1
|
Goudswaard LJ, Smith ML, Hughes DA, Taylor R, Lean M, Sattar N, Welsh P, McConnachie A, Blazeby JM, Rogers CA, Suhre K, Zaghlool SB, Hers I, Timpson NJ, Corbin LJ. Using trials of caloric restriction and bariatric surgery to explore the effects of body mass index on the circulating proteome. Sci Rep 2023; 13:21077. [PMID: 38030643 PMCID: PMC10686974 DOI: 10.1038/s41598-023-47030-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 11/08/2023] [Indexed: 12/01/2023] Open
Abstract
Thousands of proteins circulate in the bloodstream; identifying those which associate with weight and intervention-induced weight loss may help explain mechanisms of diseases associated with adiposity. We aimed to identify consistent protein signatures of weight loss across independent studies capturing changes in body mass index (BMI). We analysed proteomic data from studies implementing caloric restriction (Diabetes Remission Clinical trial) and bariatric surgery (By-Band-Sleeve), using SomaLogic and Olink Explore1536 technologies, respectively. Linear mixed models were used to estimate the effect of the interventions on circulating proteins. Twenty-three proteins were altered in a consistent direction after both bariatric surgery and caloric restriction, suggesting that these proteins are modulated by weight change, independent of intervention type. We also integrated Mendelian randomisation (MR) estimates of the effect of BMI on proteins measured by SomaLogic from a UK blood donor cohort as a third line of causal evidence. These MR estimates provided further corroborative evidence for a role of BMI in regulating the levels of six proteins including alcohol dehydrogenase-4, nogo receptor and interleukin-1 receptor antagonist protein. These results indicate the importance of triangulation in interrogating causal relationships; further study into the role of proteins modulated by weight in disease is now warranted.
Collapse
Affiliation(s)
- Lucy J Goudswaard
- Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK.
- MRC Integrative Epidemiology Unit, Bristol, UK.
- Physiology, Pharmacology & Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.
| | - Madeleine L Smith
- Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK
- MRC Integrative Epidemiology Unit, Bristol, UK
| | - David A Hughes
- Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK
- MRC Integrative Epidemiology Unit, Bristol, UK
| | - Roy Taylor
- Newcastle Magnetic Resonance Centre, Translational and Clinical Research Institute, Newcastle University, Newcastle Upon Tyne, NE4 5PL, UK
| | - Michael Lean
- Human Nutrition, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary & Life Sciences, University of Glasgow, Glasgow, G31 2ER, UK
| | - Naveed Sattar
- School of Cardiovascular and Medical Science, University of Glasgow, Glasgow, G12 8TA, UK
| | - Paul Welsh
- School of Cardiovascular and Medical Science, University of Glasgow, Glasgow, G12 8TA, UK
| | - Alex McConnachie
- Robertson Centre for Biostatistics, School of Health and Wellbeing, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Jane M Blazeby
- Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK
| | - Chris A Rogers
- Bristol Medical School, Bristol Trials Centre, University of Bristol, Bristol, BS8 1NU, UK
| | - Karsten Suhre
- Department of Biophysics and Physiology, Weill Cornell Medicine - Qatar, Doha, Qatar
| | - Shaza B Zaghlool
- Department of Biophysics and Physiology, Weill Cornell Medicine - Qatar, Doha, Qatar
| | - Ingeborg Hers
- Physiology, Pharmacology & Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Nicholas J Timpson
- Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK
- MRC Integrative Epidemiology Unit, Bristol, UK
| | - Laura J Corbin
- Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK
- MRC Integrative Epidemiology Unit, Bristol, UK
| |
Collapse
|
2
|
Constantinescu AE, Bull CJ, Goudswaard LJ, Zheng J, Elsworth B, Timpson NJ, Moore SF, Hers I, Vincent EE. A phenome-wide approach to identify causal risk factors for deep vein thrombosis. BMC Med Genomics 2023; 16:284. [PMID: 37951941 PMCID: PMC10640748 DOI: 10.1186/s12920-023-01710-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 10/20/2023] [Indexed: 11/14/2023] Open
Abstract
Deep vein thrombosis (DVT) is the formation of a blood clot in a deep vein. DVT can lead to a venous thromboembolism (VTE), the combined term for DVT and pulmonary embolism, a leading cause of death and disability worldwide. Despite the prevalence and associated morbidity of DVT, the underlying causes are not well understood. Our aim was to leverage publicly available genetic summary association statistics to identify causal risk factors for DVT. We conducted a Mendelian randomization phenome-wide association study (MR-PheWAS) using genetic summary association statistics for 973 exposures and DVT (6,767 cases and 330,392 controls in UK Biobank). There was evidence for a causal effect of 57 exposures on DVT risk, including previously reported risk factors (e.g. body mass index-BMI and height) and novel risk factors (e.g. hyperthyroidism and varicose veins). As the majority of identified risk factors were adiposity-related, we explored the molecular link with DVT by undertaking a two-sample MR mediation analysis of BMI-associated circulating proteins on DVT risk. Our results indicate that circulating neurogenic locus notch homolog protein 1 (NOTCH1), inhibin beta C chain (INHBC) and plasminogen activator inhibitor 1 (PAI-1) influence DVT risk, with PAI-1 mediating the BMI-DVT relationship. Using a phenome-wide approach, we provide putative causal evidence that hyperthyroidism, varicose veins and BMI enhance the risk of DVT. Furthermore, the circulating protein PAI-1 has a causal role in DVT aetiology and is involved in mediating the BMI-DVT relationship.
Collapse
Affiliation(s)
- Andrei-Emil Constantinescu
- MRC Integrative Epidemiology Unit at the University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK.
- Bristol Medical School, Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK.
- School of Translational Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK.
| | - Caroline J Bull
- MRC Integrative Epidemiology Unit at the University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Bristol Medical School, Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- School of Translational Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Health Data Research UK. Registered Office, 215 Euston Road, London, NW1 2BE, UK
| | - Lucy J Goudswaard
- MRC Integrative Epidemiology Unit at the University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Bristol Medical School, Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Jie Zheng
- MRC Integrative Epidemiology Unit at the University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Bristol Medical School, Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai National Clinical Research Center for Metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR China, Shanghai National Center for Translational Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Benjamin Elsworth
- Our Future Health Ltd. Registered office: 2 New Bailey, 6 Stanley Street, Manchester, M3 5GS, UK
| | - Nicholas J Timpson
- MRC Integrative Epidemiology Unit at the University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Bristol Medical School, Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
| | - Samantha F Moore
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- UKRI Medical Research Council, Swindon, UK
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Emma E Vincent
- MRC Integrative Epidemiology Unit at the University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- Bristol Medical School, Population Health Sciences, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
- School of Translational Health Sciences, Bristol Medical School, University of Bristol, Oakfield House, Oakfield Grove, Bristol, UK
| |
Collapse
|
3
|
Zhao X, Alibhai D, Walsh TG, Tarassova N, Englert M, Birol SZ, Li Y, Williams CM, Neal CR, Burkard P, Cross SJ, Aitken EW, Waller AK, Beltrán JB, Gunning PW, Hardeman EC, Agbani EO, Nieswandt B, Hers I, Ghevaert C, Poole AW. Highly efficient platelet generation in lung vasculature reproduced by microfluidics. Nat Commun 2023; 14:4026. [PMID: 37419900 PMCID: PMC10329040 DOI: 10.1038/s41467-023-39598-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 06/20/2023] [Indexed: 07/09/2023] Open
Abstract
Platelets, small hemostatic blood cells, are derived from megakaryocytes. Both bone marrow and lung are principal sites of thrombopoiesis although underlying mechanisms remain unclear. Outside the body, however, our ability to generate large number of functional platelets is poor. Here we show that perfusion of megakaryocytes ex vivo through the mouse lung vasculature generates substantial platelet numbers, up to 3000 per megakaryocyte. Despite their large size, megakaryocytes are able repeatedly to passage through the lung vasculature, leading to enucleation and subsequent platelet generation intravascularly. Using ex vivo lung and an in vitro microfluidic chamber we determine how oxygenation, ventilation, healthy pulmonary endothelium and the microvascular structure support thrombopoiesis. We also show a critical role for the actin regulator Tropomyosin 4 in the final steps of platelet formation in lung vasculature. This work reveals the mechanisms of thrombopoiesis in lung vasculature and informs approaches to large-scale generation of platelets.
Collapse
Affiliation(s)
- Xiaojuan Zhao
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK.
| | - Dominic Alibhai
- Wolfson BioimagingFacility, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Tony G Walsh
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Nathalie Tarassova
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Maximilian Englert
- University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, D-97080, Germany
| | - Semra Z Birol
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Yong Li
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Christopher M Williams
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Chris R Neal
- Wolfson BioimagingFacility, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Philipp Burkard
- University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, D-97080, Germany
| | - Stephen J Cross
- Wolfson BioimagingFacility, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Elizabeth W Aitken
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Amie K Waller
- University of Cambridge / NHS Blood and Transplant, Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0AW, UK
| | - José Ballester Beltrán
- University of Cambridge / NHS Blood and Transplant, Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0AW, UK
| | - Peter W Gunning
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Edna C Hardeman
- School of Medical Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Ejaife O Agbani
- Cumming School of Medicine, University of Calgary, Calgary, AB, T2N 1N4, Canada
| | - Bernhard Nieswandt
- University Hospital and Rudolf Virchow Center, University of Würzburg, Würzburg, D-97080, Germany
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Cedric Ghevaert
- University of Cambridge / NHS Blood and Transplant, Wellcome-MRC Cambridge Stem Cell Institute, Jeffrey Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0AW, UK
| | - Alastair W Poole
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK.
