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Johansen CG, Holcomb K, Sela A, Morrall S, Park D, Farnsworth NL. Extracellular matrix stiffness mediates insulin secretion in pancreatic islets via mechanosensitive Piezo1 channel regulated Ca 2+ dynamics. Matrix Biol Plus 2024; 22:100148. [PMID: 38803329 PMCID: PMC11128509 DOI: 10.1016/j.mbplus.2024.100148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/29/2024] Open
Abstract
The pancreatic islet is surrounded by ECM that provides both biochemical and mechanical cues to the islet β-cell to regulate cell survival and insulin secretion. Changes in ECM composition and mechanical properties drive β-cell dysfunction in many pancreatic diseases. While several studies have characterized changes in islet insulin secretion with changes in substrate stiffness, little is known about the mechanotransduction signaling driving altered islet function in response to mechanical cues. We hypothesized that increasing matrix stiffness will lead to insulin secretion dysfunction by opening the mechanosensitive ion channel Piezo1 and disrupting intracellular Ca2+ dynamics in mouse and human islets. To test our hypothesis, mouse and human cadaveric islets were encapsulated in a biomimetic reverse thermal gel (RTG) scaffold with tailorable stiffness that allows formation of islet focal adhesions with the scaffold and activation of Piezo1 in 3D. Our results indicate that increased scaffold stiffness causes insulin secretion dysfunction mediated by increases in Ca2+ influx and altered Ca2+ dynamics via opening of the mechanosensitive Piezo1 channel. Additionally, inhibition of Piezo1 rescued glucose-stimulated insulin secretion (GSIS) in islets in stiff scaffolds. Overall, our results emphasize the role mechanical properties of the islet microenvironment plays in regulating function. It also supports further investigation into the modulation of Piezo1 channel activity to restore islet function in diseases like type 2 diabetes (T2D) and pancreatic cancer where fibrosis of the peri-islet ECM leads to increased tissue stiffness and islet dysfunction.
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Affiliation(s)
- Chelsea G Johansen
- Department of Chemical & Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Keifer Holcomb
- Department of Chemical & Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Amit Sela
- Quantitative Biosciences & Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Stephanie Morrall
- Quantitative Biosciences & Engineering, Colorado School of Mines, Golden, CO 80401, USA
| | - Daewon Park
- Department of Bioengineering, University of Colorado Denver Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Nikki L Farnsworth
- Department of Chemical & Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
- Quantitative Biosciences & Engineering, Colorado School of Mines, Golden, CO 80401, USA
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2
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James EA, Joglekar AV, Linnemann AK, Russ HA, Kent SC. The beta cell-immune cell interface in type 1 diabetes (T1D). Mol Metab 2023; 78:101809. [PMID: 37734713 PMCID: PMC10622886 DOI: 10.1016/j.molmet.2023.101809] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Revised: 09/01/2023] [Accepted: 09/15/2023] [Indexed: 09/23/2023] Open
Abstract
BACKGROUND T1D is an autoimmune disease in which pancreatic islets of Langerhans are infiltrated by immune cells resulting in the specific destruction of insulin-producing islet beta cells. Our understanding of the factors leading to islet infiltration and the interplay of the immune cells with target beta cells is incomplete, especially in human disease. While murine models of T1D have provided crucial information for both beta cell and autoimmune cell function, the translation of successful therapies in the murine model to human disease has been a challenge. SCOPE OF REVIEW Here, we discuss current state of the art and consider knowledge gaps concerning the interface of the islet beta cell with immune infiltrates, with a focus on T cells. We discuss pancreatic and immune cell phenotypes and their impact on cell function in health and disease, which we deem important to investigate further to attain a more comprehensive understanding of human T1D disease etiology. MAJOR CONCLUSIONS The last years have seen accelerated development of approaches that allow comprehensive study of human T1D. Critically, recent studies have contributed to our revised understanding that the pancreatic beta cell assumes an active role, rather than a passive position, during autoimmune disease progression. The T cell-beta cell interface is a critical axis that dictates beta cell fate and shapes autoimmune responses. This includes the state of the beta cell after processing internal and external cues (e.g., stress, inflammation, genetic risk) that that contributes to the breaking of tolerance by hyperexpression of human leukocyte antigen (HLA) class I with presentation of native and neoepitopes and secretion of chemotactic factors to attract immune cells. We anticipate that emerging insights about the molecular and cellular aspects of disease initiation and progression processes will catalyze the development of novel and innovative intervention points to provide additional therapies to individuals affected by T1D.
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Affiliation(s)
- Eddie A James
- Center for Translational Immunology, Benaroya Research Institute, Seattle, WA, USA
| | - Alok V Joglekar
- Center for Systems Immunology and Department of Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Amelia K Linnemann
- Center for Diabetes and Metabolic Diseases, and Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Holger A Russ
- Diabetes Institute, University of Florida, Gainesville, FL, USA; Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - Sally C Kent
- Diabetes Center of Excellence, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, MA, USA.
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3
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Wagner LE, Melnyk O, Duffett BE, Linnemann AK. Mouse models and human islet transplantation sites for intravital imaging. Front Endocrinol (Lausanne) 2022; 13:992540. [PMID: 36277698 PMCID: PMC9579277 DOI: 10.3389/fendo.2022.992540] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/09/2022] [Indexed: 01/12/2023] Open
Abstract
Human islet transplantations into rodent models are an essential tool to aid in the development and testing of islet and cellular-based therapies for diabetes prevention and treatment. Through the ability to evaluate human islets in an in vivo setting, these studies allow for experimental approaches to answer questions surrounding normal and disease pathophysiology that cannot be answered using other in vitro and in vivo techniques alone. Intravital microscopy enables imaging of tissues in living organisms with dynamic temporal resolution and can be employed to measure biological processes in transplanted human islets revealing how experimental variables can influence engraftment, and transplant survival and function. A key consideration in experimental design for transplant imaging is the surgical placement site, which is guided by the presence of vasculature to aid in functional engraftment of the islets and promote their survival. Here, we review transplantation sites and mouse models used to study beta cell biology in vivo using intravital microscopy and we highlight fundamental observations made possible using this methodology.
