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Hill TG, Hill DJ. The Importance of Intra-Islet Communication in the Function and Plasticity of the Islets of Langerhans during Health and Diabetes. Int J Mol Sci 2024; 25:4070. [PMID: 38612880 PMCID: PMC11012451 DOI: 10.3390/ijms25074070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 03/27/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Islets of Langerhans are anatomically dispersed within the pancreas and exhibit regulatory coordination between islets in response to nutritional and inflammatory stimuli. However, within individual islets, there is also multi-faceted coordination of function between individual beta-cells, and between beta-cells and other endocrine and vascular cell types. This is mediated partly through circulatory feedback of the major secreted hormones, insulin and glucagon, but also by autocrine and paracrine actions within the islet by a range of other secreted products, including somatostatin, urocortin 3, serotonin, glucagon-like peptide-1, acetylcholine, and ghrelin. Their availability can be modulated within the islet by pericyte-mediated regulation of microvascular blood flow. Within the islet, both endocrine progenitor cells and the ability of endocrine cells to trans-differentiate between phenotypes can alter endocrine cell mass to adapt to changed metabolic circumstances, regulated by the within-islet trophic environment. Optimal islet function is precariously balanced due to the high metabolic rate required by beta-cells to synthesize and secrete insulin, and they are susceptible to oxidative and endoplasmic reticular stress in the face of high metabolic demand. Resulting changes in paracrine dynamics within the islets can contribute to the emergence of Types 1, 2 and gestational diabetes.
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Affiliation(s)
- Thomas G. Hill
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - David J. Hill
- Lawson Health Research Institute, St. Joseph’s Health Care, London, ON N6A 4V2, Canada;
- Departments of Medicine, Physiology and Pharmacology, Western University, London, ON N6A 3K7, Canada
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Slak Rupnik M, Hara M. Local Dialogues Between the Endocrine and Exocrine Cells in the Pancreas. Diabetes 2024; 73:533-541. [PMID: 38215069 PMCID: PMC10958587 DOI: 10.2337/db23-0760] [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: 09/20/2023] [Accepted: 01/03/2024] [Indexed: 01/14/2024]
Abstract
For many years, it has been taught in medical textbooks that the endocrine and exocrine parts of the pancreas have separate blood supplies that do not mix. Therefore, they have been studied by different scientific communities, and patients with pancreatic disorders are treated by physicians in different medical disciplines, where endocrine and exocrine function are the focus of endocrinologists and gastroenterologists, respectively. The conventional model that every islet in each pancreatic lobule receives a dedicated arterial blood supply was first proposed in 1932, and it has been inherited to date. Recently, in vivo intravital recording of red blood cell flow in mouse islets as well as in situ structural analysis of 3D pancreatic vasculature from hundreds of islets provided evidence for preferentially integrated pancreatic blood flow in six mammalian species. The majority of islets have no association with the arteriole, and there is bidirectional blood exchange between the two segments. Such vascularization may allow an entire downstream region of islets and acinar cells to be simultaneously exposed to a topologically and temporally specific plasma content, which could underlie an adaptive sensory function as well as common pathogeneses of both portions of the organ in pancreatic diseases, including diabetes. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Marjan Slak Rupnik
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Manami Hara
- Department of Medicine, The University of Chicago, Chicago, IL
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Mateus Gonçalves L, Andrade Barboza C, Almaça J. Diabetes as a Pancreatic Microvascular Disease-A Pericytic Perspective. J Histochem Cytochem 2024; 72:131-148. [PMID: 38454609 PMCID: PMC10956440 DOI: 10.1369/00221554241236535] [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: 11/28/2023] [Accepted: 02/09/2024] [Indexed: 03/09/2024] Open
Abstract
Diabetes is not only an endocrine but also a vascular disease. Vascular defects are usually seen as consequence of diabetes. However, at the level of the pancreatic islet, vascular alterations have been described before symptom onset. Importantly, the cellular and molecular mechanisms underlying these early vascular defects have not been identified, neither how these could impact the function of islet endocrine cells. In this review, we will discuss the possibility that dysfunction of the mural cells of the microvasculature-known as pericytes-underlies vascular defects observed in islets in pre-symptomatic stages. Pericytes are crucial for vascular homeostasis throughout the body, but their physiological and pathophysiological functions in islets have only recently started to be explored. A previous study had already raised interest in the "microvascular" approach to this disease. With our increased understanding of the crucial role of the islet microvasculature for glucose homeostasis, here we will revisit the vascular aspects of islet function and how their deregulation could contribute to diabetes pathogenesis, focusing in particular on type 1 diabetes (T1D).
