1
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Tsvilovskyy V, Ottenheijm R, Kriebs U, Schütz A, Diakopoulos KN, Jha A, Bildl W, Wirth A, Böck J, Jaślan D, Ferro I, Taberner FJ, Kalinina O, Hildebrand S, Wissenbach U, Weissgerber P, Vogt D, Eberhagen C, Mannebach S, Berlin M, Kuryshev V, Schumacher D, Philippaert K, Camacho-Londoño JE, Mathar I, Dieterich C, Klugbauer N, Biel M, Wahl-Schott C, Lipp P, Flockerzi V, Zischka H, Algül H, Lechner SG, Lesina M, Grimm C, Fakler B, Schulte U, Muallem S, Freichel M. OCaR1 endows exocytic vesicles with autoregulatory competence by preventing uncontrolled Ca2+ release, exocytosis, and pancreatic tissue damage. J Clin Invest 2024; 134:e169428. [PMID: 38557489 PMCID: PMC10977991 DOI: 10.1172/jci169428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 02/13/2024] [Indexed: 04/04/2024] Open
Abstract
Regulated exocytosis is initiated by increased Ca2+ concentrations in close spatial proximity to secretory granules, which is effectively prevented when the cell is at rest. Here we showed that exocytosis of zymogen granules in acinar cells was driven by Ca2+ directly released from acidic Ca2+ stores including secretory granules through NAADP-activated two-pore channels (TPCs). We identified OCaR1 (encoded by Tmem63a) as an organellar Ca2+ regulator protein integral to the membrane of secretory granules that controlled Ca2+ release via inhibition of TPC1 and TPC2 currents. Deletion of OCaR1 led to extensive Ca2+ release from NAADP-responsive granules under basal conditions as well as upon stimulation of GPCR receptors. Moreover, OCaR1 deletion exacerbated the disease phenotype in murine models of severe and chronic pancreatitis. Our findings showed OCaR1 as a gatekeeper of Ca2+ release that endows NAADP-sensitive secretory granules with an autoregulatory mechanism preventing uncontrolled exocytosis and pancreatic tissue damage.
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Affiliation(s)
- Volodymyr Tsvilovskyy
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Roger Ottenheijm
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Ulrich Kriebs
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Aline Schütz
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Kalliope Nina Diakopoulos
- Comprehensive Cancer Center München, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Archana Jha
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, USA
| | - Wolfgang Bildl
- Institute for Physiology, University of Freiburg, Freiburg, Germany
| | - Angela Wirth
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Julia Böck
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Dawid Jaślan
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Irene Ferro
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Francisco J. Taberner
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández–Consejo Superior de Investigaciones Científicas, Sant Joan d’Alacant, Spain
| | - Olga Kalinina
- Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany
| | - Staffan Hildebrand
- Institut für Pharmakologie und Toxikologie, Universität Bonn, Bonn, Germany
| | - Ulrich Wissenbach
- Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Petra Weissgerber
- Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Dominik Vogt
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Carola Eberhagen
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Stefanie Mannebach
- Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Michael Berlin
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | - Vladimir Kuryshev
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Dagmar Schumacher
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Koenraad Philippaert
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, Heidelberg, Germany
| | | | - Ilka Mathar
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Christoph Dieterich
- University Hospital Heidelberg, Department of Medicine III: Cardiology, Angiology and Pneumology, Heidelberg, Germany
| | - Norbert Klugbauer
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie, Fakultät für Medizin, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPS-M) and Center for Drug Research, Department of Pharmacy, Ludwig-Maximilians-Universität München, and DZHK (German Centre for Cardiovascular Research), partner site Munich Heart Alliance, Munich, Germany
| | - Christian Wahl-Schott
- Walter Brendel Centre of Experimental Medicine, Biomedical Center, Institute of Cardiovascular Physiology and Pathophysiology, Medical Faculty, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Peter Lipp
- Institute for Molecular Cell Biology, Center for Molecular Signaling (PZMS), Universität des Saarlandes, Homburg, Germany
| | - Veit Flockerzi
- Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, Homburg, Germany
| | - Hans Zischka
- Institute of Molecular Toxicology and Pharmacology, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Toxicology and Environmental Hygiene, Technical University Munich, School of Medicine, Munich, Germany
| | - Hana Algül
- Comprehensive Cancer Center München, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Stefan G. Lechner
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Marina Lesina
- Comprehensive Cancer Center München, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Christian Grimm
- Walther-Straub-Institut für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, Munich, Germany
- Immunology, Infection and Pandemic Research (IIP), Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Munich, Germany
| | - Bernd Fakler
- Institute for Physiology, University of Freiburg, Freiburg, Germany
| | - Uwe Schulte
- Institute for Physiology, University of Freiburg, Freiburg, Germany
| | - Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, USA
| | - Marc Freichel
- Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
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2
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Petersen OH. Watching Living Cells in Action in the Exocrine Pancreas: The Palade Prize Lecture. FUNCTION 2022; 4:zqac061. [PMID: 36606242 PMCID: PMC9809903 DOI: 10.1093/function/zqac061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/04/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
George Palade's pioneering electron microscopical studies of the pancreatic acinar cell revealed the intracellular secretory pathway from the rough endoplasmic reticulum at the base of the cell to the zymogen granules in the apical region. Palade also described for the first time the final stage of exocytotic enzyme secretion into the acinar lumen. The contemporary studies of the mechanism by which secretion is acutely controlled, and how the pancreas is destroyed in the disease acute pancreatitis, rely on monitoring molecular events in the various identified pancreatic cell types in the living pancreas. These studies have been carried out with the help of high-resolution fluorescence recordings, often in conjunction with patch clamp current measurements. In such studies we have gained much detailed information about the regulatory events in the exocrine pancreas in health as well as disease, and new therapeutic opportunities have been revealed.
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Affiliation(s)
- Ole H Petersen
- School of Biosciences, Sir Martin Evans Building, Cardiff University, Wales, CF10 3AX, UK
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3
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Diszházi G, Magyar ZÉ, Lisztes E, Tóth-Molnár E, Nánási PP, Vennekens R, Tóth BI, Almássy J. TRPM4 links calcium signaling to membrane potential in pancreatic acinar cells. J Biol Chem 2021; 297:101015. [PMID: 34329682 PMCID: PMC8371206 DOI: 10.1016/j.jbc.2021.101015] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 07/22/2021] [Accepted: 07/26/2021] [Indexed: 01/02/2023] Open
Abstract
Transient receptor potential cation channel subfamily M member 4 (TRPM4) is a Ca2+-activated nonselective cation channel that mediates membrane depolarization. Although, a current with the hallmarks of a TRPM4-mediated current has been previously reported in pancreatic acinar cells (PACs), the role of TRPM4 in the regulation of acinar cell function has not yet been explored. In the present study, we identify this TRPM4 current and describe its role in context of Ca2+ signaling of PACs using pharmacological tools and TRPM4-deficient mice. We found a significant Ca2+-activated cation current in PACs that was sensitive to the TRPM4 inhibitors 9-phenanthrol and 4-chloro-2-[[2-(2-chlorophenoxy)acetyl]amino]benzoic acid (CBA). We demonstrated that the CBA-sensitive current was responsible for a Ca2+-dependent depolarization of PACs from a resting membrane potential of −44.4 ± 2.9 to −27.7 ± 3 mV. Furthermore, we showed that Ca2+ influx was higher in the TRPM4 KO- and CBA-treated PACs than in control cells. As hormone-induced repetitive Ca2+ transients partially rely on Ca2+ influx in PACs, the role of TRPM4 was also assessed on Ca2+ oscillations elicited by physiologically relevant concentrations of the cholecystokinin analog cerulein. These data show that the amplitude of Ca2+ signals was significantly higher in TRPM4 KO than in control PACs. Our results suggest that PACs are depolarized by TRPM4 currents to an extent that results in a significant reduction of the inward driving force for Ca2+. In conclusion, TRPM4 links intracellular Ca2+ signaling to membrane potential as a negative feedback regulator of Ca2+ entry in PACs.
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Affiliation(s)
- Gyula Diszházi
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zsuzsanna É Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Erika Lisztes
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Edit Tóth-Molnár
- Department of Ophthalmology, University of Szeged, Szeged, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Rudi Vennekens
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, Faculty of Medicine, TRP Research Platform Leuven, VIB Center for Brain and Disease Research, KU Leuven, Leuven, Belgium
| | - Balázs I Tóth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Almássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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4
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KRAP tethers IP 3 receptors to actin and licenses them to evoke cytosolic Ca 2+ signals. Nat Commun 2021; 12:4514. [PMID: 34301929 PMCID: PMC8302619 DOI: 10.1038/s41467-021-24739-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 07/01/2021] [Indexed: 02/06/2023] Open
Abstract
Regulation of IP3 receptors (IP3Rs) by IP3 and Ca2+ allows regenerative Ca2+ signals, the smallest being Ca2+ puffs, which arise from coordinated openings of a few clustered IP3Rs. Cells express thousands of mostly mobile IP3Rs, yet Ca2+ puffs occur at a few immobile IP3R clusters. By imaging cells with endogenous IP3Rs tagged with EGFP, we show that KRas-induced actin-interacting protein (KRAP) tethers IP3Rs to actin beneath the plasma membrane. Loss of KRAP abolishes Ca2+ puffs and the global increases in cytosolic Ca2+ concentration evoked by more intense stimulation. Over-expressing KRAP immobilizes additional IP3R clusters and results in more Ca2+ puffs and larger global Ca2+ signals. Endogenous KRAP determines which IP3Rs will respond: it tethers IP3R clusters to actin alongside sites where store-operated Ca2+ entry occurs, licenses IP3Rs to evoke Ca2+ puffs and global cytosolic Ca2+ signals, implicates the actin cytoskeleton in IP3R regulation and may allow local activation of Ca2+ entry.
