1
|
Kostyak JC, McKenzie SE, Naik UP. The Function of ASK1 in Sepsis and Stress-Induced Disorders. Int J Mol Sci 2023; 25:213. [PMID: 38203381 PMCID: PMC10778746 DOI: 10.3390/ijms25010213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
Apoptosis signal-regulating kinase 1 (ASK1) is a serine-threonine kinase that is ubiquitously expressed in nucleated cells and is responsible for the activation of multiple mitogen-activated protein kinases (MAPK) to regulate cell stress. Activation of ASK1 via cellular stress leads to activation of downstream signaling components, activation of transcription factors, and proinflammatory cytokine production. ASK1 is also expressed in anucleate platelets and is a key player in platelet activation as it is important for signaling. Interestingly, the mechanism of ASK1 activation is cell type-dependent. In this review we will explore how ASK1 regulates a variety of cellular processes from innate immune function to thrombosis and hemostasis. We will discuss how ASK1 influences FcγRIIA-mediated platelet reactivity and how that reactivity drives platelet clearance. Furthermore, we will explore the role of ASK1 in thromboxane (TxA2) generation, which highlights differences in the way ASK1 functions in mouse and human platelets.
Collapse
Affiliation(s)
- John C. Kostyak
- Cardeza Center for Hemostasis, Thrombosis, and Vascular Biology, Cardeza Foundation for Hematologic Research, Department of Medicine, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA; (S.E.M.); (U.P.N.)
| | | | | |
Collapse
|
2
|
Valtin J, Behrens S, Ruland A, Schmieder F, Sonntag F, Renner LD, Maitz MF, Werner C. A New In Vitro Blood Flow Model for the Realistic Evaluation of Antimicrobial Surfaces. Adv Healthc Mater 2023; 12:e2301300. [PMID: 37498721 DOI: 10.1002/adhm.202301300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/13/2023] [Indexed: 07/29/2023]
Abstract
Device-associated bloodstream infections can cause serious medical problems and cost-intensive postinfection management, defining a need for more effective antimicrobial coatings. Newly developed coatings often show reduced bacterial colonization and high hemocompatibility in established in vitro tests, but fail in animal studies or clinical trials. The poor predictive power of these models is attributed to inadequate representation of in vivo conditions. Herein, a new single-pass blood flow model, with simultaneous incubation of the test surface with bacteria and freshly-drawn human blood, is presented. The flow model is validated by comparative analysis of a recently developed set of antiadhesive and contact-killing polymer coatings, and the corresponding uncoated polycarbonate surfaces. The results confirm the model's ability to differentiate the antimicrobial activities of the studied surfaces. Blood activation data correlate with bacterial surface coverage: low bacterial adhesion is associated with low inflammation and hemostasis. Shear stress correlates inversely with bacterial colonization, especially on antiadhesive surfaces. The introduced model is concluded to enable the evaluation of novel antimicrobial materials under in vivo-like conditions, capturing interactions between bacteria and biomaterials surfaces in the presence of key components of the ex vivo host response.
