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Azzarello F, Carli F, De Lorenzi V, Tesi M, Marchetti P, Beltram F, Raimondi F, Cardarelli F. Machine-learning-guided recognition of α and β cells from label-free infrared micrographs of living human islets of Langerhans. Sci Rep 2024; 14:14235. [PMID: 38902357 PMCID: PMC11190282 DOI: 10.1038/s41598-024-65161-7] [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: 02/25/2024] [Accepted: 06/17/2024] [Indexed: 06/22/2024] Open
Abstract
Human islets of Langerhans are composed mostly of glucagon-secreting α cells and insulin-secreting β cells closely intermingled one another. Current methods for identifying α and β cells involve either fixing islets and using immunostaining or disaggregating islets and employing flow cytometry for classifying α and β cells based on their size and autofluorescence. Neither approach, however, allows investigating the dynamic behavior of α and β cells in a living and intact islet. To tackle this issue, we present a machine-learning-based strategy for identification α and β cells in label-free infrared micrographs of living human islets without immunostaining. Intrinsic autofluorescence is stimulated by infrared light and collected both in intensity and lifetime in the visible range, dominated by NAD(P)H and lipofuscin signals. Descriptive parameters are derived from micrographs for ~ 103 cells. These parameters are used as input for a boosted decision-tree model (XGBoost) pre-trained with immunofluorescence-derived cell-type information. The model displays an optimized-metrics performance of 0.86 (i.e. area under a ROC curve), with an associated precision of 0.94 for the recognition of β cells and 0.75 for α cells. This tool promises to enable longitudinal studies on the dynamic behavior of individual cell types at single-cell resolution within the intact tissue.
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Affiliation(s)
| | - Francesco Carli
- Laboratorio di Biologia Bio@SNS, Scuola Normale Superiore, Pisa, Italy
| | | | - Marta Tesi
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Fabio Beltram
- NEST Laboratory, Scuola Normale Superiore, Pisa, Italy
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Lv J, Su M, Wang Y, Yang J, Liang Y, Chen L, Lei L. Yunvjian decoction mitigates hyperglycemia in rats induced by a high-fat diet and streptozotocin via reducing oxidative stress in pancreatic beta cells. JOURNAL OF ETHNOPHARMACOLOGY 2024; 327:118045. [PMID: 38479546 DOI: 10.1016/j.jep.2024.118045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/27/2024] [Accepted: 03/10/2024] [Indexed: 03/19/2024]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Yunvjian (YNJ), a traditional Chinese herbal formula first reported in Jing Yue Quan Shu, is commonly used in the clinical treatment of type 2 diabetes mellitus (T2DM). However, the mechanism by which YNJ affects T2DM remains unclear. AIM OF THE STUDY This study aimed to assess the therapeutic effects of YNJ on T2DM and explore the potential mechanism involved. MATERIALS AND METHODS High-performance liquid chromatography (HPLC) was used to identify the chemical compounds of YNJ. The anti-T2DM effects of YNJ were observed in a high-fat diet/streptozotocin induced rat model. The type 2 diabetic rats were prepared as follows: rats were fed a high-fat diet for four weeks and then intraperitoneally injected with a low dose (30 mg/kg) of streptozotocin. YNJ and the positive control metformin were used in these experiments. Biochemical assays were implemented to determine the fasting blood glucose, glucose tolerance, insulin sensitivity, serum lipid levels, and oxidative stress index of the pancreas. Hematoxylin-eosin (H&E) staining was used to assess histopathological alterations in the pancreas. The mechanism by which YNJ affects T2DM was evaluated in INS-1 cells treated with glucose and high sodium palmitate. YNJ-supplemented serum was used in these experiments. Methyl thiazolyl tetrazolium assays, enzyme-linked immunosorbent assays, Nile red staining, flow cytometric analysis, and Western blotting were used to assess apoptosis, insulin secretion, lipid accumulation, reactive oxygen species production, and protein levels. RESULTS Five major compounds were identified in YNJ. In high-fat diet/streptozotocin-induced diabetic rats, YNJ-M notably decreased fasting blood glucose and lipid levels; ameliorated glucose tolerance, insulin sensitivity, and islet morphology; reduced Malondialdehyde levels; and restored superoxide dismutase activity in the pancreatic islets. Furthermore, the effect of YNJ-M was significantly greater than that of YNJ-L, and YNJ-H had little effect on diabetic rats. In vitro experiments revealed that YNJ-supplemented serum (10%, 15%, and 20%) dramatically suppressed apoptosis, mitigated intracellular lipid accumulation and reduced intracellular oxidative stress levels in a dose-dependent manner. Additionally, YNJ-supplemented serum increased the protein expression of Nuclear factor erythroid 2-related factor 2, Heme oxygenase-1, and superoxide dismutase 1 and inhibited the protein expression of Kelch-like ECH-associated protein 1. CONCLUSION YNJ ameliorates high-fat diet/streptozotocin induced experimental T2DM. The underlying mechanism involves reducing oxidative stress in pancreatic beta cells. The findings of this study provide scientific justification for the application of the traditional medicine YNJ in treating T2DM.
