1
|
Graff RC, Haimowitz A, Aguilan JT, Levine A, Zhang J, Yuan W, Roose-Girma M, Seshagiri S, Porcelli SA, Gamble MJ, Sidoli S, Bresnick AR, Backer JM. Platelet PI3Kβ regulates breast cancer metastasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.10.612261. [PMID: 39314490 PMCID: PMC11419023 DOI: 10.1101/2024.09.10.612261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/25/2024]
Abstract
Platelets promote tumor metastasis by several mechanisms. Platelet-tumor cell interactions induce the release of platelet cytokines, chemokines, and other factors that promote tumor cell epithelial-mesenchymal transition and invasion, granulocyte recruitment to circulating tumor cells (CTCs), and adhesion of CTCs to the endothelium, assisting in their extravasation at metastatic sites. Previous studies have shown that platelet activation in the context of thrombus formation requires the Class IA PI 3-kinase PI3Kβ. We now define a role for platelet PI3Kβ in breast cancer metastasis. Platelet PI3Kβ is essential for platelet-stimulated tumor cell invasion through Matrigel. Consistent with this finding, in vitro platelet-tumor cell binding and tumor cell-stimulated platelet activation are reduced in platelets isolated from PI3Kβ mutant mice. RNAseq and proteomic analysis of human breast epithelial cells co-cultured with platelets revealed that platelet PI3Kβ regulates the expression of EMT and metastasis-associated genes in these cells. The EMT and metastasis-associated proteins PAI-1 and IL-8 were specifically downregulated in co-cultures with PI3Kβ mutant platelets. PI3Kβ mutant platelets are impaired in their ability to stimulate YAP and Smad2 signaling in tumor cells, two pathways regulating PAI-1 expression. Finally, we show that mice expressing mutant PI3Kβ show reduced spontaneous metastasis, and platelets isolated from these mice are less able to stimulate experimental metastasis in WT mice. Taken together, these data support a role for platelet PI3Kβ in promoting breast cancer metastasis and highlight platelet PI3Kβ as a potential therapeutic target. Significance We demonstrate that platelet PI3Kβ regulates metastasis, broadening the potential use of PI3Kβ-selective inhibitors as novel agents to treat metastasis.
Collapse
|
2
|
Gołaszewska A, Misztal T, Kazberuk A, Rusak T. Study on the Mechanism of the Adrenaline-Evoked Procoagulant Response in Human Platelets. Int J Mol Sci 2024; 25:2997. [PMID: 38474244 DOI: 10.3390/ijms25052997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 02/23/2024] [Accepted: 03/03/2024] [Indexed: 03/14/2024] Open
Abstract
Adrenaline has recently been found to trigger phosphatidylserine (PS) exposure on blood platelets, resulting in amplification of the coagulation process, but the mechanism is only fragmentarily established. Using a panel of platelet receptors' antagonists and modulators of signaling pathways, we evaluated the importance of these in adrenaline-evoked PS exposure by flow cytometry. Calcium and sodium ion influx into platelet cytosol, after adrenaline treatment, was examined by fluorimetric measurements. We found a strong reduction in PS exposure after blocking of sodium and calcium ion influx via Na+/H+ exchanger (NHE) and Na+/Ca2+ exchanger (NCX), respectively. ADP receptor antagonists produced a moderate inhibitory effect. Substantial limitation of PS exposure was observed in the presence of GPIIb/IIIa antagonist, phosphoinositide-3 kinase (PI3-K) inhibitors, or prostaglandin E1, a cyclic adenosine monophosphate (cAMP)-elevating agent. We demonstrated that adrenaline may develop a procoagulant response in human platelets with the substantial role of ion exchangers (NHE and NCX), secreted ADP, GPIIb/IIIa-dependent outside-in signaling, and PI3-K. Inhibition of the above mechanisms and increasing cytosolic cAMP seem to be the most efficient procedures to control adrenaline-evoked PS exposure in human platelets.
Collapse
Affiliation(s)
- Agata Gołaszewska
- Department of General and Experimental Pathology, Medical University of Bialystok, Mickiewicza 2C, 15-230 Bialystok, Poland
| | - Tomasz Misztal
- Department of Physical Chemistry, Medical University of Bialystok, Mickiewicza 2A, 15-369 Bialystok, Poland
| | - Adam Kazberuk
- Department of Medicinal Chemistry, Medical University of Bialystok, Mickiewicza 2D, 15-959 Bialystok, Poland
| | - Tomasz Rusak
- Department of Physical Chemistry, Medical University of Bialystok, Mickiewicza 2A, 15-369 Bialystok, Poland
| |
Collapse
|
3
|
Ellis ML, Terreaux A, Alwis I, Smythe R, Perdomo J, Eckly A, Cranmer SL, Passam FH, Maclean J, Schoenwaelder SM, Ruggeri ZM, Lanza F, Taoudi S, Yuan Y, Jackson SP. GPIbα-filamin A interaction regulates megakaryocyte localization and budding during platelet biogenesis. Blood 2024; 143:342-356. [PMID: 37922495 DOI: 10.1182/blood.2023021292] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/27/2023] [Accepted: 10/24/2023] [Indexed: 11/05/2023] Open
Abstract
ABSTRACT Glycoprotein Ibα (GPIbα) is expressed on the surface of platelets and megakaryocytes (MKs) and anchored to the membrane skeleton by filamin A (flnA). Although GPIb and flnA have fundamental roles in platelet biogenesis, the nature of this interaction in megakaryocyte biology remains ill-defined. We generated a mouse model expressing either human wild-type (WT) GPIbα (hGPIbαWT) or a flnA-binding mutant (hGPIbαFW) and lacking endogenous mouse GPIbα. Mice expressing the mutant GPIbα transgene exhibited macrothrombocytopenia with preserved GPIb surface expression. Platelet clearance was normal and differentiation of MKs to proplatelets was unimpaired in hGPIbαFW mice. The most striking abnormalities in hGPIbαFW MKs were the defective formation of the demarcation membrane system (DMS) and the redistribution of flnA from the cytoplasm to the peripheral margin of MKs. These abnormalities led to disorganized internal MK membranes and the generation of enlarged megakaryocyte membrane buds. The defective flnA-GPIbα interaction also resulted in misdirected release of buds away from the vasculature into bone marrow interstitium. Restoring the linkage between flnA and GPIbα corrected the flnA redistribution within MKs and DMS ultrastructural defects as well as restored normal bud size and release into sinusoids. These studies define a new mechanism of macrothrombocytopenia resulting from dysregulated MK budding. The link between flnA and GPIbα is not essential for the MK budding process, however, it plays a major role in regulating the structure of the DMS, bud morphogenesis, and the localized release of buds into the circulation.
Collapse
Affiliation(s)
- Marc L Ellis
- Thrombosis Research Group, The Heart Institute, Newtown, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Antoine Terreaux
- Blood Cell Formation Lab, Walter and Eliza Hall Institute, Parkville, VIC, Australia
| | - Imala Alwis
- Thrombosis Research Group, The Heart Institute, Newtown, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Rhyll Smythe
- Thrombosis Research Group, The Heart Institute, Newtown, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Jose Perdomo
- Haematology Research Unit, St George and Sutherland Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Anita Eckly
- Université de Strasbourg, INSERM, French Blood Establishment (EFS) Grand Est, BPPS UMR-S 1255, FMTS, Strasbourg, France
| | - Susan L Cranmer
- Eastern Health Clinical School, Monash University, Box Hill, VIC, Australia
| | - Freda H Passam
- Thrombosis Research Group, The Heart Institute, Newtown, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Jessica Maclean
- Thrombosis Research Group, The Heart Institute, Newtown, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Simone M Schoenwaelder
- Thrombosis Research Group, The Heart Institute, Newtown, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
- School of Medical Sciences, University of Sydney, Camperdown, NSW, Australia
| | - Zaverio M Ruggeri
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA
| | - Francois Lanza
- Université de Strasbourg, INSERM, French Blood Establishment (EFS) Grand Est, BPPS UMR-S 1255, FMTS, Strasbourg, France
| | - Samir Taoudi
- Blood Cell Formation Lab, Walter and Eliza Hall Institute, Parkville, VIC, Australia
- The University of Melbourne, Parkville, VIC, Australia
| | - Yuping Yuan
- Thrombosis Research Group, The Heart Institute, Newtown, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Shaun P Jackson
- Thrombosis Research Group, The Heart Institute, Newtown, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, The Scripps Research Institute, La Jolla, CA
| |
Collapse
|
4
|
Xin H, Huang J, Song Z, Mao J, Xi X, Shi X. Structure, signal transduction, activation, and inhibition of integrin αIIbβ3. Thromb J 2023; 21:18. [PMID: 36782235 PMCID: PMC9923933 DOI: 10.1186/s12959-023-00463-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 02/06/2023] [Indexed: 02/15/2023] Open
Abstract
Integrins are heterodimeric receptors comprising α and β subunits. They are expressed on the cell surface and play key roles in cell adhesion, migration, and growth. Several types of integrins are expressed on the platelets, including αvβ3, αIIbβ3, α2β1, α5β1, and α6β1. Among these, physically αIIbβ3 is exclusively expressed on the platelet surface and their precursor cells, megakaryocytes. αIIbβ3 adopts at least three conformations: i) bent-closed, ii) extended-closed, and iii) extended-open. The transition from conformation i) to iii) occurs when αIIbβ3 is activated by stimulants. Conformation iii) possesses a high ligand affinity, which triggers integrin clustering and platelet aggregation. Platelets are indispensable for maintaining vascular system integrity and preventing bleeding. However, excessive platelet activation can result in myocardial infarction (MI) and stroke. Therefore, finding a novel strategy to stop bleeding without accelerating the risk of thrombosis is important. Regulation of αIIbβ3 activation is vital for this strategy. There are a large number of molecules that facilitate or inhibit αIIbβ3 activation. The interference of these molecules can accurately control the balance between hemostasis and thrombosis. This review describes the structure and signal transduction of αIIbβ3, summarizes the molecules that directly or indirectly affect integrin αIIbβ3 activation, and discusses some novel antiαIIbβ3 drugs. This will advance our understanding of the activation of αIIbβ3 and its essential role in platelet function and tumor development.
Collapse
Affiliation(s)
- Honglei Xin
- grid.452511.6Department of Hematology, Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210003 China
| | - Jiansong Huang
- grid.13402.340000 0004 1759 700XDepartment of Hematology, The First Affiliated Hospital, Zhejiang University School of Medicine, Zhejiang, Hangzhou 310003 China ,grid.412277.50000 0004 1760 6738Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Zhiqun Song
- grid.412676.00000 0004 1799 0784Jiangsu Province People’s Hospital and Nanjing Medical University First Affiliated Hospital, Nanjing, Jiangsu 210029 China
| | - Jianhua Mao
- grid.412277.50000 0004 1760 6738Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025 China
| | - Xiaodong Xi
- Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| | - Xiaofeng Shi
- Department of Hematology, Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, 210003, China. .,Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China.
| |
Collapse
|
5
|
Liu JST, Ding Y, Schoenwaelder S, Liu X. Improving treatment for acute ischemic stroke—Clot busting innovation in the pipeline. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 4:946367. [PMID: 35978568 PMCID: PMC9376378 DOI: 10.3389/fmedt.2022.946367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/05/2022] [Indexed: 11/13/2022] Open
Abstract
Acute ischemic stroke is a consequence of disrupted blood flow to the brain, caused by thrombosis—the pathological formation of occlusive clots within blood vessels, which can embolize distally to downstream tissues and microvasculature. The highest priority of stroke treatment is the rapid removal of occlusive clots and restoration of tissue perfusion. Intravenous thrombolysis is the pharmacological standard-of-care for the dissolution of blood clots, wherein thrombolytic drugs are administered to restore vessel patency. While the introduction of recombinant tissue-plasminogen activator (rtPA) in 1996 demonstrated the benefit of acute thrombolysis for clot removal, this was countered by severe limitations in terms of patient eligibility, lytic efficacy, rethrombosis and safety implications. Development of safer and efficacious treatment strategies to improve clot lysis has not significantly progressed over many decades, due to the challenge of maintaining the necessary efficacy-safety balance for these therapies. As such, rtPA has remained the sole approved acute therapeutic for ischemic stroke for over 25 years. Attempts to improve thrombolysis with coadministration of adjunct antithrombotics has demonstrated benefit in coronary vessels, but remain contraindicated for stroke, given all currently approved antithrombotics adversely impact hemostasis, causing bleeding. This Perspective provides a brief history of stroke drug development, as well as an overview of several groups of emerging drugs which have the potential to improve thrombolytic strategies in the future. These include inhibitors of the platelet receptor glycoprotein VI and the signaling enzyme PI3-Kinase, novel anticoagulants derived from hematophagous creatures, and proteolysis-targeting chimeras.
