1
|
Upton JEM, Grunebaum E, Sussman G, Vadas P. Platelet Activating Factor (PAF): A Mediator of Inflammation. Biofactors 2022; 48:1189-1202. [PMID: 36029481 DOI: 10.1002/biof.1883] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 07/21/2022] [Indexed: 12/24/2022]
Abstract
Platelet-activating factor (PAF) is a phospholipid-derived mediator with an established role in multiple inflammatory states. PAF is synthesized and secreted by multiple cell types and is then rapidly hydrolyzed and degraded to an inactive metabolite, lyso-PAF, by the enzyme PAF acetylhydrolase. In addition to its role in platelet aggregation and activation, PAF contributes to allergic and nonallergic inflammatory diseases such as anaphylaxis, sepsis, cardiovascular disease, neurological disease, and malignancy as demonstrated in multiple animal models and, increasingly, in human disease states. Recent research has demonstrated the importance of the PAF pathway in multiple conditions including the prediction of severe pediatric anaphylaxis, effects on blood-brain barrier permeability, effects on reproduction, ocular diseases, and further understanding of its role in cardiovascular risk. Investigation of PAF as both a biomarker and a therapeutic target continues because of the need for directed management of inflammation. Collectively, studies have shown that therapies focused on the PAF pathway have the potential to provide targeted and effective treatments for multiple inflammatory conditions.
Collapse
Affiliation(s)
- Julia E M Upton
- Division of Immunology and Allergy, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Eyal Grunebaum
- Division of Immunology and Allergy, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Gordon Sussman
- Division of Clinical Immunology and Allergy, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Peter Vadas
- Division of Clinical Immunology and Allergy, Department of Medicine, St. Michael's Hospital, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
2
|
The End of “One Size Fits All” Sepsis Therapies: Toward an Individualized Approach. Biomedicines 2022; 10:biomedicines10092260. [PMID: 36140361 PMCID: PMC9496597 DOI: 10.3390/biomedicines10092260] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 12/20/2022] Open
Abstract
Sepsis, defined as life-threatening organ dysfunction caused by a dysregulated host response to an infection, remains a major challenge for clinicians and trialists. Despite decades of research and multiple randomized clinical trials, a specific therapeutic for sepsis is not available. The evaluation of therapeutics targeting components of host response anomalies in patients with sepsis has been complicated by the inability to identify those in this very heterogeneous population who are more likely to benefit from a specific intervention. Additionally, multiple and diverse host response aberrations often co-exist in sepsis, and knowledge of which dysregulated biological organ system or pathway drives sepsis-induced pathology in an individual patient is limited, further complicating the development of effective therapies. Here, we discuss the drawbacks of previous attempts to develop sepsis therapeutics and delineate a future wherein interventions will be based on the host response profile of a patient.
Collapse
|
3
|
Shapiro L, Scherger S, Franco-Paredes C, Gharamti AA, Fraulino D, Henao-Martinez AF. Chasing the Ghost: Hyperinflammation Does Not Cause Sepsis. Front Pharmacol 2022; 13:910516. [PMID: 35814227 PMCID: PMC9260244 DOI: 10.3389/fphar.2022.910516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/23/2022] [Indexed: 12/15/2022] Open
Abstract
Sepsis is infection sufficient to cause illness in the infected host, and more severe forms of sepsis can result in organ malfunction or death. Severe forms of Coronavirus disease-2019 (COVID-19), or disease following infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are examples of sepsis. Following infection, sepsis is thought to result from excessive inflammation generated in the infected host, also referred to as a cytokine storm. Sepsis can result in organ malfunction or death. Since COVID-19 is an example of sepsis, the hyperinflammation concept has influenced scientific investigation and treatment approaches to COVID-19. However, decades of laboratory study and more than 100 clinical trials designed to quell inflammation have failed to reduce sepsis mortality. We examine theoretical support underlying widespread belief that hyperinflammation or cytokine storm causes sepsis. Our analysis shows substantial weakness of the hyperinflammation approach to sepsis that includes conceptual confusion and failure to establish a cause-and-effect relationship between hyperinflammation and sepsis. We conclude that anti-inflammation approaches to sepsis therapy have little chance of future success. Therefore, anti-inflammation approaches to treat COVID-19 are likewise at high risk for failure. We find persistence of the cytokine storm concept in sepsis perplexing. Although treatment approaches based on the hyperinflammation concept of pathogenesis have failed, the concept has shown remarkable resilience and appears to be unfalsifiable. An approach to understanding this resilience is to consider the hyperinflammation or cytokine storm concept an example of a scientific paradigm. Thomas Kuhn developed the idea that paradigms generate rules of investigation that both shape and restrict scientific progress. Intrinsic features of scientific paradigms include resistance to falsification in the face of contradictory data and inability of experimentation to generate alternatives to a failing paradigm. We call for rejection of the concept that hyperinflammation or cytokine storm causes sepsis. Using the hyperinflammation or cytokine storm paradigm to guide COVID-19 treatments is likewise unlikely to provide progress. Resources should be redirected to more promising avenues of investigation and treatment.
Collapse
Affiliation(s)
- Leland Shapiro
- Division of Infectious Diseases, Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO, United States
- Division of Infectious Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Sias Scherger
- Division of Infectious Diseases, Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, CO, United States
| | - Carlos Franco-Paredes
- Division of Infectious Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
- Hospital Infantil de México, Federico Gomez, Mexico City, Mexico
| | - Amal A. Gharamti
- Department of Internal Medicine, Yale University, Waterbury, CT, United States
| | - David Fraulino
- Division of Infectious Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Andrés F. Henao-Martinez
- Division of Infectious Diseases, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| |
Collapse
|
4
|
Zhang YY, Ning BT. Signaling pathways and intervention therapies in sepsis. Signal Transduct Target Ther 2021; 6:407. [PMID: 34824200 PMCID: PMC8613465 DOI: 10.1038/s41392-021-00816-9] [Citation(s) in RCA: 158] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/19/2021] [Accepted: 10/26/2021] [Indexed: 12/12/2022] Open
Abstract
Sepsis is defined as life-threatening organ dysfunction caused by dysregulated host systemic inflammatory and immune response to infection. Over decades, advanced understanding of host-microorganism interaction has gradually unmasked the genuine nature of sepsis, guiding toward new definition and novel therapeutic approaches. Diverse clinical manifestations and outcomes among infectious patients have suggested the heterogeneity of immunopathology, while systemic inflammatory responses and deteriorating organ function observed in critically ill patients imply the extensively hyperactivated cascades by the host defense system. From focusing on microorganism pathogenicity, research interests have turned toward the molecular basis of host responses. Though progress has been made regarding recognition and management of clinical sepsis, incidence and mortality rate remain high. Furthermore, clinical trials of therapeutics have failed to obtain promising results. As far as we know, there was no systematic review addressing sepsis-related molecular signaling pathways and intervention therapy in literature. Increasing studies have succeeded to confirm novel functions of involved signaling pathways and comment on efficacy of intervention therapies amid sepsis. However, few of these studies attempt to elucidate the underlining mechanism in progression of sepsis, while other failed to integrate preliminary findings and describe in a broader view. This review focuses on the important signaling pathways, potential molecular mechanism, and pathway-associated therapy in sepsis. Host-derived molecules interacting with activated cells possess pivotal role for sepsis pathogenesis by dynamic regulation of signaling pathways. Cross-talk and functions of these molecules are also discussed in detail. Lastly, potential novel therapeutic strategies precisely targeting on signaling pathways and molecules are mentioned.
Collapse
Affiliation(s)
- Yun-Yu Zhang
- Department of Pediatric Intensive Care Unit, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 200127, Shanghai, China
| | - Bo-Tao Ning
- Department of Pediatric Intensive Care Unit, Shanghai Children's Medical Center, School of Medicine, Shanghai Jiao Tong University, 200127, Shanghai, China.
| |
Collapse
|
5
|
Kitsiouli E, Tenopoulou M, Papadopoulos S, Lekka ME. Phospholipases A2 as biomarkers in ARDS. Biomed J 2021; 44:663-670. [PMID: 34478892 PMCID: PMC8847824 DOI: 10.1016/j.bj.2021.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 07/16/2021] [Accepted: 08/23/2021] [Indexed: 02/06/2023] Open
Abstract
Acute respiratory distress syndrome (ARDS) is a multifactorial life-threatening lung injury, characterized by diffuse lung inflammation and increased alveolocapillary barrier permeability. The different stages of ARDS have distinctive biochemical and clinical profiles. Despite the progress of our understanding on ARDS pathobiology, the mechanisms underlying its pathogenesis are still obscure. Herein, we review the existing literature about the implications of phospholipases 2 (PLA2s), a large family of enzymes that catalyze the hydrolysis of fatty acids at the sn-2 position of glycerophospholipids, in ARDS-related pathology. We emphasize on the versatile way of participation of different PLA2s isoforms in the distinct ARDS subgroup phenotypes by either potentiating lung inflammation and damage or by preserving the normal lung. Current research supports that PLA2s are associated with the progression and the outcome of ARDS. We herein discuss the transcellular communication of PLA2s through secreted extracellular vesicles and suggest it as a new mechanism of PLA2s involvement in ARDS. Thus, the elucidation of the spatiotemporal features of PLA2s expression may give new insights and provide valuable information about the risk of an individual to develop ARDS or advance to more severe stages, and potentially identify PLA2 isoforms as biomarkers and target for pharmacological intervention.
Collapse
Affiliation(s)
- Eirini Kitsiouli
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Margarita Tenopoulou
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Stylianos Papadopoulos
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece
| | - Marilena E Lekka
- Laboratory of Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, Greece.
| |
Collapse
|
6
|
The roles of platelets in COVID-19-associated coagulopathy and vaccine-induced immune thrombotic thrombocytopenia. Trends Cardiovasc Med 2021; 32:1-9. [PMID: 34455073 PMCID: PMC8390120 DOI: 10.1016/j.tcm.2021.08.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 08/06/2021] [Accepted: 08/23/2021] [Indexed: 02/07/2023]
Abstract
In coronavirus disease 2019 (COVID-19), multiple thromboinflammatory events contribute to the pathophysiology, including coagulation system activation, suppressed fibrinolysis, vascular endothelial cell injury, and prothrombotic alterations in immune cells such as macrophages and neutrophils. Although thrombocytopenia is not an initial presentation as an infectious coagulopathy, recent studies have demonstrated the vital role of platelets in COVID-19-associated coagulopathy SARS-CoV-2 and its spike protein have been known to directly or indirectly promote release of prothrombotic and inflammatory mediators that lead to COVID-19-associated coagulopathy. Although clinical features of vaccine-induced immune thrombotic thrombocytopenia include uncommon locations of thrombosis, including cerebral venous sinus, we speculate coronavirus spike-protein-initiated prothrombotic pathways are involved in the pathogenesis of vaccine-induced immune thrombotic thrombocytopenia, as current evidence suggests that the spike protein is the promotor and other cofactors such as perturbed immune response and inflammatory reaction enhance the production of anti-platelet factor 4 antibody.
