1
|
Liu L, Kimberley EI, Dattaroy D, Barella LF, Cui Y, Guedikian C, Chen M, Weinstein LS, Knuth E, Jin E, Merrins MJ, Roman J, Kaestner KH, Doliba N, Campbell JE, Wess J. Intra-islet α-cell Gs signaling promotes glucagon release. Nat Commun 2024; 15:5129. [PMID: 38879678 PMCID: PMC11180188 DOI: 10.1038/s41467-024-49537-x] [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] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 06/07/2024] [Indexed: 06/19/2024] Open
Abstract
Glucagon, a hormone released from pancreatic α-cells, is critical for maintaining euglycemia and plays a key role in the pathophysiology of diabetes. To stimulate the development of new classes of therapeutic agents targeting glucagon release, key α-cell signaling pathways that regulate glucagon secretion need to be identified. Here, we focused on the potential importance of α-cell Gs signaling on modulating α-cell function. Studies with α-cell-specific mouse models showed that activation of α-cell Gs signaling causes a marked increase in glucagon secretion. We also found that intra-islet adenosine plays an unexpected autocrine/paracrine role in promoting glucagon release via activation of α-cell Gs-coupled A2A adenosine receptors. Studies with α-cell-specific Gαs knockout mice showed that α-cell Gs also plays an essential role in stimulating the activity of the Gcg gene, thus ensuring proper islet glucagon content. Our data suggest that α-cell enriched Gs-coupled receptors represent potential targets for modulating α-cell function for therapeutic purposes.
Collapse
Affiliation(s)
- Liu Liu
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
| | - E I Kimberley
- Duke Molecular Physiology Institute, Duke University, Durham, NC, 27701, USA
| | - Diptadip Dattaroy
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Luiz F Barella
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Yinghong Cui
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Carla Guedikian
- Duke Molecular Physiology Institute, Duke University, Durham, NC, 27701, USA
| | - Min Chen
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Lee S Weinstein
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA
| | - Emily Knuth
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Erli Jin
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Matthew J Merrins
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Jeffrey Roman
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Klaus H Kaestner
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Nicolai Doliba
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, Duke University, Durham, NC, 27701, USA
| | - Jürgen Wess
- Molecular Signaling Section, LBC, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 20892, USA.
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Paradiž Leitgeb E, Kerčmar J, Križančić Bombek L, Pohorec V, Skelin Klemen M, Slak Rupnik M, Gosak M, Dolenšek J, Stožer A. Exendin-4 affects calcium signalling predominantly during activation and activity of beta cell networks in acute mouse pancreas tissue slices. Front Endocrinol (Lausanne) 2024; 14:1315520. [PMID: 38292770 PMCID: PMC10826511 DOI: 10.3389/fendo.2023.1315520] [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: 10/10/2023] [Accepted: 12/22/2023] [Indexed: 02/01/2024] Open
Abstract
Tight control of beta cell stimulus-secretion coupling is crucial for maintaining homeostasis of energy-rich nutrients. While glucose serves as a primary regulator of this process, incretins augment beta cell function, partly by enhancing cytosolic [Ca2+] dynamics. However, the details of how precisely they affect beta cell recruitment during activation, their active time, and functional connectivity during plateau activity, and how they influence beta cell deactivation remain to be described. Performing functional multicellular Ca2+ imaging in acute mouse pancreas tissue slices enabled us to systematically assess the effects of the GLP-1 receptor agonist exendin-4 (Ex-4) simultaneously in many coupled beta cells with high resolution. In otherwise substimulatory glucose, Ex-4 was able to recruit approximately a quarter of beta cells into an active state. Costimulation with Ex-4 and stimulatory glucose shortened the activation delays and accelerated beta cell activation dynamics. More specifically, active time increased faster, and the time required to reach half-maximal activation was effectively halved in the presence of Ex-4. Moreover, the active time and regularity of [Ca2+]IC oscillations increased, especially during the first part of beta cell response. In contrast, subsequent addition of Ex-4 to already active cells did not significantly enhance beta cell activity. Network analyses further confirmed increased connectivity during activation and activity in the presence of Ex-4, with hub cell roles remaining rather stable in both control experiments and experiments with Ex-4. Interestingly, Ex-4 demonstrated a biphasic effect on deactivation, slightly prolonging beta cell activity at physiological concentrations and shortening deactivation delays at supraphysiological concentrations. In sum, costimulation by Ex-4 and glucose increases [Ca2+]IC during beta cell activation and activity, indicating that the effect of incretins may, to an important extent, be explained by enhanced [Ca2+]IC signals. During deactivation, previous incretin stimulation does not critically prolong cellular activity, which corroborates their low risk of hypoglycemia.
Collapse
Affiliation(s)
- Eva Paradiž Leitgeb
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Jasmina Kerčmar
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | | | - Vilijem Pohorec
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
- Alma Mater Europaea-European Center Maribor, Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Alma Mater Europaea-European Center Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, Maribor, Slovenia
| |
Collapse
|
4
|
Weir GC, Bonner-Weir S. Conflicting Views About Interactions Between Pancreatic α-Cells and β-Cells. Diabetes 2023; 72:1741-1747. [PMID: 37983524 PMCID: PMC10658062 DOI: 10.2337/db23-0292] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 08/16/2023] [Indexed: 11/22/2023]
Abstract
In type 1 diabetes, the reduced glucagon response to insulin-induced hypoglycemia has been used to argue that β-cell secretion of insulin is required for the full glucagon counterregulatory response. For years, the concept has been that insulin from the β-cell core flows downstream to suppress glucagon secretion from the α-cells in the islet mantle. This core-mantle relationship has been supported by perfused pancreas studies that show marked increases in glucagon secretion when insulin was neutralized with antisera. Additional support comes from a growing number of studies focused on vascular anatomy and blood flow. However, in recent years this core-mantle view has generated less interest than the argument that optimal insulin secretion is due to paracrine release of glucagon from α-cells stimulating adjacent β-cells. This mechanism has been evaluated by knockout of β-cell receptors and impairment of α-cell function by inhibition of Gi designer receptors exclusively activated by designer drugs. Other studies that support this mechanism have been obtained by pharmacological blocking of glucagon-like peptide 1 receptor in humans. While glucagon has potent effects on β-cells, there are concerns with the suggested paracrine mechanism, since some of the supporting data are from isolated islets. The study of islets in static incubation or perifusion systems can be informative, but the normal paracrine relationships are disrupted by the isolation process. While this complicates interpretation of data, arguments supporting paracrine interactions between α-cells and β-cells have growing appeal. We discuss these conflicting views of the relationship between pancreatic α-cells and β-cells and seek to understand how communication depends on blood flow and/or paracrine mechanisms.
Collapse
Affiliation(s)
- Gordon C. Weir
- Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | | |
Collapse
|
5
|
Zaïmia N, Obeid J, Varrault A, Sabatier J, Broca C, Gilon P, Costes S, Bertrand G, Ravier MA. GLP-1 and GIP receptors signal through distinct β-arrestin 2-dependent pathways to regulate pancreatic β cell function. Cell Rep 2023; 42:113326. [PMID: 37897727 DOI: 10.1016/j.celrep.2023.113326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/14/2023] [Accepted: 10/07/2023] [Indexed: 10/30/2023] Open
Abstract
Glucagon-like peptide 1 (GLP-1R) and glucose-dependent insulinotropic polypeptide (GIPR) receptors are G-protein-coupled receptors involved in glucose homeostasis. Diabetogenic conditions decrease β-arrestin 2 (ARRB2) levels in human islets. In mouse β cells, ARRB2 dampens insulin secretion by partially uncoupling cyclic AMP (cAMP)/protein kinase A (PKA) signaling at physiological doses of GLP-1, whereas at pharmacological doses, the activation of extracellular signal-related kinase (ERK)/cAMP-responsive element-binding protein (CREB) requires ARRB2. In contrast, GIP-potentiated insulin secretion needs ARRB2 in mouse and human islets. The GIPR-ARRB2 axis is not involved in cAMP/PKA or ERK signaling but does mediate GIP-induced F-actin depolymerization. Finally, the dual GLP-1/GIP agonist tirzepatide does not require ARRB2 for the potentiation of insulin secretion. Thus, ARRB2 plays distinct roles in regulating GLP-1R and GIPR signaling, and we highlight (1) its role in the physiological context and the possible functional consequences of its decreased expression in pathological situations such as diabetes and (2) the importance of assessing the signaling pathways engaged by the agonists (biased/dual) for therapeutic purposes.
Collapse
Affiliation(s)
- Nour Zaïmia
- IGF, Université Montpellier, CNRS, INSERM, Montpellier, France
| | - Joelle Obeid
- IGF, Université Montpellier, CNRS, INSERM, Montpellier, France
| | - Annie Varrault
- IGF, Université Montpellier, CNRS, INSERM, Montpellier, France
| | | | | | - Patrick Gilon
- Université Catholique de Louvain, Institut de Recherche Expérimental et Clinique, Pôle d'Endocrinologie, Diabète, et Nutrition, Brussels, Belgium
| | - Safia Costes
- IGF, Université Montpellier, CNRS, INSERM, Montpellier, France
| | | | | |
Collapse
|
6
|
Welch AA, Farahani RA, Egan AM, Laurenti MC, Zeini M, Vella M, Bailey KR, Cobelli C, Dalla Man C, Matveyenko A, Vella A. Glucagon-like peptide-1 receptor blockade impairs islet secretion and glucose metabolism in humans. J Clin Invest 2023; 133:e173495. [PMID: 37751301 PMCID: PMC10645389 DOI: 10.1172/jci173495] [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: 07/07/2023] [Accepted: 09/12/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUNDProglucagon can be processed to glucagon-like peptide1 (GLP-1) within the islet, but its contribution to islet function in humans remains unknown. We sought to understand whether pancreatic GLP-1 alters islet function in humans and whether this is affected by type 2 diabetes.METHODSWe therefore studied individuals with and without type 2 diabetes on two occasions in random order. On one occasion, exendin 9-39, a competitive antagonist of the GLP-1 Receptor (GLP1R), was infused, while on the other, saline was infused. The tracer dilution technique ([3-3H] glucose) was used to measure glucose turnover during fasting and during a hyperglycemic clamp.RESULTSExendin 9-39 increased fasting glucose concentrations; fasting islet hormone concentrations were unchanged, but inappropriate for the higher fasting glucose observed. In people with type 2 diabetes, fasting glucagon concentrations were markedly elevated and persisted despite hyperglycemia. This impaired suppression of endogenous glucose production by hyperglycemia.CONCLUSIONThese data show that GLP1R blockade impairs islet function, implying that intra-islet GLP1R activation alters islet responses to glucose and does so to a greater degree in people with type 2 diabetes.TRIAL REGISTRATIONThis study was registered at ClinicalTrials.gov NCT04466618.FUNDINGThe study was primarily funded by NIH NIDDK DK126206. AV is supported by DK78646, DK116231 and DK126206. CDM was supported by MIUR (Italian Minister for Education) under the initiative "Departments of Excellence" (Law 232/2016).
Collapse
Affiliation(s)
- Andrew A. Welch
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Rahele A. Farahani
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Aoife M. Egan
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Marcello C. Laurenti
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Maya Zeini
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Max Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Kent R. Bailey
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Chiara Dalla Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Aleksey Matveyenko
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Adrian Vella
- Division of Endocrinology, Diabetes & Metabolism, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| |
Collapse
|
7
|
Fadzeyeva E, Locatelli CA, Trzaskalski NA, Nguyen MA, Capozzi ME, Vulesevic B, Morrow NM, Ghorbani P, Hanson AA, Lorenzen-Schmidt I, Doyle MA, Seymour R, Varin EM, Fullerton MD, Campbell JE, Mulvihill EE. Pancreas-derived DPP4 is not essential for glucose homeostasis under metabolic stress. iScience 2023; 26:106748. [PMID: 37216093 PMCID: PMC10192926 DOI: 10.1016/j.isci.2023.106748] [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] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 03/09/2023] [Accepted: 04/21/2023] [Indexed: 05/24/2023] Open
Abstract
Mice systemically lacking dipeptidyl peptidase-4 (DPP4) have improved islet health, glucoregulation, and reduced obesity with high-fat diet (HFD) feeding compared to wild-type mice. Some, but not all, of this improvement can be linked to the loss of DPP4 in endothelial cells (ECs), pointing to the contribution of non-EC types. The importance of intra-islet signaling mediated by α to β cell communication is becoming increasingly clear; thus, our objective was to determine if β cell DPP4 regulates insulin secretion and glucose tolerance in HFD-fed mice by regulating the local concentrations of insulinotropic peptides. Using β cell double incretin receptor knockout mice, β cell- and pancreas-specific Dpp4-/- mice, we reveal that β cell incretin receptors are necessary for DPP4 inhibitor effects. However, although β cell DPP4 modestly contributes to high glucose (16.7 mM)-stimulated insulin secretion in isolated islets, it does not regulate whole-body glucose homeostasis.