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Affiliation(s)
- Luciana Mateus Gonçalves
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
| | - Catarina Andrade Barboza
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
| | - Joana Almaça
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, Florida
- Molecular and Cellular Pharmacology Graduate Program, University of Miami Miller School of Medicine, Miami, Florida
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, Florida
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Malik SS, Padmanabhan D, Hull-Meichle RL. Pancreas and islet morphology in cystic fibrosis: clues to the etiology of cystic fibrosis-related diabetes. Front Endocrinol (Lausanne) 2023; 14:1269139. [PMID: 38075070 PMCID: PMC10704027 DOI: 10.3389/fendo.2023.1269139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 10/03/2023] [Indexed: 12/18/2023] Open
Abstract
Cystic fibrosis (CF) is a multi-organ disease caused by loss-of-function mutations in CFTR (which encodes the CF transmembrane conductance regulator ion channel). Cystic fibrosis related diabetes (CFRD) occurs in 40-50% of adults with CF and is associated with significantly increased morbidity and mortality. CFRD arises from insufficient insulin release from β cells in the pancreatic islet, but the mechanisms underlying the loss of β cell function remain understudied. Widespread pathological changes in the CF pancreas provide clues to these mechanisms. The exocrine pancreas is the epicenter of pancreas pathology in CF, with ductal pathology being the initiating event. Loss of CFTR function results in ductal plugging and subsequent obliteration. This in turn leads to destruction of acinar cells, fibrosis and fatty replacement. Despite this adverse environment, islets remain relatively well preserved. However, islet composition and arrangement are abnormal, including a modest decrease in β cells and an increase in α, δ and γ cell abundance. The small amount of available data suggest that substantial loss of pancreatic/islet microvasculature, autonomic nerve fibers and intra-islet macrophages occur. Conversely, T-cell infiltration is increased and, in CFRD, islet amyloid deposition is a frequent occurrence. Together, these pathological changes clearly demonstrate that CF is a disease of the pancreas/islet microenvironment. Any or all of these changes are likely to have a dramatic effect on the β cell, which relies on positive signals from all of these neighboring cell types for its normal function and survival. A thorough characterization of the CF pancreas microenvironment is needed to develop better therapies to treat, and ultimately prevent CFRD.
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Affiliation(s)
- Sarah S. Malik
- Department of Pharmacology, University of Washington, Seattle, WA, United States
- Research Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States
| | - Diksha Padmanabhan
- Research Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States
- Seattle Institute for Biomedical and Clinical Research, Seattle, WA, United States
| | - Rebecca L. Hull-Meichle
- Department of Pharmacology, University of Washington, Seattle, WA, United States
- Research Service, Veterans Affairs Puget Sound Health Care System, Seattle, WA, United States
- Seattle Institute for Biomedical and Clinical Research, Seattle, WA, United States
- Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, University of Washington, Seattle, WA, United States
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Wirth F, Heitz FD, Seeger C, Combaluzier I, Breu K, Denroche HC, Thevenet J, Osto M, Arosio P, Kerr-Conte J, Verchere CB, Pattou F, Lutz TA, Donath MY, Hock C, Nitsch RM, Grimm J. A human antibody against pathologic IAPP aggregates protects beta cells in type 2 diabetes models. Nat Commun 2023; 14:6294. [PMID: 37813862 PMCID: PMC10562398 DOI: 10.1038/s41467-023-41986-0] [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: 01/25/2023] [Accepted: 09/26/2023] [Indexed: 10/11/2023] Open
Abstract
In patients with type 2 diabetes, pancreatic beta cells progressively degenerate and gradually lose their ability to produce insulin and regulate blood glucose. Beta cell dysfunction and loss is associated with an accumulation of aggregated forms of islet amyloid polypeptide (IAPP) consisting of soluble prefibrillar IAPP oligomers as well as insoluble IAPP fibrils in pancreatic islets. Here, we describe a human monoclonal antibody selectively targeting IAPP oligomers and neutralizing IAPP aggregate toxicity by preventing membrane disruption and apoptosis in vitro. Antibody treatment in male rats and mice transgenic for human IAPP, and human islet-engrafted mouse models of type 2 diabetes triggers clearance of IAPP oligomers resulting in beta cell protection and improved glucose control. These results provide new evidence for the pathological role of IAPP oligomers and suggest that antibody-mediated removal of IAPP oligomers could be a pharmaceutical strategy to support beta cell function in type 2 diabetes.