| |
Collapse
|
4
|
Trory JS, Munkacsi A, Śledź KM, Vautrinot J, Goudswaard LJ, Jackson ML, Heesom KJ, Moore SF, Poole AW, Nabet B, Aggarwal VK, Hers I. Chemical degradation of BTK/TEC as a novel approach to inhibit platelet function. Blood Adv 2023; 7:1692-1696. [PMID: 36342848 PMCID: PMC10182296 DOI: 10.1182/bloodadvances.2022008466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Affiliation(s)
- Justin S. Trory
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Attila Munkacsi
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Kamila M. Śledź
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Jordan Vautrinot
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Lucy J. Goudswaard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
- Bristol Medical School, Population Health Sciences, University of Bristol, Oakfield House, Bristol, United Kingdom
| | - Molly L. Jackson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Kate J. Heesom
- Faculty of Life Sciences, Proteomics Facility, University of Bristol, University Walk, Biomedical Sciences Building, Bristol, United Kingdom
| | - Samantha F. Moore
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Alastair W. Poole
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Behnam Nabet
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA
| | - Varinder K. Aggarwal
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol, United Kingdom
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| |
Collapse
|
5
|
Agbani EO, Hers I, Poole AW. Platelet procoagulant membrane dynamics: a key distinction between thrombosis and hemostasis? Blood Adv 2023; 7:1615-1619. [PMID: 36574232 PMCID: PMC10173732 DOI: 10.1182/bloodadvances.2022008122] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/28/2022] Open
Affiliation(s)
- Ejaife O. Agbani
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Alastair W. Poole
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
6
|
Goudswaard LJ, Williams CM, Khalil J, Burley KL, Hamilton F, Arnold D, Milne A, Lewis PA, Heesom KJ, Mundell SJ, Davidson AD, Poole AW, Hers I. Alterations in platelet proteome signature and impaired platelet integrin α IIbβ 3 activation in patients with COVID-19. J Thromb Haemost 2023; 21:1307-1321. [PMID: 36716966 PMCID: PMC9883069 DOI: 10.1016/j.jtha.2023.01.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/18/2023] [Accepted: 01/19/2023] [Indexed: 01/30/2023]
Abstract
BACKGROUND Patients with COVID-19 are at increased risk of thrombosis, which is associated with altered platelet function and coagulopathy, contributing to excess mortality. OBJECTIVES To characterize the mechanism of altered platelet function in COVID-19 patients. METHODS The platelet proteome, platelet functional responses, and platelet-neutrophil aggregates were compared between patients hospitalized with COVID-19 and healthy control subjects using tandem mass tag proteomic analysis, Western blotting, and flow cytometry. RESULTS COVID-19 patients showed a different profile of platelet protein expression (858 altered of the 5773 quantified). Levels of COVID-19 plasma markers were enhanced in the platelets of COVID-19 patients. Gene ontology pathway analysis demonstrated that the levels of granule secretory proteins were raised, whereas those of platelet activation proteins, such as the thrombopoietin receptor and protein kinase Cα, were lowered. Basally, platelets of COVID-19 patients showed enhanced phosphatidylserine exposure, with unaltered integrin αIIbβ3 activation and P-selectin expression. Agonist-stimulated integrin αIIbβ3 activation and phosphatidylserine exposure, but not P-selectin expression, were decreased in COVID-19 patients. COVID-19 patients had high levels of platelet-neutrophil aggregates, even under basal conditions, compared to controls. This association was disrupted by blocking P-selectin, demonstrating that platelet P-selectin is critical for the interaction. CONCLUSIONS Overall, our data suggest the presence of 2 platelet populations in patients with COVID-19: one of circulating platelets with an altered proteome and reduced functional responses and another of P-selectin-expressing neutrophil-associated platelets. Platelet-driven thromboinflammation may therefore be one of the key factors enhancing the risk of thrombosis in COVID-19 patients.
Collapse
Affiliation(s)
- Lucy J Goudswaard
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK; Population Health Sciences, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK. https://twitter.com/lucygoudswaard
| | - Christopher M Williams
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Jawad Khalil
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Kate L Burley
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Fergus Hamilton
- Population Health Sciences, Oakfield House, Oakfield Grove, Bristol, BS8 2BN, UK; Department of Infection Sciences, North Bristol NHS Trust, Bristol, BS10 5NB, UK
| | - David Arnold
- Academic Respiratory Unit, North Bristol NHS Trust, Bristol, BS10 5NB, UK
| | - Alice Milne
- Academic Respiratory Unit, North Bristol NHS Trust, Bristol, BS10 5NB, UK
| | - Phil A Lewis
- Proteomics Facility, Faculty of Life Sciences, University Walk, University of Bristol, Bristol, BS8 1TD, UK
| | - Kate J Heesom
- Proteomics Facility, Faculty of Life Sciences, University Walk, University of Bristol, Bristol, BS8 1TD, UK
| | - Stuart J Mundell
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Andrew D Davidson
- School of Cellular and Molecular Medicine, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Alastair W Poole
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.
| |
Collapse
|
7
|
Goudswaard LJ, Corbin LJ, Burley KL, Mumford A, Akbari P, Soranzo N, Butterworth AS, Watkins NA, Pournaras DJ, Harris J, Timpson NJ, Hers I. Higher body mass index raises immature platelet count: potential contribution to obesity-related thrombosis. Platelets 2022; 33:869-878. [PMID: 35068290 DOI: 10.1080/09537104.2021.2003317] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/08/2021] [Accepted: 10/21/2021] [Indexed: 02/02/2023]
Abstract
Higher body mass index (BMI) is a risk factor for thrombosis. Platelets are essential for hemostasis but contribute to thrombosis when activated pathologically. We hypothesized that higher BMI leads to changes in platelet characteristics, thereby increasing thrombotic risk. The effect of BMI on platelet traits (measured by Sysmex) was explored in 33 388 UK blood donors (INTERVAL study). Linear regression showed that higher BMI was positively associated with greater plateletcrit (PCT), platelet count (PLT), immature platelet count (IPC), and side fluorescence (SFL, a measure of mRNA content used to derive IPC). Mendelian randomization (MR), applied to estimate a causal effect with BMI proxied by a genetic risk score, provided causal estimates for a positive effect of BMI on both SFL and IPC, but there was little evidence for a causal effect of BMI on PCT or PLT. Follow-up analyses explored the functional relevance of platelet characteristics in a pre-operative cardiac cohort (COPTIC). Linear regression provided observational evidence for a positive association between IPC and agonist-induced whole blood platelet aggregation. Results indicate that higher BMI raises the number of immature platelets, which is associated with greater whole blood platelet aggregation in a cardiac cohort. Higher IPC could therefore contribute to obesity-related thrombosis.
Collapse
Affiliation(s)
- Lucy J Goudswaard
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Bristol Heart Institute, Bristol, UK
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
- Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Laura J Corbin
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
- Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Kate L Burley
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - Andrew Mumford
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Parsa Akbari
- Department of Public Health and Primary Care, British Heart Foundation Cardiovascular Epidemiology Unit, University of Cambridge, Cambridge, UK
- National Institute for Health Research Blood and Transplant Research Unit (NIHR BTRU) in Donor Health and Genomics, University of Cambridge, Cambridge, UK
- MRC Biostatistics Unit, University of Cambridge, Cambridge, UK
- Human Genetics, Wellcome Sanger Institute, Hinxton, UK
| | - Nicole Soranzo
- National Institute for Health Research Blood and Transplant Research Unit (NIHR BTRU) in Donor Health and Genomics, University of Cambridge, Cambridge, UK
- Human Genetics, Wellcome Sanger Institute, Hinxton, UK
- Department of Haematology, School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Adam S Butterworth
- Department of Public Health and Primary Care, British Heart Foundation Cardiovascular Epidemiology Unit, University of Cambridge, Cambridge, UK
- National Institute for Health Research Blood and Transplant Research Unit (NIHR BTRU) in Donor Health and Genomics, University of Cambridge, Cambridge, UK
- British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, University of Cambridge and Cambridge University Hospitals, Cambridge, UK
- Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge, UK
| | | | - Dimitri J Pournaras
- Department of Bariatric and Metabolic Surgery, Southmead Hospital, North Bristol NHS Trust, Bristol, UK
| | - Jessica Harris
- Bristol Trials Centre, Faculty of Health Sciences, University of Bristol, Bristol, UK
| | - Nicholas J Timpson
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
- Department of Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Bristol Heart Institute, Bristol, UK
| |
Collapse
|
8
|
Goudswaard LJ, Bell JA, Hughes DA, Corbin LJ, Walter K, Davey Smith G, Soranzo N, Danesh J, Di Angelantonio E, Ouwehand WH, Watkins NA, Roberts DJ, Butterworth AS, Hers I, Timpson NJ. Effects of adiposity on the human plasma proteome: observational and Mendelian randomisation estimates. Int J Obes (Lond) 2021; 45:2221-2229. [PMID: 34226637 PMCID: PMC8455324 DOI: 10.1038/s41366-021-00896-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 02/06/2023]
Abstract
BACKGROUND Variation in adiposity is associated with cardiometabolic disease outcomes, but mechanisms leading from this exposure to disease are unclear. This study aimed to estimate effects of body mass index (BMI) on an extensive set of circulating proteins. METHODS We used SomaLogic proteomic data from up to 2737 healthy participants from the INTERVAL study. Associations between self-reported BMI and 3622 unique plasma proteins were explored using linear regression. These were complemented by Mendelian randomisation (MR) analyses using a genetic risk score (GRS) comprised of 654 BMI-associated polymorphisms from a recent genome-wide association study (GWAS) of adult BMI. A disease enrichment analysis was performed using DAVID Bioinformatics 6.8 for proteins which were altered by BMI. RESULTS Observationally, BMI was associated with 1576 proteins (P < 1.4 × 10-5), with particularly strong evidence for a positive association with leptin and fatty acid-binding protein-4 (FABP4), and a negative association with sex hormone-binding globulin (SHBG). Observational estimates were likely confounded, but the GRS for BMI did not associate with measured confounders. MR analyses provided evidence for a causal relationship between BMI and eight proteins including leptin (0.63 standard deviation (SD) per SD BMI, 95% CI 0.48-0.79, P = 1.6 × 10-15), FABP4 (0.64 SD per SD BMI, 95% CI 0.46-0.83, P = 6.7 × 10-12) and SHBG (-0.45 SD per SD BMI, 95% CI -0.65 to -0.25, P = 1.4 × 10-5). There was agreement in the magnitude of observational and MR estimates (R2 = 0.33) and evidence that proteins most strongly altered by BMI were enriched for genes involved in cardiovascular disease. CONCLUSIONS This study provides evidence for a broad impact of adiposity on the human proteome. Proteins strongly altered by BMI include those involved in regulating appetite, sex hormones and inflammation; such proteins are also enriched for cardiovascular disease-related genes. Altogether, results help focus attention onto new proteomic signatures of obesity-related disease.
Collapse
Affiliation(s)
- Lucy J Goudswaard
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, UK.
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
- Bristol Heart Institute, Bristol, UK.
| | - Joshua A Bell
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - David A Hughes
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Laura J Corbin
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | | | - George Davey Smith
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Nicole Soranzo
- Wellcome Sanger Institute, Hinxton, UK
- Department of Haematology, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- NIHR Blood and Transplant Research Unit in Donor Health and Genomics, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
| | - John Danesh
- Wellcome Sanger Institute, Hinxton, UK
- NIHR Blood and Transplant Research Unit in Donor Health and Genomics, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, University of Cambridge and Cambridge University Hospitals, Cambridge, UK
- Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge, UK
| | - Emanuele Di Angelantonio
- NIHR Blood and Transplant Research Unit in Donor Health and Genomics, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, University of Cambridge and Cambridge University Hospitals, Cambridge, UK
- Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge, UK
| | - Willem H Ouwehand
- Wellcome Sanger Institute, Hinxton, UK
- Department of Haematology, School of Clinical Medicine, University of Cambridge, Cambridge, UK
- British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge, UK
- NHS Blood and Transplant, Cambridge Biomedical Campus, Cambridge, UK
| | | | - David J Roberts
- NIHR Blood and Transplant Research Unit in Donor Health and Genomics, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- NHS Blood and Transplant-Oxford Centre, Level 2, John Radcliffe Hospital, Oxford, UK
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Adam S Butterworth
- NIHR Blood and Transplant Research Unit in Donor Health and Genomics, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- British Heart Foundation Centre of Research Excellence, University of Cambridge, Cambridge, UK
- NIHR Cambridge Biomedical Research Centre, University of Cambridge and Cambridge University Hospitals, Cambridge, UK
- Health Data Research UK Cambridge, Wellcome Genome Campus and University of Cambridge, Cambridge, UK
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
- Bristol Heart Institute, Bristol, UK
| | - Nicholas J Timpson
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, UK
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| |
Collapse
|
9
|
Moore SF, Agbani EO, Wersäll A, Poole AW, Williams CM, Zhao X, Li Y, Hutchinson JL, Hunter RW, Hers I. Opposing Roles of GSK3α and GSK3β Phosphorylation in Platelet Function and Thrombosis. Int J Mol Sci 2021; 22:10656. [PMID: 34638997 PMCID: PMC8508950 DOI: 10.3390/ijms221910656] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/16/2021] [Accepted: 09/22/2021] [Indexed: 11/25/2022] Open
Abstract
One of the mechanisms by which PI3 kinase can regulate platelet function is through phosphorylation of downstream substrates, including glycogen synthase kinase-3 (GSK3)α and GSK3β. Platelet activation results in the phosphorylation of an N-terminal serine residue in GSK3α (Ser21) and GSK3β (Ser9), which competitively inhibits substrate phosphorylation. However, the role of phosphorylation of these paralogs is still largely unknown. Here, we employed GSK3α/β phosphorylation-resistant mouse models to explore the role of this inhibitory phosphorylation in regulating platelet activation. Expression of phosphorylation-resistant GSK3α/β reduced thrombin-mediated platelet aggregation, integrin αIIbβ3 activation, and α-granule secretion, whereas platelet responses to the GPVI agonist collagen-related peptide (CRP-XL) were significantly enhanced. GSK3 single knock-in lines revealed that this divergence is due to differential roles of GSK3α and GSK3β phosphorylation in regulating platelet function. Expression of phosphorylation-resistant GSK3α resulted in enhanced GPVI-mediated platelet activation, whereas expression of phosphorylation-resistant GSK3β resulted in a reduction in PAR-mediated platelet activation and impaired in vitro thrombus formation under flow. Interestingly, the latter was normalised in double GSK3α/β KI mice, indicating that GSK3α KI can compensate for the impairment in thrombosis caused by GSK3β KI. In conclusion, our data indicate that GSK3α and GSK3β have differential roles in regulating platelet function.