Collapse
|
7
|
Amunugama K, Pike DP, Ford DA. The lipid biology of sepsis. J Lipid Res 2021; 62:100090. [PMID: 34087197 PMCID: PMC8243525 DOI: 10.1016/j.jlr.2021.100090] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 01/12/2023] Open
Abstract
Sepsis, defined as the dysregulated immune response to an infection leading to organ dysfunction, is one of the leading causes of mortality around the globe. Despite the significant progress in delineating the underlying mechanisms of sepsis pathogenesis, there are currently no effective treatments or specific diagnostic biomarkers in the clinical setting. The perturbation of cell signaling mechanisms, inadequate inflammation resolution, and energy imbalance, all of which are altered during sepsis, are also known to lead to defective lipid metabolism. The use of lipids as biomarkers with high specificity and sensitivity may aid in early diagnosis and guide clinical decision making. In addition, identifying the link between specific lipid signatures and their role in sepsis pathology may lead to novel therapeutics. In this review, we discuss the recent evidence on dysregulated lipid metabolism both in experimental and human sepsis focused on bioactive lipids, fatty acids, and cholesterol as well as the enzymes regulating their levels during sepsis. We highlight not only their potential roles in sepsis pathogenesis but also the possibility of using these respective lipid compounds as diagnostic and prognostic biomarkers of sepsis.
Collapse
Affiliation(s)
- Kaushalya Amunugama
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA; Center for Cardiovascular Research, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Daniel P Pike
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA; Center for Cardiovascular Research, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - David A Ford
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO, USA; Center for Cardiovascular Research, Saint Louis University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
8
|
Barker G, Leeuwenburgh C, Brusko T, Moldawer L, Reddy ST, Guirgis FW. Lipid and Lipoprotein Dysregulation in Sepsis: Clinical and Mechanistic Insights into Chronic Critical Illness. J Clin Med 2021; 10:1693. [PMID: 33920038 PMCID: PMC8071007 DOI: 10.3390/jcm10081693] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/05/2021] [Accepted: 04/12/2021] [Indexed: 12/12/2022] Open
Abstract
In addition to their well-characterized roles in metabolism, lipids and lipoproteins have pleiotropic effects on the innate immune system. These undergo clinically relevant alterations during sepsis and acute inflammatory responses. High-density lipoprotein (HDL) plays an important role in regulating the immune response by clearing bacterial toxins, supporting corticosteroid release, decreasing platelet aggregation, inhibiting endothelial cell apoptosis, reducing the monocyte inflammatory response, and inhibiting expression of endothelial cell adhesion molecules. It undergoes quantitative as well as qualitative changes which can be measured using the HDL inflammatory index (HII). Pro-inflammatory, or dysfunctional HDL (dysHDL) lacks the ability to perform these functions, and we have also found it to independently predict adverse outcomes and organ failure in sepsis. Another important class of lipids known as specialized pro-resolving mediators (SPMs) positively affect the escalation and resolution of inflammation in a temporal fashion. These undergo phenotypic changes in sepsis and differ significantly between survivors and non-survivors. Certain subsets of sepsis survivors go on to have perilous post-hospitalization courses where this inflammation continues in a low grade fashion. This is associated with immunosuppression in a syndrome of persistent inflammation, immunosuppression, and catabolism syndrome (PICS). The continuous release of tissue damage-related patterns and viral reactivation secondary to immunosuppression feed this chronic cycle of inflammation. Animal data indicate that dysregulation of endogenous lipids and SPMs play important roles in this process. Lipids and their associated pathways have been the target of many clinical trials in recent years which have not shown mortality benefit. These results are limited by patient heterogeneity and poor animal models. Considerations of sepsis phenotypes and novel biomarkers in future trials are important factors to be considered in future research. Further characterization of lipid dysregulation and chronic inflammation during sepsis will aid mortality risk stratification, detection of sepsis, and inform individualized pharmacologic therapies.
Collapse
Affiliation(s)
- Grant Barker
- Department of Emergency Medicine, College of Medicine-Jacksonville, University of Florida, 655 West 8th Street, Jacksonville, FL 32209, USA;
| | - Christiaan Leeuwenburgh
- Department of Aging and Geriatric Research, College of Medicine, University of Florida, Gainesville, FL 32603, USA;
| | - Todd Brusko
- Department of Pathology, Immunology and Laboratory Medicine, College of Medicine, University of Florida Diabetes Institute, Gainesville, FL 32610, USA;
| | - Lyle Moldawer
- Department of Surgery, College of Medicine, University of Florida, Gainesville, FL 32608, USA;
| | - Srinivasa T. Reddy
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA;
| | - Faheem W. Guirgis
- Department of Emergency Medicine, College of Medicine-Jacksonville, University of Florida, 655 West 8th Street, Jacksonville, FL 32209, USA;
| |
Collapse
|
9
|
Hug S, Bernhard S, Stratmann AEP, Erber M, Wohlgemuth L, Knapp CL, Bauer JM, Vidoni L, Fauler M, Föhr KJ, Radermacher P, Hoffmann A, Huber-Lang M, Messerer DAC. Activation of Neutrophil Granulocytes by Platelet-Activating Factor Is Impaired During Experimental Sepsis. Front Immunol 2021; 12:642867. [PMID: 33796110 PMCID: PMC8007865 DOI: 10.3389/fimmu.2021.642867] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/15/2021] [Indexed: 11/13/2022] Open
Abstract
Platelet-activating factor (PAF) is an important mediator of the systemic inflammatory response. In the case of sepsis, proper activation and function of neutrophils as the first line of cellular defense are based on a well-balanced physiological response. However, little is known about the role of PAF in cellular changes of neutrophils during sepsis. Therefore, this study investigates the reaction patterns of neutrophils induced by PAF with a focus on membrane potential (MP), intracellular pH, and cellular swelling under physiological and pathophysiological conditions and hypothesizes that the PAF-mediated response of granulocytes is altered during sepsis. The cellular response of granulocytes including MP, intracellular pH, cellular swelling, and other activation markers were analyzed by multiparametric flow cytometry. In addition, the chemotactic activity and the formation of platelet-neutrophil complexes after exposure to PAF were investigated. The changes of the (electro-)physiological response features were translationally verified in a human ex vivo whole blood model of endotoxemia as well as during polymicrobial porcine sepsis. In neutrophils from healthy human donors, PAF elicited a rapid depolarization, an intracellular alkalization, and an increase in cell size in a time- and dose-dependent manner. Mechanistically, the alkalization was dependent on sodium-proton exchanger 1 (NHE1) activity, while the change in cellular shape was sodium flux- but only partially NHE1-dependent. In a pathophysiological altered environment, the PAF-induced response of neutrophils was modulated. Acidifying the extracellular pH in vitro enhanced PAF-mediated depolarization, whereas the increases in cell size and intracellular pH were largely unaffected. Ex vivo exposure of human whole blood to lipopolysaccharide diminished the PAF-induced intracellular alkalization and the change in neutrophil size. During experimental porcine sepsis, depolarization of the MP was significantly impaired. Additionally, there was a trend for increased cellular swelling, whereas intracellular alkalization remained stable. Overall, an impaired (electro-)physiological response of neutrophils to PAF stimulation represents a cellular hallmark of those cells challenged during systemic inflammation. Furthermore, this altered response may be indicative of and causative for the development of neutrophil dysfunction during sepsis.
Collapse
Affiliation(s)
- Stefan Hug
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Stefan Bernhard
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | | | - Maike Erber
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Lisa Wohlgemuth
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Christiane Leonie Knapp
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Jonas Martin Bauer
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Laura Vidoni
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Michael Fauler
- Institute of General Physiology, University of Ulm, Ulm, Germany
| | - Karl Josef Föhr
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Ulm, Ulm, Germany
| | - Peter Radermacher
- Institute of Anesthesiological Pathophysiology and Process Development, University Hospital of Ulm, Ulm, Germany
| | - Andrea Hoffmann
- Institute of Anesthesiological Pathophysiology and Process Development, University Hospital of Ulm, Ulm, Germany
| | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - David Alexander Christian Messerer
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany.,Department of Anesthesiology and Intensive Care Medicine, University Hospital of Ulm, Ulm, Germany.,Institute of Anesthesiological Pathophysiology and Process Development, University Hospital of Ulm, Ulm, Germany
| |
Collapse
|
10
|
Busani S, Roat E, Tosi M, Biagioni E, Coloretti I, Meschiari M, Gelmini R, Brugioni L, De Biasi S, Girardis M. Adjunctive Immunotherapy With Polyclonal Ig-M Enriched Immunoglobulins for Septic Shock: From Bench to Bedside. The Rationale for a Personalized Treatment Protocol. Front Med (Lausanne) 2021; 8:616511. [PMID: 33681248 PMCID: PMC7930614 DOI: 10.3389/fmed.2021.616511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 01/27/2021] [Indexed: 01/19/2023] Open
Abstract
Septic shock still has a high mortality rate which has not hinted at decreasing in recent years. Unfortunately, randomized trials failed mainly because the septic patient was considered as a homogeneous entity. All this creates a sort of therapeutic impotence in everyday clinical practice in treating patients with septic shock. The need to customize therapy on each patient with sepsis has now become an established necessity. In this scenario, adjuvant therapies can help if interpreted as modulators of the immune system. Indeed, the host's immune response differs from patient to patient based on the virulence of the pathogen, comorbidity, infection site, and prolonged hospitalization. In this review, we summarize the rationale for using immunoglobulins as an adjunctive treatment. Furthermore, we would like to suggest a possible protocol to personalize treatment in the different clinical scenarios of the host's response to serious infectious events.
Collapse
Affiliation(s)
- Stefano Busani
- Intensive Care Unit, University Hospital Policlinico di Modena, University of Modena and Reggio Emilia, Modena, Italy
| | - Erika Roat
- Intensive Care Unit, University Hospital Policlinico di Modena, University of Modena and Reggio Emilia, Modena, Italy
| | - Martina Tosi
- Intensive Care Unit, University Hospital Policlinico di Modena, University of Modena and Reggio Emilia, Modena, Italy
| | - Emanuela Biagioni
- Intensive Care Unit, University Hospital Policlinico di Modena, University of Modena and Reggio Emilia, Modena, Italy
| | - Irene Coloretti
- Intensive Care Unit, University Hospital Policlinico di Modena, University of Modena and Reggio Emilia, Modena, Italy
| | - Marianna Meschiari
- Infectious Diseases Unit, University Hospital Policlinico di Modena, University of Modena and Reggio Emilia, Modena, Italy
| | - Roberta Gelmini
- Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Lucio Brugioni
- Internal Medicine Department, Azienda Ospedaliero-Universitaria Policlinico of Modena, Modena, Italy
| | - Sara De Biasi
- Department of Medical and Surgical Sciences for Children and Adults, University of Modena and Reggio Emilia School of Medicine, Modena, Italy
| | - Massimo Girardis
- Intensive Care Unit, University Hospital Policlinico di Modena, University of Modena and Reggio Emilia, Modena, Italy
| |
Collapse
|
11
|
Marathe GK, Chaithra VH, Ke LY, Chen CH. Effect of acyl and alkyl analogs of platelet-activating factor on inflammatory signaling. Prostaglandins Other Lipid Mediat 2020; 151:106478. [PMID: 32711129 DOI: 10.1016/j.prostaglandins.2020.106478] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 01/11/2023]
Abstract
Platelet-activating factor (PAF), a bioactive ether phospholipid with significant pro-inflammatory properties, was identified almost half a century ago. Despite extensive study of this autocoid, therapeutic strategies for targeting its signaling components have not been successful, including the recent clinical trials with darapladib, a drug that targets plasma PAF-acetylhydrolase (PAF-AH). We recently provided experimental evidence that the previously unrecognized acyl analog of PAF, which is concomitantly produced along with PAF during biosynthesis, dampens PAF signaling by acting both as a sacrificial substrate for PAF-AH and probably as an endogenous PAF-receptor antagonist/partial agonist. If this is the scenario in vivo, PAF-AH needs to catalyze the selective hydrolysis of alkyl-PAF and not acyl-PAF. Accordingly, different approaches are needed for treating inflammatory diseases in which PAF signaling is implicated. The interplay between acyl-PAF, alkyl-PAF, PAF-AH, and PAF-R is complex, and the outcome of this interplay has not been previously appreciated. In this review, we discuss this interaction based on our recent findings. It is very likely that the relative abundance of acyl and alkyl-PAF and their interactions with PAF-R in the presence of their hydrolyzing enzyme PAF-AH may exert a modulatory effect on PAF signaling during inflammation.