Collapse
Affiliation(s)
- Juliane Valtin
- Leibniz Institute of Polymer Research Dresden, Institute of Biofunctional Polymer Materials, Hohe Strasse 6, 01069, Dresden, Germany
| | - Stephan Behrens
- Fraunhofer Institute for Material and Beam Technology IWS, 01277, Dresden, Germany
| | - André Ruland
- Leibniz Institute of Polymer Research Dresden, Institute of Biofunctional Polymer Materials, Hohe Strasse 6, 01069, Dresden, Germany
| | - Florian Schmieder
- Fraunhofer Institute for Material and Beam Technology IWS, 01277, Dresden, Germany
| | - Frank Sonntag
- Fraunhofer Institute for Material and Beam Technology IWS, 01277, Dresden, Germany
| | - Lars D Renner
- Leibniz Institute of Polymer Research Dresden, Institute of Biofunctional Polymer Materials, Hohe Strasse 6, 01069, Dresden, Germany
| | - Manfred F Maitz
- Leibniz Institute of Polymer Research Dresden, Institute of Biofunctional Polymer Materials, Hohe Strasse 6, 01069, Dresden, Germany
| | - Carsten Werner
- Leibniz Institute of Polymer Research Dresden, Institute of Biofunctional Polymer Materials, Hohe Strasse 6, 01069, Dresden, Germany
- Technische Universität Dresden, Cluster of Excellence Physics of Life, Center for Regenerative Therapies Dresden and Faculty of Chemistry and Food Chemistry, 01307, Dresden, Germany
| |
Collapse
|
3
|
Gautam I, Huss CW, Storad ZA, Krebs M, Bassiouni O, Ramesh R, Wuescher LM, Worth RG. Activated Platelets Mediate Monocyte Killing of Klebsiella pneumoniae. Infect Immun 2023; 91:e0055622. [PMID: 36853027 PMCID: PMC10016073 DOI: 10.1128/iai.00556-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/02/2023] [Indexed: 03/01/2023] Open
Abstract
Platelets are known for essential activities in hemostasis and for their important contribution to protection against infectious pathogens. Klebsiella pneumoniae is an opportunistic pathogen widely known to cause nosocomial infections. Recently, hypervirulent strains of K. pneumoniae have been emerging, which can cause severe infections in immunocompetent individuals. Combined with the increase in antibiotic resistance, it is important to understand how K. pneumoniae affects components of the immune system. We studied the interactions of human platelets with several K. pneumoniae strains (the wild type encapsulated strain, and a nonencapsulated mutant). Thrombin-stimulated whole human and mouse blood significantly inhibited bacterial growth compared to unstimulated whole blood. Furthermore, we investigated the effect of K. pneumoniae on platelet activation. Both strains induced significant increase in activation of both unstimulated and thrombin-stimulated human platelets. Additionally, only the nonencapsulated mutant increased aggregation of platelets in response to ADP. K. pneumoniae killing assays were then performed with washed platelets in the presence or absence of thrombin. Surprisingly, washed platelets failed to exhibit any effects on the growth of K. pneumoniae. We further explored the impact of platelets on monocyte-mediated killing of K. pneumoniae. Importantly, we found that activated platelets significantly enhanced monocyte-mediated killing of K. pneumoniae. This effect was likely due to the formation of platelet-monocyte aggregates in blood upon thrombin stimulation. Overall, this study highlights the role of platelets in mediating a protective response against K. pneumoniae and reinforces the importance of platelets in modulating leukocyte behavior.
Collapse
Affiliation(s)
- Iluja Gautam
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Chadwick W. Huss
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Zachary A. Storad
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Michelle Krebs
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Omar Bassiouni
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Rochan Ramesh
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Leah M. Wuescher
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| | - Randall G. Worth
- Department of Medical Microbiology and Immunology, University of Toledo, Toledo, Ohio, USA
| |
Collapse
|
4
|
Winskel-Wood B, Padula MP, Marks DC, Johnson L. Cold storage alters the immune characteristics of platelets and potentiates bacterial-induced aggregation. Vox Sang 2022; 117:1006-1015. [PMID: 35579630 DOI: 10.1111/vox.13293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/13/2022] [Accepted: 04/20/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVES Cold-stored platelets are currently under clinical evaluation and have been approved for limited clinical use in the United States. Most studies have focused on the haemostatic functionality of cold-stored platelets; however, limited information is available examining changes to their immune function. MATERIALS AND METHODS Two buffy-coat-derived platelet components were combined and split into two treatment arms: room temperature (RT)-stored (20-24°C) or refrigerated (cold-stored, 2-6°C). The concentration of select soluble factors was measured in the supernatant using commercial ELISA kits. The abundance of surface receptors associated with immunological function was assessed by flow cytometry. Platelet aggregation was assessed in response to Escherichia coli and Staphylococcus aureus, in the presence and absence of RGDS (blocks active conformation of integrin α2 β3 ). RESULTS Cold-stored platelet components contained a lower supernatant concentration of C3a, RANTES and PF4. The abundance of surface-bound P-selectin and integrin α2 β3 in the activated conformation increased during cold storage. In comparison, the abundance of CD86, CD44, ICAM-2, CD40, TLR1, TLR2, TLR4, TLR3, TLR7 and TLR9 was lower on the surface membrane of cold-stored platelets compared to RT-stored components. Cold-stored platelets exhibited an increased responsiveness to E. coli- and S. aureus-induced aggregation compared to RT-stored platelets. Inhibition of the active conformation of integrin α2 β3 using RGDS reduced the potentiation of bacterial-induced aggregation in cold-stored platelets. CONCLUSION Our data highlight that cold storage changes the in vitro immune characteristics of platelets, including their sensitivity to bacterial-induced aggregation. Changes in these immune characteristics may have clinical implications post transfusion.