Collapse
Affiliation(s)
- Samantha F. Moore
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
| | - Ejaife O. Agbani
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Andreas Wersäll
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
| | - Alastair W. Poole
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
| | - Chris M. Williams
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
| | - Xiaojuan Zhao
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
| | - Yong Li
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
| | - James L. Hutchinson
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
| | - Roger W. Hunter
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
- NHS Blood and Transplant, North Bristol Park, Filton, Bristol BS34 7QH, UK
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK; (S.F.M.); (E.O.A.); (A.W.); (A.W.P.); (C.M.W.); (X.Z.); (Y.L.); (J.L.H.); (R.W.H.)
| |
Collapse
|
10
|
Goudswaard L, Bell J, Hughes D, Walter K, Soranzo N, Butterworth A, Hers I, Timpson N. 204Effects of adiposity on the human proteome: Mendelian randomization study using individual-level data. Int J Epidemiol 2021. [DOI: 10.1093/ije/dyab168.235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Variation in body mass index (BMI) is associated with cardiometabolic health outcomes such as diabetes, but the mechanism(s) leading from BMI to disease remain unclear. This study used proteomic data measured by SomaLogic from healthy adults from the INTERVAL study to explore the effect of BMI on 3,622 unique plasma proteins using observational and genetically informed methods.
Methods
Linear regression models were used, complemented by one-sample Mendelian randomization (MR) analyses. A BMI genetic risk score (GRS) comprised of 654 SNPs from a recent genome-wide association study (GWAS) of adult BMI was used in both observational and MR analysis.
Results
Observationally, BMI was associated with 1,576 proteins at p <1.4x10-5 including leptin and sex hormone binding globulin (SHBG). The BMI-GRS was positively associated with BMI (R2=0.028) but not with reported confounders. MR analysis indicated a causal association between each standard deviation increase in BMI and eight unique proteins at p <1.4x10-5, including leptin (0.63 SD, 95% CI 0.48-0.79, p = 1.6x10-15) and SHBG (-0.45 SD, 95% CI -0.65 to -0.25, p = 1.4x10-5). There was strong agreement in the direction and magnitude of observational and MR estimates (R2 = 0.33).
Finally, there was evidence that proteins which showed associations with BMI were enriched in cardiovascular disease.
Conclusions
This study provides evidence for a profound impact of higher adiposity on the human proteome. Such protein alterations could be important mechanistic drivers of obesity-related diseases.
Key messages
Changes in plasma proteins could be important intermediates between obesity and the onset of disease.
Collapse
Affiliation(s)
- Lucy Goudswaard
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, United Kingdom
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Joshua Bell
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, United Kingdom
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - David Hughes
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, United Kingdom
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | | | - Nicole Soranzo
- Wellcome Sanger Institute, Hinxton, United Kingdom
- MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
- NIHR Blood and Transplant Research Unit in Donor Health and Genomics, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
| | - Adam Butterworth
- MRC/BHF Cardiovascular Epidemiology Unit, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
- NIHR Blood and Transplant Research Unit in Donor Health and Genomics, Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Nicholas Timpson
- Medical Research Council (MRC) Integrative Epidemiology Unit at the University of Bristol, Bristol, United Kingdom
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
11
|
Hers I, Mundell SJ. GPR56, a novel platelet collagen receptor that loves stress. J Thromb Haemost 2021; 19:1848-1851. [PMID: 33908157 DOI: 10.1111/jth.15335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 03/31/2021] [Accepted: 03/31/2021] [Indexed: 12/25/2022]
Affiliation(s)
- Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, UK
| | - Stuart J Mundell
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, UK
| |
Collapse
|
12
|
Liu H, Jackson ML, Goudswaard LJ, Moore SF, Hutchinson JL, Hers I. Sphingosine-1-phosphate modulates PAR1-mediated human platelet activation in a concentration-dependent biphasic manner. Sci Rep 2021; 11:15308. [PMID: 34321503 PMCID: PMC8319165 DOI: 10.1038/s41598-021-94052-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 06/18/2021] [Indexed: 11/08/2022] Open
Abstract
Sphingosine 1-phosphate (S1P) is a bioactive signalling sphingolipid that is increased in diseases such as obesity and diabetes. S1P can modulate platelet function, however the direction of effect and S1P receptors (S1PRs) involved are controversial. Here we describe the role of S1P in regulating human platelet function and identify the receptor subtypes responsible for S1P priming. Human platelets were treated with protease-activated receptor 1 (PAR-1)-activating peptide in the presence or absence of S1P, S1PR agonists or antagonists, and sphingosine kinases inhibitors. S1P alone did not induce platelet aggregation but at low concentrations S1P enhanced PAR1-mediated platelet responses, whereas PAR1 responses were inhibited by high concentrations of S1P. This biphasic effect was mimicked by pan-S1PR agonists. Specific agonists revealed that S1PR1 receptor activation has a positive priming effect, S1PR2 and S1PR3 have no effect on platelet function, whereas S1PR4 and S1PR5 receptor activation have an inhibitory effect on PAR-1 mediated platelet function. Although platelets express both sphingosine kinase 1/2, enzymes which phosphorylate sphingosine to produce S1P, only dual and SphK2 inhibition reduced platelet function. These results support a role for SphK2-mediated S1P generation in concentration-dependent positive and negative priming of platelet function, through S1PR1 and S1PR4/5 receptors, respectively.
Collapse
Affiliation(s)
- Haonan Liu
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Molly L Jackson
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Lucy J Goudswaard
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
- Population Health Sciences, Oakfield House, University of Bristol, Bristol, BS8 2BN, UK
| | - Samantha F Moore
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - James L Hutchinson
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK.
| |
Collapse
|
13
|
Jing C, Mallah S, Kriemen E, Bennett SH, Fasano V, Lennox AJJ, Hers I, Aggarwal VK. Synthesis, Stability, and Biological Studies of Fluorinated Analogues of Thromboxane A 2. ACS Cent Sci 2020; 6:995-1000. [PMID: 32607446 PMCID: PMC7318075 DOI: 10.1021/acscentsci.0c00310] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Indexed: 06/11/2023]
Abstract
Platelet activation results in the generation of thromboxane A2 (TxA2), which promotes thrombus formation by further amplifying platelet function, as well as causing vasoconstriction. Due to its role in thrombus formation and cardiovascular disease, its production is the target of antiplatelet drugs such as aspirin. However, the study of TxA2-stimulated cellular function has been limited by its instability (t 1/2 = 32 s, pH = 7.4). Although more stable analogues such as U46619 and difluorinated 10,10-F2-TxA2 have been prepared, we targeted a closer mimic to TxA2 itself, monofluorinated 10-F-TxA2, since the number of fluorine atoms can affect function. Key steps in the synthesis of F-TxA2 included α-fluorination of a lactone bearing a β-alkoxy group, and a novel synthesis of the strained acetal. F-TxA2 was found to be 105 more stable than TxA2, and surprisingly was only slightly less stable than F2-TxA2. Preliminary biological studies showed that F-TxA2 has similar potency as TxA2 toward inducing platelet aggregation but was superior to F2-TxA2 in activating integrin αIIbβ3.
Collapse
Affiliation(s)
- Changcheng Jing
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Shahida Mallah
- School
of Physiology, Pharmacology & Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Ella Kriemen
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Steven H. Bennett
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Valerio Fasano
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Alastair J. J. Lennox
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| | - Ingeborg Hers
- School
of Physiology, Pharmacology & Neuroscience, University of Bristol, University Walk, Biomedical Sciences Building, Bristol BS8 1TD, United Kingdom
| | - Varinder K. Aggarwal
- School
of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom
| |
Collapse
|
14
|
Śledź KM, Moore SF, Durrant TN, Blair TA, Hunter RW, Hers I. Rapamycin restrains platelet procoagulant responses via FKBP-mediated protection of mitochondrial integrity. Biochem Pharmacol 2020; 177:113975. [PMID: 32298692 DOI: 10.1016/j.bcp.2020.113975] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/09/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND PURPOSE Rapamycin is a potent immunosuppressant and anti-proliferative agent used clinically to prevent organ transplant rejection and for coating coronary stents to counteract restenosis. Rapamycin complexes with the immunophilin FKBP12, which subsequently binds and inhibits mTORC1. Despite several reports demonstrating that rapamycin affects platelet-mediated responses, the underlying mechanism of how it alters platelet function is poorly characterised. This study aimed to elucidate the effect of rapamycin on platelet procoagulant responses. EXPERIMENTAL APPROACH The effect of rapamycin on platelet activation and signalling was investigated alongside the catalytic mTOR inhibitors KU0063794 and WYE-687, and the FKBP12-binding macrolide FK506. KEY RESULTS Rapamycin affects platelet procoagulant responses by reducing externalisation of the procoagulant phospholipid phosphatidylserine, formation of balloon-like structures and local generation of thrombin. Catalytic mTOR kinase inhibitors did not alter platelet procoagulant processes, despite having a similar effect as rapamycin on Ca2+ signalling, demonstrating that the effect of rapamycin on procoagulant responses is independent of mTORC1 inhibition and not linked to a reduction in Ca2+ signalling. FK506, which also forms a complex with FKBP12 but does not target mTOR, reduced platelet procoagulant responses to a similar extent as rapamycin. Both rapamycin and FK506 prevented the loss of mitochondria integrity induced by platelet activation, one of the central regulatory events leading to PS externalisation. CONCLUSIONS AND IMPLICATIONS Rapamycin suppresses platelet procoagulant responses by protecting mitochondrial integrity in a manner independent of mTORC1 inhibition. Rapamycin and other drugs targeting FKBP immunophilins could aid the development of novel complementary anti-platelet therapies.