Collapse
Affiliation(s)
- Joanna Shu Ting Liu
- Heart Research Institute, The University of Sydney, Sydney, NSW, Australia
- Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Yiran Ding
- Faculty of Science, School of Chemistry, The University of Sydney, Sydney, NSW, Australia
| | - Simone Schoenwaelder
- Heart Research Institute, The University of Sydney, Sydney, NSW, Australia
- Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, NSW, Australia
- *Correspondence: Simone Schoenwaelder
| | - Xuyu Liu
- Heart Research Institute, The University of Sydney, Sydney, NSW, Australia
- Faculty of Science, School of Chemistry, The University of Sydney, Sydney, NSW, Australia
- Xuyu Liu
| |
Collapse
|
6
|
Phosphoinositide 3-Kinases as Potential Targets for Thrombosis Prevention. Int J Mol Sci 2022; 23:ijms23094840. [PMID: 35563228 PMCID: PMC9105564 DOI: 10.3390/ijms23094840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/23/2022] [Accepted: 04/25/2022] [Indexed: 02/01/2023] Open
Abstract
As integral parts of pathological arterial thrombi, platelets are the targets of pharmacological regimens designed to treat and prevent thrombosis. A detailed understanding of platelet biology and function is thus key to design treatments that prevent thrombotic cardiovascular disease without significant disruption of the haemostatic balance. Phosphoinositide 3-kinases (PI3Ks) are a group of lipid kinases critical to various aspects of platelet biology. There are eight PI3K isoforms, grouped into three classes. Our understanding of PI3K biology has recently progressed with the targeting of specific isoforms emerging as an attractive therapeutic strategy in various human diseases, including for thrombosis. This review will focus on the role of PI3K subtypes in platelet function and subsequent thrombus formation. Understanding the mechanisms by which platelet function is regulated by the various PI3Ks edges us closer toward targeting specific PI3K isoforms for anti-thrombotic therapy.
Collapse
|
7
|
Rovati G, Contursi A, Bruno A, Tacconelli S, Ballerini P, Patrignani P. Antiplatelet Agents Affecting GPCR Signaling Implicated in Tumor Metastasis. Cells 2022; 11:725. [PMID: 35203374 PMCID: PMC8870128 DOI: 10.3390/cells11040725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/10/2022] [Accepted: 02/16/2022] [Indexed: 11/16/2022] Open
Abstract
Metastasis requires that cancer cells survive in the circulation, colonize distant organs, and grow. Despite platelets being central contributors to hemostasis, leukocyte trafficking during inflammation, and vessel stability maintenance, there is significant evidence to support their essential role in supporting metastasis through different mechanisms. In addition to their direct interaction with cancer cells, thus forming heteroaggregates such as leukocytes, platelets release molecules that are necessary to promote a disseminating phenotype in cancer cells via the induction of an epithelial-mesenchymal-like transition. Therefore, agents that affect platelet activation can potentially restrain these prometastatic mechanisms. Although the primary adhesion of platelets to cancer cells is mainly independent of G protein-mediated signaling, soluble mediators released from platelets, such as ADP, thromboxane (TX) A2, and prostaglandin (PG) E2, act through G protein-coupled receptors (GPCRs) to cause the activation of more additional platelets and drive metastatic signaling pathways in cancer cells. In this review, we examine the contribution of the GPCRs of platelets and cancer cells in the development of cancer metastasis. Finally, the possible use of agents affecting GPCR signaling pathways as antimetastatic agents is discussed.
Collapse
Affiliation(s)
- Gianenrico Rovati
- Department of Pharmaceutical Sciences, University of Milan, 20122 Milan, Italy;
| | - Annalisa Contursi
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Neuroscience, Imaging and Clinical Science, School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy
| | - Annalisa Bruno
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Neuroscience, Imaging and Clinical Science, School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy
| | - Stefania Tacconelli
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Neuroscience, Imaging and Clinical Science, School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy
| | - Patrizia Ballerini
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Innovative Technologies in Medicine and Dentistry, “G. d’Annunzio” University, 66100 Chieti, Italy
| | - Paola Patrignani
- Laboratory of Systems Pharmacology and Translational Therapies, Center for Advanced Studies and Technology (CAST), School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy; (A.C.); (A.B.); (S.T.); (P.B.)
- Department of Neuroscience, Imaging and Clinical Science, School of Medicine, “G. d’Annunzio” University, 66100 Chieti, Italy
| |
Collapse
|
8
|
Phosphoinositide 3-kinases in platelets, thrombosis and therapeutics. Biochem J 2021; 477:4327-4342. [PMID: 33242335 DOI: 10.1042/bcj20190402] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 10/20/2020] [Accepted: 11/04/2020] [Indexed: 12/13/2022]
Abstract
Our knowledge on the expression, regulation and roles of the different phosphoinositide 3-kinases (PI3Ks) in platelet signaling and functions has greatly expanded these last twenty years. Much progress has been made in understanding the roles and regulations of class I PI3Ks which produce the lipid second messenger phosphatidylinositol 3,4,5 trisphosphate (PtdIns(3,4,5)P3). Selective pharmacological inhibitors and genetic approaches have allowed researchers to generate an impressive amount of data on the role of class I PI3Kα, β, δ and γ in platelet activation and in thrombosis. Furthermore, platelets do also express two class II PI3Ks (PI3KC2α and PI3KC2β), thought to generate PtdIns(3,4)P2 and PtdIns3P, and the sole class III PI3K (Vps34), known to synthesize PtdIns3P. Recent studies have started to reveal the importance of PI3KC2α and Vps34 in megakaryocytes and platelets, opening new perspective in our comprehension of platelet biology and thrombosis. In this review, we will summarize previous and recent advances on platelet PI3Ks isoforms. The implication of these kinases and their lipid products in fundamental platelet biological processes and thrombosis will be discussed. Finally, the relevance of developing potential antithrombotic strategies by targeting PI3Ks will be examined.
Collapse
|
9
|
PI3K/AKT/mTOR signaling in gastric cancer: Epigenetics and beyond. Life Sci 2020; 262:118513. [PMID: 33011222 DOI: 10.1016/j.lfs.2020.118513] [Citation(s) in RCA: 184] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/22/2020] [Accepted: 09/22/2020] [Indexed: 02/07/2023]
Abstract
PI3K/AKT/mTOR pathway is one of the most important signaling pathways involved in normal cellular processes. Its aberrant activation modulates autophagy, epithelial-mesenchymal transition, apoptosis, chemoresistance, and metastasis in many human cancers. Emerging evidence demonstrates that some infections as well as epigenetic regulatory mechanisms can control PI3K/AKT/mTOR signaling pathway. In this review, we focused on the role of this pathway in gastric cancer development, prognosis, and metastasis, with an emphasis on epigenetic alterations including DNA methylation, histone modifications, and post-transcriptional modulations through non-coding RNAs fluctuations as well as H. pylori and Epstein-Barr virus infections. Finally, we reviewed different molecular targets and therapeutic agents in clinical trials as a potential strategy for gastric cancer treatment through the PI3K/AKT/mTOR pathway.
Collapse
|
10
|
Thibeault PE, Ramachandran R. Biased signaling in platelet G-protein coupled receptors. Can J Physiol Pharmacol 2020; 99:255-269. [PMID: 32846106 DOI: 10.1139/cjpp-2020-0149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Platelets are small megakaryocyte-derived, anucleate, disk-like structures that play an outsized role in human health and disease. Both a decrease in the number of platelets and a variety of platelet function disorders result in petechiae or bleeding that can be life threatening. Conversely, the inappropriate activation of platelets, within diseased blood vessels, remains the leading cause of death and morbidity by affecting heart attacks and stroke. The fine balance of the platelet state in healthy individuals is controlled by a number of receptor-mediated signaling pathways that allow the platelet to rapidly respond and maintain haemostasis. G-protein coupled receptors (GPCRs) are particularly important regulators of platelet function. Here we focus on the major platelet-expressed GPCRs and discuss the roles of downstream signaling pathways (e.g., different G-protein subtypes or β-arrestin) in regulating the different phases of the platelet activation. Further, we consider the potential for selectively targeting signaling pathways that may contribute to platelet responses in disease through development of biased agonists. Such selective targeting of GPCR-mediated signaling pathways by drugs, often referred to as biased signaling, holds promise in delivering therapeutic interventions that do not present significant side effects, especially in finely balanced physiological systems such as platelet activation in haemostasis.
Collapse
Affiliation(s)
- Pierre E Thibeault
- Department of Physiology and Pharmacology, University of Western Ontario, 1151 Richmond Street, London, ON N6A5C1, Canada.,Department of Physiology and Pharmacology, University of Western Ontario, 1151 Richmond Street, London, ON N6A5C1, Canada
| | - Rithwik Ramachandran
- Department of Physiology and Pharmacology, University of Western Ontario, 1151 Richmond Street, London, ON N6A5C1, Canada.,Department of Physiology and Pharmacology, University of Western Ontario, 1151 Richmond Street, London, ON N6A5C1, Canada
| |
Collapse
|
11
|
Du B, Jin N, Zhu X, Lu D, Jin C, Li Z, Han C, Zhang Y, Lai D, Liu K, Wei R. A prospective study of serum metabolomic and lipidomic changes in myopic children and adolescents. Exp Eye Res 2020; 199:108182. [PMID: 32781198 DOI: 10.1016/j.exer.2020.108182] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 07/24/2020] [Accepted: 08/02/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND Myopia is a prevalent eye disorder, especially among children and adolescents in eastern Asian countries. Multiple measures have already been taken to prevent and treat myopia, including atropine and dopamine. However, the serum metabolic picture of myopia has not yet been studied as a whole and remains largely unclear. In this paper, a prospective and panoramic study was carried out to find out the whole serum metabolomic and lipidomic picture of myopia. METHODS With untargeted mass spectrometry (MS), myopia among 211 children and adolescents was studied. The MS features were first grouped across the samples. Then, compound annotation was carried out based on these features. Finally, the metabolite features were mapped to pathways, whose biological functions in myopia were studied and discussed. RESULTS A total of 275 metabolite features were derived from 92 aligned MS peak groups with significant fold changes, and then mapped to 33 pathways. By a comprehensive consideration of significance, fold change, importance score and appearance in different omics, 9 pathways were selected, and their biological functions were further analyzed. Among these selected pathways, 5 pathways were related with oxidative stress, a validated phenomenon during myopia development, while 5 pathways were related with dopamine receptor D2, whose molecular function in myopia treatment is not fully understood. A total of 177 metabolite features from 45 peak groups were related with the studied pathways. CONCLUSION This prospective study shed light on the whole picture of metabolomic mechanism underlying myopia and provided guidance to further elucidation of compounds and pathways in this whole picture.
