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The Cell Cycle Checkpoint System MAST(L)-ENSA/ARPP19-PP2A is Targeted by cAMP/PKA and cGMP/PKG in Anucleate Human Platelets. Cells 2020; 9:cells9020472. [PMID: 32085646 PMCID: PMC7072724 DOI: 10.3390/cells9020472] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 02/14/2020] [Accepted: 02/14/2020] [Indexed: 12/13/2022] Open
Abstract
The cell cycle is controlled by microtubule-associated serine/threonine kinase-like (MASTL), which phosphorylates the cAMP-regulated phosphoproteins 19 (ARPP19) at S62 and 19e/α-endosulfine (ENSA) at S67and converts them into protein phosphatase 2A (PP2A) inhibitors. Based on initial proteomic data, we hypothesized that the MASTL-ENSA/ARPP19-PP2A pathway, unknown until now in platelets, is regulated and functional in these anucleate cells. We detected ENSA, ARPP19 and various PP2A subunits (including seven different PP2A B-subunits) in proteomic studies of human platelets. ENSA-S109/ARPP19–S104 were efficiently phosphorylated in platelets treated with cAMP- (iloprost) and cGMP-elevating (NO donors/riociguat) agents. ENSA-S67/ARPP19-S62 phosphorylations increased following PP2A inhibition by okadaic acid (OA) in intact and lysed platelets indicating the presence of MASTL or a related protein kinase in human platelets. These data were validated with recombinant ENSA/ARPP19 and phospho-mutants using recombinant MASTL, protein kinase A and G. Both ARPP19 phosphorylation sites S62/S104 were dephosphorylated by platelet PP2A, but only S62-phosphorylated ARPP19 acted as PP2A inhibitor. Low-dose OA treatment of platelets caused PP2A inhibition, diminished thrombin-stimulated platelet aggregation and increased phosphorylation of distinct sites of VASP, Akt, p38 and ERK1/2 MAP kinases. In summary, our data establish the entire MASTL(like)–ENSA/ARPP19–PP2A pathway in human platelets and important interactions with the PKA, MAPK and PI3K/Akt systems.
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Neilson LM, Swart ECS, Good CB, Shrank WH, Henderson R, Manolis C, Parekh N. Identifying Outcome Measures for Coronary Artery Disease Value-Based Contracting Using the Delphi Method. Cardiol Ther 2019; 8:135-143. [PMID: 30825093 PMCID: PMC6525225 DOI: 10.1007/s40119-019-0132-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Indexed: 11/25/2022] Open
Abstract
Introduction Value-based contracts (VBCs) that link drug payments to disease-related performance metrics aim to increase the value and lower the cost of medications by aligning incentives and sharing risk between payers and pharmaceutical manufacturers. This study sought to identify outcome measures that are meaningful to key stakeholders to inform VBCs for coronary artery disease (CAD) medications. Methods We administered a modified Delphi survey to gather expert opinion from a diverse panel of patients (n = 9), cardiologists (n = 4), primary care physicians (n = 5), payers (n = 2), pharmacy benefits managers (n = 3), and pharmaceutical company representatives (n = 2). A list of 16 CAD-associated clinical indicators was generated from the literature and expert consultation. Delphi participants rated the importance of each outcome on a five-point Likert scale, and selected the three most meaningful outcomes. We defined consensus as ≥ 75% agreement on the importance of an outcome (Likert scores 4 or 5 or selection of an outcome as most meaningful). Results Eleven of 13 outcomes reached consensus for importance on the Likert scale. “Preventing heart attacks” was selected as the most meaningful outcome (80%) while “preventing death” ranked second (76%). Conclusions Our study results verify the utility of a widely used clinical CAD outcome measure, myocardial infarction events, for the purpose of pharmaceutical value-based contracting. Electronic supplementary material The online version of this article (10.1007/s40119-019-0132-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lynn M Neilson
- Center for Value-Based Pharmacy Initiatives, UPMC Health Plan, Pittsburgh, PA, USA.
