1
|
O'Donoghue L, Smolenski A. Roles of G proteins and their GTPase-activating proteins in platelets. Biosci Rep 2024; 44:BSR20231420. [PMID: 38808367 PMCID: PMC11139668 DOI: 10.1042/bsr20231420] [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: 11/17/2023] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 05/30/2024] Open
Abstract
Platelets are small anucleate blood cells supporting vascular function. They circulate in a quiescent state monitoring the vasculature for injuries. Platelets adhere to injury sites and can be rapidly activated to secrete granules and to form platelet/platelet aggregates. These responses are controlled by signalling networks that include G proteins and their regulatory guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Recent proteomics studies have revealed the complete spectrum of G proteins, GEFs, and GAPs present in platelets. Some of these proteins are specific for platelets and very few have been characterised in detail. GEFs and GAPs play a major role in setting local levels of active GTP-bound G proteins in response to activating and inhibitory signals encountered by platelets. Thus, GEFs and GAPs are highly regulated themselves and appear to integrate G protein regulation with other cellular processes. This review focuses on GAPs of small G proteins of the Arf, Rab, Ras, and Rho families, as well as of heterotrimeric G proteins found in platelets.
Collapse
Affiliation(s)
- Lorna O'Donoghue
- UCD School of Medicine, University College Dublin, UCD Conway Institute, Belfield, Dublin 4, Ireland
- Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, 123 St. Stephen’s Green 123, Dublin 2, Ireland
| | - Albert Smolenski
- UCD School of Medicine, University College Dublin, UCD Conway Institute, Belfield, Dublin 4, Ireland
- Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, 123 St. Stephen’s Green 123, Dublin 2, Ireland
| |
Collapse
|
2
|
Gupta S, Cooper M, Zhao X, Yarman Y, Thomson H, DeHelian D, Brass LF, Ma P. A regulatory node involving Gα q, PLCβ, and RGS proteins modulates platelet reactivity to critical agonists. J Thromb Haemost 2023; 21:3633-3639. [PMID: 37657560 PMCID: PMC10840692 DOI: 10.1016/j.jtha.2023.08.022] [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: 06/16/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 09/03/2023]
Abstract
BACKGROUND Most platelet agonists work through G protein-coupled receptors, activating pathways that involve members of the Gq, Gi, and G12/G13 families of heterotrimeric G proteins. Gq signaling has been shown to be critical for efficient platelet activation. Growing evidence suggests that regulatory mechanisms converge on G protein-coupled receptors and Gq to prevent overly robust platelet reactivity. OBJECTIVES To identify and characterize mechanisms by which Gq signaling is regulated in platelets. METHODS Based on our prior experience with a Gαi2 variant that escapes regulation by regulator of G protein signaling (RGS) proteins, a Gαq variant was designed with glycine 188 replaced with serine (G188S) and then incorporated into a mouse line so that its effects on platelet activation and thrombus formation could be studied in vitro and in vivo. RESULTS AND CONCLUSIONS As predicted, the G188S substitution in Gαq disrupted its interaction with RGS18. Unexpectedly, it also uncoupled PLCβ-3 from activation by platelet agonists as evidenced by a loss rather than a gain of platelet function in vitro and in vivo. Binding studies showed that in addition to preventing the binding of RGS18 to Gαq, the G188S substitution also prevented the binding of PLCβ-3 to Gαq. Structural analysis revealed that G188 resides in the region that is also important for Gαq binding to PLCβ-3 in platelets. We conclude that the Gαq signaling node is more complex than that has been previously understood, suggesting that there is cross-talk between RGS proteins and PLCβ-3 in the context of Gαq signaling.
Collapse
Affiliation(s)
- Shuchi Gupta
- Department of Medicine and the Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Matthew Cooper
- Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Xuefei Zhao
- Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Yanki Yarman
- Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Hannah Thomson
- Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| | - Daniel DeHelian
- Department of Medicine and the Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Lawrence F Brass
- Department of Medicine and the Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Peisong Ma
- Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA.
