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Goode RA, Hum JM, Kalwat MA. Therapeutic Strategies Targeting Pancreatic Islet β-Cell Proliferation, Regeneration, and Replacement. Endocrinology 2022; 164:6836713. [PMID: 36412119 PMCID: PMC9923807 DOI: 10.1210/endocr/bqac193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/16/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022]
Abstract
Diabetes results from insufficient insulin production by pancreatic islet β-cells or a loss of β-cells themselves. Restoration of regulated insulin production is a predominant goal of translational diabetes research. Here, we provide a brief overview of recent advances in the fields of β-cell proliferation, regeneration, and replacement. The discovery of therapeutic targets and associated small molecules has been enabled by improved understanding of β-cell development and cell cycle regulation, as well as advanced high-throughput screening methodologies. Important findings in β-cell transdifferentiation, neogenesis, and stem cell differentiation have nucleated multiple promising therapeutic strategies. In particular, clinical trials are underway using in vitro-generated β-like cells from human pluripotent stem cells. Significant challenges remain for each of these strategies, but continued support for efforts in these research areas will be critical for the generation of distinct diabetes therapies.
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Affiliation(s)
- Roy A Goode
- Division of Biomedical Sciences, College of Osteopathic Medicine, Marian University, Indianapolis, IN, USA
| | - Julia M Hum
- Division of Biomedical Sciences, College of Osteopathic Medicine, Marian University, Indianapolis, IN, USA
| | - Michael A Kalwat
- Correspondence: Michael A. Kalwat, PhD, Lilly Diabetes Center of Excellence, Indiana Biosciences Research Institute, 1210 Waterway Blvd, Suite 2000, Indianapolis, IN 46202, USA. or
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2
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Casas B, Vilén L, Bauer S, Kanebratt KP, Wennberg Huldt C, Magnusson L, Marx U, Andersson TB, Gennemark P, Cedersund G. Integrated experimental-computational analysis of a HepaRG liver-islet microphysiological system for human-centric diabetes research. PLoS Comput Biol 2022; 18:e1010587. [PMID: 36260620 PMCID: PMC9621595 DOI: 10.1371/journal.pcbi.1010587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 10/31/2022] [Accepted: 09/19/2022] [Indexed: 11/05/2022] Open
Abstract
Microphysiological systems (MPS) are powerful tools for emulating human physiology and replicating disease progression in vitro. MPS could be better predictors of human outcome than current animal models, but mechanistic interpretation and in vivo extrapolation of the experimental results remain significant challenges. Here, we address these challenges using an integrated experimental-computational approach. This approach allows for in silico representation and predictions of glucose metabolism in a previously reported MPS with two organ compartments (liver and pancreas) connected in a closed loop with circulating medium. We developed a computational model describing glucose metabolism over 15 days of culture in the MPS. The model was calibrated on an experiment-specific basis using data from seven experiments, where HepaRG single-liver or liver-islet cultures were exposed to both normal and hyperglycemic conditions resembling high blood glucose levels in diabetes. The calibrated models reproduced the fast (i.e. hourly) variations in glucose and insulin observed in the MPS experiments, as well as the long-term (i.e. over weeks) decline in both glucose tolerance and insulin secretion. We also investigated the behaviour of the system under hypoglycemia by simulating this condition in silico, and the model could correctly predict the glucose and insulin responses measured in new MPS experiments. Last, we used the computational model to translate the experimental results to humans, showing good agreement with published data of the glucose response to a meal in healthy subjects. The integrated experimental-computational framework opens new avenues for future investigations toward disease mechanisms and the development of new therapies for metabolic disorders. Microphysiological systems (MPS) are powerful tools to unravel biological knowledge underlying disease. MPS provide a physiologically relevant, human-based in vitro setting, which can potentially yield better translatability to humans than current animal models and traditional cell cultures. However, mechanistic interpretation and extrapolation of the experimental results to human outcome remain significant challenges. In this study, we confront these challenges using an integrated experimental-computational approach. We present a computational model describing glucose metabolism in a previously reported MPS integrating liver and pancreas. This MPS supports a homeostatic feedback loop between HepaRG/HHSteC spheroids and pancreatic islets, and allows for detailed investigations of mechanisms underlying type 2 diabetes in humans. We show that the computational model captures the complex dynamics of glucose-insulin regulation observed in the system, and can provide mechanistic insight into disease progression features, such as insulin resistance and β-cell dynamics. Furthermore, the computational model can explain key differences in temporal dynamics between MPS and human responses, and thus provides a tool for translating experimental insights into human outcome. The integrated experimental-computational framework opens new avenues for future investigations toward disease mechanisms and the development of new therapies for metabolic disorders.
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Affiliation(s)
- Belén Casas
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Liisa Vilén
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | | | - Kajsa P. Kanebratt
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Charlotte Wennberg Huldt
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Lisa Magnusson
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | | | - Tommy B. Andersson
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Peter Gennemark
- Drug Metabolism and Pharmacokinetics, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
| | - Gunnar Cedersund
- Department of Biomedical Engineering, Linköping University, Linköping, Sweden
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
- * E-mail:
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3
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Prolonged insulin-induced hypoglycaemia reduces ß-cell activity rather than number in pancreatic islets in non-diabetic rats. Sci Rep 2022; 12:14113. [PMID: 35982111 PMCID: PMC9388517 DOI: 10.1038/s41598-022-18398-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/10/2022] [Indexed: 12/05/2022] Open
Abstract
Pancreatic β-cells have an extraordinary ability to adapt to acute fluctuations in glucose levels by rapid changing insulin production to meet metabolic needs. Although acute changes have been characterised, effects of prolonged metabolic stress on β-cell dynamics are still unclear. Here, the aim was to investigate pancreatic β-cell dynamics and function during and after prolonged hypoglycaemia. Hypoglycaemia was induced in male and female rats by infusion of human insulin for 8 weeks, followed by a 4-week infusion-free recovery period. Animals were euthanized after 4 or 8 weeks of infusion, and either 2 days and 4 weeks after infusion-stop. Total volumes of pancreatic islets and β-cell nuclei, islet insulin and glucagon content, and plasma c-peptide levels were quantified. Prolonged hypoglycaemia reduced c-peptide levels, islet volume and almost depleted islet insulin. Relative β-cell nuclei: total pancreas volume decreased, while being unchanged relative to islet volume. Glucagon: total pancreas volume decreased during hypoglycaemia, whereas glucagon: islet volume increased. Within two days after infusion-stop, plasma glucose and c-peptide levels normalised and all remaining parameters were fully reversed after 4 weeks. In conclusion, our findings indicate that prolonged hypoglycaemia inactivates β-cells, which can rapidly be reactivated when needed, demonstrating the high plasticity of β-cells even following prolonged suppression.
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4
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Lv C, Sun Y, Zhang ZY, Aboelela Z, Qiu X, Meng ZX. β-cell dynamics in type 2 diabetes and in dietary and exercise interventions. J Mol Cell Biol 2022; 14:6656373. [PMID: 35929791 PMCID: PMC9710517 DOI: 10.1093/jmcb/mjac046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 05/07/2022] [Accepted: 08/03/2022] [Indexed: 01/14/2023] Open
Abstract
Pancreatic β-cell dysfunction and insulin resistance are two of the major causes of type 2 diabetes (T2D). Recent clinical and experimental studies have suggested that the functional capacity of β-cells, particularly in the first phase of insulin secretion, is a primary contributor to the progression of T2D and its associated complications. Pancreatic β-cells undergo dynamic compensation and decompensation processes during the development of T2D, in which metabolic stresses such as endoplasmic reticulum stress, oxidative stress, and inflammatory signals are key regulators of β-cell dynamics. Dietary and exercise interventions have been shown to be effective approaches for the treatment of obesity and T2D, especially in the early stages. Whilst the targeted tissues and underlying mechanisms of dietary and exercise interventions remain somewhat vague, accumulating evidence has implicated the improvement of β-cell functional capacity. In this review, we summarize recent advances in the understanding of the dynamic adaptations of β-cell function in T2D progression and clarify the effects and mechanisms of dietary and exercise interventions on β-cell dysfunction in T2D. This review provides molecular insights into the therapeutic effects of dietary and exercise interventions on T2D, and more importantly, it paves the way for future research on the related underlying mechanisms for developing precision prevention and treatment of T2D.
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Affiliation(s)
- Chengan Lv
- Department of Pathology and Pathophysiology and Metabolic Research Center of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China,Key Laboratory of Disease Proteomics of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Yuchen Sun
- Department of Pathology and Pathophysiology and Metabolic Research Center of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China,Key Laboratory of Disease Proteomics of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou 310058, China,Zhejiang University–University of Edinburgh Institute (ZJE), Zhejiang University, Haining 314400, China
| | - Zhe Yu Zhang
- Department of Pathology and Pathophysiology and Metabolic Research Center of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China,Key Laboratory of Disease Proteomics of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Zeyad Aboelela
- Department of Pathology and Pathophysiology and Metabolic Research Center of the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China,Key Laboratory of Disease Proteomics of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou 310058, China,Bachelors of Surgery, Bachelors of Medicine (MBBS), Zhejiang University School of Medicine, Hangzhou 310003, China
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5
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Martyushev-Poklad AV, Yankevich DS, Petrova MV, Savitskaya NG. [Two models of insulin resistance development and the strategy to combat age-related diseases: literature review]. PROBLEMY ENDOKRINOLOGII 2022; 68:59-68. [PMID: 36104967 DOI: 10.14341/probl13090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/11/2022] [Accepted: 05/30/2022] [Indexed: 01/01/2023]
Abstract
BACKGROUND Insulin resistance (IR) is the root cause of most age-related diseases (ARD), the major challenge for today's health systems. Therefore, adequate understanding of the mechanisms underlying IR is essential to build effective ARD prevention. OBJECTIVE Analyze the existing models of IR causation and progression in order to justify the most effective ARD prevention strategy. METHODS Search and analysis of publications on IR and hyperinsulinemia (HI) from databases elibrary.ru, PubMed, and Google Scholar. RESULTS Two models of IR development are analyzed along with the relationship between IR, HI, and obesity. The prevailing model considers obesity (imbalance of caloric intake and energy expenditure) as the main factor in the development of IR; HI is seen as a consequence of IR, mostly insignificant for the outcomes of IR. The model contradicts many experimental and clinical findings. The strategy to combat ARDs that follows from the model (hypocaloric diet and pharmacotherapy of IR) has proven mostly ineffective.The alternative model (IR as a consequence of HI, and obesity as one of IR manifestations) is more consistent with the pool of experimental and clinical data. It more precisely predicts ARD development and allows more adequate correction of adverse lifestyle factors. It corresponds to a different strategy for combating ARD: emphasis on low-carb diet and longer fasting window combined with consideration of other factors of IR. CONCLUSION If the prevailing model of IR development is revised, this should open up opportunities for more effective early prevention of a wide range of chronic diseases in which the role of IR is significant.