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5
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Petersen OH, Gerasimenko JV, Gerasimenko OV, Gryshchenko O, Peng S. The roles of calcium and ATP in the physiology and pathology of the exocrine pancreas. Physiol Rev 2021; 101:1691-1744. [PMID: 33949875 DOI: 10.1152/physrev.00003.2021] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
This review deals with the roles of calcium ions and ATP in the control of the normal functions of the different cell types in the exocrine pancreas as well as the roles of these molecules in the pathophysiology of acute pancreatitis. Repetitive rises in the local cytosolic calcium ion concentration in the apical part of the acinar cells not only activate exocytosis but also, via an increase in the intramitochondrial calcium ion concentration, stimulate the ATP formation that is needed to fuel the energy-requiring secretion process. However, intracellular calcium overload, resulting in a global sustained elevation of the cytosolic calcium ion concentration, has the opposite effect of decreasing mitochondrial ATP production, and this initiates processes that lead to necrosis. In the last few years it has become possible to image calcium signaling events simultaneously in acinar, stellate, and immune cells in intact lobules of the exocrine pancreas. This has disclosed processes by which these cells interact with each other, particularly in relation to the initiation and development of acute pancreatitis. By unraveling the molecular mechanisms underlying this disease, several promising therapeutic intervention sites have been identified. This provides hope that we may soon be able to effectively treat this often fatal disease.
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Affiliation(s)
- Ole H Petersen
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | | | | | | | - Shuang Peng
- Department of Pathophysiology, Key Laboratory of State Administration of Traditional Chinese Medicine of the People's Republic of China, School of Medicine, Jinan University, Guangzhou, Guangdong, People's Republic of China
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6
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Petersen OH. Kafka and Asking the Right Question at the Right Time. FUNCTION (OXFORD, ENGLAND) 2021; 2:zqab013. [PMID: 35330819 PMCID: PMC8788746 DOI: 10.1093/function/zqab013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Ole H Petersen
- School of Biosciences, Cardiff University, Wales, CF14 0ES, UK,Corresponding author: E-mail:
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7
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Sneyd J, Vera-Sigüenza E, Rugis J, Pages N, Yule DI. Calcium Dynamics and Water Transport in Salivary Acinar Cells. Bull Math Biol 2021; 83:31. [PMID: 33594615 PMCID: PMC8018713 DOI: 10.1007/s11538-020-00841-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 11/25/2020] [Indexed: 01/07/2023]
Abstract
Saliva is secreted from the acinar cells of the salivary glands, using mechanisms that are similar to other types of water-transporting epithelial cells. Using a combination of theoretical and experimental techniques, over the past 20 years we have continually developed and modified a quantitative model of saliva secretion, and how it is controlled by the dynamics of intracellular calcium. However, over approximately the past 5 years there have been significant developments both in our understanding of the underlying mechanisms and in the way these mechanisms should best be modelled. Here, we review the traditional understanding of how saliva is secreted, and describe how our work has suggested important modifications to this traditional view. We end with a brief description of the most recent data from living animals and discuss how this is now contributing to yet another iteration of model construction and experimental investigation.
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Affiliation(s)
- James Sneyd
- Department of Mathematics, The University of Auckland, Level 2, Building 303, 38 Princes Street, Auckland, New Zealand.
| | | | | | | | - David I Yule
- School of Medicine and Dentistry, University of Rochester Medical Center, 601 Elmwood Ave, Box 711, Rochester, NY, USA
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8
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Cytosolic and intra-organellar Ca2+ oscillations: mechanisms and function. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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9
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The role of Ca2+ signalling in the physiology and pathophysiology of exocrine pancreas. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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10
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Petersen OH, Petersen CC. In Memoriam Sir Michael Berridge 1938 - 2020. Cell Calcium 2020; 88:102209. [PMID: 32353559 DOI: 10.1016/j.ceca.2020.102209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 11/18/2022]
Abstract
The article is an 'In Memoriam' article honouring the memory of Sir Michael Berridge.
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Affiliation(s)
- Ole H Petersen
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, Wales, UK.
| | - Carl Ch Petersen
- Laboratory of Sensory Processing, Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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11
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Pages N, Vera-Sigüenza E, Rugis J, Kirk V, Yule DI, Sneyd J. A Model of [Formula: see text] Dynamics in an Accurate Reconstruction of Parotid Acinar Cells. Bull Math Biol 2019; 81:1394-1426. [PMID: 30644065 PMCID: PMC6449190 DOI: 10.1007/s11538-018-00563-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 12/21/2018] [Indexed: 01/23/2023]
Abstract
We have constructed a spatiotemporal model of [Formula: see text] dynamics in parotid acinar cells, based on new data about the distribution of inositol trisphophate receptors (IPR). The model is solved numerically on a mesh reconstructed from images of a cluster of parotid acinar cells. In contrast to our earlier model (Sneyd et al. in J Theor Biol 419:383-393. https://doi.org/10.1016/j.jtbi.2016.04.030 , 2017b), which cannot generate realistic [Formula: see text] oscillations with the new data on IPR distribution, our new model reproduces the [Formula: see text] dynamics observed in parotid acinar cells. This model is then coupled with a fluid secretion model described in detail in a companion paper: A mathematical model of fluid transport in an accurate reconstruction of a parotid acinar cell (Vera-Sigüenza et al. in Bull Math Biol. https://doi.org/10.1007/s11538-018-0534-z , 2018b). Based on the new measurements of IPR distribution, we show that Class I models (where [Formula: see text] oscillations can occur at constant [[Formula: see text]]) can produce [Formula: see text] oscillations in parotid acinar cells, whereas Class II models (where [[Formula: see text]] needs to oscillate in order to produce [Formula: see text] oscillations) are unlikely to do so. In addition, we demonstrate that coupling fluid flow secretion with the [Formula: see text] signalling model changes the dynamics of the [Formula: see text] oscillations significantly, which indicates that [Formula: see text] dynamics and fluid flow cannot be accurately modelled independently. Further, we determine that an active propagation mechanism based on calcium-induced calcium release channels is needed to propagate the [Formula: see text] wave from the apical region to the basal region of the acinar cell.
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Affiliation(s)
- Nathan Pages
- Department of Mathematics, The University of Auckland, 38 Princes Street, Auckland 1010, New Zealand
| | - Elías Vera-Sigüenza
- Department of Mathematics, The University of Auckland, 38 Princes Street, Auckland 1010, New Zealand
| | - John Rugis
- Department of Mathematics, The University of Auckland, 38 Princes Street, Auckland 1010, New Zealand
| | - Vivien Kirk
- Department of Mathematics, The University of Auckland, 38 Princes Street, Auckland 1010, New Zealand
| | - David I. Yule
- University of Rochester Medical Center, School of Medicine and Dentistry, 601 Elmwood Ave, Box 711, Rochester NY, United States of America
| | - James Sneyd
- Department of Mathematics, The University of Auckland, 38 Princes Street, Auckland 1010, New Zealand
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12
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Williams JA. Cholecystokinin (CCK) Regulation of Pancreatic Acinar Cells: Physiological Actions and Signal Transduction Mechanisms. Compr Physiol 2019; 9:535-564. [PMID: 30873601 DOI: 10.1002/cphy.c180014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Pancreatic acinar cells synthesize and secrete about 20 digestive enzymes and ancillary proteins with the processes that match the supply of these enzymes to their need in digestion being regulated by a number of hormones (CCK, secretin and insulin), neurotransmitters (acetylcholine and VIP) and growth factors (EGF and IGF). Of these regulators, one of the most important and best studied is the gastrointestinal hormone, cholecystokinin (CCK). Furthermore, the acinar cell has become a model for seven transmembrane, heterotrimeric G protein coupled receptors to regulate multiple processes by distinct signal transduction cascades. In this review, we briefly describe the chemistry and physiology of CCK and then consider the major physiological effects of CCK on pancreatic acinar cells. The majority of the review is devoted to the physiologic signaling pathways activated by CCK receptors and heterotrimeric G proteins and the functions they affect. The pathways covered include the traditional second messenger pathways PLC-IP3-Ca2+ , DAG-PKC, and AC-cAMP-PKA/EPAC that primarily relate to secretion. Then there are the protein-protein interaction pathways Akt-mTOR-S6K, the three major MAPK pathways (ERK, JNK, and p38 MAPK), and Ca2+ -calcineurin-NFAT pathways that primarily regulate non-secretory processes including biosynthesis and growth, and several miscellaneous pathways that include the Rho family small G proteins, PKD, FAK, and Src that may regulate both secretory and nonsecretory processes but are not as well understood. © 2019 American Physiological Society. Compr Physiol 9:535-564, 2019.