Collapse
Affiliation(s)
- Bei Du
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Nan Jin
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Xiurui Zhu
- Tianjin Yunjian Medical Technology Co., Ltd., Tianjin, China; Department of Cardiothoracic Surgery, School of Medicine, Stanford University, CA, USA
| | - Daqian Lu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Chengcheng Jin
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China
| | - Zhen Li
- Tianjin Yunjian Medical Technology Co., Ltd., Tianjin, China; School of Electrical Engineering, Southeast University, Jiangsu Province, China
| | - Chunle Han
- Tianjin Yunjian Medical Technology Co., Ltd., Tianjin, China
| | - Yani Zhang
- Tianjin Yunjian Medical Technology Co., Ltd., Tianjin, China
| | - Donghai Lai
- Tianjin Yunjian Medical Technology Co., Ltd., Tianjin, China
| | - Kang Liu
- Tianjin Yunjian Medical Technology Co., Ltd., Tianjin, China.
| | - Ruihua Wei
- Tianjin Key Laboratory of Retinal Functions and Diseases, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, China.
| |
Collapse
|
12
|
Ngo ATP, Jongen M, Shatzel JJ, McCarty OJT. Platelet integrin activation surfs the calcium waves. Platelets 2020; 32:437-439. [PMID: 32441552 DOI: 10.1080/09537104.2020.1768365] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Anh T P Ngo
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA
| | - Maaike Jongen
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA
| | - Joseph J Shatzel
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA.,Departments of Hematology-Oncology, Oregon Health & Science University, Portland, OR, USA
| | - Owen J T McCarty
- Departments of Biomedical Engineering, Oregon Health & Science University, Portland, OR, USA.,Departments of Hematology-Oncology, Oregon Health & Science University, Portland, OR, USA
| |
Collapse
|
13
|
Durrant TN, Hers I. PI3K inhibitors in thrombosis and cardiovascular disease. Clin Transl Med 2020; 9:8. [PMID: 32002690 PMCID: PMC6992830 DOI: 10.1186/s40169-020-0261-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 01/13/2020] [Indexed: 12/15/2022] Open
Abstract
Phosphoinositide 3-kinases (PI3Ks) are lipid kinases that regulate important intracellular signalling and vesicle trafficking events via the generation of 3-phosphoinositides. Comprising eight core isoforms across three classes, the PI3K family displays broad expression and function throughout mammalian tissues, and the (patho)physiological roles of these enzymes in the cardiovascular system present the PI3Ks as potential therapeutic targets in settings such as thrombosis, atherosclerosis and heart failure. This review will discuss the PI3K enzymes and their roles in cardiovascular physiology and disease, with a particular focus on platelet function and thrombosis. The current progress and future potential of targeting the PI3K enzymes for therapeutic benefit in cardiovascular disease will be considered, while the challenges of developing drugs against these master cellular regulators will be discussed.
Collapse
Affiliation(s)
- Tom N Durrant
- Department of Chemistry, University of Oxford, Oxford, OX1 3QZ, UK.
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.
| |
Collapse
|
14
|
Bye AP, Gibbins JM, Mahaut-Smith MP. Ca 2+ waves coordinate purinergic receptor-evoked integrin activation and polarization. Sci Signal 2020; 13:13/615/eaav7354. [PMID: 31964805 DOI: 10.1126/scisignal.aav7354] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cells sense extracellular nucleotides through the P2Y class of purinergic G protein-coupled receptors (GPCRs), which stimulate integrin activation through signaling events, including intracellular Ca2+ mobilization. We investigated the relationship between P2Y-stimulated repetitive Ca2+ waves and fibrinogen binding to the platelet integrin αIIbβ3 (GPIIb/IIIa) through confocal fluorescence imaging of primary rat megakaryocytes. Costimulation of the receptors P2Y1 and P2Y12 generated a series of Ca2+ transients that each induced a rapid, discrete increase in fibrinogen binding. The peak and net increase of individual fibrinogen binding events correlated with the Ca2+ transient amplitude and frequency, respectively. Using BAPTA loading and selective receptor antagonists, we found that Ca2+ mobilization downstream of P2Y1 was essential for ADP-evoked fibrinogen binding, whereas P2Y12 and the kinase PI3K were also required for αIIbβ3 activation and enhanced the number of Ca2+ transients. ADP-evoked fibrinogen binding was initially uniform over the cell periphery but subsequently redistributed with a polarity that correlated with the direction of the Ca2+ waves. Polarization of αIIbβ3 may be mediated by the actin cytoskeleton, because surface-bound fibrinogen is highly immobile, and its motility was enhanced by cytoskeletal disruption. In conclusion, spatial and temporal patterns of Ca2+ increase enable fine control of αIIbβ3 activation after cellular stimulation. P2Y1-stimulated Ca2+ transients coupled to αIIbβ3 activation only in the context of P2Y12 coactivation, thereby providing an additional temporal mechanism of synergy between these Gq- and Gi-coupled GPCRs.
Collapse
Affiliation(s)
- Alexander P Bye
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading RG6 6AS, UK.
| | - Jonathan M Gibbins
- Institute for Cardiovascular and Metabolic Research, University of Reading, Reading RG6 6AS, UK
| | - Martyn P Mahaut-Smith
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, UK.
| |
Collapse
|
15
|
Function, Regulation and Biological Roles of PI3Kγ Variants. Biomolecules 2019; 9:biom9090427. [PMID: 31480354 PMCID: PMC6770443 DOI: 10.3390/biom9090427] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/14/2019] [Accepted: 08/15/2019] [Indexed: 12/19/2022] Open
Abstract
Phosphatidylinositide 3-kinase (PI3K) γ is the only class IB PI3K member playing significant roles in the G-protein-dependent regulation of cell signaling in health and disease. Originally found in the immune system, increasing evidence suggest a wide array of functions in the whole organism. PI3Kγ occur as two different heterodimeric variants: PI3Kγ (p87) and PI3Kγ (p101), which share the same p110γ catalytic subunit but differ in their associated non-catalytic subunit. Here we concentrate on specific PI3Kγ features including its regulation and biological functions. In particular, the roles of its non-catalytic subunits serving as the main regulators determining specificity of class IB PI3Kγ enzymes are highlighted.
Collapse
|
16
|
Erami Z, Heitz S, Bresnick AR, Backer JM. PI3Kβ links integrin activation and PI(3,4)P 2 production during invadopodial maturation. Mol Biol Cell 2019; 30:2367-2376. [PMID: 31318314 PMCID: PMC6741064 DOI: 10.1091/mbc.e19-03-0182] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/17/2019] [Accepted: 07/01/2019] [Indexed: 11/17/2022] Open
Abstract
The invasion of tumor cells from the primary tumor is mediated by invadopodia, actin-rich protrusive organelles that secrete matrix metalloproteases and degrade the extracellular matrix. This coupling between protrusive activity and matrix degradation facilitates tumor invasion. We previously reported that the PI3Kβ isoform of PI 3-kinase, which is regulated by both receptor tyrosine kinases and G protein-coupled receptors, is required for invasion and gelatin degradation in breast cancer cells. We have now defined the mechanism by which PI3Kβ regulates invadopodia. We find that PI3Kβ is specifically activated downstream from integrins, and is required for integrin-stimulated spreading and haptotaxis as well as integrin-stimulated invadopodia formation. Surprisingly, these integrin-stimulated and PI3Kβ-dependent responses require the production of PI(3,4)P2 by the phosphoinositide 5'-phosphatase SHIP2. Thus, integrin activation of PI3Kβ is coupled to the SHIP2-dependent production of PI(3,4)P2, which regulates the recruitment of PH domain-containing scaffolds such as lamellipodin to invadopodia. These findings provide novel mechanistic insight into the role of PI3Kβ in the regulation of invadopodia in breast cancer cells.
Collapse
Affiliation(s)
- Zahra Erami
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Samantha Heitz
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Anne R. Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
| | - Jonathan M. Backer
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461
| |
Collapse
|
17
|
Bresnick AR, Backer JM. PI3Kβ-A Versatile Transducer for GPCR, RTK, and Small GTPase Signaling. Endocrinology 2019; 160:536-555. [PMID: 30601996 PMCID: PMC6375709 DOI: 10.1210/en.2018-00843] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 12/20/2018] [Indexed: 12/17/2022]
Abstract
The phosphoinositide 3-kinase (PI3K) family includes eight distinct catalytic subunits and seven regulatory subunits. Only two PI3Ks are directly regulated downstream from G protein-coupled receptors (GPCRs): the class I enzymes PI3Kβ and PI3Kγ. Both enzymes produce phosphatidylinositol 3,4,5-trisposphate in vivo and are regulated by both heterotrimeric G proteins and small GTPases from the Ras or Rho families. However, PI3Kβ is also regulated by direct interactions with receptor tyrosine kinases (RTKs) and their tyrosine phosphorylated substrates, and similar to the class II and III PI3Ks, it binds activated Rab5. The unusually complex regulation of PI3Kβ by small and trimeric G proteins and RTKs leads to a rich landscape of signaling responses at the cellular and organismic levels. This review focuses first on the regulation of PI3Kβ activity in vitro and in cells, and then summarizes the biology of PI3Kβ signaling in distinct tissues and in human disease.
Collapse
Affiliation(s)
- Anne R Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
| | - Jonathan M Backer
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York
| |
Collapse
|
18
|
Gao Y, Yu C, Pi S, Mao L, Hu B. The role of P2Y 12 receptor in ischemic stroke of atherosclerotic origin. Cell Mol Life Sci 2019; 76:341-354. [PMID: 30302530 PMCID: PMC11105791 DOI: 10.1007/s00018-018-2937-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 09/11/2018] [Accepted: 10/05/2018] [Indexed: 12/29/2022]
Abstract
Atherosclerosis is a chronic and progressive disease of the arterial walls and a leading cause of non-cardioembolic ischemic stroke. P2Y12 is a well-recognized receptor that is expressed on platelets and is a target of thienopyridine-type antiplatelet drugs. In the last few decades, P2Y12 receptor inhibitors, such as clopidogrel, have been applied for the secondary prevention of non-cardioembolic ischemic stroke. Recent clinical studies have suggested that these P2Y12 receptor inhibitors may be more effective than other antiplatelet drugs in patients with ischemic stroke/transient ischemic attack of atherosclerotic origin. Moreover, animal studies have also shown that the P2Y12 receptor may participate in atherogenesis by promoting the proliferation and migration of vascular smooth muscle cells (VSMCs) and endothelial dysfunction, and affecting inflammatory cell activities in addition to amplifying and maintaining ADP-induced platelet activation and platelet aggregation. P2Y12 receptor inhibitors may also exert neuroprotective effects after ischemic stroke. Thus, P2Y12 receptor inhibitors may be a better choice for secondary prevention in patients with atherosclerotic ischemic stroke subtypes because of their triple functions (i.e., their anti-atherosclerotic, anti-platelet aggregation, and neuroprotective activities), and the P2Y12 receptor may also serve as a noval therapeutic target for atherosclerosis. In this review, we summarize the current knowledge on the P2Y12 receptor and its key roles in atherosclerosis and ischemic stroke of atherosclerotic origin.