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Affiliation(s)
- Leslie E. Wagner
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Olha Melnyk
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Bryce E. Duffett
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Amelia K. Linnemann
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, United States
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, United States
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4
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Patel SN, Mathews CE, Chandler R, Stabler CL. The Foundation for Engineering a Pancreatic Islet Niche. Front Endocrinol (Lausanne) 2022; 13:881525. [PMID: 35600597 PMCID: PMC9114707 DOI: 10.3389/fendo.2022.881525] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 03/30/2022] [Indexed: 12/01/2022] Open
Abstract
Progress in diabetes research is hindered, in part, by deficiencies in current experimental systems to accurately model human pathophysiology and/or predict clinical outcomes. Engineering human-centric platforms that more closely mimic in vivo physiology, however, requires thoughtful and informed design. Summarizing our contemporary understanding of the unique and critical features of the pancreatic islet can inform engineering design criteria. Furthermore, a broad understanding of conventional experimental practices and their current advantages and limitations ensures that new models address key gaps. Improving beyond traditional cell culture, emerging platforms are combining diabetes-relevant cells within three-dimensional niches containing dynamic matrices and controlled fluidic flow. While highly promising, islet-on-a-chip prototypes must evolve their utility, adaptability, and adoptability to ensure broad and reproducible use. Here we propose a roadmap for engineers to craft biorelevant and accessible diabetes models. Concurrently, we seek to inspire biologists to leverage such tools to ask complex and nuanced questions. The progenies of such diabetes models should ultimately enable investigators to translate ambitious research expeditions from benchtop to the clinic.
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Affiliation(s)
- Smit N. Patel
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Clayton E. Mathews
- Department of Pathology, Immunology, and Laboratory Medicine, University of Florida, Gainesville, FL, United States
- Diabetes Institute, University of Florida, Gainesville, FL, United States
| | - Rachel Chandler
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
| | - Cherie L. Stabler
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, United States
- Diabetes Institute, University of Florida, Gainesville, FL, United States
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5
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Sidarala V, Zhu J, Levi-D'Ancona E, Pearson GL, Reck EC, Walker EM, Kaufman BA, Soleimanpour SA. Mitofusin 1 and 2 regulation of mitochondrial DNA content is a critical determinant of glucose homeostasis. Nat Commun 2022; 13:2340. [PMID: 35487893 PMCID: PMC9055072 DOI: 10.1038/s41467-022-29945-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 03/21/2022] [Indexed: 02/01/2023] Open
Abstract
The dynamin-like GTPases Mitofusin 1 and 2 (Mfn1 and Mfn2) are essential for mitochondrial function, which has been principally attributed to their regulation of fission/fusion dynamics. Here, we report that Mfn1 and 2 are critical for glucose-stimulated insulin secretion (GSIS) primarily through control of mitochondrial DNA (mtDNA) content. Whereas Mfn1 and Mfn2 individually were dispensable for glucose homeostasis, combined Mfn1/2 deletion in β-cells reduced mtDNA content, impaired mitochondrial morphology and networking, and decreased respiratory function, ultimately resulting in severe glucose intolerance. Importantly, gene dosage studies unexpectedly revealed that Mfn1/2 control of glucose homeostasis was dependent on maintenance of mtDNA content, rather than mitochondrial structure. Mfn1/2 maintain mtDNA content by regulating the expression of the crucial mitochondrial transcription factor Tfam, as Tfam overexpression ameliorated the reduction in mtDNA content and GSIS in Mfn1/2-deficient β-cells. Thus, the primary physiologic role of Mfn1 and 2 in β-cells is coupled to the preservation of mtDNA content rather than mitochondrial architecture, and Mfn1 and 2 may be promising targets to overcome mitochondrial dysfunction and restore glucose control in diabetes.
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Affiliation(s)
- Vaibhav Sidarala
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Jie Zhu
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Elena Levi-D'Ancona
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Gemma L Pearson
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Emma C Reck
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Emily M Walker
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Brett A Kaufman
- Vascular Medicine Institute, Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States
| | - Scott A Soleimanpour
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States.
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48105, United States.
- VA Ann Arbor Healthcare System, Ann Arbor, MI, 48105, United States.
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6
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Jacobelli J, Buser AE, Heiden DL, Friedman RS. Autoimmunity in motion: Mechanisms of immune regulation and destruction revealed by in vivo imaging. Immunol Rev 2022; 306:181-199. [PMID: 34825390 PMCID: PMC9135487 DOI: 10.1111/imr.13043] [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: 11/01/2021] [Accepted: 11/06/2021] [Indexed: 11/30/2022]
Abstract
Autoimmunity arises when mechanisms of immune tolerance fail. Here we discuss mechanisms of T cell activation and tolerance and the dynamics of the autoimmune response at the site of disease. Live imaging of autoimmunity provides the ability to analyze immune cell dynamics at the single-cell level within the complex intact environment where disease occurs. These analyses have revealed mechanisms of T cell activation and tolerance in the lymph nodes, mechanisms of T cell entry into sites of autoimmune disease, and mechanisms leading to pathogenesis or protection in the autoimmune lesions. The overarching conclusions point to stable versus transient T cell antigen presenting cell interactions dictating the balance between T cell activation and tolerance, and T cell restimulation as a driver of pathogenesis at the site of autoimmunity. Findings from models of multiple sclerosis and type 1 diabetes are highlighted, however, the results have implications for basic mechanisms of T cell regulation during immune responses, tumor immunity, and autoimmunity.
