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Eliwan HO, Watson WRG, Melo AM, Kelly LA, Omer M, Jafar A, O'Hare FM, Downey P, Mooney EE, O'Neill A, Blanco A, Regan I, Philbin B, O'Rourke M, Nolan B, Smith O, Molloy EJ. Selective modulation of monocyte and neutrophil responses with activated protein C in preterm infants. J Matern Fetal Neonatal Med 2023; 36:2183467. [PMID: 36935364 DOI: 10.1080/14767058.2023.2183467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2023]
Abstract
BACKGROUND Inflammation is associated with many disorders of preterm infants including periventricular leukomalacia, chronic lung disease, and necrotizing enterocolitis. Activated protein c (APC) has shown positive immunomodulatory effects. OBJECTIVES We aimed to study neutrophil and monocyte function in response to lipopolysaccharide (LPS) and APC stimulation ex vivo in preterm infants <32 weeks gestation over the first week of life compared to neonatal and adult controls. METHODS Peripheral blood was taken on day 1, 3, and 7 and stimulated with LPS in the absence or presence of APC. Expression of toll-like receptor 4 (TLR4) and CD11b and reactive oxygen intermediate (ROI) release from neutrophils and monocytes was examined by flow cytometry. RESULTS LPS induced neutrophil ROI in adults and preterm infants and was significantly reduced by APC. Baseline and LPS-induced monocyte ROI production in preterm neonates was increased compared to adult and term controls. Neutrophil TLR4 baseline expression was higher in term controls compared to preterm infants. CONCLUSION Increased systemic ROI release in preterm infants may mediate tissue damage, ROI was reduced by APC. However, due to the high risk of hemorrhage further examination of APC mutant forms with anti-inflammatory but decreased anticoagulant properties is merited.
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Affiliation(s)
- Hassan O Eliwan
- UCD School of Medicine and Medical Science & Conway Institute for Biomolecular and Biomedical Science, University College, Dublin, Ireland
- National Children Research Centre, Dublin, Ireland
- Paediatrics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - William R G Watson
- UCD School of Medicine and Medical Science & Conway Institute for Biomolecular and Biomedical Science, University College, Dublin, Ireland
| | - Ashanty M Melo
- Paediatrics, Trinity College Dublin, Children's Health Ireland (CHI) at Tallaght, Dublin, Ireland
| | - Lynne A Kelly
- Paediatrics, Trinity College Dublin, Children's Health Ireland (CHI) at Tallaght, Dublin, Ireland
| | - Murwan Omer
- Paediatrics, Trinity College Dublin, Children's Health Ireland (CHI) at Tallaght, Dublin, Ireland
- Coombe Women and Infants' University Hospital, Dublin, Ireland
| | - Ali Jafar
- Paediatrics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Fiona M O'Hare
- UCD School of Medicine and Medical Science & Conway Institute for Biomolecular and Biomedical Science, University College, Dublin, Ireland
- National Children Research Centre, Dublin, Ireland
| | - Paul Downey
- Pathology, National Maternity Hospital, Dublin, Ireland
| | | | - Amanda O'Neill
- UCD School of Medicine and Medical Science & Conway Institute for Biomolecular and Biomedical Science, University College, Dublin, Ireland
| | - Alfonso Blanco
- UCD School of Medicine and Medical Science & Conway Institute for Biomolecular and Biomedical Science, University College, Dublin, Ireland
| | - Irene Regan
- Haematology, Children's Health Ireland (CHI) at Crumlin, Dublin, Ireland
| | - Brian Philbin
- Haematology, Children's Health Ireland (CHI) at Crumlin, Dublin, Ireland
| | - Michelle O'Rourke
- Haematology, Children's Health Ireland (CHI) at Crumlin, Dublin, Ireland
| | - Beatrice Nolan
- Haematology, Children's Health Ireland (CHI) at Crumlin, Dublin, Ireland
| | - Owen Smith
- Paediatrics, Trinity College Dublin, Children's Health Ireland (CHI) at Tallaght, Dublin, Ireland
- Haematology, Children's Health Ireland (CHI) at Crumlin, Dublin, Ireland
| | - Eleanor J Molloy
- UCD School of Medicine and Medical Science & Conway Institute for Biomolecular and Biomedical Science, University College, Dublin, Ireland
- National Children Research Centre, Dublin, Ireland
- Paediatrics, Trinity College Dublin, Children's Health Ireland (CHI) at Tallaght, Dublin, Ireland
- Coombe Women and Infants' University Hospital, Dublin, Ireland
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Hao W, Gu Y, Hu S, Ji X, Wang Y, Duan J. An Exploration of Anti-Inflammatory Therapy in Acute/Subacute Severe Cerebral Venous Thrombosis with Hereditary Protein C/S Deficiency: Case Series. J Inflamm Res 2023; 16:5403-5415. [PMID: 38026243 PMCID: PMC10676091 DOI: 10.2147/jir.s428589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 10/18/2023] [Indexed: 12/01/2023] Open
Abstract
Background Inflammation was associated with the severity of severe cerebral venous thrombosis (CVT) on admission and poor prognosis at discharge. Hereditary protein C/S deficiency (hereditary PCD/PSD) not only promotes thrombosis but also activates the inflammatory response, further inducing venous thrombosis. However, conventional treatments such as standard anticoagulant/endovascular therapy (EVT) do not seem to improve prognosis. Anti-inflammatory therapy may be a new way to treat the disease. Methods We enrolled five patients with acute/subacute severe CVT with hereditary PCD/PSD from January 2020 to July 2022. In addition to standard anticoagulant therapy, all of them were given short-term methylprednisolone pulse therapy. Neurological deficit, increased intracranial pressure, venous recanalization, serum and cerebrospinal fluid (CSF) inflammatory markers and adverse events were retrospectively described before and after treatment and at 6 months after discharge. Results Inflammatory indexes of all patients were significantly elevated on admission. After methylprednisolone pulse therapy, serum inflammatory indexes including neutrophil-to-lymphocyte ratio (P=0.043); platelet-to-lymphocyte ratio (P=0.043); systemic immune inflammatory index (P=0.043); interleukin-6 (P=0.043) and hypersensitive C-reactive protein (P=0.022) reduced dramatically compared with baseline. CSF inflammatory indexes had a decreasing trend compared with baseline (P>0.05). In terms of venous recanalization, one patient achieved complete recanalization, four patients obtained partial recanalization. Compared with baseline on admission, the NIH Stroke Scale (NIHSS), modified Rankin Scale (mRS) and intracranial pressure were all considerably lower at discharge (P=0.029, P=0.041 and P=0.017). At 6-month follow-up, NIHSS and mRS further declined. During hospitalization and 6-month follow-up, none of the five patients experienced severe steroid-related adverse effects such as recurrence of venous thrombosis, spontaneous fracture or osteonecrosis, and gastroduodenal ulcer. Conclusion Acute/subacute severe CVT with hereditary PCD/PSD has high levels of inflammation. In addition to conventional anticoagulant therapy, early anti-inflammatory therapy using steroids may be necessary. Nevertheless, substantial randomized controlled trials with larger sample sizes are required for further investigation.
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Affiliation(s)
- Wensi Hao
- Department of Emergency, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Yaqin Gu
- Department of Emergency, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Shuyuan Hu
- Department of Emergency, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Xunming Ji
- Department of Emergency, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Yuping Wang
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
| | - Jiangang Duan
- Department of Emergency, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, People’s Republic of China
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Abstract
PURPOSE OF REVIEW To provide an overview of the state-of-the-art in protein C (PC) pathway research. RECENT FINDINGS The PC pathway is crucial for maintaining hemostasis to prevent venous thromboembolism. This is evident from genetic mutations that result in impaired PC pathway activity and contribute to increased venous thromboembolism risk in affected individuals. In addition to its anticoagulant role, activated PC (APC) also mediates a complex, pleiotropic role in the maintenance of vascular cell health, which it achieves via anti-inflammatory and antiapoptotic cell signaling on endothelial cells. Emerging data have demonstrated that cell signaling by APC, mediated by multiple receptor interactions on different cell types, also confers cytoprotective and anti-inflammatory benefits. Defects in both arms of the PC pathway are associated with increased susceptibility to thrombo-inflammatory disease in various preclinical thrombotic, proinflammatory and neurological disease models. Moreover, recent studies have identified attenuation of anticoagulant PC pathway activity as an exciting therapeutic opportunity to promote hemostasis in patients with inherited or acquired bleeding disorders. SUMMARY In this review, we provide an overview of some recent developments in our understanding of the PC pathways.
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Affiliation(s)
- Gemma Leon
- Irish Centre for Vascular Biology, School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland
- National Children's Research Centre, Our Lady's Children's Hospital Crumlin, Crumlin, Dublin 12, Ireland
| | - Aisling M Rehill
- Irish Centre for Vascular Biology, School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland
| | - Roger J S Preston
- Irish Centre for Vascular Biology, School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland
- National Children's Research Centre, Our Lady's Children's Hospital Crumlin, Crumlin, Dublin 12, Ireland
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Eliwan HO, Watson WRG, Regan I, Philbin B, O'Hare FM, Strickland T, O'Neill A, O'Rourke M, Blanco A, Healy M, Nolan B, Smith O, Molloy EJ. Pediatric Intensive Care: Immunomodulation With Activated Protein C ex vivo. Front Pediatr 2019; 7:386. [PMID: 31612119 PMCID: PMC6776988 DOI: 10.3389/fped.2019.00386] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Accepted: 09/06/2019] [Indexed: 11/21/2022] Open
Abstract
Objective: Sepsis is major cause of morbidity and mortality in the Pediatric Intensive Care Unit (PICU). PICU patients may develop transient immune deficiency during sepsis. Activated Protein C (APC) has significant anti-inflammatory and cytoprotective effects. Clinical trials of APC in adult sepsis initially showed improved outcome but recent trials showed no benefit in adults or children. We aimed to assess the effects of APC treatment on innate immune responses in children. Design and Subjects: We compared neutrophil and monocyte responses to lipopolysaccharide (LPS) with and without APC treatment in PICU patients at the time of evaluation for sepsis compared with healthy adults and age-matched pediatric controls. We used flow cytometry to examine cell activation (CD11b expression), function [intracellular reactive oxygen intermediate (ROI) release] and LPS recognition [Toll like Receptor 4 (TLR4) expression]. Results: PICU patients had significantly decreased protein c levels and LPS responses compared with adult and pediatric controls for all parameters. APC reduced LPS-induced neutrophil PICU TLR4 and adult ROI (p < 0.05). PICU non-survivors had increased LPS induced neutrophil and monocyte ROI production vs. survivors which was significantly reduced by APC. Conclusion: PICU patients demonstrate significantly reduced endotoxin reactivity which may predispose them to sepsis and alter effective antibacterial responses. APC reduces LPS-induced ROI production in adults and may have a role in treating severely compromised PICU patients especially given that newer APC forms are associated with decreased bleeding risk and enhanced anti-inflammatory effects.
