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Lafferty RA, Flatt PR, Irwin N. NPYR modulation: Potential for the next major advance in obesity and type 2 diabetes management? Peptides 2024; 179:171256. [PMID: 38825012 DOI: 10.1016/j.peptides.2024.171256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/13/2024] [Accepted: 05/30/2024] [Indexed: 06/04/2024]
Abstract
The approval of the glucagon-like peptide 1 (GLP-1) mimetics semaglutide and liraglutide for management of obesity, independent of type 2 diabetes (T2DM), has initiated a resurgence of interest in gut-hormone derived peptide therapies for the management of metabolic diseases, but side-effect profile is a concern for these medicines. However, the recent approval of tirzepatide for obesity and T2DM, a glucose-dependent insulinotropic polypeptide (GIP), GLP-1 receptor co-agonist peptide therapy, may provide a somewhat more tolerable option. Despite this, an increasing number of non-incretin alternative peptides are in development for obesity, and it stands to reason that other hormones will take to the limelight in the coming years, such as peptides from the neuropeptide Y family. This narrative review outlines the therapeutic promise of the neuropeptide Y family of peptides, comprising of the 36 amino acid polypeptides neuropeptide Y (NPY), peptide tyrosine-tyrosine (PYY) and pancreatic polypeptide (PP), as well as their derivatives. This family of peptides exerts a number of metabolically relevant effects such as appetite regulation and can influence pancreatic beta-cell survival. Although some of these actions still require full translation to the human setting, potential therapeutic application in obesity and type 2 diabetes is conceivable. However, like GLP-1 and GIP, the endogenous NPY, PYY and PP peptide forms are subject to rapid in vivo degradation and inactivation by the serine peptidase, dipeptidyl-peptidase 4 (DPP-4), and hence require structural modification to prolong circulating half-life. Numerous protective modification strategies are discussed in this regard herein, alongside related impact on biological activity profile and therapeutic promise.
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Affiliation(s)
- Ryan A Lafferty
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland BT52 1SA, UK.
| | - Peter R Flatt
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland BT52 1SA, UK
| | - Nigel Irwin
- Diabetes Research Centre, Ulster University, Coleraine, Northern Ireland BT52 1SA, UK
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2
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Strage EM, Ley C, Westermark GT, Tengholm A. Insulin release from isolated cat islets of Langerhans. Domest Anim Endocrinol 2024; 87:106836. [PMID: 38141375 DOI: 10.1016/j.domaniend.2023.106836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 12/18/2023] [Accepted: 12/18/2023] [Indexed: 12/25/2023]
Abstract
Feline diabetes mellitus is a common endocrine disease with increasing prevalence. It shows similarities with human type 2 diabetes and is characterized by insulin resistance and deficient insulin secretion. Moreover, cats and humans belong to the very few species that form amyloid depositions in the pancreatic islets. However, little is known about cat islet function and no studies have addressed insulin secretion from isolated islets ex vivo. The aim of this study was to establish a protocol for isolation of islets of Langerhans from pancreata of cats euthanized due to disease, and to evaluate insulin secretion responses to various physiological and pharmacological stimuli. Collagenase digestion of pancreatic tissue from 13 non-diabetic cats and two cats with diabetic ketoacidosis yielded individual islets surrounded by a layer of exocrine tissue that was reduced after two days in culture. Histological examination showed islet amyloid in pancreatic biopsies from most non-diabetic and in one diabetic cat. Islets from non-diabetic cats cultured at 5.5 mM glucose responded with increased insulin secretion to 16.7 mM glucose, 30 mM K+ and 20 µM of the sulfonylurea glipizide (2-3 times basal secretion at 3 mM glucose). The glucagon-like peptide-1 receptor agonist exendin-4 (100 nM) had no effect under basal conditions but potentiated glucose-triggered insulin release. Only one of nine islet batches from diabetic cats released detectable amounts of insulin, which was enhanced by exendin-4. Culture of islets from non-diabetic cats at 25 mM glucose impaired secretion both in response to glucose and K+ depolarization. In conclusion, we describe a procedure for isolation of islets from cat pancreas biopsies and demonstrate that isolated cat islets secrete insulin in response to glucose and antidiabetic drugs. The study provides a basis for future ex vivo studies of islet function relevant to the understanding of the pathophysiology and treatment of feline diabetes.
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Affiliation(s)
- Emma M Strage
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, P.O. Box 7054, Uppsala SE-750 07, Sweden.
| | - Cecilia Ley
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, P.O. Box 7028, Uppsala SE-750 07, Sweden; Department of Pathology and Wildlife Diseases, National Veterinary Institute (SVA), Uppsala SE-751 89, Sweden
| | - Gunilla T Westermark
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, P.O. Box 571, Uppsala SE-751 23, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, P.O. Box 571, Uppsala SE-751 23, Sweden
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3
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Lu Y, Tian H, Peng H, Wang Q, Bunnell BA, Bazan NG, Hong S. Novel lipid mediator 7 S,14 R-docosahexaenoic acid: biogenesis and harnessing mesenchymal stem cells to ameliorate diabetic mellitus and retinal pericyte loss. Front Cell Dev Biol 2024; 12:1380059. [PMID: 38533089 PMCID: PMC10963555 DOI: 10.3389/fcell.2024.1380059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 02/29/2024] [Indexed: 03/28/2024] Open
Abstract
Introduction: Stem cells can be used to treat diabetic mellitus and complications. ω3-docosahexaenoic acid (DHA) derived lipid mediators are inflammation-resolving and protective. This study found novel DHA-derived 7S,14R-dihydroxy-4Z,8E,10Z,12E,16Z,19Z-docosahexaenoic acid (7S,14R-diHDHA), a maresin-1 stereoisomer biosynthesized by leukocytes and related enzymes. Moreover, 7S,14R-diHDHA can enhance mesenchymal stem cell (MSC) functions in the amelioration of diabetic mellitus and retinal pericyte loss in diabetic db/db mice. Methods: MSCs treated with 7S,14R-diHDHA were delivered into db/db mice i.v. every 5 days for 35 days. Results: Blood glucose levels in diabetic mice were lowered by 7S,14R-diHDHA-treated MSCs compared to control and untreated MSC groups, accompanied by improved glucose tolerance and higher blood insulin levels. 7S,14R-diHDHA-treated MSCs increased insulin+ β-cell ratio and decreased glucogan+ α-cell ratio in islets, as well as reduced macrophages in pancreas. 7S,14R-diHDHA induced MSC functions in promoting MIN6 β-cell viability and insulin secretion. 7S,14R-diHDHA induced MSC paracrine functions by increasing the generation of hepatocyte growth factor and vascular endothelial growth factor. Furthermore, 7S,14R-diHDHA enhanced MSC functions to ameliorate diabetes-caused pericyte loss in diabetic retinopathy by increasing their density in retina in db/db mice. Discussion: Our findings provide a novel strategy for improving therapy for diabetes and diabetic retinopathy using 7S,14R-diHDHA-primed MSCs.
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Affiliation(s)
- Yan Lu
- Neuroscience Center of Excellence, School of Medicine, L.S.U. Health, New Orleans, LA, United States
| | - Haibin Tian
- Neuroscience Center of Excellence, School of Medicine, L.S.U. Health, New Orleans, LA, United States
- Tongji University, Shanghai, China
| | - Hongying Peng
- Biostatistics, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH, United States
| | - Quansheng Wang
- Neuroscience Center of Excellence, School of Medicine, L.S.U. Health, New Orleans, LA, United States
- Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Bruce A. Bunnell
- Tulane University School of Medicine, Center for Stem Cell Research and Regenerative Medicine, New Orleans, LA, United States
| | - Nicolas G. Bazan
- Neuroscience Center of Excellence, School of Medicine, L.S.U. Health, New Orleans, LA, United States
- Department of Ophthalmology, School of Medicine, L.S.U. Health, New Orleans, LA, United States
| | - Song Hong
- Neuroscience Center of Excellence, School of Medicine, L.S.U. Health, New Orleans, LA, United States
- Department of Ophthalmology, School of Medicine, L.S.U. Health, New Orleans, LA, United States
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4
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Zhao Y, Jing W, Li L, Zhao S, Yamasaki M. Dynamical modeling the effect of glucagon-like peptide on glucose-insulin regulatory system based on mice experimental observation. Math Biosci 2023; 366:109090. [PMID: 37890522 DOI: 10.1016/j.mbs.2023.109090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023]
Abstract
As an emerging global epidemic, type 2 diabetes mellitus (T2DM) represents one of the leading causes of morbidity and mortality worldwide. Existing evidences demonstrated that glucagon-like peptide-1 (GLP-1) modulate the glucose regulatory system by enhancing the β-cell function. However, the detailed process of GLP-1 in glycaemic regulator for T2DM remains to be clarified. Thus, in this study, we propose an Institute of Cancer Research (ICR) mice high fat and cholesterol dietary experimental data-driven mathematical model to investigate the secretory effect of GLP-1 on the dynamics of glucose-insulin regulatory system. Specifically, we develop a mathematical model of GLP-1 dynamics as part of the interaction model of β-cell, insulin, and glucose dynamics. The parameter estimation and data fitting are in agreement with the data in mice experiments In addition, uncertainty quantification is performed to explore the possible factors that influence the pathways leading to the pathological state. Model analyses reveal that the high fat or high cholesterol diet stimulated GLP-1 plays an important role in the dynamics of glucose, insulin and β cells in short-term. These results show that enhanced GLP-1 may mitigate the dysregulation of glucose-insulin regulatory system via promoting the β cells function and stimulating secretion of insulin, which offers an in-depth insights into the mechanistic of hyperglycemia from dynamical approach and provide the theoretical basis for GLP-1 served as a potential clinical targeted drug for treatment of T2DM.
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Affiliation(s)
- Yu Zhao
- School of Public Health, Ningxia Medical University, Ningxia, Yinchuan 750004, China; Ningxia Key Laboratory of Environmental Factors and Chronic Disease Control, 1160 Shengli Street, Xingqing District, Yinchuan 750001, China.
| | - Wenjun Jing
- School of Statistics, Shanxi University of Finance and Economics, Taiyuan, Shanxi, 030006, China
| | - Liping Li
- School of Public Health, Ningxia Medical University, Ningxia, Yinchuan 750004, China; Ningxia Key Laboratory of Environmental Factors and Chronic Disease Control, 1160 Shengli Street, Xingqing District, Yinchuan 750001, China
| | - Shi Zhao
- JC School of Public Health and Primary Care, Chinese University of Hong Kong, Hong Kong, China
| | - Masayuki Yamasaki
- Faculty of Human Sciences, Shimane University, Shimane, 6908504, Japan.
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5
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Steinbüchel M, Menne J, Schröter R, Neugebauer U, Schlatter E, Ciarimboli G. Regulation of Transporters for Organic Cations by High Glucose. Int J Mol Sci 2023; 24:14051. [PMID: 37762353 PMCID: PMC10531077 DOI: 10.3390/ijms241814051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
Endogenous positively charged organic substances, including neurotransmitters and cationic uremic toxins, as well as exogenous organic cations such as the anti-diabetic medication metformin, serve as substrates for organic cation transporters (OCTs) and multidrug and toxin extrusion proteins (MATEs). These proteins facilitate their transport across cell membranes. Vectorial transport through the OCT/MATE axis mediates the hepatic and renal excretion of organic cations, regulating their systemic and local concentrations. Organic cation transporters are part of the remote sensing and signaling system, whose activity can be regulated to cope with changes in the composition of extra- and intracellular fluids. Glucose, as a source of energy, can also function as a crucial signaling molecule, regulating gene expression in various organs and tissues. Its concentration in the blood may fluctuate in specific physiological and pathophysiological conditions. In this work, the regulation of the activity of organic cation transporters was measured by incubating human embryonic kidney cells stably expressing human OCT1 (hOCT1), hOCT2, or hMATE1 with high glucose concentrations (16.7 mM). Incubation with this high glucose concentration for 48 h significantly stimulated the activity of hOCT1, hOCT2, and hMATE1 by increasing their maximal velocity (Vmax), but without significantly changing their affinity for the substrates. These effects were independent of changes in osmolarity, as the addition of equimolar concentrations of mannitol did not alter transporter activity. The stimulation of transporter activity was associated with a significant increase in transporter mRNA expression. Inhibition of the mechanistic target of rapamycin (mTOR) kinase with Torin-1 suppressed the transporter stimulation induced by incubation with 16.7 mM glucose. Focusing on hOCT2, it was shown that incubation with 16.7 mM glucose increased hOCT2 protein expression in the plasma membrane. Interestingly, an apparent trend towards higher hOCT2 mRNA expression was observed in kidneys from diabetic patients, a pathology characterized by high serum glucose levels. Due to the small number of samples from diabetic patients (three), this observation must be interpreted with caution. In conclusion, incubation for 48 h with a high glucose concentration of 16.7 mM stimulated the activity and expression of organic cation transporters compared to those measured in the presence of 5.6 mM glucose. This stimulation by a diabetic environment could increase cellular uptake of the anti-diabetic drug metformin and increase renal tubular secretion of organic cations in an early stage of diabetes.