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Affiliation(s)
- Jordan Jacobelli
- Barbara Davis Center for Diabetes, Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Alan E. Buser
- Barbara Davis Center for Diabetes, Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Dustin L. Heiden
- Barbara Davis Center for Diabetes, Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Rachel S. Friedman
- Barbara Davis Center for Diabetes, Department of Immunology & Microbiology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
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7
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Coppola A, Zorzetto G, Piacentino F, Bettoni V, Pastore I, Marra P, Perani L, Esposito A, De Cobelli F, Carcano G, Fontana F, Fiorina P, Venturini M. Imaging in experimental models of diabetes. Acta Diabetol 2022; 59:147-161. [PMID: 34779949 DOI: 10.1007/s00592-021-01826-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/30/2021] [Indexed: 12/01/2022]
Abstract
Translational medicine, experimental medicine and experimental animal models, in particular mice and rats, represent a multidisciplinary field that has made it possible to achieve, in the last decades, important scientific progress. In this review, we have summarized the most frequently used imaging animal models, such as ultrasound (US), micro-CT, MRI and the optical imaging methods, and their main implications in diagnostic and therapeutic fields, with a particular focus on diabetes mellitus, a multifactorial disease extremely widespread among the general population.
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Affiliation(s)
- Andrea Coppola
- Diagnostic and Interventional Radiology Unit, ASST Settelaghi, Varese, Italy.
| | | | - Filippo Piacentino
- Diagnostic and Interventional Radiology Unit, ASST Settelaghi, Varese, Italy
- Insubria University, Varese, Italy
| | - Valeria Bettoni
- Diagnostic and Interventional Radiology Unit, ASST Settelaghi, Varese, Italy
| | - Ida Pastore
- Division of Endocrinology, ASST Fatebenefratelli-Sacco, Milan, Italy
| | - Paolo Marra
- Department of Diagnostic Radiology, Giovanni XXIII Hospital, Milano-Bicocca University, Bergamo, Italy
| | - Laura Perani
- Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
| | - Antonio Esposito
- Experimental Imaging Center, San Raffaele Scientific Institute, Milan, Italy
- Radiology Unit, San Raffaele Scientific Institute, San Raffaele Vita-Salute University, Milan, Italy
| | - Francesco De Cobelli
- Radiology Unit, San Raffaele Scientific Institute, San Raffaele Vita-Salute University, Milan, Italy
| | - Giulio Carcano
- Insubria University, Varese, Italy
- General, Emergency, and Transplant Surgery Unit, ASST Settelaghi, Varese, Italy
| | - Federico Fontana
- Diagnostic and Interventional Radiology Unit, ASST Settelaghi, Varese, Italy
- Insubria University, Varese, Italy
| | - Paolo Fiorina
- International Center for T1D, Centro di Ricerca Pediatrica Romeo ed Enrica Invernizzi, Dipartimento di Scienze Biomediche e Cliniche "L. Sacco", Università di Milano, Milan, Italy
- Nephrology Division, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Endocrinology Division, ASST Fatebenefratelli Sacco, Milan, Italy
| | - Massimo Venturini
- Diagnostic and Interventional Radiology Unit, ASST Settelaghi, Varese, Italy
- Insubria University, Varese, Italy
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8
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Abstract
β-Cells in the islet of Langerhans have a central role in maintaining energy homeostasis. Understanding the physiology of β-cells and other islet cells requires a deep understanding of their structural and functional organization, their interaction with vessels and nerves, the layout of paracrine interactions, and the relationship between subcellular compartments and protein complexes inside each cell. These elements are not static; they are dynamic and exert their biological actions at different scales of time. Therefore, scientists must be able to investigate (and visualize) short- and long-lived events within the pancreas and β-cells. Current technological advances in microscopy are able to bridge multiple spatiotemporal scales in biology to reveal the complexity and heterogeneity of β-cell biology. Here, I briefly discuss the historical discoveries that leveraged microscopes to establish the basis of β-cell anatomy and structure, the current imaging platforms that allow the study of islet and β-cell biology at multiple scales of resolution, and their challenges and implications. Lastly, I outline how the remarkable longevity of structural elements at different scales in biology, from molecules to cells to multicellular structures, could represent a previously unrecognized organizational pattern in developing and adult β-cells and pancreas biology.
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Affiliation(s)
- Rafael Arrojo E Drigo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
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9
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Bauchle CJ, Rohli KE, Boyer CK, Pal V, Rocheleau JV, Liu S, Imai Y, Taylor EB, Stephens SB. Mitochondrial Efflux of Citrate and Isocitrate Is Fully Dispensable for Glucose-Stimulated Insulin Secretion and Pancreatic Islet β-Cell Function. Diabetes 2021; 70:1717-1728. [PMID: 34039628 PMCID: PMC8385611 DOI: 10.2337/db21-0037] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/22/2021] [Indexed: 11/13/2022]
Abstract
The defining feature of pancreatic islet β-cell function is the precise coordination of changes in blood glucose levels with insulin secretion to regulate systemic glucose homeostasis. While ATP has long been heralded as a critical metabolic coupling factor to trigger insulin release, glucose-derived metabolites have been suggested to further amplify fuel-stimulated insulin secretion. The mitochondrial export of citrate and isocitrate through the citrate-isocitrate carrier (CIC) has been suggested to initiate a key pathway that amplifies glucose-stimulated insulin secretion, though the physiological significance of β-cell CIC-to-glucose homeostasis has not been established. Here, we generated constitutive and adult CIC β-cell knockout (KO) mice and demonstrate that these animals have normal glucose tolerance, similar responses to diet-induced obesity, and identical insulin secretion responses to various fuel secretagogues. Glucose-stimulated NADPH production was impaired in β-cell CIC KO islets, whereas glutathione reduction was retained. Furthermore, suppression of the downstream enzyme cytosolic isocitrate dehydrogenase (Idh1) inhibited insulin secretion in wild-type islets but failed to impact β-cell function in β-cell CIC KO islets. Our data demonstrate that the mitochondrial CIC is not required for glucose-stimulated insulin secretion and that additional complexities exist for the role of Idh1 and NADPH in the regulation of β-cell function.