Collapse
Affiliation(s)
- Evgenia Fadzeyeva
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
| | - Cassandra A.A. Locatelli
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
| | - Natasha A. Trzaskalski
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
| | - My-Anh Nguyen
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
| | - Megan E. Capozzi
- Duke Molecular Physiology Institute, 300 North Duke Street, Durham, NC 27701, USA
| | - Branka Vulesevic
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
| | - Nadya M. Morrow
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
| | - Peyman Ghorbani
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
| | - Antonio A. Hanson
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
| | - Ilka Lorenzen-Schmidt
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
| | - Mary-Anne Doyle
- Division of Endocrinology & Metabolism, Department of Medicine, University of Ottawa, Ottawa, ON K1H 8L6, Canada
| | - Richard Seymour
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
| | - Elodie M. Varin
- Lunenfeld Tanenbaum Research Institute, Toronto, ON M5G 1X5, Canada
| | - Morgan D. Fullerton
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
- Centre for Infection, Immunity and Inflammation, Ottawa, ON K1H 8M5, Canada
| | - Jonathan E. Campbell
- Duke Molecular Physiology Institute, 300 North Duke Street, Durham, NC 27701, USA
| | - Erin E. Mulvihill
- The University of Ottawa, Faculty of Medicine, Department of Biochemistry, Microbiology and Immunology, Ottawa, ON K1H 8M5, Canada
- The University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, ON K1Y4W7, Canada
- Centre for Infection, Immunity and Inflammation, Ottawa, ON K1H 8M5, Canada
- Montreal Diabetes Research Group, Montreal, QC H2X 0A9, Canada
| |
Collapse
|
8
|
Esser N, Mundinger TO, Barrow BM, Zraika S. Acute Inhibition of Intestinal Neprilysin Enhances Insulin Secretion via GLP-1 Receptor Signaling in Male Mice. Endocrinology 2023; 164:bqad055. [PMID: 36964914 PMCID: PMC10282919 DOI: 10.1210/endocr/bqad055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 03/15/2023] [Accepted: 03/22/2023] [Indexed: 03/26/2023]
Abstract
The peptidase neprilysin modulates glucose homeostasis by cleaving and inactivating insulinotropic peptides, including some produced in the intestine such as glucagon-like peptide-1 (GLP-1). Under diabetic conditions, systemic or islet-selective inhibition of neprilysin enhances beta-cell function through GLP-1 receptor (GLP-1R) signaling. While neprilysin is expressed in intestine, its local contribution to modulation of beta-cell function remains unknown. We sought to determine whether acute selective pharmacological inhibition of intestinal neprilysin enhanced glucose-stimulated insulin secretion under physiological conditions, and whether this effect was mediated through GLP-1R. Lean chow-fed Glp1r+/+ and Glp1r-/- mice received a single oral low dose of the neprilysin inhibitor thiorphan or vehicle. To confirm selective intestinal neprilysin inhibition, neprilysin activity in plasma and intestine (ileum and colon) was assessed 40 minutes after thiorphan or vehicle administration. In a separate cohort of mice, an oral glucose tolerance test was performed 30 minutes after thiorphan or vehicle administration to assess glucose-stimulated insulin secretion. Systemic active GLP-1 levels were measured in plasma collected 10 minutes after glucose administration. In both Glp1r+/+ and Glp1r-/- mice, thiorphan inhibited neprilysin activity in ileum and colon without altering plasma neprilysin activity or active GLP-1 levels. Further, thiorphan significantly increased insulin secretion in Glp1r+/+ mice, whereas it did not change insulin secretion in Glp1r-/- mice. In conclusion, under physiological conditions, acute pharmacological inhibition of intestinal neprilysin increases glucose-stimulated insulin secretion in a GLP-1R-dependent manner. Since intestinal neprilysin modulates beta-cell function, strategies to inhibit its activity specifically in the intestine may improve beta-cell dysfunction in type 2 diabetes.
Collapse
Affiliation(s)
- Nathalie Esser
- Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA 98195, USA
- Laboratory of Immunometabolism and Nutrition, GIGA-I3, CHU Liège, University of Liège, Liège, Belgium
| | - Thomas O Mundinger
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Breanne M Barrow
- Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
| | - Sakeneh Zraika
- Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| |
Collapse
|
9
|
Bosch AJT, Rohm TV, AlAsfoor S, Low AJY, Keller L, Baumann Z, Parayil N, Stawiski M, Rachid L, Dervos T, Mitrovic S, Meier DT, Cavelti-Weder C. Lung versus gut exposure to air pollution particles differentially affect metabolic health in mice. Part Fibre Toxicol 2023; 20:7. [PMID: 36895000 PMCID: PMC9996885 DOI: 10.1186/s12989-023-00518-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/14/2023] [Indexed: 03/11/2023] Open
Abstract
BACKGROUND Air pollution has emerged as an unexpected risk factor for diabetes. However, the mechanism behind remains ill-defined. So far, the lung has been considered as the main target organ of air pollution. In contrast, the gut has received little scientific attention. Since air pollution particles can reach the gut after mucociliary clearance from the lungs and through contaminated food, our aim was to assess whether exposure deposition of air pollution particles in the lung or the gut drive metabolic dysfunction in mice. METHODS To study the effects of gut versus lung exposure, we exposed mice on standard diet to diesel exhaust particles (DEP; NIST 1650b), particulate matter (PM; NIST 1649b) or phosphate-buffered saline by either intratracheal instillation (30 µg 2 days/week) or gavage (12 µg 5 days/week) over at least 3 months (total dose of 60 µg/week for both administration routes, equivalent to a daily inhalation exposure in humans of 160 µg/m3 PM2.5) and monitored metabolic parameters and tissue changes. Additionally, we tested the impact of the exposure route in a "prestressed" condition (high-fat diet (HFD) and streptozotocin (STZ)). RESULTS Mice on standard diet exposed to particulate air pollutants by intratracheal instillation developed lung inflammation. While both lung and gut exposure resulted in increased liver lipids, glucose intolerance and impaired insulin secretion was only observed in mice exposed to particles by gavage. Gavage with DEP created an inflammatory milieu in the gut as shown by up-regulated gene expression of pro-inflammatory cytokines and monocyte/macrophage markers. In contrast, liver and adipose inflammation markers were not increased. Beta-cell secretory capacity was impaired on a functional level, most likely induced by the inflammatory milieu in the gut, and not due to beta-cell loss. The differential metabolic effects of lung and gut exposures were confirmed in a "prestressed" HFD/STZ model. CONCLUSIONS We conclude that separate lung and gut exposures to air pollution particles lead to distinct metabolic outcomes in mice. Both exposure routes elevate liver lipids, while gut exposure to particulate air pollutants specifically impairs beta-cell secretory capacity, potentially instigated by an inflammatory milieu in the gut.
Collapse
Affiliation(s)
- Angela J T Bosch
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Theresa V Rohm
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Shefaa AlAsfoor
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Andy J Y Low
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Lena Keller
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Zora Baumann
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Neena Parayil
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Marc Stawiski
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Leila Rachid
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Thomas Dervos
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Sandra Mitrovic
- Department of Laboratory Medicine, University Hospital Basel, 4031, Basel, Switzerland
| | - Daniel T Meier
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland
| | - Claudia Cavelti-Weder
- Department of Biomedicine, University of Basel, 4031, Basel, Switzerland. .,Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, 4031, Basel, Switzerland. .,Department of Endocrinology, Diabetology and Clinical Nutrition, University Hospital Zurich (USZ) and University of Zurich (UZH), Rämistrasse 100, 8009, Zurich, Switzerland.
| |
Collapse
|
10
|
Thomas MC, Coughlan MT, Cooper ME. The postprandial actions of GLP-1 receptor agonists: The missing link for cardiovascular and kidney protection in type 2 diabetes. Cell Metab 2023; 35:253-273. [PMID: 36754019 DOI: 10.1016/j.cmet.2023.01.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Recent clinical trials in people with type 2 diabetes have demonstrated beneficial actions on heart and kidney outcomes following treatment with GLP-1RAs. In part, these actions are consistent with improved glucose control and significant weight loss. But GLP-1RAs may also have additive benefits by improving postprandial dysmetabolism. In diabetes, dysregulated postprandial nutrient excursions trigger inflammation, oxidative stress, endothelial dysfunction, thrombogenicity, and endotoxemia; alter hormone levels; and modulate cardiac output and regional blood and lymphatic flow. In this perspective, we explore the actions of GLP-1RAs on the postprandial state and their potential role in end-organ benefits observed in recent trials.
Collapse
Affiliation(s)
- Merlin C Thomas
- Department of Diabetes, Monash University, Central Clinical School, 99 Commercial Road, Melbourne, Australia; Department of Biochemistry, Monash University, Melbourne, Australia
| | - Melinda T Coughlan
- Department of Diabetes, Monash University, Central Clinical School, 99 Commercial Road, Melbourne, Australia; Drug Discovery Biology, Monash Institute of Pharmaceutical Science, Monash University Parkville Campus, 381 Royal Parade, Parkville, 3052 VIC, Australia
| | - Mark E Cooper
- Department of Diabetes, Monash University, Central Clinical School, 99 Commercial Road, Melbourne, Australia.
| |
Collapse
|
11
|
Wang K, Cui X, Li F, Xia L, Wei T, Liu J, Fu W, Yang J, Hong T, Wei R. Glucagon receptor blockage inhibits β-cell dedifferentiation through FoxO1. Am J Physiol Endocrinol Metab 2023; 324:E97-E113. [PMID: 36383639 DOI: 10.1152/ajpendo.00101.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glucagon-secreting pancreatic α-cells play pivotal roles in the development of diabetes. Glucagon promotes insulin secretion from β-cells. However, the long-term effect of glucagon on the function and phenotype of β-cells had remained elusive. In this study, we found that long-term glucagon intervention or glucagon intervention with the presence of palmitic acid downregulated β-cell-specific markers and inhibited insulin secretion in cultured β-cells. These results suggested that glucagon induced β-cell dedifferentiation under pathological conditions. Glucagon blockage by a glucagon receptor (GCGR) monoclonal antibody (mAb) attenuated glucagon-induced β-cell dedifferentiation. In primary islets, GCGR mAb treatment upregulated β-cell-specific markers and increased insulin content, suggesting that blockage of endogenous glucagon-GCGR signaling inhibited β-cell dedifferentiation. To investigate the possible mechanism, we found that glucagon decreased FoxO1 expression. FoxO1 inhibitor mimicked the effect of glucagon, whereas FoxO1 overexpression reversed the glucagon-induced β-cell dedifferentiation. In db/db mice and β-cell lineage-tracing diabetic mice, GCGR mAb lowered glucose level, upregulated plasma insulin level, increased β-cell area, and inhibited β-cell dedifferentiation. In aged β-cell-specific FoxO1 knockout mice (with the blood glucose level elevated as a diabetic model), the glucose-lowering effect of GCGR mAb was attenuated and the plasma insulin level, β-cell area, and β-cell dedifferentiation were not affected by GCGR mAb. Our results proved that glucagon induced β-cell dedifferentiation under pathological conditions, and the effect was partially mediated by FoxO1. Our study reveals a novel cross talk between α- and β-cells and is helpful to understand the pathophysiology of diabetes and discover new targets for diabetes treatment.NEW & NOTEWORTHY Glucagon-secreting pancreatic α-cells can interact with β-cells. However, the long-term effect of glucagon on the function and phenotype of β-cells has remained elusive. Our new finding shows that long-term glucagon induces β-cell dedifferentiation in cultured β-cells. FoxO1 inhibitor mimicks whereas glucagon signaling blockage by GCGR mAb reverses the effect of glucagon. In type 2 diabetic mice, GCGR mAb increases β-cell area, improves β-cell function, and inhibits β-cell dedifferentiation, and the effect is partially mediated by FoxO1.
Collapse
Affiliation(s)
- Kangli Wang
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Xiaona Cui
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Fei Li
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Li Xia
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Tianjiao Wei
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Junling Liu
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Wei Fu
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
| | - Jin Yang
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Tianpei Hong
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| | - Rui Wei
- Department of Endocrinology and Metabolism, https://ror.org/04wwqze12Peking University Third Hospital, Beijing, China
- Clinical Stem Cell Research Center, Peking University Third Hospital, Beijing, China
| |
Collapse
|
12
|
Capozzi ME, D'Alessio DA, Campbell JE. The past, present, and future physiology and pharmacology of glucagon. Cell Metab 2022; 34:1654-1674. [PMID: 36323234 PMCID: PMC9641554 DOI: 10.1016/j.cmet.2022.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/23/2022] [Accepted: 09/30/2022] [Indexed: 11/07/2022]
Abstract
The evolution of glucagon has seen the transition from an impurity in the preparation of insulin to the development of glucagon receptor agonists for use in type 1 diabetes. In type 2 diabetes, glucagon receptor antagonists have been explored to reduce glycemia thought to be induced by hyperglucagonemia. However, the catabolic actions of glucagon are currently being leveraged to target the rise in obesity that paralleled that of diabetes, bringing the pharmacology of glucagon full circle. During this evolution, the physiological importance of glucagon advanced beyond the control of hepatic glucose production, incorporating critical roles for glucagon to regulate both lipid and amino acid metabolism. Thus, it is unsurprising that the study of glucagon has left several paradoxes that make it difficult to distill this hormone down to a simplified action. Here, we describe the history of glucagon from the past to the present and suggest some direction to the future of this field.