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Affiliation(s)
- John A Williams
- University of Michigan, Departments of Molecular & Integrative Physiology and Internal Medicine (Gastroenterology), Ann Arbor, Michigan, USA
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13
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Miyamoto A, Mikoshiba K. A novel multi lines analysis tool of Ca 2+ dynamics reveals the nonuniformity of Ca 2+ propagation. Cell Calcium 2019; 78:76-80. [PMID: 30669073 DOI: 10.1016/j.ceca.2019.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 12/15/2018] [Accepted: 01/03/2019] [Indexed: 01/01/2023]
Abstract
Extracellular stimuli evoke a robust increase in the concentration of intracellular Ca2+ ([Ca2+]c) throughout the cell to trigger various cellular responses, such as gene expression and apoptosis. This robust expansion of [Ca2+]c is called Ca2+ propagation. To date, it is thought that intracellular second messengers, such as inositol 1,4,5-trisphosphate (IP3) and intracellular Ca2+, and clusters of IP3 receptors (IP3Rs) regulate Ca2+ propagation. However, little is known about how the elevation in the [Ca2+]c spreads throughout the cell, especially in non-polar cell, including HeLa cell. In this study, we developed a novel multi lines analysis tool. This tool revealed that the velocity of Ca2+ propagation was inconstant throughout cell and local concentration of intracellular Ca2+ did not contribute to the velocity of Ca2+ propagation. Our results suggest that intracellular Ca2+ propagation is not merely the result of diffusion of intracellular Ca2+, and that, on the contrary, intracellular Ca2+ propagation seems to be regulated by more complicated processes.
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Affiliation(s)
- Akitoshi Miyamoto
- Laboratory for Developmental Neurobiology, Center for Brain Science, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama, Japan; Laboratory of Single-Molecule Cell Biology, Kyoto University Graduate School of Biostudies, Kyoto, Japan.
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, Center for Brain Science, RIKEN, 2-1 Hirosawa, Wako-shi, Saitama, Japan.
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14
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Peng S, Gerasimenko JV, Tsugorka T, Gryshchenko O, Samarasinghe S, Petersen OH, Gerasimenko OV. Calcium and adenosine triphosphate control of cellular pathology: asparaginase-induced pancreatitis elicited via protease-activated receptor 2. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0423. [PMID: 27377732 PMCID: PMC4938023 DOI: 10.1098/rstb.2015.0423] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2016] [Indexed: 12/16/2022] Open
Abstract
Exocytotic secretion of digestive enzymes from pancreatic acinar cells is elicited by physiological cytosolic Ca2+ signals, occurring as repetitive short-lasting spikes largely confined to the secretory granule region, that stimulate mitochondrial adenosine triphosphate (ATP) production. By contrast, sustained global cytosolic Ca2+ elevations decrease ATP levels and cause necrosis, leading to the disease acute pancreatitis (AP). Toxic Ca2+ signals can be evoked by products of alcohol and fatty acids as well as bile acids. Here, we have investigated the mechanism by which l-asparaginase evokes AP. Asparaginase is an essential element in the successful treatment of acute lymphoblastic leukaemia, the most common type of cancer affecting children, but AP is a side-effect occurring in about 5–10% of cases. Like other pancreatitis-inducing agents, asparaginase evoked intracellular Ca2+ release followed by Ca2+ entry and also substantially reduced Ca2+ extrusion because of decreased intracellular ATP levels. The toxic Ca2+ signals caused extensive necrosis. The asparaginase-induced pathology depended on protease-activated receptor 2 and its inhibition prevented the toxic Ca2+ signals and necrosis. We tested the effects of inhibiting the Ca2+ release-activated Ca2+ entry by the Ca2+ channel inhibitor GSK-7975A. This markedly reduced asparaginase-induced Ca2+ entry and also protected effectively against the development of necrosis. This article is part of the themed issue ‘Evolution brings Ca2+ and ATP together to control life and death’.
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Affiliation(s)
- Shuang Peng
- Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, UK Department of Pathophysiology, Medical College, Jinan University, Guangzhou 510632, People's Republic of China
| | - Julia V Gerasimenko
- Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, UK
| | - Tatiana Tsugorka
- Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, UK
| | - Oleksiy Gryshchenko
- Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, UK Bogomoletz Institute of Physiology, Kiev 01024, Ukraine
| | - Sujith Samarasinghe
- Great Ormond Street Hospital for Children NHS Foundation Trust, Great Ormond Street, London WC1N 3JH, UK
| | - Ole H Petersen
- Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, UK Systems Immunity Research Institute, Cardiff University, Cardiff CF14 4XN, Wales, UK
| | - Oleg V Gerasimenko
- Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3AX, Wales, UK
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15
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Keebler MV, Taylor CW. Endogenous signalling pathways and caged IP 3 evoke Ca 2+ puffs at the same abundant immobile intracellular sites. J Cell Sci 2017; 130:3728-3739. [PMID: 28893841 PMCID: PMC5702060 DOI: 10.1242/jcs.208520] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/04/2017] [Indexed: 12/18/2022] Open
Abstract
The building blocks of intracellular Ca2+ signals evoked by inositol 1,4,5-trisphosphate receptors (IP3Rs) are Ca2+ puffs, transient focal increases in Ca2+ concentration that reflect the opening of small clusters of IP3Rs. We use total internal reflection fluorescence microscopy and automated analyses to detect Ca2+ puffs evoked by photolysis of caged IP3 or activation of endogenous muscarinic receptors with carbachol in human embryonic kidney 293 cells. Ca2+ puffs evoked by carbachol initiated at an estimated 65±7 sites/cell, and the sites remained immobile for many minutes. Photolysis of caged IP3 evoked Ca2+ puffs at a similar number of sites (100±35). Increasing the carbachol concentration increased the frequency of Ca2+ puffs without unmasking additional Ca2+ release sites. By measuring responses to sequential stimulation with carbachol or photolysed caged IP3, we established that the two stimuli evoked Ca2+ puffs at the same sites. We conclude that IP3-evoked Ca2+ puffs initiate at numerous immobile sites and the sites become more likely to fire as the IP3 concentration increases; there is no evidence that endogenous signalling pathways selectively deliver IP3 to specific sites. Summary: Ca2+ puffs are the building blocks for IP3-evoked Ca2+ signals. Ca2+ puffs evoked by caged IP3 or via endogenous signalling pathways initiate at the same fixed intracellular sites.
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Affiliation(s)
- Michael V Keebler
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Colin W Taylor
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
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16
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Petersen OH, Courjaret R, Machaca K. Ca 2+ tunnelling through the ER lumen as a mechanism for delivering Ca 2+ entering via store-operated Ca 2+ channels to specific target sites. J Physiol 2017; 595:2999-3014. [PMID: 28181236 PMCID: PMC5430212 DOI: 10.1113/jp272772] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 01/05/2017] [Indexed: 01/02/2023] Open
Abstract
Ca2+ signalling is perhaps the most universal and versatile mechanism regulating a wide range of cellular processes. Because of the many different calcium‐binding proteins distributed throughout cells, signalling precision requires localized rises in the cytosolic Ca2+ concentration. In electrically non‐excitable cells, for example epithelial cells, this is achieved by primary release of Ca2+ from the endoplasmic reticulum via Ca2+ release channels placed close to the physiological target. Because any rise in the cytosolic Ca2+ concentration activates Ca2+ extrusion, and in order for cells not to run out of Ca2+, there is a need for compensatory Ca2+ uptake from the extracellular fluid. This Ca2+ uptake occurs through a process known as store‐operated Ca2+ entry. Ideally Ca2+ entering the cell should not diffuse to the target site through the cytosol, as this would potentially activate undesirable processes. Ca2+ tunnelling through the lumen of the endoplasmic reticulum is a mechanism for delivering Ca2+ entering via store‐operated Ca2+ channels to specific target sites, and this process has been described in considerable detail in pancreatic acinar cells and oocytes. Here we review the most important evidence and present a generalized concept.
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Affiliation(s)
- Ole H Petersen
- MRC Group, School of Biosciences and Systems Immunity Research Institute, Cardiff University, Cardiff, CF10 3AX, UK
| | - Raphael Courjaret
- Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, PO Box 24144, Doha, Qatar
| | - Khaled Machaca
- Department of Physiology and Biophysics, Weill Cornell Medicine Qatar, Education City, Qatar Foundation, PO Box 24144, Doha, Qatar
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17
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Darbandi S, Darbandi M, Khorshid HRK, Sadeghi MR, Al-Hasani S, Agarwal A, Shirazi A, Heidari M, Akhondi MM. Experimental strategies towards increasing intracellular mitochondrial activity in oocytes: A systematic review. Mitochondrion 2016; 30:8-17. [PMID: 27234976 DOI: 10.1016/j.mito.2016.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/04/2016] [Accepted: 05/20/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE The mitochondrial complement is critical in sustaining the earliest stages of life. To improve the Assisted Reproductive Technology (ART), current methods of interest were evaluated for increasing the activity and copy number of mitochondria in the oocyte cell. METHODS This covered the researches from 1966 to September 2015. RESULTS The results provided ten methods that can be studied individually or simultaneously. CONCLUSION Though the use of these techniques generated great concern about heteroplasmy observation in humans, it seems that with study on these suggested methods there is real hope for effective treatments of old oocyte or oocytes containing mitochondrial problems in the near future.
