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Englisch CN, Kirstein E, Diebolt CM, Wagner M, Tschernig T. Distribution of TRPC3 and TRPC6 in the human exocrine and endocrine pancreas. Pathol Res Pract 2024; 260:155403. [PMID: 38870712 DOI: 10.1016/j.prp.2024.155403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/03/2024] [Accepted: 06/09/2024] [Indexed: 06/15/2024]
Abstract
BACKGROUND Expression and function of TRPC3 and TRPC6 in the pancreas is a controversial topic. Investigation in human tissue is seldom. We aimed to provide here a detailed description of the distribution of TRPC3 and TRPC6 in the human exocrine and endocrine pancreas. METHODS We collected healthy samples from cadavers (n = 4) and visceral surgery (n = 4) to investigate the respective expression profiles using immunohistochemical tracing with knockout-validated antibodies. RESULTS TRPC3- and TRPC6-proteins were detected in different pancreatic structures including acinar cells, as well as epithelial ductal cells from intercalate, intralobular, and interlobular ducts. Respective connective tissue layers appeared unstained. Endocrine islets of Langerhans were clearly and homogenously immunolabeled by the anti-TRPC3 and anti-TRPC6 antibodies. Insular α, β, γ, and δ cells were conclusively stained, although no secure differentiation of cell types was performed. CONCLUSIONS Due to aforementioned antibody specificity verification, protein expression in the immunolabeled localizations can be accepted. Our study in human tissue supports previous investigations especially with respect to acinar and insular α and β cells, while other localizations are here reported for the first time to express TRPC3 and TRPC6, ultimately warranting further research.
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Affiliation(s)
- Colya N Englisch
- Institute for Anatomy and Cell Biology, Saarland University, 66421 Homburg, Saarland, Germany.
| | - Emilie Kirstein
- Institute for Anatomy and Cell Biology, Saarland University, 66421 Homburg, Saarland, Germany
| | - Coline M Diebolt
- Institute for Anatomy and Cell Biology, Saarland University, 66421 Homburg, Saarland, Germany
| | - Mathias Wagner
- Department of General and Special Pathology, Saarland University Medical Center, 66421 Homburg, Saarland, Germany
| | - Thomas Tschernig
- Institute for Anatomy and Cell Biology, Saarland University, 66421 Homburg, Saarland, Germany
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2
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Kirstein E, Schaudien D, Wagner M, Diebolt CM, Bozzato A, Tschernig T, Englisch CN. TRPC3 Is Downregulated in Primary Hyperparathyroidism. Int J Mol Sci 2024; 25:4392. [PMID: 38673977 PMCID: PMC11049814 DOI: 10.3390/ijms25084392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 04/08/2024] [Accepted: 04/12/2024] [Indexed: 04/28/2024] Open
Abstract
Transient receptor potential canonical sub-family channel 3 (TRPC3) is considered to play a critical role in calcium homeostasis. However, there are no established findings in this respect with regard to TRPC6. Although the parathyroid gland is a crucial organ in calcium household regulation, little is known about the protein distribution of TRPC channels-especially TRPC3 and TRPC6-in this organ. Our aim was therefore to investigate the protein expression profile of TRPC3 and TRPC6 in healthy and diseased human parathyroid glands. Surgery samples from patients with healthy parathyroid glands and from patients suffering from primary hyperparathyroidism (pHPT) were investigated by immunohistochemistry using knockout-validated antibodies against TRPC3 and TRPC6. A software-based analysis similar to an H-score was performed. For the first time, to our knowledge, TRPC3 and TRPC6 protein expression is described here in the parathyroid glands. It is found in both chief and oxyphilic cells. Furthermore, the TRPC3 staining score in diseased tissue (pHPT) was statistically significantly lower than that in healthy tissue. In conclusion, TRPC3 and TRPC6 proteins are expressed in the human parathyroid gland. Furthermore, there is strong evidence indicating that TRPC3 plays a role in pHPT and subsequently in parathyroid hormone secretion regulation. These findings ultimately require further research in order to not only confirm our results but also to further investigate the relevance of these channels and, in particular, that of TRPC3 in the aforementioned physiological functions and pathophysiological conditions.
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Affiliation(s)
- Emilie Kirstein
- Institute for Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany (C.N.E.)
| | - Dirk Schaudien
- Fraunhofer Institute for Toxicology and Experimental Medicine, 30625 Hanover, Germany
| | - Mathias Wagner
- Department of Pathology, Saarland University, 66421 Homburg, Germany
| | - Coline M. Diebolt
- Institute for Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany (C.N.E.)
| | - Alessandro Bozzato
- Department of Otorhinolaryngology, Head and Neck Surgery, Saarland University, 66421 Homburg, Germany;
| | - Thomas Tschernig
- Institute for Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany (C.N.E.)
| | - Colya N. Englisch
- Institute for Anatomy and Cell Biology, Saarland University, 66421 Homburg, Germany (C.N.E.)
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3
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Khan SU, Khan SU, Suleman M, Khan MU, Alsuhaibani AM, Refat MS, Hussain T, Ud Din MA, Saeed S. The Multifunctional TRPC6 Protein: Significance in the Field of Cardiovascular Studies. Curr Probl Cardiol 2024; 49:102112. [PMID: 37774899 DOI: 10.1016/j.cpcardiol.2023.102112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/01/2023]
Abstract
Cardiovascular disease is the leading cause of death, medical complications, and healthcare costs. Although recent advances have been in treating cardiovascular disorders linked with a reduced ejection fraction, acutely decompensate cardiac failure remains a significant medical problem. The transient receptor potential cation channel (TRPC6) family responds to neurohormonal and mechanical stress, playing critical roles in cardiovascular diseases. Therefore, TRP C6 channels have great promise as therapeutic targets. Numerous studies have investigated the roles of TRP C6 channels in pain neurons, highlighting their significance in cardiovascular research. The TRPC6 protein exhibits a broad distribution in various organs and tissues, including the brain, nerves, heart, blood vessels, lungs, kidneys, gastrointestinal tract, and other bodily structures. Its activation can be triggered by alterations in osmotic pressure, mechanical stimulation, and diacylglycerol. Consequently, TRPC6 plays a significant role in the pathophysiological mechanisms underlying diverse diseases within living organisms. A recent study has indicated a strong correlation between the disorder known as TRPC6 and the development of cardiovascular diseases. Consequently, investigations into the association between TRPC6 and cardiovascular diseases have gained significant attention in the scientific community. This review explores the most recent developments in the recognition and characterization of TRPC6. Additionally, it considers the field's prospects while examining how TRPC6 might be altered and its clinical applications.
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Affiliation(s)
- Safir Ullah Khan
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, China.
| | - Shahid Ullah Khan
- Integrative Science Center of Germplasm Creation in Western China (CHONGQING) Science City and Southwest University, College of Agronomy and Biotechnology, Southwest University, Chongqing, China; Department of Biochemistry, Women Medical and Dental College, Khyber Medical University, Abbottabad, Pakistan.
| | - Muhammad Suleman
- Center for Biotechnology and Microbiology, University of Swat, Swat, Pakistan
| | - Munir Ullah Khan
- Department of Polymer Science and Engineering, MOE Key Laboratory of Macromolecular Synthesis and Functionalization, International Research Center for X Polymers, Zhejiang University, Hangzhou, China
| | - Amnah Mohammed Alsuhaibani
- Department of Physical Sport Science, College of Education, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Moamen S Refat
- Department of Chemistry, College of Science, Taif University, Taif, Saudi Arabia
| | - Talib Hussain
- Women Dental College, Khyber Medical University, Abbottabad, Pakistan
| | - Muhammad Azhar Ud Din
- Key Laboratory of Medical Science and Laboratory Medicine of Jiangsu Province, School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, P.R. China
| | - Sumbul Saeed
- School of Environment and Science, Griffith University, Nathan, QLD, Australia
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4
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Cheung HYF, Zou J, Tantiwong C, Fernandez DI, Huang J, Ahrends R, Roest M, Cavill R, Gibbins J, Heemskerk JWM. High-throughput assessment identifying major platelet Ca 2+ entry pathways via tyrosine kinase-linked and G protein-coupled receptors. Cell Calcium 2023; 112:102738. [PMID: 37060673 DOI: 10.1016/j.ceca.2023.102738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/04/2023] [Accepted: 04/06/2023] [Indexed: 04/17/2023]
Abstract
In platelets, elevated cytosolic Ca2+ is a crucial second messenger, involved in most functional responses, including shape change, secretion, aggregation and procoagulant activity. The platelet Ca2+ response consists of Ca2+ mobilization from endoplasmic reticulum stores, complemented with store-operated or receptor-operated Ca2+ entry pathways. Several channels can contribute to the Ca2+ entry, but their relative contribution is unclear upon stimulation of ITAM-linked receptors such as glycoprotein VI (GPVI) and G-protein coupled receptors such as the protease-activated receptors (PAR) for thrombin. We employed a 96-well plate high-throughput assay with Fura-2-loaded human platelets to perform parallel [Ca2+]i measurements in the presence of EGTA or CaCl2. Per agonist condition, this resulted in sets of EGTA, CaCl2 and Ca2+ entry ratio curves, defined by six parameters, reflecting different Ca2+ ion fluxes. We report that threshold stimulation of GPVI or PAR, with a variable contribution of secondary mediators, induces a maximal Ca2+ entry ratio of 3-7. Strikingly, in combination with Ca2+-ATPase inhibition by thapsigargin, the maximal Ca2+ entry ratio increased to 400 (GPVI) or 40 (PAR), pointing to a strong receptor-dependent enhancement of store-operated Ca2+ entry. By pharmacological blockage of specific Ca2+ channels in platelets, we found that, regardless of GPVI or PAR stimulation, the Ca2+ entry ratio was strongest affected by inhibition of ORAI1 (2-APB, Synta66) > Na+/Ca2+ exchange (NCE) > P2×1 (only initial). In contrast, inhibition of TRPC6, Piezo1/2 or STIM1 was without effect. Together, these data reveal ORAI1 and NCE as dominating Ca2+ carriers regulating GPVI- and PAR-induced Ca2+ entry in human platelets.
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Affiliation(s)
- Hilaire Yam Fung Cheung
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V, Dortmund, Germany; Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Jinmi Zou
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; Synapse Research Institute Maastricht, 6217 KD Maastricht, The Netherlands
| | - Chukiat Tantiwong
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; Institute for Cardiovascular and Metabolic Research (ICMR), School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Delia I Fernandez
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, 15706, Spain
| | - Jingnan Huang
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V, Dortmund, Germany; Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Universidade de Santiago de Compostela, Santiago de Compostela, 15706, Spain
| | - Robert Ahrends
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V, Dortmund, Germany; Dept. of Analytical Chemistry, University of Vienna, Vienna, Austria
| | - Mark Roest
- Synapse Research Institute Maastricht, 6217 KD Maastricht, The Netherlands
| | - Rachel Cavill
- Department of Advanced Computing Sciences, Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Jon Gibbins
- Institute for Cardiovascular and Metabolic Research (ICMR), School of Biological Sciences, University of Reading, Reading, United Kingdom
| | - Johan W M Heemskerk
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands; Synapse Research Institute Maastricht, 6217 KD Maastricht, The Netherlands.
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Harper MT. Platelet-Derived Extracellular Vesicles in Arterial Thrombosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1418:259-275. [PMID: 37603285 DOI: 10.1007/978-981-99-1443-2_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Abstract
Blood platelets are necessary for normal haemostasis but also form life-threatening arterial thrombi when atherosclerotic plaques rupture. Activated platelets release many extracellular vesicles during thrombosis. Phosphatidylserine-exposing microparticles promote coagulation. Small exosomes released during granule secretion deliver cargoes including microRNAs to cells throughout the cardiovascular system. Here, we discuss the mechanisms by which platelets release these extracellular vesicles, together with the possibility of inhibiting this release as an antithrombotic strategy.
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Affiliation(s)
- Matthew T Harper
- Department of Pharmacology, University of Cambridge, Cambridge, UK.