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Affiliation(s)
| | | | | | | | | | - Giuliano Ciarimboli
- Experimental Nephrology, Department of Internal Medicine D, University Hospital Münster, 48149 Münster, Germany; (M.S.); (J.M.); (R.S.); (U.N.); (E.S.)
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6
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Nemati M, Ebrahimi Z, Karbalaei N, Dastghaib S, Khakshournia S, Sargazi M. In Vitro and In Vivo Improvement of Islet Quality and Transplantation Successes following Islet Treatment with Biomaterials in Diabetic Rats. J Diabetes Res 2023; 2023:1399917. [PMID: 37265573 PMCID: PMC10232112 DOI: 10.1155/2023/1399917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/08/2023] [Accepted: 05/07/2023] [Indexed: 06/03/2023] Open
Abstract
Background Loss of islet survival and function, caused by native niche disruption and oxidative stress induction during mechanical and enzymatic isolation, limits the effectiveness of islet transplantation. Reconstitution of islet microenvironment, vascularization, and decreased oxidative stress with biomaterials may improve islet quality and graft outcomes. We investigated effects of two biomaterials, platelet-rich plasma and pancreatic islets homogenate combination on islet recovery and quality by evaluating in vitro islet survival, secretory function, and oxidative stress parameters and assessing in vivo transplantation outcomes. Methods In vitro, islet viability and secretory function of isolated islets were assessed after 24 h and 72 h incubation with biomaterials. Also, oxidative stress markers were measured once after isolation and 24 h after incubation with biomaterials. For evaluating in vivo effects, cultured islets for 24 h were transplanted into subscapular space of diabetic rat kidney, and outcomes were analyzed by measuring serum glucose and insulin concentrations, glucose tolerance test, level of oxidative parameters, and pancreatic gene expression. Results Treating islets with biomaterials significantly increased their viability and secretory function, reduced MDA level, and elevate SOD and CAT activity. Decreased level of glucose and MDA improved insulin level, increased SOD activity, and also enhanced pdx1 and insulin gene expression in diabetic rats after islet transplantation. Conclusions Biomaterials used in the present study should be consider as beneficial materials for increasing islet transplantation outcome. These materials may hamper transplantation limitation to some extent.
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Affiliation(s)
- Marzieh Nemati
- Endocrinology and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Ebrahimi
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Narges Karbalaei
- Department of physiology, Shiraz University of Medical Sciences, Shiraz, Iran
- Histomorphometry and Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sanaz Dastghaib
- Endocrinology and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Authophagy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sara Khakshournia
- Department of Biochemistry, Shiraz University of Medical Science, Shiraz, Iran
| | - Mojtaba Sargazi
- Department of physiology, Shiraz University of Medical Sciences, Shiraz, Iran
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7
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Hermann FM, Kjærgaard MF, Tian C, Tiemann U, Jackson A, Olsen LR, Kraft M, Carlsson PO, Elfving IM, Kettunen JLT, Tuomi T, Novak I, Semb H. An insulin hypersecretion phenotype precedes pancreatic β cell failure in MODY3 patient-specific cells. Cell Stem Cell 2023; 30:38-51.e8. [PMID: 36563694 DOI: 10.1016/j.stem.2022.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 10/04/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
MODY3 is a monogenic hereditary form of diabetes caused by mutations in the transcription factor HNF1A. The patients progressively develop hyperglycemia due to perturbed insulin secretion, but the pathogenesis is unknown. Using patient-specific hiPSCs, we recapitulate the insulin secretion sensitivity to the membrane depolarizing agent sulfonylurea commonly observed in MODY3 patients. Unexpectedly, MODY3 patient-specific HNF1A+/R272C β cells hypersecrete insulin both in vitro and in vivo after transplantation into mice. Consistently, we identified a trend of increased birth weight in human HNF1A mutation carriers compared with healthy siblings. Reduced expression of potassium channels, specifically the KATP channel, in MODY3 β cells, increased calcium signaling, and rescue of the insulin hypersecretion phenotype by pharmacological targeting ATP-sensitive potassium channels or low-voltage-activated calcium channels suggest that more efficient membrane depolarization underlies the hypersecretion of insulin in MODY3 β cells. Our findings identify a pathogenic mechanism leading to β cell failure in MODY3.
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Affiliation(s)
- Florian M Hermann
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark
| | - Maya Friis Kjærgaard
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark
| | - Chenglei Tian
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark; Institute of Translational Stem Cell Research, Helmholtz Diabetes Center, Helmholtz Zentrum München, München, Germany
| | - Ulf Tiemann
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark
| | - Abigail Jackson
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark
| | - Lars Rønn Olsen
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Maria Kraft
- Lund Stem Cell Center, Lund University, Lund, Sweden
| | - Per-Ola Carlsson
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden; Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | | | - Jarno L T Kettunen
- Folkhalsan Research Center, Helsinki, Finland; Institute for Molecular Medicine Finland, University of Finland, Helsinki, Finland; Department of Endocrinology, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| | - Tiinamaija Tuomi
- Folkhalsan Research Center, Helsinki, Finland; Institute for Molecular Medicine Finland, University of Finland, Helsinki, Finland; Department of Endocrinology, Abdominal Center, Helsinki University Hospital, Helsinki, Finland
| | - Ivana Novak
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Semb
- Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, Copenhagen, Denmark; Institute of Translational Stem Cell Research, Helmholtz Diabetes Center, Helmholtz Zentrum München, München, Germany.
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8
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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: 3] [Impact Index Per Article: 1.5] [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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9
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Li Y, Deng X, Zhuang W, Li Y, Xue H, Lv X, Zhu S. Tanshinone IIA down-regulates -transforming growth factor beta 1 to relieve renal tubular epithelial cell inflammation and pyroptosis caused by high glucose. Bioengineered 2022; 13:12224-12236. [PMID: 35577353 PMCID: PMC9275952 DOI: 10.1080/21655979.2022.2074619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Diabetic nephropathy (DN) is a microvascular disease caused by diabetes. Tanshinone IIA has been indicated to ameliorate streptozotocin-induced DN. This study explores the effect of tanshinone IIA on high glucose-induced renal tubular epithelial cell pyroptosis and inflammation. High glucose-stimulated HK-2 cells were used as the in-vitro model of DN and were treated with tanshinone IIA at concentrations of 1, 5, 10 μM for 24 h with the same doses of tolbutamide as the control. After tanshinone IIA treatment, HK-2 cells were transfected with pcDNA-transforming growth factor beta 1 (TGFB1) or sh-TGFB1 for 48 h. RT-qPCR was used to detect the mRNA levels of TNF-α, IL-6, IL-1β, and IL-18. Cell apoptosis and pyroptosis were detected by flow cytometry and cell immunofluorescence. Bioinformatics screening predicted that tanshinone IIA might be an effective component of Salvia miltiorrhiza Bunge (Labiatae) for the treatment of DN. Tanshinone IIA exerted a protective effect in the in-vitro model of DN by suppressing inflammation and pyroptosis via the TGFB1-dependent pathway. Tanshinone IIA inhibited high glucose-induced renal tubular epithelial cell inflammation and cell death through pyroptosis by regulating TGFB1, indicating the therapeutic potential of tanshinone IIA for DN treatment.
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Affiliation(s)
- Ying Li
- Department of Endocrinology, The Affiliated Suqian First People's Hospital of Nanjing Medical University, Suqian, China
| | - Xu Deng
- Department of Endocrinology, The Affiliated Suqian First People's Hospital of Nanjing Medical University, Suqian, China
| | - Wenlong Zhuang
- Department of General Surgery, The Affiliated Suqian First People's Hospital of Nanjing Medical University, Suqian, China
| | - Yong Li
- Department of General Surgery, The Affiliated Suqian First People's Hospital of Nanjing Medical University, Suqian, China
| | - Hui Xue
- Department of Endocrinology, The Affiliated Suqian First People's Hospital of Nanjing Medical University, Suqian, China
| | - Xin Lv
- Department of Endocrinology, The Affiliated Suqian First People's Hospital of Nanjing Medical University, Suqian, China
| | - Shuqin Zhu
- Department of Endocrinology, The Affiliated Suqian First People's Hospital of Nanjing Medical University, Suqian, China
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10
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Rohli KE, Boyer CK, Blom SE, Stephens SB. Nutrient Regulation of Pancreatic Islet β-Cell Secretory Capacity and Insulin Production. Biomolecules 2022; 12:335. [PMID: 35204835 PMCID: PMC8869698 DOI: 10.3390/biom12020335] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 01/27/2023] Open
Abstract
Pancreatic islet β-cells exhibit tremendous plasticity for secretory adaptations that coordinate insulin production and release with nutritional demands. This essential feature of the β-cell can allow for compensatory changes that increase secretory output to overcome insulin resistance early in Type 2 diabetes (T2D). Nutrient-stimulated increases in proinsulin biosynthesis may initiate this β-cell adaptive compensation; however, the molecular regulators of secretory expansion that accommodate the increased biosynthetic burden of packaging and producing additional insulin granules, such as enhanced ER and Golgi functions, remain poorly defined. As these adaptive mechanisms fail and T2D progresses, the β-cell succumbs to metabolic defects resulting in alterations to glucose metabolism and a decline in nutrient-regulated secretory functions, including impaired proinsulin processing and a deficit in mature insulin-containing secretory granules. In this review, we will discuss how the adaptative plasticity of the pancreatic islet β-cell's secretory program allows insulin production to be carefully matched with nutrient availability and peripheral cues for insulin signaling. Furthermore, we will highlight potential defects in the secretory pathway that limit or delay insulin granule biosynthesis, which may contribute to the decline in β-cell function during the pathogenesis of T2D.
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Affiliation(s)
- Kristen E. Rohli
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, USA; (K.E.R.); (C.K.B.); (S.E.B.)
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Cierra K. Boyer
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, USA; (K.E.R.); (C.K.B.); (S.E.B.)
- Department of Neuroscience and Pharmacology, University of Iowa, Iowa City, IA 52242, USA
| | - Sandra E. Blom
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, USA; (K.E.R.); (C.K.B.); (S.E.B.)
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Samuel B. Stephens
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA 52242, USA; (K.E.R.); (C.K.B.); (S.E.B.)
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA
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11
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Sarnobat D, Moffett RC, Flatt PR, Tarasov AI. Effects of first-line diabetes therapy with biguanides, sulphonylurea and thiazolidinediones on the differentiation, proliferation and apoptosis of islet cell populations. J Endocrinol Invest 2022; 45:95-103. [PMID: 34191257 PMCID: PMC8741670 DOI: 10.1007/s40618-021-01620-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 06/17/2021] [Indexed: 12/13/2022]
Abstract
AIMS Metformin, rosiglitazone and sulfonylureas enhance either insulin action or secretion and thus have been used extensively as early stage anti-diabetic medication, independently of the aetiology of the disease. When administered to newly diagnosed diabetes patients, these drugs produce variable results. Here, we examined the effects of the three early stage oral hypoglycaemic agents in mice with diabetes induced by multiple low doses of streptozotocin, focusing specifically on the developmental biology of pancreatic islets. METHODS Streptozotocin-treated diabetic mice expressing a fluorescent reporter specifically in pancreatic islet α-cells were administered the biguanide metformin (100 mg/kg), thiazolidinedione rosiglitazone (10 mg/kg), or sulfonylurea tolbutamide (20 mg/kg) for 10 days. We assessed the impact of the treatment on metabolic status of the animals as well as on the morphology, proliferative potential and transdifferentiation of pancreatic islet cells, using immunofluorescence. RESULTS The effect of the therapy on the islet cells varied depending on the drug and included enhanced pancreatic islet β-cell proliferation, in case of metformin and rosiglitazone; de-differentiation of α-cells and β-cell apoptosis with tolbutamide; increased relative number of β-cells and bi-hormonal insulin + glucagon + cells with metformin. These effects were accompanied by normalisation of food and fluid intake with only minor effects on glycaemia at the low doses of the agents employed. CONCLUSIONS Our data suggest that metformin and rosiglitazone attenuate the depletion of the β-cell pool in the streptozotocin-induced diabetes, whereas tolbutamide exacerbates the β-cell apoptosis, but is likely to protect β-cells from chronic hyperglycaemia by directly elevating insulin secretion.