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Affiliation(s)
- Sara Darbandi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | - Mahsa Darbandi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | | | - Mohammad Reza Sadeghi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | - Safaa Al-Hasani
- Reproductive Medicine Unit, University of Schleswig-Holstein, Luebeck, Germany.
| | - Ashok Agarwal
- Center for Reproductive Medicine, Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.
| | - Abolfazl Shirazi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | - Mahnaz Heidari
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran. M.@avicenna.ar.ir
| | - Mohammad Mehdi Akhondi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
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18
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Ca2+ signalling in the endoplasmic reticulum/secretory granule microdomain. Cell Calcium 2015; 58:397-404. [DOI: 10.1016/j.ceca.2015.01.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 01/16/2015] [Indexed: 01/20/2023]
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19
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Gerasimenko JV, Charlesworth RM, Sherwood MW, Ferdek PE, Mikoshiba K, Parrington J, Petersen OH, Gerasimenko OV. Both RyRs and TPCs are required for NAADP-induced intracellular Ca²⁺ release. Cell Calcium 2015; 58:237-45. [PMID: 26100948 PMCID: PMC4539342 DOI: 10.1016/j.ceca.2015.05.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/15/2015] [Accepted: 05/17/2015] [Indexed: 11/29/2022]
Abstract
Antibody against RyR1 reduced NAADP-evoked Ca2+ release by 81%. Combined inhibition of RyR1 and RyR3 (or RyR3-KO) reduced responses to NAADP by >90%. Knockout of TPC2 (or antibody against TPC2) reduced responses to NAADP by 64%. Combined inhibition of TPC2 and TPC1 reduced responses by 86%. In acidic stores inhibition of either pair of RyR1/3 or TPC1/2 abolished responses.
Intracellular Ca2+ release is mostly mediated by inositol trisphosphate, but intracellular cyclic-ADP-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP) are important messengers in many systems. Whereas cADPR generally activates type 2 ryanodine receptors (RyR2s), the NAADP-activated Ca2+ release mechanism is less clear. Using knockouts and antibodies against RyRs and Two-Pore Channels (TPCs), we have compared their relative importance for NAADP-induced Ca2+ release from two-photon permeabilized pancreatic acinar cells. In these cells, cholecystokinin-elicited Ca2+ release is mediated by NAADP. TPC2-KO reduced NAADP-induced Ca2+ release by 64%, but the combination of TPC2-KO and an antibody against TPC1, significantly reduced Ca2+ release by 86% (64% vs. 86%, p < 0.0002). In RyR3-KO, NAADP-evoked Ca2+ release reduced by ∼50% but, when combined with antibodies against RyR1, responses were 90% inhibited. Antibodies against RyR2 had practically no effect on NAADP-evoked Ca2+ release, but reduced release in response to cADPR by 55%. Antibodies to RyR1 inhibited NAADP-induced Ca2+ liberation by 81%, but only reduced cADPR responses by 30%. We conclude that full NAADP-mediated Ca2+ release requires both TPCs and RyRs. The sequence of relative importance for NAADP-elicited Ca2+ release from the all stores is RyR1 > TPC2 > RyR3 > TPC1 >> RyR2. However, when assessing NAADP-induced Ca2+ release solely from the acidic stores (granules/endosomes/lysosomes), antibodies against TPC2 and TPC1 virtually abolished the Ca2+ liberation as did antibodies against RyR1 and RyR3. Our results indicate that the primary, but very small, NAADP-elicited Ca2+ release via TPCs from endosomes/lysosomes triggers the detectable Ca2+-induced Ca2+ release via RyR1 and RyR3 occurring from the granules and the ER.
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Affiliation(s)
- Julia V Gerasimenko
- Medical Research Council Group, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Richard M Charlesworth
- Medical Research Council Group, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Mark W Sherwood
- Laboratory for Developmental Neurobiology, Riken Brain Science Institute, Wako City, Saitama, Japan
| | - Pawel E Ferdek
- Medical Research Council Group, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, Riken Brain Science Institute, Wako City, Saitama, Japan; Ca(2+) Oscillation Project, ICORP-SORST, JST, Wako City, Saitama, Japan
| | - John Parrington
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Ole H Petersen
- Medical Research Council Group, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Oleg V Gerasimenko
- Medical Research Council Group, Cardiff School of Biosciences, Cardiff University, Cardiff, Wales, UK.
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20
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Nezu A, Morita T, Tanimura A. In vitro and in vivo imaging of intracellular Ca2+ responses in salivary gland cells. J Oral Biosci 2015. [DOI: 10.1016/j.job.2015.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Abstract
The inducers of acute pancreatitis trigger a prolonged increase in the cytosolic Ca(2+) concentration ([Ca(2+)]c), which is responsible for the damage to and eventual death of pancreatic acinar cells. Vacuolization is an important indicator of pancreatic acinar cell damage. Furthermore, activation of trypsinogen occurs in the endocytic vacuoles; therefore the vacuoles can be considered as 'initiating' organelles in the development of the cell injury. In the present study, we investigated the relationship between the formation of endocytic vacuoles and Ca(2+) influx developed in response to the inducers of acute pancreatitis [bile acid taurolithocholic acid 3-sulfate (TLC-S) and supramaximal concentration of cholecystokinin-8 (CCK)]. We found that the inhibitor of STIM (stromal interaction molecule)/Orai channels, GSK-7975A, effectively suppressed both the Ca(2+) influx (stimulated by inducers of pancreatitis) and the formation of endocytic vacuoles. Cell death induced by TLC-S or CCK was also inhibited by GSK-7975A. We documented the formation of endocytic vacuoles in response to store-operated Ca(2+) entry (SOCE) induced by thapsigargin [TG; inhibitor of sarcoplasmic/endoplasmic reticulum (ER) Ca(2+) pumps] and observed strong inhibition of TG-induced vacuole formation by GSK-7975A. Finally, we found that structurally-unrelated inhibitors of calpain suppress formation of endocytic vacuoles, suggesting that this Ca2+-dependent protease is a mediator between Ca(2+) elevation and endocytic vacuole formation.
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22
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Vervloessem T, Yule DI, Bultynck G, Parys JB. The type 2 inositol 1,4,5-trisphosphate receptor, emerging functions for an intriguing Ca²⁺-release channel. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:1992-2005. [PMID: 25499268 DOI: 10.1016/j.bbamcr.2014.12.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 12/02/2014] [Accepted: 12/03/2014] [Indexed: 12/19/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) type 2 (IP3R2) is an intracellular Ca²⁺-release channel located on the endoplasmic reticulum (ER). IP3R2 is characterized by a high sensitivity to both IP3 and ATP and is biphasically regulated by Ca²⁺. Furthermore, IP3R2 is modulated by various protein kinases. In addition to its regulation by protein kinase A, IP3R2 forms a complex with adenylate cyclase 6 and is directly regulated by cAMP. Finally, in the ER, IP3R2 is less mobile than the other IP3R isoforms, while its functional properties appear dominant in heterotetramers. These properties make the IP3R2 a Ca²⁺ channel with exquisite properties for setting up intracellular Ca²⁺ signals with unique characteristics. IP3R2 plays a crucial role in the function of secretory cell types (e.g. pancreatic acinar cells, hepatocytes, salivary gland, eccrine sweat gland). In cardiac myocytes, the role of IP3R2 appears more complex, because, together with IP3R1, it is needed for normal cardiogenesis, while its aberrant activity is implicated in cardiac hypertrophy and arrhythmias. Most importantly, its high sensitivity to IP3 makes IP3R2 a target for anti-apoptotic proteins (e.g. Bcl-2) in B-cell cancers. Disrupting IP3R/Bcl-2 interaction therefore leads in those cells to increased Ca²⁺ release and apoptosis. Intriguingly, IP3R2 is not only implicated in apoptosis but also in the induction of senescence, another tumour-suppressive mechanism. These results were the first to unravel the physiological and pathophysiological role of IP3R2 and we anticipate that further progress will soon be made in understanding the function of IP3R2 in various tissues and organs.
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Affiliation(s)
- Tamara Vervloessem
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - David I Yule
- University of Rochester, Department of Pharmacology and Physiology, Rochester, NY, USA
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium
| | - Jan B Parys
- KU Leuven, Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, Leuven, Belgium.
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23
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Abstract
In a normal human life span, the heart beats about 2 to 3 billion times. Under diseased conditions, a heart may lose its normal rhythm and degenerate suddenly into much faster and irregular rhythms, called arrhythmias, which may lead to sudden death. The transition from a normal rhythm to an arrhythmia is a transition from regular electrical wave conduction to irregular or turbulent wave conduction in the heart, and thus this medical problem is also a problem of physics and mathematics. In the last century, clinical, experimental, and theoretical studies have shown that dynamical theories play fundamental roles in understanding the mechanisms of the genesis of the normal heart rhythm as well as lethal arrhythmias. In this article, we summarize in detail the nonlinear and stochastic dynamics occurring in the heart and their links to normal cardiac functions and arrhythmias, providing a holistic view through integrating dynamics from the molecular (microscopic) scale, to the organelle (mesoscopic) scale, to the cellular, tissue, and organ (macroscopic) scales. We discuss what existing problems and challenges are waiting to be solved and how multi-scale mathematical modeling and nonlinear dynamics may be helpful for solving these problems.