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Affiliation(s)
| | - D S Yankevich
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology
| | - M V Petrova
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology
| | - N G Savitskaya
- Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology
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6
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Pereira de Arruda EH, Vieira da Silva GL, da Rosa-Santos CA, Arantes VC, de Barros Reis MA, Colodel EM, Gaspar de Moura E, Lisboa PC, Carneiro EM, Damazo AS, Latorraca MQ. Protein restriction during pregnancy impairs intra-islet GLP-1 and the expansion of β-cell mass. Mol Cell Endocrinol 2020; 518:110977. [PMID: 32791189 DOI: 10.1016/j.mce.2020.110977] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 07/14/2020] [Accepted: 08/03/2020] [Indexed: 12/26/2022]
Abstract
We evaluated whether protein restriction during pregnancy alters the morphometry of pancreatic islets, the intra-islet glucagon-like peptide-1 (GLP-1) production, and the anti-apoptotic signalling pathway modulated by GLP-1. Control non-pregnant (CNP) and control pregnant (CP) rats were fed a 17% protein diet, and low-protein non-pregnant (LPNP) and low-protein pregnant (LPP) groups were fed a 6% protein diet. The masses of islets and β-cells were similar in the LPNP group and the CNP group but were higher in the CP group than in the CNP group and were equal in the LPP group and the LPNP group. Both variables were lower in the LPP group than in the CP group. Prohormone convertase 2 and GLP-1 fluorescence in α-cells was lower in the low-protein groups than in the control groups. The least PC2/glucagon colocalization was observed in the LPP group, and the most was observed in the CP group. There was less prohormone convertase 1/3/glucagon colocalization in the LPP group than in the CP group. GLP-1/glucagon colocalization was similar in the LPP, CP and CNP groups, which showed less GLP-1/glucagon colocalization than the LPNP group. The mRNA Pka, Creb and Pdx-1 contents were higher in islets from pregnant rats than in islets from non-pregnant rats. Protein restriction during pregnancy impaired the mass of β-cells and the intra-islet GLP-1 production but did not interfere with the transcription of genes of the anti-apoptotic signalling pathway modulated by GLP-1.
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Affiliation(s)
| | | | - Chaiane Aline da Rosa-Santos
- Mestrado em Nutrição, Alimentos e Metabolismo, Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Vanessa Cristina Arantes
- Departamento de Alimentos e Nutrição, Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | | | - Edson Moleta Colodel
- Departamento de Clínica Médica Veterinária, Faculdade de Agronomia e Medicina Veterinária, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Egberto Gaspar de Moura
- Laboratório de Fisiologia Endócrina, Departamento de Ciências Fisiológicas, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Patrícia Cristina Lisboa
- Laboratório de Fisiologia Endócrina, Departamento de Ciências Fisiológicas, Instituto de Biologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Everardo Magalhães Carneiro
- Departamento de Anatomia, Biologia Cellular, Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brazil
| | - Amílcar Sabino Damazo
- Departamento de Ciências Básicas da Saúde, Faculdade de Medicina, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil
| | - Márcia Queiroz Latorraca
- Departamento de Alimentos e Nutrição, Faculdade de Nutrição, Universidade Federal de Mato Grosso, Cuiabá, MT, Brazil.
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7
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Modulation of Rab7a-mediated growth factor receptor trafficking inhibits islet beta cell apoptosis and autophagy under conditions of metabolic stress. Sci Rep 2020; 10:15741. [PMID: 32978479 PMCID: PMC7519639 DOI: 10.1038/s41598-020-72939-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 09/09/2020] [Indexed: 01/01/2023] Open
Abstract
Regenerative medicine approaches to enhancing beta cell growth and survival represent potential treatments for diabetes. It is known that growth factors such as insulin, IGF-1 and HGF support beta cell growth and survival, but in people with type 2 diabetes the destructive effects of metabolic stress predominate and beta cell death or dysfunction occurs. In this study we explore the novel hypothesis that regulation of growth factor receptor trafficking can be used to promote islet beta cell survival. Growth factor signalling is dependent on the presence of cell surface receptors. Endosomal trafficking and subsequent recycling or degradation of these receptors is controlled by the Rab GTPase family of proteins. We show that Rab7a siRNA inhibition enhances IGF-1 and HGF signalling in beta cells and increases expression of the growth factor receptors IGF-1R and c-Met. Furthermore, Rab7a inhibition promotes beta cell growth and islet survival, and protects against activation of apoptosis and autophagy pathways under conditions of metabolic stress. This study therefore demonstrates that Rab7a-mediated trafficking of growth factor receptors controls beta cell survival. Pharmaceutical Rab7a inhibition may provide a means to promote beta cell survival in the context of metabolic stress and prevent the onset of type 2 diabetes.
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8
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Lin YCD, Huang HY, Shrestha S, Chou CH, Chen YH, Chen CR, Hong HC, Li J, Chang YA, Chiew MY, Huang YR, Tu SJ, Sun TH, Weng SL, Tseng CP, Huang HD. Multi-omics profiling reveals microRNA-mediated insulin signaling networks. BMC Bioinformatics 2020; 21:389. [PMID: 32938376 PMCID: PMC7496206 DOI: 10.1186/s12859-020-03678-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Background MicroRNAs (miRNAs) play a key role in mediating the action of insulin on cell growth and the development of diabetes. However, few studies have been conducted to provide a comprehensive overview of the miRNA-mediated signaling network in response to glucose in pancreatic beta cells. In our study, we established a computational framework integrating multi-omics profiles analyses, including RNA sequencing (RNA-seq) and small RNA sequencing (sRNA-seq) data analysis, inverse expression pattern analysis, public data integration, and miRNA targets prediction to illustrate the miRNA-mediated regulatory network at different glucose concentrations in INS-1 pancreatic beta cells (INS-1), which display important characteristics of the pancreatic beta cells. Results We applied our computational framework to the expression profiles of miRNA/mRNA of INS-1, at different glucose concentrations. A total of 1437 differentially expressed genes (DEGs) and 153 differentially expressed miRNAs (DEmiRs) were identified from multi-omics profiles. In particular, 121 DEmiRs putatively regulated a total of 237 DEGs involved in glucose metabolism, fatty acid oxidation, ion channels, exocytosis, homeostasis, and insulin gene regulation. Moreover, Argonaute 2 immunoprecipitation sequencing, qRT-PCR, and luciferase assay identified Crem, Fn1, and Stc1 are direct targets of miR-146b and elucidated that miR-146b acted as a potential regulator and promising target to understand the insulin signaling network. Conclusions In this study, the integration of experimentally verified data with system biology framework extracts the miRNA network for exploring potential insulin-associated miRNA and their target genes. The findings offer a potentially significant effect on the understanding of miRNA-mediated insulin signaling network in the development and progression of pancreatic diabetes.
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Affiliation(s)
- Yang-Chi-Dung Lin
- School of Life and Health Sciences, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China
| | - Hsi-Yuan Huang
- School of Life and Health Sciences, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China
| | - Sirjana Shrestha
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 300, Taiwan.,Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Chih-Hung Chou
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 300, Taiwan.,Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Yen-Hua Chen
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, NY, 10021, USA
| | - Chi-Ru Chen
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Hsiao-Chin Hong
- School of Life and Health Sciences, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China
| | - Jing Li
- School of Life and Health Sciences, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China.,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China
| | - Yi-An Chang
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Men-Yee Chiew
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Ya-Rong Huang
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Siang-Jyun Tu
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Ting-Hsuan Sun
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Shun-Long Weng
- Department of Obstetrics and Gynecology, Hsinchu Mackay Memorial Hospital, Hsinchu, 300, Taiwan
| | - Ching-Ping Tseng
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 300, Taiwan.
| | - Hsien-Da Huang
- School of Life and Health Sciences, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China. .,Warshel Institute for Computational Biology, The Chinese University of Hong Kong, Longgang District, Shenzhen, 518172, Guangdong Province, China. .,Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, 300, Taiwan.
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9
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Kopp W. Development of Obesity: The Driver and the Passenger. Diabetes Metab Syndr Obes 2020; 13:4631-4642. [PMID: 33281458 PMCID: PMC7709141 DOI: 10.2147/dmso.s280146] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/03/2020] [Indexed: 12/16/2022] Open
Abstract
Obesity has reached epidemic proportions and is one of the greatest challenges for public health in the twenty-first century. The macronutrient composition of diets, in particular the amount and ratio of carbohydrates, fat and protein, have received considerable attention in recent decades due to its potential relevance to the development of obesity and weight loss. The effects of various macronutrients on body weight regulation are still under debate. High-carbohydrate diets, and particularly high-fat diets, have been blamed for the increase in the prevalence of obesity. This paper shows that neither fat nor carbohydrates are fattening per se. Mixed diets with substantial amounts of fat and high-glycemic carbohydrates, like current WDs, are required to promote weight gain and obesity. High-glycemic carbohydrates are the active partner (the "driver"), which promotes fat storage through its insulinogenic effect, while fat is the passive partner (the "passenger") on the way to obesity. Elevated insulin levels (postprandial, but more importantly due to hypersecretion and hyperinsulinemia) promote fat storage and play a key role in obesogenesis and the obesity epidemic. Furthermore, mixed diets high in high-glycemic carbohydrates and fat promote fetal programming, with long-term adverse impacts on the offspring, including insulin hypersecretion, (childhood) obesity and metabolic diseases. Maternal obesity and high weight gain during pregnancy have also been linked to deleterious effects on fetal programming. As the global obesity epidemic increasingly affects women of reproductive age, a significant percentage of fetuses will experience fetal programming with a tendency towards obesity - a self-reinforcing process that further fuels the epidemic. A change in lifestyle and diet composition is needed to prevent or limit the development of obesity and related diseases.
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Affiliation(s)
- Wolfgang Kopp
- Diagnostikzentrum Graz, Graz, 8043, Austria
- Correspondence: Wolfgang Kopp Former Head of Diagnostikzentrum (retired), Mariatrosterstraße 41, Graz8043, Austria Email
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10
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Increased proliferation and altered cell cycle regulation in pancreatic stem cells derived from patients with congenital hyperinsulinism. PLoS One 2019; 14:e0222350. [PMID: 31525223 PMCID: PMC6746350 DOI: 10.1371/journal.pone.0222350] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 08/27/2019] [Indexed: 12/14/2022] Open
Abstract
Congenital hyperinsulinism (CHI) is characterised by inappropriate insulin secretion causing profound hypoglycaemia and brain damage if inadequately controlled. Pancreatic tissue isolated from patients with diffuse CHI shows abnormal proliferation rates, the mechanisms of which are not fully resolved. Understanding cell proliferation in CHI may lead to new therapeutic options, alongside opportunities to manipulate β-cell mass in patients with diabetes. We aimed to generate cell-lines from CHI pancreatic tissue to provide in vitro model systems for research. Three pancreatic mesenchymal stem cell-lines (CHIpMSC1-3) were derived from patients with CHI disease variants: focal, atypical and diffuse. All CHIpMSC lines demonstrated increased proliferation compared with control adult-derived pMSCs. Cell cycle alterations including increased CDK1 levels and decreased p27Kip1 nuclear localisation were observed in CHIpMSCs when compared to control pMSCs. In conclusion, CHIpMSCs are a useful in vitro model to further understand the cell cycle alterations leading to increased islet cell proliferation in CHI.