| |
Collapse
|
3
|
Lymperopoulos A, Suster MS, Borges JI. Cardiovascular GPCR regulation by regulator of G protein signaling proteins. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 193:145-166. [PMID: 36357075 DOI: 10.1016/bs.pmbts.2022.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
G protein-coupled receptors (GPCRs) play pivotal roles in regulation of cardiovascular homeostasis across all vertebrate species, including humans. In terms of normal cellular function, termination of GPCR signaling via the heterotrimeric G proteins is equally (if not more) important to its stimulation. The Regulator of G protein Signaling (RGS) protein superfamily are indispensable for GPCR signaling cessation at the cell membrane, and thus, for cellular control of GPCR signaling and function. Perturbations in both activation and termination of G protein signaling underlie many examples of cardiovascular dysfunction and heart disease pathogenesis. Despite the plethora of over 30 members comprising the mammalian RGS protein superfamily, each member interacts with a specific set of second messenger pathways and GPCR types/subtypes in a tissue/cell type-specific manner. An increasing number of studies over the past two decades have provided compelling evidence for the involvement of various RGS proteins in physiological regulation of cardiovascular GPCRs and, consequently, also in the pathophysiology of several cardiovascular ailments. This chapter summarizes the current understanding of the functional roles of RGS proteins as they pertain to cardiovascular, i.e., heart, blood vessel, and platelet GPCR function, with a particular focus on their implications for chronic heart failure pathophysiology and therapy.
Collapse
Affiliation(s)
- Anastasios Lymperopoulos
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL, United States.
| | - Malka S Suster
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL, United States
| | - Jordana I Borges
- Laboratory for the Study of Neurohormonal Control of the Circulation, Department of Pharmaceutical Sciences, Nova Southeastern University College of Pharmacy, Fort Lauderdale, FL, United States
| |
Collapse
|
4
|
R4 RGS proteins suppress engraftment of human hematopoietic stem/progenitor cells by modulating SDF-1/CXCR4 signaling. Blood Adv 2021; 5:4380-4392. [PMID: 34500454 PMCID: PMC8579266 DOI: 10.1182/bloodadvances.2020003307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 06/10/2021] [Indexed: 12/14/2022] Open
Abstract
Specific R4 RGS members are expressed in human HSPCs and regulated by the SDF-1/CXCR4 axis. RGS1/13/16 suppress HSPC engraftment, SDF-1 signaling, and key effectors of stem cell trafficking/maintenance.
Homing and engraftment of hematopoietic stem/progenitor cells (HSPCs) into the bone marrow (BM) microenvironment are tightly regulated by the chemokine stromal cell–derived factor-1 (SDF-1) and its G-protein–coupled receptor C-X-C motif chemokine receptor 4 (CXCR4), which on engagement with G-protein subunits, trigger downstream migratory signals. Regulators of G-protein signaling (RGS) are GTPase-accelerating protein of the Gα subunit and R4 subfamily members have been implicated in SDF-1–directed trafficking of mature hematopoietic cells, yet their expression and influence on HSPCs remain mostly unknown. Here, we demonstrated that human CD34+ cells expressed multiple R4 RGS genes, of which RGS1, RGS2, RGS13, and RGS16 were significantly upregulated by SDF-1 in a CXCR4-dependent fashion. Forced overexpression of RGS1, RGS13, or RGS16 in CD34+ cells not only inhibited SDF-1–directed migration, calcium mobilization, and phosphorylation of AKT, ERK, and STAT3 in vitro, but also markedly reduced BM engraftment in transplanted NOD/SCID mice. Genome-wide microarray analysis of RGS-overexpressing CD34+ cells detected downregulation of multiple effectors with established roles in stem cell trafficking/maintenance. Convincingly, gain-of-function of selected effectors or ex vivo priming with their ligands significantly enhanced HSPC engraftment. We also constructed an evidence-based network illustrating the overlapping mechanisms of RGS1, RGS13, and RGS16 downstream of SDF-1/CXCR4 and Gαi. This model shows that these RGS members mediate compromised kinase signaling and negative regulation of stem cell functions, complement activation, proteolysis, and cell migration. Collectively, this study uncovers an essential inhibitory role of specific R4 RGS proteins in stem cell engraftment, which could potentially be exploited to develop improved clinical HSPC transplantation protocols.