Collapse
Affiliation(s)
- Ben Winskel-Wood
- Research and Development, Australian Red Cross Lifeblood, Alexandria, New South Wales, Australia.,School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Matthew P Padula
- School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Denese C Marks
- Research and Development, Australian Red Cross Lifeblood, Alexandria, New South Wales, Australia.,Sydney Medical School, The University of Sydney, Camperdown, New South Wales, Australia
| | - Lacey Johnson
- Research and Development, Australian Red Cross Lifeblood, Alexandria, New South Wales, Australia.,School of Life Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| |
Collapse
|
5
|
Jahn K, Kohler TP, Swiatek LS, Wiebe S, Hammerschmidt S. Platelets, Bacterial Adhesins and the Pneumococcus. Cells 2022; 11:cells11071121. [PMID: 35406684 PMCID: PMC8997422 DOI: 10.3390/cells11071121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/22/2022] [Accepted: 03/22/2022] [Indexed: 01/25/2023] Open
Abstract
Systemic infections with pathogenic or facultative pathogenic bacteria are associated with activation and aggregation of platelets leading to thrombocytopenia and activation of the clotting system. Bacterial proteins leading to platelet activation and aggregation have been identified, and while platelet receptors are recognized, induced signal transduction cascades are still often unknown. In addition to proteinaceous adhesins, pathogenic bacteria such as Staphylococcus aureus and Streptococcus pneumoniae also produce toxins such as pneumolysin and alpha-hemolysin. They bind to cellular receptors or form pores, which can result in disturbance of physiological functions of platelets. Here, we discuss the bacteria-platelet interplay in the context of adhesin–receptor interactions and platelet-activating bacterial proteins, with a main emphasis on S. aureus and S. pneumoniae. More importantly, we summarize recent findings of how S. aureus toxins and the pore-forming toxin pneumolysin of S. pneumoniae interfere with platelet function. Finally, the relevance of platelet dysfunction due to killing by toxins and potential treatment interventions protecting platelets against cell death are summarized.
Collapse
|
6
|
Naylor-Adamson L, Chacko AR, Booth Z, Caserta S, Jarvis J, Khan S, Hart SP, Rivero F, Allsup DJ, Arman M. Bruton's Tyrosine Kinase Inhibitors Impair FcγRIIA-Driven Platelet Responses to Bacteria in Chronic Lymphocytic Leukemia. Front Immunol 2021; 12:766272. [PMID: 34912339 PMCID: PMC8667317 DOI: 10.3389/fimmu.2021.766272] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 10/25/2021] [Indexed: 01/01/2023] Open
Abstract
Bacterial infections are a major cause of morbidity and mortality in chronic lymphocytic leukemia (CLL), and infection risk increases in patients treated with the Bruton’s tyrosine kinase (Btk) inhibitor, ibrutinib. Btk and related kinases (like Tec) are expressed in non-leukemic hematopoietic cells and can be targeted by ibrutinib. In platelets, ibrutinib therapy is associated with bleeding complications mostly due to off-target effects. But the ability of platelets to respond to bacteria in CLL, and the potential impact of ibrutinib on platelet innate immune functions remain unknown. FcγRIIA is a tyrosine kinase-dependent receptor critical for platelet activation in response to IgG-coated pathogens. Crosslinking of this receptor with monoclonal antibodies causes downstream activation of Btk and Tec in platelets, however, this has not been investigated in response to bacteria. We asked whether ibrutinib impacts on FcγRIIA-mediated activation of platelets derived from CLL patients and healthy donors after exposure to Staphylococcus aureus Newman and Escherichia coli RS218. Platelet aggregation, α-granule secretion and integrin αIIbβ3-dependent scavenging of bacteria were detected in CLL platelets but impaired in platelets from ibrutinib-treated patients and in healthy donor-derived platelets exposed to ibrutinib in vitro. While levels of surface FcγRIIA remained unaffected, CLL platelets had reduced expression of integrin αIIbβ3 and GPVI compared to controls regardless of therapy. In respect of intracellular signaling, bacteria induced Btk and Tec phosphorylation in both CLL and control platelets that was inhibited by ibrutinib. To address if Btk is essential for platelet activation in response to bacteria, platelets derived from X-linked agammaglobulinemia patients (lacking functional Btk) were exposed to S. aureus Newman and E. coli RS218, and FcγRIIA-dependent aggregation was observed. Our data suggest that ibrutinib impairment of FcγRIIA-mediated platelet activation by bacteria results from a combination of Btk and Tec inhibition, although off-target effects on additional kinases cannot be discarded. This is potentially relevant to control infection-risk in CLL patients and, thus, future studies should carefully evaluate the effects of CLL therapies, including Btk inhibitors with higher specificity for Btk, on platelet-mediated immune functions.
