1
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Ullah Khan S, Daniela Hernández-González K, Ali A, Shakeel Raza Rizvi S. Diabetes and the fabkin complex: A dual-edged sword. Biochem Pharmacol 2024; 223:116196. [PMID: 38588831 DOI: 10.1016/j.bcp.2024.116196] [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: 11/21/2023] [Revised: 03/27/2024] [Accepted: 04/05/2024] [Indexed: 04/10/2024]
Abstract
The Fabkin complex, composed of FABP4, ADK, and NDPKs, emerges as a novel regulator of insulin-producing beta cells, offering promising prospects for diabetes treatment. Our approach, which combines literature review and database analysis, sets the stage for future research. These findings hold significant implications for both diabetes treatment and research, as they present potential therapeutic targets for personalized treatment, leading to enhanced patient outcomes and a deeper comprehension of the disease. The multifaceted role of the Fabkin complex in glucose metabolism, insulin resistance, anti-inflammation, beta cell proliferation, and vascular function underscores its therapeutic potential, reshaping diabetes management and propelling advancements in the field.
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Affiliation(s)
- Safir Ullah Khan
- Department of Zoology, Wildlife & Fisheries, Faculty of sciences, Pir Mehr Ali Shah Arid Agriculture University, P.C. 46300, Rawalpindi, Pakistan
| | - Karla Daniela Hernández-González
- Facultad de Biología, Universidad Veracruzana, Circuito Gonzalo Aguirre Beltrán s/n, Zona Universitaria, C.P. 91000 Xalapa, Veracruz, México
| | - Amir Ali
- Nanoscience and Nanotechnology Program, Center for Research and Advanced Studies of the IPN, Mexico City, Mexico
| | - Syed Shakeel Raza Rizvi
- Department of Zoology, Wildlife & Fisheries, Faculty of sciences, Pir Mehr Ali Shah Arid Agriculture University, P.C. 46300, Rawalpindi, Pakistan.
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2
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Ghiasi SM, Christensen NM, Pedersen PA, Skovhøj EZ, Novak I. Imaging of extracellular and intracellular ATP in pancreatic beta cells reveals correlation between glucose metabolism and purinergic signalling. Cell Signal 2024; 117:111109. [PMID: 38373668 DOI: 10.1016/j.cellsig.2024.111109] [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: 12/01/2023] [Revised: 01/24/2024] [Accepted: 02/15/2024] [Indexed: 02/21/2024]
Abstract
Adenosine triphosphate (ATP) is a universal energy molecule and yet cells release it and extracellular ATP is an important signalling molecule between cells. Monitoring of ATP levels outside of cells is important for our understanding of physiological and pathophysiological processes in cells/tissues. Here, we focus on pancreatic beta cells (INS-1E) and test the hypothesis that there is an association between intra- and extracellular ATP levels which depends on glucose provision. We imaged real-time changes in extracellular ATP in pancreatic beta cells using two sensors tethered to extracellular aspects of the plasma membrane (eATeam3.10, iATPSnFR1.0). Increase in glucose induced fast micromolar ATP release to the cell surface, depending on glucose concentrations. Chronic pre-treatment with glucose increased the basal ATP signal. In addition, we co-expressed intracellular ATP sensors (ATeam1.30, PercevalHR) in the same cultures and showed that glucose induced fast increases in extracellular and intracellular ATP. Glucose and extracellular ATP stimulated glucose transport monitored by the glucose sensor (FLII12Pglu-700uDelta6). In conclusion, we propose that in beta cells there is a dynamic relation between intra- and extracellular ATP that depends on glucose transport and metabolism and these processes may be tuned by purinergic signalling. Future development of ATP sensors for imaging may aid development of novel approaches to target extracellular ATP in, for example, type 2 diabetes mellitus therapy.
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Affiliation(s)
- Seyed M Ghiasi
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark
| | - Nynne M Christensen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark
| | - Per A Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark
| | - Emil Z Skovhøj
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark
| | - Ivana Novak
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Denmark.
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3
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Yang M, Dyachok O, Xu Y, Gylfe E, Idevall-Hagren O, Tengholm A. Indicator-dependent differences in detection of local intracellular Ca 2+ release events evoked by voltage-gated Ca 2+ entry in pancreatic β-cells. Cell Signal 2023:110805. [PMID: 37437828 DOI: 10.1016/j.cellsig.2023.110805] [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: 05/18/2023] [Revised: 06/22/2023] [Accepted: 07/08/2023] [Indexed: 07/14/2023]
Abstract
Genetically encoded Ca2+ indicators have become widely used in cell signalling studies as they offer advantages over cell-loaded dye indicators in enabling specific cellular or subcellular targeting. Comparing responses from dye and protein-based indicators may provide information about indicator properties and cell physiology, but side-by-side recordings in cells are scarce. In this study, we compared cytoplasmic Ca2+ concentration ([Ca2+]i) changes in insulin-secreting β-cells recorded with commonly used dyes and indicators based on circularly permuted fluorescent proteins. Total internal reflection fluorescence (TIRF) imaging of K+ depolarization-triggered submembrane [Ca2+]i increases showed that the dyes Fluo-4 and Fluo-5F mainly reported stable [Ca2+]i elevations, whereas the proteins R-GECO1 and GCaMP5G more often reported distinct [Ca2+]i spikes from an elevated level. [Ca2+]i spiking occurred also in glucose-stimulated cells. The spikes reflected Ca2+ release from the endoplasmic reticulum, triggered by autocrine activation of purinergic receptors after exocytotic release of ATP and/or ADP, and the spikes were consequently prevented by SERCA inhibition or P2Y1-receptor antagonism. Widefield imaging, which monitors the entire cytoplasm, increased the spike detection by the Ca2+ dyes. The indicator-dependent response patterns were unrelated to Ca2+ binding affinity, buffering and mobility, and probably reflects the much slower dissociation kinetics of protein compared to dye indicators. Ca2+ dyes thus report signalling within the submembrane space excited by TIRF illumination, whereas the protein indicators also catch Ca2+ events originating outside this volume. The study highlights that voltage-dependent Ca2+ entry in β-cells is tightly linked to local intracellular Ca2+ release mediated via an autocrine route that may be more important than previously reported direct Ca2+ effects on phospholipase C or on intracellular channels mediating calcium-induced calcium release.
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Affiliation(s)
- Mingyu Yang
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden
| | - Oleg Dyachok
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden
| | - Yunjian Xu
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden
| | - Erik Gylfe
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden
| | - Olof Idevall-Hagren
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-75123 Uppsala, Sweden.
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4
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Mu-U-Min RBA, Diane A, Allouch A, Al-Siddiqi HH. Ca 2+-Mediated Signaling Pathways: A Promising Target for the Successful Generation of Mature and Functional Stem Cell-Derived Pancreatic Beta Cells In Vitro. Biomedicines 2023; 11:1577. [PMID: 37371672 DOI: 10.3390/biomedicines11061577] [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: 04/17/2023] [Revised: 05/18/2023] [Accepted: 05/23/2023] [Indexed: 06/29/2023] Open
Abstract
Diabetes mellitus is a chronic disease affecting over 500 million adults globally and is mainly categorized as type 1 diabetes mellitus (T1DM), where pancreatic beta cells are destroyed, and type 2 diabetes mellitus (T2DM), characterized by beta cell dysfunction. This review highlights the importance of the divalent cation calcium (Ca2+) and its associated signaling pathways in the proper functioning of beta cells and underlines the effects of Ca2+ dysfunction on beta cell function and its implications for the onset of diabetes. Great interest and promise are held by human pluripotent stem cell (hPSC) technology to generate functional pancreatic beta cells from diabetic patient-derived stem cells to replace the dysfunctional cells, thereby compensating for insulin deficiency and reducing the comorbidities of the disease and its associated financial and social burden on the patient and society. Beta-like cells generated by most current differentiation protocols have blunted functionality compared to their adult human counterparts. The Ca2+ dynamics in stem cell-derived beta-like cells and adult beta cells are summarized in this review, revealing the importance of proper Ca2+ homeostasis in beta-cell function. Consequently, the importance of targeting Ca2+ function in differentiation protocols is suggested to improve current strategies to use hPSCs to generate mature and functional beta-like cells with a comparable glucose-stimulated insulin secretion (GSIS) profile to adult beta cells.
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Affiliation(s)
- Razik Bin Abdul Mu-U-Min
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), Doha P.O. Box 34110, Qatar
| | - Abdoulaye Diane
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), Doha P.O. Box 34110, Qatar
| | - Asma Allouch
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), Doha P.O. Box 34110, Qatar
| | - Heba H Al-Siddiqi
- Diabetes Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), Doha P.O. Box 34110, Qatar
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5
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Zhou Q, Wang Y, Lu Z, He C, Li L, You M, Wang L, Cao T, Zhao Y, Li Q, Mou A, Shu W, He H, Zhao Z, Liu D, Zhu Z, Gao P, Yan Z. Cx43 acts as a mitochondrial calcium regulator that promotes obesity by inducing the polarization of macrophages in adipose tissue. Cell Signal 2023; 105:110606. [PMID: 36681290 DOI: 10.1016/j.cellsig.2023.110606] [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: 11/06/2022] [Revised: 01/12/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023]
Abstract
Metabolic reprogramming of macrophages initiates the polarization of pro-inflammatory macrophages that exacerbates adipocyte dysfunction and obesity. The imbalance of mitochondrial Ca2+ homeostasis impairs mitochondrial function and promotes inflammation. Connexin 43 (Cx43), a ubiquitous gap junction protein, has been demonstrated to regulate intracellular Ca2+ homeostasis. Here we explored whether macrophage Cx43 affects the obesity process by regulating the polarization of macrophage. HFD treatment induced obesity and exacerbated macrophages infiltration with upregulation of macrophages Cx43. Macrophage-specific knockout of Cx43 reduced HFD-induced obesity by alleviating inflammation in adipose tissue, with less pro-inflammatory M1 macrophage infiltration. Consistently, inhibition or knockdown of Cx43 improved palmitic acid (PA) induced mitochondrial dysfunction, as indicated by improved oxidative phosphorylation (OXPHOS), reduced formation of mitochondria-associated membranes (MAM) and mitochondrial Ca2+ overload. Mechanistically, Cx43 interacted with the mitochondrial Ca2+ uniporter (MCU) and knockdown of Cx43 alleviated PA-induced succinate dehydrogenase (SDH) oxidation by lowering MCU-mediated mitochondrial Ca2+ uptake, which then, promoting the polarization of pro-inflammatory M1 macrophages. Thus, this study identified Cx43 as a mitochondrial Ca2+ regulator that aggravates obesity via promoting macrophages polarized to M1 pro-inflammatory phenotype and suggests that Cx43 might be a promising therapeutic target antagonizing obesity.