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6
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Yang L, Ottenheijm R, Worley P, Freichel M, Camacho Londoño JE. Reduction in SOCE and Associated Aggregation in Platelets from Mice with Platelet-Specific Deletion of Orai1. Cells 2022; 11:cells11203225. [PMID: 36291093 PMCID: PMC9600098 DOI: 10.3390/cells11203225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 09/20/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022] Open
Abstract
Calcium signalling in platelets through store operated Ca2+ entry (SOCE) or receptor-operated Ca2+ entry (ROCE) mechanisms is crucial for platelet activation and function. Orai1 proteins have been implicated in platelet’s SOCE. In this study we evaluated the contribution of Orai1 proteins to these processes using washed platelets from adult mice from both genders with platelet-specific deletion of the Orai1 gene (Orai1flox/flox; Pf4-Cre termed as Orai1Plt-KO) since mice with ubiquitous Orai1 deficiency show early lethality. Platelet aggregation as well as Ca2+ entry and release were measured in vitro following stimulation with collagen, collagen related peptide (CRP), thromboxane A2 analogue U46619, thrombin, ADP and the sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) inhibitor thapsigargin, respectively. SOCE and aggregation induced by Thapsigargin up to a concentration of 0.3 µM was abrogated in Orai1-deficient platelets. Receptor-operated Ca2+-entry and/or platelet aggregation induced by CRP, U46619 or thrombin were partially affected by Orai1 deletion depending on the gender. In contrast, ADP-, collagen- and CRP-induced aggregation was comparable in Orai1Plt-KO platelets and control cells over the entire concentration range. Our results reinforce the indispensability of Orai1 proteins for SOCE in murine platelets, contribute to understand its role in agonist-dependent signalling and emphasize the importance to analyse platelets from both genders.
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Affiliation(s)
- Linlin Yang
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Roger Ottenheijm
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Paul Worley
- The Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Marc Freichel
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
- Correspondence: (M.F.); (J.E.C.L.)
| | - Juan E. Camacho Londoño
- Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
- Correspondence: (M.F.); (J.E.C.L.)
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7
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Uzun G, Singh A, Abou-Khalel W, Pelzl L, Weich K, Nowak-Harnau S, Althaus K, Bugert P, Klüter H, Bakchoul T. Platelets and Sera from Donors of Convalescent Plasma after Mild COVID-19 Show No Procoagulant Phenotype. Hamostaseologie 2022; 42:S14-S23. [DOI: 10.1055/a-1797-0564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023] Open
Abstract
AbstractCoronavirus disease-2019 (COVID-19) is associated with increased thromboembolic complications. Long-term alteration in the coagulation system after acute COVID-19 infection is still a subject of research. Furthermore, the effect of sera from convalescent subjects on platelets is not known. In this study, we investigated platelet phenotype, coagulation, and fibrinolysis in COVID-19 convalescent plasma (CCP) donors and analyzed convalescent sera-induced effects on platelets. We investigated CCP donors who had a history of mild COVID-19 infection and donors who did not have COVID-19 were used as controls. We analyzed phosphatidylserine (PS) externalization, CD62p expression, and glycoprotein VI (GPVI) shedding both in platelet-rich plasma (PRP) and after incubation of washed healthy platelets with donors' sera using flow cytometry. Coagulation and fibrinolysis systems were assessed with thromboelastometry. Forty-seven CCP donors (22 males, 25 females; mean age (±SD): 41.4 ± 13.7 years) with a history of mild COVID-19 infection were included. Median duration after acute COVID-19 infection was 97 days (range, 34–401). We did not find an increased PS externalization, CD62p expression, or GPVI shedding in platelets from CCP donors. Sera from CCP donors did not induce PS externalization or GPVI shedding in healthy platelets. Sera-induced CD62p expression was slightly, albeit statistically significantly, lower in CCP donors than in plasma donors without a history of COVID-19. One patient showed increased maximum clot firmness and prolonged lysis time in thromboelastometry. Our findings suggest that procoagulant platelet phenotype is not present after mild COVID-19. Furthermore, CCP sera do not affect the activation status of platelets.
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Affiliation(s)
- Günalp Uzun
- Centre for Clinical Transfusion Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Anurag Singh
- Institute for Clinical and Experimental Transfusion Medicine, Medical Faculty of Tübingen, University Hospital of Tübingen, Tübingen, Germany
| | - Wissam Abou-Khalel
- Centre for Clinical Transfusion Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Lisann Pelzl
- Institute for Clinical and Experimental Transfusion Medicine, Medical Faculty of Tübingen, University Hospital of Tübingen, Tübingen, Germany
| | - Karoline Weich
- Centre for Clinical Transfusion Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Stefanie Nowak-Harnau
- Centre for Clinical Transfusion Medicine, University Hospital of Tübingen, Tübingen, Germany
| | - Karina Althaus
- Centre for Clinical Transfusion Medicine, University Hospital of Tübingen, Tübingen, Germany
- Institute for Clinical and Experimental Transfusion Medicine, Medical Faculty of Tübingen, University Hospital of Tübingen, Tübingen, Germany
| | - Peter Bugert
- Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, Heidelberg University, Hessen, Mannheim, Germany
| | - Harald Klüter
- Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, Heidelberg University, Hessen, Mannheim, Germany
| | - Tamam Bakchoul
- Centre for Clinical Transfusion Medicine, University Hospital of Tübingen, Tübingen, Germany
- Institute for Clinical and Experimental Transfusion Medicine, Medical Faculty of Tübingen, University Hospital of Tübingen, Tübingen, Germany
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8
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Kazandzhieva K, Mammadova-Bach E, Dietrich A, Gudermann T, Braun A. TRP channel function in platelets and megakaryocytes: basic mechanisms and pathophysiological impact. Pharmacol Ther 2022; 237:108164. [PMID: 35247518 DOI: 10.1016/j.pharmthera.2022.108164] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 01/29/2022] [Accepted: 02/28/2022] [Indexed: 12/30/2022]
Abstract
Transient receptor potential (TRP) proteins form a superfamily of cation channels that are expressed in a wide range of tissues and cell types. During the last years, great progress has been made in understanding the molecular complexity and the functions of TRP channels in diverse cellular processes, including cell proliferation, migration, adhesion and activation. The diversity of functions depends on multiple regulatory mechanisms by which TRP channels regulate Ca2+ entry mechanisms and intracellular Ca2+ dynamics, either through membrane depolarization involving cation influx or store- and receptor-operated mechanisms. Abnormal function or expression of TRP channels results in vascular pathologies, including hypertension, ischemic stroke and inflammatory disorders through effects on vascular cells, including the components of blood vessels and platelets. Moreover, some TRP family members also regulate megakaryopoiesis and platelet production, indicating a complex role of TRP channels in pathophysiological conditions. In this review, we describe potential roles of TRP channels in megakaryocytes and platelets, as well as their contribution to diseases such as thrombocytopenia, thrombosis and stroke. We also critically discuss the potential of TRP channels as possible targets for disease prevention and treatment.
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Affiliation(s)
- Kalina Kazandzhieva
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany
| | - Elmina Mammadova-Bach
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany; Division of Nephrology, Department of Medicine IV, Ludwig-Maximilians-University Hospital, Munich, Germany
| | - Alexander Dietrich
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany; German Center for Lung Research (DZL), Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany; German Center for Lung Research (DZL), Munich, Germany.
| | - Attila Braun
- Walther-Straub-Institute for Pharmacology and Toxicology, Ludwig-Maximilians-University, Munich, Germany.
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9
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Boekell KL, Brown BJ, Talbot BE, Schlondorff JS. Trpc6 gain-of-function disease mutation enhances phosphatidylserine exposure in murine platelets. PLoS One 2022; 17:e0270431. [PMID: 35749414 PMCID: PMC9231752 DOI: 10.1371/journal.pone.0270431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 06/09/2022] [Indexed: 01/28/2023] Open
Abstract
Platelets enhance coagulation by exposing phosphatidylserine (PS) on their cell surface in response to strong agonist activation. Transient receptor potential channels, including TRPC6, have been implicated in the calcium influx central to this process. Here, we characterize the effect of a Trpc6 gain-of-function (GOF) disease-associated, and a dominant negative (DN), mutation on murine platelet activation. Platelets from mice harboring Trpc6E896K/E896K (GOF) and Trpc6DN/DN mutations were subject to in vitro analysis. Trpc6E896K/E896K and Trpc6DN/DN mutant platelets show enhanced and absent calcium influx, respectively, upon addition of the TRPC3/6 agonist GSK1702934A (GSK). GSK was sufficient to induce integrin αIIbβ3 activation, P-selection and PS exposure, talin cleavage, and MLC2 phosphorylation in Trpc6E896K/E896K, but not in wild-type, platelets. Thrombin-induced calcium influx and PS exposure were enhanced, and clot retraction delayed, by GOF TRPC6, while no differences were noted between wild-type and Trpc6DN/DN platelets. In contrast, Erk activation upon GSK treatment was absent in Trpc6DN/DN, and enhanced in Trpc6E896K/E896K, platelets, compared to wild-type. The positive allosteric modulator, TRPC6-PAM-C20, and fluoxetine maintained their ability to enhance and inhibit, respectively, GSK-mediated calcium influx in Trpc6E896K/E896K platelets. The data demonstrate that gain-of-function mutant TRPC6 channel can enhance platelet activation, including PS exposure, while confirming that TRPC6 is not necessary for this process. Furthermore, the results suggest that Trpc6 GOF disease mutants do not simply increase wild-type TRPC6 responses, but can affect pathways not usually modulated by TRPC6 channel activity, displaying a true gain-of-function phenotype.
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Affiliation(s)
- Kimber L. Boekell
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brittney J. Brown
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brianna E. Talbot
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Johannes S. Schlondorff
- Department of Medicine, Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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10
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Jacobs T, Abdinghoff J, Tschernig T. Protein detection and localization of the non-selective cation channel TRPC6 in the human heart. Eur J Pharmacol 2022; 924:174972. [PMID: 35483666 DOI: 10.1016/j.ejphar.2022.174972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/28/2022] [Accepted: 04/19/2022] [Indexed: 11/03/2022]
Abstract
Due to longer lifespans in societies in industrialized countries, cardiovascular diseases are becoming increasingly important for medical research. It has already been shown that the cell membrane-bound, non-selective TRPC6 ion channel is important in the pathogenesis of heart diseases. Among other things, it is permeable to calcium ion, which plays a critical role in cardiac contraction and relaxation. The TRPC6 ion channel is a promising therapeutic target in the treatment of cardiovascular diseases. A deeper understanding of the physiological and pathophysiological role as well as the localization of TRPC6 in human cardiac tissue is the basis for new drug development. Although the TRPC6 channel has been detected in animal studies, at the mRNA level in humans, and sparse TRPC6 protein has been detected in humans, there are no systematic studies of TRPC6 protein detection in the human heart. For the first time, TRPC6 ion channel protein was detected histologically in human heart tissue from body donors in different structures, localizations, and histological layers - particularly in cardiomyocytes and intramuscular arterioles - by immunohistochemistry, just as TRPC6 expression has already been shown in animal models of the heart by other research groups. In the sense of the translational concept, this indicates a possible transferability of research results from animal models to humans.
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Affiliation(s)
- Tobias Jacobs
- Institute of Anatomy and Cell Biology, Saarland University, Medical Campus, Homburg, Saar, Germany
| | - Jan Abdinghoff
- Institute of Anatomy and Cell Biology, Saarland University, Medical Campus, Homburg, Saar, Germany
| | - Thomas Tschernig
- Institute of Anatomy and Cell Biology, Saarland University, Medical Campus, Homburg, Saar, Germany.
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11
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Xia J, Dou Y, Mei Y, Munoz FM, Gao R, Gao X, Li D, Osei-Owusu P, Schiffenhaus J, Bekker A, Tao YX, Hu H. Orai1 is a crucial downstream partner of group I metabotropic glutamate receptor signaling in dorsal horn neurons. Pain 2022; 163:652-664. [PMID: 34252911 PMCID: PMC8741882 DOI: 10.1097/j.pain.0000000000002396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 06/18/2021] [Indexed: 11/25/2022]
Abstract
ABSTRACT Group I metabotropic glutamate receptors (group I mGluRs) have been implicated in several central nervous system diseases including chronic pain. It is known that activation of group I mGluRs results in the production of inositol triphosphate (IP3) and diacylglycerol that leads to activation of extracellular signal-regulated kinases (ERKs) and an increase in neuronal excitability, but how group I mGluRs mediate this process remains unclear. We previously reported that Orai1 is responsible for store-operated calcium entry and plays a key role in central sensitization. However, how Orai1 is activated under physiological conditions is unknown. Here, we tested the hypothesis that group I mGluRs recruit Orai1 as part of its downstream signaling pathway in dorsal horn neurons. We demonstrate that neurotransmitter glutamate induces STIM1 puncta formation, which is not mediated by N-Methyl-D-aspartate (NMDA) or α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. Glutamate-induced Ca2+ entry in the presence of NMDA or AMPA receptor antagonists is eliminated in Orai1-deficient neurons. Dihydroxyphenylglycine (DHPG) (an agonist of group I mGluRs)-induced Ca2+ entry is abolished by Orai1 deficiency, but not affected by knocking down of transient receptor potential cation channel 1 (TRPC1) or TRPC3. Dihydroxyphenylglycine-induced activation of ERKs and modulation of neuronal excitability are abolished in cultured Orai1-deficient neurons. Moreover, DHPG-induced nociceptive behavior is markedly reduced in Orai1-deficient mice. Our findings reveal previously unknown functional coupling between Orai1 and group I mGluRs and shed light on the mechanism underlying group I mGluRs-mediated neuronal plasticity.