Collapse
Affiliation(s)
- Gopal Kedihithlu Marathe
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysuru, 570006, Karnataka, India; Department of Studies in Molecular Biology, University of Mysore, Manasagangothri, Mysuru, 570006, Karnataka, India.
| | | | - Liang-Yin Ke
- College of Health Sciences, Kaohsiung Medical University, Vascular and Medicinal Research, Kaohsiung, 80708, Taiwan.
| | - Chu-Huang Chen
- Vascular and Medicinal Research, Texas Heart Institute, Houston, Texas 77030, USA.
| |
Collapse
|
12
|
Nowill AE, de Campos-Lima PO. Immune Response Resetting as a Novel Strategy to Overcome SARS-CoV-2-Induced Cytokine Storm. THE JOURNAL OF IMMUNOLOGY 2020; 205:2566-2575. [PMID: 32958687 DOI: 10.4049/jimmunol.2000892] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 08/30/2020] [Indexed: 12/15/2022]
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (COVID-19), which rapidly became a pandemic of global proportions. Sepsis is commonly present with high lethality in the severe forms of the disease. The virus-induced cytokine storm puts the immune system in overdrive at the expense of the pathogen-specific immune response and is likely to underlie the most advanced COVID-19 clinical features, including sepsis-related multiple organ dysfunction as well as the pathophysiological changes found in the lungs. We review the major therapeutic strategies that have been considered for sepsis and might be amenable to repurposing for COVID-19. We also discuss two different immunization strategies that have the potential to confer antiviral heterologous protection: innate-induced trained immunity and adaptive-induced immune response resetting.
Collapse
Affiliation(s)
- Alexandre E Nowill
- Integrated Center for Pediatric OncoHaematological Research, State University of Campinas, Campinas SP 13083-888, Brazil;
| | - Pedro O de Campos-Lima
- Boldrini Children's Center, Campinas SP 13083-210, Brazil; and .,Functional and Molecular Biology Graduate Program, Institute of Biology, State University of Campinas, Campinas SP 13083-865, Brazil
| |
Collapse
|
13
|
Rehman A, Baloch NUA, Morrow JP, Pacher P, Haskó G. Targeting of G-protein coupled receptors in sepsis. Pharmacol Ther 2020; 211:107529. [PMID: 32197794 PMCID: PMC7388546 DOI: 10.1016/j.pharmthera.2020.107529] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 12/11/2022]
Abstract
The Third International Consensus Definitions (Sepsis-3) define sepsis as life-threatening multi-organ dysfunction caused by a dysregulated host response to infection. Sepsis can progress to septic shock-an even more lethal condition associated with profound circulatory, cellular and metabolic abnormalities. Septic shock remains a leading cause of death in intensive care units and carries a mortality of almost 25%. Despite significant advances in our understanding of the pathobiology of sepsis, therapeutic interventions have not translated into tangible differences in the overall outcome for patients. Clinical trials of antagonists of various pro-inflammatory mediators in sepsis have been largely unsuccessful in the past. Given the diverse physiologic roles played by G-protein coupled receptors (GPCR), modulation of GPCR signaling for the treatment of sepsis has also been explored. Traditional pharmacologic approaches have mainly focused on ligands targeting the extracellular domains of GPCR. However, novel techniques aimed at modulating GPCR intracellularly through aptamers, pepducins and intrabodies have opened a fresh avenue of therapeutic possibilities. In this review, we summarize the diverse roles played by various subfamilies of GPCR in the pathogenesis of sepsis and identify potential targets for pharmacotherapy through these novel approaches.
Collapse
Affiliation(s)
- Abdul Rehman
- Department of Medicine, Rutgers-New Jersey Medical School, Newark, NJ, United States
| | - Noor Ul-Ain Baloch
- Department of Medicine, Rutgers-New Jersey Medical School, Newark, NJ, United States
| | - John P Morrow
- Department of Medicine, Columbia University, New York City, NY, United States
| | - Pál Pacher
- Laboratory of Cardiovascular Physiology and Tissue Injury, National Institutes of Health, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, United States
| | - György Haskó
- Department of Anesthesiology, Columbia University, New York City, NY, United States.
| |
Collapse
|
14
|
Yi L, Zhang J, Zhong J, Zheng Y. Elevated Levels of Platelet Activating Factor and Its Acetylhydrolase Indicate High Risk of Kawasaki Disease. J Interferon Cytokine Res 2020; 40:159-167. [PMID: 31841639 DOI: 10.1089/jir.2019.0141] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Lunyu Yi
- Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Pediatrics, Chongqing, P. R. China
| | - Jing Zhang
- Department of Pediatrics, China Japan Friendship Hospital, Beijing, P. R. China
| | - Jiarong Zhong
- Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Pediatrics, Chongqing, P. R. China
| | - Yuqiang Zheng
- Ministry of Education Key Laboratory of Child Development and Disorders, National Clinical Research Center for Child Health and Disorders, China International Science and Technology Cooperation Base of Child Development and Critical Disorders, Children's Hospital of Chongqing Medical University, Chongqing Key Laboratory of Pediatrics, Chongqing, P. R. China
| |
Collapse
|
15
|
Silva PL, Pelosi P, Rocco PRM. Personalized pharmacological therapy for ARDS: a light at the end of the tunnel. Expert Opin Investig Drugs 2019; 29:49-61. [PMID: 31778609 DOI: 10.1080/13543784.2020.1699531] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Introduction: Pharmacotherapy for the acute respiratory distress syndrome (ARDS) has been tested in preclinical and clinical studies. However, to date, no pharmacological interventions have proven effective. This may be attributed to lack of proper identification of different ARDS phenotypes.Areas covered: We designed inclusive search strings and searched four bibliographic databases (Cochrane Database of Systematic Reviews, PubMed, Web of Science, and clinicaltrials.gov) to identify relevant research. Search results were mainly restricted to papers published from 2009 through 2019. ARDS is a heterogeneous syndrome, and its different phenotypes - defined according to clinical, radiological, and biological parameters - may affect response to therapy. The most promising pharmacological approaches to date have been based on ARDS pathophysiology. They focus on reducing inflammation and pulmonary edema, promoting selective vasodilation, and repairing alveolar epithelial and endothelial cells.Expert opinion: Pharmacotherapeutic approaches targeting ARDS pathophysiology have failed to exert beneficial effects. Personalized medicine targeting the different ARDS phenotypes has emerged as an option to improve survival. Identification of specific ARDS patient phenotypes that respond to specific therapies seems to be the most important challenge for the next decade. Additional research is warranted before personalized medicine approaches can be applied at bedside for ARDS patients.
Collapse
Affiliation(s)
- Pedro Leme Silva
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
| | - Paolo Pelosi
- Department of Surgical Sciences and Integrated Diagnostics (DISC), University of Genoa, Genoa, Italy.,IRCCS for Oncology and Neurosciences, San Martino Policlinico Hospital, Genoa, Italy
| | - Patricia R M Rocco
- Laboratory of Pulmonary Investigation, Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Centro de Ciências da Saúde, Rio de Janeiro, Brazil
| |
Collapse
|
16
|
Which Multicenter Randomized Controlled Trials in Critical Care Medicine Have Shown Reduced Mortality? A Systematic Review. Crit Care Med 2019; 47:1680-1691. [DOI: 10.1097/ccm.0000000000004000] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
17
|
Re-Evaluating Biologic Pharmacotherapies that Target the Host Response during Sepsis. Int J Mol Sci 2019; 20:ijms20236049. [PMID: 31801287 PMCID: PMC6929091 DOI: 10.3390/ijms20236049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/18/2019] [Accepted: 11/26/2019] [Indexed: 02/04/2023] Open
Abstract
Multiple organ dysfunction syndrome (MODS) caused by the systemic inflammatory response during sepsis is responsible for millions of deaths worldwide each year, and despite broad consensus concerning its pathophysiology, no specific or effective therapies exist. Recent efforts to treat and/or prevent MODS have included a variety of biologics, recombinant proteins targeting various components of the host response to the infection (e.g., inflammation, coagulation, etc.) Improvements in molecular biology and pharmaceutical engineering have enabled a wide range of utility for biologics to target various aspects of the systemic inflammatory response. The majority of clinical trials to date have failed to show clinical benefit, but some have demonstrated promising results in certain patient populations. In this review we summarize the underlying rationale and outcome of major clinical trials where biologics have been tested as a pharmacotherapy for MODS in sepsis. A brief description of the study design and overall outcome for each of the major trials are presented. Emphasis is placed on discussing targets and/or trials where promising results were observed. Post hoc analyses of trials where therapy demonstrated harm or additional risk to certain patient subgroups are highlighted, and details are provided about specific trials where more stringent inclusion/exclusion criteria are warranted.
Collapse
|
18
|
Iba T, Levy JH, Raj A, Warkentin TE. Advance in the Management of Sepsis-Induced Coagulopathy and Disseminated Intravascular Coagulation. J Clin Med 2019; 8:E728. [PMID: 31121897 PMCID: PMC6572234 DOI: 10.3390/jcm8050728] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 05/17/2019] [Accepted: 05/20/2019] [Indexed: 12/18/2022] Open
Abstract
Coagulopathy commonly occurs in sepsis as a critical host response to infection that can progress to disseminated intravascular coagulation (DIC) with an increased mortality. Recent studies have further defined factors responsible for the thromboinflammatory response and intravascular thrombosis, including neutrophil extracellular traps, extracellular vesicles, damage-associated molecular patterns, and endothelial glycocalyx shedding. Diagnosing DIC facilitates sepsis management, and is associated with improved outcomes. Although the International Society on Thrombosis and Haemostasis (ISTH) has proposed criteria for diagnosing overt DIC, these criteria are not suitable for early detection. Accordingly, the ISTH DIC Scientific Standardization Committee has proposed a new category termed "sepsis-induced coagulopathy (SIC)" to facilitate earlier diagnosis of DIC and potentially more rapid interventions in these critically ill patients. Therapy of SIC includes both treatment of the underlying infection and correcting the coagulopathy, with most therapeutic approaches focusing on anticoagulant therapy. Recently, a phase III trial of recombinant thrombomodulin was performed in coagulopathic patients. Although the 28-day mortality was improved by 2.6% (absolute difference), it did not reach statistical significance. However, in patients who met entry criteria for SIC at baseline, the mortality difference was approximately 5% without increased risk of bleeding. In this review, we discuss current advances in managing SIC and DIC.