Collapse
Affiliation(s)
- Ying Gao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Cheng Yu
- Department of Ultrasound, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Shulan Pi
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Ling Mao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Bo Hu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| |
Collapse
|
19
|
|
20
|
Blair TA, Moore SF, Walsh TG, Hutchinson JL, Durrant TN, Anderson KE, Poole AW, Hers I. Phosphoinositide 3-kinase p110α negatively regulates thrombopoietin-mediated platelet activation and thrombus formation. Cell Signal 2018; 50:111-120. [PMID: 29793021 DOI: 10.1016/j.cellsig.2018.05.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/17/2018] [Accepted: 05/18/2018] [Indexed: 01/21/2023]
Abstract
Phosphoinositide 3-kinase (PI3K) plays an important role in platelet function and contributes to platelet hyperreactivity induced by elevated levels of circulating peptide hormones, including thrombopoietin (TPO). Previous work established an important role for the PI3K isoform; p110β in platelet function, however the role of p110α is still largely unexplored. Here we sought to investigate the role of p110α in TPO-mediated hyperactivity by using a conditional p110α knockout (KO) murine model in conjunction with platelet functional assays. We found that TPO-mediated enhancement of collagen-related peptide (CRP-XL)-induced platelet aggregation and adenosine triphosphate (ATP) secretion were significantly increased in p110α KO platelets. Furthermore, TPO-mediated enhancement of thrombus formation by p110α KO platelets was elevated over wild-type (WT) platelets, suggesting that p110α negatively regulates TPO-mediated priming of platelet function. The enhancements were not due to increased flow through the PI3K pathway as phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) formation and phosphorylation of Akt and glycogen synthase kinase 3 (GSK3) were comparable between WT and p110α KO platelets. In contrast, extracellular responsive kinase (ERK) phosphorylation and thromboxane (TxA2) formation were significantly enhanced in p110α KO platelets, both of which were blocked by the MEK inhibitor PD184352, whereas the p38 MAPK inhibitor VX-702 and p110α inhibitor PIK-75 had no effect. Acetylsalicylic acid (ASA) blocked the enhancement of thrombus formation by TPO in both WT and p110α KO mice. Together, these results demonstrate that p110α negatively regulates TPO-mediated enhancement of platelet function by restricting ERK phosphorylation and TxA2 synthesis in a manner independent of its kinase activity.
Collapse
Affiliation(s)
- T A Blair
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - S F Moore
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - T G Walsh
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - J L Hutchinson
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - T N Durrant
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - K E Anderson
- Inositide Laboratory, Babraham Institute, Cambridge, United Kingdom
| | - A W Poole
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - I Hers
- School of Physiology, Pharmacology & Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, United Kingdom.
| |
Collapse
|
21
|
Xu H, Lu H, Zhu X, Wang W, Zhang Z, Fu H, Ma S, Luo Y, Fu J. Inhibitory effects of luteolin‑4'‑O‑β‑D‑glucopyranoside on P2Y12 and thromboxane A2 receptor‑mediated amplification of platelet activation in vitro. Int J Mol Med 2018; 42:615-624. [PMID: 29693158 DOI: 10.3892/ijmm.2018.3634] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 03/27/2018] [Indexed: 11/06/2022] Open
Abstract
Platelet activation and subsequent accumulation at sites of vascular injury are central to thrombus formation, which is considered to be a trigger of several cardiovascular diseases. Callicarpa nudiflora (C. nudiflora) Hook is a traditional Chinese medicinal herb for promoting blood circulation by removing blood stasis. In our previous study, several compounds extracted from this herb, including luteolin‑4'‑O‑β‑D‑glucopyranoside (LGP), were revealed to exert inhibitory effects on adenosine diphosphate (ADP)‑induced platelet aggregation. The aim of present study was to confirm these antiplatelet effects and elucidate the potential mechanisms. Using a platelet‑aggregation assay, it was revealed that LGP significantly inhibited platelet aggregation induced by ADP, U46619 and arachidonic acid. It was also found that LGP exhibited marked inhibitory effects on the activation of αIIbβ3 integrin, the secretion of serotonin from granules, and the synthesis of thromboxane A2. In addition, the results showed that LGP suppressed Ras homolog family member A and phosphoinositide 3‑kinase/Akt/glycogen synthase kinase 3β signal transduction. Data from a radiolabeled ligand‑binding assay indicated that LGP exhibited apparent competing effects on thromboxane receptor (TP) and P2Y12 receptors. In conclusion, the data presented here demonstrated that LGP, a natural compound from C. nudiflora Hook, inhibited the development of platelet aggregation and amplification of platelet activation. These inhibitory effects may be associated with its dual‑receptor inhibition on P2Y12 and TP receptors.
Collapse
Affiliation(s)
- Huanjun Xu
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330004, P.R. China
| | - Hong Lu
- Network and Educational Technology Center, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330004, P.R. China
| | - Xiaocui Zhu
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330004, P.R. China
| | - Wei Wang
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330004, P.R. China
| | - Zhoumiao Zhang
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330004, P.R. China
| | - Huizheng Fu
- Jiangxi Provincial Institute for Drug Control, Nanchang, Jiangxi 330029, P.R. China
| | - Shuangcheng Ma
- National Institutes for Food and Drug Control, Beijing 100050, P.R. China
| | - Yuehua Luo
- Jiangxi Provincial Institute for Drug Control, Nanchang, Jiangxi 330029, P.R. China
| | - Jianjiang Fu
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330004, P.R. China
| |
Collapse
|
22
|
Ju L, McFadyen JD, Al-Daher S, Alwis I, Chen Y, Tønnesen LL, Maiocchi S, Coulter B, Calkin AC, Felner EI, Cohen N, Yuan Y, Schoenwaelder SM, Cooper ME, Zhu C, Jackson SP. Compression force sensing regulates integrin α IIbβ 3 adhesive function on diabetic platelets. Nat Commun 2018; 9:1087. [PMID: 29540687 PMCID: PMC5852038 DOI: 10.1038/s41467-018-03430-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 02/09/2018] [Indexed: 01/25/2023] Open
Abstract
Diabetes is associated with an exaggerated platelet thrombotic response at sites of vascular injury. Biomechanical forces regulate platelet activation, although the impact of diabetes on this process remains ill-defined. Using a biomembrane force probe (BFP), we demonstrate that compressive force activates integrin αIIbβ3 on discoid diabetic platelets, increasing its association rate with immobilized fibrinogen. This compressive force-induced integrin activation is calcium and PI 3-kinase dependent, resulting in enhanced integrin affinity maturation and exaggerated shear-dependent platelet adhesion. Analysis of discoid platelet aggregation in the mesenteric circulation of mice confirmed that diabetes leads to a marked enhancement in the formation and stability of discoid platelet aggregates, via a mechanism that is not inhibited by therapeutic doses of aspirin and clopidogrel, but is eliminated by PI 3-kinase inhibition. These studies demonstrate the existence of a compression force sensing mechanism linked to αIIbβ3 adhesive function that leads to a distinct prothrombotic phenotype in diabetes.
Collapse
Affiliation(s)
- Lining Ju
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia
- Charles Perkins Centre, Level 3E Cardiovascular Division, The University of Sydney, New South Wales, 2006, Australia
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - James D McFadyen
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Saheb Al-Daher
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Imala Alwis
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia
- Charles Perkins Centre, Level 3E Cardiovascular Division, The University of Sydney, New South Wales, 2006, Australia
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Yunfeng Chen
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia
- Coulter Department of Biomedical Engineering; and Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, 92037, CA, USA
| | - Lotte L Tønnesen
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia
- Charles Perkins Centre, Level 3E Cardiovascular Division, The University of Sydney, New South Wales, 2006, Australia
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Sophie Maiocchi
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia
- Charles Perkins Centre, Level 3E Cardiovascular Division, The University of Sydney, New South Wales, 2006, Australia
| | - Brianna Coulter
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia
- Charles Perkins Centre, Level 3E Cardiovascular Division, The University of Sydney, New South Wales, 2006, Australia
| | - Anna C Calkin
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
- Lipid Metabolism and Cardiometabolic Disease Laboratory, Baker Heart and Diabetes Institute, Melbourne, Victoria, 3004, Australia
| | - Eric I Felner
- Division of Pediatric Endocrinology, Emory University School of Medicine, Atlanta, GA, 30322, USA
| | - Neale Cohen
- Clinical Diabetes, Baker Heart and Diabetes Institute, Melbourne, Victoria, 3004, Australia
| | - Yuping Yuan
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia
- Charles Perkins Centre, Level 3E Cardiovascular Division, The University of Sydney, New South Wales, 2006, Australia
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Simone M Schoenwaelder
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia
- Charles Perkins Centre, Level 3E Cardiovascular Division, The University of Sydney, New South Wales, 2006, Australia
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia
| | - Mark E Cooper
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, 3004, Victoria, Australia
| | - Cheng Zhu
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia.
- Coulter Department of Biomedical Engineering; and Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
| | - Shaun P Jackson
- Heart Research Institute, Thrombosis Group, Newtown, New South Wales, 2042, Australia.
- Charles Perkins Centre, Level 3E Cardiovascular Division, The University of Sydney, New South Wales, 2006, Australia.
- Australian Centre for Blood Diseases, Central Clinical School, Monash University, Melbourne, Victoria, 3004, Australia.
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, 92037, CA, USA.
| |
Collapse
|
23
|
Ballerini P, Dovizio M, Bruno A, Tacconelli S, Patrignani P. P2Y 12 Receptors in Tumorigenesis and Metastasis. Front Pharmacol 2018; 9:66. [PMID: 29456511 PMCID: PMC5801576 DOI: 10.3389/fphar.2018.00066] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/18/2018] [Indexed: 12/21/2022] Open
Abstract
Platelets, beyond their role in hemostasis and thrombosis, may sustain tumorigenesis and metastasis. These effects may occur via direct interaction of platelets with cancer and stromal cells and by the release of several platelet products. Platelets and tumor cells release several bioactive molecules among which a great amount of adenosine triphosphate (ATP) and adenosine diphosphate (ADP). ADP is also formed extracellularly from ATP breakdown by the ecto-nucleoside-triphosphate-diphosphohydrolases. Under ATP and ADP stimulation the purinergic P2Y1 receptor (R) initiates platelet activation followed by the ADP-P2Y12R-mediated amplification. P2Y12R stimulation amplifies also platelet response to several platelet agonists and to flow conditions, acting as a key positive feed-forward signal in intensifying platelet responses. P2Y12R represents a potential target for an anticancer therapy due to its involvement in platelet-cancer cell crosstalk. Thus, P2Y12R antagonists, including clopidogrel, ticagrelor, and prasugrel, might represent potential anti-cancer agents, in addition to their role as effective antithrombotic drugs. However, further studies, in experimental animals and patients, are required before the recommendation of the use of P2Y12R antagonists in cancer prevention and progression can be made.
Collapse
Affiliation(s)
- Patrizia Ballerini
- Department of Psychological, Health and Territorial Sciences, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy.,Center for Aging and Translational Medicine, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Melania Dovizio
- Center for Aging and Translational Medicine, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy.,Department of Neuroscience, Imaging and Clinical Science, Center for Aging and Translational Medicine, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Annalisa Bruno
- Center for Aging and Translational Medicine, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy.,Department of Neuroscience, Imaging and Clinical Science, Center for Aging and Translational Medicine, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Stefania Tacconelli
- Center for Aging and Translational Medicine, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy.,Department of Neuroscience, Imaging and Clinical Science, Center for Aging and Translational Medicine, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| | - Paola Patrignani
- Center for Aging and Translational Medicine, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy.,Department of Neuroscience, Imaging and Clinical Science, Center for Aging and Translational Medicine, Università degli Studi "G. d'Annunzio" Chieti-Pescara, Chieti, Italy
| |
Collapse
|
24
|
Fu J, Zhu X, Wang W, Lu H, Zhang Z, Liu T, Xu H, Fu H, Ma S, Luo Y. 1, 6-di-O-caffeoyl-β-D-glucopyranoside, a natural compound from Callicarpa nudiflora Hook impairs P2Y 12 and thromboxane A 2 receptor-mediated amplification of platelet activation and aggregation. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2017; 36:273-282. [PMID: 29157825 DOI: 10.1016/j.phymed.2017.10.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 08/15/2017] [Accepted: 10/15/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Platelet activation and subsequent accumulation at sites of vascular injury perform a central role in thrombus formation, which is believed to be the trigger of several cardiovascular diseases, such as atherosclerosis, myocardial infarction and strokes. In this sense, the search for agents that are capable of blocking platelets aggregation has important implications for these diseases. Callicarpa nudiflora (C. nudiflora) Hook is a traditional Chinese medicine herb for eliminating stasis to subdue swelling and hemostasis. Our previous study found several compounds extracted from this herb, including 1, 6-di-O-caffeoyl-β-D-glucopyranoside (CGP), showed inhibitory effects on adenosine diphosphate (ADP) induced platelet aggregation. PURPOSE The aim of current study is confirmation of the anti-platelet effects and elucidation of the probable mechanisms. METHODS The experiments were performed on platelet rich plasma freshly isolated from SD rat. ADP, U46619 or arachidonic acid (AA) induced platelet aggregation assay were performed to evaluate the anti-platelet properties of CGP. Activated αIIbβ3 integrin abundance, serotonin (5-HT) secretion, thromboxane A2 (TXA2) synthesis was determined to assess the effects of CGP on platelet activation. Furthermore, RhoA and PI3K/Akt/GSK3β signal transduction were analyzed by Western Blotting assay. In addition, radiolabelled ligand binding assay was involved to evaluate the ability of CGP binding to thromboxane prostanoid (TP) and P2Y12 receptors. RESULTS CGP inhibited platelet aggregation induced by ADP, U46619 and arachidonic acid (AA), significantly. Furthermore, it is also found that LGP exhibited obvious inhibitory effects on αIIbβ3 integrin activation, serotonin (5-HT) secretion from granule and thromboxane A2 (TXA2) synthesis. Next, we found that CGP suppressed RhoA and PI3K/Akt/GSK3β signal transduction. Data from radiolabelled ligand binding assay showed that CGP displayed apparent competing effects on TP and P2Y12 receptors. CONCLUSION Collectively, the data presented here demonstrated that CGP, a natural compound from Callicarpa nudiflora Hook, inhibited the development of platelet aggregation and amplification of platelet activation. These inhibitory effects may be associated with its dual-receptor inhibition on P2Y12 and TP receptors.
