551
|
Platelets in Systemic Sclerosis: the Missing Link Connecting Vasculopathy, Autoimmunity, and Fibrosis? Curr Rheumatol Rep 2019; 21:15. [PMID: 30830444 DOI: 10.1007/s11926-019-0815-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE OF REVIEW Platelets are no longer recognized solely as cell fragments regulating hemostasis. They have pleiotropic functions and they are linked directly or indirectly with the three cornerstones of systemic sclerosis (SSc): vasculopathy, autoimmunity, and fibrosis. In this review, we summarize the current knowledge on the potential role of platelets in the pathogenesis of SSc. RECENT FINDINGS Experimental evidence suggests that vasculopathy, a universal and early finding in SSc, may activate platelets which subsequently release several profibrotic mediators such as serotonin and transforming growth factor β (TGFβ). Platelets may also cross-react with the endothelium leading to the release of molecules, such as thymic stromal lymphopoietin (TSLP), that may trigger fibrosis or sustain vascular damage. Finally, activated platelets express CD40L and provide costimulatory help to B cells, something that may facilitate the breach in immune tolerance. Preclinical studies point to the direction that platelets are actively involved in SSc pathogenesis. Targeting platelets may be an attractive therapeutic approach in SSc.
Collapse
|
552
|
Johnsen N, Hamilton ADM, Greve AS, Christensen MG, Therkildsen JR, Wehmöller J, Skals M, Praetorius HA. α-Haemolysin production, as a single factor, causes fulminant sepsis in a model of Escherichia coli-induced bacteraemia. Cell Microbiol 2019; 21:e13017. [PMID: 30761726 DOI: 10.1111/cmi.13017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 02/08/2019] [Accepted: 02/10/2019] [Indexed: 12/14/2022]
Abstract
α-Haemolysin (HlyA) from uropathogenic Escherichia coli has been demonstrated to be a significant virulence factor for ascending urinary tract infections. Once the E. coli reach the well-vascularised kidneys, there is a high risk of bacteraemia and a subsequent septic host response. Despite this, HlyA has the potential to accelerate the host response both directly and via its ability to facilitate adenosine triphosphate release from cells. It has not been settled whether HlyA aggravates bacteraemia into a septic state. To address this, we used an E. coli strain in a model of acute urosepsis that was either transfected with a plasmid containing the full HlyA operon or one with deletion in the HlyA gene. Here, we show that HlyA accelerates the host response to E. coli in the circulation. Mice exposed to HlyA-producing E. coli showed massively increased proinflammatory cytokines, a substantial fall in circulating thrombocytes, extensive haematuria, and intravascular haemolysis. This was not seen in mice exposed to either E. coli that do not secrete HlyA or vehicle controls. Consistent with the massive host response to the bacteria, the mice exposed to HlyA-producing E. coli died exceedingly early, whereas mice exposed to E. coli without HlyA production and vehicle controls survived the entire observation period. These data allow us to conclude that HlyA is a virulence factor that accelerates a state of bacteraemia into fulminant sepsis in a mouse model.
Collapse
Affiliation(s)
- Nanna Johnsen
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | | | | | | | | | - Julia Wehmöller
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | - Marianne Skals
- Department of Biomedicine, Aarhus University, Aarhus C, Denmark
| | | |
Collapse
|
553
|
Bresnick AR, Backer JM. PI3Kβ-A Versatile Transducer for GPCR, RTK, and Small GTPase Signaling. Endocrinology 2019; 160:536-555. [PMID: 30601996 PMCID: PMC6375709 DOI: 10.1210/en.2018-00843] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 12/20/2018] [Indexed: 12/17/2022]
Abstract
The phosphoinositide 3-kinase (PI3K) family includes eight distinct catalytic subunits and seven regulatory subunits. Only two PI3Ks are directly regulated downstream from G protein-coupled receptors (GPCRs): the class I enzymes PI3Kβ and PI3Kγ. Both enzymes produce phosphatidylinositol 3,4,5-trisposphate in vivo and are regulated by both heterotrimeric G proteins and small GTPases from the Ras or Rho families. However, PI3Kβ is also regulated by direct interactions with receptor tyrosine kinases (RTKs) and their tyrosine phosphorylated substrates, and similar to the class II and III PI3Ks, it binds activated Rab5. The unusually complex regulation of PI3Kβ by small and trimeric G proteins and RTKs leads to a rich landscape of signaling responses at the cellular and organismic levels. This review focuses first on the regulation of PI3Kβ activity in vitro and in cells, and then summarizes the biology of PI3Kβ signaling in distinct tissues and in human disease.
Collapse
Affiliation(s)
- Anne R Bresnick
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
| | - Jonathan M Backer
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York
| |
Collapse
|
554
|
Miliotis S, Nicolalde B, Ortega M, Yepez J, Caicedo A. Forms of extracellular mitochondria and their impact in health. Mitochondrion 2019; 48:16-30. [PMID: 30771504 DOI: 10.1016/j.mito.2019.02.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Revised: 11/09/2018] [Accepted: 02/06/2019] [Indexed: 12/15/2022]
Abstract
Mitochondria play an important role as an intracellular energy plant and signaling organelle. However, mitochondria also exist outside cells where they could mediate cell-to-cell communication, repair and serve as an activator of the immune response. Their effects depend on the mitochondrial state or the form in which it is present, either as a whole functional structure as fragments or only as mitochondrial DNA. Herein, we provide evidence of why extracellular mitochondria and their varying forms are considered regenerative factors or pro-inflammatory activators. Understanding these aspects will provide the base of their use in therapy or as a biomarker of disease severity and prognosis.