Collapse
Affiliation(s)
- Toshiaki Iba
- Department of Emergency and Disaster Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo Bunkyo-ku, Tokyo 113-8421, Japan.
| | - Jerrold H Levy
- Department of Anesthesiology, Critical Care, and Surgery, Duke University School of Medicine, Durham, NC 27705, USA.
| | - Aditya Raj
- Department of Emergency and Disaster Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Hongo Bunkyo-ku, Tokyo 113-8421, Japan.
- Imperial College London, South Kensington, London SW7 2AZ, UK.
| | - Theodore E Warkentin
- Department of Pathology and Molecular Medicine, and Department of Medicine, McMaster University, 1280 Main Street West, Hamilton, ON L8S4L8, Canada.
| |
Collapse
|
19
|
Yagnik D, Hills F. Urate crystals induce macrophage PAF‑AH secretion which is differentially regulated by TGFβ1 and hydrocortisone. Mol Med Rep 2018; 18:3506-3512. [DOI: 10.3892/mmr.2018.9323] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 06/13/2018] [Indexed: 11/06/2022] Open
Affiliation(s)
- Darshna Yagnik
- Department of Natural Sciences, Biomarker Research Group, School of Science and Technology, Middlesex University, The Burroughs, London NW4 4BT, UK
| | - Frank Hills
- Department of Natural Sciences, Biomarker Research Group, School of Science and Technology, Middlesex University, The Burroughs, London NW4 4BT, UK
| |
Collapse
|
20
|
Jiang W, Yu X, Sun T, Chai Y, Chang P, Chen Z, Pan J, Peng Z, Wang R, Wang X, Xu Y, Yu L, Zheng Q, Du B. ADJunctive Ulinastatin in Sepsis Treatment in China (ADJUST study): study protocol for a randomized controlled trial. Trials 2018; 19:133. [PMID: 29467017 PMCID: PMC5822617 DOI: 10.1186/s13063-018-2513-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 01/30/2018] [Indexed: 12/29/2022] Open
Abstract
Background Sepsis is a major challenge in critical care and is associated with high mortality. Current management of sepsis and septic shock remains mainly supportive. Both basic and clinical research has shown that ulinastatin can improve the prognosis of sepsis. The aim of this trial is to evaluate the efficacy and safety profiles of ulinastatin compared with placebo. Methods/design In this multi-center, double-blind, randomized placebo-controlled trial we are recruiting a total of 348 subjects meeting “The Third International Consensus Definitions for Sepsis and Septic Shock” (Sepsis-3). Subjects will be randomized (1:1) to receive ulinastatin 400,000 IU three times a day for 10 days or matching placebo and usual care simultaneously. The primary outcome is 28-day all-cause mortality. Adverse events and serious adverse events will be monitored closely. Discussion ADJUST is a large, multi-center, double-blind, randomized, parallel-group, placebo-controlled trial of ulinastatin in mainland China and is well-designed on the basis of previous studies. The results of this trial may help to provide evidence-based recommendations for treatment of sepsis. Trial registration ClinicalTrials.gov, ID: NCT02647554. First registered on 27 December 2015, and last verified in December of 2016. Protocol version: 2.1, verified on 19 July 2016.
Collapse
Affiliation(s)
- Wei Jiang
- Medical Intensive Care Unit, Peking Union Medical College Hospital, 1 Shuai Fu Yuan, Beijing, 100730, China
| | - Xiangyou Yu
- Department of Critical Care Medicine, Xinjiang Medical University 1st Hospital, Urumqi, Xinjiang, China
| | - Tongwen Sun
- Department of General Intensive Care Unit, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
| | - Yanfen Chai
- Department of Emergency, Tianjin Medical University General Hospital, Tianjin, China
| | - Ping Chang
- Department of Critical Care Medicine, Zhujiang Hospital of Southern Medical University, Guangzhou, Guangdong, China
| | - Zhongqing Chen
- Department of Critical Care Medicine, Nanfang Hospital of Southern Medical University, Guangzhou, Guangdong, China
| | - Jingye Pan
- Department of Critical Care Medicine, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zhiyong Peng
- Department of Critical Care Medicine, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, China
| | - Ruilan Wang
- Department of Critical Care Medicine, First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China
| | - Xiaozhi Wang
- Department of Critical Care Medicine, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Yuan Xu
- Department of Critical Care Medicine, Beijing Tsinghua Changgung Hospital Affiliated to Tsinghua University, Beijing, China
| | - Li Yu
- Department of Critical Care Medicine, the Central Hospital of Wuhan Affiliated to Tongji Medical College Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Qingshan Zheng
- Centre for Drug Clinical Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Bin Du
- Medical Intensive Care Unit, Peking Union Medical College Hospital, 1 Shuai Fu Yuan, Beijing, 100730, China.
| | | |
Collapse
|
21
|
Iba T, Levy JH. Inflammation and thrombosis: roles of neutrophils, platelets and endothelial cells and their interactions in thrombus formation during sepsis. J Thromb Haemost 2018; 16:231-241. [PMID: 29193703 DOI: 10.1111/jth.13911] [Citation(s) in RCA: 327] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Indexed: 12/12/2022]
Abstract
The inflammatory response and the activation of coagulation are two important responses in a host's defense against infection. These mechanisms do not work independently, but cooperate in a complex and synchronous manner. Recent research has also shed light on the critical role of thrombus formation, which prevents the dissemination of microorganisms. The cellular components of blood vessels, i.e. leukocytes, platelets, erythrocytes, and vascular endothelial cells, play significant roles in the development of thrombi in combination with activation of the coagulation system. In addition to the cellular components, alarmins such as histones and high-mobility group box 1, microparticles and secreted granule proteins are all important for clot formation. In this summary, we review the pathophysiology of sepsis-induced coagulopathy and the role of cellular components and critical factors released from damaged cells. In addition, we review important therapeutic approaches that have been developed, are under investigation and are currently available in certain countries, including antithrombin, recombinant thrombomodulin, anti-Toll-like receptor 4 therapy, anti-damage associated molecular pattern therapy, and hemoadsorption with a polymyxin B-immobilized fiber column.
Collapse
Affiliation(s)
- T Iba
- Department of Emergency and Disaster Medicine, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - J H Levy
- Department of Anesthesiology and Surgery, Duke University School of Medicine, Durham, NC, USA
| |
Collapse
|
22
|
Lakshmikanth CL, Jacob SP, Chaithra VH, de Castro-Faria-Neto HC, Marathe GK. Sepsis: in search of cure. Inflamm Res 2016; 65:587-602. [PMID: 26995266 DOI: 10.1007/s00011-016-0937-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 02/23/2016] [Accepted: 02/29/2016] [Indexed: 12/16/2022] Open
Abstract
INTRODUCTION Sepsis is a complex inflammatory disorder believed to originate from an infection by any types of microbes and/or their products. It is the leading cause of death in intensive care units (ICUs) throughout the globe. The mortality rates depend both on the severity of infection and the host's response to infection. METHODS Literature survey on pathobiology of sepsis in general and failure of more than hundred clinical trials conducted so far in search of a possible cure for sepsis resulted in the preparation of this manuscript. FINDINGS Sepsis lacks a suitable animal model that mimics human sepsis. However, based on the results obtained in animal models of sepsis, clinical trials conducted so far have been disappointing. Although involvement of multiple mediators and pathways in sepsis has been recognized, only few components are being targeted and this could be the major reason behind the failure of clinical trials. CONCLUSION Inability to recognize a single critical mediator of sepsis may be the underlying cause for the poor therapeutic intervention of sepsis. Therefore, sepsis is still considered as a disease-in search of cure.
Collapse
Affiliation(s)
| | - Shancy Petsel Jacob
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore, 570 006, India
| | | | | | - Gopal Kedihithlu Marathe
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore, 570 006, India.
| |
Collapse
|
23
|
A Molecular Host Response Assay to Discriminate Between Sepsis and Infection-Negative Systemic Inflammation in Critically Ill Patients: Discovery and Validation in Independent Cohorts. PLoS Med 2015; 12:e1001916. [PMID: 26645559 PMCID: PMC4672921 DOI: 10.1371/journal.pmed.1001916] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 10/29/2015] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Systemic inflammation is a whole body reaction having an infection-positive (i.e., sepsis) or infection-negative origin. It is important to distinguish between these two etiologies early and accurately because this has significant therapeutic implications for critically ill patients. We hypothesized that a molecular classifier based on peripheral blood RNAs could be discovered that would (1) determine which patients with systemic inflammation had sepsis, (2) be robust across independent patient cohorts, (3) be insensitive to disease severity, and (4) provide diagnostic utility. The goal of this study was to identify and validate such a molecular classifier. METHODS AND FINDINGS We conducted an observational, non-interventional study of adult patients recruited from tertiary intensive care units (ICUs). Biomarker discovery utilized an Australian cohort (n = 105) consisting of 74 cases (sepsis patients) and 31 controls (post-surgical patients with infection-negative systemic inflammation) recruited at five tertiary care settings in Brisbane, Australia, from June 3, 2008, to December 22, 2011. A four-gene classifier combining CEACAM4, LAMP1, PLA2G7, and PLAC8 RNA biomarkers was identified. This classifier, designated SeptiCyte Lab, was validated using reverse transcription quantitative PCR and receiver operating characteristic (ROC) curve analysis in five cohorts (n = 345) from the Netherlands. Patients for validation were selected from the Molecular Diagnosis and Risk Stratification of Sepsis study (ClinicalTrials.gov, NCT01905033), which recruited ICU patients from the Academic Medical Center in Amsterdam and the University Medical Center Utrecht. Patients recruited from November 30, 2012, to August 5, 2013, were eligible for inclusion in the present study. Validation cohort 1 (n = 59) consisted entirely of unambiguous cases and controls; SeptiCyte Lab gave an area under curve (AUC) of 0.95 (95% CI 0.91-1.00) in this cohort. ROC curve analysis of an independent, more heterogeneous group of patients (validation cohorts 2-5; 249 patients after excluding 37 patients with an infection likelihood of "possible") gave an AUC of 0.89 (95% CI 0.85-0.93). Disease severity, as measured by Sequential Organ Failure Assessment (SOFA) score or Acute Physiology and Chronic Health Evaluation (APACHE) IV score, was not a significant confounding variable. The diagnostic utility of SeptiCyte Lab was evaluated by comparison to various clinical and laboratory parameters available to a clinician within 24 h of ICU admission. SeptiCyte Lab was significantly better at differentiating cases from controls than all tested parameters, both singly and in various logistic combinations, and more than halved the diagnostic error rate compared to procalcitonin in all tested cohorts and cohort combinations. Limitations of this study relate to (1) cohort compositions that do not perfectly reflect the composition of the intended use population, (2) potential biases that could be introduced as a result of the current lack of a gold standard for diagnosing sepsis, and (3) lack of a complete, unbiased comparison to C-reactive protein. CONCLUSIONS SeptiCyte Lab is a rapid molecular assay that may be clinically useful in managing ICU patients with systemic inflammation. Further study in population-based cohorts is needed to validate this assay for clinical use.