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Affiliation(s)
- D Sarnobat
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - R C Moffett
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - P R Flatt
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK
| | - A I Tarasov
- School of Biomedical Sciences, Ulster University, Cromore Road, Coleraine, BT52 1SA, Northern Ireland, UK.
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12
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Stožer A, Paradiž Leitgeb E, Pohorec V, Dolenšek J, Križančić Bombek L, Gosak M, Skelin Klemen M. The Role of cAMP in Beta Cell Stimulus-Secretion and Intercellular Coupling. Cells 2021; 10:1658. [PMID: 34359828 PMCID: PMC8304079 DOI: 10.3390/cells10071658] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/18/2021] [Accepted: 06/28/2021] [Indexed: 12/22/2022] Open
Abstract
Pancreatic beta cells secrete insulin in response to stimulation with glucose and other nutrients, and impaired insulin secretion plays a central role in development of diabetes mellitus. Pharmacological management of diabetes includes various antidiabetic drugs, including incretins. The incretin hormones, glucagon-like peptide-1 and gastric inhibitory polypeptide, potentiate glucose-stimulated insulin secretion by binding to G protein-coupled receptors, resulting in stimulation of adenylate cyclase and production of the secondary messenger cAMP, which exerts its intracellular effects through activation of protein kinase A or the guanine nucleotide exchange protein 2A. The molecular mechanisms behind these two downstream signaling arms are still not fully elucidated and involve many steps in the stimulus-secretion coupling cascade, ranging from the proximal regulation of ion channel activity to the central Ca2+ signal and the most distal exocytosis. In addition to modifying intracellular coupling, the effect of cAMP on insulin secretion could also be at least partly explained by the impact on intercellular coupling. In this review, we systematically describe the possible roles of cAMP at these intra- and inter-cellular signaling nodes, keeping in mind the relevance for the whole organism and translation to humans.
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Affiliation(s)
- Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Eva Paradiž Leitgeb
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Viljem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia
| | - Lidija Križančić Bombek
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
- Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; (A.S.); (E.P.L.); (V.P.); (J.D.); (L.K.B.); (M.G.)
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13
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Association of serum vitamin D status with development of type 2 diabetes: A retrospective cross-sectional study. CLINICAL NUTRITION OPEN SCIENCE 2021. [DOI: 10.1016/j.nutos.2020.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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14
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Szymczak-Pajor I, Fleszar K, Kasznicki J, Gralewska P, Śliwińska A. A potential role of calpains in sulfonylureas (SUs) -mediated death of human pancreatic cancer cells (1.2B4). Toxicol In Vitro 2021; 73:105128. [PMID: 33652124 DOI: 10.1016/j.tiv.2021.105128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/01/2021] [Accepted: 02/25/2021] [Indexed: 12/25/2022]
Abstract
Sulfonylureas (SUs) are suggested to accelerate the pancreatic β-cells mass loss via apoptosis. However, little is known whether calpains mediate this process. The aim of the present study is to evaluate the involvement of calpains in SUs-induced death of human pancreatic cancer (PC) cell line 1.2B4. The cells were exposed to: glibenclamide, glimepiride and gliclazide for 72 h. The expression analysis of caspase-3 (CASP-3), TP53, calpain 1 (CAPN-1), calpain 2 (CAPN-2) and calpain 10 (CAPN-10) was detected using RT-PCR method. Intracellular Ca2+ concentrations, CASP-3 activity and total calpain activity were also evaluated. Our results have shown that glibenclamide and glimepiride decrease 1.2B4 cells viability with accompanied increase in intracellular Ca2+ concentration and increased expression of apoptosis-related CASP-3 and TP53. Gliclazide did not affect 1.2B4 cell viability and Ca2+ concentration, however, it downregulated CASP-3 and upregulated TP53. Interestingly, 50 μM glimepiride increased expression of CAPN-1, CAPN-2 and CAPN-10 whereas 50 μM glibenclamide solely upregulated CAPN-2 expression. We have shown that 10 μM and 50 μM glibenclamide and glimepiride increased the activity of CASP-3, but decreased total calpain activity. Our results suggest that calpains may be involved in glibenclamide- and glimepiride-induced death of PC cells. However, further investigation is required to confirm the engagement of calpains in SUs-mediated death of PC cells, especially studies on protein level of particular isoforms of calpains should be conducted.
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Affiliation(s)
- Izabela Szymczak-Pajor
- Department of Nucleic Acid Biochemistry, Medical University of Lodz, 251 Pomorska, 92-213 Lodz, Poland.
| | - Krzysztof Fleszar
- Student Scientific Society of Civilization Diseases, Medical University of Lodz, 251 Pomorska, 92-213 Lodz, Poland.
| | - Jacek Kasznicki
- Department of Internal Diseases, Diabetology and Clinical Pharmacology, Medical University of Lodz, 251 Pomorska, 92-213 Lodz, Poland.
| | - Patrycja Gralewska
- Department of Medical Biophysics, Institute of Biophysics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland.
| | - Agnieszka Śliwińska
- Department of Nucleic Acid Biochemistry, Medical University of Lodz, 251 Pomorska, 92-213 Lodz, Poland.
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15
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A Practical Guide to Rodent Islet Isolation and Assessment Revisited. Biol Proced Online 2021; 23:7. [PMID: 33641671 PMCID: PMC7919091 DOI: 10.1186/s12575-021-00143-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 01/26/2021] [Indexed: 02/06/2023] Open
Abstract
Insufficient insulin secretion is a key component of both type 1 and type 2 diabetes. Since insulin is released by the islets of Langerhans, obtaining viable and functional islets is critical for research and transplantation. The effective and efficient isolation of these small islands of endocrine cells from the sea of exocrine tissue that is the rest of the pancreas is not necessarily simple or quick. Choosing and administering the digestive enzyme, separation of the islets from acinar tissue, and culture of islets are all things that must be considered. The purpose of this review is to provide a history of the development of islet isolation procedures and to serve as a practical guide to rodent islet research for newcomers to islet biology. We discuss key elements of mouse islet isolation including choosing collagenase, the digestion process, purification of islets using a density gradient, and islet culture conditions. In addition, this paper reviews techniques for assessing islet viability and function such as visual assessment, glucose-stimulated insulin secretion and intracellular calcium measurements. A detailed protocol is provided that describes a common method our laboratory uses to obtain viable and functional mouse islets for in vitro study. This review thus provides a strong foundation for successful procurement and purification of high-quality mouse islets for research purposes.
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16
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Emerging Roles of Metallothioneins in Beta Cell Pathophysiology: Beyond and Above Metal Homeostasis and Antioxidant Response. BIOLOGY 2021; 10:biology10030176. [PMID: 33652748 PMCID: PMC7996892 DOI: 10.3390/biology10030176] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 02/17/2021] [Accepted: 02/22/2021] [Indexed: 12/15/2022]
Abstract
Simple Summary Defective insulin secretion by pancreatic beta cells is key for the development of type 2 diabetes but the precise mechanisms involved are poorly understood. Metallothioneins are metal binding proteins whose precise biological roles have not been fully characterized. Available evidence indicated that Metallothioneins are protective cellular effectors involved in heavy metal detoxification, metal ion homeostasis and antioxidant defense. This concept has however been challenged by emerging evidence in different medical research fields revealing novel negative roles of Metallothioneins, including in the context of diabetes. In this review, we gather and analyze the available knowledge regarding the complex roles of Metallothioneins in pancreatic beta cell biology and insulin secretion. We comprehensively analyze the evidence showing positive effects of Metallothioneins on beta cell function and survival as well as the emerging evidence revealing negative effects and discuss the possible underlying mechanisms. We expose in parallel findings from other medical research fields and underscore unsettled questions. Then, we propose some future research directions to improve knowledge in the field. Abstract Metallothioneins (MTs) are low molecular weight, cysteine-rich, metal-binding proteins whose precise biological roles have not been fully characterized. Existing evidence implicated MTs in heavy metal detoxification, metal ion homeostasis and antioxidant defense. MTs were thus categorized as protective effectors that contribute to cellular homeostasis and survival. This view has, however, been challenged by emerging evidence in different medical fields revealing novel pathophysiological roles of MTs, including inflammatory bowel disease, neurodegenerative disorders, carcinogenesis and diabetes. In the present focused review, we discuss the evidence for the role of MTs in pancreatic beta-cell biology and insulin secretion. We highlight the pattern of specific isoforms of MT gene expression in rodents and human beta-cells. We then discuss the mechanisms involved in the regulation of MTs in islets under physiological and pathological conditions, particularly type 2 diabetes, and analyze the evidence revealing adaptive and negative roles of MTs in beta-cells and the potential mechanisms involved. Finally, we underscore the unsettled questions in the field and propose some future research directions.
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17
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Postnatal maturation of calcium signaling in islets of Langerhans from neonatal mice. Cell Calcium 2020; 94:102339. [PMID: 33422769 DOI: 10.1016/j.ceca.2020.102339] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Revised: 12/20/2020] [Accepted: 12/21/2020] [Indexed: 01/02/2023]
Abstract
Pancreatic islet cells develop mature physiological responses to glucose and other fuels postnatally. In this study, we used fluorescence imaging techniques to measure changes in intracellular calcium ([Ca2+]i) to compare islets isolated from mice on postnatal days 0, 4, and 12 with islets from adult CD-1 mice. In addition, we used publicly available RNA-sequencing data to compare expression levels of key genes in β-cell physiology with [Ca2+]i data across these ages. We show that islets isolated from mice on postnatal day 0 displayed elevated [Ca2+]i in basal glucose (≤4 mM) but lower [Ca2+]i responses to stimulation by 12-20 mM glucose compared to adult. Neonatal islets displayed more adult-like [Ca2+]i in basal glucose by day 4 but continued to show lower [Ca2+]i responses to 16 and 20 mM glucose stimulation up to at least day 12. A right shift in glucose sensing (EC50) correlated with lower fragment-per-kilobase-of-transcript-per-million-reads-mapped (FPKM) of Slc2a2 (glut2) and Actn3 and increased FPKM for Galk1 and Nupr1. Differences in [Ca2+]i responses to additional stimuli were also observed. Calcium levels in the endoplasmic reticulum were elevated on day 0 but became adult-like by day 4, which corresponded with reduced expression in Atp2a2 (SERCA2) and novel K+-channel Ktd17, increased expression of Pml, Wfs1, Thada, and Herpud1, and basal [Ca2+]i maturing to adult levels. Ion-channel activity also matured rapidly, but RNA sequencing data mining did not yield strong leads. In conclusion, the maturation of islet [Ca2+]i signaling is complex and multifaceted; several possible gene targets were identified that may participate in this process.
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18
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Abulizi A, Cardone RL, Stark R, Lewandowski SL, Zhao X, Hillion J, Ma L, Sehgal R, Alves TC, Thomas C, Kung C, Wang B, Siebel S, Andrews ZB, Mason GF, Rinehart J, Merrins MJ, Kibbey RG. Multi-Tissue Acceleration of the Mitochondrial Phosphoenolpyruvate Cycle Improves Whole-Body Metabolic Health. Cell Metab 2020; 32:751-766.e11. [PMID: 33147485 PMCID: PMC7679013 DOI: 10.1016/j.cmet.2020.10.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 06/30/2020] [Accepted: 10/09/2020] [Indexed: 12/25/2022]
Abstract
The mitochondrial GTP (mtGTP)-dependent phosphoenolpyruvate (PEP) cycle couples mitochondrial PEPCK (PCK2) to pyruvate kinase (PK) in the liver and pancreatic islets to regulate glucose homeostasis. Here, small molecule PK activators accelerated the PEP cycle to improve islet function, as well as metabolic homeostasis, in preclinical rodent models of diabetes. In contrast, treatment with a PK activator did not improve insulin secretion in pck2-/- mice. Unlike other clinical secretagogues, PK activation enhanced insulin secretion but also had higher insulin content and markers of differentiation. In addition to improving insulin secretion, acute PK activation short-circuited gluconeogenesis to reduce endogenous glucose production while accelerating red blood cell glucose turnover. Four-week delivery of a PK activator in vivo remodeled PK phosphorylation, reduced liver fat, and improved hepatic and peripheral insulin sensitivity in HFD-fed rats. These data provide a preclinical rationale for PK activation to accelerate the PEP cycle to improve metabolic homeostasis and insulin sensitivity.
