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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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2
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Yang S, Cao J, Sun C, Yuan L. The Regulation Role of the Gut-Islets Axis in Diabetes. Diabetes Metab Syndr Obes 2024; 17:1415-1423. [PMID: 38533266 PMCID: PMC10964787 DOI: 10.2147/dmso.s455026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/03/2024] [Indexed: 03/28/2024] Open
Abstract
The gut-islets axis is an important endocrine signaling axis that regulates the function of islets by modulating the gut micro-environment and its endocrine metabolism. The discovery of intestinal hormones, such as GLP-1 and GIP, has established a preliminary link between the gut and the islet, paving the way for the development of GLP-1 receptor agonists based on the regulation theory of the gut-islets axis for diabetes treatment. This discovery has created a new paradigm for diabetes management and rapidly made the regulation theory of the gut-islets axis a focal point of research attention. Recent years, with in-depth study on gut microbiota and the discovery of intestinal-derived extracellular vesicles, the concept of gut endocrine and the regulation theory of the gut-islets axis have been further expanded and updated, offering tremendous research opportunities. The gut-islets axis refers to the complex interplay between the gut and the islet, which plays a crucial role in regulating glucose homeostasis and maintaining metabolic health. The axis involves various components, including gut microbiota, intestinal hormones, amino acids and ACE2, which contribute to the communication and coordination between the gut and the islet.
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Affiliation(s)
- Songtao Yang
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
| | - Jie Cao
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
| | - Chuan Sun
- Department of Emergency Medical, Wuhan ASIA GENERAL Hospital, Wuhan, 430000, People’s Republic of China
| | - Li Yuan
- Department of Endocrinology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, People’s Republic of China
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3
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Cottle L, Gilroy I, Deng K, Loudovaris T, Thomas HE, Gill AJ, Samra JS, Kebede MA, Kim J, Thorn P. Machine Learning Algorithms, Applied to Intact Islets of Langerhans, Demonstrate Significantly Enhanced Insulin Staining at the Capillary Interface of Human Pancreatic β Cells. Metabolites 2021; 11:metabo11060363. [PMID: 34200432 PMCID: PMC8229564 DOI: 10.3390/metabo11060363] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 11/16/2022] Open
Abstract
Pancreatic β cells secrete the hormone insulin into the bloodstream and are critical in the control of blood glucose concentrations. β cells are clustered in the micro-organs of the islets of Langerhans, which have a rich capillary network. Recent work has highlighted the intimate spatial connections between β cells and these capillaries, which lead to the targeting of insulin secretion to the region where the β cells contact the capillary basement membrane. In addition, β cells orientate with respect to the capillary contact point and many proteins are differentially distributed at the capillary interface compared with the rest of the cell. Here, we set out to develop an automated image analysis approach to identify individual β cells within intact islets and to determine if the distribution of insulin across the cells was polarised. Our results show that a U-Net machine learning algorithm correctly identified β cells and their orientation with respect to the capillaries. Using this information, we then quantified insulin distribution across the β cells to show enrichment at the capillary interface. We conclude that machine learning is a useful analytical tool to interrogate large image datasets and analyse sub-cellular organisation.
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Affiliation(s)
- Louise Cottle
- Charles Perkins Centre, School of Medical Sciences, University of Sydney, Camperdown 2006, Australia
| | - Ian Gilroy
- School of Computer Science, University of Sydney, Camperdown 2006, Australia
| | - Kylie Deng
- Charles Perkins Centre, School of Medical Sciences, University of Sydney, Camperdown 2006, Australia
| | | | - Helen E Thomas
- St Vincent's Institute, Fitzroy 3065, Australia
- Department of Medicine, St Vincent's Hospital, University of Melbourne, Fitzroy 3065, Australia
| | - Anthony J Gill
- Northern Clinical School, University of Sydney, St Leonards 2065, Australia
- Department of Anatomical Pathology, Royal North Shore Hospital, St Leonards 2065, Australia
- Cancer Diagnosis and Pathology Research Group, Kolling Institute of Medical Research, St Leonards 2065, Australia
| | - Jaswinder S Samra
- Northern Clinical School, University of Sydney, St Leonards 2065, Australia
- Upper Gastrointestinal Surgical Unit, Royal North Shore Hospital, St Leonards 2065, Australia
| | - Melkam A Kebede
- Charles Perkins Centre, School of Medical Sciences, University of Sydney, Camperdown 2006, Australia
| | - Jinman Kim
- School of Computer Science, University of Sydney, Camperdown 2006, Australia
| | - Peter Thorn
- Charles Perkins Centre, School of Medical Sciences, University of Sydney, Camperdown 2006, Australia
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Félix-Martínez GJ, N. Mata A, Godínez-Fernández JR. Reconstructing human pancreatic islet architectures using computational optimization. Islets 2020; 12:121-133. [PMID: 33090076 PMCID: PMC7751670 DOI: 10.1080/19382014.2020.1823178] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We outline a general methodology based on computational optimization and experimental data to reconstruct human pancreatic islet architectures. By using the nuclei coordinates of islet cells obtained through DAPI staining, cell types identified by immunostaining, and cell size distributions estimated from capacitance measurements, reconstructed islets composed of non-overlapping spherical cells were obtained through an iterative optimization procedure. In all cases, the reconstructed architectures included >99% of the experimental identified cells, each of them having a radius within the experimentally reported ranges. Given the wide use of mathematical modeling for the study of pancreatic cells, and recently, of cell-cell interactions within the pancreatic islets, the methodology here proposed, also capable of identifying cell-to-cell contacts, is aimed to provide with a framework for modeling and analyzing experimentally-based pancreatic islet architectures.