Collapse
|
24
|
Que YA, Guessous I, Dupuis-Lozeron E, de Oliveira CRA, Oliveira CF, Graf R, Seematter G, Revelly JP, Pagani JL, Liaudet L, Nobre V, Eggimann P. Prognostication of Mortality in Critically Ill Patients With Severe Infections. Chest 2015; 148:674-682. [PMID: 26065577 DOI: 10.1378/chest.15-0123] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The purpose of this study was to confirm the prognostic value of pancreatic stone protein (PSP) in patients with severe infections requiring ICU management and to develop and validate a model to enhance mortality prediction by combining severity scores with biomarkers. METHODS We enrolled prospectively patients with severe sepsis or septic shock in mixed tertiary ICUs in Switzerland (derivation cohort) and Brazil (validation cohort). Severity scores (APACHE [Acute Physiology and Chronic Health Evaluation] II or Simplified Acute Physiology Score [SAPS] II) were combined with biomarkers obtained at the time of diagnosis of sepsis, including C-reactive-protein, procalcitonin (PCT), and PSP. Logistic regression models with the lowest prediction errors were selected to predict in-hospital mortality. RESULTS Mortality rates of patients with septic shock enrolled in the derivation cohort (103 out of 158) and the validation cohort (53 out of 91) were 37% and 57%, respectively. APACHE II and PSP were significantly higher in dying patients. In the derivation cohort, the models combining either APACHE II, PCT, and PSP (area under the receiver operating characteristic curve [AUC], 0.721; 95% CI, 0.632-0.812) or SAPS II, PCT, and PSP (AUC, 0.710; 95% CI, 0.617-0.802) performed better than each individual biomarker (AUC PCT, 0.534; 95% CI, 0.433-0.636; AUC PSP, 0.665; 95% CI, 0.572-0.758) or severity score (AUC APACHE II, 0.638; 95% CI, 0.543-0.733; AUC SAPS II, 0.598; 95% CI, 0.499-0.698). These models were externally confirmed in the independent validation cohort. CONCLUSIONS We confirmed the prognostic value of PSP in patients with severe sepsis and septic shock requiring ICU management. A model combining severity scores with PCT and PSP improves mortality prediction in these patients.
Collapse
Affiliation(s)
- Yok-Ai Que
- Department of Adult Intensive Care Medicine, University Hospital Medical Center and University of Lausanne, Lausanne, Switzerland
| | - Idris Guessous
- Community Prevention Unit, University Hospital Medical Center and University of Lausanne, Lausanne, Switzerland; Unit of Population Epidemiology, Division of Primary Care Medicine, Department of Community Medicine, Primary Care and Emergency Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Elise Dupuis-Lozeron
- Unit of Population Epidemiology, Division of Primary Care Medicine, Department of Community Medicine, Primary Care and Emergency Medicine, Geneva University Hospitals, Geneva, Switzerland; Research Center for Statistics, University of Geneva, Geneva, Switzerland
| | - Clara Rodrigues Alves de Oliveira
- Institute of Social and Preventive Medicine, Infectious Diseases Service, University Hospital Medical Center and University of Lausanne, Lausanne, Switzerland
| | - Carolina Ferreira Oliveira
- Institute of Social and Preventive Medicine, Infectious Diseases Service, University Hospital Medical Center and University of Lausanne, Lausanne, Switzerland
| | - Rolf Graf
- Swiss Hepato-Pancreatico-Biliary Center, Department of Visceral and Transplant Surgery, University Hospital, Zürich, Switzerland
| | - Gérald Seematter
- Service d'Anesthésiologie, Hôpital Riviera, Montreux, Switzerland
| | - Jean-Pierre Revelly
- Department of Adult Intensive Care Medicine, University Hospital Medical Center and University of Lausanne, Lausanne, Switzerland
| | - Jean-Luc Pagani
- Department of Adult Intensive Care Medicine, University Hospital Medical Center and University of Lausanne, Lausanne, Switzerland
| | - Lucas Liaudet
- Department of Adult Intensive Care Medicine, University Hospital Medical Center and University of Lausanne, Lausanne, Switzerland
| | - Vandack Nobre
- Graduate Program in Infectious Diseases and Tropical Medicine, Department of Internal Medicine, School of Medicine, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Philippe Eggimann
- Department of Adult Intensive Care Medicine, University Hospital Medical Center and University of Lausanne, Lausanne, Switzerland.
| |
Collapse
|
25
|
Platelets in the immune response: Revisiting platelet-activating factor in anaphylaxis. J Allergy Clin Immunol 2015; 135:1424-32. [PMID: 26051949 DOI: 10.1016/j.jaci.2015.04.019] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Revised: 04/21/2015] [Accepted: 04/21/2015] [Indexed: 01/09/2023]
Abstract
Anaphylaxis is an acute, severe, life-threatening multisystem allergic reaction resulting from the sudden systemic release of biochemical mediators and chemotactic substances. Release of both preformed granule-associated mediators and newly generated lipid-derived mediators contributes to the amplification and prolongation of anaphylaxis. Platelet-activating factor (PAF) is a potent phospholipid-derived mediator the central role of which has been well established in experimental models of both immune-mediated and non-immune mediated anaphylaxis. It is produced and secreted by several types of cells, including mast cells, monocytes, tissue macrophages, platelets, eosinophils, endothelial cells, and neutrophils. PAF is implicated in platelet aggregation and activation through release of vasoactive amines in the inflammatory response, resulting in increased vascular permeability, circulatory collapse, decreased cardiac output, and various other biological effects. PAF is rapidly hydrolyzed and degraded to an inactive metabolite, lysoPAF, by the enzyme PAF acetylhydrolase, the activity of which has shown to correlate inversely with PAF levels and predispose to severe anaphylaxis. In addition to its role in anaphylaxis, PAF has also been implicated as a mediator in both allergic and nonallergic inflammatory diseases, including allergic rhinitis, sepsis, atherosclerotic disease, and malignancy, in which PAF signaling has an established role. The therapeutic role of PAF antagonism has been investigated for several diseases, with variable results thus far. Further investigation of its role in pathology and therapeutic modulation is highly anticipated because of the pressing need for more selective and targeted therapy for the management of severe anaphylaxis.
Collapse
|
26
|
Erlandson KM, Campbell TB. Inflammation in Chronic HIV Infection: What Can We Do? J Infect Dis 2015; 212:339-42. [DOI: 10.1093/infdis/jiv007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 01/05/2015] [Indexed: 12/19/2022] Open
|
27
|
Abstract
Sepsis, a common and potentially fatal systemic illness, is triggered by microbial infection and often leads to impaired function of the lungs, kidneys or other vital organs. Since the early 1980s, a large number of therapeutic agents for the treatment of sepsis have been evaluated in randomized controlled clinical trials. With few exceptions, the results from these trials have been disappointing, and no specific therapeutic agent is currently approved for the treatment of sepsis. To improve upon this dismal record, investigators will need to identify more suitable therapeutic targets, improve their approaches for selecting candidate compounds for clinical development and adopt better designs for clinical trials.
Collapse
Affiliation(s)
- Mitchell P Fink
- Departments of Surgery and Anesthesiology, David Geffen School of Medicine at University of California, Los Angeles, 10833 Le Conte Avenue, 72-160 CHS, Los Angeles California 90095, USA
| | - H Shaw Warren
- Infectious Disease Units, Departments of Pediatrics and Medicine, Massachusetts General Hospital East, 149 13th Street, Fifth Floor, Charlestown, Massachusetts 02129, USA
| |
Collapse
|
28
|
Marathe GK, Pandit C, Lakshmikanth CL, Chaithra VH, Jacob SP, D'Souza CJM. To hydrolyze or not to hydrolyze: the dilemma of platelet-activating factor acetylhydrolase. J Lipid Res 2014; 55:1847-54. [PMID: 24859738 DOI: 10.1194/jlr.r045492] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mounting ambiguity persists around the functional role of the plasma form of platelet-activating factor acetylhydrolase (PAF-AH). Because PAF-AH hydrolyzes PAF and related oxidized phospholipids, it is widely accepted as an anti-inflammatory enzyme. On the other hand, its actions can also generate lysophosphatidylcholine (lysoPC), a component of bioactive atherogenic oxidized LDL, thus allowing the enzyme to have proinflammatory capabilities. Presence of a canonical lysoPC receptor has been seriously questioned for a multitude of reasons. Animal models of inflammation show that elevating PAF-AH levels is beneficial and not deleterious and overexpression of PAF receptor (PAF-R) also augments inflammatory responses. Further, many Asian populations have a catalytically inert PAF-AH that appears to be a severity factor in a range of inflammatory disorders. Correlation found with elevated levels of PAF-AH and CVDs has led to the design of a specific PAF-AH inhibitor, darapladib. However, in a recently concluded phase III STABILITY clinical trial, use of darapladib did not yield promising results. Presence of structurally related multiple ligands for PAF-R with varied potency, existence of multi-molecular forms of PAF-AH, broad substrate specificity of the enzyme and continuous PAF production by the so called bi-cycle of PAF makes PAF more enigmatic. This review seeks to address the above concerns.
Collapse
Affiliation(s)
- Gopal Kedihitlu Marathe
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570006, India
| | - Chaitanya Pandit
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570006, India
| | | | | | - Shancy Petsel Jacob
- Department of Studies in Biochemistry, University of Mysore, Manasagangothri, Mysore 570006, India
| | | |
Collapse
|
29
|
Jiří Ž, Kýr M, Vavřina M, Fedora M. Pancreatic stone protein – A possible biomarker of multiorgan failure and mortality in children sepsis. Cytokine 2014; 66:106-11. [DOI: 10.1016/j.cyto.2014.01.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 11/12/2013] [Accepted: 01/20/2014] [Indexed: 11/28/2022]
|
30
|
Hoogeveen RC, Ballantyne CM. PLAC™ test for identification of individuals at increased risk for coronary heart disease. Expert Rev Mol Diagn 2014; 5:9-14. [PMID: 15723587 DOI: 10.1586/14737159.5.1.9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent advances in cardiovascular research point to a critical role of inflammatory processes in the etiology of cardiovascular disease. This has led to the discovery of novel inflammatory biomarkers, which may be useful as additional screening tools for the identification of individuals at increased risk of coronary heart disease. One such novel inflammatory biomarker is lipoprotein-associated phospholipase A(2). This review discusses the recent development of a US Food and Drug Administration-approved blood test for lipoprotein-associated phospholipase A(2) (PLAC test, diaDexus, Inc.) and its efficacy as a predictive biomarker of risk for cardiovascular disease. More specifically, the article addresses the potential target group most likely to benefit from this new screening test and provides a prospective scenario for its implementation.