Collapse
Affiliation(s)
- Megan E Capozzi
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA
| | - David A D'Alessio
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Endocrinology Division, Duke University Medical Center, Durham, NC 27701, USA
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, Duke University Medical Center, Durham, NC 27701, USA; Department of Medicine, Endocrinology Division, Duke University Medical Center, Durham, NC 27701, USA; Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27701, USA.
| |
Collapse
|
13
|
Gray SM, Hoselton AL, Krishna R, Slentz CA, D’Alessio DA. GLP-1 Receptor Blockade Reduces Stimulated Insulin Secretion in Fasted Subjects With Low Circulating GLP-1. J Clin Endocrinol Metab 2022; 107:2500-2510. [PMID: 35775723 PMCID: PMC9387711 DOI: 10.1210/clinem/dgac396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Glucagon-like peptide 1 (GLP-1), an insulinotropic peptide released into the circulation from intestinal enteroendocrine cells, is considered a hormonal mediator of insulin secretion. However, the physiological actions of circulating GLP-1 have been questioned because of the short half-life of the active peptide. Moreover, there is mounting evidence for localized, intra-islet mediation of GLP-1 receptor (GLP-1r) signaling including a role for islet dipeptidyl-peptidase 4 (DPP4). OBJECTIVE To determine whether GLP-1r signaling contributes to insulin secretion in the absence of enteral stimulation and increased plasma levels, and whether this is affected by DPP4. METHODS Single-site study conducted at an academic medical center of 20 nondiabetic subjects and 13 subjects with type 2 diabetes. This was a crossover study in which subjects received either a DPP4 inhibitor (DPP4i; sitagliptin) or placebo on 2 separate days. On each day they received a bolus of intravenous (IV) arginine during sequential 60-minute infusions of the GLP-1r blocker exendin[9-39] (Ex-9) and saline. The main outcome measures were arginine-stimulated secretion of C-Peptide (C-PArg) and insulin (InsArg). RESULTS Plasma GLP-1 remained at fasting levels throughout the experiments and IV arginine stimulated both α- and β-cell secretion in all subjects. Ex-9 infusion reduced C-PArg in both the diabetic and nondiabetic groups by ~14% (P < .03 for both groups). Sitagliptin lowered baseline glycemia but did not affect the primary measures of insulin secretion. However, a significant interaction between sitagliptin and Ex-9 suggested more GLP-1r activation with DPP4i treatment in subjects with diabetes. CONCLUSION GLP-1r activation contributes to β-cell secretion in diabetic and nondiabetic people during α-cell activation, but in the absence of increased circulating GLP-1. These results are compatible with regulation of β-cells by paracrine signals from α-cells. This process may be affected by DPP4 inhibition.
Collapse
Affiliation(s)
- Sarah M Gray
- Duke University Division of Endocrinology, Durham, NC 27710, USA
- Department of Medicine, Durham, NC 27710, USA
- Duke Molecular Physiology Institute, Durham, NC 27710, USA
| | - Andrew L Hoselton
- Department of Medicine, Durham, NC 27710, USA
- Duke Molecular Physiology Institute, Durham, NC 27710, USA
| | - Radha Krishna
- Duke University Division of Endocrinology, Durham, NC 27710, USA
- Department of Medicine, Durham, NC 27710, USA
- Duke Molecular Physiology Institute, Durham, NC 27710, USA
| | - Cris A Slentz
- Department of Medicine, Durham, NC 27710, USA
- Duke Molecular Physiology Institute, Durham, NC 27710, USA
| | - David A D’Alessio
- Correspondence: David A. D’Alessio, MD, Duke University Medical Center, Division of Endocrinology, Metabolism and Nutrition, DUMC Box 3921, Durham, NC 27710, USA. david.d'
| |
Collapse
|
14
|
Meier DT, Rachid L, Wiedemann SJ, Traub S, Trimigliozzi K, Stawiski M, Sauteur L, Winter DV, Le Foll C, Brégère C, Guzman R, Odermatt A, Böni-Schnetzler M, Donath MY. Prohormone convertase 1/3 deficiency causes obesity due to impaired proinsulin processing. Nat Commun 2022; 13:4761. [PMID: 35963866 PMCID: PMC9376086 DOI: 10.1038/s41467-022-32509-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 08/03/2022] [Indexed: 12/12/2022] Open
Abstract
Defective insulin processing is associated with obesity and diabetes. Prohormone convertase 1/3 (PC1/3) is an endopeptidase required for the processing of neurotransmitters and hormones. PC1/3 deficiency and genome-wide association studies relate PC1/3 with early onset obesity. Here, we find that deletion of PC1/3 in obesity-related neuronal cells expressing proopiomelanocortin mildly and transiently change body weight and fail to produce a phenotype when targeted to Agouti-related peptide- or nestin-expressing tissues. In contrast, pancreatic β cell-specific PC1/3 ablation induces hyperphagia with consecutive obesity despite uncontrolled diabetes with glucosuria. Obesity develops not due to impaired pro-islet amyloid polypeptide processing but due to impaired insulin maturation. Proinsulin crosses the blood-brain-barrier but does not induce central satiety. Accordingly, insulin therapy prevents hyperphagia. Further, islet PC1/3 expression levels negatively correlate with body mass index in humans. In this work, we show that impaired PC1/3-mediated proinsulin processing, as observed in human prediabetes, promotes hyperphagic obesity. Defective insulin secretion is observed early in the development of diabetes. Here the authors report that β cell-specific deficiency of the insulin prohormone convertase 1/3 (PC1/3) leads not only to hyperglycemia, but also to hyperphagic obesity in mice.
Collapse
Affiliation(s)
- Daniel T Meier
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Basel, Switzerland. .,Department of Biomedicine, University of Basel, Basel, Switzerland.
| | - Leila Rachid
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Basel, Switzerland.,Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Sophia J Wiedemann
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Basel, Switzerland.,Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Shuyang Traub
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Basel, Switzerland.,Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Kelly Trimigliozzi
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Basel, Switzerland.,Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Marc Stawiski
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Basel, Switzerland.,Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Loïc Sauteur
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Denise V Winter
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Christelle Le Foll
- Institute of Veterinary Physiology, University of Zurich, 8057, Zurich, Switzerland
| | - Catherine Brégère
- Department of Biomedicine, University of Basel, Basel, Switzerland.,Department of Neurosurgery, University of Basel, Basel, Switzerland
| | - Raphael Guzman
- Department of Biomedicine, University of Basel, Basel, Switzerland.,Department of Neurosurgery, University of Basel, Basel, Switzerland
| | - Alex Odermatt
- Division of Molecular and Systems Toxicology, Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland
| | - Marianne Böni-Schnetzler
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Basel, Switzerland.,Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Marc Y Donath
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Basel, Switzerland.,Department of Biomedicine, University of Basel, Basel, Switzerland
| |
Collapse
|
15
|
Holter MM, Phuong DJ, Lee I, Saikia M, Weikert L, Fountain S, Anderson ET, Fu Q, Zhang S, Sloop KW, Cummings BP. 14-3-3-zeta mediates GLP-1 receptor agonist action to alter α cell proglucagon processing. SCIENCE ADVANCES 2022; 8:eabn3773. [PMID: 35867787 PMCID: PMC9307243 DOI: 10.1126/sciadv.abn3773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
Recent studies demonstrate that α cells contribute to glucose-stimulated insulin secretion (GSIS). Glucagon-like peptide-1 receptor (GLP-1R) agonists potently potentiate GSIS, making these drugs useful for diabetes treatment. However, the role of α and β cell paracrine interactions in the effects of GLP-1R agonists is undefined. We previously found that increased β cell GLP-1R signaling activates α cell GLP-1 expression. Here, we characterized the bidirectional paracrine cross-talk by which α and β cells communicate to mediate the effects of the GLP-1R agonist, liraglutide. We find that the effect of liraglutide to enhance GSIS is blunted by α cell ablation in male mice. Furthermore, the effect of β cell GLP-1R signaling to activate α cell GLP-1 is mediated by a secreted protein factor that is regulated by the signaling protein, 14-3-3-zeta, in mouse and human islets. These data refine our understanding of GLP-1 pharmacology and identify 14-3-3-zeta as a potential target to enhance α cell GLP-1 production.
Collapse
Affiliation(s)
- Marlena M. Holter
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Daryl J. Phuong
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Isaac Lee
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Mridusmita Saikia
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Ithaca, NY, USA
| | - Lisa Weikert
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Samantha Fountain
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
| | - Elizabeth T. Anderson
- Proteomics and Metabolomics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY, USA
| | - Qin Fu
- Proteomics and Metabolomics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY, USA
| | - Sheng Zhang
- Proteomics and Metabolomics Facility, Institute of Biotechnology, Cornell University, Ithaca, NY, USA
| | - Kyle W. Sloop
- Diabetes and Complications, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Bethany P. Cummings
- Department of Biomedical Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
- Department of Surgery, Center for Alimentary and Metabolic Sciences, School of Medicine, University of California, Davis, Sacramento, CA, USA
| |
Collapse
|
16
|
Qiao L, Saget S, Lu C, Zang T, Dzyuba B, Hay WW, Shao J. The Essential Role of Pancreatic α-Cells in Maternal Metabolic Adaptation to Pregnancy. Diabetes 2022; 71:978-988. [PMID: 35147704 PMCID: PMC9044124 DOI: 10.2337/db21-0923] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 02/07/2022] [Indexed: 11/13/2022]
Abstract
Pancreatic α-cells are important in maintaining metabolic homeostasis, but their role in regulating maternal metabolic adaptations to pregnancy has not been studied. The objective of this study was to determine whether pancreatic α-cells respond to pregnancy and their contribution to maternal metabolic adaptation. With use of C57BL/6 mice, the findings of our study showed that pregnancy induced a significant increase of α-cell mass by promoting α-cell proliferation that was associated with a transitory increase of maternal serum glucagon concentration in early pregnancy. Maternal pancreatic GLP-1 content also was significantly increased during pregnancy. Using the inducible Cre/loxp technique, we ablated the α-cells (α-null) before and during pregnancy while maintaining enteroendocrine L-cells and serum GLP-1 in the normal range. In contrast to an improved glucose tolerance test (GTT) before pregnancy, significantly impaired GTT and remarkably higher serum glucose concentrations in the fed state were observed in α-null dams. Glucagon receptor antagonism treatment, however, did not affect measures of maternal glucose metabolism, indicating a dispensable role of glucagon receptor signaling in maternal glucose homeostasis. However, the GLP-1 receptor agonist improved insulin production and glucose metabolism of α-null dams. Furthermore, GLP-1 receptor antagonist Exendin (9-39) attenuated pregnancy-enhanced insulin secretion and GLP-1 restored glucose-induced insulin secretion of cultured islets from α-null dams. Together, these results demonstrate that α-cells play an essential role in controlling maternal metabolic adaptation to pregnancy by enhancing insulin secretion.
Collapse
Affiliation(s)
- Liping Qiao
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Sarah Saget
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Cindy Lu
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Tianyi Zang
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | - Brianna Dzyuba
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
| | | | - Jianhua Shao
- Department of Pediatrics, University of California, San Diego, La Jolla, CA
- Corresponding author: Jianhua Shao,
| |
Collapse
|
17
|
Seino Y, Yamazaki Y. Roles of Glucose-Dependent Insulinotropic Polypeptide in Diet-Induced Obesity. J Diabetes Investig 2022; 13:1122-1128. [PMID: 35452190 PMCID: PMC9248429 DOI: 10.1111/jdi.13816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/08/2022] [Accepted: 04/18/2022] [Indexed: 11/28/2022] Open
Abstract
Glucose‐dependent insulinotropic polypeptide (GIP) and glucagon‐like peptide‐1 (GLP‐1) are incretins that play an important role in glucose metabolism, by increasing glucose‐induced insulin secretion from pancreatic β‐cells and help regulate bodyweight. Although they show a similar action on glucose‐induced insulin secretion, two incretins are distinct in various aspects. GIP is secreted from enteroendocrine K cell mainly expressed in the upper small intestine, and GLP‐1 is secreted from enteroendocrine L cells mainly expressed in the lower small intestine and colon by the stimulation of various nutrients. The mechanism of GIP secretion induced by nutrients, especially carbohydrates, is different from that of GLP‐1 secretion. GIP promotes fat deposition in adipose tissue, and contributes to fat‐induced obesity. In contrast, GLP‐1 participates in reducing bodyweight by suppressing food consumption and/or slowing gastric emptying. There is substantial evidence that GIP and GLP‐1 might differently contribute to bodyweight control. Although meal contents influence both glycemic and weight control, we do not fully understand whether incretin actions differ depending on the contents of the meal and what kind of signaling is involved in its context. We focus on the molecular mechanism of GIP secretion induced by nutrients, as well as the roles of GIP in weight changes caused by various diets.
Collapse
Affiliation(s)
- Yusuke Seino
- Department of Endocrinology, Diabetes and Metabolism, Fujita Health University, Toyoake, Japan
| | - Yuji Yamazaki
- Yutaka Seino Distinguished Center for Diabetes Research, Kansai Electric Power Medical Research Institute, Kobe, Japan.,Center for Diabetes, Endocrinology and Metabolism, Kansai Electric Power Hospital, Osaka, Japan
| |
Collapse
|
18
|
Esser N, Mongovin SM, Parilla J, Barrow BM, Mundinger TO, Fountaine BS, Larmore MJ, Castillo JJ, Akter R, Hull RL, Zraika S. Neprilysin inhibition improves intravenous but not oral glucose-mediated insulin secretion via GLP-1R signaling in mice with β-cell dysfunction. Am J Physiol Endocrinol Metab 2022; 322:E307-E318. [PMID: 35128957 PMCID: PMC8917916 DOI: 10.1152/ajpendo.00234.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Type 2 diabetes is associated with the upregulation of neprilysin, a peptidase capable of cleaving glucoregulatory peptides such as glucagon-like peptide-1 (GLP-1). In humans, use of the neprilysin inhibitor sacubitril in combination with an angiotensin II receptor blocker was associated with increased plasma GLP-1 levels and improved glycemic control. Whether neprilysin inhibition per se is mediating these effects remains unknown. We sought to determine whether pharmacological neprilysin inhibition on its own confers beneficial effects on glycemic status and β-cell function in a mouse model of reduced insulin secretion, and whether any such effects are dependent on GLP-1 receptor (GLP-1R) signaling. High-fat-fed male wild-type (Glp1r+/+) and GLP-1R knockout (Glp1r-/-) mice were treated with low-dose streptozotocin (STZ) to recapitulate type 2 diabetes-associated β-cell dysfunction, or vehicle as control. Mice were continued on high-fat diet alone or supplemented with the neprilysin inhibitor sacubitril for 8 wk. At the end of the study period, β-cell function was assessed by oral or intravenous glucose-tolerance test. Fasting and fed glucose were significantly lower in wild-type mice treated with sacubitril, although active GLP-1 levels and insulin secretion during oral glucose challenge were unchanged. In contrast, insulin secretion in response to intravenous glucose was significantly enhanced in sacubitril-treated wild-type mice, and this effect was blunted in Glp1r-/- mice. Similarly, sacubitril enhanced insulin secretion in vitro in islets from STZ-treated Glp1r+/+ but not Glp1r-/- mice. Together, our data suggest the insulinotropic effects of pharmacological neprilysin inhibition in a mouse model of β-cell dysfunction are mediated via intra-islet GLP-1R signaling.NEW & NOTEWORTHY The neprilysin inhibitor, sacubitril, improves glycemic status in a mouse model of reduced insulin secretion. Sacubitril enhances intravenous but not oral glucose-mediated insulin secretion. The increased glucose-mediated insulin secretion is GLP-1 receptor-dependent. Neprilysin inhibition does not raise postprandial circulating active GLP-1 levels.