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Affiliation(s)
- Casey J Bauchle
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA
| | - Kristen E Rohli
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA
| | - Cierra K Boyer
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Department of Pharmacology, University of Iowa, Iowa City, IA
| | - Vidhant Pal
- Institute of Biomedical Engineering, Toronto, Ontario, Canada
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Jonathan V Rocheleau
- Institute of Biomedical Engineering, Toronto, Ontario, Canada
- Toronto General Hospital Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Siming Liu
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA
| | - Yumi Imai
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA
- Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA
- Iowa City Veterans Affairs Medical Center, Iowa City, IA
| | - Eric B Taylor
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA
| | - Samuel B Stephens
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Iowa, Iowa City, IA
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA
- Pappajohn Biomedical Institute, University of Iowa, Iowa City, IA
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10
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Adams MT, Dwulet JM, Briggs JK, Reissaus CA, Jin E, Szulczewski JM, Lyman MR, Sdao SM, Kravets V, Nimkulrat SD, Ponik SM, Merrins MJ, Mirmira RG, Linnemann AK, Benninger RKP, Blum B. Reduced synchroneity of intra-islet Ca 2+ oscillations in vivo in Robo-deficient β cells. eLife 2021; 10:e61308. [PMID: 34231467 PMCID: PMC8289414 DOI: 10.7554/elife.61308] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 07/06/2021] [Indexed: 12/13/2022] Open
Abstract
The spatial architecture of the islets of Langerhans is hypothesized to facilitate synchronized insulin secretion among β cells, yet testing this in vivo in the intact pancreas is challenging. Robo βKO mice, in which the genes Robo1 and Robo2 are deleted selectively in β cells, provide a unique model of altered islet spatial architecture without loss of β cell differentiation or islet damage from diabetes. Combining Robo βKO mice with intravital microscopy, we show here that Robo βKO islets have reduced synchronized intra-islet Ca2+ oscillations among β cells in vivo. We provide evidence that this loss is not due to a β cell-intrinsic function of Robo, mis-expression or mis-localization of Cx36 gap junctions, or changes in islet vascularization or innervation, suggesting that the islet architecture itself is required for synchronized Ca2+ oscillations. These results have implications for understanding structure-function relationships in the islets during progression to diabetes as well as engineering islets from stem cells.
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Affiliation(s)
- Melissa T Adams
- Department of Cell and Regenerative Biology, University of Wisconsin-MadisonMadisonUnited States
| | - JaeAnn M Dwulet
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical CampusAuroraUnited States
| | - Jennifer K Briggs
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical CampusAuroraUnited States
| | - Christopher A Reissaus
- Herman B Wells Center for Pediatric Research and Center for Diabetes and Metabolic Diseases, Indiana University School of MedicineIndianapolisUnited States
| | - Erli Jin
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-MadisonMadisonUnited States
| | - Joseph M Szulczewski
- Department of Cell and Regenerative Biology, University of Wisconsin-MadisonMadisonUnited States
| | - Melissa R Lyman
- Department of Cell and Regenerative Biology, University of Wisconsin-MadisonMadisonUnited States
| | - Sophia M Sdao
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-MadisonMadisonUnited States
| | - Vira Kravets
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical CampusAuroraUnited States
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Sutichot D Nimkulrat
- Department of Cell and Regenerative Biology, University of Wisconsin-MadisonMadisonUnited States
| | - Suzanne M Ponik
- Department of Cell and Regenerative Biology, University of Wisconsin-MadisonMadisonUnited States
| | - Matthew J Merrins
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin-MadisonMadisonUnited States
| | - Raghavendra G Mirmira
- Kovler Diabetes Center and the Department of Medicine, University of ChicagoChicagoUnited States
| | - Amelia K Linnemann
- Herman B Wells Center for Pediatric Research and Center for Diabetes and Metabolic Diseases, Indiana University School of MedicineIndianapolisUnited States
| | - Richard KP Benninger
- Department of Bioengineering, University of Colorado Denver, Anschutz Medical CampusAuroraUnited States
- Barbara Davis Center for Diabetes, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Barak Blum
- Department of Cell and Regenerative Biology, University of Wisconsin-MadisonMadisonUnited States
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11
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de Boer P, Giepmans BN. State-of-the-art microscopy to understand islets of Langerhans: what to expect next? Immunol Cell Biol 2021; 99:509-520. [PMID: 33667022 PMCID: PMC8252556 DOI: 10.1111/imcb.12450] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 12/12/2022]
Abstract
The discovery of Langerhans and microscopic description of islets in the pancreas were crucial steps in the discovery of insulin. Over the past 150 years, many discoveries in islet biology and type 1 diabetes have been made using powerful microscopic techniques. In the past decade, combination of new probes, animal and tissue models, application of new biosensors and automation of light and electron microscopic methods and other (sub)cellular imaging modalities have proven their potential in understanding the beta cell under (patho)physiological conditions. The imaging evolution, from fluorescent jellyfish to real‐time intravital functional imaging, the revolution in automation and data handling and the increased resolving power of analytical imaging techniques are now converging. Here, we review innovative approaches that address islet biology from new angles by studying cells and molecules at high spatiotemporal resolution and in live models. Broad implementation of these cellular imaging techniques will shed new light on cause/consequence of (mal)function in islets of Langerhans in the years to come.