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Affiliation(s)
- Gerardo J. Félix-Martínez
- Cátedras CONACYT, Consejo Nacional de Ciencia y Tecnología, Mexico City, México
- Department of Electrical Engineering, Universidad Autónoma Metropolitana, Mexico City, México
- CONTACT Gerardo J. Félix-Martínez Laboratory of Biophysics AT-221, Universidad Autónoma Metropolitana; San Rafael Atlixco 186, Col. Vicentina, 09340, Iztalapapa, CDMX, México
| | - Aurelio N. Mata
- Department of Electrical Engineering, Universidad Autónoma Metropolitana, Mexico City, México
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Zhao YF, Li XC, Liang XY, Zhao YY, Xie R, Zhang LJ, Zhang XC, Chen C. GPR120 Regulates Pancreatic Polypeptide Secretion From Male Mouse Islets via PLC-Mediated Calcium Mobilization. Endocrinology 2020; 161:5900686. [PMID: 32877513 DOI: 10.1210/endocr/bqaa157] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 08/29/2020] [Indexed: 02/07/2023]
Abstract
The free fatty acid receptor G protein-coupled receptor 120 (GPR120) is expressed in pancreatic islets, but its specific cell distribution and function have not been fully established. In this study, a GPR120-IRES-EGFP knockin (KI) mouse was generated to identify GPR120-expressing cells with enhanced green fluorescence proteins (EGFP). EGFP-positive cells collected from KI mouse islets by flow cytometry had a significantly higher expression of pancreatic polypeptide (PP) evidenced by reverse transcriptase (RT)-quantitative polymerase chain reaction (qPCR). Single-cell RT-PCR and immunocytochemical double staining also demonstrated the coexpression of GPR120 with PP in mouse islets. The GPR120-specific agonist TUG-891 significantly increased plasma PP levels in mice. TUG-891 significantly increased PP levels in islet medium in vitro, which was markedly attenuated by GPR120 small interfering RNA treatment. TUG-891-stimulated PP secretion in islets was fully blocked by pretreatment with YM-254890 (a Gq protein inhibitor), U73122 (a phospholipase C inhibitor), or thapsigargin (an inducer of endoplasmic reticulum Ca2+ depletion), respectively. TUG-891 triggered the increase in intracellular free Ca2+ concentrations ([Ca2+]i) in PP cells, which was also eliminated by YM-254890, U73122, or thapsigargin. GPR120 gene expression was significantly reduced in islets of high-fat diet (HFD)-induced obese mice. TUG-891-stimulated PP secretion was also significantly diminished in vivo and in vitro in HFD-induced obese mice compared with that in normal-chow diet control mice. In summary, this study demonstrated that GPR120 is expressed in mouse islet PP cells and GPR120 activation stimulated PP secretion via the Gq/PLC-Ca2+ signaling pathway in normal-chow diet mice but with diminished effects in HFD-induced obese mice.