Collapse
Affiliation(s)
- Sophia Miliotis
- Universidad San Francisco de Quito, The Latitude Zero Ecuador Research Initiative, L0ERI, 17-12-841, Ecuador
| | - Bryan Nicolalde
- Universidad San Francisco de Quito, Colegio de Ciencias de la Salud - Hospital de los Valles, Escuela de Medicina, Quito 17-12-841, Ecuador
| | - Mayra Ortega
- Universidad San Francisco de Quito, Colegio de Ciencias Biológicas y Ambientales, Escuela de Biotecnología, Quito 17-12-841, Ecuador; Universidad San Francisco de Quito, Instituto de Investigaciones en Biomedicina, Quito 17-12-841, Ecuador
| | - Jackie Yepez
- Universidad San Francisco de Quito, The Latitude Zero Ecuador Research Initiative, L0ERI, 17-12-841, Ecuador
| | - Andrés Caicedo
- Universidad San Francisco de Quito, Colegio de Ciencias de la Salud - Hospital de los Valles, Escuela de Medicina, Quito 17-12-841, Ecuador; Universidad San Francisco de Quito, Instituto de Investigaciones en Biomedicina, Quito 17-12-841, Ecuador; Mito-Act Research Consortium, Quito, Ecuador; Sistemas Médicos - Universidad San Francisco de Quito, SIME-USFQ, Quito 17-12-841, Ecuador.
| |
Collapse
|
555
|
Cunin P, Nigrovic PA. Megakaryocytes as immune cells. J Leukoc Biol 2019; 105:1111-1121. [PMID: 30645026 DOI: 10.1002/jlb.mr0718-261rr] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/26/2018] [Accepted: 11/26/2018] [Indexed: 12/19/2022] Open
Abstract
Platelets play well-recognized roles in inflammation, but their cell of origin-the megakaryocyte-is not typically considered an immune lineage. Megakaryocytes are large polyploid cells most commonly identified in bone marrow. Egress via sinusoids enables migration to the pulmonary capillary bed, where elaboration of platelets can continue. Beyond receptors involved in hemostasis and thrombosis, megakaryocytes express receptors that confer immune sensing capacity, including TLRs and Fc-γ receptors. They control the proliferation of hematopoietic cells, facilitate neutrophil egress from marrow, possess the capacity to cross-present antigen, and can promote systemic inflammation through microparticles rich in IL-1. Megakaryocytes internalize other hematopoietic lineages, especially neutrophils, in an intriguing cell-in-cell interaction termed emperipolesis. Together, these observations implicate megakaryocytes as direct participants in inflammation and immunity.
Collapse
Affiliation(s)
- Pierre Cunin
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Peter A Nigrovic
- Department of Medicine, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Department of Medicine, Division of Immunology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
556
|
Heffron SP, Marier C, Parikh M, Fisher EA, Berger JS. Severe obesity and bariatric surgery alter the platelet mRNA profile. Platelets 2019; 30:967-974. [PMID: 30388921 PMCID: PMC6642854 DOI: 10.1080/09537104.2018.1536261] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mechanisms explaining the relationship between obesity and cardiovascular disease (CVD) are needed. Despite growing recognition of the importance of the anucleate platelet transcriptome, low levels of RNA in platelets make assessment difficult. We sought to perform unbiased platelet RNA profiling in obesity by performing a prospective study of severe obesity and weight loss via bariatric surgery on platelet characteristics and mRNA profile in 26 pre-menopausal, non-diabetic women (31.6 ± 8.4 years; BMI 43.0 ± 6.5 kg/m2) who underwent sleeve gastrectomy. Totally, 10 women of similar age with normal BMI served as controls. Platelet activation via flow cytometry was assessed before and after surgery. RNA-sequencing (RNAseq) was performed on platelet isolates from a subset of 13 subjects (eight obese women and five normal-BMI subjects). Platelet count, size, and age did not differ between control and obese women. However, platelet surface P-selectin and CD40 were higher in obesity. RNAseq demonstrated 629 differentially abundant transcripts in obesity. Notably, S100A9 and AGER, established markers of cardiovascular risk, were two of the most highly upregulated transcripts (each > 2.5 fold). At 6 months post-operatively, subjects lost 26.1 ± 5.8% body weight and inducible platelet P-selectin expression was reduced. Expression of 170 transcripts was affected by surgery, but only a small fraction (46/629) were genes found altered in obesity. We demonstrate that obesity is associated with an altered platelet transcriptome and increased platelet activation, which is partly attenuated by bariatric surgery. These observations suggest that platelets may contribute to increased cardiovascular risk in obesity through a variety of mechanisms.