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Affiliation(s)
- Hassan O Eliwan
- Neonatology, National Maternity Hospital, Dublin, Ireland.,National Children's Research Centre, Dublin, Ireland.,Paediatrics, Royal College of Surgeons in Ireland, Dublin, Ireland.,University College Dublin School of Medicine and Medical Sciences, Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - William R G Watson
- University College Dublin School of Medicine and Medical Sciences, Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Irene Regan
- Haematology, Our Lady's Children's Hospital, Dublin, Ireland
| | - Brian Philbin
- Haematology, Our Lady's Children's Hospital, Dublin, Ireland
| | - Fiona M O'Hare
- Neonatology, National Maternity Hospital, Dublin, Ireland.,National Children's Research Centre, Dublin, Ireland.,University College Dublin School of Medicine and Medical Sciences, Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Tammy Strickland
- Paediatrics, Trinity College, The University of Dublin, Dublin, Ireland
| | - Amanda O'Neill
- University College Dublin School of Medicine and Medical Sciences, Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | | | - Alfonso Blanco
- University College Dublin School of Medicine and Medical Sciences, Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Martina Healy
- Critical Care, Our Lady's Children's Hospital, Dublin, Ireland
| | - Beatrice Nolan
- Haematology, Our Lady's Children's Hospital, Dublin, Ireland
| | - Owen Smith
- Haematology, Our Lady's Children's Hospital, Dublin, Ireland
| | - Eleanor J Molloy
- Neonatology, National Maternity Hospital, Dublin, Ireland.,National Children's Research Centre, Dublin, Ireland.,Paediatrics, Royal College of Surgeons in Ireland, Dublin, Ireland.,University College Dublin School of Medicine and Medical Sciences, Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland.,Paediatrics, Trinity College, The University of Dublin, Dublin, Ireland.,Neonatology, Our Lady's Children's Hospital, Dublin, Ireland.,Paediatrics, Coombe Women's and Infant's University Hospital, Dublin, Ireland
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Pathological Roles of Neutrophil-Mediated Inflammation in Asthma and Its Potential for Therapy as a Target. J Immunol Res 2017; 2017:3743048. [PMID: 29359169 PMCID: PMC5735647 DOI: 10.1155/2017/3743048] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 09/10/2017] [Accepted: 09/27/2017] [Indexed: 12/22/2022] Open
Abstract
Asthma is a chronic inflammatory disease that undermines the airways. It is caused by dysfunction of various types of cells, as well as cellular components, and is characterized by recruitment of inflammatory cells, bronchial hyperreactivity, mucus production, and airway remodelling and narrowing. It has commonly been considered that airway inflammation is caused by the Th2 immune response, or eosinophilia, which is a hallmark of bronchial asthma pathogenesis. Some patients display a neutrophil-dominant presentation and are characterized with low (or even absent) Th2 cytokines. In recent years, increasing evidence has also suggested that neutrophils play a key role in the development of certain subtypes of asthma. This review discusses neutrophils in asthma and potentially related targeted therapies.
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Wong VM, Côté O, Bienzle D, Hayes MA, Wood RD. Endothelial protein C receptor-dependent antichemotactic effects of canine protein C. Am J Vet Res 2017; 78:186-194. [PMID: 28140640 DOI: 10.2460/ajvr.78.2.186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether canine protein C (CnPC) had antichemotactic effects on canine neutrophils, whether endothelial protein C receptor (EPCR) was expressed on canine neutrophils, and the role of EPCR in neutrophil chemotaxis. SAMPLE Neutrophils isolated from blood samples from healthy dogs (n = 6) and sick dogs with (2) or without (3) an inflammatory leukogram. PROCEDURES Neutrophils were analyzed by reverse transcriptase PCR assay and flow cytometry for detection of EPCR mRNA and protein expression, respectively. Neutrophils were incubated with CnPC zymogen or canine activated protein C (CnAPC), with or without RCR-379 (an anti-human EPCR antibody). Neutrophils were then allowed to migrate through a filter membrane toward a chemokine. Untreated neutrophils served as positive control samples. Migration was quantified by fluorescence measurement, and chemotaxis index (Chx) values (fluorescence of test sample/fluorescence of positive control sample) were computed. RESULTS The cDNA for EPCR was amplified, and EPCR expression was detected on neutrophil surfaces. Obtained Chx values were significantly higher in cells treated with RCR-379 than in cells treated with CnPC or CnAPC alone. The Chx values for neutrophils treated with RCR-379 were not significantly different from 1, whereas those for neutrophils treated without RCR-379 were significantly less than 1. The effects of RCR-379 on neutrophil migration were independent of concentration or activation status of protein C. CONCLUSIONS AND CLINICAL RELEVANCE Canine neutrophils expressed EPCR, and inhibition of neutrophil chemotaxis by CnPC and CnAPC depended on EPCR. Interventions with EPCR signaling may have therapeutic application in dogs.