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Affiliation(s)
- Qing Zhou
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Yuyan Wang
- School of Medicine, Chongqing University, Chongqing, China
| | - Zongshi Lu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Chengkang He
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Li Li
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Mei You
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Lijuan Wang
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Tingbing Cao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Yu Zhao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Qiang Li
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Aidi Mou
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Wentao Shu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Hongbo He
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Zhigang Zhao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Daoyan Liu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China
| | - Zhiming Zhu
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China.
| | - Peng Gao
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China.
| | - Zhencheng Yan
- Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Army Medical University, and Chongqing Institute of Hypertension, Chongqing, China.
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6
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Harvey KE, Tang S, LaVigne EK, Pratt EPS, Hockerman GH. RyR2 regulates store-operated Ca2+ entry, phospholipase C activity, and electrical excitability in the insulinoma cell line INS-1. PLoS One 2023; 18:e0285316. [PMID: 37141277 PMCID: PMC10159205 DOI: 10.1371/journal.pone.0285316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/19/2023] [Indexed: 05/05/2023] Open
Abstract
The ER Ca2+ channel ryanodine receptor 2 (RyR2) is required for maintenance of insulin content and glucose-stimulated insulin secretion, in part, via regulation of the protein IRBIT in the insulinoma cell line INS-1. Here, we examined store-operated and depolarization-dependent Ca2+entry using INS-1 cells in which either RyR2 or IRBIT were deleted. Store-operated Ca2+ entry (SOCE) stimulated with thapsigargin was reduced in RyR2KO cells compared to controls, but was unchanged in IRBITKO cells. STIM1 protein levels were not different between the three cell lines. Basal and stimulated (500 μM carbachol) phospholipase C (PLC) activity was also reduced specifically in RyR2KO cells. Insulin secretion stimulated by tolbutamide was reduced in RyR2KO and IRBITKO cells compared to controls, but was potentiated by an EPAC-selective cAMP analog in all three cell lines. Cellular PIP2 levels were increased and cortical f-actin levels were reduced in RyR2KO cells compared to controls. Whole-cell Cav channel current density was increased in RyR2KO cells compared to controls, and barium current was reduced by acute activation of the lipid phosphatase pseudojanin preferentially in RyR2KO cells over control INS-1 cells. Action potentials stimulated by 18 mM glucose were more frequent in RyR2KO cells compared to controls, and insensitive to the SK channel inhibitor apamin. Taken together, these results suggest that RyR2 plays a critical role in regulating PLC activity and PIP2 levels via regulation of SOCE. RyR2 also regulates β-cell electrical activity by controlling Cav current density and SK channel activation.
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Affiliation(s)
- Kyle E Harvey
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
| | - Shiqi Tang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
| | - Emily K LaVigne
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, Indiana, United States of America
| | - Evan P S Pratt
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
- Purdue Interdisciplinary Life Sciences Program, Purdue University, West Lafayette, Indiana, United States of America
| | - Gregory H Hockerman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, United States of America
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7
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Xiao X, Luo Y, Peng D. Updated Understanding of the Crosstalk Between Glucose/Insulin and Cholesterol Metabolism. Front Cardiovasc Med 2022; 9:879355. [PMID: 35571202 PMCID: PMC9098828 DOI: 10.3389/fcvm.2022.879355] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 04/07/2022] [Indexed: 12/19/2022] Open
Abstract
Glucose and cholesterol engage in almost all human physiological activities. As the primary energy substance, glucose can be assimilated and converted into diverse essential substances, including cholesterol. Cholesterol is mainly derived from de novo biosynthesis and the intestinal absorption of diets. It is evidenced that glucose/insulin promotes cholesterol biosynthesis and uptake, which have been targeted by several drugs for lipid-lowering, e.g., bempedoic acid, statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors. Inversely, these lipid-lowering drugs may also interfere with glucose metabolism. This review would briefly summarize the mechanisms of glucose/insulin-stimulated cholesterol biosynthesis and uptake, and discuss the effect and mechanisms of lipid-lowering drugs and genetic mutations on glucose homeostasis, aiming to help better understand the intricate relationship between glucose and cholesterol metabolism.
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8
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Marcheva B, Weidemann BJ, Taguchi A, Perelis M, Ramsey KM, Newman MV, Kobayashi Y, Omura C, Manning Fox JE, Lin H, Macdonald PE, Bass J. P2Y1 purinergic receptor identified as a diabetes target in a small-molecule screen to reverse circadian β-cell failure. eLife 2022; 11:e75132. [PMID: 35188462 PMCID: PMC8860442 DOI: 10.7554/elife.75132] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/21/2022] [Indexed: 12/18/2022] Open
Abstract
The mammalian circadian clock drives daily oscillations in physiology and behavior through an autoregulatory transcription feedback loop present in central and peripheral cells. Ablation of the core clock within the endocrine pancreas of adult animals impairs the transcription and splicing of genes involved in hormone exocytosis and causes hypoinsulinemic diabetes. Here, we developed a genetically sensitized small-molecule screen to identify druggable proteins and mechanistic pathways involved in circadian β-cell failure. Our approach was to generate β-cells expressing a nanoluciferase reporter within the proinsulin polypeptide to screen 2640 pharmacologically active compounds and identify insulinotropic molecules that bypass the secretory defect in CRISPR-Cas9-targeted clock mutant β-cells. We validated hit compounds in primary mouse islets and identified known modulators of ligand-gated ion channels and G-protein-coupled receptors, including the antihelmintic ivermectin. Single-cell electrophysiology in circadian mutant mouse and human cadaveric islets revealed ivermectin as a glucose-dependent secretagogue. Genetic, genomic, and pharmacological analyses established the P2Y1 receptor as a clock-controlled mediator of the insulinotropic activity of ivermectin. These findings identify the P2Y1 purinergic receptor as a diabetes target based upon a genetically sensitized phenotypic screen.
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Affiliation(s)
- Biliana Marcheva
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Benjamin J Weidemann
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Akihiko Taguchi
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of MedicineChicagoUnited States
- Division of Endocrinology, Metabolism, Hematological Science and Therapeutics, Department of Bio-Signal Analysis, Yamaguchi University, Graduate School of Medicine, 1-1-1YamaguchiJapan
| | - Mark Perelis
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of MedicineChicagoUnited States
- Ionis Pharmaceuticals, IncCarlsbadUnited States
| | - Kathryn Moynihan Ramsey
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Marsha V Newman
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Yumiko Kobayashi
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Chiaki Omura
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Jocelyn E Manning Fox
- Department of Pharmacology, Alberta Diabetes Institute, University of AlbertaEdmonton, ABCanada
| | - Haopeng Lin
- Department of Pharmacology, Alberta Diabetes Institute, University of AlbertaEdmonton, ABCanada
| | - Patrick E Macdonald
- Department of Pharmacology, Alberta Diabetes Institute, University of AlbertaEdmonton, ABCanada
| | - Joseph Bass
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of MedicineChicagoUnited States
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9
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Hauke S, Rada J, Tihanyi G, Schilling D, Schultz C. ATP is an essential autocrine factor for pancreatic β-cell signaling and insulin secretion. Physiol Rep 2022; 10:e15159. [PMID: 35001557 PMCID: PMC8743876 DOI: 10.14814/phy2.15159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 09/05/2021] [Indexed: 06/14/2023] Open
Abstract
ATP has been previously identified as an autocrine signaling factor that is co-released with insulin to modulate and propagate β-cell activity within islets of Langerhans. Here, we show that β-cell activity and insulin secretion essentially rely on the presence of extracellular ATP. For this, we monitored changes of the intracellular Ca2+ concentration ([Ca2+ ]i oscillations) as an immediate read-out for insulin secretion in live cell experiments. Extensive washing of cells or depletion of extracellular ATP levels by recombinant apyrase reduced [Ca2+ ]i oscillations and insulin secretion in pancreatic cell lines and primary β-cells. Following ATP depletion, [Ca2+ ]i oscillations were stimulated by the replenishment of ATP in a concentration-dependent manner. Inhibition of endogenous ecto-ATP nucleotidases increased extracellular ATP levels, along with [Ca2+ ]i oscillations and insulin secretion, indicating that there is a constant supply of ATP to the extracellular space. Our combined results demonstrate that extracellular ATP is essential for β-cell activity. The presented work suggests extracellular ATPases as potential drug targets for the modulation of insulin release. We further found that exogenous fatty acids compensated for depleted extracellular ATP levels by the recovery of [Ca2+ ]i oscillations, indicating that autocrine factors mutually compensate for the loss of others. Thereby, our results contribute to a more detailed and complete understanding of the general role of autocrine signaling factors as a fundamental regulatory mechanism of β-cell activity and insulin secretion.
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Affiliation(s)
- Sebastian Hauke
- Cell Biology & Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Jona Rada
- Cell Biology & Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Gergely Tihanyi
- Cell Biology & Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Danny Schilling
- Cell Biology & Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Carsten Schultz
- Cell Biology & Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University (OHSU), Portland, Oregon, USA
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10
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Prentice KJ, Saksi J, Robertson LT, Lee GY, Inouye KE, Eguchi K, Lee A, Cakici O, Otterbeck E, Cedillo P, Achenbach P, Ziegler AG, Calay ES, Engin F, Hotamisligil GS. A hormone complex of FABP4 and nucleoside kinases regulates islet function. Nature 2021; 600:720-726. [PMID: 34880500 DOI: 10.1038/s41586-021-04137-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/14/2021] [Indexed: 11/09/2022]
Abstract
The liberation of energy stores from adipocytes is critical to support survival in times of energy deficit; however, uncontrolled or chronic lipolysis associated with insulin resistance and/or insulin insufficiency disrupts metabolic homeostasis1,2. Coupled to lipolysis is the release of a recently identified hormone, fatty-acid-binding protein 4 (FABP4)3. Although circulating FABP4 levels have been strongly associated with cardiometabolic diseases in both preclinical models and humans4-7, no mechanism of action has yet been described8-10. Here we show that hormonal FABP4 forms a functional hormone complex with adenosine kinase (ADK) and nucleoside diphosphate kinase (NDPK) to regulate extracellular ATP and ADP levels. We identify a substantial effect of this hormone on beta cells and given the central role of beta-cell function in both the control of lipolysis and development of diabetes, postulate that hormonal FABP4 is a key regulator of an adipose-beta-cell endocrine axis. Antibody-mediated targeting of this hormone complex improves metabolic outcomes, enhances beta-cell function and preserves beta-cell integrity to prevent both type 1 and type 2 diabetes. Thus, the FABP4-ADK-NDPK complex, Fabkin, represents a previously unknown hormone and mechanism of action that integrates energy status with the function of metabolic organs, and represents a promising target against metabolic disease.