Collapse
|
5
|
Genome sequencing unveils a regulatory landscape of platelet reactivity. Nat Commun 2021; 12:3626. [PMID: 34131117 PMCID: PMC8206369 DOI: 10.1038/s41467-021-23470-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 04/13/2021] [Indexed: 12/16/2022] Open
Abstract
Platelet aggregation at the site of atherosclerotic vascular injury is the underlying pathophysiology of myocardial infarction and stroke. To build upon prior GWAS, here we report on 16 loci identified through a whole genome sequencing (WGS) approach in 3,855 NHLBI Trans-Omics for Precision Medicine (TOPMed) participants deeply phenotyped for platelet aggregation. We identify the RGS18 locus, which encodes a myeloerythroid lineage-specific regulator of G-protein signaling that co-localizes with expression quantitative trait loci (eQTL) signatures for RGS18 expression in platelets. Gene-based approaches implicate the SVEP1 gene, a known contributor of coronary artery disease risk. Sentinel variants at RGS18 and PEAR1 are associated with thrombosis risk and increased gastrointestinal bleeding risk, respectively. Our WGS findings add to previously identified GWAS loci, provide insights regarding the mechanism(s) by which genetics may influence cardiovascular disease risk, and underscore the importance of rare variant and regulatory approaches to identifying loci contributing to complex phenotypes.
Collapse
|
6
|
Chen X, Zhao X, Cooper M, Ma P. The Roles of GRKs in Hemostasis and Thrombosis. Int J Mol Sci 2020; 21:ijms21155345. [PMID: 32731360 PMCID: PMC7432802 DOI: 10.3390/ijms21155345] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 07/20/2020] [Accepted: 07/27/2020] [Indexed: 12/20/2022] Open
Abstract
Along with cancer, cardiovascular and cerebrovascular diseases remain by far the most common causes of death. Heart attacks and strokes are diseases in which platelets play a role, through activation on ruptured plaques and subsequent thrombus formation. Most platelet agonists activate platelets via G protein-coupled receptors (GPCRs), which make these receptors ideal targets for many antiplatelet drugs. However, little is known about the mechanisms that provide feedback regulation on GPCRs to limit platelet activation. Emerging evidence from our group and others strongly suggests that GPCR kinases (GRKs) are critical negative regulators during platelet activation and thrombus formation. In this review, we will summarize recent findings on the role of GRKs in platelet biology and how one specific GRK, GRK6, regulates the hemostatic response to vascular injury. Furthermore, we will discuss the potential role of GRKs in thrombotic disorders, such as thrombotic events in COVID-19 patients. Studies on the function of GRKs during platelet activation and thrombus formation have just recently begun, and a better understanding of the role of GRKs in hemostasis and thrombosis will provide a fruitful avenue for understanding the hemostatic response to injury. It may also lead to new therapeutic options for the treatment of thrombotic and cardiovascular disorders.
Collapse
Affiliation(s)
- Xi Chen
- Cardeza Foundation for Hematologic Research, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA; (X.C.); (X.Z.); (M.C.)
| | - Xuefei Zhao
- Cardeza Foundation for Hematologic Research, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA; (X.C.); (X.Z.); (M.C.)
- Cyrus Tang Hematology Center, Soochow University, Suzhou 215123, China
| | - Matthew Cooper
- Cardeza Foundation for Hematologic Research, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA; (X.C.); (X.Z.); (M.C.)
| | - Peisong Ma
- Cardeza Foundation for Hematologic Research, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA; (X.C.); (X.Z.); (M.C.)
- Correspondence: ; Tel.: +1-215-955-3966
| |
Collapse
|
7
|
RGS10 shapes the hemostatic response to injury through its differential effects on intracellular signaling by platelet agonists. Blood Adv 2019; 2:2145-2155. [PMID: 30150297 DOI: 10.1182/bloodadvances.2017008508] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/27/2018] [Indexed: 11/20/2022] Open
Abstract
Platelets express ≥2 members of the regulators of G protein signaling (RGS) family. Here, we have focused on the most abundant, RGS10, examining its impact on the hemostatic response in vivo and the mechanisms involved. We have previously shown that the hemostatic thrombi formed in response to penetrating injuries consist of a core of fully activated densely packed platelets overlaid by a shell of less-activated platelets responding to adenosine 5'-diphosphate (ADP) and thromboxane A2 (TxA2). Hemostatic thrombi formed in RGS10-/- mice were larger than in controls, with the increase due to expansion of the shell but not the core. Clot retraction was slower, and average packing density was reduced. Deleting RGS10 had agonist-specific effects on signaling. There was a leftward shift in the dose/response curve for the thrombin receptor (PAR4) agonist peptide AYPGKF but no increase in the maximum response. This contrasted with ADP and TxA2, both of which evoked considerably greater maximum responses in RGS10-/- platelets with enhanced Gq- and Gi-mediated signaling. Shape change, which is G13-mediated, was unaffected. Finally, we found that free RGS10 levels in platelets are actively regulated. In resting platelets, RGS10 was bound to 2 scaffold proteins: spinophilin and 14-3-3γ. Platelet activation caused an increase in free RGS10, as did the endothelium-derived platelet antagonist prostacyclin. Collectively, these observations show that RGS10 serves as an actively regulated node on the platelet signaling network, helping to produce smaller and more densely packed hemostatic thrombi with a greater proportion of fully activated platelets.