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Affiliation(s)
| | - Rebecca L Cardone
- Department of Internal Medicine, Yale University, New Haven, CT 06520, USA
| | - Romana Stark
- Department of Physiology, Monash University, Melbourne, VIC 3800, Australia
| | - Sophie L Lewandowski
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, and Department of Biomolecular Chemistry, University of Wisconsin-Madison, and William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Xiaojian Zhao
- Department of Internal Medicine, Yale University, New Haven, CT 06520, USA
| | - Joelle Hillion
- Department of Internal Medicine, Yale University, New Haven, CT 06520, USA
| | - Lingjun Ma
- Department of Internal Medicine, Yale University, New Haven, CT 06520, USA
| | - Raghav Sehgal
- Department of Internal Medicine, Yale University, New Haven, CT 06520, USA
| | - Tiago C Alves
- Department of Internal Medicine, Yale University, New Haven, CT 06520, USA
| | - Craig Thomas
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, and Lymphoid Malignancies Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Bei Wang
- Department of Internal Medicine, Yale University, New Haven, CT 06520, USA
| | - Stephan Siebel
- Department of Internal Medicine, Yale University, New Haven, CT 06520, USA
| | - Zane B Andrews
- Department of Physiology, Monash University, Melbourne, VIC 3800, Australia
| | - Graeme F Mason
- Department of Diagnostic Radiology and Psychiatry, Yale University, New Haven, CT 06520, USA
| | - Jesse Rinehart
- Department of Cellular & Molecular Physiology, Yale University, New Haven, CT 06520, USA
| | - Matthew J Merrins
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, and Department of Biomolecular Chemistry, University of Wisconsin-Madison, and William S. Middleton Memorial Veterans Hospital, Madison, WI, USA
| | - Richard G Kibbey
- Department of Internal Medicine, Yale University, New Haven, CT 06520, USA; Department of Cellular & Molecular Physiology, Yale University, New Haven, CT 06520, USA.
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19
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Morsi M, Schulze T, Früh E, Brüning D, Panten U, Rustenbeck I. Fresh and cultured mouse islets differ in their response to nutrient stimulation. Endocr Connect 2020; 9:769-782. [PMID: 32688335 PMCID: PMC7424343 DOI: 10.1530/ec-20-0289] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 07/19/2020] [Indexed: 12/25/2022]
Abstract
Observing different kinetics of nutrient-induced insulin secretion in fresh and cultured islets under the same condition we compared parameters of stimulus secretion coupling in freshly isolated and 22-h-cultured NMRI mouse islets. Stimulation of fresh islets with 30 mM glucose after perifusion without nutrient gave a continuously ascending secretion rate. In 22-h-cultured islets the same protocol produced a brisk first phase followed by a moderately elevated plateau, a pattern regarded to be typical for mouse islets. This was also the response of cultured islets to the nutrient secretagogue alpha-ketoisocaproic acid, whereas the secretion of fresh islets increased similarly fast but remained strongly elevated. The responses of fresh and cultured islets to purely depolarizing stimuli (tolbutamide or KCl), however, were closely similar. Signs of apoptosis and necrosis were rare in both preparations. In cultured islets, the glucose-induced rise of the cytosolic Ca2+ concentration started from a lower value and was larger as was the increase of the ATP/ADP ratio. The prestimulatory level of mitochondrial reducing equivalents, expressed as the NAD(P)H/FAD fluorescence ratio, was lower in cultured islets, but increased more strongly than in fresh islets. When culture conditions were modified by replacing RPMI with Krebs-Ringer medium and FCS with BSA, the amount of released insulin varied widely, but the kinetics always showed a predominant first phase. In conclusion, the secretion kinetics of fresh mouse islets is more responsive to variations of nutrient stimulation than cultured islets. The more uniform kinetics of the latter may be caused by a different use of endogenous metabolites.
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Affiliation(s)
- Mai Morsi
- Institute of Pharmacology, Toxicology and Clinical Pharmacy, Technische Universität Braunschweig, Braunschweig, Germany
| | - Torben Schulze
- Institute of Pharmacology, Toxicology and Clinical Pharmacy, Technische Universität Braunschweig, Braunschweig, Germany
| | - Eike Früh
- Institute of Pharmacology, Toxicology and Clinical Pharmacy, Technische Universität Braunschweig, Braunschweig, Germany
| | - Dennis Brüning
- Institute of Pharmacology, Toxicology and Clinical Pharmacy, Technische Universität Braunschweig, Braunschweig, Germany
| | - Uwe Panten
- Institute of Pharmacology, Toxicology and Clinical Pharmacy, Technische Universität Braunschweig, Braunschweig, Germany
| | - Ingo Rustenbeck
- Institute of Pharmacology, Toxicology and Clinical Pharmacy, Technische Universität Braunschweig, Braunschweig, Germany
- Correspondence should be addressed to I Rustenbeck:
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20
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In Silico Analysis of New Potent Anti-hyperglycemic Molecule for Diabetes Type 2 Management. Int J Pept Res Ther 2020. [DOI: 10.1007/s10989-019-09905-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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21
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Loganadan NK, Huri HZ, Vethakkan SR, Hussein Z. Clinical and genetic predictors of secondary sulfonylurea failure in Type 2 diabetes patients: the SUCLINGEN study. Pharmacogenomics 2020; 21:587-600. [PMID: 32468916 DOI: 10.2217/pgs-2019-0171] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Background: Due to several limitations in the study designs of sulfonylurea pharmacogenomics studies, we investigated the clinical and genetic predictors of secondary sulfonylurea failure in Type 2 diabetes patients. Materials & methods: Patients receiving the maximum sulfonylurea and metformin doses for >1 year were enrolled. Secondary sulfonylurea failure was defined as HbA1c >7.0% (>53 mmol/mol) after a 12-month follow-up. Results: By multivariate analysis, increased insulin resistance (HOMA2-IR), baseline HbA1c >7.0%, residing in eastern Peninsular Malaysia, and the CC genotype of rs757110 ABCC8 gene polymorphism were independent predictors of secondary sulfonylurea failure (p < 0.05) while sulfonylurea-induced hypoglycemia was protective against such failure (p < 0.05). Conclusion: Sulfonylurea does not benefit patients with an increased risk of secondary sulfonylurea failure.
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Affiliation(s)
| | - Hasniza Zaman Huri
- Faculty of Pharmacy, University of Malaya, Kuala Lumpur, 50603, Malaysia.,Clinical Investigation Centre, 5th Floor, East Tower, University of Malaya Medical Centre, Lembah Pantai, Kuala Lumpur, 59100, Malaysia
| | - Shireene Ratna Vethakkan
- Division of Endocrinology, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, 50603, Malaysia
| | - Zanariah Hussein
- Department of Medicine, Putrajaya Hospital, Precinct 7, Putrajaya, 62250, Malaysia
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22
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Li WH. Functional analysis of islet cells in vitro, in situ, and in vivo. Semin Cell Dev Biol 2020; 103:14-19. [PMID: 32081627 DOI: 10.1016/j.semcdb.2020.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/05/2020] [Indexed: 12/20/2022]
Abstract
The islet of Langerhans contains at least five types of endocrine cells producing distinct hormones. In response to nutrient or neuronal stimulation, islet endocrine cells release biochemicals including peptide hormones to regulate metabolism and to control glucose homeostasis. It is now recognized that malfunction of islet cells, notably insufficient insulin release of β-cells and hypersecretion of glucagon from α-cells, represents a causal event leading to hyperglycemia and frank diabetes, a disease that is increasing at an alarming rate to reach an epidemic level worldwide. Understanding the mechanisms regulating stimulus-secretion coupling and investigating how islet β-cells maintain a robust secretory activity are important topics in islet biology and diabetes research. To facilitate such studies, a number of biological systems and assay platforms have been developed for the functional analysis of islet cells. These technologies have enabled detailed analyses of individual islets at the cellular level, either in vitro, in situ, or in vivo.
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Affiliation(s)
- Wen-Hong Li
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX, 75390-9039, United States.
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Whitticar NB, Nunemaker CS. Reducing Glucokinase Activity to Enhance Insulin Secretion: A Counterintuitive Theory to Preserve Cellular Function and Glucose Homeostasis. Front Endocrinol (Lausanne) 2020; 11:378. [PMID: 32582035 PMCID: PMC7296051 DOI: 10.3389/fendo.2020.00378] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 05/12/2020] [Indexed: 12/21/2022] Open
Abstract
Pancreatic beta-cells are the only cells in the body that can synthesize and secrete insulin. Through the process of glucose-stimulated insulin secretion, beta-cells release insulin into circulation, stimulating GLUT4-dependent glucose uptake into peripheral tissue. Insulin is normally secreted in pulses that promote signaling at the liver. Long before type 2 diabetes is diagnosed, beta-cells become oversensitive to glucose, causing impaired pulsatility and overstimulation in fasting levels of glucose. The resulting hypersecretion of insulin can cause poor insulin signaling and clearance at the liver, leading to hyperinsulinemia and insulin resistance. Continued overactivity can eventually lead to beta-cell exhaustion and failure at which point type 2 diabetes begins. To prevent or reverse the negative effects of overstimulation, beta-cell activity can be reduced. Clinical studies have revealed the potential of beta-cell rest to reverse new cases of diabetes, but treatments lack durable benefits. In this perspective, we propose an intervention that reduces overactive glucokinase activity in the beta-cell. Glucokinase is known as the glucose sensor of the beta-cell due to its high control over insulin secretion. Therefore, glycolytic overactivity may be responsible for hyperinsulinemia early in the disease and can be reduced to restore normal stimulus-secretion coupling. We have previously reported that reducing glucokinase activity in prediabetic mouse islets can restore pulsatility and enhance insulin secretion. Building on this counterintuitive finding, we review the importance of pulsatile insulin secretion and highlight how normalizing glucose sensing in the beta cell during prediabetic hyperinsulinemia may restore pulsatility and improve glucose homeostasis.
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Affiliation(s)
- Nicholas B. Whitticar
- Translational Biomedical Sciences Program, Graduate College, Ohio University, Athens, OH, United States
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens OH, United States
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States
| | - Craig S. Nunemaker
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens OH, United States
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States
- *Correspondence: Craig S. Nunemaker
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From Hyper- to Hypoinsulinemia and Diabetes: Effect of KCNH6 on Insulin Secretion. Cell Rep 2019; 25:3800-3810.e6. [PMID: 30590050 DOI: 10.1016/j.celrep.2018.12.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 06/26/2018] [Accepted: 11/30/2018] [Indexed: 01/03/2023] Open
Abstract
Glucose-stimulated insulin secretion from islet β cells is mediated by KATP channels. However, the role of non-KATP K+ channels in insulin secretion is largely unknown. Here, we show that a non-KATP K+ channel, KCNH6, plays a key role in insulin secretion and glucose hemostasis in humans and mice. KCNH6 p.P235L heterozygous mutation co-separated with diabetes in a four-generation pedigree. Kcnh6 knockout (KO) or Kcnh6 p.P235L knockin (KI) mice had a phenotype characterized by changing from hypoglycemia with hyperinsulinemia to hyperglycemia with insulin deficiency. Islets from the young KO mice had increased intracellular calcium concentration and increased insulin secretion. However, islets from the adult KO mice not only had increased intracellular calcium levels but also had remarkable ER stress and apoptosis, associated with loss of β cell mass and decreased insulin secretion. Therefore, dysfunction of KCNH6 causes overstimulation of insulin secretion in the short term and β cell failure in the long term.
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FMK, an Inhibitor of p90RSK, Inhibits High Glucose-Induced TXNIP Expression via Regulation of ChREBP in Pancreatic β Cells. Int J Mol Sci 2019; 20:ijms20184424. [PMID: 31505737 PMCID: PMC6770409 DOI: 10.3390/ijms20184424] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/06/2019] [Accepted: 09/06/2019] [Indexed: 12/24/2022] Open
Abstract
Hyperglycemia is the major characteristic of diabetes mellitus, and a chronically high glucose (HG) level causes β-cell glucolipotoxicity, which is characterized by lipid accumulation, impaired β-cell function, and apoptosis. TXNIP (Thioredoxin-interacting protein) is a key mediator of diabetic β-cell apoptosis and dysfunction in diabetes, and thus, its regulation represents a therapeutic target. Recent studies have reported that p90RSK is implicated in the pathogenesis of diabetic cardiomyopathy and nephropathy. In this study, we used FMK (a p90RSK inhibitor) to determine whether inhibition of p90RSK protects β-cells from chronic HG-induced TXNIP expression and to investigate the molecular mechanisms underlying the effect of FMK on its expression. In INS-1 pancreatic β-cells, HG-induced β-cell dysfunction, apoptosis, and ROS generation were significantly diminished by FMK. In contrast BI-D1870 (another p90RSK inhibitor) did not attenuate HG-induced TXNIP promoter activity or TXNIP expression. In addition, HG-induced nuclear translocation of ChREBP and its transcriptional target molecules were found to be regulated by FMK. These results demonstrate that HG-induced pancreatic β-cell dysfunction resulting in HG conditions is associated with TXNIP expression, and that FMK is responsible for HG-stimulated TXNIP gene expression by inactivating the regulation of ChREBP in pancreatic β-cells. Taken together, these findings suggest FMK may protect against HG-induced β-cell dysfunction and TXNIP expression by ChREBP regulation in pancreatic β-cells, and that FMK is a potential therapeutic reagent for the drug development of diabetes and its complications.