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Affiliation(s)
- Jie Lv
- Co-construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry, State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), Shaanxi University of Chinese Medicine, Xianyang, 712083, China; Department of Pharmacology, Shaanxi University of Chinese Medicine & Key Laboratory of Pharmacodynamics and Material Basis of Chinese Medicine of Shaanxi Administration of Traditional Chinese Medicine & Engineering Research Center of Brain Health Industry of Chinese Medicine, Universities of Shaanxi Province, Xianyang, 712046, China.
| | - Meng Su
- Co-construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry, State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), Shaanxi University of Chinese Medicine, Xianyang, 712083, China; Department of Pharmacology, Shaanxi University of Chinese Medicine & Key Laboratory of Pharmacodynamics and Material Basis of Chinese Medicine of Shaanxi Administration of Traditional Chinese Medicine & Engineering Research Center of Brain Health Industry of Chinese Medicine, Universities of Shaanxi Province, Xianyang, 712046, China.
| | - Yansong Wang
- Co-construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry, State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), Shaanxi University of Chinese Medicine, Xianyang, 712083, China; Department of Pharmacology, Shaanxi University of Chinese Medicine & Key Laboratory of Pharmacodynamics and Material Basis of Chinese Medicine of Shaanxi Administration of Traditional Chinese Medicine & Engineering Research Center of Brain Health Industry of Chinese Medicine, Universities of Shaanxi Province, Xianyang, 712046, China
| | - Juan Yang
- Co-construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry, State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), Shaanxi University of Chinese Medicine, Xianyang, 712083, China; Department of Pharmacology, Shaanxi University of Chinese Medicine & Key Laboratory of Pharmacodynamics and Material Basis of Chinese Medicine of Shaanxi Administration of Traditional Chinese Medicine & Engineering Research Center of Brain Health Industry of Chinese Medicine, Universities of Shaanxi Province, Xianyang, 712046, China
| | - Yanni Liang
- Co-construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry, State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), Shaanxi University of Chinese Medicine, Xianyang, 712083, China; Department of Pharmacology, Shaanxi University of Chinese Medicine & Key Laboratory of Pharmacodynamics and Material Basis of Chinese Medicine of Shaanxi Administration of Traditional Chinese Medicine & Engineering Research Center of Brain Health Industry of Chinese Medicine, Universities of Shaanxi Province, Xianyang, 712046, China
| | - Lin Chen
- Co-construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry, State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), Shaanxi University of Chinese Medicine, Xianyang, 712083, China; Department of Pharmacology, Shaanxi University of Chinese Medicine & Key Laboratory of Pharmacodynamics and Material Basis of Chinese Medicine of Shaanxi Administration of Traditional Chinese Medicine & Engineering Research Center of Brain Health Industry of Chinese Medicine, Universities of Shaanxi Province, Xianyang, 712046, China
| | - Liyan Lei
- Co-construction Collaborative Innovation Center for Chinese Medicine Resources Industrialization by Shaanxi & Education Ministry, State Key Laboratory of Research & Development of Characteristic Qin Medicine Resources (Cultivation), Shaanxi University of Chinese Medicine, Xianyang, 712083, China; Department of Pharmacology, Shaanxi University of Chinese Medicine & Key Laboratory of Pharmacodynamics and Material Basis of Chinese Medicine of Shaanxi Administration of Traditional Chinese Medicine & Engineering Research Center of Brain Health Industry of Chinese Medicine, Universities of Shaanxi Province, Xianyang, 712046, China.