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Affiliation(s)
- Kacey J Prentice
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Jani Saksi
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Lauren T Robertson
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Grace Y Lee
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Karen E Inouye
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Kosei Eguchi
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Alexandra Lee
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Ozgur Cakici
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Emily Otterbeck
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Paulina Cedillo
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Peter Achenbach
- Institute of Diabetes Research, Helmholtz Zentrum Munchen, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Anette-Gabriele Ziegler
- Institute of Diabetes Research, Helmholtz Zentrum Munchen, German Research Center for Environmental Health, Munich-Neuherberg, Germany
| | - Ediz S Calay
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA
| | - Feyza Engin
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA.,Departments of Biomolecular Chemistry and Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Gökhan S Hotamisligil
- Sabri Ülker Center for Metabolic Research, Harvard T. H. Chan School of Public Health, Department of Molecular Metabolism, Boston, MA, USA. .,Broad Institute of Harvard and MIT, Cambridge, MA, USA.
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11
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Langlhofer G, Kogel A, Schaefer M. Glucose-induced [Ca2+]i oscillations in β cells are composed of trains of spikes within a subplasmalemmal microdomain. Cell Calcium 2021; 99:102469. [PMID: 34509871 DOI: 10.1016/j.ceca.2021.102469] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 10/20/2022]
Abstract
Electrical activity and oscillations of cytosolic Ca2+ concentrations ([Ca2+]i) that trigger insulin release in response to glucose are key functions of pancreatic β cells. Although oscillatory Ca2+ signals have been intensively studied in β cells, their lower frequency did not match that of electrical activity. In addition, the measured peak [Ca2+]i did not reach levels that are typically required by synaptotagmins to elicit the release of insulin-containing vesicles in live-cell experiments. We therefore sought to resolve the Ca2+ dynamics in the subplasmalemmal microdomain that is critical for triggering fast exocytosis. Applying total internal reflection fluorescence (TIRF) microscopy in insulin-producing INS-1E and primary mouse β cells, we resolved extraordinary fast trains of Ca2+ spiking (frequency > 3 s-1) in response to glucose exposure. Using a low-affinity [Ca2+]i indicator dye, we provide experimental evidence that Ca2+ spikes reach low micromolar apparent concentrations in the vicinity of the plasma membrane. Analysis of Ca2+ spikes evoked by repeated depolarization for 10 ms closely matched the Ca2+ dynamics observed upon glucose application. To our knowledge, this is the first study that experimentally demonstrates Ca2+ spikes in β cells with velocities that resemble those of bursting or continuously appearing trains of action potentials (APs) in non-patched cells.
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Affiliation(s)
- Georg Langlhofer
- Rudolf-Boehm-Institute for Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany
| | - Alexander Kogel
- Rudolf-Boehm-Institute for Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany
| | - Michael Schaefer
- Rudolf-Boehm-Institute for Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany.
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12
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Mesto N, Bailbe D, Eskandar M, Pommier G, Gil S, Tolu S, Movassat J, Tourrel-Cuzin C. Involvement of P2Y signaling in the restoration of glucose-induced insulin exocytosis in pancreatic β cells exposed to glucotoxicity. J Cell Physiol 2021; 237:881-896. [PMID: 34435368 DOI: 10.1002/jcp.30564] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 07/27/2021] [Accepted: 08/13/2021] [Indexed: 12/14/2022]
Abstract
Purinergic P2Y receptors, by binding adenosine triphosphate (ATP), are known for enhancing glucose-stimulated insulin secretion (GSIS) in pancreatic β cells. However, the impact of these receptors in the actin dynamics and insulin granule exocytosis in these cells is not established, neither in normal nor in glucotoxic environment. In this study, we investigate the involvement of P2Y receptors on the behavior of insulin granules and the subcortical actin network dynamics in INS-1 832/13 β cells exposed to normal or glucotoxic environment and their role in GSIS. Our results show that the activation of P2Y purinergic receptors by ATP or its agonist increase the insulin granules exocytosis and the reorganization of the subcortical actin network and participate in the potentiation of GSIS. In addition, their activation in INS-1832/13 β-cells, with impaired insulin secretion following exposure to elevated glucose levels, restores GSIS competence through the distal steps of insulin exocytosis. These results are confirmed ex vivo by perifusion experiments on islets from type 2 diabetic (T2D) Goto-Kakizaki (GK) rats. Indeed, the P2Y receptor agonist restores the altered GSIS, which is normally lost in this T2D animal model. Moreover, we observed an improvement of the glucose tolerance, following the acute intraperitoneal injection of the P2Y agonist concomitantly with glucose, in diabetic GK rats. All these data provide new insights into the unprecedented therapeutic role of P2Y purinergic receptors in the pathophysiology of T2D.
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Affiliation(s)
- Nour Mesto
- 'Université de Paris' 'Unit of Functional and Adaptative Biology (BFA)', CNRS, UMR 8251, Team 'Biologie et Pathologie du Pancréas Endocrine', Paris, France
| | - Danielle Bailbe
- 'Université de Paris' 'Unit of Functional and Adaptative Biology (BFA)', CNRS, UMR 8251, Team 'Biologie et Pathologie du Pancréas Endocrine', Paris, France
| | - Myriam Eskandar
- 'Université de Paris' 'Unit of Functional and Adaptative Biology (BFA)', CNRS, UMR 8251, Team 'Biologie et Pathologie du Pancréas Endocrine', Paris, France
| | - Gaëlle Pommier
- 'Université de Paris' 'Unit of Functional and Adaptative Biology (BFA)', CNRS, UMR 8251, Team 'Biologie et Pathologie du Pancréas Endocrine', Paris, France
| | - Stéphanie Gil
- 'Université de Paris' 'Unit of Functional and Adaptative Biology (BFA)', CNRS, UMR 8251, Team 'Biologie et Pathologie du Pancréas Endocrine', Paris, France.,Université de Paris, UFR Sciences du Vivant (SDV), Paris, France
| | - Stefania Tolu
- 'Université de Paris' 'Unit of Functional and Adaptative Biology (BFA)', CNRS, UMR 8251, Team 'Biologie et Pathologie du Pancréas Endocrine', Paris, France
| | - Jamileh Movassat
- 'Université de Paris' 'Unit of Functional and Adaptative Biology (BFA)', CNRS, UMR 8251, Team 'Biologie et Pathologie du Pancréas Endocrine', Paris, France
| | - Cécile Tourrel-Cuzin
- 'Université de Paris' 'Unit of Functional and Adaptative Biology (BFA)', CNRS, UMR 8251, Team 'Biologie et Pathologie du Pancréas Endocrine', Paris, France
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13
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Olaniru OE, Cheng J, Ast J, Arvaniti A, Atanes P, Huang GC, King AJF, Jones PM, Broichhagen J, Hodson DJ, Persaud SJ. SNAP-tag-enabled super-resolution imaging reveals constitutive and agonist-dependent trafficking of GPR56 in pancreatic β-cells. Mol Metab 2021; 53:101285. [PMID: 34224919 PMCID: PMC8326393 DOI: 10.1016/j.molmet.2021.101285] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/19/2021] [Accepted: 06/28/2021] [Indexed: 12/25/2022] Open
Abstract
Objective Members of the adhesion G protein-coupled receptor (aGPCR) subfamily are important actors in metabolic processes, with GPR56 (ADGRG1) emerging as a possible target for type 2 diabetes therapy. GPR56 can be activated by collagen III, its endogenous ligand, and by a synthetic seven amino-acid peptide (TYFAVLM; P7) contained within the GPR56 Stachel sequence. However, the mechanisms regulating GPR56 trafficking dynamics and agonist activities are not yet clear. Methods Here, we introduced SNAPf-tag into the N-terminal segment of GPR56 to monitor GPR56 cellular activity in situ. Confocal and super-resolution microscopy were used to investigate the trafficking pattern of GPR56 in native MIN6 β-cells and in MIN6 β-cells where GPR56 had been deleted by CRISPR-Cas9 gene editing. Insulin secretion, changes in intracellular calcium, and β-cell apoptosis were determined by radioimmunoassay, single-cell calcium microfluorimetry, and measuring caspase 3/7 activities, respectively, in MIN6 β-cells and human islets. Results SNAP-tag labelling indicated that GPR56 predominantly underwent constitutive internalisation in the absence of an exogenous agonist, unlike GLP-1R. Collagen III further stimulated GPR56 internalisation, whereas P7 was without significant effect. The overexpression of GPR56 in MIN6 β-cells did not affect insulin secretion. However, it was associated with reduced β-cell apoptosis, while the deletion of GPR56 made MIN6 β-cells more susceptible to cytokine-induced apoptosis. P7 induced a rapid increase in the intracellular calcium in MIN6 β-cells (in a GPR56-dependent manner) and human islets, and it also caused a sustained and reversible increase in insulin secretion from human islets. Collagen III protected human islets from cytokine-induced apoptosis, while P7 was without significant effect. Conclusions These data indicate that GPR56 exhibits both agonist-dependent and -independent trafficking in β-cells and suggest that while GPR56 undergoes constitutive signalling, it can also respond to its ligands when required. We have also identified that constitutive and agonist-dependent GPR56 activation is coupled to protect β-cells against apoptosis, offering a potential therapeutic target to maintain β-cell mass in type 2 diabetes. GPR56 predominantly underwent constitutive internalisation in β-cells in the absence of exogenous agonist. The GPR56 agonists, collagen III and P7, showed differential effects on GPR56 trafficking and islet functions. Constitutive and agonist-dependent GPR56 activation is coupled to protection of β-cells against apoptosis.
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Affiliation(s)
- Oladapo E Olaniru
- Department of Diabetes, School of Life Course Sciences, King's College London, Guy's Campus, London SE1 1UL, UK.
| | - Jordan Cheng
- Department of Imaging Chemistry and Biology, School of Biomedical Engineering & Imaging Sciences, 4th floor Lambeth Wing, St Thomas' Hospital, London, SE1 7EH, UK
| | - Julia Ast
- Institute of Metabolism and Systems Research (IMSR), Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Anastasia Arvaniti
- Institute of Metabolism and Systems Research (IMSR), Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Patricio Atanes
- Department of Diabetes, School of Life Course Sciences, King's College London, Guy's Campus, London SE1 1UL, UK
| | - Guo C Huang
- Department of Diabetes, School of Life Course Sciences, King's College London, Guy's Campus, London SE1 1UL, UK
| | - Aileen J F King
- Department of Diabetes, School of Life Course Sciences, King's College London, Guy's Campus, London SE1 1UL, UK
| | - Peter M Jones
- Department of Diabetes, School of Life Course Sciences, King's College London, Guy's Campus, London SE1 1UL, UK
| | - Johannes Broichhagen
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Rössle-Str. 10, 13125, Berlin, Germany
| | - David J Hodson
- Institute of Metabolism and Systems Research (IMSR), Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham, Birmingham, UK; Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
| | - Shanta J Persaud
- Department of Diabetes, School of Life Course Sciences, King's College London, Guy's Campus, London SE1 1UL, UK.