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Affiliation(s)
- Jingsheng Xia
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Yannong Dou
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Yixiao Mei
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Frances M. Munoz
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Ruby Gao
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Xinghua Gao
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Daling Li
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Patrick Osei-Owusu
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - James Schiffenhaus
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Alex Bekker
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Yuan-Xiang Tao
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103
| | - Huijuan Hu
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ 07103
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102
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12
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Lu T, Zhang Y, Su Y, Zhou D, Xu Q. Role of store-operated Ca2+ entry in cardiovascular disease. Cell Commun Signal 2022; 20:33. [PMID: 35303866 PMCID: PMC8932232 DOI: 10.1186/s12964-022-00829-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/14/2022] [Indexed: 01/01/2023] Open
Abstract
Store-operated channels (SOCs) are highly selective Ca2+ channels that mediate Ca2+ influx in non-excitable and excitable (i.e., skeletal and cardiac muscle) cells. These channels are triggered by Ca2+ depletion of the endoplasmic reticulum and sarcoplasmic reticulum, independently of inositol 1,4,5-trisphosphate (InsP3), which is involved in cell growth, differentiation, and gene transcription. When the Ca2+ store is depleted, stromal interaction molecule1 (STIM1) as Ca2+ sensor redistributes into discrete puncta near the plasma membrane and activates the protein Ca2+ release activated Ca2+ channel protein 1 (Orai1). Accumulating evidence suggests that SOC is associated with several physiological roles in endothelial dysfunction and vascular smooth muscle proliferation that contribute to the progression of cardiovascular disease. This review mainly elaborates on the contribution of SOC in the vasculature (endothelial cells and vascular smooth muscle cells). We will further retrospect the literature implicating a critical role for these proteins in cardiovascular disease.
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Affiliation(s)
- Ting Lu
- Department of Cardiology, Chongqing Fifth People's Hospital, No. 24 Renji Road, Chongqing, 400000, China
| | - Yihua Zhang
- Department of Cardiology, Chongqing Fifth People's Hospital, No. 24 Renji Road, Chongqing, 400000, China
| | - Yong Su
- Department of Cardiology, Chongqing Fifth People's Hospital, No. 24 Renji Road, Chongqing, 400000, China
| | - Dayan Zhou
- Department of Cardiology, Chongqing Fifth People's Hospital, No. 24 Renji Road, Chongqing, 400000, China
| | - Qiang Xu
- Department of Cardiology, Chongqing Fifth People's Hospital, No. 24 Renji Road, Chongqing, 400000, China.
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13
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Veuthey L, Aliotta A, Bertaggia Calderara D, Pereira Portela C, Alberio L. Mechanisms Underlying Dichotomous Procoagulant COAT Platelet Generation-A Conceptual Review Summarizing Current Knowledge. Int J Mol Sci 2022; 23:ijms23052536. [PMID: 35269679 PMCID: PMC8910683 DOI: 10.3390/ijms23052536] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/19/2022] [Accepted: 02/21/2022] [Indexed: 12/23/2022] Open
Abstract
Procoagulant platelets are a subtype of activated platelets that sustains thrombin generation in order to consolidate the clot and stop bleeding. This aspect of platelet activation is gaining more and more recognition and interest. In fact, next to aggregating platelets, procoagulant platelets are key regulators of thrombus formation. Imbalance of both subpopulations can lead to undesired thrombotic or bleeding events. COAT platelets derive from a common pro-aggregatory phenotype in cells capable of accumulating enough cytosolic calcium to trigger specific pathways that mediate the loss of their aggregating properties and the development of new adhesive and procoagulant characteristics. Complex cascades of signaling events are involved and this may explain why an inter-individual variability exists in procoagulant potential. Nowadays, we know the key agonists and mediators underlying the generation of a procoagulant platelet response. However, we still lack insight into the actual mechanisms controlling this dichotomous pattern (i.e., procoagulant versus aggregating phenotype). In this review, we describe the phenotypic characteristics of procoagulant COAT platelets, we detail the current knowledge on the mechanisms of the procoagulant response, and discuss possible drivers of this dichotomous diversification, in particular addressing the impact of the platelet environment during in vivo thrombus formation.
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14
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Millington-Burgess SL, Harper MT. Epigallocatechin gallate inhibits release of extracellular vesicles from platelets without inhibiting phosphatidylserine exposure. Sci Rep 2021; 11:17678. [PMID: 34480042 PMCID: PMC8417220 DOI: 10.1038/s41598-021-97212-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/12/2021] [Indexed: 02/03/2023] Open
Abstract
Arterial thrombosis triggers myocardial infarction and is a leading cause of death worldwide. Procoagulant platelets, a subpopulation of activated platelets that expose phosphatidylserine (PS), promote coagulation and occlusive thrombosis. Procoagulant platelets may therefore be a therapeutic target. PS exposure in procoagulant platelets requires TMEM16F, a phospholipid scramblase. Epigallocatechin gallate (EGCG) has been reported to inhibit TMEM16F but this has been challenged. We investigated whether EGCG inhibits PS exposure in procoagulant platelets. PS exposure is often measured using fluorophore-conjugated annexin V. EGCG quenched annexin V-FITC fluorescence, which gives the appearance of inhibition of PS exposure. However, EGCG did not quench annexin V-APC fluorescence. Using this fluorophore, we show that EGCG does not inhibit annexin V binding to procoagulant platelets. We confirmed this by using NBD-labelled PS to monitor PS scrambling. EGCG did not quench NBD fluorescence and did not inhibit PS scrambling. Procoagulant platelets also release PS-exposing extracellular vesicles (EVs) that further propagate coagulation. Surprisingly, EGCG inhibited EV release. This inhibition required the gallate group of EGCG. In conclusion, EGCG does not inhibit PS exposure in procoagulant platelets but does inhibit the EV release. Future investigation of this inhibition may help us further understand how EVs are released by procoagulant platelets.
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Affiliation(s)
| | - Matthew T Harper
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK.
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15
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Supramaximal calcium signaling triggers procoagulant platelet formation. Blood Adv 2021; 4:154-164. [PMID: 31935287 DOI: 10.1182/bloodadvances.2019000182] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 12/09/2019] [Indexed: 12/29/2022] Open
Abstract
Procoagulant platelets promote thrombin generation during thrombosis. Platelets become procoagulant in an all-or-nothing manner. We investigated how distinct Ca2+ signaling between platelet subpopulations commits some platelets to become procoagulant, using the high-affinity Ca2+ indicator Fluo-4, which may become saturated during platelet stimulation, or low-affinity Fluo-5N, which reports only very high cytosolic Ca2+ concentrations. All activated platelets had high Fluo-4 fluorescence. However, in Fluo-5N-loaded platelets, only the procoagulant platelets had high fluorescence, indicating very high cytosolic Ca2+. This finding indicates a novel, "supramaximal" Ca2+ signal in procoagulant platelets (ie, much higher than normally considered maximal). Supramaximal Ca2+ signaling and the percentage of procoagulant platelets were inhibited by cyclosporin A, a mitochondrial permeability transition pore blocker, and Ru360, an inhibitor of the mitochondrial Ca2+ uniporter, with no effect on Fluo-4 fluorescence. In contrast, Synta-66, an Orai1 blocker, reduced Fluo-4 fluorescence but did not directly inhibit generation of the supramaximal Ca2+ signal. Our findings show a distinct pattern of Ca2+ signaling in procoagulant platelets and provide a new framework to interpret the role of platelet signaling pathways in procoagulant platelets. This requires reassessment of the role of different Ca2+ channels and may provide new targets to prevent formation of procoagulant platelets and limit thrombosis.
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16
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Podoplelova NA, Nechipurenko DY, Ignatova AA, Sveshnikova AN, Panteleev MA. Procoagulant Platelets: Mechanisms of Generation and Action. Hamostaseologie 2021; 41:146-153. [PMID: 33860522 DOI: 10.1055/a-1401-2706] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
During the past decades, it has been increasingly recognized that the major function of accelerating membrane-dependent reactions of blood coagulation is predominantly implemented by a subset of activated platelets. These procoagulant platelets (also called collagen- and thrombin-activated or COAT, coated, necrotic, although there could be subtle differences between these definitions) are uniquely characterized by both procoagulant activity and, at the same time, inactivated integrins and profibrinolytic properties. The mechanisms of their generation both in vitro and in situ have been increasingly becoming clear, suggesting unique and multidirectional roles in hemostasis and thrombosis. In this mini-review, we shall highlight the existing concepts and challenges in this field.
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Affiliation(s)
- N A Podoplelova
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia.,National Medical Research Center of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, Moscow, Russia
| | - D Y Nechipurenko
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia.,National Medical Research Center of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, Moscow, Russia.,Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia
| | - A A Ignatova
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia.,National Medical Research Center of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, Moscow, Russia
| | - A N Sveshnikova
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia.,National Medical Research Center of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, Moscow, Russia.,Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia
| | - M A Panteleev
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia.,National Medical Research Center of Pediatric Hematology, Oncology and Immunology named after Dmitry Rogachev, Moscow, Russia.,Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia
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17
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Abstract
Platelets are the major cellular contributor to arterial thrombosis. However, activated platelets form two distinct subpopulations during thrombosis. Pro-aggregatory platelets aggregate to form the main body of the thrombus. In contrast, procoagulant platelets expose phosphatidylserine on their outer surface and promote thrombin generation. This apparently all-or-nothing segregation into subpopulations indicates that, during activation, platelets commit to becoming procoagulant or pro-aggregatory. Although the signaling pathways that control this commitment are not understood, distinct cytosolic and mitochondrial Ca2+ signals in different subpopulations are likely to be central. In this review, we discuss how these Ca2+ signals control procoagulant platelet formation and whether this process can be targeted pharmacologically to prevent arterial thrombosis.
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Affiliation(s)
| | - Matthew T Harper
- Department of Pharmacology, University of Cambridge Cambridge, UK
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18
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Fernández DI, Kuijpers MJE, Heemskerk JWM. Platelet calcium signaling by G-protein coupled and ITAM-linked receptors regulating anoctamin-6 and procoagulant activity. Platelets 2020; 32:863-871. [PMID: 33356720 DOI: 10.1080/09537104.2020.1859103] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Most agonists stimulate platelet Ca2+ rises via G-protein coupled receptors (GPCRs) or ITAM-linked receptors (ILRs). Well studied are the GPCRs stimulated by the soluble agonists thrombin (PAR1, PAR4), ADP (P2Y1, P2Y12), and thromboxane A2 (TP), signaling via phospholipase (PLC)β isoforms. The platelet ILRs glycoprotein VI (GPVI), C-type lectin-like receptor 2 (CLEC2), and FcγRIIa are stimulated by adhesive ligands or antibody complexes and signal via tyrosine protein kinases and PLCγ isoforms. Marked differences exist between the GPCR- and ILR-induced Ca2+ signaling in: (i) dependency of tyrosine phosphorylation; (ii) oscillatory versus continued Ca2+ rises by mobilization from the endoplasmic reticulum; and (iii) smaller or larger role of extracellular Ca2+ entry via STIM1/ORAI1. Co-stimulation of both types of receptors, especially by thrombin (PAR1/4) and collagen (GPVI), leads to a highly enforced Ca2+ rise, involving mitochondrial Ca2+ release, which activates the ion and phospholipid channel, anoctamin-6. This highly Ca2+-dependent process causes swelling, ballooning, and phosphatidylserine expression, establishing a unique platelet population swinging between vital and necrotic (procoagulant 'zombie' platelets). Additionally, the high Ca2+ status of procoagulant platelets induces a set of additional events: (i) Ca2+ dependent cleavage of signaling proteins and receptors via calpain and ADAM isoforms; (ii) microvesiculation; (iii) enhanced coagulation factor binding; and (iv) fibrin-coat formation involving transglutaminases. Given the additive roles of GPCR and ILR in Ca2+ signal generation, high-throughput screening of biomolecules or small molecules based on Ca2+ flux measurements provides a promising way to find new inhibitors interfering with prolonged high Ca2+, phosphatidylserine expression, and hence platelet procoagulant activity.