Collapse
Affiliation(s)
- Kamila M Śledź
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Samantha F Moore
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Tom N Durrant
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Thomas A Blair
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Roger W Hunter
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, United Kingdom.
| |
Collapse
|
15
|
Sledz KM, Moore SF, Vijayaragavan V, Mallah S, Goudswaard LJ, Williams CM, Hunter RW, Hers I. Redundant role of ASK1-mediated p38MAPK activation in human platelet function. Cell Signal 2020; 68:109528. [PMID: 31917191 DOI: 10.1016/j.cellsig.2020.109528] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 12/20/2019] [Accepted: 01/03/2020] [Indexed: 10/25/2022]
Abstract
Apoptosis signal-regulating kinase 1 (ASK1) is a member of mitogen-activated protein kinase kinase kinase (MAP3K) family, which recently has been implicated in the regulation of p38 MAPK/PLA2/thromboxane (TxA2) generation, as well as P2Y12 signalling in murine platelets. ASK1 has therefore been proposed as a potential target for anti-thrombotic therapy. At present it is unknown whether ASK1 also contributes to TxA2 formation and platelet function in human. In this study we therefore examined the role of ASK1 using the ASK1 inhibitor selonsertib (GS-4997). We established that ASK1 is responsible for p38 phosphorylation and TxA2 formation in murine platelets, with both GS4997 and p38 inhibitors reducing TxA2 formation. Similar to murine platelets, activation of human platelets resulted in the rapid and transient phosphorylation of ASK1 and the MAP2Ks MMK3/4/6. In contrast, phosphorylation of p38 and its substrate; MAPKAP-kinase2 (MAPKAPK2) was much more sustained. In keeping with these findings, inhibition of ASK1 blocked early, but not later p38/MAPKAPK2 phosphorylation. The latter was dependent on non-canonical autophosphorylation as it was blocked by the p38 inhibitor; SB203580 and the SYK inhibitor; R406. Furthermore, ASK1 and p38 inhibitors had no effect on PLA2 phosphorylation, TxA2 formation and platelet aggregation, demonstrating that this pathway is redundant in human platelets. Together, these results demonstrate that ASK1 contributes to TxA2 formation in murine, but not human platelets and highlight the importance of confirming findings from genetic murine models in humans.
Collapse
Affiliation(s)
- Kamila M Sledz
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Samantha F Moore
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Vijayasameerah Vijayaragavan
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Shahida Mallah
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Lucy J Goudswaard
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Christopher M Williams
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Roger W Hunter
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University of Bristol, Bristol BS8 1TD, United Kingdom.
| |
Collapse
|
16
|
Durrant TN, Moore SF, Bayliss AL, Jiang Y, Aitken EW, Wilson MC, Heesom KJ, Hers I. Identification of PtdIns(3,4)P2 effectors in human platelets using quantitative proteomics. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158575. [DOI: 10.1016/j.bbalip.2019.158575] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 09/20/2019] [Accepted: 10/29/2019] [Indexed: 12/26/2022]
|
17
|
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
|
18
|
Agbani EO, Zhao X, Williams CM, Aungraheeta R, Hers I, Swenson ER, Poole AW. Carbonic Anhydrase Inhibitors suppress platelet procoagulant responses and in vivo thrombosis. Platelets 2020; 31:853-859. [PMID: 31893963 DOI: 10.1080/09537104.2019.1709632] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Carbonic anhydrase (CA) inhibitors have a long history of safe clinical use as mild diuretics, in the treatment of glaucoma and for altitude sickness prevention. In this study, we aimed to determine if CA inhibition may be an alternative approach to control thrombosis. We utilized a high-resolution dynamic imaging approach to provide mechanistic evidence that CA inhibitors may be potent anti-procoagulant agents in vitro and effective anti-thrombotics in vivo. Acetazolamide and methazolamide, while sparing platelet secretion, attenuated intracellular chloride ion entry and suppressed the procoagulant response of activated platelets in vitro and thrombosis in vivo. The chemically similar N-methyl acetazolamide, which lacks CA inhibitory activity, did not affect platelet procoagulant response in vitro. Outputs from rotational thromboelastometry did not reflect changes in procoagulant activity and reveal the need for a suitable clinical test for procoagulant activity. Drugs specifically targeting procoagulant remodeling of activated platelets, by blockade of carbonic anhydrases, may provide a new way to control platelet-driven thrombosis without blocking essential platelet secretion responses.
Collapse
Affiliation(s)
- Ejaife O Agbani
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol, UK.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary , Calgary, Alberta, Canada.,Vascular Basic Science, Libin Cardiovascular Institute of Alberta , Calgary, Alberta, Canada
| | - Xiaojuan Zhao
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol, UK
| | - Christopher M Williams
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol, UK
| | - Riyaad Aungraheeta
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol, UK
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol, UK
| | - Erik R Swenson
- Division of Pulmonary, Critical Care and Sleep Medicine, Medical Service, VA Puget Sound Health Care System, University of Washington , Seattle, WA, USA
| | - Alastair W Poole
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol, UK
| |
Collapse
|
19
|
Agbani EO, Hers I, Poole AW. Letter by Agbani et al Regarding Article, "Clot Contraction Drives the Translocation of Procoagulant Platelets to Thrombus Surface". Arterioscler Thromb Vasc Biol 2019; 39:e287-e289. [PMID: 31770030 DOI: 10.1161/atvbaha.119.313468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Ejaife O Agbani
- From the Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Alberta, Canada (E.O.A.)
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, England, United Kingdom (I.H., A.W.P.)
| | - Alastair W Poole
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, England, United Kingdom (I.H., A.W.P.)
| |
Collapse
|
20
|
McCormick B, Craig HE, Chu JY, Carlin LM, Canel M, Wollweber F, Toivakka M, Michael M, Astier AL, Norton L, Lilja J, Felton JM, Sasaki T, Ivaska J, Hers I, Dransfield I, Rossi AG, Vermeren S. A Negative Feedback Loop Regulates Integrin Inactivation and Promotes Neutrophil Recruitment to Inflammatory Sites. J Immunol 2019; 203:1579-1588. [PMID: 31427445 PMCID: PMC6731454 DOI: 10.4049/jimmunol.1900443] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/16/2019] [Indexed: 01/08/2023]
Abstract
Neutrophils are abundant circulating leukocytes that are rapidly recruited to sites of inflammation in an integrin-dependent fashion. Contrasting with the well-characterized regulation of integrin activation, mechanisms regulating integrin inactivation remain largely obscure. Using mouse neutrophils, we demonstrate in this study that the GTPase activating protein ARAP3 is a critical regulator of integrin inactivation; experiments with Chinese hamster ovary cells indicate that this is not restricted to neutrophils. Specifically, ARAP3 acts in a negative feedback loop downstream of PI3K to regulate integrin inactivation. Integrin ligand binding drives the activation of PI3K and of its effectors, including ARAP3, by outside-in signaling. ARAP3, in turn, promotes localized integrin inactivation by negative inside-out signaling. This negative feedback loop reduces integrin-mediated PI3K activity, with ARAP3 effectively switching off its own activator, while promoting turnover of substrate adhesions. In vitro, ARAP3-deficient neutrophils display defective PIP3 polarization, adhesion turnover, and transendothelial migration. In vivo, ARAP3-deficient neutrophils are characterized by a neutrophil-autonomous recruitment defect to sites of inflammation.
Collapse
Affiliation(s)
- Barry McCormick
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Helen E Craig
- Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Julia Y Chu
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Leo M Carlin
- Cancer Research UK Beatson Institute, Glasgow G61 1BD, United Kingdom
- Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1BD, United Kingdom
| | - Marta Canel
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Florian Wollweber
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Matilda Toivakka
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Melina Michael
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Anne L Astier
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
- Centre de Physiopathologie Toulouse-Purpan, INSERM U1043, CNRS U5282, Université Toulouse, 31024 Toulouse Cedex 3, France
| | - Laura Norton
- Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, United Kingdom
| | - Johanna Lilja
- Turku Centre for Biotechnology, University of Turku, FI-20520 Turku, Finland
| | - Jennifer M Felton
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Takehiko Sasaki
- Department of Biochemical Pathophysiology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan; and
| | - Johanna Ivaska
- Centre de Physiopathologie Toulouse-Purpan, INSERM U1043, CNRS U5282, Université Toulouse, 31024 Toulouse Cedex 3, France
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol BS8 1TD, United Kingdom
| | - Ian Dransfield
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Adriano G Rossi
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Sonja Vermeren
- Centre for Inflammation Research, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom;
| |
Collapse
|
21
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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
|
22
|
Agbani EO, Williams CM, Li Y, van den Bosch MT, Moore SF, Mauroux A, Hodgson L, Verkman AS, Hers I, Poole AW. Aquaporin-1 regulates platelet procoagulant membrane dynamics and in vivo thrombosis. JCI Insight 2018; 3:99062. [PMID: 29769447 PMCID: PMC6012506 DOI: 10.1172/jci.insight.99062] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 04/12/2018] [Indexed: 01/02/2023] Open
Abstract
In response to collagen stimulation, platelets use a coordinated system of fluid entry to undergo membrane ballooning, procoagulant spreading, and microvesiculation. We hypothesized that water entry was mediated by the water channel aquaporin-1 (AQP1) and aimed to determine its role in the platelet procoagulant response and thrombosis. We established that human and mouse platelets express AQP1 and localize to internal tubular membrane structures. However, deletion of AQP1 had minimal effects on collagen-induced platelet granule secretion, aggregation, or membrane ballooning. Conversely, procoagulant spreading, microvesiculation, phosphatidylserine exposure, and clot formation time were significantly diminished. Furthermore, in vivo thrombus formation after FeCl3 injury to carotid arteries was also markedly suppressed in AQP1-null mice, but hemostasis after tail bleeding remained normal. The mechanism involves an AQP1-mediated rapid membrane stretching during procoagulant spreading but not ballooning, leading to calcium entry through mechanosensitive cation channels and a full procoagulant response. We conclude that AQP1 is a major regulator of the platelet procoagulant response, able to modulate coagulation after injury or pathologic stimuli without affecting other platelet functional responses or normal hemostasis. Clinically effective AQP1 inhibitors may therefore represent a novel class of antiprocoagulant antithrombotics. AQP1 controls platelet procoagulant response and modulates coagulation after injury or pathologic stimuli without affecting other platelet functional responses or normal hemostasis.