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11
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Ozisik H, Suner A, Cetinkalp S. Prolactin effect on blood glucose and insülin in breastfeeding women. Diabetes Metab Syndr 2019; 13:1765-1767. [PMID: 31235091 DOI: 10.1016/j.dsx.2019.03.045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 03/29/2019] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Prolactin plays a significant role in lactation and prolactin levels are increasing physiologically in pregnancy and breastfeeding period. There might be different mechanisms during breastfeeding between prolactin and insülin levels. In order to highlighten this mechanisms we compared the plasma levels of glucose, insülin, prolactin, C-peptid in basal situations and after taking 75 gr carbonhydrate, 20 gr protein, 23 gr fat in breastfeeding and in non lactating women. MATERIAL AND METHODS Participiants and measurements: The study population included 12 breastfeeding women and 11 healthy non lactating women as a control group. We collected information on age, history of gestational diabetes mellitus, family history of diabetes mellitus, natality, the symptoms of hypoglycemia. Weight, height and waist circumference were measured and body mass index (BMI) was calculated as weight (kg)/height (m2). RESULTS Prolactin was inversely correlated with HbA1c and 2. hour C peptide (p=0.005, r=-0.564; p=0.008, r=-0.539). Prolactin was not significantly correlated with HOMA-IR, HOMA-IS, AUC-I or AUC-G. Prolactin levels were higher in breastfeeding women (median:34.98 μg/L) than in non lactating women (median:12.21 μg/L, p<0.001). There was a significant association between age and fasting glucose (p=0.018, r=-0.665), 2. hour glucose (p=0.049, r=0.578) in breastfeeding women. DISCUSSION In our study, we displayed prolactin was inversely correlated with HbA1c and 2. hour C peptide. Some studies in the past demonstrated that higher prolactin levels had importantly lower prevelance of type 2 diabetes. Our findings supported this situation.
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Affiliation(s)
- Hatice Ozisik
- Ege University, Faculty of Medicine, Department of Endocrinology, İzmir, Turkey.
| | - Aslı Suner
- Ege University, Faculty of Medicine, Department of Biostatistics, İzmir, Turkey
| | - Sevki Cetinkalp
- Ege University, Faculty of Medicine, Department of Endocrinology, İzmir, Turkey
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12
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Kopp W. How Western Diet And Lifestyle Drive The Pandemic Of Obesity And Civilization Diseases. Diabetes Metab Syndr Obes 2019; 12:2221-2236. [PMID: 31695465 PMCID: PMC6817492 DOI: 10.2147/dmso.s216791] [Citation(s) in RCA: 327] [Impact Index Per Article: 65.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 09/13/2019] [Indexed: 12/12/2022] Open
Abstract
Westernized populations are plagued by a plethora of chronic non-infectious degenerative diseases, termed as "civilization diseases", like obesity, diabetes, cardiovascular diseases, cancer, autoimmune diseases, Alzheimer's disease and many more, diseases which are rare or virtually absent in hunter-gatherers and other non-westernized populations. There is a growing awareness that the cause of this amazing discrepancy lies in the profound changes in diet and lifestyle during recent human history. This paper shows that the transition from Paleolithic nutrition to Western diets, along with lack of corresponding genetic adaptations, cause significant distortions of the fine-tuned metabolism that has evolved over millions of years of human evolution in adaptation to Paleolithic diets. With the increasing spread of Western diet and lifestyle worldwide, overweight and civilization diseases are also rapidly increasing in developing countries. It is suggested that the diet-related key changes in the developmental process include an increased production of reactive oxygen species and oxidative stress, development of hyperinsulinemia and insulin resistance, low-grade inflammation and an abnormal activation of the sympathetic nervous system and the renin-angiotensin system, all of which play pivotal roles in the development of diseases of civilization. In addition, diet-related epigenetic changes and fetal programming play an important role. The suggested pathomechanism is also able to explain the well-known but not completely understood close relationship between obesity and the wide range of comorbidities, like type 2 diabetes mellitus, cardiovascular disease, etc., as diseases of the same etiopathology. Changing our lifestyle in accordance with our genetic makeup, including diet and physical activity, may help prevent or limit the development of these diseases.
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Affiliation(s)
- Wolfgang Kopp
- Retired Head, Diagnostikzentrum Graz, Graz8043, Austria
- Correspondence: Wolfgang Kopp Mariatrosterstraße 41, Graz8043, Austria Email
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13
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Hu Y, Liu J, Yuan Y, Chen J, Cheng S, Wang H, Xu Y. Sodium butyrate mitigates type 2 diabetes by inhibiting PERK-CHOP pathway of endoplasmic reticulum stress. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2018; 64:112-121. [PMID: 30342372 DOI: 10.1016/j.etap.2018.09.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 08/21/2018] [Accepted: 09/04/2018] [Indexed: 06/08/2023]
Abstract
Sodium butyrate (NaB), a histone deacetylase (HDAC) inhibitors, has been reported to attenuate hyperglycemia in rats. Our objective was to explore the effect and underlying mechanism of NaB on islet β-cell dysfunction and apoptosis in type 2 diabetic (T2DM) rats. T2DM models were induced by the combination of streptozotocin (STZ, 40 mg/kg) and high-fat-diet, while NaB (500 mg/kg/d) was intraperitoneally injected for 6 weeks in experimental groups. Our results suggested NaB mitigated hyperglycemia, lowered the levels of serum cholestenone (TC) and low-density lipoprotein (LDL-c), prevented body weight loss, and enhanced insulin resistance and glucose tolerance. NaB also improved diabetes-induced histological alteration of islet and functional damage; moreover, results of TUNEL and western blotting indicated NaB alleviated β-cell apoptosis. Further research showed NaB down-regulated the expression of endoplasmic reticulum stress (ERS) related proteins, including phosphorylated type I transmembrane ER-resident protein kinase (p-PERK), phosphorylated eukaryotic initiation factor 2α (p-eIF2α), activating transcription factor (ATF4) and CCAAT/enhancer-binding protein homologous protein (CHOP). Consequently, NaB mitigates type 2 diabetes by inhibiting PERK-CHOP pathway of ERS.
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Affiliation(s)
- Yimeng Hu
- Department of Metabolism, Renmin Hospital of Wuhan University, Wuhan, Hubei, 430060, China; Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China
| | - Jie Liu
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China
| | - Yin Yuan
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China
| | - Jing Chen
- Department of Integrated Wards, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China
| | - Siyuan Cheng
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China
| | - Huawei Wang
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China
| | - Yancheng Xu
- Department of Endocrinology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China.
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14
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Jeong DE, Heo S, Han JH, Lee EY, Kulkarni RN, Kim W. Glucose Controls the Expression of Polypyrimidine Tract-Binding Protein 1 via the Insulin Receptor Signaling Pathway in Pancreatic β Cells. Mol Cells 2018; 41:909-916. [PMID: 30165730 PMCID: PMC6199568 DOI: 10.14348/molcells.2018.0147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 08/06/2018] [Accepted: 08/09/2018] [Indexed: 01/04/2023] Open
Abstract
In pancreatic β cells, glucose stimulates the biosynthesis of insulin at transcriptional and post-transcriptional levels. The RNA-binding protein, polypyrimidine tract-binding protein 1 (PTBP1), also named hnRNP I, acts as a critical mediator of insulin biosynthesis through binding to the pyrimidine-rich region in the 3'-untranslated region (UTR) of insulin mRNA. However, the underlying mechanism that regulates its expression in β cells is unclear. Here, we report that glucose induces the expression of PTBP1 via the insulin receptor (IR) signaling pathway in β cells. PTBP1 is present in β cells of both mouse and monkey, where its levels are increased by glucose and insulin, but not by insulin-like growth factor 1. PTBP1 levels in immortalized β cells established from wild-type (βIRWT) mice are higher than levels in β cells established from IR-null (βIRKO) mice, and ectopic re-expression of IR-WT in βIRKO cells restored PTBP1 levels. However, PTBP1 levels were not altered in βIRKO cells transfected with IR-3YA, in which the Tyr1158/1162/1163 residues are substituted with Ala. Consistently, treatment with glucose or insulin elevated PTBP1 levels in βIRWT cells, but not in βIRKO cells. In addition, silencing Akt significantly lowered PTBP1 levels. Thus, our results identify insulin as a pivotal mediator of glucose-induced PTBP1 expression in pancreatic β cells.
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Affiliation(s)
- Da Eun Jeong
- Department of Molecular Science and Technology, Ajou University, Suwon 16499,
Korea
| | - Sungeun Heo
- Department of Molecular Science and Technology, Ajou University, Suwon 16499,
Korea
| | - Ji Hye Han
- Department of Molecular Science and Technology, Ajou University, Suwon 16499,
Korea
| | - Eun-young Lee
- Department of Molecular Science and Technology, Ajou University, Suwon 16499,
Korea
| | - Rohit N. Kulkarni
- Department of Islet Cell and Regenerative Biology, Joslin Diabetes Center and Department of Medicine, Harvard Medical School, and Harvard Stem Cell Institute, Boston, MA 02215,
USA
| | - Wook Kim
- Department of Molecular Science and Technology, Ajou University, Suwon 16499,
Korea
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15
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Carnagarin R, Matthews VB, Herat LY, Ho JK, Schlaich MP. Autonomic Regulation of Glucose Homeostasis: a Specific Role for Sympathetic Nervous System Activation. Curr Diab Rep 2018; 18:107. [PMID: 30232652 DOI: 10.1007/s11892-018-1069-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
PURPOSE OF REVIEW Cardiometabolic disorders such as obesity, metabolic syndrome and diabetes are increasingly common and associated with adverse cardiovascular outcomes. The mechanisms driving these developments are incompletely understood but likely to include autonomic dysregulation. The latest evidence for such a role is briefly reviewed here. RECENT FINDINGS Recent findings highlight the relevance of autonomic regulation in glucose metabolism and identify sympathetic activation, in concert with parasympathetic withdrawal, as a major contributor to the development of metabolic disorders and an important mediator of the associated adverse cardiovascular consequences. Methods targeting sympathetic overactivity using pharmacological and device-based approaches are available and appear as logical additional approaches to curb the burden of metabolic disorders and alleviate the associated morbidity from cardiovascular causes. While the available data are encouraging, the role of therapeutic inhibition of sympathetic overdrive in the prevention of the metabolic disorders and the associated adverse outcomes requires adequate testing in properly sized randomised controlled trials.
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Affiliation(s)
- Revathy Carnagarin
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Vance B Matthews
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Lakshini Y Herat
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Jan K Ho
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia
| | - Markus P Schlaich
- Dobney Hypertension Centre, School of Medicine - Royal Perth Hospital Unit / Medical Research Foundation, University of Western Australia, Level 3, MRF Building, Rear 50 Murray St, Perth, WA, 6000, Australia.
- Departments of Cardiology and Nephrology, Royal Perth Hospital, Perth, Australia.
- Neurovascular Hypertension & Kidney Disease Laboratory, Baker Heart and Diabetes Institute, Melbourne, Australia.