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3
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Du Q, Wu X, Ma K, Liu W, Liu P, Hayashi T, Mizuno K, Hattori S, Fujisaki H, Ikejima T. Silibinin alleviates ferroptosis of rat islet β cell INS-1 induced by the treatment with palmitic acid and high glucose through enhancing PINK1/parkin-mediated mitophagy. Arch Biochem Biophys 2023:109644. [PMID: 37245586 DOI: 10.1016/j.abb.2023.109644] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/16/2023] [Accepted: 05/19/2023] [Indexed: 05/30/2023]
Abstract
Type 2 diabetes (T2DM) is induced by the abundance of glucose and lipids, which causes glucolipotoxicity to the pancreatic β-cells. Silibinin is a natural flavonoid possessing the regulatory activity on insulin production and therapeutic activity in diabetic mice; however, its effect on glucolipotoxicity is not fully explained. This in vitro study investigates the effects of silibinin on palmitic acid (PA) and high glucose (HG)-induced cell loss and ferroptosis of rat insulinoma INS-1 cells. In the cells treated with PA and HG, expressions of glucose transporter 4 (Glut4) and carnitine acyltransferase I (CPT1) for β-oxidation of fatty acids are reduced. Mitochondria are the metabolic organelles for glucose and fatty acids. The mitochondrial membrane potential (MMP) and ATP production were decreased, while the ROS level was elevated in the cells treated with PA and HG, indicating an induction of mitochondrial disorder. Cell loss was partially rescued by ferroptosis inhibition, suggesting an involvement of ferroptosis in the cells treated with PA and HG. More importantly, the increases in total iron, lipid ROS, MDA and COX-2, and the decrease in ferroptosis inhibitory molecules GSH, GPX4 and FSP1 appeared in the cells treated with PA and HG, confirming the occurrence of ferroptosis. Moreover, PINK1/parkin-mediated mitophagy, a vital process for selective elimination of damaged mitochondria, was blocked. Interestingly, silibinin rescued the mitochondria, restricted the ferroptosis and restored the mitophagy. By using the pharmacological stimulator and inhibitor of mitophagy, and si-RNA transfection to silence PINK1 expression, silibinin's protective effect against ferroptosis caused by PA and HG treatment was found to depend on mitophagy. Collectively, our current study reveals the new mechanisms for the protection of silibinin against the injury of INS-1 cells treated with PA and HG, elucidates the participation of ferroptosis in glucolipotoxicity, highlighting the involvement of mitophagy in defense against ferroptotic cell death.
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Affiliation(s)
- Qingqing Du
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China
| | - Xiaoyun Wu
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China
| | - Kai Ma
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China
| | - Weiwei Liu
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China
| | - Panwen Liu
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China
| | - Toshihiko Hayashi
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China; Nippi Research Institute of Biomatrix, Toride, Ibaraki, 302-0017, Japan
| | - Kazunori Mizuno
- Nippi Research Institute of Biomatrix, Toride, Ibaraki, 302-0017, Japan
| | - Shunji Hattori
- Nippi Research Institute of Biomatrix, Toride, Ibaraki, 302-0017, Japan
| | - Hitomi Fujisaki
- Nippi Research Institute of Biomatrix, Toride, Ibaraki, 302-0017, Japan
| | - Takashi Ikejima
- Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, Liaoning, China; Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research & Development, Liaoning, China.