Collapse
Affiliation(s)
- Sean P Heffron
- Department of Medicine, Leon H. Charney Division of Cardiology and the Center for the Prevention of Cardiovascular Disease;,Address for Correspondence: Sean P. Heffron MD, MS, MSc, Instructor in Medicine, Leon H. Charney Division of Cardiology, New York University School of Medicine, 227 East 30th St., #834, New York, NY 10016, Tel: -1- 646-501-2735,
| | - Christian Marier
- Genome Technology Core Laboratory, New York University School of Medicine, New York, NY
| | - Manish Parikh
- Department of Surgery, New York University Langone Medical Center
| | - Edward A Fisher
- Department of Medicine, Leon H. Charney Division of Cardiology and the Center for the Prevention of Cardiovascular Disease
| | - Jeffrey S Berger
- Department of Medicine, Leon H. Charney Division of Cardiology and the Center for the Prevention of Cardiovascular Disease;,Department of Surgery, Division of Vascular Surgery, New York University Langone Medical Center
| |
Collapse
|
557
|
Posma JJ, Grover SP, Hisada Y, Owens AP, Antoniak S, Spronk HM, Mackman N. Roles of Coagulation Proteases and PARs (Protease-Activated Receptors) in Mouse Models of Inflammatory Diseases. Arterioscler Thromb Vasc Biol 2019; 39:13-24. [PMID: 30580574 PMCID: PMC6310042 DOI: 10.1161/atvbaha.118.311655] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 10/19/2018] [Indexed: 12/20/2022]
Abstract
Activation of the blood coagulation cascade leads to fibrin deposition and platelet activation that are required for hemostasis. However, aberrant activation of coagulation can lead to thrombosis. Thrombi can cause tissue ischemia, and fibrin degradation products and activated platelets can enhance inflammation. In addition, coagulation proteases activate cells by cleavage of PARs (protease-activated receptors), including PAR1 and PAR2. Direct oral anticoagulants have recently been developed to specifically inhibit the coagulation proteases FXa (factor Xa) and thrombin. Administration of these inhibitors to wild-type mice can be used to determine the roles of FXa and thrombin in different inflammatory diseases. These results can be compared with the phenotypes of mice with deficiencies of either Par1 (F2r) or Par2 (F2rl1). However, inhibition of coagulation proteases will have effects beyond reducing PAR signaling, and a deficiency of PARs will abolish signaling from all proteases that activate these receptors. We will summarize studies that examine the roles of coagulation proteases, particularly FXa and thrombin, and PARs in different mouse models of inflammatory disease. Targeting FXa and thrombin or PARs may reduce inflammatory diseases in humans.
Collapse
Affiliation(s)
- Jens J Posma
- Laboratory for Clinical Thrombosis and Hemostasis, Departments of Internal Medicine and Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Steven P Grover
- Thrombosis and Hemostasis Program, Division of Hematology and Oncology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Yohei Hisada
- Thrombosis and Hemostasis Program, Division of Hematology and Oncology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - A. Phillip Owens
- Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, OH, USA
| | - Silvio Antoniak
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Henri M Spronk
- Laboratory for Clinical Thrombosis and Hemostasis, Departments of Internal Medicine and Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Nigel Mackman
- Thrombosis and Hemostasis Program, Division of Hematology and Oncology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| |
Collapse
|
558
|
|
559
|
Holinstat M. New LINE(s) of Evidence for Genetic Regulation of Platelets. Arterioscler Thromb Vasc Biol 2018; 38:690-691. [PMID: 29563112 DOI: 10.1161/atvbaha.118.310690] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Michael Holinstat
- From the Department of Pharmacology, University of Michigan, Ann Arbor.
| |
Collapse
|
560
|
Schattner M. Platelet TLR4 at the crossroads of thrombosis and the innate immune response. J Leukoc Biol 2018; 105:873-880. [DOI: 10.1002/jlb.mr0618-213r] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 11/02/2018] [Accepted: 11/19/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Mirta Schattner
- Laboratory of Experimental ThrombosisInstitute of Experimental Medicine (IMEX‐CONICET‐National Academy of Medicine) Buenos Aires Argentina
| |
Collapse
|
561
|
Store-operated calcium entry in thrombosis and thrombo-inflammation. Cell Calcium 2018; 77:39-48. [PMID: 30530092 DOI: 10.1016/j.ceca.2018.11.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 10/31/2018] [Accepted: 11/14/2018] [Indexed: 01/03/2023]
Abstract
Cytosolic free calcium (Ca2+) is a second messenger regulating a wide variety of functions in blood cells, including adhesion, activation, proliferation and migration. Store-operated Ca2+ entry (SOCE), triggered by depletion of Ca2+ from the endoplasmic reticulum, provides a main mechanism of regulated Ca2+ influx in blood cells. SOCE is mediated and regulated by isoforms of the ion channel proteins ORAI and TRP, and the transmembrane Ca2+ sensors stromal interaction molecules (STIMs), respectively. This report provides an overview of the (patho)physiological importance of SOCE in blood cells implicated in thrombosis and thrombo-inflammation, i.e. platelets and immune cells. We also discuss the physiological consequences of dysregulated SOCE in platelets and immune cells and the potential of SOCE inhibition as a therapeutic option to prevent or treat arterial thrombosis as well as thrombo-inflammatory disease states such as ischemic stroke.
Collapse
|
562
|
Eisinger F, Patzelt J, Langer HF. The Platelet Response to Tissue Injury. Front Med (Lausanne) 2018; 5:317. [PMID: 30483508 PMCID: PMC6242949 DOI: 10.3389/fmed.2018.00317] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 10/23/2018] [Indexed: 12/16/2022] Open
Abstract
In recent years, various studies have increasingly explained platelet functions not only in their central role as a regulator in cellular hemostasis and coagulation. In fact, there is growing evidence that under specific conditions, platelets act as a mediator between the vascular system, hemostasis, and the immune system. Therefore, they are essential in many processes involved in tissue remodeling and tissue reorganization after injury or inflammatory responses. These processes include the promotion of inflammatory processes, the contribution to innate and adaptive immune responses during bacterial and viral infections, the modulation of angiogenesis, and the regulation of cell apoptosis in steady-state tissue homeostasis or after tissue breakdown. All in all platelets may contribute to the control of tissue homeostasis much more than generally assumed. This review summarizes the current knowledge of platelets as part of the tissue remodeling network and seeks to provide possible translational implications for clinical therapy.