Collapse
Affiliation(s)
- Jianjiang Fu
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China.
| | - Xiaocui Zhu
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China
| | - Wei Wang
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China
| | - Hong Lu
- Network and Educational Technology Center, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China
| | - Zhoumiao Zhang
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China
| | - Ting Liu
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China
| | - Huanjun Xu
- Department of Pharmacology, School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, 330004, China
| | - Huizheng Fu
- Jiangxi Provincial Institute for Drug Control, Nanchang, 330029, China
| | - Shuangcheng Ma
- National Institutes for Food and Drug Control, Beijing, 100050, China
| | - Yuehua Luo
- Jiangxi Provincial Institute for Drug Control, Nanchang, 330029, China.
| |
Collapse
|
25
|
Armstrong PC, Peter K. GPIIb/IIIa inhibitors: From bench to bedside and back to bench again. Thromb Haemost 2017; 107:808-14. [DOI: 10.1160/th11-10-0727] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 01/20/2012] [Indexed: 02/06/2023]
Abstract
SummaryFrom the discovery of the platelet glycoprotein (GP) IIb/IIIa and identification of its central role in haemostasis, the integrin GPIIb/IIIa (αIIbβ3, CD41/CD61) was destined to be an anti-thrombotic target. The subsequent successful development of intravenous ligand-mimetic inhibitors occurred during a time of limited understanding of integrin physiology. Although efficient inhibitors of ligand binding, they also mimic ligand function. In the case of GPIIb/IIIa inhibitors, despite strongly inhibiting platelet aggregation, paradoxical fibrinogen binding and platelet activation can occur. The quick progression to development of small-molecule orally available inhibitors meant that this approach inherited many potential flaws, which together with a short half-life resulted in an increase in mortality and a halt to the numerous pharmaceutical development programs. Limited clinical benefits, together with the success of other anti-thrombotic drugs, in particular P2Y12 ADP receptor blockers, have also led to a restrictive use of intravenous GPIIb/ IIIa inhibitors. However, with a greater understanding of this key platelet-specific integrin, GPIIb/IIIa remains a potentially attractive target and future drug developments will be better informed by the lessons learnt from taking the current inhibitors back to the bench. This overview will review the physiology behind the inherent problems of a ligand-based integrin inhibitor design and discuss novel promising approaches for GPIIb/IIIa inhibition.
Collapse
|
26
|
Yuan Y, Alwis I, Wu MCL, Kaplan Z, Ashworth K, Bark D, Pham A, Mcfadyen J, Schoenwaelder SM, Josefsson EC, Kile BT, Jackson SP. Neutrophil macroaggregates promote widespread pulmonary thrombosis after gut ischemia. Sci Transl Med 2017; 9:eaam5861. [PMID: 28954929 DOI: 10.1126/scitranslmed.aam5861] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/02/2017] [Accepted: 08/21/2017] [Indexed: 11/02/2022]
Abstract
Gut ischemia is common in critically ill patients, promoting thrombosis and inflammation in distant organs. The mechanisms linking hemodynamic changes in the gut to remote organ thrombosis remain ill-defined. We demonstrate that gut ischemia in the mouse induces a distinct pulmonary thrombotic disorder triggered by neutrophil macroaggregates. These neutrophil aggregates lead to widespread occlusion of pulmonary arteries, veins, and the microvasculature. A similar pulmonary neutrophil-rich thrombotic response occurred in humans with the acute respiratory distress syndrome. Intravital microscopy during gut ischemia-reperfusion injury revealed that rolling neutrophils extract large membrane fragments from remnant dying platelets in multiple organs. These platelet fragments bridge adjacent neutrophils to facilitate macroaggregation. Platelet-specific deletion of cyclophilin D, a mitochondrial regulator of cell necrosis, prevented neutrophil macroaggregation and pulmonary thrombosis. Our studies demonstrate the existence of a distinct pulmonary thrombotic disorder triggered by dying platelets and neutrophil macroaggregates. Therapeutic targeting of platelet death pathways may reduce pulmonary thrombosis in critically ill patients.
Collapse
Affiliation(s)
- Yuping Yuan
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
| | - Imala Alwis
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
| | - Mike C L Wu
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
| | - Zane Kaplan
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - Katrina Ashworth
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - David Bark
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - Alan Pham
- Department of Anatomical Pathology, Alfred Hospital, Prahran, Victoria 3181, Australia
| | - James Mcfadyen
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
| | - Simone M Schoenwaelder
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia
- Heart Research Institute, Newtown, New South Wales 2042, Australia
| | - Emma C Josefsson
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Benjamin T Kile
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria 3168, Australia
| | - Shaun P Jackson
- Australian Centre for Blood Diseases, Alfred Medical and Research Education Precinct, Monash University, Melbourne, Victoria 3004, Australia.
- Heart Research Institute, Newtown, New South Wales 2042, Australia
- Charles Perkins Centre, University of Sydney, New South Wales 2006, Australia
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| |
Collapse
|
27
|
Estevez B, Du X. New Concepts and Mechanisms of Platelet Activation Signaling. Physiology (Bethesda) 2017; 32:162-177. [PMID: 28228483 DOI: 10.1152/physiol.00020.2016] [Citation(s) in RCA: 194] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Upon blood vessel injury, platelets are exposed to adhesive proteins in the vascular wall and soluble agonists, which initiate platelet activation, leading to formation of hemostatic thrombi. Pathological activation of platelets can induce occlusive thrombosis, resulting in ischemic events such as heart attack and stroke, which are leading causes of death globally. Platelet activation requires intracellular signal transduction initiated by platelet receptors for adhesion proteins and soluble agonists. Whereas many platelet activation signaling pathways have been established for many years, significant recent progress reveals much more complex and sophisticated signaling and amplification networks. With the discovery of new receptor signaling pathways and regulatory networks, some of the long-standing concepts of platelet signaling have been challenged. This review provides an overview of the new developments and concepts in platelet activation signaling.
Collapse
Affiliation(s)
- Brian Estevez
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois
| | - Xiaoping Du
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois
| |
Collapse
|
28
|
Bekő K, Koványi B, Gölöncsér F, Horváth G, Dénes Á, Környei Z, Botz B, Helyes Z, Müller CE, Sperlágh B. Contribution of platelet P2Y 12 receptors to chronic Complete Freund's adjuvant-induced inflammatory pain. J Thromb Haemost 2017; 15:1223-1235. [PMID: 28345287 DOI: 10.1111/jth.13684] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Indexed: 11/30/2022]
Abstract
Essentials The role of platelet P2Y12 receptors in the regulation of chronic inflammatory pain is unknown. Complete Freund's Adjuvant (CFA)-induced chronic inflammatory pain model was used in mice. Gene deficiency and antagonists of P2Y12 receptors attenuate hyperalgesia and local inflammation. Platelet P2Y12 receptors contribute to these effects in the chronic phase of inflammation. SUMMARY Background P2Y12 receptor antagonists are widely used in clinical practice to inhibit platelet aggregation. P2Y12 receptors are also known to regulate different forms of pain as well as local and systemic inflammation. However, it is not known whether platelet P2Y12 receptors contribute to these effects. Objectives To explore the contribution of platelet P2Y12 receptors to chronic inflammatory pain in mice. Methods Complete Freund's adjuvant (CFA)-induced chronic inflammatory pain was induced in wild-type and P2ry12 gene-deficient (P2ry12-/- ) mice, and the potent, direct-acting and reversible P2Y12 receptor antagonists PSB-0739 and cangrelor were used. Results CFA-induced mechanical hyperalgesia was significantly decreased in P2ry12-/- mice for up to 14 days, and increased neutrophil myeloperoxidase activity and tumor necrosis factor (TNF)-α and CXCL1 (KC) levels in the hind paws were also attenuated in the acute inflammation phase. At day 14, increased interleukin (IL)-1β, IL-6, TNF-α and KC levels were attenuated in P2ry12-/- mice. PSB-0739 and cangrelor reversed hyperalgesia in wild-type mice but had no effect in P2ry12-/- mice, and PSB-0739 was also effective when applied locally. The effects of both local and systemic PSB-0739 were prevented by A-803467, a selective NaV1.8 channel antagonist, suggesting the involvement of NaV1.8 channels in the antihyperalgesic effect. Platelet depletion by anti-mouse CD41 antibody decreased hyperalgesia and attenuated the proinflammatory cytokine response in wild-type but not in P2ry12-/- mice on day 14. Conclusions In conclusion, P2Y12 receptors regulate CFA-induced hyperalgesia and the local inflammatory response, and platelet P2Y12 receptors contribute to these effects in the chronic inflammation phase.
Collapse
Affiliation(s)
- K Bekő
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, Hungary
| | - B Koványi
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, Hungary
| | - F Gölöncsér
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, Hungary
| | - G Horváth
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, Hungary
| | - Á Dénes
- Laboratory of Neuroimmunology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - Z Környei
- Laboratory of Neuroimmunology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| | - B Botz
- Department of Pharmacology and Pharmacotherapy, Center for Neuroscience, and Molecular Pharmacology, Research Team, János Szentágothai Research Center, University of Pécs, University of Pécs Medical School, Pécs, Hungary
| | - Z Helyes
- Department of Pharmacology and Pharmacotherapy, Center for Neuroscience, and Molecular Pharmacology, Research Team, János Szentágothai Research Center, University of Pécs, University of Pécs Medical School, Pécs, Hungary
- MTA-PTE NAP B Chronic Pain Research Group, University of Pécs, Pécs, Hungary
| | - C E Müller
- Pharmaceutical Institute, PharmaCenter Bonn, University of Bonn, Bonn, Germany
| | - B Sperlágh
- Laboratory of Molecular Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary
| |
Collapse
|
29
|
Scaffolding Function of PI3Kgamma Emerges from Enzyme's Shadow. J Mol Biol 2017; 429:763-772. [PMID: 28179187 DOI: 10.1016/j.jmb.2017.01.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 01/12/2017] [Accepted: 01/31/2017] [Indexed: 11/20/2022]
Abstract
Traditionally, an enzyme is a protein that mediates biochemical action by binding to the substrate and by catalyzing the reaction that translates external cues into biological responses. Sequential dissemination of information from one enzyme to another facilitates signal transduction in biological systems providing for feed-forward and feed-back mechanisms. Given this viewpoint, an enzyme without its catalytic activity is generally considered to be an inert organizational protein without catalytic function and has classically been termed as pseudo-enzymes. However, pseudo-enzymes still have biological function albeit non-enzymatic like serving as a chaperone protein or an interactive platform between proteins. In this regard, majority of the studies have focused solely on the catalytic role of enzymes in biological function, overlooking the potentially critical non-enzymatic roles. Increasing evidence from recent studies implicate that the scaffolding function of enzymes could be as important in signal transduction as its catalytic activity, which is an antithesis to the definition of enzymes. Recognition of non-enzymatic functions could be critical, as these unappreciated roles may hold clues to the ineffectiveness of kinase inhibitors in pathology, which is characteristically associated with increased enzyme expression. Using an established enzyme phosphoinositide 3-kinase γ, we discuss the insights obtained from the scaffolding function and how this non-canonical role could contribute to/alter the outcomes in pathology like cancer and heart failure. Also, we hope that with this review, we provide a forum and a starting point to discuss the idea that catalytic function alone may not account for all the actions observed with increased expression of the enzyme.