Collapse
Affiliation(s)
- Nathalie Esser
- Veterans Affairs Puget Sound Health Care System, Seattle, Washington
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, Washington
- Laboratory of Immunometabolism and Nutrition, GIGA-I3, University of Liège, Liège, Belgium
| | | | - Jacqueline Parilla
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, Washington
| | - Breanne M Barrow
- Veterans Affairs Puget Sound Health Care System, Seattle, Washington
| | - Thomas O Mundinger
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, Washington
| | | | - Megan J Larmore
- Department of Comparative Medicine, University of Washington, Seattle, Washington
| | - Joseph J Castillo
- Veterans Affairs Puget Sound Health Care System, Seattle, Washington
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, Washington
| | - Rehana Akter
- Veterans Affairs Puget Sound Health Care System, Seattle, Washington
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, Washington
| | - Rebecca L Hull
- Veterans Affairs Puget Sound Health Care System, Seattle, Washington
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, Washington
| | - Sakeneh Zraika
- Veterans Affairs Puget Sound Health Care System, Seattle, Washington
- Division of Metabolism, Endocrinology & Nutrition, Department of Medicine, University of Washington, Seattle, Washington
| |
Collapse
|
19
|
Ghila L, Furuyama K, Grey ST, Scholz H, Chera S. Editorial: Beta-Cell Fate: From Gene Circuits to Disease Mechanisms. Front Genet 2022; 13:822440. [PMID: 35281817 PMCID: PMC8914033 DOI: 10.3389/fgene.2022.822440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/04/2022] [Indexed: 12/02/2022] Open
Affiliation(s)
- Luiza Ghila
- Center for Diabetes Research, Department of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
- *Correspondence: Luiza Ghila, ; Simona Chera,
| | - Kenichiro Furuyama
- Center for iPS Cell Research and Application (CiRA), Kyoto University, Kyoto, Japan
| | - Shane T. Grey
- Immunology Department, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
- Faculty of Medicine, St Vincent’s Clinical School, University of New South Wales Sydney, Sydney, NSW, Australia
| | - Hanne Scholz
- Hybrid Technology Hub-Centre of Excellence, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Transplant Medicine and Institute for Surgical Research, Oslo University Hospital, Oslo, Norway
| | - Simona Chera
- Center for Diabetes Research, Department of Clinical Science, Faculty of Medicine, University of Bergen, Bergen, Norway
- *Correspondence: Luiza Ghila, ; Simona Chera,
| |
Collapse
|
20
|
Cabrera O, Ficorilli J, Shaw J, Echeverri F, Schwede F, Chepurny OG, Leech CA, Holz GG. Intra-islet glucagon confers β-cell glucose competence for first-phase insulin secretion and favors GLP-1R stimulation by exogenous glucagon. J Biol Chem 2022; 298:101484. [PMID: 34896391 PMCID: PMC8789663 DOI: 10.1016/j.jbc.2021.101484] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 12/07/2021] [Accepted: 12/07/2021] [Indexed: 02/07/2023] Open
Abstract
We report that intra-islet glucagon secreted from α-cells signals through β-cell glucagon and GLP-1 receptors (GcgR and GLP-1R), thereby conferring to rat islets their competence to exhibit first-phase glucose-stimulated insulin secretion (GSIS). Thus, in islets not treated with exogenous glucagon or GLP-1, first-phase GSIS is abolished by a GcgR antagonist (LY2786890) or a GLP-1R antagonist (Ex[9-39]). Mechanistically, glucose competence in response to intra-islet glucagon is conditional on β-cell cAMP signaling because it is blocked by the cAMP antagonist prodrug Rp-8-Br-cAMPS-pAB. In its role as a paracrine hormone, intra-islet glucagon binds with high affinity to the GcgR, while also exerting a "spillover" effect to bind with low affinity to the GLP-1R. This produces a right shift of the concentration-response relationship for the potentiation of GSIS by exogenous glucagon. Thus, 0.3 nM glucagon fails to potentiate GSIS, as expected if similar concentrations of intra-islet glucagon already occupy the GcgR. However, 10 to 30 nM glucagon effectively engages the β-cell GLP-1R to potentiate GSIS, an action blocked by Ex[9-39] but not LY2786890. Finally, we report that the action of intra-islet glucagon to support insulin secretion requires a step-wise increase of glucose concentration to trigger first-phase GSIS. It is not measurable when GSIS is stimulated by a gradient of increasing glucose concentrations, as occurs during an oral glucose tolerance test in vivo. Collectively, such findings are understandable if defective intra-islet glucagon action contributes to the characteristic loss of first-phase GSIS in an intravenous glucose tolerance test that is diagnostic of type 2 diabetes in the clinical setting.
Collapse
Affiliation(s)
- Over Cabrera
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA.
| | - James Ficorilli
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | - Janice Shaw
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana, USA
| | | | - Frank Schwede
- Biolog Life Science Institute GmbH & Co KG, Bremen, Germany
| | - Oleg G Chepurny
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, Syracuse, New York, USA
| | - Colin A Leech
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, Syracuse, New York, USA
| | - George G Holz
- Department of Medicine, State University of New York (SUNY) Upstate Medical University, Syracuse, New York, USA; Department of Pharmacology, State University of New York (SUNY) Upstate Medical University, Syracuse, New York, USA.
| |
Collapse
|
21
|
Rohm TV, Meier DT, Olefsky JM, Donath MY. Inflammation in obesity, diabetes, and related disorders. Immunity 2022; 55:31-55. [PMID: 35021057 PMCID: PMC8773457 DOI: 10.1016/j.immuni.2021.12.013] [Citation(s) in RCA: 462] [Impact Index Per Article: 231.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 12/13/2021] [Accepted: 12/17/2021] [Indexed: 01/13/2023]
Abstract
Obesity leads to chronic, systemic inflammation and can lead to insulin resistance (IR), β-cell dysfunction, and ultimately type 2 diabetes (T2D). This chronic inflammatory state contributes to long-term complications of diabetes, including non-alcoholic fatty liver disease (NAFLD), retinopathy, cardiovascular disease, and nephropathy, and may underlie the association of type 2 diabetes with other conditions such as Alzheimer's disease, polycystic ovarian syndrome, gout, and rheumatoid arthritis. Here, we review the current understanding of the mechanisms underlying inflammation in obesity, T2D, and related disorders. We discuss how chronic tissue inflammation results in IR, impaired insulin secretion, glucose intolerance, and T2D and review the effect of inflammation on diabetic complications and on the relationship between T2D and other pathologies. In this context, we discuss current therapeutic options for the treatment of metabolic disease, advances in the clinic and the potential of immune-modulatory approaches.
Collapse
Affiliation(s)
- Theresa V. Rohm
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniel T. Meier
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, CH-4031 Basel, Switzerland.,Department of Biomedicine (DBM), University of Basel, University Hospital Basel, CH-4031 Basel, Switzerland
| | - Jerrold M. Olefsky
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Marc Y. Donath
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, CH-4031 Basel, Switzerland.,Department of Biomedicine (DBM), University of Basel, University Hospital Basel, CH-4031 Basel, Switzerland.,Correspondence:
| |
Collapse
|
22
|
Holter MM, Saikia M, Cummings BP. Alpha-cell paracrine signaling in the regulation of beta-cell insulin secretion. Front Endocrinol (Lausanne) 2022; 13:934775. [PMID: 35957816 PMCID: PMC9360487 DOI: 10.3389/fendo.2022.934775] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 06/28/2022] [Indexed: 01/14/2023] Open
Abstract
As an incretin hormone, glucagon-like peptide 1 (GLP-1) lowers blood glucose levels by enhancing glucose-stimulated insulin secretion from pancreatic beta-cells. Therapies targeting the GLP-1 receptor (GLP-1R) use the classical incretin model as a physiological framework in which GLP-1 secreted from enteroendocrine L-cells acts on the beta-cell GLP-1R. However, this model has come into question, as evidence demonstrating local, intra-islet GLP-1 production has advanced the competing hypothesis that the incretin activity of GLP-1 may reflect paracrine signaling of GLP-1 from alpha-cells on GLP-1Rs on beta-cells. Additionally, recent studies suggest that alpha-cell-derived glucagon can serve as an additional, albeit less potent, ligand for the beta-cell GLP-1R, thereby expanding the role of alpha-cells beyond that of a counterregulatory cell type. Efforts to understand the role of the alpha-cell in the regulation of islet function have revealed both transcriptional and functional heterogeneity within the alpha-cell population. Further analysis of this heterogeneity suggests that functionally distinct alpha-cell subpopulations display alterations in islet hormone profile. Thus, the role of the alpha-cell in glucose homeostasis has evolved in recent years, such that alpha-cell to beta-cell communication now presents a critical axis regulating the functional capacity of beta-cells. Herein, we describe and integrate recent advances in our understanding of the impact of alpha-cell paracrine signaling on insulin secretory dynamics and how this intra-islet crosstalk more broadly contributes to whole-body glucose regulation in health and under metabolic stress. Moreover, we explore how these conceptual changes in our understanding of intra-islet GLP-1 biology may impact our understanding of the mechanisms of incretin-based therapeutics.
Collapse
Affiliation(s)
- Marlena M. Holter
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
- *Correspondence: Marlena M. Holter,
| | - Mridusmita Saikia
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, United States
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States
| | - Bethany P. Cummings
- School of Medicine, Department of Surgery, Center for Alimentary and Metabolic Sciences, University of California, Davis, Sacramento, CA, United States
| |
Collapse
|
23
|
Panzer JK, Caicedo A. Targeting the Pancreatic α-Cell to Prevent Hypoglycemia in Type 1 Diabetes. Diabetes 2021; 70:2721-2732. [PMID: 34872936 PMCID: PMC8660986 DOI: 10.2337/dbi20-0048] [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: 05/15/2021] [Accepted: 09/08/2021] [Indexed: 12/18/2022]
Abstract
Life-threatening hypoglycemia is a limiting factor in the management of type 1 diabetes. People with diabetes are prone to develop hypoglycemia because they lose physiological mechanisms that prevent plasma glucose levels from falling. Among these so-called counterregulatory responses, secretion of glucagon from pancreatic α-cells is preeminent. Glucagon, a hormone secreted in response to a lowering in glucose concentration, counteracts a further drop in glycemia by promoting gluconeogenesis and glycogenolysis in target tissues. In diabetes, however, α-cells do not respond appropriately to changes in glycemia and, thus, cannot mount a counterregulatory response. If the α-cell could be targeted therapeutically to restore its ability to prevent hypoglycemia, type 1 diabetes could be managed more efficiently and safely. Unfortunately, the mechanisms that allow the α-cell to respond to hypoglycemia have not been fully elucidated. We know even less about the pathophysiological mechanisms that cause α-cell dysfunction in diabetes. Based on published findings and unpublished observations, and taking into account its electrophysiological properties, we propose here a model of α-cell function that could explain its impairment in diabetes. Within this frame, we emphasize those elements that could be targeted pharmacologically with repurposed U.S. Food and Drug Administration-approved drugs to rescue α-cell function and restore glucose counterregulation in people with diabetes.
Collapse
Affiliation(s)
- Julia K Panzer
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
| | - Alejandro Caicedo
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL
- Program in Neuroscience, University of Miami Miller School of Medicine, Miami, FL
| |
Collapse
|
24
|
Dos Santos T, Galipeau M, Schukarucha Gomes A, Greenberg M, Larsen M, Lee D, Maghera J, Mulchandani CM, Patton M, Perera I, Polishevska K, Ramdass S, Shayeganpour K, Vafaeian K, Van Allen K, Wang Y, Weisz T, Estall JL, Mulvihill EE, Screaton RA. Islet Biology during COVID-19: Progress and Perspectives. Can J Diabetes 2021; 46:419-427. [PMID: 35589534 PMCID: PMC8608413 DOI: 10.1016/j.jcjd.2021.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/28/2021] [Accepted: 11/01/2021] [Indexed: 01/08/2023]
Abstract
The coronavirus-2019 (COVID-19) pandemic has had significant impact on research directions and productivity in the past 2 years. Despite these challenges, since 2020, more than 2,500 peer-reviewed articles have been published on pancreatic islet biology. These include updates on the roles of isocitrate dehydrogenase, pyruvate kinase and incretin hormones in insulin secretion, as well as the discovery of inceptor and signalling by circulating RNAs. The year 2020 also brought advancements in in vivo and in vitro models, including a new transgenic mouse for assessing beta-cell proliferation, a “pancreas-on-a-chip” to study glucose-stimulated insulin secretion and successful genetic editing of primary human islet cells. Islet biologists evaluated the functionality of stem-cell–derived islet-like cells coated with semipermeable biomaterials to prevent autoimmune attack, revealing the importance of cell maturation after transplantation. Prompted by observations that COVID-19 symptoms can worsen for people with obesity or diabetes, researchers examined how islets are directly affected by severe acute respiratory syndrome coronavirus 2. Herein, we highlight novel functional insights, technologies and therapeutic approaches that emerged between March 2020 and July 2021, written for both scientific and lay audiences. We also include a response to these advancements from patient stakeholders, to help lend a broader perspective to developments and challenges in islet research.