Collapse
Affiliation(s)
- Ejaife O Agbani
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Christopher M Williams
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Yong Li
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Marion Tj van den Bosch
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Samantha F Moore
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Adele Mauroux
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Lorna Hodgson
- Wolfson Bioimaging Facility, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Alan S Verkman
- Departments of Medicine and Physiology, University of California San Francisco, San Francisco, California, USA
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| | - Alastair W Poole
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, Bristol, United Kingdom
| |
Collapse
|
23
|
Affiliation(s)
- Ejaife O Agbani
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, UK
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, UK
| | - Alastair W Poole
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Biomedical Sciences Building, UK
| |
Collapse
|
24
|
Battram AM, Durrant TN, Agbani EO, Heesom KJ, Paul DS, Piatt R, Poole AW, Cullen PJ, Bergmeier W, Moore SF, Hers I. The Phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) Binder Rasa3 Regulates Phosphoinositide 3-kinase (PI3K)-dependent Integrin αIIbβ3 Outside-in Signaling. J Biol Chem 2017; 292:1691-1704. [PMID: 27903653 PMCID: PMC5290945 DOI: 10.1074/jbc.m116.746867] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 11/14/2016] [Indexed: 11/16/2022] Open
Abstract
The class I PI3K family of lipid kinases plays an important role in integrin αIIbβ3 function, thereby supporting thrombus growth and consolidation. Here, we identify Ras/Rap1GAP Rasa3 (GAP1IP4BP) as a major phosphatidylinositol 3,4,5-trisphosphate-binding protein in human platelets and a key regulator of integrin αIIbβ3 outside-in signaling. We demonstrate that cytosolic Rasa3 translocates to the plasma membrane in a PI3K-dependent manner upon activation of human platelets. Expression of wild-type Rasa3 in integrin αIIbβ3-expressing CHO cells blocked Rap1 activity and integrin αIIbβ3-mediated spreading on fibrinogen. In contrast, Rap1GAP-deficient (P489V) and Ras/Rap1GAP-deficient (R371Q) Rasa3 had no effect. We furthermore show that two Rasa3 mutants (H794L and G125V), which are expressed in different mouse models of thrombocytopenia, lack both Ras and Rap1GAP activity and do not affect integrin αIIbβ3-mediated spreading of CHO cells on fibrinogen. Platelets from thrombocytopenic mice expressing GAP-deficient Rasa3 (H794L) show increased spreading on fibrinogen, which in contrast to wild-type platelets is insensitive to PI3K inhibitors. Together, these results support an important role for Rasa3 in PI3K-dependent integrin αIIbβ3-mediated outside-in signaling and cell spreading.
Collapse
Affiliation(s)
- Anthony M Battram
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Tom N Durrant
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Ejaife O Agbani
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Kate J Heesom
- School of Biochemistry, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - David S Paul
- the McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514
| | - Raymond Piatt
- the McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514
| | - Alastair W Poole
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Peter J Cullen
- School of Biochemistry, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Wolfgang Bergmeier
- the McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514; Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514
| | - Samantha F Moore
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom
| | - Ingeborg Hers
- From the School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, BS8 1TD, United Kingdom.
| |
Collapse
|
25
|
Abstract
Platelets are critical for maintaining vascular hemostasis, but also play a major role in the formation of occlusive cardiovascular and cerebrovascular thrombi under disease conditions. Secretion of platelet alpha and dense granules is a requirement for efficient thrombus formation. Understanding and targeting the mechanisms of secretion is important to aid the development of effective antithrombotics. SNAP29 is a tSNARE found in platelets, but whose role has not been defined. Using a platelet-specific SNAP29 knockout mouse model, we assessed the role of SNAP29 in platelet secretion and function under standardized conditions and also in in vitro and in vivo thrombosis. The data showed no major defects in SNAP29-null platelets, but revealed a minor defect in α-granule secretion and a significant increase in embolization rate of thrombi in vivo. These data suggest that SNAP29 contributes to the regulation of platelet α-granule secretion and thrombus stability, possibly partially masked by functional redundancy with other tSNAREs, such as SNAP23.
Collapse
Affiliation(s)
- C M Williams
- a School of Physiology & Pharmacology , University of Bristol , Bristol , UK
| | - J S Savage
- a School of Physiology & Pharmacology , University of Bristol , Bristol , UK.,b Cancer Research UK Clinical Trials Unit (CRCTU), School of Cancer Sciences , University of Birmingham , Edgbaston, Birmingham , UK
| | - M T Harper
- a School of Physiology & Pharmacology , University of Bristol , Bristol , UK.,c Department of Pharmacology , University of Cambridge , Cambridge , UK
| | - S F Moore
- a School of Physiology & Pharmacology , University of Bristol , Bristol , UK
| | - I Hers
- a School of Physiology & Pharmacology , University of Bristol , Bristol , UK
| | - A W Poole
- a School of Physiology & Pharmacology , University of Bristol , Bristol , UK
| |
Collapse
|
26
|
Agbani EO, van den Bosch MTJ, Brown E, Williams CM, Mattheij NJA, Cosemans JMEM, Collins PW, Heemskerk JWM, Hers I, Poole AW. Coordinated Membrane Ballooning and Procoagulant Spreading in Human Platelets. Circulation 2015; 132:1414-24. [PMID: 26330411 DOI: 10.1161/circulationaha.114.015036] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 07/30/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Platelets are central to the process of hemostasis, rapidly aggregating at sites of blood vessel injury and acting as coagulation nidus sites. On interaction with the subendothelial matrix, platelets are transformed into balloonlike structures as part of the hemostatic response. It remains unclear, however, how and why platelets generate these structures. We set out to determine the physiological relevance and cellular and molecular mechanisms underlying platelet membrane ballooning. METHODS AND RESULTS Using 4-dimensional live-cell imaging and electron microscopy, we show that human platelets adherent to collagen are transformed into phosphatidylserine-exposing balloonlike structures with expansive macro/microvesiculate contact surfaces, by a process that we termed procoagulant spreading. We reveal that ballooning is mechanistically and structurally distinct from membrane blebbing and involves disruption to the platelet microtubule cytoskeleton and inflation through fluid entry. Unlike blebbing, procoagulant ballooning is irreversible and a consequence of Na(+), Cl(-), and water entry. Furthermore, membrane ballooning correlated with microparticle generation. Inhibition of Na(+), Cl(-), or water entry impaired ballooning, procoagulant spreading, and microparticle generation, and it also diminished local thrombin generation. Human Scott syndrome platelets, which lack expression of Ano-6, also showed a marked reduction in membrane ballooning, consistent with a role for chloride entry in the process. Finally, the blockade of water entry by acetazolamide attenuated ballooning in vitro and markedly suppressed thrombus formation in vivo in a mouse model of thrombosis. CONCLUSIONS Ballooning and procoagulant spreading of platelets are driven by fluid entry into the cells, and are important for the amplification of localized coagulation in thrombosis.
Collapse
Affiliation(s)
- Ejaife O Agbani
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.).
| | - Marion T J van den Bosch
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Ed Brown
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Christopher M Williams
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Nadine J A Mattheij
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Judith M E M Cosemans
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Peter W Collins
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Johan W M Heemskerk
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Ingeborg Hers
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.)
| | - Alastair W Poole
- From School of Physiology & Pharmacology, University of Bristol, United Kingdom (E.O.A., M.T.J.v.d.B., E.B., C.M.W., I.H., A.W.P.; Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), University of Maastricht, The Netherlands (N.J.A.M., J.M.E.M.C., J.W.M.H.); and Welsh Blood Service and Arthur Bloom Haemophilia Centre, School of Medicine, Cardiff University, United Kingdom (P.W.C.).
| |
Collapse
|
27
|
Blair TA, Moore SF, Hers I. Circulating primers enhance platelet function and induce resistance to antiplatelet therapy. J Thromb Haemost 2015; 13:1479-93. [PMID: 26039631 PMCID: PMC4599128 DOI: 10.1111/jth.13022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Accepted: 05/08/2015] [Indexed: 01/16/2023]
Abstract
BACKGROUND Aspirin and P2Y12 antagonists are antiplatelet compounds that are used clinically in patients with thrombosis. However, some patients are 'resistant' to antiplatelet therapy, which increases their risk of developing acute coronary syndromes. These patients often present with an underlying condition that is associated with altered levels of circulating platelet primers and platelet hyperactivity. Platelet primers cannot stimulate platelet activation, but, in combination with physiologic stimuli, significantly enhance platelet function. OBJECTIVES To explore the role of platelet primers in resistance to antiplatelet therapy, and to evaluate whether phosphoinositide 3-kinase (PI3K) contributes to this process. METHODS AND RESULTS We used platelet aggregation, thromboxane A2 production and ex vivo thrombus formation as functional readouts of platelet activity. Platelets were treated with the potent P2Y12 inhibitor AR-C66096, aspirin, or a combination of both, in the presence or absence of the platelet primers insulin-like growth factor-1 (IGF-1) and thrombopoietin (TPO), or the Gz-coupled receptor ligand epinephrine. We found that platelet primers largely overcame the inhibitory effects of antiplatelet compounds on platelet functional responses. IGF-1-mediated and TPO-mediated, but not epinephrine-mediated, enhancements in the presence of antiplatelet drugs were blocked by the PI3K inhibitors wortmannin and LY294002. CONCLUSIONS These results demonstrate that platelet primers can contribute to antiplatelet resistance. Furthermore, our data demonstrate that there are PI3K-dependent and PI3K-independent mechanisms driving primer-mediated resistance to antiplatelet therapy.
Collapse
Affiliation(s)
- T A Blair
- School of Physiology and Pharmacology, University of Bristol, Bristol, UK
| | - S F Moore
- School of Physiology and Pharmacology, University of Bristol, Bristol, UK
| | - I Hers
- School of Physiology and Pharmacology, University of Bristol, Bristol, UK
| |
Collapse
|
28
|
Moore SF, Williams CM, Brown E, Blair TA, Harper MT, Coward RJ, Poole AW, Hers I. Loss of the insulin receptor in murine megakaryocytes/platelets causes thrombocytosis and alterations in IGF signalling. Cardiovasc Res 2015; 107:9-19. [PMID: 25902782 PMCID: PMC4476412 DOI: 10.1093/cvr/cvv132] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 04/03/2015] [Indexed: 12/21/2022] Open
Abstract
Aims Patients with conditions that are associated with insulin resistance such as obesity, type 2 diabetes mellitus, and polycystic ovary syndrome have an increased risk of thrombosis and a concurrent hyperactive platelet phenotype. Our aim was to determine whether insulin resistance of megakaryocytes/platelets promotes platelet hyperactivation. Methods and results We generated a conditional mouse model where the insulin receptor (IR) was specifically knocked out in megakaryocytes/platelets and performed ex vivo platelet activation studies in wild-type (WT) and IR-deficient platelets by measuring aggregation, integrin αIIbβ3 activation, and dense and α-granule secretion. Deletion of IR resulted in an increase in platelet count and volume, and blocked the action of insulin on platelet signalling and function. Platelet aggregation, granule secretion, and integrin αIIbβ3 activation in response to the glycoprotein VI (GPVI) agonist collagen-related peptide (CRP) were significantly reduced in platelets lacking IR. This was accompanied by a reduction in the phosphorylation of effectors downstream of GPVI. Interestingly, loss of IR also resulted in a reduction in insulin-like growth factor-1 (IGF-1)- and insulin-like growth factor-2 (IGF-2)-mediated phosphorylation of IRS-1, Akt, and GSK3β and priming of CRP-mediated platelet activation. Pharmacological inhibition of IR and the IGF-1 receptor in WT platelets recapitulated the platelet phenotype of IR-deficient platelets. Conclusions Deletion of IR (i) increases platelet count and volume, (ii) does not cause platelet hyperactivity, and (iii) reduces GPVI-mediated platelet function and platelet priming by IGF-1 and IGF-2.