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Stojanovic J, Andjelic-Jelic M, Vuksanovic M, Marjanovic-Petkovic M, Jojic B, Stojanovic M, Beljic-Zivkovic T. The effects of early short-term insulin treatment vs. glimepiride on beta cell function in newly diagnosed type 2 diabetes with HbA1c above 9. Turk J Med Sci 2023; 53:552-562. [PMID: 37476884 PMCID: PMC10387975 DOI: 10.55730/1300-0144.5616] [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: 09/18/2022] [Accepted: 01/20/2023] [Indexed: 07/22/2023] Open
Abstract
BACKGROUND Type 2 diabetes mellitus (T2D) is a complex metabolic impairment. Beta cell (BC) failure is the most challenging among its pathogenetic mechanisms. Recognizing reversible contributors to BC failure could guide individualized approach to early T2D treatment. The aim of this study was to compare early short-term insulin treatment vs. glimepiride, both added to metformin, on BC function, glycemic and lipid control, during 12-month follow-up. METHODS Eighty newly diagnosed T2D patients, 30-65 years of age, presenting with HbA1c ≥ 9% were enrolled in the study. They were randomly assigned to single-month initial insulin therapy (INS) added to metformin, or to glimepiride and metformin (OAD) as only treatment. Subjects assigned to initial insulin intervention were thereafter switched to OAD. C-peptide (C-Pep) was analyzed at baseline and 2 hours after standardized test meal (STM). All subjects were STM-retested after 3 and 12 months. HbA1c, serum lipids, BMI, HOMA IR, and HOMA B were assessed over follow-up. RESULTS HbA1c was lower in INS vs OAD at 3-months: 6.26 ± 0.18% vs 6.78 ± 0.10% (p = 0.016), remaining so by 12 months (p =0.056). BMI-adjusted ΔC-Pep was greater in INS vs. OAD at 3 months (4.60 ± 0.59 vs. 3.21 ± 0.34 m2 /kg; p = 0.044), persisting by 12months (4.57 ± 0.56 vs. 3.04 ± 0.34 m2/kg; p = 0.023). Average ΔC-Pep improvement from recruitment to 3 months was 100.8% in INS,vs. 51.3% in OAD. Prevalence of STM-ΔC-Pep response greater than 2.4 ng/mL had risen 3.2-fold by 12 months in the INS, vs. 2.4-fold only in the OAD group (p = 0.018). DISCUSSION Early short-term insulin intervention in newly diagnosed T2D improves beta cell function more than glimepiride, both added to metformin, resulting in a superior and longer lasting glycemic and lipid control.
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Affiliation(s)
- Jelena Stojanovic
- Division of Endocrinology, Diabetes and Metabolic Disorders, Department of Internal Medicine, Zvezdara University Medical Center, Belgrade, Serbia
| | - Marina Andjelic-Jelic
- Department of Internal Medicine, Faculty of Dental Medicine, University of Belgrade, Belgrade, Serbia ; Division of Endocrinology, Diabetes and Metabolic Disorders, Department of Internal Medicine,Zvezdara University Medical Center, Belgrade, Serbia
| | - Miljanka Vuksanovic
- Department of Internal Medicine, Medical Faculty,University of Belgrade, Belgrade, Serbia ; Division of Endocrinology, Diabetes and Metabolic Disorders, Department of Internal Medicine,Zvezdara University Medical Center, Belgrade, Serbia
| | - Milica Marjanovic-Petkovic
- Department of Internal Medicine, Medical Faculty,University of Belgrade, Belgrade, Serbia; Division of Endocrinology, Diabetes and Metabolic Disorders, Department of Internal Medicine,Zvezdara University Medical Center, Belgrade, Serbia
| | - Biljana Jojic
- Division of Endocrinology, Diabetes and Metabolic Disorders, Department of Internal Medicine,Zvezdara University Medical Center, Belgrade, Serbia
| | - Marko Stojanovic
- Department of Internal Medicine, Medical Faculty,University of Belgrade, Belgrade, Serbia ; Department of Neuroendocrinology, Clinic for Endocrinology, Diabetes and Metabolic Diseases,University Clinical Center of Serbia, Belgrade, Serbia
| | - Teodora Beljic-Zivkovic
- Department of Internal Medicine, Medical Faculty,University of Belgrade, Belgrade, Serbia;Division of Endocrinology, Diabetes and Metabolic Disorders, Department of Internal Medicine,Zvezdara University Medical Center, Belgrade, Serbia
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5
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Basu L, Bhagat V, Ching MEA, Di Giandomenico A, Dostie S, Greenberg D, Greenberg M, Hahm J, Hilton NZ, Lamb K, Jentz EM, Larsen M, Locatelli CAA, Maloney M, MacGibbon C, Mersali F, Mulchandani CM, Najam A, Singh I, Weisz T, Wong J, Senior PA, Estall JL, Mulvihill EE, Screaton RA. Recent Developments in Islet Biology: A Review With Patient Perspectives. Can J Diabetes 2023; 47:207-221. [PMID: 36481263 PMCID: PMC9640377 DOI: 10.1016/j.jcjd.2022.11.003] [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: 09/01/2022] [Revised: 10/24/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022]