Collapse
Affiliation(s)
- Theodore Dos Santos
- Alberta Diabetes Institute & Department of Pharmacology, Li Ka Shing Centre for Health Research Innovation, University of Alberta, Edmonton, Alberta, Canada
| | - Maria Galipeau
- Department of Molecular Biology, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada; Institut de recherches cliniques de Montréal, Cardiometabolic Disease Centre, Montréal, Québec, Canada
| | - Amanda Schukarucha Gomes
- Alberta Diabetes Institute & Department of Pharmacology, Li Ka Shing Centre for Health Research Innovation, University of Alberta, Edmonton, Alberta, Canada
| | | | | | - Daniel Lee
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta, Canada
| | - Jasmine Maghera
- Alberta Diabetes Institute & Department of Pharmacology, Li Ka Shing Centre for Health Research Innovation, University of Alberta, Edmonton, Alberta, Canada
| | | | - Megan Patton
- Toronto General Hospital, Toronto, Ontario, Canada
| | - Ineli Perera
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | - Kateryna Polishevska
- Alberta Diabetes Institute and Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | | | - Kasra Shayeganpour
- Alberta Diabetes Institute and Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | | | - Kyle Van Allen
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, Ontario, Canada
| | - Yufeng Wang
- University Health Network, Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Tom Weisz
- Toronto General Hospital, Toronto, Ontario, Canada
| | - Jennifer L Estall
- Department of Molecular Biology, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada; Institut de recherches cliniques de Montréal, Cardiometabolic Disease Centre, Montréal, Québec, Canada
| | - Erin E Mulvihill
- Energy Substrate Laboratory, University of Ottawa Heart Institute, Ottawa, Ontario, Canada; Department of Biochemistry, Immunology and Microbiology, University of Ottawa, Ottawa, Ontario, Canada
| | - Robert A Screaton
- Sunnybrook Research Institute, Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
25
|
Guo X, Cui C, Song J, He Q, Zang N, Hu H, Wang X, Li D, Wang C, Hou X, Li X, Liang K, Yan F, Chen L. Mof acetyltransferase inhibition ameliorates glucose intolerance and islet dysfunction of type 2 diabetes via targeting pancreatic α-cells. Mol Cell Endocrinol 2021; 537:111425. [PMID: 34391847 DOI: 10.1016/j.mce.2021.111425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/10/2021] [Accepted: 08/12/2021] [Indexed: 01/04/2023]
Abstract
BACKGROUND Previously, we reported that Mof was highly expressed in α-cells, and its knockdown led to ameliorated fasting blood glucose (FBG) and glucose tolerance in non-diabetic mice, attributed by reduced total α-cell but enhanced prohormone convertase (PC)1/3-positive α-cell mass. However, how Mof and histone 4 lysine 16 acetylation (H4K16ac) control α-cell and whether Mof inhibition improves glucose handling in type 2 diabetes (T2DM) mice remain unknown. METHODS Mof overexpression and chromatin immunoprecipitation sequence (ChIP-seq) based on H4K16ac were applied to determine the effect of Mof on α-cell transcriptional factors and underlying mechanism. Then we administrated mg149 to α-TC1-6 cell line, wild type, db/db and diet-induced obesity (DIO) mice to observe the impact of Mof inhibition in vitro and in vivo. In vitro, western blotting and TUNEL staining were used to examine α-cell apoptosis and function. In vivo, glucose tolerance, hormone levels, islet population, α-cell ratio and the co-staining of glucagon and PC1/3 or PC2 were examined. RESULTS Mof activated α-cell-specific transcriptional network. ChIP-seq results indicated that H4K16ac targeted essential genes regulating α-cell differentiation and function. Mof activity inhibition in vitro caused impaired α-cell function and enhanced apoptosis. In vivo, it contributed to ameliorated glucose intolerance and islet dysfunction, characterized by decreased fasting glucagon and elevated post-challenge insulin levels in T2DM mice. CONCLUSION Mof regulates α-cell differentiation and function via acetylating H4K16ac and H4K16ac binding to Pax6 and Foxa2 promoters. Mof inhibition may be a potential interventional target for T2DM, which led to decreased α-cell ratio but increased PC1/3-positive α-cells.
Collapse
Affiliation(s)
- Xinghong Guo
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Chen Cui
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Jia Song
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Qin He
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Nan Zang
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Huiqing Hu
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Xiaojie Wang
- Department of Pharmacology, Basic Medicine School of Shandong University, Jinan, 250012, Shandong, China
| | - Danyang Li
- Department of Rehabilitation, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Chuan Wang
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Xinguo Hou
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China
| | - Xiangzhi Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Life Science School of Shandong University, Qingdao, 266237, Shandong, China
| | - Kai Liang
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan, 250012, Shandong, China; Jinan Clinical Research Center for Endocrine and Metabolic Disease, Jinan, 250012, Shandong, China
| | - Fei Yan
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan, 250012, Shandong, China; Jinan Clinical Research Center for Endocrine and Metabolic Disease, Jinan, 250012, Shandong, China.
| | - Li Chen
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan, 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan, 250012, Shandong, China; Jinan Clinical Research Center for Endocrine and Metabolic Disease, Jinan, 250012, Shandong, China.
| |
Collapse
|
26
|
Bethea M, Bozadjieva-Kramer N, Sandoval DA. Preproglucagon Products and Their Respective Roles Regulating Insulin Secretion. Endocrinology 2021; 162:6329397. [PMID: 34318874 PMCID: PMC8375443 DOI: 10.1210/endocr/bqab150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Indexed: 11/19/2022]
Abstract
Historically, intracellular function and metabolic adaptation within the α-cell has been understudied, with most of the attention being placed on the insulin-producing β-cells due to their role in the pathophysiology of type 2 diabetes mellitus. However, there is a growing interest in understanding the function of other endocrine cell types within the islet and their paracrine role in regulating insulin secretion. For example, there is greater appreciation for α-cell products and their contributions to overall glucose homeostasis. Several recent studies have addressed a paracrine role for α-cell-derived glucagon-like peptide-1 (GLP-1) in regulating glucose homeostasis and responses to metabolic stress. Further, other studies have demonstrated the ability of glucagon to impact insulin secretion by acting through the GLP-1 receptor. These studies challenge the central dogma surrounding α-cell biology describing glucagon's primary role in glucose counterregulation to one where glucagon is critical in regulating both hyper- and hypoglycemic responses. Herein, this review will update the current understanding of the role of glucagon and α-cell-derived GLP-1, placing emphasis on their roles in regulating glucose homeostasis, insulin secretion, and β-cell mass.
Collapse
Affiliation(s)
- Maigen Bethea
- Department of Pediatrics, Nutrition Section, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Division of Endocrinology, Metabolism, and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | | | - Darleen A Sandoval
- Department of Pediatrics, Nutrition Section, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Division of Endocrinology, Metabolism, and Diabetes, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Correspondence: Darleen A. Sandoval, PhD, University of Colorado Anschut, Division of Endocrinology, Metabolism, and Diabetes,12801 E 17th Ave. Research Complex 1 South 7th Floor, Aurora, CO 80045, USA. E-mail:
| |
Collapse
|
27
|
Zhang Y, Han C, Zhu W, Yang G, Peng X, Mehta S, Zhang J, Chen L, Liu Y. Glucagon Potentiates Insulin Secretion Via β-Cell GCGR at Physiological Concentrations of Glucose. Cells 2021; 10:cells10092495. [PMID: 34572144 PMCID: PMC8471175 DOI: 10.3390/cells10092495] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 12/21/2022] Open
Abstract
Incretin-potentiated glucose-stimulated insulin secretion (GSIS) is critical to maintaining euglycemia, of which GLP-1 receptor (GLP-1R) on β-cells plays an indispensable role. Recently, α-cell-derived glucagon but not intestine-derived GLP-1 has been proposed as the critical hormone that potentiates GSIS via GLP-1R. However, the function of glucagon receptors (GCGR) on β-cells remains elusive. Here, using GCGR or GLP-1R antagonists, in combination with glucagon, to treat single β-cells, α-β cell clusters and isolated islets, we found that glucagon potentiates insulin secretion via β-cell GCGR at physiological but not high concentrations of glucose. Furthermore, we transfected primary mouse β-cells with RAB-ICUE (a genetically encoded cAMP fluorescence indicator) to monitor cAMP level after glucose stimulation and GCGR activation. Using specific inhibitors of different adenylyl cyclase (AC) family members, we revealed that high glucose concentration or GCGR activation independently evoked cAMP elevation via AC5 in β-cells, thus high glucose stimulation bypassed GCGR in promoting insulin secretion. Additionally, we generated β-cell-specific GCGR knockout mice which glucose intolerance was more severe when fed a high-fat diet (HFD). We further found that β-cell GCGR activation promoted GSIS more than GLP-1R in HFD, indicating the critical role of GCGR in maintaining glucose homeostasis during nutrient overload.
Collapse
Affiliation(s)
- Yulin Zhang
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Chengsheng Han
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Wenzhen Zhu
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Guoyi Yang
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Xiaohong Peng
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
| | - Sohum Mehta
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0702, USA; (S.M.); (J.Z.)
| | - Jin Zhang
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093-0702, USA; (S.M.); (J.Z.)
| | - Liangyi Chen
- State Key Laboratory of Membrane Biology, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Institute of Molecular Medicine, College of Future Technology, Peking University, Beijing 100871, China; (Y.Z.); (C.H.); (W.Z.); (G.Y.); (X.P.)
- PKU-IDG/McGovern Institute for Brain Research, Beijing 100871, China
- Beijing Academy of Artificial Intelligence, Beijing 100871, China
- Correspondence: (L.C.); (Y.L.)
| | - Yanmei Liu
- Key Laboratory of Brain, Cognition and Education Sciences, Ministry of Education, Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou 510631, China
- Correspondence: (L.C.); (Y.L.)
| |
Collapse
|
28
|
Fischer KL, Jaffredo M, Lang J, Raoux M. [Pancreatic α and β cells: Best enemies or partners for life?]. Med Sci (Paris) 2021; 37:752-758. [PMID: 34491183 DOI: 10.1051/medsci/2021111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Diabetes are major metabolic diseases constantly increasing in the population, caused by reduced secretion and action of insulin, the only hormone lowering efficiently the glycaemia. Insulin is secreted by β cells within the pancreatic islets of Langerhans. The islet micro-organs also contain 15 to 35% of α cells, well-known for their opposite effects on glycaemia. Considered until now as potentially harmful in diabetes, α cells are emerging as potent enhancers of β cell activity when studied in physiological nutritional setting and should therefore be reconsidered in a therapeutic point of view. This review summarizes the latest concepts regarding β cell function in physiological states and the involvement of dynamic functional interactions between α and β cells for the regulation of nutrient homeostasis.
Collapse
Affiliation(s)
- Karen Leal Fischer
- Institut de chimie et de biologie des membranes et des nano-objets, CBMN, Université de Bordeaux, CNRS UMR 5248, B14 allée Geoffroy Saint Hilaire, F-33600, Pessac, France
| | - Manon Jaffredo
- Institut de chimie et de biologie des membranes et des nano-objets, CBMN, Université de Bordeaux, CNRS UMR 5248, B14 allée Geoffroy Saint Hilaire, F-33600, Pessac, France
| | - Jochen Lang
- Institut de chimie et de biologie des membranes et des nano-objets, CBMN, Université de Bordeaux, CNRS UMR 5248, B14 allée Geoffroy Saint Hilaire, F-33600, Pessac, France
| | - Matthieu Raoux
- Institut de chimie et de biologie des membranes et des nano-objets, CBMN, Université de Bordeaux, CNRS UMR 5248, B14 allée Geoffroy Saint Hilaire, F-33600, Pessac, France
| |
Collapse
|
29
|
Galvin SG, Kay RG, Foreman R, Larraufie P, Meek CL, Biggs E, Ravn P, Jermutus L, Reimann F, Gribble FM. The Human and Mouse Islet Peptidome: Effects of Obesity and Type 2 Diabetes, and Assessment of Intraislet Production of Glucagon-like Peptide-1. J Proteome Res 2021; 20:4507-4517. [PMID: 34423991 PMCID: PMC8419866 DOI: 10.1021/acs.jproteome.1c00463] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Indexed: 02/07/2023]
Abstract
To characterize the impact of metabolic disease on the peptidome of human and mouse pancreatic islets, LC-MS was used to analyze extracts of human and mouse islets, purified mouse alpha, beta, and delta cells, supernatants from mouse islet incubations, and plasma from patients with type 2 diabetes. Islets were obtained from healthy and type 2 diabetic human donors, and mice on chow or high fat diet. All major islet hormones were detected in lysed islets as well as numerous peptides from vesicular proteins including granins and processing enzymes. Glucose-dependent insulinotropic peptide (GIP) was not detectable. High fat diet modestly increased islet content of proinsulin-derived peptides in mice. Human diabetic islets contained increased content of proglucagon-derived peptides at the expense of insulin, but no evident prohormone processing defects. Diabetic plasma, however, contained increased ratios of proinsulin and des-31,32-proinsulin to insulin. Active GLP-1 was detectable in human and mouse islets but 100-1000-fold less abundant than glucagon. LC-MS offers advantages over antibody-based approaches for identifying exact peptide sequences, and revealed a shift toward islet insulin production in high fat fed mice, and toward proglucagon production in type 2 diabetes, with no evidence of systematic defective prohormone processing.
