β-cells. Gene expression and insulin secretion were measured in rodent islets treated in vitro with GKA71 for 72 h. Key β-cell gene expression was measured in rat, mouse and global GK heterozygous knockout mouse islets (gk(del/wt)). Insulin secretion, after chronic exposure to GKA71, was measured in perifused rat islets. GKA71 acutely increased insulin secretion in rat islets in a glucose-dependent manner. Chronic culture of mouse islets with GKA71 in 5 mmol/l glucose significantly increased the expression of insulin, IAPP, GLUT2, PDX1 and PC1 and decreased the expression of C/EBPβ compared with 5 mmol/l glucose alone. Similar increases were shown for insulin, GLUT2, IAPP and PC1 in chronically treated rat islets. Insulin mRNA was also increased in GKA71-treated gk(del/wt) islets. No changes in GK mRNA were observed. Glucose-stimulated insulin secretion was improved in perifused rat islets following chronic treatment with GKA71. This was associated with a greater insulin content and GK protein level. Chronic treatment of rodent islets with GKA71 showed an upregulation of key β-cell genes including insulin and an increase in insulin content and GK protein compared with glucose alone.
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Affiliation(s)
- D Gill
- AstraZeneca Diabetes and Obesity Drug Discovery, CVGI iMED, 3S42C Mereside, Alderley Park, Macclesfield, Cheshire SK10 4TG, UK
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