Abstract
Navigating the coronavirus disease-2019 (COVID-19, now COVID) pandemic has required resilience and creativity worldwide. Despite early challenges to productivity, more than 2,000 peer-reviewed articles on islet biology were published in 2021. Herein, we highlight noteworthy advances in islet research between January 2021 and April 2022, focussing on 5 areas. First, we discuss new insights into the role of glucokinase, mitogen-activated protein kinase-kinase/extracellular signal-regulated kinase and mitochondrial function on insulin secretion from the pancreatic β cell, provided by new genetically modified mouse models and live imaging. We then discuss a new connection between lipid handling and improved insulin secretion in the context of glucotoxicity, focussing on fatty acid-binding protein 4 and fetuin-A. Advances in high-throughput "omic" analysis evolved to where one can generate more finely tuned genetic and molecular profiles within broad classifications of type 1 diabetes and type 2 diabetes. Next, we highlight breakthroughs in diabetes treatment using stem cell-derived β cells and innovative strategies to improve islet survival posttransplantation. Last, we update our understanding of the impact of severe acute respiratory syndrome-coronavirus-2 infection on pancreatic islet function and discuss current evidence regarding proposed links between COVID and new-onset diabetes. We address these breakthroughs in 2 settings: one for a scientific audience and the other for the public, particularly those living with or affected by diabetes. Bridging biomedical research in diabetes to the community living with or affected by diabetes, our partners living with type 1 diabetes or type 2 diabetes also provide their perspectives on these latest advances in islet biology.
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Affiliation(s)
- Lahari Basu
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | - Vriti Bhagat
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada; BC Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Ma Enrica Angela Ching
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | | | - Sylvie Dostie
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Dana Greenberg
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Marley Greenberg
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Jiwon Hahm
- Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - N Zoe Hilton
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Krista Lamb
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Emelien M Jentz
- School of Pharmacy, University of Waterloo, Kitchener, Ontario, Canada
| | - Matt Larsen
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Cassandra A A Locatelli
- University of Ottawa Heart Institute, Energy Substrate Laboratory, Ottawa, Ontario, Canada; Department of Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa, Ontario, Canada
| | - MaryAnn Maloney
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | | | - Farida Mersali
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | | | - Adhiyat Najam
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Ishnoor Singh
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Tom Weisz
- Diabetes Action Canada, Toronto General Hospital, Toronto, Ontario, Canada
| | - Jordan Wong
- Alberta Diabetes Institute and Department of Pharmacology, Li Ka Shing Centre for Health Research Innovation, University of Alberta, Edmonton, Alberta, Canada; Alberta Diabetes Institute and Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Peter A Senior
- Alberta Diabetes Institute and Department of Medicine, Edmonton, Alberta, Canada
| | - Jennifer L Estall
- Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada; Institut de recherches cliniques de Montréal, Center for Cardiometabolic Health, Montréal, Québec, Canada
| | - Erin E Mulvihill
- University of Ottawa Heart Institute, Energy Substrate Laboratory, Ottawa, Ontario, Canada; Department of Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa, Ontario, Canada
| | - Robert A Screaton
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Research Institute, Toronto, Ontario, Canada.