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14
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Gil-Rivera M, Medina-Gali RM, Martínez-Pinna J, Soriano S. Physiology of pancreatic β-cells: Ion channels and molecular mechanisms implicated in stimulus-secretion coupling. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 359:287-323. [PMID: 33832651 DOI: 10.1016/bs.ircmb.2021.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The human and mouse islet of Langerhans is an endocrine organ composed of five different cells types; insulin-secreting β-cells, glucagon-producing α-cells, somatostatin-producing δ-cells, pancreatic polypeptide-secreting PP cells and ɛ-cells that secretes ghrelin. The most important cells are the pancreatic β-cells that comprise around 45-50% of human islets and 75-80% in the mouse. Pancreatic β-cells secrete insulin at high glucose concentration, thereby finely regulating glycaemia by the hypoglycaemic effects of this hormone. Different ion channels are implicated in the stimulus-secretion coupling of insulin. An increase in the intracellular ATP concentration leads to closure KATP channels, depolarizing the cell and opening voltage-gated calcium channels. The increase of intracellular calcium concentration induced by calcium entry through voltage-gated calcium channels promotes insulin secretion. Here, we briefly describe the diversity of ion channels present in pancreatic β-cells and the different mechanisms that are responsible to induce insulin secretion in human and mouse cells. Moreover, we described the pathophysiology due to alterations in the physiology of the main ion channels present in pancreatic β-cell and its implication to predispose metabolic disorders as type 2 diabetes mellitus.
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Affiliation(s)
- Minerva Gil-Rivera
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain.
| | - Regla M Medina-Gali
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain; Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, Elche, Spain
| | - Juan Martínez-Pinna
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain; Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, Elche, Spain
| | - Sergi Soriano
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain; Instituto de Investigación, Desarrollo e Innovación en Biotecnología Sanitaria de Elche (IDiBE), Universidad Miguel Hernández, Elche, Spain.
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15
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Weitz J, Menegaz D, Caicedo A. Deciphering the Complex Communication Networks That Orchestrate Pancreatic Islet Function. Diabetes 2021; 70:17-26. [PMID: 33355306 PMCID: PMC7881851 DOI: 10.2337/dbi19-0033] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 10/01/2020] [Indexed: 12/27/2022]
Abstract
Pancreatic islets are clusters of hormone-secreting endocrine cells that rely on intricate cell-cell communication mechanisms for proper function. The importance of multicellular cooperation in islet cell physiology was first noted nearly 30 years ago in seminal studies showing that hormone secretion from endocrine cell types is diminished when these cells are dispersed. These studies showed that reestablishing cellular contacts in so-called pseudoislets caused endocrine cells to regain hormone secretory function. This not only demonstrated that cooperation between islet cells is highly synergistic but also gave birth to the field of pancreatic islet organoids. Here we review recent advances related to the mechanisms of islet cell cross talk. We first describe new developments that revise current notions about purinergic and GABA signaling in islets. Then we comment on novel multicellular imaging studies that are revealing emergent properties of islet communication networks. We finish by highlighting and discussing recent synthetic approaches that use islet organoids of varied cellular composition to interrogate intraislet signaling mechanisms. This reverse engineering of islets not only will shed light on the mechanisms of intraislet signaling and define communication networks but also may guide efforts aimed at restoring islet function and β-cell mass in diabetes.
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Affiliation(s)
- Jonathan Weitz
- Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL
- Diabetes Research Institute, University of Miami Leonard M. Miller School of Medicine, Miami, FL
| | - Danusa Menegaz
- Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL
| | - Alejandro Caicedo
- Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL
- Diabetes Research Institute, University of Miami Leonard M. Miller School of Medicine, Miami, FL
- Department of Physiology and Biophysics, University of Miami Leonard M. Miller School of Medicine, Miami, FL
- Program in Neuroscience, University of Miami Leonard M. Miller School of Medicine, Miami, FL
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16
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Jain S, Jacobson KA. Purinergic signaling in diabetes and metabolism. Biochem Pharmacol 2020; 187:114393. [PMID: 33359363 DOI: 10.1016/j.bcp.2020.114393] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/22/2022]
Abstract
Purinergic signaling, a concept originally formulated by the late Geoffrey Burnstock (1929-2020), was found to modulate pathways in every physiological system. In metabolic disorders there is a role for both adenosine receptors and P2 (nucleotide) receptors, of which there are two classes, i.e. P2Y metabotropic and P2X ionotropic receptors. The individual roles of the 19 receptors encompassed by this family have been dissected - and in many cases the effects associated with specific cell types, including adipocytes, skeletal muscle, liver cells and immune cells. It is suggested that ligands selective for each of the four adenosine receptors (A1, A2A, A2B and A3), and several of the P2 subtypes (e.g. P2Y6 or P2X7 antagonists) might have therapeutic potential for treating diabetes and obesity. This is a developing story with some conflicting conclusions relevant to drug discovery, which we summarize here.
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Affiliation(s)
- Shanu Jain
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892, USA.
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17
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Almaça J, Caicedo A, Landsman L. Beta cell dysfunction in diabetes: the islet microenvironment as an unusual suspect. Diabetologia 2020; 63:2076-2085. [PMID: 32894318 PMCID: PMC7655222 DOI: 10.1007/s00125-020-05186-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 04/22/2020] [Indexed: 12/13/2022]
Abstract
Cells in different tissues, including endocrine cells in the pancreas, live in complex microenvironments that are rich in cellular and acellular components. Intricate interactions with their microenvironment dictate most cellular properties, such as their function, structure and size, and maintain tissue homeostasis. Pancreatic islets are populated by endocrine, vascular and immune cells that are immersed in the extracellular matrix. While the intrinsic properties of beta cells have been vastly investigated, our understanding of their interactions with their surroundings has only recently begun to unveil. Here, we review current research on the interplay between the islet cellular and acellular components, and the role these components play in beta cell physiology and pathophysiology. Although beta cell failure is a key pathomechanism in diabetes, its causes are far from being fully elucidated. We, thus, propose deleterious alterations of the islet niche as potential underlying mechanisms contributing to beta cell failure. In sum, this review emphasises that the function of the pancreatic islet depends on all of its components. Graphical abstract.
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Affiliation(s)
- Joana Almaça
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th avenue, Miami, FL, 33136, USA.
| | - Alejandro Caicedo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, 1580 NW 10th avenue, Miami, FL, 33136, USA.
| | - Limor Landsman
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv, 69978, Israel.
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18
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Statin Treatment-Induced Development of Type 2 Diabetes: From Clinical Evidence to Mechanistic Insights. Int J Mol Sci 2020; 21:ijms21134725. [PMID: 32630698 PMCID: PMC7369709 DOI: 10.3390/ijms21134725] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/29/2020] [Accepted: 06/30/2020] [Indexed: 12/17/2022] Open
Abstract
Statins are the gold-standard treatment for the prevention of primary and secondary cardiovascular disease, which is the leading cause of mortality worldwide. Despite the safety and relative tolerability of statins, observational studies, clinical trials and meta-analyses indicate an increased risk of developing new-onset type 2 diabetes mellitus (T2DM) after long-term statin treatment. It has been shown that statins can impair insulin sensitivity and secretion by pancreatic β-cells and increase insulin resistance in peripheral tissues. The mechanisms involved in these processes include, among others, impaired Ca2+ signaling in pancreatic β-cells, down-regulation of GLUT-4 in adipocytes and compromised insulin signaling. In addition, it has also been described that statins’ impact on epigenetics may also contribute to statin-induced T2DM via differential expression of microRNAs. This review focuses on the evidence and mechanisms by which statin therapy is associated with the development of T2DM. This review describes the multifactorial combination of effects that most likely contributes to the diabetogenic effects of statins. Clinically, these findings should encourage clinicians to consider diabetes monitoring in patients receiving statin therapy in order to ensure early diagnosis and appropriate management.
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19
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Weitz JR, Jacques-Silva C, Qadir MMF, Umland O, Pereira E, Qureshi F, Tamayo A, Dominguez-Bendala J, Rodriguez-Diaz R, Almaça J, Caicedo A. Secretory Functions of Macrophages in the Human Pancreatic Islet Are Regulated by Endogenous Purinergic Signaling. Diabetes 2020; 69:1206-1218. [PMID: 32245801 PMCID: PMC7243286 DOI: 10.2337/db19-0687] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 03/26/2020] [Indexed: 12/22/2022]
Abstract
Endocrine cells of the pancreatic islet interact with their microenvironment to maintain tissue homeostasis. Communication with local macrophages is particularly important in this context, but the homeostatic functions of human islet macrophages are not known. In this study, we show that the human islet contains macrophages in perivascular regions that are the main local source of the anti-inflammatory cytokine interleukin-10 (IL-10) and the metalloproteinase MMP9. Macrophage production and secretion of these homeostatic factors are controlled by endogenous purinergic signals. In obese and diabetic states, macrophage expression of purinergic receptors MMP9 and IL-10 is reduced. We propose that in those states, exacerbated β-cell activity due to increased insulin demand and increased cell death produce high levels of ATP that downregulate purinergic receptor expression. Loss of ATP sensing in macrophages may reduce their secretory capacity.
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Affiliation(s)
- Jonathan R Weitz
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
| | - Carol Jacques-Silva
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL
| | - Mirza Muhammed Fahd Qadir
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL
- Molecular Cell and Developmental Biology, University of Miami Miller School of Medicine, Miami, FL
| | - Oliver Umland
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL
| | - Elizabeth Pereira
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
| | - Farhan Qureshi
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
- Molecular Cell and Developmental Biology, University of Miami Miller School of Medicine, Miami, FL
| | - Alejandro Tamayo
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
| | - Juan Dominguez-Bendala
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL
- Molecular Cell and Developmental Biology, University of Miami Miller School of Medicine, Miami, FL
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL
| | - Rayner Rodriguez-Diaz
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL
| | - Joana Almaça
- 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
- Molecular Cell and Developmental Biology, University of Miami Miller School of Medicine, Miami, FL
- Program in Neuroscience, University of Miami Miller School of Medicine, Miami, FL
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, Miami, FL
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20
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Jacobson KA, Delicado EG, Gachet C, Kennedy C, von Kügelgen I, Li B, Miras-Portugal MT, Novak I, Schöneberg T, Perez-Sen R, Thor D, Wu B, Yang Z, Müller CE. Update of P2Y receptor pharmacology: IUPHAR Review 27. Br J Pharmacol 2020; 177:2413-2433. [PMID: 32037507 DOI: 10.1111/bph.15005] [Citation(s) in RCA: 150] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 01/12/2020] [Accepted: 01/15/2020] [Indexed: 02/06/2023] Open
Abstract
Eight G protein-coupled P2Y receptor subtypes respond to extracellular adenine and uracil mononucleotides and dinucleotides. P2Y receptors belong to the δ group of rhodopsin-like GPCRs and contain two structurally distinct subfamilies: P2Y1 , P2Y2 , P2Y4 , P2Y6 , and P2Y11 (principally Gq protein-coupled P2Y1 -like) and P2Y12-14 (principally Gi protein-coupled P2Y12 -like) receptors. Brain P2Y receptors occur in neurons, glial cells, and vasculature. Endothelial P2Y1 , P2Y2 , P2Y4 , and P2Y6 receptors induce vasodilation, while smooth muscle P2Y2 , P2Y4 , and P2Y6 receptor activation leads to vasoconstriction. Pancreatic P2Y1 and P2Y6 receptors stimulate while P2Y13 receptors inhibits insulin secretion. Antagonists of P2Y12 receptors, and potentially P2Y1 receptors, are anti-thrombotic agents, and a P2Y2 /P2Y4 receptor agonist treats dry eye syndrome in Asia. P2Y receptor agonists are generally pro-inflammatory, and antagonists may eventually treat inflammatory conditions. This article reviews recent developments in P2Y receptor pharmacology (using synthetic agonists and antagonists), structure and biophysical properties (using X-ray crystallography, mutagenesis and modelling), physiological and pathophysiological roles, and present and potentially future therapeutic targeting.