Collapse
Affiliation(s)
- Samantha F Moore
- School of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Medical Sciences Building, Bristol BS8 1TD, UK
| | - Christopher M Williams
- School of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Medical Sciences Building, Bristol BS8 1TD, UK
| | - Edward Brown
- School of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Medical Sciences Building, Bristol BS8 1TD, UK
| | - Thomas A Blair
- School of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Medical Sciences Building, Bristol BS8 1TD, UK
| | - Matthew T Harper
- School of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Medical Sciences Building, Bristol BS8 1TD, UK
| | - Richard J Coward
- School of Clinical Sciences, Dorothy Hodgkin Building, University of Bristol, Bristol BS1 3NY, UK
| | - Alastair W Poole
- School of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Medical Sciences Building, Bristol BS8 1TD, UK
| | - Ingeborg Hers
- School of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, University Walk, Medical Sciences Building, Bristol BS8 1TD, UK
| |
Collapse
|
29
|
Chen MZ, Hudson CA, Vincent EE, de Berker DAR, May MT, Hers I, Dayan CM, Andrews RC, Tavaré JM. Bariatric surgery in morbidly obese insulin resistant humans normalises insulin signalling but not insulin-stimulated glucose disposal. PLoS One 2015; 10:e0120084. [PMID: 25876175 PMCID: PMC4395354 DOI: 10.1371/journal.pone.0120084] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 01/19/2015] [Indexed: 01/14/2023] Open
Abstract
Aims Weight-loss after bariatric surgery improves insulin sensitivity, but the underlying molecular mechanism is not clear. To ascertain the effect of bariatric surgery on insulin signalling, we examined glucose disposal and Akt activation in morbidly obese volunteers before and after Roux-en-Y gastric bypass surgery (RYGB), and compared this to lean volunteers. Materials and Methods The hyperinsulinaemic euglycaemic clamp, at five infusion rates, was used to determine glucose disposal rates (GDR) in eight morbidly obese (body mass index, BMI=47.3±2.2 kg/m2) patients, before and after RYGB, and in eight lean volunteers (BMI=20.7±0.7 kg/m2). Biopsies of brachioradialis muscle, taken at fasting and insulin concentrations that induced half-maximal (GDR50) and maximal (GDR100) GDR in each subject, were used to examine the phosphorylation of Akt-Thr308, Akt-473, and pras40, in vivo biomarkers for Akt activity. Results Pre-operatively, insulin-stimulated GDR was lower in the obese compared to the lean individuals (P<0.001). Weight-loss of 29.9±4 kg after surgery significantly improved GDR50 (P=0.004) but not GDR100 (P=0.3). These subjects still remained significantly more insulin resistant than the lean individuals (p<0.001). Weight loss increased insulin-stimulated skeletal muscle Akt-Thr308 and Akt-Ser473 phosphorylation, P=0.02 and P=0.03 respectively (MANCOVA), and Akt activity towards the substrate PRAS40 (P=0.003, MANCOVA), and in contrast to GDR, were fully normalised after the surgery (obese vs lean, P=0.6, P=0.35, P=0.46, respectively). Conclusions Our data show that although Akt activity substantially improved after surgery, it did not lead to a full restoration of insulin-stimulated glucose disposal. This suggests that a major defect downstream of, or parallel to, Akt signalling remains after significant weight-loss.
Collapse
Affiliation(s)
- Mimi Z. Chen
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Claire A. Hudson
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
| | - Emma E. Vincent
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | | | - Margaret T. May
- School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom
| | - Ingeborg Hers
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - Colin M. Dayan
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Robert C. Andrews
- School of Clinical Sciences, University of Bristol, Bristol, United Kingdom
- * E-mail:
| | - Jeremy M. Tavaré
- School of Biochemistry, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
30
|
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] [What about the content of this article? (0)] [Affiliation(s)] [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
|
31
|
van den Bosch MTJ, Poole AW, Hers I. Cytohesin-2 phosphorylation by protein kinase C relieves the constitutive suppression of platelet dense granule secretion by ADP-ribosylation factor 6. J Thromb Haemost 2014; 12:726-35. [PMID: 24581425 PMCID: PMC4238808 DOI: 10.1111/jth.12542] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 02/19/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND Protein kinase C (PKC) is a major regulator of platelet function and secretion. The underlying molecular pathway from PKC to secretion, however, is poorly understood. By a proteomics screen we identified the guanine nucleotide exchange factor cytohesin-2 as a candidate PKC substrate. OBJECTIVES We aimed to validate cytohesin-2 as a PKC substrate in platelets and to determine its role in granule secretion and other platelet responses. METHODS AND RESULTS Immunoprecipitation was performed with a phosphoserine PKC substrate antibody followed by mass spectrometry, leading to the identification of cytohesin-2. By western blotting we showed that different agonists induced cytohesin-2 phosphorylation by PKC. Protein function was investigated using a pharmacological approach. The cytohesin inhibitor SecinH3 significantly enhanced platelet dense granule secretion and aggregation, as measured by lumi-aggregometry. Flow cytometry data indicate that α-granule release and integrin αII b β3 activation were not affected by cytohesin-2 inhibition. Lysosome secretion was assessed by a colorimetric assay and was also unchanged. As shown by western blotting, ARF6 interacted with cytohesin-2 and was present in an active GTP-bound form under basal conditions. Upon platelet stimulation, this interaction was largely lost and ARF6 activation decreased, both of which could be rescued by PKC inhibition. CONCLUSIONS Cytohesin-2 constitutively suppresses platelet dense granule secretion and aggregation by keeping ARF6 in a GTP-bound state. PKC-mediated phosphorylation of cytohesin-2 relieves this inhibitory effect, thereby promoting platelet secretion and aggregation.
Collapse
|
32
|
Moore SF, Hunter RW, Hers I. Protein kinase C and P2Y12 take center stage in thrombin-mediated activation of mammalian target of rapamycin complex 1 in human platelets. J Thromb Haemost 2014; 12:748-60. [PMID: 24612393 PMCID: PMC4238809 DOI: 10.1111/jth.12552] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 02/25/2014] [Indexed: 01/24/2023]
Abstract
BACKGROUND Rapamycin, an inhibitor of mammalian target of rapamycin complex-1 (mTORC1), reduces platelet spreading, thrombus stability, and clot retraction. Despite an important role of mTORC1 in platelet function, little is known about how it is regulated. The objective of this study was to determine the signaling pathways that regulate mTORC1 in human platelets. METHODS Mammalian target of rapamycin complex-1 activation was assessed by measuring the phosphorylation of its downstream substrate ribosomal S6 kinase 1 (p70S6K). RESULTS Thrombin or the protein kinase C (PKC) activator phorbal 12-myristate 13-acetate stimulated activation of mTORC1 in a PKC-dependent, Akt-independent manner that correlated with phosphorylation of tuberin/tuberous sclerosis 2 (TSC2) (Ser939 and Thr1462). In contrast, insulin-like growth factor 1 (IGF-1)-stimulated TSC2 phosphorylation was completely dependent on phosphoinositide 3 kinase (PI3 kinase)/Akt but did not result in any detectable mTORC1 activation. Early (Ser939 and Thr1462) and late (Thr1462) TSC2 phosphorylation in response to thrombin were directly PKC dependent, whereas later TSC2 (Ser939) and p70S6K phosphorylation were largely dependent on paracrine signaling through P2Y(12). PKC-mediated adenosine diphosphate (ADP) secretion was essential for thrombin-stimulated mTORC1 activation, as (i) ADP rescued p70S6K phosphorylation in the presence of a PKC inhibitor and (ii) P2Y(12) antagonism prevented thrombin-mediated mTORC1 activation. Rescue of mTORC1 activation with exogenous ADP was completely dependent on the Src family kinases but independent of PI3 kinase/Akt. Interestingly, although inhibition of Src blocked the ADP rescue, it had little effect on thrombin-stimulated p70S6K phosphorylation under conditions where PKC was not inhibited. CONCLUSION These results demonstrate that thrombin activates the mTORC1 pathway in human platelets through PKC-mediated ADP secretion and subsequent activation of P2Y(12), in a manner largely independent of the canonical PI3 kinase/Akt pathway.
Collapse
Affiliation(s)
- S F Moore
- School of Physiology and Pharmacology, Medical Sciences Building, University of Bristol, Bristol, UK
| | | | | |
Collapse
|
33
|
Vincent EE, Elder DJE, Curwen J, Kilgour E, Hers I, Tavaré JM. Targeting non-small cell lung cancer cells by dual inhibition of the insulin receptor and the insulin-like growth factor-1 receptor. PLoS One 2013; 8:e66963. [PMID: 23826179 PMCID: PMC3691253 DOI: 10.1371/journal.pone.0066963] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 05/14/2013] [Indexed: 11/18/2022] Open
Abstract
Phase III trials of the anti-insulin-like growth factor-1 receptor (IGF1R) antibody figitumumab in non-small cell lung cancer (NSCLC) patients have been discontinued owing to lack of survival benefit. We investigated whether inhibition of the highly homologous insulin receptor (IR) in addition to the IGF1R would be more effective than inhibition of the IGF1R alone at preventing the proliferation of NSCLC cells. Signalling through IGF1R and IR in the NSCLC cell lines A549 and Hcc193 was stimulated by a combination of IGF1, IGF2 and insulin. It was inhibited by antibodies that block ligand binding, αIR3 (IGF1R) and IR47-9 (IR), and by the ATP-competitive small molecule tyrosine kinase inhibitors AZ12253801 and NVPAWD742 which inhibit both IGF1R and IR tyrosine kinases. The effect of inhibitors was determined by an anchorage-independent proliferation assay and by analysis of Akt phosphorylation. In Hcc193 cells the reduction in cell proliferation and Akt phosphorylation due to anti-IGF1R antibody was enhanced by antibody-mediated inhibition of the IR whereas in A549 cells, with a relatively low IR:IGF1R expression ratio, it was not. In each cell line proliferation and Akt phosphorylation were more effectively inhibited by AZ12253801 and NVPAWD742 than by combined αIR3 and IR47-9. When the IGF1R alone is inhibited, unencumbered signalling through the IR can contribute to continued NSCLC cell proliferation. We conclude that small molecule inhibitors targeting both the IR and IGF1R more effectively reduce NSCLC cell proliferation in a manner independent of the IR:IGF1R expression ratio, providing a therapeutic rationale for the treatment of this disease.
Collapse
Affiliation(s)
- Emma E. Vincent
- School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - Douglas J. E. Elder
- School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - Jon Curwen
- CIRA Discovery, AstraZeneca, Alderley Park, Macclesfield, United Kingdom
| | - Elaine Kilgour
- CIRA Discovery, AstraZeneca, Alderley Park, Macclesfield, United Kingdom
| | - Ingeborg Hers
- School of Physiology and Pharmacology, Medical Sciences Building, University of Bristol, Bristol, United Kingdom
| | - Jeremy M. Tavaré
- School of Biochemistry, Medical Sciences Building, University of Bristol, Bristol, United Kingdom
| |
Collapse
|
34
|
Hale LJ, Welsh GI, Perks CM, Hurcombe JA, Moore S, Hers I, Saleem MA, Mathieson PW, Murphy AJ, Jeansson M, Holly JM, Hardouin SN, Coward RJ. Insulin-like growth factor-II is produced by, signals to and is an important survival factor for the mature podocyte in man and mouse. J Pathol 2013; 230:95-106. [PMID: 23299523 DOI: 10.1002/path.4165] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 12/03/2012] [Accepted: 12/26/2012] [Indexed: 01/10/2023]
Abstract
Podocytes are crucial for preventing the passage of albumin into the urine and, when lost, are associated with the development of albuminuria, renal failure and cardiovascular disease. Podocytes have limited capacity to regenerate, therefore pro-survival mechanisms are critically important. Insulin-like growth factor-II (IGF-II) is a potent survival and growth factor; however, its major function is thought to be in prenatal development, when circulating levels are high. IGF-II has only previously been reported to continue to be expressed in discrete regions of the brain into adulthood in rodents, with systemic levels being undetectable. Using conditionally immortalized human and ex vivo adult mouse cells of the glomerulus, we demonstrated the podocyte to be the major glomerular source and target of IGF-II; it signals to this cell via the IGF-I receptor via the PI3 kinase and MAPK pathways. Functionally, a reduction in IGF signalling causes podocyte cell death in vitro and glomerular disease in vivo in an aged IGF-II transgenic mouse that produces approximately 60% of IGF-II due to a lack of the P2 promoter of this gene. Collectively, this work reveals the fundamental importance of IGF-II in the mature podocyte for glomerular health across mammalian species.