Collapse
|
30
|
14-3-3ζ regulates the mitochondrial respiratory reserve linked to platelet phosphatidylserine exposure and procoagulant function. Nat Commun 2016; 7:12862. [PMID: 27670677 PMCID: PMC5052641 DOI: 10.1038/ncomms12862] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 08/10/2016] [Indexed: 12/12/2022] Open
Abstract
The 14-3-3 family of adaptor proteins regulate diverse cellular functions including cell proliferation, metabolism, adhesion and apoptosis. Platelets express numerous 14-3-3 isoforms, including 14-3-3ζ, which has previously been implicated in regulating GPIbα function. Here we show an important role for 14-3-3ζ in regulating arterial thrombosis. Interestingly, this thrombosis defect is not related to alterations in von Willebrand factor (VWF)–GPIb adhesive function or platelet activation, but instead associated with reduced platelet phosphatidylserine (PS) exposure and procoagulant function. Decreased PS exposure in 14-3-3ζ-deficient platelets is associated with more sustained levels of metabolic ATP and increased mitochondrial respiratory reserve, independent of alterations in cytosolic calcium flux. Reduced platelet PS exposure in 14-3-3ζ-deficient mice does not increase bleeding risk, but results in decreased thrombin generation and protection from pulmonary embolism, leading to prolonged survival. Our studies define an important role for 14-3-3ζ in regulating platelet bioenergetics, leading to decreased platelet PS exposure and procoagulant function. Platelets express negatively charged phosphatidylserine (PS) on their plasma membrane when propagating coagulation within a developing thrombus. Here the authors show that an adaptor protein 14-3-3 regulates mitochondrial function and PS exposure and thus platelet procoagulant activity, promising a new therapy to reduce thrombosis.
Collapse
|
31
|
Zheng Z, Pinson JA, Mountford SJ, Orive S, Schoenwaelder SM, Shackleford D, Powell A, Nelson EM, Hamilton JR, Jackson SP, Jennings IG, Thompson PE. Discovery and antiplatelet activity of a selective PI3Kβ inhibitor (MIPS-9922). Eur J Med Chem 2016; 122:339-351. [PMID: 27387421 DOI: 10.1016/j.ejmech.2016.06.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/06/2016] [Accepted: 06/08/2016] [Indexed: 01/08/2023]
Abstract
A series of amino-substituted triazines were developed and examined for PI3Kβ inhibition and anti-platelet function. Structural adaptations of a morpholine ring of the prototype pan-PI3K inhibitor ZSTK474 yielded PI3Kβ selective compounds, where the selectivity largely derives from an interaction with the non-conserved Asp862 residue, as shown by site directed mutagenesis. The most PI3Kβ selective inhibitor from the series was studied in detail through a series of in vitro and in vivo functional studies. MIPS-9922, 10 potently inhibited ADP-induced washed platelet aggregation. It also inhibited integrin αIIbβ3 activation and αIIbβ3 dependent platelet adhesion to immobilized vWF under high shear. It prevented arterial thrombus formation in the in vivo electrolytic mouse model of thrombosis without inducing prolonged bleeding or excess blood loss.
Collapse
Affiliation(s)
- Zhaohua Zheng
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia; Australian Centre for Blood Diseases, Monash University, Alfred Medical Research and Education Precinct (AMREP), 89 Commercial Road, Prahran, Victoria 3004, Australia
| | - Jo-Anne Pinson
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Simon J Mountford
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Stephanie Orive
- Australian Centre for Blood Diseases, Monash University, Alfred Medical Research and Education Precinct (AMREP), 89 Commercial Road, Prahran, Victoria 3004, Australia
| | - Simone M Schoenwaelder
- Australian Centre for Blood Diseases, Monash University, Alfred Medical Research and Education Precinct (AMREP), 89 Commercial Road, Prahran, Victoria 3004, Australia
| | - David Shackleford
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Andrew Powell
- Centre for Drug Candidate Optimisation, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Erin M Nelson
- Australian Centre for Blood Diseases, Monash University, Alfred Medical Research and Education Precinct (AMREP), 89 Commercial Road, Prahran, Victoria 3004, Australia
| | - Justin R Hamilton
- Australian Centre for Blood Diseases, Monash University, Alfred Medical Research and Education Precinct (AMREP), 89 Commercial Road, Prahran, Victoria 3004, Australia
| | - Shaun P Jackson
- Australian Centre for Blood Diseases, Monash University, Alfred Medical Research and Education Precinct (AMREP), 89 Commercial Road, Prahran, Victoria 3004, Australia
| | - Ian G Jennings
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Philip E Thompson
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia.
| |
Collapse
|
32
|
Valet C, Severin S, Chicanne G, Laurent PA, Gaits-Iacovoni F, Gratacap MP, Payrastre B. The role of class I, II and III PI 3-kinases in platelet production and activation and their implication in thrombosis. Adv Biol Regul 2015; 61:33-41. [PMID: 26714793 DOI: 10.1016/j.jbior.2015.11.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/23/2015] [Accepted: 11/25/2015] [Indexed: 01/13/2023]
Abstract
Blood platelets play a pivotal role in haemostasis and are strongly involved in arterial thrombosis, a leading cause of death worldwide. Besides their critical role in pathophysiology, platelets represent a valuable model to investigate, both in vitro and in vivo, the biological roles of different branches of the phosphoinositide metabolism, which is highly active in platelets. While the phospholipase C (PLC) pathway has a crucial role in platelet activation, it is now well established that at least one class I phosphoinositide 3-kinase (PI3K) is also mandatory for proper platelet functions. Except class II PI3Kγ, all other isoforms of PI3Ks (class I α, β, γ, δ; class II α, β and class III) are expressed in platelets. Class I PI3Ks have been extensively studied in different models over the past few decades and several isoforms are promising drug targets to treat cancer and immune diseases. In platelet activation, it has been shown that while class I PI3Kδ plays a minor role, class I PI3Kβ has an important function particularly in thrombus growth and stability under high shear stress conditions found in stenotic arteries. This class I PI3K is a potentially interesting target for antithrombotic strategies. The role of class I PI3Kα remains ill defined in platelets. Herein, we will discuss our recent data showing the potential impact of inhibitors of this kinase on thrombus formation. The role of class II PI3Kα and β as well as class III PI3K (Vps34) in platelet production and function is just emerging. Based on our data and those very recently published in the literature, we will discuss the impact of these three PI3K isoforms in platelet production and functions and in thrombosis.
Collapse
Affiliation(s)
- Colin Valet
- Inserm U1048, I2MC and Université Paul Sabatier, 31432, Toulouse Cedex 04, France
| | - Sonia Severin
- Inserm U1048, I2MC and Université Paul Sabatier, 31432, Toulouse Cedex 04, France
| | - Gaëtan Chicanne
- Inserm U1048, I2MC and Université Paul Sabatier, 31432, Toulouse Cedex 04, France
| | | | | | | | - Bernard Payrastre
- Inserm U1048, I2MC and Université Paul Sabatier, 31432, Toulouse Cedex 04, France; CHU de Toulouse, Laboratoire d'Hématologie, 31059, Toulouse Cedex 03, France.
| |
Collapse
|
33
|
Signorello MG, Leoncini G. Regulation of cAMP Intracellular Levels in Human Platelets Stimulated by 2-Arachidonoylglycerol. J Cell Biochem 2015; 117:1240-9. [PMID: 26460717 DOI: 10.1002/jcb.25408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 10/09/2015] [Indexed: 11/08/2022]
Abstract
We demonstrated that in human platelets the endocannabinoid 2-arachidonoylglycerol (2-AG) decreased dose- and time-dependently cAMP intracellular levels. No effect on cAMP decrease induced by 2-AG was observed in the presence of the adenylate cyclase inhibitor SQ22536 as well in platelets pretreated with the thromboxane A2 receptor antagonist, SQ29548 or with aspirin, inhibitor of arachidonic acid metabolism through the cyclooxygenase pathway. An almost complete recovering of cAMP level was measured in platelets pretreated with the specific inhibitor of phosphodiesterase (PDE) 3A, milrinone. In platelets pretreated with LY294002 or MK2206, inhibitors of PI3K/AKT pathway, and with U73122, inhibitor of phospholipase C pathway, only a partial prevention was shown. cAMP intracellular level depends on synthesis by adenylate cyclase and hydrolysis by PDEs. In 2-AG-stimulated platelets adenylate cyclase activity seems to be unchanged. In contrast PDEs appear to be involved. In particular PDE3A was specifically activated, as milrinone reversed cAMP reduction by 2-AG. 2-AG enhanced PDE3A activity through its phosphorylation. The PI3K/AKT pathway and PKC participate to this PDE3A phosphorylation/activation mechanism as it was greatly inhibited by platelet pretreatment with LY294002, MK2206, U73122, or the PKC specific inhibitor GF109203X. Taken together these data suggest that 2-AG potentiates its power of platelet agonist reducing cAMP intracellular level.
Collapse
Affiliation(s)
- Maria Grazia Signorello
- Department of Pharmacy, Biochemistry Lab, University of Genoa, Viale Benedetto XV 3, 16132, Genova, Italy
| | - Giuliana Leoncini
- Department of Pharmacy, Biochemistry Lab, University of Genoa, Viale Benedetto XV 3, 16132, Genova, Italy
| |
Collapse
|
34
|
Lupieri A, Smirnova N, Malet N, Gayral S, Laffargue M. PI3K signaling in arterial diseases: Non redundant functions of the PI3K isoforms. Adv Biol Regul 2015; 59:4-18. [PMID: 26238239 DOI: 10.1016/j.jbior.2015.06.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/15/2015] [Accepted: 06/15/2015] [Indexed: 06/04/2023]
Abstract
Cardiovascular diseases are the most common cause of death around the world. This includes atherosclerosis and the adverse effects of its treatment, such as restenosis and thrombotic complications. The development of these arterial pathologies requires a series of highly-intertwined interactions between immune and arterial cells, leading to specific inflammatory and fibroproliferative cellular responses. In the last few years, the study of phosphoinositide 3-kinase (PI3K) functions has become an attractive area of investigation in the field of arterial diseases, especially since inhibitors of specific PI3K isoforms have been developed. The PI3K family includes 8 members divided into classes I, II or III depending on their substrate specificity. Although some of the different isoforms are responsible for the production of the same 3-phosphoinositides, they each have specific, non-redundant functions as a result of differences in expression levels in different cell types, activation mechanisms and specific subcellular locations. This review will focus on the functions of the different PI3K isoforms that are suspected as having protective or deleterious effects in both the various immune cells and types of cell found in the arterial wall. It will also discuss our current understanding in the context of which PI3K isoform(s) should be targeted for future therapeutic interventions to prevent or treat arterial diseases.