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de Boer JD, Berger M, Majoor CJ, Kager LM, Meijers JCM, Terpstra S, Nieuwland R, Boing AN, Lutter R, Wouters D, van Mierlo GJ, Zeerleder SS, Bel EH, van't Veer C, de Vos AF, van der Zee JS, van der Poll T. Activated protein C inhibits neutrophil migration in allergic asthma: a randomised trial. Eur Respir J 2015; 46:1636-44. [PMID: 26381519 DOI: 10.1183/13993003.00459-2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Accepted: 06/28/2015] [Indexed: 11/05/2022]
Abstract
Asthma patients show evidence of a procoagulant state in their airways, accompanied by an impaired function of the anticoagulant protein C system. We aimed to study the effect of recombinant human activated protein C (rhAPC) in allergic asthma patients.We conducted a randomised, double-blind, placebo-controlled, proof-of-concept study in house dust mite (HDM) allergic asthma patients. Patients were randomised to receive intravenous rhAPC (24 µg·kg(-1)·h(-1); n=12) or placebo (n=12) for 11 h. 4 h after the start of infusion, a first bronchoscopy was performed to challenge one lung segment with saline (control) and a contralateral segment with a combination of HDM extract and lipopolysaccharide (HDM+LPS), thereby mimicking environmental house dust exposure. A second bronchoscopy was conducted 8 h after intrabronchial challenge to obtain bronchoalveolar lavage fluid (BALF).rhAPC did not influence HDM+LPS induced procoagulant changes in the lung. In contrast, rhAPC reduced BALF leukocyte counts by 43% relative to placebo, caused by an inhibitory effect on neutrophil influx (64% reduction), while leaving eosinophil influx unaltered. rhAPC also reduced neutrophil degranulation products in the airways.Intravenous rhAPC attenuates HDM+LPS-induced neutrophil migration and protein release in allergic asthma patients by an effect that does not rely on coagulation inhibition.
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Affiliation(s)
- J Daan de Boer
- Center of Infection and Immunity Amsterdam, and Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Marieke Berger
- Dept of Respiratory Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands These authors contributed equally to this work
| | - Christof J Majoor
- Dept of Respiratory Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands These authors contributed equally to this work
| | - Liesbeth M Kager
- Center of Infection and Immunity Amsterdam, and Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Joost C M Meijers
- Dept of Experimental Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands Dept of Plasma Proteins, Sanquin, Amsterdam, the Netherlands
| | - Sanne Terpstra
- Center of Infection and Immunity Amsterdam, and Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Rienk Nieuwland
- Dept of Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Anita N Boing
- Dept of Clinical Chemistry, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - René Lutter
- Dept of Respiratory Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands Dept of Experimental Immunology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Diana Wouters
- Dept of Immunopathology, Sanquin, Amsterdam, the Netherlands
| | | | - Sacha S Zeerleder
- Dept of Immunopathology, Sanquin, Amsterdam, the Netherlands Dept of Hematology, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Elisabeth H Bel
- Dept of Respiratory Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Cornelis van't Veer
- Center of Infection and Immunity Amsterdam, and Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Alex F de Vos
- Center of Infection and Immunity Amsterdam, and Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | | | - Tom van der Poll
- Center of Infection and Immunity Amsterdam, and Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
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Eliwan HO, Watson RWG, Aslam S, Regan I, Philbin B, O'Hare FM, O'Neill A, Preston R, Blanco A, Grant T, Nolan B, Smith O, Molloy EJ. Neonatal brain injury and systemic inflammation: modulation by activated protein C ex vivo. Clin Exp Immunol 2015; 179:477-84. [PMID: 25204207 DOI: 10.1111/cei.12453] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2014] [Indexed: 01/04/2023] Open
Abstract
Infection and inflammation can be antecedents of neonatal encephalopathy (NE) and increase the risk of neurological sequelae. Activated protein C (APC) has anti-coagulant and anti-inflammatory effects and provides neuroprotection in brain and spinal cord injury. We examined neutrophil and monocyte responses to lipopolysaccharide (LPS) in infants with NE compared with healthy adult and neonatal controls, and also studied the effect of APC. Whole blood was incubated with LPS and APC and Toll-like receptor (TLR)-4 (LPS recognition), CD11b expression (activation) and intracellular reactive oxygen intermediate (ROI; function) release from neutrophils and monocytes was examined by flow cytometry serially from days 1 to 7. We found a significant increase in neutrophil ROI in infants with NE on day 3 following LPS compared to neonatal controls and this augmented response was reduced significantly by APC. Neutrophil and monocyte CD11b expression was increased significantly on day 1 in infants with NE compared to neonatal controls. LPS-induced neutrophil TLR-4 expression was increased significantly in infants with NE on days 3 and 7 and was reduced by APC. LPS-induced monocyte TLR-4 was increased significantly in infants with NE on day 7. Neutrophil and monocyte activation and production of ROIs may mediate tissue damage in infants with NE. APC modified LPS responses in infants with NE. APC may reduce the inflammatory responses in NE and may ameliorate multi-organ dysfunction. Further study of the immunomodulatory effects of protein C may be warranted using mutant forms with decreased bleeding potential.