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Lawal SK, Adeniji AA, Sulaiman SO, Akajewole MM, Buhari MO, Osinubi AA. Comparative effects of glibenclamide, metformin and insulin on fetal pancreatic histology and maternal blood glucose in pregnant streptozotocin-induced diabetic rats. Afr Health Sci 2019; 19:2491-2504. [PMID: 32127822 PMCID: PMC7040257 DOI: 10.4314/ahs.v19i3.25] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Oral hypoglycemic agents use during pregnancy was assumed to cause fetal macrosomia and skeletal deformities, and maternal complications due to significant transfer across placenta or ineffective control of blood glucose. OBJECTIVE This study investigated effects of insulin, metformin and glibenclamide on maternal blood glucose; and fetal crown-rump length, gross malformation and pancreatic histology in pregnant streptozotocin-induced diabetic rats. METHODS Twenty-five pregnant rats of groups 1 to 5 as normal and diabetic controls; and diabetic treated with insulin, metformin and glibenclamide were used. Experimental GDM was induced using 45 and 35mg/Kgbw of intraperitoneal streptozotocin. RESULTS Metformin, Insulin and Glibenclamide significantly reduced maternal glucose by 140.6mg/dL, 103.2mg/dL and 98.54mg/dl; respectively and showed islets with regular interlobular ducts, islets with some irregular interlobular ducts, and islets with many irregular interlobular ducts in histological fetal pancreatic photomicrographs respectively. This depicts metformin having highest ameliorative effect. There were no significant differences in maternal and fetal body weights, maternal blood glucose between diabetic groups, and fetal gross examination. CONCLUSION At the doses used in this research, metformin and glibenclamide showed no adverse effects on maternal and fetal features in the treatment of GDM. Thus, they can be used as safe and inexpensive alternatives to insulin.
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Affiliation(s)
- Sodiq Kolawole Lawal
- Department of Anatomy, St. Francis University College of Health Sciences and Allied Sciences, Ifakara, Tanzania
- Discipline of Clinical Anatomy, Nelson Mandela School of Medicine, University of KwaZulu-Natal, 4001, Durban, South Africa
| | - Adeoluwa Akeem Adeniji
- Department of Anatomy, College of Medicine, University of Lagos, Idi-Araba, Lagos, Nigeria
| | - Sheu Oluwadare Sulaiman
- Department of Physiology, Kampala International University Western campus, Ishaka-Bushenyi, Uganda
| | - Mustapha Mas'ud Akajewole
- Department of Human Anatomy, School of Health and Medical Sciences, State University of Zanzibar, Zanzibar, Tanzania
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27
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Wang X, Gao YT, Jiang D, Wang Y, Du H, Lv J, Li SJ. Hv1-deficiency protects β cells from glucotoxicity through regulation of NOX4 level. Biochem Biophys Res Commun 2019; 513:434-438. [PMID: 30967259 DOI: 10.1016/j.bbrc.2019.03.195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 03/29/2019] [Indexed: 11/27/2022]
Abstract
High glucose (HG)-induced oxidative stress contributes to the dysfunction of pancreatic β cells in diabetes. The voltage-gated proton channel Hv1 has been proposed to support reactive oxygen species (ROS) production during respiratory bursts. However, the effect of Hv1 on glucotoxicity in pancreatic β cells is not clear yet. In this study, we examined the protective effects of Hv1-deficiency in HG cultured β cells. Following 48 h of treatment with 30 mM high glucose, Hv1 KO β cells showed higher cell viability, lower cell apoptosis and a more stable insulin gene expression level compared to WT β cells. In both control and HG cultured β cells, deficiency of Hv1 decreased the glucose- and PMA-induced ROS production. Finally, HG incubation led to NOX4 upregulation in WT β cells, which could be inhibited by HV1 deficiency. In conclusion, Hv1-deficiency prevents the HG treatment-induced NOX4 upregulation and protects β cells from glucotoxicity.
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Affiliation(s)
- Xudong Wang
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China
| | - Ying-Tang Gao
- Key Laboratory of Artificial Cell, Third Central Clinical College of Tianjin Medical University, Tianjin, 300170, PR China
| | - Dan Jiang
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China
| | - Yuzhou Wang
- Laboratory Animal Center, College of Life Sciences, Nankai University, Tianjin, 300071, PR China
| | - Hongyan Du
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China
| | - Jili Lv
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China
| | - Shu Jie Li
- Department of Biophysics, School of Physics Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, 300071, PR China.
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Shyr ZA, Wang Z, York NW, Nichols CG, Remedi MS. The role of membrane excitability in pancreatic β-cell glucotoxicity. Sci Rep 2019; 9:6952. [PMID: 31061431 PMCID: PMC6502887 DOI: 10.1038/s41598-019-43452-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 01/11/2019] [Indexed: 01/09/2023] Open
Abstract
Persistent hyperglycemia is causally associated with pancreatic β-cell dysfunction and loss of pancreatic insulin. Glucose normally enhances β-cell excitability through inhibition of KATP channels, opening of voltage-dependent calcium channels, increased [Ca2+]i, which triggers insulin secretion. Glucose-dependent excitability is lost in islets from KATP-knockout (KATP-KO) mice, in which β-cells are permanently hyperexcited, [Ca2+]i, is chronically elevated and insulin is constantly secreted. Mouse models of human neonatal diabetes in which KATP gain-of-function mutations are expressed in β-cells (KATP-GOF) also lose the link between glucose metabolism and excitation-induced insulin secretion, but in this case KATP-GOF β-cells are chronically underexcited, with permanently low [Ca2+]i and lack of glucose-dependent insulin secretion. We used KATP-GOF and KATP-KO islets to examine the role of altered-excitability in glucotoxicity. Wild-type islets showed rapid loss of insulin content when chronically incubated in high-glucose, an effect that was reversed by subsequently switching to low glucose media. In contrast, hyperexcitable KATP-KO islets lost insulin content in both low- and high-glucose, while underexcitable KATP-GOF islets maintained insulin content in both conditions. Loss of insulin content in chronic excitability was replicated by pharmacological inhibition of KATP by glibenclamide, The effects of hyperexcitable and underexcitable islets on glucotoxicity observed in in vivo animal models are directly opposite to the effects observed in vitro: we clearly demonstrate here that in vitro, hyperexcitability is detrimental to islets whereas underexcitability is protective.
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Affiliation(s)
- Zeenat A Shyr
- Department of Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri, 63110, USA
| | - Zhiyu Wang
- Department of Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri, 63110, USA.,Endocrine Consultants Northwest, Franciscan Medical Group, 1628 South Mildred St. Suite 104, Tacoma, WA, 98465, USA
| | - Nathaniel W York
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri, 63110, USA
| | - Colin G Nichols
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri, 63110, USA.,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri, 63110, USA
| | - Maria S Remedi
- Department of Medicine, Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri, 63110, USA. .,Department of Cell Biology and Physiology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri, 63110, USA. .,Center for the Investigation of Membrane Excitability Diseases, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, Missouri, 63110, USA.
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29
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Szymczak-Pajor I, Śliwińska A. Analysis of Association between Vitamin D Deficiency and Insulin Resistance. Nutrients 2019; 11:E794. [PMID: 30959886 PMCID: PMC6520736 DOI: 10.3390/nu11040794] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/31/2019] [Accepted: 04/01/2019] [Indexed: 02/06/2023] Open
Abstract
Recent evidence revealed extra skeleton activity of vitamin D, including prevention from cardiometabolic diseases and cancer development as well as anti-inflammatory properties. It is worth noting that vitamin D deficiency is very common and may be associated with the pathogenesis of insulin-resistance-related diseases, including obesity and diabetes. This review aims to provide molecular mechanisms showing how vitamin D deficiency may be involved in the insulin resistance formation. The PUBMED database and published reference lists were searched to find studies published between 1980 and 2019. It was identified that molecular action of vitamin D is involved in maintaining the normal resting levels of ROS and Ca2+, not only in pancreatic β-cells, but also in insulin responsive tissues. Both genomic and non-genomic action of vitamin D is directed towards insulin signaling. Thereby, vitamin D reduces the extent of pathologies associated with insulin resistance such as oxidative stress and inflammation. More recently, it was also shown that vitamin D prevents epigenetic alterations associated with insulin resistance and diabetes. In conclusion, vitamin D deficiency is one of the factors accelerating insulin resistance formation. The results of basic and clinical research support beneficial action of vitamin D in the reduction of insulin resistance and related pathologies.
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Affiliation(s)
- Izabela Szymczak-Pajor
- Department of Nucleic Acid Biochemistry, Medical University of Lodz, 251 Pomorska, 92-213 Lodz, Poland.
| | - Agnieszka Śliwińska
- Department of Nucleic Acid Biochemistry, Medical University of Lodz, 251 Pomorska, 92-213 Lodz, Poland.
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30
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Rachdaoui N, Polo-Parada L, Ismail-Beigi F. Prolonged Exposure to Insulin Inactivates Akt and Erk 1/2 and Increases Pancreatic Islet and INS1E β-Cell Apoptosis. J Endocr Soc 2018; 3:69-90. [PMID: 30697602 PMCID: PMC6344346 DOI: 10.1210/js.2018-00140] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 10/29/2018] [Indexed: 12/18/2022] Open
Abstract
Chronic hyperinsulinemia, in vivo, increases the resistance of peripheral tissues to insulin by desensitizing insulin signaling. Insulin, in a heterologous manner, can also cause IGF-1 resistance. The aim of the current study was to investigate whether insulin-mediated insulin and IGF-1 resistance develops in pancreatic β-cells and whether this resistance results in β-cell decompensation. Chronic exposure of rat islets or INS1E β-cells to increasing concentrations of insulin decreased AktS473 phosphorylation in response to subsequent acute stimulation with 10 nM insulin or IGF-1. Prolonged exposure to high insulin levels not only inhibited AktS473 phosphorylation, but it also resulted in a significant inhibition of the phosphorylation of P70S6 kinase and Erk1/2 phosphorylation in response to the acute stimulation by glucose, insulin, or IGF-1. Decreased activation of Akt, P70S6K, and Erk1/2 was associated with decreased insulin receptor substrate 2 tyrosine phosphorylation and insulin receptor β-subunit abundance; neither IGF receptor β-subunit content nor its phosphorylation were affected. These signaling impairments were associated with decreased SERCA2 expression, perturbed plasma membrane calcium current and intracellular calcium handling, increased endoplasmic reticulum stress markers such as eIF2αS51 phosphorylation and Bip (GRP78) expression, and increased islet and β-cell apoptosis. We demonstrate that prolonged exposure to high insulin levels induces not only insulin resistance, but in a heterologous manner causes resistance to IGF-1 in rat islets and insulinoma cells resulting in decreased cell survival. These findings suggest the possibility that chronic exposure to hyperinsulinemia may negatively affect β-cell mass by increasing β-cell apoptosis.