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Affiliation(s)
- Fabian Wirth
- Neurimmune AG, Wagistrasse 18, 8952, Schlieren, Switzerland
| | | | | | | | - Karin Breu
- Neurimmune AG, Wagistrasse 18, 8952, Schlieren, Switzerland
| | - Heather C Denroche
- BC Children's Hospital Research Institute and Centre for Molecular Medicine and Therapeutics, Departments of Surgery and Pathology & Laboratory Medicine, University of British Columbia, A4-151 950 W 28 Ave, Vancouver, BC, Canada
| | - Julien Thevenet
- Univ-Lille, Inserm, CHU Lille, U1190 - EGID, F-59000, Lille, France
| | - Melania Osto
- Institute of Veterinary Physiology, Vetsuisse Faculty of the University of Zürich, Winterthurerstrasse 260, 8057, Zürich, Switzerland
| | - Paolo Arosio
- Institute for Chemical and Bioengineering, ETH Zürich, Vladimir-Prelog-Weg 1-5/10, 8093, Zürich, Switzerland
| | - Julie Kerr-Conte
- Univ-Lille, Inserm, CHU Lille, U1190 - EGID, F-59000, Lille, France
| | - C Bruce Verchere
- BC Children's Hospital Research Institute and Centre for Molecular Medicine and Therapeutics, Departments of Surgery and Pathology & Laboratory Medicine, University of British Columbia, A4-151 950 W 28 Ave, Vancouver, BC, Canada
| | - François Pattou
- Univ-Lille, Inserm, CHU Lille, U1190 - EGID, F-59000, Lille, France
| | - Thomas A Lutz
- Institute of Veterinary Physiology, Vetsuisse Faculty of the University of Zürich, Winterthurerstrasse 260, 8057, Zürich, Switzerland
| | - Marc Y Donath
- Clinic for Endocrinology, Diabetes & Metabolism, and Department of Biomedicine, University Hospital Basel, Hebelstrasse 20, 4031, Basel, Switzerland
| | - Christoph Hock
- Neurimmune AG, Wagistrasse 18, 8952, Schlieren, Switzerland
- Institute for Regenerative Medicine-IREM, University of Zürich, Wagistrasse 12, 8952, Schlieren, Switzerland
| | - Roger M Nitsch
- Neurimmune AG, Wagistrasse 18, 8952, Schlieren, Switzerland
- Institute for Regenerative Medicine-IREM, University of Zürich, Wagistrasse 12, 8952, Schlieren, Switzerland
| | - Jan Grimm
- Neurimmune AG, Wagistrasse 18, 8952, Schlieren, Switzerland.
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Bortoletto AS, Parchem RJ. A pancreatic player in dementia: pathological role for islet amyloid polypeptide accumulation in the brain. Neural Regen Res 2023; 18:2141-2146. [PMID: 37056121 PMCID: PMC10328265 DOI: 10.4103/1673-5374.369095] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/30/2022] [Accepted: 01/19/2023] [Indexed: 02/17/2023] Open
Abstract
Type 2 diabetes mellitus patients have a markedly higher risk of developing dementia. While multiple factors contribute to this predisposition, one of these involves the increased secretion of amylin, or islet amyloid polypeptide, that accompanies the pathophysiology of type 2 diabetes mellitus. Islet amyloid polypeptide accumulation has undoubtedly been implicated in various forms of dementia, including Alzheimer's disease and vascular dementia, but the exact mechanisms underlying islet amyloid polypeptide's causative role in dementia are unclear. In this review, we have summarized the literature supporting the various mechanisms by which islet amyloid polypeptide accumulation may cause neuronal damage, ultimately leading to the clinical symptoms of dementia. We discuss the evidence for islet amyloid polypeptide deposition in the brain, islet amyloid polypeptide interaction with other amyloids implicated in neurodegeneration, neuroinflammation caused by islet amyloid polypeptide deposition, vascular damage induced by islet amyloid polypeptide accumulation, and islet amyloid polypeptide-induced cytotoxicity. There are very few therapies approved for the treatment of dementia, and of these, clinical responses have been controversial at best. Therefore, investigating new, targetable pathways is vital for identifying novel therapeutic strategies for treating dementia. As such, we conclude this review by discussing islet amyloid polypeptide accumulation as a potential therapeutic target not only in treating type 2 diabetes mellitus but as a future target in treating or even preventing dementia associated with type 2 diabetes mellitus.
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Affiliation(s)
- Angelina S. Bortoletto
- Center for Cell and Gene Therapy, Stem Cell and Regenerative Medicine Center, Department of Neuroscience, Department of Molecular and Cellular Biology, Translational Biology and Molecular Medicine Program, Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
| | - Ronald J. Parchem
- Center for Cell and Gene Therapy, Stem Cell and Regenerative Medicine Center, Department of Neuroscience, Department of Molecular and Cellular Biology, Translational Biology and Molecular Medicine Program, Medical Scientist Training Program, Baylor College of Medicine, Houston, TX, USA
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Typ-2-Diabetes: Insel-Amyloid-Polypeptid (IAPP) beeinflusst Funktion der β-Zellen. DIABETOL STOFFWECHS 2023. [DOI: 10.1055/a-1933-5970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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