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Sharifi S, Böger M, Lortz S, Mehmeti I. Luminal H 2 O 2 promotes ER Ca 2+ dysregulation and toxicity of palmitate in insulin-secreting INS-1E cells. FASEB J 2023; 37:e22685. [PMID: 36468845 DOI: 10.1096/fj.202201237r] [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: 08/03/2022] [Revised: 11/07/2022] [Accepted: 11/21/2022] [Indexed: 12/12/2022]
Abstract
The endoplasmic reticulum (ER) lumen is not only the major site for the assembly and folding of newly synthesized proteins but also the main intracellular Ca2+ store. Ca2+ ions are involved in versatile biochemical processes, including posttranslational processing and folding of nascent proteins. Disruption of ER Ca2+ homeostasis is usually accompanied by an ER stress response that can ultimately lead to apoptosis if unresolved. Abnormal ER Ca2+ depletion has been linked to pancreatic β-cell dysfunction and death under lipotoxic conditions. However, the underlying mechanisms how the β-cell toxic saturated free fatty acid palmitate perturbs ER Ca2+ homeostasis and its interplay with other organelles are not fully understood. In the present study, we demonstrate that treatment of insulin-secreting INS-1E cells with palmitate diminished ER Ca2+ levels, elevated cytosolic/mitochondrial Ca2+ content, lowered the mitochondrial membrane potential, and ATP content. In addition, palmitate-pretreated β-cells contained significantly less luminal Ca2+ , revealed a severely impaired ER Ca2+ reuptake rate, and substantially lower insulin content. Importantly, detoxification of luminal H2 O2 by expression of the ER-resident glutathione peroxidase 8 (GPx8) abrogated the lipotoxic effects of palmitate. Moreover, GPx8 supported oxidative protein folding and preserved insulin content under lipotoxic conditions. A direct involvement of luminal H2 O2 in palmitate-mediated ER Ca2+ depletion could be corroborated by the ectopic expression of an ER-luminal active catalase. Our data point to the critical role of luminal H2 O2 in palmitate-mediated depletion of ER Ca2+ through redox-dependent impairment of Ca2+ ATPase pump activity upstream of mitochondrial dysfunction in insulin-secreting INS-1E cells.
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Affiliation(s)
- Sarah Sharifi
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Maren Böger
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Stephan Lortz
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Ilir Mehmeti
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
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Kalwat MA, Rodrigues-dos-Santos K, Binns DD, Wei S, Zhou A, Evans MR, Posner BA, Roth MG, Cobb MH. Small molecule glucagon release inhibitors with activity in human islets. Front Endocrinol (Lausanne) 2023; 14:1114799. [PMID: 37152965 PMCID: PMC10157210 DOI: 10.3389/fendo.2023.1114799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 04/07/2023] [Indexed: 05/09/2023] Open
Abstract
Purpose Type 1 diabetes (T1D) accounts for an estimated 5% of all diabetes in the United States, afflicting over 1.25 million individuals. Maintaining long-term blood glucose control is the major goal for individuals with T1D. In T1D, insulin-secreting pancreatic islet β-cells are destroyed by the immune system, but glucagon-secreting islet α-cells survive. These remaining α-cells no longer respond properly to fluctuating blood glucose concentrations. Dysregulated α-cell function contributes to hyper- and hypoglycemia which can lead to macrovascular and microvascular complications. To this end, we sought to discover small molecules that suppress α-cell function for their potential as preclinical candidate compounds. Prior high-throughput screening identified a set of glucagon-suppressing compounds using a rodent α-cell line model, but these compounds were not validated in human systems. Results Here, we dissociated and replated primary human islet cells and exposed them to 24 h treatment with this set of candidate glucagon-suppressing compounds. Glucagon accumulation in the medium was measured and we determined that compounds SW049164 and SW088799 exhibited significant activity. Candidate compounds were also counter-screened in our InsGLuc-MIN6 β-cell insulin secretion reporter assay. SW049164 and SW088799 had minimal impact on insulin release after a 24 h exposure. To further validate these hits, we treated intact human islets with a selection of the top candidates for 24 h. SW049164 and SW088799 significantly inhibited glucagon release into the medium without significantly altering whole islet glucagon or insulin content. In concentration-response curves SW088799 exhibited significant inhibition of glucagon release with an IC50 of 1.26 µM. Conclusion Given the set of tested candidates were all top hits from the primary screen in rodent α-cells, this suggests some conservation of mechanism of action between human and rodents, at least for SW088799. Future structure-activity relationship studies of SW088799 may aid in elucidating its protein target(s) or enable its use as a tool compound to suppress α-cell activity in vitro.