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Affiliation(s)
- Pascal de Boer
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ben Ng Giepmans
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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12
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Dybala MP, Hara M. In Vivo and In Situ Approach to Study Islet Microcirculation: A Mini-Review. Front Endocrinol (Lausanne) 2021; 12:602620. [PMID: 34040578 PMCID: PMC8142941 DOI: 10.3389/fendo.2021.602620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 04/26/2021] [Indexed: 11/28/2022] Open
Abstract
The pancreas is regarded as consisting of two separate organ systems, the endocrine and exocrine pancreas. While treatment of a disease with either an endocrine or exocrine pathogenesis may affect the function of the entire pancreas, the pancreatic diseases have been treated by clinicians in different medical disciplines, including endocrinologists and gastroenterologists. Islet microcirculation has long been considered to be regulated independently from that of the exocrine pancreas. A new model proposes that pancreatic islet blood flow is integrated with the surrounding exocrine capillary network. This recent model may provide revived or contrasting hypotheses to test, since the pancreatic microcirculation has critical implications for the regulation of islet hormones as well as acinar pancreas functions. In this mini-review, practical applications of in vivo and in situ studies of islet microcirculation are described with a specific emphasis on large-scale data analysis to ensure sufficient sample size accounting for known islet heterogeneity. For in vivo small animal studies, intravital microscopy based on two-photon excitation microscopes is a powerful tool that enables capturing the flow direction and speed of individual fluorescent-labeled red blood cells. Complementarily, for structural analysis of blood vessels, the recent technical advancements of confocal microscopy and tissue clearing have enabled us to image the three-dimensional network structure in thick tissue slices.
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Affiliation(s)
| | - Manami Hara
- Department of Medicine, The University of Chicago, Chicago, IL, United States
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13
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Muralidharan C, Conteh AM, Marasco MR, Crowder JJ, Kuipers J, de Boer P, Linnemann AK. Pancreatic beta cell autophagy is impaired in type 1 diabetes. Diabetologia 2021; 64:865-877. [PMID: 33515072 PMCID: PMC7940272 DOI: 10.1007/s00125-021-05387-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/01/2020] [Indexed: 12/19/2022]
Abstract
AIMS/HYPOTHESIS Pancreatic beta cells are subjected to exogenous damaging factors such as proinflammatory cytokines or excess glucose that can cause accumulation of damage-inducing reactive oxygen species during the pathogenesis of diabetes. We and others have shown that beta cell autophagy can reduce reactive oxygen species to protect against apoptosis. While impaired islet autophagy has been demonstrated in human type 2 diabetes, it is unknown if islet autophagy is perturbed in the pathogenesis of type 1 diabetes. We hypothesised that beta cell autophagy is dysfunctional in type 1 diabetes, and that there is a progressive loss during early diabetes development. METHODS Pancreases were collected from chloroquine-injected and non-injected non-obese diabetes-resistant (NOR) and non-obese diabetic (NOD) mice. Age- and BMI-matched pancreas tissue sections from human organ donors (N = 34) were obtained from the Network for Pancreatic Organ Donors with Diabetes (nPOD). Tissue sections were stained with antibodies against proinsulin or insulin (beta cell markers), microtubule-associated protein 1 light chain 3 A/B (LC3A/B; autophagosome marker), lysosomal-associated membrane protein 1 (LAMP1; lysosome marker) and p62 (autophagy adaptor). Images collected on a scanning laser confocal microscope were analysed with CellProfiler and ImageJ. Secondary lysosomes and telolysosomes were assessed in electron micrographs of human pancreatic tissue sections (n = 12), and energy dispersive x-ray analysis was performed to assess distribution of elements (n = 5). RESULTS We observed increased autophagosome numbers in islets of diabetic NOD mice (p = 0.008) and increased p62 in islets of both non-diabetic and diabetic NOD mice (p < 0.001) vs NOR mice. There was also a reduction in LC3-LAMP1 colocalisation in islets of diabetic NOD mice compared with both non-diabetic NOD (p < 0.001) and NOR mice (p < 0.001). Chloroquine elicited accumulation of autophagosomes in the islets of NOR (p = 0.003) and non-diabetic NOD mice (p < 0.001), but not in islets of diabetic NOD mice; and stimulated accumulation of p62 in NOR (p < 0.001), but not in NOD mice. We observed reduced LC3-LAMP1 colocalisation (p < 0.001) in residual beta cells of human donors with type 1 diabetes vs non-diabetic participants. We also observed reduced colocalisation of proinsulin with LAMP1 in donors with type 1 diabetes (p < 0.001). Electron microscopy also revealed accumulation of telolysosomes with nitrogen-dense rings in beta cells of autoantibody-positive donors (p = 0.002). CONCLUSIONS/INTERPRETATION We provide evidence of islet macroautophagy/crinophagy impairment in human type 1 diabetes. We also document accumulation of telolysosomes with peripheral nitrogen in beta cells of autoantibody-positive donors, demonstrating altered lysosome content that may be associated with lysosome dysfunction before clinical hyperglycaemia. Similar macroautophagy impairments are present in the NOD mouse model of type 1 diabetes.
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Affiliation(s)
- Charanya Muralidharan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Abass M Conteh
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Michelle R Marasco
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Justin J Crowder
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jeroen Kuipers
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Pascal de Boer
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Amelia K Linnemann
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA.
- Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA.
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14
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Huang Q, Garrett A, Bose S, Blocker S, Rios AC, Clevers H, Shen X. The frontier of live tissue imaging across space and time. Cell Stem Cell 2021; 28:603-622. [PMID: 33798422 PMCID: PMC8034393 DOI: 10.1016/j.stem.2021.02.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
What you see is what you get-imaging techniques have long been essential for visualization and understanding of tissue development, homeostasis, and regeneration, which are driven by stem cell self-renewal and differentiation. Advances in molecular and tissue modeling techniques in the last decade are providing new imaging modalities to explore tissue heterogeneity and plasticity. Here we describe current state-of-the-art imaging modalities for tissue research at multiple scales, with a focus on explaining key tradeoffs such as spatial resolution, penetration depth, capture time/frequency, and moieties. We explore emerging tissue modeling and molecular tools that improve resolution, specificity, and throughput.