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Affiliation(s)
- Nadia Rachdaoui
- Division of Clinical and Molecular Endocrinology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Luis Polo-Parada
- Department of Medical Pharmacology and Physiology, Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, Missouri
| | - Faramarz Ismail-Beigi
- Division of Clinical and Molecular Endocrinology, Department of Medicine, Case Western Reserve University, Cleveland, Ohio
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31
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Zhang R, Zhou X, Shen X, Xie T, Xu C, Zou Z, Dong J, Liao L. Different sulfonylureas induce the apoptosis of proximal tubular epithelial cell differently via closing K ATP channel. Mol Med 2018; 24:47. [PMID: 30180807 PMCID: PMC6122448 DOI: 10.1186/s10020-018-0042-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/16/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Sulfonylureas (SUs) are widely prescribed for the treatment of type 2 diabetes (T2DM). Sulfonylurea receptors (SURs) are their main functional receptors. These receptors are also found in kidney, especially the tubular cells. However, the effects of SUs on renal proximal tubular epithelial cells (PTECs) were unclear. METHODS Three commonly used SUs were included in this study to investigate if different SUs have different effects on the apoptosis of PTECs. HK-2 cells were exposed to SUs for 24 h prior to exposure to 30 mM glucose, the apoptosis rate was evaluated by Annexin/PI flow cytometry. Bcl-2, Bax and the ratio of LC3II to LC3I were also studied by western blot in vitro. Diazoxide was used to evaluate the role of KATP channel in SUs-induced apoptosis of PTECs. A Student's t-test was used to assess significance for data within two groups. RESULTS Treatment with glibenclamide aggravated the apoptosis of HK-2 cells in high-glucose, as indicated by a significant decrease in the expression of Bcl-2 and increase in Bax. Additionally, the decreased LC3II/LC3I reflects that the autophagy was inhibited by glibenclamide. Similar but less pronounced change was found in glimepiride group, however, nearly opposite effects were found in gliclazide group. Further, the effects of glibenclamide on apoptosis promotion and the decreased LC3II/LC3I were ameliorated obviously by treatment with 100uM diazoxide. The potential protection effect of gliclazide was also inhibited after opening the KATP channel. CONCLUSION Our results suggest that, the effects of glibenclamide and glimepiride on PTECs apoptosis, especially the former, were achieved in part by closing the KATP channel. In contrast to glibenclamide and glimepiride, therapeutic concentrations of gliclazide showed an inhibitory effect on apoptosis of PTECs, which may have a benefit in the preservation of functional PTECs mass.
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Affiliation(s)
- Rui Zhang
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong, China
| | - Xiaojun Zhou
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong, China
| | - Xue Shen
- Division of Endocrinology, Department of Internal Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Tianyue Xie
- Division of Endocrinology, Department of Internal Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
| | - Chunmei Xu
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong, China
| | - Zhiwei Zou
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Jianjun Dong
- Department of Endocrinology, Qilu Hospital of Shandong University, Jinan, Shandong, China.
- Department of Internal Medicine, Division of Endocrinology, Qilu Hospital of Shandong University, No. 107, Wenhuaxi Road, Jinan, Shandong, China.
| | - Lin Liao
- Department of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong, China.
- Department of Internal Medicine, Division of Endocrinology, Shandong Provincial Qianfoshan Hospital, Shandong University, No. 16766, Jingshi Road, Jinan, Shandong, China.
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Jeon JY, Lee SJ, Lee S, Kim SJ, Han SJ, Kim HJ, Kim DJ, Kim YS, Woo JT, Ahn KJ, Nam M, Baik SH, Park Y, Lee K. Failure of monotherapy in clinical practice in patients with type 2 diabetes: The Korean National Diabetes Program. J Diabetes Investig 2018; 9:1144-1152. [PMID: 29328551 PMCID: PMC6123024 DOI: 10.1111/jdi.12801] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 12/29/2017] [Accepted: 01/07/2018] [Indexed: 01/20/2023] Open
Abstract
AIMS/INTRODUCTION We investigated the failure of monotherapy in patients with type 2 diabetes mellitus in real practice settings. MATERIALS AND METHODS The Korean National Diabetes Program was a prospective, multicenter observational cohort study of type 2 diabetes mellitus patients in Korea. Of the 3,950 patients enrolled in the study, we studied 998 who were continuously maintained on monotherapy for at least 90 days at six participating centers. To balance the baseline characteristics of patients in each group, we used propensity matching at a 1:1 ratio (metformin vs sulfonylureas) and 4:1 ratio (metformin vs meglitinides and metformin vs alpha-glucosidase inhibitors [aGIs]). The hazard ratios (HRs) of treatments (compared with metformin) were determined by Cox's proportional hazards regression modeling. RESULTS The median follow-up time was 56 months, and monotherapy failed in 45% of all patients. The annual incidences of failure were 15.6%, 21.3%, 27% and 9.6% in the metformin, sulfonylurea, meglitinide and aGI groups. Compared with metformin, sulfonylureas and meglitinides were associated with higher risks of monotherapy failure (HR 1.39, 95% confidence interval [CI] 1.08-1.80; HR 1.92, 95% CI 1.13-3.27), and aGIs with risks similar to that of metformin (HR 0.80, 95% CI 0.44-1.45). When analyzed by failure type, sulfonylureas, meglitinides and aGIs were associated with a higher risk of a switch to other agents (HR 4.43, 95% CI 2.14-9.17; HR 18.80, 95% CI 6.21-56.93; HR 4.25, 95% CI 1.49-12.13), and aGIs with a lower risk of prescription of add-on second agents (HR 0.16, 95% CI 0.04-0.64). CONCLUSIONS Metformin was associated with a lower failure risk than were sulfonylureas and meglitinides, but a comparable aGI failure rate.
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Affiliation(s)
- Ja Young Jeon
- Department of Endocrinology and MetabolismAjou University School of MedicineSuwonKorea
| | - Soo Jin Lee
- Department of Medicare AdministrationBackseok Arts UniversitySeoulKorea
| | - Sieun Lee
- Office of BiostatisticsAjou University School of MedicineSuwonKorea
| | - Soo Jin Kim
- Office of BiostatisticsAjou University School of MedicineSuwonKorea
| | - Seung Jin Han
- Department of Endocrinology and MetabolismAjou University School of MedicineSuwonKorea
| | - Hae Jin Kim
- Department of Endocrinology and MetabolismAjou University School of MedicineSuwonKorea
| | - Dae Jung Kim
- Department of Endocrinology and MetabolismAjou University School of MedicineSuwonKorea
| | - Young Seol Kim
- Department of Internal MedicineKyung Hee University College of MedicineSeoulKorea
| | - Jeong Taek Woo
- Department of Internal MedicineKyung Hee University College of MedicineSeoulKorea
| | - Kyu Jeung Ahn
- Department of Internal MedicineKyung Hee University College of MedicineSeoulKorea
| | - Moonsuk Nam
- Department of Internal MedicineInha University College of MedicineIncheonKorea
| | - Sei Hyun Baik
- Department of Internal MedicineKorea University College of MedicineSeoulKorea
| | - Yongsoo Park
- Department of Molecular and Integrative PhysiologyUniversity of Illinois at Urbana‐ChampaignUrbanaIllinoisUSA
| | - Kwan‐Woo Lee
- Department of Endocrinology and MetabolismAjou University School of MedicineSuwonKorea
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Quinault A, Leloup C, Denwood G, Spiegelhalter C, Rodriguez M, Lefebvre P, Messaddeq N, Zhang Q, Dacquet C, Pénicaud L, Collins SC. Modulation of large dense core vesicle insulin content mediates rhythmic hormone release from pancreatic beta cells over the 24h cycle. PLoS One 2018; 13:e0193882. [PMID: 29543849 PMCID: PMC5854349 DOI: 10.1371/journal.pone.0193882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 02/20/2018] [Indexed: 11/19/2022] Open
Abstract
The rhythmic nature of insulin secretion over the 24h cycle in pancreatic islets has been mostly investigated using transcriptomics studies showing that modulation of insulin secretion over this cycle is achieved via distal stages of insulin secretion. We set out to measure β-cell exocytosis using in depth cell physiology techniques at several time points. In agreement with the activity and feeding pattern of nocturnal rodents, we find that C57/Bl6J islets in culture for 24h exhibit higher insulin secretion during the corresponding dark phase than in the light phase (Zeitgeber Time ZT20 and ZT8, respectively, in vivo). Glucose-induced insulin secretion is increased by 21% despite normal intracellular Ca2+ transients and depolarization-evoked exocytosis, as measured by whole-cell capacitance measurements. This paradox is explained by a 1.37-fold increase in beta cell insulin content. Ultramorphological analyses show that vesicle size and density are unaltered, demonstrating that intravesicular insulin content per granule is modulated over the 24h cycle. Proinsulin levels did not change between ZT8 and ZT20. Islet glucagon content was inversely proportional to insulin content indicating that this unique feature is likely to support a physiological role. Microarray data identified the differential expression of 301 transcripts, of which 26 are miRNAs and 54 are known genes (including C2cd4b, a gene previously involved in insulin processing, and clock genes such as Bmal1 and Rev-erbα). Mouse β-cell secretion over the full course of the 24h cycle may rely on several distinct cellular functions but late night increase in insulin secretion depends solely on granule insulin content.
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Affiliation(s)
- Aurore Quinault
- CSGA, AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université de Bourgogne Franche-Comté, 9E Boulevard Jeanne d'Arc, Dijon, France
| | - Corinne Leloup
- CSGA, AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université de Bourgogne Franche-Comté, 9E Boulevard Jeanne d'Arc, Dijon, France
| | - Geoffrey Denwood
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, Oxford, United Kingdom
| | | | - Marianne Rodriguez
- Metabolism Discovery Research Pole of Therapeutical innovation Institut de Recherche Servier, 11 rue des Moulineaux Suresnes, France
| | - Philippe Lefebvre
- European Genomic Institute for Diabetes and UMR 1011 Inserm Université Nord de France-Institut Pasteur de Lille, Boulevard du Professeur Leclerc, Lille, France
| | | | - Quan Zhang
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, University of Oxford, Headington, Oxford, United Kingdom
| | - Catherine Dacquet
- Biotechnology and Biomarker Research, Institut de Recherche Servier, 125 Chemin de Ronde, Croissy sur Seine, France
| | - Luc Pénicaud
- CSGA, AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université de Bourgogne Franche-Comté, 9E Boulevard Jeanne d'Arc, Dijon, France
| | - Stephan C. Collins
- CSGA, AgroSup Dijon, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Université de Bourgogne Franche-Comté, 9E Boulevard Jeanne d'Arc, Dijon, France
- IGBMC, 1 Rue Laurent Fries, Illkirch-Graffenstaden, France
- * E-mail:
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Bensellam M, Jonas JC, Laybutt DR. Mechanisms of β-cell dedifferentiation in diabetes: recent findings and future research directions. J Endocrinol 2018; 236:R109-R143. [PMID: 29203573 DOI: 10.1530/joe-17-0516] [Citation(s) in RCA: 149] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 12/04/2017] [Indexed: 12/13/2022]
Abstract
Like all the cells of an organism, pancreatic β-cells originate from embryonic stem cells through a complex cellular process termed differentiation. Differentiation involves the coordinated and tightly controlled activation/repression of specific effectors and gene clusters in a time-dependent fashion thereby giving rise to particular morphological and functional cellular features. Interestingly, cellular differentiation is not a unidirectional process. Indeed, growing evidence suggests that under certain conditions, mature β-cells can lose, to various degrees, their differentiated phenotype and cellular identity and regress to a less differentiated or a precursor-like state. This concept is termed dedifferentiation and has been proposed, besides cell death, as a contributing factor to the loss of functional β-cell mass in diabetes. β-cell dedifferentiation involves: (1) the downregulation of β-cell-enriched genes, including key transcription factors, insulin, glucose metabolism genes, protein processing and secretory pathway genes; (2) the concomitant upregulation of genes suppressed or expressed at very low levels in normal β-cells, the β-cell forbidden genes; and (3) the likely upregulation of progenitor cell genes. These alterations lead to phenotypic reconfiguration of β-cells and ultimately defective insulin secretion. While the major role of glucotoxicity in β-cell dedifferentiation is well established, the precise mechanisms involved are still under investigation. This review highlights the identified molecular mechanisms implicated in β-cell dedifferentiation including oxidative stress, endoplasmic reticulum (ER) stress, inflammation and hypoxia. It discusses the role of Foxo1, Myc and inhibitor of differentiation proteins and underscores the emerging role of non-coding RNAs. Finally, it proposes a novel hypothesis of β-cell dedifferentiation as a potential adaptive mechanism to escape cell death under stress conditions.
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Affiliation(s)
- Mohammed Bensellam
- Garvan Institute of Medical ResearchSydney, New South Wales, Australia
- Université Catholique de LouvainInstitut de Recherche Expérimentale et Clinique, Pôle d'Endocrinologie, Diabète et Nutrition, Brussels, Belgium
| | - Jean-Christophe Jonas
- Université Catholique de LouvainInstitut de Recherche Expérimentale et Clinique, Pôle d'Endocrinologie, Diabète et Nutrition, Brussels, Belgium
| | - D Ross Laybutt
- Garvan Institute of Medical ResearchSydney, New South Wales, Australia
- St Vincent's Clinical SchoolUNSW Sydney, Sydney, New South Wales, Australia
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Karin O, Alon U. Biphasic response as a mechanism against mutant takeover in tissue homeostasis circuits. Mol Syst Biol 2017; 13:933. [PMID: 28652282 PMCID: PMC5488663 DOI: 10.15252/msb.20177599] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Tissues use feedback circuits in which cells send signals to each other to control their growth and survival. We show that such feedback circuits are inherently unstable to mutants that misread the signal level: Mutants have a growth advantage to take over the tissue, and cannot be eliminated by known cell-intrinsic mechanisms. To resolve this, we propose that tissues have biphasic responses in and the signal is toxic at both high and low levels, such as glucotoxicity of beta cells, excitotoxicity in neurons, and toxicity of growth factors to T cells. This gives most of these mutants a frequency-dependent selective disadvantage, which leads to their elimination. However, the biphasic mechanisms create a new unstable fixed point in the feedback circuit beyond which runaway processes can occur, leading to risk of diseases such as diabetes and neurodegenerative disease. Hence, glucotoxicity, which is a dangerous cause of diabetes, may have a protective anti-mutant effect. Biphasic responses in tissues may provide an evolutionary stable strategy that avoids invasion by commonly occurring mutants, but at the same time cause vulnerability to disease.