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16
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Singh A, Gibert Y, Dwyer KM. The adenosine, adrenergic and opioid pathways in the regulation of insulin secretion, beta cell proliferation and regeneration. Pancreatology 2018; 18:615-623. [PMID: 29937364 DOI: 10.1016/j.pan.2018.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/25/2018] [Accepted: 06/19/2018] [Indexed: 02/07/2023]
Abstract
Insulin, a key hormone produced by pancreatic beta cells precisely regulates glucose metabolism in vertebrates. In type 1 diabetes, the beta cell mass is destroyed, a process triggered by a combination of environmental and genetic factors. This ultimately results in absolute insulin deficiency and dysregulated glucose metabolism resulting in a number of detrimental pathophysiological effects. The traditional focus of treating type 1 diabetes has been to control blood sugar levels through the administration of exogenous insulin. Newer approaches aim to replace the beta cell mass through pancreatic or islet transplantation. Type 2 diabetes results from a relative insulin deficiency for the prevailing insulin resistance. Treatments are generally aimed at reducing insulin resistance and/or augmenting insulin secretion and the use of insulin itself is often required. It is increasingly being recognized that the beta cell mass is dynamic and increases insulin secretion in response to beta cell mitogens and stress signals to maintain glycemia within a very narrow physiological range. This review critically discusses the role of adrenergic, adenosine and opioid pathways and their interrelationship in insulin secretion, beta cell proliferation and regeneration.
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Affiliation(s)
- Amitoj Singh
- Deakin University, School of Medicine, Faculty of Health, 75 Pigdons Rd, Waurn Ponds, Geelong, VIC, 3216, Australia
| | - Yann Gibert
- Deakin University, School of Medicine, Faculty of Health, 75 Pigdons Rd, Waurn Ponds, Geelong, VIC, 3216, Australia
| | - Karen M Dwyer
- Deakin University, School of Medicine, Faculty of Health, 75 Pigdons Rd, Waurn Ponds, Geelong, VIC, 3216, Australia.
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17
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Kopp W. Diet-Induced Hyperinsulinemia as a Key Factor in the Etiology of Both Benign Prostatic Hyperplasia and Essential Hypertension? Nutr Metab Insights 2018; 11:1178638818773072. [PMID: 30455570 PMCID: PMC6238249 DOI: 10.1177/1178638818773072] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 04/04/2018] [Indexed: 01/09/2023] Open
Abstract
Benign prostatic hyperplasia and hypertension are common age-related comorbidities. Although the etiology of benign prostatic hyperplasia (BPH) is still largely unresolved and poorly understood, a significant age-independent association was found between BPH and hypertension, indicating a common pathophysiological factor for both diseases. It has previously been suggested that the development of essential hypertension may be related to diet-induced hyperinsulinemia. This study follows the question, whether BPH may develop due to the same mechanism, thereby explaining the well-known comorbidity of these 2 disorders. The scientific evidence presented shows that BPH and hypertension share the same pathophysiological changes, with hyperinsulinemia as the driving force. It further shows that significant dietary changes during human history cause disruption of a finely tuned metabolic balance that has evolved over millions of years of evolution: high-insulinemic food, typical of current “Western” diets, has the potential to cause hyperinsulinemia and insulin resistance, as well as an abnormally increased activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system, alterations that play a pivotal role in the pathogenesis of BPH and hypertension.
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Affiliation(s)
- Wolfgang Kopp
- Former head of the Diagnostikzentrum Graz, Graz, Austria
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18
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Tuo Y, Xiang M. mTOR: A double‐edged sword for diabetes. J Leukoc Biol 2018; 106:385-395. [DOI: 10.1002/jlb.3mr0317-095rr] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 09/05/2017] [Accepted: 09/14/2017] [Indexed: 12/14/2022] Open
Affiliation(s)
- Yali Tuo
- Department of PharmacologySchool of PharmacyTongji Medical CollegeHuazhong University of Science and Technology Wuhan China
| | - Ming Xiang
- Department of PharmacologySchool of PharmacyTongji Medical CollegeHuazhong University of Science and Technology Wuhan China
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19
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The pathological role of advanced glycation end products-downregulated heat shock protein 60 in islet β-cell hypertrophy and dysfunction. Oncotarget 2018; 7:23072-87. [PMID: 27056903 PMCID: PMC5029611 DOI: 10.18632/oncotarget.8604] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 03/29/2016] [Indexed: 01/09/2023] Open
Abstract
Heat shock protein 60 (HSP60) is a mitochondrial chaperone. Advanced glycation end products (AGEs) have been shown to interfere with the β-cell function. We hypothesized that AGEs induced β-cell hypertrophy and dysfunction through a HSP60 dysregulation pathway during the stage of islet/β-cell hypertrophy of type-2-diabetes. We investigated the role of HSP60 in AGEs-induced β-cell hypertrophy and dysfunction using the models of diabetic mice and cultured β-cells. Hypertrophy, increased levels of p27Kip1, AGEs, and receptor for AGEs (RAGE), and decreased levels of HSP60, insulin, and ATP content were obviously observed in pancreatic islets of 12-week-old db/db diabetic mice. Low-concentration AGEs significantly induced the cell hypertrophy, increased the p27Kip1 expression, and decreased the HSP60 expression, insulin secretion, and ATP content in cultured β-cells, which could be reversed by RAGE neutralizing antibody. HSP60 overexpression significantly reversed AGEs-induced hypertrophy, dysfunction, and ATP reduction in β-cells. Oxidative stress was also involved in the AGEs-decreased HSP60 expression in β-cells. Pancreatic sections from diabetic patient showed islet hypertrophy, increased AGEs level, and decreased HSP60 level as compared with normal subject. These findings highlight a novel mechanism by which a HSP60-correlated signaling pathway contributes to the AGEs-RAGE axis-induced β-cell hypertrophy and dysfunction under diabetic hyperglycemia.
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20
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Moullé VS, Ghislain J, Poitout V. Nutrient regulation of pancreatic β-cell proliferation. Biochimie 2017; 143:10-17. [PMID: 28987628 DOI: 10.1016/j.biochi.2017.09.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 09/28/2017] [Indexed: 12/17/2022]
Abstract
Excess consumption of energy-dense foods combined with a sedentary lifestyle is driving an obesity epidemic. Although obesity is closely associated with insulin resistance, most individuals meet the insulin demand by increasing their functional β-cell mass. Those who eventually develop type 2 diabetes are distinguished by a failure in this compensatory process. Although a causal role of insulin resistance in compensatory β-cell responses has received considerable experimental support, precisely how the β cell senses changes in the metabolic environment is still unknown. As metabolism of glucose, lipids and amino acids is profoundly altered in obesity, it is not surprising that these nutrients are conspicuous among the factors proposed to contribute. In this review we summarise our understanding of the role of nutrients, in particular glucose, fatty acids and amino acids in β-cell compensation with a particular emphasis on their relation to insulin resistance-induced factors and their underlying mechanism of action. Finally, we describe the concept of epigenetic programming and review recent studies illustrating how the status of the β cell epigenome is a product of its nutrient environment, and how metabolic programming of the β cell contributes to diabetes risk.
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Affiliation(s)
- Valentine S Moullé
- Montreal Diabetes Research Center, University of Montreal, QC, Canada; CRCHUM, University of Montreal, QC, Canada.
| | - Julien Ghislain
- Montreal Diabetes Research Center, University of Montreal, QC, Canada; CRCHUM, University of Montreal, QC, Canada.
| | - Vincent Poitout
- Montreal Diabetes Research Center, University of Montreal, QC, Canada; CRCHUM, University of Montreal, QC, Canada; Department of Medicine, University of Montreal, QC, Canada; Department of Biochemistry and Molecular Medicine, University of Montreal, QC, Canada.
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21
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Moullé VS, Vivot K, Tremblay C, Zarrouki B, Ghislain J, Poitout V. Glucose and fatty acids synergistically and reversibly promote beta cell proliferation in rats. Diabetologia 2017; 60:879-888. [PMID: 28078385 PMCID: PMC5376373 DOI: 10.1007/s00125-016-4197-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 12/08/2016] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS The mechanisms underlying pancreatic islet mass expansion have attracted considerable interest as potential therapeutic targets to prevent or delay the onset of type 2 diabetes. While several factors promoting beta cell proliferation have been identified, in the context of nutrient excess the roles of glucose or NEFA in relation to insulin resistance remain unclear. Here we tested the hypothesis that glucose and NEFA synergistically and reversibly promote beta cell proliferation in the context of nutrient-induced insulin resistance. METHODS Using 72 h infusions of glucose (GLU) or the oleate-enriched lipid emulsion ClinOleic (CLI), singly or in combination, we assessed beta cell proliferation, islet mass and insulin sensitivity in male Lewis rats. The effects of nutrients and endogenous circulating factors were examined in isolated and transplanted islets. Reversibility was studied 3 and 6 days after the end of the infusion. RESULTS GLU infusions modestly stimulated beta cell proliferation, CLI alone had no effect and GLU+CLI infusions markedly stimulated beta cell proliferation. Insulin sensitivity was equally decreased in GLU and GLU+CLI infusions. GLU+CLI infusions also stimulated beta cell proliferation in islets transplanted under the kidney capsule, albeit to a lesser extent compared with endogenous islets. Ex vivo, the combination of glucose and NEFA enhanced beta cell proliferation in rat and human islets independently from secreted insulin, and serum from GLU+CLI-infused rats potentiated the effect of glucose. Glucose tolerance, beta cell proliferation and islet mass were all restored to normal levels 6 days after termination of the infusion. CONCLUSIONS/INTERPRETATION Glucose and NEFA synergistically and reversibly promote beta cell proliferation in part via direct action on the beta cell and independently from secreted insulin.
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Affiliation(s)
- Valentine S Moullé
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- The University of Montreal Hospital Research Centre (CRCHUM), 900 Saint-Denis, Montreal, QC, H2X 0A9, Canada
| | - Kevin Vivot
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- The University of Montreal Hospital Research Centre (CRCHUM), 900 Saint-Denis, Montreal, QC, H2X 0A9, Canada
| | - Caroline Tremblay
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- The University of Montreal Hospital Research Centre (CRCHUM), 900 Saint-Denis, Montreal, QC, H2X 0A9, Canada
| | - Bader Zarrouki
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- The University of Montreal Hospital Research Centre (CRCHUM), 900 Saint-Denis, Montreal, QC, H2X 0A9, Canada
| | - Julien Ghislain
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada
- The University of Montreal Hospital Research Centre (CRCHUM), 900 Saint-Denis, Montreal, QC, H2X 0A9, Canada
| | - Vincent Poitout
- Montreal Diabetes Research Center, University of Montreal, Montreal, QC, Canada.
- The University of Montreal Hospital Research Centre (CRCHUM), 900 Saint-Denis, Montreal, QC, H2X 0A9, Canada.
- Department of Medicine, University of Montreal, Montreal, QC, Canada.
- Department of Biochemistry and Molecular Medicine, University of Montreal, Montreal, QC, Canada.