Collapse
|
8
|
Brass LF, Tomaiuolo M, Welsh J, Poventud-Fuentes I, Zhu L, Diamond SL, Stalker TJ. Hemostatic Thrombus Formation in Flowing Blood. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00020-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
9
|
Reiner AP, Johnson AD. Platelet Genomics. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00005-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
10
|
Sepúlveda C, Hernández B, Burgos CF, Fuentes E, Palomo I, Alarcón M. The cAMP/PKA Pathway Inhibits Beta-amyloid Peptide Release from Human Platelets. Neuroscience 2018; 397:159-171. [PMID: 30496824 DOI: 10.1016/j.neuroscience.2018.11.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/30/2018] [Accepted: 11/15/2018] [Indexed: 12/12/2022]
Abstract
The main component of Alzheimer's disease (AD) is the amyloid-beta peptide (Aβ), the brain of these patients is characterized by deposits in the parenchyma and cerebral blood vessels known as cerebral amyloid angiopathy (CAA). On the other hand, the platelets are the major source of the Aβ peptide in circulation and once secreted can activate the platelets and endothelial cells producing the secretion of several inflammatory mediators that finally end up unchaining the CAA and later AD. In the present study we demonstrate that cAMP/PKA pathway plays key roles in the regulation of calpain activation and secretion of Aβ in human platelets. We confirmed that inhibition of platelet functionality occurred when platelets were incubated with forskolin (molecule that rapidly increased cAMP levels). In this sense we found that platelets pre-incubated with forskolin (20 μM) present a complete inhibition of calpain activity and this effect is reversed using an inhibitor of protein kinase A. Consequentially, when platelets were inhibited by forskolin a reduction in the processing of the APP with the consequent decrease in the Aβ peptide secretion was observed. Therefore our study provides novel insight in relation to the mechanism of processing and release of the Aβ peptide from human platelets.
Collapse
Affiliation(s)
- C Sepúlveda
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - B Hernández
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - C F Burgos
- Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, Chile
| | - E Fuentes
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - I Palomo
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile
| | - M Alarcón
- Thrombosis Reasearch Center, Department of Clinical Biochemistry and Immunohematology, Faculty of Health Sciences, Chile; Interdisciplinary Excellence Research Program on Healthy Aging (PIEI-ES), Universidad de Talca, Talca 3460000, Chile; Centro de Estudios en Alimentos Procesados (CEAP), CONICYT-Regional, Gore Maule, R09I2001 Talca, Chile.
| |
Collapse
|
11
|
Kim K, Lee J, Ghil S. The regulators of G protein signaling
RGS
16 and
RGS
18 inhibit protease‐activated receptor 2/Gi/o signaling through distinct interactions with Gα in live cells. FEBS Lett 2018; 592:3126-3138. [DOI: 10.1002/1873-3468.13220] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/24/2018] [Accepted: 08/02/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Kiman Kim
- Department of Life Science Kyonggi University Suwon Korea
| | - Jinyong Lee
- Department of Life Science Kyonggi University Suwon Korea
| | - Sungho Ghil
- Department of Life Science Kyonggi University Suwon Korea
| |
Collapse
|
12
|
Nagy Z, Smolenski A. Cyclic nucleotide-dependent inhibitory signaling interweaves with activating pathways to determine platelet responses. Res Pract Thromb Haemost 2018; 2:558-571. [PMID: 30046761 PMCID: PMC6046581 DOI: 10.1002/rth2.12122] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/20/2018] [Indexed: 12/22/2022] Open
Abstract
Platelets are regulated by extracellular cues that impact on intracellular signaling. The endothelium releases prostacyclin and nitric oxide which stimulate the synthesis of cyclic nucleotides cAMP and cGMP leading to platelet inhibition. Other inhibitory mechanisms involve immunoreceptor tyrosine-based inhibition motif-containing receptors, intracellular receptors and receptor desensitization. Inhibitory cyclic nucleotide pathways are traditionally thought to represent a passive background system keeping platelets in a quiescent state. In contrast, cyclic nucleotides are increasingly seen to be dynamically involved in most aspects of platelet regulation. This review focuses on crosstalk between activating and cyclic nucleotide-mediated inhibitory pathways highlighting emerging new hub structures and signaling mechanisms. In particular, interactions of plasma membrane receptors like P2Y12 and GPIb/IX/V with the cyclic nucleotide system are described. Furthermore, differential regulation of the RGS18 complex, second messengers, protein kinases, and phosphatases are presented, and control over small G-proteins by guanine-nucleotide exchange factors and GTPase-activating proteins are outlined. Possible clinical implications of signaling crosstalk are discussed.