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Affiliation(s)
- Delia I Fernández
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Marijke J E Kuijpers
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
| | - Johan W M Heemskerk
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands
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19
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Aliotta A, Bertaggia Calderara D, Zermatten MG, Alberio L. Sodium-Calcium Exchanger Reverse Mode Sustains Dichotomous Ion Fluxes Required for Procoagulant COAT Platelet Formation. Thromb Haemost 2020; 121:309-321. [PMID: 33099282 DOI: 10.1055/s-0040-171670] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Procoagulant collagen-and-thrombin (COAT)-activated platelets represent a subpopulation of activated platelets, which retain a coat of prohemostatic proteins and express phosphatidylserine on their surface. Dichotomous intracellular signaling generating procoagulant platelet activity instead of traditional aggregating endpoints is still not fully elucidated. It has been demonstrated that secondary messengers such as calcium and sodium play a critical role in platelet activation. Therefore, we developed a flow cytometric analysis to investigate intracellular ion fluxes simultaneously during generation of aggregating and procoagulant platelets. Human platelets were activated by convulxin-plus-thrombin. Cytosolic calcium, sodium, and potassium ion fluxes were visualized by specific ion probes and analyzed by flow cytometry. We observed high and prolonged intracellular calcium concentration, transient sodium increase, and fast potassium efflux in COAT platelets, whereas aggregating non-COAT platelets rapidly decreased their calcium content, maintaining higher cytosolic sodium, and experiencing lower and slower potassium depletion. Considering these antithetical patterns, we investigated the role of the sodium-calcium exchanger (NCX) during convulxin-plus-thrombin activation. NCX inhibitors, CBDMB and ORM-10103, dose-dependently reduced the global calcium mobilization induced by convulxin-plus-thrombin activation and dose-dependently prevented formation of procoagulant COAT platelets. Our data demonstrate that both NCX modes are used after convulxin-plus-thrombin-induced platelet activation. Non-COAT platelets use forward-mode NCX, thus pumping calcium out and moving sodium in, while COAT platelets rely on reverse NCX function, which pumps additional calcium into the cytosol, by extruding sodium. In conclusion, we described for the first time the critical and dichotomous role of NCX function during convulxin-plus-thrombin-induced platelet activation.
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Affiliation(s)
- Alessandro Aliotta
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Debora Bertaggia Calderara
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Maxime G Zermatten
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Lorenzo Alberio
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
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20
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Bacsa B, Tiapko O, Stockner T, Groschner K. Mechanisms and significance of Ca 2+ entry through TRPC channels. CURRENT OPINION IN PHYSIOLOGY 2020; 17:25-33. [PMID: 33210055 PMCID: PMC7116371 DOI: 10.1016/j.cophys.2020.06.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The transient receptor potential (TRP) superfamily of plasma membrane cation channels has been recognized as a signaling hub in highly diverse settings of human physiopathology. In the past three decades of TRP research, attention was focused mainly on the channels Ca2+ signaling function, albeit additional cellular functions, aside of providing a Ca2+ entry pathway, have been identified. Our understanding of Ca2+ signaling by TRP proteins has recently been advanced by a gain in high-resolution structure information on these pore complexes, and by the development of novel tools to investigate their role in spatiotemporal Ca2+ handling. This review summarizes recent discoveries as well as remaining, unresolved aspects of the canonical subfamily of transient receptor potential channels (TRPC) research. We aim at a concise overview on current mechanistic concepts of Ca2+ entry through- and Ca2+ signaling by TRPC channels.
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Affiliation(s)
- Bernadett Bacsa
- Gottfried-Schatz-Research-Center - Biophysics, Medical University of Graz, Neue Stiftingtalstrasse 6/D04, 8010 Graz, Austria
| | - Oleksandra Tiapko
- Gottfried-Schatz-Research-Center - Biophysics, Medical University of Graz, Neue Stiftingtalstrasse 6/D04, 8010 Graz, Austria
| | - Thomas Stockner
- Center for Physiology and Pharmacology, Institute of Pharmacology, Medical University of Vienna, Waehringerstr. 13A, 1090 Vienna, Austria
| | - Klaus Groschner
- Gottfried-Schatz-Research-Center - Biophysics, Medical University of Graz, Neue Stiftingtalstrasse 6/D04, 8010 Graz, Austria
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21
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Millington-Burgess SL, Bonna AM, Rahman T, Harper MT. Ethaninidothioic acid (R5421) is not a selective inhibitor of platelet phospholipid scramblase activity. Br J Pharmacol 2020; 177:4007-4020. [PMID: 32496597 PMCID: PMC7429475 DOI: 10.1111/bph.15152] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/22/2020] [Accepted: 05/25/2020] [Indexed: 12/16/2022] Open
Abstract
Background and Purpose Ethaninidothioic acid (R5421) has been used as a scramblase inhibitor to determine the role of phospholipid scrambling across a range of systems including platelet procoagulant activity. The selectivity of R5421 has not been thoroughly studied. Here, we characterised the effects of R5421 on platelet function and its suitability for use as a scramblase inhibitor. Experimental Approach Human platelet activation was measured following pretreatment with R5421 and stimulation with a range of agonists. Phosphatidylserine exposure was measured using annexin V binding. Integrin αIIbβ3 activation and α‐granule release were measured by flow cytometry. Cytosolic Ca2+ signals were measured using Cal520 fluorescence. An in silico ligand‐based screen identified 16 compounds which were tested in these assays. Key Results R5421 inhibited A23187‐induced phosphatidylserine exposure in a time‐ and temperature‐dependent manner. R5421 inhibited Ca2+ signalling from the PAR1, PAR4 and glycoprotein VI receptors as well as platelet αIIbβ3 integrin activation and α‐granule release. R5421 is therefore not a selective inhibitor of platelet scramblase activity. An in silico screen identified the pesticide thiodicarb as similar to R5421. It also inhibited platelet phosphatidylserine exposure, Ca2+ signalling from the PAR1 and glycoprotein VI, αIIbβ3 activation and α‐granule release. Thiodicarb additionally disrupted Ca2+ homeostasis in unstimulated platelets. Conclusion and Implications R5421 is not a selective inhibitor of platelet scramblase activity. We have identified the pesticide thiodicarb, which had similar effects on platelet function to R5421 as well as additional disruption of Ca2+ signalling which may underlie some of thiodicarb's toxicity.
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Affiliation(s)
| | | | - Taufiq Rahman
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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22
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Aliotta A, Bertaggia Calderara D, Alberio L. Flow Cytometric Monitoring of Dynamic Cytosolic Calcium, Sodium, and Potassium Fluxes Following Platelet Activation. Cytometry A 2020; 97:933-944. [DOI: 10.1002/cyto.a.24017] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 03/23/2020] [Accepted: 03/27/2020] [Indexed: 12/19/2022]
Affiliation(s)
- Alessandro Aliotta
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory Lausanne University Hospital (CHUV) and University of Lausanne (UNIL) Lausanne Switzerland
| | - Debora Bertaggia Calderara
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory Lausanne University Hospital (CHUV) and University of Lausanne (UNIL) Lausanne Switzerland
| | - Lorenzo Alberio
- Hemostasis and Platelet Research Laboratory, Division of Hematology and Central Hematology Laboratory Lausanne University Hospital (CHUV) and University of Lausanne (UNIL) Lausanne Switzerland
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23
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Śledź KM, Moore SF, Durrant TN, Blair TA, Hunter RW, Hers I. Rapamycin restrains platelet procoagulant responses via FKBP-mediated protection of mitochondrial integrity. Biochem Pharmacol 2020; 177:113975. [PMID: 32298692 DOI: 10.1016/j.bcp.2020.113975] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/09/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND PURPOSE Rapamycin is a potent immunosuppressant and anti-proliferative agent used clinically to prevent organ transplant rejection and for coating coronary stents to counteract restenosis. Rapamycin complexes with the immunophilin FKBP12, which subsequently binds and inhibits mTORC1. Despite several reports demonstrating that rapamycin affects platelet-mediated responses, the underlying mechanism of how it alters platelet function is poorly characterised. This study aimed to elucidate the effect of rapamycin on platelet procoagulant responses. EXPERIMENTAL APPROACH The effect of rapamycin on platelet activation and signalling was investigated alongside the catalytic mTOR inhibitors KU0063794 and WYE-687, and the FKBP12-binding macrolide FK506. KEY RESULTS Rapamycin affects platelet procoagulant responses by reducing externalisation of the procoagulant phospholipid phosphatidylserine, formation of balloon-like structures and local generation of thrombin. Catalytic mTOR kinase inhibitors did not alter platelet procoagulant processes, despite having a similar effect as rapamycin on Ca2+ signalling, demonstrating that the effect of rapamycin on procoagulant responses is independent of mTORC1 inhibition and not linked to a reduction in Ca2+ signalling. FK506, which also forms a complex with FKBP12 but does not target mTOR, reduced platelet procoagulant responses to a similar extent as rapamycin. Both rapamycin and FK506 prevented the loss of mitochondria integrity induced by platelet activation, one of the central regulatory events leading to PS externalisation. CONCLUSIONS AND IMPLICATIONS Rapamycin suppresses platelet procoagulant responses by protecting mitochondrial integrity in a manner independent of mTORC1 inhibition. Rapamycin and other drugs targeting FKBP immunophilins could aid the development of novel complementary anti-platelet therapies.
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Affiliation(s)
- Kamila M Śledź
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Samantha F Moore
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Tom N Durrant
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Thomas A Blair
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Roger W Hunter
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom.
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24
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Reddy EC, Rand ML. Procoagulant Phosphatidylserine-Exposing Platelets in vitro and in vivo. Front Cardiovasc Med 2020; 7:15. [PMID: 32195268 PMCID: PMC7062866 DOI: 10.3389/fcvm.2020.00015] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/30/2020] [Indexed: 12/11/2022] Open
Abstract
The physiological heterogeneity of platelets leads to diverse responses and the formation of discrete subpopulations upon platelet stimulation. Procoagulant platelets are an example of such subpopulations, a key characteristic of which is exposure either of the anionic aminophospholipid phosphatidylserine (PS) or of tissue factor on the activated platelet surface. This review focuses on the former, in which PS exposure on a subpopulation of platelets facilitates assembly of the intrinsic tenase and prothrombinase complexes, thereby accelerating thrombin generation on the activated platelet surface, contributing importantly to the hemostatic process. Mechanisms involved in platelet PS exposure, and accompanying events, induced by physiologically relevant agonists are considered then contrasted with PS exposure resulting from intrinsic pathway-mediated apoptosis in platelets. Pathologies of PS exposure, both inherited and acquired, are described. A consideration of platelet PS exposure as an antithrombotic target concludes the review.
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Affiliation(s)
- Emily C Reddy
- Developmental and Stem Cell Biology, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
| | - Margaret L Rand
- Division of Haematology/Oncology, Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.,Departments of Laboratory Medicine & Pathobiology, Biochemistry, and Paediatrics, University of Toronto, Toronto, ON, Canada
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Wei H, Davies JE, Harper MT. 2-Aminoethoxydiphenylborate (2-APB) inhibits release of phosphatidylserine-exposing extracellular vesicles from platelets. Cell Death Discov 2020; 6:10. [PMID: 32140260 PMCID: PMC7051957 DOI: 10.1038/s41420-020-0244-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/03/2019] [Accepted: 12/10/2019] [Indexed: 12/17/2022] Open
Abstract
Activated, procoagulant platelets shed phosphatidylserine (PS)-exposing extracellular vesicles (EVs) from their surface in a Ca2+- and calpain-dependent manner. These PS-exposing EVs are prothrombotic and proinflammatory and are found at elevated levels in many cardiovascular and metabolic diseases. How PS-exposing EVs are shed is not fully understood. A clearer understanding of this process may aid the development of drugs to selectively block their release. In this study we report that 2-aminoethoxydiphenylborate (2-APB) significantly inhibits the release of PS-exposing EVs from platelets stimulated with the Ca2+ ionophore, A23187, or the pore-forming toxin, streptolysin-O. Two analogues of 2-APB, diphenylboronic anhydride (DPBA) and 3-(diphenylphosphino)-1-propylamine (DP3A), inhibited PS-exposing EV release with similar potency. Although 2-APB and DPBA weakly inhibited platelet PS exposure and calpain activity, this was not seen with DP3A despite inhibiting PS-exposing EV release. These data suggest that there is a further target of 2-APB, independent of cytosolic Ca2+ signalling, PS exposure and calpain activity, that is required for PS-exposing EV release. DP3A is likely to inhibit the same target, without these other effects. Identifying the target of 2-APB, DPBA and DP3A may provide a new way to inhibit PS-exposing EV release from activated platelets and inhibit their contribution to thrombosis and inflammation.