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22
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A Pdx-1-Regulated Soluble Factor Activates Rat and Human Islet Cell Proliferation. Mol Cell Biol 2016; 36:2918-2930. [PMID: 27620967 DOI: 10.1128/mcb.00103-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 09/02/2016] [Indexed: 12/23/2022] Open
Abstract
The homeodomain transcription factor Pdx-1 has important roles in pancreas and islet development as well as in β-cell function and survival. We previously reported that Pdx-1 overexpression stimulates islet cell proliferation, but the mechanism remains unclear. Here, we demonstrate that overexpression of Pdx-1 triggers proliferation largely by a non-cell-autonomous mechanism mediated by soluble factors. Consistent with this idea, overexpression of Pdx-1 under the control of a β-cell-specific promoter (rat insulin promoter [RIP]) stimulates proliferation of both α and β cells, and overexpression of Pdx-1 in islets separated by a Transwell membrane from islets lacking Pdx-1 overexpression activates proliferation in the untreated islets. Microarray and gene ontology (GO) analysis identified inhibin beta-B (Inhbb), an activin subunit and member of the transforming growth factor β (TGF-β) superfamily, as a Pdx-1-responsive gene. Overexpression of Inhbb or addition of activin B stimulates rat islet cell and β-cell proliferation, and the activin receptors RIIA and RIIB are required for the full proliferative effects of Pdx-1 in rat islets. In human islets, Inhbb overexpression stimulates total islet cell proliferation and potentiates Pdx-1-stimulated proliferation of total islet cells and β cells. In sum, this study identifies a mechanism by which Pdx-1 induces a soluble factor that is sufficient to stimulate both rat and human islet cell proliferation.
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23
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Doiron B, Hu W, DeFronzo RA. Beta Cell Formation in vivo Through Cellular Networking, Integration and Processing (CNIP) in Wild Type Adult Mice. Curr Pharm Biotechnol 2016; 17:376-88. [PMID: 26696016 PMCID: PMC5421132 DOI: 10.2174/1389201017666151223124031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 11/18/2015] [Accepted: 11/26/2015] [Indexed: 11/22/2022]
Abstract
Insulin replacement therapy is essential in type 1 diabetic individuals and is required in ~40-50% of type 2 diabetics during their lifetime. Prior attempts at beta cell regeneration have relied upon pancreatic injury to induce beta cell proliferation, dedifferentiation and activation of the embryonic pathway, or stem cell replacement. We report an alternative method to transform adult non-stem (somatic) cells into pancreatic beta cells. The Cellular Networking, Integration and Processing (CNIP) approach targets cellular mechanisms involved in pancreatic function in the organ’s adult state and utilizes a synergistic mechanism that integrates three important levels of cellular regulation to induce beta cell formation: (i) glucose metabolism, (ii) membrane receptor function, and (iii) gene transcription. The aim of the present study was to induce pancreatic beta cell formation in vivo in adult animals without stem cells and without dedifferentiating cells to recapitulate the embryonic pathway as previously published (1-3). Our results employing CNIP demonstrate that: (i) insulin secreting cells can be generated in adult pancreatic tissue in vivo and circumvent the problem of generating endocrine (glucagon and somatostatin) cells that exert deleterious effects on glucose homeostasis, and (ii) long-term normalization of glucose tolerance and insulin secretion can be achieved in a wild type diabetic mouse model. The CNIP cocktail has the potential to be used as a preventative or therapeutic treatment or cure for both type 1 and type 2 diabetes.
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Affiliation(s)
- Bruno Doiron
- Diabetes Division University of Texas Health Science Center 7703 Floyd Curl Drive San Antonio, Texas, 78231.
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24
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Han C, Rice MW, Cai D. Neuroinflammatory and autonomic mechanisms in diabetes and hypertension. Am J Physiol Endocrinol Metab 2016; 311:E32-41. [PMID: 27166279 PMCID: PMC4967151 DOI: 10.1152/ajpendo.00012.2016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 05/03/2016] [Indexed: 02/07/2023]
Abstract
Interdisciplinary studies in the research fields of endocrinology and immunology show that obesity-associated overnutrition leads to neuroinflammatory molecular changes, in particular in the hypothalamus, chronically causing various disorders known as elements of metabolic syndrome. In this process, neural or hypothalamic inflammation impairs the neuroendocrine and autonomic regulation of the brain over blood pressure and glucose homeostasis as well as insulin secretion, and elevated sympathetic activation has been appreciated as a critical mediator. This review describes the involved physiology and mechanisms, with a focus on glucose and blood pressure balance, and suggests that neuroinflammation employs the autonomic nervous system to mediate the development of diabetes and hypertension.
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Affiliation(s)
- Cheng Han
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York
| | - Matthew W Rice
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York
| | - Dongsheng Cai
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York
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25
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Cheng Y, Shen J, Ren W, Hao H, Xie Z, Liu J, Mu Y, Han W. Mild hyperglycemia triggered islet function recovery in streptozotocin-induced insulin-deficient diabetic rats. J Diabetes Investig 2016; 8:44-55. [PMID: 27184687 PMCID: PMC5217940 DOI: 10.1111/jdi.12540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/26/2016] [Accepted: 05/10/2016] [Indexed: 01/09/2023] Open
Abstract
Aims/Introduction Moderate elevation of glucose level has been shown to effectively promote β‐cell replication in various models in vitro and in normal rodents. Here, we aimed to test the effect of moderately elevated glucose on β‐cell mass expansion and islet function recovery in diabetic animal models. Materials and Methods A single high dose of streptozotocin was given to induce insulin‐deficient diabetes in adult male Sprague–Dawley rats. Then, 48 h after streptozotocin injection, newly diabetic rats were randomly divided into three groups: (i) no treatment to maintain hyperglycemia; (ii) daily exogenous long‐acting human insulin analog injection that maintained mild hyperglycemia (15 mmol/L < blood glucose < 18 mmol/L); (iii) daily exogenous long‐acting human insulin analog injection to restore normoglycemia (blood glucose <8 mmol/L) as a control. Islet function, β‐cell regeneration and β‐cell replication were monitored during the entire analysis period. Results A single high dose of streptozotocin induced massive loss of β‐cells, resulting in irreversible hyperglycemia. Mild hyperglycemia markedly promoted β‐cell proliferation, leading to robust β‐cell regeneration. Importantly, rats that maintained mild hyperglycemia showed nearly normal glucose‐stimulated insulin secretion, glucose disposal and random blood glucose levels, suggesting almost full restoration of the islet function. Normalization of blood glucose levels profoundly blunted β‐cell replication, regeneration and islet function recovery observed in mild hyperglycemia. Conclusions Our research provides a feasible approach to stimulate in situ β‐cell regeneration in diabetic rats, offering new perspectives for diabetes therapy.
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Affiliation(s)
- Yu Cheng
- Department of Endocrinology, Chinese PLA General Hospital, Beijing, China.,Department of Molecular Biology, Institute of Basic Medicine, School of Life Science, Chinese PLA General Hospital, Beijing, China
| | - Jing Shen
- Department of Endocrinology, Chinese PLA 309 Hospital, Beijing, China
| | | | - Haojie Hao
- Department of Molecular Biology, Institute of Basic Medicine, School of Life Science, Chinese PLA General Hospital, Beijing, China
| | - Zongyan Xie
- Department of Endocrinology, Chinese PLA General Hospital, Beijing, China.,Department of Molecular Biology, Institute of Basic Medicine, School of Life Science, Chinese PLA General Hospital, Beijing, China
| | - Jiejie Liu
- Department of Molecular Biology, Institute of Basic Medicine, School of Life Science, Chinese PLA General Hospital, Beijing, China
| | - Yiming Mu
- Department of Endocrinology, Chinese PLA General Hospital, Beijing, China
| | - Weidong Han
- Department of Molecular Biology, Institute of Basic Medicine, School of Life Science, Chinese PLA General Hospital, Beijing, China
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26
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Kwak MK, Lee MH, Park SJ, Shin SM, Liu R, Kang SO. Polyamines regulate cell growth and cellular methylglyoxal in high-glucose medium independently of intracellular glutathione. FEBS Lett 2016; 590:739-49. [PMID: 26898161 DOI: 10.1002/1873-3468.12102] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/03/2016] [Accepted: 02/15/2016] [Indexed: 12/19/2022]
Abstract
Polyamines can presumably inhibit protein glycation, when associated with the methylglyoxal inevitably produced during glycolysis. Herein, we hypothesized a nonenzymatic interaction between putrescine and methylglyoxal in putrescine-deficient or -overexpressing Dictyostelium cells in high-glucose medium, which can control methylglyoxal production. Putrescine was essentially required for growth rescue accompanying methylglyoxal detoxification when cells underwent growth defect and cell cycle G1-arrest when supplemented with high glucose. Furthermore, methylglyoxal regulation by putrescine seemed to be a parallel pathway independent of the changes in cellular glutathione content in high-glucose medium. Consequently, we suggest that Dictyostelium cells need polyamines for normal growth and cellular methylglyoxal regulation.
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Affiliation(s)
- Min-Kyu Kwak
- Laboratory of Biophysics, School of Biological Sciences, Institute of Microbiology, Seoul National University, Korea
| | - Mun-Hyoung Lee
- Laboratory of Biophysics, School of Biological Sciences, Institute of Microbiology, Seoul National University, Korea
| | - Seong-Jun Park
- Laboratory of Biophysics, School of Biological Sciences, Institute of Microbiology, Seoul National University, Korea
| | - Sang-Min Shin
- Laboratory of Biophysics, School of Biological Sciences, Institute of Microbiology, Seoul National University, Korea
| | - Rui Liu
- Laboratory of Biophysics, School of Biological Sciences, Institute of Microbiology, Seoul National University, Korea
| | - Sa-Ouk Kang
- Laboratory of Biophysics, School of Biological Sciences, Institute of Microbiology, Seoul National University, Korea
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27
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Seoane-Collazo P, Fernø J, Gonzalez F, Diéguez C, Leis R, Nogueiras R, López M. Hypothalamic-autonomic control of energy homeostasis. Endocrine 2015; 50:276-91. [PMID: 26089260 DOI: 10.1007/s12020-015-0658-y] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 06/06/2015] [Indexed: 10/23/2022]
Abstract
Regulation of energy homeostasis is tightly controlled by the central nervous system (CNS). Several key areas such as the hypothalamus and brainstem receive and integrate signals conveying energy status from the periphery, such as leptin, thyroid hormones, and insulin, ultimately leading to modulation of food intake, energy expenditure (EE), and peripheral metabolism. The autonomic nervous system (ANS) plays a key role in the response to such signals, innervating peripheral metabolic tissues, including brown and white adipose tissue (BAT and WAT), liver, pancreas, and skeletal muscle. The ANS consists of two parts, the sympathetic and parasympathetic nervous systems (SNS and PSNS). The SNS regulates BAT thermogenesis and EE, controlled by central areas such as the preoptic area (POA) and the ventromedial, dorsomedial, and arcuate hypothalamic nuclei (VMH, DMH, and ARC). The SNS also regulates lipid metabolism in WAT, controlled by the lateral hypothalamic area (LHA), VMH, and ARC. Control of hepatic glucose production and pancreatic insulin secretion also involves the LHA, VMH, and ARC as well as the dorsal vagal complex (DVC), via splanchnic sympathetic and the vagal parasympathetic nerves. Muscle glucose uptake is also controlled by the SNS via hypothalamic nuclei such as the VMH. There is recent evidence of novel pathways connecting the CNS and ANS. These include the hypothalamic AMP-activated protein kinase-SNS-BAT axis which has been demonstrated to be a key modulator of thermogenesis. In this review, we summarize current knowledge of the role of the ANS in the modulation of energy balance.