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Affiliation(s)
- Michael A. Kalwat
- Lilly Diabetes Center of Excellence, Indiana Biosciences Research Institute, Indianapolis, IN, United States
- Indiana University School of Medicine, Center for Diabetes and Metabolic Diseases, Indianapolis, IN, United States
- *Correspondence: Michael A. Kalwat, ;
| | - Karina Rodrigues-dos-Santos
- Lilly Diabetes Center of Excellence, Indiana Biosciences Research Institute, Indianapolis, IN, United States
| | - Derk D. Binns
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Shuguang Wei
- Department Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Anwu Zhou
- Department Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Matthew R. Evans
- Department Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Bruce A. Posner
- Department Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Michael G. Roth
- Department Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Melanie H. Cobb
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, United States
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Vivoli A, Ghislain J, Filali-Mouhim A, Angeles ZE, Castell AL, Sladek R, Poitout V. Single-Cell RNA Sequencing Reveals a Role for Reactive Oxygen Species and Peroxiredoxins in Fatty Acid-Induced Rat β-Cell Proliferation. Diabetes 2023; 72:45-58. [PMID: 36191509 PMCID: PMC9797324 DOI: 10.2337/db22-0121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 09/24/2022] [Indexed: 01/19/2023]
Abstract
The functional mass of insulin-secreting pancreatic β-cells expands to maintain glucose homeostasis in the face of nutrient excess, in part via replication of existing β-cells. Type 2 diabetes appears when these compensatory mechanisms fail. Nutrients including glucose and fatty acids are important contributors to the β-cell compensatory response, but their underlying mechanisms of action remain poorly understood. We investigated the transcriptional mechanisms of β-cell proliferation in response to fatty acids. Isolated rat islets were exposed to 16.7 mmol/L glucose with or without 0.5 mmol/L oleate (C18:1) or palmitate (C16:0) for 48 h. The islet transcriptome was assessed by single-cell RNA sequencing. β-Cell proliferation was measured by flow cytometry. Unsupervised clustering of pooled β-cells identified different subclusters, including proliferating β-cells. β-Cell proliferation increased in response to oleate but not palmitate. Both fatty acids enhanced the expression of genes involved in energy metabolism and mitochondrial activity. Comparison of proliferating versus nonproliferating β-cells and pseudotime ordering suggested the involvement of reactive oxygen species (ROS) and peroxiredoxin signaling. Accordingly, N-acetyl cysteine and the peroxiredoxin inhibitor conoidin A both blocked oleate-induced β-cell proliferation. Our study reveals a key role for ROS signaling through peroxiredoxin activation in oleate-induced β-cell proliferation.