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Affiliation(s)
- H O Eliwan
- Paediatrics, National Maternity Hospital, Dublin, Ireland; UCD School of Medicine and Medical Science and Conway Institute for Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland; National Children Research Centre, Dublin, Ireland; Paediatrics, Royal College of Surgeons in Ireland, Dublin, Ireland
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9
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de Boer JD, Kager LM, Roelofs JJTH, Meijers JCM, de Boer OJ, Weiler H, Isermann B, van 't Veer C, van der Poll T. Overexpression of activated protein C hampers bacterial dissemination during pneumococcal pneumonia. BMC Infect Dis 2014; 14:559. [PMID: 25366058 PMCID: PMC4228088 DOI: 10.1186/s12879-014-0559-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 10/14/2014] [Indexed: 12/27/2022] Open
Abstract
Background During pneumonia, inflammation and coagulation are activated as part of anti-bacterial host defense. Activated protein C (APC) has anticoagulant and anti-inflammatory properties and until recently was a registered drug for the treatment of severe sepsis. Streptococcus (S.) pneumoniae is the most common causative pathogen in community-acquired pneumonia. Methods We aimed to investigate the effect of high APC levels during experimental pneumococcal pneumonia. Wild type (WT) and APC overexpressing (APChigh)-mice were intranasally infected with S. pneumoniae and sacrificed after 6, 24 or 48 hours, or followed in a survival study. Results In comparison to WT mice, APChigh-mice showed decreased bacterial dissemination to liver and spleen, while no differences in bacterial loads were detected at the primary site of infection. Although no differences in the extent of lung histopathology were seen, APChigh-mice showed a significantly decreased recruitment of neutrophils into lung tissue and bronchoalveolar lavage fluid. Activation of coagulation was not altered in APChigh-mice. No differences in survival were observed between WT and APChigh-mice (P =0.06). Conclusion APC overexpression improves host defense during experimental pneumococcal pneumonia. This knowledge may add to a better understanding of the regulation of the inflammatory and procoagulant responses during severe Gram-positive pneumonia. Electronic supplementary material The online version of this article (doi:10.1186/s12879-014-0559-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Johannes Daan de Boer
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands. .,Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, The Netherlands.
| | - Liesbeth M Kager
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands. .,Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, The Netherlands. .,Center for Experimental and Molecular Medicine (CEMM), Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, University of Amsterdam, Meibergdreef 9, Room G2-130, 1105 AZ, Amsterdam, The Netherlands.
| | - Joris J T H Roelofs
- Department of Pathology, Academic Medical Center, Amsterdam, The Netherlands.
| | - Joost C M Meijers
- Department of Experimental Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands. .,Department Plasma Proteins, Sanquin, Amsterdam, The Netherlands.
| | - Onno J de Boer
- Department of Pathology, Academic Medical Center, Amsterdam, The Netherlands.
| | - Hartmut Weiler
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI, USA.
| | - Berend Isermann
- Department of Clinical Chemistry and Pathobiochemistry, Otto-von-Guericke University, Magdeburg, Germany.
| | - Cornelis van 't Veer
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands. .,Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, The Netherlands.
| | - Tom van der Poll
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, The Netherlands. .,Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, The Netherlands. .,Division of Internal Medicine, Academic Medical Center, Amsterdam, The Netherlands.
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Xue M, Jackson CJ. Activated protein C and its potential applications in prevention of islet β-cell damage and diabetes. VITAMINS AND HORMONES 2014; 95:323-63. [PMID: 24559924 DOI: 10.1016/b978-0-12-800174-5.00013-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Activated protein C (APC) is derived from its precursor, protein C (PC). Originally thought to be synthesized exclusively by the liver, recent reports have shown that PC is also produced by many other cells including pancreatic islet β cells. APC functions as a physiological anticoagulant with anti-inflammatory, anti-apoptotic, and barrier-stabilizing properties. APC exerts its protective effects via an intriguing mechanism requiring combinations of endothelial PC receptor, protease-activated receptors, epidermal growth factor receptor, Tie2 or CD11b, depending on cell types. Diabetes is a chronic condition resulted from the body's inability to produce and/or properly use insulin. The prevalence of diabetes has risen dramatically and has become one of the major causes of premature mortality and morbidity worldwide. Diabetes prevention is an ideal approach to reduce this burden. Type 1 and type 2 diabetes are the major forms of diabetes mellitus, and both are characterized by an autoimmune response, intraislet inflammation, β-cell apoptosis, and progressive β-cell loss. Protecting β-cell from damage is critical in both prevention and treatment of diabetes. Recent in vitro and animal studies show that APC's strong anti-inflammatory and anti-apoptotic properties are beneficial in preventing β-cell destruction and diabetes in the NOD mouse model of type 1 diabetes. Future preventive and therapeutic uses of APC in diabetes look very promising.
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Affiliation(s)
- Meilang Xue
- Sutton Arthritis Research Laboratories, Kolling Institute of Medical Research, The University of Sydney at Royal North Shore Hospital, St Leonards, New South Wales, Australia.