Collapse
Affiliation(s)
- Felix Eisinger
- Section for Cardioimmunology, Department of Cardiovascular Medicine, University of Tuebingen, Tübingen, Germany
| | - Johannes Patzelt
- University Clinic for Cardiovascular Medicine, University of Tuebingen, Tübingen, Germany
| | - Harald F. Langer
- Section for Cardioimmunology, Department of Cardiovascular Medicine, University of Tuebingen, Tübingen, Germany
- University Clinic for Cardiovascular Medicine, University of Tuebingen, Tübingen, Germany
| |
Collapse
|
563
|
Transfused platelets enhance alloimmune responses to transfused KEL-expressing red blood cells in a murine model. BLOOD TRANSFUSION = TRASFUSIONE DEL SANGUE 2018; 17:368-377. [PMID: 30418129 DOI: 10.2450/2018.0178-18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/17/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Factors influencing the development of alloantibodies against blood group antigens on transfused red blood cells are poorly defined. We hypothesised that transfused platelets may act as a danger signal to recipients and affect humoral immune responses to transfused red blood cells. MATERIALS AND METHODS Platelet-rich plasma prepared from wild-type C57BL/6 or CD40L knock-out donors was transfused into wild-type or CD40L knock-out recipients. Leucoreduced red blood cells from transgenic donors expressing high levels of the human KEL glycoprotein in an erythrocyte-specific manner (KELhi donors) were transfused after the platelets, and anti-KEL responses were measured longitudinally. In some experiments, recipients were treated with poly (I:C), monoclonal CD40L-blocking antibody, or CD4-depleting antibody prior to transfusion. RESULTS Transfusion of wild-type C57BL/6 platelets or treatment with poly (I:C) prior to KELhi red blood cell transfusion led to an anti-KEL alloimmune response in wild-type recipients. Transfusion of platelets from wild-type but not CD40L knock-out donors prior to KELhi red blood cell transfusion led to an IgG anti-KEL alloimmune response in CD40L knock-out recipients; unexpectedly, transfusion of platelets from CD40L knock-out donors prior to KELhi red blood cell transfusion led to a robust anti-KEL alloimmune response in wild-type recipients. Recipient treatment with MR1 CD40L-blocking antibody or CD4-depleting antibody prevented KEL alloimmunisation altogether. DISCUSSION Transfused platelets serve as an adjuvant in this T-dependent murine model of anti-KEL red blood cell alloimmunisation, with CD40/CD40L interactions being involved to some degree but with additional mechanisms also playing a role. These findings raise questions about the role that transfused or endogenous platelets may play in other innate/adaptive immune responses.
Collapse
|
564
|
|
565
|
Fisher MH, Di Paola J. Genomics and transcriptomics of megakaryocytes and platelets: Implications for health and disease. Res Pract Thromb Haemost 2018; 2:630-639. [PMID: 30349880 PMCID: PMC6178711 DOI: 10.1002/rth2.12129] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 06/03/2018] [Indexed: 01/07/2023] Open
Abstract
The field of megakaryocyte and platelet biology has been transformed with the implementation of high throughput sequencing. The use of modern sequencing technologies has led to the discovery of causative mutations in congenital platelet disorders and has been a useful tool in uncovering many other mechanisms of altered platelet formation and function. Although the understanding of the presence of RNA in platelets is relatively novel, mRNA and miRNA expression profiles are being shown to play an increasingly important role in megakaryopoiesis and platelet function in normal physiology as well as in disease states. Understanding the genetic perturbations underlying platelet dysfunction provides insight into normal megakaryopoiesis and thrombopoiesis, as well as guiding the development of novel therapeutics.
Collapse
Affiliation(s)
- Marlie H. Fisher
- Department of PediatricsUniversity of Colorado School of MedicineAuroraColorado
- Medical Scientist Training ProgramUniversity of Colorado School of MedicineAuroraColorado
| | - Jorge Di Paola
- Department of PediatricsUniversity of Colorado School of MedicineAuroraColorado
- Medical Scientist Training ProgramUniversity of Colorado School of MedicineAuroraColorado
| |
Collapse
|
566
|
Yin P, Wei Y, Wang X, Zhu M, Feng J. Roles of Specialized Pro-Resolving Lipid Mediators in Cerebral Ischemia Reperfusion Injury. Front Neurol 2018; 9:617. [PMID: 30131754 PMCID: PMC6090140 DOI: 10.3389/fneur.2018.00617] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 07/10/2018] [Indexed: 12/14/2022] Open
Abstract
Ischemic stroke contributes to ~80% of all stroke cases. Recanalization with thrombolysis or endovascular thrombectomy are currently critical therapeutic strategies for rebuilding the blood supply following ischemic stroke. However, recanalization is often accompanied by cerebral ischemia reperfusion injury that is mediated by oxidative stress and inflammation. Resolution of inflammation belongs to the end stage of inflammation where inflammation is terminated and the repair of damaged tissue is started. Resolution of inflammation is mediated by a group of newly discovered lipid mediators called specialized pro-resolving lipid mediators (SPMs). Accumulating evidence suggests that SPMs decrease leukocyte infiltration, enhance efferocytosis, reduce local neuronal injury, and decrease both oxidative stress and the production of inflammatory cytokines in various in vitro and in vivo models of ischemic stroke. In this review, we summarize the mechanisms of reperfusion injury and the various roles of SPMs in stroke therapy.