Collapse
Affiliation(s)
- Zoltan Nagy
- Institute of Cardiovascular SciencesCollege of Medical and Dental SciencesUniversity of BirminghamBirminghamUK
| | - Albert Smolenski
- UCD School of MedicineUniversity College DublinDublinIreland
- UCD Conway InstituteUniversity College DublinDublinIreland
- Irish Centre for Vascular BiologyRoyal College of Surgeons in IrelandDublinIreland
| |
Collapse
|
13
|
Makhoul S, Walter E, Pagel O, Walter U, Sickmann A, Gambaryan S, Smolenski A, Zahedi RP, Jurk K. Effects of the NO/soluble guanylate cyclase/cGMP system on the functions of human platelets. Nitric Oxide 2018; 76:71-80. [PMID: 29550521 DOI: 10.1016/j.niox.2018.03.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 03/03/2018] [Accepted: 03/12/2018] [Indexed: 02/07/2023]
Abstract
Platelets are circulating sentinels of vascular integrity and are activated, inhibited, or modulated by multiple hormones, vasoactive substances or drugs. Endothelium- or drug-derived NO strongly inhibits platelet activation via activation of the soluble guanylate cyclase (sGC) and cGMP elevation, often in synergy with cAMP-elevation by prostacyclin. However, the molecular mechanisms and diversity of cGMP effects in platelets are poorly understood and sometimes controversial. Recently, we established the quantitative human platelet proteome, the iloprost/prostacyclin/cAMP/protein kinase A (PKA)-regulated phosphoproteome, and the interactions of the ADP- and iloprost/prostacyclin-affected phosphoproteome. We also showed that the sGC stimulator riociguat is in vitro a highly specific inhibitor, via cGMP, of various functions of human platelets. Here, we review the regulatory role of the cGMP/protein kinase G (PKG) system in human platelet function, and our current approaches to establish and analyze the phosphoproteome after selective stimulation of the sGC/cGMP pathway by NO donors and riociguat. Present data indicate an extensive and diverse NO/riociguat/cGMP phosphoproteome, which has to be compared with the cAMP phosphoproteome. In particular, sGC/cGMP-regulated phosphorylation of many membrane proteins, G-proteins and their regulators, signaling molecules, protein kinases, and proteins involved in Ca2+ regulation, suggests that the sGC/cGMP system targets multiple signaling networks rather than a limited number of PKG substrate proteins.
Collapse
Affiliation(s)
- Stephanie Makhoul
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany
| | - Elena Walter
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany
| | - Oliver Pagel
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Dortmund, Germany
| | - Ulrich Walter
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Dortmund, Germany; Ruhr Universität Bochum, Medizinisches Proteom Center, Medizinische Fakultät, Bochum, Germany; Department of Chemistry, College of Physical Sciences, University of Aberdeen, Aberdeen, UK
| | - Stepan Gambaryan
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany; Russian Academy of Sciences, Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg, Russia; St. Petersburg State University, Department of Cytology and Histology, St. Petersburg, Russia
| | - Albert Smolenski
- Conway Institute of Biomolecular & Biomedical Research, Univ. College Dublin, Dublin, Ireland; Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - René P Zahedi
- Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University , Montreal, Quebec H4A 3T2, Canada; Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University , Montreal, Quebec H3T 1E2, Canada
| | - Kerstin Jurk
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany.