| | - Christopher J Jackson
- Sutton Arthritis Research Laboratories, Kolling Institute of Medical Research, The University of Sydney at Royal North Shore Hospital, St Leonards, New South Wales, Australia
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Wildhagen KCAA, Schrijver R, Beckers L, ten Cate H, Reutelingsperger CPM, Lutgens E, Nicolaes GAF. Effects of exogenous recombinant APC in mouse models of ischemia reperfusion injury and of atherosclerosis. PLoS One 2014; 9:e101446. [PMID: 25032959 PMCID: PMC4102480 DOI: 10.1371/journal.pone.0101446] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 06/06/2014] [Indexed: 01/12/2023] Open
Abstract
Activated protein C (APC) is a serine protease that has both anticoagulant and cytoprotective properties. The cytoprotective effects are protease activated receptor 1 (PAR-1) and endothelial protein C receptor (EPCR) dependent and likely underlie protective effects of APC in animal models of sepsis, myocardial infarction and ischemic stroke. S360A-(A)PC, a variant (A)PC that has no catalytic activity, binds EPCR and shifts pro-inflammatory signaling of the thrombin-PAR-1 complex to anti-inflammatory signaling. In this study we investigated effects of human (h)wt-PC, hS360A-PC, hwt-APC and hS360A-APC in acute (mouse model of acute myocardial ischemia/reperfusion (I/R) injury) and chronic inflammation (apoE-/- mouse model of atherosclerosis). All h(A)PC variants significantly reduced myocardial infarct area (p<0.05) following I/R injury. IL-6 levels in heart homogenates did not differ significantly between sham, placebo and treatment groups in I/R injury. None of the h(A)PC variants decreased number and size of atherosclerotic plaques in apoE-/- mice. Only hS360A-APC slightly affected phenotype of plaques. IL-6 levels in plasma were significantly (p<0.001) decreased in hwt-APC and hS360A-PC treated mice. In the last group levels of monocyte chemotactic protein 1 (MCP-1) were significantly increased (p<0.05). In this study we show that both hwt and hS360A-(A)PC protect against acute myocardial I/R injury, which implies that protection from I/R injury is independent of the proteolytic activity of APC. However, in the chronic atherosclerosis model hwt and hS360-(A)PC had only minor effects. When the dose, species and mode of (A)PC administration will be adjusted, we believe that (A)PC will have potential to influence development of chronic inflammation as occurring during atherosclerosis as well.
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Affiliation(s)
- Karin C. A. A. Wildhagen
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Roy Schrijver
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Linda Beckers
- Department of Medical Biochemistry, Academic Medical Center, Amsterdam, The Netherlands
| | - Hugo ten Cate
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
- Department of Internal Medicine, Laboratory for Clinical Thrombosis and Haemostasis, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Chris P. M. Reutelingsperger
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Esther Lutgens
- Department of Medical Biochemistry, Academic Medical Center, Amsterdam, The Netherlands
| | - Gerry A. F. Nicolaes
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
- * E-mail:
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Schulte W, Bernhagen J, Bucala R. Cytokines in sepsis: potent immunoregulators and potential therapeutic targets--an updated view. Mediators Inflamm 2013; 2013:165974. [PMID: 23853427 PMCID: PMC3703895 DOI: 10.1155/2013/165974] [Citation(s) in RCA: 466] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Accepted: 05/22/2013] [Indexed: 12/11/2022] Open
Abstract
Sepsis and septic shock are among the leading causes of death in intensive care units worldwide. Numerous studies on their pathophysiology have revealed an imbalance in the inflammatory network leading to tissue damage, organ failure, and ultimately, death. Cytokines are important pleiotropic regulators of the immune response, which have a crucial role in the complex pathophysiology underlying sepsis. They have both pro- and anti-inflammatory functions and are capable of coordinating effective defense mechanisms against invading pathogens. On the other hand, cytokines may dysregulate the immune response and promote tissue-damaging inflammation. In this review, we address the current knowledge of the actions of pro- and anti-inflammatory cytokines in sepsis pathophysiology as well as how these cytokines and other important immunomodulating agents may be therapeutically targeted to improve the clinical outcome of sepsis.
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Affiliation(s)
- Wibke Schulte
- Department of Internal Medicine, Yale University School of Medicine, The Anlyan Center, S525, P.O. Box 208031, 300 Cedar Street, New Haven, CT 06520-8031, USA
- Institute of Biochemistry and Molecular Cell Biology, University Hospital of RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Jürgen Bernhagen
- Institute of Biochemistry and Molecular Cell Biology, University Hospital of RWTH Aachen University, Pauwelsstraße 30, 52074 Aachen, Germany
| | - Richard Bucala
- Department of Internal Medicine, Yale University School of Medicine, The Anlyan Center, S525, P.O. Box 208031, 300 Cedar Street, New Haven, CT 06520-8031, USA
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Lili X, Zhiyong H, Jianjun S. A preliminary study of the effects of ulinastatin on early postoperative cognition function in patients undergoing abdominal surgery. Neurosci Lett 2013; 541:15-9. [DOI: 10.1016/j.neulet.2013.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 02/04/2013] [Accepted: 02/05/2013] [Indexed: 10/27/2022]
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Yu C, Xu L, Chen LF, Guan YJ, Kim M, Biffl WL, Chin YE. PRBC-derived plasma induces non-muscle myosin type IIA-mediated neutrophil migration and morphologic change. Immunopharmacol Immunotoxicol 2012; 35:71-9. [PMID: 23083320 PMCID: PMC3541669 DOI: 10.3109/08923973.2012.677046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Context: Neutrophils are the primary effector cells in the pathogenesis of transfusion-related acute lung injury or multiple organ failure after blood transfusion. Objective: We aimed to investigate the effect of fresh (1 day preparation) and aged (42 day preparation) PRBC-derived plasma on neutrophil morphology, migration and phagocytosis. Materials and methods: We evaluated the production of reactive oxygen species (ROS) and the expression of non-muscle myosin heavy chain IIA (MYH9) in neutrophils treated with PRBC-derived plasma. We used western blots and antibody arrays to evaluate changes in signal transduction pathways in plasma-treated neutrophils. Results: Aged PRBC-derived plasma elicited a stronger oxidative burst in neutrophils when compared with fresh PRBC-derived plasma (p < 0.05). Antibody arrays showed increased phosphorylation of NF-ĸB proteins (p105, p50 and Ikk) in aged PRBC-derived plasma-treated neutrophils. The expression of non-muscle myosin IIA (MYH9), a cytoskeleton protein involved in immune cell migration and morphological change, was also significantly upregulated in neutrophils treated with aged PRBC-derived plasma compared to fresh plasma (p < 0.05). Pretreatment of neutrophils with blebbistatin (a specific type II myosin inhibitor), ascorbic acid (an antioxidant), or staurosporine (a protein tyrosine kinase inhibitor), effectively abrogated the morphological changes, neutrophil migration, and phagocytosis induced by aged PRBC-derived plasma. Conclusion: Upregulation of MYH9 in neutrophils treated with aged PRBC-derived plasma and abrogation of neutrophil migration in blebbistatin-treated neutrophils suggested a functional role of MYH9 in the directional migration of immune cells. Our data help elucidate the cellular and molecular mechanisms of transfusion-related injury.