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Affiliation(s)
- Omer Karin
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Uri Alon
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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Molecular mechanisms of ROS production and oxidative stress in diabetes. Biochem J 2017; 473:4527-4550. [PMID: 27941030 DOI: 10.1042/bcj20160503c] [Citation(s) in RCA: 518] [Impact Index Per Article: 74.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 10/07/2016] [Accepted: 10/10/2016] [Indexed: 12/18/2022]
Abstract
Oxidative stress and chronic inflammation are known to be associated with the development of metabolic diseases, including diabetes. Oxidative stress, an imbalance between oxidative and antioxidative systems of cells and tissues, is a result of over production of oxidative-free radicals and associated reactive oxygen species (ROS). One outcome of excessive levels of ROS is the modification of the structure and function of cellular proteins and lipids, leading to cellular dysfunction including impaired energy metabolism, altered cell signalling and cell cycle control, impaired cell transport mechanisms and overall dysfunctional biological activity, immune activation and inflammation. Nutritional stress, such as that caused by excess high-fat and/or carbohydrate diets, promotes oxidative stress as evident by increased lipid peroxidation products, protein carbonylation and decreased antioxidant status. In obesity, chronic oxidative stress and associated inflammation are the underlying factors that lead to the development of pathologies such as insulin resistance, dysregulated pathways of metabolism, diabetes and cardiovascular disease through impaired signalling and metabolism resulting in dysfunction to insulin secretion, insulin action and immune responses. However, exercise may counter excessive levels of oxidative stress and thus improve metabolic and inflammatory outcomes. In the present article, we review the cellular and molecular origins and significance of ROS production, the molecular targets and responses describing how oxidative stress affects cell function including mechanisms of insulin secretion and action, from the point of view of possible application of novel diabetic therapies based on redox regulation.
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Yildirim V, Bertram R. Calcium Oscillation Frequency-Sensitive Gene Regulation and Homeostatic Compensation in Pancreatic β-Cells. Bull Math Biol 2017; 79:1295-1324. [PMID: 28497293 DOI: 10.1007/s11538-017-0286-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/27/2017] [Indexed: 02/03/2023]
Abstract
Pancreatic islet [Formula: see text]-cells are electrically excitable cells that secrete insulin in an oscillatory fashion when the blood glucose concentration is at a stimulatory level. Insulin oscillations are the result of cytosolic [Formula: see text] oscillations that accompany bursting electrical activity of [Formula: see text]-cells and are physiologically important. ATP-sensitive [Formula: see text] channels (K(ATP) channels) play the key role in setting the overall activity of the cell and in driving bursting, by coupling cell metabolism to the membrane potential. In humans, when there is a defect in K(ATP) channel function, [Formula: see text]-cells fail to respond appropriately to changes in the blood glucose level, and electrical and [Formula: see text] oscillations are lost. However, mice compensate for K(ATP) channel defects in islet [Formula: see text]-cells by employing alternative mechanisms to maintain electrical and [Formula: see text] oscillations. In a recent study, we showed that in mice islets in which K(ATP) channels are genetically knocked out another [Formula: see text] current, provided by inward-rectifying [Formula: see text] channels, is increased. With mathematical modeling, we demonstrated that a sufficient upregulation in these channels can account for the paradoxical electrical bursting and [Formula: see text] oscillations observed in these [Formula: see text]-cells. However, the question of determining the correct level of upregulation that is necessary for this compensation remained unanswered, and this question motivates the current study. [Formula: see text] is a well-known regulator of gene expression, and several examples have been shown of genes that are sensitive to the frequency of the [Formula: see text] signal. In this mathematical modeling study, we demonstrate that a [Formula: see text] oscillation frequency-sensitive gene transcription network can adjust the gene expression level of a compensating [Formula: see text] channel so as to rescue electrical bursting and [Formula: see text] oscillations in a model [Formula: see text]-cell in which the key K(ATP) current is removed. This is done without the prescription of a target [Formula: see text] level, but evolves naturally as a consequence of the feedback between the [Formula: see text]-dependent enzymes and the cell's electrical activity. More generally, the study indicates how [Formula: see text] can provide the link between gene expression and cellular electrical activity that promotes wild-type behavior in a cell following gene knockout.
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Affiliation(s)
- Vehpi Yildirim
- Department of Mathematics, Florida State University, Tallahassee, FL, 32306, USA
| | - Richard Bertram
- Department of Mathematics and Programs in Molecular Biophysics and Neuroscience, Florida State University, Tallahassee, FL, 32306, USA.
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Vitamin D deficiency and diabetes. Biochem J 2017; 474:1321-1332. [DOI: 10.1042/bcj20170042] [Citation(s) in RCA: 133] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 02/10/2017] [Accepted: 02/13/2017] [Indexed: 02/06/2023]
Abstract
Vitamin D deficiency has been linked to the onset of diabetes. This review summarizes the role of Vitamin D in maintaining the normal release of insulin by the pancreatic beta cells (β-cells). Diabetes is initiated by the onset of insulin resistance. The β-cells can overcome this resistance by releasing more insulin, thus preventing hyperglycaemia. However, as this hyperactivity increases, the β-cells experience excessive Ca2+ and reactive oxygen species (ROS) signalling that results in cell death and the onset of diabetes. Vitamin D deficiency contributes to both the initial insulin resistance and the subsequent onset of diabetes caused by β-cell death. Vitamin D acts to reduce inflammation, which is a major process in inducing insulin resistance. Vitamin D maintains the normal resting levels of both Ca2+ and ROS that are elevated in the β-cells during diabetes. Vitamin D also has a very significant role in maintaining the epigenome. Epigenetic alterations are a feature of diabetes by which many diabetes-related genes are inactivated by hypermethylation. Vitamin D acts to prevent such hypermethylation by increasing the expression of the DNA demethylases that prevent hypermethylation of multiple gene promoter regions of many diabetes-related genes. What is remarkable is just how many cellular processes are maintained by Vitamin D. When Vitamin D is deficient, many of these processes begin to decline and this sets the stage for the onset of diseases such as diabetes.
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Abstract
Biological systems can maintain constant steady-state output despite variation in biochemical parameters, a property known as exact adaptation. Exact adaptation is achieved using integral feedback, an engineering strategy that ensures that the output of a system robustly tracks its desired value. However, it is unclear how physiological circuits also keep their output dynamics precise-including the amplitude and response time to a changing input. Such robustness is crucial for endocrine and neuronal homeostatic circuits because they need to provide a precise dynamic response in the face of wide variation in the physiological parameters of their target tissues; how such circuits compensate their dynamics for unavoidable natural fluctuations in parameters is unknown. Here, we present a design principle that provides the desired robustness, which we call dynamical compensation (DC). We present a class of circuits that show DC by means of a nonlinear feedback loop in which the regulated variable controls the functional mass of the controlling endocrine or neuronal tissue. This mechanism applies to the control of blood glucose by insulin and explains several experimental observations on insulin resistance. We provide evidence that this mechanism may also explain compensation and organ size control in other physiological circuits.
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Affiliation(s)
- Omer Karin
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
| | - Avital Swisa
- Department of Developmental Biology and Cancer Research and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Benjamin Glaser
- Endocrinology and Metabolism Service, Department of Internal Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research and Molecular Biology, The Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Uri Alon
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot, Israel
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Cell-penetrating peptides induce apoptosis and necrosis through specific mechanism and cause impairment of Na +-K +-ATPase and mitochondria. Amino Acids 2016; 49:75-88. [PMID: 27645217 DOI: 10.1007/s00726-016-2327-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 09/03/2016] [Indexed: 12/15/2022]
Abstract
Cell-penetrating peptides (CPPs) are widely used in the development of various drug delivery systems because of their ability of penetrating plasma membrane. However, the safety of their application remains largely unknown. In this study, we found that the incubation of two main kinds of CPPs with human normal liver cells could cause the occurrence of apoptosis and necrosis, then the detailed apoptosis-related protein were detected out. To discover the specific way which leads to these results, several methods were used in this study. Several cytokines, such as Caspase3 and Bcl-2, were detected to prove that the damage happened after treated with different CPPs. Then shielding the positive charge of TAT and R8, depletion of Na+ in culturing medium and addition of several inhibitors of specific ATPase site were used to investigate whether the cytotoxicity were charge-dependent and ATPase-related. Furthermore, the membrane potential of mitochondria and the leakage of mitochondrial cytochrome c were detected after treated with CPPs to investigate the damage on mitochondria. In general, our results assess the cytotoxicity caused by two main kinds of CPPs and reveal the clear mechanism of how it occurs. This study reveals the essence of cytotoxicity caused by CPPs, and the methods we followed can be used to evaluate the biocompatibility of new-designed CPPs, which makes the application of CPPs better and safer.
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Rorsman P. Review: Insulin secretion: function and therapy of pancreatic beta-cells in diabetes. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/14746514050050040201] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
nsulin is secreted from the beta-cells of the pancreatic islets in response to an elevation of blood glucose concentration. This review describes a current view of the metabolic control of insulin secretion and the molecular mechanisms involved, including the role played by the beta-cell to ensure correct release of insulin as a result of electrical signals. It then considers what goes wrong in type 2 diabetes, a disease resulting from insufficient insulin secretion. It focuses on the influence of genetics exploring the theory of a genetic predisposition to type 2 diabetes, as well as the roles played by age and obesity. Finally, the mode of action of the hypoglycaemic sulphonylureas is discussed and the potential implications for the beta-cell associated with a sulphonylurea-based therapy.
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Affiliation(s)
- Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology; and Metabolism, Churchill Hospital, University of Oxford, Oxford, OX3 7LJ, UK,
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Alshatwi AA, Subash-Babu P. Aloe-Emodin Protects RIN-5F (Pancreatic β-cell) Cell from Glucotoxicity via Regulation of Pro-Inflammatory Cytokine and Downregulation of Bax and Caspase 3. Biomol Ther (Seoul) 2016; 24:49-56. [PMID: 26759701 PMCID: PMC4703352 DOI: 10.4062/biomolther.2015.056] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 08/14/2015] [Accepted: 09/15/2015] [Indexed: 12/15/2022] Open
Abstract
To determine the protective effect of aloe-emodin (AE) from high glucose induced toxicity in RIN-5F (pancreatic β-cell) cell and restoration of its function was analyzed. RIN-5F cells have been cultured in high glucose (25 mM glucose) condition, with and without AE treatment. RIN-5F cells cultured in high glucose decreased cell viability and increased ROS levels after 48 hr compared with standard medium (5.5 mM glucose). Glucotoxicity was confirmed by significantly increased ROS production, increased pro-inflammatory (IFN-γ, IL-1β,) & decreased anti-inflammatory (IL-6&IL-10) cytokine levels, increased DNA fragmentation. In addition, we found increased Bax, caspase 3, Fadd, and Fas and significantly reduced Bcl-2 expression after 48 hr. RIN-5F treated with both high glucose and AE (20 μM) decreased ROS generation and prevent RIN-5F cell from glucotoxicity. In addition, AE treated cells cultured in high glucose were transferred to standard medium, normal responsiveness to glucose was restored within 8hr and normal basal insulin release within 24 hr was achieved when compared to high glucose.