| |
Collapse
|
14
|
Stefanini L, Bergmeier W. Negative regulators of platelet activation and adhesion. J Thromb Haemost 2018; 16:220-230. [PMID: 29193689 PMCID: PMC5809258 DOI: 10.1111/jth.13910] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Indexed: 12/29/2022]
Abstract
Platelets are small anucleated cells that constantly patrol the cardiovascular system to preserve its integrity and prevent excessive blood loss where the vessel lining is breached. Their key challenge is to form a hemostatic plug under conditions of high shear forces. To do so, platelets have evolved a molecular machinery that enables them to sense trace amounts of signals at the site of damage and to rapidly shift from a non-adhesive to a pro-adhesive state. However, this highly efficient molecular machinery can also lead to unintended platelet activation and cause clinical complications such as thrombocytopenia and thrombosis. Thus, several checkpoints are in place to tightly control platelet activation and adhesiveness in space and time. In this review, we will discuss select negative regulators of platelet activation, which are critical to maintain patrolling platelets in a quiescent, non-adhesive state and/or to limit platelet adhesion to sites of injury.
Collapse
Affiliation(s)
- L Stefanini
- Department of Internal Medicine and Medical Specialties, Sapienza University of Rome, Rome, Italy
| | - W Bergmeier
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| |
Collapse
|
15
|
Bergmeier W, Stefanini L. Platelets at the Vascular Interface. Res Pract Thromb Haemost 2018; 2:27-33. [PMID: 29457148 PMCID: PMC5810953 DOI: 10.1002/rth2.12061] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 10/19/2017] [Indexed: 02/01/2023] Open
Abstract
In this brief review paper, we will summarize the State-of-the-Art on how platelet reactivity is regulated in circulation and at sites of vascular injury. Our review discusses recent and ongoing work, presented at this year's International Society on Thrombosis and Haemostasis (ISTH) meeting, on the role of platelets in (1) classical hemostasis at sites of mechanical injury, and (2) the maintenance of vascular integrity at sites of inflammation.
Collapse
Affiliation(s)
- Wolfgang Bergmeier
- Department of Biochemistry and BiophysicsUniversity of North Carolina at Chapel HillChapel HillNCUSA
- McAllister Heart InstituteUniversity of North Carolina at Chapel HillChapel HillNCUSA
| | - Lucia Stefanini
- Department of Internal Medicine and Medical SpecialtiesSapienza University of RomeRomeItaly
| |
Collapse
|
16
|
Druey KM. Emerging Roles of Regulators of G Protein Signaling (RGS) Proteins in the Immune System. Adv Immunol 2017; 136:315-351. [PMID: 28950950 DOI: 10.1016/bs.ai.2017.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Kirk M Druey
- Molecular Signal Transduction Section, Laboratory of Allergic Diseases, NIAID/NIH, Bethesda, MD, United States.
| |
Collapse
|
17
|
Brass LF, Diamond SL, Stalker TJ. Platelets and hemostasis: a new perspective on an old subject. Blood Adv 2016; 1:5-9. [PMID: 29296690 PMCID: PMC5744048 DOI: 10.1182/bloodadvances.2016000059] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 10/03/2016] [Indexed: 01/20/2023] Open
Abstract
Publisher's Note: This article has a companion Counterpoint by Kapur and Semple. Publisher's Note: Join in the discussion of these articles at Blood Advances Community Conversations.