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Affiliation(s)
- Chen Yu
- Department of Nephrology, Tongji Hospital, Tongji Universith School of Medicine, Shanghai, China
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Activated Protein C Does Not Alleviate the Course of Systemic Inflammation in the APCAP Trial. Int J Inflam 2012; 2012:712739. [PMID: 22645700 PMCID: PMC3356881 DOI: 10.1155/2012/712739] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Accepted: 02/20/2012] [Indexed: 12/22/2022] Open
Abstract
The study aimed to determine the effect of the activated protein C on the course of systemic inflammation in the APCAP (activated protein C in acute pancreatitis) trial where we randomized 32 patients with severe acute pancreatitis to receive either recombinant activated protein C (drotrecogin alfa activated) (n = 16) or placebo (n = 16) for 96 hours. In the present study, we present the time course of the patients' plasma or serum levels of soluble markers (IL-8, IL-6, IL-10, IL-1ra, sE-selectin, PCT) and monocyte and neutrophil cell surface (CD11b, CD14, CD62L, HLA-DR) markers of systemic inflammatory response during the first 14 days after the randomization. The results of the intervention and placebo groups were comparable showing that recombinant APC treatment did not alter the course of systemic inflammation in severe acute pancreatitis. Our finding is in accordance with the clinical findings in the APCAP trial indicating that the intervention did not affect evolution of multiple organ dysfunctions.
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Zhou J, Pavlovic D, Willecke J, Friedel C, Whynot S, Hung O, Cerny V, Schroeder H, Wendt M, Shukla R, Lehmann C. Activated protein C improves pial microcirculation in experimental endotoxemia in rats. Microvasc Res 2012; 83:276-80. [PMID: 22426124 DOI: 10.1016/j.mvr.2012.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 02/17/2012] [Accepted: 03/01/2012] [Indexed: 10/28/2022]
Abstract
INTRODUCTION The brain is one of the first organs affected clinically in sepsis. Microcirculatory alterations are suggested to be a critical component in the pathophysiology of sepsis. The aim of this study was to investigate the effects of recombinant human activated protein C (rhAPC) on the pial microcirculation in experimental endotoxemia using intravital microscopy. Our hypothesis is rhAPC protects pial microcirculation in endotoxemia. METHODS Endotoxemia was generated in Lewis rats with intravenous injection of lipopolysaccharide (LPS, 5 mg/kg i.v.). Dura mater was removed through a cranial window to expose pial vessels on the brain surface. The microcirculation, including leukocyte-endothelial interaction, functional capillary density (FCD) and plasma extravasation of pial vessels was examined by fluorescent intravital microscopy (IVM) 2 h after administration of LPS, LPS and rhAPC or equivalent amount of saline (used as Control group). Plasma cytokine levels of interleukin 1 alpha (IL1-α), tumor necrosis factor-α (TNF-α), interferon γ (IFN-γ), Monocyte chemotactic protein-1 (MCP-1) and Granulocyte-macrophage colony-stimulating factor (GM-CSF) were evaluated after IVM. RESULTS LPS challenge significantly increased leukocyte adhesion (773±190 vs. 592±152 n/mm(2) Control), decreased FCD (218±54 vs. 418±74 cm/cm(2) Control) and increased proinflammatory cytokine levels (IL-1α: 5032±1502 vs. 8±21 pg/ml; TNF-α: 1823±1007 vs. 168±228 pg/ml; IFN-γ: 785±434 vs. 0 pg/ml; GM-CSF: 54±52 vs. 1±3 pg/ml) compared to control animals. rhAPC treatment significantly reduced leukocyte adhesion (599±111 n/mm(2)), increased FCD (516±118 cm/cm(2)) and reduced IL-1α levels (2134±937 pg/ml) in the endotoxemic rats. CONCLUSION APC treatment significantly improves pial microcirculation by reducing leukocyte adhesion and increasing FCD.