Collapse
Affiliation(s)
- L J Hale
- Academic and Children's Renal Unit, University of Bristol, Learning and Research, Southmead Hospital, Bristol, BS10 5NB, UK
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Savage JS, Williams CM, Konopatskaya O, Hers I, Harper MT, Poole AW. Munc13-4 is critical for thrombosis through regulating release of ADP from platelets. J Thromb Haemost 2013; 11:771-5. [PMID: 23331318 DOI: 10.1111/jth.12138] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 12/20/2012] [Indexed: 01/19/2023]
|
36
|
Abstract
Background The motor protein myosin Va plays an important role in the trafficking of intracellular vesicles. Mutation of the Myo5a gene causes Griscelli syndrome type 1 in humans and the dilute phenotype in mice, which are both characterised by pigment dilution and neurological defects as a result of impaired vesicle transport in melanocytes and neuroendocrine cells. The role of myosin Va in platelets is currently unknown. Rab27 has been shown to be associated with myosin Va cargo vesicles and is known to be important in platelet dense granule biogenesis and secretion, a crucial event in thrombus formation. Therefore, we hypothesised that myosin Va may regulate granule secretion or formation in platelets. Methodology/Principal Findings Platelet function was studied in vitro using a novel Myo5a gene deletion mouse model. Myo5a−/− platelets were devoid of myosin Va, as determined by immunoblotting, and exhibited normal expression of surface markers. We assessed dense granule, α-granule and lysosomal secretion, integrin αIIbβ3 activation, Ca2+ signalling, and spreading on fibrinogen in response to collagen-related peptide or the PAR4 agonist, AYPGKF in washed mouse platelets lacking myosin Va or wild-type platelets. Surprisingly, Myo5a−/− platelets showed no significant functional defects in these responses, or in the numbers of dense and α-granules expressed. Conclusion Despite the importance of myosin Va in vesicle transport in other cells, our data demonstrate this motor protein has no non-redundant role in the secretion of dense and α-granules or other functional responses in platelets.
Collapse
Affiliation(s)
- Matthew T. Harper
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | | | - Ingeborg Hers
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
| | - Alastair W. Poole
- School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom
- * E-mail:
| |
Collapse
|
37
|
Moore SF, van den Bosch MTJ, Hunter RW, Sakamoto K, Poole AW, Hers I. Dual regulation of glycogen synthase kinase 3 (GSK3)α/β by protein kinase C (PKC)α and Akt promotes thrombin-mediated integrin αIIbβ3 activation and granule secretion in platelets. J Biol Chem 2012; 288:3918-28. [PMID: 23239877 PMCID: PMC3567645 DOI: 10.1074/jbc.m112.429936] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Glycogen synthase kinase-3 is a Ser/Thr kinase, tonically active in resting cells but inhibited by phosphorylation of an N-terminal Ser residue (Ser21 in GSK3α and Ser9 in GSK3β) in response to varied external stimuli. Recent work suggests that GSK3 functions as a negative regulator of platelet function, but how GSK3 is regulated in platelets has not been examined in detail. Here, we show that early thrombin-mediated GSK3 phosphorylation (0–30 s) was blocked by PKC inhibitors and largely absent in platelets from PKCα knock-out mice. In contrast, late (2–5 min) GSK3 phosphorylation was dependent on the PI3K/Akt pathway. Similarly, early thrombin-mediated inhibition of GSK3 activity was blocked in PKCα knock-out platelets, whereas the Akt inhibitor MK2206 reduced late thrombin-mediated GSK3 inhibition and largely prevented GSK3 inhibition in PKCα knock-out platelets. More importantly, GSK3 phosphorylation contributes to platelet function as knock-in mice where GSK3α Ser21 and GSK3β Ser9 were mutated to Ala showed a significant reduction in PAR4-mediated platelet aggregation, fibrinogen binding, and P-selectin expression, whereas the GSK3 inhibitor CHIR99021 enhanced these responses. Together, these results demonstrate that PKCα and Akt modulate platelet function by phosphorylating and inhibiting GSK3α/β, thereby relieving the negative effect of GSK3α/β on thrombin-mediated platelet activation.
Collapse
Affiliation(s)
- Samantha F Moore
- School of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom
| | | | | | | | | | | |
Collapse
|
38
|
Moore SF, Hunter RW, Hers I. mTORC2 protein-mediated protein kinase B (Akt) serine 473 phosphorylation is not required for Akt1 activity in human platelets. J Biol Chem 2011. [DOI: 10.1074/jbc.a110.202341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
|
39
|
Moore SF, Hunter RW, Hers I. mTORC2 protein complex-mediated Akt (Protein Kinase B) Serine 473 Phosphorylation is not required for Akt1 activity in human platelets [corrected]. J Biol Chem 2011; 286:24553-60. [PMID: 21592956 PMCID: PMC3137030 DOI: 10.1074/jbc.m110.202341] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Protein kinase B (PKB, Akt) is a Ser/Thr kinase involved in the regulation of cell survival, proliferation, and metabolism and is activated by dual phosphorylation on Thr308 in the activation loop and Ser473 in the hydrophobic motif. It plays a contributory role to platelet function, although little is known about its regulation. In this study, we investigated the role of the mammalian target of rapamycin complex (mTORC)-2 in Akt regulation using the recently identified small molecule ATP competitive mTOR inhibitors PP242 and Torin1. Both PP242 and Torin1 blocked thrombin and insulin-like growth factor 1-mediated Akt Ser473 phosphorylation with an IC50 between 1 and 5 nm, whereas the mTORC1 inhibitor rapamycin had no effect. Interestingly, PP242 and Torin1 had no effect on Akt Thr308 phosphorylation, Akt1 activity, and phosphorylation of the Akt substrate glycogen synthase kinase 3β, indicating that Ser473 phosphorylation is not necessary for Thr308 phosphorylation and maximal Akt1 activity. In contrast, Akt2 activity was significantly reduced, concurrent with inhibition of PRAS40 phosphorylation, in the presence of PP242 and Torin1. Other signaling pathways, including phospholipase C/PKC and the MAPK pathway, were unaffected by PP242 and Torin1. Together, these results demonstrate that mTORC2 is the kinase that phosphorylates Akt Ser473 in human platelets but that this phosphorylation is dispensable for Thr308 phosphorylation and Akt1 activity.
Collapse
Affiliation(s)
- Samantha F Moore
- School of Physiology and Pharmacology, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom
| | | | | |
Collapse
|
40
|
Abstract
Akt (also known as protein kinase B or PKB) comprises three closely related isoforms Akt1, Akt2 and Akt3 (or PKBα/β/γ respectively). We have a very good understanding of the mechanisms by which Akt isoforms are activated by growth factors and other extracellular stimuli as well as by oncogenic mutations in key upstream regulatory proteins including Ras, PI3-kinase subunits and PTEN. There are also an ever increasing number of Akt substrates being identified that play a role in the regulation of the diverse array of biological effects of activated Akt; this includes the regulation of cell proliferation, survival and metabolism. Dysregulation of Akt leads to diseases of major unmet medical need such as cancer, diabetes, cardiovascular and neurological diseases. As a result there has been substantial investment in the development of small molecular Akt inhibitors that act competitively with ATP or phospholipid binding, or allosterically. In this review we will briefly discuss our current understanding of how Akt isoforms are regulated, the substrate proteins they phosphorylate and how this integrates with the role of Akt in disease. We will furthermore discuss the types of Akt inhibitors that have been developed and are in clinical trials for human cancer, as well as speculate on potential on-target toxicities, such as disturbances of heart and vascular function, metabolism, memory and mood, which should be monitored very carefully during clinical trial.
Collapse
Affiliation(s)
- Ingeborg Hers
- School of Physiology and Pharmacology, University of Bristol, UK
| | | | | |
Collapse
|
41
|
Abstract
OBJECTIVES As platelets express both insulin and insulin-like growth factor-1 (IGF-1) receptors, their subunits may randomly heterodimerize to form insulin/IGF-1 receptor hybrids, which avidly bind IGF-1, but not insulin. This study investigated the possibility that platelets express hybrid receptors, which may affect insulin action on platelet function. METHODS Platelets were incubated with insulin and IGF-1. Expression and phosphorylation of insulin/IGF-1 receptors was determined by western blotting of immunoprecipitates, and compared with platelet functional responses. Relative expression of insulin and IGF-1 receptors was estimated by competitive ligand binding and quantitative polymerase chain reaction. RESULTS We demonstrated the presence of insulin/IGF-1 hybrid receptors on human platelets by detecting both insulin and IGF-1 receptor beta subunits in coimmunoprecipitation studies. Stimulation of platelets with insulin (1-100 nm) resulted in tyrosine phosphorylation of insulin receptors, but not of hybrid receptors. High insulin concentrations (50-100 nm) stimulated weak phosphorylation of IGF-1 receptors and protein kinase B (Akt), and correlated with moderately increased aggregation and fibrinogen binding, whereas low insulin concentrations (1-10 nm) had no effect. In contrast, IGF-1 (1-100 nm) induced strong phosphorylation of both hybrid and IGF-1 receptors, and potentiated platelet aggregation and fibrinogen binding. Specific binding of [(125)I]IGF-1 (1.08% +/- 0.16%) was significantly higher than that of [(125)I]insulin (0.15% +/- 0.03%). Accordingly, IGF-1 receptor mRNA was more abundant than insulin receptor mRNA (IGF-1 receptor/insulin receptor ratio 69 +/- 3.8). CONCLUSIONS Insulin has minimal effects on platelet function, which can be explained by the relatively low insulin receptor expression levels resulting in the majority of insulin receptor subunits being expressed as insulin/IGF-1 hybrids.
Collapse
Affiliation(s)
- R W Hunter
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol, UK
| | | |
Collapse
|
42
|
Hunter RW, Mackintosh C, Hers I. Protein kinase C-mediated phosphorylation and activation of PDE3A regulate cAMP levels in human platelets. J Biol Chem 2009; 284:12339-48. [PMID: 19261611 DOI: 10.1074/jbc.m807536200] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The elevation of [cAMP](i) is an important mechanism of platelet inhibition and is regulated by the opposing activity of adenylyl cyclase and phosphodiesterase (PDE). In this study, we demonstrate that a variety of platelet agonists, including thrombin, significantly enhance the activity of PDE3A in a phosphorylation-dependent manner. Stimulation of platelets with the PAR-1 agonist SFLLRN resulted in rapid and transient phosphorylation of PDE3A on Ser(312), Ser(428), Ser(438), Ser(465), and Ser(492), in parallel with the PKC (protein kinase C) substrate, pleckstrin. Furthermore, phosphorylation and activation of PDE3A required the activation of PKC, but not of PI3K/PKB, mTOR/p70S6K, or ERK/RSK. Activation of PKC by phorbol esters also resulted in phosphorylation of the same PDE3A sites in a PKC-dependent, PKB-independent manner. This was further supported by the finding that IGF-1, which strongly activates PI3K/PKB, but not PKC, did not regulate PDE3A. Platelet activation also led to a PKC-dependent association between PDE3A and 14-3-3 proteins. In contrast, cAMP-elevating agents such as PGE(1) and forskolin-induced phosphorylation of Ser(312) and increased PDE3A activity, but did not stimulate 14-3-3 binding. Finally, complete antagonism of PGE(1)-evoked cAMP accumulation by thrombin required both G(i) and PKC activation. Together, these results demonstrate that platelet activation stimulates PKC-dependent phosphorylation of PDE3A on Ser(312), Ser(428), Ser(438), Ser(465), and Ser(492) leading to a subsequent increase in cAMP hydrolysis and 14-3-3 binding.