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Affiliation(s)
- Hao Wei
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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Wei H, Harper MT. ABT-737 Triggers Caspase-Dependent Inhibition of Platelet Procoagulant Extracellular Vesicle Release during Apoptosis and Secondary Necrosis In Vitro. Thromb Haemost 2019; 119:1665-1674. [PMID: 31493778 PMCID: PMC6768798 DOI: 10.1055/s-0039-1693694] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Platelet lifespan is limited by activation of intrinsic apoptosis. Apoptotic platelets are rapidly cleared from the circulation in vivo. ABT-737 triggers platelet apoptosis and is a useful tool for studying this process. However, in vitro experiments lack clearance mechanisms for apoptotic platelets. To determine whether apoptotic platelets progress to secondary necrosis, apoptosis was triggered in human platelets with ABT-737, a BH3 mimetic. Platelet annexin V (AnV) binding, release of AnV+ extracellular vesicles (EVs), and loss of plasma membrane integrity were monitored by flow cytometry. ABT-737 triggered AnV binding, indicating phosphatidylserine exposure, release of AnV+ EVs, and a slow loss of plasma membrane integrity. The latter suggests that apoptotic platelets progress to secondary necrosis in vitro. These responses were dependent on caspase activation and Ca2+ entry. Surprisingly, although intracellular Ca2+ concentration increased, AnV+ EV release was not dependent on the Ca2+-dependent protease, calpain. On the contrary, ABT-737 downregulated the ability of the Ca2+ ionophore, A23187, to trigger calpain-dependent release of AnV+ EVs. This was dependent on caspase activity as, when caspases were inhibited, ABT-737 increased the ability of A23187 to trigger AnV+ EV release. These data suggest that apoptotic platelets progress to secondary necrosis unless they are cleared. This may affect the interpretation of ABT-737-triggered signaling in platelets in vitro. Ca2+-dependent AnV+ EV release is downregulated during apoptosis in a caspase-dependent manner, which may limit the potential consequences of secondary necrotic platelets.
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Affiliation(s)
- Hao Wei
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | - Matthew T Harper
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
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Wei H, Malcor JDM, Harper MT. Lipid rafts are essential for release of phosphatidylserine-exposing extracellular vesicles from platelets. Sci Rep 2018; 8:9987. [PMID: 29968812 PMCID: PMC6030044 DOI: 10.1038/s41598-018-28363-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 06/21/2018] [Indexed: 12/21/2022] Open
Abstract
Platelets protect the vascular system during damage or inflammation, but platelet activation can result in pathological thrombosis. Activated platelets release a variety of extracellular vesicles (EVs). EVs shed from the plasma membrane often expose phosphatidylserine (PS). These EVs are pro-thrombotic and increased in number in many cardiovascular and metabolic diseases. The mechanisms by which PS-exposing EVs are shed from activated platelets are not well characterised. Cholesterol-rich lipid rafts provide a platform for coordinating signalling through receptors and Ca2+ channels in platelets. We show that cholesterol depletion with methyl-β-cyclodextrin or sequestration with filipin prevented the Ca2+-triggered release of PS-exposing EVs. Although calpain activity was required for release of PS-exposing, calpain-dependent cleavage of talin was not affected by cholesterol depletion. P2Y12 and TPα, receptors for ADP and thromboxane A2, respectively, have been reported to be in platelet lipid rafts. However, the P2Y12 antagonist, AR-C69931MX, or the cyclooxygenase inhibitor, aspirin, had no effect on A23187-induced release of PS-exposing EVs. Together, these data show that lipid rafts are required for release of PS-exposing EVs from platelets.
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Affiliation(s)
- Hao Wei
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom
| | | | - Matthew T Harper
- Department of Pharmacology, University of Cambridge, Cambridge, United Kingdom.
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Kremers BMM, Ten Cate H, Spronk HMH. Pleiotropic effects of the hemostatic system. J Thromb Haemost 2018; 16:S1538-7836(22)02208-5. [PMID: 29851288 DOI: 10.1111/jth.14161] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Indexed: 01/19/2023]
Abstract
Atherothrombosis is characterized by the inflammatory process of atherosclerosis combined with a hypercoagulable state leading to superimposed thrombus formation. In atherosclerotic plaques, cell signaling can occur via protease-activated receptors (PARs), four of which have been identified so far (PAR1-PAR4). Proteases that are able to activate PARs can be produced systemically, but also at the sites of lesions, and they include thrombin and activated factor X. After PAR activation, downstream signaling can lead to both proinflammatory effects and a hypercoagulable state. Which specific effect occurs depends on the type of protease and activated PAR, and the site of activation. Hypercoagulable effects are mainly exerted through PAR1 and PAR4, whereas proinflammatory responses are mostly seen after PAR1 and PAR2 activation. PAR signaling pathways contribute to atherothrombosis, suggesting that inhibition of these pathways possibly prevents cardiovascular events based on this pathophysiological mechanism. In this review, we highlight the pathways by which PAR activation leads to proinflammatory responses and a hypercoagulable state. Furthermore, we give an overview of potential pharmacological treatment targets that promote vascular protection.
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Affiliation(s)
- B M M Kremers
- Departments of Internal Medicine and Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands
| | - H Ten Cate
- Departments of Internal Medicine and Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands
| | - H M H Spronk
- Departments of Internal Medicine and Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, the Netherlands
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López E, Gómez-Gordo L, Cantonero C, Bermejo N, Pérez-Gómez J, Granados MP, Salido GM, Rosado Dionisio JA, Redondo Liberal PC. Stanniocalcin 2 Regulates Non-capacitative Ca 2+ Entry and Aggregation in Mouse Platelets. Front Physiol 2018; 9:266. [PMID: 29628897 PMCID: PMC5876523 DOI: 10.3389/fphys.2018.00266] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 03/08/2018] [Indexed: 12/11/2022] Open
Abstract
Stanniocalcin 2 (STC2) is a fish protein that controls body Ca2+ and phosphate metabolism. STC2 has also been described in mammals, and as platelet function highly depends on both extracellular and intracellular Ca2+, we have explored its expression and function in these cells. STC2−/− mice exhibit shorter tail bleeding time than WT mice. Platelets from STC2-deficient mice showed enhanced aggregation, as well as enhanced Ca2+ mobilization in response to the physiological agonist thrombin (Thr) and the diacylglycerol analog, OAG, a selective activator of the non-capacitative Ca2+ entry channels. Interestingly, platelets from STC2−/− mice exhibit attenuated interaction between STIM1 and Orai1 in response to Thr, thus suggesting that STC2 is required for Thr-evoked STIM1-Orai1 interaction and the subsequent store-operated Ca2+ entry (SOCE). We have further assessed possible changes in the expression of the most relevant channels involved in non-capacitative Ca2+ entry in platelets. Then, protein expression of Orai3, TRPC3 and TRPC6 were evaluated by Western blotting, and the results revealed that while the expression of Orai3 was enhanced in the STC2-deficient mice, others like TRPC3 and TRPC6 remains almost unaltered. Summarizing, our results provide for the first time evidence for a role of STC2 in platelet physiology through the regulation of agonist-induced Ca2+ entry, which might be mediated by the regulation of Orai3 channel expression.
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Affiliation(s)
- Esther López
- Department of Physiology (PHYCELL) of the Veterinary Faculty, University of Extremadura, Cáceres, Spain
| | - L Gómez-Gordo
- Department of Animal Medicine, Veterinary Faculty University of Extremadura, Cáceres, Spain
| | - Carlos Cantonero
- Department of Physiology (PHYCELL) of the Veterinary Faculty, University of Extremadura, Cáceres, Spain
| | - Nuria Bermejo
- Hematology Unit, San Pedro de Alcantara Hospital, Cáceres, Spain
| | - Jorge Pérez-Gómez
- Faculty of Sport Sciences, University of Extremadura, Cáceres, Spain
| | - María P Granados
- Aldea Moret Health Center, Extremadura Health Service, Cáceres, Spain
| | - Gines M Salido
- Institute of Molecular Pathology Biomarkers, Cáceres, Spain
| | - Juan A Rosado Dionisio
- Department of Physiology (PHYCELL) of the Veterinary Faculty, University of Extremadura, Cáceres, Spain
| | - Pedro C Redondo Liberal
- Department of Physiology (PHYCELL) of the Veterinary Faculty, University of Extremadura, Cáceres, Spain
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Howarth FC, Qureshi MA, Jayaprakash P, Parekh K, Oz M, Dobrzynski H, Adrian TE. The Pattern of mRNA Expression Is Changed in Sinoatrial Node from Goto-Kakizaki Type 2 Diabetic Rat Heart. J Diabetes Res 2018; 2018:8454078. [PMID: 30246030 PMCID: PMC6139199 DOI: 10.1155/2018/8454078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 07/16/2018] [Accepted: 08/12/2018] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND In vivo experiments in Goto-Kakizaki (GK) type 2 diabetic rats have demonstrated reductions in heart rate from a young age. The expression of genes encoding more than 70 proteins that are associated with the generation and conduction of electrical activity in the GK sinoatrial node (SAN) have been evaluated to further clarify the molecular basis of the low heart rate. MATERIALS AND METHODS Heart rate and expression of genes were evaluated with an extracellular electrode and real-time RT-PCR, respectively. Rats aged 12-13 months were employed in these experiments. RESULTS Isolated spontaneous heart rate was reduced in GK heart (161 ± 12 bpm) compared to controls (229 ± 11 bpm). There were many differences in expression of mRNA, and some of these differences were of particular interest. Compared to control SAN, expression of some genes were downregulated in GK-SAN: gap junction, Gja1 (Cx43), Gja5 (Cx40), Gjc1 (Cx45), and Gjd3 (Cx31.9); cell membrane transport, Trpc1 (TRPC1) and Trpc6 (TRPC6); hyperpolarization-activated cyclic nucleotide-gated channels, Hcn1 (HCN1) and Hcn4 (HCN4); calcium channels, Cacna1d (Cav1.3), Cacna1g (Cav3.1), Cacna1h (Cav3.2), Cacna2d1 (Cavα2δ1), Cacna2d3 (Cavα2δ3), and Cacng4 (Cav γ 4); and potassium channels, Kcna2 (Kv1.2), Kcna4 (Kv1.4), Kcna5 (Kv1.5), Kcnb1 (Kv2.1), Kcnd3 (Kv4.3), Kcnj2 (Kir2.1), Kcnk1 (TWIK1), Kcnk5 (K2P5.1), Kcnk6 (TWIK2), and Kcnn2 (SK2) whilst others were upregulated in GK-SAN: Ryr2 (RYR2) and Nppb (BNP). CONCLUSIONS This study provides new insight into the changing expression of genes in the sinoatrial node of diabetic heart.
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MESH Headings
- Action Potentials
- Animals
- Arrhythmias, Cardiac/etiology
- Arrhythmias, Cardiac/genetics
- Arrhythmias, Cardiac/metabolism
- Arrhythmias, Cardiac/physiopathology
- Diabetes Mellitus, Type 2/complications
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diabetic Cardiomyopathies/etiology
- Diabetic Cardiomyopathies/genetics
- Diabetic Cardiomyopathies/metabolism
- Diabetic Cardiomyopathies/physiopathology
- Disease Models, Animal
- Gene Expression Regulation
- Heart Rate/genetics
- Isolated Heart Preparation
- Male
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats, Wistar
- Sinoatrial Node/metabolism
- Sinoatrial Node/physiopathology
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Affiliation(s)
- F. C. Howarth
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - M. A. Qureshi
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - P. Jayaprakash
- Department of Pharmacology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - K. Parekh
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - M. Oz
- Department of Pharmacology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - H. Dobrzynski
- Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - T. E. Adrian
- Department of Basic Medical Sciences, Mohammed Bin Rashid University of Medicine & Health Sciences, Dubai, UAE
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Coupling between the TRPC3 ion channel and the NCX1 transporter contributed to VEGF-induced ERK1/2 activation and angiogenesis in human primary endothelial cells. Cell Signal 2017; 37:12-30. [DOI: 10.1016/j.cellsig.2017.05.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/05/2017] [Accepted: 05/18/2017] [Indexed: 12/15/2022]
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Membrane Ballooning in Aggregated Platelets is Synchronised and Mediates a Surge in Microvesiculation. Sci Rep 2017; 7:2770. [PMID: 28584295 PMCID: PMC5459805 DOI: 10.1038/s41598-017-02933-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 04/20/2017] [Indexed: 12/23/2022] Open
Abstract
Human platelet transformation into balloons is part of the haemostatic response and thrombus architecture. Here we reveal that in aggregates of platelets in plasma, ballooning in multiple platelets occurs in a synchronised manner. This suggests a mechanism of coordination between cells, previously unrecognised. We aimed to understand this mechanism, and how it may contribute to thrombus development. Using spinning-disc confocal microscopy we visualised membrane ballooning in human platelet aggregates adherent to collagen-coated surfaces. Within an aggregate, multiple platelets undergo ballooning in a synchronised fashion, dependent upon extracellular calcium, in a manner that followed peak cytosolic calcium levels in the aggregate. Synchrony was observed in platelets within but not between aggregates, suggesting a level of intra-thrombus communication. Blocking phosphatidylserine, inhibiting thrombin or blocking PAR1 receptor, largely prevented synchrony without blocking ballooning itself. In contrast, inhibition of connexins, P2Y12, P2Y1 or thromboxane formation had no effect on synchrony or ballooning. Importantly, synchronised ballooning was closely followed by a surge in microvesicle formation, which was absent when synchrony was blocked. Our data demonstrate that the mechanism underlying synchronised membrane ballooning requires thrombin generation acting effectively in a positive feedback loop, mediating a subsequent surge in procoagulant activity and microvesicle release.