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Affiliation(s)
- Qiang Huang
- Department of Pediatric Surgery, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710004 Shaanxi, China; Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Aliesha Garrett
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Shree Bose
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA
| | - Stephanie Blocker
- Center for In Vitro Microscopy, Duke University, Durham, NC 27708, USA
| | - Anne C Rios
- Princess Máxima Center for Pediatric Oncology, Utrecht 3584, the Netherlands; Department of Cancer Research, Oncode Institute, Hubrecht Institute-KNAW Utrecht, Utrecht 3584, the Netherlands
| | - Hans Clevers
- Princess Máxima Center for Pediatric Oncology, Utrecht 3584, the Netherlands; Department of Cancer Research, Oncode Institute, Hubrecht Institute-KNAW Utrecht, Utrecht 3584, the Netherlands; Hubrecht Institute, Royal Netherlands Academy of Arts and Sciences (KNAW) and University Medical Center (UMC) Utrecht, Utrecht 3584, the Netherlands
| | - Xiling Shen
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC 27708, USA.
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15
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Dunn KW, Molitoris BA, Dagher PC. The Indiana O'Brien Center for Advanced Renal Microscopic Analysis. Am J Physiol Renal Physiol 2021; 320:F671-F682. [PMID: 33682441 DOI: 10.1152/ajprenal.00007.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Indiana O'Brien Center for Advanced Microscopic Analysis is a National Institutes of Health (NIH) P30-funded research center dedicated to the development and dissemination of advanced methods of optical microscopy to support renal researchers throughout the world. The Indiana O'Brien Center was founded in 2002 as an NIH P-50 project with the original goal of helping researchers realize the potential of intravital multiphoton microscopy as a tool for understanding renal physiology and pathophysiology. The center has since expanded into the development and implementation of large-scale, high-content tissue cytometry. The advanced imaging capabilities of the center are made available to renal researchers worldwide via collaborations and a unique fellowship program. Center outreach is accomplished through an enrichment core that oversees a seminar series, an informational website, and a biennial workshop featuring hands-on training from members of the Indiana O'Brien Center and imaging experts from around the world.
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Affiliation(s)
- Kenneth W Dunn
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Bruce A Molitoris
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
| | - Pierre C Dagher
- Division of Nephrology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana
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16
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Makhmutova M, Weitz J, Tamayo A, Pereira E, Boulina M, Almaça J, Rodriguez-Diaz R, Caicedo A. Pancreatic β-Cells Communicate With Vagal Sensory Neurons. Gastroenterology 2021; 160:875-888.e11. [PMID: 33121946 PMCID: PMC10009739 DOI: 10.1053/j.gastro.2020.10.034] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 10/17/2020] [Accepted: 10/20/2020] [Indexed: 12/23/2022]
Abstract
BACKGROUND AND AIMS Destroying visceral sensory nerves impacts pancreatic islet function, glucose metabolism, and diabetes onset, but how islet endocrine cells interact with sensory neurons has not been studied. METHODS We characterized the anatomical pattern of pancreatic sensory innervation by combining viral tracing, immunohistochemistry, and reporter mouse models. To assess the functional interactions of β-cells with vagal sensory neurons, we recorded Ca2+ responses in individual nodose neurons in vivo while selectively stimulating β-cells with chemogenetic and pharmacologic approaches. RESULTS We found that pancreatic islets are innervated by vagal sensory axons expressing Phox2b, substance P, calcitonin-gene related peptide, and the serotonin receptor 5-HT3R. Centrally, vagal neurons projecting to the pancreas terminate in the commissural nucleus of the solitary tract. Nodose neurons responded in vivo to chemogenetic stimulation of β-cells and to pancreas infusion with serotonin, but were not sensitive to insulin. Responses to chemogenetic and pharmacologic stimulation of β-cells were blocked by a 5-HT3R antagonist and were enhanced by increasing serotonin levels in β-cells. We further confirmed directly in living pancreas slices that sensory terminals in the islet were sensitive to serotonin. CONCLUSIONS Our study establishes that pancreatic β-cells communicate with vagal sensory neurons, likely using serotonin signaling as a transduction mechanism. Serotonin is coreleased with insulin and may therefore convey information about the secretory state of β-cells via vagal afferent nerves.
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Affiliation(s)
- Madina Makhmutova
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida; Program in Neuroscience, Miller School of Medicine, University of Miami, Miami, Florida.
| | - Jonathan Weitz
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
| | - Alejandro Tamayo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
| | - Elizabeth Pereira
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida; Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida
| | - Maria Boulina
- Analytical Imaging Core Facility, Miller School of Medicine, University of Miami
| | - Joana Almaça
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
| | - Rayner Rodriguez-Diaz
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida; Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, Florida
| | - Alejandro Caicedo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida; Program in Neuroscience, Miller School of Medicine, University of Miami, Miami, Florida; Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida; Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, Florida.
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17
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Frikke-Schmidt H, Arvan P, Seeley RJ, Cras-Méneur C. Improved in vivo imaging method for individual islets across the mouse pancreas reveals a heterogeneous insulin secretion response to glucose. Sci Rep 2021; 11:603. [PMID: 33436691 PMCID: PMC7804140 DOI: 10.1038/s41598-020-79727-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 12/08/2020] [Indexed: 12/19/2022] Open
Abstract
While numerous techniques can be used to measure and analyze insulin secretion in isolated islets in culture, assessments of insulin secretion in vivo are typically indirect and only semiquantitative. The CpepSfGFP reporter mouse line allows the in vivo imaging of insulin secretion from individual islets after a glucose stimulation, in live, anesthetized mice. Imaging the whole pancreas at high resolution in live mice to track the response of each individual islet over time includes numerous technical challenges and previous reports were only limited in scope and non-quantitative. Elaborating on this previous model-through the development of an improved methodology addressing anesthesia, temperature control and motion blur-we were able to track and quantify longitudinally insulin content throughout a glucose challenge in up to two hundred individual islets simultaneously. Through this approach we demonstrate quantitatively for the first time that while isolated islets respond homogeneously to glucose in culture, their profiles differ significantly in vivo. Independent of size or location, some islets respond sharply to a glucose stimulation while others barely secrete at all. This platform therefore provides a powerful approach to study the impact of disease, diet, surgery or pharmacological treatments on insulin secretion in the intact pancreas in vivo.