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Affiliation(s)
- Patricia Seoane-Collazo
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain.
| | - Johan Fernø
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- Department of Clinical Science, K. G. Jebsen Center for Diabetes Research, University of Bergen, 5021, Bergen, Norway
| | - Francisco Gonzalez
- Department of Surgery, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- Service of Ophthalmology, Complejo Hospitalario Universitario de Santiago de Compostela, 15706, Santiago de Compostela, Spain
| | - Carlos Diéguez
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain
| | - Rosaura Leis
- Unit of Investigation in Nutrition, Growth and Human Development of Galicia, Pediatric Department (USC), Complexo Hospitalario Universitario de Santiago (IDIS/SERGAS), Santiago de Compostela, Spain
| | - Rubén Nogueiras
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain
| | - Miguel López
- NeurObesity Group, Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782, Santiago de Compostela, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), 15706, Santiago de Compostela, Spain.
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28
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Prolonged hyperglycemia & hyperinsulinemia increases BDNF mRNA expression in the posterior ventromedial hypothalamus and the dorsomedial hypothalamus of fed female rats. Neuroscience 2015; 303:422-32. [DOI: 10.1016/j.neuroscience.2015.07.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/02/2015] [Accepted: 07/05/2015] [Indexed: 12/30/2022]
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29
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Schvartz D, Couté Y, Sanchez JC. Quantitative proteomics reveals the link between minichromosome maintenance complex and glucose-induced proliferation of rat pancreatic INS-1E β-cells. J Proteomics 2014; 108:163-70. [DOI: 10.1016/j.jprot.2014.05.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/16/2014] [Accepted: 05/19/2014] [Indexed: 12/21/2022]
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30
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Mezza T, Kulkarni RN. The regulation of pre- and post-maturational plasticity of mammalian islet cell mass. Diabetologia 2014; 57:1291-303. [PMID: 24824733 DOI: 10.1007/s00125-014-3251-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 03/24/2014] [Indexed: 12/17/2022]
Abstract
Regeneration of mature cells that produce functional insulin represents a major focus and a challenge of current diabetes research aimed at restoring beta cell mass in patients with most forms of diabetes, as well as in ageing. The capacity to adapt to diverse physiological states during life and the consequent ability to cope with increased metabolic demands in the normal regulation of glucose homeostasis is a distinctive feature of the endocrine pancreas in mammals. Both beta and alpha cells, and presumably other islet cells, are dynamically regulated via nutrient, neural and/or hormonal activation of growth factor signalling and the post-transcriptional modification of a variety of genes or via the microbiome to continually maintain a balance between regeneration (e.g. proliferation, neogenesis) and apoptosis. Here we review key regulators that determine islet cell mass at different ages in mammals. Understanding the chronobiology and the dynamics and age-dependent processes that regulate the relationship between the different cell types in the overall maintenance of an optimally functional islet cell mass could provide important insights into planning therapeutic approaches to counter and/or prevent the development of diabetes.
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Affiliation(s)
- Teresa Mezza
- Islet Cell Biology and Regenerative Medicine, Joslin Diabetes Center, 1 Joslin Place, Boston, MA, 02215, USA
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31
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Sun Y, Zhang Y, Li N, Zhang H, Zhou L, Shao L. Exposure to high levels of glucose increases the expression levels of genes involved in cholesterol biosynthesis in rat islets. Exp Ther Med 2014; 8:991-997. [PMID: 25120636 PMCID: PMC4113575 DOI: 10.3892/etm.2014.1812] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 06/05/2014] [Indexed: 02/01/2023] Open
Abstract
Cells continually adjust their gene expression profiles in order to adapt to the availability of nutrients. Glucose is a major regulator of pxancreatic β-cell function and cell growth. However, the mechanism of β-cell adaptation to high levels of glucose remains uncertain. To identify the specific targets responsible for adaptation to high levels of glucose, the differentially expressed genes from primary rat islets treated with 3.3 and 16.7 mmol/l glucose for 24 h were detected by DNA microarray. The results revealed that the expression levels of genes that encode enzymes required for de novo cholesterol biosynthesis [3-hydroxy-3-methylglutaryl-CoA synthase 1 (Hmgcs1), 3-hydroxy-3-methylglutaryl-CoA reductase (Hmgcr), mevalonate (diphospho) decarboxylase (Mvd), isopentenyl-diphosphate δ-isomerase 1 (Idi1), squalene epoxidase (Sqle) and 7-dehydrocholesterol reductase (Dhcr7)] were significantly increased in islets treated with high levels of glucose compared with those in the islets treated with lower glucose levels. Quantitative polymerase chain reaction further confirmed that glucose stimulated the expression levels of these genes in a dose- and time-dependent manner. A similar result was obtained in islets isolated from rats subjected to 12, 24, 48 and 72 h of continuous glucose infusion. It has previously been recognized that cholesterol homeostasis is important for β-cell function. The present study provides, to the best of our knowledge, the first evidence for the involvement of the de novo cholesterol biosynthesis pathway in the adaptation of rat islets to high levels of glucose in vitro and in vivo.
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Affiliation(s)
- Yixuan Sun
- Department of Geratology, East Hospital, Shanghai Tongji University, Shanghai 200120, P.R. China
| | - Yuqing Zhang
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Na Li
- Department of Gastroenterology, Central Hospital of Zibo, Zibo, Shandong 255036, P.R. China
| | - Hua Zhang
- Department of Geratology, East Hospital, Shanghai Tongji University, Shanghai 200120, P.R. China
| | - Libin Zhou
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, P.R. China
| | - Li Shao
- Department of Geratology, East Hospital, Shanghai Tongji University, Shanghai 200120, P.R. China
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32
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Li M, Maddison LA, Page-McCaw P, Chen W. Overnutrition induces β-cell differentiation through prolonged activation of β-cells in zebrafish larvae. Am J Physiol Endocrinol Metab 2014; 306:E799-807. [PMID: 24473439 PMCID: PMC3962607 DOI: 10.1152/ajpendo.00686.2013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Insulin from islet β-cells maintains glucose homeostasis by stimulating peripheral tissues to remove glucose from circulation. Persistent elevation of insulin demand increases β-cell number through self-replication or differentiation (neogenesis) as part of a compensatory response. However, it is not well understood how a persistent increase in insulin demand is detected. We have previously demonstrated that a persistent increase in insulin demand by overnutrition induces compensatory β-cell differentiation in zebrafish. Here, we use a series of pharmacological and genetic analyses to show that prolonged stimulation of existing β-cells is necessary and sufficient for this compensatory response. In the absence of feeding, tonic, but not intermittent, pharmacological activation of β-cell secretion was sufficient to induce β-cell differentiation. Conversely, drugs that block β-cell secretion, including an ATP-sensitive potassium (K ATP) channel agonist and an L-type Ca(2+) channel blocker, suppressed overnutrition-induced β-cell differentiation. Genetic experiments specifically targeting β-cells confirm existing β-cells as the overnutrition sensor. First, inducible expression of a constitutively active K ATP channel in β-cells suppressed the overnutrition effect. Second, inducible expression of a dominant-negative K ATP mutant induced β-cell differentiation independent of nutrients. Third, sensitizing β-cell metabolism by transgenic expression of a hyperactive glucokinase potentiated differentiation. Finally, ablation of the existing β-cells abolished the differentiation response. Taken together, these data establish that overnutrition induces β-cell differentiation in larval zebrafish through prolonged activation of β-cells. These findings demonstrate an essential role for existing β-cells in sensing overnutrition and compensating for their own insufficiency by recruiting additional β-cells.
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Affiliation(s)
- Mingyu Li
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
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33
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Alismail H, Jin S. Microenvironmental stimuli for proliferation of functional islet β-cells. Cell Biosci 2014; 4:12. [PMID: 24594290 PMCID: PMC3974598 DOI: 10.1186/2045-3701-4-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 01/29/2014] [Indexed: 12/31/2022] Open
Abstract
Diabetes is characterized by high blood glucose level due to either autoimmune destruction of islet β-cells or insufficient insulin secretion or glucose non-responsive production of insulin by β-cells. It is highly desired to replace biological functional β-cells for the treatment of diabetes. Unfortunately, β-cells proliferate with an extremely low rate. This cellular property hinders cell-based therapy for clinical application. Many attempts have been made to develop techniques that allow production of large quantities of clinically relevant islet β-cells in vitro. A line of studies evidently demonstrate that β-cells can proliferate under certain circumstances, giving the hopes for generating and expanding these cells in vitro and transplanting them to the recipient. In this review, we discuss the requirements of microenvironmental stimuli that stimulate β-cell proliferation in cell cultures. We highlight advanced approaches for augmentation of β-cell expansion that have recently emerged in this field. Furthermore, knowing the signaling pathways and molecular mechanisms would enable manipulating cell proliferation and optimizing its insulin secretory function. Thus, signaling pathways involved in the enhancement of cell proliferation are discussed as well.
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Affiliation(s)
| | - Sha Jin
- Department of Bioengineering, Thomas J, Watson School of Engineering and Applied Sciences, State University of New York in Binghamton, Binghamton, NY 13902, USA.
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34
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Tsui S, Dai W, Lu L. CCCTC-binding factor mediates effects of glucose on beta cell survival. Cell Prolif 2013; 47:28-37. [PMID: 24354619 DOI: 10.1111/cpr.12085] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 10/07/2013] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES Pancreatic islet β-cell survival is paramount for regulation of insulin activity and for maintaining glucose homeostasis. Recently, Pax6 has been shown to be essential for many vital functions in β-cells, although many molecular mechanisms of its homeostasis in β-cells remain unclear. The present study investigates novel effects of glucose- and insulin-induced CCCTC-binding factor (CTCF) activity on Pax6 gene expression as well as for subsequent effects of insulin-activated signalling pathways, on β-cell proliferation. MATERIALS AND METHODS Pancreatic β-TC-1-6 cells were cultured in DMEM and stimulated with high concentrations of glucose (5-125 mm); cell viability was assessed by MTT assay. Effects of CTCF on Pax6 were evaluated in the high glucose-induced environment and CTCF/Erk-suppressed cells, by promoter reporter and western blotting analyses. RESULTS Increases in glucose and insulin concentrations upregulated CTCF and consequently downregulated Pax6 in β-cell survival and proliferation. Knocking-down CTCF directly affected Pax6 transcription through CTCF binding and blocked the response to glucose. Altered Erk activity mediated effects of CTCF on controlling Pax6 expression, which partially regulated β-cell proliferation. CONCLUSIONS CTCF functioned as a molecular mediator between insulin-induced upstream Erk signalling and Pax6 expression in these pancreatic β-cells. This pathway may contribute to regulation of β-cell survival and proliferation.