Collapse
Affiliation(s)
- Ron C Hoogeveen
- Baylor College of Medicine, Section of Atherosclerosis & Lipoprotein Research, Department of Medicine, Center for Cardiovascular Disease Prevention, Houston, TX 77030, USA.
| | | |
Collapse
|
31
|
Chakraborti S, Alam MN, Chaudhury A, Sarkar J, Pramanik A, Asrafuzzaman S, Das SK, Ghosh SN, Chakraborti T. Pathophysiological Aspects of Lipoprotein-Associated Phospholipase A2: A Brief Overview. PHOSPHOLIPASES IN HEALTH AND DISEASE 2014:115-133. [DOI: 10.1007/978-1-4939-0464-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
|
32
|
Teixeira-da-Cunha MGA, Gomes RN, Roehrs N, Bozza FA, Prescott SM, Stafforini D, Zimmerman GA, Bozza PT, Castro-Faria-Neto HC. Bacterial clearance is improved in septic mice by platelet-activating factor-acetylhydrolase (PAF-AH) administration. PLoS One 2013; 8:e74567. [PMID: 24069320 PMCID: PMC3771912 DOI: 10.1371/journal.pone.0074567] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 08/05/2013] [Indexed: 11/18/2022] Open
Abstract
Current evidence indicates that dysregulation of the host inflammatory response to infectious agents is central to the mortality of patients with sepsis. Strategies to block inflammatory mediators such as PAF have been investigated as adjuvant therapies for sepsis. PAF-AH, the enzyme responsible for PAF degradation, showed positive results in pre-clinical studies and phase II clinical trials, but the results of a phase III study were disappointing. In this study, we investigated the potential protective mechanism of PAF-AH in sepsis using the murine model of cecal ligation and puncture (CLP). Treatment with rPAF-AH increased peritoneal fluid levels of the anti-inflammatory mediators MCP-1/CCL2 after CLP. The numbers of bacteria (CFU) in the peritoneal cavity were decreased in the rPAF-AH-treated group, indicating more efficient bacterial clearance after rPAF-AH treatment. Interestingly, we observed increased levels of nitric oxide (NO) after PAF-AH administration, and rPAF-AH treatment did not decrease CFU numbers either in iNOS-deficient mice or in CCR2-deficient mice. We concluded that administration of exogenous rPAF-AH reduced inflammatory injury, altered cytokine levels and favored bacterial clearance with a clear impact on mortality through modulation of MCP-1/CCL2 and NO levels in a clinically relevant sepsis model.
Collapse
Affiliation(s)
| | - Rachel N. Gomes
- Laboratório De Imunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, RJ, Brazil
- Laboratório de Investigação em Medicina Intensiva, IPEC, Fiocruz, RJ, Brazil
- * E-mail:
| | - Nathassia Roehrs
- Laboratório De Imunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, RJ, Brazil
| | - Fernando A. Bozza
- Laboratório de Investigação em Medicina Intensiva, IPEC, Fiocruz, RJ, Brazil
| | - Stephen M. Prescott
- Oklahoma Medical Research Foundation, Oklahoma City, United States of America
| | - Diana Stafforini
- Huntsman Cancer Institute, Salt Lake City, Utah, United States of America
| | - Guy A. Zimmerman
- Program in Human Molecular Biology and Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Patricia T. Bozza
- Laboratório De Imunofarmacologia, Instituto Oswaldo Cruz, Fiocruz, RJ, Brazil
| | | |
Collapse
|
33
|
Abstract
Sepsis remains a common, serious, and heterogeneous clinical entity that is difficult to define adequately. Despite its importance as a public health problem, efforts to develop and gain regulatory approval for a specific therapeutic agent for the adjuvant treatment of sepsis have been remarkably unsuccessful. One step in the critical pathway for the development of a new agent for adjuvant treatment of sepsis is evaluation in an appropriate animal model of the human condition. Unfortunately, the animal models that have been used for this purpose have often yielded misleading findings. It is likely that there are multiple reasons for the discrepancies between the results obtained in tests of pharmacological agents in animal models of sepsis and the outcomes of human clinical trials. One of important reason may be that the changes in gene expression, which are triggered by trauma or infection, are different in mice, a commonly used species for preclinical testing, and humans. Additionally, many species, including mice and baboons, are remarkably resistant to the toxic effects of bacterial lipopolysaccharide, whereas humans are exquisitely sensitive. New approaches toward the use of animals for sepsis research are being investigated. But, at present, results from preclinical studies of new therapeutic agents for sepsis must be viewed with a degree of skepticism.
Collapse
Affiliation(s)
- Mitchell P Fink
- Departments of Surgery and Anesthesiology; David Geffen School of Medicine at UCLA; Los Angeles, CA USA
| |
Collapse
|
34
|
Vincent JL, Van Nuffelen M. Septic shock: new pharmacotherapy options or better trial design? Expert Opin Pharmacother 2013; 14:561-70. [DOI: 10.1517/14656566.2013.777429] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
35
|
D'Elia RV, Harrison K, Oyston PC, Lukaszewski RA, Clark GC. Targeting the "cytokine storm" for therapeutic benefit. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:319-27. [PMID: 23283640 PMCID: PMC3592351 DOI: 10.1128/cvi.00636-12] [Citation(s) in RCA: 239] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Inflammation is the body's first line of defense against infection or injury, responding to challenges by activating innate and adaptive responses. Microbes have evolved a diverse range of strategies to avoid triggering inflammatory responses. However, some pathogens, such as the influenza virus and the Gram-negative bacterium Francisella tularensis, do trigger life-threatening "cytokine storms" in the host which can result in significant pathology and ultimately death. For these diseases, it has been proposed that downregulating inflammatory immune responses may improve outcome. We review some of the current candidates for treatment of cytokine storms which may prove useful in the clinic in the future and compare them to more traditional therapeutic candidates that target the pathogen rather than the host response.
Collapse
|
36
|
Zhang H, Zhang J, Shen D, Zhang L, He F, Dang Y, Li L. Lentiviral-mediated RNA interference of lipoprotein-associated phospholipase A2 ameliorates inflammation and atherosclerosis in apolipoprotein E-deficient mice. Int J Mol Med 2013; 31:651-9. [PMID: 23338278 DOI: 10.3892/ijmm.2013.1248] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 12/04/2012] [Indexed: 11/05/2022] Open
Abstract
Lipoprotein associated phospholipase A2 (Lp-PLA2) overexpression is implicated in athero-sclerosis. In the present study, we evaluated the effects of lentiviral-mediated RNA interference (RNAi) of Lp-PLA2 on inflammation and atherosclerosis in apolipoprotein E-deficient mice. Apolipoprotein E-deficient mice were randomly allocated to control and experimental groups, and constrictive collars were used to induce plaque formation. Eight weeks after surgery, the lentiviral-mediated RNAi construct was used to silence expression of Lp-PLA2. Control and experimental lentivirus was transfected directly into carotid plaques or administered systemically. Tissues were collected for analysis 7 weeks after transfection. Inflammatory gene expression in the plasma and atherosclerotic lesions was then determined at the mRNA and protein levels. We observed no differences in body weight and plasma lipid levels at the end of the investigation. However, the expression levels of Lp-PLA2 and pro-inflammatory cytokines were significantly reduced in the RNAi groups, compared to the controls, whereas the plasma concentration of anti-inflammatory cytokines was markedly increased. Moreover, our results demonstrated a significant reduction in plaque area and lipid content, as well as a rise in collagen content following RNAi treatment. Importantly, when comparing the two methods of viral delivery, we found that transluminal local transfection exhibited enhanced improvement of plaque stability as compared to systemic administration. Inhibition of Lp-PLA2 by lentiviral-mediated RNAi ameliorates inflammation and atherosclerosis in apolipoprotein E-deficient mice. In addition, transluminal local delivery of Lp-PLA2 shRNA is superior to systemic administration for stabilizing atherosclerotic plaques.
Collapse
Affiliation(s)
- Hui Zhang
- Department of Cardiology, The First Affliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, PR China
| | | | | | | | | | | | | |
Collapse
|
37
|
Jiang Z, Fehrenbach ML, Ravaioli G, Kokalari B, Redai IG, Sheardown SA, Wilson S, Macphee C, Haczku A. The effect of lipoprotein-associated phospholipase A2 deficiency on pulmonary allergic responses in Aspergillus fumigatus sensitized mice. Respir Res 2012; 13:100. [PMID: 23140447 PMCID: PMC3546878 DOI: 10.1186/1465-9921-13-100] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 11/06/2012] [Indexed: 12/05/2022] Open
Abstract
Background Lipoprotein-associated phospholipase A2 (Lp-PLA2)/platelet-activating factor acetylhydrolase (PAF-AH) has been implicated in the pathogenesis of cardiovascular disease. A therapeutic targeting of this enzyme was challenged by the concern that increased circulating platelet activating factor (PAF) may predispose to or increase the severity of the allergic airway response. The aim of this study was to investigate whether Lp-PLA2 gene deficiency increases the risk of PAF and IgE-mediated inflammatory responses in vitro and in vivo using mouse models. Methods Lp-PLA2-/- mice were generated and back crossed to the C57BL/6 background. PAF-AH activity was measured using a hydrolysis assay in serum and bronchoalveolar lavage (BAL) samples obtained from mice. Aspergillus fumigatus (Af)-specific serum was prepared for passive allergic sensitization of mice in vivo and mast cells in vitro. β- hexosaminidase release was studied in bone marrow derived mast cells sensitized with Af-specific serum or DNP-IgE and challenged with Af or DNP, respectively. Mice were treated with lipopolysaccharide (LPS) and PAF intratracheally and studied 24 hours later. Mice were sensitized either passively or actively against Af and were studied 48 hours after a single intranasal Af challenge. Airway responsiveness to methacholine, inflammatory cell influx in the lung tissue and BAL, immunoglobulin (ELISA) and cytokine (Luminex) profiles were compared between the wild type (WT) and Lp-PLA2-/- mice. Results PAF-AH activity was reduced but not completely abolished in Lp-PLA2-/- serum or by in vitro treatment of serum samples with a high saturating concentration of the selective Lp-PLA2 inhibitor, SB-435495. PAF inhalation significantly enhanced airway inflammation of LPS treated WT and Lp-PLA2-/- mice to a similar extent. Sensitized WT and Lp-PLA2-/- bone-marrow derived mast cells released β-hexosaminidase following stimulation by allergen or IgE crosslinking to equivalent levels. Wild type and Lp-PLA2-/- mice responded to passive or active allergic sensitization by significant IgE production, airway inflammation and hyperresponsiveness after Af challenge. BAL cell influx was not different between these strains while IL-4, IL-5, IL-6 and eotaxin release was attenuated in Lp-PLA2-/- mice. There were no differences in the amount of total IgE levels in the Af sensitized WT and Lp-PLA2-/- mice. Conclusions We conclude that Lp-PLA2 deficiency in C57BL/6 mice did not result in a heightened airway inflammation or hyperresponsiveness after PAF/LPS treatment or passive or active allergic sensitization and challenge.