Collapse
Affiliation(s)
- Sam G. Galvin
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Richard G. Kay
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Rachel Foreman
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Pierre Larraufie
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Claire L. Meek
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Emma Biggs
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Peter Ravn
- Research
and Early Development Cardiovascular, Renal and Metabolism (CVRM),
BioPharmaceuticals R&D, AstraZeneca
Ltd., Cambridge, CB21 6GH, U.K.
| | - Lutz Jermutus
- Research
and Early Development Cardiovascular, Renal and Metabolism (CVRM),
BioPharmaceuticals R&D, AstraZeneca
Ltd., Cambridge, CB21 6GH, U.K.
| | - Frank Reimann
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| | - Fiona M. Gribble
- University
of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, Addenbrooke’s
Hospital, Hills Road, Cambridge, CB2 0QQ, U.K.
| |
Collapse
|
30
|
Choi H, Shinohara M, Ibuki M, Nishikawa M, Sakai Y. Differentiation of Human-Induced Pluripotent Stem Cell-Derived Endocrine Progenitors to Islet-like Cells Using a Dialysis Suspension Culture System. Cells 2021; 10:cells10082017. [PMID: 34440786 PMCID: PMC8392085 DOI: 10.3390/cells10082017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 08/01/2021] [Accepted: 08/02/2021] [Indexed: 12/01/2022] Open
Abstract
The production of functional islet-like cells from human-induced pluripotent stem cells (hiPSCs) is a promising strategy for the therapeutic use and disease modeling for type 1 diabetes. However, the production cost of islet-like cells is extremely high due to the use of expensive growth factors for differentiation. In a conventional culture method, growth factors and beneficial autocrine factors remaining in the culture medium are removed along with toxic metabolites during the medium change, and it limits the efficient utilization of those factors. In this study, we demonstrated that the dialysis suspension culture system is possible to reduce the usage of growth factors to one-third in the differentiation of hiPSC-derived endocrine progenitor cells to islet-like cells by reducing the medium change frequency with the refinement of the culture medium. Furthermore, the expression levels of hormone-secretion-related genes and the efficiency of differentiation were improved with the dialysis suspension culture system, possibly due to the retaining of autocrine factors. In addition, we confirmed several improvements required for the further study of the dialysis culture system. These findings showed the promising possibility of the dialysis suspension culture system for the low-cost production of islet-like cells.
Collapse
Affiliation(s)
- Hyunjin Choi
- Department of Bioengineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8654, Japan
- Correspondence:
| | - Marie Shinohara
- Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan; (M.S.); (M.I.)
| | - Masato Ibuki
- Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan; (M.S.); (M.I.)
- Kaneka Corporation, Osaka 530-0005, Japan
| | - Masaki Nishikawa
- Department of Chemical System Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8654, Japan; (M.N.); (Y.S.)
| | - Yasuyuki Sakai
- Department of Chemical System Engineering, Graduate School of Engineering, The University of Tokyo, Tokyo 113-8654, Japan; (M.N.); (Y.S.)
| |
Collapse
|
31
|
Ramzy A, Kieffer TJ. Altered islet prohormone processing: A cause or consequence of diabetes? Physiol Rev 2021; 102:155-208. [PMID: 34280055 DOI: 10.1152/physrev.00008.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Peptide hormones are first produced as larger precursor prohormones that require endoproteolytic cleavage to liberate the mature hormones. A structurally conserved but functionally distinct family of nine prohormone convertase enzymes (PCs) are responsible for cleavage of protein precursors of which PC1/3 and PC2 are known to be exclusive to neuroendocrine cells and responsible for prohormone cleavage. Differential expression of PCs within tissues define prohormone processing; whereas glucagon is the major product liberated from proglucagon via PC2 in pancreatic α-cells, proglucagon is preferentially processed by PC1/3 in intestinal L cells to produce glucagon-like peptides 1 and 2 (GLP-1, GLP-2). Beyond our understanding of processing of islet prohormones in healthy islets, there is convincing evidence that proinsulin, proIAPP, and proglucagon processing is altered during prediabetes and diabetes. There is predictive value of elevated circulating proinsulin or proinsulin : C-peptide ratio for progression to type 2 diabetes and elevated proinsulin or proinsulin : C-peptide is predictive for development of type 1 diabetes in at risk groups. After onset of diabetes, patients have elevated circulating proinsulin and proIAPP and proinsulin may be an autoantigen in type 1 diabetes. Further, preclinical studies reveal that α-cells have altered proglucagon processing during diabetes leading to increased GLP-1 production. We conclude that despite strong associative data, current evidence is inconclusive on the potential causal role of impaired prohormone processing in diabetes, and suggest that future work should focus on resolving the question of whether altered prohormone processing is a causal driver or merely a consequence of diabetes pathology.
Collapse
Affiliation(s)
- Adam Ramzy
- Laboratory of Molecular and Cellular Medicine, Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Timothy J Kieffer
- Laboratory of Molecular and Cellular Medicine, Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
32
|
Pancreatic β Cells Inhibit Glucagon Secretion from α Cells: An In Vitro Demonstration of α-β Cell Interaction. Nutrients 2021; 13:nu13072281. [PMID: 34209449 PMCID: PMC8308288 DOI: 10.3390/nu13072281] [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: 06/10/2021] [Revised: 06/25/2021] [Accepted: 06/27/2021] [Indexed: 12/24/2022] Open
Abstract
Interactions between endocrine α and β cells are critical to their secretory function in vivo. The interactions are highly regulated, although yet to be fully understood. In this study, we aim to assess the impact of α and β cell co-culture on hormone secretion. Mouse clonal cell lines α-TC6-1 (α cell line) and MIN-6 (β cell line) were cultured independently or in combination in a medium containing 5.5, 11.1, or 25 mM glucose, respectively. After 72 h, hormone release was measured using insulin and glucagon secretion assays, the cell distribution was visualized by inverted microscopy and an immunocytochemistry assay, and changes in gene expressions were assessed using the RT-PCR technique. The co-culture of the two cell lines caused a decrease in glucagon secretion from α-TC1-6 cells, while no effect on insulin secretion from MIN-6 cells was revealed. Both types of cells were randomly scattered throughout the culture flask, unlike in mice islets in vivo where β cells cluster in the core and α cells are localized at the periphery. During the α-β cell co-culture, the gene expression of glucagon (Gcg) decreased significantly. We conclude that islet β cells suppress glucagon secretion from α cells, apparently via direct cell-to-cell contact, of which the molecular mechanism needs further verification.
Collapse
|
33
|
Abstract
The kexin-like proprotein convertases perform the initial proteolytic cleavages that ultimately generate a variety of different mature peptide and proteins, ranging from brain neuropeptides to endocrine peptide hormones, to structural proteins, among others. In this review, we present a general introduction to proprotein convertase structure and biochemistry, followed by a comprehensive discussion of each member of the kexin-like subfamily of proprotein convertases. We summarize current knowledge of human proprotein convertase insufficiency syndromes, including genome-wide analyses of convertase polymorphisms, and compare these to convertase null and mutant mouse models. These mouse models have illuminated our understanding of the roles specific convertases play in human disease and have led to the identification of convertase-specific substrates; for example, the identification of procorin as a specific PACE4 substrate in the heart. We also discuss the limitations of mouse null models in interpreting human disease, such as differential precursor cleavage due to species-specific sequence differences, and the challenges presented by functional redundancy among convertases in attempting to assign specific cleavages and/or physiological roles. However, in most cases, knockout mouse models have added substantively both to our knowledge of diseases caused by human proprotein convertase insufficiency and to our appreciation of their normal physiological roles, as clearly seen in the case of the furin, proprotein convertase 1/3, and proprotein convertase 5/6 mouse models. The creation of more sophisticated mouse models with tissue- or temporally-restricted expression of specific convertases will improve our understanding of human proprotein convertase insufficiency and potentially provide support for the emerging concept of therapeutic inhibition of convertases.
Collapse
Affiliation(s)
- Manita Shakya
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| |
Collapse
|
34
|
Mechanisms of Beta-Cell Apoptosis in Type 2 Diabetes-Prone Situations and Potential Protection by GLP-1-Based Therapies. Int J Mol Sci 2021; 22:ijms22105303. [PMID: 34069914 PMCID: PMC8157542 DOI: 10.3390/ijms22105303] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/07/2021] [Accepted: 05/13/2021] [Indexed: 12/22/2022] Open
Abstract
Type 2 diabetes (T2D) is characterized by chronic hyperglycemia secondary to the decline of functional beta-cells and is usually accompanied by a reduced sensitivity to insulin. Whereas altered beta-cell function plays a key role in T2D onset, a decreased beta-cell mass was also reported to contribute to the pathophysiology of this metabolic disease. The decreased beta-cell mass in T2D is, at least in part, attributed to beta-cell apoptosis that is triggered by diabetogenic situations such as amyloid deposits, lipotoxicity and glucotoxicity. In this review, we discussed the molecular mechanisms involved in pancreatic beta-cell apoptosis under such diabetes-prone situations. Finally, we considered the molecular signaling pathways recruited by glucagon-like peptide-1-based therapies to potentially protect beta-cells from death under diabetogenic situations.
Collapse
|
35
|
Zeigerer A, Sekar R, Kleinert M, Nason S, Habegger KM, Müller TD. Glucagon's Metabolic Action in Health and Disease. Compr Physiol 2021; 11:1759-1783. [PMID: 33792899 PMCID: PMC8513137 DOI: 10.1002/cphy.c200013] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Discovered almost simultaneously with insulin, glucagon is a pleiotropic hormone with metabolic action that goes far beyond its classical role to increase blood glucose. Albeit best known for its ability to directly act on the liver to increase de novo glucose production and to inhibit glycogen breakdown, glucagon lowers body weight by decreasing food intake and by increasing metabolic rate. Glucagon further promotes lipolysis and lipid oxidation and has positive chronotropic and inotropic effects in the heart. Interestingly, recent decades have witnessed a remarkable renaissance of glucagon's biology with the acknowledgment that glucagon has pharmacological value beyond its classical use as rescue medication to treat severe hypoglycemia. In this article, we summarize the multifaceted nature of glucagon with a special focus on its hepatic action and discuss the pharmacological potential of either agonizing or antagonizing the glucagon receptor for health and disease. © 2021 American Physiological Society. Compr Physiol 11:1759-1783, 2021.
Collapse
Affiliation(s)
- Anja Zeigerer
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Revathi Sekar
- Institute for Diabetes and Cancer, Helmholtz Center Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Maximilian Kleinert
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Shelly Nason
- Comprehensive Diabetes Center, Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Kirk M. Habegger
- Comprehensive Diabetes Center, Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Timo D. Müller
- German Center for Diabetes Research (DZD), Neuherberg, Germany
- Institute for Diabetes and Obesity, Helmholtz Center Munich, Neuherberg, Germany
- Department of Pharmacology, Experimental Therapy and Toxicology, Institute of Experimental and Clinical Pharmacology and Pharmacogenomics, Eberhard Karls University Hospitals and Clinics, Tübingen, Germany
| |
Collapse
|
36
|
McLean BA, Wong CK, Campbell JE, Hodson DJ, Trapp S, Drucker DJ. Revisiting the Complexity of GLP-1 Action from Sites of Synthesis to Receptor Activation. Endocr Rev 2021; 42:101-132. [PMID: 33320179 PMCID: PMC7958144 DOI: 10.1210/endrev/bnaa032] [Citation(s) in RCA: 107] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Indexed: 02/06/2023]
Abstract
Glucagon-like peptide-1 (GLP-1) is produced in gut endocrine cells and in the brain, and acts through hormonal and neural pathways to regulate islet function, satiety, and gut motility, supporting development of GLP-1 receptor (GLP-1R) agonists for the treatment of diabetes and obesity. Classic notions of GLP-1 acting as a meal-stimulated hormone from the distal gut are challenged by data supporting production of GLP-1 in the endocrine pancreas, and by the importance of brain-derived GLP-1 in the control of neural activity. Moreover, attribution of direct vs indirect actions of GLP-1 is difficult, as many tissue and cellular targets of GLP-1 action do not exhibit robust or detectable GLP-1R expression. Furthermore, reliable detection of the GLP-1R is technically challenging, highly method dependent, and subject to misinterpretation. Here we revisit the actions of GLP-1, scrutinizing key concepts supporting gut vs extra-intestinal GLP-1 synthesis and secretion. We discuss new insights refining cellular localization of GLP-1R expression and integrate recent data to refine our understanding of how and where GLP-1 acts to control inflammation, cardiovascular function, islet hormone secretion, gastric emptying, appetite, and body weight. These findings update our knowledge of cell types and mechanisms linking endogenous vs pharmacological GLP-1 action to activation of the canonical GLP-1R, and the control of metabolic activity in multiple organs.
Collapse
Affiliation(s)
- Brent A McLean
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, University of Toronto, Ontario, Canada
| | - Chi Kin Wong
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, University of Toronto, Ontario, Canada
| | - Jonathan E Campbell
- The Department of Medicine, Division of Endocrinology, Department of Pharmacology and Cancer Biology, Duke Molecular Physiology Institute, Duke University, Durham, NC, USA
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, and Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Stefan Trapp
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology & Pharmacology, UCL, London, UK
| | - Daniel J Drucker
- Department of Medicine, Lunenfeld-Tanenbaum Research Institute, Mt. Sinai Hospital, University of Toronto, Ontario, Canada
| |
Collapse
|
37
|
Abstract
Glucagon-Like Peptide-1 (GLP-1) is an important peptide hormone secreted by L-cells in the gastrointestinal tract in response to nutrients. It is produced by the differential cleavage of the proglucagon peptide. GLP-1 elicits a wide variety of physiological responses in many tissues that contribute to metabolic homeostasis. For these reasons, therapies designed to either increase endogenous GLP-1 levels or introduce exogenous peptide mimetics are now widely used in the management of diabetes. In addition to GLP-1 production from L-cells, recent reports suggest that pancreatic islet alpha cells may also synthesize and secrete GLP-1. Intra-islet GLP-1 may therefore play an unappreciated role in islet health and glucose regulation, suggesting a potential functional paracrine role for islet-derived GLP-1. In this review, we assess the current literature from an islet-centric point-of-view to better understand the production, degradation, and actions of GLP-1 within the endocrine pancreas in rodents and humans. The relevance of intra-islet GLP-1 in human physiology is discussed regarding the potential role of intra-islet GLP-1 in islet health and dysfunction.