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Affiliation(s)
- Zhilin Qu
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
- Correspondence to: Zhilin Qu, PhD, Department of Medicine, Division of Cardiology, David Geffen School of Medicine at UCLA, A2-237 CHS, 650 Charles E. Young Drive South, Los Angeles, CA 90095, Tel: 310-794-6050, Fax: 310-206-9133,
| | - Gang Hu
- Department of Physics, Beijing Normal University, Beijing 100875, China
| | - Alan Garfinkel
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
- Department of Integrative Biology and Physiology, University of California, Los Angeles, California 90095, USA
| | - James N. Weiss
- Department of Medicine (Cardiology), David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA
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24
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Gerasimenko J, Peng S, Gerasimenko O. Role of acidic stores in secretory epithelia. Cell Calcium 2014; 55:346-54. [DOI: 10.1016/j.ceca.2014.04.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 04/05/2014] [Accepted: 04/08/2014] [Indexed: 12/14/2022]
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25
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Manhas N, Sneyd J, Pardasani KR. Modelling the transition from simple to complex Ca²⁺ oscillations in pancreatic acinar cells. J Biosci 2014; 39:463-84. [PMID: 24845510 DOI: 10.1007/s12038-014-9430-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A mathematical model is proposed which systematically investigates complex calcium oscillations in pancreatic acinar cells. This model is based on calcium-induced calcium release via inositol trisphosphate receptors (IPR) and ryanodine receptors (RyR) and includes calcium modulation of inositol (1,4,5) trisphosphate (IP3) levels through feedback regulation of degradation and production. In our model, the apical and the basal regions are separated by a region containing mitochondria, which is capable of restricting Ca2+ responses to the apical region. We were able to reproduce the observed oscillatory patterns, from baseline spikes to sinusoidal oscillations. The model predicts that calcium-dependent production and degradation of IP3 is a key mechanism for complex calcium oscillations in pancreatic acinar cells. A partial bifurcation analysis is performed which explores the dynamic behaviour of the model in both apical and basal regions.
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Affiliation(s)
- Neeraj Manhas
- Department of Mathematics, Maulana Azad National Institute of Technology, Bhopal 462 051, India,
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26
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Voronina S, Okeke E, Parker T, Tepikin A. How to win ATP and influence Ca(2+) signaling. Cell Calcium 2014; 55:131-8. [PMID: 24613709 DOI: 10.1016/j.ceca.2014.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 02/10/2014] [Accepted: 02/11/2014] [Indexed: 12/11/2022]
Abstract
This brief review discusses recent advances in studies of mitochondrial Ca(2+) signaling and considers how the relationships between mitochondria and Ca(2+) responses are shaped in secretory epithelial cells. Perhaps the more precise title of this review could have been "How to win ATP and influence Ca(2+) signaling in secretory epithelium with emphasis on exocrine secretory cells and specific focus on pancreatic acinar cells". But "brevity is a virtue" and the authors hope that many of the mechanisms discussed are general and applicable to other tissues and cell types. Among these mechanisms are mitochondrial regulation of Ca(2+) entry and the role of mitochondria in the formation of localized Ca(2+) responses. The roles of Ca(2+) signaling in the physiological adjustment of bioenergetics and in mitochondrial damage are also briefly discussed.
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Affiliation(s)
- Svetlana Voronina
- Department of Cellular and Molecular Physiology, The Physiological Laboratory, Institute of Translational Medicine, The University of Liverpool, Crown Street, Liverpool L69 3BX, UK
| | - Emmanuel Okeke
- Department of Cellular and Molecular Physiology, The Physiological Laboratory, Institute of Translational Medicine, The University of Liverpool, Crown Street, Liverpool L69 3BX, UK
| | - Tony Parker
- Department of Cellular and Molecular Physiology, The Physiological Laboratory, Institute of Translational Medicine, The University of Liverpool, Crown Street, Liverpool L69 3BX, UK
| | - Alexei Tepikin
- Department of Cellular and Molecular Physiology, The Physiological Laboratory, Institute of Translational Medicine, The University of Liverpool, Crown Street, Liverpool L69 3BX, UK.
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27
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Bartlett PJ, Gaspers LD, Pierobon N, Thomas AP. Calcium-dependent regulation of glucose homeostasis in the liver. Cell Calcium 2014; 55:306-16. [PMID: 24630174 DOI: 10.1016/j.ceca.2014.02.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 02/07/2014] [Accepted: 02/08/2014] [Indexed: 02/09/2023]
Abstract
A major role of the liver is to integrate multiple signals to maintain normal blood glucose levels. The balance between glucose storage and mobilization is primarily regulated by the counteracting effects of insulin and glucagon. However, numerous signals converge in the liver to ensure energy demand matches the physiological status of the organism. Many circulating hormones regulate glycogenolysis, gluconeogenesis and mitochondrial metabolism by calcium-dependent signaling mechanisms that manifest as cytosolic Ca(2+) oscillations. Stimulus-strength is encoded in the Ca(2+) oscillation frequency, and also by the range of intercellular Ca(2+) wave propagation in the intact liver. In this article, we describe how Ca(2+) oscillations and waves can regulate glucose output and oxidative metabolism in the intact liver; how multiple stimuli are decoded though Ca(2+) signaling at the organ level, and the implications of Ca(2+) signal dysregulation in diseases such as metabolic syndrome and non-alcoholic fatty liver disease.
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Affiliation(s)
- Paula J Bartlett
- Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA.
| | - Lawrence D Gaspers
- Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Nicola Pierobon
- Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
| | - Andrew P Thomas
- Department of Pharmacology and Physiology, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, USA
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28
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Petersen OH. Calcium signalling and secretory epithelia. Cell Calcium 2014; 55:282-9. [PMID: 24508392 DOI: 10.1016/j.ceca.2014.01.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 01/10/2014] [Indexed: 12/15/2022]
Abstract
Ca(2+) is now firmly established as the most important intracellular regulator of physiological and pathological events in a vast number of different cell types, including secretory epithelia. In these tissues, Ca(2+) signalling is crucially important for the control of both fluid secretion and electrolyte secretion as well as the regulation of macromolecule secretion. In this overview article, I shall attempt to give some general background to the concepts underlying our current thinking about Ca(2+) signalling in epithelia and its roles in regulating secretion. It is outside the scope of this review to provide a comprehensive account of Ca(2+) signalling and the many different processes in the many different secretory epithelia that are controlled by Ca(2+) signals. It is my aim to draw attention to some general features of Ca(2+) signalling processes in secretory epithelia, which are rather different from those in, for example, endocrine glands. The principal examples will be taken from studies of exocrine cells and, in particular, pancreatic acinar cells, as they are the pioneer cells with regard to investigations of Ca(2+) signalling due to primary intracellular Ca(2+) release. They also represent the cell type which has been characterized in most detail with regard to Ca(2+) transport events and mechanisms.
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Affiliation(s)
- O H Petersen
- MRC Secretory Control Research Group, Cardiff School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, Wales, UK.
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29
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Muramatsu S, Tamada T, Nara M, Murakami K, Kikuchi T, Kanehira M, Maruyama Y, Ebina M, Nukiwa T, Ichinose M. Flagellin/TLR5 signaling potentiates airway serous secretion from swine tracheal submucosal glands. Am J Physiol Lung Cell Mol Physiol 2013; 305:L819-30. [PMID: 24097563 DOI: 10.1152/ajplung.00053.2013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Airway serous secretion is essential for the maintenance of mucociliary transport in airway mucosa, which is responsible for the upregulation of mucosal immunity. Although there are many articles concerning the importance of Toll-like receptors (TLRs) in airway immune systems, the direct relationship between TLRs and airway serous secretion has not been well investigated. Here, we focused on whether TLR5 ligand flagellin, which is one of the components of Pseudomonas aeruginosa, is involved in the upregulation of airway serous secretion. Freshly isolated swine tracheal submucosal gland cells were prepared, and the standard patch-clamp technique was applied for measurements of the whole cell ionic responses of these cells. Flagellin showed potentiating effects on these oscillatory currents induced by physiologically relevant low doses of acetylcholine (ACh) in a dose-dependent manner. These potentiating effects were TLR5 dependent but TLR4 independent. Both nitric oxide (NO) synthase inhibitors and cGMP-dependent protein kinase (cGK) inhibitors abolished these flagellin-induced potentiating effects. Furthermore, TLR5 was abundantly expressed on tracheal submucosal glands. Flagellin/TLR5 signaling further accelerated the intracellular NO synthesis induced by ACh. These findings suggest that TLR5 takes part in the airway mucosal defense systems as a unique endogenous potentiator of airway serous secretions and that NO/cGMP/cGK signaling is involved in this rapid potentiation by TLR5 signaling.
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Affiliation(s)
- Soshi Muramatsu
- Dept. of Respiratory Medicine, Tohoku Univ. Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, JAPAN.