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Affiliation(s)
- Juan Zhou
- Department of Anesthesia, Dalhousie University, Halifax, NS, Canada
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Sepsis Immunopathology: Perspectives of Monitoring and Modulation of the Immune Disturbances. Arch Immunol Ther Exp (Warsz) 2012; 60:123-35. [DOI: 10.1007/s00005-012-0166-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 11/07/2011] [Indexed: 02/02/2023]
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Maniatis NA, Letsiou E, Orfanos SE, Kardara M, Dimopoulou I, Nakos G, Lekka ME, Roussos C, Armaganidis A, Kotanidou A. Inhaled activated protein C protects mice from ventilator-induced lung injury. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:R70. [PMID: 20403177 PMCID: PMC2887192 DOI: 10.1186/cc8976] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 02/14/2010] [Accepted: 04/19/2010] [Indexed: 01/11/2023]
Abstract
INTRODUCTION Activated Protein C (APC), an endogenous anticoagulant, improves tissue microperfusion and endothelial cell survival in systemic inflammatory states such as sepsis, but intravenous administration may cause severe bleeding. We have thus addressed the role of APC delivered locally by inhalation in preventing acute lung injury from alveolar overdistention and the subsequent ventilator-induced lung injury (VILI). We also assessed the effects of APC on the activation status of Extracellular- Regulated Kinase 1/2 (ERK) pathway, which has been shown to be involved in regulating pulmonary responses to mechanical stretch. METHODS Inhaled APC (12.5 microg drotrecogin-alpha x 4 doses) or saline was given to tracheotomized C57/Bl6 mice starting 20 min prior to initiation of injurious mechanical ventilation with tidal volume 25 mL/Kg for 4 hours and then hourly thereafter; control groups receiving inhaled saline were ventilated with 8 mL/Kg for 30 min or 4 hr. We measured lung function (respiratory system elastance H), arterial blood gases, surrogates of vascular leak (broncho-alveolar lavage (BAL) total protein and angiotensin-converting enzyme (ACE)-activity), and parameters of inflammation (BAL neutrophils and lung tissue myeloperoxidase (MPO) activity). Morphological alterations induced by mechanical ventilation were examined in hematoxylin-eosin lung tissue sections. The activation status of ERK was probed in lung tissue homogenates by immunoblotting and in paraffin sections by immunohistochemistry. The effect of APC on ERK signaling downstream of the thrombin receptor was tested on A549 human lung epithelial cells by immunoblotting. Statistical analyses were performed using ANOVA with appropriate post-hoc testing. RESULTS In mice subjected to VILI without APC, we observed hypoxemia, increased respiratory system elastance and inflammation, assessed by BAL neutrophil counts and tissue MPO activity. BAL total protein levels and ACE activity were also elevated by VILI, indicating compromise of the alveolo-capillary barrier. In addition to preserving lung function, inhaled APC prevented endothelial barrier disruption and attenuated hypoxemia and the inflammatory response. Mechanistically, we found a strong activation of ERK in lung tissues by VILI, which was prevented by APC, suggestive of pathogenetic involvement of the Mitogen-Activated Kinase pathway. In cultured human lung epithelial cells challenged by thrombin, APC abrogated the activation of ERK and its downstream effector, cytosolic Phospholipase A2. CONCLUSIONS Topical application of APC by inhalation may effectively reduce lung injury induced by mechanical ventilation in mice.
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Affiliation(s)
- Nikolaos A Maniatis
- 2nd Dept, of Critical Care, Attikon Hospital, National and Kapodistrian University of Athens Medical School, Rimini 1, Haidari, Greece.
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Abstract
Immunotherapy in the critically ill is an appealing notion because of the apparent abnormal immune and inflammatory responses seen in so many patients. The administration of a medication that could alter immune responses and decrease mortality in patients with sepsis could represent a ‘magic bullet’. Various approaches have been tried over the last 20 yr: steroids; anti-endotoxin or anti-cytokine antibodies; cytokine receptor antagonists; and other agents with immune-modulating side-effects. However, in some respects, research along these lines has been unsuccessful or disappointing at best. The current state of knowledge is summarized with particular reference to sepsis and the acute respiratory distress syndrome.
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Affiliation(s)
- N R Webster
- Anaesthesia and Intensive Care, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK
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Gong Y, Chen N, Wang FQ, Wang ZH, Xu HX. Serum proteome alteration of severe sepsis in the treatment of continuous renal replacement therapy. Nephrol Dial Transplant 2009; 24:3108-14. [DOI: 10.1093/ndt/gfp231] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Neyrinck AP, Liu KD, Howard JP, Matthay MA. Protective mechanisms of activated protein C in severe inflammatory disorders. Br J Pharmacol 2009; 158:1034-47. [PMID: 19466992 DOI: 10.1111/j.1476-5381.2009.00251.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The protein C system is an important natural anticoagulant mechanism mediated by activated protein C (APC) that regulates the activity of factors VIIIa and Va. Besides well-defined anticoagulant properties, APC also demonstrates anti-inflammatory, anti-apoptotic and endothelial barrier-stabilizing effects that are collectively referred to as the cytoprotective effects of APC. Many of these beneficial effects are mediated through its co-receptor endothelial protein C receptor, and the protease-activated receptor 1, although exact mechanisms remain unclear and are likely pleiotropic in nature. Increased insight into the structure-function relationships of APC facilitated design of APC variants that conserve cytoprotective effects and reduce anticoagulant features, thereby attenuating the risk of severe bleeding with APC therapy. Impairment of the protein C system plays an important role in acute lung injury/acute respiratory distress syndrome and severe sepsis. The pathophysiology of both diseases states involves uncontrolled inflammation, enhanced coagulation and compromised fibrinolysis. This leads to microvascular thrombosis and organ injury. Administration of recombinant human APC to correct the dysregulated protein C system reduced mortality in severe sepsis patients (PROWESS trial), which stimulated further research into its mechanisms of action. Several other clinical trials evaluating recombinant human APC have been completed, including studies in children and less severely ill adults with sepsis as well as a study in acute lung injury. On the whole, these studies have not supported the use of APC in these populations and challenge the field of APC research to search for additional answers.
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Affiliation(s)
- Arne P Neyrinck
- University of California San Francisco, Cardiovascular Research Institute, San Francisco, CA, USA
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