Collapse
Affiliation(s)
- Scott A. Campbell
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montreal Diabetes Research Centre CRCHUM, Montréal, Canada
| | - Janyne Johnson
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Peter E. Light
- Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
- CONTACT Peter E. Light Alberta Diabetes Institute, Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AlbertaT6G 2E1, Canada
| |
Collapse
|
38
|
Saikia M, Holter MM, Donahue LR, Lee IS, Zheng QC, Wise JL, Todero JE, Phuong DJ, Garibay D, Coch R, Sloop KW, Garcia-Ocana A, Danko CG, Cummings BP. GLP-1 receptor signaling increases PCSK1 and β cell features in human α cells. JCI Insight 2021; 6:141851. [PMID: 33554958 PMCID: PMC7934853 DOI: 10.1172/jci.insight.141851] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/29/2020] [Indexed: 02/06/2023] Open
Abstract
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that potentiates glucose-stimulated insulin secretion. GLP-1 is classically produced by gut L cells; however, under certain circumstances α cells can express the prohormone convertase required for proglucagon processing to GLP-1, prohormone convertase 1/3 (PC1/3), and can produce GLP-1. However, the mechanisms through which this occurs are poorly defined. Understanding the mechanisms by which α cell PC1/3 expression can be activated may reveal new targets for diabetes treatment. Here, we demonstrate that the GLP-1 receptor (GLP-1R) agonist, liraglutide, increased α cell GLP-1 expression in a β cell GLP-1R-dependent manner. We demonstrate that this effect of liraglutide was translationally relevant in human islets through application of a new scRNA-seq technology, DART-Seq. We found that the effect of liraglutide to increase α cell PC1/3 mRNA expression occurred in a subcluster of α cells and was associated with increased expression of other β cell-like genes, which we confirmed by IHC. Finally, we found that the effect of liraglutide to increase bihormonal insulin+ glucagon+ cells was mediated by the β cell GLP-1R in mice. Together, our data validate a high-sensitivity method for scRNA-seq in human islets and identify a potentially novel GLP-1-mediated pathway regulating human α cell function.
Collapse
Affiliation(s)
- Mridusmita Saikia
- Department of Biomedical Sciences and
- Baker Institute for Animal Health, Cornell University College of Veterinary Medicine, Ithaca, New York, USA
| | | | | | | | | | | | | | | | | | - Reilly Coch
- Cayuga Medical Center, Ithaca, New York, USA
| | - Kyle W Sloop
- Diabetes and Complications, Lilly Research Laboratories, Lilly, Indianapolis, Indiana, USA
| | | | - Charles G Danko
- Department of Biomedical Sciences and
- Baker Institute for Animal Health, Cornell University College of Veterinary Medicine, Ithaca, New York, USA
| | | |
Collapse
|
39
|
Miyazaki S, Tashiro F, Tsuchiya T, Sasaki K, Miyazaki JI. Establishment of a long-term stable β-cell line and its application to analyze the effect of Gcg expression on insulin secretion. Sci Rep 2021; 11:477. [PMID: 33436850 PMCID: PMC7804151 DOI: 10.1038/s41598-020-79992-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 12/15/2020] [Indexed: 01/29/2023] Open
Abstract
A pancreatic β-cell line MIN6 was previously established in our lab from an insulinoma developed in an IT6 transgenic mouse expressing the SV40 T antigen in β-cells. This cell line has been widely used for in vitro analysis of β-cell function, but tends to lose the mature β-cell features, including glucose-stimulated insulin secretion (GSIS), in long-term culture. The aim of this study was to develop a stable β-cell line that retains the characteristics of mature β-cells. Considering that mice derived from a cross between C3H and C57BL/6 strains are known to exhibit higher insulin secretory capacity than C57BL/6 mice, an IT6 male mouse of this hybrid background was used to isolate insulinomas, which were independently cultured. After 7 months of continuous culturing, we obtained the MIN6-CB4 β-cell line, which stably maintains its GSIS. It has been noted that β-cell lines express the glucagon (Gcg) gene at certain levels. MIN6-CB4 cells were utilized to assess the effects of differential Gcg expression on β-cell function. Our data show the functional importance of Gcg expression and resulting basal activation of the GLP-1 receptor in β-cells. MIN6-CB4 cells can serve as an invaluable tool for studying the regulatory mechanisms of insulin secretion, such as the GLP-1/cAMP signaling, in β-cells.
Collapse
Affiliation(s)
- Satsuki Miyazaki
- grid.136593.b0000 0004 0373 3971Division of Stem Cell Regulation Research, Center for Medical Research and Education, Osaka University Graduate School of Medicine, Suita, Osaka Japan
| | - Fumi Tashiro
- grid.136593.b0000 0004 0373 3971Division of Stem Cell Regulation Research, Center for Medical Research and Education, Osaka University Graduate School of Medicine, Suita, Osaka Japan
| | - Takashi Tsuchiya
- grid.410796.d0000 0004 0378 8307National Cerebral and Cardiovascular Center, Suita, Osaka Japan
| | - Kazuki Sasaki
- grid.410796.d0000 0004 0378 8307National Cerebral and Cardiovascular Center, Suita, Osaka Japan ,grid.419521.a0000 0004 1763 8692Present Address: Sasaki Institute, 2-2, Kandasurugadai, Chiyoda-ku, Tokyo, 101-0062 Japan
| | - Jun-ichi Miyazaki
- grid.136593.b0000 0004 0373 3971The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 560-0047 Japan
| |
Collapse
|
40
|
Henquin JC. Paracrine and autocrine control of insulin secretion in human islets: evidence and pending questions. Am J Physiol Endocrinol Metab 2021; 320:E78-E86. [PMID: 33103455 DOI: 10.1152/ajpendo.00485.2020] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Insulin secretion by β-cells is largely controlled by circulating nutrients, hormones, and neurotransmitters. However, recent years have witnessed the multiplication of studies investigating whether local regulation also takes place within pancreatic islets, in which β-cells cohabit with several other cell types. The cell composition and architectural organization of human islets differ from those of rodent islets and are particularly favorable to cellular interactions. An impressive number of hormonal (glucagon, glucagon-like peptide-1, somatostatin, etc.) and nonhormonal products (ATP, acetylcholine, γ-aminobutyric acid, dopamine, etc.) are released by islet cells and have been implicated in a local control of insulin secretion. This review analyzes reports directly testing paracrine and autocrine control of insulin secretion in isolated human islets. Many of these studies were designed on background information collected in rodent islets. However, the perspective of the review is not to highlight species similarities or specificities but to contrast established and speculative mechanisms in human islets. It will be shown that the current evidence is convincing only for a minority of candidates for a paracrine function whereas arguments supporting a physiological role of others do not stand up to scrutiny. Several pending questions await further investigation.
Collapse
Affiliation(s)
- Jean-Claude Henquin
- Unit of Endocrinology and Metabolism, Faculty of Medicine, University of Louvain, Brussels, Belgium
| |
Collapse
|
41
|
Sandoval D. Updating the Role of α-Cell Preproglucagon Products on GLP-1 Receptor-Mediated Insulin Secretion. Diabetes 2020; 69:2238-2245. [PMID: 33082272 PMCID: PMC7576561 DOI: 10.2337/dbi19-0027] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 08/10/2020] [Indexed: 02/06/2023]
Abstract
While the field of islet biology has historically focused its attention on understanding β-cell function and the mechanisms by which these cells become dysfunctional with diabetes, there has been a scientific shift toward greater understanding of other endocrine cells of the islet and their paracrine role in regulating the β-cell. In recent years, many questions and new data have come forward regarding the paracrine role of the α-cell and specifically preproglucagon peptides in regulating insulin secretion. The role of intestinally secreted glucagon-like peptide 1 (GLP-1) in regulation of insulin secretion has been questioned, and a physiological role of pancreatic GLP-1 in regulation of insulin secretion has been proposed. In addition, in the last 2 years, a series of studies demonstrated a physiological role for glucagon, acting via the GLP-1 receptor, in paracrine regulation of insulin secretion. Altogether, this work challenges the textbook physiology of both GLP-1 and glucagon and presents a critical paradigm shift for the field. This article addresses these new findings surrounding α-cell preproglucagon products, with a particular focus on GLP-1, in the context of their roles in insulin secretion and consequently glucose metabolism.
Collapse
|
42
|
El K, Capozzi ME, Campbell JE. Repositioning the Alpha Cell in Postprandial Metabolism. Endocrinology 2020; 161:5910252. [PMID: 32964214 PMCID: PMC7899437 DOI: 10.1210/endocr/bqaa169] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/17/2020] [Indexed: 12/24/2022]
Abstract
Glucose homeostasis is maintained in large part due to the actions of the pancreatic islet hormones insulin and glucagon, secreted from β- and α-cells, respectively. The historical narrative positions these hormones in opposition, with insulin primarily responsible for glucose-lowering and glucagon-driving elevations in glucose. Recent progress in this area has revealed a more complex relationship between insulin and glucagon, highlighted by data demonstrating that α-cell input is essential for β-cell function and glucose homeostasis. Moreover, the common perception that glucagon levels decrease following a nutrient challenge is largely shaped by the inhibitory effects of glucose administration alone on the α-cell. Largely overlooked is that a mixed nutrient challenge, which is more representative of typical human feeding, actually stimulates glucagon secretion. Thus, postprandial metabolism is associated with elevations, not decreases, in α-cell activity. This review discusses the recent advances in our understanding of how α-cells regulate metabolism, with a particular focus on the postprandial state. We highlight α- to β-cell communication, a term that describes how α-cell input into β-cells is a critical axis that regulates insulin secretion and glucose homeostasis. Finally, we discuss the open questions that have the potential to advance this field and continue to evolve our understanding of the role that α-cells play in postprandial metabolism.
Collapse
Affiliation(s)
- Kimberley El
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
| | - Megan E Capozzi
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, Duke University, Durham, North Carolina
- Department of Pharmacology and Cancer Biology, Duke University, Durham, North Carolina
- Department of Medicine, Division of Endocrinology, Duke University, Durham, North Carolina
- Correspondence: Jonathan E. Campbell, 300 N Duke Street, Durham, North Carolina 27701. E-mail:
| |
Collapse
|
43
|
Markaki I, Winther K, Catrina SB, Svenningsson P. Repurposing GLP1 agonists for neurodegenerative diseases. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2020; 155:91-112. [PMID: 32854860 DOI: 10.1016/bs.irn.2020.02.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
There is a large unmet medical need to find disease modifying therapies against neurodegenerative diseases. This review summarizes data indicating that insulin resistance occurs in neurodegeneration and strategies to normalize insulin sensitivity in neurons may provide neuroprotective actions. In particular, recent preclinical and clinical studies in Parkinson's disease and Alzheimer's disease have indicated that glucagon-like peptide 1 (GLP1) agonism and dipeptidyl peptidase-4 inhibition may exert neuroprotection. Mechanistic insights from these studies and future directions for drug development against neurodegeneration based on GLP1 agonism are discussed.
Collapse
Affiliation(s)
- Ioanna Markaki
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Center of Neurology, Academic Specialist Center, Stockholm, Sweden.
| | - Kristian Winther
- Center of Diabetes, Academic Specialist Center, Stockholm, Sweden
| | - Sergiu-Bogdan Catrina
- Center of Diabetes, Academic Specialist Center, Stockholm, Sweden; Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Per Svenningsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Center of Neurology, Academic Specialist Center, Stockholm, Sweden; Department of Neurology, Karolinska University Hospital, Stockholm, Sweden.
| |
Collapse
|
44
|
Guo X, Li D, Song J, Yang Q, Wang M, Yang Y, Wang L, Hou X, Chen L, Li X. Mof regulates glucose level via altering different α-cell subset mass and intra-islet glucagon-like peptide-1, glucagon secretion. Metabolism 2020; 109:154290. [PMID: 32522488 DOI: 10.1016/j.metabol.2020.154290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/02/2020] [Accepted: 06/05/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Males absent on the first (Mof) is implicated in gene control of diverse biological processes, such as cell growth, differentiation, apoptosis and autophagy. However, the relationship between glucose regulation and Mof-mediated transcription events remains unexplored. We aimed to unravel the role of Mof in glucose regulation by using global and pancreatic α-cell-specific Mof-deficient mice in vivo and α-TC1-6 cell line in vitro. METHODS We used tamoxifen-induced temporal Mof-deficient mice first to show Mof regulate glucose homeostasis, islet cell proportions and hormone secretion. Then we used α-cell-specific Mof-deficient mice to clarify how α-cell subsets and β-cell mass were regulated and corresponding hormone level alterations. Ultimately, we used small interfering RNA (siRNA) to knockdown Mof in α-TC1-6 and unravel the mechanism regulating α-cell mass and glucagon secretion. RESULTS Mof was mainly expressed in α-cells. Global Mof deficiency led to lower glucose levels, attributed by decreased α/β-cell ratio and glucagon secretion. α-cell-specific Mof-deficient mice exhibited similar alterations, with more reduced prohormone convertase 2 (PC2)-positive α-cell mass, responsible for less glucagon, and enhanced prohormone convertase 1 (PC1/3)-positive α-cell mass, leading to more glucagon-like peptide-1 (GLP-1) secretion, thus increased β-cell mass and insulin secretion. In vitro, increased DNA damage, dysregulated autophagy, enhanced apoptosis and altered cell fate factors expressions upon Mof knockdown were observed. Genes and pathways linked to impaired glucagon secretion were uncovered through transcriptome sequencing. CONCLUSION Mof is a potential interventional target for glucose regulation, from the aspects of both α-cell subset mass and glucagon, intra-islet GLP-1 secretion. Upon Mof deficiency, Up-regulated PC1/3 but down-regulated PC2-positive α-cell mass, leads to more GLP-1 and insulin but less glucagon secretion, and contributed to lower glucose level.