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30
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Nivala M, Ko CY, Nivala M, Weiss JN, Qu Z. The emergence of subcellular pacemaker sites for calcium waves and oscillations. J Physiol 2013; 591:5305-20. [PMID: 24042497 DOI: 10.1113/jphysiol.2013.259960] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Calcium (Ca(2+)) waves generating oscillatory Ca(2+) signals are widely observed in biological cells. Experimental studies have shown that under certain conditions, initiation of Ca(2+) waves is random in space and time, while under other conditions, waves occur repetitively from preferred locations (pacemaker sites) from which they entrain the whole cell. In this study, we use computer simulations to investigate the self-organization of Ca(2+) sparks into pacemaker sites generating Ca(2+) oscillations. In both ventricular myocyte experiments and computer simulations of a heterogeneous Ca(2+) release unit (CRU) network model, we show that Ca(2+) waves occur randomly in space and time when the Ca(2+) level is low, but as the Ca(2+) level increases, waves occur repetitively from the same sites. Our analysis indicates that this transition to entrainment can be attributed to the fact that random Ca(2+) sparks self-organize into Ca(2+) oscillations differently at low and high Ca(2+) levels. At low Ca(2+), the whole cell Ca(2+) oscillation frequency of the coupled CRU system is much slower than that of an isolated single CRU. Compared to a single CRU, the distribution of interspike intervals (ISIs) of the coupled CRU network exhibits a greater variation, and its ISI distribution is asymmetric with respect to the peak, exhibiting a fat tail. At high Ca(2+), however, the coupled CRU network has a faster frequency and lesser ISI variation compared to an individual CRU. The ISI distribution of the coupled network no longer exhibits a fat tail and is well-approximated by a Gaussian distribution. This same Ca(2+) oscillation behaviour can also be achieved by varying the number of ryanodine receptors per CRU or the distance between CRUs. Using these results, we develop a theory for the entrainment of random oscillators which provides a unified explanation for the experimental observations underlying the emergence of pacemaker sites and Ca(2+) oscillations.
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Affiliation(s)
- Michael Nivala
- Z. Qu: Department of Medicine, David Geffen School of Medicine at UCLA, A2-237 CHS, 650 Charles E. Young Drive South, Los Angeles, CA 90095.
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Abstract
Acute pancreatitis is a human disease in which the pancreatic pro-enzymes, packaged into the zymogen granules of acinar cells, become activated and cause autodigestion. The main causes of pancreatitis are alcohol abuse and biliary disease. A considerable body of evidence indicates that the primary event initiating the disease process is the excessive release of Ca(2+) from intracellular stores, followed by excessive entry of Ca(2+) from the interstitial fluid. However, Ca(2+) release and subsequent entry are also precisely the processes that control the physiological secretion of digestive enzymes in response to stimulation via the vagal nerve or the hormone cholecystokinin. The spatial and temporal Ca(2+) signal patterns in physiology and pathology, as well as the contributions from different organelles in the different situations, are therefore critical issues. There has recently been significant progress in our understanding of both physiological stimulus-secretion coupling and the pathophysiology of acute pancreatitis. Very recently, a promising potential therapeutic development has occurred with the demonstration that the blockade of Ca(2+) release-activated Ca(2+) currents in pancreatic acinar cells offers remarkable protection against Ca(2+) overload, intracellular protease activation and necrosis evoked by a combination of alcohol and fatty acids, which is a major trigger of acute pancreatitis.
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Affiliation(s)
- Julia V Gerasimenko
- MRC Group, School of Biosciences, Cardiff University, The Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK.
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Nakamura K, Hamada K, Terauchi A, Matsui M, Nakamura T, Okada T, Mikoshiba K. Distinct roles of M1 and M3 muscarinic acetylcholine receptors controlling oscillatory and non-oscillatory [Ca2+]i increase. Cell Calcium 2013; 54:111-9. [PMID: 23747049 DOI: 10.1016/j.ceca.2013.05.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 05/07/2013] [Accepted: 05/10/2013] [Indexed: 10/26/2022]
Abstract
We examined ACh-induced [Ca2+]i dynamics in pancreatic acinar cells prepared from mAChR subtype-specific knockout (KO) mice. ACh did not induce any [Ca2+]i increase in the cells isolated from M1/M3 double KO mice. In the cells from M3KO mice, ACh (0.3-3 μM) caused a monotonic [Ca2+]i increase. However, we found characteristic oscillatory [Ca2+]i increases in cells from M1KO mice in lower concentrations of ACh (0.03-0.3 μM). We investigated the receptor specific pattern of [Ca2+]i increase in COS-7 cells transfected with M1 or M3 receptors. ACh induced the oscillatory [Ca2+]i increase in M3 expressing cells, but not in cells expressing M1, which exhibited monotonic [Ca2+]i increases. IP3 production detected in fluorescent indicator co-transfected cells was higher in M1 than in M3 expressing cells. From the examination of four types of M1/M3 chimera receptors we found that the carboxyl-terminal region of M3 was responsible for the generation of Ca2+ oscillations. The present results suggest that the oscillatory Ca2+ increase in response to M3 stimulation is dependent upon a moderate IP3 increase, which is suitable for causing Ca(2+)-dependent IP3-induced Ca2+ release. The C-terminal domain of M3 may contribute as a regulator of the efficiency of Gq and PLC cooperation.
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Affiliation(s)
- Kyoko Nakamura
- Department of Physiology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
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33
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Abstract
Although Orai channels and their regulator stromal interacting molecule 1 (STIM1) were originally identified and described as the key components of the store-operated highly calcium-selective CRAC channels, it is now clear that these proteins are equally essential components of the agonist-activated, store-independent calcium entry pathway mediated by the arachidonic acid-regulated calcium-selective (ARC) channel. Correspondingly, ARC channels display biophysical properties that closely resemble those of CRAC channels but, whereas the latter is formed exclusively by Orai1 subunits, the ARC channel is formed by a combination of Orai1 and Orai3 subunits. Moreover, while STIM1 in the membrane of the endoplasmic reticulum is the critical sensor of intracellular calcium store depletion that results in the activation of the CRAC channels, it is the pool of STIM1 resident in the plasma membrane that regulates the activity of the store-independent ARC channels. Here, we describe the unique features of the ARC channels and their activation and discuss recent evidence indicating how these two coexisting, and biophysically very similar, Orai channels act to play entirely distinct roles in the regulation of various important cellular activities.
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34
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Spatial and temporal characteristics of Ca2+ signaling in endothelial cells of intact rat tail artery. Artery Res 2013. [DOI: 10.1016/j.artres.2013.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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35
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Cellular Calcium. Mol Pharmacol 2012. [DOI: 10.1002/9781118451908.ch9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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36
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Kasai H, Takahashi N, Tokumaru H. Distinct Initial SNARE Configurations Underlying the Diversity of Exocytosis. Physiol Rev 2012; 92:1915-64. [DOI: 10.1152/physrev.00007.2012] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The dynamics of exocytosis are diverse and have been optimized for the functions of synapses and a wide variety of cell types. For example, the kinetics of exocytosis varies by more than five orders of magnitude between ultrafast exocytosis in synaptic vesicles and slow exocytosis in large dense-core vesicles. However, in all cases, exocytosis is mediated by the same fundamental mechanism, i.e., the assembly of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. It is often assumed that vesicles need to be docked at the plasma membrane and SNARE proteins must be preassembled before exocytosis is triggered. However, this model cannot account for the dynamics of exocytosis recently reported in synapses and other cells. For example, vesicles undergo exocytosis without prestimulus docking during tonic exocytosis of synaptic vesicles in the active zone. In addition, epithelial and hematopoietic cells utilize cAMP and kinases to trigger slow exocytosis of nondocked vesicles. In this review, we summarize the manner in which the diversity of exocytosis reflects the initial configurations of SNARE assembly, including trans-SNARE, binary-SNARE, unitary-SNARE, and cis-SNARE configurations. The initial SNARE configurations depend on the particular SNARE subtype (syntaxin, SNAP25, or VAMP), priming proteins (Munc18, Munc13, CAPS, complexin, or snapin), triggering proteins (synaptotagmins, Doc2, and various protein kinases), and the submembraneous cytomatrix, and they are the key to determining the kinetics of subsequent exocytosis. These distinct initial configurations will help us clarify the common SNARE assembly processes underlying exocytosis and membrane trafficking in eukaryotic cells.
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Affiliation(s)
- Haruo Kasai
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; and Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa, Japan
| | - Noriko Takahashi
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; and Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa, Japan
| | - Hiroshi Tokumaru
- Laboratory of Structural Physiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan; and Faculty of Pharmaceutical Sciences at Kagawa, Tokushima Bunri University, Kagawa, Japan
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37
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Cellular geography of IP3 receptors, STIM and Orai: a lesson from secretory epithelial cells. Biochem Soc Trans 2012; 40:108-11. [PMID: 22260674 DOI: 10.1042/bst20110639] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pancreatic acinar cells exhibit a remarkable polarization of Ca2+ release and Ca2+ influx mechanisms. In the present brief review, we discuss the localization of channels responsible for Ca2+ release [mainly IP3 (inositol 1,4,5-trisphosphate) receptors] and proteins responsible for SOCE (store-operated Ca2+ entry). We also place these Ca2+-transporting mechanisms on the map of cellular organelles in pancreatic acinar cells, and discuss the physiological implications of the cellular geography of Ca2+ signalling. Finally, we highlight some unresolved questions stemming from recent observations of co-localization and co-immunoprecipitation of IP3 receptors with Orai channels in the apical (secretory) region of pancreatic acinar cells.