Collapse
Affiliation(s)
- Lawrence F Brass
- Division of Hematology-Oncology, Department of Medicine, Perelman School of Medicine, and
| | - Scott L Diamond
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA
| | - Timothy J Stalker
- Division of Hematology-Oncology, Department of Medicine, Perelman School of Medicine, and
| |
Collapse
|
18
|
Chahal MS, Ku HT, Zhang Z, Legaspi CM, Luo A, Hopkins MM, Meier KE. Differential Expression of Ccn4 and Other Genes Between Metastatic and Non-metastatic EL4 Mouse Lymphoma Cells. Cancer Genomics Proteomics 2016; 13:437-442. [PMID: 27807066 PMCID: PMC5219917 DOI: 10.21873/cgp.20006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 08/04/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Previous work characterized variants of the EL4 murine lymphoma cell line. Some are non-metastatic, and others metastatic, in syngenic mice. In addition, metastatic EL4 cells were stably transfected with phospholipase D2 (PLD2), which further enhanced metastasis. MATERIALS AND METHODS Microarray analyses of mRNA expression was performed for non-metastatic, metastatic, and PLD2-expressing metastatic EL4 cells. RESULTS Many differences were observed between non-metastatic and metastatic cell lines. One of the most striking new findings was up-regulation of mRNA for the matricellular protein WNT1-inducible signaling pathway protein 1 (CCN4) in metastatic cells; increased protein expression was verified by immunoblotting and immunocytochemistry. Other differentially expressed genes included those for reproductive homeobox 5 (Rhox5; increased in metastatic) and cystatin 7 (Cst7; decreased in metastatic). Differences between PLD2-expressing and parental cell lines were limited but included the signaling proteins Ras guanyl releasing protein 1 (RGS18; increased with PLD2) and suppressor of cytokine signaling 2 (SOCS2; decreased with PLD2). CONCLUSION The results provide insights into signaling pathways potentially involved in conferring metastatic ability on lymphoma cells.
Collapse
Affiliation(s)
- Manpreet S Chahal
- Department of Translational Research and Cellular Therapeutics, College of Pharmacy, Washington State University, Spokane, WA, U.S.A
| | - H Teresa Ku
- Division of Development & Translational Diabetes and Endocrine Research, Beckman Research Institute of City of Hope, Duarte, CA, U.S.A
| | - Zhihong Zhang
- Department of Translational Research and Cellular Therapeutics, College of Pharmacy, Washington State University, Spokane, WA, U.S.A
| | - Christian M Legaspi
- Department of Translational Research and Cellular Therapeutics, College of Pharmacy, Washington State University, Spokane, WA, U.S.A
| | - Angela Luo
- Division of Development & Translational Diabetes and Endocrine Research, Beckman Research Institute of City of Hope, Duarte, CA, U.S.A
| | - Mandi M Hopkins
- Department of Translational Research and Cellular Therapeutics, College of Pharmacy, Washington State University, Spokane, WA, U.S.A
| | - Kathryn E Meier
- Department of Translational Research and Cellular Therapeutics, College of Pharmacy, Washington State University, Spokane, WA, U.S.A.
| |
Collapse
|
19
|
Postula M, Janicki PK, Milanowski L, Pordzik J, Eyileten C, Karlinski M, Wylezol P, Solarska M, Czlonkowka A, Kurkowska-Jastrzebka I, Sugino S, Imamura Y, Mirowska-Guzel D. Association of frequent genetic variants in platelet activation pathway genes with large-vessel ischemic stroke in Polish population. Platelets 2016; 28:66-73. [DOI: 10.1080/09537104.2016.1203404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Marek Postula
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Center for Preclinical Research and Technology CEPT, Warsaw, Poland
- Perioperative Genomics Laboratory, Penn State University, College of Medicine, Hershey, PA, USA
| | - Piotr K. Janicki
- Perioperative Genomics Laboratory, Penn State University, College of Medicine, Hershey, PA, USA
| | - Lukasz Milanowski
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Center for Preclinical Research and Technology CEPT, Warsaw, Poland
| | - Justyna Pordzik
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Center for Preclinical Research and Technology CEPT, Warsaw, Poland
| | - Ceren Eyileten
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Center for Preclinical Research and Technology CEPT, Warsaw, Poland
| | - Michal Karlinski
- 2nd Department of Neurology, Institute of Psychiatry and Neurology, Warsaw, Poland
| | - Pawel Wylezol
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Center for Preclinical Research and Technology CEPT, Warsaw, Poland
| | - Marta Solarska
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Center for Preclinical Research and Technology CEPT, Warsaw, Poland
| | - Anna Czlonkowka
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Center for Preclinical Research and Technology CEPT, Warsaw, Poland