| | - Elizabeth C S Swart
- Center for Value-Based Pharmacy Initiatives, UPMC Health Plan, Pittsburgh, PA, USA
| | - Chester B Good
- Center for Value-Based Pharmacy Initiatives, UPMC Health Plan, Pittsburgh, PA, USA
- Division of General Internal Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - William H Shrank
- Center for Value-Based Pharmacy Initiatives, UPMC Health Plan, Pittsburgh, PA, USA
| | | | - Chronis Manolis
- Center for Value-Based Pharmacy Initiatives, UPMC Health Plan, Pittsburgh, PA, USA
- Pharmacy Division, UPMC Health Plan, Pittsburgh, PA, USA
| | - Natasha Parekh
- Center for Value-Based Pharmacy Initiatives, UPMC Health Plan, Pittsburgh, PA, USA
- Division of General Internal Medicine, University of Pittsburgh, Pittsburgh, PA, USA
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Abstract
PURPOSE OF REVIEW To investigate the current approach to aspirin challenge (drug provocation) and/or desensitization in patients with histories of hypersensitivity reactions to it, particularly in those with cardiovascular diseases. RECENT FINDINGS The literature indicates that patients with coronary artery disease (CAD), including those with an acute coronary syndrome, may safely undergo low-dose aspirin challenge and/or desensitization. Recently, flowcharts regarding challenge/desensitization procedures with aspirin in patients with CAD and histories of aspirin hypersensitivity reactions have become available. Aspirin desensitization and continuous aspirin therapy constitute an effective option in patients with nonsteroidal anti-inflammatory drug-exacerbated respiratory diseases (NERD) who have suboptimally controlled asthma or rhinosinusitis, or require multiple revision polypectomies. SUMMARY The use of aspirin has proven to reduce morbidity and mortality associated with CAD. There is a general consensus on aspirin's effectiveness in secondary prevention of CAD. Therefore, aspirin desensitization is necessary in patients with CAD and histories of hypersensitivity reactions to it. The effectiveness of aspirin desensitization and continuous therapy in patients with NERD has been shown in numerous studies. However, shared selection criteria of candidates for aspirin challenge/desensitization procedures, and simple and homogeneous protocols are necessary. Moreover, preventive safety measures are still needed in order to reduce the potential risks of these procedures.
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Makhoul S, Walter E, Pagel O, Walter U, Sickmann A, Gambaryan S, Smolenski A, Zahedi RP, Jurk K. Effects of the NO/soluble guanylate cyclase/cGMP system on the functions of human platelets. Nitric Oxide 2018; 76:71-80. [PMID: 29550521 DOI: 10.1016/j.niox.2018.03.008] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 03/03/2018] [Accepted: 03/12/2018] [Indexed: 02/07/2023]
Abstract
Platelets are circulating sentinels of vascular integrity and are activated, inhibited, or modulated by multiple hormones, vasoactive substances or drugs. Endothelium- or drug-derived NO strongly inhibits platelet activation via activation of the soluble guanylate cyclase (sGC) and cGMP elevation, often in synergy with cAMP-elevation by prostacyclin. However, the molecular mechanisms and diversity of cGMP effects in platelets are poorly understood and sometimes controversial. Recently, we established the quantitative human platelet proteome, the iloprost/prostacyclin/cAMP/protein kinase A (PKA)-regulated phosphoproteome, and the interactions of the ADP- and iloprost/prostacyclin-affected phosphoproteome. We also showed that the sGC stimulator riociguat is in vitro a highly specific inhibitor, via cGMP, of various functions of human platelets. Here, we review the regulatory role of the cGMP/protein kinase G (PKG) system in human platelet function, and our current approaches to establish and analyze the phosphoproteome after selective stimulation of the sGC/cGMP pathway by NO donors and riociguat. Present data indicate an extensive and diverse NO/riociguat/cGMP phosphoproteome, which has to be compared with the cAMP phosphoproteome. In particular, sGC/cGMP-regulated phosphorylation of many membrane proteins, G-proteins and their regulators, signaling molecules, protein kinases, and proteins involved in Ca2+ regulation, suggests that the sGC/cGMP system targets multiple signaling networks rather than a limited number of PKG substrate proteins.
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Affiliation(s)
- Stephanie Makhoul
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany
| | - Elena Walter
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany
| | - Oliver Pagel
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Dortmund, Germany
| | - Ulrich Walter
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany
| | - Albert Sickmann
- Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Dortmund, Germany; Ruhr Universität Bochum, Medizinisches Proteom Center, Medizinische Fakultät, Bochum, Germany; Department of Chemistry, College of Physical Sciences, University of Aberdeen, Aberdeen, UK
| | - Stepan Gambaryan
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany; Russian Academy of Sciences, Sechenov Institute of Evolutionary Physiology and Biochemistry, St. Petersburg, Russia; St. Petersburg State University, Department of Cytology and Histology, St. Petersburg, Russia
| | - Albert Smolenski
- Conway Institute of Biomolecular & Biomedical Research, Univ. College Dublin, Dublin, Ireland; Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - René P Zahedi
- Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University , Montreal, Quebec H4A 3T2, Canada; Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University , Montreal, Quebec H3T 1E2, Canada
| | - Kerstin Jurk
- University Medical Center Mainz, Center for Thrombosis and Hemostasis (CTH), Mainz, Germany.
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