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Affiliation(s)
- Kenneth A Jacobson
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Disease, National Institutes of Health, Bethesda, Massachusetts
| | - Esmerilda G Delicado
- Dpto. Bioquimica y Biologia Molecular, Universidad Complutense de Madrid, Madrid, Spain
| | - Christian Gachet
- Université de Strasbourg INSERM, EFS Grand Est, BPPS UMR-S 1255, FMTS, Strasbourg, France
| | - Charles Kennedy
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, UK
| | - Ivar von Kügelgen
- Biomedical Research Center, Department of Pharmacology and Toxicology, University of Bonn, Bonn, Germany
| | - Beibei Li
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | | | - Ivana Novak
- Department of Biology, Section for Cell Biology and Physiology, University of Copenhagen, Copenhagen, Denmark
| | - Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Raquel Perez-Sen
- Dpto. Bioquimica y Biologia Molecular, Universidad Complutense de Madrid, Madrid, Spain
| | - Doreen Thor
- Rudolf Schönheimer Institute of Biochemistry, Molecular Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany.,IFB AdiposityDiseases, Leipzig University Medical Center, Leipzig, Germany
| | - Beili Wu
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Zhenlin Yang
- CAS Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Christa E Müller
- Pharmaceutical Institute, Department of Pharmaceutical and Medicinal Chemistry, University of Bonn, Bonn, Germany
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21
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Idevall-Hagren O, Tengholm A. Metabolic regulation of calcium signaling in beta cells. Semin Cell Dev Biol 2020; 103:20-30. [PMID: 32085965 DOI: 10.1016/j.semcdb.2020.01.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/10/2020] [Accepted: 01/28/2020] [Indexed: 12/22/2022]
Abstract
The cytoplasmic Ca2+ concentration ([Ca2+]cyt) regulates a vast number of cellular functions, including insulin secretion from beta cells. The major physiological insulin secretagogue, glucose, triggers [Ca2+]cyt oscillations in beta cells. Synchronization of the oscillations among the beta cells within an islet underlies the generation of pulsatile insulin secretion. This review describes the mechanisms generating [Ca2+]cyt oscillations, the interactions between [Ca2+]cyt and cell metabolism, as well as the contribution of various organelles to the shaping of [Ca2+]cyt signals and insulin secretion. It also discusses how Ca2+ signals are coordinated and spread throughout the islets and data indicating that altered Ca2+ signaling is associated with beta cell dysfunction and development of type 2 diabetes.
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Affiliation(s)
- Olof Idevall-Hagren
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23 Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23 Uppsala, Sweden.
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22
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Khan S, Ferdaoussi M, Bautista A, Bergeron V, Smith N, Poitout V, MacDonald PE. A role for PKD1 in insulin secretion downstream of P2Y 1 receptor activation in mouse and human islets. Physiol Rep 2019; 7:e14250. [PMID: 31591827 PMCID: PMC6779929 DOI: 10.14814/phy2.14250] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 08/30/2019] [Accepted: 09/08/2019] [Indexed: 01/03/2023] Open
Abstract
Along with insulin, β-cells co-secrete the neurotransmitter ATP which acts as a positive autocrine signal via P2Y1 receptors to activate phospholipase C and increase the production of diacylglycerol (DAG). However, the downstream signaling that couples P2Y1 activation to insulin secretion remains to be fully elucidated. Since DAG activates protein kinase D1 (PKD1) to potentiate glucose-stimulated insulin release, we hypothesized that autocrine ATP signaling activates downstream PKD1 to regulate insulin secretion. Indeed, we find that the P2Y1 receptor agonists, MRS2365 and ATP induce, PKD1 phosphorylation at serine 916 in mouse islets. Similarly, direct depolarization of islets by KCl caused PKD1 activation, which is reduced upon P2Y1 antagonism. Potentiation of insulin secretion by P2Y1 activation was lost from PKD1-/- mouse islets, and knockdown of PKD1 reduced the ability of P2Y1 activation to facilitate exocytosis in single mouse β-cells. Finally, qPCR analysis confirmed PKD1 transcript (PRKD1) expression in human islets, and insulin secretion assays showed that inhibition of either P2Y1 or PKD1 signaling impaired glucose-stimulated insulin secretion. Human islets showed donor-to-donor variation in their responses to both P2Y1 and PKD1 inhibition, however, and we find that the P2Y1 -PKD1 pathway contributes a substantially greater proportion of insulin secretion from islets of overweight and obese donors. Thus, PKD1 promotes increased insulin secretion, likely mediating an autocrine ATP effect via P2Y1 receptor activation which may be more important in islets of donors who are overweight or obese.
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Affiliation(s)
- Shara Khan
- Department of Pharmacology and Alberta Diabetes InstituteUniversity of AlbertaEdmontonAlbertaCanada
| | - Mourad Ferdaoussi
- Department of Pharmacology and Alberta Diabetes InstituteUniversity of AlbertaEdmontonAlbertaCanada
| | - Austin Bautista
- Department of Pharmacology and Alberta Diabetes InstituteUniversity of AlbertaEdmontonAlbertaCanada
| | - Valérie Bergeron
- Département de MédecineUniversité de MontréalMontréalQuebecCanada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM)MontréalQuebecCanada
| | - Nancy Smith
- Department of Pharmacology and Alberta Diabetes InstituteUniversity of AlbertaEdmontonAlbertaCanada
| | - Vincent Poitout
- Département de MédecineUniversité de MontréalMontréalQuebecCanada
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CRCHUM)MontréalQuebecCanada
| | - Patrick E. MacDonald
- Department of Pharmacology and Alberta Diabetes InstituteUniversity of AlbertaEdmontonAlbertaCanada
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23
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Bartley C, Brun T, Oberhauser L, Grimaldi M, Molica F, Kwak BR, Bosco D, Chanson M, Maechler P. Chronic fructose renders pancreatic β-cells hyper-responsive to glucose-stimulated insulin secretion through extracellular ATP signaling. Am J Physiol Endocrinol Metab 2019; 317:E25-E41. [PMID: 30912960 DOI: 10.1152/ajpendo.00456.2018] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Fructose is widely used as a sweetener in processed food and is also associated with metabolic disorders, such as obesity. However, the underlying cellular mechanisms remain unclear, in particular, regarding the pancreatic β-cell. Here, we investigated the effects of chronic exposure to fructose on the function of insulinoma cells and isolated mouse and human pancreatic islets. Although fructose per se did not acutely stimulate insulin exocytosis, our data show that chronic fructose rendered rodent and human β-cells hyper-responsive to intermediate physiological glucose concentrations. Fructose exposure reduced intracellular ATP levels without affecting mitochondrial function, induced AMP-activated protein kinase activation, and favored ATP release from the β-cells upon acute glucose stimulation. The resulting increase in extracellular ATP, mediated by pannexin1 (Panx1) channels, activated the calcium-mobilizer P2Y purinergic receptors. Immunodetection revealed the presence of both Panx1 channels and P2Y1 receptors in β-cells. Addition of an ectonucleotidase inhibitor or P2Y1 agonists to naïve β-cells potentiated insulin secretion stimulated by intermediate glucose, mimicking the fructose treatment. Conversely, the P2Y1 antagonist and Panx1 inhibitor reversed the effects of fructose, as confirmed using Panx1-null islets and by the clearance of extracellular ATP by apyrase. These results reveal an important function of ATP signaling in pancreatic β-cells mediating fructose-induced hyper-responsiveness.
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Affiliation(s)
- Clarissa Bartley
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
| | - Thierry Brun
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
| | - Lucie Oberhauser
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
| | - Mariagrazia Grimaldi
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
| | - Filippo Molica
- Department of Pathology and Immunology, University of Geneva Medical Center , Geneva , Switzerland
| | - Brenda R Kwak
- Department of Pathology and Immunology, University of Geneva Medical Center , Geneva , Switzerland
- Division of Cardiology, University of Geneva Medical Center , Geneva , Switzerland
| | - Domenico Bosco
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
- Department of Surgery, Cell Isolation and Transplantation Center, Geneva University Hospital , Geneva , Switzerland
| | - Marc Chanson
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Department of Pediatrics, Geneva University Hospital , Geneva , Switzerland
| | - Pierre Maechler
- Department of Cell Physiology and Metabolism, University of Geneva Medical Center , Geneva , Switzerland
- Faculty Diabetes Center, University of Geneva Medical Center , Geneva , Switzerland
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24
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Guček A, Gandasi NR, Omar-Hmeadi M, Bakke M, Døskeland SO, Tengholm A, Barg S. Fusion pore regulation by cAMP/Epac2 controls cargo release during insulin exocytosis. eLife 2019; 8:41711. [PMID: 31099751 PMCID: PMC6557626 DOI: 10.7554/elife.41711] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 04/28/2019] [Indexed: 12/20/2022] Open
Abstract
Regulated exocytosis establishes a narrow fusion pore as initial aqueous connection to the extracellular space, through which small transmitter molecules such as ATP can exit. Co-release of polypeptides and hormones like insulin requires further expansion of the pore. There is evidence that pore expansion is regulated and can fail in diabetes and neurodegenerative disease. Here, we report that the cAMP-sensor Epac2 (Rap-GEF4) controls fusion pore behavior by acutely recruiting two pore-restricting proteins, amisyn and dynamin-1, to the exocytosis site in insulin-secreting beta-cells. cAMP elevation restricts and slows fusion pore expansion and peptide release, but not when Epac2 is inactivated pharmacologically or in Epac2-/- (Rapgef4-/-) mice. Consistently, overexpression of Epac2 impedes pore expansion. Widely used antidiabetic drugs (GLP-1 receptor agonists and sulfonylureas) activate this pathway and thereby paradoxically restrict hormone release. We conclude that Epac2/cAMP controls fusion pore expansion and thus the balance of hormone and transmitter release during insulin granule exocytosis. Insulin is the hormone that signals to the body to take up sugar from the blood. Specialized cells in the pancreas – known as β-cells – release insulin after a meal. Before that, insulin molecules are stored in tiny granules inside the β-cells; these granules must fuse with the cells’ surface membranes to release their contents. The first step in this process creates a narrow pore that allows small molecules, but not the larger insulin molecules, to seep out. The pore then widens to release the insulin. Since the small molecules are known to act locally in the pancreas, it is possible that this “molecular sieve” is biologically important. Yet it is not clear how the pore widens. One of the problems for people with type 2 diabetes is that they release less insulin into the bloodstream. Two kinds of drugs used to treat these patients work by stimulating β-cells to release their insulin. One way to achieve this is by raising the levels of a small molecule called cAMP, which is well known to help prepare insulin granules for release. The cAMP molecule also seems to slow the widening of the pore, and Gucek et al. have now investigated how this happens at a molecular level. By observing individual granules of human β-cells using a special microscope, Gucek et al. could watch how different drugs affect pore widening and content release. They also saw that cAMP activated a protein called Epac2, which then recruited two other proteins – amisyn and dynamin – to the small pores. These two proteins together then closed the pore, rather than expanding it to let insulin out. Type 2 diabetes patients sometimes have high levels of amisyn in their β-cells, which could explain why they do not release enough insulin. The microscopy experiments also revealed that two common anti-diabetic drugs activate Epac2 and prevent the pores from widening, thereby counteracting their positive effect on insulin release. The combined effect is likely a shift in the balance between insulin and the locally acting small molecules. These findings suggest that two common anti-diabetic drugs activate a common mechanism that may lead to unexpected outcomes, possibly even reducing how much insulin the β-cells can release. Future studies in mice and humans will have to investigate these effects in whole organisms.