Collapse
Affiliation(s)
- Roger W Hunter
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, UK
| | | | | |
Collapse
|
43
|
Abstract
Recombinant factor VIIa (rFVIIa) is a pro-haemostatic agent that is effective in the treatment of bleeding in haemophilia complicated by inhibitors and some other haemorrhagic disorders. The rFVIIa product promotes haemostasis in these settings by enabling the rapid generation of thrombin on the surface of activated platelets which increases fibrin deposition. rFVIIa also has therapeutic activity in bleeding in platelet function disorders such as Glanzmann's thrombasthenia and thrombocytopenia. This suggests that rFVIIa also has a pro-haemostatic effect on platelets and this may contribute to the overall therapeutic action of this agent. The effects of high-concentration FVIIa on platelets have been studied in detail in experiments using ex vivo model systems of haemostasis under static and flow conditions. These experiments show that FVIIa potentiates multiple functional markers of platelet activation and this effect requires direct binding of FVIIa to the activated platelet membrane and the generation of thrombin. The mechanism of this potentiating effect of FVIIa on platelet activation is complex and is likely to require multiple platelet activation receptors and signalling pathways. These include the GPIb-IX-V glycoprotein complex and the thrombin protease activated receptors. The proposed mechanism of action of high-concentration FVIIa has important implications for the therapeutic activity of rFVIIa in vivo. This review summarizes the clinical and experimental evidence supporting a potentiating effect of FVIIa on platelet activation and discusses the likely mechanism of action.
Collapse
Affiliation(s)
- Ingeborg Hers
- Department of Biochemistry, School of Medical Sciences, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | | |
Collapse
|
44
|
Abstract
BACKGROUND The role of PKB in platelet function is poorly defined due to the lack of genuinely selective small-molecule inhibitors and limiting genetic models. Recently, a selective, non-ATP-competitive PKB inhibitor, Akti-1/2 has been reported, but the efficacy and specificity against PKB activation in platelet function is unknown. OBJECTIVE AND METHODS To determine the effect of the PKB inhibitor Akti-1/2 on PKB activation and platelet function by Western blotting and aggregometry/flow cytometry, respectively. RESULTS Akti-1/2 potently inhibited thrombin-mediated PKB phosphorylation on Thr(308) and Ser(473) and phosphorylation of its downstream substrate GSK3beta, with a negligible effect on the phosphorylation of pleckstrin, p38, ERK and JNK. Surprisingly, Akti-1/2 strongly potentiated PAR-1-mediated platelet aggregation. This effect persisted in the presence of PI3 kinase inhibitors, indicating a mechanism of action that is independent of PKB. Potentiation of aggregation by Akti-1/2 was associated with increased [Ca(++)](i), PKC activation and degranulation and was ablated by agents that antagonized this pathway. CONCLUSIONS The PKB inhibitor Akti-1/2 increases PAR-1-mediated platelet responses in a PKB-independent, Ca(++)/PKC-dependent manner. This effect is strong and rapid and may impact on the therapeutic application of Akti-1/2 and structurally related compounds.
Collapse
Affiliation(s)
- R W Hunter
- Department of Biochemistry, School of Medicine Sciences, University of Bristol, Bristol, UK
| | | | | |
Collapse
|
45
|
Abstract
As insulin-like growth factor-1 (IGF-1) is present in the α granules of platelets and its receptor is expressed on the platelet surface, it may contribute to the amplification of platelet responses and pathogenesis of cardiovascular disease. The functional and signaling pathways that are involved in IGF-1 modulation of platelet function, however, are presently unknown. Here, I report that IGF-1 stimulation of platelets results in dose-dependent phosphorylation of the IGF receptor in the range of 1 to 100 nM. Phosphorylation of the IGF receptor is rapid and sustained, with maximal phosphorylation reached within 1 minute. Furthermore, IGF-1 stimulates tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) and IRS-2 and their association with the p85 subunit of phosphoinositide-3 kinase (PI3K). IGF-1–stimulated tyrosine phosphorylation of IRS-1 and IRS-2 and subsequent p85 binding is transient and precedes phosphorylation of protein kinase B (PKB) on Ser473. PAR-1–mediated platelet aggregation is potentiated by IGF-1 and this potentiation, together with PKB phosphorylation, is abolished by the PI3Kα inhibitors PI-103 and PIK-75. Importantly, the IGF receptor inhibitor NVP-AEW541 and the neutralization antibody αIR3 inhibit SFLLRN-stimulated aggregation, implicating IGF-1 in autocrine regulation of platelet function. These results demonstrate that IGF-1 activates the IGF receptor/IRS/PI3K/PKB pathway, and that PI3Kα is essential for the potentiatory effect of IGF-1 on platelet responses.
Collapse
Affiliation(s)
- Ingeborg Hers
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol, UK.
| |
Collapse
|
46
|
Hunter R, Harthill J, MacKintosh C, Hers I. REGULATION OF PHOSPHODIESTERASE 3A IN HUMAN PLATELETS IS MEDIATED BY PROTEIN KINASE C. J Thromb Haemost 2007. [DOI: 10.1111/j.1538-7836.2007.tb02014.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
47
|
Abstract
Several members of the extensive family of small GTP-binding proteins are regulated by insulin, and have been implicated in insulin action on glucose uptake. These proteins are themselves negatively regulated by a series of specific GAPs (GTPase-activating proteins). Interestingly, there is increasing evidence to suggest that PKB (protein kinase B)-dependent phosphorylation of some GAPs may relieve this negative regulation and so lead to the activation of the target small GTP-binding protein. We review recent evidence that this may be the case, and place specific emphasis on the role of these pathways in insulin-stimulated glucose uptake.
Collapse
Affiliation(s)
- G I Welsh
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 ITD, UK
| | | | | | | |
Collapse
|
48
|
Hers I, Wherlock M, Homma Y, Yagisawa H, Tavaré JM. Identification of p122RhoGAP (deleted in liver cancer-1) Serine 322 as a substrate for protein kinase B and ribosomal S6 kinase in insulin-stimulated cells. J Biol Chem 2005; 281:4762-70. [PMID: 16338927 DOI: 10.1074/jbc.m511008200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Protein kinase B (PKB or Akt) plays an essential role in the actions of insulin, cytokines, and growth factors, although the substrates for PKB that are relevant to many of its actions require identification. In this study, we have reported the identification of p122RhoGAP, a GTPase-activating protein selective for RhoA and rodent homologue of the tumor suppressor deleted in liver cancer (DLC1) as a novel insulin-stimulated phosphoprotein in primary rat adipocytes. We have demonstrated that Ser-322 is phosphorylated upon insulin stimulation of intact cells and that this site is directly phosphorylated in vitro by PKB and ribosomal S6 kinase, members of the AGC (protein kinases A, G, and C) family of insulin-stimulated protein kinases. Furthermore, expression of constitutively active mutants of PKB or mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK) stimulates Ser-322 phosphorylation in intact cells, demonstrating that activation of the PKB or MEK pathway is sufficient for Ser-322 phosphorylation in vivo. Indeed, in primary adipocytes, insulin-stimulated Ser-322 phosphorylation was almost exclusively regulated by the phosphatidylinositol 3-kinase/PKB pathway, whereas in immortalized cells, insulin-stimulated phosphorylation was predominantly regulated by the MEK/extracellular signal-regulated kinase/ribosomal S6 kinase pathway, with the phosphatidylinositol 3-kinase/PKB pathway playing a minor role. These results demonstrate that p122RhoGAP Ser-322 acts as an integrator of signal transduction in a manner dependent on the cellular context.
Collapse
Affiliation(s)
- Ingeborg Hers
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom.
| | | | | | | | | |
Collapse
|
49
|
Abstract
Serine and threonine phosphorylation of IRS-1 (insulin receptor substrate-1) has been reported to decrease its ability to be tyrosine-phosphorylated by the insulin receptor. Insulin itself may negatively regulate tyrosine phosphorylation of IRS-1 through a PI3K (phosphoinositide 3-kinase)-dependent feedback pathway. In the present study, we examined the regulation and role of IRS-1 serine phosphorylation in the modulation of IRS-1 tyrosine phosphorylation in physiologically relevant cells, namely freshly isolated primary adipocytes. We show that insulin-stimulated phosphorylation of Ser312 and Ser616 in IRS-1 was relatively slow, with maximal phosphorylation achieved after 20 and 5 min respectively. The effect of insulin on phosphorylation of both these sites required the activation of PI3K and the MAPKs (mitogen-activated protein kinases) ERK1/2 (extracellular-signal-regulated kinase 1 and 2), but not the activation of mTOR (mammalian target of rapamycin)/p70S6 kinase, JNK (c-Jun N-terminal kinase) or p38MAPK. Although inhibition of PI3K and ERK1/2 both substantially decreased insulin-stimulated phosphorylation of Ser312 and Ser616, only wortmannin enhanced insulin-stimulated tyrosine phosphorylation of IRS-1. Furthermore, inhibition of mTOR/p70S6 kinase, JNK or p38MAPK had no effect on insulin-stimulated IRS-1 tyrosine phosphorylation. The differential effect of inhibition of ERK1/2 on insulin-stimulated IRS-1 phosphorylation of Ser312/Ser616 and tyrosine indicates that these events are independent of each other and that phosphorylation of Ser312/Ser616 is not responsible for the negative regulation of IRS-1 tyrosine phosphorylation mediated by PI3K in primary adipocytes.
Collapse
Affiliation(s)
- Ingeborg Hers
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, UK.
| | | |
Collapse
|
50
|
Welsh GI, Hers I, Berwick DC, Dell G, Wherlock M, Birkin R, Leney S, Tavaré JM. Role of protein kinase B in insulin-regulated glucose uptake. Biochem Soc Trans 2005; 33:346-9. [PMID: 15787603 DOI: 10.1042/bst0330346] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The activation of protein kinase B (or Akt) plays a central role in the stimulation of glucose uptake by insulin. Currently, however, numerous questions remain unanswered regarding the role of this kinase in bringing about this effect. For example, we do not know precisely where in the GLUT4 trafficking pathway this kinase acts. Nor do we know which protein substrates are responsible for mediating the effects of protein kinase B, although two recently identified proteins (AS160 and PIKfyve) may play a role. This paper addresses these important questions by reviewing recent progress in the field.
Collapse
Affiliation(s)
- G I Welsh
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 ITD, UK
| | | | | | | | | | | | | | | |
Collapse
|