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Affiliation(s)
- S Tsui
- Department of Medicine, David Geffen School of Medicine University of California Los Angeles, Torrance, CA, 90502, USA
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35
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Cerf ME. Beta cell dynamics: beta cell replenishment, beta cell compensation and diabetes. Endocrine 2013; 44:303-11. [PMID: 23483434 DOI: 10.1007/s12020-013-9917-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 03/01/2013] [Indexed: 12/19/2022]
Abstract
Type 2 diabetes, characterized by persistent hyperglycemia, arises mostly from beta cell dysfunction and insulin resistance and remains a highly complex metabolic disease due to various stages in its pathogenesis. Glucose homeostasis is primarily regulated by insulin secretion from the beta cells in response to prevailing glycemia. Beta cell populations are dynamic as they respond to fluctuating insulin demand. Beta cell replenishment and death primarily regulate beta cell populations. Beta cells, pancreatic cells, and extra-pancreatic cells represent the three tiers for replenishing beta cells. In rodents, beta cell self-replenishment appears to be the dominant source for new beta cells supported by pancreatic cells (non-beta islet cells, acinar cells, and duct cells) and extra-pancreatic cells (liver, neural, and stem/progenitor cells). In humans, beta cell neogenesis from non-beta cells appears to be the dominant source of beta cell replenishment as limited beta cell self-replenishment occurs particularly in adulthood. Metabolic states of increased insulin demand trigger increased insulin synthesis and secretion from beta cells. Beta cells, therefore, adapt to support their physiology. Maintaining physiological beta cell populations is a strategy for targeting metabolic states of persistently increased insulin demand as in diabetes.
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Affiliation(s)
- Marlon E Cerf
- Diabetes Discovery Platform, South African Medical Research, PO Box 19070, Tygerberg, 7505, South Africa,
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36
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Taylor BL, Liu FF, Sander M. Nkx6.1 is essential for maintaining the functional state of pancreatic beta cells. Cell Rep 2013; 4:1262-75. [PMID: 24035389 DOI: 10.1016/j.celrep.2013.08.010] [Citation(s) in RCA: 232] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 07/11/2013] [Accepted: 08/05/2013] [Indexed: 02/06/2023] Open
Abstract
Recently, loss of beta-cell-specific traits has been proposed as an early cause of beta cell failure in diabetes. However, the molecular mechanisms that underlie the loss of beta cell features remain unclear. Here, we identify an Nkx6.1-controlled gene regulatory network as essential for maintaining the functional and molecular traits of mature beta cells. Conditional Nkx6.1 inactivation in adult mice caused rapid-onset diabetes and hypoinsulinemia. Genome-wide analysis of Nkx6.1-regulated genes and functional assays further revealed a critical role for Nkx6.1 in the control of insulin biosynthesis, insulin secretion, and beta cell proliferation. Over time, Nkx6.1-deficient beta cells acquired molecular characteristics of delta cells, revealing a molecular link between impaired beta cell functional properties and loss of cell identity. Given that Nkx6.1 levels are reduced in human type 2 diabetic beta cells, our study lends support to the concept that loss of beta cell features could contribute to the pathogenesis of diabetes.
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Affiliation(s)
- Brandon L Taylor
- Departments of Pediatrics and Cellular and Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093-0695, USA
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37
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Lee BW, Kim MH, Chae HY, Hwang HJ, Kang D, Ihm SH. Enhanced gene transfer to pancreatic islets using glucagon-like peptide-1. Transplant Proc 2013; 45:591-6. [PMID: 23498795 DOI: 10.1016/j.transproceed.2012.10.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 09/21/2012] [Accepted: 10/30/2012] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The efficient transfer of genes into intact islets is difficult since islets exist as clusters of differentiated cells with little replication potential. Cell proliferation in response to growth factors is known to be accompanied by loosening of cell-to-cell contacts and increasing paracellular permeability. In this study, we investigated whether gene delivery into intact islet cells was facilitated by modulating β-cell proliferation. METHODS Isolated rat islets were pretreated with glucagon-like peptide (GLP)-1 or human growth hormone for 24 hours, or with 300 mg/dL of glucose for 48 hours before transduction with a suboptimal dose of recombinant adenoviral vector expressing green fluorescent protein (GFP) and β-galactosidase (multiplicity of infection of 25). Transduction efficiency was assessed by measuring β-galactosidase activity and GFP expression using enzyme-linked immunosorbent assay, flow cytometry, and fluorescence microscopy. The numbers of 7-aminoactinomycin D-positive dead cells and 5-ethynyl-2-deoxyuridine (EdU)-positive proliferating cells were also monitored using flow cytometry and fluorescence microscopy. RESULTS The transduction efficiency of rat islet cells by a suboptimal dose of viral vector was significantly improved by GLP-1 pretreatment, accompanied by enhanced cell viability and cell proliferation. An increased GFP expression in islet cells after GLP-1 pretreatment was observed among the increased numbers of EdU-positive proliferating cells. CONCLUSION Pretreatment of rat islets with GLP-1 enhanced the transduction efficiency of an adenoviral vector, reducing viral dose burden while improving islet cell viability. From a therapeutic standpoint, genetic modification of pancreatic islets combined with GLP-1 pretreatment may be a promising option for ex vivo gene therapy prior to islet transplantation.
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Affiliation(s)
- B W Lee
- Department of Internal Medicine, Hallym University College of Medicine, Chuncheon, Korea
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38
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Yi P, Park JS, Melton DA. Betatrophin: a hormone that controls pancreatic β cell proliferation. Cell 2013; 153:747-58. [PMID: 23623304 DOI: 10.1016/j.cell.2013.04.008] [Citation(s) in RCA: 351] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 03/28/2013] [Accepted: 04/02/2013] [Indexed: 12/22/2022]
Abstract
Replenishing insulin-producing pancreatic β cell mass will benefit both type I and type II diabetics. In adults, pancreatic β cells are generated primarily by self-duplication. We report on a mouse model of insulin resistance that induces dramatic pancreatic β cell proliferation and β cell mass expansion. Using this model, we identify a hormone, betatrophin, that is primarily expressed in liver and fat. Expression of betatrophin correlates with β cell proliferation in other mouse models of insulin resistance and during gestation. Transient expression of betatrophin in mouse liver significantly and specifically promotes pancreatic β cell proliferation, expands β cell mass, and improves glucose tolerance. Thus, betatrophin treatment could augment or replace insulin injections by increasing the number of endogenous insulin-producing cells in diabetics.
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Affiliation(s)
- Peng Yi
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
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39
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Yi P, Park JS, Melton DA. Betatrophin: a hormone that controls pancreatic β cell proliferation. Cell 2013. [PMID: 23623304 DOI: 10.1016/j.cell] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Replenishing insulin-producing pancreatic β cell mass will benefit both type I and type II diabetics. In adults, pancreatic β cells are generated primarily by self-duplication. We report on a mouse model of insulin resistance that induces dramatic pancreatic β cell proliferation and β cell mass expansion. Using this model, we identify a hormone, betatrophin, that is primarily expressed in liver and fat. Expression of betatrophin correlates with β cell proliferation in other mouse models of insulin resistance and during gestation. Transient expression of betatrophin in mouse liver significantly and specifically promotes pancreatic β cell proliferation, expands β cell mass, and improves glucose tolerance. Thus, betatrophin treatment could augment or replace insulin injections by increasing the number of endogenous insulin-producing cells in diabetics.
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Affiliation(s)
- Peng Yi
- Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
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Nollevaux MC, Rahier J, Marchandise J, Thurion P, Godecharles S, Van den Steen G, Jamart J, Sempoux C, Jacquemin P, Guiot Y. Characterization of β-cell plasticity mechanisms induced in mice by a transient source of exogenous insulin. Am J Physiol Endocrinol Metab 2013; 304:E711-23. [PMID: 23403947 PMCID: PMC3625751 DOI: 10.1152/ajpendo.00304.2012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
β-Cell plasticity governs the adjustment of β-cell mass and function to ensure normoglycemia. The study of how β-cell mass is controlled and the identification of alternative sources of β-cells are active fields of research. β-Cell plasticity has been implicated in numerous physiological and pathological conditions. We developed a mice model in which we induced major β-cell mass atrophy by implanting insulin pellets (IPI) for 7 or 10 days. The implants were then removed (IPR) to observe the timing and characteristics of β-cell regeneration in parallel to changes in glycemia. Following IPR, the endocrine mass was reduced by 60% at day 7 and by 75% at day 10, and transient hyperglycemia was observed, which resolved within 1 wk. Five days after IPR, enhanced β-cell proliferation and an increased frequency of small islets were observed in 7-day IPI mice. β-Cell mass was fully restored after an additional 2 days. For the 10-day IPI group, β-cell and endocrine mass were no longer significantly different from those of the control group at 2 wk post-IPR. Furthermore, real-time quantitative PCR analysis of endocrine structures isolated by laser capture microdissection indicated sequentially enhanced expression of the pancreatic transcription factors β(2)/NeuroD and Pdx-1 post-IPR. Thus, our data suggest this mouse model of β-cell plasticity not only relies on replication but also involves enhanced cell differentiation plasticity.
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Affiliation(s)
- M-C Nollevaux
- Service d’Anatomie Pathologique, CHU Mont-Godinne, Institut de recherche expérimentale et clinique, Université catholique de Louvain, Yvoir, Brussels, Belgium.
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41
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Osto M, Zini E, Reusch CE, Lutz TA. Diabetes from humans to cats. Gen Comp Endocrinol 2013; 182:48-53. [PMID: 23247272 DOI: 10.1016/j.ygcen.2012.11.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 11/27/2012] [Accepted: 11/30/2012] [Indexed: 01/04/2023]
Abstract
Diabetes mellitus is a common endocrinopathy in humans and in cats. The general prevalence of diabetes mellitus, and in particular of type 2 diabetes, has risen dramatically in recent years. This increase has often been linked to the rise in the obesity pandemic because obesity and the ensuing metabolic consequences constitute major risk factors for human type 2 and for feline diabetes. Feline diabetes shares many features of human type 2 diabetes in respect to its pathophysiology, underlying risk factors and treatment strategies. This review will briefly summarize major characteristics in the human and the feline disease and where available, point out the current knowledge on similarities and differences.
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Affiliation(s)
- M Osto
- Vetsuisse Faculty, Institute of Veterinary Physiology, University of Zurich, Switzerland.
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42
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Abstract
Beta cell dysfunction and insulin resistance are inherently complex with their interrelation for triggering the pathogenesis of diabetes also somewhat undefined. Both pathogenic states induce hyperglycemia and therefore increase insulin demand. Beta cell dysfunction results from inadequate glucose sensing to stimulate insulin secretion therefore elevated glucose concentrations prevail. Persistently elevated glucose concentrations above the physiological range result in the manifestation of hyperglycemia. With systemic insulin resistance, insulin signaling within glucose recipient tissues is defective therefore hyperglycemia perseveres. Beta cell dysfunction supersedes insulin resistance in inducing diabetes. Both pathological states influence each other and presumably synergistically exacerbate diabetes. Preserving beta cell function and insulin signaling in beta cells and insulin signaling in the glucose recipient tissues will maintain glucose homeostasis.