Collapse
Affiliation(s)
- Zhilong Jiang
- Pulmonary, Allergy and Critical Care Division, University of Pennsylvania, Philadelphia, PA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Antisense inhibition of phospholipase A2: a new approach for already tested therapeutic targets for the treatment of sepsis*. Crit Care Med 2012; 40:2250-1. [PMID: 22710222 DOI: 10.1097/ccm.0b013e31825151bd] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
39
|
Liu MS, Liu CH, Wu G, Zhou Y. Antisense inhibition of secretory and cytosolic phospholipase A2 reduces the mortality in rats with sepsis*. Crit Care Med 2012; 40:2132-40. [PMID: 22564957 DOI: 10.1097/ccm.0b013e31824e1e20] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Phospholipase A(2) has been implicated to play a pivotal role in the pathogenesis of sepsis syndrome. The two major forms of phospholipase A(2) isoenzymes, secretory phospholipase A(2) and cytosolic phospholipase A(2), are overexpressed during sepsis. The objective of this study was to test the hypothesis that inhibition of the overexpressed secretory phospholipase A(2) and cytosolic phospholipase A(2) during sepsis benefits the disease's eventual outcome. DESIGN Short-chain antisense oligonucleotide molecules were designed with the aid of computer software programs, and their in vitro efficacies were assessed in cell culture systems based on inhibition of target protein expression. The in vivo efficacies were determined in intact sepsis rats using 35-day survival rate as a primary efficacy end point. SETTING Animal research laboratory at a university. SUBJECTS Male Sprague-Dawley rats (180-200 g). INTERVENTIONS Sepsis was induced by cecal ligation and puncture. Antibiotics were administered subcutaneously once daily at 12 mg/kg, for 20 days. Oligonucleotides (antisense or mismatch) were administered intravenously once daily at 2 mg/kg to 0.8 mg/kg in a decreasing order, for 20 days. MEASUREMENTS AND MAIN RESULTS In cell culture systems, 21 of the 105 antisense constructs were found to be efficacious in inhibiting secretory phospholipase A(2) IIa and cytosolic phospholipase A(2) IVa protein expression. In sepsis rats, antisense oligonucleotides were capable of reducing their target protein expression by 18%-61% in major organs such as liver, heart, and kidney. In animal experiments, sepsis without any treatment (Group 1) had a median survival time of 2 days and a zero (0) percent survival rate at day 14. Sepsis with antibiotic treatment (Group 2) had a median survival time of 6 days and a 35-day survival rate of 28%. Sepsis with cotreatment of antibiotics and antisense oligonucleotides (one against secretory phospholipase A2 IIa and the other against cytosolic phospholipase A(2) IVa) (Group 4) increased the median survival time from 6 to 35 days and the 35-day survival rate from 28% to 58.8% as compared with antibiotics alone (Group 4 vs. Group 2; p <.05). Sepsis with cotreatment of antibiotics and mismatch oligonucleotides (Group 3) did not affect the median survival time and the 35-day survival rate as compared to antibiotics alone (Group 3 vs. Group 2; p >.05). CONCLUSIONS The results demonstrate that antisense strategy against secretory phospholipase A(2) IIa and cytosolic phospholipase A(2) IVa can inhibit their target protein expression in major organs and greatly improve the clinical outcome, i.e., an absolute reduction in 35-day mortality of 30.8%, in rats with sepsis. Our studies, thus, provide an improved method for the treatment of sepsis by targeting multiple forms of phospholipase A(2) isoenzymes with DNA antisense oligomers.
Collapse
Affiliation(s)
- Maw-Shung Liu
- Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, St Louis, MO, USA.
| | | | | | | |
Collapse
|
40
|
Toft P, Tønnesen E. Immune-modulating interventions in critically ill septic patients: pharmacological options. Expert Rev Clin Pharmacol 2012; 4:491-501. [PMID: 22114858 DOI: 10.1586/ecp.11.25] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Critically ill patients with severe sepsis and septic shock are characterized by a systemic inflammatory response consisting of pro- and anti-inflammatory mediators. Owing to the high mortality of severe sepsis, great efforts have been undertaken within the last 30 years to develop an immune-modulating therapy to improve survival. Relatively few pharmacological immune-modulating interventions have demonstrated a beneficial impact on survival, while other studies have shown a detrimental effect of such interventions. Among the immune-modulating interventions tested, activated protein C and intensive insulin therapy have been shown to improve survival in septic patients. However, in later studies, it has been difficult to reproduce these beneficial effects. There appears to be a discrepancy between the promising effects of immune-modulating interventions in animal studies and the effects seen in the clinical setting. In the future, the onset of the proinflammatory versus the anti-inflammatory response must be better defined and the timing of treatment with immune-modulating agents should be better managed.
Collapse
Affiliation(s)
- Palle Toft
- Odense University Hospital, DK-5000 Odense C, Denmark
| | | |
Collapse
|
41
|
Abstract
Although an atherogenic lipoprotein phenotype has been well recognized as an important predictor of cardiovascular disease, recent studies have demonstrated a number of additional lipid-related markers as emerging biomarkers to identify patients at risk for future coronary heart disease. Among them, lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), seems to be a promising candidate that might be added to the clinical armamentarium for improved prediction of cardiovascular disease in the future. Of particular note, Lp-PLA(2) is the only enzyme that cleaves oxidized low-density lipoprotein (oxLDL) in the subendothelial space, with further generation of proinflammatory mediators such as lysophosphatidylcholine (LysoPC) and oxidized fatty acid (oxFA), thereby probably linking two important features of atherogenesis, namely oxidation of LDL and local inflammatory processes within the atherosclerotic plaque. This overview aims to summarize our current knowledge based on observations from recent experimental and clinical studies. Emphasis has been put on potential pathophysiological mechanisms of action and on the clinical relevance of Lp-PLA(2) in a wide variety of clinical settings, including apparently healthy individuals, patients with stable angina or acute coronary syndromes, after myocardial infarction, and with subclinical disease. Although a growing body of evidence from epidemiological and clinical studies suggests that Lp-PLA(2) may represent an independent and clinically relevant long-term risk marker for coronary heart disease and, probably, also for stroke, the role of this enzyme in the setting of the acute coronary syndrome remains to be established.
Collapse
Affiliation(s)
- Natalie Khuseyinova
- Department of Internal Medicine II - Cardiology, University of Ulm Medical Center, Ulm, Germany
| | | |
Collapse
|
42
|
Que YA, Delodder F, Guessous I, Graf R, Bain M, Calandra T, Liaudet L, Eggimann P. Pancreatic stone protein as an early biomarker predicting mortality in a prospective cohort of patients with sepsis requiring ICU management. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2012; 16:R114. [PMID: 22748193 PMCID: PMC3580689 DOI: 10.1186/cc11406] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Accepted: 07/02/2012] [Indexed: 12/16/2022]
Abstract
Introduction Biomarkers, such as C-reactive protein [CRP] and procalcitonin [PCT], are insufficiently sensitive or specific to stratify patients with sepsis. We investigate the prognostic value of pancreatic stone protein/regenerating protein (PSP/reg) concentration in patients with severe infections. Methods PSP/reg, CRP, PCT, tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL1-β), IL-6 and IL-8 were prospectively measured in cohort of patients ≥ 18 years of age with severe sepsis or septic shock within 24 hours of admission in a medico-surgical intensive care unit (ICU) of a community and referral university hospital, and the ability to predict in-hospital mortality was determined. Results We evaluated 107 patients, 33 with severe sepsis and 74 with septic shock, with in-hospital mortality rates of 6% (2/33) and 25% (17/74), respectively. Plasma concentrations of PSP/reg (343.5 vs. 73.5 ng/ml, P < 0.001), PCT (39.3 vs. 12.0 ng/ml, P < 0.001), IL-8 (682 vs. 184 ng/ml, P < 0.001) and IL-6 (1955 vs. 544 pg/ml, P < 0.01) were significantly higher in patients with septic shock than with severe sepsis. Of note, median PSP/reg was 13.0 ng/ml (IQR: 4.8) in 20 severely burned patients without infection. The area under the ROC curve for PSP/reg (0.65 [95% CI: 0.51 to 0.80]) was higher than for CRP (0.44 [0.29 to 0.60]), PCT 0.46 [0.29 to 0.61]), IL-8 (0.61 [0.43 to 0.77]) or IL-6 (0.59 [0.44 to 0.75]) in predicting in-hospital mortality. In patients with septic shock, PSP/reg was the only biomarker associated with in-hospital mortality (P = 0.049). Risk of mortality increased continuously for each ascending quartile of PSP/reg. Conclusions Measurement of PSP/reg concentration within 24 hours of ICU admission may predict in-hospital mortality in patients with septic shock, identifying patients who may benefit most from tailored ICU management.
Collapse
|
43
|
The systemic mediator-associated response test identifies patients in failed sepsis clinical trials among whom novel drugs reduce mortality. ACTA ACUST UNITED AC 2011; 71:1406-14. [PMID: 21537209 DOI: 10.1097/ta.0b013e3182159c61] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Clinical trials using American College of Chest Physicians/Society of Critical Care Medicine Consensus sepsis definitions as entry criteria fail to reduce septic mortality. We hypothesized that the systemic mediator-associated response test (SMART) methodology could match sepsis therapies biologically to individual patients by relating baseline data statistically to outcomes and treatment effects. This article reports the SMART analyses of four failed sepsis investigations. METHODS Databases from the E5 antiendotoxin antibody, North American Sepsis Trial (NORASEPT) and NORASEPT II anti-tumor necrosis factor antibody (TNFMAb), interleukin (IL)-1ra, and platelet-activation factor acetylhydrolase (PAF-AH) sepsis clinical trials were evaluated with SMART using multivariate logistic regression. From baseline data, within each study, mortality prediction models were built separately for the placebo and active drug populations. Subjects among whom each drug's effects were greatest were then identified by excluding from efficacy analysis subjects predicted by SMART to survive on placebo or to expire on active drug. Finally, prerandomization data from patients in each study were entered into SMART models, and placebo or active drug treatment effects were evaluated for parent populations and SMART cohorts. RESULTS E5-consensus mortality: 27.4% placebo, 26.2% E5; SMART mortality: 17.1% placebo, 8.0% E5 (p < 0.01). NORASEPT-consensus mortality; 33.4% placebo, 29.5% TNFMAb; SMART mortality: 47.2% placebo, 34.7% TNFMAb (p = 0.03). IL-1ra-consensus mortality: 33.9% placebo, 29.8% IL-1ra; SMART mortality: 55.6% placebo, 34.9% IL-1ra (p < 0.001). PAF-AH-consensus mortality: 22.4% placebo, 23.9% PAF-AH; SMART mortality: 17.7% placebo, 28.9% PAF-AH (p = 0.039). CONCLUSIONS Using prerandomization clinical trial data, SMART identifies septic patients whose host-inflammatory responses can benefit from specific drugs. SMART also predicts ineffective drugs and patients whom they might harm.