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38
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Ogata S, Miki T, Seino S, Tamai S, Kasai H, Nemoto T. A novel function of Noc2 in agonist-induced intracellular Ca2+ increase during zymogen-granule exocytosis in pancreatic acinar cells. PLoS One 2012; 7:e37048. [PMID: 22615885 PMCID: PMC3355174 DOI: 10.1371/journal.pone.0037048] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2011] [Accepted: 04/12/2012] [Indexed: 11/29/2022] Open
Abstract
Noc2, a putative Rab effector, contributes to secretory-granule exocytosis in neuroendocrine and exocrine cells. Here, using two-photon excitation live-cell imaging, we investigated its role in Ca2+-dependent zymogen granule (ZG) exocytosis in pancreatic acinar cells from wild-type (WT) and Noc2-knockout (KO) mice. Imaging of a KO acinar cell revealed an expanded granular area, indicating ZG accumulation. In our spatiotemporal analysis of the ZG exocytosis induced by agonist (cholecystokinin or acetylcholine) stimulation, the location and rate of progress of ZG exocytosis did not differ significantly between the two strains. ZG exocytosis from KO acinar cells was seldom observed at physiological concentrations of agonists, but was normal (vs. WT) at high concentrations. Flash photolysis of a caged calcium compound confirmed the integrity of the fusion step of ZG exocytosis in KO acinar cells. The decreased ZG exocytosis present at physiological concentrations of agonists raised the possibility of impaired elicitation of calcium spikes. When calcium spikes were evoked in KO acinar cells by a high agonist concentration: (a) they always started at the apical portion and traveled to the basal portion, and (b) calcium oscillations over the 10 µM level were observed, as in WT acinar cells. At physiological concentrations of agonists, however, sufficient calcium spikes were not observed, suggesting an impaired [Ca2+]i-increase mechanism in KO acinar cells. We propose that in pancreatic acinar cells, Noc2 is not indispensable for the membrane fusion of ZG per se, but instead performs a novel function favoring agonist-induced physiological [Ca2+]i increases.
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Affiliation(s)
- Sho Ogata
- Department of Cell Physiology, National Institute for Physiological Sciences, and Graduate University of Advanced Studies, SOKENDAI, Okazaki, Aichi, Japan.
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39
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Wagner LE, Yule DI. Differential regulation of the InsP₃ receptor type-1 and -2 single channel properties by InsP₃, Ca²⁺ and ATP. J Physiol 2012; 590:3245-59. [PMID: 22547632 DOI: 10.1113/jphysiol.2012.228320] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
An elevation of intracellular Ca2+ levels as a result of InsP3 receptor (InsP3R) activity represents a ubiquitous signalling pathway controlling a wide variety of cellular events. InsP3R activity is tightly controlled by the levels of the primary ligands, InsP3, Ca2+ and ATP. Importantly, InsP3Rs are regulated by Ca2+ i in a biphasic manner. Ca2+ release through all InsP3R family members is also modulated dramatically by ATP, albeit with sub-type-specific properties. To ascertain if a common mechanism can account for ATP and Ca2+ regulation of these InsP3R family members, we examined the effects of [ATP] on the Ca2+ dependency of rat InsP3R-1 (rInsP3R-1) and mouse InsP3R-2 (mInsP3R-2) activity expressed in DT40-3KO cells. We used the on-nucleus patch clamp recording technique with various [ATP], [InsP3] and [Ca2+] in the patch pipette and measured single InsP3R channel activity in stably transfected DT40 cells. Under identical conditions, at saturating [InsP3] and [ATP], the activity of rInsP3R-1 and mInsP3R-2 was essentially identical in terms of single channel conductance, maximal achievable open probability (Po) and the [Ca2+] required for activation and inhibition of activity. However, in contrast to rInsP3R-1 at saturating [InsP3], the activity of mInsP3R-2 was unaffected by [ATP]. At lower [InsP3], ATP had dramatic effects on mInsP3R-2 Po, but unlike the rInsP3R-1, this did not occur by altering the relative Ca2+ dependency, but by simply increasing the maximally achievable Po at a particular [InsP3] and [Ca2+]. [InsP3] did not alter the biphasic regulation of activity by Ca2+ in either rInsP3R-1 or mInsP3R-2. Analysis of the single channel kinetics indicated that Ca2+ and ATP modulate the Po predominately by facilitating extended bursting activity of the channel but the underlying biophysical mechanism appears to be distinct for each receptor. Subtype-specific regulation of InsP3R channel activity probably contributes to the fidelity of Ca2+ signalling in cells expressing these receptor subtypes.
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Affiliation(s)
- Larry E Wagner
- Department of Pharmacology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, USA
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40
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Petersen OH. Specific mitochondrial functions in separate sub-cellular domains of pancreatic acinar cells. Pflugers Arch 2012; 464:77-87. [PMID: 22491894 DOI: 10.1007/s00424-012-1099-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 03/14/2012] [Indexed: 01/06/2023]
Abstract
The pancreatic acinar cell synthesizes many digestive proenzymes, which are packaged into secretory (zymogen) granules and secreted by exocytosis upon the action of the neurotransmitter acetylcholine, released from vagal nerve endings, or the hormone cholecystokinin. These secretagogues mobilize Ca(2+) from internal stores and thereby create the cytosolic Ca(2+) signals that control exocytosis. Exocytosis requires Ca(2+), Mg(2+) and ATP. Mg(2+) is present in millimolars concentration throughout the cytosol, but high cytosolic Ca(2+) concentrations need to be created in the local domains near the apical plasma membrane. A special group of mitochondria surrounding the apical granular area play a crucial role in confining cytosolic Ca(2+) elevations to this part of the cell by acting as a Ca(2+) buffer barrier. The Ca(2+) uptake into these mitochondria during apical Ca(2+) spiking stimulates mitochondrial ATP synthesis. ATP is also required for Ca(2+) extrusion via the plasma membrane Ca(2+) pumps, mainly located in the apical area, as well as for Ca(2+) reuptake into the endoplasmic reticulum. Because Ca(2+) extrusion occurs during Ca(2+) spiking, there is a need for compensatory Ca(2+) entry via store-operated Ca(2+) channels. Sub-plasmalemmal (peripheral) mitochondria play an important role in supporting both store-operated Ca(2+) entry at the base as well as the subsequent Ca(2+) pumping into the endoplasmic reticulum. A third group of mitochondria surround the nucleus. They protect the nucleus against unwarranted Ca(2+) signals generated elsewhere and are capable of confining Ca(2+) signals primarily generated inside the nucleus to this part of the cell.
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Affiliation(s)
- Ole H Petersen
- MRC Group, School of Biosciences, Cardiff University, Biomedical Sciences Building, Museum Avenue, Cardiff, CF10 3AX, Wales, UK.
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41
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Lee MG, Ohana E, Park HW, Yang D, Muallem S. Molecular mechanism of pancreatic and salivary gland fluid and HCO3 secretion. Physiol Rev 2012; 92:39-74. [PMID: 22298651 DOI: 10.1152/physrev.00011.2011] [Citation(s) in RCA: 273] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Fluid and HCO(3)(-) secretion is a vital function of all epithelia and is required for the survival of the tissue. Aberrant fluid and HCO(3)(-) secretion is associated with many epithelial diseases, such as cystic fibrosis, pancreatitis, Sjögren's syndrome, and other epithelial inflammatory and autoimmune diseases. Significant progress has been made over the last 20 years in our understanding of epithelial fluid and HCO(3)(-) secretion, in particular by secretory glands. Fluid and HCO(3)(-) secretion by secretory glands is a two-step process. Acinar cells secrete isotonic fluid in which the major salt is NaCl. Subsequently, the duct modifies the volume and electrolyte composition of the fluid to absorb the Cl(-) and secrete HCO(3)(-). The relative volume secreted by acinar and duct cells and modification of electrolyte composition of the secreted fluids varies among secretory glands to meet their physiological functions. In the pancreas, acinar cells secrete a small amount of NaCl-rich fluid, while the duct absorbs the Cl(-) and secretes HCO(3)(-) and the bulk of the fluid in the pancreatic juice. Fluid secretion appears to be driven by active HCO(3)(-) secretion. In the salivary glands, acinar cells secrete the bulk of the fluid in the saliva that is driven by active Cl(-) secretion and contains high concentrations of Na(+) and Cl(-). The salivary glands duct absorbs both the Na(+) and Cl(-) and secretes K(+) and HCO(3)(-). In this review, we focus on the molecular mechanism of fluid and HCO(3)(-) secretion by the pancreas and salivary glands, to highlight the similarities of the fundamental mechanisms of acinar and duct cell functions, and to point out the differences to meet gland-specific secretions.
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Affiliation(s)
- Min Goo Lee
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Korea
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42
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Bhattacharya S, Verrill DS, Carbone KM, Brown S, Yule DI, Giovannucci DR. Distinct contributions by ionotropic purinoceptor subtypes to ATP-evoked calcium signals in mouse parotid acinar cells. J Physiol 2012; 590:2721-37. [PMID: 22451435 DOI: 10.1113/jphysiol.2012.228148] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
There is emerging consensus that P2X₄ and P2X₇ ionotropic purinoceptors (P2X₄R and P2X₇R) are critical players in regulating [Ca²⁺]i dynamics and fluid secretion in the salivary gland. In contrast, details regarding their compartmentalization and selective activation, contributions to the spatiotemporal properties of intracellular signals and roles in regulating protein exocytosis and ion channel activity have remained largely undefined. To address these concerns, we profiled mouse parotid acinar cells using live-cell imaging to follow the spatial and temporal features of ATP-evoked Ca²⁺ dynamics and exocytotic activity. Selective activation of P2X7Rs revealed an apical-to-basal [Ca²⁺]i signal that initiated at the sub-luminal border and propagated with a wave speed estimated at 17.3 ± 4.3 μm s⁻¹ (n =6). The evoked Ca²⁺ spike consisted of Ca²⁺ influx and Ca²⁺-induced Ca²⁺ release from intracellular Ca²⁺ channels. In contrast, selective activation of P2X₄Rs induced a Ca²⁺ signal that initiated basally and propagated toward the lumen with a wave speed of 4.3 ± 0.2 μm s⁻¹ (n =8) that was largely independent of intracellular Ca²⁺ channel blockade. Consistent with these observations, P2X₇R expression was enriched in the sub-luminal regions of acinar cells while P2X₄R appeared localized to basal areas. In addition, we showed that P2X₄R and P2X₇R activation evokes exocytosis in parotid acinar cells. Our studies also demonstrate that the P2X₄R-mediated [Ca²⁺]i rise and subsequent protein exocytosis was enhanced by ivermectin (IVR). Thus, in addition to furthering our understanding of salivary gland physiology, this study identifies P2X₄R as a potential target for treatment of salivary hypofunction diseases.