Collapse
Affiliation(s)
- Ping Yin
- Department of Neurology and Neuroscience Center, First Hospital of Jilin University, Changchun, China.,First Department of Neurology and Neuroscience Center, Heilongjiang Provincial Hospital, Harbin, China
| | - Yafen Wei
- First Department of Neurology and Neuroscience Center, Heilongjiang Provincial Hospital, Harbin, China
| | - Xu Wang
- Department of Neurology and Neuroscience Center, First Hospital of Jilin University, Changchun, China
| | - Mingqin Zhu
- Department of Neurology and Neuroscience Center, First Hospital of Jilin University, Changchun, China
| | - Jiachun Feng
- Department of Neurology and Neuroscience Center, First Hospital of Jilin University, Changchun, China
| |
Collapse
|
567
|
Parsons MEM, Szklanna PB, Guerrero JA, Wynne K, Dervin F, O'Connell K, Allen S, Egan K, Bennett C, McGuigan C, Gheveart C, Ní Áinle F, Maguire PB. Platelet Releasate Proteome Profiling Reveals a Core Set of Proteins with Low Variance between Healthy Adults. Proteomics 2018; 18:e1800219. [PMID: 29932309 DOI: 10.1002/pmic.201800219] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/09/2018] [Indexed: 12/18/2022]
Abstract
Upon activation, platelets release a powerful cocktail of soluble and vesicular signals, collectively termed the "platelet releasate" (PR). Although several studies have used qualitative/quantitative proteomic approaches to characterize PR; with debated content and significant inter-individual variability reported, confident, and reliable insights have been hindered. Using label-free quantitative (LFQ)-proteomics analysis, a reproducible, quantifiable investigation of the 1U mL-1 thrombin-induced PR from 32 healthy adults was conducted. MS proteomics data are available via ProteomeXchange, identifier PXD009310. Of the 894 proteins identified, 277 proteins were quantified across all donors and form a "core" PR. Bioinformatics and further LFQ-proteomic analysis revealed that the majority (84%) of "core" PR proteins overlapped with the protein composition of human platelet-derived exosomes. Vesicles in the exosomal-size range were confirmed in healthy-human PR and reduced numbers of similar-sized vesicles were observed in the PR of a mouse model of gray platelet syndrome, known to be deficient in platelet alpha-granules. Lastly, the variability of proteins in the PR was assessed, and reproducible secretion levels were found across all 32 healthy donors. Taken together, the PR contains valuable soluble and vesicular cargo and has low-population variance among healthy adults, rendering it a potentially useful platform for diagnostic fingerprinting of platelet-related disease.
Collapse
Affiliation(s)
- Martin E M Parsons
- SPHERE research group, Conway Institute, University College Dublin, Dublin 4, Ireland.,Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin 2, Ireland.,School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Paulina B Szklanna
- SPHERE research group, Conway Institute, University College Dublin, Dublin 4, Ireland.,Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin 2, Ireland.,School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Jose A Guerrero
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Camebridge, United Kingdom.,National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Kieran Wynne
- Proteomics Core, Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Feidhlim Dervin
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Karen O'Connell
- Department of Neurology, St Vincent's University Hospital, Dublin 4, Ireland.,School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Seamus Allen
- SPHERE research group, Conway Institute, University College Dublin, Dublin 4, Ireland.,School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland.,School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Karl Egan
- SPHERE research group, Conway Institute, University College Dublin, Dublin 4, Ireland.,Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin 2, Ireland.,School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Cavan Bennett
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Camebridge, United Kingdom.,National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Christopher McGuigan
- Department of Neurology, St Vincent's University Hospital, Dublin 4, Ireland.,School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Cedric Gheveart
- Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Camebridge, United Kingdom.,National Health Service Blood and Transplant, Cambridge Biomedical Campus, Cambridge, United Kingdom
| | - Fionnuala Ní Áinle
- SPHERE research group, Conway Institute, University College Dublin, Dublin 4, Ireland.,Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin 2, Ireland.,School of Medicine, University College Dublin, Dublin 4, Ireland.,Department of Haematology, Rotunda Hospital, Dublin 1, Ireland.,Department of Haematology, Mater Misericordiae University Hospital, Dublin 7, Ireland
| | - Patricia B Maguire
- SPHERE research group, Conway Institute, University College Dublin, Dublin 4, Ireland.,Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin 2, Ireland.,School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland.,UCD Institute for Discovery, O'Brien Centre for Science, University College Dublin, Dublin, Ireland
| |
Collapse
|
568
|
Yeung J, Li W, Holinstat M. Platelet Signaling and Disease: Targeted Therapy for Thrombosis and Other Related Diseases. Pharmacol Rev 2018; 70:526-548. [PMID: 29925522 PMCID: PMC6013590 DOI: 10.1124/pr.117.014530] [Citation(s) in RCA: 132] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Platelets are essential for clotting in the blood and maintenance of normal hemostasis. Under pathologic conditions such as atherosclerosis, vascular injury often results in hyperactive platelet activation, resulting in occlusive thrombus formation, myocardial infarction, and stroke. Recent work in the field has elucidated a number of platelet functions unique from that of maintaining hemostasis, including regulation of tumor growth and metastasis, inflammation, infection, and immune response. Traditional therapeutic targets for inhibiting platelet activation have primarily been limited to cyclooxygenase-1, integrin αIIbβ3, and the P2Y12 receptor. Recently identified signaling pathways regulating platelet function have made it possible to develop novel approaches for pharmacological intervention in the blood to limit platelet reactivity. In this review, we cover the newly discovered roles for platelets as well as their role in hemostasis and thrombosis. These new roles for platelets lend importance to the development of new therapies targeted to the platelet. Additionally, we highlight the promising receptor and enzymatic targets that may further decrease platelet activation and help to address the myriad of pathologic conditions now known to involve platelets without significant effects on hemostasis.