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Affiliation(s)
- Alexis Vivoli
- Montreal Diabetes Research Center, Montréal, Québec, Canada
- Department of Medicine, Université de Montréal, Montréal, Québec, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Québec, Canada
| | - Julien Ghislain
- Montreal Diabetes Research Center, Montréal, Québec, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Québec, Canada
| | - Ali Filali-Mouhim
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Québec, Canada
| | - Zuraya Elisa Angeles
- Montreal Diabetes Research Center, Montréal, Québec, Canada
- Department of Medicine, Université de Montréal, Montréal, Québec, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Québec, Canada
| | - Anne-Laure Castell
- Montreal Diabetes Research Center, Montréal, Québec, Canada
- Department of Medicine, Université de Montréal, Montréal, Québec, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Québec, Canada
| | - Robert Sladek
- Montreal Diabetes Research Center, Montréal, Québec, Canada
- Department of Human Genetics, McGill University and McGill Genome Centre, Montréal, Québec, Canada
| | - Vincent Poitout
- Montreal Diabetes Research Center, Montréal, Québec, Canada
- Department of Medicine, Université de Montréal, Montréal, Québec, Canada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Montréal, Québec, Canada
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Li Z, Yue Q, Chen Y, Zhang Y, Wan Y. Quantitative Assessment of Pancreatic Fat by Quantitative CT in Type 2 Diabetes Mellitus. Int J Gen Med 2022; 15:7977-7984. [PMID: 36337672 PMCID: PMC9629247 DOI: 10.2147/ijgm.s383783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 10/17/2022] [Indexed: 11/07/2022] Open
Abstract
Objective To characterize the pancreatic fat deposition (PFD) in patients with type 2 diabetes mellitus (T2DM) by quantitative computed tomography (QCT) and investigate the relationship between PFD and clinical metabolic parameters and islet function. Materials and Methods A total of 150 patients with T2DM and 93 age-matched healthy subjects underwent QCT to quantify PFD were included. PFD and various biochemical parameters were correlated by statistical methods and multiple stepwise linear regression modeling. Results PFD measured by QCT in the T2DM group was statistically higher than that in the healthy control group, and the pancreatic CT value was statistically lower than that in the control group. The QCT measured PFD was negatively correlated with the pancreatic CT values (P < 0.001), and positively correlated with triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), visceral fat area (VAT) and insulin resistance index (HOMA-IR) (P < 0.05) in the T2DM patients. Multiple stepwise linear regression analysis identified PFD as the dependent variable factor for T2DM. Conclusion This study suggests QCT as a reliable technique in measuring PFD in T2DM. High PFD is positively correlated with the degree of insulin resistance and may play an important role in islet cell dysfunction in T2DM.
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Affiliation(s)
- Zhizhen Li
- Department of Endocrinology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People’s Republic of China
| | - Qingmei Yue
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People’s Republic of China
| | - Yunjin Chen
- Department of Endocrinology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People’s Republic of China
| | - Yifan Zhang
- Department of Endocrinology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People’s Republic of China
| | - Yamin Wan
- Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People’s Republic of China
- Correspondence: Yamin Wan, Email
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Ceramide Acyl Chain Length and Its Relevance to Intracellular Lipid Regulation. Int J Mol Sci 2022; 23:ijms23179697. [PMID: 36077094 PMCID: PMC9456274 DOI: 10.3390/ijms23179697] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/19/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022] Open
Abstract
Ceramides are a class of sphingolipids which are implicated in skin disorders, obesity, and other metabolic diseases. As a class with pleiotropic effects, recent efforts have centred on discerning specific ceramide species and their effects on atopic dermatitis, obesity, type 2 diabetes, and cardiovascular diseases. This delineation has allowed the identification of disease biomarkers, with long acyl chain ceramides such as C16- and C18-ceramides linked to metabolic dysfunction and cardiac function decline, while ultra-long acyl chain ceramides (>25 carbon acyl chain) were reported to be essential for maintaining a functional skin barrier. Given the intricate link between free fatty acids with ceramides, especially the de novo synthetic pathway, intracellular lipid droplet formation is increasingly viewed as an important mechanism for preventing accumulation of toxic ceramide species. Here, we review recent reports of various ceramide species involved in skin abnormalities and metabolic diseases, and we propose that promotion of lipid droplet biogenesis can be seen as a potential protective mechanism against deleterious ceramides.
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11
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Pankreatische Betazellen, Glukolipotoxizität, NEFA-Zyklus und Insulinsekretion. DIABETOL STOFFWECHS 2022. [DOI: 10.1055/a-1732-9854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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