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Affiliation(s)
- Alenka Guček
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Nikhil R Gandasi
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | | | - Marit Bakke
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Sebastian Barg
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
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25
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Saunders DC, Brissova M, Phillips N, Shrestha S, Walker JT, Aramandla R, Poffenberger G, Flaherty DK, Weller KP, Pelletier J, Cooper T, Goff MT, Virostko J, Shostak A, Dean ED, Greiner DL, Shultz LD, Prasad N, Levy SE, Carnahan RH, Dai C, Sévigny J, Powers AC. Ectonucleoside Triphosphate Diphosphohydrolase-3 Antibody Targets Adult Human Pancreatic β Cells for In Vitro and In Vivo Analysis. Cell Metab 2019; 29:745-754.e4. [PMID: 30449685 PMCID: PMC6402969 DOI: 10.1016/j.cmet.2018.10.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/15/2018] [Accepted: 10/19/2018] [Indexed: 01/09/2023]
Abstract
Identification of cell-surface markers specific to human pancreatic β cells would allow in vivo analysis and imaging. Here we introduce a biomarker, ectonucleoside triphosphate diphosphohydrolase-3 (NTPDase3), that is expressed on the cell surface of essentially all adult human β cells, including those from individuals with type 1 or type 2 diabetes. NTPDase3 is expressed dynamically during postnatal human pancreas development, appearing first in acinar cells at birth, but several months later its expression declines in acinar cells while concurrently emerging in islet β cells. Given its specificity and membrane localization, we utilized an NTPDase3 antibody for purification of live human β cells as confirmed by transcriptional profiling, and, in addition, for in vivo imaging of transplanted human β cells. Thus, NTPDase3 is a cell-surface biomarker of adult human β cells, and the antibody directed to this protein should be a useful new reagent for β cell sorting, in vivo imaging, and targeting.
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Affiliation(s)
- Diane C Saunders
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37240, USA
| | - Marcela Brissova
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Neil Phillips
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Shristi Shrestha
- HudsonAlpha Institute of Biotechnology, Huntsville, AL 35806, USA
| | - John T Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37240, USA
| | - Radhika Aramandla
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Greg Poffenberger
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - David K Flaherty
- Flow Cytometry Shared Resource, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Kevin P Weller
- Flow Cytometry Shared Resource, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Julie Pelletier
- Centre de recherche du CHU de Québec - Université Laval, Québec City, QC G1V 4G2, Canada
| | - Tracy Cooper
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Matt T Goff
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - John Virostko
- Department of Diagnostic Medicine, Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA
| | - Alena Shostak
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - E Danielle Dean
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Dale L Greiner
- Department of Molecular Medicine, Diabetes Center of Excellence, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | | | - Nripesh Prasad
- HudsonAlpha Institute of Biotechnology, Huntsville, AL 35806, USA
| | - Shawn E Levy
- HudsonAlpha Institute of Biotechnology, Huntsville, AL 35806, USA
| | - Robert H Carnahan
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Chunhua Dai
- Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Jean Sévigny
- Centre de recherche du CHU de Québec - Université Laval, Québec City, QC G1V 4G2, Canada; Départment de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
| | - Alvin C Powers
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37240, USA; Department of Medicine, Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, TN 37232, USA; VA Tennessee Valley Healthcare, Nashville, TN 37212, USA.
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26
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Bauer C, Kaiser J, Sikimic J, Krippeit-Drews P, Düfer M, Drews G. ATP mediates a negative autocrine signal on stimulus-secretion coupling in mouse pancreatic β-cells. Endocrine 2019; 63:270-283. [PMID: 30229397 DOI: 10.1007/s12020-018-1731-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 08/20/2018] [Indexed: 02/07/2023]
Abstract
PURPOSE The role of ATP, which is secreted by pancreatic β-cells, is still a matter of debate. It has been postulated that extracellular ATP acts as a positive auto- or paracrine signal in β-cells amplifying insulin secretion. However, there is rising evidence that extracellular ATP may also mediate a negative signal. METHODS We evaluated whether extracellular ATP interferes with the Ca2+-mediated negative feedback mechanism that regulates oscillatory activity of β-cells. RESULTS To experimentally uncover the Ca2+-induced feedback we applied a high extracellular Ca2+ concentration. Under this condition ATP (100 µM) inhibited glucose-evoked oscillations of electrical activity and hyperpolarized the membrane potential. Furthermore, ATP acutely increased the interburst phase of Ca2+ oscillations and reduced the current through L-type Ca2+ channels. Accordingly, ATP (500 µM) decreased glucose-induced insulin secretion. The ATP effect was not mimicked by AMP, ADP, or adenosine. The use of specific agonists and antagonists and mice deficient of large conductance Ca2+-dependent K+ channels revealed that P2X, but not P2Y receptors, and Ca2+-dependent K+ channels are involved in the underlying signaling cascade induced by ATP. The effectiveness of ATP to interfere with parameters of stimulus-secretion coupling is markedly reduced at low extracellular Ca2+ concentration. CONCLUSION It is suggested that extracellular ATP which is co-secreted with insulin in a pulsatile manner during glucose-stimulated exocytosis provides a negative feedback signal driving β-cell oscillations in co-operation with Ca2+ and other signals.
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Affiliation(s)
- Cita Bauer
- Department of Pharmacology, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, Tübingen, D-72076, Germany
| | - Julia Kaiser
- Department of Pharmacology, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, Tübingen, D-72076, Germany
| | - Jelena Sikimic
- Department of Pharmacology, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, Tübingen, D-72076, Germany
| | - Peter Krippeit-Drews
- Department of Pharmacology, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, Tübingen, D-72076, Germany
| | - Martina Düfer
- Department of Pharmaceutical and Medicinal Chemistry, University of Münster, Corrensstraße 48, Münster, D-48149, Germany
| | - Gisela Drews
- Department of Pharmacology, Institute of Pharmacy, University of Tübingen, Auf der Morgenstelle 8, Tübingen, D-72076, Germany.
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27
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Abstract
Type 2 diabetes is a progressive disorder, but exactly how the progression occurs remains unknown. In this issue of Cell Metabolism, Zhang et al. (2019) present evidence that diabetes, via hyperglycemia, leads to aberrant insertion of a mitochondrial ion channel in the plasma membrane, rendering it leaky to key intracellular signaling molecules with resultant suppression of insulin secretion.
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Affiliation(s)
- Jakob G Knudsen
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LJ, UK
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford OX3 7LJ, UK; Metabolic Physiology, Department of Physiology, University of Göteborg, Box 430, SE-405 30 Göteborg, Sweden.
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28
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Xie B, Nguyen PM, Idevall-Hagren O. Feedback regulation of insulin secretion by extended synaptotagmin-1. FASEB J 2018; 33:4716-4728. [PMID: 30589572 DOI: 10.1096/fj.201801878r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endoplasmic reticulum (ER)-plasma membrane (PM) contacts are dynamic structures with important roles in the regulation of calcium (Ca2+) and lipid homeostasis. The extended synaptotagmins (E-Syts) are ER-localized lipid transport proteins that interact with PM phosphatidylinositol 4,5-bisphosphate in a Ca2+-dependent manner. E-Syts bidirectionally transfer glycerolipids, including diacylglycerol (DAG), between the 2 juxtaposed membranes, but the biologic significance of this transport is still unclear. Using insulin-secreting cells and live-cell imaging, we now show that Ca2+-triggered exocytosis of insulin granules is followed, in sequence, by PM DAG formation and E-Syt1 recruitment. E-Syt1 counteracted the depolarization-induced DAG formation through a mechanism that required both voltage-dependent Ca2+ influx and Ca2+ release from the ER. E-Syt1 knockdown resulted in prolonged accumulation of DAG in the PM, resulting in increased glucose-stimulated insulin secretion. We conclude that Ca2+-triggered exocytosis is temporally coupled to Ca2+-triggered E-Syt1 PM recruitment and removal of DAG to negatively regulate the same process.-Xie, B., Nguyen, P. M., Idevall-Hagren, O. Feedback regulation of insulin secretion by extended synaptotagmin-1.