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Affiliation(s)
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, 2800 Plymouth Rd, Ann Arbor, MI, 48109, USA
| | - Randy J Seeley
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, 2800 Plymouth Rd, Ann Arbor, MI, 48109, USA
| | - Corentin Cras-Méneur
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan, 2800 Plymouth Rd, Ann Arbor, MI, 48109, USA.
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18
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Chen S, Huang Z, Kidd H, Kim M, Suh EH, Xie S, Ghazvini Zadeh EH, Xu Y, Sherry AD, Scherer PE, Li WH. In Vivo ZIMIR Imaging of Mouse Pancreatic Islet Cells Shows Oscillatory Insulin Secretion. Front Endocrinol (Lausanne) 2021; 12:613964. [PMID: 33767668 PMCID: PMC7985533 DOI: 10.3389/fendo.2021.613964] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 01/26/2021] [Indexed: 01/11/2023] Open
Abstract
Appropriate insulin secretion is essential for maintaining euglycemia, and impairment or loss of insulin release represents a causal event leading to diabetes. There have been extensive efforts of studying insulin secretion and its regulation using a variety of biological preparations, yet it remains challenging to monitor the dynamics of insulin secretion at the cellular level in the intact pancreas of living animals, where islet cells are supplied with physiological blood circulation and oxygenation, nerve innervation, and tissue support of surrounding exocrine cells. Herein we presented our pilot efforts of ZIMIR imaging in pancreatic islet cells in a living mouse. The imaging tracked insulin/Zn2+ release of individual islet β-cells in the intact pancreas with high spatiotemporal resolution, revealing a rhythmic secretion activity that appeared to be synchronized among islet β-cells. To facilitate probe delivery to islet cells, we also developed a chemogenetic approach by expressing the HaloTag protein on the cell surface. Finally, we demonstrated the application of a fluorescent granule zinc indicator, ZIGIR, as a selective and efficient islet cell marker in living animals through systemic delivery. We expect future optimization and integration of these approaches would enable longitudinal tracking of beta cell mass and function in vivo by optical imaging.
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Affiliation(s)
- Shiuhwei Chen
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical, Dallas, TX, United States
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - ZhiJiang Huang
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical, Dallas, TX, United States
| | - Harrison Kidd
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical, Dallas, TX, United States
| | - Min Kim
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Biological Sciences, School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Eul Hyun Suh
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Shangkui Xie
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical, Dallas, TX, United States
| | - Ebrahim H. Ghazvini Zadeh
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical, Dallas, TX, United States
| | - Yan Xu
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical, Dallas, TX, United States
| | - A. Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Chemistry and Biochemistry, University of Texas Dallas, Richardson, TX, United States
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Philipp E. Scherer
- Touchstone Diabetes Center, University of Texas Southwestern Medical Center, Dallas, TX, United States
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Wen-hong Li
- Departments of Cell Biology and of Biochemistry, University of Texas Southwestern Medical, Dallas, TX, United States
- *Correspondence: Wen-hong Li,
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19
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Abstract
At the time of Ivan Pavlov, pancreatic innervation was studied by looking at pancreas secretions in response to electrical stimulation of nerves. Nowadays we have ways to visualize neuronal activity in real time thanks to advances in fluorescent reporters and imaging techniques. We also have very precise optogenetic and pharmacogenetic approaches that allow neuronal manipulations in a very specific manner. These technological advances have been extensively employed for studying the central nervous system and are just beginning to be incorporated for studying visceral innervation. Pancreatic innervation is complex, and the role it plays in physiology and pathophysiology of the organ is still not fully understood. In this review we highlight anatomical aspects of pancreatic innervation, techniques for pancreatic neuronal labeling, and approaches for imaging pancreatic innervation in vitro and in vivo.
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20
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Kostyuk AI, Panova AS, Kokova AD, Kotova DA, Maltsev DI, Podgorny OV, Belousov VV, Bilan DS. In Vivo Imaging with Genetically Encoded Redox Biosensors. Int J Mol Sci 2020; 21:E8164. [PMID: 33142884 PMCID: PMC7662651 DOI: 10.3390/ijms21218164] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 10/28/2020] [Accepted: 10/29/2020] [Indexed: 12/13/2022] Open
Abstract
Redox reactions are of high fundamental and practical interest since they are involved in both normal physiology and the pathogenesis of various diseases. However, this area of research has always been a relatively problematic field in the context of analytical approaches, mostly because of the unstable nature of the compounds that are measured. Genetically encoded sensors allow for the registration of highly reactive molecules in real-time mode and, therefore, they began a new era in redox biology. Their strongest points manifest most brightly in in vivo experiments and pave the way for the non-invasive investigation of biochemical pathways that proceed in organisms from different systematic groups. In the first part of the review, we briefly describe the redox sensors that were used in vivo as well as summarize the model systems to which they were applied. Next, we thoroughly discuss the biological results obtained in these studies in regard to animals, plants, as well as unicellular eukaryotes and prokaryotes. We hope that this work reflects the amazing power of this technology and can serve as a useful guide for biologists and chemists who work in the field of redox processes.