Collapse
Affiliation(s)
- Adrien Lupieri
- INSERM, U1048, I2MC and Université Toulouse III, Toulouse, F-31300, France
| | - Natalia Smirnova
- INSERM, U1048, I2MC and Université Toulouse III, Toulouse, F-31300, France
| | - Nicole Malet
- INSERM, U1048, I2MC and Université Toulouse III, Toulouse, F-31300, France
| | - Stéphanie Gayral
- INSERM, U1048, I2MC and Université Toulouse III, Toulouse, F-31300, France
| | - Muriel Laffargue
- INSERM, U1048, I2MC and Université Toulouse III, Toulouse, F-31300, France.
| |
Collapse
|
35
|
Guidetti GF, Canobbio I, Torti M. PI3K/Akt in platelet integrin signaling and implications in thrombosis. Adv Biol Regul 2015; 59:36-52. [PMID: 26159296 DOI: 10.1016/j.jbior.2015.06.001] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 06/04/2015] [Accepted: 06/04/2015] [Indexed: 01/09/2023]
Abstract
Blood platelets are anucleated circulating cells that play a critical role in hemostasis and are also implicated in arterial thrombosis, a major cause of death worldwide. The biological function of platelets strongly relies in their reactiveness to a variety of extracellular agonists that regulate their adhesion to extracellular matrix at the site of vascular injury and their ability to form rapidly growing cell aggregates. Among the membrane receptors expressed on the cell surface, integrins are crucial for both platelet activation, adhesion and aggregation. Integrin affinity for specific ligands is regulated by intracellular signaling pathways activated in stimulated platelets, and, once engaged, integrins themselves generate and propagate signals inside the cells to reinforce and consolidate platelet response and thrombus formation. Phosphatidylinositol 3-Kinases (PI3Ks) have emerged as crucial players in platelet activation, and they are directly implicated in the regulation of integrin function. This review will discuss the contribution of PI3Ks in platelet integrin signaling, focusing on the role of specific members of class I PI3Ks and their downstream effector Akt on both integrin inside-out and outside-in signaling. The contribution of the PI3K/Akt pathways stimulated by integrin engagement and platelet activation in thrombus formation and stabilization will also be discussed in order to highlight the possibility to target these enzymes in effective anti-thrombotic therapeutic strategies.
Collapse
Affiliation(s)
- Gianni F Guidetti
- Department of Biology and Biotechnology, Laboratories of Biochemistry, University of Pavia, Pavia, Italy
| | - Ilaria Canobbio
- Department of Biology and Biotechnology, Laboratories of Biochemistry, University of Pavia, Pavia, Italy
| | - Mauro Torti
- Department of Biology and Biotechnology, Laboratories of Biochemistry, University of Pavia, Pavia, Italy.
| |
Collapse
|
36
|
Giordanetto F, Barlaam B, Berglund S, Edman K, Karlsson O, Lindberg J, Nylander S, Inghardt T. Discovery of 9-(1-phenoxyethyl)-2-morpholino-4-oxo-pyrido[1,2-a]pyrimidine-7-carboxamides as oral PI3Kβ inhibitors, useful as antiplatelet agents. Bioorg Med Chem Lett 2014; 24:3936-43. [DOI: 10.1016/j.bmcl.2014.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/01/2014] [Accepted: 07/02/2014] [Indexed: 12/15/2022]
|
37
|
Blair TA, Moore SF, Williams CM, Poole AW, Vanhaesebroeck B, Hers I. Phosphoinositide 3-kinases p110α and p110β have differential roles in insulin-like growth factor-1-mediated Akt phosphorylation and platelet priming. Arterioscler Thromb Vasc Biol 2014; 34:1681-8. [PMID: 24903091 DOI: 10.1161/atvbaha.114.303954] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Platelet hyperactivity is a contributing factor in the pathogenesis of cardiovascular disease and can be induced by elevated levels of circulating growth factors, such as insulin-like growth factor-1 (IGF-1). IGF-1 is a primer that cannot stimulate platelet activation by itself, but in combination with physiological stimuli can potentiate platelet functional responses via a phosphoinositide 3-kinase-dependent mechanism. In this study, we explored the role of the phosphoinositide 3-kinase p110α isoform in IGF-1-mediated enhancement of platelet function. APPROACH AND RESULTS Using a platelet-specific p110α knockout murine model, we demonstrate that genetic deletion, similar to pharmacological inactivation of p110α, did not affect proteinase-activated receptor 4 signaling to Akt/protein kinase B but significantly reduced IGF-1-mediated Akt phosphorylation. The p110β inhibitor TGX-221 abolished IGF-1-induced Akt phosphorylation in p110α-deficient platelets, demonstrating that both p110α and p110β contribute to IGF-1-mediated Akt phosphorylation. Genetic deletion of p110α had no effect on IGF-1-mediated increases in thrombus formation on collagen and enhancement of proteinase-activated receptor 4-mediated integrin activation and α-granule secretion. In contrast, pharmacological inhibition of p110α blocked IGF-1-mediated potentiation of integrin activation and α-granule secretion. Functional enhancement by IGF-1 in p110α knockout samples was lost after TGX-221 treatment, suggesting that p110β drives priming in the absence of the p110α isoform. CONCLUSIONS Together, these results demonstrate that both p110α and p110β are involved in Akt signaling by IGF-1, but that it is the p110α isoform that is responsible for IGF-1-mediated potentiation of platelet function.
Collapse
Affiliation(s)
- Thomas A Blair
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Samantha F Moore
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Christopher M Williams
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Alastair W Poole
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Bart Vanhaesebroeck
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Ingeborg Hers
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.).
| |
Collapse
|
38
|
Abstract
Akt is a Ser-Thr kinase with pleiotropic effects on cell survival, growth and metabolism. Recent evidence from gene-deletion studies in mice, and analysis of human platelets treated with Akt inhibitors, suggest that Akt regulates platelet activation, with potential consequences for thrombosis. Akt activation is regulated by the level of phosphoinositide 3-phosphates, and proteins that regulate concentrations of this lipid also regulate Akt activation and platelet function. Although the effectors through which Akt contributes to platelet activation are not definitively known, several candidates are discussed, including endothelial nitric oxide synthase, glycogen synthase kinase 3β, phosphodiesterase 3A and the integrin β(3) tail. Selective inhibitors of Akt isoforms or of proteins that contribute to its activation, such as individual PI3K isoforms, may make attractive targets for antithrombotic therapy. This review summarizes the current literature describing Akt activity and its regulation in platelets, including speculation regarding the future of Akt or its regulatory pathways as targets for the development of antithrombotic therapies.
Collapse
Affiliation(s)
- Donna S Woulfe
- Thomas Jefferson University, Philadelphia, PA 19107, USA Tel.: +1 215 503 5152
| |
Collapse
|
39
|
Hughan SC, Spring CM, Schoenwaelder SM, Sturgeon S, Alwis I, Yuan Y, McFadyen JD, Westein E, Goddard D, Ono A, Yamanashi Y, Nesbitt WS, Jackson SP. Dok-2 adaptor protein regulates the shear-dependent adhesive function of platelet integrin αIIbβ3 in mice. J Biol Chem 2014; 289:5051-60. [PMID: 24385425 DOI: 10.1074/jbc.m113.520148] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The Dok proteins are a family of adaptor molecules that have a well defined role in regulating cellular migration, immune responses, and tumor progression. Previous studies have demonstrated that Doks-1 to 3 are expressed in platelets and that Dok-2 is tyrosine-phosphorylated downstream of integrin αIIbβ3, raising the possibility that it participates in integrin αIIbβ3 outside-in signaling. We demonstrate that Dok-2 in platelets is primarily phosphorylated by Lyn kinase. Moreover, deficiency of Dok-2 leads to dysregulated integrin αIIbβ3-dependent cytosolic calcium flux and phosphatidylinositol(3,4)P2 accumulation. Although agonist-induced integrin αIIbβ3 affinity regulation was unaltered in Dok-2(-/-) platelets, Dok-2 deficiency was associated with a shear-dependent increase in integrin αIIbβ3 adhesive function, resulting in enhanced platelet-fibrinogen and platelet-platelet adhesive interactions under flow. This increase in adhesion was restricted to discoid platelets and involved the shear-dependent regulation of membrane tethers. Dok-2 deficiency was associated with an increased rate of platelet aggregate formation on thrombogenic surfaces, leading to accelerated thrombus growth in vivo. Overall, this study defines an important role for Dok-2 in regulating biomechanical adhesive function of discoid platelets. Moreover, they define a previously unrecognized prothrombotic mechanism that is not detected by conventional platelet function assays.
Collapse
Affiliation(s)
- Sascha C Hughan
- From the Australian Centre for Blood Diseases, Faculty of Medicine, Nursing, and Health Sciences, Monash University, Alfred Medical Research and Education Precinct, Commercial Road, Melbourne, Victoria 3004
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
|
41
|
Laurent PA, Severin S, Gratacap MP, Payrastre B. Class I PI 3-kinases signaling in platelet activation and thrombosis: PDK1/Akt/GSK3 axis and impact of PTEN and SHIP1. Adv Biol Regul 2014; 54:162-174. [PMID: 24095650 DOI: 10.1016/j.jbior.2013.09.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 09/05/2013] [Accepted: 09/06/2013] [Indexed: 06/02/2023]
Abstract
Class I phosphoinositide 3-kinases (PI3K) have been extensively studied in different models these last years and several isoforms are now promising drug targets to treat cancer and immune diseases. Blood platelets are non-nucleated cells critical for hemostasis and strongly involved in arterial thrombosis, a leading cause of death worldwide. Besides their role in hemostasis and thrombosis, platelets provide an interesting model to characterize the implication of the different isoforms of PI3K in signaling. They are specialized for regulated adhesion, particularly under high shear stress conditions found in arteries and use highly regulated signaling mechanisms to form and stabilize a thrombus. In this review we will highlight the role of class I PI3K in these processes and the pertinence of targeting them in the context of antithrombotic strategies but also the potential consequences on the bleeding risk of inhibiting the PI3K signaling in cancer therapy. The implication of upstream regulators of the most important isoforms of PI3K in platelets and their downstream effectors such as protein kinase B (PKB or Akt) and its target glycogen synthase kinase 3 (GSK3) will be discussed as well as the impact of PTEN and SHIP phosphatases as modulators of this pathway.
Collapse
Affiliation(s)
| | - Sonia Severin
- Inserm U1048, I2MC and Université Paul Sabatier, 31024 Toulouse Cedex 03, France
| | | | - Bernard Payrastre
- Inserm U1048, I2MC and Université Paul Sabatier, 31024 Toulouse Cedex 03, France; CHU de Toulouse, Laboratoire d'Hématologie, 31059 Toulouse Cedex 03, France.
| |
Collapse
|
42
|
Ryu SY, Kim S. Evaluation of CK2 inhibitor (E)-3-(2,3,4,5-tetrabromophenyl)acrylic acid (TBCA) in regulation of platelet function. Eur J Pharmacol 2013; 720:391-400. [DOI: 10.1016/j.ejphar.2013.09.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 09/10/2013] [Accepted: 09/22/2013] [Indexed: 11/25/2022]
|
43
|
Burzaco J, Conde M, Parada LA, Zugaza JL, Dehaye JP, Marino A. ATP antagonizes thrombin-induced signal transduction through 12(S)-HETE and cAMP. PLoS One 2013; 8:e67117. [PMID: 23826207 PMCID: PMC3691129 DOI: 10.1371/journal.pone.0067117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 05/15/2013] [Indexed: 11/18/2022] Open
Abstract
In this study we have investigated the role of extracellular ATP on thrombin induced-platelet aggregation (TIPA) in washed human platelets. ATP inhibited TIPA in a dose-dependent manner and this inhibition was abolished by apyrase but not by adenosine deaminase (ADA) and it was reversed by extracellular magnesium. Antagonists of P2Y1 and P2Y12 receptors had no effect on this inhibition suggesting that a P2X receptor controlled ATP-mediated TIPA inhibition. ATP also blocked inositol phosphates (IP1, IP2, IP3) generation and [Ca(2+)]i mobilization induced by thrombin. Thrombin reduced cAMP levels which were restored in the presence of ATP. SQ-22536, an adenylate cyclase (AC) inhibitor, partially reduced the inhibition exerted by ATP on TIPA. 12-lipoxygenase (12-LO) inhibitors, nordihidroguaretic acid (NDGA) and 15(S)-hydroxy-5,8,11,13-eicosatetraenoic acid (15(S)-HETE), strongly prevented ATP-mediated TIPA inhibition. Additionally, ATP inhibited the increase of 12(S)-hydroxy-5,8,10,14-eicosatetraenoic acid (12(S)-HETE) induced by thrombin. Pretreatment with both SQ-22536 and NDGA almost completely abolished ATP-mediated TIPA inhibition. Our results describe for the first time that ATP implicates both AC and 12-LO pathways in the inhibition of human platelets aggregation in response to agonists.