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Lopez JJ, Salido GM, Rosado JA. Cardiovascular and Hemostatic Disorders: SOCE and Ca 2+ Handling in Platelet Dysfunction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:453-472. [PMID: 28900928 DOI: 10.1007/978-3-319-57732-6_23] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Among the Ca2+ entry mechanisms in platelets, store-operated Ca2+ entry (SOCE) plays a prominent role as it is necessary to achieve full activation of platelet functions and replenish intracellular Ca2+ stores. In platelets, as in other non-excitable cells, SOCE has been reported to involve the activation of plasma membrane channels by the ER Ca2+ sensor STIM1. Despite electrophysiological studies are not possible in human platelets, indirect analyses have revealed that the Ca2+-permeable channels involve Orai1 and, most likely, TRPC1 subunits. A relevant role for the latter has not been found in mouse platelets. There is a body of evidence revealing a number of abnormalities in SOCE or in its molecular regulators that result in qualitative platelet disorders and, as a consequence, altered platelet responsiveness upon stimulation with multiple physiological agonists. Platelet SOCE abnormalities include STIM1 and Orai1 mutations. This chapter summarizes the current knowledge in this field, as well as the disorders associated to platelet SOCE dysfunction.
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Affiliation(s)
- Jose J Lopez
- Cell Physiology Research Group, Department of Physiology, University of Extremadura, Cáceres, Spain
| | - Gines M Salido
- Cell Physiology Research Group, Department of Physiology, University of Extremadura, Cáceres, Spain
| | - Juan A Rosado
- Cell Physiology Research Group, Department of Physiology, University of Extremadura, Cáceres, Spain.
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Bavencoffe A, Zhu MX, Tian JB. New Aspects of the Contribution of ER to SOCE Regulation: TRPC Proteins as a Link Between Plasma Membrane Ion Transport and Intracellular Ca2+ Stores. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:239-255. [DOI: 10.1007/978-3-319-57732-6_13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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35
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Sveshnikova AN, Balatskiy AV, Demianova AS, Shepelyuk TO, Shakhidzhanov SS, Balatskaya MN, Pichugin AV, Ataullakhanov FI, Panteleev MA. Systems biology insights into the meaning of the platelet's dual-receptor thrombin signaling. J Thromb Haemost 2016; 14:2045-2057. [PMID: 27513817 DOI: 10.1111/jth.13442] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Indexed: 01/16/2023]
Abstract
Essentials Roles of the two thrombin receptors in platelet signaling are poorly understood. Computational systems biology modeling was used together with continuous flow cytometry. Dual-receptor system has wide-range sensitivity to thrombin and optimal response dynamics. Procoagulant platelet formation is determined by donor-specific activities of the two receptors. SUMMARY Background Activation of human platelets with thrombin proceeds via two protease-activated receptors (PARs), PAR1 and PAR4, that have identical main intracellular signaling responses. Although there is evidence that they have different cleavage/inactivation kinetics (and some secondary variations in signaling), the reason for such redundancy is not clear. Methods We developed a multicompartmental stochastic computational systems biology model of dual-receptor thrombin signaling in platelets to gain insight into the mechanisms and roles of PAR1 and PAR4 functioning. Experiments employing continuous flow cytometry of washed human platelets were used to validate the model and test its predictions. Activity of PAR receptors in donors was evaluated by mRNA measurement and by polymorphism sequencing. Results Although PAR1 activation produced rapid and short-lived response, signaling via PAR4 developed slowly and propagated in time. Response of the dual-receptor system was both rapid and prolonged in time. Inclusion of PAR1/PAR4 heterodimer formation promoted PAR4 signaling in the medium range of thrombin concentration (about 10 nm), with little contribution at high and low thrombin. Different dynamics and dose-dependence of procoagulant platelet formation in healthy donors was associated with individual variations in PAR1 and PAR4 activities and particularly by the Ala120Thr polymorphism in the F2RL3 gene encoding PAR4. Conclusions The dual-receptor combination is critical to produce a response combining three critical advantages: sensitivity to thrombin concentration, rapid onset and steady propagation; specific features of the protease-activated receptors do not allow combination of all three in a single receptor.
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Affiliation(s)
- A N Sveshnikova
- Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia
- Federal Research and Clinical Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
- Therapeutic Faculty, Pirogov Russian National Research Medical University, Moscow, Russia
| | - A V Balatskiy
- Medical Scientific and Educational Center, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Basic Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - A S Demianova
- Federal Research and Clinical Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
| | - T O Shepelyuk
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia
- Federal Research and Clinical Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
- Faculty of Basic Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - S S Shakhidzhanov
- Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia
| | - M N Balatskaya
- Faculty of Basic Medicine, Lomonosov Moscow State University, Moscow, Russia
| | - A V Pichugin
- Institute of Immunology FMBA of Russia, Moscow, Russia
| | - F I Ataullakhanov
- Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia
- Federal Research and Clinical Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia
- Faculty of Biological and Medical Physics, Moscow Institute of Physics and Technology, Dolgoprudnyi, Russia
| | - M A Panteleev
- Faculty of Physics, Lomonosov Moscow State University, Moscow, Russia.
- Center for Theoretical Problems of Physicochemical Pharmacology, Russian Academy of Sciences, Moscow, Russia.
- Federal Research and Clinical Center of Pediatric Hematology, Oncology and Immunology, Moscow, Russia.
- Faculty of Biological and Medical Physics, Moscow Institute of Physics and Technology, Dolgoprudnyi, Russia.
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Wright JR, Amisten S, Goodall AH, Mahaut-Smith MP. Transcriptomic analysis of the ion channelome of human platelets and megakaryocytic cell lines. Thromb Haemost 2016; 116:272-84. [PMID: 27277069 PMCID: PMC5080539 DOI: 10.1160/th15-11-0891] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 04/30/2016] [Indexed: 11/05/2022]
Abstract
Ion channels have crucial roles in all cell types and represent important therapeutic targets. Approximately 20 ion channels have been reported in human platelets; however, no systematic study has been undertaken to define the platelet channelome. These membrane proteins need only be expressed at low copy number to influence function and may not be detected using proteomic or transcriptomic microarray approaches. In our recent work, quantitative real-time PCR (qPCR) provided key evidence that Kv1.3 is responsible for the voltage-dependent K+ conductance of platelets and megakaryocytes. The present study has expanded this approach to assess relative expression of 402 ion channels and channel regulatory genes in human platelets and three megakaryoblastic/erythroleukaemic cell lines. mRNA levels in platelets are low compared to other blood cells, therefore an improved method of isolating platelets was developed. This used a cocktail of inhibitors to prevent formation of leukocyte-platelet aggregates, and a combination of positive and negative immunomagnetic cell separation, followed by rapid extraction of mRNA. Expression of 34 channel-related transcripts was quantified in platelets, including 24 with unknown roles in platelet function, but that were detected at levels comparable to ion channels with established roles in haemostasis or thrombosis. Trace expression of a further 50 ion channel genes was also detected. More extensive channelomes were detected in MEG-01, CHRF-288-11 and HEL cells (195, 185 and 197 transcripts, respectively), but lacked several channels observed in the platelet. These "channelome" datasets provide an important resource for further studies of ion channel function in the platelet and megakaryocyte.
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Affiliation(s)
| | | | | | - Martyn P Mahaut-Smith
- Prof. Martyn Mahaut-Smith, PhD, Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Leicester, LEI 7RH, UK, Tel.: +44 116 229 7135, E-mail:
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Ferdous Z, Qureshi MA, Jayaprakash P, Parekh K, John A, Oz M, Raza H, Dobrzynski H, Adrian TE, Howarth FC. Different Profile of mRNA Expression in Sinoatrial Node from Streptozotocin-Induced Diabetic Rat. PLoS One 2016; 11:e0153934. [PMID: 27096430 PMCID: PMC4838258 DOI: 10.1371/journal.pone.0153934] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 04/06/2016] [Indexed: 11/30/2022] Open
Abstract
Background Experiments in isolated perfused heart have shown that heart rate is lower and sinoatrial node (SAN) action potential duration is longer in streptozotocin (STZ)–induced diabetic rat compared to controls. In sino-atrial preparations the pacemaker cycle length and sino-atrial conduction time are prolonged in STZ heart. To further clarify the molecular basis of electrical disturbances in the diabetic heart the profile of mRNA encoding a wide variety of proteins associated with the generation and transmission of electrical activity has been evaluated in the SAN of STZ-induced diabetic rat heart. Methodology/Principal Findings Heart rate was measured in isolated perfused heart with an extracellular suction electrode. Expression of mRNA encoding a variety of intercellular proteins, intracellular Ca2+-transport and regulatory proteins, cell membrane transport proteins and calcium, sodium and potassium channel proteins were measured in SAN and right atrial (RA) biopsies using real-time reverse transcription polymerase chain reaction techniques. Heart rate was lower in STZ (203±7 bpm) compared to control (239±11 bpm) rat. Among many differences in the profile of mRNA there are some worthy of particular emphasis. Expression of genes encoding some proteins were significantly downregulated in STZ-SAN: calcium channel, Cacng4 (7-fold); potassium channel, Kcnd2 whilst genes encoding some other proteins were significantly upregulated in STZ-SAN: gap junction, Gjc1; cell membrane transport, Slc8a1, Trpc1, Trpc6 (4-fold); intracellular Ca2+-transport, Ryr3; calcium channel Cacna1g, Cacna1h, Cacnb3; potassium channels, Kcnj5, Kcnk3 and natriuretic peptides, Nppa (5-fold) and Nppb (7-fold). Conclusions/Significance Collectively, this study has demonstrated differences in the profile of mRNA encoding a variety of proteins that are associated with the generation, conduction and regulation of electrical signals in the SAN of STZ-induced diabetic rat heart. Data from this study will provide a basis for a substantial range of future studies to investigate whether these changes in mRNA translate into changes in electrophysiological function.
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Affiliation(s)
- Zannatul Ferdous
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Muhammad Anwar Qureshi
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Petrilla Jayaprakash
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Khatija Parekh
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Annie John
- Department of Biochemistry, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Murat Oz
- Department of Pharmacology, College of Medicine & Health Sciences, UAE University, Al AIn, UAE
| | - Haider Raza
- Department of Biochemistry, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
| | - Halina Dobrzynski
- Institute of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Thomas Edward Adrian
- Department of Physiology, College of Medicine & Health Sciences, UAE University, Al Ain, UAE
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Bevers EM, Williamson PL. Getting to the Outer Leaflet: Physiology of Phosphatidylserine Exposure at the Plasma Membrane. Physiol Rev 2016; 96:605-45. [PMID: 26936867 DOI: 10.1152/physrev.00020.2015] [Citation(s) in RCA: 287] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Phosphatidylserine (PS) is a major component of membrane bilayers whose change in distribution between inner and outer leaflets is an important physiological signal. Normally, members of the type IV P-type ATPases spend metabolic energy to create an asymmetric distribution of phospholipids between the two leaflets, with PS confined to the cytoplasmic membrane leaflet. On occasion, membrane enzymes, known as scramblases, are activated to facilitate transbilayer migration of lipids, including PS. Recently, two proteins required for such randomization have been identified: TMEM16F, a scramblase regulated by elevated intracellular Ca(2+), and XKR8, a caspase-sensitive protein required for PS exposure in apoptotic cells. Once exposed at the cell surface, PS regulates biochemical reactions involved in blood coagulation, and bone mineralization, and also regulates a variety of cell-cell interactions. Exposed on the surface of apoptotic cells, PS controls their recognition and engulfment by other cells. This process is exploited by parasites to invade their host, and in specialized form is used to maintain photoreceptors in the eye and modify synaptic connections in the brain. This review discusses what is known about the mechanism of PS exposure at the surface of the plasma membrane of cells, how actors in the extracellular milieu sense surface exposed PS, and how this recognition is translated to downstream consequences of PS exposure.