Collapse
Affiliation(s)
- Jennifer Yeung
- Departments of Pharmacology (J.Y., W.L., M.H.) and Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor, Michigan
| | - Wenjie Li
- Departments of Pharmacology (J.Y., W.L., M.H.) and Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor, Michigan
| | - Michael Holinstat
- Departments of Pharmacology (J.Y., W.L., M.H.) and Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor, Michigan
| |
Collapse
|
569
|
Kitamura Y, Isobe K, Kawabata H, Tsujino T, Watanabe T, Nakamura M, Toyoda T, Okudera H, Okuda K, Nakata K, Kawase T. Quantitative evaluation of morphological changes in activated platelets in vitro using digital holographic microscopy. Micron 2018; 113:1-9. [PMID: 29936304 DOI: 10.1016/j.micron.2018.06.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 05/05/2018] [Accepted: 06/15/2018] [Indexed: 12/13/2022]
Abstract
Platelet activation and aggregation have been conventionally evaluated using an aggregometer. However, this method is suitable for short-term but not long-term quantitative evaluation of platelet aggregation, morphological changes, and/or adhesion to specific materials. The recently developed digital holographic microscopy (DHM) has enabled the quantitative evaluation of cell size and morphology without labeling or destruction. Thus, we aim to validate its applicability in quantitatively evaluating changes in cell morphology, especially in the aggregation and spreading of activated platelets, thus modifying typical image analysis procedures to suit aggregated platelets. Freshly prepared platelet-rich plasma was washed with phosphate-buffered saline and treated with 0.1% CaCl2. Platelets were then fixed and subjected to DHM, scanning electron microscopy (SEM), atomic force microscopy, optical microscopy, and flow cytometry (FCM). Tightly aggregated platelets were identified as single cells. Data obtained from time-course experiments were plotted two-dimensionally according to the average optical thickness versus attachment area and divided into four regions. The majority of the control platelets, which supposedly contained small and round platelets, were distributed in the lower left region. As activation time increased, however, this population dispersed toward the upper right region. The distribution shift demonstrated by DHM was essentially consistent with data obtained from SEM and FCM. Therefore, DHM was validated as a promising device for testing platelet function given that it allows for the quantitative evaluation of activation-dependent morphological changes in platelets. DHM technology will be applicable to the quality assurance of platelet concentrates, as well as diagnosis and drug discovery related to platelet functions.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Kazuhiro Okuda
- Division of Periodontology, Institute of Medicine and Dentistry, Niigata University, Niigata, Japan
| | - Koh Nakata
- Bioscience Medical Research Center, Niigata University Medical and Dental Hospital, Niigata, Japan
| | - Tomoyuki Kawase
- Division of Oral Bioengineering, Institute of Medicine and Dentistry, Niigata University, Niigata, 951-8514, Japan.
| |
Collapse
|
570
|
Budnik I, Shenkman B, Morozova O, Andreichyn J, Einav Y. Correction of coagulopathy in thrombocytopenia and Glanzmann thrombasthenia models by fibrinogen and factor XIII as assessed by thromboelastometry. ACTA ACUST UNITED AC 2018; 25:347-351. [PMID: 29805054 DOI: 10.1016/j.pathophys.2018.05.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/07/2018] [Accepted: 05/22/2018] [Indexed: 11/24/2022]
Abstract
Thrombocytopenia (TCP) and Glanzmann thrombasthenia (GT) are typical platelet disorders characterized by mild to severe bleeding. This study aims to create in vitro models of TCP and GT and to correct the impaired clot formation by fibrinogen and coagulation factor XIII. The TCP model (mean platelet count, 16 × 109 L-1) was produced by differential centrifugation of normal blood followed by mixing plasma with packed cells. The GT model was created by treating normal blood with 50 μg/mL eptifibatide, an inhibitor of platelet integrin αIIbβ3. Clot formation was evaluated in whole blood by rotation thromboelastometry. In both models, the extent of clot strength was two-three times lower compared to normal blood. Fibrinogen and, to a lesser extent, factor XIII stimulated the propagation phase of clot formation both in TCP and GT models. Clot strength in TCP was increased by both agents, while in GT by fibrinogen only. Similar results were obtained in blood from patients with primary immune thrombocytopenia and Glanzmann thrombasthenia. In conclusion, the created models may be useful in the development of new ways to correct the impaired coagulation potential in TCP and GT.
Collapse
Affiliation(s)
- Ivan Budnik
- Sechenov First Moscow State Medical University, Moscow, Russia.
| | | | - Olga Morozova
- Sechenov First Moscow State Medical University, Moscow, Russia
| | - Jurii Andreichyn
- Ivan Horbachevsky Ternopil State Medical University, Ternopil, Ukraine
| | - Yulia Einav
- Holon Institute of Technology, Holon, Israel
| |
Collapse
|
571
|
Luu S, Gardiner EE, Andrews RK. Bone Marrow Defects and Platelet Function: A Focus on MDS and CLL. Cancers (Basel) 2018; 10:E147. [PMID: 29783667 PMCID: PMC5977120 DOI: 10.3390/cancers10050147] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 05/11/2018] [Accepted: 05/16/2018] [Indexed: 12/16/2022] Open
Abstract
The bloodstream typically contains >500 billion anucleate circulating platelets, derived from megakaryocytes in the bone marrow. This review will focus on two interesting aspects of bone marrow dysfunction and how this impacts on the quality of circulating platelets. In this regard, although megakaryocytes are from the myeloid lineage leading to granulocytes (including neutrophils), erythrocytes, and megakaryocytes/platelets, recent evidence has shown that defects in the lymphoid lineage leading to B cells, T cells, and natural killer (NK) cells also result in abnormal circulating platelets. Current evidence is limited regarding whether this latter phenomenon might potentially arise from (a) some form of as-yet-undetected defect common to both lineages; (b) adverse interactions occurring between cells of different lineages within the bone marrow environment; and/or (c) unknown disease-related factor(s) affecting circulating platelet receptor expression/function after their release from megakaryocytes. Understanding the mechanisms underlying how both myeloid and lymphoid lineage bone marrow defects lead to dysfunction of circulating platelets is significant because of the potential diagnostic and predictive value of peripheral platelet analysis for bone marrow disease progression, the additional potential effects of new anti-cancer drugs on platelet function, and the critical role platelets play in regulation of bleeding risk, inflammation, and innate immunity.