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Affiliation(s)
- Alexander I. Kostyuk
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Anastasiya S. Panova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Aleksandra D. Kokova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Daria A. Kotova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Dmitry I. Maltsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
| | - Oleg V. Podgorny
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Vsevolod V. Belousov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Federal Center for Cerebrovascular Pathology and Stroke, 117997 Moscow, Russia
- Institute for Cardiovascular Physiology, Georg August University Göttingen, D-37073 Göttingen, Germany
| | - Dmitry S. Bilan
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, 117997 Moscow, Russia; (A.I.K.); (A.S.P.); (A.D.K.); (D.A.K.); (D.I.M.); (O.V.P.); (V.V.B.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
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Huey J, Keutler K, Schultz C. Chemical Biology Toolbox for Studying Pancreatic Islet Function - A Perspective. Cell Chem Biol 2020; 27:1015-1031. [PMID: 32822616 DOI: 10.1016/j.chembiol.2020.07.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 07/10/2020] [Accepted: 07/28/2020] [Indexed: 01/14/2023]
Abstract
The islets of Langerhans represent one of the many complex endocrine organs in mammals. Traditionally, islet function is studied by a mixture of physiological, cell biological, and molecular biological methods. Recently, novel techniques stemming from the ever-increasing toolbox provided by chemical laboratories have been added to the repertoire. Many emerging techniques will soon be available to manipulate and monitor islet function at the single-cell level and potentially in intact model animals, as well as in isolated human islets. Here, we review the most current small-molecule-based and genetically encoded molecular tool sets available to study islet function. We provide an outlook regarding future tool developments that will impact islet research, with a special focus on the interplay between different islet cell types.
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Affiliation(s)
- Julia Huey
- Program in Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97210, USA; Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97210, USA
| | - Kaya Keutler
- Program in Physiology and Pharmacology, Oregon Health and Science University, Portland, OR 97210, USA; Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97210, USA
| | - Carsten Schultz
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR 97210, USA.
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22
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Reissaus CA, Day KH, Mirmira RG, Dunn KW, Pavalko FM, Day RN. PIE-FLIM Measurements of Two Different FRET-Based Biosensor Activities in the Same Living Cells. Biophys J 2020; 118:1820-1829. [PMID: 32191861 DOI: 10.1016/j.bpj.2020.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 02/27/2020] [Accepted: 03/02/2020] [Indexed: 12/14/2022] Open
Abstract
We report the use of pulsed interleaved excitation (PIE)-fluorescence lifetime imaging microscopy (FLIM) to measure the activities of two different biosensor probes simultaneously in single living cells. Many genetically encoded biosensors rely on the measurement of Förster resonance energy transfer (FRET) to detect changes in biosensor conformation that accompany the targeted cell signaling event. One of the most robust ways of quantifying FRET is to measure changes in the fluorescence lifetime of the donor fluorophore using FLIM. The study of complex signaling networks in living cells demands the ability to track more than one of these cellular events at the same time. Here, we demonstrate how PIE-FLIM can separate and quantify the signals from different FRET-based biosensors to simultaneously measure changes in the activity of two cell signaling pathways in the same living cells in tissues. The imaging system described here uses selectable laser wavelengths and synchronized detection gating that can be tailored and optimized for each FRET pair. Proof-of-principle studies showing simultaneous measurement of cytosolic calcium and protein kinase A activity are shown, but the PIE-FLIM approach is broadly applicable to other signaling pathways.
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Affiliation(s)
- Christopher A Reissaus
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana; The Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kathleen H Day
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Raghavendra G Mirmira
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana; The Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kenneth W Dunn
- The Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana; Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Fredrick M Pavalko
- Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, Indiana; The Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, Indiana
| | - Richard N Day
- The Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, Indiana; Department of Anatomy, Cell Biology & Physiology, Indiana University School of Medicine, Indianapolis, Indiana.
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23
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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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24
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Roma LP, Jonas JC. Nutrient Metabolism, Subcellular Redox State, and Oxidative Stress in Pancreatic Islets and β-Cells. J Mol Biol 2019; 432:1461-1493. [PMID: 31634466 DOI: 10.1016/j.jmb.2019.10.012] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/25/2019] [Accepted: 10/10/2019] [Indexed: 01/01/2023]
Abstract
Insulin-secreting pancreatic β-cells play a critical role in blood glucose homeostasis and the development of type 2 diabetes (T2D) in the context of insulin resistance. Based on data obtained at the whole cell level using poorly specific chemical probes, reactive oxygen species (ROS) such as superoxide and hydrogen peroxide have been proposed to contribute to the stimulation of insulin secretion by nutrients (positive role) and to the alterations of cell survival and secretory function in T2D (negative role). This raised the controversial hypothesis that any attempt to decrease β-cell oxidative stress and apoptosis in T2D would further impair insulin secretion. Over the last decade, the development of genetically-encoded redox probes that can be targeted to cellular compartments of interest and are specific of redox couples allowed the evaluation of short- and long-term effects of nutrients on β-cell redox changes at the subcellular level. The data indicated that the nutrient regulation of β-cell redox signaling and ROS toxicity is far more complex than previously thought and that the subcellular compartmentation of these processes cannot be neglected when evaluating the mechanisms of ROS production or the efficacy of antioxidant enzymes and antioxidant drugs under glucolipotoxic conditions and in T2D. In this review, we present what is currently known about the compartmentation of redox homeostatic systems and tools to investigate it. We then review data about the effects of nutrients on β-cell subcellular redox state under normal conditions and in the context of T2D and discuss challenges and opportunities in the field.
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Affiliation(s)
- Leticia P Roma
- Universität des Saarlandes, Biophysics Department, Center for Human and Molecular Biology, Kirbergerstrasse Building 48, 66421, Homburg/Saar, Germany
| | - Jean-Christophe Jonas
- Université Catholique de Louvain, Institute of Experimental and Clinical Research, Pole of Endocrinology, Diabetes and Nutrition, Avenue Hippocrate 55 (B1.55.06), B-1200 Brussels, Belgium.
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