Collapse
Affiliation(s)
- Leigh Naylor-Adamson
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull, Hull, United Kingdom
| | - Anisha R Chacko
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull, Hull, United Kingdom
| | - Zoe Booth
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull, Hull, United Kingdom
| | - Stefano Caserta
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Hull, Hull, United Kingdom
| | - Jenna Jarvis
- Department of Biomedical Sciences, Faculty of Health Sciences, University of Hull, Hull, United Kingdom
| | - Sujoy Khan
- Department of Immunology & Allergy, Queens Centre, Castle Hill Hospital, Hull University Teaching Hospitals NHS Trust, Cottingham, United Kingdom
| | - Simon P Hart
- Respiratory Research Group, Hull York Medical School, Faculty of Health Sciences, University of Hull, Hull, United Kingdom
| | - Francisco Rivero
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull, Hull, United Kingdom
| | - David J Allsup
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull, Hull, United Kingdom.,Department of Haematology, Queens Centre for Oncology and Haematology, Castle Hill Hospital, Hull University Teaching Hospitals NHS Trust, Cottingham, United Kingdom
| | - Mònica Arman
- Centre for Atherothrombosis and Metabolic Disease, Hull York Medical School, Faculty of Health Sciences, University of Hull, Hull, United Kingdom
| |
Collapse
|
7
|
Ebermeyer T, Cognasse F, Berthelot P, Mismetti P, Garraud O, Hamzeh-Cognasse H. Platelet Innate Immune Receptors and TLRs: A Double-Edged Sword. Int J Mol Sci 2021; 22:ijms22157894. [PMID: 34360659 PMCID: PMC8347377 DOI: 10.3390/ijms22157894] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/14/2021] [Accepted: 07/20/2021] [Indexed: 12/17/2022] Open
Abstract
Platelets are hematopoietic cells whose main function has for a long time been considered to be the maintenance of vascular integrity. They have an essential role in the hemostatic response, but they also have functional capabilities that go far beyond it. This review will provide an overview of platelet functions. Indeed, stress signals may induce platelet apoptosis through proapoptotis or hemostasis receptors, necrosis, and even autophagy. Platelets also interact with immune cells and modulate immune responses in terms of activation, maturation, recruitment and cytokine secretion. This review will also show that platelets, thanks to their wide range of innate immune receptors, and in particular toll-like receptors, and can be considered sentinels actively participating in the immuno-surveillance of the body. We will discuss the diversity of platelet responses following the engagement of these receptors as well as the signaling pathways involved. Finally, we will show that while platelets contribute significantly, via their TLRs, to immune response and inflammation, these receptors also participate in the pathophysiological processes associated with various pathogens and diseases, including cancer and atherosclerosis.
Collapse
Affiliation(s)
- Théo Ebermeyer
- INSERM U1059-SAINBIOSE, Université de Lyon, F-42023 Saint-Etienne, France; (T.E.); (F.C.); (P.M.); (O.G.)
| | - Fabrice Cognasse
- INSERM U1059-SAINBIOSE, Université de Lyon, F-42023 Saint-Etienne, France; (T.E.); (F.C.); (P.M.); (O.G.)