Collapse
Affiliation(s)
- Sarah Luu
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.
| | - Elizabeth E Gardiner
- ACRF Department of Cancer Biology and Therapeutics, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2600, Australia.
| | - Robert K Andrews
- Australian Centre for Blood Diseases, Monash University, Melbourne, VIC 3004, Australia.
| |
Collapse
|
572
|
Richards GA, Theron A, Tintinger G, Anderson R. The Effects of Dabigatran and Rivaroxaban on Markers of Polymorphonuclear Leukocyte Activation. Pharmaceuticals (Basel) 2018; 11:ph11020046. [PMID: 29758017 PMCID: PMC6027144 DOI: 10.3390/ph11020046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/03/2018] [Accepted: 05/04/2018] [Indexed: 12/20/2022] Open
Abstract
Dabigatran is an oral direct thrombin inhibitor, and rivaroxaban, a factor Xa inhibitor. Dabigatran has been implicated in the etiology of acute coronary syndromes and as these occur following inflammatory changes in the endothelium, we investigated the inflammatory potential of these agents in vitro. In order to do so, polymorphonuclear leukocytes (PMNL) were isolated from heparinized venous blood from non-smoking, healthy adults and exposed to dabigatran or rivaroxaban (0.5–10 µM). Generation of reactive oxygen species (ROS), elastase release, cytosolic Ca2+ fluxes, neutrophil extracellular trap (NET) formation and cell viability were measured using chemiluminescence, spectrophotometric and flow cytometric procedures respectively. However, with the exception of modest inhibitory effects on elastase release, neither agent at concentrations of up to 10 µM affected these markers of PMNL activation. Although no pro-inflammatory effects of dabigatran nor any difference between the two test agents were detected in vitro, the existence of a pro-inflammatory mechanism involving the generation of thrombin during dabigatran therapy cannot be fully excluded.
Collapse
Affiliation(s)
- Guy A Richards
- Department of Critical Care, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.
| | - Annette Theron
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa.
- Tshwane Academic Division of the National Health Laboratory Service of South Africa, Pretoria 0001, South Africa.
| | - Gregory Tintinger
- Department of Internal Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa.
| | - Ronald Anderson
- Department of Immunology, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa.
- Tshwane Academic Division of the National Health Laboratory Service of South Africa, Pretoria 0001, South Africa.
| |
Collapse
|
573
|
Toll-like receptors in immunity and inflammatory diseases: Past, present, and future. Int Immunopharmacol 2018; 59:391-412. [PMID: 29730580 PMCID: PMC7106078 DOI: 10.1016/j.intimp.2018.03.002] [Citation(s) in RCA: 408] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 02/28/2018] [Accepted: 03/01/2018] [Indexed: 02/07/2023]
Abstract
The immune system is a very diverse system of the host that evolved during evolution to cope with various pathogens present in the vicinity of environmental surroundings inhabited by multicellular organisms ranging from achordates to chordates (including humans). For example, cells of immune system express various pattern recognition receptors (PRRs) that detect danger via recognizing specific pathogen-associated molecular patterns (PAMPs) and mount a specific immune response. Toll-like receptors (TLRs) are one of these PRRs expressed by various immune cells. However, they were first discovered in the Drosophila melanogaster (common fruit fly) as genes/proteins important in embryonic development and dorso-ventral body patterning/polarity. Till date, 13 different types of TLRs (TLR1-TLR13) have been discovered and described in mammals since the first discovery of TLR4 in humans in late 1997. This discovery of TLR4 in humans revolutionized the field of innate immunity and thus the immunology and host-pathogen interaction. Since then TLRs are found to be expressed on various immune cells and have been targeted for therapeutic drug development for various infectious and inflammatory diseases including cancer. Even, Single nucleotide polymorphisms (SNPs) among various TLR genes have been identified among the different human population and their association with susceptibility/resistance to certain infections and other inflammatory diseases. Thus, in the present review the current and future importance of TLRs in immunity, their pattern of expression among various immune cells along with TLR based therapeutic approach is reviewed. TLRs are first described PRRs that revolutionized the biology of host-pathogen interaction and immune response The discovery of different TLRs in humans proved milestone in the field of innate immunity and inflammation The pattern of expression of all the TLRs expressed by human immune cells An association of various TLR SNPs with different inflammatory diseases Currently available drugs or vaccines based on TLRs and their future in drug targeting along with the role in reproduction, and regeneration
Collapse
|
574
|
Swinkels M, Rijkers M, Voorberg J, Vidarsson G, Leebeek FWG, Jansen AJG. Emerging Concepts in Immune Thrombocytopenia. Front Immunol 2018; 9:880. [PMID: 29760702 PMCID: PMC5937051 DOI: 10.3389/fimmu.2018.00880] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 04/09/2018] [Indexed: 01/19/2023] Open
Abstract
Immune thrombocytopenia (ITP) is an autoimmune disease defined by low platelet counts which presents with an increased bleeding risk. Several genetic risk factors (e.g., polymorphisms in immunity-related genes) predispose to ITP. Autoantibodies and cytotoxic CD8+ T cells (Tc) mediate the anti-platelet response leading to thrombocytopenia. Both effector arms enhance platelet clearance through phagocytosis by splenic macrophages or dendritic cells and by induction of apoptosis. Meanwhile, platelet production is inhibited by CD8+ Tc targeting megakaryocytes in the bone marrow. CD4+ T helper cells are important for B cell differentiation into autoantibody secreting plasma cells. Regulatory Tc are essential to secure immune tolerance, and reduced levels have been implicated in the development of ITP. Both Fcγ-receptor-dependent and -independent pathways are involved in the etiology of ITP. In this review, we present a simplified model for the pathogenesis of ITP, in which exposure of platelet surface antigens and a loss of tolerance are required for development of chronic anti-platelet responses. We also suggest that infections may comprise an important trigger for the development of auto-immunity against platelets in ITP. Post-translational modification of autoantigens has been firmly implicated in the development of autoimmune disorders like rheumatoid arthritis and type 1 diabetes. Based on these findings, we propose that post-translational modifications of platelet antigens may also contribute to the pathogenesis of ITP.