Collapse
Affiliation(s)
- Jaione Burzaco
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, Bilbao, Spain
| | - Manuel Conde
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, Bilbao, Spain
| | - Luis A. Parada
- Instituto de Patología Experimental, Universidad Nacional de Salta, Salta, Argentina
| | - José L. Zugaza
- Department Genetics, Physical Anthropology and Animal Physiology, Faculty of Science and Technology, University of the Basque Country, Bilbao, Spain
- Achucarro Basque Center for Neuroscience, Bizkaia Science and Technology Park, Zamudio, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Jean-Paul Dehaye
- Biochemistry and Cellular Biology Laboratory, Institute of Pharmacy C.P. 205/3, Université Libre de Bruxelles, Brussels, Belgium
| | - Aida Marino
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country, Bilbao, Spain
| |
Collapse
|
44
|
Stolla MC, Li D, Lu L, Woulfe DS. Enhanced platelet activity and thrombosis in a murine model of type I diabetes are partially insulin-like growth factor 1-dependent and phosphoinositide 3-kinase-dependent. J Thromb Haemost 2013; 11:919-29. [PMID: 23406214 DOI: 10.1111/jth.12170] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 01/29/2013] [Indexed: 01/14/2023]
Abstract
OBJECTIVES To determine whether dysregulation of platelet signaling mechanisms contributes to the increased risk of thrombosis associated with diabetes, using a type I diabetes mouse model. METHODS AND RESULTS Type I diabetes was induced in C57Bl6 mice following streptozotocin injection. Arterial thrombosis, platelet signaling and function were assessed 4 weeks later in comparison with non-diabetic control mice. Fifty-seven per cent of diabetic mice (glucose level of > 250 mg dL(-1) ) developed stable occlusive thrombi after FeCl3 injury, as compared with 5% of their non-diabetic counterparts, suggesting that diabetic mice are more sensitive to arterial injury (P ≤ 0.02). Platelets from diabetic mice were more sensitive to protease-activated receptor 4 (PAR4) agonist-induced fibrinogen binding than platelets from non-diabetic mice, and the average Akt phosphorylation induced by PAR4 agonist peptide was greater (P ≤ 0.01) in platelets from diabetic mice. Recent studies suggest that insulin-like growth factor 1 (IGF-1) potentiates Akt phosphorylation in platelets. To determine whether IGF-1 signaling contributes to the increase in PAR4 sensitivity in platelets from diabetic mice, platelet signaling and function were evaluated in the presence of inhibitors of the IGF-1 receptor. IGF-1 receptor inhibition reduced Akt phosphorylation and fibrinogen binding in platelets from diabetic mice to levels consistent with those seen in normoglycemic platelets, but had no significant effect on platelets from non-diabetic mice. CONCLUSIONS The results suggest that platelets from mice with streptozotocin-induced diabetes show enhanced platelet Akt phosphorylation and activity resulting from IGF-1-dependent mechanisms. Increases in platelet Akt activation may explain the enhanced sensitivity to thrombotic insult seen in diabetic mice.
Collapse
Affiliation(s)
- M C Stolla
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | | | | | | |
Collapse
|
45
|
Discovery of phosphoinositide 3-kinases (PI3K) p110β isoform inhibitor 4-[2-hydroxyethyl(1-naphthylmethyl)amino]-6-[(2S)-2-methylmorpholin-4-yl]-1H-pyrimidin-2-one, an effective antithrombotic agent without associated bleeding and insulin resistance. Bioorg Med Chem Lett 2012; 22:6671-6. [DOI: 10.1016/j.bmcl.2012.08.102] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 08/25/2012] [Accepted: 08/27/2012] [Indexed: 12/13/2022]
|
46
|
Giordanetto F, Wållberg A, Cassel J, Ghosal S, Kossenjans M, Yuan ZQ, Wang X, Liang L. Discovery of 4-morpholino-pyrimidin-6-one and 4-morpholino-pyrimidin-2-one-containing Phosphoinositide 3-kinase (PI3K) p110β isoform inhibitors through structure-based fragment optimisation. Bioorg Med Chem Lett 2012; 22:6665-70. [DOI: 10.1016/j.bmcl.2012.08.101] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 08/25/2012] [Accepted: 08/27/2012] [Indexed: 10/27/2022]
|
47
|
Jackson SP, Schoenwaelder SM. Antithrombotic phosphoinositide 3-kinase β inhibitors in humans: a 'shear' delight! J Thromb Haemost 2012; 10:2123-6. [PMID: 22943292 DOI: 10.1111/j.1538-7836.2012.04912.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
48
|
Nylander S, Kull B, Björkman JA, Ulvinge JC, Oakes N, Emanuelsson BM, Andersson M, Skärby T, Inghardt T, Fjellström O, Gustafsson D. Human target validation of phosphoinositide 3-kinase (PI3K)β: effects on platelets and insulin sensitivity, using AZD6482 a novel PI3Kβ inhibitor. J Thromb Haemost 2012; 10:2127-36. [PMID: 22906130 DOI: 10.1111/j.1538-7836.2012.04898.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND Based on in vitro and animal data, PI3Kβ is given an important role in platelet adhesion and aggregation but its role in insulin signaling is unclear. OBJECTIVE To strengthen the PI3Kβ target validation using the novel, short-acting inhibitor AZD6482. METHODS AND RESULTS AZD6482 is a potent, selective and ATP competitive PI3Kβ inhibitor (IC(50) 0.01 μm). A maximal anti-platelet effect was achieved at 1 μm in the in vitro and ex vivo tests both in dog and in man. In dog, in vivo AZD6482 produced a complete anti-thrombotic effect without an increased bleeding time or blood loss. AZD6482 was well tolerated in healthy volunteers during a 3-h infusion. The ex vivo anti-platelet effect and minimal bleeding time prolongation in the dog model translated well to data obtained in healthy volunteers. AZD6482 inhibited insulin-induced human adipocyte glucose uptake in vitro (IC(50) of 4.4 μm). In the euglycemic hyperinsulinemic clamp model, in rats, glucose infusion rate was not affected at 2.3 μm but reduced by about 60% at a plasma exposure of 27 μm. In man, the homeostasis model analysis (HOMA) index increased by about 10-20% at the highest plasma concentration of 5.3 μm. CONCLUSIONS This is the first human target validation for PI3Kβ inhibition as anti-platelet therapy showing a mild and generalized antiplatelet effect attenuating but not completely inhibiting multiple signaling pathways with an impressive separation towards primary hemostasis. AZD6482 at 'supratherapeutic' plasma concentrations may attenuate insulin signaling, most likely through PI3Kα inhibition.
Collapse
Affiliation(s)
- S Nylander
- Department of Bioscience, AstraZeneca R&D Mölndal, Mölndal, Sweden.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Flierl U, Fraccarollo D, Lausenmeyer E, Rosenstock T, Schulz C, Massberg S, Bauersachs J, Schäfer A. Fractalkine activates a signal transduction pathway similar to P2Y12 and is associated with impaired clopidogrel responsiveness. Arterioscler Thromb Vasc Biol 2012; 32:1832-40. [PMID: 22652599 DOI: 10.1161/atvbaha.112.250720] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Fractalkine (FKN) activates a G(αi) protein-coupled signaling pathway similar to the one activated by ADP via P2Y(12), which is the drug target of clopidogrel. FKN levels are increased under several disease conditions associated with impaired clopidogrel responsiveness. METHODS AND RESULTS Blood samples were obtained from healthy volunteers and from 40 patients under chronic clopidogrel treatment. FKN reduced prostaglandin E1-induced vasodilator-stimulated phosphoprotein phosphorylation by ≈ 25% (P<0.01) at least partially mimicking the effect of ADP via P2Y(12). In vitro, FKN increased platelet reactivity index in clopidogrel-treated patients indicating potential activation of downstream targets of P2Y(12). When stratifying patients by their FKN levels, patients within the highest quartile of FKN (2042 ± 25 pg/mL) had the weakest response to clopidogrel (platelet reactivity index, 68 ± 4%), and patients within the lowest quartile (479 ± 50 pg/mL) had the strongest response (platelet reactivity index, 48 ± 7%; P=0.0106). FKN by itself induced phosphoinositide 3-kinase activation leading to Akt phosphorylation at Ser(473) (P<0.01 versus basal). CONCLUSIONS In addition to desensitizing platelets to prostaglandin E1 via G(αi), FKN induces phosphoinositide 3-kinase-dependent Akt phosphorylation via a G(βγ) protein similar to ADP signaling through P2Y(12). FKN increased the platelet ADP response in clopidogrel-treated patients. Once released from an atherosclerotic lesion, this mechanism could contribute locally to impaired clopidogrel responsiveness at the vulnerable plaque.
Collapse
Affiliation(s)
- Ulrike Flierl
- Klinik für Kardiologie und Angiologie, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Appelboom G, Piazza M, Bruce SS, Zoller SD, Hwang B, Monahan A, Hwang RY, Kisslev S, Mayer S, Meyers PM, Badjatia N, Connolly ES. Variation in a locus linked to platelet aggregation phenotype predicts intraparenchymal hemorrhagic volume. Neurol Res 2012; 34:232-7. [PMID: 22449554 DOI: 10.1179/1743132811y.0000000080] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE Alteration in platelet aggregation has been shown to promote bleeding and affect outcome after intracerebral hemorrhage (ICH).We investigated the influence of genetic variants of platelet aggregation, and their effects on admission ICH volume and clinical outcome. METHODS Our prospective study analyzed selected candidate single-nucleotide polymorphisms (SNPs) previously associated with platelet aggregation phenotype in previous genome-wide association studies, with regards to outcome and ICH volume. Patients were assessed at the Columbia University Medical Center Neuro-Intensive Care Unit. Exclusion criteria included age <18 years, ICH following trauma, hemorrhagic transformation, or tumor, no consent for genetic analysis, or incomplete data. Radiological variables (location and volume of acute ICH, presence of intraventricular extension, midline shift, and hydrocephalus) and clinical variables (mortality and modified Rankin score at discharge) were prospectively recorded. RESULTS One hundred and twenty-two patients with spontaneous ICH between February 2009 and May 2011 diagnosed via clinical assessment and admission computed tomography scan were included. The median admission Glasgow coma scale score (GCS) was 11·5. Univariate predictors of mortality at discharge included systolic blood pressure, presence of intraventricular hemorrhage, anticoagulant use, and GCS, the only independent predictor of discharge mortality (P<0·001). Age, intraventricular hemorrhage, and GCS were associated with poor functional outcome; age (P = 0·001) and GCS (P<0·001) were significant in the multivariate model. Admission GCS (P<0·01), antiplatelet use, and rs342286 (PIK3CG; P = 0·04; R(2) = 0·247) had univariate associations with hematoma volume. DISCUSSION We identified SNP rs342286 as an independent predictor of admission hematoma volume. Our findings suggest that PIK3CG function, which is previously linked to this SNP and affects platelet aggregation, impacts the severity of the intraparenchymal bleed.
Collapse
Affiliation(s)
- Geoffrey Appelboom
- Cerebrovascular Laboratory Columbia University, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|