- Etablissement Français du Sang Auvergne-Rhône-Alpes, 25 bd Pasteur, F-42100 Saint-Étienne, France
| | - Philippe Berthelot
- Team GIMAP, CIRI—Centre International de Recherche en Infectiologie, Université de Lyon, U1111, UMR5308, F-69007 Lyon, France;
- Infectious Diseases Department, CHU de St-Etienne, F-42055 Saint-Etienne, France
| | - Patrick Mismetti
- INSERM U1059-SAINBIOSE, Université de Lyon, F-42023 Saint-Etienne, France; (T.E.); (F.C.); (P.M.); (O.G.)
- Department of Vascular Medicine and Therapeutics, INNOVTE, CHU de St-Etienne, F-42055 Saint-Etienne, France
| | - Olivier Garraud
- INSERM U1059-SAINBIOSE, Université de Lyon, F-42023 Saint-Etienne, France; (T.E.); (F.C.); (P.M.); (O.G.)
| | - Hind Hamzeh-Cognasse
- INSERM U1059-SAINBIOSE, Université de Lyon, F-42023 Saint-Etienne, France; (T.E.); (F.C.); (P.M.); (O.G.)
- Correspondence:
| |
Collapse
|
8
|
Sun J, Uchiyama S, Olson J, Morodomi Y, Cornax I, Ando N, Kohno Y, Kyaw MMT, Aguilar B, Haste NM, Kanaji S, Kanaji T, Rose WE, Sakoulas G, Marth JD, Nizet V. Repurposed drugs block toxin-driven platelet clearance by the hepatic Ashwell-Morell receptor to clear Staphylococcus aureus bacteremia. Sci Transl Med 2021; 13:13/586/eabd6737. [PMID: 33762439 DOI: 10.1126/scitranslmed.abd6737] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 03/01/2021] [Indexed: 12/13/2022]
Abstract
Staphylococcus aureus (SA) bloodstream infections cause high morbidity and mortality (20 to 30%) despite modern supportive care. In a human bacteremia cohort, we found that development of thrombocytopenia was correlated to increased mortality and increased α-toxin expression by the pathogen. Platelet-derived antibacterial peptides are important in bloodstream defense against SA, but α-toxin decreased platelet viability, induced platelet sialidase to cause desialylation of platelet glycoproteins, and accelerated platelet clearance by the hepatic Ashwell-Morell receptor (AMR). Ticagrelor (Brilinta), a commonly prescribed P2Y12 receptor inhibitor used after myocardial infarction, blocked α-toxin-mediated platelet injury and resulting thrombocytopenia, thereby providing protection from lethal SA infection in a murine intravenous challenge model. Genetic deletion or pharmacological inhibition of AMR stabilized platelet counts and enhanced resistance to SA infection, and the anti-influenza sialidase inhibitor oseltamivir (Tamiflu) provided similar therapeutic benefit. Thus, a "toxin-platelet-AMR" regulatory pathway plays a critical role in the pathogenesis of SA bloodstream infection, and its elucidation provides proof of concept for repurposing two commonly prescribed drugs as adjunctive therapies to improve patient outcomes.