Collapse
|
44
|
Hu MM, Zhang J, Wang WY, Wu WY, Ma YL, Chen WH, Wang YP. The inhibition of lipoprotein-associated phospholipase A2 exerts beneficial effects against atherosclerosis in LDLR-deficient mice. Acta Pharmacol Sin 2011; 32:1253-8. [PMID: 21970837 DOI: 10.1038/aps.2011.127] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIM To investigate the effects of darapladib, a specific inhibitor of lipoprotein-associated phospholipase A2 (lp-PLA2), on inflammation and atherosclerotic formation in the low density lipoprotein receptor (LDLR)-deficient mice. METHODS Six-week-old LDLR-deficient mice were fed an atherogenic high-fat diet for 17 weeks and then randomly divided into two groups. One group was administered darapladib (50 mg·kg(-1)·d(-1); po) for 6 weeks. The other group was administered saline as a control. Serum lipid levels were measured using the corresponding kits, and three inflammatory markers--interleukin-6 (IL-6), C reactive protein (hs-CRP), and platelet activating factor (PAF)--were determined using ELISA. Atherosclerotic plaque areas were stained with Sudan IV, and inflammatory gene expression at the lesions was evaluated using quantitative real-time PCR. RESULTS The body weight and serum lipid level between the two groups were similar at the end of the dietary period. The serum lp-PLA2 activity, hs-CRP and IL-6 levels, however, were significantly reduced in the darpladib group. The inhibition of lp-PLA2 did not alter the serum PAF level. Furthermore, the plaque area, from the aortic arch to the abdominal aorta, was significantly reduced in the darpladib group. Additionally, the expression of inflammatory genes monocyte chemotactic protein-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) was significantly reduced at the lesions in the darapladib group. CONCLUSION Inhibition of lp-PLA2 by darapladib decreases the inflammatory burden and atherosclerotic plaque formation in LDLR-deficient mice, which may be a new strategy for the treatment of atherosclerosis.
Collapse
|
45
|
Navarro-Fernández J, Nechitaylo TY, Guerrero JA, Golyshina OV, García-Carmona F, Sánchez-Ferrer A, Golyshin PN. A novel platelet-activating factor acetylhydrolase discovered in a metagenome from the earthworm-associated microbial community. Environ Microbiol 2011; 13:3036-46. [PMID: 21923856 DOI: 10.1111/j.1462-2920.2011.02581.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Metagenomics is an emerging field for mining the bioresources for new biomolecules for potential application in biotechnology and biomedicine. In the present study, a novel acetylhydrolase (Est13) was detected during the function-based screening of a metagenomic library established from the DNA extracted from the cellulose-depleting microbial community set up with an earthworm cast. Analysis showed that Est13 exhibited some similarities with a human and parasite platelet-activating factor acetylhydrolase (PAF-AH) belonging to the SGNH hydrolase superfamily. Biochemical characterization of the purified recombinant enzyme using substrates common for hydrolases of this superfamily demonstrated that Est13 hydrolysed p-nitrophenyl acetate quite efficiently, with a k(cat) /K(M) value of 3209 mM(-1) s(-1). The Est13 showed highest activity at pH 8.0 and 40°C, conditions in which it is relatively stable compared with known PAF-AHs. In vitro functional analysis of the platelet-activating factor hydrolysis showed a dose- and time-dependent inhibition of platelet aggregation in the range of 2-4 µM, making this enzyme a potential candidate for biomedical applications.
Collapse
Affiliation(s)
- José Navarro-Fernández
- Department of Biochemistry and Molecular Biology-A, Faculty of Biology, University of Murcia, Campus Espinardo, E-30100 Murcia, Spain
| | | | | | | | | | | | | |
Collapse
|
46
|
Wang WY, Zhang J, Wu WY, Li J, Ma YL, Chen WH, Yan H, Wang K, Xu WW, Shen JH, Wang YP. Inhibition of lipoprotein-associated phospholipase A2 ameliorates inflammation and decreases atherosclerotic plaque formation in ApoE-deficient mice. PLoS One 2011; 6:e23425. [PMID: 21909350 PMCID: PMC3166130 DOI: 10.1371/journal.pone.0023425] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 07/16/2011] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Lipoprotein-associated phospholipase A2 (Lp-PLA2) is thought to play modulatory roles in the development of atherosclerosis. Here we evaluated the effects of a specific lp-PLA2 inhibitor on atherosclerosis in ApoE-deficient mice and its associated mechanisms. METHODOLOGY/PRINCIPAL FINDINGS ApoE-deficient mice fed an atherogenic high-fat diet for 17 weeks were divided into two groups. One group was administered the specific lp-PLA2 inhibitor, darapladib (50 mg/kg/day; p.o.) daily for 6 weeks, while the control group was administered saline. We observed no differences in body weight and serum lipids levels between the two groups at the end of the dietary period. Notably, serum lp-PLA2 activity as well as hs-CRP (C-reactive protein) and IL-6 (Interleukin-6) levels were significantly reduced in the darapladib group, compared with the vehicle group, while the serum PAF (platelet-activating factor) levels were similar between the two groups. Furthermore, the plaque area through the arch to the abdominal aorta was reduced in the darapladib group. Another finding of interest was that the macrophage content was decreased while collagen content was increased in atherosclerotic lesions at the aortic sinus in the darapladib group, compared with the vehicle group. Finally, quantitative RT-PCR performed to determine the expression patterns of specific inflammatory genes at atherosclerotic aortas revealed lower expression of MCP-1, VCAM-1 and TNF-α in the darapladib group. CONCLUSIONS/SIGNIFICANCE Inhibition of lp-PLA2 by darapladib leads to attenuation of in vivo inflammation and decreased plaque formation in ApoE-deficient mice, supporting an anti-atherogenic role during the progression of atherosclerosis.
Collapse
Affiliation(s)
- Wen-yi Wang
- Department of Pharmacology I, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Jie Zhang
- Department of Pharmacology I, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Wen-yu Wu
- Department of Pharmacology I, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Jie Li
- Department of Pharmacology I, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yan-ling Ma
- Department of Pharmacology I, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Wei-hai Chen
- Key Laboratory of Cognition and Personality (SWU), Ministry of Education, Southwest University, Chongqing, China
- School of Psychology, Southwest University, Chongqing, China
| | - Hong Yan
- Department of Pharmacology I, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Kai Wang
- School of Psychology, Southwest University, Chongqing, China
| | - Wen-wei Xu
- Department of Pharmacology I, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Jian-hua Shen
- Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Yi-ping Wang
- Department of Pharmacology I, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
- * E-mail:
| |
Collapse
|
47
|
Liu J, Chen R, Marathe GK, Febbraio M, Zou W, McIntyre TM. Circulating platelet-activating factor is primarily cleared by transport, not intravascular hydrolysis by lipoprotein-associated phospholipase A2/ PAF acetylhydrolase. Circ Res 2011; 108:469-77. [PMID: 21183738 PMCID: PMC3057131 DOI: 10.1161/circresaha.110.228742] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 12/15/2010] [Indexed: 01/23/2023]
Abstract
RATIONALE The phospholipid platelet-activating factor (PAF) stimulates all cells of the innate immune system and numerous cardiovascular cells. A single enzyme (plasma PAF acetylhydrolase [PAF-AH] or lipoprotein-associated phospholipase [Lp-PL]A(2)) in plasma hydrolyzes PAF, but significant controversy exists whether its action is pro- or antiinflammatory and accordingly whether its inhibition will slow cardiovascular disease. OBJECTIVE We sought to define how PAF and related short-chain oxidized phospholipids turnover in vivo and the role of PAF acetylhydrolase/Lp-PLA(2) in this process. METHODS AND RESULTS [(3)H-acetyl]PAF was hydrolyzed by murine or human plasma (t(1/2), 3 and 7 minutes, respectively), but injected [(3)H-acetyl]PAF disappeared from murine circulation more quickly (t(1/2), <30 seconds). [(3)H]PAF clearance was unchanged in PAF receptor(-/-) animals, or over the first 2 half-lives in PAF-AH(-/-) animals. [(3)H]PAF turnover was reduced by coinjecting excess unlabeled PAF or an oxidatively truncated phospholipid, and [(3)H]PAF clearance was slowed in hyperlipidemic apolipoprotein (apo)E(-/-) mice with excess circulating oxidatively truncated phospholipids. [(3)H]PAF, fluorescent NBD-PAF, or fluorescent oxidatively truncated phospholipid were primarily accumulated by liver and lung, and were transported into endothelium as intact phospholipids through a common mechanism involving TMEM30a. CONCLUSIONS Circulating PAF and oxidized phospholipids are continually and rapidly cleared, and hence continually and rapidly produced. Saturable PAF receptor-independent transport, rather than just intravascular hydrolysis, controls circulating inflammatory and proapoptotic oxidized phospholipid mediators. Intravascular PAF has access to intracellular compartments. Inflammatory and proapoptotic phospholipids may accumulate in the circulation as transport is overwhelmed by substrates in hyperlipidemia.
Collapse
Affiliation(s)
- Jinbo Liu
- Department of Cell Biology, NE10, Lerner Research Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, OH 44195, USA
| | | | | | | | | | | |
Collapse
|
48
|
Schmidt GA. Counterpoint: adherence to early goal-directed therapy: does it really matter? No. Both risks and benefits require further study. Chest 2010; 138:480-3; discussion 483-4. [PMID: 20822987 DOI: 10.1378/chest.10-1400] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- Gregory A Schmidt
- Division of Pulmonary Diseases, Critical Care, and Occupational Medicine, Department of Internal Medicine, University of Iowa, Iowa City, IA 52242, USA.
| |
Collapse
|
49
|
White H. Darapladib and its potential for plaque stabilization and prevention of cardiac events. ACTA ACUST UNITED AC 2010. [DOI: 10.2217/clp.10.45] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
50
|
Yost CC, Weyrich AS, Zimmerman GA. The platelet activating factor (PAF) signaling cascade in systemic inflammatory responses. Biochimie 2010; 92:692-7. [PMID: 20167241 PMCID: PMC2878918 DOI: 10.1016/j.biochi.2010.02.011] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Accepted: 02/11/2010] [Indexed: 12/21/2022]
Abstract
The platelet-activating factor (PAF) signaling cascade evolved as a component of the repertoire of innate host defenses, but is also an effector pathway in inflammatory and thrombotic diseases. This review focuses on the PAF signaling cascade in systemic inflammatory responses and, specifically, explores its activities in experimental and clinical sepsis and anaphylaxis in the context of the basic biochemistry and biology of signaling via this lipid mediator system.
Collapse
Affiliation(s)
- Christian C. Yost
- Department of Pediatrics, University of Utah, Salt Lake City, UT 84112
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84112
| | - Andrew S. Weyrich
- Department of Internal Medicine, University of Utah, Salt Lake City, UT 84112
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84112
| | - Guy A. Zimmerman
- Department of Internal Medicine, University of Utah, Salt Lake City, UT 84112
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84112
| |
Collapse
|