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Affiliation(s)
- Edouard M Bevers
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands; and Department of Biology, Amherst College, Amherst, Massachusetts
| | - Patrick L Williamson
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands; and Department of Biology, Amherst College, Amherst, Massachusetts
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Mattheij NJA, Braun A, van Kruchten R, Castoldi E, Pircher J, Baaten CCFMJ, Wülling M, Kuijpers MJE, Köhler R, Poole AW, Schreiber R, Vortkamp A, Collins PW, Nieswandt B, Kunzelmann K, Cosemans JMEM, Heemskerk JWM. Survival protein anoctamin-6 controls multiple platelet responses including phospholipid scrambling, swelling, and protein cleavage. FASEB J 2016; 30:727-37. [PMID: 26481309 DOI: 10.1096/fj.15-280446] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Accepted: 10/05/2015] [Indexed: 11/11/2022]
Abstract
Scott syndrome is a rare bleeding disorder, characterized by altered Ca(2+)-dependent platelet signaling with defective phosphatidylserine (PS) exposure and microparticle formation, and is linked to mutations in the ANO6 gene, encoding anoctamin (Ano)6. We investigated how the complex platelet phenotype of this syndrome is linked to defective expression of Anos or other ion channels. Mice were generated with heterozygous of homozygous deficiency in Ano6, Ano1, or Ca(2+)-dependent KCa3.1 Gardos channel. Platelets from these mice were extensively analyzed on molecular functions and compared with platelets from a patient with Scott syndrome. Deficiency in Ano1 or Gardos channel did not reduce platelet responses compared with control mice (P > 0.1). In 2 mouse strains, deficiency in Ano6 resulted in reduced viability with increased bleeding time to 28.6 min (control 6.4 min, P < 0.05). Platelets from the surviving Ano6-deficient mice resembled platelets from patients with Scott syndrome in: 1) normal collagen-induced aggregate formation (P > 0.05) with reduced PS exposure (-65 to 90%); 2) lowered Ca(2+)-dependent swelling (-80%) and membrane blebbing (-90%); 3) reduced calpain-dependent protein cleavage (-60%); and 4) moderately affected apoptosis-dependent PS exposure. In conclusion, mouse deficiency of Ano6 but not of other channels affects viability and phenocopies the complex changes in platelets from hemostatically impaired patients with Scott syndrome.
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Affiliation(s)
- Nadine J A Mattheij
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Attila Braun
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Roger van Kruchten
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Elisabetta Castoldi
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Joachim Pircher
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Constance C F M J Baaten
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Manuela Wülling
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Marijke J E Kuijpers
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Ralf Köhler
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Alastair W Poole
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Rainer Schreiber
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Andrea Vortkamp
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Peter W Collins
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Bernhard Nieswandt
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Karl Kunzelmann
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Judith M E M Cosemans
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Johan W M Heemskerk
- *Department of Cell Biochemistry of Thrombosis and Haemostasis Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, Maastricht, The Netherlands; Department of Experimental Biomedicine, University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, Germany; Walter Brendel Centre of Experimental Medicine and German Centre of Cardiovascular Research, Munich Heart Alliance, Ludwig-Maximilians-Universität München, München, Germany; Department of Developmental Biology, Centre for Medical Biotechnology, University of Duisburg-Essen, Duisburg-Essen, Germany; Aragon Institute of Health Sciences I+CS/IIS and ARAID, Zaragoza, Spain; School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom; Institute of Physiology, University of Regensburg, Regensburg, Germany; **Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, Cardiff, United Kingdom
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40
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Ramanathan G, Mannhalter C. Increased expression of transient receptor potential canonical 6 (TRPC6) in differentiating human megakaryocytes. Cell Biol Int 2016; 40:223-31. [PMID: 26514329 DOI: 10.1002/cbin.10558] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 10/28/2015] [Indexed: 12/22/2022]
Abstract
Members of the transient receptor potential (TRP) family of cation conducting channels are found in several tissues and cell types where they have different physiological functions. The canonical TRP channel 6 (TRPC6) is present on the platelet membrane and appears to participate in calcium influx during platelet activation. However, limited information is available on the importance of TRPC channels in megakaryocytes (MKs), the precursor cells of platelets. We determined the mRNA and protein expression of TRPC family members and investigated the role of TRPC6 for proliferation and differentiation of human MKs derived from CD34+ progenitor cells. TRPC6 transcripts were highly expressed during the differentiation of MKs and TRPC6 protein was detectable in MK cytoplasm by confocal staining. TRPC6 channel activity was modulated by pharmacological approaches using flufenamic acid (FFA) for activation and SKF96365 for inhibition. Upon FFA stimulation in MKs, an increase in intracellular calcium was observed, which was blocked by SKF96365 at 10 µM concentration. Incubation of MKs with SKF96365 resulted in a reduction in thrombopoietin-stimulated cell proliferation. Our results suggest a role of TRPC6 in calcium homeostasis during MK development, particularly for cell proliferation.
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Affiliation(s)
| | - Christine Mannhalter
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
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41
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Bouron A, Chauvet S, Dryer S, Rosado JA. Second Messenger-Operated Calcium Entry Through TRPC6. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 898:201-49. [PMID: 27161231 DOI: 10.1007/978-3-319-26974-0_10] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Canonical transient receptor potential 6 (TRPC6) proteins assemble into heteromultimeric structures forming non-selective cation channels. In addition, many TRPC6-interacting proteins have been identified like some enzymes, channels, pumps, cytoskeleton-associated proteins, immunophilins, or cholesterol-binding proteins, indicating that TRPC6 are engaged into macromolecular complexes. Depending on the cell type and the experimental conditions used, TRPC6 activity has been reported to be controlled by diverse modalities. For instance, the second messenger diacylglycerol, store-depletion, the plant extract hyperforin or H2O2 have all been shown to trigger the opening of TRPC6 channels. A well-characterized consequence of TRPC6 activation is the elevation of the cytosolic concentration of Ca(2+). This latter response can reflect the entry of Ca(2+) through open TRPC6 channels but it can also be due to the Na(+)/Ca(2+) exchanger (operating in its reverse mode) or voltage-gated Ca(2+) channels (recruited in response to a TRPC6-mediated depolarization). Although TRPC6 controls a diverse array of biological functions in many tissues and cell types, its pathophysiological functions are far from being fully understood. This chapter covers some key features of TRPC6, with a special emphasis on their biological significance in kidney and blood cells.
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Affiliation(s)
- Alexandre Bouron
- Université Grenoble Alpes, 38000, Grenoble, France. .,CNRS, iRTSV-LCBM, 38000, Grenoble, France.
| | - Sylvain Chauvet
- Université Grenoble Alpes, 38000, Grenoble, France.,CNRS, iRTSV-LCBM, 38000, Grenoble, France
| | - Stuart Dryer
- University of Houston, Houston, TX, USA.,Baylor College of Medicine, Houston, TX, USA
| | - Juan A Rosado
- Departamento de Fisiología, University of Extremadura, Cáceres, Spain
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Berna-Erro A, Jardín I, Smani T, Rosado JA. Regulation of Platelet Function by Orai, STIM and TRP. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 898:157-81. [PMID: 27161229 DOI: 10.1007/978-3-319-26974-0_8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Agonist-induced changes in cytosolic Ca(2+) concentration ([Ca(2+)]c) are central events in platelet physiology. A major mechanism supporting agonist-induced Ca(2+) signals is store-operated Ca(2+) entry (SOCE), where the Ca(2+) sensor STIM1 and the channels of the Orai family, as well as TRPC members are the key elements. STIM1-dependent SOCE plays a major role in collagen-stimulated Ca(2+) signaling, phosphatidylserine exposure and thrombin generation. Furthermore, studies involving Orai1 gain-of-function mutants and platelets from Orai1-deficient mice have revealed the importance of this channel in thrombosis and hemostasis to those found in STIM1-deficient mice indicating that SOCE might play a prominent role in thrombus formation. Moreover, increase in TRPC6 expression might lead to thrombosis in humans. The role of STIM1, Orai1 and TRPCs, and thus SOCE, in thrombus formation, suggests that therapies directed against SOCE and targeting these molecules during cardiovascular and cerebrovascular events could significantly improve traditional anti-thrombotic treatments.
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Affiliation(s)
- Alejandro Berna-Erro
- Laboratory of Molecular Physiology and Channelopathies, Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Barcelona, 08003, Spain
| | - Isaac Jardín
- Department of Physiology (Cell Physiology Research Group), University of Extremadura, Cáceres, 10003, Spain
| | - Tarik Smani
- Department of Medical Physiology and Biophysic, Institute of Biomedicine of Seville (IBiS), University Hospital of Virgen del Rocío/CSIC/University of Seville, Sevilla, 41013, Spain
| | - Juan A Rosado
- Departamento de Fisiología, University of Extremadura, Cáceres, Spain.
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Agbani EO, van den Bosch MTJ, Brown E, Williams CM, Mattheij NJA, Cosemans JMEM, Collins PW, Heemskerk JWM, Hers I, Poole AW. Coordinated Membrane Ballooning and Procoagulant Spreading in Human Platelets. Circulation 2015; 132:1414-24. [PMID: 26330411 DOI: 10.1161/circulationaha.114.015036] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 07/30/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Platelets are central to the process of hemostasis, rapidly aggregating at sites of blood vessel injury and acting as coagulation nidus sites. On interaction with the subendothelial matrix, platelets are transformed into balloonlike structures as part of the hemostatic response. It remains unclear, however, how and why platelets generate these structures. We set out to determine the physiological relevance and cellular and molecular mechanisms underlying platelet membrane ballooning. METHODS AND RESULTS Using 4-dimensional live-cell imaging and electron microscopy, we show that human platelets adherent to collagen are transformed into phosphatidylserine-exposing balloonlike structures with expansive macro/microvesiculate contact surfaces, by a process that we termed procoagulant spreading. We reveal that ballooning is mechanistically and structurally distinct from membrane blebbing and involves disruption to the platelet microtubule cytoskeleton and inflation through fluid entry. Unlike blebbing, procoagulant ballooning is irreversible and a consequence of Na(+), Cl(-), and water entry. Furthermore, membrane ballooning correlated with microparticle generation. Inhibition of Na(+), Cl(-), or water entry impaired ballooning, procoagulant spreading, and microparticle generation, and it also diminished local thrombin generation. Human Scott syndrome platelets, which lack expression of Ano-6, also showed a marked reduction in membrane ballooning, consistent with a role for chloride entry in the process. Finally, the blockade of water entry by acetazolamide attenuated ballooning in vitro and markedly suppressed thrombus formation in vivo in a mouse model of thrombosis. CONCLUSIONS Ballooning and procoagulant spreading of platelets are driven by fluid entry into the cells, and are important for the amplification of localized coagulation in thrombosis.
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Affiliation(s)
- Ejaife O Agbani
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.).
| | - Marion T J van den Bosch
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Ed Brown
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Christopher M Williams
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Nadine J A Mattheij
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Judith M E M Cosemans
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Peter W Collins
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Johan W M Heemskerk
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Ingeborg Hers
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Alastair W Poole
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.).
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From GTP and G proteins to TRPC channels: a personal account. J Mol Med (Berl) 2015; 93:941-53. [PMID: 26377676 DOI: 10.1007/s00109-015-1328-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/28/2015] [Indexed: 10/23/2022]
Abstract
By serendipity and good fortune, as a postdoctoral fellow in 1967, I landed at the right place at the right time, as I was allowed to investigate the mechanism by which hormones activate the enzyme adenylyl cyclase (then adenyl cyclase) in Martin Rodbell's Laboratory at the NIH in Bethesda, Maryland. The work uncovered first, the existence of receptors separate from the enzyme and then, the existence of transduction mechanisms requiring guanosine-5'-triphosphate (GTP) and Mg(2+). With my laboratory colleagues first and postdoctoral fellows after leaving NIH, I participated in the development of the field "signal transduction by G proteins," uncovered by molecular cloning several G-protein-coupled receptors (GPCRs) and became interested in both the molecular makeup of voltage-gated Ca channels and Ca2+ homeostasis downstream of activation of phospholipase C (PLC) by the Gq/11 signaling pathway. We were able to confirm the hypothesis that there would be mammalian homologues of the Drosophila "transient receptor potential" channel and discovered the existence of six of the seven mammalian genes, now called transient receptor potential canonical (TRPC) channels. In the present article, I summarize from a bird's eye view of what I feel were key findings along this path, not only from my laboratory but also from many others, that allowed for the present knowledge of cell signaling involving G proteins to evolve. Towards the end, I summarize roles of TRPC channels in health and disease.