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Affiliation(s)
- Ali A Alshatwi
- Adipogenesis and Immunobiology Research Lab, Department of Food Sciences and Nutrition, College of Food Sciences and Agriculture, King Saud University, Riyadh 11451, Kingdom of Saudi Arabia
| | - P Subash-Babu
- Adipogenesis and Immunobiology Research Lab, Department of Food Sciences and Nutrition, College of Food Sciences and Agriculture, King Saud University, Riyadh 11451, Kingdom of Saudi Arabia
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Chen YH, Du L, Geng XY, Peng YL, Shen JN, Zhang YG, Liu GJ, Sun X. Effects of sulfonylureas on lipids in type 2 diabetes mellitus: a meta-analysis of randomized controlled trials. J Evid Based Med 2015; 8:134-48. [PMID: 26066789 DOI: 10.1111/jebm.12157] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 05/27/2015] [Indexed: 02/05/2023]
Abstract
OBJECTIVE Previous studies suggested that dyslipidemia was potentially associated with anti-diabetic medications of sulfonylureas (SUs). The results were, however, inconsistent. Therefore, we conducted a meta-analysis of randomized controlled trials (RCTs) to assess the effects of SUs on the level of lipids in patients with type 2 diabetes mellitus (T2DM). METHODS We searched PubMed, EMBASE, and CENTRAL databases for RCTs that addressed the effects of second- and/or third-generation SUs used in T2DM patients on lipids profiles with study duration of at least 12 weeks. Two reviewers independently screened literature, collected data, and assessed methodological quality of included studies. The meta-analysis was performed by using the RevMan5.1 software. RESULTS A total of 59 RCTs were included, of which 52 were included for final meta-analysis. The results suggested that SUs statistically increased the levels of FFA (SMD = 0.24, 95%CI 0.06 to 0.42) and TG (MD = 0.06, 95%CI 0.02 to 0.10), but decreased HDL-C (MD = -0.07, 95%CI -0.11 to -0.04) and LDL-C (MD = -0.11, 95%CI -0.17 to -0.04); but the SUs had no effect on TC (MD = 0.01, 95%CI -0.05 to 0.08), ApoA1 (MD = 0.01, 95%CI -0.03 to 0.04), and Apo B (MD = -0.01, 95%CI -0.05 to 0.03). When compared to metformin, SUs could increase TC and LDL-C; compared to glinides, SUs increased TC and lowered HDL-C; compared to thiazolidinediones, SUs reduced TC, LDL-C, HDL-C, and increase TG. CONCLUSIONS SUs have a small effect on lipids, although they may statistically increase the level of FFA and TG, and decrease LDL-C and HDL-C.
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Affiliation(s)
- Yue-hong Chen
- Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, Chengdu, China
| | - Liang Du
- Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, Chengdu, China
| | - Xing-yuan Geng
- Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, Chengdu, China
| | - Yuan-ling Peng
- Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jia-ni Shen
- Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, Chengdu, China
| | - Yong-gang Zhang
- Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, Chengdu, China
| | - Guan-jian Liu
- Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, Chengdu, China
| | - Xin Sun
- Chinese Evidence-based Medicine Center, West China Hospital, Sichuan University, Chengdu, China
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Park JH, Cho KI, Nam H, Choe NH, Suh JG. Anti-apoptotic effects of silk fibroin hydrolysate in RIN5F cell on high glucose condition. Anim Cells Syst (Seoul) 2015. [DOI: 10.1080/19768354.2015.1042045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Raúl BG, Antonio FLL, Arturo BGL, Miguel C, Rebeca GM, Alejandro ÁR, Alejandra CR, Margarita DF, Clara OC. Hyperglycemia promotes p53-Mdm2 interaction but reduces p53 ubiquitination in RINm5F cells. Mol Cell Biochem 2015; 405:257-64. [DOI: 10.1007/s11010-015-2416-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 04/18/2015] [Indexed: 12/31/2022]
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Yang SN, Shi Y, Yang G, Li Y, Yu J, Berggren PO. Ionic mechanisms in pancreatic β cell signaling. Cell Mol Life Sci 2014; 71:4149-77. [PMID: 25052376 PMCID: PMC11113777 DOI: 10.1007/s00018-014-1680-6] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 07/03/2014] [Accepted: 07/10/2014] [Indexed: 01/07/2023]
Abstract
The function and survival of pancreatic β cells critically rely on complex electrical signaling systems composed of a series of ionic events, namely fluxes of K(+), Na(+), Ca(2+) and Cl(-) across the β cell membranes. These electrical signaling systems not only sense events occurring in the extracellular space and intracellular milieu of pancreatic islet cells, but also control different β cell activities, most notably glucose-stimulated insulin secretion. Three major ion fluxes including K(+) efflux through ATP-sensitive K(+) (KATP) channels, the voltage-gated Ca(2+) (CaV) channel-mediated Ca(2+) influx and K(+) efflux through voltage-gated K(+) (KV) channels operate in the β cell. These ion fluxes set the resting membrane potential and the shape, rate and pattern of firing of action potentials under different metabolic conditions. The KATP channel-mediated K(+) efflux determines the resting membrane potential and keeps the excitability of the β cell at low levels. Ca(2+) influx through CaV1 channels, a major type of β cell CaV channels, causes the upstroke or depolarization phase of the action potential and regulates a wide range of β cell functions including the most elementary β cell function, insulin secretion. K(+) efflux mediated by KV2.1 delayed rectifier K(+) channels, a predominant form of β cell KV channels, brings about the downstroke or repolarization phase of the action potential, which acts as a brake for insulin secretion owing to shutting down the CaV channel-mediated Ca(2+) entry. These three ion channel-mediated ion fluxes are the most important ionic events in β cell signaling. This review concisely discusses various ionic mechanisms in β cell signaling and highlights KATP channel-, CaV1 channel- and KV2.1 channel-mediated ion fluxes.
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Affiliation(s)
- Shao-Nian Yang
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76, Stockholm, Sweden,
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Abstract
The early occurrence of β‐cell dysfunction has been broadly recognized as a critical determinant of the development and progression of type 2 diabetes. β‐cell dysfunction might be induced by insufficient β‐cell mass, by a dysfunction of the β‐cells, or both. Whether or not β‐cell dysfunction constitutes a cause of reduced β‐cells or vice‐versa currently remains unclear. The results of some studies have measured the loss of β‐cells in type 2 diabetic patients at between 22 and 63% by planimetric measurements. Because β‐cell hypertrophy has been noted in type 2 diabetic patients, the loss of β‐cell number should prove more profound than what has thus far been reported. Furthermore, β‐cell volumes are reduced even in patients with impaired fasting glucose. Such defects in β‐cell mass are associated with increased apoptosis rather than insufficient replication or neogenesis of β‐cells. With these results, although they still require clarification, the peak β‐cell mass might be determined at quite an early stage of life, and then might decline progressively over time as the result of exposure to harmful environmental influences over one’s lifetime. In this review, we have summarized the relevant studies regarding β‐cell mass in patients with type 2 diabetes, and then presented a review of the various causes of β‐cell loss in adults. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2010.00072.x, 2010)
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Affiliation(s)
- Jae-Hyoung Cho
- Department of Endocrinology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Ji-Won Kim
- Department of Endocrinology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Jeong-Ah Shin
- Department of Endocrinology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Juyoung Shin
- Department of Endocrinology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
| | - Kun-Ho Yoon
- Department of Endocrinology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea
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Shao Y, Yuan G, Feng Y, Zhang J, Guo X. Early liraglutide treatment is better in glucose control, β-cell function improvement and mass preservation in db/db mice. Peptides 2014; 52:134-42. [PMID: 24406898 DOI: 10.1016/j.peptides.2013.11.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/14/2013] [Accepted: 11/14/2013] [Indexed: 02/06/2023]
Abstract
Glucagon-like peptide-1 (GLP-1) has been proved to have effects of anti-hyperglycemia and β-cell preservation. However, it is still unclear whether there are differences between early and late GLP-1 intervention in type 2 diabetes mellitus (T2DM). We divided the mice into 5 groups: early treated group (n=7, 8-week old, fasting glucose>10mmol/l), late treated group (n=7, 10-week old, fasting glucose>20mmol/l), early control group (n=7), late control group (n=7) and wild type group (n=7). Treated group was injected with liraglutide (a GLP-1 analog) 300μg/kg bid for 4 weeks, while control group was given saline at the same time. The results showed that compared with control group, food intake and body weight gain were reduced in both early and late treated group (p<0.05), and there was no significance between the two treated groups. Early liraglutide intervention showed better improvements in glucose control, acute insulin response to glucose (AIRg) and disposition index (before vs. after treatment, AIRg 1.01±0.53 vs. 2.98±0.63, disposition index 10.81±0.89 vs. 27.4±2.15) than late intervention (AIRg 0.99±0.02 vs. 1.41±0.32, disposition index 3.47±0.38 vs. 6.43±1.62, p=0.001). The histopathology of the pancreas showed the estimated β-cell mass (BCM) was increased more in early treated group than that in late one (0.03 vs. 0.01g). Expressions of the proliferation related genes PDX-1, MafA and GLP-1 receptor (GLP-1R) in early treated group were 1.81, 2.57 and 1.59 times as much as that in late treated group. In conclusion, early liraglutide intervention was better in glucose control, β-cell function improvement and β-cell mass preservation.
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Affiliation(s)
- Yimin Shao
- Endocrinology Department, Peking University First Hospital, China
| | - Geheng Yuan
- Endocrinology Department, Peking University First Hospital, China.
| | - Yan Feng
- Huguosi Hospital of Traditional Chinese Medicine, China
| | - Junqing Zhang
- Endocrinology Department, Peking University First Hospital, China
| | - Xiaohui Guo
- Endocrinology Department, Peking University First Hospital, China
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Hong SH, Heo JI, Kim JH, Kwon SO, Yeo KM, Bakowska-Barczak AM, Kolodziejczyk P, Ryu OH, Choi MK, Kang YH, Lim SS, Suh HW, Huh SO, Lee JY. Antidiabetic and Beta cell-protection activities of purple corn anthocyanins. Biomol Ther (Seoul) 2013; 21:284-9. [PMID: 24244813 PMCID: PMC3819901 DOI: 10.4062/biomolther.2013.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 05/15/2013] [Accepted: 06/18/2013] [Indexed: 01/09/2023] Open
Abstract
Antidiabetic and beta cell-protection activities of purple corn anthocyanins (PCA) were examined in pancreatic beta cell culture and db/db mice. Only PCA among several plant anthocyanins and polyphenols showed insulin secretion activity in culture of HIT-T15 cells. PCA had excellent antihyperglycemic activity (in terms of blood glucose level and OGTT) and HbA1c-decreasing activity when compared with glimepiride, a sulfonylurea in db/db mice. In addition, PCA showed efficient protection activity of pancreatic beta cell from cell death in HIT-T15 cell culture and db/db mice. The result showed that PCA had antidiabetic and beta cell-protection activities in pancreatic beta cell culture and db/db mice.
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Affiliation(s)
- Su Hee Hong
- Department of Biochemistry, College of Medicine, Hallym University ; FrontBio Inc., Chuncheon 200-702, ; Institute of Cell Differentiation and Aging, College of Medicine, Hallym University, Chuncheon 200-702, Republic of Korea
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Patil SB, Dongare VR, Kulkarni CR, Joglekar MM, Arvindekar AU. Antidiabetic activity of Kalanchoe pinnata in streptozotocin-induced diabetic rats by glucose independent insulin secretagogue action. PHARMACEUTICAL BIOLOGY 2013; 51:1411-1418. [PMID: 23865837 DOI: 10.3109/13880209.2013.794364] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
CONTEXT Kalanchoe pinnata Lam. (Crassulaceae) is used as a traditional medicine worldwide to treat several ailments, including diabetes. However, the mechanism for the antihyperglycemic action is unknown. OBJECTIVE The present study evaluates the antihyperglycemic and insulin secretagogue potential of Kalanchoe pinnata and assessment of the probable mechanism of action. MATERIALS AND METHODS Steam distillate of Kalanchoe pinnata leaves was subjected to solvent fractionation and antidiabetic activity was detected in dichloromethane (DCM) fraction. In the in vivo studies, rats were treated with 5 and 10 mg/kg body weight of DCM fraction for 45 days orally. Lipid profile and other biochemical parameters were estimated. The probable mechanism for insulin secretagogue action was evaluated through studies using diazoxide and nifedipine. The bioactive component from DCM fraction was studied using HPTLC, GCMS and IR. RESULTS AND DISCUSSION Fasting blood glucose values were reduced to 116 mg/dl from 228 mg/dl on treatment with 10 mg/kg body weight of DCM fraction, while glycated hemoglobin improved to 8.4% compared with 12.9% in diabetic controls. The insulin level and lipid profile values were close to normal values. In vitro studies demonstrated a dose-dependent insulin secretagogue action. Insulin secretion was 3.29-fold higher at 10 µg/ml as compared to the positive control. The insulin secretagogue activity was glucose independent and K(+)-ATP channel dependent. The bioactive component of the DCM fraction was identified to be a phenyl alkyl ether derivative. CONCLUSION The DCM fraction of Kalanchoe pinnata demonstrates excellent insulin secretagogue action and can be useful in treatment of diabetes mellitus.
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Affiliation(s)
- Swapnil B Patil
- Department of Biochemistry, Shivaji University , Kolhapur, Maharashtra , India
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