- 2nd Department of Neurology, Institute of Psychiatry and Neurology, Warsaw, Poland
| | | | - Shigekazu Sugino
- Perioperative Genomics Laboratory, Penn State University, College of Medicine, Hershey, PA, USA
| | - Yuka Imamura
- Genome Sciences Facility, Penn State University, College of Medicine, Hershey, PA, USA
| | - Dagmara Mirowska-Guzel
- Department of Experimental and Clinical Pharmacology, Medical University of Warsaw, Center for Preclinical Research and Technology CEPT, Warsaw, Poland
| |
Collapse
|
20
|
Kehrl JH. The impact of RGS and other G-protein regulatory proteins on Gαi-mediated signaling in immunity. Biochem Pharmacol 2016; 114:40-52. [PMID: 27071343 DOI: 10.1016/j.bcp.2016.04.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 04/08/2016] [Indexed: 01/30/2023]
Abstract
Leukocyte chemoattractant receptors are members of the G-protein coupled receptor (GPCR) family. Signaling downstream of these receptors directs the localization, positioning and homeostatic trafficking of leukocytes; as well as their recruitment to, and their retention at, inflammatory sites. Ligand induced changes in the molecular conformation of chemoattractant receptors results in the engagement of heterotrimeric G-proteins, which promotes α subunits to undergo GTP/GDP exchange. This results in the functional release of βγ subunits from the heterotrimers, thereby activating downstream effector molecules, which initiate leukocyte polarization, gradient sensing, and directional migration. Pertussis toxin ADP ribosylates Gαi subunits and prevents chemoattractant receptors from triggering Gαi nucleotide exchange. The use of pertussis toxin revealed the essential importance of Gαi subunit nucleotide exchange for chemoattractant receptor signaling. More recent studies have identified a range of regulatory mechanisms that target these receptors and their associated heterotrimeric G-proteins, thereby helping to control the magnitude, kinetics, and duration of signaling. A failure in these regulatory pathways can lead to impaired receptor signaling and immunopathology. The analysis of mice with targeted deletions of Gαi isoforms as well as some of these G-protein regulatory proteins is providing insights into their roles in chemoattractant receptor signaling.
Collapse
Affiliation(s)
- John H Kehrl
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 2089, United States.
| |
Collapse
|
21
|
Wilkerson EM, Johansson MW, Hebert AS, Westphall MS, Mathur SK, Jarjour NN, Schwantes EA, Mosher DF, Coon JJ. The Peripheral Blood Eosinophil Proteome. J Proteome Res 2016; 15:1524-33. [PMID: 27005946 DOI: 10.1021/acs.jproteome.6b00006] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A system-wide understanding of biological processes requires a comprehensive knowledge of the proteins in the biological system. The eosinophil is a type of granulocytic leukocyte specified early in hematopoietic differentiation that participates in barrier defense, innate immunity, and allergic disease. The proteome of the eosinophil is largely unannotated with under 500 proteins identified. We now report a map of the nonstimulated peripheral blood eosinophil proteome assembled using two-dimensional liquid chromatography coupled with high-resolution mass spectrometry. Our analysis yielded 100,892 unique peptides mapping to 7,086 protein groups representing 6,813 genes as well as 4,802 site-specific phosphorylation events. We account for the contribution of platelets that routinely contaminate purified eosinophils and report the variability in the eosinophil proteome among five individuals and proteomic changes accompanying acute activation of eosinophils by interleukin-5. Our deep coverage and quantitative analyses fill an important gap in the existing maps of the human proteome and will enable the strategic use of proteomics to study eosinophils in human diseases.
Collapse
Affiliation(s)
| | | | - Alexander S Hebert
- Genome Center of Wisconsin, University of Wisconsin , 425 Henry Mall, Madison, Wisconsin 53706, United States
| | - Michael S Westphall
- Genome Center of Wisconsin, University of Wisconsin , 425 Henry Mall, Madison, Wisconsin 53706, United States
| | - Sameer K Mathur
- Department of Medicine, University of Wisconsin , Madison, Wisconsin 53792, United States
| | - Nizar N Jarjour
- Department of Medicine, University of Wisconsin , Madison, Wisconsin 53792, United States
| | - Elizabeth A Schwantes
- Department of Medicine, University of Wisconsin , Madison, Wisconsin 53792, United States
| | - Deane F Mosher
- Department of Medicine, University of Wisconsin , Madison, Wisconsin 53792, United States
| | - Joshua J Coon
- Genome Center of Wisconsin, University of Wisconsin , 425 Henry Mall, Madison, Wisconsin 53706, United States
| |
Collapse
|
22
|
The stop clock of platelet activation. Blood 2015; 126:2538-9. [PMID: 26635408 DOI: 10.1182/blood-2015-10-672634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|