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Affiliation(s)
- Beichen Xie
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Phuoc My Nguyen
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
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29
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Jiang WJ, Peng YC, Yang KM. Cellular signaling pathways regulating β-cell proliferation as a promising therapeutic target in the treatment of diabetes. Exp Ther Med 2018; 16:3275-3285. [PMID: 30233674 PMCID: PMC6143874 DOI: 10.3892/etm.2018.6603] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 07/27/2018] [Indexed: 12/30/2022] Open
Abstract
It is established that a decrease in β-cell number and deficiency in the function of existing β-cells contribute to type 1 and type 2 diabetes mellitus. Therefore, a major focus of current research is to identify novel methods of improving the number and function of β-cells, so as to prevent and/or postpone the development of diabetes mellitus and potentially reverse diabetes mellitus. Based on prior knowledge of the above-mentioned causes, promising therapeutic approaches may include direct transplantation of islets, implantation and subsequent induced differentiation of progenitors/stem cells to β-cells, replication of pre-existing β-cells, or activation of endogenous β-cell progenitors. More recently, with regards to cell replacement and regenerative treatment for diabetes patients, the identification of cellular signaling pathways with related genes or corresponding proteins involved in diabetes has become a topic of interest. However, the majority of pathways and molecules associated with β-cells remain unresolved, and the specialized functions of known pathways remain unclear, particularly in humans. The current article has evaluated the progress of research on pivotal cellular signaling pathways involved with β-cell proliferation and survival, and their validity for therapeutic adult β-cell regeneration in diabetes. More efforts are required to elucidate the cellular events involved in human β-cell proliferation in terms of the underlying mechanisms and functions.
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Affiliation(s)
- Wen-Juan Jiang
- Institute of Anatomy, Basic Medical College of Dali University, Dali, Yunnan 671000, P.R. China
| | - Yun-Chuan Peng
- Institute of Anatomy, Basic Medical College of Dali University, Dali, Yunnan 671000, P.R. China
| | - Kai-Ming Yang
- Institute of Anatomy, Basic Medical College of Dali University, Dali, Yunnan 671000, P.R. China
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30
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Tozzi M, Larsen AT, Lange SC, Giannuzzo A, Andersen MN, Novak I. The P2X7 receptor and pannexin-1 are involved in glucose-induced autocrine regulation in β-cells. Sci Rep 2018; 8:8926. [PMID: 29895988 PMCID: PMC5997690 DOI: 10.1038/s41598-018-27281-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 05/31/2018] [Indexed: 01/02/2023] Open
Abstract
Extracellular ATP is an important short-range signaling molecule that promotes various physiological responses virtually in all cell types, including pancreatic β-cells. It is well documented that pancreatic β-cells release ATP through exocytosis of insulin granules upon glucose stimulation. We hypothesized that glucose might stimulate ATP release through other non-vesicular mechanisms. Several purinergic receptors are found in β-cells and there is increasing evidence that purinergic signaling regulates β-cell functions and survival. One of the receptors that may be relevant is the P2X7 receptor, but its detailed role in β-cell physiology is unclear. In this study we investigated roles of the P2X7 receptor and pannexin-1 in ATP release, intracellular ATP, Ca2+ signals, insulin release and cell proliferation/survival in β-cells. Results show that glucose induces rapid release of ATP and significant fraction of release involves the P2X7 receptor and pannexin-1, both expressed in INS-1E cells, rat and mouse β-cells. Furthermore, we provide pharmacological evidence that extracellular ATP, via P2X7 receptor, stimulates Ca2+ transients and cell proliferation in INS-1E cells and insulin secretion in INS-1E cells and rat islets. These data indicate that the P2X7 receptor and pannexin-1 have important functions in β-cell physiology, and should be considered in understanding and treatment of diabetes.
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Affiliation(s)
- Marco Tozzi
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Anna T Larsen
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Sofie C Lange
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Andrea Giannuzzo
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Martin N Andersen
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Ivana Novak
- Section for Cell Biology and Physiology, August Krogh Building, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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31
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Novak I, Solini A. P2X receptor-ion channels in the inflammatory response in adipose tissue and pancreas — potential triggers in onset of type 2 diabetes? Curr Opin Immunol 2018. [DOI: 10.1016/j.coi.2018.02.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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32
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Rorsman P, Ashcroft FM. Pancreatic β-Cell Electrical Activity and Insulin Secretion: Of Mice and Men. Physiol Rev 2018; 98:117-214. [PMID: 29212789 PMCID: PMC5866358 DOI: 10.1152/physrev.00008.2017] [Citation(s) in RCA: 443] [Impact Index Per Article: 73.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/30/2017] [Accepted: 06/18/2017] [Indexed: 12/14/2022] Open
Abstract
The pancreatic β-cell plays a key role in glucose homeostasis by secreting insulin, the only hormone capable of lowering the blood glucose concentration. Impaired insulin secretion results in the chronic hyperglycemia that characterizes type 2 diabetes (T2DM), which currently afflicts >450 million people worldwide. The healthy β-cell acts as a glucose sensor matching its output to the circulating glucose concentration. It does so via metabolically induced changes in electrical activity, which culminate in an increase in the cytoplasmic Ca2+ concentration and initiation of Ca2+-dependent exocytosis of insulin-containing secretory granules. Here, we review recent advances in our understanding of the β-cell transcriptome, electrical activity, and insulin exocytosis. We highlight salient differences between mouse and human β-cells, provide models of how the different ion channels contribute to their electrical activity and insulin secretion, and conclude by discussing how these processes become perturbed in T2DM.
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Affiliation(s)
- Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom; Department of Neuroscience and Physiology, Metabolic Research Unit, Göteborg, Sweden; and Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Frances M Ashcroft
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, Churchill Hospital, Oxford, United Kingdom; Department of Neuroscience and Physiology, Metabolic Research Unit, Göteborg, Sweden; and Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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33
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Ciancetta A, O'Connor RD, Paoletta S, Jacobson KA. Demystifying P2Y 1 Receptor Ligand Recognition through Docking and Molecular Dynamics Analyses. J Chem Inf Model 2017; 57:3104-3123. [PMID: 29182323 DOI: 10.1021/acs.jcim.7b00528] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We performed a molecular modeling analysis of 100 nucleotide-like bisphosphates and 46 non-nucleotide arylurea derivatives previously reported as P2Y1R binders using the recently solved hP2Y1R structures. We initially docked the compounds at the X-ray structures and identified the binding modes of representative compounds highlighting key patterns in the structure-activity relationship (SAR). We subsequently subjected receptor complexes with selected key agonists (2MeSADP and MRS2268) and antagonists (MRS2500 and BPTU) to membrane molecular dynamics (MD) simulations (at least 200 ns run in triplicate, simulation time 0.6-1.6 μs per ligand system) while considering alternative protonation states of nucleotides. Comparing the temporal evolution of the ligand-protein interaction patterns with available site-directed mutagenesis (SDM) data and P2Y1R apo state simulation provided further SAR insights and suggested reasonable explanations for loss/gain of binding affinity as well as the most relevant charged species for nucleotide ligands. The MD analysis also predicted local conformational changes required for the receptor inactive state to accommodate nucleotide agonists.
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Affiliation(s)
- Antonella Ciancetta
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Robert D O'Connor
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Silvia Paoletta
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Kenneth A Jacobson
- Molecular Recognition Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Bethesda, Maryland 20892, United States
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Wilkaniec A, Gąssowska M, Czapski GA, Cieślik M, Sulkowski G, Adamczyk A. P2X7 receptor-pannexin 1 interaction mediates extracellular alpha-synuclein-induced ATP release in neuroblastoma SH-SY5Y cells. Purinergic Signal 2017; 13:347-361. [PMID: 28516276 PMCID: PMC5563296 DOI: 10.1007/s11302-017-9567-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 04/30/2017] [Indexed: 12/14/2022] Open
Abstract
Abnormalities of alpha-synuclein (ASN), the main component of protein deposits (Lewy bodies), were observed in Parkinson’s disease (PD), dementia with Lewy bodies, Alzheimer’s disease, and other neurodegenerative disorders. These alterations include increase in the levels of soluble ASN oligomers in the extracellular space. Numerous works have identified several mechanisms of their toxicity, including stimulation of the microglial P2X7 receptor leading to oxidative stress. While the significant role of purinergic signaling—particularly, P2 family receptors—in neurodegenerative disorders is well known, the interaction of extracellular soluble ASN with neuronal purinergic receptors is yet to be studied. Therefore, in this study, we have investigated the effect of ASN on P2 purinergic receptors and ATP-dependent signaling. We used neuroblastoma SH-SY5Y cell line and rat synaptoneurosomes treated with exogenous soluble ASN. The experiments were performed using spectrofluorometric, radiochemical, and immunochemical methods. We found the following: (i) ASN-induced intracellular free calcium mobilization in neuronal cells and nerve endings depends on the activation of purinergic P2X7 receptors; (ii) activation of P2X7 receptors leads to pannexin 1 recruitment to form an active complex responsible for ATP release; and (iii) ASN greatly decreases the activity of extracellular ecto-ATPase responsible for ATP degradation. Thus, it is concluded that purinergic receptors might be putative pharmacological targets in the molecular mechanism of extracellular ASN toxicity. Interference with P2X7 signaling seems to be a promising strategy for the prevention or therapy of PD and other neurodegenerative disorders.
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Affiliation(s)
- Anna Wilkaniec
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland.
| | - Magdalena Gąssowska
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
| | - Grzegorz A Czapski
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
| | - Magdalena Cieślik
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
| | - Grzegorz Sulkowski
- Department of Neurochemistry, Laboratory of Pathoneurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
| | - Agata Adamczyk
- Department of Cellular Signalling, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 St., 02-106, Warsaw, Poland
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Sacco F, Humphrey SJ, Cox J, Mischnik M, Schulte A, Klabunde T, Schäfer M, Mann M. Glucose-regulated and drug-perturbed phosphoproteome reveals molecular mechanisms controlling insulin secretion. Nat Commun 2016; 7:13250. [PMID: 27841257 PMCID: PMC5114537 DOI: 10.1038/ncomms13250] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 09/15/2016] [Indexed: 12/27/2022] Open
Abstract
Insulin-secreting beta cells play an essential role in maintaining physiological blood glucose levels, and their dysfunction leads to the development of diabetes. To elucidate the signalling events regulating insulin secretion, we applied a recently developed phosphoproteomics workflow. We quantified the time-resolved phosphoproteome of murine pancreatic cells following their exposure to glucose and in combination with small molecule compounds that promote insulin secretion. The quantitative phosphoproteome of 30,000 sites clustered into three main groups in concordance with the modulation of the three key kinases: PKA, PKC and CK2A. A high-resolution time course revealed key novel regulatory sites, revealing the importance of methyltransferase DNMT3A phosphorylation in the glucose response. Remarkably a significant proportion of these novel regulatory sites is significantly downregulated in diabetic islets. Control of insulin secretion is embedded in an unexpectedly broad and complex range of cellular functions, which are perturbed by drugs in multiple ways. Dysfunction in insulin secretion is a main driver of type 2 diabetes development. Here the authors monitor phosphoproteome modulation in cells stimulated with glucose and treated with drugs affecting glucose-mediated insulin secretion to reveal phosphorylation sites implicated in insulin secretion control and gene expression regulation.