Collapse
Affiliation(s)
- Josh Sun
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA.,Department of Pediatrics, UC San Diego, La Jolla, CA 92093, USA.,Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA 92093, USA
| | - Satoshi Uchiyama
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA
| | - Joshua Olson
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA
| | - Yosuke Morodomi
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, Scripps Research, La Jolla, CA 92037, USA
| | - Ingrid Cornax
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA
| | - Nao Ando
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA
| | - Yohei Kohno
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA
| | - May M T Kyaw
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA
| | - Bernice Aguilar
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA
| | - Nina M Haste
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA.,Department of Pediatrics, UC San Diego, La Jolla, CA 92093, USA.,Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA 92093, USA
| | - Sachiko Kanaji
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, Scripps Research, La Jolla, CA 92037, USA
| | - Taisuke Kanaji
- Department of Molecular Medicine, MERU-Roon Research Center on Vascular Biology, Scripps Research, La Jolla, CA 92037, USA
| | - Warren E Rose
- School of Pharmacy, University of Wisconsin, Madison, WI 53705, USA
| | - George Sakoulas
- Department of Pediatrics, UC San Diego, La Jolla, CA 92093, USA
| | - Jamey D Marth
- Center for Nanomedicine, UC Santa Barbara, Santa Barbara, CA 93106, USA.,Sanford Burnham Prebys Medical Discovery Institute, UC Santa Barbara, Santa Barbara, CA 93106, USA
| | - Victor Nizet
- Biomedical Sciences Graduate Program, UC San Diego, La Jolla, CA 92093, USA. .,Department of Pediatrics, UC San Diego, La Jolla, CA 92093, USA.,Skaggs School of Pharmacy and Pharmaceutical Sciences, UC San Diego, La Jolla, CA 92093, USA
| |
Collapse
|
9
|
Shannon O. The role of platelets in sepsis. Res Pract Thromb Haemost 2021; 5:27-37. [PMID: 33537527 PMCID: PMC7845078 DOI: 10.1002/rth2.12465] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/06/2020] [Accepted: 10/30/2020] [Indexed: 12/12/2022] Open
Abstract
A State of the Art lecture titled "The role of platelets in sepsis" was presented at the ISTH congress in 2020. Sepsis is a life-threatening organ dysfunction caused by a dysregulated and multifaceted host response to infection. Platelets play a significant role in the coordinated immune response to infection and therefore in the inflammation and coagulation dysfunction that contributes to organ damage in sepsis. Thrombocytopenia has a high incidence in sepsis, and it is a marker of poor prognosis. The genesis of thrombocytopenia is likely multifactorial, and unraveling the involved molecular mechanisms will allow development of biomarkers of platelet function in sepsis. Such platelet biomarkers can facilitate study of antiplatelet interventions as immunomodulatory treatment in sepsis. Finally, relevant new data on this topic presented during the 2020 ISTH virtual congress are reviewed.
Collapse
Affiliation(s)
- Oonagh Shannon
- Division of Infection MedicineDepartment of Clinical SciencesFaculty of MedicineLund UniversityLundSweden
| |
Collapse
|
10
|
Feldman C, Anderson R. Platelets and Their Role in the Pathogenesis of Cardiovascular Events in Patients With Community-Acquired Pneumonia. Front Immunol 2020; 11:577303. [PMID: 33042161 PMCID: PMC7527494 DOI: 10.3389/fimmu.2020.577303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 08/24/2020] [Indexed: 12/21/2022] Open
Abstract
Community-acquired pneumonia (CAP) remains an important cause of morbidity and mortality throughout the world with much recent and ongoing research focused on the occurrence of cardiovascular events (CVEs) during the infection, which are associated with adverse short-term and long-term survival. Much of the research directed at unraveling the pathogenesis of these events has been undertaken in the settings of experimental and clinical CAP caused by the dangerous, bacterial respiratory pathogen, Streptococcus pneumoniae (pneumococcus), which remains the most common bacterial cause of CAP. Studies of this type have revealed that although platelets play an important role in host defense against infection, there is also increasing recognition that hyperactivation of these cells contributes to a pro-inflammatory, prothrombotic systemic milieu that contributes to the etiology of CVEs. In the case of the pneumococcus, platelet-driven myocardial damage and dysfunction is exacerbated by the direct cardiotoxic actions of pneumolysin, a major pore-forming toxin of this pathogen, which also acts as potent activator of platelets. This review is focused on the role of platelets in host defense against infection, including pneumococcal infection in particular, and reviews the current literature describing the potential mechanisms by which platelet activation contributes to cardiovascular complications in CAP. This is preceded by an evaluation of the burden of pneumococcal infection in CAP, the clinical features and putative pathogenic mechanisms of the CVE, and concludes with an evaluation of the potential utility of the anti-platelet activity of macrolides and various adjunctive therapies.
Collapse
Affiliation(s)
- Charles Feldman
- Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Ronald Anderson
- Department of Immunology, Faculty of Health Sciences, Institute of Cellular and Molecular Medicine, University of Pretoria, Pretoria, South Africa
| |
Collapse
|