Collapse
Affiliation(s)
- Maurice Swinkels
- Department of Hematology, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - Maaike Rijkers
- Department of Plasma Proteins, AMC-Sanquin Landsteiner Laboratory, Amsterdam, Netherlands
| | - Jan Voorberg
- Department of Plasma Proteins, AMC-Sanquin Landsteiner Laboratory, Amsterdam, Netherlands
| | - Gestur Vidarsson
- Department of Experimental Immunohematology, AMC-Sanquin Landsteiner Laboratory, Amsterdam, Netherlands
| | - Frank W G Leebeek
- Department of Hematology, Erasmus University Medical Centre, Rotterdam, Netherlands
| | - A J Gerard Jansen
- Department of Hematology, Erasmus University Medical Centre, Rotterdam, Netherlands.,Department of Plasma Proteins, AMC-Sanquin Landsteiner Laboratory, Amsterdam, Netherlands
| |
Collapse
|
575
|
Anderson R, Nel JG, Feldman C. Multifaceted Role of Pneumolysin in the Pathogenesis of Myocardial Injury in Community-Acquired Pneumonia. Int J Mol Sci 2018; 19:E1147. [PMID: 29641429 PMCID: PMC5979279 DOI: 10.3390/ijms19041147] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/14/2018] [Accepted: 03/21/2018] [Indexed: 12/14/2022] Open
Abstract
Pneumolysin (PLY), a member of the family of Gram-positive bacterial, cholesterol-dependent, β-barrel pore-forming cytolysins, is the major protein virulence factor of the dangerous respiratory pathogen, Streptococcus pneumoniae (pneumococcus). PLY plays a major role in the pathogenesis of community-acquired pneumonia (CAP), promoting colonization and invasion of the upper and lower respiratory tracts respectively, as well as extra-pulmonary dissemination of the pneumococcus. Notwithstanding its role in causing acute lung injury in severe CAP, PLY has also been implicated in the development of potentially fatal acute and delayed-onset cardiovascular events, which are now recognized as being fairly common complications of this condition. This review is focused firstly on updating mechanisms involved in the immunopathogenesis of PLY-mediated myocardial damage, specifically the direct cardiotoxic and immunosuppressive activities, as well as the indirect pro-inflammatory/pro-thrombotic activities of the toxin. Secondly, on PLY-targeted therapeutic strategies including, among others, macrolide antibiotics, natural product antagonists, cholesterol-containing liposomes, and fully humanized monoclonal antibodies, as well as on vaccine-based preventive strategies. These sections are preceded by overviews of CAP in general, the role of the pneumococcus as the causative pathogen, the occurrence and types of CAP-associated cardiac complication, and the structure and biological activities of PLY.
Collapse
Affiliation(s)
- Ronald Anderson
- Department of Immunology and Institute for Cellular and Molecular Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria 0001, South Africa.
| | - Jan G Nel
- Department of Haematology, Faculty of Health Sciences, University of Pretoria and Tshwane Academic Division of the National Health Laboratory Service, Pretoria 0001, South Africa.
| | - Charles Feldman
- Division of Pulmonology, Department of Internal Medicine, Charlotte Maxeke Johannesburg Academic Hospital and Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 0002, South Africa.
| |
Collapse
|
576
|
Flick MJ, Palumbo JS. Platelets couple inflammation to tumorigenesis, a bridge too far. J Thromb Haemost 2018; 16:759-761. [PMID: 29418061 DOI: 10.1111/jth.13967] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Indexed: 12/16/2022]
Affiliation(s)
- M J Flick
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - J S Palumbo
- Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center and the University of Cincinnati College of Medicine, Cincinnati, OH, USA
| |
Collapse
|
577
|
Gardiner EE. Proteolytic processing of platelet receptors. Res Pract Thromb Haemost 2018; 2:240-250. [PMID: 30046726 PMCID: PMC6055504 DOI: 10.1002/rth2.12096] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 03/01/2018] [Indexed: 12/17/2022] Open
Abstract
Platelets have a major role in hemostasis and an emerging role in biological processes including inflammation and immunity. Many of these processes require platelet adhesion and localization at sites of tissue damage or infection and regulated platelet activation, mediated by platelet adheso-signalling receptors, glycoprotein (GP) Ib-IX-V and GPVI. Work from a number of laboratories has demonstrated that levels of these receptors are closely regulated by metalloproteinases of the A Disintegrin And Metalloproteinase (ADAM) family, primarily ADAM17 and ADAM10. It is becoming increasingly evident that platelets have important roles in innate immunity, inflammation, and in combating infection that extends beyond processes of hemostasis. This overview will examine the molecular events that regulate levels of platelet receptors and then assess ramifications for these events in settings where hemostasis, inflammation, and infection processes are triggered.
Collapse
Affiliation(s)
- Elizabeth E. Gardiner
- ACRF Department of Cancer Biology and TherapeuticsJohn Curtin School of Medical ResearchThe Australian National UniversityCanberraACTAustralia
| |
Collapse
|