Collapse
Affiliation(s)
- Xinghong Guo
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China; Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Danyang Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China; Department of Rehabilitation, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Jia Song
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Qibing Yang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China
| | - Meng Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China
| | - Yang Yang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China
| | - Lingshu Wang
- Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan 250012, Shandong, China
| | - Xinguo Hou
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China
| | - Li Chen
- Department of Endocrinology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250012, Shandong, China; Institute of Endocrine and Metabolic Diseases of Shandong University, Jinan 250012, Shandong, China; Key Laboratory of Endocrine and Metabolic Diseases, Shandong Province Medicine & Health, Jinan 250012, Shandong, China.
| | - Xiangzhi Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao 266237, Shandong, China.
| |
Collapse
|
45
|
Campbell SA, Golec DP, Hubert M, Johnson J, Salamon N, Barr A, MacDonald PE, Philippaert K, Light PE. Human islets contain a subpopulation of glucagon-like peptide-1 secreting α cells that is increased in type 2 diabetes. Mol Metab 2020; 39:101014. [PMID: 32413586 PMCID: PMC7260680 DOI: 10.1016/j.molmet.2020.101014] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/24/2020] [Accepted: 05/04/2020] [Indexed: 12/16/2022] Open
Abstract
Objectives Our study shows that glucagon-like peptide-1 (GLP-1) is secreted within human islets and may play an unexpectedly important paracrine role in islet physiology and pathophysiology. It is known that α cells within rodent and human pancreatic islets are capable of secreting GLP-1, but little is known about the functional role that islet-derived GLP-1 plays in human islets. Methods We used flow cytometry, immunohistochemistry, perifusions, and calcium imaging techniques to analyse GLP-1 expression and function in islets isolated from cadaveric human donors with or without type 2 diabetes. We also used immunohistochemistry to analyse GLP-1 expression within islets from pancreatic biopsies obtained from living donors. Results We have demonstrated that human islets secrete ∼50-fold more GLP-1 than murine islets and that ∼40% of the total human α cells contain GLP-1. Our results also confirm that dipeptidyl peptidase-4 (DPP4) is expressed in α cells. Sitagliptin increased GLP-1 secretion from cultured human islets but did not enhance glucose-stimulated insulin secretion (GSIS) in islets from non-diabetic (ND) or type 2 diabetic (T2D) donors, suggesting that β cell GLP-1 receptors (GLP-1R) may already be maximally activated. Therefore, we tested the effects of exendin-9, a GLP-1R antagonist. Exendin-9 was shown to reduce GSIS by 39% and 61% in ND islets and T2D islets, respectively. We also observed significantly more GLP-1+ α cells in T2D islets compared with ND islets obtained from cadaveric donors. Furthermore, GLP-1+ α cells were also identified in pancreatic islet sections obtained from living donors undergoing surgery. Conclusions In summary, we demonstrated that human islets secrete robust amounts of GLP-1 from an α cell subpopulation and that GLP-1R signalling may support GSIS to a greater extent in T2D islets. Here we show that glucagon-like peptide-1 (GLP-1) is secreted from a subpopulation of α cells within human islets. Human islets secrete ∼50-fold more GLP-1 than murine islets and that ∼40% of the total human α cells contain GLP-1. We observed significantly more GLP-1+ α cells in islets from donors with type 2 diabetes than in islets from donors with no diabetes. GLP-1+ α cells can also be detected in pancreatic islet sections obtained from living donors undergoing surgery. GLP-1 receptor signaling may support insulin secretion to a greater extent in type 2 diabetes.
Collapse
Affiliation(s)
- Scott A Campbell
- Alberta Diabetes Institute and the Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Dominic P Golec
- Alberta Diabetes Institute and the Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Matt Hubert
- Alberta Diabetes Institute and the Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Janyne Johnson
- Alberta Diabetes Institute and the Department of Physiology, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Nicole Salamon
- Alberta Diabetes Institute and the Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Amy Barr
- Alberta Diabetes Institute and the Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Patrick E MacDonald
- Alberta Diabetes Institute and the Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Koenraad Philippaert
- Alberta Diabetes Institute and the Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Canada
| | - Peter E Light
- Alberta Diabetes Institute and the Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Canada.
| |
Collapse
|
46
|
Yin HN, Hao JW, Chen Q, Li F, Yin S, Zhou M, Zhang QH, Yao YM, Chai JK. Plasma glucagon-like peptide 1 was associated with hospital-acquired infections and long-term mortality in burn patients. Surgery 2020; 167:1016-1022. [PMID: 32295709 DOI: 10.1016/j.surg.2020.01.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 12/19/2019] [Accepted: 01/07/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND Although glucagon-like peptide 1 levels have been closely associated with inflammation and mortality in septic patients, the clinical importance of glucagon-like peptide 1 on hospital-acquired infections and long-term mortality after burn injury remains unexplored. METHODS Plasma samples from 144 burn patients were collected on admission to determine total glucagon-like peptide 1, interleukin 6, and monocyte chemotactic protein-1 levels. Hospital-acquired infections were determined by positive microbial culture. One-year mortality was assessed by telephone interview. Factors associated with glucagon-like peptide 1 were determined by multivariable linear logistic regression. Predicting the clinical importance of glucagon-like peptide 1 on the development of hospital-acquired infections and mortality were determined by Cox proportional hazards models and further by receiver operating characteristic curve analysis. Kaplan-Meier analyses were performed to examine whether the mean glucagon-like peptide 1 level of the cohort could discriminate the hospital-acquired infections-free survival. RESULTS Median burn size was 41% (19%-70%) of total body surface area. Hospital-acquired infections developed in 36 (25%) patients after a mean of 10 ± 1 days after injury. Interleukin 6, monocyte chemotactic protein-1, and blood urea nitrogen levels and thrombin time were independently associated with increased glucagon-like peptide 1 levels. Levels of glucagon-like peptide 1 (median, interquartile range) were greater in patients who developed hospital-acquired infections than in those who did not (237 pmol/L, 76-524 vs 80 pmol/L, 51-158; P < .001) and in patients who died (536 pmol/L, interquartile range: 336-891 pmol vs 98 pmol/L, 47-189; P < .001). Although the glucagon-like peptide 1 level could not predict hospital-acquired infections-free survival in individual patients, it could predict 1-year mortality independently (P = .021). Moreover, a glucagon-like peptide 1 level of 200 pmol/L could discriminate hospital-acquired infections-free survival (P < .001). CONCLUSION Admission glucagon-like peptide 1 level can discriminate hospital-acquired infections-free survival and predict long-term mortality in a group of patients with burn injury. Our data suggests that glucagon-like peptide 1 may be a predictive biomarker for hospital-acquired infections and mortality in burn patients.
Collapse
Affiliation(s)
- Hui-Nan Yin
- Department of Burn and Plastic Surgery, Fourth Medical Center of Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China
| | - Ji-Wei Hao
- Trauma Repairment and Tissue Regeneration Center, Department of Medical Innovation Study, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China
| | - Qi Chen
- Department of Burn and Plastic Surgery, Fourth Medical Center of Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China
| | - Feng Li
- Department of Burn and Plastic Surgery, Fourth Medical Center of Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China
| | - Song Yin
- Department of Outpatient Service, Fourth Medical Center of Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China
| | - Min Zhou
- Neurocritical Care Unit, The First Affiliated Hospital of University of Science and Technology of China, Division of Life Sciences and Medicine, Hefei, Anhui, People's Republic of China
| | - Qing-Hong Zhang
- Trauma Repairment and Tissue Regeneration Center, Department of Medical Innovation Study, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China.
| | - Yong-Ming Yao
- Trauma Repairment and Tissue Regeneration Center, Department of Medical Innovation Study, Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China
| | - Jia-Ke Chai
- Department of Burn and Plastic Surgery, Fourth Medical Center of Chinese People's Liberation Army General Hospital, Beijing, People's Republic of China
| |
Collapse
|
47
|
Finan B, Capozzi ME, Campbell JE. Repositioning Glucagon Action in the Physiology and Pharmacology of Diabetes. Diabetes 2020; 69:532-541. [PMID: 31178432 PMCID: PMC7085250 DOI: 10.2337/dbi19-0004] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 05/30/2019] [Indexed: 01/03/2023]
Abstract
Glucagon is historically described as the counterregulatory hormone to insulin, induced by fasting/hypoglycemia to raise blood glucose through action mediated in the liver. However, it is becoming clear that the biology of glucagon is much more complex and extends beyond hepatic actions to exert control on glucose metabolism. We discuss the inconsistencies with the canonical view that glucagon is primarily a hyperglycemic agent driven by fasting/hypoglycemia and highlight the recent advances that have reshaped the metabolic role of glucagon. These concepts are placed within the context of both normal physiology and the pathophysiology of disease and then extended to discuss emerging strategies that incorporate glucagon agonism in the pharmacology of treating diabetes.
Collapse
Affiliation(s)
- Brian Finan
- Novo Nordisk Research Center, Indianapolis, IN
| | - Megan E Capozzi
- Duke Molecular Physiology Institute, Duke University, Durham, NC
| | - Jonathan E Campbell
- Duke Molecular Physiology Institute, Duke University, Durham, NC
- Division of Endocrinology, Department of Medicine, Duke University, Durham, NC
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC
| |
Collapse
|
48
|
Davis EM, Sandoval DA. Glucagon‐Like Peptide‐1: Actions and Influence on Pancreatic Hormone Function. Compr Physiol 2020; 10:577-595. [DOI: 10.1002/cphy.c190025] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
49
|
Tanaka A, Watanabe A, Nakano Y, Matsumoto M, Okazaki Y, Miyajima A. Reversible expansion of pancreatic islet progenitors derived from human induced pluripotent stem cells. Genes Cells 2020; 25:302-311. [PMID: 32065490 DOI: 10.1111/gtc.12759] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/13/2020] [Accepted: 02/13/2020] [Indexed: 12/18/2022]
Abstract
Transplantation of pancreatic islets is an effective therapy for severe type 1 diabetes. As donor shortage is a major problem for this therapy, attempts have been made to produce a large number of pancreatic islets from human pluripotent stem cells (hPSCs). However, as the differentiation of hPSCs to pancreatic islets requires multiple and lengthy processes using various expensive cytokines, the process is variable, low efficiency and costly. Therefore, it would be beneficial if islet progenitors could be expanded. Neurogenin3 (NGN3)-expressing pancreatic endocrine progenitor (EP) cells derived from hPSCs exhibited the ability to differentiate into pancreatic islets while their cell cycle was arrested. By using a lentivirus vector, we introduced several growth-promoting genes into NGN3-expressing EP cells. We found that SV40LT expression induced proliferation of the EP cells but reduced the expression of endocrine lineage-commitment factors, NGN3, NEUROD1 and NKX2.2, resulting in the suppression of islet differentiation. By using the Cre-loxP system, we removed SV40LT after the expansion, leading to re-expression of endocrine-lineage commitment genes and differentiation into functional pancreatic islets. Thus, our findings will pave a way to generate a large quantity of functional pancreatic islets through the expansion of EP cells from hPSCs.
Collapse
Affiliation(s)
- Anna Tanaka
- Laboratory of Cell Growth and Differentiation, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | - Ami Watanabe
- Laboratory of Cell Growth and Differentiation, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | - Yasuhiro Nakano
- Laboratory of Cell Growth and Differentiation, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| | - Masahito Matsumoto
- Intractable Disease Research Center, Juntendo University, Tokyo, Japan.,Department of Biofunction Research, Institute of Biomaterials and Bioenginnering, Tokyo Medical University and Dental University, Tokyo, Japan
| | - Yasushi Okazaki
- Intractable Disease Research Center, Juntendo University, Tokyo, Japan
| | - Atsushi Miyajima
- Laboratory of Cell Growth and Differentiation, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
50
|
Hartig SM, Cox AR. Paracrine signaling in islet function and survival. J Mol Med (Berl) 2020; 98:451-467. [PMID: 32067063 DOI: 10.1007/s00109-020-01887-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 02/05/2020] [Accepted: 02/11/2020] [Indexed: 02/06/2023]
Abstract
The pancreatic islet is a dense cellular network comprised of several cell types with endocrine function vital in the control of glucose homeostasis, metabolism, and feeding behavior. Within the islet, endocrine hormones also form an intricate paracrine network with supportive cells (endothelial, neuronal, immune) and secondary signaling molecules regulating cellular function and survival. Modulation of these signals has potential consequences for diabetes development, progression, and therapeutic intervention. Beta cell loss, reduced endogenous insulin secretion, and dysregulated glucagon secretion are hallmark features of both type 1 and 2 diabetes that not only impact systemic regulation of glucose, but also contribute to the function and survival of cells within the islet. Advancing research and technology have revealed new islet biology (cellular identity and transcriptomes) and identified previously unrecognized paracrine signals and mechanisms (somatostatin and ghrelin paracrine actions), while shifting prior views of intraislet communication. This review will summarize the paracrine signals regulating islet endocrine function and survival, the disruption and dysfunction that occur in diabetes, and potential therapeutic targets to preserve beta cell mass and function.
Collapse
Affiliation(s)
- Sean M Hartig
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Aaron R Cox
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
| |
Collapse
|