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Affiliation(s)
- Yu-Feng Zhao
- Institute of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Xiao-Cheng Li
- Institute of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Xiang-Yan Liang
- Institute of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Yan-Yan Zhao
- Institute of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Rong Xie
- Institute of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Li-Jun Zhang
- Institute of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Xiao-Chun Zhang
- Institute of Basic Medical Sciences, Xi'an Medical University, Xi'an, China
| | - Chen Chen
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
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Lorza-Gil E, Gerst F, Oquendo MB, Deschl U, Häring HU, Beilmann M, Ullrich S. Glucose, adrenaline and palmitate antagonistically regulate insulin and glucagon secretion in human pseudoislets. Sci Rep 2019; 9:10261. [PMID: 31311971 PMCID: PMC6635387 DOI: 10.1038/s41598-019-46545-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/26/2019] [Indexed: 11/09/2022] Open
Abstract
Isolated human islets do not always meet the quality standards required for transplant survival and reliable functional in vitro studies. The formation of pseudoislets, i.e. the reaggregation of a defined number of islet cells after dissociation, improves insulin secretion. We present a simple method of pseudoislet formation from human islet cells and assess the transcriptome and function of isolated human islets and pseudoislets from the same organ donors. Following pseudoislet formation, insulin content/DNA and mRNA/RPS13 resembled that of islets. In pseudoislets, glucose-stimulated insulin secretion (GSIS) was significantly higher (8–13-fold) than in islets (2–4-fold). GSIS of pseudoislets was partly inhibited by the glucagon-like peptide-1 receptor (GLP-1R) antagonist exendin-9. The stimulatory effects of palmitate and forskolin at 12 mM glucose were also significantly higher in pseudoislets than in islets. Further analysis of pseudoislets revealed that regulation of secretion and insulin and glucagon content was maintained over a longer culture period (6–14 d). While adrenaline inhibited GSIS, adrenaline together with palmitate stimulated glucagon secretion 2-fold at low glucose, an effect suppressed by high glucose. Transcriptome analysis revealed that, unlike islets, pseudoislets were deprived of exocrine and endothelial cells. In conclusion, pseudoislet formation restores functional integrity of human islet cells and allows long-term in vitro testing.
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Affiliation(s)
- Estela Lorza-Gil
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen (IDM), Tübingen, Germany.,University Hospital Tübingen, Internal Medicine IV, Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
| | - Felicia Gerst
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen (IDM), Tübingen, Germany.,University Hospital Tübingen, Internal Medicine IV, Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
| | - Morgana Barroso Oquendo
- University Hospital Tübingen, Internal Medicine IV, Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
| | - Ulrich Deschl
- Boehringer Ingelheim Pharma GmbH & Co. KG, Nonclinical Drug Safety, Biberach, Germany
| | - Hans-Ulrich Häring
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany.,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen (IDM), Tübingen, Germany.,University Hospital Tübingen, Internal Medicine IV, Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany
| | - Mario Beilmann
- Boehringer Ingelheim Pharma GmbH & Co. KG, Nonclinical Drug Safety, Biberach, Germany
| | - Susanne Ullrich
- German Center for Diabetes Research (DZD e.V.), Tübingen, Germany. .,Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen (IDM), Tübingen, Germany. .,University Hospital Tübingen, Internal Medicine IV, Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, Tübingen, Germany.
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7
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Proshchina AE, Krivova YS, Barabanov VM, Saveliev SV. Pancreatic endocrine cell arrangement during human ontogeny. Acta Histochem 2019; 121:638-645. [PMID: 31146895 DOI: 10.1016/j.acthis.2019.05.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 05/17/2019] [Accepted: 05/22/2019] [Indexed: 12/19/2022]
Abstract
In the human pancreas, various forms of endocrine cell arrangement are found: single endocrine cells, endocrine cell clusters, and mantel, bipolar and mosaic cell (mixed) islets. Our aim was to analyse the distribution and dynamics of insulin-, glucagon- and somatostatin-containing cells within the various forms of endocrine pancreas arrangement during human prenatal development and in adults and to suggest a mechanism of change in the endocrine cell ratio in adult islets. Pancreatic autopsies derived from human foetuses from the 10th to the 40th weeks of development and from adults were examined using histological, immunohistochemical and morphometric methods. During development, the human endocrine pancreas undergoes not only de novo differentiation of endocrine cells and islet formation, but morphogenetic restructuring, which is revealed as a change of the α-, β- and δ-cell ratio in the islets. In particular, increased proportion of glucagon- and somatostatin-containing cells and decreased proportion of β-cells were shown in the largest mosaic islets in adults. Our results indicate that the distribution and proportion of α-, β- and δ-cells depend on the islets size and vascularisation. Studying of the mechanism of such restructuring may contribute to the development of new approaches in the treatment of diabetes mellitus.
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