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Maier T, Follmann M, Hessler G, Kleemann HW, Hachtel S, Fuchs B, Weissmann N, Linz W, Schmidt T, Löhn M, Schroeter K, Wang L, Rütten H, Strübing C. Discovery and pharmacological characterization of a novel potent inhibitor of diacylglycerol-sensitive TRPC cation channels. Br J Pharmacol 2015; 172:3650-60. [PMID: 25847402 DOI: 10.1111/bph.13151] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 03/06/2015] [Accepted: 03/28/2015] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND AND PURPOSE The cation channel transient receptor potential canonical (TRPC) 6 has been associated with several pathologies including focal segmental glomerulosclerosis, pulmonary hypertension and ischaemia reperfusion-induced lung oedema. We set out to discover novel inhibitors of TRPC6 channels and investigate the therapeutic potential of these agents. EXPERIMENTAL APPROACH A library of potential TRPC channel inhibitors was designed and synthesized. Activity of the compounds was assessed by measuring intracellular Ca(2+) levels. The lead compound SAR7334 was further characterized by whole-cell patch-clamp techniques. The effects of SAR7334 on acute hypoxic pulmonary vasoconstriction (HPV) and systemic BP were investigated. KEY RESULTS SAR7334 inhibited TRPC6, TRPC3 and TRPC7-mediated Ca(2+) influx into cells with IC50 s of 9.5, 282 and 226 nM, whereas TRPC4 and TRPC5-mediated Ca(2+) entry was not affected. Patch-clamp experiments confirmed that the compound blocked TRPC6 currents with an IC50 of 7.9 nM. Furthermore, SAR7334 suppressed TRPC6-dependent acute HPV in isolated perfused lungs from mice. Pharmacokinetic studies of SAR7334 demonstrated that the compound was suitable for chronic oral administration. In an initial short-term study, SAR7334 did not change mean arterial pressure in spontaneously hypertensive rats (SHR). CONCLUSIONS AND IMPLICATIONS Our results confirm the role of TRPC6 channels in hypoxic pulmonary vasoregulation and indicate that these channels are unlikely to play a major role in BP regulation in SHR. SAR7334 is a novel, highly potent and bioavailable inhibitor of TRPC6 channels that opens new opportunities for the investigation of TRPC channel function in vivo.
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Affiliation(s)
- T Maier
- Sanofi R&D, Frankfurt am Main, Germany
| | | | - G Hessler
- Sanofi R&D, Frankfurt am Main, Germany
| | | | - S Hachtel
- Sanofi R&D, Frankfurt am Main, Germany
| | - B Fuchs
- Excellencecluster Cardio-Pulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - N Weissmann
- Excellencecluster Cardio-Pulmonary System (ECCPS), Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Justus-Liebig-University, Giessen, Germany
| | - W Linz
- Sanofi R&D, Frankfurt am Main, Germany
| | - T Schmidt
- Sanofi R&D, Frankfurt am Main, Germany
| | - M Löhn
- Sanofi R&D, Frankfurt am Main, Germany
| | | | - L Wang
- Sanofi R&D, Frankfurt am Main, Germany
| | - H Rütten
- Sanofi R&D, Frankfurt am Main, Germany
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Andrikopoulos P, Kieswich J, Harwood SM, Baba A, Matsuda T, Barbeau O, Jones K, Eccles SA, Yaqoob MM. Endothelial Angiogenesis and Barrier Function in Response to Thrombin Require Ca2+ Influx through the Na+/Ca2+ Exchanger. J Biol Chem 2015; 290:18412-28. [PMID: 25979335 DOI: 10.1074/jbc.m114.628156] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Indexed: 01/11/2023] Open
Abstract
Thrombin acts on the endothelium by activating protease-activated receptors (PARs). The endothelial thrombin-PAR system becomes deregulated during pathological conditions resulting in loss of barrier function and a pro-inflammatory and pro-angiogenic endothelial phenotype. We reported recently that the ion transporter Na(+)/Ca(2+) exchanger (NCX) operating in the Ca(2+)-influx (reverse) mode promoted ERK1/2 activation and angiogenesis in vascular endothelial growth factor-stimulated primary human vascular endothelial cells. Here, we investigated whether Ca(2+) influx through NCX was involved in ERK1/2 activation, angiogenesis, and endothelial barrier dysfunction in response to thrombin. Reverse-mode NCX inhibitors and RNAi-mediated NCX1 knockdown attenuated ERK1/2 phosphorylation in response to thrombin or an agonist of PAR-1, the main endothelial thrombin receptor. Conversely, promoting reverse-mode NCX by suppressing Na(+)-K(+)-ATPase activity enhanced ERK1/2 activation. Reverse-mode NCX inhibitors and NCX1 siRNA suppressed thrombin-induced primary human vascular endothelial cell angiogenesis, quantified as proliferation and tubular differentiation. Reverse-mode NCX inhibitors or NCX1 knockdown preserved barrier integrity upon thrombin stimulation in vitro. Moreover, the reverse-mode NCX inhibitor SEA0400 suppressed Evans' blue albumin extravasation to the lung and kidneys and attenuated edema formation and ERK1/2 activation in the lungs of mice challenged with a peptide activator of PAR-1. Mechanistically, thrombin-induced ERK1/2 activation required NADPH oxidase 2-mediated reactive oxygen species (ROS) production, and reverse-mode NCX inhibitors and NCX1 siRNA suppressed thrombin-induced ROS production. We propose that reverse-mode NCX is a novel mechanism contributing to thrombin-induced angiogenesis and hyperpermeability by mediating ERK1/2 activation in a ROS-dependent manner. Targeting reverse-mode NCX could be beneficial in pathological conditions involving unregulated thrombin signaling.
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Affiliation(s)
- Petros Andrikopoulos
- From Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary's University of London, London EC1M 6BQ, United Kingdom,
| | - Julius Kieswich
- From Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary's University of London, London EC1M 6BQ, United Kingdom
| | - Steven M Harwood
- From Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary's University of London, London EC1M 6BQ, United Kingdom
| | - Akemichi Baba
- the Hyogo University of Health Sciences, 1-3-6 Minatojima, Chuo-ku, Kobe-shi, Hyogo 650-8530, Japan
| | - Toshio Matsuda
- the Laboratory of Medicinal Pharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan, and
| | - Olivier Barbeau
- the Division of Cancer Therapeutics, Institute of Cancer Research, London SW7 3RP, United Kingdom
| | - Keith Jones
- the Division of Cancer Therapeutics, Institute of Cancer Research, London SW7 3RP, United Kingdom
| | - Suzanne A Eccles
- the Division of Cancer Therapeutics, Institute of Cancer Research, London SW7 3RP, United Kingdom
| | - Muhammad M Yaqoob
- From Translational Medicine and Therapeutics, William Harvey Research Institute, Barts and the London School of Medicine, Queen Mary's University of London, London EC1M 6BQ, United Kingdom
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Phosphatidylinositol-3,4,5-trisphosphate stimulates Ca(2+) elevation and Akt phosphorylation to constitute a major mechanism of thromboxane A2 formation in human platelets. Cell Signal 2015; 27:1488-98. [PMID: 25797048 DOI: 10.1016/j.cellsig.2015.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 02/18/2015] [Accepted: 03/04/2015] [Indexed: 11/23/2022]
Abstract
Phosphatidylinositol trisphosphate (PIP3) has been implicated in many platelet functions however many of the mechanisms need clarification. We have used cell permeable analogues of PIP3,1-O-(1,2-di-palmitoyl-sn-glyero-3-O-phosphoryl)-D-myo-inositol-3,4,5-trisphosphate (DiC16-PIP3) or 1-O-(1,2-di-octanoyl-sn-glyero-3-O-phosphoryl)-D-myo-inositol-3,4,5-trisphosphate (DiC8-PIP3) to study their effects on activation on washed human platelets. Addition of either DiC8- or DiC16-PIP3 to human platelets induced aggregation in the presence of extracellular Ca(2+). This was reduced by the presence of indomethacin, the phospholipase C inhibitor U73122 and apyrase. DiC8-PIP3 induced the phosphorylation of Akt-Ser(473) which was reduced by the Akt inhibitor IV, wortmannin and EGTA (suggesting a dependence on Ca(2+) entry). In Fura2 loaded platelets DiC8-PIP3 was effective at increasing intracellular Ca(2+) in a distinct and transient manner that was reduced in the presence of indomethacin, U73122 and 2-aminoethyl diphenylborinate (2APB). Ca(2+) elevation was reduced by the non-SOCE inhibitor LOE908 and also by the SOCE inhibitor BTP2. DiC8-PIP3 induced the release of Ca(2+) from stores which was not affected by the proton dissipating agent bafilomycin A1 and was more potent than the two-pore channel agonist DiC8-PI[3,5]P2 suggesting release from an endoplasmic reticulum type store. DiC8-PIP3 weakly induced the tyrosine phosphorylation of Syk but not of PLCγ2. Finally like thrombin DiC8-PIP3 induced the formation of thromboxane B2 that was inhibited by the Akt inhibitor IV. These studies suggest that PIP3 via Ca(2+) elevation and Akt phosphorylation forms a central role in thromboxane A2 formation and the amplification of platelet activation.
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Sveshnikova AN, Ataullakhanov FI, Panteleev MA. Compartmentalized calcium signaling triggers subpopulation formation upon platelet activation through PAR1. MOLECULAR BIOSYSTEMS 2015; 11:1052-60. [DOI: 10.1039/c4mb00667d] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A computational model of PAR1-stimulated platelet calcium signaling is developed to analyze the formation of platelet subpopulations. This occurs via a mitochondria-dependent decision-making mechanism. This is a stochastic phenomenon caused by a small number of PARs.
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Affiliation(s)
- Anastasia N. Sveshnikova
- Physics Department
- Moscow State University
- Moscow
- Russia
- Center for Theoretical Problems of Physicochemical Pharmacology
| | - Fazoil I. Ataullakhanov
- Physics Department
- Moscow State University
- Moscow
- Russia
- Center for Theoretical Problems of Physicochemical Pharmacology
| | - Mikhail A. Panteleev
- Physics Department
- Moscow State University
- Moscow
- Russia
- Center for Theoretical Problems of Physicochemical Pharmacology
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Protonophore properties of hyperforin are essential for its pharmacological activity. Sci Rep 2014; 4:7500. [PMID: 25511254 PMCID: PMC4266863 DOI: 10.1038/srep07500] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 11/27/2014] [Indexed: 12/13/2022] Open
Abstract
Hyperforin is a pharmacologically active component of the medicinal plant Hypericum perforatum (St. John's wort), recommended as a treatment for a range of ailments including mild to moderate depression. Part of its action has been attributed to TRPC6 channel activation. We found that hyperforin induces TRPC6-independent H+ currents in HEK-293 cells, cortical microglia, chromaffin cells and lipid bilayers. The latter demonstrates that hyperforin itself acts as a protonophore. The protonophore activity of hyperforin causes cytosolic acidification, which strongly depends on the holding potential, and which fuels the plasma membrane sodium-proton exchanger. Thereby the free intracellular sodium concentration increases and the neurotransmitter uptake by Na+ cotransport is inhibited. Additionally, hyperforin depletes and reduces loading of large dense core vesicles in chromaffin cells, which requires a pH gradient in order to accumulate monoamines. In summary the pharmacological actions of the “herbal Prozac” hyperforin are essentially determined by its protonophore properties shown here.
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Agonist-induced platelet procoagulant activity requires shear and a Rac1-dependent signaling mechanism. Blood 2014; 124:1957-67. [PMID: 25079357 DOI: 10.1182/blood-2014-03-560821] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Activated platelets facilitate blood coagulation by exposing phosphatidylserine (PS) and releasing microvesicles (MVs). However, the potent physiological agonists thrombin and collagen poorly induce PS exposure when a single agonist is used. To obtain a greater procoagulant response, thrombin is commonly used in combination with glycoprotein VI agonists. However, even under these conditions, only a percentage of platelets express procoagulant activity. To date, it remains unclear why platelets poorly expose PS even when stimulated with multiple agonists and what the signaling pathways are of soluble agonist-induced platelet procoagulant activity. Here we show that physiological levels of shear present in blood significantly enhance agonist-induced platelet PS exposure and MV release, enabling low doses of a single agonist to induce full-scale platelet procoagulant activity. PS exposed on the platelet surface was immediately released as MVs, revealing a tight coupling between the 2 processes under shear. Using platelet-specific Rac1(-/-) mice, we discovered that Rac1 plays a common role in mediating the low-dose agonist-induced procoagulant response independent of platelet aggregation, secretion, and the apoptosis pathway. Platelet-specific Rac1 function was not only important for coagulation in vitro but also for fibrin accumulation in vivo following laser-induced arteriolar injury.
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