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Affiliation(s)
- Marlon E. Cerf
- Diabetes Discovery Platform, South African Medical Research CouncilCape Town, South Africa
- *Correspondence: Marlon E. Cerf, Diabetes Discovery Platform, South African Medical Research Council, PO Box 19070, Tygerberg, Cape Town 7505, South Africa. e-mail:
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Jones HB, Bigley AL, Pemberton J, Randall KJ. Quantitative histopathological assessment of retardation of islets of langerhans degeneration in rosiglitazone-dosed obese ZDF rats using combined insulin and collagens (I and III) immunohistochemistry with automated image analysis and statistical modeling. Toxicol Pathol 2012; 41:425-44. [PMID: 23047688 DOI: 10.1177/0192623312460923] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Islets of Langerhans represent a heterogeneous population in insulin resistant and diabetic animals and humans as histological appearances and function vary substantially. Mathematical representation that reflects this morphological diversity will assist in assessment of degeneration and regeneration, enabling comparisons between species, strains, and experimental investigations. Our investigative approach used a model of islet degeneration in diabetic male obese Zucker Diabetic Fatty (ZDF) rats and evaluated its prevention using rosiglitazone treatment. Immunohistochemical staining (insulin and collagens I/III) with automated image analysis reliably measured numbers, area, clustering, and staining intensity of β-cells and degree of islet fibrosis. Finite mixture mathematical modeling for the joint probability distribution of seven islet parameters to represent islet numerical data variation provided an automatic procedure for islet category allocations as normal or abnormal. Allocations for obese ZDF controls and rosiglitazone-treated animals were significantly different, with no significant difference between the latter and lean ZDF controls, indicative of differences within islet populations of individual animals, between lean and obese rat strains and following drug treatment. Islet morphology showed clear association with mathematical characterization. Information on islet morphology obtained by histopathological assessment of single pancreatic tissue sections was confirmed by this method showing drug-induced retardation of islet of Langerhans degeneration.
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Affiliation(s)
- Huw B Jones
- Pathology Group, Global Safety Assessment, Alderley Park, Macclesfield, Cheshire, United Kingdom.
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44
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Schreiber AK, Neufeld M, Jesus CHA, Cunha JM. Peripheral antinociceptive effect of anandamide and drugs that affect the endocannabinoid system on the formalin test in normal and streptozotocin-diabetic rats. Neuropharmacology 2012; 63:1286-97. [PMID: 22959964 DOI: 10.1016/j.neuropharm.2012.08.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 07/26/2012] [Accepted: 08/14/2012] [Indexed: 10/27/2022]
Abstract
Diabetes is often associated with painful neuropathy. The current treatments are symptomatic and ineffective. Cannabinoids have been proposed as promising drugs for chronic pain treatment and its antinociceptive effect has already been related in nerve injury models of neuropathic pain, but little has been investigated in painful diabetic neuropathy models. Thus, the current study aims to investigate the potential antinociceptive effect of drugs that alter endocannabinoid system when injected subcutaneously into the dorsal surface of the ipsilateral hind paw in chemical hyperalgesia induced by formalin in both normoglycemic (Ngl) and streptozotocin-diabetic (Dbt) rats. Diabetic rats exhibited exaggerated flinching behaviors during first and second phases of the formalin test, indicating the presence of hyperalgesia. AM404, an anandamide (AEA) re-uptake inhibitor, AEA (an agonist of CB1/CB2 receptors) or ACEA (a selective CB1 receptor agonist) induced antinociception in both phases of formalin test in Ngl and Dbt rats. In both groups, the antinociceptive effect of ACEA was prevented by AM251, a CB1 inverse agonist while the antinociceptive effect of AEA was prevented by AM251 or AM630, a CB2 receptor antagonist. In Ngl rats, the antinociceptive effect of AM404 was prevented by AM251 or capsazepine only during first phase of the formalin test while in Dbt rats, this effect was blocked by pretreatment with AM251 (both phases) or AM630 (second phase). Taken together, these results demonstrated broad-spectrum antinociceptive properties of cannabinoids in a model of painful diabetic neuropathy. Peripheral activation of both cannabinoid receptors seems to mediate the antinociceptive effect of exogenous or endogenous anandamide.
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Affiliation(s)
- Anne K Schreiber
- Department of Pharmacology, Biological Sciences Building, Federal University of Paraná, Curitiba 81540-990, PR, Brazil
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45
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Gunasekaran U, Hudgens CW, Wright BT, Maulis MF, Gannon M. Differential regulation of embryonic and adult β cell replication. Cell Cycle 2012; 11:2431-42. [PMID: 22659844 PMCID: PMC3404874 DOI: 10.4161/cc.20545] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Diabetes results from an inadequate functional β cell mass, either due to autoimmune destruction (Type 1 diabetes) or insulin resistance combined with β cell failure (Type 2 diabetes). Strategies to enhance β cell regeneration or increase cell proliferation could improve outcomes for patients with diabetes. Research conducted over the past several years has revealed that factors regulating embryonic β cell mass expansion differ from those regulating replication ofβ cells post-weaning. This article aims to compare and contrast factors known to control embryonic and postnatal β cell replication. In addition, we explore the possibility that connective tissue growth factor (CTGF) could increase adult β cell replication. We have already shown that CTGF is required for embryonicβ cell proliferation and is sufficient to induce replication of embryonic β cells. Here we examine whether adult β cell replication and expansion of β cell mass can be enhanced by increased CTGF expression in mature β cells.
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Affiliation(s)
- Uma Gunasekaran
- Department of Medicine, Division of Diabetes, Endocrinology and Metabolism, Vanderbilt University Medical Center, Nashville, TN, USA
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46
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Karadimos MJ, Kapoor A, El Khattabi I, Sharma A. β-cell preservation and regeneration for diabetes treatment: where are we now? ACTA ACUST UNITED AC 2012; 2:213-222. [PMID: 23049620 DOI: 10.2217/dmt.12.21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Over the last decade, our knowledge of β-cell biology has expanded with the use of new scientific techniques and strategies. Growth factors, hormones and small molecules have been shown to enhance β-cell proliferation and function. Stem cell technology and research into the developmental biology of the pancreas have yielded new methods for in vivo and in vitro regeneration of β cells from stem cells and endogenous progenitors as well as transdifferentiation of non-β cells. Novel pharmacological approaches have been developed to preserve and enhance β-cell function. Strategies to increase expression of insulin gene transcription factors in dysfunctional and immature β cells have ameliorated these impairments. Hence, we suggest that strategies to minimize β-cell loss and to increase their function and regeneration will ultimately lead to therapy for both Type 1 and 2 diabetes.
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Affiliation(s)
- Michael J Karadimos
- Section of Islet Cell & Regenerative Biology, Joslin Diabetes Center, Boston, MA 02215, USA ; Department of Medicine, Harvard Medical School, Boston, MA 02215, USA
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Xie J, Herbert TP. The role of mammalian target of rapamycin (mTOR) in the regulation of pancreatic β-cell mass: implications in the development of type-2 diabetes. Cell Mol Life Sci 2012; 69:1289-304. [PMID: 22068611 PMCID: PMC11114779 DOI: 10.1007/s00018-011-0874-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 10/20/2011] [Accepted: 10/20/2011] [Indexed: 12/22/2022]
Abstract
Type-2 diabetes mellitus (T2DM) is a disorder that is characterized by high blood glucose concentration in the context of insulin resistance and/or relative insulin deficiency. It causes metabolic changes that lead to the damage and functional impairment of organs and tissues resulting in increased morbidity and mortality. It is this form of diabetes whose prevalence is increasing at an alarming rate due to the 'obesity epidemic', as obesity is a key risk factor in the development of insulin resistance. However, the majority of individuals who have insulin resistance do not develop diabetes due to a compensatory increase in insulin secretion in response to an increase in insulin demand. This adaptive response is sustained by an increase in both β-cell function and mass. Importantly, there is increasing evidence that the Serine/Threonine kinase mammalian target of rapamycin (mTOR) plays a key role in the regulation of β-cell mass and therefore likely plays a critical role in β-cell adaptation. Therefore, the primary focus of this review is to summarize our current understanding of the role of mTOR in stimulating pancreatic β-cell mass and thus, in the prevention of type-2 diabetes.
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Affiliation(s)
- Jianling Xie
- Department of Cell Physiology and Pharmacology, University of Leicester, The Henry Wellcome Building, University Road, Leicester, LE1 9HN UK
| | - Terence P. Herbert
- Department of Cell Physiology and Pharmacology, University of Leicester, The Henry Wellcome Building, University Road, Leicester, LE1 9HN UK
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48
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Gatford KL, De Blasio MJ, How TA, Harland ML, Summers-Pearce BL, Owens JA. Testing the plasticity of insulin secretion and β-cell functionin vivo: responses to chronic hyperglycaemia in the sheep. Exp Physiol 2012; 97:663-75. [DOI: 10.1113/expphysiol.2011.063560] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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49
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Zhang H, Li W, Wang Q, Wang X, Li F, Zhang C, Wu L, Long H, Liu Y, Li X, Luo M, Li G, Ning G. Glucose-mediated repression of menin promotes pancreatic β-cell proliferation. Endocrinology 2012; 153:602-11. [PMID: 22166975 DOI: 10.1210/en.2011-1460] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Menin, encoded by the Men1 gene, is responsible for β-cell tumor formation in patients with multiple endocrine neoplasia type 1. Recently, menin has been proven to negatively regulate β-cell proliferation during pregnancy. However, it is unclear whether menin is involved in pancreatic β-cell proliferation in response to other physiological replication stimuli, such as glucose. In this study, we found that the menin level was significantly reduced in high glucose-treated INS1 cells and primary rat islets, both with increased proliferation. A similar observation was found in islets isolated from rats subjected to 72-h continuous glucose infusion. The glucose-induced proliferation was inhibited by menin overexpression. Further molecular studies showed that glucose-induced menin suppression was blocked by PI3K/Akt pathway inhibitors. A major PI3K/Akt substrate, Foxo1, was shown to enhance menin transcription levels by binding the promoter region of the Men1 gene. Therefore, we conclude that glucose inhibits menin expression via the PI3K/Akt/Foxo1 pathway and hence promotes pancreatic β-cell proliferation. Our study suggests that menin might serve as an important intracellular target of glucose to mediate the mitogenic effect that glucose exerts in pancreatic β-cells.
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Affiliation(s)
- Hongli Zhang
- Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai Clinical Center for Endocrine and Metabolic Diseases, Department of Endocrinology, Ruijin Hospital, Shanghai Jiaotong University Medical School, 197 Ruijin 2nd Road, 200025, Shanghai, PR China
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50
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Tarabra E, Pelengaris S, Khan M. A simple matter of life and death-the trials of postnatal Beta-cell mass regulation. Int J Endocrinol 2012; 2012:516718. [PMID: 22577380 PMCID: PMC3346985 DOI: 10.1155/2012/516718] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 12/31/2011] [Indexed: 12/17/2022] Open
Abstract
Pancreatic beta-cells, which secrete the hormone insulin, are the key arbiters of glucose homeostasis. Defective beta-cell numbers and/or function underlie essentially all major forms of diabetes and must be restored if diabetes is to be cured. Thus, the identification of the molecular regulators of beta-cell mass and a better understanding of the processes of beta-cell differentiation and proliferation may provide further insight for the development of new therapeutic targets for diabetes. This review will focus on the principal hormones and nutrients, as well as downstream signalling pathways regulating beta-cell mass in the adult. Furthermore, we will also address more recently appreciated regulators of beta-cell mass, such as microRNAs.
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Affiliation(s)
- Elena Tarabra
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
- *Elena Tarabra:
| | - Stella Pelengaris
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
| | - Michael Khan
- School of Life Sciences, Warwick University, Gibbet Hill Road, Coventry CV4 7AL, UK
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