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Affiliation(s)
- Sumit Bhattacharya
- Department of Neurosciences, University of Toledo College of Medicine, Toledo, OH, USA
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43
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Park S, Lee SI, Shin DM. Role of regulators of g-protein signaling 4 in ca signaling in mouse pancreatic acinar cells. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2011; 15:383-8. [PMID: 22359476 PMCID: PMC3282226 DOI: 10.4196/kjpp.2011.15.6.383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Revised: 11/08/2011] [Accepted: 11/08/2011] [Indexed: 01/24/2023]
Abstract
Regulators of G-protein signaling (RGS) proteins are regulators of Ca2+ signaling that accelerate the GTPase activity of the G-protein α-subunit. RGS1, RGS2, RGS4, and RGS16 are expressed in the pancreas, and RGS2 regulates G-protein coupled receptor (GPCR)-induced Ca2+ oscillations. However, the role of RGS4 in Ca2+ signaling in pancreatic acinar cells is unknown. In this study, we investigated the mechanism of GPCR-induced Ca2+ signaling in pancreatic acinar cells derived from RGS4-/- mice. RGS4-/- acinar cells showed an enhanced stimulus intensity response to a muscarinic receptor agonist in pancreatic acinar cells. Moreover, deletion of RGS4 increased the frequency of Ca2+ oscillations. RGS4-/- cells also showed increased expression of sarco/endoplasmic reticulum Ca2+ ATPase type 2. However, there were no significant alterations, such as Ca2+ signaling in treated high dose of agonist and its related amylase secretion activity, in acinar cells from RGS4-/- mice. These results indicate that RGS4 protein regulates Ca2+ signaling in mouse pancreatic acinar cells.
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Affiliation(s)
- Soonhong Park
- Department of Oral Biology, Yonsei University College of Dentistry, Seoul 120-752, Korea
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44
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Petersen OH, Gerasimenko OV, Tepikin AV, Gerasimenko JV. Aberrant Ca(2+) signalling through acidic calcium stores in pancreatic acinar cells. Cell Calcium 2011; 50:193-9. [PMID: 21435718 DOI: 10.1016/j.ceca.2011.02.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 02/25/2011] [Accepted: 02/27/2011] [Indexed: 12/13/2022]
Abstract
Pancreatic acinar cells possess a very large Ca(2+) store in the endoplasmic reticulum, but also have extensive acidic Ca(2+) stores. Whereas the endoplasmic reticulum is principally located in the baso-lateral part of the cells, although with extensions into the granular area, the acidic stores are exclusively present in the apical part. The two types of stores can be differentiated pharmacologically because the endoplasmic reticulum accumulates Ca(2+) via SERCA pumps, whereas the acidic pools require functional vacuolar H(+) pumps in order to maintain a high intra-organellar Ca(2+) concentration. The human disease acute pancreatitis is initiated by trypsinogen activation in the apical pole and this is mostly due to either complications arising from gall bladder stones or excessive alcohol consumption. Attention has therefore been focussed on assessing the acute effects of bile acids as well as alcohol metabolites. The evidence accumulated so far indicates that bile acids and fatty acid ethyl esters - the non-oxidative products of alcohol and fatty acids - exert their pathological effects primarily by excessive Ca(2+) release from the acidic stores. This occurs by opening of the very same release channels that are also responsible for normal stimulus-secretion coupling, namely inositol trisphosphate and ryanodine receptors. The inositol trisphosphate receptors are of particular importance and the results of gene deletion experiments indicate that the fatty acid ethyl esters mainly utilize sub-types 2 and 3.
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Affiliation(s)
- O H Petersen
- MRC Secretory Control Group, Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff CF10 3AX, Wales, UK.
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Abstract
Calcium waves are propagated in five main speed ranges which cover a billion-fold range of speeds. We define the fast speed range as 3-30μm/s after correction to a standard temperature of 20°C. Only waves which are not fertilization waves are considered here. 181 such cases are listed here. These are through organisms in all major taxa from cyanobacteria through mammals including human beings except for those through other bacteria, higher plants and fungi. Nearly two-thirds of these speeds lie between 12 and 24μm/s. We argue that their common mechanism in eukaryotes is a reaction-diffusion one involving calcium-induced calcium release, in which calcium waves are propagated along the endoplasmic reticulum. We propose that the gliding movements of some cyanobacteria are driven by fast calcium waves which are propagated along their plasma membranes. Fast calcium waves may drive materials to one end of developing embryos by cellular peristalsis, help coordinate complex cell movements during development and underlie brain injury waves. Moreover, we continue to argue that such waves greatly increase the likelihood that chronic injuries will initiate tumors and cancers before genetic damage occurs. Finally we propose numerous further studies.
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Dolganiuc A. Role of lipid rafts in liver health and disease. World J Gastroenterol 2011; 17:2520-35. [PMID: 21633657 PMCID: PMC3103810 DOI: 10.3748/wjg.v17.i20.2520] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 02/24/2011] [Accepted: 03/03/2011] [Indexed: 02/06/2023] Open
Abstract
Liver diseases are an increasingly common cause of morbidity and mortality; new approaches for investigation of mechanisms of liver diseases and identification of therapeutic targets are emergent. Lipid rafts (LRs) are specialized domains of cellular membranes that are enriched in saturated lipids; they are small, mobile, and are key components of cellular architecture, protein partition to cellular membranes, and signaling events. LRs have been identified in the membranes of all liver cells, parenchymal and non-parenchymal; more importantly, LRs are active participants in multiple physiological and pathological conditions in individual types of liver cells. This article aims to review experimental-based evidence with regard to LRs in the liver, from the perspective of the liver as a whole organ composed of a multitude of cell types. We have gathered up-to-date information related to the role of LRs in individual types of liver cells, in liver health and diseases, and identified the possibilities of LR-dependent therapeutic targets in liver diseases.
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Orabi AI, Shah AU, Muili K, Luo Y, Mahmood SM, Ahmad A, Reed A, Husain SZ. Ethanol enhances carbachol-induced protease activation and accelerates Ca2+ waves in isolated rat pancreatic acini. J Biol Chem 2011; 286:14090-7. [PMID: 21372126 DOI: 10.1074/jbc.m110.196832] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Alcohol abuse is a leading cause of pancreatitis, accounting for 30% of acute cases and 70-90% of chronic cases, yet the mechanisms leading to alcohol-associated pancreatic injury are unclear. An early and critical feature of pancreatitis is the aberrant signaling of Ca(2+) within the pancreatic acinar cell. An important conductor of this Ca(2+) is the basolaterally localized, intracellular Ca(2+) channel ryanodine receptor (RYR). In this study, we examined the effect of ethanol on mediating both pathologic intra-acinar protease activation, a precursor to pancreatitis, as well as RYR Ca(2+) signals. We hypothesized that ethanol sensitizes the acinar cell to protease activation by modulating RYR Ca(2+). Acinar cells were freshly isolated from rat, pretreated with ethanol, and stimulated with the muscarinic agonist carbachol (1 μM). Ethanol caused a doubling in the carbachol-induced activation of the proteases trypsin and chymotrypsin (p < 0.02). The RYR inhibitor dantrolene abrogated the enhancement of trypsin and chymotrypsin activity by ethanol (p < 0.005 for both proteases). Further, ethanol accelerated the speed of the apical to basolateral Ca(2+) wave from 9 to 18 μm/s (p < 0.0005; n = 18-22 cells/group); an increase in Ca(2+) wave speed was also observed with a change from physiologic concentrations of carbachol (1 μM) to a supraphysiologic concentration (1 mM) that leads to protease activation. Dantrolene abrogated the ethanol-induced acceleration of wave speed (p < 0.05; n = 10-16 cells/group). Our results suggest that the enhancement of pathologic protease activation by ethanol is dependent on the RYR and that a novel mechanism for this enhancement may involve RYR-mediated acceleration of Ca(2+) waves.
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Affiliation(s)
- Abrahim I Orabi
- Yale University School of Medicine, New Haven, Connecticut 06520, USA
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Tanimura A. The Development of FRET-Based IP3 Biosensors and Their Use for Monitoring IP3 Dynamics during Ca2+ Oscillations and Ca2+ Waves in Non-Excitable Cells. J Oral Biosci 2011. [DOI: 10.1016/s1349-0079(11)80013-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Morita M, Kudo Y. Growth factors upregulate astrocyte [Ca2+]i oscillation by increasing SERCA2b expression. Glia 2010; 58:1988-95. [DOI: 10.1002/glia.21067] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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