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Affiliation(s)
- Francesca Sacco
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Sean J Humphrey
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Jürgen Cox
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Marcel Mischnik
- Sanofi Aventis Deutschland GmbH, R&D, LGCR, SDI, Bioinformatics, Frankfurt 65926, Germany
| | - Anke Schulte
- Sanofi Aventis Deutschland GmbH, Global Diabetes Division, R&TM, Islet Biology, Frankfurt 65926, Germany
| | - Thomas Klabunde
- Sanofi Aventis Deutschland GmbH, R&D, LGCR, SDI, Bioinformatics, Frankfurt 65926, Germany
| | - Matthias Schäfer
- Sanofi Aventis Deutschland GmbH, Global Diabetes Division, R&TM, Islet Biology, Frankfurt 65926, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
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Yan-Do R, Duong E, Manning Fox JE, Dai X, Suzuki K, Khan S, Bautista A, Ferdaoussi M, Lyon J, Wu X, Cheley S, MacDonald PE, Braun M. A Glycine-Insulin Autocrine Feedback Loop Enhances Insulin Secretion From Human β-Cells and Is Impaired in Type 2 Diabetes. Diabetes 2016; 65:2311-21. [PMID: 27207556 DOI: 10.2337/db15-1272] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 04/26/2016] [Indexed: 11/13/2022]
Abstract
The secretion of insulin from pancreatic islet β-cells is critical for glucose homeostasis. Disrupted insulin secretion underlies almost all forms of diabetes, including the most common form, type 2 diabetes (T2D). The control of insulin secretion is complex and affected by circulating nutrients, neuronal inputs, and local signaling. In the current study, we examined the contribution of glycine, an amino acid and neurotransmitter that activates ligand-gated Cl(-) currents, to insulin secretion from islets of human donors with and without T2D. We find that human islet β-cells express glycine receptors (GlyR), notably the GlyRα1 subunit, and the glycine transporter (GlyT) isoforms GlyT1 and GlyT2. β-Cells exhibit significant glycine-induced Cl(-) currents that promote membrane depolarization, Ca(2+) entry, and insulin secretion from β-cells from donors without T2D. However, GlyRα1 expression and glycine-induced currents are reduced in β-cells from donors with T2D. Glycine is actively cleared by the GlyT expressed within β-cells, which store and release glycine that acts in an autocrine manner. Finally, a significant positive relationship exists between insulin and GlyR, because insulin enhances the glycine-activated current in a phosphoinositide 3-kinase-dependent manner, a positive feedback loop that we find is completely lost in β-cells from donors with T2D.
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Affiliation(s)
- Richard Yan-Do
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Eric Duong
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Jocelyn E Manning Fox
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Xiaoqing Dai
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Kunimasa Suzuki
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Shara Khan
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Austin Bautista
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Mourad Ferdaoussi
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - James Lyon
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Xichen Wu
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Stephen Cheley
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Patrick E MacDonald
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Matthias Braun
- Department of Pharmacology and Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
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Wuttke A, Yu Q, Tengholm A. Autocrine Signaling Underlies Fast Repetitive Plasma Membrane Translocation of Conventional and Novel Protein Kinase C Isoforms in β Cells. J Biol Chem 2016; 291:14986-95. [PMID: 27226533 PMCID: PMC4946917 DOI: 10.1074/jbc.m115.698456] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Indexed: 01/08/2023] Open
Abstract
PKC signaling has been implicated in the regulation of many cell functions, including metabolism, cell death, proliferation, and secretion. Activation of conventional and novel PKC isoforms is associated with their Ca2+- and/or diacylglycerol (DAG)-dependent translocation to the plasma membrane. In β cells, exocytosis of insulin granules evokes brief (<10 s) local DAG elevations (“spiking”) at the plasma membrane because of autocrine activation of P2Y1 purinoceptors by ATP co-released with insulin. Using total internal reflection microscopy, fluorescent protein-tagged PKCs, and signaling biosensors, we investigated whether DAG spiking causes membrane recruitment of PKCs and whether different classes of PKCs show characteristic responses. Glucose stimulation of MIN6 cells triggered DAG spiking with concomitant repetitive translocation of the novel isoforms PKCδ, PKCϵ, and PKCη. The conventional PKCα, PKCβI, and PKCβII isoforms showed a more complex pattern with both rapid and slow translocation. K+ depolarization-induced PKCϵ translocation entirely mirrored DAG spiking, whereas PKCβI translocation showed a sustained component, reflecting the subplasma membrane Ca2+ concentration ([Ca2+]pm), with additional effect during DAG spikes. Interference with DAG spiking by purinoceptor inhibition prevented intermittent translocation of PKCs and reduced insulin secretion but did not affect [Ca2+]pm elevation or sustained PKCβI translocation. The muscarinic agonist carbachol induced pronounced transient PKCβI translocation and sustained recruitment of PKCϵ. When rise of [Ca2+]pm was prevented, the carbachol-induced DAG and PKCϵ responses were somewhat reduced, but PKCβI translocation was completely abolished. We conclude that exocytosis-induced DAG spikes efficiently recruit both conventional and novel PKCs to the β cell plasma membrane. PKC signaling is thus implicated in autocrine regulation of β cell function.
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Affiliation(s)
- Anne Wuttke
- From the Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, 75123 Uppsala, Sweden
| | - Qian Yu
- From the Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, 75123 Uppsala, Sweden
| | - Anders Tengholm
- From the Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, 75123 Uppsala, Sweden
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38
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Zimmermann H. Extracellular ATP and other nucleotides-ubiquitous triggers of intercellular messenger release. Purinergic Signal 2015; 12:25-57. [PMID: 26545760 DOI: 10.1007/s11302-015-9483-2] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 10/29/2015] [Indexed: 12/21/2022] Open
Abstract
Extracellular nucleotides, and ATP in particular, are cellular signal substances involved in the control of numerous (patho)physiological mechanisms. They provoke nucleotide receptor-mediated mechanisms in select target cells. But nucleotides can considerably expand their range of action. They function as primary messengers in intercellular communication by stimulating the release of other extracellular messenger substances. These in turn activate additional cellular mechanisms through their own receptors. While this applies also to other extracellular messengers, its omnipresence in the vertebrate organism is an outstanding feature of nucleotide signaling. Intercellular messenger substances released by nucleotides include neurotransmitters, hormones, growth factors, a considerable variety of other proteins including enzymes, numerous cytokines, lipid mediators, nitric oxide, and reactive oxygen species. Moreover, nucleotides activate or co-activate growth factor receptors. In the case of hormone release, the initially paracrine or autocrine nucleotide-mediated signal spreads through to the entire organism. The examples highlighted in this commentary suggest that acting as ubiquitous triggers of intercellular messenger release is one of the major functional roles of extracellular nucleotides. While initiation of messenger release by nucleotides has been unraveled in many contexts, it may have been overlooked in others. It can be anticipated that additional nucleotide-driven messenger functions will be uncovered with relevance for both understanding physiology and development of therapy.
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Affiliation(s)
- Herbert Zimmermann
- Institute of Cell Biology and Neuroscience, Molecular and Cellular Neurobiology, Goethe University, Max-von-Laue-Str. 13, Frankfurt am Main, Germany.
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Arrojo e Drigo R, Ali Y, Diez J, Srinivasan DK, Berggren PO, Boehm BO. New insights into the architecture of the islet of Langerhans: a focused cross-species assessment. Diabetologia 2015. [PMID: 26215305 DOI: 10.1007/s00125-015-3699-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The human genome project and its search for factors underlying human diseases has fostered a major human research effort. Therefore, unsurprisingly, in recent years we have observed an increasing number of studies on human islet cells, including disease approaches focusing on type 1 and type 2 diabetes. Yet, the field of islet and diabetes research relies on the legacy of rodent-based investigations, which have proven difficult to translate to humans, particularly in type 1 diabetes. Whole islet physiology and pathology may differ between rodents and humans, and thus a comprehensive cross-species as well as species-specific view on islet research is much needed. In this review we summarise the current knowledge of interspecies islet cytoarchitecture, and discuss its potential impact on islet function and future perspectives in islet pathophysiology research.
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Affiliation(s)
- Rafael Arrojo e Drigo
- Lee Kong Chian School of Medicine, Nanyang Technological University, 50 Nanyang Drive, Research Techno Plaza, Level 4, 637 553, Singapore, Singapore
| | - Yusuf Ali
- Lee Kong Chian School of Medicine, Nanyang Technological University, 50 Nanyang Drive, Research Techno Plaza, Level 4, 637 553, Singapore, Singapore
| | - Juan Diez
- Lee Kong Chian School of Medicine, Nanyang Technological University, 50 Nanyang Drive, Research Techno Plaza, Level 4, 637 553, Singapore, Singapore
| | - Dinesh Kumar Srinivasan
- Lee Kong Chian School of Medicine, Nanyang Technological University, 50 Nanyang Drive, Research Techno Plaza, Level 4, 637 553, Singapore, Singapore
| | - Per-Olof Berggren
- Lee Kong Chian School of Medicine, Nanyang Technological University, 50 Nanyang Drive, Research Techno Plaza, Level 4, 637 553, Singapore, Singapore.
- Imperial College London, London, UK.
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska University Hospital L1, Karolinska Institutet, SE-171 76, Stockholm, Sweden.
| | - Bernhard O Boehm
- Lee Kong Chian School of Medicine, Nanyang Technological University, 50 Nanyang Drive, Research Techno Plaza, Level 4, 637 553, Singapore, Singapore.
- Imperial College London, London, UK.
- Department of Internal Medicine 1, Ulm University Medical Centre, Ulm, Germany.
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Tengholm A. Purinergic P2Y1 receptors take centre stage in autocrine stimulation of human beta cells. Diabetologia 2014; 57:2436-9. [PMID: 25277952 DOI: 10.1007/s00125-014-3392-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 09/10/2014] [Indexed: 12/20/2022]
Abstract
Insulin secretory vesicles contain high concentrations of adenine nucleotides, which are co-released with insulin during exocytosis. There is strong evidence that ATP and ADP serve as autocrine messengers in pancreatic beta cells, but the functional effects and detailed mechanisms of action are under debate. In this issue of Diabetologia, Khan and colleagues (DOI: 10.1007/s00125-014-3368-8 ) present the results of their study of autocrine purinergic signalling in isolated human beta cells. Using a combination of electrophysiological techniques, Ca(2+) imaging and measurements of insulin secretion, it is demonstrated that voltage-dependent Ca(2+) influx triggers release of ATP/ADP, which activates purinergic receptors of the Gq/11-coupled P2Y1 isoform. Activation of these receptors leads to membrane depolarisation and phospholipase C-mediated mobilisation of Ca(2+) from endoplasmic reticulum stores, which amplifies the exocytosis-triggering Ca(2+) signal. In contrast, there is little evidence for involvement of ionotropic P2X receptors in the autocrine stimulation of human beta cells. This commentary discusses these findings as well as various functional and therapeutic implications of the complex purinergic signalling network in the pancreatic islet.
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Affiliation(s)
- Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23, Uppsala, Sweden,
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